PRESENCE OF ENTEROCOCCI IN COW MILK AND THEIR ANTIBIOTIC RESISTANCE

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Miroslav Kročko

2010-05-01

Full Text Available Enterococci represent an important part of contaminate microflora in raw milk and dairy products. They constitute significant part of nosocomial pathogens with a remarkable capacity of expressing resistance to several antimicrobial  agents. We aimed to assess occurrence and antibiotic resistance of enterococci in the raw milk samples and pasteurized milk samples. In this study total bacterial count, psychrotrophic count and count of enterococci were determine in raw milk cistern samples, storage tank milk samples and milk samples after pasteurization. A collection of 46 enterococcal isolates were identified and screened for their antibiotic resistance. Isolates of E. faecalis were dominant in raw milk samples (56.5 %. Sensitive to teicoplanine (30 mcg/disk were 97.9 % of enterococcal isolates and 15.2 % isolates were resistant to vankomycin (30 mcg/disk.  

Molecular characterization of antibiotic resistance in enterococci recovered from seagulls (Larus cachinnans) representing an environmental health problem.

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Radhouani, Hajer; Igrejas, Gilberto; Pinto, Luís; Gonçalves, Alexandre; Coelho, Céline; Rodrigues, Jorge; Poeta, Patrícia

2011-08-01

Antimicrobial resistance and the mechanisms implicated were studied in 54 enterococci recovered from 57 seagull fecal samples. Almost 78% of the recovered enterococci showed resistance against one or more antibiotics and these isolates were identified to the species level. E. faecium was the most prevalent species (52.4%). High percentages of erythromycin and tetracycline resistances were found among our isolates (95.2%), and lower percentages were identified to other antibiotics. Most of the tetracycline-resistant strains carried the tet(M) and/or tet(L) genes. Genes associated with Tn916/Tn1545 and/or Tn5397 transposons were detected in 45% of tetracycline-resistant isolates. The erm(B) gene was detected in 65% of erythromycin-resistant isolates. The vat(D) and vat(E) genes were present in 5.9% and 11.8% of quinupristin/dalfopristin-resistant isolates, respectively. The ant(6)-Ia gene was identified in 57.1% of streptomycin-resistant isolates. All nine kanamycin-resistant isolates carried the aph(3)'-IIIa gene. The cat(A) gene was found in two chloramphenicol-resistant isolates. Seagulls should be considered a risk species for spreading in the environment antimicrobial resistant enterococci and can serve as a sentinel for antibiotic pressure from the surrounding farm and urban setting.

Antibiotic-Resistant Enteric Bacteria in Environmental Waters

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Lisa M. Casanova

2016-11-01

Full Text Available Sources of antibiotic resistant organisms, including concentrated animal feeding operations (CAFOs, may lead to environmental surface and groundwater contamination with resistant enteric bacteria of public health concern. The objective of this research is to determine whether Salmonella, Escherichia coli, Yersinia enterocolitica, and enterococci resistant to clinically relevant antibiotics are present in surface and groundwater sources in two eastern North Carolina counties, Craven and Wayne. 100 surface and groundwater sites were sampled for Salmonella, E. coli, and enterococci, and the bacteria isolated from these samples were tested for susceptibility to clinically relevant antibiotics. Salmonella were detected at low levels in some surface but not groundwater. E. coli were in surface waters but not ground in both counties. Enterococci were present in surface water and a small number of groundwater sites. Yersinia was not found. Bacterial densities were similar in both counties. For Salmonella in surface water, the most frequent type of resistance was to sulfamethoxazole. There was no ciprofloxacin resistance. There were a few surface water E. coli isolates resistant to chloramphenicol, gentamicin, and ampicillin. Enterococci in surface water had very low levels of resistance to vancomycin, chloramphenicol, ampicillin, and streptomycin. E. coli and enterococci are present more frequently and at higher levels in surface water than Salmonella, but groundwater contamination with any of these organisms was rare, and low levels of resistance can be found sporadically. Resistant bacteria are relatively uncommon in these eastern N.C. surface and groundwaters, but they could pose a risk of human exposure via ingestion or primary contact recreation.

Presence of Antibiotic Resistant Enterococci in Rinses of Milking Equipment after Sanitation Process

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Miroslav Kročko

2011-10-01

Full Text Available Enterococci are common milk contaminants, and microbial contamination of milk by this group of microorganisms can occur from a variety of sources. Significance of enterococci can be assessed by many separated points of view, otherwise a lot of research has focused on the potential role of food enterococci as reservoirs and/or vehicles of antibiotic resistance. The aim of this investigation was to evaluate the occurence of enterococci in rinses of milking equipment (n = 38 on two farms using automatic sanitation system. Our results showed, that alkaline disinfectant (on chlorine basis was effective towards enterococci because apart from 2 samples, their presence in rinses has not been determined. Average number of enterococci survived the aplication of acid disinfectant reached the value 5.00.101 CFU.ml-1. Together, 60 strains were randomly isolated and identified from the grown colonies of genus Enterococcus, and E. faecalis was the predominat species (69.6 %. In rinses, also E. faecium, E. mundtii and undefined enterococci were found. Among antibiotic resistant isolates, 83.9 % of isolates were sensitive to erytromycin (15mcg/disk and resistant to vancomycin (30 mcg/disk were 20 % of isolates.

Antimicrobial susceptibility and glycopeptide-resistance of enterococci in vegetables

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Ida Torre

2010-03-01

Full Text Available

Background: Vancomycin-resistant enterococci (VRE, often responsible for nosocomial infections, have frequently been isolated from animal and vegetable foods. In our study we evaluated the antibiotic susceptibility of enterococci isolated from eight types of vegetables randomly selected from grocery stores in Naples.

Methods: From July to November 2008, we analyzed 150 samples: the bacteria were isolated with standardized methods and antibiotic susceptibility was determined using the disc diffusion method. The resistance to vancomycin versus other antibiotics was assessed by the Kappa test.

Results: 70% of the samples, mainly parsley (96.2%, showed enterococci. Of these, 59.1% belonged to the species Enterococcus faecium. Strains resistant to vancomycin and teicoplanin were isolated respectively in 47.6% and 49.5% of the samples: the first one mainly in curly endive (72.7% and the second one in parsley (76.9%. Almost all the isolated strains showed resistance to methicillin (89%, kanamycin (82% and cephalothin (68%. The Kappa test showed statistically significant associations between resistance to vancomycin and resistance to teicoplanin, erythromycin, methicillin, tetracycline and chloramphenicol.

Conclusions: Because of the possible involvement of food in the transmission of resistant micro-organisms to human intestinal microbiota, our data may provide the basis for future studies.

Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics

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Rathe, Mathias; Lise, Kristensen,; Ellermann-Eriksen, Svend

Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics......Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics...

Antimicrobial resistance among enterococci from pigs in three European countries

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Aarestrup, Frank Møller; Hasman, Henrik; Jensen, Lars Bogø

2002-01-01

to the amounts of antimicrobial agents used in food animal production in those countries. Similar genes were found to encode resistance in the different countries, but the tet(L) and let(S) genes were more frequently found among isolates from Spain. A recently identified transferable copper resistance gene......Enterococci from pigs in Denmark, Spain, and Sweden were examined for susceptibility to antimicrobial agents and copper and the presence of selected resistance genes. The greatest levels of resistance were found among isolates from Spain and Denmark compared to those from Sweden, which corresponds...... was found in all copper-resistant isolates from the different countries....

Our experiences with vancomycin-resistant enterococci in Jesenice General hospital

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Helena Ribič

2007-11-01

Full Text Available Background: Vancomycin-resistant enterococci (VRE present a great problem in health care, especially because of their resistance to many groups of antibiotics and because of the way of their spreading in health care and long-term care institutions. Genes responsible for resistance to vancomycin can be transmitted to other species of enterococci and also to other grampositive cocci, for example Staphylococcus aureus. Experts anticipate that failure to control methicilin-resistant S. aureus and VRE may make control of vancomycin-resistant S. aureus impossible.Methods: In the medical microbiology laboratory of Institute Public Health Kranj we perform microbiology diagnosis for Jesenice General Hospital, where surveillance culturing for VRE started in May 2007. Until 15th June, 364 surveillance samples for VRE were taken from 92 patients. We also analysed the results of enterococci that were isolated in our laboratory during routine work in the period from 2004 to 2006.Results: In the three-year period we isolated 1593 strains of enterococci and among them 7 strains were VRE. In the Jesenice General Hospital, the first strain of vancomycin-resistant Enterococcus faecium was isolated in May 2007 in a patient, treated in internal intensive care unit. Nine strains of VRE with the same resistance type in nine patients followed the first case. The first four patients with VRE were moved from the same hospital. Among next six patients the common risk factor was contact with VRE positive patient.Conclusions: Control of VRE strains claims for intensive action. Active surveillance of colonised and infected patients, contact precautions with barrier isolation, intensive hand hygiene measures, aggressive environmental decontamination and prudent use of antimicrobials are needed.

Vancomycin resistant enterococci in farm animals – occurrence and importance

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Oskar Nilsson

2012-04-01

Full Text Available The view on enterococci has over the years shifted from harmless commensals to opportunistic but important pathogens mainly causing nosocomial infections. One important part of this development is the emergence of vancomycin resistance enterococci (VRE. The term VRE includes several combinations of bacterial species and resistance genes of which the most clinically important is Enterococcus faecium with vanA type vancomycin resistance. This variant is also the most common VRE among farm animals. The reason for VRE being present among farm animals is selection by extensive use of the vancomycin analog avoparcin for growth promotion. Once the use of avoparcin was discontinued, the prevalence of VRE among farm animals decreased. However, VRE are still present among farm animals and by spread via food products they could potentially have a negative impact on public health. This review is based on the PhD thesis Vancomycin Resistant Enterococci in Swedish Broilers – Emergence, Epidemiology and Elimination and makes a short summary of VRE in humans and food producing animals. The specific situation regarding VRE in Swedish broiler production is also mentioned.

Linezolid-resistant clinical isolates of enterococci and Staphylococcus cohnii from a multicentre study in China: molecular epidemiology and resistance mechanisms.

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Chen, Hongbin; Wu, Weiyuan; Ni, Ming; Liu, Yingmei; Zhang, Jixia; Xia, Fei; He, Wenqiang; Wang, Qi; Wang, Zhanwei; Cao, Bin; Wang, Hui

2013-10-01

Genetic characterisation of linezolid-resistant Gram-positive cocci in a multicentre study in China has not been reported previously. To study the mechanism underlying the resistance of linezolid-resistant isolates, nine Enterococcus faecalis, one Enterococcus faecium and three Staphylococcus cohnii isolates with various levels of resistance were collected from five hospitals across China in 2009-2012. The nine E. faecalis isolates were classified into seven sequence types, indicating that these linezolid-resistant E. faecalis isolates were polyclonal. Enterococci isolates had reduced susceptibility to linezolid (MICs of 4-8 mg/L) and had mutation of ribosomal protein L3, with three also having mutation of L4, but without the multidrug resistance gene cfr or the 23S rRNA mutation G2576T. The three S. cohnii isolates were highly resistant to linezolid (MICs of 64 mg/L to >256 mg/L), harboured the cfr gene and had the 23S rRNA mutation G2576T. Southern blotting indicated that the cfr gene of these three isolates resided on different plasmids (pHK01, pRM01 and pRA01). In plasmid pHK01, IS21-558 and the cfr gene were integrated into transposon Tn558. In plasmids pRM01 and pRA01, the cfr gene was flanked by two copies of an IS256-like insertion sequence, indicating that the transferable form of linezolid resistance is conferred by the cfr gene. In conclusion, the emergence of linezolid-resistant Gram-positive cocci in different regions of China is of concern. The cfr gene and the 23S rRNA mutation contribute to high-level linezolid resistance in S. cohnii, and the L3 and L4 mutations are associated with low-level linezolid resistance in enterococci. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Quantitative assessment of faecal shedding of β-lactam-resistant Escherichia coli and enterococci in dogs

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Gongora, Carmen Espinosa; Shah, Syed Qaswar Ali; Jessen, Lisbeth Rem

2015-01-01

Quantitative data on faecal shedding of antimicrobial resistant bacteria are crucial to assess the risk of transmission from dogs to other animals as well as humans. In this study we investigated prevalence and concentrations of β-lactam-resistant Escherichia coli and enterococci in the faeces...... of 108 dogs presenting at a veterinary hospital in Denmark. The dogs had not been treated with antimicrobials for 4 weeks prior to the study. Total E. coli and enterococci were quantified by counts on MacConkey and Slanetz-Bartley, respectively. Resistant E. coli and enterococci were counted on the same...... media containing relevant antibiotic concentrations, followed by species identification using MALDI-TOF. Ampicillin- and cefotaxime-resistant E. coli were detected in 40% and 8% of the dogs, respectively, whereas approximately 15% carried ampicillin-resistant enterococci, mainly Enterococcus faecium...

[Vancomycin-resistant enterococci - the nature of resistance and risk of transmission from animals to humans].

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Hermanovská, Lýdia; Bardoň, Jan; Čermák, Pavel

2016-06-01

Enterococci are part of the normal intestinal flora of humans and animals. Under certain circumstances, they are capable of extraintestinal conversion to opportunistic pathogens. They cause endogenous as well as exogenous community and nosocomial infections. The gastrointestinal tract of mammals provides them with favorable conditions for acquisition and spread of resistance genes, for example to vancomycin (van), from other symbiotic bacteria. Thus, vancomycin-resistant enterococci (VRE) become potential reservoirs and vectors of the van genes. Their occurrence in the population of the Czech Republic was first reported by Kolář et al. in 1997. Some variants of the vanA gene cluster carried on Tn1546 which encode resistance to vancomycin are identical in humans and in animals. It means that animals, especially cattle, poultry and pigs, could be an important reservoir of VRE for humans. Kolář and Bardoň detected VRE in animals in the Czech Republic for the first time in 2000. In Europe, the glycopeptide antibiotic avoparcin, used as a growth stimulator, is responsible for selection of VRE strains in animals. Strains of Enterococcus faecium from animals may offer genes of antimicrobial resistance to other enterococci or they can be directly dangerous to human. This is demonstrated by finding isolates of E. faecalis from human patients and from pigs having very similar profiles of resistance and virulence genes. The goal of the paper was to point out the similarity between isolates of human and animal strains of enterococci resistant to vancomycin, and the possibility of their bilateral transfer between humans and animals.

Emergence of unusual species of enterococci causing infections, South India

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Rao Sambasiva R

2005-03-01

emergence of high-level aminoglycoside and beta-lactam resistance among different species apart from intrinsic vancomycin resistance by some species, while all the species tested were susceptible for linezolid and teicoplanin. Conclusion Our study reveals the emergence of multi-drug resistance among unusual species of enterococci posing a serious therapeutic challenge. Precise identification of enterococci to species level enables us to access the species-specific antimicrobial resistance characteristics, apart from knowing the epidemiological pattern and their clinical significance in human infections.

Parallel Evolution of High-Level Aminoglycoside Resistance in Escherichia coli Under Low and High Mutation Supply Rates

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Claudia Ibacache-Quiroga

2018-03-01

Full Text Available Antibiotic resistance is a major concern in public health worldwide, thus there is much interest in characterizing the mutational pathways through which susceptible bacteria evolve resistance. Here we use experimental evolution to explore the mutational pathways toward aminoglycoside resistance, using gentamicin as a model, under low and high mutation supply rates. Our results show that both normo and hypermutable strains of Escherichia coli are able to develop resistance to drug dosages > 1,000-fold higher than the minimal inhibitory concentration for their ancestors. Interestingly, such level of resistance was often associated with changes in susceptibility to other antibiotics, most prominently with increased resistance to fosfomycin. Whole-genome sequencing revealed that all resistant derivatives presented diverse mutations in five common genetic elements: fhuA, fusA and the atpIBEFHAGDC, cyoABCDE, and potABCD operons. Despite the large number of mutations acquired, hypermutable strains did not pay, apparently, fitness cost. In contrast to recent studies, we found that the mutation supply rate mainly affected the speed (tempo but not the pattern (mode of evolution: both backgrounds acquired the mutations in the same order, although the hypermutator strain did it faster. This observation is compatible with the adaptive landscape for high-level gentamicin resistance being relatively smooth, with few local maxima; which might be a common feature among antibiotics for which resistance involves multiple loci.

Antibiotic Resistance Patterns of Enterococci and Occurrence of Vancomycin-Resistant Enterococci in Raw Minced Beef and Pork in Germany

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Klein, Günter; Pack, Alexander; Reuter, Gerhard

1998-01-01

The food chain, especially raw minced meat, is thought to be responsible for an increase in the incidence of vancomycin-resistant enterococci (VRE) in human nosocomial infections. Therefore, 555 samples from 115 batches of minced beef and pork from a European Union-licensed meat-processing plant were screened for the occurrence of VRE. The processed meat came from 45 different slaughterhouses in Germany. Enterococci were isolated directly from Enterococcosel selective agar plates and also from Enterococcosel selective agar plates supplemented with 32 mg of vancomycin per liter. In addition, peptone broth was used in a preenrichment procedure, and samples were subsequently plated onto Enterococcosel agar containing vancomycin. To determine resistance, 209 isolates from 275 samples were tested with the glycopeptides vancomycin, teicoplanin, and avoparcin and 19 other antimicrobial substances by using a broth microdilution test. When the direct method was used, VRE were found in 3 of 555 samples (0.5%) at a concentration of 1.0 log CFU/g of minced meat. When the preenrichment procedure was used, 8% of the samples were VRE positive. Our findings indicate that there is a low incidence of VRE in minced meat in Germany. In addition, the resistance patterns of the VRE isolates obtained were different from the resistance patterns of clinical isolates. A connection between the occurrence of VRE in minced meat and nosocomial infections could not be demonstrated on the basis of our findings. PMID:9572958

Effect of in-feed administration of tylosin phosphate on antibiotic resistance in enterococci isolated from feedlot steers

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Alicia G Beukers

2015-05-01

Full Text Available Tylosin phosphate is a macrolide commonly administered to cattle in North America for the control of liver abscesses. This study investigated the effect of in-feed administration of tylosin phosphate to cattle at subtherapeutic levels and its subsequent withdrawal on macrolide resistance using enterococci as an indicator bacterium. Faecal samples were collected from steers that received no antibiotics and steers administered tylosin phosphate (11 ppm in-feed for 197 d and withdrawn 28 d before slaughter. Enterococcus species isolated from faecal samples were identified through sequencing the groES-EL intergenic spacer region and subject to antimicrobial susceptibility testing, identification of resistance determinants and pulsed-field gel electrophoresis profiling. Tylosin increased (P 0.05 between treatments on d 225. This suggests that antibiotic withdrawal prior to slaughter contributes to a reduction in the proportion of macrolide resistant enterococci entering the food chain. Among the 504 enterococci isolates characterised, E. hirae was found to predominate (n=431, followed by E. villorum (n=32, E. faecium (n=21, E. durans (n=7, E. casseliflavus (n=4, E. mundtii (n=4, E. gallinarum (n=3, E. faecalis (n=1, and E. thailandicus (n=1. The diversity of enterococci was greater in steers at arrival than at exit from the feedlot. Erythromycin resistant isolates harboured the erm(B and/or msrC gene. Similar PFGE profiles of eryR E. hirae n pre- and post-antibiotic treatment suggests the increased abundance of eryR enterococci after administration of tylosin phosphate reflects selection for strains that were within the bovine gastrointestinal tract of cattle at arrival.

Frequency of antiseptic resistance genes in clinical staphycocci and enterococci isolates in Turkey

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Seyda Ignak

2017-08-01

Full Text Available Abstract Background Disinfectants and antiseptics are biocides widely used in hospitals to prevent spread of pathogens. It has been reported that antiseptic resistance genes, qac’s, caused tolerance to a variety of biocidal agents, such as benzalkonium chloride (BAC and chlorhexidine digluconate (CHDG in Staphylococcus spp. isolates. We aimed to search the frequency of antiseptic resistance genes in clinical Staphylococcus spp. and Enterococcus spp. isolates to investigate the possible association with antiseptic tolerance and antibiotic resistance. Methods Antiseptic resistance genes (qacA/B, smr, qacG, qacH, and qacJ isolated from Gram-positive cocci (69 Staphylococcus spp. and 69 Enterococcus spp. were analyzed by PCR method. The minimum inhibitory concentrations (MICs of BAC and CHDG were determined by agar dilution method, whereas antibiotic susceptibility was analyzed by disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI criteria. Results The frequency of antiseptic resistance genes was found to be high (49/69; 71.0% in our clinical staphylococci isolates but absent (0/69; 0% in enterococci isolates. The frequency of qacA/B and smr genes was higher (25/40; 62.5% and 7/40; 17.5%, respectively in coagulase negative staphylococci (CNS when compared to Staphylococcus aureus strains (3/29; 10.3%, and 4/29; 13.8%, respectively. In contrast, the frequency of qacG and qacJ genes was higher (11/29; 37.9% and 8/29; 27.5%, respectively in S. aureus than those of CNS (5/40; 12.5%, 10/40; 25.0% strains. qacH was not identified in none of the strains. We found an association between presence of antiseptic resistance genes and increased MIC values of BAC (>4 μg/mL in staphylococci and it was found to be statistically statistically significant (p < 0.01. We also showed that MICs of BAC and CHDG of vancomycin-resistant enterococci (VRE isolates were significantly higher than those of vancomycin

Antimicrobial Susceptibility Pattern of Enterococci Isolated From Patients in Tehran

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Horieh Saderi

2015-11-01

Full Text Available Background: Enterococci are one of the most common nosocomial pathogens and the emergence of multidrug-resistant strains has been increasing. Objectives: We studied the antimicrobial susceptibility of enterococci isolated from different clinical specimens of patients in Tehran. Materials and Methods: From the beginning of April 2013 to the end of June 2013, a total of 146 enterococci were isolated from the Pars General Hospital in Tehran. The antimicrobial susceptibility pattern of the isolates against ampicillin, clindamaycin, ciprofloxacin, erythromycin, levofloxacin, linezolid, nitrofurantoin, tetracycline, and vancomycin was determined using the disk diffusion method according to the guidelines of clinical laboratory standards institute (CLSI. Results: The rates of resistance were high to clindamycin, tetracycline, and erythromycin (97.2%, 89%, and 74.5%, respectively; moderate to ciprofloxacilin and levofloxacilin (40.6% and 36.4%, respectively; and low to ampicillin and nitrofurantoin (13.8% and 3.5%, respectively. All isolates were linezolid sensitive. Vancomycin-resistant enterococci (VRE accounted for 9.6% of the isolates. Conclusions: VRE and a high rate of resistance to some of antimicrobial agents were found among the enterococci isolated from patients in Tehran. These findings highlight the importance of regular supervision of antimicrobial susceptibilities.

Comparison of antimicrobial resistance patterns in enterococci from intensive and free range chickens in Australia.

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Obeng, Akua Serwaah; Rickard, Heather; Ndi, Olasumbo; Sexton, Margaret; Barton, Mary

2013-02-01

Resistance to antimicrobials in enterococci from poultry has been found throughout the world and is generally recognized as associated with antimicrobial use. This study was conducted to evaluate the phenotypic and genotypic profile of enterococcal isolates of intensive (indoor) and free range chickens from 2008/09 and 2000 in order to determine the patterns of antimicrobial resistance associated with different management systems. The minimum inhibitory concentrations in faecal enterococci isolates were determined by agar dilution. Resistance to bacitracin, ceftiofur, erythromycin, lincomycin, tylosin and tetracycline was more common among meat chickens (free range and intensive) than free range egg layers (Pfree range meat chickens.

Avaliação da sensibilidade a antimicrobianos de 87 amostras clínicas de enterococos resistentes à vancomicina Antimicrobial susceptibility testing of 87 clinical isolates of vancomycin-resistant enterococci

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I.H. Saraiva

1997-09-01

tratamento de infecções causadas por enterococos multirresistentes ainda é um desafio, e vários esquemas já vêm sendo propostos na literatura. São necessários, no entanto, mais trabalhos analisando a efetividade clínica dessas combinações de antibióticos antes que recomendações definitivas possam ser feitas.OBJECTIVES. 1 To evaluate the antimicrobial susceptibility pattern of vancomycin-resistant enterococci to the antimicrobial agents that are commonly used to treat enterococci infections and to some alternative drugs. 2 To evaluate the accuracy of E test for susceptibility testing enterococci. MATERIAL AND METHOD. We evaluated 87 clinical VRE isolates that were selected from a previous study which analyzed 1936 clinical isolates collected and processed in 97 US medical centers in the last quarter of 1992. The isolates were identified to the species level by using the API 20S System, the Vitek gram-positive identification cards and a modified version of the conventional method proposed by Facklam and Collins. The in vitro susceptibility testing was performed by broth microdilution, E test and disk diffusion methods, following the criteria described by the National Committee for Clinical Laboratory Standards (NCCLS. The VRE isolates were tested against antimicrobial agents commonly used to treat enterococci infections (vancomycin, teicoplanin, ampicillin, penicillin, gentamicin and streptomycin and against ten potential alternative drugs (chloramphenicol, doxycycline, sparfloxacin, ciprofloxacin, clinafloxacin, erythromycin, spectinomycin, trospectomycin, trimetoprim-sulfametoxazol and novobiocin. RESULTS. Our results showed a high rate of resistance to ampicillin and penicillin (86%. High level resistance to gentamicin and streptomycin was demonstrated by 82% and 85% respectively. Although teicoplanin and vancomycin belong to the same antibiotic group (glycopeptide, 29% of VRE were susceptible to teicoplanin. Among the alternative drugs, trospectomycin

Sewage sludge and liquid pig manure as possible sources of antibiotic resistant bacteria.

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Hölzel, Christina S; Schwaiger, Karin; Harms, Katrin; Küchenhoff, Helmut; Kunz, Anne; Meyer, Karsten; Müller, Christa; Bauer, Johann

2010-05-01

Within the last decades, the environmental spread of antibiotic resistant bacteria has become a topic of concern. In this study, liquid pig manure (n=305) and sewage sludge (n=111) - used as agricultural fertilizers between 2002 and 2005 - were investigated for the presence of Escherichia coli, Enterococcus faecalis and Enterococcus faecium. Bacteria were tested for their resistance against 40 chemotherapeutics including several "reserve drugs". E. coli (n=613) from pig manure were at a significantly higher degree resistant to streptomycin, doxycycline, spectinomycin, cotrimoxazole, and chloramphenicol than E. coli (n=116) from sewage sludge. Enterococci (Ent. faecalis, n=387, and Ent. faecium, n=183) from pig manure were significantly more often resistant to high levels of doxycycline, rifampicin, erythromycin, and streptomycin than Ent. faecalis (n=44) and Ent. faecium (n=125) from sewage sludge. Significant differences in enterococcal resistance were also seen for tylosin, chloramphenicol, gentamicin high level, fosfomycin, clindamicin, enrofloxacin, moxifloxacin, nitrofurantoin, and quinupristin/dalfopristin. By contrast, aminopenicillins were more effective in enterococci from pig manure, and mean MIC-values of piperacillin+tazobactam and third generation cefalosporines were significantly lower in E. coli from pig manure than in E. coli from sewage sludge. 13.4% (E. coli) to 25.3% (Ent. faecium) of pig manure isolates were high-level multiresistant to substances from more than three different classes of antimicrobial agents. In sewage sludge, high-level-multiresistance reached from 0% (Ent. faecalis) to 16% (Ent. faecium). High rates of (multi-) resistant bacteria in pig manure emphasize the need for a prudent - cautious - use of antibiotics in farm animals. Copyright 2010 Elsevier Inc. All rights reserved.

Novel pathways for ameliorating the fitness cost of gentamicin resistant small colony variants

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Vestergaard, Martin; Paulander, Wilhelm Erik Axel; Leng, Bingfeng

2016-01-01

Small colony variants (SCVs) of the human pathogen Staphylococcus aureus are associated with persistent infections. Phenotypically, SCVs are characterized by slow growth and they can arise upon interruption of the electron transport chain that consequently reduce membrane potential and thereby...... limit uptake of aminoglycosides (e.g., gentamicin). In this study, we have examined the pathways by which the fitness cost of SCVs can be ameliorated. Five gentamicin resistant SCVs derived from S. aureus JE2 were independently selected on agar plates supplemented with gentamicin. The SCVs carried...... mutations in the menaquinone and hemin biosynthesis pathways, which caused a significant reduction in exponential growth rates relative to wild type (WT; 0.59-0.72) and reduced membrane potentials. Fifty independent lineages of the low-fitness, resistant mutants were serially passaged for up to 500...

Intramammary treatment with gentamicin in lactating cows with clinical and subclinical mastitis

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Thamires Martins

2016-04-01

Full Text Available Abstract The study evaluated the microbiological profile of milk samples collected before and after mastitis treatment with gentamicin and investigated biofilms production and antimicrobial susceptibility of Staphylococcus spp. isolated. The presence of gentamicin residues in milk after the recommended withdrawal period was also evaluated. Antimicrobial residues were analyzed by Delvotest® SP NT over a period of 12 days beginning after 24 hours the last gentamicin application. Some of Staphylococcus spp. isolates were biofilm producers (19.05%. Staphylococcus spp. showed high levels of resistance to neomycin (16.95%, penicillin G (10.17%, and ampicillin (10.17%. Multidrug resistance to all antibiotics tested was observed in 1.69% of the Staphylococcus spp. isolates. Among 1440 mammary quarter milk samples 24.95% presented gentamicin residues after the withdrawal period. Gentamicin residues were also detected in 3.8% of samples from calibrated glass recorder jar (n=383 4.1 days after treatment. The indiscriminate use of antibiotics may lead to the emergence of multidrug-resistant strains as well as increasing the risk of presence of residues of these drugs in milk. These problems affect the milk quality and may become a public health problem.

Linezolid-resistant enterococci in Polish hospitals: species, clonality and determinants of linezolid resistance.

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Gawryszewska, I; Żabicka, D; Hryniewicz, W; Sadowy, E

2017-07-01

The significant increase of the linezolid-resistant enterococci (LRE) has been observed in Polish hospitals since 2012 and our study aimed at elucidating the possible reasons for this phenomenon. Polish LRE isolates were analysed by multilocus-sequence typing (MLST) and multiple locus variable-number tandem repeat (VNTR) analysis (MLVA), polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP) to establish clonal relatedness and mechanism of linezolid resistance, respectively. Fifty analysed LRE (2008-2015) included mostly Enterococcus faecium (82%) and Enterococcus faecalis (16%). Enterococcus faecium belonged to the hospital-adapted lineages 17/18 and 78, while E. faecalis isolates represented ST6, a hospital-associated type, and ST116, found in both humans and food-production animals. The G2576T 23S rRNA mutation was the most frequent (94%) mechanism of linezolid/tedizolid resistance of LRE. None of the isolates carried the plasmid-associated gene of Cfr methyltransferase, whereas optrA, encoding the ABC-type drug transporter, was identified in two E. faecalis isolates. In these isolates, optrA was located on a plasmid, transferable to both E. faecium and E. faecalis, whose partial (36.3 kb) sequence was 100% identical to the pE394 plasmid, identified previously in China in both clinical and farm animal isolates. The optrA-E. faecium transconjugant displayed a significant growth deficiency, in contrast to the optrA-E. faecalis. Our study indicates the role of mutation acquisition by hospital-adapted clones of enterococci as a major driver of increasing resistance to linezolid and tedizolid. Transferability and apparent lack of a biological cost of resistance suggest that E. faecalis may be a natural reservoir of optrA, an emerging mechanism of oxazolidinone resistance.

Patrones de resistencia a antibióticos de enterococos aislados de aguas estuarinas Antibiotic resistance patterns of enterococci isolated from estuarine waters

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M. Baldini

2008-03-01

30 µg, ampicillin (Am 10 µg and ciprofloxacin (CIP 5 µg according to the Clinical and Laboratory Standards Institute. Seven Enterococcus species were identified, being Enterococcus faecium and Enterococcus faecalis the most frequent. High level resistance to aminoglycosides was shown by 1.9% of the enterococci whereas 12.6% of the isolates were resistant to CIP. No isolates showed simultaneous resistance to StrH and GenH. Neither resistance to glycopeptides nor to Am was detected. Thirty four per cent of the isolates exhibited susceptibility to all antibiotics tested. Surveillance studies on antimicrobial resistance are usually based upon microorganisms isolated from clinical samples. The findings of this work constitute relevant data for the control of resistant strains, which were believed to be circumscribed to the hospital environment, but are also widespread in the natural sites.

Occurrence of antibiotic resistance genes and mobile genetic elements in enterococci and genomic DNA during anaerobic digestion of pharmaceutical waste sludge with different pretreatments.

Science.gov (United States)

Tong, Juan; Lu, XueTing; Zhang, JunYa; Sui, Qianwen; Wang, Rui; Chen, Meixue; Wei, Yuansong

2017-07-01

Pharmaceutical waste sludge harbors large amounts of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs), and it is necessary to study the reduction of ARGs and MGEs during sludge treatment. Therefore, the antibiotic resistance phenotypes and genotypes of enterococci, and the ARGs and MGEs in genomic DNA were investigated during anaerobic digestion (AD) with microwave (MW), thermal hydrolysis (TH) and ozone pretreatment. Results showed that sludge pretreatment increased the occurrence of the resistance phenotypes and genotypes of enterococci. During AD, the resistance of enterococci to macrolides decreased, except for in the MW-pretreated sludge. Horizontal gene transfer and co-occurrence of ermB and tetM in enterococci resulted in increased tetracycline resistance of enterococci throughout the sludge treatment. MGEs such as intI1, ISCR1 and Tn916/1545 had a significant effect on the distribution of ARGs. AD with pretreatment, especially TH pretreatment, resulted in greater ARGs and MGEs reduction and improved methane production. Copyright © 2017. Published by Elsevier Ltd.

Gentamicin release from commercially-available gentamicin-loaded PMMA bone cements in a prosthesis-related interfacial gap model and their antibacterial efficacy

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van der Mei Henny C

2010-11-01

Full Text Available Abstract Background Around about 1970, a gentamicin-loaded poly (methylmethacrylate (PMMA bone cement brand (Refobacin Palacos R was introduced to control infection in joint arthroplasties. In 2005, this brand was replaced by two gentamicin-loaded follow-up brands, Refobacin Bone Cement R and Palacos R + G. In addition, another gentamicin-loaded cement brand, SmartSet GHV, was introduced in Europe in 2003. In the present study, we investigated differences in gentamicin release and the antibacterial efficacy of the eluent between these four cement brands. Methods 200 μm-wide gaps were made in samples of each cement and filled with buffer in order to measure the gentamicin release. Release kinetics were related to bone cement powder particle characteristics and wettabilities of the cement surfaces. Gaps were also inoculated with bacteria isolated from infected prostheses for 24 h and their survival determined. Gentamicin release and bacterial survival were statistically analysed using the Student's t-test. Results All three Palacos variants showed equal burst releases but each of the successor Palacos cements showed significantly higher sustained releases. SmartSet GHV showed a significantly higher burst release, while its sustained release was comparable with original Palacos. A gentamicin-sensitive bacterium did not survive in the high gentamicin concentrations in the interfacial gaps, while a gentamicin-resistant strain did, regardless of the type of cement used. Survival was independent of the level of burst release by the bone cement. Conclusions Although marketed as the original gentamicin-loaded Palacos cement, orthopaedic surgeons should be aware that the successor cements do not appear to have the same release characteristics as the original one. Overall, high gentamicin concentrations were reached inside our prosthesis-related interfacial gap model. These concentrations may be expected to effectively decontaminate the prosthesis

The potential of vancomycin-resistant enterococci to persist in fermented and pasteurised meat products.

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Houben, J H

2003-11-15

Experiments with 148 isolates of vancomycin-resistant enterococci (VRE) were performed to assess their potential to persist and grow in fermented sausages and pasteurised meat products. All strains were meat isolates and Van-type A, except a single VanC1 strain. In total, 143 strains of Enterococcus faecium were involved. Eight selected strains were examined for their potential to grow at high salt and nitrite levels and at reduced pH. The same isolates were used in experiments with fermented sausages. All available strains were subjected to heating tests in meat suspensions with added curing ingredients. All but one of the eight tested isolates grew at pH 4.0 in tryptone soya broth (TSB). With the combination of 8% w/w NaCl, 400 ppm NaNO2 and 0.5% w/w glucose in the meat suspension, all isolates grew at 37 degrees C, whereas none grew at 7 degrees C even after 56 days. With the addition of 10% w/w NaCl, 200 ppm NaNO2 and 0.5% w/w glucose, still one E. faecium isolate grew at 37 degrees C, although very slowly. Overall, the strains tolerated high salt and nitrite concentrations and reduced pH very well, even beyond levels applied in the regular production of fermented and/or pasteurised meat products. The tested strains could be isolated after the fermentation and further ripening of "boerenmetworst" and "snijworst". Overall, their colony counts decreased on average about 1 log-unit over a period of 60 days after batter manufacture. All 148 isolates demonstrated a relatively weak thermal resistance compared to results for selected vancomycin-sensitive enterococci strains reported in the literature and to results collected under identical experimental conditions in this laboratory. None of the strains (log inoculation level about 5-6 ml(-1) for each isolate) could be cultured after heating at 70 degrees C for 10 min.

Sublethal Triclosan Exposure Decreases Susceptibility to Gentamicin and Other Aminoglycosides in Listeria monocytogenes

DEFF Research Database (Denmark)

Christensen, Ellen Gerd; Gram, Lone; Kastbjerg, Vicky Gaedt

2011-01-01

(containing quaternary ammonium compound) in four consecutive cultures did not alter the frequency of antibiotic-tolerant isolates, as determined by plating on 2x the MIC for a range of antibiotics. Exposure of eight strains of L. monocytogenes to 1 and 4 µg/ml triclosan did not alter triclosan sensitivity...... resistance remained at a high level also after five subcultures without triclosan or gentamicin. Aminoglycoside resistance can be caused by mutations in the target site, the 16S rRNA gene. However, such mutations were not detected in the N53-1-resistant isolates. A combination of gentamicin and ampicillin...

In vitro synergy of baicalein and gentamicin against vancomycin-resistant Enterococcus.

Science.gov (United States)

Chang, Ping Chin; Li, Hua Yu; Tang, Hung Jen; Liu, Jien Wei; Wang, Jhi Joung; Chuang, Yin Ching

2007-02-01

Little is known about the possible synergism of baicalein, a bioactive flavone of Scutellariae radix (a Chinese herb), when used in conjunction with other antimicrobial agents against vancomycin-resistant Enterococcus (VRE). This in vitro study examined the possible synergism of the combination of baicalein and gentamicin against VRE. Minimal inhibitory concentrations (MICs) of baicalein as well as gentamicin were determined against 39 clinical isolates of VRE by the agar dilution method. Synergistic activities were determined using the checkerboard method based on the fractional inhibitory concentration indices and also the time-kill method. Further time-kill studies were conducted with these two agents against one randomly chosen clinical isolate, VRE-096. Minimal concentrations inhibiting 50% (MIC(50)) and 90% (MIC(90)) of isolates for baicalein and gentamicin were all >256 microg/mL. Synergism between baicalein and gentamicin was demonstrated against four clinical isolates of VRE (VRE-70, VRE-940, VRE-096 and VRE-721). When approximately 5 x 10(5) colony-forming units/mL of VRE-096 was incubated with both baicalein at a concentration of 32 microg/mL (1/8 x MIC) and gentamicin at a concentration of 128 microg/mL (1/2 x MIC), there was an inhibitory effect against VRE that persisted for 48 h. At 48 h, the combination of baicalein and gentamicin at these respective concentrations resulted in a reduction of growth by approximately 2 orders of magnitude compared to that for the starting inoculum and by 3 orders of magnitude compared to that for baicalein alone, the more active single agent. This study demonstrated that baicalein and gentamicin can act synergistically in inhibiting VRE in vitro.

In vitro antimicrobial activity of linezolid tested against vancomycin-resistant enterococci isolated in Brazilian hospitals

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Reis Adriana O.

2001-01-01

Full Text Available The emergence of vancomycin-resistant enterococci (VRE has been described recently in Brazil. This is in contrast to the USA and Europe, where the VRE appeared in the late 1980s. The progressive increase in VRE isolation poses important problems in the antimicrobial therapy of nosocomial infections. Treatment options and effective antimicrobial agents for VRE are often limited and the possibility of transfer of vancomycin genes to other Gram-positive microorganisms continues. In the search for antimicrobial agents for multiresistant Gram-positive cocci, compounds such as linezolid and quinupristin/dalfopristin have been evaluated. The present study was conducted to evaluate the in vitro activity of the oxazolidinone linezolid and 10 other antimicrobial agents, including quinupristin-dalfopristin, against multiresistant enterococci isolated in Brazilian hospitals. Thirty-three vancomycin resistant isolates (17 Enterococcus faecium and 16 E. faecalis, were analyzed. Strains were isolated from patients at São Paulo Hospital, Oswaldo Cruz Hospital, Hospital do Servidor Público Estadual, Santa Marcelina Hospital, Santa Casa de Misericórdia de São Paulo, and Hospital de Clínicas do Paraná. The samples were tested by a broth microdilution method following the National Committee for Clinical Laboratory Standards (NCCLS recommendations. All isolates were molecular typed using pulsed-field gel electrophoresis (PFGE. Linezolid was the most active compound against these multiresistant enterococci, showing 100% inhibition at the susceptible breakpoints. Quinupristin/dalfopristin and teicoplanin showed poor activity against both species. The molecular typing results suggest that there has been interhospital spread of vancomycin resistant E. faecium and E. faecalis among Brazilian hospitals. The results of this study indicate that linezolid is an appropriate therapeutic option for the treatment of vancomycin-resistant enterococci infections in Brazil.

The Role of Monitoring Gentamicin Levels in Patients with Gram-Negative Peritoneal Dialysis-Associated Peritonitis

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Tang, Wen; Cho, Yeoungjee; Hawley, Carmel M.; Badve, Sunil V.; Johnson, David W.

2014-01-01

♦ Background: There is limited available evidence regarding the role of monitoring serum gentamicin concentrations in peritoneal dialysis (PD) patients receiving this antimicrobial agent in gram-negative PD-associated peritonitis. ♦ Methods: Using data collected in all patients receiving PD at a single center who experienced a gram-negative peritonitis episode between 1 January 2005 and 31 December 2011, we investigated the relationship between measured serum gentamicin levels on day 2 following initial empiric antibiotic therapy and subsequent clinical outcomes of confirmed gram-negative peritonitis. ♦ Results: Serum gentamicin levels were performed on day 2 in 51 (77%) of 66 first gram-negative peritonitis episodes. Average serum gentamicin levels on day 2 were 1.83 ± 0.84 mg/L with levels exceeding 2 mg/L in 22 (43%) cases. The overall cure rate was 64%. No cases of ototoxicity were observed. Day-2 gentamicin levels were not significantly different between patients who did and did not have a complication or cure. Using multivariable logistic regression analysis, failure to cure peritonitis was not associated with either day-2 gentamicin level (adjusted odds ratio (OR) 0.96, 95% confidence interval (CI) 0.25 - 3.73) or continuation of gentamicin therapy beyond day 2 (OR 0.28, 0.02 - 3.56). The only exception was polymicrobial peritonitis, where day-2 gentamicin levels were significantly higher in episodes that were cured (2.06 ± 0.41 vs 1.29 ± 0.71, p = 0.01). In 17 (26%) patients receiving extended gentamicin therapy, day-5 gentamicin levels were not significantly related to peritonitis cure. ♦ Conclusion: Day-2 gentamicin levels did not predict gentamicin-related harm or efficacy during short-course gentamicin therapy for gram-negative PD-related peritonitis, except in cases of polymicrobial peritonitis, where higher levels were associated with cure. PMID:24385334

Enterocin A mutants identified by saturation mutagenesis enhance potency towards vancomycin-resistant Enterococci.

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McClintock, Maria K; Kaznessis, Yiannis N; Hackel, Benjamin J

2016-02-01

Vancomycin-resistant Enterococci infections are a significant clinical problem. One proposed solution is to use probiotics, such as lactic acid bacteria, to produce antimicrobial peptides at the site of infection. Enterocin A, a class 2a bacteriocin, exhibits inhibitory activity against E. faecium and E. faecalis, which account for 86% of vancomycin-resistant Enterococci infections. In this study, we aimed to engineer enterocin A mutants with enhanced potency within a lactic acid bacterial production system. Peptide mutants resulting from saturation mutagenesis at sites A24 and T27 were efficiently screened in a 96-well plate assay for inhibition of pathogen growth. Several mutants exhibit increased potency relative to wild-type enterocin A in both liquid- and solid-medium growth assays. In particular, A24P and T27G exhibit enhanced inhibition of multiple strains of E. faecium and E. faecalis, including clinically isolated vancomycin-resistant strains. A24P and T27G enhance killing of E. faecium 8 by 13 ± 3- and 18 ± 4-fold, respectively. The engineered enterocin A/lactic acid bacteria systems offer significant potential to combat antibiotic-resistant infections. © 2015 Wiley Periodicals, Inc.

Nurses' experience with vancomycin-resistant enterococci (VRE).

Science.gov (United States)

Mitchell, Ann; Cummins, Teresa; Spearing, Natalie; Adams, June; Gilroy, Lisa

2002-01-01

The emergence and spread of resistant organisms, in particular vancomycin-resistant enterococci (VRE), is an issue facing all staff in acute hospitals. This study explored how nurses coped with the responsibility of halting further spread of this organism during an outbreak. VRE-positive patients were cohorted with nurses who cared for them in an endeavour to contain the spread of VRE. The majority of nurses found the situation extremely stressful because of the need to act as 'gatekeepers' responsible for educating and monitoring the practices of staff and visitors. The nurses reported that they felt they were inadequately supported, were blamed for the outbreak, and that they had an increased workload as they took on duties of other staff. The results reinforce the need for a multidisciplinary team approach to education and control of VRE, more support for nursing staff cohorted with VRE-positive patients, and stringent adherence to infection control measures by all hospital staff.

Vancomycin-resistant enterococci (VRE) in broiler flocks 5 years after the avoparcin ban

DEFF Research Database (Denmark)

Heuer, Ole Eske; Pedersen, Karl; Andersen, J.S.

2002-01-01

The glycopeptide growth promoter avoparcin was banned from animal production in Denmark in 1995. In this study, we investigated the occurrence of vancomycin-resistant enterococci (VRE) in broiler flocks in the absence of the selective pressure exerted by the use of avoparcin. One hundred sixty...

Wounds, Functional Disability, and Indwelling Devices Are Associated With Cocolonization by Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci in Southeast Michigan

OpenAIRE

Flannery, Erika L.; Wang, Linda; Zöllner, Sebastian; Foxman, Betsy; Mobley, Harry L. T.; Mody, Lona

2011-01-01

Cocolonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) is a precursor to vancomycin-resistant S. aureus emergence. MRSA/VRE cocolonization incidence is higher among skilled nursing facility residents with functional disability and indwelling devices and occurs more frequently in wounds than other anatomical sites.

Prevalence and Removal Efficiency of Enterococcal Species and Vancomycin-resistant Enterococci of a Hospital Wastewater Treatment Plant

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Fatemeh Karimi

2016-12-01

Full Text Available Simultaneous presence of various antibiotics and bacteria in hospital wastewaters creates a suitable environment, in which the bacteria, such as ‎enterococci become resistant to the antibiotics. The aim of this study was to evaluate the performance of different units of the hospital wastewater treatment plant (HWTP to remove Enterococcus spp and Vancomycin-resistant Enterococcus (VRE. The study was performed on the 27 samples collected from HWTP in Hamedan, Iran during December 2014 to August 2015. Enterococcus spp and VRE were identified by biochemical tests and then the isolates were confirmed by PCR. Finally, the antibiotic susceptibility test was performed using disk diffusion methods. Of the 27 samples examined, 315 a total of enterococcal isolates were obtained. Of the 315 isolates of enterococci investigated, 162 (51.42% were identified as E. faecium, 87 (27.61% as E. hirae, 35 (11.11% as E. faecalis, 11 (3.5% as E. gallinarum, 7 (2.22% as E. casseliflavus, 4 (1.26% E. avium, and 9 (2.85% isolates VR E. faecium.The results of antibiotic susceptibility testing showed that of the total 315 isolates, 146 (46.34% were resistance to tetracycline, 9 (2.85% were resistance to vancomycin and Teicoplanin. Lower antibiotic resistance was seen with Nitrofurantoin 2 (1.26%. This study indicates a high prevalence of multidrug resistance among E. faecium isolated from HWTP, thus, it could be considered as a threat to the health and safety of ‎wastewater workers and even public health.

Annual Surveillance Summary: Vancomycin-Resistant Enterococci (VRE) Infections in the Military Health System (MHS), 2015

Science.gov (United States)

2017-03-01

Oregon, Washington, Idaho, Montana, Wyoming, Colorado, New Mexico , Arizona, Utah, Nevada, Alaska, Hawaii. • South: Texas, Oklahoma, Arkansas, Louisiana... Diabetes and Digestive and Kidney Diseases. Washington, DC. 2007; 587–620. 27. Milburn E, Chukwuma U. Vancomycin-resistant Enterococci infections in

A simple high-dose gentamicin regimen showed no side effects among neonates

DEFF Research Database (Denmark)

Blaabjerg, Anne Sofie; Kofoed, Poul-Erik; Dalegaard, Mette Correll

2017-01-01

INTRODUCTION: Treatment of infections in neonates with gentamicin is a balance between optimising bactericidal effect and minimising adverse effects. Previously, at the Neonatal Intensive Care Unit (NICU) at Kolding Hospital, Denmark, neonates suspected of having infections were treated daily...... and 2012 and treated with gentamicin were included retrospectively in the study. Neonates with trough serum (S)-gentamicin level ≥ 2.0 mg/l before the third dose were reviewed in detail. RESULTS: In total, S-gentamicin level was measured in 253 treated neonates of whom 7% displayed elevated trough values....... Neonates elevated S...

Gentamicin in Pseudomonas aeruginosa

African Journals Online (AJOL)

infections by Ps. aeruginosa is contra-indicated. In our study only 2,3 % of the Ps. aeruginosa strains were resistant to gentamicin (MIC 25 Ilg/ml). In view of the synergy reported for combined gentamicin and carbeni- cillin therapy," a combination of these two drugs may be recommended in the treatment of all Pseudomonas.

Investigation of Linezolid Resistance in Staphylococci and Enterococci

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Gallegos, Michael; Alspaugh, Debbie

2016-01-01

The objective of this study was to investigate an apparent increase in linezolid-nonsusceptible staphylococci and enterococci following a laboratory change in antimicrobial susceptibility testing from disk diffusion to an automated susceptibility testing system. Isolates with nonsusceptible results (n = 27) from Vitek2 were subjected to a battery of confirmatory testing which included disk diffusion, Microscan broth microdilution, Clinical and Laboratory Standards Institute (CLSI) reference broth microdilution, gradient diffusion (Etest), 23S rRNA gene sequencing, and cfr PCR. Our results show that there is poor correlation between methods and that only 70 to 75% of isolates were confirmed as linezolid resistant with alternative phenotypic testing methods (disk diffusion, Microscan broth microdilution, CLSI broth microdilution, and Etest). 23S rRNA gene sequencing identified mutations previously associated with linezolid resistance in 16 (59.3%) isolates, and the cfr gene was detected in 3 (11.1%) isolates. Mutations located at positions 2576 and 2534 of the 23S rRNA gene were most common. In addition, two previously undescribed variants (at positions 2083 and 2345 of the 23S rRNA gene) were also identified and may contribute to linezolid resistance. PMID:26935728

Molecular analysis of diverse elements mediating VanA glycopeptide resistance in enterococci

DEFF Research Database (Denmark)

Palepou, M.F.I.; Adebiyi, A.M.A.; Tremlett, C.H.

1998-01-01

Differences were examined among 24 distinct elements mediating VanA-type glycopeptide resistance in enterococci isolated from hospital patients and non-human sources in the UK. The methods used included long-PCR restriction fragment length polymorphism (L-PCR RFLP) analysis and DNA hybridization...... characterized by the presence of an IS1216V/IS3-like/orf1 complex and a point mutation in vanX, both of which were absent from the other 23 groups of VanA elements. This finding is consistent with the dissemination of a stable resistance element. We conclude that L-PCR RFLP analysis, combined with DNA...

First detection of the staphylococcal trimethoprim resistance gene dfrK and the dfrK-carrying transposon Tn559 in enterococci.

Science.gov (United States)

López, María; Kadlec, Kristina; Schwarz, Stefan; Torres, Carmen

2012-02-01

The trimethoprim resistance gene dfrK has been recently described in Staphylococcus aureus, but so far has not been found in other bacteria. A total of 166 enterococci of different species (E. faecium, E. faecalis, E. hirae, E. durans, E. gallinarum, and E. casseliflavus) and origins (food, clinical diseases in humans, healthy humans or animals, and sewage) were studied for their susceptibility to trimethoprim as determined by agar dilution (European Committee on Antimicrobial Susceptibility Testing) and the presence of (a) the dfrK gene and its genetic environment and (b) other dfr genes. The dfrK gene was detected in 49% of the enterococci (64% and 42% of isolates with minimum inhibitory concentrations of ≥2 mg/L or ≤1 mg/L, respectively). The tet(L)-dfrK linkage was detected in 21% of dfrK-positive enterococci. The chromosomal location of the dfrK gene was identified in one E. faecium isolate in which the dfrK was not linked to tet(L) gene but was part of a Tn559 element, which was integrated in the chromosomal radC gene. This Tn559 element was also found in 14 additional isolates. All combinations of dfr genes were detected among the isolates tested (dfrK, dfrG, dfrF, dfrK+dfrG, dfrK+dfrF, dfrF+dfrG, and dfrF+dfrG+dfrK). The gene dfrK gene was found together with other dfr genes in 58% of the tested enterococci. This study suggested an exchange of the trimethoprim resistance gene dfrK between enterococci and staphylococci, as previously observed for the trimethoprim resistance gene dfrG.

Epidemiology and ecology of enterococci, with special reference to antibiotic resistant strains, in animals, humans and the environment - Example of an ongoing project within the European research programme

DEFF Research Database (Denmark)

Kuhn, I.; Iversen, A.; Burman, L. G.

2000-01-01

The objectives of the present study are to generate knowledge of the ecology and epidemiology of enterococci in the food chain by studying the following: (1) the population structure (in measures of abundance, number of vancomycin resistant strains, antibiotic resistance patterns, diversity...... of enterococci and (4) the diversity of the drug resistance genes in enterococci, So far, 1578 samples have been collected from different countries within the EU (Sweden, Denmark, UK and Spain), and from different habitats (pig farms, carcasses in slaughter houses, soil, manure, water, sewage, and humans). Total...

Molecular characterization, technological properties and safety aspects of enterococci from 'Hussuwa', an African fermented sorghum product.

Science.gov (United States)

Yousif, N M K; Dawyndt, P; Abriouel, H; Wijaya, A; Schillinger, U; Vancanneyt, M; Swings, J; Dirar, H A; Holzapfel, W H; Franz, C M A P

2005-01-01

To identify enterococci from Hussuwa, a Sudanese fermented sorghum product, and determine their technological properties and safety for possible inclusion in a starter culture preparation. Twenty-two Enterococcus isolates from Hussuwa were identified as Enterococcus faecium by using phenotypic and genotypic tests such as 16S rDNA gene sequencing, RAPD-PCR and restriction fragment length polymorphism of the 16S/23S intergenic spacer region fingerprinting. Genotyping revealed that strains were not clonally related and exhibited a considerable degree of genomic diversity. Some strains possessed useful technological properties such as production of bacteriocins and H2O2 or utilization of raffinose and stachyose. None produced alpha-amylase or tannase. A safety investigation revealed that all strains were susceptible to the antibiotics ampicillin, gentamicin, chloramphenicol, tetracycline and streptomycin, but some were resistant to ciprofloxacin, erythromycin, penicillin and vancomycin. Production of biogenic amines or presence of genes encoding virulence determinants occurred in some strains. Enterococcus faecium strains are associated with fermentation of Sudanese Hussuwa. Some strains exhibited useful technological properties such as production of antimicrobial agents and fermentation of indigestible sugars, which may aid in stabilizing and improving the digestibility of the product respectively. Enterococci were shown to play a role in the fermentation of African foods. While beneficial properties of these bacteria are indicated, their presence in this food may also imply a hygienic risk as a result of antimicrobial resistances or presence of virulence determinants.

Vancomycin resistant enterococci (VRE in Swedish sewage sludge

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Aspan Anna

2009-05-01

Full Text Available Abstract Background Antimicrobial resistance is a serious threat in veterinary medicine and human healthcare. Resistance genes can spread from animals, through the food-chain, and back to humans. Sewage sludge may act as the link back from humans to animals. The main aims of this study were to investigate the occurrence of vancomycin resistant enterococci (VRE in treated sewage sludge, in a Swedish waste water treatment plant (WWTP, and to compare VRE isolates from sewage sludge with isolates from humans and chickens. Methods During a four month long study, sewage sludge was collected weekly and cultured for VRE. The VRE isolates from sewage sludge were analysed and compared to each other and to human and chicken VRE isolates by biochemical typing (PhenePlate, PFGE and antibiograms. Results Biochemical typing (PhenePlate-FS and pulsed field gel electrophoresis (PFGE revealed prevalence of specific VRE strains in sewage sludge for up to 16 weeks. No connection was found between the VRE strains isolated from sludge, chickens and humans, indicating that human VRE did not originate from Swedish chicken. Conclusion This study demonstrated widespread occurrence of VRE in sewage sludge in the studied WWTP. This implies a risk of antimicrobial resistance being spread to new farms and to the society via the environment if the sewage sludge is used on arable land.

A biodegradable gentamicin-hydroxyapatite-coating for infection prophylaxis in cementless hip prostheses

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D Neut

2015-01-01

Full Text Available A degradable, poly (lactic-co-glycolic acid (PLGA, gentamicin-loaded prophylactic coating for hydroxyapatite (HA-coated cementless hip prostheses is developed with similar antibacterial efficacy as offered by gentamicin-loaded cements for fixing traditional, cemented prostheses in bone. We describe the development pathway, from in vitro investigation of antibiotic release and antibacterial properties of this PLGA-gentamicin-HA-coating in different in vitro models to an evaluation of its efficacy in preventing implant-related infection in rabbits. Bone in-growth in the absence and presence of the coating was investigated in a canine model. The PLGA-gentamicin-HA-coating showed high-burst release, with antibacterial efficacy in agar-assays completely disappearing after 4 days, minimising risk of inducing antibiotic resistance. Gentamicin-sensitive and gentamicin-resistant staphylococci were killed by the antibiotic-loaded coating, in a simulated prosthesis-related interfacial gap. PLGA-gentamicin-HA-coatings prevented growth of bioluminescent staphylococci around a miniature-stem mounted in bacterially contaminated agar, as observed using bio-optical imaging. PLGA-gentamicin-HA-coated pins inserted in bacterially contaminated medullary canals in rabbits caused a statistically significant reduction in infection rates compared to HA-coated pins without gentamicin. Bone ingrowth to PLGA-gentamicin-HA-coated pins, in condylar defects of Beagle dogs was not impaired by the presence of the degradable, gentamicin-loaded coating. In conclusion, the PLGA-gentamicin-HA-coating constitutes an effective strategy for infection prophylaxis in cementless prostheses.

Vancomycin-Resistance Enterococci Infections in the Department of the Defense: Annual Report 2013

Science.gov (United States)

2014-08-01

str.r.:lioos, S€’ £l "r:’hi fl!’:: lil<i~lin ,:l ddc ~o.r-c.;s, !]:l:ho:>r rr:, aY. nflinttlirir~ :he !::f;, ·nod c ol ’ HO: Io ~:·rnhlir’U ;;· ;d ro...16. Morris JG, et al. Enterococci resistant to multiple antimicrobial agents, including vancomycin: establishment of endemicity in a university

Safety of gentamicin bladder irrigations in complex urological cases.

Science.gov (United States)

Defoor, William; Ferguson, Denise; Mashni, Susan; Creelman, Lisa; Reeves, Deborah; Minevich, Eugene; Reddy, Pramod; Sheldon, Curtis

2006-05-01

Recurrent urinary tract infections are common in complex pediatric urological cases, particularly those requiring clean intermittent catheterization. At our institution gentamicin bladder irrigations have been used for antimicrobial prophylaxis and to treat symptomatic bacteriuria, particularly when the infection does not involve the upper urinary tract. The purpose of this study was to assess the safety of this therapy. A retrospective study was performed of all children treated with gentamicin bladder irrigations from 1999 to 2004. The dose was 14 mg gentamicin in 30 ml saline instilled via catheter once or twice daily. Serum creatinine and random gentamicin levels were obtained according to a protocol based on risk of gentamicin toxicity. Patient demographics, laboratory results and outcomes were abstracted from the medical records. A total of 80 patients (38 males and 42 females) were identified. Median patient age was 10 years and median duration of treatment was 90 days. No patient had detectable serum gentamicin levels greater than 0.4 mg/dl. Small increases in serum creatinine were seen in 3 patients, all of whom had chronic renal insufficiency. A total of 21 patients (26%) had breakthrough UTIs, of which 5 (24%) were gentamicin resistant. No adverse events were documented. Gentamicin bladder irrigations are a helpful adjunct in the management of complex pediatric urological cases involving recurrent symptomatic bacteriuria. We no longer require intensive laboratory monitoring of low risk patients at our institution.

Occurrence of airborne vancomycin- and gentamicin-resistant bacteria in various hospital wards in Isfahan, Iran.

Science.gov (United States)

Mirhoseini, Seyed Hamed; Nikaeen, Mahnaz; Khanahmad, Hossein; Hassanzadeh, Akbar

2016-01-01

Airborne transmission of pathogenic resistant bacteria is well recognized as an important route for the acquisition of a wide range of nosocomial infections in hospitals. The aim of this study was to determine the prevalence of airborne vancomycin and gentamicin (VM and GM) resistant bacteria in different wards of four educational hospitals. A total of 64 air samples were collected from operating theater (OT), Intensive Care Unit (ICU), surgery ward, and internal medicine ward of four educational hospitals in Isfahan, Iran. Airborne culturable bacteria were collected using all glass impingers. Samples were analyzed for the detection of VM- and GM-resistant bacteria. The average level of bacteria ranged from 99 to 1079 CFU/m(3). The highest level of airborne bacteria was observed in hospital 4 (628 CFU/m(3)) and the highest average concentration of GM- and VM-resistant airborne bacteria were found in hospital 3 (22 CFU/m(3)). The mean concentration of airborne bacteria was the lowest in OT wards and GM- and VM-resistant airborne bacteria were not detected in this ward of hospitals. The highest prevalence of antibiotic-resistant airborne bacteria was observed in ICU ward. There was a statistically significant difference for the prevalence of VM-resistant bacteria between hospital wards (P = 0.012). Our finding showed that the relatively high prevalence of VM- and GM-resistant airborne bacteria in ICUs could be a great concern from the point of view of patients' health. These results confirm the necessity of application of effective control measures which significantly decrease the exposure of high-risk patients to potentially airborne nosocomial infections.

Gentamicin nephrotoxicity: Animal experimental correlate with human pharmacovigilance outcome

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Olufunsho Awodele

2015-04-01

Full Text Available Background: National Agency for Food and Drugs Administration and Control (NAFDAC, which is responsible for pharmacovigilance activity in Nigeria, recently withdrew injection gentamicin 280 mg, used in the management of life-threatening and multidrug-resistant infections from circulation, due to reported toxicity. Thus, this study aimed to investigate the toxicity profile of the commonly used strengths (80 mg and 280 mg of gentamicin on kidney using animal models. Methods: Animals were divided into five groups of 16 rats each. For rats of groups 1 and 2, gentamicin (1.14 mg/kg each group was administered intramuscularly twice daily for 7 and 14 days, respectively, after which eight of them were sacrificed by cervical dislocation. Blood was collected via cardiac puncture and the kidneys were carefully removed and weighed immediately. The remaining eight animals were kept for reversibility study for another 7 and 14 days, respectively. For groups 3 and 4, gentamicin (4 mg/kg each group was administered as a single daily dose for 7 and 14 days, respectively, and eight animals from the groups were subjected to reversibility study for 7 and 14 days, respectively. Group 5, the control group animals, were given 10 ml/kg distilled water for 14 days. Histopathology of the kidneys, serum creatinine levels, and antioxidant enzyme activities were investigated. Results: Significant increase (p ≤ 0.001 in the level of creatinine of rats administered 4.0 mg/kg for 14 days was observed compared with all other groups. Significant (p ≤ 0.001 elevations in the lipid peroxidation in all gentamicin-administered animals and acute tubular necrosis in most of the gentamicin-administered animals were observed. Conclusion: Toxicity profile of gentamicin on the kidneys is dependent on both dose and duration of administration. The findings justify the decision made by NAFDAC to ban the use of high-dose inj. gentamicin 280 mg in Nigeria.

Gentamicin pharmacokinetics in the chicken inner ear.

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Bunting, Eric C; Park, Debra L; Durham, Dianne; Girod, Douglas A

2004-06-01

Avians have the unique ability to regenerate cochlear hair cells that are lost due to ototoxins or excessive noise. Many methodological techniques are available to damage the hair cells for subsequent scientific study. A recent method utilizes topical application of an ototoxic drug to the round window membrane. The current study examines the pharmacokinetics of gentamicin in the inner ear of chickens following topical application to the round window membrane or a single systemic high dose given intraperitoneally. Chickens were given gentamicin topically or systemically and survived for 1, 4, 12, 24, or 120 h (controls at 4 and 120 h). Serum and perilymph samples were obtained prior to sacrifice and measured for gentamicin levels. Results revealed higher levels of gentamicin in the perilymph of topically treated chickens than systemically treated chickens, with significant amounts of gentamicin still present in both at the latest survival time of 5 days. As expected, systemically treated chickens had much higher levels of gentamicin in the serum than topically treated chickens. Advantages and disadvantages to each method of drug administration are discussed.

