Sample records for cephalothin dicloxacillin imipenem

  1. In vitro activity effects of combinations of cephalothin, dicloxacillin, imipenem, vancomycin and amikacin against methicillin-resistant Staphylococcus spp. strains (United States)

    Miranda-Novales, Guadalupe; Leaños-Miranda, Blanca E; Vilchis-Pérez, Mariano; Solórzano-Santos, Fortino


    Background combinations of drugs has been proposed as an alternative for oxacillin-resistant staphylococci infections, however, limited information about in vitro combinations are available for multi-resistant strains. The objective of this study was to describe the interaction of beta-lactams in combination with vancomycin or amikacin against 26 oxacillin and amikacin-resistant nosocomial Staphylococcus spp. isolates. Methods activity of dicloxacillin plus amikacin, cephalothin plus amikacin, cephalothin plus vancomycin, imipenem plus vancomycin and vancomycin plus amikacin was evaluated by checkerboard synergy tests and the fractional inhibitory concentration index (FIC) was calculated. Results: dicloxacillin plus amikacin, and cephalothin plus amikacin were synergistic or partially synergistic in 84.6% and 100% respectively. For nearly half of the isolates the mean concentrations of dicloxacillin, cephalothin and amikacin at which FIC indexes were calculated were achievable therapeutically. Vancomycin plus amikacin had synergistic effect only against two isolates, and partially synergistic in 38.6%. For the combinations vancomycin plus cephalothin and vancomycin plus imipenem the effect was additive in 76.9% and 80.7% respectively. Conclusion in this study the checkerboard analysis showed that amikacin in combination with cephalothin or dicloxacillin was synergistic against most of the resistant strains of S. aureus and coagulase-negative Staphylococcus. Vancomycin in combination with a beta-lactam (cephalothin or imipenem) showed additivity. An indifferent effect predominated for the combination vancomycin plus amikacin. Even though a synergistic effect is expected when using a beta-lactam plus amikacin combination, it is possible that the effect cannot be clinically achievable. Careful selection of antimicrobial combinations and initial MICs are mandatory for future evaluations. PMID:17034644

  2. Compound list: cephalothin [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available cephalothin CLT 00141 ...

  3. A case of cephalothin-associated urolithiasis

    Directory of Open Access Journals (Sweden)

    Ivan WM Lim


    Full Text Available Ivan WM Lim1, Peter JO Stride1,2, Robert L Horvath31Department of Medicine, Redcliffe Hospital, Redcliffe, Queensland, Australia; 2University of Queensland School of Medicine, Redcliffe, Queensland, Australia; 3Infectious Diseases Department, Prince Charles Hospital, Brisbane, Queensland, AustraliaAbstract: We present a case of osteomyelitis requiring prolonged intravenous cephalothin complicated by symptomatic calcium oxalate urocalculi formation. Patients on long-term ß-lactam antibiotics with lower urinary tract symptoms may have urolithiasis rather than a urinary tract infection.Keywords: urolithiasis, urinary tract infection, cephalothin

  4. Should probenecid be used to reduce the dicloxacillin dosage in orthopaedic infections?

    DEFF Research Database (Denmark)

    Krogsgaard, M R; Hansen, B A; Slotsbjerg, T


    times a day (dicloxacillin 500 mg) and after co-administration of 250 mg dicloxacillin and 250 mg probenecid 3 times per day (dicloxacillin 250 mg+probenecid 250 mg). Concentrations were measured every hour after the tablet intake. The mean maximum serum concentrations of dicloxacillin were 17.......1 micrograms/ml (dicloxacillin 500 mg) and 12.2 micrograms/ml (dicloxacillin 250 mg+probenecid 250 mg), respectively (P probenecid 250...... mg treatment. Serum concentrations above 5 micrograms/ml were in mean measured during 228 min. (dicloxacillin 500 mg) and 190 min. (dicloxacillin 250 mg+probenecid 250 mg), respectively (P

  5. Clinical Pharmacology of Cefamandole as Compared with Cephalothin (United States)

    Fong, Ignatius W.; Ralph, Edward D.; Engelking, Elin R.; Kirby, William M. M.


    We compared the pharmacology of cefamandole and cephalothin in six healthy adult male volunteers. After a 1-g, 20-min intravenous (i.v.) infusion, the average peak blood level of cefamandole was 87.6 versus 64.1 μg/ml for cephalothin. An i.v. infusion of 500 mg/h for 2 h (after a loading dose of 750 mg) gave an average steady-state blood level of 28.5 μg/ml for cefamandole and 18.2 μg/ml for cephalothin. Mean peak serum levels after 1 g intramuscularly were similar for the two antibiotics (about 21 μg/ml), but with cefamandole they persisted longer, and the area under the blood level curve was about 25% greater. The average t½ as determined from both i.v. studies was 34 min for cefamandole versus 30 min for cephalothin. The mean serum clearance for cephalothin, due to its partial conversion to a metabolite, was much greater than for cefamandole (425 versus 272 ml/min per 1.73 m2), but the renal clearances were similar for the two antibiotics (268 versus 257 ml/min per 1.73 m2). Other values for cefamandole and cephalothin were: 24-h urinary excretion, 80 and 66%; serum protein binding, 74 and 70%; and apparent volume of distribution, 12.8 and 18.5 liters/1.73 m2, respectively. Thus, the pharmacology of the two antibiotics was similar. Blood levels were somewhat higher with cefamandole i.v., but the results suggest that dosage regimens should be the same for the two antibiotics. PMID:1259393

  6. Dicloxacillin: a higher risk than cloxacillin for infusion phlebitis. (United States)

    Lanbeck, Peter; Odenholt, Inga; Paulsen, Otto


    Ever since dicloxacillin and cloxacillin were introduced in the 1960s, it has been known that they are associated with a high incidence of infusion phlebitis. Some in vitro studies and clinical experience have indicated that dicloxacillin is the more vessel-irritating of the 2 drugs. In this prospective observational study on 39 patients with 111 peripheral venous catheters (PVCs), the incidence of infusion phlebitis was compared between these 2 drugs. The incidence of phlebitis was 38% with dicloxacillin and 21% with cloxacillin; which, compared by logistic regression with other risk factors as covariates, was significant [odds ratio 5.06, 95% confidence interval (95% CI) 1.45-17.60]. Since the duration of catheterization is also an important risk factor, Cox regression was performed, and the difference between the 2 drugs was still significant (proportional hazard rate 3.48, 95%, CI 1.64-7.38). The only other significant risk factor found in the study was the insertion site; the risk was higher in PVCs inserted in the forearm/antecubital fossa than in the hand/wrist. The infusion time and dilution of the infusate were not significant risk factors.

  7. Flucloxacillin, a New Isoxazolyl Penicillin, Compared with Oxacillin, Cloxacillin, and Dicloxacillin (United States)

    Sutherland, R.; Croydon, E. A. P.; Rolinson, G. N.


    Flucloxacillin, a new isoxazole penicillin, is active against penicillinase-producing strains of Staphylococcus aureus and is well absorbed in man after oral and intramuscular administration. Compared with isoxazole penicillins in current clinical use—namely, oxacillin, cloxacillin, and dicloxacillin—flucloxacillin has proved as active against Gram-positive cocci, including penicillin-resistant staphylococci. The extent of binding of flucloxacillin to the protein of human serum was similar to that of oxacillin and cloxacillin and less than that of dicloxacillin. In man flucloxacillin given orally produced total and free serum levels higher than those obtained with oxacillin and cloxacillin; total serum levels similar to those of dicloxacillin, and free levels greater than those of dicloxacillin. Similarly, after intramuscular injection the free serum levels of flucloxacillin were higher than those of oxacillin, cloxacillin, and dicloxacillin. PMID:5481218

  8. Microdialysis as a tool to determine the local tissue concentration of dicloxacillin in man. (United States)

    Hansen, Kristian Kraft; Nielsen, Flemming; Stage, Tore Bjerregaard; Jørgensen, Uffe; Skov, Ole; Rasmussen, Lasse E


    The most common pathogen to cause postoperative infections in Denmark is Staphylococcus aureus. Despite using prophylactic antibiotics, infections are still seen. Whether the tissue concentration is above the minimal inhibitory concentration (MIC) for the pathogen is unknown. Thus, the concentration of dicloxacillin in muscle and adipose tissue was measured after intravenous administration, in healthy men. MIC for dicloxacillin against S. aureus was determined using the broth macrodilution method. A microdialysis (MD) catheter was placed in the subcutaneous tissue of the abdomen and in the lateral vastus muscle of the thigh of six healthy male volunteers. They were given 2 g dicloxacillin intravenously. Samples from blood and MD fluid were collected. The unbound dicloxacillin was isolated from plasma. Samples were analysed with high performance liquid chromatography (HPLC). The maximum concentration was reached in muscle tissue after 0.5 h and in adipose tissue after 0.8 h. AUC 0-6h for the dicloxacillin concentration in adipose tissue was significantly lower when compared to the unbound dicloxacillin concentration in plasma. The dicloxacillin concentration was above the MIC for sensitive S. aureus for a minimum of 2.3 h and a median of 4.1 h in muscle tissue and a minimum of 1.8 h and a median of 3.2 h in adipose tissue. The unbound dicloxacillin concentration in adipose and muscle tissue remained above the MIC for sensitive S. aureus, for a period sufficient for many orthopaedic procedures. Whether this is true in patients with compromised circulation remains to be investigated. © 2017 The British Pharmacological Society.

  9. Safety and pharmacokinetics of dicloxacillin in healthy Chinese volunteers following single and multiple oral doses

    Directory of Open Access Journals (Sweden)

    Wu GL


    Full Text Available Guolan Wu, Yunliang Zheng, Huili Zhou, Xingjiang Hu, Jian Liu, You Zhai, Meixiang Zhu, Lihua Wu, Jianzhong Shentu Research Center for Clinical Pharmacy, State Key Laboratory for Diagnosis and Treatment of Infectious Disease, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People’s Republic of China Background: Dicloxacillin, a semisynthetic isoxazolyl penicillin antibiotic, has antimicrobial activity against a wide variety of gram-positive bacteria including Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumonia, Streptococcus epidermidis, Streptococcus viridans, Streptococcus agalactiae, and Neisseria meningitidis. The objective of this study was to evaluate the safety and pharmacokinetic profile of dicloxacillin after single and multiple oral dose in healthy Chinese volunteers.Methods: A single-center, open-label, randomized, two-phase study was conducted in 16 subjects. In the single-dose phase, subjects were randomly assigned to receive single doses of 0.25, 0.5, 1.0, and 2.0 g of dicloxacillin sodium capsule in a 4-way crossover design with a 5-day washout period between administrations. In the multiple-dose phase, subjects were assigned to receive 0.25 or 0.5 g every 6 hours for 3 days in a 2-way crossover design. Plasma and urine pharmacokinetic samples were assayed by a validated high-performance liquid chromatography-tandem mass spectrometry method. Pharmacokinetic parameters were calculated and analyzed statistically. Safety assessments were conducted throughout the study.Results: Following a single oral dose of 0.25–2.0 g dicloxacillin sodium, the maximum plasma drug concentration (Cmax and the corresponding values for the area under the concentration–time curve from 0 to 10 hours (AUC0–10 h increased in a dose-proportional manner. The mean elimination half-life (t1/2 was in the range of 1.38–1.71 hours. Dicloxacillin was excreted in its unchanged form via the kidney, with no

  10. Nosocomial imipenem-resistant Acinetobacter baumannii infections ...

    African Journals Online (AJOL)

    Imipenem-resistant Acinetobacter baumannii (A. baumannii) (IRAB) has emerged as a challenging nosocomial pathogen particularly in intensive care units (ICUs). Studying the risk factors associated with IRAB infection is of paramount importance for appropriate control of IRAB spread. The aim of this study was to assess ...



    Cuevas-Ruiz B; Albarrán A; Barbero ML; Martínez-Cuevas E


    Many drugs have the side effect of dental staining may be permanent or transitory. The antibiotic Imipenem has a broad spectrum of activity against gram positive and negative which is indicated in severe infections in both adults and children.We report the case of a child who developed a transient dental staining after treatment with Imipenem

  12. In-vitro activity and beta-lactamase stability of methicillin, isoxazolyl penicillins and cephalothin against coagulase-negative staphylococci

    DEFF Research Database (Denmark)

    Jarløv, J O; Rosdahl, V T; Mortensen, I


    -level of the isoxazolyl penicillins showed a high degree of uniformity. However more strains were resistant to cloxacillin and oxacillin than to dicloxacillin and flucloxacillin. Only a weak correlation was found between beta-lactamase production, and resistance to the six antibiotics. Methicillin was the most stable...

  13. Imipenem resistance of Pseudomonas in pneumonia: a systematic literature review. (United States)

    Zilberberg, Marya D; Chen, Joyce; Mody, Samir H; Ramsey, Andrew M; Shorr, Andrew F


    Pneumonia, and particularly nosocomial (NP) and ventilator-associated pneumonias (VAP), results in high morbidity and costs. NPs in particular are likely to be caused by Pseudomonas aeruginosa (PA), ~20% of which in observational studies are resistant to imipenem. We sought to identify the burden of PA imipenem resistance in pneumonia. We conducted a systematic literature review of randomized controlled trials (RCT) of imipenem treatment for pneumonia published in English between 1993 and 2008. We extracted study, population and treatment characteristics, and proportions caused by PA. Endpoints of interest were: PA resistance to initial antimicrobial treatment, clinical success, microbiologic eradication and on-treatment emergence of resistance of PA. Of the 46 studies identified, 20 (N = 4,310) included patients with pneumonia (imipenem 1,667, PA 251; comparator 1,661, PA 270). Seven were double blind, and 7 included US data. Comparator arms included a β-lactam (17, [penicillin 6, carbapenem 4, cephalosporin 7, monobactam 1]), aminoglycoside 2, vancomycin 1, and a fluoroquinolone 5; 5 employed double coverage. Thirteen focused exclusively on pneumonia and 7 included pneumonia and other diagnoses. Initial resistance was present in 14.6% (range 4.2-24.0%) of PA isolates in imipenem and 2.5% (range 0.0-7.4%) in comparator groups. Pooled clinical success rates for PA were 45.2% (range 0.0-72.0%) for imipenem and 74.9% (range 0.0-100.0%) for comparator regimens. Microbiologic eradication was achieved in 47.6% (range 0.0%-100.0%) of isolates in the imipenem and 52.8% (range 0.0%-100.0%) in the comparator groups. Resistance emerged in 38.7% (range 5.6-77.8%) PA isolates in imipenem and 21.9% (range 4.8-56.5%) in comparator groups. In the 15 years of RCTs of imipenem for pneumonia, PA imipenem resistance rates are high, and PA clinical success and microbiologic eradication rates are directionally lower for imipenem than for comparators. Conversely, initial and treatment

  14. Imipenem for the treatment of melioidosis. (United States)

    Minassian, M A; Gage, A; Price, E; Sefton, A M


    Melioidosis is a protean disease caused by Burkholderia pseudomallei. It is rare in the UK and is generally only seen in patients with a travel history to endemic areas such as Thailand, Singapore and Malaysia. Cases may present with disseminated bacteraemic, non-disseminated bacteraemic, multi-focal bacteraemic or localized disease. Subclinical infections also occur. Following acquisition of the organism a patient may remain asymptomatic for several years before infection becomes clinically apparent. Factors such as diabetes, renal failure or other causes for a decrease in host immunity may precipitate the appearance of overt disease. The current treatment choice for severe melioidosis is parenteral ceftazidime followed by oral amoxycillin-clavulanic acid or a combination of co-trimoxazole, doxycycline and chloramphenicol. We report a case of melioidosis in a 59-year-old male diabetic from Bangladesh who initially responded to piperacillin-tazobactam but was changed to ceftazidime when a definitive diagnosis was made. His condition deteriorated on the latter antibiotic. He subsequently responded to imipenem. The patient's long-term outcome is still not known.

  15. [Clinical experience with imipenem-cilastatin in intensive therapy]. (United States)

    Verre, M; D'Antona, R; Macrina, E


    The authors describe their experience with imipenem-cilastatin in 36 patients in critical conditions due to multiresistant bacterial infections. The efficacy and tolerability of the antibiotic are stressed.

  16. Combination therapy with thioridazine and dicloxacillin combats meticillin-resistant Staphylococcus aureus infection in Caenorhabditis elegans

    DEFF Research Database (Denmark)

    Poulsen, Marianne Ø; Schøler, Lone; Nielsen, Anette


    The shortage of drugs active against meticillin-resistant Staphylococcus aureus (MRSA) is a growing clinical problem. In vitro studies indicate that the phenothiazine thioridazine (TZ) might enhance the activity of the β-lactam antibiotic dicloxacillin (DCX) to a level where MRSA is killed......, but experiments in simple animal models have not been performed. In the present study, we introduced Caenorhabditis elegans infected by S. aureus as an in vivo model to test the effect of TZ as a helper drug in combination with DCX. Because TZ is an anthelmintic, initial experiments were carried out to define...... the thresholds of toxicity, determined by larval development, and induction of stress-response markers. No measurable effects were seen at concentrations of less than 64 mg TZ l(-1). Seven different MRSA strains were tested for pathogenicity against C. elegans, and the most virulent strain (ATCC 33591...

  17. Effectiveness of penicillin, dicloxacillin and cefuroxime for penicillin-susceptible Staphylococcus aureus bacteraemia

    DEFF Research Database (Denmark)

    Nissen, Jette Lindbjerg; Skov, Robert; Knudsen, Inge Jenny Dahl


    OBJECTIVES: Penicillin-susceptible Staphylococcus aureus isolates account for a fifth of cases of S. aureus bacteraemia (SAB) in Denmark, but little is known about treatment outcomes with penicillins or other antimicrobials. Here we compare penicillin, dicloxacillin and cefuroxime as definitive...... treatments in relation to 30 day mortality. METHODS: A retrospective chart review of 588 penicillin-susceptible S. aureus cases at five centres from January 1995 to December 2010. Data on demographics, antimicrobial treatment, clinical signs and symptoms, and mortality at day 30 were collected. Hazard ratios...... compared with penicillin (adjusted HR 2.54, 95% CI 1.49-4.32). Other variables that were statistically significantly associated with 30 day mortality included increasing age, disease severity and a primary respiratory focus. Osteomyelitis/arthritis was associated with a lower risk of death than were other...

  18. Synthesis, characterization and antibacterial activity of a tridentate Schiff base derived from cephalothin and sulfadiazine, and its transition metal complexes. (United States)

    Anacona, J R; Noriega, Natiana; Camus, Juan


    Metal(II) coordination compounds of a cephalothin Schiff base (H2L) derived from the condensation of cephalothin antibiotic with sulfadiazine were synthesized. The Schiff base ligand, mononuclear [ML(H2O)3] (M(II)=Mn,Co,Ni,Zn) complexes and magnetically diluted dinuclear copper(II) complex [CuL(H2O)3]2 were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and (1)H NMR spectral studies. The cephalothin Schiff base ligand H2L behaves as a dianionic tridentate NOO chelating agent. The biological applications of complexes have been studied on two bacteria strains (Escherichia coli and Staphylococcus aureus) by agar diffusion disc method. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Relative efficacy of cefuroxime versus dicloxacillin as definitive antimicrobial therapy in methicillin-susceptible Staphylococcus aureus bacteraemia

    DEFF Research Database (Denmark)

    Rasmussen, Jon Bjarke; Knudsen, Jenny Dahl; Arpi, Magnus


    OBJECTIVES: The objective of the present study was to compare the efficacy of cefuroxime with that of dicloxacillin as definitive antimicrobial therapy in methicillin-susceptible Staphylococcus aureus bacteraemia (MS-SAB) using a Danish bacteraemia database, information on the indication for anti......OBJECTIVES: The objective of the present study was to compare the efficacy of cefuroxime with that of dicloxacillin as definitive antimicrobial therapy in methicillin-susceptible Staphylococcus aureus bacteraemia (MS-SAB) using a Danish bacteraemia database, information on the indication......-adjusted Cox proportional hazards regression analyses. In addition, PS matching was performed. RESULTS: A total of 691 patients with MS-SAB received either dicloxacillin (n = 368) or cefuroxime (n = 323) as definitive antimicrobial therapy. Twenty-eight different indications for empirical antimicrobial therapy...... were identified and grouped into eight categories. There was no statistically significant difference in 30 day mortality between the two groups (HR 1.02, 95% CI 0.68-1.52). Definitive antimicrobial therapy with cefuroxime was associated with increased 90 day mortality in a PS-adjusted multivariate...

  20. Tobramycin-clindamycin versus cephalothin-cephalexin in the treatment of appendicular peritonitis. (United States)

    Gripenberg, L; Nuutinen, P; Elo, J; Tallgren, L G


    Forty-seven children, ages 1 to 14 years, with appendicular peritonitis were randomly divided into two groups: 27 were treated with the combination tobramycin-clindamycin and 20 with cephalothin followed by cephalexin. The overall rate of complications was 32%. Patients who had had their symptoms for less than 48 hours before being admitted to hospital had significantly fewer complications than those whose symptoms had lasted longer. Patients treated with tobramycin-clindamycin had significantly fewer wound infections. As clindamycin is effective against anaerobes this observation supports the view that anaerobes play an important role in the infectious complications in peritonitis. In this series, 12 species of aerobes and eight species of anaerobes were cultured from peritoneal fluid. In eight patients only one species was isolated; in the remaining 39 patients 29 different combinations of bacteria were encountered. Early diagnosis and administration of antibiotics preoperatively or during surgery, including clindamycin, metronidazol or tinidazol is recommended in the treatment of children with appendicular peritonitis.

  1. Radical-scavenging activity of penicillin G, ampicillin, oxacillin, and dicloxacillin. (United States)

    Berczyński, Paweł; Kładna, Aleksandra; Kruk, Irena; Aboul-Enein, Hassan Y


    The aim of this study was to characterize the antioxidant activity of penicillin G (PG), ampicillin (AMP), oxacillin (OX) and dicloxacillin (DOX) through their reactivity towards reactive oxygen species (superoxide anion radical, O2•̅; hydroxyl radical, HO(•) ; peroxyl radical, ROO(•) ; hydrogen peroxide, H2 O2 ; DPPH(•) ) using various in vitro antioxidant assays with chemiluminescence (CL) and spectrophotometry as measurement techniques. In hydroxyl radical assays , PG, OX and AMP were found to inhibit the CL signal arising from the Fenton-like reaction in a dose-dependent manner with IC50  = 0.480 ± 0.020 mM, IC50  = 0.569 ± 0.021 mM, and IC50  = 0.630 ± 0.019 mM, respectively. The highest reactivity of PG among the tested penicillins towards the HO radical was confirmed in the deoxyribose degradation assay. In the ABAP-derived ROO radical assay, the radical-scavenging ability of the test penicillins was in the following order: AMP > PG > DOX > OX. The number of reduced DPPH radicals by the drugs tested was <1 being the biggest for PG. The weak antioxidant capacity of the test penicillins was confirmed in the trolox antioxidant capacity assay (0.075 ± 0.004; 0.093 ± 0.006; 0.123 ± 0.005; 0.126 ± 0.004) for OX, AMP, DOX, PG, respectively. Use of luminol as a CL probe for estimation of penicillin reactivity towards H2 O2 showed that only AMP was able to quench light emission; the remaining antibiotics demonstrated a strong enhancing effect. All the examined compounds showed a weak antioxidant potential when estimated using the ferric-ferrozine assay. This study is the first to report the evaluation of test penicillins as antioxidants under the same reaction conditions. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Pooled population pharmacokinetic model of imipenem in plasma and the lung epithelial lining fluid. (United States)

    van Hasselt, J G Coen; Rizk, Matthew L; Lala, Mallika; Chavez-Eng, Cynthia; Visser, Sandra A G; Kerbusch, Thomas; Danhof, Meindert; Rao, Gauri; van der Graaf, Piet H


    Several clinical trials have confirmed the therapeutic benefit of imipenem for treatment of lung infections. There is however no knowledge of the penetration of imipenem into the lung epithelial lining fluid (ELF), the site of action relevant for lung infections. Furthermore, although the plasma pharmacokinetics (PK) of imipenem has been widely studied, most studies have been based on selected patient groups. The aim of this analysis was to characterize imipenem plasma PK across populations and to quantify imipenem ELF penetration. A population model for imipenem plasma PK was developed using data obtained from healthy volunteers, elderly subjects and subjects with renal impairment, in order to identify predictors for inter-individual variability (IIV) of imipenem PK. Subsequently, a clinical study which measured plasma and ELF concentrations of imipenem was included in order to quantify lung penetration. A two compartmental model best described the plasma PK of imipenem. Creatinine clearance and body weight were included as subject characteristics predictive for IIV on clearance. Typical estimates for clearance, central and peripheral volume, and inter-compartmental clearance were 11.5 l h(-1) , 9.37 l, 6.41 l, 13.7 l h(-1) , respectively (relative standard error (RSE) <8%). The distribution of imipenem into ELF was described using a time-independent penetration coefficient of 0.44 (RSE 14%). The identified lung penetration coefficient confirms the clinical relevance of imipenem for treatment of lung infections, while the population PK model provided insights into predictors of IIV for imipenem PK and may be of relevance to support dose optimization in various subject groups. © 2016 The British Pharmacological Society.

  3. Effect of imipenem and sulbactam on sessile cells of Acinetobacter baumannii growing in biofilm. (United States)

    Vidal, R; Dominguez, M; Urrutia, H; Bello, H; Garcia, A; Gonzalez, G; Zemelman, R


    The effect of the age of biofilms formed by Acinetobacter baumannii on the activity of sulbactam and imipenem on sessile cells was investigated. Against cells of young biofilms both antibiotics were rapidly bactericidal. As the biofilm aged, sulbactam lost most of its activity, but imipenem continued to be bactericidal to some extent. This fact probably reflects the ability of imipenem to exert bactericidal activity on slow-growing bacteria.

  4. Structural Milestones in the Reaction Pathway of an Amide Hydrolase: Substrate, Acyl, and Product Complexes of Cephalothin with AmpC [beta]-Lactamase

    Energy Technology Data Exchange (ETDEWEB)

    Beadle, Beth M.; Trehan, Indi; Focia, Pamela J.; Shoichet, Brian K. (NWU)


    {beta}-lactamases hydrolyze {beta}-lactam antibiotics and are the leading cause of bacterial resistance to these drugs. Although {beta}-lactamases have been extensively studied, structures of the substrate-enzyme and product-enzyme complexes have proven elusive. Here, the structure of a mutant AmpC in complex with the {beta}-lactam cephalothin in its substrate and product forms was determined by X-ray crystallography to 1.53 {angstrom} resolution. The acyl-enzyme intermediate between AmpC and cephalothin was determined to 2.06 {angstrom} resolution. The ligand undergoes a dramatic conformational change as the reaction progresses, with the characteristic six-membered dihydrothiazine ring of cephalothin rotating by 109{sup o}. These structures correspond to all three intermediates along the reaction path and provide insight into substrate recognition, catalysis, and product expulsion.

  5. Comparative neurotoxicity of benzylpenicillin, imipenem/cilastatin and FCE 22101, a new injectible penem. (United States)

    Schliamser, S E; Broholm, K A; Liljedahl, A L; Norrby, S R


    Rabbits were given benzylpenicillin, imipenem/cilastatin and a penem beta-lactam, FCE 22101, as constant intravenous infusions with intervals of greater than or equal to 7 days between doses. Neurotoxicity was defined as epileptogenic electroencephalographic (EEG) activity. Mean doses precipitating neurotoxicity were 486 mg/kg of benzylpenicillin, 86 mg/kg of imipenem and 102 mg/kg of FCE 22101 leading to mean serum concentrations of 606, 55 and 30 mg/l, respectively. Doses and serum concentrations of benzylpenicillin were significantly (P less than 0.001) higher than those of imipenem or FCE 22101. Neurotoxicity was seen at significantly (P less than 0.02) higher serum concentrations of imipenem than of FCE 22101. Neurotoxicity seemed to be related to antibiotic concentrations in brain tissue fluid (BTF) rather than to CSF concentrations which were less than 0.2 mg/l in 10 of 11 animals tested after administration of imipenem or FCE 22101. In BTF, significantly (P less than 0.001) higher concentrations of benzylpenicillin than of imipenem or FCE 22101 were found. When related to concurrent serum concentrations, BTF penetration of benzylpenicillin and FCE 22101 did not differ significantly but both these antibiotics penetrated significantly better than imipenem. In conclusion, imipenem/cilastatin and FCE 22101 were more neurotoxic in rabbits than benzylpenicillin but did not show major differences from each other.

  6. Pharmacokinetics/pharmacodynamics of colistin and imipenem on mucoid and nonmucoid Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Hengzhuang, Wang; Wu, Hong; Ciofu, Oana


    The time course of activity of colistin and imipenem against mucoid and nonmucoid Pseudomonas aeruginosa growing in a biofilm showed that compared with those for planktonic bacteria, the kinetics of colistin and imipenem retained the concentration- and time-dependent killing, respectively...

  7. Effectiveness of penicillin, dicloxacillin and cefuroxime for penicillin-susceptible Staphylococcus aureus bacteraemia: a retrospective, propensity-score-adjusted case-control and cohort analysis. (United States)

    Nissen, Jette Lindbjerg; Skov, Robert; Knudsen, Jenny Dahl; Ostergaard, Christian; Schønheyder, Henrik Carl; Frimodt-Møller, Niels; Benfield, Thomas


    Penicillin-susceptible Staphylococcus aureus isolates account for a fifth of cases of S. aureus bacteraemia (SAB) in Denmark, but little is known about treatment outcomes with penicillins or other antimicrobials. Here we compare penicillin, dicloxacillin and cefuroxime as definitive treatments in relation to 30 day mortality. A retrospective chart review of 588 penicillin-susceptible S. aureus cases at five centres from January 1995 to December 2010. Data on demographics, antimicrobial treatment, clinical signs and symptoms, and mortality at day 30 were collected. Hazard ratios (HRs) with 95% CIs associated with mortality were modelled using propensity-score-adjusted Cox proportional hazards regression analysis. Propensity-score-matched case-control studies were carried out. Definitive therapy with cefuroxime was associated with an increased risk of 30 day mortality compared with penicillin (adjusted HR 2.54, 95% CI 1.49-4.32). Other variables that were statistically significantly associated with 30 day mortality included increasing age, disease severity and a primary respiratory focus. Osteomyelitis/arthritis was associated with a lower risk of death than were other secondary manifestations. Propensity-score-matched case-control studies confirmed an increased risk of 30 day mortality: cefuroxime treatment (39%) versus penicillin treatment (20%), P = 0.037; and cefuroxime treatment (38%) versus dicloxacillin treatment (10%), P = 0.004. Definitive therapy for penicillin-susceptible SAB with cefuroxime was associated with a significantly higher mortality than was seen with therapy with penicillin or dicloxacillin.

  8. A study of the adsorption of the amphiphilic penicillins cloxacillin and dicloxacillin onto human serum albumin using surface tension isotherms (United States)

    Barbosa, Silvia; Leis, David; Taboada, Pablo; Attwood, David; Mosquera, Victor

    The interaction of human serum albumin (HSA) with two structurally similar anionic amphiphilic penicillins, cloxacillin and dicloxacillin, at 25°C has been examined by surface tension measurements under conditions at which the HSA molecule was positively (pH 4.5) or negatively charged (pH 7.4). Measurements were at fixed HSA concentrations (0.0125 and 0.125% w/v) and at drug concentrations over a range including, where possible, the critical micelle concentration (cmc). Interaction between anionic drugs and positively charged HSA at pH 7.4 resulted in an increase of the cmc of each drug as a consequence of its removal from solution by adsorption. Limited data for cloxacillin at pH 4.5 indicated an apparent decrease of the cmc in the presence of HSA suggesting a facilitation of the aggregation by association with the protein. Changes in the surface tension-log (drug concentration) plots in the presence of HSA have been discussed in terms of the adsorption of drug at the air-solution and protein-solution interfaces. Standard free energy changes associated with the micellization of both drugs and their adsorption at the air-solution interface have been calculated and compared.

  9. Fatal pneumonia and empyema thoracis caused by imipenem-resistant Nocardia abscessus in a cancer patient. (United States)

    Lai, Chih-Cheng; Tsai, Hsih-Yeh; Ruan, Sheng-Yuan; Liao, Chun-Hsing; Hsueh, Po-Ren


    We describe a case of pneumonia and empyema thoracis caused by trimethoprim-sulfamethoxazole-susceptible, but imipenem-resistant Nocardia abscessus in a cancer patient. The isolate was confirmed to the species level by 16S rRNA sequencing analysis. The patient did not respond to antibiotic therapy, including ceftriaxone and imipenem, and died of progressing pneumonia and multiple organ failure. Copyright © 2013. Published by Elsevier B.V.

  10. Signal Detection of Imipenem Compared to Other Drugs from Korea Adverse Event Reporting System Database


    Park, Kyounghoon; Soukavong, Mick; Kim, Jungmee; Kwon, Kyoung-Eun; Jin, Xue-Mei; Lee, Joongyub; Yang, Bo Ram; Park, Byung-Joo


    Purpose To detect signals of adverse drug events after imipenem treatment using the Korea Institute of Drug Safety & Risk Management-Korea adverse event reporting system database (KIDS-KD). Materials and Methods We performed data mining using KIDS-KD, which was constructed using spontaneously reported adverse event (AE) reports between December 1988 and June 2014. We detected signals calculated the proportional reporting ratio, reporting odds ratio, and information component of imipenem. We d...

  11. Risk factors for imipenem-nonsusceptible Acinetobacter nosocomialis bloodstream infection. (United States)

    Huang, Lei; Chen, Te-Li; Lee, Yi-Tzu; Lee, Mei-Hui; Kuo, Shu-Chen; Yu, Kwok-Woon; Dou, Horng-Yunn; Fung, Chang-Phone


    The emergence of imipenem-nonsusceptible (INS) Acinetobacter baumannii complex has had a great impact on healthcare systems worldwide. Understanding the risk factors related to INS infection is useful for infection control. The risk factors for INS A. baumannii have been well documented; however, the risk factors related to INS Acinetobacter nosocomialis infection lack documentation. The purpose of this study was to identify the risk factors associated with INS A. nosocomialis bacteremia. This retrospective 9-year study included 329 adults with A. nosocomialis bacteremia in a tertiary medical center in Taiwan. Acinetobacter nosocomialis was identified using a multiplex polymerase chain reaction method and sequence analysis of a 16S-23S intergenic spacer. Among 329 patients with A. nosocomialis bacteremia, 67 had INS isolates (20.4%). Patients with INS isolates tended to have a more severe form of the diseases [with ICU admission and a higher APACHE (Acute Physiology and Chronic Health Evaluation) II score], specific underlying diseases (associated with chronic lung diseases and end-stage renal diseases, but less commonly alcoholism and chemotherapy), multiple invasive procedures, pneumonia as a primary focus of infection, and prior antimicrobial use (sulbactam, antipseudomonal penicillins, aminoglycosides, and carbapenems). Multivariable analysis showed that ICU admission, chronic lung diseases, arterial line catheterization, total parenteral nutrition, and prior use of carbapenems were independent risk factors; prior use of carbapenems was found to be the most influential (odds ratio 6.36, 95% confidence interval 2.00-20.21; p = 0.002). To our knowledge, this is the first study describing the risk factors associated with INS A. nosocomialis bacteremia. Regulated antibiotic control policy, especially for carbapenem, and infection control measures targeting patients hospitalized in ICU, with chronic lung diseases and multiple invasive procedures, may be helpful in

  12. Imipenem-induced clostridium difficile diarrhea in a patient with chronic renal failure

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    R Enríquez


    Full Text Available An 80-year-old man was diagnosed to have pneumonia and advanced chronic kidney disease. He presented with anuria and hemodialysis, by temporary femoral catheter, was initiated. He was empirically treated with imipenem/cilastatin 500 mg/24 h after hemodialysis. After 10 days of antibiotic intake, he developed severe diarrhea. Diagnosis of Clostridium difficile (CD-associated diarrhea was confirmed by detection of the toxins A and B in his stool. Imipenem therapy was discontinued; Vancomycin 500 mg orally every 6 h and 1000 mg per rectum every day was added. After two weeks of this treatment, the patient reported complete resolution of the diarrhea and stool samples were negative for Clostridium toxin. In this case, the most possible cause of CD colitis was considered to be imipenem because of the temporal relationship between exposure to the drug and onset of symptoms.

  13. Comparative Analysis of Three Methods for Determination of Imipenem Resistance in Pseudomonas aeruginosa

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    Tanaz Zabihi


    Full Text Available "> Background: These days, the antibiotic resistance of Pseudomonas aeruginosa isolates toimipenem has significantly increased. Therefore the study of resistance to imipenem in thisorganism to imipenem in determining the appropriate treatment is crucial and necessary. The goalof this study is to compare three phenotypic methods of E-test, disk diffusion and micro brothdilution in the study of resistance to imipenem in clinical isolates of P. aeruginosa.Methods: Within a 6-month interval, 120 clinical specimens were collected and evaluated. Allisolates were identified as P. aeruginosa by standard biochemical tests and amplification of 16SrRNA gene. Three phenotypic methods of E-test, disk diffusion, and micro broth dilution wereused to determine imipenem resistance in P. aeruginosa isolates.Results: Of the 96 P. aeruginosa isolates studied for their resistance to imipenem by the use ofE-test, disk diffusion and micro broth dilution methods, 38.5% of the strains in micro broth dilutionmethod and 33.3% in the two methods of E-test and disk diffusion were resistant to imipenem. Therate of sensitivity and specificity of disk diffusion and E-test methods were 100%, 90.1%, and theywere 100% and 83.1% for micro broth dilution, respectively.Conclusions: With regard to the results obtained from the comparison of the three methods100% agreement were observed among the antimicrobial susceptibility results obtained by the Etest and disk diffusion methods (P ≥ 0.05. Therefore, the use of disk diffusion method can bean appropriate replacement for E-test method with regard to its being easy and cost-effective.

  14. Phenotypic and Genotypic Detection of Metallo-beta-lactamases among Imipenem-Resistant Gram Negative Isolates

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    Mohammad Mohammadzadeh


    Full Text Available Background:   Imipenem-resistant gram negative bacteria, resulting from metallo-beta-lactamase (MBLs-producing strains have been reported to be among the important causes of nosocomial infections and of serious therapeutic problem worldwide. Because of their broad range, potent carbapenemase activity and resistance to inhibitors, these enzymes can confer resistance to almost all beta-lactams. The prevalence of metallo-beta-lactamase among imipenem-resistant Acinetobacter spp., Pseudomonas spp. and Enerobacteriaceae isolates is determined.Methods:   In this descriptive study 864 clinical isolates of Acinetobacter spp., Pseudomonas spp. and Enterobacteriaceae, were initially tested for imipenem susceptibility. The metallo-beta-lactamase production was detected using combined disk diffusion, double disk synergy test, and Hodge test. Then all imipenem resistant isolates were tested by PCR for imp, vim and ndm genes. Results:   Among 864 isolates, 62 (7.17 % were imipenem-resistant. Positive phonetypic test for metallo-beta-lactamase was 40 (64.5%, of which 24 (17.1% and 16 (9.2% isolates were Acinetobacter spp. and Pseudomonas spp., respectively. By PCR method 30 (48.4% of imipenem resistant Acinetobacter, and Pseudomonas isolates were positive for MBL-producing genes. None of the Enterobacteriaceae isolates were positive for metallo-beta-lactamase activity. Conclusion:   The results of this study are indicative of the growing number of nosocomial infections associated with multidrug-resistant gram negative bacteria in this region leading to difficulties in antibiotic therapy. Thereby, using of phenotypic methods can be helpful for management of this problem.

  15. Control of imipenem resistant-Klebsiella pneumoniae pulmonary infection by oral treatment using a combination of mycosynthesized Ag-nanoparticles and imipenem

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    Marwa M. Abdel-Aziz


    Full Text Available Klebsiella pneumoniae (Kp a common cause of pneumonia leads to intense lung injury and mortality that are correlated with infective exacerbations. A significant increase in the prevalence of imipenem resistant K. pneumoniae (IRKP has been observed in common human pathogens. The rapid emergence of IRKP has limited the availability of anti-bacterial treatment options. Silver nano-particles (AgNPs are one of the well-known antibacterial substances showing such multimode antibacterial action. Therefore, AgNPs are suitable candidates for use in combinations with imipenem in order to improve its antibacterial action. Fifteen fungal species were screened for mycosynthesis of silver nanoparticles (AgNPs, only eight fungal species were found to reduce the silver salt into silver nanoparticles which was characterized by UV–visible spectrophotometric analysis, Energy Dispersive Analysis of X-ray (EDX and transmission electron microscopy. Consistent with characterized silver nanoparticles, mycosynthesized AgNPs by Verticillium albo-atrum (RCMB 039001 was found the higher in concentration (as detected by UV–visible spectrophotometric analysis and the least in size (as detected by TEM analysis so, it was chosen for further studies such as in vitro antibacterial activity against Imipenem resistant K. pneumonia (IRKP, MIC, FIC measurements and in vivo study. In this work a strong synergistic antibacterial effect between AgNPs and imipenem was detected in vitro (with FIC Index 0.07 and in vivo against IRKP strain. These results suggested that sliver nanoparticles have an effective antibacterial action on bacterial count, histopathology as well as protective immune response in an IRKP rat model.

  16. Effect of imipenem on monoclonal antibody-mediated protection against Escherichia coli O18K5.


    Frasa, H; Benaissa-Trouw, B.; Tavares, L.; Kessel, K; Hustinx, W; Schellekens, J; Kraaijeveld, K; Verhoef, J.


    Flow cytometry revealed that the binding of immunoglobulin M monoclonal antibodies (MAbs) to Escherichia coli O18K5 was modulated by exposure of the bacteria to subinhibitory concentrations of imipenem. The binding of anti-K5 MAb was decreased, while the binding of anti-O18 MAb was increased. In addition, anti-lipid A MAbs bound only to imipenem-treated bacteria. The biological effect of MAb binding was investigated in BALB/c mice by determination of the levels of bacteremia, tumor necrosis f...

  17. [Activity of imipenem and meropenem against strains of Acinetobacter baumannii isolated from various Chilean hospitals]. (United States)

    Bello, H; Domínguez, M; Sepúlveda, M; Cerda, F; González, G; Mella, S; Zemelman, R


    The activity of two carbapenem compounds, imipenem and meropenem, against 447 strains of Acinetobacter baumannii isolated between 1990 and 1998 in different Chilean hospitals was determined. MIC ranges, MIC(50) and MIC(90), were determined by an agar dilution method. Similar antibacterial activities were observed for both antibacterials; however, a slight increase in the MIC(50) of imipenem and meropenem, and in the MIC(90) of meropenem was found among strains isolated from 1997-1998. Although A. baumannii remains susceptible to these antibiotics, the MIC(50) and MIC(90) have increased in recent years.

  18. Ofloxacin and imipenem in the treatment of Mycobacterium fortuitum and Mycobacterium chelonae lung infections. (United States)

    Yew, W W; Kwan, S Y; Wong, P C; Lee, J


    Two patients with Mycobacterium fortuitum and one patient with Mycobacterium chelonae lung infections were treated with ofloxacin and imipenem respectively. Of the former two, one had underlying inactive pulmonary tuberculosis and bronchiectasis and the other had silicosis. The latter had severe underlying bronchiectasis also. The treatments were well tolerated and the patients responded well.

  19. Signal Detection of Imipenem Compared to Other Drugs from Korea Adverse Event Reporting System Database. (United States)

    Park, Kyounghoon; Soukavong, Mick; Kim, Jungmee; Kwon, Kyoung Eun; Jin, Xue Mei; Lee, Joongyub; Yang, Bo Ram; Park, Byung Joo


    To detect signals of adverse drug events after imipenem treatment using the Korea Institute of Drug Safety & Risk Management-Korea adverse event reporting system database (KIDS-KD). We performed data mining using KIDS-KD, which was constructed using spontaneously reported adverse event (AE) reports between December 1988 and June 2014. We detected signals calculated the proportional reporting ratio, reporting odds ratio, and information component of imipenem. We defined a signal as any AE that satisfied all three indices. The signals were compared with drug labels of nine countries. There were 807582 spontaneous AEs reports in the KIDS-KD. Among those, the number of antibiotics related AEs was 192510; 3382 reports were associated with imipenem. The most common imipenem-associated AE was the drug eruption; 353 times. We calculated the signal by comparing with all other antibiotics and drugs; 58 and 53 signals satisfied the three methods. We compared the drug labelling information of nine countries, including the USA, the UK, Japan, Italy, Switzerland, Germany, France, Canada, and South Korea, and discovered that the following signals were currently not included in drug labels: hypokalemia, cardiac arrest, cardiac failure, Parkinson's syndrome, myocardial infarction, and prostate enlargement. Hypokalemia was an additional signal compared with all other antibiotics, and the other signals were not different compared with all other antibiotics and all other drugs. We detected new signals that were not listed on the drug labels of nine countries. However, further pharmacoepidemiologic research is needed to evaluate the causality of these signals.

  20. Determination of benzylpenicillin, oxacillin, cloxacillin, and dicloxacillin in cows' milk by ion-pair high-performance liquid chromatography after precolumn derivatization. (United States)

    Marchetti, M; Schwaiger, I; Schmid, E R


    A high-performance liquid-chromatographic method has been developed for the determination of five penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, oxacillin, cloxacillin, and dicloxacillin) at trace levels in commercially available milk samples. This method comprises extraction of the lipids with ethyl acetate, clean-up and concentration on a C-18 solid-phase extraction column, and derivatization with 1,2,4-triazole and mercury(II) chloride solution, pH 8, at 65 degrees C for 10 min. The derivatized compounds are eluted from a C-2 column with a mobile phase containing acetonitrile and phosphate buffer loaded with sodium thiosulfate and tetrabutylammonium hydrogen sulfate as ion-pairing reagent. The limit of determination was found to be 4 microg L(-1) milk for benzylpenicillin and 10 microg L(-1) for the others. This meets EU criteria according to decision No. 93/256/EEC.

  1. Characterization of imipenem resistance mechanisms in Pseudomonas aeruginosa isolates from Turkey. (United States)

    Mac Aogáin, M; Kulah, C; Rijnsburger, M; Celebi, G; Savelkoul, P H M; O'Gara, F; Mooij, M J


    The emergence of carbapenem resistance in Pseudomonas aeruginosa threatens the efficacy of this important anti-pseudomonal antibiotic class. Between 2003 and 2006, an increase in the number of carbapenem-resistant P. aeruginosa isolates at the Zonguldak Karaelmas University Hospital was observed (Zonguldak, Turkey). To assess the imipenem resistance mechanisms emerging in these P. aeruginosa isolates, they were characterized by amplified fragment length polymorphism typing, which revealed diversity among imipenem-resistant isolates as well as two clonally related outbreak groups. The molecular mechanism of carbapenem resistance was characterized in a representative isolate from each clonal group. Mutational disruption of oprD was the most frequently encountered resistance mechanism (23/27 isolates). © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

  2. Activity of Imipenem against Klebsiella pneumoniae Biofilms In Vitro and In Vivo (United States)


    Activity of Imipenem against Klebsiella pneumoniae Biofilms In Vitro and In Vivo Ping Chen,a Akhil K. Seth,b Johnathan J. Abercrombie,a Thomas A...USAa; Division of Plastic Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USAb Encapsulated Klebsiella pneumoniae has... Klebsiella pneumoniae is a Gram-negative, encapsulated, non-motile, rod-shaped opportunistic pathogen. This organism can cause a wide range of

  3. Emergence of Imipenem-Resistant Gram-Negative Bacilli in Intestinal Flora of Intensive Care Patients (United States)

    Angebault, Cécile; Barbier, François; Hamelet, Emilie; Defrance, Gilles; Ruppé, Etienne; Bronchard, Régis; Lepeule, Raphaël; Lucet, Jean-Christophe; El Mniai, Assiya; Wolff, Michel; Montravers, Philippe; Plésiat, Patrick; Andremont, Antoine


    Intestinal flora contains a reservoir of Gram-negative bacilli (GNB) resistant to cephalosporins, which are potentially pathogenic for intensive care unit (ICU) patients; this has led to increasing use of carbapenems. The emergence of carbapenem resistance is a major concern for ICUs. Therefore, in this study, we aimed to assess the intestinal carriage of imipenem-resistant GNB (IR-GNB) in intensive care patients. For 6 months, 523 consecutive ICU patients were screened for rectal IR-GNB colonization upon admission and weekly thereafter. The phenotypes and genotypes of all isolates were determined, and a case control study was performed to identify risk factors for colonization. The IR-GNB colonization rate increased regularly from 5.6% after 1 week to 58.6% after 6 weeks in the ICU. In all, 56 IR-GNB strains were collected from 50 patients: 36 Pseudomonas aeruginosa strains, 12 Stenotrophomonas maltophilia strains, 6 Enterobacteriaceae strains, and 2 Acinetobacter baumannii strains. In P. aeruginosa, imipenem resistance was due to chromosomally encoded resistance (32 strains) or carbapenemase production (4 strains). In the Enterobacteriaceae strains, resistance was due to AmpC cephalosporinase and/or extended-spectrum β-lactamase production with porin loss. Genomic comparison showed that the strains were highly diverse, with 8 exceptions (4 VIM-2 carbapenemase-producing P. aeruginosa strains, 2 Klebsiella pneumoniae strains, and 2 S. maltophilia strains). The main risk factor for IR-GNB colonization was prior imipenem exposure. The odds ratio for colonization was already as high as 5.9 (95% confidence interval [95% CI], 1.5 to 25.7) after 1 to 3 days of exposure and increased to 7.8 (95% CI, 2.4 to 29.8) thereafter. In conclusion, even brief exposure to imipenem is a major risk factor for IR-GNB carriage. PMID:23318796


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    Gloria Narjara Santos da Silva


    Full Text Available α-Curcumene was isolated from the fresh aerial parts of Senecio selloi Spreng. DC. and its activity against bacteria, yeasts and an alga was inspected by the applying the microdilution method. The strongest effect was manifested against Saccharomyces cerevisiae with estimated values of MIC and MFC 0.8 mg/mL. The α-curcumene synergism in the concentrations of 1 mM and 5 mM, respectively, with selected antibiotics (ciprofloxacin, imipenem, ceftazidim and a combination of amoxicillin and clavulanic acid was investigated against Staphylococcus aureus, Escherichia coli, Enterobacter cloacae, Staphylococcus haemolyticus and Klebsiella pneumoniae by the disk diffusion assay. The results have shown the occurrence of synergism of α-curcumene with imipenem against the clinical isolate E. cloacae with a significance level of p> 0.05. Based on these informations it can be concluded that fungal strains are more sensitive for α-curcumene than the bacterial ones and the synergism of α-curcumene with imipenem can improve the antibiotic efficiency against the E. cloacae.

  5. Evaluation of the pharmacokinetics of imipenem following regional limb perfusion using the saphenous and the cephalic veins in standing horses. (United States)

    Kelmer, G; Tatz, A J; Kdoshim, E; Britzi, M; Segev, G


    This prospective experimental study goal was to determine the pharmacokinetics of imipenem after intravenous regional limb perfusion (IV-RLP) in standing horses. Nine horses participated in the study; that was approved by the University Animal Care and Use Committee. One thoracic limb or one pelvic limb of each horse was randomly selected. After the veins were catheterized, an Esmarch bandage tourniquet was applied and the catheter was injected with a solution containing 500mg of imipenem. Synovial fluid samples were collected from the fetlock joint and blood samples were collected from the jugular vein. All samples were analyzed for imipenem concentration using liquid chromatography mass spectrometry. Cmax of imipenem in the fetlock joint using the cephalic and the saphenous vein was 87 and 60μg⁄mL, respectively. The results indicate that by performing IV-RLP using the cephalic/saphenous, one can achieve imipenem concentrations in the fetlock joint that are well above the MIC of most susceptible pathogens including resistant bacteria such as Methicillin Resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Thus, with selective; judicious use, RLP with imipenem can markedly increase treatment efficacy of severe distal limb infections in horses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Escherichia coli Overexpressing a Baeyer-Villiger Monooxygenase from Acinetobacter radioresistens Becomes Resistant to Imipenem. (United States)

    Minerdi, Daniela; Zgrablic, Ivan; Castrignanò, Silvia; Catucci, Gianluca; Medana, Claudio; Terlizzi, Maria Elena; Gribaudo, Giorgio; Gilardi, Gianfranco; Sadeghi, Sheila J


    Antimicrobial resistance is a global issue currently resulting in the deaths of hundreds of thousands of people a year worldwide. Data present in the literature illustrate the emergence of many bacterial species that display resistance to known antibiotics; Acinetobacter spp. are a good example of this. We report here that Acinetobacter radioresistens has a Baeyer-Villiger monooxygenase (Ar-BVMO) with 100% amino acid sequence identity to the ethionamide monooxygenase of multidrug-resistant (MDR) Acinetobacter baumannii. Both enzymes are only distantly phylogenetically related to other canonical bacterial BVMO proteins. Ar-BVMO not only is capable of oxidizing two anticancer drugs metabolized by human FMO3, danusertib and tozasertib, but also can oxidize other synthetic drugs, such as imipenem. The latter is a member of the carbapenems, a clinically important antibiotic family used in the treatment of MDR bacterial infections. Susceptibility tests performed by the Kirby-Bauer disk diffusion method demonstrate that imipenem-sensitive Escherichia coli BL21 cells overexpressing Ar-BVMO become resistant to this antibiotic. An agar disk diffusion assay proved that when imipenem reacts with Ar-BVMO, it loses its antibiotic property. Moreover, an NADPH consumption assay with the purified Ar-BVMO demonstrates that this antibiotic is indeed a substrate, and its product is identified by liquid chromatography-mass spectrometry to be a Baeyer-Villiger (BV) oxidation product of the carbonyl moiety of the β-lactam ring. This is the first report of an antibiotic-inactivating BVMO enzyme that, while mediating its usual BV oxidation, also operates by an unprecedented mechanism of carbapenem resistance. Copyright © 2015, American Society for Microbiology. All Rights Reserved.



    Gloria Narjara Santos da Silva; Patricia Pozzatti; Fabiane Rigatti; Rosmari Hörner; Sydney Hartz Alves; Carlos Augusto Mallmann; Berta Maria Heinzmann


    α-Curcumene was isolated from the fresh aerial parts of Senecio selloi Spreng. DC. and its activity against bacteria, yeasts and an alga was inspected by the applying the microdilution method. The strongest effect was manifested against Saccharomyces cerevisiae with estimated values of MIC and MFC 0.8 mg/mL. The α-curcumene synergism in the concentrations of 1 mM and 5 mM, respectively, with selected antibiotics (ciprofloxacin, imipenem, ceftazidim and a combination of amoxicillin and clavula...

  8. Imipenem/cilastatin vs. gentamicin/clindamycin for the treatment of moderate to severe infections in hospitalized patients. (United States)

    Guerra, J G; Casalino, E; Palomino, J C; Barboza, E; del Castillo, M; Gonzalez del Riego, M; Huapaya, V; Antúnez de Mayolo, E


    Imipenem/cilastatin was compared with the combination of gentamicin plus clindamycin in terms of efficacy and safety for the treatment of moderate to severe infections in an open, randomized study. The rates of cure achieved with the two regimens were similar. Gentamicin/clindamycin treatment failed only in two of four instances of severe infection. Patients given imipenem/cilastatin seemed to respond more rapidly to treatment; this observation applied both to the entire group treated and to the subgroup with moderate intraabdominal infections. Susceptible etiologic agents were more frequently eradicated by imipenem/cilastatin (95%) than by gentamicin/clindamycin (79%). The most common adverse reactions were nausea or vomiting in patients given imipenem/cilastatin and urinary abnormalities in those given gentamicin/clindamycin. Self-limited diarrhea was observed with equal frequency in the two groups. No adverse reactions required the discontinuation of treatment. Colonization or superinfection with resistant organisms and Pseudomonas aeruginosa occurred significantly more often among patients given gentamicin/clindamycin. These results suggest that imipenem/cilastatin is a promising alternative to the combination of gentamicin and clindamycin for the treatment of moderate to severe infections in hospitalized patients.

  9. Risk factors and outcomes of imipenem-resistant Acinetobacter bloodstream infection in North-eastern Malaysia (United States)

    Deris, Zakuan Zainy; Shafei, Mohd Nazri; Harun, Azian


    Objective To determine the risk factors and outcomes of imipenem-resistant Acinetobacter baumannii (IRAB) bloodstream infection (BSI) cases, since there is very little publication on Acinetobacter baumannii infections from Malaysia. Methods A cross sectional study of 41 cases (73.2%) of imipenem-sensitive Acinetobacter baumanii (ISAB) and 15 cases (26.8%) of IRAB was conducted in a teaching hospital which was located at North-Eastern state of Malaysia. Results There was no independent risk factor for IRAB BSI identified but IRAB BSI was significantly associated with longer bacteraemic days [OR 1.23 (95% CI 1.01, 1.50)]. Although prior use of carbepenems and cephalosporin were higher among IRAB than ISAB group, statistically they were not significant. There was no significant difference in term of outcomes between the two groups. Conclusions Although statistically not significant, this analysis compliments previous publication highlighting the importance of appropriate empiric antibiotic usage in hospital especially carbepenems and need further evaluation with bigger subjects. PMID:23569782

  10. Pseudomonas aeruginosa biofilms exposed to imipenem exhibit changes in global gene expression and beta-lactamase and alginate production

    DEFF Research Database (Denmark)

    Bagge, Niels; Schuster, Martin; Hentzer, Morten


    . As expected, the most strongly induced gene was ampC, which codes for chromosomal beta-lactamase. We also found that genes coding for alginate biosynthesis were induced by exposure to imipenem. Alginate production is correlated to the development of impaired lung function, and P. aeruginosa strains isolated...... from chronically colonized lungs of CF patients are nearly always mucoid due to the overproduction of alginate. Exposure to subinhibitory concentrations of imipenem caused structural changes in the biofilm, e.g., an increased biofilm volume. Increased levels of alginate production may be an unintended...

  11. Pharmacokinetic-pharmacodynamic correlation of imipenem in pediatric burn patients using a bioanalytical liquid chromatographic method

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    Silvia Regina Cavani Jorge Santos


    Full Text Available A bioanalytical method was developed and applied to quantify the free imipenem concentrations for pharmacokinetics and PK/PD correlation studies of the dose adjustments required to maintain antimicrobial effectiveness in pediatric burn patients. A reverse-phase Supelcosil LC18 column (250 x 4.6 mm 5 micra, binary mobile phase consisting of 0.01 M, pH 7.0 phosphate buffer and acetonitrile (99:1, v/v, flow rate of 0.8 mL/min, was applied. The method showed good absolute recovery (above 90%, good linearity (0.25-100.0 µg/mL, r2=0.999, good sensitivity (LLOQ: 0.25 µg/mL; LLOD: 0.12 µg/mL and acceptable stability. Inter/intraday precision values were 7.3/5.9%, and mean accuracy was 92.9%. A bioanalytical method was applied to quantify free drug concentrations in children with burns. Six pediatric burn patients (median 7.0 years old, 27.5 kg, normal renal function, and 33% total burn surface area were prospectively investigated; inhalation injuries were present in 4/6 (67% of the patients. Plasma monitoring and PK assessments were performed using a serial blood sample collection for each set, totaling 10 sets. The PK/PD target attained (40%T>MIC for each minimum inhibitory concentration (MIC: 0.5, 1.0, 2.0, 4.0 mg/L occurred at a percentage higher than 80% of the sets investigated and 100% after dose adjustment. In conclusion, the purification of plasma samples using an ultrafiltration technique followed by quantification of imipenem plasma measurements using the LC method is quite simple, useful, and requires small volumes for blood sampling. In addition, a small amount of plasma (0.25 mL is needed to guarantee drug effectiveness in pediatric burn patients. There is also a low risk of neurotoxicity, which is important because pharmacokinetics are unpredictable in these critical patients with severe hospital infection. Finally, the PK/PD target was attained for imipenem in the control of sepsis in pediatric patients with burns.

  12. Imipenem in burn patients: pharmacokinetic profile and PK/PD target attainment. (United States)

    Gomez, David S; Sanches-Giraud, Cristina; Silva, Carlindo V; Oliveira, Amanda M Ribas Rosa; da Silva, Joao Manoel; Gemperli, Rolf; Santos, Silvia R C J


    Unpredictable pharmacokinetics (PK) in burn patients may result in plasma concentrations below concentrations that are effective against common pathogens. The present study evaluated the imipenem PK profile and pharmacokinetic/pharmacodynamics (PK/PD) correlation in burn patients. Fifty-one burn patients, 38.7 years of age (mean), 68.0 kg, 36.3% total burn surface area (TBSA), of whom 84% (43/51) exhibited thermal injury, 63% inhalation injury and 16% electrical injury (8/51), all of whom were receiving imipenem treatment were investigated. Drug plasma monitoring, PK study (120 sets of plasma levels) and PK/PD correlation were performed in a series of blood samples. Only 250 μl of plasma samples were required for drug plasma measurements using the ultra filtration technique for the purification of biological matrix and quantification using liquid chromatography. Probability of target attainment (PTA) was calculated using a PD target of 40% free drug concentrations above the minimum inhibitory concentration (40%fT>MIC). Significant differences in PK parameters (medians), such as biological half-life (2.2 vs 5.5 h), plasma clearance (16.2 vs 1.4 l h(-1)) and volume of distribution (0.86 vs 0.19 l kg(-1)), were registered in burn patients via comparisons of set periods with normal renal function against periods of renal failure. Correlations between creatinine clearance and total body plasma clearance were also obtained. In addition, the PK profile did not change according to TBSA during sets when renal function was preserved. PTA was >89% for MIC values up to 4 mg l(-1). In conclusion, imipenem efficacy for the control of hospital infection on the basis of PK/PD correlation was guaranteed for burn in patients at the recommended dose regimens for normal renal function (31.1±9.7 mg kg(-1) daily), but the daily dose must be reduced to 17.2±9.7 mg kg(-1) during renal failure to avoid neurotoxicity.

  13. A Prospective Randomized Trial of Imipenem-Cilastatin Versus Clindamycin/Tobramycin in the Treatmentof Intra-Abdominal and Pelvic Infections

    Directory of Open Access Journals (Sweden)

    Lionel A Mandell


    Full Text Available Objective: A Canadian multicentre clinical trial in the treatment of intra-abdominal and pelvic infections to compare the efficacy and safety of monotherapy using imipenem-cilastatin (imipenem (500 mg intravenously every 6 h versus combination therapy with clindamycin/tobramycin (clindamycin 600 mg intravenously every 6 h and tobramycin 1.7 mg/kg intravenously every 8 h.

  14. Pseudomonas aeruginosa biofilms exposed to imipenem exhibit changes in global gene expression and beta-lactamase and alginate production

    DEFF Research Database (Denmark)

    Bagge, N.; Schuster, M.; Hentzer, Morten


    . The treatment often includes beta-lactam antibiotics. How these antibiotics influence gene expression in the surviving biofilm population of P. aeruginosa is not clear. Thus, we used the microarray technology to study the effects of subinhibitory concentrations of a beta-lactam antibiotic, imipenem, on gene...

  15. Molecular analysis of imipenem-resistant Acinetobacter baumannii isolated from US service members wounded in Iraq, 2003–2008 (United States)

    Clonal spread and global dissemination of imipenem resistant (IR) A. baumannii-A. calcoaceticus complex (ABC) have been reported in recent years. However, the epidemiological features of the IR-ABCs in military treatment facilities (MTFs) have not been systematically studied. In this study, 298 ABC...

  16. [Effect of continuous renal replacement therapy on the plasma concentration of imipenem in severe infection patients with acute renal injury]. (United States)

    Yu, Bin; Liu, Lixia; Xing, Dong; Zhao, Congcong; Hu, Zhenjie


    To investigate the extracorporeal clearance rate of imipenem in severe infection patients in the mode of continuous vena-venous hemofiltration (CVVH) during continuous renal replacement therapy (CRRT), in order to approach if the concentration of imipenem in plasma could achieve effective levels of anti-infection, and to explore the effect of time and anticoagulation measure on imipenem clearance during CRRT treatment. A prospective observational study was conducted. All adult severe infection patients complicating acute kidney injury (AKI) in the Department of Critical Care Medicine of the Fourth Hospital of Hebei Medical University from March 2013 to September 2014, who were prescribed imipenem as part of their required medical care, and CRRT for treatment of AKI were enrolled. 0.5 g doses of imipenem was administered intravenously every 6 hours or 8 hours according to random number table, and infused over 0.5 hour. The unfractionated heparin was used for anticoagulation in the patients without contraindications, and no anticoagulation strategy was used in the patients with high risk of bleeding. At 24 hours after first time of administration, postfilter venous blood and ultrafiltrate samples were collected at 0, 0.25, 0.5, 0.75, 1, 2, 5, 6, and 8 hours after imipenem administration. The concentration of imipenem in above samples was determined with liquid chromatography-mass spectrometer/mass spectrometer (LC-MS/MS). A total of 25 patients were enrolled. Thirteen patients received imipenem intravenously every 6 hours, and 12 patients, every 8 hours. The anticoagulation was conducted with heparin in 13 cases, and 12 cases without anticoagulation. The intra-day precision, inter-day precision, matrix effect, and recovery rate in low, medium, and high concentration of plasma and ultrafiltrate, and the stability of samples under different conditions showed a good result, the error of accuracy was controlled in the range of ±15%. With the application of Prismaflex

  17. [A case-control study on the risk factors of nosocomial infection caused by imipenem-resistant Pseudomonas aeruginosa]. (United States)

    Peng, Shao-hua; Jin, Zheng-jiang; Luo, Lan; Li, Cong-rong


    To explore the risk factors for nosocomial infection caused by imipenem-resistant Pseudomonas aeruginosa (IRPA). A case-control study was carried out for the comparison of 2 groups of 'case' patients with 'controlled' patients. The first group of 'case' patients had nosocomial isolation of IRPA, and the second group had imipenem-susceptible Pseudomonas aeruginosa (ISPA). 'Control' patients were selected from the same medical or surgical services from which 'case' patients were receiving care when isolation of IRPA or ISPA occurred. Risk factors analyzed included the use of antimicrobials, comorbid conditions, and demographic variables. IRPA was recovered from 67 patients, and ISPA from 150 patients while the control case were 200 and 159 respectively. All patients were from Renmin Hospital of Wuhan University during Jan 2002 to Dec 2003. Data were analyzed with unconditional logistic regression and principal component analysis. Data from multivariate unconditional logistic regression analysis showed that the independent risk factors for IRPA nosocomial infection were: time at risk (OR = 1.03, 95% CI: 1.01-1.04), imipenem (OR = 4.65, 95% CI: 1.35-11.52), PIP/TAZ (OR = 3.37, 95% CI 1.85-9.43) and quinolones (OR = 1.85, 95% CI: 1.25-5.34) while the third cephalosporins (OR = 2.54, 95% CI: 1.26-5.23) and aminoglycoside antibiotics (OR = 1.86, 95% CI 1.42-3.26) time at risk (OR = 1.05, 95% CI: 1.03-1.05) were associated with isolated ISPA. Nosocomial infection of IRPA could be caused by the use of imipenem and other antibiotics, suggesting that to limit the use of imipenem was not sufficient to contain the increasing incidence of IRPA.

  18. Phase 2, Dose-Ranging Study of Relebactam with Imipenem-Cilastatin in Subjects with Complicated Intra-abdominal Infection. (United States)

    Lucasti, Christopher; Vasile, Liviu; Sandesc, Dorel; Venskutonis, Donatas; McLeroth, Patrick; Lala, Mallika; Rizk, Matthew L; Brown, Michelle L; Losada, Maria C; Pedley, Alison; Kartsonis, Nicholas A; Paschke, Amanda


    Relebactam (REL [MK-7655]) is a novel class A/C β-lactamase inhibitor intended for use with imipenem for the treatment of Gram-negative bacterial infections. REL restores imipenem activity against some resistant strains of Klebsiella and Pseudomonas In this multicenter, double-blind, controlled trial (NCT01506271), subjects who were ≥18 years of age with complicated intra-abdominal infection were randomly assigned (1:1:1) to receive 250 mg REL, 125 mg REL, or placebo, each given intravenously (i.v.) with 500 mg imipenem-cilastatin (IMI) every 6 h (q6h) for 4 to 14 days. The primary efficacy endpoint was the proportion of microbiologically evaluable (ME) subjects with a favorable clinical response at discontinuation of i.v. therapy (DCIV). A total of 351 subjects were randomized, 347 (99%) were treated, and 255 (73%) were ME at DCIV (55% male; mean age, 49 years). The most common diagnoses were complicated appendicitis (53%) and complicated cholecystitis (17%). Thirty-six subjects (13%) had imipenem-resistant Gram-negative infections at baseline. Both REL doses plus IMI were generally well tolerated and demonstrated safety profiles similar to that of IMI alone. Clinical response rates at DCIV were similar in subjects who received 250 mg REL plus IMI (96.3%) or 125 mg REL plus IMI (98.8%), and both were noninferior to IMI alone (95.2%; one-sided P 90% of carbapenem-resistant bacterial strains. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  19. Inhibition of the β-Lactamase BlaMab by Avibactam Improves the In Vitro and In Vivo Efficacy of Imipenem against Mycobacterium abscessus. (United States)

    Lefebvre, Anne-Laure; Le Moigne, Vincent; Bernut, Audrey; Veckerlé, Carole; Compain, Fabrice; Herrmann, Jean-Louis; Kremer, Laurent; Arthur, Michel; Mainardi, Jean-Luc


    Mycobacterium abscessus pulmonary infections are treated with a macrolide (clarithromycin or azithromycin), an aminoglycoside (amikacin), and a β-lactam (cefoxitin or imipenem). The triple combination is used without any β-lactamase inhibitor, even though Mabscessus produces the broad-spectrum β-lactamase BlaMab We determine whether inhibition of BlaMab by avibactam improves the activity of imipenem against M. abscessus The bactericidal activity of drug combinations was assayed in broth and in human macrophages. The in vivo efficacy of the drugs was tested by monitoring the survival of infected zebrafish embryos. The level of BlaMab production in broth and in macrophages was compared by quantitative reverse transcription-PCR and Western blotting. The triple combination of imipenem (8 or 32 μg/ml), amikacin (32 μg/ml), and avibactam (4 μg/ml) was bactericidal in broth (<0.1% survival), with 3.2- and 4.3-log10 reductions in the number of CFU being achieved at 72 h when imipenem was used at 8 and 32 μg/ml, respectively. The triple combination achieved significant intracellular killing, with the bacterial survival rates being 54% and 7% with the low (8 μg/ml) and high (32 μg/ml) dosages of imipenem, respectively. In vivo inhibition of BlaMab by avibactam improved the survival of zebrafish embryos treated with imipenem. Expression of the gene encoding BlaMab was induced (20-fold) in the infected macrophages. Inhibition of BlaMab by avibactam improved the efficacy of imipenem against M. abscessusin vitro, in macrophages, and in zebrafish embryos, indicating that this β-lactamase inhibitor should be clinically evaluated. The in vitro evaluation of imipenem may underestimate the impact of BlaMab, since the production of the β-lactamase is inducible in macrophages. Copyright © 2017 American Society for Microbiology.

  20. In vitro activities of amoxicillin-clavulanate, doxycycline, ceftazidime, imipenem, and trimethoprim-sulfamethoxazole against biofilm of Brazilian strains of Burkholderia pseudomallei. (United States)

    Bandeira, Tereza de Jesus Pinheiro Gomes; Moreira, Camila Alencar; Brilhante, Raimunda Sâmia Nogueira; Castelo-Branco, Débora de Souza Collares Maia; Neto, Manoel Paiva de Araújo; Cordeiro, Rossana de Aguiar; Rodrigues, Terezinha de Jesus Santos; Rocha, Marcos Fábio Gadelha; Sidrim, José Júlio Costa


    This study aimed at investigating the in vitro activities of amoxicillin-clavulanate, doxycycline, ceftazidime, imipenem, and trimethoprim-sulfamethoxazole against Burkholderia pseudomallei in planktonic and biofilm forms, through broth microdilution and resazurin-based viability staining, respectively. In planktonic growth, the strains were susceptible to the drugs, while in biofilm growth, significantly higher antimicrobial concentrations were required, especially for ceftazidime and imipenem, surpassing the resistance breakpoints. These results highlight the importance of the routine evaluation of biofilm antimicrobial susceptibility.

  1. No Development of Imipenem Resistance in Pneumonia Caused by Escherichia coli (United States)

    Yayan, Josef; Ghebremedhin, Beniam; Rasche, Kurt


    Background: Antibiotic resistance continues to rise due to the increased number of antibiotic prescriptions and is now a major threat to public health. In particular, there is an increase in antibiotic resistance to Escherichia coli according to the latest reports. Trial Design: This article examines, retrospectively, antibiotic resistance in patients with community- and nosocomial-acquired pneumonia caused by E coli. Methods: The data of all patients with community- and nosocomial-acquired pneumonia caused by E coli were collected from the hospital charts at the HELIOS Clinic, Witten/Herdecke University, Wuppertal, Germany, within the study period 2004 to 2014. An antibiogram was performed for the study patients with pneumonia caused by E coli. Antimicrobial susceptibility testing was performed for the different antibiotics that have been consistently used in the treatment of patients with pneumonia caused by E coli. All demographic, clinical, and laboratory data of all of the patients with pneumonia caused by E coli were collected from the patients’ records. Results: During the study period of January 1, 2004 to August 12, 2014, 135 patients were identified with community- and nosocomial-acquired pneumonia affected by E coli. These patients had a mean age of 72.5 ± 11.6 (92 [68.1%, 95% CI 60.2%–76.0%] males and 43 [31.9%, 95% CI 24.0%–39.8%] females). E coli had a high resistance rate to ampicillin (60.7%), piperacillin (56.3%), ampicillin–sulbactam (44.4%), and co-trimoxazole (25.9%). No patients with pneumonia caused by E coli showed resistance to imipenem (P pneumonia caused by E coli. PMID:26107669

  2. Photochemical degradation of the carbapenem antibiotics imipenem and meropenem in aqueous solutions under solar radiation. (United States)

    Reina, Alejandro Cabrera; Martínez-Piernas, Ana B; Bertakis, Yannis; Brebou, Christina; Xekoukoulotakis, Nikolaos P; Agüera, Ana; Sánchez Pérez, José Antonio


    This paper deals with the photochemical fate of two representative carbapenem antibiotics, namely imipenem and meropenem, in aqueous solutions under solar radiation. The analytical method employed for the determination of the target compounds in various aqueous matrices, such as ultrapure water, municipal wastewater treatment plant effluents, and river water, at environmentally relevant concentrations, was liquid chromatography coupled with hybrid triple quadrupole-linear ion trap-mass spectrometry. The absorption spectra of both compounds were measured in aqueous solutions at pH values from 6 to 8, and both compounds showed a rather strong absorption band centered at about 300 nm, while their molar absorption coefficient was in the order from 9 × 10 3 -10 4  L mol -1  cm -1 . The kinetics of the photochemical degradation of the target compounds was studied in aqueous solutions under natural solar radiation in a solar reactor with compound parabolic collectors. It was found that the photochemical degradation of both compounds at environmentally relevant concentrations follows first order kinetics and the quantum yield was in the order of 10 -3  mol einsten -1 . Several parameters were studied, such as solution pH, the presence of nitrate ions and humic acids, and the effect of water matrix. In all cases, it was found that the presence of various organic and inorganic constituents in the aqueous matrices do not contribute significantly, either positively or negatively, to the photochemical degradation of both compounds under natural solar radiation. In a final set of photolysis experiments, the effect of the level of irradiance was studied under simulated solar radiation and it was found that the quantum yield for the direct photodegradation of both compounds remained practically constant by changing the incident solar irradiance from 28 to 50 W m -2 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Multidrug resistant Acinetobacter baumannii: risk factors for appearance of imipenem resistant strains on patients formerly with susceptible strains.

    Directory of Open Access Journals (Sweden)

    Jung-Jr Ye

    Full Text Available BACKGROUND: Multidrug resistant Acinetobacter baumannii (MDRAB is an important nosocomial pathogen usually susceptible to carbapenems; however, growing number of imipenem resistant MDRAB (IR-MDRAB poses further clinical challenge. The study was designed to identify the risk factors for appearance of IR-MDRAB on patients formerly with imipenem susceptible MDRAB (IS-MDRAB and the impact on clinical outcomes. METHODOLOGY/PRINCIPAL FINDINGS: A retrospective case control study was carried out for 209 consecutive episodes of IS-MDRAB infection or colonization from August 2001 to March 2005. Forty-nine (23.4% episodes with succeeding clinical isolates of IR-MDRAB were defined as the cases and 160 (76.6% with all subsequent clinical isolates of IS-MDRAB were defined as the controls. Quantified antimicrobial selective pressure, "time at risk", severity of illness, comorbidity, and demographic data were incorporated for multivariate analysis, which revealed imipenem or meropenem as the only significant independent risk factor for the appearance of IR-MDRAB (adjusted OR, 1.18; 95% CI, 1.09 to 1.27. With selected cases and controls matched to exclude exogenous source of IR-MDRAB, multivariate analysis still identified carbapenem as the only independent risk factor (adjusted OR, 1.48; 95% CI, 1.14 to 1.92. Case patients had a higher crude mortality rate compared to control patients (57.1% vs. 31.3%, p = 0.001, and the mortality of case patients was associated with shorter duration of "time at risk", i.e., faster appearance of IR-MDRAB (adjusted OR, 0.9; 95% CI, 0.83 to 0.98. CONCLUSIONS/SIGNIFICANCE: Judicious use of carbapenem with deployment of antibiotics stewardship measures is critical for reducing IR-MDRAB and the associated unfavorable outcome.

  4. Pharmacokinetics of Imipenem/Cilastatin Burn Intensive Care Unit Patients Undergoing High-Dose Continuous Venovenous Hemofiltration. (United States)

    Boucher, Bradley A; Hudson, Joanna Q; Hill, David M; Swanson, Joseph M; Wood, G Christopher; Laizure, S Casey; Arnold-Ross, Angela; Hu, Zhe-Yi; Hickerson, William L


    High-dose continuous venovenous hemofiltration (CVVH) is a continuous renal replacement therapy (CRRT) used frequently in patients with burns. However, antibiotic dosing is based on inference from studies assessing substantially different methods of CRRT. To address this knowledge gap for imipenem/cilastatin (I/C), we evaluated the systemic and extracorporeal clearances (CLs) of I/C in patients with burns undergoing high-dose CVVH. Prospective clinical pharmacokinetic study. Ten adult patients with burns receiving I/C for a documented infection and requiring high-dose CVVH were studied. Blood and effluent samples for analysis of I/C concentrations were collected for up to 6 hours after the I/C infusion for calculation of I/C total CL (CLTotal ), CL by CVVH (CLHF ), half-life during CVVH, volume of distribution at steady state (Vdss ), and the percentage of drug eliminated by CVVH. In this patient sample, the mean age was 50 ± 17 years, total body surface area burns was 23 ± 27%, and 80% were male. Nine patients were treated with high-dose CVVH for acute kidney injury and one patient for sepsis. The mean delivered CVVH dose was 52 ± 14 ml/kg/hour (range 32-74 ml/kg/hr). The imipenem CLHF was 3.27 ± 0.48 L/hour, which accounted for 23 ± 4% of the CLTotal (14.74 ± 4.75 L/hr). Cilastatin CLHF was 1.98 ± 0.56 L/hour, which accounted for 45 ± 19% of the CLTotal (5.16 + 2.44 L/hr). The imipenem and cilastatin half-lives were 1.77 ± 0.38 hours and 4.21 ± 2.31 hours, respectively. Imipenem and cilastatin Vdss were 35.1 ± 10.3 and 32.8 ± 13.8 L, respectively. Efficient removal of I/C by high-dose CVVH, a high overall clearance, and a high volume of distribution in burn intensive care unit patients undergoing this CRRT method warrant aggressive dosing to treat serious infections effectively depending on the infection site and/or pathogen. © 2016 Pharmacotherapy Publications, Inc.

  5. Activity of imipenem, third-generation cephalosporins, aztreonam and ciprofloxacin against multi-resistant gram-negative bacilli isolated from Chilean hospitals. (United States)

    Zemelman, R; Bello, H; Dominguez, M; Gonzalez, G; Mella, S; Garcia, A


    The activity of imipenem against nosocomial strains of Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter spp. and methicillin-resistant Staphylococcus aureus resistant to some third-generation cephalosporins, aztreonam, or ciprofloxacin was assessed. These strains represent the most prevalent multi-resistant nosocomial microorganisms in Chile since they were isolated from clinical specimens in 11 Chilean hospitals. A high proportion of the strains were resistant to several beta-lactams, yet all strains of K. pneumoniae and Acinetobacter spp. were susceptible to imipenem; resistance was exhibited by only one strain of P. aeruginosa and 16 strains of S. aureus. Synergy between cefotaxime and clavulanic acid was found in almost all strains of K. pneumoniae, suggesting the presence of plasmid-coded beta-lactamases, probably with extended-spectrum activity. Killing A. baumannii by imipenem was rapid, but slower for P. aeruginosa. Killing of K. pneumoniae was also somewhat slower despite the lower MIC of imipenem for this strain. Bactericidal activity was even slower against one strain of methicillin-resistant S. aureus. These results suggest that imipenem would be an adequate alternative to other broad-spectrum agents in the treatment of infections due to nosocomial multi-resistant Gram-negative bacilli.

  6. Emergence in Taiwan of novel imipenem-resistant Acinetobacter baumannii ST455 causing bloodstream infection in critical patients. (United States)

    Lee, Hao-Yuan; Huang, Chih-Wei; Chen, Chyi-Liang; Wang, Yi-Hsin; Chang, Chee-Jen; Chiu, Cheng-Hsun


    Acinetobacter baumannii is one of the most important nosocomial pathogens worldwide. This study aimed to use multilocus sequence typing (MLST) for the epidemiological surveillance of A. baumannii isolates in Taiwan and analyze the clinical presentations and patients' outcome. MLST according to both Bartual's PubMLST and Pasteur's MLST schemes was applied to characterize bloodstream imipenem-resistant A. baumannii (IRAB) infection in intensive care units in a medical center. A total of 39 clinical IRAB bloodstream isolates in 2010 were enrolled. We also collected 13 imipenem-susceptible A. baumannii (ISAB) bloodstream isolates and 30 clinical sputum isolates (24 IRAB and 6 ISAB) for comparison. Clinical presentations and outcome of the patients were analyzed. We found that infection by ST455(B)/ST2(P) and inappropriate initial therapy were statistically significant risk factors for mortality. More than one-third of the IRAB isolates belonged to ST455(B)/ST2(P). Most ST455(B)/ST2(P) (80%) carried ISAba1-blaOXA-23, including 10 (66.7%) with Tn2006 (ISAba1-blaOXA-23-ISAba1) in an AbaR4-type resistance island. ST455(B)/ST2(P) appears to evolve from ST208(B)/ST2(P) of clonal complex (CC) 92(B)/CC2(P). In this hospital-based study, A. baumannii ST455 accounted for 38.5% of IRAB bacteremia, with a high mortality of 86.7%. Approximately 85% of ST455(B)/ST2(P)bacteremia had a primary source of ventilation-associated pneumonia. We report the emergence in Taiwan of IRAB ST455(B)/ST2(P), which is the current predominant clone of IRAB in our hospital and has been causing bacteremia with high mortality in critical patients. Copyright © 2015. Published by Elsevier B.V.

