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1.
Probiotics have been defined as live microorganisms that are administered in an appropriate amount to provide health benefits to the host animal. In this study, we investigated the effect of L. salivarius DJ‐sa‐01 secreting the 3D8 single‐chain variable fragment (3D8 scFv) on the growth performance, cytokine secretion, and intestinal microbial flora of chickens. The experiment was divided into the control group and L. salivarius expressing 3D8 scFv experimental group. Chicken was fed 109 colony‐forming units (CFUs) of wild‐type (WT) L. salivarius or 3D8 scFv‐secreting L. salivarius daily for 35 days. The administration of L. salivarius expressing 3D8 scFv significantly improved the body weight of chickens compared with the administration of WT L. salivarius. A 16S ribosomal RNA metagenomic analysis showed that Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the dominant phyla in both experimental groups. At the genus level, Lactobacillus was more abundant (22.82%) in the L. salivarius/3D8 group compared with the WT L. salivarius group. The serum levels of cytokines, such as IL‐8, TNF‐α, IL‐1β, IFN‐γ, IL‐4, and IGF1, were significantly reduced in the L. salivarius/3D8‐treated chickens. In summary, our results suggest that L. salivarius expressing 3D8 scFv could be considered a feed additive for improving the growth performance, immune function, and disease resistance of poultry.  相似文献   

2.
Antimicrobial resistance is a worldwide public health threat; hence, current trends tend to reduce antimicrobial use in food‐producing animals and to monitor resistance in primary production. This study aimed at evaluating the impact of antimicrobial use and production system on swine farms in the antimicrobial resistance of Campylobacter, Salmonella and Staphylococcus, the main zoonotic pathogens in pig herds, in order to assess their potential value as sentinel microorganisms in antimicrobial resistance surveillance schemes. A total of 37 Spanish swine farms, 18 intensive and 19 organic/extensive farms, were included in the study. The antimicrobial resistance of 104 Campylobacter, 84 Staphylococcus and 17 Salmonella isolates was evaluated using Sensititre plates following the EUCAST guidelines. Mixed‐effects logistic regression was used to evaluate the influence of production system and antimicrobial use in resistant and multidrug‐resistant (MDR) phenotypes to the antimicrobials tested. The results showed that antimicrobial use was higher (p < .001) on intensive farms than on organic/extensive farms. MDR in Campylobacter and Staphylococcus was lower on organic/extensive farms (OR < .01p < .001). Antimicrobial resistance in Campylobacter and Staphylococcus isolates was, also for most of the antimicrobials studied, significantly higher in intensive than organic/extensive pig herds. Tetracycline resistance was associated with total antimicrobial consumption in both microbial species (p < .05), and some cross‐associations between distinct antimicrobial substances were established, for instance resistance to erythromycin was associated with macrolide and phenicol consumption. No significant associations could be established for Salmonella isolates. The results demonstrate the link between antimicrobial consumption and resistance in zoonotic bacteria and evidence the potential value of using Campylobacter and Staphylococcus species in monitoring activities aimed at determining the impact of antimicrobials use/reduction on the occurrence and spread of antimicrobial resistance.  相似文献   

3.
The probiotic Lactobacillus brevis KB290 is a natural producer of cell‐bound exopolysaccharide (EPS), and the plasmid‐encoded glycosyltransferase genes are responsible for this EPS production. KB290 forms unique rugose colonies inside an agar medium; this characteristic is useful for detecting and enumerating KB290 in the gut or feces. However, the genetic elements associated with this morphology remain unclear. Here, we aimed to investigate the relation between the plasmid eps genes and rugose colony morphology in KB290. The plasmid‐cured mutants formed smooth colonies, and the rugose colony morphology was restored after complementation with the eps genes. The eps genes were successfully cloned and expressed in other L. brevis and L. plantarum strains. In these transformant strains, the presence of the EPS, consisting of glucose and N‐acetylglucosamine, correlated with rugose colonies, indicating that EPS is responsible for rugose colony formation. To the best of our knowledge, this is the first report identifying the genetic factors influencing rugose colonies in Lactobacillus strains. This rugose colony formation may serve as a useful selective marker for KB290 in routine laboratory and research settings and can be used to detect the spontaneous loss of plasmids in this strain.  相似文献   

