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This study reported a new HIV-1 circulating recombinant form CRF65_cpx virus isolated from a man who have sex with men (MSM) in Jilin, China. The near full-length genome of this virus was composed of 14 mosaic gene fragments derived from CRF01_AE, subtype B' (Thai B) and subtype C, highly similar to the CRF65_cpx viruses recently identified in Yunnan and Anhui of China. Phylogenetic tree analysis suggested that this CRF65_cpx strain was not generated among MSM in Jilin, but originated in southern regions of China and spread to Jilin by MSM population. The emergence of CRF65_cpx in Jilin indicated HIV-1 epidemic in this area was more and more complicated and the MSM population has become the important source for generation of new recombinant viruses. Real-time surveillance of new HIV-1 infections among MSM population is quite required.

The effect of total organic carbon (TOC) on the prokaryotic community structure in situ has been rarely known. This study aimed to determine the effect of TOC level on the composition and networks of archaeal and bacterial communities in the sediments of Dianchi Lake, one of the most eutrophic lakes in China. Microbial assemblages showed significantly associations with TOC. Moreover, relatively high and low TOC formed taxonomic differences in prokaryotic assemblages. According to the results, the most abundant bacteria across all samples were identified as members of the phyla Proteobacteria, Nitrospirae, Chloroflexi, Firmicutes and Ignavibacteriae. The dominant groups of archaea consisted of Euryarchaeota, Woesearchaeota DHVEG-6, Bathyarchaeota and WSA2. Lastly, the meta-analysis results highlighted that the low TOC (LT) prokaryotic community structure is larger and more complex compared to moderate TOC (MT). On the whole, the prokaryotic community structure is obviously distinct among groups with different TOC levels, and LT communities may interact with each other strongly in the Dianchi Lake sediment. This study can provide more insights into prokaryotic assemblages in eutrophic lake sediment and provide suggestions for the restoration and maintenance of sediment ecosystems.

The current HIV-1 epidemic in China is featured by diverse subtypes and continual emergence of new recombinant viruses. This study identified a novel unique recombinant form (URF), JL16013, among men who have sex with men (MSM) in Jilin, China. The JL16013 virus was different from all known subtypes and set up a distinct branch on the phylogenetic tree. This virus had a CRF01_AE backbone with two subtype B' fragments and one CRF65_cpx fragment inserted into gag, pol, env, and nef regions, suggesting that this novel URF might have originated from the CRF01_AE, subtype B', and CRF65_cpx viruses that were cocirculating in Jilin province. This was the first report of the CRF01_AE/B'/CRF65_cpx recombinant in China. Identification of this URF indicated the severity and complexity of the HIV-1 epidemic among MSM in Jilin province. Timely surveillance of new HIV-1 infections and new recombinants among the MSM population is urgently required.

Background: Explaining microbial consortia in sediments from the perspective of taxon, co-occurrence and function is the key to recover and maintain aquatic ecosystems. Trophic status was widely considered to be an important determinant of the lake sediment microbial community. However, little is known about the effect of a special eutrophic factor gradient on the prokaryotic community structure in situ. Within this context, we explored prokaryotic communities using an intensive field sampling from sediments in the Dianchi Lake, one of the most eutrophic lakes in China. Results: Microbial assemblages was strongly correlated with total organic carbon (TOC). Moreover, relatively high and low TOC shaped taxonomic and functional differences in microbial assemblages. The results identified the most abundant bacteria across all samples as Proteobacteria , Nitrospirae , Chloroflexi , Firmicutes , Ignavibacteriae , Actinobacteria , Bacteroidetes , Acidobacteria , Spiprochaetae and Latescibacteria . The dominant groups of archaea were Euryarchaeota , Woesearchaeota DHVEG-6 , Bathyarchaeota and WSA2 . Low TOC (LT) microbial assemblages displayed a major proportion of functional profiles related to some metabolisms such as carbohydrate metabolism, amino acid metabolism, energy metabolism, nucleotide metabolism and metabolism of cofactors and vitamins, membrane transport. These results illustrated that TOC concentration had obvious influence on the relative abundances of KEGG orthologs . Finally, the meta-analysis results highlight that most of network parameters of the LT community were significantly greater than those of other communities, which suggesting that the LT community was larger and more complex. Conclusion: TOC level might be a key determinant to shape taxonomic and functional construction of communities in Dianchi Lake sediment. LT community tended to establish a larger and more complex co-occurrence, which suggested that they may interact with each other strongly and exchange essential metabolites. Overall, this study could enhance our knowledge of microbial assemblages in eutrophic lake sediment and provide clues for the restoration and maintenance of sediment ecosystems.