Quantitative studies of the distribution pattern for Salmonella Enteritidis in the internal organs of chicken after oral challenge by a real-time PCR

Abstract

This research was undertaken to identify and understand the regular distribution pattern for Salmonella Enteritidis (S. enteritidis) in the internal organs of chicken after oral challenge over a 3 wk period. We used a real-time, fluorescence-based quantitative polymerase chain reaction (FQ-PCR) to detect genomic DNA of S. enteritidis in the blood and the internal organs, including heart, liver, spleen, kidney, pancreas, and gallbladder, from chicken after oral challenge at different time points. The results showed that the spleen was positive at 12 h post inoculation (PI), and the blood was at 14 h PI. The organism was detected in the liver and heart at 16 h PI, pancrea was positive at 20 h PI, and the final organ to show a positive results were the kidney and gallbladder at 22 h PI. The copy number of S. enteritidis DNA in each tissue reached a peak at 24 h-36 h PI, with the liver and spleen containing high concentrations of S. enteritidis, whereas the blood, heart, kidney, pancreas, and gallbladder had low concentrations. S. enteritidis populations began to decrease and were not detectable at 3 d PI, but were still present up to 12 d PI in the gallbladder, 2 wk for the liver, and 3 wk for the spleen without causing apparent symptoms. The results showed that the liver and spleen may be the primary sites for S. enteritidis setting itself up as a commensa over a long time after oral challenge. Interestingly, it may be the first time reported that the gallbladder is a site of carriage for S. enteritidis over a 12 d period. This study will help to understand the mechanisms of action of S. enteritidis infection in vivo.

The population of a high-virulence strain of Salmonella enterica serovar Enteritidis in subcutaneously infected partridge: a quantitative time-course study using real-time PCR

“…Severe hyperemia, hemorrhages, and heterophil infiltration in the lungs were also observed. The overall pattern of antigen distribution and microscopic lesions in the organs examined were similar to those reported in previous studies (Akaki et al 1997;Deng et al 2007Deng et al , 2008He et al 2010;Holt and Porter 1992;Yan et al 2008). The factors that determine the levels of S. Enteritidis load in various tissues have not been fully understood; however, the high S. Enteritidis DNA loads in multiple internal organs results in severe tissue pathology, which accelerates the progression of the infection.…”

“…The liver, spleen, lung, kidney, jejunum, ileum, rectum, cecum were analyzed by a fluorescent quencher PCR assay at postinoculation times of 30 min; 1, 2, 4, 8, 12, 24, and 36 h; and 2, 3, 6, and 9 day. At each time point, three partridges were randomly selected from the infection and control groups, and their tissue samples were collected and processed for further analyses. DNA extraction from the tissue samples was performed as described previously He et al 2010). Briefly, 0.5 g of the tissue sample was ground up using a tissue grinder in the 1.5 mL Eppendorf tube.…”

“…Quantitative real-time PCR assay for detection of S.Enteritidis DNA In our previous study, we have established a serovar specific real-time PCR assay He et al 2010). Briefly, a real-time PCR assay was carried out using a real-time PCR core kit (R-PCR version 2.1, TaKaRa, Japan) with an Icycler iQ TM Real-time PCR Detection System (version 3.1, Bio-Rad, USA) and was performed as described previously.…”

Allelic variation in Salmonella: an underappreciated driver of adaptation and virulence

“…Typically for host-restricted (e.g., serovar Typhi in humans) or host-adapted strains (e.g., serovar Dublin in bovines), but also for Salmonella with broad host range encountering stressed hosts or weakened host immune responses, (7) Salmonella can cause bacteremia. When disseminating Salmonella (whether or not host-adapted or restricted) can be somewhat controlled by the host, they typically settle in the liver, gallbladder (for mammals with this organ*), on calculi and in the biliary tract, where they can replicate and be released in the bile to return to the intestines (Oboegbulem and Muogbo, 1981; Cavallini et al, 1991; Wood et al, 1991; Pellegrini-Masini et al, 2004; Akoachere et al, 2009; He et al, 2010). …”

Replication Kinetics of <I>Salmonella</I> Enteritidis Live Vaccine in the Immune Organs of Chicken after Subcutaneous Immunization

“…Vaccination has been used as a preventive measure and also for controlling Salmonella Enteritidis outbreaks worldwide (He et al, 2010;Peng et al, 2011). Up to day, few data are present in the literature about the quantitative analysis of live Salmonella Enteritidis live vaccine in chicken at different times following vaccination.The mechanism for the rapid induction of immunity of attenuated Salmonella Enteritidis vaccine remain unclear.…”