Detection of Amp C genes encoding for beta-lactamases in Escherichia coli and Klebsiella pneumoniae

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M Shanthi

2012-01-01

Full Text Available Purpose : Amp C beta-lactamase are Ambler class C enzymes that confer resistance to extended spectrum cephalosporins and are not inhibited by beta-lactamase inhibitors. Their detection is crucial, since the phenotypic tests are not standardised leading to ambiguity in interpretation of results. This study was done to detect the types of Amp C prevalent in Escherichia coli and Klebsiella pneumoniae by multiplex polymerase chain reaction (PCR. Materials and Methods : Seventy-seven consecutive cefoxitin resistant clinical isolates of E. coli (n = 25 and K. pneumoniae (n = 52 were included in the study. Antibiotic susceptibility testing to various classes of antibiotics was performed by disc diffusion using Clinical Laboratory Standards Institute (CLSI guidelines. Minimum inhibitory concentration (MIC to cefoxitin, imipenem and meropenem were determined by broth microdilution method. Isolates were screened for production of Extended Spectrum Beta-Lactamase (ESBL. Multiplex PCR was performed for the detection of Amp C genes after phenotypic testing (Hodge test and inhibitor based test. Results : Cefoxitin Hodge test was positive in 40 isolates which included 20 E. coli and 20 K. pneumoniae. There was zone enhancement with boronic acid in 55 isolates, of which 36 were K. pneumoniae and 19 were E. coli. Multiplex PCR detected Amp C in 11/25 E. coli and 12/52 K. pneumoniae isolates. The Amp C genes detected were CIT (Amp C origin - Citrobacter freundii, DHA (Dhahran Hospital, Saudi Arabia, ACC (Ambler class C, EBC (Amp C origin - Enterobacter cloacae groups. ESBL was co-produced in 54 isolates. Conclusions : Amp C was detected in 29.87% of the study isolates. Majority of them co-produced ESBL. The most common Amp C was the CIT family. Screen tests for cefoxitin resistance may be falsely positive due to production of carbapenamases.

Phenotypic and molecular characteristics of methicillin-resistant Staphylococcus aureus isolates from Ekiti State, Nigeria

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Olowe OA

2013-08-01

Full Text Available Olugbenga Adekunle Olowe,1 Olayinka Oluwatoyin Kukoyi,2 Samuel Sunday Taiwo,1 Olusola Ojurongbe,1 Oluyinka Oladele Opaleye,1 Oloyede Samuel Bolaji,1 Abiodun Adebimpe Adegoke,1 Olufunmilola Bamidele Makanjuola,1 David Olusoga Ogbolu,3 Oyebode Terry Alli31Department of Medical Microbiology and Parasitology, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomoso, Nigeria; 2Department of Microbiology, College of Sciences, Afe Babalola University, Ado-Ekiti, Nigeria; 3Department of Biomedical Sciences, College of Health Sciences, Lautech, Osogbo, NigeriaIntroduction: The characteristics and antimicrobial resistance profiles of Staphylococcus aureus differs according to geographical regions and in relation to antibiotic usage. The aim of this study was to determine the biochemical characteristics of the prevalent S. aureus from Ekiti State, Nigeria, and to evaluate three commonly used disk diffusion methods (cefoxitin, oxacillin, and methicillin for the detection of methicillin resistance in comparison with mecA gene detection by polymerase chain reaction.Materials and methods: A total of 208 isolates of S. aureus recovered from clinical specimens were included in this study. Standard microbiological procedures were employed in isolating the strains. Susceptibility of each isolate to methicillin (5 µg, oxacillin (1 µg, and cefoxitin (30 µg was carried out using the modified Kirby–Bauer/Clinical and Laboratory Standard Institute disk diffusion technique. They were also tested against panels of antibiotics including vancomycin. The conventional polymerase chain reaction method was used to detect the presence of the mecA gene.Results: Phenotypic resistance to methicillin, oxacillin, and cefoxitin were 32.7%, 40.3%, and 46.5%, respectively. The mecA gene was detected in 40 isolates, giving a methicillin-resistant S. aureus (MRSA prevalence of 19.2%. The S. aureus isolates were resistant to penicillin (82.7% and tetracycline

ARD June07 New.pmd

African Journals Online (AJOL)

personal

other drugs are largely experimental There is controversy over the mode of delivery (local or systemic) .... five parts namely community and service provider partnerships ...... Intramuscular (IM) ceftriaxone 250 mg single dose or. IM cefoxitin 2 g ...

Analysis of the Structure and Function of FOX-4 Cephamycinase.

Science.gov (United States)

Lefurgy, S T; Malashkevich, V N; Aguilan, J T; Nieves, E; Mundorff, E C; Biju, B; Noel, M A; Toro, R; Baiwir, D; Papp-Wallace, K M; Almo, S C; Frere, J-M; Bou, G; Bonomo, R A

2016-02-01

Class C β-lactamases poorly hydrolyze cephamycins (e.g., cefoxitin, cefotetan, and moxalactam). In the past 2 decades, a new family of plasmid-based AmpC β-lactamases conferring resistance to cefoxitin, the FOX family, has grown to include nine unique members descended from the Aeromonas caviae chromosomal AmpC. To understand the basis for the unique cephamycinase activity in the FOX family, we determined the first X-ray crystal structures of FOX-4, apo enzyme and the acyl-enzyme with its namesake compound, cefoxitin, using the Y150F deacylation-deficient variant. Notably, recombinant expression of N-terminally tagged FOX-4 also yielded an inactive adenylylated enzyme form not previously observed in β-lactamases. The posttranslational modification (PTM), which occurs on the active site Ser64, would not seem to provide a selective advantage, yet might present an opportunity for the design of novel antibacterial drugs. Substantial ligand-induced changes in the enzyme are seen in the acyl-enzyme complex, particularly the R2 loop and helix H10 (P289 to N297), with movement of F293 by 10.3 Å. Taken together, this study provides the first picture of this highly proficient class C cephamycinase, uncovers a novel PTM, and suggests a possible cephamycin resistance mechanism involving repositioning of the substrate due to the presence of S153P, N289P, and N346I substitutions in the ligand binding pocket. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Susceptibility of anaerobic bacteria in Auckland: 1991-1996.

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Shore, K P; Pottumarthy, S; Morris, A J

1999-11-12

To determine the antimicrobial susceptibility of local anaerobic bacteria. The antimicrobial susceptibility of 357 obligate anaerobes collected between 1991 and 1997 was determined by a standard agar dilution method. Isolates tested included Bacteroides spp. 131, Fusobacterium spp. 12, Prevotella spp. 13, Veillonella spp. 5, Clostridium perfringens 27, other Clostridium spp. 29, Propionibacterium spp. 57, Actinomyces spp. 7, other non-sporing gram-positive bacilli 28 and Peptostreptococcus spp. 48. Ten antimicrobials were tested: penicillin, amoxycillin/ clavulanic acid, pipercillin/tazobactam, ceftriaxone, cefoxitin, cefotetan, imipenem, meropenem, clindamycin and metronidazole. Imipenem, pipercillin/tazobactam, meropenem and amoxycillin/clavulanic acid were active against virtually all anaerobes tested. Metronidazole was active against all anaerobic gram-negative bacteria and Clostridium spp., but had variable activity against other anaerobes. Cefoxitin was the most active cephalosporin against Bacteroides spp., with 76%, 64% and 15% of Bacteroides spp. being susceptible to cefoxitin, cefotetan and ceftriaxone, respectively. Penicillin had poor activity against anaerobic gram negative bacilli. Actinomyces and Propionibacterium spp. were susceptible to all antimicrobials tested except metronidazole. Variable results were obtained with other antimicrobial-organism combinations. Comparison of results with data from a previously published survey showed little change in susceptibility except for increased resistance of Bacteroides fragilis to ceftriaxone and Clostridium species (not C perfringens) to clindamycin. Our results update the local susceptibility profile of anaerobic bacteria and may be considered when choosing an antimicrobial agent for prophylaxis or treatment of anaerobic infections.

Detection of Methicillin Resistant Staphylococcus aureus and Determination of Minimum Inhibitory Concentration of Vancomycin for Staphylococcus aureus Isolated from Pus/Wound Swab Samples of the Patients Attending a Tertiary Care Hospital in Kathmandu, Nepal

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Raghabendra Adhikari

2017-01-01

Full Text Available The present study was conducted to evaluate the performance of cefoxitin disc diffusion method and oxacillin broth microdilution method for detection of methicillin resistant S. aureus (MRSA, taking presence of mecA gene as reference. In addition, inducible clindamycin resistance and beta-lactamase production were studied and minimum inhibitory concentration (MIC of vancomycin for S. aureus isolates was determined. A total of 711 nonrepeated pus/wound swab samples from different anatomic locations were included in the study. The Staphylococcus aureus was identified on the basis of colony morphology, Gram’s stain, and biochemical tests. A total of 110 (15.47% S. aureus isolates were recovered, of which 39 (35.50% isolates were identified as MRSA by cefoxitin disc diffusion method. By oxacillin broth microdilution method, 31.82% of the Staphylococcus aureus isolates were found to be MRSA. However, mecA gene was present in only 29.1% of the isolates. Further, beta-lactamase production was observed in 71.82% of the isolates, while inducible clindamycin resistance was found in 10% of S. aureus isolates. The MIC value of vancomycin for S. aureus ranged from 0.016 μg/mL to 1 μg/mL. On the basis of the absolute sensitivity (100%, both phenotypic methods could be employed for routine diagnosis of MRSA in clinical microbiology laboratory; however cefoxitin disc diffusion could be preferred over MIC method considering time and labour factor.

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

2015-01-01

-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...

Detection of Oxacillin Resistance in Staphylococcus aureus Isolated from the Neonatal and Pediatric Units of a Brazilian Teaching Hospital

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Valéria Cataneli Pereira

2009-01-01

Full Text Available Objective: To determine, by phenotypic and genotypic methods, oxacillin susceptibility in Staphylococcus aureus strains isolated from pediatric and neonatal intensive care unit patients seen at the University Hospital of the Botucatu School of Medicine.Methods: A total of 100 S. aureus strains isolated from the following materials were studied: 25 blood cultures, 21 secretions, 12 catheters, 3 cannulae and one chest drain from 62 patients in the neonatal unit, and 36 blood cultures, one pleural fluid sample and one peritoneal fluid sample from 38 patients in the pediatric unit. Resistance of the S. aureus isolates to oxacillin was evaluated by the disk diffusion method with oxacillin (1 μg and cefoxitin (30 μg, agar screening test using Mueller-Hinton agar supplemented with 6 μg/ml oxacillin and 4% NaCl, and detection of the mecA gene by PCR. In addition, the isolates were tested for β-lactamase production using disks impregnated with Nitrocefin and hyperproduction of β-lactamase using amoxicillin (20 μg and clavulanic acid (10 μg disks.Results: Among the 100 S. aureus strains included in the study, 18.0% were resistant to oxacillin, with 16.1% MRSA being detected in the neonatal unit and 21.0% in the pediatric unit. The oxacillin (1 μg and cefoxitin (30 μg disk diffusion methods presented 94.4% and 100% sensitivity, respectively, and 98.8% specificity. The screening test showed 100% sensitivity and 98.8% specificity. All isolates produced β-lactamase and one of these strains was considered to be a hyperproducer.Conclusions: The 30 μg cefoxitin disk diffusion method presented the best result when compared to the 1 μg oxacillin disk. The sensitivity of the agar screening test was similar to that of the cefoxitin disk diffusion method and higher than that of the oxacillin disk diffusion method. We observed variations in the percentage of oxacillin-resistant isolates during the study period, with a decline over the last years which

Detection of Oxacillin Resistance in Isolated from the Neonatal and Pediatric Units of a Brazilian Teaching Hospital

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Valéria Cataneli Pereira

2009-01-01

Full Text Available Objective To determine, by phenotypic and genotypic methods, oxacillin susceptibility in Staphylococcus aureus strains isolated from pediatric and neonatal intensive care unit patients seen at the University Hospital of the Botucatu School of Medicine. Methods A total of 100 S. aureus strains isolated from the following materials were studied: 25 blood cultures, 21 secretions, 12 catheters, 3 cannulae and one chest drain from 62 patients in the neonatal unit, and 36 blood cultures, one pleural fluid sample and one peritoneal fluid sample from 38 patients in the pediatric unit. Resistance of the S. aureus isolates to oxacillin was evaluated by the disk diffusion method with oxacillin (1 μg and cefoxitin (30 μg, agar screening test using Mueller-Hinton agar supplemented with 6 μg/ml oxacillin and 4% NaCl, and detection of the mecA gene by PCR. In addition, the isolates were tested for β-lactamase production using disks impregnated with Nitrocefin and hyperproduction of β-lactamase using amoxicillin (20 μg and clavulanic acid (10 μg disks. Results Among the 100 S. aureus strains included in the study, 18.0% were resistant to oxacillin, with 16.1% MRSA being detected in the neonatal unit and 21.0% in the pediatric unit. The oxacillin (1 μg and cefoxitin (30 μg disk diffusion methods presented 94.4% and 100% sensitivity, respectively, and 98.8% specificity. The screening test showed 100% sensitivity and 98.8% specificity. All isolates produced β-lactamase and one of these strains was considered to be a hyperproducer. Conclusions The 30 μg cefoxitin disk diffusion method presented the best result when compared to the 1 μg oxacillin disk. The sensitivity of the agar screening test was similar to that of the cefoxitin disk diffusion method and higher than that of the oxacillin disk diffusion method. We observed variations in the percentage of oxacillin-resistant isolates during the study period, with a decline over the last years which might

A randomized trial of the effects of antibiotic prophylaxis on epidural-related fever in labor.

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Sharma, Shiv K; Rogers, Beverly B; Alexander, James M; McIntire, Donald D; Leveno, Kenneth J

2014-03-01

It has been suggested that the development of maternal fever during epidural analgesia could be due to intrapartum infection. We investigated whether antibiotic prophylaxis before epidural placement decreases the rate of epidural-related fever. In this double-blind, placebo-controlled trial, 400 healthy nulliparous women requesting epidural analgesia were randomly assigned to receive either cefoxitin 2 g or placebo immediately preceding initiation of epidural labor analgesia. Maternal tympanic temperature was measured hourly, and intrapartum fever was defined as a maternal temperature of ≥38°C. Neonates born to women with fever were evaluated for possible sepsis, and available placentas were evaluated for the presence of neutrophilic inflammation. The primary outcome was maternal fever during epidural analgesia. Thirty-eight percent of women in the cefoxitin group and 40% of women in the placebo group developed fever (P = 0.68). The risk difference (95% confidence interval) for fever ≥38°C during labor (antibiotic versus placebo) was -2.0% (-11.5 to 7.5), and for fever >39°C during labor was -1.5% (-4.7 to 1.7). Approximately half of each study group had placental neutrophilic inflammation, but administration of cefoxitin had no significant effect on any grade of neutrophilic inflammation. Fever developed significantly more often in the women with placental neutrophilic inflammation compared with those without such inflammation (73/158 vs 33/144, P labor epidural analgesia is associated with placental inflammation, but fever and placental inflammation were not reduced with antibiotic prophylaxis. This finding suggests that infection is unlikely to be the cause in its development.

Role of inducers in detection of blaPDC-mediated oxyimino-cephalosporin resistance in Pseudomonas aeruginosa

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Birson Ingti

2017-01-01

Interpretation & conclusions: P. aeruginosa harbouring inducible (chromosomal and plasmid-mediated AmpC β-lactamase is a matter of concern as it may limit therapeutic option. Using cefoxitin-ceftazidime-based test is simple and may be used for detecting inducible AmpC β-lactamase amongst P. aeruginosa.

[Evaluation of four methods for detecting methicillin-resistant Staphylococcus aureus isolates from clinical specimens at a regional hospital in Mexico].

Science.gov (United States)

Acosta-Pérez, Gabriel; Rodríguez-Ábrego, Gabriela; Longoria-Revilla, Ernesto; Castro-Mussot, María Eugenia

2012-01-01

To estimate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in clinical isolates and to compare different methods for detection of MRSA in a lab with limited available personnel and resources. 140 Staphylococcus aureus strains isolated from patients in several departments were assayed for β-lactamase production, MIC-Vitek 2 oxacillin, ChromID MRSA, disk diffusion in agar for cefoxitin 30 μg and PBP2a detection. The results of conventional tests were compared with the "gold standard" PCR test for mecA gene. Cohen´s kappa index was also calculated in order to evaluate the intra assay agreement between the used methods. The found prevalence was 90.7%. Sensitivity and specificity were: disk diffusion for cefoxitin 97 and 92% respectively, MIC Vitek 2-XL 97 and 69%, ChromoID MRSA 97 and 85%, and PBP2a detection 98 and 100%. All methods are very good for detecting MRSA, choosing a method to use will depend on each laboratory infrastructure.

Wound infection prophylaxis in pediatric acute appendicitis: a 26-year prospective study.

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Ein, Sigmund H; Sandler, Anthony

2006-03-01

The purpose of this study was to determine the best wound infection prophylaxis in pediatric acute appendicitis. From 1969 to 1995 inclusive, 453 consecutive pediatric patients at the same children's hospital had an appendix with acute inflammation (acute appendicitis) removed by the same staff surgeon and his resident. The stump was not inverted, and chromic catgut was used throughout. No intraperitoneal antibiotics, irrigation, or drains were used, and the skin closure was with silk sutures initially and then with staples since 1986. The infants and children were divided into 6 consecutive groups of 52 to 96 patients, with each group lasting 2 to 5 years. The wound treatment groups were as follows: no treatment, drain or pack, drain or pack plus antibiotic powder, antibiotic powder, preoperative intravenous antibiotic plus antibiotic powder, and preoperative intravenous antibiotic. The wound Penrose drain, one half-inch gauze pack, and/or antibiotic powder (ampicillin, 1977-1981; cefoxitin, 1982-1995) were all placed in the subcutaneous space. There were a total of 50 (11%) wound infections (pus) that occurred between 4 and 40 days when no antibiotic powder was used and 2 to 14 days with antibiotic powder. In all 6 groups of patients, no organism was grown in most (80%) infections and Escherichia coli was the second commonest (12%). The serous ooze, which occurred only with the use of antibiotic powder (8%), was seen between 6 and 18 days, and no organism was ever cultured. The patients with preoperative (or intraoperative) intravenous antibiotics (cefoxitin) plus wound antibiotic powder (cefoxitin) had the lowest infection rate (2.5%). When this group was compared with the baseline group 1 (no treatment), it was the only group in which wound treatment made a significant difference (P = .003).

Comparative biochemical and computational study of the role of naturally occurring mutations at Ambler positions 104 and 170 in GES β-lactamases.

Science.gov (United States)

Kotsakis, Stathis D; Miriagou, Vivi; Tzelepi, Eva; Tzouvelekis, Leonidas S

2010-11-01

In GES-type β-lactamases, positions 104 and 170 are occupied by Glu or Lys and by Gly, Asn, or Ser, respectively. Previous studies have indicated an important role of these amino acids in the interaction with β-lactams, although their precise role, especially that of residue 104, remains uncertain. In this study, we constructed GES-1 (Glu104, Gly170), GES-2 (Glu104, Asn170), GES-5 (Glu104, Ser170), GES-6 (Lys104, Ser170), GES-7 (Lys104, Gly170), and GES-13 (Lys104, Asn170) by site-specific mutagenesis and compared their hydrolytic properties. Isogenic comparisons of β-lactam resistance levels conferred by these GES variants were also performed. Data indicated the following patterns: (i) Lys104-containing enzymes exhibited enhanced hydrolysis of oxyimino-cephalosporins and reduced efficiency against imipenem in relation to enzymes possessing Glu104, (ii) Asn170-containing enzymes showed reduced hydrolysis rates of penicillins and older cephalosporins, (iii) Ser170 enabled GES to hydrolyze cefoxitin efficiently, and (iv) Asn170 and Ser170 increased the carbapenemase character of GES enzymes but reduced their activity against ceftazidime. Molecular dynamic simulations of GES apoenzyme models, as well as construction of GES structures complexed with cefoxitin and an achiral ceftazidime-like boronic acid, provided insights into the catalytic behavior of the studied mutants. There were indications that an increased stability of the hydrogen bonding network of Glu166-Lys73-Ser70 and an altered positioning of Trp105 correlated with the substrate spectra, especially with acylation of GES by imipenem. Furthermore, likely effects of Ser170 on GES interactions with cefoxitin and of Lys104 on interactions with oxyimino-cephalosporins were revealed. Overall, the data unveiled the importance of residues 104 and 170 in the function of GES enzymes.

Detection of oxacillin-susceptible mecA-positive Staphylococcus aureus isolates by use of chromogenic medium MRSA ID.

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Kumar, V Anil; Steffy, Katherin; Chatterjee, Maitrayee; Sugumar, Madhan; Dinesh, Kavitha R; Manoharan, Anand; Karim, Shamsul; Biswas, Raja

2013-01-01

Reports of oxacillin-susceptible mecA-positive Staphylococcus aureus strains are on the rise. Because of their susceptibility to oxacillin and cefoxitin, it is very difficult to detect them by using routine phenotypic methods. We describe two such isolates that were detected by chromogenic medium and confirmed by characterization of the mecA gene element.

Susceptibility of Eikenella corrodens to Newer Beta-Lactam Antibiotics

OpenAIRE

1981-01-01

In vitro susceptibility testing of 28 strains of Eikenella corrodens by the agar dilution technique showed that all strains were uniformly susceptible to penicillin, ticarcillin, cefoxitin, cefotaxime, N-formimidoyl thienamycin, and moxalactam and resistant to clindamycin and cefadroxil. Cefoperazone, piperacillin, and mezlocillin showed good activity, with some strains relatively resistant. Bacampicillin and cefamandole showed relatively poor activity.

Multidrug-Resistant Bacteroides fragilis Bacteremia in a US Resident: An Emerging Challenge

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Cristian Merchan

2016-01-01

Full Text Available We describe a case of Bacteroides fragilis bacteremia associated with paraspinal and psoas abscesses in the United States. Resistance to b-lactam/b-lactamase inhibitors, carbapenems, and metronidazole was encountered despite having a recent travel history to India as the only possible risk factor for multidrug resistance. Microbiological cure was achieved with linezolid, moxifloxacin, and cefoxitin.

Detection of Amp C Beta Lactamases in Clinical Isolates of ...

African Journals Online (AJOL)

A total of 81 consecutive non repetitive clinical isolates of Escherichia coli (n=40) and Klebsiella spp. (n=41) were screened for AmpC production by disc diffusion method using cefoxitin (30 Zg) disc and confirmed by inhibitor based test using boronic acid as inhibitor. A total of 16 E.coli isolates (40%) and 16 Klebsiella ...

Comparative in vitro susceptibilities of anaerobic bacteria to cefmenoxime, cefotetan, and N-formimidoyl thienamycin.

OpenAIRE

Owens, W E; Finegold, S M

1983-01-01

The in vitro activities of cefmenoxime, cefotetan, and N-formimidoyl thienamycin were compared with those of other antimicrobial agents (metronidazole, clindamycin, cefoxitin, and moxalactam) against anaerobic bacteria. The data obtained indicate that N-formimidoyl thienamycin exhibits excellent activity against anaerobic bacteria; cefotetan and cefmenoxime, though less active, should be of value in treating selected anaerobic infections.

Antimicrobial Resistance of Rapidly Growing Mycobacteria in Western Taiwan: SMART Program 2002

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Tsi-Shu Huang

2008-04-01

Conclusion: The resistance of RGM in Taiwan is not as high as previously reported (notably for tobramycin, ciprofloxacin and cefoxitin, but reduction in the susceptibility rates of clarithromycin and imipenem for the M. fortuitum and M. abscessus groups demonstrates the importance of in vitro susceptibility testing of clinically important isolates, as susceptibility may differ in different geographical areas, even regionally, and over time.

Research on the Phenotypic Characterization of Mrsa Strains Isolated from Animals

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Iulia Maria BUCUR

2017-05-01

Full Text Available Keywords: chromogen, methicillin, MRSA, resistance Introduction: Currently, both in staphylococci isolated from animals with different diseases, as well as in humans, the MRSA strains (Methicillin Resistant S. aureus are monitored, as the methicillin resistance is associated with the resistance to other antibiotic groups. Methicillin resistance is encoded by mec staphylococcal chromosomal cassettes (SCCmec, which are islands of resistance. These strains can be identified by molecular biology tests and tests that reveal several phenotypic characteristics. The research was made in order to characterize and identify phenotypically the MRSA staphylococci strains isolated from animals. Materials and Methods: Researches were made on 240 coagulase positive and coagulase negative strains of staphylococci. Mannitol fermentation was tested on Champan medium, free coagulase was revealed on Baird-Parker medium and to identify S. aureus subsp. aureus was used the chromogenic medium Chromatic Staph. Methicillin-resistant strains were detected by disc diffusion method, using biodiscs with methicillin, oxacillin and cefoxitin. Also, to identify the MRSA strains, was used the chromogenic medium Chromatic MRSA. Results: The isolates were positive to mannitol and produced complete haemolysis or were unhaemolytic. A total of 44 strains produced free coagulase on Baird-Parker medium, considered coagulase positive strains, while 196 were coagulase negative strains. The isolates conducted differently to methicillin: 22,08% of strains were resistant, 51,25% of strains were susceptible and 26,66% had intermediate resistance, while the resistant strains to oxacillin were 42,91%. The increased frequency of methicillin-resistant strains of staphylococci and, particularly, MRSA strains, determined using the cefoxitin disk diffusion test, which is more reliable than methicillin and oxacillin. On the MRSA chromogenic medium, the methicillin-resistant strains of staphylococci

Prevalence and Characterization of Staphylococcus aureus Strains in the Pork Chain Supply in Chile.

Science.gov (United States)

Velasco, Valeria; Vergara, José L; Bonilla, Ana M; Muñoz, Javier; Mallea, Alejandra; Vallejos, Diego; Quezada-Aguiluz, Mario; Campos, Jorge; Rojas-García, Pedro

2018-05-01

The detection of methicillin-resistant Staphylococcus aureus (MRSA) and other emerging strains in meat-producing animals and retail meat has increased the risk of contamination of food. The aim of this study was to determine the prevalence and characterize S. aureus strains isolated from the pork chain supply in Chile. A total of 487 samples were collected: 332 samples from pigs at farms and slaughterhouses (nasal, n = 155; skin, n = 177); 85 samples from carcasses at slaughterhouses; and 70 meat samples at supermarkets and retail stores. The isolation of S. aureus was carried out by selective enrichment and culture media. Biochemical testing (API ® Staph) and PCR (detection of the nuc and mecA genes) were used to confirm S. aureus and MRSA strains. The agglutination test was used to determine the protein PBP2'. Enterotoxins (SEA, SEB, SEC, SED) were determined by agglutination test and the se genes by PCR method. Oxacillin and cefoxitin susceptibility testing were carried out using the diffusion method. The overall prevalence of S. aureus in the pork meat supply was 33.9%. A higher prevalence was detected on carcasses (56.5%), in pigs sampled at farms (40.6%) than in pigs sampled at slaughterhouses (23.3%) and in nonpackaged retail meat (43.1%) than packaged retail meat (5.3%) (p ≤ 0.05). No significant differences (p > 0.05) were found between the prevalence in pigs (28.3%) and pork meat (32.9%) and between natural pig farming (33.3%) and conventional production (52.8%). The mecA gene and the protein PBP2' were not detected in S. aureus strains. Two S. aureus strains exhibited oxacillin and cefoxitin resistance, and one S. aureus strain was resistant to cefoxitin. One S. aureus strain isolated from a meat sample was positive for enterotoxin SEB. Although the mecA gene was not detected, oxacillin-resistant and seb-producing S. aureus strains were detected, which represent a risk in the pork chain supply.

Antimicrobial resistance of fecal Salmonella spp. isolated from all phases of pig production in 20 herds in Alberta and Saskatchewan

OpenAIRE

Rosengren, Leigh B.; Waldner, Cheryl L.; Reid‐Smith, Richard J.; Checkley, Sylvia L.; McFall, Margaret E.; Rajíc, Andrijana

2008-01-01

Salmonella spp. (n = 468), isolated from the feces of sows, nursery, and grow‐finish pigs in 20 farrow‐to‐finish herds in Alberta and Saskatchewan, were tested for susceptibility to 16 antimicrobials. No resistance was identified to amikacin, amoxicillin‐clavulanic acid, ceftiofur, ceftriaxone, ciprofloxacin or nalidixic acid, and less than 1% of the isolates were resistant to cefoxitin and gentamicin. Isolates were most commonly resistant to tetracycline (35%) and sulfamethoxazole (27%). Ove...

Die Wirkung von Desacetylcefotaxin, einem Metaboliten von Cefotaxim, in vitro und auf die experimentelle Infektion mit Escherichia coli

OpenAIRE

Wirbelauer, J.; Hof, H.; Hacker, Jörg

2009-01-01

Die MHK-Werte von Desacetylcefotaxim gegen verschiedene, z. T. ampicillinresistente Stämme von Escherichia coH, die mit Hilfe einer Agardilutionsmethode erhoben wurden, waren höher als die von Cefotaxim und Ceftriaxon, jedoch niedriger als die von Cefoxitin. In einem Modell der systemischen Infektion der Maus mit einem plasmidtragenden, betalactamaseproduzierenden Stamm von E. coli führte die Therapie mit Desacetylcefotaxim zu einer starken Reduktion der Keime pro Leber. Im Vergleich zur Ther...

In vitro activity of cefbuperazone, a new cephamycin, against anaerobic bacteria.

OpenAIRE

Prabhala, R H; Thadepalli, H; Rao, B; Bansal, M B; Marshall, R

1985-01-01

The 90% MIC of cefbuperazone (BMY 25182) was 32 micrograms/ml for Bacteroides fragilis and Bacteroides spp., 128 micrograms/ml for Fusobacterium and Clostridium spp., 64 micrograms/ml for Eubacterium and Peptococcus spp., 8 micrograms/ml for Actinomyces spp., and 32 micrograms/ml for Peptostreptococcus spp. The level of activity of cefbuperazone was higher against B. fragilis and lower against anaerobic cocci than those of related cephalosporins, i.e., cefoxitin, cefoperazone, cefotaxime, cef...

Prevalence and genotypic relatedness of methicillin resistant Staphylococcus aureus in a tertiary care hospital

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B A Fomda

2014-01-01

Full Text Available Background: Methicillin-resistant Staphylococcus aureus (MRSA is the most common multidrug-resistant pathogen causing nosocomial infections across the world. MRSA is not only associated with significant mortality and morbidity but also places a large economic strain on our health care system. MRSA isolates are also typically resistant to multiple, non-β-lactam antibiotics. We conducted a prospective study in a tertiary care hospital, to determine the prevalence of MRSA and to establish the clonal distribution of MRSA isolates recovered from various clinical specimens. Materials and Methods: Clinical samples were cultured and S. aureus was identified as per standard microbiological procedures. Susceptibility testing was done by agar disk diffusion and minimum inhibitory concentration (MIC method as recommended by CLSI. Methicillin resistance was detected by phenotypic methods namely, oxacillin disc diffusion (ODD, minimum inhibitory concentration (MIC of oxacillin, cefoxitin disk diffusion (CDD, and MIC of cefoxitin. Amplification of mecA gene by PCR was used as gold standard for detection of methicillin resistance. Pulsed field gel electrophoresis (PFGE typing was performed for MRSA isolates. Results: Out of 390 S. aureus isolates, 154 (39.48% isolates were MRSA and 236 (60.51% isolates were MSSA. Penicillin was the least effective antibacterial drug against the hospital associated S. aureus isolates with 85.64% resistance rate. All the isolates were susceptible to vancomycin. The MRSA showed a high level of resistance to all antimicrobials in general in comparison to the MSSA and the difference was statistically significant (P < 0.05. Multiplex PCR performed for all strains showed amplification of both the mecA and nucA genes in MRSA strains whereas MSSA strains showed amplification of only nucA gene. PFGE of these isolates showed 10 different patterns. Conclusion: Prevalence of MRSA in our hospital was 39.48%. Most of these isolates were

Antimicrobial resistance in coagulase-negative staphylococci from Nigerian traditional fermented foods.

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Fowoyo, P T; Ogunbanwo, S T

2017-01-31

Coagulase-negative staphylococci have become increasingly recognized as the etiological agent of some infections. A significant characteristic of coagulase-negative staphylococci especially strains isolated from animals and clinical samples is their resistance to routinely used antibiotics although, resistant strains isolated from fermented foods have not been fully reported. A total of two hundred and fifty-five CoNS isolates were subjected to antimicrobial susceptibility test using the disc diffusion technique. The minimum inhibitory concentration of the isolates to the tested antibiotics was determined using the microbroth dilution method. Methicillin resistant strains were confirmed by detection of methicillin resistant genes (mecA) and also employing cefoxitin screening test. The isolates were confirmed to be methicillin resistant by the detection of mecA genes and the cefoxitin screening test. The isolates demonstrated appreciable resistance to ampicillin (86.7%), sulfomethoxazole-trimethoprim (74.9%), amoxicillin-clavulanic acid (52.5%) and oxacillin (35.7%). Methicillin resistance was exhibited by 13 out of the 255 isolates although no mecA gene was detected. It was also observed that the methicillin resistant isolates were prevalent in these traditional foods; iru, kindirmo, nono and wara. This study has ameliorated the incidence of multiple antibiotic resistant coagulase-negative staphylococci in Nigerian fermented foods and if not tackled adequately might lead to horizontal transfer of antibiotic resistance from food to man.

A Rapid Phenotypic Whole Cell Screening Approach for the Identification of Small Molecule Inhibitors that Counter Beta-lactamase Resistance in Pseudomonas aeruginosa

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Collia, Deanna; Bannister, Thomas D.; Tan, Hao; Jin, Shouguang; Langaee, Taimour; Shumate, Justin; Scampavia, Louis; Spicer, Timothy P.

2017-01-01

Pseudomonas aeruginosa is an opportunistic human pathogen which is prevalent in hospitals and continues to develop resistance to multiple classes of antibiotics. Historically, β-lactam antibiotics have been the first line of therapeutic defense. However, the emergence of multidrug-resistant (MDR) strains of P. aeruginosa, such as AmpC β-lactamase overproducing mutants, limits the effectiveness of current antibiotics. Among AmpC hyper producing clinical isolates, inactivation of AmpG, which is essential for the expression of AmpC, increases bacterial sensitivity to β-lactam antibiotics. We hypothesize that inhibition of AmpG activity will enhance the efficacy of β-lactams against P. aeruginosa. Here, using a highly drug resistant AmpC inducible laboratory strain PAO1, we describe an ultra-high throughput whole cell turbidity assay designed to identify small molecule inhibitors of the AmpG. We screened 645K compounds to identify compounds with the ability to inhibit bacterial growth in the presence of Cefoxitin; an AmpC inducer, and identified 2,663 inhibitors which were also tested in the absence of Cefoxitin to determine AmpG specificity. The Z′ and S:B were robust at 0.87 ± 0.05 and 2.2 ± 0.2, respectively. Through a series of secondary and tertiary studies, including a novel luciferase based counterscreen, we ultimately identified 8 potential AmpG specific inhibitors. PMID:28850797

Comparative in vitro activity of the new oxacephem antibiotic, flomoxef (6315-S).

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Ruckdeschel, G; Eder, W

1988-10-01

The in vitro activity of flomoxef (6315-S) was determined and compared to that of different cephalosporins against 787 clinical isolates of staphylococci, Enterobacteriaceae and anaerobes. Flomoxef is similar in activity to latamoxef and cefotaxime against Enterobacteriaceae, slightly more active than cephalothin and cefamandole against oxacillin-sensitive strains of Staphylococcus aureus and minimally less active than cefamandole against oxacillin-resistant strains. Flomoxef showed similar or better activity than latamoxef and cefoxitin against most of the anaerobic species of medical importance.

Enterobacter Asburiae Pneumonia with Cavitation

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Cha, Seung Woo; Heo, Jeong Nam; Park, Choong Ki; Choi, Yo Won; Jeon, Seok Chol

2013-01-01

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 β-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.

Enterobacter Asburiae Pneumonia with Cavitation

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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)

2013-03-15

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.

In vitro activity of DMG-Mino and DMG-DM Dot, two new glycylcyclines, against anaerobic bacteria.

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Nord, C E; Lindmark, A; Persson, I

1993-10-01

The in vitro activity of DMG-Mino and DMG-DM Dot against 350 anaerobic bacterial strains including anaerobic cocci, Propionibacterium acnes, Clostridium perfringens, Clostridium difficile, Bacteroides fragilis, other Bacteroides species and fusobacteria was determined by the agar dilution method. Their activity was compared with that of minocycline, doxycycline, piperacillin, cefoxitin, imipenem, clindamycin and metronidazole. DMG-Mino and DMG-DM Dot and imipenem were the most active agents tested. DMG-Mino and DMG-DM Dot had in vitro activity superior to that of minocycline and doxycycline.

[Identification of anaerobic gram-negative bacilli isolated from various clinical specimens and determination of antibiotic resistance profiles with E-test methods].

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Demir, Cengiz; Keşli, Recep

2018-01-01

The aim of this study was to identify gram-negative anaerobic bacilli isolated from various clinical specimens that were obtained from patients with suspected anaerobic infections and to determine the antibiotic resistance profiles by using the antibiotic concentration gradient method. The study was performed in Afyon Kocatepe University Ahmet Necdet Sezer Research and Practice Hospital, Medical Microbiology Laboratory between 1 November 2014 and 30 October 2015. Two hundred and seventyeight clinical specimens accepted for anaerobic culture were enrolled in the study. All the samples were cultivated anaerobically by using Schaedler agar with 5% defibrinated sheep blood and Schaedler broth. The isolated anaerobic gram-negative bacilli were identified by using both the conventional methods and automated identification system (VITEK 2, bioMerieux, France). Antibiotic susceptibility tests were performed with antibiotic concentration gradient method (E-test, bioMerieux, France); against penicillin G, clindamycin, cefoxitin, metronidazole, moxifloxacin, imipenem, meropenem, ertapenem and doripenem for each isolate. Of the 28 isolated anaerobic gram-negative bacilli; 14 were identified as Bacteroides fragilis group, 9 were Prevotella spp., and 5 were Fusobacterium spp. The highest resistance rate was found against penicillin (78.5%) and resistance rates against clindamycin and cefoxitin were found as 17.8% and 21.4%, respectively. No resistance was found against metronidazole, moxifloxacin, imipenem, meropenem, ertapenem and doripenem. As a result, isolation and identification of anaerobic bacteria are difficult, time-consuming and more expensive when compared with the cost of aerobic culture. The rate of anaerobic bacteria isolation may be increased by obtaining the appropriate clinical specimen and appropriate transportation of these specimens. We believe that the data obtained from the study in our center may offer benefits for the follow up and treatment of infections

Pregnancy - associated human listeriosis: Virulence and genotypic analysis of Listeria monocytogenes from clinical samples.

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Soni, Dharmendra Kumar; Singh, Durg Vijai; Dubey, Suresh Kumar

2015-09-01

Listeria monocytogenes, a life-threatening pathogen, poses severe risk during pregnancy, may cause abortion, fetal death or neonatal morbidity in terms of septicemia and meningitis. The present study aimed at characterizing L. monocytogenes isolated from pregnant women based on serotyping, antibiotic susceptibility, virulence genes, in vivo pathogenicity test and ERIC- and REP-PCR fingerprint analyses. The results revealed that out of 3700 human clinical samples, a total of 30 (0.81%) isolates [12 (0.80%) from placental bit (1500), 18 (0.81%) from vaginal swab (2200)] were positive for L. monocytogenes. All the isolates belonged to serogroup 4b, and were + ve for virulence genes tested i.e. inlA, inlC, inlJ, plcA, prfA, actA, hlyA, and iap. Based on the mice inoculation tests, 20 isolates showed 100% and 4 isolates 60% relative virulence while 6 isolates were non-pathogenic. Moreover, 2 and 10 isolates were resistant to ciprofloxacin and cefoxitin, respectively, while the rest susceptible to other antibiotics used in this study. ERIC- and REP-PCR collectively depicted that the isolates from placental bit and vaginal swab had distinct PCR fingerprints except a few isolates with identical patterns. This study demonstrates prevalence of pathogenic strains mostly resistant to cefoxitin and/or ciprofloxacin. The results indicate the importance of isolating and characterizing the pathogen from human clinical samples as the pre-requisite for accurate epidemiological investigations.

Surveillance and molecular typing of Cronobacter spp. in commercial powdered infant formula and follow-up formula from 2011 to 2013 in Shandong Province, China.

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Zhang, Huaning; Hou, Peibin; Lv, Hui; Chen, Yuzhen; Li, Xinpeng; Ren, Yanyan; Wang, Mei; Tan, Hailian; Bi, Zhenwang

2017-05-01

Infection with Cronobacter spp. leads to neonatal meningitis, necrotizing enterocolitis and bacteremia. Cronobacter spp. are reported to comprise an important pathogen contaminating powdered infant formula (PIF) and follow-up formula (FUF), although little is known about the contamination level of Cronobacter spp. in PIFs and FUFs in China. In total, 1032 samples were collected between 2011 and 2013. Forty-two samples were positive, including 1.6% in PIFs and 6.5% in FUFs. The strains were susceptible to most antibiotics except for cefoxitin. Pulsed-field gel electrophoresis after XbaI digestion produced a total of 36 banding patterns. The 38 strains were found in 27 sequence types (STs), of which nine types (ST454 to ST462) had not been reported in other countries. The clinically relevant strains obtained from the 38 isolates in the present study comprised three ST3, two ST4, two ST8 and one ST1. The contamination rate in the PIF and FUF has stayed at a relatively high level. The contamination rate of PIF was significantly lower than FUF. The isolates had high susceptibility to the antibiotics tested, except cefoxitin. There were polymorphisms between the Cronobacter spp. as indicated by pulsed-field gel electrophoresis and multilocus sequence typing. Therefore, contamination with Cronobacter spp. remains a current issue for commercial infant formulas in China. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Six-Year Retrospective Review of Hospital Data on Antimicrobial Resistance Profile of Staphylococcus aureus Isolated from Skin Infections from a Single Institution in Greece

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Christina Stefanaki

2017-12-01

Full Text Available Objective: To determine the prevalence of resistant strains of Staphylococcus aureus (S. aureus isolated from Skin and soft tissue infections (SSTI to various antibiotics. Material and Methods: All culture-positive results for S. aureus from swabs taken from patients presenting at one Greek hospital with a skin infection between the years 2010–2015 were examined retrospectively. Bacterial cultures, identification of S. aureus and antimicrobial susceptibility testing were performed using the disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI guidelines and European Committee on Antimicrobial testing (EUCAST breakpoints. EUCAST breakpoints were applied if no CLSI were available. Results: Of 2069 S. aureus isolates identified, 1845 (88% were resistant to one or more antibiotics. The highest resistance was observed for benzylpenicillin (71.9%, followed by erythromycin (34.3%. Resistant strains to cefoxitin defined as MRSA (methicillin-resistant S. aureus represented 21% of total isolates. Interestingly, resistance to fusidic acid was 22.9% and to mupirocin as high as 12.7%. Low rates were observed for minocycline, rifampicin and trimethoprim/sulfamethoxazole (SXT. Resistance to antibiotics remained relatively stable throughout the six-year period, with the exception of cefoxitin, fusidic acid and SXT. A high percentage of MRSA strains were resistant to erythromycin (60%, fusidic acid (46%, clindamycin (38% and tetracycline (35.5%. Conclusions: Special attention is required in prescribing appropriate antibiotic therapeutic regimens, particularly for MRSA. These data on the susceptibility of S. aureus may be useful for guiding antibiotic treatment.

Multicenter study of antimicrobial susceptibility of anaerobic bacteria in Korea in 2012.

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Lee, Yangsoon; Park, Yeon Joon; Kim, Mi Na; Uh, Young; Kim, Myung Sook; Lee, Kyungwon

2015-09-01

Periodic monitoring of regional or institutional resistance trends of clinically important anaerobic bacteria is recommended, because the resistance of anaerobic pathogens to antimicrobial drugs and inappropriate therapy are associated with poor clinical outcomes. There has been no multicenter study of clinical anaerobic isolates in Korea. We aimed to determine the antimicrobial resistance patterns of clinically important anaerobes at multiple centers in Korea. A total of 268 non-duplicated clinical isolates of anaerobic bacteria were collected from four large medical centers in Korea in 2012. Antimicrobial susceptibility was tested by the agar dilution method according to the CLSI guidelines. The following antimicrobials were tested: piperacillin, piperacillin-tazobactam, cefoxitin, cefotetan, imipenem, meropenem, clindamycin, moxifloxacin, chloramphenicol, metronidazole, and tigecycline. Organisms of the Bacteroides fragilis group were highly susceptible to piperacillin-tazobactam, imipenem, and meropenem, as their resistance rates to these three antimicrobials were lower than 6%. For B. fragilis group isolates and anaerobic gram-positive cocci, the resistance rates to moxifloxacin were 12-25% and 11-13%, respectively. Among B. fragilis group organisms, the resistance rates to tigecycline were 16-17%. Two isolates of Finegoldia magna were non-susceptible to chloramphenicol (minimum inhibitory concentrations of 16-32 mg/L). Resistance patterns were different among the different hospitals. Piperacillin-tazobactam, cefoxitin, and carbapemems are highly active beta-lactam agents against most of the anaerobes. The resistance rates to moxifloxacin and tigecycline are slightly higher than those in the previous study.

Investigating antibacterial activity of Satureja bachtiarica against coagulasenegative staphylococcus strains isolated from hospitalized patients in ICU,Tehran-Iran

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Niloofar Shadalooei

2016-09-01

Full Text Available Given the inappropriate use of antibiotics and prevalence of resistant bacteria, there is urgent need for antibacterial drugs that have fewer side effects than antibiotics. Satureja bachtiarica is a medicinal plant which had many uses in traditional medicine. In this research, the ethanol extract of leave of Satureja bachtiarica is tested on coagulase-negative staphylococcus strains. Materials and Methods: In this experimental study, after collecting and drying the plant extract, the ethanolic extract of the plant was extracted by soxhelet method. Then, the antibiotic resistance pattern of coagulase-negative staphylococcus strains to Cefoxitin, Tobramycin, Kanamycin, Amikacin, Gentamicin, was assessed. To evaluate the antibacterial activity, the minimum inhibitory concentration was assessed by using micro dilution broth method.The results of this study showed that the antimicrobial effect of Satureja extract is concentration dependent. The results of the antimicrobial activity of extracts, indicate that alcoholic extract in all dilutions have an antimicrobial effect on the coagulase-negative staphylococcus strains. The results show that coagulase-negative staphylococcus strains have highest resistance against Cefoxitin (0.39 mg/ml and highest sensitivity to Amikacin (0.035 μl/ml. However, in 200 and 100 mg/ml concentrations the extract has higher antibacterial effect. According to the results of this study, ethanol extracts of leave of Satureja bachtiarica had growth inhibitory effect on coagulase-negative staphylococcus strains. Therefore this plant has the potential to be evaluated as an alternative or adjunct to antibiotics to treat coagulase-negative staphylococcus infections.

Carriage frequency, phenotypic and genotypic characteristics of Staphylococcus aureus isolated from dialysis and kidney tranplant patients at a hosptial in northern Paraná

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Luciana Borges Giarola

2012-09-01

Full Text Available The objective of the present study was to determine the frequency of Staphylococcus aureus nasal carriage among dialysis and kidney transplant patients, to identify the antimicrobial resistance profile of these strains and to verify their genetic profiles with the RW3A primer. The study included 159 individuals, comprising 111 dialysis and 48 kidney transplant patients. Of the 48 transplant patients, 75% were positive for S. aureus, whereas 49% of the 111 dialysis patients were carriers. Two samples yielded conflicting results for oxacillin sensitivity between the disk diffusion and minimum inhibitory concentration (MIC assays: both were sensitive by the disk diffusion assay and resistant by MIC (4 μg/ml. In the antibiogram by disk diffusion, ten samples were resistant to cefoxitin, among which eight were also resistant to oxacillin. The resistance of the ten samples to cefoxitin by the disk diffusion assay was confirmed by MIC. Of the ten oxacillin-resistant samples, eight harbored the mecA gene. All samples were sensitive to vancomycin, and most were resistant to penicillin and demonstrated high rates of resistance to the other antimicrobials tested. The samples from dialysis patients exhibited a more homogenous genetic profile. Among the samples with a high percent similarity, no correlation with sensitivity or resistance to oxacillin was observed. According to the results of this study, the implementation of prevention and control measures, such as increased restrictions on prescriptions for antimicrobial drugs and nasal decontamination prior to high-risk procedures, is recommended.

The soil microbiota harbors a diversity of carbapenem-hydrolyzing β-lactamases of potential clinical relevance

DEFF Research Database (Denmark)

Gudeta, Dereje Dadi; Bortolaia, Valeria; Amos, Greg

2016-01-01

to identification of seven new MBLs in presumptive Pedobacter roseus (PEDO-1), Pedobacter borealis (PEDO-2), Pedobacter kyungheensis (PEDO-3), Chryseobacterium piscium (CPS-1), Epilithonimonas tenax (ESP-1), Massilia oculi (MSI-1), and Sphingomonas sp. (SPG-1). Carbapenemase production was likely an intrinsic...... (PEDO-1), an unusual amino acid residue at a key position for MBL structure and catalysis (CPS-1), and overlap with a putative OXA β-lactamase (MSI-1). Heterologous expression of PEDO-1, CPS-1, and ESP-1in E. coli significantly increased the MICs of ampicillin, ceftazidime, cefpodoxime, cefoxitin...

Prevalence of beta-lactamases among ampicillin-resistant Escherichia coli and Salmonella isolated from food animals in Denmark

DEFF Research Database (Denmark)

Olesen, Inger; Hasman, Henrik; Aarestrup, Frank Møller

2004-01-01

The genetic background for beta-lactamase-mediated resistance to beta-lactam antibiotics was examined by PCR and sequencing in 160 ampicillin-resistant isolates (109 Escherichia coli and 51 Salmonella) obtained from healthy and diseased food animals in Denmark. Sequencing revealed three different...... leading to increased production of the AmpC beta-lactamase were demonstrated in 11 cefoxitin-resistant or intermediate E. coli isolates. Nine of these isolates did not contain any bla(TEM) genes, whereas the remaining two did. No genes encoding SHV or extended-spectrum beta-lactamases were detected. Two...

Comparative Efficacy of Ceftaroline with Linezolid against Staphylococcus Aureus and Methicillin Resistant Staphylococcus Aureus

International Nuclear Information System (INIS)

Hafeez, A.; Munir, T.; Rehman, S.; Najeeb, S.; Gilani, M.; Latif, M.; Ansari, M.; Saad, N.

2015-01-01

Objective:To compare the in vitro antimicrobial efficacy of ceftaroline with linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. Study Design: Quasi-experimental study. Place and Duration of Study: Microbiology Department, Army Medical College, Rawalpindi, from January to December 2013. Methodology: Clinical samples from respiratory tract, blood, pus and various catheter tips routinely received in the Department of Microbiology, Army Medical College, Rawalpindi were innoculated on blood and MacConkey agar. Staphylococcus aureus was identified by colony morphology, Gram reaction, catalase test and coagulase test. Methicillin resistant Staphylococcus aureus detection was done by modified Kirby Bauer disc diffusion method using cefoxitin disc (30g) and the isolates were considered methicillin resistant if the zone of inhibition around cefoxitin disc was /sup 2/ 21 mm. Bacterial suspensions of 56 Staphylococcus aureus isolates and 50 MRSA isolates were prepared, which were standardized equal to 0.5 McFarland's turbidity standard and inoculated on Mueller-Hinton agar plates followed by application of ceftaroline and linezolid disc (Oxoid, UK), according to manufacturer's instructions. The plates were then incubated at 37 Degree C aerobically for 18 - 24 hours. Diameters of inhibition zone were measured and interpretated as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Out of 106 isolates all of the 56 Staphylococcus aureus (100%) were sensitive to ceftaroline and linezolid. However, out of 50 methicillin resistant Staphylococcus aureus, 48 (96%) were sensitive to ceftaroline whereas, 49 (98%) were sensitive to linezolid. Conclusion: Ceftaroline is equally effective as linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. (author)

Antimicrobial susceptibility of anaerobic bacteria in New Zealand: 1999-2003.

