家养动物体表蜱中发热伴血小板减少综合征布尼亚病毒分离及鉴定

为了解发热伴血小板减少综合征布尼亚病毒(SFTSV)的传播机制,采集了山东疫区家养牛、羊和狗等动物体表蜱,分类鉴定后,通过Real-time PCR筛查、病毒分离培养和基因组序列分析等方法分离鉴定蜱中的病毒。所采集的蜱,以长角血蜱为主,占91.4%。其中3头SFTSV核酸检测阳性,阳性率为2.14%,并在其中一份羊体表蜱标本中分离到SFTSV病毒,命名为SDLZTick12。序列分析显示与我国在不同省份患者标本中分离的病毒全基因序列具有高度同源性,且病毒的抗原性和生长特性与人源病毒相同。本研究首次在山东疫区蜱中分离到新型布尼亚病毒,并与人源病毒进行了系统比较研究,提示蜱可能为该新病原体的传播媒介,对疾病的防控具有重要的指导意义。     

An emerging hemorrhagic fever in China caused by a novel bunyavirus SFTSV

Severe fever with thrombocytopenia syndrome(SFTS) is an emerging hemorrhagic fever in rural areas of China and is caused by a new bunyavirus,SFTSV,named after the disease.The transmission vectors and animal hosts of SFTSV are unclear.Ticks are the most likely transmission vectors and domestic animals,including goats,dogs,and cattle,are potential amplifying hosts of SFTSV.The clinical symptoms of SFTS are nonspecific,but major symptoms include fever,gastrointestinal symptoms,myalgia,dizziness,joint pain,chills,and regional lymphadenopathy.The most common abnormalities in laboratory test results are thrombocytopenia(95%),leukocytopenia(86%),and elevated levels of serum alanine aminotransferase,aspartate aminotransferase,creatine kinase,and lactate dehydrogenase.The fatality rate for SFTS is 12% on average,and the annual incidence of the disease is approximately five per 100000 of the rural population.     

The Potential Role of Synanthropic Rodents and Flies in the Transmission of Enterocytozoon bieneusi on a Dairy Cattle farm in China

Enterocytozoon bieneusi causes microsporidiosis, a condition with complex epidemiology involving both direct and indirect transmission routes. To assess the potential role of synanthropic rodents and flies in the transmission of this pathogen, a total of 277 cattle fecal samples, 199 synanthropic rodents, and 50 batches of 20 flies were collected from a cattle farm. These samples were screened for the presence of E. bieneusi by PCR and sequencing of the internal transcribed spacer (ITS) region of the rRNA gene. The positive rates of cattle, synanthropic rodents, and flies were 11.9% (33/277), 4.0% (8/199) and 12.0% (6/50), respectively. Nineteen genotypes were identified, including 11 known genotypes (BEB6, I, COS‐I, EbpC, D, J, CHS5, CHG1 to CHG3 and CHG14) and eight novel genotypes (named CHC9 to CHC16). The dominant genotype detected in the present study, BEB6, was found in all three categories of hosts. Moreover, human pathogenic genotypes D and EbpC were also observed in both synanthropic rodents and flies. These results demonstrate that synanthropic rodents and flies may act as biological disseminator or mechanical vector in the transmission of microsporidiosis to humans. Efforts should be made to minimize threats from these commensal animals to public health.     

Survey of Pestivirus infection in wild and domestic ungulates from south-western Italian Alps

The transmission of pestiviruses between domestic and wild ruminants has not been documented in communal alpine pastures shared between wildlife and livestock. The aim of this study was to investigate the role of domestic and wild ungulates species from Varaita Valley (SW Italian Alps) in the epidemiology of Pestivirus infections. Sera from free-ranging alpine chamois (Rupicapra rupicapra) and roe deer (Capreolus capreolus) were collected from 1994 to 2009 and 2001 to 2009, respectively. Also, sera from cattle and sheep sampled in 2009 were studied. Sera were tested for the presence of antibodies against pestivirus with an ELISA assay. Sera from positive animals were subsequently tested with a comparative virus neutralisation test using the BVDV-NADL and BDV-137/4 strains. Sera were tested for the presence of pestiviral antigen and the presence of viral RNA with a commercial ELISA assay and RT-PCR. Antibodies against Pestivirus were detected in 132 out of 312 (42%) chamois, in 30 out of 175 (17%) cattle and 6 out of 24 (25%) sheep. No antibodies were found in roe deer. No Pestivirus antigen or RNA was detected in any of the samples. Results indicate circulation of pestiviruses among the studied chamois, cattle and sheep populations. However the role of wild ungulates in the dynamics of Pestivirus infection is still unknown and monitoring the presence of these viruses in wild ungulates would be of importance, especially in the chamois population, where pestiviruses seem to circulate extensively.     

