Pathogenicity of Salmonella enteritidis phage types 4, 8 and 23 in specific pathogen free chicks

Abstract

The pathogenicity of two isolates of Salmonella enterica serovar Enteritidis (SE) phage type (PT) 4, three of PT8 and one of PT23 was investigated in groups of 1-day-old specific pathogen free White Leghorn chicks. Two groups were crop gavaged with each culture but at two different doses. Two additional groups were given Salmonella enterica serovar Pullorum (SP) at similar doses and one further group served as uninoculated controls. Body weights were recorded at 14, 21, and 28 days postinoculation (d.p.i), and mortality was monitored throughout. In most treatment groups, the average body weights were significantly lower than the controls. Birds inoculated with SP had the highest mortality followed by those given SE PT4 of human or chicken origin. At 14 and 21 d.p.i., four chicks from each group were killed and examined for gross lesions. Selected tissues were collected for histopathology and cultured for bacteria. Dead birds had fibrinous exudate in the pericardium and also, in a few, on the liver capsule. They had enlarged livers, sometimes with congestion and white foci. At 7 d.p.i., several birds, especially those inoculated with SE PT4, had retained yolk sacs containing coagulated material. Microscopic lesions of pericarditis, myocarditis, hepatitis, splenitis, peritonitis and enteritis were present at 7 d.p.i. in most birds inoculated with SE, but was greatly variable at 14 d.p.i.. This study shows that 1-day-old SPF chicks are susceptible to various phage types of SE, with yolk-sac infection as the most prominent feature.

Effects of Orally Administered Bdellovibrio bacteriovorus on the Well-Being and Salmonella Colonization of Young Chicks

“…It has been published previously by others that the Salmonella Enteritidis PT4 infection of chicks causes full white ceca due to infiltration by white blood cells (1,2,16,36,42). We found these cecal abnormalities in our studies.…”

“…3). In addition, only birds treated with predatory wild-type Bdellovibrio had a significantly smaller proportion of abnormal ceca (which showed inflammatory characteristics described previously [1,2,16,36,42]) than that of untreated controls (Table 1 and Fig. 4).…”

“…The horizontal line represents the means for each group. (1,2,16,36,42) to cause pale ceca with dense nonfree-flowing contents due to inflammation and white blood cell infiltration. a Shown are the number of cecal abnormalities in each treatment group on each day following treatment.…”

Establishment of a pathogenicity index in Salmonella Enteritidis and Salmonella Typhimurium strains inoculated in one-day-old broiler chicks

“…Between the evaluated lesions, aerossaculitis, peritonitis and onfalitis were the most common occurrences in both studied serotypes. These findings are similar to the ones described by many researches after experimental infection with S. Enteritidis (Desmidt et al, 1997;Dhillon et al, 1999;Alisantosa et al, 2000;Dhillon et al, 2001;Akthar et al, 2011;Akthar et al, 2013) and S. Typhimurium in Specific Pathogens Free (SPF) birds between one and twenty-eight days.…”

“…Based on this, it is suggested that both serotypes have the potential to cause septicemic lesions such as the ones caused by the avian specific serotypes. This hypothesis is suggested by other authors who have found the same macroscopic alterations after experimental inoculation with S. Enteritidis, S. Typhimurium, and S. Pullorum (Alisantosa et al, 2000;Dhillon et al, 2001;Roy et al, 2001). (Smith and Tucker, 1980).…”