Determinants of virulence and of resistance to ceftiofur, gentamicin, and spectinomycin in clinical Escherichia coli from broiler chickens in Québec, Canada.

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Chalmers, Gabhan; Cormier, Ashley C; Nadeau, Marie; Côté, Geneviève; Reid-Smith, Richard J; Boerlin, Patrick

2017-05-01

Antimicrobials are frequently used for the prevention of avian colibacillosis, with gentamicin used for this purpose in Québec until 2003. Ceftiofur was also used similarly, but voluntarily withdrawn in 2005 due to increasing resistance. Spectinomycin-lincomycin was employed as a replacement, but ceftiofur use was partially reinstated in 2007 until its definitive ban by the poultry industry in 2014. Gentamicin resistance frequency increased during the past decade in clinical Escherichia coli isolates from broiler chickens in Québec, despite this antimicrobial no longer being used. Since this increase coincided with the use of spectinomycin-lincomycin, co-selection of gentamicin resistance through spectinomycin was suspected. Therefore, relationships between spectinomycin, gentamicin, and ceftiofur resistance determinants were investigated here. The distribution of 13 avian pathogenic E. coli virulence-associated genes and their association with spectinomycin resistance were also assessed. A sample of 586 E. coli isolates from chickens with colibacillosis in Québec between 2009 and 2013 was used. The major genes identified for resistance to ceftiofur, gentamicin, and spectinomycin were bla CMY , aac(3)-VI, and aadA, respectively. The aadA and aac(3)-VI genes were strongly associated and shown to be located on a modified class 1 integron. The aadA and bla CMY genes were negatively associated, but when present together, were generally located on the same plasmids. No statistical positive association was observed between aadA and virulence genes, and virulence genes were only rarely detected on plasmids encoding spectinomycin resistance. Thus, the use of spectinomycin-lincomycin may likely select for gentamicin but not ceftiofur resistance, nor for any of the virulence-associated genes investigated. Copyright © 2017 Elsevier B.V. All rights reserved.

Contamination of the Clinical Microbiology Laboratory with Vancomycin-Resistant Enterococci and Multidrug- Resistant Enterobacteriaceae: Implications for Hospital and Laboratory Workers

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Collins, Susan M.; Hacek, Donna M.; Degen, Lisa A.; Wright, Marc O.; Noskin, Gary A.; Peterson, Lance R.

2001-01-01

We surveyed environmental surfaces in our clinical microbiology laboratory to determine the prevalence of vancomycin-resistant enterococci (VRE) and multidrug-resistant Enterobacteriaceae (MDRE) during a routine working day. From a total of 193 surfaces, VRE were present on 20 (10%) and MDRE were present on 4 (2%) of the surfaces tested. In a subsequent survey after routine cleaning, all of the 24 prior positive surfaces were found to be negative. Thus, those in the laboratory should recognize that many surfaces may be contaminated by resistant organisms during routine processing of patient specimens. PMID:11574615

The Emergence of Linezolid Resistance among Enterococci in Intestinal Microbiota of Treated Patients Is Unrelated to Individual Pharmacokinetic Characteristics

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Nguyen, T. T.; Defrance, G.; Massias, L.; Alavoine, L.; Lefort, A; Noel, V.; Senneville, E.; Doucet-Populaire, F.; Mentré, F.; Andremont, A.; Duval, X.

2014-01-01

Linezolid is an antimicrobial agent for the treatment of multiresistant Gram-positive infections. We assessed the impact of linezolid on the microbiota and the emergence of resistance and investigated its relationship with plasma pharmacokinetics of the antibiotic. Twenty-eight patients were treated for the first time with linezolid administered orally (n = 17) or parenterally (n = 11) at 600 mg twice a day. Linezolid plasma pharmacokinetic analysis was performed on day 7. Colonization by fecal enterococci, pharyngeal streptococci, and nasal staphylococci were assessed using selective media with or without supplemental linezolid. The resistance to linezolid was characterized. The treatment led to a decrease of enterococci, staphylococci, and streptococci in the fecal (P = 0.03), nasal, and pharyngeal (P linezolid resistance during treatment was observed only in the intestinal microbiota and unrelated to pharmacokinetic parameters. However, colonization by Gram-positive bacteria was reduced as a result of treatment in all microbiotas. PMID:24566182

Enviromnental contamination during a vancomycin-resistant Enterococci outbreak at a hospital in Argentina

OpenAIRE

Zarate, Mariela Soledad; Gales, Ana [UNIFESP; Jordd-Vargas, L'fiana; Yahni, Diego; RelloSo, Silvia; Bonvehi, Pablo; Monteiro, Jussimara [UNIFESP; Campos-Pignatari, Antonio [UNIFESP; Smayevsky, Jorgelina [UNIFESP

2007-01-01

INTRODUCTION. Vancomycin-resistant enterococci isolates (VRE) have caused numerous outbreaks in intensive care units (ICUs). A contaminated hospital environment, the hands of health care workers (HCW), and carrier patients may play important roles in perpetuating the chain of transmission in these outbreaks. the aims of this study were to report the first VRE outbreak in our center and assess the role of environmental contamination and HCW hands in the spread of new cases of enterococcal infe...

Activity of Daptomycin or Linezolid in Combination with Rifampin or Gentamicin against Biofilm-Forming Enterococcus faecalis or E. faecium in an In Vitro Pharmacodynamic Model Using Simulated Endocardial Vegetations and an In Vivo Survival Assay Using Galleria mellonella Larvae

Science.gov (United States)

Luther, Megan K.; Arvanitis, Marios; Mylonakis, Eleftherios

2014-01-01

Enterococci are the third most frequent cause of infective endocarditis. A high-inoculum stationary-phase in vitro pharmacodynamic model with simulated endocardial vegetations was used to simulate the human pharmacokinetics of daptomycin at 6 or 10 mg/kg of body weight/day or linezolid at 600 mg every 12 h (q12h), alone or in combination with gentamicin at 1.3 mg/kg q12h or rifampin at 300 mg q8h or 900 mg q24h. Biofilm-forming, vancomycin-susceptible Enterococcus faecalis and vancomycin-resistant Enterococcus faecium (vancomycin-resistant enterococcus [VRE]) strains were tested. At 24, 48, and 72 h, all daptomycin-containing regimens demonstrated significantly more activity (decline in CFU/g) than any linezolid-containing regimen against biofilm-forming E. faecalis. The addition of gentamicin to daptomycin (at 6 or 10 mg/kg) in the first 24 h significantly improved bactericidal activity. In contrast, the addition of rifampin delayed the bactericidal activity of daptomycin against E. faecalis, and the addition of rifampin antagonized the activities of all regimens against VRE at 24 h. Also, against VRE, the addition of gentamicin to linezolid at 72 h improved activity and was bactericidal. Rifampin significantly antagonized the activity of linezolid against VRE at 72 h. In in vivo Galleria mellonella survival assays, linezolid and daptomycin improved survival. Daptomycin at 10 mg/kg improved survival significantly over that with linezolid against E. faecalis. The addition of gentamicin improved the efficacy of daptomycin against E. faecalis and those of linezolid and daptomycin against VRE. We conclude that in enterococcal infection models, daptomycin has more activity than linezolid alone. Against biofilm-forming E. faecalis, the addition of gentamicin in the first 24 h causes the most rapid decline in CFU/g. Of interest, the addition of rifampin decreased the activity of daptomycin against both E. faecalis and VRE. PMID:24867993

Antimicrobial resistance and virulence profile of enterococci isolated from poultry and cattle sources in Nigeria.

Science.gov (United States)

Ngbede, Emmanuel Ochefije; Raji, Mashood Abiola; Kwanashie, Clara Nna; Kwaga, Jacob Kwada Paghi

2017-03-01

This study investigated the occurrence, antimicrobial resistance and virulence of Enterococcus from poultry and cattle farms. Three hundred and ninety samples: cloacal/rectal swabs (n = 260) and manure (n = 130] were processed for recovery of Enterococcus species. Standard bacteriological methods were used to isolate, identify and characterize Enterococcus species for antimicrobial susceptibility and expression of virulence traits. Detection of antibiotic resistance and virulence genes was carried out by polymerase chain reaction. Enterococcus was recovered from 167 (42.8%) of the 390 samples tested with a predominance of Enterococcus faecium (27.7%). Other species detected were Enterococcus gallinarum, Enterococcus faecalis, Enterococcus hirae, Enterococcus raffinosus, Enterococcus avium, Enterococcus casseliflavus, Enterococcus mundtii and Enterococcus durans. All the isolates tested were susceptible to vancomycin, but resistance to tetracycline, erythromycin, ampicillin and gentamicin was also observed among 61.0, 61.0, 45.1 and 32.7% of the isolates, respectively. Sixty (53.1%) of the isolates were multidrug resistant presenting as 24 different resistance patterns with resistance to gentamicin-erythromycin-streptomycin-tetracycline (CN-ERY-STR-TET) being the most common (n = 11) pattern. In addition to expression of virulence traits (haemolysin, gelatinase, biofilm production), antibiotic resistance (tetK, tetL, tetM, tetO and ermB) and virulence (asa1, gelE, cylA) genes were detected among the isolates. Also, in vitro transfer of resistance determinants was observed among 75% of the isolates tested. Our data revealed poultry, cattle and manure in this area are hosts to varying Enterococcus species harbouring virulence and resistance determinants that can be transferred to other organisms and also are important for causing nosocomial infection.

Resident cats in small animal veterinary hospitals carry multi-drug resistant enterococci and are likely involved in cross-contamination of the hospital environment

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Anuradha eGhosh

2012-02-01

Full Text Available In the U.S., small animal veterinary hospitals (SAVHs commonly keep resident cats living permanently as pets within their facilities. Previously, multi-drug resistant (MDR enterococci were found as a contaminant of multiple surfaces within such veterinary hospitals, and nosocomial infections are a concern. The objectives of this study were to determine whether resident cats carry MDR enterococci and if they potentially play a role in the contamination of the hospital environment. Enterococcal strains (n=180 were isolated from the feces of six healthy resident cats from different SAVHs. The concentration of enterococci ranged from 1.1 x 105 to 6.0 x 108 CFU g-1 of feces, and the population comprised E. hirae (38.3±18.6%, E. faecium (35.0±14.3%, E. faecalis (23.9±11.0%, and E. avium (2.8±2.2%. Testing of phenotypic resistance to 14 antimicrobial agents revealed multi-drug resistance (≥3 antimicrobials in 48.9% of all enterococcal isolates with most frequent resistance to tetracycline (72.8%, erythromycin (47.8%, and rifampicin (35.6%. Vancomycin resistant E. faecalis (3.9% with vanB not horizontally transferable in in vitro conjugation assays were detected from one cat. Genotyping (pulsed-field gel electrophoresis demonstrated a host-specific clonal population of MDR E. faecalis and E. faecium. Importantly, several feline isolates were genotypically identical or closely related to isolates from surfaces of cage door, thermometer, and stethoscope of the corresponding SAVHs. These data demonstrate that healthy resident cats at SAVHs carry MDR enterococci and likely contribute to contamination of the SAVH environment. Proper disposal and handling of fecal material and restricted movement of resident cats within the ward is recommended.

[Susceptibility of enterococci to natural and synthetic iron chelators].

Science.gov (United States)

Lisiecki, Paweł; Mikucki, Jerzy

2002-01-01

A total of 79 strains of enterococci belonging to 10 species were tested for susceptibility to natural and synthetic iron chelators. All strains produced siderophores. These enterococci were susceptible to three synthetic iron chelators only: 8-hydroxyquinoline, disodium versenate (EDTA) and o-phenanthroline. They were resistant to all other synthetic chelators: ethylenediamine-di(o-hydroxyphenylacetic acid) (EDDHA), nitrilotriacetate, 2,2'-bipiridyl, salicylic acid, 8-hydroxy-5-sulphonic acid and to all natural chelators: ovotransferrine, human apotransferrine, horse apoferritine, desferrioxamine B, ferrichrome and rhodotorulic acid. The relations between susceptibility/resistance, iron assimilation and structure and stability constants of iron chelators were discussed.

Persistence of vancomycin-resistant enterococci (VRE) in broiler houses after the avoparcin ban

DEFF Research Database (Denmark)

Heuer, Ole Eske; Pedersen, Karl; Jensen, Lars Bogø

2002-01-01

The glycopeptide growth promoter avoparcin was banned from animal production in the EU in 1997 due to concern for the spread of vancomycin-resistant enterococci (VRE) from food animals to humans. In recent Norwegian and Danish studies, extensive occurrence of VRE on broiler farms and in broiler......, and disinfection of the houses between rotations, and two consecutive broiler flocks from each house were sampled by taking cloacal swabs from the broilers at the time of slaughter. A total of 69 vancomycin-resistant Enterococcus faecium isolates obtained from broiler flocks and broiler houses were subjected......-isolates from different broiler houses and from flocks reared in different houses appeared to be genetically unrelated. These findings indicated that VRE was transmitted between consecutive broiler flocks by clones of resistant. bacteria surviving in the broiler houses despite cleaning and disinfection between...

Research Article Special Issue

African Journals Online (AJOL)

2016-05-15

May 15, 2016 ... recovered were as follows: Ciprofloxacin, 4.3%; Gentamicin, 4.3%; ... faecal carriage of drug-resistant Klebsiella spp. and Shigella spp. in Tabriz, Iran. 2. ..... in the spread of vancomycin-resistant enterococci: an important.

Human health risks associated with antimicrobial-resistant enterococci and Staphylococcus aureus on poultry meat

DEFF Research Database (Denmark)

Bortolaia, V.; Gongora, Carmen Espinosa; Guardabassi, L.

2016-01-01

health risks associated with the occurrence of these opportunistic human pathogens on poultry meat with particular focus on the risk of food-borne transmission of antimicrobial resistance. In the absence of conclusive evidence of transmission, this risk was inferred using data from scientific articles......-resistant S. aureus of livestock origin has been reported on poultry meat. In theory handling or ingestion of contaminated meat is a potential risk factor for colonization by methicillin-resistant S. aureus. However, this risk is presently regarded as negligible by public health authorities. Clinical......Enterococci and staphylococci are frequent contaminants on poultry meat. Enterococcus faecalis, Enterococcus faecium and Staphylococcus aureus are also well-known aetiological agents of a wide variety of infections resulting in major healthcare costs. This review provides an overview of the human...

Annual Surveillance Summary: Vancomycin-Resistant Enterococci (VRE) Infections in the Military Health System (MHS), 2016

Science.gov (United States)

2017-06-01

policy or position of the Department of the Navy, Department of Defense, nor the U.S. Government . i i VRE in the MHS: Annual Summary 2016 Prepared...continually increased from 1.16 infections per 100,000 persons in 2013 to 1.60 infections per 100,000 persons in 2015. A recent meta -analysis of VRE...associated with infections caused by vancomycin-resistant enterococci in the United States: systematic literature review and meta -analysis. Infect

Molecular Characterization of Glycopeptide-Resistant Enterococci from Hospitals of the Picardy Region (France

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M. Biendo

2010-01-01

Full Text Available We studied 138 glycopeptide-resistant enterococci (GRE strains, consisting of 131 glycopeptide-resistant Enterococcus faecium (GREfm and 7 glycopeptide-resistant Enterococcus faecalis (GREfs. The GREfm strains were resistant to penicillin, ampicillin, vancomycin, and teicoplanin, while the GREfs strains were only resistant to vancomycin and teicoplanin. The van A gene was the only glycopeptide determinant present in all GRE isolates investigated. Genes coding for Hyl and Hyl+ Esp were detected in 39 (29.8% and 92 (70.2% of the 131 GREfm isolates, respectively. Three of the 7 GREfs were positive for gelE+asa 1 genes, 3 for gel E gene, and 1 for asa 1 gene. The genetic relationship between the 138 GRE was analyzed by pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST. GREfm isolates were clustered in a single genogroup (pulsotype A, and GREfs were clustered in six genogroups (pulsotypes B-G. Among the isolates investigated by MLST, only 18 PCR products were sequenced (12 E. faecium and 6 E. faecalis, and 9 sequence types (STs were identified.

Antibiotic resistant enterococci—Tales of a drug resistance gene trafficker

DEFF Research Database (Denmark)

Werner, Guido; Coque, Teresa M.; Franz, Charles M.A.P.

2013-01-01

Enterococci have been recognized as important hospital-acquired pathogens in recent years, and isolates of E. faecalis and E. faecium are the third- to fourth-most prevalent nosocomial pathogen worldwide. Acquired resistances, especially against penicilin/ampicillin, aminoglycosides (high-level) ...

Dispersion of the vancomycin resistance genes vanA and vanC of Enterococcus isolated from Nile tilapia on retail sale: A public health hazard

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Kamelia Mahmoud Osman

2016-08-01

Full Text Available Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The acquisition of vancomycin resistance by enterococci (VRE has seriously affected the treatment and infection control of these organisms. VRE are frequently resistant to all antibiotics that are effective treatment for vancomycin-susceptible enterococci, which leaves clinicians treating VRE infections with limited therapeutic options. With VRE emerging as a global threat to public health, we aimed to isolate, identify enterococci species from tilapia and their resistance to van-mediated glycopeptide (vanA and vanC as well as the presence of enterococcal surface protein (esp using conventional and molecular methods. The cultural, biochemical (Vitek 2 system and PCR results revealed eight Enterococcus isolates from the 80 fish samples (10% to be further identified as E. faecalis (6/8, 75% and E gallinarum (2/8, 25%. Intraperitoneal injection of healthy Nile tilapia with the eight Enterococcus isolates caused significant morbidity (70% within 3 days and 100% mortality at 6 days post injection with general signs of septicemia. All of the eight Enterococcus isolates were found to be resistant to tetracycline. The 6/6 E. faecalis isolates were susceptible for penicillin, nitrofurantoin, gentamicin, and streptomycin. On the other hand 5/6 were susceptible for ampicillin, vancomycin, chloramphenicol and ciprofloxacin. The two isolates of E. gallinarum were sensitive to rifampicin and ciprofloxacin and resistant to vancomycin, chloramphenicol and erythromycin. Molecular characterization proved that they all presented the prototypic vanC element. On the whole, one of the two vancomycin resistance gene was present in 3/8 of the enterococci isolates, while the esp virulence gene was present in 1/8 of the enterococci isolates. The results in this study emphasise the potential role

Effect of gentamicin and levels of ambient sound on hearing screening outcomes in the neonatal intensive care unit: A pilot study.

Science.gov (United States)

Garinis, Angela C; Liao, Selena; Cross, Campbell P; Galati, Johnathan; Middaugh, Jessica L; Mace, Jess C; Wood, Anna-Marie; McEvoy, Lindsey; Moneta, Lauren; Lubianski, Troy; Coopersmith, Noe; Vigo, Nicholas; Hart, Christopher; Riddle, Artur; Ettinger, Olivia; Nold, Casey; Durham, Heather; MacArthur, Carol; McEvoy, Cynthia; Steyger, Peter S

2017-06-01

Hearing loss rates in infants admitted to neonatal intensive care units (NICU) run at 2-15%, compared to 0.3% in full-term births. The etiology of this difference remains poorly understood. We examined whether the level of ambient sound and/or cumulative gentamicin (an aminoglycoside) exposure affect NICU hearing screening results, as either exposure can cause acquired, permanent hearing loss. We hypothesized that higher levels of ambient sound in the NICU, and/or gentamicin dosing, increase the risk of referral on the distortion product otoacoustic emission (DPOAE) assessments and/or automated auditory brainstem response (AABR) screens. This was a prospective pilot outcomes study of 82 infants (4172 Hz) was 44%. DPOAE referrals were significantly greater for infants receiving >2 days of gentamicin dosing compared to fewer doses (p = 0.004). The effect of sound exposure and gentamicin treatment on hearing could not be determined due to the low number of NICU infants without gentamicin exposure (for control comparisons). All infants were exposed to higher levels of ambient sound that substantially exceed AAP guidelines. More referrals were generated by DPOAE assessments than with AABR screens, with significantly more DPOAE referrals with a high-frequency F2 range, consistent with sound- and/or gentamicin-induced cochlear dysfunction. Adding higher frequency DPOAE assessments to existing NICU hearing screening protocols could better identify infants at-risk for ototoxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Enterococci in the environment

Science.gov (United States)

Byappanahalli, Muruleedhara N.; Nevers, Meredith B.; Korajkic, Asja; Staley, Zachery R.; Harwood, Valerie J.

2012-01-01

Enterococci are common, commensal members of gut communities in mammals and birds, yet they are also opportunistic pathogens that cause millions of human and animal infections annually. Because they are shed in human and animal feces, are readily culturable, and predict human health risks from exposure to polluted recreational waters, they are used as surrogates for waterborne pathogens and as fecal indicator bacteria (FIB) in research and in water quality testing throughout the world. Evidence from several decades of research demonstrates, however, that enterococci may be present in high densities in the absence of obvious fecal sources and that environmental reservoirs of these FIB are important sources and sinks, with the potential to impact water quality. This review focuses on the distribution and microbial ecology of enterococci in environmental (secondary) habitats, including the effect of environmental stressors; an outline of their known and apparent sources, sinks, and fluxes; and an overview of the use of enterococci as FIB. Finally, the significance of emerging methodologies, such as microbial source tracking (MST) and empirical predictive models, as tools in water quality monitoring is addressed. The mounting evidence for widespread extraenteric sources and reservoirs of enterococci demonstrates the versatility of the genus Enterococcus and argues for the necessity of a better understanding of their ecology in natural environments, as well as their roles as opportunistic pathogens and indicators of human pathogens.

Prevalence and antibiotic resistance of Enterococcus spp. isolated from retail cheese, ready-to-eat salads, ham, and raw meat.

Science.gov (United States)

Pesavento, G; Calonico, C; Ducci, B; Magnanini, A; Lo Nostro, A

2014-08-01

Food specimens were analyzed in order to research Enterococcus spp.: 636 samples of raw meat (227 beef, 238 poultry, and 171 pork), 278 samples of cheese (110 fresh soft cheese and 168 mozzarella cheese), 214 samples of ready-to-eat salads, and 187 samples of ham. 312 strains of Enterococcus spp samples were isolated, then identified and submitted to susceptibility tests against 11 antimicrobial agents. The predominant species were Enterococcus faecalis in raw meat and Enterococcus faecium in retail products. Low percentages of microorganisms were resistant to vancomycin (3.53%), teicoplanin (2.24%), linezolid (0.32%), and amoxicillin in combination with clavulanic acid (0.32%). A high percentage of resistance was noted in E. faecalis at high level gentamicin (21.9%) and tetracycline (60.6%). In general, strains of E. faecalis were more resistant than E. faecium. Enterococci should be considered not only potential pathogens, but also a reservoir of genes encoding antibiotic resistance which can be transferred to other microorganisms. Continuous monitoring of their incidence and emerging resistance is important in order to identify foods which potentially represent a real risk to the population, and to ensure effective treatment of human enterococcal infections. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radiation sensitivity of Salmonella isolates relative to resistance to ampicillin, chloramphenicol or gentamicin

Science.gov (United States)

Niemira, Brendan A.; Lonczynski, Kelly A.; Sommers, Christopher H.

2006-09-01

Antibiotic resistance of inoculated bacteria is a commonly used selective marker. Bacteria resistant to the antibiotic nalidixic acid have been shown to have an increased sensitivity to irradiation. The purpose of this research was to screen a collection of Salmonella isolates for antibiotic resistance and determine the association, if any, of antibiotic resistance with radiation sensitivity. Twenty-four clinical isolates of Salmonella were screened for native resistance to multiple concentrations of ampicillin (Amp), chloramphenicol (Chl), or gentamicin (Gm). Test concentrations were chosen based on established clinical minimum inhibitory concentration (MIC) levels, and isolates were classified as either sensitive or resistant based on their ability to grow at or above the MIC. Salmonella cultures were grown overnight at (37 °C) in antibiotic-amended tryptic soy broth (TSB). Native resistance to Gm was observed with each of the 24 isolates (100%). Eight isolates (33%) were shown to be resistant to Amp, while seven isolates (29%) were shown to be resistant to Chl. In separate experiments, Salmonella cultures were grown overnight (37 °C) in TSB, centrifuged, and the cell pellets were re-suspended in phosphate buffer. The samples were then gamma irradiated at doses up to 1.0 kGy. The D10 values (the ionizing radiation dose required to reduce the viable number of microorganisms by 90%) were determined for the 24 isolates and they ranged from 0.181 to 0.359 kGy. No correlation was found between the D10 value of the isolate and its sensitivity or resistance to each of the three antibiotics. Resistance to Amp or Chl is suggested as appropriate resistance marker for Salmonella test strains to be used in studies of irradiation.

Radiation sensitivity of Salmonella isolates relative to resistance to ampicillin, chloramphenicol or gentamicin

International Nuclear Information System (INIS)

Niemira, Brendan A.; Lonczynski, Kelly A.; Sommers, Christopher H.

2006-01-01

Antibiotic resistance of inoculated bacteria is a commonly used selective marker. Bacteria resistant to the antibiotic nalidixic acid have been shown to have an increased sensitivity to irradiation. The purpose of this research was to screen a collection of Salmonella isolates for antibiotic resistance and determine the association, if any, of antibiotic resistance with radiation sensitivity. Twenty-four clinical isolates of Salmonella were screened for native resistance to multiple concentrations of ampicillin (Amp), chloramphenicol (Chl), or gentamicin (Gm). Test concentrations were chosen based on established clinical minimum inhibitory concentration (MIC) levels, and isolates were classified as either sensitive or resistant based on their ability to grow at or above the MIC. Salmonella cultures were grown overnight at (37 o C) in antibiotic-amended tryptic soy broth (TSB). Native resistance to Gm was observed with each of the 24 isolates (100%). Eight isolates (33%) were shown to be resistant to Amp, while seven isolates (29%) were shown to be resistant to Chl. In separate experiments, Salmonella cultures were grown overnight (37 o C) in TSB, centrifuged, and the cell pellets were re-suspended in phosphate buffer. The samples were then gamma irradiated at doses up to 1.0 kGy. The D 10 values (the ionizing radiation dose required to reduce the viable number of microorganisms by 90%) were determined for the 24 isolates and they ranged from 0.181 to 0.359 kGy. No correlation was found between the D 10 value of the isolate and its sensitivity or resistance to each of the three antibiotics. Resistance to Amp or Chl is suggested as appropriate resistance marker for Salmonella test strains to be used in studies of irradiation

Epidemiology of Extended-Spectrum beta-Lactamase-Producing E-coli and Vancomycin-Resistant Enterococci in the Northern Dutch-German Cross-Border Region

NARCIS (Netherlands)

Zhou, Xuewei; Garcia-Cobos, Silvia; Ruijs, Gijs J. H. M.; Kampinga, Greetje A.; Arends, Jan P.; Borst, Dirk M.; Moller, Lieke V.; Holman, Nicole D.; Schuurs, Theo A.; van Coppenraet, Lesla E. Bruijnesteijn; Weel, Jan F.; van Zeijl, Jan H.; Koeck, Robin; Rossen, John W. A.; Friedrich, Alexander W.

2017-01-01

Objectives: To reveal the prevalence and epidemiology of extended-spectrum β-lactamase (ESBL)- and/or plasmid AmpC (pAmpC)- and carbapenemase (CP) producing Enterobacteriaceae and vancomycin-resistant enterococci (VRE) across the Northern Dutch-German border region. Methods: A point-prevalence study

Is Penicillin plus Gentamicin Synergistic against Clinical Group B Streptococcus isolates?: A in-vitro Study.

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Corinne Ruppen

2016-10-01

Full Text Available Group B Streptococcus (GBS is increasingly causing invasive infections in nonpregnant adults. Elderly patients and those with comorbidities are at increased risk. On the basis of previous studies focusing on neonatal infections, penicillin plus gentamicin is recommended for infective endocarditis (IE and periprosthetic joint infections (PJI in adults. The purpose of this study was to investigate whether a synergism with penicillin and gentamicin is present in GBS isolates that caused IE and PJI. We used 5 GBS isolates, two clinical strains and three control strains, including one displaying high-level gentamicin resistance (HLGR. The results from the checkerboard and time-kill assays (TKAs were compared. For TKAs, antibiotic concentrations for penicillin were 0.048 and 0.2 mg/L, and for gentamicin 4 mg/L or 12.5 mg/L. In the checkerboard assay, the median fractional inhibitory concentration indices (FICIs of all isolates indicated indifference. TKAs for all isolates failed to demonstrate synergism with penicillin 0.048 or 0.2 mg/L, irrespective of gentamicin concentrations used. Rapid killing was seen with penicillin 0.048 mg/L plus either 4 mg/L or 12.5 mg/L gentamicin, from 2 h up to 8 h hours after antibiotic exposure. TKAs with penicillin 0.2 mg/L decreased the starting inoculum below the limit of quantification within 4 h to 6 h, irrespective of the addition of gentamicin. Fast killing was seen with penicillin 0.2 mg/L plus 12.5 mg/L gentamicin within the first 2 h. Our in vitro results indicate that the addition of gentamicin to penicillin contributes to faster killing at low penicillin concentrations, but only within the first few hours. Twenty-four hours after antibiotic exposure, PEN alone was bactericidal and synergism was not seen.

Surveillance and endemic vancomycin-resistant enterococci: some success in control is possible.

LENUS (Irish Health Repository)

Morris-Downes, M

2010-07-01

Vancomycin-resistant enterococci (VRE) are prevalent in many Irish hospitals. We analysed surveillance data from 2001 to 2008 in a centre where VRE is endemic. All clinically significant enterococci were tested for susceptibility to vancomycin. All intensive care unit admissions were screened on admission and weekly thereafter. Interventions included isolating\\/cohorting VRE patients, monthly prevalence surveys of VRE patients, the introduction of an electronic alert system, programmes to improve hand and environmental hygiene, and the appointment of an antibiotic pharmacist. There was a significant increase in the number of positive VRE screening samples from 2001 (1.96 patients with positive VRE screens per 10 000 bed-days) to 2006 (4.98 per 10 000 bed-days) (P < or = 0.001) with a decrease in 2007 (3.18 per 10 000 bed-days) (P < or = 0.01). The number of VRE bloodstream infections (BSI) increased from 0.09 BSI per 10 000 bed-days in 2001 to 0.78 per 10 000 bed-days in 2005 (P < or = 0.001) but decreased subsequently. Linear regression analysis indicated a significant association between new cases of VRE and non-isolated VRE patients, especially between May 2005 and December 2006 [P=0.009; 95% confidence interval (CI): 0.08-0.46] and between May 2005 and December 2008 (P = 0.008; 95% CI: 0.06-0.46). Routine surveillance for VRE together with other measures can control VRE BSI and colonisation, even where VRE is endemic, and where facilities are constrained.

Cell Wall Remodeling by a Synthetic Analog Reveals Metabolic Adaptation in Vancomycin Resistant Enterococci.

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Pidgeon, Sean E; Pires, Marcos M

2017-07-21

Drug-resistant bacterial infections threaten to overburden our healthcare system and disrupt modern medicine. A large class of potent antibiotics, including vancomycin, operate by interfering with bacterial cell wall biosynthesis. Vancomycin-resistant enterococci (VRE) evade the blockage of cell wall biosynthesis by altering cell wall precursors, rendering them drug insensitive. Herein, we reveal the phenotypic plasticity and cell wall remodeling of VRE in response to vancomycin in live bacterial cells via a metabolic probe. A synthetic cell wall analog was designed and constructed to monitor cell wall structural alterations. Our results demonstrate that the biosynthetic pathway for vancomycin-resistant precursors can be hijacked by synthetic analogs to track the kinetics of phenotype induction. In addition, we leveraged this probe to interrogate the response of VRE cells to vancomycin analogs and a series of cell wall-targeted antibiotics. Finally, we describe a proof-of-principle strategy to visually inspect drug resistance induction. Based on our findings, we anticipate that our metabolic probe will play an important role in further elucidating the interplay among the enzymes involved in the VRE biosynthetic rewiring.

Gentamicin serum concentrations in patients with gentamicin-PMMA beads for infected hip joints : A prospective observational cohort study

NARCIS (Netherlands)

De Klaver, Paul A.G.; Hendriks, Johannes G.E.; Van Onzenoort, Hein A.W.; Schreurs, Berend W.; Touw, Daan J.; Derijks, Luc J.J.

Background: Gentamicin-polymethylmethacrylate (PMMA) beads release gentamicin gradually, and high concentrations develop only locally. It is unclear how frequent and in which patients gentamicin serum concentrations are measurable and possibly lead to toxicity. The aim of this study was to

Prevalence and distribution of VRE (vancomycin resistant enterococci and VSE (vancomycin susceptible enterococci strains in the breeding environment

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Krzysztof Skowron

2016-06-01

Full Text Available [b]Introduction.[/b] Intensive animal production causes numerous problems. Facilities connected with animal maintenance not only cause environmental pollution, but also pose a great sanitary and epidemiological threat. Long-term use of antibiotics in animal production lead animal-borne microorganisms to develop multiple resistance mechanisms, transferred to the typical environmental bacteria. [b]Objective. [/b]The aim of this study was assessment of E. faecalis, E. faecium, E. durans and E. hirae prevalence in samples gathered from swine production sectors, and determination of the contribution of VRE (vancomycin resistant enterococci strains and their resistance. The degree of relationship between isolates of each species from genus Enterococcus was also determined. [b]Materials and method.[/b] 195 isolates were obtained, from which DNA was isolated. Genus identification was conducted with the primers specific to the 16S rRNA region, and identification of the species with primers specific to sequence of gene sodA in Multiplex PCR reaction. Resistance to vancomycin (6 μg×ml -1 was tested using a screening method on Muller Hinton Agar. To assess resistance type Multiplex PCR, amplifying products corresponding to genes VanA, VanB and VanC, was conducted. Genotyping was conducted using the PCR-RAPD method. [b]Results. [/b]Among the 195 isolates, 133 (68% belonged to E. hirae. The other species contributions were respectively: E. faecalis – 21%, E. durans – 8% and E. faecium – 3%. Only 2 isolates of E. hirae, being different strains, were resistant to vancomycin. Both were representing phenotype VanC1. 60 genetically different strains were defined. The possible contamination paths involved animal feed and spreading of excrements by slaughtered individuals or on personnel’s footwear. [b]Conclusions. [/b]The obtained results indicate a very low percentage of VRE strains in the tested piggery, resulting in a low health risk to piggery

Contribution of sand-associated enterococci to dry weather water quality.

Science.gov (United States)

Halliday, Elizabeth; Ralston, David K; Gast, Rebecca J

2015-01-06

Culturable enterococci and a suite of environmental variables were collected during a predominantly dry summer at a beach impacted by nonpoint source pollution. These data were used to evaluate sands as a source of enterococci to nearshore waters, and to assess the relationship between environmental factors and dry-weather enterococci abundance. Best-fit multiple linear regressions used environmental variables to explain more than half of the observed variation in enterococci in water and dry sands. Notably, during dry weather the abundance of enterococci in dry sands at the mean high-tide line was significantly positively related to sand moisture content (ranging from sands. Tidal forcing modulated the abundance of enterococci in the water, as both turbidity and enterococci were elevated during ebb and flood tides. The probability of samples violating the single-sample maximum was significantly greater when collected during periods with increased tidal range: spring ebb and flood tides. Tidal forcing also affected groundwater mixing zones, mobilizing enterococci from sand to water. These data show that routine monitoring programs using discrete enterococci measurements may be biased by tides and other environmental factors, providing a flawed basis for beach closure decisions.

Comparison of E-test with other conventional susceptibility testing methods for ciprofloxacin and gentamicin against gram negative enteric bacilli.

Science.gov (United States)

Ogbolu, D O; Terry-Alli, O A; Daini, O A; Olabiyi, F A; Igharo, E A

2012-06-01

Increasing antibiotic resistance in Gram negative bacteria has led to the need for a faster and reliable method for determining antimicrobial susceptibility testing. In a resource poor setting like ours, it's also important to look for methods that will be clinically and economically beneficial to the patient. This study was aimed at evaluating the Epsilometer test (E-test) and conventional methods for determining antimicrobial susceptibility of isolates of Gram-negative enteric bacteria to ciprofloxacin and gentamicin. Disc diffusion, E-test, broth dilution and agar dilution methods were performed on 54 bacterial isolates. Using the E-test, 88.9% of bacterial isolates were resistant to ciprofloxacin, 92.6% were resistant using broth microdilution, 96.3% were resistant using agar dilution and 72.2% were resistant using disc diffusion. Minimum inhibitory concentration (MIC50) of isolates for gentamicin showed significant difference for all the techniques (p 0.05). Both E-test and broth dilution methods showed high levels of agreement (p > 0.05), there were low levels of agreement between E-test and agar dilution method (p < 0.05), especially at MIC50. The E-test can therefore be considered a reliable method to determine antimicrobial susceptibility testing and it gives results which are at least as accurate as those obtained by the broth dilution method.

Impact of High-Level Daptomycin Resistance in the Streptococcus mitis Group on Virulence and Survivability during Daptomycin Treatment in Experimental Infective Endocarditis

Science.gov (United States)

Garcia-de-la-Maria, C.; Xiong, Y. Q.; Pericas, J. M.; Armero, Y.; Moreno, A.; Mishra, N. N.; Rybak, M. J.; Tran, T. T.; Arias, C. A.; Sullam, P. M.; Bayer, A. S.

2017-01-01

ABSTRACT Among the viridans group streptococci, the Streptococcus mitis group is the most common cause of infective endocarditis. These bacteria have a propensity to be β-lactam resistant, as well as to rapidly develop high-level and durable resistance to daptomycin (DAP). We compared a parental, daptomycin-susceptible (DAPs) S. mitis/S. oralis strain and its daptomycin-resistant (DAPr) variant in a model of experimental endocarditis in terms of (i) their relative fitness in multiple target organs in this model (vegetations, kidneys, spleen) when animals were challenged individually and in a coinfection strategy and (ii) their survivability during therapy with daptomycin-gentamicin (an in vitro combination synergistic against the parental strain). The DAPr variant was initially isolated from the cardiac vegetations of animals with experimental endocarditis caused by the parental DAPs strain following treatment with daptomycin. The parental strain and the DAPr variant were comparably virulent when animals were individually challenged. In contrast, in the coinfection model without daptomycin therapy, at both the 106- and 107-CFU/ml challenge inocula, the parental strain outcompeted the DAPr variant in all target organs, especially the kidneys and spleen. When the animals in the coinfection model of endocarditis were treated with DAP-gentamicin, the DAPs strain was completely eliminated, while the DAPr variant persisted in all target tissues. These data underscore that the acquisition of DAPr in S. mitis/S. oralis does come at an intrinsic fitness cost, although this resistance phenotype is completely protective against therapy with a potentially synergistic DAP regimen. PMID:28264848

A classification system for plasmids from Enterococci and other Gram-positive bacteria

DEFF Research Database (Denmark)

Jensen, Lars Bogø; Garcia-Migura, Lourdes; Valenzuela, Antonio Jesus Sanchez

2010-01-01

A classification system for plasmids isolated from enterococci and other Gram-positive bacteria was developed based on 111 published plasmid sequences from enterococci and other Gram-positive bacteria; mostly staphylococci. Based on PCR amplification of conserved areas of the replication initiating....... Furthermore, conjugation experiments were performed obtaining 30 transconjugants when selecting for antimicrobial resistance. Among them 19 gave no positive amplicons indicating presence of rep-families not tested for in this experimental setup....

In vitro antibacterial activity of tigecycline against clinical isolates of Linezolid-Intermediate (LIE and Linezolid-Resistant Enterococci (LRE by time-kill assay

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Gustavo Enck Sambrano

2014-08-01

Full Text Available Introduction: Enterococci have become the third major leading cause of nosocomial bacteraemia, an infection which is significantly associated with the risk of developing infective endocarditis. Linezolid provides high rates of clinical cure and microbiologic success in complicated infections due to Enterococcus spp. However, several instances of emergence of resistance during linezolid treatment have been reported. The aim of this study was evaluate the activity of tigecycline against Linezolid-Intermediate (LIE and Linezolid-Resistant Enterococcus faecalis (LRE by the time-kill assay. Methods: Five isolates of LRE and two isolates of LIE were used in this study. MICs were determined by broth dilution following the CLSI (2014 guidelines. Time-kill assay was employed to access the in vitro response profile of tigecycline. Results: All seven of the isolates presented MIC of 0.125μg/mL. Tigecycline activity was individually evaluated and in three of the five isolates of LRE it presented bactericidal. Against the other isolates, tigecycline showed bacteriostatic activity. The tigecycline activity was measured according to CLSI criteria. Conclusions: Tigecycline presented both bacteriostatic and bactericidal activity against tested isolates, result not yet described in previous studies. Time and concentrations above MIC were key factors to achieving bactericidal effect. MIC and the tested concentration below it resulted in bacteriostatical effect to enterococci, corroborating previous data.

Trends in antimicrobial resistance among clinical isolates of enterococci in a Brazilian tertiary hospital: a 4-year study Evolução da resistência aos antimicrobianos entre isolados clínicos de enterococos em um hospital terciário brasileiro: um estudo de 4 anos

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Natália Conceição

2011-04-01

Full Text Available INTRODUCTION: In the past two decades members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. This study prospectively analyzed the distribution of species and trends in antimicrobial resistance among clinical isolates of enterococci in a Brazilian tertiary hospital from 2006-2009. METHODS: Enterococcal species were identified by conventional biochemical tests. The antimicrobial susceptibility profile was performed by disk diffusion in accordance with the Clinical and Laboratory Standards Institute (CLSI. A screening test for vancomycin was also performed. Minimal inhibitory concentration (MIC for vancomycin was determined using the broth dilution method. Molecular assays were used to confirm speciation and genotype of vancomycin-resistant enterococci (VRE. RESULTS: A total of 324 non-repetitive enterococcal isolates were recovered, of which 87% were E. faecalis and 10.8% E. faecium. The incidence of E. faecium per 1,000 admissions increased significantly (p 256µg/ mL and harbored vanA genes. The majority (89.5% of VRE belonged to E. faecium species, which were characteristically resistant to ampicillin and quinolones. Overall, ampicillin resistance rate increased significantly from 2.5% to 21.4% from 2006-2009. Resistance rates for gentamicin, chloramphenicol, tetracycline, and erythromycin significantly decreased over time, although they remained high. Quinolones resistance rates were high and did not change significantly over time. CONCLUSIONS: The data obtained show a significant increasing trend in the incidence of E. faecium resistant to ampicillin and vancomycin.INTRODUÇÃO: Nas últimas duas décadas, os enterococos emergiram como importantes patógenos nosocomiais no mundo inteiro. Neste estudo, foi analisada a distribuição das espécies e a evolução da resistência aos antimicrobianos entre isolados clínicos de enterococos obtidos em um hospital terciário, no período de 2006 a 2009. M�

Fosfomycin Addition to Poly(D,L-Lactide Coating Does Not Affect Prophylaxis Efficacy in Rat Implant-Related Infection Model, But That of Gentamicin Does.

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Anil Gulcu

Full Text Available Gentamicin is the preferred antimicrobial agent used in implant coating for the prevention of implant-related infections (IRI. However, the present heavy local and systemic administration of gentamicin can lead to increased resistance, which has made its future use uncertain, together with related preventive technologies. Fosfomycin is an alternative antimicrobial agent that lacks the cross-resistance presented by other classes of antibiotics. We evaluated the efficacy of prophylaxis of 10% fosfomycin-containing poly(D,L-lactide (PDL coated K-wires in a rat IRI model and compared it with uncoated (Control 1, PDL-coated (Control 2, and 10% gentamicin-containing PDL-coated groups with a single layer of coating. Stainless steel K-wires were implanted and methicillin-resistant Staphylococcus aureus (ATCC 43300 suspensions (103 CFU/10 μl were injected into a cavity in the left tibiae. Thereafter, K-wires were removed and cultured in tryptic soy broth and then 5% sheep blood agar mediums. Sliced sections were removed from the tibiae, stained with hematoxylin-eosin, and semi-quantitatively evaluated with X-rays. The addition of fosfomycin into PDL did not affect the X-ray and histopathological evaluation scores; however, the addition of gentamicin lowered them. The addition of gentamicin showed a protective effect after the 28th day of X-ray evaluations. PDL-only coating provided no protection, while adding fosfomycin to PDL offered a 20% level protection and adding gentamicin offered 80%. Furthermore, there were 103 CFU level growths in the gentamicin-added group, while the other groups had 105. Thus, the addition of fosfomycin to PDL does not affect the efficacy of prophylaxis, but the addition of gentamicin does. We therefore do not advise the use of fosfomycin as a single antimicrobial agent in coating for IRI prophylaxis.

Vancomycin-resistant enterococci with vanA gene in treated municipal wastewater and their association with human hospital strains.

Science.gov (United States)

Oravcova, Veronika; Mihalcin, Matus; Zakova, Jana; Pospisilova, Lucie; Masarikova, Martina; Literak, Ivan

2017-12-31

Vancomycin-resistant enterococci (VRE) are pathogens of increasing medical importance. In Brno, Czech Republic, we collected 37 samples from the effluent of a wastewater treatment plant (WWTP), 21 surface swabs from hospital settings, and 59 fecal samples from hospitalized patients and staff. Moreover, we collected 284 gull cloacal swabs from the colony situated 35km downstream the WWTP. Samples were cultured selectively. Enterococci were identified using MALDI-TOF MS, phenotypically tested for susceptibility to antibiotics, and by PCR for occurrence of resistance and virulence genes. Pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) were used to examine genotypic diversity. VRE carrying the vanA gene were found in 32 (86%, n=37) wastewater samples, from which we obtained 49 isolates: Enterococcus faecium (44) and Enterococcus gallinarum (2), Enterococcus casseliflavus (2), and Enterococcus raffinosus (1). From 33 (69%) of 48 inpatient stool samples, we obtained 39 vanA-carrying VRE, which belonged to E. faecium (33 isolates), Enterococcus faecalis (4), and Enterococcus raffinosus (2). Nearly one-third of the samples from hospital surfaces contained VRE with the vanA gene. VRE were not detected among gulls. Sixty-seven (84%, n=80) E. faecium isolates carried virulence genes hyl and/or esp. Virulence of E. faecalis was encoded by gelE, asa1, and cylA genes. A majority of the E. faecium isolates belonged to the clinically important sequence types ST17 (WWTP: 10 isolates; hospital: 4 isolates), ST18 (9;8), and ST78 (5;0). The remaining isolates belonged to ST555 (2;0), ST262 (1;6), ST273 (3;0), ST275 (1;0), ST549 (2;0), ST19 (0;1), ST323 (3;0), and ST884 (7;17). Clinically important enterococci carrying the vanA gene were almost continually detectable in the effluent of the WWTP, indicating insufficient removal of VRE during wastewater treatment and permanent shedding of these antibiotic resistant pathogens into the environment from this

Silica-Gentamicin Nanohybrids: Synthesis and Antimicrobial Action

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Dina Ahmed Mosselhy

2016-03-01

Full Text Available Orthopedic applications commonly require the administration of systemic antibiotics. Gentamicin is one of the most commonly used aminoglycosides in the treatment and prophylaxis of infections associated with orthopedic applications, but gentamicin has a short half-life. However, silica nanoparticles (SiO2 NPs can be used as elegant carriers for antibiotics to prolong their release. Our goal is the preparation and characterization of SiO2-gentamicin nanohybrids for their potential antimicrobial administration in orthopedic applications. In vitro gentamicin release profile from the nanohybrids (gentamicin-conjugated SiO2 NPs prepared by the base-catalyzed precipitation exhibited fast release (21.4% during the first 24 h and further extension with 43.9% release during the five-day experiment. Antimicrobial studies of the SiO2-gentamicin nanohybrids versus native SiO2 NPs and free gentamicin were performed against Bacillus subtilis (B. subtilis, Pseudomonas fluorescens (P. fluorescens and Escherichia coli (E. coli. SiO2-gentamicin nanohybrids were most effective against B. subtilis. SiO2 NPs play no antimicrobial role. Parallel antimicrobial studies for the filter-sterilized gentamicin were performed to assess the effect of ultraviolet (UV-irradiation on gentamicin. In summary, the initial fast gentamicin release fits the need for high concentration of antibiotics after orthopedic surgical interventions. Moreover, the extended release justifies the promising antimicrobial administration of the nanohybrids in bone applications.

Frequency and Antibiogram of Vancomycin Resistant Enterococcus in a Tertiary Care Hospital

International Nuclear Information System (INIS)

Babar, N.; Usman, J.; Munir, T.; Gill, M. M.; Anjum, R.; Gilani, M.; Latif, M.

2014-01-01

Objective: To determine the frequency of Vancomycin Resistant Enterococcus (VRE) in a tertiary care hospital of Rawalpindi, Pakistan. Study Design: Observational, cross-sectional study. Place and Duration of Study: Department of Microbiology, Army Medical College, Rawalpindi, from May 2011 to May 2012. Methodology: Vancomycin resistant Enterococcus isolated from the clinical specimens including blood, pus, double lumen tip, ascitic fluid, tracheal aspirate, non-directed bronchial lavage (NBL), cerebrospinal fluid (CSF), high vaginal swab (HVS) and catheter tips were cultured on blood agar and MacConkey agar, while the urine samples were grown on cystine lactose electrolyte deficient agar. Later the antimicrobial susceptibility testing of the isolates was carried out using the modified Kirby-Bauer disc diffusion method on Mueller Hinton agar. Results: A total of 190 enterococci were isolated. Of these, 22 (11.57%) were found to be resistant to vancomycin. The antimicrobial sensitivity pattern revealed maximum resistance against ampicillin (86.36%) followed by erythromycin (81.81%) and gentamicin (68.18%) while all the isolates were 100% susceptible to chloramphenicol and linezolid. Conclusion: The frequency of VRE was 11.57% with the highest susceptibility to linezolid and chloramphenicol. (author)

Structural Analysis of the Tobramycin and Gentamicin Clinical Resistome Reveals Limitations for Next-generation Aminoglycoside Design.

Science.gov (United States)

Bassenden, Angelia V; Rodionov, Dmitry; Shi, Kun; Berghuis, Albert M

2016-05-20

Widespread use and misuse of antibiotics has allowed for the selection of resistant bacteria capable of avoiding the effects of antibiotics. The primary mechanism for resistance to aminoglycosides, a broad-spectrum class of antibiotics, is through covalent enzymatic modification of the drug, waning their bactericidal effect. Tobramycin and gentamicin are two medically important aminoglycosides targeted by several different resistance factors, including aminoglycoside 2″-nucleotidyltransferase [ANT(2″)], the primary cause of aminoglycoside resistance in North America. We describe here two crystal structures of ANT(2″), each in complex with AMPCPP, Mn(2+), and either tobramycin or gentamicin. Together these structures outline ANT(2″)'s specificity for clinically used substrates. Importantly, these structures complete our structural knowledge for the set of enzymes that most frequently confer clinically observed resistance to tobramycin and gentamicin. Comparison of tobramycin and gentamicin binding to enzymes in this resistome, as well as to the intended target, the bacterial ribosome, reveals surprising diversity in observed drug-target interactions. Analysis of the diverse binding modes informs that there are limited opportunities for developing aminoglycoside analogs capable of evading resistance.

Gentamicin Exposure and Sensorineural Hearing Loss in Preterm Infants.

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Aline Fuchs

Full Text Available To evaluate the impact of gentamicin exposure on sensorineural hearing loss (SNHL in very low birth weight (VLBW infants.Exposure to gentamicin was determined in infants born between 1993 and 2010 at a gestational age < 32 weeks and/or with a birthweight < 1500 g, who presented with SNHL during the first 5 years of life. For each case, we selected two controls matched for gender, gestational age, birthweight, and year of birth.We identified 25 infants affected by SNHL, leading to an incidence of SNHL of 1.58% in our population of VLBW infants. The proportion of infants treated with gentamicin was 76% in the study group and 70% in controls (p = 0.78. The total cumulated dose of gentamicin administered did not differ between the study group (median 10.2 mg/kg, Q1-Q3 1.6-13.2 and the control group (median 7.9 mg/kg, Q1-Q3 0-12.8, p = 0.47. The median duration of gentamicin treatment was 3 days both in the study group and the control group (p = 0.58. Maximum predicted trough serum levels of gentamicin, cumulative area under the curve and gentamicin clearance were not different between cases and controls.The impact of gentamicin on SNHL can be minimized with treatments of short duration, monitoring of blood levels and dose adjustment.

[Enterococcal endocarditis: a multicenter study of 76 cases].

Science.gov (United States)

Martínez-Marcos, Francisco Javier; Lomas-Cabezas, José Manuel; Hidalgo-Tenorio, Carmen; de la Torre-Lima, Javier; Plata-Ciézar, Antonio; Reguera-Iglesias, José María; Ruiz-Morales, Josefa; Márquez-Solero, Manuel; Gálvez-Acebal, Juan; de Alarcón-González, Arístides

2009-12-01

Although enterococci occupy the third position among microorganisms producing infectious endocarditis (IE) following streptococci and Staphylococcus aureus, few multicenter studies have provided an in-depth analysis of enterococcal IE. Description of the characteristics of 76 cases of enterococcal left-sided infectious endocarditis (LSIE) (native: 59, prosthetic: 17) retrieved from the database of the Cardiovascular Infections Study Group of the Andalusian Society of Infectious Diseases, with emphasis on the comparison with non-enterococcal LSIE. Enterococci were the causal agent in 76 of the 696 episodes of LSIE (11%). Compared with non-enterococcal LSIE, enterococcal LSIE was more commonly seen in patients older than 65 (47.4% vs. 27.6%, P<0.0005), and those with chronic diseases (75% vs. 54.6%, P<0.001), calcified valves (18.6% vs. 10%, P<0.05), and previous urinary (30.3% vs. 2.1%, P<0.00001) or abdominal (10.5% vs. 3.1%, P<0.01) infections, and produced a higher rate of relapses (6.6% vs. 2.3%, P<0.05). Enterococcal LSIE was associated with fewer peripheral vascular or skin manifestations (14.5% vs. 27.1%, P<0.05) and fewer immunological phenomena (10.5% vs. 24%, P<0.01). Among the total of patients with enterococcal LSIE, 36.8% underwent valve surgery during hospitalization. In-hospital mortality was 32.9% for enterococcal LSIE, 9.3% for viridans group streptococci (VGS) LSIE and 48.6% for S. aureus LSIE (enterococci vs VGS: P<0.0001; enterococci vs S. aureus: P=0.02). Enterococcal LSIE patients treated with the combination of a penicillin or vancomycin plus an aminoglycoside (n=60) and those treated with ampicillin plus ceftriaxone (n=6) showed similar in-hospital mortality (26.7% vs 33.3%, P=0.66). High-level resistance to gentamicin was detected in 5 of 38 episodes of enterococcal LSIE (13.1%). Enterococcal LSIE appears in patients with well-defined clinical characteristics, and causes few peripheral vascular or skin manifestations and few immunological

Occurrence of vancomycin-resistant and -susceptible Enterococcus spp. in reclaimed water used for spray irrigation

Energy Technology Data Exchange (ETDEWEB)

Carey, Stephanie Ann; Goldstein, Rachel E. Rosenberg [Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD (United States); Gibbs, Shawn G. [Department of Environmental Health, School of Public Health-Bloomington, Indiana University, Bloomington, IN (United States); Claye, Emma [Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD (United States); He, Xin [Department of Epidemiology and Biostatistics, University of Maryland School of Public Health, College Park, MD (United States); Sapkota, Amy R., E-mail: ars@umd.edu [Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD (United States)

2016-05-15

Reclaiming municipal wastewater for agricultural, environmental, and industrial purposes is increasing in the United States to combat dwindling freshwater supplies. However, there is a lack of data regarding the microbial quality of reclaimed water. In particular, no previous studies have evaluated the occurrence of vancomycin-resistant enterococci (VRE) in reclaimed water used at spray irrigation sites in the United States. To address this knowledge gap, we investigated the occurrence, concentration, and antimicrobial resistance patterns of VRE and vancomycin-susceptible enterococci at three U.S. spray irrigation sites that use reclaimed water. We collected 48 reclaimed water samples from one Mid-Atlantic and two Midwest spray irrigation sites, as well as their respective wastewater treatment plants, in 2009 and 2010. Samples were analyzed for total enterococci and VRE using standard membrane filtration. Isolates were purified and then confirmed using biochemical tests and PCR. Antimicrobial susceptibility testing was conducted using the Sensititre® microbroth dilution system. Data were analyzed by two-sample proportion tests and one-way analysis of variance. We detected total enterococci and VRE in 71% (34/48) and 4% (2/48) of reclaimed water samples, respectively. Enterococcus faecalis was the most common species identified. At the Mid-Atlantic spray irrigation site, UV radiation decreased total enterococci to undetectable levels; however, subsequent storage in an open-air pond at this site resulted in increased concentrations of enterococci. E. faecalis isolates recovered from the Mid-Atlantic spray irrigation site expressed intrinsic resistance to quinupristin/dalfopristin; however, non-E. faecalis isolates expressed resistance to quinupristin/dalfopristin (52% of isolates), vancomycin (4%), tetracycline (13%), penicillin (4%) and ciprofloxacin (17%). Our findings show that VRE are present in low numbers in reclaimed water at point-of-use at the sampled spray

Occurrence of vancomycin-resistant and -susceptible Enterococcus spp. in reclaimed water used for spray irrigation

International Nuclear Information System (INIS)

Carey, Stephanie Ann; Goldstein, Rachel E. Rosenberg; Gibbs, Shawn G.; Claye, Emma; He, Xin; Sapkota, Amy R.

2016-01-01

Reclaiming municipal wastewater for agricultural, environmental, and industrial purposes is increasing in the United States to combat dwindling freshwater supplies. However, there is a lack of data regarding the microbial quality of reclaimed water. In particular, no previous studies have evaluated the occurrence of vancomycin-resistant enterococci (VRE) in reclaimed water used at spray irrigation sites in the United States. To address this knowledge gap, we investigated the occurrence, concentration, and antimicrobial resistance patterns of VRE and vancomycin-susceptible enterococci at three U.S. spray irrigation sites that use reclaimed water. We collected 48 reclaimed water samples from one Mid-Atlantic and two Midwest spray irrigation sites, as well as their respective wastewater treatment plants, in 2009 and 2010. Samples were analyzed for total enterococci and VRE using standard membrane filtration. Isolates were purified and then confirmed using biochemical tests and PCR. Antimicrobial susceptibility testing was conducted using the Sensititre® microbroth dilution system. Data were analyzed by two-sample proportion tests and one-way analysis of variance. We detected total enterococci and VRE in 71% (34/48) and 4% (2/48) of reclaimed water samples, respectively. Enterococcus faecalis was the most common species identified. At the Mid-Atlantic spray irrigation site, UV radiation decreased total enterococci to undetectable levels; however, subsequent storage in an open-air pond at this site resulted in increased concentrations of enterococci. E. faecalis isolates recovered from the Mid-Atlantic spray irrigation site expressed intrinsic resistance to quinupristin/dalfopristin; however, non-E. faecalis isolates expressed resistance to quinupristin/dalfopristin (52% of isolates), vancomycin (4%), tetracycline (13%), penicillin (4%) and ciprofloxacin (17%). Our findings show that VRE are present in low numbers in reclaimed water at point-of-use at the sampled spray

Tritium labeled Gentamicin C : II.- Bioradioactive products of Gentamicin by Catalytic H2O-3H exchange reaction

International Nuclear Information System (INIS)

Suarez, C.; Diaz, A.; Paz, D.; Jimeno, M.L.

1992-01-01

The main bioradioactive degradation products from catalytic hydrogen exchange of gentamicin C, (C1 + C2 + C1a) in basic form, are generated by N-dimethylations in 3 - N and 6'-N positions. Their structures were confirmed by HNMR and 13 CNMR. These derivatives were fractionated by chromatography on silica gel. Antibacterial activities were similar to those of the parent antibiotics. Tritium exchange, under vacuum or nitrogen, is highly increased (4:1) when gentamicina are in basic form. In contrast with gentamicin sulfate, hydrolytic subproducts as garamine, gentamicine, garosamine and purpurosamines are practically absent. To properly optimize the exchange process, the composition of the gentamicin C complex must be taken into account. The exchange decreases in the order C2 > C1 > C1a. Because of 6' -N-dimenthyl gentamicin C1 is C2, the radiochemical yield of C2 appears enhanced in the H 2 O- 3 H exchange of a mixture of them. Radioactivity distribution among the components and subunits of these three gentamicins were studied by stron and mild hydrolysis, and by methanolysis. (author)

Characterisation of the selective binding of antibiotics vancomycin and teicoplanin by the VanS receptor regulating type A vancomycin resistance in the enterococci.

Science.gov (United States)

Hughes, C S; Longo, E; Phillips-Jones, M K; Hussain, R

2017-08-01

A-type resistance towards "last-line" glycopeptide antibiotic vancomycin in the leading hospital acquired infectious agent, the enterococci, is the most common in the UK. Resistance is regulated by the VanR A S A two-component system, comprising the histidine sensor kinase VanS A and the partner response regulator VanR A . The nature of the activating ligand for VanS A has not been identified, therefore this work sought to identify and characterise ligand(s) for VanS A . In vitro approaches were used to screen the structural and activity effects of a range of potential ligands with purified VanS A protein. Of the screened ligands (glycopeptide antibiotics vancomycin and teicoplanin, and peptidoglycan components N-acetylmuramic acid, D-Ala-D-Ala and Ala-D-y-Glu-Lys-D-Ala-D-Ala) only glycopeptide antibiotics vancomycin and teicoplanin were found to bind VanS A with different affinities (vancomycin 70μM; teicoplanin 30 and 170μM), and were proposed to bind via exposed aromatic residues tryptophan and tyrosine. Furthermore, binding of the antibiotics induced quicker, longer-lived phosphorylation states for VanS A , proposing them as activators of type A vancomycin resistance in the enterococci. Copyright © 2017 Diamond Light Source Ltd. Published by Elsevier B.V. All rights reserved.

Alternating Mupirocin/Gentamicin is Associated with Increased Risk of Fungal Peritonitis as Compared with Gentamicin Alone - Results of a Randomized Open-Label Controlled Trial.

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Wong, Ping-Nam; Tong, Gensy M W; Wong, Yuk-Yi; Lo, Kin-Yee; Chan, Shuk-Fan; Lo, Man-Wai; Lo, Kwok-Chi; Ho, Lo-Yi; Tse, Cindy W S; Mak, Siu-Ka; Wong, Andrew K M

2016-01-01

♦ Catheter-related infection, namely exit-site infection (ESI) and peritonitis, is a major infectious complication and remains a main cause of technique failure for patients receiving peritoneal dialysis (PD). Topical application of antibiotic cream might reduce catheter-related infection but emergence of resistant or opportunistic organisms could be a concern. Optimal topical agents and regimens remain to be determined. We did a study to examine the effect of an alternating topical antibiotic regimen in preventing catheter-related infection. ♦ We performed a single-center, randomized, open-label study to compare daily topical application of gentamicin cream with a gentamicin/mupirocin alternate regimen to the exit site. Patients randomized to alternating regimen were asked to have daily application of gentamicin cream in odd months and mupirocin cream in even months. Primary outcomes were ESI and peritonitis. Secondary outcomes were catheter removal or death caused by catheter-related infection. A total of 146 patients (71, gentamicin group; 75, alternating regimen group) were enrolled with a total follow-up duration of 174 and 181 patient-years for gentamicin and alternating groups, respectively. All patients were followed up until catheter removal, death, transfer to another unit, transplantation or the end of the study on March 31, 2014. There were no significant differences in the age, sex, dialysis vintage, and rate of diabetes, helper-assisted dialysis and methicillin-resistant Staphylococcus aureus (MRSA) carriage state. ♦ No difference was seen in the time to first ESI or peritonitis. However, the time to first gram-negative peritonitis seemed longer for the gentamicin group (p = 0.055). The 2 groups showed a similar rate of ESI (0.17/yr vs 0.19/yr, p = 0.93) but P. aeruginosa ESI was less common in the gentamicin group (0.06/yr vs 0.11/yr, p Peritonitis rate was significantly lower in the gentamicin group (0.22/yr vs 0.32/yr, p peritonitis (0.08/yr

Tritium Labeled Gentamicin C: II.- Bioradiactive Degradation Products of Gentamicin by Catalytic H2O-3H Exchange Reaction

International Nuclear Information System (INIS)

Suarez, C.; Diaz, A.; Paz, D.; Jimeno, M. L.

1992-01-01

The main bio radioactive degradation products from catalytic hydrogen exchange of gentamicin C, (C1 + C2 + Cla) in basic form, are generated by N-demethylation in 3 - N and 6-N positions. Their structures were confirmed by 1HNMR and 13CNMR. These derivatives were fractionated by chromatography on silica gel. Antibacterial activities were similar to those of the parent antibiotics. Tritium exchange, under vacuum or nitrogen, is highly increased (4:1) when gentamicin are in basic form. In contrast with gentamicin sulfate, hydrolytic sub products as gramine, genta mines, garosamine and purpurosamines are practically absent. To properly optimize the exchange process, the composition of the gentamicin C complex must be taken into account. The exchange decreases in the order C2 > C1> Cla. Because of 6'-N-demethyl gentamicin C1 is C2, the radiochemical yield of C2 appears enhanced in the H2O-3H exchange of a mixture of them. Radioactivity distribution among the components and subunits of these three gentamicin were studied by strong and mild hydrolysis, and by methanolysis. (Author) 18 refs

Bacteriocin-producing Enterococci from Rabbit Meat

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Szabóová, R.