Heat Stability of Serum Lactate Dehydrogenase and its Isoenzymes in Young and Adult Cattle and Sheep

The heat stability of lactate dehydrogenase (LDH) has been investigated in serum from young and adult cattle and sheep. The thermoresistance of the isoenzymes was determined by electrophoresis of serum samples preincubated at different temperatures. Marked differences were found in the percentage distribution of isoenzymes in serum from the two species as well as in the heat stability. LDH in serum from sheep was inactivated at a lower temperature than that in serum from cattle, and inactivation occurred at a lower temperature in young than in adult animals. The enzyme was in both species less tolerant to elevated temperatures than what is reported for human serum. Procedures worked out for a so-called relative heat stability test of LDH in human clinical diagnosis may therefore give misleading results if they were applied uncritically to sera from these animals. The LDH isoenzyme pattern of some main organs in calves and sheep indicates that a serum heat stability test may be useful in the diagnosis of skeletal muscle injuries in sheep. In cattle the tissue isoenzyme distribution is assumed to be too uniform to give information about specific organ lesions either by serum electrophoresis or by a heating technique. In contrast to what has been reported in man, serum levels of α-hydroxybutyrate dehydrogenase (HBD) in cattle and sheep, as earlier reported in swine, are found to be far better correlated to total LDH than to the most thermostable isoenzyme, LDH1.     

The occurrence of antibody to bluetongue virus in New South Wales. I. Statewide surveys of cattle and sheep

Two State-wide surveys were carried out in 1978 to detect bluetongue (BLU) virus antibody in cattle and sheep sera in New South Wales (NSW). The first survey showed that BLU group antibody in cattle 18-24 months old was confined to the coastal regions (east of the Great Dividing Range) and the Hunter Valley. However, in the second survey, of cattle more than 5 years old, reactors were much more widely distributed over the north-eastern third of the State and into the western division with prevalences up to 85% in some areas. In contrast, very few reactors were detected in sheep in either survey (less than 1% of the sheep sera tested). In a retrospective study of stored cattle sera, BLU group reactors were detected in the north-east of the State in each year examined since 1968, the earliest year in which samples were available from that region. Areas to the south and west were free of antibody from 1966 until the summer of 1973, but subsequently reactors were common. Examination of selected area for type-specific antibody indicated that infection of cattle with two of the three Australian BLU serotypes which were known at the time, BLU-1 and BLU-21, had occurred in NSW. No antibody to BLU-20, the original Australian isolate, was detected. A close association was observed between strong group antibody reactions and type-specific neutralizing activity against BLU-1 and BLU-21. Both were largely confined to that area of the State in which a high (75% or more) prevalence of group antibody was recognised in the older animals.(ABSTRACT TRUNCATED AT 250 WORDS)     

Verocytotoxin-Producing Escherichia coli in Wild Birds and Rodents in Close Proximity to Farms

Wild animals living close to cattle and pig farms (four each) were examined for verocytotoxin-producing Escherichia coli (VTEC; also known as Shiga toxin-producing E. coli). The prevalence of VTEC among the 260 samples from wild animals was generally low. However, VTEC isolates from a starling (Sturnus vulgaris) and a Norway rat (Rattus norvegicus) were identical to cattle isolates from the corresponding farms with respect to serotype, virulence profile, and pulsed-field gel electrophoresis type. This study shows that wild birds and rodents may become infected from farm animals or vice versa, suggesting a possible role in VTEC transmission.     

