Increase of respiratory illnesses among children in Beijing, China, during the autumn and winter of 2023.

In 2023, through an ongoing respiratory pathogen surveillance system, we observed from mid-September onwards, an increase of respiratory illness among children aged ≤ 15 years presenting at hospital outpatient clinics in Beijing, China. Data indicated that illness was caused by multiple pathogens, predominantly Mycoplasma pneumoniae. Seasonality, periodicity and high prevalence of resistance to macrolide (30 of 30 strains sequenced with the A2063G mutation) were important characteristics of the M. pneumoniae epidemic, which resulted in a rise in consultations at specialised paediatric hospitals.

Genome sequencing reveals molecular epidemiological characteristics and new recombinations of adenovirus in Beijing, China, 2014-2019.

To investigate the molecular epidemiological characteristics and genetic variations of human adenovirus (HAdV) in acute respiratory tract infections in Beijing. Whole-genome sequencing and phylogenetic analyses were performed for 83 strains of HAdV with different types in Beijing from 2014 to 2019. The clinical characteristics of HAdV infection were analyzed statistically. HAdV-B was divided into four genotypes, including B3 (n = 11), B7 (n = 13), B14 (n = 4), and B55 (n = 2). HAdV-C was divided into three genotypes, including C1 (n = 14), C2 (n = 13), and C5 (n = 10). In HAdV-C, nine recombinant adenovirus strains were identified in type 1, and seven recombinant strains were found in type 2. In type 1, we found three newly emerged intraspecific recombinant strains (A47, A48, and A52) collected in 2017, 2018, and 2019, respectively. In addition, the previously reported recombinant strains of HAdV-C1 showed more severe disease than other strains of HAdV-C, causing severe community-acquired pneumonia in both the elderly and children. Continuous population-wide molecular epidemiological surveillance of HAdV is essential for the prevention and control of respiratory infectious diseases.

Streptomyces polygonati sp. nov., an endophytic actinomycete isolated from a root of Polygonatum odoratum (Mill.).

A novel actinomycete, designated strain NEAU-G9T, was isolated from the root of Polygonatum odoratum (Mill.) collected from Harbin, Heilongjiang province, north China, and was characterized using a polyphasic approach. Key morphological and chemotaxonomic properties confirmed the affiliation of strain NEAU-G9T to the genus Streptomyces. Strain NEAU-G9T contained ll-diaminopimelic acid as the diamino acid. The predominant menaquinones were MK-9(H8), MK-9(H6) and MK-9(H4). The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The predominant fatty acids were iso-C16 : 0, anteiso-C15 : 0 and C16 : 0.16S rRNA gene sequence similarity studies showed that strain NEAU-G9T belongs to the genus Streptomyces and exhibits the highest sequence similarity to Streptomyces yanglinensis JCM 13275T (97.75 %). However, phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-G9T is most closely related to Streptomyces misakiensis JCM 4062T (97.12 % sequence similarity). A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-G9T can be clearly distinguished from S. yanglinensis JCM 13275T and S. misakiensis JCM 4062T. Consequently, strain NEAU-G9T represents a novel species of the genus Streptomyces, for which the name Streptomyces polygonati sp. nov. is proposed. The type strain is NEAU-G9T ( = CGMCC 4.7237T = DSM 100521T).

Nocardia camponoti sp. nov., an actinomycete isolated from the head of an ant (Camponotus japonicas Mayr).

A novel actinomycete, designated strain 1H-HV4T, was isolated from the head of Camponotus japonicas Mayr, which was collected from Northeast Agriculture University (Harbin, Heilongjiang, China). Chemotaxonomic properties of this strain were consistent with those of members of the genus Nocardia. The cell wall contained meso-diaminopimelic acid and whole-cell sugars were galactose, glucose and arabinose. The predominant menaquinone was MK-8(H4,ω-cycl). The phospholipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids were identified as C18:0 10-methyl, C16:0, C18:1ω9c and C16:1ω7c. Mycolic acids were found to be present. 16S rRNA gene sequence analysis also showed that strain 1H-HV4T was a member of the genus Nocardia, with the highest sequence similarities to Nocardia salmonicida JCM 4826T (97.39%), Nocardia soli JCM 11441T (97.12%) and Nocardia cummidelens JCM 11439T (97.08%). 16S rRNA gene sequence similarities to type strains of other members of the genus Nocardia were less than 97%. However, DNA-DNA relatedness values and phenotypic data demonstrated that strain1H-HV4T was clearly distinguished from all closely related species of the genus Nocardia. It is concluded that the isolate can be classified as representing a novel species of the genus Nocardia, for which the name Nocardia camponoti is proposed. The type strain is 1H-HV4T (=DSM 100526T=CGMCC 4.7278T).

