Prevalence, Antimicrobial Resistance, and Phylogenetic Characterization of Esbl-Producing Escherichia Coli Isolated from Clinical Specimens in Can Tho, Vietnam

Abstract

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli poses a significant public health threat due to their capacity to inactivate broad-spectrum β-lactam antibiotics and accumulate multidrug resistance. This study aimed to investigate the prevalence, antimicrobial resistance profiles, ESBL-encoding genes, and phylogenetic groups of ESBL-producing E. coli isolated from clinical specimens at a major hospital in Can Tho, Vietnam. A total of 148 isolates were obtained from healthy individuals between 2024 and 2025, primarily from pus, sputum, urine, and blood samples, although the relatively small sample size may not fully represent the wider Can Tho population. Specimens were analyzed using selective culture, biochemical identification, and PCR assays for resistance genes (blaCTX-M, blaTEM, blaSHV) and phylogenetic groups (A, B1, B2, D). ESBL production was confirmed in 58.7% of isolates. Group D was predominant (42.0%), especially in extraintestinal specimens such as pus and sputum, highlighting its potential role in both asymptomatic carriage and clinical infection. High resistance rates were observed to ampicillin (99.3%), cefazolin (76.1%), and ciprofloxacin (71.7%), with amikacin showing the highest efficacy (97.1%). Gender-related variations in resistance were also noted, particularly in β-lactam response. Multi-drug, extensively-drug, and pan-drug resistance patterns significantly correlated with phylogenetic background. These findings underscore the urgent need for surveillance and stewardship strategies, particularly targeting high-risk clones such as group D to prevent community transmission.