Experimental and Natural Infections of Goats with Severe Fever with Thrombocytopenia Syndrome Virus: Evidence for Ticks as Viral Vector

Background

Severe fever with thrombocytopenia syndrome virus (SFTSV), the causative agent for the fatal life-threatening infectious disease, severe fever with thrombocytopenia syndrome (SFTS), was first identified in the central and eastern regions of China. Although the viral RNA was detected in free-living and parasitic ticks, the vector for SFTSV remains unsettled.

Methodology/Principal Findings

Firstly, an experimental infection study in goats was conducted in a bio-safety level-2 (BSL-2) facility to investigate virus transmission between animals. The results showed that infected animals did not shed virus to the outside through respiratory or digestive tract route, and the control animals did not get infected. Then, a natural infection study was carried out in the SFTSV endemic region. A cohort of naïve goats was used as sentinel animals in the study site. A variety of daily samples including goat sera, ticks and mosquitoes were collected for viral RNA and antibody (from serum only) detection, and virus isolation. We detected viral RNA from free-living and parasitic ticks rather than mosquitoes, and from goats after ticks’ infestation. We also observed sero-conversion in all members of the animal cohort subsequently. The S segment sequences of the two recovered viral isolates from one infected goat and its parasitic ticks showed a 100% homology at the nucleic acid level.

Conclusions/Significance

In our natural infection study, close contact between goats does not appear to transmit SFTSV, however, the naïve animals were infected after ticks’ infestation and two viral isolates derived from an infected goat and its parasitic ticks shared 100% of sequence identity. These data demonstrate that the etiologic agent for goat cohort’s natural infection comes from environmental factors. Of these, ticks, especially the predominant species Haemaphysalis longicornis, probably act as vector for this pathogen. The findings in this study may help local health authorities formulate and focus preventive measures to contain this infection.     

Characterization of Severe Fever with Thrombocytopenia Syndrome in Rural Regions of Zhejiang,China

Severe fever with thrombocytopenia syndrome virus (SFTSV) infections have recently been found in rural regions of Zhejiang. A severe fever with thrombocytopenia syndrome (SFTS) surveillance and sero-epidemiological investigation was conducted in the districts with outbreaks. During the study period of 2011–2014, a total of 51 SFTSV infection cases were identified and the case fatality rate was 12% (6/51). Ninety two percent of the patients (47/51) were over 50 years of age, and 63% (32/51) of laboratory confirmed cases occurred from May to July. Nine percent (11/120) of the serum samples from local healthy people without symptoms were found to be positive for antibodies to the SFTS virus. SFTSV strains were isolated by culture using Vero, and the whole genomic sequences of two SFTSV strains (01 and Zhao) were sequenced and submitted to the GenBank. Homology analysis showed that the similarity of the target nucleocapsid gene from the SFTSV strains from different geographic areas was 94.2–100%. From the constructed phylogenetic tree, it was found that all the SFTSV strains diverged into two main clusters. Only the SFTSV strains from the Zhejiang (Daishan) region of China and the Yamaguchi, Miyazakj regions of Japan, were clustered into lineage II, consistent with both of these regions being isolated areas with similar geographic features. Two out of eight predicted linear B cell epitopes from the nucleocapsid protein showed mutations between the SFTSV strains of different clusters, but did not contribute to the binding ability of the specific SFTSV antibodies. This study confirmed that SFTSV has been circulating naturally and can cause a seasonal prevalence in Daishan, China. The results also suggest that the molecular characteristics of SFTSV are associated with the geographic region and all SFTSV strains can be divided into two genotypes.     

