Acanthopanax senticosus cultures fermented by Lactobacillus rhamnosus enhanced immune response through improvement of antioxidant activity and inflammation in crucian carp (Carassius auratus).

Lactic acid bacteria (LAB) have been recognized as safe microorganism that improve micro-flora disturbances and enhance immune response. A well-know traditional herbal medicine, Acanthopanax senticosus (As) was extensively utilized in aquaculture to improve growth performance and disease resistance. Particularly, the septicemia, skin wound and gastroenteritis caused by Aeromonas hydrophila threaten the health of aquatic animals and human. However, the effects of probiotic fermented with A. senticosus product on the immune regulation and pathogen prevention in fish remain unclear. Here, the aim of the present study was to elucidate whether the A. senticosus fermentation by Lactobacillus rhamnosus improve immune barrier function. The crucian carp were fed with basal diet supplemented with L. rhamnosus fermented A. senticosus cultures at 2 %, 4 %, 6 % and 8 % bacterial inoculum for 8 weeks. After trials, the weight gain rate (WGR), specific growth rate (SGR) were significantly increased, especially in LGG-6 group. The results confirmed that the level of the CAT, GSH-PX, SOD, lysozyme, and MDA was enhanced in fish received with probiotic fermented product. Moreover, the L. rhamnosus fermented A. senticosus cultures could trigger innate and adaptive immunity, including the up-regulation of the C3, C4, and IgM concentration. The results of qRT-PCR revealed that stronger mRNA transcription of IL-1ß, IL-10, IFN-γ, TNF-α, and MyD88 genes in the liver, spleen, kidney, intestine and gills tissues of fish treated with probiotic fermented with A. senticosus product. After infected with A. hydrophila, the survival rate of the LGG-2 (40 %), LGG-4 (50 %), LGG-6 (60 %), LGG-8 (50 %) groups was higher than the control group. Meanwhile, the pathological damage of the liver, spleen, head-kidney, and intestine tissues of probiotic fermentation-fed fish could be alleviated after pathogen infection. Therefore, the present work indicated that L. rhamnosus fermented A. senticosus could be regard as a potential intestine-target therapy strategy to protecting fish from pathogenic bacteria infection.

Transcriptomic insights into the immune response of the intestine to Aeromonas veronii infection in northern snakehead (Channa argus).

Intestinal inflammation is a protective response that is implicated in bacterial enteritis triggered by gastrointestinal infection. The immune mechanisms elicited in teleost against the infection of Aeromonas veronii are largely unknown. In this study, we performed a de novo northern snakehead (Channa argus) transcriptome assembly using Illumina sequencing platform. On this basis we performed a comparative transcriptomic analysis of northern snakehead intestine from A. veronii-challenge and phosphate buffer solution (PBS)-challenge fish, and 2076 genes were up-regulated and 1598 genes were down-regulated in the intestines infected with A. veronii. The Gene Ontology (GO) enrichment analysis indicated that the differentially expressed genes (DEGs) were enriched to 27, 21 and 20 GO terms in biological process, cellular component, and molecular function, respectively. A Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that 420 DEGs were involved in 194 pathways. Moreover, 33 DEGs were selected for quantitative real-time PCR analysis to validate the RNA-seq data. The results reflected the consistency of the expression levels between qRT-PCR and RNA-seq data. In addition, a time-course analysis of the mRNA expression of 33 immune-related genes further indicated that the intestinal inflammation to A. veronii infection simultaneously regulated gene expression alterations. The present study provides transcriptome data of the teleost intestine, allowing us to understand the mechanisms of intestinal inflammation triggered by bacterial pathogens. DATA AVAILABILITY STATEMENT: All data supporting the findings of this study are available within the article and Supplementary files. The RNA-seq raw sequence data are available in NCBI short read archive (SRA) database under accession number PRJNA615958.

Toxoplasma gondii infection in pet cats and their owners in northeastern China:an important public health concern.

BACKGROUND: Limited information about Toxoplasma gondii infection in pet cats and their owners is available in China. METHODS: In this study, blood samples were randomly collected from 306 pet cats and 397 corresponding pet owners in Jilin province, northeastern China. Sera from the pet cats and the pet owners were tested for anti-T. gondii antibodies using an modified agglutination test (MAT) and an enzyme-linked immunosorbent assay (ELISA), respectively. Moreover, the risk factors for T. gondii infection in pet cats and corresponding pet owners were explored. RESULT: In total, 62 sera out of 306 examined pet cats (20.3%) and 18.1% (72/397) pet cat owners were seropositive for T. gondii, respectively. The results of statistical analysis showed that both pet cats and their owners from rural area had significantly higher T. gondii seroprevalence than those from urban area (p < 0.001). Moreover, owners of pet cas who have the knowledge of zoonotic protozoan diseases had a significantly lower T. gondii seroprevalence than those without the knowledge of zoonotic protozoan diseases (p < 0.001). CONCLUSIONS: The present results revealed that the seroprevalence of T. gondii infection are widespread in pet cats and their owners in Jilin province, northeastern China. Residence area and understanding knowledge of zoonotic protozoan diseases are considered to be raleted to the T. gondii infection. Hence, it is necessary to highlight the dangers and protection methods of zoonotic protozoan diseases caused by pet cats, especially in rural area.

