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Background: The prevalence of human brucellosis in Qinghai Province of China has been increasing rapidly, with confirmed cases distributed across 31 counties. However, the epidemiology of brucellosis transmission has not been fully elucidated. To characterize the infecting strains isolated from humans, multiple-locus variable-number tandem repeats analysis (MLVA) and whole-genome single-nucleotide polymorphism (SNP)-based approaches were employed., Methods: Strains were isolated from two males blood cultures that were confirmed Brucella melitensis positive following biotyping and MLVA. Genomic DNA was extracted from these two strains, and whole-genome sequencing was performed. Next, SNP-based phylogenetic analysis was performed to compare the two strains to 94 B. melitensis strains (complete genome and draft genome) retrieved from online databases., Results: The two Brucella isolates were identified as B. melitensis biovar 3 (QH2019001 and QH2019005) following conventional biotyping and were found to have differences in their variable number tandem repeats (VNTRs) using MLVA-16. Phylogenetic examination assigned the 96 strains to five genotype groups, with QH2019001 and QH2019005 assigned to the same group, but different subgroups. Moreover, the QH2019005 strain was assigned to a new subgenotype, IIj, within genotype II. These findings were then combined to determine the geographic origin of the two Brucella strains., Conclusions: Utilizing a whole-genome SNP-based approach enabled differences between the two B. melitensis strains to be more clearly resolved, and facilitated the elucidation of their different evolutionary histories. This approach also revealed that QH2019005 is a member of a new subgenotype (IIj) with an ancient origin in the eastern Mediterranean Sea.

Objective: To analyze the epidemiological and molecular characteristics of human brucellosis in Qinghai province from 2005 to 2019 and provide basic data for brucellosis prevention and control. Method: The data about human brucellosis in Qinghai from 2005 to 2019 were collected from the information system of China CDC to describe the spatial, population and time distributions of human brucellosis cases in Qinghai. The isolated strains were identified and typed with traditional methods, BCSP31-PCR, AMOS-PCR and multi-locus variablenumber tandem repeat (MLVA-16). Results: A total of 577 human brucellosis cases were reported in Qinghai from 2005 to 2019, the average prevalence rate was 0.07 per 100 000 person, there were statistic differences among different years. The disease occurred all the year around, but mainly during March-October. The 577 cases were distributed in 31 counties (cities/districts) from 6 autonomous prefectures (cities). The prevalence rats of five counties were high, i.e. Menyuan Hui autonomous county (22.88 % , 132/577), Tianjun county (10.57 % , 61/577)、Xining city (10.57 % , 61/577), Henan Mongol Autonomous County (10.51 % , 58/577) and Haiyan county (9.53 % , 55/577). Age of the cases ranged from 8 years to 82 years, and the male to female ratio of the cases was 1.8∶1 (374/203). The prevalence rate in herdsman (47.83 %, 276/577) was highest among different occupational populations. Ten isolates were all Brucella melitensis strains, belonging to biovar 3, and clustering analysis indicated that the 10 strains had 5 genotypes, in which 2 were distinct, the remaining 3 were same. MLVA-16 analysis indicated that the 10 strains had close relationship with 26 B. melitensis strains isolated in Qinghai previously. Conclusions: The prevalence of brucellosis increased in Qinghai in recent years, we should strengthen the population based brucellosis surveillance and reporting. MLVA-16 indicated the gene diversity of the Brucella strains, suggesting that MLVA-16 can be used for genetic diversity analysis and molecular epidemiology survey to improve brucellosis surveillance.

Background: Brucellosis is an important public health problem in China. Brucellosis can cause many osteoarticular changes, especially chronic brucellosis. Brucellosis presents various diagnostic difficulties because it mimics many other diseases. Because of the poor sensitivity and ability of X-ray image, it is necessary to find a good method of early diagnosis for osteoarticular changes among brucellosis patients at an early period. The aim of this study was to find early changes biomarkers for osteoarticular changes among brucellosis patients at an early period and provide a better understanding of the osteoarticular changes in this disease at an early stage., Methods: Sixty-one cases of brucellosis patients at an early period (within 6 months) and 67 cases of volunteers were selected and divided into brucellosis vs. control groups. Serum samples were detected with serological tests for brucellosis, including rose bengal plate test (RBPT), agglutination test (SAT), and IgG and IgM with ELISA. Meanwhile, cartilage oligomeric matrix protein (COMP) and neopterin (NPT) levels in all samples were measured simultaneously with ELISA. The data were analyzed using SPSS 17.0 software., Results: Together with the clinical examination, epidemiological investigation, and serological tests of RBPT, SAT, and IgG and IgM with ELISA, the patients from brucellosis group all were diagnosed as brucellosis cases at an early period, while the results of RBPT, SAT, and IgG and IgM with ELISA from the healthy control group were negative. Comparing with the healthy control, the medians of serum NPT and COMP in the patients group were 9.26 ng/l, 1.70 ng, respectively, which were higher than that of the healthy control group with significant differences (Z = 5.512, 3.614, all p = 0.000)., Conclusion: The serum NPT and COMP levels of brucellosis patients at an early period were increased. The serum NPT and COMP levels might be the indicator biomarker for osteoarticular changes of human brucellosis at an early stage.

