The Colostrum-Deprived, Artificially Reared Neonatal Pig as a Model Animal for Studying Rotavirus Gastroenteritis

Gómez, García

doi:10.1080/15513819809168791

Cited by 3 publications

(3 citation statements)

References 60 publications

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“…The piglets were fed a commercial pig milk replacer d based on a previously described regimen. 7 Intervals between feeding and observations of the piglets were never longer than 4 hr. The piglets were handled in accordance with the guidelines set forward in The Guide to the Care and Use of Experimental Animals of the Canadian Council on Animal Care.…”

Section: Methodsmentioning

confidence: 98%

In Vivo and in Vitro Colonization Patterns of AIDA-I–Positive Escherichia Coli Isolates from Piglets with Diarrhea

Pritchard¹,

Ngeleka

Middleton³

2004

J VET Diagn Invest

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Abstract. Transmission electron microscopy (TEM) was used to characterize the colonization patterns of 3 pathogenic Escherichia coli strains: PD58 and PD149 of the AIDA-I/STb/EAST1 pathotype, serogroup O: ND (not determined), and PD31 of the LT/STb/EAST1 pathotype, serogroup O149. These strains were isolated from diseased piglets and caused diarrhea in experimentally inoculated, newborn, colostrum-deprived pigs. In this study, intestinal tissues from newborn pigs experimentally infected with a high inoculum (20 ml containing 10 10 cfu) were harvested and examined for bacterial colonization using light microscopy. A nonaqueous perfluorocarbon fixation method was used to preserve the glycocalyx of the microvillus border in tissues collected for TEM. Transmission electron micrographs revealed that E. coli strain PD149 displayed long flexible fimbrialike structures that intimately attached the bacteria both to the microvillus border of the upper colon and to adjacent bacteria. In vitro, this strain demonstrated the localized adherence pattern to HEp-2 cells characteristic of enteroaggregative E. coli (EAggEC). Both PD58 and PD31 strains colonized the upper colon through the formation of a biofilm, also characteristic of EAggEC. Strains PD58 and PD31 adhered poorly to HEp-2 cells in vitro, although these demonstrated a colonization pattern suggestive of diffuse and aggregative adherence, respectively. These findings suggest that strains PD58 and PD149, expressing the AIDA-I, factor and strain PD31 represents hybrid pathotypes of diarrheagenic E. coli and that they probably cause diarrhea in piglets through differing mechanisms.Diarrhea is one of the most common problems affecting neonatal pig survival worldwide. The highest incidence of clinically relevant diarrhea occurs in the first 3 to 5 days of life, and enterotoxigenic Escherichia coli (ETEC) is the most common agent identified. 1,10,20 Piglets are exposed to massive numbers of bacteria at the time of birth. The majority of these are nonpathogenic anaerobes, but potentially pathogenic E. coli are also present. The pH of the stomach and the duodenum at birth is relatively alkaline and few digestive enzymes are produced, allowing a favorable environment for bacterial growth. 8 Enterotoxigenic E. coli colonize the small intestine of the piglet in the first few hours of life by attaching or tethering to the microvillus border of the enterocytes with one of the ETEC fimbrial factors F4 (K88), F5 (K99), F6 (987P), F18, or F41. 5 The bacteria then produce 1 or more of 3 enterotoxins, heat-labile toxin (LT), heat-stable toxin 'a' (STa), or heat-stable toxin 'b' (STb), which act directly on enterocytes through different pathways to stimulate a net secretory watery diarrhea 8 with accompanying dehydration, electrolyte imbalances, including hyperkalemia, and acidosis. It is the combination of these pathophysiological changes that often results in the death of a piglet.In an increasing number of cases of enteric colibacillosis in piglets, ETEC strains isolated in the bacte...

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Section: Methodsmentioning

confidence: 98%

In Vivo and in Vitro Colonization Patterns of AIDA-I–Positive Escherichia Coli Isolates from Piglets with Diarrhea

Pritchard¹,

Ngeleka

Middleton³

2004

J VET Diagn Invest

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“…Clinical disease may occur in the postweaning period or, less frequently, in the neonatal pig, with the symptoms of diarrhea, vomiting, enterocolitis, and bacteremia (with major organ involvement in more severe infections). Therefore, the young pig is a desirable target for vaccination and is also a good model for human gastroenteritis (20,48).…”

mentioning

confidence: 99%

Rapid Protection of Gnotobiotic Pigs against Experimental Salmonellosis following Induction of Polymorphonuclear Leukocytes by AvirulentSalmonella enterica