Plantactinosporasoyae sp. nov., an endophytic actinomycete isolated from soybean root [Glycine max (L.) Merr].

A novel actinomycete, designated strain NEAU-gxj3T, was isolated from soybean root [Glycine max (L.) Merr.] collected from Harbin, Heilongjiang Province, China, and characterized using a polyphasic approach. The 16S rRNA gene sequence of strain NEAU-gxj3T showed highest similarity to those of Micromonospora equina Y22T (98.2 %) and Plantactinospora endophytica YIM 68255T (98.0 %). Phylogenetic analysis based on the 16S rRNA gene and gyrB gene demonstrated that the isolate clustered with the members of the genus Plantactinospora. The chemotaxonomic properties of strain NEAU-gxj3Twere also consistent with those of members of the genus Plantactinospora. The cell wall contained meso-diaminopimelic acid and whole-cell sugars were xylose, glucose and galactose. The predominant menaquinones were MK-10(H6), MK-9(H8), MK-10(H2) and MK-10(H4). The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major fatty acids were identified as anteiso-C17 : 0, iso-C16 : 0, iso-C15 : 0 and C15 : 0. A combination of DNA-DNA hybridization result and some phenotypic characteristics indicated that strain NEAU-gxj3Tcould be differentiated clearly from its closest phylogenetic relatives. Therefore, the strain is concluded to represent a novel species of the genus Plantactinospora, for which the name Plantactinospora soyae sp. nov. is proposed. The type strain is NEAU-gxj3T (=CGMCC 4.7221T=DSM 46832T).

Lysinibacillus endophyticus sp. nov., an indole-3-acetic acid producing endophytic bacterium isolated from corn root (Zea mays cv. Xinken-5).

A Gram-positive, aerobic, motile, rod-shaped bacterium, designated strain C9(T), was isolated from surface sterilised corn roots (Zea mays cv. Xinken-5) and found to be able to produce indole-3-acetic acid. A polyphasic taxonomic study was carried out to determine the status of strain C9(T). The major cellular fatty acids were found to contain iso-C15:0, anteiso-C15:0 and anteiso-C17:0, and the only menaquinone was identified as MK-7. The polar lipid profile was found to contain diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and an unidentified lipid. The cell wall peptidoglycan was found to be of the A4α L-Lys-D-Asp type and the whole cell sugar was found to be glucose. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain C9(T) belongs to the genus Lysinibacillus and is closely related to Lysinibacillus chungkukjangi NBRC 108948(T) (98.1 % similarity) and Lysinibacillus sinduriensis DSM 27595(T) (98.0 %). However, the low levels of DNA-DNA relatedness and some differential phenotypic characteristics allowed the strain to be distinguished from its close relatives. Therefore, it is concluded that strain C9(T) represents a novel species of the genus Lysinibacillus, for which the name Lysinibacillus endophyticus sp. nov. is proposed. The type strain is C9(T) (=DSM 100506(T) = CGMCC 1.15291(T)).

Catellatospora vulcania sp. nov. and Catellatospora paridis sp. nov., two novel actinobacteria isolated from volcanic sediment and the rhizosphere of Paris polyphylla.