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Roberts, Sally A; Shore, Keith P; Paviour, Susan D; Holland, David; Morris, Arthur J

2006-05-01

Routine susceptibility testing of all anaerobic organisms is not advocated, but it is useful for laboratories to test periodically for anaerobic organisms and provide local susceptibility data to guide therapy. This study reports the national trend of antibiotic susceptibility of clinically significant anaerobes in New Zealand. Clinical isolates were tested using standardized methods against a range of antibiotics commonly used to treat anaerobic infections. Susceptibility was determined using NCCLS criteria. The change in susceptibility trends between this study and earlier studies was measured by comparing the geometric mean of the MIC. A total of 364 anaerobes were tested. Penicillin had poor activity against Bacteroides spp., Prevotella spp., Eubacterium spp., Clostridium tertium and Veillonella spp. In general, Fusobacterium spp., Bacteroides ureolyticus, Propionibacterium spp., Clostridium perfringens and anaerobic streptococci isolates, with the exception of Peptostreptococcus anaerobius, were penicillin susceptible. Amoxicillin/clavulanate showed good activity against most anaerobes, but resistance was seen with Bacteroides fragilis group and P. anaerobius isolates. Cefoxitin was more active than cefotetan, particularly against non-B. fragilis species, Eubacterium spp. and P. anaerobius. Meropenem and imipenem showed good activity against all anaerobes, with only 2 and 4% of Bacteroides spp., respectively, showing resistance. With the exception of Propionibacterium acnes isolates, which are predictably resistant, metronidazole was active against all anaerobes tested. There has been little change in susceptibility since 1997. Metronidazole, cefoxitin, piperacillin/tazobactam and amoxicillin/clavulanate remain good empirical choices when anaerobes are expected in our setting. No clinically relevant changes in susceptibility over time were found.

Antibiotic Resistance, RAPD- PCR Typing of Multiple Drug Resistant Strains of Escherichia Coli From Urinary Tract Infection (UTI).

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Marialouis, Xavier Alexander; Santhanam, Amutha

2016-03-01

Global spreading of multidrug resistant strains of Escherichia coli is responsible for Urinary Tract Infection (UTI) which is a major health problem in of concern. Among the gram negative bacteria, the major contributors for UTI belongs to the family Enterobacteriaceae, which includes E. coli, Klebsiella, Citrobacter and Proteus. However, E. coli accounts for the major cause of Urinary tract infections (UTIs) and accounts for 75% to 90% of UTI isolates. The main aim of this study is to analyse the phylogenetic grouping of clinical isolates of UTI E. coli. In this study nearly 58 E. coli strains were isolated and confirmed through microbiological, biochemical characterization. The urine samples were collected from outpatients having symptoms of UTI, irrespective of age and sex in Tamil Nadu, India. The isolates were subjected to analyse for ESBL and AmpC β-lactamase production. To understand its genetic correlation, molecular typing was carried out using RAPD-PCR method. Here we noted phenotypically twenty seven isolates were positive for ESBL and seven for AmpC β-lactamase production. However, among the ESBL isolates higher sensitivity was noted for Nitrofurantoin and Cefoxitin. It is worth to note that the prevalence of UTIs was more common among female and elderly male. Phylogenetic grouping revealed the presence of 24 isolates belonged to B2 group followed by 19 isolates to group A, eight isolates to group B1 and Seven isolates to group D. Phenotypically most of the strains were positive for ESBL and showed high sensitivity for Nitrofurantoin and cefoxitin.

Genotypic and Phenotypic Detection of AmpC β-lactamases in Enterobacter spp. Isolated from a Teaching Hospital in Malaysia.

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Mohd Khari, Fatin Izzati; Karunakaran, Rina; Rosli, Roshalina; Tee Tay, Sun

2016-01-01

The objective of this study was to determine the occurrence of chromosomal and plasmid-mediated β-lactamases (AmpC) genes in a collection of Malaysian isolates of Enterobacter species. Several phenotypic tests for detection of AmpC production of Enterobacter spp. were evaluated and the agreements between tests were determined. Antimicrobial susceptibility profiles for 117 Enterobacter clinical isolates obtained from the Medical Microbiology Diagnostic Laboratory, University Malaya Medical Centre, Malaysia, from November 2012-February 2014 were determined in accordance to CLSI guidelines. AmpC genes were detected using a multiplex PCR assay targeting the MIR/ACT gene (closely related to chromosomal EBC family gene) and other plasmid-mediated genes, including DHA, MOX, CMY, ACC, and FOX. The AmpC β-lactamase production of the isolates was assessed using cefoxitin disk screening test, D69C AmpC detection set, cefoxitin-cloxacillin double disk synergy test (CC-DDS) and AmpC induction test. Among the Enterobacter isolates in this study, 39.3% were resistant to cefotaxime and ceftriaxone and 23.9% were resistant to ceftazidime. Ten (8.5%) of the isolates were resistant to cefepime, and one isolate was resistant to meropenem. Chromosomal EBC family gene was amplified from 36 (47.4%) E. cloacae and three (25%) E. asburiae. A novel blaDHA type plasmid-mediated AmpC gene was identified for the first time from an E. cloacae isolate. AmpC β-lactamase production was detected in 99 (89.2%) of 111 potential AmpC β-lactamase producers (positive in cefoxitin disk screening) using D69C AmpC detection set. The detection rates were lower with CC-DDS (80.2%) and AmpC induction tests (50.5%). There was low agreement between the D69C AmpC detection set and the other two phenotypic tests. Of the 40 isolates with AmpC genes detected in this study, 87.5%, 77.5% and 50.0% of these isolates were positive by the D69C AmpC detection set, CC-DDS and AmpC induction tests, respectively

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

2004-09-01

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

Isolation and characterization of Enterobacteriaceae species infesting post-harvest strawberries and their biological control using bacteriophages.

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Kurtböke, D Ipek; Palk, A; Marker, A; Neuman, C; Moss, L; Streeter, K; Katouli, M

2016-10-01

Strawberry is a significantly consumed fruit worldwide, mostly without being subjected to disinfection processes. During the harvest and transfer from farm to consumers as well as where organic farming practises have been employed, the surface of the fruit may become contaminated by pathogenic bacteria. Post-harvest strawberry fruits in punnets available for public consumption were thus screened for the presence of enteric bacteria in the Sunshine Coast region of Queensland, Australia. Some of the tested samples (13 %) were found to carry such bacteria and even in greater numbers if organic amendments were used (69 %). The bacteria were found to belong in the genera of Escherichia, Enterobacter, Raoultella, Klebsiella, Pantoea, Shigella, Citrobacter and Cronobacter within the family Enterobacteriaceae. Some of the isolates were found to adhere to Caco-2 cells representing human gut epithelium as well as carrying virulence and toxin genes. Resistance mostly against sulphafurazole, cefoxitin, ampicillin and nitrofurantoin was found among 14 different antimicrobial agents tested including 100 % resistance to cefoxitin and ampicillin in the genus Pantoea. In the second phase of the study, bacteriophages were isolated against the isolates and were subsequently applied to post-harvest fruits. A significant (P ≤ 0.001) reduction in the number of enteric bacteria was observed when a high-titre polyvalent bacteriophage suspension (×10(12) PFU/mL) was applied to the fruit surface. Bacteriophages also decreased the adhesion of the Escherichia coli isolates to Caco-2 cells. Findings might indicate that biological control using bacteriophages might be of significant value for the industry targeting to reduce pathogenic loads of bacteria on the fruit.

Synergy of β-Lactams with Vancomycin against Methicillin-Resistant Staphylococcus aureus: Correlation of Disk Diffusion and Checkerboard Methods.

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Sy, Cheng Len; Huang, Tsi-Shu; Chen, Chii Shiang; Chen, Yao-Shen; Tsai, Hung-Chin; Wann, Shue-Renn; Wu, Kuan-Sheng; Chen, Jui-Kuang; Lee, Susan Shin-Jung; Liu, Yung-Ching

2016-03-01

Modified disk diffusion (MDD) and checkerboard tests were employed to assess the synergy of combinations of vancomycin and β-lactam antibiotics for 59 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Mu50 (ATCC 700699). Bacterial inocula equivalent to 0.5 and 2.0 McFarland standard were inoculated on agar plates containing 0, 0.5, 1, and 2 μg/ml of vancomycin. Oxacillin-, cefazolin-, and cefoxitin-impregnated disks were applied to the surface, and the zones of inhibition were measured at 24 h. The CLSI-recommended checkerboard method was used as a reference to detect synergy. The MICs for vancomycin were determined using the Etest method, broth microdilution, and the Vitek 2 automated system. Synergy was observed with the checkerboard method in 51% to 60% of the isolates when vancomycin was combined with any β-lactam. The fractional inhibitory concentration indices were significantly lower in MRSA isolates with higher vancomycin MIC combinations (P synergy in MRSA isolates with bacterial inocula equivalent to McFarland standard 0.5 were 33.0% and 62.5% for oxacillin, 45.1% and 52.4% for cefazolin, and 43.1% and 52.4% for cefoxitin when combined with 0.5 and 2 μg/ml of vancomycin, respectively. Based on our study, the simple MDD method is not recommended as a replacement for the checkerboard method to detect synergy. However, it may serve as an initial screening method for the detection of potential synergy when it is not feasible to perform other labor-intensive synergy tests. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Antibiotic resistance in Escherichia coli isolates from roof-harvested rainwater tanks and urban pigeon faeces as the likely source of contamination.

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Chidamba, Lizyben; Korsten, Lise

2015-07-01

The objective of this study was to investigate the risks associated with the use of roof-harvested rainwater (RHRW) and the implication of pigeons as the most likely source of contamination by testing for antibiotic resistance profiles of Escherichia coli. A total of 239 E. coli were isolated from thirty fresh pigeon faecal samples (130 isolates), 11 RHRW tanks from three sites in Pretoria (78) and two in Johannesburg (31). E. coli isolates were tested against a panel of 12 antibiotics which included ampicillin, amoxicillin, amikacin, cefoxitin, ceftriaxone, chloramphenicol, ciprofloxacin, cotrimoxazole, enrofloxacin, gentamicin, nalidixic acid and tetracycline. In all samples, resistance to ampicillin (22.7.9%), gentamicin (23.6%), amikacin (24%), tetracycline (17.4) and amoxicillin (16.9%) were the most frequently encountered form of resistance. However, a relatively higher proportion of isolates from pigeon faeces (67.3%) were antibiotic resistant than those from RHRW (53.3%). The highest number of phenotypes was observed for single antibiotics, and no single antibiotic resistance was observed for chloramphenicol, ceftriaxone, gentamicin, cefoxitin, cotrimoxazole, although they were detected in multiple antibiotic resistance (MAR) phenotypes. The highest multiple antibiotic resistance (MAR) phenotypes were observed for a combination of four antibiotics, on isolates from JHB (18.8%), pigeon faeces (15.2%) and Pretoria (5.1%). The most abundant resistance phenotype to four antibiotics, Ak-Gm-Cip-T was dominated by isolates from pigeon faeces (6.8%) with Pretoria and Johannesburg isolates having low proportions of 1.3 and 3.1%, respectively. Future studies should target isolates from various environmental settings in which rainwater harvesting is practiced and the characterisation of the antibiotic resistance determinant genes among the isolates.

[Application of anaerobic bacteria detection in oral and maxillofacial infection].

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Bao, Zhen-ying; Lin, Qin; Meng, Yan-hong; He, Chun; Su, Jia-zeng; Peng, Xin

2016-02-18

To investigate the distribution and drug resistance of anaerobic bacteria in the patients with oral and maxillofacial infection. Aerobic and anaerobic bacteria cultures from 61 specimens of pus from the patients with oral and maxillofacial infection in the Department of Oral and Maxillofacial Surgery, Peking University School of Stomatology were identified. The culture type was evaluated by API 20A kit and drug resistance test was performed by Etest method. The clinical data and antibacterial agents for the treatment of the 61 cases were collected, and the final outcomes were recorded. The bacteria cultures were isolated from all the specimens, with aerobic bacteria only in 6 cases (9.8%), anaerobic bacteria only in 7 cases (11.5%), and both aerobic and anaerobic bacteria in 48 cases (78.7%). There were 55 infected cases (90.2%) with anaerobic bacteria, and 81 anaerobic bacteria stains were isolated. The highest bacteria isolation rate of Gram positive anaerobic bacteria could be found in Peptostreptococcus, Bifidobacterium and Pemphigus propionibacterium. No cefoxitin, amoxicillin/carat acid resistant strain was detected in the above three Gram positive anaerobic bacteria. The highest bacteria isolation rate of Gram negative anaerobic bacteria could be detected in Porphyromonas and Prevotella. No metronidazole, cefoxitin, amoxicillin/carat acid resistant strain was found in the two Gram negative anaerobic bacteria. In the study, 48 patients with oral and maxillofacial infection were treated according to the results of drug resistance testing, and the clinical cure rate was 81.3%. Mixed aerobic and anaerobic bacteria cultures are very common in most oral and maxillofacial infection patients. Anaerobic bacteria culture and drug resistance testing play an important role in clinical treatment.

Epidemiology and antimicrobial resistance of B. fragilis group organisms isolated from clinical specimen and human intestinal microbiota Epidemiologia e resistência a antimicrobianos de microorganismos do grupo B. fragilis isolados de espécime clínico e microbiota intestinal humana

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Cibele Barreto Mano de Carvalho

1996-10-01

Full Text Available Epidemiological aspects and the antimicrobial susceptibility profile of the Bacteroides fragilis group isolated from clinical and human intestinal specimens were examined in this study. B. fragilis group strains were isolated from 46 (37% of 124 clinical specimens and the source of the samples was: Blood culture (3, intraabdominal infection (27, brain abscess (2, soft tissue infection (17, respiratory sinus (3, pleural aspirate (9, breast abscess (3, surgical infected wound (22, pelvic inflammatory disease (22, chronic otitis media (9 and miscellaneous (7. Intraabdominal and soft tissue infections were responsible for more than half of the clinical isolates. Susceptibility to penicillin, cefoxitin, tetracycline, metronidazole, chloramphenicol and clindamycin was examined. All isolates were susceptible to metronidazole and chloramphenicol. For clindamycin and cefoxitin the resistance rates observed were 21.7% and 10.9% respectively. Susceptibility profiles varied among the different species tested. A total of 37 species of B. fragilis group isolated from intestinal microbiota of individuals who had no antimicrobial therapy for at least 1 month before the sampling was also examined. All strains were also susceptible to chloramphenicol and motronidazole and the resistance rates to clindamycin and cefoxitin were 19.4% and 5.4% respectively. A few institutions, in Brazil, have monitored the antimicrobial susceptibility of B. fragilis group strains isolated from anaerobic infections. The resistance rates to cefoxitin and clindamycin and the variation in susceptibility patterns among the species isolated in this study emphasize the need for monitoring of susceptibility patterns of B. fragilis group organisms isolated, especially at our University Hospitals.Alguns aspectos epidemiológicos e o perfil de sensibilidade a antimicrobianos de amostras do grupo B. fragilis isoladas de espécime clínico e microbiota intestinal humana foram delineados neste

Coagulase-negative staphylococci (CoNS) isolated from ready-to-eat food of animal origin--phenotypic and genotypic antibiotic resistance.

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Chajęcka-Wierzchowska, Wioleta; Zadernowska, Anna; Nalepa, Beata; Sierpińska, Magda; Łaniewska-Trokenheim, Łucja

2015-04-01

The aim of this work was to study the pheno- and genotypical antimicrobial resistance profile of coagulase negative staphylococci (CoNS) isolated from 146 ready-to-eat food of animal origin (cheeses, cured meats, sausages, smoked fishes). 58 strains were isolated, they were classified as Staphylococcus xylosus (n = 29), Staphylococcus epidermidis (n = 16); Staphylococcus lentus (n = 7); Staphylococcus saprophyticus (n = 4); Staphylococcus hyicus (n = 1) and Staphylococcus simulans (n = 1) by phenotypic and genotypic methods. Isolates were tested for resistance to erythromycin, clindamycin, gentamicin, cefoxitin, norfloxacin, ciprofloxacin, tetracycline, tigecycline, rifampicin, nitrofurantoin, linezolid, trimetoprim, sulphamethoxazole/trimethoprim, chloramphenicol, quinupristin/dalfopristin by the disk diffusion method. PCR was used for the detection of antibiotic resistance genes encoding: methicillin resistance--mecA; macrolide resistance--erm(A), erm(B), erm(C), mrs(A/B); efflux proteins tet(K) and tet(L) and ribosomal protection proteins tet(M). For all the tet(M)-positive isolates the presence of conjugative transposons of the Tn916-Tn1545 family was determined. Most of the isolates were resistant to cefoxitin (41.3%) followed by clindamycin (36.2%), tigecycline (24.1%), rifampicin (17.2%) and erythromycin (13.8%). 32.2% staphylococcal isolates were multidrug resistant (MDR). All methicillin resistant staphylococci harboured mecA gene. Isolates, phenotypic resistant to tetracycline, harboured at least one tetracycline resistance determinant on which tet(M) was most frequent. All of the isolates positive for tet(M) genes were positive for the Tn916-Tn1545 -like integrase family gene. In the erythromycin-resistant isolates, the macrolide resistance genes erm(C) or msr(A/B) were present. Although coagulase-negative staphylococci are not classical food poisoning bacteria, its presence in food could be of public health significance due to the possible spread of

First Detection of FOX-1 AmpC -lactamase Gene Expression Among Escherichia coli Isolated from Abattoir Samples in Abakaliki, Nigeria

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Ejikeugwu Chika

2018-05-01

Full Text Available Objectives: Gram-negative bacteria represent the most relevant reservoir of resistance to antibiotics in the environment. The natural selection of resistant clones of bacteria in the environment by antimicrobial selective pressure is a relevant mechanism for spreading antibiotic resistance traits in both the community and hospital environment. This is in scenarios where antimicrobials are used irrationally, and even in the propagation of livestock, poultry birds, and for other veterinary purposes. This study sought to detect the prevalence of FOX-1 AmpC -lactamase genes from abattoir samples. Methods: The isolation of Escherichia coli, antimicrobial susceptibility testing, and -lactamase characterization was carried out using standard microbiology techniques. The production of AmpC -lactamase was phenotypically carried out using the cefoxitin-cloxacillin double-disk synergy test (CC-DDST, and FOX-1 AmpC genes was detected in the E. coli isolates using multiplex polymerase chain reaction. Results: Forty-eight E. coli isolates were recovered from the anal swabs of cows and 35 (72.9% isolates were positive for the production of -lactamase. Notably, high percentages of resistance to cefoxitin (91.7%, ceftriaxone (83.3%, imipenem (85.4%, ceftazidime (87.5%, ofloxacin (81.3%, and gentamicin (85.4% were found. FOX-1 genes were detected in three (6.3% of the 48 E. coli isolates phenotypically screened for AmpC enzyme production. Conclusions: Abattoirs could represent a major reservoir of resistance genes especially AmpC -lactamase, and this could serve as a route for the dissemination of multidrug-resistant bacteria in the community. Thus, the molecular identification of drug-resistant genes is vital for a reliable epidemiological investigation and the forestalling of the emergence and spread of these organisms through the food chain in this region.

MASTER: a model to improve and standardize clinical breakpoints for antimicrobial susceptibility testing using forecast probabilities.

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Blöchliger, Nicolas; Keller, Peter M; Böttger, Erik C; Hombach, Michael

2017-09-01

The procedure for setting clinical breakpoints (CBPs) for antimicrobial susceptibility has been poorly standardized with respect to population data, pharmacokinetic parameters and clinical outcome. Tools to standardize CBP setting could result in improved antibiogram forecast probabilities. We propose a model to estimate probabilities for methodological categorization errors and defined zones of methodological uncertainty (ZMUs), i.e. ranges of zone diameters that cannot reliably be classified. The impact of ZMUs on methodological error rates was used for CBP optimization. The model distinguishes theoretical true inhibition zone diameters from observed diameters, which suffer from methodological variation. True diameter distributions are described with a normal mixture model. The model was fitted to observed inhibition zone diameters of clinical Escherichia coli strains. Repeated measurements for a quality control strain were used to quantify methodological variation. For 9 of 13 antibiotics analysed, our model predicted error rates of  0.1% for ampicillin, cefoxitin, cefuroxime and amoxicillin/clavulanic acid. Increasing the susceptible CBP (cefoxitin) and introducing ZMUs (ampicillin, cefuroxime, amoxicillin/clavulanic acid) decreased error rates to < 0.1%. ZMUs contained low numbers of isolates for ampicillin and cefuroxime (3% and 6%), whereas the ZMU for amoxicillin/clavulanic acid contained 41% of all isolates and was considered not practical. We demonstrate that CBPs can be improved and standardized by minimizing methodological categorization error rates. ZMUs may be introduced if an intermediate zone is not appropriate for pharmacokinetic/pharmacodynamic or drug dosing reasons. Optimized CBPs will provide a standardized antibiotic susceptibility testing interpretation at a defined level of probability. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For

Antimicrobial Disk Susceptibility Testing of Leptospira spp. Using Leptospira Vanaporn Wuthiekanun (LVW) Agar.

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Wuthiekanun, Vanaporn; Amornchai, Premjit; Langla, Sayan; White, Nicholas J; Day, Nicholas P J; Limmathurotsakul, Direk; Peacock, Sharon J

2015-08-01

Leptospira Vanaporn Wuthiekanun (LVW) agar was used to develop a disk diffusion assay for Leptospira spp. Ten pathogenic Leptospira isolates were tested, all of which were susceptible to 17 antimicrobial agents (amoxicillin/clavulanic acid, amoxicillin, azithromycin, cefoxitin, ceftazidime, ceftriaxone, chloramphenicol, ciprofloxacin, clindamycin, doripenem, doxycycline, gentamicin, linezolid, nitrofurantoin, penicillin, piperacillin/tazobactam, and tetracycline). All 10 isolates had no zone of growth inhibition for four antimicrobials (fosfomycin, nalidixic acid, rifampicin, and trimethoprim/sulfamethoxazole). Of the ten Leptospira, seven had a growth inhibition zone of ≤ 21 mm for aztreonam, the zone diameter susceptibility break point for Enterobacteriaceae. This assay could find utility as a simple screening method during the epidemiological surveillance of antimicrobial resistance in Leptospira spp. © The American Society of Tropical Medicine and Hygiene.

Biochemical characterization of the 49 kDa penicillin-binding protein of Mycobacterium smegmatis.

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Mukherjee, T; Basu, D; Mahapatra, S; Goffin, C; van Beeumen, J; Basu, J

1996-01-01

The 49 kDa penicillin-binding protein (PBP) of Mycobacterium smegmatis catalyses the hydrolysis of the peptide or S-ester bond of carbonyl donors R1-CONH-CHR2-COX-CHR2-COO- (where X is NH or S). In the presence of a suitable amino acceptor, the reaction partitions between the transpeptidation and hydrolysis pathways, with the amino acceptor, behaving as a simple alternative nucleophile at the level of the acyl-enzyme. By virtue of its N-terminal sequence similarity, the 49 kDa PBP represents one of the class of monofunctional low-molecular-mass PBPs. An immunologically related protein of M(r) 52,000 is present in M. tuberculosis. The 49 kDa PBP is sensitive towards amoxycillin, imipenem, flomoxef and cefoxitin. PMID:8947487

Role of ser-237 in the substrate specificity of the carbapenem-hydrolyzing class A beta-lactamase Sme-1.

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Sougakoff, W; Naas, T; Nordmann, P; Collatz, E; Jarlier, V

1999-08-17

The role of the serine residue found at position 237 in the carbapenemase Sme-1 has been investigated by constructing a mutant in which Ser-237 was replaced by an alanine. The S237A mutant showed a catalytic behavior against penicillins and aztreonam very similar to that of Sme-1. By contrast, S237A was characterized by a reduced catalytic efficiency against cephems, such as cephalothin and cephaloridine. In addition, the weak activity of Sme-1 against the cephamycin cefoxitin was hardly detectable with the mutant enzyme. Finally, the Ser-237-->Ala mutation resulted in a marked decrease in catalytic activity against imipenem, showing that Ser-237 contributes to the carbapenemase activity of the class A beta-lactamase Sme-1.

[Influence of testing conditions on the susceptibility results of Staphylococcus cohnii to beta-lactams].

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Nowak, Tonmasz; Szewczyk, Eligia M

2006-01-01

The high occurence of coagulase-negative staphylococci among bacteria responsible for hospital infections is unquestioned. Studies on the poorly-known novobiocin-resistant, coagulase-negative Staphylococcus cohnii were undertaken. The possibilities of optimizing conditions for determination of susceptibility to beta-lactam antibiotics of this species were researched. In the case of S. cohnii the new cefoxitin test for detection of methicillin resistant strains, introduced by the National Reference Centre for Antibiotics in Poland was found as a good and of credible quality. It was also shown, that application in in vitro examination conditions stimulating the mechanisms of resistance to beta-lactam antibiotics, supplies credible results relating to their true susceptibility. The necessity of establishing individual conditions for susceptibility determination in different species of coagulase-negative staphylococci was suggested.

Prevalence and characterization of Salmonella among humans in Ghana

DEFF Research Database (Denmark)

Andoh, Linda Aurelia; Ahmed, Shabana; Olsen, John Elmerdahl

2017-01-01

Background Non-typhoidal Salmonella (NTS) is a public health problem worldwide and particularly in Africa with high disease burden. This study characterized Salmonella isolates from humans in Ghana to determine serovar distribution, phage types, and antimicrobial resistance. Further, the clonal...... relatedness among isolates was determined. Methods One hundred and thirty-seven Salmonella isolates (111 clinical and 26 public toilet) were characterized using standard serotyping, phage typing, and antimicrobial susceptibility testing methods. The molecular epidemiology of common serovars (Salmonella....... Fifty-eight (n = 58/112; 54.5%) strains were multi-resistant with low resistance to cephalosporins ceftazidime (8.0%), cefotaxime (4.5%), and cefoxitin (2.7%) with synergy to clavulanic acid indicating possible ESBLs. Isolates showed high resistance to trimethoprim (66.1%), tetracycline (61...

Comparative antimicrobial susceptibility of aerobic and facultative bacteria from community-acquired bacteremia to ertapenem in Taiwan

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Fung Chang-Phone

2007-07-01

Full Text Available Abstract Background Ertapenem is a once-a-day carbapenem and has excellent activity against many gram-positive and gram-negative aerobic, facultative, and anaerobic bacteria. The susceptibility of isolates of community-acquired bacteremia to ertapenem has not been reported yet. The present study assesses the in vitro activity of ertapenem against aerobic and facultative bacterial pathogens isolated from patients with community-acquired bacteremia by determining and comparing the MICs of cefepime, cefoxitin, ceftazidime, ceftriaxone, ertapenem, piperacillin, piperacillin-tazobactam, ciprofloxacin, amikacin and gentamicin. The prevalence of extended broad spectrum β-lactamases (ESBL producing strains of community-acquired bacteremia and their susceptibility to these antibiotics are investigated. Methods Aerobic and facultative bacteria isolated from blood obtained from hospitalized patients with community-acquired bacteremia within 48 hours of admission between August 1, 2004 and September 30, 2004 in Chang Gung Memorial Hospital at Keelung, Taiwan, were identified using standard procedures. Antimicrobial susceptibility was evaluated by Etest according to the standard guidelines provided by the manufacturer and document M100-S16 Performance Standards of the Clinical Laboratory of Standard Institute. Antimicrobial agents including cefepime, cefoxitin, ceftazidime, ceftriaxone, ertapenem, piperacillin, piperacillin-tazobactam, ciprofloxacin, amikacin and gentamicin were used against the bacterial isolates to test their MICs as determined by Etest. For Staphylococcus aureus isolates, MICs of oxacillin were also tested by Etest to differentiate oxacillin-sensitive and oxacillin-resistant S. aureus. Results Ertapenem was highly active in vitro against many aerobic and facultative bacterial pathogens commonly recovered from patients with community-acquired bacteremia (128/159, 80.5 %. Ertapenem had more potent activity than ceftriaxone, piperacillin

Antibiotic-resistant fecal bacteria, antibiotics, and mercury in surface waters of Oakland County, Michigan, 2005-2006

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Fogarty, Lisa R.; Duris, Joseph W.; Crowley, Suzanne L.; Hardigan, Nicole

2007-01-01

Water samples collected from 20 stream sites in Oakland and Macomb Counties, Mich., were analyzed to learn more about the occurrence of cephalosporin-resistant Escherichia coli (E. coli) and vancomycin-resistant enterococci (VRE) and the co-occurrence of antibiotics and mercury in area streams. Fecal indicator bacteria concentrations exceeded the Michigan recreational water-quality standard of 300 E. coli colony forming units (CFU) per 100 milliliters of water in 19 of 35 stream-water samples collected in Oakland County. A gene commonly associated with enterococci from humans was detected in samples from Paint Creek at Rochester and Evans Ditch at Southfield, indicating that human fecal waste is a possible source of fecal contamination at these sites. E. coli resistant to the cephalosporin antibiotics (cefoxitin and/ or ceftriaxone) were found at all sites on at least one occasion. The highest percentages of E. coli isolates resistant to cefoxitin and ceftriaxone were 71 percent (Clinton River at Auburn Hills) and 19 percent (Sashabaw Creek near Drayton Plains), respectively. Cephalosporin-resistant E. coli was detected more frequently in samples from intensively urbanized or industrialized areas than in samples from less urbanized areas. VRE were not detected in any sample collected in this study. Multiple antibiotics (azithromycin, erythromycin, ofloxacin, sulfamethoxazole, and trimethoprim) were detected in water samples from the Clinton River at Auburn Hills, and tylosin (an antibiotic used in veterinary medicine and livestock production that belongs to the macrolide group, along with erythromycin) was detected in one water sample from Paint Creek at Rochester. Concentrations of total mercury were as high as 19.8 nanograms per liter (Evans Ditch at Southfield). There was no relation among percentage of antibiotic-resistant bacteria and measured concentrations of antibiotics or mercury in the water. Genetic elements capable of exchanging multiple antibiotic

Isolation of bacteria from diabetic foot ulcers with special reference to anaerobe isolation by simple two-step combustion technique in candle jar

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Jayeeta Haldar

2017-01-01

Results: All the 43 samples were culture positive, of which aerobic Gram-negative bacteria (GNB predominated, followed by Staphylococcus aureus, Enterococcus and diphtheroids. Anaerobes isolated from 21 samples were Peptostreptococcus, Bacteroides, Porphyromonas, Veillonella spp. and Clostridium perfringens by both GasPak and in-house developed and modified candle jar techniques. Imipenem and metronidazole were most sensitive while clindamycin, penicillin and cefoxitin were least sensitive drugs for anaerobes. Aerobic GNB were found to be multidrug resistant, especially to penicillin and cephalosporins. The most sensitive drug was piperacillin-tazobactam. Interpretation & conclusions: For isolation of anaerobes from clinical specimens such as diabetic foot ulcers, modified candle jar technique was found to be as reliable as GasPak system. This modified technique needs to be tested for many other clinical materials which are not yet evaluated.

PERFIL DE SENSIBILIDADE MICROBIANA IN VITRO DE LINHAGENS PATOGÊNICAS DE Escherichia coli ISOLADAS DE CARNE BOVINA

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Samira Pirola Santos Mantilla

2012-06-01

Full Text Available This study aimed to analyze the antimicrobial resistance of Escherichia coli strains (EPEC A, EPEC B, EPEC C, EIEC A e EIEC B isolated from bovine meat. The antimicrobial susceptibility test was evaluated using the technique described by the National Committee for Clinical Laboratory Standards. The strains were resistant to most antibiotics tested, and gentamicin showed the best efficiency, with 84.9% of the strains showing sensitivity. In addition, cefoxitin was the least effective antimicrobial agent, have a higher percentage of resistant strains. The multidrug resistance to antimicrobials is a finding of great importance to public health, as resistant pathogens may be conveyed to consumers by the ingestion of animal products, making difficult the treatment of bacterial infections and increasing the occurrence of bacteria resistant to antibiotics.

Prevalence and characterization of methicillin-resistant Staphylococcus aureus carrying mecA or mecC and methicillin-susceptible Staphylococcus aureus in dairy sheep farms in central Italy.

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Giacinti, G; Carfora, V; Caprioli, A; Sagrafoli, D; Marri, N; Giangolini, G; Amoruso, R; Iurescia, M; Stravino, F; Dottarelli, S; Feltrin, F; Franco, A; Amatiste, S; Battisti, A

2017-10-01

Between January and May 2012, a total of 286 bulk tank milk samples from dairy sheep farms located in central Italy were tested for the presence of Staphylococcus aureus. One hundred fifty-three samples were positive for S. aureus (53.5%), with an average count of 2.53 log cfu/mL. A total of 679 S. aureus colonies were screened for methicillin resistance by the cefoxitin disk diffusion test, and 104 selected cefoxitin-susceptible isolates were also tested for their susceptibility to other antimicrobials representative of the most relevant classes active against Staphylococcus spp. by using the Kirby-Bauer disk diffusion method. Two methicillin-resistant Staphylococcus aureus (MRSA) isolates, carrying respectively the mecA and the mecC genes, were detected in 2 samples from 2 different farms (prevalence 0.7%). The mecA-positive MRSA isolate was blaZ positive, belonged to spa type t127, sequence type (ST)1, clonal complex (CC)1, carried a staphylococcal cassette chromosome mec (SCCmec) type IVa, and was phenotypically resistant to all the β-lactams tested and to erythromycin, streptomycin, kanamycin, and tetracycline. The mecC-positive MRSA isolate was negative for the chromosomally or plasmid-associated blaZ gene but positive for the blaZ allotype associated with SCCmec XI (blaZ-SCCmecXI), belonged to spa type 843, ST(CC)130, carried a SCCmec type XI, and was resistant only to β-lactams. Both MRSA were negative for the presence of specific immune-evasion and virulence genes such as those coding for the Panton-Valentine leucocidin, the toxic shock syndrome toxin 1, and the immune evasion cluster genes. Regarding the presence of the major S. aureus enterotoxin genes, the mecC-positive MRSA tested negative, whereas the ST (CC)1 mecA-positive MRSA harbored the seh gene. Among the 104 methicillin-susceptible S. aureus isolates examined for antimicrobial susceptibility, 63 (60.58%) were susceptible to all the antimicrobials tested, and 41 (39.42%) were resistant to at

Accuracy of phenotypic methicillin susceptibility methods in the detection of Staphylococcus aureus isolates carrying different SCCmec types

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Pricilla DM de Matos

2010-11-01

Full Text Available A total of 138 isolates, 118 methicillin-resistant Staphylococcus aureus (MRSA isolates (staphylococcal cassette chromosome type II, 20 isolates, type III, 39 isolates and type IV, 59 isolates and 20 methicillin-sensitive S. aureus isolates were evaluated by phenotypic methods: cefoxitin and oxacillin disk diffusion (DD, agar dilution (AD, latex agglutination (LA, oxacillin agar screening (OAS and chromogenic agar detection. All methods showed 100% specificity, but only the DD tests presented 100% sensitivity. The sensitivity of the other tests ranged from 82.2% (OAS-98.3% (AD. The LA test showed the second lowest sensitivity (86.4%. The DD test showed high accuracy in the detection of MRSA isolates, but there was low precision in the detection of type IV isolates by the other tests, indicating that the genotypic characteristics of the isolates should be considered.

Accuracy of phenotypic methicillin susceptibility methods in the detection of Staphylococcus aureus isolates carrying different SCCmec types.

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Matos, Pricilla D M de; Schuenck, Ricardo P; Cavalcante, Fernanda S; Caboclo, Roberta M F; Santos, Kátia Regina N dos

2010-11-01

A total of 138 isolates, 118 methicillin-resistant Staphylococcus aureus (MRSA) isolates (staphylococcal cassette chromosome type II, 20 isolates, type III, 39 isolates and type IV, 59 isolates) and 20 methicillin-sensitive S. aureus isolates were evaluated by phenotypic methods: cefoxitin and oxacillin disk diffusion (DD), agar dilution (AD), latex agglutination (LA), oxacillin agar screening (OAS) and chromogenic agar detection. All methods showed 100% specificity, but only the DD tests presented 100% sensitivity. The sensitivity of the other tests ranged from 82.2% (OAS)-98.3% (AD). The LA test showed the second lowest sensitivity (86.4%). The DD test showed high accuracy in the detection of MRSA isolates, but there was low precision in the detection of type IV isolates by the other tests, indicating that the genotypic characteristics of the isolates should be considered.

Study of methicillin resistant Staphylococcus aureus (MRSA) in Danish pigs at slaughter and in imported retail meat reveals a novel MRSA type in slaughter pigs

DEFF Research Database (Denmark)

Agersø, Yvonne; Hasman, Henrik; Cavaco, Lina M.

2012-01-01

Methicillin-resistant Staphylococcus aureus (MRSA), especially CC398, have emerged in livestock worldwide. We investigated the occurrence of MRSA in pigs at slaughter and in retail meat. During 2009, nasal swabs (n=789) were taken from pigs at slaughter. Moreover, 866 meat samples [Danish: pork...... (153), broiler meat (121), beef (142) and; imported: pork (173), broiler meat (193), and beef (84)] were randomly collected in retail stores and outlets. MRSA was isolated from nasal swabs or from meat samples after preenrichment (Mueller Hinton broth with 6.5% NaCl), selective enrichment (tryptone...... soya broth with 4mg/L cefoxitine and 75mg/L aztreonam) and selective plating on Brilliance Chromogenic MRSA agar. The presence of mecA was confirmed by PCR and the MRSA isolates were spa typed. Novel MRSA spa types were characterized by MLST, PFGE and SCCmec typing. Thirteen percent (101...

Mycobacterium abscessus Complex Infections in Humans.

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Lee, Meng-Rui; Sheng, Wang-Huei; Hung, Chien-Ching; Yu, Chong-Jen; Lee, Li-Na; Hsueh, Po-Ren

2015-09-01

Mycobacterium abscessus complex comprises a group of rapidly growing, multidrug-resistant, nontuberculous mycobacteria that are responsible for a wide spectrum of skin and soft tissue diseases, central nervous system infections, bacteremia, and ocular and other infections. M. abscessus complex is differentiated into 3 subspecies: M. abscessus subsp. abscessus, M. abscessus subsp. massiliense, and M. abscessus subsp. bolletii. The 2 major subspecies, M. abscessus subsp. abscessus and M. abscessus subsp. massiliense, have different erm(41) gene patterns. This gene provides intrinsic resistance to macrolides, so the different patterns lead to different treatment outcomes. M. abscessus complex outbreaks associated with cosmetic procedures and nosocomial transmissions are not uncommon. Clarithromycin, amikacin, and cefoxitin are the current antimicrobial drugs of choice for treatment. However, new treatment regimens are urgently needed, as are rapid and inexpensive identification methods and measures to contain nosocomial transmission and outbreaks.

Occurrence of extended-spectrum and AmpC β-lactamases in multiple drug resistant Salmonella isolates from clinical samples in Lagos, Nigeria

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Akinyemi KO

2017-01-01

Full Text Available KO Akinyemi,1 Bamidele Abiodun Iwalokun,2 Akeeb O Bola Oyefolu,1 CO Fakorede1 1Department of Microbiology, Lagos State University, Ojo, 2Molecular Biology and Biotechnology Division, Nigerian Institute of Medical Research, Yaba, Lagos, Nigeria Purpose: Salmonella spp. are important foodborne pathogens exhibiting increasing resistance to antimicrobial drugs. Resistance to broad-spectrum β-lactams, mediated by extended-spectrum β-lactamase (ESBL and AmpC β-lactamase enzymes is fast spreading and has had negative impacts on the clinical outcomes, particularly on third-generation cephalosporins. This study investigated the carriage of AmpC gene among multidrug-resistant Salmonella spp. from Lagos, Nigeria. Methods: Forty Salmonella spp. from clinical samples (S. typhi = 13; S. typhimurium = 10; S. enteritidis = 8; S. choleraesuis = 5; S. paratyphi = 4 were subjected to in vitro susceptibility test by disk diffusion methods. Isolates that were resistant to cefoxitin and third-generation cephalosporins were screened for ESBL (Double Disk Synergy Test Method and AmpC enzyme (AmpC disk test production. Detection of AmpC fox gene was carried out by polymerase chain reaction. Results: Thirty-two (80% of the Salmonella isolates were cefoxitin resistant. Plasmid-mediated AmpC β-lactamase and ESBL enzymes were recorded in 10/40 (25% and 16/40 (40% of the Salmonella isolates, respectively. Specifically, 16/40 (40% of the Salmonella isolates possessed 380 bp AmpC fox gene, with the highest occurrence found in S. typhi strains (43.8% followed by S. typhimurium (25%. There was no AmpC fox gene detected in S. paratyphi strains. Interestingly, coproduction of enzymes occurred in some of the isolates, raising fears of resistance to a multitude of antibiotics in the treatment of bacterial infections. Conclusion: Emergence of AmpC β-lactamase–producing Salmonella isolates in our environment was recorded for the first time, raising concern on increased

[Extended-spectrum beta-lactamase detection in Enterobacteriaceae and antibiotic susceptibility analysis].

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Cao, Wei; Tong, Ming-hua; Wang, Ji-gui

2002-02-28

To detect the extended-spectrum beta-lactamases (ESBLs) in family Enterobacteriaceae and analyze the antibiotic susceptibility of those ESBLs-producing strains. ESBLs were determined by the double-disk confirmatory test and 8 antibiotic susceptibilities were tested with the disk disffusion method in those strains producing ESBLs. Forty-seven ESBLs-producing strains comprised of 25 of E. coli, 14 of K. pneumoniae, 5 of E. cloacae, 1 of K. oxytoca, 1 of K. rhinoscleromatis, and 1 of S. liquefaciens. The susceptibility rates of those strains were: 100% for imipenem and meropenem, 89.4% for piperacillin/tazobactam, 72.4% for cefoxitin and 65.9% for cefotetan. E. coli and K. pneumoniae are the prime strains producing ESBLs in Enterobacteriaceae. Imipenem and meropenem are the best drugs to deal with those ESBLs-producing strains. Piperacillin/tazobactam is better than cephamycins and other beta-lactama/beta-lactamase inhibitor combination.

The effect of sub-inhibitory concentrations of rifaximin on urease production and on other virulence factors expressed by Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa and Staphylococcus aureus.

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Ricci, Annalisa; Coppo, Erika; Barbieri, Ramona; Debbia, Eugenio A; Marchese, Anna

2017-04-01

Rifaximin, a topical derivative of rifampin, inhibited urease production and other virulence factors at sub-MIC concentrations in strains involved in hepatic encephalopathy and the expression of methicillin resistance in Staphylococcus aureus. In particular, urease production was affected in all Proteus mirabilis and Klebsiella pneumoniae strains as well as in all tested Pseudomonas aeruginosa isolates. Other exotoxins, synthesized by P. aeruginosa, such as protease, gelatinase, lipase, lecithinase and DNAse were also not metabolized in the presence of rifaximin. This antibiotic inhibited pigment production in both P. aeruginosa and Chromobacterium violaceum, a biosensor control strain. Lastly, rifaximin affected haemolysin production in S. aureus and was able to restore cefoxitin susceptibility when the strain was cultured in the presence of sub-MICs of the drug. The present findings confirm and extend previous observations about the beneficial effects of rifaximin for the treatment of gastrointestinal diseases, since in this anatomic site, it reaches a large array of concentrations which prevents enterobacteria from thriving and/or producing their major virulence factors.

Screening of nasal carriage of methicillin-resistant Staphylococcus aureus during admission of patients to Frantz Fanon Hospital, Blida, Algeria

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Mohamed Amine Ouidri

2018-05-01

Full Text Available A study was performed of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA strains isolated from nasal preoperative samples. Of 663 samples assessed, staphylococcus was detected in 143 (21.57%. The disc diffusion method (cefoxitin 30 μg, a screening test (oxacillin 6 μg/mL and a search for Protein Binding Additional Penicillin 2 (PLP2a allowed the detection and confirmation of resistance to methicillin for 36 strains, a rate of 5.43% of the total population studied. Eight MRSA carriers received care in the trauma service, 14 in cardiology, five in ear, nose and throat, four in neurosurgery and paediatrics, and one in SCI. Thirty-six methicillin-resistant of the nasal portage strains are in their great majority, 27 of 36, rather limited multi-R character (two to three families namely resistance: tetracyclines, fluoroquinolones, aminoglycosides, macrolides. One of the MRSA strains was found to have intermediate sensitivity to vancomycin. Keywords: Antibiotic resistance, Healthy volunteers, MRSA, Prevalence, Staphylococcus aureus

Determination of in vitro susceptibility of Mycobacterium tuberculosis to cephalosporins by radiometric and conventional methods

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Heifets, L.B.; Iseman, M.D.; Cook, J.L.; Lindholm-Levy, P.J.; Drupa, I.

1985-01-01

Among eight cephalosporins and cephamycins tested in preliminary in vitro screening against Mycobacterium tuberculosis, the most promising for further study was found to be ceforanide, followed by ceftizoxime, cephapirin, and cefotaxime. Moxalactam, cefoxitin, cefamandole, and cephalothin were found to be not active enough against M. tuberculosis to be considered for further in vitro studies. The antibacterial activity of various ceforanide concentrations was investigated by three methods: (i) the dynamics of radiometric readings (growth index) in 7H12 broth; (ii) the number of CFU in the same medium; and (iii) the proportion method on 7H11 agar plates. There was a good correlation among the results obtained with these methods. The MIC for most strains ranged from 6.0 to 25.0 micrograms/ml. The BACTEC radiometric method is a reliable, rapid, and convenient method for preliminary screening and determination of the level of antibacterial activity of drugs not commonly used against M. tuberculosis

Cloning and sequence of the gene encoding a cefotaxime-hydrolyzing class A beta-lactamase isolated from Escherichia coli.

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Ishii, Y; Ohno, A; Taguchi, H; Imajo, S; Ishiguro, M; Matsuzawa, H

1995-01-01

Escherichia coli TUH12191, which is resistant to piperacillin, cefazolin, cefotiam, ceftizoxime, cefuzonam, and aztreonam but is susceptible to cefoxitin, latamoxef, flomoxef, and imipenem, was isolated from the urine of a patient treated with beta-lactam antibiotics. The beta-lactamase (Toho-1) purified from the bacteria had a pI of 7.8, had a molecular weight of about 29,000, and hydrolyzed beta-lactam antibiotics such as penicillin G, ampicillin, oxacillin, carbenicillin, piperacillin, cephalothin, cefoxitin, cefotaxime, ceftazidime, and aztreonam. Toho-1 was markedly inhibited by beta-lactamase inhibitors such as clavulanic acid and tazobactam. Resistance to beta-lactams, streptomycin, spectinomycin, sulfamethoxazole, and trimethoprim was transferred by conjugational transfer from E. coli TUH12191 to E. coli ML4903, and the transferred plasmid was about 58 kbp, belonging to incompatibility group M. The cefotaxime resistance gene for Toho-1 was subcloned from the 58-kbp plasmid by transformation of E. coli MV1184. The sequence of the gene for Toho-1 was determined, and the open reading frame of the gene consisted of 873 or 876 bases (initial sequence, ATGATG). The nucleotide sequence of the gene (DDBJ accession number D37830) was found to be about 73% homologous to the sequence of the gene encoding a class A beta-lactamase produced by Klebsiella oxytoca E23004. According to the amino acid sequence deduced from the DNA sequence, the precursor consisted of 290 or 291 amino acid residues, which contained amino acid motifs common to class A beta-lactamases (70SXXK, 130SDN, and 234KTG). Toho-1 was about 83% homologous to the beta-lactamase mediated by the chromosome of K. oxytoca D488 and the beta-lactamase mediated by the plasmid of E. coli MEN-1. Therefore, the newly isolated beta-lactamase Toho-1 produced by E. coli TUH12191 is similar to beta-lactamases produced by K. oxytoca D488, K. oxytoca E23004, and E. coli MEN-1 rather than to mutants of TEM or SHV enzymes

Evaluación de cuatro métodos para la detección de Staphylococcus aureus meticilino-resistente de muestras clínicas en un hospital regional Evaluation of four methods for detecting methicillin-resistant Staphylococcus aureus isolates from clinical specimens at a regional hospital in Mexico

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Gabriel Acosta-Pérez

2012-02-01

Full Text Available OBJETIVO: Investigar la prevalencia de Staphylococcus aureus meticilino-resistente (MRSA en aislados clínicos y determinar la concordancia entre los métodos de detección de MRSA en un laboratorio con recursos y personal limitado. MATERIAL Y MÉTODOS: Se analizaron 140 cepas de Staphylococcus aureus aisladas de muestras clínicas de diferentes departamentos mediante pruebas convencionales: producción de β-lactamasa, sensibilidad a oxacilina con MIC-Vitek 2-XL, ChromID MRSA, difusión en agar para discos de 30 μg de cefoxitina, detección de PBP2a y PCR para el gen mecA. Se determinó el índice kappa de Cohen, para evaluar la concordancia entre los diferentes métodos utilizados. RESULTADOS: La prevalencia encontrada fue de 90.7%. La sensibilidad y especificidad para los diferentes métodos de detección fue: difusión en disco para cefoxitina 97 y 92% respectivamente, MIC Vitek 2-XL 97 y 69%, ChromoID MRSA 97 y 85% y detección de PBP2a 98 y 100%. CONCLUSIONES: Todos los métodos son muy buenos para la detección de MRSA; la elección en el uso de cada método dependerá de la infraestructura de cada laboratorio.OBJETIVE: To estimate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA in clinical isolates and to compare different methods for detection of MRSA in a lab with limited available personnel and resources. MATERIAL AND METHODS: 140 Staphylococcus aureus strains isolated from patients in several departments were assayed for β-lactamase production, MIC-Vitek 2 oxacillin, ChromID MRSA, disk diffusion in agar for cefoxitin 30 μg and PBP2a detection. The results of conventional tests were compared with the "gold standard" PCR test for mecA gene. Cohen´s kappa index was also calculated in order to evaluate the intra assay agreement between the used methods. RESULTS: The found prevalence was 90.7%. Sensitivity and specificity were: disk diffusion for cefoxitin 97 and 92% respectively, MIC Vitek 2-XL 97 and 69%, Chromo

Do prophylactic antibiotics in gynecologic surgery prevent postoperative inflammatory complications? A systematic review.

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Boesch, Cedric Emanuel; Pronk, Roderick Franziskus; Medved, Fabian; Hentschel, Pascal; Schaller, Hans-Eberhard; Umek, Wolfgang

2017-06-01

The aim of this study was to systematically review the literature on antibiotic prophylaxis in gynaecologic surgeries to prevent inflammatory complications after gynaecological operations. The study was carried out as a systematic review. Only randomised controlled trials of women undergoing gynaecological surgery were included. The Medline and the Cochrane library databases were searched from 1966 to 2016. The trials must have investigated an antibiotic intervention to prevent an inflammatory complication after gynaecological surgery. Trials were excluded if they were not randomised, uncontrolled or included obstetrical surgery. Prophylactic antibiotics prevent inflammatory complications after gynaecological surgery. Prophylactic antibiotics are more effective in surgery requiring access to the peritoneal cavity or the vagina. Cefotetan appears to be more capable in preventing the overall inflammatory complication rate than cefoxitin or cefazolin. No benefit has been shown for the combination of antibiotics as prophylaxis. No difference has been shown between the long-term and short-term use of antibiotics. There is no need for the primary use of an anaerobic antibacterial agent. Antibiotics help to prevent postoperative inflammatory complications after major gynecologic surgeries.

Phenotypic and genotypic detection of methicillin-resistant Staphylococcus aureus in hunting dogs in Maiduguri metropolitan, Borno State, Nigeria

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Muhammad Mustapha

2016-05-01

Full Text Available Aim: To determine the presence of MRSA in hunting dogs in Maiduguri metropolitan. Materials and Methods: Phenotypic methods used includes microscopic technique, colony morphology study, catalase-coagulase tests, and the use of mannitol salt agar test, oxacillin resistance screening agar base, and antibiotic susceptibility testing methods. Genotypic approach was used for deoxyribonucleic acid extraction, and the presence of nuc and mecA gene was detected using polymerase chain reaction (PCR techniques. Results: Examination of 416 swab samples from nasal and perineal region of dogs revealed a total of 79.5% of S. aureus, where 62.5% of the isolates were MRSA. Molecular analysis revealed that 7nuc genes specific for S. aureus from 20 presumptive MRSA assay were all mecA PCR negative. The isolates were sensitive to gentamicin and ciprofloxacin but proved resistant to cefoxitin and oxacillin. Conclusion: High isolation rate of MRSA was found in hunting dogs. Significant level (p<0.05 of MRSA was isolated in the nasal cavity of hunting dogs than its perineum. Only nuc genes were detected from the MRSA isolates.

Prevalence of Antibiotic-resistance Enterobacteriaceae strains Isolated from Chicken Meat at Traditional Markets in Surabaya, Indonesia

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Yulistiani, R.; Praseptiangga, D.; Supyani; Sudibya; Raharjo, D.; Shirakawa, T.

