High prevalence of extended-spectrum-β-lactamase-producing Enterobacteriaceae in organic and conventional retail chicken meat, Germany

Investigation of Extended-Spectrum and AmpC β-Lactamase-Producing Enterobacteriaceae from Retail Seafood in Berlin, Germany

Retail seafood in Berlin, Germany, was investigated to detect the prevalence and quantitative load of Enterobacteriaceae that produce extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase (AmpC). A total of 160 raw seafood samples were screened for the presence of these bacteria using MacConkey agar supplemented with 1 mg/L cefotaxime after nonselective enrichment. Isolated species were subsequently identified using matrix-assisted laser desorption-ionization time-of-flight analysis. ESBL and AmpC production was tested by the disk diffusion method, and ESBL and AmpC genes were characterized using real-time and conventional PCR assays with DNA sequencing. Spread plating was used for quantification of ESBL- and AmpC-producing Enterobacteriaceae. Overall, these bacteria were detected in 21.3% of seafood samples (34 of 160 samples) with prevalences of 22.5 and 20% for shrimp and bivalves, respectively. Of the positive samples, 91.2% contained an ESBL- or AmpC-producing Enterobacteriaceae load of <100 CFU/g (lower detection limit), and 8.8% contained 100 to 1,000 CFU/g. Among the 45 Enterobacteriaceae isolates, Klebsiella pneumoniae (13 isolates) and Escherichia coli (12 isolates) were the predominant species. ESBL and AmpC genes were detected in 33 isolates, with the majority of isolates harboring bla_CTX-M (27.3%), bla_CMY (21.2%), or bla_DHA (21.2%). Our study highlights the hazard associated with seafood containing ESBL- and AmpC-producing Enterobacteriaceae in Germany. Even though the contamination levels were low, the high prevalence of ESBL- and AmpC-producing Enterobacteriaceae in seafood might be of concern to public health because of the potential transmission of these bacteria from seafood to humans through the food chain.

Challenges in Infectious Diseases for Haematologists

Infections remain a threat for patients with haematological malignancies. In accordance with the European Hematology Association roadmap we provide a concise overview regarding the most relevant current challenges in infectious diseases for haematologists. These include bacterial infections and the need for antibiotic stewardship as well as infections with community-acquired respiratory viruses, infections in patients receiving targeted therapies, re-activations of latent infections and vaccination strategies. The following review intends to summarise the most relevant information for clinicians currently caring for patients with haematological malignancies. Recommendations given are based on the guidelines published by the Infectious Diseases Working Party of the German Society of Haematology and Medical Oncology.

Increased exposure to extended-spectrum β-lactamase-producing multidrug-resistant Enterobacteriaceae through the consumption of chicken and sushi products

The aim of this study was to determine the occurrence and patterns of resistance of extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae in food products purchased in Navarra, northern Spain. A total of 174 samples of fish and chicken were analyzed from September 2015 to September 2016, including raw and ready-to-eat products: trout (n = 25), salmon (n = 28), panga (n = 13), chicken nuggets and chicken scalopes (n = 32), sushi (n = 31) and sliced cooked poultry (n = 45). Cefpodoxime-resistant strains were isolated on ChromID ESBL agar and further phenotypic (antimicrobial study on MicroScan© NM37 panel) and genotypic characterization (multiplex PCR, sequencing and multi-locus sequence typing, MLST) was performed to confirm and characterize ESBL producers. Raw chicken and sushi have been determined as the most risky products regarding transmission of ESBL-producing Enterobacteriaceae (occurrence 53.1% and 19.4%, respectively), while sliced cooked poultry products appear to be a safe product in this aspect. With regard to raw fish, prevalence in salmon was lower (3.6%) than in trout and panga (16.0%). Ninety-eight per cent of ESBL isolates (n = 50) show multidrug-resistant profiles, highlighting the high resistances against quinolones and tetracyclines observed in chicken isolates, as well as against ertapenem and chloramphenicol in sushi strains. Predominant β-lactamase type was SHV-12 (50.1%), followed by TEM-type (24.5%) and CTX-M (20.8%). In addition, CTX-M type was only detected in chicken products. The phylogenetic study showed the prevalence of groups A (35%), F (25%) and B1 (15%), usually related to nonvirulent strains. MLST E. coli isolates (n = 20) were grouped into 5 clonal complexes (CC) and 15 sequence types (ST), showing high clonal diversity. ST117 was the prevalent sequence type, while the human pathogen ST131 was not detected in this study. The high prevalence of ESBL-producing multidrug-resistant Enterobacteriaceae detected in products of widespread consumption such as chicken and sushi, increases the concern regarding human exposure to superbugs and encourages the need to improve surveillance of this public health issue.

Prevalence and Characterization of Multi-Drug-Resistant Gram-Negative Bacilli Isolated From Lebanese Poultry: A Nationwide Study

Currently, antimicrobial resistance is one of the most prominent public health issues. In fact, there is increasing evidence that animals constitute a reservoir of antimicrobial resistance. In collaboration with the Lebanese Ministry of Agriculture, the aim of this study was to determine the prevalence of intestinal carriage of multi-drug-resistant Gram-negative Bacilli in poultry farms at the national level. Between August and December 2015, 981 fecal swabs were obtained from 49 poultry farms distributed across Lebanon. The swabs were subcultured on MacConkey agar supplemented with cefotaxime (2 μg/ml). Isolated strains were identified using MALDI-TOF mass spectrometry. Multilocus sequence typing analysis was performed for Escherichia coli. Phenotypic detection of extended spectrum β-lactamases (ESBL) and AmpC production was performed using double disk synergy and the ampC disk test, respectively. β-lactamase encoding genes bla_CTX-M, bla_TEM, bla_SHV, bla_FOX, bla_MOX, bla_EBC, bla_ACC, bla_DHA, and bla_CMY using PCR amplification. Out of 981 fecal swabs obtained, 203 (20.6%) showed bacterial growth on the selective medium. Of the 235 strains isolated, 217 were identified as E. coli (92%), eight as Klebsiella pneumoniae (3%), three as Proteus mirabilis (1%) and three as Enterobacter cloacae (1%). MLST analysis of E. coli isolates showed the presence of ST156, ST5470, ST354, ST155, and ST3224. The phenotypic tests revealed that 43.5, 28.5, and 20.5% of the strains were ampC, ESBL, and ampC/ESBL producers, respectively. The putative TEM gene was detected in 83% of the isolates, SHV in 20%, CTX-M in 53% and CMY ampC β-lactamase gene in 65%. Our study showed that chicken farms in Lebanon are reservoirs of ESBL and AmpC producing Gram-negative bacilli. The level of antibiotic consumption in the Lebanese veterinary medicine should be evaluated. Future studies should focus on the risk factors associated with the acquisition of multi-drug-resistant organisms in farm animals in Lebanon.

Detection of β-lactamase encoding genes in feces, soil and water from a Brazilian pig farm

β-lactam antibiotics are widely used for the treatment of different types of infections worldwide and the resistance to these antibiotics has grown sharply, which is of great concern. Resistance to β-lactams in gram-negative bacteria is mainly due to the production of β-lactamases, which are classified according to their functional activities. The aim of this study was to verify the presence of β-lactamases encoding genes in feces, soil, and water from a Brazilian pig farm. Different β-lactamases encoding genes were found, including bla_CTX-M-Gp1, bla_CTX-M-Gp9, bla_SHV, bla_OXA-1-like, bla_GES, and bla_VEB. The bla_SHV and bla_CTX-M-Gp1 genes have been detected in all types of samples, indicating the spread of β-lactam resistant bacteria among farm pigs and the environment around them. These results indicate that β-lactamase encoding genes belonging to the cloxacillinase, ESBL, and carbapenemase and they have high potential to spread in different sources, due to the fact that genes are closely related to mobile genetic elements, especially plasmids.

