Study finds no link between US antibiotic prescribing, resistant gonorrhea
Although overuse of antimicrobials is a known contributor to antimicrobial resistance in general, researchers reported yesterday they could find no association between numbers of US antimicrobial prescriptions during a recent 8-year period and resistance in the bacteria that causes gonorrhea.
The researchers, from the Centers for Disease Control and Prevention (CDC) and several other institutions, note that Neisseria gonorrhoeae has developed resistance to every antimicrobial prescribed for it over the years and has been declared an urgent resistance threat by the CDC.
Writing in Emerging Infectious Diseases, the team said it is unclear to what extent antimicrobial use contributes to the emergence of gonococcal resistance in the United States.
To investigate the question, they gathered county-level antimicrobial susceptibility data from the CDC's Gonococcal Isolate Surveillance Project (GISP), county-level antimicrobial consumption data from the private company IMS Health, and demographic data from the US Census Bureau. The study covered the years 2005 to 2013.
The research included susceptibility test results for 43,852 N gonorrhoaea isolates taken from men treated for gonococcal urethritis at clinics for sexually transmitted infections. The isolates were tested against azithromycin, ceftriaxone, ciprofloxacin, penicillin, spectinomycin, and tetracycline. The IMS Health data covered more than 70% of all outpatient prescriptions during the study period.
Using multivariable statistical models, the team found no associations between N gonorrhoeae susceptibility and the numbers of prescriptions of any of the studied drugs.
Writing on what might explain the results, the authors speculated that factors other than population-level prescribing rates, such as importation of resistant strains, might contribute to gonococcal resistance. Or, they said, their data sources or methods might not have been sensitive enough to detect a relationship between prescribing and resistance.
The findings "suggest that population-wide domestic antimicrobial drug prescribing rates might not play a prominent role in the emergence of gonococcal resistance in the United States," they conclude. "Other means, such as importation from other countries, might play larger roles. Through this lens, enhanced surveillance for and public health capacity to respond to imported resistant strains are important strategies."
Sep 12 Emerg Infect Dis report
High levels of resistant bacteria found in Tanzanian street children
A study yesterday in PLoS One found a high incidence of fecal carriage of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae among street children in Mwanza city, Tanzania, a port city of almost 3 million people.
The researchers analyzed stool samples obtained from 107 street children in 2015 and found ESBL-producing Enterobacteriaceae (EPE) in 34 of them (32%). Out of 36 isolates from the 34 children, 36 (100%), 35 (97%), 25 (69%), and 16 (44%) were resistant to tetracycline, trimethoprim-sulfamethoxazole, ciprofloxacin, and gentamicin, respectively.
The CTX-M-15 ESBL gene was detected in 27 isolates, or 75%. About 83% of the resistant pathogens were Escherichia coli.
The authors say their study "highlights the need for multidisciplinary approaches to understand the epidemiology and drivers of antimicrobial resistance in low-income countries."
Sep 12 PLoS One study