2017-04-01

Antibiotic resistance in bacteria from the family Enterobacteriaceae is an important indicator of the emergence of resistant bacterial strains in the community. This study investigated the prevalence of antibiotic-resistant Enterobacteriaceae isolated from chicken meat sold at traditional markets in Surabaya Indonesia. In all, 203 isolates (43 Salmonella spp., 53 Escherichia coli, 16 Shigella spp., 22 Citrobacter spp., 13 Klebsiella spp, 24 Proteus spp., 15 Yersinia spp., 7 Enterobacter spp., 6 Serratia spp., 3 Edwardsiella spp. were resistant to tetracycline (69.95 %), nalidixid acid (54.19 %), sulfamethoxazole/sulfamethizole (42.36 %), chloramphenicol (12.81%), cefoxitin (6.40 %), gentamicin (5.91 %). Tetracycline was the antimicrobial that showed the highest frequency of resistance among Salmonella, E. coli, Citrobacter, Proteus and Erdwardsiella isolates, and nalidixid acid was second frequency of resistance. Overall, 124 (61.08 %) out of 203 isolates demonstrated multidrug resistance to at least two unrelated antimicrobial agents. The high rate of antimicrobial resistance in bacterial isolates from chicken meat may have major implications for human and animal health with adverse economic implications.

Isolation of Staphylococcus epidermidis from inflamed upper respiratory tract of an orange-spined hairy dwarf porcupine (Sphiggurus villosus

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F Fornazari

2012-01-01

Full Text Available The orange-spined hairy dwarf porcupine (Sphiggurus villosus is a rodent species common in most parts of South America, and little is known about the pathologies that can afflict it. A specimen was delivered at the Wildlife Research and Medical Center (CEMPAS, School of Veterinary Medicine and Animal Husbandry, UNESP, Botucatu, SP, Brazil. The animal showed intense apathy, with purulent secretion in the nasal cavity and fracture of the lumbar spine. Due to the unfavorable prognosis, the porcupine was euthanized and microbiological culture of nasal discharge showed Staphylococcus epidermidis. The antimicrobial resistance test revealed sensitivity to all tested antimicrobials (ampicillin, oxacillin, tetracycline, penicillin G, neomycin, cephalexin, gentamicin, enrofloxacin, ciprofloxacin, cotrimoxazol, cefoxitin and cephalothin. This bacterium is part of the nasal flora of humans and other animals, and may cause infection under certain conditions. In the present study, the infection and colonization by S. epidermidis was the probable cause of the inflammatory process. The sensitivity to all tested antimicrobials suggests that this strain has not been previously exposed to such drugs.

The Incidence of Nosocomial Toxigenic Clostridium difficile Associated Diarrhea in Tehran Tertiary Medical Centers

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Norakhoda Sadeghifard

2010-10-01

Full Text Available Clostridium difficile is the most common cause of nosocomial diarrhea. It is usually a consequence of antibiotic treatment, But sporadic cases can occur. This study was aimed to determine the frequency of the nosocomial Clostridium difficile (C. difficile associated diarrhea in Tehran University of Medical Sciences hospitals and study of antibacterial susceptibility of isolates. In this study a total of 942 stool samples from patients with nosocomial diarrhea that were hospitalized in Imam Khomeini hospital, Shariati hospital and Children clinical center were collected. The samples were cultured on a selective cycloserine cefoxitin fructose agar (CCFA and incubated in anaerobic conditions, at 37°C for 5 days. Isolates were characterized to species level by conventional biochemical tests. Bacterial cytotoxicity was assayed on tissue culture (vero. Antimicrobial sensitivity of isolated toxigenic C. difficile were investigated by kirby Beuer method (disk diffusion. Our findings show that, of the total patients, 57 toxigenic C. difficile (6.1% were isolated. Results of statistical analysis show significant differences between the rate of isolated toxigenic C. difficile and age group of patients (P

In vitro activity of flomoxef and cefazolin in combination with vancomycin.

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Simon, C; Simon, M

1991-01-01

207 clinical isolates from strains of patients from the University Children's Hospital of Kiel were investigated for their in vitro activity with the agar dilution method against flomoxef and cefazolin (alone and partially in combination with vancomycin). Staphylococci were also tested with other cephalosporins (cefoxitin, cefamandole, cefotaxime, cefotetan and latamoxef). Flomoxef and cefazolin always acted more vigorously on staphylococci than the other cephalosporins. Resistance of Staphylococcus aureus strains against flomoxef and cefazolin did not occur but was found in 15 and 5 of 98 Staphylococcus epidermidis strains, respectively. Enterococcus faecalis strains were always resistant against both drugs; Streptococcus faecium strains were only moderately sensitive. Combined testing of flomoxef or cefazolin with vancomycin showed synergism in almost all staphylococcal strains. Synergism was stronger when S. epidermidis strains were only weakly sensitive to or resistant against flomoxef and cefazolin in comparison to highly sensitive strains. Flomoxef (or cefazolin) acted synergistically in combination with vancomycin on E. faecalis and S. faecium with the exception of two strains of E. faecalis which showed an additive effect of both drugs.

Short communication: Characterization of methicillin-resistant Staphylococcus aureus isolated from raw milk fresh cheese in Colombia.

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Herrera, Fanny C; García-López, María-Luisa; Santos, Jesús A

2016-10-01

The aim of this study was the characterization of a collection of 8 methicillin-resistant Staphylococcus aureus (MRSA) isolates, obtained from samples of fresh cheese (Doble Crema) produced from raw cow milk in small dairies in Colombia. All the isolates harbored the mecA and Panton-Valentine leukocidin (PVL) genes, presented with SCCmec type IV, and belonged to multilocus sequence type 8 and spa type 024. Seven isolates presented 3 closely related pulsed-field gel electrophoresis profiles. Three of them carried the staphylococcal enterotoxin B gene. The isolates were resistant to cefoxitin, oxacillin, penicillin, and ampicillin and susceptible to all non-β-lactams antibiotics tested, with minimum inhibitory concentration values for oxacillin of 4 to 8mg/L. The isolates belonged to the community-acquired MRSA group, suggesting a human source of contamination. The risk of human infection by MRSA via contaminated foods is considered low, but contaminated food commodities can contribute to the worldwide dissemination of clones of community-acquired MRSA. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Phenotypic and genotypic detection of methicillin-resistant Staphylococcus aureus in hunting dogs in Maiduguri metropolitan, Borno State, Nigeria.

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Mustapha, Muhammad; Bukar-Kolo, Yachilla Maryam; Geidam, Yaqub Ahmed; Gulani, Isa Adamu

2016-05-01

To determine the presence of MRSA in hunting dogs in Maiduguri metropolitan. Phenotypic methods used includes microscopic technique, colony morphology study, catalase-coagulase tests, and the use of mannitol salt agar test, oxacillin resistance screening agar base, and antibiotic susceptibility testing methods. Genotypic approach was used for deoxyribonucleic acid extraction, and the presence of nuc and mecA gene was detected using polymerase chain reaction (PCR) techniques. Examination of 416 swab samples from nasal and perineal region of dogs revealed a total of 79.5% of S. aureus, where 62.5% of the isolates were MRSA. Molecular analysis revealed that 7nuc genes specific for S. aureus from 20 presumptive MRSA assay were all mecA PCR negative. The isolates were sensitive to gentamicin and ciprofloxacin but proved resistant to cefoxitin and oxacillin. High isolation rate of MRSA was found in hunting dogs. Significant level (p<0.05) of MRSA was isolated in the nasal cavity of hunting dogs than its perineum. Only nuc genes were detected from the MRSA isolates.

Methicillin-Resistant Staphylococcus aureus (MRSA Detection from the Hands of Jatinangor Community Health Center’s Health Care Providers

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Jeevanisha Patmanathan

2015-06-01

Full Text Available Background: Methicillin-resistant Staphylococcus aureus is a bacterium that is resistance towards β-lactam antibiotics, and it seems to be one of the leading causes of nosocomial infections. Hands of the health care workers are said to be the main source for the nosocomial transmission. Thus, the study aims to determine methicillin-resistant S. aureus from the hands of Jatinangor Community Health Center’s health care workers. Methods: Samples were taken from the hands of 30 Jatinangor Community Health Center’s staffs, including medical and paramedical; from October 2012 to November 2012. Then, these samples underwent further laboratory examinations, starting from culture, identification and susceptibility test towards cefoxitin, in identifying methicillin-resistant S. aureus. Results: Out of the 30 samples taken, 6 samples (20% were positive for S. aureus isolates. In which, 4 (13.33% of the samples were positive for methicillin-resistant S. aureus. Conclusions: Since, health care workers are the main people in contact with patients and maintaining proper hand hygiene makes a huge difference; hand hygiene should be given adequate attention for the benefit of all.

Agar dilution method for susceptibility testing of Neisseria gonorrhoeae

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Marta C de Castillo

1996-12-01

Full Text Available The antibiotic susceptibilities of Neisseria gonorrhoeae isolates obtained from patients attending a clinic for sexually transmitted diseases in Tucumán, Argentina, were determined by the agar dilution method (MIC. 3.5% of the isolates produced ²-lactamase. A total of 96.5% of ²-lactamase negative isolates tested were susceptible to penicillin (MIC < 2 µgml-1; 14.03% of the tested isolates were resistant to tetracycline (MIC < 2 µgml-1, and 98% of the tested isolates were susceptible to spectinomycin (MIC < 64 µgml-1. The MICs for 95% of the isolates, tested for other drugs were: < 2 µgml-1 for cefoxitin, < 0.06 µgml-1 for cefotaxime, < 0.25 µgml-1 for norfloxacin, < 10 µgml-1 for cephaloridine, < 10 µgml-1 for cephalexin, and < 50 µgml-1 for kanamycin. Antibiotic resistance among N. gonorrhoeae isolates from Tucumán, Argentina, appeared to be primarily limited to penicillin and tetracycline, which has been a general use against gonorrhoeae in Tucumán since 1960. Periodic monitoring of the underlying susceptibility profiles of the N. gonorrhoeae strains prevalent in areas of frequent transmission may provide clues regarding treatment options and emerging of drug resistance.

Nasal carriage of Methicillin-resistant Staphylococcus aureus among healthy population of Kashmir, India

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B A Fomda

2014-01-01

Full Text Available Background: Nasal colonisation with community acquired methicillin resistant Staphylococcus aureus (CA-MRSA is being increasingly reported, especially in places where people are in close contact and where hygiene is compromised. The aim of this study was to find out prevalence of methicillin resistant S.aureus (MRSA colonising anterior nares of healthy subjects. Materials and Methods: Nasal swabs of healthy subjects were collected aseptically and cultured using standard microbiological protocols. Antibiotic susceptibility was done by Kirby-Bauer disc diffusion method according to CLSI guidelines. Methicillin resistance was detected by cefoxitin disc diffusion method and confirmed by minimum inhibitory concentration (MIC and amplification of mecA gene by PCR. Strain typing of MRSA strains was done by PFGE. Results: Out of 820 samples, S.aureus was isolated from 229 (27.92% subjects. Of the 229 isolates, 15 were methicillin resistant. All S. aureus isolates were susceptible to vancomycin. Nasal carriage of MRSA was found to be 1.83% among healthy population. The isolates were found to be polyclonal by PFGE analysis. Conclusion: High prevalence of MRSA is a cause of concern and strategies to interrupt transmission should be implemented.

[Oxacillin-resistant coagulase-negative Staphylococci bacteremia at a teaching hospital in Santa Maria, State of Rio Grande do Sul, Brazil].

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Rigatti, Fabiane; Tizotti, Maísa Kraulich; Hörner, Rosmari; Domingues, Vanessa Oliveira; Martini, Rosiéli; Mayer, Letícia Eichstaedt; Khun, Fábio Teixeira; de França, Chirles Araújo; da Costa, Mateus Matiuzzi

2010-01-01

This study aimed to characterize the prevalence and susceptibility profile to oxacillin-resistant Coagulase-negative Staphylococci strains isolated from blood cultures in a teaching hospital, located in Santa Maria, RS. In addition, different methodologies for phenotypic characterization of mecA-mediated oxacillin resistance were compared with genotypic reference testing. After identification (MicroScan - Siemens), the isolates were tested for antimicrobial sensitivity using disk diffusion and automation (MicroScan - Siemens). The presence of mecA gene was identified by the polymerase chain reaction molecular technique. The most common species was Staphylococcus epidermidis (n=40, 67%). The mecA gene was detected in 54 (90%) strains, while analysis of the sensitivity profiles revealed a high rate of resistance to multiple classes of antimicrobial drugs. However, all isolates were uniformly sensitive to vancomycin and tigecycline. The cefoxitin disk was the phenotypic method that best correlated with the gold standard. Analysis of the clinical significance of CoNS isolated from hemocultures and the precise detection of oxacillin resistance represent decisive factors for the correct choice of antibiotic therapy. Although vancomycin constitutes the normal treatment in most Brazilian hospitals, reduction in its use is recommended.

Pharmacokinetics of cephem antibiotics in exudate of pelvic retroperitoneal space after radical hysterectomy and pelvic lymphadenectomy.

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Ito, K; Hayasaki, M; Tamaya, T

1990-01-01

Many cephalosporin antibiotics have recently been invented and attempts have been made to use them clinically. The choice of which of these drugs should be used has been difficult in gynecology. The efficacies of these drugs depend on their antibacterial spectra, potencies, and concentrations in tissues. This study was designed to investigate the pharmacokinetics of various cephem antibiotics in the exudate of the retroperitoneal space that is formed after radical hysterectomy and pelvic lymphadenectomy. These cephem antibiotics were cefoxitin, cefotiam, cefotetan, cefpiramide, cefminox, cefotaxime, ceftizoxime, cefoperazone, cefmenoxime, cefbuperazone, ceftazidime, cefpimizole, flomoxef, and cefuzonam. The maximum concentrations after administration of a 1-g dose in the exudate of the pelvic retroperitoneal space were 37.9 micrograms/ml with cefminox, 30.3 micrograms/ml with cefpimizole, 21.6 micrograms/ml with flomoxef, 21.5 micrograms/ml with ceftazidime, and 17.6 micrograms/ml with cefbuperazone, which were relatively high. When selecting antibiotics for prophylactic use against infections in the retroperitoneal space after radical hysterectomy and pelvic lymphadenectomy, on the basis of drug transfer, flomoxef, cefminox, cefbuperazone, ceftazidime, and cefpimizole were considered to be the drugs of first choice at a dose of 1 g. PMID:2393276

Bacteriological and virulence study of a Mycobacterium chimaera isolate from a patient in China.

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Liu, Guan; Chen, Su-Ting; Yu, Xia; Li, Yu-Xun; Ling, Ying; Dong, Ling-Ling; Zheng, Su-Hua; Huang, Hai-Rong

2015-04-01

A clinical isolate from a patient was identified as Mycobacterium chimaera, a recently identified species of nontuberculous Mycobacteria. The biochemical and molecular identity, drug sensitivity and virulence of this isolated strain were investigated. 16S rRNA, the 16S-23S ITS, hsp65 and rpoB were amplified, and their sequence similarities with other mycobacteria were analyzed. The minimum inhibitory concentrations of 22 anti-microbial agents against this isolate were established, and the virulence of the isolate was evaluated by intravenous injection into C57BL/6 mice using Mycobacterium tuberculosis H37Rv as a control strain. Growth and morphological characteristics and mycolic acid profile analysis revealed that this isolated strain was a member of the Mycobacterium avium complex. BLAST analysis of the amplified sequences showed that the isolated strain was closely related to M. chimaera. Susceptibility testing showed that the isolate was sensitive to rifabutin, rifapentine, clarithromycin, azithromycin, imipenem and cefoxitin. Bacterial load determination and tissue histopathology of the infected mice indicated that the isolate was highly virulent. The first case of M. chimaera infection in China was evaluated. The information derived from this case may offer valuable guidance for clinical diagnosis and treatment.

Berberine Enhances the Antibacterial Activity of Selected Antibiotics against Coagulase-Negative Staphylococcus Strains in Vitro

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Robert D. Wojtyczka

2014-05-01

Full Text Available Synergistic interactions between commonly used antibiotics and natural bioactive compounds may exhibit therapeutic benefits in a clinical setting. Berberine, an isoquinoline-type alkaloid isolated from many kinds of medicinal plants, has proven efficacy against a broad spectrum of microorganisms. The aim of the presented work was to assess the antibacterial activity of berberine chloride in light of the effect exerted by common antibiotics on fourteen reference strains of Staphylococccus spp., and to evaluate the magnitude of interactions of berberine with these antistaphylococcal antibiotics. In our study minimum inhibitory concentrations (MIC of berberine chloride against CoNS ranged from 16 to 512 µg/mL. The most noticeable effects were observed for S. haemolyticus ATCC 29970, S. epidermidis ATCC 12228, S. capitis subsp. capitis ATCC 35661, S. galinarium ATCC 700401, S. hominis subsp. hominis ATCC 27844, S. intermedius ATCC 29663 and S. lugdunensis ATCC 49576. The most significant synergistic effect was noticed for berberine in combination with linezolid, cefoxitin and erythromycin. The synergy between berberine and antibiotics demonstrates the potential application of compound combinations as an efficient, novel therapeutic tool for antibiotic-resistant bacterial infections.

Berberine enhances the antibacterial activity of selected antibiotics against coagulase-negative Staphylococcus strains in vitro.

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Wojtyczka, Robert D; Dziedzic, Arkadiusz; Kępa, Małgorzata; Kubina, Robert; Kabała-Dzik, Agata; Mularz, Tomasz; Idzik, Danuta

2014-05-22

Synergistic interactions between commonly used antibiotics and natural bioactive compounds may exhibit therapeutic benefits in a clinical setting. Berberine, an isoquinoline-type alkaloid isolated from many kinds of medicinal plants, has proven efficacy against a broad spectrum of microorganisms. The aim of the presented work was to assess the antibacterial activity of berberine chloride in light of the effect exerted by common antibiotics on fourteen reference strains of Staphylococccus spp., and to evaluate the magnitude of interactions of berberine with these antistaphylococcal antibiotics. In our study minimum inhibitory concentrations (MIC) of berberine chloride against CoNS ranged from 16 to 512 µg/mL. The most noticeable effects were observed for S. haemolyticus ATCC 29970, S. epidermidis ATCC 12228, S. capitis subsp. capitis ATCC 35661, S. galinarium ATCC 700401, S. hominis subsp. hominis ATCC 27844, S. intermedius ATCC 29663 and S. lugdunensis ATCC 49576. The most significant synergistic effect was noticed for berberine in combination with linezolid, cefoxitin and erythromycin. The synergy between berberine and antibiotics demonstrates the potential application of compound combinations as an efficient, novel therapeutic tool for antibiotic-resistant bacterial infections.

Prevalence of Post-operative Wound Infections in Rural area of Latur District

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Vikram Rajput

2015-08-01

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.

Detection of AmpC β lactamases in gram-negative bacteria

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Gunjan Gupta

2014-01-01

Full Text Available Amp C β-lactamases are clinically important cephalosporinases encoded on the chromosomes of many Enterobacteriaceae and a few other organisms, where they mediate resistance to cephalothin, cefazolin, cefoxitin, most penicillins, and β-lactamase inhibitor/β-lactam combinations. The increase in antibiotic resistance among Gram-negative bacteria is a notable example of how bacteria can procure, maintain and express new genetic information that can confer resistance to one or several antibiotics. Detection of organisms producing these enzymes can be difficult, because their presence does not always produce a resistant phenotype on conventional disc diffusion or automated susceptibility testing methods. These enzymes are often associated with potentially fatal laboratory reports of false susceptibility to β-lactams phenotypically. With the world-wide increase in the occurrence, types and rate of dissemination of these enzymes, their early detection is critical. AmpC β-lactamases show tremendous variation in geographic distribution. Thus, their accurate detection and characterization are important from epidemiological, clinical, laboratory, and infection control point of view. This document describes the methods for detection for AmpC β-lactamases, which can be adopted by routine diagnostic laboratories.

Investigation of susceptibility of Staphylococcus species to some antibacterial drugs by disk diffusion and broth microdilution

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Ašanin Jelena

2012-01-01

Full Text Available The objective of this work was to identify isolated Staphylococcus species and to investigate their sensitivity to some antibacterial drugs. The material used for these investigations were Staphylococcus isolates originating from milk samples. A total of 25 strains of Staphylococcus isolates were examined, including 24 from milk samples from cows with mastitis, and one strain was isolated from a milk sample from a cow following treatment for mastitis. For primary identification, catalase and oxidase tests were used, as well as the free coagulase test. Following the preliminary tests, the isolated strains were identified using commercial systems ID32 STAPH (bioMérieux, France and the BBL Crystal Gram-Positive ID Kit (Becton Dickinson, USA according to the enclosed instructions. The Staphylococcus isolates were examined for sensitivity to the following: oxacillin, penicillin, cefoxitin, gentamicin, erythromycin, chloramphenicol, tetracycline, ciprofloxacin, sulfametoxazol/trimetoprim, and vacomycin using the disk diffusion method and the broth microdilution method as recommended by the Clinical and Laboratory Strandards Institute - CLSI(2003, and the results were interpreted according to CLSI recommendations from 2008 and 2010. Antibiogram disks manufactured by Becton Dickinson (USA were used, and the broth microdilution method was applied using pure antibiotic substances from different manufacturers: erythromycin, chloramphenicol, cefoxitin, gentamicin, oxacillin, tetracycline (Sigma Aldrich, USA, sulfametoxazol (Fluka, USA, penicillin (Calbiochem, Germany, vancomycin (Abbott laboratories, USA, ciprofloxacin and trimetoprim (Zdravlje A.D., Serbia. All 25 strains were catalase positive and oxidase negative. Of the 25 strains, 19 were coagulase positive and 6 were coagulase negative.With the implementation of the disk diffusion method on 19 strains of S. aureus, 17 were established to be resistant to penicillin (89.5%, and 2 strains to gentamicin

Plasmid-mediated AmpC beta-lactamase-producing Escherichia coli causing urinary tract infection in the Auckland community likely to be resistant to commonly prescribed antimicrobials.

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Drinkovic, Dragana; Morris, Arthur J; Dyet, Kristin; Bakker, Sarah; Heffernan, Helen

2015-03-13

To estimate the prevalence and characterise plasmid-mediated AmpC beta-lactamase (PMACBL)- producing Escherichia coli in the Auckland community. All cefoxitin non-susceptible (NS) E. coli identified at the two Auckland community laboratories between 1 January and 31 August 2011 were referred to ESR for boronic acid double-disc synergy testing, to detect the production of AmpC beta-lactamase, and polymerase chain reaction (PCR) to identify the presence of PMACBL genes. PMACBL-producing isolates were typed using pulsed-field gel electrophoresis (PFGE), and PCR was used to determine their phylogenetic group and to identify multilocus sequence type (ST)131. Antimicrobial susceptibility testing and detection of extended-spectrum beta-lactamases (ESBLs) were performed according to the Clinical and Laboratory Standards Institute recommendations. 101 (51%) and 74 (37%) of 200 non-duplicate cefoxitin-NS E. coli were PMACBL producers or assumed hyper-producers of chromosomal AmpC beta-lactamase, respectively. The prevalence of PMACBL-producing E. coli was 0.4%. PMACBL-producing E. coli were significantly less susceptible to norfloxacin, trimethoprim and nitrofurantoin than E. coli that produced neither a PMACBL nor an ESBL. Very few (4%) PMACBL-producing E. coli co-produced an ESBL. Most (88%) of the PMACBL-producing isolates had a CMY-2-like PMACBL. The PMACBL-producing E. coli isolates were diverse based on their PFGE profiles, 44% belonged to phylogenetic group D, and only four were ST131. 100 of the 101 PMACBL-producing E. coli were cultured from urine, and were causing urinary tract infection (UTI) in the majority of patients. The median patient age was 56 years and most (94%) of the patients were women. A greater proportion of patients with community-acquired UTI caused by PMACBL-producing E. coli received a beta-lactam antimicrobial than patients with community-acquired UTI caused by other non-AmpC, non-ESBL-producing E. coli. Thirty-six (43%) patients with community

Long-Term Evolution Studies of E. Coli under Combined Effects of Simulated Microgravity and Antibiotic.

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Karouia, Fathi; Tirumalai, Madhan R.; Ott, Mark C.; Pierson, Duane L.; Fox, George E.; Tran, Quyen

2016-07-01

, Cefoxitin and Tetracycline), even after 11 cycles of 'erasure' of the 'adaptation memory' - this 'erasure' was accomplished by re-growing the evolved cells under shaker flask conditions and 1 cycle equals 10 generations. In the case of the cells evolved using heat sterilized HARVs, no resistance was observed to any of the an-tibiotics used (Ampicillin, Amoxicillin/Clavulanic Acid, Piperacillin/Tazobactam, Cefalotin, Cefazolin, Cefuroxime, Cefuroxime Axetil, Cefoxitin, Cefpodox-ime, Ceftazidime, Ceftriaxone, Cefepime, Gentamicin, Tobramycin, Ciprofloxacin, Levofloxacin, Norfloxacin, Tetracycline, Nitrofurantoin, and Trimethoprim/Sulfamethoxazole), even after 1000 generations of growth under LSMMG. Competition experiments using an isogenic pair revealed that the adaptive advantage of the 1000G strain (in both cases) over an unexposed strain was rapidly eliminated. While this obviously implies that the adaptation was primarily environmental rather than genomic, the levels of antibiotic resistance observed to be consistently maintained, raises the concern of persistent resistance conferred to bacterial communities through exposure to antibiotics on space missions. Supported by grants from the Center for Bionanotechnology and Environmental Research at Texas Southern University (NASA Cooperative Agreement NNX08B4A47A).

Staphylococcus lugdunensis: um olhar diferenciado no laboratório clínico Staphylococcus lugdunensis: a different view in the clinical laboratory

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Alessandro Conrado de Oliveira Silveira

2011-04-01

may be mistakenly identified as S. aureus when using rapid identification tests, such as clumping factor in slide coagulase or in agglutination latex tests. It is easily identified through available biochemical tests, such as the presence of ornithine decarboxylase and pyrrolidonyl arylamidase (PYR. It presents sensitivity to most antimicrobial agents. Furthermore, the presence of beta-lactamase and mecA gene should be routinely investigated by testing with chromogenic cephalosporin and cefoxitin susceptibility, respectively. It is convenient to highlight that the interpretative criteria used to evaluate cefoxitin sensitivity are the same recommended for S. aureus and different from those used for other CNS. Despite the fact it is atypical, S. lugdunensis is a virulent pathogen, which must be accurately identified insofar as it will rarely be deemed as a contaminant when isolated from sterile sites.

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

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E. Dahdouh

2014-01-01

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.

Mycoplasma genitalium: An Emerging Cause of Pelvic Inflammatory Disease

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Catherine L. Haggerty

2011-01-01

Full Text Available Mycoplasma genitalium is a sexually transmitted pathogen that is increasingly identified among women with pelvic inflammatory disease (PID. Although Chlamydia trachomatis and Neisseria gonorrhoeae frequently cause PID, up to 70% of cases have an unidentified etiology. This paper summarizes evidence linking M. genitalium to PID and its long-term reproductive sequelae. Several PCR studies have demonstrated that M. genitalium is associated with PID, independent of gonococcal and chlamydial infection. Most have been cross-sectional, although one prospective investigation suggested that M. genitalium was associated with over a thirteenfold risk of endometritis. Further, a nested case-control posttermination study demonstrated a sixfold increased risk of PID among M. genitalium positive patients. Whether or not M. genitalium upper genital tract infection results in long-term reproductive morbidity is unclear, although tubal factor infertility patients have been found to have elevated M. genitalium antibodies. Several lines of evidence suggest that M. genitalium is likely resistant to many frequently used PID treatment regimens. Correspondingly, M. genitalium has been associated with treatment failure following cefoxitin and doxycycline treatment for clinically suspected PID. Collectively, strong evidence suggests that M. genitalium is associated with PID. Further study of M. genitalium upper genital tract infection diagnosis, treatment and long-term sequelae is warranted.

Rapid screening of pyogenic Staphylococcus aureus for confirmation of genus and species, methicillin resistance and virulence factors by using two novel multiplex PCR.

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Haque, Abdul; Haque, Asma; Saeed, Muhammad; Azhar, Aysha; Rasool, Samreen; Shan, Sidra; Ehsan, Beenish; Nisar, Zohaib

2017-01-01

Emergence of methicillin resistant Staphylococcus aureus (MRSA) is a major medical problem of current era. These bacteria are resistant to most drugs and rapid diagnosis can provide a clear guideline to clinicians. They possess specific virulence factors and relevant information can be very useful. We designed this study to develop multiplex PCRs to provide rapid information. We studied 60 Staphylococcus aureus isolates and detected methicillin resistance by cefoxitin sensitivity and targeting of mecA gene. After initial studies with uniplex PCRs we optimized two multiplex PCRs with highly reproducible results. The first multiplex PCR was developed to confirm genus, species and methicillin resistance simultaneously, and the second multiplex PCR was for screening of virulence factors. We found 38.33% isolates as methicillin resistant. α -toxin, the major cytotoxic factor, was detected in 40% whereas β-hemolysin was found in 25% cases. Panton Valentine leucocidin was detected in 8.33% and toxic shock syndrome toxin in5% cases. The results of uniplex and multiplex PCRs were highly compatible. These two multiplex PCRs when run simultaneously can provide vital information about methicillin resistance and virulence status of the isolate within a few hours as compared to several days needed by routine procedures.

Prevalence of Bacterial Vaginosis and Associated Risk Factors among Women Complaining of Genital Tract Infection.

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Bitew, Adane; Abebaw, Yeshiwork; Bekele, Delayehu; Mihret, Amete

2017-01-01

Bacterial vaginosis is a global concern due to the increased risk of acquisition of sexually transmitted infections. To determine the prevalence of bacterial vaginosis and bacteria causing aerobic vaginitis. A cross-sectional study was conducted among 210 patients between September 2015 and July 2016 at St. Paul's Hospital. Gram-stained vaginal swabs were examined microscopically and graded as per Nugent's procedure. Bacteria causing aerobic vaginitis were characterized, and their antimicrobial susceptibility pattern was determined. The overall prevalence of bacterial vaginosis was 48.6%. Bacterial vaginosis was significantly associated with number of pants used per day ( p = 0.001) and frequency of vaginal bathing ( p = 0.045). Of 151 bacterial isolates, 69.5% were Gram-negative and 30.5% were Gram-positive bacteria. The overall drug resistance level of Gram-positive bacteria was high against penicillin, tetracycline, and erythromycin. Cefoxitin and tobramycin were the most active drugs against Gram-positive bacteria. The overall drug resistance level of Gram-negative bacteria was high against tetracycline, ampicillin, and amoxicillin. Amikacin and tobramycin were the most active drugs against Gram-negative bacteria. The prevalence of bacterial vaginosis was high and was affected by individual hygiene. Routine culture of vaginal samples should be performed on patients with vaginitis and the drug susceptibility pattern of each isolate should be determined.

A Case Study on Soil Antibiotic Resistome in an Urban Community Garden.

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Mafiz, Abdullah Ibn; Perera, Liyanage Nirasha; He, Yingshu; Zhang, Wei; Xiao, Shujie; Hao, Weilong; Sun, Shi; Zhou, Kequan; Zhang, Yifan

2018-05-29

Urban agricultural soils can be an important reservoir of antibiotic resistance and have great food safety and public health indications. This study was to investigate antibiotic-resistant bacteria and antibiotic resistance genes in urban agricultural soils using phenotypic and metagenomic tools. A total of 207 soil bacteria were recovered from 41 soil samples collected from an urban agricultural garden in Detroit, USA. The most prevalent antibiotic resistance phenotypes demonstrated by Gram-negative bacteria was the resistance to ampicillin (94.2%), followed by chloramphenicol (80.0%), cefoxitin (79.5%), gentamicin (78.4%), and ceftriaxone (71.1%). Gram-positive bacteria were all resistant to gentamicin, kanamycin, and penicillin. Genes encoding resistance to quinolone, β-lactam, and tetracycline were the most prevalent and abundant in the soil. qepA and tetA, both encoding efflux pumps, predominated in quinolone and tetracycline resistance genes tested, respectively. Positive correlation (p < 0.05) was identified among groups of antibiotic resistance genes and between antibiotic resistance genes and metal resistance genes. The data demonstrated a diverse population of antibiotic resistance in urban agricultural soils. Phenotypic determination together with soil metagenomics proved to be a valuable tool to study the nature and extent of antibiotic resistance in the environment. Copyright © 2018. Published by Elsevier B.V.

Evaluation of different phenotypic methods for detection of amp c beta-lactamase producing bacteria in clinical isolates

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Hassan, A.; Usman, J.; Kalim, F.; Gill, M.M.; Khalid, A.; Iqbal, M.; Ingram, P.

2013-01-01

To compare the sensitivity and specificity of different phenotypic methods for detection of Amp C betalactamase producing bacteria. Study Design: Analytical study. Place and Duration of Study: Department of Microbiology, Army Medical College / National University of Sciences and Technology (NUST), Islamabad, Pakistan, from June 2010 to December 2010. Methodology: A total of 150 clinical isolates were screened for presence of Amp C beta-lactamase by using the cefoxitin disc. The confirmatory methods evaluated were inhibitor based assay (boronic acid), Amp C disc test and Amp C Etest. Three dimensional enzyme extract assay was used as the reference method for determining the sensitivity and specificity. Results: Among the total isolates tested, 62.8% bacteria showed the presence of Amp C beta-lactamase by standard three dimensional enzyme extract assay. Among the three methods compared, boronic acid disk test found out to be highly sensitive (88%) and specific (92%) for the detection of Amp C beta-lactamase producing bacteria. Conclusion: Detection of Amp C production is crucial in order to establish the antibiotic therapy and to attain the favourable clinical outcomes. Implementation of simple tests like boronic acid disk tests in the laboratories will help to alleviate the spread of Amp C beta-lactamase harboring organisms. (author)

Antimicrobial susceptibility pattern in nosocomial infections caused by Acinetobacter species in Asir Region, Saudi Arabia.

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Abdalla, Nazar M; Osman, Amani A; Haimour, Waleed O; Sarhan, Mohammed A A; Mohammed, Mohammed N; Zyad, Eyhab M; Al-Ghtani, Abdalla M

2013-03-15

This study aimed at evaluating the sensitivity of antibiotics towards nosocomial infections caused by Acinetobacter species. The study took place during the period Dec. 2011- Dec. 2012 at Assir Central Hospital in collaboration with the department of microbiology, college of medicine, King Khalid University, Abha. A prospective study involving 150 patients presented with nosocomial infections due to Acinetobacter species detected by bacteriological tests; direct microscopy, culture in blood agar media, fermentation test in MacConkey media and MIC (minimum inhibitory concentration) for antibiotics sensitivity using Muller Hinton media and Chemical test using API 20. A 150 nosocomial infections in this study showed gram-negative coccobacilli, non motile, glucose-negative fermentor and oxidase negative. All isolates showed 100% sensitivity to: Imipramine, Meropenem, Colistin. From the rest of tested antibiotics the higher resistant ones were; Nitrofurantoin 87% and Cefoxitin 85%. The least resistant antibiotics; Imipenem 3% and Ticarcillin 7%. While variable resistance in the rest of tested antimicrobials. A 47 patients (31.3%) have used antibiotics prior to this study. The high rate of usage occurred in elder patients. The frequency of Acinetobacter calcoaceticus baumannii complex multi-drugs resistance ABCMDR is rising including almost all commonly used antibiotics. Only few antibiotics exert 100% sensitivity towards these bacteria.

Antibacterial Activity of Protocatechuic Acid Ethyl Ester on Staphylococcus aureus Clinical Strains Alone and in Combination with Antistaphylococcal Drugs

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Maria Miklasińska

2015-07-01

Full Text Available The aim of the presented study was to examine in vitro the antibacterial activity of protocatechuic acid ethyl ester (ethyl 3,4-dihydroxybenzoate, EDHB against Staphylococcus aureus clinical isolates alone and in the combination with four selected antibiotics. The EDHB antimicrobial activity was tested against twenty S. aureus strains isolated from the clinical samples, and three reference strains. The phenotypes and genotypes of resistance to methicillin for the tested strains were defined as well as the phenotypic resistance to macrolides, lincosamides and streptogramin B (MLSB. EDHB displayed diverse activity against examined S. aureus strains with the minimal inhibitory concentration (MIC within the range from 64 to 1024 µg/mL. Addition of ¼ MIC of EDHB into the Mueller-Hinton Agar (MHA resulted in augmented antibacterial effect in the presence of clindamycin. In the case of cefoxitin no synergistic effect with EDHB was noted. For erythromycin and vancomycin the decrease of mean MICs in the presence of EDHB was observed but did not reach statistical significance. The results of the present study showed that in vitro EDHB possesses antibacterial activity against S. aureus clinical strains and triggers a synergistic antimicrobial effect with clindamycin and to the lesser extent with erythromycin and vancomycin.

Global Phenotypic Characterization of Effects of Fluoroquinolone Resistance Selection on the Metabolic Activities and Drug Susceptibilities of Clostridium perfringens Strains

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Miseon Park

2014-01-01

Full Text Available Fluoroquinolone resistance affects toxin production of Clostridium perfringens strains differently. To investigate the effect of fluoroquinolone resistance selection on global changes in metabolic activities and drug susceptibilities, four C. perfringens strains and their norfloxacin-, ciprofloxacin-, and gatifloxacin-resistant mutants were compared in nearly 2000 assays, using phenotype microarray plates. Variations among mutant strains resulting from resistance selection were observed in all aspects of metabolism. Carbon utilization, pH range, osmotic tolerance, and chemical sensitivity of resistant strains were affected differently in the resistant mutants depending on both the bacterial genotype and the fluoroquinolone to which the bacterium was resistant. The susceptibilities to gentamicin and erythromycin of all resistant mutants except one increased, but some resistant strains were less susceptible to amoxicillin, cefoxitin, ceftriaxone, chloramphenicol, and metronidazole than their wild types. Sensitivity to ethidium bromide decreased in some resistant mutants and increased in others. Microarray analysis of two gatifloxacin-resistant mutants showed changes in metabolic activities that were correlated with altered expression of various genes. Both the chemical structures of fluoroquinolones and the genomic makeup of the wild types influenced the changes found in resistant mutants, which may explain some inconsistent reports of the effects of therapeutic use of fluoroquinolones on clinical isolates of bacteria.

Risk factors assessment for nasal colonization of Staphylococcus aureus and its methicillin resistant strains among pre-clinical medical students of Nepal.

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Ansari, Shamshul; Gautam, Rajendra; Shrestha, Sony; Ansari, Safiur Rahman; Subedi, Shankar Nanda; Chhetri, Muni Raj

2016-04-12

Staphylococcus aureus (S. aureus), a normal flora of nasal cavity, can cause minor to life threatening invasive diseases and nosocomial infections. Methicillin resistant strains of S. aureus are causing a great challenge for treatment options. Therefore, the purpose of this study was to assess the nasal carriage rate of S. aureus, its methicillin resistant strains and risk factors in medical students prior to clinical exposure. The bacterial growth of S. aureus from nasal swab culture was identified by using standard microbiological methods recommended by American Society for Microbiology. Modified Kirby-Bauer disk diffusion method was used for antibiotic susceptibility testing and methicillin resistance was confirmed using cefoxitin and oxacillin disks. D-zone test method was used to determine the inducible clindamycin resistance. Among 200 participants, nasal carriage of S. aureus was detected from 30 (15%) subjects. Upper respiratory tract infections significantly (P aureus and their methicillin resistant strains. All of the isolates were reported to be susceptible to vancomycin and teicoplanin. S. aureus strains detected from 8 (4%) students were confirmed to be methicillin resistant. The result of our study demands for strict policy to screen all the students for nasal carriage of S. aureus and its MRSA strains to minimize the transmission of this organism from community to hospital settings.

Prevalence of methicillin resistant Staphylococcus aureus in Lumbini Medical College and Teaching Hospital, Palpa, Western Nepal.

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Raut, Shristi; Bajracharya, Kishor; Adhikari, Janak; Pant, Sushama Suresh; Adhikari, Bipin

2017-06-02

Multidrug resistant Staphylococcus aureus is common in both tertiary and primary health care settings. Emergence of methicillin resistance in S. aureus (MRSA) along with macrolide, lincosamide, streptogramin B (MLSB) has made treatment of Staphylococcal infection more challenging. The main objective of this study was to detect MRSA, MLSB (inducible; MLSBi and constitutive; MLSBc) resistant S. aureus using phenotypic methods and to determine their antibiogram. Various samples were collected from 1981 patients who attended Lumbini Medical College and Teaching Hospital (LMCTH) during the period of 6 months from September 2015 to February 2016. Out of a total of 1981 samples, 133 S. aureus were isolated. Cefoxitin was used to detect MRSA by the disk diffusion test. Inducible clindamycin resistance (MLSBi) was detected by the D-zone test. The antibiotic profile of all isolates was tested by a modified Kirby Bauer disk diffusion method. Among 133 S. aureus, there were 58 (43.6%) MRSA, 34 (25.6%) MLSBi and 30 (22.6%) MLSBc. Of a total of 64 MLSB, a significant proportion (62.5%) was MRSA (p aureus, MRSA showed significant resistance to 9 (p resistance to multiple antibiotics (p resistance profiles from this study can optimize the treatment of multi-drug resistant S. aureus.

Perfil de susceptibilidade a antimicrobianos em amostras de cocos Gram-positivos, catalase negativos, isoladas de mastite subclínica bubalina Profile of antimicrobial susceptibility in strains of Gram positive cocos, negative catalase, isolated from buffalo subclinical mastitis

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Maria C.E. Vianni

2003-06-01

the State of Rio de Janeiro. The test used was diffusion of disks in agar Müller Hinton, according to recommendations of the National Committee for Clinical Laboratory Standards - NCCLS. There were tested disks with ampicillin (10mg, cefalotin (30mg, cefotaxime (30mg, cefoxitin (30mg, cloranfenicol (30mg, eritromycin (15mg, gentamycin (10mg, nitrofurantoin (300mg, norfloxacin (10mg, penicillin (10 IU, tetracyclin (30mg and vancomycin (30mg. The results showed that with Lactococcus garvieae, the most efficient antimicrobial was nitrofurantoin, revealing 85.71% sensibility, followed by cefotaxime (61.90%, vancomycin (52.38%, norfloxacin (47.62& and cefalotin (47.62%. The highest resistance was developed against penicillin and ampicillin, with 95.24% resistance for the two antimicrobials. The susceptibility profile developed by the strains of Enterococcus gallinarum showed low sensibility against the tested antimicrobials; the highest resistance observed was against eritromycin and gentamycin, with 33.34% sensibility for both. The antimicrobial evaluation showed 100% resistance against vancomycin and tetracyclin, followed by cloranfenicol, penicillin, ampicillin, cefoxitin, cefotaxim, norfloxacin and nitrofurantoin; all of them showed a resistance of 83.33% with the samples tested.

ß-lactamasas AmpC plasmídicas tipo CMY-2 emergentes en Tucumán, Argentina CMY-2-type plasmid-mediated AmpC ß-Lactamases emerging in Tucumán, Argentina

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María A. Jure

2011-03-01

. Susceptibility testing was performed by disk diffusion; one P. mirabilis and three E. coli strains showed resistance to cephamycins (cefoxitin and C3G. An E-test to determine MIC and a synergy test by aminophenylboronic disks were performed. Enzymatic activity against cefoxitin was confirmed by a microbiological assay. A polymerase chain reaction (PCR for the detection of plasmid-mediated ampC genes of different groups was performed and a 462-bp amplicon was obtained when using primers directed against the CIT group; the obtained sequences were compared to blaCMY-2 sequences, showing 100% identity. The emergence of CMY-2-type plasmid-mediated AmpC ß-lactamases indicated the importance of implementing systematic monitoring of these resistances to avoid potential clinical and epidemiological consequences.

FEATURES OF THE LARGE INTESTINE MICROFLORA OF CHILDREN – DONOR LIVER TRANSPLANT RECIPIENTS

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N. I. Gabrielyan

2013-01-01

Full Text Available Aim. The study microecology of the large intestine of children with cirrhosis before transplantation of the share liver. Materials and methods. Studied the flora of the colon 157 children of 1 to 17 years admitted to hospital for liver transplantation fragment from a related donor. Identification was carried out using microbial panels BD Crystal and databases BBL Crystal MIND. Methicillin-resistant staphylococci were determined by their sensiti- vity to oxacillin and cefoxitin. Beta-lactamase activity was tested using discs with ceftazidime and ceftazidime/ clavulanic acid. Results. Microecological revealed deep irregularities in the large intestine transplantation in children up lobe of the liver on a spectrum and composition of the microflora. Among the resident microflora decreased levels of bifidobacteria, lactobacilli and coliform bacteria, especially in children under one year. A sig- nificant portion of the children surveyed (over 60–70% had an increase of frequency of finding stateally bacteria, especially Klebsiella and enterobacteria in third children – non-fermenting bacteria – Pseudomonas and Acine- tobacter spp. Revealed the spread of strains of gram-negative bacteria with extended-spectrum betalaktamaz.Conclusion. Expressed microecological violations in the large intestine in children with higher levels of bac- teria are conditionally risk factor reeks of infectious complications in the postoperative period and require are complex tools to assist in eliminatsii.s given antibiotic resistance of bacteria. 

Study on Prevalence, Antibiotic Susceptibility, and tuf Gene Sequence-Based Genotyping of Species-Level of Coagulase-Negative Staphylococcus Isolated From Keratitis Caused by Using Soft Contact Lenses.

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Faghri, Jamshid; Zandi, Alireza; Peiman, Alireza; Fazeli, Hossein; Esfahani, Bahram Nasr; Safaei, Hajieh Ghasemian; Hosseini, Nafiseh Sadat; Mobasherizadeh, Sina; Sedighi, Mansour; Burbur, Samaneh; Oryan, Golfam

2016-03-01

To study on antibiotic susceptibility and identify coagulase-negative Staphylococcus (CoNS) species based on tuf gene sequencing from keratitis followed by using soft contact lenses in Isfahan, Iran, 2013. This study examined 77 keratitis cases. The samples were cultured and the isolation of CoNS was done by phenotypic tests, and in vitro sensitivity testing was done by Kirby-Bauer disk diffusion susceptibility method. Thirty-eight of isolates were conveniently identified as CoNS. In this study, 27 (71.1%), 21 (55.3%), and 16 (42.1%) were resistant to penicillin, erythromycin, and tetracycline, respectively. One hundred percent of isolates were sensitive to gentamicin, and 36 (94.7%) and 33 (86.8%) of isolates were sensitive to chloramphenicol and ciprofloxacin, respectively. Also, resistances to cefoxitin were 7 (18.4%). Analysis of tuf gene proved to be discriminative and sensitive in which all the isolates were identified with 99.0% similarity to reference strains, and Staphylococcus epidermidis had the highest prevalence among other species. Results of this study showed that CoNS are the most common agents causing contact lens-associated microbial keratitis, and the tuf gene sequencing analysis is a reliable method for distinguishing CoNS species. Also gentamycin, chloramphenicol, and ciprofloxacin are more effective than the other antibacterial agents against these types of bacteria.

[Antimicrobial susceptibility and drug-resistance genes of Yersinia spp. of retailed poultry in 4 provinces of China].

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Peng, Z X; Zou, M Y; Xu, J; Guan, W Y; Li, Y; Liu, D R; Zhang, S S; Hao, Q; Yan, S F; Wang, W; Yu, D M; Li, F Q

2018-04-06

Objective: To monitor the antimicrobial resistance and drug-resistance genes of Yersinia enterocolitis , Y. intermedia and Y. frederiksenii recovered from retailed fresh poultry of 4 provinces of China. Methods: The susceptibility of 25 isolated Yersinia spp. to 14 classes and 25 kinds of antibiotics was determined by broth microdilution method according to CLSI (Clinical and Laboratory Standards Institute). The antibiotic resistance genes were predicted with antibiotic resistance genes database (ARDB) using whole genome sequences of Yersinia spp. Results: In all 22 Y. enterocolitis tested, 63.7% (14 isolates), 22.8% (5 isolates), 4.6% and 4.6% of 1 isolates exhibited the resistance to cefoxitin, ampicillin-sulbactam, nitrofurantoin and trimethoprim-sulfamethoxazole, respectively. All the 25 isolates were multi-drug resistant to more than 3 antibiotics, while 64.0% of isolates were resistant to more than 4 antibiotics. A few Y. enterocolitis isolates of this study were intermediate to ceftriaxone and ciprofloxacin. Most Yersinia spp. isolates contained antibiotic resistance genes mdtG, ksgA, bacA, blaA, rosAB and acrB , and 5 isolates recovered from fresh chicken also contained dfrA 1, catB 2 and ant 3 ia . Conclusion: The multi-drug resistant Yersinia spp. isolated from retailed fresh poultry is very serious in the 4 provinces of China, and their contained many kinds of drug-resistance genes.

CHARACTERIZATION OF EXTENDED-SPECTRUM Β-LACTAMASE-PRODUCING ESCHERICHIA COLI STRAINS ISOLATED FROM DAIRY PRODUCTS

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Rahem Khoshbakht

2014-02-01

Full Text Available Extended-spectrum β-lactamases (ESBLs are enzymes that hydrolyze the β-lactam ring, and ESBL-producing E. coli has rapidly spread worldwide with pose a serious hazard for humans. The aim of this study was to determine the prevalence of ESBL producing E. coli and molecular evaluation of four ESBL-associated genes among E. coli strains isolated from milk and cheese in southern Iran. Antibiotic susceptibility test was carried out for a total of 150 isolates of E. coli, previously collected from dairy products. ESBL production was screened using a double-disc synergy test (DDST and presence of four ESBL genes (PER, VEB, TEM and CTX-M was tested using PCR. Among 150 E. coli strains 57 (38% isolates were identified as ESBL-producing strains. All ESBL positive isolates could be typed for one or more genes and the most prevalent ESBL-associated gene was CTX-M (80.7%. The PER gene was not present among isolates. Isolates showed high susceptibility to imipe¬nem and cefoxitin. The results showed the high prevalence of ESBL producing E. coli strains among dairy products and high occurrence of CTX-M-associated ESBL activity among isolates indicating the hazards of increasing the strains with antibiotic resistance which can transfer to human trough the dairy food products.

Bacteriological Profile and Antimicrobial Susceptibility Patterns of Bacteria Isolated from Pus/Wound Swab Samples from Children Attending a Tertiary Care Hospital in Kathmandu, Nepal

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Salu Rai

2017-01-01

Full Text Available In Nepal, little is known about the microbiological profile of wound infections in children and their antimicrobial susceptibility patterns. Total of 450 pus/wound swab samples collected were cultured using standard microbiological techniques and the colonies grown were identified with the help of biochemical tests. The antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique. Methicillin-resistant Staphylococcus aureus isolates were detected by using cefoxitin disc and confirmed by determining minimum inhibitory concentrations (MIC of oxacillin. 264 (59% samples were culture positive. The highest incidence of bacterial infections was noted in the age group of less than 1 year (76%. Out of 264 growth positive samples, Gram-positive bacteria were isolated from 162 (61% samples and Gram-negative bacteria were found in 102 (39% samples. Staphylococcus aureus (99% was the predominant Gram-positive bacteria isolated and Pseudomonas aeruginosa (44% was predominant Gram-negative bacteria. About 19% of S. aureus isolates were found to be methicillin-resistant MIC of oxacillin ranging from 4 μg/mL to 128 μg/mL. Among the children of Nepal, those of age less than 1 year were at higher risk of wound infections by bacteria. Staphylococcus aureus followed by Pseudomonas aeruginosa were the most common bacteria causing wound infections in children.

Phenotypic and Genotypic Antibiotic Resistance of Salmonella from Chicken Carcasses Marketed at Ibague, Colombia

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D Cortes Vélez

Full Text Available ABSTRACT Salmonella enterica is responsible for alimentary toxic infections associated with the consumption of contaminated poultry products and the antimicrobial resistant patterns of Salmonella circulating in the Tolima region are currently unknown. To address this issue, both the phenotype and genotype antibiotic resistance patterns of 47 Salmonella isolated from raw chicken carcasses sold at the Ibague city were analyzed by the disc diffusion, microdilution and PCR assays. All 47 Salmonella isolates showed resistance to five or more antimicrobial agents. Resistance to Ampicillin (AMP, Amikacin (AMK, Gentamicin (GEN, Tobramycin (TOB, Cefazoline (CFZ, Cefoxitin (FOX, Nitrofurantoin (NIT, Trimethoprim-Sulfamethoxazole (SXT, Tetracycline (TET, Ciprofloxacin (CIP and Enrofloxacin (ENR was observed in 42.35% of Salmonella isolates. All tested S. Paratyphi B var Java isolates showed resistance to at least 12 antibiotics. S. Hvittingfoss showed resistance to 5 antibiotics, whereas S. Muenster showed resistance to seven antibiotics. Amplification of a number of antibiotic resistance genes showed that blaTEM (100% correlated well with resistance to Ampicilin and Cephalosporin, whereas aadB (87% correlated well with resistance to Aminoglycosides. It is concluded that Salmonella isolated from raw chicken meat marketed at Ibague showed MDR by both phenotypic and genotypic methods and they may represent an important threat to human health. Additional studies are needed to establish the relationship between antibiotic resistance in Salmonella from poultry products and clinical isolates.