ESBL-producing Escherichia coli and Its Rapid Rise among Healthy People

Since around the 2000s, Escherichia coli (E. coli) resistant to both oxyimino-cephalosporins and fluoroquinolones has remarkably increased worldwide in clinical settings. The kind of E. coli is also identified in patients suffering from community-onset infectious diseases such as urinary tract infections. Moreover, recoveries of multi-drug resistant E. coli from the feces of healthy people have been increasingly documented in recent years, although the actual state remains uncertain. These E. coli isolates usually produce extended-spectrum β-lactamase (ESBL), as well as acquisition of amino acid substitutions in the quinolone-resistance determining regions (QRDRs) of GyrA and/or ParC, together with plasmid-mediated quinolone resistance determinants such as Qnr, AAC(6')-Ib-cr, and QepA. The actual state of ESBL-producing E. coli in hospitalized patients has been carefully investigated in many countries, while that in healthy people still remains uncertain, although high fecal carriage rates of ESBL producers in healthy people have been reported especially in Asian and South American countries. The issues regarding the ESBL producers have become very complicated and chaotic due to rapid increase of both ESBL variants and plasmids mediating ESBL genes, together with the emergence of various "epidemic strains" or "international clones" of E. coli and Klebsiella pneumoniae harboring transferable-plasmids carrying multiple antimicrobial resistance genes. Thus, the current state of ESBL producers outside hospital settings was overviewed together with the relation among those recovered from livestock, foods, pets, environments and wildlife from the viewpoint of molecular epidemiology. This mini review may contribute to better understanding about ESBL producers among people who are not familiar with the antimicrobial resistance (AMR) threatening rising globally.

CTX-M-15-Producing E. coli Isolates from Food Products in Germany Are Mainly Associated with an IncF-Type Plasmid and Belong to Two Predominant Clonal E. coli Lineages

Extended-spectrum beta-lactamases (ESBL) mediating resistance to 3rd generation cephalosporins are a major public health issue. As food may be a vehicle in the spread of ESLB-producing bacteria, a study on the occurrence of cephalosporin-resistantu Escherichia coli in food was initiated. A total of 404 ESBL-producing isolates were obtained from animal-derived food samples (e.g., poultry products, pork, beef and raw milk) between 2011 and 2013. As CTX-M-15 is the most abundant enzyme in ESBL-producing E. coli causing human infections, this study focusses on E. coli isolates from food samples harboring the bla_CTX-M-15 gene. The bla_CTX-M-15 gene was detected in 5.2% (n = 21) of all isolates. Molecular analyses revealed a phylogenetic group A ST167 clone that was repeatedly isolated from raw milk and beef samples over a period of 6 months. The analyses indicate that spread of CTX-M-15-producing E. coli in German food samples were associated with a multireplicon IncF (FIA FIB FII) plasmid and additional antimicrobial resistance genes such as aac(6)-Ib-cr, bla_OXA-1, catB3, different tet-variants as well as a class 1 integron with an aadA5/dfrA17 gene cassette. In addition, four phylogenetic group A ST410 isolates were detected. Three of them carried a chromosomal copy of the bla_CTX-M-15 gene and a single isolate with the gene on a 90 kb IncF plasmid. The bla_CTX-M-15 gene was always associated with the ISEcp1 element. In conclusion, CTX-M-15-producing E. coli were detected in German food samples. Among isolates of different matrices, two prominent clonal lineages, namely A-ST167 and A-ST410, were identified. These lineages may be important for the foodborne dissemination of CTX-M-15-producing E. coli in Germany. Interestingly, these clonal lineages were reported to be widely distributed and especially prevalent in isolates from humans and livestock. Transmission of CTX-M-15-harboring isolates from food-producing animals to food appears probable, as isolates obtained from livestock and food samples within the same time period exhibit comparable characteristics as compared to isolates detected from human. However, the routes and direction of transmission need further investigation.

Analysis of blaSHV-12-carrying Escherichia coli clones and plasmids from human, animal and food sources

Objectives

This study aimed at characterizing 23 Escherichia coli isolates from various sources and their respective bla SHV-12 -carrying plasmids and sequencing one of these plasmids completely.

Methods

Isolates were typed by XbaI-PFGE, MLST and PCR-based phylotyping. Transformed bla SHV-12 -carrying plasmids were examined by replicon typing, S1-nuclease, conjugation, EcoRI-HindIII-BamHI digests and plasmid MLST. Co-located resistance genes and integrons as well as the bla SHV-12 genetic environment were analysed by PCR and sequencing. One IncI1 plasmid was sequenced completely using HiSeq 2500 and gap closure by PCRs and Sanger sequencing.

Results

Among the 23 SHV-12-positive E. coli , some isolates from different sources showed the same characteristics: ST23/phylogroup A (human, dog, livestock), ST57/D (wild bird, chicken meat) and ST117/D (chicken meat, chicken). All bla SHV-12 genes were horizontally transferable via 30-120 kb plasmids of incompatibility groups IncI1 ( n  = 17), IncK ( n  = 3), IncF ( n  = 1), IncX3 ( n  = 1) and a non-typeable plasmid. IncK plasmids, indistinguishable in size and restriction patterns, were found in isolates from different sources (ST57/D, meat; ST131/B2, meat; ST57/B1, dog). The IncI1- bla SHV-12 -carrying plasmids were mostly assigned to plasmid ST (pST) 26 and pST3. Three plasmids showed novel pSTs (pST214, pST215). The majority of the IncI1 transformants exhibited resistance to β-lactams, chloramphenicol and streptomycin (in relation with a class 1 integron containing an estX - psp - aadA2 - cmlA1 - aadA1 - qacI gene cassette array), and to tetracycline. A novel bla SHV-12 environment was detected and whole plasmid sequencing revealed a Tn 21 -derived- bla SHV12 -ΔTn 1721 resistance complex.

Conclusions

Results from this study suggest that the dissemination of bla SHV-12 genes occurs by vertical (clonal) and horizontal transfer, the latter mainly mediated through IncI1 multidrug-resistance plasmids.

Prevalence of CTX-M-Producing Klebsiella spp. in Broiler, Kuroiler, and Indigenous Poultry in West Bengal State, India

This study was undertaken to detect the prevalence of CTX-M-producing Klebsiella spp. in healthy broiler, indigenous, and kuroiler birds reared in West Bengal (India) during November 2014-February 2015. In addition to CTX-M gene, the study was also conducted to reveal the occurrence of other β-lactamase and class I integron genes in Klebsiella spp. isolates along with their clonal relationship. A total of 321 cloacal swabs from healthy broiler, indigenous, and kuroiler birds were collected from different places of West Bengal, India. Klebsiella spp. isolation rate varies among different types of poultry birds (43.8-72.3%). In total, 33 (10.7%) Klebsiella spp. isolates were detected phenotypically as CTX-M producers and all the isolates possessed bla_CTX-M in polymerase chain reaction. Whereas 17 (51.5%) and 16 (48.5%) Klebsiella spp. isolates possessed bla_SHV, and bla_TEM with bla_CTX-M, respectively. None of the CTX-M-producing Klebsiella spp. isolates in this study possessed class I integron gene. Randomly amplified polymorphic DNA-based phylogenetic tree revealed the presence of clonal relationship among the CTX-M-producing Klebsiella spp. isolates, recovered from broilers and indigenous birds. This study identified broilers and indigenous game birds as a potential reservoir of CTX-M-producing Klebsiella spp., which could be transmitted to the human food chain directly or indirectly.

