Cross-border differences in the prevalence and risk factors for carriage of antimicrobial resistance in children attending daycare centers: a point prevalence study in the Netherlands and Belgium.

BACKGROUND: Day care centres (DCCs) are ideal settings for drug-resistant bacteria to emerge. Prevalence numbers of faecal carriage of antimicrobial resistant bacteria in these settings are rare. We aimed to determine the prevalence of faecal antimicrobial resistant bacteria carriage in children attending DCCs and to assess and identify infection risk factors within DCCs in The Netherlands and Belgium. METHODS: A point-prevalence study was conducted in 28 Dutch (499 children) and 18 Belgian (448 children) DCCs. Stool samples were taken from the children's diapers and a questionnaire was filled in by their parents. Hygiene related to stool and toilet use, hygiene related to food, environmental contamination, hand hygiene and hygiene guidelines were assessed conform a standardized questionnaire by the infection prevention and control expert visiting the DCC. Multilevel logistical regression analyses were used to define which characteristics predicted the presence of extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenemase-producing Enterobacterales (CPE), vancomycin-resistant enterococci (VRE), and ciprofloxacin-resistant Enterobacterales (CipR-E). RESULTS: The ESBL-E prevalence was 16% (n = 71) in Belgium and 6% (n = 30) in the Netherlands. The CipR-E prevalence was 17% (n = 78) in Belgium and 8% (n = 38) in the Netherlands. Antimicrobial use (RR: 0.30; 95% CI: 0.33-0.48) and hospital admissions (RR: 0.37; 95% CI: 0.25-0.54) were lower in the Netherlands. Children travelling to Asia were at higher risk of being an ESBL-E carrier. Children using antimicrobials were at higher risk of being a CipR-E carrier. Cleaning the changing mat after each use was found as a protective factor for CipR-E carriage. CONCLUSIONS: We established a significant difference in ESBL-E and CipR-E carriage and antimicrobial use and hospital admissions between the Netherlands and Belgium among children attending DCCs. The differences between both countries should be further studied to improve the policy on anti-microbial use and hospital admissions in children.

Implementation of the Infection Risk Scan (IRIS) in nine hospitals in the Belgian-Dutch border region (i-4-1-Health project).

BACKGROUND: A tool, the Infection Risk Scan has been developed to measure the quality of infection control and antimicrobial use. This tool measures various patient-, ward- and care-related variables in a standardized way. We describe the implementation of this tool in nine hospitals in the Dutch/Belgian border area and the obtained results. METHODS: The IRIS consists of a set of objective and reproducible measurements: patient comorbidities, (appropriate) use of indwelling medical devices, (appropriate) use of antimicrobial therapy, rectal carriage of Extended-spectrum beta-lactamase producing Enterobacterales and their clonal relatedness, environmental contamination, hand hygiene performance, personal hygiene of health care workers and presence of infection prevention preconditions. The Infection Risk Scan was implemented by an expert team. In each setting, local infection control practitioners were trained to achieve a standardized implementation of the tool and an unambiguous assessment of data. RESULTS: The IRIS was implemented in 34 wards in six Dutch and three Belgian hospitals. The tool provided ward specific results and revealed differences between wards and countries. There were significant differences in the prevalence of ESBL-E carriage between countries (Belgium: 15% versus The Netherlands: 9.6%), environmental contamination (median adenosine triphosphate (ATP) level Belgium: 431 versus median ATP level The Netherlands: 793) and calculated hand hygiene actions based on alcohol based handrub consumption (Belgium: 12.5/day versus The Netherlands: 6.3/day) were found. CONCLUSION: The Infection risk Scan was successfully implemented in multiple hospitals in a large cross-border project and provided data that made the quality of infection control and antimicrobial use more transparent. The observed differences provide potential targets for improvement of the quality of care.

Feedback of ATP measurement as a tool for reducing environmental contamination in hospitals in the Dutch/Belgian border area.

