Acute phase responses of pigs challenged orally with Salmonella typhimurium.

Abstract

This study evaluated responses of the systemic endocrine stress (cortisol) and growth (IGF-I, GH) axes, as well as those of inflammatory mediators (prostaglandin E2 [PGE2] and tumor necrosis factor alpha [TNFalpha]), to active infection with Salmonella typhimurium. Eighteen crossbred barrows were penned individually with ad libitum access to feed and water. After an acclimation period, jugular catheters were placed in all animals. Control pigs received sterile broth orally (CON, n = 7), whereas the treated pigs (S.TYP, n = 11) received 3 x 10(9) cfu of S. typhimurium orally. Plasma was collected at 6-h intervals from -48 to 120 h. Body weights, feed intake, and rectal temperatures also were monitored. Rectal temperatures were elevated in S.TYP pigs (P < .01) relative to CON pigs by 12 h, peaked at 42 h (P < .001), and remained elevated throughout the remainder of the study. Feed intake was reduced maximally in S.TYP pigs at 48 h (P < .001) and remained reduced through 120 h after the challenge. Daily body weight gain also was reduced during the 2 wk following infection (P < .001). Plasma cortisol concentrations increased (P < .05) at 18 h after the challenge in S.TYP pigs and remained elevated generally until 60 h after infection. A marked suppression of plasma IGF-I occurred in S.TYP pigs beginning at 30 h after infection (P < .001), and it remained lower through 108 h. Plasma GH was not affected consistently by treatment, nor did infection alter plasma TNFalpha and PGE2. Taken together, the results reveal that infectious processes produce profound alterations in the endocrine stress and the somatotropic axis, and this may occur in the absence of significant changes in systemic proinflammatory mediators.

Monitoring of behavior using a video-recording system for recognition of Salmonella infection in experimentally infected growing pigs

“…Our results revealed that oral exposure to S. Typhimurium and S. Enteritidis led to an~10% reduction in growth, which was likely explained by a reduction in feed intake (4% by S. Typhimurium group and 11% by S. Enteritidis group) as the level of feed intake is a basic and important factor that determines the rate of growth and body composition achieved by animals during their lifecycles (Richards, 2003). This observation is in agreement with those of previous studies by Balaji et al (2000), Turner et al (2002) and Burkey et al (2004) who reported lower feed intake and growth rate in pigs orally challenged with S. Typhimurium. However, to the best of our knowledge, no other studies of the effect of oral infection with S. Enteritidis on the growth performance of pigs have been conducted to date.…”

“…We did not observe any changes in body temperature of the infected pigs, which was supported by the results reported by Rostagno et al (2011), who concluded that infection with S. Typhimurium did not lead to development of any clinical symptoms in finishing pigs. In contrast, Balaji et al (2000) reported higher body temperature in weaned pigs orally infected with 3 × 10 9 cfu S. Typhimurium. A possible explanation for this may be that infection with very large numbers of Salmonella is required to initiate clinical disease (i.e.…”

Oral inoculation with Salmonella enterica serovar Typhimurium or Choleraesuis promotes divergent responses in the somatotropic growth axis of swine1

“…In swine, oral infection by Salmonella enterica serovar Typhimurium (hereafter referred to as Typhimurium) results in growth suppression and an array of associated physiological effects (Schwartz, Oral inoculation with Salmonella enterica serovar Typhimurium or Choleraesuis promotes divergent responses in the somatotropic growth axis of swine Balaji et al, 2000;Jenkins et al, 2004). Infection by Salmonella enterica serovar Choleraesuis (hereafter referred to as Choleraesuis), another important swine pathogen, is more likely to cause septicemia in growing pigs (Schwartz, 1999), but little has been reported comparing these 2 serovars in terms of their effects on key regulatory elements of the endocrine growth axis.…”

Early cytokine response of gnotobiotic piglets to Salmonella enterica serotype Typhimurium

“…One of the possible explanations could be its very fast turnover as described by Jesmock et al [11] in E. coli-infected pigs. Balaji et al [4] found increased serum TNF-α levels in pigs 6 h and later after inoculation of ST. However, the lack of plasma TNF-α was described in septicemic calves [23], mice [14] and weaned pigs infected with ST [25].…”