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Given that probiotics always have host-homologous and strain-specific effects on the hosts, lactic acid bacteria extracted and identified from porcine specimens can be potentially developed as probiotics for pig production. We aimed to identify lactic acid bacteria that are potentially probiotic, have good capacity of inhibiting pathogenic bacteria in intestine and are promising to be used as substitutes for antibiotics in pig production. Potential probiotic strains were extracted from 15 fecal specimens collected from 15 apparently healthy pigs, and were identified via 16S rDNA sequencing. The antimicrobial activity, tolerance to acid and bile salts, Caco-2 cell adhesiveness and susceptibility to antibiotics of the isolates were evaluated in vitro, and oral toxicity of the isolates were evaluated in mice. One Lactiplantibacillus plantarum (BJR2), two Lacticaseibacillus casei (HJD and TH2), one Lacticaseibacillus rhamnosus (MRS1), and two Enterococcus faecium (S-3 and S-4-H) were extracted from healthy pigs and underwent 16S rDNA sequencing identification. L. plantarum BJR2 and L. casei HJD exhibited broad spectrum and higher antimicrobial activity against indicator enteric pathogens, including Salmonella choleraesuis CVCC 2139, Escherichia coli (O147:K89) CVCC 199, Escherichia coli (O141:K99) CVCC 223 and Escherichia coli (O139) CVCC 1496, among 6 tested strains. In addition, both L. plantarum BJR2 and L. casei HJD exhibited good tolerance to low pH (pH 2.5 and pH 3.5) and 0.30% bile salts, had relatively strong Caco-2 adhesiveness and carried no transferable resistant genes against antibiotics encoded by plasmid. In safety trials, these two isolates had no α or β-hemolysis activity, and were proved safe through oral toxicity tests in mice. It is concluded that L. plantarum BJR2 and L. casei HJD are potential probiotic candidate strains and their probiotic effects need to be further studied in pigs. [ABSTRACT FROM AUTHOR]

Bama miniature pig (BM) as the inbreed pigs is considered to be a potential donor for xenotransplantation. However, porcine endogenous retrovirus (PERV) integrated in pig's genome, is likely to infect human cells in vitro. PERV infection from BM remains unknown. This study aimed to investigate PERV infection in BM in comparison with that of PK15 cells and further to identify the integration sites of PERV from BM (PERV-BM) in human genome. Two full-length PERV-BMs were cloned from 15 isolates of PERV from Bama miniature pigs and sequence analysis indicated that PERV-BM had limited infection to human cells. Subsequently, PBMC from the BM and PK15 cells were co-cultured with HEK293 cells, respectively. Using nested RT-PCR assay and TEM observation, one PERV-BM was observed to infect HEK293 cells with lower transcriptional level than PERV from PK15 cells (PERV-PK) did, while the others showed no sign of transmission of PERV to human cells. Furthermore, 4 and 157 integration sites were identified from PERV-BM-infected HEK293 cells (HEK293-PERV-BM) and PERV-PK- infected HEK293 cells (HEK293-PERV-PK), respectively, which displayed variations of PERV integration. For further verification of the PERV-BM integration, the expression level of cyclin D1, c-myc, p53 and p16 genes of HEK293-PERV-BM decreased significantly while the CDK4 genes were upregulated dramatically in comparison with those of the HEK293-PERV-PK. It is the first time that PERV-BM has been confirmed to be low infection to human cells and highly integration into the PK15 cells. Therefore, BM is a potential xenograft donor due to less PERV transmission to human beings. [ABSTRACT FROM AUTHOR]

Bats are natural reservoirs for many pathogenic viruses, and increasing evidence supports the notion that bats can also harbor group A rotaviruses (RVAs), important causative agents of diarrhea in children and young animals. Currently, 8 RVA strains possessing completely novel genotype constellations or genotypes possibly originating from other mammals have been identified from African and Chinese bats. However, all the data were mainly based on detection of RVA RNA, present only during acute infections, which does not permit assessment of the true exposure of a bat population to RVA. To systematically investigate the genetic diversity of RVAs, 547 bat anal swabs or gut samples along with 448 bat sera were collected from five South Chinese provinces. Specific reverse transcription-PCR (RT-PCR) screening found four RVA strains. Strain GLRL1 possessed a completely novel genotype constellation, whereas the other three possessed a constellation consistent with the MSLH14-like genotype, a newly characterized group of viruses widely prevalent in Chinese insectivorous bats. Among the latter, strain LZHP2 provided strong evidence of crossspecies transmission of RVAs from bats to humans, whereas strains YSSK5 and BSTM70 were likely reassortants between typical MSLH14-like RVAs and human RVAs. RVA-specific antibodies were detected in 10.7% (48/448) of bat sera by an indirect immunofluorescence assay (IIFA). Bats in Guangxi and Yunnan had a higher RVA-specific antibody prevalence than those from Fujian and Zhejiang provinces. These observations provide evidence for cross-species transmission of MSLH14-like bat RVAs to humans, highlighting the impact of bats as reservoirs of RVAs on public health. IMPORTANCE Bat viruses, such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), Ebola, Hendra, and Nipah viruses, are important pathogens causing outbreaks of severe emerging infectious diseases. However, little is known about bat viruses capable of causing gastroenteritis in humans, even though 8 group A viruses (RVAs) have been identified from bats so far. In this study, another 4 RVA strains were identified, with one providing strong evidence for zoonotic transmission from bats to humans. Serological investigation has also indicated that RVA infection in bats is far more prevalent than expected based on the detection of viral RNA. [ABSTRACT FROM AUTHOR]