ISOLATION AND IDENTIFICATION OF SALMONELLA SPP AND E. COLI FROM DROMEDARY CAMEL CALVES WITH DIARRHEA IN SELECTED DISTRICTS OF EASTERN ETHIOPIA

Abstract

A cross sectional study design was implemented from October 2018 to December 2019 with a major objective of isolation and identification of Salmonella spp and E.coli from dromedary camel calves with diarrhea in selected districts of Eastern Ethiopia. Fecal samples were collected directly from the rectum of diarrheic camel calves. Isolation and identification of E.coli and Salmonella from faecal sample was cultured on EMB and MacConkey agar and incubated aerobically at 37°C for 24 to 48 hours. Colonies showing typical character of E. coli shiny with a characteristic smell and EMB agar was used to determine the characteristic of E. coli strains bright pink) was separated whereas the formation of red colonies with black centers and of pink colonies with a red zone was inspected on XLD and BGA plates, respectively. Data from the respondent’s interview questionnaire and laboratory findings were verified, compiled, coded, summarized and analyzed using statistical package for social science (SPSS Version 20) software. Chi -square (χ2) and logistic regression analysis was used to measure the association between the different risk factors and occurrence of camel calf diarrhea. From the total 172 herds examined, 80 (46.5%) were found to have at least one case of dromedary camel calve diarrhea. Based on risk factor analysis, the prevalence was significantly (p<0.05) higher in Babile district (54.0%) than Dire Dawa administration (36.1%) and the duration of colostrum feeding for 24 hrs (53.3%) than those with up to 48 hrs (51%) and > 48 hrs (30.4%). However, season, herd size, methods of colostrum feeding, and time of first colostrum feeding did not show significant difference (p>0.05).The multivariable logistic regression analysis showed that, herd diarrhea was 1.9 times (OR=1.9; 95%CI=0.1-3.5; p-value=0.053) higher in Babile than Dire Dawa. Moreover, herds with 24 hrs duration of colostrum feeding had 2.38 (OR=2.38; 95% CI=1.0-5.2; p=0.030) times of being positive for calves diarrhea than other categories. Thus, sex, age, study area, season, colostrum feeding method, and duration of colostrum feeding were found significantly associated (p<0.05) with calve diarrhea. Based on multivariable logistic regression analysis age, study area, season, and duration of colostrum feeding were found significantly associated (p<0.05) with calf diarrhea. Herd level distribution of E. coli and Salmonella in different kebeles was totally found to be 75% and 28.8%, respectively. With regard to the overall distribution of pathogens, E. coli was identified in all kebeles, while Salmonella was not isolated from >50% of the kebeles. Out of the herds examined with diarrhea, E. coli was found in 74.1% of herds from Babile, whereas 76.9% from Dire Dawa. Meanwhile, Salmonella was found in 27.8% and 30.8% herds from Babile and Dire Dawa, respectively. Out of the 152 diarrheic animals, 84 (55.3%; 95% CI= 46.9-63.3) were harboring E. coli. Based on the host risk factors, the occurrence of E. coli was significantly (p<0.05) higher in male (63.3%) than female (46.6%) and calves of <6months age (66.0%) than >6months old (50.0%). Out of the 152 diarrheic animals, 32 (21.1%; 95% CI= 14.9-28.4) were harboring Salmonella. However, significant association (p<0.05) was observed only with herd size and method of colostrum feeding, with higher occurrence in small herd size and animals with hand colostrum feeding, than their counter categories. Isolation and identification of E. coli and Salmonella among diarrheic camel calves and associated risk factors are highly prevalent. Effective prevention and control of camel calf diarrhea, adequate colostrum intake, and treatment of affected animals using fluid therapy should take as measures