First detection of anti-Toxoplasma gondii antibodies in domestic goat's serum and milk during lactation in China.

Goat milk is considered as one of the most suitable substitute for human milk, especially for children, the aged and those with cow milk allergies. Consumption of raw or unpasteurized goat milk has been known to be a potential route of Toxoplasma gondii infection for human beings. However, no studies have been carried out to detect T. gondii in goat milk in China. Thus, this stuy was firstly carried out to detect T. gondii IgG antibody in domestic goat's serum and milk during lactation by a commercial validated ELISA kit in China. In total, 10.49% (66/629) serum samples and 9.70% (61/629) milk samples randomly collected from Shandong and Jilin provinces were seropositive for anti-T. gondii IgG, respectively. A high correlation of S/P% value was obtained between serum and milk samples (Spearman's coefficient = 0.891, p-value <0.001 and Kendall's tau = 0.724, p-value < 0.001). Statistical analysis showed that history of abortion, source of water and source of fodder were considered to be highly related to the T. gondii infection in the investigated domestic goats. The present results provide important information for the control and prevention of toxoplasmosis in goats and human beings in China.

Herd-level prevalence and associated risk factors for Toxoplasma gondii, Neospora caninum, Chlamydia abortus and bovine viral diarrhoea virus in commercial dairy and beef cattle in eastern, northern and northeastern China.

Although the seroprevalence of Toxoplasma gondii, Neospora caninum, Chlamydia abortus and bovine viral diarrhea virus infection in cattle have been reported in some areas in China, most of them were conducted with small number of cattle samples and very limited districts and neglected the assessment of herd management factors associated with herd-level prevalence of these pathogen infections. Thus, from September 2013 to December 2014, a large-scale seroprevalence study was conducted to determine the animal-level and herd-level seroprevalence and identify herd-level risk factors associated with these pathogen infections in 4487 cattle from 134 herds in five provinces (Heilongjiang, Jilin, Liaoning, Shandong, Hebei) and Inner Mongolia Autonomous Region of China. At animal level, the true prevalence of antibodies against T. gondii, N. caninum, C. abortus and bovine viral diarrhoea virus (BVDV) was 10.48, 17.14, 11.92 and 50.10%, respectively. At herd level, the true prevalence of antibodies against T. gondii, N. caninum, C. abortus and BVDV was 27.16, 29.10, 37.31 and 40.30%, respectively. Multivariate analysis of these characteristics showed that source of water and presence of felids were significantly associated with T. gondii infection in the studied cattle herds. Source of water was significantly associated with N. caninum infection in the studied cattle herds. While herd size and management system were significantly associated with BVDV infection in the studied cattle herds, this is the first report of herd-level prevalence and associated risk factors of T. gondii, N. caninum, C. abortus and BVDV infection in cattle in China.

Seroprevalence and risk factors associated with hepatitis E virus infection in three species of pet birds in northwest China.

Hepatitis E virus (HEV), the causative agent of hepatitis E, has been reported in a wide variety of animals, including birds, but little is known of HEV infection in pet birds in northwest China. The objective of the present investigation was to examine HEV seroprevalence in three species of pet birds, namely, Eurasian siskin, Oriental skylark, and black-tailed grosbeak from Gansu. Serum samples collected from 685 pet birds from August 2011 to September 2012 were examined independently for the presence of antibodies against HEV. A total of 59 (8.31%) pet birds were tested positive for HEV antibodies by the commercially available enzyme immunoassay kits. Of these, the seroprevalence was diverse in different species pet birds; the most frequent level was 10.83% (39/360) in Eurasian siskin, followed by 6.57% (19/289) in Oriental skylark, and 2.29% (1/36) in black-tailed grosbeak. Age and collecting region of pet birds were the main risk factors associated with HEV infection. The present study firstly revealed the seroprevalence of HEV infection in three species of pet birds in northwest China, which provided the baseline data for taking comprehensive countermeasures and measures for effectively preventing and controlling HEV infection in birds.

Toxoplasma gondii Antibodies in Raw Milk and Sera of Cows in China.

