Antibiotic-resistant Enterobacteriaceae Research Articles

Coordinated surveillance of the multi drug resistant organisms in a French University Hospital: Results since 2013

Introduction The control of the cross-transmission of multi drug resistant organisms (MDRO) is a major concern in the healthcare centers. That is the purpose of one of the axes of the French national program of prevention of healthcare-associated infections (Propias). To adapt the recommendations, a French multicenter university hospital started a coordinated and standardized surveillance of MDRO since 2013. The objective of the study is to know the global incidence rate of MDROs and to follow this rate along time. Methods An active standardized surveillance of MDRO was carried out in a university hospital of about 6000 beds. The methodology was based on the French national MDRO's surveillance network (BMR-RAISIN). All methicillin resistant Staphylococcus aureus (MRSA), and extended spectrum beta-lactamase Enterobacteriaceae (ESBLE) detected in clinical specimen performed between April 1, and June 30, in 2013, 2015, and 2017, in the hospitalized patients (in conventional ward or week hospitalization) were included. Screening for colonization and environment samples were excluded. To describe the population with MDROs, we collected data on patient characteristics, specimen sample site, acquired or imported, infection or colonization, ESBLE species, resistance profile for certain antibiotics markers. To calculate the incidence rates, the number of hospitalization days was collected for each period of surveillance. Results For the 3 surveillance periods, a total of 1191 MDRO were included, distributed in 989 ESBLEs (93.04%) and 202 MRSAs (16.96%). The main ESBLE species were Escherichia coli (41.6%), Klebsiella pneumoniae (31.6%) and Enterobacter cloacae (11.4%). The proportion of E. coli decreased along time to the detriment of the other Enterobacteriaceae species, in particular for imported ESBLE (P = 0.0304), while the time evolution was not statistically significant for acquired ESBLEs (P = 0.0555). There were 506 acquired MDROs (42.5%) and 651 imported (54.7%). The most frequent sample types were urine samples (N = 608, 52.9%), respiratory specimens (N = 185, 16.1%) and bloodstream specimens (N = 123, 10.7%). MDROs were responsible of 786 infections among the 1108 for which the information was available (70.9%). Fifteen ESBLEs among 952 were imipenem-resistant (1.6%), and 54 among 868 were ertapenem-resistant (6.2%). The proportion of ertapenem resistant ESBLE was 2-fold increased between 2013 and 2017, from 4.3% to 8.4% (P = 0.06). A 20% > decreased of the incidence rate of MRSA was observed between 2013 and 2017: from 0.25/1000 hospitalization-days in 2013, to 0.17 in 2015, and 0.20 in 2017. This decrease was higher in imported MRSA group. A 62.7% > increased of the ESBLE incidence rate was observed, from 0.83/1000 hospitalization-days in 2013 and 2015 to 1.35 in 2017. This increase was observed both for the imported and acquired ESBLE but was higher for the imported ones. Conclusions The implementation of this surveillance allowed the University hospital to know its global incidence rate of MRSA and ESBLE, and to propose straightaway coordinated prevention measures. We observed over the 3 periods of surveillance a decrease in the MRSA incidence and an increase in the ESBLE incidence. These results are coherent with the national network data. We observed also an increase in the proportion of ertapenem-resistant ESBLE. These data should be construed in the light of the change of the national epidemiology of the antibiotic resistance in Enterobacteriaceae, and particularly the increasing number of episodes of carbapenem-producing Enterobacteriaceae which the university hospital have to manage. These data suggest that a strengthening of campaigns of preventing MDROs cross transmission. Appropriate antibiotic use might also help to limit de diffusion of MDRO in hospital and community.

The endless increase of antibiotic resistance in Enterobacteriaceae and the activity of new compounds to face the challenge

The endless increase of antibiotic resistance in Enterobacteriaceae and the activity of new compounds to face the challenge

The endless increase of antibiotic resistance in Enterobacteriaceae and the activity of new compounds to face the challenge

The endless increase of antibiotic resistance in Enterobacteriaceae and the activity of new compounds to face the challenge

Translocation of Carbapenemase Gene blaKPC-2 both Internal and External to Transposons Occurs via Novel Structures of Tn1721 and Exhibits Distinct Movement Patterns.

