Tuesday, June 14, 2016

CDC HAN: Alerting Healthcare Facilities Of 1st MCR-1 Gene Detection In US Patient


Late last month in MHRP: 1st Detection Of Colistin Resistant E. coli in U.S. Resident, we looked at a worrying report that the recently discovered MCR-1 gene - which conveys resistance to the last resort antibiotic Colistin - had been detected in a E. coli sample collected from a patient in Pennsylvania.

It was only November of last year  when we saw the first report of this gene's detection in China (see my initial report Return Of The Plasmids).

Since then we've seen a steady stream of reports finding this gene is already well distributed round the globe (see The Lancet: Dissemination Of The MCR-1 Colistin Resistance Gene and Eurosurveillance Editorial: Plasmid-Mediated Colistin Resistance (MCR-1 gene):The Story Unfolds).

Of particular concern, in The Lancet's Emergence of the mcr-1 colistin resistance gene in carbapenem-resistant Enterobacteriaceae, we saw a report on two K pneumoniae isolates that carried the MCR-1 gene and the gene for NDM-5 (Carbapenem-resistance), providing it near pandrug resistance.

Since this gene can be carried, and transferred to other bacteria via plasmids (see Study: Adaptation Of Plasmids To New Bacterial Species), the expectation is this resistance gene (like NDM-1) can spread laterally to other bacteria.

While the sample collected from the Pennsylvania patient was still sensitive to other antibiotics, in yesterdays' CDC HAN we learn that two other US samples - taken from swine - were also positive for the MCR-1 gene, and one of those was also resistant to a number of (but not all) common antibiotics. 

HAN messages (Alert, Advisory, Update, or Info) are designed to ensure that communities, agencies, health care professionals, and the general public are able to receive timely information on important public health issues.

An `Advisory’ is a second tier message that Provides important information for a specific incident or situation, but may not require immediate action.

Due to its length, I've only posted some excerpts.  Follow the link below to read this HAN Advisory in its entirety.

Alert to U.S. Healthcare Facilities: First mcr-1 Gene in E. coli Bacteria found in a Human in the United States

Distributed via the CDC Health Alert Network
June 13, 2016, 13:35 EDT (1:35 PM EDT)


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 gene found in bacteria from a human in the United States
Escherichia coli
E. coli
) bacteria carrying the
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).
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


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:
  • Infection Prevention: Healthcare providers should follow Standard and Contact Precautions (http://www.cdc.gov/hicpac/2007IP/2007ip_part3.html) for any patients colonized or infected with antibiotic resistant bacteria, including patients who are found to have mcr-1 mediated resistant organisms. Healthcare facilities should follow manufacturers’ instructions for device cleaning and reprocessing.
  • Laboratory Testing: If laboratories are testing to determine whether colistin can be used clinically, Enterobacteriaceae isolates with a minimum inhibitory concentration (MIC) to colistin of 4 µg/ml or higher should be tested for confirmation and the presence of mcr-1. Thus far, all microorganisms that have contained the mcr-1 gene can safely be tested in a biosafety level-2 (BSL-2) laboratory. Isolates should be sent to CDC for confirmatory testing via the state or local public health department, per the CDC test directory (http://www.cdc.gov/laboratory/specimen-submission/detail.html?CDCTestCode=CDC-10223), if local testing is not available. The results and test method that were used for initial colistin testing should be included with any isolates submitted for confirmatory testing. CDC laboratories are in the process of validating a rapid polymerase chain reaction (PCR) test to detect mcr-1 in bacteria with elevated colistin MICs. It is not necessary to test Enterobacteriaceae with intrinsic colisitin resistance (e.g., Proteus, Providencia, Morganella, and Serratia species).  Additionally, since Enterobacter species often have MICs of >=2 mcg/ml to colisitin, they should be sent for mcr-1 testing only if other risk factors exist, such as a recent history of travel outside the United States to a country where mcr-1 has been found to be more common (http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=21403).
  • Validation of Laboratory Testing: CDC is making test-bacteria with elevated colistin MICs, available to laboratories, researchers, and others through the FDA-CDC Antimicrobial Resistance Bacteria Isolate Bank (http://www.cdc.gov/drugresistance/resistance-bank/) for use in validation of colistin-resistance testing in U.S. clinical laboratories.
  • Environmental Cleaning: Healthcare facilities should ensure rooms where patients with antibiotic-resistant infections have been placed receive thorough daily and terminal cleaning.
  • Reporting to Public Health: Healthcare facilities and laboratories should adhere to local reporting requirements for all antibiotic resistant infections. If Enterobacteriaceae with mcr-1 are identified from patients, healthcare facilities and laboratories should notify local or state public health authorities as quickly as possible, and inform clinicians caring for the patient and responsible infection prevention staff.
  • Preparing food safely: Cook all meat, poultry, and fish to its proper internal temperature to kill bacteria (http://www.foodsafety.gov/keep/charts/mintemp.html), viruses, and other foodborne pathogens, regardless of antibiotic resistance. 
(Continue . . . )