Isolation and identification of Escherichia coli, Salmonella and Pasteurella from holding grounds of live-bird markets at Addis Ababa, Ethiopia

A cross-sectional study was conducted to isolate and identify of Escherchia coli, Pastuerella multocida, Salmonella gallinarum and Salmonella pullorum from the holding grounds of five purposively selected Addis Ababa live bird markets from November 2016 to May 2017 using bacterial culture, grams staining and biochemical testing. A total of 90 pooled fecal samples were collected as both deep (35) (bottom layer of the feces) and surface (55) (top layer of the feces). The specimens were inoculated directly into blood agar and incubated at 37°C for 24 h. After subsequent subcultures of the colony on the blood agar, to get pure colonies, the isolates were cultured on MacConkey agar and Salmonella shigella agar to differentiate bacterial colonies. Gram staining and biochemical tests were carried out on the pure colonies and a loop of the isolates were inoculated into nutrient broth and kept for further investigation of the bacteria. The results of the study revealed that, out of the 90 total samples examined, 32 (35.55%) of the samples were found to be positive for E. coli. Based on the sample types the study indicated that 55 (61.10%) surface fecal samples, 32 (58.20%) samples were positive for E. coli, and in 35 (38.90%) deep fecal layers, there was no E. coli positive samples. There was a statistically significant difference between sample types and E. coli isolation rate (p< 0.05). P. multocida, S. gallinarum and S. pullorum were not found during this study. Live bird markets may serve as source of public health and economically important bacteria; however, further microbiological and epidemiological investigation is needed to determine the types of major bacteria predominating in the Addis Ababa live-bird markets and the roles and magnitudes played by these markets in the epidemiology of these pathogens.