Types and prevalence of extended-spectrum beta-lactamase producing Enterobacteriaceae in poultry

For several billion years, bacteria have developed mechanisms to resist antibacterial substances. In modern time, antibiotics are frequently used in veterinary and human medicine for prevention and treatment of diseases, globally still also for their growth promoting effects as feed additives. This complex situation has evolved in accelerating development and prevalence of multi-drug resistant bacteria in livestock and people. Extended-spectrum beta-lactamase (ESBL) producing bacteria are resistant to a wide range of ß-lactam antibiotics. They are currently considered as one of the main threats for the treatment of infections in humans and animals. In livestock and animal products, poultry and poultry products show the highest prevalence of ESBL-producers with CTX-M-1, TEM-52 and SHV-12 being the most common ESBL-types in poultry. Escherichia coli and Salmonella spp. are the bacteria in poultry, which carry ESBL-genes most frequently. ESBL-producing bacteria are present at every level of the poultry production pyramid and can be detected even in the meconium of newly hatched chicks. The environment close to poultry barns shows high prevalence rates of these bacteria and contributes to an ongoing infection pressure with further ESBL-types. Probiotics have been shown to successfully reduce ESBL-producers in chicken, as well as ESBL-gene transfer. Other feed additives, such as zinc and copper, increase the prevalence of ESBL-producing bacteria when fed to animals. To our best knowledge, this is the first publication presenting a comparative overview of the prevalence of ESBL-types using data from different countries. To reduce the hazard for public health from poultry carrying high numbers of ESBL-producers, preventive measurements must include the surrounding environment and avoidance of antibiotic usage at all levels of the production pyramid. The first results, of the research on the impact of feed additives on the spread of ESBL-genes, indicate the diet as a further, possible magnitude of influence.

ESBL carriage in pig slaughterhouse workers is associated with occupational exposure

We investigated the prevalence of extended-spectrum β-lactamase (ESBL) carriage in slaughterhouse workers and the association with occupational exposure to slaughter animals and products. Stool samples from 334 employees in a Dutch pig slaughterhouse were obtained. Presence of ESBL was determined by selective plating, microarray analysis, and gene sequencing. Questionnaires were used to collect personal and occupational information. The overall prevalence of ESBL carriage was 4·8% (16/334). All ESBL-producing isolates were Escherichia coli. The ESBL genes detected were bla CTX-M-1 (n = 8), bla CTX-M-15 (n = 3), bla CTX-M-27 (n = 2), bla CTX-M-24 (n = 1), bla CTX-M-55 (n = 1), and bla SHV-12 (n = 1). A higher prevalence of ESBL was seen in workers in jobs with as tasks 'removal of lungs, heart, liver, tongue' (33%), and 'removal of head and spinal cord' (25%). For further analysis, participants were divided in two groups based on potential exposure to ESBL as related to their job title. One group with an assumed higher exposure to ESBL (e.g. stable work, stabbing, dehairing, removal of organs) and another group with an assumed lower exposure to ESBL (e.g. refrigeration, packaging and expedition). In the 'higher exposure' group, ten out of 95 (10·5%) were carrying ESBL vs. six out of 233 (2·6%) in the 'lower exposure' group. Human ESBL carriage was significantly associated with job exposure in the slaughterhouse (OR 4·5, CI 1·6-12·6). Results suggest that ESBL carriage in slaughterhouse workers overall is comparable with the Dutch population. Within the slaughterhouse population a difference in carriage exists depending on their position along the slaughter line and tasks involved.

Antibiotic resistance: What is so special about multidrug-resistant Gram-negative bacteria?

In the past years infections caused by multidrug-resistant Gram-negative bacteria have dramatically increased in all parts of the world. This consensus paper is based on presentations, subsequent discussions and an appraisal of current literature by a panel of international experts invited by the Rudolf Schülke Stiftung, Hamburg. It deals with the epidemiology and the inherent properties of Gram-negative bacteria, elucidating the patterns of the spread of antibiotic resistance, highlighting reservoirs as well as transmission pathways and risk factors for infection, mortality, treatment and prevention options as well as the consequences of their prevalence in livestock. Following a global, One Health approach and based on the evaluation of the existing knowledge about these pathogens, this paper gives recommendations for prevention and infection control measures as well as proposals for various target groups to tackle the threats posed by Gram-negative bacteria and prevent the spread and emergence of new antibiotic resistances.

Risk factors for ESBL-producing Escherichia coli on pig farms: A longitudinal study in the context of reduced use of antimicrobials

The presence of extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E. coli) in food animals is a public health concern. This study aimed to determine prevalence of ESBL-E. coli on pig farms and to assess the effect of reducing veterinary antimicrobial use (AMU) and farm management practices on ESBL-E. coli occurrence on pig farms. During 2011–2013, 36 Dutch conventional pig farms participated in a longitudinal study (4 sampling times in 18 months). Rectal swabs were taken from 60 pigs per farm and pooled per 6 pigs within the same age category. Presence of ESBL-E. coli was determined by selective plating and ESBL genes were characterized by microarray, PCR and gene sequencing. An extensive questionnaire on farm characteristics and AMU as Defined Daily Dosages per Animal Year (DDDA/Y) was available for the 6-month periods before each sampling moment. Associations between the presence of ESBL-E. coli-positive pigs and farm management practices were modelled with logistic regression. The number of farms with ESBL-E. coli carrying pigs decreased from 16 to 10 and the prevalence of ESBL-E. coli-positive pooled pig samples halved from 27% to 13%. Overall, the most detected ESBL genes were bla_CTX-M-1, bla_TEM-52 and bla_CTX-M-14. The presence of ESBL-E. coli carrying pigs was not related to total AMU, but it was strongly determined by the presence or absence of cephalosporin use at the farm (OR = 46.4, p = 0.006). Other farm management factors, related with improved biosecurity, were also plausibly related to lower probabilities for ESBL-E. coli-positive farms (e.g. presence of a hygiene lock, pest control delivered by a professional). In conclusion, ESBL-E. coli prevalence decreased in pigs during 2011 and 2013 in the Netherlands. On pig farms, the use of cephalosporins was associated with the presence of ESBL-E. coli carrying pigs.

Extended-spectrum β-lactamase/AmpC- and carbapenemase-producing Enterobacteriaceae in animals: a threat for humans?

There has been a great and long-term concern that extended-spectrum β-lactamase (ESBL)/AmpC- and carbapenemase-producing Enterobacteriaceae occurring in animals may constitute a public-health issue. A large number of factors with complex interrelations contribute to the spread of those bacteria among animals and humans. ESBL/AmpC- or carbapenemase-encoding genes are most often located on mobile genetic elements favouring their dissemination. Some shared reservoirs of ESBL/AmpC or carbapenemase genes, plasmids or clones have been identified and suggest cross-transmissions. Even though exposure to animals is regarded as a risk factor, evidence for a direct transfer of ESBL/AmpC-producing bacteria from animals to humans through close contacts is limited. Nonetheless, the size of the commensal ESBL/AmpC reservoir in non-human sources is dramatically rising. This may constitute an indirect risk to public health by increasing the gene pool from which pathogenic bacteria can pick up ESBL/AmpC/carbapenemase genes. The extent to which food contributes to potential transmission of ESBL/AmpC producers to humans is also not well established. Overall, events leading to the occurrence of ESBL/AmpC- and carbapenemase-encoding genes in animals seem very much multifactorial. The impact of animal reservoirs on human health still remains debatable and unclear; nonetheless, there are some examples of direct links that have been identified.