4.
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5.
Apelin is a recently discovered peptide produced by several tissues in the various vertebrates and fish. Apelin has been suggested to have role in regulation of many diverse physiological functions including food intake, energy homoeostasis, immunity, osmoregulation and reproduction. In this study, apelin‐13 levels in the blood serum of Cyprinus carpio and Capoetta trutta were determined. Then the results were compared between two species and sexes of each species. Apelin‐13 level was analysed using the enzyme‐linked immunoassay (ELISA) kit (Rat apelin‐13 ELISA kit, catalog no: CSB‐E14367r). Apelin‐13 level in the blood serum of C. trutta was significantly higher than those of the C. carpio (p < 0.05). However, its levels were observed to be no significant difference (p > 0.05) that compared to between sexes of each species. There was a significant negative correlation (r = ?0.829, p = 0.0001) between the apelin‐13 level and body weight of C. carpio. However, no significant correlation (r = ?0.022, p = 0.924) between the apelin‐13 level and weight of C. trutta observed.  相似文献   

6.
Lactobacillus rhamnosus GG (LGG) is increasingly applied in functional food products and acts as a probiotic model in nutritious and clinical studies. Increasing evidences have revealed the immune modulation of LGG on macrophages. The aim of this study is to investigate the effect of LGG on macrophage polarization of murine bone marrow‐derived macrophages (BMDMs). BMDMs were treated with 108 colony‐forming units (CFU)/ml LGG for 1.5, 3, and 6 hr. Results showed that LGG obviously upregulated the mRNA expression of M1‐associated cytokines (p < .05), including interleukin‐1 beta (IL‐1β), IL‐6, tumor necrosis factor‐alpha (TNF‐α), and inducible nitric oxide synthase (iNOS), whereas had no effect on the expression of M2‐associated markers (p > .05), including arginase 1 (Arg1), mannose receptor, and chitinase‐like protein 3 (YM1). Furthermore, LGG markedly increased the expression of pro‐inflammatory cytokines (IL‐12p40, cyclooxygenase‐2 [COX‐2], and interferon‐γ [IFN‐γ]) (p < .05) and anti‐inflammatory cytokines (IL‐10, IL‐4, and transforming growth factor‐β [TGF‐β]) (p < .05). In addition, we also found that TLR2/MyD88/MAPK signaling pathway was required for LGG‐induced M1 macrophage polarization and M1‐related cytokines expression. Together, these findings demonstrate that probiotic LGG facilitates M1 polarization of BMDMs, suggesting that LGG may have an immunotherapeutic potential in regulating the host defense against pathogen invasion.  相似文献   

7.
Campylobacter is the most common cause of bacterial food‐borne diarrhoeal disease throughout the world. The principal risk of human contamination is handling and consumption of contaminated poultry meat. To colonize poultry, Campylobacter adheres to and persists in the mucus layer that covers the intestinal epithelium. Inhibiting adhesion to the mucus could prevent colonization of the intestine. The aim of this study was to investigate in vitro the protective effect of defined commercial human probiotic strains on the adhesion of Campylobacter spp. to chicken intestinal mucus, in a search for alternatives to antibiotics to control this food‐borne pathogen. The probiotic strains Lactobacillus rhamnosus GG and Propionibacterium freudenreichii ssp. shermanii JS and a starter culture strain Lactococcus lactis ssp. lactis adhered well to chicken intestinal mucus and were able to reduce the binding of Campylobacter spp. when the mucus was colonized with the probiotic strain before contacting the pathogen. Human‐intended probiotics could be useful as prophylactics in poultry feeding for controlling Campylobacter spp. colonization.  相似文献   

8.
In this study, we examined the potential of Megasphaera elsdenii as a probiotic agent in combination with sodium gluconate. We also examined the combination of M. elsdenii with probiotic lactic acid bacteria (LAB), Lactobacillus acidophilus, to enhance butyrate production in the large intestine using a pig cecal in vitro model under the presence of sodium gluconate. Compared to the uninoculated control culture (with only diluted cecal digesta), the addition of M. elsdenii and LAB to the culture stimulated significantly the production of n‐butyrate (60% increase) and n‐valerate (50% increase) after 24 h incubation. n‐Butyrate is regarded as the most important short‐chain fatty acid in the large intestine because it stimulates the proliferation of epithelial cells, mucus release and water and mineral absorption. Therefore, lactate‐utilizing butyrate producers such as M. elsdenii play a significant role in supporting the health‐beneficial effects of lactogenic prebiotics and probiotics LAB. The potential of M. elsdenii as a probiotic was also suggested.  相似文献   