Toxoplasma gondii is a worldwide food-borne protozoa that has harmful influences on animal and human health. Raw milk containing T. gondii has been considered as one of the possible infectious sources for humans. Although China is one of the world's leading milk consumers, there is still no study to investigate the seroprevalence of T. gondii in raw cow milk in China; especially for cows in rural areas. Thus, we conducted this study to examine the specific anti-T. gondii IgG-antibody in the raw milk and sera of domestic cows in China. In total, 894 cows were randomly selected from rural areas in northeastern China. The positive rate of T. gondii in the milk and serum samples were 6.38% (57/894) and 7.16% (64/894), respectively. Moreover, a history of abortion (OR = 2.03, 95% CI: 1.11-3.72, p = 0.022) was identified as the only risk factor for T. gondii infection in the studied cows. This study investigated the seroprevalence of T. gondii in the raw milk and sera of cows in China; it provided timely and useful data for public health and food safety, especially in rural areas.

Comparative proteomic analysis reveals novel potential virulence factors of Aeromonas veronii.

Aeromonas veronii is an important zoonotic and aquatic pathogen. An increasing number of reports indicate that it has caused substantial economic losses in the aquaculture industry, in addition to threatening human health. However, little is known about its pathogenesis. Exploration of new virulence factors of A. veronii would be helpful for further understanding its pathogenesis. Hence, we comparatively analyzed the proteomes of virulent, attenuated, and avirulent strains of A. veronii using tandem mass tag (TMT) protein labeling and found numerous proteins either up- or downregulated in the virulent strain. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed that these differentially expressed proteins (DEPs) were involved mainly in pathways associated with bacterial chemotaxis and microbial metabolism in diverse environments. Furthermore, the expression levels of lysine decarboxylase, endoribonuclease, maltoporin, pullulanase, and aerolysin were positively correlated with the virulence of the strains, suggesting that their function may be closely related to the virulence of A. veronii. The results of qRT-PCR and multiple reaction monitoring for some DEPs were consistent with the results of TMT protein labeling. These results suggest that these DEPs may be novel potential virulence factors and will help to further understand the pathogenesis of A. veronii.

First Report of Chlamydia Seroprevalence in Slaughter Pigs in Shandong Province, Eastern China.

Chlamydia, a kind of obligate intracellular Gram-negative bacteria, can infect humans and animals worldwide, including pigs. However, the information on Chlamydia infection is unavailable in pigs in Shandong province, eastern China. To assess the seroprevalence and risk factors of Chlamydia infection in pigs in Shandong province, eastern China, a total of 2108 serum samples of slaughter pigs were collected between January 2017 and December 2018, and specific antibodies against Chlamydia were detected by the indirect hemagglutination assay. The overall Chlamydia seroprevalence was 24.15% (509/2108, 95% confidence interval: 22.32-25.97). Species, sampling regions, and rearing systems of pigs were considered as risk factors for Chlamydia infection through statistical analysis by SAS analysis (p < 0.05). These results indicated that Chlamydia is highly prevalent in slaughter pigs in Shandong province, eastern China, and may pose a potential risk for human health. To our knowledge, this is the first investigation of Chlamydia seroprevalence in slaughter pigs in Shandong province, eastern China. Moreover, this is the first report to compare the Chlamydia seroprevalence between domestic pigs and farmed wild boars in a same study, which may provide important data for preventing and controlling Chlamydia infection in pigs in China.

First Report of Toxoplasma gondii Infection in Common Quails (Coturnix coturnix) Intended for Human Consumption in Three Provinces of Northeastern China.

Common quails are nutritious food and are also used as medicine in some parts of the world. Until now, no information on Toxoplasma gondii infection in common quails intended for human consumption in China is available. Therefore, this study was carried out to determine the prevalence of T. gondii infection in common quails in six cities from Shandong, Liaoning, and Jilin provinces, China. Out of 620 common quails examined, 59 (9.52%) were seropositive for T. gondii by the modified agglutination test. T. gondii infection in male and female common quails was 8.10% and 10.71%, respectively. The highest prevalence (13.10%) was detected in a group of common quails from Rizhao of Shandong province, followed by common quails from Yantai of Shandong province (13.04%) and the lowest prevalence (5.56%) was detected in a group of common quails from Shenyang of Liaoning province. The results of this survey revealed the presence of T. gondii infection in common quails in China, indicating that common quails are a potential source for transmission of T. gondii to humans, therefore, posing a potential public health concern. To our knowledge, this is the first report of T. gondii infection in common quails in China.

Coxiella burnetii Seroprevalence and Risk Factors in Cattle Farmers and Farm Residents in Three Northeastern Provinces and Inner Mongolia Autonomous Region, China.

