Colonization Factor Antigens, Enterotoxigenic Escherichia coli, Enzyme-linked Immunosorbent Assay, Ganglioside GM1 , Hemagglutination

• Published in: Jundishapur journal of microbiology 2018-01, Vol.11 (1)
• Main Authors: Ifeanyichukwu Cajetan Ifeanyi, Casmir, Ikeneche, Nkiruka Florence, Bassey, Bassey Enya, Al-Gallas, Nazek, Alexander Casmir, Akpa, Nnennaya, Isu Rosemary
• Format: Article
• Language: English
• Subjects: Life Sciences; Microbiology and Parasitology
• ISSN: 2008-3645
• DOI: 10.5812/jjm.64269

Background: Heat-labile (LT) and heat-stable (ST) toxin variants of enterotoxigenic Escherichia coli (ETEC) are enterotoxins associated with diarrhea among children in Abuja, Nigeria. Enterotoxigenic Escherichia coli is also known as a major etiological agent of diarrheal disease among travelers in developing countries. Continuous identification of commonly expressed bacterial components of ETEC can help extend the protective spectra of future candidate ETEC vaccines in Nigeria. Objectives: This study aimed to provide new insights into the distribution patterns of enterotoxins, colonization factor antigens (CFA phenotypes), and serotypes and to determine the antimicrobial susceptibility patterns of ETEC strains from children with acute diarrhea in Abuja, Nigeria. Methods: Escherichia coli strains, isolated from the stool samples of children aged 0-60 months, were tested via polymerase chain reaction, ganglioside GM1 ELISA assay, hemagglutination assay, HEp-2 cell adherence assay, dot blot technique, and disc diffusion method for antimicrobial resistance. Results: Rnterotoxigenic Escherichia coli was detected in 16 (4.0%) out of 400 children with acute diarrhea. The toxigenic genotypes expressed by ETEC strains included LT toxin gene 6 (37.5%), ST toxin gene 6 (37.5%), and ST/LT gene 4 (25.0%). The CF phenotypes with major expression included CS2 (25.0%), CS3 (12.5%), and CFA1 (6.3%), with a probability value below 0.05 (P < 0.05). However, no CFA/CS was detected in 56.3% of ETEC strains. Multidrug resistance pattern of nalidixic acid-ciprofloxacin-amoxicillin-augmentin-cephalexin-cefuroxime was observed in 19% of ETEC strains. The most prevalent ETEC serotype was O8: H9 (n, 5). Based on the findings , ETEC infection peaked to 7.2% in July. Conclusion: Although ST and LT toxins seem to have equal distributions in the analyzed population, continuous identification of CFA phenotypes and toxins is necessary for the evaluation of ETEC vaccines in Nigeria.