Improving resilience to high temperature in drought: water replenishment enhances sucrose and amino acid metabolisms in maize grain.

Heat stress poses a significant threat to maize, especially when combined with drought. Recent research highlights the potential of water replenishment to ameliorate grain weight loss. However, the mitigating mechanisms of heat in drought stress, especially during the crucial early grain-filling stage, remain poorly understood. We investigated the mechanism for mitigating heat in drought stress by water replenishment from the 12th to the 32nd days after silking in a controlled greenhouse experiment (Exp. I) and field trial (Exp. II). A significant reduction in grain weight was observed in heat stress compared to normal conditions. When water replenishment was applied to increase soil water content (SWC) under heat stress, the grain yield exhibited a notable increase ranging from 28.4 to 76.9%. XY335 variety was used for transcriptome sequencing to analyze starch biosynthesis and amino acid metabolisms in Exp. I. With water replenishment, the transcripts of genes responsible for trehalose 6-phosphate phosphates (TPP), alpha-trehalase (TRE), ADP-glcpyrophosphorylase, and starch synthase activity were stimulated. Additionally, the expression of genes encoding TPP and TRE contributed to an enhanced conversion of trehalose to glucose. This led to the conversion of sucrose from glucose-1-phosphate to ADP-glucose and ADP-glucose to amylopectin, ultimately increasing starch production by 45.1%. Water replenishment to boost SWC during heat stress also elevated the levels of essential amino acids in maize, including arginine, serine, tyrosine, leucine, glutamic acid, and methionine, providing valuable support to maize plants in adversity. Field trials further validated the positive impact of water replenishment on SWC, resulting in a notable increase in grain yield ranging from 7.1 to 9.2%. This study highlights the vital importance of adapting to abiotic stress and underscores the necessity of developing strategies to counteract its adverse effects on crop yield.

A steady-state N balance approach for sustainable smallholder farming.

Hundreds of millions of smallholders in emerging countries substantially overuse nitrogen (N) fertilizers, driving local environmental pollution and global climate change. Despite local demonstration-scale successes, widespread mobilization of smallholders to adopt precise N management practices remains a challenge, largely due to associated high costs and complicated sampling and calculations. Here, we propose a long-term steady-state N balance (SSNB) approach without these complications that is suitable for sustainable smallholder farming. The hypothesis underpinning the concept of SSNB is that an intensively cultivated soil-crop system with excessive N inputs and high N losses can be transformed into a steady-state system with minimal losses while maintaining high yields. Based on SSNB, we estimate the optimized N application range across 3,824 crop counties for the three staple crops in China. We evaluated SSNB first in ca. 18,000 researcher-managed on-farm trials followed by testing in on-farm trials with 13,760 smallholders who applied SSNB-optimized N rates under the guidance of local extension staff. Results showed that SSNB could significantly reduce N fertilizer use by 21 to 28% while maintaining or increasing yields by 6 to 7%, compared to current smallholder practices. The SSNB approach could become an effective tool contributing to the global N sustainability of smallholder agriculture.

Antibody Binding Epitope Mapping (AbMap) of Hundred Antibodies in a Single Run.

Antibodies play essential roles in both diagnostics and therapeutics. Epitope mapping is essential to understand how an antibody works and to protect intellectual property. Given the millions of antibodies for which epitope information is lacking, there is a need for high-throughput epitope mapping. To address this, we developed a strategy, Antibody binding epitope Mapping (AbMap), by combining a phage displayed peptide library with next-generation sequencing. Using AbMap, profiles of the peptides bound by 202 antibodies were determined in a single test, and linear epitopes were identified for >50% of the antibodies. Using spike protein (S1 and S2)-enriched antibodies from the convalescent serum of one COVID-19 patient as the input, both linear and potentially conformational epitopes of spike protein specific antibodies were identified. We defined peptide-binding profile of an antibody as the binding capacity (BiC). Conceptually, the BiC could serve as a systematic and functional descriptor of any antibody. Requiring at least one order of magnitude less time and money to map linear epitopes than traditional technologies, AbMap allows for high-throughput epitope mapping and creates many possibilities.