  7. Pharmacodynamic profiling of doripenem, imipenem and meropenem against prevalent Gram-negative organisms in the Asia-Pacific region. (United States)

    Kiratisin, Pattarachai; Keel, Rebecca A; Nicolau, David P


    Carbapenems are increasingly being utilised owing to the escalating prevalence of antimicrobial-resistant Gram-negative bacteria from community and hospital settings. In this study, pharmacodynamic profiles of doripenem, imipenem and meropenem were evaluated against Gram-negative bacteria isolated from hospitalised patients. MICs for carbapenems were determined for Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii obtained from the COMPACT II programme conducted in the Asia-Pacific region. Monte Carlo simulations were undertaken to assess the pharmacodynamic profile of carbapenems against each of the pathogens. All carbapenem regimens achieved optimal exposures [cumulative fraction of response (CFR) ≥90%] against E. coli and K. pneumoniae. Against P. aeruginosa, doripenem achieved 81.3-95.3% CFR, imipenem achieved 55.2-77.9% CFR and meropenem achieved 71.9-91.3% CFR; only doripenem regimens of 4-h infusion of 1000 mg every 8h (q8h) and 1-h and 4-h infusion of 2000 mg q8h and a meropenem regimen of 3-h infusion of 2000 mg q8h obtained optimal exposures; all carbapenem regimens showed slight (1-7%) improvement in CFRs in favour of isolates collected from ICU sources. Against A. baumannii, CFRs were much lower (25.9-46.7% CFR) and no carbapenem regimens achieved optimal exposure in or outside the ICU. Owing to the high potency of carbapenems against these Enterobacteriaceae populations, standard regimens are likely to perform well in the Asia-Pacific region. However, larger doses combined with prolonged infusions will be required to increase the CFR for these carbapenems against resistant non-fermenting Gram-negatives such as P. aeruginosa and A. baumannii that are prevalent in these countries. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  8. In Vitro Activity of Imipenem and Colistin against a Carbapenem-Resistant Klebsiella pneumoniae Isolate Coproducing SHV-31, CMY-2, and DHA-1

    Directory of Open Access Journals (Sweden)

    Hung-Jen Tang


    Full Text Available We investigated the synergism of colistin and imipenem against a multidrug-resistant K. pneumoniae isolate which was recovered from a severe hip infection. PCR and DNA sequencing were used to characterize the outer membrane porin genes and the resistance genes mediating the common β-lactamases and carbapenemases. Synergism was evaluated by time-kill studies. The blaSHV-31, blaCMY-2, and blaDHA-1 were detected. Outer membrane porin genes analysis revealed loss of ompK36 and frame-shift mutation of ompK35. The common carbapenemase genes were not found. Time-kill studies demonstrated that a combination of 1x MIC of colistin (2 mg/L and 1x MIC of imipenem (8 mg/L was synergistic and bactericidal but with inoculum effect. Bactericidal activity without inoculum effect was observed by concentration of 2x MIC of colistin alone or plus 2x MIC of imipenem. In conclusion, colistin plus imipenem could be an alternative option to treat carbapenem-resistant K. pneumoniae infections.

  9. In Vitro Comparison of Ertapenem, Meropenem, and Imipenem against Isolates of Rapidly Growing Mycobacteria and Nocardia by Use of Broth Microdilution and Etest. (United States)

    Brown-Elliott, Barbara A; Killingley, Jessica; Vasireddy, Sruthi; Bridge, Linda; Wallace, Richard J


    We compared the activities of the carbapenems ertapenem, meropenem, and imipenem against 180 isolates of rapidly growing mycobacteria (RGM) and 170 isolates of Nocardia using the Clinical and Laboratory Standards Institute (CLSI) guidelines. A subset of isolates was tested using the Etest. The rate of susceptibility to ertapenem and meropenem was limited and less than that to imipenem for the RGM. Analysis of major and minor discrepancies revealed that >90% of the isolates of Nocardia had higher MICs by the broth microdilution method than by Etest, in contrast to the lower broth microdilution MICs seen for >80% of the RGM. Imipenem remains the most active carbapenem against RGM, including Mycobacterium abscessus subsp. abscessus For Nocardia, imipenem was significantly more active only against Nocardia farcinica Although there may be utility in testing the activities of the newer carbapenems against Nocardia, their activities against the RGM should not be routinely tested. Testing by Etest is not recommended by the CLSI. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  10. Clinically Relevant Plasma Concentrations of Colistin in Combination with Imipenem Enhance Pharmacodynamic Activity against Multidrug-Resistant Pseudomonas aeruginosa at Multiple Inocula▿† (United States)

    Bergen, Phillip J.; Forrest, Alan; Bulitta, Jürgen B.; Tsuji, Brian T.; Sidjabat, Hanna E.; Paterson, David L.; Li, Jian; Nation, Roger L.


    The use of combination antibiotic therapy may be beneficial against rapidly emerging resistance in Pseudomonas aeruginosa. The aim of this study was to systematically investigate in vitro bacterial killing and resistance emergence with colistin alone and in combination with imipenem against multidrug-resistant (MDR) P. aeruginosa. Time-kill studies were conducted over 48 h using 5 clinical isolates and ATCC 27853 at two inocula (∼106 and ∼108 CFU/ml); MDR, non-MDR, and colistin-heteroresistant and -resistant strains were included. Nine colistin-imipenem combinations were investigated. Microbiological response was examined by log changes at 6, 24, and 48 h. Colistin combined with imipenem at clinically relevant concentrations increased the levels of killing of MDR and colistin-heteroresistant isolates at both inocula. Substantial improvements in activity with combinations were observed across 48 h with all colistin concentrations at the low inoculum and with colistin at 4× and 16× MIC (or 4 and 32 mg/liter) at the high inoculum. Combinations were additive or synergistic against imipenem-resistant isolates (MICs, 16 and 32 mg/liter) at the 106-CFU inoculum in 9, 11, and 12 of 18 cases (i.e., 9 combinations across 2 isolates) at 6, 24, and 48 h, respectively, and against the same isolates at the 108-CFU inoculum in 11, 7, and 8 cases, respectively. Against a colistin-resistant strain (MIC, 128 mg/liter), combinations were additive or synergistic in 9 and 8 of 9 cases at 24 h at the 106- and 108-CFU inocula, respectively, and in 5 and 7 cases at 48 h. This systematic study provides important information for optimization of colistin-imipenem combinations targeting both colistin-susceptible and colistin-resistant subpopulations. PMID:21876058

  11. Effectiveness of the antimicrobial removal device, BACTEC 16B medium, and thiol broth in neutralizing antibacterial activities of imipenem, norfloxacin, and related agents. (United States)

    Weinberg, E; Shungu, D L; Gadebusch, H H


    The Antimicrobial Removal Device (ARD), BACTEC 16B medium, and Thiol broth were evaluated for their effectiveness in reducing the activity of imipenem (IPM), cefoxitin, moxalactam, and ceftazidime in blood samples. In addition, the capability of the ARD and Thiol broth to bind norfloxacin and the ARD to bind oxolinic and nalidixic acids in urine samples was investigated. At the highest concentrations of the drugs tested (32 micrograms/ml for the four beta-lactams and 256 micrograms/ml for the three quinolinecarboxylic acids), there was at least a 95% reduction in the in vitro activity of each of the antibacterial agents for treated versus untreated samples. Of the compounds tested in the ARD system, the organic acids were more completely removed than were the beta-lactams. The Thiol broth was more effective than the ARD and the BACTEC 16B medium in inactivating imipenem, but it had no effect on the antibacterial activity of norfloxacin.

  12. Effectiveness of the antimicrobial removal device, BACTEC 16B medium, and thiol broth in neutralizing antibacterial activities of imipenem, norfloxacin, and related agents.


    Weinberg, E.; Shungu, D L; Gadebusch, H. H.


    The Antimicrobial Removal Device (ARD), BACTEC 16B medium, and Thiol broth were evaluated for their effectiveness in reducing the activity of imipenem (IPM), cefoxitin, moxalactam, and ceftazidime in blood samples. In addition, the capability of the ARD and Thiol broth to bind norfloxacin and the ARD to bind oxolinic and nalidixic acids in urine samples was investigated. At the highest concentrations of the drugs tested (32 micrograms/ml for the four beta-lactams and 256 micrograms/ml for the...

  13. Identification and Characterization of Imipenem-Resistant Klebsiella pneumoniae and Susceptible Klebsiella variicola Isolates Obtained from the Same Patient. (United States)

    Garza-Ramos, Ulises; Moreno-Dominguez, Stephania; Hernández-Castro, Rigoberto; Silva-Sanchez, Jesús; Barrios, Humberto; Reyna-Flores, Fernando; Sanchez-Perez, Alejandro; Carrillo-Casas, Erika M; Sanchez-León, María Carmen; Moncada-Barron, David


    Klebsiella variicola, a bacterium closely genetically related to Klebsiella pneumoniae, is commonly misidentified as K. pneumoniae by biochemical tests. To distinguish between the two bacteria, phylogenetic analysis of the rpoB gene and the identification of unique genes in both bacterial species by multiplex-polymerase chain reaction (PCR) provide the means to reliably identify and genotype K. variicola. In recent years, K. variicola has been described both as the cause of an intrahospital outbreak in a pediatric hospital, which resulted in sepsis in inpatients, and as a frequent cause of bloodstream infections. In the present study, K. pneumoniae and K. variicola were isolated from a unique patient displaying different antimicrobial susceptibility phenotypes and different genotypes of virulence determinants. Eight clinical isolates were obtained at different time intervals; all during a 5-month period. The isolates were identified as K. pneumoniae by an automated identification system. The clinical (biochemical test) and molecular (multiplex-PCR and rpoB gene) characterization identified imipenem resistance in the first six K. pneumoniae ST258 isolates, which encode the SHV-12 cephalosporinase and KPC-3 carbapenemase genes. The two last remaining isolates corresponded to susceptible K. variicola. The bacterial species showed a specific profile of virulence-associated determinants, specifically the fimA, fimH, and ecpRAB fimbrial-encoding genes identified only in K. pneumoniae isolates. However, the entb (enterobactin), mrkD (fimbrial adhesin), uge (epimerase), ureA (urease), and wabG (transferase) genes were shared between both bacterial species. Recent studies attribute a higher mortality rate to K. variicola than to K. pneumonia. This work highlights the identification of K. pneumoniae and the closely related K. variicola isolated from the same patient. The value of distinguishing between these two bacterial species is in their clinical significance, their

  14. Imipenem and Cilastatin Injection (United States)

    ... as doripenem (Doribax), ertapenem (Invanz), or meropenem (Merrem); local anesthetics such as bupivacaine (Exparel, Marcaine, Sensorcaine), etidocaine (Duranest), lidocaine, mepivacaine (Carbocaine, Prolocaine), or prilocaine (Citanest); cephalosporins such ...

  15. In-vitro activity of polymyxin B in combination with imipenem, rifampicin and azithromycin versus multidrug resistant strains of Acinetobacter baumannii producing OXA-23 carbapenemases

    Directory of Open Access Journals (Sweden)

    Bean David C


    Full Text Available Abstract Background Acinetobacter baumannii has emerged as a major nosocomial pathogen worldwide. Many of the circulating strains exhibit multi-drug resistance remaining consistently susceptible only to polymyxins. In-vitro studies have reported that polymyxins combined with carbapenems, rifampicin or azithromycin are synergistic against these strains despite in-vitro resistance to these agents alone. The use of antimicrobial combinations have therefore been advocated for the treatment of severe A. baumannii infection in man. In order to determine whether such combinations are synergistic against the prevalent clones of multi-drug resistant A. baumannii causing infection in the UK, we performed synergy testing against representative isolates using two rapid Etest methods. Methods The activity of polymyxin in combination with imipenem, azithromycin or rifampicin was assessed against five strains of multi-drug resistant A. baumannii encoding OXA-23 carbapenemases. Synergy studies were performed by Etest-agar dilution and a combined Etest strip method. Synergy was defined as a FICI of ≤ 0.5. Results All strains were resistant to β-lactams, carbapenems, quinolones and aminoglycosides but susceptible to polymyxins. Marked synergy was not seen with polymyxin in combination with imipenem, rifampicin or azithromycin against any of the strains. Borderline synergy (FICI = 0.5 was seen against one strain belonging to OXA-23 clonal group 2, using the Etest-agar dilution method only. Conclusion In-vitro synergy with polymxyin in combination with imipenem, rifampicin or azithromycin is highly strain and method dependent. As reliable synergy could not be demonstrated against the prevalent UK multi-drug resistant strains, use of such combinations should not be used for empirical treatment of these infections in the UK. The optimal treatment for serious multi-drug A. baumannii infection and the role of combination therapy should be addressed in a prospective

  16. In vitro activity of ACH-702, a new isothiazoloquinolone, against Nocardia brasiliensis compared with econazole and the carbapenems imipenem and meropenem alone or in combination with clavulanic acid. (United States)

    Vera-Cabrera, Lucio; Campos-Rivera, Mayra Paola; Escalante-Fuentes, Wendy G; Pucci, Michael J; Ocampo-Candiani, Jorge; Welsh, Oliverio


    The in vitro activities of ACH-702 and other antimicrobials against 30 Nocardia brasiliensis isolates were tested. The MIC(50) (MIC for 50% of the strains tested) and MIC(90) values of ACH-702 were 0.125 and 0.5 microg/ml. The same values for econazole were 2 and 4 microg/ml. The MIC(50) and MIC(90) values of imipenem and meropenem were 64 and >64 microg/ml and 2 and 8 microg/ml, respectively; the addition of clavulanic acid to the carbapenems had no effect.

  17. Utility of the ceftazidime-imipenem antagonism test (CIAT to detect and confirm the presence of inducible AmpC beta-lactamases among enterobacteriaceae

    Directory of Open Access Journals (Sweden)

    Vlademir Vicente Cantarelli

    Full Text Available Detection of AmpC beta-lactamase production by enterobacteria has been problematic. Contrary to ESBLs, no specific guidelines are available for detection and confirmation of AmpC production by clinical relevant microorganisms. Moreover, some bacterial species may produce inducible AmpC beta-lactamases that can be easily overlooked by routine susceptibility tests. We reported here a new test based on the strong inducible effect of imipenem on AmpC genes and the consequent antagonism with ceftazidime. This test is very simple and proved to be helpful in detecting AmpC-inducible enzymes among several species of clinical isolates.

  18. Occurrence of Ambler Class B Metallo-β-Lactamase Gene in Imipenem-Resistant Pseudomonas Aeruginosa Strains Isolated from Clinical Samples

    Directory of Open Access Journals (Sweden)

    Zeynab Golshani


    Full Text Available Background: 5TMetallo-β-lactamase (MBLs can hydrolyze a broad spectrum of beta-lactams, including penicillins, cephalosporins, and carbapenems. Genes encoding these enzymes are located on the plasmid that can easily be transferred to other bacteria. The aim of this study was to isolate and identify the Pseudomonas aeruginosa strains encoding VIM1 gene, in clinical samples, using the PCR technique. Materials and Methods: During a 4 month period, 100 strains of Pseudomonas aeruginosa from clinical specimens were collected. Standard tests were performed to identify strains of Pseudomonas aeruginosa. Resistance to antibiotics was examined and then the PCR was used to detect VIM1gene. Results:In this study, the highest rates of resistance to antibiotics, amikacin and cefotaxime was observed (65% and 62%, the lowest resistance to antibiotics piperacillin (48% and imipenem and cefepime with 55% resistance was reported. DDST method was performed for 37 strains for the MBl detection. Among the 37 isolate, 30 strains were MBL-producing with imipenem-EDTA method. Twelve strains (18% were carriers of VIM1 gene using the PCR method. Conclusion: In the present study, the prevalence of strains producing MBL genes in strains of hospitals is a growing trend; correct prescription of medications can prevent the spread of resistant pathogens. It is suggested that molecular methods for rapid detection of resistance genes can be used to prevent the spread of this genes.

  19. Spread of TEM, VIM, SHV, and CTX-M β-Lactamases in Imipenem-Resistant Gram-Negative Bacilli Isolated from Egyptian Hospitals

    Directory of Open Access Journals (Sweden)

    El sayed Hamdy Mohammed


    Full Text Available Carbapenem-resistant Gram-negative bacilli resulting from β-lactamases have been reported to be an important cause of nosocomial infections and are a critical therapeutic problem worldwide. This study aimed to describe the prevalence of imipenem-resistant Gram-negative bacilli isolates and detection of blaVIM, blaTEM, blaSHV, blaCTX-M-1, and blaCTX-M-9 genes in these clinical isolates in Egyptian hospitals. The isolates were collected from various clinical samples, identified by conventional methods and confirmed by API 20E. Antibiotic susceptibility testing was determined by Kirby-Bauer technique and interpreted according to CLSI. Production of blaVIM, blaTEM, blaSHV, and blaCTX-M genes was done by polymerase chain reaction (PCR. Direct sequencing from PCR products was subsequently carried out to identify and confirm these β-lactamases genes. Out of 65 isolates, (46.1% Escherichia coli, (26.2% Klebsiella pneumoniae, and (10.7% Pseudomonas aeruginosa were identified as the commonest Gram-negative bacilli. 33(50.8% were imipenem-resistant isolates. 22 isolates (66.7% carried blaVIM, 24(72.7% had blaTEM, and 5(15% showed blaSHV, while 12(36%, 6(18.2%, and 0(0.00% harbored blaCTX-M-1, blaCTX-M-9, and blaCTX-M-8/25, respectively. There is a high occurrence of β-lactamase genes in clinical isolates and sequence analysis of amplified genes showed differences between multiple SNPs (single nucleotide polymorphism sites in the same gene among local isolates in relation to published sequences.

  20. Studies on the mechanism of action of imipenem (N-formimidoylthienamycin) in vitro: binding to the penicillin-binding proteins (PBPs) in Escherichia coli and Pseudomonas aeruginosa, and inhibition of enzyme activities due to the PBPs in E. coli. (United States)

    Hashizume, T; Ishino, F; Nakagawa, J; Tamaki, S; Matsuhashi, M


    The binding affinities of imipenem (N- formimidoylthienamycin ) to penicillin-binding proteins ( PBSs ) of Escherichia coli and Pseudomonas aeruginosa were determined by two different methods in which competition with [14C]benzylpenicillin for the binding sites was measured. By both methods imipenem was shown to have very high binding affinities to PBPs-2 and -4 in E. coli and P. aeruginosa, and appreciable affinities to most of their other major PBPs. But higher concentrations of imipenem were required for binding to the PBPs-3 in these bacteria. More direct information about the antibacterial activity of imipenem was obtained by measuring its inhibition of the peptidoglycan-synthetic enzyme activities of E. coli PBPs. The results of enzyme inhibitions were compatible with those obtained in binding experiments. The antibiotic inhibited the transpeptidase activities of PBPs-1A, -1B and -2, and the D-alanine carboxypeptidase activities of PBPs-4 and -5. The antibiotic also seemed to cause strong inhibition of the transglycosylase activity of PBP-1A by some unknown mechanism. It inhibited the transpeptidase activity of PBP-3 only weakly, which is consistent with the findings that it had low binding affinity to PBP-3 and did not inhibit septum formation by the cells.

  1. Rapid increase in resistance to third generation cephalosporins, imipenem and co-resistance in Klebsiella pneumoniae from isolated from 7,140 blood-cultures (2010-2014) using EARS-Net data in Spain. (United States)

    Aracil-García, Belén; Oteo-Iglesias, Jesús; Cuevas-Lobato, Óscar; Lara-Fuella, Noelia; Pérez-Grajera, Isabel; Fernández-Romero, Sara; Pérez-Vázquez, María; Campos, José


    An analysis was made about the evolution of resistance to 3rd generation cephalosporins, imipenem, and other antibiotics in invasive isolates of Klebsiella pneumoniae (K. pneumoniae) according to the Spanish EARS-Net database (2010-2014). Forty-two hospitals from 16 Autonomous Communities with an approximate population coverage of 33% participated. A total 7,140 pneumoniae corresponding to the same number of patients were studied. Overall resistance percentages (I+R) were: cefotaxime 15.8%, ceftazidime 13.7%, imipenem 1.7%, ciprofloxacin 20.1%, tobramycin 14.1%, gentamicin 10.4%, and amikacin 1.9%. Resistance to 3rd generation cephalosporins increased from 9.8% (2010) to 19% (2014); to ciprofloxacin from 15.4% (2010) to 19.6% (2014); to gentamicin from 6.2% (2010) to 10.3% (2014) and to tobramycin from 7.1% (2010) to 14.2% (2014) (presistance to 3rd generation cephalosporins, ciprofloxacin, and aminoglycosides increased from 3.3% (2010) to 9.7% (2014) (pResistance to imipenem also increased from 0.27% (2010) to 3.46% (2014) (presistant to imipenem, of which 104 (86%) produced carbapenemases: 74 OXA-48, 14 VIM, 9 KPC (6 KPC-2 and 3 KPC-3), 6 IMP, and 1 GES. Over the 5 year period (2010-2014), resistance to 3rd generation cephalosporins in invasive K. pneumoniae in Spain has doubled. The combined resistance to 3rd generation cephalosporins, ciprofloxacin, and aminoglycosides has tripled, and imipenem resistance has increased almost 13 times, mostly due to the spread of carbapenemase-producing isolates. Copyright © 2016 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  2. Estudo da suscetibilidade "in vitro" a um novo antimicrobiano (IMIPENEM de patógenos isolados de pacientes hospitalares em vários centros

    Directory of Open Access Journals (Sweden)

    Cid Vieira Franco de Godoy


    Full Text Available O imipenem é um novo antibiótico Beta lactâmico, carbapenêmico, altamente potente e com amplo espectro de atividade antimicrobiana. Com intuito de comprovar a eficácia "in vitro" deste fármaco em patógenos mais freqüentes em nosso meio, descrevem os autores, os resultados das provas de suscetibilidade por discos e/ou a correspondência por provas de diluição para determinação da concentração inibitória mínima (CIM em 1230 cepas compreendendo 41 diferentes espécies bacterianas recém-isoladas, principalmente de pacientes hospitalares em 5 diferentes centros médicos de Sáo Paulo, Rio de Janeiro e Salvador. Nossos resultados preliminares com o antibiótico, em fase final de experimentação clínica e laboratorial, em nosso meio, foram muito promissores, com 96.79% de cepas suscetíveis pela prova do disco (10 μg de imipenem e 92,31% de correspondência pela determinação do CIM (concentrações de até 4μg/ml. Das 9 espécies bacterianas mais freqüentemente isoladas, correspondendo a 1008 (82% das 1230 cepas de nosso material, as sensibilidades pela prova do disco foram de 99% (E. coli, 93% (Pseudomonas aeruginosas, 87% (Staphylococcus aureus, 100% (Klebsiella pneumoniae, 98% (Klebsiella sp e 100% (Streptococcus faecalis com boa correspondência pela determinação do CIM até 8μg/ml; e 100% para o anaeróbio Bacteróides sp (CIM até 4μg/ml. Ressaltam os autores a eficácia "in vitro" contra patógenos hospitalares que apresentam elevados índices de resistência à grande maioria de antibióticos como o Pseudomonas aeruginosa e para anaeróbios, notadamente o Bacteróides sp.

  3. Study on imipenem resistance and prevalence of blaVIM1 and blaVIM2 metallo-beta lactamases among clinical isolates of Pseudomonas aeruginosa from Mashhad, Northeast of Iran. (United States)

    Mirbagheri, Seyedeh Zohreh; Meshkat, Zahra; Naderinasab, Mahboubeh; Rostami, Sina; Nabavinia, Maryam Sadat; Rahmati, Mehdi


    The main cause of serious nosocomial infections is a Gram-negative pathogen known as Pseudomonas aeruginosa (P. aeruginosa). Carbapenems are widely used as an appropriate treatment for these infections, however resistance to these agents has been observed and is increasing. Metallo beta-lactamase (MBLs) enzyme is one of the main causes of resistance to carbapenem. In the current study the frequency and production of VIM1 and VIM2 by imipenem-resistant P. aeruginosa isolates of patients hospitalized in Imam Reza hospital were evaluated. In this study, 131 clinical samples were collected from patients hospitalized in Imam Reza hospital in Mashhad during a 15-month period from May 2011 to November 2012. After verification of P. aeruginosa isolates, antibiotic resistance patterns of isolates were determined for 14 antibiotics by Kirby-Bauer standard disk diffusion according to the CLSI guidelines. Combined-disk test was used for phenotypic determination of MBLs-producing isolates and after DNA extraction, genotypic determination of VIM1 and VIM2 metallo beta-lactamase genes was carried out using Multiplex-PCR. Of 63 imipenem-resistant isolates (48.5%), 56 (88.8%) were MBL-producing in phenotypic assessments. Also amongst imipenem-resistant isolates, the frequency of VIM1 and VIM2 genes were 58.7 and 3.17%, respectively. The results of the current study along with the results of the other conducted studies in Iran in recent years demonstrate that the average resistance to imipenem in P. aeruginosa isolates was 51.3% which has increased in comparison with the results in 2006 (32.9%). It was also determined that the frequency of VIM1 gene was more than VIM2 gene. In phenotypic assessment by using CD method, 49.6% of isolates were determined as MBLs-producing. The sensitivity and specificity of this method were verified in comparison with the results of PCR test.

  4. The Acinetobacter Outer Membrane Contains Multiple Specific Channels for Carbapenem β-Lactams as Revealed by Kinetic Characterization Analyses of Imipenem Permeation into Acinetobacter baylyi Cells. (United States)

    Morán-Barrio, Jorgelina; Cameranesi, María M; Relling, Verónica; Limansky, Adriana S; Brambilla, Luciano; Viale, Alejandro M


    The number and type of outer membrane (OM) channels responsible for carbapenem uptake in Acinetobacter are still not well defined. Here, we addressed these questions by using Acinetobacter baylyi as a model species and a combination of methodologies aimed to characterize OM channels in their original membrane environment. Kinetic and competition analyses of imipenem (IPM) uptake by A. baylyi whole cells allowed us to identify different carbapenem-specific OM uptake sites. Comparative analyses of IPM uptake by A. baylyi wild-type (WT) cells and ΔcarO mutants lacking CarO indicated that this OM protein provided a carbapenem uptake site displaying saturable kinetics and common binding sites for basic amino acids compatible with a specific channel. The kinetic analysis uncovered another carbapenem-specific channel displaying a somewhat lower affinity for IPM than that of CarO and, in addition, common binding sites for basic amino acids as determined by competition studies. The use of A. baylyi gene deletion mutants lacking OM proteins proposed to function in carbapenem uptake in Acinetobacter baumannii indicated that CarO and OprD/OccAB1 mutants displayed low but consistent reductions in susceptibility to different carbapenems, including IPM, meropenem, and ertapenem. These two mutants also showed impaired growth on l-Arg but not on other carbon sources, further supporting a role of CarO and OprD/OccAB1 in basic amino acid and carbapenem uptake. A multiple-carbapenem-channel scenario may provide clues to our understanding of the contribution of OM channel loss or mutation to the carbapenem-resistant phenotype evolved by pathogenic members of the Acinetobacter genus. Copyright © 2017 American Society for Microbiology.

  5. Salmonella serovars and antimicrobial resistance in strains isolated from wild animals in captivity in Sinaloa, Mexico. (United States)

    Silva-Hidalgo, Gabriela; López-Valenzuela, Martin; Juárez-Barranco, Felipe; Montiel-Vázquez, Edith; Valenzuela-Sánchez, Beatriz


    The aim of the present study was to evaluate the frequency of antibiotic resistance in Salmonella spp. strains from wild animals in captivity at the Culiacan Zoo and the Mazatlan Aquarium in Sinaloa, Mexico. We identified 17 different Salmonella enterica serovars at a prevalence of 19.90% (Culiacan Zoo) and 6.25% (Mazatlan Aquarium). Antibiotic sensitivity tests revealed that, of the 83 strains studied, 100% were multidrug resistant (MDR). The drugs against which the greatest resistance was observed were: penicillin, erythromycin, dicloxacillin, ampicillin, cephalothin, and chloramphenicol. We therefore conclude that MDR is common among Salmonella isolates originating from wild animals in captivity in Sinaloa.

  6. Increased incidence of postoperative infections during prophylaxis with cephalothin compared to doxycycline in intestinal surgery

    DEFF Research Database (Denmark)

    Baatrup, Gunnar; Nilsen, Roy M; Svensen, Rune


    BACKGROUND: The antibiotics used for prophylaxis during surgery may influence the rate of surgical site infections. Tetracyclines are attractive having a long half-life and few side effects when used in a single dose regimen. We studied the rate of surgical site infections during changing regimens...... of antibiotic prophylaxis in medium and major size surgery. METHODS: Prospective registration of surgical site infection following intestinal resections and hysterectomies was performed. Possible confounding procedure and patient related factors were registered. The study included 1541 procedures and 1489......, is an attractive candidate for antibiotic prophylaxis in medium and major size intestinal surgery....

  7. Combination therapy with thioridazine and dicloxacillin combats methicillin-resistant Staphylococcus aureus infection in Caenorhabditis elegans

    DEFF Research Database (Denmark)

    Poulsen, Marianne Østergaard; Schøler, Lone; Nielsen, Anette


    , but experiments in simple animal models have not been performed. In the present study, we introduced Caenorhabditis elegans infected by S. aureus as an in vivo model to test the effect of TZ as a helper drug in combination with DCX. Because TZ is an anthelmintic, initial experiments were carried out to define...... the thresholds of toxicity, determined by larval development, and induction of stress-response markers. No measurable effects were seen at concentrations of less than 64 mg TZ l(-1). Seven different MRSA strains were tested for pathogenicity against C. elegans, and the most virulent strain (ATCC 33591......) was selected for further analyses. In a final experiment, full-grown C. elegans were exposed to the test strain for 3 days and subsequently treated with 8 mg DCX l(-1) and 8 mg TZ l(-1) for 2 days. This resulted in a 14-fold reduction in the intestinal MRSA load as compared with untreated controls. Each drug...

  8. Susceptibility of imipenem-resistant Pseudomonas aeruginosa to ...

    African Journals Online (AJOL)

    The fruits of the date palm (Phoenix dactylifera L.) are consumed throughout the world and are an important part of the diet in the Middle East. Dates at tamar stage contain a wide array of flavones, but little is known about the antimicrobial of flavonoid glycosides compounds in dates. In this study, we evaluated the ...

  9. Dicloxacillin induces CYP2C19, CYP2C9 and CYP3A4 in vivo and in vitro

    DEFF Research Database (Denmark)

    Stage, Tore Bjerregaard; Graff, Magnus; Wong, Susan


    -time curve from 0-24h of omeprazole (CYP2C19) (geometric mean ratio (GMR) [95% confidence interval (CI)]: 0.33 [0.24-0.45]), tolbutamide (CYP2C9) (GMR [95% CI]: 0.73 [0.65-0.81]) and midazolam (CYP3A4) (GMR [95% CI]: 0.54 [0.41-0.72]). Additionally, other relevant pharmacokinetic parameters were affected...

  10. Purification and characterization of inducible beta-lactamases in Aeromonas spp. (United States)

    Iaconis, J P; Sanders, C C


    beta-Lactamases from Aeromonas hydrophila and A. sobria were purified and characterized. Both species produced beta-lactamases that were inducible by either cefoxitin or imipenem. These species were resistant to ampicillin and cephalothin but not imipenem. Isoelectric focusing of sonic extracts revealed one band at pI 8.0 and a second band at pI 7.0 for A. hydrophila. Likewise, A. sobria produced two bands, one at pI 8.4 and the other at pI 7.0. Two enzymes from each species were separated by flatbed electrofocusing gel and purified to homogeneity. The molecular weight of the pI 7.0 enzyme (A1) from both species was estimated to be 42,500, whereas the pI 8.0 (A2h) and 8.4 (A2s) enzymes of A. hydrophila and A. sobria had molecular weights of 31,500 and 35,000, respectively, on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The relative Vmax values for cephalothin, penicillin, and imipenem for these enzymes indicated that A1 was primarily a cephalosporinase while A2h and A2s were penicillinases highly active against carbapenems. A1 was susceptible to inhibition by cloxacillin, while the A2 enzymes were inhibited by clavulanic acid and EDTA and required zinc for activity. Thus, there appear to be two distinct inducible beta-lactamases in A. hydrophila and A. sobria that play an important role in the beta-lactam resistance of these species.

  11. Drug: D02348 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D02348 Drug Dicloxacillin (USAN/INN) C19H17Cl2N3O5S 469.0266 470.3264 D02348.gif Antibacterial...illins J01CF01 Dicloxacillin D02348 Dicloxacillin (USAN/INN) USP drug classification [BR:br08302] Antibacterial...nfectives [BR:br08307] Antibacterials Cell wall biosynthesis inhibitor Penicillin binding proteins inhibitor...s Beta-lactam, Penicillins Dicloxacillin D02348 Dicloxacillin (USAN/INN) Antii

  12. In vivo pharmacokinetics/pharmacodynamics of colistin and imipenem in Pseudomonas aeruginosa biofilm infection

    DEFF Research Database (Denmark)

    Hengzhuang, Wang; Wu, Hong; Ciofu, Oana


    Many Pseudomonas aeruginosa isolates from the airways of patients with cystic fibrosis (CF) are sensitive to antibiotics in susceptibility testing, but eradication of the infection is difficult. The main reason is the biofilm formation in the airways of patients with CF. The pharmacokinetics (PKs...

  13. Mutant Prevention Concentrations of Imipenem and Meropenem against Pseudomonas aeruginosa and Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    E. Dahdouh


    Full Text Available The aim of this study was to determine the usefulness of the MPC of carbapenems against clinical isolates of Pseudomonas spp. and Acinetobacter spp. and to assess its possible relationship with mechanisms of resistance. Detection of the mechanisms of resistance was performed using Antibiotic Susceptibility Testing, Double Disk Synergy, disk antagonism, addition of NaCl to the medium, addition of PBA or EDTA to Carbapenem disks, addition of PBA to Cefoxitin disks, and CCCP test for 10 Pseudomonas spp. and Acinetobacter baumannii strains. The MIC and MPC were determined using the broth macrodilution and plate dilution methods, respectively. Four Acinetobacter baumannii strains produced MBL. Two of them produced Oxacillinase and one produced ESBL. Two Pseudomonas spp. isolates produced both KPC and MBL. The resistant Acinetobacter spp. and Pseudomonas spp. strains had higher MPC values than susceptible ones. However, the Mutant Selection Window was found to be dependent on the degree of resistance but not on a particular mechanism of resistance. The usefulness of the MPC was found to be dependent on its value. Based on our data, we recommend determining the MPC for each isolate before using it during treatment. Furthermore, the use of T>MSW instead of T>MIC is suggested.

  14. Biochemical Characterization of β-Lactamases from Mycobacterium abscessus Complex and Genetic Environment of the β-Lactamase-Encoding Gene. (United States)

    Ramírez, Ana; Ruggiero, Melina; Aranaga, Carlos; Cataldi, Angel; Gutkind, Gabriel; de Waard, Jacobus H; Araque, María; Power, Pablo


    The objectives of this study were to determine the kinetic parameters of purified recombinant BlaMab and BlaMmas by spectrophotometry, analyze the genetic environment of the blaMab and blaMmas genes in both species by polymerase chain reaction and sequencing, furthermore, in silico models of both enzymes in complex with imipenem were obtained by modeling tools. Our results showed that BlaMab and BlaMmas have a similar hydrolysis behavior, displaying high catalytic efficiencies toward penams, cephalothin, and nitrocefin; none of the enzymes are well inhibited by clavulanate. BlaMmas hydrolyzes imipenem at higher efficiency than cefotaxime and aztreonam. BlaMab and BlaMmas showed that their closest structural homologs are KPC-2 and SFC-1, which correlate to the mild carbapenemase activity toward imipenem observed at least for BlaMmas. They also seem to differ from other class A β-lactamases by the presence of a more flexible Ω loop, which could impact in the hydrolysis efficiency against some antibiotics. A -35 consensus sequence (TCGACA) and embedded at the 3' end of MAB_2874, which may constitute the blaMab and blaMmas promoter. Our results suggest that the resistance mechanisms in fast-growing mycobacteria could be probably evolving toward the production of β-lactamases that have improved catalytic efficiencies against some of the drugs commonly used for the treatment of mycobacterial infections, endangering the use of important drugs like the carbapenems.

  15. Co-release of dicloxacillin and thioridazine from catheter material containing an interpenetrating polymer network for inhibiting device-associated Staphylococcus aureus infection

    DEFF Research Database (Denmark)

    Stenger, Michael; Klein, Kasper; Grønnemose, Rasmus B


    Approximately half of all nosocomial bloodstream infections are caused by bacterial colonization of vascular catheters. Attempts have been made to improve devices using anti-adhesive or antimicrobial coatings; however, it is often difficult to bind coatings stably to catheter materials, and the low...... to an enhanced loading capacity of DCX when co-loaded with TDZ. Lastly, the IPN catheters were tested in a novel porcine model of central venous catheter-related infection, in which drug-loaded IPN catheters were found to significantly decrease the frequency of infection....

  16. Effect of beta-lactamase inhibitors on minimum inhibitory concentration of ampicillin and amoxicillin for Staphylococcus aureus strains. (United States)

    Paniagua, G L; Monroy, E; García, O; Vaca, S


    Seventy strains of Staphylococcus aureus isolated from the nasopharynx (80%), urinary tract (16%), skin (1 strain) and eyes (2 strains) of patients at the clinical laboratory "El eritrocito" were analyzed. Susceptibility to 12 antibiotics was tested by the method of Kirby-Bauer. Minimal inhibitory concentration (MIC) of ampicillin, ampicillin + sulbactam, amoxicillin and amoxicillin + clavulanic acid were determined by plate dilution. Percentages of resistance were: Penicillin and ampicillin (100%), ceftazidime (81.4%), erythromycin (68.6%), tetracycline (31.4%) trimethoprim-sulphametoxasol (25.7%), dicloxacillin and pefloxacin (12.8%), cefuroxime and cefotaxime (4.3%), gentamicin (2.8%), cephalothin (0%). All strains were resistant to three or more antibiotics, with higher percentages of resistance to four (31.4%), three (27.1%), five (21.4%) and six (12.9%) drugs. One strain was resistant to nine antibiotics and 5.9% were resistant to seven. 97.5% of the strains were beta-lactamase-positive. The MIC50 of ampicillin and amoxicillin was 500 micrograms/ml and the MIC90 were 1727 micrograms/ml and 2000 micrograms/ml, respectively. beta-lactamase inhibitors sulbactam and clavulanic acid reduced these values eightfold, except for the MIC50 of ampicillin + sulbactam whose reduction was sixteen fold. These results show that the combination of beta-lactamic + beta-lactamase inhibitor was more efficient than cephalosporins for killing these beta-lactamase-positive strains.

  17. Effect of various antibiotics on modulation of intestinal microbiota and bile acid profile in mice

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    Zhang, Youcai; Limaye, Pallavi B.; Renaud, Helen J.; Klaassen, Curtis D., E-mail:


    Antibiotic treatments have been used to modulate intestinal bacteria and investigate the role of intestinal bacteria on bile acid (BA) homeostasis. However, knowledge on which intestinal bacteria and bile acids are modified by antibiotics is limited. In the present study, mice were administered various antibiotics, 47 of the most abundant bacterial species in intestine, as well as individual BAs in plasma, liver, and intestine were quantified. Compared to the two antibiotic combinations (vancomycin + imipenem and cephalothin + neomycin), the three single antibiotics (metronidazole, ciprofloxacin and aztreonam) have less effect on intestinal bacterial profiles, and thus on host BA profiles and mRNA expression of genes that are important for BA homeostasis. The two antibiotic combinations decreased the ratio of Firmicutes to Bacteroidetes in intestine, as well as most secondary BAs in serum, liver and intestine. Additionally, the two antibiotic combinations significantly increased mRNA of the hepatic BA uptake transporters (Ntcp and Oatp1b2) and canalicular BA efflux transporters (Bsep and Mrp2), but decreased mRNA of the hepatic BA synthetic enzyme Cyp8b1, suggesting an elevated enterohepatic circulation of BAs. Interestingly, the two antibiotic combinations tended to have opposite effect on the mRNAs of most intestinal genes, which tended to be inhibited by vancomycin + imipenem but stimulated by cephalothin + neomycin. To conclude, the present study clearly shows that various antibiotics have distinct effects on modulating intestinal bacteria and host BA metabolism. - Highlights: • Various antibiotics have different effects on intestinal bacteria. • Antibiotics alter bile acid composition in mouse liver and intestine. • Antibiotics influence genes involved in bile acid homeostasis. • Clostridia appear to be important for secondary bile acid formation.

  18. Multi-drug resistant gram-negative enteric bacteria isolated from flies at Chengdu Airport, China. (United States)

    Liu, Yang; Yang, Yu; Zhao, Feng; Fan, Xuejun; Zhong, Wei; Qiao, Dairong; Cao, Yi


    We collected flies from Chengdu Shuangliu International Airport to examine for the presence of bacteria and to determine the sensitivity patterns of those bacteria. A total of 1,228 flies were collected from 6 sites around Chengdu Shuangliu International Airport from April to September 2011. The predominant species was Chrysomya megacephala (n=276, 22.5%). Antimicrobial-resistant gram-negative enteric bacteria (n=48) were isolated from flies using MacConkey agar supplemented with cephalothin (20 microg/ml). These were identified as Escherichia coli (n=37), Klebsiella pneumoniae (n=6), Pseudomonas aeruginosa (n=3) and Aeromonas hydrophila (n=2). All isolated bacteria were tested for resistance to 21 commonly used antimicrobials: amoxicillin (100%), ticarcillin (100%), cephalothin (100%), cefuroxime (100%), ceftazidime 1 (93.8%), piperacillin (93.8%), cefotaxime (89.6%), ticarcillin-clavulanate (81.3%), trimethoprim-sulfamethoxazole (62.5%), ciprofloxacin (54.2%), gentamicin (45.8%), cefepime (39.6%), tobramycin (39.6%), ceftazidime (22.9%), cefoxitin (16.7%), amikacin (16.7%), netilmicin (14.6%), amoxicillin-clavulanate (6.3%) and piperacillin-tazobactam (2.1%). No resistance to meropenem or imipenem was observed. Antibiotic resistance genes among the isolated bacteria were analyzed for by polymerase chain reaction. Thirty of the 48 bacteria with resistance (62.5%) possessed the blaTEM gene.

  19. Characterisation of KLUA-9, a beta-lactamase from extended-spectrum cephalosporin-susceptible Kluyvera ascorbata, and genetic organisation of bla(KLUA-9). (United States)

    Rodríguez, María Margarita; Power, Pablo; Bauvois, Cédric; Di Conza, José; Ayala, Juan A; Galleni, Moreno; Gutkind, Gabriel


    This study characterised the genetic environment of the chromosomally encoded bla(KLUA-9) gene from a clinical Kluyvera ascorbata isolate and performed a kinetic characterisation of KLUA-9. Purified KLUA-9 showed the highest catalytic efficacies towards benzylpenicillin, ampicillin, piperacillin, first-generation cephalosporins, cefuroxime and cefoperazone; like other 'cefotaximases', it showed a much higher rate of hydrolysis of cefotaxime than ceftazidime, whilst dicloxacillin, cefoxitin and imipenem behaved as poor substrates. A 9kb insert from K. ascorbata was cloned (Escherichia coli KK68C1) and sequenced. bla(KLUA-9) and its 266bp upstream flanking region (almost identical to the integron-associated bla(CTX-M-2)) are preceded by an aspat variant, a ypdABC-like operon and two open reading frames with unknown functions. Unlike ISCR1-associated bla(CTX-M-2) genes, we failed to detect the putative orf513 recombination sites. Instead, we were able to localise the 5bp target sites for insertion of ISEcp1B, suggesting that this element could be responsible for future (or still undetected) mobilisation of bla(KLUA-9) to more efficiently transferred elements.

  20. Distribution and Antimicrobial Susceptibility Pattern of Gram Negative Bacteria Causing Urinary Tract Infection (UTI and Detection New Delhi Metallo-beta-lactamase-1 (NDM-1 Producing Isolates in Ahwaz

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    Parviz Afrugh


    Full Text Available Background: Urinary tract infection (UTI is the commonest bacterial infectious disease in worldwide (especially in developing countries with a high rate of morbidity and financial cost. The management of UTI infections has been jeopardized by increase in immergence of antimicrobial drug resistance. Knowledge of the local bacterial etiology and susceptibility patterns is required to trace any change that might have occurred in time so that updated recommendation for optimal empirical therapy of UTI can be made. The aim of this investigation was distribution and antimicrobial susceptibility pattern of gram negative bacteria causing urinary tract infection (UTI and detection NDM-1 (new-delhi-metallo-beta-lactamase-1 producing isolates in Ahwaz. Materials and Methods: This cross-sectional study was done during a period of one year from April 2013 to March 2014. Clean catch midstream urine samples were collected from suspected patients to UTI. The isolates were identified based on morphological and biochemical testes. Culture was performed on routine microbiological media. Susceptibility testing was performed according CLSI (2013 guidelines. Detection of carbapenemase producing isolates was performed by modified hodge test (MHT. Metallo-beta-lactamase isolates were detected by imipenem-EDTA combined disc test (CDT. Results: In this study 708 gram negative organisms were isolated from urine samples. E.coli was the most common isolated bacteria (67% followed by Klebsiella spp. (26.5% and Enterobacter spp. (2.5%. In antibiotic susceptibility testing more than 90% of isolates were sensitive to tetracycline, ceftazidime, meropenem, amikacin, cefotaxime, imipenem, and cefepime. Isolates were more resistant to cephalothin (32%, co-trimoxazol (30.5%, and nalidixic acid (25%. Conclusion: In our results isolated organisms from outpatients showed very high sensitivity to common antibiotics. Continuous and regular monitoring of susceptibility pattern of

  1. mecA gene transferrability and antibiogram of zoonotic Staphylococcus intermedius from animals, staff and the environment in animal hospitals in Korea. (United States)

    Youn, Jung-Ho; Hwang, Sun Young; Kim, So Hyun; Koo, Hye Cheong; Shin, Sook; Lim, Suk-Kyung; Park, Yong Ho


    Staphylococcus intermedius is a common cause of otitis externa, pyoderma and wound infections in companion animals. Although S. intermedius infections are rare in humans, it is zoonotic, with several case reports describing fatal human infections. Presently, we sought to isolate S. intermedius strains from various sources at animal hospitals nationwide in Korea, examine their antibiotic susceptibilities, and determine the possibility of horizontal transmission between animals and humans. Pulsed field gel electrophoresis (PFGE) was used to compare the mecA gene in S. intermedius strains from humans, animals and the environment in animal hospitals. A total of 119 S. intermedius strains were isolated from 529 samples. Using the disk-diffusion method over 90% of the isolates were susceptible to cephalothin, amoxicillin-clavulanic acid, vancomycin, imipenem, nitroflurantoin and amikacin, whereas 97.5% and 98.3% of the isolates were resistant to penicillin and ampicillin, respectively. Among the 39 S. intermedius strains harbouring mecA, similar PFGE patterns were observed between seven isolates from an animal, two isolates from veterinary staff and the environment in one animal hospital, and single isolates from an animal and a veterinarian at another hospital. This result suggests the possibility of horizontal transmission of S. intermedius containing mecA between humans, animals and the environment in animal hospitals and also emphasizes on the importance of S. intermedius with mecA as a possible emerging threat to public health.

  2. Potential enterotoxicity and antimicrobial resistance pattern of Aeromonas species isolated from pet turtles and their environment. (United States)

    Wimalasena, S H M P; Shin, Gee-Wook; Hossain, Sabrina; Heo, Gang-Joon


    To investigate the potential enterotoxicity and antimicrobial resistance of aeromonads from pet turtles as a risk for human infection, one hundred and two Aeromonas spp. were isolated from the feces, skin and rearing environments of pet turtles and identified by biochemical and gyrB sequence analyses. Aeromonas enteropelogenes was the predominant species among the isolates (52.9%) followed by A. hydrophila (32.4%), A. dharkensis (5.9%), A. veronii (4.9%) and A. caviae (3.9%). Their potential enterotoxicities were evaluated by PCR assays for detecting genes encoding cytotoxic enterotoxin (act) and two cytotonic enterotoxins (alt and ast). 75.8% of A. hydrophila isolates exhibited the act+/alt+/ast+ genotype, whereas 94.4% of A. enteropelogenes isolates were determined to be act-/alt-/ast-. In an antimicrobial susceptibility test, most isolates were susceptible to all tested antibiotics except amoxicillin, ampicillin, cephalothin, chloramphenicol and tetracycline. Non-susceptible isolates to penicillins (ampicillin and amoxicillin) and fluoroquinolones (ciprofloxacin and norfloxacin) were frequently observed among the A. enteropelogenes isolates. Few isolates were resistant to imipenem, amikacin, ceftriaxone and cefotaxime. Collectively, these results suggest that pet turtles may pose a public health risk of infection by enterotoxigenic and antimicrobial resistant Aeromonas strains.

  3. In vitro activities of 22 beta-lactam antibiotics against penicillin-resistant and penicillin-susceptible viridans group streptococci isolated from blood. (United States)

    Alcaide, F; Liñares, J; Pallares, R; Carratala, J; Benitez, M A; Gudiol, F; Martin, R


    A total of 410 strains of viridans group streptococci isolated consecutively from blood were tested by the microdilution method for in vitro susceptibility to 22 beta-lactam antibiotics. One hundred thirty-eight strains (33.6%) were resistant to penicillin with a MIC range of 0.25 to 8 micrograms/ml. MICs of all beta-lactam agents tested were higher for penicillin-resistant strains than for susceptible strains. These antibiotics were classified into three groups according to their in vitro activities (MICs at which 50 and 90% of the isolates are inhibited). Beta-Lactams of the first group (these included imipenem, cefpirome, FK-037, cefditoren, cefotaxime, ceftriaxone, and cefepime) showed activities higher than or similar to that of penicillin against penicillin-resistant viridans group streptococci. However, 80% of highly penicillin-resistant Streptococcus mitis organisms required cefotaxime and ceftriaxone MICs of > or = 2 micrograms/ml (range, 2 to 16 micrograms/ml). Beta-Lactams of the second group (cefpodoxime, ampicillin, amoxicillin-clavulanate, piperacillin, and cefuroxime) showed lower activities than penicillin. Finally, antibiotics of the third group (cephalothin, oxacillin, ceftazidime, cefixime, cefaclor, cefetamet, cefadroxil, cephalexin, and ceftibuten) showed poor in vitro activities. Therefore, some of the beta-lactam agents included in the first group could be an acceptable alternative in the treatment of serious infections due to strains highly resistant to penicillin, although clinical experience is needed. PMID:8619576

  4. Isolation of Shiga toxin-producing Escherichia coli from raw milk in Kermanshah, Iran. (United States)

    Mohammadi, Pantea; Abiri, Ramin; Rezaei, Mansour; Salmanzadeh-Ahrabi, Siavosh


    Infectious diarrhoeal diseases are great problem throughout the world and are responsible for considerable morbidity and mortality. Shiga toxin-producing Escherichia coli (STEC) is a major cause of gastroenteritis that may be complicated by hemorrhagic colitis (HC) or the hemolytic uremic syndrome (HUS), which is the main cause of acute renal failure in children. Food-borne outbreaks associated with Shiga toxin-producing Escherichia coli have been well documented worldwide. The aim of this study was to investigate the prevalence of Shiga toxin-producing Escherichia coli (STEC) strains in raw milk samples. Raw milk samples collected from various cow farms in Kermanshah, Iran during June - September 2009 were investigated for STEC using PCR targeting stx1 and stx2 and then eaeA. Of 206 samples, 36 (17.47%) were contaminated with STEC. STEC isolates harbored 56.41% and 43.59% stx 2 and stx 1 gene respectively. In antibiotic resistance test, all strains were sensitive to ceftazidime, cefepime, gentamicin, imipenem and ciprofloxacin. 23.08% of isolates were resistat to tetracycline, and 38.5% of them showed intermediate sensitvity to cephalothin. The high presence of STEC in raw milk confirms the important role of raw milk as putative vehicle of infection to human. Moreover, this study suggests that the development of antibiotic resistant STEC must be a major concern in Iran and more studies are needed to identify the prevalence of STEC in other food samples.

  5. A prospective, randomized, double-blinded, placebo-controlled trial of empirical teicoplanin in febrile neutropenia with persistent fever after imipenem monotherapy

    NARCIS (Netherlands)

    Erjavec, Z; de Vries-Hospers, HG; Halie, RM; Daenen, S

    Glycopeptide antibiotics are used extensively in the empirical treatment of febrile patients with neutropenia. To come to a more rational and restricted application of these expensive drugs and to reduce the risk of emergence of resistance, we carried out a prospective, double-blinded,

  6. Using Enzymes to Improve Antibiotic Effectiveness on "Staphylococcus Epidermidis" Biofilm Removal (United States)

    Candal, Carmen


    The effectiveness of five different enzymes as treatments against Staphylococcus biofilm growth was measured in the presence of antibiotics and alone. Protease was the least effective enzyme in biofilm removal with all antibiotics, and pectinase was the most effective with dicloxacillin and clindamycin. Also, dicloxacillin was the most effective…

  7. The Resistance of E.coli in Child Patients in Bingöl Region

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    İlhan Geçit


    Full Text Available Aim: In this study, it has been aimed to put forward the resistance of the antibiotic in urinary infections caused by E.coli. Material and Method: The samples of the urine culture sent from 1412 patients who referred to Bingol State Hospital with the suspicion of urinary tract infection between 2007-2011 were retrospectively analyzed. Those who have recently used the antibiotic were excluded from the study. Results: Of the urine cultures sent from 1412 patients with the suspicion of urinary tract infection, there was reproduction in 113 (8%. E.coli was proliferated in 78 patients (69% detected the reproduction in their urine culture. The gender distribution of the patients proliferated E.coli in their urine culture was respectively 13 male (17% and 65 girls (83%. The age range of the children detected the urinary tract infection acquired from the community was under 7 years 39%. The resistance rates of antibiotic for E.coli were found to be 71% for ampicillin, 53% for amoksilin-clavulanate, 51% for co-trimaksazol, 48% for cephalothin, 37% for cefuroxime, 30% for ciprofloxacin, 25% for cefepime, % 21 for norfloxacin, 21% for gentamicin, 6% for sulbactam-seforazom, 2% for amikacin, and 0% for imipenem and meropenem. Discussion: The resistance rates occurring against the antibiotics are getting more and more important because there has been a longer life expectancy in the age group of the children. For this reason, potential uropathogens and antibiotic sensitivities in children should be considered in the treatment by following closely.

  8. Phenotypic and molecular characterization of antimicrobial resistance in Proteus mirabilis isolates from dogs. (United States)

    Harada, Kazuki; Niina, Ayaka; Shimizu, Takae; Mukai, Yujiro; Kuwajima, Ken; Miyamoto, Tadashi; Kataoka, Yasushi


    Large-scale monitoring of resistance to 14 antimicrobial agents was performed using 103 Proteus mirabilis strains isolated from dogs in Japan. Resistant strains were analysed to identify their resistance mechanisms. Rates of resistance to chloramphenicol, streptomycin, enrofloxacin, trimethoprim/sulfamethoxazole, kanamycin, ampicillin, ciprofloxacin, cephalothin, gentamicin, cefoxitin and cefotaxime were 20.4, 15.5, 12.6, 10.7, 9.7, 8.7, 5.8, 2.9, 2.9, 1.9 and 1.9%, respectively. No resistance to ceftazidime, aztreonam or imipenem was found. Class 1 and 2 integrases were detected in 2.9 and 11.7% of isolates, respectively. Class 1 integrons contained aadB or aadB-catB-like-blaOXA10-aadA1, whereas those of class 2 contained sat-aadA1, dhfr1-sat-aadA1 or none of the anticipated resistance genes. Of five distinct plasmid-mediated quinolone-resistance (PMQR) genes, only qnrD gene was detected in 1.9% of isolates. Quinolone-resistance determining regions (QRDRs) of gyrA and parC from 13 enrofloxacin-intermediate and -resistant isolates were sequenced. Seven strains had double mutations and three had single mutations. Three of nine ampicillin-resistant isolates harboured AmpC-type β-lactamases (i.e. blaCMY-2, blaCMY-4 and blaDHA-1). These results suggest that canine Proteus mirabilis deserves continued surveillance as an important reservoir of antimicrobial resistance determinants. This is the first report, to our knowledge, describing integrons, PMQRs and QRDR mutations in Proteus mirabilis isolates from companion animals. © 2014 The Authors.

  9. Purification and Biochemical Characterization of the VIM-1 Metallo-β-Lactamase (United States)

    Franceschini, Nicola; Caravelli, Berardo; Docquier, Jean-Denis; Galleni, Moreno; Frère, Jean-Marie; Amicosante, Gianfranco; Rossolini, Gian Maria


    VIM-1 is a new group 3 metallo-β-lactamase recently detected in carbapenem-resistant nosocomial isolates of Pseudomonas aeruginosa from the Mediterranean area. In this work, VIM-1 was purified from an Escherichia coli strain carrying the cloned blaVIM-1 gene by means of an anion-exchange chromatography step followed by a gel permeation chromatography step. The purified enzyme exhibited a molecular mass of 26 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and an acidic pI of 5.1 in analytical isoelectric focusing. Amino-terminal sequencing showed that mature VIM-1 results from the removal of a 26-amino-acid signal peptide from the precursor. VIM-1 hydrolyzes a broad array of β-lactam compounds, including penicillins, narrow- to expanded-spectrum cephalosporins, carbapenems, and mechanism-based serine-β-lactamase inactivators. Only monobactams escape hydrolysis. The highest catalytic constant/Km ratios (>106 M−1 · s−1) were observed with carbenicillin, azlocillin, some cephalosporins (cephaloridine, cephalothin, cefuroxime, cefepime, and cefpirome), imipenem, and biapenem. Kinetic parameters showed remarkable variability with different β-lactams and also within the various penam, cephem, and carbapenem compounds, resulting in no clear preference of the enzyme for any of these β-lactam subfamilies. Significant differences were observed with some substrates between the kinetic parameters of VIM-1 and those of other metallo-β-lactamases. Inactivation assays carried out with various chelating agents (EDTA, 1,10-o-phenanthroline, and pyridine-2,6-dicarboxylic acid) indicated that formation of a ternary enzyme-metal-chelator complex precedes metal removal from the zinc center of the protein and revealed notable differences in the inactivation parameters of VIM-1 with different agents. PMID:11036013


    Rowlands, Ruth Estela Gravato; Ristori, Christiane Asturiano; Ikuno, Alice A.; Barbosa, Maria Luisa; Jakabi, Miyoko; Franco, Bernadette Dora Gombossy de Melo


    Salmonella is the most common etiological agent of cases and outbreaks of foodborne diarrheal illnesses. The emergence and spread of Salmonella spp., which has become multi-drug resistant and potentially more pathogenic, have increased the concern with this pathogen. In this study, 237 Salmonella spp., associated or not with foodborne salmonellosis in Brazil, belonging mainly to serotype Enteritidis, were tested for antimicrobial susceptibility and the presence of the virulence genes spvC, invA, sefA and pefA. Of the isolates, 46.8% were sensitive to all antimicrobials and 51.9% were resistant to at least one antimicrobial agent. Resistance to more than one antimicrobial agent was observed in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%) and nalidixic acid (16.9%). No strain was resistant to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxacin and imipenem. The invA gene was detected in all strains. Genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The gene sefA was detected in 31.6% of the strains and only among S. Enteritidis. Resistance and virulence determinants were detected in Salmonella strains belonging to several serotypes. The high rates of antibiotic-resistance in strains isolated from poultry products demonstrate the potential risk associated with the consumption of these products and the need to ensure good food hygiene practices from farm to table to reduce the spread of pathogens relevant to public health. PMID:25351537


    Directory of Open Access Journals (Sweden)

    Ruth Estela Gravato Rowlands


    Full Text Available Salmonella is the most common etiological agent of cases and outbreaks of foodborne diarrheal illnesses. The emergence and spread of Salmonella spp., which has become multi-drug resistant and potentially more pathogenic, have increased the concern with this pathogen. In this study, 237 Salmonella spp., associated or not with foodborne salmonellosis in Brazil, belonging mainly to serotype Enteritidis, were tested for antimicrobial susceptibility and the presence of the virulence genes spvC, invA, sefA and pefA. Of the isolates, 46.8% were sensitive to all antimicrobials and 51.9% were resistant to at least one antimicrobial agent. Resistance to more than one antimicrobial agent was observed in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9% and nalidixic acid (16.9%. No strain was resistant to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxacin and imipenem. The invA gene was detected in all strains. Genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The gene sefA was detected in 31.6% of the strains and only among S. Enteritidis. Resistance and virulence determinants were detected in Salmonella strains belonging to several serotypes. The high rates of antibiotic-resistance in strains isolated from poultry products demonstrate the potential risk associated with the consumption of these products and the need to ensure good food hygiene practices from farm to table to reduce the spread of pathogens relevant to public health.

  12. CTX-M-15 Type β-lactamases From Clinical Isolates of Escherichia coli by Polymerase Chain Reaction and DNA Sequencing

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    Mahboobeh Nakhaei Moghaddam


    Full Text Available Background E. coli is a common cause of urinary tract infection and bacteremia in humans. That is frequently resistant to β-lactam antibiotics. Objectives The aim of this study was to determine the antibiotic resistance and CTX-M extended-spectrum β-lactamases (ESBL carrying E. coli isolated in hospitals from two different areas in Iran. Methods In this descriptive cross-sectional study, 93 clinical isolates of E. coli were collected from urine culture of inpatients in Mashhad and Qom hospitals from August 2013 to February 2014. Bacteria were re-confirmed by Microgen kit. Antimicrobial and ESBL tests were performed using by standard disc diffusion method. Polymerase chain reaction (PCR was used for detection of plasmid mediated CTX-M-1 and CTX-M-2 ESBLs. Four of the blaCTX-M genes were sequenced. Statistical analysis carried out using SPSS (version 16 software and Chi-square test. Results High prevalent isolates were resistant to ampicillin, cephalothin, nalidixic acid and cotrimoxazole, but sensitive to imipenem, nitrofurantoin and amikacin. The ESBL phenotype was detected in 48 (51.6% isolates, 42 of which were carrying blaCTX-M gene. There was no significant difference between the β-lactamase-producing bacteria from the two studied cities. 81% and 85% of blaCTX-M carriers from hospitals in Qom and Mashhad were respectively found to have CTX-M-1 ESBL, whereas none of them showed CTX-M-2 ESBL cluster. BlaCTX-M-15 was found in four selected bacteria by sequencing. Conclusions This study showed a high rate of CTX-M-1 cluster and also presence of CTX-M-15 ESBL in two different areas of Iran, which emphasize the need for employing an excellent management program in antibiotic therapy.

  13. [Phenotypes of beta-lactam resistance in the genus Aeromonas]. (United States)

    Fosse, T; Giraud-Morin, C; Madinier, I


    This work aimed to investigate resistance profiles towards beta-lactam antibiotics in correlation with beta-lactamases production in the genus Aeromonas. In a series of 417 wild-type strains, biochemical identification and testing with 11 beta-lactams by the disk-diffusion method revealed 5 predominant phenotypes: A. hydrophila complex/class B, C and D beta-lactamases; A. caviae complex/class C and D beta-lactamases; A. veronii complex/class B and D beta-lactamases; A. schubertii spp./class D beta-lactamase; A. trota spp./class C beta-lactamase. A subgroup of 64 representative strains was submitted to MIC determination with 8 beta-lactam compounds alone and in combination with 3 beta-lactamase inhibitors (clavulanic acid, tazobactam and BRL 42715). Visualisation of beta-lactamases and pI determination were performed in all these 64 isolates by isoelectric focusing from crude extracts. The different Aeromonas species produced 1 to 3 of the following inducible enzymes: an imipenemase with low expression, which is difficult to detect with routine phenotype studies (class B, pI 8, imipenem MIC > 2 micrograms/ml), a cephalosporinase (class C, pI > 7 +/- 0.5, cephalothin MIC > 256 micrograms/ml), and an oxacillinase widely produced in the genus Aeromonas (class D, pI > 8.5, ticarcillin MIC > 256 micrograms/ml). In Aeromonas spp. resistance profile to beta-lactam antibiotics is correlated with naturally occurring phenotypes of beta-lactamases production. As a conclusion, the characterisation of these different enzymes is of therapeutic and taxonomic interest, in species notoriously difficult to identify.

  14. [Antimicrobial sensitivity of Escherichia coli strains with K1 antigen isolated from pregnant women and newborns]. (United States)

    Kaczmarek, Agnieszka; Budzyńska, Anna; Gospodarek, Eugenia


    The aim of this study was comparison of the susceptibility to antibiotics of E. coli strains with K1 antigen (E. coli K1+) and non-K1 E. coli strains (E. coli K1-). This study included 67 of E. coli K1+ and 67 of E. coli K1- strains isolated in the time period from June to September of 2008 from pregnant women and newborns hospitalized at dr. J. Biziel University Hospital number 2 L. Rydygier Collegium Medicum in Bydgoszcz Nicolaus Copernicus University in Toruń. Antimicrobial susceptibility of E. coli strains was tested by the disc-diffusion method, on the Mueller Hinton 2 Agar (Becton Dickinson). It was found that 64,2% of E. coli K1+ strains and 53,7% of E. coli K1-strains were susceptible to all tested antibiotics and chemioterapeutics. E. coli K1- strains were more often than E. coli K1+ nonsusceptible to at least one antimicrobial agent. The obtained results indicate that E. coli K1+ strains significant differed in the susceptibility to ampicillin/sulbactam (85,1% versus 95,5%) (p=0,041), cephalothin (70,1% versus 85,1%) (p=0,038) and tetracycline (91,0% versus 74,6%) (p=0,012) from E. coli K1-strains. All tested E. coli K1+ and K1-strains were sensitive to piperacillin/tazobactam, cefoperazone/sulbactam, cefotaxime, ceftazidime, cefepime, imipenem, amikacin, netilmicin and tigecycline. There weren't the ESBL-producing strains among tested E. coli K1+ and K1- rods.

  15. Disease: H00306 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available 766 PMID:6371440 (drug) Weber DJ, Wolfson JS, Swartz MN, Hooper DC Pasteurella multocida infections. Report ...not susceptible to dicloxacillin, cephalexin, clindamycin, or erythromycin. ICD-10: A28.0 MeSH: D010326 D012

  16. Development and validation of a quantitative confirmatory method for 30 β-lactam antibiotics in bovine muscle using liquid chromatography coupled to tandem mass spectrometry

    NARCIS (Netherlands)

    Rocco, Di M.; Moloney, M.; O'Beirne, T.; Earley, S.; Berendsen, B.; Furey, A.; Danaher, M.


    A method was developed for the confirmatory and quantitative analysis of 30 β-lactam antibiotic residues in bovine muscle. The method includes 12 penicillins (amoxicillin, ampicillin, cloxacillin, dicloxacillin, mecillinam, methicillin, nafcillin, oxacillin, penicillin G, penicillin V,

  17. Paroxetine (United States)

    ... your condition, symptoms, and personal and family medical history. You and your doctor will decide what type ... dextromethorphan (found in many cough medications; in Nuedexta); diazepam (Valium); dicloxacillin (Dynapen); digoxin (Lanoxin); dipyridamole (Persantine); diuretics (' ...

  18. Drug: D00344 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available - cilastatin sodium mixt; Primaxin (TN) Imipenem hydrate [DR:D00206], Cilastatin sodium [DR:D02194] Antibacterial... J01DH51 Imipenem and enzyme inhibitor D00344 Imipenem hydrate - cilastatin sodium (JP16) USP drug classification [BR:br08302] Antiba...cterials Beta-lactam, Other Imipenem and Cilastatin Sodium D00344 Imipenem hydrate - cilastatin sodium (JP16) PubChem: 7847410 ...

  19. Interspecies scaling of excretory amounts using allometry - retrospective analysis with rifapentine, aztreonam, carumonam, pefloxacin, miloxacin, trovafloxacin, doripenem, imipenem, cefozopran, ceftazidime, linezolid for urinary excretion and rifapentine, cabotegravir, and dolutegravir for fecal excretion. (United States)

    Srinivas, Nuggehally R


    1. Interspecies allometry scaling for prediction of human excretory amounts in urine or feces was performed for numerous antibacterials. Antibacterials used for urinary scaling were: rifapentine, pefloxacin, trovafloxacin (Gr1/low; 50%). Rifapentine, cabotegravir, and dolutegravir was used for fecal scaling (high; >50%). 2. The employment of allometry equation: Y = aW(b) enabled scaling of urine/fecal amounts from animal species. Corresponding predicted amounts were converted into % recovery by considering the respective human dose. Comparison of predicted/observed values enabled fold difference and error calculations (mean absolute error [MAE] and root mean square error [RMSE]). Comparisons were made for urinary/fecal data; and qualitative assessment was made amongst Gr1/Gr2/Gr3 for urine. 3. Average correlation coefficient for the allometry scaling was >0.995. Excretory amount predictions were largely within 0.75- to 1.5-fold differences. Average MAE and RMSE were within ±22% and 23%, respectively. Although robust predictions were achieved for higher urinary/fecal excretion (>50%), interspecies scaling was applicable for low/medium excretory drugs. 4. Based on the data, interspecies scaling of urine or fecal excretory amounts may be potentially used as a tool to understand the significance of either urinary or fecal routes of elimination in humans in early development.

  20. Novel plasmid-mediated beta-lactamase (MIR-1) conferring resistance to oxyimino- and alpha-methoxy beta-lactams in clinical isolates of Klebsiella pneumoniae. (United States)

    Papanicolaou, G A; Medeiros, A A; Jacoby, G A


    Klebsiella pneumoniae isolates from 11 patients at the Miriam Hospital were identified as resistant to cefoxitin and ceftibuten as well as to aztreonam, cefotaxime, and ceftazidime. Resistance could be transferred by conjugation or transformation with plasmid DNA into Escherichia coli and was due to the production of a beta-lactamase with an isoelectric point of 8.4 named MIR-1. In E. coli, MIR-1 conferred resistance to aztreonam, cefotaxime, ceftazidime, ceftibuten, ceftriaxone, and such alpha-methoxy beta-lactams as cefmetazole, cefotetan, cefoxitin, and moxalactam. In vitro, MIR-1 hydrolyzed cephalothin and cephaloridine much more rapidly than it did penicillin G, ampicillin, or carbenicillin. Cefotaxime was hydrolyzed at 10% the rate of cephaloridine. Cefoxitin inactivation could only be detected by a microbiological test. The inhibition profile of MIR-1 was similar to that of chromosomally mediated class I beta-lactamases. Potassium clavulanate had little effect on cefoxitin or cefibuten resistance and was a poor inhibitor of MIR-1 activity. Cefoxitin or imipenem did not induce MIR-1. The gene determining MIR-1 was cloned on a 1.4-kb AccI-PstI fragment. Under stringent conditions, probes for TEM-1 and SHV-1 genes and the E. coli ampC gene failed to hybridize with the MIR-1 gene. However, a provisional sequence of 150 bp of the MIR-1 gene proved to be 90% identical to the sequence of ampC from Enterobacter cloacae but only 71% identical to that of E. coli, thus explaining the lack of hybridization to the E. coli ampC probe. Plasmid profiles of the 11 K. pneumoniae clinical isolates were not identical, but each contained a plasmid from 40 to 60 kb that hybridized with the cloned MIR-1 gene. Both transfer-proficient and transfer-deficient MIR-1 plasmids belonged to the N incompatibility group. Thus, the resistance of these K. pneumoniae strains was the result of plasmid acquisition of a class I beta-lactamase, a new resistance determinant that expands the kinds

  1. Thioridazine potentiates the effect of a beta-lactam antibiotic against Staphylococcus aureus independently of mecA expression

    DEFF Research Database (Denmark)

    Poulsen, Marianne Østergaard; Jacobsen, Kirstine; Bonde, Mette


    The neuroleptic antipsychotic derivate thioridazine has been shown to increase the susceptibility of a methicillin-resistant Staphylococcus aureus (MRSA) isolate towards dicloxacillin. The aim of this study was to investigate the combinatorial effect of the two drugs on a broad selection...... susceptibility to dicloxacillin in the presence of thioridazine in all tested MRSA isolates. In contrast to previously published results, the synergistic effect was also applicable to methicillin-susceptible S. aureus (MSSA). We conclude that the combination of dicloxacillin and thioridazine potentiates...... of staphylococcal strains by analyzing a large collection of MRSA strains carrying different types of SCCmec, as well as MSSA strains. Transcription and translation of the resistance marker PBP2a encoded by mecA within the SCCmec cassette were analyzed by primer extension and western blotting. We observed increased...

  2. Antimicrobial spectrum, pharmacology and therapeutic use of antibiotics. Part 2: penicillins. (United States)

    Barza, M


    The mechanism of action, resistance, antibacterial spectrum, clinical pharmacology, adverse effects, and therapeutic and prophylactic use of penicillins are reviewed. The choice of a penicillin is discussed. The only indication for the penicillinase-resistant penicillins is the suspected or demonstrated presence of Staphylococcus aureus. There are no important differences in therapeutic effect among oxacillin, cloxacillin, dicloxacillin or flucloxacillin by the oral route, or among oxacillin, dicloxacillin, nafcillin or methicillin parenterally. Ampicillin is especially useful for infections due to Haemophilus influenzae and Escherchia coli and for serious disease due to enterococcus and Listeria monocytogenes. Carbenicillin and ticarcillin exhibit unique activity against gram-negative bacilli (except Klebsiella).

  3. Prevalence, antimicrobial resistance and risk factors for thermophilic Campylobacter infections in symptomatic and asymptomatic humans in Tanzania

    DEFF Research Database (Denmark)

    Komba, E. V. G.; Mdegela, R. H.; Msoffe, P. L. M.


    sulphate and lowest for ciprofloxacin (22.1%). The rates of resistance for other antibiotics (azithromycin, erythromycin, tetracycline, cephalothin, gentamycin, nalidixic acid, ampicillin, amoxycillin, norfloxacin, chloramphenicol) ranged from 44.1% to 89%. Comparison between disc diffusion and agar...

  4. Antimicrobial susceptibility of Staphylococcus aureus isolated from bovine mastitis in Europe and the United States

    DEFF Research Database (Denmark)

    De Oliveira, A. P.; Watts, J. L.; Salmon, S. A.


    (123), Switzerland (69), United States (53), and Zimbabwe (6). The antimicrobial agents tested were penicillin, ampicillin, oxacillin, cephalothin, ceftiofur, amoxicillin + clavulanate, penicillin + novobiocin, enrofloxacin, premafloxacin, erythromycin, clindamycin, lincomycin, pirlimycin, neomycin...

  5. Microbiological properties of a new cephalosporin, BL-S 339: 7-(phenylacetimidoyl-aminoacetamido)-3-(2-methyl-1,3,4-thiadiazol-5-ylthiomethyl)ceph-3-em-4-carboxylic acid. (United States)

    Misiek, M; Pursiano, T A; Leitner, F; Price, K E


    BL-S 339 is a new broad-spectrum, parenterally effective cephalosporin whose expression of antibacterial activity in vitro is markedly affected by the nature of the assay medium. When assayed in nutrient agar, BL-S 339 was more active than cephalothin against strains of Diplococcus pneumoniae, Streptococcus pyogenes, Escherichia coli, Serratia marcescens, Klebsiella pneumoniae, Enterobacter, and indole-positive Proteus sp. However, when assayed in Mueller-Hinton medium, its activity, especially against gram-negative bacteria, was reduced substantially, whereas the activity of cephalothin was virtually unaffected by the assay medium. The in vivo activity of BL-S 339 correlated well with its activity in nutrient agar; when administered subcutaneously to mice, it was therapeutically more efficacious than cephalothin in infections caused by both gram-positive and gram-negative bacteria. When BL-S 339 was administered intramuscularly to mice, the concentrations achieved in the blood were three times those achieved with cephalothin. BL-S 339 was bound to human serum proteins to the same extent as cephalothin. Recovery of BL-S 339 in the urine within the 24-hr period after intramuscular administration to rats was three times that of cephalothin.

  6. Comparison of in Vitro Activity of Doripenem versus Old Carbapenems against Pseudomonas Aeruginosa Clinical Isolates from both CF and Burn Patients


    Hojabri, Zoya; Ahangarzadeh Rezaee, Mohammad; Nahaei, Mohammad Reza; Soroush, Mohammad Hossein; Ghojazadeh, Morteza; Pirzadeh, Tahereh; Davodi, Mostafa; Ghazi, Mona; Bigverdi, Reza; Pajand, Omid; Aghazadeh, Mohammad


    Purpose: The antimicrobial activity of doripenem in comparison of imipenem, meropenem and ertapenem among Pseudomonas aeruginosa isolated from burn and Cystic Fibrosis (CF) patients were determined. Methods: Metallo-β-lactamase (MBL) genes in imipenem non susceptible P. aeruginosa isolates were detected using PCR method. The in vitro susceptibilities of doripenem, imipenem, meropenem and ertapenem were determined by Etests. MIC50 and MIC90 for corresponding antibiotics were determined individ...

  7. Ertapenem Injection (United States)

    ... imipenem/cilastatin (Primaxin), doripenem (Doribax), or meropenem (Merrem); local anesthetics such as bupivacaine (Marcaine), etidocaine (Duranest), lidocaine, mepivacaine (Carbocaine, Prolocaine), or prilocaine (Citanest); cephalosporins such ...

  8. Fracture risk associated with use of antibiotics

    DEFF Research Database (Denmark)

    Vestergaard, Peter


    BACKGROUND: Data have pointed at an impaired fracture healing with fluoroquinolones and thus potentially a decreased bone biomechanical competence. OBJECTIVES: To study fracture risk associated with antibiotics. METHODS: Case control study. There were 124,655 fracture cases and 373,962 age...... and gender matched controls. The main exposure was use of various groups of antibiotics. Confounder control was performed for social variables, contacts to hospitals and general practitioners, alcoholism and a number of other variables. RESULTS: An increased risk of any fracture (OR =1. 45, 95% CI: 1. 42 -1...... fractures with dicloxacillin and flucloxacillin. None of the other groups of antibiotics against bacteria, tuberculosis, virus, and fungi were systematically associated with any major change in the risk of fractures. CONCLUSION: Dicloxacillin and flucloxacillin seem associated with an increased risk...

  9. Proportion of bacteria causing healthcare associated infection in ...

    African Journals Online (AJOL)

    Proportion of bacteria causing healthcare associated infection in Khartoum North Teaching Hospital. ... isolates were highly sensitive to antibiotic such as ceftriaxone, ciprofloxacin and imipenem, while P. aeruginosa showed resistant to many commonly used antibiotics, but was sensitive to imipenem and pipracillin.

  10. Drug-resistant post-neurosurgical nosocomial Acinetobacter ...

    African Journals Online (AJOL)



    Feb 28, 2012 ... Moreover, the apparent emergence of carbapenem-resistant. Acinetobacter meningitis is very important in terms of treatment (Metan et al., 2007;Baek- Kim et al., 2009; Cascio et al., 2010); both imipenem and meropenem have been used to treat. Acinetobacter meningitis. However, imipenem usage may.

  11. Drug: D04515 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D04515 Drug Imipenem (INN); Imipenem anhydrous; IPM C12H17N3O4S 299.094 299.3461 D04515.gif Antibacterial...sis Antiinfectives [BR:br08307] Antibacterials Cell wall biosynthesis inhibitor Penicillin binding proteins

  12. Nonfermenting gram-negative bacilli infections in a tertiary care hospital in Kolar, Karnataka

    Directory of Open Access Journals (Sweden)

    A Malini


    Conclusion : P. aeruginosa and A. baumannii were the common NFGNB isolated in our study from patients of, urinary tract infection, bacteremia, surgical site infections, and ventilator associated pneumonia. P. aeruginosa showed good sensitivity to imipenem, amikacin, and cefoperazone while A. baumannii showed good sensitivity to imipenem and piperacillin.

  13. Drug: D00206 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available ntiinfectives [BR:br08307] Antibacterials Cell wall biosynthesis inhibitor Penicillin binding proteins inhib...acterial penicillin binding proteins inhibitor ko00550 Peptidoglycan biosynthesis A...D00206 Drug Imipenem hydrate (JP16); Imipenem (USP); IPM C12H17N3O4S. H2O 317.1045 317.3614 D00206.gif Antib

  14. High-level expression, purification, polyclonal antibody preparation ...

    African Journals Online (AJOL)



    Feb 14, 2011 ... amino acids, dipeptides containing a basic residue, imipenem and related zwitterionic carbapenems ... they correspondingly produce larger channels (that still bind imipenem), which indicates that these loops ... cultured using LB broth containing ampicillin (100 mg/ml). The plasmid DNA was extracted with ...

  15. Clonal spread of Staphylococcus aureus with reduced susceptibility to oxacillin in a dermatological hospital unit

    DEFF Research Database (Denmark)

    Thomsen, Marianne Kragh; Rasmussen, Mads; Fuursted, Kurt


    In November 2000, we became aware of isolates of Staphylococcus aureus with borderline resistance to oxacillin (BORSA) from patients in the Department of Dermatology, Aarhus University Hospital. The objective was to describe the isolates phenotypically and genotypically and to assess possible...... carrier rates of S. aureus in dermatological patients and high consumption rates of dicloxacillin in the department might facilitate transmission. Following improvement of the general infection control measures, and after reassessment of the antibiotic policy in the department, the outbreak has...

  16. Simultaneous determination of seven penicillins in muscle, liver and kidney tissues from cattle and pigs by a multiresidue high-performance liquid chromatographic method. (United States)

    Sørensen, L K; Snor, L K; Elkaer, T; Hansen, H


    A high-performance liquid chromatographic (HPLC) method based on solid-phase extraction (SPE) was developed for determination of amoxicillin, penicillin G (benzylpenicillin), ampicillin, oxacillin, cloxacillin, nafcillin and dicloxacillin in muscle, liver and kidney tissues of pigs and cattle. The compounds were extracted in aqueous solution by precipitation of organic materials with a mixture of sulphuric acid and sodium tungstate. The extract was cleaned up by SPE on a divinylbenzene-co-N-vinylpyrrolidone polymeric sorbent. Further clean-up was performed by liquid-liquid partition with diethyl ether. The extract was derivatised with benzoic anhydride and 1,2,4-triazole mercury (II) reagent. Chromatography was performed by reversed-phase gradient HPLC on a C18 column with ultraviolet detection at 323 nm. The limits of detection estimated by a conservative model were in the range 8.9-11.1 microg/kg for amoxicillin, penicillin G, ampicillin, oxacillin, cloxacillin and nafcillin and 18.3-20.9 microg/kg for dicloxacillin. The mean recovery range was 66-77% for amoxicillin, 73-75% for penicillin G, 81-82% for ampicillin, 73-76% for oxacillin, 74-75% for cloxacillin, 66-72% for nafcillin and 58-65% for dicloxacillin.

  17. Molecular characterization and occurrence of extended-spectrum beta-lactamase resistance genes among Salmonella enterica serovar Corvallis from Thailand, Bulgaria and Denmark

    DEFF Research Database (Denmark)

    Archambault, Marie; Petrov, P.; Hendriksen, Rene S.


    antimicrobial agents tested, whereas 41 were resistant to three or more antimicrobials. Most resistance was observed among the isolates from Bulgaria. Of the 25 isolates from Bulgaria, 20 displayed resistance to ampicillin and the cephalosporins ceftiofur and cephalothin. All 20 isolates tested negative for bla...

  18. Cephalosporins can be prescribed safely for penicillin-allergic patients. (United States)

    Pichichero, Michael E


    The widely quoted cross-allergy risk of 10% between penicillin and cephalosporins is a myth. Cephalothin, cephalexin, cefadroxil, and cefazolin confer an increased risk of allergic reaction among patients with penicillin allergy. Cefprozil, cefuroxime, cefpodoxime, ceftazidime, and ceftriaxone do not increase risk of an allergic reaction.

  19. EAMJ August Sporadic.indd

    African Journals Online (AJOL)


    Aug 1, 2009 ... rural sites in western Kenya to explore differences in bacterial aetiologies, antimicrobial resistance patterns, ... clindamycin, erythromycin, cephalothin, nalidixic acid, tetracycline, and TMP/SMX (8). Serotypes ...... enterococci, campylobacter jejuni, and gram-negative bacteria resistant to antimicrobial agents.

