Interaction of Salmonella Gallinarum and Salmonella Enteritidis with peripheral leucocytes of hens with different laying performance

Abstract

Salmonella enterica ssp. enterica serovars Enteritidis (SE) and Gallinarum (SG) cause different diseases in chickens. However, both are able to reach the blood stream where heterophils and monocytes are potentially able to phagocytose and kill the pathogens. Using an ex vivo chicken whole blood infection model, we compared the complex interactions of the differentially host-adapted SE and SG with immune cells in blood samples of two White Leghorn chicken lines showing different laying performance (WLA: high producer; R11: low producer). In order to examine the dynamic interaction between peripheral blood leucocytes and the Salmonella serovars, we performed flow cytometric analyses and survival assays measuring (i) leucocyte numbers, (ii) pathogen association with immune cells, (iii) Salmonella viability and (iv) immune gene transcription in infected whole blood over a four-hour co-culture period. Inoculation of blood from the two chicken lines with Salmonella led primarily to an interaction of the bacteria with monocytes, followed by heterophils and thrombocytes. We found higher proportions of monocytes associated with SE than with SG. In blood samples of high producing chickens, a decrease in the numbers of both heterophils and Salmonella was observed. The Salmonella challenge induced transcription of interleukin-8 (IL-8) which was more pronounced in SG- than SE-inoculated blood of R11. In conclusion, the stronger interaction of monocytes with SE than SG and the better survivability of Salmonella in blood of low-producer chickens shows that the host–pathogen interaction and the strength of the immune defence depend on both the Salmonella serovar and the chicken line.

Transcriptional responses of cytokines, immunoglobulin A, and nitric oxide genes in one day old chicks post Salmonella typhimurium infection: An experimental study

“…The significantly dropped heterophil numbers might be due to stress-induced mechanisms or might be due to the death of intracellular bacteria and heterophils after Salmonella stimulation ( Pieper et al ., 2017 ). This result agreed with previous research ( Sornplang et al ., 2015 ), in which the chicks infected with SE showed lower phagocytic activity than controlled chicks at 24 and 48 hours, and another research ( Sreekantapuram et al ., 2021 ), in which the heterophils’ count in the blood of white Leghorn chickens decreased significantly after being infected with Salmonella . The number of heterophils was considerably lower ( p ≤ 0.05) between 60 and 180 minutes in blood samples that were infected with SE and between 90 and 150 minutes in blood samples that were infected with Salmonella gallinarium.…”

The Immuno-Suppressive Effects of Cyclic, Environmental Heat Stress in Broiler Chickens: Local and Systemic Inflammatory Responses to an Intradermal Injection of Lipopolysaccharide

“…Real-time qPCR was performed using TaqMan Universal Master Mix with UNG protocol in a 7500 Fast Real-Time PCR System (Thermo Fisher Scientific), as described in [ 23 ]. Using 28S as the reference gene to calculate target gene delta Ct, the relative gene expression was determined as 40 minus delta Ct [ 29 ].…”

Molecular Identification of invA gene from Salmonella species isolated from Human Sources in Southern Taraba, North-East Nigeria

“…Salmonella typhi and paratyphi A, B, C are the etiological agents of typhoid fever, and paratyphoid fever respectively in humans while several species of the NTS are responsible for gastroenteritis with Salmonella enteritidis and Salmonella typhimurium being the most isolated from clinical cases [1]. However, cases of foul typhoid have been documented but it is caused by Salmonella gallinarum [4]. Salmonella is a rod-shaped, gramnegative, motile bacterium whose reservoir is the intestines of various animals including humans [5].…”