Two novel actinobacteria, designated strains NEAU-JM1(T) and NEAU-CL2(T), were isolated from volcanic sediment and the rhizosphere soil of Paris polyphylla, respectively, collected from Jiling and Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic positions of these strains. The 16S rRNA gene sequence analysis showed that the two novel isolates exhibit 99.5 % 16S rRNA gene sequence similarity with each other. The phylogenetic analysis based on 16S rRNA gene sequence of strain NEAU-JM1(T) showed it to be closely related to Catellatospora methionotrophica JCM 7543(T) (99.4 % sequence similarity), Catellatospora coxensis DSM 44901(T) (99.4 %), Catellatospora citrea DSM 44097(T) (99.3 %) and Catellatospora chokoriensis JCM 12950(T) (99.2 %), and that of strain NEAU-CL2(T) to C. citrea DSM 44097(T) (99.4 %), C. methionotrophica JCM 7543(T) (99.3 %), C. chokoriensis JCM 12950(T) (99.3 %) and C. coxensis DSM 44901(T) (99.2 %). However, the DNA-DNA hybridization value between strains NEAU-JM1(T) and NEAU-CL2(T) was 62.2 %, and the values between the two strains and their close phylogenetic relatives were also below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA-DNA hybridization results, the two strains can be distinguished from each other and their close phylogenetic relatives. Thus, strains NEAU-JM1(T) and NEAU-CL2(T) can be concluded to represent two novel species of the genus Catellatospora, for which the names Catellatospora vulcania sp. nov. and Catellatospora paridis sp. nov. are proposed. The type strains are NEAU-JM1(T) (=CGMCC 4.7174(T) = JCM 30054(T)) and NEAU-CL2(T) (=CGMCC 4.7236(T) = DSM 100519(T)), respectively.

Streptosporangium lutulentum sp. nov., Streptosporangium fenghuangense sp. nov. and Streptosporangium corydalis sp. nov., three novel actinobacterial species isolated from National Forest Park of Fenghuang Mountain.

Three novel actinobacteria, designated strains NEAU-FSHN1(T), NEAU-hd-3(T) and NEAU-Y6(T), were isolated from a stream base, soil adjacent to the stream and a root of Corydalis yanhusuo L, respectively, collected from Wuchang, Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic positions of these strains. The three strains were observed to form scant aerial hyphae that differentiated into spherical spore vesicles. The phylogenetic analysis based on the 16S rRNA gene sequences of strains NEAU-FHSN1(T), NEAU-hd-3(T) and NEAU-Y6(T) showed that the three novel isolates exhibit 99.2 % (NEAU-FHSN1(T)/NEAU-hd-3(T)), 99.2 % (NEAU-FHSN1(T)/NEAU-Y6(T)) and 99.7 % (NEAU-hd-3(T)/NEAU-Y6(T)) 16S rRNA gene sequence similarities with each other and that they are closely related to strains Streptosporangium shengliense NEAU-GH7(T) (sequence similarities 98.72, 98.85, 98.99 %), Streptosporangium roseum DSM 43021(T) (98.65, 98.51, 98.58 %) and Streptosporangium album DSM 43023(T) (98.41, 98.96, 98.89 %). However, the DNA-DNA hybridization values between strains NEAU-FSHN1(T), NEAU-hd-3(T) and NEAU-Y6(T) were 61.2 % (NEAU-FSHN1(T)/NEAU-hd-3(T)), 63.5 % (NEAU-FHSN1(T)/NEAU-Y6(T)) and 65.8 % (NEAU-hd-3(T)/NEAU-Y6(T)), and the values between the three strains and their close phylogenetic relatives were also below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA-DNA hybridization results, the three strains can be distinguished from each other and their close phylogenetic relatives. Thus, strains NEAU-FHSN1(T), NEAU-hd-3(T) and NEAU-Y6(T) are concluded to represent three novel species of the genus Streptosporangium, for which the names Streptosporangium lutulentum sp. nov., Streptosporangium fenghuangense sp. nov. and Streptosporangium corydalis sp. nov. are proposed. The type strains are NEAU-FHSN1(T) (=CGMCC 4.7141(T) = DSM 46740(T)), NEAU-Y6(T) (=CGMCC 4.7150(T) = DSM 46722(T)) and NEAU-hd3(T) (CGMCC 4.7212(T) = JCM 30058(T)), respectively.

Streptomyces songpinggouensis sp. nov., a Novel Actinomycete Isolated from Soil in Sichuan, China.

