Porcine circovirus type 2 (PCV2) and Campylobacter infection induce diarrhea in piglets: Microbial dysbiosis and intestinal disorder

Abstract

Diarrhea is considered to be associated with microbial dysbiosis caused by infection of pathogens but poorly understood. We herein characterized the colonic microbiota of diarrheal early-weaning piglets infected with porcine circovirus type 2 (PCV2) and Campylobacter . Campylobacter infection significantly decreased species richness and Shannon diversity index of colonic microbiota together with a significant increase in the proportion of Campylobacter and Enterobacteriaceae, whereas no significant difference on the above indexes was observed in piglets infected with PCV2 compared with healthy piglets. PCV2 and Campylobacter infection could disturb the homeostasis of colonic microbiota through deterioration of ecological network within microbial community, and specially Campylobacter performed as a module hub in ecological networks. The microbial dysbiosis caused metabolic dysfunction and led to a remarkable reduction in production of short chain fatty acids, following by a higher pH level in colon cavity. Campylobacter infection disturbed the function of colonic tract barrier observed in terms of significant lower relative expression of claudin-1, occluding, and zonula occludens protein-1 genes, and PCV2 infection induced intestinal inflammation together with a higher permeability of colon. Generally, these results suggested that PCV2 and Campylobacter infection could induce microbial dysbiosis and metabolic dysfunction, and cause intestinal disorder, all of which finally were associated to contribute to the diarrhea of early-weaning piglets.

Pathogenic ecological characteristics of PCV2 in large-scale pig farms in China affected by African swine fever in the surroundings from 2018 to 2021

“…In addition, a high positive rate also was observed in immune organs such as the liver, spleen, and lymph nodes, which is associated with the frequent invasion of immune organs by PCV2 ( Shi et al, 2021 ), and viremia may occur in severe cases ( Correa-Fiz et al, 2020 ; Lopez-Lorenzo et al, 2021 ). PCV2 also was detected in the intestines and stomach, which is indicative of gastrointestinal infection with circovirus, and agrees with recent reports ( Liu et al, 2019 ; Yang et al, 2020 ). The relatively high positive rate observed in the coronary sulcus tissues is basically identical to clinical observations, which helps provide evidence of sudden unexplained death in some pigs ( Mikami et al, 2005 ).…”

Pathogenic Ecological Characteristics of PCV2 in Large-Scale Pig Farms in China Affected by African Swine Fever from 2018-2021

“…In addition, the high positive rate also was revealed in immune organs such as the liver, spleen, and lymph nodes, which is associated with the frequent invasion of immune organs by PCV2 (Shi, Hou, & Liu, 2021), and viremia may occur in severe cases (Correa-Fiz et al, 2020;Lopez-Lorenzo et al, 2021). PCV2 also was detected in the intestines and stomach, which is indicative of gastrointestinal infection with circovirus, and agrees with recent reports (G. P. Liu et al, 2019;Yang et al, 2020). The relatively high positive rate observed in the coronary sulcus tissues is basically identical to that in clinics, which helps provide evidence of sudden unexplained death in some pigs (Mikami, Nakajima, Kawashima, Yoshii, & Nakajima, 2005).…”

Disinfection of Maternal Environments Is Associated with Piglet Microbiome Composition from Birth to Weaning

“…Several other indicator genera for piglet gut microbiomes varied between farrowing environments. The abundances of native swine gut commensals such as Prevotella and Phascolarctobacterium ( 22 ) fluctuated in both groups across the 4 time points, while taxa with potential pathogenic or antibiotic resistance roles, such as Enterococcus ( 23 ) and Campylobacter ( 24 ), distinguished pigs born in the disinfected farrowing environment at specific time points (day 0 and day 14, for example, in Fig. 4c ).…”

“…However, the reasons behind the enrichment of Lactobacillus in pigs born in nondisinfected environments warrant further exploration. Piglets born in the nondisinfected environment also harbored lower abundances of potentially pathogenic bacteria such as Enterococcus ( 23 ) and Campylobacter ( 24 ) at days 0 and 14 ( Fig. 4c ).…”