  20. Antimicrobial susceptibility of Corynebacterium group D2. (United States)

    Santamaría, M; Ponte, C; Wilhelmi, I; Soriano, F


    The in vitro susceptibility of 30 Corynebacterium group D2 strains to nine antimicrobial agents was determined. Vancomycin and norfloxacin were the most active agents tested. All strains were resistant to ampicillin and cephalothin, all except one were resistant to gentamicin, and the activity of erythromycin, novobiocin, tetracycline, and rifampin varied. PMID:4083869

  1. US Army Institute of Surgical Research Annual Research Progress Report for Fiscal Year 1988 (United States)


    Kanamycin 10. Cefsulodin a 10. Sulfadiazine 11. Chloramphenicol 11. Colistin 11. Oxacillin a 12. Tetracycline 12. Sulfadizine a 12. Cephalothin a 1...and Fiers W: Recombinant tumor necrosis factor: Its effect and synergism with interferon-gamma on a variety of normal and transformed human cell

  2. Relative Inactivation by Staphylococcus aureus of Eight Cephalosporin Antibiotics (United States)

    Fong, Ignatius W.; Engelking, Elin R.; Kirby, William M. M.


    These studies extend the recent observation that cefazolin is inactivated to a greater extent than cephaloridine by some strains of penicillinase-producing Staphylococcus aureus, whereas cephalothin undergoes little if any inactivation. In Mueller-Hinton broth (inoculum, 3 × 106) 100 recently isolated strains had minimal inhibitory concentrations (MICs) ≤ 2 μg/ml for cephalothin and cephaloridine, whereas in Trypticase soy broth (TSB) 50% had MICs > 2 μg/ml and 10% (designated “resistant” strains) were >8 μg/ml for cephaloridine but remained ≤2 μg/ml for cephalothin. A large inoculum (3 × 107) of strains with high MICs in TSB almost completely inactivated 50 μg of cefazolin per ml in 6 h, with progressively less inactivation, in the following order, of cephaloridine, cephalexin, cephradine, cephapirin, and cefamandole; cefoxitin and cephalothin underwent little if any inactivation. The greater inactivation in TSB than in Mueller-Hinton broth appeared to be due to a greater production of β-lactamases by each colony-forming unit, since the inoculum size in the two broths was not significantly different. In contrast, “susceptible” strains (MICs ≤ 2 μg/ml in both broths) inactivated cephaloridine more than cefazolin, and equal amounts of powdered bacterial extracts confirmed the fact that qualitatively different β-lactamases were produced by the susceptible and resistant strains. Disk diffusion tests were unreliable in separating the two groups of staphylococci. The clinical significance of inactivation by strains with high MICs is not known but, unless susceptibility can be clearly established, cephalothin appears preferable for severe staphylococcal infections, since it undergoes little if any inactivation by any strains of staphylococci. PMID:938023

  3. Neurotoxicity of carbapenem antibacterials. (United States)

    Norrby, S R


    Similar to other beta-lactam antibacterials, carbapenems have a neurotoxic potential that seems to be higher than that of the penicillins and cephalosporins. Seizures have been reported in several large studies of patients treated with imipenem/cilastatin. However, it seems clear that the main factor increasing the risk of neurotoxicity with imipenem/cilastatin is administration of excessive dosages relative to bodyweight and/or renal function. If the manufacturer's dosage recommendations are followed, the risk of seizures in patients receiving this combination is minimal. With meropenem, a newly registered carbapenem, the safety margin with respect to neurotoxic reactions has been increased compared with imipenem and meropenem can be used at higher doses than imipenem/cilastatin. Since the neurotoxicity of beta-lactam antibacterials seems to be caused by an interaction with gamma-aminobutyric acid (GABA) receptors, other drugs with a similar mechanism of action, such as fluoroquinolone antibacterials, should be used with caution when combined with carbapenems.

  4. Effect of intraperitoneal antimicrobials on the concentration of bacteria, endotoxin, and tumor necrosis factor in abdominal fluid and plasma in rats

    NARCIS (Netherlands)

    Rosman, C; Westerveld, GJ; vanOeveren, W; Kooi, K; Bleichrodt, RP


    The efficacy of intraperitoneal instillation of antimicrobial agents in eliminating the bacterial contaminant in patients with generalized peritonitis remains controversial. We determined the effect of intraperitoneal instillation of taurolidine or imipenem on mortality, and on the concentration of

  5. Development of EUCAST disk diffusion method for susceptibility testing of the Bacteroides fragilis group isolates

    DEFF Research Database (Denmark)

    Nagy, Elisabeth; Justesen, Ulrik Stenz; Eitel, Zsuzsa


    -clavulanic acid, cefoxitin, clindamycin, imipenem, metronidazole, moxifloxacin, piperacillin/tazobactam, tigecycline by agar dilution method previously. The inhibition zones of the same antibiotics including meropenem disc were determined by the disc diffusion on Brucella blood agar supplemented with haemin...

  6. Correlation between carbapenem consumption and antimicrobial resistance rates of Acinetobacter baumannii in a university-affiliated hospital in China. (United States)

    Cao, Jia; Song, Wei; Gu, Bing; Mei, Ya-ning; Tang, Jian-ping; Meng, Ling; Yang, Chang-qing; Wang, Huijuan; Zhou, Hong


    To investigate the correlation between carbapenem consumption and rates of antimicrobial resistance in Acinetobacter baumannii, carbapenem consumption was expressed as defined daily dose based on the World Health Organization (WHO) anatomical therapeutic chemical classification index. Clinical isolates from 2001-2009 were collected and analyzed using WHONET 5.4 software. Results show that the consumption of imipenem/cilastatin, meropenem, and total carbapenem is significantly correlated with imipenem resistance in A baumannii (r = 0.818, P = .007; r = 0.817, P = .007; r = 0.827, P = .006). Furthermore, total carbapenem consumption is significantly correlated with meropenem resistance in A baumannii (r = 0.900, P = .037). In addition, consumption of imipenem/cilastatin, meropenem, and total carbapenem is associated with A baumannii resistance to piperacillin-tazobactam, ceftazidime, cefepime, amikacin, and levofloxacin. These drugs are mainly β-lactams, aminoglycosides, and fluoroquinolones. The imipenem and meropenem resistance rates are significantly correlated with resistance rates to numerous antimicrobial drugs (eg, β-lactams, aminoglycosides, and fluoroquinolones) in A baumannii. Therefore, increased consumption of carbapenem may contribute to the development of resistance in A baumannii to imipenem, meropenem, and other antimicrobial drugs. Cross-resistance possibly occurs among imipenem/cilastatin and meropenem, as well as with β-lactams, aminoglycosides, and fluoroquinolones. © 2012 The Author(s).

  7. Comparison of in Vitro Activity of Doripenem versus Old Carbapenems against Pseudomonas Aeruginosa Clinical Isolates from both CF and Burn Patients

    Directory of Open Access Journals (Sweden)

    Reza Bigverdi


    Full Text Available Purpose: The antimicrobial activity of doripenem in comparison of imipenem, meropenem and ertapenem among Pseudomonas aeruginosa isolated from burn and Cystic Fibrosis (CF patients were determined. Methods: Metallo-β-lactamase (MBL genes in imipenem non susceptible P. aeruginosa isolates were detected using PCR method. The in vitro susceptibilities of doripenem, imipenem, meropenem and ertapenem were determined by Etests. MIC50 and MIC90 for corresponding antibiotics were determined individually in burn and CF isolates. Results: Among isolates which were resistant to imipenem, 16 isolates were positive for the bla IMP gene. All isolates had no bla VIM gene. All MBL producing isolates were excluded. MIC50/MIC90 of doripenem in CF and burn isolates were 0.75/>32 and >32/>32 mg/L respectively. The corresponding values for imipenem in CF and burn isolates were 2/>32 and >32/>32 mg/L, respectively. Conclusion: The susceptibility rate of doripenem is higher than that of imipenem and meropenem among P.aeruginosa isolated from CF patients, whereas, there is no difference between the efficiency of doripenem and old carbapenems in non MBL producing P.aeruginosa isolates in burn patients.

  8. Comparison of in Vitro Activity of Doripenem versus Old Carbapenems against Pseudomonas Aeruginosa Clinical Isolates from both CF and Burn Patients (United States)

    Hojabri, Zoya; Ahangarzadeh Rezaee, Mohammad; Nahaei, Mohammad Reza; Soroush, Mohammad Hossein; Ghojazadeh, Morteza; Pirzadeh, Tahereh; Davodi, Mostafa; Ghazi, Mona; Bigverdi, Reza; Pajand, Omid; Aghazadeh, Mohammad


    Purpose: The antimicrobial activity of doripenem in comparison of imipenem, meropenem and ertapenem among Pseudomonas aeruginosa isolated from burn and Cystic Fibrosis (CF) patients were determined. Methods: Metallo-β-lactamase (MBL) genes in imipenem non susceptible P. aeruginosa isolates were detected using PCR method. The in vitro susceptibilities of doripenem, imipenem, meropenem and ertapenem were determined by Etests. MIC50 and MIC90 for corresponding antibiotics were determined individually in burn and CF isolates. Results: Among isolates which were resistant to imipenem, 16 isolates were positive for the bla IMP gene. All isolates had no bla VIM gene. All MBL producing isolates were excluded. MIC50/MIC90 of doripenem in CF and burn isolates were 0.75/>32 and >32/>32 mg/L respectively. The corresponding values for imipenem in CF and burn isolates were 2/>32 and >32/>32 mg/L, respectively. Conclusion: The susceptibility rate of doripenem is higher than that of imipenem and meropenem among P.aeruginosa isolated from CF patients, whereas, there is no difference between the efficiency of doripenem and old carbapenems in non MBL producing P.aeruginosa isolates in burn patients. PMID:24312823

  9. Intramuscular injection-site complications. (United States)

    Greenblatt, D J; Allen, M D


    Among 26,294 hospitalized medical patients monitored by the Boston Collaborative Drug Surveillance Program, 46% received at least one intramuscular (IM) injection. Drugs for which IM injection was the route of administration in more than 80% of all exposures included penicillin G procaine, mercurial diuretics, cyanocobalamin, streptomycin sulfate, colistimethate sodium, meperidine hydrochloride, cephaloridine, scopolamine hydrobromide, kanamycin sulfate, and iron dextran injection. Local complications of IM injection were reported in a total of only 48 patients (0.4% of all IM recipients). Local complications were most commonly associated with IM injection of cephalothin sodium. Clinically important local complications are uncommonly associated with IM injections in general. However, certain drugs, eg, cephalothin, produce injection-site complications with relatively high frequency; the clinical role of IM injection of such drugs should be reevaluated.

  10. Beta-lactamase activity in Shigella sonnei. (United States)

    Prince, A; Neu, H C


    The basis of ampicillin resistance in Shigella sonnei was analyzed for a number of isolates. Most isolates that were resistant to ampicillin and cephalothin failed to transfer resistance. Isolates resistant to cephalothin and ampicillin were inhibited by mecillinam, cefamandole, and cefoxitin. Six strains were selected for study. These differed on the basis of inhibition by 10 beta-lactam antibiotics and on differences in beta-lactamase activity. There was no correlation between the inhibitory concentration of antibiotic and the amount of antibiotic hydrolyzed. Use of sodium chloride and cloxacillin inhibition and acrylamide electrophoresis demonstrated that ampicillin resistance in Shigella is mediated by a number of different beta-lactamases. Organisms can contain more than one type of beta-lactamase.

  11. Comparative virulence genotyping and antimicrobial susceptibility profiling of environmental and clinical Salmonella enterica from Cochin, India

    Digital Repository Service at National Institute of Oceanography (India)

    Parvathi, A.; Vijayan, J.; Murali, G.; Chandran, P.

    - typhoidal Salmonella enterica to the disease burden is unknown. The evolution of virulence and antimicrobial resistance capabilities of pathogenic bacteria takes place by horizontal acquisition of genes and the aquatic environment is arguably an ideal...%) to cephalothin and cephalexin, 14 (23.5%) to nalidixic acid and 9 (15%) were resistant to chloramphenicol. A study by the Centre for Disease Control and Prevention reported emergence of Newport-MDRAmpC strains resistant ampicillin, chloramphenicol...

  12. Changing trend of empirical antibiotic regimen: experience of two studies at different periods in a neonatal intensive care unit in Tehran, Iran. (United States)

    Marzban, Asghar; Samaee, Hadi; Mosavinasab, Noredien


    Bacterial sepsis is one of the most common causes of mortality and morbidity in neonates. It has been recognized a gradual change in spectrum of organisms responsible for neonatal sepsis. In this study we have evaluated changing trend of incidence and antibiotic susceptibility in neonatal late - onset sepsis (LOS) in 2-periods. This study is based on results of blood culture in neonatal late-onset sepsis, in 2--periods study throughout 12 - years. Neonatal LOS was defined as clinical signs suggestive of infection with a positive blood culture (B/C) after 72 hrs of birth. During first study (period: 1990-1992), the most common bacteremia in LOS was staphylococcus aureus (staph aureus) (34%). Overall gram- negative bacteria (GNB) were the predominant organism (66%). It was shown that 60% of GNB were resisted to gentamicin and 3% to amikacin, while in case of gram-positive bacteria (GPB); about 95% were resisted to ampicillin and 28% to cephalothin. In the second study (period: 2004-2007), the vast majority (56.6%) of septic cases were caused by GNB. The most common cause of late- onset sepsis was klebsiela p. (31%). The GPB were resistant to cephalothin (90%). There has been a dramatic increase resistance to cephalothin and aminoglycosides and 3rd -generation cephalosporins. The combination of cephalothin plus amikacin in suspected LOS was no longer the effective therapeutic regimen in our neonatal intensive care unit (NICU). Now, it seems the best choice for empiric antibiotic regimen in suspected LOS is the combination vancomycin plus amikacin. Constant surveillance is important to guide empirical antibiotic therapy and changes in trends.

  13. Changing Trend of Empirical Antibiotic Regimen: Experience of Two Studies at Different Periods in a Neonatal Intensive Care Unit in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    Asghar Marzban


    Full Text Available "nBacterial sepsis is one of the most common causes of mortality and morbidity in neonates. It has been recognized a gradual change in spectrum of organisms responsible for neonatal sepsis. In this study we have evaluated changing trend of incidence and antibiotic susceptibility in neonatal late - onset sepsis (LOS in 2-periods. This study is based on results of blood culture in neonatal late-onset sepsis, in 2--periods study throughout 12 - years. Neonatal LOS was defined as clinical signs suggestive of infection with a positive blood culture (B/C after 72 hrs of birth. During first study (period: 1990-1992, the most common bacteremia in LOS was staphylococcus aureus (staph aureus (34%. Overall gram- negative bacteria (GNB were the predominant organism (66%. It was shown that 60% of GNB were resisted to gentamicin and 3% to amikacin, while in case of gram-positive bacteria (GPB; about 95% were resisted to ampicillin and 28% to cephalothin. In the second study (period: 2004-2007, the vast majority (56.6% of septic cases were caused by GNB. The most common cause of late- onset sepsis was klebsiela p. (31%. The GPB were resistant to cephalothin (90%. There has been a dramatic increase resistance to cephalothin and aminoglycosides and 3rd -generation cephalosporins. The combination of cephalothin plus amikacin in suspected LOS was no longer the effective therapeutic regimen in our neonatal intensive care unit (NICU. Now, it seems the best choice for empiric antibiotic regimen in suspected LOS is the combination vancomycin plus amikacin. Constant surveillance is important to guide empirical antibiotic therapy and changes in trends.

  14. Changing Trend of Empirical Antibiotic Regimen: Experience of Two Studies at Different Periods in a Neonatal Intensive Care Unit in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    Asghar Marzban


    Full Text Available Bacterial sepsis is one of the most common causes of mortality and morbidity in neonates. It has been recognized a gradual change in spectrum of organisms responsible for neonatal sepsis. In this study we have evaluated changing trend of incidence and antibiotic susceptibility in neonatal late - onset sepsis (LOS in 2-periods. This study is based on results of blood culture in neonatal late-onset sepsis, in 2--periods study throughout 12 - years. Neonatal LOS was defined as clinical signs suggestive of infection with a positive blood culture (B/C after 72 hrs of birth. During first study (period: 1990-1992, the most common bacteremia in LOS was staphylococcus aureus (staph aureus (34%. Overall gram- negative bacteria (GNB were the predominant organism (66%. It was shown that 60% of GNB were resisted to gentamicin and 3% to amikacin, while in case of gram-positive bacteria (GPB; about 95% were resisted to ampicillin and 28% to cephalothin. In the second study (period: 2004-2007, the vast majority (56.6% of septic cases were caused by GNB. The most common cause of late- onset sepsis was klebsiela p. (31%. The GPB were resistant to cephalothin (90%. There has been a dramatic increase resistance to cephalothin and aminoglycosides and 3rd -generation cephalosporins. The combination of cephalothin plus amikacin in suspected LOS was no longer the effective therapeutic regimen in our neonatal intensive care unit (NICU. Now, it seems the best choice for empiric antibiotic regimen in suspected LOS is the combination vancomycin plus amikacin. Constant surveillance is important to guide empirical antibiotic therapy and changes in trends.

  15. Sch 29482, laboratory evaluation of a new penem antibiotic


    Kayser, F H; KUHN, I.


    The antibacterial activity of a new penem antibiotic, Sch 29482 (SCH), was examined in comparison with appropriate cephalosporins and penicillins. The drug inhibited penicillinase-positive and negative staphylococci equally well, being 2-5 times more active than cephalothin or cefamandole and 10-20 times more active than methicillin. Staphylococci resistant to methicillin were susceptible to SCH in agar dilution tests. Staphylococci tolerant to methicillin were also tolerant to SCH. Streptoco...

  16. Sources of diversity of carbapenem resistance levels in Klebsiella pneumoniae carrying blaVIM-1. (United States)

    Loli, A; Tzouvelekis, L S; Tzelepi, E; Carattoli, A; Vatopoulos, A C; Tassios, P T; Miriagou, V


    To elucidate the mechanisms responsible for the diversity of beta-lactam resistance phenotypes among isolates of a VIM-1-producing Klebsiella pneumoniae (VPKP) strain that is endemic in Greek hospitals. Five VPKP clinical isolates were studied. MICs of beta-lactams were determined by agar dilution. PFGE of XbaI-digested genomic DNA was used for typing. Profiles of outer membrane proteins (OMPs) were determined by SDS-PAGE. Selected isolates were transformed with a plasmid encoding the Omp36K porin. beta-Lactamase activities were analysed by IEF and imipenem hydrolysis was assessed by spectrophotometry. VIM-1-encoding, self-transmissible plasmids were characterized by replicon typing, RFLP and hybridization with bla(VIM)- and IS26-specific probes. Characterization of integrons was performed by PCR, cloning and sequencing. Isolates exhibited highly similar PFGE patterns. Imipenem MICs were 2, 4, 16, 32 and 64 mg/L. The isolate with the highest imipenem MIC (Vipm-64) lacked a 36 kDa OMP. Expression of a cloned OmpK36 in this isolate reduced the imipenem MIC to susceptibility levels. Imipenem-hydrolysing activity was significantly higher in Vipm-16 as compared with the other isolates that expressed similar amounts of VIM-1. All isolates transferred beta-lactam resistance to Escherichia coli through conjugative, IncN plasmids that exhibited differences in the RFLP and hybridization patterns with bla(VIM)- and IS26-specific probes. The Vipm-16 plasmid, mediating the higher imipenem MICs among transconjugants, carried two copies of bla(VIM-1). Cloning and sequencing showed In-e541-like integrons truncated at the 5'CS by insertion of IS26 elements at two different positions. A VIM-1-producing strain of K. pneumoniae has evolved through OMP alterations and rearrangements in the bla(VIM-1)-carrying plasmid probably mediated by IS26, generating isolates with imipenem MICs ranging from susceptibility to resistance.

  17. Isolation of antimicrobial-resistant Escherichia coli from retail meats purchased in Greater Washington, DC, USA. (United States)

    Schroeder, Carl M; White, David G; Ge, Beilei; Zhang, Yifan; McDermott, Patrick F; Ayers, Sherry; Zhao, Shaohua; Meng, Jianghong


    Four hundred and seventy-two generic Escherichia coli isolates were recovered from ground and whole retail beef, chicken, pork, and turkey obtained from Greater Washington, DC, USA during the years 1998 to 2000. Many of the isolates displayed resistance to tetracycline (59%), sulfamethoxazole (45%), streptomycin (44%), cephalothin (38%) and ampicillin (35%). Resistance was also observed, but to a lesser extent, to gentamicin (12%), nalidixic acid (8%), chloramphenicol (6%), ceftiofur (4%) and ceftriaxone (1%). Sixteen percent of the isolates displayed resistance to one antimicrobial, followed by 23% to two, 23% to three, 12% to four, 7% to five, 3% to six, 2% to seven and 2% to eight. Three E. coli isolates were shown to possess Shiga toxin genes (stx2) via PCR; all were O non-typeable and were recovered from ground beef samples purchased on the same day at the same supermarket. One of the Shiga toxin-producing E. coli (STEC) isolates was susceptible to each of the antimicrobials tested, whereas one displayed resistance to cephalothin and sulfamethoxazole, and one displayed resistance to ampicillin, cephalothin, gentamicin, streptomycin, sulfamethoxazole and tetracycline. Findings from this study indicate that retail raw meats may often be contaminated with antimicrobial-resistant E. coli.

  18. R factor-mediated and chromosomal resistance to ampicillin in Escherichia coli. (United States)

    Roupas, A; Pitton, J S


    Sixty-four ampicillin-resistant strains of Escherichia coli were studied. Six characters were examined: (i) resistance to ampicillin, cephalothin, and carbenicillin, (ii) synergy between ampicillin and cloxacillin, (iii) level of beta-lactamase activity after osmotic shock, (iv) transferability of ampicillin resistance, (v) immunological characterization of the enzyme, and (vi) determination of substrate profiles. One class of strains was found in which synthesis of beta-lactamase is inferred to be plasmid mediated; these strains are highly resistant to ampicillin and carbenicillin, sensitive to cephalothin, do not show synergism between ampicillin and cloxacillin, and reveal a high enzymatic activity after osmotic shock. A second class is formed by strains for which beta-lactamase synthesis is inferred to be chromosomal; these strains present a low resistance level to ampicillin, are sensitive to carbenicillin and resistant to cephalothin, show a synergism between ampicillin and cloxacillin, and reveal a very low enzymatic activity after osmotic shock. These characters may be used to differentiate periplasmic and cell-bound beta-lactamases.

  19. Fabric phase sorptive extraction of selected penicillin antibiotic residues from intact milk followed by high performance liquid chromatography with diode array detection. (United States)

    Samanidou, Victoria; Michaelidou, Katia; Kabir, Abuzar; Furton, Kenneth G


    Fabric phase sorptive extraction (FPSE), a novel sorbent-based microextraction method, was evaluated as a simple and rapid strategy for the extraction of four penicillin antibiotic residues (benzylpenicillin, cloxacillin, dicloxacillin and oxacillin) from cows' milk, without prior protein precipitation. Time-consuming solvent evaporation and reconstitution steps were eliminated successfully from the sample preparation workflow. FPSE utilizes a flexible fabric substrate, chemically coated with sol-gel derived, highly efficient, organic-inorganic hybrid sorbent as the extraction medium. Herein short-chain poly(ethylene glycol) provided optimum extraction sensitivity for the selected penicillins, which were analysed using an RP-HPLC method, validated according to the European Decision 657/2002/EC. The limit of quantitation was 10μg/kg for benzylpenicillin, 20μg/kg for cloxacillin, 25μg/kg dicloxacillin and 30μg/kg oxacillin. These are a similar order of magnitude with those reported in the literature and (with the exception of benzylpenicillin) are less than the maximum residue limits (MRL) set by European legislation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. [Treatment of mastitis in general practice]. (United States)

    Nordeng, Hedvig; Tufte, Elisabeth; Nylander, Gro


    This article presents an update on causes and management of mastitis in general practice. Published articles on the causes and management of mastitis were identified by Medline and Embase searches, and reviewed. In addition, clinical experience from The National Breast-Feeding Centre in Norway is included. Most studies report an incidence of mastitis of less than 20% though major methodological limitations make estimates difficult. Common symptoms of mastitis is a swollen, red, hot and painful breast, and systemic symptoms as fever occur frequently. Mastitis may be inflammatory or caused by microorganisms, and often secondary to milk stasis. Effective milk removal is a most essential part of the treatment and may make antibiotics superfluous. In most cases bacterial mastitis is caused by Staphylococcus aureus resistant to beta-lactamase sensitive antibiotics. Culture of the milk is necessary to determine the infecting organism and its antibiotic sensitivity. When antibiotics are warranted, dicloxacillin or cloxacillin are suggested as first-line drugs. The transfer of dicloxacillin/cloxacillin to breast milk is minimal. In most cases women with mastitis can continue to breast-feed also from the affected breast during treatment.

  1. Drug-laboratory interaction between beta-lactam antibiotics and the galactomannan antigen test used to detect mould infections. (United States)

    Otting, Kristin A; Stover, Kayla R; Cleary, John D


    Several studies have demonstrated that piperacillin/tazobactam produces a false-positive result for the galactomannan antigen test. However, the most recent literature has demonstrated that this interaction is no longer a concern. There is little information regarding the drug-laboratory interaction with the generics of piperacillin/tazobactam or other broad-spectrum beta-lactams, such as ceftaroline, doripenem, imipenem/cilastatin, and meropenem. The purpose of this study was to determine if a drug-laboratory interaction exists with these antibiotics. Tests showed that one lot of imipenem/cilastatin by Hospira Healthcare India Private Limited produced a false-positive result for the galactomannan antigen test. All other medications tested, including piperacillin/tazobactam from seven manufacturers and imipenem/cilastatin by Hospira Inc., did not produce positive results. Since the reason for this drug-laboratory interaction with imipenem/cilastatin is unknown, more studies are needed to further investigate this interaction. Providers also should be educated of these findings: no drug-laboratory interaction with piperacillin/tazobactam and a possible drug-laboratory interaction with imipenem/cilastatin (Hospira Healthcare India Private Limited). Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

  2. [Activity of doripenem against Pseudomonas spp. and Acinetobacter spp. rods]. (United States)

    Bogiel, Tomasz; Deptuła, Aleksander; Gospodarek, Eugenia


    Doripenem, the newest carbapenem was approved in 2008 by the European Medicines Agency for the treatment of complicated intra-abdominal infections and complicated urinary tract infections. Its spectrum of activity is similar to that of meropenem and imipenem/cilastatin. The aim of this study was to compare in vitro activity of doripenem against nonfermentative Gram-negative rods. A total of 235 strains of Pseudomonas spp. (74.9%) and Acinetobacter spp. (25.1%) were included into the study. Strains were isolated in The Department of Clinical Microbiology of the University Hospital No 1 in Bydgoszcz and identified using ID GN tests (bioMérieux). To determine susceptibility to doripenem and other carbapenems disc-diffusion method was applied. Percentage of doripenem resistant strains reached 28.4% and 39.0% for Pseudomonas spp. and Acinetobacter spp, respectively. All doripenem sensitive or intermediate Acinetobacter spp. strains were simultaneously sensitive to imipenem and meropenem. Activity of imipenem and meropenem among doripenem resistant Acinetobacter spp. were represented by 60.9% and 56.5% strains, respectively. Activity of imipenem and meropenem among doripenem resistant Pseudomonas spp. strains were represented by 12.0% and 18.0%, respectively. Occurence of one doripenem sensitive Pseudomonas spp. strain simultaneously resistant to imipenem and meropenem was observed.

  3. [Antibiotic susceptibility patterns of bacteria isolated from keratitis and intraocular infections at Fundación Oftalmológica de Santander (FOSCAL), Floridablanca, Colombia]. (United States)

    Galvis, Virgilio; Tello, Alejandro; Guerra, Alfredo; Acuña, María Fernanda; Villarreal, Donaldo


    Bacterial resistance is critical for the selection of antibiotics in the treatment of infections, so it is vital to know its current status in our geographical area. To determine in vitro antibiotic susceptibility of bacterial isolates obtained from keratitis and intraocular infections. A retrospective study of microbiological tests in Fundación Oftalmológica de Santander (FOSCAL) was carried out between June, 2011, and January, 2012. A total of 92 samples were examined and 110 bacteria, 27 fungi and 12 free-living amoebae were identified. Polymicrobial infections constituted 50% of the total; 1.1%, 0%, 1.1%, 16.9%, 29.3% and 85% of Gram-positive bacteria were resistant to imipenem, moxifloxacin, gatifloxacin, levofloxacin, ciprofloxacin and tobramycin, respectively, while 0%, 8.3%, 0%, 0%, 18.2% and 27.3% of Gram-negative bacteria were resistant to imipenem, moxifloxacin, gatifloxacin, levofloxacin, ciprofloxacin and tobramycin, respectively. For methicillin-resistant coagulase-positive staphylococci, resistance percentages to imipenem, moxifloxacin, gatifloxacin, levofloxacin, ciprofloxacin and tobramycin were 0%, 0%, 0%, 7%, 17% and 100%, respectively. For methicillin-resistant coagulase-negative staphylococci, resistance percentages to imipenem, moxifloxacin, gatifloxacin, levofloxacin, ciprofloxacin and tobramycin were 3%, 0%, 0%, 24%, 44% and 100%, respectively. Overall bacterial resistance to imipenem, moxifloxacin, gatifloxacin, levofloxacin, ciprofloxacin and tobramycin, for both Gram-positive and Gram-negative, was 1%, 1%, 1%, 15.1%, 28% and 64.5%, respectively. The levels of bacterial resistance to imipenem, moxifloxacin and gatifloxacin were lower than for levofloxacin, ciprofloxacin and tobramycin. The levels of resistance to tobramycin were very high, which calls into question its usefulness in this region of our country.

  4. Comparison of disk diffusion, Etest and VITEK2 for detection of carbapenemase-producing Klebsiella pneumoniae with the EUCAST and CLSI breakpoint systems. (United States)

    Vading, M; Samuelsen, Ø; Haldorsen, B; Sundsfjord, A S; Giske, C G


    The aim of this study was to compare CLSI and EUCAST MIC and disk diffusion carbapenem breakpoints for the detection of carbapenemase-producing Klebsiella pneumoniae. K. pneumoniae strains with known KPC (n = 31) or VIM (n = 20) carbapenemases were characterized by disk diffusion (Oxoid) and Etest (bioMérieux) vs. imipenem, meropenem and ertapenem, and with VITEK2 (bioMérieux, five different cards). Extended-spectrum β-lactamase (ESBL) testing was performed with VITEK2 (bioMérieux), ESBL combination disks (Becton Dickinson) and the ESBL Etest (bioMérieux). With CLSI and EUCAST MIC breakpoints, respectively, 11 and seven of the strains were susceptible to imipenem, 12 and eight to meropenem, and seven and none to ertapenem. The EUCAST epidemiological cut-off (ECOFF) values for meropenem and ertapenem identified all carbapenemase producers, whereas the imipenem ECOFF failed in five strains. All carbapenemase producers were detected with EUCAST disk diffusion breakpoints for ertapenem and meropenem, and four strains were susceptible to imipenem. CLSI disk diffusion breakpoints characterized 18 (imipenem), 14 (meropenem) and three (ertapenem) isolates as susceptible. When cards with a single carbapenem were used, detection failures with VITEK2 were four for imipenem, none for meropenem and one for ertapenem. Cards containing all three carbapenems had one to two failures. With ESBL combination disks, 21/31 KPC producers and 2/20 VIM producers were positive. With VITEK2, no VIM producers and between none and seven KPC producers were ESBL-positive. All carbapenemase producers were detected with the meropenem MIC ECOFF, or the clinical EUCAST breakpoint for ertapenem. EUCAST disk diffusion breakpoints for meropenem and ertapenem detected all carbapenemase producers. VITEK2 had between none and four failures in detecting carbapenemase producers, depending on the antibiotic card. © 2010 The Authors. Clinical Microbiology and Infection © 2010 European Society

  5. Susceptibilidade a antimicrobianos de bactérias isoladas de otite externa em cães Antimicrobial sensitivity of bacteria from otitis externa in dogs

    Directory of Open Access Journals (Sweden)

    L.C. Oliveira


    Full Text Available The occurrence of canine externa otitis in Fortaleza-Ceará is reported. About 91.5% of the animals with clinical signs were positive to bacterial culture. Among all infections, 49.5% were mixed infections and the most common pathogens were Staphylococcus spp coagulase negative or positive and Pseudomonas aeruginosa. The most effective antimicrobials for Staphylococcus coagulase negative were: the quinolones, the aminoglicoside netilmycin and the beta-lactams, excepted ampicillin, penicillin and oxacilin; for Staphylococcus coagulase positive were: cefotoxin, amoxicillin + clavulanic acid, imipenem, netilmycin and cephatoxin; for Pseudomonas aeruginosa were: ciprofloxacin, tobramycin and imipenem.

  6. Discovery of MK-7655, a β-lactamase inhibitor for combination with Primaxin®

    Energy Technology Data Exchange (ETDEWEB)

    Blizzard, Timothy A.; Chen, Helen; Kim, Seongkon; Wu, Jane; Bodner, Rena; Gude, Candido; Imbriglio, Jason; Young, Katherine; Park, Young-Whan; Ogawa, Aimie; Raghoobar, Susan; Hairston, Nichelle; Painter, Ronald E.; Wisniewski, Doug; Scapin, Giovanna; Fitzgerald, Paula; Sharma, Nandini; Lu, Jun; Ha, Sookhee; Hermes, Jeff; Hammond, Milton L. (Merck)


    β-Lactamase inhibitors with a bicyclic urea core and a variety of heterocyclic side chains were prepared and evaluated as potential partners for combination with imipenem to overcome class A and C β-lactamase mediated antibiotic resistance. The piperidine analog 3 (MK-7655) inhibited both class A and C β-lactamases in vitro. It effectively restored imipenem’s activity against imipenem-resistant Pseudomonas and Klebsiella strains at clinically achievable concentrations. A combination of MK-7655 and Primaxin® is currently in phase II clinical trials for the treatment of Gram-negative bacterial infections.

  7. Susceptibility of Rhodobacter sphaeroides to beta-lactam antibiotics: isolation and characterization of a periplasmic beta-lactamase (cephalosporinase). (United States)

    Baumann, M; Simon, H; Schneider, K H; Danneel, H J; Küster, U; Giffhorn, F


    Thirteen strains of the gram-negative, facultative phototrophic bacterium Rhodobacter sphaeroides were examined fro susceptibility to beta-lactam antibiotics. All strains were sensitive to the semisynthetic penicillins ampicillin, carbenicillin, oxacillin, cloxacillin, and methicillin, but 10 of the 13 strains were resistant to penicillin G, as well as a number of cephalosporins, such as cephalothin, cephapirin, and cephalosporin C. A beta-lactamase (EC with strong cephalosporinase activity was detected in all of the resistant strains of R. sphaeroides. With strain Y-1 as a model, it was shown that the beta-lactamase was inducible by penicillin G, cephalosporin C, cephalothin, and to some minor extent, cephapirin. The beta-lactamase was located in the periplasmic space, from which it could be extracted by osmotic shock disruption. By using this fraction, the beta-lactamase was purified 34-fold to homogeneity by steps involving batch adsorption to and elution from DEAE-Sephadex A50, chromatography on Q-Sepharose, and preparative polyacrylamide gel electrophoresis. The molecular masses of the native and denatured enzymes were determined to be 38.5 kilodaltons by gel filtration and 40.5 kilodaltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively, indicating a monomeric structure. The isoelectric point was estimated to be at pH 4.3. In Tris hydrochloride buffer, optimum enzyme activity was measured at pH 8.5. The beta-lactamase showed high activity in the presence of the substrates cephalothin, cephapirin, cephalosporin C, and penicillin G, for which the apparent Km values were 144, 100, 65, and 110 microM, respectively. Cephalexin, cepharidine, and cephaloridine were poor substrates. The beta-lactamase was strongly inhibited by cloxacillin and oxacillin but only slightly inhibited by phenylmethylsulfonyl fluoride or thiol reagents such as iodoacetate and p-chloromercuribenzoate.

  8. Desarrollo de la formulación de dicloxacilina, suspensión oral 125 mg

    Directory of Open Access Journals (Sweden)

    María de los Ángeles Lorenzo


    Full Text Available Se describe el desarrollo de la formulación de dicloxacilina sódica, suspensión oral 125 mg para uso pediátrico mediante la técnica de elaboración del granulado por la vía humeda. Se logró un producto estable por el tiempo de vida útil de 24 meses y después de reconstituido 10 d.It is described the development of the sodium dicloxacillin formulation, oral suspension for pediatric use by using the technique of elaboration of the granulate by wet way. It was obtained a stable product with a useful life of 24 months, and of 10 days after being reconstituted.


    Directory of Open Access Journals (Sweden)

    Neli M. Ermenlieva


    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA are bacteria, responsible for severe and hard-to-manage infections in human. They are resistant to beta-lactam antibiotics – penicillins (methicillin, dicloxacillin, nafcillin, and oxacillin, cephalosporins and carbapenems, but can also be resistant to the new-generation MRSA-active cephalosporins (such as ceftaroline or other groups of antibiotics, including aminoglycosides, macrolides, clindamycin, amphenicols, quinolones and tetracyclines. MRSA bacteria are pandemic and are often isolated in medical practice and nosocomial infections. The MRSA detection is a challenge to any clinical microbiology laboratory and demands implementation of strict protocols for active screening. While more expensive molecular techniques have the potential of offering highly sensitive and rapid results, the cultural methods require longer time but can achieve a comparable sensitivity for lower price.

  10. A novel hybrid metal-organic framework-polymeric monolith for solid-phase microextraction. (United States)

    Lin, Chen-Lan; Lirio, Stephen; Chen, Ya-Ting; Lin, Chia-Her; Huang, Hsi-Ya


    This study describes the fabrication of a novel hybrid metal-organic framework- organic polymer (MOF-polymer) for use as a stationary phase in fritless solid-phase microextraction (SPME) for validating analytical methods. The MOF-polymer was prepared by using ethylene dimethacrylate (EDMA), butyl methacrylate (BMA), and an imidazolium-based ionic liquid as porogenic solvent followed by microwave-assisted polymerization with the addition of 25 % MOF. This novel hybrid MOF-polymer was used to extract penicillin (penicillin G, penicillin V, oxacillin, cloxacillin, nafcillin, dicloxacillin) under different conditions. Quantitative analysis of the extracted penicillin samples using the MOF-organic polymer for SPME was conducted by using capillary electrochromatography (CEC) coupled with UV analysis. The penicillin recovery was 63-96.2 % with high reproducibility, sensitivity, and reusability. The extraction time with the proposed fabricated SPME was only 34 min. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. A reversed phase liquid chromatographic method for the simultaneous determination of several common penicillins in human serum. (United States)

    Mendez-Alvarez, E; Soto-Otero, R; Sierra-Paredes, G; Aguilar-Veiga, E; Galan-Valiente, J; Sierra-Marcuño, G


    A rapid and sensitive high performance liquid chromatographic method is described for the simultaneous determination of benzylpenicillin, ampicillin, phenoxymethylpenicillin, cloxacillin, dicloxacillin and nafcillin in small samples of human serum. The chromatographic system involves the use of a Spherisorb ODS reversed phase column and a gradient elution with 1 mM ammonium acetate buffer/acetonitrile (from 90:10 to 75:25 in 15 min). Detection and quantification are monitored by UV absorption at 208 nm. The compounds are extracted with dichloromethane, using tetrabutylammonium hydrogen sulfate neutralized with sodium hydroxide and buffered with borate as an ion pairing reagent; beta-hydroxyethyltheophylline is added as an internal standard. Our results show that the method is accurate and reproducible, allowing quantification of serum levels of assayed penicillins (0.5-50 micrograms/mL) without interference from other drugs commonly used in therapy. Recoveries were generally greater than 79.4%.

  12. Pyrocatechol violet in pharmaceutical analysis. Part I. A spectrophotometric method for the determination of some beta-lactam antibiotics in pure and in pharmaceutical dosage forms. (United States)

    Amin, A S


    A fairly sensitive, simple and rapid spectrophotometric method for the determination of some beta-lactam antibiotics, namely ampicillin (Amp), amoxycillin (Amox), 6-aminopenicillanic acid (6APA), cloxacillin (Clox), dicloxacillin (Diclox) and flucloxacillin sodium (Fluclox) in bulk samples and in pharmaceutical dosage forms is described. The proposed method involves the use of pyrocatechol violet as a chromogenic reagent. These drugs produce a reddish brown coloured ion pair with absorption maximum at 604, 641, 645, 604, 649 and 641 nm for Amp, Amox, 6APA, Clox, Diclox and Flucolx, respectively. The colours produced obey Beer's law and are suitable for the quantitative determination of the named compounds. The optimization of different experimental conditions is described. The molar ratio of the ion pairs was established and a proposal for the reaction pathway is given. The procedure described was applied successfully to determine the examined drugs in dosage forms and the results obtained were comparable to those obtained with the official methods.

  13. Analysis of different beta-lactams antibiotics in pharmaceutical preparations using micellar electrokinetic capillary chromatography. (United States)

    Pérez, M I Bailón; Rodríguez, L Cuadros; Cruces-Blanco, C


    The potential of micellar electrokinetic capillary chromatography (MEKC) for analyzing nine beta-lactams antibiotics (cloxacillin, dicloxacillin, oxacillin, penicillin G, penicillin V, ampicillin, nafcillin, piperacillin, amoxicillin) in different pharmaceutical preparations, have been demonstrated. An experimental design strategy has been applied to optimize the main variables: pH and buffer concentration, concentration of the micellar medium, separation voltage and capillary temperature. Borate buffer (26mM) at pH 8.5 containing 100mM sodium dodecyl sulphate (SDS) was used as the background electrolyte. The method was validated. Linearity, limit of detection and quantitation and precision were established for each compound. The analysis of some of the beta-lactams in Orbenin capsules, Britapen tables and in Veterin-Micipen injectable, all used in human and veterinary medicine, have demonstrated the applicability of these technique for quality control in the pharmaceutical industry.

  14. Prevalence of multi-drug resistance (MDR) Pseudomonas ...

    African Journals Online (AJOL)

    Prevalence of multi-drug resistance (MDR) Pseudomonas aeruginosa isolates in surgical units of Ahmadu Bello University teaching Hospital, Zaria, Nigeria: An ... The antibiotic susceptibility of isolates and a standard strain to ceftazidime, amikacin, gentamicin, imipenem, ciprofloxacin and perfloxacin was determined by the ...

  15. Molecular characterization of carbapenem-resistant Acinetobacter ...

    African Journals Online (AJOL)

    Purpose: To survey the molecular characteristics of imipenem-resistant Acinetobacter baumannii obtained from pediatric burns patients in a teaching hospital in Tehran, Iran. Methods: Over a 10-month period, 73 non-duplicate A. baumannii strains were collected from pediatric burns patients admitted to Motahari Burn and ...

  16. Multi-drug resistant Staphylococcus aureus isolated from emergency ...

    African Journals Online (AJOL)

    The prevalence of resistance against methicillin, oxacillin and azithromycin were 44.4, 33.3 and 33.3 %, respectively. There was no pattern of resistance against imipenem. Conclusion: Efficient disinfection of surfaces, beds, trolleys and surgical instruments should be performed periodically to reduce colonization of resistant ...

  17. Antibiotic Activity Assessment of Bacterial Strains Isolated from Urine ...

    African Journals Online (AJOL)

    The rate of amoxicillin and trimethoprim-sulfamethoxazole resistance to Enterobacteriaceae implies that another antibiotic should be used for empirical treatment and that there is a need for new generic drugs in Rwanda. Imipenem could be included as a reasonable alternative for the therapy of UTIs in Rwanda. Keywords: ...

  18. In vitro activity of antimicrobial combinations against multidrug-resistant Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Denissani Aparecida Ferrari dos Santos Lima


    Full Text Available Introduction Pseudomonas aeruginosa isolates related to nosocomial infections are often resistant to multiple antibacterial agents. In this study, antimicrobial combinations were evaluated to detect in vitro synergy against clinical isolates of P. aeruginosa. Methods Four clinical P. aeruginosa isolates were selected at random among other isolates from inpatients treated at the public University hospital in Ribeirão Preto, SP, Brazil. Two isolates were susceptible to imipenem (IPM-S and several other antimicrobials, while the other two isolates were imipenem and multidrug resistant (IPM-R. The checkerboard method was used to assess the interactions between antimicrobials. Results Combinations of imipenem or other anti-Pseudomonas drugs with complementary antibiotics, such as aminoglycosides, fosfomycin and rifampin, reached synergy rates of 20.8%, 50%, 62.5% and 50% for the two IPM-S and two IPM-R Pseudomonas isolates, respectively. Imipenem, piperacillin-tazobactam and ceftazidime yielded a greater synergy rate than cefepime or ciprofloxacin. Synergist combinations were more commonly observed when the complementary drug was tobramycin (65% or fosfomycin (57%. Conclusions Some antibacterial combinations led to significant reductions of the minimum inhibitory concentrations of both drugs, suggesting that they could be clinically applied to control infections caused by multidrug-resistant P. aeruginosa.


    African Journals Online (AJOL)


    ICU admission, longer ICU stay, exposure to emergent surgery, the presence of central venous catheter and previous carbapenem use were significant risk factors for IRAB infection. Rationale use of carbapenems in ICUs should be considered. Key words: Imipenem-resistant, Acinetobacter baumannii, Intensive care units.

  20. Erythromycin inhibits Pseudomonas aeruginosa-induced tumour necrosis factor-alpha production in human whole blood

    NARCIS (Netherlands)

    Schultz, M. J.; Speelman, P.; van der Poll, T.


    Erythromycin has been shown to be beneficial for panbronchiolitis, a disorder linked to infection with Pseudomonas aeruginosa. Erythromycin, but not the anti-Pseudomonas antibiotics imipenem, ceftazidime, gentamicin and ciprofloxacin, caused a dose-dependent decrease in the production of tumour

  1. Induction of beta-lactamase production in Pseudomonas aeruginosa biofilm

    DEFF Research Database (Denmark)

    Giwercman, B; Jensen, E T; Høiby, N


    Imipenem induced high levels of beta-lactamase production in Pseudomonas aeruginosa biofilms. Piperacillin also induced beta-lactamase production in these biofilms but to a lesser degree. The combination of beta-lactamase production with other protective properties of the biofilm mode of growth...

  2. Occurrence and characterization of multidrugresistant new delhi metallo-β-lactamase-1- producing bacteria isolated between 2003 and 2010 in Bangladesh

    NARCIS (Netherlands)

    M.S. Islam (Mohammad S.); M.N. Huq (Mohammed); A. Nabi (Ashikun); P.K. Talukdar (Prabhat Kumar); D. Ahmed (Dilruba); K.A. Talukder (Kaisar); A. Cravioto (Alejandro); H.P. Endtz (Hubert)


    textabstractThe purpose of this study was to screen for reduced susceptibility against imipenem and the presence of the New Delhi metallo-β-lactamase-1 (NDM-1) gene in a collection of Enterobacteriaceae (Escherichia coli, Shigella spp. and Klebsiella pneumoniae) from different surveillance studies

  3. Detection of KPC-2 in a Clinical Isolate of Proteus mirabilis and First Reported Description of Carbapenemase Resistance Caused by a KPC Beta-Lactamase in P. mirabilis (United States)

    An isolate of Proteus mirabilis recovered from bacterial cultures was shown to be resistant to imipenem, meropenem, and ertapenem by disk diffusion susceptibility testing. Amplification of whole cell and/or plasmid DNA recovered from the isolate using primers specific for the blaKPC carbapenemase g...

  4. One year prevalence of critically ill burn wound bacterial infections in surgical ICU in Egypt: Retrospective study

    Directory of Open Access Journals (Sweden)

    Hossam Mohamed


    Results: The main finding of the current study described herein was the percent of isolates from burn wound (60%. The most common organism was pseudomonas (49%. Multidrug resistant gram negative organisms represent about 60% of the isolates. Pattern of antibiotic sensitivity was 84% for colistin, 39% for amikacin and 35% for imipenem. The mortalities in our study were 80%.

  5. Molecular characteristics of Multidrug Resistant Acinetobacter baumannii Isolates from US soldiers from Iraq at the National Naval Medical Center (United States)

    Background: Infections with A. baumannii-calcoaceticus complex (ABC) have complicated the care of combat casualties, and the spread and global dissemination of imipenem resistant (IR) clones of ABC have been reported in recent years. However, the epidemiological features of the IR-ABCs in military t...

  6. neonatal infections caused by escherichia coli at the national

    African Journals Online (AJOL)


    pattern will guide paediatricians in choosing appropriate antibiotics for empirical treatment of neonatal infections. Methods: A retrospective ... resistant to commonly used antibiotics for treating neonatal infections but, susceptible to amikacin and imipenem. There is ... infections include neonatal sepsis, meningitis, pneumonia ...

  7. In Vitro Evaluation of Biofilm Dispersal as a Therapeutic Strategy To Restore Antimicrobial Efficacy

    DEFF Research Database (Denmark)

    Roizman, Dan; Vidaillac, Celine; Givskov, Michael


    engineered strain PAO1/pBAD-yhjH resulted in increased antimicrobial efficacy and synergy of the imipenem-tobramycin combination. These results support the use of biofilm dispersal to enhance antimicrobial efficacy in the treatment of biofilm-associated infections, representing a promising therapeutic...

  8. Is it safe to use carbapenems in patients with a history of allergy to penicillin? (United States)

    Sodhi, Manica; Axtell, Sandra S; Callahan, Joyce; Shekar, Raja


    The purpose of this retrospective study was to ascertain the clinical safety of administering carbapenems, namely imipenem/cilastatin and meropenem, in patients with a history of penicillin allergy compared with administering carbapenems in patients with no reported penicillin allergy. Carbapenems are similar in chemical structure to the penicillins and therefore are associated with a risk for allergic cross-hypersensitivity. Carbapenems are commonly avoided in patients with a reported penicillin allergy on the basis of a potential cross-hypersensitivity with penicillin, however, very few studies have been conducted describing the incidence of cross-hypersensitivity between penicillin and carbapenems. A retrospective review was conducted in a total of 266 patients who were administered either imipenem/cilastatin or meropenem. The patients were admitted to the Cleveland Clinic Health System--Eastern Region Hospitals during the years 2001 and 2002. Fifteen of the 163 patients (9.2%) with reported penicillin allergy developed a hypersensitivity reaction to meropenem or imipenem/cilastatin whereas 3.9% of the 103 patients without penicillin allergy developed a hypersensitivity reaction to meropenem or imipenem/cilastatin. These results are not statistically significant. Based on this study and other similar studies, the true incidence of cross-hypersensitivity reactions between penicillin and carbapenems may be lower than previously reported. Carbapenem use may be reasonable for penicillin allergic patients if caution is exercised.

  9. Antibiogram and plasmid profiling of carbapenemase and extended ...

    African Journals Online (AJOL)


    v13i4.33 ... implication of this on the community and National .... culture plate showing positive samples using the Modified Hodge test for Carbapenemase resistance testing on our our isolates (At the center is Imipenem antibiotic disk 10ìg). M. 2.

  10. Phenotypic and Genotypic Characterization of Pasteurella Multocida ...

    African Journals Online (AJOL)

    When the 6 isolates were tested for susceptibility to 15 antimicrobial agents by the standardized single disk method and minimal inhibitory concentrations, all isolates showed multi-drug resistance, but were all found to be susceptible to ciprofloxacin, levofloxacin, cefotaxime, ampicillin-clavulanic acid and imipenem.

  11. Antibiotic resistance properties of uropathogenic Escherichia coli ...

    African Journals Online (AJOL)

    Antibiotic resistance properties of uropathogenic Escherichia coli isolated from pregnant women with history of recurrent urinary tract infections. ... of infected pregnant women with imipenem, mezlocillin and nitrofurantoin would be effective for the prevention and management of vaginal infections in pregnant women.

  12. Prevalence, aetiology and antibiotic sensitivity profile of ...

    African Journals Online (AJOL)

    Escherichia coli were the common organism isolated at 38.8%. The majority of the organisms were sensitive to imipenem and gentamycin. Conclusion: There is a high prevalence of ASB among pregnant women included in the study from the Nairobi county clinics. Therefore, routine ASB screening of pregnant women is ...

  13. First case of Nocardia amamiensis pulmonary infection in Mexico

    Directory of Open Access Journals (Sweden)

    A. Martinez-Gamboa


    Full Text Available We report a case of Nocardia amamiensis pulmonary infection in a 43-year-old immunocompromised woman. The patient was treated with imipenem/cilastatin and trimethoprim/sulfamethoxazole and had a favourable outcome. It is important that laboratories perform species identification to understand the epidemiology and susceptibility patterns of the different Nocardia spp.

  14. The effect of mutations in the AmpC promoter region on β-lactam ...

    African Journals Online (AJOL)



    Aug 4, 2008 ... Martinez-Martinez L, Conejo MC, Pascual A, Hernandez-Alles S,. Ballesta S, Ramirez De Arellano-Ramos E, Benedi VJ, Perea EJ. (2000). Activities of imipenem and cephalosporins against clonally related strains of Escherichia coli hyper-producing chromosomal β- lactamase and showing altered porin ...

  15. Detection and Genetic Characterization of Metallo-β-Lactamase IMP-1 and VIM-2 in Pseudomonas aeruginosa Strains From Different Hospitals in Kermanshah, Iran. (United States)

    Abiri, Ramin; Mohammadi, Pantea; Shavani, Navid; Rezaei, Mansour


    Pseudomonas aeruginosais a frequent nosocomial pathogen that causes severe diseases in many settings. Carbapenems, including meropenem and imipenem, are effective antibiotics against this organism. However, the use of carbapenems has been hampered by the emergence of strains resistant to carbapenemsvia different mechanisms such as the production of metallo-β-lactamases (MBLs), which hydrolyze all carbapenems. Several kinds of MBLs have been reported, among them VIM and IMP types being the most clinically significant carbapenemases. We aimed to determine the distribution of bla VIM-2 and bla IMP-1 transferable genes encoding MBLs in P. aeruginosa isolated from three academic hospitals in Kermanshah. From 22nd June to 22nd September 2012, 225 isolates of P. aeruginosa were collected. These isolates were tested for antibiotic susceptibility with the Kirby-Bauer disk-diffusion method, and the MBLs were assessed using the imipenem-EDTA double-disk synergy test. The isolates were investigated for bla VIM - 2 and bla IMP-1 genes using polymerase chain reaction. Among the 225 isolates, 33.7% (76/225) and 18.1% (41/225) were resistant to imipenem and meropenem, respectively. Of the 76 imipenem-resistant P. aeruginosa strains, 45 (59.2%) were positive for MBLs, 34 (75%) strains carried the bla IMP-1 gene, and 1 (2.2%) strain carried the bla VIM - 2 gene. Our results showed that there was a high frequency of IMP-1 positive P. aeruginosa in the different wards of the hospitals.

  16. Evaluation of different methods for detection of metallo-beta-lactamases in Pseudomonas aeruginosa clinical isolates. (United States)

    Bogiel, Tomasz; Deptuła, Aleksander; Gospodarek, Eugenia


    Metallo-beta-lactamases (MBLs) produced by Pseudomnonas aeruginosa are a serious threat due to their ability to be transmitted between the same as well as different bacterial species. Different methods are applied in the clinical laboratory to detect MBLs. The aim of this study was to compare 4 phenotypic methods and a PCR assay for their ability to detect MBLs in clinical isolates of carbapenem-resistant P. aeruginosa strains. The study embraced a total of 70 carbapenem-resistant P. aeruginosa strains isolated in The Department of Microbiology of Dr. A. Jurasz University Hospital in Bydgoszcz. The highest percentage (42.9%) of the strains were isolated from Intensive Care Unit patients, mainly from urine samples (31.4%). Methods used in this study were: double-disc synergy tests in two combinations: using ceftazidime with 2-mercaptopropionic acid and imipenem with EDTA, differences in inhibition zone diameters between discs with imipenem/EDTA and imipenem, Etest MBL (AB Biodisk) and molecular amplification of bla(IMP) and bla(VIM) genes responsible for producing MBLs, using PCR assay. The lowest percentage (1.4%) of positive results in detection of MBLs was obtained using PCR assay, the highest (72.9%) by double-disc synergy tests with imipenem and EDTA, but the specificity of this method may be low.

  17. Usefulness of phenotypic and genotypic methods for metallo-beta-lactamases detection in carbapenem-resistant Acinetobacter baumannii strains. (United States)

    Szejbach, Aleksandra; Mikucka, Agnieszka; Bogiel, Tomasz; Gospodarek, Eugenia


    Acinetobacter baumannii is an opportunistic microorganism with an increasing role in nosocomial outbreaks. For the last 2 decades, a growing number of carbapenem-resistant A. baumannii strains have been identified, including the metallo-beta-lactamases (MBLs) producers. The study aimed to investigate the genetic relatedness of, and MBLs production among, a collection of A. baumannii isolates from Poland. This study involved 78 clinical isolates of carbapenem-resistant A. baumannii. Strain typing of the isolates was performed using PCR-RAPD. The presence of MBLs was phenotypically determined using different double disc synergy tests (DDST), the imipenem/EDTA combination disk test (CDT) and Etest MBL. blaIMP and blaVIM genes were detected using a duplex PCR assay. The isolates were divided into 18 PCR-RAPD patterns. Among 18 examined isolates, 94.4% were MBL-positive by the phenotypic method relying on comparing the bacteria growth inhibition zones diameters between imipenem/EDTA and imipenem discs, 88.9% using Etest MBL, 66.7% using the double disc synergy test with ceftazidime, imipenem, meropenem and EDTA, and 88.9% using a corresponding method with 2-MPA. The existence of blaIMP was identified in 8 (10.3%) strains. MBLs production was an important mechanism of carbapenem resistance among A. baumannii isolates in Poland. Laboratories should routinely screen for MBLs among A. baumannii isolates.

  18. Catheter-Associated Urinary Tract Infections (United States)

    ... FAQ CRE Definition Facilities/Settings State Health Departments Gram-negative Bacteria Hepatitis HIV Occupationally Acquired HIV/AIDS in ... ESBLs Detection of Imipenem or Meropenem-resistance in Gram-negative Organisms Detection of: Oxacillin/MRSA Detection of VISA/ ...

  19. Types of Healthcare-Associated Infections (United States)

    ... FAQ CRE Definition Facilities/Settings State Health Departments Gram-negative Bacteria Hepatitis HIV Occupationally Acquired HIV/AIDS in ... ESBLs Detection of Imipenem or Meropenem-resistance in Gram-negative Organisms Detection of: Oxacillin/MRSA Detection of VISA/ ...

  20. Frequently Asked Questions about Surgical Site Infections (United States)

    ... FAQ CRE Definition Facilities/Settings State Health Departments Gram-negative Bacteria Hepatitis HIV Occupationally Acquired HIV/AIDS in ... ESBLs Detection of Imipenem or Meropenem-resistance in Gram-negative Organisms Detection of: Oxacillin/MRSA Detection of VISA/ ...

  1. Emergence and clonal dissemination of carbapenem-hydrolysing OXA-58-producing Acinetobacter baumannii isolates in Bolivia. (United States)

    Sevillano, Elena; Fernández, Elena; Bustamante, Zulema; Zabalaga, Silvia; Rosales, Ikerne; Umaran, Adelaida; Gallego, Lucía


    Acinetobacter baumannii is an emerging multidrug-resistant pathogen and very little information is available regarding its imipenem resistance in Latin American countries such as Bolivia. This study investigated the antimicrobial resistance profile of 46 clinical strains from different hospitals in Cochabamba, Bolivia, from March 2008 to July 2009, and the presence of carbapenemases as a mechanism of resistance to imipenem. Isolates were obtained from 46 patients (one isolate per patient; 30 males,16 females) with an age range of 1 day to 84 years, and were collected from different sample types, the majority from respiratory tract infections (17) and wounds (13). Resistance to imipenem was detected in 15 isolates collected from different hospitals of the city. These isolates grouped into the same genotype, named A, and were resistant to all antibiotics tested including imipenem, with susceptibility only to colistin. Experiments to detect carbapenemases revealed the presence of the OXA-58 carbapenemase. Further analysis revealed the location of the bla(OXA-58) gene on a 40 kb plasmid. To our knowledge, this is the first report of carbapenem resistance in A. baumannii isolates from Bolivia that is conferred by the OXA-58 carbapenemase. The presence of this gene in a multidrug-resistant clone and its location within a plasmid is of great concern with regard to the spread of carbapenem-resistant A. baumannii in the hospital environment in Bolivia.

  2. Beta-lactamases of Kluyvera ascorbata, probable progenitors of some plasmid-encoded CTX-M types. (United States)

    Humeniuk, Christel; Arlet, Guillaume; Gautier, Valerie; Grimont, Patrick; Labia, Roger; Philippon, Alain


    Kluyvera ascorbata produces a beta-lactamase that results in an atypical susceptibility pattern, including low-level resistance to penicillins, cephalothin, and cefuroxime, but this resistance is reversed by clavulanate. Ten nucleotide sequences of the corresponding gene, bla(KLUA), were obtained and were found to have minor variations (96 to 100%). Otherwise, bla(KLUA) was found to be similar (95 to 100%) to some plasmid-encoded CTX-M-type beta-lactamases. Finally, mobilization of bla(KLUA) on a plasmid was found to be mediated probably by a genetic mobile element like ISEcp1.

  3. β-Lactamases of Kluyvera ascorbata, Probable Progenitors of Some Plasmid-Encoded CTX-M Types (United States)

    Humeniuk, Christel; Arlet, Guillaume; Gautier, Valerie; Grimont, Patrick; Labia, Roger; Philippon, Alain


    Kluyvera ascorbata produces a β-lactamase that results in an atypical susceptibility pattern, including low-level resistance to penicillins, cephalothin, and cefuroxime, but this resistance is reversed by clavulanate. Ten nucleotide sequences of the corresponding gene, blaKLUA, were obtained and were found to have minor variations (96 to 100%). Otherwise, blaKLUA was found to be similar (95 to 100%) to some plasmid-encoded CTX-M-type β-lactamases. Finally, mobilization of blaKLUA on a plasmid was found to be mediated probably by a genetic mobile element like ISEcp1. PMID:12183268

  4. Enterobacter Asburiae Pneumonia with Cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Seung Woo; Heo, Jeong Nam; Park, Choong Ki [Dept. of Radiology, Hanyang University College of Medicine, Guri Hospital, Guri (Korea, Republic of); Choi, Yo Won; Jeon, Seok Chol [Dept. of Radiology, Hanyang University College of Medicine, Seoul Hospital, Seoul (Korea, Republic of)


    Enterobacter species have increasingly been identified as pathogens over the past several decades. These bacterial species have become more important because most are resistant to cephalothin and cefoxitin, and can produce extended-spectrum {beta}-lactamase. Enterobacter asburiae (E. asburiae) is a gram-negative rod of the family Enterobacteriaceae, named in 1986. Since then, there has been only one clinical report of E. asburiae pneumonia. We report a case of E. asburiae pneumonia with cavitation and compare it with the previous case.

  5. A rare case of Shewanella putrefaciens bacteremia in a patient of road traffic accident

    Directory of Open Access Journals (Sweden)

    Ritesh Ranjan


    Full Text Available Shewanella putrefaciens rarely causes human infection. These are mostly found in environment and food stuffs. Shewanella are often found in mixed culture. It has been implicated in cellulitis, otitis media, and septicemia. It may be found in respiratory tract, urine, feces, and pleural fluid. There is no definite guideline for therapeutic option. In general, these are susceptible to various antimicrobial agents but are often resistant to penicillin and cephalothin. We report a rare case of bacteremia by S. putrefaciens in a patient of head injury with polytrauma after a road traffic accident.

  6. Antimicrobial activity of MDL 19,592: an oral cephalosporin. (United States)

    Jones, R N; Barry, A L


    MDL 19,592, a semisynthetic oral cephalosporin, has an antimicrobial spectrum principally directed against Gram-positive cocci (MIC50, 0.25-4 micrograms/ml), Branhamella catarrhalis (MIC50, 1-2 micrograms/ml), and pathogenic Neisseria spp. such as meningococci (MIC50, 4 micrograms/ml). Enterobacteriaceae, enterococci, Pseudomonas spp., Corynebacterium jeikeium, and Acinetobacter calcoaceticus strains had MDL 19,592 MIC50 of greater than or equal to 32 micrograms/ml. Although MDL 19,592 generally had a spectrum most similar to cefadroxil, it could not be represented by the cephalothin susceptibility test because of low predictive values and MIC correlations.

  7. Characteristics of an Aeromonas trota strain isolated from cerebrospinal fluid. (United States)

    Dallagassa, Cibelle B; Surek, Monica; Vizzotto, Bruno S; Prediger, Karoline C; Moriel, Bárbara; Wolf, Suélen; Weiss, Vinícius; Cruz, Leonardo M; Assis, Flávia E A; Paludo, Katia S; Rego, Fabiane G M; Farah, Sônia M S S; Picheth, Geraldo; Souza, Emanuel M; Pedrosa, Fábio O; Chubatsu, Leda S; Fadel-Picheth, Cyntia M T


    Aeromonas are ubiquitous in aquatic habitats. However some species can cause infections in humans, but rarely meningitis. Here we describe the isolation and characterization of an Aeromonas strain from cerebrospinal fluid of a meningitis patient. The isolate, identified as A. trota by biochemical and molecular methods, was susceptible to ampicillin but resistant to cephalothin and cefazolin. Genome sequencing revealed virulence factor genes such as type VI secretion system, aerolysin and lateral flagella. The isolate exhibited swarming motility, hemolytic activity and adhesion and cytotoxicity on HeLa cells. This is the first report of A. trota associated with meningitis and its virulence characteristics. Copyright © 2018. Published by Elsevier Ltd.

  8. Antimicrobial susceptibility of Prototheca zopfii isolated from bovine intramammary infections. (United States)

    McDonald, J S; Richard, J L; Anderson, A J


    In vitro antimicrobial susceptibility tests were carried out on 48 strains of Prototheca zopfii, an achlorophyllous algae causing refractory mastitis in dairy cows; 27 antimicrobials were evaluated. All strains were susceptible to both myxin and nystatin. In addition, 22 strains were susceptible to amphotericin B, 21 to polymyxin B, and 18 to gentamicin. Only 1 strain was susceptible to kanamycin. All strains were resistant to ampicillin, bacitracin, carbenicillin, cephalothin, chloramphenicol, clotrimazole, cloxacillin, erythromycin, flucytosine, ketoconazole, lincomycin, miconazole, neomycin, nitrofurazone, novobiocin, oleandomycin, penicillin, rifampin, streptomycin, tetracycline, and vancomycin.

  9. Selecting the best AOP for isoxazolyl penicillins degradation as a function of water characteristics: Effects of pH, chemical nature of additives and pollutant concentration. (United States)

    Villegas-Guzman, Paola; Silva-Agredo, Javier; Florez, Oscar; Giraldo-Aguirre, Ana L; Pulgarin, Cesar; Torres-Palma, Ricardo A


    To provide new insights toward the selection of the most suitable AOP for isoxazolyl penicillins elimination, the degradation of dicloxacillin, a isoxazolyl penicillin model, was studied using different advanced oxidation processes (AOPs): ultrasound (US), photo-Fenton (UV/H2O2/Fe2+) and TiO2 photocatalysis (UV/TiO2). Although all processes achieved total removal of the antibiotic and antimicrobial activity, and increased the biodegradability level of the solutions, significant differences concerning the mineralization extend, the pH of the solution, the pollutant concentration and the chemical nature of additives were found. UV/TiO2 reached almost complete mineralization; while ∼10% mineralization was obtained for UV/H2O2/Fe2+ and practically zero for US. Effect of initial pH, mineral natural water and the presence of organic (glucose, 2-propanol and oxalic acid) were then investigated. UV/H2O2/Fe2+ and US processes were improved in acidic media, while natural pH favored UV/TiO2 system. According to both the nature of the added organic compound and the process, inhibition, no effect or enhancement of the degradation rate was observed. The degradation in natural mineral water showed contrasting results according to the antibiotic concentration: US process was enhanced at low concentration of dicloxacillin followed by detrimental effects at high substrate concentrations. A contrary effect was observed during photo-Fenton, while UV/TiO2 was inhibited in all of cases. Finally, a schema illustrating the enhancement or inhibiting effects of water matrix is proposed as a tool for selecting the best process for isoxazolyl penicillins degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Hollow-Fiber Pharmacodynamic Studies and Mathematical Modeling To Predict the Efficacy of Amoxicillin for Anthrax Postexposure Prophylaxis in Pregnant Women and Children (United States)

    VanScoy, Brian; Liu, Weiguo; Kulawy, Robert; Drusano, G. L.


    Amoxicillin is considered an option for postexposure prophylaxis of Bacillus anthracis in pregnant and postpartum women who are breastfeeding and in children because of the potential toxicities of ciprofloxacin and doxycycline to the fetus and child. The amoxicillin regimen that effectively kills B. anthracis and prevents resistance is unknown. Fourteen-day dose range and dose fractionation studies were conducted in in vitro pharmacodynamic models to identify the exposure intensity and pharmacodynamic index of amoxicillin that are linked with optimized killing of B. anthracis and resistance prevention. Studies with dicloxacillin, a drug resistant to B. anthracis beta-lactamase, evaluated the role of beta-lactamase production in the pharmacodynamic indices for B. anthracis killing and resistance prevention. Dose fractionation studies showed that trough/MIC and not time above MIC was the index for amoxicillin that was linked to successful outcome through resistance prevention. Failure of amoxicillin regimens was due to inducible or stable high level expression of beta-lactamases. Studies with dicloxacillin demonstrated that a time above MIC of ≥94% was linked with treatment success when B. anthracis beta-lactamase activity was negated. Recursive partitioning analysis showed that amoxicillin regimens that produced peak concentrations of 1.75 μg/ml provided a 100% success rate. Other amoxicillin peak and trough values produced success rates of 28 to 67%. For postpartum and pregnant women and children, Monte Carlo simulations predicted success rates for amoxicillin at 1 g every 8 h (q8h) of 53, 33, and 44% (30 mg/kg q8h), respectively. We conclude that amoxicillin is suboptimal for postexposure prophylaxis of B. anthracis in pregnant and postpartum women and in children. PMID:24041894

  11. Molecular epidemiology of Acinetobacter baumannii and Acinetobacter nosocomialis in Germany over a 5-year period (2005-2009). (United States)

    Schleicher, X; Higgins, P G; Wisplinghoff, H; Körber-Irrgang, B; Kresken, M; Seifert, H


    To investigate the species distribution within the Acinetobacter calcoaceticus-Acinetobacter baumannii complex and the molecular epidemiology of A. baumannii and Acinetobacter nosocomialis, 376 Acinetobacter isolates were collected prospectively from hospitalized patients at 15 medical centres in Germany during three surveillance studies conducted over a 5-year period. Species identification was performed by molecular methods. Imipenem minimum inhibitory concentrations (MIC) were determined by broth microdilution. The prevalence of the most common carbapenemase-encoding genes was investigated by oxacillinase (OXA) -multiplex polymerase chain reaction (PCR). The molecular epidemiology was investigated by repetitive sequence-based PCR (rep-PCR; DiversiLab™). Acinetobacter pittii was the most prevalent Acinetobacter species (n = 193), followed by A. baumannii (n = 140), A. calcoaceticus (n = 10) and A. nosocomialis (n = 8). The majority of A. baumannii was represented by sporadic isolates (n = 70, 50%) that showed unique rep-PCR patterns, 25 isolates (18%) clustered with one or two other isolates, and only 45 isolates (32%) belonged to one of the previously described international clonal lineages. The most prevalent clonal lineage was international clone (IC) 2 (n = 34) and IC 1 (n = 6). According to CLSI, 25 A. baumannii isolates were non-susceptible to imipenem (MIC ≥ 8 mg/L), all of which produced an OXA-58-like or OXA-23-like carbapenemase. The rate of imipenem susceptibility among A. baumannii isolates decreased from 96% in 2005 to 76% in 2009. All other Acinetobacter isolates were susceptible to imipenem. The population structure of carbapenem-susceptible A. baumannii in Germany is highly diverse. Imipenem non-susceptibility was strongly associated with the clonal lineages IC 2 and IC 1. These data underscore the high clonality of carbapenem-resistant A. baumannii isolates. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of

  12. Antimicrobial resistance patterns among Gram-negative bacilli isolated from patients with nosocomial infections: Disk diffusion versus E-test

    Directory of Open Access Journals (Sweden)

    Hadadi A


    Full Text Available Background: The object of this study was to investigate the antimicrobial resistance pattern among common nosocomial Gram-negative bacilli isolated from patients with nosocomial infections. Methods: From June 2004 to December 2005, 380 isolates of common Gram-negative bacilli (Klebsiella, Pseudomonas, Acinetobacter and E. coli from 270 patients with nosocomial infections in Sina and Imam Hospitals, Tehran, Iran, were evaluated for susceptibility to Imipenem, Cefepime, Ciprofloxacine, Ceftriaxone and Ceftazidime by Disc diffusion and E-test methods. Results: The most frequent pathogens isolated were Klebsiella spp. (40%, followed by Pseudomonas (28%, Acinetobacter spp. (20% and E. coli (12%. The most active antibiotic was imipenem (84%. 26% of all isolates were sensitive to Cefepime, 26% to Ciprofloxacin, 20% to Ceftazidime and 10% to Ceftrixone. The susceptibility rates of Klebsiella to Imipenem, cefepime, ciprofloxacin, Ceftazidime and Ceftriaxone were 91, 25, 21, 13 and 7 percent, respectively and 91, 19, 17, 21 and 21 percent, respectively, for E. coli. Among Acineto- bacter spp., the susceptibility rate was 77% for Imipenem and 21% for Ciprofloxacin. Among Pseudomonas spp., 75% of isolates were susceptible to Imipenem and 39% to Ciprofloxacin. The comparison of the resistance status of microorganisms by both Disc diffusion and E-test methods showed a clinically noticeable agreement between these two tests. Conclusions: Since antibiotic resistance among Gram-negative bacilli has increased, enforcement of policy regarding proper antibiotic use is urgently needed in order to delay the development of resistance. Although it is widely accepted that E-test is more accurate in determining the resistance of microorganisms, our study showed that the Disc diffusion test will give the same results in most occasions and is therefore still considered useful in clinical practice.

  13. Comparative effects of carbapenems on bacterial load and host immune response in a Klebsiella pneumoniae murine pneumonia model. (United States)

    Hilliard, Jamese J; Melton, John L; Hall, LeRoy; Abbanat, Darren; Fernandez, Jeffrey; Ward, Christine K; Bunting, Rachel A; Barron, A; Lynch, A Simon; Flamm, Robert K


    Doripenem is a carbapenem with potent broad-spectrum activity against Gram-negative pathogens, including antibiotic-resistant Enterobacteriaceae. As the incidence of extended-spectrum β-lactamase (ESBL)-producing Gram-negative bacilli is increasing, it was of interest to examine the in vivo comparative efficacy of doripenem, imipenem, and meropenem against a Klebsiella pneumoniae isolate expressing the TEM-26 ESBL enzyme. In a murine lethal lower respiratory infection model, doripenem reduced the Klebsiella lung burden by 2 log(10) CFU/g lung tissue over the first 48 h of the infection. Treatment of mice with meropenem or imipenem yielded reductions of approximately 1.5 log(10) CFU/g during this time period. Seven days postinfection, Klebsiella titers in the lungs of treated mice decreased an additional 2 log(10) CFU/g relative to those in the lungs of untreated control animals. Lipopolysaccharide (LPS) endotoxin release assays indicated that 6 h postinfection, meropenem- and imipenem-treated animals had 10-fold more endotoxin in lung homogenates and sera than doripenem-treated mice. Following doripenem treatment, the maximum endotoxin release postinfection (6 h) was 53,000 endotoxin units (EU)/ml, which was 2.7- and 6-fold lower than imipenem or meropenem-treated animals, respectively. While the levels of several proinflammatory cytokines increased in both the lungs and sera following intranasal K. pneumoniae inoculation, doripenem treatment, but not meropenem or imipenem treatment, resulted in significantly increased interleukin 6 levels in lung homogenates relative to those in lung homogenates of untreated controls, which may contribute to enhanced neutrophil killing of bacteria in the lung. Histological examination of tissue sections indicated less overall inflammation and tissue damage in doripenem-treated mice, consistent with improved antibacterial efficacy, reduced LPS endotoxin release, and the observed cytokine induction profile.

  14. Efficient Detection of Carbapenemase Activity in Enterobacteriaceae by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry in Less Than 30 Minutes. (United States)

    Lasserre, Camille; De Saint Martin, Luc; Cuzon, Gaelle; Bogaerts, Pierre; Lamar, Estelle; Glupczynski, Youri; Naas, Thierry; Tandé, Didier


    The recognition of carbapenemase-producing Enterobacteriaceae (CPE) isolates is a major laboratory challenge, and their inappropriate or delayed detection may have negative impacts on patient management and on the implementation of infection control measures. We describe here a matrix-assisted laser desorption ionization-time of flight (MALDI-TOF)-based method to detect carbapenemase activity in Enterobacteriaceae. After a 20-min incubation of the isolate with 0.5 mg/ml imipenem at 37°C, supernatants were analyzed by MALDI-TOF in order to identify peaks corresponding to imipenem (300 Da) and an imipenem metabolite (254 Da). A total of 223 strains, 77 CPE (OXA-48 variants, KPC, NDM, VIM, IMI, IMP, and NMC-A) and 146 non-CPE (cephalosporinases, extended-spectrum β-lactamases [ESBLs], and porin defects), were tested and used to calculate a ratio of imipenem hydrolysis: mass spectrometry [MS] ratio = metabolite/(imipenem + metabolite). An MS ratio cutoff was statistically determined to classify strains as carbapenemase producers (MS ratio of ≥0.82). We validated this method first by testing 30 of our 223 isolates (15 CPE and 15 non-CPE) 10 times to calculate an intraclass correlation coefficient (ICC of 0.98), showing the excellent repeatability of the method. Second, 43 strains (25 CPE and 18 non-CPE) different from the 223 strains used to calculate the ratio cutoff were used as external controls and blind tested. They yielded sensitivity and specificity of 100%. The total cost per test is time-saving, cost-efficient, and highly reliable and might be used in any routine laboratory, given the availability of mass spectrometry, to detect CPE. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Atividade antimicrobiana in vitro da cefpiroma em comparação com outros beta-lactâmicos de amplo espectro contra 804 amostras clínicas de nove hospitais brasileiros Antimicrobial activity of Cefpirome compared to other broad-spectrum Beta-Lactam drugs against 804 clinical isolates from 9 Brazilian hospitals

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    H.S. Sader


    Full Text Available OBJETIVO: Avaliar a atividade in vitro da cefalosporina de quarta geração, cefpiroma em comparação com ceftazidima, ceftriaxona, cefotaxima e imipenem em um estudo multicêntrico envolvendo nove hospitais de seis cidades em quatro estados. MATERIAL E MÉTODOS: Foram estudadas 804 amostras clínicas isoladas em pacientes internados em unidades de terapia intensiva ou unidades de oncohematologia. As amostras foram coletadas no período de junho a novembro de 1995, isto é, antes da cefpiroma estar disponível comercialmente no Brasil, e testadas através do método de microdiluição em placas conforme descrito pelo National Committee for Clinical Laboratory Standards (NCCLS. Todas as amostras resistentes à cefpiroma foram retestadas utilizando-se o E-test. RESULTADOS: Contra as amostras de enterobactérias (n= 344, a cefpiroma apresentou atividade de 2 a 32 vezes superior àquela apresentada pelas cefalosporinas de terceira geração (CTGs e semelhante àquela apresentada pelo imipenem. As porcentagens de enterobactérias sensíveis foram: 88% para a cefpiroma, 69% para as CTGs e 96% para o imipenem. O espectro de ação da cefpiroma foi maior ou igual ao do imipenem contra as espécies Citrobacter freundii, E. aerogenes, Morganella morganii e Serratia marcescens. Contra Acinetobacter sp. (n=77, a cefpiroma foi ligeiramente mais ativa que a ceftazidima, porém as porcentagens de resistência foram muito altas para esses compostos (84% e 88% respectivamente. As atividades da cefpiroma, ceftazidima e imipenem foram semelhantes contra Pseudomonas aeruginosa (n=128, com MIC50/porcentagem de sensibilidade de 8/59%, 8/62% e 4/62% respectivamente. Contra bactérias aeróbias gram-positivas, a cefpiroma foi de 4 a 16 vezes mais ativa que as CTGs. Contra S. epidermidis e outras espécies de estafilococos coagulase-negativos a cefpiroma foi ligeiramente superior ao imipenem, porém, contra as outras espécies de bactérias gram-positivas avaliadas, o

  16. Identification of Antibiotics used in Clinical Surgery and Orthopedic Unit from Midsized Hospital in Mato Grosso

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    K. G. Lima


    Full Text Available Abstract: This study aimed to identify the pattern of antimicrobial use in a unit and orthopedic surgical clinic of a medium-sized hospital in Mato Grosso. The study based in analysis of 500 medical charts and filling out forms previously prepared from Regional Hospital of Sorriso, between March and April 2012, after approval of the project by CEP Julio Muller University Hospital (Protocol No. 219/2011. It was observed that 69% (345 of the sample were male, with ages ranging between 18 and 112 years. In all the charts can observe the prescription of antibiotics, the most prescribed the cephalothin 49.2% (297, Amikacin 12.27% (74 5.3% Gentamicin (32, Ciprofloxacin 4.31 % (26 and Clindamycin 3.31% (20. Among the 500 records analyzed only 9 (1.8% underwent antimicrobial prophylaxis and 491 (98.2 did not receive prophylaxis. Among the antimicrobials used in surgical prophylaxis met the cephalothin, used in 77.8% of cases and Clindamycin in 22.2% of cases, these drugs of second choice within the parameters of the National Health Surveillance Agency (ANVISA. The rational use of antibiotics reduce any risk of emergence of resistant microbial strains and still be profitable in terms pharmacoeconomicsKeywords: Antimicrobial; Surgical Clinic, Nursing; Antibiotic.

  17. Novel Quorum-Quenching Agents Promote Methicillin-Resistant Staphylococcus aureus (MRSA) Wound Healing and Sensitize MRSA to β-Lactam Antibiotics (United States)

    Kuo, David; Yu, Guanping; Hoch, Wyatt; Gabay, Dean; Long, Lisa; Ghannoum, Mahmoud; Nagy, Nancy; Harding, Clifford V.; Viswanathan, Rajesh


    The dwindling repertoire of antibiotics to treat methicillin-resistant Staphylococcus aureus (MRSA) calls for novel treatment options. Quorum-quenching agents offer an alternative or an adjuvant to antibiotic therapy. Three biaryl hydroxyketone compounds discovered previously (F1, F12, and F19; G. Yu, D. Kuo, M. Shoham, and R. Viswanathan, ACS Comb Sci 16:85–91, 2014) were tested for efficacy in MRSA-infected animal models. Topical therapy of compounds F1 and F12 in a MRSA murine wound infection model promotes wound healing compared to the untreated control. Compounds F1, F12, and F19 afford significant survival benefits in a MRSA insect larva model. Combination therapy of these quorum-quenching agents with cephalothin or nafcillin, antibiotics to which MRSA is resistant in monotherapy, revealed additional survival benefits. The quorum-quenching agents sensitize MRSA to the antibiotic by a synergistic mode of action that also is observed in vitro. An adjuvant of 1 μg/ml F1, F12, or F19 reduces the MIC of nafcillin and cephalothin about 50-fold to values comparable to those for vancomycin, the antibiotic often prescribed for MRSA infections. These findings suggest that it is possible to resurrect obsolete antibiotic therapies in combination with these novel quorum-quenching agents. PMID:25534736

  18. Synergistic Antibacterial Activity of Ampicillin-Cloxacillin Mixtures Against Proteus morganii (United States)

    Bornside, George H.