DESIGN: A two-phase prospective intervention study. OBJECTIVE: The objective of this study was to determine if feedback of adenosine triphosphate (ATP) measurements decreases environmental contamination within hospitals in the Dutch/Belgian border area. METHODS: Standardized ATP measurements were conducted in nine hospitals on pre-defined fomites. Four different fomite groups were defined: medical devices, patient-bound materials, ward-bound materials and sanitary items. ATP results were reported in relative light unit (RLU), RLU >1000 was considered as 'not clean.' Two rounds of ATP measurements were conducted. After the first round of ATP measurements, results were provided to the wards and cleaning staff. The second round of ATP measurements was performed one year later. The amount of surface contamination before and after the feedback was compared. RESULTS: In total 1923 ATP measurements were performed. Before feedback 960 ATP measurements were conducted and after feedback 963 were conducted. The overall median reduction in RLU was 381 (P < 0.001), from 568 before feedback to 187 afterward. In each hospital there was a reduction of the median RLU after feedback. CONCLUSIONS: Substantial reductions in RLU values were found after feedback of ATP measurements. Feedback of ATP measurement in itself was associated with a major reduction of surface contamination in hospitals.

The correlation between ATP measurement and microbial contamination of inanimate surfaces.

BACKGROUND: The objective of this study was to determine the correlation between adenosine triphosphate (ATP) measurements and microbial contamination using a standardized method. Secondarily, analyzing reproducibility of ATP measurements and aerobic colony counts (ACC's) on the same surface. METHODS: ATP measurements and ACC's were conducted on 10 pre-defined fomites in a hospital and nursing home setting. Per fomite two ATP measurements and two agar plate measurements were conducted, each measurement was conducted on a 25 cm2 surface. Both measurements were compared and analyzed for correlation. RESULTS: In total 200 paired measurements were conducted, 200 ATP measurements and 200 ACC's. The mean of all ATP measurements tested on the same surface was calculated, as was for all 200 ACC's. There was a strong correlation between the mean of two ATP measurements on two different sites on the same fomite (R = 0.800, p < 0.001) as well as between two ACC measurements on the same fomite (R = 0.667, p < 0.001). A much weaker correlation was found between RLU values and ACC's (R = 0.244, p < 0.001). CONCLUSIONS: Reproducibility of ATP measurements and ACC's on the same fomite was good. However, the correlation between RLU values and ACC's on hospital surfaces was much lower. This may be explained by the wide variety of biological material that is measured with ATP, of which the bacterial load is only one of many components. ATP measurement can be used to give a quantifiable outcome for the rating of cleanliness in health care facilities, however the results cannot be translated into the level of microbial contamination.

ATP measurement as an objective method to measure environmental contamination in 9 hospitals in the Dutch/Belgian border area.

BACKGROUND: The objective of this study was to determine the level of environmental contamination in hospitals in the Dutch/Belgian border area, using ATP measurements. DESIGN: A cross-sectional observational survey. METHODS: Standardized ATP measurements were conducted in 9 hospitals on 32 hospital wards. Thirty pre-defined surfaces per hospital ward were measured with the 3 M Clean Trace NG luminometer. Results are displayed in relative light units (RLU). RLU > 1000 was considered as "not clean." Differences in RLU values were compared between countries, hospitals, fomite groups and medical specialties. RESULTS: A total of 960 ATP measurements were performed, ranging from 60 up to 120 per hospital. The median RLU-value was 568 (range: 3-277,586) and 37.7% of the measurements were rated as not clean (RLU > 1000). There were significant differences between countries, hospitals and fomite groups. CONCLUSION: ATP measurements can be used as a more objective approach to determine the level of environmental contamination in hospitals. Significant differences in ATP levels were found between hospitals and between countries. Also, substantial differences were found between different fomite groups. These findings offer potential targets for improvement of cleanliness in healthcare facilities.

Comparison of infection control practices in a Dutch and US hospital using the infection risk scan (IRIS) method.