9.
This study was conducted to evaluate the influence of back‐fat thickness (BF), at mating of sows, on the maternal and newborn circulating lipids, expression of placental fatty acids (FA) transporters and lipid accumulation in placenta. Full‐term placentas were obtained by vaginal delivery from BFI (9–14 mm; n = 37), BFII (15–19 mm; n = 43) and BFIII (20–27 mm; n = 38) sows according to BF at mating, and frozen placental sections were analysed for fat accumulation. Blood samples were collected from the sows of day 105 pregnancy and from cord blood at delivery. mRNA and protein expression levels were evaluated with real‐time RT‐PCR and Western blotting. Our results demonstrated that BFII females had significantly increased litter weight and placental efficiency, decreased maternal triglyceride (TG) and non‐esterified fatty acids (NEFA) levels, decreased maternal IL‐6, TNFα and leptin levels compared to BFIII females (p < .05). BFIII sows were associated with significantly decreased newborn TG levels, increased newborn glucose, IL‐6 and TNFα levels compared to BFI or BFII sows (p < .05). BFI and BFII females had significantly decreased placental TG, NEFA and cholesterol (CHOL) contents compared to BFIII females (p < .05). Moreover, decreased CD36, FATP1, FABP4, and FABP1 mRNA and protein and FATP4 protein expression, and increased LPL activity were also observed in BFIII group compared with BFII group (p < .05). PPARγ mRNA and protein and lipogenic genes such as SREBP‐1c, ACSL1, ACCα, FAS and SCD mRNA expression were downregulated or upregulated, respectively, in the placentas of BFIII sows compared to BFI or BFII sows (p < .05). Overall, this study demonstrated that there is no advantage, in terms of litter live size, litter weight and placental FA transport and metabolism, in performing the mating of sows with BF>19 mm.  相似文献   

10.
This study investigated the effect of Lactobacillus plantarum strain 299v on gut health in suckling piglets. Sixty newborn piglets were assigned to control and probiotic treatments, with three litters per treatment (ten piglets/litter). From days 1 to 20 of life, piglets were orally administered a placebo of 0.1% peptone or 1.0 ×  1010 CFU L. plantarum 299v daily. Six piglets per treatment were sacrificed on day 20, and intestinal tissues (including duodenum, jejunum, ileum and colon) and the intestinal contents from colon segments were collected. The results demonstrated that piglets treated with L. plantarum 299v had a lower diarrhoea incidence than the controls. L. plantarum 299v administration significantly increased the ratio of the villus height to the crypt depth in the jejunum and ileum, as well as the mRNA expression of jejunal occludin and ileal zonula occludens 1 (ZO‐1). The L. plantarum treatment also increased the mRNA abundance of porcine β‐defensin 2 (pBD2) and pBD3 in the jejunum and ileum and of toll‐like receptors (TLRs), such as TLR2, TLR4, TLR6 and TLR9 in the ileum, and significantly upregulated the mRNA abundances of ileal pBD1 and colonic TLR4. Additionally, the L. plantarum 299v treatment significantly changed the structure of the colonic microbiota, as evidenced by the obvious increases in the relative abundances of the phyla Firmicutes and Actinobacteria and of the genus Lactobacillus. Our findings indicate that L. plantarum 299v facilitates the gut health of suckling piglets, probably by improving the intestinal morphology and intestinal barrier function and by modifying the structure of the gut microbiota.  相似文献   

11.
Lactic acid bacteria play an essential role in the food industry in the manufacture of many fermented products (cheese, yogurt, fermented vegetables, etc.). Application of these organisms is now being extended to the area of health improvement, as their probiotic activities become known. Probiotics are defined as viable microorganisms that exert a beneficial effect on the health of the host when they are ingested in sufficient quantity. Lactic acid bacteria and bifidobacteria isolated from the human intestine are the most common probiotics used for human consumption. The development of new probiotics with new beneficial effects is eagerly awaited in the food industry. This review introduces Lactococcus, which are one of the genera of lactic acid bacteria and are mainly isolated from dairy products and fermented vegetables, as new probiotics, focusing especially on Lactococcus lactis H61, which improves skin status in Japanese women with oral intake of heat‐killed or live cells. The deduced mechanisms associated with the beneficial effects of strain H61 are also discussed.  相似文献   