    Synergistic antibacterial effects of mixtures of ampicillin and cloxacillin and induced penicillinases were investigated in 48 strains of Proteus. The serial tube dilution method was used to determine the minimal inhibitory concentration of ampicillin, cloxacillin, and 2:1 and 1:1 mixtures of ampicillin and cloxacillin. Production of penicillinases was determined by the cellulose acetate membrane method, with ampicillin, cloxacillin, mixtures of ampicillin and cloxacillin, penicillin G, and cephalothin as inducing agents and as substrates for penicillinase. Synergism occurred against P. morganii, but against no other species. The 1:1 ampicillin-cloxacillin combination was synergistic against 13 of 17 P. morganii strains; the 2:1 combination was synergistic against only 9 strains. Penicillinases, demonstrated in all species except P. mirabilis, hydrolyzed penicillin G and cephalothin. Although only P. vulgaris hydrolyzed ampicillin, no species of Proteus hydrolyzed cloxacillin or the ampicillin-cloxacillin mixtures. Penicillinases were, however, induced by ampicillin, cloxacillin, and the mixtures. There was no relationship between production of penicillinase and synergism with mixtures of ampicillin and cloxacillin. PMID:5188339

  19. Actividad “in vitro” de 10 antimicrobianos frente a bacterias anaerobias: Estudio multicéntrico, 1999-2002 “In vitro” activity of ten antimicrobial agents against anaerobic bacteria. A collaborative study, 1999-2002

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    M. Litterio


    Full Text Available Se evaluó la actividad de ampicilina, ampicilina-sulbactama, cefoxitina, ceftriaxona, imipenem, piperacilina, piperacilina-tazobactama, clindamicina, metronidazol y azitromicina frente a 166 cepas de bacterias anaerobias aisladas en 8 hospitales de Buenos Aires. Se estudiaron: Bacteroides grupo fragilis (65, Fusobacterium spp. (26, Prevotella spp. (21, Porphyromonas spp. (10, Clostridium difficile (10, otros clostridios (12 y cocos gram-positivos (22. Las CIMs se determinaron usando el método patrón de dilución en agar recomendado por el NCCLS, documento M11-A5. Los antibióticos más activos fueron metronidazol y piperacilina-tazobactama que exhibieron valores de CIM90£ 2 µg/ml y £ 4 µg/ml frente a los microorganismos gram-negativos y £ 2 µg/ml y £ 8 µg/ml frente a los microorganismos gram-positivos, respectivamente. Entre los b-lactámicos el orden de actividad frente a bacilos gram-negativos fue: imipenem > piperacilina > cefoxitina > ceftriaxona > ampicilina. En gram-positivos la actividad decreciente fue: piperacilina> imipenem > cefoxitina > ceftriaxona > ampicilina. La mayoría de las especies estudiadas mostraron distintos niveles de resistencia con clindamicina y azitromicina. Sin embargo, el 90% de las cepas de Fusobacterium nucleatum y Por-phyromonas spp. fue inhibido por una concentración de 0,125 µg/ml de clindamicina y azitromicina, respectivamente.The antimicrobial activity of ampicillin, ampicillin-sulbactam, cefoxitin, ceftriaxone, imipenem, piperacillin, piperacillin-tazobactam, clindamycin, metronidazole, and azitromycin was assesed against 166 strains of anaerobic bacteria recovered from eight hospitals in Buenos Aires. The strains studied were Bacteroidesfragilis group (65, Fusobacterium spp. (26, Prevotella spp. (21, Porphyromonas spp. (10, Clostridium difficile (10, other clostridia (12, and gram-positive cocci (22. The MICs were determined by the agar dilution method according to NCCLS document M11-A5

  20. Detection of SPM and IMP metallo-β-lactamases in clinical specimens of Pseudomonas aeruginosa from a Brazilian public tertiary hospital

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    Carlos Henrique Camargo

    Full Text Available Phenotypic and genotypic SPM and IMP metallo-β-lactamases (MBL detection and also the determination of minimal inhibitory concentrations (MIC to imipenem, meropenem and ceftazidime were evaluated in 47 multidrug-resistant Pseudomonas aeruginosa isolates from clinical specimens. Polymerase chain reaction detected 14 positive samples to either blaSPM or blaIMP genes, while the best phenotypic assay (ceftazidime substrate and mercaptopropionic acid inhibitor detected 13 of these samples. Imipenem, meropenem and ceftazidime MICs were higher for MBL positive compared to MBL negative isolates. We describe here the SPM and IMP MBL findings in clinical specimens of P. aeruginosa from the University Hospital of Botucatu Medical School, São Paulo, Brazil, that reinforce local studies showing the high spreading of blaSPM and blaIMP genes among brazilian clinical isolates.

  1. The Survey for AmpC beta-lactamase Production and Characterization of Antibiotic Resistance Profile in Clinical Isolates of Klebsiella oxytoca

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    Mahbobeh Nassari


    beta-lactamase producing. Among examined antimicrobials, imipenem (100% and colistin (100% were most effective drugs against isolates. Respectively, 88.6%, 88.6%, 85.7% and 85.7% isolates were resistant to amikacin, cefoxitin, ciprofloxacin and cefepime. Strains showed the most frequent resistance to ceftazidime (20%. All AmpC beta-lactamase positive isolates were sensitive to amikacin, imipenem and colistin. Conclusion: Results of current study showed third-gerneration cephalosprins are not effective against 20% of infections caused by Klebsiella oxytoca. Resistance to two major classes of antibiotics (aminoglycosides and beta-lactams was seen among studied strains and treatment of infections causing by this isolates are major problem in future.

  2. Dynamics and spatial distribution of beta-lactamase expression in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Bagge, N.; Hentzer, Morten; Andersen, Jens Bo


    The development of resistance to beta-lactam antibiotics is a problem in the treatment of chronic Pseudomonas aeruginosa infection in the lungs of patients with cystic fibrosis. The main resistance mechanism is high-level expression of the chromosomally encoded AmpC beta-lactamase of P. aeruginosa...... of the ampC promoter to gfp(ASV) encoding an unstable version of the green fluorescent protein. In vitro biofilms of P. aeruginosa were exposed to the beta-lactam antibiotics imipenem and ceftazidime. Sub-MICs of imipenem significantly induced the monitor system of the biofilm bacteria in the peripheries...... distributions of beta-lactamase induction in P. aeruginosa cells growing in biofilms. Thus, our experiments show that P. aeruginosa cells growing in biofilms constitute a heterogeneous population unit which may create different antibiotic-selective environments for the bacteria in the biofilm....

  3. Klebsiella pneumoniae: resistance to carbapenems carbapenemase-mediated in the area of Piacenza

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    Massimo Confalonieri


    Full Text Available The detection of Klebsiella pneumoniae isolates showing a reduced susceptibility or resistance to carbapenems represents an increasing problem. The aim of this study is to survey the presence of carbapenemases producing strains in our country. 22 isolates of K. pneumoniae isolates showing carbapenems MIC => 2 by Vitek 2 System, were collected in the period May-August 2010 and studied for carbapenemases production using phenotypic confirmatory tests. The modified Hodge test and the DD-sinergy test with boronic acid yelded positive results for 17/22 strains; all the isolates resulted negative to the E-test MBL (imipenem and imipenem/EDTA. The results of this study confirm the recent emergence of KPC-producing K. pneumoniae strains in the area of Piacenza.The phenotypic tests employed appear reliable and simple for the confirmation of carbapenemases-production in K. pneumonie.

  4. Incidence of carbapenem-associated allergic-type reactions among patients with versus patients without a reported penicillin allergy. (United States)

    Prescott, William A; DePestel, Daryl D; Ellis, Jeffrey J; Regal, Randolph E


    This retrospective analysis sought to determine the comparative incidence of cross-reactivity associated with carbapenem antibiotic treatment among patients with versus those without penicillin allergy. We sought to determine whether the incidence of cross-reactivity is different between imipenem-cilastatin and meropenem. A total of 211 patients were treated with a carbapenem antibiotic. Included were 100 patients with and 111 patients without a documented or reported penicillin allergy. Within each group, subgroups of penicillin-allergic and penicillin-nonallergic patients were balanced equally between imipenem-cilastatin and meropenem. The incidence of patients with a reported or documented penicillin allergy experiencing an allergic-type reaction to a carbapenem was 11%, which is 5.2 times greater than the risk in patients who were reportedly not allergic to penicillin (P=.024). No difference in the occurrence of allergic-type reactions was observed between the 2 carbapenems.

  5. DNA fingerprinting and antimicrobial susceptibility pattern of clinical and environmental Acinetobacter baumannii isolates: a multicentre study. (United States)

    Salimizand, Himen; Menbari, Shaho; Ramazanzadeh, Rashid; Khonsha, Masomeh; Saleh Vahedi, Mohammad


    The aims of this study were to establish antibiotic profile and the molecular epidemiology of Acinetobacter baumannii isolates, with considering the effectiveness of control infection measures across three hospitals in the Kurdistan, west part of Iran. Fifty-four A. baumannii isolates were collected from patients and environmental specimens. Antibiotic susceptibility patterns (Antibio-type) were evaluated for 17 different antibiotics and MIC for imipenem was done. Isolates were assessed for the presence of metallo-beta-lactamases (MBLs), class 1 and 2 integrons, and integrated gene cassettes and blaOXA-likefamilies genes. Repetitive-sequence-based PCR (REP-PCR) was done for analysing clonality and relativeness of isolates (REP-type). Antibiotic susceptibility patterns distinguished 11 distinct Antibio-types and REP-PCR showed three clusters with 20 subclusters, mostly belonged to two clonal subgroups, A1 and B1. blaOXA-51 and blaOXA-23 were detected in 100% (54/54) and 52% (28/54), respectively, while blaOXA-24-like and blaOXA-58 were not present in isolates. MBLs were not detected, but, however, high rate of imipenem resistance was observed (52%). MIC90 of imipenem was 16 mg/ml. Class 1 integrons were detected in 11% (6/54) of isolates followed by 24% (13/54) of class 2. Both classes of integron genes were detected in 15% (8/54) of isolates. Integrated gene cassettes were in low level (11% of class 1 harboring isolates). Two arrays of gene cassettes were revealed, dfrA5-like and dfrA17-aadA5. Infection control surveillance should be considered as a serious manner, even the superficial eradication of hospital acquired pathogens. MBL genes were not induced carbapenem resistance in studied hospital settings, but blaOXA-51 & 23 contributed in imipenem resistant. Integrons had a little share in resistance of A. baumannii isolates.

  6. In vitro activity of SecA inhibitors in combination with carbapenems against carbapenem-hydrolysing class D β-lactamase-producing Acinetobacter baumannii. (United States)

    Chiu, Chun-Hsiang; Liu, Yu-Han; Wang, Yung-Chih; Lee, Yi-Tzu; Kuo, Shu-Chen; Chen, Te-Li; Lin, Jung-Chung; Wang, Fu-Der


    According to our previous study, OXA-58 translocates to the periplasm via the Sec pathway in carbapenem-resistant Acinetobacter baumannii (CRAb). In the present study, carbapenem-hydrolysing class D β-lactamases (CHDLs) belonging to the OXA-23, OXA-40 and OXA-51 families were examined to determine whether they are also Sec-dependent. Additionally, the effects of SecA inhibitors combined with carbapenems against CHDL-producing CRAb were examined. Cell fractionation and western blot analyses were performed to detect periplasmic His-tagged CHDLs. A chequerboard analysis with pairwise combinations of carbapenems (imipenem or meropenem) and SecA inhibitors (rose bengal, sodium azide or erythrosin B) was performed using six clinical CRAb isolates harbouring different CHDL genes. The fractional inhibitory concentration (FIC) index was determined. The combination with the lowest FIC index was subjected to a time-kill analysis to examine synergistic effects. In an in silico analysis, the CHDLs OXA-23, OXA-40 and OXA-51 were preferentially translocated via the Sec system. The SecA inhibitor rose bengal decreased periplasmic translocation of His-tagged OXA-23 and OXA-83 (belonging to the OXA-51 family), but not OXA-72 (belonging to the OXA-40 family) from ATCC 15151 transformants. Imipenem or meropenem with rose bengal showed synergistic effects (FIC index, ≤0.5) for six and four clinical isolates, respectively. Imipenem or meropenem with sodium azide showed no interactions (FIC index, 0.5-4) against all clinical isolates. Imipenem and rose bengal had the lowest FIC index and showed synergy at 24 h in the time-kill assay. Combinations of SecA inhibitors and carbapenems have synergistic effects against CHDL-producing CRAb. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail:

  7. Systemic Infection of an Immunocompromised Patient with Methylobacterium zatmanii


    Hornei, B.; Lüneberg, E; Schmidt-Rotte, H.; Maaß, M; Weber, K.; Heits, F.; Frosch, M.; Solbach, W


    We describe the identification of Methylobacterium zatmanii as the causative agent of bacteremia and fever in an immunocompromised patient. The patient, a 60-year-old man, had a 5-month history of acute myeloid leukemia and had been on chemotherapy throughout this period. Seven days after the onset of neutropenia, the patient developed fever. The combination of ciprofloxacin, co-trimoxazole, imipenem, amikacin, and vancomycin led to a complete defervescence. On subculture from six positive bl...

  8. Ocimum basilicum: Antibacterial activity and association study with antibiotics against bacteria of clinical importance. (United States)

    Araújo Silva, Viviane; Pereira da Sousa, Janiere; de Luna Freire Pessôa, Hilzeth; Fernanda Ramos de Freitas, Andrea; Douglas Melo Coutinho, Henrique; Beuttenmuller Nogueira Alves, Larissa; Oliveira Lima, Edeltrudes


    Ocimum basilicum L. (Lamiaceae), popularly known as basil, is part of a group of medicinal plants widely used in cooking and known for its beneficial health properties, possessing significant antioxidant effects, antinociceptive, and others. The objective of this study is to determine the pharmacological effects produced on the bacterial strains Staphylococcus aureus and Pseudomonas aeruginosa when standard antibiotics and O. basilicum essential oil are combined. The extraction of O. basilicum (leaves) components was done by steam distillation. The Minimum inhibitory concentration (MIC) was calculated using microdilution technique, where the oil concentrations varied from 2 to 1024 μg/mL. The combinations of O. basilicum oil with ciprofloxacin or imipenem were analyzed by the checkerboard method where fractional inhibitory concentration (FIC) indices were calculated. Ocimum basilicum essential oil, imipenem, and ciprofloxacin showed respective MIC antibacterial activities of 1024, 4, and 2 μg/mL, against S. aureus. In S. aureus, the oil with imipenem association showed synergistic effect (FIC = 0.0625), while the oil with ciprofloxacin showed antagonism (FIC value = 4.25). In P. aeruginosa, the imipenem/oil association showed additive effect for ATCC strains, and synergism for the clinical strain (FIC values = 0.75 and 0.0625). The association of O. basilicum essential oil with ciprofloxacin showed synergism for clinical strains (FIC value = 0.09). Ocimum basilicum essential oil associated with existing standard antibiotics may increase their antibacterial activity, resulting in a synergistic activity against bacterial strains of clinical importance. The antibacterial activity of O. basilicum essential oil may be associated with linalool.

  9. Klebsiella pneumoniaeoxa-48 kod urološkog bolesnika: prikaz slučaja


    JAJIĆ, Ines; Benčić, Ana; Siroglavić, Marko; Zarfel, Gernot; Ružić, Boris; Pezelj, Ivan; Bedenić, Branka


    Prikazan je izolat Klebsiella pneumoniae OXA-48 izoliran iz mokraće 68-godišnjeg muškaraca kojemu je napravljena radikalna prostatektomija zbog raka prostate. Testiranje osjetljivosti izolata na velik broj antibiotika provedeno je metodom disk difuzije kao i metodom određivanja minimalnih inhibitornih koncentracija. Izolat je klasificiran kao višestruko rezistentan. Smanjeno je osjetljiv na imipenem i meropenem, rezistentan na ertapenem, a osjetljiv samo na kolistin, amikacin i trimetoprim+su...

  10. Spectrophotometry-based detection of carbapenemase producers among Enterobacteriaceae. (United States)

    Bernabeu, Sandrine; Poirel, Laurent; Nordmann, Patrice


    Carbapenem-hydrolyzing ß-lactamases are the most powerful ß-lactamases being able to hydrolyse almost all ß-lactams. They are mostly of the KPC, VIM, IMP, NDM, and OXA-48 type. A spectrophotometry technique based on analysis of the imipenem hydrolysis has been developed that differentiated carbapenemase- from noncarbapenemase producers. This inexpensive technique adapted to screening of carbapenemase producers may be implemented in any reference laboratory worldwide. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. [Strains of Klebsiella isolated from patients Łódź hospitals in 2006 year]. (United States)

    Szczerba, Izabela; Gortat, Katarzyna; Majewski, Karol


    The aim of this study was to determine a susceptibility of 223 clinical strains Klebsiella to 11 antimicrobial agents and occurrence ESBL-positive strains. These strains were isolated from clinical specimens during 2006 year. Susceptibility of these strains against antimicrobial agents was determined with disc diffusion method according to CLSI recommendation. None of the analysed strains was resistant to imipenem. The Klebsiella pneumonie strains were most frequently isolated from respiratory tract.

  12. Increasing prevalence of extended-spectrum-betalactamase among Gram-negative bacilli in Latin America: 2008 update from the Study for Monitoring Antimicrobial Resistance Trends (SMART

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    Maria Virginia Villegas

    Full Text Available OBJECTIVES: This analysis of the Study for Monitoring Antimicrobial Resistance Trends (SMART evaluated the susceptibility patterns of Enterobacteriaceae in Latin America in 2008, with emphasis on susceptibility trends of E. coli and K. pneumoniae. METHODS: Clinical isolates were recovered from intra-abdominal infections (IAI from 23 centers in 10 Latin American countries. Isolates were sent to a central laboratory for confirmation of identification, antimicrobial susceptibility and ESBL testing, following the Clinical Laboratory Standards Institute (CLSI guidelines. RESULTS: Of 1,003 Gram-negative bacilli collected from intra-abdominal infections, E. coli and K. pneumoniae were the most commonly isolated organisms, and 26.8% of E. coli and 37.7% of K. pneumoniae were ESBL positive. Ertapenem and imipenem were the most consistently active agents tested; 99% of ESBLpositive E. coli isolates were susceptible to ertapenem and 100% to imipenem as well, and 91% of ESBL-positive K. pneumoniae were susceptible to ertapenem and 98% to imipenem. Quinolones and cephalosporins were less active, achieving 1.5% to 76% inhibition against ESBL-producing E. coli and 3.5% to 61% inhibition against K. pneumoniae. CONCLUSIONS: Local and unit-specific surveillance data is particularly important for selection of empiric therapy and in community-acquired infections as they can help the clinician with antibiotic selection by providing guidance regarding the likely pathogens and their resistance profiles. Our data also confirm the increasing frequency with which ESBL-producing organisms are found in the community setting, with 31.4% of communityacquired and 24.9% of hospital-acquired infections found to produce ESBLs. Imipenem and ertapenem are the most active agents tested for ESBL-positive E. coli and K. pneumoniae.

  13. In Vitro Susceptibilities of Burkholderia mallei in Comparison to Those of Other Pathogenic Burkholderia spp.


    Kenny, D. J.; Russell, P.; Rogers, D.; Eley, S M; Titball, R W


    The in vitro antimicrobial susceptibilities of isolates of Burkholderia mallei to 16 antibiotics were assessed and compared with the susceptibilities of Burkholderia pseudomallei and Burkholderia cepacia. The antibiotic susceptibility profile of B. mallei resembled that of B. pseudomallei more closely than that of B. cepacia, which corresponds to their similarities in terms of biochemistry, antigenicity, and pathogenicity. Ceftazidime, imipenem, doxycycline, and ciprofloxacin were active agai...

  14. Severe pneumonia due to Nocardia otitidiscaviarum identified by mass spectroscopy in a cotton farmer: A case report and literature review. (United States)

    Liu, Chen; Feng, Mei; Zhu, Jing; Tao, Ye; Kang, Mei; Chen, Lei


    Nocardia species are aerobic saprophytic bacilli. Among Nocardia species, Nocardia otitidiscaviarum (N otitidiscaviarum) is rarely reported in pulmonary infection. We reported a case of N otitidiscaviarum pneumonia in a cotton farmer. N otitidiscaviarum pneumonia was identified by mass spectroscopy. Combined treatments (amikacin, imipenem and trimethoprim-sulfamethoxazole) were administered after identification of N otitidiscaviarum. The patient eventually died from severe respiratory insufficiency in the hospital. Early precise diagnosis and prompt combined therapy are of vital importance in severe Nocardia pulmonary infection.

  15. Necrotizing gastritis due to Bacillus cereus in an immunocompromised patient. (United States)

    Le Scanff, J; Mohammedi, I; Thiebaut, A; Martin, O; Argaud, L; Robert, D


    Bacillus cereus is increasingly being acknowledged as a serious bacterial pathogen in immunocompromised patients. We present a case of acute necrotizing gastritis caused by B. cereus in a 37-year-old woman with acute myeloblastic leukemia, who recovered following total parenteral nutrition and treatment with imipenem and vancomycin. B. cereus was isolated from gastric mucosa and blood cultures. Up to now, no case of acute necrotizing gastritis due to this organism has been reported.

  16. Antimicrobial activity of beta-lactams against multiresistant micro-organisms from the family Enterobacteriaceae, and genus Pseudomonas. (United States)

    Niebla, A; González, I; Vallín, C


    The antimicrobial activity of twenty beta-lactams was determined against multiresistant micro-organisms from the Enterobacteriaceae family (450) and the genus Pseudomonas (90). The antimicrobial susceptibility was assessed by the disk diffusion method. The most effective antibiotics were cephalosporins of the second and third generation, and non-classical beta-lactams (imipenem and moxalactam). A pronounced resistance was found to carbenicillin, ampicillin, cephalotin and cefazolin. These resistance patterns corresponded to a high consumption of these antibiotics.

  17. Phenotypic and Biochemical Comparison of the Carbapenem-Hydrolyzing Activities of Five Plasmid-Borne AmpC β-Lactamases ▿ (United States)

    Mammeri, Hedi; Guillon, Hélène; Eb, François; Nordmann, Patrice


    The CMY-2, ACT-1, DHA-1, ACC-1, and FOX-1 enzymes are representative of five plasmid-mediated AmpC (pAmpC) β-lactamase clusters. Resistance to imipenem has been reported in Enterobacteriaceae as a result of pAmpC expression combined with decreased outer membrane permeability. The aim of this study was to determine the role of different pAmpCs in carbapenem resistance and to define the structure/activity relationship supporting carbapenemase activity. The ampC genes encoding the five pAmpCs and the chromosomal AmpC of Escherichia coli EC6, which was used as a reference cephalosporinase, were cloned and introduced into wild-type E. coli TOP10 and OmpC/OmpF porin-deficient E. coli HB4 strains. The MICs of β-lactams for the recombinant strains revealed that CMY-2, ACT-1, and DHA-1 β-lactamases conferred a high level of resistance to ceftazidime and cefotaxime once expressed in E. coli TOP10 and reduced significantly the susceptibility to imipenem once expressed in E. coli HB4. In contrast, FOX-1 and ACC-1 enzymes did not confer resistance to imipenem. Biochemical analysis showed that CMY-2 β-lactamase and, to a lesser extent, ACT-1 exhibited the highest catalytic efficiency toward imipenem and showed low Km values. A modeling study revealed that the large R2 binding site of these two enzymes may support the carbapenemase activity. Therefore, CMY-2-type, ACT-1-type, and DHA-1-type β-lactamases may promote the emergence of carbapenem resistance in porin-deficient clinical isolates. PMID:20733047

  18. Phenotypic and biochemical comparison of the carbapenem-hydrolyzing activities of five plasmid-borne AmpC β-lactamases. (United States)

    Mammeri, Hedi; Guillon, Hélène; Eb, François; Nordmann, Patrice


    The CMY-2, ACT-1, DHA-1, ACC-1, and FOX-1 enzymes are representative of five plasmid-mediated AmpC (pAmpC) β-lactamase clusters. Resistance to imipenem has been reported in Enterobacteriaceae as a result of pAmpC expression combined with decreased outer membrane permeability. The aim of this study was to determine the role of different pAmpCs in carbapenem resistance and to define the structure/activity relationship supporting carbapenemase activity. The ampC genes encoding the five pAmpCs and the chromosomal AmpC of Escherichia coli EC6, which was used as a reference cephalosporinase, were cloned and introduced into wild-type E. coli TOP10 and OmpC/OmpF porin-deficient E. coli HB4 strains. The MICs of β-lactams for the recombinant strains revealed that CMY-2, ACT-1, and DHA-1 β-lactamases conferred a high level of resistance to ceftazidime and cefotaxime once expressed in E. coli TOP10 and reduced significantly the susceptibility to imipenem once expressed in E. coli HB4. In contrast, FOX-1 and ACC-1 enzymes did not confer resistance to imipenem. Biochemical analysis showed that CMY-2 β-lactamase and, to a lesser extent, ACT-1 exhibited the highest catalytic efficiency toward imipenem and showed low K(m) values. A modeling study revealed that the large R2 binding site of these two enzymes may support the carbapenemase activity. Therefore, CMY-2-type, ACT-1-type, and DHA-1-type β-lactamases may promote the emergence of carbapenem resistance in porin-deficient clinical isolates.

  19. In vitro evaluation of broad-spectrum beta-lactams tested in medical centers in Korea: role of fourth-generation cephalosporins. The Korean Antimicrobial Resistance Study Group. (United States)

    Lewis, M T; Biedenbach, D J; Jones, R N


    Levels of resistance to the "third-generation" cephalosporins among isolates of clinical bacteria in Korea have been increasing at a rapid rate. This study evaluated the activity of cefepime, a "fourth-generation" cephalosporin, and six other broad-spectrum beta-lactam antimicrobials (cefpirome, ceftazidime, ceftriaxone, imipenem, piperacillin/tazobactam 4 micrograms/mL fixed concentration[, oxacillin) against 404 isolates of clinical bacteria from Korea. Susceptibility profiles of each isolate were established using the Etest (AB BIODISK, Solna, Sweden) method of susceptibility testing. Only the carbapenem imipenem was > 90% effective in inhibiting each of the species tested (Escherichia coli, Klebsiella, spp., Citrobacter spp., Enterobacter spp., indole-positive Proteae, Serratia spp., Acinetobacter spp., Pseudomonas aeruginosa, and oxacillin-susceptible staphylococci). Imipenem was followed by cefepime > cefpirome > piperacillin/tazobactam > ceftazidime > ceftriaxone in overall rank order of usable spectrum against the isolates tested. Extended spectrum beta-lactamase producing phenotypes were much more prevalent among the Klebsiella spp. (48.8%) than the E. coli (5.0%) isolates. Cefepime was much more active than cefpirome, 95.1% susceptible as compared with 70.7% susceptible, against the 41 isolates of Klebsiella spp. The results of this study corroborates findings from earlier studies with levels of resistance to the broad-spectrum beta-lactams in Korea continuing to rise indicating the need for intervention strategies.

  20. Different Subsets of Enteric Bacteria Induce and Perpetuate Experimental Colitis in Rats and Mice (United States)

    Rath, Heiko C.; Schultz, Michael; Freitag, René; Dieleman, Levinus A.; Li, Fengling; Linde, Hans-Jörg; Schölmerich, Jürgen; Sartor, R. Balfour


    Resident bacteria are incriminated in the pathogenesis of experimental colitis and inflammatory bowel diseases. We investigated the relative roles of various enteric bacteria populations in the induction and perpetuation of experimental colitis. HLA-B27 transgenic rats received antibiotics (ciprofloxacin, metronidazole, or vancomycin-imipenem) in drinking water or water alone in either prevention or treatment protocols. Mice were treated similarly with metronidazole or vancomycin-imipenem before or after receiving 5% dextran sodium sulfate (DSS). Germfree transgenic rats were colonized with specific-pathogen-free enteric bacteria grown overnight either in anaerobic or aerobic atmospheres. Nontransgenic rats colonized with anaerobic bacteria served as negative controls. Although preventive metronidazole significantly attenuated colitis in transgenic rats and DSS-treated mice, it had no therapeutic benefit once colitis was established. Ciprofloxacin also partially prevented but did not treat colitis in B27 transgenic rats. In both animal models vancomycin-imipenem most effectively prevented and treated colitis. Germfree transgenic rats reconstituted with enteric bacteria grown under anaerobic conditions had more aggressive colitis than those associated with aerobic bacteria. These results suggest that a subset of resident luminal bacteria induces colitis, but that a complex interaction of commensal aerobic and anaerobic bacteria provides the constant antigenic drive for chronic immune-mediated colonic inflammation. PMID:11254584

  1. Bacterial profile and their antimicrobial resistance pattern in an intensive care unit of a tertiary care hospital in Dhaka

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    Lovely Barai


    Full Text Available Critically ill patients admitted in intensive care units (ICU are always at a higher risk of developing infections with various antibiotic resistant organisms. The objective of this study was to know the antibiotic resistance pattern of the common isolates from blood, urine, respiratory secretions and pus/wound swab of patients admitted in ICU at BIRDEM (Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorder hospital, during a one year period from March 2006 to February 2007. A total of 1660 samples were analyzed. Growth was obtained in 34% of the samples yielding 632 organisms. The major organism isolated were Pseudomonas sp. (29.1%, Acinetobacter sp. (27.5%, Candida sp. (12.8%, Escherichia coli (10.3% and Klebsiella sp. (9.7%. Staphylococcus aureus, Enterobacter sp, Citrobacter sp, Enterococcus sp, Providencia sp and Serratia sp accounted for 10.6% of the isolates. All the isolates were highly resistant (>80% to cephalosporins and fluoroquinolones. The frequency of third generation cephalosporin resistant E. coli, Klebsiella and imipenem resistant Pseudomonas and Acinetobacter were >50%. Acinetobacter was remarkably resistant to most antibiotics including imipenem (>70% resistant, but most of the members of the Enterobacteriacae group showed maximum sensitivity to imipenem (50%-94%. The findings of this study might help clinicians to formulate their first line empirical antibiotic treatment regimens for the patients admitted in ICUs. Ibrahim Med. Coll. J. 2010; 4(2: 66-69

  2. In vitro prevention of Pseudomonas aeruginosa early biofilm formation with antibiotics used in cystic fibrosis patients. (United States)

    Fernández-Olmos, Ana; García-Castillo, María; Maiz, Luis; Lamas, Adelaida; Baquero, Fernando; Cantón, Rafael


    The ability of antibiotics used in bronchopulmonary infections in cystic fibrosis (CF) patients to prevent Pseudomonas aeruginosa early biofilm formation was studied using a biofilm microtitre assay with 57 non-mucoid P. aeruginosa isolates (44 first colonisers and 13 recovered during the initial intermittent colonisation stage) obtained from 35 CF patients. Minimum biofilm inhibitory concentrations (BICs) of levofloxacin, ciprofloxacin, imipenem, ceftazidime, tobramycin, colistin and azithromycin were determined by placing a peg lid with a formed biofilm onto microplates containing antibiotics. A modification of this protocol consisting of antibiotic challenge during biofilm formation was implemented in order to determine the biofilm prevention concentration (BPC), i.e. the minimum concentration able to prevent biofilm formation. The lowest BPCs were for fluoroquinolones, tobramycin and colistin and the highest for ceftazidime and imipenem. The former antibiotics had BPCs identical to or only slightly higher than their minimum inhibitory concentrations (MICs) determined by standard Clinical and Laboratory Standards Institute (CLSI) microdilution and were also active on formed biofilms as reflected by their low BIC values. In contrast, ceftazidime and imipenem were less effective for prevention of biofilm formation and on formed biofilms. In conclusion, the new BPC parameter determined in non-mucoid P. aeruginosa isolates recovered during early colonisation stages in CF patients supports early aggressive antimicrobial treatment guidelines in first P. aeruginosa-colonised CF patients. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  3. Pseudomonas pseudomallei, a common pathogen in Thailand that is resistant to the bactericidal effects of many antibiotics. (United States)

    Sookpranee, T; Sookpranee, M; Mellencamp, M A; Preheim, L C


    The purpose of this investigation was to identify newer antimicrobial agents that may be useful in the therapy of melioidosis. The in vitro susceptibilities of 199 clinical isolates of Pseudomonas pseudomallei to 22 antibiotics were determined by standard disk diffusion, and those to 13 antibiotics were determined by agar dilution. Over 90% of the isolates were susceptible to imipenem, piperacillin-tazobactam, piperacillin, ceftazidime, ticarcillin-clavulanate, ampicillin-sulbactam, and carumonam by both methods. Standard disk diffusion yielded unacceptably high false-susceptibility results with aztreonam, ciprofloxacin, and temafloxacin. Piperacillin, ceftazidime, imipenem, and ciprofloxacin were not bactericidal for three selected P. pseudomallei strains as determined by time-kill curve methods. Furthermore, addition of ciprofloxacin to piperacillin, ceftazidime, or imipenem did not enhance bactericidal activity. One hundred ninety-four strains showed weak beta-lactamase production that did not increase upon incubation with cefoxitin. These findings suggest that several newer antimicrobial agents may prove useful in the treatment of melioidosis. However, results of susceptibility studies involving P. pseudomallei and newer agents must be interpreted with caution.

  4. In vitro antibacterial activity and mechanism of action of J-111,225, a novel 1beta-methylcarbapenem, against transferable IMP-1 metallo-beta-lactamase producers. (United States)

    Nagano, R; Adachi, Y; Hashizume, T; Morishima, H


    IMP-1 beta-lactamase, a class B zinc metallo-enzyme encoded by the transferable bla(IMP) gene, is known to confer high-level resistance to carbapenems as well as to penicillins and cephalosporins. J-111, 225 is a novel 1beta-methylcarbapenem with a structurally unique side chain comprising a trans-3,5-disubstituted pyrrolidinylthio moiety at the C2 position. It inhibited 17 Serratia marcescens and two Pseudomonas aeruginosa IMP-1-producing clinical isolates at a concentration of 32 mg/L (range 4-32 mg/L). It showed synergy with imipenem against IMP-1-producing S. marcescens BB5886 and P. aeruginosa GN17203 with minimal FIC indices of 0.38 and 0.5, respectively. J-111,225 was more resistant than imipenem to hydrolysis by class B metallo-beta-lactamases. In kinetic studies, J-111,225 inhibited the IMP-I enzyme with a K(i) of 0.18 microM when imipenem was used as a substrate. In contrast, J-111,225 was the substrate for hydrolysis by other class B beta-lactamases such as Bacteroides fragilis CcrA, Stenotrophomonas maltophilia L1 and Bacillus cereus type II enzyme with respective K(m) values of 11, 10 and 148 microM. The greater antibacterial activity of J-111,225 against IMP-1-producing bacteria may result from its unique interaction with the beta-lactamase.

  5. Trends in antimicrobial susceptibility in UK centres: the MYSTIC Programme (1997-2002). (United States)

    Masterton, Robert G; Turner, Philip J


    Trends in antimicrobial susceptibilities in three UK centres participating in the MYSTIC Programme were examined from 1997 to 2002. Isolates were tested using standard methodology to determine the susceptibility breakpoints of meropenem and several other antimicrobial agents including imipenem, ceftazidime, piperacillin/tazobactam, ciprofloxacin and gentamicin. Data are grouped in 2-year blocks. The carbapenems were the most active agents tested against the Enterobacteriaceae (99-100% and 98-100% susceptibility to meropenem and imipenem, respectively) and non-fermenters, including Pseudomonas spp. and Acinetobacter spp. With the exception of susceptibility to ciprofloxacin, which decreased among Enterobacteriaceae at the end of the 6-year period, all antibiotics tested retained their levels of activity. The proportion of extended-spectrum beta-lactamase (ESBL)- and AmpC-producing Enterobacteriaceae increased during the study (4.8% and 11.3% in 1997-1998; 7.4% and 16.7% in 2001-2002, respectively). Both meropenem and imipenem retained their potency against these ESBL- and AmpC-producing isolates (100% for all time periods). All the other antimicrobial agents tested had much lower susceptibility against these resistant isolates and this decreased further over the 6-year period, with the exception of tazobactam, which maintained its low levels. Although all antibiotics tested retained acceptable activity, the carbapenems remained the most active antimicrobial agents against Gram-negative bacteria, including ESBL- and AmpC-producing isolates.

  6. Evolução da resistência de Pseudomonas aeruginosa e Acinetobacter baumannii em unidades de terapia intensiva

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    Marciano de Sousa Nóbrega


    Full Text Available Este estudo objetivou descrever o perfil de susceptibilidade de A. baumannii e P. aeruginosa, analisar a tendência à resistência bacteriana e o consumo de antimicrobianos. Pesquisa retrospectiva, descritiva e transversal desenvolvida nas unidades de terapia intensiva para adultos em um hospital público de ensino de grande porte, conveniado com o Sistema Único de Saúde. Foram identificados 121 casos de infecções por P. aeruginosa e A. baumannii. A taxa média inicial de resistência foi alta para ambos os microrganismos. Houve um aumento significativo na resistência para amicacina em A. baumannii. Nas infeções por P. aeruginosa ouve aumento no consumo de amicacina, imipenem e piperacilina-tazobactam e imipenem nas infecções por A. baumannii. Não houve correlação entre a resistência bacteriana e o consumo de antimicrobianos. A mortalidade e o tempo de permanência foram maiores no grupo em estudo e a resistência bacteriana foi elevada. Houve aumento no consumo de amicacina, imipenem e piperacilina-tazobactam.


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    I. I. Shilnikova


    Full Text Available In this study 122 strains of strictly anaerobic gram-negative rods Bacteroides, Prevotella and Fusobacterium, isolated from cancer patients between 2004 and 2014 were analyzed. The most common strains were B. fragilis (55 % followed by Prevotella (34.4 % and Fusobacterium spp (10.6 %. The species identification was carried out by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS. Among the B. fragilis group strains, B. fragilis, B. thetaiotaomicron, B. ovatus and B. vulgatus were isolated most frequently. Among Prevotella species, the most frequently isolated species were P. buccae, P. buccalis, P. oris, P. denticola and P. nigrescens, and 77 % of the Fusobacterium spp. were F. nucleatum. Susceptibilities of the isolates to antimicrobial agents were determined by the E-test methodology. The percentage of the susceptibility of B. fragilis group isolates were: metronidazole, 97 %; imipenem, 95.5 %; amoxicillin/clavulanate, 95.5 % and clindamycin, 77.6 %. Three B. fragilis isolates proved to be multidrug-resistant (simultaneously to imipenem, amoxicillin/ clavulanate and metronidazole or clindamycin. All Prevotella isolates were susceptible to imipenem and amoxicillin/clavulanate, whereas 78.6 % of the pigmented Prevotella species and 46.4 % of the non-pigmented species were resistant to penicillin. The number of strains susceptibility to metronidazole and clindamycin were 93 % and 88 %, respectively. All Fusobacterium strains were sensitive to all tested antibiotics, including penicillin.

  8. Characterization of Pseudomonas aeruginosa with discrepant carbapenem susceptibility profile. (United States)

    Pragasam, Agila K; Raghanivedha, M; Anandan, Shalini; Veeraraghavan, Balaji


    Pseudomonas aeruginosa is the most common nosocomial pathogen, notorious for its multidrug resistance and causes life threatening infections. Carbapenems were considered as the last resort of drugs for the treatment of multi drug resistant P. aeruginosa infections. The emergence of resistance to carbapenems limits its use for treatment. Unlike other organisms, in P. aeruginosa intrinsic/chromosomal mediated resistance mechanisms plays a major role for carbapenem resistance rather than the carbapenemases. Carbapenemase producing organisms becomes resistant to both imipenem and meropenem. However, in our clinical settings, we have observed rare carbapenem resistant phenotypes such as imipenem resistant but meropenem susceptible (IRMS) and meropenem resistant but imipenem susceptible (MRIS) phenotypes. Thus we have chosen these rare phenotypes to look for the respective resistance mechanisms by phenotypic and molecular methods. From this study we found that, IRMS is primarily due to the mutations across various regions in the loops of oprD gene and MRIS is due to the over expression of mexAB efflux pumps. This study results confirms that, this rare phenotypes are due to the intrinsic/chromosomal mediated mechanisms, which occurred due to the antibiotic selection pressure. This study also provided data concerning alterations in outer membrane permeability which is often associated with the increased levels of antibiotic efflux. Consequently, this study provided the prevalence of the various resistance mechanisms that have deployed by the organism to resist antibiotics through different phenotypes.

  9. Cathelicidin peptide sheep myeloid antimicrobial peptide-29 prevents endotoxin-induced mortality in rat models of septic shock. (United States)

    Giacometti, Andrea; Cirioni, Oscar; Ghiselli, Roberto; Mocchegiani, Federico; D'Amato, Giuseppina; Circo, Raffaella; Orlando, Fiorenza; Skerlavaj, Barbara; Silvestri, Carmela; Saba, Vittorio; Zanetti, Margherita; Scalise, Giorgio


    The present study was designed to investigate the antiendotoxin activity and therapeutic efficacy of sheep myeloid antimicrobial peptide (SMAP)-29, a cathelicidin-derived peptide. The in vitro ability of SMAP-29 to bind LPS from Escherichia coli 0111:B4 was determined using a sensitive limulus chromogenic assay. Two rat models of septic shock were performed: (1) rats were injected intraperitoneally with 1 mg E. coli 0111:B4 LPS and (2) intraabdominal sepsis was induced via cecal ligation and single puncture. All animals were randomized to receive parenterally isotonic sodium chloride solution, 1 mg/kg SMAP-29, 1 mg/kg polymyxin B or 20 mg/kg imipenem. The main outcome measures were: abdominal exudate and plasma bacterial growth, plasma endotoxin and tumor necrosis factor-alpha concentrations, and lethality. The in vitro study showed that SMAP-29 completely inhibited the LPS procoagulant activity at approximately 10 microM peptide concentration. The in vivo experiments showed that all compounds reduced the lethality when compared with control animals. SMAP-29 achieved a substantial decrease in endotoxin and tumor necrosis factor-alpha plasma concentrations when compared with imipenem and saline treatment and exhibited a slightly lower antimicrobial activity than imipenem. No statistically significant differences were noted between SMAP-29 and polymyxin B. SMAP-29, because of its double antiendotoxin and antimicrobial activities, could be an interesting compound for septic shock treatment.

  10. Systematic review and meta-analysis of antimicrobial treatment effect estimation in complicated urinary tract infection. (United States)

    Singh, Krishan P; Li, Gang; Mitrani-Gold, Fanny S; Kurtinecz, Milena; Wetherington, Jeffrey; Tomayko, John F; Mundy, Linda M


    Noninferiority trial design and analyses are commonly used to establish the effectiveness of a new antimicrobial drug for treatment of serious infections such as complicated urinary tract infection (cUTI). A systematic review and meta-analysis were conducted to estimate the treatment effects of three potential active comparator drugs for the design of a noninferiority trial. The systematic review identified no placebo trials of cUTI, four clinical trials of cUTI with uncomplicated urinary tract infection as a proxy for placebo, and nine trials with reports of treatment effect estimates for doripenem, levofloxacin, or imipenem-cilastatin. In the meta-analysis, the primary efficacy endpoint of interest was the microbiological eradication rate at the test-of-cure visit in the microbiological intent-to-treat population. The estimated eradication rates and corresponding 95% confidence intervals (CI) were 31.8% (26.5% to 37.2%) for placebo, 81% (77.7% to 84.2%) for doripenem, 79% (75.9% to 82.2%) for levofloxacin, and 80.5% (71.9% to 89.1%) for imipenem-cilastatin. The treatment effect estimates were 40.5% for doripenem, 38.7% for levofloxacin, 34.7% for imipenem-cilastatin, and 40.8% overall. These treatment effect estimates can be used to inform the design and analysis of future noninferiority trials in cUTI study populations.

  11. Phenotypic detection of Klebsiella pneumoniae carbapenemase among burns patients: first report from Iran. (United States)

    Rastegar Lari, Abdolaziz; Azimi, Leila; Rahbar, Mohammad; Fallah, Fatemeh; Alaghehbandan, Reza


    Resistance to antimicrobial agents such as carbapenems among enterobacteriacea has been increasing, especially in Klebsiella pneumonia that produces variety of enzymes including Klebsiella pneumoniae carbapenemase (KPC). This study is the first report of its kind investigating the resistance to carbapenems among burns patients in Iran. During a 6-month period, 28 hospitalized burn patients who required to be placed on broad spectrum antibiotics were studied. Isolated species identified by routine biochemical test. Susceptibility testing for these species was performed by recommended the CLSI guidelines method. The tested antibiotics included cefotaxime, cefepime, aztreonam, imipenem, amoxicillin+clavulonic acid, gentamicin, amikacin, tobramycin, tetracycline, and trimethoprim-sulfamethoxazole, and chloramphenicol. For determination of KPC in phenotypical forms, Modified Hodge Test was utilized as per CLSI recommendation. Thirty-five Klebsiella spp. were isolated from 28 hospitalized patients. Nineteen out of 35 Klebsiella isolates were resistant to imipenem and that all of them had positive KPC. Nine of imipenem resistant isolates were also resistant to all tested antibiotics. Mortality rate among patients with positive KPC was 33%. High rate of multi-drug resistant (MDR) strains in isolates with positive KPC is a major challenge in Iran and that it could cause an increase in both mortality and morbidity among burn patients. Thus, appropriate infection control measures and guidelines are needed to prevent such infections among burn patients. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  12. Evaluation of the in vitro ocular toxicity of the fortified antibiotic eye drops prepared at the Hospital Pharmacy Departments

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    Anxo Fernández-Ferreiro


    Full Text Available The use of parenteral antibiotic eye drop formulations with non-marketed compositions or concentrations, commonly called fortified antibiotic eye drops, is a common practice in Ophthalmology in the hospital setting. The aim of this study was to evaluate the in vitro ocular toxicity of the main fortified antibiotic eye drops prepared in the Hospital Pharmacy Departments. We have conducted an in vitro experimental study in order to test the toxicity of gentamicin, amikacin, cefazolin, ceftazidime, vancomycin, colistimethate sodium and imipenem-cilastatin eye drops; their cytotoxicity and acute tissue irritation have been evaluated. Cell-based assays were performed on human stromal keratocytes, using a cell-based impedance biosensor system [xCELLigence Real-Time System Cell Analyzer (RTCA], and the Hen’s Egg Test for the ocular irritation tests. All the eye drops, except for vancomycin and imipenem, have shown a cytotoxic effect dependent on concentration and time; higher concentrations and longer exposure times will cause a steeper decline in the population of stromal keratocytes. Vancomycin showed a major initial cytotoxic effect, which was reverted over time; and imipenem appeared as a non-toxic compound for stromal cells. The eye drops with the highest irritating effect on the ocular surface were gentamicin and vancomycin. Those antibiotic eye drops prepared at the Hospital Pharmacy Departments included in this study were considered as compounds potentially cytotoxic for the ocular surface; this toxicity was dependent on the concentration used

  13. Nonfermentative gram-negative microorganisms isolated from intensive care units and their resistance profiles in a training and research hospital

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    Fulya Bayındır Bilman


    Full Text Available Objective: The aim of this study was to determine the pathogenic agents, which have been isolated in ICUs and determine their antimicrobial susceptibility in the first two years of our hospital. Methods: A total 368 strains (194 Pseudomonas aeruginosa, and 174 Acinetobacter baumannii that were considered as an infectious agent and isolated from different clinical samples of hospitalized patients in intensive care units between January 2011 and December 2012 were included in the study. Conventional methods and automatized system were used for the identification and antibiotic susceptibility of the isolates with according to guidelines of Clinical and Laboratory Standarts Institute (CLSI. Imipenem and meropenem resistance has been confirmed by the E test method and interpreted according to CLSI. Results: Resistance rates of P.aeruginosa strains were as follows: Meropenem 35%, imipenem 36%, cefepim 21%, ceftazidim and ciprofloxacin 29%, gentamicin 33%, piperacilin/tazobactam 35%, amikacin 37%. Resistance rates of A.baumannii strains were as follows: Meropenem 85%, imipenem 87%, amikacin 22%, trimethoprim/sulfamethoxazole 25%, gentamicin 46%, piperacilin/tazobactam 54%, ampicilin/sulbactam 59%, cefepim 64%, ciprofloxacin 71%, ceftazidim 83%. Conclusion: Increased carbapenem resistance in our ICUs demonstrates importance of antimicrobial susceptibility tests. The antibiotic susceptibility tests should be surveyed continuously to avoid the spread of intensive care unit isolates carrying high level antibiotic resistance for better achievement of treatment regimens. J Clin Exp Invest 2014; 5 (3: 391-396

  14. [Pathogenic microbes of biliary infection and their resistance to antibiotics]. (United States)

    Zhu, J; Tang, Y; Song, X; Wang, Y


    To understand the change of the main pathogenic microbes of biliary infection and their resistance rates to 12 antibiotics so as to instruct rational application of antibiotics clinically. All isolates were identified by analytic products incorporation (API) bioMerieux. The susceptibility of antibiotics to 470 pathogenic microbes was tested by minimal inhibition concentration (MIC). There were 470 pathogenic microbes with positive biliary culture. The percentage of Escherichia coli, intestinal cocci and Klebsiella pneumoniae was 129 (27.4%), 82 (17.4%) and 76 (16.2%), respectively. In the resistance rates of the gram negative bacilli to 12 antibiotics, the lowest was 4.0% for imipenem followed by. 14.1% Ceftazidime and 16.9% amikacin. In the resistant rates of the gram positive cocci to 12 antibiotics, and had the lowest rate was 6.0% for vancomycin and 16.4% for imipenem. The main pathogenic microbes of biliary infection were Escherichia coli, intestinal cocci and Klebsiella pneumoniae. Imipenem is the first used for biliary infection in dealing with multiresistant intestinal cocci.

  15. Exposure to β-lactams results in the alteration of penicillin-binding proteins in Clostridium perfringens. (United States)

    Park, Miseon; Rafii, Fatemeh


    Clostridium perfringens causes a variety of mild to severe infections in humans and other animals. A decrease in the affinity of penicillin-binding protein (PBP) transpeptidases for β-lactams is considered one of the mechanisms of β-lactam resistance in bacteria. Two strains of C. perfringens isolated from bovines and one isolated from a chicken, which had decreased susceptibility to β-lactams, had variations in the amino acid sequences of the central penicillin-binding regions of the PBPs. β-Lactam-resistant mutants of another C. perfringens strain, ATCC 13124, were selected in vitro to determine the effects of exposure to β-lactams on the PBP genes. Cultures of the wild type rapidly developed resistance to penicillin G, cephalothin and ceftriaxone. The susceptibilities of all of the selected mutants to some other β-lactams also decreased. The largest PBP found in C. perfringens, CPF_2395, appeared to be the primary target of all three drugs. Strain resistant to penicillin G had mutation resulting in the substitution of one amino acid within the central penicillin-binding/transpeptidase domain, but the ceftrioxane and cephalothin-resistant strains had mutations resulting in the substitution of two amino acids in this region. The cephalothin-resistant mutant also had additional mutations in the CPF_0340 and CPF_2218 genes in this critical region. No other mutations were observed in the three other PBPs of the in vitro resistant mutants. Resistance development also altered the growth rate and cell morphology of the mutants, so in addition to the PBPs, some other genes, including regulatory genes, may have been affected during the interaction with β-lactam antibiotics. This is the first study showing the effects of β-lactam drugs on the substitution of amino acids in PBPs of C. perfringens and points to the need for studies to detect other unknown alterations affecting the physiology of resistant strains. Published by Elsevier Ltd.

  16. Effect of administration of vitamin E, selenium and antimicrobial therapy on incidence of mastitis, productive and reproductive performances in dairy cows

    Directory of Open Access Journals (Sweden)

    M.N. Hoque


    Full Text Available Administration of vitamin, mineral and antimicrobials at the end of lactation plays potential role in preventing mastitis in dairy cows. A total of 255 cows dividing into five groups (A = 50, B = 50, C = 50, D = 50 and E = 55 at their late gestation period were selected to explore the effect of vitamin E, selenium and antimicrobial therapy on mastitis incidence, their productive and reproductive performances. Each cow of group A received α-tocopherol + sodium selenite orally daily for last 30 days before calving, while each cow of group B, C and D was treated with α-tocopherol + sodium selenite intramuscular injection, procaine penicillin + neomycin sulfate, and dicloxacillin sodium intramammary infusions at Day 30–20 before calving, respectively. Group E cows served as untreated control. California mastitis test (CMT revealed that 70.0%, 76.0%, 84.0% and 100.0% cows in group A, B, C and D, respectively were free from new intramammary infections (IMIs during early lactation period. The bacteriological results showed highest IMIs rates (76.3% in group E and lowest IMIs (2.0% in group D (P < 0.05. Staphylococcus aureus and Escherichia coli were the most predominant udder pathogens in all groups except group D (only CNS. The mean IMIs incidence (20.5% was significantly lower in treated cows (P < 0.001. The treated cows had higher cure rates (81.9% than control cows (23.1% and overall efficacy of treatments on cure rates was 71.8% for all mastitis pathogens (P < 0.0001. The productive and reproductive performances of the treated cows at postpartum and early lactation period remained always higher than their non-treated counterparts (P < 0.001. A number of cow and herd related factors were identified to be significantly associated with mastitis (P < 0.001. The results concluded that antimicrobial therapy had more beneficial effect in preventing mastitis over vitamin–mineral administration and intramammary infusion

  17. Optimization of Synergistic Combination Regimens against Carbapenem- and Aminoglycoside-Resistant Clinical Pseudomonas aeruginosa Isolates via Mechanism-Based Pharmacokinetic/Pharmacodynamic Modeling. (United States)

    Yadav, Rajbharan; Bulitta, Jürgen B; Nation, Roger L; Landersdorfer, Cornelia B


    Optimizing antibiotic combinations is promising to combat multidrug-resistant Pseudomonas aeruginosa This study aimed to systematically evaluate synergistic bacterial killing and prevention of resistance by carbapenem and aminoglycoside combinations and to rationally optimize combination dosage regimens via a mechanism-based mathematical model (MBM). We studied monotherapies and combinations of imipenem with tobramycin or amikacin against three difficult-to-treat double-resistant clinical P. aeruginosa isolates. Viable-count profiles of total and resistant populations were quantified in 48-h static-concentration time-kill studies (inoculum, 10(7.5) CFU/ml). We rationally optimized combination dosage regimens via MBM and Monte Carlo simulations against isolate FADDI-PA088 (MIC of imipenem [MICimipenem] of 16 mg/liter and MICtobramycin of 32 mg/liter, i.e., both 98th percentiles according to the EUCAST database). Against this isolate, imipenem (1.5× MIC) combined with 1 to 2 mg/liter tobramycin (MIC, 32 mg/liter) or amikacin (MIC, 4 mg/liter) yielded ≥2-log10 more killing than the most active monotherapy at 48 h and prevented resistance. For all three strains, synergistic killing without resistance was achieved by ≥0.88× MICimipenem in combination with a median of 0.75× MICtobramycin (range, 0.032× to 2.0× MICtobramycin) or 0.50× MICamikacin (range, 0.25× to 0.50× MICamikacin). The MBM indicated that aminoglycosides significantly enhanced the imipenem target site concentration up to 3-fold; achieving 50% of this synergistic effect required aminoglycoside concentrations of 1.34 mg/liter (if the aminoglycoside MIC was 4 mg/liter) and 4.88 mg/liter (for MICs of 8 to 32 mg/liter). An optimized combination regimen (continuous infusion of imipenem at 5 g/day plus a 0.5-h infusion with 7 mg/kg of body weight tobramycin) was predicted to achieve >2.0-log10 killing and prevent regrowth at 48 h in 90.3% of patients (median bacterial killing, >4.0 log10 CFU

  18. Noncovalent Interaction Energies in Covalent Complexes: TEM-1 beta-Lactamase and beta-Lactams

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    Wang, Xiaojun; Minasov, George; Shoichet, Brian K. (NWU)


    The class A {beta}-lactamase TEM-1 is a key bacterial resistance enzyme against {beta}-lactam antibiotics, but little is known about the energetic bases for complementarity between TEM-1 and its inhibitors. Most inhibitors form a covalent adduct with the catalytic Ser70, making the measurement of equilibriumconstants, and hence interaction energies, technically difficult. This study evaluates noncovalent interactions withincovalent complexes by examining the differential stability of TEM-1 and its inhibitor adducts. The thermal denaturation of TEM-1 follows a two-state, reversible model with a melting temperature (T{sub m}) of 51.6 C and a van't Hoff enthalpy of unfolding ({Delta}H{sub VH}) of 146.2 kcal/mol at pH 7.0. The stability of the enzyme changes on forming an inhibitor adduct. As expected, some inhibitors stabilize TEM-1; transition-state analogues increase the T{sub m} by up to 3.7 C(1.7 kcal/mol). Surprisingly, all {beta}-lactam covalent acyl-enzyme complexes tested destabilize TEM-1 significantly relative to the apoenzyme. For instance, the clinically used inhibitor clavulanic acid and the {beta}-lactamase-resistant {beta}-lactams moxalactam and imipenem destabilize TEM-1 by over 2.6 C (1.2 kcal/mol) in their covalent adducts. Based on the structure of the TEM-1/imipenem complex (Maveyraud et al., J Am Chem Soc 1998;120:9748-52), destabilization by moxalactam and imipenem is thought to be caused by a steric clash between the side-chain of Asn132 and the 6(7)-{alpha} group of these {beta}-lactams. To test this hypothesis, the mutant enzyme N132A was made. In contrast with wild-type, the covalent complexes between N132A and both imipenem and moxalactam stabilize the enzyme, consistent with the hypothesis. To investigate the structural bases of this dramatic change instability, the structure of N132A/imipenem was determined by X-ray crystallography. In the complex with N132A, imipenemadopts a very different conformation from that observed in the wild

  19. [Analysis of drug resistance of Pseudomonas aeruginosa and use of antibiotics in burn wards during 6 years]. (United States)

    Dou, Yi; Zhang, Qin


    To study the distribution characteristics of pathogens, the drug resistance of Pseudomonas aeruginosa (PA), and the use of antibiotics against Gram negative bacilli (GNB) in burn wards, so as to provide a guide for future treatment. A total of 2 758 strains of pathogens were isolated from specimens of wound excretion, venous catheter attachment, blood, stool, urine, and sputum from 7 441 patients hospitalized in our burn wards from January 2007 to December 2012. After being identified by API strips and automatic microorganism identification and drug sensitivity analyzer, drug resistance of all the pathogens to 13 antibiotics commonly used in clinic, including amikacin, cefoperazone/sulbactam, ceftazidime, etc., was tested by K-B paper disk diffusion method. The defined daily doses per 1 000 patient-day of 5 antibiotics including amikacin, cefoperazone/sulbactam, ceftazidime, imipenem, and ciprofloxacin each year was set as use intensity. The WHONET 5.6 software was used to analyze the distribution of pathogens and the drug resistance of PA to 13 antibiotics. The SPSS 19.0 software was used to analyze the relation between changes in drug-resistant rates of PA to 13 antibiotics and year, the relation between the proportion of PA in all the pathogens and the use intensity of 5 antibiotics commonly used against GNB, and the relation between the use intensity of ciprofloxacin and the change in drug-resistant rates of PA to amikacin, cefoperazone/sulbactam, and imipenem with Pearson correlation analysis. (1) In 6 years, Staphylococcus aureus ranked the first with the highest proportion (31%, 865/2 758). The proportion of PA increased to tie in with Acinetobacter baumannii (both accounting for 17%, 458/2 758), both taking the second place. (2) Drug-resistant rates of PA to amikacin, gentamicin, aztreonam, piperacillin, cefoperazone, cefepime, piperacillin/tazobactam, cefoperazone/sulbactam, imipenem, and meropenem were significantly increased and positively correlated

  20. Eradication of multidrug-resistant Acinetobacter baumannii in a female patient with total hip arthroplasty, with debridement and retention: a case report

    Directory of Open Access Journals (Sweden)

    Beieler Alison M


    Full Text Available Abstract Introduction Multidrug-resistant Acinetobacter baumannii has become a significant cause of healthcare-associated infections, but few reports have addressed Acinetobacter baumannii infections associated with orthopedic devices. The current recommended treatment for complicated infections due to orthopedic devices, including resistant gram-negative rods, consists of antimicrobial therapy with debridement and removal of implants. Case presentation The patient, a 47-year-old woman, had previously had a prior total hip arthroplasty at 16 years of age for a complex femoral neck fracture, and multiple subsequent revisions. This time, she underwent a fifth revision secondary to pain. Surgery was complicated by hypotension resulting in transfer to the intensive care unit and prolonged respiratory failure. She received peri-operative cefazolin but postoperatively developed surgical wound drainage requiring debridement of a hematoma. Cultures of this grew ampicillin-sensitive Enterococcus and Acinetobacter baumannii (sensitive only to amikacin and imipenem. The patient was started on imipenem. Removal of the total hip arthroplasty was not recommended because of the recent surgical complications, and the patient was eventually discharged home. She was seen weekly for laboratory tests and examinations and, after 4 months of therapy, the imipenem was discontinued. She did well clinically for 7 months before recurrent pain led to removal of the total hip arthroplasty. Intra-operative cultures grew ampicillin-sensitive Enterococcus and coagulase-negative Staphylococcus but no multidrug-resistant Acinetobacter baumannii. The patient received ampicillin for 8 weeks and had not had recurrent infection at the time of writing, 37 months after discontinuing imipenem. Conclusion We describe the successful treatment of an acute infection from multidrug-resistant Acinetobacter baumannii with debridement and retention of the total hip arthroplasty, using

  1. Absence of convulsive liability of doripenem, a new carbapenem antibiotic, in comparison with beta-lactam antibiotics. (United States)

    Horiuchi, Masahito; Kimura, Megumi; Tokumura, Miwa; Hasebe, Nobuyoshi; Arai, Tohko; Abe, Kohji


    beta-Lactam antibiotics have been suggested to have some degree of convulsive activity and neurotoxicity in experimental animals as well as in clinical situations. We examined the convulsive activities of a new carbapenem antibiotic, (+)-(4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-3-[[(3S,5S)-5-[(sulfamoylamino)methyl]-3-pyrrolidinyl]thio]-1-azabicyclo[3.2.0]hept-2-ene-2-carboxic acid monohydrate (doripenem) using several animals and compared them with beta-lactam antibiotics. In intravenous (IV) injection studies, imipenem/cilastatin, at 400/400mg/kg produced seizure discharges on electroencephalogram (EEG) accompanied with clonic convulsions in rats. Meropenem showed only wet dog shaking behavior at 200 and 400mg/kg. Doripenem caused no changes in the EEG and behavior in rats at 400mg/kg. Imipenem/cilastatin IV potentiated the pentylenetetrazol (PTZ)-induced convulsions in mice at 250/250 mg/kg, while meropenem, panipenem/betamipron, cefazolin or doripenem did not cause any marked effects at up to 500 mg/kg. In mouse intracerebroventricular (ICV) injection studies, imipenem, panipenem and cefazolin induced clonic convulsions in a dose-dependent manner in mice. Doripenem and meropenem did not induce convulsions at up to 100 microg/mouse. In dog ICV injection studies, imipenem produced generalized seizure discharge with clonic convulsions at 100 microg/dog. Meropenem also produced spikes or seizure discharges at 100, 300 and 1,000 microg/dog. However, doripenem had no effects on the EEG and behavior in dogs at any doses. In in vitro binding studies, imipenem, panipenem, cefazolin and meropenem inhibited [(3)H]muscimol binding to the GABA(A) receptor in mouse brain homogenates while doripenem did not cause any inhibition at up to 10mM. In addition, doripenem had no influence on the anti-convulsant actions of valproic acid in the PTZ- or bicuculine-induced convulsive model. These results clearly indicate that doripenem has no convulsive activity, suggesting

  2. Comparison of beta-lactam regimens for the treatment of gram-negative pulmonary infections in the intensive care unit based on pharmacokinetics/pharmacodynamics. (United States)

    Burgess, David S; Frei, Christopher R


    This study utilized pharmacokinetics/pharmacodynamics to compare beta-lactam regimens for the empirical and definitive treatment of gram-negative pulmonary infections in the ICU. Susceptibility data were extracted from the 2002 Intensive Care Unit Surveillance System (ISS) and pharmacokinetic parameters were obtained from published human studies. Monte Carlo simulation was used to model the free percent time above the MIC (free %T > MIC) for 18 beta-lactam regimens against all gram-negative isolates, Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii. The cumulative fraction of response (CFR) was determined for bacteriostatic and bactericidal targets (free %T > MIC): penicillins (> or = 30/50%), cephalosporins/monobactams (> or = 40/70%) and carbapenems (> or = 20/40%). The 2002 ISS database contained MICs for 2408 gram-negative isolates including 1430 Enterobacteriaceae, 799 P. aeruginosa, and 179 A. baumannii. Imipenem had the highest percentage susceptible for all gram-negatives, Enterobacteriaceae and A. baumannii, while piperacillin/tazobactam had the highest percentage susceptible for P. aeruginosa. For empirical therapy, imipenem 0.5 g every 6 h, cefepime 2 g every 8 h and ceftazidime 2 g every 8 h demonstrated the highest CFR. For definitive therapy, imipenem 0.5 g every 6 h, ertapenem 1 g daily and cefepime 2 g every 8 h, cefepime 1 g every 8 h and cefepime 1 g every 12 h had the highest bactericidal CFR against Enterobacteriaceae; ceftazidime 2 g every 8 h, cefepime 2 g every 8 h, piperacillin/tazobactam 3.375 g every 4 h, ceftazidime 1 g every 8 h and aztreonam 1 g every 8 h against P. aeruginosa; and imipenem 0.5 g every 6 h, ticarcillin/clavulanate 3.1 g every 4 h, ceftazidime 2 g every 8 h, cefepime 2 g every 8 h and ticarcillin/clavulanate 3.1 g every 6 h against A. baumannii. Based on pharmacokinetics/pharmacodynamics, imipenem 0.5 g every 6 h, cefepime 2 g every 8 h and ceftazidime 2 g every 8 h should be the preferred beta

  3. Comparative Activity of Carbapenem Testing (COMPACT) study in Germany. (United States)

    Valenza, Giuseppe; Seifert, Harald; Decker-Burgard, Sabine; Laeuffer, Joerg; Morrissey, Ian; Mutters, Reinier


    The aim of this study was to determine the current susceptibility of hospital isolates of contemporary Gram-negative pathogens to the carbapenems doripenem, imipenem and meropenem. Between May and October 2008, seven centres in Germany were invited to collect and submit Pseudomonas aeruginosa, Enterobacteriaceae and other Gram-negative bacterial Intensive Care Unit (ICU)/non-ICU isolates from patients with complicated intra-abdominal infections (cIAIs), bloodstream infections (BSIs) or nosocomial pneumonia (NP). Susceptibility was determined at each centre by Etest. A central laboratory performed species confirmation as well as limited susceptibility and quality control testing. In total, 363 isolates were collected, comprising 46.0% Enterobacteriaceae, 45.2% P. aeruginosa, 4.7% Acinetobacter spp. and 4.1% other Gram-negatives. Most isolates (47.9%) were collected from NP, 32.8% were from cIAIs and 19.3% from BSIs; 57.3% were obtained from ICU patients. The MIC(90) values (minimum inhibitory concentration for 90% of the isolates) for doripenem, meropenem and imipenem were, respectively, 4, 16 and 32 mg/L against P. aeruginosa, 0.06, 0.06 and 0.5mg/L against Enterobacteriaceae and ≥ 64 mg/L for each carbapenem against other Gram-negative isolates. Using European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, 81.1%, 75.6% and 79.3% of P. aeruginosa were susceptible to doripenem, imipenem and meropenem, respectively. Against all pathogens combined, MIC(90) values for ICU versus non-ICU isolates, respectively, were 4 mg/L vs. 1mg/L for doripenem, 8 mg/L vs. 1mg/L for meropenem and ≥ 64 mg/L vs. 8 mg/L for imipenem. Doripenem showed comparable activity against P. aeruginosa from patients with BSIs, cIAIs or NP. Similar findings were observed for Enterobacteriaceae and other Gram-negatives, including Acinetobacter spp. Doripenem generally showed similar or slightly better activity than meropenem and better activity than imipenem against Gram

  4. Biochemical Characterization of the FEZ-1 Metallo-β-Lactamase of Legionella gormanii ATCC 33297T Produced in Escherichia coli (United States)

    Mercuri, Paola Sandra; Bouillenne, Fabrice; Boschi, Letizia; Lamotte-Brasseur, Josette; Amicosante, Gianfranco; Devreese, Bart; van Beeumen, Jozef; Frère, Jean-Marie; Rossolini, Gian Maria; Galleni, Moreno


    The blaFEZ-1 gene coding for the metallo-β-lactamase of Legionella (Fluoribacter) gormanii ATCC 33297T was overexpressed via a T7 expression system in Escherichia coli BL21(DE3)(pLysS). The product was purified to homogeneity in two steps with a yield of 53%. The FEZ-1 metallo-β-lactamase exhibited a broad-spectrum activity profile, with a preference for cephalosporins such as cephalothin, cefuroxime, and cefotaxime. Monobactams were not hydrolyzed. The β-lactamase was inhibited by metal chelators. FEZ-1 is a monomeric enzyme with a molecular mass of 29,440 Da which possesses two zinc-binding sites. Its zinc content did not vary in the pH range of 5 to 9, but the presence of zinc ions modified the catalytic efficiency of the enzyme. A model of the FEZ-1 three-dimensional structure was built. PMID:11257043

  5. Biochemical characterization of the FEZ-1 metallo-beta-lactamase of Legionella gormanii ATCC 33297T produced in Escherichia coli. (United States)

    Mercuri, P S; Bouillenne, F; Boschi, L; Lamotte-Brasseur, J; Amicosante, G; Devreese, B; van Beeumen, J; Frère, J M; Rossolini, G M; Galleni, M


    The bla(FEZ-1) gene coding for the metallo-beta-lactamase of Legionella (Fluoribacter) gormanii ATCC 33297T was overexpressed via a T7 expression system in Escherichia coli BL21(DE3)(pLysS). The product was purified to homogeneity in two steps with a yield of 53%. The FEZ-1 metallo-beta-lactamase exhibited a broad-spectrum activity profile, with a preference for cephalosporins such as cephalothin, cefuroxime, and cefotaxime. Monobactams were not hydrolyzed. The beta-lactamase was inhibited by metal chelators. FEZ-1 is a monomeric enzyme with a molecular mass of 29,440 Da which possesses two zinc-binding sites. Its zinc content did not vary in the pH range of 5 to 9, but the presence of zinc ions modified the catalytic efficiency of the enzyme. A model of the FEZ-1 three-dimensional structure was built.

  6. Identification and antimicrobial susceptibility patterns of Staphylococcus spp. isolated from canine chronic otitis externa

    Directory of Open Access Journals (Sweden)

    Silva N.


    Full Text Available Swab samples obtained from 96 dogs with chronic otitis externa were cultured for the isolation of Staphylococcus species. Of 57 staphylococcal strains, 41 (72% were coagulase-negative (CNS. The identification of staphylococci strains was made by standard procedures for the routine identification of staphylococci in clinical practice. S. sciuri was the most frequent species isolated (22.8% from chronic otitis externa in dogs followed by S. intermedius (12.3%, S. auricularis (10.5% and S. aureus (8.8%. Three (5.2% CNS strains could not be identified. Bacterial isolates were susceptible to enrofloxacin, gentamicin, cephalothin, chloramphenicol and neomycin. Resistance was most common to penicillin G, oxacillin and ampicillin.

  7. In vitro activity of mastoparan-AF alone and in combination with clinically used antibiotics against multiple-antibiotic-resistant Escherichia coli isolates from animals. (United States)

    Lin, Chun-Hsien; Hou, Roger F; Shyu, Ching-Lin; Shia, Wei-Yau; Lin, Chuen-Fu; Tu, Wu-Chun


    The in vitro activity of mastoparan-AF, an amphipathic antimicrobial peptide isolated from the hornet venom of Vespa affinis, alone and in combination with various clinically used antibiotics, was investigated against 21 Escherichia coli isolates/strains. Most E. coli isolates tested were detected containing multiple-antimicrobial resistance genes. Antimicrobial activity of mastoparan-AF was measured by MIC, MBC, time-kill kinetic assay and chequerboard titration method. Mastoparan-AF exhibited potent antimicrobial activity against most multiple-antibiotic-resistant E. coli isolates at the concentrations ranging from 4 to 16 μg/ml. Combination studies showed that mastoparan-AF acts synergistically with certain antibiotics, i.e., cephalothin or gentamicin, against some multiple-antibiotic-resistant E. coli isolates. In conclusion, mastoparan-AF alone or in combination with other antibiotics could be promising as alternatives for combating multiple-antibiotic-resistant E. coli in future clinical applications. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Mixed-Ligand Nickel(II Complexes Containing Sulfathiazole and Cephalosporin Antibiotics: Synthesis, Characterization, and Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    J. R. Anacona


    (L1,4, x=1; L2,3, x=0; L = monoanion of cefazolin HL1, cephalothin HL2, cefotaxime HL3, ceftriaxone HL4 and [Ni(L5(stz]Cl (cefepime L5, which were characterized by physicochemical and spectroscopic methods. Their spectra indicated that cephalosporins are acting as multidentate chelating agents, via the lactam carbonyl and carboxylate and N-azomoieties. The complexes are insoluble in water and common organic solvents but soluble in DMSO, where the [Ni(L5(stz]Cl complex is 1 : 1 electrolyte. They probably have polymeric structures. They have been screened for antibacterial activity, and the results are compared with the activity of commercial cephalosporins.

  9. Antibiotic-resistant gram-negative bacilli in the sewage of the City of Concepcion, Chile. (United States)

    Martínez, M; Mondaca, M A; Zemelman, R


    Counts of total and of antibiotic-resistant heterotrophic Gram-negative bacteria were performed in samples collected from the main sewage effluent of the city of Concepcion, Chile, during an eleven month period in 1991-1992. Antibiotic resistance patterns (ARP) were determined and antibiotic resistance indexes (ARI) were calculated for some fermenting and nonfermenting strains of resistant bacteria. Ampicillin-resistant strains were the most frequent among fermenting bacteria, whereas those cephalothin-resistant were the most frequent among nonfermenting bacilli. These results correlate with the frequency of clinical use of both antibiotics in the community of Concepción. Higher values of ARI for nonfermenting bacilli are probably due to the natural intrinsic resistance of these microorganisms to several beta-lactam compounds. Since plasmid-coded resistance is frequent among enteric bacilli, the large number of resistant bacilli in sewage may be important in the natural dis-

  10. Susceptibility of Genital Mycoplasmas to Antimicrobial Agents (United States)

    Braun, Peter; Klein, Jerome O.; Kass, Edward H.


    The susceptibility of 11 T-strains, 12 strains of Mycoplasma hominis, and a single strain of M. fermentans to 15 antimicrobial agents was determined by study of inhibition of metabolic activity in a broth dilution system. All three species were inhibited by tetracycline, chloramphenicol, streptomycin, gentamicin, and kanamycin, and were relatively resistant to cephalothin, cephaloridine, polymyxin, vancomycin, and ampicillin. Three antimicrobial agents had significant differential effects on these species. Erythromycin was more active against T-strains than against M. hominis or M. fermentans. Lincomycin, clindamycin, and nitrofurantoin had greater activity against M. hominis and M. fermentans than against T-strains. The activity of the drugs tested was generally uniform over a wide range of inocula. The effect of pH and the difference between minimal inhibiting and minimal mycoplasmacidal concentrations of the drugs tested were consistent with expectations based on the effects of these drugs on bacteria. PMID:4313312

  11. Antimicrobial susceptibility of Escherichia coli from swine, horses, dogs and cats as determined in the BfT-GermVet monitoring program 2004-2006. (United States)

    Grobbel, Mirjam; Lübke-Becker, Antina; Alesík, Eva; Schwarz, Stefan; Wallmann, Jürgen; Werckenthin, Christiane; Wieler, Lothar H


    A total of 417 isolates of Escherichia coli collected from five animal species/organ system combinations from swine [urinary/genital tract (UGT) incl. mastitis metritis agalactia syndrome], horses [genital tract (GT)] and dogs/cats [respiratory tract (RT), UGT and gastrointestinal tract (GIT)] were analysed quantitatively for their susceptibility against different antimicrobial agents by determination of minimum inhibitory concentrations. Regardless of which animal species the strains originated from, resistance appeared most frequently against sulfamethoxazole (18-59%), tetracycline (14-54 %), and ampicillin (14-39%). High percentages of intermediate isolates were observed for cephalothin (39-46 %). In general, low prevalences of resistance were detected for amoxicillin/clavulanic acid (1-4%), gentamicin (1-9%), and cefazolin (0-11%). Generally speaking, the antimicrobial resistance situation among E. coli isolates from horses and small animals is relatively good.

  12. Sensibility and resistance profiles to antibiotics of pathogens isolated in a hospital unit of food and nutrition

    Directory of Open Access Journals (Sweden)

    Eliza Marques Di Primio


    Full Text Available The objective of this study was to evaluate the sensibility and resistance profiles to antibiotics of pathogens isolated in a hospital unit of food and nutrition. It was evaluated as sample spots, with repetitions, environmental samples, utensils, equipment, manipulators’ hands and usually diet that would be served to the hospitalized patients. In the evaluated samples, coagulase positive Staphylococcus (CPS and Gram negative bacillus were enumerated, and also, it was possible to isolate Klebsiella spp and Escherichia coli. The antimicrobial of less efficiency for CPS was oxacillin and penicillin-G, and for Klebsiella spp ampicillin e cephalothin. It should be emphasized that it was found strains multiresistants of CPS, Klebsiella spp and E. coli. The hospital unit of food and nutrition was evaluated as microbiological inadequate in several points, and it was verified resistance profiles to antibiotics of pathogens isolated in this unit.

  13. A rapid method for the determination of microbial susceptibility using the firefly luciferase assay for adenosine triphosphate (ATP) (United States)

    Vellend, H.; Tuttle, S. A.; Barza, M.; Weinstein, L.; Picciolo, G. L.; Chappelle, E. W.


    Luciferase assay for adenosine triphosphate (ATP) was optimized for pure bacteria in broth in order to evaluate if changes in bacterial ATP content could be used as a rapid measure of antibiotic effect on microorganisms. Broth cultures of log phase bacteria were incubated at 310 K (37 C) for 2.5 hours at antimicrobial concentrations which resulted in the best discrimination between sensitive and resistant strains. Eighty-seven strains of 11 bacterial species were studied for their susceptibility to 12 commonly used antimicrobial agents: ampicillin, Penicillin G, nafcillin, carbenicillin, cephalothin, tetracycline, erythromycin, clindamycin, gentamicin, nitrofurantoin, colistin, and chloramplenicol. The major advantage of the ATP system over existing methods of rapid microbial susceptibility testing is that the assay can be made specific for bacterial ATP.

  14. Aerokey II: a flexible key for identifying clinical Aeromonas species. (United States)

    Carnahan, A M; Behram, S; Joseph, S W


    A small subset (n = 18) of highly discriminatory tests was derived from the feature frequency of 50 tests used in the study of 167 predominantly clinical Aeromonas strains. Seven of these eighteen tests were used to construct a flexible, dichotomous key, Aerokey II, for identifying clinical aerontonads: esculin hydrolysis, gas from glucose, acid from arabinose, indole production, acid from sucrose, Voges-Proskauer reaction, and resistance to cephalothin (30 micrograms). This schema was initially evaluated in a single-blind trial of 60 well-characterized clinical Aeromonas hydrophila (n = 21), A. caviae (n = 19), and A. veronii bv. sobria (n = 20) strains from an independent laboratory. Of the 60 strains tested, 58 (97%) were accurately identified to the species level. Aerokey II was further evaluated with 18 additional American Type Culture Collection and reference strains representing the more recently proposed taxa A. veronii bv. veronii, A. schubertii, A. jandaei, and A. trota and accurately identified all of these strains.

  15. [Mobile species of the genus Aeromonas: difficulties of identification and pathogenicity]. (United States)

    Ramboarina, C; Scheftel, J M; Monteil, H


    Sixty-two Aeromonas strains (39 of clinical and 23 of environmental origin) were identified. The suicide phenomenon and autoagglutination were studied. Identification is based on esculin hydrolysis; fermentation of arabinose salicin, sucrose and mannitol; gas production from glucose, indole and beta hemolysis; Voges-Proskauer and decarboxylation reactions; and finally resistance to cephalothin (30 micrograms) and colistin (4 micrograms/ml). Thirty-four per cent of A hydrophila, 33% A caviae, 28% A veronii subspecies sobria, 3% A jandaei, 2% A veronii subspecies veronii were accurately identified. Also, several new species were identified such as A trota, A enteropelogenes, A schubertii, A ichthiosmia, according to the more recently proposed taxa. This identification scheme could enhance our knowledge concerning virulence factors, pathogenicity and environmental distribution.

  16. Spectroscopic and microbiological characterization of labdane diterpene 15,16-epoxy-4-hydroxy-labda-13(16),14-dien-3,12-dione isolated from the stems of Croton jacobinensis (United States)

    Bernardino, A. C. S. S.; Teixeira, A. M. R.; de Menezes, J. E. S. A.; Pinto, C. C. C.; Santos, H. S.; Freire, P. T. C.; Coutinho, H. D. M.; Sena Junior, D. M.; Bandeira, P. N.; Braz-Filho, R.


    In the present study, the natural product named 15,16-epoxy-4-hydroxy-labda-13(16),14-dien-3,12-dione (C20H28O4), a labdane-type diterpene was isolated from the stems of Croton jacobinensis for the first time. This new compound was characterized by infrared and Raman spectroscopy combined with Density Functional Theory calculation. Additionally, the antimicrobial and modulatory antibiotic activities of the compound towards Escherichia coli and Pseudomonas aeruginosa strains were assessed. The labdane diterpene demonstrated a modulatory effect when combined with the antibiotics assayed against both bacteria. A synergistic effect against Escherichia coli can be observed when the compound is associated with gentamicin, reducing the concentration of this antibiotic that is required to inhibit bacterial growth. Other synergistic effects can be observed with gentamicin and cephalothin antibiotics against P. aeruginosa.

  17. Properties of cephalosporinase from Proteus morganii. (United States)

    Toda, M; Inoue, M; Mitsuhashi, S


    The cephalosporin beta-lactamase (cephalosporinase) was purified from a strain of Proteus morganii which showed resistance to cephalosporins. The optimal pH was about 8.5, and the optimal temperature was 40 degrees C. The isoelectric point was 8.7 and the molecular weight was estimated to be about 41,000 from sodium dodecyl sulfate-acrylamide gel electrophoresis. The enzyme activity was inhibited by cloxacillin, ampicillin, carbenicillin, cefuroxime, cefotaxime, ceftizoxime (FK749), cefmenoxime (SCE-1365), cefoxitin, cefmetazole, YM09330 and moxalactam (6059-S), but not by clavulanic acid or CP-45899. The beta-lactamase also hydrolyzed cephaloridine, cefazolin, cephalothin, cephalexin, cefotiam, cefamandole and benzylpenicillin. These results suggest the possibility that the properties of beta-lactamases may be characterized by measuring the kinetic parameters of the enzyme toward newly-introduced beta-lactam antibiotics and beta-lactamase inhibitors.

  18. Purification and properties of a new beta-lactamase from Pseudomonas cepacia. (United States)

    Hirai, K; Iyobe, S; Inoue, M; Mitsuhashi, S


    An inducible beta-lactamase was purified from a beta-lactam antibiotic-resistant strain (GN11164) of Pseudomonas cepacia. The purified enzyme preparation gave a single protein band on polyacrylamide gel electrophoresis. The specific enzyme activity for the hydrolysis of cephalothin as a substrate was 314.5 U/mg of protein. The optimal pH was about 8.0, and the optimal temperature was 45 degrees C. The isoelectric point was 9.3, and the molecular weight was estimated to be about 22,000 to 24,000 from gel filtration on a Sephadex G-200 column and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme activity was inhibited by iodine, p-chloromercuribenzoate, clavulanic acid, CP 45899, and cloxacillin. The beta-lactamase showed a unique substrate profile by hydrolyzing most of the cephalosporins, including cefuroxime, cefotaxime (HR 756), ampicillin, and penicillin G, at a high rate.