The blaKPC-2 gene encodes a carbapenemase that hydrolyzes almost all β-lactams, including carbapenems. The rapid emergence and international spread of this gene in Enterobacteriaceae seriously limit clinical treatment, posing an alarming threat for public health. Transposable elements, such as Tn4401, a proven transposon in Europe, the United States, and elsewhere, often play a role in the dissemination of the blaKPC-2 gene. In eastern China, the blaKPC-2 gene is frequently associated with several novel structures of Tn1721, but their transposition ability and mechanism of movement remain unclear. Here, we experimentally demonstrate that Tn1721-like transposons are capable of transferring blaKPC-2 both internal and external to the Tn1721 element from one strain to another and that distinct transposon structures exhibit different movement patterns and transposition frequencies. This process did not involve homologous recombination. Moreover, a 5-bp duplication of the target site, a characterized signature of transposition events in the Tn3 family, was confirmed. Tn1721-like transposons were found to insert preferentially into a 5-bp region that gradually exhibits a degenerated degree of AT-rich regions from both sides to the middle and that is immediately flanked by GC-rich regions. The observation in clinical isolates of diverse sequences flanking the transposons and a 5-bp duplication of the target site, as well as the prevalence of Tn1721-like transposons, also sustained our experimental results. This study first gives evidence about the functional role of Tn1721-like transposons in transferring the blaKPC-2 gene and provides new sight into the transposable element and the dissemination of antibiotic resistance in Enterobacteriaceae.

Prevalence and risk factors for intestinal carriage of CTX-M-type ESBLs in Enterobacteriaceae from a Thai community.

The incidence of infections caused by antimicrobial-resistant Enterobacteriaceae in Thailand is increasing and human intestinal flora is an important reservoir for these organisms. This study was carried out to determine the intestinal carriage of bla CTX-M extended spectrum ß-lactamase-positive Enterobacteriaceae (ESBL+E) and AmpC-positive Enterobacteriaceae in a community setting in Northern Thailand, and to identify potential risk factors for carriage. A total of 307 fecal samples were collected from healthy volunteers in Phitsanulok province, and cefotaxime-resistant Enterobacteriaceae (CtxRE) were isolated using selective media. Polymerase chain reaction (PCR) was used to detect ESBL and AmpC genes. Risk factors were analyzed using multiple logistic regression. Genotyping was performed by multilocus sequence typing (MLST) analysis. Two hundred ninety-one CtxRE isolates were obtained and Escherichia coli was the predominant organism (66.3%). The intestinal carriage rates of bla CTX-M ESBL+E and AmpC-positive Enterobacteriaceae were 52.1% and 6.2%, respectively. Comparative levels of bla CTX-M group 1 and bla CTX-M group 9 were found while bla CMY-2 was the predominant genotype among AmpC genes. Co-existence of two ß-lactamase genes in a single isolate was found in 6.5% of isolates. Consumption of undercooked meat was strongly associated with intestinal carriage of bla CTX-M ESBL+E (p=0.003, OR=2.133, 95% CI=1.289-3.530). Phylogenetic grouping and MLST analysis of E. coli isolates revealed the presence of E. coli B2-ST131 (n=8). Of these, seven carried bla CTX-M-group 9 and 1 carried bla CMY-2. Our results suggest that residents in Thailand are at high risk for developing endogenous infections caused by antibiotic-resistant Enterobacteriaceae.

Characterization of Antibiotic Resistance in Enterobacteriaceae From Agricultural Manure and Soil in Portugal

Characterization of Antibiotic Resistance in Enterobacteriaceae From Agricultural Manure and Soil in Portugal

Intestinal Carriage of Third-Generation Cephalosporin-Resistant and Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae in Healthy US Children.