Angina monocitica con sovrainfezione da Prevotella denticola: caso clinico

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Maria Teresa Allù

2005-06-01

Full Text Available Monocytic angina with superinfection of Prevotella denticola: clinical case Monocytic angina is a clinical sindrome caused by Epstein-Barr virus characterized by fever, pharyngitis, exudative tonsillitis, swollen lymphoglands, splenomegaly and hepatomegaly.The inflamed pharynx and necrotic tonsils of infectious mononucleosis are subject to bacterial superinfection initially or during the course of the illness; the reduced PO2 tension and low oxidation-reduction potential that prevail in a vascular and necrotic tissues favour the growth of anaerobes. In this article we reported the clinical case of a ten years old children, who presented fever and tonsillopharyngitis; he was treated with cefotaxime and piperacillin, he did not improve in health. He was admitted to hospital (Department of Otorhinolaryngology. The patient was treated with aminoglycoside (tobramycin, piperacillin and cortisone; the clinical situation deteriorated. Pus sample was collected from the tonsils and cultured. Isolated strain from culture anaerobic was identified biochemically (Rapid-ID32ANA.The microorganism isolated was: Prevotella denticola (oral anaerobic gram-negative rods; β-lactamase production was tested by using the chromogenic cephalosporin disk test.The susceptibility to antibiotics was performed according to NCCLS recommendations. Prevotella denticola (β-lactamase production was resistant to penicillin, cefoxitin, cefotetan, piperacillin, clindamycin and metronidazole it was susceptible to piperacillin-tazobactam, amoxicillin-clavulanate, ticarcillin-clavulanate, imipenem and chloramphenicol. Children was treated with piperacillin-tazobactam, with rapid symptomatic relief.

Heavy metal and antibiotic resistance in bacteria isolated from the environment of swine farms

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Fan, Y.; Ping, C.; Mei, L.S.

2014-01-01

The aim of the present study was to determine the level of heavy metal resistance and antibiotic resistance patterns of bacterial isolates from environment of swine farms in China. A total of 284 bacteria were isolated, 158 from manure, 62 from soil and 64 from wastewater in different swine farm samples. All the isolates were tested for resistant against eight heavy metals. From the total of 284 isolates, maximum bacterial isolates were found to be resistant to Zn/sup 2+/ (98.6%) followed by Cu/sup 2+/ (97.5%), Cd/sup 2+/ (68.3%), Mn/sup 2+/ (60.2%), Pb/sup 2+/(51.4%), Ni/sup 2+/(41.5%) and Cr/sup 2+/(45.1%). However, most of the isolates were sensitive to Co/sup 2+/. Meanwhile,all the isolates were tested for sensitively to nine antibiotics. The results shows that most isolates were sensitive to cefoxitin and oxacillin, but resistance to tetracycline, ampicillin, gentamicin, amikacin, erythromycin, clindamycin were widespread. Multiple resistant to metals and antibiotics were also observed in this study. Most isolates were tolerant to different concentrations of various heavy metals and antibiotics. Our results confirmed that environment of swine farms in China has a significant proportion of heavy metal and antibiotic resistant bacteria, and these bacteria constitute a potential risk for swine health and public health. (author)

Prevalence and characterization of Staphylococcus aureus and Staphylococcus pseudintermedius isolated from companion animals and environment in the veterinary teaching hospital in Zambia, Africa.

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Youn, Jung-Ho; Park, Yong Ho; Hang'ombe, Bernard; Sugimoto, Chihiro

2014-03-01

The Republic of Zambia consists of only one veterinary teaching school at the University of Zambia (UNZA) where students and veterinarians are exposed to many bacterial pathogens including Staphylococcus aureus (SA) and Staphylococcus pseudintermedius (SP). The aim of this study was the characterization and antimicrobial susceptibility profile of eleven SA and 48 SP isolates from the veterinary hospitals' in- and outpatients and the environment. No isolate was resistant to cefoxitin by disk diffusion test and the corresponding resistance gene mecA was not found. In contrast, the resistance rates of SA to penicillin (63.6%) and trimethoprim-sulfamethoxazole (36.4%) and SP to penicillin (52.1%) and tetracycline (25.0%) were the highest. A variety of sequence types (STs) without a predominant type including numerous novel types were determined, especially for SP (39.6%). The spa typing provided a clonal assignment for all SAs (100%) and 24 SPs (50%) with three and two novel types, respectively. This study has provided an overview of SA and SP in the veterinary teaching hospital at UNZA. However, for a better understanding of these species regarding pathogenesis and transmission, further studies on the prevalence and characterization of SA and SP from veterinary staff, pet owners, and farm animals in Zambia is needed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Genotypic relatedness and antimicrobial resistance of Salmonella Heidelberg isolated from chickens and turkeys in the midwestern United States.

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Nisar, Muhammad; Kassem, Issmat I; Rajashekara, Gireesh; Goyal, Sagar M; Lauer, Dale; Voss, Shauna; Nagaraja, Kakambi V

2017-05-01

Salmonella is one of the most common causes of foodborne illnesses in humans in the United States, and domestic poultry is considered an important source of this pathogen. Salmonella enterica subsp. enterica serovar Heidelberg is the fourth most commonly reported Salmonella from retail meats and food animals in the United States. We assessed the genotypes and antimicrobial resistance phenotypes of Salmonella Heidelberg isolated from various chicken and turkey hatcheries and breeder farms in the Midwest. The genotypes of 33 S. Heidelberg isolates from chickens ( n = 19) and turkeys ( n = 14) were compared using pulsed-field gel electrophoresis analysis. Cluster analysis of the fingerprints showed that the majority of the chicken isolates grouped together with 87% similarity; those from turkeys clustered with 88% similarity. Similarity between chicken and turkey isolates was also high (86%). Isolates from turkeys were generally more genetically diverse than those from chickens. Antimicrobial susceptibility analysis detected resistance to sulfisoxazole (36% of the isolates), streptomycin (33%), gentamicin (27%), tetracycline (24%), ampicillin and amoxicillin-clavulanic acid (15%), cefoxitin (12%), ceftriaxone and ceftiofur (12%), and chloramphenicol (9%). None of the isolates was resistant to azithromycin, ciprofloxacin, or nalidixic acid. Although the number of the isolates was limited in our study, we conclude that S. Heidelberg isolates from the same host generally clustered together and that a considerable number of the isolates were resistant to a number of antimicrobial agents.

Antimicrobial Susceptibility of Microorganisms Isolated from Orofacial Infections

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Sinan TOZOĞLU

2010-05-01

Full Text Available Objectives: The purpose of this study was to determine an effective antimicrobial therapy ofcausative agents for orofacial abscesses. In order to do that, bacterial strains isolated from patientsamples were identified based on “bacterial fatty acid profiles” and determined the antimicrobialsusceptibilities by using disc diffusion test for aerobic bacteria, and E test for anaerobic bacteria.Materials and Methods: The present study was carried out in 71 patients with a diagnosis oforofacial infections in Oral and Maxillofacial Surgery Clinic of Atatürk University. Aerobic andanaerobic bacteria were isolated from 71 clinical specimens by Microbial Identification Systemand their antibiotic sensitivity was tested. Results: The most frequently isolated species were Streptococcus spp., Staphylococcus spp.and Bacteroides spp. The highest rate of resistance was detected in the aerobic strains againstpenicillin (58.4%, followed by eriythromycin (46.7%, clindamycin (35.1%, tetracycline(32.5%, amoxycillin/clavulonic acid (31.1% and cefazoline (27.3%, respectively. The highestrate of resistance was detected in the anaerobic strains against to penicillin (60%, clindamycin(53.3%, metronidazole (30%, cefoxitin (20% piperacillin/tazobactam (11.6% and imipenem(0.3%, respectively. Conclusions: In order to treat orofacial infections more effectively, and to prevent antimicrobialresistance which has increased recently, antibiotic susceptility tests should be performedroutinely in regions where antibacterial resistance is high like our area.

Antimicrobial resistance and typing of Salmonella isolated from street vended foods and associated environment.

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Anukampa; Shagufta, Bi; Sivakumar, M; Kumar, Surender; Agarwal, Rajesh Kumar; Bhilegaonkar, Kiran Narayan; Kumar, Ashok; Dubal, Zunjar Baburao

2017-07-01

The present study was carried out to find out the occurrence and types of Salmonella present in street vended foods and associated environment, and their resistance pattern against various antibiotics. About 1075 street vended food and associated environment samples were processed for isolation and confirmation of different Salmonella spp. by targeting gene specific inv A gene and serotype specific Sdf I, Via B and Spy genes by PCR. Selected Salmonella isolates were screened for antibiotic resistance by using Baeur-Kirby disk diffusion test. Out of 1075 samples, only 31 (2.88%) isolates could be amplified the inv A gene of which 19 could be recovered from meat vendors; 8 from egg vendors while remaining 4 from milk vendors. Though, majority of Salmonella recovered from raw foods the ready-to-eat food like chicken gravy and rasmalai also showed its presence which pose a serious public health threat. Overall, 19, 6 and 1 isolates of S. Typhimurium, S. Enteritidis and S. Typhi could be detected by PCR while remaining 5 isolates could not be amplified suggesting other type of Salmonella. Selected Salmonella isolates were completely resistance to Oxacillin (100%) followed by Cefoxitin (30.43%) and Ampicillin (26.10%). Thus, it is observed that the street vended foods of animal origin and associated environment play an important role in transmission of food borne pathogens including Salmonella .

Effects of beta-lactamases and omp mutation on susceptibility to beta-lactam antibiotics in Escherichia coli.

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Hiraoka, M; Okamoto, R; Inoue, M; Mitsuhashi, S

1989-01-01

Four types of beta-lactamases consisting of a penicillinase type I (TEM-1), a penicillinase type II (OXA-1), a cephalosporinase of Citrobacter freundii, and a cephalosporinase of Proteus vulgaris were introduced into Escherichia coli MC4100 and its omp mutants, MH1160 (MC4100 ompR1) and MH760 (MC4100 ompR2), by transformation. Effects of the combination of the omp mutations and these beta-lactamases on the susceptibility of E. coli strains were studied with 15 beta-lactam antibiotics including cephalosporins, cephamycins, penicillins, imipenem, and aztreonam. The ompR1 mutant, MH1160, lacks OmpF and OmpC, and it showed reduced susceptibility to 11 of the 15 beta-lactam agents. The reduction in susceptibility to cefoxitin, moxalactam, and flomoxef was much greater than reduction in susceptibility to the other agents. When the ompR1 mutant produced the cephalosporinase of C. freundii, the susceptibility of the mutant to 12 of the 15 beta-lactam antibiotics decreased. The reduction in susceptibility of MH1160 to 10 of the 12 agents affected by the enzyme was two- to fourfold greater than that observed in MC4100. Such a synergistic effect was also observed with the cephalosporinase of P. vulgaris and ompR1 mutation against six cephalosporins, moxalactam, and aztreonam. Images PMID:2658786

Characterization of Coagulase-Negative Staphylococci and pheno-genotypic beta lactam resistance evaluation in samples from bovine Intramammary infection

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D.A. Melo

Full Text Available ABSTRACT This study aimed to identify Coagulase-Negative Staphylococci (CoNS species isolated from bovine mastitis, through phenotypic and PCR-RFLP (Restriction Fragment Length Polymorphism-Polimerase Chain Reaction methods and to compare both techniques to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS technique. Among them, the PCR-RFLP method, using a partially conserved sequence of the groEL gene, is a promising alternative, because of its reproducibility and reliability. On the other hand, the proteomic technique MALDI-TOF MS provides an accurate and much faster diagnosis and has been increasingly employed in microbiological identification. The pheno-genotypic profiles of beta-lactam resistance were also investigated, this characterization is important, considering that the use of antimicrobials is a key element for mastitis control in dairy farms. The concordance of the phenotypic, PCR-RFLP and MALDI-TOF MS assays to identify CoNS species was 77,5% (31/40. S. chromogenes was the species most frequently isolated. Antibiotic resistance rate was relatively low, registering values of 25.5% to penicillin, 9.6% to oxacillin and 6.2% to cefoxitin. Resistance to imipenem, cephalotin and amoxicillin+clavulanate was not observed. The mecA gene and its variant were detected in 7.6% and 4,1% of the isolates respectively. The blaZ gene was found in 43.2% of the strains resistant to penicillin.

Impairments of mecA gene detection in bovine Staphylococcus spp.

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Dayanne Araújo de Melo

2014-09-01

Full Text Available Staphylococcus aureus antimicrobial resistance, especially to beta-lactams, favors treatment failures and its persistence in herd environment. This work aimed to develop a more specific primer for mecA gene detection based on the comparison of the conserved regions from distinct host origins and also investigated the presence of homologue mecA LGA251 in bovine strains. A total of 43 Staphylococcus spp. were included in this study, comprising 38 bovine S. aureus, two human and three equine coagulase-negative staphylococci (CNS. Phenotypical methicillin-resistance detection was performed through oxacillin agar-screening and cefoxitin disk-diffusion test. None isolate tested positive for mecA LGA251 gene. For mecA gene PCR, new primers were designed based on the sequences of human S. aureus (HE681097 and bovine S. sciuri (AY820253 mecA. The new primers based on the S. aureus mecA sequence amplified fragments of human and equine CNS and the ones based on S. sciuri mecA sequence only yielded fragments for S. aureus bovine strains. Multiples alignments of mecA gene sequences from bovine, human and equine revealed punctual but significant differences in bovine strains that can lead to the mecA gene detection impairment. The observed divergences of mecA gene sequences are not a matter of animal or human origin, it is a specificity of bovine samples.

Epidemiology, Clinical Characteristics, and Antimicrobial Susceptibility Profiles of Human Clinical Isolates of Staphylococcus intermedius Group.

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Yarbrough, Melanie L; Lainhart, William; Burnham, C A

2018-03-01

The veterinary pathogens in the Staphylococcus intermedius group (SIG) are increasingly recognized as causes of human infection. Shared features between SIG and Staphylococcus aureus may result in the misidentification of SIG in human clinical cultures. This study examined the clinical and microbiological characteristics of isolates recovered at a tertiary-care academic medical center. From 2013 to 2015, 81 SIG isolates were recovered from 62 patients. Patients were commonly ≥50 years old, diabetic, and/or immunocompromised. Documentation of dog exposure in the electronic medical record was not common. Of the 81 SIG isolates, common sites of isolation included 37 (46%) isolates from wound cultures and 17 (21%) isolates from respiratory specimens. Although less common, 10 (12%) bloodstream infections were documented in 7 unique patients. The majority of SIG (65%) isolates were obtained from polymicrobial cultures. In comparison to S. aureus isolates from the same time period, significant differences were noted in proportion of SIG isolates that were susceptible to doxycycline (74% versus 97%, respectively; P SIG isolates. All MR isolates detected by an oxacillin disk diffusion test would have been misclassified as methicillin susceptible using a cefoxitin disk diffusion test. Thus, SIG is recovered from human clinical specimens, and distinction of SIG from S. aureus is critical for the accurate characterization of MR status in these isolates. Copyright © 2018 American Society for Microbiology.

Variable selection in near infrared spectroscopy for quantitative models of homologous analogs of cephalosporins

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Yan-Chun Feng

2014-07-01

Full Text Available Two universal spectral ranges (4550–4100 cm-1 and 6190–5510 cm-1 for construction of quantitative models of homologous analogs of cephalosporins were proposed by evaluating the performance of five spectral ranges and their combinations, using three data sets of cephalosporins for injection, i.e., cefuroxime sodium, ceftriaxone sodium and cefoperazone sodium. Subsequently, the proposed ranges were validated by using eight calibration sets of other homologous analogs of cephalosporins for injection, namely cefmenoxime hydrochloride, ceftezole sodium, cefmetazole, cefoxitin sodium, cefotaxime sodium, cefradine, cephazolin sodium and ceftizoxime sodium. All the constructed quantitative models for the eight kinds of cephalosporins using these universal ranges could fulfill the requirements for quick quantification. After that, competitive adaptive reweighted sampling (CARS algorithm and infrared (IR–near infrared (NIR two-dimensional (2D correlation spectral analysis were used to determine the scientific basis of these two spectral ranges as the universal regions for the construction of quantitative models of cephalosporins. The CARS algorithm demonstrated that the ranges of 4550–4100 cm-1 and 6190–5510 cm-1 included some key wavenumbers which could be attributed to content changes of cephalosporins. The IR–NIR 2D spectral analysis showed that certain wavenumbers in these two regions have strong correlations to the structures of those cephalosporins that were easy to degrade.

Prevalence of Bacterial Vaginosis and Associated Risk Factors among Women Complaining of Genital Tract Infection

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Adane Bitew

2017-01-01

Full Text Available Background. Bacterial vaginosis is a global concern due to the increased risk of acquisition of sexually transmitted infections. Objectives. To determine the prevalence of bacterial vaginosis and bacteria causing aerobic vaginitis. Methods. A cross-sectional study was conducted among 210 patients between September 2015 and July 2016 at St. Paul’s Hospital. Gram-stained vaginal swabs were examined microscopically and graded as per Nugent’s procedure. Bacteria causing aerobic vaginitis were characterized, and their antimicrobial susceptibility pattern was determined. Results. The overall prevalence of bacterial vaginosis was 48.6%. Bacterial vaginosis was significantly associated with number of pants used per day (p=0.001 and frequency of vaginal bathing (p=0.045. Of 151 bacterial isolates, 69.5% were Gram-negative and 30.5% were Gram-positive bacteria. The overall drug resistance level of Gram-positive bacteria was high against penicillin, tetracycline, and erythromycin. Cefoxitin and tobramycin were the most active drugs against Gram-positive bacteria. The overall drug resistance level of Gram-negative bacteria was high against tetracycline, ampicillin, and amoxicillin. Amikacin and tobramycin were the most active drugs against Gram-negative bacteria. Conclusions. The prevalence of bacterial vaginosis was high and was affected by individual hygiene. Routine culture of vaginal samples should be performed on patients with vaginitis and the drug susceptibility pattern of each isolate should be determined.

Inducible Clindamycin Resistance in Staphylococcus Species

International Nuclear Information System (INIS)

Afridi, F. I.; Zeb, M.; Farooqi, B. J.; Murtaza, G.; Hussain, A.

2014-01-01

Objective: To determine the frequency of inducible clindamycin resistance in clinical isolates of Staphylococcus species by phenotypic D-test. Study Design: Observational study. Place and Duration of Study: Ziauddin University Hospital, Karachi, from July to December 2011. Methodology: Consecutive clinical isolates of Staphylococcus species were collected and identified by conventional microbiological techniques. Antimicrobial susceptibility testing and inducible clindamycin resistance was carried out by performing D-test using CLSI criteria. Methicillin resistance was detected by using Cefoxitin disk as a surrogate marker. Statistical analysis was performed by SPSS version-17. Results: A total of 667 clinical isolates of Staphylococcus species were obtained during the study period. In these isolates, 177 (26.5%) were Staphylococcus aureus, and 490 (73.5%) were coagulase negative Staphylococci. The total frequency of inducible clindamycin resistance among isolates of Staphylococcus species was 120/667 (18%). Frequency of inducible clindamycin resistance among coagulase negative Staphylococci group and Staphylococcus aureus group were 18.57% and 16.38% respectively. Median age of patients in D-test positive group was 19.5 (1 - 54) years. Conclusion: The frequency of inducible clindamycin resistance among Staphylococcus species may differ in different hospital setup. Clinical microbiology laboratories should implement testing simple and effective D-test on all Staphylococcus species. D-test positive isolates should be reported clindamycin resistant to decrease treatment failure. (author)

Yersinia enterocolitica strains associated with human infections in Switzerland 2001-2010.

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Fredriksson-Ahomaa, M; Cernela, N; Hächler, H; Stephan, R

2012-07-01

Yersinia enterocolitica infections are common in humans. However, very scarce data are available on the different biotypes and virulence factors of human strains, which has proved to be problematic to assess the clinical significance of the isolated strains. In this study, the presence of the ail gene and distribution of different bio- and serotypes among human Y. enterocolitica strains and their possible relation to the genotype and antimicrobial resistance were studied. In total, 128 Y. enterocolitica strains isolated from human clinical samples in Switzerland during 2001-2010 were characterised. Most (75 out of 128) of the Y. enterocolitica strains belonged to biotypes 2, 3 or 4 and carried the ail gene. One of the 51 strains that belonged to biotype 1A was also ail positive. Most of the ail-positive strains belonged to bioserotype 4/O:3 (47 out of 76) followed by 2/O:9 (22 out of 76). Strains of bioserotype 4/O:3 were dominant among patients between 20 and 40 years old and strains of biotype 1A dominate in patients over 40 years. Strains belonging to biotypes 2, 3 and 4, which all carried the ail gene, exhibited a high homogeneity with PFGE typing. Y. enterocolitica 2/O:5,27 and 2/O:9 strains showed resistance to amoxicillin/clavulanic acid and cefoxitin, but Y. enterocolitica 4/O:3 strains did not.

Evaluation of probiotic potential of lactic acid bacteria to reduce in vitro cholesterol

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Clementina Cueto

2012-03-01

Full Text Available Daily consumption of probiotics reduce levels of serum cholesterol by up to 3%, which is significant to prevent hypercholesterolemia, a risk factor for cardiovascular disease and cause of mortality. The genus Lactobacillus is used in industry as a probiotic and some species reduce serum cholesterol by two mechanisms, the adsorption of cholesterol and the production of the enzyme bile salt hydrolase, which vary according to species. The aim of the study was to assess the ability of probiotic bacteria group isolated from coast serum. 53 strains were isolated from nine coastal serum sample; the sensitivity to cefoxitin and vancomycin, and the tolerance to pH 2.0 and 0.3% bile salts were evaluated to determine its probiotic potential. Five microorganisms were selected and molecularly identified as Lactobacillus fermentum. The ability to absorb cholesterol measured by the method of Kimoto, showed a reduction of 53.06 ± 2.69 µg.mL-1 for strain K73 and 7.23 ± 2.69 µg. mL-1 for K75. These same strains showed the highest total and specific activity of the enzyme. The results didn´t show a relationship between the production of enzyme and adsorption of cholesterol. The strain with the greatest probiotic potential was K73. This hypocholesterolemic property will give strains added value to start the search for food matrices that allow decreasing serum cholesterol levels.

Misidentification of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals in Tripoli, Libya

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Ahmed, Mohamed O.; Abuzweda, Abdulbaset R.; Alghazali, Mohamed H.; Elramalli, Asma K.; Amri, Samira G.; Aghila, Ezzeddin Sh.; Abouzeed, Yousef M.

2010-01-01

Background Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial (hospital-acquired) pathogen of exceptional concern. It is responsible for life-threatening infections in both the hospital and the community. Aims To determine the frequency of MRSA misidentification in hospitals in Tripoli, Libya using current testing methods. Methods One hundred and seventy S. aureus isolates previously identified as MRSA were obtained from three hospitals in Tripoli. All isolates were reidentified by culturing on mannitol salt agar, API 20 Staph System and retested for resistance to methicillin using the cefoxitin disk diffusion susceptibility test and PBP2a. D-tests and vancomycin E-tests (Van-E-tests) were also performed for vancomycin-resistant isolates. Results Of the 170 isolates examined, 86 (51%) were confirmed as MRSA (i.e. 49% were misidentified as MRSA). Fifteen (17%) of the confirmed MRSA strains exhibited inducible clindamycin resistance. Of the 86 confirmed MRSA isolates, 13 (15%) were resistant to mupirocin, 53 (62%) were resistant to ciprofloxacin, 41 (48%) were resistant to trimethoprim-sulfamethoxazole, and none were resistant to linezolid. Although disc-diffusion testing indicated that 23 (27%) of the isolates were resistant to vancomycin, none of the isolates were vancomycin-resistant by Van-E-test. Conclusions Misidentification of nosocomial S. aureus as MRSA is a serious problem in Libyan hospitals. There is an urgent need for the proper training of microbiology laboratory technicians in standard antimicrobial susceptibility procedures and the implementation of quality control programs in microbiology laboratories of Libyan hospitals. PMID:21483574

Antimicrobial resistance trends among Salmonella isolates obtained from horses in the northeastern United States (2001-2013).

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Cummings, Kevin J; Perkins, Gillian A; Khatibzadeh, Sarah M; Warnick, Lorin D; Aprea, Victor A; Altier, Craig

2016-05-01

OBJECTIVE To describe the antimicrobial resistance patterns of Salmonella isolates obtained from horses in the northeastern United States and to identify trends in resistance to select antimicrobials over time. SAMPLE 462 Salmonella isolates from horses. PROCEDURES Retrospective data were collected for all Salmonella isolates obtained from equine specimens that were submitted to the Cornell University Animal Health Diagnostic Center between January 1, 2001, and December 31, 2013. Temporal trends in the prevalence of resistant Salmonella isolates were investigated for each of 13 antimicrobials by use of the Cochran-Armitage trend test. RESULTS The prevalence of resistant isolates varied among antimicrobials and ranged from 0% (imipenem) to 51.5% (chloramphenicol). During the observation period, the prevalence of resistant isolates decreased significantly for amoxicillin-clavulanic acid, ampicillin, cefazolin, cefoxitin, ceftiofur, chloramphenicol, and tetracycline and remained negligible for amikacin and enrofloxacin. Of the 337 isolates for which the susceptibility to all 13 antimicrobials was determined, 138 (40.9%) were pansusceptible and 192 (57.0%) were multidrug resistant (resistant to ≥ 3 antimicrobial classes). The most common serovar isolated was Salmonella Newport, and although the annual prevalence of that serovar decreased significantly over time, that decrease had only a minimal effect on the observed antimicrobial resistance trends. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that current antimicrobial use in horses is not promoting the emergence and dissemination of antimicrobial-resistant Salmonella strains in the region served by the laboratory.

Detection of Genes for Superantigen Toxins in Methicillin-Resistant Staphylococcus aureus Clinical Isolates in Karachi

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Taj, Y.; Fatima, I.; Ali, S. W.; Kazmi, S. U.

2014-01-01

Objective: To detect genes for enterotoxins, exfoliative and toxic shock syndrome toxins in Staphylococcus aureus (S. aureus) strains isolated from clinical specimens. Study Design: Cross-sectional observational study. Place and Duration of Study: Department of Molecular Genetics, Dr. Ziauddin Hospital, Karachi, from January to December 2010. Methodology: Two hundred and ninety eight S. aureus clinical isolates were obtained from various clinical samples received at Dr. Ziauddin Hospital, Karachi. Out of these, 115 were detected as methicillin resistant (MRSA) by cefoxitin disk diffusion test showing a prevalence rate of 38.6%. Detection of individual toxin genes was performed by Polymerase Chain Reaction (PCR) by using only one primer pair for each tube. Uniplex primers were preferred as multiplex primers are longer in base pairs and have the potential for cross reaction due to non-specific binding and increase in optimization time. Results: The possession of a single gene or more than a single gene in MRSA isolates was found in 61.73% of clinical samples; the highest number was found in pus swab, followed by sputum, blood, urethral swab, and urine. The prevalence of toxin genes was higher in MRSA as compared to methicillin sensitive (MSSA) isolates (19.12%). Conclusion: PCR detects strains possessing toxin genes independent of their expression. The possession of genes for super-antigens seems to be a frequent and habitual trait of S. aureus more so in MRSA. (author)

Activities of beta-lactam antibiotics against Escherichia coli strains producing extended-spectrum beta-lactamases.

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Jacoby, G A; Carreras, I

1990-01-01

Seven extended-spectrum beta-lactamases related to TEM and four enzymes derived from SHV-1 were transferred to a common Escherichia coli host so that the activity of a variety of beta-lactams could be tested in a uniform genetic environment. For most derivatives, penicillinase activity was 10% or less than that of strains making TEM-1, TEM-2, or SHV-1 beta-lactamase, suggesting that reduced catalytic efficiency accompanied the broader substrate spectrum. Despite this deficit, resistance to aztreonam, carumonam, cefdinir, cefepime, cefixime, cefmenoxime, cefotaxime, cefotiam, cefpirome, cefpodoxime, ceftazidime, ceftibuten, ceftizoxime, ceftriaxone, cefuroxime, and E1040 was enhanced. For strains producing TEM-type enzymes, however, MICs of carumonam, cefepime, cefmenoxime, cefotiam, cefpirome, and ceftibuten were 8 micrograms/ml or less. Susceptibilities of cefmetazole, cefotetan, cefoxitin, flomoxef, imipenem, meropenem, moxalactam, temocillin, FCE 22101, and Sch 34343 were unaffected. FCE 22101, imipenem, meropenem, and Sch 34343 were inhibitory for all strains at 1 microgram/ml or less. In E. coli an OmpF- porin mutation in combination with an extended-spectrum beta-lactamase enhanced resistance to many of these agents, but generally by only fourfold. Hyperproduction of chromosomal AmpC beta-lactamase increased resistance to 7-alpha-methoxy beta-lactams but not that to temocillin. When tested at 8 micrograms/ml, clavulanate was more potent than sulbactam or tazobactam in overcoming resistance to ampicillin, while cefoperazone-sulbactam was more active than ticarcillin-clavulanate or piperacillin-tazobactam, especially against TEM-type extended-spectrum beta-lactamases. PMID:2193623

Rapidly growing mycobacteria in Singapore, 2006-2011.

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Tang, S S; Lye, D C; Jureen, R; Sng, L-H; Hsu, L Y

2015-03-01

Nontuberculous mycobacteria infection is a growing global concern, but data from Asia are limited. This study aimed to describe the distribution and antibiotic susceptibility profiles of rapidly growing mycobacterium (RGM) isolates in Singapore. Clinical RGM isolates with antibiotic susceptibility tests performed between 2006 and 2011 were identified using microbiology laboratory databases and minimum inhibitory concentrations of amikacin, cefoxitin, clarithromycin, ciprofloxacin, doxycycline, imipenem, linezolid, moxifloxacin, sulfamethoxazole or trimethoprim-sulfamethoxazole, tigecycline and tobramycin were recorded. Regression analysis was performed to detect changes in antibiotic susceptibility patterns over time. A total of 427 isolates were included. Of these, 277 (65%) were from respiratory specimens, 42 (10%) were related to skin and soft tissue infections and 36 (8%) were recovered from blood specimens. The two most common species identified were Mycobacterium abscessus (73%) and Mycobacterium fortuitum group (22%), with amikacin and clarithromycin being most active against the former, and quinolones and trimethoprim-sulfamethoxazole against the latter. Decreases in susceptibility of M. abscessus to linezolid by 8.8% per year (p 0.001), M. fortuitum group to imipenem by 9.5% per year (p 0.023) and clarithromycin by 4.7% per year (p 0.033) were observed. M. abscessus in respiratory specimens is the most common RGM identified in Singapore. Antibiotic options for treatment of RGM infections are increasingly limited. Copyright © 2014 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Microbiological and molecular characterization of human clinical isolates of Staphylococcus cohnii, Staphylococcus hominis, and Staphylococcus sciuri.

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Garza-González, Elvira; Morfin-Otero, Rayo; Martínez-Vázquez, Manuel A; Gonzalez-Diaz, Esteban; González-Santiago, Omar; Rodríguez-Noriega, Eduardo

2011-12-01

The incidence of coagulase-negative staphylococci reported as causative agents of nosocomial infections has risen in the last decade. The aim of this study was to characterize biofilm formation, antibiotic resistance, SCCmec type, and genetic relatedness in clinical isolates of Staphylococcus cohnii, Staphylococcus hominis, and Staphylococcus sciuri recovered from humans. Clinically relevant isolates of S. cohnii (n = 15), S. hominis (n = 9), and S. sciuri (n = 6), were collected from patients. Biofilm formation was evaluated using crystal violet staining, drug susceptibility was assessed using the broth microdilution method, and methicillin resistance was measured using the cefoxitin disk test. SCCmec was typed using 2 different methodologies, and genetic relatedness was determined by pulsed-field gel electrophoresis (PFGE). Sixty percent (9/15) of S. cohnii, 33% (3/9) of S. hominis, and 50% (3/6) of S. sciuri isolates were categorized as weak producers of biofilm. None of the isolates were resistant to vancomycin or linezolid. All 3 species showed a high resistance (> 66%) to ampicillin, levofloxacin, erythromycin, and ceftriaxone, and the majority of the isolates were methicillin-resistant. PFGE revealed that the S. cohnii isolates comprised 1 dominant clone. The S. cohnii, S. hominis, and S. sciuri isolates analyzed in this study showed a high methicillin resistance and resistance to other antimicrobials. The results of this study strongly suggest that coagulase-negative staphylococci harbour new SCCmec elements. We report the first case of a clone of S. cohnii associated with human disease.

The antimicrobial susceptibility profile of ESKAPE pathogens from urinary tract infections in a referral laboratory, Northeast Iran

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Mohammad Salehi

2016-11-01

Full Text Available Objective: To assess the antimicrobial susceptibility pattern of ESKAPE pathogens from Neyshabur, Iran during 2013–2015. Methods: A total of 345 isolates including 62 Staphylococcus aureus (S. aureus, 38 Enterobacter spp. (including 14 Enterobacter agglomerans, 6 Enterobacter aerogenes and other 18 Enterobacter spp., 123 Enterococcus faecium, 78 Klebsiella pneumonia, 10 Pseudomonas aeruginosa and 34 Acinetobacter baumannii were isolated. The antimicrobial susceptibility pattern of isolates was conducted with Kirby Bauer method. Data were analyzed with SPSS 20.0 software using F- and t-tests. Results: Among S. aureus isolates, the highest resistance was observed against nalidixic acid (81.35% and cefixime (74.50%. Thirty-three (53.22% S. aureus isolates were cefoxitin resistant (methicillin-resistant S. aureus. The majority of Enterobacter species was resistant to amikacin (100.00% and cephalotin (66.60%. Most Enterococcus faecium isolates were resistant to nalidixic acid (89.43% and amikacin (83.33%, but vancomycin-resistant enterococci isolates were not detected. Moreover, among Klebsiella pneumonia, the highest resistance was observed to nalidixic acid (20.98% and cotrimoxazole (28.39%. Furthermore, all Pseudomonas aeruginosa isolates were resistant to cefotaxime (100.00% and majority to nitroforantoin (88.80%. Acinetobacter baumannii isolates showed the highest and the lowest resistance to cefotaxime (100.00% and cefixime (88.71%, respectively. Conclusions: The prevalence of ESKAPE pathogens from northeast region was low, but majority of them exhibited high rate of antibiotic resistance to common used antimicrobial agents.

In vitro susceptibility of chloramphenicol against methicillin-resistant staphylococcus aureus

International Nuclear Information System (INIS)

Fayyaz, M.; Mirza, I.A.; Hussain, A.; Abbasi, S.A.; Ali, S.; Ahmed, Z.

2013-01-01

To determine the in vitro susceptibility of chloramphenicol against methicillin-resistant Staphylococcus aureus. Study Design: Cross-sectional study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, from January to June 2012. Methodology: One hundred and seventy four isolates of methicillin-resistant Staphylococcus aureus were included in this study using cefoxitin (30 A g) disc for detection. Minimum inhibitory concentration (MIC) of chloramphenicol against MRSA was determined by using E-strip (AB BIO DISK). The susceptibility was determined by swabbing the Mueller-Hinton agar (MHA) plates with the resultant saline suspension of MRSA and applying E-strip of chloramphenicol from AB Biodisk Sweden and determining the MIC of chloramphenicol (in A g/ml). Clinical and Laboratory Standards Institute (CLSI) recommendations of A=8 A g/ml being sensitive, 16 A g/ml as intermediate and A 32 A g/ml as resistant were followed in interpreting the results. Results: Out of the 174 MRSA isolates, 132 (75.86%) isolates were susceptible to chloramphenicol with MICs of A=8 A g/ml, 38 (21.84%) were resistant A=32 A g/ml while 4 (2.30%) were in intermediate range with MIC of 16 A g/ml. Conclusion: Chloramphenicol has shown good in vitro activity against MRSA and is likely to have a key role in the treatment of MRSA infections providing us a good alternative to newer expensive antimicrobials in resource limited countries. (author)

Assessment of antibiotic resistance of Escherichia coli isolates and screening of Salmonella spp. in wild ungulates from Portugal.

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Dias, Diana; Torres, Rita T; Kronvall, Göran; Fonseca, Carlos; Mendo, Sónia; Caetano, Tânia

2015-09-01

Antibiotic resistance is an emerging global problem. Wild animals are rarely exposed to antibiotics and therefore low levels of antibiotic resistance are expected. However, the growing interactions of these animals with humans and livestock may have a huge impact on their bacterial flora. This study aimed to assess the levels of antibiotic resistance in Escherichia coli isolated from widespread wild ungulates in Portugal. The interpretation of inhibition zone diameters was performed according to clinical breakpoints and epidemiological cut-offs, determined with the normalized resistance interpretation (NRI) method. For clinical breakpoints, 16% of the isolates were resistant to at least one antibiotic, including ampicillin (10%), tetracycline (9%), streptomycin (5%) co-trimoxazole (4%), amoxicillin/clavulanic acid (1%) and cefoxitin (1%). The levels of resistance detected in E. coli strains isolated from wild boar were statistically different for ampicillin and co-trimoxasol. According to NRI cut-offs, 10% of the population showed a non-wild-type phenotype against at least one antibiotic, also including tetracycline (9%), co-trimoxazole (6%), streptomycin (4%), ampicillin (2%) and amoxicillin/clavulanic acid (1%). Considering this parameter of comparison, no statistically different levels of resistance were identified between E. coli recovered from the three wild ungulates. Screening of Salmonella spp., which can be potentially pathogenic, was also performed, revealing that its prevalence was very low (1.5%). The study demonstrated that wild ungulates from Portugal are also reservoirs of antibiotic-resistant bacteria. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

High-dose antibiotic therapy is superior to a 3-drug combination of prostanoids and lipid A derivative in protecting irradiated canines

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Kumar, K.S.; Srinivasan, V.; Toles, R.E.; Miner, V.L.; Jackson, W.E.; Seed, T.M.

2002-01-01

There is an urgent need to develop non-toxic radioprotectors. We tested the efficacy of a 3-drug combination (3-DC) of iloprost, misoprostol, and 3D-MPL (3-deacylated monophosphoryl lipid A) and the effects of postirradiation clinical support with high doses of antibiotics and blood transfusion. Canines were given 3-DC or the vehicle and exposed to 3.4 Gy or 4.1 Gy of 60 Co radiation. Canines irradiated at 4.1 Gy were also given clinical support, which consisted of blood transfusion and antibiotics (gentamicin, and cefoxitin or cephalexin). Peripheral blood cell profile and 60-day survival were used as indices of protection. At 3.4 Gy, 3-DC- or vehicle-treated canines without postirradiation clinical support survived only for 10 to 12 days. Fifty percent of the canines treated with 3-DC or vehicle and provided postirradiation clinical support survived 4.1-Gy irradiation. Survival of canines treated with vehicle before irradiation significantly correlated with postirradiation antibiotic treatments, but not with blood transfusion. The recovery profile of peripheral blood cells in 4.1 Gy-irradiated canines treated with vehicle and antibiotics was better than drug-treated canines. These results indicate that therapy with high doses of intramuscular aminoglycoside antibiotic (gentamicin) and an oral cephalosporin (cephalexin) enhanced survival of irradiated canines. Although blood transfusion correlated with survival of 3-DC treated canines, there were no additional survivors with 3-DC treated canines than the controls. (author)

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

2007-09-01

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

Inferring the interaction structure of resistance to antimicrobials.

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Zawack, Kelson; Love, Will; Lanzas, Cristina; Booth, James G; Gröhn, Yrjö T

2018-04-01

The growth of antimicrobial resistance presents a significant threat to human and animal health. Of particular concern is multi-drug resistance, as this increases the chances an infection will be untreatable by any antibiotic. In order to understand multi-drug resistance, it is essential to understand the association between drug resistances. Pairwise associations characterize the connectivity between resistances and are useful in making decisions about courses of treatment, or the design of drug cocktails. Higher-order associations, interactions, which tie together groups of drugs can suggest commonalities in resistance mechanism and lead to their identification. To capture interactions, we apply log-linear models of contingency tables to analyze publically available data on the resistance of Escheresia coli isolated from chicken and turkey meat by the National Antimicrobial Resistance Monitoring System. Standard large sample and conditional exact testing approaches for assessing significance of parameters in these models breakdown due to structured patterns inherent to antimicrobial resistance. To address this, we adopt a Bayesian approach which reveals that E. coli resistance associations can be broken into two subnetworks. The first subnetwork is characterized by a hierarchy of β-lactams which is consistent across the chicken and turkey datasets. Tier one in this hierarchy is a near equivalency between amoxicillin-clavulanic acid, ceftriaxone and cefoxitin. Susceptibility to tier one then implies susceptibility to ceftiofur. The second subnetwork is characterized by more complex interactions between a variety of drug classes that vary between the chicken and turkey datasets. Copyright © 2018 Elsevier B.V. All rights reserved.

Survey of Staphylococcus isolates among hospital personnel, environment and their antibiogram with special emphasis on methicillin resistance

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Shobha K

2005-01-01

Full Text Available The objective of this study was to find the prevalence of Staphylococcus spp. carriage among hospital personnel and hospital environment and their antibiogram with special emphasis on methicillin resistance. A total of 205 samples from hospital personnel and environment were collected from casualty, oncology and multidisciplinary cardiac unit ward of Kasturba Medical College Hospital, Manipal. Samples were collected using sterile cotton wool swabs and inoculated into brain heart infusion broth. Subcultures were done onto blood agar and MacConkey′s agar. Isolates were identified by standard methods up to species level. Antimicrobial susceptibility test was performed according to standardized disc diffusion Kirby-Bauer method. Each of the isolates was screened for methicillin resistance using oxacillin disc on Mueller Hinton agar plate followed by MIC for methicillin and cefoxitin susceptibility test by disc diffusion method. Sixty five out of 205 strains (31.7% were Staphylococcus spp. and all of them were coagulase negative. Most of the strains belonged to S.epidermidis 49.23%(32/65 followed by S. saprophyticus 26.15%(17/65. Maximum isolates of S.epidermidis were from anterior nares 28.12%(9/32 strains of S.epidermidis . Highest number of methicillin resistant coagulase negative strains (3/9, 33.33% were isolated from stethoscope of multidisciplinary cardiac unit ward followed by carriers in the anterior nares (2/9, 22.22%. Methicillin resistant coagulase negative staphylococci are prevalent in anterior nares of hospital personnel and in the hospital environment thereby providing a definite source for hospital acquired infection. All isolates were sensitive to vancomycin, ciprofloxacin and amikacin.

Antibiotic resistance and biofilm formation among coagulase-negative staphylococci isolated from clinical samples at a tertiary care hospital of eastern Nepal.

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Shrestha, Lok Bahadur; Bhattarai, Narayan Raj; Khanal, Basudha

2017-01-01

Coagulase negative staphylococci were long regarded non-pathogenic as they are the commensals of human skin and mucosa but the recent changes in the medical practice and changes in underlying host populations, they are being considered significant pathogens associated with number of nosocomial infections. The objective of the study was to determine the species, antimicrobial susceptibility pattern, biofilm forming ability of the clinically significant CoNS isolates and to compare the different methods for the detection of biofilm formation. A total of 52 clinically significant CoNS isolates obtained from different units during a year period were studied. Characterization was done using standard microbiological guidelines and antimicrobial susceptibility was done following CLSI guidelines. Biofilm formation was detected by using three methods i.e. tissue culture plate method, congo red agar method and tube adherence method. Among 52 isolates , S. epidermidis (52%) was the most common species which was followed by S. saprophyticus (18%) and S. haemolyticus (14%). Antimicrobial susceptibility pattern of CoNS documented resistance of 80% to ampicillin. Resistance to cefoxitin and ceftriaxone was observed in 58% of the isolates. Biofilm formation was observed in 65.38% of the isolates. The accuracy of Congo red agar and tube adherence method for the detection of biofilm formation was 82% and 76% respectively. CoNS isolates obtained from clinical samples should be processed routinely and antimicrobial susceptibility testing should be performed. Multidrug-resistant CoNS are prevalent. All the three methods i.e. tissue culture plate, Congo red agar and tube adherence method can be used in detecting biofilm formation.

Retail ready-to-eat food as a potential vehicle for Staphylococcus spp. harboring antibiotic resistance genes.

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Chajęcka-Wierzchowska, Wioleta; Zadernowska, Anna; Nalepa, Beata; Sierpińska, Magda; Laniewska-Trokenheim, Lucja

2014-06-01

Ready-to-eat (RTE) food, which does not need thermal processing before consumption, could be a vehicle for the spread of antibiotic-resistant microorganisms. As part of general microbiological safety checks, staphylococci are routinely enumerated in these kinds of foods. However, the presence of antibiotic-resistant staphylococci in RTE food is not routinely investigated, and data are only available from a small number of studies. The present study evaluated the pheno- and genotypical antimicrobial resistance profile of Staphylococcus spp. isolated from 858 RTE foods (cheeses, cured meats, sausages, smoked fishes, salads). Of 113 strains isolated, S. aureus was the most prevalent species, followed by S. xylosus, S. saprophyticus, and S. epidermidis. More than half (54.9%) of the isolates were resistant to at least one class of tested antibiotic; of these, 35.4% of the strains were classified as multidrug resistant. Most of the isolates were resistant to cefoxitin (49.6%), followed by clindamycin (39.3%), tigecycline (27.4%), quinupristin-dalfopristin (22.2%), rifampin (20.5%), tetracycline (17.9%), and erythromycin (8.5%). All methicillin-resistant staphylococci harbored the mecA gene. Among the isolates resistant to at least one antibiotic, 38 harbored tetracycline resistance determinant tet (M), 24 harbored tet (L), and 9 harbored tet (K). Of the isolates positive for tet (M) genes, 34.2% were positive for the Tn916-Tn1545-like integrase family gene. Our results indicated that retail RTE food could be considered an important route for the transmission of antibiotic-resistant bacteria harboring multiple antibiotic resistance genes.

The Incidence of Nosocomial Toxigenic Clostridium difficile Associated Diarrhea in Tehran Tertiary Medical Centers

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Norakhoda Sadeghifard

2010-09-01

Full Text Available "nClostridium difficile is the most common cause of nosocomial diarrhea. It is usually a consequence of antibiotic treatment, But sporadic cases can occur. This study was aimed to determine the frequency of the nosocomial Clostridium difficile (C. difficile associated diarrhea in Tehran University of Medical Sciences hospitals and study of antibacterial susceptibility of isolates. In this study a total of 942 stool samples from patients with nosocomial diarrhea that were hospitalized in Imam Khomeini hospital, Shariati hospital and Children clinical center were collected. The samples were cultured on a selective cycloserine cefoxitin fructose agar (CCFA and incubated in anaerobic conditions, at 37°C for 5 days. Isolates were characterized to species level by conventional biochemical tests. Bacterial cytotoxicity was assayed on tissue culture (vero. Antimicrobial sensitivity of isolated toxigenic C. difficile were investigated by kirby Beuer method (disk diffusion. Our findings show that, of the total patients, 57 toxigenic C. difficile (6.1% were isolated. Results of statistical analysis show significant differences between the rate of isolated toxigenic C. difficile and age group of patients (P<0.05. Among the wards of selected hospitals, in gastroenterology of Children clinical center, Toxigenic C. difficile was isolated from patients most frequently. The sensitivity of isolates to vancomycin, Chloramphenicol and ceftriaxone were higher than other antibiotics. Toxigenic C. difficile is a common hospital-acquired infection. The organism was found in 6.1% hospitalized patients. Further studies to evaluate the rate and role of toxigenic C. difficile in nosocomial diarrheal processes, ecological and pathogenic terms are suggested.

Occurrence and antimicrobial susceptibility of Salmonella isolates recovered from the pig slaughter process in Romania.

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Morar, Adriana; Sala, Claudia; Imre, Kálmán

2015-01-15

Reported human salmonellosis cases have increased in Romania. Antibiotic susceptibility testing of Salmonella strains isolated from pork and chicken meat indicate a worrying multidrug resistance pattern. This study aimed to investigate the occurrence of Salmonella and to evaluate the antibiotic resistance of Salmonella strains in a pig slaughterhouse-processing complex, which receives animals from 30% of the large industrialized swine farms in Romania. A total of 108 samples, including pork (n = 47), packaged pork products (n = 44), scald water sludge (n = 8), and detritus from the hair removal machine of the slaughterhouse (n = 9) were examined for the presence of Salmonella through standard methods. The antibiotic susceptibility of the isolated strains to 17 antibiotics was tested using the Vitek 2 system. Twenty-six (24.1%) samples were found to be Salmonella positive; this included 25.5% of meat samples and 15.9% of packaged products, as well as samples from two different points of the slaughter (41.2%). Resistance was observed against tetracycline (61.5%), ampicillin (50%), piperacillin (50%), trimethoprim-sulfamethoxazole (34.6%), amoxicillin/clavulanic acid (26.9%), nitrofurantion (23.1%), cefazolin (15.4%), piperacillin/tazobactam (7.7%), imipenem (3.8%), ciprofloxacin (3.8%), and norfloxacin (3.8%). No resistance towards cefoxitin, cefotaxime, ceftazidime, cefepime, amikacin, and gentamicin was found. Our study demonstrated the occurrence of multidrug-resistant Salmonella strains in the investigated pork production complex and highlighted it as a potential source of human infections. The results demonstrate the seriousness of antibiotic resistance of Salmonella in Romania, while providing a useful insight for the treatment of human salmonellosis by specialists.

Molecular Typing and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolated from Bovine Milk in Tanzania.

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Mohammed, Jibril; Ziwa, Michael Henry; Hounmanou, Yaovi Mahuton Gildas; Kisanga, Adela; Tuntufye, Huruma Nelwike

2018-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) in raw milk can be transmitted from animals to humans, and in Tanzania raw milk is sold in local markets and consumed as purchased. This study was performed to determine the molecular characteristics and antimicrobial susceptibility pattern of MRSA strains isolated from raw bovine milk sold at local markets in Tanzania. A total of 117 raw milk samples were cultured on Baird-Parker medium to isolate S. aureus and PCR was used for amplification of gltB gene for S. aureus identification and the presence of mecA gene for methicillin-resistant strains. Coagulase-negative (CN) S. aureus were reconfirmed using tube coagulase, DNase, and API Staph tests. MRSA isolates were spa typed whereas antimicrobial susceptibility testing was performed by the disc diffusion method. Forty-six coagulase positives (CP) and two CN S. aureus were identified. Most strains were resistant to penicillin (72%), and 3 isolates: 2 CN S. aureus and 1 coagulase-negative Staphylococci (CNS), were phenotypically resistant to vancomycin, oxacillin, and cefoxitin and were confirmed to carry mecA. Resistance to clindamycin, trimethoprim-sulfamethoxazole, and tetracycline was 23.9%, 30.4%, and 41.3%, respectively. Twelve isolates exhibited multidrug resistance; however, only one mecA positive strain among the three was typeable and belonged to spa type t2603. This study reports for the first time the presence of CN variant of MRSA, which was assigned the spa type t2603, and the presence of multidrug resistant S. aureus isolates from bovine milk in Morogoro, Tanzania.

Antimicrobial resistance and detection of the mecA gene besides enterotoxin-encoding genes among coagulase-negative Staphylococci isolated from clam meat of Anomalocardia brasiliana.

