A randomized, double-blind, placebo-controlled phase I clinical trial of rotavirus inactivated vaccine (Vero cell) in a healthy adult population aged 18-49 years to assess safety and preliminary observation of immunogenicity.

We conducted a phase I, randomized, double-blind, placebo-controlled trial including healthy adults in Sui County, Henan Province, China. Ninety-six adults were randomly assigned to one of three groups (high-dose, medium-dose, and low-dose) at a 3:1 ratio to receive one vaccine dose or placebo. Adverse events up to 28 days after each dose and serious adverse events up to 6 months after all doses were reported. Geometric mean titers and seroconversion rates were measured for anti-rotavirus neutralizing antibodies using microneutralization tests. The rates of total adverse events in the placebo group, low-dose group, medium-dose group, and high-dose group were 29.17 % (12.62 %-51.09 %), 12.50 % (2.66 %-32.36 %), 50.00 % (29.12 %-70.88 %), and 41.67 % (22.11 %-63.36 %), respectively, with no significant difference in the experimental groups compared with the placebo group. The results of the neutralizing antibody assay showed that in the adult group, the neutralizing antibody geometric mean titer at 28 days after full immunization in the low-dose group was 583.01 (95 % confidence interval [CI]: 447.12-760.20), that in the medium-dose group was 899.34 (95 % CI: 601.73-1344.14), and that in the high-dose group was 1055.24 (95 % CI: 876.28-1270.75). The GMT of serum-specific IgG at 28 days after full immunization in the low-dose group was 3444.26 (95 % CI: 2292.35-5175.02), that in the medium-dose group was 6888.55 (95 % CI: 4426.67-10719.6), and that in the high-dose group was 7511.99 (95 % CI: 3988.27-14149.0). The GMT of serum-specific IgA at 28 days after full immunization in the low-dose group was 2332.14 (95 % CI: 1538.82-3534.45), that in the medium-dose group was 4800.98 (95 % CI: 2986.64-7717.50), and that in the high-dose group was 3204.30 (95 % CI: 2175.66-4719.27). In terms of safety, adverse events were mainly Grades 1 and 2, indicating that the safety of the vaccine is within the acceptable range in the healthy adult population. Considering the GMT and positive transfer rate of neutralizing antibodies for the main immunogenicity endpoints in the experimental groups, it was initially observed that the high-dose group had higher levels of neutralizing antibodies than the medium- and low-dose groups in adults aged 18-49 years. This novel inactivated rotavirus vaccine was generally well-tolerated in adults, and the vaccine was immunogenic in adults (ClinicalTrials.gov number, NCT04626856).

Neonatal rhesus monkeys as an animal model for rotavirus infection.

AIM: To establish a rotavirus (RV)-induced diarrhea model using RV SA11 in neonatal rhesus monkeys for the study of the pathogenic and immune mechanisms of RV infection and evaluation of candidate vaccines. METHODS: Neonatal rhesus monkeys with an average age of 15-20 d and an average weight of 500 g ± 150 g received intragastric administration of varying doses of SA11 RV ( 107 PFUs/mL, 106 PFUs/mL, or 105 PFUs/mL, 10 mL/animal) to determine whether the SA11 strain can effectively infect these animals by observing their clinical symptoms, fecal shedding of virus antigen by ELISA, distribution of RV antigen in the organs by immunofluorescence, variations of viral RNA load in the organs by qRT-PCR, histopathological changes in the small intestine by HE staining, and apoptosis of small intestinal epithelial cells by TUNEL assay. RESULTS: The RV monkey model showed typical clinical diarrhea symptoms in the 108 PFUs SA11 group, where we observed diarrhea 1-4 d post infection (dpi) and viral antigen shed in the feces from 1-7 dpi. RV was found in jejunal epithelial cells. We observed a viral load of approximately 5.85 × 103 copies per 100 mg in the jejunum at 2 dpi, which was increased to 1.09 × 105 copies per 100 mg at 3 dpi. A relatively high viral load was also seen in mesenteric lymph nodes at 2 dpi and 3 dpi. The following histopathological changes were observed in the small intestine following intragastric administration of SA11 RV: vacuolization, edema, and atrophy. Apoptosis in the jejunal villus epithelium was also detectable at 3 dpi. CONCLUSION: Our results indicate that we have successfully established a RV SA11 strain diarrhea model in neonatal rhesus monkeys. Future studies will elucidate the mechanisms underlying the pathogenesis of RV infection, and we will use the model to evaluate the protective effect of candidate vaccines.

Isolation and characterization of a new candidate human inactivated rotavirus vaccine strain from hospitalized children in Yunnan, China: 2010-2013.

