Antimicrobial resistance in eight US hospitals along the US-Mexico border, 2000-2006

Antimicrobial resistance (AR) is a growing problem worldwide and international travel, cross-border migration, and antimicrobial use may contribute to the introduction or emergence of AR. We examined AR rates and trends along the US-Mexico border by analysing microbiology data from eight US hospitals in three states bordering Mexico. Microbiology data were ascertained for the years 2000-2006 and for select healthcare and community pathogens including, three Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) and three Gram-positive (Staphylococcus aureus, Enterococcus, Streptococcus pneumoniae) pathogens and 10 antimicrobial-pathogen combinations. Resistance was highest in S. aureus (oxacillin resistance 45·7%), P. aeruginosa (quinolone resistance 22·3%), and E. coli (quinolone resistance 15·6%); six (60%) of the 10 antimicrobial-pathogen combinations studied had a significantly increasing trend in resistance over the study period. Potential contributing factors in the hospital and community such as infection control practices and antimicrobial use (prescription and non-prescription) should be explored further in the US-Mexico border region.