BACKGROUND: The infection risk scan (IRIS) is a tool to measure the quality of infection control (IC) and antimicrobial use in a standardized way. We describe the feasilibility of the IRIS in a Dutch hospital (the Netherlands, NL) and a hospital in the United States (US). METHODS: Cross-sectional measurements were performed. Variables included a hand hygiene indicator, environmental contamination, IC preconditions, personal hygiene of health care workers, use of indwelling medical devices, and use of antimicrobials. RESULTS: IRIS was performed in 2 wards in a US hospital and 4 wards in a Dutch hospital. Unjustified use of medical devices: none in the US hospital, 2.2% in the Dutch hospital; inappropriate use of antibiotics: 11.7% (US), 19% (NL); items considered not clean: 10% (US); 36% (NL); shortcomings preconditions: 6 of 20 (US), 6 of 40 (NL); health care workers with rings, watches, or long sleeves: 34 of 43 (US), none in the NL hospital; and hand hygiene actions per patient/day: 41 (US) and 10 (NL). US data judged against the Dutch guidelines and vice versa revealed remarkable differences. CONCLUSIONS: We showed the feasibility of using the IRIS in a US hospital. The method provided insight in IC local performance. This method could be the first step to standardize the measurement of the quality of IC and antimicrobial use. However, if the IRIS is used for benchmarking between hospitals in different regions, this should be done in the context of regional guidelines and policies.

High prevalence of multidrug resistant Enterobacteriaceae among residents of long term care facilities in Amsterdam, the Netherlands.

INTRODUCTION: The aim of this study was to determine the rate of asymptomatic carriage and spread of multidrug-resistant micro-organisms (MDRO) and to identify risk factors for extended spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) carriage in 12 long term care facilities (LTCFs) in Amsterdam, the Netherlands. MATERIALS AND METHODS: From November 2014 to august 2015, feces and nasal swabs from residents from LTCFs in Amsterdam, the Netherlands were collected and analyzed for presence of multidrug-resistant Gram-negative bacteria (MDRGN), including ESBL-E, carbapenemase-producing Enterobacteriaceae (CPE), colistin-resistant Enterobacteriaceae and methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Logistic regression analysis was performed to assess associations between variables and ESBL-carriage. RESULTS: In total, 385 residents from 12 LTCFs (range 15-48 residents per LTCF) were enrolled. The prevalence of carriage of MDRGN was 18.2% (range among LTCFs 0-47%) and the prevalence of ESBL-E alone was 14.5% (range among LTCFs: 0-34%). Of 63 MDRGN positive residents, 50 (79%) were ESBL-E positive of which 43 (86%) produced CTX-M. Among 44 residents with ESBL-E positive fecal samples of whom data on contact precautions were available at the time of sampling, only 9 (20%) were already known as ESBL-E carriers. The prevalence for carriage of MRSA was 0.8% (range per LTCF: 0-7%) and VRE 0%. One CPE colonized resident was found. All fecal samples tested negative for presence of plasmid mediated resistance for colistin (MCR-1). Typing of isolates by Amplified Fragment Length Polymorphism (AFLP) showed five MDRGN clusters, of which one was found in multiple LTCFs and four were found in single LTCFs, suggesting transmission within and between LTCFs. In multivariate analysis only the presence of MDRO in the preceding year remained a risk factor for ESBL-E carriage. CONCLUSIONS: The ESBL-carriage rate of residents in LTCFs is nearly two times higher than in the general population but varies considerably among LTCFs in Amsterdam, whereas carriage of MRSA and VRE is low. The majority (80%) of ESBL-E positive residents had not been detected by routine culture of clinical specimens at time of sampling. Current infection control practices in LTCFs in Amsterdam do not prevent transmission. Both improvement of basic hygiene, and funding for laboratory screening, should allow LTCFs in Amsterdam to develop standards of care to prevent transmission of ESBL-E.

Evaluation of an in vitro model with a novel statistical approach to measure differences in bacterial survival of extended-spectrum ß-lactamase-producing Escherichia coli on an inanimate surface.

Background: The role of environmental contamination in the transmission of Enterobacteriaceae is increasingly recognized. However, factors influencing the duration of survival in the environment have not yet been extensively studied. In this study, we developed and evaluated an in vitro model with a novel statistical approach to accurately measure differences in bacterial survival, that can be used to model the effects of multiple factors/conditions in future experiments. Methods: Two extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (E. coli) isolates were used for this in vitro experiment: a CTX-M-15-producing E. coli sequence type (ST) 131 and a CTX-M-1-producing E. coli ST10 isolate. Each strain was 1:1 diluted in sterile water, sterile saline or sheep blood. Cover glasses (18 × 18 mm) were inoculated with the dilution and subsequently kept at room temperature. Bacterial survival on the glasses was determined hourly during the first day, once daily during the following 6 days, and from day 7 on, once weekly up to 100 days. The experiment was repeated six times for each strain, per suspension fluid. Results: Viable bacteria could be detected up to 70 days. A biphasic survival curve for all suspension fluids was observed, whereby there was a rapid decrease in the number of viable bacteria in the first 7 h, followed by a much slower decrease in the subsequent days. Conclusions: We found a difference in survival probability between E. coli ST10 and ST131, with a higher proportion of viable bacteria remaining after 7 h for ST131, particularly in sheep blood.