The epidemiology of antibiotic-resistant Enterobacteriaceae intestinal carriage in healthy US children has not been well characterized. Children between 14 days and 14 years of age were enrolled during well-child visits in Oakland, California, Kansas City, Kansas, and Nashville, Tennessee, between December 2013 and March 2015. Data on recent antibiotic use by the child and travel and hospitalization history of all members of each child's household were obtained with a risk-factor survey. Stool specimens collected from the subjects were screened for extended-spectrum β-lactamase-producing (ESBL-P) bacteria using CHROMagar ESBL medium. Putative ESBL-P Escherichia coli and Klebsiella colonies underwent phenotypic confirmation by double-disk synergy testing; confirmed third-generation cephalosporin-resistant (3GCR) isolates underwent additional antibiotic-susceptibility testing. In 519 subjects, the overall 3GCR Enterobacteriaceae carriage rate was 4.4% (n = 23) and ranged from 3.4% to 5.1% among the study sites. The ESBL-P Enterobacteriaceae carriage rate was 3.5% (n = 18). The rates of 3GCR Enterobacteriaceae carriage was highest in 1 to <2 year olds at 6.5%, and was 5.2% in <5 year-olds vs 1.7% in ≥5-year-olds (P = .11). 3GCR and ESBL-P Enterobacteriaceae carriage was associated with international travel within the previous year; 11.1% of ESBL-P Enterobacteriaceae carriers reported this history compared with 1.6% of noncarriers (P = .004). No other queried factor was found to increase risk. Of the 24 analyzed 3GCR isolates, 58% were multidrug resistant. The 3GCR Enterobacteriaceae carriage rate exceeds 5% in healthy US children <5 years of age. International travel within the previous year increased the risk of 3GCR and ESBL-P Enterobacteriaceae carriage. In contrast, we found no differences in the rates of hospitalization or recent antibiotic exposure between carriers and noncarriers. Young children, who have the highest prevalence of colonization, might be a sentinel population to study to gain a better understanding of community sources of antibiotic-resistant Enterobacteriaceae.

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

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

Carriage of antibiotic-resistant Enterobacteriaceae in hospitalised children in tertiary hospitals in Harare, Zimbabwe

BackgroundExtended-spectrum β-lactamase-producing and gentamicin resistant Enterobacteriaceae are increasingly recognised as a major cause of infection in low-income countries. We assessed the prevalence of gastrointestinal carriage of these bacteria in hospitalised children in Harare, Zimbabwe.MethodsWe conducted a cohort study in paediatric inpatients at two tertiary-referral hospitals between May and July 2015. Rectal swabs and faecal samples were collected within 24 h of admission and further follow-up samples were collected on alternate days during hospitalization. Disc-based, selective and enrichment methods were used to detect carriage of these two forms of resistance. Standard methods were used to confirm resistance status and determine the susceptibility of resistant isolates to other commonly-used antibiotics.ResultsOne hundred and sixty four paediatric inpatient admissions (median age = 1.0 year, IQR = 0.2–2.2years) were enrolled, and an average of 1.9 faecal samples per patient were collected. On admission, 68/164 (41%) patients had both ESBL and gentamicin-resistant Enterobacteriaceae detected, 18 (11%) had ESBL only, 17 (10%) had gentamicin resistance only and 61 (37%) had negative screening for both forms of resistance. During hospitalisation, 32/164 (20%) patients were found to have a type of resistant organism which was not present in their admission sample. We found that faecal samples and use of a selective enrichment broth enhanced the detection of resistant organisms. Amongst resistant bacteria isolated, there were high levels of resistance to ciprofloxacin and chloramphenicol, but not ertapenem.ConclusionsMore than half of children had enteric carriage of a clinically-relevant form of antibiotic resistance on admission to public-sector hospitals in urban Zimbabwe. Additionally, a fifth of children acquired a further form of resistance during hospitalisation. Urgent action is needed to tackle the spread of antibiotic resistant enteric bacteria in African hospitals.

Gut yeast communities in Larus michahellis from various breeding colonies.

Yellow-legged gulls have been reported to carry antibiotic-resistant Enterobacteriaceae; however, the gut mycobiota of these birds has not yet been described. In this study, we analyzed the gut yeast communities in five yellow-legged gull breeding colonies along the Mediterranean littoral in southern France. Gull fecal samples were inoculated onto four types of culture media, including one supplemented with itraconazole. Yeast species richness, abundance, and diversity were estimated, and factorial analysis was used to highlight correspondences between breeding colonies. Yeast grew in 113 of 177 cultures, and 17 distinct yeast species were identified. The most frequent species were Candida krusei (53.5%), Galactomyces geotrichum (44.1%), C. glabrata (40.9%), C. albicans (20.5%), and Saccharomyces cerevisiae (18.1%). Gut yeast community structure in the gulls at both Pierre-Blanche Lagoon (PB) and Frioul Archipelago (F) were characterized by greater species richness and diversity than in those at the two cities of La Grande-Motte (GM) and Palavas-les-Flots (PF) as well as Riou Archipelago (R). Gulls in these latter three sites probably share a similar type of anthropogenic diet. Notably, the proportion of anthropic yeast species, including C. albicans and C. glabrata, in the gull mycobiota increased with gull colony synanthropy. Antifungal resistance was found in each of the five most frequent yeast species. We found that the gut yeast communities of these yellow-legged gulls include antifungal-resistant human pathogens. Further studies should assess the public health impact of these common synanthropic seabirds, which represent a reservoir and disseminator of drug-resistant human pathogenic yeast into the environment.

A novel Direct MIC-gradient Strip Method to screen for antibiotic-resistant faecal Enterobacteriaceae

A novel method to detect resistant faecal Enterobacteriaceae was developed by applying MIC-gradient strips directly onto agar plates inoculated with faeces. The method provided the susceptibility pattern (MICs) of the dominant bacterial population directly on the plates and also detected smaller resistant subpopulations with a sensitivity of 1/105.

The economic burden of urinary tract infections in women visiting general practices in France: a cross-sectional survey.

BackgroundUrinary tract infections (UTIs) are among the most common bacterial infections. Despite this burden, there are few studies of the costs of UTIs. The objective of this study was to determine the costs of UTIs in women over 18 years of age who visit general practitioners in France.MethodsThe direct and indirect costs of clinical UTIs were estimated from societal, French National Health Insurance and patient perspectives. The study population was derived from a national cross-sectional survey entitled the Drug-Resistant Urinary Tract Infection (Druti). The Druti included every woman over 18 years of age who presented with symptoms of UTI and was conducted in France in 2012 and 2013 to estimate the annual incidence of UTIs due to antibiotic-resistant Enterobacteriaceae in women visiting general practitioners (GPs) for suspected UTIs.ResultsOf the 538 women included in Druti, 460 were followed over 8 weeks and included in the cost analysis. The mean age of the women was 46 years old. The median cost of care for one episode of a suspected UTI was €38, and the mean cost was €70. The annual societal cost was €58 million, and €29 million of this was reimbursed by the French National Health Insurance system. In 25 % of the cases, the suspected UTIs were associated with negative urine cultures. The societal cost of these suspected UTIs with negative urine cultures was €13.5 million. No significant difference was found between the costs of the UTIs due to antibiotic-resistant E. coli and those due to wild E. coli (p = 0.63).ConclusionIn the current context in which the care costs are continually increasing, the results of this study suggests that it is possible to decrease the cost of UTIs by reducing the costs of suspected UTIs and unnecessary treatments, as well as limiting the use of non-recommended tests.Electronic supplementary materialThe online version of this article (doi:10.1186/s12913-016-1620-2) contains supplementary material, which is available to authorized users.

Tn6026 and Tn6029 are found in complex resistance regions mobilised by diverse plasmids and chromosomal islands in multiple antibiotic resistant Enterobacteriaceae

Transposons flanked by direct copies of IS26 are important contributors to the evolution of multiple antibiotic resistance. Tn6029 and Tn6026 are examples of composite transposons that have become widely disseminated on small and large plasmids with different incompatibility markers in pathogenic and commensal Escherichia coli and various serovars of Salmonella enterica. Some of the plasmids that harbour these transposons also carry combinations of virulence genes. Recently, Tn6029 and Tn6026 and derivatives thereof have been found on chromosomal islands in both established and recently emerged pathogens. While Tn6029 and Tn6026 carry genes encoding resistance to older generation antibiotics, they also provide a scaffold for the introduction of genes encoding resistance to a wide variety of clinically relevant antibiotics that are mobilised by IS26. As a consequence, Tn6029 and Tn6026 or variants are likely to increasingly feature in complex resistance regions in multiple antibiotic resistant Enterobacteriaceae that threaten the health of humans and food production animals.