During a screening for novel and biotechnologically useful actinobacteria, a novel actinobacteria with weak antifungal activity, designated strain NEAU-Spg19T, was isolated from a soil sample collected from pine forest in Songpinggou, Sichuan, southwest China. The strain was characterized using a polyphasic taxonomic approach which confirmed that it belongs to the genus Streptomyces. Growth occurred at a temperature range of 10-30 °C, pH 5.0-11.0 and NaCl concentrations of 0-5 %. The cell wall peptidoglycan consisted of LL-diaminopimelic acid and glycine. The major menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4). The phospholipid profile contained diphosphatidylglycerol (DPG), phosphatidylethanolamine and phosphatidylinositol. The major fatty acids were iso-C15:0, iso-C16:0, and C16:0. 16S rRNA gene sequence similarity studies showed that strain NEAU-Spg19T belongs to the genus Streptomyces with the highest sequence similarities to Streptomyces tauricus JCM 4837T (98.6 %) and Streptomyces rectiviolaceus JCM 9092T (98.3 %). Some physiological and biochemical properties and low DNA-DNA relatedness values enabled the strain to be differentiated from S. tauricus JCM 4837T and S. rectiviolaceus JCM 9092T. Hence, on the basis of phenotypic and genetic analyses, it is proposed that strain NEAU-Spg19T represents a novel species of the genus Streptomyces, for which the name Streptomyces songpinggouensis sp. nov. is proposed. The type strain is NEAU-Spg19T (=CGMCC 4.7140T=DSM 42141T).

Baia soyae gen. nov., sp. nov., a mesophilic representative of the family Thermoactinomycetaceae, isolated from soybean root [Glycine max (L.) Merr].

A mesophilic, endophytic, filamentous bacterium, designated strain NEAU-gxj18T, was isolated from soybean root [Glycine max (L.) Merr.] collected from Harbin, Heilongjiang Province, China and characterized using a polyphasic approach. Growth was observed at 20­40 °C (optimum 37 °C). Aerial mycelium was absent on all the media tested. Substrate mycelia were well-developed and formed abundant single endospores with smooth surfaces. The only menaquinone was MK-7.The diagnostic diamino acid was meso-diaminopimelic acid. The whole-cell sugars were ribose, glucose and galactose. The major fatty acids were iso-C15 : 0, C13 : 0 and iso-C17 : 0. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid and one undientified phospholipid. The DNA G+C content was 49.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-gxj18T was phylogenetically related to members of the family Thermoactinomycetaceae, with the highest sequence similarity to Geothermomicrobium terrae YIM 77562T (93.35 %). On the basis of morphological and chemotaxonomic characteristics, phylogenetic analysis and characteristic patterns of 16S rRNA gene signature nucleotides, strain NEAU-gxj18T represents a novel species of a new genus within the family Thermoactinomycetaceae, for which the name Baia soyae gen. nov., sp. nov. is proposed. The type strain of the type species is NEAU-gxj18T ( = CGMCC 4.7223T = DSM 46831T).

Streptomyces maoxianensis sp. nov., a novel actinomycete isolated from soil in Maoxian, China.

A novel actinomycete, designated strain NEAU-Spg16(T), was isolated from a soil sample from a pine forest in Songpinggou, Maoxian, southwest China. A polyphasic taxonomic study was carried out to establish the status of strain NEAU-Spg16(T). The cell wall peptidoglycan was found to contain LL-diaminopimelic acid and glycine. The major menaquinones were identified as MK-9(H8), MK-9(H4) and MK-9(H6). The phospholipid profile was found to contain diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and an unidentified phospholipid. The major fatty acids were identified as iso-C(16:0), C(18:0), C(16:0) and iso-C(15:0). 16S rRNA gene sequence similarity studies showed that strain NEAU-Spg16(T) belongs to the genus Streptomyces with the highest sequence similarity to Streptomyces nitrosporeus DSM 40023(T) (98.6%). However, phylogenetic analysis based on the 16S rRNA gene sequence indicated that it is most closely related to Streptomyces scopuliridis DSM 41917(T) (98.2% sequence similarity). A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-Spg16(T) can be clearly differentiated from S. scopuliridis DSM 41917(T) and S. nitrosporeus DSM 40023(T). Therefore, it is concluded that strain NEAU-Spg16(T) represents a novel species of the genus of Streptomyces, for which the name Streptomyces maoxianensis sp. nov. is proposed. The type stain is NEAU-Spg16(T) (=CGMCC 4.7139(T) = DSM 42137(T)).

