Critical amino acid residues and potential N-linked glycosylation sites contribute to circulating recombinant form 01_AE pathogenesis in Northeast China.

OBJECTIVE: The current study aimed to understand epidemiological feature and critical factors associated with pathogenesis of circulating recombinant form (CRF) 01_AE strains in Northeast China. DESIGN: Compared analysis was made between CRF01_AE and non-CRF01_AE samples to understand the pathogenicity features of CRF01_AE. Further analyses between CRF01_AE samples with high or low CD4 cell counts and between samples with different coreceptor usages were done to explore the possible factors correlating to the pathogenesis of CRF01_AE viruses. METHODS: The genotypes of newly identified strains were determined by phylogenetic analyses using Mega 6.06. Coreceptor usage was predicted by Geno2Pheno algorithm. Potential N-linked glycosylation site (PNGS) number was calculated using the online N-glycosite software. The properties of amino acid sequences were analyzed by the online ProtParam tool. RESULTS: CRF01_AE become the main HIV-1 genotype since 2010. Compared with non-CRF01_AE group, the CRF01_AE group showed a higher proportion of samples with CD4 cell count less than 200 cells/µl. Shorter amino acid length, fewer PNGSs and the presence of a basic motif R/KNXT or NR/KT in V4 correlated to a lower CD4 cell count, and existence or coexistence of Thr12, Arg13, Val21 and Lys33, presence of more than 4 of net charges and lack of the PNGS within V3 favored to the X4/R5X4 coreceptor usage of CRF01_AE viruses. CONCLUSION: CRF01_AE has dominated HIV-1 genotype in Northeast China. Infection with CRF01_AE exhibited a fast disease progression, which may be associated with specific amino acid residues and PNGSs in V3 and V4 regions as well as amino acid length of V4 region.

Identification of a New HIV-1 Circulating Recombinant Form CRF65_cpx Strain in Jilin, China.

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.

Identification of a Novel HIV-1 Unique Recombinant Form Comprising CRF01_AE, Subtype B', and CRF65_cpx Among Men Who Have Sex with Men in Jilin, China.

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.

Mongoliibacter ruber gen. nov., sp. nov., a haloalkalitolerant bacterium of the family Cyclobacteriaceae isolated from a haloalkaline lake.

A novel haloalkalitolerant, rod-shaped bacterium, designated strain YIM 4-4T, was isolated from the surface water of the Dugerno lake, a haloalkaline lake in Inner Mongolia. The taxonomy of strain YIM 4-4T was investigated by a polyphasic approach. Strain YIM 4-4T was Gram-stain-negative, strictly aerobic, non-motile and formed red colonies. Optimal growth conditions were 28 °C, pH 8.0-11.0 and 0.5-2 % NaCl. The major respiratory quinone was menaquinone-7 (MK-7). The polar lipid profile was composed predominantly of phosphatidylethanolamine, six unidentified polar lipids, one phospholipid and one aminolipid. The predominant cellular fatty acids (>5 %) were iso-C15 : 0, iso-C17 : 1I/anteiso-C17 : 1B, iso-C16 : 1G, iso-C17 : 0 3-OH, C16 : 1ω7c/C16 : 1ω6c and iso-C16 : 1. The genomic DNA G+C content was 43.0 mol%. 16S rRNA gene sequence analysis indicated that the members of the genera Cecembia, Fontibacter, Aquiflexum and Indibacter of the family Cyclobacteriaceae (phylum Bacteroidetes) were the most closely related, with 16S rRNA gene sequence similarities ranging from 93.6 to 94.2 %. Other members of the family Cyclobacteriaceae showed sequence similarities < 93.0 %. On the basis of phenotypic, chemotaxonomic and phylogenetic properties, strain YIM 4-4T represents a novel species of a new genus, for which the name Mongoliibacter ruber gen. nov., sp. nov. is proposed. The type strain is YIM 4-4T ( = CCTCC AB 2012966T = DSM 27929T).