Studies on virulence gene profiling serotyping and epidemiology of shigatoxigenic and enteropathogenic e coli isolated from captive and free ranging wild mammals and birds

Abstract

India has great wildlife biodiversity and is home to myriad wildlife fauna. Wildlife plays newlineimportant role in of the planet ecosystem however, it often represents an important risk in emerging newlinezoonosis, scant information is available about the occurrence of zoonotic pathogens in wildlife newlineworldwide. Shigatoxigenic and Enteropathogenic Escherichia coli are two important classes of newlinezoonotic enteric pathogens. Epidemiology of STEC and EPEC is largely unknown in most of the newlinedeveloping countries including India. Recent, studies in have underlined the importance of wildlife newlinesurveillance, as large number of emerging zoonotic pathogens are found to be of wildlife origin. Thus, newlinewild animal should thoroughly be monitored, as they can potentially cause a spillover or spillback to newlinehuman and other domestic animals. In present study, 770 fecal sample were obtained from 598 wild newlineand 172 domestic animal during January 2021 to March 2022 from zoological gardens situated in newlinethree different geographical locations of the India and adjoining village near Accanakmar sanctuary newlineBilaspur Chhattisgarh respectively. Total 515 (86.12%) isolates were identified as E. coli from wild newlineanimals subjected to molecular screening for stx1, stx2, eaeA, and ehlyA genes by multiplex PCR. newlineTotal 75 (14.56%) isolates were successfully pathotyped and among these isolates STEC/AE-STEC newlineand EPEC virulence genes were detected in 42 (8.73%) and 33(6.40%)E. coli isolates respectively. newlineAll 33EPEC isolates were found to be atypical EPEC carrying only the eaeA gene. All 75 STEC / newlineEPEC isolates were serogrouped in29 different serotype, 3 isolates were untypeable (UT), and 1 newlineisolate was found to be rough strain. Serogroup O157 AE-STEC was detected in two isolates from newlinewild animals, one was isolated from red deer and other from peacock. Present study attempts to newlineinvestigate transmission of STEC and EPEC among domestic animal, poultry and free- ranging wild newlineanimal in shared agroecosystem. One AE-STEC O157 isolates each was isolated from peacock, newlinepoultry and goat. Which showed similar virulence profile All 75 isolates(STEC and EPEC) were newlinesubjected to invitro antibiotic sensitivity assay against 14 commonly used antibiotics (CLSI 2008), newlinewhich are showing varying resistance to tetracycline Norfloxacin cefuroxime, Gentamicin, newlineChloramphenicol, Co-Trimoxazole, Ampicillin and Azithromycin, however, no resistance was newlineobserved for cephalothin, ciprofloxacin, ceftriaxone, Ticarcillin+ clavulanic acid and Piperacillin + newlinetazobactam, Amikacin. SETC/EPEC isolates (12) from free-ranging wild animals were susceptible to newlineall 14 of antibiotics tested.AE-STEC, STEC and EPEC isolates differed in their ability to form biofilm newlineaccording to the temperature, time of incubation and surface used and are classified as no biofilm, newlineweak, moderate, or strong biofilm producers. The biofilm formation was more at 37°C than 20°C newlineduring initial 24 hrs. incubation and decreased with increasing incubation time at 37°C, as majority of newlineisolates developed highest biofilm mass at 24 hrs., post inoculation. All the AE-STEC, STEC and newlineEPEC isolates were capable to form biofilm. Our findings emphasize the role of wild animals as newlinereservoir of potentially pathogenic STEC and EPEC. newline