Micromonospora vulcania sp. nov., isolated from volcanic sediment.

A novel actinobacterial strain, designated strain NEAU-JM2(T), was isolated from volcanic sediment collected from Longwan, Jilin province, north China and characterized using a polyphasic approach. The strain was found to have morphological and chemotaxonomic characteristics typical of the members of the genus Micromonospora. Phylogenetic analysis of the16S rRNA gene sequence also indicated that strain NEAU-JM2(T) should be classified in the genus Micromonospora and showed that close relatives are Micromonospora maoerensis NEAU-MES19(T) (99.5 %) and Micromonospora matsumotoense JCM 9104(T) (98.8 %). However, phylogenetic analysis based on the gyrB gene sequence showed that the isolate forms a separate subclade away from the close relatives in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. The low level of DNA-DNA relatedness allowed the isolate to be differentiated from M. maoerensis NEAU-MES19(T) and M. matsumotoense JCM 9104(T). Furthermore, strain NEAU-JM2(T) could also be distinguished from its close phylogenetic relatives by cultural and physiological characteristics. Therefore, it is proposed that strain NEAU-JM2(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora vulcania sp. nov. is proposed. The type strain is NEAU-JM2(T) (=CGMCC 4.7144(T) = DSM 46711(T)).

Dactylosporangium cerinum sp. nov., a novel actinobacterium isolated from the rhizosphere of Pinus koraiensis Sieb. et Zucc.

A novel actinobacterium, designated strain NEAU-TPG4(T) was isolated from rhizosphere soil of Pinus koraiensis Sieb. et Zucc. collected from Luobei, Heilongjiang Province, north China, and characterized using a polyphasic approach. Morphological and chemotaxonomic properties of strain NEAU-TPG4(T) were consistent with the description of the genus Dactylosporangium. The strain formed finger-shaped sporangia on short sporangiophores that emerged directly from substrate hyphae. The cell-wall peptidoglycan consisted of meso- and 3-hydroxy-diaminopimelic acids; arabinose, xylose and glucose were found as whole-cell sugars. The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol. The predominant menaquinones were identified as MK-9(H8) and MK-9(H6). The predominant cellular fatty acids were identified as iso-C16:0, anteiso-C15:0, anteiso-C17:0 and C18:0. Phylogenetic analysis using 16S rRNA gene sequences also indicated that the strain should be classified in the genus Dactylosporangium and showed that the closest relatives were Dactylosporangium maewongense Japan Collection of Microorganism (JCM) 15933(T) (99.6 %), Dactylosporangium siamense NBRC 106093(T) (99.6 %), Dactylosporangium aurantiacum JCM 3083(T) (99.5 %) and Dactylosporangium luteum JCM 17685(T) (99.5 %). However, the low level of DNA-DNA relatedness and several cultural and physiological characteristics allowed the strain to be distinguished from its closest relatives. Thus, it is proposed that strain NEAU-TPG4(T) represents a novel Dactylosporangium species. Dactylosporangium cerinum sp. nov. The type strain of D. cerinum is NEAU-TPG4(T) (=CGMCC 4.7152(T) = DSM 46712(T)).

Two new species of the genus Micromonospora: Micromonospora palomenae sp. nov. and Micromonospora harpali sp. nov. isolated from the insects.