Background: Brucellosis incidence in China is divided into three stages: high incidence (1950s-1960s), decline (1970s-1980s), and re-emergence (1990s-2010s). At the re-emergence stage, Brucellosis incidence grew exponentially and spread to all 32 provinces. We describe the magnitude and the etiological distribution changes in mainland China by genotyping data and emphasize its recent reemergence. We also provide the genetic diversity and molecular epidemiological characteristics of Brucella., Results: From a total of 206 Brucella isolates, 19 MLST genotypes (STs) were identified and 13 new STs(ST71-83)were found. MLST grouped the population into three clusters. B. melitensis, B. abortus and B. suis were grouped into cluster 1, 2 and 3 respectively. The predominant genotype in the first cluster by MLST, remained unchanged during the three stages. However, the proportion of genotypes in the three stages had changed. More isolates were clustered in ST8 at the re-emergence stage. STs71-74, which were not found in the two former stages, appeared at the re-emergence stage., Conclusions: The changing molecular epidemiology of brucellosis improve our understanding of apparent geographic expansion from the historically affected north of China to southern provinces in recent reemergence.

Background: Brucellosis was a common human and livestock disease caused by Brucella strains, the category B priority pathogens by the US Center for Disease Control (CDC). Identified as a priority disease in human and livestock populations, the increasing incidence in recent years in China needs urgent control measures for this disease but the molecular background important for monitoring the epidemiology of Brucella strains at the national level is still lacking., Methods: A total of 600 Brucella isolates collected during 60 years (from 1953 to 2013) in China were genotyped by multiple locus variable-number tandem repeat analysis (MLVA) and the variation degree of MLVA11 loci was calculated by the Hunter Gaston Diversity Index (HGDI) values. The charts and map were processed by Excel 2013, and cluster analysis and epidemiological distribution was performed using BioNumerics (version 5.1)., Results: The 600 representative Brucella isolates fell into 104 genotypes with 58 singleton genotypes by the MLVA11 assay, including B. melitensis biovars 2 and 3 (five main genotypes), B. abortus biovars 1 and 3 (two main genotypes), B. suis biovars 1 and 3 (three main genotypes), and B. canis (two main genotypes) respectively. While most B. suis biovar 1 and biovar 3 were respectively found in northern provinces and southern provinces, B. melitensis and B. abortus strains were dominant in China. Canine Brucellosis was only found in animals without any human cases reported. Eight Brucellosis epidemic peaks emerged during the 60 years between 1953 and 2013: 1955 - 1959, 1962 - 1969, 1971 - 1975, 1977 - 1983, 1985 - 1989, 1992 - 1997, 2000 - 2008 and 2010 - 2013 in China., Conclusions: Brucellosis has its unique molecular epidemiological patterns with specific spatial and temporal distribution according to MLVA., Trial Registration: IDOP-D-16-00101.

Background: The Qinghai-Tibet Plateau (QTP) of China is an extensive pastoral and semi-pastoral area, and because of poverty and bad hygiene conditions, Brucella is highly prevalent in this region. In order to adequately prevent this disease in the QTP region it is important to determine the identity of Brucella species that caused the infection., Methods: A total of 65 Brucella isolates were obtained from human, livestock and wild animals in Qinghai, a Chinese province in east of the QTP. Two molecular typing methods, MLVA (multi-locus variable-number tandem-repeat analysis) and MLST (multi locus sequence typing) were used to identify the species and genotypes of these isolates., Findings: Both MLVA and MLST typing methods classified the 65 isolates into three species, B. melitensis, B. abortus and B. suis, which included 60, 4 and 1 isolates respectively. The MLVA method uniquely detected 34 (Bm01 ~ Bm34), 3 (Ba01 ~ Ba03), and 1 (Bs01) MLVA-16 genotypes for B. melitensis, B. abortus and B. suis, respectively. However, none of these genotypes exactly matched any of the genotypes in the Brucella2012 MLVA database. The MLST method identified five known ST types: ST7 and ST8 (B. melitensis), ST2 and ST5 (B. abortus), and ST14 (B. suis). We also detected a strain with a mutant type (3-2-3-2-?-5-3-8-2) of ST8 (3-2-3-2-1-5-3-8-2). Extensive genotype-sharing events could be observed among isolates from different host species., Conclusions: There were at least three Brucella (B. melitensis, B. abortus and B. suis) species in Qinghai, of which B. melitensis was the predominant species in the area examined. The Brucella population in Qinghai was very different from other regions of the world, possibly owing to the unique geographical characteristics such as extremely high altitude in QTP. There were extensive genotype-sharing events between isolates obtained from humans and other animals. Yaks, sheep and blue sheep were important zoonotic reservoirs of brucellosis causing species found in humans.

Brucellosis is one of the most widespread zoonotic diseases, with the most frequent complication being osteoarticular changes. The aim of this study was to assess the changes of C-terminal telopeptide of type II collagen (CTX-II) in patients infected with brucellosis. A total of 84 brucellosis patients and 43 volunteers were selected and divided into brucellosis vs. control groups. Serum samples were subjected to serological tests for brucellosis, and CTX-II levels in all samples were measured simultaneously with ELISA. The results showed that serum CTX-II levels in human brucellosis were higher than those of healthy controls, without a statistically significant difference, but serum CTX-II levels in male patients were significantly higher than those of female patients (P<0.05). This finding could indicate the biological changes in the cartilage and bone in human brucellosis., (Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.)