Abstract:
Pathogenic E. coli strains cause diarrheal infection in both calves and children due to their
virulence factors.Their distribution is not well studied in Ethiopia, especially in current study
area. Therefore, a cross sectional study was conducted from October 2017 to June 2018, with
aim to isolate, molecularly detect pathogenic E. coli strains, to determine their antimicrobial
susceptibility patterns and associated risk factors in diarrheic calves and children at Wolaita
Sodo town. Purposive sampling technique was used to collect 88 feacal samples from
diarrheic calves and 110 stool samples from diarrheic children. Semi-structured questionnaire,
conventional culture, biochemical and molecular methods were conducted to achieve the
objectives. Antimicrobial susceptibility patterns of the isolates were tested using the KirbyBauer disc diffusion method. All of the data were analysed using logistic regression in SPSS
vertion 20. The overall isolation rate of E. coli in calves was 64.8% (57/88) (95% CI: 53.9-
74.7%). The occurrence of the bacterium differed significantly by age and colostrum feeding
time (P<0.05). The odds of being infected was highest in calves aged below two weeks (OR
4.3; 95% CI 34.8- 56.4%; P=0.001). The overall isolation rate of E. coli in children was
61.8% (68/110) (95% CI: 52.1-70.9%). The occurrence of the bacterium differed
significantly by age, contact with either animals or manure, negligence to hand washing
before meal and exclusive breast feeding in six month (P<0.05). The odds of being infected
was highest in children whose caretakers had habit of negligence to hand washing before meal
(OR 6; 95% CI 30.8- 49.8%; P=0.01). For eleven drugs, E. coli isolates were resistant to
(62.5%, 61.9%), intermidiately resistant to (3.5%, 9.4%) and susceptible to (34%, 28.7%) in
calves and children, respectively. The overall virulent genes detected in calves and children
was 77.2% (44/57) (95% CI 53.9-74.7%); and 55.9% (38/68) (95% CI 52.1%-70.9%),
respectively. Among these stx1 [8 (14%), 6 (8.8%)] stx2, [5 (8.8%), 4 (5.9%)], eaeA [8
(14%), 5 (7.4%)], eaat [6 (10.5%), 14 (20.5%)] and St [5 (8.8%), 4 (5.9%)] were detected
from calves and children, respectively. The MDR for E. coli isolates and their strains was 34
(59.7%) and 31 (70.5%), respectively in calves and 43 (63.2%) and 38 (100%) respectively in
children.The MDR index value of DEC pathotypes was greater than or equal to 0.4 which
indicates the high risk of resistance.The study demonstrated important pathogenic E. coli
strains; and multi-drug resistance mostly in isolates containing more than one virulent gene.
Wise use of antimicrobials and improving the hygienic practices in the farms and amongst
parents of children reduces its occurrence.Therefore, awareness on importance of exclusive
breast feeding to parents of children and colostrums feeding time for calves to farm owners
should be maximized. Appropriate usage of antimicrobial agents should also be highly
practiced among farms and hospitals