Two novel actinobacteria, strains NEAU-CX1(T) and NEAU-JC6(T), were isolated from nymphs of stinkbug (Palomena viridissima Poda) and a beetle (Harpalus sinicus Hope), respectively, collected from Harbin, Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic positions of these strains. The phylogenetic analysis based on 16S rRNA gene sequence of strain NEAU-CX1(T) showed it to be most closely related to Micromonospora coxensis JCM 13248(T) (99.3 % sequence similarity), Micromonospora purpureochromogenes DSM 43821(T) (99.1 %) and Micromonospora halophytica JCM 3125(T) (98.6 %), and that of strain NEAU-JC6(T) to Micromonospora haikouensis DSM 45626(T) (99.3 %), Micromonospora carbonacea JCM 3139(T) (99.1 %) and Micromonospora krabiensis JCM 12869(T) (99.1 %). The phylogenetic analysis based on gyrB gene sequence of strain NEAU-CX1(T) showed it to be most closely related to M. purpureochromogenes DSM 43821(T) (98.0 % sequence similarity), and that of strain NEAU-JC6(T) to M. haikouensis DSM 45626(T) (99.0 %) and M. carbonacea JCM 3139(T) (98.0 %). A combination of DNA-DNA hybridization results and cultural and physiological properties indicated that the two strains can be distinguished from their closest phylogenetic relatives. Thus, strains NEAU-CX1(T) and NEAU-JC6(T) represent two novel species of the genus Micromonospora, for which the names Micromonospora palomenae sp. nov. and Micromonospora harpali sp. nov. are proposed. The type strains are NEAU-CX1(T) (=CGMCC 4.7175(T) = JCM 30056(T)) and NEAU-JC6(T) (=CGMCC 4.7173(T) = JCM 30055(T)).

Saccharothrix carnea sp. nov., an actinobacterium isolated from soil.

A novel actinobacterium, designated strain NEAU-yn17(T), was isolated from a soil sample collected at the wastewater discharge site of a pesticide factory in Harbin, northern China, and characterized using a polyphasic approach. Morphological and chemotaxonomic properties of strain NEAU-yn17(T) were consistent with the description of the genus Saccharothrix, such as the spore arrangement, the diamino acid of the peptidoglycan, the whole-cell hydrolysates, the predominant menaquinone and the phospholipid profile. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that strain NEAU-yn17(T) should also be classified in the genus Saccharothrix, with Saccharothrix saharensis DSM 45456(T) (99.52 % sequence similarity) and Saccharothrix xinjiangensis JCM 12329(T) (99.04 %) as the nearest phylogenetic relatives. A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-yn17(T) can be distinguished from its closest relatives. Therefore, strain NEAU-yn17(T) represents a novel species of the genus Saccharothrix, for which the name Saccharothrix carnea sp. nov. is proposed. The type strain is NEAU-yn17(T) ( = CGMCC 4.7097(T) = DSM 45878(T)).

Catellatospora aurea sp. nov., a novel actinomycete isolated from soil.

A novel actinomycete, designated strain NEAU-SH16(T) was isolated from a soil sample collected from the riverbank of Wusong river in Shanghai and characterized using a polyphasic approach. Morphological and chemotaxonomic properties of strain NEAU-SH16(T) were consistent with the description of the genus Catellatospora. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that strain NEAU-SH16(T) formed a distinct branch with the closest relatives Catellatospora coxensis DSM 44901(T) (99.2 %) and Catellatospora citrea DSM 44097(T) (99.0 %), an association that was supported by a bootstrap value of 78 % in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. However, the low level of DNA-DNA relatedness and some different physiological characteristics allowed the strain to be distinguished from its closest relatives. Thus, it is proposed that strain NEAU-SH16(T) represents a novel Catellatospora species. Catellatospora aurea sp. nov. The type strain of Catellatospora aurea is NEAU-SH16(T) (=CGMCC 4.7147(T) = DSM 46719(T)).

Rhodococcus kronopolitis sp. nov., a novel actinobacterium isolated from a millipede (Kronopolites svenhedind Verhoeff).

