MINNEAPOLIS—The pandemic strain of drug-resistant E. coli H30 begins as a subtle, hard-to-detect infection, usually of the urinary tract. The strain is of special concern, however, according to a report in Clinical Infectious Diseases, because it appears to have an intrinsic ability to cause persistent, harmful and, sometimes, deadly infections.1

Minneapolis VA Health Care System-led researchers pointed out that no other type of E. coli causes as much widespread damage worldwide because H30 can go unnoticed at first.

A particular genetic family of E. coli, Sequence Type 131, produced the H30 strain, which appeared during the late 1990s. It quickly expanded around the world to become the dominant drug-resistant strain in virtually all populations.

“No other type of E. coli is causing this much widespread damage,” said co-author Evgeni Sokurenko of the University of Washington in Seattle. “We need to pay as much attention to it as we do to the superbug MRSA, the treatment-resistant staph infection.”

Each year in the United States alone, H30 may cause more than 1 million urinary tract infections, as well as much more lethal blood infections, according to background information in the report.

For the study, researchers explored possible associations of H30 with patient characteristics, clinical manifestations, treatment and how well or poorly the patients fared. Results indicated that researchers found that individuals at greatest risk for E. coli H30 infection tended to be older women and men who had been in a healthcare facility, including long-term care residences or hospitals, who had received antibiotics and who had underlying conditions that weakened their ability to ward off infections.

Yet, at their first clinical visit, those patients were significantly less likely to be suspected of having an infection and less likely to receive a proper antibiotic prescription, according to the study, leading to a severe complication.

The researchers reported that H30 “was strongly associated with ineffective initial antimicrobial therapy, clinical and microbial persistence, and diverse, later-occurring adverse effects.”

“H30 might have that dangerous combination of being both highly resistant to antibiotics and highly successful as a stealth pathogen,” Sokurenko added. “This double-trouble may be why H30 is so widespread and has become a superbug. What makes it worse is that can go unnoticed in a patient until it causes significant damage.”

1 Johnson JR, Thuras P, Johnston BD, Weissman SJ, et. al. The Pandemic H30 Subclone of Escherichia coli Sequence Type 131 Is Associated With Persistent Infections and Adverse Outcomes Independent From Its Multidrug Resistance and Associations With Compromised Hosts. Clin Infect Dis. 2016 Jun 15;62(12):1529-36. doi: 10.1093/cid/ciw193. Epub 2016 Mar 29. PubMed PMID: 27025834; PubMed Central PMCID: PMC4885656.