Incremental value of amyloid PET in a tertiary memory clinic setting in China.

INTRODUCTION: The objective of this study is to investigate the incremental value of amyloid positron emission tomography (Aß-PET) in a tertiary memory clinic setting in China. METHODS: A total of 1073 patients were offered Aß-PET using 18F-florbetapir. The neurologists determined a suspected etiology (Alzheimer's disease [AD] or non-AD) with a percentage estimate of their confidence and medication prescription both before and after receiving the Aß-PET results. RESULTS: After disclosure of the Aß-PET results, etiological diagnoses changed in 19.3% of patients, and diagnostic confidence increased from 69.3% to 85.6%. Amyloid PET results led to a change of treatment plan in 36.5% of patients. Compared to the late-onset group, the early-onset group had a more frequent change in diagnoses and a higher increase in diagnostic confidence. DISCUSSION: Aß-PET has significant impacts on the changes of diagnoses and management in Chinese population. Early-onset cases are more likely to benefit from Aß-PET than late-onset cases. HIGHLIGHTS: Amyloid PET contributes to diagnostic changes and its confidence in Chinese patients. Amyloid PET leads to a change of treatment plans in Chinese patients. Early-onset cases are more likely to benefit from amyloid PET than late-onset cases.

Systematic assessment of plasma biomarkers in spinocerebellar ataxia.

BACKGROUND AND OBJECTIVES: Plasma neurofilament light (NfL), glial fibrillary acidic protein (GFAP), phosphorylated-tau (p-tau), and ß-amyloid (Aß) have emerged as promising markers in several neurodegenerative disorders, but whether they can be used as biomarkers in spinocerebellar ataxias (SCA) is yet to be determined. This study aimed to identify sensitive plasma markers for SCA and investigate their effectiveness in tracking ataxia severity, cognition, non-motor symptoms, and brain atrophy. METHODS: This observational study recruited consecutive participants from Huashan Hospital and the CABLE study from November 2019. Patients with SCA were genetically diagnosed, grouped according to the ataxia severity, and compared with healthy older individuals and patients with multiple system atrophy type C (MSA-C). Plasma NfL, GFAP, p-tau, and Aß levels were measured by Simoa in all participants. Analysis of covariance, Spearman correlation, and multivariable regression were used to explore candidate markers in SCA. RESULTS: A total of 190 participants (60 SCA, 56 MSA-C, and 74 healthy controls) were enrolled. Plasma NfL level increased early in the pre-ataxic stage of SCA (32.23 ± 3.07 vs. 11.41 ± 6.62 pg/mL in controls), was positively associated with the ataxia severity (r = 0.45, P = 0.005) and CAG repeat length (r = 0.51, P = 0.001), varied among the different SCA subtypes (39.57 ± 13.50 pg/mL in SCA3, which was higher than 28.17 ± 8.02 pg/mL in SCA2, 17.08 ± 6.78 pg/mL in SCA8, and 24.44 ± 18.97 pg/mL in rare SCAs; P < 0.05), and was associated with brainstem atrophy. NfL alone (area under the curve [AUC] 0.867) or combined with p-tau181 and Aß (AUC 0.929), showed excellent performance in discriminating SCA patients from controls. Plasma GFAP distinguished SCA from MSA-C with moderate accuracy (AUC > 0.700) and correlated with cognitive performance and cortical atrophy. Changes in levels of p-tau181 and Aß were observed in SCA patients compared to controls. They were both correlated with cognition, while Aß was also associated with non-motor symptoms, such as anxiety and depression. DISCUSSION: Plasma NfL may serve as a sensitive biomarker for SCA, and its level is elevated in the pre-ataxic stage. The different performance of NfL and GFAP indicates differences in the underlying neuropathology of SCA and MSA-C. Moreover, amyloid markers may be useful for detecting memory dysfunction and other non-motor symptoms in SCA.

Multipredictor risk models for predicting individual risk of Alzheimer's disease.