Decreasing prevalence of contamination with extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) in retail chicken meat in the Netherlands.

Retail chicken meat is a potential source of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E). In the past decade, vast national efforts were undertaken to decrease the antibiotic use in the veterinary sector, resulting in a 58% decrease in antibiotic sales in the sector between 2009 and 2014. This decrease in antibiotic use was followed by a decrease in ESBL-E prevalence in broilers. The current study investigates the prevalence of contamination with ESBL-E in retail chicken meat purchased in the Netherlands between December 2013 and August 2015. It looks at associations between the prevalence of contamination with ESBL-E and sample characteristics such as method of farming (free-range or conventional), supermarket chain of purchase and year of purchase. In the current study, 352 chicken meat samples were investigated for the presence of ESBL-E using selective culture methods. Six samples were excluded due to missing isolates or problems obtaining a good quality sequence leaving 346 samples for further analyses. Of these 346 samples, 188 (54.3%) were positive for ESBL-E, yielding 216 ESBL-E isolates (Escherichia coli (n = 204), Klebsiella pneumoniae (n = 11) and Escherichia fergusonii (n = 1)). All ESBL-E isolates were analysed using whole-genome sequencing. The prevalence of contamination with ESBL-E in retail chicken meat decreased from 68.3% in 2014 to 44.6% in 2015, absolute risk difference 23.7% (95% confidence interval (CI): 12.6% - 34.1%). The ESBL-E prevalence was lower in free-range chicken meat (36.4%) compared with conventional chicken meat (61.5%), absolute risk difference 25.2% (95% CI: 12.9% - 36.5%). The prevalence of contamination with ESBL-E varied between supermarket chains, the highest prevalence of contamination was found in supermarket chain 4 (76.5%) and the lowest in supermarket chain 1 (37.8%). Pairwise isolate comparisons using whole-genome multilocus sequence typing (wgMLST) showed that clustering of isolates occurs more frequently within supermarket chains than between supermarket chains. In conclusion, the prevalence of contamination with ESBL-E in retail chicken in the Netherlands decreased over time; nevertheless, it remains substantial and as such a potential source for ESBL-E in humans.

Decline in AmpC ß-lactamase-producing Escherichia coli in a Dutch teaching hospital (2013-2016).

OBJECTIVE: The objective of this study is to determine the prevalence of rectal carriage of plasmid- and chromosome-encoded AmpC ß-lactamase-producing Escherichia coli and Klebsiella spp. in patients in a Dutch teaching hospital between 2013 and 2016. METHODS: Between 2013 and 2016, hospital-wide yearly prevalence surveys were performed to determine the prevalence of AmpC ß-lactamase-producing E. coli and Klebsiella spp. rectal carriage. Rectal swabs were taken and cultured using an enrichment broth and selective agar plates. All E. coli and Klebsiella spp. isolates were screened for production of AmpC ß-lactamase using phenotypic confirmation tests and for the presence of plasmid-encoded AmpC (pAmpC) genes. E. coli isolates were screened for chromosome-encoded AmpC (cAmpC) promoter/attenuator alterations. RESULTS: Fifty (2.4%) of 2,126 evaluable patients were identified as rectal carrier of AmpC ß-lactamase-producing E. coli. No carriage of AmpC ß-lactamase producing Klebsiella spp. was found. Nineteen (0.9%) patients harboured isolates with pAmpC genes and 30 (1,4%) patients harboured isolates with cAmpC promoter/attenuator alterations associated with AmpC ß-lactamase overproduction. For one isolate, no pAmpC genes or cAmpC promotor/attenuator alterations could be identified. During the study period, a statistically significant decline in the prevalence of rectal carriage with E. coli with cAmpC promotor/attenuator alterations was found (p = 0.012). The prevalence of pAmpC remained stable over the years. CONCLUSIONS: The prevalence of rectal carriage of AmpC-producing E. coli and Klebsiella spp. in patients in Dutch hospitals is low and a declining trend was observed for E. coli with cAmpC promotor/attenuator alterations.

Extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E) isolated from bean sprouts in the Netherlands.

Community-acquired carriage and infections due to extended-spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E) are increasing worldwide, resulting in increased morbidity, mortality and healthcare costs. The origins of community-acquired ESBL-E carriage and infections remain unclear. Bean sprouts are a potential source of Enterobacteriaceae for the community, as illustrated by outbreaks of pathogenic Enterobacteriaceae in the past. The current study focuses on contamination of retail bean sprouts with ESBL-E in the Netherlands. Of 131 bean sprout samples purchased between 2013 and 2016, 25 (19%) were contaminated with ESBL-E. The detected isolates were almost exclusively Klebsiella spp. and co-resistance to other antibiotics was observed frequently. Over time there was substantial genetic diversity between isolates. On the other hand, isolates from samples closely matched in time were frequently clonally related, indicative of batch contamination. Remarkably, no Escherichia coli was found. In conclusion, bean sprouts frequently harbor ESBL-E, which is a potential source for consumers.

The infection risk scan (IRIS): standardization and transparency in infection control and antimicrobial use.

Background: Infection control needs user-friendly standardized instruments to measure the compliance to guidelines and to implement targeted improvement actions. This abstract describes a tool to measure the quality of infection control and antimicrobial use, the Infection Risk Scan (IRIS). It has been applied in a hospital, several nursing homes and a rehabilitation clinic in the Netherlands. Method: The IRIS consists of a set of objective reproducible measurements, combining patient- and healthcare related variables, such as: hand hygiene compliance, environmental contamination using ATP measurements, prevalence of resistant microorganisms by active screening, availability of infection control preconditions, personal hygiene of healthcare workers, appropriate use of indwelling medical devices and appropriate use of antimicrobials. Results are visualized in a spider plot using traffic light colors to facilitate the interpretation. Results: The IRIS provided ward specific results within the hospital that were the basis for targeted improvement programs resulting in measurable improvements. Hand hygiene compliance increased from 43% to 66% (more than 1000 observations per IRIS, p < 0.000) and ATP levels were significantly reduced (p < 0.000). In the nursing homes, large differences were observed with environmental contamination as common denominator. Most remarkable were the difference in Extended Spectrum Beta-Lactamase Enterobacteriaceae (ESBL-E) prevalence (mean 11%, range 0-21%). Conclusion: The bundle approach and visualization of the IRIS makes it a useful infection prevention tool providing standardization and transparency. Targeted interventions can be started based on the results of the improvement plot and repeated IRIS can show the effect of interventions. In that way, a quality control cycle with continuous improvement can be achieved.

Proton Pump Inhibitor Use Is Associated With Extended-Spectrum ß-Lactamase-Producing Enterobacteriaceae Rectal Carriage at Hospital Admission: A Cross-Sectional Study.

In this cross-sectional study, 8.5% of patients using proton pump inhibitors (PPIs) were rectal carriers of extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E), compared with 2.9% of non-PPI users. In multivariable analysis, PPI use was independently associated with ESBL-E rectal carriage at hospital admission (adjusted odds ratio, 3.89; 95% confidence interval, 1.65 - 9.19).

Retrospective identification of a previously undetected clinical case of OXA-48-producing K. pneumoniae and E. coli: the importance of adequate detection guidelines.

INTRODUCTION: The laboratory detection of OXA-48-carbapenemase-producing Enterobacteriaceae is difficult, as minimum inhibition concentrations for carbapenems are often below the clinical breakpoint. In 2011, the Dutch national guideline for the detection of highly resistant micro-organisms was issued, which includes recommendations on the use of carbapenem screening breakpoints for the detection of carbapenemase-producing Enterobacteriaceae. MATERIALS AND METHODS: During a validation study of the Check-MDR CT103 microarray (Check-Points, Wageningen, The Netherlands) in 2013, an OXA-48-like carbapenemase gen was identified in two isolates that were previously obtained from a patient with non-Hodgkin lymphoma in 2007. Whole-genome sequencing (WGS) and subsequent BLAST Ringe Image Generator (BRIG) analysis were performed to establish the presence of OXA-48 carbapenemase encoding plasmids and their similarity. RESULTS: This case report describes the first documented OXA-48-producing Klebsiella pneumonia (ST648) and Escherichia coli (ST866) in the Netherlands. A similar IncL/M plasmid was identified in both strains, suggesting within-patient horizontal transfer. CONCLUSION: This case illustrates that OXA-48-carbapenemase-producing Enterobacteriaceae can be unnoticed without adequate laboratory detection procedures. Our observation stresses the importance of uniform and adequate laboratory methods for the timely and accurate detection of important antimicrobial resistance.