2012-01-01

Full Text Available Aims: Enterococci are lactic acid bacteria belonging to the division Firmicutes. They occur in different ecosystems, rabbits including. Enterococci can possess probiotic properties and produce antimicrobial substances-bacteriocins. Rabbit meat as nutritionally healthy food offers novel source to study bacteriocin-producing and/or probiotic enterococci. Methodology and results: Enterococci were detected from rabbit meat samples (42. Most of the isolates were allotted to the species Enterococcus faecium by PCR method. The isolates have possessed the structural genes for enterocins A, P, B production. The inhibitory substances produced by the isolated enterococci inhibited the growth of 12 indicators. Of 34 isolates, 15 strains have shown the antimicrobial activity against L. monocytogenes CCM 4699, 12 strains against S. aureus 3A3, 10 strains against S. aureus 5A2 as well as Salmonella enterica serovar Enteritidis PT4. Moreover, enterococci have tolerated 5 % bile, low pH; they have produced lactid acid in the amount from 0.740 ± 0.091 to 1.720 ± 0.095 mmol/l. The isolates were mostly sensitive to antibiotics. Conclusion, significance and impact of study: Bacteriocin-producing strain E. faecium M3a has been selected for more detail characterization of its bacteriocin and probiotic properties with the aim for its further application as an additive.

Diversity and antibiotic susceptibility of autochthonous dairy enterococci isolates: Are they safe candidates for autochthonous starter cultures?

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Amarela eTerzić-Vidojević

2015-09-01

Full Text Available Enterococci represent the most controversial group of dairy bacteria. They are found to be the main constituent of many traditional Mediterranean dairy products and contribute to their characteristic taste and flavor. On the other hand, during the last 50 years antibiotic-resistant enterococci have emerged as leading causes of nosocomial infections worldwide. The aim of this study was to determine the diversity, technological properties, antibiotic susceptibility and virulence traits of 636 enterococci previously isolated from 55 artisan dairy products from 12 locations in the Western Balkan countries of Serbia, Croatia and Bosnia and Herzegovina. All strains were identified both by microbiological and molecular methods. The predominant species was Enterococcus durans, followed by E. faecalis and E. faecium. Over 44% of the isolates were resistant to ciprofloxacin and erythromycin, while 26.2% of the isolates were multi-resistant to three or more antibiotics belonging to different families. 185 isolates (29.1% were susceptible to all 13 of the antibiotics tested. The antibiotic-susceptible isolates were further tested for possible virulence genes and the production of biogenic amines. Finally, five enterococci isolates were found to be antibiotic susceptible with good technological characteristics and without virulence traits or the ability to produce biogenic amines, making them possible candidates for biotechnological application as starter cultures in the dairy industry.

[Enterocin typing of enterococci].

Science.gov (United States)

Sedov, V I

1978-09-01

The author worked out a method of enterocinotyping on enterococci. A possibility of enterococcus typing by means of a set of enterocinogenic enterococcus strains was shown. A mobile enterococcus 4 (10 p) strain, possessing a high antagonistic activity, is suggested for enterococcus identification. Differentiation of enterococcus species by the enterocine sensitivity proved to be impossible.

Hydrogel iontophoresis for gentamicin administration to the rabbit eye

Science.gov (United States)

Eljarrat-Binstock, Esther; Raiskup, Frederik; Frucht-Pery, Joseph; Domb, Abraham J.

2005-04-01

Iontophoresis (IONT) is a non-invasive technique in which a low electric current is used to enhance the penetration of charged molecules into tissue. This technique has been used in various fields of medicine, mostly in transdermal drug delivery. This study was aimed to evaluate the efficacy and the distribution profile of gentamicin using corneal IONT on infected and healthy rabbit eyes. Corneal iontophoresis of gentamicin sulfate was studied using drug-loaded disposable hydrogel probes mounted on a portable iontophoretic device, applying a low current for 60 seconds. This study confirmed that a triple iontophoretic treatment of gentamicin for only 60 seconds (0.5mA) significantly reduces the count of pseudomonas in the infected cornea to a non-infectious level. Peak gentamicin concentrations at the healthy corneas (363.1 +/- 127.3 μg/g) and at the aqueous humor (29.4 +/- 17.4 μg/ml) were reached immediately and two hours after a single iontophoretic treatment, respectively. The concentration versus time profile of gentamicin following iontophoresis revealed a gentamicin half life of 2.07 h in the anterior chamber, and a clearance of 1.73 μl/min from the anterior chamber to the posterior segments of the eye. This study indicates that a short iontophoretic treatment using gentamicin-loaded hydrogels has a potential clinical value in treating corneal infections, by increasing drug penetration to the eye and maintaining therapeutic levels for more than eight hours.

Enterococci in foods--a conundrum for food safety.

Science.gov (United States)

Franz, Charles M A P; Stiles, Michael E; Schleifer, Karl Heinz; Holzapfel, Wilhelm H

2003-12-01

Enterococci form part of the lactic acid bacteria (LAB) of importance in foods. They can spoil processed meats but they are on the other hand important for ripening and aroma development of certain traditional cheeses and sausages, especially those produced in the Mediterranean area. Enterococci are also used as human probiotics. However, they are important nosocomial pathogens that cause bacteraemia, endocarditis and other infections. Some strains are resistant to many antibiotics, but antibiotic resistance alone cannot explain the virulence of some of these bacteria. Virulence factors such as adhesins, invasins and haemolysin have been described. The role of enterococci in disease has raised questions on their safety for use in foods or as probiotics. Studies on the incidence of virulence traits among enterococcal strains isolated from food showed that some harbour virulence traits and generally, Enterococcus faecalis harbours more of them than Enterococcus faecium. Regulations in Europe stipulate that safety of probiotic or starter strains is the responsibility of the producer; therefore, each strain intended for such use should be carefully evaluated. For numerous questions, immediate answers are not fully available. It is therefore suggested that when considering an Enterococcus strain for use as a starter or probiotic culture, it is imperative that each particular strain should be carefully evaluated for the presence of all known virulence factors. Ideally, such strains should harbour no virulence determinants and should be sensitive to clinically relevant antibiotics. In general, E. faecium appears to pose a lower risk for use in foods, because these strains generally harbour fewer recognised virulence determinants than E. faecalis. Generally, the incidence of such virulence determinants among E. faecium strains is low, as compared to E. faecalis strains, probably as a result of the presence of pheromone-responsive plasmids.

Rapid colorimetric assay for gentamicin injection.

Science.gov (United States)

Tarbutton, P

1987-01-01

A rapid colorimetric method for determining gentamicin concentration in commercial preparations of gentamicin sulfate injection was developed. Methods currently available for measuring gentamicin concentration via its colored complex with cupric ions in alkaline solution were modified to reduce the time required for a single analysis. The alkaline copper tartrate (ACT) reagent solution was prepared such that each milliliter contained 100 mumol cupric sulfate, 210 mumol potassium sodium tartrate, and 1.25 mmol sodium hydroxide. The assay involves mixing 0.3 mL gentamicin sulfate injection 40 mg/mL (of gentamicin), 1.0 mL ACT reagent, and 0.7 mL water; the absorbance of the resulting solution at 560 nm was used to calculate the gentamicin concentration in the sample. For injections containing 10 mg/mL of gentamicin, the amount of the injection was increased to 0.5 mL and water decreased to 0.5 mL. The concentration of gentamicin in samples representing 11 lots of gentamicin sulfate injection 40 mg/mL and 8 lots of gentamicin sulfate injection 10 mg/mL was determined. The specificity, reproducibility, and accuracy of the assay were assessed. The colored complex was stable for at least two hours. Gentamicin concentration ranged from 93.7 to 108% and from 95 to 109% of the stated label value of the 40 mg/mL and the 10 mg/mL injections, respectively. No components of the preservative system present in the injections interfered with the assay. Since other aminoglycosides produced a colored complex, the assay is not specific for gentamicin. The assay was accurate and reproducible over the range of 4-20 mg of gentamicin. This rapid and accurate assay can be easily applied in the hospital pharmacy setting.

Isolation, enumeration, molecular identification and probiotic potential evaluation of lactic acid bacteria isolated from sheep milk

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L.B. Acurcio

2014-06-01

Full Text Available Lactic acid bacteria species were molecularly identified in milk from Lacaune, Santa Inês and crossbred sheep breeds and their in vitro probiotic potential was evaluated. The species identified were Enterococcus faecium (56.25%, E. durans (31.25% and E. casseliflavus (12.5%. No other lactic acid bacteria species, such as lactobacilli, was identified. Most of the isolated enterococci were resistant to gastric pH (2.0 and to 0.3% oxgall. All tested enterococci were resistant to ceftazidime, oxacillin and streptomycin and sensible to clindamycin, erythromycin and penicillin. The resistance to ciprofloxacin, gentamicin, tetracycline and vancomycin varied among tested species. All tested enterococci strongly inhibited (P<0.05 Escherichia coli and Listeria monocytogenes, moderately inhibited E. faecalis and Staphylococcus aureus and did not inhibit Pseudomonas aeruginosa, Salmonella enterica var. Typhimurium and also one E. durans sample isolated from sheep milk. Four samples of E. faecium, one of E. durans and one of E. casseliflavus presented the best probiotic potential.

Epidemiology of vancomycin-resistant enterococci in children with acute lymphoblastic leukemia at two referral centers in Tehran, Iran: a descriptive study.

Science.gov (United States)

Nateghian, A; Robinson, J L; Arjmandi, K; Vosough, P; Karimi, A; Behzad, A; Navidnia, M

2011-05-01

Risk factors for colonization with vancomycin-resistant enterococci (VRE) vary by population and locale. The objective of this study was to determine the prevalence of and risk factors for VRE colonization in children with acute lymphoblastic leukemia (ALL) in Tehran. Stools were collected from children with ALL at the Ali Asghar Children's Hospital and the Mahak Pediatric Oncology Center between March 2007 and October 2008. Demographic features and potential risk factors for VRE colonization, including duration of ALL, presence of severe neutropenia in the preceding month, receipt of antibiotics in the preceding 3 months, concurrent medical problems, days of hospitalization, and the need for intensive care since the time of diagnosis of ALL, were recorded. VRE was identified from stools in 33 of 130 children with ALL (25%). No clear risk factors were identified for VRE colonization in the current study, but there was a trend towards an increased prevalence in children admitted to the intensive care unit since their ALL diagnosis (p=0.07). The VanA genotype was found in 28 of the 33 stools (85%), with all other enterococci being VanB. The prevalence of VRE colonization in children with ALL in Tehran is high. Modifiable risk factors have not been identified. The implementation of routine surveillance for colonization and an increased emphasis on adherence to standard infection control precautions may prevent spread. Copyright © 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Vancomycin resistant enterococci in urine cultures: Antibiotic susceptibility trends over a decade at a tertiary hospital in the United Kingdom.

Science.gov (United States)

Toner, Liam; Papa, Nathan; Aliyu, Sani H; Dev, Harveer; Lawrentschuk, Nathan; Al-Hayek, Samih

2016-03-01

Enterococci are a common cause of urinary tract infection and vancomycin-resistant strains are more difficult to treat. The purpose of this surveillance program was to assess the prevalence of and determine the risk factors for vancomycin resistance in adults among urinary isolates of Enterococcus sp. and to detail the antibiotic susceptibility profile, which can be used to guide empirical treatment. From 2005 to 2014 we retrospectively reviewed 5,528 positive Enterococcus sp. urine cultures recorded in a computerized laboratory results database at a tertiary teaching hospital in Cambridge, United Kingdom. Of these cultures, 542 (9.8%) were vancomycin resistant. No longitudinal trend was observed in the proportion of vancomycin-resistant strains over the course of the study. We observed emerging resistance to nitrofurantoin with rates climbing from near zero to 40%. Ampicillin resistance fluctuated between 50% and 90%. Low resistance was observed for linezolid and quinupristin/dalfopristin. Female sex and inpatient status were identified as risk factors for vancomycin resistance. The incidence of vancomycin resistance among urinary isolates was stable over the last decade. Although resistance to nitrofurantoin has increased, it still serves as an appropriate first choice in uncomplicated urinary tract infection caused by vancomycin-resistant Enterococcus sp.

Vancomycin resistant enterococci in urine cultures: Antibiotic susceptibility trends over a decade at a tertiary hospital in the United Kingdom

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Liam Toner

2016-03-01

Full Text Available Purpose: Enterococci are a common cause of urinary tract infection and vancomycin-resistant strains are more difficult to treat. The purpose of this surveillance program was to assess the prevalence of and determine the risk factors for vancomycin resistance in adults among urinary isolates of Enterococcus sp. and to detail the antibiotic susceptibility profile, which can be used to guide empirical treatment. Materials and Methods: From 2005 to 2014 we retrospectively reviewed 5,528 positive Enterococcus sp. urine cultures recorded in a computerized laboratory results database at a tertiary teaching hospital in Cambridge, United Kingdom. Results: Of these cultures, 542 (9.8% were vancomycin resistant. No longitudinal trend was observed in the proportion of vancomycin- resistant strains over the course of the study. We observed emerging resistance to nitrofurantoin with rates climbing from near zero to 40%. Ampicillin resistance fluctuated between 50% and 90%. Low resistance was observed for linezolid and quinupristin/ dalfopristin. Female sex and inpatient status were identified as risk factors for vancomycin resistance. Conclusions: The incidence of vancomycin resistance among urinary isolates was stable over the last decade. Although resistance to nitrofurantoin has increased, it still serves as an appropriate first choice in uncomplicated urinary tract infection caused by vancomycin- resistant Enterococcus sp.

Effect of nettle (Urtica dioica extract on gentamicin induced nephrotoxicity in male rabbits

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Nadia Abdulkarim Salih

2015-09-01

Conclusions: Therefore, it can be assumed that the nephroprotective effect shown by nettle in gentamicin-induced nephrotoxicity can reserve intracellular levels of biological pathways and supportively enhance excretion of toxic levels of gentamicin.

Significance and survival of Enterococci during the house fly development.

Science.gov (United States)

Ghosh, Anuradha; Akhtar, Mastura; Holderman, Chris; Zurek, Ludek

2014-01-01

House flies are among the most important nonbiting insect pests of medical and veterinary importance. Larvae develop in decaying organic substrates and their survival strictly depends on an active microbial community. House flies have been implicated in the ecology and transmission of enterococci, including multi-antibiotic-resistant and virulent strains of Enterococcus faecalis. In this study, eight American Type Culture Collection type strains of enterococci including Enterococcus avium, Enterococcus casseliflavus, Enterococcus durans, Enterococcus hirae, Enterococcus mundtii, Enterococcus gallinarum, Enterococcusfaecalis, and Enterococcusfaecium were evaluated for their significance in the development of house flies from eggs to adults in bacterial feeding assays. Furthermore, the bacterial colonization of the gut of teneral flies as well as the importance of several virulence traits of E. faecalis in larval mortality was assessed. Overall survival of house flies (egg to adult) was significantly higher when grown with typically nonpathogenic enterococcal species such as E. hirae (76.0% survival), E. durans (64.0%), and E. avium (64.0%) compared with that with clinically important species E. faecalis (24.0%) and E. faecium (36.0%). However, no significant differences in survival of house fly larvae were detected when grown with E. faecalis strains carrying various virulence traits, including isogenic mutants of the human clinical isolate E. faecalis V583 with in-frame deletions of gelatinase, serine protease, and capsular polysaccharide serotype C. Enterococci were commonly detected in fly puparia (range: 75-100%; concentration: 103-105 CFU/puparium);however, the prevalence of enterococci in teneral flies varied greatly: from 25.0 (E. casseliflavus) to 89.5% (E. hirae). In conclusion, depending on the species, enterococci variably support house fly larval development and colonize the gut of teneral adults. The human pathogenic species, E. faecalis and E. faecium

Agmatine improves renal function in gentamicin-induced nephrotoxicity in rats.

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El-Kashef, Dalia H; El-Kenawi, Asmaa E; Abdel Rahim, Mona; Suddek, Ghada M; Salem, Hatem A

2016-03-01

The present study was designed to explore the possible protective effects of agmatine, a known nitric oxide (NO) synthase inhibitor, against gentamicin-induced nephrotoxicity in rats. For this purpose, we quantitatively evaluated gentamicin-induced renal structural and functional alterations using histopathological and biochemical approaches. Furthermore, the effect of agmatine on gentamicin-induced hypersensitivity of urinary bladder rings to acetylcholine (ACh) was evaluated. Twenty-four male Wistar albino rats were randomly divided into 3 groups, namely control, gentamicin (100 mg/kg, i.p.), and gentamicin plus agmatine (40 mg/kg, orally). At the end of the study, all rats were sacrificed and then blood and urine samples and kidneys were taken. Administration of agmatine significantly decreased kidney/body mass ratio, serum creatinine, lactate dehydrogenase (LDH), renal malondialdehyde (MDA), myeloperoxidase (MPO), NO, and tumor necrosis factor-alpha (TNF-α) while it significantly increased creatinine clearance and renal superoxide dismutase (SOD) activity when compared with the gentamicin-treated group. Additionally, agmatine ameliorated tissue morphology as evidenced by histological evaluation and reduced the responses of isolated bladder rings to ACh. Our study indicates that agmatine administration with gentamicin attenuates oxidative-stress associated renal injury by reducing oxygen free radicals and lipid peroxidation, restoring NO level and inhibiting inflammatory mediators such as TNF-α.

Association of the novel aminoglycoside resistance determinant RmtF with NDM carbapenemase in Enterobacteriaceae isolated in India and the UK

DEFF Research Database (Denmark)

Hidalgo, Laura; Hopkins, Katie L; Gutierrez, Belen

2013-01-01

16S rRNA methyltransferases are an emerging mechanism conferring high-level resistance to clinically relevant aminoglycosides and have been associated with important mechanisms such as NDM-1. We sought genes encoding these enzymes in isolates highly resistant (MIC >200 mg/L) to gentamicin and ami...

Combination antibiotic therapy for the treatment of infective endocarditis due to enterococci.

Science.gov (United States)

Leone, Sebastiano; Noviello, Silvana; Esposito, Silvano

2016-06-01

Enterococci are common causes of infective endocarditis (IE) in both health care and community-based setting. Enterococcal IE requires bactericidal therapy for an optimal outcome. For decades, cell-wall-active antimicrobial agents (penicillins or vancomycin) in combination with aminoglycosides were the cornerstone of the treatment; however, the emergence of antibiotic resistance has significantly reduced the efficacy of these regimens. Data for this review were identified by searches of MEDLINE and references from relevant articles on antibiotic combination regimens for the treatment of enterococcal IE. Abstracts presented in scientific conferences were not searched for. New effective and safe combination treatments, including double-β-lactam and daptomycin/β-lactam combination, are proving useful for the management of IE due to enterococci.

Bactericidal Effect of Pterostilbene Alone and in Combination with Gentamicin against Human Pathogenic Bacteria.

Science.gov (United States)

Lee, Wee Xian; Basri, Dayang Fredalina; Ghazali, Ahmad Rohi

2017-03-17

The antibacterial activity of pterostilbene in combination with gentamicin against six strains of Gram-positive and Gram-negative bacteria were investigated. The minimum inhibitory concentration and minimum bactericidal concentration of pterostilbene were determined using microdilution technique whereas the synergistic antibacterial activities of pterostilbene in combination with gentamicin were assessed using checkerboard assay and time-kill kinetic study. Results of the present study showed that the combination effects of pterostilbene with gentamicin were synergistic (FIC index bacteria strains: Staphylococcus aureus ATCC 25923 , Escherichia coli O157 and Pseudomonas aeruginosa 15442 . However, the time-kill study showed that the interaction was indifference which did not significantly differ from the gentamicin treatment. Furthermore, time-kill study showed that the growth of the tested bacteria was completely attenuated with 2 to 8 h treatment with 0.5 × MIC of pterostilbene and gentamicin. The identified combinations could be of effective therapeutic value against bacterial infections. These findings have potential implications in delaying the development of bacterial resistance as the antibacterial effect was achieved with the lower concentrations of antibacterial agents.

[Microbiological and epidemiological characteristics of vancomycin-dependent enterococci].

Science.gov (United States)

Hwang, Keumrock; Sung, Heungsup; Namgoong, Seung; Yoon, Nam Surp; Kim, Mi-Na

2009-08-01

Vancomycin-dependent enterococci (VDE) are clinically equivalent to vancomycin-resistant enterococci (VRE), but more difficult to detect. This study was purposed to characterize VDE microbiologically and epidemiologically. The patients from whom VDE were detected from April 2007 to March 2008 were investigated. For available isolates, minimal inhibitory concentrations (MICs) of and the levels of dependence on vancomycin and teicoplanin were measured by E test (AB Biodisk, Sweden), and a test for reversion of VDE to non-dependent VRE (NDVRE) and pulsed field gel electrophoresis (PFGE) were performed. Patients' demographic and clinical findings were reviewed via electronic medical records. VDE were recovered from 6 (2.2%) of 272 patients carrying VRE during this study period. All patients were already colonized or infected by VRE and treated with vancomycin for 13 to 107 days. VDE were isolated from pleural fluid (one), urine (four), and stool (one). All isolates carried vanA with vancomycin MICs of >256 microg/mL, but two of them had intermediate susceptibilities to teicoplanin. Because 4 VDE isolates were reverted to NDVRE with single passage, vancomycin dependence was measurable for only two isolates as equal and above 0.064 and 0.5 microg/mL respectively, and was reverted after 5 and 7 passages, respectively. Six VDE isolates showed no related clones in PFGE analysis, and 3 of 4 available pairs of initial VRE isolates and subsequent VDE isolates were identical clones. VDE were not rare and seemed to emerge independently from VRE with a prolonged use of vancomycin. Vancomycin-dependence was reverted within several passages.

Performance characteristics of bioassay, radioenzymatic assay, homogeneous enzyme immunoassay, and high-performance liquid chromatographic determination of serum gentamicin

International Nuclear Information System (INIS)

Delaney, C.J.; Opheim, K.E.; Smith, A.L.; Plorde, J.J.

1982-01-01

We compared the accuracy, precision, and between-method error of the microbiological assay, the radioenzymatic assay, the homogeneous enzyme immunoassay, and the high-performance liquid chromatographic assay for the quantitation of gentamicin in serum. Precision and accuracy were evaluated by reference samples prepared to contain 0.0 to 32.7 micrograms of gentamicin per ml. Correlations between the methods utilized patient sera with gentamicin concentrations ranging from 0.6 to 13.3 micrograms/ml. All methods were reliable within acceptable limits for routine clinical use; intermethod correlation coefficients exceeded 0.96. Relative to the microbiological assay, the alternative methods offer the advantage of rapid analysis. The elapsed times for acquiring data on a set of 10 specimens under routine operating conditions were 0.5 h by the enzyme immunoassay, 4 h by the radioenzymatic assay, 5 h by the high-performance liquid chromatographic assay, and 10 h by the microbiological assay

Auditory function after continuous infusion of gentamicin to high-risk newborns

DEFF Research Database (Denmark)

Colding, H; Andersen, E A; Prytz, S

1989-01-01

Audiometry was performed at four years of age in 69 of 105 surviving children who had received continuous intravenous infusion of gentamicin during neonatal intensive care. A hearing loss of 20 dB was found in 2 of them (3%), corresponding to that shown in other studies of survivors following...... neonatal intensive care. Free field audiometry performed in another 7 children and questionnaires returned from 13 of the remaining 29 gave no suspicion of hearing loss. Thus there is no indication that continuous 24 hours intravenous infusion of gentamicin causes more hearing impairment than intermittent...

Susceptibility to disinfectants in antimicrobial-resistant and -susceptible isolates of Escherichia coli, Enterococcus faecalis and Enterococcus faecium from poultry-ESBL/AmpC-phenotype of E. coli is not associated with resistance to a quaternary ammonium compound, DDAC.

Science.gov (United States)

Wieland, N; Boss, J; Lettmann, S; Fritz, B; Schwaiger, K; Bauer, J; Hölzel, C S

2017-06-01

The spread of bacteria that are simultaneously resistant to disinfectants and antimicrobials would constitute an unsettling scenario. In order to explore an association between antimicrobial resistance and reduced susceptibility to biocides/microbicides (disinfectants) in agriculture, we investigated Escherichia coli (n = 438) and enterococci (n = 120) isolated from six different flocks of the same poultry farm with known history of antimicrobial treatment. Susceptibility to disinfectants (formic acid and a quaternary ammonium compound (QAC), didecyldimethylammoniumchloride-DDAC) was assessed by macrodilution according to guidelines of the German Veterinary Society. Escherichia coli, Enterococcus faecalis and Enterococcus faecium were screened (i) for reduced biocide susceptibility and (ii) for an association of biocide susceptibility and antimicrobial resistance including the production of extended-spectrum beta-lactamases (ESBL) and the hyperproduction of AmpC-type beta-lactamases. DDAC inhibited ESBL/AmpC(hyper)-producing E. coli (n = 53) from poultry at similar or slightly lower inhibitory concentrations, compared with non-ESBL/AmpC strains (median MIC = 0·36 vs 1·44 mg l -1 ). In contrast, DDAC-MICs were positively correlated with several other antibiotic MICs (e.g. piperacillin and sulphamethoxazole + trimethoprim in E. coli, chloramphenicol in E. faecalis) and increased DDAC-MICs were statistically linked to high-level aminoglycoside resistance in enterococci (streptomycin high level). DDAC-MICs did not correlate with the presence of the integron marker qacEDelta1. This study provides indication that residual disinfectant might be able to select antimicrobial-resistant enterococci, but not ESBL-/AmpC (hyper)producing E. coli from poultry. While ESBL-/AmpC-E. coli were inhibited at disinfectant concentrations comparable to or lower than wildtype values, low concentrations of QACs might be able to select other antimicrobial-resistant E

Characterisation, dissemination and persistence of gentamicin resistant Escherichia coli from a Danish university hospital to the waste water environment

DEFF Research Database (Denmark)

Jakobsen, Lotte; Sandvang, Dorthe; Hansen, Lars H

2008-01-01

The aim of the study was to investigate the potential spread of gentamicin resistant (GEN(R)) Escherichia coli isolates or GEN(R) determinants from a Danish university hospital to the waste water environment. Waste water samples were collected monthly from the outlets of the hospital bed wards...... (aac(3)-II, aac(3)-IV, ant(2'')-I, armA), phenotypic resistance pattern, and virulence genes (hlyA, chuA, sfaS, fogG, malX, traT, iutA, fyuA, iroN, cnf1) to investigate if the hospital and waste water could be reservoirs of antimicrobial resistance and virulence. The ability for GEN(R) determinants......, indicating a potential spread of the gene from patient isolates to waste water isolates. Regardless of origin, most isolates exhibited multi-resistance and contained several virulence genes. In conclusion, our study showed a possible spread of aac(3)-II from the hospital to the waste water. Most of the GEN...

Efficacy of Tigecycline Alone and in Combination with Gentamicin in the Treatment of Experimental Endocarditis Due to Linezolid-Resistant Enterococcus faecium

OpenAIRE

Pontikis, Konstantinos; Pefanis, Angelos; Tsaganos, Thomas; Tzepi, Ira-Maria; Carrer, Dionyssia-Pinelopi; Giamarellou, Helen

2013-01-01

We evaluated the efficacy of tigecycline in a rabbit model of experimental endocarditis caused by a linezolid-resistant clinical strain of Enterococcus faecium. Tigecycline-treated animals had a 2.8-log10-CFU/g reduction in microbial counts in excised vegetations compared with controls. Addition of gentamicin caused a further arithmetical reduction in colony counts. The therapeutic effect was sustained 5 days after completion of treatment, as shown by relapse studies performed in treatment gr...

Efficacy of tigecycline alone and in combination with gentamicin in the treatment of experimental endocarditis due to linezolid-resistant Enterococcus faecium.

Science.gov (United States)

Pontikis, Konstantinos; Pefanis, Angelos; Tsaganos, Thomas; Tzepi, Ira-Maria; Carrer, Dionyssia-Pinelopi; Giamarellou, Helen

2013-07-01

We evaluated the efficacy of tigecycline in a rabbit model of experimental endocarditis caused by a linezolid-resistant clinical strain of Enterococcus faecium. Tigecycline-treated animals had a 2.8-log10-CFU/g reduction in microbial counts in excised vegetations compared with controls. Addition of gentamicin caused a further arithmetical reduction in colony counts. The therapeutic effect was sustained 5 days after completion of treatment, as shown by relapse studies performed in treatment groups.

Tauroursodeoxycholic acid attenuates gentamicin-induced cochlear hair cell death in vitro.

Science.gov (United States)

Jia, Zhanwei; He, Qiang; Shan, Chunguang; Li, Fengyi

2018-09-15

Gentamycin is one of the most clinically used aminoglycoside antibiotics which induce intrinsic apoptosis of hair cells. Tauroursodeoxycholic acid (TUDCA) is known as safe cell-protective agent in disorders associated with apoptosis. We aimed to investigate the protective effects of TUDCA against gentamicin-induced ototoxicity. House Ear Institute-Organ of Corti 1(HEI-OC1) cells and explanted cochlear tissue were treated with gentamicin and TUDCA, followed by serial analyses including cell viability assay, hair cell staining, qPCR, ELISA and western blotting to determine the cell damage by the parameters relevant to cell apoptosis and endoplasmic reticulum stress. TUDCA significantly attenuated gentamicin-induced cell damage in cultured HEI-OC1 cells and explanted cochlear hair cells. TUDCA alleviated gentamicin-induced cell apoptosis, supported by the decreased Bax/Bcl2 ratio compared with that of gentamicin treated alone. TUDCA decreased gentamicin-induced nitric oxide production and protein nitration in both models. In addition, TUDCA suppressed gentamicin-induced endoplasmic reticulum stress as reflected by inversing the expression levels of Binding immunoglobulin protein (Bip), CCAAT/-enhancer-binding protein homologous protein (CHOP) and Caspase 3. TUDCA attenuated gentamicin-induced hair cell death by inhibiting protein nitration activation and ER stress, providing new insights into the new potential therapies for sensorineural deafness. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of Gentamicin on Urinary Electrolyte Excretion in Admitted Neonate

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B. Falakolaflaki

2008-01-01

Full Text Available Introduction & Objective: Gentamicin is an aminoglycoside antibiotic widely used during the neonatal period. It is associated with nephrotoxic effects in neonates, including glomerular impairment and renal tubular dysfunction. Electrolyte balance is very important, especially in the sick premature neonate receiving aminoglycosides. The purpose of this study was early diagnosis of gentamicin nephrotoxicity. Materials & Methods: This quasi-experimental study was performed on 23 neonates (11 full – term and 12 preterm with suspected sepsis who were admitted and treated with gentamicin. Blood and urine samples were collected before infusion and on the 3rd day of treatment. Serum and urine concentration of Na, K, creatinine (Cr and urine concentration of Ca were measured. Then fractional excretion of Na and K were estimated. Ca excretion was estimated as the UCa/UCr ratio. Then the collected data were analyzed using SPSS package.Results: In all neonates, increase in fractional excretion of Na and UCa/UCr, in the 3rd day of treatment were observed as compared to those of before infusion (P=0.01 and P=0.02 respectively. Serum creatinine levels decreased in all patients. Serum level of electrolytes during therapy was normal.Conclusion: The results of this study clearly demonstrate an effect of gentamicin infusion on renal sodium and calcium excretion. These results may be of clinical importance especially for sick preterm neonates receiving treatment with gentamicin. These babies are usually salt-losers and are also more susceptible to early onset hypocalcemia. Gentamicin can aggravate these complications.

Compound list: gentamicin [Open TG-GATEs

Lifescience Database Archive (English)

Full Text Available gentamicin GMC 00147 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vitro/gentam...icin.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Single/gentam...at/in_vivo/Liver/Repeat/gentamicin.Rat.in_vivo.Liver.Repeat.zip ftp://ftp.bioscie...ncedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Kidney/Single/gentamicin.Rat.in_vivo.Kidney.Single.zip ftp...://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Kidney/Repeat/gentamicin.Rat.in_vivo.Kidney.Repeat.zip ...

Antimicrobial resistance 1979-2009 at Karolinska hospital, Sweden: normalized resistance interpretation during a 30-year follow-up on Staphylococcus aureus and Escherichia coli resistance development.

Science.gov (United States)

Kronvall, Göran

2010-09-01

To utilize a material of inhibition zone diameter measurements from disc diffusion susceptibility tests between 1979 and 2009, an objective setting of epidemiological breakpoints was necessary because of methodological changes. Normalized resistance interpretation (NRI) met this need and was applied to zone diameter histograms for Staphylococcus aureus and Escherichia coli isolates. The results confirmed a slow resistance development as seen in Northern countries. The S. aureus resistance levels for erythromycin, clindamycin and fusidic acid in 2009 were 3.2%, 1.8% and 1.4% with denominator correction. A rise in resistance to four antimicrobials in 1983 was probably because of a spread of resistant Methicillin Susceptible Staphylococcus Aureus (MSSA). For E. coli, the denominator-corrected resistance levels in 2009 were 27% for ampicillin, around 3% for third-generation cephalosporins, 0.1% for imipenem, 2.5% for gentamicin, 19% for trimethoprim, 4.5% for co-trimoxazole, 1.2% for nitrofurantoin and 9% for ciprofloxacin. The temporal trends showed a rise in fluoroquinolone resistance from 1993, a parallel increase in gentamicin resistance, a substantial increase in trimethoprim and sulphonamide resistance in spite of decreased consumption, and a steady rise in ampicillin resistance from a constant level before 1989. A short review of global resistance surveillance studies is included.

Persistence of bacterial pathogens, antibiotic resistance genes, and enterococci in tidal creek tributaries.

Science.gov (United States)

Jones, Chance E; Maddox, Anthony; Hurley, Dorset; Barkovskii, Andrei L

2018-05-19

Intertidal creeks form the primary hydrologic link between estuaries and land-based activities on barrier islands. Fecal indicators Enterococcus spp. (Entero1), pathogens Shigella spp. (ipaH), Salmonella spp. (invA), E. coli of EHEC/EPEC groups (eaeA), E. coli of EAEC, EIEC, and UPEC groups (set1B), E. coli of STEC group (stx1); and tetracycline resistance genes (tet(B), tet(C), tet(D), tet(E), tet(K), tet(Q), tet(W), and tet(X); TRG) were detected in the headwater of Oakdale Creek (Sapelo Island, GA) receiving runoffs from Hog Hammock village. Excavation of drainage ditches around the village caused a high increase in the incidence of the above determinants. Water samples were collected from the headwater, transferred to diffusion chambers, submersed in the headwater, saltmarsh, and mouth of the creek; and the determinants were monitored for 3 winter months. With some exceptions, their persistence decreased in order headwater > saltmarsh > mouth. Genes associated with Enterococcus spp. were the most persistent at all the sites, following in the headwater with determinants for Salmonella spp. and E. coli of EAEC, EIEC, and UPEC groups. In the mouth, the most persistent gene was eaeA indicating EHEC, EPEC, and STEC. Tet(B) and tet(C) persisted the longest in headwater and saltmarsh. No TRG persisted after 11 days in the mouth. Most determinants revealed correlations with temperature and pH, and inverse correlations with dissolved oxygen. Decay rates of the above determinants varied in the range of -0.02 to -0.81/day, and were up to 40 folds higher in the saltmarsh and mouth than in the headwater. Our data demonstrated that water parameters could to some extent predict a general trend in the fate of virulence and antibiotic resistance determinants in tidal creek tributaries but strongly suggested that their persistence in these tributaries cannot be predicted from that of enterococci, or extrapolated from one biological contaminant to another. Copyright

Human isolates of Salmonella enterica serovar Typhimurium from Taiwan displayed significantly higher levels of antimicrobial resistance than those from Denmark.

Science.gov (United States)

Torpdahl, Mia; Lauderdale, Tsai-Ling; Liang, Shiu-Yun; Li, Ishien; Wei, Sung-Hsi; Chiou, Chien-Shun

2013-02-01

Salmonella enterica serovar Typhimurium is a major zoonotic pathogen with a high prevalence of antimicrobial resistance. This pathogen can disseminate across borders and spread far distances via the food trade and international travel. In this study, we compared the genotypes and antimicrobial resistance of 378 S. Typhimurium isolates collected in Taiwan and Denmark between 2009 and 2010. Genotyping revealed that many S. Typhimurium strains were concurrently circulating in Taiwan, Denmark and other countries in 2009 and 2010. When compared to the isolates collected from Denmark, the isolates from Taiwan displayed a significantly higher level of resistance to 11 of the 12 tested antimicrobials. Seven genetic clusters (A-G) were designated for the isolates. A high percentage of the isolates in genetic clusters C, F and G were multidrug-resistant. Of the isolates in cluster C, 79.2% were ASSuT-resistant, characterized by resistance to ampicillin, streptomycin, sulfamethoxazole, and tetracycline. In cluster F, 84.1% of the isolates were ACSSuT-resistant (resistant to ASSuT and chloramphenicol). Cluster G was unique to Taiwan and characterized in most isolates by the absence of three VNTRs (ST20, ST30 and STTR6) as well as a variety of multidrug resistance profiles. This cluster exhibited very high to extremely high levels of resistance to several first-line drugs, and among the seven clusters, it displayed the highest levels of resistance to cefotaxime and ceftazidime, ciprofloxacin and gentamicin. The high prevalence of antimicrobial resistance in S. Typhimurium from Taiwan highlights the necessity to strictly regulate the use of antimicrobials in the agriculture and human health care sectors. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of rifampicin and gentamicin on Shiga toxin 2 expression level and the SOS response in Escherichia coli O104:H4.

Science.gov (United States)

Fadlallah, Sukayna M; Rahal, Elias A; Sabra, Ahmad; Kissoyan, Kohar A B; Matar, Ghassan M

2015-01-01

A novel pathotype, Shiga toxin-producing Escherichia coli O104:H4, was the cause of a severe outbreak that affected European countries, mainly Germany, in 2011. The effect of different regimens of rifampicin and gentamicin were evaluated to determine possible treatment modes for the novel strain, and to evaluate the SOS response and its effect on toxin release. Pulsed-field gel electrophoresis (PFGE) was performed on the novel E. coli O104:H4 pathotype and two pre-outbreak E. coli O104:H4 CDC strains. Transcript levels of the stx2 and recA gene (SOS response inducer) were evaluated using quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) in the novel E. coli O104:H4 samples subjected to different regimens of rifampicin and gentamicin. Consequently, reverse passive latex agglutination (RPLA) was used to determine the Stx2 titers in these samples. Western blot was performed to determine the LexA levels (SOS response repressor) in E. coli O104:H4. The efficacy of treatment with antimicrobial agents was assessed in BALB/c mice. The outbreak and pre-outbreak strains are closely related as shown by PFGE, which demonstrated slight genomic differences between the three strains. The transcription level of the stx2 gene in the new pathotype was 1.41- and 1.75-fold that of the 2009 EL-2050 and 2009 EL-2071 pre-outbreak strains, respectively. Moreover, the transcription level of the stx2 gene in the new pathotype was substantially decreased as a result of treatment with the different concentrations of the antimicrobial agents, but was enhanced when the antibiotics were administered at two subinhibitory levels. RPLA data were in accordance with the qRT-PCR results. E. coli O104:H4 exposed to gentamicin at both sub-minimum inhibitory concentration (MIC) levels led to high transcription levels of the recA gene and lack of expression of the LexA protein, implying that the SOS response was activated. Rifampicin at both sub-MIC levels resulted in low

Bactericidal Effect of Pterostilbene Alone and in Combination with Gentamicin against Human Pathogenic Bacteria

Directory of Open Access Journals (Sweden)

Wee Xian Lee

2017-03-01

Full Text Available The antibacterial activity of pterostilbene in combination with gentamicin against six strains of Gram-positive and Gram-negative bacteria were investigated. The minimum inhibitory concentration and minimum bactericidal concentration of pterostilbene were determined using microdilution technique whereas the synergistic antibacterial activities of pterostilbene in combination with gentamicin were assessed using checkerboard assay and time-kill kinetic study. Results of the present study showed that the combination effects of pterostilbene with gentamicin were synergistic (FIC index < 0.5 against three susceptible bacteria strains: Staphylococcus aureus ATCC 25923, Escherichia coli O157 and Pseudomonas aeruginosa 15442. However, the time-kill study showed that the interaction was indifference which did not significantly differ from the gentamicin treatment. Furthermore, time-kill study showed that the growth of the tested bacteria was completely attenuated with 2 to 8 h treatment with 0.5 × MIC of pterostilbene and gentamicin. The identified combinations could be of effective therapeutic value against bacterial infections. These findings have potential implications in delaying the development of bacterial resistance as the antibacterial effect was achieved with the lower concentrations of antibacterial agents.

Comparative activities of telavancin combined with nafcillin, imipenem, and gentamicin against Staphylococcus aureus.

Science.gov (United States)

Leonard, Steven N; Supple, Megan E; Gandhi, Ronak G; Patel, Meghna D

2013-06-01

Beta-lactams enhance the killing activity of vancomycin. Due to structural and mechanistic similarities between vancomycin and telavancin, we investigated the activity of telavancin combined with nafcillin and imipenem compared to the known synergistic combination of telavancin and gentamicin. Thirty strains of Staphylococcus aureus, 10 methicillin-susceptible S. aureus (MSSA), 10 methicillin-resistant S. aureus (MRSA), and 10 heterogeneously vancomycin-intermediate S. aureus (hVISA), were tested for synergy by time-kill methodology. Six strains (2 each of MSSA, MRSA, and hVISA) were further evaluated in an in vitro pharmacokinetic/pharmacodynamic (PK/PD) model with simulated regimens of 10 mg/kg of body weight of telavancin once daily alone and combined with 2 g nafcillin every 4 h, 500 mg imipenem every 6 h, or 5 mg/kg gentamicin once daily over 72 h. In the synergy test, 67% of strains displayed synergy with the combination of telavancin and gentamicin, 70% with telavancin and nafcillin, and 63% with telavancin and imipenem. In the PK/PD model, the activities of all three combinations against MRSA and hVISA were superior to all individual drugs alone (P ≤ 0.002) and were similar to each other (P ≥ 0.187). The activities of all three combinations against MSSA were generally similar to each other except for one strain where the combination of telavancin and imipenem was superior to all other regimens (P ≤ 0.011). The activity of the combination of telavancin and beta-lactam agents was similar to that of telavancin and gentamicin against S. aureus, including resistant strains. Because beta-lactam combinations are less likely to be nephrotoxic than telavancin plus gentamicin, these beta-lactam combinations may have clinical utility.

Residual gentamicin-release from antibiotic-loaded polymethylmethacrylate beads after 5 years of implantation

NARCIS (Netherlands)

Neut, D; van de Belt, H; van Horn, [No Value; van der Mei, HC; Busscher, HJ

In infected joint arthroplasty, high local levels of antibiotics are achieved through temporary implantation of non-biodegradable gentamicin-loaded polymethylmethacrylate beads. Despite their antibiotic release, these beads act as a biomaterial surface to which bacteria preferentially adhere, grow

Clinicopathological Studies on Gentamicin Toxicity in White Leghorn Commercial Layers

Directory of Open Access Journals (Sweden)

Najam Ul Islam, M. Zargham Khan1, M. Kashif Saleemi*1, Ahrar Khan1, Sheraz Ahmed Bhatti1, Muhammad Yousaf2 and Zahoor-ul-Hassan3

2011-10-01

Full Text Available Gentamicin is an effective and economical drug used to control infectious diseases in poultry but is highly toxic and had slow clearance from the body. This study aimed to report three cases of gentamicin toxicity in three White Leghorn (WLH layer flocks in different poultry producing areas of Pakistan. In first case, gentamicin was injected in a 9000 WLH layer flock @ 10 mg/kg body weight (BW for seven times during 9-15 weeks for age. In second case, gentamicin was injected in a flock of 7500 WLH layers @ 25 mg/kg BW for four times during 17-18 weeks of age. In third case, gentamicin was injected in flock of 16000 WLH layers @ 22.22 mg/kg BW three times in 20-21 weeks of age. Flock wise mortality was 8.69, 82.63 and 71.86%, respectively. Birds were dehydrated, emaciated and had prominent keel bone. Clinical signs included dehydration, decreased body weight leading to emaciation, decreased feed intake, increased water intake and watery diarrhea. Necropsy revealed prominent keal bone, shrunken muscles swollen kidneys bulging out from bony sockets. Petechial and echymotic hemorrhages were present on heart and skeletal muscles. Liver was enlarged with hemorrhagic streaks on its surface. Microscopically, hemorrhages and acute tubular necrosis was recorded in kidneys. Liver had hemorrhages, cellular infiltration and vacuolar (fatty degeneration of hepatocytes. From the results, it could be concluded that overdosing and repeated administration of gentamicin was highly toxic to birds.

Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae

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Cynthia Annes Rubião

2017-08-01

Full Text Available ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN of Total Coliforms (TC, Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several antimicrobial resistance genes to pathogenic bacteria, including those from Gram-negative group. The oysters were bought from local fishermen and a total of 123 individuals were analyzed. The TC, E. coli and Enterococcus spp. MPN mean were 26,300/100 g, 3,260/100 g and 2,820/100 g, respectively. The only correlation found was between TC and E. coli. Two strains of Enterococcus spp. were resistant to three different antimicrobial categories, including a high level resistance to streptomycin. One strain presented intermediate resistance to vancomycin. The E. coli levels exceeded the limits established by international legislation. This microbiological contamination in oysters reflects the water pollution and indicates a probable contamination of other seafood species from this mangrove, which can represent a risk for consumers and a threat to the environment and public health.

Removal of total and antibiotic resistant bacteria in advanced wastewater treatment by ozonation in combination with different filtering techniques.

Science.gov (United States)

Lüddeke, Frauke; Heß, Stefanie; Gallert, Claudia; Winter, Josef; Güde, Hans; Löffler, Herbert

2015-02-01

Elimination of bacteria by ozonation in combination with charcoal or slow sand filtration for advanced sewage treatment to improve the quality of treated sewage and to reduce the potential risk for human health of receiving surface waters was investigated in pilot scale at the sewage treatment plant Eriskirch, Baden-Wuerttemberg/Germany. To determine the elimination of sewage bacteria, inflowing and leaving wastewater of different treatment processes was analysed in a culture-based approach for its content of Escherichia coli, enterococci and staphylococci and their resistance against selected antibiotics over a period of 17 month. For enterococci, single species and their antibiotic resistances were identified. In comparison to the established flocculation filtration at Eriskirch, ozonation plus charcoal or sand filtration (pilot-scale) reduced the concentrations of total and antibiotic resistant E. coli, enterococci and staphylococci. However, antibiotic resistant E. coli and staphylococci apparently survived ozone treatment better than antibiotic sensitive strains. Neither vancomycin resistant enterococci nor methicillin resistant Staphylococcus aureus (MRSA) were detected. The decreased percentage of antibiotic resistant enterococci after ozonation may be explained by a different ozone sensitivity of species: Enterococcus faecium and Enterococcus faecalis, which determined the resistance-level, seemed to be more sensitive for ozone than other Enterococcus-species. Overall, ozonation followed by charcoal or sand filtration led to 0.8-1.1 log-units less total and antibiotic resistant E. coli, enterococci and staphylococci, as compared to the respective concentrations in treated sewage by only flocculation filtration. Thus, advanced wastewater treatment by ozonation plus charcoal or sand filtration after common sewage treatment is an effective tool for further elimination of microorganisms from sewage before discharge in surface waters. Copyright © 2014 Elsevier

Evaluation of nephroprotective activity of Musa paradisiaca L. in gentamicin-induced nephrotoxicity.

Science.gov (United States)

Abbas, Khizar; Rizwani, Ghazala H; Zahid, Hina; Qadir, M Imran

2017-05-01

The objective of the study was to investigate the nephroprotective activity of methanolic extract of different morphological parts (bract, flower, trachea and tracheal fluid) of Musa paradisiaca L. (Family: Musaceae) against gentamicin-induced nephrotoxicity in mice. Gentamicin produced significant changes in biochemical (increased levels of blood urea nitrogen level, blood urea, and serum creatinine), and histological parameters in mice. Treatment with methanolic extract of bract (100 and 250mg/kg, b.w) and flowering stalk (trachea) (250 and 500mg/kg, b.w) significantly prevented biochemical and histological changes produced by gentamicin toxicity. The extracts of M. paradisiaca (bract and flowering stalk) could contribute a lead to discovery of a new drug for the treatment of drug-induced nephrotoxicity.

The use of high-throughput sequencing to investigate an outbreak of glycopeptide-resistant Enterococcus faecium with a novel quinupristin-dalfopristin resistance mechanism.

Science.gov (United States)

Shaw, Timothy D; Fairley, D J; Schneiders, T; Pathiraja, M; Hill, R L R; Werner, G; Elborn, J S; McMullan, R

2018-02-24

High-throughput sequencing (HTS) has successfully identified novel resistance genes in enterococci and determined clonal relatedness in outbreak analysis. We report the use of HTS to investigate two concurrent outbreaks of glycopeptide-resistant Enterococcus faecium (GRE) with an uncharacterised resistance mechanism to quinupristin-dalfopristin (QD). Seven QD-resistant and five QD-susceptible GRE isolates from a two-centre outbreak were studied. HTS was performed to identify genes or predicted proteins that were associated with the QD-resistant phenotype. MLST and SNP typing on HTS data was used to determine clonal relatedness. Comparative genomic analysis confirmed this GRE outbreak involved two distinct clones (ST80 and ST192). HTS confirmed the absence of known QD resistance genes, suggesting a novel mechanism was conferring resistance. Genomic analysis identified two significant genetic determinants with explanatory power for the high level of QD resistance in the ST80 QD-resistant clone: an additional 56aa leader sequence at the N-terminus of the lsaE gene and a transposon containing seven genes encoding proteins with possible drug or drug-target modification activities. However, HTS was unable to conclusively determine the QD resistance mechanism and did not reveal any genetic basis for QD resistance in the ST192 clone. This study highlights the usefulness of HTS in deciphering the degree of relatedness in two concurrent GRE outbreaks. Although HTS was able to reveal some genetic candidates for uncharacterised QD resistance, this study demonstrates the limitations of HTS as a tool for identifying putative determinants of resistance to QD.

Protective Effect of Bauhinia purpurea on Gentamicin-induced Nephrotoxicity in Rats

Science.gov (United States)

Lakshmi, B. V. S.; Neelima, N.; Kasthuri, N.; Umarani, V.; Sudhakar, M.

2009-01-01

The present study was undertaken to evaluate the ethanol extract of leaves of Bauhinia purpurea and unripe pods of Bauhinia purpurea for its protective effects on gentamicin-induced nephrotoxicity in rats. Nephrotoxicity was induced in Wistar rats by intraperitoneal administration of gentamicin 100 mg/kg/d for eight days. Effect of concurrent administration of ethanol extract of leaves of Bauhinia purpurea and unripe pods of Bauhinia purpurea at a dose of 300 mg/kg/d given by oral route was determined using serum creatinine, serum uric acid, blood urea nitrogen and serum urea as indicators of kidney damage. The study groups contained six rats in each group. It was observed that the ethanol extract of leaves of Bauhinia purpurea and unripe pods of Bauhinia purpurea significantly protect rat kidneys from gentamicin-induced histopathological changes. Gentamicin-induced glomerular congestion, blood vessel congestion, epithelial desquamation, accumulation of inflammatory cells and necrosis of the kidney cells were found to be reduced in the groups receiving the leaf and unripe pods extract of Bauhinia purpurea along with gentamicin. The extracts also normalized the gentamicin-induced increase in serum creatinine, serum uric acid and blood urea nitrogen levels. This is also evidenced by the histopathological studies. PMID:20502576

THE RESISTANCE TO ANTIBIOTICS IN STRAINS OF E. COLI AND ENTEROCOCCUS SP. ISOLATED FROM RECTAL SWABS OF LAMBS AND CALVES

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IVANA NOVÁKOVÁ

2009-10-01

Full Text Available he aim of this study was to determine the prevalence and antibiotic resistance of enterococcii and E. coli strains isolated from dairy calves and lambs. Susceptibilities of isolated enterococci were tested using the disk diffusion method. The interpretation of inhibition zones around the disks was according to CLSI 2004 Performance standards for antimicrobial susceptibility testing. In our study, all isolates (E. coli and enterococci were multiresistant (100% to tetracycline, streptomycin and compound sulphonamides. Lower levels of resistance to enrofloxacin were noted. Antimicrobial resistance profiles of Enterococcus sp. isolated from lambs indicated that the highest percentage of susceptibility was exhibited to tetracycline (100% and streptomycin (100% and compound sulphonamides (100%. The intermediate resistance was exhibited against compound enrofloxacin (80%. The high frequencies of resistant isolates of Enterococcus sp. from calves were documented in tetracycline (100%, streptomycin (100% and compound sulphonamides (100% and enrofloxacin (50%. The high percentage (compound sulphonamides-100%, tetracycline-100% and streptomycin- 100% of multiresistant E. coli (isolates from dairy calves was noticed. There were no significant correlations between groups.

Resistance of Pseudomonas aeruginosa PAO to nalidixic acid and low levels of beta-lactam antibiotics: mapping of chromosomal genes.

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Rella, M; Haas, D

1982-01-01

Resistance to high concentrations of nalidixic acid in Pseudomonas aeruginosa PAO was due to mutations in one locus designated nalA, which was mapped by transduction between hex-9001 and leu-10. The nalA mutants were cross-resistant to pipemidic acid, a nalidixic acid analog, at relatively low concentrations. Replicative DNA synthesis was resistant to both drugs in permeabilized cells of nalA mutants. A locus coding for low-level resistance to nalidixic acid, nalB, was cotransducible with pyrB, proC, and met-28. The nalB mutants were also resistant to low levels of pipemidic acid, novobiocin, and beta-lactam antibiotics (e.g., carbenicillin, azlocillin, and cefsulodin), but not to other drugs, such as gentamicin, rifampin, kanamycin, or tetracycline. In nalB mutants, DNA replication showed wild-type sensitivity to nalidixic acid, whereas carbenicillin-induced filamentation required higher drug levels than in the wild-type strain. Thus, nalB mutations appear to decrease cell permeability to some antibiotics. The sensitivity of replicative DNA synthesis to nalidixic acid and novobiocin was very similar in P. aeruginosa and Escherichia coli; by contrast, the concentrations of these drugs needed to inhibit growth of P. aeruginosa were higher than those reported for E. coli by one or two orders of magnitude. PMID:6821455

Weekly screening supports terminating nosocomial transmissions of vancomycin-resistant enterococci on an oncologic ward – a retrospective analysis

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Stefanie Kampmeier

2017-05-01

Full Text Available Abstract Background To investigate the impact of weekly screening within the bundle of infection control measures to terminate vancomycin-resistant enterococci (VRE transmissions on an oncologic ward. Methods A cluster of 12 VRE colonisation and five infections was detected on an oncologic ward between January and April 2015. Subsequently, the VRE point prevalence was detected and, as part of a the bundle of infection control strategies to terminate the VRE cluster, we isolated affected patients, performed hand hygiene training among staff on ward, increased observations by infection control specialists, intensified surface disinfection, used personal protective equipment and initiated an admission screening in May 2015. After a further nosocomial VRE infection in August 2015, a weekly screening strategy of all oncology patients on the respective ward was established while admission screening was continued. Whole genome sequencing (WGS-based typing was applied to determine the clonal relationship of isolated strains. Results Initially, 12 of 29 patients were VRE colonised; of these 10 were hospital-acquired. During May to August, on average 7 of 40 patients were detected to be VRE colonised per week during the admission screening, showing no significant decline compared to the initial situation. WGS-based typing revealed five different clusters of which three were due to vanB- and two vanA-positive enterococci. After an additional weekly screening was established, the number of colonised patients significantly declined to 1/53 and no further nosocomial cases were detected. Conclusions Weekly screening helped to differentiate between nosocomial and community-acquired VRE cases resulting in earlier infection control strategies on epidemic situations for a successful termination of nosocomial VRE transmissions.

Antimicrobial resistance in community and nosocomial Escherichia coli urinary tract isolates, London 2005 – 2006

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Wareham David W

2008-06-01

Full Text Available Abstract Background Escherichia coli is the commonest cause of community and nosocomial urinary tract infection (UTI. Antibiotic treatment is usually empirical relying on susceptibility data from local surveillance studies. We therefore set out to determine levels of resistance to 8 commonly used antimicrobial agents amongst all urinary isolates obtained over a 12 month period. Methods Antimicrobial susceptibility to ampicillin, amoxicillin/clavulanate, cefalexin, ciprofloxacin, gentamicin, nitrofurantoin, trimethoprim and cefpodoxime was determined for 11,865 E. coli urinary isolates obtained from community and hospitalised patients in East London. Results Nitrofurantoin was the most active agent (94% susceptible, followed by gentamicin and cefpodoxime. High rates of resistance to ampicillin (55% and trimethoprim (40%, often in combination were observed in both sets of isolates. Although isolates exhibiting resistance to multiple drug classes were rare, resistance to cefpodoxime, indicative of Extended spectrum β-lactamase production, was observed in 5.7% of community and 21.6% of nosocomial isolates. Conclusion With the exception of nitrofurantoin, resistance to agents commonly used as empirical oral treatments for UTI was extremely high. Levels of resistance to trimethoprim and ampicillin render them unsuitable for empirical use. Continued surveillance and investigation of other oral agents for treatment of UTI in the community is required.

Risk factors associated with fluoroquinolone-resistant enterococcal urinary tract infections in a tertiary care university hospital in north India.

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Banerjee, Tuhina; Anupurba, Shampa

2016-10-01

Fluoroquinolone resistance in both Gram-positive and Gram-negative bacteria has increased with the widespread use of fluoroquinolones. Fluoroquinolone resistance in Gram-negative bacilli has been widely studied, though staphylococci and enterococci are also notably resistant. Enterococci being the second most common cause of healthcare-associated urinary tract infections (UTIs) fluoroquinolones are often the drug of choice. This study was undertaken to assess the risk factors associated with fluoroquinolone-resistant enterococcal UTI in a tertiary level health facility in north India. A total of 365 patients with UTI caused by enterococci were studied over a period of two years. Patients with ciprofloxacin-resistant and susceptible UTI were considered as cases and controls, respectively. Resistance profile of the isolates against common antibiotics was studied by minimum inhibitory concentration (MIC) determination. Mechanisms for fluoroquinolone resistance was studied by efflux pump inhibitor activity and multiplex PCR targeting the qnr genes. A total of 204 (55.89%) cases and 161 (44.1%) controls were identified. The fluoroquinolone-resistant isolates were significantly resistant to ampicillin, high strength aminoglycosides and vancomycin. The majority (78%) of the resistant isolates showed efflux pump activity. Treatment in indoor locations, presence of urinary catheters and pregnancy along with recent exposure to antibiotics especially fluoroquinolones, third generation cephalosporins and piperacillin-tazobactam were identified as independent risk factors. Our results showed that fluoroquinolone resistance in enterococcal UTI was largely associated with indoor usage of antibiotics and use of indwelling devices. Knowledge of risk factors is important to curb this emergence of resistance.

Gentamicin concentration gradients in scala tympani perilymph following systemic applications.

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Hahn, Hartmut; Salt, Alec N; Schumacher, Ulrike; Plontke, Stefan K

2013-01-01

It has been shown in prior studies that round window membrane (RWM) application of gentamicin produced a robust basal-apical concentration gradient in the perilymph of scala tympani (ST) with peak concentrations in the basal turn of ST. These gradients potentially contribute to the clinical efficacy and safety of intratympanic gentamicin applications for the treatment of Ménière's disease. The present study aimed to establish the distribution of gentamicin along ST perilymph after systemic applications. Gentamicin sulfate was applied intravenously in the amounts of 100, 300 and 600 mg/kg body weight (BW) over a period of 3 h or as a 300 mg/kg BW subcutaneous bolus injection. At 3 and 5 h after the start of the application perilymph of ST was aspirated from the cochlea apex of the right and left cochlea, respectively, and 10 sequential 1-µl perilymph samples from the apex of each cochlea were quantitatively analyzed using a fluorescence polarization immunoassay. In contrast to local RWM delivery, systemic application of gentamicin resulted in the highest perilymph levels in the apex of the cochlea with decreasing concentrations towards the basal regions of ST. The absolute gentamicin concentrations increased with the amount of drug applied and time before sampling. While it is likely that the basal-apical gradient measured after local drug applications to the round window niche is the result of the direct uptake of drugs into the perilymph of the ST, distribution by diffusion and a very low perilymph flow towards the cochlear apex, computer simulations suggested that the apical-basal gradient observed with these systemic applications can be explained by higher entry rates of gentamicin in the apex compared to the basal turns of the cochlea. It is also possible that gentamicin enters perilymph indirectly from the blood via the endolymph. In this case the faster kinetics in apical turns could be due to the smaller cross-sectional area of ST relative to endolymph in

Determination of the effects of levofloxacin on gentamicin induced nephrotoxicity in rabbits: a comparative study

International Nuclear Information System (INIS)

Naeem, U.; Jamal, S.; Waheed, A.

2015-01-01

Objective: To determine the effects of levofloxacin on gentamicin induced nephrotoxicity in rabbits. Study Design: Comparative experimental study. Place and Duration of Study: The animal house of Army Medical College, Rawalpindi, and the pathology department of Army Medical College, Rawalpindi, from July 2009 to January 2010. Material and Methods: The effects of levofloxacin on gentamicin-induced nephrotoxicity were evaluated in rabbits. Twenty four rabbits were used in this study which were randomly divided into four groups (n= 6 in each group). Six animals were injected for 15 days with saline (NaCl; 0.9%), six with gentamicin alone at doses of 20 mg/kg of body weight/12 h (intramuscularly), six with combination of gentamicin (20 mg/kg/12 h) with low therapeutic doses of levofloxacin (30 mg/kg/24 h) and the last six were treated with gentamicin and high therapeutic doses of levofloxacin (50 mg/kg/24 h). Levofloxacin was given by intraperitoneal route. Results: Gentamicin induced nephrotoxicity was evaluated by histopathological and serum analysis. The extent of nephrotoxicity was significantly increased when gentamicin was given in combination with levofloxacin both in low and high doses. Conclusion: Levofloxacin enhances gentamicin induced nephrotoxicity and extent of this nephrotoxicity increased with increasing dose of levofloxacin. (author)

The frequency of resistance to antibiotics of most frequently isolated bacteria from blood cultures during the period 1997-2002

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Mirović Veljko

2004-01-01

Full Text Available The aim of this study was to determine the frequency of resistance to antibiotics of the most frequently isolated bacteria from blood cultures of hospitalized patients during the period 1997-2002. The resistance to antibiotics was determined by disk diffusion method according to National Committee for Clinical Laboratory Standards procedures. The majority of staphylococci isolates were resistant to methicillin, and the proportion of methicillin-resistant Staphylococcus aureus was stable (76.8-81.6%, during the follow-up period. None of the staphylococci isolates were resistant to vancomycin, but there was a very high incidence of high-level resistance of enterococci to aminoglycosides (47.2-72.2%. In 1998, only one strain among enterococci was resistant to vancomycin (Enterococcus faecium, VanA fenotype. Enterococcus spp isolates expressed variable frequency of resistance to ampicillin (15-40.1% during the follow-up period. Among Enterobacteriaceae there were no isolates resistant to imipenem, but dramatic increase of the resistance to ceftriaxone was found from 35.9% in 1997 to 95.9% in 2002 (p<0.001. Extended spectrum beta-lactamases production was found in all the species of enterobacteria isolates. Resistance to imipenem was observed in Acinetobacter spp isolates in 2002 for the first time. Pseudomonas spp isolates expressed high and very variable resistance to all antibiotics tested during the follow-up period.

Aislamiento de especies de enterococos causantes de infecciones y su sensibilidad a los antimicrobianos Isolation of enterococci species causative of infections and sensitivity to antimicrobial drugs

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C. Toledo

2004-03-01

Full Text Available Entre abril de 1999 y julio de 2000 se obtuvieron 144 aislamientos sucesivos de enterococos (uno por paciente a partir de cultivos de una variedad de sitios anatómicos. La distribución de las diferentes especies fue: 119 (82,6% Enterococcus faecalis, 11 (7,6% E. faecium y 14 (9,7% otras especies (5 E. raffinosus, 4 E. avium, 3 E. casseliflavus, 1 E. pseudoavium y 1 E. dispar, las cuales estuvieron asociadas con infecciones clínicas. Los sitios más comunes de aislamiento fueron: tracto urinario 54,9%, cavidad abdominal 12,5%, heridas quirúrgicas 12,5%, abscesos 6,9% y pie diabético 6,2%. Se detectó alto nivel de resistencia a gentamicina, estreptomicina o ambos en 48,6% de los aislamientos. Los aislamientos de E. faecium y E. raffinosus fueron significativamente más resistentes a ampicilina e imipenem que E. faecalis. Ninguna de las cepas exhibió actividad de b-lactamasa. Una cepa de E. faecium (0,7% fue resistente a vancomicina y teicoplanina (fenotipo Van A y dos cepas de E. casseliflavus (1,4% mostraron bajo nivel de resistencia a vancomicina (fenotipo Van C. Debido a estos diversos mecanismos de resistencia antimicrobiana, el tratamiento exitoso y el control de las infecciones enterocócicas con agentes antimicrobianos corrientes se hace cada vez más dificultoso.Beetween April 1, 1999 and June 30, 2000, 144 isolates of enterococci (one per patient from cultures of several anatomic sites were collected . One hundred and nineteen (82.6% E. faecalis, 11 (7.6% E. faecium and 14 (9.7% of other species (5 E. raffinosus, 4 E. avium, 3 E. casseliflavus, 1 E. pseudoavium, and 1 E. dispar were associated with clinical infections. The most common sites of isolation were: the urinary tract 54.9%, abdominal cavity 12.5%, surgical wounds 12.5%, abscesses 6.9% and diabetic foot 6.2%. High-level resistance to gentamicin or streptomycin or both was detected in 48.6% of the isolates. E. faecium and E. raffinosus were significantly more resistant than

Resistance mechanisms of linezolid-nonsusceptible enterococci in Korea: low rate of 23S rRNA mutations in Enterococcus faecium.