Colonization with Enterobacteriaceae producing ESBLs in children attending pre-school childcare facilities in the Lao People's Democratic Republic.

ObjectivesIntestinal carriage constitutes an important reservoir of antimicrobial-resistant bacteria, with some of the highest rates reported from Asia. Antibiotic resistance has been little studied in Laos, where some antibiotics are available without restriction, but others such as carbapenems are not available.Patients and methodsWe collected stools from 397 healthy children in 12 randomly selected pre-school childcare facilities in and around Vientiane. Colonization with ESBL-producing Enterobacteriaceae (ESBLE) and carbapenemase-producing Enterobacteriaceae (CPE) was detected using a disc diffusion screening test and ESBLE were characterized using WGS. Risk factor data were collected by questionnaire.ResultsNinety-two children (23%) were colonized with ESBLE, mainly Escherichia coli carrying blaCTX-M and Klebsiella pneumoniae carrying blaSHV or blaCTX-M, which were frequently resistant to multiple antibiotic classes. Although residence in Vientiane Capital, foreign travel, higher maternal level of education, antibiotic use in the preceding 3 months and attending a childcare facility with a ‘good’ level of hygiene were all associated with ESBLE colonization on univariable analysis, a significant association remained only for antibiotic use when a stepwise approach was used with a multivariate random-effects model. WGS analysis suggested transmission in both childcare facilities and community settings.ConclusionsThe high prevalence of paediatric colonization with ESBLE in Laos, one of the highest reported in Asia, is probably the result of inappropriate antibiotic use. Paediatric colonization with CPE was not identified in this study, but it is important to continue to monitor the spread of antibiotic-resistant Enterobacteriaceae in Laos.

Antibiotic resistance in Enterobacteriaceae: what impact on the efficacy of antibiotic prophylaxis in colorectal surgery?

Antibiotic prophylaxis, introduced in the 1940s, brought in an era of relatively safe colorectal surgery. This was achieved in part due to the prevention of surgical site infections (SSIs) caused by Enterobacteriaceae. Since then, Enterobacteriaceae have become increasingly resistant to the antibiotics commonly used for prophylaxis. The impact of being colonized preoperatively with resistant Enterobacteriaceae on the efficacy of colorectal SSI prophylaxis, if any, is unknown. It is also difficult to predict the likely impact of resistance as the exposure‒response relationships have not been determined for antibiotic surgical prophylaxis. Neither is it known which test for resistance to use; the importance of the concentration of Enterobacteriaceae in the colon, the ability of different species of Enterobacteriaceae to cause SSIs, and the comparative ability of minimum inhibitory concentration or presence of a resistance mechanism in predicting SSI risk have yet to be established. Clinical research is urgently needed to answer these questions.

Transmission of Antibiotic Resistant Enterobacteriaceae between Animals and Humans Gastrointestinal Tract with the Evidence of in vivo Plasmid Transfer