[Multidrug-resistant bacteria in Germany. The impact of sources outside healthcare facilities]

BACKGROUND

Currently, there is an ongoing discussion about the question whether the emergence of multidrug-resistant microorganisms (MDRO) among humans is due to transfer of these bacteria from animals.

OBJECTIVES

This review summarizes data on the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase (ESBL) producing enterobacteria in animals and humans, and describes knowledge about transmission pathways.

MATERIAL AND METHODS

After a scientific literature analysis, relevant articles were identified by screening of titles and abstracts, amended by publications of infection control authorities and the respective reference lists.

RESULTS

MDRO are both transmitted in the nosocomial setting and are increasingly detected as sources of infection outside healthcare facilities.

CONCLUSIONS

Due to new transmission pathways of MDRO an inter-disciplinary approach towards prevention is necessary, involving medical, pharmaceutical and veterinary expertise.

EMA and EFSA Joint Scientific Opinion on measures to reduce the need to use antimicrobial agents in animal husbandry in the European Union, and the resulting impacts on food safety (RONAFA)

EFSA and EMA have jointly reviewed measures taken in the EU to reduce the need for and use of antimicrobials in food-producing animals, and the resultant impacts on antimicrobial resistance (AMR). Reduction strategies have been implemented successfully in some Member States. Such strategies include national reduction targets, benchmarking of antimicrobial use, controls on prescribing and restrictions on use of specific critically important antimicrobials, together with improvements to animal husbandry and disease prevention and control measures. Due to the multiplicity of factors contributing to AMR, the impact of any single measure is difficult to quantify, although there is evidence of an association between reduction in antimicrobial use and reduced AMR. To minimise antimicrobial use, a multifaceted integrated approach should be implemented, adapted to local circumstances. Recommended options (non-prioritised) include: development of national strategies; harmonised systems for monitoring antimicrobial use and AMR development; establishing national targets for antimicrobial use reduction; use of on-farm health plans; increasing the responsibility of veterinarians for antimicrobial prescribing; training, education and raising public awareness; increasing the availability of rapid and reliable diagnostics; improving husbandry and management procedures for disease prevention and control; rethinking livestock production systems to reduce inherent disease risk. A limited number of studies provide robust evidence of alternatives to antimicrobials that positively influence health parameters. Possible alternatives include probiotics and prebiotics, competitive exclusion, bacteriophages, immunomodulators, organic acids and teat sealants. Development of a legislative framework that permits the use of specific products as alternatives should be considered. Further research to evaluate the potential of alternative farming systems on reducing AMR is also recommended. Animals suffering from bacterial infections should only be treated with antimicrobials based on veterinary diagnosis and prescription. Options should be reviewed to phase out most preventive use of antimicrobials and to reduce and refine metaphylaxis by applying recognised alternative measures.

International travel is a risk factor for extended-spectrum β-lactamase-producing Enterobacteriaceae acquisition in children: A case-case-control study in an urban U.S. hospital

BACKGROUND

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL) infections are increasing in both adults and children. The aim of this study was to describe the epidemiology of children with ESBL in an ethnically-diverse population, to determine what proportion of these infections were community-onset, and to identify risk factors predisposing children to ESBL acquisition.

METHODS

A case-case-control study of children aged 0-18 years was conducted from 2012 to 2014. Patients with ESBL (detected via VITEK2) were matched 1:1:5 (based on age, sex, specimen source, and healthcare setting) with non-ESBL and uninfected controls. Data on prior antibiotic and healthcare exposure, international travel, prior urinary tract infection (UTI), comorbid gastrointestinal (GI), genitourinary (GU), neurologic, and immunocompromising conditions were collected and compared.

RESULTS

Seventy-six patients were identified with 85 ESBL infections, of which 77 (91%) were E. coli. ESBL was isolated most frequently from urine (n = 72, 85%). Most infections were community-onset (n = 76, 89%) and were managed in the ambulatory setting (n = 47, 62%). On multivariate analysis, international travel (p < 0.001, OR 8.93; CI 2.92-27.78), comorbid GI condition (p = 0.002, OR 2.65, CI 1.36-5.15), Asian race (p = 0.005, OR 2.56, CI 1.34-4.89) and prior UTI (p < 0.001, OR 8.06, CI 3.47-18.87) were significant risk factors for ESBL.

CONCLUSION

Most ESBL infections in this study were community-onset. To our knowledge, this is the first description of international travel as a risk factor for ESBL acquisition in children in the United States.

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

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

Characterization of Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolates from Pigs and Farm Workers

Food-producing animals can serve as reservoirs for extended-spectrum β-lactamase (ESBL)-producing Escherichia coli . The present study aimed to characterize and compare ESBL-carrying E. coli isolates from both pigs and farm workers. Rectal swabs were obtained from 60 pigs on four pig-fattening farms (15 samples per farm), and rectal swabs were taken from 40 farm workers on these farms (10 samples per farm). ESBL-carrying E. coli isolates from the workers and pigs were characterized by ESBL genotype, antibiotic susceptibility, enterobacterial repetitive intergenic consensus type, and multilocus sequence type. ESBL-producing E. coli was detected in 34 (56.7%) of 60 pigs, and 20.0% (8 of 40) of the farm workers were positive for ESBL-producing E. coli . More importantly, ESBL-producing E. coli isolates with the same β-lactamase genes, antibiotic resistance profiles, enterobacterial repetitive intergenic consensus types, and multilocus sequence types were detected in both pigs and workers on the same pig farm. These findings were suggestive for transfer of ESBL-producing E. coli between animals and humans.

In vitro investigations into the use of antimicrobials in combination to maintain efficacy of fluoroquinolones in poultry

The aim of this study was to determine if apramycin, colistin or lincomycin-spectinomycin, in combination with enrofloxacin, was able prevent the emergence of mutants with reduced susceptibility to fluoroquinolone antibiotics in vitro. MICs were determined for enrofloxacin alone and in combination for panels of Campylobacter (n=37), Escherichia coli (n=52) and Salmonella (n=52) isolates. MIC results suggested that apramycin, colistin and lincomycin-spectinomycin worked in an additive/indifferent way when each was combined with enrofloxacin. Apramycin was considered the most promising antibiotic for combination-therapy in conjunction with enrofloxacin, and further evaluations (MBCs, MPCs and time-kill-curves) were performed for this combination for selected isolates. Results suggest combination-therapy of enrofloxacin with apramycin increases the efficacy, as well as decreasing the emergence and survival of bacteria with mutational resistance to fluoroquinolone antibiotics. Such combination-therapy, minimising the development of mutational resistance, may have relevance for Campylobacter, E. coli and Salmonella infections in poultry.

Exposure to pathogens among workers in a poultry slaughter and processing plant

BACKGROUND

Working conditions in poultry slaughter/processing plants may expose workers to zoonotic pathogens. We explored exposure to pathogens among poultry slaughter/processing plant workers including job duties as risk factors.

METHODS

We collected questionnaire data on job duties and nasal swabs from 110 workers at one plant in South Carolina. Swabs were tested for Staphylococcus aureus and gram-negative organisms. Isolates were screened for antimicrobial susceptibility.

RESULTS

There was no differences in prevalence of S. aureus carriage based on job duties. As compared with office or packing workers, the adjusted odds of GNO carriage was 6.29 times (95% CI: 1.43, 27.71) higher in slaughter or carcass processing workers and 5.94 times (95% CI: 0.94, 37.50) higher in cleaning or maintenance workers.

CONCLUSIONS

Poultry processing plant workers may have increased exposure to GNOs, depending on job duties. Am. J. Ind. Med. 59:453-464, 2016. © 2016 Wiley Periodicals, Inc.