BACKGROUND: Early prevention of Alzheimer's disease (AD) is a feasible way to delay AD onset and progression. Information on AD prediction at the individual patient level will be useful in AD prevention. In this study, we aim to develop risk models for predicting AD onset at individual level using optimal set of predictors from multiple features. METHODS: A total of 487 cognitively normal (CN) individuals and 796 mild cognitive impairment (MCI) patients were included from Alzheimer's Disease Neuroimaging Initiative. All the participants were assessed for clinical, cognitive, magnetic resonance imaging and cerebrospinal fluid (CSF) markers and followed for mean periods of 5.6 years for CN individuals and 4.6 years for MCI patients to ascertain progression from CN to incident prodromal stage of AD or from MCI to AD dementia. Least Absolute Shrinkage and Selection Operator Cox regression was applied for predictors selection and model construction. RESULTS: During the follow-up periods, 139 CN participants had progressed to prodromal AD (CDR ≥ 0.5) and 321 MCI patients had progressed to AD dementia. In the prediction of individual risk of incident prodromal stage of AD in CN individuals, the AUC of the final CN model was 0.81 within 5 years. The final MCI model predicted individual risk of AD dementia in MCI patients with an AUC of 0.92 within 5 years. The models were also associated with longitudinal change of Mini-Mental State Examination (p < 0.001 for CN and MCI models). An Alzheimer's continuum model was developed which could predict the Alzheimer's continuum for individuals with normal AD biomarkers within 3 years with high accuracy (AUC = 0.91). CONCLUSIONS: The risk models were able to provide personalized risk for AD onset at each year after evaluation. The models may be useful for better prevention of AD.

Plasma Glial Fibrillary Acidic Protein in the Alzheimer Disease Continuum: Relationship to Other Biomarkers, Differential Diagnosis, and Prediction of Clinical Progression.

BACKGROUND: Plasma glial fibrillary acidic protein (GFAP) has emerged as a promising biomarker in neurological disorders, but further evidence is required in relation to its usefulness for diagnosis and prediction of Alzheimer disease (AD). METHODS: Plasma GFAP was measured in participants with AD, non-AD neurodegenerative disorders, and controls. Its diagnostic and predictive value were analyzed alone or combined with other indicators. RESULTS: A total of 818 participants were recruited (210 followed). Plasma GFAP was significantly higher in AD than in non-AD dementia and non-demented individuals. It increased in a stepwise pattern from preclinical AD, through prodromal AD to AD dementia. It effectively distinguished AD from controls [area under the curve (AUC) > 0.97] and non-AD dementia (AUC > 0.80) and distinguished preclinical (AUC > 0.89) and prodromal AD (AUC > 0.85) from Aß-normal controls. Adjusted or combined with other indicators, higher levels of plasma GFAP displayed predictive value for risk of AD progression (adjusted hazard radio= 4.49, 95%CI, 1.18-16.97, P = 0.027 based on the comparison of those above vs below average at baseline) and cognitive decline (standard-ß=0.34, P = 0.002). Additionally, it strongly correlated with AD-related cerebrospinal fluid (CSF)/neuroimaging markers. CONCLUSIONS: Plasma GFAP effectively distinguished AD dementia from multiple neurodegenerative diseases, gradually increased across the AD continuum, predicted the individual risk of AD progression, and strongly correlated with AD CSF/neuroimaging biomarkers. Plasma GFAP could serve as both a diagnostic and predictive biomarker for AD.

Plasma Biomarkers and Positron Emission Tomography Tau Pathology in Progressive Supranuclear Palsy.

BACKGROUND: Development of disease-modifying therapeutic trials of progressive supranuclear palsy (PSP) urges the need for sensitive fluid biomarkers. OBJECTIVES: The objectives of this study were to explore the utility of plasma biomarkers in the diagnosis, differential diagnosis, and assessment of disease severity, brain atrophy, and tau deposition in PSP. METHODS: Plasma biomarkers were measured using a single-molecule array in a cohort composed of patients with PSP, Parkinson's disease (PD), multiple system atrophy with predominant parkinsonism (MSA-P), and healthy controls (HCs). RESULTS: Plasma neurofilament light chain (NfL) outperformed other plasma makers (ie, glial fibrillary acidic protein [GFAP], phosphorylated-tau 181 [p-tau181], amyloid-ß 1-40, amyloid-ß 1-42) in identifying PSP from HC (area under the curve [AUC] = 0.904) and from MSA-P (AUC = 0.711). Plasma GFAP aided in distinguishing PSP from HC (AUC = 0.774) and from MSA-P (AUC = 0.832). It correlated with brainstem atrophy and higher regional tau accumulation. However, plasma p-tau181 neither helped in diagnosis nor was it associated with clinical or neuroimaging measures. CONCLUSIONS: Plasma NfL and GFAP showed different values in differentiating PSP from HC or controls with other forms of neurodegenerative parkinsonism and detecting disease severity, brain atrophy, or tau deposition in PSP. © 2023 International Parkinson and Movement Disorder Society.

Identifying causal genes for depression via integration of the proteome and transcriptome from brain and blood.

