Journal details
Pathogenecity of E. coli in mice isolated from fecal samples of zoo animals
Published Date: 30 Dec 2015
Keywords: Escherichia coli, PCR, pathogenicity, zoo animal.
Sharmin Aktar*1, Sukumar Saha1, Md.Jalal Uddin Sarder2, Md. Munsurul Amin1, Md. Hemayatul Islam2, Jaidul Hassan1 and Mohammad Ferdousur Rahman Khan1
1Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh- 2202, Bangladesh, 2Department of Animal Husbandry and Veterinary Science, Rajshahi University, Rajshahi-6205, Bangladesh
Abastract:
Objectives: Certain strains of E. coli produce potentially lethal toxins. Food poisoning caused by E. coli can result from eating unwashed vegetables or poorly butchered meat which delivered to Zoo animals.
Materials and Methods: A total of 62 samples were collected aseptically and subjected to primary isolation by propagating in nutrient broth followed by culture on different agar media. Gram’s staining and hanging drop techniques were also performed. Biochemical properties of the isolates were studied. Pathogenicity of 50 representative E. coli isolates were determined by lethality assay in adult mice models. E. coli was isolated successfully from 27 Samples out of 31 samples collected from seven species of animals of Rajshahi Zoo and 22 samples out of 31 samples collected from seven species of animals of Dhaka Zoo. All the E. coli isolates were found to produce bright pink colonies on MacConkey agar, yellowish green colonies surrounded by an intense yellow green zone on Brilliant Green (BG) agar and characteristic metallic sheen colonies on the Eosine Methyline Blue (EMB) agar. In Gram’s staining technique, all the isolates were pink coloured, indicating Gram negative small bacilli while in the hanging drop technique the organisms were motile.
Results: All the E. coli isolates fermented dextrose, maltose, lactose, sucrose and mannitol with the production of both acid and gas. The results of catalase, MR and indole tests with E. coli isolates were positive but V-P test was negative. In the mice lethality assay, 5 E. coli isolates were virulent causing 10% death of the mice.
Conclusion: After mice lethality assay five pathogenic E. coli mainly isolated from carnivore animals in Dhaka zoo and Herbivore animals in Rajshahi zoo. Among five pathogenic E. coli, three of them found from Rajshahi zoo animals and two from Dhaka zoo animals.