AIM: To determine the distribution of rotavirus VP7 gene in hospitalized children in Yunnan, China. METHODS: A total of 366 stool specimens were collected from hospitalized children in hospitals in Yunnan Province from September 2010 to December 2013. The genomic RNA electropherotypes and the G genotypes of the rotaviruses were determined. A phylogenetic analysis of the VP7 gene was performed. Rotavirus isolation was performed, and characterized by plaque, minimum essential medium, and all genes sequence analysis. Quantification of antibodies for inactivated vaccine prepared with ZTR-68 was examined by enzyme-linked immunosorbent assay and microneutralization assay. RESULTS: Group A human rotavirus was detected in 177 of 366 (48.4%) stool samples using a colloidal gold device assay. The temporal distribution of rotavirus cases showed significant correlation with the mean air temperature. Rotaviruses were isolated from 13% of the rotavirus-positive samples. The predominant genotype was G1 (43.5%), followed by G3 (21.7%), G9 (17.4%), G2 (4.3%), G4 (8.7%), and mixed (4.3%) among a total of 23 rotavirus isolates. A rotavirus strain was isolated from a rotavirus-positive stool sample of a 4-month-old child in The First People's Hospital of Zhaotong (2010) for use as a candidate human inactivated rotavirus vaccine strain and for further research, and was designated ZTR-68. The genotype of 11 gene segments of strain ZTR-68 (RVA/Human-wt/CHN/ZTR-68/2010/G1P[8]) was characterized. The genotype constellation of strain ZTR-68 was identified as G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. The VP7 and VP4 genotypes of strain ZTR-68 were similar to Wa-like strains.CONCLUSIONSA high prevalence of the G1, G2, and G3 genotypes was detected from 2010 to 2012. However, a dominant prevalence of the G9 genotype was identified as the cause of gastroenteritis in children in Yunnan, China, in 2013. A candidate human inactivated rotavirus vaccine strain, designated ZTR-68 was isolated, characterized, and showed immunogenicity. Our data will be useful for the future formulation and development of a vaccine in China.

Biogeography of Nocardiopsis strains from hypersaline environments of Yunnan and Xinjiang Provinces, western China.

The genus Nocardiopsis is a widespread group within the phylum Actinobacteria and has been isolated from various salty environments worldwide. However, little is known about whether biogeography affects Nocardiopsis distribution in various hypersaline environments. Such information is essential for understanding the ecology of Nocardiopsis. Here we analyzed 16S rRNA, gyrB, rpoB and sodA genes of 78 Nocardiopsis strains isolated from hypersaline environments in Yunnan and Xinjiang Provinces of western China. The obtained Nocardiopsis strains were classified into five operational taxonomic units, each comprising location-specific phylo- and genotypes. Statistical analyses showed that spatial distance and environmental factors substantially influenced Nocardiopsis distribution in hypersaline environments: the former had stronger influence at large spatial scales, whereas the latter was more influential at small spatial scales.

Haloactinobacterium album gen. nov., sp. nov., a halophilic actinobacterium, and proposal of Ruaniaceae fam. nov.

A Gram-staining-positive, facultatively anaerobic, non-motile and moderately halophilic actinobacterium, designated YIM 93306(T), was isolated from a salt lake in Xinjiang province, north-west China, and subjected to a polyphasic taxonomic study. Strain YIM 93306(T) grew in the presence of 2-16 % (w/v) NaCl and did not grow without NaCl. The peptidoglycan type was A4alpha with an l-Lys-l-Glu interpeptide bridge. The whole-cell sugars were glucosamine, arabinose, mannose and two unknown sugars. The predominant menaquinone was MK-8(H(4)). The major fatty acids were iso-C(15 : 0), anteiso-C(15 : 0) and anteiso-C(17 : 0). The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown phosphoglycolipid and one unknown phospholipid. The DNA G+C content was 68.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YIM 93306(T) fell within the radius of the suborder Micrococcineae. Its closest phylogenetic neighbour was the type strain of Ruania albidiflava (AS 4.3142(T); 96.2 % 16S rRNA gene sequence similarity), the sole recognized species of the genus Ruania. Sequence similarities between strain YIM 93306(T) and members of other genera of the suborder Micrococcineae were <95.2 %. On the basis of phylogenetic analysis, phenotypic characteristics and chemotaxonomic differences, a novel genus and species, Haloactinobacterium album gen. nov., sp. nov., is proposed. The type strain of the species is YIM 93306(T) (=DSM 21368(T) =KCTC 19413(T) =CCTCC AB 208069(T)). Based on phylogenetic characteristics and 16S rRNA gene signature nucleotide patterns, the genera Ruania and Haloactinobacterium gen. nov. are proposed to belong to a novel family, Ruaniaceae fam. nov.

