Increasing Resistance of Nosocomial and Community-Acquired Escherichia coli in Clinical Samples from Hospitals and Clinics in Sana’a City

Abstract

Antimicrobial resistance in Escherichia coli presents a global challenge associated with nosocomial infections and increased mortality rates. Understanding resistance profiles is crucial for guiding treatment strategies and ensuring effective antibiotic use. This study aimed to investigate the prevalence and in vitro resistance of E. coli to community-acquired and nosocomial infections. Various clinical samples from 700 patients were cultured on MacConkey’s medium and blood agar. The disk diffusion method was used to determine the antibiotic susceptibility profile of the E. coli isolates following the guidelines of the Clinical and Laboratory Standards Institute (CLSI). Urine, pus, seminal fluid, vaginal swabs, and other body fluids were among the clinical samples analyzed. Of the 112 E. coli isolates, 48.2% were from inpatients and 51.8% were from outpatients, with the majority (66%) isolated from urine samples. Higher resistance levels were observed in the urinary isolates than that in the previously recorded data from the same institutions. Notably, isolates exhibited high resistance to penicillin (98.2%), ampicillin (97.3%), first-generation cephalosporins (90.2%), erythromycin (72.2%), and roxithromycin (95.4%), whereas lower resistance was noted against piperacillin-tazobactam (25.0%), nitrofurantoin (12.5%), and imipenem (9.8%). The overall multidrug resistance rate was 62.5%, with higher rates observed in nosocomial infections (70%) compared to community-acquired isolates (55.6%). However, this difference was not statistically significant (p>0.05). This study underscores the prevalence of E. coli isolates (27.0%) and highlights the concerning level of resistance, particularly to older antibiotics. These findings emphasize the importance of judicious antibiotic use and ongoing surveillance.

Keywords

• e. coli
• antibiotics
• antimicrobial resistance
• community-acquired infections
• nosocomial infections
• multidrug resistance
• urinary isolates