12.
Asthma is a chronic inflammatory lung disease of the airway; the incidence and prevalence of asthma remain high worldwide. Astragaloside IV (AS‐IV) is the main active constituent of Astragalus membranaceus. Accumulating evidence suggests that AS‐IV possesses anti‐inflammatory and anti‐asthmatic ability, but the potential molecular mechanism is required to further clarify. In this study, the anti‐asthmatic effects of AS‐IV on mice with ovalbumin (OVA)‐induced allergic inflammation were analysed. We analysed airway hyperresponsiveness (AHR), numbers of inflammatory cells, inflammation situation in lung tissue and cytokines level in bronchoalveolar lavage fluid (BALF) between OVA‐induced mice with and without AS‐IV treatment. Moreover, we explored the possible signalling pathway behind the anti‐asthmatic effects. Our results revealed that AS‐IV treatment ameliorates airway inflammation and AHR in an OVA‐induced asthma model. Besides, AS‐IV treatment inhibits the interleukin (IL)‐4, ‐5 and ‐13 production, and further study indicated that AS‐IV treatment downregulates the expression level of p‐JAK2/p‐STAT6 proteins. Taken together, the present study suggested that the inhibitory effects of AS‐IV on asthma therapy are at least partially involved in inhibiting the JAK2/STAT6 signalling pathway.  相似文献   

13.
Hepatitis E virus is a major causative agent of acute hepatitis worldwide. Despite its zoonotic potential, there is limited information about the natural chain of hepevirus infection in wildlife, and the potential reservoir species. In this study, we performed a HEV survey by heminested RT‐PCR on rodent samples from an urban environment (in the city of Pécs, Hungary) and investigated the prevalence of the virus among these native rodent species (Apodemus agrarius, Apodemus flavicollis, Apodemus sylvaticus, Microtus arvalis and Myodes glareolus). HEV was detected exclusively in Common voles (M. arvalis), in 10.2% of screened voles, and 3.2% of all investigated samples from all species. Based on the phylogenetic analysis, our strain showed the closest homology with European Orthohepevirus C strains detected previously in faecal samples of birds of prey and Red fox, supporting the possibility of the dietary origin of these strains. In addition, our samples showed close phylogenetic relation with a South American strain detected in Necromys lasiurus (Cricetidae), but separated clearly from other Muridae‐associated strains, suggesting the presence of a Cricetidae‐specific genotype in Europe and South‐America. Based on these results, we hypothesize the reservoir role of M. arvalis rodents for the European Cricetidae‐specific Orthohepevirus C genotype.  相似文献   

14.
Bacillus species are commonly used as probiotics in the poultry feed industry for preventing infectious diseases and improving productivity by altering gastrointestinal microbiota. The growth parameters of Bacillus subtilis for surfactin production in fermentation and the benefits of surfactin on broiler chickens remain unclear. In this study, we examined the growth parameters of B. subtilis in fermentation and evaluated the effects of surfactin from B. subtilis‐fermented products on Clostridium perfringens‐induced necrotic enteritis and growth performance in broilers. Results showed that the highest viable biomass of B. subtilis was observed at 10% molasses and 2% yeast supplementation during fermentation. The 4‐ and 6‐day fermented B. subtilis products were heat‐, acid‐ and bile‐resistant. Furthermore, the 4‐day fermented B. subtilis products with the highest surfactin concentration showed the maximal antimicrobial activity against pathogens, including Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and C. perfringens. Dietary B. subtilis‐fermented product supplementation in broilers significantly improved intestinal morphology and necrotic lesions under C. perfringens challenge. Bacillus subtilis treatments could enhance broiler productivity, as well as promote bone quality and intestinal morphology. These results together indicate that B. subtilis‐fermented products containing surfactin have potential for the development as feed additives and use as possible substitutes for antibiotics to treat C. perfringens in the poultry industry.  相似文献   