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Lee, Sae-Mi; Huh, Hee Jae; Song, Dong Joon; Shim, Hyang Jin; Park, Kyung Sun; Kang, Cheol-In; Ki, Chang-Seok; Lee, Nam Yong

2017-12-01

To investigate linezolid-resistance mechanisms in linezolid-nonsusceptible enterococci (LNSE) isolated from a tertiary hospital in Korea. Enterococcal isolates exhibiting linezolid MICs ≥4 mg l -1 that were isolated between December 2011 and May 2016 were investigated by PCR and sequencing for mutations in 23S rRNA or ribosomal proteins (L3, L4 and L22) and for the presence of cfr, cfr(B) and optrA genes.Results/Key findings. Among 135 LNSE (87 Enterococcus faecium and 48 Enterococcus faecalis isolates), 39.1 % (34/87) of E. faecium and 18.8 % (9/48) of E. faecalis isolates were linezolid-resistant. The optrA carriage was the dominant mechanism in E. faecalis: 13 isolates, including 10 E. faecalis [70 % (7/10) linezolid-resistant and 30 % (3/10) linezolid-intermediate] and three E. faecium [33.3 % (1/3) linezolid-resistant and 66.7 % (2/3) linezolid-intermediate], contained the optrA gene. G2576T mutations in the 23S rRNA gene were detected only in E. faecium [14 isolates; 71.4 % (10/14) linezolid-resistant and 28.6 % (4/14) linezolid-intermediate]. One linezolid-intermediate E. faecium harboured a L22 protein alteration (Ser77Thr). No isolates contained cfr or cfr(B) genes and any L3 or L4 protein alterations. No genetic mechanism of resistance was identified for 67.6 % (23/34) of linezolid-resistant E. faecium. A low rate of 23S rRNA mutations and the absence of known linezolid-resistance mechanisms in the majority of E. faecium isolates suggest regional differences in the mechanisms of linezolid resistance and the possibility of additional mechanisms.

Enterococci in the Environment

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Enterococci are common, commensal members of gut communities in mammals and birds, yet they are also opportunistic pathogens that cause millions of human and animal infections annually. Because they are shed in human and animal feces, are readily culturable, and predict human hea...

Antibiotic resistance

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Marianne Frieri

2017-07-01

Full Text Available Summary: Antimicrobial resistance in bacterial pathogens is a challenge that is associated with high morbidity and mortality. Multidrug resistance patterns in Gram-positive and -negative bacteria are difficult to treat and may even be untreatable with conventional antibiotics. There is currently a shortage of effective therapies, lack of successful prevention measures, and only a few new antibiotics, which require development of novel treatment options and alternative antimicrobial therapies. Biofilms are involved in multidrug resistance and can present challenges for infection control. Virulence, Staphylococcus aureus, Clostridium difficile infection, vancomycin-resistant enterococci, and control in the Emergency Department are also discussed. Keywords: Antibiotic resistance, Biofilms, Infections, Public health, Emergency Department

Controlling for endogeneity in attributable costs of vancomycin-resistant enterococci from a Canadian hospital.

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Lloyd-Smith, Patrick

2017-12-01

Decisions regarding the optimal provision of infection prevention and control resources depend on accurate estimates of the attributable costs of health care-associated infections. This is challenging given the skewed nature of health care cost data and the endogeneity of health care-associated infections. The objective of this study is to determine the hospital costs attributable to vancomycin-resistant enterococci (VRE) while accounting for endogeneity. This study builds on an attributable cost model conducted by a retrospective cohort study including 1,292 patients admitted to an urban hospital in Vancouver, Canada. Attributable hospital costs were estimated with multivariate generalized linear models (GLMs). To account for endogeneity, a control function approach was used. The analysis sample included 217 patients with health care-associated VRE. In the standard GLM, the costs attributable to VRE are $17,949 (SEM, $2,993). However, accounting for endogeneity, the attributable costs were estimated to range from $14,706 (SEM, $7,612) to $42,101 (SEM, $15,533). Across all model specifications, attributable costs are 76% higher on average when controlling for endogeneity. VRE was independently associated with increased hospital costs, and controlling for endogeneity lead to higher attributable cost estimates. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Molecular Analysis of Vancomycin-Resistant Enterococci Isolated from Regional Hospitals in Trinidad and Tobago

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Patrick E. Akpaka

2016-01-01

Full Text Available Geographic spread of vancomycin-resistant enterococci (VRE clones in cities, countries, or even continents has been identified by molecular techniques. This study aimed at characterizing virulent genes and determining genetic relatedness of 45 VRE isolates from Trinidad and Tobago using molecular tools, including polymerase chain reaction, pulsed-field gel electrophoresis (PFGE, and Random Amplification Polymorphic DNA (RAPD. The majority (84% of the isolates were Enterococcus faecium possessing vanA gene while the rest (16% were Enterococcus faecalis possessing vanB. The esp gene was found in all 45 VRE isolates while hyl genes were found only in E. faecium species. The E. faecium species expressed five distinct PFGE patterns. The predominant clones with similar or common patterns belonged to clones one and three, and each had 11 (29% of the VRE isolates. Plasmid content was identified in representative isolates from each clonal group. By contrast, the E. faecalis species had one PFGE pattern suggesting the presence of an occult and limited clonal spread. The emergence of VRE in the country seems to be related to intra/interhospital dissemination of an epidemic clone carrying the vanA element. Therefore, infection control measures will be warranted to prevent any potential outbreak and spread of VRE in the country.

A prospective study of gentamicin ototoxicity

DEFF Research Database (Denmark)

Winkel, O; Hansen, M M; Kaaber-Bühler, Søren

2010-01-01

of gentamicin did not rule out the possiblity of ototoxicity. These results urge the continuing of prospective studies and indicate that gentamicin should be used only as a link in the primary treatment of severe infection or in cases in which other, less toxic agents have failed....

A prospective study of gentamicin ototoxicity

DEFF Research Database (Denmark)

Winkel, O; Hansen, M M; Kaaber-Bühler, Søren

1978-01-01

of gentamicin did not rule out the possiblity of ototoxicity. These results urge the continuing of prospective studies and indicate that gentamicin should be used only as a link in the primary treatment of severe infection or in cases in which other, less toxic agents have failed....

Genetic relatedness of faecal coliforms and enterococci bacteria isolated from water and sediments of the Apies River, Gauteng, South Africa.

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Ekwanzala, Mutshiene Deogratias; Abia, Akebe Luther King; Ubomba-Jaswa, Eunice; Keshri, Jitendra; Momba, Ndombo Benteke Maggy

2017-12-01

To date, the microbiological quality of river sediments and its impact on water resources are not included in the water quality monitoring assessment. Therefore, the aim of this study was to establish genetic relatedness between faecal coliforms and enterococci isolated from the river water and riverbed sediments of Apies River to better understand the genetic similarity of microorganisms between the sediment and water phases. Indicator bacteria were subjected to a molecular study, which consisted of PCR amplification and sequence analysis of the 16S rRNA and 23S rRNA gene using specific primers for faecal coliforms and enterococci, respectively. Results revealed that the Apies River had high faecal pollution levels with enterococci showing low to moderate correlation coefficient (r 2 values ranged from 0.2605 to 0.7499) compared to the faecal coliforms which showed zero to low correlation (r 2 values ranged from 0.0027 to 0.1407) indicating that enterococci may be better indicator than faecal coliforms for detecting faecal contamination in riverbed sediments. The phylogenetic tree of faecal coliforms revealed a 98% homology among their nucleotide sequences confirming the close genetic relatedness between river water and riverbed sediment isolates. The phylogenetic tree of the enterococci showed that Enterococcus faecalis and Enterococcus faecium are the predominant species found in both river water and riverbed sediments with bootstrap values of ≥99%. A high degree of genetic relatedness between sediment and water isolates indicated a possible common ancestry and transmission pathway. We recommend the microbial monitoring of riverbed sediments as it harbours more diverse microbial community and once resuspended may cause health and environmental problems.

Title: High-level cefotaxime-resistant Proteus mirabilis strain isolated ...

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High-level cefotaxime-resistant Proteus mirabilis strain isolated from a Tunisian .... UV- visible) at 37°C. Specific activity is calculated on depending of. Ross and ..... Performance standards for antimicrobial susceptibility testing;. Seventeenth ...

Effect of Taurine on the antimicrobial efficiency of Gentamicin

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Islambulchilar Mina

2011-12-01

Full Text Available Context: Gentamicin is mainly used in severe infections caused by gram-negatives. However toxicity including nephrotoxicity and ototoxicity is one of the most important complications of its treatment. The production of free radicals seems to be involved in gentamicin toxicity mechanism. Taurine, a major intracellular free β-amino acid, is known to be an endogenous antioxidant. So potentially the co-therapy of taurine and gentamicin would reduce the adverse effects of the antibiotic. Objectives: In this study, we wished to know the effect of taurine on the antibiotic capacity of gentamicin. methods: strains of P. aeruginosa, E. coli, S. aureus and S. epidermidis were used as test organisms. Minimum inhibitory concentrations of gentamicin in the presence and absence of taurine at quantities from 40 to 2 mg/L were determined using macro-dilution method. Results: MICs were determined in the various concentrations of taurine for bacterial indicators. The MIC values of gentamicin for P. aeruginosa, S. aureus and E. coli remained unchanged in the values of 2.5, 5 and 20 μg/ml respectively in the absence and presences of different concentrations of taurine. The bactericidal activity of gentamicin against S. epidermidis was increased by addition of taurine in the concentrations higher than 6 mg/L. Conclusion: According to our study the antibacterial activity of gentamicin against the indicator microorganisms were not interfere with taurine at selected concentrations. Further in vivo studies are needed to establish if a combination of gentamicin and taurine would have the same effect.

Sildenafil Ameliorates Gentamicin-Induced Nephrotoxicity in Rats: Role of iNOS and eNOS

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Mohamed A. Morsy

2014-01-01

Full Text Available Gentamicin, an aminoglycoside antibiotic, is used for the treatment of serious Gram-negative infections. However, its usefulness is limited by its nephrotoxicity. Sildenafil, a selective phosphodiesterase-5 inhibitor, was reported to prevent or decrease tissue injury. The aim of this study is to evaluate the potential protective effects of sildenafil on gentamicin-induced nephrotoxicity in rats. Male Wistar rats were injected with gentamicin (100 mg/kg/day, i.p. for 6 days with and without sildenafil. Sildenafil administration resulted in nephroprotective effect in gentamicin-intoxicated rats as it significantly decreased serum creatinine and urea, urinary albumin, and renal malondialdehyde and nitrite/nitrate levels, with a concomitant increase in renal catalase and superoxide dismutase activities compared to gentamicin-treated rats. Moreover, immunohistochemical examination revealed that sildenafil treatment markedly reduced inducible nitric oxide synthase (iNOS expression, while expression of endothelial nitric oxide synthase (eNOS was markedly enhanced. The protective effects of sildenafil were verified histopathologically. In conclusion, sildenafil protects rats against gentamicin-induced nephrotoxicity possibly, in part, through its antioxidant activity, inhibition of iNOS expression, and induction of eNOS production.

Integrated transcriptomic and proteomic evaluation of gentamicin nephrotoxicity in rats

International Nuclear Information System (INIS)

Com, Emmanuelle; Boitier, Eric; Marchandeau, Jean-Pierre; Brandenburg, Arnd; Schroeder, Susanne; Hoffmann, Dana; Mally, Angela; Gautier, Jean-Charles

2012-01-01

Gentamicin is an aminoglycoside antibiotic, which induces renal tubular necrosis in rats. In the context of the European InnoMed PredTox project, transcriptomic and proteomic studies were performed to provide new insights into the molecular mechanisms of gentamicin-induced nephrotoxicity. Male Wistar rats were treated with 25 and 75 mg/kg/day subcutaneously for 1, 3 and 14 days. Histopathology observations showed mild tubular degeneration/necrosis and regeneration and moderate mononuclear cell infiltrate after long-term treatment. Transcriptomic data indicated a strong treatment-related gene expression modulation in kidney and blood cells at the high dose after 14 days of treatment, with the regulation of 463 and 3241 genes, respectively. Of note, the induction of NF-kappa B pathway via the p38 MAPK cascade in the kidney, together with the activation of T-cell receptor signaling in blood cells were suggestive of inflammatory processes in relation with the recruitment of mononuclear cells in the kidney. Proteomic results showed a regulation of 163 proteins in kidney at the high dose after 14 days of treatment. These protein modulations were suggestive of a mitochondrial dysfunction with impairment of cellular energy production, induction of oxidative stress, an effect on protein biosynthesis and on cellular assembly and organization. Proteomic results also provided clues for potential nephrotoxicity biomarkers such as AGAT and PRBP4 which were strongly modulated in the kidney. Transcriptomic and proteomic data turned out to be complementary and their integration gave a more comprehensive insight into the putative mode of nephrotoxicity of gentamicin which was in accordance with histopathological findings. -- Highlights: ► Gentamicin induces renal tubular necrosis in rats. ► The mechanisms of gentamicin nephrotoxicity remain still elusive. ► Transcriptomic and proteomic analyses were performed to study this toxicity in rats. ► Transcriptomic and proteomic

Intestinal transport of gentamicin with a novel, glycosteroid drug transport agent

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Axelrod, H. R.; Kim, J. S.; Longley, C. B.; Lipka, E.; Amidon, G. L.; Kakarla, R.; Hui, Y. W.; Weber, S. J.; Choe, S.; Sofia, M. J.

1998-01-01

PURPOSE: The objective was to investigate the ability of a glycosteroid (TC002) to increase the oral bioavailability of gentamicin. METHODS: Admixtures of gentamicin and TC002 were administered to the rat ileum by injection and to dogs by ileal or jejunal externalized ports, or PO. Bioavailability of gentamicin was determined by HPLC. 3H-TC002 was injected via externalized cannulas into rat ileum or jejunum, or PO and its distribution and elimination was determined. The metabolism of TC002 in rats was evaluated by solid phase extraction and HPLC analysis of plasma, urine and feces following oral or intestinal administration. RESULTS: The bioavailability of gentamicin was substantially increased in the presence of TC002 in both rats and dogs. The level of absorption was dependent on the concentration of TC002 and site of administration. Greatest absorption occurred following ileal orjejunal administration. TC002 was significantly more efficacious than sodium taurocholate, but similar in cytotoxicity. TC002 remained primarily in the GI tract following oral or intestinal administration and cleared rapidly from the body. It was only partly metabolized in the GI tract, but was rapidly and completely converted to its metabolite in plasma and urine. CONCLUSIONS: TC002 shows promise as a new drug transport agent for promoting intestinal absorption of polar molecules such as gentamicin.

The testing of sanitizers efficacy to enterococci adhered on glass surfaces

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Margita Čanigová

2015-08-01

Full Text Available The aim of this work was to test the ability of 6 strains of enterococci to adhere on glass surfaces in environment with different content of milk residues and then to evaluate efficacy of 2 commercial sanitizers (alkaline and acidic used in milk production. Tested enterococci were isolated from milk, dairy products and from rinse water after sanitation milking machine. Suspension of enterococci (8 log CFU.ml-1 was prepared in phosphate buffered saline (PBS, PBS with content 0.1% and 1% of skimmed reconstituted milk. Glass plates were immersed into bacterial suspension for 1 h at 37 °C. The number of enterococci adhered on glass surface in PBS achieved an average value 3.47 log CFU.mm-2, in PBS with 0.1% of milk 2.90 CFU.mm-2, in PBS with 1% of milk 2.63 CFU.mm-2. Differences between the tested files were not statistically significant (p >0.05. In the second part of work the glass plates with adhered enterococci were exposed to the effect of alkaline sanitizer (on basis of NaOH and NaClO, respectively acidic sanitizer (on basis of H3PO4. Sanitation solutions were prepared and tested according to manufacturer recommendations (concentration 0.25%, contact time 20 min, temperature   20 °C. Alkaline sanitation solution was 100% effective against all tested enterococci regardless to content of milk residues in environment. Acidic sanitation solution was 100% effective only against E. faecalisD (isolated from rinse water after sanitation. Average value of reduction of enterococci with acidic sanitation solution, which were on glass plates in environment PBS was 2.84 CFU.mm-2, in PBS with 0.1% of milk was 2.45 CFU.mm-2 and in PBS with 1% of milk was 2.16 CFU.mm-2. It can be concluded, that increase of milk residues in environment decrease the adhesion of enterococci on glass surface, but also effectiveness of acidic sanitation solution.

Incidence of high-level evernimicin resistance in Enterococcus faecium among food animals and humans

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Aarestrup, Frank Møller; McNicholas, P. M.

2002-01-01

Six high-level evernimicin-resistant Enterococcus faecium isolates were identified among 304 avilarnycin-resistant E. faecium isolates from animals and 404 stool samples from humans with diarrhea. All four animal isolates, and one of the human isolates, were able to transfer resistance...... to a susceptible E. faecium strain. The resulting transconjugants all tested positive for the presence of emtA, a gene encoding a methyltransferase previously linked with high-level evernimicin resistance. The four transconjugants derived from animal isolates all carried the same plasmid, while a differently sized...... plasmid was found in the isolate from humans. This study demonstrated a low incidence of high-level evernimicin resistance mediated by the emtA gene in different E. faecium isolates of animal and human origin....

Successful prevention of the transmission of vancomycin-resistant enterococci in a Brazilian public teaching hospital

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Flávia Alves Ferreira Rossini

2012-04-01

Full Text Available INTRODUCTION: Vancomycin-resistant enterococci (VRE can colonize or cause infections in high-risk patients and contaminate the environment. Our objective was to describe theepidemiological investigation of an outbreak of VRE, the interventions made, and their impact on its control. METHODS: We conducted a retrospective, descriptive, non-comparative study by reviewing the charts of patients with a VRE-positive culture in the University Hospital of Campinas State University, comprising 380 beds, 40 of which were in intensive care units (ICUs, who were admitted from February 2008-January 2009. Interventions were divided into educational activity, reviewing the workflow processes, engineering measures, and administrative procedures. RESULTS: There were 150 patients, 139 (92.7% colonized and 11 (7.3% infected. Seventy-three percent were cared for in non-ICUs (p = 0.028. Infection was more frequent in patients with a central-line (p = 0.043, mechanical ventilation (p = 0.013, urinary catheter (p = 0.049, or surgical drain (p = 0.049. Vancomycin, metronidazole, ciprofloxacin, and third-generation cephalosporin were previously used by 47 (31.3%, 31 (20.7%, 24 (16%, and 24 (16% patients, respectively. Death was more frequent in infected (73% than in colonized (17% patients (p < 0.001. After the interventions, the attack rate fell from 1.49 to 0.33 (p < 0.001. CONCLUSIONS: Classical risk factors for VRE colonization or infection, e.g., being cared for in an ICU and previous use of vancomycin, were not found in this study. The conjunction of an educational program, strict adhesion to contact precautions, and reinforcement of environmental cleaning were able to prevent the dissemination of VRE.

Severity of gentamicin's nephrotoxic effect on patients with infective endocarditis: a prospective observational cohort study of 373 patients

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Buchholtz, Kristine; Larsen, Carsten T; Hassager, Christian

2009-01-01

BACKGROUND: Gentamicin is often used to treat infective endocarditis (IE). Gentamicin is highly effective, but its applicability is reduced by its nephrotoxic effect. The aim of this study was to quantify the nephrotoxic effect of gentamicin and the association between the nephrotoxic effect...

Controlling antibiotic resistance in the ICU

NARCIS (Netherlands)

Derde, L.P.G.

2013-01-01

Patients admitted to intensive care units (ICUs) are frequently colonized with (antibiotic-resistant) bacteria, which may lead to healthcare associated infections. Antimicrobial-resistant bacteria (AMRB), such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci

Use of a gentamicin-impregnated collagen sheet (Collatamp(®)) in the management of major soft tissue complications in pediatric cochlear implants.

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Benito-González, Fernando; Benito, Jose; Sánchez, Luis Alberto Guardado; Estevez Alonso, Santiago; Muñoz Herrera, Angel; Batuecas-Caletrio, Angel

2014-09-01

The objective was to report the effectiveness of salvage treatment in soft tissue infection around cochlear implants with an absorbable gentamicin collagen sheet and a periosteum and skin rotation flaps. Three patients with cochlear implant and persistent surrounding soft tissue infection are included. All of them underwent antibiotic treatment prior to surgery without any response. In this study preoperative and postoperative audiograms were practiced. Surgical excision of infectious skin and a periosteum and skin rotation flaps were performed. The cochlear implant was refixed in the temporal bone and a gentamicin-impregnated collagen sheet was located covering the cochlear implant. headings In all patients with soft tissue infection around the cochlear implant, infection was completely resolved. It was not necessary to remove the device in any case. The use of an absorbable gentamicin-impregnated collagen sheet is not described for the management of soft tissue complications in pediatric cochlear implant patients. The local application of high concentrations of antibiotic administered by this sheet may be effective against resistant bacteria and, in conjunction with surgery, may resolve this type of complications.

Proactive infection control measures to prevent nosocomial transmission of vancomycin-resistant enterococci in Hong Kong.

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Cheng, Vincent Chi-Chung; Tai, Josepha Wai-Ming; Chen, Jonathan Hon-Kwan; So, Simon Yung-Chun; Ng, Wing-Chun; Hung, Ivan Fan-Ngan; Leung, Sally Sau-Man; Wong, Sally Cheuk-Ying; Chan, Tuen-Ching; Chan, Felix Hon-Wai; Ho, Pak-Leung; Yuen, Kwok-Yung

2014-10-01

The study describes a proactive infection control approach to prevent nosocomial transmission of vancomycin-resistant enterococci (VRE) and tests if this approach is effective for controlling multiple-drug resistant organisms in a nonendemic setting. In response to the increasing prevalence of VRE in Hong Kong since 2011, we adopted a multifaceted assertive approach in our health care network. This included active surveillance culture, extensive contact tracing, directly observed hand hygiene in conscious patients before they received meals and medications, stringent hand hygiene and environmental cleanliness, and an immediate feedback antimicrobial stewardship program. We report the occurrence of VRE outbreaks in our hospital after institution of these measures and compared with the concurrent occurrence in other public hospitals in Hong Kong. Between July 1, 2011 and November 13, 2013, VRE was identified in 0.32% (50/15,851) of admission episodes by active surveillance culture. The risk of VRE carriage was three times higher in patients with a history of hospitalization outside our hospital networks in the past 3 months (0.56% vs. 0.17%; p = 0.001) compared with those who were not. Extensive contact tracing involving 3277 patient episodes was performed in the investigation for the 25 VRE index patients upon whom implementation of contact precautions was delayed (more than 48 hours of hospitalization). One episode of VRE outbreak was identified in our hospital network, compared with the 77 VRE outbreaks reported in the other hospital networks (controls) without these proactive infection control measures. Our multifaceted assertive proactive infection control approach can minimize the nosocomial transmission and outbreak of VRE in a nonendemic area. Copyright © 2014. Published by Elsevier B.V.

Attachment of Escherichia coli and enterococci to particles in runoff.

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Soupir, Michelle L; Mostaghimi, Saied; Dillaha, Theo

2010-01-01

Association of Escherichia coli and enterococci with particulates present in runoff from erodible soils has important implications for modeling the fate and transport of bacteria from agricultural sources and in the selection of management practices to reduce bacterial movement to surface waters. Three soils with different textures were collected from the Ap horizon (silty loam, silty clay loam, and loamy fine sand), placed in portable box plots, treated with standard cowpats, and placed under a rainfall simulator. Rainfall was applied to the plots until saturation-excess flow occurred for 30 min, and samples were collected 10, 20, and 30 min after initiation of the runoff event. The attachment of E. coli and enterococci to particles present in runoff was determined by a screen filtration and centrifugation procedure. Percentage of E. coli and enterococci attached to particulates in runoff ranged from 28 to 49%, with few statistically significant differences in attachment among the three soils. Similar partitioning release patterns were observed between E. coli and enterococci from the silty loam (r = 0.57) and silty clay loam soils (r = 0.60). At least 60% of all attached E. coli and enterococci were associated particles within an 8- to 62-microm particle size category. The results indicate that the majority of fecal bacteria attach to and are transported with manure colloids in sediment-laden flow regardless of the soil texture.

Gentamicin binds to the megalin receptor as a competitive inhibitor using the common ligand binding motif of complement type repeats

DEFF Research Database (Denmark)

Dagil, Robert; O'Shea, Charlotte; Nykjær, Anders

2013-01-01

megalin and investigated its interaction with gentamicin. Using NMR titration data in HADDOCK, we have generated a three-dimensional model describing the complex between megalin and gentamicin. Gentamicin binds to megalin with low affinity and exploits the common ligand binding motif previously described...... to megalin is highly similar to gentamicin binding to calreticulin. We discuss the impact of this novel insight for the future structure-based design of gentamicin antagonists....

Multidrug Resistance in Infants and Children

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Gian Maria Pacifici

2018-02-01

Full Text Available Bacterial infections may cause disease and death. Infants and children are often subject to bacterial infections. Antimicrobials kill bacteria protecting the infected patients andreducing the risk of morbidity and mortality caused by bacteria. The antibiotics may lose their antibacterial activity when they become resistant to a bacteria. The resistance to different antibiotics in a bacteria is named multidrug-resistance. Gram-negative bacilli, especially Escherichia coli, Klebsiella, Enterobacter, Salmonella, Shigella, Pseudomonas, Streptococcus, and Haemophilus influenzae type b, may become resistant. Amikacin ampicillin, amoxicillin, amoxiclav, cefuroxime, cefotaxime, ceftazidime, cefoperazone tetracycline, chloramphenicol, ciprofloxacin, and gentamicin may cause bacterial-resistance. Resistance to bacteria for several pathogens makes complications in the treatment of infections caused by them. Salmonella strains may become resistant to ampicillin, cephalotin, ceftriaxone, gentamicin, amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline. Shigella strains may become resistant to ampicillin, cotrimoxazole, chloramphenicol, and streptomycin. Multidrug-resistance of Streptococcus pneumoniae may be due to β-lactams, macrolides, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole. Multidrug-resistance of Pseudomonas aeruginosa may become resistant to β-lactams, chloramphenicol, trimethoprim-sulfamethoxazole, and tetracycline. The antibacterial activity against Haemophilus strains may occur with ampicillin, sulbactam-ampicillin, trimethoprim-sulfamethoxazole, gentamicin, chloramphenicol, and ciprofloxacin. Multidrug-resistance of the Klebsiella species may be due with ampicillin, cefotaxime, cefuroxime, co-amxilav, mezlocillin, chloramphenicol, gentamicin, and ceftazidime. Multidrug-resistance of Escherichia coli may be caused by ampicillin, cotrimoxazole, chloramphenicol, ceftriaxone, and ceftazidime. Vibrio

Antimicrobial Susceptibility Patterns of Enterococcus faecalis and Enterococcus faecium Isolated from Poultry Flocks in Germany.

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Maasjost, J; Mühldorfer, K; Cortez de Jäckel S; Hafez, H M

2015-03-01

Between 2010 and 2011, 145 Enterococcus isolates (Enterococcus faecalis, n = 127; Enterococcus faecium, n = 18) were collected during routine bacteriologic diagnostics from broilers, layers, and fattening turkeys in Germany showing various clinical signs. The susceptibility to 24 antimicrobial agents was investigated by broth microdilution test to determine minimum inhibitory concentrations (MICs). All E. faecalis isolates (n = 127) were susceptible to the beta-lactam antibiotics ampicillin, amoxicillin-clavulanic acid, and penicillin. Corresponding MIC with 50% inhibition (MIC50) and MIC with 90% inhibition (MIC90) values of these antimicrobial agents were at the lower end of the test range (≤ 4 μg/ml). In addition, no vancomycin-resistant enterococci (VRE) were found. High resistance rates were identified in both Enterococcus species for lincomycin (72%-99%) and tetracycline (67%-82%). Half or more than half of Enterococcus isolates were resistant to gentamicin (54%-72%) and the macrolide antibiotics erythromycin (44%-61%) and tylosin-tartate (44%-56%). Enterococcus faecalis isolated from fattening turkeys showed the highest prevalence of antimicrobial resistance compared to other poultry production systems. Eighty-nine out of 145 Enterococcus isolates were resistant to three or more antimicrobial classes. Again, turkeys stood out with 42 (8 1%) multiresistant isolates. The most-frequent resistance patterns of E. faecalis were gentamicin, lincomycin, and tetracycline in all poultry production systems.

Genetic Determinants of High-Level Oxacillin Resistance in Methicillin-Resistant Staphylococcus aureus.

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Pardos de la Gandara, Maria; Borges, Vitor; Chung, Marilyn; Milheiriço, Catarina; Gomes, João Paulo; de Lencastre, Herminia; Tomasz, Alexander

2018-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA - or a mecC -mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications, we identified the genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC -carrying MRSA strain LGA251. Here, we sought to test whether or not the same genetic determinants also contribute to the resistant phenotype of highly and homogeneously resistant (H*R) derivatives of a major contemporary MRSA clone, USA300. We found that the resistance phenotype was linked to six genes ( fruB , gmk , hpt , purB , prsA , and relA ), which were most frequently targeted among the analyzed 20 H*R strains (one mutation per clone in 19 of the 20 H*R strains). Besides the strong parallels with our previous findings (five of the six genes matched), all but one of the repeatedly targeted genes were found to be linked to guanine metabolism, pointing to the key role that this pathway plays in defining the level of antibiotic resistance independent of the clonal type of MRSA. Copyright © 2018 American Society for Microbiology.

Gentamicin- and Ciprofloxacin-Resistant Enterobacteriaceae in Cattle Farms in Israel: Risk Factors for Carriage and the Effect of Microbiological Methodology on the Measured Prevalence.

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Adler, Amos; Sturlesi, Na'ama; Fallach, Noga; Zilberman-Barzilai, Deniz; Hussein, Omar; Blum, Shlomo E; Klement, Eyal; Schwaber, Mitchell J; Carmeli, Yehuda

2017-07-01

Our objectives were to establish a methodology for surveillance of ciprofloxacin-resistant Enterobacteriaceae and gentamicin-resistant Enterobacteriaceae (CPRE and GNRE, respectively) in cattle and to study the prevalence and risk factors for carriage of these bacteria in a national survey. This was a point prevalence study conducted from July to October 2013 in Israel. Stool samples were collected from 1,226 cows in 123 sections of 40 farms of all production types. The number of CPRE- and GNRE-positive cows was highest in quarantine stations and fattening farms and was lowest in pasture farms (p 25 months) and highest in calves (<4 months) (p < 0.001). In bivariate analysis, other variables that were significant risk factors for CPRE and GNRE carriage included fewer troughs, crowding, lack of manure cleaning, and recent arrival of new calves. Antimicrobial prophylaxis was given almost exclusively to calves and was associated with a higher prevalence of carriers (p < 0.001). Compared to the use of nonselective media (MacConkey agar alone), the use of selective media (MacConkey agar with 10 μg/ml of ciprofloxacin or 5 μg/ml of gentamicin) increased the sensitivity of screening for CPRE and GNRE by 6.6- and 13.5-fold, respectively. CPRE and GNRE were identified in 609 (49.7%) and 840 (68.5%) samples, respectively. This study provides novel data regarding both the epidemiology of CPRE and GNRE carriage in livestock and the microbiological methodology for their surveillance.

Could edaravone prevent gentamicin ototoxicity? An experimental study.

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Turan, M; Ciğer, E; Arslanoğlu, S; Börekci, H; Önal, K

2017-02-01

Clinical application of gentamicin may cause nephrotoxicity and ototoxicity. Our study is the first study to investigate the protective effects of edaravone against the gentamicin-induced ototoxicity. We investigated the protective effect of intraperitoneal (i.p.) edaravone application against gentamicin-induced ototoxicity in guinea pigs. Fourteen guinea pigs were divided into two equal groups consisting of a control group and a study group. One-hundred sixty milligrams per kilogram subcutaneous gentamicin and 0.3 mL i.p. saline were applied simultaneously once daily to seven guinea pigs in the control group (group 1). One-hundred sixty milligrams per kilogram gentamicin was applied subcutaneously and 3 mg/kg edaravone was applied intraperitoneally once daily for 7 days simultaneously to seven guinea pigs in the study group (group 2). Following the drug application, auditory brainstem response measurements were performed for the left ear on the 3rd and 7th days. Hearing threshold values of the group 1 and group 2 measured in the 3rd day of the study were detected as 57.14 ± 4.88 and 82.86 ± 7.56, respectively. This difference was statistically significant ( p edaravone-administered group 2 and that of group 1 without edaravone was found. These differences show that systemic edaravone administration could diminish ototoxic effects of gentamicin and the severity of the hearing loss.

Effect of Helichrysum plicatum DC. subsp. plicatum ethanol extract on gentamicin-induced nephrotoxicity in rats.

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Apaydin Yildirim, Betul; Kordali, Saban; Terim Kapakin, Kubra Asena; Yildirim, Fatih; Aktas Senocak, Esra; Altun, Serdar

2017-06-01

The aim of this study was to evaluate the possible therapeutic or protective effects of Helichrysum plicatum DC. subsp. plicatum ethanol extract (HPE) against gentamicin-induced nephrotoxicity. Thirty-six Sprague Dawley male rats weighing between 200 and 250 g were used as live material. They were formed into six groups containing 6 rats each and were allowed to adapt to laboratory conditions for 7 d. Group I: control, 5% DMSO intraperitoneal (i.p.); Group II: HPE 100 mg/(kg·d) i.p.; Group III: HPE 200 mg/(kg·d) i.p.; Group IV: gentamicin as 80 mg/(kg·d) i.p.; Group V: gentamicin as 80 mg/(kg·d) i.p.+HPE 100 mg/(kg·d) i.p.; and Group VI: gentamicin as 80 mg/(kg·d) i.p.+HPE 200 mg/(kg·d) i.p. for 8 d. Following treatment, serum, liver, and kidney tissues were used to assess blood urea nitrogen (BUN), creatinine, enzymatic and non-enzymatic antioxidants, and lipid peroxidation. Gentamicin significantly increased serum BUN, creatinin, and liver and kidney levels of malondialdehyde (MDA). It also decreased the activity of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD). Treatment with the HPE 100 mg/kg reversed gentamicin-induced alterations as evidenced by decreased serum BUN and creatinin, liver and kidney oxidant marker, and tubular necrosis as well as by an increase in antioxidant enzymes. It was found that HPE 200 mg/kg significantly increased liver and kidney tissue MDA levels in nephrotoxicity in rats. As a result, these findings support the proposition that HPE in 100 mg/kg dose demonstrates in the kidney and liver as free radicals and scavenger to prevent the toxic effects of gentamicin in both the biochemical and histopathology parameters.

Genome Sequencing Reveals the Environmental Origin of Enterococci and Potential Biomarkers for Water Quality Monitoring

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Enterococci are common members of the gut microbiome and frequent causative agents of nosocomial infection. Because of their enteric lifestyle and ease of culturing, enterococci have been used worldwide as indicators of fecal pollution of waters. However, enterococci were recentl...

Antimicrobial resistance in faecal samples from buffalo, wildebeest and zebra grazing together with and without cattle in Tanzania

DEFF Research Database (Denmark)

Katakweba, A. A. S.; Møller, K. S.; Muumba, J.

2015-01-01

number of resistant Escherichia coli and Enterococci than cattle, but with no general influence in wild life of co-grazing with cattle. Vancomycin-resistant Enterococci were detected in wild life samples, and E. coli resistant to cefotaxime and enrofloxacin were observed among isolates from all wild life...

Genomic organization of a vancomycin-resistant staphylococcus aureus

International Nuclear Information System (INIS)

Mirani, A.Z.; Jamil, N.

2013-01-01

Objective: To study the genomic organization of vancomycin resistance in a local isolate of vancomycin resistant Staphylococcus aureus (VRSA). Study Design: Experimental study. Place and Duration of Study: Department of Microbiology, University of Karachi, January 2008 through December 2010. Methodology: A vancomycin-resistant Staphylococcus aureus (VRSA-CP2) isolate (MIC 16 mu g/ml) was isolated from a local hospital of Karachi. Species identification was confirmed by Gram staining, standard biochemical tests and PCR amplification of the nuc gene. The vancomycin MIC was re-confirmed by E-test. For the genetic determination of vancomycin resistance, in-vitro amplification of vanA cassette was performed by using plasmid DNA of CP2, CP2's transformant as template on MWG Thermo-Cycler. Amplified products of vanR, vanS, vanH, vanA, vanY, orf2, orf1D, orf2E, orf-Rev and IS element genes were subjected to Sanger's electrophoresis based sequence determination using specific primers. The Basic Local Alignment Search Tool (BLAST) algorithm was used to identify sequences in GenBank with similarities to the vanA cassette genes. Results: The vancomycin-resistant isolate CP2 was found to be resistant to oxacillin, chloramphenicol, erythromycin, rifampicin, gentamicin, tetracycline and ciprofloxacin, as well. The isolate CP2 revealed four bands: one of large molecular size approx 56.4 kb and three of small size approx 6.5 kb, approx 6.1 kb and approx 1.5 kb by agarose gel electrophoresis indicating the presence of 3 plasmids. The plasmid DNA of isolate CP2 was analyzed by PCR for the presence of the van cassettes with each of the vanA , vanB and vanC specific primers. It carried vanA cassette, which comprises of vanR, vanS, vanH, vanA, vanY, and orf2. The vanA cassette of isolate CP2 also carried an insertion element (IS). However, it did not show the PCR product for orf1. Vancomycin resistance was successfully transferred from the donor CP2 to a vancomycin-sensitive recipient S

Acquired Bartter syndrome following gentamicin therapy.

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Singh, J; Patel, M L; Gupta, K K; Pandey, S; Dinkar, A

2016-01-01

Aminoglycoside nephrotoxicity may manifest as nonoliguric renal failure or tubular dysfunction, such as Fanconi-like syndrome, Bartter-like syndrome (BS), or distal renal tubular acidosis. We report a case who developed severe renal tubular dysfunction on the the 7 th day of gentamicin therapy, resulting in metabolic alkalosis, refractory hypokalemia, hypocalcemia, hypomagnesemia, and polyuria. The patient was diagnosed as a case of transient BS associated with gentamicin exposure. The patient recovered with conservative management.

Lack of protection against gentamicin ototoxicity by auditory conditioning with noise

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Alex Strose

2014-10-01

Full Text Available INTRODUCTION: Auditory conditioning consists of the pre-exposure to low levels of a potential harmful agent to protect against a subsequent harmful presentation. OBJECTIVE: To confirm if conditioning with an agent different from the used to cause the trauma can also be effective. METHOD: Experimental study with 17 guinea pigs divided as follows: group Som: exposed to 85 dB broadband noise centered at 4 kHz, 30 minutes a day for 10 consecutive days; group Cont: intramuscular administration of gentamicin 160 mg/kg a day for 10 consecutive days; group Expt: conditioned with noise similarly to group Som and, after each noise presentation, received gentamicin similarly to group Cont. The animals were evaluated by distortion product otoacoustic emissions (DPOAEs, brainstem auditory evoked potentials (BAEPs and scanning electron microscopy. RESULTS: The animals that were conditioned with noise did not show any protective effect compared to the ones that received only the ototoxic gentamicin administration. This lack of protection was observed functionally and morphologically. CONCLUSION: Conditioning with 85 dB broadband noise, 30 min a day for 10 consecutive days does not protect against an ototoxic gentamicin administration of 160 mg/kg a day for 10 consecutive days in the guinea pig.

Prevalence, seasonality, and growth of enterococci in raw and pasteurized milk in Victoria, Australia.

Science.gov (United States)

McAuley, Catherine M; Britz, Margaret L; Gobius, Kari S; Craven, Heather M

2015-12-01

This study investigated the prevalence, seasonality, and species variety of enterococci present in raw milk factory silos and pasteurized milk in 3 dairying regions in Victoria, Australia, over a 1-yr period. Additionally, the growth ability of thermoduric enterococci isolated in this study (Enterococcus faecalis, E. faecium, E. hirae, and E. durans) was determined in milk at temperatures likely to occur during storage, transport, and distribution, and before domestic consumption (4 and 7°C). Enterococci were detected in 96% of 211 raw milk samples, with an average count of 2.48 log10 cfu/mL. Counts were significantly lower in winter than summer (average 1.84 log10 cfu/mL) and were different between factories but not regions. Enterococcus faecalis was the most prevalent species isolated from raw milk in every factory, comprising between 61.5 and 83.5% of enterococcal species across each season. Enterococci were detected in lower numbers in pasteurized milk than in raw milk and were below the limit of detection on spread plates (pasteurization. Residual viable cells were only detected following enrichment using 100-mL samples of milk, with 20.8% of the samples testing positive; this equated to a decrease in the average raw milk enterococci count of >4 log10 cfu/mL following pasteurization. Although E. faecalis predominated in raw milk and E. durans was found in only 2.9% of raw milk samples, E. durans was the most prevalent species detected in pasteurized milk. The detection of enterococci in the pasteurized milk did not correlate with higher enterococci counts in the raw milk. This suggested that the main enterococci populations in raw milk were heat-sensitive and that thermoduric enterococci survived pasteurization in a small numbers of instances. All of the thermoduric enterococci that were assessed for growth at likely refrigeration temperatures were able to grow at both 4 and 7°C in sterile milk, with generation times of 35 to 41h and 16 to 22h, respectively

Methicillin-susceptible and -resistant Staphylococcus aureus with high-level antiseptic and low-level mupirocin resistance in Malaysia.

Science.gov (United States)

Ghasemzadeh-Moghaddam, Hamed; van Belkum, Alex; Hamat, Rukman Awang; van Wamel, Willem; Neela, Vasanthakumari

2014-10-01

The prevalence and spread of mupirocin and antiseptic resistance among colonizing and infectious Staphylococcus aureus were determined. S. aureus isolated from anterior nares and infection sites of patients hospitalized in the largest tertiary care referral hospital in Malaysia was investigated for mupirocin and antiseptic susceptibility testing, and for PCR detection of mupA, qacA/B, and smr genes. Twelve isolates showed resistance to mupirocin by disk diffusion, of which 10 (3.8%) harbored the mupA gene. Minimum inhibitory concentrations (MICs) ranged from 64 to 768 μg/ml for mupA positive and below 46 μg/ml for negative isolates. The mupA was more common among ST239 isolates (70%). The qacA/B was carried in 67 out of 95 methicillin-resistant Staphylococcus aureus (MRSA) (70.5%) and 3 out of 164 methicillin-susceptible Staphylococcus aureus (MSSA) (1.8%), while smr was carried in 6 out of 95 MRSA (6.3%) strains. MICs ranged from 3.9 to 15.6 μg/ml for benzethonium chloride (BTC) and benzalkonium chloride (BKC), and from 10.3 to 20.7 μg/ml for chlorhexidine digluconate (CHG). Isolates with qacA/B and smr or qacA/B alone showed higher MIC (20.7 μg/ml for CHG and 15.6 μg/ml for BTC and BKC) than the isolates that lacked antiseptic resistance genes (10.3 μg/ml for CHG and 3.9 μg/ml for BTC and BKC). In 16 cases, ST239 was isolated from the infection site and the nares simultaneously, and shared identical resistance patterns (qacAB or qacAB+smr), suggesting possible endogenous infection. Spread of low-level mupirocin resistance expressing ST239 MRSA and high-level resistance expressing emerging ST1, co-existing with antiseptic-resistant genes showing elevated MICs, should be monitored for effective infection control.

Electrolyte composition of renal tubular cells in gentamicin nephrotoxicity

International Nuclear Information System (INIS)

Matsuda, O.; Beck, F.X.; Doerge, A.T.; Thurau, K.

1988-01-01

The effect of long-term gentamicin administration on sodium, potassium, chloride and phosphorus concentrations was studied in individual rat renal tubular cells using electron microprobe analysis. Histological damage was apparent only in proximal tubular cells. The extent of damage was only mild after 7 days of gentamicin administration (60 mg/kg body wt/day) but much more pronounced after 10 days. GFR showed a progressive decline during gentamicin treatment. In non-necrotic proximal tubular cells, sodium was increased from 14.6 +/- 0.3 (mean +/- SEM) in controls to 20.6 +/- 0.4 after 7 and 22.0 +/- 0.8 mmol/kg wet wt after 10 days of gentamicin administration. Chloride concentration was higher only after 10 days (20.6 +/- 0.6 vs. 17.3 +/- 0.2 mmol/kg wet wt). Both cell potassium and phosphorus concentrations were diminished by 6 and 15, and by 8 and 25 mmol/kg wet wt after 7 and 10 days of treatment, respectively. In contrast, no major alterations in distal tubular cell electrolyte concentrations could be observed after either 7 or 10 days of gentamicin administration. As in proximal tubular cells, distal tubular cell phosphorus concentrations were, however, lowered by gentamicin treatment. These results clearly indicate that gentamicin exerts its main effect on proximal tubular cells. Decreased potassium and increased sodium and chloride concentrations were observed in proximal tubular cells exhibiting only mild histological damage prior to the onset of advanced tissue injury. Necrotic cells, on the other hand, showed widely variable intracellular electrolyte concentration patterns

Acquired Bartter syndrome following gentamicin therapy

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J Singh

2016-01-01

Full Text Available Aminoglycoside nephrotoxicity may manifest as nonoliguric renal failure or tubular dysfunction, such as Fanconi-like syndrome, Bartter-like syndrome (BS, or distal renal tubular acidosis. We report a case who developed severe renal tubular dysfunction on the the 7 th day of gentamicin therapy, resulting in metabolic alkalosis, refractory hypokalemia, hypocalcemia, hypomagnesemia, and polyuria. The patient was diagnosed as a case of transient BS associated with gentamicin exposure. The patient recovered with conservative management.

Effect of cyclooxygenase inhibitors on gentamicin-induced nephrotoxicity in rats.

Science.gov (United States)

Hosaka, E M; Santos, O F P; Seguro, A C; Vattimo, M F F

2004-07-01

The frequent use of nonsteroidal anti-inflammatory drugs (NSAID) in combination with gentamicin poses the additional risk of nephrotoxic renal failure. Cyclooxygenase-1 (COX-1) is the main enzyme responsible for the synthesis of renal vasodilator prostaglandins, while COX-2 participates predominantly in the inflammatory process. Both are inhibited by non-selective NSAID such as indomethacin. Selective COX-2 inhibitors such as rofecoxib seem to have fewer renal side effects than non-selective inhibitors. The objective of the present study was to determine whether the combined use of rofecoxib and gentamicin can prevent the increased renal injury caused by gentamicin and indomethacin. Male Wistar rats (250-300 g) were treated with gentamicin (100 mg/kg body weight, ip, N = 7), indomethacin (5 mg/kg, orally, N = 7), rofecoxib (1.4 mg/kg, orally, N = 7), gentamicin + rofecoxib (100 and 1.4 mg/kg, respectively) or gentamicin + indomethacin (100 and 5 mg/kg, respectively, N = 8) for 5 days. Creatinine clearance and alpha-glutathione-S-transferase concentrations were used as markers of renal injury. Animals were anesthetized with ether and sacrificed for blood collection. The use of gentamicin plus indomethacin led to worsened renal function (0.199 +/- 0.019 ml/min), as opposed to the absence of a nephrotoxic effect of rofecoxib when gentamicin plus rofexicob was used (0.242 +/- 0.011 ml/min). These results indicate that COX-2-selective inhibitors can be used as an alternative treatment to conventional NSAID, especially in situations in which risk factors for nephrotoxicity are present.

Effect of cyclooxygenase inhibitors on gentamicin-induced nephrotoxicity in rats

Directory of Open Access Journals (Sweden)

Hosaka E.M.

2004-01-01

Full Text Available The frequent use of nonsteroidal anti-inflammatory drugs (NSAID in combination with gentamicin poses the additional risk of nephrotoxic renal failure. Cyclooxygenase-1 (COX-1 is the main enzyme responsible for the synthesis of renal vasodilator prostaglandins, while COX-2 participates predominantly in the inflammatory process. Both are inhibited by non-selective NSAID such as indomethacin. Selective COX-2 inhibitors such as rofecoxib seem to have fewer renal side effects than non-selective inhibitors. The objective of the present study was to determine whether the combined use of rofecoxib and gentamicin can prevent the increased renal injury caused by gentamicin and indomethacin. Male Wistar rats (250-300 g were treated with gentamicin (100 mg/kg body weight, ip, N = 7, indomethacin (5 mg/kg, orally, N = 7, rofecoxib (1.4 mg/kg, orally, N = 7, gentamicin + rofecoxib (100 and 1.4 mg/kg, respectively or gentamicin + indomethacin (100 and 5 mg/kg, respectively, N = 8 for 5 days. Creatinine clearance and alpha-glutathione-S-transferase concentrations were used as markers of renal injury. Animals were anesthetized with ether and sacrificed for blood collection. The use of gentamicin plus indomethacin led to worsened renal function (0.199 ± 0.019 ml/min, as opposed to the absence of a nephrotoxic effect of rofecoxib when gentamicin plus rofexicob was used (0.242 ± 0.011 ml/min. These results indicate that COX-2-selective inhibitors can be used as an alternative treatment to conventional NSAID, especially in situations in which risk factors for nephrotoxicity are present.

Investigation and Treatment of Fusidic Acid Resistance Among Methicillin-Resistant Staphylococcal Isolates from Egypt.

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Abouelfetouh, Alaa; Kassem, Mervat; Naguib, Marwa; El-Nakeeb, Moustafa

2017-01-01

Methicillin resistance among staphylococci isolated from patients in northern Egypt has escalated alarmingly in the past decade. Data about the prevalence of fusidic acid (FA) resistance in Egyptian clinical isolates are limited. This work investigates the prevalence and mechanism of FA resistance among 81 methicillin-resistant staphylococcal isolates from major hospitals of Alexandria, Egypt. Some combinations for treating infections due to resistant isolates were studied. Twenty-six isolates (32.1%) were FA resistant (minimum inhibitory concentrations [MICs] = 2-1,024 μg/ml), and fusB and fusC genes coding for FA resistance were detected in 30.77% and 34.62% of the FA-resistant strains, respectively. One highly resistant isolate, S502 (MIC = 1,024 μg/ml), possessed both genes. Plasmid curing resulted in fusB loss and MIC decrease by 16-64 folds. Conjugation caused acquisition of FA resistance among susceptible isolates. Serial passages in subinhibitory FA concentrations produced mutants with increased MIC by 4-32 folds. The combination of FA with rifampin, gentamicin, or ampicillin/sulbactam, in a subinhibitory concentration, was synergistic against the isolates, including serial passage mutants, decreasing number of survivors by an average of 2-4 logs. A relatively moderate rate of FA resistance was detected in Alexandria hospitals. Combination therapy with gentamicin, rifampin, or ampicillin/sulbactam is crucial to preserve the effectiveness of FA.

Synergistic effects of the combination of galangin with gentamicin against methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Lee, Young-Seob; Kang, Ok-Hwa; Choi, Jang-Gi; Oh, You-Chang; Chae, Hee-Sung; Kim, Jong Hak; Park, Hyun; Sohn, Dong Hwan; Wang, Zheng-Tao; Kwon, Dong-Yeul

2008-06-01

The antimicrobial killing activity toward methicillin-resistant Staphylococcus aureus (MRSA) has been a serious emerging global issue. New effective antimicrobials and/or new approaches to settle this issue are urgently needed. The oriental herb, Alpinia officinarum, has been used in Korea for several hundreds of years to treat various infectious diseases. As it is well known, one of the active constituents of Alpinia officinarum is galangin. Against the 17 strains, the minimum inhibitory concentrations (MICs) of galangin (GAL) were in the range of 62.5 ~ 125 microg/ml, and the MICs of gentamicin (GEN) ranged from 1.9 microg/ml to 2,000 microg/ml. The fractional inhibitory concentrations (FICs) of GAL, in combination with GEN, against 3 test strains were 0.4, 3.9, and 250 microg/ml, and were all 15.62 microg/ml in GEN. The FIC index showed marked synergism in the value range of 0.19 to 0.25. By determining time-kill curves, also confirmed the low synergism of the GAL and GEN combination against 4 h, 8 h, 12 h, and 24 h cultured MRSA. The time-kill study results indicated a low synergistic effect against 3 test strains. Thus, the mixture of GAL and GEN could lead to the development of new combination antibiotics against MRSA infection.

Three surveillance strategies for vancomycin-resistant enterococci in hospitalized patients: detection of colonization efficiency and a cost-effectiveness model.

Science.gov (United States)

Lee, Todd A; Hacek, Donna M; Stroupe, Kevin T; Collins, Susan M; Peterson, Lance R

2005-01-01

To evaluate the cost-effectiveness and detection sensitivity associated with three active surveillance strategies for the identification of patients harboring vancomycin-resistant enterococci (VRE) to determine which is the most medically and economically useful. Culture for VRE from 200 consecutive stool specimens submitted for Clostridium difficile culture. Following this, risk factors were assessed for patients whose culture yielded VRE, and a cost-effectiveness evaluation was performed using a decision analytic model with a probabilistic analysis. A 688-bed, tertiary-care facility in Chicago, Illinois, with approximately 39,000 annual admissions, 7,000 newborn deliveries, 56,000 emergency department visits, and 115,000 home care and 265,000 outpatient visits. All stool specimens submitted to the clinical microbiology laboratory for C. difficile culture from hospital inpatients. From 200 stool samples submitted for C. difficile testing, we identified 5 patients with VRE in non-high-risk areas not screened as part of our routine patient surveillance. Medical record review revealed that all 5 had been hospitalized within the prior 2 years. Three of 5 had a history of renal impairment. The strategy that would involve screening the greatest number of patients (all those with a history of hospital admission in the prior 2 years) resulted in highest screening cost per patient admitted (dollars 2.48), lower per patient admission costs (dollars 480), and the best survival rates. An expanded VRE surveillance program that encompassed all patients hospitalized within the prior 2 years was a cost-effective screening strategy compared with a more traditional one focused on high-risk units.

Measurement of plasma gentamicin concentrations postchemical ciliary body ablation in dogs with chronic glaucoma.

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Rankin, Amy J; Lanuza, Rick; KuKanich, Butch; Crumley, William C; Pucket, Jonathan D; Allbaugh, Rachel A; Meekins, Jessica M

2016-01-01

To investigate the absorption of gentamicin into the plasma after an intravitreal injection in dogs and to report the success rate of this procedure in lowering the intraocular pressure. Twenty-four client-owned dogs with chronic, end-stage glaucoma. Dogs received a unilateral (22) or bilateral (2) intravitreal injection of 25-40 mg of gentamicin (mean ± SD dose 2.57 ± 1.65 mg/kg and range 0.61-7.50 mg/kg) and 1 mg of dexamethasone per eye. Blood samples were collected at various time points following the intravitreal injection. Plasma concentrations of gentamicin were determined by liquid chromatography and mass spectrometry. The total plasma concentration of gentamicin ranged from 0.21 to 9.71 μg/mL (mean ± SD 2.15 ± 2.03). The mean gentamicin CMAX was 2.29 μg/mL at 2.54 h with a terminal half-life of 9.8 h. The success rate of the chemical ablation procedure was 86.4% (19/22 eyes) in dogs that had at least 1 month of follow-up. Intravitreal injection of gentamicin in eyes with chronic glaucoma resulted in detectable plasma levels in dogs and was successful in lowering the intraocular pressure in 86.4% of the eyes after the first procedure. © 2015 American College of Veterinary Ophthalmologists.

High levels of macrolide-resistant Mycoplasma genitalium in Queensland, Australia.

Science.gov (United States)

Trembizki, Ella; Buckley, Cameron; Bletchly, Cheryl; Nimmo, Graeme R; Whiley, David M

2017-10-01

The macrolide azithromycin is recommended for treatment of Mycoplasma genitalium infection; however, M. genitalium strains possessing macrolide resistance-mediating mutations (MRMMs) are increasingly being reported. Here, we used the SpeeDx ResistancePlus MG kit, which provides simultaneous detection of M. genitalium and MRMMs, to assess MRMM carriage among M. genitalium infections in Queensland, Australia. Performance characteristics of the ResistancePlus MG kit for M. genitalium detection were compared to in-house PCR. Available M. genitalium PCR-positive (n=67) and negative (n=281) samples from the years 2011 to 2017 were tested using the SpeeDx ResistancePlus MG kit. In total, 63.6 % M. genitalium-positive samples were indicated to harbour MRMMs. The ResistancePlus MG method provided sensitivity and specificity of 97 and 99.6 % respectively compared to in-house PCR for M. genitalium detection. Such high levels of macrolide-resistant M. genitalium raise further concerns over future use of azithromycin for treatment of M. genitalium infection.

Antibiotics in animal feed and their role in resistance development

DEFF Research Database (Denmark)

Wegener, Henrik Caspar

2003-01-01

Animals and humans constitute overlapping reservoirs of resistance, and consequently use of antimicrobials in animals can impact on public health. For example, the occurrence of vancomycin-resistant enterococci in food-animals is associated with the use of avoparcin, a glycopeptide antibiotic used...... as a feed additive for the growth promotion of animals. Vancomycin-resistant enterococci and vancomycin resistance determinants can therefore spread from animals to humans. The bans on avoparcin and other antibiotics as growth promoters in the EU have provided scientists with a unique opportunity......, the effects on animal health and productivity have been very minor....

Instrumental characterization of the smectite clay–gentamicin hybrids

Indian Academy of Sciences (India)

This paper focusses on the intercalation of clay mineral with gentamicin (an aminoglycoside antibiotic). The smectite clay–gentamicin hybrids were prepared by a solution intercalation at 60°C and the process was carried out on unmodified smectite clay and on smectite after Na+ ionic activation. The resulting ...

21 CFR 524.1044a - Gentamicin ophthalmic solution.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentamicin ophthalmic solution. 524.1044a Section... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1044a Gentamicin ophthalmic solution. (a) Specifications. Each milliliter of sterile aqueous...

A risk modelling approach for setting microbiological limits using enterococci as indicator for growth potential of Salmonella in pork.

Science.gov (United States)

Bollerslev, Anne Mette; Nauta, Maarten; Hansen, Tina Beck; Aabo, Søren

2017-01-02

Microbiological limits are widely used in food processing as an aid to reduce the exposure to hazardous microorganisms for the consumers. However, in pork, the prevalence and concentrations of Salmonella are generally low and microbiological limits are not considered an efficient tool to support hygiene interventions. The objective of the present study was to develop an approach which could make it possible to define potential risk-based microbiological limits for an indicator, enterococci, in order to evaluate the risk from potential growth of Salmonella. A positive correlation between the concentration of enterococci and the prevalence and concentration of Salmonella was shown for 6640 pork samples taken at Danish cutting plants and retail butchers. The samples were collected in five different studies in 2001, 2002, 2010, 2011 and 2013. The observations that both Salmonella and enterococci are carried in the intestinal tract, contaminate pork by the same mechanisms and share similar growth characteristics (lag phase and maximum specific growth rate) at temperatures around 5-10°C, suggest a potential of enterococci to be used as an indicator of potential growth of Salmonella in pork. Elevated temperatures during processing will lead to growth of both enterococci and, if present, also Salmonella. By combining the correlation between enterococci and Salmonella with risk modelling, it is possible to predict the risk of salmonellosis based on the level of enterococci. The risk model used for this purpose includes the dose-response relationship for Salmonella and a reduction factor to account for preparation of the fresh pork. By use of the risk model, it was estimated that the majority of salmonellosis cases, caused by the consumption of pork in Denmark, is caused by the small fraction of pork products that has enterococci concentrations above 5logCFU/g. This illustrates that our approach can be used to evaluate the potential effect of different microbiological

Antibiotic resistance in children with complicated urinary tract infection

International Nuclear Information System (INIS)

Yildiz, B.; Kural, N.; Yarar, C.; Ak, I.; Akcar, N.

2007-01-01

Objective was to determine the resistance of antibiotics for complicated urinary tract infection (UTI), including urinary tract anomaly (UTA), for empirical antibiotic therapy of complicated UTI. Four hundred and twenty two urine isolates were obtained from 113 patients with recurrent UTI, who used prophylactic antibiotics between February 1999 and November 2004 in the Eskisehir Osmangazi University, Eskisehir, Turkey. Reflux was found to be most important predisposing factor for recurrent UTI (31.9%). Renal scar was detected more in patients with UTA than without UTA (59.2% versus 12.4%, p<0.05). Gram-negative organisms were dominant in patients with and without UTA (91.5% and 79.2%). Enterococci and Candida spp. were more prevalent in children with UTA than without UTA (p<0.001). Isolates were significantly more resistant to ampicillin, trimethoprim-sulfamethoxazole, amikacin, co-amoxiclav, ticarcillin-clvalanate and piperacillin-tazobactam in patients with UTA than without UTA. We found low resistance to ciprofloxacin and nitrofurantoin in UTI with and without UTA. Enterococci spp. was highly resistance to ampicillin and amikacin in patients with UTA. Aztreonam, meropenem and ciprofloxacin seemed to be the best choice for treatment of UTI with UTA due to Escherichia coli and Klebsiella spp. Nitrofurantoin and nalidixic acid may be first choice antibiotics for prophylaxis in UTI with and without UTA. The UTI with UTA caused by Enterococci spp. might not benefit from a combination of amikacin and ampicillin, it could be treated with glycopeptides. (author)

Antimicrobial Resistance and Resistance Genes in Aerobic Bacteria Isolated from Pork at Slaughter

DEFF Research Database (Denmark)

Li, Lili; Olsen, Rikke Heidemann; Ye, Lei

2016-01-01

The aim of this study was to investigate the phenotypic and genotypic antimicrobial resistance, integrons, and transferability of resistance markers in 243 aerobic bacteria recovered from pork at slaughter in the People's Republic of China. The organisms belonged to 22 genera of gram-negative bac......The aim of this study was to investigate the phenotypic and genotypic antimicrobial resistance, integrons, and transferability of resistance markers in 243 aerobic bacteria recovered from pork at slaughter in the People's Republic of China. The organisms belonged to 22 genera of gram......-negative bacteria (92.2%) and gram-positive bacteria (7.8%). High levels of resistance were detected to tetracycline, trimethoprim-sulfamethoxazole, and ampicillin (36.2 to 54.3%), and lower levels were detected to nitrofurantoin, cefotaxime, gentamicin, ciprofloxacin, and chloramphenicol (7.8 to 29.2%). Across.......6% of isolates contained class 1 integrons, and one isolate harbored class 2 integrons. Plasmid associated intI1 and androgen receptor– encoding genes were transferred into Escherichia coli J53 and E. coli DH5α by conjugation and transformation experiments, respectively. Our study highlights the importance...

Inactivation Effect of Antibiotic-Resistant Gene Using Chlorine Disinfection

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Takashi Furukawa

2017-07-01

Full Text Available The aim of this study was to elucidate the inactivation effects on the antibiotic-resistance gene (vanA of vancomycin-resistant enterococci (VRE using chlorination, a disinfection method widely used in various water treatment facilities. Suspensions of VRE were prepared by adding VRE to phosphate-buffered saline, or the sterilized secondary effluent of a wastewater treatment plant. The inactivation experiments were carried out at several chlorine concentrations and stirring time. Enterococci concentration and presence of vanA were determined. The enterococci concentration decreased as chlorine concentrations and stirring times increased, with more than 7.0 log reduction occurring under the following conditions: 40 min stirring at 0.5 mg Cl2/L, 20 min stirring at 1.0 mg Cl2/L, and 3 min stirring at 3.0 mg Cl2/L. In the inactivation experiment using VRE suspended in secondary effluent, the culturable enterococci required much higher chlorine concentration and longer treatment time for complete disinfection than the cases of suspension of VRE. However, vanA was detected in all chlorinated suspensions of VRE, even in samples where no enterococcal colonies were present on the medium agar plate. The chlorine disinfection was not able to destroy antibiotic-resistance genes, though it can inactivate and decrease bacterial counts of antibiotic-resistant bacteria (ARB. Therefore, it was suggested that remaining ARB and/or antibiotic-resistance gene in inactivated bacterial cells after chlorine disinfection tank could be discharged into water environments.

Antibacterial activity of oregano and sage plant extracts against decarboxylase-positive enterococci isolated from rabbit meat

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Ľubica Chrastinová

2013-02-01

Full Text Available The effect of plant extracts (sage, oregano against decarboxylase-positive enterococci from rabbit back limb meat  was reported in this study. Oregano plant extract inhibited the growth of all 34 tested enterococci (the inhibitory zones: 12 to 45 mm. The growth of the majority of strains  (n=23 was inhibited by oregano plant extract (the high size inhibitory zones (higher than 25 mm. The growth of 11 strains  was inhibited by oregano extract reaching medium size inhibitory zones (10 to 25mm. The most sensitive strain to oregano extract was E. faecium M7bA (45 mm. Sage extract was less active against tested enterococci (n=16  reaching lower inhibitory zones (up to 10 mm. doi:10.5219/239 Normal 0 21 false false false SK X-NONE X-NONE

Environmental Factors Correlated with Culturable Enterococci Concentrations in Tropical Recreational Waters: A Case Study in Escambron Beach, San Juan, Puerto Rico

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Abdiel E. Laureano-Rosario

2017-12-01

Full Text Available Enterococci concentration variability at Escambron Beach, San Juan, Puerto Rico, was examined in the context of environmental conditions observed during 2005–2015. Satellite-derived sea surface temperature (SST, turbidity, direct normal irradiance, and dew point were combined with local precipitation, winds, and mean sea level (MSL observations in a stepwise multiple regression analyses (Akaike Information Criteria model selection. Precipitation, MSL, irradiance, SST, and turbidity explained 20% of the variation in observed enterococci concentrations based upon these analyses. Changes in these parameters preceded increases in enterococci concentrations by 24 h up to 11 days, particularly during positive anomalies of turbidity, SST, and 480–960 mm of accumulated (4 days precipitation, which relates to bacterial ecology. Weaker, yet still significant, increases in enterococci concentrations were also observed during positive dew point anomalies. Enterococci concentrations decreased with elevated irradiance and MSL anomalies. Unsafe enterococci concentrations per US EPA recreational water quality guidelines occurred when 4-day cumulative precipitation ranged 481–960 mm; irradiance < 667 W·m−2; daily average turbidity anomaly >0.005 sr−1; SST anomaly >0.8 °C; and 3-day average MSL anomaly <−18.8 cm. This case study shows that satellite-derived environmental data can be used to inform future water quality studies and protect human health.