Surveillance of bloodstream infections in pediatric cancer centers - what have we learned and how do we move on?

Pediatric patients receiving conventional chemotherapy for malignant disease face an increased risk of bloodstream infection (BSI). Since BSI may represent an acute life-threatening event in patients with profound immunosuppression, and show further negative impact on quality of life and anticancer treatment, the prevention of BSI is of paramount importance to improve and guarantee patients' safety during intensive treatment. The great majority of all pediatric cancer patients (about 85%) have a long-term central venous access catheter in use (type Broviac or Port; CVAD). Referring to the current surveillance definitions a significant proportion of all BSI in pediatric patients with febrile neutropenia is categorized as CVAD-associated BSI. This state of the art review summarizes the epidemiology and the distinct pathogen profile of BSI in pediatric cancer patients from the perspective of infection surveillance. Problems in executing the current surveillance definition in this patient population are discussed and a new concept for the surveillance of BSI in pediatric cancer patients is outlined.

High carriage rate of ESBL-producing Enterobacteriaceae at presentation and follow-up among travellers with gastrointestinal complaints returning from India and Southeast Asia

BACKGROUND

International travel contributes to the spread of multidrug-resistant microorganisms including extended spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE). We assessed the proportion of faecal carriers of ESBL-PE among 211 patients with gastrointestinal symptoms who returned to Berlin, Germany, after international travel.

METHODS

ESBL-PE were screened for on chromogenic agar, antimicrobial susceptibility testing was performed, and ESBL-genes were genotyped. Travel-related data were assessed by questionnaire.

RESULTS

Diarrhoea, abdominal pain and nausea were the main symptoms. Half of the travellers carried ESBL-PE (97% Escherichia coli); the proportion was highest for returnees from India (72%) and mainland Southeast Asia (59%), and comparatively lower for Africa (33%) and Central America (20%). Co-resistance to fluoroquinolones (particularly in isolates from India), gentamicin and cotrimoxazole was frequent but all isolates were carbapenem-susceptible. ESBL-PE carriage decreased with increasing timespan from return to presentation, and with age. At revisit of initially ESBL-PE positive patients half a year later, 28% (17/61) of the individuals were still carriers, CTX-M groups being congruent with the initial isolates. CTX-M groups 9 and 1/9, vegetarian diet and cat ownership tended to be associated with ESBL-PE carriage upon revisit.

CONCLUSIONS

Travellers, particularly those returning from India and Southeast Asia, constitute a relevant source of potential spread of ESBL-PE. Carriage declines over time but ESBL-PE persist for at least 6 months in a substantial proportion of individuals. Both genetic characteristics of the bacteria and lifestyle factors seem to contribute to persistent carriage of ESBL-PE. A recent, extra-European travel history argues for ESBL-PE screening and contact precautions for patients admitted to hospital.

Prevalence of Extended-Spectrum-β-Lactamase-Producing Escherichia coli in Imported Frozen Freshwater Fish in Eastern Province of Saudi Arabia

Background:

The prevalence of extended-spectrum β-lactamase (ESBL) production and antimicrobial susceptibility testing in the Escherichia coli in frozen freshwater fish imported into Saudi Arabia have not been investigated.

Objective:

The aim of this study was to investigate the prevalence of ESBL-producing E. coli in frozen freshwater fish imported into Saudi Arabia and retailed in various supermarkets and food stores in the Eastern Province of Saudi Arabia.

Materials and Methods:

A total of 405 imported freshwater fish samples: Catfish (n = 65); mrigal (n = 45); tilapia (n = 135); carfoo (n = 50); rohu (n = 75); and milkfish (n = 35) were purchased from supermarkets and screened for ESBL-producing E. coli using ESBL chromogenic selective agar. The phenotypically confirmed ESBL isolates were further tested for antimicrobial susceptibility testing against 21 antimicrobial agents and amplification of bla_TEM, bla_SHV, and bla_CTX-M genes using polymerase chain reaction.

Results:

A total of 110 out of the 405 (27.2%) freshwater fish samples were found to be positive for ESBL producing E. coli and yielded 224 confirmed isolates. The highest rates of multi-drug resistant patterns to antimicrobial agents were observed in E. coli isolated from catfish, mrigal, and tilapia imported from Thailand and milkfish imported from Vietnam. The most prevalent ESBL gene found in the samples was bla_CTX-M, which was detected in tilapia (100%, n = 30) imported from Thailand and carfoo (100%, n = 5), milkfish (60%, n = 24), catfish (52.3%, n = 34), and tilapia imported from India (34.8%, n = 24).

Conclusion:

The results confirmed the imported frozen freshwater fish is pool reservoir of antibiotic resistance and ESBL producing E. coli.

Widespread distribution of CTX-M and plasmid-mediated AmpC β-lactamases in Escherichia coli from Brazilian chicken meat

The dissemination of plasmid-mediated antimicrobial resistance genes may pose a substantial public health risk. In the present work, the occurrences of blaCTX-M and plasmid-mediated ampC and qnr genes were investigated in Escherichia coli from 16 chicken carcasses produced by four commercial brands in Brazil. Of the brands tested, three were exporters, including one of organic chicken. Our study assessed 136 E. coli isolates that were grouped into 77 distinct biotypes defined by their origin, resistance profiling, the presence of β-lactamase and plasmid-mediated quinolone resistance genes and enterobacterial repetitive intergenic consensus-polimerase chain reaction typing. The blaCTX-M-15, blaCTX-M-2 and blaCTX-M-8 genes were detected in one, 17 and eight different biotypes, respectively (45 isolates). Twenty-one biotypes (46 isolates) harboured blaCMY-2. Additionally, blaCMY-2 was identified in isolates that also carried either blaCTX-M-2 or blaCTX-M-8. The qnrB and/or qnrS genes occurred in isolates carrying each of the four types of β-lactamase determinants detected and also in oxyimino-cephalosporin-susceptible strains. Plasmid-mediated extended-spectrum β-lactamase (ESBL) and AmpC determinants were identified in carcasses from the four brands tested. Notably, this is the first description of blaCTX-M-15 genes in meat or food-producing animals from South America. The blaCTX-M-8, blaCTX-M-15 and blaCMY-2 genes were transferable in conjugation experiments. The findings of the present study indicate that plasmid-mediated ESBL and AmpC-encoding genes are widely distributed in Brazilian chicken meat.

Incidence, Antimicrobial Resistance, and Molecular Characteristics of Nontyphoidal Salmonella Including Extended-Spectrum β-Lactamase Producers in Retail Chicken Meat

The present study was undertaken to determine the prevalence of Salmonella in 100 chicken carcass samples from five integrated broiler operation brands in Korea. Serotypes, antibiotic resistance patterns, extended-spectrum β-lactamase (ESBL) genotype, and clonal divergence using multilocus sequence typing of the isolated strains were analyzed. A total of 42 chicken samples were contaminated with nontyphoidal Salmonella (NTS) isolates: 16 isolates (38%) were Salmonella Virchow, 9 (21%) were Salmonella Bareilly, and 8 (19%) were Salmonella Infantis. A multidrug resistance (MDR; resistant to more than three classes of antibiotics) phenotype was observed in 29% of the isolates, which were resistant to five or more classes of antibiotics. The dominant MDR type was resistance to classes of penicillin, cephalosporins, aminoglycosides, quinolones, and tetracyclines. All the MDR isolates were positive for ESBL producers, and all but one (with the CTX-M-1 genotype) had the CTX-M-15 genotype. Multilocus sequence typing of the isolates revealed ST16 as the dominant sequence type; Salmonella Virchow, Salmonella Infantis, and Salmonella Richmond were all ST16, indicating a close genetic relationship between these serovars. This is the first study in Korea showing the CTX-M-1 type of NTS and the prevalence of ESBL-producing strains among NTS isolated from retail chicken meat. Our findings suggest that MDR Salmonella contamination is widely prevalent in retail chicken meat, and consumption of inadequately cooked products could lead to dissemination of NTS, which is hazardous to human health.