Abstract: Recently, the main point of discussion is being undertaken whether the resistance of bacteria and plasmids could have been transmitted to humans from animals. Using antimicrobials in livestock production was previously shown to be followed by the occurrence of the resistant bacteria in the treated animals as well as in humans (caretakers, their family members etc.). Evidences exist that the transmission of resistance might have taken place from animals to humans. Many of these evidences were not direct and were based on the similarities between the resistance profiles of bacteria (among others indicatory E. coli ) isolated from animals (poultry, pigs, cattle) and from humans having contact with these animals (farm workers, animal caretakers, their family members). Direct evidences have been based on the molecular methods allowing the detection of either clonally related, resistant zoonotic bacteria in humans and animals or related to resistance of plasmids isolated from humans and animals. Key words : Enterobacteriaceae , β-lactamase, E. coli , CTX-M Antibiyotik Direncli Enterobacteriaceae’lerin Hayvan ve Insan Sindirim Sistemi Arasinda in vivo Plazmit Transferinden Kaynakli Gecisi Ozet: Esas tartisma konusu olan nokta, bakteri ve plazmit kaynakli bakteri direncinin hayvanlardan insanlara nasil gecebilecegidir. Antibiyotiklerin ciftlik hayvanlarinda kullanimi daha onceleri direncli bakterilerin tedavi gormus hayvanlarda ve insanlarda varligini gostermistir (hayvan bakicilari ve ciftlik calisanlari). Direncin gecisinin hayvanlardan insanlara dogru olabilecegi seklinde kanitlar bulunmaktadir. Bu kanitlarin cogu, direkt olmamakla birlikte hayvanlardan (ciftlik hayvanlari) ve bunlarla temas halindeki insanlardan (hayvan bakicilari ve ciftlik calisanlari) izole edilen bakteriler arasindaki direnc profillerinin benzerliklerine dayanmaktadir. Direkt kanitlar, birbirleriyle klonal iliskili insan ve hayvan kaynakli direncli zoonotik bakterilerin veya yine bunlardaki direncle ilgili plazmitlerin molekuler metotlara dayali olarak saptanmasi ile olmustur. Anahtar kelimeler: Enterobacteriaceae , β-laktamaz, E. coli , CTX-M

Epidemiology and prognostic determinants of bacteraemic catheter-acquired urinary tract infection in a single institution from 1991 to 2010

To determine the epidemiology of bacteraemic Catheter-Acquired Urinary Tract Infection (CA-UTI) and to identify independent predictors of mortality. This study was part of a bloodstream infection surveillance study that prospectively collected data on consecutive patients with bacteraemia in our institution from 1991 to 2010. Factors associated with 30-day mortality were determined. CA-UTI was the confirmed source of 1007 bacteraemias. The most common microorganisms isolated were Escherichiacoli (42%), Klebsiella spp (15%), Enterococcus faecalis (12%) and Pseudomonas aeruginosa (12%). Along the 2006-2010 periods, antibiotic-resistant E. coli and Klebsiella spp isolates accounted for 49% of the bacteraemia due to CA-UTI. Shock and mortality accounted for 125 and 92 cases, respectively (12% and 9%). Factors associated with mortality were: inappropriate empirical treatment (OR: 1.86, 95% CI: 1.48-2.44), ultimately or rapidly fatal prognosis of underlying disease (OR: 2.56, 95% CI: 1.48-4.44) and shock on presentation (OR: 12.62, 95% CI: 7.61-20.95). Inappropriate empirical treatment was most frequent in cases of bacteraemia produced by antibiotic-resistant E. coli or Klebsiella spp, Enterococcus spp. and P. aeruginosa. Factors associated with the isolation of a microorganism of this type were previous antibiotic therapy and healthcare-associated bacteraemia (OR: 1.50, 95% CI: 1.16-2.14 and OR: 3.03, 95% CI: 2.22-4.01, respectively). In cases of previous antibiotic therapy or healthcare-associated bacteraemic CA-UTI may indicate the need to initiate empirical therapy activity against antibiotic-resistant Enterobacteriaceae, E. faecalis and P. aeruginosa.