Punica granatum improves renal function in gentamicin-induced nephropathy in rats via attenuation of oxidative stress.

Science.gov (United States)

Mestry, Snehal N; Gawali, Nitin B; Pai, Sarayu A; Gursahani, Malvika S; Dhodi, Jayesh B; Munshi, Renuka; Juvekar, Archana R

2018-03-16

Gentamicin is widely used as an antibiotic for the treatment of gram negative infections. Evidences indicates that oxidative stress is involved in gentamicin-induced nephrotoxicity. In Ayurvedic medicine, Punica granatum Linn. is considered as 'a pharmacy unto itself". It has been claimed in traditional literature, to treat various kidney ailments due to its antioxidant potential. To explore the possible mechanism of action of methanolic extract of P.granatum leaves (MPGL) in exerting a protective effect on gentamicin-induced nephropathy. Animals were administered with gentamicin (80 mg/kg/day i.m.) and simultaneously with MPGL (100, 200 and 400 mg/kg p.o.) or metformin (100 mg/kg p.o.) for 8 days. A satellite group was employed in order to check for reversibility of nephrotoxic effects post discontinuation of gentamicin administration. At the end of the study, all the rats were sacrificed and serum-urine parameters were investigated. Antioxidant enzymes and tumor necrosis factor alpha (TNF-α) levels were determined in the kidney tissues along with histopathological examination of kidneys. Increase in serum creatinine, urea, TNF-α, lipid peroxidation along with fall in the antioxidant enzymes activity and degeneration of tubules, arterioles as revealed by histopathological examination confirmed the manifestation of nephrotoxicity caused due to gentamicin. Simultaneous administration of MPGL and gentamicin protected kidneys against nephrotoxic effects of gentamicin as evidenced from normalization of renal function parameters and amelioration of histopathological changes. Data suggests that MPGL attenuated oxidative stress associated renal injury by preserving antioxidant enzymes, reducing lipid peroxidation and inhibiting inflammatory mediators such as TNF-α. Copyright © 2017 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Published by Elsevier B.V. All rights reserved.

Optimising intraperitoneal gentamicin dosing in peritoneal dialysis patients with peritonitis (GIPD study

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Lipman Jeffrey

2009-12-01

Full Text Available Abstract Background Antibiotics are preferentially delivered via the peritoneal route to treat peritonitis, a major complication of peritoneal dialysis (PD, so that maximal concentrations are delivered at the site of infection. However, drugs administered intraperitoneally can be absorbed into the systemic circulation. Drugs excreted by the kidneys accumulate in PD patients, increasing the risk of toxicity. The aim of this study is to examine a model of gentamicin pharmacokinetics and to develop an intraperitoneal drug dosing regime that maximises bacterial killing and minimises toxicity. Methods/Design This is an observational pharmacokinetic study of consecutive PD patients presenting to the Royal Brisbane and Women's Hospital with PD peritonitis and who meet the inclusion criteria. Participants will be allocated to either group 1, if anuric as defined by urine output less than 100 ml/day, or group 2: if non-anuric, as defined by urine output more than 100 ml/day. Recruitment will be limited to 15 participants in each group. Gentamicin dosing will be based on the present Royal Brisbane & Women's Hospital guidelines, which reflect the current International Society for Peritoneal Dialysis Peritonitis Treatment Recommendations. The primary endpoint is to describe the pharmacokinetics of gentamicin administered intraperitoneally in PD patients with peritonitis based on serial blood and dialysate drug levels. Discussion The study will develop improved dosing recommendations for intraperitoneally administered gentamicin in PD patients with peritonitis. This will guide clinicians and pharmacists in selecting the most appropriate dosing regime of intraperitoneal gentamicin to treat peritonitis. Trial Registration ACTRN12609000446268

Radioimmunoassay, acetylating radio-enzymatic assay, and microbioassay of gentamicin: a comparative study

International Nuclear Information System (INIS)

Stevens, P.; Young, L.S.; Hewitt, W.L.

1975-01-01

Gentamicin is an aminoglycoside antibiotic widely used to treat gram-negative bacillary infections. Because it has a low therapeutic index, monitoring of serum levels may help to insure adequacy of dosage and avoid toxicity. Microbiological assays are relatively slow and can be complicated by the presence of other antimicrobials. Radioimmunoassay (RIA) and acetylating radio-enzymatic assay (ARA) are new methods for gentamicin assay which offer the following advantages: rapidity (less than 3 hours); no interference by other antibiotics; RIA is extremely sensitive and ARA is versatile (being useful in the measurement of other aminoglycosides). Correlation coefficients determined by linear regression analysis of assays on 36 patient samples performed in duplicate on 2 different days demonstrated no significant difference in measurement of gentamicin by each of the methods. Factors such as numbers of specimens, cost, and time involved will affect the decision of the method to be applied in individual laboratories. (U.S.)

Antibiotic resistance and virulence traits in clinical and environmental Enterococcus faecalis and Enterococcus faecium isolates.

Science.gov (United States)

Rathnayake, I U; Hargreaves, M; Huygens, F

2012-07-01

This study compared virulence and antibiotic resistance traits in clinical and environmental Enterococcus faecalis and Enterococcus faecium isolates. E. faecalis isolates harboured a broader spectrum of virulence determinants compared to E. faecium isolates. The virulence traits Cyl-A, Cyl-B, Cyl-M, gel-E, esp and acm were tested and environmental isolates predominantly harboured gel-E (80% of E. faecalis and 31.9% of E. faecium) whereas esp was more prevalent in clinical isolates (67.8% of E. faecalis and 70.4% of E. faecium). E. faecalis and E. faecium isolated from water had different antibiotic resistance patterns compared to those isolated from clinical samples. Linezolid resistance was not observed in any isolates tested and vancomycin resistance was observed only in clinical isolates. Resistance to other antibiotics (tetracycline, gentamicin, ciprofloxacin and ampicillin) was detected in both clinical and water isolates. Clinical isolates were more resistant to all the antibiotics tested compared to water isolates. Multi-drug resistance was more prevalent in clinical isolates (71.2% of E. faecalis and 70.3% of E. faecium) compared to water isolates (only 5.7% E. faecium). tet L and tet M genes were predominantly identified in tetracycline-resistant isolates. All water and clinical isolates resistant to ciprofloxacin and ampicillin contained mutations in the gyrA, parC and pbp5 genes. A significant correlation was found between the presence of virulence determinants and antibiotic resistance in all the isolates tested in this study (pantibiotic resistant enterococci, together with associated virulence traits, in surface recreational water could be a public health risk. Copyright © 2012 Elsevier GmbH. All rights reserved.

Study of Gentamicin Effect on Staphylococcus Aureus in the Presence of Electromagnetic Field

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Asghar Tanomand

2008-06-01

Full Text Available Introduction:  Nowadays  the  medical,  therapeutic  and  pharmacological  application  of  magnetic  fields  (MF  and  its  biological  effect  has  raised  question  about  the  safety  of  MF.  This  study  aimed  at  scrutinizing the effect of static MF on the resistance of S. aureus to antibiotic.  Materials and Methods: This prospective, case–control study was conducted to evaluate the effect of  low intensity (0.5 mT static MF on the growth rate and the antibiotic resistance of S. aureus sensitive to  gentamicin. The studied bacterium is a nosocomial type and the growth rate was calculated by colony  counting to understand the effect of MF on it. In the next stage, the rate of bacterial growth along with  the different concentration of antibiotic was studied and the Minimum Inhibitory Concentration (MIC  and Minimum Bactericidal Concentration (MBC were determined.  Results: It is concluded that the 0.5 mT MF didn't affect the growth rate of S. aureus after 24 and 48 hours.  The 0.5 mT MF induced a 50 percent decline of MIC and MBC of gentamicin after a 48 hour incubation (MIC  = 4 6g /cc, MBC = 8 6g /cc in the case group vs. MIC = 8 6g /cc, MBC = 16 6g /cc in the control group.  Conclusion: Low–intensity MF didn't affect the bacterial growth rate. However, the bactericidal effects  of gentamicin were greater in the presence of MF. It is possible to apply the static MF for enhancing the  effect of antibiotic on S. aureus.

Tritium Labeled Gentamicin C: II.- Bioradiactive Degradation Products of Gentamicin by Catalytic H2O-3H Exchange Reaction; Getamicina C Tritiada: II.- Productos de Degradacion Radiactivos y Bioactivos en el Intercambio Catalitico con H2O-3H

Energy Technology Data Exchange (ETDEWEB)

Suarez, C; Diaz, A; Paz, D; Jimeno, M L

1992-07-01

The main bio radioactive degradation products from catalytic hydrogen exchange of gentamicin C, (C1 + C2 + Cla) in basic form, are generated by N-demethylation in 3{sup -}N and 6-N positions. Their structures were confirmed by 1HNMR and 13CNMR. These derivatives were fractionated by chromatography on silica gel. Antibacterial activities were similar to those of the parent antibiotics. Tritium exchange, under vacuum or nitrogen, is highly increased (4:1) when gentamicin are in basic form. In contrast with gentamicin sulfate, hydrolytic sub products as gramine, genta mines, garosamine and purpurosamines are practically absent. To properly optimize the exchange process, the composition of the gentamicin C complex must be taken into account. The exchange decreases in the order C2 > C1> Cla. Because of 6'-N-demethyl gentamicin C1 is C2, the radiochemical yield of C2 appears enhanced in the H2O-3H exchange of a mixture of them. Radioactivity distribution among the components and subunits of these three gentamicin were studied by strong and mild hydrolysis, and by methanolysis. (Author) 18 refs.

Meningitis associated with Vancomycin resistant Enterococcus casseliflavus: First report

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Nilay Sefa Uçar

2011-12-01

Full Text Available Enterococci are present in the gastrointestinal system as normal floral components. In the past two decades membersof the genus Enterococcus have emerged as important nosocomial pathogens worldwide. Enterococci may cause arange of different disorders such as urinary tract, intraabdominal, and wound infections, as well as endocarditis, meningitisand bacteraemia. Nosocomial enterococcal meningitis is most commonly observed following ventriculoperitonealshunt operations. Vancomycin resistant enterococcus (VRE represents 30% of all enterococci infections.This report presents a vancomycin-resistant Enterococcus casseliflavus meningitis case in a 66-year-old patient withventriculoperitoneal shunt, which has not been reported in the literature before. Successful outcomes were obtainedwith daptomycin plus linezolid combined treatment in VRE meningitis. Treatment recommendations in VRE meningitisare also discussed in this article. J Microbiol Infect Dis 2011;1 (3:138-140

Once versus twice daily gentamicin dosing for infective endocarditis

DEFF Research Database (Denmark)

Buchholtz, Kristine; Larsen, Carsten Toftager; Schaadt, Bente

2011-01-01

Objectives: The aim of this randomized study was to investigate the effects of once versus twice daily gentamicin dosing on renal function and measures of infectious disease in a population with infective endocarditis (IE). Methods: Seventy-one IE patients needing gentamicin treatment according...

Decreased Expression of Na+/K+-ATPase, NHE3, NBC1, AQP1 and OAT in Gentamicin-induced Nephropathy

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Bae, Woo Kyun; Lee, JongUn; Park, Jeong Woo; Bae, Eun Hui; Ma, Seong Kwon; Kim, Suhn Hee

2008-01-01

The present study was aimed to determine whether there is an altered regulation of tubular transporters in gentamicin-induced nephropathy. Sprague-Dawley male rats (200~250 g) were subcutaneously injected with gentamicin (100 mg/kg per day) for 7 days, and the expression of tubular transporters was determined by immunoblotting and immunohistochemistry. The mRNA and protein expression of OAT was also determined. Gentamicin-treated rats exhibited significantly decreased creatinine clearance along with increased plasma creatinine levels. Accordingly, the fractional excretion of sodium increased. Urine volume was increased, while urine osmolality and free water reabsorption were decreased. Immunoblotting and immunohistochemistry revealed decreased expression of Na+/K+-ATPase, NHE3, NBC1, and AQP1 in the kidney of gentamicin-treated rats. The expression of OAT1 and OAT3 was also decreased. Gentamicin-induced nephropathy may at least in part be causally related with a decreased expression of Na+/K+-ATPase, NHE3, NBC1, AQP1 and OAT. PMID:19967075

Removal of micropollutants, facultative pathogenic and antibiotic resistant bacteria in a full-scale retention soil filter receiving combined sewer overflow.

Science.gov (United States)

Scheurer, Marco; Heß, Stefanie; Lüddeke, Frauke; Sacher, Frank; Güde, Hans; Löffler, Herbert; Gallert, Claudia

2015-01-01

Combined sewer systems collect surface runoff as well as wastewater of industrial and domestic origin. During periods of heavy rainfall the capacity of the sewer system is exceeded and the overflow is discharged into receiving waters without any treatment. Consequently, combined sewer overflow (CSO) is considered as a major source of water pollution. This study investigates the effectiveness of a retention soil filter (RSF) for the removal of micropollutants as well as facultative pathogenic and antibiotic resistant bacteria from CSO. The removal of organic group parameters like total organic carbon was excellent and the removal efficiency for micropollutants of the RSF and the wastewater treatment plant (WWTP), which treats wastewater of the same origin during dry and normal weather conditions, was comparable. Compounds of high environmental concern like estrogens or certain pharmaceuticals, e.g. diclofenac, were completely eliminated or removed to a high degree during RSF passage. RSF treatment also reduced the number of E. coli, enterococci and staphylococci by 2.7, 2.2 and 2.4 log-units (median values), respectively. Obviously, some Staphylococcus species can better adapt to the conditions of the RSF than others as a shift of the abundance of the different species was observed when comparing the diversity of staphylococci obtained from the RSF influent and effluent. RSF treatment also decreased the absolute number of antibiotic resistant bacteria. The percentage of antibiotic resistant E. coli and staphylococci isolates also decreased during passage of the RSF, whereas the percentage of resistant enterococci did not change. For E. coli ampicillin and for enterococci and staphylococci erythromycin determined the antibiotic resistance level. The results demonstrate that RSFs can be considered as an adequate treatment option for CSO. The performance for the removal of micropollutants is comparable with a medium sized WWTP with conventional activated sludge

Antibacterial susceptibility patterns and cross-resistance of methicillin resistant and sensitive Staphyloccus aureus isolated from the hospitalized patients in Shiraz, Iran

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Aziz Japoni

2010-10-01

Full Text Available Nosocomial infections caused by methicillin-resistant staphylococci (MRSA pose a serious problem in many countries. This study aimed to determine the antibacterial susceptibility patterns of methicillin sensitive and resistant Staphylococcus aureus isolates from the hospitalized patients. Totally 356 isolates of Staphylococcus aureus (S. aureus including 200, 137 and 19 corresponding to MSSA, MRSA, and intermediate MRSA strains, respectively were isolated. Antibacterial susceptibility patterns of the isolates to 14 antibiotics were examined using Kirby-Bauer method. MICs of 15 antibiotics to 156 MRSA isolates were determined by E test method. Cross-resistances of MRSA isolates (137+19 to the other tested antibiotics were also determined. S.aureus with high frequencies were isolated from the blood, sputum and deep wound samples. All of 200 MSSA isolates were sensitive to oxacillin, vancomycin, tecoplanin, rifampin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid. A gradient of reduced susceptibility of MSSA to cephalexin, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin were evident. MRSA isolates were sensitive to vancomycin, tecoplanin, linezolid, quinupristin/dalfopristin, mupirocin and fusidic acid, while reduced susceptibility of them to rifampin, co-trimoxazole, clindamycin, cephalexin, tetracycline, ciprofloxacin, erythromycin and gentamicin were observed. MRSA isolates exhibited a high range of cross-resistance to the eight tested antibiotics. Overall, co-trimoxazole, ciprofloxacin, clindamycin, tetracycline, erythromycin and gentamicin showed low activity against MSSA and MRSA isolates which may indicate they are not suitable to be used in clinical practices. To preserve the effectiveness of antibiotics, rational prescription and concomitant application of preventive measures against the spread of MRSA are recommended.

Enzymuria in neonates receiving continuous intravenous infusion of gentamicin

DEFF Research Database (Denmark)

Colding, H; Brygge, K; Brendstrup, L

1992-01-01

with non-treatment periods in the same newborn infant (33 infants). The same tendency applied to AAP. Newborn infants receiving continuous intravenous infusion of gentamicin were not found to be at greater risk of nephrotoxicity than those receiving intermittent gentamicin treatment, using NAG and AAP...

Antimicrobials in small-scale urban pig farming in a lower middle-income country - arbitrary use and high resistance levels.

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Ström, G; Boqvist, S; Albihn, A; Fernström, L-L; Andersson Djurfeldt, A; Sokerya, S; Sothyra, T; Magnusson, U

2018-01-01

Administration of antimicrobials to food-producing animals is regarded as a major contributor to the overall emergence of resistance in bacteria worldwide. However, few data are available on global antimicrobial use and resistance (AMR) in livestock, especially from low- and middle-income countries. We conducted a structured survey of 91 small-scale pig farms in the urban and peri-urban areas of Phnom Penh, Cambodia, to assess the farmers' knowledge, attitudes and practices related to antimicrobial use in their pig production. Commensal Escherichia coli was isolated from three healthy pigs from each farm ( n  = 261) and susceptibility testing was performed against 14 antimicrobials, using broth microdilution. Univariable logistic regression and generalized linear mixed models were used to investigate potential associations between farm characteristics, management factors and resistance to different types of antimicrobials. We found a widespread and arbitrary use of antimicrobials, often based on the farmer's own judgment. Around 66% of the farmers reported frequently self-adjusting treatment duration and dosage, and 45% had not heard about the term 'antimicrobial resistance'. The antimicrobials most commonly mentioned or kept by the farmers were amoxicillin, tylosin, gentamicin and colistin. Around 37% used a feed concentrate that contained antimicrobials, while antimicrobials for humans were used as a last-line treatment by 10% of the farmers. Commensal E. coli exhibited high prevalence of resistance to several antimicrobials considered to be of critical importance for human medicine, including ampicillin, ciprofloxacin and colistin, and multidrug-resistance was found in 79% of the samples. Higher prevalence of resistance was observed on farms that administered prophylactic antimicrobials and on farms that treated the entire group or herd in the event of disease. The widespread and arbitrary use of antimicrobials in pig farming in Cambodia is highly worrisome

Protective Effect of Cinnamomum tamala Extract on Gentamicin ...

African Journals Online (AJOL)

Results: Gentamicin-treated animals showed significant renal damage as indicated by rise in blood ... mg/dl), urinary proteins (3.86 ± 0.32 mg/dl) and decrease in creatinine ... been used in folk medicine as brain tonic and ... also been reported with high phenolic contents ... maintained on the same diet and 12 h light/dark.

Enterococci Isolated from Japanese Quails Exposed to Microgravity Conditions and Stability of their Properties

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Andrea Lauková

2009-01-01

Full Text Available Enterococci isolated from the crop and caecum of Japanese quails exposed to 7 day conditions of microgravity were re-vitalized after their dry-freezing long storage. Originally, the strains were isolated from Japanese quails after their landing from flight onboard the orbital station Mir during the experiment in August 1990. Because taxonomy as well as the studies concerning the bacteriocins, especially those produced by enterococci, have been continually developed for years, the aim of this study was to confirm species identification, stability of the properties of enterococci as well as to test new properties after their long storage. Genotyping allotted the strains to the species E. faecium. Lactic acid production was detected in similar amounts in the strains before and after their long-storage in dry-frozen form. The strains were vancomycinsensitive and kanamycin-resistant before as well as after their long-time storage. Variability in sensitivity to different antibiotics was found among the strains tested even before and after longtime storage. Each of the strains possessed at least one structural enterocin gene. The structural genes for enterocin A, P, B, L50B were detected in E. faecium EP7. E. faecium EP2, EEP4 have the genes for ent A, B, L50B. The gene for ent P was detected only in the strain EP7. The most often detected was ent A gene followed by ent genes B, L50B. All strains inhibited growth of at least 4 out of 15 indicators. The stability of the enterococcal properties determined before as well as after their dry-freezing was not influenced during their long-term storage; moreover, new properties were determined.

Tritium Labeled Gentamicin C: II.- Bioradiactive Degradation Products of Gentamicin by Catalytic H2O-3H Exchange Reaction; Getamicina C Tritiada: II.- Productos de Degradacion Radiactivos y Bioactivos en el Intercambio Catalitico con H2O-3H

Energy Technology Data Exchange (ETDEWEB)

Suarez, C.; Diaz, A.; Paz, D.; Jimeno, M. L.

1992-07-01

The main bio radioactive degradation products from catalytic hydrogen exchange of gentamicin C, (C1 + C2 + Cla) in basic form, are generated by N-demethylation in 3{sup -}N and 6-N positions. Their structures were confirmed by 1HNMR and 13CNMR. These derivatives were fractionated by chromatography on silica gel. Antibacterial activities were similar to those of the parent antibiotics. Tritium exchange, under vacuum or nitrogen, is highly increased (4:1) when gentamicin are in basic form. In contrast with gentamicin sulfate, hydrolytic sub products as gramine, genta mines, garosamine and purpurosamines are practically absent. To properly optimize the exchange process, the composition of the gentamicin C complex must be taken into account. The exchange decreases in the order C2 > C1> Cla. Because of 6'-N-demethyl gentamicin C1 is C2, the radiochemical yield of C2 appears enhanced in the H2O-3H exchange of a mixture of them. Radioactivity distribution among the components and subunits of these three gentamicin were studied by strong and mild hydrolysis, and by methanolysis. (Author) 18 refs.

Gentamicin Nephrotoxicity in Subclinical Renal Disease.

Science.gov (United States)

Frazier, Donita L.

The purpose of the present study was to examine the pharmacokinetic disposition of gentamicin and to define the mechanisms which predispose to nephrotoxicity in subclinical renal disease. Subtotally nephrectomized beagle dogs were used as a model for human beings with compromised renal function secondary to a reduced number of functional nephrons. Using ultrastructural morphometry, light microscopy and clinical chemistry data, the model was defined and the nephrotoxic responses of intact dogs administered recommended doses of drug were compared to the response of subtotally nephrectomized dogs administered reduced doses based on each animal's clearance of drug. Lysosomal and mitochondrial morphometric changes suggested mechanisms for increased sensitivity. To determine if increased sensitivity in this model was dependent on altered serum concentrations, variable rate infusions based on individual pharmacokinetic disposition of drug were administered using computer-driven infusion pumps. Identical serum concentration-time profiles were achieved in normal dogs and subtotally nephrectomized dogs, however, toxicity was significantly greater in nephrectomized dogs. The difference in the nephrotoxic response was characterized by administering supratherapeutic doses of drug to dogs. Nephrectomized dogs given a recommended dose of gentamicin became oliguric during the second week of treatment and increasingly uremic after withdrawal of drug. In contrast, intact dogs administered 2 times the recommended dose of gentamicin become only slightly polyuric during week 4 of treatment. The need to individualize dosage regimens based on drug clearance and not serum creatinine nor creatinine clearance alone was substantiated by describing the pharmacokinetic disposition of gentamicin in spontaneously occurring disease states. Four individualized dosage regimens with differing predicted efficacy were then administered to nephrectomized dogs to determine their relative nephrotoxic

Transfer of antibiotic resistance from Enterococcus faecium of fermented meat origin to Listeria monocytogenes and Listeria innocua.

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Jahan, M; Holley, R A

2016-04-01

Listeria monocytogenes is an important foodborne pathogen that can cause infection in children, pregnant women, the immunocompromised and the elderly. Antibiotic resistance in this species would represent a significant public health problem since the organism has a high fatality/case ratio and resistance may contribute to failure of therapeutic treatment. This study was designed to explore whether the in vitro transferability of antibiotic resistance from enterococci to Listeria spp. could occur. It was found that 2/8 Listeria strains were able to acquire tetracycline resistance from Enterococcus faecium. Listeria monocytogenes GLM-2 acquired the resistance determinant tet(M) and additional streptomycin resistance through in vitro mating with Ent. faecium S27 isolated from commercial fermented dry sausage. Similarly, Listeria innocua became more resistant to tetracycline, but the genetic basis for this change was not confirmed. It has been suggested that enterococci may transfer antibiotic resistance genes via transposons to Listeria spp., and this may explain, in part, the origin of their antibiotic resistance. Thus, the presence of enterococci in food should not be ignored since they may actively contribute to enhanced antibiotic resistance of L. monocytogenes and other pathogens. Acquisition of antibiotic resistance by pathogenic bacteria in the absence of antibiotic pressure represents an unquantified threat to human health. In the present work resistance to tetracycline and streptomycin were transferred by nonplasmid-based conjugation from Enterococcus faecium isolated from fermented sausage to Listeria monocytogenes and Listeria innocua. Thus, natural transfer of antibiotic resistance to Listeria strains may occur in the future which reinforces the concern about the safety of enterococcal strains present in foods. © 2016 The Society for Applied Microbiology.

Evaluation of prevalence of low and high level mupirocin resistance in methicillin resistant staphylococcus aureus isolates at a tertiary care hospital

International Nuclear Information System (INIS)

Nizamuddin, S.; Irfan, S.; Zafar, A.

2011-01-01

To evaluate the trend of mupirocin resistance in MRSA, isolated at the Clinical Microbiology Laboratory of a tertiary care hospital. Methods: A total of 200 MRSA strains recovered over a 2 year period from various body sites were tested using the 5 and 200 mu g discs of mupirocin to detect its resistance. Results: High level and low level mupirocin resistance were detected in zero and 1 % of MRSA strains, respectively. Resistance to other non beta lactam antibiotics was also high. No MRSA strains were found to be resistant to vancomycin and tegicycline. Conclusion: Mupirocin resistance was found to be very low among local clinical isolates of MRSA. Its judicious use to decolonize nasal carriers should be promoted among hospitalized patients to avoid further transmission and infections due to prevalent endemic MRSA strains in any health care setting. Concomitantly, regular surveillance and effective infection control initiatives are desirable to reduce the incidence of health care associated infections due to MRSA and also of mupirocin resistance. (author)

MICROMORPHOLOGICALCHARACTERISTICS OF THE LIVER AND BIOCHEMICAL ANALYSES IN THE BLOOD OF RATS TREATED BY GENTAMICIN AND VERAPAMIL

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Milan Stoiljkovic

2006-04-01

Full Text Available The use of antimicrobial drugs, especially gentamicin and calcium blocker verapamil, may cause transitional functional damage of the liver.The aim of this study is to explore micro-morphological changes in the liver and biochemical changes in the blood of rats treated with gentamicin and verapamil. The research included 20 rats divided in experimental and control group. The experimental group (10 rats was treated with gentamicin (100 mg/kg/BW/24h and verapamil (3 mg/kgBW/24 h for 8 days. The control group (10 rats received physiological solution (1 ml/kgBW/24 h at the same time. We analyzed micro-morphological changes in the liver and biochemical parameters in blood: transaminase, bilirubin and glucose.In the control group, there was a normal lobular liver structure. All hepatocytes had polygonal shape, pink cytoplasm and the location of nucleus was central or paracentral. Biochemical blood analysis showed normal level of transaminase (SGOT 29.5 +/- 7.4 iu/l; SGPT 31.7 +/- 6.9 iu/l, total bilirubin (3.1 +/- 0.9 mmol/l and glucose (4.9 +/- 0.9 mmol/l. In the experimental group of animals, hepatocytes of all three zones were equally damaged. In the cytoplasm, we found vacuolar degeneration, reduced condensation of chromatine in nucleus and light nucleoplasm. Hepatocytes of the periportal zone had acidofillic degeneration, picnotic and hiperchromatic nuclei. Biochemical blood analysis showed high level of transaminase (SGOT 46.4 +/- 4.7 iu/l; SGPT 50.8+/-6.1 iu/l, total bilirubin (12.8+/-1.7 mmol/l and glucose (9.3+/-1.8 mmol/l. There is a statistically significant difference in biochemical parameters between the two groups (p < 0,001. The results of our experimental study suggest that there is an obvious correlation between application of gentamicin and verapamil and these changes.

Effects of gentamicin on the recovery of renal function after unilateral hydronephrosis

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Seki, Nobumitsu [Ehime Univ., Shigenobu (Japan). School of Medicine

2002-06-01

Urinary tract infection is one of complications in hydronephrosis, and antibiotics such as gentamicin are indicated for the treatment. However, gentamicin is known to cause drug-induced nephropathy. Using a rat kidney model, we investigated the effects of gentamicin treatment on the functional recovery from unilateral hydronephrosis. Quantitative separate renal function study by means of Technetium-99m DMSA renoscintigraphy revealed that contralateral kidney was affected by the treatment right after the release of complete ureteral obstruction. Moreover, in the case of incomplete ureteral obstruction, bilateral kidneys were affected by the treatment. Morphological studies using in situ DNA3' -end labeling and immunohistochemical methods showed that regeneration in the bilateral kidney followed gentamicin treatment right after the release. These results suggest that we should take account of separate renal function failure after gentamicin administration in the perihydronephrotic periods. (author)

Evaluation of Petrifilm™ Select E. coli Count Plate medium to discriminate antimicrobial resistant Escherichia coli

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Jensen Lars

2008-09-01

Full Text Available Abstract Background Screening and enumeration of antimicrobial resistant Escherichia coli directly from samples is needed to identify emerging resistant clones and obtain quantitative data for risk assessment. Aim of this study was to evaluate the performance of 3M™ Petrifilm™ Select E. coli Count Plate (SEC plate supplemented with antimicrobials to discriminate antimicrobial-resistant and non-resistant E. coli. Method A range of E. coli isolates were tested by agar dilution method comparing the Minimal Inhibitory Concentration (MIC for eight antimicrobials obtained by Mueller-Hinton II agar, MacConkey agar and SEC plates. Kappa statistics was used to assess the levels of agreement when classifying strains as resistant, intermediate or susceptible. Results SEC plate showed that 74% of all strains agreed within ± 1 log2 dilution when comparing MICs with Mueller-Hinton II media. High agreement levels were found for gentamicin, ampicillin, chloramphenicol and cefotaxime, resulting in a kappa value of 0.9 and 100% agreement within ± 1 log2 dilution. Significant variances were observed for oxytetracycline and sulphamethoxazole. Further tests showed that the observed discrepancy in classification of susceptibility to oxytetracycline by the two media could be overcome when a plate-dependent breakpoint of 64 mg/L was used for SEC plates. For sulphamethoxazole, SEC plates provided unacceptably high MICs. Conclusion SEC plates showed good agreement with Mueller-Hinton II agar in MIC studies and can be used to screen and discriminate resistant E. coli for ampicillin, cephalothin, streptomycin, chloramphenicol, cefotaxime and gentamicin using CLSI standardized breakpoints, but not for sulphamethoxazole. SEC plates can also be used to discriminate oxytetracycline-resistant E. coli if a plate-dependent breakpoint value of 64 mg/L is used.

Gentamicin modified chitosan film with improved antibacterial property and cell biocompatibility.

Science.gov (United States)

Liu, Yang; Ji, Peihong; Lv, Huilin; Qin, Yong; Deng, Linhong

2017-05-01

Gentamicin modified chitosan film (CS-GT) was produced using a three-step procedure comprising: (i) the chitosan solution was air-dried to form a chitosan (CS) film, (ii) using citric acid to generate the amide and carboxyl groups on the surface of CS, (iii) the CS with surface carboxyl groups was modified by grafting of gentamicin. After modification, this CS-GT film has excellent hydrophilicity and biocompatibility. It is very evident that the gentamicin grafting treatment significantly improves the antibacterial properties of the CS film. Our preliminary results suggest that this novel gentamicin modified chitosan film, which can be prepared in large quantities and at low cost, should have potential application in biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Cost evaluation of therapeutic drug monitoring of gentamicin at a teaching hospital in Malaysia

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Ibrahim MI

2014-03-01

Full Text Available Background: Therapeutic drug monitoring (TDM makes use of serum drug concentrations as an adjunct to decision-making. Preliminary data in our hospital showed that approximately one-fifth of all drugs monitored by TDM service were gentamicin. Objective: In this study, we evaluated the costs associated with providing the service in patients with bronchopneumonia and treated with gentamicin. Methods: We retrospectively collected data from medical records of patients admitted to the Hospital Universiti Sains Malaysia over a 5-year period. These patients were diagnosed with bronchopneumonia and were on gentamicin as part of their treatment. Five hospitalisation costs were calculated; (i cost of laboratory and clinical investigations, (ii cost associated with each gentamicin dose, (iii fixed and operating costs of TDM service, (iv cost of providing medical care, and (v cost of hospital stay during gentamicin treatment. Results: There were 1920 patients admitted with bronchopneumonia of which 67 (3.5% had TDM service for gentamicin. Seventy-three percent (49/67 patients were eligible for final analysis. The duration of gentamicin therapy ranged from 3 to 15 days. The cost of providing one gentamicin assay was MYR25, and the average cost of TDM service for each patient was MYR104. The average total hospitalisation cost during gentamicin treatment for each patient was MYR442 (1EUR approx. MYR4.02. Conclusion: Based on the hospital perspective, in patients with bronchopneumonia and treated with gentamicin, the provision of TDM service contributes to less than 25% of the total cost of hospitalization.

Pentoxifylline Ameliorates Glomerular Basement Membrane Ultrastructural Changes Caused by Gentamicin Administration in Rats

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Nenad Stojiljković

2009-08-01

Full Text Available Gentamicin is commonly used for the treatment of severe gram negative bacterial infections but inevi-tably cause renal failure during prolonged use. The aim of our study was to emphasize protective effects of pentoxifylline on glomerular basement membrane (GBM alterations induced by gentamicin in rats. Experiments were done on 40 male Wistar rats divided in three experimental groups. GM-group was treated daily with gentamicin in dose of 100 mg/kg during 8 days. PTX-group was treated daily with pentoxifylline in dose of 45 mg/kg and the same dose of gentamicin as in GM-group during 8 days. The control group received 1 ml/day saline intraperitoneally. Morphometric parameter measured during the analysis was glomerular basement membrane thickness. In GM-group of animals glomeruli were en-larged and GMB was diffusely and unequally thickened with neutrophil cells infiltration. In proximal tu-bules epithelial cells, vacuolization of cytoplasm with coagulation-type necrosis were observed. In PTX-group of animals glomeruli were somewhat enlarged and GBM was thickened only in some segments. Coagulation-type necrosis was not found. Blood urea and serum creatinine concentration in GM-group were significantly elevated in comparison with PTX-group while potassium level was decreased. Our results suggest that PTX has protective effects on GBM and proximal tubules in GM-treated rats.

Blood culture contamination with Enterococci and skin organisms: implications for surveillance definitions of primary bloodstream infections.

Science.gov (United States)

Freeman, Joshua T; Chen, Luke Francis; Sexton, Daniel J; Anderson, Deverick J

2011-06-01

Enterococci are a common cause of bacteremia but are also common contaminants. In our institution, approximately 17% of positive blood cultures with enterococci are mixed with skin organisms. Such isolates are probable contaminants. The specificity of the current definition of primary bloodstream infection could be increased by excluding enterococci mixed with skin organisms. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

The Effects of Zataria Multiflora Hydroalcoholic Extract on Gentamicin Induced Nephrotoxicity in Rats

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Saeed Hajihashemi

2015-07-01

Full Text Available Abstract Background: Gentamicin is an aminoglycoside antibiotic that broadly is used to treat gram negative bacteria infections, although it has side effects such as nephrotoxicity. According to antioxidant, anti-inflammatory and vasodilatory properties of Zataria Multiflora, the effects of co-treatment with zataria Multiflora and hydroalcholic extract on gentamicin induced nephrotoxicitj were investigated. Materials and Methods: In this study, male rats of Vistar race were divided into 4 groups: 1.control group, 2. co-treatment with gentamicin and vehicle group, 3. co-treatment with gentamicin and zataria Multifiora extract group, 4. co-treatment with zataria Multiflora extract and normal saline solution group. Zataria Multiflora hydroalcoholic extract was added to drinking water as 800 PPm concentration. They, systolic blood pressure and renal blood flow (RBF were measured. Also, the amounts of urea, creatinine, sodium, potassium and osmolarity were measured in plasma and urine samples Results: In co-treatment group with zataria Multiflora extract, the amounts of urea, creatinine, absolute sodium excretion and relative sodium and potassium excretion and malondialdehyde (MDA that have been inceased in treatment with gentamicin, significantly were reduced. Creatinine clearance, urine osmolarity, RBF and FRAP that was decreased in gentamicin group in compare to control group, significantly increased. Conclusion: Co-treatment prevents nephrotoxicity induced by gentamicin and attenuates oxidative-stress associated renal injury by reducing oxygen free radicals and lipid peroxidation, So it can be effective to cure rats receiving gentamicin.

Determination of antibiotic resistance of lactic acid bacteria isolated from traditional Turkish fermented dairy products.

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Erginkaya, Z; Turhan, E U; Tatlı, D

2018-01-01

In this study, the antibiotic resistance (AR) of lactic acid bacteria (LAB) isolated from traditional Turkish fermented dairy products was investigated. Yogurt, white cheese, tulum cheese, cokelek, camız cream and kefir as dairy products were collected from various supermarkets. Lactic acid bacteria such as Lactobacillus spp., Streptococcus spp., Bifidobacterium spp., and Enterecoccus spp. were isolated from these dairy products. Lactobacillus spp. were resistant to vancomycin (58%), erythromycin (10.8%), tetracycline (4.3%), gentamicin (28%), and ciprofloxacin (26%). Streptococcus spp. were resistant to vancomycin (40%), erythromycin (10%), chloramphenicol (10%), gentamicin (20%), and ciprofloxacin (30%). Bifidobacterium spp. were resistant to vancomycin (60%), E 15 (6.6%), gentamicin (20%), and ciprofloxacin (33%). Enterococcus spp. were resistant to vancomycin (100%), erythromycin (100%), rifampin (100%), and ciprofloxacin (100%). As a result, LAB islated from dairy products in this study showed mostly resistance to vancomycin.

Effect of nephrotoxic treatment with gentamicin on rats chronically exposed to uranium

International Nuclear Information System (INIS)

Rouas, Caroline; Stefani, Johanna; Grison, Stephane; Grandcolas, Line; Baudelin, Cedric; Dublineau, Isabelle; Pallardy, Marc; Gueguen, Yann

2011-01-01

Uranium is a radioactive heavy metal with a predominantly chemical toxicity, affecting especially the kidneys and more particularly the proximal tubular structure. Until now, few experimental studies have examined the effect of chronic low-dose exposure to uranium on kidney integrity: these mainly analyse standard markers such as creatinine and urea, and none has studied the effect of additional co-exposure to a nephrotoxic agent on rats chronically exposed to uranium. The aim of the present study is to examine the potential cumulative effect of treating uranium-exposed rats with a nephrotoxic drug. Neither physiological indicators (diuresis and creatinine clearance) nor standard plasma and urine markers (creatinine, urea and total protein) levels were deteriorated when uranium exposure was combined with gentamicin-induced nephrotoxicity. A histological study confirmed the preferential impact of gentamicin on the tubular structure and showed that uranium did not aggravate the histopathological renal lesions. Finally, the use of novel markers of kidney toxicity, such as KIM-1, osteopontin and kallikrein, provides new knowledge about the nephrotoxicity threshold of gentamicin, and allows us to conclude that under our experimental conditions, low dose uranium exposure did not induce signs of nephrotoxicity or enhance renal sensitivity to another nephrotoxicant.

Zinc and copper in animal feed – development of resistance and co-resistance to antimicrobial agents in bacteria of animal origin

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Siamak Yazdankhah

2014-09-01

Full Text Available Farmed animals such as pig and poultry receive additional Zn and Cu in their diets due to supplementing elements in compound feed as well as medical remedies. Enteral bacteria in farmed animals are shown to develop resistance to trace elements such as Zn and Cu. Resistance to Zn is often linked with resistance to methicillin in staphylococci, and Zn supplementation to animal feed may increase the proportion of multiresistant E. coli in the gut. Resistance to Cu in bacteria, in particular enterococci, is often associated with resistance to antimicrobial drugs like macrolides and glycopeptides (e.g. vancomycin. Such resistant bacteria may be transferred from the food-producing animals to humans (farmers, veterinarians, and consumers. Data on dose-response relation for Zn/Cu exposure and resistance are lacking; however, it seems more likely that a resistance-driven effect occurs at high trace element exposure than at more basal exposure levels. There is also lack of data which could demonstrate whether Zn/Cu-resistant bacteria may acquire antibiotic resistance genes/become antibiotics resistant, or if antibiotics-resistant bacteria are more capable to become Zn/Cu resistant than antibiotics-susceptible bacteria. Further research is needed to elucidate the link between Zn/Cu and antibiotic resistance in bacteria.

Activity of vancomycin, linezolid, and daptomycin against staphylococci and enterococci isolated in 5 Greek hospitals during a 5-year period (2008-2012).

Science.gov (United States)

Papadimitriou-Olivgeris, Matthaios; Kolonitsiou, Fevronia; Zerva, Loukia; Lebessi, Evangelia; Koutsia, Chryssa; Drougka, Eleanna; Sarrou, Styliani; Giormezis, Nikolaos; Vourli, Sofia; Doudoulakakis, Anastassios; Konsolakis, Christos; Marangos, Markos; Anastassiou, Evangelos D; Petinaki, Efthimia; Spiliopoulou, Iris

2015-12-01

The tendency of vancomycin, linezolid, and daptomycin MICs was investigated among 6920 staphylococci and enterococci during a 5-year period. Antimicrobial consumption was determined. Decrease of vancomycin MIC was detected associated with reduction in consumption. Linezolid and daptomycin remained active. An upward trend of linezolid MIC for methicillin-resistant staphylococci was observed. Copyright © 2015 Elsevier Inc. All rights reserved.

Fate and transport of veterinary antibiotics, antibiotic-resistant bacteria, and antibiotic resistance gene from fields receiving poultry manure during storm events

Science.gov (United States)

Antimicrobials are used in production agriculture to treat disease and promote animal growth, but the presence of antibiotics in the environment raises concern about widespread antibiotic resistance. This study documents the occurrence and transport of tylosin, tetracycline, enterococci resistant to...

Antibiotic resistance in animals.

Science.gov (United States)

Barton, Mary D; Pratt, Rachael; Hart, Wendy S

2003-01-01

There is currently no systematic surveillance or monitoring of antibiotic resistance in Australian animals. Registration of antibiotics for use in animals is tightly controlled and has been very conservative. Fluoroquinolones have not been registered for use in food producing animals and other products have been removed from the market because of human health concerns. In the late 1970s, the Animal Health Committee coordinated a survey of resistance in Salmonella and Escherichia coli isolates from cattle, pigs and poultry and in bovine Staphylococcus aureus. Some additional information is available from published case reports. In samples collected prior to the withdrawal of avoparcin from the market, no vancomycin resistant Enterococcus faecium or Enterococcus faecalis were detected in samples collected from pigs, whereas some vanA enterococci, including E. faecium and E. faecalis, were found in chickens. No vanB enterococci were detected in either species. Virginiamycin resistance was common in both pig and poultry isolates. Multiple resistance was common in E. coli and salmonellae isolates. No fluoroquinolone resistance was found in salmonellae, E. coli or Campylobacter. Beta-lactamase production is common in isolates from bovine mastitis, but no methicillin resistance has been detected. However, methicillin resistance has been reported in canine isolates of Staphylococcus intermedius and extended spectrum beta-lactamase producing E. coli has been found in dogs.

Molecular Basis of Resistance to Selected Antimicrobial Agents in the Emerging Zoonotic Pathogen Streptococcus suis.

Science.gov (United States)

Gurung, Mamata; Tamang, Migma Dorji; Moon, Dong Chan; Kim, Su-Ran; Jeong, Jin-Ha; Jang, Geum-Chan; Jung, Suk-Chan; Park, Yong-Ho; Lim, Suk-Kyung

2015-07-01

Characterization of 227 Streptococcus suis strains isolated from pigs during 2010 to 2013 showed high levels of resistance to clindamycin (95.6%), tilmicosin (94.7%), tylosin (93.8%), oxytetracycline (89.4%), chlortetracycline (86.8%), tiamulin (72.7%), neomycin (70.0%), enrofloxacin (56.4%), penicillin (56.4%), ceftiofur (55.9%), and gentamicin (55.1%). Resistance to tetracyclines, macrolides, aminoglycosides, and fluoroquinolone was attributed to the tet gene, erm(B), erm(C), mph(C), and mef(A) and/or mef(E) genes, aph(3')-IIIa and aac(6')-Ie-aph(2″)-Ia genes, and single point mutations in the quinolone resistance-determining region of ParC and GyrA, respectively. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Marine echinoderms as reservoirs of antimicrobial resistant bacteria

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Catarina Marinho

2014-06-01

Full Text Available Echinoderms are benthic animals that play an important ecological role in marine communities occupying diverse trophic levels in the marine food chains. The majority of echinoderms feed on small particles of edible matter, although they can eat many kinds of food (Clark, 1968. Although, some echinoderms species has been facing an emerging demand for human consumption, particularly in Asian and Mediterranean cuisine, where these animals can be eaten raw (Kelly, 2005; Micael et al., 2009. Echinoderms own an innate immune mechanism that allows them to defend themselves from high concentrations of bacteria, viruses and fungus they are often exposed, on marine sediment (Janeway and Medzhitov, 1998, Cooper, 2003. The most frequent genera of gut bacteria in echinoderms are Vibrio, Pseudomonas, Flavobacterium, and Aeromonas; nevertheless Enterococcus spp. and Escherichia coli are also present (Harris, 1993; Marinho et al., 2013. Moreover, fecal resistant bacteria found in the aquatic environment might represent an index of marine pollution (Foti et al., 2009, Kummerer, 2009. Several studies had been lead in order to identify environmental reservoirs for antibiotic-resistant bacteria in populations of fish, echinoderms and marine mammals, and they all support the thesis that these animals may serve as reservoirs since they had acquired resistant microbial species (Johnson et al., 1998, Marinho et al., 2013, Miranda and Zemelman, 2001. However, to our knowledge, there are only available in bibliography one study of antimicrobial resistant bacteria isolated from marine echinoderms (Marinho et al., 2013, which stats that their provenience in this environment is still unclear. Antimicrobial resistance outcomes from the intensive use of antimicrobial drugs in human activities associated with various mechanisms for bacteria genetic transfer (Barbosa and Levy, 2000, Coque et al., 2008. Antibiotic-resistant bacteria enter into water environments where they are

Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials,

Directory of Open Access Journals (Sweden)

Erika Celis-Aguilar

Full Text Available Abstract Introduction: Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. Objective: To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Methods: Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8 mL of gentamicin intratympanic application at a 30 mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Results: Ten patients were included; nine patients with Meniere's disease and one patient with (late onset delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30 dB. Conclusions: Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials.

Characterisation, in vitro release study, and antibacterial activity of montmorillonite-gentamicin complex material

International Nuclear Information System (INIS)

Rapacz-Kmita, A.; Bućko, M.M.; Stodolak-Zych, E.; Mikołajczyk, M.; Dudek, P.; nd Department of Surgery, Kopernika 21, 31-501 Krakow (Poland))" data-affiliation=" (Jagiellonian University, Medical College, 2nd Department of Surgery, Kopernika 21, 31-501 Krakow (Poland))" >Trybus, M.

2017-01-01

The present paper concerns the potential use of montmorillonite as a drug carrier and focusses on the intercalation of the studied clay with gentamicin (an aminoglycoside antibiotic) at various temperatures (20, 50 and 80 °C). The experiments were performed to identify the temperature required for the optimum intercalation of gentamicin into the interlayer of montmorillonite. The structural and microstructural properties of gentamicin and the potential for introducing it between smectite clay layers were investigated by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopic techniques, and SEM with EDS analysis. Additionally, the in vitro drug release behaviour of the montmorillonite-gentamicin complex and its antibacterial activity against Escherichia coli (E. coli) bacteria was investigated. Based on these studies, the impact of temperature on the intercalation of the drug between layers of smectite was evaluated. It was found that an intercalation temperature of 50 °C resulted in the highest shift in the position of principle peak d (001) as measured by XRD, suggesting, that the greatest amount of gentamicin had been introduced into the interlayer space of montmorillonite at this temperature. Subsequently, the montmorillonite-gentamicin complex material obtained at 50 °C revealed the greatest capacity for killing E. coli bacteria during an in vitro test. - Highlights: • A novel montmorillonite-gentamicin hybrid materials was prepared as potential drug carrier. • Optimal conditions for the intercalation of gentamicin into the interlayer space of montmorillonite were tested. • The MMT-G complex material obtained at 50 °C revealed the greatest capacity for killing E. coli during the inhibitory zone test. • Modulating drug delivery was monitored and confirmed in in vitro drug release study.

Characterisation, in vitro release study, and antibacterial activity of montmorillonite-gentamicin complex material

Energy Technology Data Exchange (ETDEWEB)

Rapacz-Kmita, A., E-mail: kmita@agh.edu.pl [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Mickiewicza 30, 30-059 Krakow (Poland); Bućko, M.M.; Stodolak-Zych, E. [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Mickiewicza 30, 30-059 Krakow (Poland); Mikołajczyk, M. [The University Hospital in Krakow, Division of Microbiology, Kopernika 19, 31-501 Krakow (Poland); Dudek, P. [AGH University of Science and Technology, Faculty of Mechanical Engineering and Robotics, Mickiewicza 30, 30-059 Krakow (Poland); Trybus, M. [Jagiellonian University, Medical College, 2" n" d Department of Surgery, Kopernika 21, 31-501 Krakow (Poland)

2017-01-01

The present paper concerns the potential use of montmorillonite as a drug carrier and focusses on the intercalation of the studied clay with gentamicin (an aminoglycoside antibiotic) at various temperatures (20, 50 and 80 °C). The experiments were performed to identify the temperature required for the optimum intercalation of gentamicin into the interlayer of montmorillonite. The structural and microstructural properties of gentamicin and the potential for introducing it between smectite clay layers were investigated by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopic techniques, and SEM with EDS analysis. Additionally, the in vitro drug release behaviour of the montmorillonite-gentamicin complex and its antibacterial activity against Escherichia coli (E. coli) bacteria was investigated. Based on these studies, the impact of temperature on the intercalation of the drug between layers of smectite was evaluated. It was found that an intercalation temperature of 50 °C resulted in the highest shift in the position of principle peak d{sub (001)} as measured by XRD, suggesting, that the greatest amount of gentamicin had been introduced into the interlayer space of montmorillonite at this temperature. Subsequently, the montmorillonite-gentamicin complex material obtained at 50 °C revealed the greatest capacity for killing E. coli bacteria during an in vitro test. - Highlights: • A novel montmorillonite-gentamicin hybrid materials was prepared as potential drug carrier. • Optimal conditions for the intercalation of gentamicin into the interlayer space of montmorillonite were tested. • The MMT-G complex material obtained at 50 °C revealed the greatest capacity for killing E. coli during the inhibitory zone test. • Modulating drug delivery was monitored and confirmed in in vitro drug release study.

Use of antimicrobial growth promoters in food animals and Enterococcus faecium resistance to therapeutic antimicrobial drugs in Europe

DEFF Research Database (Denmark)

Wegener, Henrik Caspar; Aarestrup, Frank Møller; Jensen, Lars Bogø

1999-01-01

on the Tn1546 transposon. Furthermore, glycopeptide-resistant strains, as well as resistance determinants, can be transmitted from animals to humans. Two antimicrobial classes expected to provide the future therapeutic options for treatment of infections with vancomycin-resistant enterococci have analogues......Supplementing animal feed with antimicrobial agents to enhance growth has been common practice for more than 30 years and is estimated to constitute more than half the total antimicrobial use worldwide. The potential public health consequences of this use have been debated; however, until recently......, clear evidence of a health risk was not available. Accumulating evidence now indicates that the use of the glycopeptide avoparcin as a growth promoter has created in food animals a major reservoir of Enterococcus faecium, which contains the high level glycopeptide resistance determinant vanA, located...

Gentamicin-Loaded Thermosetting Hydrogel and Moldable Composite Scaffold: Formulation Study and Biologic Evaluation.

Science.gov (United States)

Dorati, Rossella; De Trizio, Antonella; Genta, Ida; Merelli, Alessia; Modena, Tiziana; Conti, Bice

2017-06-01

The aim was to design biodegradable drug delivery systems for gentamicin local delivery, meanwhile acting as scaffold for bone regeneration. Gentamicin-loaded thermosetting composite hydrogels were prepared combining chitosan with bovine bone substitutes (Orthoss® granules), beta-glycerophosphate as cross-linker, and lyophilized to obtain moldable composite scaffolds (moldable composite scaffold loaded with gentamicin [mCSG]). Diverse techniques for gentamicin loading into mCS were investigated by drug incorporation during hydrogel preparation or drug absorption on preformed mCS. Rheologic hydrogel characterization was performed. mCSGs were characterized for porosity, stability (water retention, water uptake), gentamicin release, cell seeding and proliferation, and antimicrobial effect on Escherichia coli ATCC 10356. Results show suitable gentamicin loadings were 4 mg in 1 mL thermosetting composite hydrogel starting solution, irreversible hydrogel thermosetting behavior, and cosolute effect of gentamicin on sol-gel transition. Positive results in terms of porosity (80%-86%), scaffold water uptake, and retention capability were obtained. Antibiotic in vitro release was completed in 4 h. Good cell seeding results were observed for mCSG1-5; mCSG3 and mCSG5 resulted the best as cell proliferation results. mCSG exerted bactericidal effect for 24 h, with superimposition of chitosan bacteriostatic effect in the first 4 h. The results lead to consider the drug delivery for reducing infection risk during bone open surgeries. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

A decade-long commitment to antimicrobial resistance surveillance in Portugal

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Catarina Moreira Marinho

2016-10-01

Full Text Available Antimicrobial resistance (AMR is a worldwide problem with serious health and economic repercussions. Since the 1940s, underuse, overuse, and misuse of antibiotics have had a significant environmental downside. Large amounts of antibiotics not fully metabolized after use in human and veterinary medicine, and other applications, are annually released into the environment. The result has been the development and dissemination of antibiotic-resistant bacteria due to many years of selective pressure. Surveillance of AMR provides important information that helps in monitoring and understanding how resistance mechanisms develop and disseminate within different environments. Surveillance data is needed to inform clinical therapy decisions, to guide policy proposals, and to assess the impact of action plans to fight AMR. The Functional Genomics and Proteomics Unit, based at the University of Trás-os-Montes and Alto Douro (UTAD in Vila Real, Portugal, has recently completed 10 years of research surveying AMR in bacteria, mainly commensal indicator bacteria such as enterococci and Escherichia coli from the microbiota of different animals. Samples from more than 75 different sources have been accessed, from humans to food-producing animals, pets, and wild animals. The typical microbiological workflow involved phenotypic studies followed by molecular approaches. Throughout the decade, 4,017 samples were collected and over 5,000 bacterial isolates obtained. High levels of AMR to several antimicrobial classes have been reported, including to β-lactams, glycopeptides, tetracyclines, aminoglycosides, sulphonamides and quinolones. Multi-resistant strains, some relevant to human and veterinary medicine like extended-spectrum β-lactamase-producing E. coli and vancomycin-resistant enterococci, have been repeatedly isolated even in non-synanthropic animal species. Of particular relevance are reports of AMR bacteria in wildlife from natural reserves and endangered

Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae)

OpenAIRE

Rubião, Cynthia Annes; Franco, Robson Maia; Mesquita, Eliana de Fátima Marques de; Miguel, Marco Antonio Lemos; Cabral, Claudius Couto; Fonseca, Ana Beatriz Monteiro

2017-01-01

ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN) of Total Coliforms (TC), Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several ...

Antibacterial Efficacy of a New Gentamicin-Coating for Cementless Prostheses Compared to Gentamicin-Loaded Bone Cement

NARCIS (Netherlands)

Neut, Danielle; Dijkstra, Rene J. B.; Thompson, Jonathan I.; van der Mei, Henny C.; Busscher, Henk J.

Cementless prostheses are increasingly popular but require alternative prophylactic measures than the use of antibiotic-loaded bone cements. Here, we determine the 24-h growth inhibition of gentamicin-releasing coatings from grit-blasted and porous-coated titanium alloys, and compare their

Using Six Sigma to improve once daily gentamicin dosing and therapeutic drug monitoring performance.

LENUS (Irish Health Repository)

Egan, Sean

2012-08-07

BACKGROUND: Safe, effective therapy with the antimicrobial gentamicin requires good practice in dose selection and monitoring of serum levels. Suboptimal therapy occurs with breakdown in the process of drug dosing, serum blood sampling, laboratory processing and level interpretation. Unintentional underdosing may result. This improvement effort aimed to optimise this process in an academic teaching hospital using Six Sigma process improvement methodology. METHODS: A multidisciplinary project team was formed. Process measures considered critical to quality were defined, and baseline practice was examined through process mapping and audit. Root cause analysis informed improvement measures. These included a new dosing and monitoring schedule, and standardised assay sampling and drug administration timing which maximised local capabilities. Three iterations of the improvement cycle were conducted over a 24-month period. RESULTS: The attainment of serum level sampling in the required time window improved by 85% (p≤0.0001). A 66% improvement in accuracy of dosing was observed (p≤0.0001). Unnecessary dose omission while awaiting level results and inadvertent disruption to therapy due to dosing and monitoring process breakdown were eliminated. Average daily dose administered increased from 3.39 mg\\/kg to 4.78 mg\\/kg\\/day. CONCLUSIONS: Using Six Sigma methodology enhanced gentamicin usage process performance. Local process related factors may adversely affect adherence to practice guidelines for gentamicin, a drug which is complex to use. It is vital to adapt dosing guidance and monitoring requirements so that they are capable of being implemented in the clinical environment as a matter of routine. Improvement may be achieved through a structured localised approach with multidisciplinary stakeholder involvement.

Effect of nephrotoxic treatment with gentamicin on rats chronically exposed to uranium.

Science.gov (United States)

Rouas, Caroline; Stefani, Johanna; Grison, Stéphane; Grandcolas, Line; Baudelin, Cédric; Dublineau, Isabelle; Pallardy, Marc; Gueguen, Yann

2011-01-11

Uranium is a radioactive heavy metal with a predominantly chemical toxicity, affecting especially the kidneys and more particularly the proximal tubular structure. Until now, few experimental studies have examined the effect of chronic low-dose exposure to uranium on kidney integrity: these mainly analyse standard markers such as creatinine and urea, and none has studied the effect of additional co-exposure to a nephrotoxic agent on rats chronically exposed to uranium. The aim of the present study is to examine the potential cumulative effect of treating uranium-exposed rats with a nephrotoxic drug. Neither physiological indicators (diuresis and creatinine clearance) nor standard plasma and urine markers (creatinine, urea and total protein) levels were deteriorated when uranium exposure was combined with gentamicin-induced nephrotoxicity. A histological study confirmed the preferential impact of gentamicin on the tubular structure and showed that uranium did not aggravate the histopathological renal lesions. Finally, the use of novel markers of kidney toxicity, such as KIM-1, osteopontin and kallikrein, provides new knowledge about the nephrotoxicity threshold of gentamicin, and allows us to conclude that under our experimental conditions, low dose uranium exposure did not induce signs of nephrotoxicity or enhance renal sensitivity to another nephrotoxicant. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

In vitro gentamicin release from commercially available calcium-phosphate bone substitutes influence of carrier type on duration of the release profile

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Bronckers Antonius LJJ

2006-02-01

Full Text Available Abstract Background Polymethyl-methacrylate (PMMA beads releasing antibiotics are used extensively to treat osteomyelitis, but require surgical removal afterwards because they do not degrade. Methods As an alternative option, this report compares the in vitro gentamicin release profile from clinically used, biodegradable carrier-materials: six injectable cements and six granule-types. Cement cylinders and coated granules containing 3% gentamicin were submerged in dH2O and placed in a 48-sample parallel drug-release system. At regular intervals (30, 90, 180 min. and then every 24 h, for 21 days, the release fluid was exchanged and the gentamicin concentration was measured. The activity of released gentamicin was tested on Staphylococcus aureus. Results All combinations showed initial burst-release of active gentamicin, two cements had continuous-release (17 days. The relative release of all cements (36–85% and granules (30–62% was higher than previously reported for injectable PMMA-cements (up to 17% and comparable to other biodegradable carriers. From the cements residual gentamicin could be extracted, whereas the granules released all gentamicin that had adhered to the surface. Conclusion The high release achieved shows great promise for clinical application of these biodegradable drug-carriers. Using the appropriate combination, the required release profile (burst or sustained may be achieved.

77 FR 3598 - Ophthalmic and Topical Dosage Form New Animal Drugs; Gentamicin and Betamethasone Spray

Science.gov (United States)

2012-01-25

... veterinary prescription use of gentamicin sulfate and betamethasone valerate topical spray in dogs. DATES... Veterinary Medicine (HFV-170), Food and Drug Administration, 7500 Standish Pl., Rockville, MD 20855, (240... prescription use of Gentamicin Topical Spray (gentamicin sulfate and betamethasone valerate) in dogs. Sparhawk...

Identification, antimicrobial resistance and genotypic characterization of Enterococcus spp. isolated in Porto Alegre, Brazil

Science.gov (United States)

Bender, Eduardo André; de Freitas, Ana Lúcia Peixoto; Reiter, Keli Cristine; Lutz, Larissa; Barth, Afonso Luís

2009-01-01

In the past two decades the members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. In the present study, we evaluated the antimicrobial resistance and genotypic characteristics of 203 Enterococcus spp. recovered from different clinical sources from two hospitals in Porto Alegre, Rio Grande do Sul, Brazil. The species were identified by conventional biochemical tests and by an automated system. The genetic diversity of E. faecalis presenting high-level aminoglycoside resistance (HLAR) was assessed by pulsed-field gel electrophoresis of chromosomal DNA after SmaI digestion. The E. faecalis was the most frequent specie (93.6%), followed by E. faecium (4.4%). The antimicrobial resistance profile was: 2.5% to ampicillin, 0.5% to vancomycin, 0.5% teicoplanin, 33% to chloramphenicol, 2% to nitrofurantoin, 66.1% to erythromycin, 66.5% to tetracycline, 24.6% to rifampicin, 30% to ciprofloxacin and 87.2% to quinupristin-dalfopristin. A total of 10.3% of the isolates proved to be HLAR to both gentamicin and streptomycin (HLR-ST/GE), with 23.6% resistant only to gentamicin (HLR-GE) and 37.4% only to streptomycin (HLR-ST). One predominant clonal group was found among E. faecalis HLR-GE/ST. The prevalence of resistance among beta-lactam antibiotics and glycopeptides was very low. However, in this study there was an increased number of HLR Enterococcus which may be spreading intra and inter-hospital. PMID:24031416

Transferability of a tetracycline resistance gene from probiotic Lactobacillus reuteri to bacteria in the gastrointestinal tract of humans.

Science.gov (United States)

Egervärn, Maria; Lindmark, Hans; Olsson, Johan; Roos, Stefan

2010-02-01

The potential of Lactobacillus reuteri as a donor of antibiotic resistance genes in the human gut was investigated by studying the transferability of the tetracycline resistance gene tet(W) to faecal enterococci, bifidobacteria and lactobacilli. In a double-blind clinical study, seven subjects consumed L. reuteri ATCC 55730 harbouring a plasmid-encoded tet(W) gene (tet(W)-reuteri) and an equal number of subjects consumed L. reuteri DSM 17938 derived from the ATCC 55730 strain by the removal of two plasmids, one of which contained the tet(W) gene. Faecal samples were collected before, during and after ingestion of 5 x 10(8) CFU of L. reuteri per day for 14 days. Both L. reuteri strains were detectable at similar levels in faeces after 14 days of intake but neither was detected after a two-week wash-out period. After enrichment and isolation of tetracycline resistant enterococci, bifidobacteria and lactobacilli from each faecal sample, DNA was extracted and analysed for presence of tet(W)-reuteri using a real-time PCR allelic discrimination method developed in this study. No tet(W)-reuteri signal was produced from any of the DNA samples and thus gene transfer to enterococci, bifidobacteria and lactobacilli during intestinal passage of the probiotic strain was non-detectable under the conditions tested, although transfer at low frequencies or to the remaining faecal bacterial population cannot be excluded.

Impact of an Environmental Cleaning Intervention on the Presence of Methicillin-Resistant Staphylococcus aureus and Vancomycin-Resistant Enterococci on Surfaces in Intensive Care Unit Rooms

Science.gov (United States)

Goodman, Eric R.; Platt, Richard; Bass, Richard; Onderdonk, Andrew B.; Yokoe, Deborah S.; Huang, Susan S.

2009-01-01

OBJECTIVES To evaluate the adequacy of discharge room cleaning and the impact of a cleaning intervention on the presence of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) on environmental surfaces in intensive care unit (ICU) rooms. DESIGN Prospective environmental study. SETTING AND SAMPLE Convenience sample of ICU rooms in an academic hospital. METHODS AND INTERVENTION The intervention consisted of (1) a change from the use of pour bottles to bucket immersion for applying disinfectant to cleaning cloths, (2) an educational campaign, and (3) feedback regarding adequacy of discharge cleaning. Cleaning of 15 surfaces was evaluated by inspecting for removal of a preapplied mark, visible only with an ultraviolet lamp (“black light”). Six surfaces were cultured for MRSA or VRE contamination. Outcomes of mark removal and culture positivity were evaluated by χ2 testing and generalized linear mixed models, clustering by room. RESULTS The black-light mark was removed from 44% of surfaces at baseline, compared with 71% during the intervention (P <.001). The intervention increased the likelihood of removal of black-light marks after discharge cleaning (odds ratio, 4.4; P < .001), controlling for ICU type (medical vs surgical) and type of surface. The intervention reduced the likelihood of an environmental culture positive for MRSA or VRE (proportion of cultures positive, 45% at baseline vs 27% during the intervention; adjusted odds ratio, 0.4; P = .02). Broad, flat surfaces were more likely to be cleaned than were doorknobs and sink or toilet handles. CONCLUSIONS Increasing the volume of disinfectant applied to environmental surfaces, providing education for Environmental Services staff, and instituting feedback with a black-light marker improved cleaning and reduced the frequency of MRSA and VRE contamination. PMID:18624666

Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials.