Functional Characterization of the Cystine-Rich-Receptor-like Kinases (CRKs) and Their Expression Response to Sclerotinia sclerotiorum and Abiotic Stresses in Brassica napus.

Cysteine-rich receptor-like kinases (CRKs) are transmembrane proteins that bind to the calcium ion to regulate stress-signaling and plant development-related pathways, as indicated by several pieces of evidence. However, the CRK gene family hasn't been inadequately examined in Brassica napus. In our study, 27 members of the CRK gene family were identified in Brassica napus, which are categorized into three phylogenetic groups and display synteny relationship to the Arabidopsis thaliana orthologs. All the CRK genes contain highly conserved N-terminal PKINASE domain; however, the distribution of motifs and gene structure were variable conserved. The functional divergence analysis between BnaCRK groups indicates a shift in evolutionary rate after duplication events, demonstrating that BnaCRKs might direct a specific function. RNA-Seq datasets and quantitative real-time PCR (qRT-PCR) exhibit the complex expression profile of the BnaCRKs in plant tissues under multiple stresses. Nevertheless, BnaA06CRK6-1 and BnaA08CRK8 from group B were perceived to play a predominant role in the Brassica napus stress signaling pathway in response to drought, salinity, and Sclerotinia sclerotiorum infection. Insights gained from this study improve our knowledge about the Brassica napus CRK gene family and provide a basis for enhancing the quality of rapeseed.

Nsp2 has the potential to be a drug target revealed by global identification of SARS-CoV-2 Nsp2-interacting proteins.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health threat since December 2019, and there is still no highly effective drug to control the pandemic. To facilitate drug target identification for drug development, studies on molecular mechanisms, such as SARS-CoV-2 protein interactions, are urgently needed. In this study, we focused on Nsp2, a non-structural protein with largely unknown function and mechanism. The interactome of Nsp2 was revealed through the combination of affinity purification mass spectrometry (AP-MS) and stable isotope labeling by amino acids in cell culture (SILAC), and 84 proteins of high-confidence were identified. Gene ontology analysis demonstrated that Nsp2-interacting proteins are involved in several biological processes such as endosome transport and translation. Network analysis generated two clusters, including ribosome assembly and vesicular transport. Bio-layer interferometry (BLI) assay confirmed the bindings between Nsp2- and 4-interacting proteins, i.e. STAU2 (Staufen2), HNRNPLL, ATP6V1B2, and RAP1GDS1 (SmgGDS), which were randomly selected from the list of 84 proteins. Our findings provide insights into the Nsp2-host interplay and indicate that Nsp2 may play important roles in SARS-CoV-2 infection and serve as a potential drug target for anti-SARS-CoV-2 drug development.

The binding epitope of sintilimab on PD-1 revealed by AbMap.

PD-1 plays an important role as an immune checkpoint. Sintilimab is a newly approved PD-1 antibody for cancer immunotherapy with an unknown binding epitope on PD-1. In this study, to elucidate the molecular mechanism by which sintilimab blocks PD-1 activation, we applied Antibody binding epitope Mapping (AbMap) to identify the binding epitope of sintilimab. An epitope was successfully identified, i.e. SLAPKA, aa 127-132. By constructing a series of point mutations, the dominant residues S127, L128, A129, P130, and A132 of PD-1 were further validated by western blot analysis, biolayer interferometry, and flow cytometry. Structural analysis showed that the epitope is partially within the binding interface of PD-1 and PD-L1, and this epitope also partially overlaps with that of nivolumab and pembrolizumab. These results demonstrate that sintilimab can attenuate PD-1 activation by directly competing with the interaction between PD-1 and PD-L1 through binding with the key residues of the FG loop on PD-1. This study also demonstrates the high efficiency and accuracy of AbMap for determining the binding epitope of therapeutic antibodies.

Preparation of Uracil by bacteria isolated from Morchella.