Considerations About Antimicrobial Stewardship in Settings with Epidemic Extended-Spectrum β-Lactamase-Producing or Carbapenem-Resistant Enterobacteriaceae

Infections caused by gram-negative bacteria (GNB) resistant to multiple classes of antibiotics are increasing in many hospitals. Extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant Enterobacteriaceae in particular are now endemic in many parts of the world and represent a serious public health threat. In this era, antimicrobial stewardship programs are essential as targeted and responsible use of antibiotics improves patient outcomes and hopefully limits the selective pressure that drives the further emergence of resistance. However, some stewardship strategies aimed at promoting carbapenem-sparing regimens remain controversial and are difficult to implement when resistance rates to non-carbapenem antibiotics are increasing. Coordinated efforts between stewardship programs and infection control are essential for reversing conditions that favor the emergence and dissemination of multidrug-resistant GNB within the hospital and identifying extra-institutional "feeder reservoirs" of resistant strains such as long-term care facilities, where colonization is common despite limited numbers of serious infections. In settings where ESBL resistance is endemic, the cost-effectiveness of expanded infection control efforts and antimicrobial stewardship is still unknown. Once a patient has been colonized, selective oral or digestive decontamination may be considered, but evidence supporting its effectiveness is limited in patients who are already colonized or in centers with high rates of resistance. Moreover, temporary success at decolonization may be associated with a higher risk of relapse with strains that are resistant to the decolonizing antibiotics.

Extended-Spectrum β-Lactamases and/or Carbapenemases-Producing Enterobacteriaceae Isolated from Retail Chicken Meat in Zagazig, Egypt

OBJECTIVES

The aim of the present study was to determine the prevalence and to characterize extended-spectrum β-lactamases- and/or carbapenemases-producing Enterobacteriaceae among Enterobacteriaceae isolated from retail chicken meat in Zagazig, Egypt.

METHODS

One hundred and six Enterobacteriaceae isolates were collected from retail chicken meat samples purchased in Zagazig, Egypt in 2013. Species identification was done by MALDI-TOF MS. Screening for ESBL-E was performed by inoculation of isolates recovered from meat samples onto the EbSA (Cepheid Benelux, Apeldoorn, the Netherlands) selective screening agar. ESBL production was confirmed by combination disc diffusion test with clavulanic acid (Rosco, Taastrup, Denmark). Carbapenemases production was confirmed with double disk synergy tests. Resistance genes were characterized by PCR with specific primers for TEM, SHV, and CTX-M and carbapenemases (KPC, NDM, OXA-48, IMP and VIM). PCR products of CTX-M genes were purified and sequenced. Phylogenetic grouping of E. coli was performed by a PCR-based method.

RESULTS

Of these 106 isolates 69 (65.09%) were ESBL producers. Twelve (11.32%) of these isolates were also phenotypically class B carbapenemases producer. TEM genes were detected in 61 (57.55%) isolates. 49 (46.23%) isolates harbored CTX-M genes, and 25 (23.58%) carried genes of the SHV family. All CPE belonged to the NDM group. The predominant CTX-M sequence type was CTX-M-15 (89.80%). The majority (80%) of the ESBL-EC belonged to low virulence phylogroups A and B1.

CONCLUSIONS

This is the first study from Egypt reporting high rates of ESBLs and carbapenemases (65.09% and 11.32%, respectively) in Enterobacteriaceae isolated from retail chicken meat. These results raise serious concerns about public health and food safety as retail meat could serve as a reservoir for these resistant bacteria which could be transferred to humans through the food chain.

Epidemiology and risk factors for faecal extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) carriage derived from residents of seven nursing homes in western Shanghai, China

Nursing homes (NHs) have been implicated as significant reservoirs of antibiotic-resistant organisms causing severe infectious disease. We investigated the prevalence and molecular epidemiology of, and risk factors for, faecal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E). A multicentre cross-sectional study was conducted in seven NHs in Shanghai between March 2014 and May 2014. Antimicrobial susceptibility testing and polymerase chain reaction were used to detect genes coding for ESBLs and carbapenemases. NH records at individual-resident level and facility level were examined for potential risk factors. Four hundred and fifty-seven Enterobacteriaceae isolates were collected of which 183 (46·92%) were colonized by ESBL-E. CTX-M enzymes (198/200, 99%) predominated, with CTX-M-14 (84/200, 42%) the most common types. Two carbapenemase producers harboured blaKPC-2. Resistance rates to carbapenems, TZP, AK, FOS, CL and TGC were low. History of invasive procedures [odds ratio (OR) 2·384, 95% confidence interval (CI) 1·318-4·310, P = 0·004], narrow-spectrum cephalosporins (OR 1·635, 95% CI 1·045-2·558, P = 0·031) and broad-spectrum cephalosporins (OR 3·276, 95% CI 1·278-8·398, P = 0·014) were independently associated with ESBL-E carriage. In conclusion, NH residents have a very high prevalence of faecal carriage of ESBL-E. Continuous and active surveillance is important, as are prudent infection control measures and antibiotic use to prevent and control the spread of these antibiotic-resistant strains.

Molecular Typing of Enterobacteriaceae from Pig Holdings in North-Western Germany Reveals Extended- Spectrum and AmpC β-Lactamases Producing but no Carbapenem Resistant Ones

The increase of extended- spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) in humans and in food-producing animals is of public health concern. The latter could contribute to spreading of these bacteria or their resistance genes to humans. Several studies have reported the isolation of third generation cephalosporin resistant bacteria in livestock animals. However, the number of samples and the methodology used differ considerably between studies limiting comparability and prevalence assessment. In the present study, a total of 564 manure and dust samples were collected from 47 pig farms in Northern Germany and analysed to determine the prevalence of ESBL-E. Molecular typing and characterization of resistance genes was performed for all ESBL-E isolates. ESBL-E isolates were found in 55.3% of the farms. ESBL-Escherichia coli was found in 18.8% of the samples, ESBL-Klebsiella pneumoniae in 0.35%. The most prevalent ESBL genes among E. coli were CTX-M-1 like (68.9%), CTX-M-15 like (16%) and CTX-M-9 group (14.2%). In 20% of the latter two, also the OXA-1 like gene was found resulting in a combination of genes typical for isolates from humans. Genetic relation was found between isolates not only from the same, but also from different farms, with multilocus sequence type (ST) 10 being predominant among the E. coli isolates. In conclusion, we showed possible spread of ESBL-E between farms and the presence of resistance genes and STs previously shown to be associated with human isolates. Follow-up studies are required to monitor the extent and pathways of ESBL-E transmission between farms, animals and humans.

