Multi-Drug Resistant Escherichia Coli In Northern Nevada Acute Care Facilities

Background: Escherichia coli is the leading Gram negative bacteria isolated from acute care patients in northern Nevada and is a leading cause of urinary tract infections and sepsis. Urosepsis is associated with approximately 312 million dollars in healthcare expenses annually in Washoe County. Resistant E. coli is becoming more of a treatment problem, and statewide antimicrobial stewardship programs are not consistently implemented. E. coliresistant patterns were evaluated in Northern Nevada to understand past and future trends.

Methods: All acute care medical facilities (n= 5) were recruited that serve Washoe County, which represents a patient catchment area of approximately 500,000 people within 7280 square miles of urban and rural environments. To approximate population level Escherichia coliantimicrobial resistance patterns, facility level antibiograms derived from blood cultures was examined from 2002 to the present. Resistance trends were analyzed using joinpoint trend regression. Joinpoint regression utilizes Monte Carlo permutation testing of whether apparent changes in trends are statistically significant. Predicted trends were calculated from annualized average percent changes.

Results: Several antimicrobials were associated with statistically significant decline of susceptibilities below 85% : cefazolin, amoxicillin-clavulanate, ciprofloxacin, levofloxacin, and trimethoprim-sulfamethoxazole. Two facilities were associated with non-significant stabilization of ciprofloxacin resistance beginning in 2008-2009, however susceptibilities currently remain between 70-80% with no evidence of improvement. Antimicrobials predicted to have a statistically significant decrease of E. coli susceptibilities below 85% within the next 10 to 15 years included ceftazidime, cefuroxime, ceftriaxone, gentamicin, and tobramycin.

Conclusion: Multi-Drug Resistant (MDR) E. coli is present in northern Nevada, with limited evidence that antimicrobial stewardship has impeded the progression of antimicrobial resistance at the population level. Northern Nevada faces significant challenges when adapting prescriber guidance for urinary tract infections to these findings in the context of MDR E. coli-associated sepsis.