Antibiotic-resistant strain of E. coli increasing among older adults and residents of nursing homes

March 12, 2013

Antibiotic-resistant Escherichia coli (E. coli) continues to proliferate, driven largely by expansion of a strain of E. coli know as sequence type ST131. A new study points to hospitals and long-term care facilities (LTCF) as settings in which this antibiotic-resistant strain is increasingly found. The study is published in the April issue of Infection Control and Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America.

E. coli is the most common gram-negative pathogen, causing both and extraintestinal infections such as pneumonia, meningitis, and bloodstream, urinary tract, abdominal, and . Strains of E. coli that are resistant to single or multiple classes of antibiotics are becoming more prevalent. E. coli ST131 is commonly associated with fluoroquinolone resistance.

"The expansion of E. coli strain ST131 is recognized as a pandemic, but has received comparatively little attention in the United States," said Ritu Banerjee, lead investigator of the study. "Alarmingly, the pace of new antibiotic development has not kept up with the emergence of antibiotic-resistant E. coli, making development of strategies to halt further emergence and spread of these strains a public health priority."

In this , investigators evaluated nearly 300 consecutive patients in Olmsted County, Minnesota with extraintestinal E. coli infections and found ST131 to be a dominant, antimicrobial-resistant clonal group associated with older age, long-term care facility residence, complicated infections, history of urinary tract infection, and prior antimicrobial use.

LTCF residence was the strongest predictor of ST131 infection, with LTCF residents having 8 times the risk of contracting E. coli ST131 compared with non-LTCF residents. This trend coincides with the increasing prevalence of ST131 among patients 65 years and older. It is likely that extensive antibiotic exposure, close contact with other antibiotic-exposed individuals, age and health-associated alterations in intestinal microbiota all contribute to the high prevalence of ST131 among the elderly population.

Patients with ST131 isolates were often treated with ineffective antibiotics at first and as a result they had recurrent or persistent symptoms. In the cohort, ST131 isolates were also more than twice as likely to be healthcare-associated infections as compared to community-associated infections.

"The finding that clonal expansion of ST131 is occurring primarily in healthcare and long-term care facilities indicates an urgent need for improved antibiotic use and infection control practices within such institutions, both to reduce selection for ST131 and to block further transmission. Efforts that focus on reducing overuse and misuse of fluoroquinolones are likely to have the greatest impact on ST131 prevalence, given the strong association between ST131 and fluoroquinolone resistance," said Banerjee.

Explore further: Roads pave the way for the spread of superbugs

More information: Ritu Banerjee, Brian Johnston, Christine Lohse, Stephen B.Porter, Connie Clabots and James R. Johnson. "Escherichia coli Sequence Type 131 Is a Dominant, Antimicrobial-Resistant Clonal Group Associated with Healthcare and Elderly Hosts." Infection Control and Hospital Epidemiology 34:4 (April 2013).

Related Stories

Roads pave the way for the spread of superbugs

September 29, 2011
Antibiotic resistant E. coli was much more prevalent in villages situated along roads than in rural villages located away from roads, which suggests that roads play a major role in the spread or containment of antibiotic ...

Unnecessary antimicrobial use increases risk of recurrent infectious diarrhea

January 9, 2013
The impact of antibiotic misuse has far-reaching consequences in healthcare, including reduced efficacy of the drugs, increased prevalence of drug-resistant organisms, and increased risk of deadly infections. A new study ...

Recommended for you

Novel approach to track HIV infection

August 18, 2017
Northwestern Medicine scientists have developed a novel method of tracking HIV infection, allowing the behavior of individual virions—infectious particles—to be connected to infectivity.

Faulty gene linked to obesity in adults

August 18, 2017
Groundbreaking new research linking obesity and metabolic dysfunction to a problem in the energy generators in cells has been published by researchers from the Harry Perkins Institute of Medical Research and The University ...

Two lung diseases killed 3.6 million in 2015: study

August 17, 2017
The two most common chronic lung diseases claimed 3.6 million lives worldwide in 2015, according to a tally published Thursday in The Lancet Respiratory Medicine.

New test differentiates between Lyme disease, similar illness

August 16, 2017
Lyme disease is the most commonly reported vector-borne illness in the United States. But it can be confused with similar conditions, including Southern Tick-Associated Rash Illness. A team of researchers led by Colorado ...

Addressing superbug resistance with phage therapy

August 16, 2017
International research involving a Monash biologist shows that bacteriophage therapy – a process whereby bacterial viruses attack and destroy specific strains of bacteria - can be used successfully to treat systemic, multidrug ...

Can previous exposure to west Nile alter the course of Zika?

August 15, 2017
West Nile virus is no stranger to the U.S.-Mexico border; thousands of people in the region have contracted the mosquito-borne virus in the past. But could this previous exposure affect how intensely Zika sickens someone ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.