Epidemiologic characteristics and pathogen analysis of Diarrheagenic Escherichia coli in Huzhou, 2018-2020

Abstract

ObjectiveTo investigate the infection status, main virulence genes and drug resistance of diarrheagenic Escherichia coli (DEC) in the diarrhea population in Huzhou, Zhejiang Province.MethodsDECs were isolated from fecal specimens from patients with diarrhea in three sentinel hospitals from 2018 to 2020. All clinical isolates were then further identified using multiplex real-time fluorescence quantitative polymerase chain reaction (PCR). The microbroth dilution method was used for drug sensitivity testing.ResultsA total of 293 DEC positive cases were detected, and 294 strains were isolated. Enteroaggregative Escherichia coli (EAEC) accounted for 55.4% (163/294), and Enterotoxigenic Escherichia coli (EPEC) accounted for 29.6% (87/294). Enteropathogenic Escherichia coli (EPEC) accounted for 11.2% (33/294), Enteroinvasive Escherichia coli (EIEC) accounted for 3.4% (10/294) and Enterohemorrhagic Escherechia coli (EHEC)accounted for 0.3%(1/294). The antimicrobial resistance rates of 117 randomly selected strains to ampicillin, nalidixic acid, ampicillin-Sulbactam and tetracyclin were 70.9%, 60.7%, 53.8% and 51.3%, respectively. The multidrug resistance rate reached 55.6%. The sensitivity rates to imipenem, ceftazidime, amoxicillin clavulanic acid and cefoxitin were 99.1%, 92.3%, 92.3% and 91.5%. DEC cases had a peak in July to August, and the main infected population was between 20 and 39 years old.ConclusionThe DEC genotypes of the patients with diarrhea in Huzhou, Zhejiang Province were mainly EAEC and ETEC, with multiple antibiotic resistance. The distribution of cases was obviously seasonal, and the infected population was mainly young adults.

Keywords

• diarrheagenic escherichia coli
• epidemiologic characteristics
• virulence gene
• resistance