Multidrug-resistant Escherichia coli clonal groups causing community-acquired pyelonephritis.

Area of Science:

• Microbiology
• Infectious Diseases
• Epidemiology

Background:

• Urinary tract infections (UTIs) are common, with increasing antimicrobial resistance posing a significant challenge.
• Trimethoprim-sulfamethoxazole (TMP-SMZ) is a common antibiotic for UTIs, but resistance is rising.
• Specific Escherichia coli (E. coli) clonal groups may disproportionately contribute to resistant infections.

Purpose of the Study:

• To determine the prevalence of pyelonephritis caused by a specific E. coli clonal group (CgA) in a California community.
• To investigate the association between E. coli clonal groups and trimethoprim-sulfamethoxazole (TMP-SMZ) resistance in pyelonephritis cases.

Main Methods:

• Enterobacterial repetitive intergenic consensus (ERIC2) polymerase chain reaction (PCR) was used for E. coli characterization.
• Serogrouping and pulsed-field gel electrophoresis (PFGE) were employed to analyze E. coli isolates.
• Retrospective analysis of UTI and pyelonephritis cases from October 1999 to January 2000.

Main Results:

• The E. coli clonal group CgA was linked to 57% of TMP-SMZ-resistant pyelonephritis cases.
• No association was found between CgA and TMP-SMZ-susceptible pyelonephritis.
• Most TMP-SMZ-resistant E. coli isolates belonged to distinct clonal groups (ERIC2 PCR), unlike susceptible strains with unique fingerprints.

Conclusions:

• A limited number of E. coli clonal groups may significantly impact the prevalence of antimicrobial-resistant pyelonephritis.
• Understanding E. coli clonal dynamics is crucial for managing antibiotic resistance in UTIs.
• Targeted interventions against specific resistant E. coli strains could be effective.