Morchella is one of the most famous rare edible and medicinal fungi over the world. Highly nutritious and immature cultivation techniques led to the high price and the markets have remained tight. The pathogenic bacteria were serious in artificial cultivation of Morchella that affected the growth and yield of Morchella. Isolation of pathogenic bacteria and metabolites were investigated in order to improve the artificial cultivation technology. The isolated strain (YDJZ-01-01C) was identified by Gram staining and sequence of 16S rDNA. Structures of metabolites were confirmed based on NMR spectra and literatures. However, the main products were uracil and thymine that considered as important intermediate of anti-tumor 5-fluorouracil. Interestingly, a new synthetic pathway for preparation of uracil by microorganism was found except for chemical synthesis. The new preparation pathway provided mild, green, sustainable and environment friendly method to produce uracil that meets the needs of modern chemistry.

Chemical constituents of fungus F03 belonging to Basidiomycota.

Filamentous fungus F03 belonging to Basidiomycota was obtained and identified as Phlebiopsis crassa based on ITS sequence when Morchella. sp was isolated from the wild fruiting body by spores releasing method. Chemical constituents were separated by gel chromatography, HPLC and recrystallization. Structures of compounds were confirmed by NMR data. Four products orsellinic acid (1), α-nigerose (2), uridine (3), N-(4-hydroxyphenyl)acetamide (4) were identified and all compounds were isolated from the genus Phlebiopsis for the first time.

Resveratrol Effects on a Diabetic Rat Model with Coronary Heart Disease.

BACKGROUND Diabetes is a risk factor for coronary atherosclerosis and coronary heart disease. Resveratrol (RESV) is a natural compound with anti-inflammatory effects. The objective of this study is to evaluate the cardio protective effects of RESV in a diabetic rat model with coronary heart disease. MATERIAL AND METHODS Diabetic rat model with coronary heart disease was constructed by feeding high-fat and high-calorie diet, followed by injection of streptozotocin. The diabetic rats received RESV or DMSO as treatment. Insulin, total cholesterol, and total triglyceride levels in serum were measured using enzyme-linked immunosorbent assay (ELISA) to evaluate the effect of RESV in alleviating diabetic symptoms. Inflammatory factors, including tumor necrotic factor α, interleukin-6, interleukin-8, intracellular adhesion molecule 1, vascular-cell adhesion molecule 1, and monocyte chemoattractant protein-1 were assayed using ELISA. Real-time polymerase chain reaction and western blot analysis were performed to evaluate the impact of RESV treatment on the TLR4/MyD88/NF-κB signaling pathway (toll-like receptor 4/myeloid differentiation factor 88/nuclear factor kappa B signaling pathway). Hematoxylin and eosin staining was used to document pathological changes in cardiovascular muscles. RESULTS RESV preserved pancreatic tissue, which therefore reduced levels of glucose and triglycerides glyceride in serum. Inflammatory factors were also suppressed by RESV. TLR4/MyD88/NF-κB signaling pathway was downregulated after RESV treatment. CONCLUSIONS RESV offers protective effects of cardiovascular tissues in the diabetic rat model with coronary heart disease. Those effects are mediated by downregulating the TLR4/MyD88/NF-κB signaling pathway.

Secondary Metabolites and Antiradical Activity of Liquid Fermentation of Morchella sp. Isolated from Southwest China.

Morels famous for their taste and nutrition are in short supply all over the world although they were considered as one of the most highly prized edible and medicinal mushrooms. Because of the limitation of resource and cultivation technology, fermentation of edible mushroom was gradually applied to nutrient, bioactivity and breeder seed preparation. At present, there are more reports on sugar and amino acid but less on other components. Morchella sp. YDJ-ZY-1 was isolated from the wild fruiting body by the spores releasing method in Zunyi Guizhou province in Southwest China and identified based on phenotype and genotype characteristics. Chemical compositions of YDJ-ZY-1 were investigated from liquid fermentation that will lay the foundation for further development and utilization. Four pyranoids (1-4) and 2-(1-oxo-2-hydroxyethyl) furan (5), linoleic acid (6), Morelin (2-hydroxy-cinnamic acid methyl ester, (7) and 1-O-ß-d-ribofuranose-Morelin (8) were obtained from EtOAc extraction and elucidated by spectral data. Product 4 and 8 were new compounds and 7 was isolated from nature for the first time. Antiradical activity was evaluated by free radical scavenging effect on DPPH (1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl). Compound 5 exhibited strong antiradical activity while compounds 1 and 2 exhibited moderate activity. Thus, incubation of Morchella sp YDJ-ZY-1 separated from the wild fruit body afforded eight compounds. Secondary metabolites with new structures were mined from fermentation of Morchella sp. and antiradical activity was evaluated.

Genetic analysis of three porcine bocaparvoviruses and identification of a natural recombinant breakpoint in NS1.

In this study, we obtained the whole genomes of three porcine bocaparvovirus (PBoV) strains (GD6, GD10, and GD23) by polymerase chain reaction. Sequence analysis showed that all three field strains belonged to PBoV group 3 (G3). The phylogenetic trees based on NS1, NP1, and VP1 differed to the extent that these PBoVs were potentially more closely related to bocaparvoviruses known to infect other animals than to other PBoVs. GD6, GD10, and GD23 all included the conserved sequences YLGPF and HDXXY, with known phospholipase A2 activity. Using recombination-detection software we identified a natural recombinant breakpoint in the NS1 region of PBoV G3. The results of this study will further the epidemiological characterization of PBoVs.

Prevalence of antibodies against Toxoplasma gondii in pets and their owners in Shandong province, Eastern China.

BACKGROUND: Pet ownership in China has been steadily increasing over recent years. However, the risk of pet-associated zoonotic infection with the protozoan parasite Toxoplasma gondii remains poorly defined. METHODS: In a cross-sectional survey, we have determined the seroprevalence of T. gondii infection in pet dogs and cats, and pet owners. Serum samples were collected from 360 pets and 460 corresponding pet owners between March 2016 to June 2017, from Shandong province, eastern China. Sera from the animals were tested for anti-T. gondii antibodies using an indirect haemagglutination assay (IHA) and from the pet owners using an enzyme-linked immunosorbent assay (ELISA). RESULTS: Antibodies against T. gondii were detected in 67 of 360 (18.61%) pets. Seroprevalence of T. gondii in pet cats and dogs was 21.67% and 15.56%, respectively. IgG and IgM antibodies were detected in 79 (17.17%) and 4 (0.87%) of pet owners, respectively; with a total of 83 of 460 (18.04%) pet owners testing seropositive for T. gondii. Our seroprevalence data also suggest that cat owners in general and female pet owners in particular could face a higher risk of acquiring T. gondii infection. CONCLUSIONS: Significant levels of anti-T. gondii antibodies were detected in the pets and their owners in Shandong province, eastern China, indicating a potential zoonotic risk. Prophylactic measures should be implemented to reduce the risk of pet owner's exposure to T. gondii infection.

Transforming Growth Factor ß1 (TGF-ß1) Appears to Promote Coronary Artery Disease by Upregulating Sphingosine Kinase 1 (SPHK1) and Further Upregulating Its Downstream TIMP-1.

BACKGROUND Transforming growth factor (TGF)-ß1 is involved in the pathogenesis of coronary artery disease (CAD), but the mechanism of its action remains unclear. Our study aimed to investigate the role of TGF-ß1 in CAD and to explore the possible mechanisms. MATERIAL AND METHODS A total of 60 CAD patients and 54 healthy people were included in this study. Blood samples were drawn from each participant to prepare serum. ELISA was utilized to measure serum level of TGF-ß1. TGF-ß1 expression vector, TGF-ß1 siRNA, and TIMP-1 siRNA were transfected into human primary coronary artery endothelial cell (HCAEC) line cells, and expression of TGF-ß1 sphingosine kinase 1 (SPHK1) and TIMP metallopeptidase inhibitor 1 (TIMP-1) was detected by Western blot. Cell apoptosis was detected by MTT assay. RESULTS Serum level of TGF-ß1 was specifically higher in patients with CAD than in healthy controls. Serum levels of active TGF-ß1 can be used to effectively distinguish CAD patients from healthy controls. TGF-ß1 overexpression promoted the apoptosis of HCAEC and TGF-ß1 siRNA silencing inhibited the apoptosis of HCAEC. TGF-ß1 overexpression also promoted the expression of SPHK1 and TIMP-1. SPHK1 overexpression upregulated TIMP-1 but it showed no significant effects on TGF-ß1. TIMP-1 overexpression showed no significant effects on TGF-ß1 or SPHK1. SPHK1 inhibitor and TIMP-1 silencing reduced the enhancing effects of TGF-ß1 overexpression on cell apoptosis. CONCLUSIONS TGF-ß1 appears to promote CAD through the induction of cell apoptosis by upregulating SPHK1 expression and further upregulating its downstream TIMP-1.

Toxoplasma gondii and Neospora caninum in Tolai Hares (Lepus tolai) Intended for Human Consumption in China: Seroprevalence, DNA Detection, and Genotyping.

Currently, there is no information available on the detection of Toxoplasma gondii and Neospora caninum in the tissues of Tolai hares in China. This study aimed to investigate the prevalence of these protozoan parasites in Tolai hares obtained from Shandong province, eastern China, between January 2016 and June 2017. Serum and brain tissue samples of 358 Tolai hares were obtained and detected for the presence of antibody and parasite DNAs by serodiagnosis and polymerase chain reaction (PCR), respectively. The seroprevalence of T. gondii and N. caninum infection in Tolai hares was 8.10% (29/358) and 0.84% (3/358), respectively. However, all the 358 tested Tolai hares were negative for N. caninum by PCR and T. gondii DNA was detected in 23 Tolai hares (6.42%, 23/358). The positive T. gondii DNA was genotyped at 11 genetic markers using multilocus PCR-restriction fragment length polymorphism technology. Of the 23 positive samples, only 2 of them produced complete genotyping results, and were identified as ToxoDB Genotype #9. This is the first report to detect T. gondii in the tissues of Tolai hares from China and the first study to focus on N. caninum in Tolai hares from China.

Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections in stray and pet cats (Felis catus) in northwest China: co-infections and risk factors.

This study was conducted to estimate the prevalence of Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections among stray and pet cats in Lanzhou, northwest China, and to identify the influence of age, gender, and regions on seropositivity. T. gondii antibodies were examined in cat sera by the modified agglutination test (MAT). The circulating antigens of D. immitis and FeLV and specific antibodies to FIV were examined using kits commercially available. The overall prevalence of T. gondii, FIV, FeLV, and D. immitis was 19.34, 9.12, 11.33, and 3.04 %, respectively. For the genetic characterization of T. gondii genotypes in cats, genomic DNA was extracted from the seropositive cats and the T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genotyped using multilocus PCR-RFLP. Two T. gondii genotypes (ToxoDB#9 and ToxoDB#1) were identified. Results of the multivariate logistic regression analysis showed that older cats are more likely to be seropositive than juveniles for T. gondii, FIV, FeLV, and D. immitis. This is the first report of T. gondii genotypes in cats in northwest China. Moreover, the present study is the first study of retrovirus and D. immitis seroprevalence in cats in China. The results revealed that T. gondii, FIV, and FeLV infections are common in stray and pet cats in northwest China.

Seroprevalence and risk factors of hepatitis E virus infection among children in China.

Hepatitis E virus (HEV) infection is an important public health concern worldwide, especially in developing countries, causing waterborne outbreaks as well as sporadic autochthonous hepatitis. China is usually considered to be a HEV-endemic area, but the prevalence of HEV infection in children in mainland China remains unclear. Between May 2013 and July 2014, a cross-sectional study was conducted to estimate the seroprevalence and potential risk factors associated with the acquisition of HEV infection by children in China. A total of 1,500 healthy children (range 1-18; 942 and 558 from urban and rural areas, respectively) were recruited to examine for the presence of anti-HEV IgG and IgM antibodies by enzyme-linked immunosorbent assay. Socio-demographic and behavioral characteristics from the examined children were obtained. The overall seroprevalence of HEV in the examined children was 14.93%. Of these, 174 (11.60%) were positive for only anti-HEV IgG antibodies, 50 (3.33%) were IgM positive and IgG negative, and 44 (2.93%) were positive for both anti-HEV IgG and IgM antibodies. Age, type of residence area, contact with pigs, and source of drinking water were found to be associated with HEV infection. These findings demonstrated the high prevalence of HEV and the considerable potential for the transmission of HEV infection in children in China.

Evaluation of MIRU-VNTR for typing of Mycobacterium bovis isolated from Sika deer in Northeast China.

BACKGROUND: Bovine tuberculosis has led to serious economic losses for Sika Deer producers in China. Strategies for controlling the spread of Mycobacterium bovis are often hampered by a lack of epidemiological data. Specifically, tracing infections requires the ability to trace back infections, which, in turn, requires the ability to determine isolates with a common source. This study was planned to assess the discriminatory power of each mycobacterial interspersed repetitive unit (MIRU)-variable number tandem repeats (VNTR) locus and evaluate the most appropriate combination of MIRU-VNTR loci for molecular epidemiological studies on Sika Deer in China. RESULTS: The discriminatory power of MIRU-VNTR typing based on 22 known loci (12 MIRUs, 2 ETRs, 4 QUBs, and 4 Mtubs) were assessed in 96 Mycobacterium bovis strains collected sequentially from Sika Deer at a slaughterhouse in northeastern China. We defined four loci (MIRU4, ETRA, QUB11b, and Mtub4) as highly discriminative, eight loci (MIRU2, MIRU23, MIRU27, MIRU31, MIRU39, MIRU40, QUB26, and Mtub21) as moderately discriminative, and three loci (MIRU16, Mtub30, and Mtub34) as poorly discriminative. The final locus showed no polymorphism between strains. MIRU-VNTR typing as a whole was highly discriminative, with an overall allelic diversity of 0.897. Of the loci tested, the four highly discriminative loci and eight moderately discriminative loci proved to be most appropriate for first line typing of M. bovis from Sika Deer, with the same resolving ability as all 22 loci (H = 0.897). CONCLUSIONS: MIRU-VNTR typing is quick and effective for typing bovine tuberculosis isolates from Sika Deer 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 of Encephalitozoon cuniculi and Toxoplasma gondii in domestic rabbits (Oryctolagus cuniculus) in China.

The breeding of domestic rabbits (Oryctolagus cuniculus) for human consumption has a long tradition in China. Infections that can affect the production of meat or even be transmitted from animals to humans are important to monitor, especially for public health reasons as well as for their impact on animal health. Thus, a total of 1,132 domestic rabbit sera from 4 regions in China were collected for serological screening for Encephalitozoon cuniculi and for Toxoplasma gondii by ELISA and modified agglutination test (MAT), respectively. Antibodies to E. cuniculi were detected in 248/1,132 (21.9%) sera tested while antibodies against T. gondii revealed a seroprevalence of 51/1,132 (4.5%). We believe that the present results are of epidemiological implications and public health importance due to the acknowledged susceptibility of humans to E. cuniculi and T. gondii infections. Therefore, routine screening tests of domestic rabbits are proposed considering the zoonotic potential of these parasites.

Seroprevalence and risk factors of Mycobacterium avium subspecies paratuberculosis infection in domestic sika deer in China.

Paratuberculosis or Johne's disease (JD), caused by Mycobacterium avium subspecies paratuberculosis (MAP), is a chronic infectious granulomatous enteritis of ruminants and other animals, which has a worldwide occurrence, but little is known of MAP infection in domestic sika deer in Jilin Province, China. The objective of the present investigation was to examine seroprevalence and risk factors of MAP infection in Jilin Province. Serum samples collected from 1400 sika deer from 16 sika deer herds were collected in the 4 districts of the province between May 2013 and August 2014 and were tested independently for the presence of antibodies against MAP. A total of 247 (17.64 %) sika deer tested positive for MAP antibodies using a commercially available enzyme immunoassay kit. The management level of farm and collecting region of sika deer was the main risk factor associated with MAP infection. The present study revealed the seroprevalence of MAP infection in sika deer in Jilin Province, China, which provided the baseline data for taking comprehensive countermeasures and measures in effectively preventing and controlling MAP infection in sika deer.