Virulence Phenotype of Avian Pathogenic Escherichia coli (APEC) and Prevalence of Colibacillosis among Poultry Birds in Bauchi Metropolis, Nigeria

Abstract

Background and Aim: Avian pathogenic Escherichia coli (APEC), a major cause of colibacillosis, is mainly associated with respiratory tract or systemic infections that lead to a variety of diseases. Avian pathogenic Escherichia coli infections include acute fatal Septicemia, and subacute pericarditis, which are responsible for severe economic losses worldwide in the poultry industry. The study aimed to determine the virulence phenotype and prevalence of colibacillosis among poultry birds in Bauchi metropolis. Methods: Faecal, internal organs and poultry house air samples were collected systematically from the birds in selected poultry farms within the Bauchi metropolis. APEC was isolated and characterized using standard phenotypic conventional microbiological techniques. Results: The study found that colibacillosis is caused by virulent strain of APEC with Haemolysin (59.6%) and type 1 fimbriae (40.4%) phenotypes, with high prevalence (100%) of colibacillosis in faecal samples, indicating faeces as a significant reservoir for APEC and a potential source of transmission. A moderate correlation (0.592) was observed among sample types. The occurrence of APEC was higher in faecal samples compared to internal organs. Birds with internal organ infections showed a 26.0% mortality rate, with younger (30.7%), female (69.3%), and layer birds (53.8%) being more vulnerable. The disease is more common (15.3%) in birds from the populated area of Federal low-cost housing estates in the study area. High prevalence with mortality cases was also found in younger birds (46.1%), mostly female (65.3%) and Layers (73.0%). But the highest mortality rates was observed in the adult (61.5%), Female (69.3%), and Layers (53.8%). Conclusion: The highest Colibacillosis prevalence was recorded in faeces. The occurrence rate of APEC was higher in faeces followed by internal organs from GRA and Gida Dubu among sample locations internal organ samples showed 26% mortality, with no deaths in other birds; younger, female, and layer birds have higher APEC mortality. It is recommended that further study should be conducted to trace the phylogenetic relationship of the virulent APEC isolates in the study area with other related sequences.  This study also emphasizes the need for proper diagnosis of bacteria to decrease the prevalence of Colibacillosis in the area.