Comparative Sensitivity Testing Of Escherichia Coli And Pseudomonas Aeruginosa Isolates From El Paso, Texas, USA And Ciudad Juarez, Mexico.

Background: The U.S./Mexico border is more than 2,000 miles long and stretches 62.5 miles wide on each side. With more than 2 million residents, El Paso, Texas and Ciudad Juarez, Mexico comprise the largest U.S-Mexico border population. Every month, more than 4 million Americans and Mexicans cross the border to work, shop, visit, and seek medical care. It is hypothesized that factors stemming from uncontrolled and easy access to antibiotics in Ciudad Juarez, together with the enormous flow of traffic across the border, make this a prime area for the development of bacterial resistance.Objective: To compare the bacterial sensitivity patterns of Escherichia coli and Pseudomonas aeruginosa isolates from two U.S.-Mexico border cities.Methods: Isolates were collected from patients seen and treated at two hospitals in El Paso and two in Ciudad Juarez. The organisms were tested at a reference laboratory in El Paso according to NCCLS standards. Statistical analyses were performed using SAS to compare proportions of susceptible organisms between El Paso and Juarez.Results: A total of 364 Escherichia coli and 285 Pseudomonas aeruginosa isolates were identified and tested. Escherichia coli isolates in Juarez were more frequently resistant to aztreonam, cefazolin, cefepime, cefotaxime, ceftriaxone, ciprofloxacin, and gentamicin (p<.05) as compared to those in El Paso. Extended spectrum betalactamases (ESBL)-producing Escherichia coli were more prevalent in Juarez as compared to El Paso. Pseudomonas aeruginosa isolates in Juarez were more frequently resistant to amikacin, aztreonam, ceftazidime, ciprofloxacin, gentamicin, piperacillin/tazobactam, and tobramycin as compared to those in El Paso (p<.05).Conclusion: We documented significant differences in bacterial resistance between the two cities for Escherichia coli and Pseudomonas aeruginosa isolates. Although we encountered some variations, these differences supported that antimicrobial resistance is more prevalent in Juarez, Mexico than in El Paso, Texas for these two organisms.