Study Of The Bacterial Diversity In The Gastrointestinal Tracts Of Rhinolophus Luctus And Murina Leucogaster

Bats are a kind of unique mammals with the ability of autonomous flight,which are all over the world,rich in species,and in close contact with human beings.As pollinators,seed carriers and insect predators,bats play an important role in maintaining ecosystem balance.At the same time,bats are considered to be potential reservoirs of zoonotic pathogens,which can cause many kinds of zoonoses and threaten human health.In addition,the rapid development of tourism in China in recent years has led to many bat-occupied caves being exploited as tourist attractions,which not only destroys the living environment for the bats,but also increases the risk of human contact with the bats or their feces and the potential transmission of pathogenic bacteria to humans.Previous studies have assessed the diversity of gastrointestinal bacteria in bats and reported that some of the strains are pathogenic to humans.However,the bacterial diversity and types of pathogenic bacteria in the gastrointestinal tracts of Rhinolophus luctus and Murina leucogaster have not yet been determined.Humans frequently come into contact with these species;therefore,assessments of their gut microbiota,especially potential pathogens,are essential for public health.The present study,therefore,determined the bacterial diversity and the types of pathogenic bacteria in the gastrointestinal tracts of R.luctus and M.leucogaster,using Mi Seq high throughput sequencing technology,which provided basic reference information for future research of pathogenic bacteria in bats,and the results were compared with those reported previously.1.A total of 922,211 original sequences were obtained from the samples of the gastrointestinal flora of R.luctus and M.leucogaster.In total,after chimera removal,660,444 effective sequences wereobtained,with an average of 55,037 sequences per sample.Based on 97% sequence identity,the stomach and intestine samples of R.luctus were clustered into 28 operational taxonomic units(OTUs),respectively.The stomach and intestine samples of M.leucogaster were assigned to 36 and 40 OTUs,respectively.2.The bacteria in the gastrointestinal tract of R.luctus were from three phyla: Proteobacteria,Firmicutes,and Bacteroidetes.The most abundant phylum was Proteobacteria(stomach 86.07%,intestines91.87%),followed by Firmicutes(stomach 13.84%,intestines 8.11%),and the least represented phylum was Bacteroidetes(only intestines 0.02%).The bacteria in the gastrointestinal tract of M.leucogaster were mainly from four phyla: Proteobacteria,Firmicutes,Bacteroidetes,and Actinobacteria.The most abundant phylum was Proteobacteria(stomach 95.79%,intestines 88.78%),followed by Firmicutes(stomach 4.19%,intestines 11.20%),and the least represented phylum was Actinobacteria(only intestines 0.01%).3.In total,7 and 6 bacterial families occurred in a relative abundance of 1% or more in the gastrointestinal tracts of R.luctus and M.leucogaster,respectively.In R.luctus,the dominant families were Enterobacteriaceae(86.02%)and Streptococcaceae(10.11%)in the stomach,and Enterobacteriaceae(59.84%)and Oxalobacteraceae(28.57%)in the intestines.In M.leucogaster,the dominant families were Enterobacteriaceae(stomach 29.87%,intestines 55.32%)and Oxalobacteraceae(stomach 54.41%,intestines 29.67%).4.In total,6 and 5 bacterial genera occurred in a relative abundance of 1% or more in the gastrointestinal tracts of R.luctus and M.leucogaster,respectively.In R.luctus,the dominant genera were Lactococcus(10.11%)and Paeniclostridium(3.41%)in the stomach,and Undibacterium(28.56%)and Paeniclostridium(4.69%)in the intestines.In M.leucogaster,the dominant genera were Undibacterium(54.41%)and Burkholderia(5.28%)in the stomach,and Undibacterium(29.67%)and Enterococcus(7.19%)in the intestines.5.Among the detected gastrointestinal tract flora of R.luctus and M.leucogaster,12 bacterial genera(Lactococcus,Burkholderia,Enterococcus,Paeniclostridium,Citrobacter,Staphylococcus,Actinobacillus,Clostridium?sensu?stricto?1,Acinetobacter,Pseudomonas,Escherichia/Shigella,Sphingomonas)were pathogenic bacteria or opportunistic pathogens,which demonstrates the urgency for increased efforts in the prevention and control of bat-to-human disease transmission from these species.To avoid the occurrence of zoonosis,management departments are urged to adopt scientific and rational methods to create,develop,or restrict access to caves inhabited by bats,to reduce or effectively control opportunities for human-bat interactions.