  19. Genetic and Kinetic Characterization of the Novel AmpC β-Lactamases DHA-6 and DHA-7 (United States)

    Pérez-Llarena, Francisco José; Zamorano, Laura; Kerff, Frédéric; Beceiro, Alejandro; García, Patricia; Miró, Elisenda; Larrosa, Nieves; Gómez-Bertomeu, Frederic; Méndez, José Antonio; González-López, Juan José; Oliver, Antonio; Galleni, Moreno; Navarro, Ferran


    During a Spanish surveillance study, two natural variants of DHA β-lactamases, DHA-6 and DHA-7, were found, with the replacements Ala226Thr and Phe322Ser, respectively, with respect to DHA-1. The DHA-6 and DHA-7 enzymes were isolated from Escherichia coli and Enterobacter cloacae clinical isolates, respectively. The aim of this study was to genetically, microbiologically, and biochemically characterize the DHA-6 and DHA-7 β-lactamases. The blaDHA-6 and blaDHA-7 genes were located in the I1 and HI2 incompatibility group plasmids of 87.3 and 310.4 kb, respectively. The genetic contexts of blaDHA-6 and blaDHA-7 were similar to that already described for the blaDHA-1 gene and included the qnrB4 and aadA genes. The MICs for cephalothin, aztreonam, cefotaxime, and ceftazidime were 8- to 32-fold lower for DHA-6 than for DHA-1 or DHA-7 expressed in the same isogenic E. coli TG1 strain. Interestingly, the MIC for cefoxitin was higher in the DHA-6-expressing transformant than in DHA-1 or DHA-7. Biochemical studies with pure β-lactamases revealed slightly lower catalytic efficiencies of DHA-6 against cephalothin, ceftazidime, and cefotaxime than those of DHA-1 and DHA-7. To understand this behavior, stability experiments were carried out and showed that the DHA-6 protein displayed significantly higher stability than the DHA-1 and DHA-7 enzymes. The proximity of Thr226 to the N terminus in the tertiary protein structure in DHA-6 may promote this stabilization and, consequently, may induce a slight reduction in the dynamic of this enzyme that primarily affects the hydrolysis of some of the bulkiest antibiotics. PMID:25136023

  20. Prevalence, antimicrobial susceptibility and virulotyping of Listeria species and Listeria monocytogenes isolated from open-air fish markets. (United States)

    Jamali, Hossein; Paydar, Mohammadjavad; Ismail, Salmah; Looi, Chung Yeng; Wong, Won Fen; Radmehr, Behrad; Abedini, Atefeh


    The aim of this study was to investigate the prevalence and characterization of Listeria species and Listeria monocytogenes isolated from raw fish and open-air fish market environments. Eight hundred and sixty two samples including raw fish and fish market environments (samples from workers' hands, workers' knives, containers and work surface) were collected from the open-air fish markets in the Northern region of Iran. Listeria spp. was isolated from 104/488 (21.3%) raw fish and 29/374 (7.8%) of samples from open-air fish market environment. The isolates of Listeria spp. included L. innocua (35.3%), L. monocytogenes (32.3%), L. seeligeri (18%), and L. ivanovii (14.3%). Of the 43 L. monocytogenes isolates, 31 (72.1%), 10 (23.3%) and 2 (4.7%) belonged to serovars 1/2a, 4b, and 1/2b, respectively. The inlA, inlB, inlC, inlJ, actA, hlyA, iap, plcA, and prfA virulence-associated genes were detected in almost all of the L. monocytogenes isolates. The Listeria spp. isolates showed high resistance against tetracycline (23.3%), penicillin G, and cephalothin (each 16.5%). Besides, we observed significant resistance level to tetracycline (27.9%), ampicillin (20.9%), cephalothin, penicillin G, and streptomycin (each 16.3%) in the L. monocytogenes isolates. All of the isolates were susceptible to cefotaxime, gentamicin, kanamycin, and pefloxacin. We found that tetM (25.6%), tetA (23.3%), ampC (14%), and penA (11.6%) were the most prevalent antibiotic resistance genes in the L. monocytogenes isolates. Recovery of potentially pathogenic L. monocytogenes from raw fish and environment of open-air fish market samples in this study is a convincing evidence for the zoonotic potential of listeriosis.

  1. Antimicrobial Resistance Percentages of Salmonella and Shigella in Seafood Imported to Jordan: Higher Percentages and More Diverse Profiles in Shigella. (United States)

    Obaidat, Mohammad M; Bani Salman, Alaa E


    This study determined the prevalence and antimicrobial resistance of human-specific ( Shigella spp.) and zoonotic ( Salmonella enterica ) foodborne pathogens in internationally traded seafood. Sixty-four Salmonella and 61 Shigella isolates were obtained from 330 imported fresh fish samples from Egypt, Yemen, and India. The pathogens were isolated on selective media, confirmed by PCR, and tested for antimicrobial resistance. Approximately 79 and 98% of the Salmonella and Shigella isolates, respectively, exhibited resistance to at least one antimicrobial, and 8 and 49% exhibited multidrug resistance (resistance to three or more antimicrobial classes). Generally, Salmonella exhibited high resistance to amoxicillin-clavulanic acid, cephalothin, streptomycin, and ampicillin; very low resistance to kanamycin, tetracycline, gentamicin, chloramphenicol, nalidixic acid, sulfamethoxazole-trimethoprim, and ciprofloxacin; and no resistance to ceftriaxone. Meanwhile, Shigella spp. exhibited high resistance to tetracycline, amoxicillin-clavulanic acid, cephalothin, streptomycin, and ampicillin; low resistance to kanamycin, nalidixic acid, sulfamethoxazole-trimethoprim, and ceftriaxone; and very low resistance to gentamicin and ciprofloxacin. Salmonella isolates exhibited 14 resistance profiles, Shigella isolates 42. This study is novel in showing that a human-specific pathogen has higher antimicrobial resistance percentages and more diverse profiles than a zoonotic pathogen. Thus, the impact of antimicrobial use in humans is as significant as, if not more significant than, it is in animals in spreading antibiotic resistance through food. This study also demonstrates that locally derived antimicrobial resistance can spread and pose a public health risk worldwide through seafood trade and that high resistance would make a possible outbreak difficult to control. So, capacity building and monitoring harvest water areas are encouraged in fish producing countries.

  2. Antimicrobial resistance profiles of Shiga toxin-producing Escherichia coli O157 and Non-O157 recovered from domestic farm animals in rural communities in Northwestern Mexico

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    Bianca A. Amézquita-López


    Full Text Available Abstract Background Antimicrobial resistance in Shiga toxin-producing Escherichia coli (STEC O157 and non-O157 is a matter of increasing concern. The aim of the present study was to investigate the antimicrobial resistance profiles of STEC O157 and non-O157 recovered from feces of domestic farm animals in the agricultural Culiacan Valley in Northwestern Mexico. Findings All of the examined STEC strains showed susceptibility to five antimicrobials, ceftazidime, ceftriaxone, ciprofloxacin, nalidixic acid, and trimethoprim-sulfamethoxazole. However, resistance to the four antimicrobials, ampicillin, cephalothin, chloramphenicol, and kanamycin was commonly observed. Interestingly, non-susceptibility to cephalothin was predominant among the examined STEC strains, corresponding to 85 % (22/26 of the O157:H7 from cattle, sheep and chicken and 73 % (24/33 of the non-O157 strains from cattle and sheep. Statistical analyses revealed that resistance to ampicillin was significantly correlated to 38 % (10/26 of STEC O157:H7 strains from multiple animal sources. Another significant correlation was found between serotype, source, and antimicrobial resistance; all of the O20:H4 strains, recovered from sheep, were highly resistant to tetracycline. Multidrug resistance profiles were identified in 42 % (22/53 of the non-susceptible STEC strains with clinically-relevant serotypes O8:H9, O75:H8, O146:H21, and O157:H7. Conclusions STEC O157 and non-O157 strains, recovered from domestic farm animals in the Culiacan Valley, exhibited resistance to classes of antimicrobials commonly used in Mexico, such as aminoglycosides, tetracyclines, cephalosporins and penicillin but were susceptible to fluoroquinolones, quinolones, and sulfonamides. These findings provide fundamental information that would aid in the surveillance of antimicrobial resistance in an important agricultural region in Northwestern Mexico.

  3. Isolation Pseudomonas and Acinetobacter from Blood Specimens in Patients Hospitalized in Emam Khomeini Hospital (Kermanshah

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    S. Somayeh Jasemi


    Full Text Available Background: Bloodstream infections (BSIs are an important cause of morbidity and mortality. The rates of antibiotic resistance among pathogens causing health care-associated infections are increasing, principally among Gram-negative organisms such as Pseudomonas, and Acinetobacter. The goal of this study was isolation Pseudomonas spp. and Acinetobacter spp. from blood specimens in patients hospitalized in Emam Khomeini hospital (Kermanshah and subsequently determination susceptibility patterns of isolates. Materials and Methods: In this cross-sectional study 2382 blood samples collected from 2285 hospitalized patients. Blood specimens were inoculated in blood culture tubes media, and subsequently subculture performed on common microbiological media. The isolated Pseudomonas, and Acinetobacter were identified and confirmed by morphological and biochemical laboratory tests. Antimicrobial sensitivity test was performed by using the standard disc diffusion method according to CLSI (2012 recommendations. Results: During present study 2382 blood samples were collected. 133 (5.6% specimens were positive in bacterial culture. Acinetobacter, and Pseudomonas were isolated from 15 (11.2% and 15 (11.2% of positive blood cultures, respectively. The isolated Acinetobacter were most frequent resistant to cefixime (86.7%, ceftazidime (80.1%, cephalothin (73.4%, and co-trimoxazole (73.4%. The Pseudomonas isolates showed a high level of resistance to co-trimoxazole (86.7%, cefixime (86.7%, ceftriaxone (73.4%, cephalothin (73.4%, and ceftazidime (60%. Conclusion: In this research, drug-resistant Pseudomonas and Acinetobacter were identified in patient’s blood cultures. In the face of increasing antibiotic resistance, surveillance programs have become important in determination the species distribution and resistance patterns of pathogens causing bloodstream infection, and thus are providing the basis for appropriate empirical therapy of patients.

  4. Novel class A beta-lactamase Sed-1 from Citrobacter sedlakii: genetic diversity of beta-lactamases within the Citrobacter genus. (United States)

    Petrella, S; Clermont, D; Casin, I; Jarlier, V; Sougakoff, W


    Citrobacter sedlakii 2596, a clinical strain resistant to aminopenicillins, carboxypenicillins, and early cephalosporins such as cephalothin, but remaining susceptible to acylureidopenicillins, carbapenems, and later cephalosporins such as cefotaxime, was isolated from the bile of a patient treated with beta-lactam and quinolone antibiotics. The isolate produced an inducible class A beta-lactamase of pI 8.6, named Sed-1, which was purified. Characterized by a molecular mass of 30 kDa, Sed-1 preferentially hydrolyzed benzylpenicillin, cephalothin, and cloxacillin. The corresponding gene, bla(Sed-1), was cloned and sequenced. Its deduced amino acid sequence shared more than 60% identity with the chromosome-encoded beta-lactamases from Citrobacter koseri (formerly C. diversus) (84%), Klebsiella oxytoca (74%), Serratia fonticola (67%), and Proteus vulgaris (63%) and 71% identity with the plasmid-mediated enzyme MEN-1. A gene coding for a LysR transcriptional regulator was found upstream from bla(Sed-1). This regulator, named SedR, displayed 90% identity with the AmpR sequence of the chromosomal beta-lactamase from C. koseri and 63 and 50% identity with the AmpR sequences of P. vulgaris and Enterobacter cloacae, respectively. By using DNA-DNA hybridization, a bla(Sed-1)-like gene was identified in two reference strains, C. sedlakii (CIP-105037) and Citrobacter rodentium (CIP-104675), but not in the 18 strains of C. koseri studied. Two DNA fragments were amplified and sequenced from the reference strains of C. sedlakii CIP-105037 and C. rodentium CIP-104675 using two primers specific for bla(Sed-1). They shared 98 and 80% identity with bla(Sed-1), respectively, confirming the diversity of the chromosomally encoded class A beta-lactamases found in Citrobacter.

  5. Validation study of the BetaStar plus lateral flow assay for detection of beta-lactam antibiotics in milk. (United States)

    Abouzied, Mohamed; Driksna, Dana; Walsh, Coilin; Sarzynski, Michael; Walsh, Aaron; Ankrapp, David; Klein, Frank; Rice, Jennifer; Mozola, Mark


    A validation study designed to meet the requirements of the AOAC Research Institute and the U.S. Food and Drug Administration, Center for Veterinary Medicine (FDA/CVM) was conducted for a receptor and antibody-based, immunochromatographic method (BetaStar Plus) for detection of beta-lactam antibiotic residues in raw, commingled bovine milk. The assay was found to detect amoxicillin, ampicillin, ceftiofur, cephapirin, cloxacillin, and penicillin G at levels below the FDA tolerance/safe levels, but above the maximum sensitivity thresholds established by the National Conference on Interstate Milk Shipments (NCIMS). Results of the part I (internal) and part II (independent laboratory) dose-response studies employing spiked samples were in close agreement. The test was able to detect all six drugs at the approximate 90/95% sensitivity levels when presented as incurred residues in milk collected from cows that had been treated with the specific drug. Selectivity of the assay was 100%, as no false-positive results were obtained in testing of 1031 control milk samples. Results of ruggedness experiments established the operating parameter tolerances for the BetaStar Plus assay. Results of cross-reactivity testing established that the assay detects certain other beta-lactam drugs (dicloxacillin and ticarcillin), but it does not cross-react with any of 30 drugs belonging to other classes. Abnormally high bacterial or somatic cell counts in raw milk produced no interference with the ability of the test to detect beta-lactams at tolerance/safe levels.

  6. High-throughput method for the determination of residues of β-lactam antibiotics in bovine milk by LC-MS/MS. (United States)

    Jank, Louise; Martins, Magda Targa; Arsand, Juliana Bazzan; Hoff, Rodrigo Barcellos; Barreto, Fabiano; Pizzolato, Tânia Mara


    This study describes the development and validation procedures for scope extension of a method for the determination of β-lactam antibiotic residues (ampicillin, amoxicillin, penicillin G, penicillin V, oxacillin, cloxacillin, dicloxacillin, nafcillin, ceftiofur, cefquinome, cefoperazone, cephapirine, cefalexin and cephalonium) in bovine milk. Sample preparation was performed by liquid-liquid extraction (LLE) followed by two clean-up steps, including low temperature purification (LTP) and a solid phase dispersion clean-up. Extracts were analysed using a liquid chromatography-electrospray-tandem mass spectrometry system (LC-ESI-MS/MS). Chromatographic separation was performed in a C18 column, using methanol and water (both with 0.1% of formic acid) as mobile phase. Method validation was performed according to the criteria of Commission Decision 2002/657/EC. Main validation parameters such as linearity, limit of detection, decision limit (CCα), detection capability (CCβ), accuracy, and repeatability were determined and were shown to be adequate. The method was applied to real samples (more than 250) and two milk samples had levels above maximum residues limits (MRLs) for cloxacillin - CLX and cefapirin - CFAP.

  7. Listeria monocytogenes strains isolated from dry milk samples in Mexico: occurrence and antibiotic sensitivity. (United States)

    Rodas-Suárez, O R; Quiñones-Ramírez, E I; Fernández, F J; Vázquez-Salinas, C


    Dry milk is a particular concern in Mexico, as approximately 150,000 metric tons of dry milk are imported every year at a cost of around $250 million. Dry milk is used to make many products, most of which are dairy products widely distributed among the population covered by welfare programs. The purpose of the study described in this article was to determine the presence of Listeria spp. in imported dry milk samples in Mexico, and to determine the sensitivity of the Listeria monocytogenes isolates to different antimicrobial agents. Listeria isolates (7.8% of 550 bacterial isolates) were identified as L. monocytogenes (53.49%), L. innocua (30.23%), L. seeligeri (13.95%), and L. ivanovii (2.33%). L. monocytogenes strains isolated showed multiresistance to ampicillin, erythromycin, tetracycline, dicloxacillin, and trimethoprim-sulfamethoxazole (9%-14%). The results provide additional evidence of the emergence of multiresistant Listeria strains both in nature and in widely consumed dairy products, representing a potential threat to human health.

  8. CINÉTICA, PRUEBA DE CRECIMIENTO Y EFECTO DE INHIBICIÓN DE Lactococcus lactis SOBRE Yersinia pseudotuberculosis

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    Full Text Available Lactic acid bacteria have demonstrated a high ability to inhibit pathogenic microorganisms, which improve knowledge of such microorganisms is important, for this, the kinetics was determined, growth and the inhibition effect of Lactococcus lactis on Yersinia pseudotuberculosis. The research was conducted at the University of Nariño, by susceptibility testing in all strains; in vitro inhibition of Lc. lactis and supernatant on bacterial pathogen; gastrointestinal lactic strain testing (gas production and catalase, bile, bile salts and 2 temperatures, growth kinetics and HPLC determination of peptides in the supernatant. dicloxacillin resistance was found in both strains. Lactic strain and the supernatant inhibited Y. pseudotuberculosis. growths and 3,9x1010 3x1011 CFU/150 uL to 3 to 5% bile salts, 3x1011 5x1012 and CFU/150 uL 1 and 2% bovine 3x1013 and 3x1012 bile and CFU/150 uL was found 38 and 45°C. The logarithmic phase of Lc. lactis was found at 3 hours with values 6,4x1012 CFU/150 uL. The VAL-TIR-VAL peptide was found in the supernatant. It is concluded that Lc lactis shows probiotic characteristics in in vitro conditions.

  9. Electronic structure and physicochemical properties of selected penicillins (United States)

    Soriano-Correa, Catalina; Ruiz, Juan F. Sánchez; Raya, A.; Esquivel, Rodolfo O.

    Traditionally, penicillins have been used as antibacterial agents due to their characteristics and widespread applications with few collateral effects, which have motivated several theoretical and experimental studies. Despite the latter, their mechanism of biological action has not been completely elucidated. We present a theoretical study at the Hartree-Fock and density functional theory (DFT) levels of theory of a selected group of penicillins such as the penicillin-G, amoxicillin, ampicillin, dicloxacillin, and carbenicillin molecules, to systematically determine the electron structure of full ?-lactam antibiotics. Our results allow us to analyze the electronic properties of the pharmacophore group, the aminoacyl side-chain, and the influence of the substituents (R and X) attached to the aminoacyl side-chain at 6? (in contrast with previous studies focused at the 3? substituents), and to corroborate the results of previous studies performed at the semiempirical level, solely on the ?-lactam ring of penicillins. Besides, several density descriptors are determined with the purpose of analyzing their link to the antibacterial activity of these penicillin compounds. Our results for the atomic charges (fitted to the electrostatic potential), the bond orders, and several global reactivity descriptors, such as the dipole moments, ionization potential, hardness, and the electrophilicity index, led us to characterize: the active sites, the effect of the electron-attracting substituent properties and their physicochemical features, which altogether, might be important to understand the biological activity of these type of molecules.

  10. Prevalence of bovine subclinical mastitis, its etiology and diagnosis of antibiotic resistance of dairy farms in four municipalities of a tropical region of Mexico. (United States)

    Olivares-Pérez, Jaime; Kholif, Ahmed Eid; Rojas-Hernández, Saul; Elghandour, Mona Mohamed Mohamed Yasseen; Salem, Abdelfattah Zeidan Mohamed; Bastida, Adrian Zaragoza; Velázquez-Reynoso, David; Cipriano-Salazar, Moisés; Camacho-Díaz, Luis Miguel; Alonso-Fresán, María Uxúa; DiLorenzo, Nicolas


    A region-wide survey was conducted in the tropical area of Tierra Caliente, State of Guerrero, Mexico to estimate the prevalence of subclinical bovine mastitis (SCM), distribution of mastitis pathogens, and in vitro antimicrobial susceptibility of different mastitis pathogens in dairy farms. In total, 1036 quarter milk samples were obtained from 259 cows at 87 different dairy farms. Collected quarter milk samples were submitted for California Mastitis Test (CMT), bacteriological examination, and testing for antimicrobial susceptibility. Overall prevalence of SCM in the studied area was 20.5 %. Prevalence in the different regions was as follows: 28 % in Arcelia municipality, 21 % in Tlalchapa municipality, 19.4 % in Pungarabato municipality, and 14.3 % in Finch Cutzamala municipality. Of all positive isolates, 97.5 % were Gram-negative bacteria. Moreover, of all positive isolates, 37.5 % were Proteus vulgaris, 25 % Salmonella spp., 12.5 % Enterobacter aerogenes, and 10 % Escherichia coli. Klebsiella pneumonia and E. coli were sensitive for netilmicin antimicrobial. However, E. coli was sensitive for pefloxacin and gentamicin with a sensitivity for pefloxacin for E. aerogenes, while Staphylococci were sensitive for gentamicin and dicloxacillin. It could be concluded that practices such as the implementation of mastitis control programs, improved milking hygiene together with an intramammary treatment with netilmicin, pefloxacin, and gentamicin antimicrobials should be considered for mastitis prevention in the study area of Tierra Caliente, in the tropical area of Guerrero, Mexico.

  11. Supravalvular aortic stenosis associated to infectious endocarditis and cerebral vascular disease in a patient with Williams-Beuren Syndrome. (United States)

    De Rubens Figueroa, Jesús; Marhx, Alfonso; López Terrazas, Javier; Palacios Macedo, Alexis


    The Williams-Beuren syndrome is a rare genetic disease characterized by: (a) typical facial features; (b) psychomotor retardation with a specific neurocognitive profile; (c) cardiovascular condition and (d) likely transient hypocalcemia in infancy. The objective of this study was to describe the clinic evolution and diagnosis of patient with this syndrome that was associated with endocarditis caused by Streptococcus parasanguis in the ascending aorta and an aneurism located in the fronto-temporal area, which produced a parenchymal hematoma in the left lobe, and subarachnoid hemorrhage. He was treated with ceftriaxone and dicloxacillin. Then we proceeded to correct the aneurysm and perform vegetation resection in aortic arteries with supravalvular aortic stenosis correction. The evolution after one year has been favorable and is currently without neurologic sequelae. A 5-year-old male patient presented a diagnosis of supravalvular aortic stenosis. After cardiac catheterization was performed, he presented a fever and right side paresis. The echocardiogram showed multiple vegetations in the ascendant aortic arch and the supraortic arteries. The blood cultures reported S. parasanguis. The magnetic resonance showed a subarachnoid hemorrhage with an aneurysm and a hematoma. Copyright © 2014 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  12. Fast HPLC-MS/MS Method for Determining Penicillin Antibiotics in Infant Formulas Using Molecularly Imprinted Solid-Phase Extraction

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    Mónica Díaz-Bao


    Full Text Available The dairy cattle may suffer from different infections relatively often, but the inflammation of the mammary gland is very important to the farmer. These infections are frequently treated with penicillin antimicrobial drugs. However, their use may result in the presence of residues in animal products, such as milk powder and/or infant formulas, and it represents a potential risk for consumers. To monitor this, the EU has defined safe maximum residue limits (MRLs through Commission Regulation (EU number 37/2010. Although LC-MS is a trustful option for confirmation and quantification of antibiotics, the analysis of real samples with complex matrices frequently implies previous clean-up steps. In this work, precipitation polymerization has been used and different molecularly imprinted polymer (MIP sorbents were tested and optimized for the fast and simultaneous solid-phase extraction (MISPE of eight common penicillins (ampicillin, amoxicillin, oxacillin, penicillin G, penicillin V, cloxacillin, dicloxacillin, and nafcillin. The extracts were analyzed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS and the applicability of these polymers as sorbents for the extraction of penicillins at MRL levels in milk powder (infant formulas was proved. The limits of detection and quantification were below the legal tolerances, except for LOQ for oxacillin and cloxacillin.

  13. Analysis of the interactions between human serum albumin/amphiphilic penicillin in different aqueous media: an isothermal titration calorimetry and dynamic light scattering study

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    Barbosa, Silvia [Grupo de Sistemas Complejos, Laboratorio de Fisica de Coloides y Polimeros, Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela (Spain); Taboada, Pablo [Grupo de Sistemas Complejos, Laboratorio de Fisica de Coloides y Polimeros, Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela (Spain)]. E-mail:; Mosquera, Victor [Grupo de Sistemas Complejos, Laboratorio de Fisica de Coloides y Polimeros, Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela (Spain)


    The complexation process of the amphiphilic penicillins sodium cloxacillin and sodium dicloxacillin with the protein human serum albumin (HSA) in aqueous buffered solutions of pH 4.5 and 7.4 at 25 {sup o}C was investigated through isothermal titration calorimetry (ITC) and dynamic light scattering. ITC experiments were carried out in the very dilute regime and showed that although hydrophobic interactions are the leading forces for complexation, electrostatic interactions also play an important role. The possibility of the formation of hydrogen bonds is also deduced from experimental data. The thermodynamic quantities of the binding mechanism, i.e, the enthalpy, {delta}HITCi, entropy, {delta}SITCi, Gibbs energy, {delta}GITCi, binding constant, KITCi and the number of binding sites, n{sub i}, were obtained. The binding was saturable and is characterised by Langmuir adsorption isotherms. From ITC data and following a theoretical model, the number of bound and free penicillin molecules was calculated. From Scatchard plots, KITCi and n{sub i} were obtained and compared with those from ITC data. The interaction potential between the HSA-penicillin complexes and their stability were determined at pH 7.4 from the dependence of the diffusion coefficients on protein concentration by application of the DLVO colloidal stability theory. The results indicate decreasing stability of the colloidal dispersion of the drug-protein complexes with increase in the concentration of added drug.

  14. Analysis of the interactions between human serum albumin/amphiphilic penicillin in different aqueous media: an isothermal titration calorimetry and dynamic light scattering study (United States)

    Barbosa, Silvia; Taboada, Pablo; Mosquera, Victor


    The complexation process of the amphiphilic penicillins sodium cloxacillin and sodium dicloxacillin with the protein human serum albumin (HSA) in aqueous buffered solutions of pH 4.5 and 7.4 at 25 °C was investigated through isothermal titration calorimetry (ITC) and dynamic light scattering. ITC experiments were carried out in the very dilute regime and showed that although hydrophobic interactions are the leading forces for complexation, electrostatic interactions also play an important role. The possibility of the formation of hydrogen bonds is also deduced from experimental data. The thermodynamic quantities of the binding mechanism, i.e, the enthalpy, ΔHITCi, entropy, ΔSITCi, Gibbs energy, ΔGITCi, binding constant, KITCi and the number of binding sites, ni, were obtained. The binding was saturable and is characterised by Langmuir adsorption isotherms. From ITC data and following a theoretical model, the number of bound and free penicillin molecules was calculated. From Scatchard plots, KITCi and ni were obtained and compared with those from ITC data. The interaction potential between the HSA-penicillin complexes and their stability were determined at pH 7.4 from the dependence of the diffusion coefficients on protein concentration by application of the DLVO colloidal stability theory. The results indicate decreasing stability of the colloidal dispersion of the drug-protein complexes with increase in the concentration of added drug.

  15. Management of mastitis in breastfeeding women. (United States)

    Spencer, Jeanne P


    Mastitis occurs in approximately 10 percent of U.S. mothers who are breastfeeding, and it can lead to the cessation of breastfeeding. The risk of mastitis can be reduced by frequent, complete emptying of the breast and by optimizing breastfeeding technique. Sore nipples can precipitate mastitis. The differential diagnosis of sore nipples includes mechanical irritation from a poor latch or infant mouth anomalies, such as cleft palate or bacterial or yeast infection. The diagnosis of mastitis is usually clinical, with patients presenting with focal tenderness in one breast accompanied by fever and malaise. Treatment includes changing breastfeeding technique, often with the assistance of a lactation consultant. When antibiotics are needed, those effective against Staphylococcus aureus (e.g., dicloxacillin, cephalexin) are preferred. As methicillin-resistant S. aureus becomes more common, it is likely to be a more common cause of mastitis, and antibiotics that are effective against this organism may become preferred. Continued breastfeeding should be encouraged in the presence of mastitis and generally does not pose a risk to the infant. Breast abscess is the most common complication of mastitis. It can be prevented by early treatment of mastitis and continued breastfeeding. Once an abscess occurs, surgical drainage or needle aspiration is needed. Breastfeeding can usually continue in the presence of a treated abscess.

  16. Adsorption and release of antibiotics from morselized cancellous bone. In vitro studies of 8 antibiotics. (United States)

    Witsø, E; Persen, L; Løseth, K; Bergh, K


    We studied the basic release patterns of antibiotics from cancellous bone in vitro. Antibiotic-impregnated bone was compressed into a wire-mesh cylinder and the release of antibiotic was assessed by two different in vitro methods: agar diffusion and broth elution. The zones of inhibition were measured on seeded agar and the amounts of antibiotics released in elution tubes were assessed by a bioassay. The study continued for 21 days with daily transfer of the cylinders. The results indicated that benzylpenicillin, dicloxacillin, cephalotin, netilmicin, clindamycin, vancomycin, ciprofloxacin and rifampicin were adsorbed to cancellous bone in vitro. Compared to broth elution, agar diffusion showed a prolonged period of release, owing to the small amounts of antibiotic leaking out of the cylinder into the agar. The betalactams had antibacterial activity in broth for a shorter time than the other antibiotics. The release patterns of the betalactams were similar, in spite of their differences in thermal stability. Only rifampicin showed a concentration higher than MIC for longer than 21 days.

  17. Potential use of Bacillus thuringiensis bacteriocins to control antibiotic-resistant bacteria associated with mastitis in dairy goats. (United States)

    Gutiérrez-Chávez, A J; Martínez-Ortega, E A; Valencia-Posadas, M; León-Galván, M F; de la Fuente-Salcido, N M; Bideshi, D K; Barboza-Corona, J E


    Mastitis caused by microbial infections in dairy goats reduces milk yield, modifies milk composition, and potentially contributes to morbidity in herds and consumers of dairy products. Microorganisms associated with mastitis in dairy goats are commonly controlled with antibiotics, but it is known that continued use of these chemical agents promotes antibiotic resistance among bacterial populations. Recently, it has been shown that bacteriocins of Bacillus thuringiensis inhibit growth of food-borne pathogens and also bacteria associated with bovine mastitis. However, there is no report on their ability to inhibit microorganisms linked to mastitis in dairy goats. In this study, using 16S rDNA and ITS regions of rDNA, we identified nine bacterial isolates and an encapsulated yeast associated with mastitis in dairy goats. Enterococcus durans, Brevibacillus sp., and Staphylococcus epidermidis 2 were resistant to, respectively, 75, ~67, ~42, and ~42 % of the antibiotics screened. In addition, 60 % of the bacterial isolates were resistant to penicillin, ampicillin, vancomycin, and dicloxacillin. Importantly, 60 % of the isolates were inhibited by the bacteriocins, but S. epidermidis 1, Enterobacter sp., Escherichia vulneris, and Cryptococcus neoformans were not susceptible to these antimicrobial peptides. Using Brevibacillus sp. and Staphylococcus chromogenes as indicator bacteria, we show that peptides of ~10 kDa that correspond to the molecular mass of bacteriocins used in this study are responsible for the inhibitory activity. Our results demonstrate that multiple antibiotic-resistant bacteria associated with subclinical mastitis in dairy goats from Guanajuato, Mexico, are susceptible to bacteriocins produced by B. thuringiensis.

  18. Multiresidue analytical method for the determination of eight penicillin antibiotics in muscle tissue by ion-pair reversed-phase HPLC after precolumn derivatization. (United States)

    Verdon, E; Couëdor, P


    A high-performance liquid chromatographic multiresidue method was developed for the determination of 8 penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, ampicillin, amoxicillin, nafcillin, oxacillin, cloxacillin, and dicloxacillin) at trace levels in muscle tissue. This method involves extraction of the penicillins with phosphate buffer pH 9 followed by cleanup and concentration on a C18 solid-phase extraction column and reaction with benzoic anhydride at 50 degrees C for 5 min and with 1,2,4-triazole and mercury(II) chloride solution pH 9 at 65 degrees C for 10 min. The derivatized compounds are eluted on a C8 column with a mobile phase containing acetonitrile and phosphate buffer (pH 6; 0.1 mol/L) loaded with sodium thiosulfate and ion-pairing tetrabutylammonium hydrogenosulphate. The method detection limit is approximately 3-11 micrograms/kg and the limit of determination was evaluated down to 25 micrograms/kg in line with the criteria of the EU decision No. 93/256/EEC.

  19. Comparative assessment of antibiotic susceptibility of coagulase-negative staphylococci in biofilm versus planktonic culture as assessed by bacterial enumeration or rapid XTT colorimetry. (United States)

    Cerca, Nuno; Martins, Silvia; Cerca, Filipe; Jefferson, Kimberly K; Pier, Gerald B; Oliveira, Rosário; Azeredo, Joana


    To quantitatively compare the antibiotic susceptibility of biofilms formed by the coagulase-negative staphylococci (CoNS) Staphylococcus epidermidis and Staphylococcus haemolyticus with the susceptibility of planktonic cultures. Several CoNS strains were grown planktonically or as biofilms to determine the effect of the mode of growth on the level of susceptibility to antibiotics with different mechanisms of action. The utility of a new, rapid colorimetric method that is based on the reduction of a tetrazolium salt (XTT) to measure cell viability was tested by comparison with standard bacterial enumeration techniques. A 6 h kinetic study was performed using dicloxacillin, cefazolin, vancomycin, tetracycline and rifampicin at the peak serum concentration of each antibiotic. In planktonic cells, inhibitors of cell wall synthesis were highly effective over a 3 h period. Biofilms were much less susceptible than planktonic cultures to all antibiotics tested, particularly inhibitors of cell wall synthesis. The susceptibility to inhibitors of protein and RNA synthesis was affected by the biofilm phenotype to a lesser degree. Standard bacterial enumeration techniques and the XTT method produced equivalent results both in biofilms and planktonic assays. This study provides a more accurate comparison between the antibiotic susceptibilities of planktonic versus biofilm populations, because the cell densities in the two populations were similar and because we measured the concentration required to inhibit bacterial metabolism rather than to eradicate the entire bacterial population. While the biofilm phenotype is highly resistant to antibiotics that target cell wall synthesis, it is fairly susceptible to antibiotics that target RNA and protein synthesis.

  20. [Analysis of drug resistance ofAcinetobacter baumanniiin wound of children with traffic injury and its relationship with antibiotic use]. (United States)

    Liu, S; Wang, C; Fu, Y X


    Objective: To know the drug resistance of Acinetobacter baumannii (AB) in wound of children with traffic injury and its relationship with antibiotic use. Methods: Wound exudate of 226 children with traffic injury admitted to our unit from January 2010 to December 2015 were collected. API bacteria identification panels and fully automatic microbiological identification system were used to identify pathogens. Kirby-Bauer paper disk diffusion method was used to detect the drug resistance of pathogens to 18 antibiotics including amoxycillin/clavulanic acid, piperacillin/tazobactam, and imipenem. The detection situation of pathogen of children's wounds and drug resistance of detected AB to 18 antibiotics in each year were collected. Forty-six AB positive children (2 children excluded) were divided into imipenem-resistant group (IR, n =19) and non imipenem-resistant group (NIR, n =25) according to whether AB was 100% resistant to imipenem. Drug resistance of AB in wounds of children to 18 antibiotics in two groups was compared. The antibiotic use of AB positive children was collected, and the antibiotic use intensity of children in two groups was compared. Data were processed with Fisher's exact test, independent sample t test, and corrected t test. Results: (1) The detection rates of pathogen in wounds of children in 2010-2015 were 95.6% (43/45), 89.8% (53/59), 81.3% (148/182), 81.1% (107/132), 81.6% (120/147), and 77.5% (62/80), respectively, showing a trend of decreasing year by year. A total of 665 strains and 75 pathogens were detected, and the top 5 pathogens with detection rate from high to low were AB, Pseudomonas aeruginosa, Enterobacter cloacae, Staphylococcus epidermidis, and Escherichia coli, respectively. (2) Drug resistance rates of AB to amoxycillin/clavulanic acid, cefazolin, aztreonam, and piperacillin were all 100%, while AB was 100% sensitive to polymyxin, and the total drug resistance rates of AB to the other 13 antibiotics were all above 50%. The

  1. Emergence of Multi-drug Resistant ESBL Producing Strains among Enterobacteriaceae Members Isolated from Patients Blood Samples in South of Iran.

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    Jalal Mardaneh


    Full Text Available Background: Extended-spectrum beta-lactamases (ESBLs have emerged as important mechanism of resistance among enterobacteriaceae family. These ESBL positive strains are major problem in hospitalized patients. The goal of this study was the survey emergence of multi-drug resistant ESBL producing strains among enterobacteriaceae members isolated from patients blood samples using BACTEC 9240 automatic system in south of Iran. Materials & Methods: In this cross-sectional study, 4825 blood samples were collected from hospitalized patients, and positive samples were detected by BACTEC automatic system. Positive blood cultures removed from BACTEC and subculture was performed on microbiological media including blood agar, chocolate agar and MacConkey agar. The isolates were identified based on biochemical tests embedded in the API-20E system. Susceptibility testing (disc diffusion was performed according clinical and laboratory standards institute (CLSI, 2013 guidelines. Phenotypic detection of extended spectrum beta-lactamase producing isolates was performed by double disk synergy test (DDST. Results: Total 1145 (24% blood cultures were positive that among them 248 (21.5% belonged to the enterobacteriaceae family. The most common isolates in this family were Escherichia coli (46.5%, Klebsiella spp. (28%, Enterobacter spp. (13.5%. Among enterobacteriaceae family, ampicillin was most effective drug against Salmonella isolates. Escherichia coli was the most common ESBL-producing isolate (58% of isolates were ESBL positive. Respectively, polymyxin B, colistin, imipenem were the most effective drugs against ESBL-positive Klebsiella strains. The ESBL-positive Enterobacter strains showed lowest resistance to imipenem (7.7%. All ESBL positive Serratia isolates were sensitive to chloramphenicol, co-trimoxazole and imipenem. Conclusion: Results showed unfortunately betalactam antibiotics are not effective against more than 40% of bacteremia caused by Escherichia

  2. Comparative activity of carbapenem testing (the COMPACT study) in Turkey (United States)


    Background Recent evidence indicates that Gram-negative bacterial pathogens, the most common of which are Pseudomonas spp., Enterobacteriaceae, and Acinetobacter baumannii, are frequent causes of hospital-acquired infections. This study aims to evaluate the in vitro activity of doripenem and comparator carbapenem antibiotics against Gram-negative clinical isolates collected from COMParative Activity of Carbapenem Testing (COMPACT) study centres in Turkey. Methods Ten centres in Turkey were invited to submit Pseudomonas aeruginosa, Enterobacteriaceae, and other Gram-negative isolates from intensive care unit (ICU)/non-ICU patients with complicated intra-abdominal infections, bloodstream infections, or nosocomial pneumonia, including ventilator-associated pneumonia, between May and October 2008. Susceptibility was determined by each centre using E-test. A central laboratory performed species confirmation as well as limited susceptibility and quality-control testing. Results Five hundred and ninety six isolates were collected. MIC90 values for doripenem, meropenem, and imipenem, respectively, were 32, ≥ 64, and ≥ 64 mg/L against Pseudomonas spp.; 0.12, 0.12, and 0.5 mg/L against Enterobacteriaceae; and ≥ 64 mg/L for each against other Gram-negative isolates. In determining the susceptibility of hospital isolates of selected Gram-negative pathogens to doripenem, imipenem, and meropenem, we found that against all pathogens combined, the MIC90 for ICU compared with non-ICU isolates was higher. Conclusions Doripenem showed similar or slightly better activity than meropenem and better activity than imipenem against the Gram-negative pathogens collected in Turkey. PMID:22340940

  3. Structure of GES-1 at Atomic Resolution: Insights Into the Evolution of Carbapenamase Activity in the Class a Extended-Spectrum Beta-Lactamases

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    Smith, C.A.; /SLAC, SSRL; Caccamo, M.; /Notre Dame U.; Kantardjieff, K.A.; /Cal State, Fullerton; Vakulenko, S.; /Notre Dame U.


    The structure of the class A extended-spectrum {beta}-lactamase GES-1 from Klebsiella pneumoniae has been determined to 1.1 Angstrom resolution. GES-1 has the characteristic active-site disulfide bond of the carbapenemase family of {beta}-lactamases and has a structure that is very similar to those of other known carbapenemases, including NMC-A, SME-1 and KPC-2. Most residues implicated in the catalytic mechanism of this class of enzyme are present in the GES-1 active site, including Ser70, which forms a covalent bond with the carbonyl C atom of the {beta}-lactam ring of the substrate during the formation of an acyl-enzyme intermediate, Glu166, which is implicated as both the acylation and deacylation base, and Lys73, which is also implicated as the acylation base. A water molecule crucial to catalysis is observed in an identical location as in other class A {beta}-lactamases, interacting with the side chains of Ser70 and Glu166. One important residue, Asn170, also normally a ligand for the hydrolytic water, is missing from the GES-1 active site. This residue is a glycine in GES-1 and the enzyme is unable to hydrolyze imipenem. This points to this residue as being critically important in the hydrolysis of this class of {beta}-lactam substrate. This is further supported by flexible-docking studies of imipenem with in silico-generated Gly170Asn and Gly170Ser mutant GES-1 enzymes designed to mimic the active sites of imipenem-hydrolyzing point mutants GES-2 and GES-5.

  4. Risk factors for and role of OprD protein in increasing minimal inhibitory concentrations of carbapenems in clinical isolates of Pseudomonas aeruginosa. (United States)

    Hirabayashi, Aki; Kato, Daizo; Tomita, Yuka; Iguchi, Mitsutaka; Yamada, Keiko; Kouyama, Yuichi; Morioka, Hiroshi; Tetsuka, Nobuyuki; Yagi, Tetsuya


    This study examined the risk factors for, and molecular mechanisms underlying, the increase in carbapenem minimum inhibitory concentrations (MICs) in clinical isolates of Pseudomonas aeruginosa. Consecutive clinical isolates of P. aeruginosa were collected. The MicroScan WalkAway system detected more than fourfold increases in the MICs of carbapenems in P. aeruginosa isolates serially recovered from some patients during their clinical course. The clinical risk factors associated with this increase were examined by multiple logistic regression analysis. Western blot analysis and nucleotide sequencing of the oprD gene of 19 clonally related and paired P. aeruginosa isolates from the same patients were undertaken to examine the mechanisms underlying the increase in MICs. The results showed that prior use of carbapenems (OR, 2.799; 95 % CI, 1.088-7.200; P=0.033) and the use of ventilators or tracheostomies (OR, 2.648; 95 % CI, 1.051-6.671; P=0.039) were risk factors for increased carbapenem MICs. Analysis of the underlying mechanisms revealed that loss of functional OprD protein due to mutation of the oprD gene tended to occur in P. aeruginosa isolates with imipenem MICs of more than 8 µg ml-1; a reduction in OprD expression was observed in P. aeruginosa isolates with imipenem MICs of 4 or 8 µg ml-1. This difference in the resistance mechanism was not correlated with the MICs of meropenem. This difference in the resistance mechanism of P. aeruginosa indicates a critical breakpoint at an imipenem MIC of 8 µg ml-1, in accordance with EUCAST criteria. Reducing carbapenem use will prevent P. aeruginosa clinical isolates from developing resistance to carbapenems.

  5. Carbapenems and piperacillin/tazobactam for the treatment of bacteremia caused by extended-spectrum β-lactamase-producing Proteus mirabilis. (United States)

    Tsai, Hsih-Yeh; Chen, Yen-Hsu; Tang, Hung-Jen; Huang, Chi-Chang; Liao, Chun-Hsing; Chu, Fang-Yeh; Chuang, Yin-Ching; Sheng, Wang-Huei; Ko, Wen-Chien; Hsueh, Po-Ren


    This study was intended to delineate the role of carbapenems and piperacillin/tazobactam in treating bacteremia caused by extended-spectrum β-lactamase (ESBL)-producing Proteus mirabilis. We performed a multicenter and retrospective study of the patients with ESBL-producing P. mirabilis bacteremia. The outcomes of the patients treated by piperacillin/tazobactam or a carbapenem for at least 48 hours and the MICs of the prescribed drugs for these isolates were analyzed. Forty-seven patients with available clinical data were included. The overall 30-day mortality rate was 29.8%. All available isolates (n = 44) were susceptible to ertapenem, meropenem, and doripenem, and 95.6% were susceptible to piperacillin/tazobactam; however, only 11.4% of the isolates were susceptible to imipenem. Among the 3 patients infected with isolates exhibiting non-susceptibility to imipenem (MIC ≥2 mg/L) who were treated with imipenem, none died within 28 days. The 30-day (14.3% versus 23.1%, P = 0.65) or in-hospital (19.1% versus 30.8%, P = 0.68) mortality rate of 21 patients treated by a carbapenem was lower than that of 13 treated by piperacillin/tazobactam. However, among those treated by piperacillin/tazobactam, the mortality rate of those infected by the isolates with lower piperacillin/tazobactam MICs (≤0.5/4 mg/L) was lower than that of the isolates with MICs of ≥1/4 mg/L (0%, 0/7 versus 60%, 3/5; P = 0.045). ESBL-producing P. mirabilis bacteremia is associated with significant mortality, and carbapenem therapy could be regarded as the drugs of choice. The role of piperacillin/tazobactam, especially for the infections due to the isolates with an MIC ≤0.5/4 mg/L, warrants more clinical studies. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Epidemiology of multi-resistance Gram negative pathogen circulating in Liguria and molecular characterization of different carbapenemases

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    Erika Coppo


    Full Text Available This study was conducted during January-April 2010 with the collaboration of 7 clinical microbiology laboratories evenly distributed across the Ligurian area to identify the most frequent Gram negative species and to evaluate their antibiotic susceptibility patterns Overall, 110 consecutive multi-resistant non duplicate Gram negative isolates,were collected and sent to the coordinating laboratory (Sezione di Microbiologia del DISC, University of Genoa, Italy together with susceptibility data obtained by routine methods. In addition, strains resistant to carbapenems were characterized by PCR. A total of 110 Gram negative multi-resistance strains were found, including 74 and 36 isolated from healthcare or nosocomial settings and community acquired infections, respectively. The most represented pathogens were: A. baumannii (38, 34.5%, E. coli (30, 27.2%, P. aeruginosa (29, 26.3%, K. pneumoniae (9, 8.2% and P. mirabilis (4, 3.6%. A. baumannii were more frequently collected from healthcare settings or nosocomial samples, while the other strains were generally equally isolated from in- and out-patients. Amikacin was the most active molecule against E. coli and P. mirabilis (96,7% and 100% of susceptible stains respectively. Colistin was the only active molecule agains A. baumanii and P. aeruginosa (100% of susceptible strains. Against K. pneumoniae tigecycline and colistin were the most active molecules (100% of susceptible strains. Imipenem was the most active compound against E. coli and P. mirabilis (100% of susceptible strains. A large number (97.4% of A. baumannii was resistant to imipenem. K. pneumoniae and P. aeruginosa showed rates of resistance of 88% and 34.4% respectively. A. baumannii, K. pneumoniae and P. aeruginosa isolates resistant to Imipenem, carried OXA-23, KPC and VIM carbapenemases.These data shown a significant spread of multidrug-resistant Gram negative bacteria in hospitals and in communities.The production of carbapenemase in

  7. Evaluation of antibiotic susceptibility of Bacteroides, Prevotella and Fusobacterium species isolated from patients of the N. N. Blokhin Cancer Research Center, Moscow, Russia. (United States)

    Shilnikova, Irina I; Dmitrieva, Natalia V


    In total 122 non-duplicate Bacteroides, Prevotella and Fusobacterium spp isolated from cancer patients between 2004 and 2014 were involved in this study. Most of the strains belonged to the B. fragilis group (55%), followed by Prevotella strains (34.4%) and Fusobacterium spp (10.6%). The species identification was carried out by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and they were identified on species level with a log (score) >2.0. The most common isolates were B. fragilis, B. thetaiotaomicron, B. ovatus and B. vulgatus. Among Prevotella species, the most frequently isolated species were P. buccae, P. buccalis, P. oris, P. denticola and P. nigrescens, and most of the Fusobacterium spp. were F. nucleatum. Susceptibilities of the strains were determined by the E-test methodology. The percentage of the susceptibility of B. fragilis group isolates were: metronidazole (MIC ≤4 μg/ml), 97%; imipenem (MIC ≤2 μg/ml), 95.5%; amoxicillin/clavulanate (MIC ≤4 μg/ml), 95.5% and clindamycin (MIC ≤4 μg/ml), 77.6%. Three B. fragilis isolates proved to be multidrug-resistant (parallel resistance to imipenem, amoxicillin/clavulanate and metronidazole or clindamycin was observed). All Prevotella strains tested were susceptible to imipenem and amoxicillin/clavulanate, whereas 78.6% of the pigmented Prevotella species and 46.4% of the non-pigmented species were resistant to penicillin (MIC >0.5 μg/ml). The susceptibility to metronidazole and clindamycin were 93% and 88%, respectively. All Fusobacterium strains were sensitive to all tested antibiotics, including penicillin. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Informing Antibiotic Treatment Decisions: Evaluating Rapid Molecular Diagnostics To Identify Susceptibility and Resistance to Carbapenems against Acinetobacter spp. in PRIMERS III. (United States)

    Evans, Scott R; Hujer, Andrea M; Jiang, Hongyu; Hill, Carol B; Hujer, Kristine M; Mediavilla, Jose R; Manca, Claudia; Tran, Thuy Tien T; Domitrovic, T Nicholas; Higgins, Paul G; Seifert, Harald; Kreiswirth, Barry N; Patel, Robin; Jacobs, Michael R; Chen, Liang; Sampath, Rangarajan; Hall, Thomas; Marzan, Christine; Fowler, Vance G; Chambers, Henry F; Bonomo, Robert A


    The widespread dissemination of carbapenem-resistant Acinetobacter spp. has created significant therapeutic challenges. At present, rapid molecular diagnostics (RMDs) that can identify this phenotype are not commercially available. Two RMD platforms, PCR combined with electrospray ionization mass spectrometry (PCR/ESI-MS) and molecular beacons (MB), for detecting genes conferring resistance/susceptibility to carbapenems in Acinetobacter spp. were evaluated. An archived collection of 200 clinical Acinetobacter sp. isolates was tested. Predictive values for susceptibility and resistance were estimated as a function of susceptibility prevalence and were based on the absence or presence of beta-lactamase (bla) NDM, VIM, IMP, KPC, and OXA carbapenemase genes (e.g., blaOXA-23, blaOXA-24/40, and blaOXA-58 found in this study) against the reference standard of MIC determinations. According to the interpretation of MICs, 49% (n = 98) of the isolates were carbapenem resistant (as defined by either resistance or intermediate resistance to imipenem). The susceptibility sensitivities (95% confidence interval [CI]) for imipenem were 82% (74%, 89%) and 92% (85%, 97%) for PCR/ESI-MS and MB, respectively. Resistance sensitivities (95% CI) for imipenem were 95% (88%, 98%) and 88% (80%, 94%) for PCR/ESI-MS and MB, respectively. PRIMERS III establishes that RMDs can discriminate between carbapenem resistance and susceptibility in Acinetobacter spp. In the context of a known prevalence of resistance, SPVs and RPVs can inform clinicians regarding the best choice for empiric antimicrobial therapy against this multidrug-resistant pathogen. Copyright © 2016 American Society for Microbiology.

  9. Contaminação fecal da ostra Crassostrea rhizophorae e da água de cultivo do estuário do Rio Pacoti (Eusébio, Estado do Ceará: Isolamento e identificação de Escherichia coli e sua susceptibilidade a diferentes antimicrobianos

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    Regine Helena Silva dos Fernandes Vieira


    Full Text Available This study has been designed to assess the microbiological quality of oyster Crassostrea rhizophorae and of the water used in farms located at the Pacoti River estuary, Ceará State, by means of the MPN of total coliforms (Ct and thermtolerant coliforms (CT. The database consisted of 15 samples collected from June to November, 2006. The water was kept within the limits set up by the current legislation. MPN values were in the ranges of <1.8 18,000 Ct per 100 ml and <1.8 2,000 CT per 100 ml, for the water, and <1.8 3,500 Ct per gram and <1.8 2,800 CT per gram for the oyster itself. Twenty-five strains isolated from the cultivation water and identified as Escherichia coli were tested for susceptibility to a few antimicrobians and proved resistant to ampicillin, nitrofurantoin, tetracycline, sulfazotrin, nalidixic acid, ciprofloxacin and imipenem. From the oysters, four strains were identified as E. coli and proved resistant to tetracycline and imipenem. From the afore-mentioned results, it can be concluded that: Pacoti River waters have received a clean bill of health according to the national legislation; the majority of water-isolated E.coli strains (59.43% were sensitive to the currently used antimicrobians, except for imipenem to which 80% of the identified E. coli strains proved resistant; sensitivity of the oyster-isolated E. coli strains was found to be high to most of the tested antimicrobians. In all, it is suggested that more clear management measures be made available so as to allow for microbiological quality evaluation of raw-consumed mollusks.

  10. Simulation of antibiotic pharmacodynamic exposure for the empiric treatment of nosocomial bloodstream infections: a report from the OPTAMA program. (United States)

    Maglio, Dana; Kuti, Joseph L; Nicolau, David P


    We developed a model to predict the pharmacodynamic exposure of antibiotics against bacteria commonly implicated in nosocomial bloodstream infections to determine which dosage regimens would provide the greatest likelihood of obtaining a bactericidal effect. Pharmacodynamic exposures were simulated for 5000 subjects receiving standard doses of ceftazidime, cefepime, piperacillin/tazobactam, meropenem, imipenem, or ciprofloxacin. Exposures were indexed to the MICs of bacteria weighted by their prevalence in causing nosocomial bloodstream infections, derived from 2002 SENTRY data. Enterococci were excluded. MIC data were derived from the 2003 Meropenem Yearly Surveillance Test Information Collection resistance study. The probabilities of achieving bactericidal exposures (ie, target attainment) for each antibiotic regimen were compared. The effect of increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) on attainment of bactericidal targets was tested. All dosage regimens except ciprofloxacin and ceftazidime 1 g q8h achieved >90% likelihood of bactericidal exposure. The rank order of target attainment was as follows: imipenem 500 mg q6h, 100.0%; imipenem 1 g q8h, 99.9%; cefepime 2 g q12h, 99.4%; meropenem 1 g q8h, 98.4%; cefepime 1 g q12h, 98.2%; piperacillin/tazobactam 3.375 g q6h, 97.9%; piperacillin/tazobactam 4.5 gq8h, 95.0%; ceftazidime 2 g q8h, 94.2%; ceftazidime 1 g q8h, 71.7%; ciprofloxacin 400 mg q8h, 63.3%; and ciprofloxacin 400 mg q12h,63.0%. Target attainments dropped to or =10% prevalence. The results of this model analysis suggest that standard doses of the carbapenems, piperacillin/tazobactam, and cefepime, and higher doses of ceftazidime, may provide optimal likelihood of achieving bactericidal exposure against pathogens implicated in nosocomial bloodstream infections, excluding MRSA and enterococci. When MRSA rates are > or =10%, therapy with an antibiotic that has activity against this phenotype should be empirically initiated.

  11. Cefotaxime and Amoxicillin-Clavulanate Synergism against Extended-Spectrum-β-Lactamase-Producing Escherichia coli in a Murine Model of Urinary Tract Infection. (United States)

    Rossi, B; Soubirou, J F; Chau, F; Massias, L; Dion, S; Lepeule, R; Fantin, B; Lefort, A


    We investigated the efficacies of cefotaxime (CTX) and amoxicillin (AMX)-clavulanate (CLA) (AMC) against extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli in vitro and in a murine model of urinary tract infection (UTI). MICs, the checkerboard dilution method, and time-kill curves were used to explore the in vitro synergism between cefotaxime and amoxicillin-clavulanate against two isogenic E. coli strains-CFT073-RR and its transconjugant, CFT073-RR Tc bla(CTX-M-15)-harboring a bla(CTX-M-15) plasmid and a bla(OXA-1) plasmid. For in vivo experiments, mice were separately infected with each strain and treated with cefotaxime, amoxicillin, and clavulanate, alone or in combination, or imipenem, using therapeutic regimens reproducing time of free-drug concentrations above the MIC (fT≥MIC) values close to that obtained in humans. MICs of amoxicillin, cefotaxime, and imipenem were 4/>1,024, 0.125/1,024, and 0.5/0.5 mg/liter, for CFT073-RR and CFT073-RR Tc bla(CTX-M-15), respectively. The addition of 2 mg/liter of clavulanate (CLA) restored the susceptibility of CFT073-RR Tc bla(CTX-M-15) to CTX (MICs of the CTX-CLA combination, 0.125 mg/liter). The checkerboard dilution method and time-kill curves confirmed an in vitro synergy between amoxicillin-clavulanate and cefotaxime against CFT073-RR Tc bla(CTX-M-15). In vivo, this antibiotic combination was similarly active against both strains and as effective as imipenem. In conclusion, the cefotaxime and amoxicillin-clavulanate combination appear to be an effective, easy, and already available alternative to carbapenems for the treatment of UTI due to CTX-M-producing E. coli strains. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  12. Comparative activity of carbapenem testing (the COMPACT study in Turkey

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    Leblebicioglu Hakan


    Full Text Available Abstract Background Recent evidence indicates that Gram-negative bacterial pathogens, the most common of which are Pseudomonas spp., Enterobacteriaceae, and Acinetobacter baumannii, are frequent causes of hospital-acquired infections. This study aims to evaluate the in vitro activity of doripenem and comparator carbapenem antibiotics against Gram-negative clinical isolates collected from COMParative Activity of Carbapenem Testing (COMPACT study centres in Turkey. Methods Ten centres in Turkey were invited to submit Pseudomonas aeruginosa, Enterobacteriaceae, and other Gram-negative isolates from intensive care unit (ICU/non-ICU patients with complicated intra-abdominal infections, bloodstream infections, or nosocomial pneumonia, including ventilator-associated pneumonia, between May and October 2008. Susceptibility was determined by each centre using E-test. A central laboratory performed species confirmation as well as limited susceptibility and quality-control testing. Results Five hundred and ninety six isolates were collected. MIC90 values for doripenem, meropenem, and imipenem, respectively, were 32, ≥ 64, and ≥ 64 mg/L against Pseudomonas spp.; 0.12, 0.12, and 0.5 mg/L against Enterobacteriaceae; and ≥ 64 mg/L for each against other Gram-negative isolates. In determining the susceptibility of hospital isolates of selected Gram-negative pathogens to doripenem, imipenem, and meropenem, we found that against all pathogens combined, the MIC90 for ICU compared with non-ICU isolates was higher. Conclusions Doripenem showed similar or slightly better activity than meropenem and better activity than imipenem against the Gram-negative pathogens collected in Turkey.

  13. Antibiotic Sensitivity Pattern of Staphylococcus aureus and Escherichia coli Isolated from Bovine Fresh Milk (POLA SENSITIVITAS ANTIBIOTIK TERHADAP STAPHYLOCOCCUS AUREUS DAN ESCHERICHIA COLI YANG DIISOLASI DARI SUSU SAPI SEGAR

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    Lucia Ratna Winata Muslimin


    Full Text Available The aims of this study were to determine the sensitivity of S.aureus and E. coli isolated fromfresh milk against against several antibiotics and to determine the safety of the milk for humancomsumsion. Milk was collected from milking diary cow and was used for the bacterial isolation. E.coli were were identified using Total Plate Count (TPC, Gram staining, their growth on Endo Agarand Eosin MethyleneBlue Agar, Biochemical analysis including glucose, lactose, sucrose,maltose, andsorbitol would be followed by Sorbitol Mac Conkey Agar Test for the identification of E.coliO157:H7.The isolation and identification of S.aureus were performed using Gram stain, TPC, growth on BairdParker Agar and Mannitol Salt Agar. S. aureus and S. epidermidis were differentiated by coagulaseand catalase tests. The antibiotic sensitivity tests for both S. aureus and E.coli were carried out usingthe following antibiotics: ampicillin, bacitracin, vancomycin, cefoperazone, ceftriaxone, cefotamine,cefuroxime, cefepime, cefazoline, ceftazidime, chloramphenicol, tetracycline, doxycycline, amikacin,kanamycin, neomycin, ertapenem, meropenem, imipenem, erythromycin, gentamycin, nalidixic acid,ciprofloxacin, levofloxacine, norfloxacine, ofloxacin, and novobiocin. Fresh milk obtained from thefarm was positive for S.aureus and E.coli and resistant to most antibiotics tested. The best antibioticsfor S. aureus were imipenem (54.1 mm, ampicillin (42.3 mm, cefazolin (41.6 mm, doxycycline (41.15mm, and for E.coli were Imipenem (30.1 mm, ertapenem (29.5 mm, and meropenem (25.35 mm. Thebovine fresh milk examined was contaminated by S.aureus and E.coli and to some extent, were alsoresistant to most antibiotics tested.

  14. Prevalence of metallo-beta-lactamase enzyme and patern of antibiotic resistance in Klebsiella pnomoniae isolated from patients with urinary tract infection in Qom city during 2013-2014

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    Rohollah Khodadadian


    Full Text Available Bachground: Klebsiella pnomoniae is one of the most important etiologic agents of urinary tract infection (UTI. An increasing occurrence of antimicrobial resistance among uropathogenic bacterial isolates has complicated the treatment process. The aim of this study was to determine antibiotic susceptibility patterns and prevalence of the metallo-beta-lactamase enzyme of K. pneumoniae isolates collected from UTI. Materials and Methods: This cross-sectional study was conducted on patients with complicated UTI reffered to hospitals in Qom city, Iran. A total of 1807 culture positive samples of pathogens were collected from the patients, among which 457 isolates were K. pneumoniae. The isolates were tested for antimicrobial susceptibility by the disc-diffusion method recommended by the guidelines of Clinical and Laboratory Standards Institute (CLSI 2013. In addition, the dubble disk synergy test was used to detect the K. pneumoniae isolates of metallo-beta-lactamase enzyme. Results: The prevalence of UTI infection due to K. pneumoniae was 25.3%. Among 1807 positive urine cultures, 62.4% were from females and 37.6% from males. Results of antimicrobial susceptibility showed that the highest antibiotic resistance was seen for trimetoprium-sulfametoxazole (98.5% and the lowest resistance levels were seen for amikacin (9.4%, meropenem (22.8% and imipenem (25.6%. The results of the imipenem-EDTA combined disk showed that 93.2% imipenem resistance isolates were positive for the metallo-beta- lactamase enzyme. Conclusion: Carbapenem resistance and production of the metallo-beta-lactamase enzyme in K. pneumoniae uropathogenic are increasing. However, amikacin is still effective against these bacterial infections and its effectiveness should be maintained.

  15. Crystal structures of covalent complexes of β-lactam antibiotics with E. coli penicillin-binding protein 5: toward an understanding of antibiotic specificity† (United States)

    Nicola, George; Tomberg, Joshua; Pratt, R. F.; Nicholas, Robert A.; Davies, Christopher


    Penicillin-binding proteins (PBPs) are the molecular target for the widely used β-lactam class of antibiotics, but how these compounds act at the molecular level is not fully understood. We have determined crystal structures of E. coli PBP5 as covalent complexes with imipenem, cloxacillin and cefoxitin. These antibiotics exhibit very different second order rates of acylation for the enzyme. In all three structures, there is excellent electron density for the central portion of the β-lactam, but weak or absent density for the R1 or R2 side chains. Areas of contact between the antibiotics and PBP 5 do not correlate with the rates of acylation. The same is true for conformational changes because although shift of a loop leading to an electrostatic interaction between Arg248 and the β-lactam carboxylate, which occurs completely with cefoxitin, partially with imipenem and is absent with cloxacillin, is consistent with the different rates of acylation, mutagenesis of Arg248 only decreased cefoxitin acylation two fold. Together, these data suggest that structures of post-covalent complexes of PBP 5 are unlikely to be useful vehicles for design of new covalent inhibitors of PBPs. Finally, superimposition of the imipenem-acylated complex with PBP5 in complex with a boronic acid peptidemimetic shows that the position corresponding to the hydrolytic water molecule is occluded by the ring nitrogen of the β-lactam. Since the ring nitrogen occupies a similar position in all three complexes, this supports the hypothesis that deacylation is blocked by the continued presence of the leaving group after opening of the β-lactam ring. PMID:20726582

  16. Crystal Structures of Covalent Complexes of [beta]-Lactam Antibiotics with Escherichia coli Penicillin-Binding Protein 5: Toward an Understanding of Antibiotic Specificity

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    Nicola, George; Tomberg, Joshua; Pratt, R.F.; Nicholas, Robert A.; Davies, Christopher (SC); (UNC); (Wesleyan)


    Penicillin-binding proteins (PBPs) are the molecular targets for the widely used {beta}-lactam class of antibiotics, but how these compounds act at the molecular level is not fully understood. We have determined crystal structures of Escherichia coli PBP 5 as covalent complexes with imipenem, cloxacillin, and cefoxitin. These antibiotics exhibit very different second-order rates of acylation for the enzyme. In all three structures, there is excellent electron density for the central portion of the {beta}-lactam, but weak or absent density for the R1 or R2 side chains. Areas of contact between the antibiotics and PBP 5 do not correlate with the rates of acylation. The same is true for conformational changes, because although a shift of a loop leading to an electrostatic interaction between Arg248 and the {beta}-lactam carboxylate, which occurs completely with cefoxitin and partially with imipenem and is absent with cloxacillin, is consistent with the different rates of acylation, mutagenesis of Arg248 decreased the level of cefoxitin acylation only 2-fold. Together, these data suggest that structures of postcovalent complexes of PBP 5 are unlikely to be useful vehicles for the design of new covalent inhibitors of PBPs. Finally, superimposition of the imipenem-acylated complex with PBP 5 in complex with a boronic acid peptidomimetic shows that the position corresponding to the hydrolytic water molecule is occluded by the ring nitrogen of the {beta}-lactam. Because the ring nitrogen occupies a similar position in all three complexes, this supports the hypothesis that deacylation is blocked by the continued presence of the leaving group after opening of the {beta}-lactam ring.

  17. Nitric oxide from IFNγ-primed macrophages modulates the antimicrobial activity of β-lactams against the intracellular pathogens Burkholderia pseudomallei and Nontyphoidal Salmonella.

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    Jessica Jones-Carson


    Full Text Available Our investigations show that nonlethal concentrations of nitric oxide (NO abrogate the antibiotic activity of β-lactam antibiotics against Burkholderia pseudomallei, Escherichia coli and nontyphoidal Salmonella enterica serovar Typhimurium. NO protects B. pseudomallei already exposed to β-lactams, suggesting that this diatomic radical tolerizes bacteria against the antimicrobial activity of this important class of antibiotics. The concentrations of NO that elicit antibiotic tolerance repress consumption of oxygen (O2, while stimulating hydrogen peroxide (H2O2 synthesis. Transposon insertions in genes encoding cytochrome c oxidase-related functions and molybdenum assimilation confer B. pseudomallei a selective advantage against the antimicrobial activity of the β-lactam antibiotic imipenem. Cumulatively, these data support a model by which NO induces antibiotic tolerance through the inhibition of the electron transport chain, rather than by potentiating antioxidant defenses as previously proposed. Accordingly, pharmacological inhibition of terminal oxidases and nitrate reductases tolerizes aerobic and anaerobic bacteria to β-lactams. The degree of NO-induced β-lactam antibiotic tolerance seems to be inversely proportional to the proton motive force (PMF, and thus the dissipation of ΔH+ and ΔΨ electrochemical gradients of the PMF prevents β-lactam-mediated killing. According to this model, NO generated by IFNγ-primed macrophages protects intracellular Salmonella against imipenem. On the other hand, sublethal concentrations of imipenem potentiate the killing of B. pseudomallei by NO generated enzymatically from IFNγ-primed macrophages. Our investigations indicate that NO modulates the antimicrobial activity of β-lactam antibiotics.

  18. Multiplication of blaOXA-23 is common in clinical Acinetobacter baumannii, but does not enhance carbapenem resistance. (United States)

    Hua, Xiaoting; Shu, Jianfeng; Ruan, Zhi; Yu, Yunsong; Feng, Ye


    To investigate the copy number of bla OXA-23 and its correlation with carbapenem resistance in carbapenem-resistant Acinetobacter baumannii (CRAB). A total of 113 bla OXA-23 -positive clinical CRAB isolates were collected from two hospitals in Zhejiang province, China. Their genetic relatedness was determined by MLST. The MIC of imipenem was determined using the agar diffusion method and the copy number of bla OXA-23 was measured using quantitative real-time PCR (qRT-PCR). The complete genomes of five clinical CRAB strains were sequenced using PacBio technology to investigate the multiplication mechanism of bla OXA-23 . Most of the isolates (100/113) belonged to global clone II and the MIC of imipenem ranged from 16 to 96 mg/L. The gene bla OXA-23 resided exclusively in Tn2006 or Tn2009. Approximately 38% of the isolates carried two or more copies of bla OXA-23 . The copy number of bla OXA-23 was not correlated with the MIC of imipenem. Within the five sequenced strains, multiple copies of bla OXA-23 were either tandemly clustered or independently inserted at different genomic sites. Multiplication of bla OXA-23 is common in CRAB, but does not enhance carbapenem resistance. Multiplication can be present in the form of either tandem amplifications or independent insertions at different sites. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail:

  19. Susceptibility of important Gram-negative pathogens to tigecycline and other antibiotics in Latin America between 2004 and 2010

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    Fernández-Canigia Liliana


    Full Text Available Abstract Background The Tigecycline Evaluation and Surveillance Trial (T.E.S.T. is a global surveillance study of antimicrobial susceptibility. This study reports data from Gram-negative isolates collected from centers in Latin America between 2004 and 2010. Methods Consecutive bacterial isolates were tested at each center using broth microdilution methodology as described by the Clinical Laboratory Standards Institute (CLSI. Susceptibility was determined using the CLSI interpretive criteria. For tigecycline the US Federal Drug Administration (FDA criteria were used. Results A total of 16 232 isolates were analyzed. Susceptibility to imipenem, meropenem, and tigecycline was >95% against both non-extended-spectrum β-lactamase (ESBL and ESBL producing Escherichia coli. Susceptibility to amikacin was also >95% for non-ESBL E. coli. 24.3% of E. coli were ESBL producers, ranging from 11.2% (58/519 in Colombia to 40.3% (31/77 in Honduras. Greater than 90% of non-ESBL Klebsiella pneumoniae were susceptible to tigecycline, carbapenems and amikacin. 35.3% of K. pneumoniae were ESBL producers, ranging from 17.2% (36/209 in Venezuela to 73.3% (55/75 in Honduras, with only imipenem and tigecycline maintaining >90% susceptibility. Greater than 90% of Klebsiella oxytoca, Enterobacter spp., and Serratia marcescens were susceptible to amikacin, carbapenems and tigecycline. The highest rates of susceptibility against Acinetobacter baumannii were seen for minocycline (89.4% and imipenem (62.5%, while 95.8% of the A. baumannii isolates displayed an MIC ≤2 μg/mL for tigecycline. Conclusions In this study carbapenems and tigecycline remain active against Enterobacteriaceae and A. baumannii; however, there is cause for concern with carbapenem non-susceptible isolates reported in all countries included in this study.

  20. [The relevance of correct identification and interpretation of susceptibility testing of Aeromonas spp. bacteremia isolates]. (United States)

    Ruiz-Castillo, Ana; Lepe-Jiménez, José Antonio; Torres-Sánchez, María José; Artacho-Reinoso, María José; Aznar-Martín, Javier


    To assess the relevance of correct identification and interpretation of susceptibility testing of Aeromonas spp. bacteremia isolates using newly developed molecular methods in comparison to previous conventional methods. The study included 22 patients with bacteremia due to Aeromonas hydrophila group, microbiologically characterized using the MicroScan system. Further identification to species level was performed by mass spectrometry, and confirmed by sequencing the rpoB gene. The MIC of imipenem, cefotaxime, piperacillin-tazobactam, ciprofloxacin and cotrimoxazole was studied using a commercial broth microdilution and antibiotic gradient strips with low and high inocula. Detection of carbapenemase production was performed using the modified Hodge test, and was confirmed by amplifying the cphA gene by PCR. A total of 9 (40.9%) isolates were identified as Aeromonas hydrophila, 8 (36.4%) as Aeromonas veronii, and the remaining 5 (22.7%) isolates as Aeromonas caviae. Resistance to beta-lactams according to both the commercial microdilution and MIC gradient strips methods was: 36%-50% to imipenem; 4%-56% to cefotaxime, and 27%-56% to piperacillin/tazobactam. The agreement between results generated by the automated system and the diffusion antibiotic gradient strip was, for all 3 species, 68% for imipenem, 50% to cefotaxime, and 46% to piperacillin/tazobactam. No resistance to cotrimoxazole and ciprofloxacin was found by either of the two methods, although 22.7% of the strains were resistant to nalidixic acid. It is essential to identify the isolates of Aeromonas spp. at the species level, due to the fact that beta-lactam resistance is species- and method-dependent. The high rate of resistance to beta-lactam and quinolones reduce their application as empiric treatments for invasive infection by Aeromonas ssp. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  1. Five-Year Antimicrobial Susceptibility Trends Among Bacterial Isolates from a Tertiary Health-Care Facility in Kigali, Rwanda. (United States)

    Carroll, Makeda; Rangaiahagari, Ashok; Musabeyezu, Emmanuel; Singer, Donald; Ogbuagu, Onyema


    Antimicrobial resistance (AMR) is a global public health threat. There is limited information from Rwanda on AMR trends. This longitudinal study aimed to describe temporal trends of antibiotic susceptibility among common bacteria. We collated the antimicrobial susceptibility results of bacteria cultured from clinical specimens collected from inpatients and outpatients and submitted to the microbiology laboratory at King Faisal Hospital, Kigali, Rwanda, from January 1, 2009, to December 31, 2013. Differences in antimicrobial susceptibility between the first and fifth year of the study for each bacterial species was assessed using χ(2) test. Of 5,296 isolates collected, 46.7% were Escherichia coli, 18.4% were Klebsiella spp., 5.9% were Acinetobacter spp., 7.1% were Pseudomonas spp., 11.7% were Staphylococcus aureus, and 10.3% were Enterococcus spp. Colistin and imipenem had greatest activity against gram-negative bacteria. Acinetobacter spp. showed the greatest resistance profile to antimicrobials tested, relative to other gram-negative bacteria. Vancomycin retained excellent activity against S. aureus and Enterococcus species (average susceptibility was 100% and 99.4%, respectively). Trend analysis determined that resistance to imipenem increased significantly among Klebsiella, E. coli, Pseudomonas, and Acinetobacter isolates; there was also rising resistance to colistin among E. coli and Pseudomonas species. Only E. coli demonstrated increased resistance to gentamicin. For gram-positive pathogens, vancomycin susceptibility increased over time for Enterococcus species, but was unchanged for S. aureus Our data suggest that resistance to imipenem and colistin are rising among gram-negative bacteria in Rwanda. Proper infection control practices and antimicrobial stewardship will be important to address this emerging threat. © The American Society of Tropical Medicine and Hygiene.

  2. Metallo- β-lactamases among Multidrug Resistant (MDR Gram Negative Bacteria Isolated from Clinical Specimens during 2009 in Sanandaj, Kurdistan Province

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    Himen Salimizand


    Full Text Available Background: Today, there are numerous reports about emerging multi drug resistant gram negative bacteria all around the world, especially in ICUs. Rarely, Metallo-β-lactamase (MBL enzymes are responsible for these cases. Study of MBLs for diagnosing and preventing distribution of the origin of infection are critical issues. In addition, we would like to compare the efficacy of Iranian and foreign- made antibiotic disks. Materials and Methods: During 2009 all entered clinical specimens to the laboratory tested for detecting gram negative bacteria. Isolated bacteria were tested by Kirby-Bauer method to antibiotic susceptibility test by Iranian and foreign (MAST disks. For gram negative carbapenem resistant isolates, PCR technique used to detect VIM, GIM, and SIM variants of MBLs.Results: During one year, 17890 clinical specimens referred Besat laboratory. The most specimen was Urine (8172 followed by blood culture (5190 that in which 1110 gram negative and positives isolated. Out of which, 778 (70% of isolates were gram negatives. MDR gram negatives were 157 (20.2%. Imipenem and meropenem were the most efficient antibiotics (all susceptible and ceftriaxone was the least (19 % susceptible. E. coli was the most prevalent isolate. 79 Gram negative isolates (10.1% were resistant to Iranian-made discs but all susceptible for foreign ones. All 79 isolates were tested by PCR for MBL genes, that, all were negative. Besides, Iranian imipenem and cefepime disks have had distinguishable difference in susceptibility of isolates.Conclusion: Fortunately, none of gram negative isolates were MBL producer, which revealed no colonization of MBL producing bacteria. Iranian-made disks appear efficient except for imipenem and cefepime.

  3. Susceptibilidad antimicrobiana de Staphylococcus aureus sensible, con sensibilidad "BORDERLINE" y resistentes a la meticilina

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    Carlos Alberto Mendoza Ticona


    Full Text Available Objetivo: Determinar las susceptibilidad a diversos antibacterianos de tres categorías de S. aureus según su sensibilidad a la meticilina. Materiales y Métodos: Se aislaron 76 cepas de S. aureus que colonizaban pacientes y personal de salud de tres servicios del Hospital Honorio Delgado de Arequipa, de los cuales 36 fueron sensibles a meticilina (MSSA, 15 con susceptibilidad "borderline" (BORSA y 25 fueron resistentes a la meticilina (MRSA. Se les sometió a antibiograma a 14 antibacterianos. Resultados: El único antibiótico al cual todas los aislamientos fueron sensibles fue vancomicina. Los MRSA fueron resistentes a todos los b-lactámicos excepto imipenem que obtuvo 64% de susceptibilidad. Los BORSA mantuvieron un 80% de sensibilidad a cefalotina y un 100% al imipenem. Los antibióticos cefalotina, imipenem, ciprofloxacina, cotrimoxazol, rifampicina, eritromicina, tetraciclina, cloranfenicol, lincomicina y gentamicina tuvieron sensibilidades variables (p<0.01 entre las tres categorías; una mayor proporción de MSSA fue sensible a estos antibióticos, luego los BORSA y finalmente los MRSA. Las cepas multi-resistentes fueron mucho más frecuentes en los MRSA que en los otros dos grupos (p <0.01. Conclusión: Existe en nuestro medio cepas de S. aureus con resistencia "borderline" a meticilina. Hay diferencias entre la sensibilidad a diversos antimicrobianos entre los tres grupos de S. aureus. Esta diferenciación podría beneficiar una terapia antimicrobiana más racional. Se debe aplicar en todo aislamiento de S. aureus las recomendaciones internacionales para la detección de meticilino resistencia.

  4. Sensibilidad antibiótica de bacterias obtenidas de queratitis e infecciones intraoculares en la Fundación Oftalmológica de Santander (FOSCAL, Floridablanca, Colombia

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    Virgilio Galvis


    Full Text Available Introducción. La resistencia bacteriana es crítica para la selección de los antibióticos en el tratamiento de las infecciones, por ello es vital conocer su estado actual en nuestro medio. Objetivo. Determinar la sensibilidad antibiótica bacteriana in vitro obtenida de los cultivos de queratitis e infecciones intraoculares. Materiales y métodos. Se llevó a cabo un estudio retrospectivo en la Fundación Oftalmológica de Santander (FOSCAL, entre junio de 2011 y enero de 2012. Resultados. Se examinaron 92 muestras. Se identificaron 110 bacterias, 27 hongos y 12 amebas de vida libre. Del total de bacterias Gram positivas, 1,1 %, 0 %, 1,1 %, 16,9 %, 29,3 % y 85 % fue resistente a imipenem, moxifloxacina, gatifloxacina, levofloxacina, ciprofloxacina y tobramicina, respectivamente, mientras que la resistencia a estos mismos fármacos se presentó, respectivamente, en 0 %, 8,3 %, 0 %, 0 %, 18,2 % y 27,3 % de las bacterias Gram negativas. Los porcentajes de resistencia de los estafilococos positivos para coagulasa resistentes a la meticilina fueron 0 %, 0 %, 0 %, 7 %, 17 % y 100 %, respectivamente, y los porcentajes de los estafilococos negativos para coagulasa resistentes a la meticilina fueron 3 %, 0 %, 0 %, 24 %, 44 % y 100 %, respectivamente. Los porcentajes de resistencia bacteriana globales (tanto para bacterias Gram positivas como para Gram negativas a imipenem, moxifloxacina, gatifloxacina, levofloxacina, ciprofloxacina y tobramicina fueron 1 %, 1 %, 1 %, 15,1 %, 28 % y 64,5 %, respectivamente. Conclusiones. Los niveles de resistencia bacteriana para imipenem, moxifloxacina y gatifloxacina fueron menores que para levofloxacina, ciprofloxacina y tobramicina. Los niveles de resistencia para la tobramicina fueron muy altos, lo que pone en duda su utilidad clínica en las infecciones oculares en nuestro medio.

  5. Non-susceptibility trends among Pseudomonas aeruginosa and other non-fermentative Gram-negative bacteria from bacteraemias in the UK and Ireland, 2001-06. (United States)

    Livermore, David M; Hope, Russell; Brick, Geraldine; Lillie, Mark; Reynolds, Rosy


    Pseudomonas and Acinetobacter spp. are important opportunists, notorious for resistance. Pseudomonas spp. are collected in the British Society for Antimicrobial Chemotherapy (BSAC) bacteraemia surveillance, with Acinetobacter spp. and Stenotrophomonas maltophilia well represented in the 'other Gram-negatives' group. Data for collected isolates were reviewed together with LabBase bacteraemia reports to the Health Protection Agency (HPA). Isolates with unusual resistances were subjected to molecular investigation. From 2001 to 2006, the BSAC surveillance collected 1226 Pseudomonas aeruginosa, 240 Acinetobacter spp.-125 of them Acinetobacter calcoaceticus/baumannii (Acb) complex-and 165 S. maltophilia. Among P. aeruginosa, non-susceptibility rates to beta-lactams and gentamicin fluctuated, without trend, below 10%; those to ciprofloxacin ranged from 16% to 22%. One P. aeruginosa isolate from 2001 had VIM-2 metallo-beta-lactamase. For Acb, the BSAC data indicated frequent non-susceptibility, except to imipenem, where only five non-susceptible isolates were collected, all after 2003, four of them belonging to the OXA-23 clone 1 lineage which is prevalent in Southeast England. Reports to the HPA indicated rising imipenem non-susceptibility in Acb (P /=16 mg/L for Acb OXA-23 clone 1. Ceftobiprole had higher MICs than ceftazidime for P. aeruginosa, but 81% of the isolates were inhibited at imipenem non-susceptibility emerging.

  6. Resistance Rates of Intra-Abdominal Isolates from Intensive Care Units and Non-Intensive Care Units in the United States: The Study for Monitoring Antimicrobial Resistance Trends 2010-2012. (United States)

    Hackel, Meredith A; Badal, Robert E; Bouchillon, Samuel K; Biedenbach, Douglas J; Hoban, Daryl J


    Enterobacteriaceae (3,235 isolates), Pseudomonas aeruginosa (476 isolates), and Acinetobacter baumannii (106 isolates) from inpatient intra-abdominal infections (IAIs) were collected for the 2010-2012 Study for Monitoring Antimicrobial Resistance Trends (SMART) program in the United States. This report evaluates the in vitro activity of several antimicrobial agents recommended for treatment of IAIs and compares profiles of isolates from intensive care units (ICUs) and non-intensive care units (non-ICUs). Gram-negative bacilli from hospitalized patients with IAIs were obtained each year from 2010-2012 from hospitals in the United States and tested for susceptibility to 12 antibiotics according to 2012 Clinical and Laboratory Standards Institute (CLSI) guidelines. The most active agents against members of the Enterobacteriaceae family from both ICUs and non-ICUs were amikacin, ertapenem, and imipenem-cilastatin, whereas the least active agent was ampicillin-sulbactam. Amikacin was the only agent with good activity against P. aeruginosa, whereas none of the agents tested exhibited substantial activity against A. baumannii. Amikacin, ceftazidime, ceftriaxone, ciprofloxacin, levofloxacin, and imipenem-cilastatin were significantly less active against Enterobacteriaceae from ICU patients, whereas cefepime and ceftazidime were significantly less active against P. aeruginosa from ICU patients. Intensive care unit isolates were more likely to be multi-drug-resistant than non-ICU isolates, although there was no difference in extended-spectrum β-lactamase (ESBL) production rates between the two patient groups. Despite increasing resistance trends, in this study amikacin, ertapenem, and imipenem-cilastatin were shown to have good in vitro activity against the most frequently isolated gram-negative bacilli from IAIs in ICU and non-ICU settings.

