Identification of four patients with colistin-resistant Escherichia coli containing the mobile colistin resistance mcr-1 gene from a single health system in Michigan.

Clinical Enterobacteriacae isolates with a colistin minimum inhibitory concentration (MIC) ≥4 mg/L from a United States hospital were screened for the mcr-1 gene using real-time polymerase chain reaction (RT-PCR) and confirmed by whole-genome sequencing. Four colistin-resistant Escherichia coli isolates contained mcr-1. Two isolates belonged to the same sequence type (ST-632). All subjects had prior international travel and antimicrobial exposure.

Statewide surveillance of carbapenem-resistant enterobacteriaceae in Michigan.

BACKGROUND: Carbapenem-resistant Enterobacteriaceae (CRE) are clinically challenging, threaten patient safety, and represent an emerging public health issue. CRE reporting is not mandated in Michigan. METHODS: The Michigan Department of Community Health-led CRE Surveillance and Prevention Initiative enrolled 21 facilities (17 acute care and 4 long-term acute care facilities) across the state. Baseline data collection began September 1, 2012, and ended February 28, 2013 (duration, 6 months). Enrolled facilities voluntarily reported cases of Klebsiella pneumoniae and Escherichia coli according to the surveillance algorithm. Patient demographic characteristics, laboratory testing, microbiology, clinical, and antimicrobial information were captured via standardized data collection forms. Facilities reported admissions and patient-days each month. RESULTS: One-hundred two cases over 957,220 patient-days were reported, resulting in a crude incidence rate of 1.07 cases per 10,000 patient-days. Eighty-nine case patients had test results positive for K. pneumoniae, whereas 13 had results positive for E. coli. CRE case patients had a mean age of 63 years, and 51% were male. Urine cultures (61%) were the most frequently reported specimen source. Thirty-five percent of cases were hospital onset; sixty-five percent were community onset (CO), although 75% of CO case patients reported healthcare exposure within the previous 90 days. Cardiovascular disease, renal failure, and diabetes mellitus were the most frequently reported comorbid conditions. Common ris k factors included surgery within the previous 90 days, recent infection or colonization with a multidrug-resistant organism, and recent exposures to antimicrobials, especially third- or fourth-generation cephalosporins. CONCLUSIONS: CRE are found throughout Michigan healthcare facilities. Implementing a regional, coordinated surveillance and prevention initiative may prevent CRE from becoming hyperendemic in Michigan.

Use of traceback methods to confirm the source of a multistate Escherichia coli O157:H7 outbreak due to in-shell hazelnuts.

Traceback methods by state regulatory agencies were used to complement traditional epidemiological cluster investigation methods and confirmed hazelnuts (also referred to as filberts) as the vehicle in a multistate outbreak of Escherichia coli O157:H7 infections. Bulk in-shell hazelnut and mixed-nut purchase locations were identified during the initial epidemiological interviews. Based on purchase dates and case onset dates, regulators in Minnesota, Michigan, and Wisconsin traced product back through the supply chain. Six (86%) retail locations received the suspect hazelnut or mixed-nut shipments from a Minnesota distributor, with one retailer (14%) receiving products from a Wisconsin distributor. Both distributors received 100% of their bulk in-shell hazelnuts and mixed nuts from a distributor in California. The California distributor received 99% of their hazelnuts from a packing company in Oregon. The California distributor received the hazelnuts in 50-lb (22.7-kg) bags and either resold them without opening the bags or used the in-shell hazelnuts in the manufacture of their in-shell mixed nuts. Records at the packing company in Oregon were incomplete or lacked sufficient detail needed to identify a suspect farm or group of suspect farms. Laboratory samples collected from human cases and subsequently recalled product matched the outbreak pulsed-field gel electrophoresis subtype of E. coli O157:H7. Hazelnut harvesting practices create a plausible route of contamination from fecal matter from domestic ruminants or wild deer. This outbreak investigation demonstrates the use of product traceback data to rapidly test an epidemiological hypothesis.