Prevalence of Mycobacterium bovis in deer in mainland China: a systematic review and meta-analysis.

Background: Deer tuberculosis is a chronic zoonotic infectious disease, despite the existence of socio-economic and zoonotic risk factors, but at present, there has been no systematic review of deer tuberculosis prevalence in mainland China. The aim of this meta-analysis was to estimate the overall prevalence of deer TB in mainland China and to assess possible associations between potential risk factors and the prevalence of deer tuberculosis. Methodology: This study was searched in six databases in Chinese and English, respectively (1981 to December 2023). Four authors independently reviewed the titles and abstracts of all retrieved articles to establish the inclusion exclusion criteria. Using the meta-analysis package estimated the combined effects. Cochran's Q-statistic was used to analyze heterogeneity. Funnel plots (symmetry) and used the Egger's test identifying publication bias. Trim-and-fill analysis methods were used for validation and sensitivity analysis. we also performed subgroup and meta-regression analyses. Results: In this study, we obtained 4,400 studies, 20 cross-sectional studies were screened and conducted a systematic review and meta-analysis. Results show: The overall prevalence of tuberculosis in deer in mainland China was 16.1% (95% confidence interval (CI):10.5 24.6; (Deer tuberculosis infected 5,367 out of 22,215 deer in mainland China) 5,367/22215; 1981 to 2023). The prevalence in Central China was the highest 17.5% (95% CI:14.0-21.9; 63/362), and among provinces, the prevalence in Heilongjiang was the highest at 26.5% (95% CI:13.2-53.0; 1557/4291). Elaphurus davidianus was the most commonly infected species, with a prevalence of 35.3% (95% CI:18.5-67.2; 6/17). We also assessed the association between geographic risk factors and the incidence of deer tuberculosis. Conclusion: Deer tuberculosis is still present in some areas of China. Assessing the association between risk factors and the prevalence of deer tuberculosis showed that reasonable and scientific-based breeding methods, a suitable breeding environment, and rapid and accurate detection methods could effectively reduce the prevalence of deer tuberculosis. In addition, in the management and operation of the breeding base, improving the scientific feed nutrition standards and establishing comprehensive standards for disease prevention, immunization, quarantine, treatment, and disinfection according to the breeding varieties and scale, are suggested as ways to reduce the prevalence of deer tuberculosis.

Mycobacterium tuberculosis Rv3435c regulates inflammatory cytokines and promotes the intracellular survival of recombinant Mycobacteria.

Mycobacterium tuberculosis is a pathogenic bacterium that is parasitic in macrophages and show high adaptation to the host's immune response. It can also trigger a complex immune response in the host. This relies on proteins encoded by a series of M. tuberculosis-encoded virulence genes. We found that the M. tuberculosis Rv3435c gene is highly conserved among pathogenic mycobacteria, and might be a virulence gene. To explore the gene function of Rv3435c, we used Mycobacterium smegmatis to construct a recombinant mycobacterium expressing Rv3435c heterologously. The results that Rv3435c is a cell wall-related protein that changes bacterial and colony morphology, inhibits the growth rate of recombinant mycobacteria, and enhances their resistance to various stresses. We also found that the fatty acid levels of the recombinant strain changed. Simultaneously, Rv3435c can inhibit the expression and secretion of inflammatory factors and host cell apoptosis, and enhance the survival of recombinant bacteria in macrophages. Experimental data indicated that Rv3435c might play an important role in Mycobacterium tuberculosis infection.

The effect of fibroblast growth factor 21 on a mouse model of bovine viral diarrhea.

Previously, we researched that bovine viral diarrhea virus (BVDV) induced a very significant increase in fibroblast growth factor 21 (FGF21) expression in mouse liver and that FGF21 was increased in the peripheral blood of BVD cattle and BVD mice. To determine the role of FGF21 in relieving clinical symptoms and inhibiting the intestinal damage caused by BVDV in BVD development in mice, BALB/c mice were intraperitoneally injected with cytopathic biotype (cp) BVDV-LS01 (isolated and identified by our group) to establish a BVD mouse model. The role of FGF21 in the BVD mouse model was investigated by injecting the mice with FGF21. The animals were divided into control, BVDV challenge, BVDV + FGF21, BVDV + FGF21Ab (anti-FGF21 antibody), and BVDV + IgG (immunoglobulin G) groups. The stool consistency, the degree of bloody diarrhea, histopathological changes, inflammatory cell infiltration, weight loss percentage, and detection of BVDV in the feces of the mice were examined, and the pathological changes and inflammatory cytokine expression were analyzed. The results showed that after BVDV challenge, the average BVD mouse model score of the BVDV mice was 11.6 points. In addition to mild diarrhea and tissue damage, BVDV was detected in the stools of 13 BVDV mice. Only two mice in the control group had scores (both, 1 point each). The comprehensive scoring results demonstrated the successful establishment of the BVD mouse model. FGF21 alleviated the clinical symptoms in the BVD mice and significantly improved weight loss. Furthermore, FGF21 inhibited the BVDV-induced leukocyte, platelet, and lymphocyte reduction while inhibiting the expression of BVDV-induced inflammatory factors. In the BVD mice, FGF21 promoted duodenal epithelial cell proliferation, thereby significantly improving the damage to the cells. In conclusion, FGF21 exerted a good therapeutic effect on the BVD mouse model.