Characterization of Escherichia coli-Producing Extended-Spectrum β-Lactamase (ESBL) Isolated from Chicken Slaughterhouses in South Korea

In South Korea, few reports have indicated the occurrence and characteristics of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in food-producing animals, particularly in poultry slaughterhouses. In this study, we investigated the occurrence and antibiotic resistance of ESBL-producing E. coli from whole chicken carcasses (n=156) and fecal samples (n=39) of chickens obtained from 2 slaughterhouses. Each sample enriched in buffered peptone water was cultured on MacConkey agar with 2 mg/L cefotaxime and ESBL agar. ESBL production and antibiotic susceptibility were determined using the Trek Diagnostics system. The ESBL genotypes were determined by polymerase chain reaction (PCR) using the bla(SHV), bla(TEM), and bla(CTX-M) gene sequences. Subtyping using a repetitive sequence-based PCR system (DiversiLab™) and multilocus sequence typing (MLST) were used to assess the interspecific biodiversity of isolates. Sixty-two ESBL-producing E. coli isolates were obtained from 156 samples (39.7%). No bla(SHV) genes were detected in any of the isolates, whereas all contained the bla(TEM) gene. Twenty-five strains (40.3%) harbored the CTX-M group 1 gene. The most prevalent MLST sequence type (ST) was ST 93 (14.5%), followed by ST 117 (9.7%) and ST 2303 (8.1%). This study reveals a high occurrence and β-lactams resistance rate of E. coli in fecal samples and whole chickens collected from slaughterhouses in South Korea.

Prevalence and risk factors for carriage of antimicrobial-resistant Escherichia coli on household and small-scale chicken farms in the Mekong Delta of Vietnam

OBJECTIVES

To describe the prevalence of antimicrobial resistance among commensal Escherichia coli isolates on household and small-scale chicken farms, common in southern Vietnam, and to investigate the association of antimicrobial resistance with farming practices and antimicrobial usage.

METHODS

We collected data on farming and antimicrobial usage from 208 chicken farms. E. coli was isolated from boot swab samples using MacConkey agar (MA) and MA with ceftazidime, nalidixic acid or gentamicin. Isolates were tested for their susceptibility to 11 antimicrobials and for ESBL production. Risk factor analyses were carried out, using logistic regression, at both the bacterial population and farm levels.

RESULTS

E. coli resistant to gentamicin, ciprofloxacin and third-generation cephalosporins was detected on 201 (96.6%), 191 (91.8%) and 77 (37.0%) of the farms, respectively. Of the 895 E. coli isolates, resistance to gentamicin, ciprofloxacin and third-generation cephalosporins was detected in 178 (19.9%), 291 (32.5%) and 29 (3.2%) of the isolates, respectively. Ciprofloxacin resistance was significantly associated with quinolone usage (OR = 2.26) and tetracycline usage (OR = 1.70). ESBL-producing E. coli were associated with farms containing fish ponds (OR = 4.82).

CONCLUSIONS

Household and small farms showed frequent antimicrobial usage associated with a high prevalence of resistance to the most commonly used antimicrobials. Given the weak biocontainment, the high prevalence of resistant E. coli could represent a risk to the environment and to humans.

Carriage of extended-spectrum β-lactamases in pig farmers is associated with occurrence in pigs

Livestock may serve as a reservoir for extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE). The objectives of this study were to determine the prevalence of carriage with ESBL-PE in pig farmers, family members and employees, and its association with carriage in pigs. Rectal swabs were taken from 2388 pigs (398 pooled samples) on 40 pig farms and faecal samples were obtained from 142 humans living or working on 34 of these farms. Presence of ESBL-PE was determined by selective plating (agar). ESBL genes were analysed by PCR or microarray analysis, and gene sequencing. Genotypes and plasmids were determined by multilocus sequence typing and PCR-based replicon typing for selected isolates. ESBL genes were detected in Escherichia coli from eight humans (6%) (blaCTX-M-1, n = 6; blaTEM-52, n = 1 and blaCTX-M-14, n = 1) on six farms. In 157 pig isolates (107 pooled samples) on 18 farms (45%) ESBL genes were detected (blaCTX-M-1, n = 12; blaTEM-52, n = 6; and blaCTX-M-14, n = 3). Human and pig isolates within the same farm harboured similar ESBL gene types and had identical sequence and plasmid types on two farms (e.g. E. coli ST-453, blaCTX-M-1, IncI1), suggesting clonal transmission. For the remaining farms, sequence types, but not plasmid types, differed. Human ESBL carriage was associated with average number of hours working on the farm per week (OR = 1.04, 95% CI 1.02-1.06) and presence of ESBLs in pigs (OR = 12.5, 95% CI 1.4-111.7). Daily exposure to pigs carrying ESBL-PE is associated with ESBL carriage in humans.

Improved detection of extended spectrum beta-lactamase (ESBL)-producing Escherichia coli in input and output samples of German biogas plants by a selective pre-enrichment procedure

The presence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli was investigated in input (manure from livestock husbandry) and output samples of six German biogas plants in 2012 (one sampling per biogas plant) and two German biogas plants investigated in an annual cycle four times in 2013/2014. ESBL-producing Escherichia coli were cultured by direct plating on CHROMagar ESBL from input samples in the range of 10⁰ to 10⁴ colony forming units (CFU) per g dry weight but not from output sample. This initially indicated a complete elimination of ESBL-producing E. coli by the biogas plant process. Detected non target bacteria were assigned to the genera Acinetobacter, Pseudomonas, Bordetella, Achromobacter, Castellaniella, and Ochrobactrum. A selective pre-enrichment procedure increased the detection efficiency of ESBL-producing E. coli in input samples and enabled the detection in five of eight analyzed output samples. In total 119 ESBL-producing E. coli were isolated from input and 46 from output samples. Most of the E. coli isolates carried CTX-M-type and/or TEM-type beta lactamases (94%), few SHV-type beta lactamase (6%). Sixty-four bla_CTX-M genes were characterized more detailed and assigned mainly to CTX-M-groups 1 (85%) and 9 (13%), and one to group 2. Phylogenetic grouping of 80 E. coli isolates showed that most were assigned to group A (71%) and B1 (27%), only one to group D (2%). Genomic fingerprinting and multilocus sequence typing (MLST) showed a high clonal diversity with 41 BOX-types and 19 ST-types. The two most common ST-types were ST410 and ST1210. Antimicrobial susceptibility testing of 46 selected ESBL-producing E. coli revealed that several isolates were additionally resistant to other veterinary relevant antibiotics and some grew on CHROMagar STEC but shiga-like toxine (SLT) genes were not detected. Resistance to carbapenems was not detected. In summary the study showed for the first time the presence of ESBL-producing E. coli in output samples of German biogas plants.

Drug susceptibility and molecular epidemiology of Escherichia coli in bloodstream infections in Shanghai, China, 2011-2013

BACKGROUND

Prevention and management of Escherichia coli bloodstream infections (EC-BSIs) have become increasingly complicated by antimicrobial resistance and rapid dissemination. We investigated the antimicrobial epidemiology and phylogenetic background of clinical E. coli isolates from patients with bloodstream infections in Shanghai from 2011 to 2013.

METHODS

Escherichia coli isolates causing bloodstream infections were consecutively collected between June 2011 and June 2013. Antimicrobial susceptibility testing was performed by disk diffusion. Drug resistance genes coding for extended-spectrum β-lactamases (ESBLs) and carbapenemases, and phylogenetic groups were detected by polymerase chain reaction. eBURST was used for multilocus sequence typing.

RESULTS

Of the strains 128 collected, 80 produced ESBLs. No carbapenem-resistant isolates were found. The resistance rates to penicillins, fluoroquinolone, folate pathway inhibitors, tetracyclines and second generation cephalosporins were high. Molecular analysis showed that CTX-M-14 (40/80) was the most common β-lactamase, followed by CTX-M-55 (17/80) and CTX-M-15 (14/80). Phylogenetic group B2 predominated (37.5%), but phylogenetic group D exhibited the highest rates of ESBL production. ST131 (17/128) was the most common sequence type, followed by ST69 (12/128) and ST648 (10/128).

CONCLUSIONS

The antimicrobial resistance rate was high among EC-BSI isolates, but amikacin, piperacillin-tazobactam and carbapenem could be options for empiric therapy. Genetic diversity showed no correlation with the nosocomial origin of the isolates.