Evaluation of drug-resistant Enterobacteriaceae in retail poultry and beef

There has been increasing concern on the emergence of multidrug-resistant foodborne pathogens from foods of animal origin, including poultry. The current study aimed to evaluate antibiotic-resistant Enterobacteriaceae from raw retail chicken/turkey parts (thigh, wings, breast, and ground) and beef meat (ground and chunks) in Middle Tennessee. Resistance of the collected Enterobacteriaceae to a panel of antibiotics was determined by the Kirby-Bauer disk diffusion test. Retail meats were also assayed for the presence of Salmonella spp. and Escherichia coli O157:H7. Two hundred thirty-seven samples representing 95.2% of the total of 249 samples tested were positive for Enterobacteriaceae. The level of contamination with Enterobacteriaceae in raw meats ranged from 3.26 log10 cfu/g to 4.94 log10 cfu/g with significant differences in counts among meat types (P < 0.05). Contamination was significantly greater (P < 0.05) in ground beef, beef chucks, ground chicken, chicken breast, and turkey wings (4.92, 4.58, 4.94, 4.75, 4.13 log10 cfu/g, respectively) than ground turkey and chicken wings (3.26 and 3.26 log10 cfu/g, respectively). Klebsiella oxytoca, Serratia spp., E. coli, and Haffnia alvei were most prevalent contaminants at 27.4, 14.3, 12.1, and 11.4%, respectively. Resistance of the Enterobacteriaceae to antimicrobials was most frequent with erythromycin, penicillin, and ampicillin at 100, 89, and 65.8%, respectively. Few (2.7%) of the Enterobacteriaceae were resistant to chloramphenicol. Salmonella spp., E. coli O157:H7, Morganella morganii, Yersinia enterocolitica, and Vibrio parahemolyticus exhibited multiple drug resistance. This investigation demonstrates that raw poultry and beef are potential reservoirs of antibiotic-resistant Enterobacteriaceae.

Prevalence of antibiotic-resistant enterobacteriaceae isolated from chicken and pork meat purchased at the slaughterhouse and at retail in Bavaria, Germany

The purpose of this study was to investigate chicken and pork meat sampled at the slaughterhouse and at retail for differences in the presence of antibiotic resistant Gram-negative bacteria. For this aim, Escherichia coli (n=677), Enterobacter spp. (n=167), Citrobacter spp. (n=83), Serratia spp. (n=116), Klebsiella spp. (n=125), and Salmonella spp. (n=89) were isolated from 500 chicken and 500 pork samples purchased at the slaughterhouse and at retail (in the same amounts) in Germany. Salmonella were present in 17% of the chicken, and in 0.4% of the pork meat samples. There was a clear shift in the spectrum of coliforms from slaughterhouse to retail: Enterobacter, Citrobacter and Klebsiella were the most frequently detected coliforms (other than E. coli) from slaughterhouse samples, whereas the prevalence of Serratia spp. was up to eight times higher in retail samples. The prevalence of E. coli was higher in slaughterhouse samples, whereas the prevalence of other coliforms and Salmonella spp. was higher in retail samples. E. coli strains were often resistant to penicillins, streptomycin, spectinomycin, doxycycline and sulfamethoxazole/trimethoprim. Resistance rates of the other coliforms were generally low. Resistant and multi-resistant isolates were significantly more common in chicken meat. Compared to samples from the slaughterhouse, the prevalence of resistant bacteria tended to be higher in retail samples, probably due to good conditions for resistant bacteria on the matrix meat and/or due to secondary contamination with resistant strains. Therefore, stringent hygiene measures should be observed to reduce the risk of transmission of resistant bacteria from food to humans.

Comparison of ubiquitous antibiotic-resistant Enterobacteriaceae populations isolated from wastewaters, surface waters and drinking waters

This study aimed at assessing the role of ubiquitous (non-Escherichia coli) Enterobacteriaceae in the dissemination of antimicrobial resistance through the urban water cycle. Enterobacteriaceae isolated from a municipal wastewater treatment plant (111 isolates), urban water streams (33 isolates) and drinking water (123 isolates) were compared in terms of: (i) genera distribution, (ii) resistance to 12 antibiotics, and (iii) class 1 and class 2 integrons. The predominant bacterial genera were the same in the different types of water, although with a distinct pattern of species. The most prevalent resistance phenotypes were observed for amoxicillin, ticarcillin, cephalothin and sulphamethoxazole (24-59% in the three types of water). No resistance against ceftazidime or meropenem was observed. Resistance to cephalothin, amoxicillin and sulphamethoxazole was significantly more prevalent in drinking water, water streams and wastewater, respectively, than in the other types of water. It was possible to recognize antibiotic-resistance associations, namely for the pairs streptomycin-tetracycline (positive) and ticarcillin-cephalotin (negative). Class 1 and/or class 2 integrons with similar gene cassettes were detected in the three types of water. This study demonstrated that Enterobacteriaceae are important vehicles of antibiotic resistance, namely in drinking water.