15.
Lactic acid bacteria were screened for potential probiotics for use as feed additives. We obtained 3,000 isolates from feces of: cattle, dogs, goats, and infants; milk; yogurt; cheese; fermented sausages; Kimchi; and Cheonggukjang and tested their antibacterial activity toward indicator pathogens, including Bacillus cereus, Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica Enteritidis. We further tested their tolerance to artificial gastric juice (1% [w/v] pepsin, pH 2.5) and bile acid (0.1% [w/v] oxgall, pH 6.8). Six isolates exhibited strong antibacterial activity against indicator pathogens. The PA40 isolate from Kimchi exhibited marked resistance to artificial gastric juice and bile acid. The antibacterial substances produced by PA40 were stable to heat, pH, and enzymes. Strain PA40 was identified as a Lactobacillus curvatus strain using chemical tests and 16S rDNA sequencing and produced 248.4 mmol/L lactic acid after 48 hr of fermentative growth. The L. curvatus PA40 strain was also highly tolerant of the artificial gastrointestinal model system. Our results indicate that L. curvatus PA40 could be used as a potential probiotic feed additive.  相似文献   

16.
Tick‐borne relapsing fever (TBRF) is a potentially serious spirochetal infection caused by certain species of Borrelia and acquired through the bite of Ornithodoros ticks. In 2017, Austin Public Health, Austin, TX, identified five cases of febrile illness among employees who worked in caves. A cross‐sectional serosurvey and interview were conducted for 44 employees at eight organizations that conduct cave‐related work. Antibodies against TBRF‐causing Borrelia were detected in the serum of five participants, four of whom reported recent illness. Seropositive employees entered significantly more caves (Median 25 [SD: 15] versus Median 4 [SD: 16], p = 0.04) than seronegative employees. Six caves were entered more frequently by seropositive employees posing a potentially high risk. Several of these caves were in public use areas and were opened for tours. Education of area healthcare providers about TBRF and prevention recommendations for cavers and the public are advised.  相似文献   

17.
To study the effect of supplementation of tannin degrading bacterial culture (Streptococcus gallolyticus strain TDGB 406) on growth performance, nutrient utilization and urinary purine derivatives of goats fed on oak (Quercus semicarpifolia) leaves. For growth study, eighteen billy goats (4 month old, average body weight 9.50 ± 1.50 kg) were distributed into three groups of six animals each. The animals of group 1 served as control while animals of groups 2 (T1) and 3 (T2) were given (@ 5 ml/kg live weight) autoclaved and live culture of isolate TDGB 406 (106 cells/ml) respectively. The animals were fed measured quantity of dry oak leaves as the main roughage source and ad libitum maize hay along with fixed quantity of concentrate mixture. The feeding of live culture of isolate TDGB 406 (probiotic) did not affect dry matter intake and digestibility of nutrients except that of dry matter and crude protein, which was higher in T2 group as compared to control. All the animals were in positive nitrogen balance. There was no significant effect of feeding isolate TDGB 406 on urinary purine derivatives (microbial protein production) in goats. The body weight gain and average live weight gain was significantly higher (p = 0.071) in T2 group as compared to control. Feed conversion efficiency was also better in the goats fed on live culture of TDGB 406 (T2). The feeding of tannin degrading bacterial isolate TDGB 406 as probiotic resulted in improved growth performance and feed conversion ratio in goats fed on oak leaves as one of the main roughage source.  相似文献   

18.

Background

Progress in establishing if therapies provide relief to cats with degenerative joint disease (DJD)‐associated pain is hampered by a lack of validated owner‐administered assessment methods.

Hypothesis

That an appropriately developed subjective owner‐completed instrument (Feline Musculoskeletal Pain Index‐FMPI) to assess DJD‐associated impairment would have responsiveness and criterion validity.

Animals

Twenty‐five client‐owned cats with DJD‐associated pain.

Methods

FMPI responsiveness (ability to detect the effect of an analgesic treatment) and validity (correlation with an objective measure) were explored through a stratified, randomized, double blinded, placebo‐controlled, crossover 10‐week clinical study. Meloxicam was administered to effect pain relief. A linear mixed model, backward stepwise regression, and Pearson correlations were used to assess responsiveness and criterion validity with the assumption that the NSAID would increase activity.