A novel actinobacterium, designated strain NEAU-ML12(T), was isolated from a millipede (Kronopolites svenhedind Verhoeff), which was collected from Fenghuang Mountain in Wuchang, Heilongjiang Province, north China. The strain was characterized using a polyphasic approach. Strain NEAU-ML12(T) was found to have morphological and chemotaxonomic characteristics typical of the members of the genus Rhodococcus. 16S rRNA gene sequence similarity analysis showed that the strain NEAU-ML12(T) belongs to the genus Rhodococcus, and was most closely related to Rhodococcus tukisamuensis Mb8(T) (98.9 %) and Rhodococcus koreensis DNP505(T) (97.7 %). Phylogenetic analysis based on 16S rRNA gene sequences also demonstrated that strain NEAU-ML12(T) should be classified in the genus Rhodococcus, forming a distinct clade with R. tukisamuensis Mb8(T) supported by a 99 % bootstrap value. However, the DNA-DNA relatedness between strain NEAU-ML12(T) and R. tukisamuensis Mb8(T) was found to be 41.9 ± 0.7 %. Furthermore, strain NEAU-ML12(T) could also be differentiated from R. tukisamuensis Mb8(T) and other closely related strains (R. koreensis DNP505(T) and Rhodococcus maanshanensis M712(T)) by morphological and physiological characteristics. Therefore, it is proposed that strain NEAU-ML12(T) represents a novel species of the genus Rhodococcus, for which the name Rhodococcus kronopolitis sp. nov. is proposed. The type strain is NEAU-ML12(T) (=CGMCC 4.7145(T) = DSM 46702(T)).

Streptomyces harbinensis sp. nov., an endophytic, ikarugamycin-producing actinomycete isolated from soybean root [Glycine max (L.) Merr].

A novel ikarugamycin-producing actinomycete, designated strain NEAU-Da3(T), was isolated from soybean root [Glycine max (L.) Merr.] and characterized using a polyphasic approach. 16S rRNA gene sequence similarity studies showed that strain NEAU-Da3(T) belonged to the genus Streptomyces, and was most closely related to Streptomyces carpaticus NRRL B-16359(T) (99.5 %), Streptomyces cheonanensis VC-A46(T) (99.3 %) and Streptomyces xiamenensis MCCC 1A01550(T) (97.2 %); similarities to other type strains of species of the genus Streptomyces were lower than 97.1 %. The maximum-likelihood phylogenetic tree based on 16S rRNA gene sequences showed that the isolate formed a distinct phyletic line with S. carpaticus NRRL B-16359(T), S. cheonanensis VC-A46(T) and S. xiamenensis MCCC 1A01550(T). This branching pattern was also supported by the tree reconstructed with the neighbour-joining method. A comparative study between strain NEAU-Da3(T) and the type strains of the closest related species of the genus Streptomyces revealed that it differed from them in morphological, physiological and biochemical characteristics. Therefore, it is proposed that strain NEAU-Da3(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces harbinensis sp. nov. is proposed. The type strain is NEAU-Da3(T) ( = CGMCC 4.7047(T) = DSM 42076(T)).

SARS-CoV-2-specific antibody and T-cell immunity in convalescents after infection wave in Beijing in late 2022.

OBJECTIVES: To evaluate SARS-CoV-2-specific antibody and T-cell responses in convalescents 5 months after infection wave in Beijing from December 2022 to January 2023 to prevent reinfection and severe disease. METHODS: Convalescents and uninfected individuals vaccinated with different doses were enrolled to assess the IFNγ T-cell responses against SARS-CoV-2 prototype strain, BF.7, BQ.1, and XBB. Neutralizing antibodies against prototype strain, BF.7, BA.5, and XBB and immunoglobulin G antibody were further analyzed. RESULTS: In convalescents, the IFNγ T-cell response was significantly higher than that of uninfected individuals (all P < 0.001), and the T-cell response against XBB had no significant difference from that of SARS-CoV-2 prototype strain and BF.7 and BQ.1 (all P > 0.05). The seropositive rates of IgG antibodies were 100% (303/303) with a median concentration of 90.52 (95% CI, 82.52-99.37). The neutralizing antibodies titers of convalescents against BF.7 and BA.5 were higher than that against the prototype strain (both P < 0.001), while XBB.1.5 was lower (P < 0.001). T-cell response, IgG and neutralizing antibodies had no significant difference in convalescents vaccinated with different doses (all P > 0.05). CONCLUSIONS: The immunities may have some protective effect against possible future outbreaks and severe diseases of COVID-19.