Prevalence of enteric pathogens in diarrheic and non-diarrheic samples from pig farms with neonatal diarrhea in the North East of Spain

Abstract

Diarrhea is one of the major causes of neonatal mortality in pigs. In the present study, 31 pig farms with outbreaks of neonatal diarrhea were investigated in Catalonia (NE Spain) from February 2017 until June 2018. Two hundred and fifteen diarrheic samples from 1 to 7 days old piglets were tested for a panel of enteric pathogens. In 19 of the studied farms additional fecal samples from apparently healthy pen-mates were collected and tested for the same panel of infectious agents. Samples were bacteriologically cultured and tested by PCR for E. coli virulence factors genes, C. perfringens types A and C toxins (Cpα, Cpβ, Cpβ2) and C. difficile toxins (TcdA, TcdB). Moreover, Rotavirus A (RVA), Rotavirus B (RVB), Rotavirus C (RVC), porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) were also determined by RT-qPCR. More than one pathogen could be detected in all of the outbreaks. Nevertheless, RVA was the only agent that could be statistically correlated with the outcome of diarrhea. For the other viruses and bacteria analyzed significant differences between the diseased pigs and the controls were not found. In spite of this, the individual analysis of each of the studied farms indicated that other agents such as RVB, RVC, toxigenic C. difficile or pathogenic E. coli could play a relevant role in the outbreak of diarrhea. In conclusion, the large diversity of agent combinations and disease situations detected in neonatal diarrhea outbreaks of this study stand for a more personalized diagnosis and management advice at a farm level.

Keywords: Bacterial enteric pathogens; Coronavirus; Neonatal diarrhea; Pigs; Rotavirus.

Fig. 1

Proportion of positive samples for each analyzed farms (n = 31) and enteric pathogens by Boxplot. RVA/B/C, rotavirus A/B/C; PCoV, porcine coronaviruses (PEDV and TGEV); TcdA/B, C. difficile toxins; Cpα/β2, C. perfringens toxins; ETEC, enterotoxigenic E. coli; EPEC, enteropathogenic E. coli; VTEC, verotoxigenic E. coli. The distribution of data is displayed as follows: the box is determined by the Interquartile Range (IQR: 25th and 75th percentiles) and the median line shows the middle value of the dataset; the whiskers are determined by the 5th and 95th percentiles; minimum and maximum values are shown at the ends of the bars and outliers as gray dots.

Fig. 2

Comparison of prevalence of positive samples between diarrheic (D, black bar) and non-diarrheic groups (ND, light bar) distributed by farms (Fn) and enteric pathogens. RVA/B/C, rotavirus A/B/C; PCoV, porcine coronaviruses (PEDV and TGEV); TcdA/B, C. difficile toxins; Cpα/β2, C. perfringens toxins; ETEC, enterotoxigenic E. coli; EPEC, enteropathogenic E. coli; VTEC, verotoxigenic E. coli.

Fig. 2

Comparison of prevalence of positive samples between diarrheic (D, black bar) and non-diarrheic groups (ND, light bar) distributed by farms (Fn) and enteric pathogens. RVA/B/C, rotavirus A/B/C; PCoV, porcine coronaviruses (PEDV and TGEV); TcdA/B, C. difficile toxins; Cpα/β2, C. perfringens toxins; ETEC, enterotoxigenic E. coli; EPEC, enteropathogenic E. coli; VTEC, verotoxigenic E. coli.

Fig. 2

Comparison of prevalence of positive samples between diarrheic (D, black bar) and non-diarrheic groups (ND, light bar) distributed by farms (Fn) and enteric pathogens. RVA/B/C, rotavirus A/B/C; PCoV, porcine coronaviruses (PEDV and TGEV); TcdA/B, C. difficile toxins; Cpα/β2, C. perfringens toxins; ETEC, enterotoxigenic E. coli; EPEC, enteropathogenic E. coli; VTEC, verotoxigenic E. coli.