Detecting Some Virulent Bacterial Causes of Omphalitis in Broiler Chickens

Omphalitis is the main cause of mortality and low performance in broiler chicks. Detection of some virulent bacterial causes of yolk sac infection in broilers was the aim of this study. This investigation included 45 examined broiler flocks in Delta region of Egypt, aged 1-8 days old and suffered from high mortality, depression, diarrhea and low vitality. Bacterial isolation revealed 39 E. coli isolates (86.6%), 7 Salmonella isolates (15.5%), 6 Pseudomonas aeruginosa isolates (13.3%) and 3 coagulase-negative Staphylococcus isolates (6.6%). The polymerase chain reaction test used to detect virulent genes in these isolates revealed that all 4 examined E. coli isolates had iroN, hlyF and ompT genes. The invA, stn and fimA genes were detected in 4 examined S. Enteritidis isolates. Staphylococcus lentus isolate was positive to sea and tsst genes and negative to etb gene, and S. saprophyticus isolate was positive to sea, tsst and etb genes while S. xylosus was positive to etb gene and negative to sea and tsst genes. tox A, phzM and oprL genes were identified in 4 tested P. aeruginosa isolates. Antimicrobial sensitivity testing revealed that all 4 tested E. coli isolates were resistant to ampicillin while doxycycline and imipenem showed sensitivity. While the 4 examined S. Enteritidis isolates were resistant to ampicillin but showed sensitivity to gentamycin, amikacin and imipenem. The coagulase-negative Staphylococcus isolates were resistant to clindamycin but sensitive to doxycycline, ciprofloxacin and gentamycin. P. aeruginosa isolates (n=4) were resistant to imipenem and were sensitive to amikacin, cefepime and ciprofloxacin.