Prevalence of E. coli Pathotypes: A Comparative Study between Clinical and Environmental Isolates

Document Type : New and original researches in the field of Microbiology.

Authors

Microbiology and Immunology Department, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt

Abstract

Background: The pervasive species of Escherichia coli range from avirulent to extremely pathogenic strains. Pathogenic strains are a serious public health concern globally, causing gastrointestinal infections or disseminate throughout the body, causing  urinary tract infections, and sepsis/meningitis. Among bacterial etiologic agents of gastrointestinal infections, diarrheagenic Escherichia coli (DEC) is the predominant cause of severe diarrhea. Objective: This study aims at determining the prevalence of Escherichia coli pathotypes and serotypes among clinical and environmental isolates. Methodology: A total of 105 presumptive isolates of E. coli were obtained from different clinical (118) and environmental (217) specimens. Confirmed E. coli isolates were subjected to serological identification, as well as determination of pathotypes. Statistical data analysis was performed applying Fisher’s exact test. Results: Of the 335 presumptive specimens, 31.3% (105/335) were confirmed as E. coli. Seropathotyping of the confirmed isolates showed their distribution as 49.5% EHEC, 26.7% EPEC, 18.1% ETEC, and 5.7% EIEC. Alarmingly, high rate of EHEC and ETEC were observed among dairy and meat products (50% and 20%, respectively), while a low rate belonged to EIEC pathotype. Concerning E. coli clinical isolates, EHEC followed by EPEC were the most prevalent pathotypes. Regarding serotypes distribution, the most prevalent serotype among environmental isolates was O26: H11, whereas the most common serotype among clinical isolates was O128: H2. Serotypes O26: H11 and O125: H21 were significantly more prevalent among environmental isolates than clinical isolates, while serotypes O126: H21, O55: H7, O119: H6, and O128: H2 were significantly more prevalent among clinical isolates. Conclusion: This research emphasizes the issue of pathogenic pathotypes becoming progressively prevalent in Egypt. We concluded that pathogenic E. coli has been detected not solely in hospitals, but also in food and dairy products rendering them to be possible reservoirs and vehicles for this pathogen.
 

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