Transmission of F4+ E. coli in groups of early weaned piglets

Abstract

SUMMARYThe aim of this study was to estimate transmission parameters of enterotoxigenic F4+ Escherichia coli F4 (F4+ E. coli) in groups of early weaned piglets with F4-receptor-positive (F4R+) and F4-receptor-negative piglets (F4Rx). Transmission of F4+ E. coli was quantified in four heterogeneous groups of F4R+ and F4Rx piglets. Infectiousness was determined by the number of F4+ E. coli/g faeces shed during 8 days. Transmission parameters were estimated using generalized linear models assuming a stochastic SIR model. F4R+ piglets were found to be more susceptible than F4Rx piglets, but F4R+ and F4Rx piglets were not different in infectiousness. The reproduction ratios for homogeneous F4R+ and F4Rx populations were estimated as 6 . 37 (95 % CI 1 . 89-21 . 48) and 0 . 02 (95 % CI 0 . 00-1 . 13) respectively. The implication of these results is that in order to prevent major outbreaks, the fraction of F4R+ piglets should be small (approximately 10 % or less). Therefore, selective breeding programmes could contribute to reducing F4+ E. coli-related diarrhoea and transmission.

Association between transmission rate and disease severity for Actinobacillus pleuropneumoniae infection in pigs

“…Variation in infectivity between individuals has shown to be of importance for the course of an epidemic [1-3] and can be associated with variation in clinical signs [4-6]. For some diseases, effective control measures should therefore target the severely diseased individual to reduce the size of an outbreak [7].…”

Early transcriptional response in the jejunum of germ-free piglets after oral infection with virulent rotavirus

“…In three of the four infected animals, rotavirus was detected in their feces. Determination of the percent dry matter showed that only the fecal samples collected 18 hpi (piglets 65 and 67) had a significantly lower (pasty) consistency [ 18 ]. This indicated that not all of the piglets developed diarrhea before 12 hpi, and that the two piglets slaughtered 18 hpi did not develop the severe form of diarrhea normally observed at 24 hpi [ 32 ].…”

“… a The consistency of the feces was classified [ 18 ] as normal, unformed or loose, pasty, or fluid, by determining the percent dry matter (% dm). Feces samples were tested for the presence of rotavirus by ELISA [ 33 ].…”

“…Villus and crypt dimensions were determined on hematoxylin-eosin-stained 5-μm tissue sections [ 34 ]. During the experiment, fecal samples were collected at 0, 12 and 18 hpi from the rectum for determination of the percent dry matter [ 18 ]. Fecal samples were tested for the presence or absence of rotavirus by ELISA [ 33 ].…”

Colicin E1 addition to the swine diet prevents post weaning diarrhea

“…Rota virus predisposes the challenged animals to ETEC infection (Melin and Wallgren, 2002;Benfield, et al, 1988;Cox, et al, 1988;Sarmiento et al, 1988;Geenen et al, 2005). While a viral challenge can lower the resistance of the animal to an ETEC infection (this is a likely scenario in the field), doing so adds a confounding effect in studies examining interventions for ETEC caused PWD.…”