Characterization of Paratyphoid Salmonellae Isolated from Broiler Chickens at Sharkia Governorate, Egypt

Paratyphoid Salmonella has emerged as a global problem for humans and poultry.Therefore, in this study we investigated the occurrence, serological, antimicrobial and molecular characteristics of paratyphoid Salmonella isolated from chicken flocks at Sharkia Governorate during 2015-2016. The prevalence of paratyphoid Salmonella among the 150 suspected flocks was 32.6 % (49/150), the highest rate (41/49; 80%) was among young ages (1-10 days old) and the lowest rate (8/49; 16 %) among older ages (11- 21 days old). The highest recovery was from liver (30.66 %), followed by spleen (25.33 %), caecum (20 %) and yolk sac (15.7 %). Serotyping of 49 Salmonella isolates revealed 11 different serogroups, with Salmonella Typhimurium was the most prevalent one (24.49 %), followed by Salmonella Kentucky (18.36 %) and Salmonella Enteritidis (14.28 %). The most sensitive antibiotics were apramycin (82 %) and ciprofloxacin (65 %). Multidrug resistance (MDR) was significant to ampicillin, gentamycin and cefotriaxone in all Salmonella isolates. All phenotypically identified MDR Salmonella were found to possess invA, hilA, pefA (100%) and avrA (95 %) genes by polymerase chain reaction (PCR), confirming that these virulence genes are important virulence markers for rapid diagnosis of Salmonella infection.