Trends in Extended Spectrum Beta-Lactamase (ESBL) Producing Enterobacteriaceae and ESBL Genes in a Dutch Teaching Hospital, Measured in 5 Yearly Point Prevalence Surveys (2010-2014).

This paper describes the trends in prevalence of ESBL producing Enterobacteriaceae (ESBL-E) and ESBL genes, measured in five consecutive yearly Point Prevalence Surveys (PPS). All patients present in the hospital and in a day-care clinic (including patients on dialysis) on the day of the survey, were screened for perianal ESBL-E carriage. Perianal swabs were taken and cultured using an enrichment broth and a selective agar plate. Both phenotypic and genotypic methods were used to detect the production of ESBL, presence of ESBL-genes and clonal relatedness. Out of 2,695 patients, 135 (5.0%) were tested ESBL-E positive. The overall ESBL-E prevalence was stable over the years. Overall 5.2% of all ESBL-E were acquired by nosocomial transmission. A relative decrease of CTX-M-1-1-like ESBL genes (from 44 to 25%, p = 0.026) was observed, possibly related to the strong (>60%) decrease in antibiotic use in livestock in our country during the same period.

Extensive dissemination of extended spectrum ß-lactamase-producing Enterobacteriaceae in a Dutch nursing home.

OBJECTIVE: Risk factors for rectal carriage of ESBL-E and transmission were investigated in an outbreak of extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E). DESIGN: Rectal carriage of ESBL-E was determined in a cross-sectional survey by culture of perianal swabs or fecal samples. Both phenotypical and genotypical methods were used to detect the production of ESBL. Nosocomial transmission was defined as the presence of genotypically related strains in ≥2 residents within the NH. Patient characteristics and variables in infection control practices were registered to investigate risk factors for transmission. SETTING: A nursing home (NH) in the southern Netherlands. PARTICIPANTS: Of 189 residents, 160 residents (84.7%) were screened for ESBL-E carriage. Of these 160 residents, 33 (20.6%) were ESBL-E positive. ESBL carriage rates varied substantially between wards (range, 0-47%). Four different ESBL-E clusters were observed. A bla CTX-M1-15 positive E. coli ST131 constituted the largest cluster (n=21) and was found in multiple wards (n=7). RESULTS: Our investigation revealed extensive clonal dissemination of bla CTX-M1-15-positive E. coli ST131 in a nursing home. Unexplained differences in ESBL prevalence were detected among the wards. CONCLUSIONS: As NHs constitute potential sources of multidrug-resistant bacteria, it is important to gain a better understanding of the risks factors and routes of transmission of ESBL-E.

Measuring the quality of infection control in Dutch nursing homes using a standardized method; the Infection prevention RIsk Scan (IRIS).

BACKGROUND: We developed a standardised method to assess the quality of infection control in Dutch Nursing Home (NH), based on a cross-sectional survey that visualises the results. The method was called the Infection control RIsk Infection Scan (IRIS). We tested the applicability of this new tool in a multicentre surveillance executed June and July 2012. METHODS: The IRIS includes two patient outcome-variables, i.e. the prevalence of healthcare associated infections (HAI) and rectal carriage of Extended-Spectrum Beta-Lactamase (ESBL) producing Enterobacteriaceae (ESBL-E); two patient-related risk factors, i.e. use of medical devices, and antimicrobial therapy; and three ward-related risk factors, i.e. environmental contamination, availability of local guidelines, and shortcomings in infection prevention preconditions. Results were categorised as low-, intermediate- and high risk, presented in an easy-to-read graphic risk spider-plot. This plot was given as feedback to management and healthcare workers of the NH. RESULTS: Large differences were found among most the variables in the different NH. Common shortcomings were the availability of infection control guidelines and the level of environmental cleaning. Most striking differences were observed in the prevalence of ESBL carriage, ranged from zero to 20.6% (p < 0.001). CONCLUSIONS: The IRIS provided a rapid and easy to understand assessment of the infection control situation of the participating NH. The results can be used to improve the quality of infection control based on the specific needs of a NH but needs further validation in future studies. Repeated measurement can determine the effectiveness of the interventions. This makes the IRIS a useful tool for quality systems.

