Dutch patients, retail chicken meat and poultry share the same ESBL genes, plasmids and strains

Intestinal carriage of extended-spectrum beta-lactamase (ESBL) -producing bacteria in food-producing animals and contamination of retail meat may contribute to increased incidences of infections with ESBL-producing bacteria in humans. Therefore, distribution of ESBL genes, plasmids and strain genotypes in Escherichia coli obtained from poultry and retail chicken meat in the Netherlands was determined and defined as ‘poultry-associated’ (PA). Subsequently, the proportion of E. coli isolates with PA ESBL genes, plasmids and strains was quantified in a representative sample of clinical isolates. The E. coli were derived from 98 retail chicken meat samples, a prevalence survey among poultry, and 516 human clinical samples from 31 laboratories collected during a 3-month period in 2009. Isolates were analysed using an ESBL-specific microarray, sequencing of ESBL genes, PCR-based replicon typing of plasmids, plasmid multi-locus sequence typing (pMLST) and strain genotyping (MLST). Six ESBL genes were defined as PA (blaCTX-M-1, blaCTX-M-2, blaSHV-2, blaSHV-12, blaTEM-20, blaTEM-52): 35% of the human isolates contained PA ESBL genes and 19% contained PA ESBL genes located on IncI1 plasmids that were genetically indistinguishable from those obtained from poultry (meat). Of these ESBL genes, 86% were blaCTX-M-1 and blaTEM-52 genes, which were also the predominant genes in poultry (78%) and retail chicken meat (75%). Of the retail meat samples, 94% contained ESBL-producing isolates of which 39% belonged to E. coli genotypes also present in human samples. These findings are suggestive for transmission of ESBL genes, plasmids and E. coli isolates from poultry to humans, most likely through the food chain

Multi-centre evaluation of a phenotypic extended spectrum β-lactamase detection guideline in the routine setting

AbstractThis study aimed to evaluate the routine setting performance of a guideline for phenotypic detection of extended spectrum β-lactamases (ESBLs) in Enterobacteriaceae, recommending ESBL confirmation with Etest or combination disc for isolates with a positive ESBL screen test (i.e. cefotaxime and/or ceftazidime MIC >1 mg/L or an automated system ESBL warning). Twenty laboratories submitted 443 Enterobacteriaceae with a positive ESBL screen test and their confirmation test result (74% Escherichia coli, 12% Enterobacter cloacae, 8% Klebsiella pneumoniae, 3% Proteus mirabilis, 2% Klebsiella oxytoca). Presence of ESBL genes was used as reference test. Accuracy of local phenotypic ESBL detection was 88%. The positive predictive value (PPV) of local screen tests was 70%, and differed per method (Vitek-2: 69%, Phoenix: 68%, disc diffusion: 92%), and species (95% K. pneumoniae-27% K. oxytoca). A low PPV (3%) was observed for isolates with automated system alarm but third-generation cephalosporin MICs <2 mg/L. Local ESBL confirmation had a PPV and negative predictive value (NPV) of 93% and 90%, respectively. Compared with centrally performed confirmation tests, 7% of local tests were misinterpreted. Combination disc was more specific than Etest (91% versus 61%). Confirmation tests were not reliable for P. mirabilis and K. oxytoca (PPV 33% and 38%, respectively, although NPVs were 100%). In conclusion, performance of Etests could be enhanced by education of technicians to improve their interpretation, by genotypic ESBL confirmation of P. mirabilis and K. oxytoca isolates with positive phenotypic ESBL confirmation, and by interpreting isolates with a positive ESBL alarm but an MIC <2 mg/L for cefotaxime and ceftazidime as ESBL-negative

The vaginal microbiota in the course of bacterial vaginosis treatment

Bacterial vaginosis (BV) is perceived as a condition of disrupted vaginal microbiota, but remains of unknown aetiology. In this study, vaginal microbiota composition was determined in twenty-one women with BV, before and after treatment with metronidazole or clindamycin. Microbiota composition varied greatly between women and defining a (un)healthy vaginal microbiota state remains elusive, challenging BV diagnosis and treatment. While relative abundance ofLactobacillusincreased after antibiotic treatment in two-third of women, its abundance was not associated with treatment outcome. Instead, remaining complaints of abnormal vaginal discharge were more common after metronidazole treatment and associated with increased relative abundance ofUreaplasma.Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc

National laboratory-based surveillance system for antimicrobial resistance: a successful tool to support the control of antimicrobial resistance in the Netherlands

An important cornerstone in the control of antimicrobial resistance (AMR) is a well-designed quantitative system for the surveillance of spread and temporal trends in AMR. Since 2008, the Dutch national AMR surveillance system, based on routine data from medical microbiological laboratories (MMLs), has developed into a successful tool to support the control of AMR in the Netherlands. It provides background information for policy making in public health and healthcare services, supports development of empirical antibiotic therapy guidelines and facilitates in-depth research. In addition, participation of the MMLs in the national AMR surveillance network has contributed to sharing of knowledge and quality improvement. A future improvement will be the implementation of a new semantic standard together with standardised data transfer, which will reduce errors in data handling and enable a more real-time surveillance. Furthermore, the

