Basic Informations

C.V

         Name: Fatma Ibrahem Mohamed El-sayed

Birth date: 7/3/1995

Major Field:  Zoonoses

Address: Faculty of Veterinary Medicine, Beni-Suef University

Master Title

Prevalence, genotyping, and virulence factors of pathogenic E. coli in cattle and humans

Master Abstract

Summary In the current study, fecal samples were collected from 410 cows and 41 buffaloes as well as milk samples were obtained from 90 cows in addition to 234 human samples including 125 stool and 109 urine samples in the period of January 2021 through July 2022 from various localities in Beni-Suef and Minya governorates, Egypt. These samples were subjected to examination for E. coli of public health implications. Cattle examined in this study were reared in small-holders or in farms. Animal data including age, sex, and history of enteric diseases including, those diarrheic and a group of non-diarrheic animals were collected. Humans chosen for this work were either livestock-related; those associated with close contact with the examined cattle or non-livestock-related who comprised individuals residents in urban areas. Samples included 125 stool and 109 urine samples. A detailed questionnaire was filled out for everyone including age, sex, residence, and occupation, degree of animal contact and the recorded signs, and symptoms. The age grouping ranged from less than 10 years to more than 31 years. . Bacteriological examination showed an overall prevalence of E. coli 44.9% and 22.2 % in the examined feces and milk from cows, respectively, while E. coli was detected in 51.2% of buffalo feces. Shifting to humans, E. coli was isolated from 38.4% of stool and 28.4% of urine samples. According to the health status, it was found that fecal shedding of E. coli was more prominent in diarrheic cattle (47.7%) than non-diarrheic ones (39.2%). It was worth mentioning that cattle less than 1 month suffering from diarrhea were highly susceptible to E. coli infection (57.1%) than older ones (29.7%). Regarding the frequency of E. coli infection in relation to seasonal variation, the prevalence was much higher in winter (52.0%) than in summer (30.6%). The occurrence of E. coli in cattle fecal samples in relation to the rearing system indicated that fecal shedding of E. coli was more prominent in farmed animals (55.7%; 88 out of 158) than that small holders reared ones (39.9%; 117 out of 293). As well, it was higher in milk samples from farmed animals than those reared in small holders (24.6% and 18.2%, respectively). In humans, data represented the higher isolation of E. coli from urine at age of 1-10 years (56.5%) than those of >31years (17.4%) while the recovery rate of E. coli from stool was 57.1% in individuals aged >30 followed by those 1-10 years (39.8%), but those aged 11-30 years accounted for the lowest isolation rate (21.7%). E. coli serogroups were analyzed in a total of 20 isolates from milk, feces, stool, and urine. E. coli was recovered with different percentages and biotypes. Concerning the serological identification of the recovered E. coli in the cattle fecal samples, the serotypes were O86:K61, O55:K59 (EPEC, EHEC), O126:H71 (EPEC, EHEC), and O119:K69 (EPEC, EHEC). The identified serotypes in milk samples were O86:K6 (EPEC, EAEC), O44:K74 (EPEC, EAEC, EHEC), O128:K67 (EPEC, ETEC, EHEC), and O111:K58 (EPEC, EHEC, EAEC). Concerning the serological identification of the recovered E. coli from human urine and stool samples, it was denoted that serotypes O86:K6 and O91 (EPEC, EHEC) were recorded in urine and stool, while O55:K59 and O78:K80 (EAEC, ETEC) were serotyped in urine only. Also, serotypes O128:K67 and O111:K58 were recovered from stool samples. Virulence, pathotypes and quorum-related genes were analyzed using the conventional PCR in the serologically identified strains from milk, fecal, stool, and urine samples. Virulence markers (Iss, IutA, and Tsh) were found in O86:K6, O55:K59, O44:K74, O128:K67, O111:K58, and O91, whereas only Iss and IutA genes were harbored in O126:H71, O119:K69 and O78:K80 from feces and urine. Concerning the pathotypes-related genes, ChuA, YjaA, and TspE4C2 were identified in O86:K6, O55:K59, O126:H71, O91, O119:K69, and O78:K80 in samples of different sources but ChuA and TspE4C2 genes were found in O44:K74 and O111:K58 from milk and stool. Moreover, the serotype O128:K67 identified in milk and stool samples yielded YjaA and Tsp4c2 genes. It was surprising that the quorum sensing (QS) marker amplified LuxS gene in all serotypes. EaeA gene was detected in O86:K61, O128:K67, O91: K, and O111:K58 in samples of different sources. Furthermore, Hly gene was detected only in O91: K in urine and stool. Additionally, Stx1 was found only in O128:K67 of milk, and stool samples. The obtained results of the antibiotic susceptibility pattern revealed that the screened E. coli isolates (n=100) were remarkably resistant to two or more of the tested antibiotics, a phenomenon known as MDR. Similarly, both human and animal samples were entirely resistant to Doxycycline and Lincomycin (100%) at P<0.001. Complete resistance to Gentamicin, Colistin, and Clotrimazole (100%) was also observed in isolates from feces and urine. Amikacin and Norfloxacin showed complete resistance in milk and urine (100%) at P<0.001, respectively. Additionally, all samples showed a higher degree of resistance to Fosfomycin, Spectinomycin, Erythromycin, and Enrfloxacin. On the other hand, strains recovered from fecal, milk, urine, and stool samples were highly sensitive primarily to Ciprofloxacin (80.0, 66.7, 60.0, and 50.0 %, respectively) at P<0.001. Variable degrees of resistance were noted against the other used antibiotics. The biocidal effect of some essential oils including thyme, peppermint, capsaicin, orange, green tea, tea tree, and onion at concentrations of 0.5% and 1.0% was done against 17 selected multi-drug resistant, virulent, and quorum sensing determinants from the identified E. coli of animal and human sources. It was revealed that at a concentration of 0.5 %, capsaicin, orange, and onion EOs failed to prevent bacterial development; however, peppermint (23.5%) and green tea (17.6%) had little effect on E. coli multiplication. At a concentration of 1.0%, peppermint demonstrated the most prevalent bioactive effect (100%), followed by capsaicin, orange, onion, and green tea, which showed rates of 88.2, 58.8, 47.1, and 29.4%, respectively at P<0.001. Thyme oil, on the other hand, failed to show any reduction of bacterial growth (0.0%) at both concentrations tested. Conversly, tea essential oil had the maximum bio-control efficacy against E. coli at the two concentrations applied (P<0.001).

PHD Title

PHD Abstract