Science.gov (United States)

Celis-Aguilar, Erika; Hinojosa-González, Ramon; Vales-Hidalgo, Olivia; Coutinho-Toledo, Heloisa

Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8mL of gentamicin intratympanic application at a 30mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Ten patients were included; nine patients with Meniere's disease and one patient with (late onset) delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30dB. Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials). Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

A biodegradable gentamicin-hydroxyapatite-coating for infection prophylaxis in cementless hip prostheses

NARCIS (Netherlands)

Neut, D.; Dijkstra, R. J. B.; Thompson, J. I.; Kavanagh, C.; van der Mei, H. C.; Busscher, H. J.

2015-01-01

A degradable, poly (lactic-co-glycolic acid) (PLGA), gentamicin-loaded prophylactic coating for hydroxyapatite (HA)-coated cementless hip prostheses is developed with similar antibacterial efficacy as offered by gentamicin-loaded cements for fixing traditional, cemented prostheses in bone. We

Inhalational Gentamicin Treatment Is Effective Against Pneumonic Plague in a Mouse Model

Directory of Open Access Journals (Sweden)

David Gur

2018-04-01

Full Text Available Pneumonic plague is an infectious disease characterized by rapid and fulminant development of acute pneumonia and septicemia that results in death within days of exposure. The causative agent of pneumonic plague, Yersinia pestis (Y. pestis, is a Tier-1 bio-threat agent. Parenteral antibiotic treatment is effective when given within a narrow therapeutic window after symptom onset. However, the non-specific “flu-like” symptoms often lead to delayed diagnosis and therapy. In this study, we evaluated inhalational gentamicin therapy in an infected mouse model as a means to improve antibiotic treatment efficacy. Inhalation is an attractive route for treating lung infections. The advantages include directly dosing the main infection site, the relative accessibility for administration and the lack of extensive enzymatic drug degradation machinery. In this study, we show that inhalational gentamicin treatment administered 24 h post-infection, prior to the appearance of symptoms, protected against lethal intranasal challenge with the fully virulent Y. pestis Kimberley53 strain (Kim53. Similarly, a high survival rate was demonstrated in mice treated by inhalation with another aminoglycoside, tobramycin, for which an FDA-approved inhaled formulation is clinically available for cystic fibrosis patients. Inhalational treatment with gentamicin 48 h post-infection (to symptomatic mice was also successful against a Y. pestis challenge dose of 10 i.n.LD50. Whole-body imaging using IVIS technology demonstrated that adding inhalational gentamicin to parenteral therapy accelerated the clearance of Y. pestis from the lungs of infected animals. This may reduce disease severity and the risk of secondary infections. In conclusion, our data suggest that inhalational therapy with aerosolized gentamicin may be an effective prophylactic treatment against pneumonic plague. We also demonstrate the benefit of combining this treatment with a conventional parenteral

Reduction of clarithromycin and sulfamethoxazole-resistant Enterococcus by pilot-scale solar-driven Fenton oxidation.

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Karaolia, Popi; Michael, Irene; García-Fernández, Irene; Agüera, Ana; Malato, Sixto; Fernández-Ibáñez, Pilar; Fatta-Kassinos, Despo

2014-01-15

The presence of pathogenic antibiotic-resistant bacteria in aquatic environments has become a health threat in the last few years. Their presence has increased due to the presence of antibiotics in wastewater effluents, which are not efficiently removed by conventional wastewater treatments. As a result there is a need to study the possible ways of removal of the mixtures of antibiotics present in wastewater effluents and the antibiotic-resistant bacteria, which may also spread the antibiotic resistance genes to other bacterial populations. In this study the degradation of a mixture of antibiotics i.e. sulfamethoxazole and clarithromycin, the disinfection of total enterococci and the removal of those resistant to: a) sulfamethoxazole, b) clarithromycin and c) to both antibiotics have been examined, along with the toxicity of the whole effluent mixture after treatment to the luminescent aquatic bacterium Vibrio fischeri. Solar Fenton treatment (natural solar driven oxidation) using Fenton reagent doses of 50 mg L(-1) of hydrogen peroxide and 5 mg L(-1) of Fe(3+) in a pilot-scale compound parabolic collector plant was used to examine the disinfection and antibiotic resistance removal efficiency in different aqueous matrices, namely distilled water, simulated and real wastewater effluents. There was a faster complete removal of enterococci and of antibiotics in all aqueous matrices by applying solar Fenton when compared to photolytic treatment of the matrices. Sulfamethoxazole was more efficiently degraded than clarithromycin in all three aqueous matrices (95% removal of sulfamethoxazole and 70% removal of clarithromycin in real wastewater). The antibiotic resistance of enterococci towards both antibiotics exhibited a 5-log reduction with solar Fenton in real wastewater effluent. Also after solar Fenton treatment, there were 10 times more antibiotic-resistant enterococci in the presence of sulfamethoxazole than in the presence of clarithromycin. Finally, the toxicity

Antimicrobial-Resistant Bacterial Populations and Antimicrobial Resistance Genes Obtained from Environments Impacted by Livestock and Municipal Waste.

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Getahun E Agga

Full Text Available This study compared the populations of antimicrobial-resistant bacteria and the repertoire of antimicrobial resistance genes in four environments: effluent of three municipal wastewater treatment facilities, three cattle feedlot runoff catchment ponds, three swine waste lagoons, and two "low impact" environments (an urban lake and a relict prairie. Multiple liquid and solid samples were collected from each environment. The prevalences and concentrations of antimicrobial-resistant (AMR Gram-negative (Escherichia coli and Salmonella enterica and Gram-positive (enterococci bacteria were determined from individual samples (n = 174. The prevalences of 84 antimicrobial resistance genes in metagenomic DNA isolated from samples pooled (n = 44 by collection date, location, and sample type were determined. The prevalences and concentrations of AMR E. coli and Salmonella were similar among the livestock and municipal sample sources. The levels of erythromycin-resistant enterococci were significantly higher in liquid samples from cattle catchment ponds and swine waste lagoons than in liquid samples from municipal wastewater treatment facilities, but solid samples from these environments did not differ significantly. Similarly, trimethoprim/sulfamethoxazole-resistant E. coli concentrations were significantly higher in swine liquid than in municipal liquid samples, but there was no difference in solid samples. Multivariate analysis of the distribution of antimicrobial resistance genes using principal coordinate analysis showed distinct clustering of samples with livestock (cattle and swine, low impact environment and municipal samples forming three separate clusters. The numbers of class A beta-lactamase, class C beta-lactamase, and fluoroquinolone resistance genes detected were significantly higher (P < 0.05 in municipal samples than in cattle runoff or swine lagoon samples. In conclusion, we report that AMR is a very widespread phenomenon and that similar

Partridge embryo pathology in relation to gentamicin-induced lesions

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Hadi Tavakkoli

2016-10-01

Full Text Available Objective: To determine the macroscopic and microscopic lesions of various dosages of gentamicin in the partridge embryo. Methods: Fertile chukar partridge eggs were allocated into four groups. Group 1: salineinjected group whose individuals were administered by sterile physiological saline solution of 0.2 mL/egg inserted into yolk sac. Groups 2, 3 and 4 whose individuals were similarly administered by gentamicin sulfate at a dosage of 80 mg/kg egg-weight once, twice and three times, respectively. Results: Results showed that the embryos were congested and stunted in the gentamicininjected groups. Defects in feet, wings and feather development were accompanied by microscopic lesions in brain, meninges, heart, lungs, liver and kidneys. Histopathological lesions were noticed as edema, undeveloped tissues, necrosis and degeneration in the affected organs. Conclusions: Based on acquired results, it is concluded that gentamicin at above-described dosages causes toxicopathological effects to the partridge embryo in a dose dependent manner.

Defence strategies and antibiotic resistance gene abundance in enterococci under stress by exposure to low doses of peracetic acid.

Science.gov (United States)

Turolla, Andrea; Sabatino, Raffaella; Fontaneto, Diego; Eckert, Ester M; Colinas, Noemi; Corno, Gianluca; Citterio, Barbara; Biavasco, Francesca; Antonelli, Manuela; Mauro, Alessandro; Mangiaterra, Gianmarco; Di Cesare, Andrea

2017-10-01

Peracetic acid (PAA) is an organic compound used efficiently as disinfectant in wastewater treatments. Yet, at low doses it may cause selection; thus, the effect of low doses of PAA on Enterococcus faecium as a proxy of human-related microbial waste was evaluated. Bacteria were treated with increasing doses of PAA (from 0 to 25 mg L -1 min) and incubated in regrowth experiments under non-growing, limiting conditions and under growing, favorable conditions. The changes in bacterial abundance, in bacterial phenotype (number and composition of small cell clusters), and in the abundance of an antibiotic resistance gene (ARG) was evaluated. The experiment demonstrated that the selected doses of PAA efficiently removed enterococci, and induced a long-lasting effect after PAA inactivation. The relative abundance of small clusters increased during the experiment when compared with that of the inoculum. Moreover, under growing favorable conditions the relative abundance of small clusters decreased and the number of cells per cluster increased with increasing PAA doses. A strong stability of the measured ARG was found, not showing any effect during the whole experiment. The results demonstrated the feasibility of low doses of PAA to inactivate bacteria. However, the stress induced by PAA disinfection promoted a bacterial adaptation, even if potentially without affecting the abundance of the ARG. Copyright © 2017 Elsevier Ltd. All rights reserved.

An experimental design approach to the preparation of pegylated polylactide-co-glicolide gentamicin loaded microparticles for local antibiotic delivery

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Dorati, Rossella; DeTrizio, Antonella; Genta, Ida; Grisoli, Pietro; Merelli, Alessia [Department of Drug Sciences, Viale Taramelli 12, University of Pavia, 27100, Pavia (Italy); Tomasi, Corrado [IENI CNR Lecco Unit, Via Promessi Sposi 29, 23900, Lecco (Italy); Conti, Bice, E-mail: bice.conti@unipv.it [Department of Drug Sciences, Viale Taramelli 12, University of Pavia, 27100, Pavia (Italy)

2016-01-01

The present paper takes into account the DOE application to the preparation process of biodegradable microspheres for osteomyelitis local therapy. With this goal gentamicin loaded polylactide-co-glycolide-co-polyethyleneglycol (PLGA-PEG) microspheres were prepared and investigated. Two preparation protocols (o/w and w/o/w) with different process conditions, and three PLGA-PEG block copolymers with different compositions of lactic and glycolic acids and PEG, were tested. A Design Of Experiment (DOE) screening design was applied as an approach to scale up manufacturing step. The results of DOE screening design confirmed that w/o/w technique, the presence of salt and the 15%w/v polymer concentration positively affected the EE% (72.1–97.5%), and span values of particle size distribution (1.03–1.23), while salt addition alone negatively affected the yield process. Process scale up resulted in a decrease of gentamicin EE% that can be attributed to the high volume of water used to remove PVA and NaCl residues. The results of in vitro gentamicin release study show prolonged gentamicin release up to three months from the microspheres prepared with salt addition in the dispersing phase; the behavior being consistent with their highly compact structure highlighted by scanning electron microscopy analysis. The prolonged release of gentamicin is maintained even after embedding the biodegradable microspheres into a thermosetting composite gel made of chitosan and acellular bovine bone matrix (Orthoss® granules), and the microbiologic evaluation demonstrated the efficacy of the gentamicin loaded microspheres on Escherichia coli. The collected results confirm the feasibility of the scale up of microsphere manufacturing process and the high potential of the microparticulate drug delivery system to be used for the local antibiotic delivery to bone. - Highlights: • To get a more effective therapy for the prevention and treatment of osteomyelitis. • To exploit the local

One dose per day compared to multiple doses per day of gentamicin for treatment of suspected or proven sepsis in neonates.

Science.gov (United States)

Rao, Shripada C; Srinivasjois, Ravisha; Moon, Kwi

2016-12-06

(typical RR 1.69, 95% CI 0.18 to 16.25; typical RD 0.01, 95% CI -0.04 to 0.05; 5 trials; N = 214). Nephrotoxicity was not noted with either of the treatment regimens. Overall, the quality of evidence was considered to be moderate on GRADE analysis, given the small sample size and unclear/high risk of bias in some of the domains in a few of the included studies. There is insufficient evidence from the currently available RCTs to conclude whether a 'once a day' or a 'multiple doses a day' regimen of gentamicin is superior in treating proven neonatal sepsis. However, data suggest that pharmacokinetic properties of a 'once a day' gentamicin regimen are superior to a 'multiple doses a day' regimen in that it achieves higher peak levels while avoiding toxic trough levels. There was no change in nephrotoxicity or auditory toxicity. Based on the assessment of pharmacokinetics, a 'once a day regimen' may be superior in treating sepsis in neonates of more than 32 weeks' gestation.

Evaluation of novel biomarkers of nephrotoxicity in Cynomolgus monkeys treated with gentamicin

International Nuclear Information System (INIS)

Gautier, Jean-Charles; Zhou, Xiaobing; Yang, Yi; Gury, Thierry; Qu, Zhe; Palazzi, Xavier; Léonard, Jean-François; Slaoui, Mohamed; Veeranagouda, Yaligara; Guizon, Isabelle; Boitier, Eric; Filali-Ansary, Aziz; Berg, Bart H.J. van den; Poetz, Oliver; Joos, Thomas; Zhang, Tianyi; Wang, Jufeng; Detilleux, Philippe; Li, Bo

2016-01-01

Most studies to evaluate kidney safety biomarkers have been performed in rats. This study was conducted in Cynomolgus monkeys in order to evaluate the potential usefulness of novel biomarkers of nephrotoxicity in this species. Groups of 3 males were given daily intramuscular injections of gentamicin, a nephrotoxic agent known to produce lesions in proximal tubules, at dose-levels of 10, 25, or 50 mg/kg/day for 10 days. Blood and 16-h urine samples were collected on Days − 7, − 3, 2, 4, 7, and at the end of the dosing period. Several novel kidney safety biomarkers were evaluated, with single- and multiplex immunoassays and in immunoprecipitation-LC/MS assays, in parallel to histopathology and conventional clinical pathology parameters. Treatment with gentamicin induced a dose-dependent increase in kidney tubular cell degeneration/necrosis, ranging from minimal to mild severity at 10 mg/kg/day, moderate at 25 mg/kg/day, and to severe at 50 mg/kg/day. The results showed that the novel urinary biomarkers, microalbumin, α1-microglobulin, clusterin, and osteopontin, together with the more traditional clinical pathology parameters, urinary total protein and N-acetyl-β-D-glucosaminidase (NAG), were more sensitive than blood urea nitrogen (BUN) and serum creatinine (sCr) to detect kidney injury in the monkeys given 10 mg/kg/day gentamicin for 10 days, a dose leading to an exposure which is slightly higher than the desired therapeutic exposure in clinics. Therefore, these urinary biomarkers represent non-invasive biomarkers of proximal tubule injury in Cynomolgus monkeys which may be potentially useful in humans. - Highlights: • Gentamicin induced kidney tubular cell degeneration/necrosis in Cynomolgus monkey • Urinary clusterin and osteopontin were sensitive biomarkers of kidney injury. • Microalbumin and α1-microglobulin in urine were also more sensitive than serum creatinine.

Evaluation of novel biomarkers of nephrotoxicity in Cynomolgus monkeys treated with gentamicin

Energy Technology Data Exchange (ETDEWEB)

Gautier, Jean-Charles, E-mail: jean-charles.gautier@sanofi.com [Sanofi R& D, Vitry-sur-Seine (France); Zhou, Xiaobing [National Center for Safety Evaluation of Drugs (NCSED), National Institutes for Food and Drug Control, Beijing (China); Yang, Yi [Sanofi R& D, Bridgewater (United States); Gury, Thierry [Sanofi R& D, Vitry-sur-Seine (France); Qu, Zhe [National Center for Safety Evaluation of Drugs (NCSED), National Institutes for Food and Drug Control, Beijing (China); Palazzi, Xavier; Léonard, Jean-François; Slaoui, Mohamed; Veeranagouda, Yaligara; Guizon, Isabelle; Boitier, Eric; Filali-Ansary, Aziz [Sanofi R& D, Vitry-sur-Seine (France); Berg, Bart H.J. van den; Poetz, Oliver; Joos, Thomas [Natural and Medical Sciences Institute at the University Tübingen (Germany); Zhang, Tianyi [Frontage Laboratories, Shanghai (China); Wang, Jufeng [National Center for Safety Evaluation of Drugs (NCSED), National Institutes for Food and Drug Control, Beijing (China); Detilleux, Philippe [Sanofi R& D, Vitry-sur-Seine (France); Li, Bo, E-mail: libo@nifdc.org.cn [National Center for Safety Evaluation of Drugs (NCSED), National Institutes for Food and Drug Control, Beijing (China)

2016-07-15

Most studies to evaluate kidney safety biomarkers have been performed in rats. This study was conducted in Cynomolgus monkeys in order to evaluate the potential usefulness of novel biomarkers of nephrotoxicity in this species. Groups of 3 males were given daily intramuscular injections of gentamicin, a nephrotoxic agent known to produce lesions in proximal tubules, at dose-levels of 10, 25, or 50 mg/kg/day for 10 days. Blood and 16-h urine samples were collected on Days − 7, − 3, 2, 4, 7, and at the end of the dosing period. Several novel kidney safety biomarkers were evaluated, with single- and multiplex immunoassays and in immunoprecipitation-LC/MS assays, in parallel to histopathology and conventional clinical pathology parameters. Treatment with gentamicin induced a dose-dependent increase in kidney tubular cell degeneration/necrosis, ranging from minimal to mild severity at 10 mg/kg/day, moderate at 25 mg/kg/day, and to severe at 50 mg/kg/day. The results showed that the novel urinary biomarkers, microalbumin, α1-microglobulin, clusterin, and osteopontin, together with the more traditional clinical pathology parameters, urinary total protein and N-acetyl-β-D-glucosaminidase (NAG), were more sensitive than blood urea nitrogen (BUN) and serum creatinine (sCr) to detect kidney injury in the monkeys given 10 mg/kg/day gentamicin for 10 days, a dose leading to an exposure which is slightly higher than the desired therapeutic exposure in clinics. Therefore, these urinary biomarkers represent non-invasive biomarkers of proximal tubule injury in Cynomolgus monkeys which may be potentially useful in humans. - Highlights: • Gentamicin induced kidney tubular cell degeneration/necrosis in Cynomolgus monkey • Urinary clusterin and osteopontin were sensitive biomarkers of kidney injury. • Microalbumin and α1-microglobulin in urine were also more sensitive than serum creatinine.

Antibiotic-Resistant Enteric Bacteria in Environmental Waters

OpenAIRE

Lisa M. Casanova; Mark D. Sobsey

2016-01-01

Sources of antibiotic resistant organisms, including concentrated animal feeding operations (CAFOs), may lead to environmental surface and groundwater contamination with resistant enteric bacteria of public health concern. The objective of this research is to determine whether Salmonella, Escherichia coli, Yersinia enterocolitica, and enterococci resistant to clinically relevant antibiotics are present in surface and groundwater sources in two eastern North Carolina counties, Craven and Wayne...

Solar photo-Fenton process on the abatement of antibiotics at a pilot scale: Degradation kinetics, ecotoxicity and phytotoxicity assessment and removal of antibiotic resistant enterococci.

Science.gov (United States)

Michael, I; Hapeshi, E; Michael, C; Varela, A R; Kyriakou, S; Manaia, C M; Fatta-Kassinos, D

2012-11-01

This work investigated the application of a solar driven advanced oxidation process (solar photo-Fenton), for the degradation of antibiotics at low concentration level (μg L(-1)) in secondary treated domestic effluents at a pilot-scale. The examined antibiotics were ofloxacin (OFX) and trimethoprim (TMP). A compound parabolic collector (CPC) pilot plant was used for the photocatalytic experiments. The process was mainly evaluated by a fast and reliable analytical method based on a UPLC-MS/MS system. Solar photo-Fenton process using low iron and hydrogen peroxide doses ([Fe(2+)](0) = 5 mg L(-1); [H(2)O(2)](0) = 75 mg L(-1)) was proved to be an efficient method for the elimination of these compounds with relatively high degradation rates. The photocatalytic degradation of OFX and TMP with the solar photo-Fenton process followed apparent first-order kinetics. A modification of the first-order kinetic expression was proposed and has been successfully used to explain the degradation kinetics of the compounds during the solar photo-Fenton treatment. The results demonstrated the capacity of the applied advanced process to reduce the initial wastewater toxicity against the examined plant species (Sorghum saccharatum, Lepidium sativum, Sinapis alba) and the water flea Daphnia magna. The phytotoxicity of the treated samples, expressed as root growth inhibition, was higher compared to that observed on the inhibition of seed germination. Enterococci, including those resistant to OFX and TMP, were completely eliminated at the end of the treatment. The total cost of the full scale unit for the treatment of 150 m(3) day(-1) of secondary wastewater effluent was found to be 0.85 € m(-3). Copyright © 2012 Elsevier Ltd. All rights reserved.

Survival potential of Escherichia coli and Enterococci in subtropical beach sand: implications for water quality managers.

Science.gov (United States)

Hartz, A; Cuvelier, M; Nowosielski, K; Bonilla, T D; Green, M; Esiobu, N; McCorquodale, D S; Rogerson, A

2008-01-01

Fecal bacteria have traditionally been used as indicator organisms to monitor the quality of recreational waters. Recent work has questioned the robustness of traditional indicators, particularly at seawater bathing beaches. For example, a study of Florida beaches found unexpectedly high abundances of Escherichia coli, fecal coliforms, and enterococci in beach sand. The aim of the present study was to explain these abundances by assessing the survival of E. coli and enterococci in beach sand relative to seawater. We used a combination of quantitative laboratory mesocosm experiments and field observations. Results suggested that E. coli and enterococci exhibited increased survivability and growth in sand relative to seawater. Because fecal bacteria are capable of replicating in sand, at least under controlled laboratory conditions, the results suggest that sand may be an important reservoir of metabolically active fecal organisms. Experiments with "natural" mesocosms (i.e., unsterilized sand or water rich in micropredators and native bacteria) failed to show the same increases in fecal indicators as was found in sterile sand. It is postulated that this was due to predation and competition with indigenous bacteria in these "natural" systems. Nonetheless, high populations of indicators were maintained and recovered from sand over the duration of the experiment as opposed to the die-off noted in water. Indicator bacteria may wash out of sand into shoreline waters during weather and tidal events, thereby decreasing the effectiveness of these indicators as predictors of health risk and complicating the interpretations for water quality managers.

Protective effect of hydroalcoholic extract of Pistacia vera against gentamicin-induced nephrotoxicity in rats.

Science.gov (United States)

Ehsani, Vahid; Amirteimoury, Morteza; Taghipour, Zahra; Shamsizadeh, Ali; Bazmandegan, Gholamreza; Rahnama, Amir; Khajehasani, Fatemeh; Fatemi, Iman

2017-11-01

Pistacia vera is a plant of the family Anacardiaceae found in Central and West Asia. P. vera nut (Pistachio) possess multiple pharmacological effects such as antimicrobial, anti-hyperlipidemia, antioxidant and anti-inflammatory. This study is designed to evaluate the protective effect of the hydroalcoholic extract of pistachio on gentamicin-induced nephrotoxicity in rats. Nephrotoxicity was induced in rats by intraperitoneal injection of gentamicin (100 mg/kg/day for 7 days). Hydroalcoholic extract of pistachio (10, 50 and 100 mg/kg/p.o) was administered for 7 days. The nephroprotective activity was evaluated by determining creatinine clearance, serum creatinine, urine volume, urine glucose and blood urea nitrogen (BUN) levels. The kidneys were processed for histopathological examinations and all specimens were examined for morphologic parameters involving tubular degeneration, tubular necrosis and tubule interstitial nephritis. Results showed a significant increase in the levels of serum creatinine, urine volume, urine glucose and BUN and decrease of creatinine clearance by gentamicin (GA) administration. Co-administration with pistachio extract showed reduction in the levels of serum creatinine, urine volume, urine glucose and BUN and increase of creatinine clearance in all doses but the most significant alteration was observed in doses of 100 mg/kg. Also, the nephroprotective effect of the GA was confirmed by the histological examination of the kidneys. The study revealed the nephroprotective effect of the hydroalcoholic extract of pistachio. These findings suggest that pistachio treatment may attenuate renal dysfunction and structural damage through the reduction of oxidative stress and inflammation in the kidney.

Multiple antibiotics resistant among environmental isolates of ...

African Journals Online (AJOL)

In this study we assessed the functionality of integrons, melanin-like pigment and biofilm formation on multidrug resistance among environmental isolates of Stenotrophomonas maltophilia. Marked resistances were noted against aztreonam (60%), cefepime (68%), ceftazidime (77%), ciprofloxacin (72%), gentamicin (65%), ...

Studies of labelling conditions for gentamicin with99mTc Biological uptake

International Nuclear Information System (INIS)

Carvalho, O.G. de; Almeida, M.A.T.M. de; Muramoto, E.

1989-10-01

Gentamicin sulphate is an aminoglycoside antibiotic type specifically used for treatment of infections produced by Gram-negative bacterias but on the hand it presents ototoxic reactions as a serious side effect. The optimal labelling conditions of gentamicin sulphate with 99m Tc, using sodium pertechnetate solutions eluted from a 99 Mo - 99m Tc generator, were stablished by testing differents masses of antibiotic and reducing agent (SnCl 2 .2H 2 O), and also different reaction times and final labelling pH. The labelling yields were determined through ascendent type crimatographic analysis using metylacetone and 0,9% NaCl solution as solvents. From the studies of the biological uptake of 99m Tc gentamicin sulphate per gram of eight different organs and tissues from Wistar rats, it was shown that for a dose of 0,3 mg of 99m Tc-gentamicin intravenously administered. The kidneys, presented the greatest affinity for the drug, being thus the main excretory organs of the product. (author) [pt

Resistência antimicrobiana em Salmonella Enteritidis isoladas de amostras clínicas e ambientais de frangos de corte e matrizes pesadas Antimicrobial resistance in Salmonella Enteritidis isolated from clinical and environmental broiler chickens and breeders broiler

Directory of Open Access Journals (Sweden)

A.R. Ribeiro

2008-10-01

Full Text Available The antimicrobial resistance of Salmonella Enteritidis strains isolated from clinical and environmental poultry samples in the Southern Brazil during the years of 1999, 2000 and 2001 was evaluated. Among the 79 isolated samples, 64 (81% were resistant to at least one of the antimicrobial agents tested, showing 22 different resistance patterns. Tetracycline showed the highest percentage (64,5% of resistance among the antimicrobial agents used. Resistance to drugs at different levels was found as the following: ampicillin (1.2%, kanamycin (1.2%, ciprofloxacin (2.5%, enrofloxacin (8.8%, gentamicin (21.5%, streptomycin (20.2%, nitrofurantoin (26.6%, and nalidixic acid (30.4%. None of the S. Enteritidis strains were resistant to chloramphenicol, norfloxacin, and polimycin B. Among the 64 S. Enteritidis strains that showed resistance, 43 (67.2% were resistant to two or more antimicrobial agents. Twenty-one (32.8% strains were resistant to only one of the antimicrobial agents, 14 to tetracycline, three to nalidixic acid, three to nitrofurantoin, and one to gentamycin. These antimicrobial resistance levels suggest a high occurrence of tetracycline resistant S. Enteritidis strains and resistance to two or more antimicrobial agents.

Low-level quinolone-resistance in multi-drug resistant typhoid

Energy Technology Data Exchange (ETDEWEB)

Mirza, S H; Khan, M A [Armed Forces Inst. of Pathology, Rawalpindi (Pakistan). Dept. of Microbiolgy

2008-01-15

To find out the frequency of low-level quinolone-resistance in Multi-Drug Resistant (MDR) typhoid using nalidixic acid screening disc. Blood was obtained from suspected cases of typhoid fever and cultured in to BacT/ALERT. The positive blood cultures bottles were subcultured. The isolates were identified by colony morphology and biochemical tests using API-20E galleries. Susceptibility testing of isolates was done by modified Kirby-Bauer disc diffusion method on Muellar Hinton Agar. For the isolates, which were resistant to nalidixic acid by disc diffusion method, Minimal Inhibitory Concentrations (MICs) of ciprofloxacin and nalidixic acid were determined by using the E-test strips. Disc diffusion susceptibility tests and MICs were interpreted according to the guidelines provided by National Committee for Control Laboratory Standard (NCCLS). A total of 21(65.5%) out of 32 isolates of Salmonellae were nalidixic acid-resistant by disk diffusion method. All the nalidixic acid-resistant isolates by disc diffusion method were confirmed by MICs for both ciprofloxacin and nalidixic acid. All the nalidixic acid-resistant isolates had a ciprofloxacin MIC of 0.25-1 microg/ml (reduced susceptibility) and nalidixic acid MICs > 32 microg (resistant). Out of all Salmonella isolates, 24 (75%) were found to be MDR, and all were S. typbi. Low-level quinolone-resistance in typhoid was high in this small series. Screening for nalidixic acid resistance with a 30 microg nalidixic acid disk is a reliable and cost-effective method to detect low-level fluoroquinolone resistance, especially in the developing countries. (author)

Low-level quinolone-resistance in multi-drug resistant typhoid

International Nuclear Information System (INIS)

Mirza, S.H.; Khan, M.A.

2008-01-01

To find out the frequency of low-level quinolone-resistance in Multi-Drug Resistant (MDR) typhoid using nalidixic acid screening disc. Blood was obtained from suspected cases of typhoid fever and cultured in to BacT/ALERT. The positive blood cultures bottles were subcultured. The isolates were identified by colony morphology and biochemical tests using API-20E galleries. Susceptibility testing of isolates was done by modified Kirby-Bauer disc diffusion method on Muellar Hinton Agar. For the isolates, which were resistant to nalidixic acid by disc diffusion method, Minimal Inhibitory Concentrations (MICs) of ciprofloxacin and nalidixic acid were determined by using the E-test strips. Disc diffusion susceptibility tests and MICs were interpreted according to the guidelines provided by National Committee for Control Laboratory Standard (NCCLS). A total of 21(65.5%) out of 32 isolates of Salmonellae were nalidixic acid-resistant by disk diffusion method. All the nalidixic acid-resistant isolates by disc diffusion method were confirmed by MICs for both ciprofloxacin and nalidixic acid. All the nalidixic acid-resistant isolates had a ciprofloxacin MIC of 0.25-1 microg/ml (reduced susceptibility) and nalidixic acid MICs > 32 microg (resistant). Out of all Salmonella isolates, 24 (75%) were found to be MDR, and all were S. typbi. Low-level quinolone-resistance in typhoid was high in this small series. Screening for nalidixic acid resistance with a 30 microg nalidixic acid disk is a reliable and cost-effective method to detect low-level fluoroquinolone resistance, especially in the developing countries. (author)

High Mortality from Blood Stream Infection in Addis Ababa, Ethiopia, Is Due to Antimicrobial Resistance.

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Teshale Seboxa

Full Text Available Managing blood stream infection in Africa is hampered by lack of bacteriological support needed for antimicrobial stewardship, and background data needed for empirical treatment. A combined pro- and retrospective approach was used to overcome thresholds in clinical research in Africa.Outcome and characteristics including age, HIV infection, pancytopenia and bacteriological results were studied in 292 adult patients with two or more SIRS criteria using univariate and confirming multivariate logistic regression models. Expected randomly distributed resistance covariation was compared with observed co-resistance among gram-negative enteric bacteria in 92 paediatric blood culture isolates that had been harvested in the same hospital during the same period of time.Mortality was fivefold increased among patients with positive blood culture results [50.0% vs. 9.8%; OR 11.24 (4.38-25.88, p < 0.0001], and for this group of patients mortality was significantly associated with antimicrobial resistance [OR 23.28 (3.3-164.4, p = 0.002]. All 11 patients with Enterobacteriaceae resistant to 3rd. generation cephalosporins died. Eighty-nine patients had pancytopenia grade 3-4. Among patients with negative blood culture results, mortality was significantly associated with pancytopenia [OR 3.12 (1.32-7.39, p = 0.01]. HIV positivity was not associated with increased mortality. Antimicrobial resistance that concerned gram-negative enteric bacteria, regardless of species, was characterized by co-resistance between third generation cephalosporins, gentamicin, chloramphenicol, and co-trimoxazole.Mortality was strongly associated with growth of bacteria resistant to empirical treatment, and these patients were dead or dying when bacteriological reports arrived. Because of co-resistance, alternative efficient antibiotics would not have been available in Ethiopia for 8/11 Enterobacteriaceae-infected patients with isolates resistant to third generation cephalosporins

High levels of X-linked Inhibitor-of-Apoptosis Protein (XIAP) are indicative of radio chemotherapy resistance in rectal cancer

International Nuclear Information System (INIS)

Flanagan, L.; Kehoe, J.; Fay, J.; Bacon, O.; Lindner, A.U.; Kay, E.W.; Deasy, J.; McNamara, D.A.; Prehn, J.H.M.

2015-01-01

The mainstay of treatment in rectal cancer is neoadjuvant radio chemotherapy prior to surgery, in an attempt to downstage the tumour, allowing for more complete removal during surgery. In 40 % of cases however, this neoadjuvant radio chemotherapy fails to achieve tumour regression, partly due insufficient apoptosis signaling. X-linked Inhibitor of Apoptosis Protein (XIAP) is an anti-apoptotic protein that has been reported to contribute to disease progression and chemotherapy resistance. We obtained rectal biopsy normal and matched tumour tissue from 29 rectal cancer patients with varying degrees of tumour regression, and using Western blot, examined anti-apoptotic XIAP and pro-apoptotic Smac protein levels in these tissues, with the aim to examine whether disturbed XIAP/Smac levels may be an indicator of neoadjuvant radio chemotherapy resistance. Expression of inhibitor of apoptosis proteins cIAP-1 and cIAP-2 was also examined. We found that levels of XIAP increased in accordance with the degree of radio chemotherapy resistance of the tissue. Levels of this protein were also significantly higher in tumour tissue, compared to matched normal tissue in highly resistant tissue. In contrast, Smac protein levels did not increase with radio chemotherapy resistance, and the protein was similarly expressed in normal and tumour tissue, indicating a shift in the balance of these proteins. Post treatment surgical resection tissue was available for 8 patients. When we compared matched tissue pre- and post- radio chemotherapy we found that XIAP levels increased significantly during treatment in both normal and tumour tissue, while Smac levels did not change. cIAP-1 and cIAP-2 levels were not differentially expressed in varying degrees of radio chemotherapy resistance, and neoadjuvant therapy did not alter expression of these proteins. These data indicate that disturbance of the XIAP/Smac balance may be a driver of radio chemotherapy resistance, and hence high levels of XIAP may

Genome-wide identification of antimicrobial intrinsic resistance determinants in Staphylococcus aureus

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Martin Vestergaard

2016-12-01

Full Text Available The emergence of antimicrobial resistance severely threatens our ability to treat bacterial infections. While acquired resistance has received considerable attention, relatively little is known of intrinsic resistance that allows bacteria to naturally withstand antimicrobials. Gene products that confer intrinsic resistance to antimicrobial agents may be explored for alternative antimicrobial therapies, by potentiating the efficacy of existing antimicrobials. In this study, we identified the intrinsic resistome to a broad spectrum of antimicrobials in the human pathogen, Staphylococcus aureus. We screened the Nebraska Transposon Mutant Library of 1920 single-gene inactivations in S. aureus strain JE2, for increased susceptibility to the anti-staphylococcal antimicrobials (ciprofloxacin, oxacillin, linezolid, fosfomycin, daptomycin, mupirocin, vancomycin and gentamicin. 68 mutants were confirmed by E-test to display at least two-fold increased susceptibility to one or more antimicrobial agents. The majority of the identified genes have not previously been associated with antimicrobial susceptibility in S. aureus. For example, inactivation of genes encoding for subunits of the ATP synthase, atpA, atpB, atpG and atpH, reduced the minimum inhibitory concentration (MIC of gentamicin 16-fold. To elucidate the potential of the screen, we examined treatment efficacy in the Galleria mellonella infection model. Gentamicin efficacy was significantly improved, when treating larvae infected with the atpA mutant compared to wild type cells with gentamicin at a clinically relevant concentration. Our results demonstrate that many gene products contribute to the intrinsic antimicrobial resistance of S. aureus. Knowledge of these intrinsic resistance determinants provides alternative targets for compounds that may potentiate the efficacy of existing antimicrobial agents against this important pathogen.

Frequent detection of a human fecal indicator in the urban ocean: environmental drivers and covariation with enterococci.

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Jennings, Wiley C; Chern, Eunice C; O'Donohue, Diane; Kellogg, Michael G; Boehm, Alexandria B

2018-03-01

Fecal pollution of surface waters presents a global human health threat. New molecular indicators of fecal pollution have been developed to address shortcomings of traditional culturable fecal indicators. However, there is still little information on their fate and transport in the environment. The present study uses spatially and temporally extensive data on traditional (culturable enterococci, cENT) and molecular (qPCR-enterococci, qENT and human-associated marker, HF183/BacR287) indicator concentrations in marine water surrounding highly-urbanized San Francisco, California, USA to investigate environmental and anthropogenic processes that impact fecal pollution. We constructed multivariable regression models for fecal indicator bacteria at 14 sampling stations. The human marker was detected more frequently in our study than in many other published studies, with detection frequency at some stations as high as 97%. The odds of cENT, qENT, and HF183/BacR287 exceeding health-relevant thresholds were statistically elevated immediately following discharges of partially treated combined sewage, and cENT levels dissipated after approximately 1 day. However, combined sewer discharges were not important predictors of indicator levels typically measured in weekly monitoring samples. Instead, precipitation and solar insolation were important predictors of cENT in weekly samples, while precipitation and water temperature were important predictors of HF183/BacR287 and qENT. The importance of precipitation highlights the significance of untreated storm water as a source of fecal pollution to the urban ocean, even for a city served by a combined sewage system. Sunlight and water temperature likely control persistence of the indicators via photoinactivation and dark decay processes, respectively.

Significance of beach geomorphology on fecal indicator bacteria levels.

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Donahue, Allison; Feng, Zhixuan; Kelly, Elizabeth; Reniers, Ad; Solo-Gabriele, Helena M

2017-08-15

Large databases of fecal indicator bacteria (FIB) measurements are available for coastal waters. With the assistance of satellite imagery, we illustrated the power of assessing data for many sites by evaluating beach features such as geomorphology, distance from rivers and canals, presence of piers and causeways, and degree of urbanization coupled with the enterococci FIB database for the state of Florida. We found that beach geomorphology was the primary characteristic associated with enterococci levels that exceeded regulatory guidelines. Beaches in close proximity to marshes or within bays had higher enterococci exceedances in comparison to open coast beaches. For open coast beaches, greater enterococci exceedances were associated with nearby rivers and higher levels of urbanization. Piers and causeways had a minimal contribution, as their effect was often overwhelmed by beach geomorphology. Results can be used to understand the potential causes of elevated enterococci levels and to promote public health. Copyright © 2017 Elsevier Ltd. All rights reserved.

Growth and survival of Escherichia coli and enterococci populations in the macro-alga Cladophora (Chlorophyta).

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Byappanahalli, Muruleedhara N; Shively, Dawn A; Nevers, Meredith B; Sadowsky, Michael J; Whitman, Richard L

2003-11-01

The macro-alga Cladophora glomerata is found in streams and lakes worldwide. High concentrations of Escherichia coli and enterococci have been reported in Cladophora along the Lake Michigan shore. The objective of this study was to determine if Cladophora supported growth of these indicator bacteria. Algal leachate readily supported in vitro multiplication of E. coli and enterococci, suggesting that leachates contain necessary growth-promoting substances. Growth was directly related to the concentration of algal leachate. E. coli survived for over 6 months in dried Cladophora stored at 4 degrees C; residual E. coli grew after mat rehydration, reaching a carrying capacity of 8 log CFU g(-1) in 48 h. Results of this study also show that the E. coli strains associated with Cladophora are highly related; in most instances they are genetically different from each other, suggesting that the relationship between E. coli and Cladophora may be casual. These findings indicate that Cladophora provides a suitable environment for indicator bacteria to persist for extended periods and to grow under natural conditions.

Application of Box-Behnken design to prepare gentamicin-loaded calcium carbonate nanoparticles.

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Maleki Dizaj, Solmaz; Lotfipour, Farzaneh; Barzegar-Jalali, Mohammad; Zarrintan, Mohammad-Hossein; Adibkia, Khosro

2016-09-01

The aim of this research was to prepare and optimize calcium carbonate (CaCO3) nanoparticles as carriers for gentamicin sulfate. A chemical precipitation method was used to prepare the gentamicin sulfate-loaded CaCO3 nanoparticles. A 3-factor, 3-level Box-Behnken design was used for the optimization procedure, with the molar ratio of CaCl2: Na2CO3 (X1), the concentration of drug (X2), and the speed of homogenization (X3) as the independent variables. The particle size and entrapment efficiency were considered as response variables. Mathematical equations and response surface plots were used, along with the counter plots, to relate the dependent and independent variables. The results indicated that the speed of homogenization was the main variable contributing to particle size and entrapment efficiency. The combined effect of all three independent variables was also evaluated. Using the response optimization design, the optimized Xl-X3 levels were predicted. An optimized formulation was then prepared according to these levels, resulting in a particle size of 80.23 nm and an entrapment efficiency of 30.80%. It was concluded that the chemical precipitation technique, together with the Box-Behnken experimental design methodology, could be successfully used to optimize the formulation of drug-incorporated calcium carbonate nanoparticles.

Concentration gradient along the scala tympani after local application of gentamicin to the round window membrane.

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Plontke, Stefan K; Mynatt, Robert; Gill, Ruth M; Borgmann, Stefan; Salt, Alec N

2007-07-01

The distribution of gentamicin along the fluid spaces of the cochlea after local applications has never previously been demonstrated. Computer simulations have predicted that significant basal-apical concentration gradients might be expected, and histologic studies indicate that hair cell damage is greater at the base than at the apex after local gentamicin application. In the present study, gradients of gentamicin along the cochlea were measured. A recently developed method of sampling perilymph from the cochlear apex of guinea pigs was used in which the samples represent fluid originating from different regions along the scala tympani. Gentamicin concentration was determined in sequential apical samples that were taken after up to 3 hours of local application to the round window niche. Substantial gradients of gentamicin along the length of the scala tympani were demonstrated and quantified, averaging more than 4,000 times greater concentration at the base compared with the apex at the time of sampling. Peak concentrations and gradients for gentamicin varied considerably between animals, likely resulting from variations in round window membrane permeability and rates of perilymph flow. The large gradients for gentamicin demonstrated here in guinea pigs account for how it is possible to suppress vestibular function in some patients with a local application of gentamicin without damaging auditory function. Variations in round window membrane permeability and in perilymph flow could account for why hearing losses are observed in some patients.

Concentration gradient along scala tympani following the local application of gentamicin to the round window membrane

Science.gov (United States)

Plontke, Stefan K.; Mynatt, Robert; Gill, Ruth M.; Borgmann, Stefan; Salt, Alec N.

2008-01-01

Objectives The distribution of gentamicin along the fluid spaces of the cochlea following local applications has never previously been demonstrated. Computer simulations have predicted that significant basal-apical concentration gradients might be expected and histological studies indicate that hair cell damage is greater at the base than at the apex following local gentamicin application. In the present study, gradients of gentamicin along the cochlea were measured. Methods A recently-developed method of sampling perilymph from the cochlear apex of guinea pigs was used, in which the samples represent fluid originating from different regions along scala tympani. Gentamicin concentration was determined in sequential apical samples which were taken following up to three hours of local application to the round window niche. Results Substantial gradients of gentamicin along the length of scala tympani were demonstrated and quantified, averaging more than 4000 times greater concentration at the base compared to the apex at the time of sampling. Peak concentrations and gradients for gentamicin varied considerably between animals, likely resulting from variations in round window membrane permeability and rates of perilymph flow. Conclusions The large gradients for gentamicin demonstrated here in guinea pigs account for how it is possible to suppress vestibular function in some patients with a local application of gentamicin without damaging auditory function. Variations in round window membrane permeability and in perilymph flow could account for why hearing losses are observed in some patients. PMID:17603318

Role of somatostatin receptor-2 in gentamicin-induced auditory hair cell loss in the Mammalian inner ear.

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Yves Brand

Full Text Available Hair cells and spiral ganglion neurons of the mammalian auditory system do not regenerate, and their loss leads to irreversible hearing loss. Aminoglycosides induce auditory hair cell death in vitro, and evidence suggests that phosphatidylinositol-3-kinase/Akt signaling opposes gentamicin toxicity via its downstream target, the protein kinase Akt. We previously demonstrated that somatostatin-a peptide with hormone/neurotransmitter properties-can protect hair cells from gentamicin-induced hair cell death in vitro, and that somatostatin receptors are expressed in the mammalian inner ear. However, it remains unknown how this protective effect is mediated. In the present study, we show a highly significant protective effect of octreotide (a drug that mimics and is more potent than somatostatin on gentamicin-induced hair cell death, and increased Akt phosphorylation in octreotide-treated organ of Corti explants in vitro. Moreover, we demonstrate that somatostatin receptor-1 knockout mice overexpress somatostatin receptor-2 in the organ of Corti, and are less susceptible to gentamicin-induced hair cell loss than wild-type or somatostatin-1/somatostatin-2 double-knockout mice. Finally, we show that octreotide affects auditory hair cells, enhances spiral ganglion neurite number, and decreases spiral ganglion neurite length.

Antibiotic Susceptibility Pattern of Gram-positive Cocci Cultured from Patients in Three University Hospitals in Tehran, Iran during 2001-2005

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Aligholi Marzieh

2009-10-01

Full Text Available Bacterial resistance to antibiotics is a serious problem and is increasing in prevalence world-wide at an alarming rate. The antimicrobial susceptibility patterns of 1897 gram-positive bacterial Isolates were evaluated. The minimum inhibitory concentration (MIC of isolates which comprised Staphylococcus aureus (927 isolates, coagulase-negative staphylococci (CNS; 425 isolates, Enterococcus faecalis (320 isolates, Enterococcus faecium (157 isolates, and pneumococci (50 isolates collected from 3 teaching hospitals in Tehran were determined by agar dilution method according to Clinical and Laboratory Standards Institute (CLSI guidelines. The presence of mecA gene was investigated in methicillin-resistant staphylococci by PCR method and vanA and vanB genes were targeted in enterococcal isolates by Multiplex PCR method. The resistance rate to methicillin among S. aureus and CNS isolates were 33% and 49%, respectively. All S. aureus isolates were susceptible to vancomycin .The lowest rate of resistance in all S. aureus isolates was found for rifampicin (<4%. The vancomycin resistance rate in enterococci isolates was 11% which was more frequent among E. faecium (19% than E. faecalis (4%, all resistant isolates carrying vanA. High-level resistance to gentamicin and streptomycin, were detected in 47% and 87% of enterococcal isolates respectively. The rate of penicillin resistance in pneumococci was 3% and about 27% of isolates had reduced susceptibility to penicillin. The prevalence of erythromycin resistant among pneumococci was 58%. All pneumococcal isolates were susceptible to ceftriaxone, rifampicin and vancomycin. Our data highlight the importance of access to updated bacterial susceptibility data regarding commonly prescribed agents for clinicians in Iran.

The development of polymeric pellicles with gentamicine sulfate for therapeutic correction of cervical erosion (pseudoerosion

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T. M. Litvinenko

2014-08-01

Full Text Available Introduction.Cervical erosionsoccur in 12-15%gynaecological diseases. Erosion is a damage of epithelialmucous membrane or skin. Therapy of patients with cervical erosionsis based on selection of pathogeneticsubstantiative method of treatment. Bathes and irrigations with 20% protargol, alum, carbolic acid, potassium permanganate are used. But some authors admit the destructive influence of these procedures. Using of tampons with 10% sintomycine emulsion, cod liver oil, sea-buckthorn oil,kalanchoe sap, propolis, vagotil, cigerol, galantamine also doesn’t give desirable result. Recently polymeric pellicleswith antibacterial substances are widely used. The most perspective in this route are aminoglycoside antibiotics. That is why we chose gentamicine sulfate (broad-spectrum aminoglycoside antibiotic. The aim of study is the development of the optimal composition of vaginal pellicleswith gentamicine sulfate for gynaecological practice, scientifically substantiation of excipients: polymeric base and plasticizer. Results and discussion.Polymeric bases and plasticizers influence on gentamicine sulfate releasing from polimericpellicleshas been studied. Research on choice of optimal composition has been carried out by two-factor experiment plan. The next bases and plasticizers have been used: methylcellulose, sodium carboxymethylcellulose, soluble biopolymer, gelatin; glycerine, propylenglycol, polyethylene glycol, twin 80. Gentamicine sulfate content was 80 mg in one pellicle. Gentamicine sulfate releasing from polimericpellicleshas been investigated by the Kruvchinsky method, concentration of active substance has been detected after 45 min. As a result it has been established that base makes essential influence on the gentamicine sulfate releasing (Fexp.52,88>Ftabl. 3,9. The best plasticizer is glycerin and the most optimal base is gelatin. So the optimal composition for vaginal films has been chosen: Gentamicine sulfate0,08 g Glycerin0,7 g Gelatin0

EFSA (European Food Safety Authority) and ECDC (European Centre for Disease Prevention and Control), 2015. EU Summary Report on antimicrobial resistance in zoonotic and indicator bacteria from humans, animals and food in 2013

DEFF Research Database (Denmark)

Korsgaard, Helle Bisgaard

The antimicrobial resistance data on zoonotic and indicator bacteria in 2013, submitted by 28 EU MSs, were jointly analysed by EFSA and ECDC. Resistance in zoonotic Salmonella and Campylobacter species from humans, animals and food, and resistance in indicator Escherichia coli and enterococci...... from broilers and/or pigs in several MSs. Multi-resistance and co-resistance to critically important antimicrobials in both human and animal isolates were uncommon. A minority of isolates from animals belonging to a few Salmonella serovars (notably Kentucky and Infantis) had a high level of resistance......,as well as data on meticillin-resistant Staphylococcus aureus, in animals and food were addressed. ‘Microbiological’ resistance was assessed using epidemiological cut-off (ECOFF) values in animal and food isolates and, where possible, in human isolates. For human isolates interpreted based on clinical...

Gentamicin coating of plasma chemical oxidized titanium alloy prevents implant-related osteomyelitis in rats.

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Diefenbeck, M; Schrader, C; Gras, F; Mückley, T; Schmidt, J; Zankovych, S; Bossert, J; Jandt, K D; Völpel, A; Sigusch, B W; Schubert, H; Bischoff, S; Pfister, W; Edel, B; Faucon, M; Finger, U

2016-09-01

Implant related infection is one of the most feared and devastating complication associated with the use of orthopaedic implant devices. Development of anti-infective surfaces is the main strategy to prevent implant contamination, biofilm formation and implant related osteomyelitis. A second concern in orthopaedics is insufficient osseointegration of uncemented implant devices. Recently, we reported on a macroporous titanium-oxide surface (bioactive TiOB) which increases osseointegration and implant fixation. To combine enhanced osseointegration and antibacterial function, the TiOB surfaces were, in addition, modified with a gentamicin coating. A rat osteomyelitis model with bilateral placement of titanium alloy implants was employed to analyse the prophylactic effect of gentamicin-sodiumdodecylsulfate (SDS) and gentamicin-tannic acid coatings in vivo. 20 rats were randomly assigned to four groups: (A) titanium alloy; PBS inoculum (negative control), (B) titanium alloy, Staphylococcus aureus inoculum (positive control), (C) bioactive TiOB with gentamicin-SDS and (D) bioactive TiOB plus gentamicin-tannic acid coating. Contamination of implants, bacterial load of bone powder and radiographic as well as histological signs of implant-related osteomyelitis were evaluated after four weeks. Gentamicin-SDS coating prevented implant contamination in 10 of 10 tibiae and gentamicin-tannic acid coating in 9 of 10 tibiae (infection prophylaxis rate 100% and 90% of cases, respectively). In Group (D) one implant showed colonisation of bacteria (swab of entry point and roll-out test positive for S. aureus). The interobserver reliability showed no difference in the histologic and radiographic osteomyelitis scores. In both gentamicin coated groups, a significant reduction of the histological osteomyelitis score (geometric mean values: C = 0.111 ± 0.023; D = 0.056 ± 0.006) compared to the positive control group (B: 0.244 ± 0.015; p < 0.05) was observed. The

Occurrence of Escherichia coli and enterococci in Cladophora (Clorophyta) in nearshore water and beach sand of Lake Michigan

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Whitman, Richard L.; Shively, Dawn A.; Pawlik, Heather; Nevers, Meredith B.; Byappanahalli, Muruleedhara N.

2003-01-01

Each summer, the nuisance green alga Cladophora (mostly Cladophora glomerata) amasses along Lake Michigan beaches, creating nearshore anoxia and unsightly, malodorous mats that can attract problem animals and detract from visitor enjoyment. Traditionally, elevated counts of Escherichia coli are presumed to indicate the presence of sewage, mostly derived from nearby point sources. The relationship between fecal indicator bacteria and Cladophora remains essentially unstudied. This investigation describes the local and regional density of Escherichia coli and enterococci in Cladophora mats along beaches in the four states (Wisconsin, Illinois, Indiana, and Michigan) bordering Lake Michigan. Samples of Cladophora strands collected from 10 beaches (n = 41) were assayed for concentrations of E. coli and enterococci during the summer of 2002. Both E. coli and enterococci were ubiquitous (up to 97% occurrence), with overall log mean densities (± standard errors) of 5.3 (± 4.8) and 4.8 (± 4.5) per g (dry weight). E. coli and enterococci were strongly correlated in southern Lake Michigan beaches (P R2 = 0.73, n = 17) but not in northern beaches (P = 0.892, n = 16). Both E. coli and enterococci survived for over 6 months in sun-dried Cladophora mats stored at 4°C; the residual bacteria in the dried alga readily grew upon rehydration. These findings suggest that Cladophora amassing along the beaches of Lake Michigan may be an important environmental source of indicator bacteria and call into question the reliability of E. coli and enterococci as indicators of water quality for freshwater recreational beaches.

Pharmacokinetic modeling of gentamicin in treatment of infective endocarditis : Model development and validation of existing models

NARCIS (Netherlands)

Gomes, Anna; van der Wijk, Lars; Proost, Johannes H; Sinha, Bhanu; Touw, Daan J

2017-01-01

Gentamicin shows large variations in half-life and volume of distribution (Vd) within and between individuals. Thus, monitoring and accurately predicting serum levels are required to optimize effectiveness and minimize toxicity. Currently, two population pharmacokinetic models are applied for

Naringin ameliorates gentamicin-induced nephrotoxicity and associated mitochondrial dysfunction, apoptosis and inflammation in rats: Possible mechanism of nephroprotection

Energy Technology Data Exchange (ETDEWEB)

Sahu, Bidya Dhar [Medicinal Chemistry and Pharmacology Division, Indian Institute of Chemical Technology (IICT), Hyderabad 500 007 (India); Tatireddy, Srujana [National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad 500 037 (India); Koneru, Meghana [Medicinal Chemistry and Pharmacology Division, Indian Institute of Chemical Technology (IICT), Hyderabad 500 007 (India); Borkar, Roshan M. [National Centre for Mass Spectrometry, Indian Institute of Chemical Technology (IICT), Hyderabad 500 007 (India); Kumar, Jerald Mahesh [CSIR-Centre for Cellular and Molecular Biology (CCMB), Hyderabad 500 007 (India); Kuncha, Madhusudana [Medicinal Chemistry and Pharmacology Division, Indian Institute of Chemical Technology (IICT), Hyderabad 500 007 (India); Srinivas, R. [National Centre for Mass Spectrometry, Indian Institute of Chemical Technology (IICT), Hyderabad 500 007 (India); Shyam Sunder, R. [Faculty of Pharmacy, Osmania University, Hyderabad 500 007 (India); Sistla, Ramakrishna, E-mail: sistla@iict.res.in [Medicinal Chemistry and Pharmacology Division, Indian Institute of Chemical Technology (IICT), Hyderabad 500 007 (India)

2014-05-15

Gentamicin-induced nephrotoxicity has been well documented, although its underlying mechanisms and preventive strategies remain to be investigated. The present study was designed to investigate the protective effect of naringin, a bioflavonoid, on gentamicin-induced nephrotoxicity and to elucidate the potential mechanism. Serum specific renal function parameters (blood urea nitrogen and creatinine) and histopathology of kidney tissues were evaluated to assess the gentamicin-induced nephrotoxicity. Renal oxidative stress (lipid peroxidation, protein carbonylation, enzymatic and non-enzymatic antioxidants), inflammatory (NF-kB [p65], TNF-α, IL-6 and MPO) and apoptotic (caspase 3, caspase 9, Bax, Bcl-2, p53 and DNA fragmentation) markers were also evaluated. Significant decrease in mitochondrial NADH dehydrogenase, succinate dehydrogenase, cytochrome c oxidase and mitochondrial redox activity indicated the gentamicin-induced mitochondrial dysfunction. Naringin (100 mg/kg) treatment along with gentamicin restored the mitochondrial function and increased the renal endogenous antioxidant status. Gentamicin induced increased renal inflammatory cytokines (TNF-α and IL-6), nuclear protein expression of NF-κB (p65) and NF-κB-DNA binding activity and myeloperoxidase (MPO) activity were significantly decreased upon naringin treatment. In addition, naringin treatment significantly decreased the amount of cleaved caspase 3, Bax, and p53 protein expression and increased the Bcl-2 protein expression. Naringin treatment also ameliorated the extent of histologic injury and reduced inflammatory infiltration in renal tubules. U-HPLS-MS data revealed that naringin co-administration along with gentamicin did not alter the renal uptake and/or accumulation of gentamicin in kidney tissues. These findings suggest that naringin treatment attenuates renal dysfunction and structural damage through the reduction of oxidative stress, mitochondrial dysfunction, inflammation and apoptosis in

Pharmacokinetic modeling of gentamicin in treatment of infective endocarditis: Model development and validation of existing models

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van der Wijk, Lars; Proost, Johannes H.; Sinha, Bhanu; Touw, Daan J.

2017-01-01

Gentamicin shows large variations in half-life and volume of distribution (Vd) within and between individuals. Thus, monitoring and accurately predicting serum levels are required to optimize effectiveness and minimize toxicity. Currently, two population pharmacokinetic models are applied for predicting gentamicin doses in adults. For endocarditis patients the optimal model is unknown. We aimed at: 1) creating an optimal model for endocarditis patients; and 2) assessing whether the endocarditis and existing models can accurately predict serum levels. We performed a retrospective observational two-cohort study: one cohort to parameterize the endocarditis model by iterative two-stage Bayesian analysis, and a second cohort to validate and compare all three models. The Akaike Information Criterion and the weighted sum of squares of the residuals divided by the degrees of freedom were used to select the endocarditis model. Median Prediction Error (MDPE) and Median Absolute Prediction Error (MDAPE) were used to test all models with the validation dataset. We built the endocarditis model based on data from the modeling cohort (65 patients) with a fixed 0.277 L/h/70kg metabolic clearance, 0.698 (±0.358) renal clearance as fraction of creatinine clearance, and Vd 0.312 (±0.076) L/kg corrected lean body mass. External validation with data from 14 validation cohort patients showed a similar predictive power of the endocarditis model (MDPE -1.77%, MDAPE 4.68%) as compared to the intensive-care (MDPE -1.33%, MDAPE 4.37%) and standard (MDPE -0.90%, MDAPE 4.82%) models. All models acceptably predicted pharmacokinetic parameters for gentamicin in endocarditis patients. However, these patients appear to have an increased Vd, similar to intensive care patients. Vd mainly determines the height of peak serum levels, which in turn correlate with bactericidal activity. In order to maintain simplicity, we advise to use the existing intensive-care model in clinical practice to avoid

Pharmacokinetic modeling of gentamicin in treatment of infective endocarditis: Model development and validation of existing models.

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Anna Gomes

Full Text Available Gentamicin shows large variations in half-life and volume of distribution (Vd within and between individuals. Thus, monitoring and accurately predicting serum levels are required to optimize effectiveness and minimize toxicity. Currently, two population pharmacokinetic models are applied for predicting gentamicin doses in adults. For endocarditis patients the optimal model is unknown. We aimed at: 1 creating an optimal model for endocarditis patients; and 2 assessing whether the endocarditis and existing models can accurately predict serum levels. We performed a retrospective observational two-cohort study: one cohort to parameterize the endocarditis model by iterative two-stage Bayesian analysis, and a second cohort to validate and compare all three models. The Akaike Information Criterion and the weighted sum of squares of the residuals divided by the degrees of freedom were used to select the endocarditis model. Median Prediction Error (MDPE and Median Absolute Prediction Error (MDAPE were used to test all models with the validation dataset. We built the endocarditis model based on data from the modeling cohort (65 patients with a fixed 0.277 L/h/70kg metabolic clearance, 0.698 (±0.358 renal clearance as fraction of creatinine clearance, and Vd 0.312 (±0.076 L/kg corrected lean body mass. External validation with data from 14 validation cohort patients showed a similar predictive power of the endocarditis model (MDPE -1.77%, MDAPE 4.68% as compared to the intensive-care (MDPE -1.33%, MDAPE 4.37% and standard (MDPE -0.90%, MDAPE 4.82% models. All models acceptably predicted pharmacokinetic parameters for gentamicin in endocarditis patients. However, these patients appear to have an increased Vd, similar to intensive care patients. Vd mainly determines the height of peak serum levels, which in turn correlate with bactericidal activity. In order to maintain simplicity, we advise to use the existing intensive-care model in clinical practice to

Resistance patterns of bacterial isolates to antimicrobials from 3 hospitals in the United Arab Emirates

International Nuclear Information System (INIS)

AlDhaheri, Ahmed S; AlNiyadi, Mohammed S; AlDhaheri Ahmed D; Bastaki, Salim M

2009-01-01

To compare the resistance pattern of common bacterial pathogens to commonly used drugs. Information and statistics of antimicrobial resistance for 1994 and 2005 were collected from the 3 hospital microbiology laboratories in the United Arab Emirates. The resistance patterns of Staphylococcus aureus, Escherichia coli, Klebsiella spp, and Pseudomonas aeruginosa to several front-line drugs were estimated. All laboratories used automatic machines (Vitek 2), which identifies and determines minimum inhibitory concentrations simultaneously. Increased resistance was observed for Staphylococcus aureus, (n=315, 2005) to erythromycin (approximately 6 fold, Al-Ain Hospital only), cloxacillin (Al-Ain Hospital), and gentamicin (more than 3-10 folds in all hospitals). Increased penicillin resistance was not observed. For the common Gram-negative organisms, there was a high resistance to ampicillin, gentamicin, ceftriaxone, ciprofloxacin, and imipenem, which seemed to increase for Escherichia coli, (by 4.2-200%, n=305, 2005); however, there was very little resistance to imipenem (0.4%) in Tawam Hospital. Variable resistance patterns were obtained for Pseudomonas aeruginosa (n=316, 2005) and Klebsiella spp,(n=316, 2005) against aminoglycosides, cephalosporins, ciprofloxacin, and norfloxacin. Overall, there was an obvious increase in resistance of bacteria and the prevalence rate to a number of drugs from 1-120 folds during the 11-year period. (author)

K88 Fimbrial Adhesin Targeting of Microspheres Containing Gentamicin Made with Albumin Glycated with Lactose

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Andre-i Sarabia-Sainz

2015-09-01

Full Text Available The formulation and characterization of gentamicin-loaded microspheres as a delivery system targeting enterotoxigenic Escherichia coli K88 (E. coli K88 was investigated. Glycated albumin with lactose (BSA-glucose-β (4-1 galactose was used as the microsphere matrix (MS-Lac and gentamicin included as the transported antibiotic. The proposed target strategy was that exposed galactoses of MS-Lac could be specifically recognized by E. coli K88 adhesins, and the delivery of gentamicin would inhibit bacterial growth. Lactosylated microspheres (MS-Lac1, MS-Lac2 and MS-Lac3 were obtained using a water-in-oil emulsion, containing gentamicin, followed by crosslinking with different concentrations of glutaraldehyde. Electron microscopy displayed spherical particles with a mean size of 10–17 µm. In vitro release of gentamicin from MS-Lac was best fitted to a first order model, and the antibacterial activity of encapsulated and free gentamicin was comparable. MS-Lac treatments were recognized by plant galactose-specific lectins from Ricinus communis and Sophora japonica and by E. coli K88 adhesins. Results indicate MS-Lac1, produced with 4.2 mg/mL of crosslinker, as the best treatment and that lactosylated microsphere are promising platforms to obtain an active, targeted system against E. coli K88 infections.

