Evaluation of 3-week-old layer chicks intratracheally challenged with isolates from serogroup c1 (O:6,7) and Enteritidis.

With the exception to serotype Typhimurium and Enteritidis (serogroups B [O:4] and D [O:9], respectively), there have been very few studies conducted on the respiratory tract as route of infection in chickens with salmonellas from serogroup C1 (O:6,7) Therefore, the purpose of this present study was to determine the potential organ invasion by serotype Potsdam (SP), Mbandaka (SM), and Infantis (SI) from serogroup C1 (O:6,7) and compare their characteristics with those of Enteritidis (SE) on intratracheally (IT) challenged 3-week-old layer chicks. A total of 360 one-day-old White Leghorn layer chicks were acquired from a commercial hatchery and randomly assigned into four treatment groups (SP, SM, SI, and SE, respectively), consisting of three independent trials. Chicks were grown up to 21 days (3 weeks) and IT-challenged thereafter with 10 CFU of respective salmonella organisms per group ( = 30). Chicks ( = 5) were humanely sacrificed every 24 h for 6 days post-IT infection and organs such as lung, heart, liver, spleen, kidney and caecal content were cultured for salmonella. All treatment groups exhibited colonization of lungs and caecal contents at 1 d (= 0.475) and 4 d (= 0.696) post-IT infection, respectively. There was no isolation of SP, SM, and SI in heart, liver, spleen, and kidney. In contrast, SE was obtained from heart, liver, and spleen of IT-infected chicks. The findings of this study contribute to a better understanding of the importance of the respiratory route in salmonella infection in poultry.