Genome-wide association studies (GWASs) have identified numerous risk genes for depression. Nevertheless, genes crucial for understanding the molecular mechanisms of depression and effective antidepressant drug targets are largely unknown. Addressing this, we aimed to highlight potentially causal genes by systematically integrating the brain and blood protein and expression quantitative trait loci (QTL) data with a depression GWAS dataset via a statistical framework including Mendelian randomization (MR), Bayesian colocalization, and Steiger filtering analysis. In summary, we identified three candidate genes (TMEM106B, RAB27B, and GMPPB) based on brain data and two genes (TMEM106B and NEGR1) based on blood data with consistent robust evidence at both the protein and transcriptional levels. Furthermore, the protein-protein interaction (PPI) network provided new insights into the interaction between brain and blood in depression. Collectively, four genes (TMEM106B, RAB27B, GMPPB, and NEGR1) affect depression by influencing protein and gene expression level, which could guide future researches on candidate genes investigations in animal studies as well as prioritize antidepressant drug targets.

Sleep, physical activity, sedentary behavior, and risk of incident dementia: a prospective cohort study of 431,924 UK Biobank participants.

Although sleep, physical activity and sedentary behavior have been found to be associated with dementia risk, findings are inconsistent and their joint relationship remains unclear. This study aimed to investigate independent and joint associations of these three modifiable behaviors with dementia risks. A total of 431,924 participants (median follow-up 9.0 years) without dementia from UK Biobank were included. Multiple Cox regressions were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Models fitted with restricted cubic spline were conducted to test for linear and nonlinear shapes of each association. Sleep duration, leisure-time physical activity (LTPA), and screen-based sedentary behavior individually associated with dementia risks in different non-linear patterns. Sleep duration associated with dementia in a U-shape with a nadir at 7 h/day. LTPA revealed a curvilinear relationship with dementia in diminishing tendency, while sedentary behavior revealed a J-shaped relationship. The dementia risk was 17% lower in the high LTPA group (HR[95%CI]: 0.83[0.76-0.91]) and 22% higher in the high sedentary behavior group (1.22[1.10-1.35]) compared to the corresponding low-level group, respectively. A combination of seven-hour/day sleep, moderate-to-high LTPA, and low-to-moderate sedentary behavior showed the lowest dementia risk (0.59[0.50-0.69]) compared to the referent group (longer or shorter sleep/low LTPA/high sedentary behavior). Notably, each behavior was non-linearly associated with brain structures in a pattern similar to its association with dementia, suggesting they may affect dementia risk by affecting brain structures. Our findings highlight the potential to change these three daily behaviors individually and simultaneously to reduce the risk of dementia.

Taxonomic descriptions of Aeromicrobium duanguangcaii sp. nov., Aeromicrobium wangtongii sp. nov. and Aeromicrobium senzhongii sp. nov.

Six Gram-stain-positive, facultative anaerobic, nonmotile and rod-shaped strains, designated zg-Y50T, zg-Y1362, zg-Y1379T, zg-Y869, zg-629T and zg-Y636, were isolated from the intestinal contents of Marmota himalayana in Qinghai Province, PR China. Strains zg-Y50T, zg-Y1379T and zg-629T exhibited the highest 16S rRNA gene sequence similarities of 99.2, 98.9 and 98.8 % to Aeromicrobium choanae 9 H-4T, Aeromicrobium ginsengisoli JCM 14732T and Aeromicrobium flavum TYLN1T, respectively. Phylogenetic and phylogenomic analyses based on the 16S rRNA gene and genomic sequences, respectively, revealed that the six strains formed three distinct clades within the genus Aeromicrobium. The genome sizes of strains zg-Y50T, zg-Y1379T and zg-629T were 3.1-3.7 Mb, with DNA G+C contents of 69.6-70.4 mol%. Average nucleotide identity and digital DNA-DNA hybridization values between each novel strain and available members of the genus Aeromicrobium were all below species thresholds. All novel strains contained MK-9 (H4) as the major menaquinone and diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol as the polar lipids. The predominant fatty acid of the six isolates was C18 : 1 ω9c. The cell-wall peptidoglycan contained ʟʟ-diaminopimelic acid as the diagnostic diamino acid. Based on the results from this polyphasic taxonomic study, three novel species in the genus Aeromicrobium are proposed, namely, Aeromicrobium duanguangcaii sp. nov. (zg-Y50T=GDMCC 1.2981T=KCTC 49764T), Aeromicrobium wangtongii sp. nov. (zg-Y1379T=GDMCC 1.2982T=KCTC 49765T) and Aeromicrobium senzhongii sp. nov. (zg-629T=CGMCC 1.17414T=JCM 33888T).

Pharmacological treatment of neuropsychiatric symptoms of dementia: a network meta-analysis.

BACKGROUND: Pharmacological treatments are very common to be used for alleviating neuropsychiatric symptoms (NPS) in dementia. However, decision on drug selection is still a matter of controversy. AIMS: To summarise the comparative efficacy and acceptability of currently available monotherapy drug regimens for reducing NPS in dementia. METHOD: We searched PubMed, MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials between inception and 26 December 2022 without language restrictions; and reference lists scanned from selected studies and systematic reviews. Double-blind randomised controlled trials were identified from electronic databases for reporting NPS outcomes in people with dementia. Primary outcomes were efficacy and acceptability. Confidence in the evidence was assessed using Confidence in Network Meta-Analysis (CINeMA). RESULTS: We included 59 trials (15,781 participants; mean age, 76.6 years) and 15 different drugs in quantitative syntheses. Risperidone (standardised mean difference [SMD] -0.20, 95% credible interval [CrI] -0.40 to -0.10) and galantamine (-0.20, -0.39 to -0.02) were more effective than placebo in short-term treatment (median duration: 12 weeks). Galantamine (odds ratio [OR] 1.95, 95% CrI 1.38-2.94) and rivastigmine (1.87, 1.24-2.99) were associated with more dropouts than placebo, and some active drugs. Most of the results were rated as low or very low according to CINeMA. CONCLUSIONS: Despite the scarcity of high-quality evidence, risperidone is probably the best pharmacological option to consider for alleviating NPS in people with dementia in short-term treatment when considering the risk-benefit profile of drugs.

Genome-wide association study identifies APOE locus influencing plasma p-tau181 levels.

As a promising diagnostic and prognostic biomarker for Alzheimer's Disease (AD), plasma p-tau181 is robustly differentiated AD dementia from non-AD neurodegenerative diseases. We aimed to discover single nucleotide polymorphisms (SNPs) associated with plasma phosphorylated tau at threonine 181 (p-tau181) levels that affect the risk of developing AD. We carried out a genome-wide association study for plasma p-tau181 levels using participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI). The thresholds of P < 5 × 10-6 was used for suggestive associations, and thresholds of P < 5 × 10-8 was used for significant associations. Subsequently, we tested whether the associations remained significant in subgroup analysis and examined the impact of SNPs on the longitudinal changes in plasma p-tau181 levels. A total of 714 eligible non-Hispanic white participants with plasma p-tau181 data were included. The most significant SNP (rs769449, P = 6.26 × 10-8) in APOE gene was suggestively associated with plasma p-tau181, which is close to the genome-wide significance threshold. The minor allele (A) of rs769449 in the APOE was associated with higher plasma p-tau181 levels in a dose-dependent fashion. Besides, rs769449- A carriers were more likely to exhibit a greater longitudinal cognitive decline (P = 0.03). Our results suggest that the AD risk variant in the APOE gene participates in the regulation of plasma p-tau181. The plasma p-tau181 concentration could be a useful endophenotype for identifying risk for AD in elderly individuals.

Nocardia sputi sp. nov. isolated from the sputum of patients with pulmonary infection.

Two Gram-stain-positive, aerobic and rod-shaped actinomycetes (strains CY18T and CY8) were isolated from the sputum of two patients with pulmonary infections, and their taxonomic status was investigated. The 16S rRNA gene sequences and the results of phylogenetic analyses indicated that CY18T and CY8 were identical (100 %) and were most closely related to Nocardia beijingensis CGMCC 4.1521T (99.9 %) and Nocardia araoensis NBRC 100135T (99.5 %). The predominant cellular fatty acids of CY18T and CY8 were C16 : 0, C18 : 0, C18 : 1ω9c and summed feature 3 (comprising C16 : 1É·7c and/or C16 : 1É·6c), and the major menaquinone was MK-8(H4ω-cycl).The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The whole-cell hydrolytic sugar pattern consisted of arabinose and glucose. The polar lipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, two unidentified phospholipids, three unidentified glycolipids and two unidentified lipids.The DNA G+C contents of CY18T and CY8 were 67.9 and 68.0 % respectively. The digital DNA-DNA hybridization and average nucleotide identity values between the two novel strains and closely related species were well under the 70 % and 95-96 % thresholds, respectively, but these values between the two novel strains were 95.5 % and 99.5 %, respectively. On the basis of morphological and chemotaxonomic characteristics and the results of phylogenetic analyses, strains CY18T and CY8 represent a novel species of the genus Nocardia, for which the name Nocardia sputi sp. nov. is proposed. The type strain is CY18T (=GDMCC 1.3318T = JCM 33932T).

Gordonia zhenghanii sp. nov. and Gordonia liuliyuniae sp. nov., isolated from bat faeces.

Four mesophilic actinobacteria (HY002T, HY442, HY366T and HY285) isolated from the faeces of bats collected in southern China were found to be strictly aerobic, non-motile, rod-shaped, oxidase-negative, Gram-stain-positive and catalase-positive. Strains HY002T and HY366T contained meso-diaminopimelic acid as the diagnostic diamino acid and MK-9(H2) the sole respiratory quinone. Arabinose, galactose and ribose were detected in the whole-cell hydrolysates of both type strains. The main cellular fatty acids (> 10.0%) of all strains were C16 : 0, C18 : 1 ω9c, 10-methyl-C18 : 0 and summed feature 3. Strains HY002T and HY366T contained diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidyl inositol mannosides as the major polar lipids. The phylogenetic/phylogenomic analyses based on 16S rRNA gene and genomic sequence comparison revealed that the four strains belong to the genus Gordonia, most closely related to G. neofelifaecis NRRL B-59395T(98.2-98.3% sequence similarity) on the EzBioCloud database. The G+C contents of strains HY002T and HY366T based on genomic DNA were 66.5 and 66.9%, respectively. The DNA-DNA relatedness values between the two types strains and members of the genus Gordonia were far below 70 % (18.6-23.1 %). All genotypic and phenotypic data indicated that the four strains are representatives of two novel separate species, for which the names Gordonia zhenghanii sp. nov. and Gordonia liuliyuniae sp. nov. are proposed, with HY002T (=CGMCC 4 7757T=JCM 34 878T) and HY366T (=CGMCC 1 19146T=JCM 34 879T) as the respective type strains.

Gordonia jinghuaiqii sp. nov. and Gordonia zhaorongruii sp. nov., isolated from Tibetan Plateau wildlife.

Four mesophilic and Gram-stain-positive strains (zg-686T/zg-691 and HY186T/HY189) isolated from Tibetan Plateau wildlife (PR China) belong to the genus Gordonia according to 16S rRNA gene and genomic sequence-based phylogenetic/genomic results. They have a DNA G+C content range of 67.4-68.3 mol% and low DNA relatedness (19.2-27.6 %) with all available genomes in the genus Gordonia. Strains zg-686T/zg-691 and HY186T/HY189 had C18 : 1ω9c, C18 : 0 10-methyl, C16 : 1 ω7c/C16 : 1ω6c and C16 : 0 as major cellular fatty acids. The polar lipids detected in strains zg-686T and HY186T included diphosphatidylglycerol, phosphatidylethanolamine, phosphatidyl inositol mannoside and phosphatidylinositol. The respiratory quinones comprised MK8(H2) (10.8 %) and MK9(H2) (89.2 %) for strain zg-686T, and MK6 (7.7 %), MK8(H2) (8.4 %), MK8(H4) (3.1 %) and MK9(H2) (80.8 %) for strain HY186T. Optimal growth conditions were pH 7.0, 35-37 °C and 0.5-1.5 % NaCl (w/v) for strains pair zg-686T/zg-691, and pH 7.0, 28 °C and 1.5 % (w/v) NaCl for strains pair HY186T/HY189. Based on these genotypic and phenotypic results, these four strains could be classified as two different novel species in the genus Gordonia, for which the names Gordonia jinghuaiqii sp. nov. and Gordonia zhaorongruii sp. nov. are proposed. The type strains are zg-686T (=GDMCC 1.1715T =JCM 33890T) and HY186T (=CGMCC 4.7607T =JCM 33466T), respectively.

Microbacterium chengjingii sp. nov. and Microbacterium fandaimingii sp. nov., isolated from bat faeces of Hipposideros and Rousettus species.

Four aerobic, Gram-stain-positive, rod-shaped bacteria (HY60T, HY54, HY82T and HY89) were isolated from bat faeces of Hipposideros and Rousettus species collected in PR China. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the four novel strains formed two separate but adjacent subclades close to Microbacterium agarici CGMCC 1.12260T (97.6-97.7 % similarity), Microbacterium humi JCM 18706T (97.3-97.5 %) and Microbacterium lindanitolerans JCM 30493T (97.3-97.4 %). The 16S rRNA gene sequence similarity was 98.3 % between strains HY60T and HY82T, and identical within strain pairs HY60T/HY54 and HY82T/HY89. The DNA G+C contents of strains HY60T and HY82T were 61.9 and 63.3 mol%, respectively. The digital DNA-DNA hybridization and average nucleotide identity values between each novel strain and their closest relatives were all below the 70 % and 95-96 % thresholds for species delimitation, respectively. All four novel strains contained anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0 and iso-C15 : 0 as the main fatty acids, MK-11 and MK-12 as the major respiratory quinones, and diphosphatidylglycerol, phosphatidylglycerol and one unidentified glycolipid as the predominant polar lipids. The cell-wall peptidoglycan was of B type and contained alanine, glutamate, glycine and ornithine. The acyl type of the muramic acid was glycolyl. The whole-cell sugars were rhamnose and ribose. Based on the foregoing polyphasic analyses, it was concluded that the four uncharacterized strains represented two novel species of the genus Microbacterium, for which the names Microbacterium chengjingii sp. nov. [type strain HY60T (=CGMCC 1.17468T=GDMCC 1.1951T=KACC 22102T)] and Microbacterium fandaimingii sp. nov. [type strain HY82T (=CGMCC 1.17469T=GDMCC 1.1949T=KACC 22101T)] are proposed, respectively.

Identification of Haloactinobacterium kanbiaonis sp. nov. and Ruania zhangjianzhongii sp. nov., two novel species of the family Ruaniaceae isolated from faeces of bats (Hipposideros spp.).

Two pairs of aerobic, Gram-stain-positive, rod-shaped strains (HY164T/HY044, HY168T/HY211) were isolated from bat faecal samples. Strains HY164T and HY044 were motile with a polar flagellum, and had 16S rRNA gene similarity of 95.1-98.6 % to Haloactinobacterium album YIM 93306T and Haloactinobacterium glacieicola T3246-1T; strains HY168T and HY211 were most similar to Ruania albidiflava DSM 18029T (96.6 %). Phylogenetic trees based on 16S rRNA gene and whole genome sequences revealed affiliation of strains HY164T and HY168T to the family Ruaniaceae, representing novel lineages in the genera Haloactinobacterium and Ruania, respectively, which was also supported by the results for average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH). For all isolates, the principal cellular fatty acids were anteiso-C15 : 0 and iso-C14 : 0. HY164T and HY168T had MK-8(H4) as the predominant isoprenoid quinone, diphosphatidylglycerol, phosphatidylglycerol, several unidentified phospholipids and glycolipids as common polar lipids while the latter strain additionally contained one unidentified aminophospholipid and one unidentified phosphoglycolipid. Besides sharing alanine, glutamic acid and lysine with HY164T, HY168T additionally contained 2,4-diaminobutyric acid in the cell-wall peptidoglycan. The whole-cell sugars of HY164T were ribose and rhamnose, while HY168T only included the latter. The DNA G+C contents of HY164T and HY168T were 71.0 and 69.1 mol%, respectively. Combining the polyphasic taxonomic data, HY164T (=CGMCC 4.7606T=JCM 33464T) is classified as representing a novel species of the genus Haloactinobacterium with the proposed name Haloactinobacterium kanbiaonis sp. nov., and HY168T (=CGMCC 1.16970T=JCM 33465T) is proposed to represent a novel species of the genus Ruania with the name Ruania zhangjianzhongii sp. nov.

Corynebacterium lizhenjunii sp. nov., isolated from the respiratory tract of Marmota himalayana, and Corynebacterium qintianiae sp. nov., isolated from the lung tissue of Pseudois nayaur.

Four Gram-stain-positive, non-motile and asporous bacilli (strains ZJ-599T, ZJ-621, MC1420T and MC1482), isolated from animal tissue and environmental samples collected on the Qinghai-Tibet Plateau, PR China, were taxonomically characterized. Based on the results of 16S rRNA gene sequence analyses, the closest relatives of strains ZJ-599T and ZJ-621 were Corynebacterium endometrii LMM-1653T (97.5 %), Corynebacterium phocae M408/89/1T (96.5 %) and Corynebacterium flavescens OJ8T (96.3 %), whereas strains MC1420T and MC1482 were closest to Corynebacterium sanguinis CCUG 58655T (98.9 %), Corynebacterium mycetoides DSM 20632T (98.4 %) and Corynebacterium lipophiloflavum DSM 44291T (97.9 %). The results of rpoB gene sequence similarity analysis indicated that C. phocae M408/89/1T and C. sanguinis CCUG 58655T were closest to strains ZJ-599T/ZJ-621 (83.5 %) and MC1420T/MC1482 (91.8 %), respectively. The two novel type strains shared a similarity of 95.2 % in 16S rRNA and 81.3 % in rpoB gene sequences. The TAP-PCR DNA fingerprint and MALDI-TOF MS spectrum patterns clearly differentiated the novel isolates within and between each pair of strains. Strain ZJ-599T had 21.9-22.4 % digital DNA-DNA hybridization (dDDH) scores with C. endometrii LMM-1653T, C. phocae M408/89/1T and C. flavescens OJ8T, and 72.3-72.9 % of average nucleotide identity (ANI) with them. Similarly, strain MC1420T had 22.9-23.7 % dDDH values with C. sanguinis CCUG 58655T, C. mycetoides DSM 20632T and C. lipophiloflavum DSM 44291T, and 80.4-81.3 % ANI scores with them. Strain ZJ-599T had a 23.1 % dDDH value and 70.5 % ANI score with strain MC1420T, both below the corresponding thresholds for species delineation. Strains ZJ-599T and MC1420T both contain mycolic acids and have MK-8(H2) and MK-9(H2) as the predominant respiratory quinones, meso-diaminopimelic acid as the diagnostic diamino acid, and C18 : 1 ω9c as the main fatty acid. C17 : 1 ω8c and C15 : 1 ω8c were predominant in strain ZJ-599T in contrast to C17 : 1 ω7c being predominant in strain MC1420T. The main polar lipids in strain ZJ-599T were diphosphatidylglycerol, phosphatidylinositol and one unidentified glycolipid, while strain MC1420T had diphosphatidylglycerol, phosphatidylglycerol and one unidentified lipid as the major components. Since the two pairs of novel strains (ZJ-599T/ZJ-621, MC1420T/MC1482) distinctly differ from each other and from their nearest relatives, two novel species of the genus Corynebacterium are proposed, namely Corynebacterium lizhenjunii (type strain ZJ-599T=GDMCC 1.1779T=JCM 34341T) and Corynebacterium qintianiae (type strain MC1420T=GDMCC 1.1783T=JCM 34340T), respectively.