Detection and occurrence of plasmid-mediated AmpC in highly resistant gram-negative rods.

OBJECTIVES: The aim of this study was to compare the current screening methods and to evaluate confirmation tests for phenotypic plasmidal AmpC (pAmpC) detection. METHODS: For this evaluation we used 503 Enterobacteriaceae from 18 Dutch hospitals and 21 isolates previously confirmed to be pAmpC positive. All isolates were divided into three groups: isolates with 1) reduced susceptibility to ceftazidime and/or cefotaxime; 2) reduced susceptibility to cefoxitin; 3) reduced susceptibility to ceftazidime and/or cefotaxime combined with reduced susceptibility to cefoxitin. Two disk-based tests, with cloxacillin or boronic acid as inhibitor, and Etest with cefotetan-cefotetan/cloxacillin were used for phenotypic AmpC confirmation. Finally, presence of pAmpC genes was tested by multiplex and singleplex PCR. RESULTS: We identified 13 pAmpC producing Enterobacteriaceae isolates among the 503 isolates (2.6%): 9 CMY-2, 3 DHA-1 and 1 ACC-1 type in E. coli isolates. The sensitivity and specificity of reduced susceptibility to ceftazidime and/or cefotaxime in combination with cefoxitin was 97% (33/34) and 90% (289/322) respectively. The disk-based test with cloxacillin showed the best performance as phenotypic confirmation method for AmpC production. CONCLUSIONS: For routine phenotypic detection of pAmpC the screening for reduced susceptibility to third generation cephalosporins combined with reduced susceptibility to cefoxitin is recommended. Confirmation via a combination disk diffusion test using cloxacillin is the best phenotypic option. The prevalence found is worrisome, since, due to their plasmidal location, pAmpC genes may spread further and increase in prevalence.

Evaluation of a commercial real-time PCR for the detection of extended spectrum ß-lactamase genes.

We investigated the performance of a real-time PCR for the detection of extended spectrum ß-lactamase genes in Enterobacteriaceae (Check-MDR ESBL PCR). Results from micro-arrays were considered as the gold standard. An analysis on 489 isolates resulted in a sensitivity of 98.9 % and a specificity of 100 % for the PCR.

Extended-spectrum ß-lactamase-producing Escherichia coli from retail chicken meat and humans: comparison of strains, plasmids, resistance genes, and virulence factors.

BACKGROUND: The worldwide prevalence of extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae is increasing rapidly both in hospitals and in the community. A connection between ESBL-producing bacteria in food animals, retail meat, and humans has been suggested. We previously reported on the genetic composition of a collection of ESBL-producing Escherichia coli (ESBL-EC) from chicken meat and humans from a restricted geographic area. Now, we have extended the analysis with plasmid replicons, virulence factors, and highly discriminatory genomic profiling methods. METHODS: One hundred forty-five ESBL-EC isolates from retail chicken meat, human rectal carriers, and blood cultures were analyzed using multilocus sequence typing, phylotyping, ESBL genes, plasmid replicons, virulence genes, amplified fragment length polymorphism (AFLP), and pulsed-field gel electrophoresis (PFGE). RESULTS: Three source groups overlapped substantially when their genetic composition was compared. A combined analysis using all variables yielded the highest resolution (Wilks lambda [Λ]: 0.08). Still, a prediction model based on the combined data classified 40% of the human isolates as chicken meat isolates. AFLP and PFGE showed that the isolates from humans and chicken meat could not be segregated and identified 1 perfect match between humans and chicken meat. CONCLUSIONS: We found significant genetic similarities among ESBL-EC isolates from chicken meat and humans according to mobile resistance elements, virulence genes, and genomic backbone. Therefore, chicken meat is a likely contributor to the recent emergence of ESBL-EC in human infections in the study region. This raises serious food safety questions regarding the abundant presence of ESBL-EC in chicken meat.