  7. Naphthacemycins, novel circumventors of β-lactam resistance in MRSA, produced by Streptomyces sp. KB-3346-5. I. The taxonomy of the producing strain, and the fermentation, isolation and antibacterial activities. (United States)

    Fukumoto, Atsushi; Kim, Yong-Pil; Matsumoto, Atsuko; Takahashi, Yoko; Suzuki, Makoto; Onodera, Hideyuki; Tomoda, Hiroshi; Matsui, Hidehito; Hanaki, Hideaki; Iwatsuki, Masato; Ōmura, Satoshi; Shiomi, Kazuro


    Screening for circumventors of β-lactam resistance in methicillin-resistant Staphylococcus aureus (MRSA) led us to find 17 novel antibiotics, naphthacemycins A 1 -A 11 , B 1 -B 4 and C 1 -C 2 . The naphthacemycins were isolated from a cultured broth of Streptomyces sp. KB-3346-5 by repeated silica gel column chromatography and HPLC. Naphthacemycins enhanced imipenem activity 100-500 times against MRSA at 0.5 μg ml -1 , and naphthacemycins A 4 -A 11 themselves showed MIC 50 values of 1-4 μg ml -1 against 22 MRSA strains.

  8. In Vitro Activities of Tigecycline and Eight Other Antimicrobials against Different Nocardia Species Identified by Molecular Methods▿


    Cercenado, Emilia; Marín, Mercedes; Sánchez-Martínez, Mónica; Cuevas, Oscar; Martínez-Alarcón, José; Bouza, Emilio


    The in vitro activities of tigecycline and other antimicrobials against 51 isolates of Nocardia spp. were evaluated. MIC90s and MIC ranges were as follows: tigecycline, 4 and ≤0.06 to 8 mg/liter, respectively; minocycline, 2 and ≤0.06 to 2 mg/liter, respectively; linezolid, 1 and ≤0.06 to 2 mg/liter, respectively; moxifloxacin, 2 and ≤0.06 to >64 mg/liter, respectively; ertapenem, 32 and ≤0.06->64 mg/liter, respectively; imipenem, 2 and ≤0.06 to >64 mg/liter, respectively; meropenem, 8 and ≤0...

  9. In vitro Evaluation of the Colistin-Carbapenem Combination in Clinical Isolates of A. baumannii Using the Checkerboard, Etest, and Time-Kill Curve Techniques

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    Micheline A. H. Soudeiha


    Full Text Available The worldwide increase in the emergence of carbapenem resistant Acinetobacter baumannii (CRAB calls for the investigation into alternative approaches for treatment. This study aims to evaluate colistin-carbapenem combinations against Acinetobacter spp., in order to potentially reduce the need for high concentrations of antibiotics in therapy. This study was conducted on 100 non-duplicate Acinetobacter isolates that were collected from different patients admitted at Saint George Hospital-University Medical Center in Beirut. The isolates were identified using API 20NE strips, which contain the necessary agents to cover a panel of biochemical tests, and confirmed by PCR amplification of blaOXA−51−like. Activities of colistin, meropenem and imipenem against Acinetobacter isolates were determined by ETEST and microdilution methods, and interpreted according to the guidelines of the Clinical and Laboratory Standards Institute. In addition, PCR amplifications of the most common beta lactamases contributing to carbapenem resistance were performed. Tri locus PCR–typing was also performed to determine the international clonality of the isolates. Checkerboard, ETEST and time kill curves were then performed to determine the effect of the colistin-carbapenem combinations. The synergistic potential of the combination was then determined by calculating the Fractional Inhibitory Concentration Index (FICI, which is an index that indicates additivity, synergism, or antagonism between the antimicrobial agents. In this study, 84% of the isolates were resistant to meropenem, 78% to imipenem, and only one strain was resistant to colistin. 79% of the isolates harbored blaOXA−23−like and pertained to the International Clone II. An additive effect for the colistin-carbapenem combination was observed using all three methods. The combination of colistin-meropenem showed better effects as compared to colistin-imipenem (p < 0.05. The colistin-meropenem and

  10. Detection of antimicrobial sensitiveness of isolates of Listeria monocytogenes from food chain using Vitek 2 Compact Biomerieux

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    Jankuloski Dean


    Full Text Available Sensitivity of 26 Listeria monocytogenes isolates toward 18 antimicrobial substances used in veterinary and human medicine was examined using the automated VITEK 2 Compact system bioMerieux. The obtained results indicate that L. monocytogenes strains isolated from food and food processing environment had resistance to several or more antimicrobial substances that are commonly used in the treatment in animals and humans. Results showed resistance of all 26 (100% isolates toward Benzylpenicilin, Ampicilin/Sublactam, Oxacillin, Imipenem and Fosfomycine. Also 7 of the isolates (26.9% were resistant to Clindamiycin, 3 (11.5% to Quinupristion/Dalfopristin and 1 strain to Teicoplanin, Vancomycin, Tetracycline and Fusic acid, respectively.

  11. Estudio comparativo de la actividad antimicrobiana de diferentes presentaciones comerciales de antibióticos de administración intravenosa a través de métodos in vitro


    Meléndez, Pilar; Díaz, Jorge; Silva, Edelberto; González, Pedro; Moreno, Eva; Amaya, Pablo; Serrato, Numael; Sáenz, Edgar


    En este trabajo, se desarrollaron bioensayos para la valoración de ceftriaxona, cefotaxima, ceftazidima, ampicilina/sulbactam e imipenem/cilastatina. Se pudo establecer un único microorganismo (esporas de Bacillus subtilis ATCC 6633) para la ejecución del bioensayo. El rango de concentración que tiene la mejor correlación dosis-respuesta es propio de cada antibiótico, al igual que las condiciones del ensayo (pH de la solución de antibiótico, pH de medio de cultivo, tiempo de incubación). Con ...

  12. The first report of infection with Klebsiella pneumoniae carrying the bla kpc gene in State of Mato Grosso do Sul, Brazil

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    Marilene Rodrigues Chang


    Full Text Available The increased frequency and dissemination of enterobacteria resistant to various antimicrobials is currently worldwide concern. In January 2010, a 94-year-old patient with chronic lymphocytic leukemia was admitted to the University Hospital. This patient died 21 days after hospitalization due to the clinical worsening. Klebsiella pneumoniae producing of extended-spectrum β-lactamases (ESBLs was isolated of urine culture. This bacterium demonstrated resistance to ceftazidime, ciprofloxacin, levofloxacin, ertapenem and imipenem. Susceptibility to cefoxitin, cefepime, meropenem, colistin and tigecycline. This study reports the first case of infection by Klebsiella pneumoniae carrying the bla kpc gene in the State of Mato Grosso do Sul, Brazil.

  13. Epidemiological study of pathogens isolated from blood in Liguria (January-April 2010

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    Ramona Barbieri


    Full Text Available Objectives. An epidemiological study to identify the most represented pathogens isolated from blood and to evaluate their antibiotic susceptibility patterns, was conducted. Methods. Seven clinical microbiology laboratories, homogeneously distributed in the Ligurian area,were required to collected all consecutive non-duplicates strains isolated froom blood cultures during January 2010 to April 2010. The strains were sent to the reference laboratory (Sezione di Microbiologia del DISC, University of Genoa, Italy. Results. A total of 277 microorganisms were enrolled, including 155 Gram positive and 122 Gram negative.The most represented pathogens were: Escherichia coli (68, Staphylococcus aureus (57, Staphylococcus epidermidis (32, Staphylococcus hominis (17, Pseudomonas aeruginosa (15, Klebsiella pneumoniae (15, Enterococcus faecalis (11. Samples were collected mainly from medicine (66, 33.3%, of this number was determined by E. coli, intensive care units (33, 18.2% of this number consisted of S. epidermidis, surgery (24, 33.3% consisted of E. coli and infectious diseases (20, of which S. aureus, E. coli and S. epidermidis equally represented 20.0%.Among the Staphylococci the most active molecules were: vancomycin and teicoplanin (100% of susceptible strains, chloramphenicol (92.3% and trimethoprim-sulfamethoxazole (89.8%. Among the OXA-R Staphylococci (81/123, 65.9% the most active molecules were: vancomycin and teicoplanin (100% of susceptible strains, chloramphenicol (93.8% and trimethoprim-sulfamethoxazole (84.8%. Enterococci showed rates of resistance to vancomycin of 5.9%. Enterobacteriaceae exhibited resistance to ampicillin (77.5%, trimethoprim-sulfamethoxazole (42.6%, ciprofloxacin (41.2%, ceftriaxone (37.5%, ceftazidime (28.2%, cefepime (26.7%, cefoxitin (22.1%, piperacillintazobactam (20.4%, imipenem (4.7% and amikacin (2.9%. The Gram negative non-Enterobacteriaceae showed rates of resistance of 100% to ceftriaxone, 81.3% to trimethoprim

  14. Nocardia abscessus brain abscess in an immunocompetent host. (United States)

    Al Tawfiq, Jaffar A; Mayman, Talal; Memish, Ziad A


    Nocardia brain abscesses typically occur in immunocompromised patients. Most cases of nocardiosis are caused by the Nocardia asteroides complex and Nocardia brasiliensis. Here, we present a patient with a Nocardia abscessus brain abscess. The diagnosis was confirmed by DNA sequencing, and the organism was susceptible to linezolid, clarithromycin, ceftriaxone, imipenem, tobramycin, amikacin, minocycline and sulfamethoxazole. The patient was successfully treated medically in combination with surgical excision. Copyright © 2013 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  15. Multidrug-resistant Acinetobacter baumannii infection following para-articular steroid injection in the knee--a case report. (United States)

    Artiaco, Stefano; Cicero, Giuseppe; Bellomo, Franco; Bianchi, Pasquale


    Acinetobacter baumannii is an emerging gram-negative nosocomial pathogen that rarely causes infections in orthopaedic patients. We report a case of imipenem-resistant Acinetobacter baumannii paraarticular infection of the knee occurring in a healthy patient following one ambulatory steroid injection for the treatment of quadriceps tendinopathy. The infection was reduced by early surgical debridement of infected tissues, abscess drainage, and prolonged antibiotic therapy with colistin. To our knowledge, this is the first case in the literature reporting such an infection following single steroid injection in orthopaedic patients.

  16. Carbapenem-Resistant Strain of Klebsiella oxytoca Harboring Carbapenem-Hydrolyzing β-Lactamase KPC-2 (United States)

    Yigit, Hesna; Queenan, Anne Marie; Rasheed, J. Kamile; Biddle, James W.; Domenech-Sanchez, Antonio; Alberti, Sebastian; Bush, Karen; Tenover, Fred C.


    We investigated a Klebsiella oxytoca isolate demonstrating resistance to imipenem, meropenem, extended-spectrum cephalosporins, and aztreonam. The MICs of both imipenem and meropenem were 32 μg/ml. The β-lactamase activity against imipenem and meropenem was inhibited in the presence of clavulanic acid. Isoelectric focusing studies demonstrated five β-lactamases with pIs of 8.2 (SHV-46), 6.7 (KPC-2), 6.5 (unknown), 6.4 (probable OXY-2), and 5.4 (TEM-1). The presence of the blaSHV and blaTEM genes was confirmed by specific PCR assays and DNA sequence analysis. Transformation and conjugation studies with Escherichia coli showed that the β-lactamase with a pI of 6.7, Klebsiella pneumoniae carbapenemase-2 (KPC-2), was encoded on an approximately 70-kb conjugative plasmid that also carried SHV-46, TEM-1, and the β-lactamase with a pI of 6.5. The blaKPC-2 determinant was cloned in E. coli and conferred resistance to imipenem, meropenem, extended-spectrum cephalosporins, and aztreonam. The amino acid sequence of KPC-2 showed a single amino acid difference, S174G, when compared with KPC-1, another carbapenem-hydrolyzing β-lactamase from K. pneumoniae 1534. Hydrolysis studies showed that purified KPC-2 hydrolyzed not only carbapenems but also penicillins, cephalosporins, and aztreonam. KPC-2 had the highest affinity for meropenem. The kinetic studies revealed that KPC-2 was inhibited by clavulanic acid and tazobactam. An examination of the outer membrane proteins of the parent K. oxytoca strain demonstrated that it expressed detectable levels of OmpK36 (the homolog of OmpC) and a higher-molecular-weight OmpK35 (the homolog of OmpF). Thus, carbapenem resistance in K. oxytoca 3127 is due to production of the Bush group 2f, class A, carbapenem-hydrolyzing β-lactamase KPC-2. This β-lactamase is likely located on a transposon that is part of a conjugative plasmid and thus has a very high potential for dissemination. PMID:14638498

  17. Susceptibility trends of Bacteroides fragilis group and characterisation of carbapenemase-producing strains by automated REP-PCR and MALDI TOF. (United States)

    Treviño, Mercedes; Areses, Paloma; Peñalver, M Dolores; Cortizo, Sandra; Pardo, Fernanda; del Molino, M Luisa Pérez; García-Riestra, Carlos; Hernández, Manuela; Llovo, José; Regueiro, Benito J


    Susceptibility testing of clinical isolates of anaerobic bacteria is not considered, often, mandatory in routine clinical practice and the treatments are empirically established. Thus, periodic monitoring of the susceptibility patterns of anaerobic bacteria is advisable. The aim of this study was to update on resistance of Bacteroides fragilis group in our Institution with special attention to carbapenems reporting metallo-beta-lactamase producing strains for the first time in Spain, and to compare fingerprinting analysis results obtained by using automated rep-PCR (DiversiLab System) and MALDI-TOF MS. A total of 830 non-duplicated clinical isolates of the B. fragilis group recovered from the years 2006 to 2010 were studied. B. fragilis was the most prevalent species (59.5%). The total susceptibility of B. fragilis group isolates were: penicillin, 13.3%; amoxicillin/clavulanic, 89.6%; piperacillin-tazobactam, 91.8%; cefoxitin, 65.8%; ertapenem, 95.9%; imipenem, 98.2%; clindamycin, 53.4% and metronidazole, 96.4%. The percentage of sensitive isolates did not change significantly over time for amoxicillin/clavulanic, cefoxitin, clindamycin and metronidazole. A slight increase in the rate of resistance to ertapenem and imipenem was observed. Imipenem resistance and carbapenemase production were detected for the first time in our laboratory in the year 2007. No other report of carbapenemase-producing B. fragilis in our country has been previously published. Six imipenem-resistant isolates were MBL-producing and PCR positive for cfiA gene. Four of them were PCR positive for IS-like immediately upstream cfiA gene and two of them were negative. Both, automated rep-PCR (DiversiLab) and MALDI-TOF MS, revealed a great genetic diversity among carbapenem-producing strains suggesting the acquisition of novel resistance genes more than clonal dissemination of them. Both methods seem to be useful tools for fast and accurate identification and strain typing of B. fragilis group in

  18. High resistance rate against 15 different antibiotics in aerobic gram-negative bacteria isolates of cardiology intensive care unit patients

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    Küçükates E


    Full Text Available Aerobic gram negative bacteria were isolated and examined microbiologically from various clinical samples of 602 patients hospitalized between January 1997 and December 2000 in surgical and coronary intensive care units (ICUs. A total of 827 isolates were obtained from 602 patients. The majority of microorganisms were isolated from the respiratory tract (50.3% and blood (39.9%. Pseudomonas spp. were the most frequently isolated gram negative species (32.7%, followed by Acinetobacter spp. (24.0% and Klebsiella pneumoniae (19.4%. High resistance rates to all antibiotics studied were observed. Imipenem and meropenem were the most effective antibiotics against gram negatives.

  19. Selective enumeration and viability of Bifidobacterium animalis subsp. lactis in a new fermented milk product Enumeração seletiva e viabilidade de Bifidobacterium animalis subsp. lactis em um novo produto lácteo fermentado

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    Adriane Elisabete Costa Antunes


    Full Text Available One of the key focuses of today's dairy industry worldwide is the continued development of new products, especially probiotic-based products. Buttermilk is originally a by-product of butter making fermented by Mesophilic Aromatic Cultures (MAC. It can also be made by fermentation of pasteurized whole milk or skimmed milk. This product is not marketed in Brazil. The objectives of this work were: (1 to develop a selective medium for Bifidobacterium animalis subsp. lactis enumeration and (2 to determine the viability of this microorganism during the shelf life of the buttermilk. Skim milk added with 10% sucrose or 0.03% sucralose was pasteurized and inoculated with a composite starter culture consisting of 1% MAC (containing Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. lactis biovar. diacetylactis and Leuconostoc mesenteroides subsp. cremoris and 2% Bifidobacterium animalis subsp. lactis. To attain selective counts of Bif. animalis subsp. lactis the MRS agar supplemented with 0.5% L-cysteine hydrochloride at 10%, 1% lithium chloride at 10%, 0.01% aniline blue and 0.5% dicloxacillin at 0.1% was modified by increasing the antibiotic concentration, addition of NaCl, adjusting pH to 4.8 or increasing the incubation temperature (from 37 to 45ºC. Raising the incubation temperature to 45ºC was found to be efficient in inhibiting the MAC cultures, even in media not added with dicloxacillin. Bif. animalis subsp. lactis exhibited high viability in the product. The buttermilk product prepared with sucrose and sweetener contained in excess of 10(8 bifidobacteria throughout the shelf life of the product (28 days.Atualmente, um dos principais focos da indústria de laticínios em todo o mundo é o desenvolvimento de novos produtos, especialmente probióticos. Buttermilk é originalmente um sub-produto do processamento da manteiga fermentado por Culturas Aromáticas Mesofílicas (MAC. Pode também ser

  20. A gold immunochromatographic assay for the rapid and simultaneous detection of fifteen β-lactams (United States)

    Chen, Yanni; Wang, Yongwei; Liu, Liqiang; Wu, Xiaoling; Xu, Liguang; Kuang, Hua; Li, Aike; Xu, Chuanlai


    A novel gold immunochromatographic assay (GICA) based on anti-β-lactam receptors was innovatively developed that successfully allowed rapid and simultaneous detection of fifteen β-lactams in milk samples in 5-10 minutes. By replacing the antibodies used in traditional GICA with anti-β-lactam receptors, the difficulty in producing broad specific antibodies against β-lactams was overcome. Conjugates of ampicillin with BSA and goat anti-mouse immunoglobulin (IgG) were immobilized onto the test and control lines on the nitrocellulose membrane, respectively. Since goat anti-mouse IgG does not combine with receptors, negative serum from mice labelled with gold nanoparticles (GNP) was mixed with GNP-labelled receptors. Results were obtained within 20 min using a paper-based sensor. The utility of the assay was confirmed by the analysis of milk samples. The limits of detection (LOD) for amoxicillin, ampicillin, penicillin G, penicillin V, cloxacillin, dicloxacillin, nafcillin, oxacillin, cefaclor, ceftezole, cefotaxime, ceftiofur, cefoperazone, cefathiamidine, and cefepime were 0.25, 0.5, 0.5, 0.5, 1, 5, 5, 10, 25, 10, 100, 10, 5, 5, and 2 ng mL-1, respectively, which satisfies the maximum residue limits (MRL) set by the European Union (EU). In conclusion, our newly developed GICA-based anti-β-lactam receptor assay provides a rapid and effective method for one-site detection of multiple β-lactams in milk samples.A novel gold immunochromatographic assay (GICA) based on anti-β-lactam receptors was innovatively developed that successfully allowed rapid and simultaneous detection of fifteen β-lactams in milk samples in 5-10 minutes. By replacing the antibodies used in traditional GICA with anti-β-lactam receptors, the difficulty in producing broad specific antibodies against β-lactams was overcome. Conjugates of ampicillin with BSA and goat anti-mouse immunoglobulin (IgG) were immobilized onto the test and control lines on the nitrocellulose membrane, respectively

  1. Endophthalmitis caused by Pantoea agglomerans: clinical features, antibiotic sensitivities, and outcomes

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    Venincasa VD


    Full Text Available Vincent D Venincasa, Ajay E Kuriyan, Harry W Flynn Jr, Jayanth Sridhar, Darlene Miller Department of Ophthalmology, Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA Purpose: To report the clinical findings, antibiotic sensitivities, and visual outcomes associated with endophthalmitis caused by Pantoea agglomerans.Methods: A consecutive case series of patients with vitreous culture-positive endophthalmitis caused by P. agglomerans from January 1, 1990 to December 31, 2012 at a large university referral center. Findings from the current study were compared to prior published studies.Results: Of the three study patients that were identified, clinical settings included trauma (n=2 and post-cataract surgery (n=1. Presenting visual acuity was hand motion or worse in all three cases. All isolates were sensitive to ceftazidime, gentamicin, imipenem, and fluoroquinolones. All isolates were resistant to ampicillin. Initial treatment strategies were vitreous tap and intravitreal antibiotic injection (n=1 and pars plana vitrectomy with intravitreal antibiotic injection (n=2. At last follow-up, one patient had no light perception vision, while the other two had best-corrected visual acuity of 20/200 and 20/400.Conclusion: All Pantoea isolates were sensitive to ceftazidime, gentamicin, imipenem, and fluoroquinolones. All patients in the current study received at least one intravitreal antibiotic to which P. agglomerans was shown to be sensitive in vitro. In spite of this, the visual outcomes were generally poor.Keywords: ocular infection, trauma, antibiotic resistance

  2. Etiological and Resistance Profile of Bacteria Involved in Urinary Tract Infections in Young Children

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    Antonio Sorlózano-Puerto


    Full Text Available Background. The objective of this study was to identify the bacteria most frequently responsible for urinary tract infection (UTI in the population of under-2-year-olds in our geographic area and to evaluate the activity of antibiotics widely used for UTI treatment during a 4-year study period. Materials and Methods. A retrospective analysis was conducted of data on the identification and susceptibility of microorganisms isolated in urine samples from children under 2 years of age. Results. A total of 1,045 uropathogens were isolated. Escherichia coli accounted for the majority (60.3% of these, followed by Enterococcus faecalis (22.4% and Klebsiella spp. (6.5%. The highest E. coli susceptibility rates (>90% were to piperacillin-tazobactam, cefuroxime, cefotaxime, ceftazidime, imipenem, gentamicin, nitrofurantoin, and fosfomycin, and the lowest were to amoxicillin-clavulanic acid and cotrimoxazole. Among all bacteria isolated, we highlight the overall high activity of piperacillin-tazobactam, imipenem, nitrofurantoin, and fosfomycin against both community and hospital isolates and the reduced activity of amoxicillin-clavulanic acid, cephalosporins, gentamicin, and cotrimoxazole. There was no significant change in the total activity of any of the studied antibiotics over the 4-year study period. Conclusion. Empiric treatment with amoxicillin-clavulanic acid, cotrimoxazole, cephalosporins, and gentamicin may be inadequate due to their limited activity against uropathogens in our setting.

  3. Detection of coliform bacteria, determination of phylogenetic typing and antibiotic resistance profile of Escherichia coli in qanats and springs of East-Azerbaijan province

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    N. Shabani Lokarani


    Full Text Available Escherichia coli as a fecal contamination and is considered as an index in water. The aim of this study was to determine the phenotypic and genotypic characteristics of E. coli and antibiotic resistance of the isolates collected from qanats and springs in East-Azerbaijan province. For this purpose, 118 samples were selected from above mentioned area and examined by MPN method. The positive coliform samples were identified by phenotypic and genotypic methods. Afterwards, to determine the genetic diversity of E. coli isolates, phylogenetic typing we conducted by means of multiplex PCR. To determine the antibiotic resistance profile, antibiotic discs of Nalidixic Acid, Co-trimoxazol, Amoxicillin, Gentamaicin Ciprofloxacin, Chloramphenicol, Imipenem, Cefotaxime and Ceftazidime antibiogram were used. Based on results, 48% of the samples were evaluated as positive for coliform including 40% for E. coli and 19% for Klebsiella. Amongst 23 isolates confirmed as E. coli by PCR. Phylogenetic typing revealed  that 44% of E. coli strains belonged to type D and B2 and 56% belonged to A and B1 phylotypes. Antimicrobial susceptibility pattern showed that 92% of E. coli isolates were resistant to Amoxicillin. All E. coli isolates were sensitive to Imipenem. It was concluded that presence of pathogenic E. coli with high rate of antibacterial resistance in waters source could be considered as a human health hazard.

  4. Antibacterial and anti-biofilm activities of melittin and colistin, alone and in combination with antibiotics against Gram-negative bacteria. (United States)

    Dosler, Sibel; Karaaslan, Elif; Alev Gerceker, A


    In vitro antibacterial and anti-biofilm activities of antimicrobial cationic peptides (AMPs) - melittin and colistin - both alone and in combination with antibiotics were evaluated against clinical isolates of Gram-negative bacteria. Minimum inhibitory concentration (MIC) and fractional inhibitory concentration (FIC) index were determined by the microbroth dilution and chequerboard techniques, respectively. The time-kill curve (TKC) method was used for determining the bactericidal activities of AMPs alone and in combination. Measurements of anti-biofilm activities were performed spectrophotometrically for both inhibition of attachment and 24-hour biofilm formation at MIC or subMIC. According to MIC90 values, the most active agents against Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae were colistin, imipenem and ciprofloxacin, respectively. In combination studies, synergistic effects were mostly seen with colistin-imipenem against E. coli and K. pneumoniae (50 and 54%, respectively), colistin-ciprofloxacin against P. aeruginosa (77%). In TKC studies, synergism was observed with almost all expected combinations, even more frequently than chequerboard method. All of the antimicrobial agents were able to inhibit attachment and 24-hour biofilm formation between 0-57% at 1/10 × MIC and 7-73% at 1 × or 1/10 × MIC, respectively. AMPs seem to be a good candidate for antimicrobial chemotherapy with their antibacterial and anti-biofilm activities as a single agent or in combination with antibiotics.

  5. The isolation and preliminary characterization of native cyanobacterial and microalgal strains from lagoons contaminated with petroleum oil in Khark Island

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    Mostafa Noroozi


    Full Text Available Introduction: Algae has many applications in terms of ecology, biodiversity, agriculture, medicine, biotechnology, industry, etc. They are potent organisms in bio-active compound production, bioremediation and primary producer. Therefore, it is important to discover local strains with biotechnological and ecological applications. Materials and methods: Soil and water samples were collected from different sites of Khark Island (Persian Gulf. The samples were cultivated and purified using different techniques. Seven different antibiotics together with other physical methods used to purify the isolates. Results: Throughout the project 7 strains including 2 eukaryotic algae and 5 cyanobacteria have been isolated. Imipenem and cycloheximide were the best antibiotics for purification of cultures. Three of isolates were morphologically similar to Arthronema africanum, Pseudanabaena teremula, Anabaenopsis sp. However, they have some different characteristics which according to the present identification keys it is not possible to identify their identity (they have nominated Kh.C.d2, Kh.T.1 and Kh.T.2. Discussion and conclusion: According to the results, isolated strains were identified at the genus level based on morphology characters; therefore the complementary examinations such as molecular identification, ITS, 18s rRNA, 16s rRNA and sequencing can help to approve the strains identity. Upon approval of the new strains account for morphological traits are necessary for their easy identification. The Imipenem antibiotic is the best for eukaryotic algae purification and Cycloheximide is suitable for prokaryotic algae (cyanobacteria purification.

  6. Molecular epidemiology of SPM-1-producing Pseudomonas aeruginosa by rep-PCR in hospitals in Parana, Brazil. (United States)

    Kalluf, K O; Arend, L N; Wuicik, T E; Pilonetto, M; Tuon, F F


    Infections caused by multidrug resistant microorganisms are a global health problem, and Pseudomonas aeruginosa is an important nosocomial pathogen, easily disseminated in the hospital environment. The aim of this study was to determine SPM-1 in P. aeruginosa strains in 30 Brazilian hospitals and the genetic similarity of isolates. We analyzed 161 isolates of carbapenem-resistant P. aeruginosa. Imipenem/EDTA and imipenem strip were used for phenotypic detection of MBL production; and real-time polymerase chain reaction (PCR) for genetic detection. Genetic similarity was determined by rep-PCR. We obtained 136/161 (84.5%) isolates with positive phenotypic result for metallo-β-lactamase (MBL) and the blaSPM-1 gene was identified in 41 isolates. There was a predominant profile (>95% of genetic similarity) in 92.7% of isolates. This predominant profile was widely disseminated in Paraná state. SPM-1 is the main MBL identified in carbapenem-resistant P. aeruginosa in Southern Brazil. The genetic similarity among some isolates suggests a clonal expansion. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Carbapenem nonsusceptibility with modifiedOprDin clinical isolates ofPseudomonas aeruginosafrom India. (United States)

    Choudhury, Debarati; Talukdar, Anupam Das; Choudhury, Manabendra Dutta; Maurya, Anand Prakash; Chanda, Debadatta Dhar; Chakravorty, Atanu; Bhattacharjee, Amitabha


    This study was undertaken to investigate OprD porin-mediated carbapenem nonsusceptibility in clinical isolates of Pseudomonas aeruginosa from a tertiary referral hospital of Northeast India. A total of 267 nonduplicate, consecutive clinical isolates of P. aeruginosa were obtained. Mutation and expression levels of OprD gene were determined in carbapenem-nonsusceptible carbapenemase-nonproducing isolates. Among 19 carbapenem-nonsusceptible carbapenemase-nonproducing isolates, 11 of them demonstrated variable band pattern while performing denaturing gradient gel electrophoresis with amplified products of OprD gene. Sequencing of variable band products revealed three mutation patterns in three isolates. Relevant decrease in expression of OprD gene could also be observed in them. All the three isolates exhibited a higher minimum inhibitory concentration for imipenem (64-128 μg/mL) compared to meropenem (16-64 μg/mL). Inactivating mutation and decreased expression of OprD contribute mainly to imipenem resistance as well as to meropenem.

  8. Carbapenem nonsusceptibility with modified OprD in clinical isolates of Pseudomonas aeruginosa from India

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    Debarati Choudhury


    Full Text Available This study was undertaken to investigate OprD porin-mediated carbapenem nonsusceptibility in clinical isolates of Pseudomonas aeruginosa from a tertiary referral hospital of Northeast India. A total of 267 nonduplicate, consecutive clinical isolates of P. aeruginosa were obtained. Mutation and expression levels of OprD gene were determined in carbapenem-nonsusceptible carbapenemase-nonproducing isolates. Among 19 carbapenem-nonsusceptible carbapenemase-nonproducing isolates, 11 of them demonstrated variable band pattern while performing denaturing gradient gel electrophoresis with amplified products of OprD gene. Sequencing of variable band products revealed three mutation patterns in three isolates. Relevant decrease in expression of OprD gene could also be observed in them. All the three isolates exhibited a higher minimum inhibitory concentration for imipenem (64–128 μg/mL compared to meropenem (16–64 μg/mL. Inactivating mutation and decreased expression of OprD contribute mainly to imipenem resistance as well as to meropenem.

  9. The Role of the β5-α11 Loop in the Active-Site Dynamics of Acylated Penicillin-Binding Protein A from Mycobacterium tuberculosis

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    Fedarovich, Alena; Nicholas, Robert A.; Davies, Christopher [MUSC; (UNC)


    Penicillin-binding protein A (PBPA) is a class B penicillin-binding protein that is important for cell division in Mycobacterium tuberculosis. We have determined a second crystal structure of PBPA in apo form and compared it with an earlier structure of apoenzyme. Significant structural differences in the active site region are apparent, including increased ordering of a β-hairpin loop and a shift of the SxN active site motif such that it now occupies a position that appears catalytically competent. Using two assays, including one that uses the intrinsic fluorescence of a tryptophan residue, we have also measured the second-order acylation rate constants for the antibiotics imipenem, penicillin G, and ceftriaxone. Of these, imipenem, which has demonstrable anti-tubercular activity, shows the highest acylation efficiency. Crystal structures of PBPA in complex with the same antibiotics were also determined, and all show conformational differences in the β5–α11 loop near the active site, but these differ for each β-lactam and also for each of the two molecules in the crystallographic asymmetric unit. Overall, these data reveal the β5–α11 loop of PBPA as a flexible region that appears important for acylation and provide further evidence that penicillin-binding proteins in apo form can occupy different conformational states.

  10. Prevalence of Post-operative Wound Infections in Rural area of Latur District

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    Vikram Rajput


    Full Text Available Background: Surgical site infection (SSI continues to be a major source of morbidity following operative procedures. The modern surgeon cannot escape the responsibility of dealing with infections, having the knowledge for the appropriate use of aseptic and antiseptic technique, proper use of prophylactic and therapeutic antibiotics, and adequate monitoring and support with novel surgical and pharmacologic as well as nonpharmacologic aids. Objective: To study the most common organisms encountered in postoperative wound infections and to find out the most effective Antibiotics in case of Post Operative Wound Infections. Methodology: It is an Observational study done on 50 operated cases of post operative wounds. Results: Most common microorganism encountered in present series was E. coli in 13 cases (26%. Least common micro organism was Proteus (2%. E. coli was also encountered in mixed culture with Kleibsiella, Pseudomonas and Citrobacter. Most effective antibiotic in present series was Imipenem. Other common effective antibiotics were Amikacin, Netillin, Piperacillin, Tetracycline and Gentamycin. Least effective antibiotics were Penicillin, Cefotaxime, Cefuroxime and Cefoxitin. Conclusion: E. coli was the most common organism cultured. Imipenem and Amikacin were the most effective antibiotics.

  11. Multi-drug resistant Pseudomonas aeruginosa keratitis and its effective treatment with topical colistimethate

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    Samrat Chatterjee


    Full Text Available The purpose was to evaluate the clinical outcome in multi-drug resistant Pseudomonas aeruginosa (MDR-PA bacterial keratitis and report the successful use of an alternative antibiotic, topical colistimethate in some of them. The medical records of 12 culture-proven MDR-PA keratitis patients, all exhibiting in vitro resistance by Kirby–Bauer disc diffusion method to ≥ three classes of routinely used topical antibiotics were reviewed. Eight patients were treated with 0.3% ciprofloxacin or ofloxacin, 1 patient with 5% imipenem/cilastatin and 3 patients with 1.6% colistimethate. The outcomes in 8 eyes treated with only fluoroquinolones were evisceration in 4 eyes, therapeutic corneal graft in 1 eye, phthisis bulbi in 1 eye, and no improvement in 2 eyes. The eye treated with imipenem/cilastin required a therapeutic corneal graft. All the three eyes treated with 1.6% colistimethate healed. Colistimethate may prove to be an effective alternative antibiotic in the treatment of MDR-PA keratitis.

  12. Determination of the safety and efficacy of therapeutic neutralization of tumor necrosis factor-α (TNF-α) using AZD9773, an anti-TNF-α immune Fab, in murine CLP sepsis. (United States)

    Newham, Peter; Ross, Daniel; Ceuppens, Peter; Das, Shampa; Yates, James W T; Betts, Catherine; Reens, Jaimini; Randall, Kevin J; Knight, Richard; McKay, Jennifer S


    TNF-α neutralization is associated with increased mortality in mouse cecal ligation puncture (CLP) models. AZD9773 is an ovine polyclonal human TNF-α immune Fab, with pharmacological properties that differ from previously studied anti-TNF-α agents. We explored the safety and efficacy of therapeutically administered AZD9773 in mouse CLP sepsis. A moderate/severe-grade CLP model resulting in 20-30 % 5-day survival and a mild-grade CLP model resulting in ~70 % 5-day survival were established in human TNF-α transgene/murine TNF null (Tg1278/-/-) mice. Mice received saline resuscitation and imipenem administration every 12 h (0-72 h post-CLP). AZD9773 (or DigiFab control) was dosed 24, 36, 48 and 60 h post-CLP. Therapeutic dosing of AZD9773 in moderate/severe-grade CLP resulted in significantly increased survival (>70 %) compared with DigiFab (27 %, P CLP did not significantly affect survival outcome compared with DigiFab or imipenem alone (~60-70 % survival). These data demonstrate that TNF-α neutralization can improve survival in moderate/severe CLP sepsis. TNF-α suppression in mild-grade models was not associated with survival benefit and did not increase 5-day mortality. These findings suggest that therapeutic benefit following TNF-α attenuation in models of sepsis may depend on model severity.

  13. Thoracic empyema caused by Prevotella spp. diagnosed using 16S rDNA sequence analysis. (United States)

    Zhou, Hua; Shen, Yihong; Shen, Qian; Zhou, Jianying


    We describe a case of thoracic empyema in a 76-year-old male with complication of diabetes mellitus and hypertension. His chief complaints were fever and chest pain. The patient was diagnosed as pleural infection according to the pulmonary computed tomography (CT) scan and laboratory results. The patient had persistent fever after the treatment of continuous percutaneous drainage and 1 week of intravenous moxifloxacin. He was then misdiagnosed as tuberculous pleuritis and still had fever after the treatment of 2 weeks' antituberculosis drugs. Repeated cultures of sputum, blood, bronchoalveolar lavage fluid and pleural fluid were all negative. A gram-negative bacillus was found in the pleural pus Gram stain, and it was identified as Prevotella spp. by 16S ribosomal DNA (rDNA) sequence analysis. The patient recovered after further treatment, including CT-induced pleural drain and intravenous imipenem. Totally, he received 2-week imipenem and 1-month metronidazole therapy from the day he was diagnosed with empyema to the termination of treatment. On the subsequent 2-month and 6-month follow-up visits, no recurrence has been reported for this patient. Routine microbiological methods are important in diagnosis of pleural infection, but they have limitations in some cases, especially for anaerobe. Molecular assay based on 16S rDNA is helpful in detecting causative organisms of thoracic empyema. © 2014 John Wiley & Sons Ltd.

  14. Antibiotic susceptibility profile of bacilli isolated from the skin of healthy humans

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    Prashant Tarale


    Full Text Available Abstract In the present work, twelve bacilli were isolated from four different regions of human skin from Bela population of Nagpur district, India. The isolated bacilli were identified by their morphological, cultural and biochemical characteristics. Seven isolates were Gram negative rods, out of which five were belong to genus Pseudomonas. Three among the five Gram positive isolates were identified as Dermabactor and the remaining two Bacillus. Their antimicrobial susceptibility profile was determined by Kirby-Bauer disc diffusion method. The isolates showed resistance to several currently used broad-spectrum antibiotics. The Dermabactor genus was resistant to vancomycin, although it was earlier reported to be susceptible. Imipenem was found to be the most effective antibiotic for Pseudomonas while nalidixic acid, ampicillin and tetracycline were ineffective. Isolates of Bacillus displayed resistance to the extended spectrum antibiotics cephalosporin and ceftazidime. Imipenem, carbenicillin and ticarcillin were found to be the most effective antibiotics as all the investigated isolates were susceptible to them. Antibiotic resistance may be due to the overuse or misuse of antibiotics during the treatment, or following constant exposure to antibiotic-containing cosmetic formulations.

  15. Resistenza ai fluorochinoloni in Escherichia coli isolati da infezioni delle vie urinarie (IVU in pazienti ospedalizzati in unità di terapia intensiva (UTI.

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    Paola Pistarà


    Full Text Available Background: Fluoroquinolones are an important class of antibiotics for the treatment of urinary tract infections that have axcellent activity against Escherichia coli, one of the most frequently encountered pathogens. Several European studies have reported an increase of resistance to quinolones among uropathogenic E. coli. We conducted this study to update our knowledge on this evolution. Materials and methods: We evaluated the resistance phenotype of 203 clinical strains of E. coli collected from urine specimens. The following antimicrobial agents were tested: ampicillin, amoxiciclin-clavulanate, piperacillintazobactam, cefamandole, cefotaxime, ceftazidime, cefepime, aztreonam, imipenem, trimethoprimsulfamethoxazole, gentamicin, amikacin, ciprofloxacin, pipemidic acid, norfloxacin, nitrofurantoin. Disk diffusion tests were carried out as suggested by the CLSI (2006; strains were assigned to the susceptibility categories (susceptible, intermediate and resistant interpreting results according to the established breakpoints. Results: Resistance to quinolones (pipemidic acid, norfloxacin and ciprofloxacin was about of 45% and resistance to ampicillin, trimethoprim-sulfamethoxazole was 57. 1% and 55. 2%, respectively. Resistance rates less than 5% was found for cefepime, amikacin and imipenem. Conclusions: This study confirms the evolution through resistance to quinolones of uropathogenic E. coli isolates. The selective pressure exerted by fluoroquinolones may influence this evolution. Therapeutic alternatives, surveillance, and restriction of fluoroquinolones use are needed to control this spread of resistance.

  16. Prevalence of antimicrobial resistance among clinical isolates of Bacteroides fragilis group in Canada in 2010-2011: CANWARD surveillance study. (United States)

    Karlowsky, James A; Walkty, Andrew J; Adam, Heather J; Baxter, Melanie R; Hoban, Daryl J; Zhanel, George G


    Clinical isolates of the Bacteroides fragilis group (n = 387) were collected from patients attending nine Canadian hospitals in 2010-2011 and tested for susceptibility to 10 antimicrobial agents using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. B. fragilis (59.9%), Bacteroides ovatus (16.3%), and Bacteroides thetaiotaomicron (12.7%) accounted for ~90% of isolates collected. Overall rates of percent susceptibility were as follows: 99.7%, metronidazole; 99.5%, piperacillin-tazobactam; 99.2%, imipenem; 97.7%, ertapenem; 92.0%, doripenem; 87.3%, amoxicillin-clavulanate; 80.9%, tigecycline; 65.9%, cefoxitin; 55.6%, moxifloxacin; and 52.2%, clindamycin. Percent susceptibility to cefoxitin, clindamycin, and moxifloxacin was lowest for B. thetaiotaomicron (n = 49, 24.5%), Parabacteroides distasonis/P. merdae (n = 11, 9.1%), and B. ovatus (n = 63, 31.8%), respectively. One isolate (B. thetaiotaomicron) was resistant to metronidazole, and two isolates (both B. fragilis) were resistant to both piperacillin-tazobactam and imipenem. Since the last published surveillance study describing Canadian isolates of B. fragilis group almost 20 years ago (A.-M. Bourgault et al., Antimicrob. Agents Chemother. 36:343-347, 1992), rates of resistance have increased for amoxicillin-clavulanate, from 0.8% (1992) to 6.2% (2010-2011), and for clindamycin, from 9% (1992) to 34.1% (2010-2011).

  17. A case of intractable infectious keratitis and subsequent flap necrosis after laser in situ keratomileusis

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    Kazutaka Kamiya


    Full Text Available Kazutaka Kamiya, Masayuki Kasahara, Kimiya ShimizuDepartment of Ophthalmology, University of Kitasato School of Medicine, JapanAbstract: We report on a patient in whom intractable infectious keratitis and subsequent lamellar flap necrosis necessitating flap amputation after laser in situ keratomileusis (LASIK. A 34-year-old woman undergoing LASIK complained of blurred vision and pain in the left eye. The best spectacle-corrected visual acuity was 0.01, and slit-lamp examination showed a marked presence of stromal infiltrates involving the flap and the underlying stroma in that eye. The patient was treated topically with hourly instillation of micronomicin, levofloxacin, and cefmenoxime, together with systemic administration of imipenem, but the left eye developed corneal flap necrosis. We performed surgical debridement of the diseased stroma and excised the lamellar flap. Since nontuberculous mycobacterium was detected on the surgical instruments, we then added oral clarithromycin, and substituted systemic administration of amikacin with that of imipenem. At one month after the flap removal, the visual acuity gradually improved to 0.7, but the stromal opacity of the central cornea and hyperopic shift of +3.0 diopters remained. LASIK can cause intractable keratitis, resulting in significant visual disturbance that presumably results from insufficient antisepsis of the medical instruments used for this surgery, supporting the importance of strict sterilization of these instruments.Keywords: infectious keratitis, flap necrosis, nontuberculous mycobacterium, sterilization, LASIK

  18. Changes in gram negative microorganisms’ resistance pattern during 4 years period in a referral teaching hospital; a surveillance study

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    Khalili Hossein


    Full Text Available Abstract Background and purpose Surveillance studies evaluating antimicrobial susceptibilities are of great value in preventing the spread of resistant pathogens by elucidating the trend of resistance in commonly used antibiotics and as a consequence providing information for prescribing the most appropriate agent. This study is a longitudinal antimicrobial resistance surveillance study designed to evaluate the trend in antimicrobial resistance to gram negative microorganisms from 2007 to 2010. Method During a four-year period (2007–2010 isolates derived from all patients admitted to infectious diseases ward of Imam Khomeini Hospital, the major referral center for infectious disease in Iran with the highest admission rates, were evaluated. Based on disk diffusion method and zone of inhibition size, the microorganism was regarded as to be sensitive, resistant or has intermediate susceptibility to the antimicrobial agents. Results The widest spread Gram-negative microorganism in all of isolates taken together in our study was E.coli (30% followed by Stenotrophomonas maltophilia in 28.6% and Enterobacter spp. in 11.9%, respectively. The susceptibility to amikacin, imipenem, piperacillin/tazobactam, and nitrofurantoin was equal or above 50% for all microorganisms over four years. However, the susceptibility to ampicillin, ampicillin/sulbactam, cefotaxim, and ceftriaxone was less than 50% in derived isolates during the study period. Conclusion In conclusion, the finding of the present study revealed that resistance rate to common antimicrobial agents in Iran is growing and isolates were susceptible mostly to broad-spectrum antibiotics including imipenem and piperacillin/tazobactam.

  19. Studying the Relationship between the Ability of Biofilm Formation and Antibiotic Resistance in Acinetobacter baumannii Clinical and Environmental Isolates in Tehran, 2015

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    Faegheh Teymori


    Full Text Available Abstract Background: Acinetobacters are aerobic gram-negative bacteria which are distributed widespread in soil and water. The bacteria are isolated from cultured skin, mucous membranes, secretions and hospital environment. Acinetobacter baumannii, is a strain that more frequently isolated. Acinetobacter strains are often resistant against antimicrobial agents. Materials and Methods: The method of this study was based on field, observation and test. On August and October 2015, samples were isolated from the soil and water of the Sadeghieh Square river in Tehran, respectively, and were transferred to the laboratory in the ice pack. 50 baumannii samples were isolated by biochemical methods (TSI, SIM, OF and gram test. November 1394, 100 clinical samples were isolated from Imam Khomeini hospital by biochemical method, and in the culture media Mueller Hinton agar plates were transferred to the laboratory. Antibiogram test for 150 baumannii samples was performed. Biofilms formation of Acinetobacter baumannii environmental and clinical samples was investigated by Congo red agar and culture plate methods. Results: In all samples (clinical and soil, most of antibiotic resistance was 92% for imipenem and the resistance of water samples to imipenem was 99.9%. Biofilm formation by Congo red agar in water, soil, and clinical samles was resprctively 44%, 40% and 1%. All isolates were negative biofilm culture plate. Conclusion: Considering Acinetobacter baumannii resistance to antibiotics and the lack of biofilm formation of in clinical and environmental isolates, it was concluded that there wasn’t any relationship between antibiotic resistance and biofilm formation.

  20. Ertapenem disk performance to predict Klebsiella pneumoniae carbapenemase produced by Gram-negative bacilli isolated in a São Paulo city public hospital. (United States)

    Almeida, Lais Pinto de; Carvalho, Fabiana Puerro de; Marques, Alexandre Gimenes; Pereira, Andrea dos Santos; Bortoleto, Renata Puzzo; Martino, Marinês Dalla Valle


    To evaluate ertapenem disk performance to predict Klebsiella pneumonie carbapenemase production by Gram-negative bacilli. All Gram-negative bacilli isolated between January 2010 and June 2011 were tested by disk diffusion (Oxoid™) for sensitivity to ertapenem, meropenem and imipenem. Resistant or intermediate sensitivity strains (diameter < 22 mm for ertapenem) were also tested for the blaKPC gene by polymerase chain reaction. Disk predictive positive value for Klebsiella pneumoniae carbapenemase and specificity were calculated. Out of the 21839 cultures performed, 3010 (13.78%) were positive, and Gram-negative bacilli were isolated in 708 (23.52%) of them. Zone of inhibition diameter for ertapenem disk was < 22 mm for 111 isolates, representing 15.7% of all Gram-negative isolates. The PCR assay for blaKPC detected 40 Klebsiella pneumoniae carbapenemase-producing strains. No strains intermediate or resistant to meropenem and imipenem were sensitive to ertapenem. The ertapenem disk presented a positive predictive value of 36% to predict blaKPC and 89% specificity. The resistance of Gram-negative bacilli detected by disk diffusion against ertapenem does not predict Klebsiella pneumoniae carbapenemase production. Other mechanisms, such as production of other betalactamases and porin loss, may be implicated. The need to confirm the presence of the blaKPC is suggested. Therefore, ertapenem was a weak predictor for discriminating strains that produce Klebsiella pneumoniae carbapenemase.

  1. Antimicrobial resistance in Pseudomonas sp. causing infections in trauma patients: A 6 year experience from a south asian country

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    Nonika Rajkumari


    Full Text Available Drug resistance to Pseudomonas sp. has spread to such a level irrespective of the type of patients, that its pattern of distribution and antibiotic resistance needs to be studied in detail, especially in trauma patients and hence the study. A 6 year study was carried out among trauma patients to see the trend and type of resistance prevalent in the apex hospital for trauma care in India among nonduplicate isolates where multidrug-resistance (MDR, cross-resistance and pan-drug resistance in Pseudomonas sp. were analyzed. Of the total 2,269 isolates obtained, the species, which was maximally isolated was Pseudomonas aeruginosa (2,224, 98%. The highest level of resistance was seen in tetracycline (2,166, 95.5%, P < 0.001 and chloramphenicol (2,160, 95.2%, P < 0.001 and least in meropenem (1,739, 76.7%, P < 0.003. Of the total, 1,692 (74.6% isolates were MDR in which P. aeruginosa (75% were maximum. MDR Pseudomonas is slowing increasing since the beginning of the study period. Of 1,797 imipenem-resistant P. aeruginosa isolated during the study period, 1,763 (98% showed resistance to ciprofloxacin or levofloxacin, suggesting that cross-resistance may have developed for imipenem due to prior use of fluoroquinolones. Antibiotic resistance in Pseudomonas sp. is fast becoming a problem in trauma patients, especially in those who requires prolong hospital stay, which calls for proper antimicrobial stewardship.

  2. Resistenza ai principali antibiotici dei microrganismi isolati presso l’ospedale “Luigi Sacco” di Milano nel periodo 1997-2001

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    Giampietro Nardi


    Full Text Available Antibiotic resistance of commonly isolated bacterial species at “L. Sacco” Hospital of Milan (Italy is evaluated in the period 1997-2001. Staphylococcus aureus and Staphylococcus epidermidis are quite completely resistant to penicillin, while the agents with β-lactamase inhibitors are more active against Staphylococcus aureus than against Staphylococcus epidermidis. Also cephalotin and eritromycine are more active against Staphylococcus aureus than against Staphylococcus epidermidis. Cephalosporins are active against beta-haemolytic streptococci, while Streptococcus pyogenes shows a resistance of 25-30% against erytromicin. For Streptococcus pneumoniae there is a sporadic, not increasing, resistance to penicillin. Enterococcus faecalis shows an increasing resistance for the year 2001 against cotrimoxazole, but ampicillin and imipenem are always active against this species. Aztreonam is always active against Escherichia coli, while there is resistance to piperacillin (20-25% and ampicillin (35-45%. Resistance to cephalotin is increasing in time, while cefotaxime is always active. For Haemophilus influenzae there is a certain resistance to ampicillin (10-20%. Pseudomonas aeruginosa is often resistant to widespectrum penicillins and to imipenem and ciprofloxacin (30%. With the only exclusion of a great increase of resistance of Enterococcus faecalis to cotrimoxazole in the year 2001, all the other patterns of resistance appear to be comparable in each of the five years considered. Substantially we do not observe an increase of antibiotic resistance.

  3. Cutaneous manifestations of Nocardia brasiliensis infection in Taiwan during 2002-2012-clinical studies and molecular typing of pathogen by gyrB and 16S gene sequencing. (United States)

    Chen, Kuo-Wei; Lu, Chun-Wei; Huang, Ting-Chi; Lu, Chin-Fang; Liau, Yea-Ling; Lin, Jeng-Fong; Li, Shu-Ying


    To observe the clinicopathologic and resistance profiles of the Nocardia brasiliensis causing cutaneous nocardiosis in Taiwan, 12 N. brasiliensis isolates were prospectively collected from patients with cutaneous nocardiosis in a hospital during 2002-2012. Clinicopathologic data were obtained, and isolates were identified by biochemical methods and 16S rRNA sequencing. Susceptibilities to 14 antimicrobial compounds were tested. Isolates were further genotyped by sequencing of 16S rRNA, secA1, hsp65, and gyrB genes. The nodulopustular pyoderma associated with sporotrichoid spreading was the most common skin presentations caused by N. brasiliensis. All of the isolates were susceptible to amikacin, gentamicin, tobramycin, piperacillin/tazobactam, and trimethoprim/sulfamethoxazole and resistant to kanamycin, erythromycin, and oxacillin, while susceptibilities to imipenem, vancomycin, penicillin-G, tetracycline, clindamycin, and ciprofloxacin varied among the 12 isolates. GyrB genotyping delineated the 12 isolates into 2 major groups, which was coincident with different single nucleotide substitutions at position 160 (G versus T) of 16S rRNA, different levels of imipenem minimum inhibition concentration (4-32 versus 0.25-0.75 mg/L), and prevalence of lymphadenitis (66.7 versus 16.7%). We have noted that tiny pustular lesions can be the first sign of cutaneous nocardiosis, which we believe has not been previously emphasized. No resistance to trimethoprim and sulfamethoxazole was found; therefore, sulphonamide drugs remain effective for treatment of cutaneous nocardiosis in Taiwan. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Susceptibility profiles of Nocardia isolates based on current taxonomy. (United States)

    Schlaberg, Robert; Fisher, Mark A; Hanson, Kimberley E


    The genus Nocardia has undergone rapid taxonomic expansion in recent years, and an increasing number of species are recognized as human pathogens. Many established species have predictable antimicrobial susceptibility profiles, but sufficient information is often not available for recently described organisms. Additionally, the effectiveness of sulfonamides as first-line drugs for Nocardia has recently been questioned. This led us to review antimicrobial susceptibility patterns for a large number of molecularly identified clinical isolates. Susceptibility results were available for 1,299 isolates representing 39 different species or complexes, including 11 that were newly described, during a 6-year study period. All tested isolates were susceptible to linezolid. Resistance to trimethoprim-sulfamethoxazole (TMP-SMX) was rare (2%) except among Nocardia pseudobrasiliensis (31%) strains and strains of the N. transvalensis complex (19%). Imipenem susceptibility varied for N. cyriacigeorgica and N. farcinica, as did ceftriaxone susceptibility of the N. nova complex. Resistance to more than one of the most commonly used drugs (amikacin, ceftriaxone, TMP-SMX, and imipenem) was highest for N. pseudobrasiliensis (100%), N. transvalensis complex (83%), N. farcinica (68%), N. puris (57%), N. brasiliensis (51%), N. aobensis (50%), and N. amikacinitolerans (43%). Thus, while antimicrobial resistance can often be predicted, susceptibility testing should still be considered when combination therapy is warranted, for less well characterized species or those with variable susceptibility profiles, and for patients with TMP-SMX intolerance.

  5. Comparison between phenotypic and PCR for detection of OXA-23 type and metallo-beta-lactamases producer Acinetobacter spp.

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    Azimi, Leila


    Full Text Available [english] Background: Resistance to carbapenems is developing around the world and can cause many problems for treatment of patients. Production of metallo-beta-lactamase (MBL is one of the main mechanism for this type of resistance. So, detection of MBL-producer microorganisms can prevent the spread of this type of resistance.Materials and methods: In this study 94 spp. were investigated. Resistance to imipenem was conducted after purification and identification. Combination disc (CD and Double Disc Synergy Test (DDST were performed for phenotypic detection of MBL and the molecular PCR method was done for vim-1, vim-2, imp-1 and OXA-23 genes.Results: According to TSI, SIM and oxidation-fermentation (OF test and PCR assay 93 and one strain were identified. 85% of them were resistant to imipenem. 34% of them have a positive combination disc test (CD while Double Disc Synergy Test (DDST was negative for all of them. The vim-1, vim-2 and imp-1 genes were not detected in PCR molecular method, however in 74% of strains with positive results in combination disc, were positive for the OXA-23 gene after PCR test. This study shows that the blaOXA-23 resistance determinant may become an emerging therapeutic problem.Discussion: According to the results, it seems that combination disc does not have enough specificity for detection of MBL-producer and using Double Disc Synergy Test (DDST can be more convenient.

  6. The frequency of resistance to antibiotics of most frequently isolated bacteria from blood cultures during the period 1997-2002

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    Mirović Veljko


    Full Text Available The aim of this study was to determine the frequency of resistance to antibiotics of the most frequently isolated bacteria from blood cultures of hospitalized patients during the period 1997-2002. The resistance to antibiotics was determined by disk diffusion method according to National Committee for Clinical Laboratory Standards procedures. The majority of staphylococci isolates were resistant to methicillin, and the proportion of methicillin-resistant Staphylococcus aureus was stable (76.8-81.6%, during the follow-up period. None of the staphylococci isolates were resistant to vancomycin, but there was a very high incidence of high-level resistance of enterococci to aminoglycosides (47.2-72.2%. In 1998, only one strain among enterococci was resistant to vancomycin (Enterococcus faecium, VanA fenotype. Enterococcus spp isolates expressed variable frequency of resistance to ampicillin (15-40.1% during the follow-up period. Among Enterobacteriaceae there were no isolates resistant to imipenem, but dramatic increase of the resistance to ceftriaxone was found from 35.9% in 1997 to 95.9% in 2002 (p<0.001. Extended spectrum beta-lactamases production was found in all the species of enterobacteria isolates. Resistance to imipenem was observed in Acinetobacter spp isolates in 2002 for the first time. Pseudomonas spp isolates expressed high and very variable resistance to all antibiotics tested during the follow-up period.

  7. Prevalence and bacterial susceptibility of hospital acquired urinary tract infection

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    Dias Neto José Anastácio


    Full Text Available PURPOSE: Urinary tract infection is the most common nosocomially acquired infection. It is important to know the etiology and antibiotic susceptibility infectious agents to guide the initial empirical treatment. OBJECTIVE: To determine the prevalence of bacterial strains and their antibiotic susceptibility in nosocomially acquired urinary tract infection in a university hospital between January and June 2003. METHODS: We analyzed the data of 188 patients with positive urine culture (= 10(5 colony-forming units/mL following a period of 48 hours after admission. RESULTS: Half of patients were male. Mean age was 50.26 ± 22.7 (SD, range 3 months to 88 years. Gram-negative bacteria were the agent in approximately 80% of cases. The most common pathogens were E. coli (26%, Klebsiella sp. (15%, P. aeruginosa (15% and Enterococcus sp. (11%. The overall bacteria susceptibility showed that the pathogens were more sensible to imipenem (83%, second or third generation cephalosporin and aminoglycosides; and were highly resistant to ampicillin (27% and cefalothin (30%. It is important to note the low susceptibility to ciprofloxacin (42% and norfloxacin (43%. CONCLUSION: This study suggests that if one can not wait the results of urine culture, the best choices to begin empiric treatment are imipenem, second or third generation cephalosporin and aminoglycosides. Cefalothin and ampicillin are quite ineffective to treat these infections.

  8. Pulmonary infection with Nocardia species: a report of 10 cases and review. (United States)

    Menéndez, R; Cordero, P J; Santos, M; Gobernado, M; Marco, V


    Pulmonary nocardiosis (PN) is an infrequent and severe infection due to Nocardia spp., microorganisms that may behave both as opportunists and as primary pathogens. The aim of this study and review was to evaluate the clinical features, evolution and prognostic factors of PN. The study group comprised 10 consecutive patients with pulmonary nocardiosis acquired in a community setting, diagnosed and followed in a tertiary teaching hospital. Chronic obstructive pulmonary disease (COPD), neoplastic disease and human immunodeficiency virus (HIV) infection were the most frequent predisposing factors. Four patients were receiving corticosteroid treatment. Clinical course was chronic and diagnosis was delayed 3 weeks or more in seven of the patients. Lobar or multilobar condensation was the most frequent radiographic pattern. Antimicrobial susceptibility testing showed: 100% sensitivity for amikacin; 83% for imipenem; 71% for cefotaxime; and 71% for trimethoprim-sulphamethoxazole. The disease remained localized in the lung in five cases, with a trend toward chronicity in one with bronchiectasis. In the other five, the disease disseminated, affecting subcutaneous tissue, the central nervous system and the kidney. Three patients died, one with disseminated disease and two who were receiving corticosteroid therapy. The following conclusions were reached: 1) pulmonary nocardiosis is difficult to diagnose, diagnosis is frequently delayed and a high level of suspicion is, thus, required in patients with underlying diseases or chronic corticosteroid therapy; 2) there is frequent dissemination and high mortality; and 3) antimicrobial combinations with proven synergy, such as imipenem and amikacin, are recommended for initial therapy.

  9. Carbapenem Resistance among Enterobacter Species in a Tertiary Care Hospital in Central India

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    Atul Khajuria


    Full Text Available Objective. To detect genes encoding carbapenem resistance among Enterobacter species in a tertiary care hospital in central India. Methods. Bacterial identification of Enterobacter spp. isolates from various clinical specimens in patients admitted to intensive care units was performed by routine conventional microbial culture and biochemical tests using standard recommended techniques. Antibiotic sensitivity test was performed by standard Kirby Bauer disc diffusion technique. PCR amplification and automated sequencing was carried out. Transfer of resistance genes was determined by conjugation. Results. A total of 70/130 (53.84% isolates of Enterobacter spp. were found to exhibit reduced susceptibility to imipenem (diameter of zones of inhibition ≤13 mm by disc diffusion method. Among 70 isolates tested, 48 (68.57% isolates showed MIC values for imipenem and meropenem ranging from 32 to 64 mg/L as per CLSI breakpoints. All of these 70 isolates were found susceptible to colistin in vitro as per MIC breakpoints (<0.5 mg/L. PCR carried out on these 48 MBL (IP/IPI E-test positive isolates (12 Enterobacter aerogenes, 31 Enterobacter cloacae, and 05 Enterobacter cloacae complex was validated by sequencing for beta-lactam resistance genes and result was interpreted accordingly. Conclusion. The study showed MBL production as an important mechanism in carbapenem resistance in Enterobacter spp. and interspecies transfer of these genes through plasmids suggesting early detection by molecular methods.

  10. [Carbapenem-resistant Acinetobacter baumannii strains]. (United States)

    Bogiel, Tomasz; Kwiecińska-Piróg, Joanna; Jachna-Sawicka, Katarzyna; Gospodarek, Eugenia


    A. baumannii rods are opportunistic pathogens responsible generally for nosocomial infections. Resistance to carbapenems, observed among them, is a serious threat due to ability to be transmitted between bacterial species. The aim of our study was to evaluate the frequency of isolation and susceptibility to antibiotics of resistant to imipenem and/or meropenem A. baumannii strains isolated between 2007 and 2009 from patients of University Hospital of dr A. Jurasz Collegium Medicum of L. Rydygier in Bydgoszcz Nicolaus Copernicus University in Toruń. Study shows increasing frequency of isolation that type of strains from 4 in 2007 to 95 in 2008 and 67 in 2009. Percentage of imipenem-resistant isolates raised to 27.6% in 2008 and 31.0% in 2009. Meropenem-resistant A. baumannii isolates frequency changed from 2.1% in 2007 to 31.2% and 34.6%, in 2008 and 2009, respectively. The majority of strains were obtained from patients of the Intensive Care Units and surgery clinics. Examined A. baumannii strains were generally isolated from bronchoalveolar lavage (25.3%) and wound (18.1%) or throat (12.0%) swabs samples. The isolates demonstrated full resistance to norfloxacin, ciprofloxacin, and chloramphenicol. Ampicillin/sulbactam (24.8%), tobramycin (8.1%) and colistin (1.5%) presented the highest in vitro activity against isolated strains.

  11. Increasing antibiotic resistance among uropathogens isolated during years 2006-2009: impact on the empirical management

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    Hamid Mohammad-Jafari


    Full Text Available Urinary tract infections (UTI are one of the most common infections with an increasing resistance to antimicrobial agents. PURPOSE: Empirical initial antibiotic treatment of UTI must rely on susceptible data from local studies. MATERIALS AND METHODS: Retrospective analysis of isolated bacteria from children with UTIs was performed at the university hospital during years 2006-2009. The findings were compared with data collected in a similar study carried out in 2002- 2003. RESULTS: A total of 1439 uropathogens were isolated. Escherichia coli (E.coli was the leading cause, followed by Enterobacter, and other gram negative bacilli. It was observed resistance of E.coli to ceftriaxone, cefexime, amikacin, gentamycin, and nalidixic acid; Enterobacter to cefexime; and the resistance of gram negative bacilli to gentamicin and cefexime increased significantly. The highest effective antibiotic was Imipenem, ciprofloxacin, and amikacin with 96.7%, 95% and 91% sensitivity rates , respectively, followed by ceftriaxone 77.2%, gentamicin 77%, nitrofurantoin 76.4%, nalidixic acid 74.3% and cefexime with 70%. CONCLUSION: The use of nitrofurantoin or nalidixic acid as initial empirical antibacterial therapy for cystitis seems appropriate. For cases of simple febrile UTI, the use of initial parenteral therapies with amikacin or ceftriaxone followed by an oral third generation cephalosporin also seemed appropriated, and in cases of severely ill patients or complicated UTI, imipenem as monotherapy or, a combination of Ceftriaxone with an aminoglycoside, are recommended.

  12. Distribution of cphA or related carbapenemase-encoding genes and production of carbapenemase activity in members of the genus Aeromonas. (United States)

    Rossolini, G M; Zanchi, A; Chiesurin, A; Amicosante, G; Satta, G; Guglielmetti, P


    The prevalence of the cphA gene or related carbapenemase-encoding genes was investigated in 114 Aeromonas strains belonging to the six species of major clinical interest. A species-related distribution of cphA-related sequences was observed. Similar sequences were found in A. hydrophila, A. veronii bv. sobria, A. veronii bv. veronii, and A. jandaei, but not in A. caviae, A. trota, or A. schubertii. However, a single A. caviae strain (of 62 tested) was found carrying cphA-related sequences, suggesting the possibility of the horizontal transfer of this gene to species which normally do not carry it. Production of carbapenemase activity was detectable in 83% of the hybridization-positive strains but in none of the hybridization-negative ones. When it was present, carbapenemase activity was always inhibitable by EDTA. Either carbapenemase-producing or not, Aeromonas strains appeared to be susceptible to imipenem when in vitro susceptibility testing was performed with inocula of conventional size (10(5) CFU), for which MICs were always or = 4 micrograms/ml, being usually higher than the breakpoint for susceptibility. The present results indicate that the production of metallocarbapenemase activity, apparently encoded by cphA homologs, is widespread among some of the Aeromonas species of clinical interest (A. hydrophila, A. veronii bv. sobria, A. veronii bv. veronii, and A. jandaei) and that imipenem MICs for carbapenemase-producing strains are subjected to a relevant inoculum size effect.

  13. Molecular epidemiology and antimicrobial susceptibility of Campylobacter coli clinical isolates. (United States)

    Ruiz-Castillo, Ana; Torres-Sánchez, María José; Aznar-Martín, Javier


    Campylobacter spp. is a major cause of acute bacterial diarrhea in humans worldwide, and C. coli is responsible for 10% of the cases. A study was made of the antimicrobial susceptibility using the E-test(®), and the clonal relationship using PCR-RFLP, of the flaA gene, as well as PFGE techniques on 43 C. coli clinical isolates. Only 49% and 2% of the isolates were susceptible to erythromycin and ciprofloxacin, respectively. Imipenem and clindamyicn, with 100% and 84% of the strains, respectively, being susceptible, were the most active antimicrobials. The PCR-RFLP of flaA gene technique grouped fourteen isolates into six clusters, while the PFGE technique grouped eleven isolates into five clusters. Ciprofloxacin and erythromycin are not suitable for the treatment of C. coli infections. Clindamycin could be considered as a therapeutic alternative in cases of enteritis, while imipenem is the best alternative for extra-intestinal infections. Both PFGE and PCR-RFLP can be useful to detect clones. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  14. Theoretical approach to local infusion of antibiotics for infected pancreatic necrosis. (United States)

    González-López, Jaime; Macías-García, Fernando; Lariño-Noia, José; Domínguez-Muñoz, Juan Enrique


    Infected pancreatic necrosis is a major complications of acute pancreatitis. If drainage is required, local administration of antibiotics through transmural nasocystic or percutaneous catheter may allow increasing local antibiotic concentrations. Drug diffusion becomes the main factor influencing local drug tissue penetration. The present study aims at providing the rationale for the design of new research protocols evaluating the efficacy of local antibiotics for infected pancreatic necrosis. A review of microbiological data was performed for the most common organisms causing the infection, antibiotics spectrum and minimum inhibitory concentrations (MIC). A search of the physico-chemical properties of antibiotics was performed to calculate the diffusion coefficients. An estimation of the antibiotic concentrations in pancreatic tissue was obtained using a mathematical model. Efficacy factors (EF) were calculated and the stability of the antibiotic solutions were evaluated to optimize the dosing regimen. Piperacillin, vancomycin and metronidazole achieve high concentrations in the surrounding tissue very fast. Imipenem, ceftriaxone, ciprofloxacin, gentamicin, linezolid and cloxacillin achieve intermediate concentration values. Tigecycline, showed the lowest concentration values (diluent and 25 °C of temperature during administration. Imipenem has the best theoretical results in empiric local treatment. Linezolid and tigecycline solutions are not recommended. Copyright © 2016 IAP and EPC. Published by Elsevier B.V. All rights reserved.

  15. Evaluation of polymorphisms in pbp4 gene and genetic diversity in penicillin-resistant, ampicillin-susceptible Enterococcus faecalis from hospitals in different states in Brazil. (United States)

    Infante, Victor Hugo Pacagnelli; Conceição, Natália; de Oliveira, Adriana Gonçalves; Darini, Ana Lúcia da Costa


    The aim of the present study was to verify whether penicillin-resistant, ampicillin-susceptible Enterococcus faecalis (PRASEF) occurred in Brazil prior to the beginning of the 21st century, and to verify whether ampicillin susceptibility can predict susceptibility to other β-lactams in E. faecalis with this inconsistent phenotype. The presence of polymorphisms in the pbp4 gene and genetic diversity among the isolates were investigated. Of 21 PRASEF analyzed, 5 (23.8%) and 4 (19.0%) were imipenem and piperacillin resistant simultaneously by disk diffusion and broth dilution respectively, contradicting the current internationally accepted standards of susceptibility testing. Sequencing of pbp4 gene revealed an amino acid substitution (Asp-573→Glu) in all PRASEF isolates but not in the penicillin-susceptible, ampicillin-susceptible E. faecalis. Most PRASEF (90.5%) had related pulsed-field gel electrophoresis profiles, but were different from other PRASEF described to date. Results demonstrate that penicillin-resistant, ampicillin-susceptible phenotype was already a reality in the 1990s in E. faecalis isolates in different Brazilian states, and some of these isolates were also imipenem- and piperacillin-resistant; therefore, internationally accepted susceptibility criteria cannot be applied to these isolates. According to pbp4 gene sequencing, this study suggests that a specific amino acid substitution in pbp4 gene found in all PRASEF analyzed is associated with penicillin resistance. © FEMS 2016. All rights reserved. For permissions, please e-mail:

  16. Bisthiazolidines: A Substrate-Mimicking Scaffold as an Inhibitor of the NDM-1 Carbapenemase. (United States)

    González, Mariano M; Kosmopoulou, Magda; Mojica, Maria F; Castillo, Valerie; Hinchliffe, Philip; Pettinati, Ilaria; Brem, Jürgen; Schofield, Christopher J; Mahler, Graciela; Bonomo, Robert A; Llarrull, Leticia I; Spencer, James; Vila, Alejandro J


    Pathogenic Gram-negative bacteria resistant to almost all β-lactam antibiotics are a major public health threat. Zn(II)-dependent or metallo-β-lactamases (MBLs) produced by these bacteria inactivate most β-lactam antibiotics, including the carbapenems, which are "last line therapies" for life-threatening Gram-negative infections. NDM-1 is a carbapenemase belonging to the MBL family that is rapidly spreading worldwide. Regrettably, inhibitors of MBLs are not yet developed. Here we present the bisthiazolidine (BTZ) scaffold as a structure with some features of β-lactam substrates, which can be modified with metal-binding groups to target the MBL active site. Inspired by known interactions of MBLs with β-lactams, we designed four BTZs that behave as in vitro NDM-1 inhibitors with Ki values in the low micromolar range (from 7 ± 1 to 19 ± 3 μM). NMR spectroscopy demonstrated that they inhibit hydrolysis of imipenem in NDM-1-producing Escherichia coli. In vitro time kill cell-based assays against a variety of bacterial strains harboring blaNDM-1 including Acinetobacter baumannii show that the compounds restore the antibacterial activity of imipenem. A crystal structure of the most potent heterocycle (L-CS319) in complex with NDM-1 at 1.9 Å resolution identified both structural determinants for inhibitor binding and opportunities for further improvements in potency.

  17. First Report of NDM-1-Producing Acinetobacter guillouiae. (United States)

    Bošnjak, Zrinka; Plecko, Vanda; Budimir, Ana; Mareković, Ivana; Bedenić, Branka


    Acinetobacter spp. is an opportunistic pathogen that has demonstrated increasing relevance in nosocomial infections. Carbapenem-resistant strains have been reported worldwide. Since 2014, screening for metallo-β-lactamases (MBLs) in all Acinetobacter spp. isolates using phenotypic methods and PCR has been implemented at the University Hospital Center Zagreb. The bacterial strain was isolated from the drain of a child hospitalized in a paediatric intensive care unit and identified as Acinetobacter guillouiae using a MALDI TOF automated system. The strain was resistant to meropenem, ceftazidime, cefotaxime, ceftriaxone, cefepime, sulbactam/ampicillin, gentamicin and ciprofloxacin, intermediately susceptible to piperacillin/tazobactam and imipenem, and susceptible to amikacin and colistin. The Hodge test and combined disk test with EDTA were positive. The MICs of meropenem and imipenem were not reduced by cloxacillin, but a small reduction of two dilutions was observed following the addition of sodium chloride, which indicated that OXA-58 was produced. PCR and sequencing of chromosomal DNA from boiled colonies revealed blaOXA-58 and blaNDM-1 genes. This is the first report of NDM-1 in Acinetobacter spp. in Croatia. The early detection of these genes will aid in the prevention and in the achievement of adequate infection control by limiting the spread of these organisms. © 2015 S. Karger AG, Basel.

  18. In Vitro Activity of Sodium New Houttuyfonate Alone and in Combination with Oxacillin or Netilmicin against Methicillin-Resistant Staphylococcus aureus (United States)

    Li, Xue; Lu, Yun; Ren, Zhitao; Zhao, Longyin; Hu, Xinxin; Jiang, Jiandong; You, Xuefu


    Background Staphylococcus aureus can cause severe infections, including bacteremia and sepsis. The spread of methicillin-resistant Staphylococcus aureus (MRSA) highlights the need for novel treatment options. Sodium new houttuyfonate (SNH) is an analogue of houttuynin, the main antibacterial ingredient of Houttuynia cordata Thunb. The aim of this study was to evaluate in vitro activity of SNH and its potential for synergy with antibiotics against hospital-associated MRSA. Methodology A total of 103 MRSA clinical isolates recovered in two hospitals in Beijing were evaluated for susceptibility to SNH, oxacillin, cephalothin, meropenem, vancomycin, levofloxacin, minocycline, netilmicin, and trimethoprim/sulfamethoxazole by broth microdilution. Ten isolates were evaluated for potential for synergy between SNH and the antibiotics above by checkerboard assay. Time-kill analysis was performed in three isolates to characterize the kill kinetics of SNH alone and in combination with the antibiotics that engendered synergy in checkerboard assays. Besides, two reference strains were included in all assays. Principal Findings SNH inhibited all test strains with minimum inhibitory concentrations (MICs) ranging from 16 to 64 µg/mL in susceptibility tests, and displayed inhibition to bacterial growth in concentration-dependent manner in time-kill analysis. In synergy studies, the combinations of SNH-oxacillin, SNH-cephalothin, SNH-meropenem and SNH-netilmicin showed synergistic effects against 12 MRSA strains with median fractional inhibitory concentration (FIC) indices of 0.38, 0.38, 0.25 and 0.38 in checkerboard assays. In time-kill analysis, SNH at 1/2 MIC in combination with oxacillin at 1/128 to 1/64 MIC or netilmicin at 1/8 to 1/2 MIC decreased the viable colonies by ≥2log10 CFU/mL. Conclusions/Significance SNH demonstrated in vitro antibacterial activity against 103 hospital-associated MRSA isolates. Combinations of sub-MIC levels of SNH and oxacillin or netilmicin

  19. Hygienic sanitary conditions of sun dried meat marketed in Cruz das Almas, Bahia and detection of strains with antimicrobial resistance

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    Norma Suely Evangelista-Barreto


    Full Text Available This study aimed to evaluate the microbiological, physical and chemical qualities of sun dried meat marketed in Cruz das Almas, Bahia, as well as trace the resistance profile of the isolated strains against different commercial pharmacos. There were collected and analysed 36 samples of sun dried meat, acquired in 12 different establishment (supermarkets, mini-markets, butchers and a municipal market, and quantified mesophilic aerobic bacteria, coliforms, Staphylococcus coagulase positive, E. coli and presence of Salmonella spp., as well as specific content humidity, water activity (Aw and chloride. In 83% of the establishments, mesophilic bacteria counted > 105 CFU.g-1 and 58% coliforms at 35º C > 105 NMP.g- 1 and coliforms at 45ºC > 103 NMP.g-1. Escherichia coli was isolated in 75% of the establishments. Staphylococcus spp. ranged from 4.8 x 104 to 9.0 x 108 UFC.g-1, not being isolated Staphylococcus coagulase positive. Salmonella was found in 25% of the establishments. The humidity in the sun dried meat samples ranged from 52.37% to 74.69%, the Aw from 0.87 to 0.95 and the chloride from 3.16% to 5.98%. Salmonella was 100% resistant to tetracycline, acid nalidixic, cephalothin and erythromycin, with intermediate resistance to ampicillin and gentamicin. Escherichia coli was resistant to erythromycin (100%, ampicillin (68.7%, cephalothin (71.4%, tetracycline (64.2%, nalidixic acid (35.7% and gentamicin (12.5%. Multiresistant strains of E. coli were observed in 87.5% of the isolates, and it happened that in 28.6% of the resistance it was mediated by plasmids. Multidrug resistance profile was observed in all Salmonella, with a strain showing plasmid resistance. The marketing of sun dried meat in Cruz das Almas presents hygienic and sanitary failures due to it’s high microbial loads. This fact undermines the safety and product lifetime, and may also pose risk to public health since it markets strains with antimicrobial.

  20. Multifunctional implant coatings providing possibilities for fast antibiotics loading with subsequent slow release. (United States)

    Brohede, Ulrika; Forsgren, Johan; Roos, Stefan; Mihranyan, Albert; Engqvist, Håkan; Strømme, Maria


    The possibility to fast-load biomimetic hydroxyapatite coatings on surgical implant with the antibiotics Amoxicillin, Gentamicin sulfate, Tobramycin and Cephalothin has been investigated in order to develop a multifunctional implant device offering sustained local anti-bacterial treatment and giving the surgeon the possibility to choose which antibiotics to incorporate in the implant at the site of surgery. Physical vapor deposition was used to coat titanium surfaces with an adhesion enhancing gradient layer of titanium oxide having an amorphous oxygen poor composition at the interface and a crystalline bioactive anatase TiO(2) composition at the surface. Hydroxyapatite (HA) was biomimetically grown on the bioactive TiO(2) to serve as a combined bone in-growth promoter and drug delivery vehicle. The coating was characterized using scanning and transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The antibiotics were loaded into the HA coatings via soaking and the subsequent release and antibacterial effect were analyzed using UV spectroscopy and examination of inhibition zones in a Staphylococcus aureus containing agar. It was found that a short drug loading time of 15 min ensured antibacterial effects after 24 h for all antibiotics under study. It was further found that the release processes of Cephalothin and Amoxicillin consisted of an initial rapid drug release that varied unpredictably in amount followed by a reproducible and sustained release process with a release rate independent of the drug loading times under study. Thus, implants that have been fast-loaded with drugs could be stored for ~10 min in a simulated body fluid after loading to ensure reproducibility in the subsequent release process. Calculated release rates and measurements of drug amounts remaining in the samples after 22 h of release indicated that a therapeutically relevant dose could be achieved close to the implant surface for about 2 days. Concluding

  1. Impetigo: diagnosis and treatment. (United States)

    Hartman-Adams, Holly; Banvard, Christine; Juckett, Gregory


    Impetigo is the most common bacterial skin infection in children two to five years of age. There are two principal types: nonbullous (70% of cases) and bullous (30% of cases). Nonbullous impetigo, or impetigo contagiosa, is caused by Staphylococcus aureus or Streptococcus pyogenes, and is characterized by honey-colored crusts on the face and extremities. Impetigo primarily affects the skin or secondarily infects insect bites, eczema, or herpetic lesions. Bullous impetigo, which is caused exclusively by S. aureus, results in large, flaccid bullae and is more likely to affect intertriginous areas. Both types usually resolve within two to three weeks without scarring, and complications are rare, with the most serious being poststreptococcal glomerulonephritis. Treatment includes topical antibiotics such as mupirocin, retapamulin, and fusidic acid. Oral antibiotic therapy can be used for impetigo with large bullae or when topical therapy is impractical. Amoxicillin/clavulanate, dicloxacillin, cephalexin, clindamycin, doxycycline, minocycline, trimethoprim/sulfamethoxazole, and macrolides are options, but penicillin is not. Natural therapies such as tea tree oil; olive, garlic, and coconut oils; and Manuka honey have been anecdotally successful, but lack sufficient evidence to recommend or dismiss them as treatment options. Treatments under development include minocycline foam and Ozenoxacin, a topical quinolone. Topical disinfectants are inferior to antibiotics and should not be used. Empiric treatment considerations have changed with the increasing prevalence of antibiotic-resistant bacteria, with methicillin-resistant S. aureus, macrolide-resistant streptococcus, and mupirocin-resistant streptococcus all documented. Fusidic acid, mupirocin, and retapamulin cover methicillin-susceptible S. aureus and streptococcal infections. Clindamycin proves helpful in suspected methicillin-resistant S. aureus infections. Trimethoprim/sulfamethoxazole covers methicillin-resistant S

  2. Development of a direct ELISA based on carboxy-terminal of penicillin-binding protein BlaR for the detection of β-lactam antibiotics in foods. (United States)

    Peng, Juan; Cheng, Guyue; Huang, Lingli; Wang, Yulian; Hao, Haihong; Peng, Dapeng; Liu, Zhenli; Yuan, Zonghui


    β-Lactam antibiotics, including penicillins and cephalosporins, are commonly used in veterinary medicine. Illegal use and abuse of β-lactams could cause allergy and selected bacterial resistance. BlaR-CTD, the carboxy-terminal of penicillin-recognizing protein BlaR from Bacillus licheniformis ATCC 14580, was utilized in this study to develop a receptor-based ELISA for detection and determination of β-lactam antibiotics in milk, beef, and chicken. This assay was based on directly competitive inhibition of binding of horseradish peroxidase-labeled ampicillin to the immobilized BlaR-CTD by β-lactams. The assay was developed as screening test with the option as semiquantitative assay, when the identity of a single type of residual β-lactam was known. The IC50 values of 15 β-lactam antibiotics, including benzylpenicillin, ampicillin, amoxicillin, dicloxacillin, oxacillin, nafcillin, cefapirin, cefoperazone, cefalotin, cefazolin, cefquinome, ceftriaxone, cefotaxime, cefalexin, ceftiofur and its metabolite desfuroylceftiofur were evaluated and ranged from 0.18 to 170.81 μg L(-1). Simple sample extraction method was carried out with only phosphate-buffered saline, and the recoveries of selected β-lactam antibiotics in milk, beef, and chicken were in the range of 53.27 to 128.29 %, most ranging from 60 to 120 %. The inter-assay variability was below 30 %. Limits of detection in milk, beef, and chicken muscles with cefquinome matrix calibration were 2.10, 30.68, and 31.13 μg kg(-1), respectively. This study firstly established a rapid, simple, and accurate method for simultaneous detection of 15 β-lactams in edible tissues, among which 11 β-lactams controlled by European Union could be detected below maximum residue limits.