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Batista, Jacqueline Ellen Camelo; Ferreira, Ewerton Lucena; Nascimento, Danielle Cristina de Oliveira; Ventura, Roberta Ferreira; de Oliveira, Wagner Luis Mendes; Leal, Nilma Cintra; Lima-Filho, José Vitor

2013-12-01

The marine clam Anomalocardia brasiliana is a candidate as a sentinel animal to monitor the contamination levels of coliforms in shellfish-harvesting areas of Brazil's northeastern region. The aim of the present study was to search enterotoxin-encoding genes plus the mecA gene among coagulase-negative staphylococci (CNS) isolates from shellfish meats of A. brasiliana. The specimen clam (n=48; 40 clams per sample) was collected during low tide in the bay area of Mangue Seco from April through June 2009, and random samples of chilled and frozen shelled clam meat (n=33; 250 g per sample) were obtained from retail shops from January through March 2012. Seventy-nine CNS isolates were identified, including Staphylococcus xylosus, S. cohnii spp. urealyticus, S. sciuri, and S. lentus. A high percentage of isolates resistant to erythromycin (58.5%), penicillin (51.2%), and tetracycline (43.9%), and the fluoroquinolones levofloxacin (39%) and ciprofloxacin (34.1%) were recorded from those environmental samples. Isolates from retail shops were particularly resistant to oxacillin (55.3%) and penicillin (36.8%). All CNS resistant to oxacillin and/or cefoxitin were positive for the presence of the mecA gene, but phenotypically susceptible to vancomycin. Also, the enterotoxin-encoding genes seg and seh were detected through multiplex-polymerase chain reaction in 77.7% and 88.8% of the isolates from environmental samples, versus 90.5% and 100% of the isolates from retail shops, respectively. The data reveal the risk to public health due to consuming raw or undercooked shellfish containing enterotoxigenic plus methicillin-resistant CNS.

Detection of Macrolide, Lincosamide and Streptogramin Resistance among Methicillin Resistant Staphylococcus aureus (MRSA in Mumbai

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Arunagiri Subramanian

2015-01-01

Full Text Available Background: The increase in incidence of Methicillin Resistant Staphyloccocus aureus (MRSA and its extraordinary potential to develop antimicrobial resistance has highlighted the need for better agents to treat such infections. This has led to a renewed interest in use of new drugs for treatment with clindamycin and quinuprsitin-dalfopristin being the preferred choice for treatment. Aim & Objectives: This study was undertaken to detect the prevalence of MacrolideLincosamide-Streptogramin (MLS resistance among clinical isolates of MRSA.Material and Methods:Two hundred and thirty clinical isolates of S. aureus were subjected to routine antibiotic susceptibility testing including cefoxitin, erythromycin and quinupristindalfopristin. Inducible resistance to clindamycin was tested by 'D' test as per Clinical and Laboratory Standards Institute (CLSI guidelines. Results: Out of all S. aureus isolates, 93.91% were identified as MRSA. In the disc diffusion testing, 81.5% of isolates showed erythromycin resistance. Among these, the prevalence of constitutive (cMLS , inducible (iMLS b b and MS-phenotype were 35.80%, 31.82% and 32.39% respectively by the D-test method. 77.8% of isolates were resistant to quinupristin-dalfopristin and the Minimum Inhibitory Concentration (MIC ranged from 4–32 µg/ml. 89.20% of isolates were resistant to both quinupristin-dalfopristin and erythromycin of which 35.03%, 35.67% and 29.30% belonged to iMLS , cMLS and MS phenotype respectively. Conclusion: The emergence of quinupristindalfopristin resistance and MLS phenotypes brings b about the need for the simple and reliable D-test in routine diagnosis and further susceptibility testing for proper antimicrobial therapy.

Distribution and Antimicrobial Susceptibility of Foodborne Salmonella Serovars in Eight Provinces in China from 2007 to 2012 (Except 2009).

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Wang, Yin; Cao, Chenyang; Alali, Walid Q; Cui, Shenghui; Li, Fengqin; Zhu, Jianghui; Wang, Xin; Meng, Jianghong; Yang, Baowei

2017-07-01

One thousand four hundred ninety-one Salmonella isolates recovered from retail foods including chicken, beef, fish, pork, dumplings, and cold dishes in China in 2007, 2008, 2010, 2011, and 2012 were analyzed for distribution of serotype and antimicrobial susceptibility. A total of 129 Salmonella serotypes were detected among 1491 isolates. Salmonella Enteritidis (21.5%), Typhimurium (11.0%), Indiana (10.8%), Thompson (5.4%), Derby (5.1%), Agona (3.8%), and Shubra (3.0%) were the seven most important serotypes in 1491 isolates. For antibiotic susceptibility, except 16 (1.1%) isolates were susceptible to all tested antibiotics, 131 (8.8%) resisted 1-2 and 1344 (90.1%) resisted three or more antibiotics. One thousand forty-six (70.2%) of 1491 Salmonella isolates were identified as multidrug-resistant (MDR) isolates, which could resist three or more categories of antibiotics. Resistance to sulfisoxazole (78.1%) was most common among the tested Salmonella, followed by tetracycline (70.6%), trimethoprim/sulfamethoxazole (68.0%), and nalidixic acid (63.4%). Resistances to amikacin (20.0%), levofloxacin (18.7%), gatifloxacin (17.9%), ceftriaxone (17.7%), and cefoxitin (13.2%) were less frequently detected. Resistance to fluoroquinolones was most common among Salmonella Shubra and Indiana isolates, while resistance to cephalosporins was frequently detected among Salmonella Thompson isolates. The results highlighted the diversity of Salmonella serotypes and the high prevalence of Salmonella MDR isolates in China. Compared with Salmonella Enteritidis and Typhimurium isolates, the higher fluoroquinolones and cephalosporins resistance rates of some individual serotypes (Salmonella Shubra, Indiana, and Thompson) also provided more information for further study related to fluoroquinolones or cephalosporin-resistant Salmonella.

Community-acquired urinary tract infections in children: pathogens, antibiotic susceptibility and seasonal changes.

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Yolbaş, I; Tekin, R; Kelekci, S; Tekin, A; Okur, M H; Ece, A; Gunes, A; Sen, V

2013-04-01

Urinary tract infections (UTIs) are common infections affecting children. The aim of our study is to determine microorganisms that cause community-acquired urinary tract infections and their antibiotic susceptibility in children. Our investigation includes 150 cases which has positive urine culture. The cases are detected at Pediatric Polyclinics of Dicle University between June 2010 and June 2011. The study included 118 (78.7%) female and 32 (21.3%) male children. Urinary tract infections were seen in autumn 10.7% (n = 16), summer 35.3% (n = 53), winter 30.7% (n = 46) and spring 23.3% (n = 35). The culture results indicated 75.3% (n = 113) Escherichia coli; 20.7% (n = 31) Klebsiella; 2.7% (n = 4) Proteus and % 1.3 (n = 2) Pseudomonas. The antibiotic resistance against Escherichia coli was found out is amikacin (3%), ertapenem (7%), imipenem (0%), meropenem (0%), nitrofurantoin (9%), trimethoprim/sulfamethoxazole (58%), piperacillin (83%), amoxicillin/clavulanate (50%), ampicillin/sulbactam (65%), cefazolin (54%), cefotaxime (51%), cefuroxime sodium (51% ) and tetracycline (68%). The resistance ratios of Klebsiella are amikacin (0%), imipenem (0%), levofloxacin (0%), meropenem (0%), amoxicillin/clavulanate (57%), ampicillin/sulbactam (79%), ceftriaxone (68%), cefuroxime sodium (74%) and trimethoprim/sulfamethoxazole (61%). The results represent the increasing antibiotic resistance against microorganisms among the community-acquired UTI patients in a developing country such as Turkey. So, the physicians should consider resistance status of the infectious agent and choose effective antibiotics which are nitrofurantoin and cefoxitin for their empirical antibiotic treatment. Furthermore, they should be trained about selection of more effective antibiotics and check the regional studies regularly.

Perioperative antibiotics for surgical site infection in pancreaticoduodenectomy: does the SCIP-approved regimen provide adequate coverage?

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Donald, Graham W; Sunjaya, Dharma; Lu, Xuyang; Chen, Formosa; Clerkin, Barbara; Eibl, Guido; Li, Gang; Tomlinson, James S; Donahue, Timothy R; Reber, Howard A; Hines, Oscar J

2013-08-01

The Joint Commission Surgical Care Improvement Project (SCIP) includes performance measures aimed at reducing surgical site infections (SSI). One measure defines approved perioperative antibiotics for general operative procedures. However, there may be a subset of procedures not adequately covered with the use of approved antibiotics. We hypothesized that piperacillin-tazobactam is a more appropriate perioperative antibiotic for pancreaticoduodenectomy (PD). In collaboration with hospital epidemiology and the Division of Infectious Diseases, we retrospectively reviewed records of 34 patients undergoing PD between March and May 2008 who received SCIP-approved perioperative antibiotics and calculated the SSI rate. After changing our perioperative antibiotic to piperacillin-tazobactam, we prospectively reviewed PDs performed between June 2008 and March 2009 and compared the SSI rates before and after the change. For 34 patients from March through May 2008, the SSI rate for PD was 32.4 per 100 cases. Common organisms from wound cultures were Enterobacter and Enterococcus (50.0% and 41.7%, respectively), and these were cefoxitin resistant. From June 2008 through March 2009, 106 PDs were performed. During this period, the SSI rate was 6.6 per 100 surgeries, 80% lower than during March through May 2008 (relative risk, 0.204; 95% confidence interval [CI], 0.086-0.485; P = .0004). Use of piperacillin-tazobactam as a perioperative antibiotic in PD may reduce SSI compared with the use of SCIP-approved antibiotics. Continued evaluation of SCIP performance measures in relationship to patient outcomes is integral to sustained quality improvement. Copyright © 2013 Mosby, Inc. All rights reserved.

Biofilm production and beta-lactamic resistance in Brazilian Staphylococcus aureus isolates from bovine mastitis

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Viviane Figueira Marques

Full Text Available Abstract Staphylococcus spp. play an important role in the etiology of bovine mastitis. Staphylococcus aureus is considered the most relevant species due to the production of virulence factors such as slime, which is required for biofilm formation. This study aimed to evaluate biofilm production and its possible relation to beta-lactamic resistance in 20 S. aureus isolates from bovine mastitic milk. The isolates were characterized by pheno-genotypic and MALDI TOF-MS assays and tested for genes such as icaA, icaD, bap, agr RNAIII, agr I, agr II, agr III, and agr IV, which are related to slime production and its regulation. Biofilm production in microplates was evaluated considering the intervals determined along the bacterial growth curve. In addition, to determine the most suitable time interval for biofilm analysis, scanning electron microscopy was performed. Furthermore, genes such as mecA and blaZ that are related to beta-lactamic resistance and oxacillin susceptibility were tested. All the studied isolates were biofilm producers and mostly presented icaA and icaD. The Agr type II genes were significantly prevalent. According to the SEM, gradual changes in the bacterial arrangement were observed during biofilm formation along the growth curve phases, and the peak was reached at the stationary phase. In this study, the penicillin resistance was related to the production of beta-lactamase, and the high minimal bactericidal concentration for cefoxitin was possibly associated with biofilm protection. Therefore, further studies are warranted to better understand biofilm formation, possibly contributing to our knowledge about bacterial resistance in vivo.

First Report in China on the Identification and Drug Sensitivity of Mycobacterium elephantis Isolated from the Milk of a Cow with Mastitis.

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Ji, Ling Yun; Xu, Dong Lei; Yin, Shu Peng; Liu, Hai Can; Li, Gui Lian; Jiang, Yi; Wei, Jian Hao; Zeng, Hao; Lou, Yong Liang; Lyu, Jian Xin; Wan, Kang Lin

2017-07-01

In this study, milk from a cow with mastitis was analyzed to determine the presence of mycobacterial infection. Milk quality and security problems pertaining to the safe consumption of dairy products were also discussed in this study. Milk was preprocessed with 4% NaOH. Then, mycobacteria were isolated from the milk sample on L-J medium. The isolate was identified using multiple loci Polymerase Chain Reaction (PCR) and multi-locus sequence analysis with 16S rRNA, sodA, hsp65, and ITS genes. The drug sensitivity of the isolate to 27 antibiotics was tested through alamar blue assay. Smooth, moist, pale yellow colonies appeared on the L-J medium within a week after inoculation. Based on the results of multiple loci PCR analysis, the isolate was preliminarily identified as non-tuberculous mycobacteria. The 16S rRNA, SodA, hsp65, and ITS gene sequences of the isolate exhibited 99%, 99%, 99%, and 100% similarities, respectively, with those of the published reference strains of Mycobacterium elephantis (M. elephantis). The drug sensitivity results showed that the strain is resistant to isoniazid, p-aminosalicylic acid, and trimesulf but is sensitive to ofloxacin, rifampicin, amikacin, capreomycin, moxifloxacin, kanamycin, levofloxacin, cycloserine, ethambutol, streptomycin, tobramycin, rifabutin, ciprofloxacin, linezolid, cefoxitin, clarithromycin, and minocycline. To the best of our knowledge, this study is initially to report the isolation of M. elephantis from the milk of a cow with mastitis in China. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Occurrence and antimicrobial sensitivity in staphylococci isolated from goat, sheep and cow’s milk

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Marcela Vyletělová

2011-01-01

Full Text Available The aim of this study was to compare the sensitivity to selected antibiotics in staphylococci isolated from goat (n = 60, sheep (n = 60 and cow’s milk (n = 120. The individual milk samples were inoculated onto Blood agar cultivated at 36 °C/24 h.The isolated species of staphylococci were identified using biochemical tests, namely STAPHYtest and identification program TNW pro 6.5. We examined the sensitivity of strains to the spectrum of antibiotics, as follows: vancomycin (VA, amoxicillin/clavulanic acid (AMC, penicillin (P, rifampicin (RD, oxacillin (OX, tetracycline (TE, erythromycin (E, chloramphenicol (C, clindamycin (DA, gentamicin (CN, ciprofloxacin (CIP, teicoplanin (TEC, cefoxitin (FOX and novobiocin (NOV. Altogether, 97 staphylococcal isolates were obtained; 70 from cow’s milk, 11 from goat’s milk and 16 from sheep’ milk. Staphylococcus aureus was the most frequent species in milk of all animal origin tested, was detected in 54 (45% cow’s milk, 10 (17% goat’s and 15 (25% sheep’ milk samples. S. lentus was identified only in goat’s and sheep’ milk whereas in cow’s milk there were representation of staphylococcal species as follows: S. haemolyticus (n = 7, S. chromogenes (n = 2, S. warneri (n = 2, S. xylosus (n = 2, S. epidermidis (n = 2 and unclassified staphylococci (n = 1. The results of S. aureus sensitivity are similar for all tested antibiotics and for all monitored milk: No resistance to vancomycin, rifampicin, chloramphenicol and teicoplanin was recorded in obtained S. aureus isolates whereas the resistance to ciprofloxacin was found out most often.

An Investigation of the Prevalence of AmpC-producing Pseudomonas aeruginosa in Clinical Samples in Zahedan City, Iran

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Javad Adabi

2017-06-01

Full Text Available Background and Objectives: AmpC beta-lactamases are among cephalosporinases encoded on the chromosomes of many Enterobacteriaceae. In many bacteria, induction of AmpC enzymes can be made at a very high level by numerous mutations. In this study, the prevalence of chromosomal AmpC genes, was investigated in the isolates of Pseudomonas aeruginosa isolated from teaching hospitals in Zahedan city in 2015. Methods: In this descriptive cross-sectional study, 100 P. aeruginosa isolates were isolated from 391 clinical samples using biochemical and conventional methods. cefoxitin (30μg disk diffusion method was used to isolate AmpC-producing strains, and multiplex PCR was used to identify chromosomal AmpC genes. ESBL containing strains was assessed using ceftazidime (30μg and cefotaxime/clavulanic acid (30μg/10μg disk diffusion tests. Data analysis was performed using χ2 test. Results: In primary phenotypic screening, out of 100 P. aeruginosa isolated, 88 isolates were ESBL producers and 20 isolates (20% were AmpC beta-lactamase producers. Among 20 phenotypically identified AmpC producing isolates, 19 isolates (95% had FOX gene, 7 isolates (35% had EBC gene, 4 isolates (20% had ACC gene, and 15 isolates isolates (75% had DHA gene, which were detected by multiPlex PCR assay. Conclusion: The results of the present study indicated that the presence of AmpC leads to resistance of bacteria to many cephalosporins. Also, use of multiplex PCR yields the best results in the group identification of these genes.

Prevalence of methicillin-resistant Staphylococcus aureus skin and nasal carriage isolates from bovines and its antibiogram

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Alok Kumar

2017-06-01

Full Text Available Aim: This study was conducted to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA in cattle and buffalo and to study their antibiotic resistance pattern. Materials and Methods: A total of 136 samples (skin and nasal swab from cattle and buffalo were collected. MRSA was identified by conventional bacterial culture techniques which were further confirmed by amplification of S. aureus-specific 16S rRNA by polymerase chain reaction (PCR. The isolates were further analyzed for the presence of mecA gene by PCR. The antimicrobial susceptibility profiling was performed by disc diffusion method. Results: The prevalence of MRSA in the current study was 28.57% and 34.28% in cattle nasal and skin swab, respectively, with an overall prevalence of 31.43% MRSA among cattle. Buffalo nasal and skin sample showed MRSA prevalence of 54.55% and 39.4%, respectively, with 46.9% overall prevalence. PCR could detect mecA gene in 36.4% and 58% MRSA isolates from cattle and buffalo, respectively. Antimicrobial susceptibility test found MRSA resistant to penicillin and oxytetracycline (88% each, cefoxitin (75%, cotrimoxazole (62%, and amoxyclav (50%. 100% sensitivity was observed against ciprofloxacin, amikacin, chloramphenicol, and gentamicin. Three (16.7% MRSA isolates from buffalo were found resistant to vancomycin. Conclusion: Cattle and buffalo were identified as a potential carrier of MRSA in Bihar (India. The isolation of vancomycinresistant S. aureus (VRSA in the current study indicates the emergence of VRSA in animal population which may be transmitted to the human beings working in close contact to the animals.

Antimicrobial susceptibility profile and research of mec A and erm genes in coagulase-negative staphylococci isolated from platelet concentrates bags

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Rosiéli Martini

2017-04-01

Full Text Available Abstract In recent years, several studies have described the clinical impact of bacterial infection associated with transfusion of platelet concentrates (PCs. Among the blood components, PCs are responsible for the highest rates of bacterial contamination as well as septic transfusion reactions. We assessed antimicrobial susceptibility profile, resistance to methicillin (MRCoNS, and resistance to macrolides, lincosamides and streptogramins of group B (MLSB of 16 coagulase-negative staphylococci (CoNS isolates from an investigation in 691 PCs bags. We then compared conventional and automated phenotypic methods, disc diffusion test (DD and VITEK(r 2, respectively as well as phenotypic and genotypic methods (Polymerase Chain Reaction - PCR. All CoNS were susceptible to vancomycin. The disc diffusion test characterized 18.75% as MRCoNS and 37.5% with inducible resistance to MLSB (iMLSB, and with VITEK(r 2, 6.3% and 31.25%, respectively. The mecA gene was detected in 18.75% and the erm gene in 31.25% of the isolates. In this study, we found equal percentage values between presence of the mecA gene by PCR and resistance to methicillin using cefoxitin by DD test, evidence of the erm gene by PCR, and iMLSB resistance by automation (VITEK(r 2. Moreover, we identified three strains with beta-lactamase overproduction, and the occurrence of a bigger mistake was verified when automation was compared with DD test. And we observed that D-test was the most reliable for the detection of iMLSB resistance in Staphylococcus sp.

Characterisation of drug resistance of nosocomial ESBL-producing E. coli isolates obtained from a Turkish university hospital between 2009 and 2012 by pulsed field gel electrophoresis and antibiotic resistance tests.

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Karagöz, Alper; Sunnetcioglu, Mahmut; Ceylan, Mehmet Resat; Bayram, Yasemin; Yalcin, Gozde; Kocak, Nadir; Suvak, Burak; Andac, Cenk A

2016-01-01

In this study, drug resistance of 28 ESBL-producing Escherichia coli isolates obtained from 144 patients hospitalized at the Yüzüncüyil University Hospital at Van (YUH), Turkey, between 2009 and 2012 were characterized by pulsed field gel electrophoresis and antibiotic susceptibility tests. Antibiotic resistance profile was determined by Phoenix automated system (BD, USA). The ratio of ESBL-producing E. coli strains was determined to be 19.4% (28 out of 144 E. coli isolates). It was determined that the anaesthesiology, paediatrics and thoracic medicine intensive care units in YUH were cross-contaminated between 2009 and 2012 by ESBL-producing E. coli strains, which is a sign of nosocomial infection in YUH. Analysis of PFGE results gave rise to two main PFGE profiles, profile-A with four subprofiles and profile-B with three subprofiles, where profile-A predominates over profile-B (14%). Comparison of the antibiotic resistance profile with the PFGE profile yielded similarities while some differences also exist due to either identical restriction enzyme cutting sites with slightly different genetic sequences in between the cutting sites or newly formed restriction enzyme cutting sites that do not affect antibiotic resistance genes. Enterobacteriaceae, particularly E. coli, have developed resistance in YUH by producing ESBLs against oxyimino and non-oxyimino cephalosporins, and penicillin-type antibiotics. Therefore, more effective antibiotics such as cefoxitin or cefoperazone-sulbactam should be used for the treatment of future nosocomial infections in YUH while hospital staff should take care with hygiene, such as hand washing.

Phenotypic and molecular characterization of antimicrobial resistance in Proteus mirabilis isolates from dogs.

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

2014-11-01

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.

Anaerobic bacteria colonizing the lower airways in lung cancer patients.

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Rybojad, Pawel; Los, Renata; Sawicki, Marek; Tabarkiewicz, Jacek; Malm, Anna

2011-01-01

Anaerobes comprise most of the endogenous oropharyngeal microflora, and can cause infections of airways in lung cancer patients who are at high risk for respiratory tract infections. The aim of this study was to determine the frequency and species diversity of anaerobes in specimens from the lower airways of lung cancer patients. Sensitivity of the isolates to conventional antimicrobial agents used in anaerobe therapy was assessed. Respiratory secretions obtained by bronchoscopy from 30 lung cancer patients were cultured onto Wilkins-Chalgren agar in anaerobic conditions at 37°C for 72-96 hours. The isolates were identified using microtest Api 20A. The minimal inhibitory concentrations for penicillin G, amoxicillin/clavulanate, piperacillin/tazobactam, cefoxitin, imipenem, clindamycin, and metronidazole were determined by E-test. A total of 47 isolates of anaerobic bacteria were detected in 22 (73.3%) specimens. More than one species of anaerobe was found in 16 (53.3%) samples. The most frequently isolated were Actinomyces spp. and Peptostreptococcus spp., followed by Eubacterium lentum, Veillonella parvula, Prevotella spp., Bacteroides spp., Lactobacillus jensenii. Among antibiotics used in the study amoxicillin/clavulanate and imipenem were the most active in vitro (0% and 2% resistant strains, respectively). The highest resistance rate was found for penicillin G and metronidazole (36% and 38% resistant strains, respectively). The results obtained confirm the need to conduct analyses of anaerobic microflora colonizing the lower respiratory tract in patients with lung cancer to monitor potential etiologic factors of airways infections, as well as to propose efficient, empirical therapy.

Antibiotic resistance and biofilm formation among coagulase-negative staphylococci isolated from clinical samples at a tertiary care hospital of eastern Nepal

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Lok Bahadur Shrestha

2017-08-01

Full Text Available Abstract Background Coagulase negative staphylococci were long regarded non-pathogenic as they are the commensals of human skin and mucosa but the recent changes in the medical practice and changes in underlying host populations, they are being considered significant pathogens associated with number of nosocomial infections. The objective of the study was to determine the species, antimicrobial susceptibility pattern, biofilm forming ability of the clinically significant CoNS isolates and to compare the different methods for the detection of biofilm formation. Methods A total of 52 clinically significant CoNS isolates obtained from different units during a year period were studied. Characterization was done using standard microbiological guidelines and antimicrobial susceptibility was done following CLSI guidelines. Biofilm formation was detected by using three methods i.e. tissue culture plate method, congo red agar method and tube adherence method. Results Among 52 isolates, S. epidermidis (52% was the most common species which was followed by S. saprophyticus (18% and S. haemolyticus (14%. Antimicrobial susceptibility pattern of CoNS documented resistance of 80% to ampicillin. Resistance to cefoxitin and ceftriaxone was observed in 58% of the isolates. Biofilm formation was observed in 65.38% of the isolates. The accuracy of Congo red agar and tube adherence method for the detection of biofilm formation was 82% and 76% respectively. Conclusion CoNS isolates obtained from clinical samples should be processed routinely and antimicrobial susceptibility testing should be performed. Multidrug-resistant CoNS are prevalent. All the three methods i.e. tissue culture plate, Congo red agar and tube adherence method can be used in detecting biofilm formation.

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

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

2017-04-01

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 M abscessus produces the broad-spectrum β-lactamase Bla Mab We determine whether inhibition of Bla Mab 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 Bla Mab 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 (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 Bla Mab by avibactam improved the survival of zebrafish embryos treated with imipenem. Expression of the gene encoding Bla Mab was induced (20-fold) in the infected macrophages. Inhibition of Bla Mab by avibactam improved the efficacy of imipenem against M. abscessus in 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 Bla Mab , since the production of the β-lactamase is inducible in macrophages. Copyright © 2017 American Society for Microbiology.

In vitro activity of ivermectin against Staphylococcus aureus clinical isolates

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Shoaib Ashraf

2018-02-01

Full Text Available Abstract Background Ivermectin is an endectocide against many parasites. Though being a macrocyclic lactone, its activity against bacteria has been less known, possibly due to the fact that micromolar concentrations at tissue levels are required to achieve a therapeutic effect. Among pathogenic bacteria of major medical significance, Staphylococcus aureus cause a number of diseases in a wide variety of hosts including humans and animals. It has been attributed as one of the most pathogenic organisms. The emergence of methicillin resistance has made the treatment of S. aureus even more difficult as it is now resistant to most of the available antibiotics. Thus, search for alternate anti-staphylococcal agents requires immediate attention. Methods Twenty-one clinical isolates of S. aureus were isolated from bovine milk collected from Lahore and Faisalabad Pakistan. Different anthelmintics including levamisole, albendazole and ivermectin were tested against S. aureus to determine their minimum inhibitory concentrations. This was followed-up by growth curve analysis, spot assay and time-kill kinetics. Results The results showed that ivermectin but not levamisole or albendazole exhibited a potent anti-staphylococcal activity at the concentrations of 6.25 and 12.5 μg/ml against two isolates. Interestingly, one of the isolate was sensitive while the other was resistant to methicillin/cefoxitin. Conclusions Our novel findings indicate that ivermectin has an anti-bacterial effect against certain S. aureus isolates. However, to comprehend why ivermectin did not inhibit the growth of all Staphylococci needs further investigation. Nevertheless, we have extended the broad range of known pharmacological effects of ivermectin. As pharmacology and toxicology of ivermectin are well known, its further development as an anti-staphylococcal agent is potentially appealing.

Multiplex PCR Study of Plasmid-Mediated AmpC Beta-Lactamases Genes in Clinical Isolates of Escherichia coli

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Maryam Dehghani

2017-02-01

Full Text Available Background:   AmpC β-lactamases are important cephalosporinases chromosomally encoded in many of Enterobacteriaceae and a few other organisms where they mediate resistance to cephalothin, cefazolin, cefoxitin and penicillins. The six different families of plasmid-mediated AmpC β-lactamases have been described, but no phenotypic test can discriminate among them. AmpC multiplex PCR has been successfully used to discriminate plasmid-mediated ampC specific families in organisms such as Klebsiella pneumonia and Escherichia coli. The aim of this study was to indicate the prevalence of AmpC β-lactamase genes by specifically designed primers through PCR test.Methods:   243 total clinical urine samples were collected, and 227 isolates were identified as Escherichia coli based on standard biochemical tests. Subsequently, the isolates were screened by disc diffusion and combined disc test for β-lactamase production. Resistant isolates were evaluated by PCR for ampC family determination. Results:  Antibiotic resistance pattern were observed as follows: cefepime (%25, ceftazidime (%31, ceftriaxone (%37, cefotaxime (%38. The ratio of isolates was detected as ESBLs and AmpC producers were 34% and 5.2%, respectively. PCR performed on 12 selected isolates via phenotypic tests and the results revealed that among 12 isolates, 11 contained blaCMY-42. Conclusion:  Unfortunately, antibiotic resistance has become an increasingly critical problem in many countries like Iran and occurrence of isolates co-expressing AmpC-β-lactamases and ESBLs can create serious problems in the future. As antibiotic options in the treatment of AmpC β-lactamases and ESBLs producing organisms are extremely limited, molecular screening by laboratories is suggested to reduce the risk of therapeutic defeat.

Staphylococcus species and their Methicillin-Resistance in 7424 Blood Cultures for Suspected Bloodstream Infections

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Ariana ALMAŞ

2011-06-01

Full Text Available Objectives: The aim of this study was to evaluate the distribution of Staphylococcus species in bloodstream infections and to assess their susceptibility to methicillin. Material and Methods: Between January 1st 2008 - December 31st 2010, 7424 blood culture sets were submitted to the Laboratory Department of the Hospital for Clinical Infectious Diseases in Cluj-Napoca, Romania. The blood cultures were performed using BacT/Alert until January 2010 and BacT/Alert 3D automated system (bioMérieux after that date. The blood culture bottles were incubated at 37°C in a continuously monitoring system for up to 7 days. The strain identifications were performed by conventional methods, ApiStaph galleries and Vitek 2 Compact system. Susceptibility to methicillin was determined by disk diffusion method with cefoxitin disk and by using Vitek 2 Compact system. Results: From the total number of performed blood cultures, 568 were positive with Staphylococcus species. From 168 bacteriemic episodes 103 were with Staphylococcus aureus. Among 65 coagulase-negative staphylococci isolates, Staphylococcus epidermidis was the most frequently isolated species (34, followed by Staphylococcus hominis (15, Staphylococcus haemolyticus (8, Staphylococcus saprophyticus (3, Staphylococcus cohnii (1, Staphylococcus auricularis (1, and 3 strains that were not identified at species level. Methicillin resistance was encountered in 53.40% of Staphylococcus aureus strains and in 80% of coagulase-negative staphylococci. Conclusions: An important percentage of blood cultures were contaminated with Staphylococcus species. The main species identified in true bacteriemia cases were Staphylococcus aureus and Staphylococcus epidermidis. The percentage of methicillin-resistance, proved to be high not only for coagulase-negative staphylococci but also for Staphylococcus aureus.

Molecular and phenotypic characteristics of methicillin-resistant Staphylococcus aureus isolated from hospitalized patients.

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de Oliveira, Caio Ferreira; Morey, Alexandre Tadachi; Santos, Jussevania Pereira; Gomes, Ludmila Vilela Pereira; Cardoso, Juscélio Donizete; Pinge-Filho, Phileno; Perugini, Márcia Regina Eches; Yamauchi, Lucy Megumi; Yamada-Ogatta, Sueli Fumie

2015-07-30

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of infections acquired in both community and hospital settings. In this study, MRSA isolated from different sources of hospitalized patients was characterized by molecular and phenotypic methods. A total of 123 S. aureus isolates were characterized according to their genetic relatedness by repetitive element sequence based-PCR (REP-PCR), in vitro antimicrobial susceptibility profile, SCCmec typing and presence of seven virulence factor-encoding genes. REP-PCR fingerprinting showed low relatedness between the isolates, and the predominance of one specific lineage or clonal group was not observed. All isolates were susceptible to teicoplanin and linezolide. All isolates were resistant to cefoxitin and penicillin, and the majority were also resistant to one or more other antimicrobials. Fifty isolates (41.7%) were intermediately resistant to vancomycin. Most isolates harbored SCCmec type II (53.7%), followed by type I (22.8%), type IV (8.1%) and type III (1.6%). All isolates harbored at least two virulence factor-encoding genes, and the prevalence was as follows: coa, 100%; icaA, 100%; hla, 13.0%; hlb, 91.1%, hld, 91.1%; lukS-PV and lukF-PV, 2.4%; and tst, 34.1%. A positive association with the presence of hla and SCCmec type II, and tst and SCCmec type I was observed. This study showed the high virulence potential of multidrug-resistant MRSA circulating in a teaching hospital. A high prevalence of MRSA showing intermediate vancomycin resistance was also observed, indicating the urgent need to improve strategies for controlling the use of antimicrobials for appropriate management of S. aureus infections.

Detection of plasmid-mediated AmpC β-lactamase in Escherichia coli and Klebsiella pneumoniae

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N O Yilmaz

2013-01-01

Full Text Available Background: Detecting plasmid-mediated AmpC (pAmpC β-lactamase-producing organism is important for optimal infection control and providing accurate and effective treatment option for physicians. Objectives: The aim of this study was to investigate the prevalence of pAmpC β-lactamase and compare the results of boronic acid (BA disk test with other phenotypic tests detecting AmpC positive isolates. Materials and Methods: A total of 273 clinical isolates of Klebsiella pneumoniae (n: 82 and Escherichia coli (n: 191 were analysed. The presence of pAmpC β-lactamase was determined by BA disk test, cefoxitin (FOX screening test, modified three dimensional test (M3DT, and multiplex polymerase chain reaction (PCR. Pulsed-field gel electrophoresis was performed to evaluate the genetic similarities between isolates. To detect extended spectrum β-lactamases (ESBL in the presence of AmpC β-lactamase, ESBL confirmation test was carried out with and without BA solution. Results: Of the 273 strains tested, 127 strains were found FOX resistant, 114 were positive by M3DT, 108 were positive in BA disk test, and the multiplex PCR detected 24 pAmpC β-lactamase-positive isolate. The prevalence of AmpC-producing strains was 10.9% in E. coli and 3.6% in K. pneumoniae in the tested population by PCR. CIT and MOX group genes were predominant type in these strains. Conclusion: These results emphasize that clinical laboratories should consider testing the presence of pAmpC enzymes particularly in FOX-resistant isolates, and BA disk test will improve detection of this emerging resistance phenotype.

Epidemic of Postsurgical Infections Caused by Mycobacterium massiliense▿

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Duarte, Rafael Silva; Lourenço, Maria Cristina Silva; Fonseca, Leila de Souza; Leão, Sylvia Cardoso; Amorim, Efigenia de Lourdes T.; Rocha, Ingrid L. L.; Coelho, Fabrice Santana; Viana-Niero, Cristina; Gomes, Karen Machado; da Silva, Marlei Gomes; de Oliveira Lorena, Nádia Suely; Pitombo, Marcos Bettini; Ferreira, Rosa M. C.; de Oliveira Garcia, Márcio Henrique; de Oliveira, Gisele Pinto; Lupi, Otilia; Vilaça, Bruno Rios; Serradas, Lúcia Rodrigues; Chebabo, Alberto; Marques, Elizabeth Andrade; Teixeira, Lúcia Martins; Dalcolmo, Margareth; Senna, Simone Gonçalves; Sampaio, Jorge Luiz Mello

2009-01-01

An epidemic of infections after video-assisted surgery (1,051 possible cases) caused by rapidly growing mycobacteria (RGM) and involving 63 hospitals in the state of Rio de Janeiro, Brazil, occurred between August 2006 and July 2007. One hundred ninety-seven cases were confirmed by positive acid-fast staining and/or culture techniques. Thirty-eight hospitals had cases confirmed by mycobacterial culture, with a total of 148 available isolates recovered from 146 patients. Most (n = 144; 97.2%) isolates presented a PRA-hsp65 restriction pattern suggestive of Mycobacterium bolletii or Mycobacterium massiliense. Seventy-four of these isolates were further identified by hsp65 or rpoB partial sequencing, confirming the species identification as M. massiliense. Epidemic isolates showed susceptibility to amikacin (MIC at which 90% of the tested isolates are inhibited [MIC90], 8 μg/ml) and clarithromycin (MIC90, 0.25 μg/ml) but resistance to ciprofloxacin (MIC90, ≥32 μg/ml), cefoxitin (MIC90, 128 μg/ml), and doxycycline (MIC90, ≥64 μg/ml). Representative epidemic M. massiliense isolates that were randomly selected, including at least one isolate from each hospital where confirmed cases were detected, belonged to a single clone, as indicated by the analysis of pulsed-field gel electrophoresis (PFGE) patterns. They also had the same PFGE pattern as that previously observed in two outbreaks that occurred in other Brazilian cities; we designated this clone BRA100. All five BRA100 M. massiliense isolates tested presented consistent tolerance to 2% glutaraldehyde. This is the largest epidemic of postsurgical infections caused by RGM reported in the literature to date in Brazil. PMID:19403765

Emergence of multidrug-resistant Proteus mirabilis in a long-term care facility in Croatia.

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Bedenić, Branka; Firis, Nataša; Elveđi-Gašparović, Vesna; Krilanović, Marija; Matanović, Krešimir; Štimac, Iva; Luxner, Josefa; Vraneš, Jasmina; Meštrović, Tomislav; Zarfel, Gernot; Grisold, Andrea

2016-06-01

An increased frequency of Proteus mirabilis isolates resistant to expanded-spectrum cephalosporins was observed recently in a long-term care facility in Zagreb (Godan). The aim of this study was the molecular characterization of resistance mechanisms to new cephalosporins in P. mirabilis isolates from this nursing home. Thirty-eight isolates collected from 2013-2015 showing reduced susceptibility to ceftazidime were investigated. Antibiotic susceptibilities were determined by broth microdilution method. Inhibitor-based tests were performed to detect extended-spectrum (ESBLs) and AmpC β-lactamases. AmpC β-lactamases were characterized by polymerase chain reaction (PCR) followed by sequencing of bla ampC genes. Quinolone resistance determinants (qnr genes) were characterized by PCR. Genotyping of the isolates was performed by repetitive element sequence (rep)-PCR and pulsed-field gel electrophoresis (PFGE). Presence of an AmpC β-lactamase was confirmed in all isolates by combined-disk test with phenylboronic acid. All isolates were resistant to amoxicillin alone and combined with clavulanate, cefotaxime, ceftriaxone, cefoxitin, and ciprofloxacin; but susceptible to cefepime, imipenem, and meropenem. PCR followed by sequencing using primers targeting bla ampc genes revealed CMY-16 β-lactamase in all but one strain. Bla cmy-16 was carried by a non-conjugative plasmid which did not belong to any known plasmid-based replicon typing (PBRT) group. Rep-PCR identified one large clone consisting of 15 isolates, three pairs or related isolates, one triplet, and four singletons. PFGE confirmed the clonality of the isolates. This is the first report of multidrug resistant P. mirabilis in a nursing home in Croatia. Cephalosporin resistance was due to plasmid-mediated AmpC β-lactamase CMY-16.

Antimicrobial susceptibility of clinical isolates of anaerobic bacteria in Ontario, 2010-2011.

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Marchand-Austin, Alex; Rawte, Prasad; Toye, Baldwin; Jamieson, Frances B; Farrell, David J; Patel, Samir N

2014-08-01

The local epidemiology of antimicrobial susceptibility patterns in anaerobic bacteria is important in guiding the empiric treatment of infections. However, susceptibility data are very limited on anaerobic organisms, particularly among non-Bacteroides organisms. To determine susceptibility profiles of clinically-significant anaerobic bacteria in Ontario Canada, anaerobic isolates from sterile sites submitted to Public Health Ontario Laboratory (PHOL) for identification and susceptibility testing were included in this study. Using the E-test method, isolates were tested for various antimicrobials including, penicillin, cefoxitin, clindamycin, meropenem, piperacillin-tazobactam and metronidazole. The MIC results were interpreted based on guidelines published by Clinical and Laboratory Standards Institute. Of 2527 anaerobic isolates submitted to PHOL, 1412 were either from sterile sites or bronchial lavage, and underwent susceptibility testing. Among Bacteroides fragilis, 98.2%, 24.7%, 1.6%, and 1.2% were resistant to penicillin, clindamycin, piperacillin-tazobactam, and metronidazole, respectively. Clostridium perfringens was universally susceptible to penicillin, piperacillin-tazobactam, and meropenem, whereas 14.2% of other Clostridium spp. were resistant to penicillin. Among Gram-positive anaerobes, Actinomyces spp., Parvimonas micra and Propionibacterium spp. were universally susceptible to β-lactams. Eggerthella spp., Collinsella spp., and Eubacterium spp. showed variable resistance to penicillin. Among Gram-negative anaerobes, Fusobacterium spp., Prevotella spp., and Veillonella spp. showed high resistance to penicillin but were universally susceptible to meropenem and piperacillin-tazobactam. The detection of metronidazole resistant B. fragilis is concerning as occurrence of these isolates is extremely rare. These data highlight the importance of ongoing surveillance to provide clinically relevant information to clinicians for empiric management of

Isolation of methicillin-resistant Staphylococcus aureus from small ruminants and their meat at slaughter and retail level in Greece.

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Sergelidis, D; Papadopoulos, T; Komodromos, D; Sergelidou, E; Lazou, T; Papagianni, M; Zdragas, A; Papa, A

2015-11-01

Methicillin-resistant Staphylococcus aureus (MRSA) presents major health risk for humans causing serious nosocomial and community-acquired infections. Asymptomatic food-producing animal carriers and their meat may represent potential reservoirs for human infections. The aim of this study was to investigate the prevalence of MRSA in small ruminants raised under free-range conditions and their meat at slaughter and retail level in Northern Greece. Staphylococcus aureus was isolated from 9·6% of the examined samples. All isolates were resistant at least to one antibiotic, whereas 59·3% of them were multidrug resistant (MDR) exhibiting resistance to three or more antibiotic classes. The higher resistance rates were observed against penicillin (100%), tetracycline (74%), clindamycin (59·3%) and erythromycin (51·9%). Resistance to cefoxitin was exhibited by 22·2% of the isolates, but only one isolate was found to carry the mecA gene and belonged to spa type t127. This is the first time this type of Staph. aureus is isolated in Greece from the surface of a small ruminant's carcass. The presence of multidrug resistant Staph. aureus, and especially MRSA, in small ruminants and their meat, represents a potential threat for the spread of this pathogen in the community. This study is the first report on methicillin-resistant Staphylococcus aureus in small ruminants and their meat at slaughter level in Greece, elucidating a possible vehicle food for transmission to humans. These results suggest that human or animal sources could be involved in meat contamination and thus sources of contamination require investigation to control the dispersion of MRSA in the community. © 2015 The Society for Applied Microbiology.

Isolation and characterization of Faecalibacterium prausnitzii from calves and piglets.

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Carla Foditsch

Full Text Available The goal of our study was to isolate and characterize Faecalibacterium prausnitzii from fecal samples of healthy calves and piglets, in order to develop a novel probiotic for livestock animals. We identified 203 isolates of Faecalibacterium sp., which were clustered in 40 genetically distinct groups. One representative isolate from each cluster was selected for further characterization. The concentrations of the short chain fatty acids (SCFA acetate, butyrate, propionate and isobutyrate in the culture media were measured by gas chromatography. We observed reduction in the concentration of acetate followed by concomitant increase in the concentration of butyrate, suggesting that the isolates were consuming acetate present in the media and producing butyrate. Butyrate production correlated positively with bacterial growth. Since butyrate has many benefits to the colonic epithelial cells, the selection of strains that produce higher amounts of butyrate is extremely important for the development of this potential probiotic. The effect of pH and concentration of bile salts on bacterial growth was also evaluated in order to mimic the conditions encountered by F. prausnitzii in vivo. The optimal pH for growth ranged between 5.5 and 6.7, while most isolates were inhibited by of the lowest concentration of bile salts tested (0.1%. Antimicrobial resistance profile showed that most isolates of Faecalibacterium sp. were resistant against ciprofloxacin and sulfamethoxazole-trimethoprim. More than 50% of the isolates were resistant to tetracycline, amikacin, cefepime and cefoxitin. A total of 19 different combinations of multidrug resistance were observed among the isolates. Our results provide new insights into the cultural and physiological characteristics of Faecalibacterium prausnitzii illustrating large variability in short chain fatty acid production, in vitro growth, sensitivity to bile salts, and antibiotic resistance and suggesting that future

Choice of intravenous antibiotic prophylaxis for colorectal surgery does matter.

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Deierhoi, Rhiannon J; Dawes, Lillian G; Vick, Catherine; Itani, Kamal M F; Hawn, Mary T

2013-11-01

The Surgical Care Improvement Program endorses mandatory compliance with approved intravenous prophylactic antibiotics; however, oral antibiotics are optional. We hypothesized that surgical site infection (SSI) rates may vary depending on the choice of antibiotic prophylaxis. A retrospective cohort study of elective colorectal procedures using Veterans Affairs Surgical Quality Improvement Program (VASQIP) and SSI outcomes data was linked to the Office of Informatics and Analytics (OIA) and Pharmacy Benefits Management (PBM) antibiotic data from 2005 to 2009. Surgical site infection rates by type of IV antibiotic agent alone (IV) or in combination with oral antibiotic (IV + OA) were determined. Generalized estimating equations were used to examine the association between type of antibiotic prophylaxis and SSI for the entire cohort and stratified by use of oral antibiotics. After 5,750 elective colorectal procedures, 709 SSIs (12.3%) developed within 30 days. Oral antibiotic + IV (n = 2,426) had a lower SSI rate than IV alone (n = 3,324) (6.3% vs 16.7%, p antibiotic given (p ≤ 0.0001). Generalized estimating equations adjusting for significant covariates of age, body mass index, procedure work relative value units, and operation duration demonstrated an independent protective effect of oral antibiotics (odds ratio [OR] 0.37, 95% CI 0.29 to 0.46), as well as increased rates of SSI associated with ampicillin/sulbactam (OR 2.21, 95% CI 1.37 to 3.56) and second generation cephalosporins (cefoxitin, OR 2.50, 95% CI 1.83 to 3.42; cefotetan, OR 2.70, 95% CI 1.72 to 4.22) when compared with first generation cephalosporin/metronidazole. The choice of IV antibiotic was related to the SSI rate; however, oral antibiotics were associated with reduced SSI rate for every antibiotic class. Published by Elsevier Inc.

Prevalence of Methicillin-Resistant Staphylococcus aureus from Equine Nasopharyngeal and Guttural Pouch Wash Samples.

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Boyle, A G; Rankin, S C; Duffee, L A; Morris, D

2017-09-01

Methicillin-resistant Staphylococcus aureus (MRSA) is recognized as a cause of nosocomial infections in both human and veterinary medicine. Studies that examine the nasopharynx and guttural pouches of the horse as carriage sites for MRSA have not been reported. MRSA colonizes the nasopharynx and guttural pouch of horses. To determine the prevalence of MRSA in equine nasopharyngeal wash (NPW) and guttural pouch lavage (GPL) samples in a field population of horses. One hundred seventy-eight samples (123 NPW and 55 GPL) from 108 horses. Prospective study. Samples were collected from a convenience population of clinically ill horses with suspected Streptococcus equi subsp. equi (S. equi) infection, horses convalescing from a known S. equi infection, and asymptomatic horses undergoing S. equi screening. Samples were submitted for S. aureus aerobic bacterial culture with mannitol salt broth and two selective agars (cefoxitin CHROMagar as the PBP2a inducer and mannitol salt agar with oxacillin). Biochemical identification of Staphylococcus species and pulsed-field gel electrophoresis (PFGE), to determine clonal relationships between isolates, were performed. Methicillin-resistant Staphylococcus (MRS) was isolated from the nasopharynx of 7/108 (4%) horses. Three horses had MRSA (2.7%), and 4 had MR-Staphylococcus pseudintermedius (MRSP). MRSA was isolated from horses on the same farm. PFGE revealed the 3 MRSA as USA 500 strains. Sampling the nasopharynx and guttural pouch of community-based horses revealed a similarly low prevalence rate of MRSA as other studies sampling the nares of community-based horses. More study is required to determine the need for sampling multiple anatomic sites when screening horses for MRSA. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Evaluación del potencial probiótico de bacterias ácido lácticas para reducir el colesterol in vitro

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Clementina Cueto

2012-01-01

Full Text Available El co nsumo diario de alimentos probióticos reduce los niveles de colesterol sérico en un 3%, valor significativo para la prevención de la hipercolesterolemia, factor de riesgo de enfermedad cardiovascular y causal de mortalidad. Algunas especies del género Lact obacillus , utilizadas en la industria alimentaria como probiótico, reducen el colesterol sérico por dos mecanismos, la adsorción de colesterol y producción de la enzima hidrolasa de sales biliares. El objetivo del estudio fue evaluar el potencial probiótic o de un grupo de bacterias lácticas aisladas de suero costeño. Se aislaron 53 cepas a partir de nueve muestras de suero costeño; el potencial probiótico de las bacterias se evaluó por tolerancia a pH 2.0, 0.3% de sales biliares y sensibilidad a vancomicina y cefoxitin. Se seleccionaron cinco microorganismos y se identificaron molecularmente, como Lactobacillus fermentum . La capacidad de adsorber el colesterol medida por el método de Kimoto, presentó disminución de 53.06 ± 2.69 μg.mL - 1 para la cepa K73 y 7. 23 ± 2.69 μg.mL - 1 para la cepa K75. Esas mismas cepas mostraron la mayor actividad total y específica de la enzima. Los resultados evidenciaron que no existe relación entre la producción de la enzima y la adsorción del colesterol. La cepa con mayor potenci al probiótico fue K73. La propiedad hipocolesterolémica de Lactobacillus fermentum , podría ser el inicio de la búsqueda de matrices alimentarias que permitan disminuir los niveles del colesterol sérico y adicionen valor agregado al producto.

Antimicrobial resistance and phylogenetic groups in isolates of Escherichia coli from seagulls at the Berlengas nature reserve.

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Radhouani, H; Poeta, P; Igrejas, G; Gonçalves, A; Vinué, L; Torres, C

2009-08-01

Fifty-three faecal samples from yellow-legged gulls (Larus cachinnans) at the Berlengas nature reserve in Portugal were cultured on Levine agar plates not supplemented with antimicrobial agents, and one Escherichia coli colony was isolated and identified from each sample. The percentages of resistant isolates for each of the drugs were ampicillin (43.4 per cent), tetracycline (39.6 per cent), nalidixic acid (34.0 per cent), streptomycin (32.1 per cent), trimethoprim-sulfamethoxazole (SXT) (26.4 per cent), ciprofloxacin (18.9 per cent), chloramphenicol (18.9 per cent), gentamicin (7.5 per cent), tobramycin (7.5 per cent) amikacin (5.7 per cent) and amoxicillin-clavulanic acid (1.9 per cent). All the isolates were susceptible to cefoxitin, ceftazidime, cefotaxime, aztreonam and imipenem. The following resistance genes were detected: bla(TEM) (17 of 23 ampicillin-resistant isolates), tet(A) and/or tet(B) (18 of 21 tetracycline-resistant isolates), aadA (12 of 17 streptomycin-resistant isolates), cmlA (all chloramphenicol-resistant isolates), aac(3)-II with or without aac(3)-IV (all four gentamicin-resistant isolates), and sul1 and/or sul2 and/or sul3 (all 14 SXT-resistant isolates). The intI1 gene was detected in 10 of 14 SXT-resistant isolates, and three of them also contained class 2 integrons; four different gene cassette arrangements were identified among class 1 integrons (aadA, dfrA1+aadA1, dfrA12+orfF+aadA2 and sat+psp+aadA2) and one among the class 2 integrons (dfrA1+sat+aadA1). Ninety per cent of the isolates were included in the A or B1 phylogenetic groups.

Bacterial Species and Antibiotic Sensitivity in Korean Patients Diagnosed with Acute Otitis Media and Otitis Media with Effusion.

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Kim, Sang Hoon; Jeon, Eun Ju; Hong, Seok Min; Bae, Chang Hoon; Lee, Ho Yun; Park, Moo Kyun; Byun, Jae Yong; Kim, Myung Gu; Yeo, Seung Geun

2017-04-01

Changes over time in pathogens and their antibiotic sensitivity resulting from the recent overuse and misuse of antibiotics in otitis media (OM) have complicated treatment. This study evaluated changes over 5 years in principal pathogens and their antibiotic sensitivity in patients in Korea diagnosed with acute OM (AOM) and OM with effusion (OME). The study population consisted of 683 patients who visited the outpatient department of otorhinolaryngology in 7 tertiary hospitals in Korea between January 2010 and May 2015 and were diagnosed with acute AOM or OME. Aural discharge or middle ear fluid were collected from patients in the operating room or outpatient department and subjected to tests of bacterial identification and antibiotic sensitivity. The overall bacteria detection rate of AOM was 62.3% and OME was 40.9%. The most frequently isolated Gram-positive bacterial species was coagulase negative Staphylococcus aureus (CNS) followed by methicillin-susceptible S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), and Streptococcus pneumonia (SP), whereas the most frequently isolated Gram-negative bacterium was Pseudomonas aeruginosa (PA). Regardless of OM subtype, ≥ 80% of CNS and MRSA strains were resistant to penicillin (PC) and tetracycline (TC); isolated MRSA strains showed low sensitivity to other antibiotics, with 100% resistant to PC, TC, cefoxitin (CFT), and erythromycin (EM); and isolated PA showed low sensitivity to quinolone antibiotics, including ciprofloxacin (CIP) and levofloxacin (LFX), and to aminoglycosides. Bacterial species and antibiotic sensitivity did not change significantly over 5 years. The rate of detection of MRSA was higher in OME than in previous studies. As bacterial predominance and antibiotic sensitivity could change over time, continuous and periodic surveillance is necessary in guiding appropriate antibacterial therapy. © 2017 The Korean Academy of Medical Sciences.

The Role of OmpK35, OmpK36 Porins, and Production of β-Lactamases on Imipenem Susceptibility in Klebsiella pneumoniae Clinical Isolates, Cairo, Egypt.

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Wassef, Mona; Abdelhaleim, Mona; AbdulRahman, Eiman; Ghaith, Doaa

2015-12-01

OmpK35 and OmpK36 are the major outer membrane porins of Klebsiella pneumoniae. We aimed to study the effect of combined porin loss and production of extended-spectrum β-lactamases (ESBLs) on imipenem susceptibility among K. pneumoniae clinical isolates. This study included 91 suspected ESBL-producing K. pneumoniae clinical isolates, isolated from different patient specimens at the Cairo University hospital from January to June 2010. All isolates were subjected to genotypic analysis of the outer membrane protein gene expression using reverse transcription-PCR (RT-PCR) and analysis of OmpK35/36 of 38 isolates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). By RT-PCR, loss of Omp35 was detected in 78 (85.7%) isolates, loss of Omp36 was detected in 64 (70.32%), and loss of both porins was detected in 62 (68.1%). Out of 91 isolates, 45 (49.5%) were resistant to cefoxitin, and 17 (18.7%) were confirmed as derepressed AmpC producers. Omp35 was lost in all FOX-resistant isolates, whereas Omp36 was lost in 42 (93.3%) (p-value 0.002). The mean of ceftazidime inhibition zone diameter was significantly decreased among ESBL-producing isolates with loss of Omp35/36 (p-value 0.041 and 0.006), respectively. The mean of imipenem minimal inhibitory concentration (MIC) was markedly increased to 8.55 μg/ml among AmpC-producing isolates with Omp35/36 loss, while the mean of imipenem MIC among the 66 confirmed ESBL producers was 0.32 μg/ml. Imipenem MIC was markedly increased among K. pneumoniae isolates showing AmpC production with loss of both porins OmpK35/36. Meanwhile, the association of porin OmpK35/36 loss with ESBL production was not a direct cause of resistance to imipenem.

Factors associated with the occurrence of MRSA CC398 in herds of fattening pigs in Germany

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Alt Katja

2011-11-01

Full Text Available Abstract Background The purpose of this study was to investigate the prevalence of MRSA in herds of fattening pigs in different regions of Germany, and to determine factors associated with the occurrence of this pathogen. For this purpose pooled dust samples were collected, and a questionnaire covered information regarding herd characteristics and management practices. Samples were pre-enriched in high-salt medium followed by selective enrichment containing cefoxitin/aztreonam, and culturing. Presumptive colonies were confirmed by multiplex-PCR targeting nuc-, mecA- and 16S rRNA-genes. Isolates were spa- and SCCmec-, and in selected cases, multilocus sequence-typed. Susceptibilities to 13 antimicrobials were determined by broth microdilution. Statistical analysis was carried out using backward stepwise logistic regression to calculate odds ratios with the MRSA test result as the outcome and herd characteristics as categorical covariates. Results Overall, 152 of 290 (52% fattening pig farms tested positive for MRSA. The prevalence in the east, north- and south-west of Germany ranged from 39 to 59%. t011 (66% and t034 (23% were the most commonly identified spa-types, and 85% of isolates carried SCCmec Type V. Identified spa-types were all associated with clonal complex CC398. Susceptibility testing revealed that all isolates were resistant to tetracycline. High resistance rates were also found for sulfamethoxazole/trimethoprim (40%, and quinupristin/dalfopristin (32%. In addition, 83% of strains displayed multidrug resistant (> 3 substance classes phenotypes. Logistic regression revealed herd size (large farms OR: 5.4; CI: 2.7-11.2; p Conclusions MRSA CC398 is widely distributed among herds of fattening pigs in Germany. Farm management plays a crucial role in the dissemination of MRSA with herd size, and production type representing potential major indicators.

Characterization of pig-associated methicillin-resistant Staphylococcus aureus.

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Li, Jun; Jiang, Nansong; Ke, Yuebin; Feßler, Andrea T; Wang, Yang; Schwarz, Stefan; Wu, Congming

2017-03-01

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) have been reported in various countries worldwide. However, although China is one of the biggest pig and pork producers, large-scale studies on pig-associated LA-MRSA from China are scarce. The aims of this study were to analyze 2420 non-duplicate samples collected from pigs at swine farms and slaughterhouses in different regions in China during 2014 for the prevalence of pig-associated MRSA and to determine the antimicrobial resistance pheno- and genotypes of the respective isolates. MRSA isolates were identified in 270 (11.2%) samples. The isolates were characterized by antimicrobial susceptibility testing, multilocus sequence typing (MLST), spa typing, pulsed-field gel electrophoresis (PFGE) and screening for resistance genes. All MRSA isolates belonged to the clonal complex 9 and spa type t899, but showed variable PFGE patterns. All isolates were non-susceptible to oxacillin, cefoxitin, clindamycin, chloramphenicol, florfenicol, ciprofloxacin, and valnemulin. High rates of resistance were also observed for tetracycline (99.6%), erythromycin (97.0%), quinupristin-dalfopristin (97.0%), and gentamicin (80.4%). Three linezolid-non-susceptible isolates containing the multi-resistance gene cfr and nine rifampicin-non-susceptible isolates with mutations in rpoB were detected. Resistance to β-lactams was exclusively associated with mecA, while phenicol resistance was mainly attributable to fexA, except in the three cfr-positive isolates. The pleuromutilin-lincosamide-streptogramin A resistance gene lsa(E) was identified in all MRSA isolates, and no other pleuromutilin resistance genes, except cfr in three isolates, were detected. Pigs are the most important hosts of LA-MRSA in China. Screening for pig-associated MRSA is necessary to monitor changes in epidemiology and characteristics of these important pathogens. Copyright © 2017 Elsevier B.V. All rights reserved.

Factors associated with the occurrence of MRSA CC398 in herds of fattening pigs in Germany.

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Alt, Katja; Fetsch, Alexandra; Schroeter, Andreas; Guerra, Beatriz; Hammerl, Jens A; Hertwig, Stefan; Senkov, Natalja; Geinets, Anna; Mueller-Graf, Christine; Braeunig, Juliane; Kaesbohrer, Annemarie; Appel, Bernd; Hensel, Andreas; Tenhagen, Bernd-Alois

2011-11-10

The purpose of this study was to investigate the prevalence of MRSA in herds of fattening pigs in different regions of Germany, and to determine factors associated with the occurrence of this pathogen. For this purpose pooled dust samples were collected, and a questionnaire covered information regarding herd characteristics and management practices. Samples were pre-enriched in high-salt medium followed by selective enrichment containing cefoxitin/aztreonam, and culturing. Presumptive colonies were confirmed by multiplex-PCR targeting nuc-, mecA- and 16S rRNA-genes. Isolates were spa- and SCCmec-, and in selected cases, multilocus sequence-typed. Susceptibilities to 13 antimicrobials were determined by broth microdilution. Statistical analysis was carried out using backward stepwise logistic regression to calculate odds ratios with the MRSA test result as the outcome and herd characteristics as categorical covariates. Overall, 152 of 290 (52%) fattening pig farms tested positive for MRSA. The prevalence in the east, north- and south-west of Germany ranged from 39 to 59%.t011 (66%) and t034 (23%) were the most commonly identified spa-types, and 85% of isolates carried SCCmec Type V. Identified spa-types were all associated with clonal complex CC398. Susceptibility testing revealed that all isolates were resistant to tetracycline. High resistance rates were also found for sulfamethoxazole/trimethoprim (40%), and quinupristin/dalfopristin (32%). In addition, 83% of strains displayed multidrug resistant (> 3 substance classes) phenotypes.Logistic regression revealed herd size (large farms OR: 5.4; CI: 2.7-11.2; p pig operations. MRSA CC398 is widely distributed among herds of fattening pigs in Germany. Farm management plays a crucial role in the dissemination of MRSA with herd size, and production type representing potential major indicators.

Bacteriuria amongst pregnant women in the Buea Health District, Cameroon: prevalence, predictors, antibiotic susceptibility patterns and diagnosis.

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Mokube, Morike Ngoe; Atashili, Julius; Halle-Ekane, Gregory Edie; Ikomey, George M; Ndumbe, Peter M

2013-01-01

Bacteriuria is associated with significant maternal and foetal risks. However, its prevalence is not known in our community. This study was carried out to determine the prevalence and predictors of bacteriuria in pregnant women of the Buea Health District (BHD) as well as the antibiotic sensitivity patterns of bacterial isolates. It also sought to determine the diagnostic performance of the nitrite and leucocyte esterase tests in detecting bacteriuria in these women. An observational analytic cross-sectional study was carried out amongst pregnant women attending selected antenatal care centres in Buea. We recruited 102 consenting pregnant women for the study. Demographic and clinical data were collected using structured questionnaires. Clean catch midstream urine was collected from each participant in sterile leak proof containers. Samples were examined biochemically, microscopically and by culture. Significant bacteriuria was defined as the presence of ≥10⁸ bacteria/L of cultured urine. Identification and susceptibility of isolates was performed using API 20E and ATB UR EU (08) (BioMerieux, Marcy l'Etoile, France). Significant bacteriuria was found in the urine of 24 of the 102 women tested giving a bacteriuria prevalence of 23.5% in pregnant women of the BHD. Asymptomatic bacteriuria was detected in 8(7.8%) of the women. There was no statistically significant predictor of bacteriuria. Escherichia coli were the most isolated (33%) uropathogens and were 100% sensitive to cefixime, cefoxitin and cephalothin. The nitrite and leucocyte esterase tests for determining bacteriuria had sensitivities of 8%, 20.8% and specificities of 98.7% and 80.8% respectively. Bacteriuria is frequent in pregnant women in the BHD suggesting the need for routine screening by urine culture. Empiric treatment with cefixime should be instituted until results of urine culture and sensitivity are available. Nitrite and leucocyte esterase tests were not sensitive enough to replace urine

PREDISPOSING FACTORS AND AETIOLOGY OF URINARY TRACT INFECTIONS IN PREGNANT WOMEN

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Prem Prakash

2016-06-01

Full Text Available BACKGROUND Urinary tract infection (UTI is a common infection in pregnant women. It is responsible for range of complications causing perinatal and maternal morbidity and mortality. AIM To assess the associated risk factors, aetiology and their antibiogram of UTI among pregnant women. METHODOLOGY This is a cross-sectional study carried out in Department of Microbiology & Department of Obstetrics from March 2015 to February 2016. The patient details and risk factors were recorded. Midstream & catheter urine specimens from pregnant women with symptoms of UTI were collected and sent for routine microscopy, culture and sensitivity. RESULTS In 550 pregnant women, 122(22.18% had significant bacteriuria and 72(17.72% had low colony count UTI. The most affected number age group was 25-35 years (58.85% followed by 15-25 years. Of the associated risk factors, multiparity 45.31%, low socioeconomic status 42.18%, anaemia 39.06% etc. were important. Escherichia coli was most frequently isolated with a percentage of 29.14%, followed by Klebsiella species (17.49%, S. aureus (14.34% etc. Other isolated micro-organisms included Enterococci, Proteus mirabilis, Citrobacter, Pseudomonas, Acinetobacter species. The antibiotics with more than 50% sensitivity against Gram-negative isolates were Imipenem (74.7%, Levofloxacin (73.17%, Ciprofloxacin (69.10%, Amikacin (57.72%, Amoxiclav (55.28%, and Cefoperazone/Sulbactam (50.40%. The antibiotics for Gram-positive isolates were Linezolid (88.46%, Cefoxitin (78.84%, Teicoplanin (69.23% and Vancomycin (65.22%. CONCLUSION We found associated risk factors such as multiparity, low socioeconomic status, etc. E. coli was the most common bacteria isolated in our setting. Therefore, pregnant women should be assessed for associated risk factors and evaluated for the pathogenic organism during their regular follow-up. The drug sensitivity should be taken into consideration with their side effects related to pregnancy.

Efflux pump, the masked side of beta-lactam resistance in Klebsiella pneumoniae clinical isolates.

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Jean-Marie Pages

Full Text Available BACKGROUND: Beta-lactamase production and porin decrease are the well-recognized mechanisms of acquired beta-lactam resistance in Klebsiella pneumoniae isolates. However, such mechanisms proved to be absent in K. pneumoniae isolates that are non susceptible to cefoxitin (FOX and susceptible to amoxicillin+clavulanic acid in our hospital. Assessing the role of efflux pumps in this beta-lactam phenotype was the aim of this study. METHODOLOGY/FINDINGS: MICs of 9 beta-lactams, including cloxacillin (CLX, and other antibiotic families were tested alone and with an efflux pump inhibitor (EPI, then with both CLX (subinhibitory concentrations and EPI against 11 unique bacteremia K. pneumoniae isolates displaying the unusual phenotype, and 2 ATCC strains. CLX and EPI-dose dependent effects were studied on 4 representatives strains. CLX MICs significantly decreased when tested with EPI. A similar phenomenon was observed with piperacillin+tazobactam whereas MICs of the other beta-lactams significantly decreased only in the presence of both EPI and CLX. Thus, FOX MICs decreased 128 fold in the K. pneumoniae isolates but also 16 fold in ATCC strain. Restoration of FOX activity was CLX dose-dependent suggesting a competitive relationship between CLX and the other beta-lactams with regard to their efflux. For chloramphenicol, erythromycin and nalidixic acid whose resistance was also due to efflux, adding CLX to EPI did not increase their activity suggesting differences between the efflux process of these molecules and that of beta-lactams. CONCLUSION: This is the first study demonstrating that efflux mechanism plays a key role in the beta-lactam susceptibility of clinical isolates of K. pneumoniae. Such data clearly evidence that the involvement of efflux pumps in beta-lactam resistance is specially underestimated in clinical isolates.

Clinical and Microbiological Aspects of β-Lactam Resistance in Staphylococcus lugdunensis.

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McHardy, Ian H; Veltman, Jennifer; Hindler, Janet; Bruxvoort, Katia; Carvalho, Marissa M; Humphries, Romney M

2017-02-01

Antimicrobial susceptibility results from broth microdilution MIC testing of 993 Staphylococcus lugdunensis isolates recovered from patients at a tertiary care medical center from 2008 to 2015 were reviewed. Ninety-two oxacillin-susceptible isolates were selected to assess the accuracy of penicillin MIC testing, the penicillin disk diffusion test, and three β-lactamase tests, including the cefoxitin-induced nitrocefin test, penicillin cloverleaf assay, and penicillin disk zone edge test. The results of all phenotypic tests were compared to the results of blaZ PCR. The medical records of 62 patients from whom S. lugdunensis was isolated, including 31 penicillin-susceptible and 31 penicillin-resistant strains, were retrospectively reviewed to evaluate the clinical significance of S. lugdunensis isolation, the antimicrobial agents prescribed, if any, and the clinical outcome. MIC testing revealed that 517/993 (52.1%) isolates were susceptible to penicillin and 946/993 (95.3%) were susceptible to oxacillin. The induced nitrocefin test was 100% sensitive and specific for the detection of β-lactamase compared to the blaZ PCR results, whereas the penicillin disk zone edge and cloverleaf tests showed sensitivities of 100% but specificities of only 9.1% and 89.1%, respectively. The penicillin MIC test had 100% categorical agreement with blaZ PCR, while penicillin disk diffusion yielded one major error. Only 3/31 patients with penicillin-susceptible isolates were treated with a penicillin family antimicrobial. The majority of cases were treated with other β-lactams, trimethoprim-sulfamethoxazole, or vancomycin. These data indicate that nearly all isolates of S. lugdunensis are susceptible to narrow-spectrum antimicrobial agents. Clinical laboratories in areas with resistance levels similar to those described here can help promote the use of these agents versus vancomycin by effectively designing their antimicrobial susceptibility reports to convey this message. Copyright

Determination of antimicrobial and heavy metal resistance profiles of some bacteria isolated from aquatic amphibian and reptile species.

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Hacioglu, Nurcihan; Tosunoglu, Murat

2014-01-01

The aim of the present study was to determine the level of antibiotic resistance patterns and distribution of heavy metal resistance of bacterial isolates from aquatic animals (Lissotriton vulgaris, Pelophylax ridibundus, Emys orbicularis, Mauremys rivulata, and Natrix natrix) in Turkey (Kavak Delta). A total of 153 bacteria have been successfully isolated from cloaca and oral samples of the aquatic amphibians and reptilians which were found, namely, Aeromonas sp. (n = 29), Plesiomonas sp. (n = 7), Vibrio sp. (n = 12), Citrobacter sp. (n = 12), Enterobacter sp. (n = 11), Escherichia sp. (n = 22), Klebsiella sp. (n = 22), Edwardsiella sp. (n = 6), Hafnia sp. (n = 1), Proteus sp. (n = 19), Providencia sp. (n = 8), and Pseudomonas sp. (n = 4). In terms of antibiotic and heavy metal susceptibility testing, each isolate was tested against 12 antibiotics and 4 metals. There was a high incidence of resistance to cefoxitin (46.40 %), ampicillin (44.44 %), erythromycin (35.29 %), and a low incidence of resistance to gentamicin (6.53 %), kanamycin (8.49 %), chloramphenicol (9.15 %), and cefotaxime (10.45 %). The multiple antibiotic resistance index of each bacterial species indicated that bacteria from raised amphibians and reptiles have been exposed to tested antibiotics, with results ranging from 0 to 0.58. Most isolates showed tolerance to different concentrations of heavy metals, and minimal inhibition concentrations ranged from100 to >3,200 μg/mL. According to these results, a significant occurrence of bacteria in the internal organs of reptiles and amphibians, with a high incidence of resistance against antibiotics and heavy metals, may risk aquatic animals and the public health. These data appoint the importance of epidemiological surveillance and microbiological monitoring and reinforce the need to implement environment protection programs for amphibian and reptile species.

Antibiotic resistance in bacteria Staphylococcus spp. isolated from samples of raw sheep's milk

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Milan Vasiľ

2016-12-01

Full Text Available From samples of raw sheep's milk were determined results of bacteriological examination from two herds in region of Eastern Slovakia in three years lasting study. The occurrence of Staphylococcus spp. 41.6% (124 was determined from 298 samples. The seven species of staphylococci were on a regular basis isolated: S. epidermidis (34, S. chromogenes (26, S. aureus (16. Alternately have been recorded S. warneri (16, S. schleiferi (15, S. haemolyticus (9 and S. xylosus (8. All isolated pathogens were tested by in vitro test on Mueller-Hinton agar by disc methods on resistance to 10 types of antibiotics.  Highest value of resistance was determined to Penicilin 21.0%, Neomycin 10.5% and Novobiocin 9.7%. Lower resistance was in to Oxacilin 7.2% and Amoxicilin 6.5%. Minimal resistance was founded to Cefoxitin 0.8%, Linkomycin 2.4%, Erytromycin, and Streptomycin 3.2%. Was founded total resistance (21.0% to all antibiotics in S. epidermidis (34 during the three years, S. chromogenes (26 showed resistance to 8 types of antibiotics (12.9%, S. aureus (16 to 6 antibiotics (10.5% and S. warneri (16 to 4 antibiotics (5.6%. It was confirmed that sheep's milk remains a major source of staphylococci. Bacteria in comparison with isolates from cows' raw milk, showed lower values of resistance, but were resistant to more than two antibiotics. Recorded occurrence of resistance in staphylococci may be connected with a minimum use of antibiotics in the treatment of mastitis and other diseases in sheep herds. Reported resistance to the tested antibiotics became the basis for the recommendation to use preparations to treat mastitis in sheep principally by the detection of resistance to antibiotics contained.

Nasal Carriage Rate of Methicillin Resistant Staphylococcus aureus among Health Care Workers at a Tertiary Care Hospital in Kathmandu, Nepal.

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Khatri, S; Pant, N D; Bhandari, R; Shrestha, K L; Shrestha, C D; Adhikari, N; Poudel, A

2017-01-01

Methicillin-resistant Staphylococcus aureus is one of the most common causes of nosocomial infections. Due to its multidrug resistant nature; infections due to Methicillin-resistant Staphylococcus aureus are often very difficult to treat. Colonized health care workers are the important sources of Methicillin-resistant Staphylococcus aureus. The objectives of this study were to determine the nasal carriage rate of Methicillin-resistant Staphylococcus aureus among health care workers at Kathmandu Medical College and Teaching Hospital, Nepal and to assess their antimicrobial susceptibility patterns. A cross sectional study was conducted among 252 health care workers from July to November 2013. Mannitol salt agar was used to culture the nasal swabs. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique following Clinical and Laboratory Standards Institute guidelines. Methicillin-resistant Staphylococcus aureus strains were confirmed by using cefoxitin disc and by determining the minimum inhibitory concentration of oxacillin by agar dilution method. Of 252 healthcare workers, 46(18.3%) were positive for Staphylococcus aureus among which 19(41.3%) were Methicillin-resistant Staphylococcus aureus carriers. Overall rate of nasal carriage of Methicillin-resistant Staphylococcus aureus was 7.5% (19/252).The higher percentages of lab personnel were nasal carriers of S. aureus (31.6%) and Methicillin-resistant Staphylococcus aureus (10.5%).The percentages of nasal carriage of S. aureus (35.7%) and Methicillin-resistant Staphylococcus aureus (14.3%) were highest in the health care workers from post operative department. Higher percentage of Methicillin-resistant Staphylococcus aureus were susceptible toward amikacin (100%) and vancomycin (100%) followed by cotrimoxazole (84.2%). High rates of nasal carriage of S. aureus and Methicillin-resistant Staphylococcus aureus were observed among the healthcare workers, which indicate the need of

Incidence, Antimicrobial Susceptibility, and Toxin Genes Possession Screening of Staphylococcus aureus in Retail Chicken Livers and Gizzards

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Lubna S. Abdalrahman

2015-04-01

Full Text Available Few recent outbreaks in Europe and the US involving Campylobacter and Salmonella were linked to the consumption of chicken livers. Studies investigating Staphylococcus aureus in chicken livers and gizzards are very limited. The objectives of this study were to determine the prevalence, antimicrobial resistance, and virulence of S. aureus and MRSA (Methicillin-Resistant Staphylococcus aureus in retail chicken livers and gizzards in Tulsa, Oklahoma. In this study, 156 chicken livers and 39 chicken gizzards samples of two brands were collected. While one of the brands showed very low prevalence of 1% (1/100 for S. aureus in chicken livers and gizzards, the second brand showed prevalence of 37% (31/95. No MRSA was detected since none harbored the mecA or mecC gene. Eighty seven S. aureus isolates from livers and 28 from gizzards were screened for antimicrobial resistance to 16 antimicrobials and the possession of 18 toxin genes. Resistance to most of the antimicrobials screened including cefoxitin and oxacillin was higher in the chicken gizzards isolates. While the prevalence of enterotoxin genes seg and sei was higher in the gizzards isolates, the prevalence of hemolysin genes hla, hlb, and hld was higher in the livers ones. The lucocidin genes lukE-lukD was equally prevalent in chicken livers and gizzards isolates. Using spa typing, a subset of the recovered isolates showed that they are not known to be livestock associated and, hence, may be of a human origin. In conclusion, this study stresses the importance of thorough cooking of chicken livers and gizzards since it might contain multidrug resistant enterotoxigenic S. aureus. To our knowledge this is the first study to specifically investigate the prevalence of S. aureus in chicken livers and gizzards in the US.

Molecular characterization of extended-spectrum β-lactamase, plasmid-mediated AmpC cephalosporinase and carbapenemase genes among Enterobacteriaceae isolates in five medical centres of East and West Azerbaijan, Iran.

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Sadeghi, Mohammad Reza; Ghotaslou, Reza; Akhi, Mohammad Taghi; Asgharzadeh, Mohammad; Hasani, Alka

2016-11-01

Very little is known about the occurrence and various types of extended-spectrum β-lactamase (ESBL), AmpC and carbapenemase in Iran. The aims of this study were to determine the prevalence of ESBLs, AmpCs and carbapenemase genes among Enterobacteriaceae in Azerbaijan and to characterize the genetic composition of the detected genes. A total of 307 Enterobacteriaceae isolates, recovered from five medical centres, were screened for ESBL, AmpC and carbapenemase activities by the disc diffusion method and phenotypic confirmatory tests. The 162 selected strains (third-generation cephalosporins, cefoxitin- or carbapenem-resistant strains with positive or negative phenotypic confirmatory tests) were selected for multiplex PCR screening for β-lactamase genes, and detected genes were confirmed by sequencing. Of 162 isolates, 156 harboured 1 to 6 β-lactamase genes of 41 types. The most prevalent genes were blaTEM-1 (29.9 %), followed by blaCTX-M-15 (25.7 %). Plasmid-mediated AmpC was detected in 66 strains (21.5 %) alone or in combination with other genes. Carbapenemase-encoding genes were detected in 18 strains (5.8 %) of 27 carbapenem-non-susceptible isolates including 11, 7, 3 and 1 cases of blaOXA-48, blaNDM-1, blaKPC-2 and blaKPC-3 genes, respectively. Interestingly, 148 (94.8 %) of 156 strains with any β-lactamase gene were found to have a multidrug-resistant pattern. The rate of resistance to β-lactams and multidrug-resistant Enterobacteriaceae is high in Azerbaijan. All positive strains for carbapenemase genes were resistant to all β-lactams. The present study reveals the high occurrence of CTX-M-type ESBLs followed by TEM and SHV variants among Enterobacteriaceae isolates. East Azerbaijan seems to be an alarming focus for OXA-48, NDM-1 and KPC dissemination.

Antibiotic sensitivity and resistance in children with urinary tract infection in Sanliurfa.

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Abuhandan, Mahmut; Güzel, Bülent; Oymak, Yeşim; Çiftçi, Halil

2013-06-01

This study aimed to evaluate antibiotic resistance in the province of Şanliurfa and to observe any difference between antibiotic resistance rates. The study comprised 107 children who presented at the pediatric polyclinic with complaints of urinary tract infection with the diagnosis of urinary tract infection and whose urine cultures exhibited bacterial growth. The patients were analyzed with respect to the frequency of proliferating pathogens, sensitivity to the antibiotics used and the rates of developed resistance to the antibiotics. A total of 107 patients aged between 1 year and 15 years were included in the study, encompassing 14 (13.1%) males and 93 (86.9%) females. According to the urine culture results, proliferation of Escherichia coli (E. coli) was observed in 69 (64.5%), Klebsiella spp. in 13 (12.1%), Proteus mirabilis in 9 (8.4%), Staphylococcus aureus in 5 (4.7%), Pseudomonas aeruginosa in 5 (4.7%), Acinetobacter spp. in 3 (2.8%) and Enterococcus spp. in 3 (2.8%) patients. For proliferating E. coli, high resistance rates to ceftriaxone (39.5%), nitrofurantoin (19.7%), ampicillin-sulbactam (64.1%), co-trimoxazole (41.5%), amoxicillinclavulanate (51.7%) and cefuroxime (38.1%) were observed. All of isolated microorganisms were resistant to ampicillin-sulbactam, amoxicillin-clavulanate, co-trimoxazole, ceftriaxone, cefuroxime and cefoxitin in decreasing frequencies. The most effective antimicrobial agents were determined to be imipenem, sulpera-zone, quinolone and aminoglycosides. In our region, parenteral antibiotics that should be selected for the empirical treatment of UTIs in all age groups are the aminoglycosides and 3(rd) generation cephalosporines. In contrast to other studies, these results suggest that co-trimoxazole should be used for children aged 0-1, and 2(nd) generation cephalosporins should be used for the oral treatment of children aged 1-5 due to the low rate of resistance to nitrofurantoin in patients aged over 5 years.

Efeito "in vitro" de antibióticos e rizobactérias no controle de bactérias fitopatogênicas ao Eucalyptus spp. "In vitro" effect of antibiotics and rhizobacteria on the control of phytopathogenic bacteria in Eucalyptus spp.

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Jeane de Fátima Cunha

2006-12-01

Full Text Available Doenças causadas por bactérias constituem um novo desafio à cultura do Eucalyptus spp., podendo, inclusive, limitar o uso de clones suscetíveis. O presente trabalho objetivou avaliar a eficiência de antibióticos e rizobactérias na inibição do crescimento "in vitro" de isolados de bactérias fitopatogênicas ao Eucalyptus spp. na fase de viveiro e de campo. O antibiótico sulfato de amicacina e a rizobactéria S1 (Bacillus subtillis destacaram-se quanto à inibição do crescimento do isolado fitopatogênico IP1-05 (Pseudomonas chichorii, enquanto a cefoxitina causou maior inibição dos isolados BSV16 e RVV11 (Rhizobium sp.. Os antibióticos de uso comercial na área agronômica, Mycoshield (oxitetraciclina e Agrimicina (estreptomicina e tetraciclina foram pouco efetivos. Este trabalho proporciona embasamento a alternativas para controle biológico de doenças bacterianas em mudas de Eucalyptus spp. na fase de viveiro.Diseases caused by bacteria represent a new challenge for Eucalyptus spp. and may also limit the use of susceptible clones. Our study aimed at an evaluation of the efficiency of antibiotics and rhizobacteria in inhibiting "in vitro" growth of phytopathogenic bacteria isolates in Eucalyptus spp. during the nursery stage and in the field. The antibiotic amicacine sulfate and rhizobacterium S1 (Bacillus subtilis stood out inhibiting the growth of the phytopathogenic isolate IP1-05 (Pseudomonas chichorii, whereas cefoxitin caused a greater inhibition of the isolates BSV16 and RVV11 (Rhizobium sp.. The commercial antibiotics for agricultural use Mycoshield (oxitetracycline and Agrimycin (estreptomycin and tetracycline were little effective. This study offers a base for alternatives of biological control of bacterial diseases in Eucalyptus spp. nursery seedlings.

Mycobacterium grossiae sp. nov., a rapidly growing, scotochromogenic species isolated from human clinical respiratory and blood culture specimens.

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Paniz-Mondolfi, Alberto Enrique; Greninger, Alexander L; Ladutko, Lynn; Brown-Elliott, Barbara A; Vasireddy, Ravikiran; Jakubiec, Wesley; Vasireddy, Sruthi; Wallace, Richard J; Simmon, Keith E; Dunn, Bruce E; Jackoway, Gary; Vora, Surabhi B; Quinn, Kevin K; Qin, Xuan; Campbell, Sheldon

2017-11-01

A previously undescribed, rapidly growing, scotochromogenic species of the genus Mycobacterium (represented by strains PB739 T and GK) was isolated from two clinical sources - the sputum of a 76-year-old patient with severe chronic obstructive pulmonary disease, history of tuberculosis exposure and Mycobacterium avium complex isolated years prior; and the blood of a 15-year-old male with B-cell acute lymphoblastic leukaemia status post bone marrow transplant. The isolates grew as dark orange colonies at 25-37 °C after 5 days, sharing features in common with other closely related species. Analysis of the complete 16S rRNA gene sequence (1492 bp) of strain PB739 T demonstrated that the isolate shared 98.8 % relatedness with Mycobacterium wolinskyi. Partial 429 bp hsp65 and 744 bp rpoB region V sequence analyses revealed that the sequences of the novel isolate shared 94.8 and 92.1 % similarity with those of Mycobacterium neoaurum and Mycobacterium aurum, respectively. Biochemical profiling, antimicrobial susceptibility testing, HPLC/gas-liquid chromatography analyses and multilocus sequence typing support the taxonomic status of these isolates (PB739 T and GK) as representatives of a novel species. Both isolates were susceptible to the Clinical and Laboratory Standards Institute recommended antimicrobials for susceptibility testing of rapidly growing mycobacteria including amikacin, ciprofloxacin, moxifloxacin, doxycycline/minocycline, imipenem, linezolid, clarithromycin and trimethropin/sulfamethoxazole. Both isolates PB739 T and GK showed intermediate susceptibility to cefoxitin. We propose the name Mycobacterium grossiae sp. nov. for this novel species and have deposited the type strain in the DSMZ and CIP culture collections. The type strain is PB739 T (=DSM 104744 T =CIP 111318 T ).

Genotypic and phenotypic β-lactam resistance and presence of PVL gene in Staphylococci from dry bovine udder.

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Vinodkumar Kulangara

Full Text Available Dairy cows affected with subclinical mastitis can be sources of virulent, antimicrobial-resistant Staphylococci to humans because of the excretion of the bacteria through their milk. This study focussed on the phenotypic and genotypic antibiotic resistance patterns of Staphylococci isolated from dairy cows in early dry period. Among 96 isolates of Gram positive cocci from 157 cows, 76 were identified as Coagulase Negative Staphylococci and the remaining 20 were Staphylococcus aureus. Typical amplicons of coagulase gene were obtained for all 20 samples of S. aureus with three major coagulase types being identified as giving 627 bp (40%, 910 bp (35% and 710 bp (25% long PCR products. The groEL gene was amplified in PCR of all 76 isolates of Coagulase Negative Staphylococci, and incubation of PCR products with restriction enzyme PvuII yielded three distinct PCR-RFLP fragment patterns bearing resemblance to S. chromogenes and S. hyicus. Highest sensitivity of Coagulase Negative Staphylococci was noted for Azithromycin (92.5% and the least to Tetracyclines (76.3%, whereas for S. aureus, it was Cefoperazone (95% and Azithromycin (72.2% respectively. Phenotypic resistance to Oxacillin (25 isolates, and Cefoxitin (11 isolates was detected by dilution method with a commercial strip (Ezy MICTM. Genotypic resistance to β-Lactam antibiotics was found in 65 (34 with mecA gene and 31 with blaZ gene isolates. Eighteen isolates possessed both the genes, with the PVL gene for virulence being detected in five of them. Nine isolates which had mecA gene were phenotypically susceptible to oxacillin while phenotypic resistance to oxacillin was observed in seven isolates that did not have either mecA or blaZ gene. This is the first report of persistent Staphylococcal infections possessing PVL gene and high level of genotypic resistance to β-Lactam antibiotics in small- holder dairy cattle from India.

Genotypic and phenotypic β-lactam resistance and presence of PVL gene in Staphylococci from dry bovine udder

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Sivasailam, Asok; Sasidharan, Suchithra; Kollannur, Justin Davis; Syam, Radhika

2017-01-01

Dairy cows affected with subclinical mastitis can be sources of virulent, antimicrobial-resistant Staphylococci to humans because of the excretion of the bacteria through their milk. This study focussed on the phenotypic and genotypic antibiotic resistance patterns of Staphylococci isolated from dairy cows in early dry period. Among 96 isolates of Gram positive cocci from 157 cows, 76 were identified as Coagulase Negative Staphylococci and the remaining 20 were Staphylococcus aureus. Typical amplicons of coagulase gene were obtained for all 20 samples of S. aureus with three major coagulase types being identified as giving 627 bp (40%), 910 bp (35%) and 710 bp (25%) long PCR products. The groEL gene was amplified in PCR of all 76 isolates of Coagulase Negative Staphylococci, and incubation of PCR products with restriction enzyme PvuII yielded three distinct PCR-RFLP fragment patterns bearing resemblance to S. chromogenes and S. hyicus. Highest sensitivity of Coagulase Negative Staphylococci was noted for Azithromycin (92.5%) and the least to Tetracyclines (76.3%), whereas for S. aureus, it was Cefoperazone (95%) and Azithromycin (72.2%) respectively. Phenotypic resistance to Oxacillin (25 isolates), and Cefoxitin (11 isolates) was detected by dilution method with a commercial strip (Ezy MICTM). Genotypic resistance to β-Lactam antibiotics was found in 65 (34 with mecA gene and 31 with blaZ gene) isolates. Eighteen isolates possessed both the genes, with the PVL gene for virulence being detected in five of them. Nine isolates which had mecA gene were phenotypically susceptible to oxacillin while phenotypic resistance to oxacillin was observed in seven isolates that did not have either mecA or blaZ gene. This is the first report of persistent Staphylococcal infections possessing PVL gene and high level of genotypic resistance to β-Lactam antibiotics in small- holder dairy cattle from India. PMID:29091956

In vivo selection of resistant E. coli after ingestion of milk with added drug residues.

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Richard Van Vleck Pereira

Full Text Available Antimicrobial resistance represents a major global threat to modern medicine. In vitro studies have shown that very low concentrations of drugs, as frequently identified in the environment, and in foods and water for human and animal consumption, can select for resistant bacteria. However, limited information is currently available on the in vivo impact of ingested drug residues. The objective of our study was to evaluate the effect of feeding preweaned calves milk containing antimicrobial drug residues (below the minimum inhibitory concentration, similar to concentrations detected in milk commonly fed to dairy calves, on selection of resistant fecal E. coli in calves from birth to weaning. At birth, thirty calves were randomly assigned to a controlled feeding trial where: 15 calves were fed raw milk with no drug residues (NR, and 15 calves were fed raw milk with drug residues (DR by adding ceftiofur, penicillin, ampicillin, and oxytetracycline at final concentrations in the milk of 0.1, 0.005, 0.01, and 0.3 µg/ml, respectively. Fecal samples were rectally collected from each calf once a week starting at birth prior to the first feeding in the trial (pre-treatment until 6 weeks of age. A significantly greater proportion of E. coli resistant to ampicillin, cefoxitin, ceftiofur, streptomycin and tetracycline was observed in DR calves when compared to NR calves. Additionally, isolates from DR calves had a significant decrease in susceptibility to ceftriaxone and ceftiofur when compared to isolates from NR calves. A greater proportion of E. coli isolates from calves in the DR group were resistant to 3 or more antimicrobial drugs when compared to calves in the ND group. These findings highlight the role that low concentrations of antimicrobial drugs have on the evolution and selection of resistance to multiple antimicrobial drugs in vivo.

Prevalence of Salmonella enterica, Listeria monocytogenes, and pathogenic Escherichia coli in bulk tank milk and milk filters from US dairy operations in the National Animal Health Monitoring System Dairy 2014 study.

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Sonnier, Jakeitha L; Karns, Jeffrey S; Lombard, Jason E; Kopral, Christine A; Haley, Bradd J; Kim, Seon-Woo; Van Kessel, Jo Ann S

2018-03-01

The dairy farm environment is a well-documented reservoir for zoonotic pathogens such as Salmonella enterica, Shiga-toxigenic Escherichia coli, and Listeria monocytogenes, and humans may be exposed to these pathogens via consumption of unpasteurized milk and dairy products. As part of the National Animal Health Monitoring System Dairy 2014 study, bulk tank milk (BTM, n = 234) and milk filters (n = 254) were collected from a total of 234 dairy operations in 17 major dairy states and analyzed for the presence of these pathogens. The invA gene was detected in samples from 18.5% of operations and Salmonella enterica was isolated from 18.0% of operations. Salmonella Dublin was detected in 0.7% of operations. Sixteen Salmonella serotypes were isolated, and the most common serotypes were Cerro, Montevideo, and Newport. Representative Salmonella isolates (n = 137) were tested against a panel of 14 antimicrobials. Most (85%) were pansusceptible; the remaining were resistant to 1 to 9 antimicrobials, and within the resistant strains the most common profile was resistance to ampicillin/clavulanic acid, ampicillin, cefoxitin, ceftiofur, ceftriaxone, chloramphenicol, streptomycin, sulfisoxazole, and tetracycline. Listeria spp. were isolated from 19.9% of operations, and L. monocytogenes was isolated from 3.0% of operations. Serogroups 1/2a and 1/2b were the most common, followed by 4b and 4a. One or more E. coli virulence genes were detected in the BTM from 30.5% of operations and in the filters from 75.3% of operations. A combination of stx 2 , eaeA, and γ-tir genes was detected in the BTM from 0.5% of operations and in the filters from 6.6% of operations. The results of this study indicate an appreciable prevalence of bacterial pathogens in BTM and filters, including serovars known to infect humans. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Evaluation of the Verigene Gram-positive blood culture nucleic acid test for rapid detection of bacteria and resistance determinants.

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Wojewoda, Christina M; Sercia, Linda; Navas, Maria; Tuohy, Marion; Wilson, Deborah; Hall, Geraldine S; Procop, Gary W; Richter, Sandra S

2013-07-01

Rapid identification of pathogens from blood cultures can decrease lengths of stay and improve patient outcomes. We evaluated the accuracy of the Verigene Gram-positive blood culture (BC-GP) nucleic acid test for investigational use only (Nanosphere, Inc., Northbrook, IL) for the identification of Gram-positive bacteria from blood cultures. The detection of resistance genes (mecA in Staphylococcus aureus and Staphylococcus epidermidis and vanA or vanB in Enterococcus faecium and Enterococcus faecalis) by the BC-GP assay also was assessed. A total of 186 positive blood cultures (in BacT/Alert FA bottles) with Gram-positive cocci observed with Gram staining were analyzed using the BC-GP assay. The BC-GP results were compared with the identification and susceptibility profiles obtained with routine methods in the clinical laboratory. Discordant results were arbitrated with additional biochemical, cefoxitin disk, and repeat BC-GP testing. The initial BC-GP organism identification was concordant with routine method results for 94.6% of the blood cultures. Only 40% of the Streptococcus pneumoniae identifications were correct. The detection of the mecA gene for 69 blood cultures with only S. aureus or S. epidermidis was concordant with susceptibility testing results. For 3 of 6 cultures with multiple Staphylococcus spp., mecA detection was reported but was correlated with oxacillin resistance in a species other than S. aureus or S. epidermidis. The detection of vanA agreed with susceptibility testing results for 45 of 46 cultures with E. faecalis or E. faecium. Comparison of the mean times to results for each organism group showed that BC-GP results were available 31 to 42 h earlier than phenotypic identifications and 41 to 50 h earlier than susceptibility results.

Cefmetazole for bacteremia caused by ESBL-producing enterobacteriaceae comparing with carbapenems.

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Fukuchi, Takahiko; Iwata, Kentaro; Kobayashi, Saori; Nakamura, Tatsuya; Ohji, Goh

2016-08-18

ESBL (Extended spectrum beta-lactamase) producing enterobacteriaceae are challenging organisms with little treatment options. Carbapenems are frequently used, but the emergence of carbapenem resistant enterobacteriaceae is a concerning issue, which may hinder the use of carbapenems. Although cephamycins such as cefoxitin, cefmetazole or cefotetan are effective against ESBL-producers in vitro, there are few clinical data demonstrating effects against bacteremia caused by these organisms. We performed a retrospective observational study on cases of bacteremia caused by ESBL-producers to investigate the efficacy of cefmetazole compared with carbapenems. We also evaluated whether the trend of antibiotic choice changed over years. Sixty-nine patients (male 34, age 69.2 ± 14.4), including two relapse cases, were reviewed for this analysis. The most common causative organisms were Escherichia coli (64, 93 %), followed by Klebsiella pneumoniae and K. oxytoca (2 each, 4 %). The group that received carbapenem therapy (43, 62 %) had increased severity in the Pittsburgh Bacteremic score than the group that received cefmetazole therapy, (1.5 ± 1.5 vs 2.5 ± 2.1, p = 0.048), while analysis of other factors didn't reveal any statistical differences. Five patients in the carbapenem group and one patient in the cefmetazole group died during the observation period (p = 0.24). CTX-M-9 were predominant in this series (59 %). Infectious disease physicians initially recommended carbapenems at the beginning of the current research period, which gradually changed over time favoring the use of cefmetazole instead (p = 0.002). Cefmetazole may be safely given to patients with bacteremia caused by ESBL-producers as a definitive therapy, if one can select out relatively stable patients.

Antimicrobial Resistance and Cytotoxicity of Citrobacter spp. in Maanshan Anhui Province, China

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Liyun Liu

2017-07-01

Full Text Available Objectives:Citrobacter spp. especially Citrobacter freundii, is frequently causing nosocomial infections, and increasingly becoming multi-drug resistant (MDR. In this study, we aimed to determine the genetic diversity and relationships of Citrobacter spp. from diarrheal patients and food sources, their antimicrobial resistance profiles and in vitro virulence properties.Methods: Sixty two Citrobacter isolates, including 13 C. freundii, 41 C. youngae and eight C. braakii isolates, were obtained from human diarrheal patients and food sources. Multilocus Sequence Typing (MLST of seven housekeeping genes and antimicrobial susceptibility testing using the broth microdilution method according to CLSI recommendations were carried out. Adhesion and cytotoxicity to HEp-2 cells were performed. PCR and sequencing were used to identify blaCTX−M, blaSHV, blaTEM and qnr genes.Results: The 62 isolates were divided into 53 sequence types (STs with all STs being novel, displaying high genetic diversity. ST39 was a predominant ST shared by 5 C. youngae strains isolated from four foods and a diarrheal patient. All isolates were resistant to cefoxitin, and sensitive to imipenem, meropenem and amikacin. The majority of Citrobacter isolates (61.3% were MDR of three or more antibiotics out of the 22 antibiotics tested. Two C. freundii isolates each carried the blaTEM−1 gene and a variant of qnrB77. Three Citrobacter isolates each carried qnrS1 and aac(6'-Ib-cr genes. Seven isolates that showed strong cytotoxicity to HEp-2 cells were MDR.Conclusions:Citrobacter spp. from human and food sources are diverse with variation in virulence properties and antibiotic resistance profiles. Food may be an important source of Citrobacter species in transmission to humans. C. freundii and C. youngae are potential foodborne pathogens.

Minimum inhibitory concentration of vancomycin to methicillin resistant Staphylococcus aureus isolated from different clinical samples at a tertiary care hospital in Nepal

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Arjun Ojha Kshetry

2016-07-01

Full Text Available Abstract Background Methicillin resistant Staphylococcus aureus (MRSA has evolved as a serious threat to public health. It has capability to cause infections not only in health care settings but also in community. Due to the multidrug resistance shown by MRSA, there are limited treatment options for the infections caused by this superbug. Vancomycin is used as the drug of choice for the treatment of infections caused by MRSA. Different studies from all around the world have documented the emergence of strains of S. aureus those are intermediate sensitive or resistant to vancomycin. And recently, there have been reports of reduced susceptibility of MRSA to vancomycin, from Nepal also. So the main purpose of this study was to determine the minimum inhibitory concentration (MIC of vancomycin to methicillin resistant S. aureus isolated from different clinical specimens. Methods Total 125 strains of S. aureus isolated from different clinical samples at KIST Medical College and Teaching Hospital, Lalitpur, Nepal from Nov 2012 to June 2013, were subjected to MRSA detection by cefoxitin disc diffusion method. The minimum inhibitory concentrations of vancomycin to confirmed MRSA strains were determined by agar dilution method. Yellow colored colonies in mannitol salt agar, which were gram positive cocci, catalase positive and coagulase positive were confirmed to be S. aureus. Results Among, total 125 S. aureus strains isolated; 47(37.6% were MRSA. Minimum inhibitory concentrations of vancomycin to the strains of MRSA ranged from 0.125 μg/ml to 1 μg/ml. Conclusion From our findings we concluded that the rate of isolation of MRSA among all the strains of S. aureus isolated from clinical samples was very high. However, none of the MRSA strains were found to be vancomycin intermediate-sensitive or vancomycin-resistant.

Puerperal infections.

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Eschenbach, D A; Wager, G P

1980-12-01

This comprehensive review on puerperal infections covers risk factors, causative bacteria, pathophysiology, diagnosis, therapy of specific entities, and prevention. Puerperal infection is problematic to define especially with antibiotics that change the course of fever. I may present as endometritis (most common), myometritis, parametritis, pelvic abscess, salpingitis, septic pelvic thrombophlebitis or septicemia, and also includes infections of the urinary tract, episiotomy, surgical wounds, lacerations or breast. Each of these is discussed in terms of contributing factors, microbiology, clinical findings, diagnosis, treatment, prevention and complications. Risk factors in general are cesarean section, premature rupture of the membranes, internal fetal monitoring, general anesthesia, pelvic examinations. The most common bacterial involved are group B and other streptococci, E. coli, Gardnerella vaginalis, Gram positive anaerobic cocci, Mycoplasma and pre-existing Chlamydial infections. Diagnosis of the causative organism is difficult because of polyinfection and difficulty of getting a sterile endometrial swab. Diagnosis of the infection is equally difficult because of the wide variety of symptoms: fever, abnormal lochia, tachycardia, tenderness, mass and abnormal bowel sounds are common. Therapy depends of the responsible microorganism, although 3 empirical tactics are suggested while awaiting results of culture: 1) choose an antibiotic for the most common aerobic bacteria; 2) an antibiotic effective against B. fragilis and one for aerobic bacteria, e.g. clindamycin and an aminoglycoside; 3) a nontoxic antibiotic active against most aerobic and anaerobic organisms, e.g. doxycycline or cefoxitin. An example of an infection recently described is pudendal-paracervical block infection, often signaled by severe hip pain. It is associated with vaginal bacteria, is usually complicated by abscess even with antibiotic coverage, and may end in paraplegia or fatal sepsis

Evaluation of meat, fruit and vegetables from retail stores in five United Kingdom regions as sources of extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant Escherichia coli.

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Randall, L P; Lodge, M P; Elviss, N C; Lemma, F L; Hopkins, K L; Teale, C J; Woodford, N

2017-01-16

We determined the prevalence and types of extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant Escherichia coli in raw retail beef, chicken, pork, fruit and vegetables in five UK regions in 2013-14. Raw meat (n=397), and fruit and vegetable samples (n=400) were purchased from retail stores in London, East Anglia, North West England, Scotland and Wales. Samples were tested for the presence of ESBL-producing E. coli by plating enriched samples on CHROMagar CTX and CHROMagar ESBL, for AmpC-type E. coli by plating on "CHROMagar FOX" (CHROMagar ECC+16mg/L cefoxitin), and for carbapenem-resistant E. coli by plating on CHROMagar KPC. Additionally, pre-enrichment counts were performed on the above agars, and on CHROMagar ECC. Isolates of interest were characterised by MALDI-ToF to confirm identification, by PCR for bla CIT, bla CTX-M, bla OXA , bla SHV and bla TEM genes; ESBL or bla CIT genes were sequenced. Only 1.9% and 2.5% of beef and pork samples, respectively were positive for ESBL-producing E. coli after enrichment compared with 65.4% of chicken samples. 85.6% positive samples from chicken meat carried bla CTX-M-1 ; bla CTX-M-15 was not detected. None of the fruits or vegetables yielded ESBL-producing E. coli and none of the meat, fruit or vegetable samples yielded carbapenem-resistant E. coli. Retail chicken was more frequently a source of ESBL-producing E. coli than were beef, pork, fruit or vegetables. None of the foodstuffs yielded E. coli with CTX-M-15 ESBL, which dominates in human clinical isolates in the UK, and none yielded carbapenem-resistant E. coli. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Occurrence and antimicrobial resistance of Salmonella spp. isolated from food other than meat in Poland

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Łukasz Mąka

2015-09-01

Full Text Available Introduction and objectives. Antimicrobial resistance of pathogenic bacteria can result in therapy failure, increased hospitalization, and increased risk of death. In Poland, [i]Salmonella[/i] spp. is a major bacterial agent of food poisoning. The majority of studies on antimicrobial resistance in [i]Salmonella[/i] spp. isolates from food have focused on meat products as the source of this pathogen. In comparison, this study examines the antimicrobial susceptibility of [i]Salmonella[/i] spp. isolated from retail food products other than meat in Poland. Materials and Methods. A collection of 122 [i]Salmonella[/i] spp. isolates were isolated in Poland in 2008–2012 from foods other than meat: confectionery products, eggs, fruits, vegetables, spices and others. The resistance of these isolates to 19 antimicrobial agents was tested using the disc diffusion method. Results. [i]Salmonella[/i] Enteritidis was the most frequently identified serotype (84.4% of all tested isolates. In total, 42.6% of the [i]Salmonella[/i] spp. isolates were resistant to antibiotics. The highest frequencies of resistance were observed in isolates from 2009 (60.0% and 2012 (59.5%. Antibiotic resistance was most prevalent among [i]Salmonella[/i] spp. isolated from egg-containing food samples (68.0%. Resistance to nalidixic acid was most common and was observed in 35.2% of all tested isolates. The isolates were less frequently resistant to sulphonamides (6.6%, ampicillin (4.9%, amoxicillin/clavulanic acid (2.5% and to streptomycin, cefoxitin, gentamicin and tetracycline (1.6%. Only one isolate showed resistance to chloramphenicol. Four isolates displayed multiresistance. Conclusions. Although, the level of resistance and multiresistance of [i]Salmonella[/i] spp. isolates from non-meat foods was lower than in those from meat products, the presence of these resistant bacteria poses a real threat to the health of consumers.