The effect of antibiotic use on prevalence of nosocomial vancomycin-resistant enterococci- an ecologic study

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Cornelius Remschmidt

2017-09-01

Full Text Available Abstract Background Vancomycin-resistant enterococci (VRE are among the most common antimicrobial-resistant pathogens causing nosocomial infections. Although antibiotic use has been identified as a risk factor for VRE, it remains unclear which antimicrobial agents particularly facilitate VRE selection. Here, we assessed whether use of specific antimicrobial agents is independently associated with healthcare-associated (HA VRE rates in a university hospital setting in Berlin, Germany. Methods We conducted the study between January 2014 and December 2015 at the Charité-university hospital of Berlin, Germany. From the hospital pharmacy, we extracted data for all antibacterials for systemic use (anatomical therapeutic chemical (ATC-classification J01 and calculated ward specific antibiotic consumption in defined daily doses (DDDs per 100 patient-days (PD. We used the microbiology laboratory database to identify all patients with isolation of invasive or non-invasive VRE and calculated HA-VRE incidence as nosocomial VRE-cases per 100 patients and HA-VRE incidence density as nosocomial VRE-cases per 1000 PD. We defined VRE isolates as hospital-acquired if they were identified three days or later after hospital admission and otherwise as community-acquired (CA-VRE. We performed univariable and multivariable regression analyses to estimate the association of the frequency of HA-VRE per month with antibiotic use and other parameters such as length of stay, type of ward or presence of at least one CA-VRE on ward. In a second analysis, we considered only patients with VRE infections. Results We included data from 204,054 patients with 948,380 PD from 61 wards. Overall, 1430 VRE-cases were identified of which 409 (28.6% were considered hospital-acquired (HA. We found that carbapenem use in the current month and prior-month use of glycopeptides increased the risk for HA-VRE by 1% per 1 DDD/100 PD and 3% per 1 DDD/100 PD, respectively. However, when only VRE

Resistência a antimicrobianos de Escherichia coli isolada de dejetos suínos em esterqueiras Antibiotic-resistance of Escherichia coli isolates from stored pig slurry

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F.F.P. Silva

2008-06-01

Full Text Available The antimicrobial resistance of 96 Escherichia coli strains isolated from a stabilization pond system on a pig-breeding farm was evaluated. Strains were tested for their resistance against 14 antimicrobial using the agar diffusion method. E. coli strains showed resistance to tetracycline (82.3%, nalidixic acid (64%, ampicilin (41%, sulfamethoxazole/trimethoprin (36%, sulfonamide (34%, cloranphenicol (274%, ciprofloxacin (19%, cefaclor (16%, streptomicyn (7.3%, neomicyn (1%, amoxacilin/ clavulanic acid (1%, and amikacin (1%. No resistance was observed to gentamicin and tobramycin, and 37.5% of E. coli strains were resistant to four or more antimicrobials. The multiresistance pattern was found in strains isolated during all sampled period. Strains showed a high variability in the antimicrobial resistance pattern.

Efficacies of gentamicin-loaded magnetite block ionomer complexes against chronic Brucella melitensis infection

International Nuclear Information System (INIS)

Jain-Gupta, Neeta; Pothayee, Nipon; Pothayee, Nikorn; Tyler, Ronald; Caudell, David L.; Balasubramaniam, Sharavanan; Hu, Nan; Davis, Richey M.; Riffle, Judy S.; Sriranganathan, Nammalwar

2013-01-01

Anionic copolymers can enable intracellular delivery of cationic drugs which otherwise cannot cross cell membrane barriers. We tested the efficacy of gentamicin-loaded magnetite block ionomer complexes (MBICs) against intracellular Brucella melitensis. Anionic block copolymers were used to coat nanomagnetite through adsorption of a portion of anions on the particle surfaces, then the remaining anions were complexed with 30–32 weight percentage of gentamicin. The zeta potential changed from −39 to −13 mV after encapsulation of the drug with complementary charge. The gentamicin-loaded MBICs had intensity average hydrodynamic diameters of 62 nm, while the polymer-coated nanomagnetite particles without drug were 34 nm in size. No toxicity as measured by a MTS assay was observed upon incubation of the MBICs with J774A.1 murine macrophage-like cells. Confocal microscopic images showed that the MBICs were taken up by the macrophages and distributed in the cell cytoplasm and endosomal/lysosomal compartments. Upon treatment with gentamicin-loaded MBICs (3.5 Log 10 ), B. melitensis-infected macrophages showed significantly higher clearance of Brucella compared to the treatment with free g (0.9 Log 10 ). Compared to doxycycline alone, a combination of doxycycline and gentamicin (either free or encapsulated in MBICs) showed significantly higher clearance of B.melitensis from chronically infected mice. Histopathological examination of kidneys from the MBICs-treated mice revealed multifocal infiltration of macrophages containing intracytoplasmic iron (MBICs) in peri-renal adipose. Although MBICs showed similar efficacy as free gentamicin against Brucella in mice, our strategy presents an effective way to deliver higher loads of drugs intracellularly and ability to study the bio-distribution of drug carriers

Efficacies of gentamicin-loaded magnetite block ionomer complexes against chronic Brucella melitensis infection

Energy Technology Data Exchange (ETDEWEB)

Jain-Gupta, Neeta [Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Department of Biomedical Sciences and Pathobiology (United States); Pothayee, Nipon; Pothayee, Nikorn [Virginia Polytechnic Institute and State University, Macromolecules and Interfaces Institute (United States); Tyler, Ronald; Caudell, David L. [Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Department of Biomedical Sciences and Pathobiology (United States); Balasubramaniam, Sharavanan; Hu, Nan; Davis, Richey M.; Riffle, Judy S. [Virginia Polytechnic Institute and State University, Macromolecules and Interfaces Institute (United States); Sriranganathan, Nammalwar, E-mail: nathans@vt.edu [Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Department of Biomedical Sciences and Pathobiology (United States)

2013-11-15

Anionic copolymers can enable intracellular delivery of cationic drugs which otherwise cannot cross cell membrane barriers. We tested the efficacy of gentamicin-loaded magnetite block ionomer complexes (MBICs) against intracellular Brucella melitensis. Anionic block copolymers were used to coat nanomagnetite through adsorption of a portion of anions on the particle surfaces, then the remaining anions were complexed with 30–32 weight percentage of gentamicin. The zeta potential changed from −39 to −13 mV after encapsulation of the drug with complementary charge. The gentamicin-loaded MBICs had intensity average hydrodynamic diameters of 62 nm, while the polymer-coated nanomagnetite particles without drug were 34 nm in size. No toxicity as measured by a MTS assay was observed upon incubation of the MBICs with J774A.1 murine macrophage-like cells. Confocal microscopic images showed that the MBICs were taken up by the macrophages and distributed in the cell cytoplasm and endosomal/lysosomal compartments. Upon treatment with gentamicin-loaded MBICs (3.5 Log{sub 10}), B. melitensis-infected macrophages showed significantly higher clearance of Brucella compared to the treatment with free g (0.9 Log{sub 10}). Compared to doxycycline alone, a combination of doxycycline and gentamicin (either free or encapsulated in MBICs) showed significantly higher clearance of B.melitensis from chronically infected mice. Histopathological examination of kidneys from the MBICs-treated mice revealed multifocal infiltration of macrophages containing intracytoplasmic iron (MBICs) in peri-renal adipose. Although MBICs showed similar efficacy as free gentamicin against Brucella in mice, our strategy presents an effective way to deliver higher loads of drugs intracellularly and ability to study the bio-distribution of drug carriers.

Efficacies of gentamicin-loaded magnetite block ionomer complexes against chronic Brucella melitensis infection

Science.gov (United States)

Jain-Gupta, Neeta; Pothayee, Nipon; Pothayee, Nikorn; Tyler, Ronald; Caudell, David L.; Balasubramaniam, Sharavanan; Hu, Nan; Davis, Richey M.; Riffle, Judy S.; Sriranganathan, Nammalwar

2013-11-01

Anionic copolymers can enable intracellular delivery of cationic drugs which otherwise cannot cross cell membrane barriers. We tested the efficacy of gentamicin-loaded magnetite block ionomer complexes (MBICs) against intracellular Brucella melitensis. Anionic block copolymers were used to coat nanomagnetite through adsorption of a portion of anions on the particle surfaces, then the remaining anions were complexed with 30-32 weight percentage of gentamicin. The zeta potential changed from -39 to -13 mV after encapsulation of the drug with complementary charge. The gentamicin-loaded MBICs had intensity average hydrodynamic diameters of 62 nm, while the polymer-coated nanomagnetite particles without drug were 34 nm in size. No toxicity as measured by a MTS assay was observed upon incubation of the MBICs with J774A.1 murine macrophage-like cells. Confocal microscopic images showed that the MBICs were taken up by the macrophages and distributed in the cell cytoplasm and endosomal/lysosomal compartments. Upon treatment with gentamicin-loaded MBICs (3.5 Log10), B. melitensis-infected macrophages showed significantly higher clearance of Brucella compared to the treatment with free g (0.9 Log10). Compared to doxycycline alone, a combination of doxycycline and gentamicin (either free or encapsulated in MBICs) showed significantly higher clearance of B. melitensis from chronically infected mice. Histopathological examination of kidneys from the MBICs-treated mice revealed multifocal infiltration of macrophages containing intracytoplasmic iron (MBICs) in peri-renal adipose. Although MBICs showed similar efficacy as free gentamicin against Brucella in mice, our strategy presents an effective way to deliver higher loads of drugs intracellularly and ability to study the bio-distribution of drug carriers.

Protective role of ginseng against gentamicin induced changes in kidney of albino mice

International Nuclear Information System (INIS)

Hafeez, M.; Saeed, F.

2011-01-01

Background: Use of gentamicin is now limited due to its toxic effects, mainly on kidney and vestibular system. Herbal products including ginseng has been reported to possess protective effects against drugs induced nephrotoxicity in experimental animals. The current investigation was designed to evaluate the effects of ginseng on gentamicin induced nephrotoxicity. Methods: Eighteen male albino mice of 6-8 weeks age, were divided into 3 groups. Group-A served as control and was given normal mouse diet; Group-B was given 80 mg/Kg/day of gentamicin intraperitoneally dissolved in 1 ml of distilled water for fifteen days. Group-C was given 80 mg/Kg/day of gentamicin intraperitoneally dissolved in 1 ml of distilled water along with 100 mg/Kg/day of ginseng orally dissolved in 1 ml of distilled water, also for fifteen days. At the end of the experiment, blood was drawn from each animal by cardiac puncture for renal function tests. Each animal was then sacrificed and kidneys removed for routine histological studies. Results: In group B, weight of the animals and kidneys decreased and there was significant increase in mean serum urea, creatinine and intraluminal diameter (p<0.001) of proximal convoluted tubules as compared to the controls (group-A). Moderate to severe necrotic and degenerative changes in proximal convoluted tubules were seen in this group. When the Ginseng and gentamicin were given together (group-C), a statistically significant improvement in the mean body and kidney weight along with improvement in renal function tests and tubular diameter were seen (p<0.001). Conclusion: It appears that Ginseng has some protective role against gentamicin induced nephrotoxicity. (author)

Does antifouling paint select for antibiotic resistance?

Science.gov (United States)

Flach, Carl-Fredrik; Pal, Chandan; Svensson, Carl Johan; Kristiansson, Erik; Östman, Marcus; Bengtsson-Palme, Johan; Tysklind, Mats; Larsson, D G Joakim

2017-07-15

There is concern that heavy metals and biocides contribute to the development of antibiotic resistance via co-selection. Most antifouling paints contain high amounts of such substances, which risks turning painted ship hulls into highly mobile refuges and breeding grounds for antibiotic-resistant bacteria. The objectives of this study were to start investigate if heavy-metal based antifouling paints can pose a risk for co-selection of antibiotic-resistant bacteria and, if so, identify the underlying genetic basis. Plastic panels with one side painted with copper and zinc-containing antifouling paint were submerged in a Swedish marina and biofilms from both sides of the panels were harvested after 2.5-4weeks. DNA was isolated from the biofilms and subjected to metagenomic sequencing. Biofilm bacteria were cultured on marine agar supplemented with tetracycline, gentamicin, copper sulfate or zinc sulfate. Biofilm communities from painted surfaces displayed lower taxonomic diversity and enrichment of Gammaproteobacteria. Bacteria from these communities showed increased resistance to both heavy metals and tetracycline but not to gentamicin. Significantly higher abundance of metal and biocide resistance genes was observed, whereas mobile antibiotic resistance genes were not enriched in these communities. In contrast, we found an enrichment of chromosomal RND efflux system genes, including such with documented ability to confer decreased susceptibility to both antibiotics and biocides/heavy metals. This was paralleled by increased abundances of integron-associated integrase and ISCR transposase genes. The results show that the heavy metal-based antifouling paint exerts a strong selection pressure on marine bacterial communities and can co-select for certain antibiotic-resistant bacteria, likely by favoring species and strains carrying genes that provide cross-resistance. Although this does not indicate an immediate risk for promotion of mobile antibiotic resistance, the

Multiple drug resistance patterns in various phylogenetic groups of uropathogenic E.coli isolated from Faisalabad region of Pakistan

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Saira Bashir

2011-12-01

Full Text Available The objective of this work was the phylogenetic characterization of local clinical isolates of uropathogenic E. coli with respect to drug resistance. A total of 59 uropathogenic E. coli responsible for community acquired urinary tract infections were included in this study. A triplex PCR was employed to segregate each isolate into four different phylogenetic groups (A, B1, B2 and D. Drug resistance was evaluated by disc diffusion method. The drugs used were ampicillin, aztreonam, cefixime, cefoperazone, ceftriaxone, cephradine among β-lactam group; amikacin, gentamicin, and streptomycin among aminoglycosides; nalidixic acid and ciprofloxacin from quinolones; trimethoprim-sulfomethoxazole, and tetracycline. Among 59 uropathogenic E. coli isolates majority belonged to phylogenetic group B2 (50% where as 19% each belonged to groups A and B1, and 12% to group D. All the isolates were multiple drug resistant (MDR. Most effective drugs against Group A, B1, and B2 were gentamicin, amikacin and cefixime; ceftriaxone and quinolones; and ceftriaxone and amikacin, respectively. Group D isolates were found to be highly resistant to all drugs. Our results have shown emergence of MDR isolates among uropathogenic E. coli with dominance of phylogenetic group B2. However, it was found that group D isolates were though less frequent, more drug resistant as compared with group B2. Groups A and B1 were relatively uncommon. Amikacin, ceftriaxone and gentamicin were the most effective drugs in general.

Soluble Urokinase Plasminogen Activator Receptor Levels in Tuberculosis Patients at High Risk for Multidrug Resistance

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Tri Yudani Mardining Raras

2012-01-01

Full Text Available The soluble urokinase plasminogen activator receptor (suPAR has been shown to be a strong prognostic biomarker for tuberculosis (TB. In the present study, the profiles of plasma suPAR levels in pulmonary TB patients at high risk for multidrug resistance were analyzed and compared with those in multidrug resistant (MDR-TB patients. Forty patients were prospectively included, consisting of 10 MDR-TB patients and 30 TB patients at high risk for MDR, underwent clinical assesment. Plasma suPAR levels were measured using ELISA (SUPARnostic, Denmark and bacterial cultures were performed in addition to drug susceptibility tests. All patients of suspected MDR-TB group demonstrated significantly higher suPAR levels compared with the healthy TB-negative group (1.79 ng/mL. Among the three groups at high risk for MDR-TB, only the relapse group (7.87 ng/mL demonstrated suPAR levels comparable with those of MDR-TB patients (7.67 ng/mL. suPAR levels in the two-month negative acid-fast bacilli conversion group (9.29 ng/mL were higher than positive control, whereas levels in the group consisting of therapy failure patients (5.32 ng/mL were lower. Our results strongly suggest that suPAR levels enable rapid screening of suspected MDR-TB patients, but cannot differentiate between groups.

Antimicrobial resistance in faecal samples from buffalo, wildebeest and zebra grazing together with and without cattle in Tanzania.

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Katakweba, A A S; Møller, K S; Muumba, J; Muhairwa, A P; Damborg, P; Rosenkrantz, J T; Minga, U M; Mtambo, M M A; Olsen, J E

2015-04-01

The aim of this study was to determine whether the practice of co-grazing with cattle and wild life constitutes a risk of transmission of antibiotic resistant bacteria to wild ungulates. Faecal samples were collected from buffalo (n = 35), wildebeest (n = 40), zebra (n = 40) and cattle (N = 20) from Mikumi National Park, Tanzania (MNP), where cattle is prohibited and from Ngorongoro Conservation Area (NCA) where co-grazing is practiced. The number of coliforms and enterococci resistant to selected antibiotics was determined. Wild life generally harboured higher number of resistant Escherichia coli and Enterococci than cattle, but with no general influence in wild life of co-grazing with cattle. Vancomycin-resistant Enterococci were detected in wild life samples, and E. coli resistant to cefotaxime and enrofloxacin were observed among isolates from all wild life, but not from cattle. Culture independent estimates of the number of sulII gene copies obtained by qPCR did not differ between wild life from the two sample sites, while tetW was significantly higher in samples from MPN than from NCA. Antibiotic resistant bacteria were not more frequently found in ungulates grazing together with cattle than ungulates without this interaction. This study did not indicate that transmission of antibiotic resistant bacteria is a frequent event following co-grazing of wild life and cattle. © 2014 The Society for Applied Microbiology.

Molecular characterization of vanA-containing Enterococcus from migratory birds: song thrush (Turdus philomelos

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Nuno Silva

2012-09-01

Full Text Available Vancomycin-resistant enterococci (VRE were detected in two faecal samples (1.3% of song thrush in Portugal. vanA isolates showed high level vancomycin/teicoplanin resistance, as well as resistance to ciprofloxacin, quinupristin-dalfopristin and cloranfenicol. Thrush can be a reservoir of VRE and transmit these resistant bacteria to other animals including humans.

Occurrence of Escherichia coli and Enterococci in Cladophora (Chlorophyta) in Nearshore Water and Beach Sand of Lake Michigan†

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Whitman, Richard L.; Shively, Dawn A.; Pawlik, Heather; Nevers, Meredith B.; Byappanahalli, Muruleedhara N.

2003-01-01

Each summer, the nuisance green alga Cladophora (mostly Cladophora glomerata) amasses along Lake Michigan beaches, creating nearshore anoxia and unsightly, malodorous mats that can attract problem animals and detract from visitor enjoyment. Traditionally, elevated counts of Escherichia coli are presumed to indicate the presence of sewage, mostly derived from nearby point sources. The relationship between fecal indicator bacteria and Cladophora remains essentially unstudied. This investigation describes the local and regional density of Escherichia coli and enterococci in Cladophora mats along beaches in the four states (Wisconsin, Illinois, Indiana, and Michigan) bordering Lake Michigan. Samples of Cladophora strands collected from 10 beaches (n = 41) were assayed for concentrations of E. coli and enterococci during the summer of 2002. Both E. coli and enterococci were ubiquitous (up to 97% occurrence), with overall log mean densities (± standard errors) of 5.3 (± 4.8) and 4.8 (± 4.5) per g (dry weight). E. coli and enterococci were strongly correlated in southern Lake Michigan beaches (P Cladophora mats stored at 4°C; the residual bacteria in the dried alga readily grew upon rehydration. These findings suggest that Cladophora amassing along the beaches of Lake Michigan may be an important environmental source of indicator bacteria and call into question the reliability of E. coli and enterococci as indicators of water quality for freshwater recreational beaches. PMID:12902262

Occurrence of Escherichia coli and enterococci in Cladophora (Chlorophyta) in nearshore water and beach sand of Lake Michigan.

Science.gov (United States)

Whitman, Richard L; Shively, Dawn A; Pawlik, Heather; Nevers, Meredith B; Byappanahalli, Muruleedhara N

2003-08-01

Each summer, the nuisance green alga Cladophora (mostly Cladophora glomerata) amasses along Lake Michigan beaches, creating nearshore anoxia and unsightly, malodorous mats that can attract problem animals and detract from visitor enjoyment. Traditionally, elevated counts of Escherichia coli are presumed to indicate the presence of sewage, mostly derived from nearby point sources. The relationship between fecal indicator bacteria and Cladophora remains essentially unstudied. This investigation describes the local and regional density of Escherichia coli and enterococci in Cladophora mats along beaches in the four states (Wisconsin, Illinois, Indiana, and Michigan) bordering Lake Michigan. Samples of Cladophora strands collected from 10 beaches (n = 41) were assayed for concentrations of E. coli and enterococci during the summer of 2002. Both E. coli and enterococci were ubiquitous (up to 97% occurrence), with overall log mean densities (+/- standard errors) of 5.3 (+/- 4.8) and 4.8 (+/- 4.5) per g (dry weight). E. coli and enterococci were strongly correlated in southern Lake Michigan beaches (P Cladophora mats stored at 4 degrees C; the residual bacteria in the dried alga readily grew upon rehydration. These findings suggest that Cladophora amassing along the beaches of Lake Michigan may be an important environmental source of indicator bacteria and call into question the reliability of E. coli and enterococci as indicators of water quality for freshwater recreational beaches.

Antibiotic resistance and resistance genes in Escherichia coli from poultry farms, southwest Nigeria

DEFF Research Database (Denmark)

Adelowo, Olawale O.; Fagade, Obasola E.; Agersø, Yvonne

2014-01-01

%, ampicillin 36%, spectinomycin 28%, nalidixic acid 25%, chloramphenicol 22%, neomycin 14%, gentamicin 8%, amoxicillin-clavulanate, ceftiofur, cefotaxime, colistin, florfenicol and apramycin 0%. Resistance genes found among the isolates include bla-TEM (85%), sul2 (67%), sul3 (17%), aadA (65%), strA (70%), str...

Antimicrobial Resistance Percentages of Salmonella and Shigella in Seafood Imported to Jordan: Higher Percentages and More Diverse Profiles in Shigella.

Science.gov (United States)

Obaidat, Mohammad M; Bani Salman, Alaa E

2017-03-01

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

Relationship and variation of qPCR and culturable enterococci estimates in ambient surface waters are predictable

Science.gov (United States)

Whitman, Richard L.; Ge, Zhongfu; Nevers, Meredith B.; Boehm, Alexandria B.; Chern, Eunice C.; Haugland, Richard A.; Lukasik, Ashley M.; Molina, Marirosa; Przybyla-Kelly, Kasia; Shively, Dawn A.; White, Emily M.; Zepp, Richard G.; Byappanahalli, Muruleedhara N.

2010-01-01

The quantitative polymerase chain reaction (qPCR) method provides rapid estimates of fecal indicator bacteria densities that have been indicated to be useful in the assessment of water quality. Primarily because this method provides faster results than standard culture-based methods, the U.S. Environmental Protection Agency is currently considering its use as a basis for revised ambient water quality criteria. In anticipation of this possibility, we sought to examine the relationship between qPCR-based and culture-based estimates of enterococci in surface waters. Using data from several research groups, we compared enterococci estimates by the two methods in water samples collected from 37 sites across the United States. A consistent linear pattern in the relationship between cell equivalents (CCE), based on the qPCR method, and colony-forming units (CFU), based on the traditional culturable method, was significant (P 10CFU > 2.0/100 mL) while uncertainty increases at lower CFU values. It was further noted that the relative error in replicated qPCR estimates was generally higher than that in replicated culture counts even at relatively high target levels, suggesting a greater need for replicated analyses in the qPCR method to reduce relative error. Further studies evaluating the relationship between culture and qPCR should take into account analytical uncertainty as well as potential differences in results of these methods that may arise from sample variability, different sources of pollution, and environmental factors.

Thymus morphometry of New Zealand White Rabbits treated with gentamicin

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Matheus Henrique Magalhães Silva

2010-09-01

Full Text Available The aim of this study was to evaluate the morphometry of cortical and medullary thymic lobes individualized by determination of area (μm2, perimeter (μm, maximum and minimum diameter (μm and shape factor in New Zealand White rabbits. The spleens of ten rabbits treated with gentamicin and ten control rabbits (males and females were histologically processed. The gentamicin dosage and the time of administration of this aminoglicoside were according to therapeutic recommendation. This antibiotic did not cause any alteration in the morphometry of the spleen, and it seemed not to be an immunosuppressive drug.

Thymus morphometry of New Zealand White Rabbits treated with gentamicin

Directory of Open Access Journals (Sweden)

Matheus Henrique Magalhães Silva

2010-01-01

Full Text Available The aim of this study was to evaluate the morphometry of cortical and medullary thymic lobes individualized by determination of area (µm2, perimeter (µm, maximum and minimum diameter (µm and shape factor in New Zealand White rabbits. The spleens of ten rabbits treated with gentamicin and ten control rabbits (males and females were histologically processed. The gentamicin dosage and the time of administration of this aminoglicoside were according to therapeutic recommendation. This antibiotic did not cause any alteration in the morphometry of the spleen, and it seemed not to be an immunosuppressive drug.

Analysis of gyrA and parC mutations in enterococci from environmental samples with reduced susceptibility to ciprofloxacin

DEFF Research Database (Denmark)

Petersen, A.; Jensen, Lars Bogø

2004-01-01

The quinolone resistance determining regions of gyrA and parC in four species of enterococci from environmental samples with reduced susceptibility to ciprofloxacin were sequenced. The nucleotide sequence variations of parC could be related to the different enterococcal species. Mutations...... in Enterococcus faecalis and Enterococcus faecium related to reduced susceptibility were identical to mutations detected in E jaecalis and E. faecium of clinical origin. A minimal inhibitory concentration of 8 mug ml(-1) to ciprofloxacin was not associated with any mutations in the gyrA and parC gene...... of Enterococcus casseliflavus and Enterococcus gallinarum. These two species may be intrinsically less susceptible to ciprofloxacin....

Instrumental characterization of the smectite clay–gentamicin hybrids

Indian Academy of Sciences (India)

use of conventional drugs may lead to fluctuations whereby drug concentrations in ... ence of smectite, as well as determination of the capacity of gentamicin to fill ... the pharmaceutical and cosmetic industries manufactured by. R.T. Vanderbilt ...

Multiwall carbon nanotubes chemically modified carbon paste electrodes for determination of gentamicin sulfate in pharmaceutical preparations and biological fluids.

Science.gov (United States)

Khalil, M M; Abed El-Aziz, G M

2016-02-01

This article focused on the construction and characteristics of novel and sensitive gentamicin carbon paste electrodes which are based on the incorporation of multiwall carbon nanotubes (MWCNTs) which improve the characteristics of the electrodes. The electrodes were constructed based on gentamicin-phosphotungstate (GNS-PTA) called CPE1, gentamicin-phosphomolybdate (GNS-PMA) called CPE2, GNS-PTA+ MWMCNTs called MWCPE1, and GNS-PMA+ MWMCNTs called MWCPE2. The constructed electrodes, at optimum paste composition, exhibited good Nernstian response for determination of gentamicin sulfate (GNS) over a linear concentration range from 2.5×10(-6) to 1×10(-2), 3.0×10(-6) to 1×10(-2), 4.9×10(-7) to 1×10(-2) and 5.0×10(-7) to 1×10(-2)molL(-1), with lower detection limit 1×10(-6), 1×10(-6), 1.9×10(-7) and 2.2×10(-7)molL(-1), and with slope values of 29.0±0.4, 29.2±0.7, 31.2±0.5 and 31.0±0.6mV/decade for CPE1, CPE2, MWCPE1 and MWCPE2, respectively. The response of electrodes is not affected by pH in the range 3-8 for CPE1 and CPE2 and in the range 2.5-8.5 for MWCPE1 and MWCPE2. The results showed fast dynamic response time (about 8-5s) and long lifetime (more than 2months) for all electrodes. The sensors showed high selectivity for gentamicin sulfate (GNS) with respect to a large number of interfering species. The constructed electrodes were successfully applied for determination of GNS in pure form, its pharmaceutical preparations and biological fluids using standard addition and potentiometric titration methods with high accuracy and precision. Published by Elsevier B.V.

Surface roughness, porosity and wettability of gentamicin-loaded bone cements and their antibiotic release

NARCIS (Netherlands)

van de Belt, H; Neut, D; Uges, DRA; Schenk, W; van Horn, [No Value; van der Mei, HC; Busscher, HJ

2000-01-01

In this study, the release of gentamicin as a function of time was measured for six different gentamicin-loaded bone cements and related with the surface roughness, porosity and wettability of the cements. Initial release rates varied little between the six bone cements (CMW1, CMW3, CMW Endurance,

Antibiotic Resistance of Diverse Bacteria from Aquaculture in Borneo

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M. M. Kathleen

2016-01-01

Full Text Available The administration of antimicrobials in aquaculture provides a selective pressure creating a reservoir of multiple resistant bacteria in the cultured fish and shrimps as well as the aquaculture environment. The objective of this study was to determine the extent of antibiotic resistance in aquaculture products and aquaculture’s surrounding environment in Sarawak, Malaysian Borneo. Ninety-four identified bacterial isolates constituted of 17 genera were isolated from sediment, water, and cultured organisms (fish and shrimp in selected aquaculture farms. These isolates were tested for their antibiotic resistance against 22 antibiotics from several groups using the disk diffusion method. The results show that the highest resistance was observed towards streptomycin (85%, n=20, while the lowest resistance was towards gentamicin (1.1%, n=90. The multiple antibiotic resistant (MAR index of the isolates tested ranged between 0 and 0.63. It was suggested that isolates with MAR index > 0.2 were recovered from sources with high risk of antibiotic resistant contamination. This study revealed low level of antibiotic resistance in the aquaculture bacterial isolates except for streptomycin and ampicillin (>50% resistance, n=94 which have been used in the aquaculture industry for several decades. Antibiotic resistant patterns should be continuously monitored to predict the emergence and widespread of MAR. Effective action is needed to keep the new resistance from further developing and spreading.

Discontinuation of peri-operative gentamicin use for indwelling urinary catheter manipulation in orthopaedic surgery.

Science.gov (United States)

Bond, Stuart E; Boutlis, Craig S; Jansen, Stuart G; Miyakis, Spiros

2017-11-01

Gentamicin has historically been used prior to insertion and removal of indwelling urinary catheters (IDCs) around elective joint replacement surgery to prevent infection; however, this indication is not recognized in the Australian Therapeutic Guidelines: Antibiotic and the paradigm for safe use of gentamicin has shifted. The antimicrobial stewardship team of a 500 bed tertiary regional hospital performed a retrospective clinical study of gentamicin IDC prophylaxis around total hip and knee arthroplasties. Results were presented to the orthopaedic surgeons. A literature review identified no guidelines to support gentamicin prophylaxis and only a very low risk of bacteraemia associated with IDC insertion/removal in patients with established bacteriuria. Consensus was reached with the surgeons to discontinue this practice. Subsequent prospective data collection was commenced to determine effectiveness, with weekly feedback to the Department Head of Orthopaedics. Data from 137 operations pre-intervention (6 months) were compared with 205 operations post-intervention (12 months). The median patient age was 72 years in both groups. Following the intervention, reductions in gentamicin use were demonstrated for IDC insertion (59/137 (42%) to 4/205 (2%), P < 0.01) and removal (39/137 (28%) to 6/205 (3%), P < 0.01). No gentamicin use was observed during the final 40 weeks of the post-intervention period. There were no significant differences between the groups for pre-operative bacteriuria, surgical site infections or acute kidney injury. A collaborative approach using quality improvement methodology can lead to an evidence-based reappraisal of established practice. Regular rolling audits and timely feedback were useful in sustaining change. © 2016 Royal Australasian College of Surgeons.

Old and New Glycopeptide Antibiotics: Action and Resistance

OpenAIRE

Binda, Elisa; Marinelli, Flavia; Marcone, Giorgia Letizia

2014-01-01

Glycopeptides are considered antibiotics of last resort for the treatment of life-threatening infections caused by relevant Gram-positive human pathogens, such as Staphylococcus aureus, Enterococcus spp. and Clostridium difficile. The emergence of glycopeptide-resistant clinical isolates, first among enterococci and then in staphylococci, has prompted research for second generation glycopeptides and a flurry of activity aimed at understanding resistance mechanisms and their evolution. Glycop...

Camel Milk Beneficial Effects on Treating Gentamicin Induced Alterations in Rats

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Abdulrahman K. Al-Asmari

2014-01-01

Full Text Available The potential effect of camel milk (CM against gentamicin (GM induced biochemical changes in the rat serum was evaluated. Four groups of six albino rats were used for control, CM fed, injected with GM(i.p., and then fed and injected with GM. The results showed that the administration of GM significantly altered the levels of aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP, and lactate dehydrogenase (LDH activity in rat serum. CM restored these parameters to almost their normal range in group IV. Additionally, the present study showed that injection of rats with gentamicin caused an increase in malondialdehyde (MDA and myeloperoxidase (MPO activity while the antioxidant enzymes like superoxide dismutase (SOD and glutathione s-transferase (GST activity decreased significantly (P≤0.05. Administration of CM significantly (P≤0.05 inhibited the formation of MDA and activity of MPO and upregulated the antioxidant enzymes (SOD and GST activity. The overall findings of this study demonstrated that pretreatment with CM gave protection against GM induced hepatic damage possibly by inhibiting oxidative stress and inflammation, and hence camel milk can be identified as a new therapeutic agent.

Identification and antimicrobial resistance of microflora colonizing feral pig (Sus scrofa of Brazilian Pantanal

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SS Lessa

2011-06-01

Full Text Available Antimicrobial resistance of bacteria is a worldwide problem affecting wild life by living with resistant bacteria in the environment. This study presents a discussion of outside factors environment on microflora of feral pigs (Sus scrofa from Brazilian Pantanal. Animals had samples collected from six different body sites coming from two separated geographic areas, Nhecolandia and Rio Negro regions. With routine biochemical tests and commercial kits 516 bacteria were identified, with 240 Gram-positive, predominantly staphylococci (36 and enterococci (186 strains. Among Gram-negative (GN bacteria the predominant specimens of Enterobacteriaceae (247 mainly represented by Serratia spp. (105, Escherichia coli (50, and Enterobacter spp. (40 and specimens not identified (7. Antimicrobial susceptibility was tested against 17 drugs by agar diffusion method. Staphylococci were negative to production of enterotoxins and TSST-1, with all strains sensitive towards four drugs and highest resistance toward ampicillin (17%. Enterococci presented the highest sensitivity against vancomycin (98%, ampicillin (94% and tetracycline (90%, and highest resistance pattern toward oxacillin (99%, clindamycin (83%, and cotrimoxazole (54%. In GN the highest resistance was observed with Serratia marcescens against CFL (98%, AMC (66% and AMP (60% and all drugs was most effective against E. coli SUT, TET (100%, AMP, TOB (98%, GEN, CLO (95%, CFO, CIP (93%. The results show a new profile of oxacillin-resistant enterococci from Brazilian feral pigs and suggest a limited residue and spreading of antimicrobials in the environment, possibly because of low anthropogenic impact reflected by the drug susceptibility profile of bacteria isolated.

[High-frequency rotation sensation function damage of the crista of the horizontal semicircular canal induced by gentamicin and its morphological basis.].

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Chen, Liang; He, Ming; Wang, Wu-Qing

2009-12-25

The goal of the present study was to explore high-frequency rotation sensation function damage of the crista of the horizontal semicircular canal induced by gentamicin and its morphological basis. The guinea pigs were randomly divided into four groups (group 1, 2, 3 and control group, n=20). The animals of treated groups received gentamicin subcutaneously (50 mg/kg per day) for 1 week (group 1), 2 weeks (group 2) and 3 weeks (group 3), respectively. The animals of control group were administered with equal volume of saline subcutaneously. Videonystagmography (VNG) evoked by ice water or high-frequency rotations, and vestibular evoked potential (VsEP) evoked by low- and high-frequency rotations were recorded after the administration. After VNG and VsEP were examined, the cristae of the horizontal semicircular canals were prepared for scanning and transmission electron microscopy. The results are as follows: (1) In VNG examination, after ice water stimulation, no obvious nystagmus was observed in the animals of group 3, and there was no significant difference in nystagmus frequency and duration among group 1, 2 and control group (P>0.05). After high- frequency rotations, no obvious nystagmus was yet observed in the animals of group 3. There were significant differences in the nystagmus frequency and duration of the VNG waves between the experimental group 2 and control group (P0.05). (2) In VsEP examination, there was no significant difference in the parameters of VsEP among group 1, 2 and control group (P>0.05), and VsEP was not observed in group 3 after low-frequency rotations. After high- frequency rotations, compared with control group, the latencies and amplitudes of P1 and P2 in group 2 significantly decreased (P0.05). Group 3 had no response of VsEP to high-frequency rotations. (3) Electron microscopy was used to observe the crista hair cells of the four groups. In control group, the hair cells were normal. In group 1, almost normal appearance with slight

Collateral Resistance and Sensitivity Modulate Evolution of High-Level Resistance to Drug Combination Treatment in Staphylococcus aureus

DEFF Research Database (Denmark)

de Evgrafov, Mari Cristina Rodriguez; Gumpert, Heidi; Munck, Christian

2015-01-01

As drug-resistant pathogens continue to emerge, combination therapy will increasingly be relied upon to treat infections and to help combat further development of multidrug resistance. At present a dichotomy exists between clinical practice, which favors therapeutically synergistic combinations......, to reflect drug concentrations more likely to be encountered during treatment. We performed a series of adaptive evolution experiments using Staphylococcus aureus. Interestingly, no relationship between drug interaction type and resistance evolution was found as resistance increased significantly beyond wild......-type levels. All drug combinations, irrespective of interaction types, effectively limited resistance evolution compared with monotreatment. Cross-resistance and collateral sensitivity were found to be important factors in the extent of resistance evolution toward a combination. Comparative genomic analyses...

Chitosan Prevents Gentamicin-Induced Nephrotoxicity via a Carbonyl Stress-Dependent Pathway

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Chu-Kung Chou

2015-01-01

Full Text Available Aminoglycosides are widely used to treat infections; however, their applications are limited by nephrotoxicity. With the increase of antibiotic resistance, the use of aminoglycosides is inevitable. Low-molecular-weight chitosan (LMWC has shown renal protective effects in dialysis patients. However, no study has evaluated LMWC for preventing aminoglycoside-induced nephrotoxicity or determined the mechanisms underlying the renal protective effects. In this study, LMWC (165 or 825 mg/kg/day or metformin (100 mg/kg/day was orally administered for 13 days to rats with nephropathy induced by gentamicin (GM, a kind of aminoglycoside (150 mg/kg/day i.p. for 6 days. Both LMCW doses improved renal function. Serum creatinine levels improved in rats treated with 165 and 825 mg/kg/day LMWC (from 2.14 ± 0.74 mg/dL to 1.26 ± 0.46 mg/dL and 0.69 ± 0.12 mg/dL, resp., P < 0.05. Blood urea nitrogen levels were also improved in these rats (from 73.73 ± 21.13 mg/dL to 58.70 ± 22.71 mg/dL and 28.82 ± 3.84 mg/dL, resp., P < 0.05. Additionally, renal tissue morphology improved after LMWC treatment, and accumulation of renal methylglyoxal, a damage factor associated with carbonyl stress, was reversed. These results show that LMWC prevents GM-induced renal toxicity via a carbonyl stress-dependent pathway.

Accumulation of multiple mutations in linezolid-resistant Staphylococcus epidermidis causing bloodstream infections; in silico analysis of L3 amino acid substitutions that might confer high-level linezolid resistance.

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Ikonomidis, Alexandros; Grapsa, Anastasia; Pavlioglou, Charikleia; Demiri, Antonia; Batarli, Alexandra; Panopoulou, Maria

2016-12-01

Fifty-six Staphylococcus epidermidis clinical isolates, showing high-level linezolid resistance and causing bacteremia in critically ill patients, were studied. All isolates belonged to ST22 clone and carried the T2504A and C2534T mutations in gene coding for 23SrRNA as well as the C189A, G208A, C209T and G384C missense mutations in L3 protein which resulted in Asp159Tyr, Gly152Asp and Leu94Val substitutions. Other silent mutations were also detected in genes coding for ribosomal proteins L3 and L22. In silico analysis of missense mutations showed that although L3 protein retained the sequence of secondary motifs, the tertiary structure was influenced. The observed alteration in L3 protein folding provides an indication on the putative role of L3-coding gene mutations in high-level linezolid resistance. Furthermore, linezolid pressure in health care settings where linezolid consumption is of high rates might lead to the selection of resistant mutants possessing L3 mutations that might confer high-level linezolid resistance.

Gentamicin-induced apoptosis in LLC-PK1 cells: Involvement of lysosomes and mitochondria

International Nuclear Information System (INIS)

Servais, Helene; Van Der Smissen, Patrick; Thirion, Gaetan; Van der Essen, Gauthier; Van Bambeke, Francoise; Tulkens, Paul M.; Mingeot-Leclercq, Marie-Paule

2005-01-01

Gentamicin accumulates in lysosomes and induces apoptosis in kidney proximal tubules and renal cell lines. Using LLC-PK1 cells, we have examined the concentration- and time-dependency of the effects exerted by gentamicin (1-3 mM; 0-3 days) on (i) lysosomal stability; (ii) activation of mitochondrial pathway; (iii) occurrence of apoptosis (concentrations larger than 3 mM caused extensive necrosis as assessed by the measurement of lactate dehydrogenase release). Within 2 h, gentamicin induced a partial relocalization [from lysosomes to cytosol] of the weak organic base acridine orange. We thereafter observed (a) a loss of mitochondrial membrane potential (as from 10 h, based on spectrophotometric and confocal microscopy using JC1 probe) and (b) the release of cytochrome c from granules to cytosol, and the activation of caspase-9 (as from 12 h; evidenced by Western blot analysis). Increase in caspase-3 activity (assayed with Ac-DEVD-AFC in the presence of z-VAD-fmk]) and appearance of fragmented nuclei (DAPI staining) was then detected as from 16 to 24 h together with nuclear fragmentation. Gentamicin produces a fast (within 4 h) release of calcein from negatively-charged liposomes at pH 5.4, which was slowed down by raising the pH to 7.4, or when phosphatidylinositol was replaced by cardiolipin (to mimic the inner mitochondrial membrane). The present data provide temporal evidence that gentamicin causes apoptosis in LLC-PK1 with successive alteration of the permeability of lysosomes, triggering of the mitochondrial pathway, and activation of caspase-3

A comparison of antimicrobial resistance rates in Gram-positive pathogens isolated in the UK from October 1996 to January 1997 and October 1997 to January 1998.

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Andrews, J; Ashby, J; Jevons, G; Marshall, T; Lines, N; Wise, R

2000-03-01

Rates of resistance for two consecutive years for 28 centres (10 Teaching, nine Associate Teaching and nine District General hospitals) in the UK were compared. Combined rates of resistance for each of the hospital types of Staphylococcus aureus to methicillin revealed an increase in the rate of resistance in Teaching hospitals (12.5% year 1, 23.5% year 2), but, for Associate Teaching and District General hospitals rates fell (Associate Teaching 19.1% year 1, 11.9% year 2; District General 16.5% year 1 and 11.3% year 2). Using conventional methodology to determine MICs, no strain was considered to have reduced susceptibility to vancomycin. Among coagulase-negative staphylococci, increased resistance was observed for Staphylococcus epidermidis to rifampicin, for Staphylococcus haemolyticus to clindamycin, for Staphylococcus saprophyticus to penicillin and for Staphylococcus spp. to clindamycin, methicillin and rifampicin. For Streptococcus pneumoniae an upward trend in low-level resistance to penicillin was observed (18 of the 28 centres), however, for high-level resistance the trend was in the opposite direction (only four centres showed an increase). For Enterococcus faecalis there was a trend to a fall in levels of resistance, the only exception being an increase in high-level gentamicin resistance (10.5% year 1, 15.1% year 2, P = 0.0388). For Enterococcus faecium rates of resistance were not significantly different except for increases in resistance to nitrofurantoin and rifampicin.

Round window administration of gentamicin: a new method for the study of ototoxicity of cochlear hair cells.

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Husmann, K R; Morgan, A S; Girod, D A; Durham, D

1998-11-01

Damage to inner ear sensory hair cells after systemic administration of ototoxic drugs has been documented in humans and animals. Birds have the ability to regenerate new hair cells to replace those damaged by drugs or noise. Unfortunately, the systemic administration of gentamicin damages both ears in a variable fashion with potentially confounding systemic drug effects. We developed a method of direct application of gentamicin to one cochlea of hatchling chickens, allowing the other ear to serve as a within-animal control. We tested variables including the vehicle for application, location of application, dosage, and duration of gentamicin exposure. After 5 or 28 days survival, the percent length damage to the cochlea and regeneration of hair cells was evaluated using scanning electron microscopy. Controls consisted of the opposite unexposed cochlea and additional animals which received saline instead of gentamicin. Excellent damage was achieved using gentamicin-soaked Gelfoam pledgets applied to the round window membrane. The percent length damage could be varied from 15 to 100% by changing the dosage of gentamicin, with exposures as short as 30 min. No damage was observed in control animals. Regeneration of hair cells was observed in both the base and apex by 28 days survival.

Transdermal delivery of gentamicin using dissolving microneedle arrays for potential treatment of neonatal sepsis.

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González-Vázquez, Patricia; Larrañeta, Eneko; McCrudden, Maelíosa T C; Jarrahian, Courtney; Rein-Weston, Annie; Quintanar-Solares, Manjari; Zehrung, Darin; McCarthy, Helen; Courtenay, Aaron J; Donnelly, Ryan F

2017-11-10

Neonatal infections are a leading cause of childhood mortality in low-resource settings. World Health Organization guidelines for outpatient treatment of possible serious bacterial infection (PSBI) in neonates and young infants when referral for hospital treatment is not feasible include intramuscular gentamicin (GEN) and oral amoxicillin. GEN is supplied as an aqueous solution of gentamicin sulphate in vials or ampoules and requires health care workers to be trained in dose calculation or selection of an appropriate dose based on the patient's weight band and to have access to safe injection supplies and appropriate sharps disposal. A simplified formulation, packaging, and delivery method to treat PSBI in low-resource settings could decrease user error and expand access to lifesaving outpatient antibiotic treatment for infants with severe infection during the neonatal period. We developed dissolving polymeric microneedles (MN) arrays to deliver GEN transdermally. MN arrays were produced from aqueous blends containing 30% (w/w) of GEN and two polymers approved by the US Food and Drug Administration: sodium hyaluronate and poly(vinylpyrrolidone). The arrays (19×19 needles and 500μm height) were mechanically strong and were able to penetrate a skin simulant to a depth of 378μm. The MN arrays were tested in vitro using a Franz Cell setup delivering approximately 4.45mg of GEN over 6h. Finally, three different doses (low, medium, and high) of GEN delivered by MN arrays were tested in an animal model. Maximum plasma levels of GEN were dose-dependent and ranged between 2 and 5μg/mL. The time required to reach these levels post-MN array application ranged between 1 and 6h. This work demonstrated the potential of dissolving MN arrays to deliver GEN transdermally at therapeutic levels in vivo. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Antimicrobial resistance of Staphylococcus species isolated from Lebanese dairy-based products.

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Zouhairi, O; Saleh, I; Alwan, N; Toufeili, I; Barbour, E; Harakeh, S

2012-12-04

The study evaluated the antimicrobial resistance of molecularly characterized strains of Staphylococcus aureus and S. saprophyticus isolated from 3 Lebanese dairy-based food products that are sometimes consumed raw: kishk, shanklish and baladi cheese. Suspected Staphylococcus isolates were identified initially using standard biochemical tests, then strains that were confirmed by polymerase chain reaction (29 S. aureus and 17 S. saprophyticus) were evaluated for their susceptibility to different antimicrobials. The highest levels of contamination with staphylococci were in baladi cheese. Resistance rates ranged from 67% to gentamicin to 94% to oxacillin and clindamycin. The results suggest that these locally made dairy-based foods may act as vehicles for the transmission of antimicrobial-resistant Staphylococcus spp.

Antimicrobial Resistance and Resistance Genes in Aerobic Bacteria Isolated from Pork at Slaughter.

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Li, Lili; Heidemann Olsen, Rikke; Ye, Lei; Yan, He; Nie, Qing; Meng, Hecheng; Shi, Lei

2016-04-01

The aim of this study was to investigate the phenotypic and genotypic antimicrobial resistance, integrons, and transferability of resistance markers in 243 aerobic bacteria recovered from pork at slaughter in the People's Republic of China. The organisms belonged to 22 genera of gram-negative bacteria (92.2%) and gram-positive bacteria (7.8%). High levels of resistance were detected to tetracycline, trimethoprim-sulfamethoxazole, and ampicillin (36.2 to 54.3%), and lower levels were detected to nitrofurantoin, cefotaxime, gentamicin, ciprofloxacin, and chloramphenicol (7.8 to 29.2%). Across species, genes conferring antimicrobial resistance were observed with the following frequencies: blaTEM, 40.7%; blaCMY-2, 15.2%; blaCTX-M, 11.5%; sul2, 27.2%; sul1, 14.4%; tet(A), 5.4%; tet(L), 5.4%; tet(M), 5.0%; tet(E), 3.7%; tet(C), 3.3%; tet(S), 2.5%; and tet(K), 0.8%. Various antimicrobial resistance genes were found in new carriers: blaTEM in Lactococcus garvieae, Myroides odoratimimus, Aeromonas hydrophila, Staphylococcus sciuri, Raoultella terrigena, Macrococcus caseolyticus, Acinetobacter ursingii, Sphingobacterium sp., and Oceanobacillus sp.; blaCMY-2 in Lactococcus lactis, Klebsiella oxytoca, Serratia marcescens, Acinetobacter baumannii, and Myroides phaeus; tet(L) in M. caseolyticus; sul1 in Vibrio cincinnatiensis; sul2 in Acinetobacter bereziniae, Acinetobacter johnsonii, and V. cincinnatiensis; and the class 1 integron and gene cassette aadA2 in V. cincinnatiensis. Approximately 6.6% of isolates contained class 1 integrons, and one isolate harbored class 2 integrons. Plasmid associated intI1 and androgen receptor- encoding genes were transferred into Escherichia coli J53 and E. coli DH5α by conjugation and transformation experiments, respectively. Our study highlights the importance of aerobic bacteria from pork as reservoirs for antimicrobial resistance genes and mobile genetic elements that can readily be transferred intra- and interspecies.

Aminoglycoside resistance among isolates of nosocomial Enterobacteriaceae

International Nuclear Information System (INIS)

Botha, P.L.; Elisha, G.; Pratt, K.

1981-01-01

Fifty-seven gentamicin-resistant isolates of Enterobacteriaceae, obtained from patients attending hospital, were examined for the production of aminoglycoside-modifying enzymes. Of the 51 strains producing such enzymes, 34 were presumptively plasmid-mediated as indicated by conjugation experiments

Prevalence of resistance to 11 antimicrobials among Campylobacter coill isolated from pigs on 80 grower-finisher farms in Ontario.

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Varela, Norma P; Friendship, Robert; Dewey, Cate

2007-07-01

We carried out a cross-sectional study to investigate antimicrobial resistance patterns of Campylobacter coli isolated from Ontario grower-finisher pigs. From January to June 2004, 1200 samples were collected from 80 farms by obtaining a constant number (15) of fecal samples per farm. Susceptibility of the isolates to 11 antimicrobial drugs was determined by the agar-dilution technique. The overall prevalence of resistance to 1 or more antimicrobials among the isolates was 99.2%. High levels of resistance were observed for azithromycin, clindamycin, erythromycin, streptomycin, and tetracycline: 91.7%, 82.5%, 81.4%, 70.7%, and 63.7%, respectively. For sulfamethoxazole, ampicillin, and nalidixic acid, resistance was observed in 40.3%, 26.6%, and 22.7% of the isolates, respectively. Although at very low levels, resistance was observed for ciprofloxacin (a fluoroquinolone), chloramphenicol, and gentamicin: in 2.4%, 1.7%, and 0.2%, respectively. Many of the isolates (29.7%) were resistant to 5 antimicrobials, the most common being azithromycin, clindamycin, erythromycin, streptomycin, and tetracycline. Isolates from the same farm showed at least 5 patterns of resistance. Results from this study indicate high levels of resistance to the antimicrobial drugs most commonly used in the Canadian swine industry (macrolides, lincosamides, and tetracyclines) among C. coli isolated from grower-finisher pigs in Ontario. Macrolides and fluoroquinolones are the drugs most commonly used to treat severe human campylobacteriosis. Fortunately, at present, there is little resistance to fluoroquinolones among C. coli from pigs in Ontario.

Phenotypic low-level isoniazid resistance as a marker to predict ethionamide resistance in Mycobacterium tuberculosis

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Salima Qamar

2017-01-01

Full Text Available Background: Tuberculosis is one of the most prevalent diseases in Pakistan. Pakistan has the highest burden of MDR-TB in the Eastern Mediterranean region. Ethionamide is an anti-tuberculous drug frequently used to treat MDR-TB. Its drug susceptibility testing is not easily available in resource limited settings. Since it acts on the same target protein as isoniazid (inhA protein encoded by inhA gene, we sought to find out if phenotypic isoniazid resistance can be a marker of ethionamide resistance. Materials and Methods: This was a retrospective observational study conducted at the Aga Khan University hospital section of microbiology. Data was retrieved between 2011 to 2014 for all culture positive MTB strains. All culture positive MTB isolates with susceptibilities to isoniazid and ethionamide recorded were included in the study. Isoniazid and ethionamide susceptibilities were performed using agar proportion method on Middlebrook 7H10 agar. Rate of Ethionamide resistance between low-level isoniazid resistant, high level isoniazid resistant and isoniazid sensitive MTB was compared. Results: A total of 11,274 isolates were included in the study. A statistically significant association (P < 0.001 was found between Ethionamide resistance and low-level isoniazid resistance (26.6% as compared to high-level isoniazid resistance (8.85% and isoniazid sensitivity (0.71% in MTB strains. However this association was not seen in XDR-TB strains. Conclusion: Low level isoniazid resistance may be used as marker for phenotypic ethionamide resistance and hence guide clinicians' choice of antituberculous agent for MDR-TB in Pakistan. Further studies involving detection of genotypic association of isoniazid and ethionamide susceptibilities are needed before a final conclusion can be derived.

Release of Gentamicin and Vancomycin from Preformed Spacers in Infected Total Hip Arthroplasties: Measurement of Concentrations and Inhibitory Activity in Patients’ Drainage Fluids and Serum

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Dario Regis

2013-01-01

Full Text Available Gentamicin (G and vancomycin (V concentrations in drainage fluids obtained from patients during the first 24 hours after implantation of antibiotic-loaded polymethylmethacrylate (PMMA spacers in two-stage revision of infected total hip arthroplasty were studied. The inhibitory activity of drainage fluids against different multiresistant clinical isolates was investigated as well. Seven hips were treated by implantation of industrial G-loaded spacers. Vancomycin was added by manually mixing with PMMA bone cement. Serum and drainage fluid samples were collected 1, 4, and 24 hours after spacer implantation. Antibiotics concentrations and drains bactericidal titer of combination were determined against multiresistant staphylococcal strains. The release of G and V from PMMA cement at the site of infection was prompt and effective. Serum levels were below the limit of detection. The local release kinetics of G and V from PMMA cement was similar, exerting a pronounced, combined inhibitory effect in the implant site. The inhibitory activity of drainage fluids showed substantial intersubject variability related to antibiotic concentrations and differed according to the pathogens tested. Gentamicin and vancomycin were released from temporary hip spacers at bactericidal concentrations, and their use in combination exerted strong inhibition against methicillin-resistant S. aureus and Coagulase Negative Staphylococci strains.

Developmental pharmacokinetics of gentamicin in preterm and term neonates

DEFF Research Database (Denmark)

Nielsen, Elisabet I; Sandström, Marie; Honoré, Per Hartvig

2009-01-01

0-45 days) were enrolled in the study. In total, 894 serum gentamicin samples were included in the analysis. The concentration-time profile was described using a three-compartment model. Gentamicin clearance increased with the GA and PNA (included in a nonlinear fashion). The GA was also identified...... in this patient population. METHODS: Data were collected in a prospective study performed in the Neonatal Intensive Care Unit at the University Children's Hospital, Uppsala, Sweden. Population pharmacokinetic modelling was performed using nonlinear mixed-effects modelling (NONMEM) software. Bodyweight...... was included as the primary covariate according to an allometric power model. Other evaluated covariates were age (postmenstrual age, gestational age [GA], postnatal age [PNA]), markers for renal function (serum creatinine, serum cystatin C) and concomitant medication with cefuroxime, vancomycin or indometacin...

Virulence factors and antibiotic susceptibility in enterococci isolated from oral mucosal and deep infections

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Gunnar Dahlén

2012-02-01

Full Text Available This study evaluates the presence of virulence factors and antibiotic susceptibility among enterococcal isolates from oral mucosal and deep infections. Forty-three enterococcal strains from oral mucosal lesions and 18 from deep infections were isolated from 830 samples that were sent during 2 years to Oral Microbiology, University of Gothenburg, for analysis. The 61 strains were identified by 16S rDNA, and characterized by the presence of the virulence genes efa A (endocarditis gene, gel E (gelatinase gene, ace (collagen binding antigen gene, asa (aggregation substance gene, cyl A (cytolysin activator gene and esp (surface adhesin gene, tested for the production of bacteriocins and presence of plasmids. MIC determination was performed using the E-test method against the most commonly used antibiotics in dentistry, for example, penicillin V, amoxicillin and clindamycin. Vancomycin was included in order to detect vancomycin-resistant enterococci (VRE strains. Sixty strains were identified as Enterococcus faecalis and one as Enterococcus faecium. All the virulence genes were detected in more than 93.3% (efa A and esp of the E. faecalis strains, while the presence of phenotypic characteristics was much lower (gelatinase 10% and hemolysin 16.7%. Forty-six strains produced bacteriocins and one to six plasmids were detected in half of the isolates. Enterococcal strains from oral infections had a high virulence capacity, showed bacteriocin production and had numerous plasmids. They were generally susceptible to ampicillins but were resistant to clindamycin, commonly used in dentistry, and no VRE-strain was found.

Vancomycin-resistant Enterococcus spp.: validation of susceptibility testing and in vitro activity of vancomycin, linezolid, tigecycline and daptomycin

DEFF Research Database (Denmark)

Rathe, Mathias; Kristensen, Lise; Ellermann-Eriksen, Svend

2010-01-01

Vancomycin-resistant enterococci (VRE) have emerged to become a significant nosocomial pathogen. However, detection may be challenging and treatment possibilities are limited. Reports of resistance to linezolide, daptomycin and tigecycline underline the need for reliable susceptibility testing wi...

Usage of antimicrobials and occurrence of antimicrobial resistance among bacteria from mink

DEFF Research Database (Denmark)

Pedersen, Karl; Hammer, Anne Sofie; Sørensen, Charlotte Mark

2009-01-01

, whereas resistance to other antimicrobials was rare. All P aeruginosa were sensitive to gentamicin and colistin and sensitive or intermediate to enrofloxacin. whereas most isolates were resistant to all other antimicrobials. All P. multocida and haemolytic streptococci were sensitive to penicillin...

Correlations between Income inequality and antimicrobial resistance.

Science.gov (United States)

Kirby, Andrew; Herbert, Annie

2013-01-01

The aim of this study is to investigate if correlations exist between income inequality and antimicrobial resistance. This study's hypothesis is that income inequality at the national level is positively correlated with antimicrobial resistance within developed countries. Income inequality data were obtained from the Standardized World Income Inequality Database. Antimicrobial resistance data were obtained from the European antimicrobial Resistance Surveillance Network and outpatient antimicrobial consumption data, measured by Defined daily Doses per 1000 inhabitants per day, from the European Surveillance of antimicrobial Consumption group. Spearman's correlation coefficient (r) defined strengths of correlations of: > 0.8 as strong, > 0.5 as moderate and > 0.2 as weak. Confidence intervals and p values were defined for all r values. Correlations were calculated for the time period 2003-10, for 15 European countries. Income inequality and antimicrobial resistance correlations which were moderate or strong, with 95% confidence intervals > 0, included the following. Enterococcus faecalis resistance to aminopenicillins, vancomycin and high level gentamicin was moderately associated with income inequality (r= ≥0.54 for all three antimicrobials). Escherichia coli resistance to aminoglycosides, aminopenicillins, third generation cephalosporins and fluoroquinolones was moderately-strongly associated with income inequality (r= ≥0.7 for all four antimicrobials). Klebsiella pneumoniae resistance to third generation cephalosporins, aminoglycosides and fluoroquinolones was moderately associated with income inequality (r= ≥0.5 for all three antimicrobials). Staphylococcus aureus methicillin resistance and income inequality were strongly associated (r=0.87). As income inequality increases in European countries so do the rates of antimicrobial resistance for bacteria including E. faecalis, E. coli, K. pneumoniae and S. aureus. Further studies are needed to confirm these

Vaginal versus Obstetric Infection Escherichia coli Isolates among Pregnant Women: Antimicrobial Resistance and Genetic Virulence Profile.

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Emma Sáez-López

Full Text Available Vaginal Escherichia coli colonization is related to obstetric infections and the consequent development of infections in newborns. Ampicillin resistance among E. coli strains is increasing, which is the main choice for treating empirically many obstetric and neonatal infections. Vaginal E. coli strains are very similar to extraintestinal pathogenic E. coli with regards to the virulence factors and the belonging to phylogroup B2. We studied the antimicrobial resistance and the genetic virulence profile of 82 E. coli isolates from 638 vaginal samples and 63 isolated from endometrial aspirate, placental and amniotic fluid samples from pregnant women with obstetric infections. The prevalence of E. coli in the vaginal samples was 13%, which was significant among women with associated risk factors during pregnancy, especially premature preterm rupture of membranes (p<0.0001. Sixty-five percent of the strains were ampicillin-resistant. The E. coli isolates causing obstetric infections showed higher resistance levels than vaginal isolates, particularly for gentamicin (p = 0.001. The most prevalent virulence factor genes were those related to the iron uptake systems revealing clear targets for interventions. More than 50% of the isolates belonged to the virulent B2 group possessing the highest number of virulence factor genes. The ampicillin-resistant isolates had high number of virulence factors primarily related to pathogenicity islands, and the remarkable gentamicin resistance in E. coli isolates from women presenting obstetric infections, the choice of the most appropriate empiric treatment and clinical management of pregnant women and neonates should be carefully made. Taking into account host-susceptibility, the heterogeneity of E. coli due to evolution over time and the geographical area, characterization of E. coli isolates colonizing the vagina and causing obstetric infections in different regions may help to develop interventions and avoid the

A New Type of Biphasic Calcium Phosphate Cement as a Gentamicin Carrier for Osteomyelitis

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Wen-Yu Su

2013-01-01

Full Text Available Osteomyelitis therapy is a long-term and inconvenient procedure for a patient. Antibiotic-loaded bone cements are both a complementary and alternative treatment option to intravenous antibiotic therapy for the treatment of osteomyelitis. In the current study, the biphasic calcium phosphate cement (CPC, called α-TCP/HAP (α-tricalcium phosphate/hydroxyapatite biphasic cement, was prepared as an antibiotics carrier for osteomyelitis. The developed biphasic cement with a microstructure of α-TCP surrounding the HAP has a fast setting time which will fulfill the clinical demand. The X-ray diffraction and Fourier transform infrared spectrometry analyses showed the final phase to be HAP, the basic bone mineral, after setting for a period of time. Scanning electron microscopy revealed a porous structure with particle sizes of a few micrometers. The addition of gentamicin in α-TCP/HAP would delay the transition of α-TCP but would not change the final-phase HAP. The gentamicin-loaded α-TCP/HAP supplies high doses of the antibiotic during the initial 24 hours when they are soaked in phosphate buffer solution (PBS. Thereafter, a slower drug release is produced, supplying minimum inhibitory concentration until the end of the experiment (30 days. Studies of growth inhibition of Staphylococcus aureus and Pseudomonas aeruginosa in culture indicated that gentamicin released after 30 days from α-TCP/HAP biphasic cement retained antibacterial activity.

ORIGINAL ARTICLE: Multidrug Resistance and Phage Pattern of Staphylococcus aureus in Pyoderma Cases

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Sanjay M. Wavare

2012-01-01

Full Text Available Background: Pyoderma is common in India and other tropical countries. Staphylococcus aureus is the commonest causative agent ofpyoderma. Aims and Objectives: To know the antibiotic susceptibility and bacteriophage pattern of Staphylococcus aureus isolated from pyoderma infection. Materials and Methods: One hundred clinically diagnosed pyoderma cases were investigated bacteriologically. A total of 59 isolates of S. aureus were subjected to antibioticsusceptibility testing by Kirby Bauer’s disk diffusion method and phage typing by routine test dilution X 100 bacteriophages. Results: Most of the strains were resistant to penicillin, ampicillin and were susceptible to gentamicin, streptomycin and erythromycin. Multidrug resistance was also high among these strains. Regarding the phage types, Phage type 52 (15 strains, 96 (8 strains and 71(16strains were predominant among the typed strains (55.95% of S. aureus. The most common group was mixed phage group (17% followed by phage group I (13.55%. Conclusion: Knowledge of antibioticsusceptibility pattern is essential to give proper antibiotic therapy and avoid unnecessary medication with non-effective drugs, which may increase resistance. Gentamicin, streptomycin and erythromycin are the drugs of choice in that order. Association of phage typing and antibiotic sensitivity of S. aureus showed the predominance of phage group III with greater frequency of penicillin resistance.

In vitro antimicrobial susceptibility in clinical isolates of Enterococcus species Susceptibilidad antimicrobiana in vitro en aislamientos clínicos de Enterococcus species

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Ernesto Calderón-Jaimes

2003-04-01

Full Text Available OBJECTIVE: To describe the antimicrobial activity of several antimicrobial agents against 97 clinical significant isolates of Enterococcus spp. MATHERIAL AND METHODS: During a 2-year prospective study at Instituto Nacional de Pediatria (National Institute of Pediatrics in Mexico City. Ninety seven strains of Enterococcus spp. (60 E. faecalis and 37 E. faecium were tested against 11 antibiotics. Susceptibility tests were performed with agar, according to the standards of the sNational Committee for Clinical Laboratory Standards (NCCLS. Isolates were screened for high-level resistance (HLR to beta-lactams, aminoglycosides, glycopeptides and other antibiotics, as well as for vancomycin-phenotypes. Differences between proportions were evaluated with chi2 of Fisher exact fest. RESULTS: Overall resistance rates to the antibiotics tested were: 17/97 (17.5% to penicillin, ampicillin, amoxicillin-clavulanate and imipenem. There was neither HLR nor beta-lactamase production; 74/97 (48.4% were resistant to erythromycin; 60% to ciprofloxacin; 31/97 (32% to gentamicin, and 55/97 (56.7% to streptomycin. Seven strains were vancomycin-resistant enterococci (VRE, all of them identified as E. faecium; 5/7 with Van A and 2/7 with Van B phenotypes. All the isolates were susceptible to linezolid. The difference in susceptibility among species was significant. CONCLUSIONS: Mutidrug-resistant enterococci is a real problem and continuous surveillance is necessary. The microbiology laboratory is the first line of defense against the spread of multiantibiotic-resistan enterococci in the hospital environment . All the strains recovered should be tested for susceptibility to ampicillin, streptomycin, gentamicin and glycopeptides.OBJECTIVO: Describir la actividad antimicrobiana de varios antibióticos, contra 97 cepas de Enterococcus spp., consideradas como aislamientos clínicamente significativos. MATERIAL Y MÉTODOS: En un estudio prospectivo de dos años, (enero de 1998

General Tritium Labelling of Gentamicin C by catalytic hydrogen exchange Reaction with Tritiated Water

International Nuclear Information System (INIS)

Suarez, C.; Diaz, D.; Paz, D.

