Isolation and Identification of Bacterial Pathogens in Poultry Liver from Post-mortem Specimens in Iraq Using the VITEK® 2 Compact System
Zainab M. Albermani *
Department of Anatomy and Histology, College of Veterinary Medicine Kufa University, Najaf, Iraq.
*Author to whom correspondence should be addressed.
Abstract
Introduction: Bacterial liver infections in poultry cause significant mortality and economic losses, with pathogens like Escherichia coli, Salmonella, and Pasteurella multocida implicated in sepsis, necrosis, and systemic disease. The use of the VITEK® 2 system enabled rapid identification and susceptibility testing of the pathogens, contributing to a better understanding of microbial threats in poultry production. The findings emphasize the significance of bacterial sepsis as a cause of mortality in broilers and highlight the importance of rapid diagnostic techniques in veterinary practice.
Aim: This study aimed to isolate and identify bacterial pathogens in post-mortem poultry liver specimens and to determine their antimicrobial resistance profiles.
Methodology: Seventy-five poultry liver samples were aseptically collected during post-mortem examination, homogenized, cultured on selective media, and identified using the VITEK® 2 Compact System with antimicrobial susceptibility testing.
Results: The results revealed that 68% of the examined liver samples had high bacterial loads (≥10⁶ CFU/g), indicating significant microbial involvement in the birds' mortality. Among the isolates, Escherichia coli was the most frequently detected bacterium (42%), followed by Klebsiella spp. (28%) and Staphylococcus aureus (5%). Interestingly, no bacterial growth was observed in 25% of the samples, identified E. coli, Staphylococcus aureus, and Klebsiella pneumoniae as predominant pathogens. E. coli exhibited resistance to beta-lactams (e.g., ampicillin, piperacillin) and fluoroquinolones (ciprofloxacin) but susceptibility to carbapenems (imipenem, meropenem), aminoglycosides (amikacin, gentamicin), and tigecycline. K. pneumoniae isolates showed multidrug resistance (including to fluoroquinolones and trimethoprim-sulfamethoxazole) but remained susceptible to carbapenems and aminoglycosides. S. aureus was methicillin-sensitive but resistant to moxifloxacin and fusidic acid.
Conclusion: The study concludes that automated systems like VITEK® 2 enable rapid, targeted therapy and antimicrobial stewardship, crucial for mitigating poultry mortality and combating resistance linked to bacterial liver sepsis. This study underlines the necessity of improving diagnostic capabilities and monitoring resistance patterns to enhance poultry health, reduce losses, and maintain food safety standards in commercial poultry operations.
Keywords: Bacterial sepsis, VITEK® 2 compact system, Escherichia coli, antimicrobial resistance, broiler mortality