Foster¹,

Lovell²,

Marston³

et al. 2003

Infect Immun

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Oral inoculation of 5-day-old gnotobiotic pigs with Salmonella enterica serovar Typhimurium strain F98 resulted in severe enteritis and invasive disease. Preinoculation 24 h earlier with an avirulent mutant of Salmonella enterica serovar Infantis (1326/28) completely prevented disease for up to 14 days (when the experiment was terminated). S. enterica serovar Infantis colonized the alimentary tract well, with high bacterial counts in the intestinal lumen but with almost no invasion into the tissues. Unprotected pigs had high S. enterica serovar Typhimurium counts in the intestines, blood, and major nonintestinal organs. Recovery of this strain from the blood and major organs in S. enterica serovar Infantis-protected pigs was substantially reduced despite the fact that intestinal counts were also very high. Protection against disease thus did not involve a colonization exclusion phenomenon. Significant (P < 0.05) infiltration of monocytes/macrophages was observed in the submucosal regions of the intestines of both S. enterica serovar Infantis-protected S. enterica serovar Typhimurium-challenged pigs and unprotected S. enterica serovar Typhimurium-challenged pigs. However, only polymorphonuclear neutrophils (PMNs) were observed throughout the villus, where significant (P < 0.05) numbers infiltrated the lamina propria and the subnuclear and supranuclear regions of the epithelia, indicating that PMN induction and positioning following S. enterica serovar Infantis inoculation was consistent with rapid protection against the challenge strain. Similarly, in vitro experiments using a human fetal intestinal epithelial cell line (INT 407) demonstrated that, although significantly (P < 0.05) fewer S. enterica serovar Infantis than S. enterica serovar Typhimurium organisms invaded the monolayers, S. enterica serovar Infantis induced an NF-B response and significantly (P < 0.05) raised interleukin 8 levels and transmigration of porcine PMN. The results of this study suggest that attenuated Salmonella strains can protect the immature intestine against clinical salmonellosis by PMN induction. They also demonstrate that PMN induction is not necessarily associated with clinical symptoms and/or intestinal pathology.

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“…In Europe, Salmonella serovar Typhimurium is the serovar that is most frequently isolated from humans or pigs (25), while in the United States it is estimated that up to 4 million cases of salmonellosis occur annually, of which about 500 are fatal (19). Although vaccination of piglets against Salmonella is a desirable target, gnotobiotic piglets have previously been shown to be a useful model of enteric disease in humans (16,20,41). Recently, we showed that oral inoculation of 5-day-old gnotobiotic piglets with a rough lipopolysaccharide (LPS) mutant of S. enterica serovar Infantis 1326/28 (1326/28⌽ r ) protects against a subsequent, normally lethal challenge with Salmonella serovar Typhimurium strain F98 (16).…”

Section: Preinoculation Of Susceptible 5-day-old Gnotobiotic Piglets mentioning

confidence: 99%

Stimulation of gp91 Phagocytic Oxidase and Reactive Oxygen Species in Neutrophils by an AvirulentSalmonella entericaSerovar Infantis Strain Protects Gnotobiotic Piglets from Lethal Challenge with Serovar Typhimurium Strain F98 without Inducing Intestinal Pathology

Foster¹,

Hulme²,

Lovell³

et al. 2005

Infect Immun

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Preinoculation of susceptible 5-day-old gnotobiotic piglets with Salmonella enterica serovar Infantis strain 1326/28⌽ r stimulates neutrophil migration into the intestine, which rapidly protects the pigs against a subsequent (normally lethal) challenge with S. enterica serovar Typhimurium strain F98. Here we show that inoculation with either 1326/28⌽ r or F98 activated reactive oxygen species (ROS) in neutrophils via NADPH pathways in vivo and in vitro and that the survival of both Salmonella strains was increased if neutrophils were cocultured with the ROS inhibitor N-acetylcysteine (captopril). Neither F98 nor 1326/28⌽ r significantly increased reactive nitrogen species (RNS) levels in neutrophils isolated from uninfected pigs. Our results indicate the following: (i) rapid protection of highly susceptible gnotobiotic piglets against F98-induced gastroenteritis by preinoculation with 1326/28⌽ r is likely to be due to stimulation of ROS-producing neutrophils in the intestinal epithelium prior to challenge with the lethal strain; (ii) pathological lesions of the intestine during severe gastroenteritis are not necessarily induced by neutrophil migration per se; and (iii) if neutrophil migration into the intestine is responsible for pathology, then neither increased production of ROS or RNS (in pigs inoculated with the lethal strain) nor reduced production (in protected pigs in which pathological lesions are ameliorated by preinoculation with 1326/28⌽ r ) can account for this phenomenon.

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The Colostrum-Deprived, Artificially Reared Neonatal Pig as a Model Animal for Studying Rotavirus Gastroenteritis

Cited by 3 publications

References 60 publications

In Vivo and in Vitro Colonization Patterns of AIDA-I–Positive Escherichia Coli Isolates from Piglets with Diarrhea

In Vivo and in Vitro Colonization Patterns of AIDA-I–Positive Escherichia Coli Isolates from Piglets with Diarrhea

Rapid Protection of Gnotobiotic Pigs against Experimental Salmonellosis following Induction of Polymorphonuclear Leukocytes by AvirulentSalmonella enterica

Stimulation of gp91 Phagocytic Oxidase and Reactive Oxygen Species in Neutrophils by an AvirulentSalmonella entericaSerovar Infantis Strain Protects Gnotobiotic Piglets from Lethal Challenge with Serovar Typhimurium Strain F98 without Inducing Intestinal Pathology

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