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Year : 2018  |  Volume : 36  |  Issue : 4  |  Page : 547--556

Real-time multiplex polymerase chain reaction with high-resolution melting-curve analysis for the diagnosis of enteric infections associated with diarrheagenic Escherichia coli

Thingujam Surbala Devi1, Elantamilan Durairaj1, Wihiwot Valarie Lyngdoh1, Sourabh Gohain Duwarah2, Annie Bakorlin Khyriem1, Clarissa Jane Lyngdoh1 
1 Department of Microbiology, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong, Meghalaya, India
2 Department of Pediatrics, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong, Meghalaya, India

Correspondence Address:
Dr. Wihiwot Valarie Lyngdoh
Department of Microbiology, North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, Shillong - 793 018, Meghalaya
India

Introduction: Although diarrheagenic Escherichia coli (DEC) strains are important bacterial causative agents of diarrhoea, they are not routinely sought as stool pathogens in clinical laboratories as conventional microbiological testing are unable to distinguish between normal flora and pathogenic strains of E. coli. This study was undertaken to determine the prevalence of DEC pathotypes amongst children with and without diarrhoea and to detect specific virulent genes present in different DEC pathotypes, using real-time multiplex polymerase chain reaction (PCR) with high-resolution melting (HRM) technology. Materials and Methods: Stool samples were obtained from cases and controls. Using a set of conventional biochemical tests, E. coli strains were identified. Further, these isolates were subjected to multiplex PCR system for the detection of virulence genes of different pathotypes of DEC. Real-time multiplex PCR was performed for the detection of specific virulent genes of DEC pathotypes, using Rotor-Gene Q instrument (Qiagen) having High-resolution Melt analyser using Type-it HRM PCR kit (Qiagen) containing EvaGreen fluorescent intercalating dye. Results: In this study, we had successfully standardised two multiplex PCR assays which were found to be effective for direct detection of enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC) and enteroinvasive E. coli (EIEC). A total of 42 DEC strains were detected at an overall rate of 19.3% (n = 42), from the total 217 E. coli isolates recovered from the cases (n = 39, 17.9%) and control (n = 3, 3.8%) groups. Amongst the 42 DEC pathotypes (39 from cases and 3 from controls), EPEC (10%), EAEC (8.82%), ETEC (2.94%) and EIEC (1.18%) were found in children with diarrhoea (cases) and in children without diarrhoea (control) only EAEC (2.13%) and EPEC (4.26%) were detected. Age distribution, gender variation, seasonal variation and clinical features were also analysed Conclusion: This study helped evaluate the prevalence of DEC amongst children (<18 years of age) with and without diarrhoea using multiplex real-time PCR with HRM analysis.

How to cite this article:
Devi TS, Durairaj E, Lyngdoh WV, Duwarah SG, Khyriem AB, Lyngdoh CJ. Real-time multiplex polymerase chain reaction with high-resolution melting-curve analysis for the diagnosis of enteric infections associated with diarrheagenic Escherichia coli.Indian J Med Microbiol 2018;36:547-556

How to cite this URL:
Devi TS, Durairaj E, Lyngdoh WV, Duwarah SG, Khyriem AB, Lyngdoh CJ. Real-time multiplex polymerase chain reaction with high-resolution melting-curve analysis for the diagnosis of enteric infections associated with diarrheagenic Escherichia coli. Indian J Med Microbiol [serial online] 2018 [cited 2019 Aug 17 ];36:547-556
Available from: http://www.ijmm.org/article.asp?issn=0255-0857;year=2018;volume=36;issue=4;spage=547;epage=556;aulast=Devi;type=0