  3. Identifying Drug-Drug Interactions by Data Mining: A Pilot Study of Warfarin-Associated Drug Interactions. (United States)

    Hansen, Peter Wæde; Clemmensen, Line; Sehested, Thomas S G; Fosbøl, Emil Loldrup; Torp-Pedersen, Christian; Køber, Lars; Gislason, Gunnar H; Andersson, Charlotte


    Knowledge about drug-drug interactions commonly arises from preclinical trials, from adverse drug reports, or based on knowledge of mechanisms of action. Our aim was to investigate whether drug-drug interactions were discoverable without prior hypotheses using data mining. We focused on warfarin-drug interactions as the prototype. We analyzed altered prothrombin time (measured as international normalized ratio [INR]) after initiation of a novel prescription in previously INR-stable warfarin-treated patients with nonvalvular atrial fibrillation. Data sets were retrieved from clinical work. Random forest (a machine-learning method) was set up to predict altered INR levels after novel prescriptions. The most important drug groups from the analysis were further investigated using logistic regression in a new data set. Two hundred and twenty drug groups were analyzed in 61 190 novel prescriptions. We rediscovered 2 drug groups having known interactions (β-lactamase-resistant penicillins [dicloxacillin] and carboxamide derivatives) and 3 antithrombotic/anticoagulant agents (platelet aggregation inhibitors excluding heparin, direct thrombin inhibitors [dabigatran etexilate], and heparins) causing decreasing INR. Six drug groups with known interactions were rediscovered causing increasing INR (antiarrhythmics class III [amiodarone], other opioids [tramadol], glucocorticoids, triazole derivatives, and combinations of penicillins, including β-lactamase inhibitors) and two had a known interaction in a closely related drug group (oripavine derivatives [buprenorphine] and natural opium alkaloids). Antipropulsives had an unknown signal of increasing INR. We were able to identify known warfarin-drug interactions without a prior hypothesis using clinical registries. Additionally, we discovered a few potentially novel interactions. This opens up for the use of data mining to discover unknown drug-drug interactions in cardiovascular medicine. © 2016 American Heart Association

  4. Molecularly imprinted polymer beads for clean-up and preconcentration of β-lactamase-resistant penicillins in milk. (United States)

    Urraca, Javier L; Chamorro-Mendiluce, Raquel; Orellana, Guillermo; Moreno-Bondi, Maria C


    This work describes the development and application of class-selective molecularly imprinted polymers (MIPs) for the analysis of beta-lactamase-resistant penicillins, namely cloxacillin (CLOXA), oxacillin (OXA), and dicloxacillin (DICLOXA), in milk samples. Our method is based on molecularly imprinted solid-phase extraction (MISPE) coupled to high-performance liquid chromatography (HPLC) with diode-array detection (DAD). 2-Biphenylylpenicillin (2BPEN), a surrogate with a close resemblance to beta-lactamase-resistant penicillins in terms of size, shape, hydrophobicity, and functionality, was synthesized and used as the template for the polymer synthesis. A MIP library was prepared and screened to select the optimum functional monomer, N-(2-aminoethyl)methacrylamide, and cross-linker, trimethylolpropane trimethacrylate, that provided the best recognition for the target antibiotics. For the MISPE application, the MIPs were prepared in the form of microspheres, using porous silica beads (40-75 μm) as sacrificial scaffolds. The developed MISPE method enables efficient extraction from aqueous samples and analysis of the antimicrobials, when followed by a selective washing with 2 mL acetonitrile-water (20:80 v/v) and elution with 1 mL 0.05 mol L(-1) tetrabutylammonium in methanol. The analytical method was validated according to EU guideline 2002/657/EC. The limits of quantification (S/N = 10) were in the 5.3-6.3 μg kg(-1) range, well below the maximum residue limits (MRLs) currently established. Inter-day mean recoveries were in the range 99-102 % with RSDs below 9 %, improving on the performance of previously reported MISPE methods for the analysis of CLOXA, OXA, or DICLOXA in milk samples.

  5. Presentación atípica de piomiositis tropical difusa de psoas por Staphylococcus aureus meticilino resistente Atypical presentation of diffuse tropical pyomiositis of the psoas due to methicillin resistant Staphylococcus aureus

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    Ray Ticse


    Full Text Available La piomiositis tropical difusa primaria es una enfermedad de presentación infrecuente en nuestro medio, con pocos casos asociados a Staphylococcus aureus meticilino resistente, adquirido en la comunidad (MRSA-AC. Se presenta el caso de un paciente de 70 años, con tratamiento irregular para diabetes mellitus tipo 2, que fue hospitalizado por presentar un cuadro de diez días de evolución, con dolor lumbar irradiado a miembro inferior izquierdo, fiebre y flexión forzada de la cadera derecha por dolor a la movilización. El diagnóstico de piomiositis difusa de ambos psoas se realizó con resonancia magnética. Del cultivo de una colección paravertebral posterior se aisló Staphylococcus aureus resistente a oxacilina, penicilina y dicloxacilina.Diffuse tropical primary pyomyositis is an infrequent entity in our country, with few cases associated to communityacquired Methicillin- resistant Staphylococcus aureus. There are no reported cases of Community-Acquired Methicillin- Resistant Staphylococcus aureus (CA- MRSA in Peru. We present the case of a 70 year old male with a previous diagnosis of type 2 diabetes mellitus, receiving irregular treatment, who was admitted to the hospital with a history of 10 days of low back pain radiating to the left leg, fever and forced flexion of the right hip due to pain during movement. The diagnosis of diffuse pyomyositis of both psoas muscles was performed with MRI and culture of a posterior paravertebral collection, from which Staphylococcus aureus resistant to oxacillin, penicillin and dicloxacillin was isolated.

  6. An HPLC-DAD method for the simultaneous determination of nine β-lactam antibiotics in ewe milk. (United States)

    Cámara, M; Gallego-Picó, A; Garcinuño, R M; Fernández-Hernando, P; Durand-Alegría, J S; Sánchez, P J


    The presence of β-lactam residues in foodstuffs constitutes a potential risk to the human health and undesirable effects on consumers, and nowadays these antibiotic residues are also recognised as an emerging environmental problem. In addition, these are of great concern to prestigious Manchego cheese processors (Central Spain denomination of origin) because they reduce the curdling of milk and cause improper cheese ripening, which consequently lead to an important loss of monetary income. This work describes the development of a sensitive and reliable method using liquid chromatography with UV-diode array detection (LC-DAD) for simultaneous determination of the β-lactam antibiotics, ampicillin (AMP), benzylpenicillin (PEG), cephalexin (CFX), cefazolin (CFL), cefoperazone (CFP), cloxacillin (CLO), dicloxacillin (DCL), oxacillin (OXA) and phenoxymethylpenicillin (PEV), in Manchega ewe milk. The column, mobile phase, temperature and flow rate were optimised to provide the best resolution of these analytes. The extraction method of the antibiotic residues involves the deproteinisation of the milk sample using acetonitrile and centrifugation followed by a solid-phase extraction (SPE) clean-up. The recoveries for the studied β-lactams ranged from 79% to 96% with relative standard deviations between 0.5% and 4.9%. The limits of quantification (LOQs) for all these compounds were in the range of 3.4-8.6μgkg(-1), which are lower than the maximum residue limits (MRLs) established by the European Union for the studied β-lactams in milk, making the method suitable for performing routine analyses. The proposed multi-residue LC-UV-diode array detection (LC-DAD) method is a powerful and popular alternative for the determination and confirmation of antibiotic residues in small milk industries and is the first one capable of determining nine β-lactam antibiotics in samples of Manchega ewe milk. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Application of a liquid chromatographic procedure for the analysis of penicillin antibiotics in biological fluids and pharmaceutical formulations using sodium dodecyl sulphate/propanol mobile phases and direct injection. (United States)

    Rambla-Alegre, Maria; Martí-Centelles, Rosa; Esteve-Romero, Josep; Carda-Broch, Samuel


    A direct injection liquid chromatography procedure was developed for the simultaneous determination of four penicillin antibiotics (amoxicillin, ampicillin, cloxacillin and dicloxacillin) in pharmaceutical formulations and physiological fluids (urine) using hybrid micellar mobile phases. These antimicrobials are used to treat gastrointestinal and systemic infections. The four penicillins were analysed using a Zorbax C18 reversed-phase column and detected at 210 nm. These antibiotics were separated by an interpretive optimisation procedure based on the accurate description of the retention and shape of the chromatographic peaks. Antibiotics were eluted in less than 16 min with no interference by the urine protein band or endogenous compounds using the mobile phase 0.11 M sodium dodecyl sulphate-6% propanol-0.01 M NaH(2)PO(4) buffered at pH 3. The method was validated according to the Food and Drug Administration guideline, including analytical parameters such as linearity (R(2)>0.993), intra- and inter-day precisions (RSD, %: 0.1-4.4 and 1.2-5.9, respectively), and robustness for the four compounds. This method is sensitive enough for the routine analysis of penicillins at therapeutic urine levels, with limits of detection in the 1.5-15 ng mL(-1) range and limits of quantification of 50 ng mL(-1). Recoveries in a micellar medium and a spiked urine matrix were in the 92.4-108.2% and 96-110% ranges, respectively. Finally, the method was successfully applied to determine these antibiotics in urine samples and pharmaceutical formulations. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Screening of probiotic lactic acid bacteria from Thai fermented foods for human.

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    Kantachote, D.


    Full Text Available Total of 327 strains of lactic acid bacteria were isolated from 179 samples of various Thai fermented foods. The strains were investigated for their probiotic properties based on stability in bile salt (0.15% and high acidity (pH 2, 3 and 4. Moreover, utilization of protein or fat or starch, growth in the absence of vitamin B12 and growth under both aerobic and anaerobic conditions with no significant difference were also considered. According to the above criteria, 67 strains were selected for antibiotics sensitivity test. The selected strains were susceptible to following antibiotics: ampicillin, cephalothin, cefoperazone, tetracycline andchloramphenicol; however the strains were resistant to vancomycin, kanamycin, streptomycin, norfloxacin and polymyxin B. Using agar spot method, only 5 strains were able to inhibit 13 strains of manifest by a bacteria indicator as clear zone greater than 10 mm. A further investigation using co-culture technique showed inhibition of the tested organisms was between 80 and 100 percent. The strains grew under media of MRS and SPY2 (no materials from animal over 36 hours with no significant difference. The strains were investigated for survival in condition of high acidity within 3 hours. It was found that at pH 4 almost 100% were maintained but at pH 2 and 3 the survival reduced approximately 1 log cycle. The strain LA71 which showed the highest survival was identified as Lactobacillus plantarum.

  9. Antimicrobial Resistant Pattern of Escherichia Coli Strains Isolated from Pediatric Patients in Jordan

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    Mohammad Alshara


    Full Text Available The present study was conducted to investigate antimicrobial resistant pattern of Escherichia coli (E. coli strains isolated from clinical specimens of Jordanian pediatric patients during the period from January to December 2008. A total of 444 E. coli strains were isolated from clinical specimens and tested for their susceptibility to different antimicrobial drugs. Overall, high resistance rate was observed for ampicillin (84%, followed by amoxicillin-clavulanic acid (74.3%, cotrimoxazole (71%, nalidixic acid (47.3%, cephalothin (41%. Lower resistance rates were observed for amikacin (0% followed by Cefotaxime (11%, Ceftriaxone (11.7%, ciprofloxacin (14.5%, Norfloxacin (16.5%, gentamicin (17.3% cephalexin (20.9%, Ceftazidime (22.5%, cefixime (29.6%, and cefaclor (32.8%. Ampicillin, amoxicillin-clavulanic acid and cotrimoxazole were found to be ineffective at in vitro inhibition of the E. coli of pediatric origin. Amikacin was highly effective for E. coli with susceptibility rate of 100%. The majority of E. coli strains were susceptible to third generation cephalosporins and fluoroquinolones.

  10. Contamination rate, antibiotic susceptibility profile, biofilm formation and presence of TSST-1 gene in Staphylococcus aureus isolates

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    K. Ebrahimzadeh


    Full Text Available This study aimed to investigate the prevalence of Staphylococcus aureus in raw milk and traditional dairy products of West-Azerbaijan Province and also to evaluate the presence of TSST-1 virulence gene, antibiotic resistance and biofilm formation of the isolates. Using stratified random method, a total of 80 raw milk and traditional dairy products (including traditional cheese, cream and curd together with 20 nasal swab samples of the dairy products’ manufacturers were collected. S. aureus strains were isolated and identified by conventional culture methods. Afterwards, the isolates were subjected to PCR analysis to detect the presence of TSST-1 gene. According to the findings, 35% of the samples were contaminated by S. aureus. Moreover TSST-1 gene was recognized in 1 cheese and 2 swab samples. Antibiotic resistance profile revealed that most of S. aureus isolates were resistant towards vancomycin, penicillin, and methicillin and sensitive towards co-trimoxazole, gentamicin, rifampin, oxacillin, and cephalothin. Moreover, 2.85%, 17.15%, and 80% of the isolates were capable to form high, moderate and low amounts of biofilm. High occurrence of S. aureus in milk and dairy products which harbor TSST-1 virulence gene, and the strains that demonstrated resistant to several antibiotics and capable of biofilm formation, could be considered a health threat to the consumers of these products.

  11. Isolation and identification of Nocardia asteroids complex isolated from thigh abscess in a patient with Behçet\\\\\\'s syndrome: the first report from Iran

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    Seyyed Saeed Eshraghi


    Full Text Available Background: Nocardia species are Gram-positive, partially acid fast, non-motile, catalase positive, aerobic and saprophytic actinomycetes found all around the world. They invade the human body from the environment via trauma and respiratory tract and cause cutaneous, pulmonary and systemic diseases. They are able to grow in various media.The organisms opportunistically infect both immunocompromised and immunocompetent individuals. Behcet's disease is an autoimmune disease and immunocompromised patient which may suitable host for Nocardia bacterium. The present study is the first case report of isolation of Nocardia from the thigh abscess in a patient with behcet’s disease from Iran.Case Presentation: A 39-year-old man with Behcet’s disease in August 2011 was admitted to Shariati hospital Tehran, with swelling and pain in the left flank and left thigh. Microscopic identification from direct microbiological slide of thigh abscess discharge demonstrated number of lymphocytes, neutrophils and macrophages foamy and white blood cells together with filamentous bacteria. Further microbiological characterization using phenotypic and antibiogram tests with disk diffusion method, demonstrated that the isolated bacterium is Nocardia asteroides complex. The bacteria were sensitive to ampicillin, vancomycin, ceftriaxone, amikacin and cotrimoxazole but it was resistant to clindamycin, erythromycin, penicillin G, cephalothin and gentamicin. The patient was treated with cotrimoxazole.Conclusion: Because of the high incidence and high mortality of Nocardia infection in immunocompromised cases, rapid detection and timely treatment for these patients is necessary.

  12. Survey of Minas frescal cheese from Southwest Minas Gerais for virulence factors and antimicrobial resistance in Escherichia coli isolates

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    Mõnica Hitomi Okura


    Full Text Available The soft cheese Minas frescal is one of the most popular cheese in Brazil, which is typically manufactured in small dairy farms under unsatisfactory hygiene conditions. To assess the risk involved in consumption of this cheese, virulence markers were investigated in 330 Escherichia coli strains isolated from 30 Minas frescal cheeses inspected by official government agency (SIF - serviço de inspeção federal, from 50 cheeses not inspected by SIF and 31 cheeses not inspected by SIF with spice added, all of them collected in the southwest of Minas Gerais State. The E. coli isolates were screened for the presence of Shiga toxin-encoding (stx 1 and stx 2, intimin (eae genes and for the presence of (pap, sfa, afa genes related to adhesion in epithelial cells. The only gene detected by PCR was the sfa gene at one isolate. The strains were also screened for resistance to 9 antimicrobial drugs. Predominant resistance was to cephalothin, tetracycline and streptomycin. Multidrug resistance was found among isolates from cheese with SIF (16.6%, cheese without SIF (8.0% and cheese without SIF with spice added (30.0% what is a reason for concern due to the high consumption of raw milk cheese by the Brazilian population.

  13. Isolation, identification and antimicrobial resistance profile of Staphylococcus aureus in Cockroaches (Periplaneta Americana

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    Ariful Islam


    Materials and methods: A total of 150 cockroaches (P. americana were randomly captured from three households and four restaurants in Chittagong City Corporation, Bangladesh during July to December 2014. The cockroaches were transported to the bacteriology laboratory at the Poultry Research and Training Centre (PRTC, Chittagong Veterinary and Animal Sciences University. The isolation and identification of Staphylococcus spp. from the external surface wash and gut homogenates by pooling cockroaches were done by following conventional bacteriological examinations followed by biochemical characterization. The antibiotic susceptibility profiles of the isolates were determined using disc diffusion method. Results: In this study, the overall prevalence of S. aureus was 38% (n=57/150. Higher prevalence of Staphylococcus spp. was observed among the cockroaches from restaurant (49.3%; n=37/75 as compared to those of households (26.7%; n=20/75 having a significant difference (P<0.05. Highest level of resistance by the Staphylococcus spp. was found to Penicillin (68% followed by Erythromycin (60%, Oxacillin (46% and Clindamycin (31%. On the other hand, the Staphylococci isolates were highly sensitive to Cephalothin (84% and Kanamycin (65%. Conclusion: The rational use of antibiotics needs to be adopted in both human and animal medicine practices to prevent the emergence of drug resistant Staphylococcus spp. [J Adv Vet Anim Res 2016; 3(3.000: 221-228

  14. Escherichia coli isolates from sick chickens in China: changes in antimicrobial resistance between 1993 and 2013. (United States)

    Chen, Xiang; Zhang, Weiqiu; Yin, Jiajun; Zhang, Ning; Geng, Shizhong; Zhou, Xiaohui; Wang, Yanhong; Gao, Song; Jiao, Xinan


    The use of antimicrobials for the control of infectious disease has increased in recent decades. Understanding trends in antimicrobial resistance provides clues about the relationship between antimicrobial use and the emergence of resistance. We examined the resistance of 540 Escherichia coli isolates to 19 antimicrobials that represent 11 classes of antimicrobial agents. The isolates were collected from chickens between 1993 and 2013 in China. Overall, >96.7% of the isolates were resistant to at least one of the tested compounds, and 87.2% of them displayed multidrug resistance (MDR) representing five to six antimicrobial classes. A high proportion of E. coli isolates were resistant to tetracycline (90.6%), nalidixic acid (80.6%), ampicillin (77.2%), trimethoprim-sulfamethoxazole (76.9%), and streptomycin (72.8%). Only 3.0% of the isolates were resistant to nitrofurantoin, and none was resistant to meropenem. Resistance to amikacin, ampicillin, aztreonam, ceftazidime, cefotaxime, cephalothin, chloramphenicol, ciprofloxacin, fosfomycin, levofloxacin, norfloxacin, nalidixic acid, piperacillin, and trimethoprim-sulfamethoxazole significantly increased from 1993 to 2013 (P <0.01). There was an increasing trend in MDR over the 20 year period. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Antimicrobial resistance of Escherichia coli isolated in newly-hatched chickens and effect of amoxicillin treatment during their growth. (United States)

    Jiménez-Belenguer, Ana; Doménech, Eva; Villagrá, Arantxa; Fenollar, Alejandro; Ferrús, Maria Antonia


    The use of antimicrobials in food animals is the major determinant for the propagation of resistant bacteria in the animal reservoir. However, other factors may also play a part, and in particular vertical spread between the generations has been suggested to be an important transmission pathway. The objective of this paper was to determine the resistance patterns of Escherichia coli isolated from newly-hatched chickens as well as to study the antibiotic pressure effect when amoxicillin was administered during their growing period. With this aim, meconium from 22 one-day-old Ross chickens was analysed. In addition, during their growth period, amoxicillin treatments at days 7, 21 and 35 were carried out. Results showed a high number of E. coli-resistant strains were isolated from the treated one-day-old chickens, and were the highest for β-lactams group, followed by quinolone and tetracyclines. After treatment with amoxicillin, the highest percentage of resistances were detected for this antibiotic compared to the others analysed, with significant differences in resistance percentages between control and treated broilers detected in relation to ampicillin, cephalothin, streptomycin, kanamycin, gentamicin, chloramphenicol and tetracycline. Differences in resistances to ciprofloxacin and nalidixic acid between control and treated animals were not observed and there was lack of resistance for amikacin and ceftriaxone. These results suggest the possibility of vertical transmission of resistant strains to newly-hatched chicks from parent flocks, and seem to indicate that the treatment with amoxicillin increased the resistance of E. coli to other antibiotics.

  16. Etiologic study of urinary tract infection in dogs

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    Marcia Mery Kogika


    Full Text Available Urinary tract infections were documented in 51 dogs. Several factors such as etiologic agents, localization of the infection, predisposing factors, sex, age, and breed were considered. The diagnosis of urinary tract infection (UTI was based on bacteriological investigation and it was considered positive when urine sample collected by catheterization contained more than 105 bacteria/ml. Mixed infection was found in 4 of the infected dogs, totallizing 55 isolates. Among them, Escherichia coli (35.3% was the most frequently isolated, followed by Staphylococcus sp. (23.5%, Proteus mirabilis (15.7%, Streptococcus sp. (13.7%, Klebsiella sp. (9.8%. Pseudomonas aeruginosa (3.9%, Enterobacter cloacae (2.0%, Citrobacter freundii (2.0% and Providencia rettgeri (2.0%. As to antimicrobial susceptibility, norfloxacin and gentamicin were successful for the treatment of gram-negative microorganisms, while the most effective drugs for gram-positive bacteria were cephalothin and nitrofurantoin. UTI was observed more frequently in Cocker Spaniel and German Shepherd; male dogs were more involved, and pyelonephritis was the predominant disease observed. Infection was seen in all ages, but the frequency was higher in middle aged dogs. Urolithiasis were observed as common predisposing or underlying factors to UTI being, cither Staphylococcus sp. or Proteus mirabilis isolated in those cases which alkaline urine pH was observed.

  17. Prevalence and antimicrobial susceptibility of salmonellae isolates from reptiles in Taiwan. (United States)

    Chen, Chun-Yu; Chen, Wan-Ching; Chin, Shih-Chien; Lai, Yen-Hsueh; Tung, Kwong-Chung; Chiou, Chien-Shun; Hsu, Yuan-Man; Chang, Chao-Chin


    Pets, including reptiles, have been shown to be a source of Salmonella infection in humans. Due to increasing popularity and variety of exotic reptiles as pets in recent years, more human clinical cases of reptile-associated Salmonella infection have been identified. However, limited information is available with regard to serotypes in different reptiles (turtles, snakes, and lizards) and antimicrobial resistance of Salmonella in pet reptiles. The current study was thus conducted to determine the prevalence of Salmonella colonization in pet reptiles. Salmonella organisms were isolated from 30.9% of 476 reptiles investigated. The isolation prevalences were 69.7% (23/33), 62.8% (27/43), and 24.3% (97/400) in snakes, lizards, and turtles, respectively. A total of 44 different Salmonella serovars were identified. Compared with S. Heron, Bredeney, Treforest, and 4,[5],12:i:-, S. Typhimurium isolates were resistant to many antimicrobials tested, and notably 61.1% of the isolates were resistant to cephalothin. The results indicated that raising reptiles as pets could be a possible source of Salmonella infection in humans, particularly zoonotic Salmonella serovars such as S. Typhimurium that may be resistant to antimicrobials.

  18. Isolation, identification and characterization of Morganella morganii from Naja naja atra in Beijing, China. (United States)

    Wang, H-F; Du, L-Y; Luo, J; He, H-X


    Morganella morganii is an important opportunistic human pathogen and belongs to the family of Enterobacteriaceae. Although it is widely distribution, it only be considered a rare cause of human infections. We report the isolate of M. morganii from Naja naja atra following infections of heart, lung and liver. Seven strains were confirmed using 16S rDNA amplified and sequences. Antimicrobial susceptibility testing of M. morganii isolates demonstrated ubiquitous resistance to ampicillin, amoxicillin/clavulanic acid, cefazolin, cephalothin, sulfamethoxazole/trimethoprim, sulfamethoxazole et al. However, M. morganii ubiquitous susceptible to piperacillin, ampicillin/sulbactam, piperacillin/tazobactam, cefixime et al. Further investigate display gyr B and Sul2 genes presence in all M. morganii isolates. AAC(3)-II was found in E2, E3 and E6 M. morganii. gyrA and qnrB expression in M3 and M6 M. morganii. This is the first description in M. morganii carrying AAC(3)-II, gyrB, gyrA, qnrB, and Sul2 genes from Naja naja atra, which suggests the increasing risk of pathogen transmission between humans and wildlife.

  19. Identification and antimicrobial susceptibility patterns of Pasteurella multocida isolated from chickens and japanese quails in Brazil

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    Everlon Cid Rigobelo


    Full Text Available A study was performed to verify the presence of Pasteurella multocida in eight different poultry groups of 90 birds each. Groups I to IV were chickens (I being > 6 weeks of age with a history of respiratory illness, II > 6 weeks of age and free of respiratory illness, III < 6 weeks of age with respiratory illness and IV being < 6 weeks of age and with no respiratory illness. Groups V to VIII had the matching characteristics of Groups I to V but consisted of Japanese Quails. The P. multocida isolation rate from the groups was as follows; Group I 56/90 (62.3% Group II 18/90 (20.0%, Group III 12/90 (13.3%, Group IV 3/90 (3.33%, Group V 8/90 (8.88%, Group VI 2/90 (2.22% Group VII 2/90 (2.22% and Group VIII 1/90 (1.11%. These isolation rates were not significantly different within the groups of a bird type but the overall chicken isolation rate was significantly higher than the quail isolation rate (p < 0.01. All isolates were examined for their sensitivity to four antimicrobial agents. The results showed only low levels of resistance to the agents tested. The highest level of resistance detected was to cephalothin (5.1% of isolates followed by amikacin (3.4%.

  20. Experience with a drug formulary in a large Italian city hospital. (United States)

    Zaccara, A; Sirtori, C R; Marchesi, F


    The preparation and distribution of a drug formulary, providing some 377 pharmacological entities together with significant general information, in a large city hospital, enabled the collection of data on the pattern of drug use in this setting. Out of the 377 selected drugs, 27 were never used in the course of one year: most notable among these were the cephalosporin cephalothin, the antifungal griseofulvin, piperazine and the leading anti-H1-blocker terfenadine. Thirteen pharmaceutical preparations were used in over 50,000 doses; among these were the amiloride + hydrochlorothiazide combination, co-trimoxazole and lorazepam. Examination of specific drug series, e.g. of cephalosporins, showed a clear preference for the longer acting ceftriaxone versus a minor use for oral agents, e.g. cefadroxil. There was a wide choice of cardiovascular agents and a relative stability in the preference for major and minor antipsychotics. Outside of the formulary list, only a small number of preparations were requested, among these some traditional analgesic combinations and some extractive products. The provision of a hospital formulary may, in some way, modify drug choice in the hospital, although some established patterns of use are difficult to change. On the other hand, some interesting information was provided on the criteria of choice of hospital physicians.

  1. Distribution of virulence determinants among antimicrobial-resistant and antimicrobial-susceptible Escherichia coli implicated in urinary tract infections

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    SAM Stephenson


    Full Text Available Introduction: Uropathogenic Escherichia coli (UPEC rely on the correlation of virulence expression with antimicrobial resistance to persist and cause severe urinary tract infections (UTIs. Objectives: We assessed the virulence pattern and prevalence among UPEC strains susceptible and resistant to multiple antimicrobial classes. Methods: A total of 174 non-duplicate UPEC strains from patients with clinically significant UTIs were analysed for susceptibility to aminoglycoside, antifolate, cephalosporin, nitrofuran and quinolone antibiotics for the production of extended-spectrum β-lactamases and for the presence of six virulence determinants encoding adhesins (afimbrial, Type 1 fimbriae, P and S-fimbriae and toxins (cytotoxic necrotising factor and haemolysin. Results: Relatively high resistance rates to nalidixic acid, ciprofloxacin, cephalothin and trimethoprim-sulfamethoxazole (82%, 78%, 62% and 59%, respectively were observed. Fourteen distinct patterns were identified for the virulence determinants such as afaBC, cnfI, fimH, hylA, papEF and sfaDE. The toxin gene, cnfI (75.3%, was the second most prevalent marker to the adhesin, fimH (97.1%. The significant association of sfaDE/hylA (P < 0.01 among antimicrobial resistant and susceptible strains was also observed notwithstanding an overall greater occurrence of virulence factors among the latter. Conclusions: This study provides a snapshot of UPEC complexity in Jamaica and highlights the significant clonal heterogeneity among strains. Such outcomes emphasise the need for evidence-based strategies in the effective management and control of UTIs.

  2. Escherichia coli Strains Isolated from the Uteri Horn, Mouth, and Rectum of Bitches Suffering from Pyometra: Virulence Factors, Antimicrobial Susceptibilities, and Clonal Relationships among Strains (United States)

    Agostinho, Juliana M. A.; de Souza, Andressa; Schocken-Iturrino, Ruben P.; Beraldo, Lívia G.; Borges, Clarissa A.; Ávila, Fernando A.; Marin, José M.


    Pyometra is recognized as one of the main causes of disease and death in the bitch, and Escherichia coli is the major pathogen associated with this disease. In this study, 70 E. coli isolates from the uteri horn, mouth, and rectum of bitches suffering from the disease and 43 E. coli isolates from the rectum of clinically healthy bitches were examined for the presence of uropathogenic virulence genes and susceptibility to antimicrobial drugs. DNA profiles of isolates from uteri horn and mouth in bitches with pyometra were compared by REP, ERIC, and BOX-PCR. Virulence gene frequencies detected in isolates from canine pyometra were as follows: 95.7% fim, 27.1% iss, 25.7% hly, 18.5% iuc, and 17.1% usp. Predominant resistance was determined for cephalothin, ampicillin, and nalidixic acid among the isolates from all sites examined. Multidrug resistance was found on ∼50% pyometra isolates. Using the genotypic methods some isolates from uteri, pus, and saliva of the same bitch proved to have identical DNA profiles which is a reason for concern due to the close relationship between household pets and humans. PMID:24734047


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    Fernanda Santana Oliveira


    Full Text Available The endothelial pyometra is a disease that affects more frequently reproductively active adult females. Characterized by inflammation and accumulation of exudate in the uterine cavity, generally associated with bacterial infections. The present study aimed to evaluate the resistance profile of Escherichia coli isolates from 42 female dogs diagnosed with pyometra, seen at the Department of Small Animal Surgery, Hospital of Veterinary Medicine, Federal University of Bahia. To perform the bacteriological analysis, a sample of the contents of the uterus was obtained immediately after surgery of ovariosalpingohisterectomy therapy (OSH and sent to the laboratory. Microbiological analysis showed a predominance of the bacterium Escherichia coli in 40.5% (15/37. Strains of Escherichia coli isolates showed higher rates of resistance to antimicrobial erythromycin (93.3 %, azithromycin (80 %, ampicillin, amoxicillin, and cephalothin (40% each. This study reinforces the need to perform the microbiological examination for epidemiological purposes and the correct therapeutic application, thereby avoiding the indiscriminate use of antimicrobials and the potential emergence of multidrug-resistant  strains. Keywords: bacteria; multiresistant;  uterus.

  4. Escherichia coli Strains Isolated from the Uteri Horn, Mouth, and Rectum of Bitches Suffering from Pyometra: Virulence Factors, Antimicrobial Susceptibilities, and Clonal Relationships among Strains

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    Juliana M. A. Agostinho


    Full Text Available Pyometra is recognized as one of the main causes of disease and death in the bitch, and Escherichia coli is the major pathogen associated with this disease. In this study, 70 E. coli isolates from the uteri horn, mouth, and rectum of bitches suffering from the disease and 43 E. coli isolates from the rectum of clinically healthy bitches were examined for the presence of uropathogenic virulence genes and susceptibility to antimicrobial drugs. DNA profiles of isolates from uteri horn and mouth in bitches with pyometra were compared by REP, ERIC, and BOX-PCR. Virulence gene frequencies detected in isolates from canine pyometra were as follows: 95.7% fim, 27.1% iss, 25.7% hly, 18.5% iuc, and 17.1% usp. Predominant resistance was determined for cephalothin, ampicillin, and nalidixic acid among the isolates from all sites examined. Multidrug resistance was found on ∼50% pyometra isolates. Using the genotypic methods some isolates from uteri, pus, and saliva of the same bitch proved to have identical DNA profiles which is a reason for concern due to the close relationship between household pets and humans.

  5. The microbiological quality of ready-to-eat salads in Turkey: a focus on Salmonella spp. and Listeria monocytogenes. (United States)

    Gurler, Zeki; Pamuk, Sebnem; Yildirim, Yeliz; Ertas, Nurhan


    The microbiological safety of ready-to-eat (RTE) foods is of special concern as they are not exposed to further processing before consumption. In the present study, Listeria monocytogenes and Salmonella spp. were isolated from 15(6%) and 21(8%) samples respectively out of 261 RTE foods commercialized in Turkey. Escherichia coli was present in 10(4%) samples analyzed. Psychrotrophic aerobic populations >6logCFU/g were found in 36 (14%) of the samples, while total coliforms were detected in 155 (59%) of samples analyzed. All of the Salmonella spp. and L. monocytogenes isolates tested, exhibited resistance to one or more antimicrobial agents used. For Salmonella spp. isolates, resistance to penicillin (69%), erythromycin (38%), gentamicin (36%), tetracycline (36%) neomycin (33%), ampicillin (33%), amikacin (33%), vancomycin (33%), streptomycin (29%) cefotaxime (9%) and oxacillin (9%) was observed. For L. monocytogenes isolates, resistance to erythromycin (23%) and cephalothin (20%) was evident. The presence of pathogens and the relatively high resistance among the bacteria tested in RTE foods could pose public health and therapeutic problems in consumers. These results indicate the need of implementing hygienic rules in the production chain of RTE foods to ensure microbiological safety and to improve shelf life. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Prevalence and antimicrobial resistance of Listeria, Salmonella, and Yersinia species isolates in ducks and geese. (United States)

    Jamali, Hossein; Radmehr, Behrad; Ismail, Salmah


    The aims of this study were to determine the prevalence and antimicrobial resistance of Listeria, Salmonella, and Yersinia spp. isolated from duck and goose intestinal contents. A total of 471 samples, including 291 duck and 180 goose intestinal contents, were purchased from wet markets between November 2008 and July 2010. Listeria, Salmonella, and Yersinia spp. were isolated from 58 (12.3%), 107 (22.7%), and 80 (17%) of the samples, respectively. It was concluded that Listeria ivanovii, Salmonella Thompson, and Yersinia enterocolitica were the predominant serovars among Listeria, Salmonella, and Yersinia spp., respectively. Moreover, resistance to tetracycline was common in Listeria (48.3%) and Salmonella spp. (63.6%), whereas 51.3% of the Yersinia spp. isolates were resistant to cephalothin. Therefore, continued surveillance of the prevalence of the pathogens and also of emerging antibiotic resistance is needed to render possible the recognition of foods that may represent risks and also ensure the effective treatment of listeriosis, salmonellosis, and yersiniosis.

  7. Backyard chicken flocks pose a disease risk for neotropic birds in Costa Rica. (United States)

    Hernandez-Divers, Sonia M; Villegas, Pedro; Jimenez, Carlos; Hernandez-Divers, Stephen J; Garcia, Maricarmen; Riblet, Sylva M; Carroll, C Ron; O'Connor, Barry M; Webb, Julie L; Yabsley, Michael J; Williams, Susan M; Sanchez, Susan


    Pathogens of free-ranging chickens create a risk of disease for wild birds, some of which migrate to the United States, as well as potential economic losses for resource-poor farmers. Free-roaming backyard chickens are commonly kept in shade-grown coffee plantations, habitats that attract large numbers of wild birds. The husbandry and pathogen prevalence of backyard chicken flocks in San Luis, Costa Rica, were investigated. Based on serologic evidence, Newcastle disease virus, infectious laryngotracheitis virus, infectious bronchitis virus, chicken anemia virus, and infectious bursal disease virus, as well as both Mycoplasma gallisepticum and Mycoplasma synoviae, appear to be significant diseases of this population, and thus, we consider these backyard chickens potential reservoirs for these diseases. There was no evidence of avian influenza. Interviews, clinical examinations, and microscopic examination of tissues led us to believe that poxvirus is also a significant cause of morbidity and mortality in these chickens. We found that Escherichia coli isolates were resistant against tilmicosin, tetracycline, ampicillin, amoxicillin with clavulanic acid, ticarcillin, and cephalothin, and contained genes considered responsible for conferring tetracycline resistance. Additionally, although production was not measured, we suspect that husbandry and lack of preventative medicine are directly related to the diseases reported, all of which negatively affect production.

  8. Prevalence and Sensitivity of Bacilli and Pseudomonas in the Newborn's Oral Cavity. (United States)

    Ferreira, Priscila Vitor Alves; Amêndola, Isabela; Oliveira, Luciane Dias de; Silva, Célia Regina Gonçalves E; Leão, Mariella Vieira Pereira; Santos, Silvana Soléo Ferreira Dos


    The aim of this study was to isolate Enterobacteria and Pseudomonas from the oral cavity of hospitalized newborns (NB) and determine their prevalence and the sensitivity profile to most commonly used antibiotics for this age group. Samples from the oral cavity of NB from 24 to 48 h age were collected using swabs. The samples were inoculated on MacConkey agar, incubated and the colonies counted and identified. For each strain, the minimum inhibitory concentration (MIC) was determined using agar dilution test. Tests for enterobacteria producing extended spectrumβ-lactamases (ESBL) were performed using agar diffusion. Descriptive statistics was used for data analysis. Two of the isolated strains were submitted to the susceptibility test in biofilm. Of the collected samples, 8% presented Enterobacteria (mean of 6,141 CFU/mL) and no Pseudomona species was isolated. Positive samples were from NB in accommodation set or in the NB nursery. Enterobacter was the most prevalent genus and some strains were resistant to ampicillin, gentamicin and cephalothin. No ESBL strain was detected. Microorganisms in biofilms were resistant to all antibiotics, with concentrations four times higher than MIC. The presence of enterobacteria in the oral cavity of newborns, especially some strains resistant to normally used antibiotics, warns to the need for care to avoid the early colonization of this niche and the occurrence of a possible hospital infection in this age group.

  9. Isolation of Salmonella spp. from lettuce and evaluation of its susceptibility to novel bacteriocins of Bacillus thuringiensis and antibiotics. (United States)

    Castañeda-Ramírez, Cristobal; Cortes-Rodríguez, Viridiana; de la Fuente-Salcido, Norma; Bideshi, Dennis K; del Rincón-Castro, M Cristina; Barboza-Corona, J Eleazar


    In this study, 13% of fresh lettuce (Lactuca sativa) samples collected from markets and supermarkets in two cities of Mexico were contaminated with Salmonella spp. From those samples, amplicons of ∼300 base pairs (bp) were amplified, corresponding to the expected size of the invasion (invA) and internal transcribed spacer regions of the 16S and 23S rRNA genes of Salmonella spp. Additionally, Salmonella strains were isolated and harbored plasmids ranging from ∼9 to 16 kbp. From these strains, 91% were resistant to ampicillin and nitrofurantoin, whereas 55% were resistant to cephalothin and chloramphenicol. No resistance was detected to amikacin, carbenicillin, cefotaxime, gentamicin, netilmicin, norfloxacin, and sulfamethoxazole-trimethoprim. When Salmonella isolates were tested against novel bacteriocins (morricin 269, kurstacin 287, kenyacin 404, entomocin 420, and tolworthcin 524) produced by five Mexican strains of Bacillus thuringiensis, 50% were susceptible to these antimicrobial peptides. This is the first report showing that Salmonella strains isolated from lettuce are susceptible to bacteriocins produced by the most important bioinsecticide worldwide, suggesting the potential use of these antibacterial peptides as therapeutic agents or food preservatives to reduce or destroy populations of Salmonella spp. Copyright ©, International Association for Food Protection

  10. Comparative analysis of virulence and resistance profiles of Salmonella Enteritidis isolates from poultry meat and foodborne outbreaks in northern Jordan. (United States)

    Jaradat, Ziad W; Abedel Hafiz, Leena; Ababneh, Mustafa M; Ababneh, Qotaibah O; Al Mousa, Waseem; Al-Nabulsi, Anas; Osaili, Tareq M; Holley, Richard


    This study was conducted to isolate Salmonella Enteritidis from poultry samples and compare their virulence and antibiotic resistance profiles to S. Enteritidis isolated from outbreaks in northern Jordan. Two hundred presumptive isolates were obtained from 302 raw poultry samples and were subjected to further analysis and confirmation. A phylogenic tree based on 16S rRNA sequencing was constructed and selected isolates representing each cluster were further studied for their virulence in normal adult Swiss white mice. The most virulent strains were isolated from poultry samples and had an LD 50 of 1.55 × 10 (5) CFU, while some of the outbreak isolates were avirulent in mice. Antibiotic resistance profiling revealed that the isolates were resistant to seven of eight antibiotics screened with each isolate resistant to multiple antibiotics (from two to six). Of the poultry isolates, 100%, 88.9%, 77.8%, 66.7%, and 50% showed resistance to nalidixic acid, ciprofloxacin, ampicillin, cephalothin, and cefoperazone, respectively. Two outbreak isolates were sensitive to all tested antibiotics, while 71.4% were resistant to cefoperazone and only 28.6% showed resistance to nalidixic acid. Salmonella outbreak isolates were genetically related to poultry isolates as inferred from the 16S rRNA sequencing, yet were phenotypically different. Although outbreak strains were similar to poultry isolates, when tested in the mouse model, some of the outbreak isolates were highly virulent while others were avirulent. This might be due to a variation in susceptibility of the mouse to different S. Enteritidis isolates.

  11. Chronic osteomyelitis in children: treatment by intramedullary reaming and antibiotic-impregnated cement rods. (United States)

    Bar-On, Elhanan; Weigl, Daniel M; Bor, Noam; Becker, Tali; Katz, Kalman; Mercado, Eyal; Livni, Gilat


    Chronic osteomyelitis (CO) is rarely encountered in developed countries and is especially rare in children and adolescents. However, on occurrence, it can pose a difficult therapeutic challenge necessitating a combination of aggressive surgical treatment and prolonged antibiotic administration. Four patients were treated for CO in the Pediatric Orthopaedic Unit at Schneider Children's Medical Center between June 2005 and December 2006 and were reviewed retrospectively. Surgical treatment consisted of debridement and lavage, reaming of the intramedullary canal and insertion of gentamycin-impregnated polymetamethacrylate rods into the canal and beads around the infection site. At rod removal reaming and lavage were repeated. Antibiotic treatment was initiated with intravenous cephalothin, followed by prolonged oral treatment according to bacterial sensitivity. Cement rods and beads were removed 16 to 62 days after insertion. Intravenous antibiotics were continued for 6 weeks (3-13) and total antibiotic treatment length was 16 weeks (10-37). Total treatment time from presentation to full resolution averaged 8 months (2-18). One patient sustained a fracture requiring osteotomy and correction. At mean follow-up of 41 months from rod removal (36-46), all patients are asymptomatic and fully functional with no clinical signs of infection. C-reactive protein is within normal limits in all 4 patients. The method presented combining reaming, lavage and local and systemic antibiotic treatment was found to be safe and effective in the treatment of CO, eradicating the infection and preventing further tissue loss. Therapeutic study, clinical case series: level IV.

  12. Epidemiology of Antibiotic and Heavy Metal Resistance in Bacteria: Resistance Patterns in Staphylococci Isolated from Populations in Iraq Exposed and Not Exposed to Heavy Metals or Antibiotics (United States)

    Groves, David J.; Short, H.; Thewaini, A. J.; Young, Frank E.


    Staphylococci were isolated from rural and urban populations in Iraq, which were not known to be exposed to either heavy metals or antibiotics. The antibiotic and heavy metal resistance patterns of these strains were analyzed in both mannitol-fermenting and nonfermenting strains. Over 90% of the strains were resistant to at least one of the following antibiotics: penicillin, chloramphenicol, erythromycin, tetracycline, cephalothin, lincomycin, or methicillin. In general, mannitol-fermenting strains were resistant to penicillin and cupric ions. Mannitol-negative strains were more frequently associated with mercuric ion and tetracycline resistance. Although resistance to penicillin and tetracycline can coexist, the combination of penicillin resistance and tetracycline resistance usually occurred in mannitol-negative strains. The possibility of selection of heavy metal-resistant strains due to exposure to toxic levels of methylmercury was examined. No significant increase in mercuric ion-resistant strains of staphylococci or Escherichia coli were detected in exposed populations as compared to control groups. The possible reasons for this result are discussed. PMID:1147593

  13. Multiple antibiotic-resistant bacteria on fluted pumpkin leaves, a herb of therapeutic value. (United States)

    Igbeneghu, Oluwatoyin A; Abdu, Abdulrasheed B


    Fluted pumpkin (Telfairia occidentalis) is a minimally-processed green leafy vegetable traditionally used for its antianaemic properties in the form of leaf juice without a heating or inactivation step before consumption. The aim of the study was to assess the presence of surface microbiota on T. occidentalis leaves and also to determine the antimicrobial susceptibility of isolated organisms. Bacterial contaminants on 50 samples of T. occidentalis leaves were isolated and characterized using standard biochemical methods and the antimicrobial susceptibility of isolated organisms was determined using the antibiotic disc diffusion assay. The results obtained show that the leaves of T. occidentalis is contaminated with organisms which included Enterobacter agglomerans (25.9%), Proteus vulgaris (24.9%), Klebsiella spp. (2.6%), and Serratia liquefaciens (2.1%). Other bacterial isolates recovered in order of frequency included: Staphylococcus spp. (33.7%), Bacillus spp. (8.3%), and Pseudomonas fluorescens (2.6%). Of the 193 bacterial isolates from the leaves of T. occidentalis samples tested for antimicrobial resistance, all (100%) were found to be resistant to ampicillin, cloxacillin, augmentin, erythromycin, and tetracycline while 96% of the isolates were resistant to cephalothin. Resistance to trimethoprim (93%) and gentamicin (83%) was also observed. Approximately, 22% of the isolates were resistant to ciprofloxacin; however, only 11 (5.8%) were resistant to ofloxacin. Thus, uncooked T. occidentalis is a potential source of highly-resistant epiphytic bacteria which could be opportunistic pathogens in consumers.

  14. Use of selected cephalosporins in penicillin-allergic patients: a paradigm shift. (United States)

    Pichichero, Michael E


    Recent analysis of clinical data and a clearer understanding of the role of chemical structure in the development of cross-reactivity indicate that the increased risk of an allergic reaction to certain cephalosporins in penicillin-allergic patients is smaller than previously postulated. Medline and EMBASE databases were searched using the following keywords: cephalosporin, penicillin, allergy, and cross-sensitivity for the years 1960 to 2005. Among 219 articles retrieved, 106 served as source material for this review. A significant increase in allergic reactions to cephalothin, cephaloridine, cephalexin, cefazolin, and cefamandole was observed in penicillin-allergic patients; no increase was observed with cefprozil, cefuroxime, ceftazidime, or ceftriaxone. Clinical challenges, skin testing, and monoclonal antibody studies point to the paramount importance of similarities in side chain structure to predict cross-allergy between cephalosporins and penicillins. First-generation cephalosporins have a modest cross-allergy with penicillins, but cross-allergy is negligible with 2nd- and 3rd-generation cephalosporins. Particular emphasis is placed on the role of chemical structure in determining the risk of cross-reactivity between specific agents.

  15. Campylobacter hepaticus sp. nov., isolated from chickens with spotty liver disease. (United States)

    Van, Thi Thu Hao; Elshagmani, Eltaher; Gor, Mian Chee; Scott, Peter C; Moore, Robert J


    Ten strains of an unknown Campylobacter species were isolated from the livers of chickens with spotty liver disease in Australia. The strains were Gram-stain-negative, microaerobic, catalase- and oxidase-positive and urease-negative. Unlike most other species of the genus Campylobacter, most of the tested strains of this novel species hydrolysed hippurate and half of them could not reduce nitrate. All strains showed resistance, or intermediate resistance, to nalidixic acid and most of them were resistant to cephalothin. Examination of negatively stained cells under transmission electron microscopy revealed that they were S-shaped, with bipolar unsheathed flagella. Phylogenetic analyses based on the 16S rRNA gene and the heat shock protein 60 (hsp60) gene sequences indicated that the strains formed a robust clade that was clearly distinct from recognized Campylobacter species. Unusually, they had a DNA G+C content of 27.9 mol%, lower than any previously described Campylobacter species, and they showed less than 84 % average nucleotide identity to the nearest sequenced species. Taken together, these data indicate that the strains belong to a novel Campylobacter species, for which the name Campylobacter hepaticus sp. nov. is proposed. The type strain is HV10T (=NCTC 13823T=CIP 111092T).

  16. Prevalence of methicillin-resistant Staphylococci on a farm: staff can harbour MRS when animals do not. (United States)

    Aquino, G de V; Maluta, R P; de Ávila, F A


    The aim of this work was to establish the prevalence of methicillin-resistant Staphylococci (MRS) in the animals and staff of a teaching and research farm. Samples of dairy cattle (36), beef cattle (26), sheep (19), horses (21), pigs (23), goats (23) and humans (13) were collected and screened for the presence of MRS. The detection of mecA gene was performed by PCR to determine the resistance of the samples to methicillin. Antimicrobial-resistance testing to penicillin, meropenem, ceftriaxone, cephalothin, oxacillin, levofloxacin, enrofloxacin, chloramphenicol, ciprofloxacin, gentamicin, clindamycin, erytromycin, linezolid, sulfamethoxazole/trimethoprim, tetracycline, doxycycline and vancomycin was performed on the mecA+ isolates. From the 161 samples, four methicillin-resistant coagulase-negative Staphylococci (MRCoNS) were isolated from human beings (31%), whereas none was isolated from animals (0%). No methicillin-resistant Staphylococcus aureus (MRSA) were isolated. All of the MRCoNS isolates from this work presented different antimicrobial resistance patterns. MRCoNS may be present in humans associated with animals while not present in the animals. Selective pressure outside of the farm and a lack of MRCoNS transmission between humans and animals may be responsible for this lack of correlation. © 2011 Blackwell Verlag GmbH.

  17. Prevalence and distribution of Vibrio parahaemolyticus in finfish from Cochin (south India

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    Ammanamveetil A.M. Hatha


    Full Text Available Finfish samples obtained from four retail outlets in Cochin between June 2009 and June 2010 were investigated for the occurrence of Vibrio parahaemolyticus. A total of 182 samples were collected and suspect isolates were identified using standard biochemical tests and were further confirmed by a species-specific tlh gene. V. parahaemolyticus was detected in 45.1% of samples, with demersal fish being more affected than pelagic species. The bacterium was isolated more frequently from the skin and gills of pelagic fish, while the intestine yielded greater numbers of V. parahaemolyticus in demersal fish. The highest incidence of antibiotic resistance was recorded against ampicillin and streptomycin, followed by carbenicillin, cefpodoxime, cephalothin, colistin and amoxycillin; the lowest was against nalidixic acid, tetracycline, chloramphenicol and ciprofloxacin. Multiple drug resistance was prevalent among isolates. Although only a fraction of strains are pathogenic for humans, the time-temperature abuse in markets provides ample scope for these strains to multiply to dangerous levels. The multidrug resistant nature of the strains adds to the gravity of the problem. High V. parahaemolyticus incidence rates in market finfish samples from areas in and around Cochin clearly indicates that control measures should be adopted to reduce post-harvest contamination in seafood and time-temperature abuse in markets to diminish the risk of V. parahaemolyticus infection associated with seafood destined for human consumption.

  18. Acinetobacter johnsonii and Acinetobacter lwoffii - the emerging fish pathogens

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    Kozińska Alicja


    Full Text Available The aim of this study was to characterise Acinetobacter sp. isolated from fish. Eight isolates obtained from diseased rainbow trout and common carp cultured in Poland were analysed. The isolates were identified using API 20 NE system as Acinetobacter sp. Afterwards, they were identified by sequencing 16S rDNA gene fragment. The bacteria were identified as A. johnsonii (two isolates, A. lwoffii (two isolates, A. junii/johnsonii (one isolate, A. calcoaceticus (one isolate, and Acinetobacter sp. (two isolates. The drug resistance of isolates was examined. The majority of the isolates were resistant to ampicilin, amoxicillin, and cephalothin and all demonstrated sensitivity to fluoroquinolones, except of one isolate. Two isolates were selected for the experimental infection of trout and carp to confirm their pathogenicity. Experimentally infected fish showed disease symptoms similar to those observed in fish naturally infected with these bacteria. This is the first report concerning pathogenicity of A. johnsonii for rainbow trout and A. lwoffii for common carp. These bacteria were regarded as emerging opportunistic pathogens of fish farmed in Poland. Acinetobacter strains are commonly known as microorganisms transmitting the antibiotic resistance genes. Therefore, they might have a great impact on the resistance transfer in aquaculture.

  19. Drug resistance, AmpC-β-lactamase and extended-spectrum β-lactamase-producing Enterobacteriaceae isolated from fish and shrimp. (United States)

    Almeida, Marília Viana Albuquerque de; Cangussú, Ítalo Mendes; Carvalho, Antonia Leonadia Siqueira de; Brito, Izabelly Linhares Ponte; Costa, Renata Albuquerque


    The present study aims to detect the production of extended-spectrum beta-lactamases (ESBL) by enterobacteria isolated from samples of fresh shrimp and fish obtained from the retail trade of the city of Sobral, Ceará State, Brazil. All bacterial isolates were submitted to identification and antimicrobial susceptibility testing using aminopenicillin, beta-lactamase inhibitors, carbapenem, 1st, 2nd, 3rd and 4th generation cephalosporins, and monobactam. Three types of beta-lactamases - ESBL, AmpC and KPC - were investigated. 103 strains were identified, and the most frequent species in shrimp and fish samples was Enterobacter cloacae (n = 54). All the strains were resistant to penicillin and more than 50% of the isolates were resistant to ampicillin and cephalothin. Resistance to three 3rd generation cephalosporins (cefotaxime, ceftriaxone and ceftazidime) and one fourth generation cephalosporin (cefepime) was detected in two isolates of E. cloacae from shrimp samples. Phenotypic detection of AmpC was confirmed in seven strains. The ESBL was detected in two strains of E. cloacae from shrimp samples. No strain showed KPC production. These data can be considered alarming, since food (shrimp and fish) may be carriers of enterobacteria resistant to drugs of clinical interest.

  20. Comparison of antimicrobial resistance in Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes strains isolated from organic and conventional poultry meat. (United States)

    Miranda, J M; Vázquez, B I; Fente, C A; Calo-Mata, P; Cepeda, A; Franco, C M


    The presence of Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes was determined in 55 samples of organic poultry meat and in 61 samples of conventional poultry meat. A total of 220 E. coli, 192 S. aureus, and 71 L. monocytogenes strains were analyzed by an agar disk diffusion assay for their resistance to ampicillin, cephalothin, chloramphenicol, ciprofloxacin, doxycycline, fosfomycin, gentamicin, nitrofurantoin, streptomycin, and sulfisoxazole (E. coli); chloramphenicol, ciprofloxacin, clindamycin, doxycycline, erythromycin, gentamicin, nitrofurantoin, oxacillin, and sulfisoxazole (S. aureus); and chloramphenicol, doxycycline, erythromycin, gentamicin, sulfisoxazole, and vancomycin (L. monocytogenes). The results indicated a significantly higher (P organic poultry meat as compared with conventional poultry meat. E. coli isolated from organic poultry meat exhibited lower levels of antimicrobial resistance against 7 of the 10 antimicrobials tested as compared with isolates recovered from conventional meat. In the case of S. aureus and L. monocytogenes isolated from conventional poultry, antimicrobial resistance was significantly higher only for doxycycline as compared with strains isolated from organic poultry. In the case of E. coli, the presence of multiresistant strains was significantly higher (P conventional poultry meat as compared with organic poultry meat. Organically farmed poultry samples showed significantly lower development of antimicrobial resistance in intestinal bacteria such as E. coli.

  1. Prevalence of Pharyngeal Pneumococcal Carriers and Succeptibility Patterns among Children of Day Care Centers in Yazd District,Iran

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    M Mohammad - Zadeh


    Full Text Available Introduction: Streptococcus pneumoniae is one of the most important causes of pneumonia, meningitis and septicemia. Decades after successful treatment of this infection with penicillin, frequency of penicillin resistance is reportedly on the rise throughout the world. This cross sectional study was designed in Yazd to determine the prevalence of pneumococcal pharyngeal carriers and its succeptibility pattern in children of day care centers. Method & materials : Two hundred children were selected randomly from 10 day care centers and pharyngeal swabs were collected and cultured in February, 2002. Results :51% of our study sample were boys and 49% were girls. Their age range was between 7 and 65 months. Prevalence of pharyngeal carriers was 37.5%. The rate of resistance detected was as follows: 50% to penicillin, 62.5% to erythromycin and TMP,SMX, 30.6% to tetracycline, 15.3 % to cephalothin, 5.6% to ceftizoxime and 4.2% to ciprofloxacin. Conclusion: We conclude that penicillin is not the drug of choice in invasive pneumococcal infections in Yazd and a third gereration cephalosporin should be used instead as the first line of treatment while awaiting the culture and sensitivity results.

  2. Determination of several potential virulence factors in non-o1 Vibrio cholerae, Pseudomonas aeruginosa, faecal coliforms and streptococci isolated from Marrakesh groundwater. (United States)

    Lamrani Alaoui, Hafsa; Oufdou, Khalid; Mezrioui, Nour-Eddine


    The dynamic, hemolytic and hemagglutination activities and the antibiotic resistance of non-O1 Vibrio cholerae, Pseudomonas aeruginosa, faecal coliforms (FC) and faecal streptococci (FS), isolated by standard membrane filtration methods from suburban and rural groundwater supplies, were carried out. Detectable non-O1 V. cholerae and P. aeruginosa was present in 81% and 88% of samples. The total occurrence of FC and FS during the period of study was 94%. The annual average densities of non-O1 V. cholerae were 4,903 MPN/100 mL. While, they were 206, 1,891 and 1,246 cfu/100 mL for P. aeruginosa, FC and FS respectively. Non-O1 V. cholerae strains had the highest percentage of hemolytic activities (alpha + beta) (71.29%), whereas 20.71% of FS, 16.88% of FC and 9.13% of P. aeruginosa strains produced hemolysin. Bacterial strains isolated were found to be adhesive, with percentages of 63.09%, 65.09%, 84.06% and 87.98% respectively for non-O1 V. cholerae, FS, FC and P. aeruginosa. As for antibiotic resistance, the overall resistance of non-O1 V. cholerae strains was 79%, whereas it was 100% for the other bacteria. Non-O1 V. cholerae resistance was expressed towards sulfamethoxazole (75%), streptomycin (62%) and cephalothin (60%). Obtained results indicated correlation between bacteriological pollution and their public health implications.

  3. Ecological aspects of the antimicrobial resistence in bacteria of importance to humn infections

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    Meirelles-Pereira Frederico de


    Full Text Available In view of the intimate relationship of humans with coastal lagoons (used for recreation, tourism, water supply, etc., the discharge of domestic effluents may lead to the establishment of routes of dissemination of pathogenic microorganisms, including microorganisms carrying genes for resistance to antimicrobials, through the surrounding human communities. The objective of the present investigation was to relate the presence of antimicrobial-resistant bacteria to the environmental characteristics of three coastal lagoons, comparing the results with those from hospital sewage. Of the lagoons evaluated, two (Geribá and Imboassica receive domestic sewage discharge, and the other (Cabiúnas is still in a natural state. We isolated in a culture medium containing 32 ¼ µg/ml of Cephalothin, fecal coliforms (E. coli, non-fecal coliforms (Klebsiella, Enterobacter, Serratia, and Citrobacter, non-glucose-fermenting Gram-negative bacilli, and Aeromonas sp. In cultures from the hospital drain we found strains showing numerous markers for resistance to most of the 11 antimicrobials tested. On the other hand, in cultures from Cabiúnas and Imboassica lagoons, we found strains showing resistance only to antibiotics frequently observed in non-selective situations (considered as "common" markers. The capacity for dilution in the ecosystem, and salinity appeared related with the occurrence of multi-resistant bacterial strains. The intensity of recent fecal contamination was not shown to be associated with the numbers and types of markers found.

  4. Antimicrobial susceptibility and glycopeptide-resistance of enterococci in vegetables

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    Ida Torre


    Full Text Available

    Background: Vancomycin-resistant enterococci (VRE, often responsible for nosocomial infections, have frequently been isolated from animal and vegetable foods. In our study we evaluated the antibiotic susceptibility of enterococci isolated from eight types of vegetables randomly selected from grocery stores in Naples.

    Methods: From July to November 2008, we analyzed 150 samples: the bacteria were isolated with standardized methods and antibiotic susceptibility was determined using the disc diffusion method. The resistance to vancomycin versus other antibiotics was assessed by the Kappa test.

    Results: 70% of the samples, mainly parsley (96.2%, showed enterococci. Of these, 59.1% belonged to the species Enterococcus faecium. Strains resistant to vancomycin and teicoplanin were isolated respectively in 47.6% and 49.5% of the samples: the first one mainly in curly endive (72.7% and the second one in parsley (76.9%. Almost all the isolated strains showed resistance to methicillin (89%, kanamycin (82% and cephalothin (68%. The Kappa test showed statistically significant associations between resistance to vancomycin and resistance to teicoplanin, erythromycin, methicillin, tetracycline and chloramphenicol.

    Conclusions: Because of the possible involvement of food in the transmission of resistant micro-organisms to human intestinal microbiota, our data may provide the basis for future studies.

  5. High occurrence of extended-spectrum β-lactamase-producing Salmonella in broiler carcasses from poultry slaughterhouses in South Korea. (United States)

    Chon, Jung-Whan; Jung, Hae-In; Kuk, Min; Kim, Young-Ji; Seo, Kun-Ho; Kim, Soo-Ki


    The emergence of antibiotic-resistant foodborne Salmonella has become a major public health problem. Consumption of undercooked poultry contaminated with Salmonella can induce food poisoning in humans. In this study, we investigated the occurrence and antibiotic resistance patterns of Salmonella spp. isolated from 120 chicken carcasses produced in 6 poultry slaughterhouses in South Korea. A total of 11 samples (9.2%) were found contaminated with Salmonella: 5 isolates were serotyped as Salmonella Bellevue strain (slaughterhouse C) and 6 isolates were serotyped as Salmonella Enteritidis strain (slaughterhouse E). Salmonella Bellevue isolates were resistant to five antibiotics (ampicillin, chloramphenicol, nalidixic acid, tetracycline, and trimethoprim/sulfamethoxazole), while Salmonella Enteritidis isolates were resistant to nine antibiotics (ampicillin, cefotaxime, ceftazidime, cefazolin, cephalothin, amikacin, nalidixic acid, streptomycin, and tetracycline). All cephalosporin-resistant Salmonella Enteritidis isolates exhibited the extended-spectrum β-lactamase (ESBL) phenotype and carried the gene encoding CTX-M-15, the most prevalent ESBL enzyme worldwide. Based on molecular subtyping performed using the automated rep-polymerase chain reaction (PCR) system (DiversiLab), the isolates showing ≥ 95 similarity in their rep-PCR banding patterns were classified into 5 pulsotypes. Given that cephalosporins are the drugs of choice for invasive Salmonella infections, the high incidence of ESBL-producing strains in chicken should emphasize the necessity of regular monitoring of the occurrence of antibiotic-resistant ESBL-positive Salmonella strains in poultry meat.

  6. Role of residue Lys315 in the mechanism of action of the Enterobacter cloacae 908R beta-lactamase. (United States)

    Monnaie, D; Dubus, A; Cooke, D; Marchand-Brynaert, J; Normark, S; Frère, J M


    The role of the highly conserved Lys315 residue in the catalytic mechanism of a class C beta-lactamase has been probed by site-directed mutagenesis. Lys315 has been replaced by a histidine in the Enterobacter cloacae 908R beta-lactamase, thus introducing a tritratable group to probe the role of the positive charge, and by a glutamine. The effects of these mutations have been studied on the kinetics of penicillin G and cephalothin turnover and on the pre-steady-state kinetics with carbenicillin at different pH. Results showed that substrate binding was not impaired by the mutations, so that an interaction with the substrate-free carboxylate in the Henri-Michaelis complex could be ruled out. Lys315 must have a catalytic role as shown by the decreased acylation and deacylation rates observed with the mutant enzymes. The mutants exhibited a lower activity at acidic pH, and this observation could be correlated with a decreased affinity for (3-aminophenyl)boronate, a compound devoid of free carboxylate which binds to the active site and forms an adduct mimicking the tetrahedral intermediate. This suggested that Lys315 was somehow involved in accelerating the nucleophilic substitutions along the reaction pathway. The study was extended to modified substrates where the free carboxylate had been esterified. Neither acylation nor deacylation seemed severely impaired with these compounds, showing that the interaction between the enzyme and the substrate-free carboxylate did not play a major role in catalysis.

  7. Contact lens-related acanthamoeba keratitis. (United States)

    Stapleton, Fiona; Ozkan, Jerome; Jalbert, Isabelle; Holden, Brien A; Petsoglou, Con; McClellan, Kathy


    Acanthamoeba keratitis is a rare but severe disease, with more than 95% of cases occurring in contact lens wearers. With a worldwide resurgence of contact lens-related disease, this report illustrates the clinical characteristics and treatment challenges representative of this disease. This report describes Acanthamoeba keratitis in a 47-year-old female using extended wear silicone hydrogel contact lenses, with a history of swimming in a home pool and failure to subsequently disinfect the contact lenses. The diagnosis was based on clinical signs, disease course, and confocal microscopy results despite a negative result for corneal smear and culture. The corneal signs included an epithelial defect, epithelial irregularities, anterior stromal infiltrates, perineural infiltrates, an anterior stromal ring infiltrate, and hypopyon. The case was diagnosed as an infective keratitis and treated promptly using intensive topical administration of fortified gentamicin and cephalothin. The high likelihood Acanthamoeba prompted immediate use of polyhexamethylbiguanide and chlorhexidine, with propamide and adjunct treatment using atropine and oral diclofenac. Steroids were added on day 3, and the frequency of administration of antibacterial treatment was gradually reduced and ceased by day 10. The analgesia was stopped at 3 months. The frequency of administration of antiamoeba therapy and steroid treatment was slowly reduced and all treatment was ceased after 18 months. Despite considerable morbidity in terms of the treatment duration, hospitalization, outpatient appointments, and associated disease costs, the final visual outcome (6/6) was excellent.

  8. Prevalence and Antimicrobial Resistance of Salmonella Isolated from Animal-Origin Food Items in Gondar, Ethiopia

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    Mebrat Ejo


    Full Text Available Salmonella has been found to be the major cause of foodborne diseases and a serious public health problem in the world, with an increasing concern for the emergence and spread of antimicrobial-resistant strains. A cross-sectional study was conducted between February 2014 and December 2015 on food items of animal origin to assess the prevalence and antimicrobial resistance profiles of Salmonella isolates using standard bacteriological methods. The overall prevalence rate of 5.5% was recorded from the total analyzed food items of animal origin. Salmonella isolates were detected from 12% of raw meat, 8% of minced meat, 2.9% of burger samples, 18% of raw eggs, and 6% of raw milk. Furthermore, antimicrobial susceptibility test identified 47.6% resistant Salmonella isolates, 28.6% intermediately sensitive isolates, and 23.8% susceptible isolates. Among Salmonella isolates tested, 42.6%, 28.6%, and 14.3% were found to be relatively resistant to tetracycline, sulfamethoxazole-trimethoprim, and ampicillin, respectively, while 9.5%–19% were intermediately resistant to tetracycline, amoxicillin, ampicillin, cephalothin, and nitrofurantoin. Therefore, our findings provide the prevalence and drug resistance of Salmonella from foods of animal origin and contribute information to scientists as well as public health researchers to minimize the prevalent and resistant foodborne Salmonella species in Ethiopia.

  9. In vitro antimicrobial susceptibility of Staphylococcus aureus strains from dairy herds in KwaZulu-Natal. (United States)

    Schmidt, T


    Staphylococcus aureus is 1 of the most important causes of bovine mastitis and is responsible for significant economic losses to the dairy industry worldwide. One of the principal approaches used in treating intramammary infections is the administration of antimicrobials. Due to the propensity of S. aureus to develop resistance, antimicrobial susceptibility monitoring is necessary to ensure that treatment regimens are effective. As part of this investigation, 90 S. aureus strains isolated from mastitis cases submitted to Allerton Provincial Veterinary Laboratory during 2008 and 2009 were evaluated for their susceptibility to a panel of 10 antimicrobials. Only 8 of the 90 S. aureus isolates tested (8.9%) were found to be susceptible to all of the antimicrobials evaluated. A very high level of resistance to the beta-lactam antibiotics was noted: 47.8% of the isolates were resistant to penicillin and 65.6% were resistant to ampicillin. Minimal resistance to oxacillin, cephalothin and trimethoprim-sulfamethoxazole (1.1%) was found. Seventeen (18.9%) of the isolates tested were found to be resistant to 3 or more antimicrobials. The need for vigilant monitoring of bacterial resistance trends in the dairy industry is warranted as the potential public health implications are significant.

  10. Detection of Class I and II integrons for the assessment of antibiotic and multidrug resistance among Escherichia coli isolates from agricultural irrigation waters in Bulacan, Philippines. (United States)

    Paraoan, Cielo Emar M; Rivera, Windell L; Vital, Pierangeli G


    Contaminated irrigation water may greatly affect not only the quality of produce but also the people exposed to it. In this study, agricultural irrigation waters in Bulacan, Philippines were assessed and found to be contaminated with Escherichia coli (E. coli) ranging from 0.58 to 4.51 log10 CFU/mL. A total of 79 isolates of E. coli were confirmed through polymerase chain reaction (PCR) amplifying the uidA gene and were tested for phenotypic resistance using 10 antimicrobials through the Kirby-Bauer disc diffusion method. Forty-six isolates (58.22%) were noted to be multidrug resistant (MDR) with high resistance rate to cephalothin, tetracycline, streptomycin, ampicillin, trimethoprim, nalidixic acid, and chloramphenicol. Moreover, this study also examined the prevalence of Class I and II integrons accounting to 67.39% and 17.39%, respectively, of the MDR E. coli strains using multiplex PCR. The results imply that the agricultural water used in Bulacan is contaminated with the fecal material of man or other animals present in the area, and the presence of MDR bacteria, which pose a potential threat to individuals in these areas, is alarming. In addition, detection of integrons could be a good marker for the identification of MDR isolates. Lastly, this study could develop strategies for the proper management of farming sites leading to the detection of food-borne pathogens and prevention of infectious diseases.

  11. Genetic heterogeneity of Escherichia coli isolated from pasteurized milk in State of Paraná, Brazil

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    Karine Oltramari


    Full Text Available Food contamination caused by enteric pathogens is a major cause of diarrheal disease worldwide, resulting in high morbidity and mortality and significant economic losses. Bacteria are important agents of foodborne diseases, particularly diarrheagenic Escherichia coli. The present study assessed the genetic diversity and antimicrobial resistance of E. coli isolates from pasteurized milk processed in 21 dairies in northwestern State of Parana, Brazil. The 95 E. coli isolates were subjected to antimicrobial susceptibility testing according to the recommendations of the Clinical and Laboratory Standards Institute and assessed genotypically by Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR. The highest rate of resistance was observed for cephalothin (55.78%. ERIC-PCR revealed high genetic diversity, clustering the 95 bacterial isolates into 90 different genotypic patterns. These results showed a heterogeneous population of E. coli in milk samples produced in the northwestern region of Paraná and the need for good manufacturing practices throughout the processing of pasteurized milk to reduce the risk of foodborne illnesses.

  12. Ceftiofur sodium, a broad-spectrum cephalosporin: evaluation in vitro and in vivo in mice. (United States)

    Yancey, R J; Kinney, M L; Roberts, B J; Goodenough, K R; Hamel, J C; Ford, C W


    Ceftiofur sodium, a broad-spectrum beta-lactamase-resistant cephalosporin, was evaluated in vitro and in vivo in mice. Ceftiofur is the sodium salt of (6R, 7R)-7[( 2-amino-4-thiazolyl)-Z- (methoxyimino)acetyl]amino)-3-[( (2-furanylcarbonyl)thio]methyl)-8-oxo-5- thia-1-azabicyclo-[4.2.0]oct-2-ene-2-carboxylate. Minimal inhibitory concentration values were obtained with 264 strains representing 9 genera and 17 species of bacterial pathogens from cattle, swine, sheep, horses, poultry, dogs, cats, and human beings. Ceftiofur was more active than was ampicillin against all strains tested including beta-lactamase-producing organisms. In mice with systemic infections, ceftiofur was more active than or equivalent to ampicillin, cephalothin, cefamandole, cloxacillin, cefoperazone, or pirlimycin. These protection tests included infections with Escherichia coli, Haemophilus pleuropneumoniae, H somnus, Pasteurella haemolytica, P multocida, Salmonella typhimurium, or Staphylococcus aureus. In infant mice with E coli-induced lethal diarrhea and in mice with S aureus and E coli-induced mastitis, ceftiofur was comparable or more active than was ampicillin.

  13. The isolation and characterization of Campylobacter jejuni subsp. jejuni from domestic geese (Anser anser). (United States)

    Aydin, F; Atabay, H I; Akan, M


    The objectives of this study were to determine the presence of thermophilic Campylobacter spp. in free range domestic geese, and to characterize isolated strains using phenotyping criteria and SDS-PAGE of whole-cell proteins. Forty cloacal swabs from two different flocks of domestic geese were examined. All Camp. jejuni strains isolated from geese were biotyped using the Lior biotyping scheme. Twelve Camp. jejuni isolates were also tested for their susceptibility to 17 different antibacterial agents by a disc diffusion Fourteen of the isolates were also subjected to SDS-PAGE. All of the geese examined were found to harbour Camp. jejuni. Six geese carried more than one species of Campylobacter. All strains examined were susceptible to various antibiotics but resistant to penicillin G and cephalothin. Eleven strains (92%) were resistant to sodium cefuroxime, and eight (67%) were resistant to cloxacillin, ampicillin and colistin sulphate. Three strains (25%) were resistant to tetracycline, and one strain was resistant to sulfamethoxazole/trimethoprim and kanamycin. Nine strains were subtyped as Camp. jejuni subsp. jejuni biotype II and the remaining ones as biotype I. There were 96% and 100% similarities between all the strains examined by SDS-PAGE. This study showed that Camp. jejuni were common in the intestinal tract of domestic geese. Geese should be considered as potential reservoirs for human and animal campylobacteriosis. The antibiotic resistance data from this study also showed that fluoroquinolone resistance, which appears to be a problem in poultry isolates in some countries, is not yet a problem in these geese.

  14. Antibiotic Resistance of Gram Negatives isolates from loggerhead sea turtles (Caretta caretta) in the central Mediterranean Sea. (United States)

    Foti, M; Giacopello, C; Bottari, Teresa; Fisichella, V; Rinaldo, D; Mammina, C


    Previous studies on fish and marine mammals support the hypothesis that marine species harbor antibiotic resistance and therefore may serve as reservoirs for antibiotic-resistance genetic determinants. The aim of this study was to assess the resistance to antimicrobial agents of Gram negative strains isolated from loggerhead sea turtles (Carettacaretta). Oral and cloacal swabs from 19 live-stranded loggerhead sea turtles, with hooks fixed into the gut, were analyzed. The antimicrobial resistance of the isolates to 31 antibiotics was assessed using the disk-diffusion method. Conventional biochemical tests identified Citrobacter spp., Proteus spp., Enterobacter spp., Escherichia spp., Providencia spp., Morganella spp., Pantoea spp., Pseudomonas spp. and Shewanella spp. Highest prevalences of resistance was detected to carbenicillin (100%), cephalothin (92.6%), oxytetracycline (81.3%) and amoxicillin (77.8%). The isolates showing resistance to the widest range of antibiotics were identified as Citrobacterfreundii, Proteusvulgaris, Providenciarettgeri and Pseudomonasaeruginosa. In this study, antibiotic resistant bacteria reflect marine contamination by polluted effluents and C.caretta is considered a bioindicator which can be used as a monitor for pollution.

  15. Antimicrobial susceptibility of the pathogens of bacteraemia in the UK and Ireland 2001-2002: the BSAC Bacteraemia Resistance Surveillance Programme. (United States)

    Reynolds, Rosy; Potz, Nicola; Colman, Melissa; Williams, Andrea; Livermore, David; MacGowan, Alasdair


    To describe the current patterns of antimicrobial resistance in the major pathogens of bacteraemia in the UK and Ireland, to highlight any unexpected resistance patterns and to act as a reference baseline for future studies. In 2001 and 2002, 5092 blood culture isolates were collected by 29 laboratories distributed across the UK and Ireland. A single central laboratory re-identified the isolates and measured MICs by the BSAC agar dilution method. Oxacillin resistance was found in 42% of Staphylococcus aureus and 76% of coagulase-negative staphylococci. Streptococci were generally susceptible to beta-lactams, but tetracycline resistance was common (except in Streptococcus pneumoniae) and particularly common among group B isolates (82% resistant). Nine percent of S. pneumoniae had reduced susceptibility to penicillin (MICs 0.12-1 mg/L), but none required >/=2 mg/L for inhibition. High-level gentamicin resistance was seen in 43% of Enterococcus faecalis, often in combination with raised ciprofloxacin MICs (>/=32 mg/L), but these isolates remained susceptible to ampicillin and imipenem. Only linezolid and tigecycline showed in vitro potency against a large proportion of Enterococcus faecium. Vancomycin resistance was restricted to enterococci (20% of E. faecium, 3% of E. faecalis) and a single isolate of coagulase-negative staphylococci (0.2%, MIC of 8 mg/L). Escherichia coli isolates were commonly resistant to amoxicillin (56%) and tetracycline (88%) but remained susceptible to ceftazidime, piperacillin/tazobactam and imipenem. Extended-spectrum beta-lactamases were detected in 2% of E. coli (none in 2001, 3.2% in 2002), 5% of Klebsiella spp. and 8% of Enterobacter spp. Resistance rates of Pseudomonas aeruginosa to ciprofloxacin, ceftazidime, gentamicin, imipenem and piperacillin/tazobactam were between 4% and 7%. Among the newly licensed and developmental agents, there was no resistance to linezolid in Gram-positive organisms. Ertapenem had a wide spectrum, covering

  16. Inhibition of AmpC beta-lactamase through a destabilizing interaction in the active site

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    Trehan, I.; Beadle, B.M.; Shoichet, B.K. (NWU)


    {beta}-Lactamases hydrolyze {beta}-lactam antibiotics, including penicillins and cephalosporins; these enzymes are the most widespread resistance mechanism to these drugs and pose a growing threat to public health. {beta}-Lactams that contain a bulky 6(7){alpha} substituent, such as imipenem and moxalactam, actually inhibit serine {beta}-lactamases and are widely used for this reason. Although mutant serine {beta}-lactamases have arisen that hydrolyze {beta}-lactamase resistant {beta}-lactams (e.g., ceftazidime) or avoid mechanism-based inhibitors (e.g., clavulanate), mutant serine {beta}-lactamases have not yet arisen in the clinic with imipenemase or moxalactamase activity. Structural and thermodynamic studies suggest that the 6(7){alpha} substituents of these inhibitors form destabilizing contacts within the covalent adduct with the conserved Asn152 in class C {beta}-lactamases (Asn132 in class A {beta}-lactamases). This unfavorable interaction may be crucial to inhibition. To test this destabilization hypothesis, we replaced Asn152 with Ala in the class C {beta}-lactamase AmpC from Escherichia coli and examined the mutant enzyme's thermodynamic stability in complex with imipenem and moxalactam. Consistent with the hypothesis, the Asn152 {yields} Ala substitution relieved 0.44 and 1.10 kcal/mol of strain introduced by imipenem and moxalactam, respectively, relative to the wild-type complexes. However, the kinetic efficiency of AmpC N152A was reduced by 6300-fold relative to that of the wild-type enzyme. To further investigate the inhibitor's interaction with the mutant enzyme, the X-ray crystal structure of moxalactam in complex with N152A was determined to a resolution of 1.83 {angstrom}. Moxalactam in the mutant complex is significantly displaced from its orientation in the wild-type complex; however, moxalactam does not adopt an orientation that would restore competence for hydrolysis. Although Asn152 forces {beta}-lactams with 6(7){alpha

  17. High β-Lactamase Levels Change the Pharmacodynamics of β-Lactam Antibiotics in Pseudomonas aeruginosa Biofilms (United States)

    Ciofu, Oana; Yang, Liang; Wu, Hong; Song, Zhijun; Oliver, Antonio; Høiby, Niels


    Resistance to β-lactam antibiotics is a frequent problem in Pseudomonas aeruginosa lung infection of cystic fibrosis (CF) patients. This resistance is mainly due to the hyperproduction of chromosomally encoded β-lactamase and biofilm formation. The purpose of this study was to investigate the role of β-lactamase in the pharmacokinetics (PK) and pharmacodynamics (PD) of ceftazidime and imipenem on P. aeruginosa biofilms. P. aeruginosa PAO1 and its corresponding β-lactamase-overproducing mutant, PAΔDDh2Dh3, were used in this study. Biofilms of these two strains in flow chambers, microtiter plates, and on alginate beads were treated with different concentrations of ceftazidime and imipenem. The kinetics of antibiotics on the biofilms was investigated in vitro by time-kill methods. Time-dependent killing of ceftazidime was observed in PAO1 biofilms, but concentration-dependent killing activity of ceftazidime was observed for β-lactamase-overproducing biofilms of P. aeruginosa in all three models. Ceftazidime showed time-dependent killing on planktonic PAO1 and PAΔDDh2Dh3. This difference is probably due to the special distribution and accumulation in the biofilm matrix of β-lactamase, which can hydrolyze the β-lactam antibiotics. The PK/PD indices of the AUC/MBIC and Cmax/MBIC (AUC is the area under concentration-time curve, MBIC is the minimal biofilm-inhibitory concentration, and Cmax is the maximum concentration of drug in serum) are probably the best parameters to describe the effect of ceftazidime in β-lactamase-overproducing P. aeruginosa biofilms. Meanwhile, imipenem showed time-dependent killing on both PAO1 and PAΔDDh2Dh3 biofilms. An inoculum effect of β-lactams was found for both planktonic and biofilm P. aeruginosa cells. The inoculum effect of ceftazidime for the β-lactamase-overproducing mutant PAΔDDh2Dh3 biofilms was more obvious than for PAO1 biofilms, with a requirement of higher antibiotic concentration and a longer period of treatment

  18. Doripenem in hospital infections: a focus on nosocomial pneumonia, complicated intra-abdominal infections, and complicated urinary tract infections

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    Tze Shien Lo


    Full Text Available Tze Shien Lo,1 Stephanie M Borchardt,2 Justin M Welch,3 Melissa A Rohrich,3 Augusto M Alonto,4 Anne V Alonto51Infectious Diseases Service, Veterans Administration Medical Center, Fargo, North Dakota, USA; 2Research Service, Veterans Administration Medical Center, Fargo, North Dakota, USA; 3Pharmacy Service, Veterans Administration Medical Center, Fargo, North Dakota, USA; 4Infectious Diseases Department, MeritCare Medical Center, Fargo, North Dakota, USA; 5Department of Internal Medicine, University of North Dakota School of Medicine and Health Sciences, Fargo, North Dakota, USAAbstract: Doripenem is the latest carbapenem on the market to date. Although not an antibiotic in a new class, it offers a glimmer of hope in combating serious infections secondary to multidrug-resistant Gram-negative bacteria when we have not seen a new class of antibacterial, particularly for Gram-negative bacteria, for more than 10 years. In vitro, doripenem exhibits a broad spectrum of activity against Gram-positive and Gram-negative bacteria, including extended-spectrum β-lactamase (ESBL and Amp-C β-lactamase producing Enterobacteriaceae and anaerobes. Doripenem also exhibits better in vitro activity against Pseudomonas aeruginosa compared to other anti-pseudomonal carbapenems. It combines the desirable activities of both imipenem and meropenem. It has similar activity to imipenem against Gram-positive pathogens and has the antimicrobial spectrum of meropenem against Gram-negative organisms. Several randomized clinical trials have demonstrated that doripenem is non-inferior to meropenem, imipenem, piperacillin/tazobactam, or levofloxacin in its efficacy and safety profile in treating a wide range of serious bacterial infections including intra-abdominal infection, complicated urinary tract infection, and nosocomial pneumonia. Due to its wide spectrum of activity and good safety profile it is susceptible to misuse leading to increasing rates of resistance

  19. Extended spectrum beta-lactamase and metallo beta-lactamase production among Escherichia coli and Klebsiella pneumoniae isolated from different clinical samples in a tertiary care hospital in Kathmandu, Nepal. (United States)

    Nepal, Krishus; Pant, Narayan Dutt; Neupane, Bibhusan; Belbase, Ankit; Baidhya, Rikesh; Shrestha, Ram Krishna; Lekhak, Binod; Bhatta, Dwij Raj; Jha, Bharat


    Extended spectrum beta-lactamase (ESBL) and metallo beta-lactamase (MBL) production in Klebsiella pneumoniae and Escherichia coli are the commonest modes of drug resistance among these commonly isolated bacteria from clinical specimens. So the main purpose of our study was to determine the burden of ESBL and MBL production in E. coli and K. pneumoniae isolated from clinical samples. Further, the antimicrobial susceptibility patterns of E. coli and K. pneumoniae were also determined. A cross-sectional study was conducted at Om Hospital and Research Centre, Kathmandu, Nepal by using the E. coli and K. pneumoniae isolated from different clinical samples (urine, pus, body fluids, sputum, blood) from May 2015 to December 2015. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique. Extended spectrum beta-lactamase production was detected by combined disc method using ceftazidime and ceftazidime/clavulanic acid discs and cefotaxime and cefotaxime/clavulanic acid discs. Similarly, metallo beta-lactamase production was detected by combined disc assay using imipenem and imipenem/ethylenediaminetetracetate discs. Bacteria showing resistance to at least three different classes of antibiotics were considered multidrug resistant (MDR). Of total 1568 different clinical samples processed, 268 (17.1%) samples were culture positive. Among which, E. coli and K. pneumoniae were isolated from 138 (51.5%) and 39 (14.6%) samples respectively. Of the total isolates 61 (34.5%) were ESBL producers and 7 (4%) isolates were found to be MBL producers. High rates of ESBL production (35.9%) was noted among the clinical isolates from outpatients, however no MBL producing strains were isolated from outpatients. Among 138 E. coli and 39 K. pneumoniae, 73 (52.9%) E. coli and 23 (59%) K. pneumoniae were multidrug resistant. The lowest rates of resistance was seen toward imipenem followed by piperacillin/tazobactam, amikacin and cefoperazone/sulbactam. High rate of

  20. Disseminated Streptococcus anginosus Infection with Empyema Thoracis in a Patient with Sarcoma

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    Yu-Min Chuang


    Full Text Available Streptococcus anginosus is a member of the normal flora of the oral cavity and a pathogen of thoracic infection. However, disseminated infection that was identified from different body fluids at the same time has never been reported. We report a 52-year-old man with advanced pulmonary sarcoma who developed neutropenia, bronchopleural fistula and thoracic empyema after chemotherapy. Viridans group Streptococcus was isolated from both empyema and urine, which was confirmed as S. anginosus according to the biochemical reaction profiles and 16S rRNA gene sequencing results. The patient recovered uneventfully after tube drainage and treatment with imipenem. Disseminated S. anginosus infection should be considered as a possible pathogen in immunocompromised patients with empyema and can be rapidly identified by 16S rRNA gene sequencing.