1991-01-01

Gentamicin C was labelled with tritium by means of a PtO2 catalyzed hydrogen exchange reaction. Under the conditions of the exchange (100 mg of gentamicin, basic form, 0,3 ml H2O-3H, and 50 mg of prereduced PtO2) the radiochemical yield was 0,24, 0,38 and 0,48 % at 120 degree celsius, for 8, 16 and 24 hours respectively. Chemical yield for purified gentamicin was about 60 %. Purification was accomplished with a cellulose column eluted with the lower phase of chloroform-methanol 17 % ammonium hydroxide (2:1:1, v/v) . Chemical purity, determined by HPLC, was 96,5 % and radiochemical one was 95. Main exchange degradation products show biological activity. (Author) 12 refs

General Tritium labelling of gentamicin C by catalytic hydrogen exchange reaction with tritiated water

International Nuclear Information System (INIS)

Suarez, C.; Diaz, D.

1991-01-01

Gentamicin C was labelled with tritium by means of a PtO 2 catalized hydrogen exchange reaction. Under the conditions of the exchange (100 mg of gentamicin, basic form, 0,3 ml H 2 O- 3 H, and 50 mg of prereduced PtO 2 ) the radiochemical yield was 0,24, 0,38 and 0,48 % at 120 o C, for 8, 16 and 24 hours respectively. Chemical yield for purified gentamicin was about 60 %. Purification was accoumplished with a cellulose column eluted with the lower phase of chloroform-methanol 17 % ammonium hydroxide (2:1:1, v/v). Chemical purity, determined by HPLC, was 96,5 % and radiochemical one was 95 % . Main exchange degradation products show biological activity. (Author). 12 refs

Immunological methods for gentamicin determination

International Nuclear Information System (INIS)

Krugers Dagneauz, P.G.L.C.; Olthuis, F.M.F.G.

1979-01-01

For immunoassay, an antibody against the substance to the determined, the pure substance itself, and a labelled form or derivative of the substance are required. The principles and problems of the preparation of antibodies are discussed, some methods for the preparation of derivatives labelled with radioactive tracers or enzymes are reviewed, and homologous enzyme-immunological determination of gentamicin is discussed in detail. A comparison is mae of three radio-immunological determination methods, and the most suitable radio-immunological method is compared with two microbiological techniques. The results are found to be comparable. (Auth.)

Rapid detection of Escherichia coli and enterococci in recreational water using an immunomagnetic separation/adenosine triphosphate technique

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Bushon, R.N.; Brady, A.M.; Likirdopulos, C.A.; Cireddu, J.V.

2009-01-01

Aims: The aim of this study was to examine a rapid method for detecting Escherichia coli and enterococci in recreational water. Methods and Results: Water samples were assayed for E. coli and enterococci by traditional and immunomagnetic separation/adenosine triphosphate (IMS/ATP) methods. Three sample treatments were evaluated for the IMS/ATP method: double filtration, single filtration, and direct analysis. Pearson's correlation analysis showed strong, significant, linear relations between IMS/ATP and traditional methods for all sample treatments; strongest linear correlations were with the direct analysis (r = 0.62 and 0.77 for E. coli and enterococci, respectively). Additionally, simple linear regression was used to estimate bacteria concentrations as a function of IMS/ATP results. The correct classification of water-quality criteria was 67% for E. coli and 80% for enterococci. Conclusions: The IMS/ATP method is a viable alternative to traditional methods for faecal-indicator bacteria. Significance and Impact of the Study: The IMS/ATP method addresses critical public health needs for the rapid detection of faecal-indicator contamination and has potential for satisfying US legislative mandates requiring methods to detect bathing water contamination in 2 h or less. Moreover, IMS/ATP equipment is considerably less costly and more portable than that for molecular methods, making the method suitable for field applications. ?? 2009 The Authors.

Antimicrobial Resistance in Invasive Bacterial Infections in Hospitalized Children, Cambodia, 2007-2016.

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Fox-Lewis, Andrew; Takata, Junko; Miliya, Thyl; Lubell, Yoel; Soeng, Sona; Sar, Poda; Rith, Kolthida; McKellar, Gregor; Wuthiekanun, Vanaporn; McGonagle, Erin; Stoesser, Nicole; Moore, Catrin E; Parry, Christopher M; Turner, Claudia; Day, Nicholas P J; Cooper, Ben S; Turner, Paul

2018-05-01

To determine trends, mortality rates, and costs of antimicrobial resistance in invasive bacterial infections in hospitalized children, we analyzed data from Angkor Hospital for Children, Siem Reap, Cambodia, for 2007-2016. A total of 39,050 cultures yielded 1,341 target pathogens. Resistance rates were high; 82% each of Escherichia coli and Klebsiella pneumoniae isolates were multidrug resistant. Hospital-acquired isolates were more often resistant than community-acquired isolates; resistance trends over time were heterogeneous. K. pneumoniae isolates from neonates were more likely than those from nonneonates to be resistant to ampicillin-gentamicin and third-generation cephalosporins. In patients with community-acquired gram-negative bacteremia, third-generation cephalosporin resistance was associated with increased mortality rates, increased intensive care unit admissions, and 2.26-fold increased healthcare costs among survivors. High antimicrobial resistance in this setting is a threat to human life and the economy. In similar low-resource settings, our methods could be reproduced as a robust surveillance model for antimicrobial resistance.

Histological Evidence of Nephroprotective Effect of Ashwagandha (Withania somnifera Root Extract against Gentamicin Induced Nephrotoxicity in Rats

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Sadia Choudhury Shimmi

2014-01-01

Full Text Available Background: Kidney damage can occur due to exposure to nephrotoxic drugs, chemicals, toxins and infectious agents, ultimately leading to renal failure, management of which is a great challenge. So, efforts have been focused on traditional and herbal medicines for the treatment of renal failure. Ashwagandha (Withania somnifera may have free radical scavenging activity and can be used for the prevention and treatment of kidney damage. Objective: To observe the histological evidence of nephroprotective effect of Ashwagandha root against gentamicin induced nephrotoxicity in rats. Materials and Methods: This study was done in the department of Physiology, Sir Salimullah Medical College, Dhaka. A total number of 31 male Wistar albino rats were acclimatized for 14 days. Then, these were divided into two groups, control group consisted of 18 rats (Group A and Ashwagandha pretreated and gentamicin-treated group consisted of 13 rats (Group B. Control group was again subdivided into baseline control and gentamicin-treated control groups (A1 and A2 ─ each group contained 9 rats. All the animals received basal diet for 22 consecutive days. In addition to this, animals of Group A2 received gentamicin subcutaneously (100 mg/kg body weight/day from 15th to 22nd day and animals of Group B received Ashwagandha root extract (500 mg/kg body weight/day orally for 22 consecutive days and gentamicin subcutaneously (100 mg/kg body weight/day from 15th to 22nd day. All the animals were sacrificed on 23rd day. Then kidney samples were collected and histology was done by using standard laboratory procedure. Results: Histological examination of kidney revealed abnormal histological findings in 100% of gentamicin-treated rats. But 92.31% of rats in Ashwagandha pretreated and gentamicin-treated group showed almost normal structure and 7.69% showed mild histological changes. Conclusion: Ashwagandha root may have some nephroprotective effect against gentamicin induced

Antibacterial efficacy of core-shell nanostructures encapsulating gentamicin against an in vivo intracellular  Salmonella model

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Ashish Ranjan

2009-12-01

Full Text Available Ashish Ranjan1, Nikorn Pothayee2,3, Mohammed N Seleem2, Ronald D Tyler Jr4, Bonnie Brenseke4, Nammalwar Sriranganathan2,4, Judy S Riffle2,3, Ramanathan Kasimanickam11Department of Large Animal Clinical Sciences, 2Institute for Critical Technology and Applied Science, 3Macromolecules and Interfaces Institute, 4Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VAAbstract: Pluronic based core-shell nanostructures encapsulating gentamicin were designed in this study. Block copolymers of (PAA–+Na-b-(PEO-b-PPO-b-PEO-b-PAA– +Na were blended with PAA– Na+ and complexed with the polycationic antibiotic gentamicin to form nanostructures. Synthesized nanostructures had a hydrodynamic diameter of 210 nm, zeta potentials of –0.7 (±0.2, and incorporated ~20% by weight of gentamicin. Nanostructures upon co-incubation with J774A.1 macrophage cells showed no adverse toxicity in vitro. Nanostructures administered in vivo either at multiple dosage of 5 µg g–1 or single dosage of 15 µg g–1 in AJ-646 mice infected with Salmonella resulted in significant reduction of viable bacteria in the liver and spleen. Histopathological evaluation for concentration-dependent toxicity at a dosage of 15 µg g–1 revealed mineralized deposits in 50% kidney tissues of free gentamicin-treated mice which in contrast was absent in nanostructure-treated mice. Thus, encapsulation of gentamicin in nanostructures may reduce toxicity and improve in vivo bacterial clearance.Keywords: gentamicin, core-shell nanostructures, Salmonella

Effects of benfotiamine and coenzyme Q10 on kidney damage induced gentamicin.

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Ustuner, Mehmet Alperen; Kaman, Dilara; Colakoglu, Neriman

2017-12-01

Gentamicin (GM) is an effective antibiotic against severe infection but has limitations related to nephrotoxicity. In this study, we investigated whether benfotiamine (BFT) and coenzyme Q10 (CoQ10), could ameliorate the nephrotoxic effect of GM in rats. Rats were divided into five groups. Group 1 and 2 served as control and sham respectively, Group 3 as GM group, Group 4 as GM+CoQ10 and Group 5 as GM+BFT for 8days. At the end of the study, all rats were euthanized by cervical decapitation and then blood samples and kidneys were collected for further analysis. Serum urea, creatinine, cytokine TNF-a, oxidant and antioxidant parameters, as well as histopathological examination of kidney tissues were assessed. Gentamicin administration caused a severe nephrotoxicity which was evidenced by an elevated serum creatinine, urea and KIM-1 level as compared with the controls. Moreover, a significant increase in serum malondialdehyde, reduced glutathione. Histopathological examination of renal tissue in gentamisin administered group, there were extremly pronounced necrotic tubules in the renal cortex and hyalen cast accumulation in the medullar tubuli. BFT given to GM rats reduced these nephrotoxicity parameters. Serum creatinine, urea, and KIM-1 were almost normalized in the GM+BFT group. Benfotiamin treatment was significantly decreased necrotic tubuli and hyalen deposition in gentamisin plus benfotiamin group. CoQ10 given to GM rats did not cause any statistically significant alterations in these nephrotoxicity parameters when compared with GM group but histopathological examination of renal tissue in GM+CoQ10 administered group, CoQ10 treatment was decreased necrotic tubuli rate and hyalen accumulation in tubuli. The results from our study indicate that BFT supplement attenuates gentamicin-induced renal injury via the amelioration of oxidative stress and inflammation of renal tubular cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antibiotic resistance of canine Staphylococcus intermedius group (SIG)--practical implications.

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Chrobak, D; Kizerwetter-Swida, M; Rzewuska, M; Binek, M

2011-01-01

A total of 221 SIG strains were isolated from clinical samples of canine origin submitted to the Diagnostic Laboratory of the Division of Bacteriology and Molecular Biology at the Warsaw University of Life Sciences in Warsaw during the period 2006-2010. The aim of the study was to investigate the frequency of prevalence of methicillin-resistant SIG strains and to determine the MIC values of cephalotin, amoxicillin/clavulanic acid, ciprofloxacin, clindamycin, gentamicin, chloramphenicol, mupirocin for a collection of randomly selected 79 strains belonging to Staphylococcus intermedius group (SIG), including 23 mecA-positive and 56 mecA-negative strains. All isolates were identified as belonging to SIG based on their phenotypic properties and PCR amplification of S. intermedius-specific fragment of the 16S rRNA gene. The mecA gene was detected in 26 (12%) of 221 SIG strains. All tested mecA-negative SIG strains were susceptible to amoxicillin/clavulanic acid and cephalotin. One of the 56 mecA-negative SIG strains was resistant to ciprofloxacin, six (11%) to gentamicin. It was found that sixteen (29%) of 56 mecA-negative SIG strains were resistant to clindamycin. Most of the mecA-positive SIG strains were resistant to ciprofloxacin (96%), clindamycin (96%), and gentamicin (96%). Only one MRSIG strain was resistant to chloramphenicol. All examined mecA-positive SIG strains were found to be susceptible to mupirocin. Our results imply that staphylococcal multidrug resistance has become more prevalent, which could lead to difficulties in effective treatment. With some resistant strains the only therapeutic possibility are antimicrobial agents important in human medicine. New regulations for veterinary medicine concerning appropriate therapy of infections caused by multidrug-resistat staphylococci are needed.

Effect of normobaric hyperoxia on gentamicin-induced nephrotoxicity in rats

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Majid Tavafi

2014-04-01

Full Text Available Objective(s:Gentamicin sulphate (GS nephrotoxicity seems to be related to the generation of reactive oxygen species. There is evidence that oxygen preconditioning increases the activity of antioxidant enzymes. Materials and Methods: Forty eight female rats were divided into 6 groups (n=8 as follows: group 1 was the control, group 2 received daily GS, groups 3,4 and 5 received oxygen 2 hr/day for 2 days, 4 hr/day for 2 days, 4 hr/day for 4 days, recpectively and then received daily GS, group 6 received oxygen 2 hr/day for 2 days and then received 2 hr oxygen before daily GS injection. Oxygen (with 90% purity used at the flow rate of 4 l/min. GS administred for 8 days (100 mg/kg, IP. Tissue sections prepared from the left kidney, stained with PAS method and then studied hisopathologically and stereologically. The right kidneys were homogenized and the supernatants were prepared. Serum MDA, creatinine and urea, renal  MDA, gluthatione and catalase activity were measured. The data were analyzed by Mann-Whitney U test at the significant level of PResults: Oxygen therapy significantly improves serum creatinine and urea, preserve tubular volume density, reduce tubular necrosis in groups 4 and 6 compared to group 2. Oxygen therapy significantly increases renal catalase in groups 4 and 6 compared to group 2.   Conclusion: Pretreatment with normobaric hyperoxia and daily oxygen therapy improved gentamicin nephrotoxicity possibly via inhibition of lipid peroxidation and increasing the renal catalase activity but could not restore any parameter at the same levels as control group.

Linezolid-resistant clinical isolates of meticillin-resistant coagulase-negative staphylococci and Enterococcus faecium from China.

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Cai, Jia Chang; Hu, Yan Yan; Zhang, Rong; Zhou, Hong Wei; Chen, Gong-Xiang

2012-11-01

Seventeen meticillin-resistant coagulase-negative staphylococci (MRCoNS), including ten Staphylococcus capitis, four Staphylococcus cohnii, two Staphylococcus haemolyticus and one Staphylococcus sciuri, and an Enterococcus faecium isolate with various levels of linezolid resistance were isolated from intensive care units in a Chinese hospital. PFGE indicated that the four S. cohnii isolates belonged to a clonal strain, and that nine of the S. capitis isolates were indistinguishable (clone A1) and the other one was closely related (clone A2). A G2576T mutation was identified in domain V of the 23S rRNA gene in the E. faecium isolate. Besides the G2576T mutation, a novel C2104T mutation was detected in the nine clone A1 S. capitis isolates. The cfr gene was detected in all the staphylococci except an S. sciuri isolate, whose 23S rRNA gene contained the G2576T mutation. There was a clonal dissemination of linezolid-resistant MRCoNS in intensive care units of our hospital, and this is the first report, to our knowledge, of linezolid-resistant staphylococci and enterococci in China.

The effects of tertiary wastewater treatment on the prevalence of antimicrobial resistant bacteria

DEFF Research Database (Denmark)

Guardabassi, L.; Wong, Danilo Lo Fo; Dalsgaard, A.

2002-01-01

and anaerobically digested sludge by bacteriological counts on media selective for coliforms (MacConkey agar) and Acinetobacter spp. (Baumann agar). In addition, the level of antimicrobial susceptibility was determined by the disc-diffusion method in 442 Acinetobacter isolates identified by colony hybridisation......-resistant presumptive coliforms and Acinetobacter spp. in treated sewage and digested sludge were not significantly higher compared with raw sewage. On the contrary at one plant, statistically significant decreases were observed in the prevalence of ampicillin-resistant presumptive Acinetobacter spp. (p = 0.......0188) following sewage treatment, and in the prevalence of either ampicillin-resistant presumptive Acinetobacter spp. (p = 0.0013) or ampicillin- and gentamicin-resistant presumptive coliforms (p = 0.0273 and p = 0.0186) following sludge treatment. The results obtained by bacteriological counts were confirmed...

Neonatal sepsis in rural India: timing, microbiology and antibiotic resistance in a population-based prospective study in the community setting.

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Panigrahi, P; Chandel, D S; Hansen, N I; Sharma, N; Kandefer, S; Parida, S; Satpathy, R; Pradhan, L; Mohapatra, A; Mohapatra, S S; Misra, P R; Banaji, N; Johnson, J A; Morris, J G; Gewolb, I H; Chaudhry, R

2017-08-01

To examine the timing and microbiology of neonatal sepsis in a population-based surveillance in the Indian community setting. All live born infants in 223 villages of Odisha state were followed at home for 60 days. Suspect sepsis cases were referred to study hospitals for further evaluation including blood culture. Of 12 622 births, 842 were admitted with suspected sepsis of whom 95% were 4 to 60 days old. Culture-confirmed incidence of sepsis was 6.7/1000 births with 51% Gram negatives (Klebsiella predominating) and 26% Gram positives (mostly Staphylococcus aureus). A very high level of resistance to penicillin and ampicillin, moderate resistance to cephalosporins and extremely low resistance to Gentamicin and Amikacin was observed. The bacterial burden of sepsis in the Indian community is not high. Judicious choice of empiric antibiotics, antibiotic stewardship and alternate modalities should be considered for the management or prevention of neonatal sepsis in India.

Therapeutic efficacy of liposome-encapsulated gentamicin in rat Klebsiella pneumoniae pneumonia in relation to impaired host defense and low bacterial susceptibility to gentamicin.

NARCIS (Netherlands)

R.M. Schiffelers (Raymond); G. Storm (Gert); M.T. ten Kate (Marian); I.A.J.M. Bakker-Woudenberg (Irma)

2001-01-01

textabstractLong-circulating liposomes (LCL) may be used as targeted antimicrobial drug carriers as they localize at sites of infection. As a result, LCL-encapsulated gentamicin (LE-GEN) has demonstrated superior antibacterial activity over the free drug in a

Microbubble-Mediated Ultrasound Enhances the Lethal Effect of Gentamicin on Planktonic Escherichia coli

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Han-Xiao Zhu

2014-01-01

Full Text Available Previous research has found that low-intensity ultrasound enhanced the lethal effect of gentamicin on planktonic E. coli. We aimed to further investigate whether microbubble-mediated low-intensity ultrasound could further enhance the antimicrobial efficacy of gentamicin. The planktonic E. coli (ATCC 25922 was distributed to four different interventions: control (GCON, microbubble only (GMB, ultrasound only (GUS, and microbubble-mediated ultrasound (GMUS. Ultrasound was applied with 100 mW/cm2 (average intensity and 46.5 KHz, which presented no bactericidal activity. After 12 h, plate counting was used to estimate the number of bacteria, and bacterial micromorphology was observed with transmission electron microscope. The results showed that the viable counts of E. coli in GMUS were decreased by 1.01 to 1.42 log10 CFU/mL compared with GUS (P<0.01. The minimal inhibitory concentration (MIC of gentamicin against E. coli was 1 μg/mL in the GMUS and GUS groups, lower than that in the GCON and GMB groups (2 μg/mL. Transmission electron microscopy (TEM images exhibited more destruction and higher thickness of bacterial cell membranes in the GMUS than those in other groups. The reason might be the increased permeability of cell membranes for gentamicin caused by acoustic cavitation.

Bacterial Contamination of Iranian Paper Currency and Their Antibiotic Resistance Patterns

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Farzaneh Firoozeh

2017-11-01

Full Text Available Background: Paper currency is used in exchange for services, and thisis why the circulation of paper currency from person to person expandsmicroorganisms. Objectives:: Paper banknotes would be a vector for transmission of pathogenic microorganisms through handling. This study aimed to determine bacterial contamination of Iranian paper currencies in circulation and their antibiotic resistance patterns. Materials and Methods: In this study, 337 currency notes of different value were collected from markets, shops, restaurants, bus stations and banks in Kashan, Iran during April 2015 to March 2016. The currency notes transferred to microbiology laboratory and were tested for bacterial contamination using standard microbiological methods. Antibiotic resistance patterns of isolated bacteria were determined by disk diffusion method according to CLSI standards. The results and data were analyzed using descriptive statistics. Results: Of 337 currency notes, 262 (77.7% were identified with bacterial contamination. Bacteria isolated from currency notes were as follows: Bacillus spp 113 (43.1%, coagulase-negative Staphylococci 99 (37.7%, Escherichia coli 20 (7.6%, Enterococci species 14 (5.3%, Staphylococcus aureus 8 (3.1%, Klebsiella spp 4 (1.5%, Shigella species 2 (0.8%, Pseudomonas species 2 (0.8%. The most and least contaminated currency notes were 50000 and 500 Rials, respectively. The most resistance rates in gram negative rods were against nalidixicacid, and ampicillin. Also most resistance rates in Staphylococcus aureus, coagulase-negative Staphylococci and Enterococci species were against ampicillin, erythromycin and tetracycline. Conclusion: Our study revealed that the bacterial contamination among Iranian paper currency in circulation especially those obtained from certain sources including shops and bus stations is high and in most cases these bacterial isolates are antibiotic resistant strains.

Antibiotic usage and resistance in different regions of the Dutch community.

NARCIS (Netherlands)

Bruinsma, N.; Filius, P.M.; Smet, P.A.G.M. de; Degener, J.E.; Endtz, P.; Bogaard, A.E. van den; Stobberingh, E.E.

2002-01-01

Regional differences of antibiotic use and antibiotic resistance in the fecal indicator bacteria Escherichia coli and enterococci were determined in different cities in the south, west, and north of The Netherlands. In 1999, differences in antibiotic consumption were observed between the different

Antibiotic usage and resistance in different regions of the Dutch community

NARCIS (Netherlands)

Bruinsma, N; Filius, PMG; De Smet, PAGM; Degener, J; Endtz, P; Van den Bogaard, AE; Stobberingh, EE

2002-01-01

Regional differences of antibiotic use and antibiotic resistance in the fecal indicator bacteria Escherichia coli and enterococci were determined in different cities in the south, west, and north of The Netherlands. In 1999, differences in antibiotic consumption were observed between the different

Vaginal versus Obstetric Infection Escherichia coli Isolates among Pregnant Women: Antimicrobial Resistance and Genetic Virulence Profile.

Science.gov (United States)

Sáez-López, Emma; Guiral, Elisabet; Fernández-Orth, Dietmar; Villanueva, Sonia; Goncé, Anna; López, Marta; Teixidó, Irene; Pericot, Anna; Figueras, Francesc; Palacio, Montse; Cobo, Teresa; Bosch, Jordi; Soto, Sara M

2016-01-01

Vaginal Escherichia coli colonization is related to obstetric infections and the consequent development of infections in newborns. Ampicillin resistance among E. coli strains is increasing, which is the main choice for treating empirically many obstetric and neonatal infections. Vaginal E. coli strains are very similar to extraintestinal pathogenic E. coli with regards to the virulence factors and the belonging to phylogroup B2. We studied the antimicrobial resistance and the genetic virulence profile of 82 E. coli isolates from 638 vaginal samples and 63 isolated from endometrial aspirate, placental and amniotic fluid samples from pregnant women with obstetric infections. The prevalence of E. coli in the vaginal samples was 13%, which was significant among women with associated risk factors during pregnancy, especially premature preterm rupture of membranes (pinfections showed higher resistance levels than vaginal isolates, particularly for gentamicin (p = 0.001). The most prevalent virulence factor genes were those related to the iron uptake systems revealing clear targets for interventions. More than 50% of the isolates belonged to the virulent B2 group possessing the highest number of virulence factor genes. The ampicillin-resistant isolates had high number of virulence factors primarily related to pathogenicity islands, and the remarkable gentamicin resistance in E. coli isolates from women presenting obstetric infections, the choice of the most appropriate empiric treatment and clinical management of pregnant women and neonates should be carefully made. Taking into account host-susceptibility, the heterogeneity of E. coli due to evolution over time and the geographical area, characterization of E. coli isolates colonizing the vagina and causing obstetric infections in different regions may help to develop interventions and avoid the aetiological link between maternal carriage and obstetric and subsequent puerperal infections.

Empiric antibiotic therapy in urinary tract infection in patients with risk factors for antibiotic resistance in a German emergency department.

Science.gov (United States)

Bischoff, Sebastian; Walter, Thomas; Gerigk, Marlis; Ebert, Matthias; Vogelmann, Roger

2018-01-26

The aim of this study was to identify clinical risk factors for antimicrobial resistances and multidrug resistance (MDR) in urinary tract infections (UTI) in an emergency department in order to improve empirical therapy. UTI cases from an emergency department (ED) during January 2013 and June 2015 were analyzed. Differences between patients with and without resistances towards Ciprofloxacin, Piperacillin with Tazobactam (Pip/taz), Gentamicin, Cefuroxime, Cefpodoxime and Ceftazidime were analyzed with Fisher's exact tests. Results were used to identify risk factors with logistic regression modelling. Susceptibility rates were analyzed in relation to risk factors. One hundred thirty-seven of four hundred sixty-nine patients who met the criteria of UTI had a positive urine culture. An MDR pathogen was found in 36.5% of these. Overall susceptibility was less than 85% for standard antimicrobial agents. Logistic regression identified residence in nursing homes, male gender, hospitalization within the last 30 days, renal transplantation, antibiotic treatment within the last 30 days, indwelling urinary catheter and recurrent UTI as risk factors for MDR or any of these resistances. For patients with no risk factors Ciprofloxacin had 90%, Pip/taz 88%, Gentamicin 95%, Cefuroxime 98%, Cefpodoxime 98% and Ceftazidime 100% susceptibility. For patients with 1 risk factor Ciprofloxacin had 80%, Pip/taz 80%, Gentamicin 88%, Cefuroxime 78%, Cefpodoxime 78% and Ceftazidime 83% susceptibility. For 2 or more risk factors Ciprofloxacin drops its susceptibility to 52%, Cefuroxime to 54% and Cefpodoxime to 61%. Pip/taz, Gentamicin and Ceftazidime remain at 75% and 77%, respectively. We identified several risk factors for resistances and MDR in UTI. Susceptibility towards antimicrobials depends on these risk factors. With no risk factor cephalosporins seem to be the best choice for empiric therapy, but in patients with risk factors the beta-lactam penicillin Piperacillin with Tazobactam

Gentamicin-loaded poly(lactic-co-glycolic acid) microparticles for the prevention of maxillofacial and orthopedic implant infections

International Nuclear Information System (INIS)

Flores, Claudia; Degoutin, Stephanie; Chai, Feng; Raoul, Gwenael; Hornez, Jean-Chritophe; Martel, Bernard; Siepmann, Juergen; Ferri, Joel; Blanchemain, Nicolas

2016-01-01

Trauma and orthopedic surgery can cause infections as any open surgical procedures. Such complications occur in only1 to 5% of the cases, but the treatment is rather complicated due to bacterial biofilm formation and limited drug access to the site of infection upon systemic administration. An interesting strategy to overcome this type of complications is to prevent bacterial proliferation and biofilm formation via the local and controlled release of antibiotic drugs from the implant itself. Obviously, the incorporation of the drug into the implant should not affect the latter's biological and mechanical properties. In this context, we optimized the preparation process for gentamicin-loaded poly(lactic-co-glycolic acid) (PLGA) microparticles, which can be incorporated in the macropores of calcium phosphate-based bone substitutes. Microparticles were prepared using a double emulsion solvent extraction/evaporation technique. The processing parameters were optimized in order to provide an average microparticle size of about 60 μm, allowing for incorporation inside the macropores (100 μm) of the hydroxyapatite scaffold. Gentamicin-loaded PLGA microparticles showed a sustained release for 25–30 days and a rapid antibacterial activity due to a burst effect, the extent of which was controlled by the initial loading of the microparticles. SEM pictures revealed a highly porous microparticle structure, which can help to reduce the micro environmental pH drop and autocatalytic effects. The biological evaluation showed the cytocompatibility and non-hemolytic property of the microparticles, and the antibacterial activity against Staphylococcus aureus under the given conditions. - Highlights: • The optimization of microparticle preparation parameters allows to obtain a size compatible with the bone substitute porosity • PDL% has a direct impact on the burst effect, a control release of gentamicin was obtained • The incorporation of microparticles into the macroporosity

Gentamicin-loaded poly(lactic-co-glycolic acid) microparticles for the prevention of maxillofacial and orthopedic implant infections

Energy Technology Data Exchange (ETDEWEB)

Flores, Claudia [Univ. Lille, 59000 Lille (France); INSERM U1008, Controlled Drug Delivery Systems and Biomaterials, 59000 Lille (France); Degoutin, Stephanie [Univ. Lille, 59000 Lille (France); UMET, Ingénierie des Systèmes Polymères, Université de Lille 1, 59655 Villeneuve d' Ascq (France); Chai, Feng [Univ. Lille, 59000 Lille (France); INSERM U1008, Controlled Drug Delivery Systems and Biomaterials, 59000 Lille (France); Raoul, Gwenael [Univ. Lille, 59000 Lille (France); INSERM U1008, Controlled Drug Delivery Systems and Biomaterials, 59000 Lille (France); Service Chirurgie Maxillo-Faciale, CHRU de Lille, 59000 Lille (France); Hornez, Jean-Chritophe [Laboratoire des Matériaux Céramiques et Procédés Associés (LMCPA), Université de Valenciennes, 59300 Valenciennes (France); Martel, Bernard [Univ. Lille, 59000 Lille (France); UMET, Ingénierie des Systèmes Polymères, Université de Lille 1, 59655 Villeneuve d' Ascq (France); Siepmann, Juergen [Univ. Lille, 59000 Lille (France); INSERM U1008, Controlled Drug Delivery Systems and Biomaterials, 59000 Lille (France); Ferri, Joel [Univ. Lille, 59000 Lille (France); INSERM U1008, Controlled Drug Delivery Systems and Biomaterials, 59000 Lille (France); Service Chirurgie Maxillo-Faciale, CHRU de Lille, 59000 Lille (France); Blanchemain, Nicolas, E-mail: nicolas.blanchemain@univ-lille2.fr [Univ. Lille, 59000 Lille (France); INSERM U1008, Controlled Drug Delivery Systems and Biomaterials, 59000 Lille (France)

2016-07-01

Trauma and orthopedic surgery can cause infections as any open surgical procedures. Such complications occur in only1 to 5% of the cases, but the treatment is rather complicated due to bacterial biofilm formation and limited drug access to the site of infection upon systemic administration. An interesting strategy to overcome this type of complications is to prevent bacterial proliferation and biofilm formation via the local and controlled release of antibiotic drugs from the implant itself. Obviously, the incorporation of the drug into the implant should not affect the latter's biological and mechanical properties. In this context, we optimized the preparation process for gentamicin-loaded poly(lactic-co-glycolic acid) (PLGA) microparticles, which can be incorporated in the macropores of calcium phosphate-based bone substitutes. Microparticles were prepared using a double emulsion solvent extraction/evaporation technique. The processing parameters were optimized in order to provide an average microparticle size of about 60 μm, allowing for incorporation inside the macropores (100 μm) of the hydroxyapatite scaffold. Gentamicin-loaded PLGA microparticles showed a sustained release for 25–30 days and a rapid antibacterial activity due to a burst effect, the extent of which was controlled by the initial loading of the microparticles. SEM pictures revealed a highly porous microparticle structure, which can help to reduce the micro environmental pH drop and autocatalytic effects. The biological evaluation showed the cytocompatibility and non-hemolytic property of the microparticles, and the antibacterial activity against Staphylococcus aureus under the given conditions. - Highlights: • The optimization of microparticle preparation parameters allows to obtain a size compatible with the bone substitute porosity • PDL% has a direct impact on the burst effect, a control release of gentamicin was obtained • The incorporation of microparticles into the

High Levels of Transmitted HIV Drug Resistance in a Study in Papua New Guinea.

Science.gov (United States)

Lavu, Evelyn; Kave, Ellan; Mosoro, Euodia; Markby, Jessica; Aleksic, Eman; Gare, Janet; Elsum, Imogen A; Nano, Gideon; Kaima, Petronia; Dala, Nick; Gurung, Anup; Bertagnolio, Silvia; Crowe, Suzanne M; Myatt, Mark; Hearps, Anna C; Jordan, Michael R

2017-01-01

Papua New Guinea is a Pacific Island nation of 7.3 million people with an estimated HIV prevalence of 0.8%. ART initiation and monitoring are guided by clinical staging and CD4 cell counts, when available. Little is known about levels of transmitted HIV drug resistance in recently infected individuals in Papua New Guinea. Surveillance of transmitted HIV drug resistance in a total of 123 individuals recently infected with HIV and aged less than 30 years was implemented in Port Moresby (n = 62) and Mount Hagen (n = 61) during the period May 2013-April 2014. HIV drug resistance testing was performed using dried blood spots. Transmitted HIV drug resistance was defined by the presence of one or more drug resistance mutations as defined by the World Health Organization surveillance drug resistance mutations list. The prevalence of non-nucleoside reverse transcriptase inhibitor transmitted HIV drug resistance was 16.1% (95% CI 8.8%-27.4%) and 8.2% (95% CI 3.2%-18.2%) in Port Moresby and Mount Hagen, respectively. The prevalence of nucleoside reverse transcriptase inhibitor transmitted HIV drug resistance was 3.2% (95% CI 0.2%-11.7%) and 3.3% (95% CI 0.2%-11.8%) in Port Moresby and Mount Hagen, respectively. No protease inhibitor transmitted HIV drug resistance was observed. The level of non-nucleoside reverse transcriptase inhibitor drug resistance in antiretroviral drug naïve individuals recently infected with HIV in Port Moresby is amongst the highest reported globally. This alarming level of transmitted HIV drug resistance in a young sexually active population threatens to limit the on-going effective use of NNRTIs as a component of first-line ART in Papua New Guinea. To support the choice of nationally recommended first-line antiretroviral therapy, representative surveillance of HIV drug resistance among antiretroviral therapy initiators in Papua New Guinea should be urgently implemented.

Activity of daptomycin alone and in combination with rifampin and gentamicin against Staphylococcus aureus assessed by time-kill methodology.

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Credito, Kim; Lin, Gengrong; Appelbaum, Peter C

2007-04-01

The synergistic effects of daptomycin plus gentamicin or rifampin were tested against 50 Staphylococcus aureus strains, with daptomycin MICs ranging between 0.25 and 8 microg/ml. Daptomycin sub-MICs combined with gentamicin concentrations lower than the MIC yielded synergy in 34 (68%) of the 50 strains. Daptomycin combined with rifampin yielded synergy in one vancomycin-intermediate S. aureus strain only, and virtually all synergy occurred between daptomycin and gentamicin.

RESISTENCIA A LOS ANTIBIÓTICOS EN CEPAS DE KLEBSIELLA PNEUMONIAE, SERRATIA SPP. Y ACINETOBACTER SPP.AISLADAS DE PACIENTES CON INFECCIÓN DEL TRACTO URINARIO - LIMA, PERU

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Luján Roca DA

2013-01-01

Full Text Available INFECTION - LIMA, PERU Introduction: Urinary tract infection (UTI is one of the most common infections in clinical practice. Gram negative bacteria as Klebsiella pneumoniae, Serratia spp. and Acinetobacter spp. can cause UTI. Objective: To study antibiotic resistance in K. pneumoniae, Serratia spp. and Acinetobacter spp. strains isolated from UTI Material and methods: Urine cultures were collected from January 2003 to December 2003. Identification of isolated bacteria included biochemical characteristics. Bauer-Kirby disc diffusion test was performed. Results: A total of 106 strains were evaluated (41 of K. pneumoniae, 28 of Serratia spp. and 37 of Acinetobacter spp.. Among K. pneumoniae isolates resistance to ampicillin (83% was remarkable. The Serratia spp. isolates displayed a high level of resistance to nalidixic acid (79% and gentamicin (75%. In Acinetobacter spp. isolates high resistance rates were observed against amikacin (81%, gentamicin (67% and trimethoprim/sulfamethoxazole(71%. Conclusions: In general, antibiotic resistance patterns were high. Acinetobacter spp. showed elevated resistance rates (>50% against antibiotics included.

Prevalence of multiple drug resistant Streptococcus suis in and around Guwahati, India

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Mrinalee Devi

2017-05-01

Full Text Available Aim: This study was conducted to determine the prevalence and antimicrobial susceptibility of Streptococcus suis and their resistance patterns isolated from both clinically healthy carriers and diseased pigs in and around Guwahati, Assam, India. Materials and Methods: A total of 497 samples were collected during October, 2012, to April, 2014, from clinically healthy (n=67 and diseased (n=230 pigs of varying age and either sex maintained under organized and unorganized farming systems. Samples were processed for isolation and identification of S. suis by biochemical characterization and polymerase chain reaction targeting the housekeeping gene glutamate dehydrogenase. In vitro antimicrobial susceptibility of the recovered isolates against nine antibiotic groups comprising 17 antimicrobial agents was studied by standard method. Results: Of the 497 samples examined, 7 (1.41% isolates were confirmed to be S. suis of which 5 (1.87% and 2 (0.87% were derived from clinically healthy and diseased pigs, respectively. All the isolates were susceptible to gentamicin, amikacin, and erythromycin (100% followed by the penicillin group and enrofloxacin (85.71%, ceftriaxone, doxycycline HCL, ofloxacin and chloramphenicol (71.43%, to kanamycin, clindamycin and co-trimoxazole (42.85%. The isolates showed least susceptibility to cefalexin, tetracycline and streptomycin (28.57%. All the five S. suis isolates from clinically healthy pigs were susceptible to penicillin G, amoxyclav, doxycycline HCl, gentamicin, amikacin and erythromycin, 80.00% isolates susceptible to ampicillin, enrofloxacin and ofloxacin, 60.00% to ceftriaxone, kanamycin and chloramphenicol, 40% to cefalexin, tetracycline, clindamycin and co-trimoxazole, respectively. Only 20.00% isolates were susceptible to streptomycin. Both the isolates recovered from diseased pigs were susceptible to ampicillin, ceftriaxone, gentamicin, amikacin, enrofloxacin, erythromycin, and clindamycin. On the other hand

Transgressive segregation for very low and high levels of basal resistance to powdery mildew in barley

NARCIS (Netherlands)

Aghnoum, R.; Niks, R.E.

2011-01-01

Basal resistance of barley to powdery mildew is a quantitatively inherited trait that limits the growth and sporulation of barley powdery mildew pathogen by a non-hypersensitive mechanism of defense. Two experimental barley lines were developed with a very high (ErBgh) and low (EsBgh) level of basal

EFFICACY OF GENTAMICIN AFTER INTRAYOLK ADMINISTRATION IN EXPERIMENT ALLY INDUCED OMPHALITIS IN BROILER CHICKS

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Muhammad Ashraf, Qamar Arif and Kashif Aziz Khan1

2002-04-01

Full Text Available A study was conducted to observe the effect of intrayolk injection of gentamicin on experimentally induced omphalitis in broiler chicks. Escherichia coli was injected into yolk sac to induce omphalitis and treatment was done by intrayolk injection of gentamicin. Results showed that mortality decreased and feed intake increased after treatment, Intrayolk injection of antibiotics is suggested as an alternative to oral administration for the treatment of omphalitis in chicks.

["Look to Norway"--but for how long?].

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Haug, Jon Birger; Raastad, Ragnhild; Berild, Dag

2010-08-12

Internationally, Norway receives positive attention mainly in the context of Winter Olympics or peace initiatives. However, an Associated Press article recently suggested that the Norwegian health care system had "found the Solution to Killer Superbug". Furthermore, Norway was proclaimed "The Most Infection Free Country in the World". What my be the reality behind such headlines, and how shall we as a nation maintain a favourable situation? Physicians in Scandinavian countries and the Netherlands have a long tradition for modest prescription of antibiotics, and are trained to use agents with a narrow antimicrobial spectre whenever possible. This is probably the main reason why these countries have had less antibiotic resistance than others. The number of antibiotics marketed in a country correlates positively with total drug consumption. Until 1992, Norwegian authorities could reject marketing of new compounds if national experts found no medical need for them. The foresight of senior colleagues has led to the number of marketed antibiotics in Norway, even today, being 10-fold lower than in some other European countries. The national surveillance programme, NORM, reports antimicrobial resistance in human pathogens on an annual basis. For example, national levels of MRSA and ESBL-producing Enterobacteriaceae are still very low whereas ampicillin and ciprofloxacin resistance in E coli and high- level gentamicin resistance in enterococci cause some concern. Norway has well-established epidemiological surveillance systems in the fields of microbiology and infectious diseases. Nevertheless, more knowledge is needed on how antibiotics are used in hospitals. Two national strategic plans (since 2003) have emphasized the explicit importance of antibiotic surveillance to counteract future antibiotic resistance problems. To fulfil national ambitions, there is an urgent need for economic grants to this field; the human resources are there and as eager to start as Olympic

Intraoperative intra-articular injection of gentamicin: will it decrease the risk of infection in total shoulder arthroplasty?

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Lovallo, Jeffrey; Helming, Jarrett; Jafari, S Mehdi; Owusu-Forfie, Afia; Donovan, Skye; Minnock, Christopher; Adib, Farshad

2014-09-01

Deep infection is a debilitating complication after shoulder arthroplasty. Intra-articular injection of antibiotic can give a higher concentration compared with intravenous administration. We hypothesized that a group of patients given an intra-articular, intraoperative injection of gentamicin would report a lower infection rate than a group without local antibiotics. Between 2005 and 2011, the senior author performed 507 shoulder arthroplasties. We retrospectively reviewed all of those cases. All patients were administered systemic prophylactic antibiotics. Beginning in June 2007, patients were also injected with 160 mg of gentamicin in the glenohumeral joint at the end of their surgery. Patient records were examined for preexisting medical conditions, type of surgery, and presence of infection. Patients receiving surgery before 2007 were compared with those after to determine the effect of prophylactic gentamicin administration in preventing deep infection associated with surgery. All patients were observed for a minimum of 1 year. Of the 507 surgeries, 164 were performed before 2007 (without intra-articular injection of gentamicin; group A) and 343 were performed with addition of gentamicin (group B). In group A, 5 patients presented with infection (3.0%) compared with 1 in group B (0.29%). The gender, mean age, mean body mass index, and prevalence of comorbidities were similar between the groups. The data from this study support the conclusion that intra-articular intraoperative gentamicin administration may reduce postoperative infection. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Drug Resistance Mechanisms of Mycoplasma pneumoniae to Macrolide Antibiotics

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Xijie Liu

2014-01-01

Full Text Available Throat swabs from children with suspected Mycoplasma pneumoniae (M. pneumoniae infection were cultured for the presence of M. pneumoniae and its species specificity using the 16S rRNA gene. Seventy-six M. pneumoniae strains isolated from 580 swabs showed that 70 were erythromycin resistant with minimum inhibitory concentrations (MIC around 32–512 mg/L. Fifty M. pneumoniae strains (46 resistant, 4 sensitive were tested for sensitivity to tetracycline, ciprofloxacin, and gentamicin. Tetracycline and ciprofloxacin had some effect, and gentamicin had an effect on the majority of M. pneumoniae strains. Domains II and V of the 23S rRNA gene and the ribosomal protein L4 and L22 genes, both of which are considered to be associated with macrolide resistance, were sequenced and the sequences were compared with the corresponding sequences in M129 registered with NCBI and the FH strain. The 70 resistant strains all showed a 2063 or 2064 site mutation in domain V of the 23S rRNA but no mutations in domain II. Site mutations of L4 or L22 can be observed in either resistant or sensitive strains, although it is not known whether this is associated with drug resistance.

Extracellular gentamicin reduces the activity of connexin hemichannels and interferes with purinergic Ca2+ signaling in HeLa cells

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Figueroa, Vania A.; Retamal, Mauricio A.; Cea, Luis A.; Salas, José D.; Vargas, Aníbal A.; Verdugo, Christian A.; Jara, Oscar; Martínez, Agustín D.; Sáez, Juan C.

2014-01-01

Gap junction channels (GJCs) and hemichannels (HCs) are composed of protein subunits termed connexins (Cxs) and are permeable to ions and small molecules. In most organs, GJCs communicate the cytoplasm of adjacent cells, while HCs communicate the intra and extracellular compartments. In this way, both channel types coordinate physiological responses of cell communities. Cx mutations explain several genetic diseases, including about 50% of autosomal recessive non-syndromic hearing loss. However, the possible involvement of Cxs in the etiology of acquired hearing loss remains virtually unknown. Factors that induce post-lingual hearing loss are diverse, exposure to gentamicin an aminoglycoside antibiotic, being the most common. Gentamicin has been proposed to block GJCs, but its effect on HCs remains unknown. In this work, the effect of gentamicin on the functional state of HCs was studied and its effect on GJCs was reevaluated in HeLa cells stably transfected with Cxs. We focused on Cx26 because it is the main Cx expressed in the cochlea of mammals where it participates in purinergic signaling pathways. We found that gentamicin applied extracellularly reduces the activity of HCs, while dye transfer across GJCs was not affected. HCs were also blocked by streptomycin, another aminoglycoside antibiotic. Gentamicin also reduced the adenosine triphosphate release and the HC-dependent oscillations of cytosolic free-Ca2+ signal. Moreover, gentamicin drastically reduced the Cx26 HC-mediated membrane currents in Xenopus laevis oocytes. Therefore, the extracellular gentamicin-induced inhibition of Cx HCs may adversely affect autocrine and paracrine signaling, including the purinergic one, which might partially explain its ototoxic effects. PMID:25237294

Antibiotics and common antibacterial biocides stimulate horizontal transfer of resistance at low concentrations.

Science.gov (United States)

Jutkina, J; Marathe, N P; Flach, C-F; Larsson, D G J

2018-03-01

There is a rising concern that antibiotics, and possibly other antimicrobial agents, can promote horizontal transfer of antibiotic resistance genes. For most types of antimicrobials their ability to induce conjugation below minimal inhibitory concentrations (MICs) is still unknown. Our aim was therefore to explore the potential of commonly used antibiotics and antibacterial biocides to induce horizontal transfer of antibiotic resistance. Effects of a wide range of sub-MIC concentrations of the antibiotics cefotaxime, ciprofloxacin, gentamicin, erythromycin, sulfamethoxazole, trimethoprim and the antibacterial biocides chlorhexidine digluconate, hexadecyltrimethylammoniumchloride and triclosan were investigated using a previously optimized culture-based assay with a complex bacterial community as a donor of mobile resistance elements and a traceable Escherichia coli strain as a recipient. Chlorhexidine (24.4μg/L), triclosan (0.1mg/L), gentamicin (0.1mg/L) and sulfamethoxazole (1mg/L) significantly increased the frequencies of transfer of antibiotic resistance whereas similar effects were not observed for any other tested antimicrobial compounds. This corresponds to 200 times below the MIC of the recipient for chlorhexidine, 1/20 of the MIC for triclosan, 1/16 of the MIC for sulfamethoxazole and right below the MIC for gentamicin. To our best knowledge, this is the first study showing that triclosan and chlorhexidine could stimulate the horizontal transfer of antibiotic resistance. Together with recent research showing that tetracycline is a potent inducer of conjugation, our results indicate that several antimicrobials including both common antibiotics and antibacterial biocides at low concentrations could contribute to antibiotic resistance development by facilitating the spread of antibiotic resistance between bacteria. Copyright © 2017 Elsevier B.V. All rights reserved.

High prevalence and antimicrobial resistance of urinary tract infection isolates in febrile young children without localizing signs in Taiwan.

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Wu, Chang-Teng; Lee, Hao-Yuan; Chen, Chyi-Liang; Tuan, Pao-Lan; Chiu, Cheng-Hsun

2016-04-01

Antimicrobial susceptibility and prevalence of pediatric urinary tract infection (UTI) is very useful for pediatricians in selecting effective antibiotics in time to improve outcomes in patients. This study aimed to determine the prevalence rate, bacterial distribution, and antimicrobial susceptibility of UTI in febrile young children at a teaching hospital in northern Taiwan. From January 2011 to December 2011, all urinary isolates from suspected cases of UTI in febrile young children aged from 1 day to 36 months visiting the Pediatric Emergency Room of Chang Gung Children's Hospital, Taoyuan, Taiwan were identified by conventional methods. Antibiotic susceptibility was determined according to the Clinical and Laboratory Standards Institute. A total of 5470 (78%) from 7009 eligible children were enrolled in the study, and 619 (11.3%) had a diagnosis of UTI. The most prevalent bacterium was Escherichia coli (68%) followed by Klebsiella pneumoniae (8.1%) and Proteus mirabilis (6.8%). Ampicillin, piperacillin, and trimethoprim-sulfamethoxazole (TMP-SMX) showed a higher resistance rate in the three predominant bacteria. All tested bacteria showed higher resistance to ampicillin (79.3%) and TMP-SMX (44.1%), and lower resistance to cefazolin (17.7%) and gentamicin (13.0%). Fourteen percent of the isolates produced extended spectrum β-lactamase (ESBL), among which 93.33% were E. coli isolates. The overall prevalence of UTI in this study was higher than previously reported in febrile children. Higher antimicrobial resistance was found in ampicillin and TMP-SMX. Among commonly used antibiotics, cefazolin and gentamicin are recommended to treat UTI in febrile children aged < 3 years without localizing signs. Copyright © 2015. Published by Elsevier B.V.

Evolution of a double amino acid substitution in the 5-enolpyruvylshikimate-3-phosphate synthase in Eleusine indica conferring high-level glyphosate resistance.

Science.gov (United States)

Yu, Qin; Jalaludin, Adam; Han, Heping; Chen, Ming; Sammons, R Douglas; Powles, Stephen B

2015-04-01

Glyphosate is the most important and widely used herbicide in world agriculture. Intensive glyphosate selection has resulted in the widespread evolution of glyphosate-resistant weed populations, threatening the sustainability of this valuable once-in-a-century agrochemical. Field-evolved glyphosate resistance due to known resistance mechanisms is generally low to modest. Here, working with a highly glyphosate-resistant Eleusine indica population, we identified a double amino acid substitution (T102I+P106S [TIPS]) in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene in glyphosate-resistant individuals. This TIPS mutation recreates the biotechnology-engineered commercial first generation glyphosate-tolerant EPSPS in corn (Zea mays) and now in other crops. In E. indica, the naturally evolved TIPS mutants are highly (more than 180-fold) resistant to glyphosate compared with the wild type and more resistant (more than 32-fold) than the previously known P106S mutants. The E. indica TIPS EPSPS showed very high-level (2,647-fold) in vitro resistance to glyphosate relative to the wild type and is more resistant (600-fold) than the P106S variant. The evolution of the TIPS mutation in crop fields under glyphosate selection is likely a sequential event, with the P106S mutation being selected first and fixed, followed by the T102I mutation to create the highly resistant TIPS EPSPS. The sequential evolution of the TIPS mutation endowing high-level glyphosate resistance is an important mechanism by which plants adapt to intense herbicide selection and a dramatic example of evolution in action. © 2015 American Society of Plant Biologists. All Rights Reserved.

Effect of pulsed ultrasound in combination with gentamicin on bacterial killing of biofilms on bone cements in vivo

Science.gov (United States)

Ensing, G.T.; Roeder, B.L.; Nelson, J.L.; van Horn, J.R.; van der Mei, H.C.; Busscher, H.J.; Pitt, W.G.

2008-01-01

Aim The aim of this study is to investigate whether pulsed ultrasound in combination with gentamicin yields increased killing of bacterial biofilms on bone cements in vivo. Methods and Results Bacterial survival on bone cement in the presence and absence of ultrasound was compared in a rabbit model. Two bone cement samples with E. coli ATCC 10798 biofilm were implanted in a total of nine rabbits. In two groups bone cement disks loaded with gentamicin were used, and in one group unloaded bone cement disks in combination with systemically administered gentamicin were used. Pulsed ultrasound with a mean acoustic intensity of 167 mW cm−2 and a maximum acoustic intensity of 500 mW cm−2 was applied from 24 h till 72 h post surgery on one of the two implanted disks. After euthanization, the bacteria removed from the disk were quantified. Application of ultrasound, combined with gentamicin, reduced the biofilm in all three groups varying between 58 to 69% compared to the negative control. Ultrasound proved to be safe with respect to creating skin lesions. Conclusions Ultrasound resulted in an tendency of improved efficacy of gentamicin, either applied locally or systemically. Significance and impact of Study This study implies that ultrasound could improve the prevention of infection, especially because the biomaterials, gentamicin and ultrasound used in this model are all in clinical usage, but not yet combined in clinical practice. PMID:16108785

Impact of erosion and accretion on the distribution of enterococci in beach sands.

Science.gov (United States)

Gast, Rebecca J; Gorrell, Levi; Raubenheimer, Britt; Elgar, Steve

2011-09-15

Bacterial pathogens in coastal sediments may pose a health risk to users of beaches. Although recent work shows that beach sands harbor both indicator bacteria and potential pathogens, it is not known how deep within beach sands the organisms may persist nor if they may be exposed during natural physical processes. In this study, sand cores of approximately 1 m depth were collected at three sites across the beach face in Kitty Hawk, North Carolina before, during and after large waves from an offshore hurricane. The presence of DNA from the fecal indicator bacterium Enterococci was detected in subsamples at different depths within the cores by PCR amplification. Erosion and accretion of beach sand at the three sites also was determined for each sampling day. The results indicate that ocean beach sands with persisting enterococci signals could be exposed and redistributed when wind, waves, and currents cause beach erosion or accretion.

Cluster of Neisseria gonorrhoeae Isolates With High-level Azithromycin Resistance and Decreased Ceftriaxone Susceptibility, Hawaii, 2016.

Science.gov (United States)

Katz, Alan R; Komeya, Alan Y; Kirkcaldy, Robert D; Whelen, A Christian; Soge, Olusegun O; Papp, John R; Kersh, Ellen N; Wasserman, Glenn M; O'Connor, Norman P; O'Brien, Pamela S; Sato, Douglas T; Maningas, Eloisa V; Kunimoto, Gail Y; Tomas, Juval E

2017-09-15

The Centers for Disease Control and Prevention (CDC) currently recommends dual therapy with ceftriaxone and azithromycin for gonorrhea to ensure effective treatment and slow emergence of antimicrobial resistance. Since 2013, the prevalence of reduced azithromycin susceptibility increased in the United States; however, these strains were highly susceptible to cephalosporins. We identified a cluster of Neisseria gonorrhoeae isolates with high-level azithromycin resistance, several of which also demonstrated decreased ceftriaxone susceptibility. Eight N. gonorrhoeae isolates collected from 7 patients on Oahu, Hawaii, seen 21 April 2016 through 10 May 2016 underwent routine Etest antimicrobial susceptibility testing by the Hawaii Department of Health. All demonstrated elevated azithromycin minimum inhibitory concentrations (MICs) >256 μg/mL and elevated ceftriaxone MICs (≥0.125 μg/mL). Isolates were sent to the University of Washington and CDC for confirmatory agar dilution testing; sequence data were sent to CDC for analysis. All patients were interviewed and treated, and when possible, partners were interviewed, tested, and treated. All isolates had azithromycin MICs >16 µg/mL and 5 had ceftriaxone MICs = 0.125 µg/mL by agar dilution. All isolates were β-lactamase positive and were resistant to penicillin, tetracycline, and ciprofloxacin. Genomic analysis revealed genetic relatedness. No patients reported recent travel or antibiotic use, and no male patients reported male sex partners. All patients were successfully treated. This cluster of genetically related gonococcal isolates with decreased ceftriaxone susceptibility and high-level azithromycin resistance may bring the threat of treatment failure in the United States with the current recommended dual therapy one step closer. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Protective Effect of Carvacrol on Renal Functional and Histopathological Changes in Gentamicin-Induced-Nephrotoxicity in Rats

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Hassan Ahmadvand

2016-04-01

Full Text Available Background Nephrotoxicity is one of the most important side effects of the use of gentamicin sulphate (GS resulted in reactive oxygen species generation. Antioxidant compounds played effective roles in reduction of renal injuries caused by using of gentamicin. Carvacrol is a strong antioxidant compound. Objectives The aim of this study is to explore the effect of carvacrol inhibition in lesions of gentamicin-induced nephrotoxicity. Materials and Methods In this experimental study, 32 male mature Sprague-Dawley rats were divided into 4 groups of 8; group1: control, group 2 sham received daily carvacrol injection (74 mg/kg for 12 days, group 3 received daily GS injection (100 mg/kg for 12 days, group 4 received daily GS (100 mg/kg and carvacrol (74 mg/kg for 12 days. After 12 days, rats were anaesthetized, blood sample were obtained and kidneys were removed then stained with hematoxylin and eosin method and then were studied histophatologically. Serum creatinine and urea were measured. Results Flow treatment of nephrotoxic animals with carvacrol could significantly inhibit leukocyte infiltration (9.42% and tubular necrosis (38.18% in comparison with the nephrotoxic untreated group. Carvacrol significantly decreased the levels of urea and creatinine in treated group compared with the nephrotoxic untreated group. Conclusions The findings showed that carvacrol alleviates loss of leukocyte infiltration (9.42% and tubular necrosis and exerts beneficial effects on kidney function test in nephrotoxic group.

Old and New Glycopeptide Antibiotics: Action and Resistance

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Elisa Binda

2014-11-01

Full Text Available Glycopeptides are considered antibiotics of last resort for the treatment of life-threatening infections caused by relevant Gram-positive human pathogens, such as Staphylococcus aureus, Enterococcus spp. and Clostridium difficile. The emergence of glycopeptide-resistant clinical isolates, first among enterococci and then in staphylococci, has prompted research for second generation glycopeptides and a flurry of activity aimed at understanding resistance mechanisms and their evolution. Glycopeptides are glycosylated non-ribosomal peptides produced by a diverse group of soil actinomycetes. They target Gram-positive bacteria by binding to the acyl-D-alanyl-D-alanine (D-Ala-D-Ala terminus of the growing peptidoglycan on the outer surface of the cytoplasmatic membrane. Glycopeptide-resistant organisms avoid such a fate by replacing the D-Ala-D-Ala terminus with D-alanyl-D-lactate (D-Ala-D-Lac or D-alanyl-D-serine (D-Ala-D-Ser, thus markedly reducing antibiotic affinity for the cellular target. Resistance has manifested itself in enterococci and staphylococci largely through the expression of genes (named van encoding proteins that reprogram cell wall biosynthesis and, thus, evade the action of the antibiotic. These resistance mechanisms were most likely co-opted from the glycopeptide producing actinomycetes, which use them to avoid suicide during antibiotic production, rather than being orchestrated by pathogen bacteria upon continued treatment. van-like gene clusters, similar to those described in enterococci, were in fact identified in many glycopeptide-producing actinomycetes, such as Actinoplanes teichomyceticus, which produces teicoplanin, and Streptomyces toyocaensis, which produces the A47934 glycopeptide. In this paper, we describe the natural and semi-synthetic glycopeptide antibiotics currently used as last resort drugs for Gram-positive infections and compare the van gene-based strategies of glycopeptide resistance among the pathogens and

Species distribution, virulence factors, and antimicrobial resistance of Acinetobacter spp. isolates from dogs and cats: a preliminary study.

Science.gov (United States)

Kimura, Yui; Harada, Kazuki; Shimizu, Takae; Sato, Tomomi; Kajino, Akari; Usui, Masaru; Tamura, Yutaka; Tsuyuki, Yuzo; Miyamoto, Tadashi; Ohki, Asami; Watarai, Masahisa

2018-05-12

We investigated the prevalence of virulence factors and antimicrobial resistance among 67 Acinetobacter spp. isolates, consisting of 21 Acinetobacter baumannii and 46 non-baumannii Acinetobacter from companion animals. The PCR analysis showed that the most prevalent virulence gene was afa/draBC (29.9%), followed by papC (22.4%) and cvaC (20.9%). Antimicrobial susceptibility testing revealed that resistance to gentamicin (14.9%) and ciprofloxacin (11.9%) was relatively prevalent. Five gentamicin- and/or ciprofloxacin-resistant A. baumannii strains were assigned to ST25, ST149, ST164, ST203, and ST1198. All ciprofloxacin-resistant isolates harbored point mutations in gyrA and/or parC. This is the first preliminary monitoring of animal-origin Acinetobacter spp. in Japan. © 2018 The Societies and John Wiley & Sons Australia, Ltd.

Evolution of a Double Amino Acid Substitution in the 5-Enolpyruvylshikimate-3-Phosphate Synthase in Eleusine indica Conferring High-Level Glyphosate Resistance1

Science.gov (United States)

Yu, Qin; Jalaludin, Adam; Han, Heping; Chen, Ming; Sammons, R. Douglas; Powles, Stephen B.

2015-01-01

Glyphosate is the most important and widely used herbicide in world agriculture. Intensive glyphosate selection has resulted in the widespread evolution of glyphosate-resistant weed populations, threatening the sustainability of this valuable once-in-a-century agrochemical. Field-evolved glyphosate resistance due to known resistance mechanisms is generally low to modest. Here, working with a highly glyphosate-resistant Eleusine indica population, we identified a double amino acid substitution (T102I + P106S [TIPS]) in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene in glyphosate-resistant individuals. This TIPS mutation recreates the biotechnology-engineered commercial first generation glyphosate-tolerant EPSPS in corn (Zea mays) and now in other crops. In E. indica, the naturally evolved TIPS mutants are highly (more than 180-fold) resistant to glyphosate compared with the wild type and more resistant (more than 32-fold) than the previously known P106S mutants. The E. indica TIPS EPSPS showed very high-level (2,647-fold) in vitro resistance to glyphosate relative to the wild type and is more resistant (600-fold) than the P106S variant. The evolution of the TIPS mutation in crop fields under glyphosate selection is likely a sequential event, with the P106S mutation being selected first and fixed, followed by the T102I mutation to create the highly resistant TIPS EPSPS. The sequential evolution of the TIPS mutation endowing high-level glyphosate resistance is an important mechanism by which plants adapt to intense herbicide selection and a dramatic example of evolution in action. PMID:25717039

Detection and linkage to mobile genetic elements of tetracycline resistance gene tet(M) in Escherichia coli isolates from pigs

DEFF Research Database (Denmark)

Jurado-Rabadan, Sonia; de la Fuente, Ricardo; Ruiz-Santa-Quiteria, Jose A.

2014-01-01

Background: In Escherichia coli the genes involved in the acquisition of tetracycline resistance are mainly tet(A) and tet(B). In addition, tet(M) is the most common tetracycline resistance determinant in enterococci and it is associated with conjugative transposons and plasmids. Although tet......(M) has been identified in E. coli, to our knowledge, there are no previous reports studying the linkage of the tet(M) gene in E. coli to different mobile genetic elements. The aim of this study was to determine the occurrence of tet(A), tet(B), and tet(M) genes in doxycycline-resistant E. coli isolates...... from pigs, as well as the detection of mobile genetic elements linked to tet(M) in E. coli and its possible transfer from enterococci. Results: tet(A) was the most frequently detected gene (87.9%) in doxycycline-resistant isolates. tet(M) was found in 13.1% E. coli isolates. The tet(M) gene...

A treatment plant receiving waste water from multiple bulk drug manufacturers is a reservoir for highly multi-drug resistant integron-bearing bacteria.

Directory of Open Access Journals (Sweden)

Nachiket P Marathe

Full Text Available The arenas and detailed mechanisms for transfer of antibiotic resistance genes between environmental bacteria and pathogens are largely unclear. Selection pressures from antibiotics in situations where environmental bacteria and human pathogens meet are expected to increase the risks for such gene transfer events. We hypothesize that waste-water treatment plants (WWTPs serving antibiotic manufacturing industries may provide such spawning grounds, given the high bacterial densities present there together with exceptionally strong and persistent selection pressures from the antibiotic-contaminated waste. Previous analyses of effluent from an Indian industrial WWTP that processes waste from bulk drug production revealed the presence of a range of drugs, including broad spectrum antibiotics at extremely high concentrations (mg/L range. In this study, we have characterized the antibiotic resistance profiles of 93 bacterial strains sampled at different stages of the treatment process from the WWTP against 39 antibiotics belonging to 12 different classes. A large majority (86% of the strains were resistant to 20 or more antibiotics. Although there were no classically-recognized human pathogens among the 93 isolated strains, opportunistic pathogens such as Ochrobactrum intermedium, Providencia rettgeri, vancomycin resistant Enterococci (VRE, Aerococcus sp. and Citrobacter freundii were found to be highly resistant. One of the O. intermedium strains (ER1 was resistant to 36 antibiotics, while P. rettgeri (OSR3 was resistant to 35 antibiotics. Class 1 and 2 integrons were detected in 74/93 (80% strains each, and 88/93 (95% strains harbored at least one type of integron. The qPCR analysis of community DNA also showed an unprecedented high prevalence of integrons, suggesting that the bacteria living under such high selective pressure have an appreciable potential for genetic exchange of resistance genes via mobile gene cassettes. The present study provides