Date Sent: 06/13/2016 02:31 PM EDT
Sender: Michigan Health Alert Network
Subject: Alert to U.S. Healthcare Facilities: First mcr-1 Gene in E. coli Bacteria found in a Human in the United States
CDC HEALTH ADVISORY
Alert to U.S. Healthcare Facilities: First mcr-1 Gene in E. coli Bacteria found in a Human in the United States
The Centers for Disease Control and Prevention (CDC) is collaborating in a coordinated public health response to the Department of Defense (DoD) announcement on May 26 of the first mcr-1 genefound in bacteria from a human in the United States(http://aac.asm.org/content/early/2016/05/25/AAC.01103-16.full.pdf+html). Escherichia coli (E. coli) bacteria carrying the mcr-1 gene were found in a urine sample from a person in Pennsylvania with no recent travel outside of the United States who presented to a clinic with a urinary tract infection. The mcr-1 gene makes bacteria resistant to the antibiotic colistin, which is used as a last-resort drug to treat patients with infections caused by multidrug-resistant bacteria, including carbapenem-resistant Enterobacteriaceae (CRE). The mcr-1 gene exists on a plasmid, a small piece of DNA that is capable of moving from one bacterium to another, potentially spreading antibiotic resistance to other bacterial species. CDC is issuing this HAN notice as a reminder to U.S. healthcare facilities about recommendations to prevent antibiotic resistant infections and alert them to additional recommendations for detecting and reporting bacteria with the mcr-1 gene.
In November 2015, a report from China first described plasmid-mediated colistin-resistance caused by the mcr-1 gene. Following that report, retrospective investigations of historical isolates from outside the United States have identified the rare occurrence of mcr-1 in Enterobacteriaceae from the 1980s. Bacteria with this resistance mechanism have now been identified from humans, food, environmental samples, and food animals in at least 20 countries around the world. Most reports to date have identified the mcr-1 gene in E. coli, but it has also been reported from Salmonella species,Shigella sonnei, and Klebsiella pneumoniae.
Three mcr-1 producing E. coli have been identified in the United States as of June 7, 2016: one in a clinical specimen from a person in Pennsylvania and two from intestinal samples from pigs. The E. coli isolate from the patient was also resistant to antibiotics in at least five additional antibiotic classes, including cephalosporins, fluoroquinolones, sulfonamides, aminoglycosides, and tetracyclines. The sample from one pig also was resistant to other antibiotics, including ampicillin, streptomycin, sulfisoxazole, and tetracycline. No additional resistance was found in the isolate from the second pig. The presence of the mcr-1 gene on a plasmid means that colistin resistance can be shared with other more resistant bacteria such as CRE, raising the possibility that untreatable bacteria could develop. A rapid public health response is underway to identify and contain any potential spread from the patient. CDC laboratories have developed protocols for testing microorganisms for the mcr-1 gene and are performing screening tests to see if people in contact with the patient with mcr-1 might be colonized with this organism. CDC is increasing its surveillance of human samples from U.S. healthcare settings. CDC’s National Antimicrobial Resistance Monitoring System, in collaboration with the Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA), will continue to look for mcr-1mediated colistin resistance in enteric bacteria from humans, retail meat, and food animals.
Given the discovery of mcr-1 in a person in Pennsylvania, CDC reiterates the importance of measures to prevent transmission of antibiotic resistant bacteria, including those resistant to colistin or carrying the mcr-1 gene. CDC recommends the following: