To investigate the prevalence and diversity of Chlamydia spp. in domestic birds in China, oral and cloacal swabs of healthy chickens, ducks, geese and pigeons were collected nationwide from live-animal markets and examined by Chlamydia spp. 23 S rRNA gene FRET-PCR followed by high-resolution melting curve analysis and confirmatory sequencing. Overall, 26.2% of the birds (602/2,300) were positive for Chlamydia spp. and five Chlamydia spp. were identified. While occasional detection of C. suis and C. muridarum in poultry is reported here for the first time, the predominant chlamydial agent was C. gallinacea representing 63.8% of all positives (384/602) and 81.2% of positive chickens (359/442). Analysis of the C. gallinacea ompA phylogeny revealed at least 13 well segregated variants (serovars). Seven-month monitoring of C. gallinacea-infected chickens indicated that the infection was persistent. C. gallinacea-infected chickens remained without overt clinical disease, but showed body weight gains significantly reduced by 6.5–11.4% beginning in week 3 post-infection. This study indicates that C. gallinacea is the endemic chlamydial species in chickens, whereas C. psittaci dominates only in pigeons. Further studies are required to address the specific conditions under which C. gallinacea could act as an avian pathogen and possibly also a zoonotic agent.

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Brucellosis is a serious public health problem in Ulanqab, which is a region located in the middle of the Inner Mongolia Autonomous Region adjacent to Shanxi and Hebei provinces. The disease is prevalent in both the latter provinces and Ulanqab with the highest prevalence of brucellosis occurring in Inner Mongolia. The MLVA-16 scheme is a genotyping tool for assessing genetic diversity and relationships among isolates. Moreover, this genotyping tool can also be applied to epidemiological trace-back investigations. This study reports the occurrence of at least two B. melitensis biovars (1 and 3) in Ulanqab, encompassing 22 and 94 isolates, respectively. B. melitensis biovar 3 was the predominant biovar in the area examined. Panel 1 (MLVA-8) identified three genotypes (42, 63, and 114), with genotype 42 (n = 101) representing 87% of the tested strains. MLVA-11 identified eight genotypes (116, 111, 297, 291, and 342–345) from 116 of the analyzed isolates. All of these isolates were identified as belonging to the East Mediterranean group. Genotype 116 (n = 94) was the predominant genotype and represented 81% of the isolates. The isolates pertaining to this genotype were distributed throughout most of Ulanqab and neighboring regions. The MLVA-16 scheme showed the presence of 69 genotypes, with 46 genotypes being represented by single isolates. This analysis revealed that Ulanqab brucellosis cases had epidemiologically unrelated and sporadic characteristics. The remaining 23 genotypes were shared (between a total of 70 isolates) with each genotype being represented by two to eight isolates. These data indicate that these cases were epidemiologically related. MLVA genotyping confirmed the occurrence of a multipoint outbreak epidemic and intrafamilial brucellosis. Extensive genotype-sharing events were observed among isolates from different regions of Ulanqab and from other provinces of China. These findings suggest either a lack of control of animal movement between different regions or the circulation of contaminated animal products in the market. Our study is the first comprehensive genotyping and genetic analysis of B. melitensis in Ulanqab. We believe that this study will help to improve the effectiveness of brucellosis control programs.

IMPORTANCEThe genetic basis of bipolar disorder (BD) in Han Chinese individuals is not fully understood.OBJECTIVE To explore the genetic basis of BD in the Han Chinese population. DESIGN, SETTING, AND PARTICIPANTSA genome-wide association study (GWAS), followed by independent replication, was conducted to identify BD risk loci in Han Chinese individuals. Individuals with BD were diagnosed based on DSM-IV criteria and had no history of schizophrenia, mental retardation, or substance dependence; individuals without any personal or family history of mental illnesses, including BD, were included as control participants. In total, discovery samples from 1822 patients and 4650 control participants passed quality control for the GWAS analysis. Replication analyses of samples from 958 patients and 2050 control participants were conducted. Summary statistics from the European Psychiatric Genomics Consortium 2 (PGC2) BD GWAS (20 352 cases and 31 358 controls) were used for the trans-ancestry genetic correlation analysis, polygenetic risk score analysis, and meta-analysis to compare BD genetic risk between Han Chinese and European individuals. The study was performed in February 2020.MAIN OUTCOMES AND MEASURES Single-nucleotide variations with P < 5.00 × 10 −8 were considered to show genome-wide significance of statistical association. RESULTS The HanChinese discovery GWAS sample included 1822 cases (mean [SD] age, 35.43 [14.12] years; 838 [46%] male) and 4650 controls (mean [SD] age, 27.48 [5.97] years; 2465 [53%] male), and the replication sample included 958 cases (mean [SD] age, 37.82 [15.54] years; 412 [43%] male) and 2050 controls (mean [SD] age, 27.50 [6.00] years; 1189[58%] male). A novel BD risk locus in Han Chinese individuals was found near the gene encoding transmembrane protein 108 (TMEM108, rs9863544; P = 2.49 × 10 −8 ; odds ratio [OR], 0.650; 95% CI, 0.559-0.756), which is required for dendritic spine development and glutamatergic transmission in the dentate gyrus. Trans-ancestry genetic correlation estimation (ρ ge = 0.652, SE = 0.106; P = 7.30 × 10 −10 ) and polygenetic risk score analyses (maximum liability-scaled Nagelkerke pseudo R 2 = 1.27%; P = 1.30 × 10 −19 ) showed evidence of shared BD genetic risk between Han Chinese and European populations, and meta-analysis identified 2 new GWAS risk loci near VRK2 (rs41335055; P = 4.98 × 10 −9 ; OR, 0.849; 95% CI, 0.804-0.897) and RHEBL1 (rs7969091; P = 3.12 × 10 −8 ; OR, 0.932; 95% CI, 0.909-0.956).CONCLUSIONS AND RELEVANCE This GWAS study identified several loci and genes involved in the heritable risk of BD, providing insights into its genetic architecture and biological basis.

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