Settleability and dewaterability of sewage sludge with modified diatomite.

In this study, cationic polyacrylamide (CPAM)-modified diatomite and cetyl trimethyl ammonium bromide (CTAB)-modified diatomite were synthesized and used as conditioners for sewage sludge dewatering. The effects of these two types of modified diatomite on the dewaterability and settling performance of the activated sludge were studied. The mechanisms of the two modified diatomite types in the activated sludge system were elucidated. The efficiency of the CPAM-modified diatomite was better than that of the CTAB-modified diatomite in improving the settleability and dewaterability of sludge. The results indicated that specific resistance to filtration (SRF) was decreased from 8.52 × 1012 to 0.92 × 1012 m/Kg, and the water content in the remaining sludge cake after pumping filtration was decreased from 92.2 to 68.1% by adding 0.4% of CPAM-modified diatomite and pH = 3.5, which resulted in excellent sludge settling of activated sludge. Further studies showed that the polymer/surfactant adsorbed in diatomite increased sludge dewaterability and improved the sedimentation rate owing to stripping extracellular polymeric substances (EPS) and damaging the internal structure of the sludge, leading to sludge conduce bound water release. According to scanning electron microscope (SEM) images, the two types of modified diatomite powder maintained the porous structure and showed a more complete and uniform structure compared to natural diatomite.

Brucellosis prevalence in yaks in China in 1980-2019: A systematic review and meta-analysis.

In the Qinghai-Tibet Plateau of China, the yak is an animal of particular economic interest, which provides protein and income for herders in daily life. Brucellosis is a bacterial disease that can infect humans and animals, including yaks. It can damage the yak reproductive system, causing miscarriage and orchitis. At the same time, brucellosis threatens the health of herders. We performed this meta-analysis using R software to explore the combined prevalence and risk factors of brucellosis in yak in China. Variability was assessed by the I2 statistic and Cochran Q statistic. We identified 52 publications of related research from four databases (Wanfang Data, VIP Chinese Journal Database, China National Knowledge Infrastructure, and of PubMed). The pooled prevalence of yak brucellosis was 8.39 %. Prevalence was highest in Southwestern China (11.1 %). The point estimate of brucellosis in yak from 2012 to 2016 was the highest (11.47 %). The point estimate of age ≤ 12 months (1.44 %) was lower than that of age > 12 months (15.6 %). This study shows that yak brucellosis is serious, and its incidence is higher than before 2012. We recommend carrying out large-scale yak brucellosis investigations in Western China and conducting comprehensive testing planning. The detection of brucellosis in adult animals should be strengthened to reduce the economic loss caused by brucellosis to herders and to improve public health.

Prevalence of bovine tuberculosis in dairy cattle in China during 2010-2019: A systematic review and meta-analysis.

BACKGROUND: Bovine tuberculosis (bTB), caused by members of the Mycobacterium tuberculosis complex bacteria, mainly Mycobacterium bovis (M. bovis), is a major threat to public health and economic development. There has been no systematic epidemiological assessment concerning bTB in dairy cattle in China. METHODOLOGY/PRINCIPAL FINDINGS: Literature related to bTB in China was retrieved from China National Knowledge Infrastructure (CNKI), PubMed, ScienceDirect, VIP Chinese Journals Database, and Wan Fang Database to build the first meta-analysis for estimating the prevalence and infection moderators of bTB in dairy cattle in China. A total of 100 relevant studies published from 2010 to 2019 were included. We estimated the overall prevalence of bTB was 2.4% (95% CI: 2.1-2.8) during this decade. In the sampling year subgroup, the prevalence was lowest in 2017 or later at 0.8% (95% CI: 0.3-1.5). The lowest prevalence was 0.7% (95% CI: 0.5-1.0) in Northwestern China. The lowest prevalence was 2.1% (95% CI: 1.8-2.5) using SIT test. Heifer cows had the highest prevalence, which was 27.1% (95% CI: 9.7-49.2). The prevalence in scale farming was 3.7% (95% CI: 3.1-4.3), significantly higher than that in free-range farming (1.7%, 95% CI: 1.1-2.4). The prevalence of bTB was highest in summer at 4.0% (95% CI: 1.7-7.0). In addition, the influence of different geographical factors (altitude, longitude, latitude, precipitation, temperature, humidity) on the prevalence was analyzed. CONCLUSIONS/SIGNIFICANCE: The results showed that bTB was widespread in China but has been gradually reduced through concerted national intervention. It is suggested that different countries should formulate corresponding prevention and control measures according to the epidemic situation in its cattle industry. Enhanced monitoring of warm and humid areas may play an important role in reducing the incidence of bTB. In addition, when large-scale breeding is promoted, attention should be paid to standardizing breeding management and improving animal welfare to reduce the prevalence of bTB in cattle.