The Soil Microbiota Harbors a Diversity of Carbapenem-Hydrolyzing β-Lactamases of Potential Clinical Relevance.

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Gudeta, Dereje Dadi; Bortolaia, Valeria; Amos, Greg; Wellington, Elizabeth M H; Brandt, Kristian K; Poirel, Laurent; Nielsen, Jesper Boye; Westh, Henrik; Guardabassi, Luca

2016-01-01

The origin of carbapenem-hydrolyzing metallo-β-lactamases (MBLs) acquired by clinical bacteria is largely unknown. We investigated the frequency, host range, diversity, and functionality of MBLs in the soil microbiota. Twenty-five soil samples of different types and geographical origins were analyzed by antimicrobial selective culture, followed by phenotypic testing and expression of MBL-encoding genes in Escherichia coli, and whole-genome sequencing of MBL-producing strains was performed. Carbapenemase activity was detected in 29 bacterial isolates from 13 soil samples, leading to identification of seven new MBLs in presumptive Pedobacter roseus (PEDO-1), Pedobacter borealis (PEDO-2), Pedobacter kyungheensis (PEDO-3), Chryseobacterium piscium (CPS-1), Epilithonimonas tenax (ESP-1), Massilia oculi (MSI-1), and Sphingomonas sp. (SPG-1). Carbapenemase production was likely an intrinsic feature in Chryseobacterium and Epilithonimonas, as it occurred in reference strains of different species within these genera. The amino acid identity to MBLs described in clinical bacteria ranged between 40 and 69%. Remarkable features of the new MBLs included prophage integration of the encoding gene (PEDO-1), an unusual amino acid residue at a key position for MBL structure and catalysis (CPS-1), and overlap with a putative OXA β-lactamase (MSI-1). Heterologous expression of PEDO-1, CPS-1, and ESP-1in E. coli significantly increased the MICs of ampicillin, ceftazidime, cefpodoxime, cefoxitin, and meropenem. Our study shows that MBL producers are widespread in soil and include four genera that were previously not known to produce MBLs. The MBLs produced by these bacteria are distantly related to MBLs identified in clinical samples but constitute resistance determinants of clinical relevance if acquired by pathogenic bacteria. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

CLINICAL ISOLATES OF MECA, METHICILLIN, VANCOMYCIN RESISTANCE S. AUREUS; ESBLs PRODUCING K.PNEUMONIA, E.COLI, P. AUREGENOSA FROM VARIOUS CLINICAL SOURCE AND ITS ANTIMICROBIAL RESISTANCE PATTERNS

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Ismail Mahmud Ali, Amirthalingam R

2015-01-01

Full Text Available Background and Objective: Antimicrobial resistance has turned into a key medical and public health crisis globally since the injudicious use of magic bullets (drugs. Aim of this study is focused on the clinical isolate and their percentages of resistant to antibiotics in gram positive bacteria such as MRSA, VRSA, and MSSA are common causes of nosocomical, skin structure infections, bacteremia and infection of other systems; ESBLs producing Enterobacteriaceae (E. coli, Klebsiella spp. is common agent of urinary tract, bloodstream, pulmonary and intra-abdominal infections and carbapenem resistant P. aeruginosa with its complete antimicrobial patterns which are currently practiced in this population. Methods: There are one hundred and fourteen (114 various clinical isolates, isolated from various clinical samples like throat swab, urine, pus, sputum, and blood culture, identified as specific isolate with resistance patterns were analyzed by BD phoenix-100 the auto analyzer. Results: Off 114 clinical isolate, 6 mecA-mediated resistance (cefoxitin>8mgc/ml, 11 methicillin resistance, 18 β lactam/βlactamase inhibitor, 12 methicillin sensitive and 3 vancomycin (>16µg/ml resistance S. aureus have been isolated from overall 50 isolate of S.aureus. In addition, there are 27 P.aeruginosa, 15 ESBLs from overall of 25 K. pneumoniae and 7 ESBLs out of 12 Escherichia coli species have been isolated. The resistance and susceptibility pattern percentages have been graphically represented for each isolates. Conclusion: Current study revealed that the drug classes of β lactam/βlactamase inhibitor having high resistance rate with S.aureus, P.aureginosa, K. pneumoniae and E. coli isolate. Also, some of other drug classes such as cepham and tetracycline having higher resistance rate with P.aureginosa and K.pneumoniae. In addition, the vancomycin resistances S. aureus have been isolated and reported as first time in this population.

Phenotypic and genotypic characterization of antibiotic resistance of methicillin-resistant Staphylococcus aureus isolated from hospital food

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Farhad Safarpoor Dehkordi

2017-10-01

Full Text Available Abstract Background Pathogenic biotypes of the Methicillin-resistant Staphylococcus aureus (MRSA strains are considered to be one of the major cause of food-borne diseases in hospitals. The present investigation was done to study the pattern of antibiotic resistance and prevalence of antibiotic resistance genes of different biotypes of the MRSA strains isolated from various types of hospital food samples. Methods Four-hundred and eighty-five raw and cooked hospital food samples were cultured and MRSA strains were identified using the oxacillin and cefoxitin disk diffusion tests and mecA-based PCR amplification. Isolated strains were subjected to biotyping and their antibiotic resistance patterns were analyzed using the disk diffusion and PCR methods. Results Prevalence of S. aureus and MRSA were 9.69 and 7.62%, respectively. Meat and chicken barbecues had the highest prevalence of MRSA. Prevalence of bovine, ovine, poultry and human-based biotypes in the MRSA strains were 8.10, 8.10, 32.43 and 48.64%, respectively. All of the MRSA strains recovered from soup, salad and rice samples were related to human-based biotypes. MRSA strains harbored the highest prevalence of resistance against penicillin (100%, ceftaroline (100%, tetracycline (100%, erythromycin (89.18% and trimethoprim-sulfamethoxazole (83.78%. TetK (72.97%, ermA (72.97%, msrA (64.86% and aacA-D (62.16% were the most commonly detected antibiotic resistance genes. Conclusions Pattern of antibiotic resistance and also distribution of antibiotic resistance genes were related to the biotype of MRSA strains. Presence of multi-drug resistance and also simultaneous presence of several antibiotic resistance genes in some MRSA isolates showed an important public health issue Further researches are required to found additional epidemiological aspects of the MRSA strains in hospital food samples.

Rapid optical determination of β-lactamase and antibiotic activity

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2014-01-01

Background The absence of rapid tests evaluating antibiotic susceptibility results in the empirical prescription of antibiotics. This can lead to treatment failures due to escalating antibiotic resistance, and also furthers the emergence of drug-resistant bacteria. This study reports a rapid optical method to detect β-lactamase and thereby assess activity of β-lactam antibiotics, which could provide an approach for targeted prescription of antibiotics. The methodology is centred on a fluorescence quenching based probe (β-LEAF – β-Lactamase Enzyme Activated Fluorophore) that mimics the structure of β-lactam antibiotics. Results The β-LEAF assay was performed for rapid determination of β-lactamase production and activity of β-lactam antibiotic (cefazolin) on a panel of Staphylococcus aureus ATCC strains and clinical isolates. Four of the clinical isolates were determined to be lactamase producers, with the capacity to inactivate cefazolin, out of the twenty-five isolates tested. These results were compared against gold standard methods, nitrocefin disk test for β-lactamase detection and disk diffusion for antibiotic susceptibility, showing results to be largely consistent. Furthermore, in the sub-set of β-lactamase producers, it was demonstrated and validated that multiple antibiotics (cefazolin, cefoxitin, cefepime) could be assessed simultaneously to predict the antibiotic that would be most active for a given bacterial isolate. Conclusions The study establishes the rapid β-LEAF assay for β-lactamase detection and prediction of antibiotic activity using S. aureus clinical isolates. Although the focus in the current study is β-lactamase-based resistance, the overall approach represents a broad diagnostic platform. In the long-term, these studies form the basis for the development of assays utilizing a broader variety of targets, pathogens and drugs. PMID:24708478

Molecular epidemiology and antimicrobial resistance of Salmonella Typhimurium DT104 on Ontario swine farms

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Farzan, Abdolvahab; Friendship, Robert M.; Poppe, Cornelis; Martin, Laura; Dewey, Catherine E.; Funk, Julie

2008-01-01

This study was conducted to examine antimicrobial resistances, plasmid profiles, and pulsed-field gel electrophoresis patterns of 80 Salmonella Typhimurium (including var. Copenhagen) DT104 strains (including DT104a and DT104b) recovered from pig and environmental fecal samples on 17 swine farms in Ontario. No resistance was observed to amoxicillin/clavulanic acid, apramycin, carbadox, cephalothin, ceftriaxone, ceftiofur, cefoxitin, ciprofloxacin, nalidixic acid, trimethoprim, and tobramycin. However, the isolates exhibited resistance against 4 to 10 antimicrobials with the most frequent resistance being to sulfonamides (Su), ampicillin (A), streptomycin (S), spectinomycin (Sp), chloramphenicol (C), tetracycline (T), and florfenicol (F). Thirteen distinct resistance patterns were determined but 88% of isolates shared the typical resistance pattern “ACSpSSuT.” Twelve different plasmid profiles were observed; the 62 MDa virulence-associated plasmid was detected in 95% of the isolates. The 2.1 MDa plasmid was the second most frequent one, which was harbored by 65% isolates. The isolates were classified into 23 distinct genotypes by PFGE-SpeI + BlnI when difference in at least one fragment was defined as a distinct genotype. In total, 39 distinct “types” were observed when defining a “type” based on the combination of antimicrobial resistance, plasmid pattern, and PFGE-SpeI + BlnI for each isolate. The highest diversity was 0.96 (95% CI: 0.92, 0.96) for the “type” described above followed by 0.92 (95% CI: 0.88, 0.93) for PFGE-SpeI + BlnI. The diversity of DT104 isolates indicates there might be multiple sources for this microorganism on swine farms. This knowledge might be used to track these sources, as well as to study the extent of human salmonellosis attributed to pork compared to food products derived from other food-producing animals. PMID:18505209

Chronological Change of Resistance to β-Lactams in Salmonella enterica serovar Infantis Isolated from Broilers in Japan.

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Chuma, Takehisa; Miyasako, Daisuke; Dahshan, Hesham; Takayama, Tomoko; Nakamoto, Yuko; Shahada, Francis; Akiba, Masato; Okamoto, Karoku

2013-01-01

Epidemiologic surveillance study was conducted in southern Japan to determine the antimicrobial resistance phenotypes and characterize the β-lactamase genes and the plasmids harboring these genes in Salmonella enterica serovar Infantis (S. Infantis) isolates from broilers. Between January, 2007 and December, 2008, a total of 1,472 fecal samples were collected and examined at the Laboratory of Veterinary Public Health, Kagoshima University, Japan. In 93 (6.3%) isolates recovered, 33 (35.5%) isolates showed resistance to cefotaxime, an extended-spectrum cephalosporin (ESC), conferred by TEM-20, TEM-52 and CTX-M-25 extended-spectrum β-lactamases (ESBLs). In addition to ESC-resistance, eight (8.6%) isolates exhibited resistance to cefoxitin mediated by CMY-2 AmpC β-lactamase. Plasmid analysis and polymerase chain reaction replicon typing revealed the bla TEM-20 and bla CMY-2 genes were associated with IncP plasmids, bla TEM-52 was linked with a non-typable plasmid and bla CTX-M-25 was carried by an IncA/C plasmid. Non-β-lactam resistance to streptomycin, sulfamethoxazole, and oxytetracycline encoded by the aadA1, sul1, and tet(A) genes, respectively, was found in 86 (92.5%) isolates. Resistance to kanamycin and ofloxacin was exhibited in 12 (12.9%) and 11 (11.8%) isolates, respectively, the former was mediated by aphA1-Iab. These data indicate that S. Infantis isolates producing ESBLs and AmpC β-lactamase have spread among broiler farms in Japan. These data demonstrated that the incidence of ESC-resistant S. Infantis carrying bla TEM-52 remarkably increased and S. Infantis strains harboring bla CMY-2, bla TEM-20, or bla CTX-M-25 genes emerged from broilers in Japan for the first time in 2007 and 2008.

Anaerobic bacteria colonizing the lower airways in lung cancer patients

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Anna Malm

2011-07-01

Full Text Available Anaerobes comprise most of the endogenous oropharyngeal microflora, and can cause infections of airways in lung cancer patients who are at high risk for respiratory tract infections. The aim of this study was to determine the frequency and species diversity of anaerobes in specimens from the lower airways of lung cancer patients. Sensitivity of the isolates to conventional antimicrobial agents used in anaerobe therapy was assessed. Respiratory secretions obtained by bronchoscopy from 30 lung cancer patients were cultured onto Wilkins- -Chalgren agar in anaerobic conditions at 37°C for 72–96 hours. The isolates were identified using microtest Api 20A. The minimal inhibitory concentrations for penicillin G, amoxicillin/clavulanate, piperacillin/tazobactam, cefoxitin, imipenem, clindamycin, and metronidazole were determined by E-test. A total of 47 isolates of anaerobic bacteria were detected in 22 (73.3% specimens. More than one species of anaerobe was found in 16 (53.3% samples. The most frequently isolated were Actinomyces spp. and Peptostreptococcus spp., followed by Eubacterium lentum, Veillonella parvula, Prevotella spp., Bacteroides spp., Lactobacillus jensenii. Among antibiotics used in the study amoxicillin/clavulanate and imipenem were the most active in vitro (0% and 2% resistant strains, respectively. The highest resistance rate was found for penicillin G and metronidazole (36% and 38% resistant strains, respectively. The results obtained confirm the need to conduct analyses of anaerobic microflora colonizing the lower respiratory tract in patients with lung cancer to monitor potential etiologic factors of airways infections, as well as to propose efficient, empirical therapy. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 2, pp. 263–266

Microbiological and molecular characterization of Staphylococcus hominis isolates from blood.

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Soraya Mendoza-Olazarán

Full Text Available BACKGROUND: Among Coagulase-Negative Staphylococci (CoNS, Staphylococcus hominis represents the third most common organism recoverable from the blood of immunocompromised patients. The aim of this study was to characterize biofilm formation, antibiotic resistance, define the SCCmec (Staphylococcal Chromosomal Cassette mec type, and genetic relatedness of clinical S. hominis isolates. METHODOLOGY: S. hominis blood isolates (n = 21 were screened for biofilm formation using crystal violet staining. Methicillin resistance was evaluated using the cefoxitin disk test and the mecA gene was detected by PCR. Antibiotic resistance was determined by the broth microdilution method. Genetic relatedness was determined by pulsed-field gel electrophoresis (PFGE and SCCmec typed by multiplex PCR using two different methodologies described for Staphylococcus aureus. RESULTS: Of the S. hominis isolates screened, 47.6% (10/21 were categorized as strong biofilm producers and 23.8% (5/21 as weak producers. Furthermore, 81% (17/21 of the isolates were methicillin resistant and mecA gene carriers. Resistance to ampicillin, erythromycin, and trimethoprim was observed in >70% of isolates screened. Each isolate showed a different PFGE macrorestriction pattern with similarity ranging between 0-95%. Among mecA-positive isolates, 14 (82% harbored a non-typeable SCCmec type: eight isolates were not positive for any ccr complex; four contained the mec complex A ccrAB1 and ccrC, one isolate contained mec complex A, ccrAB4 and ccrC, and one isolate contained the mec complex A, ccrAB1, ccrAB4, and ccrC. Two isolates harbored the association: mec complex A and ccrAB1. Only one strain was typeable as SCCmec III. CONCLUSIONS: The S. hominis isolates analyzed were variable biofilm producers had a high prevalence of methicillin resistance and resistance to other antibiotics, and high genetic diversity. The results of this study strongly suggested that S. hominis isolates harbor

Prevalence of antibiotic resistant Staphylococcus aureus from raw milk samples collected from the local vendors in the region of Tirupathi, India

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Sudhanthirakodi Sudhanthiramani

2015-04-01

Full Text Available Aim: The study was carried out with the aim to identify the suitability of the milk for consumer use with special reference to Staphylococcus aureus from milk samples collected from various local vendors and determine the antibiotic susceptibility pattern of those positive isolates. Materials and Methods: A total of 110 milk samples were collected from the local milk vendors in and around Tirupathi region of India. All the samples were enriched with buffered peptone water in 9:1 ratio and the then inoculated on baird parker agar medium with added 2% egg yolk tellurite emulsion as selective medium for S.aureus and confirmed with mannitol salt agar, Gram’s staining and biochemical tests. The typical cultural characters with coagulase-positive samples were taken as positive samples the positive samples were tested for antibiotic susceptibility with 10 different antibiotics by employing disc diffusion method. Results: Prevalence of coagulase-positive S. aureus was 39.09% (43/110 from the milk samples. The antibiotic susceptibility test of positive isolates showed high resistant toward penicillin G 37/43 (86.04% and ampicillin 32/43 (74.42%, and also showed resistant to methicillin 6/43 (13.95%, cephalothin 6/43 (13.95%, tetracycline 6/43 (13.95%, ciprofloxacin 4/43 (9.30%, enrofloxacin 3/43 (6.97%, cefoxitin 2/43 (4.65%, gentamicin 2/43 (4.65%, and co-trimoxazole 2/43 (4.65%. Many individual isolates showed resistant against two or more antibiotics in our study. Conclusion: The above study results show that the milk samples collected from local vendor having S. aureus, which can induce disease condition as well as antibiotic resistant to the humans particularly young children and old age peoples by means of consumption of raw milk and its products. This is the public health issue, which needs to be solved by educating the local vendors regarding health problems related to unhygienic milk supply and make the awareness among the consumers about this

Bacteriuria amongst pregnant women in the Buea Health District, Cameroon: prevalence, predictors, antibiotic susceptibility patterns and diagnosis.

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Morike Ngoe Mokube

Full Text Available BACKGROUND: Bacteriuria is associated with significant maternal and foetal risks. However, its prevalence is not known in our community. OBJECTIVES: This study was carried out to determine the prevalence and predictors of bacteriuria in pregnant women of the Buea Health District (BHD as well as the antibiotic sensitivity patterns of bacterial isolates. It also sought to determine the diagnostic performance of the nitrite and leucocyte esterase tests in detecting bacteriuria in these women. METHODS: An observational analytic cross-sectional study was carried out amongst pregnant women attending selected antenatal care centres in Buea. We recruited 102 consenting pregnant women for the study. Demographic and clinical data were collected using structured questionnaires. Clean catch midstream urine was collected from each participant in sterile leak proof containers. Samples were examined biochemically, microscopically and by culture. Significant bacteriuria was defined as the presence of ≥10⁸ bacteria/L of cultured urine. Identification and susceptibility of isolates was performed using API 20E and ATB UR EU (08 (BioMerieux, Marcy l'Etoile, France. RESULTS: Significant bacteriuria was found in the urine of 24 of the 102 women tested giving a bacteriuria prevalence of 23.5% in pregnant women of the BHD. Asymptomatic bacteriuria was detected in 8(7.8% of the women. There was no statistically significant predictor of bacteriuria. Escherichia coli were the most isolated (33% uropathogens and were 100% sensitive to cefixime, cefoxitin and cephalothin. The nitrite and leucocyte esterase tests for determining bacteriuria had sensitivities of 8%, 20.8% and specificities of 98.7% and 80.8% respectively. CONCLUSION: Bacteriuria is frequent in pregnant women in the BHD suggesting the need for routine screening by urine culture. Empiric treatment with cefixime should be instituted until results of urine culture and sensitivity are available. Nitrite and

Genetic characterization of antibiotic resistance in enteropathogenic Escherichia coli carrying extended-spectrum beta-lactamases recovered from diarrhoeic rabbits.

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Poeta, P; Radhouani, H; Gonçalves, A; Figueiredo, N; Carvalho, C; Rodrigues, J; Igrejas, G

2010-05-01

A total of 52 Escherichia coli strains isolated from diarrhoeic rabbits were investigated for their enteropathogenic E. coli (EPEC) pathotype by PCR amplification of eae and bfp virulence genes. A total of 22 EPEC isolates were identified, serotyped and studied for antibiotic resistance and screened for the detection of extended-spectrum beta-lactamases (ESBLs). The EPEC isolates belonged to three serogroups (O26, O92 and O103). The most common serogroup (O103:K-:H2) was observed among 17 EPEC strains, the O92:K-serogroup in three isolates (the antibiotic sensitive ones) and the remaining O26:K-serogroup in two isolates (the ESBLs isolates). Resistances to ampicillin and tetracycline were the most frequent and detected followed by resistance to nalidixic acid, streptomycin, trimethoprim-sulphamethoxazole, cefoxitin, gentamicin and ciprofloxacin. All the isolates were sensitive for amikacin, ceftazidime, aztreonam, imipenem, chloramphenicol, tobramycin and amoxicillin + clavulanic acid. Two isolates recovered from two adult animals showed an intermediate susceptibility to cefotaxime, and a positive screening test for ESBL was demonstrated in both. The bla(TEM) gene was demonstrated in the majority of ampicillin-resistant isolates. The aac(3)-II or aac(3)-IV genes were detected in the four gentamicin-resistant isolates. In addition, the aadA gene was detected in 60% of streptomycin-resistant isolates. The tet(A) or tet(B) genes were identified in all tetracycline-resistant isolates. A total of nine EPEC isolates showed the phenotype SXT-resistant, and the sul1 and/or sul2 and/or sul3 genes were detected in all of them. Our findings showed that the molecular detection by the eae and bfp genes by PCR followed by serotyping is useful for monitoring trends in EPEC infections of rabbits allowing the identification of their possible reservoirs. The detection of genes involved in the resistance to antibiotics of different families in a relatively high proportion of faecal E

Detecção do gene mecA em estafilococos coagulase negativa resistentes à oxacilina isolados da saliva de profissionais da enfermagem Detection of mecA gene in oxacillin-resistant coagulase-negative staphylococci isolated from the saliva of nursing professionals

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Juliana de Oliveira Rosa

2009-08-01

Full Text Available Estafilococos coagulase negativa estão frequentemente associados às infecções nosocomiais e os profissionais da saúde podem ser reservatório e dissemina-los no hospital e comunidade. O objetivo desse estudo foi identificar espécies de estafilococos coagulase negativa isolados da saliva de profissionais da enfermagem, determinar o perfil de resistência e detectar o gene mecA. Foram selecionados 100 estafilococos coagulase negativa, sendo 41 identificados como Staphylococcus epidermidis, 25 Staphylococcus saprophyticus, 18 Staphylococcus haemolyticus, 8 Staphylococcus cohnii, 4 Staphylococcus lugdunenses, 3 Staphylococcus capitis, e 1 Staphylococcus Simulans. Desses, 32% apresentaram resistência à oxacilina, 84,4% à mupirocina, 32% à cefoxitina, e todos sensíveis a vancomicina. Dos estafilococos coagulase negativa resistentes à oxacilina, 93,7% desenvolveram-se no agar oxacilina (6µg/ml e o gene mecA foi detectado em 75%. Os resultados sinalizam que maiores investimentos devem ser direcionados a identificação das espécies de estafilococos coagulase negativa nas instituições de saúde e na comunidade.Coagulase-negative staphylococci are frequently associated with nosocomial infections, and healthcare professionals can be reservoirs and spread them in hospitals and in the community. The aim of this study was to identify species of coagulase-negative staphylococci isolated from the saliva of nursing professionals, determine the resistance profile and detect the mecA gene. One hundred coagulase-negative staphylococci were selected: 41 were identified as Staphylococcus epidermidis, 25 as Staphylococcus saprophyticus, 18 as Staphylococcus haemolyticus, eight as Staphylococcus cohnii, four as Staphylococcus lugdunenses, three as Staphylococcus capitis and one as Staphylococcus simulans. Of these, 32% presented oxacillin resistance, 84.4% mupirocin resistance and 32% cefoxitin resistance, and all were vancomycin sensitive. Among the

High prevalence of methicillin-resistant coagulase-negative staphylococci isolated from a university environment in Thailand.

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Seng, Rathanin; Leungtongkam, Udomluk; Thummeepak, Rapee; Chatdumrong, Wassana; Sitthisak, Sutthirat

2017-06-01

The present study was conducted to isolate and characterize the molecular epidemiology of the methicillin-resistant staphylococci in the general university environment, where all five locations; the library, restrooms, canteens, computer rooms and outdoor surfaces, are in common use by a large population of students. We used Mannitol Salt Agar (MSA) supplemented with 4 μg/ml of oxacillin to screen the methicillin-resistant staphylococci. The species level was identified by PCR of rdr (Staphylococcus epidermidis), groESL (Staphylococcus haemolyticus) and nuc (Staphylococcus aureus and Staphylococcus warneri) genes and DNA sequencing of tuf and dnaJ genes. The susceptibility patterns of the isolates were determined using the disk diffusion method. Antibiotic and disinfectant resistance genes, together with SCCmec types, were detected by the PCR method. The methicillin resistant-staphylococci were isolated from 41 of 200 samples (20.5%), and all of them were found to be methicillin-resistant coagulase negative staphylococci (MR-CoNS). The library had the highest percentage of contamination, with 43.3% of the samples found to be contaminated. All isolates belonged to 6 different species including S. haemolyticus, S. epidermidis, S. warneri, S. cohnii, S. saprophyticus and S. hominis. The antimicrobial resistance rates were highest against penicillin (100%), then cefoxitin (73.1%), erythromycin (73.1%) and oxacillin (68.3%). Altogether, the isolates were approximately 61.0% multidrug resistant (MDR), with the S. epidermidis isolates being the most multidrug resistant. The prevalence of the qacA/B gene was detected in 63.4% of the isolates, and SCCmec could be typed in 43.9% (18/41) of the isolates. The type range was: II (n = 1), IVd (n = 1), I (n = 2), V (n = 6), IVa (n = 8) and untypeable (n = 23). This result indicates that these university environments are contaminated with methicillin-resistant coagulase negative staphylococci that carry various SCCmec types and

Caracterización del gen mecA de Staphylococcus aureus resistentes a meticilina aislados de tres grupos poblacionales de la ciudad de Medellín

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Marcela Sanchez

Full Text Available Introducción: Staphylococcus aureus resistente a la meticilina (SARM es responsable de infecciones intrahospitalarias, las que constituyen una importante causa de morbilidad y mortalidad en nuestro medio, por lo cual la rápida identificación y tipificación molecular de la resistencia como el complejo SSCmec es esencial para entender la epidemiología de la infección. Objetivo: Caracterizar fenotípicamente la resistencia a meticilina y genotípicamente el casete cromosomal SSCmec en cepas de S. aureus aislados de individuos de la ciudad de Medellín mediante PCR múltiple. Materiales y métodos: A 41 aislamientos (hospitalarios y de la comunidad de S. aureus se les estableció la resistencia a cefoxitin mediante la técnica de Kirby-Bauer y la concentración inhibitoria mínima para oxacilina. Mediante PCR convencional se les confirmó la presencia del gen mecA. Para la tipificación del complejo SSCmec se utilizó PCR múltiple para amplificar 6 loci diferentes de este gen. Resultados: A todos los aislamientos se les confirmó resistencia a meticilina y la presencia del gen mecA, de los cuales 17 fueron clasificados como SSC mec I, 1 como SSC mec II, 21 como SSC mecIV; dos aislamientos no fue posible clasificarlos. Conclusiones: Con el uso de esta técnica clasificamos el 95% de los aislamientos del estudio, encontrando una mayor prevalencia de los SSCmec I y IV. La implementación de esta técnica permite una fácil caracterización de los aislamientos SARM y un apropiado manejo de la información de los integrantes de los comités de infecciones hospitalarios, lo cual podría impactar positivamente en el tratamiento a los pacientes y el control de enfermedades infecciosas intrahospitalarias.

Diversity and antibiograms of bacterial organisms isolated from samples of household drinking-water consumed by HIV-positive individuals in rural settings, South Africa.

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Samie, A; Mashao, M B; Bessong, P O; NKgau, T F; Momba, M N B; Obi, C L

2012-09-01

Diarrhoea is a hallmark of HIV infections in developing countries, and many diarrhoea-causing agents are often transmitted through water. The objective of the study was to determine the diversity and antibiotic susceptibility profiles of bacterial organisms isolated from samples of household drinking-water consumed by HIV-infected and AIDS patients. In the present study, household water stored for use by HIV-positive patients was tested for microbial quality, and isolated bacterial organisms were analyzed for their susceptibility profiles against 25 different antibiotics. The microbial quality of water was generally poor, and about 58% of water samples (n=270) were contaminated with faecal coliforms, with counts varying from 2 colony-forming unit (CFU)/100 mL to 2.4x10⁴ CFU/100 mL. Values of total coliform counts ranged from 17 CFU/100 mL to 7.9x10⁵/100 mL. In total, 37 different bacterial species were isolated, and the major isolates included Acinetobacter lwoffii (7.5%), Enterobacter cloacae (7.5%), Shigella spp. (14.2%), Yersinia enterocolitica (6.7%), and Pseudomonas spp. (16.3%). No Vibrio cholerae could be isolated; however, V. fluvialis was isolated from three water samples. The isolated organisms were highly resistant to cefazolin (83.5%), cefoxitin (69.2%), ampicillin (66.4%), and cefuroxime (66.2%). Intermediate resistance was observed against gentamicin (10.6%), cefepime (13.4%), ceftriaxone (27.6%), and cefotaxime (29.9%). Levofloxacin (0.7%), ceftazidime (2.2%), meropenem (3%), and ciprofloxacin (3.7%) were the most active antibiotics against all the microorganisms, with all recording less than 5% resistance. Multiple drug resistance was very common, and 78% of the organisms were resistant to three or more antibiotics. Education on treatment of household water is advised for HIV-positive patients, and measures should be taken to improve point-of-use water treatment as immunosuppressed individuals would be more susceptible to opportunistic

Effectiveness of simple control measures on methicillin-resistant Staphylococcus aureus infection status and characteristics with susceptibility patterns in a teaching hospital in Peshawar.

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Rafiq, Muhammad Salman; Rafiq, Muhammad Imran; Khan, Taimur; Rafiq, Maria; Khan, Mah Muneer

2015-09-01

To determine the effectiveness of simple control measures on the infection status and characteristics of methicillin-resistant Staphylococcus aureus including susceptibility patterns among health professionals and patients in a teaching hospital. The cross-sectional study was conducted from September 2013 to January 2014, and comprised samples collected from healthcare personnel and patients in the various units of Khyber Teaching Hospital, Peshawar. The specimens were collected before and one month after the implementation of simple control measures for outbreak prevention of methicillin-resistant Staphylococcus aureus. These were tested for culture and antimicrobial susceptibility. Data about methicillin-sensitive and methicillin-resistant Staphylococcus aureus infection, wound characteristics and susceptibility patterns was collected and effectiveness of simple control measures was determined. SPSS 20 was used for statistical analysis. Of the total 390 isolates, 180(46.2%) were Staphylococcus aureus; 77(19.7%) from healthcare personnel and 103(26.4%) from patients. Of these, 164(42.1%) were methicillin-sensitive and 16(4.1%) were methicillin-resistant. Among the patients, 38(15.1%) methicillin-sensitive and 8(3.2%) methicillin-resistant isolates were recovered from wounds or skin and soft tissues. Pus with 33(13.1%) and 4(1.6%) cases respectively was the second most common source. Among methicillin-resistant isolates, resistance to Linezolid was 0%, all were resistant to Oxacillin, Cefoxitin, Amoxicillin, Cefotaxime and Cephradine, and resistance to both Co-Amoxiclav and Ciprofloxacin was 87.5%. After one month of implementation of simple control measures, the number of methicillin-resistant cases among healthcare professionals and patients dropped from 4(2.9%) and 7(10.8%) to 1(0.7%) and 5(2.7%), respectively. Methicillin-resistant and methicillin-sensitive Staphylococcus aureus differed in their anti-microbial susceptibility profiles. Selection of antibiotics

Inducible clindamycin and methicillin resistant Staphylococcus aureus in a tertiary care hospital, Kathmandu, Nepal.

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Adhikari, R P; Shrestha, S; Barakoti, A; Amatya, R

2017-07-11

Staphylococcus aureus, an important nosocomial pathogen, is frequently associated with infections in human. The management of the infections by it especially methicillin resistant ones is often difficult because methicillin resistant S. aureus is usually resistant to multiple antibiotics. Macrolide-lincosamide streptogramin B family of antibiotics is commonly used to treat such infections as an alternative to vancomycin. This study was conducted over the period of one and half year from November 2013-April 2015 in Microbiology laboratory of Nepal Medical College and Teaching Hospital, Kathmandu, Nepal to find the incidence of different phenotypes of MLS B resistance among S. aureus from clinical samples and their association with methicillin resistance. Two hundred seventy isolates of S. aureus were included in the study. Methicillin resistance was detected by cefoxitin disc diffusion method and inducible clindamycin resistance by erythromycin and clindamycin disc approximation test (D-test). Of the 270 clinical isolates of S. aureus, 25.1% (68/270) were MRSA. Erythromycin and clindamycin resistance was seen in 54.4% (147/270) and 41.8% (113/270) isolates respectively. Resistance to erythromycin and clindamycin were higher in MRSA as compared to MSSA (erythromycin-resistance: 88.2% Vs 39.1% and clindamycin-resistance: 79.4% Vs 41.8%). The overall prevalence of i MLS B and c MLS B phenotype was 11.48% (31/270) and 29.25% (79/270) respectively. Both i MLS B and c MLS B phenotypes predominated in MRSA strains. Detection rate of MRSA in our study shows the necessity to improve in healthcare practices and to formulate new policy for the control of MRSA infections. Clindamycin resistance in the form of i MLS B and c MLS B especially among MRSA emphasizes the need of D-test to be performed routinely in our set up while using clindamycin as an alternative choice to anti-staphylococcal antibiotics like vancomycin and linezolid in the treatment of staphylococcal infections.

MARCADORES DE PATOGENICIDADE EM Yersinia enterocolitica O: 3 ISOLADAS DE SUÍNOS DO RIO DE JANEIRO Genetic markers of pathogenicity in Yersinia enterocolitica O: 3 isolated from healthy pigs from Rio de Janeiro

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Tereza C. A. Leal

1997-01-01

Full Text Available Foi realizada a caracterização genotípica e fenotípica de fatores de patogenicidade em 16 amostras de Yersinia enterocolitica O:3 isoladas de suínos sadios do Rio de Janeiro. Foi observado que apenas 6 cepas possuíam o plasmídio de virulência, pYV (+ 70 kb e apresentavam dependência ao cálcio no meio MOX a 37C. Um plasmídio críptico de cerca de 8,6 kb foi encontrado em uma cepa. Doze cepas revelaram sensibilidade à pesticina enquanto que apenas três se revelaram capazes de hidrolisar a esculina. Através de PCR com "primers" específicos, foi constatada a presença dos genes ail em 14 cepas, irp2, em 1 cepa e a ausência de psaA em todas as cepas analisadas. Quanto aos quimioterápicos, a quase totalidade das cepas mostrou-se ao mesmo tempo resistente à ampicilina e carbenicilina e sensível ao sulfazotrin e à cefoxitina. As respostas foram variadas frente ao cloranfenicol, tetraciclina, kanamicina, gentamicina e ácido nalidíxo.Sixteen Yersinia enterocolitica serotype O:3 strains, isolated from pigs from Rio de Janeiro, have been analyzed for genetic and phenotypic markers of pathogenicity. It was observed that only 6 strains harbored the pYV (+70 kb plasmid and one strain harbored a small cryptic plasmid of about 8.6 kb. Accordingly only strains harboring pYV were calcium dependent in the MOX medium at 370C. Twelve strains showed pesticin sensitivity and the esculin reaction was negative in 13 strains. PCR analysis of pathogenicity genes using specific primers showed the presence of the ail gene in 14 strains, the irp2 gene in one and the psaA in none. Most of the strains were resistant to ampicillin and carbenicillin, although they were susceptible to sulfazotrin and cefoxitin. For chloramphenicol, tetracycline, kanamycin, gentamicin and nalidixic acid the results varied among the strains.

Bacteriology and Antibiogram of Urinary Tract Infection Among Female Patients in a Tertiary Health Facility in South Eastern Nigeria.

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Oli, Angus N; Akabueze, Vivian B; Ezeudu, Chijioke E; Eleje, George U; Ejiofor, Obiora S; Ezebialu, Ifeanyichukwu U; Oguejiofor, Charlotte B; Ekejindu, Ifeoma M; Emechebe, George O; Okeke, Kenneth N

2017-01-01

Urinary Tract Infection (UTI) is a common contagion among men and women with the incidence relatively higher among women due to their differing anatomy. An understanding of the kind of pathogens implicated in urinary tract infections as well as antibiotic susceptibility profiling may help the clinician make rationally correct empirical choice in their treatment. This study is aimed at determining the type and antibiotic susceptibility pattern of bacterial uropathogens isolated from female patients attending Chukwuemeka Odumegwu Ojukwu University Teaching Hospital (COOUTH), Awka, Nigeria. Two hundred and forty patients with clinically diagnosed UTI and who were on at least 5 days' antibiotic holiday were recruited into the study. Their demographic characteristics were captured using pre-tested questionnaire. Their clean catch mid-stream urine samples were collected using sterile universal container and sent to the Microbiology Department for processing. Within 30 minutes of samples collection, the specimens were cultured and the isolates were identified, after 24 h of incubation, using standard microbiological techniques. Antibiotic susceptibility tests were done with standard antibiotic discs using the Kirby-bauer disc diffusion method. Out of the 240 urine samples, 89.17% yielded significant bacteriuria. The pathogens implicated were Escherichia coli (28.5%), Staphylococcus aureus (28.0%), Salmonella spp (22.8%) and Pseudomonas aeruginosa (20.5%). HIV status, patients age, pregnancy status and marital status all significantly affected bacteriuria rate (p value 0.05). The pattern of microbial resistance to antibiotics suggests that ceftazidime, fosfomycin and cefoxitin may not be used as first-line agents in the empirical treatment of UTIs rather; levofloxacin, meropenem or aztreonam should be considered. Levofloxacin was significantly effective against all the isolates and may be administered empirically while waiting for the culture result (Mean % susceptibility

Tigecycline Susceptibility Trends Among Pathogens Isolated from Complicated Skin and Soft-Tissue Infections in North and Latin America: 2012–2016

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Hoban, Daryl; Renteria, Martha; Leister-Tebbe, Heidi; Sahm, Dan

2017-01-01

Abstract Background The Tigecycline Evaluation Surveillance Trial (TEST) monitors the activity of tigecycline and other antimicrobials against clinically-relevant pathogens collected globally. This study reports the activity of tigecycline (TGC) against Gram-positive and Gram-negative isolates collected in North and Latin America from patients with complicated skin and soft-tissue infections (CSSTI). Methods Hospital sites from North America (NA) and Latin America (LA) collected non-duplicate clinical Gram-positive and -negative isolates from various complicated skin and skin structure infection sources during 2012–2016. Organism identification and antibiotic susceptibility (S) testing was performed by the local laboratories. Susceptibility testing was determined using the broth microdilution method according to CLSI guidelines and categorical interpretation of results was done using CLSI or FDA (tigecycline) breakpoint criteria where appropriate. Cefoxitin disk testing was performed for all S. aureus to determine methicillin susceptibility (i.e., MRSA and MSSA). Results The table provides %S and MIC90 data for TGC against CSSTI isolates Region, n, %S, MIC 90 (µg/ml) North America Latin America Organism n %S MIC 90 n %S MIC 90 S. aureus 2270 100 0.12 310 100 0.25 Enterobacter spp. 925 96.4 1 159 92.5 2 P. aeruginosa 758 na* > 8 165 na > 8 E. coli 716 99.9 0.25 241 100 0.25 Enterococcus spp. 691 99.3 0.12 135 100 0.12 S. agalactiae 503 100 0.12 58 100 0.06 K. pneumoniae 471 94.9 2 152 91.5 2 S. marcescens 347 96.8 2 67 97.0 2 A. baumannii 310 na* 2 97 na 1 K. oxytoca 204 99.0 0.5 15 100 1 *na = not applicable or no breakpoints available for this species. Conclusion Based on %S and MIC90 data TGC exhibited potent activity against isolates of all organism groups from complicated skin and soft-tissue infections, regardless of the geographic region. However, given the potential many of these organisms have for developing resistance, continued and careful

The carriage of antibiotic resistance by enteric bacteria from imported tokay geckos (Gekko gecko) destined for the pet trade

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Casey, Christine L. [Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States); Hernandez, Sonia M., E-mail: shernz@uga.edu [Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States); Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602 (United States); Yabsley, Michael J. [Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States); Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602 (United States); Smith, Katherine F. [Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912 (United States); Sanchez, Susan [The Athens Veterinary Diagnostic Laboratory, Athens, GA 30602 (United States); The Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States)

2015-02-01

The emergence of antibiotic-resistant bacteria is a growing public health concern and has serious implications for both human and veterinary medicine. The nature of the global economy encourages the movement of humans, livestock, produce, and wildlife, as well as their potentially antibiotic-resistant bacteria, across international borders. Humans and livestock can be reservoirs for antibiotic-resistant bacteria; however, little is known about the prevalence of antibiotic-resistant bacteria harbored by wildlife and, to our knowledge, limited data has been reported for wild-caught reptiles that were specifically collected for the pet trade. In the current study, we examined the antibiotic resistance of lactose-positive Enterobacteriaceae isolates from wild-caught Tokay geckos (Gekko gecko) imported from Indonesia for use in the pet trade. In addition, we proposed that the conditions under which wild animals are captured, transported, and handled might affect the shedding or fecal prevalence of antibiotic resistance. In particular we were interested in the effects of density; to address this, we experimentally modified densities of geckos after import and documented changes in antibiotic resistance patterns. The commensal enteric bacteria from Tokay geckos (G. gecko) imported for the pet trade displayed resistance against some antibiotics including: ampicillin, amoxicillin/clavulanic acid, cefoxitin, chloramphenicol, kanamycin and tetracycline. There was no significant difference in the prevalence of antibiotic-resistant bacteria after experimentally mimicking potentially stressful transportation conditions reptiles experience prior to purchase. There were, however, some interesting trends observed when comparing Tokay geckos housed individually and those housed in groups. Understanding the prevalence of antibiotic resistant commensal enteric flora from common pet reptiles is paramount because of the potential for humans exposed to these animals to acquire antibiotic

Assessment of Staphylococcus aureus along milk value chain and its public health importance in Sebeta, central Oromia, Ethiopia.

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Ayele, Yodit; Gutema, Fanta Desissa; Edao, Bedaso Mamo; Girma, Robel; Tufa, Takele Beyene; Beyene, Tariku Jibat; Tadesse, Fanos; Geloye, Mesula; Beyi, Ashenafi Feyisa

2017-06-27

Staphylococcus aureus is one of the leading causes of gastroenteritis acquired from contaminated foods such as milk and milk products. However, such information is limited in Ethiopia. A cross-sectional study was conducted to assess the contamination of milk with S. aureus and knowledge, attitudes and practices (KAP) of actors along the milk value chain in Sebeta, Central Oromia, Ethiopia. A total of 291 samples collected from dairy farms, milk collection centers (MCCs) and processing plant were examined using standard microbiological techniques. The antimicrobial susceptibility profiles of the isolates were also investigated. The KAP of actors in milk value chain were evaluated through a structured questionnaire. Overall, 23.4% (n = 68) of the samples were positive for S. aureus. The prevalence of S. aureus was 19.6% (95% CI: 14.5-25.6) and 80.0% (95% CI: 14.5-25.6) at farm level and MCCs, respectively. Higher isolation rate was observed in the MCCs (p = 0.000) than the farms. The contamination rates of hands of milkers' and milking buckets with S. aureus were 32% and 11.1%, respectively. S. aureus was not isolated from pasteurized milk samples. The isolates were found to be resistant to cefoxitin (100%), penicillin G (98.5%), and streptomycin (77.9%). Among 23 interviewed farmers, 35% of them consumed raw milk, none of them wash their hands and 82.6% did not wash udder and teat before milking. Six percent of consumers had the habit of raw milk consumption. Eighty seven percent of dairy farmers and 54% of consumers had no awareness about milk borne diseases and staphylococcal food poisoning. The study revealed a high prevalence of S. aureus along the milk value chain, poor milk handling practices, raw milk consumption behavior, lack of awareness about milk borne diseases and occurrence of antimicrobials resistant S. aureus. S. aureus seems to pose a public health risk in Sebeta. Authors recommended the urgent need of public awareness creation about the

Mycobacterium icosiumassiliensis sp. nov., a New Member in the Mycobacterium terrae Complex Isolated from Surface Water in Algeria.

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Djouadi, Lydia N; Levasseur, Anthony; Khalil, Jacques Bou; Blanc-Taileur, Caroline; Asmar, Shady; Ghiloubi, Wassila; Natèche, Farida; Drancourt, Michel

2016-08-01

An acid-fast, rapidly growing, rod-shaped microorganism designated 8WA6 was isolated from a lake in Algiers, Algeria. The lake water was characterized by a temperature of 18 °C, a pH of 7.82, a copper concentration of 8.6 µg/L, and a cadmium concentration of 0.6 µg/L. First-line molecular identification confirmed the 8WA6 isolate to be a member of the Mycobacterium terrae complex, sharing 99.4 % 16S rRNA gene sequence similarity with M. arupense AR-30097, 98.2 % partial hsp65 gene sequence similarity with M. terrae 28K766, and 97.1 % partial rpoB gene sequence similarity with Mycobacterium sp. FI-05396. Its 4.89-Mb genome exhibits a 66.8 GC % and an average nucleotide identity of 64.5 % with M. tuberculosis, 70.5 % with M. arupense, and 75 % with M. asiaticum. In the M. terrae complex, Mycobacterium 8WA6 was unique in exhibiting growth at 42 °C, negative reaction for nitrate reduction, urease activity and Tween 80 hydrolysis, and a positive reaction for α-glucosidase and β-glucosidase. Its protein profile determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry revealed a unique spectrum similar to M. arupense and M. terrae, exhibiting eleven specific peaks at 3787.791, 4578.019, 6349.630, 6855.638, 7202.310, 8149.608, 8775.257, 10,224.588, 10,484.116, 12,226.379, and 12,636.871 m/z. Minimal inhibitory concentrations (MIC) for antibiotics, determined by microdilution, indicated a broad spectrum resistance, except for rifabutin (MIC, 0.5 g/L) and cefoxitin (MIC, 16 g/L). We concluded that the 8WA6 isolate is a representative isolate of a previously undescribed species in the M. terrae complex, which was named M. icosiumassiliensis sp. nov. with strain 8WA6 (Collection de Souches de l'Unité des Rickettsies, CSUR P1561, Deutsche Sammlung von Mikroorganismen und Zellkulturen, DSM 100711) as the type strain.

The carriage of antibiotic resistance by enteric bacteria from imported tokay geckos (Gekko gecko) destined for the pet trade

International Nuclear Information System (INIS)

Casey, Christine L.; Hernandez, Sonia M.; Yabsley, Michael J.; Smith, Katherine F.; Sanchez, Susan

2015-01-01

The emergence of antibiotic-resistant bacteria is a growing public health concern and has serious implications for both human and veterinary medicine. The nature of the global economy encourages the movement of humans, livestock, produce, and wildlife, as well as their potentially antibiotic-resistant bacteria, across international borders. Humans and livestock can be reservoirs for antibiotic-resistant bacteria; however, little is known about the prevalence of antibiotic-resistant bacteria harbored by wildlife and, to our knowledge, limited data has been reported for wild-caught reptiles that were specifically collected for the pet trade. In the current study, we examined the antibiotic resistance of lactose-positive Enterobacteriaceae isolates from wild-caught Tokay geckos (Gekko gecko) imported from Indonesia for use in the pet trade. In addition, we proposed that the conditions under which wild animals are captured, transported, and handled might affect the shedding or fecal prevalence of antibiotic resistance. In particular we were interested in the effects of density; to address this, we experimentally modified densities of geckos after import and documented changes in antibiotic resistance patterns. The commensal enteric bacteria from Tokay geckos (G. gecko) imported for the pet trade displayed resistance against some antibiotics including: ampicillin, amoxicillin/clavulanic acid, cefoxitin, chloramphenicol, kanamycin and tetracycline. There was no significant difference in the prevalence of antibiotic-resistant bacteria after experimentally mimicking potentially stressful transportation conditions reptiles experience prior to purchase. There were, however, some interesting trends observed when comparing Tokay geckos housed individually and those housed in groups. Understanding the prevalence of antibiotic resistant commensal enteric flora from common pet reptiles is paramount because of the potential for humans exposed to these animals to acquire antibiotic

Phenotype, genotype, and antibiotic susceptibility of Swedish and Thai oral isolates of Staphylococcus aureus

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Susanne Blomqvist

2015-04-01

Full Text Available Objective: The present study investigated phenotypes, virulence genotypes, and antibiotic susceptibility of oral Staphylococcus aureus strains in order to get more information on whether oral infections with this bacterium are associated with certain subtypes or related to an over-growth of the S. aureus variants normally found in the oral cavity of healthy carriers. Materials and methods: A total number of 157 S. aureus strains were investigated. Sixty-two strains were isolated from Swedish adults with oral infections, 25 strains were from saliva of healthy Swedish dental students, and 45 strains were from tongue scrapings of HIV-positive subjects in Thailand, and 25 Thai strains from non-HIV controls. The isolates were tested for coagulase, nitrate, arginine, and hemolysin, and for the presence of the virulence genes: hlg, clfA, can, sdrC, sdrD, sdrE, map/eap (adhesins and sea, seb, sec, tst, eta, etb, pvl (toxins. MIC90 and MIC50 were determined by E-test against penicillin V, oxacillin, amoxicillin, clindamycin, vancomycin, fusidic acid, and cefoxitin. Results: While the hemolytic phenotype was significantly (p<0.001 more common among the Thai strains compared to Swedish strains, the virulence genes were found in a similar frequency in the S. aureus strains isolated from all four subject groups. The Panton-Valentine leukocidin (PVL genotype was found in 73–100% of the strains. More than 10% of the strains from Swedish oral infections and from Thai HIV-positives showed low antibiotic susceptibility, most commonly for clindamycin. Only three methicillin-resistant S. aureus (MRSA strains were identified, two from oral infections and one from a Thai HIV patient. Conclusions: S. aureus is occasionally occurring in the oral cavity in both health and disease in Sweden and Thailand. It is therefore most likely that S. aureus in opportunistic oral infections originate from the oral microbiota. S. aureus should be considered in case of oral

Patterns of infections, aetiological agents and antimicrobial resistance at a tertiary care hospital in northern Tanzania.

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Kumburu, Happiness Houka; Sonda, Tolbert; Mmbaga, Blandina Theophil; Alifrangis, Michael; Lund, Ole; Kibiki, Gibson; Aarestrup, Frank M

2017-04-01

To determine the causative agents of infections and their antimicrobial susceptibility at a tertiary care hospital in Moshi, Tanzania, to guide optimal treatment. A total of 590 specimens (stool (56), sputum (122), blood (126) and wound swabs (286)) were collected from 575 patients admitted in the medical and surgical departments. The bacterial species were determined by conventional methods, and disc diffusion was used to determine the antimicrobial susceptibility pattern of the bacterial isolates. A total of 249 (42.2%) specimens were culture-positive yielding a total of 377 isolates. A wide range of bacteria was isolated, the most predominant being Gram-negative bacteria: Proteus spp. (n = 48, 12.7%), Escherichia coli (n = 44, 11.7%), Pseudomonas spp. (n = 40, 10.6%) and Klebsiella spp (n = 38, 10.1%). Wound infections were characterised by multiple isolates (n = 293, 77.7%), with the most frequent being Proteus spp. (n = 44, 15%), Pseudomonas (n = 37, 12.6%), Staphylococcus (n = 29, 9.9%) and Klebsiella spp. (n = 28, 9.6%). All Staphylococcus aureus tested were resistant to penicillin (n = 22, 100%) and susceptible to vancomycin. Significant resistance to cephalosporins such as cefazolin (n = 62, 72.9%), ceftriaxone (n = 44, 51.8%) and ceftazidime (n = 40, 37.4%) was observed in Gram-negative bacteria, as well as resistance to cefoxitin (n = 6, 27.3%) in S. aureus. The study has revealed a wide range of causative agents, with an alarming rate of resistance to the commonly used antimicrobial agents. Furthermore, the bacterial spectrum differs from those often observed in high-income countries. This highlights the imperative of regular generation of data on aetiological agents and their antimicrobial susceptibility patterns especially in infectious disease endemic settings. The key steps would be to ensure the diagnostic capacity at a sufficient number of sites and implement structures to routinely exchange, compare, analyse and report data. Sentinel sites

Prevalence and clonal relationship of ESBL-producing Salmonella strains from humans and poultry in northeastern Algeria.

