The U.S. military has seen steady increases in multidrug-resistant (MDR) gram-negative bacteria (GNB) infections in casualties from Iraq and Afghanistan. Vento, et al. (2013) evaluated the prevalence of MDR GNB colonization in U.S. military personnel.
GNB colonization surveillance of healthy, asymptomatic military personnel (101 in the U.S. and 100 in Afghanistan) was performed by swabbing seven anatomical sites. U.S.-based personnel had received no antibiotics within 30 days of specimen collection, and Afghanistan-based personnel were receiving doxycycline for malaria chemoprophylaxis at time of specimen collection. Isolates underwent genotypic and phenotypic characterization.
The only colonizing MDR GNB recovered in both populations was Escherichia coli (p=0.01), which was seen in 2 percent of US-based personnel (all perirectal) and 11 percent of Afghanistan-based personnel (10 perirectal, 1 foot+groin). Individuals with higher off-base exposures in Afghanistan did not show a difference in overall GNB colonization or MDR E. coli colonization, compared with those with limited off-base exposures.
The researchers conclude that healthy U.S.- and Afghanistan-based military personnel have community onset-MDR E. coli colonization, with Afghanistan-based personnel showing a 5.5-fold higher prevalence. The association of doxycycline prophylaxis or other exposures with antimicrobial resistance and increased rates of MDR E. coli colonization needs further evaluation. Their research was published in BMC Infectious Diseases.
Reference: Vento TJ, Cole DW, et al. Multidrug-resistant gram-negative bacteria colonization of healthy US military personnel in the US and Afghanistan. BMC Infectious Diseases 2013, 13:68 doi:10.1186/1471-2334-13-68