BACKGROUNDWe identified an outbreak of AmpC–producingEscherichia coliinfections resistant to third-generation cephalosporins and carbapenems (CR) among 7 patients who had undergone endoscopic retrograde cholangiopancreatography at hospital A during November 2012–August 2013. Gene sequencing revealed a shared novel mutation in ablaCMYgene and a distinctivefumC/ fimHtyping profile.OBJECTIVETo determine the extent and epidemiologic characteristics of the outbreak, identify potential sources of transmission, design and implement infection control measures, and determine the association between the CRE. coliand AmpCE. colicirculating at hospital A.METHODSWe reviewed laboratory, medical, and endoscopy reports, and endoscope reprocessing procedures. We obtained cultures from endoscopes after reprocessing as well as environmental samples and conducted pulsed-field gel electrophoresis and gene sequencing on phenotypic AmpC isolates from patients and endoscopes. Cases were those infected with phenotypic AmpC isolates (both carbapenem-susceptible and CR) and identicalblaCMY-2,fumC, andfimHalleles or related pulsed-field gel electrophoresis patterns.RESULTSThirty-five of 49 AmpCE. colitested met the case definition, including all CR isolates. All cases had complicated biliary disease and had undergone at least 1 endoscopic retrograde cholangiopancreatography at hospital A. Mortality at 30 days was 16% for all patients and 56% for CR patients. Two of 8 reprocessed endoscopic retrograde cholangiopancreatography scopes harbored AmpC that matched case isolates by pulsed-field gel electrophoresis. Environmental cultures were negative. No breaches in infection control were identified. Endoscopic reprocessing exceeded manufacturer’s recommended cleaning guidelines.CONCLUSIONRecommended reprocessing guidelines are not sufficient.Infect Control Hosp Epidemiol2015;00(0): 1–9

Culture confirmation of Shiga toxin-producing Escherichia coli (STEC) is very important for epidemiologic analysis. However, isolation of non-O157 STEC on conventional selective media such as sorbitol-MacConkey agar (SMAC) can be difficult because of heavy growth of competing bacteria and its phenotypical similarity to commensal nonpathogenic E. coli. An acid enrichment procedure was introduced in this study to facilitate detection of STEC from patients who were symptomatic. Forty-seven clinical fecal broths, which tested positive for Shiga toxin by commercial immunoassay, were processed for the isolation of STEC by both conventional and the acid enrichment methods. The acid enrichment method and conventional culture recovered STEC from 91% (43/47) and 70% (33/47) of the fecal broths, respectively. Neither method retrieved STEC in 3 specimens. Thirty-six STEC were successfully serogrouped, which included O26 (n = 11), O157 (n = 9), O103 (n = 7), O121 (n = 3), O111 (n = 2 each), O28AC, O146, O76, and O undetermined (n = 1 each). The analysis of STEC isolates by realtime PCR indicated that all 9 E. coli O157 contained stx2 gene alone or in combination with stx1. Non-O157 STEC more frequently contained stx1 only, and about one-third possessed stx2. The novel acid enrichment protocol greatly reduced the growth of competitor colonies on RTN and TCSMAC. The study demonstrated that incorporation of an acid enrichment procedure in clinical testing improved the isolation of STEC in fecal specimens. Published by Elsevier Inc.

The Washington State Department of Health Public Health Laboratories (WAPHL) has tested 11,501 samples between 2007 and 2017 for a foodborne disease using a combination of identification, serotyping, and subtyping tools. During this period there were 8037 total clinical and environmental samples tested by pulsed-field gel electrophoresis (PFGE), including 512 foodborne disease clusters and 2176 PFGE patterns of Salmonella enterica subsp. enterica . There were 2446 Shiga toxin–producing Escherichia coli samples tested by PFGE, which included 158 foodborne disease clusters and 1174 PFGE patterns. There were 332 samples of Listeria monocytogenes tested by PFGE, including 35 foodborne disease clusters and 104 PFGE patterns. Sources linked to outbreaks included raw chicken, unpasteurized dairy products, various produce types, and undercooked beef among others. As next-generation sequencing (NGS) replaces PFGE, the impact of this transition is expected to be significant given the enhanced cluster detection power NGS brings. The measures presented here will be a reference baseline in future years.