Gastric Ulceration and Immune Suppression in Weaned Piglets Associated with Feed-Borne Bacillus cereus and Aspergillus fumigatus

Abstract

As a multifactorial cause, gastric ulceration-mediated diarrhea is widely prevalent in the weaned piglets, impairing pig health and economic benefits. With full implementation of antibiotic stewardship programs in China, Bacillus cereus (B. cereus) and Aspergillus fumigatus (A. fumigatus) were identified frequently in porcine feedstuffs and feeds of the animal industry. Association between feed-borne B. cereus and frequent diarrhea remains unclear. In the present study, we conducted a survey of B. cereus and A. fumigatus from feeds and feedstuffs in pig farms during hot season. Interestingly, B. cereus, B. subtilis, B. licheniformis and B. thuringinesis were isolated and identified from piglets’ starter meals to sow feeds, accounting for 56.1%, 23.7%, 13.7% and 6.5%, respectively. Obviously, both B. cereus and B. subtili were dominant contaminants in the survey. In an in vitro study, Deoxynivalenol (DON) contents were determined in a dose-dependent manner post fermentation with B. cereus (405 and DawuC). Subsequently, 36 weaned piglets were randomly assigned to four groups and the piglets simultaneously received the combination of virulent B. cereus (Dawu C) and A. fumigatus while animals were inoculated with B. cereus (Dawu C), A. fumigatus or PBS as the control group. Clinically, piglets developed yellow diarrhea on day 5 and significant reductions of relative body weight were observed in the B. cereus group, and co-infection group. More importantly, IgG titers against Classical swine fever virus (CSFV) and Porcine epidemic diarrhea (PED) were reduced dramatically during 14-day observation in co-infection group, the B. cereus (Dawu C) group or the A. fumigatus group. However, lower Foot and mouth disease (FMD) -specific antibodies were reduced on day 7 compared to those of the control group. Additionally, lower lymphocyte proliferations were found in the B. cereus group and the co-infection group compared to the control group. Postmortem, higher lesions of gastric ulceration were observed in the B. cereus group and the co-infection group from day 7 to day 14 compared with those of the A. fumigatus group and the control group. Compared to the A. fumigatus group, higher DON contents were detected in the stomach inoculated with B. cereus and the co-infection with A. fumigatus. In conclusion, our data support the hypothesis that B. cereus might be associated with severe diarrhea by inducing gastric ulcerations and A. fumigatus might aggravate immune suppression, threating a sustainable swine industry. It is urgently needed to control feed-borne B. cereus contamination.

Coated Zinc Oxide Improves Growth Performance of Weaned Piglets via Gut Microbiota

“…And this trait had drawn much attention to use as microbial nano-factory for metal particle production, which illustrated the booms of the genus in the foregut, whereas B. cereus was strongly inhibited in a similar environment. The intestine of livestock was a natural reservoir for foodborne bacteria, such as B. cereus, which not only caused widely contamination but triggered diarrhea and gastric ulcerations in the piglets, leading to the risk for growth retardation and even death (43,44). Through the antibacterial experiment in vitro, we also found the strong inhibiting effect of S. thermophilus against B. cereus, which also verified the coexclusion effects.…”

Damage to intestinal barrier integrity in piglets caused by porcine reproductive and respiratory syndrome virus infection

“…The intestinal mucosal barrier plays an important role as the first barrier against pathogens in defending against harmful external factors and maintaining intestinal health. Impaired intestinal function caused by pathogens will lead to obstructed nutritional absorption [ 3 ], low immunity [ 4 ], and reduced growth performance of pigs [ 5 – 7 ], causing severe economic losses to the pig industry. Epithelial cells and their tight junctions create a barrier between the external environment and the host.…”

Feed-Borne Bacillus Cereus: An Emerging Threat to Food Chain Related Hazard, Safety and Pathogenic Potentiality

“…cereus and other members of the B. cereus group induce two forms of food poisoning: emetic syndrome and diarrheal illness. The emetic (vomiting) syndrome, which is similar to Staphylococcus aureus poisoning, is exacerbated by a ready toxin found in cooked rice and other cereal-based foods that resist high temperatures, trypsin, pepsin, and pH; whereas the diarrheal illness, which is similar to Clostridium perfringens poisoning, In a recent study, it was found that stomach ulceration caused by feed-borne B. cereus in conjunction with severe diarrhea, and co-infection with Aspergillus fumigatus alleviated gastric lesions and immunosuppression in weaned piglets (Li et al 2020).…”