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Djeffal, Samia; Bakour, Sofiane; Mamache, Bakir; Elgroud, Rachid; Agabou, Amir; Chabou, Selma; Hireche, Sana; Bouaziz, Omar; Rahal, Kheira; Rolain, Jean-Marc

2017-05-15

The aims of this study were to investigate Salmonella contamination in broiler chicken farms and slaughterhouses, to assess the antibiotic resistance profile in avian and human Salmonella isolates, and to evaluate the relationship between avian and human Extended Spectrum β-Lactamase (ESBL)-producing isolates. Salmonella was screened in different sample matrices collected at thirty-two chicken farms and five slaughterhouses. The human isolates were recovered from clinical specimens at the University Teaching Hospital of Constantine (UTH). All suspected colonies were confirmed by MALDI-TOF (Matrix Assisted Laser Desorption Ionization Time OF light) and serotyped. Susceptibility testing against 13 antibiotics including, amoxicillin/clavulanic acid, ticarcillin, cefoxitin, cefotaxime, aztreonam, imipenem, ertapenem, gentamicin, amikacin, ciprofloxacin, colistin, trimethoprim/sulfamethoxazole and fosfomycin, was performed using the disk diffusion method on Mueller-Hinton agar. ESBL-production was screened by the double-disk synergy test and confirmed by molecular characterization using PCR (polymerase chain reaction) amplification and sequencing of ESBL encoding genes. Clonality of the avian and human strains was performed using the Multi Locus Sequencing Typing method (MLST). Forty-five isolated avian Salmonella strains and 37 human collected ones were studied. Five S. enterica serotypes were found in avian isolates (mainly Kentucky) and 9 from human ones (essentially Infantis). 51.11% and 26.6% of the avian isolates were resistant to ciprofloxacin and cefotaxime, respectively, whereas human isolates were less resistant to these antibiotics (13.5% to ciprofloxacin and 16.2% to cefotaxime). Eighteen (12 avian and 6 human) strains were found to produce ESBLs, which were identified as bla CTX-M-1 (n = 12), bla CTX-M-15 (n = 5) and bla TEM group (n = 8). Interestingly, seven of the ESBL-producing strains (5 avian and 2 human) were of the same ST (ST15) and

Characterization of methicillin-resistant Staphylococcus aureus isolated from healthy turkeys and broilers using DNA microarrays

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Hosny El-Adawy

2016-12-01

Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is a major human health problem and recently, domestic animals, in particular pigs and poultry are discussed as carriers and possible reservoirs of MRSA. Twenty seven S. aureus isolates from five turkey farms (n=18 and two broiler farms (n=9 were obtained by culturing of choana and skin swabs from apparently healthy birds, identified by Taqman-based real-time duplex nuc-mecA-PCR and characterized by spa typing as well as by a DNA microarray based assay which covered, amongst others, a considerable number of antibiotic resistance genes, species controls and virulence markers. The antimicrobial susceptibility profiles were tested by agar diffusion assays and genotypically confirmed by the microarray. Five different spa types (3 in turkeys and 2 in broilers were detected. The majority of MRSA isolates (24/27 belonged to clonal complex 398-MRSA-V. The most frequently occurring spa types were accordingly t011, t034 and t899. A single CC5-MRSA-III isolated from turkey and CC398-MRSA with an unidentified/truncated SCCmec element in turkey and broiler were additionally detected. The phenotypic antimicrobial resistance profiles of S. aureus isolated from both turkeys and broilers against 14 different antimicrobials showed that all isolates were resistant to ampicillin, cefoxitin, oxacillin, doxycycline and tetracycline. Moreover, all S. aureus isolated from broilers were resistant to erythromycin and azithromycin. All isolates were susceptible to gentamicin, chloramphenicol, sulphonamides and fusidic acid. The resistance rate against ciprofloxacin was 55.6% in broiler isolates and 42.1% in turkey isolates. All tetracycline resistant isolates possessed genes tetK/M. All erythromycin-resistant broiler isolates carried ermA. Only one broiler isolate (11.1% carried genes ermA, ermB and ermC, while 55.6% of turkey isolates possessed ermA and ermB genes.Neither PVL genes (lukF/S-PV, animal-associated leukocidin

Update of incidence and antimicrobial susceptibility trends of Escherichia coli and Klebsiella pneumoniae isolates from Chinese intra-abdominal infection patients.

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Zhang, Hui; Yang, Qiwen; Liao, Kang; Ni, Yuxing; Yu, Yunsong; Hu, Bijie; Sun, Ziyong; Huang, Wenxiang; Wang, Yong; Wu, Anhua; Feng, Xianju; Luo, Yanping; Chu, Yunzhuo; Chen, Shulan; Cao, Bin; Su, Jianrong; Duan, Qiong; Zhang, Shufang; Shao, Haifeng; Kong, Haishen; Gui, Bingdong; Hu, Zhidong; Badal, Robert; Xu, Yingchun

2017-12-18

. Susceptibilities to all cephalosporins and fluoroquinolones were less than 50% beside 66.5% and 56.07% to cefoxitin (FOX) for ESBL+ Escherichia coli and Klebsiella pneumoniae strains respectively. The total ESBL+ rates decreased in Escherichia coli and Klebsiella pneumoniae IAI isolates due to fewer prevalence in HA infections. IPM, ETP and AMK were the most effective antimicrobials against ESBL+ Escherichia coli and Klebsiella pneumoniae IAI isolates in 2012-2014 and a change of fluoroquinolone regimens for Chinese IAIs is recommended.

Microbiological quality and antimicrobial resistance characterization of Salmonella spp. in fresh milk value chains in Ghana.

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Parry-Hanson Kunadu, Angela; Holmes, Mark; Miller, Eric L; Grant, Andrew J

2018-07-20

Consumer perception of poor hygiene of fresh milk products is a major barrier to promotion of milk consumption as an intervention to alleviate the burden of malnutrition in Ghana. Fresh milk is retailed raw, boiled, or processed into unfermented cheese and spontaneously fermented products in unlicensed outlets. In this study, we have determined microbiological quality of informally retailed fresh milk products and characterized the genomic diversity and antimicrobial resistance (AMR) patterns of non-typhoidal Salmonella (NTS) in implicated products. A total of 159 common dairy products were purchased from five traditional milk markets in Accra. Samples were analysed for concentrations of aerobic bacteria, total and fecal coliforms, Escherichia coli, staphylococci, lactic acid bacteria and yeast and moulds. The presence of Salmonella, E. coli O157:H7, Listeria monocytogenes and Staphylococcus aureus were determined. AMR of Salmonella against 18 antibiotics was experimentally determined. Genome sequencing of 19 Salmonella isolates allowed determination of serovars, antigenic profiles, prediction of AMR genes in silico and inference of phylogenetic relatedness between strains. Raw and heat-treated milk did not differ significantly in overall bacterial quality (P = 0.851). E. coli O157:H7 and Staphylococcus aureus were present in 34.3% and 12.9% of dairy products respectively. Multidrug resistant (MDR) Salmonella enterica serovars Muenster and Legon were identified in 11.8% and 5.9% of unfermented cheese samples respectively. Pan genome analysis revealed a total of 3712 core genes. All Salmonella strains were resistant to Trimethoprim/Sulfamethoxazole, Cefoxitin, Cefuroxime Axetil and Cefuroxime. Resistance to Chloramphenicol (18%) and Ciprofloxacin (100%), which are first line antibiotics used in treatment of NTS bacteremia in Ghana, was evident. AMR was attributed to presence and/or mutations in the following genes: golS, sdiA for cephalosporins, aac(6')-Iy, ant

Identification of Variable Traits among the Methicillin Resistant and Sensitive Coagulase Negative Staphylococci in Milk Samples from Mastitic Cows in India

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Sudipta Mahato

2017-07-01

Full Text Available Methicillin resistant Staphylococcus aureus causing bovine mastitis has been very well investigated worldwide. However, there are only limited reports on the characterization of methicillin resistant and sensitive coagulase negative staphylococci (CoNS across the globe. Hence, in the present study, we aim to determine the phenotypic traits based on antimicrobial susceptibility profile and genotypic characterization by verifying the presence of resistance determinants, virulence and toxin genes present in the CoNS causing clinical mastitis. We obtained 62 CoNS isolates from 167 mastitic milk samples collected from three different states of India. The 62 isolates comprises of 10 different CoNS species S. sciuri, S. haemolyticus, S. chromogenes, S. saprophyticus, S. xylosus, S. simulans, S. agnetis, S. epidermidis, S. gallinarum, and S. cohinii. Susceptibility screening against 11 antibiotics determined 45.16% isolates as multidrug resistant (resistant to more than two class of antibiotic, 46.74% resistant (one or two antibiotic class and 8.06% isolates were pan-sensitive (sensitive to all drugs. High resistance was observed against oxacillin and cefoxitin, whereas all isolates were susceptible toward vancomycin and linezolid. Fifty three isolates were methicillin resistant and 9 isolates were sensitive as determined by oxacillin susceptibility assay. The methicillin resistance gene, mecA was found in 95.16% isolates and staphylococcal cassette chromosome mec (SCCmec typing predominantly revealed Type III (n = 34 and Type V (n = 18. Interestingly, 11.9% of mecA positive isolates were oxacillin susceptible and referred as oxacillin susceptible mecA positive staphylococci (OS-MRS. Additionally, genes encoding for enterotoxin, (sea, seb, seh, see toxic shock syndrome (tsst, exfoliatin (eta, etb, etd and virulence (pvl, Y-hlg were also screened. Of all the genes examined, 67.74% of isolate were positive for the Y-hlg gene, followed by the sea gene in

Bacteriologic Profile and Antibiogram of Blood Culture Isolates from a Children's Hospital in Kabul

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Tariq, O. M.

2014-01-01

Objective: To identify the bacterial pathogens causing paediatric septicaemia in Kabul and to determine their antibiogram to improve empirical antibiotic therapy. Study Design: Cross-sectional study. Place and Duration of Study: Microbiology Laboratory of FMIC, Kabul, Afghanistan, from January 2010 to June 2012. Methodology: Blood cultures from suspected cases of sepsis were processed in BD (Becton Dickinson, USA) for culture BACTEC 9240 Blood Culture System. Positive growths were examined and isolates were identified by conventional biochemical tests. Bacteria were identified to the species level using various Analytical Profile Index (API) identification strips. Antibiotic susceptibility testing was performed by modified Kirby-Bauer disk diffusion method. Drug resistant strains were studied for extended spectrum beta lactamase (ESBL) production by combination disk method and for methicillin resistant Staphylococcus aureus (MRSA) by Cefoxitin disk diffusion method. Results: Out of a total 3360 blood cultures received from in-patients, 410 yielded monomicrobial growth; hence the frequency of positive blood culture was 12.2%. Out of a total 410 isolates, 212 (51.71%) were gram-negative bacilli and 184 (44.88%) were gram-positive cocci. In addition, 14 (3.41%) Candida species were also isolated. The frequently isolated species of gram-negative bacteria belonged to Enterobacteriaceae and included 66 Klebsiella (16.1%), 42 Enterobacter (10.2%), 35 Escherichia (E.) coli (8.5%) and 16 Serratia (3.9%) species. In addition, 21 (5.12%) Pseudomonas species were also isolated. Correspondingly, amongst gram-positive cocci, the most frequently isolated species were 108 coagulase-negative Staphylococci (26.34%) followed by 49 Staphylococcus aureus (11.95%) and 21 Streptococcus species (5.12%). Among gram-negative isolates, those that produced ESBL i.e., 110 out of 212 (51.9%) were found to be multidrug-resistant and showed high resistance to commonly used antibiotics namely

Bacteriologic profile and antibiogram of blood culture isolates from a children's hospital in Kabul.

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Tariq, Tariq Mahmud

2014-06-01

To identify the bacterial pathogens causing paediatric septicaemia in Kabul and to determine their antibiogram to improve empirical antibiotic therapy. Cross-sectional study. Microbiology Laboratory of FMIC, Kabul, Afghanistan, from January 2010 to June 2012. Blood cultures from suspected cases of sepsis were processed in BD (Becton Dickinson, USA) for culture BACTEC™ 9240 Blood Culture System. Positive growths were examined and isolates were identified by conventional biochemical tests. Bacteria were identified to the species level using various Analytical Profile Index (API) identification strips. Antibiotic susceptibility testing was performed by modified Kirby-Bauer disk diffusion method. Drug resistant strains were studied for extended spectrum beta lactamase (ESBL) production by combination disk method and for methicillin resistant Staphylococcus aureus (MRSA) by Cefoxitin disk diffusion method. Out of a total 3360 blood cultures received from in-patients, 410 yielded monomicrobial growth; hence the frequency of positive blood culture was 12.2%. Out of a total 410 isolates, 212 (51.71%) were gram-negative bacilli and 184 (44.88%) were gram-positive cocci. In addition, 14 (3.41%) Candida species were also isolated. The frequently isolated species of gram-negative bacteria belonged to Enterobacteriaceae and included 66 Klebsiella (16.1%), 42 Enterobacter (10.2%), 35 Escherichia (E.) coli (8.5%) and 16 Serratia (3.9%) species. In addition, 21 (5.12%) Pseudomonas species were also isolated. Correspondingly, amongst gram-positive cocci, the most frequently isolated species were 108 coagulase-negative Staphylococci (26.34%) followed by 49 Staphylococcus aureus (11.95%) and 21 Streptococcus species (5.12%). Among gram-negative isolates, those that produced ESBL i.e., 110 out of 212 (51.9%) were found to be multidrug-resistant and showed high resistance to commonly used antibiotics namely Ampicillin, Gentamicin, 3rd generation Cephalosporins, Fluoroquinolones and

Prevalence of antimicrobial resistance in fecal Escherichia coli and Salmonella enterica in Canadian commercial meat, companion, laboratory, and shelter rabbits (Oryctolagus cuniculus) and its association with routine antimicrobial use in commercial meat rabbits.

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Kylie, Jennifer; McEwen, Scott A; Boerlin, Patrick; Reid-Smith, Richard J; Weese, J Scott; Turner, Patricia V

2017-11-01

Antimicrobial resistance (AMR) in zoonotic (e.g. Salmonella spp.), pathogenic, and opportunistic (e.g. E. coli) bacteria in animals represents a potential reservoir of antimicrobial resistant bacteria and resistance genes to bacteria infecting humans and other animals. This study evaluated the prevalence of E. coli and Salmonella enterica, and the presence of associated AMR in commercial meat, companion, research, and shelter rabbits in Canada. Associations between antimicrobial usage and prevalence of AMR in bacterial isolates were also examined in commercial meat rabbits. Culture and susceptibility testing was conducted on pooled fecal samples from weanling and adult commercial meat rabbits taken during both summer and winter months (n=100, 27 farms), and from pooled laboratory (n=14, 8 laboratory facilities), companion (n=53), and shelter (n=15, 4 shelters) rabbit fecal samples. At the facility level, E. coli was identified in samples from each commercial rabbit farm, laboratory facility, and 3 of 4 shelters, and in 6 of 53 companion rabbit fecal samples. Seventy-nine of 314 (25.2%; CI: 20.7-30.2%) E. coli isolates demonstrated resistance to >1 antimicrobial agent. At least one E. coli isolate resistant to at least one antimicrobial agent was present in samples from 55.6% of commercial farms, and from 25% of each laboratory and shelter facilities, with resistance to tetracycline being most common; no resistance was identified in companion animal samples. Salmonella enterica subsp. was identified exclusively in pooled fecal samples from commercial rabbit farms; Salmonella enterica serovar London from one farm and Salmonella enterica serovar Kentucky from another. The S. Kentucky isolate was resistant to amoxicillin/clavulanic acid, ampicillin, cefoxitin, ceftiofur, ceftriaxone, streptomycin, and tetracycline, whereas the S. London isolate was pansusceptible. Routine use of antimicrobials on commercial meat rabbit farms was not significantly associated with the

Occurrence of Extended Spectrum β-Lactamases, KPC-Type, and MCR-1.2-Producing Enterobacteriaceae from Wells, River Water, and Wastewater Treatment Plants in Oltrepò Pavese Area, Northern Italy

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Mariasofia Caltagirone

2017-11-01

Full Text Available To evaluate the water compartment antibiotic-resistance contamination rates, 11 wells, five streams, and four treatment plants located in the Oltrepò Pavese area were screened for the presence of third generation cephalosporins resistant Gram-negative bacteria. Enterobacteriaceae were also characterized for the Extended-Spectrum-β-Lactamases (ESBLs, carbapenemases, and mcr-1 genes presence. From December 2014 to November 2015, 246 water samples were filtered, plated on Plate Count Agar, MacConkey Agar, and MacConkey Agar with cefotaxime. Isolates were species identified using AutoSCAN-4-System and ESBLs, carbapenemases, and colistin resistance determinants were characterized by PCR, sequencing, and microarray. Plasmid conjugative transfer experiments, PCR-based Replicon typing, Pulsed-Field Gel Electrophoresis, Multi-Locus-Sequence-Typing, and in-silico plasmid characterization were performed. A total of 132 enterobacteria isolates grew on MacConkey agar with cefotaxime: 82 (62.1% were obtained from streams, 41 (31.1% from treatment plants, and 9 (6.8% from wells. Thirty out of 132 (22.7% isolates, mainly belonging to Escherichia coli (n = 15 species, showed a synergic effect with piperacillin-tazobactam. A single ESBL gene of blaCTX−M-type was identified in 19/30 isolates. In further two E. coli strains, a blaCTX−M−1 gene co-existed with a blaSHV-type ESBL determinant. A blaSHV−12 gene was detected in two isolates of E. coli (n = 1 and Klebsiella oxytoca (n = 1, while any ESBL determinant was ascertained in seven Yersinia enterocolitica strains. A blaDHA-type gene was detected in a cefoxitin resistant Y. enterocolitica from a stream. Interestingly, two Klebsiella pneumoniae strains of ST307 and ST258, collected from a well and a wastewater treatment plant, resulted KPC-2, and KPC-3 producers, respectively. Moreover, we report the first detection of mcr-1.2 ST10 E. coli on a conjugative IncX4 plasmid (33.303 bp in size from a stream of

Occurrence of Extended Spectrum β-Lactamases, KPC-Type, and MCR-1.2-Producing Enterobacteriaceae from Wells, River Water, and Wastewater Treatment Plants in Oltrepò Pavese Area, Northern Italy.

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Caltagirone, Mariasofia; Nucleo, Elisabetta; Spalla, Melissa; Zara, Francesca; Novazzi, Federica; Marchetti, Vittoria M; Piazza, Aurora; Bitar, Ibrahim; De Cicco, Marica; Paolucci, Stefania; Pilla, Giorgio; Migliavacca, Roberta; Pagani, Laura

2017-01-01

To evaluate the water compartment antibiotic-resistance contamination rates, 11 wells, five streams, and four treatment plants located in the Oltrepò Pavese area were screened for the presence of third generation cephalosporins resistant Gram-negative bacteria. Enterobacteriaceae were also characterized for the Extended-Spectrum-β-Lactamases (ESBLs), carbapenemases, and mcr-1 genes presence. From December 2014 to November 2015, 246 water samples were filtered, plated on Plate Count Agar, MacConkey Agar, and MacConkey Agar with cefotaxime. Isolates were species identified using AutoSCAN-4-System and ESBLs, carbapenemases, and colistin resistance determinants were characterized by PCR, sequencing, and microarray. Plasmid conjugative transfer experiments, PCR-based Replicon typing, Pulsed-Field Gel Electrophoresis, Multi-Locus-Sequence-Typing, and in-silico plasmid characterization were performed. A total of 132 enterobacteria isolates grew on MacConkey agar with cefotaxime: 82 (62.1%) were obtained from streams, 41 (31.1%) from treatment plants, and 9 (6.8%) from wells. Thirty out of 132 (22.7%) isolates, mainly belonging to Escherichia coli ( n = 15) species, showed a synergic effect with piperacillin-tazobactam. A single ESBL gene of bla CTX-M -type was identified in 19/30 isolates. In further two E. coli strains, a bla CTX-M-1 gene co-existed with a bla SHV -type ESBL determinant. A bla SHV-12 gene was detected in two isolates of E. coli ( n = 1) and Klebsiella oxytoca ( n = 1), while any ESBL determinant was ascertained in seven Yersinia enterocolitica strains. A bla DHA -type gene was detected in a cefoxitin resistant Y. enterocolitica from a stream. Interestingly, two Klebsiella pneumoniae strains of ST307 and ST258, collected from a well and a wastewater treatment plant, resulted KPC-2, and KPC-3 producers, respectively. Moreover, we report the first detection of mcr-1.2 ST10 E. coli on a conjugative IncX4 plasmid (33.303 bp in size) from a stream of Oltrep

Characterization of extended-spectrum β-lactamases (ESBLs)-producing Salmonella in retail raw chicken carcasses.

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Qiao, Jing; Zhang, Qiang; Alali, Walid Q; Wang, Jiawei; Meng, Lingyuan; Xiao, Yingping; Yang, Hua; Chen, Sheng; Cui, Shenghui; Yang, Baowei

2017-05-02

Extended-spectrum β-lactamases (ESBLs)-producing Salmonella is considered a serious concern to public health worldwide. However, limited information is available on ESBLs-producing Salmonella in retail chicken products in China. The objective of this study was to characterize ESBLs-producing Salmonella isolates from retail chickens in China. A total of 890 Salmonella isolates from retail chicken carcasses collected from 4 provinces were firstly screened for ESBLs-production phenotype via the double-disk synergy test method. A total of 96 (10.8%, n=890) ESBLs-producing Salmonella were identified and subjected to PFGE analysis, characterization for the presence of ESBLs encoding genes, transposons, carbapenemase and virulence genes. A total of 59 PFGE profiles were detected in these 96 isolates, among which 57.3% were found to harbor bla TEM-1 , whereas 30.2%, 24.0%, 18.8% and 7.3% were carrying bla OXA-1 , bla CTX-M-15 , bla CTX-M-3 and bla PSE-1 genes, respectively. Moreover, 42 (43.8%) isolates co-carried 2 ESBLs-producing genes, and two (2.1%) isolates co-carried 3 genes. Furthermore, 24 (25.0%) ESBLs-producing isolates carried VIM and 10 (10.4%) carried KPC encoding genes that closely associated with carbapenems resistance. Eighty-eight isolates harbored transposons ranging from 4.2% for Tn903 to 76.0% for Tn21. Out of the 88 Salmonella that harbored transposons, 25%, 22.7%, 23.9%, 10.2% and 1.1% of isolates were found to carry 2, 3, 4, 5 and 6 transposons, respectively. The minimum inhibitory concentration (MIC) values for cephalosporins (ceftriaxone, cefoperazone and cefoxitin) to ESBLs-producing isolates were from 4 to 1024μg/mL, for nalidixic acid were from 64 to 512μg/mL, for fluoroquinolones (ciprofloxacin, levofloxacin and gatifloxacin) were from 4 to 256μg/mL. Twenty-nine virulence genes were detected in the 96 ESBLs-producing isolates with 2.1% harbored spvR (lowest) and 90.6% harbored marT and steB (highest). All isolates carried at least one

First report in Africa of two clinical isolates of Proteus mirabilis carrying Salmonella genomic island (SGI1) variants, SGI1-PmABB and SGI1-W.

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Soliman, Ahmed M; Ahmed, Ashraf M; Shimamoto, Toshi; El-Domany, Ramadan A; Nariya, Hirofumi; Shimamoto, Tadashi

2017-07-01

Two Proteus mirabilis strains, designated PmTAN59 and PmKAF126, were isolated from two different Egyptian cities in 2014 and 2015, respectively. PmTAN59 was isolated from a sputum swab from a pneumonia patient in Tanta University Teaching Hospital. PmKAF126 was isolated from a patient with a diabetic foot infection in a hospital in the city of Kafr El-Sheikh. The two isolates were identified with bacterial small ribosomal RNA (16S rRNA) gene amplification and sequencing and tested for antimicrobial sensitivity with a Kirby-Bauer disk diffusion assay. The two strains were resistant to amoxicillin/clavulante, ampicillin, cefotaxime, cefoxitin, ceftriaxone, chloramphenicol, ciprofloxacin, colistin, gentamicin, kanamycin, nalidixic acid, spectinomycin, streptomycin, sulfamethoxazole/trimethoprime, and tetracycline, but sensitive to aztreonam, imipenem, and meropenem. Molecular characterization was used to map the entire backbone, including the multiple antibiotic resistance (MDR) region, of Salmonella genomic island 1 (SGI1). Both isolates carried a structure similar to SGI1, with two different MDR regions corresponding to SGI1-PmABB in PmTAN59 and SGI1-W in PmKAF126. SGI1-PmABB carried an integron of ~1.5kb with a two-gene cassette, aacCA5-aadA7, which confers resistance to gentamicin, streptomycin, and spectinomycin, whereas SGI1-W carried an integron of ~1.9kb containing aadA2-lnuF, which confers resistance to spectinomycin, streptomycin, and lincosamides. PmKAF126 carried the entire SGI1 sequence, however PmTAN59 carried a SGI1 structure with a deletion in the region from ORF S005 to ORF S009 and accompanied by insertion of IS1359 (1258bp). Furthermore, PmTAN59 carried class 2 integron of ~2.2kb containing dfrA1-sat2-aadA1. An ERIC-PCR analysis detected no clonal relationship between the two strains. Molecular screening for other antimicrobial resistance genes and a plasmid analysis indicated that PmTAN59 carried an IncFIB plasmid type. This strain also carried bla

Prevalence and antimicrobial susceptibility pattern of methicillin resistant Staphylococcus aureus isolated from clinical samples at Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia.

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Dilnessa, Tebelay; Bitew, Adane

2016-08-09

Staphylococcus aureus particularly MRSA strains are one of the major causes of community and hospital acquired bacterial infections. They are also becoming increasingly multi-drug resistant and have recently developed resistance to vancomycin, which has been used successfully to treat MRSA for many years. In-vitro determination of drug resistance patterns of S. aureus is critical for the selection of effective drugs for the treatment of staphylococci infections. The main aim of this study was to determine the prevalence of methicillin resistant S. aureus strains from different clinical specimens from patients referred for routine culture and sensitivity testing. A cross sectional study was conducted among 1360 participants at Yekatit 12 Hospital Medical College in Ethiopia from September 2013 to April 2014. Clinical samples from various anatomical sites of study participants were cultured on blood agar and mannitol salt agar and identified to be S. aureus by using catalase, coagulase and DNAse tests. S. aureus isolates then were screened for MRSA using 30 μg cefoxitin disc and other 11 antimicrobial drugs by disc diffusion procedure, and agar dilution and E tests for vancomycin. All S. aureus isolates examined for beta-lactamase production by employing nitrocefin. Data were analyzed using SPSS version 20 software and logistic regressions were applied to assess any association between dependent and independent variables. Of 1360 clinical specimens analyzed S. aureus was recovered from (194, 14.3 %). Rate of isolation of S. aureus with regard to clinical specimens was the highest in pus (118, 55.4 %).No S. aureus was isolated from CSF and urethral discharge. Out of 194 S. aureus isolates, (34, 17.5 %) were found out to be MRSA and the remaining (160, 82.5 %) were MSSA. Ninety eight (50.5 %) S. aureus were multi drug resistant and the highest isolates were resistant to penicillin (187, 96.4 %) and least resistant for clindamycin (23, 11.9 %) and vancomycin

[Effects of the combined therapy of heat sensitive moxibustion and acupoint injection on endometrial receptivity of hypdrosalphinx infertility in the patients after hysteroscopy and laparoscopy].

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Liu, Yanling; Pan, Lizhen; Wang, Ying

2018-01-12

To explore the effects of the combined therapy of heat sensitive moxibustion and acupoint injection on endometrial receptivity of hypdrosalphinx infertility in the patients after hysteroscopy and laparoscopy on the base of routine post-operative anti-inflammation. A total of 210 patients of hypdrosalphinx infertility after hysteroscopy and laparoscopy were divided into a combined therapy group, a heat sensitive moxibustion group and a control group, 70 cases in each one according to the random number table. In the control group, the intravenous drip of cefoxitin sodium was adopted, and the anti-inflammation treatment was given for 1 week after operation. In the heat sensitive moxibustion group, on the basis of the treatment as the control group, the heat sensitive moxibustion was applied after vaginal bleeding stopped. The acupoints were Yaoyangguan (GV 3), Guanyuan (CV 4), Qihai (CV 6), Shenshu (BL 23), Sanyinjiao (SP 6), Yinlingquan (SP 9) and Zigong (EX-CA1). The acupoints were modified according to the different syndromes. In the combined therapy group, on the basis of the regimen as the heat sensitive moxibustion group, after vaginal bleeding stopped, the acupoint injection was given alternatively at bilateral Tiangong (extra, 1.0 cm inferior and bilateral to the cervix) with lidocaine 1 mL, amikacin 2 mL and salvia injection 2 mL. The treatment was given once every day, the treatment for 10 times as one course and a total of 3 courses were required. The endometrial type, thickness, uterine arterial plusatility index (PI) and resistance index (RI) were observed in the patients of each group. After treatment, the numbers of A-type endometrial type in the combined therapy group and the heat sensitive moxibustion group were remarkably higher than those of the control group [57.1% (40/7) vs 31.4% (22/70), 50.0% (35/70) vs 31.4% (22/70), both P <0.05]. The endometrial thickness after treatment was all increased as compared with that before treatment in each group

[Detection of Staphylococcus aureus resistant to methicillin (MRSA) by molecular biology (Cepheid GeneXpert IL, GeneOhm BD, Roche LightCycler, Hyplex Evigene I2A) versus screening by culture: Economic and practical strategy for the laboratory].

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Laudat, P; Demondion, E; Jouannet, C; Charron, J; Chillou, C; Salaun, V; Mankikian, B

2012-06-01

Patients admitted in cardiac surgery and cardiac ICU at the Clinic Saint-Gatien (Tours) are screened for MRSA at the entrance by nasal swab and culture on blood agar and selective chromogenic medium made by addition of cefoxitin: BBL CHROMagar MRSA-II BD (result obtained at Day +1). We wanted to assess the molecular biology techniques available to obtain a result at day 0 for the majority of patients and to define an economic and practical strategy for the laboratory. We studied four molecular biology techniques: Cepheid GeneXpert (Cepheid) GeneOhm (BD), LightCycler (Roche) and Hyplex (I2A). Upon reception, nasal swabs were treated by culture, considered as reference, and one of the techniques of molecular biology, according to the manufacturer's notice. We conducted four studies between April 2008 and February 2009 to obtain a significant sample for each of them. By screening we mean a method that allows us to exclude MRSA carriage for patients waiting for surgery, and not to change patient management: for example, lack of isolation measures specific to entrance, no modification of antibiotic prophylaxis during surgery and no isolation measures in the immediate postoperative period. The criteria we considered for this evaluation were: (1) technician time: time to perform one or a series of sample(s) n=10 or more (about 2h for all techniques except GeneXpert 75min), level of skilled competences (no specific training for GeneXpert); (2) results: turnaround time (all molecular biology techniques), ease of reading and results interpretations (no specialized training required for GeneXpert), failure or not (12% of failure of internal controls for GeneOhm); (3) economic: cost for one or a series of sample(s) (n=10 or more), if we considered X as the reference culture cost (10 X Hyplex and LightCycler, 20 X and 40 X for GeneXpert GeneOhm); (4) NPV: 100% for GeneXpert and LightCycler. At same sensitivity, no technique, including culture, can solve alone our problem, which

Isolation and Identification of the Pathogens of the Skin Ulceration Disease in Lateolabrax japonicus%花鲈皮肤溃疡病病原菌的分离与鉴定

Institute of Scientific and Technical Information of China (English)

林星

2013-01-01

为了确定海水池塘养殖花鲈发生皮肤溃疡病的病原菌及其防治方法。利用莆田市人工饲养的花鲈中挑取具有皮肤溃疡病明显症状的幼鱼，从体表病灶和体内组织中分离出病原菌，通过人工感染试验、细菌形态观察及常规生理生化指标测定对其进行了分类学鉴定，同时进行药敏试验。结果表明：引起该养殖场皮肤溃疡病的病原菌为哈维氏弧菌，该菌对复方新诺明、阿莫西林、哌拉西林、替卡西林、头孢拉定、头孢噻肟、头孢吡肟、头孢他啶、头孢呋辛钠、美罗培南、头孢西丁、卡那霉素、奈替米星、阿米卡星等14种药物敏感，对米诺环素、链霉素等抗生素表现出耐药。在实际生产上采用饲料中添加复方新诺明和维生素C的方法来治疗花鲈皮肤溃疡病，连续用药10天后，取得了较好的疗效。%In order to find the pathogens of the ulceration disease of Lateolabrax japonicus in seawater pond culture and the prevention and control methods of its diseases and pests, the diseased ulceration diseasal Lateolabrax japonicus were selected from Putian bacterials were isolated from the disease Lateolabrax-japonicus and were confirmed to be the pathogen of the disease by artificial infection test. According to the results, morphological feature, physiological and biochemical characteristics were very similar to Vibrio-harveyi. Experiments showed that Aeromonas hydrophila was sensitive to Cotrimoxazole, Amoxicillin,Piperacillin,Ticarcillin,Cefradine,Cefotaxime,Cefepime,Ceftazidime,Cefuroximesodium, Meropenem, Cefoxitin, Amikacin, Netilmicin, Amikacinand other 14 kinds of antibiotics, but it was insensitive to minocycline, streptomycin and so on. By adding compound Cotrimoxazole and vitamin C in feed to the treatment of Lateolabrax japonicus skin ulcer disease in the actual production, continuous administration for 10 days, has obtained the good curative effect.

Randomized clinical trial comparing spinal anesthesia with local anesthesia with sedation for loop colostomy closure Ensaio clínico randomizado comparando raquianestesia com anestesia local, associadas à sedação para o fechamento de colostomia em alça

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Rone Antônio Alves de Abreu

2010-09-01

Full Text Available CONTEXT: Recent studies have shown that local anesthesia for loop colostomy closure is as safe as spinal anesthesia for this procedure. OBJECTIVES: Randomized clinical trial to compare the results from these two techniques. METHODS: Fifty patients were randomized for loop colostomy closure using spinal anesthesia (n = 25 and using local anesthesia (n = 25. Preoperatively, the bowel was evaluated by means of colonoscopy, and bowel preparation was performed with 10% oral mannitol solution and physiological saline solution for lavage through the distal colostomy orifice. All patients were given prophylactic antibiotics (cefoxitin. Pain, analgesia, reestablishment of peristaltism or peristalsis, diet reintroduction, length of hospitalization and rehospitalization were analyzed postoperatively. RESULTS: Surgery duration and local complications were greater in the spinal anesthesia group. Conversion to general anesthesia occurred only with spinal anesthesia. There was no difference in intraoperative pain between the groups, but postoperative pain, reestablishment of peristaltism or peristalsis, diet reintroduction and length of hospitalization were lower with local anesthesia. CONCLUSIONS: Local anesthesia plus sedation offers a safer and more effective method than spinal anesthesia for loop colostomy closure.CONTEXTO: Estudos recentes têm demonstrado que a anestesia local para o fechamento de colostomia em alça é tão segura quanto a raquianestesia para estes procedimentos. OBJETIVOS: Comparar os resultados do fechamento de colostomia em alça usando essas duas técnicas. MÉTODOS: Cinquenta pacientes foram randomizados para o fechamento de colostomia em alça sob raquianestesia (n = 25 e anestesia local (n = 25. No pré-operatório, o cólon foi avaliado por colonoscopia e o preparo intestinal foi realizado com solução oral de manitol a 10% e limpeza com solução salina fisiológica através do orifício distal da colostomia. Todos os

Detection, seroprevalence and antimicrobial resistance of Yersinia enterocolitica and Yersinia pseudotuberculosis in pig tonsils in Northern Italy.

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Bonardi, S; Bruini, I; D'Incau, M; Van Damme, I; Carniel, E; Brémont, S; Cavallini, P; Tagliabue, S; Brindani, F

2016-10-17

Yersiniosis is the third most common reported zoonoses in Europe, with Y. enterocolitica and Y. pseudotuberculosis responsible for 98.66% and 0.94% of the confirmed human cases in 2013. From June 2013 to October 2014, 201 pigs at slaughter belonging to 67 batches were tested for Y. enterocolitica and Y. pseudotuberculosis in tonsils. Diaphragm muscle samples were tested for antibodies against Yersinia by a commercially available ELISA test. Y. enterocolitica 4/O:3 was detected in 55/201 pig tonsils (27.4%; 95% CI 23.1-37.1). The positive pigs came from 38/67 batches (56.7%) and were reared in 36/61 farms (59.0%). There was no statistical difference between farrow-to-finish and finishing farms. The mean count of Y. enterocolitica was 3.56±0.85log10CFU/g with a minimum of 2.0log10CFU/g and a maximum of 4.78log10CFU/g. Y. pseudotuberculosis was isolated from 4/201 pig tonsils (2.0%; 95% CI 0.0-4.5). Three isolates belonged to serotype O:3 and one to serotype O:1. The positive pigs belonged to 4/67 batches (6.0%) and came from finishing farms only. Y. pseudotuberculosis could be enumerated in one sample only (4.27log10CFU/g). The ELISA test demonstrated that 56.1% of the meat juice samples were positive for Yersinia antibodies. Serological positivity was found in 67.9% (36/53) of the Y. enterocolitica- and 75.0% (3/4) of the Y. pseudotuberculosis positive pigs. A significant association was found between serological results and the presence of Y. enterocolitica in tonsils (OR=1.97, p=0.044). All the Y. enterocolitica 4/O:3 isolates were susceptible to amoxicillin-clavulanic acid, gentamicin, ceftazidime, ertapenem and meropenem, 94.5% to cefotaxime, 89.1% to kanamycin and 78.2% to tetracycline. The highest resistance rates were observed for ampicillin (100%), sulphonamides (98.2%) and streptomycin (78.2%). Y. pseudotuberculosis strains were sensitive to all the antimicrobials tested, i.e. amoxicillin, amoxicillin/clavulanic acid, azithromycin, cephalothin, cefoxitin

Bacteremias por Staphylococcus coagulase negativos oxacilina resistentes em um hospital escola na cidade de Santa Maria, Estado do Rio Grande do Sul Oxacillin-resistant coagulase-negative Staphylococci bacteremia at a teaching hospital in Santa Maria, State of Rio Grande do Sul, Brazil

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Fabiane Rigatti

2010-12-01

isolates were tested for antimicrobial sensitivity using disk diffusion and automation (MicroScan® - Siemens. The presence of mecA gene was identified by the polymerase chain reaction molecular technique. RESULTS: The most common species was Staphylococcus epidermidis (n=40, 67%. The mecA gene was detected in 54 (90% strains, while analysis of the sensitivity profiles revealed a high rate of resistance to multiple classes of antimicrobial drugs. However, all isolates were uniformly sensitive to vancomycin and tigecycline. The cefoxitin disk was the phenotypic method that best correlated with the gold standard. CONCLUSIONS: Analysis of the clinical significance of CoNS isolated from hemocultures and the precise detection of oxacillin resistance represent decisive factors for the correct choice of antibiotic therapy. Although vancomycin constitutes the normal treatment in most Brazilian hospitals, reduction in its use is recommended.

Caracterização de Staphylococcus aureus isolados da barra de mão de carrinhos e alças de cestas de supermercados

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Daiane Buzzatto Oliveira

2016-07-01

supermarkets from the city of Campo Mourão – PR, and characterize the susceptibility of isolates to oxacillin. One hundred twenty samples, of which 60 collected from bars hand stands and collected 60 of the handles of baskets. This micro-organism was isolated in 75 samples (62.5%, and of this total, 35 samples (46,7% were isolated from carts and 40 (53,3% of shopping baskets. The positive samples for Staphylococcus aureus were submitted to susceptibility testing by the disk diffusion method to oxacillin (cefoxitin and all samples were found to be sensitive to this drug. It found that the bars of hands and the handles of supermarket baskets can be considered as fomites in the dissemination of Staphylococcus aureus, being extremely important to sanitization these objects in order to reduce the risk of contamination in the community.Keywords: Surfaces. Contamination. Staphylococcus aureus. Oxacillin.

Microbiological and biochemical studies on certain antibiotic-resistant bacteria isolated from certain clinical specimens

Energy Technology Data Exchange (ETDEWEB)

Nada, H M.AL.M. [National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt)

2008-07-01

. Determination of B-lactamase and AmpC-B-lactamase enzyme production were carried out by two methods. Cefotaxime, ceftazidime, cefoperazone, cefoxitin and aztreonam were used with and without amoxycillin clavulanic acid to detect the presence of extended-spectrum B-lactamase (ESBL) harbouring isolates by using double-disk diffusion synergy test (DDST). Combined disk method was used also to detect the presence of ESBL harbouring isolates by using cefoperazone (CFP) and cefoperazone sulbactam (SCF) among the tested strains. Agar dilution method was used to determine minimum inhibitory concentration (MIC) of ampicillin sulbactam, cefoperazone, gentamycin and levofloxacin alone and in combination (Ampicillin sulbactam with both of gentamycin and levofloxacin) and (cefoperazone with both of gentamycin and levofloxacin). Fractional inhibitory concentration (FIC) for the combined antibiotics were calculated according to checkerboard method and synergistic effect were determined. Some resistant isolates were subjected to molecular studies including plasmid profile (Kleb.52 Morg.60 and Ps.72 ) by using a high pure plasmid isolation kit and protein pattern of Ps.72 before and after irradiation in the presence of different antibiotics alone (cefoperazone, gentamycin and ampicillin sulbactam) or in combined (cefoperazone with gentamycin and ampicillin sulbactam with gentamycin)The result of the present investigation showed that, 9 multi-drug resistant isolates were identified as; 2 isolates Escherichia coli, 2 isolates Pseudomonas aeruginosa, 1 isolate Citrobacter freundii, 1 isolate Morganella morganii all were isolated from urine samples.

Microbiological and biochemical studies on certain antibiotic-resistant bacteria isolated from certain clinical specimens

International Nuclear Information System (INIS)

Nada, H.M.AL.M.

2008-01-01

. Determination of B-lactamase and AmpC-B-lactamase enzyme production were carried out by two methods. Cefotaxime, ceftazidime, cefoperazone, cefoxitin and aztreonam were used with and without amoxycillin clavulanic acid to detect the presence of extended-spectrum B-lactamase (ESBL) harbouring isolates by using double-disk diffusion synergy test (DDST). Combined disk method was used also to detect the presence of ESBL harbouring isolates by using cefoperazone (CFP) and cefoperazone sulbactam (SCF) among the tested strains. Agar dilution method was used to determine minimum inhibitory concentration (MIC) of ampicillin sulbactam, cefoperazone, gentamycin and levofloxacin alone and in combination (Ampicillin sulbactam with both of gentamycin and levofloxacin) and (cefoperazone with both of gentamycin and levofloxacin). Fractional inhibitory concentration (FIC) for the combined antibiotics were calculated according to checkerboard method and synergistic effect were determined. Some resistant isolates were subjected to molecular studies including plasmid profile (Kleb.52 Morg.60 and Ps.72 ) by using a high pure plasmid isolation kit and protein pattern of Ps.72 before and after irradiation in the presence of different antibiotics alone (cefoperazone, gentamycin and ampicillin sulbactam) or in combined (cefoperazone with gentamycin and ampicillin sulbactam with gentamycin)The result of the present investigation showed that, 9 multi-drug resistant isolates were identified as; 2 isolates Escherichia coli, 2 isolates Pseudomonas aeruginosa, 1 isolate Citrobacter freundii, 1 isolate Morganella morganii all were isolated from urine samples

Environmental "Omics" of International Space Station: Insights, Significance, and Consequences

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Venkateswaran, Kasthuri

2016-07-01

detected. The nine-erythromycin sensitive S. aureus strains exhibited spontaneous mutation when rifampin was tested. Some of the S. aureus strains tolerated gentamycin and tobramycin but cefazolin, cefoxitin, ciprofloxacin and oxacillin inhibited the growth of the S. aureus. Whole genome sequencing (WGS) of 21 ISS strains, exhibiting resistance to various antibiotics, was carried out. The antibiotic resistant genes deduced from the WGS were compared with the resistomes generated directly from the gene pool of the environmental samples. Using a targeted amplification panel consisting of over 500 antimicrobial resistance genes, we were able to confirm the results of the phenotypic assays. Specifically, the presence of multiple β-lactamase genes was observed. The class A β-lactamase genes, tem-1 (ampicillin-resistance) and ctx-M-14 (cefotaxime conferring gene), were found in multiple sites of ISS. In addition, presence of mecA gene (penicillin clusters) was confirmed in several sampling locations from both ISS flights. Finally, the existence of the ermA gene (erythromycin) was established. These results suggest widespread and consistent distribution of multiple antibiotic resistance genes throughout the ISS. The resistome data generated via molecular methods will be extremely important in determining the microbial significance to the crew health and the ISS maintenance. These data sets will be placed in the NASA GeneLab bioinformatics environment - consisting of a database, computational tools, and improved methods - that would subsequently be made open to the scientific research community to encourage innovation.

Antimicrobial resistance profile of Staphylococcus aureus isolates obtained from skin and soft tissue infections of outpatients from a university hospital in Recife -PE, Brazil Perfil de resistência antimicrobiana de isolados de Staphylococcus aureus provenientes de infecções de pele e tecidos moles de pacientes ambulatoriais de um hospital universitário em Recife - PE, Brasil

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Fabiana Beserra Caraciolo

2012-12-01

Full Text Available BACKGROUND: Staphylococcus aureus has a notable ability to acquire resistance to antibiotics, and methicillin resistance represents a growing public health problem. Methicillin-resistant S. aureus (MRSA has also become important outside the hospital environment, particularly in the United States. In Brazil, since 2005, cases of community skin infections caused by MRSA have been reported, but resistance studies involving outpatients are scarce. OBJECTIVE: To know the resistance profile of S. aureus involved in skin and soft tissue infections of patients seen at the Dermatology outpatient clinic of a university hospital in Recife, Pernambuco State, northeastern Brazil. METHODS: Prospective study involving 30 patients with skin and soft tissue infections, seen at the Dermatology outpatient clinic from May until November 2011. To evaluate the susceptibility of S. aureus to antibiotics, the disk diffusion method and oxacillin screening agar were used. RESULTS: From a total of 30 samples of skin lesions, 19 (63% had positive culture for S. aureus. The following resistance patterns of S. aureus were observed: penicillin, 95%; tetracycline, 32%; erythromycin, 21%; gentamicin, 16%; cefoxitin, 11%; oxacillin, 11%; trimethoprim-sulfamethoxazole, 11%; chloramphenicol, 11%; clindamycin, 5% ; and ciprofloxacin, 0%. One of the identified MRSA was obtained from a patient without risk factors for its acquisition, and was resistant, beyond to the beta-lactams, only to tetracycline. CONCLUSIONS: With regard to the resistance patterns of S. aureus, resistances to tetracycline, erythromycin and gentamicin were the highest. It was documented, for the first time in Pernambuco, a case of skin infection caused by community-associated MRSA.FUNDAMENTOS: O Staphylococcus aureus possui uma notável habilidade de adquirir resistência antimicrobiana, sendo a resistência à meticilina um problema de saúde pública crescente. O S. aureus resistente à meticilina (MRSA vem se

Staphylococcus aureus: incidência e resistência antimicrobiana em abscessos cutâneos de origem comunitária Staphylococcus aureus: etiology and susceptibility profile to antimicrobial agents of skin and subcutaneous cell tissue abscesses from community infections

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Martin Zavadinack Netto

2002-03-01

profilaxia ou tratamento de infecções por S.aureus, mesmo aqueles de origem comunitária.An analysis of Staphylococcus aureus (Monera, an etiological agent of community infections, is provided. Staphylococcus aureus causes the formation of skin and subcutaneous cell tissue abscesses. Susceptibility profile to antimicrobials used in prophylaxis or therapy of these cutaneous infections will be given. One hundred and seven samples of secretions were collected from January 1996 through July 1997 at the emergency sector of University Hospital of the State University of Maringá, Maringá, state of Paraná, Brazil, from infected patients with skin and subcutaneous cell tissue abscesses. Microbiological evaluation was carried out according to Bayle and susceptibility to antimicrobial was evaluated in vitro through the technique of diffusion in agar according to Kirby. Sixteen antimicrobials used in prophylaxis or therapy of skin and subcutaneous cell tissue infections were evaluated. From the one hundred and seven clinical samples collected from patients complaining of infections with skin and subcutaneous cell tissue abscesses, 71 (66.35% were positive to S.aureus and 36 (33,65% were either positive for other microorganisms, or tested negative. In the evaluation of susceptibility to S.aureus a higher sensitivity to vancomycin (100%, teicoplanin (100%, amikacin (100%, cefoxitin (100%, cephalothin (98.53%, lincomycin (98.53%, gentamicin (98.53%, oxacillin (96,4%, norfloxacin (95.77% and sulfazotrin (95.77% was found when compared to penicillin G (08.45%, ampicillin (08.45%, kanamycin (81,69%, erythromycin (88.41%, tetracycline (90.14 and chloramphenicol (94,36%. Results show that S.aureus is the most frequently isolated microorganism from community infections with skin and subcutaneous tissue abscesses. The susceptibility profile evidences high resistance to penicillins, which restricts the use of these antimicrobials as an alternative in the prophylaxis or treatment of S

Laboratory detection methods for methicillin resistance in coagulase negative Staphylococcus isolated from ophthalmic infections Métodos laboratoriais para a detecção da resistência à meticilina nos Staphylococcus coagulase negativos de infecções oculares

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Adália Dias Dourado Oliveira

2007-08-01

Full Text Available PURPOSE: To evaluate different methods of oxacillin susceptibility testing of ocular isolates, considering polymerase chain reaction (PCR as the 'gold standard', and to compare the in vitro susceptibility to oxacillin with that of other antimicrobials used in ophthalmologic practice. METHODS: The Vitek gram-positive identification card was used to identify ocular coagulase negative Staphylococcus species. The presence of the mecA gene was determined by the polymerase chain reaction assay with a combination of two primer sets (mecA and 16S rRNA in a single region. Results were analyzed and compared with other oxacillin susceptibility methods: PBP2a detection by rapid slide latex agglutination test (SLA; oxacillin E-test; the Vitek automated gram-positive susceptibility card (GPS-105; the oxacillin salt agar screening test (OSAS at a concentration of 6.0, 1.0 and 0.75 µg oxacillin per ml and the cefoxitin disk diffusion test (CDD. Automated susceptibility was also determined to other antimicrobial agents (fluoroquinolones, penicillin G, amoxicillin-ampicillin, cefazolin, ampicillin-sulbactam, erythromycin, clindamycin, gentamicin, tetracycline, trimethoprim-sulfamethoxazole, vancomycin and rifampin. RESULTS: Of the 69 CoNS isolates tested, 71% were mecA-positive and 29% mecA-negative. All methods tested had a statistically significant agreement with polymerase chain reaction. There was a tendency of positive polymerase chain reaction predomination among the S. epidermidis isolates in comparison to non-epidermidis isolates, although this was not statistically significant (78.3% vs. 56.5%; chi2= 2.54; P= 0.11. The oxacillin salt agar screening test (0.75 µg oxacillin/ml showed the best performance, with 100% sensitivity and negative predictive value; 95% specificity and 98% positive predictive value. Using the E-test, the mecA-positive isolates were statistically significantly more resistant to ciprofloxacin, ofloxacin, gatifloxacin and

Etiologia e perfil de sensibilidade de bactérias isoladas de ovelhas com mastite na região nordeste do estado do Pará Etiology and antimicrobial susceptibilities of bacteria isolated from sheep with mastitis in northeastern Pará, Brazil

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Natália da Silva e Silva

2010-12-01

isolated were Staphylococcus spp. coagulase negative (26.9%; Staphylococcus aureus (15.,4%; Streptococcus spp. (7.69%; Escherichia coli (7.69% and Citrobacter freundii (11.5%. Were observed associations of Staphylococcus spp. coagulase negative nonhemolytic and Staphylococcus spp. coagulase negative hemolytic (3.85%. The most efficient antibiotics for the Gram positive agents were penicile/novobiocine (100%, cefalotine (100% and florfenicol (100% and for the Citrobacter freundii were ampicilina (100% and florfenicol (100%. In relation to Escherichia coli, 66.7% of isolates to ampicillin, cephalothin, florfenicol and tetracycline were resistant. Mastitis is present in sheep in the State of Pará, and it's necessary to estimate, in future studies, the economic losses caused by this disease. The CMT show satisfactory results and can be recommended as a screening test for diagnosing individual cases of subclinical mastitis in sheep, once had a good relationship with the microbiological examination. In the antibiogram where most of the isolated agents appear sensitive to different antibiotics tested, the antibiotics with the best efficiency were florfenicol and cefoxitin.