Prevalence of Bovine Tuberculosis in Yaks Between 1982 and 2020 in Mainland China: A Systematic Review and Meta-Analysis.

Bovine tuberculosis (bTB) is a major chronic bacterial disease in cattle and is the major economic and animal welfare issue in the world. Although the economic costs and public health safety risks associated with the disease are considerable, the overall epidemiology of the Chinese yak (Bos grunniens) bTB is unclear. To fully reveal the basic prevalence of yak bTB in different regions of China, we searched five databases including PubMed, Science Direct, CNKI (China National Knowledge Infrastructure), Wanfang and Chongqing VIP. Based on the incidence and prevalence of yak tuberculosis in China from 1982 to 2020, a meta-analysis of yak bTB in China was established for the first time. By formulating the search formula, 97 studies were searched in five databases. According to the established exclusion criteria and excluded comments and repeated and irrelevance research, we finally selected 19 cross-sectional studies, which showed the prevalence of bTB in Chinese yaks. Random-effect meta-regression model analysis showed that the estimated prevalence of 122,729 yaks in China was 1.0 (95% confidence interval [CI]: 0.0-1.0). The regional prevalence varies greatly, northwest China prevalence rate 0. 39% (95% CI: 0.2-0. 64) and southwest China prevalence rate 2.59% (95% CI: 1.94-3.34); in terms of province level, the prevalence was highest in Tibet 2.59% (95% CI: 1.94-3.34), followed by Xinjiang 2.36% (95% CI: 0.86-4.58), and Shanxi has the lowest 0.00% (95% CI: 0.00-0.98). This systematic review and meta-analysis identified the estimated prevalence of bTB in Chinese yaks and estimated the underlying factors associated with bTB, including geographic location, sampling year, age, and TB detection method. Provide evidence to plan corresponding disease control strategies for policymakers and to assess future economic risks accurately.

Mink Aleutian disease seroprevalence in China during 1981-2017: A systematic review and meta-analysis.

Mink Aleutian disease (AMD) is the first of the three major diseases of fur animals. It is a common immunosuppressive disease in mink farms worldwide, which seriously endangers the development of the mink farming industry. Strengthening the understanding of the positive serum rate and spatial distribution of AMD is of great significance for the prevention and control of disease caused by the Aleutian virus. Therefore, we conducted a systematic review and meta-analysis to assess the seroprevalence of AMD in China. We extracted 45 studies related to the seroprevalence of Chinese AMD, with samples taken between 1981 and 2017. Our systematic review and meta-analysis results show that, during the selected period, the overall positive rate of AMD in China was 55.3% (95% CI 48.5-62.0). The results from subgroups analysis of the potential risk factors showed that the seroprevalence rate of AMD in China in the past 36 years rose from 48% (95% CI 37.0-60.5) in 1981-2009 to 61.4% (95% CI 43.6-79.3) in 2010-2017. The date of the spatial difference in AMD seroprevalence indicated that AMD seroprevalence was unevenly distributed in different regions: the number of mink in eastern China and northeastern China was relatively high, and the seroprevalence rates were 57.9%, (95% CI 46.2-69.7) and 61.3% (95% CI 53.1-69.5), respectively. Central China had the highest seroprevalence rate of AMD at 69.8% (95% CI 64.4-75.2). At the provincial level, the AMD seroprevalence rate in Jiangsu was as high as 96% (95% CI 94.1-97.8), and the AMD seroprevalence rate in Shaanxi was the lowest at 22.1% (95% CI 20.3-23.9). This suggested that the AMD seroprevalence rate in China was unevenly distributed. In other subgroups, the positive rate of AMD in adult mink was higher than in juvenile mink. This implied that the high prevalence of AMD in China was caused by multiple factors. The meta-regression results indicated that the detection method subgroup (P = 0.008) may be the source of heterogeneity. Our data system evaluated the prevalence of Aleutian disease in China in the last 37 years and a preliminary discussion on the risk factors of AMD. It may help prevent and control AMD in China. It is recommended to conduct further epidemiological testing and develop a comprehensive testing plan to determine the risk factors associated with Aleutian disease and improve the Aleutian disease control strategy.