Yimella lutea gen. nov., sp. nov., a novel actinobacterium of the family Dermacoccaceae.

A Gram-stain-positive, coccoid, non-motile, halotolerant actinobacterium, designated YIM 45900(T), was found as a contaminant on an agar plate in the laboratory of Yunnan Institute of Microbiology, China. The peptidoglycan type was A4alpha with an (L)-Lys-(L)-Ser-(D)-Asp interpeptide bridge. The cell-wall sugars contained galactose and fucose. The predominant menaquinone was MK-8(H(4)). The major fatty acids were iso-C(15 : 0), anteiso-C(15 : 0) and anteiso-C(17 : 0). The polar lipids contained diphosphatidylglycerol, phosphatidylinositol, a glucosamine-containing phospholipid and an unknown phospholipid. The DNA G+C content was 65.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the organism falls within the radius of the suborder Micrococcineae and its closest phylogenetic neighbours are the genera of the family Dermacoccaceae. Strain YIM 45900(T) showed 16S rRNA gene sequences similarity values of 93.1-95.9 % with members of the genera Dermacoccus, Demetria and Kytococcus. On the basis of the phylogenetic and phenotypic characteristics of the actinobacterium, a novel genus and species, Yimella lutea gen. nov., sp. nov., are proposed. The type strain of Yimella lutea is YIM 45900(T) (=DSM 19828(T) =KCTC 19231(T) =CCTCC AB 207007(T)).

Saccharopolyspora qijiaojingensis sp. nov., a halophilic actinomycete isolated from a salt lake.

A halophilic actinomycete strain, designated YIM 91168T, was isolated from a salt lake in Xinjiang province, north-west China. The isolate grew at 20-40 degrees C, pH 5-8 and 6-22% (w/v) NaCl; there was no growth in the absence of NaCl. The whole-cell hydrolysate contained meso-diaminopimelic acid, galactose and arabinose. The major fatty acids were iso-C15:0, iso-C16:0 and iso-C17:0. MK-9(H4) was the predominant menaquinone and the genomic DNA G+C content was 70.1 mol%. These chemotaxonomic data, together with its morphological properties, were consistent with the assignment of strain YIM 91168T to the genus Saccharopolyspora. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YIM 91168T had highest sequence similarity (95.4%) with Saccharopolyspora gregorii NCIB 12823T, and showed lower 16S rRNA gene sequence similarity (93.0-95.1%) with the other species of the genus Saccharopolyspora. On the basis of evidence from this polyphasic study, the novel species Saccharopolyspora qijiaojingensis sp. nov. is proposed. The type strain is YIM 91168T (=DSM 45088T=KCTC 19235T).

Actinopolymorpha alba sp. nov., isolated from a rhizosphere soil.

A Gram-positive, milk-white coloured, aerobic strain, YIM 48868T, was isolated from the rhizosphere soil of Maytenus hookeri Loes in Xishuangbanna, China. 16S rRNA gene sequence similarity studies showed that strain YIM 48868T was a member of the genus Actinopolymorpha, showing 96.8% sequence similarity to Actinopolymorpha singaporensis IM 7744T and 97.0% similarity to Actinopolymorpha rutila YIM 45725T. Chemotaxonomic data (peptidoglycan type I, ll-diaminopimelic acid; sugar pattern C, glucose, rhamnose and ribose; polar lipids PI, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol mannosides and phosphatidylinositol) were characteristic of the genus Actinopolymorpha. A phylogenetic tree based on 16S rRNA gene sequences showed that strain YIM 48868T formed a distinct phylogenetic lineage within the genus Actinopolymorpha. Strain YIM 48868T could be differentiated from recognized species by means of phenotypic properties and the predominant menaquinones [MK-9(H6), MK-9(H8), MK-10(H6), MK-10(H8)]. The DNA G+C content was 66.6 mol%. The DNA-DNA relatedness values between strain YIM 48868T and the type strains of A. singaporensis and A. rutila were 48.7% and 53.1%, respectively. These data, in combination with phenotypic and chemotaxonomic data, demonstrate that strain YIM 48868T represents a novel species in the genus Actinopolymorpha, for which the name Actinopolymorpha alba sp. nov. is proposed. The type strain is YIM 48868T (=CCTCC AA 208030T=DSM 45243T).

Prauserella salsuginis sp. nov., Prauserella flava sp. nov., Prauserella aidingensis sp. nov. and Prauserella sediminis sp. nov., isolated from a salt lake.