Acinetobacter lanii sp. nov., Acinetobacter shaoyimingii sp. nov. and Acinetobacter wanghuae sp. nov., isolated from faeces of Equus kiang.

Six aerobic, non-motile, non-haemolytic, Gram-stain-negative, oxidase-negative strains (185T, 187, 323-1T, 194, dk386T and dk771) were recovered from different faecal samples of Equus kiang on the Qinghai-Tibet Plateau. In the 16S rRNA gene sequences, one strain pair, 185T/187, shared highest similarity to Acinetobacter equi 114T (97.9 %), and the other two (323-1T/194 and dk771T/dk386) to Acinetobacter harbinensis CGMCC 1.12528T (98.6 and 97.0 %, respectively). Phylogenomic tree analysis showed that these six strains formed three separate clades in the genus Acinetobacter. Digital DNA-DNA hybridization values of each pair of the isolates with all members of the genus Acinetobacter were far below 70 %. The main cellular fatty acids of all six strains were C18 : 1 ω9c, C16 : 0 and summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c). Q-9 was the predominant respiratory quinone for strains 185T, 323-1T and dk386T. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Based on the genotypic, phenotypic and biochemical analyses, these six strains represent three novel species of the genus Acinetobacter, for which the names Acinetobacter lanii sp. nov., Acinetobacter shaoyimingii sp. nov. and Acinetobacter wanghuae sp. nov. are proposed. The type strains are 185T (=CGMCC 1.13636T=JCM 33607T), 323-1T (=CGMCC 1.13940T=JCM 33608T) and dk386T (=CGMCC 1.16589T=JCM 33592T), respectively.

Characterization of isolates of members of the genus Actinomyces from Marmota himalayana: description of Actinomyces faecalis sp. nov., Actinomyces respiraculi sp. nov., and Actinomyces trachealis sp. nov.

Six novel strains (ZJ34T, ZJ561, ZJ750T, ZJ1629, zg-993T and zg-987) isolated from faeces and respiratory tracts of Marmota himalayana from the Qinghai-Tibet Plateau of PR China were characterized comprehensively. The results of analyses of the 16S rRNA gene and genome sequences indicated that the six strains represent three novel species of the genus Actinomyces, and are closely related to Actinomyces urogenitalis DSM 15434T (16S rRNA gene sequences similarities, 94.9-98.7 %), Actinomyces weissii CCUG 61299T (95.6-96.6 %), Actinomyces bovis CCTCC AB2010168T (95.7 %) and Actinomyces bowdenii DSM 15435T (95.2-96.4 %), with values of digital DNA-DNA hybridization less than 30.1 % when compared with their closest relatives but higher than 70 % within each pair of novel strains (ZJ34T/ZJ561, ZJ750T/ZJ1629 and zg-993T/zg-987). All the novel strains had C18 : 1 ω9c and C16 : 0 as the two most abundant major fatty acids. MK-9(H4) or MK-8(H4) was the sole or predominant respiratory quinone of strains ZJ34T, ZJ750T and zg-993T and their polar lipid profiles differed, but all had diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and phosphatidyl inositol mannoside as major components. ZJ750T shared identical peptidoglycan amino acid profile with ZJ34T (alanine, glutamic acid, lysine and ornithine) and the same whole-cell sugar composition with zg-993T (glucose, rhamnose and ribose). Strain zg-993T contained alanine, aspartic acid, glutamic acid, glycine and lysine in the peptidoglycan, and the only sugar in ZJ34T was ribose. The DNA G+C contents of the novel strains were within the range of 65.8-70.1 mol%. On the basis of the results from the aforementioned analyses, the six novel strains were classified as representing three novel species of genus Actinomyces, for which the names Actinomyces faecalis sp. nov. [type strain ZJ34T (=GDMCC 1.1952T=JCM 34355T)], Actinomyces respiraculi sp. nov. [type strain ZJ750T (=GDMCC 1.1950T=JCM 34356T)] and Actinomyces trachealis sp. nov. [type strain zg-993T (=GDMCC 1.1956T=JCM 34357T)] were proposed, respectively.