  1. Five-year analysis of antimicrobial susceptibility of the Streptococcus milleri group. (United States)

    Limia, A; Jiménez, M L; Alarcón, T; López-Brea, M


    Susceptibility to 17 antibiotics was studied in 180 strains of the Streptococcus milleri group (88 Streptococcus anginosus, 63 Streptococcus constellatus, and 29 Streptococcus intermedius) isolated over a 5-year period. Minimum inhibitory concentrations of penicillin were in the intermediate range for 5.6% of the strains. Resistance to erythromycin and clindamycin was found in 17.1% and 16.6% of the isolates, respectively. A steady increase in the susceptibility to ciprofloxacin was observed over the study period. Imipenem was the most active beta-lactam agent tested. Glycopeptide antibiotics showed excellent activity. Only slight differences between the three species were found in terms of antibiotic susceptibility. Intermediate resistance to penicillin is appearing among the Streptococcus milleri group in our area; consequently, care must be taken when choosing a macrolide for the management of infections caused by these microorganisms.


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    Voyda Y. V


    Full Text Available High prevalence of drug-resistance among the isolates – representatives of normal microflora is set which does them the potential source of distribution of determinants of drug-resistance among population of this species and family species of bacteria of different taxonomical groups. The high sensitiveness of strains of E. coli to imipenem, gatifloxacin and amikacin is set, that determines their practical value as preparations of reserve for treatment of infections caused by strains with multidrug-resistance. It is found out the growth of resistance to fluoroquinolones and circulation of generous amount mildly proof strains to the nitroxolinum and derivatives of nitrofuran, which occupy a leading place in the charts of the empiric therapy of patients by the chronic infections of urinoexcretory ways.

  3. Development of resistance in Shigella flexneri isolates obtained in the past 20 years in eastern Romania. (United States)

    Poiata, A; Constantiniu, S; Buiuc, D


    Our study is focused on the antimicrobial activity for a number of 626 Shigella flexneri strains collected from epidemic outbreaks and hospitalised patients during 1976-1995 period, in Eastern Romania. The metodology used for determining the in vitro activity of the antimicrobials was that described by NCCLS. The agents which are currently used in therapy (ampicillin, tetracycline, chloramphenicol) are less active than the newer drugs (third generation cephalosporins, aztreonam, imipenem, ciprofloxacin) for which sensitivity ranged between 93-100% The associated resistance between ampicillin, tetracycline, chloramphenicol was demonstrated. Isolates with MIC values for ampicillin > 8 micrograms/ml are still sensitive to the modern beta-lactams. For ampicillin/sulbactam association, sensitivity decreases from 100% in 1990-1993 to 43% in 1994-1995.

  4. Shigella flexneri-induced vaginitis in a prepubertal children: description of a case

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    Antonella Restelli


    Full Text Available In prepuberal girls vulvo-vaginitis are caused by germs of intestinal origin,mycetes, Gardnerella vaginalis, protozoa. Shigella is an uncommon agent able to induce valvovaginitis in children. We report the case of a 7-year-old girl with chronic vulvo-vaginitis caused by S. flexneri. Antibiotic Susceptibility Testing revealed that S. flexnery was sensible to cefotaxime, amoxicillin, imipenem, ciprofloxacin, but resistant to amikacin, cefazolin, gentamycin, ampicillin and tetracycline. A treatment with ciprofloxacin brought to a rapid resolution of all symptoms. At the follows up at 3 and 6 months the patient did not report symptoms of infection or articular cartilage abnormality; microbiological evaluations were also negative. Even if it is a single case report and other clinical trial may be performed in order to validate this hypothesis,we speculate that in patient with vulvo-vaginal infection living in environment with low hygiene care, a carefully microbiological evaluation of uncommon agents may be performed.

  5. PER-8, a Novel Extended-Spectrum β-Lactamase PER Variant, from an Acinetobacter baumannii Clinical Isolate in Nepal. (United States)

    Tada, Tatsuya; Shrestha, Shovita; Shimada, Kayo; Ohara, Hiroshi; Sherchand, Jeevan B; Pokhrel, Bharat M; Kirikae, Teruo


    A novel PER-type extended-spectrum β-lactamase, PER-8, was identified in an Acinetobacter baumannii clinical isolate obtained in Nepal. The amino acid sequence of PER-8 has a substitution at position 39 (Gly to Glu) compared with that of PER-7. The kcat/Km ratio of PER-8 for aztreonam was lower than that of PER-7, while the kcat/Km ratio of PER-8 for imipenem was higher than that of PER-7. The genomic environment surrounding blaPER-8 was intI1 blaPSE-1qacEDI sulI ISCR1-blaPER-8gts sulI orfX on a 100-kb plasmid. Copyright © 2017 American Society for Microbiology.

  6. Identification of KPC-producing Klebsiella pneumoniae in clinical samples in Iran

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    fereshte sadat Hashemizadeh


    Results: In this study of 202 isolates of Klebsiella, 180 isolates (89.1% of K. pneumoniae and 22 isolates (10.9% of Klebsiella oxytoca were isolated from patients. More than 55% of isolates showed multiple-drug resistance and also above 40% resistance to imipeneme and meropeneme was recorded. The MIC of isolates which were resistant to carbapenemes was above 32µg/ml.The PCR results showed that 22 cases (11.9% of isolates had blakpc gene which most of them had been isolated from urine and blood samples of patients who were hospitalized in the ICU and pediatrics. Conclusion: Regarding the existence of blakpc gene in K. pneumoniae and possibility of transformation of these genes to the other bacteria, reconsideration in antibiotics consumption patterns and more attention to nosocomial infections control criteria are inevitable.

  7. Phenotypic detection of metallo-β-lactamases in Pseudomonas aeruginosa and Acinetobacter baumannii isolated from hospitalized patients in São Luis, State of Maranhão, Brazil

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    Roberto Morais Luz de Carvalho


    Full Text Available Introduction Acquired metallo-β-lactamases (MβL are emerging determinants of resistance in Pseudomonas aeruginosa and Acinetobacter baumannii. The objectives of this study were to phenotypically detect MβL in imipenem-resistant P. aeruginosa and A. baumannii, to investigate the association between MβL-positive strains and hospitals, and to compare the resistance profiles of MβL-producing and non-MβL-producing strains. Methods The approximation disk and combined disk assay methods were used in this study. Results A total of 18 (38.3% P. aeruginosa isolates and 1 (5.6% A. baumannii isolate tested positive for the presence of MβL. Conclusions These results demonstrate the need for strict surveillance and for the adoption of preventive measures to reduce the spread of infection and potential outbreaks of disease caused by MβL-producing microorganisms.

  8. Peritonitis caused by Bifidobacterium longum: case report and literature review. (United States)

    Tena, Daniel; Losa, Cristina; Medina, María José; Sáez-Nieto, Juan Antonio


    Bifidobacterium spp. rarely causes human infections. We report a case of a 42-year-old man with a history of pancolonic diverticulosis, who suffered a purulent peritonitis caused by Bifidobacterium longum secondary to intestinal perforation. Clinical outcome was good after urgent surgery and antibiotic treatment with imipenem and amoxicillin/clavulanic acid. Our case shows that Bifidobacterium spp. should be considered as a cause of peritonitis, especially in patients with risk of intestinal perforation. The review of the literature shows that these organisms can cause a wide spectrum of severe infections, especially in patients with underlying diseases. Infections caused by Bifidobacterium spp. may be overlooked or underreported since it may be considered normal microbiota. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Detection of bla KPC-2 in Proteus mirabilis in Brazil

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    Adriane Borges Cabral


    Full Text Available INTRODUCTION : Infections caused by Klebsiella pneumoniae carbapenemase (KPC-producing isolates pose a major worldwide public health problem today. METHODS : A carbapenem-resistant Proteus mirabilis clinical isolate was investigated for plasmid profiles and the occurrence of β-lactamase genes. RESULTS : The isolate exhibited resistance to ertapenem and imipenem and was susceptible to meropenem, polymyxin, and tigecycline. Five plasmids were identified in this isolate. DNA sequencing analysis revealed the presence of bla KPC-2 and bla TEM-1 genes. An additional PCR using plasmid DNA confirmed that bla KPC-2 was present in one of these plasmids. Conclusions: We report the detection of bla KPC-2 in P. mirabilis in Brazil for the first time. This finding highlights the continuous transfer of bla KPC between bacterial genera, which presents a serious challenge to the prevention of infection by multidrug-resistant bacteria.

  10. Pasteurella multocida bacterial meningitis caused by contact with pigs

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    C. López


    Full Text Available Pasteurella multocida belongs to the normal flora of the respiratory and digestive tract of many animals. Animal exposure is a considerable risk factor for Pasteurella infection. P. multocida is the most common cause of local infection after an animal bite but is an unusual cause of meningitis. We present a case of bacterial meningitis by P. multocida in a 37-year-old man who worked in a pig farm and was bitten by a pig. The patient had a defect located in the lamina cribosa and this lesion could be the gateway of the infection, although in this case the infection could also be acquired through the pig bite. The bacteria was identified as P. multocida with the biochemical test API 20E (bioMérieux. In agreement with findings in the literature, the strain was susceptible in vitro to penicillin, ampicillin, cefotaxime, ceftriaxone ciprofloxacin, levofloxacin, imipenem and tetracycline.

  11. Antimicrobial susceptibility pattern of Acinetobacter species isolated from infected wounds at a tertiary care hospital

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    Rosić Ivana


    Full Text Available Bacteria of the genus Acinetobacter, especially species Acinetobacter baumanii, is one of the most important causes of infection in immunocompromised patients in hospital. The aim of this study was to determine susceptibility of Acinetobacter species isolated from swabs of inflamed wounds to antibiotics. The study was conducted in several departments of the Clinical Centre 'Kragujevac' through retrospective analysis of 220 Acinetobacter species isolates from surgical wounds in 2011. The isolates of Acinetobaster species were mostly sensitive to ampicillin-sulbactam, colistin and tigecycline in all hospital departments that were surveyed. Only minority of the isolated Acinetobacter species were susceptible to cotrimoxazole, amikacin, imipenem and/or meropenem. Antibiotics with the highest in vitro efficacy against Acinetobacter species were ampicillinsulbactam, colistin and tigecycline. Highly resistant Acinetobacter species were more frequently isolated from patients in Intensive Care Unit.

  12. Cepas de Pseudomonas spp. produtoras de metalo-betalactamase isoladas no Hospital Geral de Fortaleza Metallo-betalactamase producing Pseudomonas spp. strains isolated in the Hospital Geral de Fortaleza

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    Júlio César Nogueira Torres


    Full Text Available Pseudomonas sp. é um bacilo gram-negativo ubíquo de vida livre e freqüente em ambientes hospitalares. Bactérias produtoras de metalo-betalactamases (MBLs são em grande parte resistentes aos betalactâmicos de largo espectro, incluindo cefalosporinas e carbapenens. Este trabalho objetivou detectar cepas de Pseudomonas spp. resistentes ao imipenem e à ceftazidima, assim como identificar aquelas produtoras de MBLs. Foram estudadas (entre junho de 2002 e junho de 2003 311 cepas isoladas de diversas amostras clínicas no Hospital Geral de Fortaleza (HGF, bem como foram realizados testes de identificação e sensibilidade pelo sistema de automação MicroScan®/WalkAway, sendo as cepas multirresistentes confirmadas através do método de difusão em disco. A triagem para detecção de amostras produtoras de MBLs foi realizada pelo método de dupla difusão, utilizando discos com mercaptoacetato de sódio. Entre essas amostras, 24 (7,71% demonstraram produção de MBLs e padrão de multirresistência entre as cepas estudadas. Os antimicrobianos para os quais as cepas apresentaram maior sensibilidade foram a piperacilina/tazobactam com 255 (82% de sensibilidade, seguido da piperacilina isoladamente, com 229 (73,63%; imipenem com 195 (62,70%; ticarcilina/ácido clavulânico com 193 (62,05%; e ceftazidima com 138 (44,37%. A detecção dessas amostras configura um problema emergente, com importantes implicações na terapêutica antimicrobiana.Pseudomonas sp. is a ubiquitous gram-negative bacilli, of free and frequent life in hospital environment. Metallo-betalactamases (MBLs productive bacteria are largely resistant to betalactamics of wide spectrum, including cephalosporin and carbapenem. The objective of this work was to detect Pseudomonas spp. strains resistant to imipenem and ceftazidime, as well as to identify the MBLs producer ones. It was studied 311 isolated strains from several clinical samples at Fortaleza General Hospital (FGH, from June

  13. Septic arthritis caused by Aspergillus fumigatus in an immunosuppressive patient: A case report and review of the literature

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    Tuba Dal


    Full Text Available Septic arthritis is a serious medical problem that causes rapidly chronic and irreversible joint damage when diagnosisand treatment are delayed. Although, the bacteria are the most frequent cause of septic arthritis, rarely fungi may beresponsible for this disease. We presented here a case of septic arthritis caused by Aspergillus fumigatus, developed ina 65 years-old-male patient with diabetes mellitus. The patient admitted to our hospital with complaints of pain, swelling,redness in the right knee and high fever, which are not exceeding despite using vancomycin and ceftriaxone for 18days. Imipenem was started to the patient in our hospital. At the end of 7 days because of no regression of patient’scomplaints, arthroscopic synovectomy and lavage were performed for the patient’s right knee. Aspergillus fumigatuswas isolated from the aspiration biopsy specimen that received during the surgical operation and patient was treatedwith voriconazole, successfully. J Microbiol Infect Dis 2012; 2(1: 29-32

  14. Questions about the use of antibiotics in acute pancreatitis

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    Assef Jose


    Full Text Available Abstract Background and objective The use of antibiotics in acute pancreatitis despite recent clinical trials remains controversial. The aim of this study is to review the latest clinical trials and guidelines about antibiotics in acute pancreatitis and determine its proper use. Methods Through a Medline search, we selected and analyzed pertinent randomized clinical trials and guidelines that evaluated the use of antibiotics in acute pancreatitis. We answered the most frequent questions about this topic. Results and conclusion Based on these clinical trials and guidelines, we conclude that the best treatment currently is the use of antibiotics in patients with severe acute pancreatitis with more than 30% of pancreatic necrosis. The best option for the treatment is Imipenem 3 × 500 mg/day i.v. for 14 days. Alternatively, Ciprofloxacin 2 × 400 mg/day i.v. associated with Metronidazole 3 × 500 mg for 14 days can also be considered as an option.

  15. Prevalence and antimicrobial resistance of Salmonella serotypes isolated from retail chicken meat and giblets in Iran. (United States)

    Sodagari, Hamid Reza; Mashak, Zohreh; Ghadimianazar, Amir


    Salmonella is one of the major foodborne pathogens responsible for outbreaks of foodborne illness in humans worldwide. A total of 560 samples of chicken meat and giblets were collected from retail markets for Salmonella identification, serotyping, and antimicrobial resistance testing. Salmonella was detected in 19.8% of samples. Among the five serotypes identified, S. Thompson was the predominant type (48.7%). High antimicrobial resistance rates were observed to nalidixic acid (92.8%), tetracycline (81%), trimethoprim (68.4%), sulfamethoxazole / trimethoprim (61.2%), streptomycin (56.7%), and kanamycin (36.9%). Although resistance to chloramphenicol (3.6%), amoxicillin-clavulanic acid (5.4%), and ampicillin (11.7%) was detected, none of the isolates were resistant to ceftazidime, ceftriaxone, cefotaxime, ciprofloxacin, colistin, gentamicin, nor imipenem. Restrictions on the irrational use of antibiotics in humans and animals are suggested for the reduction of resistant strains.

  16. Prevalência de resistência bacteriana nas infecções de ferida operatória em cirurgia arterial periférica Prevalence of bacterial resistance in surgical wound infections in peripheral arterial surgery

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    Eduardo Lichtenfels


    Full Text Available CONTEXTO: A infecção de sítio cirúrgico é uma complicação grave da cirurgia vascular periférica. O recente aparecimento de microorganismos resistentes e agressivos gera uma nova preocupação com relação ao manejo dessas infecções. OBJETIVO: Verificar a prevalência de resistência bacteriana, a epidemiologia, os possíveis fatores associados e o padrão de resistência nas infecções de ferida operatória das cirurgias arteriais periféricas. MÉTODOS: Estudo de prevalência, envolvendo 40 pacientes portadores de infecção da ferida operatória e submetidos à cirurgia de revascularização arterial periférica no período de janeiro de 2007 a maio de 2008. RESULTADOS: Participaram do estudo pacientes com média de idade de 64,2 anos, predominantemente do sexo masculino (70%. A prevalência geral de resistência bacteriana foi 72,5%, e de multirresistência, 60%. O microorganismo mais freqüentemente isolado foi o Staphylococcus aureus (40%, sendo 11 das 16 culturas (68,7% resistentes à oxacilina. As taxas de resistência aos principais antimicrobianos testados foram: ampicilina, 85,7%; cefalosporina, 76,9%; oxacilina, 65%; e ciprofloxacina, 62,5%. Não foi identificada resistência à vancomicina e ao imipenem. CONCLUSÕES: Os achados deste estudo sugerem que a resistência bacteriana é um problema atual e muito prevalente nas cirurgias arteriais periféricas. O Staphylococcus aureus segue sendo o principal patógeno envolvido, demonstrando altas taxas de resistência. A vancomicina e o imipenem seguem sendo as principais opções terapêuticas para esse tipo de infecção.BACKGROUND: Surgical wound infection is a severe complication of peripheral vascular surgery. The recent appearance of resistant and aggressive pathogens brings new concerns related to the management of these infections. OBJECTIVE: To verify the prevalence of bacterial resistance, epidemiology, possibly associated factors and resistance patterns in wound

  17. Prevalence and antibiotic susceptibility of Bacteroides fragilis group isolated from stool samples in North Lebanon

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    Mariam Yehya


    Full Text Available Fifty one strains of the Bacteroides fragilis group were isolated from 45 fecal samples. Classical phenotypic identification showed that 16 isolates were B. thetaiotaomicron, 12 B. uniformis, 9 B. eggerthii,7 B. vulgatus,3 B. caccae,2 Parabacteroides distasonis with 1 identified B. ovatus and 1 B. fragilis. The 51 strains were tested for susceptibility against 16 antimicrobial agents and the MICs for metronidazole were determined. The tests showed that imipenem, meropenem and chloram-phenicol were the most effective antibiotics (98%, 98% and 92.16% of susceptibility, respectively followed by ticarcillin/clavulanic acid, piperacillin/tazobactam, rifampin (88.24% susceptibility, moxifloxacin 86.27% and tigecycline 84.31%. Ofloxacin and cefotaxime were the least effective antibiotics with 27.45% and 0% of activity respectively. Only six of the 51 isolated strains were resistant to metronidazole with MICs = 64 mg/L (1 strain and > 256 mg/L (5 strains.


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    N. I. Gabrielan


    Full Text Available Antibiotic and fagosensitivity most etiologically important nosocomial strains of bacteria – Pseudomonas aeru- ginosa, Klebsiella pneumoniae, E. coli, Proteus spp., Staphylococcus spp. were studied. Multiple drug-resistant bacteria as gram-positive and gram-negative, isolated from 8 substrates, had been demonstrated. With regard to the sensitivity of Pseudomonas aeruginosa >40% was observed in 40–50% of the strains to aminoglycosides – aztreonam, amikacin, netilmicin, and only 23–25% of the strains – to gentamicin and levofloxacin (an average of antibiotic susceptibility was 27%. All strains of ESBL Klebsiella drew up and were sensitive only to imipenem, meropenem and aminoglycosides. Specific phages lysed 43–48% of the strains Pseudomonas aeruginosa and Klebsiella pneumoniae, E. coli, Pro- teus spp., multidrug resistant strains of Staphylococcus spp. It is proposed to introduce the use of phages in clinical practice. 

  19. Short communication: Multidrug-resistant Acinetobacter baumannii-calcoaceticus complex isolated from infant milk formula and utensils in a nursery in Rio de Janeiro, Brazil. (United States)

    Araújo, B C; Moraes, M S; Costa, L E O; Nascimento, J S


    Infant milk formulas are not sterile products, and pathogenic bacteria can survive and multiply in these products. This study was performed, initially, to detect the presence of Salmonella spp. in reconstituted infant milk formula and on utensils previously sanitized used in their preparation or distribution in a nursery of a public hospital in Rio de Janeiro. None of the samples tested carried Salmonellaspp. However, further identification of colonies growing on the selective media revealed the presence of several other gram-negative bacteria. Seventeen isolates were identified as belonging to Acinetobacter baumannii-calcoaceticus complex. Fourteen isolates presented a multidrug-resistance profile, by disc diffusion assays, and one of them--JE4--was also resistant to imipenem. The detection of Acinetobacter isolates in this work demonstrates inadequate hygiene practices in the preparation or distribution of infant milk formula. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  20. Mycobacterium abscessus Endocarditis: A Case Report and Literature Review

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    Wei-Chung Tsai


    Full Text Available Infective endocarditis owing to Mycobacterium abscessus infection is rarely reported. Most cases of infective endocarditis caused by Mycobacterium abscessus are seen in patients after valve replacement. Although early surgical intervention is recommended and medical treatment with antibiotics according to the susceptibility to the pathogen, such as amikacin, imipenem, cefoxitin, quinolones and macrolides, are applied, the course of such endocarditis is usually subacute and often has fatal outcomes. The present case was a 29-year-old male patient who was an intravenous drug user who had recurrent endocarditis caused by Mycobacterium abscessus. Unusually, our reported case was infected on his native valve. However, we experienced recurrence despite antimicrobial therapy. For culture-negative endocarditis, physicians should consider the possibility of Mycobacterium abscessus infection and related treatment difficulties.

  1. A Nosocomial Gram Negative Meningitis Caused By Acinetobacter SPP: Case Report

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    Taj ML Atri A


    Full Text Available The genus acinetobacter are intestinal gram negative, encapsulated, non motile, aerobic bacilli, which are rod shaped during rapid growth and cocobacillary in stationary phase. Risk factors associated with nosocomial infections include: length of hospital stay, surgery, wounds, previous infection, fecal colonization, treatment with broad spectrum antibiotics, parenteral nutrition, indwelling central intravenous or urinary catheters, admission to a burn unite or ICU and mechanical ventilation. Acinetobacter meningitis occur infrequently and is generally found after neuro¬surgical procedures."nHere, we are presenting a 19 year-old female patient who developed multi-drug resistant (MDR acinetobacter meningitis after operation on maxillary bone, but despite good clinical response to imipenem and amikacin succumbed aminoglycoside induced otoxicity.

  2. Biofilm production using distinct media and antimicrobial susceptibility profile of Pseudomonas aeruginosa

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    Leandro Reus Rodrigues Perez

    Full Text Available Biofilm production is an important mechanism for bacterial survival and its occurrence together with antimicrobial resistance represents a challenge for clinical management. Here, we evaluated the ability for biofilm production among P. aeruginosa isolates from patients with or without cystic fibrosis (CF using two distinct media, besides determining the antimicrobial susceptibility profile of these isolates for eight antimicrobial agents. The ability for biofilm production when TSB medium was used was higher than when used CF sputum media (p = 0.0198. However, P. aeruginosa isolates from CF have demonstrated similar performance for biofilm production, independently of the medium used. Besides, among the biofilm-producing isolates, those recovered from CF were more resistant to the carbapenems (meropenem and imipenem agents than those isolates from non-CF isolates.

  3. Resistencia a antibióticos de bacilos GRAM negativos aislados en unidades de cuidados intensivos: Análisis comparativo de dos periódos (1998-2001 Bacterial resistance to antibiotics in gram negative isolates from intensive care units: Comparative analysis between two periods (1998-2001

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    C. H. Rodriguez


    Full Text Available Se comparó la incidencia relativa de las diferentes especies de bacilos gram-negativos y la resistencia a varios antibacterianos, en dos muestras de aislamientos clínicos correspondientes a cinco meses del año 1998 y del mismo período del año 2001, con el objetivo de conocer la evolución de ambos, frecuencia de cada especie como agente etiológico, y resistencia a antimicrobianos. Para ello se analizaron en cada período 100 aislamientos de bacilos gram-negativos obtenidos de muestras clínicas de pacientes internados en salas de cuidados intensivos del Hospital de Clínicas José de San Martín. Se determinó la especie bacteriana y la concentración inhibitoria mínima de cada antibiótico. Acinetobacter spp. fue el microorganismo más aislado en ambos períodos. El porcentaje de aislamientos resistentes a imipenem fue del 60%, mientras que a ciprofloxacina y cefalosporinas de tercera generación fue superior al 80%. En Klebsiella pneumoniae el porcentaje de aislamientos resistentes a cefalosporinas de tercera generación disminuyó del 71.4 al 30% (pThe incidence and drug susceptibility of gram-negative isolates from clinical samples of patients from different intensive care units at the Hospital de Clinicas José de San Martín were analysed. Two hundred isolates during the same five months period, in two different years (1998 and 2001 were obtained and evaluated. Acinetobacter spp., was the most frequently isolated microorganism. Resistance to imipenem was observed in 60% of these isolations while resistance to 3rd generation cephalosporin and ciprofloxacin was observed in more than 80%. Klebsiella pneumoniae was not resistant to imipenem, the resistance to 3rd and 4rth generation cephalosporins decreased from 71.4 to 30% of isolates (p<0.05, while ciprofloxacin resistance increased from 5 to 20% (p<0.05. An increasing resistance to imipenem in Pseudomonas aeruginosa was noted, from 15.4 to 68% (p<0.05%; to ciprofloxacin, from 31.4 to

  4. Pasteurella multocida bacterial meningitis caused by contact with pigs. (United States)

    López, C; Sanchez-Rubio, P; Betrán, A; Terré, R


    Pasteurella multocida belongs to the normal flora of the respiratory and digestive tract of many animals. Animal exposure is a considerable risk factor for Pasteurella infection. P. multocida is the most common cause of local infection after an animal bite but is an unusual cause of meningitis. We present a case of bacterial meningitis by P. multocida in a 37-year-old man who worked in a pig farm and was bitten by a pig. The patient had a defect located in the lamina cribosa and this lesion could be the gateway of the infection, although in this case the infection could also be acquired through the pig bite. The bacteria was identified as P. multocida with the biochemical test API 20E (bioMérieux). In agreement with findings in the literature, the strain was susceptible in vitro to penicillin, ampicillin, cefotaxime, ceftriaxone ciprofloxacin, levofloxacin, imipenem and tetracycline.

  5. Prevalence of methicillin-resistant staphylococci isolated from different biological samples at Policlinico Umberto I of Rome: correlation with vancomycin susceptibility

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    Maria Teresa Mascellino


    Full Text Available The methicillin-resistance is increasing all over the world in the last decade. It is more frequent among coagulase-negative staphylococci (MRCoNS; infact the 52% of S. epidermidis strains results to be resistant to methicillin.The methicillin-resistant strains also show a reduced sensitivity towards the first-line agents such as glycopeptides and other antibiotics commonly used in therapy such as trimethoprim-sulphamethoxazole, imipenem, gentamycin, fosfomycin and chlarytromicin. Unlike MRSA (Methicillin-resistant S. aureus, MRCoNS resistance to glycopeptides generally concerns teicoplanin. Although vancomycin resistance is rare in Staphylococcus isolates, the detected shift towards higher values of MICs might affect patient’s clinical outcome.

  6. Fabrication, characterization and in vitro profile based interaction with eukaryotic and prokaryotic cells of alginate-chitosan-silica biocomposite. (United States)

    Balaure, Paul Catalin; Andronescu, Ecaterina; Grumezescu, Alexandru Mihai; Ficai, Anton; Huang, Keng-Shiang; Yang, Chih-Hui; Chifiriuc, Carmen Mariana; Lin, Yung-Sheng


    This work is focused on the fabrication of a new drug delivery system based on polyanionic matrix (e.g. sodium alginate), polycationic matrix (e.g. chitosan) and silica network. The FT-IR, SEM, DTA-TG, eukaryotic cell cycle and viability, and in vitro assay of the influence of the biocomposite on the efficacy of antibiotic drugs were investigated. The obtained results demonstrated the biocompatibility and the ability of the fabricated biocomposite to maintain or improve the efficacy of the following antibiotics: piperacillin-tazobactam, cefepime, piperacillin, imipenem, gentamicin, ceftazidime against Pseudomonas aeruginosa ATCC 27853 and cefazolin, cefaclor, cefuroxime, ceftriaxone, cefoxitin, trimethoprim/sulfamethoxazole against Escherichia coli ATCC 25922 reference strains. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. [Metalo-ß-lactamases in clinical isolates of Pseudomonas aeruginosa in Lima, Peru]. (United States)

    Gonzales-Escalante, Edgar; Vicente-Taboada, William; Champi-Merino, Roky; Soto-Pastrana, Javier; Flores-Paredes, Wilfredo; Lovera-García, Margarita; Chuquiray-Valverde, Nancy; Bejarano-Cristobal, Carlos; Puray-Chávez, Maritza; León-Sandoval, Segundo


    The aim of this study was to detect and characterize molecularly metallo-ß-lactamase (MßL) in clinical isolates of Pseudomonas aeruginosa. We carry out a cross sectional study in six publics hospital in Lima on August 2011. 51 isolates of P. aeruginosa resistant to ceftazidime and reduced susceptibility to carbapenemes were evaluated.The phenotypic assay was performed using the approximation method with substrate disks (ceftazidime, imipenem and meropenem) and ethylenediaminetetraacetic acid (EDTA). MßL gene detection was performed using the technique of polymerase chain reaction (PCR) multiplex. Through MßL detected phenotypic method in 15.7% of isolates. Detection of genes revealed the presence of the gene in the 8 isolates blaIMP. The first report of MßL in P. aeruginosa in Peru was described, this should alert the monitoring equipment in the institutions to promote control their spread.

  8. Emergence of co-trimoxazole resistant Nocardia brasiliensis causing fatal pneumonia. (United States)

    Khare, Vineeta; Gupta, Prashant; Himanshu, D; Kumar, Deepak


    An 85-year-old man was admitted to the medical intensive care unit with a 10-day history of severe breathlessness, fever and cough. The patient was known to have chronic obstructive pulmonary disease and had been receiving corticosteroids in the preceding 18 months. He had been treated for tuberculosis 2.5 years previously. On examination he was febrile, tachycardic with a respiratory rate of 46/min. Auscultation revealed bilateral crepitation's and wheeze. Chest radiograph revealed patchy infiltrates on right lung. The patient developed respiratory depression and was mechanically ventilated. His sputum and endotracheal aspirates revealed Nocardia brasiliensis on culture which was found to be co-trimoxazole resistant. Once this became known imipenem was substituted for co-trimoxazole but unfortunately condition of the patient did not improve and he died following a cardiac arrest.

  9. Clinical epidemiology of the global expansion of Klebsiella pneumoniae carbapenemases (United States)

    Munoz-Price, L Silvia; Poirel, Laurent; Bonomo, Robert A; Schwaber, Mitchell J; Daikos, George L; Cormican, Martin; Cornaglia, Giuseppe; Garau, Javier; Gniadkowski, Marek; Hayden, Mary K; Kumarasamy, Karthikeyan; Livermore, David M; Maya, Juan J; Nordmann, Patrice; Patel, Jean B; Paterson, David L; Pitout, Johann; Villegas, Maria Virginia; Wang, Hui; Woodford, Neil; Quinn, John P


    Klebsiella pneumoniae carbapenemases (KPCs) were originally identified in the USA in 1996. Since then, these versatile β-lactamases have spread internationally among Gram-negative bacteria, especially K pneumoniae, although their precise epidemiology is diverse across countries and regions. The mortality described among patients infected with organisms positive for KPC is high, perhaps as a result of the limited antibiotic options remaining (often colistin, tigecycline, or aminoglycosides). Triple drug combinations using colistin, tigecycline, and imipenem have recently been associated with improved survival among patients with bacteraemia. In this Review, we summarise the epidemiology of KPCs across continents, and discuss issues around detection, present antibiotic options and those in development, treatment outcome and mortality, and infection control. In view of the limitations of present treatments and the paucity of new drugs in the pipeline, infection control must be our primary defence for now. PMID:23969216

  10. Eight-Year Surveillance of Antimicrobial Resistance among Enterobacter Cloacae Isolated in the First Bethune Hospital (United States)

    Zhou, Qi; Zhang, Man; Wang, Ailin; Xu, Jiancheng; Yuan, Ye

    This study was to investigate the antimicrobial resistance of Enterobacter cloacae isolated in 8 consecutive years in the First Bethune Hospital. Disk diffusion test was used to study the antimicrobial resistance. The data were analyzed by WHONET 5 software according to Clinical and Laboratory Standards Institute (CLSI). Most of 683 strains of Enterobacter cloacae were collected from sputum 410 (60.0%), secretions and pus 105 (15.4%), urine 69 (10.1%) during the past 8 years. No Enterobacter cloacae was resistant to imipenem and meropenem in the First Bethune Hospital. The antimicrobial resistance of Enterobacter cloacae had increased in recent 8 years. The change of the antimicrobial resistance should be investigated in order to direct rational drug usage in the clinic and prevent bacterial strain of drug resistance from b eing transmitted.

  11. Primary brain abscess caused by Nocardia otitidiscaviarum. (United States)

    Ishihara, Masaki; Takada, Daikei; Sugimoto, Keiji; Oguro, Hiroaki; Gonoi, Tohru; Akiyama, Yasuhiko; Yamaguchi, Shuhei


    Diagnosing primary cerebral nocardiosis is difficult. This case report describes a 79-year-old immunocompetent Japanese woman with a primary brain abscess caused by Nocardia otitidiscaviarum (IFM 11321) and reviews the findings of 11 previous patients with N. otitidiscaviarum-induced brain abscesses. Four patients survived, including ours. Beta-lactams were not effective in our patient, and the diagnosis required a pathologic analysis of the surgical specimen. Sulfamethoxazole/trimethoprim (ST) was administered to the patient. On antibiotic susceptibility testing, N. otitidiscaviarum (IFM11321) was found to be resistant to amoxicillin-clavulanic acid, ceftriaxone, cefotaxime, cefepime, imipenem and clarithromycin, but sensitive to amikacin, gentamicin, ST and linezolid. Antimicrobial susceptibility patterns differ among Nocardia species, making species identification important for treatment. Patients with suspected Nocardia infection should therefore be treated empirically with ST and/or amikacin and considered for surgical management.

  12. Surveillance of antimicrobial resistance in Escherichia coli strains isolated from pigs at Spanish slaughterhouses. (United States)

    Teshager, T; Herrero, I A; Porrero, M C; Garde, J; Moreno, M A; Domínguez, L


    Antimicrobial resistance can make the efficient treatment of bacterial infections in humans and animals more difficult. Antimicrobial use in food animals may be one of the factors contributing to resistance. The Spanish surveillance network VAV has established a baseline of antimicrobial resistance in Escherichia coli strains from healthy pigs. Minimum inhibitory concentration and patterns of resistance to antimicrobials used in animals and humans were determined for 205 faecal strains isolated in a sampling frame of four slaughterhouses in Spain from 220 pigs in 1998. Higher levels of resistance were seen against antimicrobial agents authorised for use in food animals especially tetracycline, sulphonamides, trimethoprim and amoxycillin. All isolates were susceptible to antimicrobials employed mainly in humans such as ceftazidime, cefotaxime, imipenem, aztreonam and amikacin.

  13. Emergence of Serratia marcescens isolates possessing carbapenem-hydrolysing β-lactamase KPC-2 from China. (United States)

    Lin, X; Hu, Q; Zhang, R; Hu, Y; Xu, X; Lv, H


    Eighty-three carbapenem-resistant Serratia marcescens isolates were recovered from Zhejiang Provincial People's Hospital, China. The minimum inhibitory concentrations of imipenem, meropenem, and ertapenem for all isolates were 2 to >128 μg/mL. Polymerase chain reaction indicated that 63 S. marcescens isolates produced Klebsiella pneumoniae carbapenemase (KPC)-2. Clone A (15 isolates) and clone B (41 isolates) were the two dominant clones and clone A strains were gradually replaced by clone B strains between 2011 and 2014. The results indicate that blaKPC-2-positive S. marcescens emerged in our hospital as the major mechanism of carbapenem resistance. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  14. KPC-PRODUCING Serratia marcescens IN A HOME-CARE PATIENT FROM RECIFE, BRAZIL. (United States)

    Margate, Emmily; Magalhães, Vera; Fehlberg, Lorena Cristina Corrêa; Gales, Ana Cristina; Lopes, Ana Catarina Souza


    In this brief communication we describe the occurrence of a KPC-producing Serratia marcescens isolate in a home-care patient from Recife, Brazil. The blaKPC, blaSPM, blaIMP, blaVIM, blaOXA, blaCTX-M, blaSHV, blaTEM and blaGES genes were investigated by Polymerase Chain Reaction (PCR) and DNA sequencing. The isolate was positive for blaKPC-2 and blaTEM-1 and was resistant to aztreonam, cefepime, cefotaxime, imipenem, meropenem, gentamicin, ciprofloxacin and cefazidime, and susceptible only to amikacin, tigecycline and gatifloxacin. This is the first report in Brazil of KPC-producing S. marcescens clinical isolate outside of a hospital environment. Caregivers should be alert for the presence of this isolate in the community setting.

  15. A highly sensitive carbapenemase assay using laser desorption/ionization mass spectrometry based on a parylene-matrix chip. (United States)

    Park, Jong-Min; Kim, Jo-Il; Noh, Joo-Yoon; Kim, Mira; Kang, Min-Jung; Pyun, Jae-Chul


    A quantitative carbapenemase assay was developed using laser desorption/ionization mass spectrometry (LDI-MS) based on a parylene-matrix chip. As a first step, the reproducibility (spot-to-spot, shot-to-shot, and day-to-day) of LDI-MS based on a parylene-matrix chip and the quantification ranges for four carbapenem antibiotics (doripenem, ertapenem, imipenem, and meropenem) were determined. A carbapenem-susceptibility test was performed using the four carbapenems and 51 bacterial strains that displayed (1) carbapenem resistance with carbapenemase, (2) carbapenem resistance without carbapenemase, or (3) carbapenem susceptibility. The susceptibility test results showed that LDI-MS based on a parylene-matrix chip was more sensitive and selective for detecting the carbapenemase reaction than conventional MALDI-TOF MS based on a 2,5-dihydroxybenzoic acid matrix. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Klebsiella pneumoniae with multiple antimicrobial resistance

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    Caio Mendes

    Full Text Available A Klebsiella pneumoniae strain was isolated from the urine of a patient at one of the centers participating in the 2001 edition of the MYSTIC program in Brazil. The initial phenotypic findings of the isolated K. pneumoniae presented an unusual MIC of 8 mug/mL to meropenem, 2 mug/mL to imipenem, elevated MICs to broad spectrum cephalosporins (ceftazidime/cefotaxime/cefepime MIC > 256 mug/mL, aminoglycosides (gentamycin > 256 mug/mL and tobramycin = 48 mug/mL, piperacillin/tazobactam (MIC > 256 mug/mL and susceptibility to ciprofloxacin (MIC = 0.25 mug/mL. The strain also tested positive for ESBL production with double-disk and E-test methodologies. More detailed investigation revealed that the strain produced a SHV-4 type enzyme and also lacked a 36 kDa outer membrane porin.

  17. Outbreak of carbapenem-resistant Providencia rettgeri in a tertiary hospital

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    V S Tshisevhe


    Full Text Available The emergence of resistance to multiple antimicrobial agents in pathogenic bacteria is a significant public health threat, as there are limited effective antimicrobial agents for infections caused by multidrug-resistant (MDR bacteria. Several MDR bacteria are now frequently detected. Carbapenem resistance in Enterobacteriaceae is often plasmid mediated, necessitating stringent infection control practices. We describe an outbreak of carbapenem-resistant Providencia rettgeri involving 4 patients admitted to intensive care and high-care units at a tertiary hospital. Clinical and demographic characteristics of 4 patients with carbapenem-resistant P. rettgeri were documented. All P. rettgeri isolated in these cases had a carbapenem-resistant antibiogram, with resistance to imipenem, ertapenem and meropenem. These cases could be epidemiologically linked. A multiprong approach, simultaneously targeting antibiotic stewardship, universal precautions and appropriate transmission-based precaution practices, is integral to prevention and control of nosocomial infections.

  18. Un caso de melioidosis en la Argentina

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    Marisa Almuzara


    Full Text Available Se describe el caso de un varón de 17 años oriundo de República Dominicana, con antecedente de linfoma de Hodgkin, que presenta tumoraciones blandas con supuración espontánea. En sus cultivos desarrolló Burkholderia pseudomallei, agente etiológico de la melioidosis. El paciente recibió tratamiento antibiótico con imipenem y luego con amoxicilina-ácido clavulánico con muy buena evolución clínica del proceso infeccioso. En razón de la baja incidencia de Burkholderia pseudomallei en nuestro continente el diagnóstico de melioidosis pudo haber sido subestimado. Su diagnóstico definitivo depende del aislamiento e identificación del agente causal en la muestra clínica.

  19. Intra-pleural colistin methanesulfonate therapy for pleural infection caused by carbapenem-resistant Acinetobacter baumannii: a successful case report

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    Muhammad Asim Rana


    Full Text Available Infections caused by carbapenem-resistant, Gram-negative bacteria are an increasing clinical challenge, since the antimicrobial treatment options are often limited to colistin methanesulfonate. No data are available regarding the pharmacokinetics of colistin in pleural fluid. We report the case of a 92-year old man with ventilator-associated pneumonia and pleurisy caused by Acinetobacter baumannii and Escherichia coli, which were both multidrug-resistant. After an unsuccessful treatment with intravenous colistin methanesulfonate and imipenem-cilastatin, the addition of intra-pleural colistin methanesulfonate to the intravenous treatment led to a prompt clinical, radiological and microbiological resolution. This is the first report of a successful use of intra-pleural colistin in the literature. The intra-pleural colistin therapy should be considered in selected cases of pleurisy caused by multi-resistant Gram-negative bacteria.

  20. Susceptibility trends of Bacteroides fragilis group isolates from Buenos Aires, Argentina Tendencias en el perfil de sensibilidad de aislamientos del grupo Bacteroides fragilis obtenidos en Buenos Aires, Argentina

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    L. Fernández Canigia


    Full Text Available The aim of this study was to analyze the susceptibility trends to seven antibiotics of Bacteroides fragilis group isolates based on three survey studies performed by the Committee of Anaerobic Bacteria between 1989 and 2002. Fifty three, 82 and 65 B. fragilis group isolates were collected during each period. The antimicrobial agents included were: ampicillin, ampicillin-sulbactam (2:1, cefoxitin, piperacillin, imipenem, clindamycin, and metronidazole. Minimal inhibitory concentrations (MICs were determined according to the reference agar dilution method described by the Clinical and Laboratory Standards Institute (CLSI, formerly NCCLS. The most active antibiotics for B. fragilis and non- B. fragilis species throughout the three periods were: imipenem with 99.1 and 100% of activity, respectively, and metronidazole with 100% of activity. The susceptibility to ampicillin-sulbactam showed a decrease, from 100% to 90.3% and to 82.4 % in the last period, for both B. fragilis and non-B. fragilis species, respectively. The overall susceptibility rates for cefoxitin, piperacillin, and clindamycin were significantly different between B. fragilis and non-B. fragilis species (84.2% vs. 56.5%; 85.9% vs. 66.7% and 88.8% vs. 64.7%, respectively, pEl objetivo de este estudio fue evaluar las variaciones en el perfil de sensibilidad frente a siete antimicrobianos de aislamientos del grupo Bacteroides fragilis, mediante el análisis de tres relevamientos realizados por la Subcomisión de Bacterias Anaerobias de la Asociación Argentina de Microbiología (años 1989-1991, 1996-1998 y 1999-2002. En los citados períodos se recolectaron 53, 82 y 65 aislamientos del grupo B. fragilis. Se evaluó la actividad de: ampicilina, ampicilina-sulbactama (2:1, cefoxitina, piperacilina, imipenem, clindamicina y metronidazol. La concentración inhibitoria mínima (CIM se determinó utilizando el método de dilución en agar, según las normas del Clinical and Laboratory

  1. Purification and properties of a beta-lactamase from Alcaligenes dentrificans subsp. xylosoxydans. (United States)

    Fujii, T; Sato, K; Inoue, M; Mitsuhashi, S


    A penicillin beta-lactamase was purified from a strain of Alcaligenes dentrificans subsp. xylosoxydans resistant to beta-lactam antibiotics. The purified enzyme preparation gave a single protein band on polyacrylamide gel electrophoresis, and its molecular weight was 18,000 from sodium dodecylsulphate-acrylamide gel electrophoresis and gel filtration. Its isoelectric point was 9.8, the optimal pH was 8.5 and the optimal temperature was 35 degrees C. The enzyme hydrolyzed penicillin G and ampicillin more rapidly than cephalosporins. Relative rates, with penicillin G as 100, were: ampicillin, 102; carbenicillin, 15; cloxacillin, less than 1; piperacillin, 9; cephaloridine, 41; cefoperazone, 36; cefpiramide, 36 and cefmenoxime, 14. Clavulanic acid, sulbactam, imipenem, and cephamycins had low affinities for the enzyme. The enzyme activity was inhibited by iodine, Hg2+, clavulanic acid and sulbactam.

  2. Nosocomial bloodstream infections in a Turkish university hospital: study of Gram-negative bacilli and their sensitivity patterns. (United States)

    Köseoğlu, O; Kocagöz, S; Gür, D; Akova, M


    Treatment of nosocomial bacteraemia is usually governed by the surveillance results of the particular unit. Such results are especially important when antimicrobial resistance rates are high. Multiresistant isolates including Gram-negatives producing extended-spectrum beta-lactamases have been frequently reported in tertiary care units in Turkey. In this study, antimicrobial susceptibilities of Gram-negative blood isolates (n=348) were determined by microbroth dilution tests. The results showed carbapenems (meropenem and imipenem) to be uniformly more potent in vitro than any other drug against the Enterobacteriaceae. Quinolone antibiotics were more active in vitro than aminoglycosides against a range of bacteria. Gram-negative bloodstream isolates were highly resistant to many antimicrobial agents in the hospital. In order to prevent hospital infection and antimicrobial resistance, surveillance of aetiological agents must be performed regularly.

  3. Prevalence and antimicrobial susceptibility of extended-spectrum beta-lactamase producing urinary isolates of Escherichia coli in outpatients

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    Marković Tatjana


    Full Text Available Introduction. In Gram-negative bacteria, the production of beta-lactamases is the most important mechanism of resistance to beta-lactam antibiotics. In the Banja Luka region, there were no extensive researches on the prevalence and antimicrobial resistance of the extended-spectrum beta-lactamase (ESBL producing Escherichia coli (E. coli isolates. Objective. The aim of the present study was to determine the presence of ESBL producing E. coli isolates as the cause of the urinary tract infections in outpatients, the distribution of these ESBL isolates according to age and gender of patients and their susceptibility to antimicrobials. Methods. Urine specimens obtained from outpatients were cultured on chromogenic CPS-ID3 media. All plates showing significant (>105 cfu/ml growth of E. coli in pure culture were further processed. Antimicrobial susceptibility testing was performed on VITEK TWO Compact using AST-GN27 cards for testing Gram negative bacteria and detection of ESBL producers. Results. Out of 2,195 isolates, 177 (8.1% were ESBL producers. Ninety-two isolates were obtained from female patients (5% of E. coli isolated from women and 85 isolates from male patients (23% of E. coli isolated from men. High percentage of ESBL isolates was detected in the infant age group under one year (36.7% and in the age group over 60 years (28.8%. All ESBL isolates were susceptible to imipenem and resistant to ampicillin, piperacillin, cefazolin, cefotaxime, ceftazidime and cefepime. There was a significant resistance to amikacin (79.1%, gentamicin (76.8%, amoxicillin/clavulanate (54.8% and trimethoprim/sulphamethoxazole (45.8%. Resistance to nutrofurantoin was 13.6%. Conclusion. This study has demonstrated the presence of ESBL producing E. coli urinary isolates in outpatients, and their extensive susceptibility to imipenem and nitrofurantoin.

  4. In vitro activity of tigecycline and comparators against carbapenem-susceptible and resistant Acinetobacter baumannii clinical isolates in Italy

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    Carattoli Alessandra


    Full Text Available Abstract Background In a recent multi-centre Italian survey (2003–2004, conducted in 45 laboratories throughout Italy with the aim of monitoring microorganisms responsible for severe infections and their antibiotic resistance, Acinetobacter baumannii was isolated from various wards of 9 hospitals as one of the most frequent pathogens. One hundred and seven clinically significant strains of A. baumannii isolates were included in this study to determine the in vitro activity of tigecycline and comparator agents. Methods Tests for the susceptibility to antibiotics were performed by the broth microdilution method as recommended by CLSI guidelines. The following antibiotics were tested: aztreonam, piperacillin/tazobactam, ampicillin/sulbactam, ceftazidime, cefepime, imipenem, meropenem tetracycline, doxycycline, tigecycline, gentamicin, amikacin, ciprofloxacin, colistin, and trimethoprim/sulphametoxazole. The PCR assay was used to determine the presence of OXA, VIM, or IMP genes in the carbapenem resistant strains. Results A. baumannii showed widespread resistance to ceftazidime, ciprofloxacin and aztreonam in more than 90% of the strains; resistance to imipenem and meropenem was 50 and 59% respectively, amikacin and gentamicin were both active against about 30% of the strains and colistin about 99%, with only one strain resistant. By comparison with tetracyclines, tigecycline and doxycycline showed a higher activity. In particular, tigecycline showed a MIC90 value of 2 mg/L and our strains displayed a unimodal distribution of susceptibility being indistinctly active against carbapenem-susceptible and resistant strains, these latter possessed OXA-type variant enzymes. Conclusion In conclusion, tigecycline had a good activity against the MDR A. baumannii strains while maintaining the same MIC90 of 2 mg/L against the carbapenem-resistant strains.

  5. Formulation of carbapenems loaded gold nanoparticles to combat multi-antibiotic bacterial resistance: In vitro antibacterial study. (United States)

    Shaker, Mohamed A; Shaaban, Mona I


    Despite the fact that carbapenems (powerful β-lactams antibiotics) were able to fight serious infectious diseases, nowadays the spread of carbapenems-resistant bacteria is considered the main challenge in antibacterial therapy. In this study, we focused on evaluating the surface conjugation of carbapenems (imipenem and meropenem) with gold nanoparticles as a delivering strategy to specifically and safely maximize their therapeutic efficacy while destroying the developing resistance of the pathogens. Different particle size formulae (35, 70 and 200nm) were prepared by citrate reduction method. The prepared nanoparticles were functionalized with imipenem (Ipm) or meropenem (Mem) and physico-chemically characterized for loading efficiency, particle size, morphology, and in-vitro release. The antibacterial efficacy was also evaluated against carbapenems resistant Gram-negative bacteria isolated from infected human, through measuring the minimum inhibitory concentration and antibiotic kill test. All the obtained gold nanoparticles showed a distinct nano-size with loading efficiency up to 72% and 74% for Ipm and Mem, respectively. The conjugation and physico-chemical stability of the formulated carbapenems were confirmed by FTIR and X-RPD. Diffusion driven release behavior was observed for both Ipm and Mem from all of the loaded gold nanoparticles. For both Ipm and Mem, formula with 35nm diameter showed the most significant enhancement in antibacterial activity against all the selected isolates including Klebsiella pneumoniae, Proteus mirabilis and Acinteobacter baumanii. Ipm loaded Gold nanoparticles demonstrated decrease in the MIC of Ipm down to four folds, whereas, Mem loaded gold nanoparticles showed decrease in the MIC of Mem down to three folds on the tested bacterial isolates. Based on these results, the formulation of carbapenems-loaded gold nanoparticles demonstrated to be a promising nano-size delivery vehicle for improving the therapeutic activity and

  6. Avaliação fenotípica da enzima Klebsiella pneumoniae carbapenemase (KPC em Enterobacteriaceae de ambiente hospitalar Phenotypic research on Klebsiella pneumoniae carbapenemase (KPC enzyme in Enterobacteriaceae from hospitals

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    Rosabel Dienstmann


    Full Text Available INTRODUÇÃO E OBJETIVO: A resistência bacteriana é problema frequente e importante no ambiente nosocomial. Nesse contexto, várias bactérias apresentam habilidade de desenvolver mecanismos de resistência enzimáticos, destacando-se as Enterobacteriaceae. Nesta família de microrganismos, a produção de Klebsiella pneumoniae carbapenemase (KPC é um mecanismo emergente, o que justifica sua vigilância constante. MATERIAL E MÉTODO: Este trabalho pesquisou o fenótipo de KPC em 30 isolados clínicos de enterobactérias resistentes a cefalosporinas de terceira geração e sensibilidade diminuída a carbapenem oriundas de dois hospitais (em Porto Alegre e na Grande Porto Alegre, RS. Realizou-se discodifusão com imipenem, meropenem e ertapenem, e 14 cepas com halo INTRODUCTION AND OBJECTIVE: Bacterial resistance is a frequent and important problem in the nosocomial environment. In this context, several bacteria have the ability to develop mechanisms of enzymatic resistance, mainly Enterobacteriaceae. In this family of microorganisms, the production of Klebsiella pneumoniae carbapenemase (KPC is an emerging mechanism, which should be under constant observation. MATERIAL AND METHOD: This study investigated the phenotype of KPC in 30 clinical isolates of Enterobacteriaceae resistant to third generation cephalosporin and carbapenem from two hospitals (Porto Alegre city and Porto Alegre, RS. It was performed disk diffusion method with imipenem, meropenem and ertapenem. Additionally, 14 strains with halo < 22 mm for the last antimicrobial agent underwent modified Hodge test. RESULTS: No sample showed carbapenemase (Hodge negative. DISCUSSION: Despite the fact there was no carbapenemase, resistance to carbapenems is possibly attributed to the presence of beta-lactamases AmpC and/or ESBL associated with changes in the permeability of porin channels. CONCLUSION: Given the emerging nature of KPC, it is important to trace it in Enterobacteriaceae

  7. Phenotypic and genotypic characterization of Klebsiella pneumoniae strains with reduced susceptibiliy to carbapenems

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    Simone Ambretti


    Full Text Available Reduced susceptibility to carbapenems in Gram-negative pathogens is an emerging feature of the antibiotic-resistance phenomenom Reports about strains resistant to this class of antibiotics among Enterobacteriaceae, particularly in Klebsiella pneumoniae, are increasing.The aims of this study were to assess the incidence of Klebsiella pneumoniae with reduced susceptibility to carbapenems in Bologna area and to carry out the characterization of these strains.The study included isolates of K. pneumoniae that showed reduced susceptibility to carbapenems, as detected by an automated system (Vitek2, bioMérieux. Between January and May 2009, 26 strains were collected (mainly isolated from urinary samples.These isolates were tested for susceptibility to carbapenems by E-test, to define MIC values for meropenem and ertapenem. Moreover, to detect the production of metallo-beta lactamases (MBL and carbapenemases (KPC were respectively performed the Etest with imipenem and imipenem/EDTA (IPM-IPM/EDTA and the modified Hodge test. Susceptibility assays performed by E-test showed that 25/26 strains were susceptible to meropenem, while for ertapenem 20/26 strains resulted resistant.The modified Hodge test was positive for 1 strain, while all the isolates were negative to the IPM-IPM/EDTA E-test.These results show that, as recently reported, the majority of strains of K. pneumoniae exhibiting reduced susceptibility to carbapenems, especially to ertapenem, are characterized by the production of ESBLs, which likely is associated with the loss of porins. On the other side, one strain was found to produce KPC and this finding confirms that the diffusion of carbapenemases producing K. pneumoniae has also to be considered in this geographic area.

  8. Zinc ascorbate has superoxide dismutase-like activity and in vitro antimicrobial activity against Staphylococcus aureus and Escherichia coli

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    Iinuma K


    Full Text Available Katsuhiro Iinuma, Isami TsuboiBML General Laboratory, Kawagoe, Saitama, JapanBackground: Acne vulgaris is a common dermatological disease, and its pathogenesis is multifactorial.Objective: We examined whether the ascorbic acid derivative zinc ascorbate has superoxide dismutase (SOD-like activity. SOD is an enzyme that controls reactive oxygen species production. In addition, the in vitro antimicrobial activity of zinc ascorbate against the Gram-positive bacterium Staphylococcus aureus and the Gram-negative bacterium Escherichia coli was tested either alone or in combination with a variety of antimicrobial agents; their fractional inhibitory concentration index was determined using checkerboard tests.Methods: The SOD-like activity was measured in comparison with other ascorbic acid derivatives (ascorbic acid, magnesium ascorbyl phosphate, and sodium ascorbyl phosphate and zinc. The antimicrobial susceptibility of twelve strains each of S. aureus and E. coli isolated from patients with dermatological infections was tested, in comparison to a type strain of S. aureus and E. coli.Results: Zinc ascorbate had significant (P < 0.001 SOD-like activity compared with other ascorbic acid derivatives and zinc. Moreover, it showed antimicrobial activity against a type strain of S. aureus and E. coli, and its concentration (0.064% and 0.128% for S. aureus and E. coli, respectively was sufficiently lower than the normal dose (5% of other ascorbic acid derivatives. Furthermore, combinations of zinc ascorbate with clindamycin, erythromycin, and imipenem against S. aureus (average fractional inhibitory concentration, 0.59–0.90, and with imipenem against E. coli (average fractional inhibitory concentration, 0.64 isolated from patients with dermatological infections showed an additive effect.Conclusions: Our results provide novel evidence that zinc ascorbate may be effective for acne treatment.Keywords: superoxide dismutase, reactive oxygen species, antimicrobial

  9. Shorter Duration of Post-Operative Antibiotics for Cecal Ligation and Puncture Does Not Increase Inflammation or Mortality.

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    Kendra N Iskander

    Full Text Available Antimicrobial therapy for sepsis has beneficial effects, but prolonged use fosters emergence of resistant microorganisms, increases cost, and secondary infections. We tested whether 3 days versus 5 days of antibiotics in the murine model of cecal ligation and puncture (CLP negatively influences outcomes. Following CLP mice were randomized to receive the antibiotic imipenem-cilastatin (25mg/kg in dextrose 5% in Lactated Ringer's solution every 12 hours for either three or five days. Serial monitoring over 28 days included body weight, temperature, pulse oximetry, and facial vein sampling for hematological analysis and glucose. A separate group of mice were euthanized on post-CLP day 5 to measure cytokines and peritoneal bacterial counts. The first study examined no antimicrobial therapy and demonstrated that antibiotics significantly improved survival compared to fluids only (p = 0.004. We next tested imipenem-cilastatin therapy for 3 days versus 5 days. Body weight, temperature, glucose, and pulse oximetry measurements remained generally consistent between both groups as did the hematological profile. Pro-inflammatory plasma cytokines were comparable between both groups for IL-6, IL-1β, MIP-2 and anti-inflammatory cytokines IL-10, and TNF SRI. At 5 days post-CLP, i.e. 2 days after the termination of antibiotics in the 3 day group, there were no differences in the number of peritoneal bacteria. Importantly, shortening the course of antibiotics by 40% (from 5 days to 3 days did not decrease survival. Our results indicate that reducing the duration of broad-spectrum antibiotics in murine sepsis did not increase inflammation or mortality.

  10. High prevalence of extensively drug-resistant and metallo beta-lactamase-producing clinical Acinetobacter baumannii in Iran. (United States)

    Maspi, Hossein; Mahmoodzadeh Hosseini, Hamideh; Amin, Mohsen; Imani Fooladi, Abbas Ali


    Acinetobacter species particularly Acinetobacter baumannii (A. baumannii) have been widely reported as broad-spectrum antibiotic resistant pathogens. Expression of various types of metallo beta-lactamases (MBL), classified as Ambler class B, has been associated with carbapenem resistance. Here, we attempted to assess the frequency of extensively drug-resistant (XDR) and MBL-producing A. baumannii among clinical isolates. 86 clinical A. baumannii strains were collected from 2014 to 2015 and their susceptibility to meropenem (10 μg), imipenem (10 μg), azteronem (30 μg), pipracillin (100 μg) tazobactam (110 μg), tobramycin (10 μg), fosfomycin (200 μg), rifampicin (5 μg), colistin (10 μg), tigecycline (15 μg), sulbactam/ampicillin (10 μg + 10 μg) and polymixin B (300 U) was evaluated using disk diffusion method. The MBL-producing isolates were screened using combined disc diffusion method. Furthermore, the presence of blaVIM, blaIMP, blaSPM, blaGIM, blaSIM and blaNDM was detected by PCR. 34.9% of isolates were recovered from bronchoalveolar lavage (BAL). 81 (94.2%) and 62 (71.2%) isolates were multidrug resistance (MDR) and XDR, respectively. 44 (51.2%) and 65 (75.6%) isolates were MBL-producing strains with resistance to imipenem and meropenem, respectively. 2 (2.3%), 13 (15.1%), 2 (2.3%), 4 (4.7%) and 2 (2.3%) isolates carried blaVIM, blaIMP, blaSPM, blaGIM and blaSIM genes, respectively. Our data showed that the rate of XDR and MBL A. baumannii is on the rise. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Crystallographic Studies of Two Bacterial AntibioticResistance Enzymes: Aminoglycoside Phosphotransferase (2')-Ic and GES-1\\beta-lactamase

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    Brynes, Laura; /Rensselaer Poly.


    Guiana Extended-Spectrum-1 (GES-1) and Aminoglycoside phosphotransferase (2')-Ic (APH(2')-Ic) are two bacteria-produced enzymes that essentially perform the same task: they provide resistance to an array of antibiotics. Both enzymes are part of a growing resistance problem in the medical world. In order to overcome the ever-growing arsenal of antibiotic-resistance enzymes, it is necessary to understand the molecular basis of their action. Accurate structures of these proteins have become an invaluable tool to do this. Using protein crystallography techniques and X-ray diffraction, the protein structure of GES-1 bound to imipenem (an inhibitor) has been solved. Also, APH(2')-Ic has been successfully crystallized, but its structure was unable to be solved using molecular replacement using APH(2')-Ib as a search model. The structure of GES-1, with bound imipenem was solved to a resolution of 1.89A, and though the inhibitor is bound with only moderate occupancy, the structure shows crucial interactions inside the active site that render the enzyme unable to complete the hydrolysis of the {beta}-lactam ring. The APH(2')-Ic dataset could not be matched to the model, APH(2')-Ib, with which it shares 25% sequence identity. The structural information gained from GES-1, and future studies using isomorphous replacement to solve the APH(2')-Ic structure can aid directly to the creation of novel drugs to combat both of these classes of resistance enzymes.

  12. Molecular detection of six virulence genes in Pseudomonas aeruginosa isolates detected in children with urinary tract infection. (United States)

    Badamchi, Ali; Masoumi, Hossein; Javadinia, Shima; Asgarian, Ramin; Tabatabaee, Azardokht


    Although a vast majority of Urinary tract infections (UTIs) are caused by E. coli, epidemiological reports have indicated an increasing rate of such infections caused by some other opportunistic organisms including Pseudomonas aeruginosa. Antimicrobial susceptibility and pathogenesis mechanisms of P. aeruginosa are poorly understood. The aim of this study was to detect some virulence factor genes and antimicrobial susceptibility patterns of P. aeruginosa isolates detected in patients with UTI, in children hospital of Tehran, Tehran, Iran. Eighty-four Pseudomonas aeruginosa were isolated. Then, the presence of six virulence genes, in the genome of the isolates was evaluated using PCR amplifications techniques. Finally, antimicrobial susceptibility pattern of the isolates was determined by disk diffusion method. According to the results, lasB was the most prevalent virulence gene that could be detected in the P. aeruginosa isolates (92.9%) used in this study. This was followed by aprA (81.2%), toxA (69.4%), and algD (60%) genes. Two genes, plcH and plcN, were detected in about 38.8% of the isolates. Additionally, Imipenem was found as the most active agent against the P. aeruginosa isolates used in this research. However, Cefotaxime resistance was observed in most of the isolates. Our P. aeruginosa isolates exhibited a great degree of heterogeneity not only in their virulence genes but also in their antimicrobial susceptibility profiles. Imipenem therapies tend to be among the best choices in the management of UTI caused by P. aeruginosa. As a conclusion, assessment of antimicrobial susceptibility pattern and also analyzing the virulence factors can be highly helpful to develop effective treatment strategies against P. aeruginosa urinary infections. Copyright © 2017. Published by Elsevier Ltd.

  13. Susceptibilidad a betalactámicos y resistencia por betalactamasas de espectro extendido (BLEE en Enterobacteriaceae aisladas de reservorios ambientales de un hospital general en Cajamarca, Perú.*

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    Marco Rivera-Jacinto


    Full Text Available Objetivos: Identificar enterobacterias en reservorios intrahospitalarios, evaluar su sensibilidad a betalactámicos y determinar su capacidad de producir betalactamasas de espectro extendido (BLEE, en el Hospital Regional de Cajamarca. Material y métodos: Se obtuvieron muestras mediante hisopado de grifos, lavatorios, mesas, camas y tablillas de historia clínica en las áreas de cirugía y pediatría; se recuperaron, aislaron e identificaron 45 cultivos de importancia clínica: 14 Enterobacter cloacae, 11 Escherichia coli, 5 Citrobacter freundii, 4 Klebsiella pneumoniae y 11 de otros géneros. Se determinó la sensibilidad antimicrobiana a los antibióticos betalactámicos: ampicilina, cefalotina, cefoxitina, ceftazidima, cefotaxima, ceftriaxona, amoxicilina-clavulanato, aztreonam e imipenem. Teniendo en cuenta los diámetros críticos de tamizaje, se realizó el test confirmatorio para BLEE. Para el análisis estadístico se utilizó el programa estadístico SPSS v15. Resultados: De los 45 cultivos aislados 34 fueron resistentes a ampicilina, 34 a cefalotina, 14 a cefoxitina, 12 a cefotaxima, 11 a ceftriaxona, 5 a ceftazidima, 19 a amoxicilina-clavulanato y 15 a aztreonam. Doce cultivos presentaron resistencia por BLEE a cefalosporinas de tercera generación y/o monobactámicos, cuatro E. coli y cuatro E. cloacae fueron los más relevantes. Todos fueron sensibles a imipenem. Conclusiones: Dada la capacidad de algunos de estos cultivos de producir BLEE existe el riesgo de brotes intrahospitalarios que pueden complicarse cuando son originados por microorganismos multirresistentes. La producción de BLEE como mecanismo de resistencia en los cultivos hallados debe ser motivo de preocupación por las implicancias que tiene.(Rev Med Hered 2011;22:69-75.

  14. Expanding the Repertoire of Carbapenem-Hydrolyzing Metallo-ß-Lactamases by Functional Metagenomic Analysis of Soil Microbiota (United States)

    Gudeta, Dereje D.; Bortolaia, Valeria; Pollini, Simona; Docquier, Jean-Denis; Rossolini, Gian M.; Amos, Gregory C. A.; Wellington, Elizabeth M. H.; Guardabassi, Luca


    Carbapenemases are bacterial enzymes that hydrolyze carbapenems, a group of last-resort β-lactam antibiotics used for treatment of severe bacterial infections. They belong to three β-lactamase classes based amino acid sequence (A, B, and D). The aim of this study was to elucidate occurrence, diversity and functionality of carbapenemase-encoding genes in soil microbiota by functional metagenomics. Ten plasmid libraries were generated by cloning metagenomic DNA from agricultural (n = 6) and grassland (n = 4) soil into Escherichia coli. The libraries were cultured on amoxicillin-containing agar and up to 100 colonies per library were screened for carbapenemase production by CarbaNP test. Presumptive carbapenemases were characterized with regard to DNA sequence, minimum inhibitory concentration (MIC) of β-lactams, and imipenem hydrolysis. Nine distinct class B carbapenemases, also known as metallo-beta-lactamases (MBLs), were identified in six soil samples, including two subclass B1 (GRD23-1 and SPN79-1) and seven subclass B3 (CRD3-1, PEDO-1, GRD33-1, ESP-2, ALG6-1, ALG11-1, and DHT2-1). Except PEDO-1 and ESP-2, these enzymes were distantly related to any previously described MBLs (33 to 59% identity). RAIphy analysis indicated that six enzymes (CRD3-1, GRD23-1, DHT2-1, SPN79-1, ALG6-1, and ALG11-1) originated from Proteobacteria, two (PEDO-1 and ESP-2) from Bacteroidetes and one (GRD33-1) from Gemmatimonadetes. All MBLs detected in soil microbiota were functional when expressed in E. coli, resulting in detectable imipenem-hydrolyzing activity and significantly increased MICs of clinically relevant ß-lactams. Interestingly, the MBLs yielded by functional metagenomics generally differed from those detected in the same soil samples by antibiotic selective culture, showing that the two approaches targeted different subpopulations in soil microbiota. PMID:28082950

  15. [A case of probable bacterial translocation-associated sepsis in healthy adult]. (United States)

    Ohosone, Yasuo; Obana, Mitsuo; Koido, Norihiko; Akizuki, Satoshi; Matsuoka, Yasuo; Kobayashi, Yoshio


    We report a patient with bacterial translocation-associated sepsis who was healthy and did not have any related-background. The 57-year-old male had been well until 16 hours before admission, when nausea and vomiting gradually developed and increased in intensity. In the morning of May 22, 2002, he had shaking chills, temperature of 38.6 degrees C and watery diarrhea, and was admitted to Kawasaki Municipal Hospital. On admission, temperature was 40.7 degrees C but otherwise physical examination revealed no particular abnormality. Laboratory data showed total white blood cells of 28,400/microliter, platelet count of 130,000/microliter, creatinine of 2.0 mg/dl and C-reactive protein of 7.5 mg/dl. 1 g of cefmetazole was administered every eight hours. In the early morning of May 23, he suddenly went into shock. At that time, laboratory findings revealed total white blood cells of 33,700/microliter, platelet count of 65,000/microliter, C-reactive protein of 24.9 mg/dl, creatinine of 5.6 mg/dl and serum potassium concentration of 5.7 mEq/l. Gram positive cocci and gram negative rods were isolated from blood culture obtained on admission. Cefmetazole was changed to 1.5 g/day of imipenem/cilastatin sodium and 600 mg/day of clindamycin. In addition, hemodialysis and endotoxin removal with an adsorbent column using polymyxin B were performed. Bacteria detected in the blood on admission were identified as Klebsiela oxytoca and Enterococcus faecium. Imipenem/cilastatin sodium and clindamycin were continued for 13 days. The patient recovered fully and was discharged on June 11. This case suggests that bacterial translocation-associated sepsis might occur even in a hitherto healthy adult.

  16. Species distribution and antimicrobial susceptibility of gram-negative aerobic bacteria in hospitalized cancer patients

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    El-Sharif Amany


    Full Text Available Abstract Background Nosocomial infections pose significant threats to hospitalized patients, especially the immunocompromised ones, such as cancer patients. Methods This study examined the microbial spectrum of gram-negative bacteria in various infection sites in patients with leukemia and solid tumors. The antimicrobial resistance patterns of the isolated bacteria were studied. Results The most frequently isolated gram-negative bacteria were Klebsiella pneumonia (31.2% followed by Escherichia coli (22.2%. We report the isolation and identification of a number of less-frequent gram negative bacteria (Chromobacterium violacum, Burkholderia cepacia, Kluyvera ascorbata, Stenotrophomonas maltophilia, Yersinia pseudotuberculosis, and Salmonella arizona. Most of the gram-negative isolates from Respiratory Tract Infections (RTI, Gastro-intestinal Tract Infections (GITI, Urinary Tract Infections (UTI, and Bloodstream Infections (BSI were obtained from leukemic patients. All gram-negative isolates from Skin Infections (SI were obtained from solid-tumor patients. In both leukemic and solid-tumor patients, gram-negative bacteria causing UTI were mainly Escherichia coli and Klebsiella pneumoniae, while gram-negative bacteria causing RTI were mainly Klebsiella pneumoniae. Escherichia coli was the main gram-negative pathogen causing BSI in solid-tumor patients and GITI in leukemic patients. Isolates of Escherichia coli, Klebsiella, Enterobacter, Pseudomonas, and Acinetobacter species were resistant to most antibiotics tested. There was significant imipenem -resistance in Acinetobacter (40.9%, Pseudomonas (40%, and Enterobacter (22.2% species, and noticeable imipinem-resistance in Klebsiella (13.9% and Escherichia coli (8%. Conclusion This is the first study to report the evolution of imipenem-resistant gram-negative strains in Egypt. Mortality rates were higher in cancer patients with nosocomial Pseudomonas infections than any other bacterial infections

  17. In vitro antimicrobial synergy of colistin with rifampicin and carbapenems against colistin-resistant Acinetobacter baumannii clinical isolates. (United States)

    Hong, Duck Jin; Kim, Jung Ok; Lee, Hyukmin; Yoon, Eun-Jeong; Jeong, Seok Hoon; Yong, Dongeun; Lee, Kyungwon


    Increased use of colistin in a clinical setting had resulted in the emergence of colistin-resistant (CoR) Acinetobacter baumannii. Combination therapy has been studied as a new approach to treat infections caused by A. baumannii. Here, we investigated the in vitro antimicrobial synergistic activities of several antimicrobial agent combinations against CoR A. baumannii. A total of 41 non-duplicate clinical isolates of CoR A. baumannii from a tertiary care hospital in Korea were prospectively collected from April 2012 to December 2014. As a control group, 41 carbapenem-resistant but colistin-susceptible (CoS) A. baumannii strains were also evaluated. Minimum inhibitory concentrations (MICs) of antimicrobial agents were determined by Etest in triplicate, and in vitro synergy tests were performed by the Etest MIC:MIC ratio method. Synergistic activity was determined as the sum of each antimicrobial agent's fractional inhibitory concentration evaluated (ΣFIC): synergy, ≤0.5; indifference, >0.5-4; and antagonism, >4. Synergistic activities were more frequently observed in the CoR group than the CoS group for combinations of colistin-rifampicin (80.5% vs. 14.6%, Pcolistin-meropenem (85.4% vs. 4.9%, Pcolistin-imipenem (46.3% vs. 2.4%, Pcolistin MICs against CoR A. baumannii clinical isolates to the susceptible range (≤ 2 μg/mL) more frequently (61.0%, 25/41, both) than combination with imipenem (29.3%, 12/41). Clinical trials are needed to prove the in vivo efficacy of those antimicrobial combinations that exhibited significant in vitro antimicrobial synergistic effects against CoR A. baumannii. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Current Microbial Isolates from Wound Swab and Their Susceptibility Pattern in a Private Medical College Hospital in Dhaka city

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    Shahin Sultana


    Full Text Available Background: Wound infection is one of the major health problems that are caused and aggravated by the invasion of pathogenic organisms where empiric treatment is routine. Objective: To isolate and identify the bacteria causing wound infection and to determine the antimicrobial susceptibility pattern. Materials and method: A total of 263 wound swab and pus samples were collected during the period of January to December 2012 from Delta Medical College and Hospital, Dhaka, Bangladesh. Swabs from the wound were inoculated on appropriate media and cultured and the isolates were identified by standard procedures as needed. Antimicrobial susceptibility testing was performed by disk diffusion method according to ‘The Clinical Laboratory Standard Institute’ guidelines. Results: In this study 220 bacterial isolates were recovered from 263 samples showing an isolation rate of 83.65%. The predominant bacteria isolated from infected wounds were Staphylococcus aureus 89 (40.45% followed by Escherichia coli 62 (28.18%, Pseudomonas aeruginosa 34 (15.45%, Enterococci 18 (8.18%, Acinetobacter 5 (2.27%, Klebsiella 9 (4.09% and Proteus 3 (3.36%. Staphylococcus aureus was sensitive to linezolid (94.38%, fusidic acid (91.01%, vancomycin (87.64%, amikacin (74.15% and gentamicin (73.03%. Among the Gram negative isolates Escherichia coli was predominant and showed sensitivity to imipenem (93.54% amikacin (83.87% colistin (53.22% and piperacillin and tazobactum (53.22% and pseudomonas showed sensitivity to amikacin (73.52%, imipenem (70.58% and colistin (70.58%. Conclusion: Staphylococcus aureus was the most frequently isolated pathogen from wound swab and the antibiotic sensitivity pattern of various isolates help to assist the clinician in appropriate selection of empirical antibiotics against wound infection.

  19. Characterization of Acinetobacter baumannii clinical isolates carrying bla(OXA-23) carbapenemase and 16S rRNA methylase armA genes in Yemen. (United States)

    Bakour, Sofiane; Alsharapy, Samer Ahmed; Touati, Abdelaziz; Rolain, Jean-Marc


    The aim of this study was to investigate the molecular support of resistance to carbapenems, aminoglycosides, and fluoroquinolones in Acinetobacter baumannii clinical isolates collected from Yemen hospital. Three A. baumannii were isolated in February 2013 from three patients hospitalized at Al-Thawra University Hospital in Sana'a, Yemen. Antibiotic susceptibility testing was performed using the disk diffusion and E-test methods. Carbapenemase production was carried out by the modified Hodge test (MHT) and imipenem-ethylenediaminetetraacetic acid (EDTA) methods. Carbapenem, aminoglycoside, and fluoroquinolone resistance determinants were studied by polymerase chain reaction and sequencing. The epidemiological relatedness of the three strains was studied using multilocus sequence typing (MLST). The isolates were resistant to almost all antibiotics tested with very high imipenem, amikacin, and ciprofloxacin minimum inhibitory concentrations (>32, >256, and >32 mg/L, respectively). The microbiological tests showed that the three A. baumannii were MHT positive, besides, the activity of β-lactamases was not inhibited by EDTA. All the three isolates contained the naturally occurring bla(OXA-51)-like gene and the bla(OXA-23)-like carbapenemase-encoding gene. The 16S rRNA methylase armA gene was detected in the three isolates. In addition, screening for genes encoding the aminoglycoside-modifying enzymes (AMEs) demonstrated that one isolate contained the acetyltransferase gene aac(6')-Ib. Fluoroquinolone resistance was associated with a single mutation Ser83Leu in the quinolone resistance determining region of the gyrA gene in all isolates. The MLST showed that the sequence type (ST) obtained corresponds to ST2 for the three strains. Here we report the first identification of multidrug-resistant A. baumannii isolates harboring the bla(OXA-23)-like gene, AMEs [aac(6')-Ib], and the 16S rRNA methylase (armA) in the Yemen hospital.

  20. Successful Ultrasound-Guided Percutaneous Drainage of Multiple Splenic Abscesses in a Kidney Transplant Patient With Encapsulated Sclerosing Peritonitis: A Case Report. (United States)

    Tuğcu, M; Ruhi, Ç; Boynueğri, B; Kasapoğlu, U; Can, Ö; Kiliçoğlu, G; Şahin, G; Titiz, M


    Differential diagnosis of post-transplant infections should include rare/uncommon foci and pathogens. We present a rare case of life-threatening infection, a splenic abscess in a 53-year-old woman who was transplanted with a cadaveric kidney 5 months previously. The patient was admitted to our clinic with chills, shivering, and fever. She required a kidney transplant because of end-stage renal disease secondary to systemic lupus erythematosus, which had previously been treated by means of peritoneal dialysis for 7 years, until encapsulated sclerosing peritonitis developed, at which time therapy was changed to hemodialysis for 1 year. On physical examination, the patient was slightly lethargic and had tenderness in the left upper quadrant of the abdomen. Laboratory evaluation revealed leukocytosis and high acute phase reactant. Abdominal ultrasonography (US) revealed multiple abscesses in the spleen, but splenectomy was not recommended because of her history of sclerosing peritonitis. Percutaneous drainage catheters were placed under US guidance. Culture of blood and fluid drained from the abscess revealed imipenem-sensitive Escherichia coli and Klebsiella spp. Imipenem (500 mg IV q6hr) was initiated, and the drainage volume was 40 to 50 mL/day in the first week and gradually decreased through the third week. The abscess was completely drained over a period of 6 weeks, as confirmed by computed tomography; percutaneous catheters were then removed. Although splenic abscesses are life-threatening, especially for immunocompromised patients, this case suggests that percutaneous drainage guided by US or computed tomography is an efficient treatment alternative to splenectomy. Copyright © 2015. Published by Elsevier Inc.