Strains YIM 90625(T), YIM 90630(T), YIM 90636(T) and YIM 90694(T) were isolated from a salt lake in Xinjiang province, north-west China, and were subjected to a polyphasic analysis to determine their taxonomic positions. All isolates were moderately halophilic and were able to grow at NaCl concentrations up to 15 or 20 % (w/v). The genomic DNA G+C contents of the strains ranged from 69.1 to 70.1 mol%. Based on the results of 16S rRNA gene sequence analysis, DNA-DNA relatedness, phenotypic characteristics and chemotaxonomic data, the isolates are proposed to represent four novel species of the genus Prauserella for which the names Prauserella salsuginis sp. nov. (type strain YIM 90625(T)=CCTCC AA 208051(T)=DSM 45264(T)), Prauserella flava sp. nov. (type strain YIM 90630(T)=CCTCC AA 208052(T)=DSM 45265(T)), Prauserella aidingensis sp. nov. (type strain YIM 90636(T)=CCTCC AA 208053(T)=DSM 45266(T)) and Prauserella sediminis sp. nov. (type strain YIM 90694(T)=CCTCC AA 208054(T)=DSM 45267(T)).

Haloglycomyces albus gen. nov., sp. nov., a halophilic, filamentous actinomycete of the family Glycomycetaceae.

A novel halophilic actinobacterium, designated YIM 92370(T), was isolated from a hypersaline habitat in Xinjiang Province, north-west China. The strain was aerobic, Gram-positive-staining and halophilic, with an optimum NaCl concentration for growth of 8-12 % (w/v). The whole-cell sugar pattern consisted of ribose, xylose and glucose. The predominant menaquinone was MK-9(H(4)) and the major fatty acids were iso-C(16 : 0), iso-C(17 : 0) and anteiso-C(17 : 0). The phospholipid pattern consisted of phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides, two unknown phosphoglycolipids and one unknown phospholipid. The G+C content of the genomic DNA was 60.8 mol%. Phylogenetic analysis showed that strain YIM 92370(T) can be distinguished from representatives of Glycomyces and Stackebrandtia, the two existing genera in the family Glycomycetaceae, by low 16S rRNA gene sequence similarities (<93.7 %). Strain YIM 92370(T) therefore represents a novel genus and species of the family Glycomycetaceae, for which the name Haloglycomyces albus gen. nov., sp. nov. is proposed. The type strain of Haloglycomyces albus is YIM 92370(T) (=DSM 45210(T) =KCTC 19481(T)).

Haloactinospora alba gen. nov., sp. nov., a halophilic filamentous actinomycete of the family Nocardiopsaceae.

A novel halophilic, filamentous, actinomycete strain, designated YIM 90648(T), was isolated from a salt lake in Xinjiang Province, north-west China, and subjected to a polyphasic taxonomic study. Optimal growth occurred at 37 degrees C, pH 7.0-8.0 and 15% (w/v) NaCl. The aerial mycelium of strain YIM 90648(T) formed long chains of spores at maturity and the spores were cylindrical with smooth surfaces. Spore chains with pseudosporangia at the end were borne on the substrate mycelium and most spores had wrinkled surfaces. Strain YIM 90648(T) contained meso-diaminopimelic acid as the diagnostic diamino acid and galactose and ribose as the major whole-cell components. The phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and phosphatidylinositol mannoside. MK-10(H(8)), MK-11(H(4)), MK-11(H(6)) and MK-11(H(8)) were the predominant menaquinones. The major fatty acids were i-C(16:0) and ai-C(17:0). The DNA G+C content was 68 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YIM 90648(T) formed a distinct lineage within the family Nocardiopsaceae and showed 16S rRNA gene sequence similarity of 93.3-95.0% with members of the family Nocardiopsaceae. On the basis of the polyphasic evidence, a novel genus and species, Haloactinospora alba gen. nov., sp. nov., is proposed to accommodate this isolate. The type strain of Haloactinospora alba is YIM 90648(T) (=DSM 45015(T) =CCTCC AA 206008(T)).

Multiplex specific PCR for identification of the genera Actinopolyspora and Streptomonospora, two groups of strictly halophilic filamentous actinomycetes.

The genera Actinopolyspora and Streptomonospora are two groups of extremely halophilic filamentous actinomycetes. Members of these two genera are isolated frequently, probably due to the high occurrence of these actinomycetes in the hypersaline soil environment. Although members of these genera can be identified by micromorphological criteria, the extensive chemotaxonomic characterization of each new isolates is a time-consuming task which cannot always be undertaken when handling large numbers of isolates as is the case in natural products screening programmes. In this work, the design of one set of genus-specific PCR primers which allows rapid detection of members of the genus Actinopolyspora by means of PCR amplification is presented. And we developed a multiplex PCR protocol for identification of the species of the genera Actinopolyspora and Streptomonospora, simultaneously.