Results

Positive responses of cats to placebo (P = .0001) and meloxicam treatment (P = .0004) were detected; however, the instrument did not detect any difference between placebo and meloxicam (linear mixed model), even for the high impairment cases. Percent meloxicam target dose administered, temperament, and total baseline FMPI score were covariates that most affected FMPI scores. Controlling for significant covariates, most positive effects were seen for placebo treatment. Positive treatment effects on activity were detected, but only for the cases designated as most highly impaired.

Conclusions and Clinical Importance

Neither responsiveness nor criterion validity were detected by the inclusion criteria for cases in this study. The data suggest that further work is indicated to understand factors affecting activity in cats to optimize inclusion criteria.  相似文献   

19.
Increase in the number of small‐scale backyard poultry flocks in the USA has substantially increased human‐to‐live poultry contact, leading to increased public health risks of the transmission of multi‐drug resistant (MDR) zoonotic and food‐borne bacteria. The objective of this study was to detect the occurrence of Salmonella and MDR Gram‐negative bacteria (GNB) in the backyard poultry flock environment. A total of 34 backyard poultry flocks in Washington State (WA) were sampled. From each flock, one composite coop sample and three drag swabs from nest floor, waterer‐feeder, and a random site with visible faecal smearing, respectively, were collected. The samples were processed for isolation of Salmonella and other fermenting and non‐fermenting GNB under ceftiofur selection. Each isolate was identified to species level using MALDI‐TOFF and tested for resistance against 16 antibiotics belonging to eight antibiotic classes. Salmonella serovar 1,4,[5],12:i:‐ was isolated from one (3%) out of 34 flocks. Additionally, a total of 133 ceftiofur resistant (CefR) GNB including Escherichia coli (53), Acinetobacter spp. (45), Pseudomonas spp. (22), Achromobacter spp. (8), Bordetella trematum (1), Hafnia alvei (1), Ochrobactrum intermedium (1), Raoultella ornithinolytica (1), and Stenotrophomonas maltophilia (1) were isolated. Of these, 110 (82%) isolates displayed MDR. Each flock was found positive for the presence of one or more CefR GNB. Several MDR E. coli (n = 15) were identified as extended‐spectrum β‐lactamase (ESBL) positive. Carbapenem resistance was detected in non‐fermenting GNB including Acinetobacter spp. (n = 20), Pseudomonas spp. (n = 11) and Stenotrophomonas maltophila (n = 1). ESBL positive E. coli and carbapenem resistant non‐fermenting GNB are widespread in the backyard poultry flock environment in WA State. These GNB are known to cause opportunistic infections, especially in immunocompromised hosts. Better understanding of the ecology and epidemiology of these GNB in the backyard poultry flock settings is needed to identify potential risks of transmission to people in proximity.  相似文献   

20.
Hepatitis E virus (HEV) strains belonging to the Orthohepevirus genus are divided into four species (A–D). HEV strains included in the Orthohepevirus A species infect humans and several other mammals. Among them, the HEV‐3 and HEV‐4 genotypes are zoonotic and infect both humans and animals, of which, pigs and wild boar are the main reservoirs. Viruses belonging to the Orthohepevirus C species (HEV‐C) have been considered to infect rats of different species and carnivores. Recently, two studies reported the detection of HEV‐C1 (rat HEV) RNA in immunocompromised and immunocompetent patients, suggesting a possible transmission of rat HEV to humans. The role of rats and mice as reservoir of HEV and the potential zoonotic transmission is still poorly known and deserves further investigation. To this purpose, in this study, the presence of HEV RNA was investigated in the intestinal contents and liver samples from 47 Black rats (Rattus rattus) and 21 House mice (Mus musculus) captured in four pig farms in Northern Italy. The presence of both Orthohepevirus A and C was investigated by the real‐rime RT‐PCR specific for HEV‐1 to HEV‐4 genotypes of Orthohepevirus A species and by a broad spectrum hemi‐nested RT‐PCR capable of detecting different HEV species including rat HEV. The intestinal content from two Black rats resulted positive for HEV‐C1 RNA and for HEV‐3 RNA, respectively. None of the House mice was HEV RNA positive. Sequence analyses confirmed the detection of HEV‐C1, genotype G1 and HEV‐3 subtype e. The viral strain HEV‐3e detected in the rat was identical to swine HEV strains detected in the same farm. Liver samples were negative for the detection of either rat HEV or HEV‐3.  相似文献   

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