Multiresistant bacteria isolated from chicken meat in Austria

Multidrug resistant bacteria (MDR bacteria), such as extended spectrum beta-lactamase (ESBL) Enterobacteriaceae, methicillin resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococci (VRE), pose a challenge to the human health care system. In recent years, these MDR bacteria have been detected increasingly outside the hospital environment. Also the contamination of food with MDR bacteria, particularly of meat and meat products, is a concern. The aim of the study was to evaluate the occurrence of MDR bacteria in chicken meat on the Austrian market. For this study, 50 chicken meat samples were analysed. All samples originated from chickens slaughtered in Austrian slaughterhouses and were marked as produced in Austria. Samples were analysed for the presence of ESBL Enterobacteriaceae, methicillin resistant Staphylococci and VRE. Resistance genes of the isolated bacteria were characterised by PCR and sequencing. In the present study 26 ESBL producing E. coli, five mecA gene harbouring Staphylococci (but no MRSA), and four VRE were detected in chicken meat samples of Austrian origin. In 24 (48%) of the samples no ESBL Enterobacteriaceae, MRSA, methicillin resistant coagulase negative Staphylococcus (MRCNS) or VRE could be detected. None of the samples contained all three types of investigated multiresistant bacteria. In concordance to previous studies, CTX-M-1 and SHV-12 were the dominant ESBL genes.

Extended-spectrum β-lactamase-producing Enterobacteriaceae in hospital food: a risk assessment

OBJECTIVE

Determine the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-PE) contamination of food and colonization of food handlers in a hospital kitchen and compare retrieved ESBL-PE strains with patient isolates.

DESIGN

Cross-sectional study.

SETTING

A 2,200-bed tertiary care university hospital in Switzerland.

PARTICIPANTS

Food handlers.

METHODS

Raw and prepared food samples were obtained from the hospital kitchen, with a comparator group from local supermarkets. Fecal samples collected from food handlers and selectively pre-enriched homogenized food samples were inoculated onto selective chromogenic media. Phenotypic confirmation of ESBL production was performed using the double disk method. Representative ESBL-PE were characterized using polymerase chain reaction (PCR) and sequencing for blaCTX-M, blaSHV, and blaTEM genes, and Escherichia coli strains were typed using phylotyping, repetitive element palindromic PCR, and multilocus sequence typing. Meat samples were screened for antibiotic residues using liquid chromatography time-of-flight mass spectrometry.

RESULTS

Sixty (92%) of the raw chicken samples were ESBL-PE positive, including 30 (86%) of the hospital samples and all supermarket samples. No egg, beef, rabbit, or cooked chicken samples were ESBL-PE positive. No antibiotic residues were detected. Six (6.5%) of 93 food handlers were ESBL-PE carriers. ESBL-PE strains from chicken meat more commonly possessed blaCTX-M-1 and blaCTX-M-2, whereas blaCTX-M-14 and blaCTX-M-15 were predominant among strains of human origin. There was partial overlap in the sequence type of E. coli strains of chicken and human origin. No E. coli ST131 strains or blaCTX-M-15 genes were isolated from meat.

CONCLUSIONS

Although there is significant ESBL-PE contamination of delivered chicken meat, current preventive strategies minimize risks to food handlers, hospital staff, and patients.

Infection control issues in patients with haematological malignancies in the era of multidrug-resistant bacteria

Drug-resistant Gram-negative and Gram-positive bacteria are now increasingly identified as a cause of infections in immunocompromised hosts. Bacteria identified include the multidrug-resistant (MDR) and even pandrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa, as well as carbapenem-resistant Enterobacteriaceae spp. The threat from MDR pathogens has been well-documented in the past decade with warnings about the consequences of inappropriate use of antimicrobial drugs. Resistant bacteria can substantially complicate the treatment of infections in critically ill patients and can have a substantial effect on mortality. Inappropriate antimicrobial treatment can affect morbidity, mortality, and overall health-care costs. Evidence-based data for prevention and control of MDR pathogen infections in haematology are scarce. Although not yet established a bundle of infection control and prevention measures with an anti-infective stewardship programme is an important strategy in infection control, diagnosis, and antibiotic selection with optimum regimens to ensure a successful outcome for patients.

The risk to import ESBL-producing Enterobacteriaceae and Staphylococcus aureus through chicken meat trade in Gabon

Background

A main export market for chicken meat from industrialized countries is sub-Saharan Africa. We hypothesized that antibiotic resistant bacteria could be exported to developing countries through chicken meat trade. The objective was to investigate the occurrence and molecular types of ESBL-producing Enterobacteriaceae and Staphylococcus aureus in chicken meat in Gabon and to assess their dissemination among humans.

Results

Frozen chicken meat samples imported from industrialized countries to Gabon (n = 151) were screened for ESBL-producing Enterobacteriaceae and S. aureus. Genotypes and resistance genes (SHV, TEM, CTX-M, CMY-2) of isolates from meat were compared with isolates derived from humans.

The contamination rate per chicken part (i. e. leg, wing) with ESBL-producing Escherichia coli (ESBL E. coli, no other ESBL-producing Enterobacteriaceae were found) and S. aureus was 23% and 3%, respectively. The beta-lactamase CTX-M 1 was predominant in ESBL E. coli from meat samples but was not found in isolates from cases of human colonization or infection. S. aureus belonging to spa type t002 (multilocus sequence type ST5) were found both in chicken meat and humans.

Conclusion

There is a risk to import ESBL E. coli to Gabon but molecular differences between isolates from humans and chicken meat argue against a further dissemination. No MRSA isolate was detected in imported chicken meat.

Antibiotic resistance and phylogenetic characterization of Acinetobacter baumannii strains isolated from commercial raw meat in Switzerland

The spread of antibiotic-resistant bacteria through food has become a major public health concern because some important human pathogens may be transferred via the food chain. Acinetobacter baumannii is one of the most life-threatening gram-negative pathogens; multidrug-resistant (MDR) clones of A. baumannii are spreading worldwide, causing outbreaks in hospitals. However, the role of raw meat as a reservoir of A. baumannii remains unexplored. In this study, we describe for the first time the antibiotic susceptibility and fingerprint (repetitive extragenic palindromic PCR [rep-PCR] profile and sequence types [STs]) of A. baumannii strains found in raw meat retailed in Switzerland. Our results indicate that A. baumannii was present in 62 (25.0%) of 248 (CI 95%: 19.7 to 30.9%) meat samples analyzed between November 2012 and May 2013, with those derived from poultry being the most contaminated (48.0% [CI 95%: 37.8 to 58.3%]). Thirty-nine strains were further tested for antibiotic susceptibility and clonality. Strains were frequently not susceptible (intermediate and/or resistant) to third- and fourth-generation cephalosporins for human use (i.e., ceftriaxone [65%], cefotaxime [32%], ceftazidime [5%], and cefepime [2.5%]). Resistance to piperacillin-tazobactam, ciprofloxacin, colistin, and tetracycline was sporadically observed (2.5, 2.5, 5, and 5%, respectively), whereas resistance to carbapenems was not found. The strains were genetically very diverse from each other and belonged to 29 different STs, forming 12 singletons and 6 clonal complexes (CCs), of which 3 were new (CC277, CC360, and CC347). RepPCR analysis further distinguished some strains of the same ST. Moreover, some A. baumannii strains from meat belonged to the clonal complexes CC32 and CC79, similar to the MDR isolates responsible for human infections. In conclusion, our findings suggest that raw meat represents a reservoir of MDR A. baumannii and may serve as a vector for the spread of these pathogens into both community and hospital settings.