Guideline for phenotypic screening and confirmation of carbapenemases in Enterobacteriaceae

Adequate detection of carbapenemase-producing Enterobacteriaceae is crucial for infection control measures and appropriate choice of antimicrobial therapy. This guideline aims to improve the detection of carbapenemase-producing Enterobacteriaceae in the routine setting of clinical microbiology laboratories. Detection of carbapenemases in Enterobacteriaceae includes a screening step followed by a genotypic and optional phenotypic confirmatory step. For all Enterobacteriaceae, the meropenem screening breakpoint to detect carbapenemases is set at >or=0.5mg/L or a zone diameter of <or=23 mm (10 microg disk loading). For Escherichia coli, Klebsiella spp., Salmonella spp., Enterobacter spp. and Citrobacter spp., the imipenem screening breakpoint is set at >or=2mg/L or a zone diameter <or=21 mm. Ertapenem is not advised as an indicator carbapenem as it has a lower specificity compared with imipenem and meropenem. On the first isolate from a patient with a positive carbapenemase screen test, a polymerase chain reaction (PCR)-based test should be performed to detect carbapenemase genes. However, if genotypic confirmation is not immediately available, phenotypic confirmation tests should be performed to avoid delayed reporting of carbapenemase-producers to the clinic. Recommended phenotypic confirmation tests are the modified Hodge test as well as carbapenemase inhibition tests with boronic acid for Ambler class A carbapenemases and with ethylene diamine tetra-acetic acid (EDTA) or dipicolinic acid for metallo-carbapenemases

[Optimalisation of the antibiotic policy in The Netherlands. XI. The national electronic antibiotic guide'SWAB-ID' for use in hospitals],Optimaliseren van het antibioticabeleid in Nederland. XI. Het nationale elektronische antibioticaboekje SWAB-ID voor ziekenhuizen.

Item does not contain fulltextThe 'Stichting Werkgroep Antibioticabeleid' (Dutch Working Party on Antibiotic Policy) has developed an electronic national antibiotic guide for the antibiotic treatment and prophylaxis of common infectious diseases in hospitals. This guide also contains information on the most important characteristics of antimicrobial drugs. Advice on antibiotic treatment is based on existing national evidence-based guidelines, where available. Where no guideline is available, the advice is based on an inventory of the antibiotic policies of the 12 Dutch centres with an infectious disease or medical microbiology training programme. The national antibiotic guide can be accessed through the SWAB website (www.swab.nl) and can also be downloaded on PDA/PocketPC, free of charge. Every hospital antibiotic formulary committee in the Netherlands will be offered the opportunity to edit The national version for local use

[Optimalisation of the antibiotic policy in The Netherlands. XI. The national electronic antibiotic guide'SWAB-ID' for use in hospitals]

The 'Stichting Werkgroep Antibioticabeleid' (Dutch Working Party on Antibiotic Policy) has developed an electronic national antibiotic guide for the antibiotic treatment and prophylaxis of common infectious diseases in hospitals. This guide also contains information on the most important characteristics of antimicrobial drugs. Advice on antibiotic treatment is based on existing national evidence-based guidelines, where available. Where no guideline is available, the advice is based on an inventory of the antibiotic policies of the 12 Dutch centres with an infectious disease or medical microbiology training programme. The national antibiotic guide can be accessed through the SWAB website (www.swab.nl) and can also be downloaded on PDA/PocketPC, free of charge. Every hospital antibiotic formulary committee in the Netherlands will be offered the opportunity to edit The national version for local use

Identification of resistance and virulence factors in an epidemic Enterobacter hormaechei outbreak strain

Bacterial strains differ in their ability to cause hospital outbreaks. Using comparative genomic hybridization, Enterobacter cloacae complex isolates were studied to identify genetic markers specific for Enterobacter cloacae complex outbreak strains. No outbreak-specific genes were found that were common in all investigated outbreak strains. Therefore, the aim of our study was to identify specific genetic markers for an Enterobacter hormaechei outbreak strain (EHOS) that caused a nationwide outbreak in The Netherlands. Most EHOS isolates carried a large conjugative plasmid (pQC) containing genes encoding heavy-metal resistance, mobile elements, pili-associated proteins and exported proteins as well as multiple-resistance genes. Furthermore, the chromosomally encoded high-pathogenicity island (HPI) was highly associated with the EHOS strain. In addition, other DNA fragments were identified that were associated with virulence: three DNA fragments known to be located on a virulence plasmid (pLVPK), as well as phage- and plasmid-related sequences. Also, four DNA fragments encoding putative pili with the most homology to pili of Salmonella enterica were associated with the EHOS. Finally, four DNA fragments encoding putative outer-membrane proteins were negatively associated with the EHOS. In conclusion, resistance and putative virulence genes were identified in the EHOS that may have contributed to increased epidemicity. The high number of genes detected in the EHOS that were related to transferable elements reflects the genomic plasticity of the E. cloacae complex and may explain the emergence of the EHOS in the hospital environment. © 2009 SGM