Isolation and identification of some possible causative agents of swollen head syndrome (SHS) in broiler chickens in Egypt

Abstract

The current study was designed to detect, isolate and identify the etiological agents of SHS in chicken flocks in Egypt. Clinical samples, including the trachea, lung and choanal cleft swabs, from different flocks, ages and localities were collected from non-vaccinated commercial broiler flocks with respiratory signs then transmitted directly to the laboratory for further examination. Avian metapneumovirus RNA (aMPV RNA) was extracted then amplified using one step RT-PCR using both subtype A and B (G gene) primers then differentiation occurred by real time PCR (qPCR). Swab samples from subcutaneous edema and exudates were directly cultured and the suspected bacterial colonies were biochemically identified then confirmed by PCR. Four samples were positive and one doubtful for aMPV using RT-PCR confirmed by qPCR. Bacteria isolation revealed that out of 40 samples, 16 samples were positive for E.coli, 4 samples were positive for P. aeruginosa, 6 samples were positive for P. mirabilis, 4 were mixed E. coli and P. aeruginosa, 8 were mixed E. coli with P. mirabilis and 2 samples were mixed P. mirabilis and P. aeruginosa. Depending on these findings, we could prescribe a preliminary guide to decrease SHS outbreaks by primary control of bacterial complication.