Little is known about Coxiella burnetii infection among cattle farmers and farm residents in China. Thus, the present study was conducted to detect the seroprevalence of C. burnetii infection and estimate associated risk factors among cattle farmers and farm residents in China. A cross-sectional study was designed, and sera of 362 people living or working on 106 cattle farms were tested for C. burnetii IgG and IgM antibodies by immunofluorescence assay. Overall C. burnetii seroprevalence was 35.6% (129/362, 95% CI: 30.70-40.57), and 112 participants had experienced a past infection and seventeen (4.7%) had experienced a relatively recent infection. In the final combined multilevel model, the following activities were significantly associated with presence of antibodies against C. burnetii: milking cattle, providing general healthcare to cattle, providing birth assistance, contact dead-born animals, urbanization, and presence of mice and/or rats in the stable. Moreover, presence of disinfection equipment was a significant protective factor. This is the first study addressing the seroprevalence and risk factors of C. burnetii infection in cattle farmers and farm residents in three northeastern provinces and Inner Mongolia Autonomous Region, China.

First report of Toxoplasma gondii Seroprevalence in Farmed Arctic Foxes (Vulpes lagopus) in Eastern and Northeastern China.

Until now, no information on Toxoplasma gondii seroprevalence in Arctic foxes (Vulpes lagopus) was available in China. A serological survey was undertaken to assess T. gondii seroprevalence in farmed Arctic foxes in eastern and northeastern China. Antibodies to T. gondii were examined in 1346 farmed Arctic foxes using the modified agglutination test (MAT). A total of 113 (8.39%, 95% confidence interval [CI] 6.91-9.87) serum samples were positive to T. gondii at a 1:25 cutoff. Seroprevalence of T. gondii infection in male Arctic foxes was 8.68% (95% CI 6.75-10.6), which was higher than that in the female Arctic foxes (7.95%, 95% CI 5.65-10.26). The prevalence in polar foxes was 7.07% (95% CI 5.14-8.99), which was lower than that in the blue foxes (9.75%, 95% CI 7.49-11.99). T. gondii seroprevalence in Arctic foxes in Heilongjiang, Jilin, Liaoning, and Shandong Provinces was 9.85% (95% CI 5.75-13.95), 9.21% (95% CI 5.54-12.87), 7.37% (95% CI 5.22-9.51), and 8.68% (95% CI 5.66-11.70), respectively. There were no statistically significant differences between T. gondii seroprevalence and morphs, sex, or regions of Arctic foxes in logistic regression analysis (p < 0.05). The results of the present survey indicated that T. gondii infection in farmed Arctic foxes is prevalent in China. To our knowledge, this is the first report of T. gondii seroprevalence in Arctic foxes in China.

Coxiella burnetii (Q fever) Infection in Farmed Ruminants in Three Northeastern Provinces and Inner Mongolia Autonomous Region, China.

Coxiella burnetii is the pathogenic agent of Q fever, a zoonosis that occurs worldwide. In China, the organism infects people and a wide range of wild and farmed animals. However, little is known about C. burnetii infection in farmed ruminants in northeastern China, and there appears to have been no previous study on sika deer. The present study was conducted to determine the seroprevalence of C. burnetii in farmed ruminants in this region of China. A total of 3147 domestic ruminants (784 sheep, 1016 cattle, and 1347 sika deer) were randomly collected for this study. An indirect enzyme-linked immunosorbent assay kit was used to detect the antibodies to C. burnetii. The results showed an overall seroprevalence of 16.7% in domestic ruminants (24.9%, 13.5%, and 12.3% in cattle, sheep, and sika deer, respectively). This is the first report of C. burnetii seroprevalence in sika deer in China. Protective and hygiene measures should be applied in farm management to reduce the risk of exposure of C. burnetii to humans.

Mycobacterium avium Subspecies paratuberculosis and Bovine Leukemia Virus Seroprevalence and Associated Risk Factors in Commercial Dairy and Beef Cattle in Northern and Northeastern China.

Mycobacterium avium subspecies paratuberculosis (MAP) and bovine leukemia virus (BLV) are important pathogens, commonly responsible for economical loss to cattle farms all over the world, yet their epidemiology in commercial dairy and beef cattle in China is still unknown. Thus, from September 2013 to December 2014, a large-scale seroprevalence study was conducted to determine the seroprevalence and identify herd-level risk factors associated with MAP and BLV infection. The source sample was 3674 cattle from 113 herds in northern and northeastern China. Antibodies against MAP and BLV were detected using ELISA tests. At animal-level, the seroprevalence of antibodies against MAP and BLV was 11.79% (433/3674) and 18.29% (672/3674), respectively. At herd-level, the seroprevalence of antibodies against MAP and BLV was 20.35% and 21.24% (24/113), respectively. Herd size was identified to be associated with MAP infection while herd size and presence of cattle introduced from other farms were significantly associated with BLV infection. Further research is needed to confirm these findings and improve the knowledge of the epidemiology of these two pathogens in these regions and elsewhere in China.