Vagococcus xieshaowenii sp. nov., isolated from snow finch (Montifringilla taczanowskii) cloacal content.

A Gram-stain-positive, coccus-shaped, non-motile bacterium, designated CF-49T, was isolated from the cloacal content of a snow finch, which was incidentally captured in a plateau pika burrow on the Qinghai-Tibet Plateau, PR China. Analysis of the 16S rRNA gene sequence showed that strain CF-49T was closely related to Vagococcus elongatus CCUG 51432T (96.5 % similarity), Vagococcus fluvialis NCFB 2497T (96.0 %) and Vagococcus lutrae CCUG 39187T (95.9 %), whereas the similarity to another isolate (CF-210) was 99.9 %. Strains CF-49T and CF-210 grew optimally at 37 °C and pH 7.0 and in the presence of 0.5 % (w/v) NaCl. Acid was produced from N-acetylglucosamine, cellobiose, d-fructose, d-glucose, d-mannose, d-mannitol, maltose, d-ribose and salicin. The cell-wall peptidoglycan type was A4α (l-Lys-d-Asp). The major cellular fatty acids (>10 %) were C16 : 0 (35.6 %), C14 : 0 (17.3 %), C18 : 1 ω9c (16.2 %) and C16 : 1 ω9c (10.6 %). The predominant respiratory quinone was menaquinone MK-7 (68.8 %). The G+C content of the genomic DNA was 35.9 mol%. Digital DNA-DNA hybridization of strain CF-49T with V. fluvialis DSM 5731T, V. elongatus CCUG 51432Tand V. lutrae CCUG 39187T resulted in relatedness values of 21.4, 23.3 and 24.6 %, respectively. Based on results from polyphasic analyses, our two isolates are proposed to represent a novel species in the genus Vagococcus, with the name Vagococcus xieshaowenii. The type strain is CF-49T (=CGMCC 1.6436T=GDMCC 1.1588T=JCM 33477T).

Actinomyces wuliandei sp. nov., Corynebacterium liangguodongii sp. nov., Corynebacterium yudongzhengii sp. nov. and Oceanobacillus zhaokaii sp. nov., isolated from faeces of Tibetan antelope in the Qinghai-Tibet plateau of China.

Eight Gram-stain-positive, rod-shaped bacterial strains were isolated from faeces of Tibetan antelopes on the Tibet-Qinghai Plateau of China. Genomic sequence analysis showed that the strains belong to the genera Actinomyces (strains 299T and 340), Corynebacterium (strains 2184T, 2185, 2183T and 2189) and Oceanobacillus (strains 160T and 143), respectively, with a percentage of similarity for the 16S rRNA gene under the species threshold of 98.7 % except for strains 160T and 143 with Oceanobacillus arenosus CAU 1183T (98.8 %). The genome sizes (and genomic G+C contents) were 3.1 Mb (49.4 %), 2.5 Mb (64.9 %), 2.4 Mb (66.1 %) and 4.1 Mb (37.1 %) for the type strains 299T, 2183T, 2184T and 160T, respectively. Two sets of the overall genome relatedness index values between our isolates and their corresponding closely related species were under species thresholds (95 % for average nucleotide identity, and 70 % for digital DNA-DNA hybridization). These results, together with deeper genotypic, genomic, phenotypic and biochemical analyses, indicate that these eight isolates should be classified as representing four novel species. Strain 299T (=CGMCC 1.16320T=JCM 33611T) is proposed as representing Actinomyces wuliandei sp. nov.; strain 2184T (=CGMCC 1.16417T=DSM 106203T) is proposed as representing Corynebacterium liangguodongii sp. nov.; strain 2183T (=CGMCC 1.16416T=DSM 106264T) is proposed as representing Corynebacterium yudongzhengii sp. nov.; and strain 160T (=CGMCC 1.16367T=DSM 106186T) is proposed as representing Oceanobacillus zhaokaii sp. nov.