An ultrasensitive capture ELISA for detection of Fasciola hepatica coproantigens in sheep and cattle using a new monoclonal antibody (MM3)

A capture enzyme-linked immunosorbent assay (ELISA) using a new monoclonal antibody (mAb MM3) is reported for the detection of Fasciola hepatica excretory-secretory antigens (ESAs) in feces of infected hosts. The mAb MM3 was produced by immunization of mice with a 7- to 40-kDa purified and O-deglycosylated fraction of F. hepatica ESAs, which has previously been shown to be specific for the parasite. The specificity and sensitivity of the MM3 capture ELISA were assessed using feces from sheep and cattle. Sheep feces were obtained from a fluke-free herd (with most animals harboring other nematodes and cestodes), from lambs experimentally infected with 5-40 F. hepatica metacercariae and in some cases treated with triclabendazole at 14 wk postinfection (PI), and from uninfected control lambs. Cattle feces were collected at the slaughterhouse from adult cows naturally infected with known numbers of flukes (from 1 to 154) or free of F. hepatica infection (though in most cases harboring other helminths). The MM3 capture ELISA assay had detection limits of 0.3 (sheep) and 0.6 (cattle) ng of F. hepatica ESA per milliliter of fecal supernatant. The assay detected 100% of sheep with 1 fluke, 100% of cattle with 2 flukes, and 2 of 7 cattle with 1 fluke. The false-negative animals (5/7) were probably not detected because the F. hepatica individuals in these animals were immature (5-11 mm in length). As expected, coproantigen concentration correlated positively (r = 0.889; P < 0.001) with parasite burden and negatively (r = 0.712; P < 0.01) with the time after infection at which coproantigen was first detected. Nevertheless, even in animals with low fluke burdens (1-36 parasites), the first detection of F. hepatica-specific coproantigens by the MM3 capture ELISA preceded the first detection in egg count by 1-5 wk. In all sheep that were experimentally infected and then untreated, coproantigen remained detectable until at least 18 wk PI, whereas in sheep that were experimentally infected and then flukicide treated, coproantigen became undetectable from 1 to 3 wk after treatment. None of the fecal samples from sheep or cattle negative for fascioliasis but naturally infected with other parasites including Dicroelium dendriticum showed reactivity in the MM3 capture ELISA. These results indicate that this assay is a reliable and ultrasensitive method for detecting subnanogram amounts of F. hepatica antigens in feces from sheep and cattle, facilitating early diagnosis.     

Some epidemiological and epizootiological aspects of Lyme borreliosis in Slovakia with the emphasis on the problems of serological diagnostics

The paper analyses the results of serological examinations of domestic, farm and free-living animals from different regions of Slovakia, Southern Moravia, Southern Bohemia and Southern Poland using ELISA, indirect hemagglutination assay (IHA) and Western blot (WB). In Slovakia, significantly higher seroprevalence was recorded in dogs (33.5%) than in horses (26.5%), cattle (22.5%), sheep (16.6%) and rodents (17.8%) by using a mixture of Borrelia garinii, B. afzelii, B. burgdorferi sensu stricto (s.s.) antigens in ELISA. Seroprevalence in horses was significantly higher than in sheep and rodents, and seroprevalence in cattle was significantly higher than in rodents. By using IHA in free-living species, the highest seropositivity rates were detected in fallow deer (40.7%) compared with moufflons (16.6%), pheasants (8.0%) and pigeons (1.2%). When testing sera of horses, dogs and cattle from Slovakia by using different Slovak B. burgdorferi sensu lato (s.l.) isolates as antigens in ELISA, significantly higher seroprevalence of anti-Borrelia IgG antibodies and consistency of positive and negative findings was detected in comparison when American isolates were used. In WB analyses using the Eurocarpathian antigens, dog sera from Eastern Slovakia and Southern Moravia showed statistically insignificant differences in sensitivity and consistency of positive and negative findings. By using different methods and antigens in the same group of dog sera, significant differences in seroprevalence were only found in IHA with a mixture of Euroamerican B.b.s.l and WB CB26 B.b.s.s. In addition to other factors, the complexity of the standardization of the assay system with regard to the genetic and geographical heterogeneity of B. burgdorferi s.l. isolates used as antigens is also discussed.     

Verocytotoxin-producing Escherichia coli in wild birds and rodents in close proximity to farms

Wild animals living close to cattle and pig farms (four each) were examined for verocytotoxin-producing Escherichia coli (VTEC; also known as Shiga toxin-producing E. coli). The prevalence of VTEC among the 260 samples from wild animals was generally low. However, VTEC isolates from a starling (Sturnus vulgaris) and a Norway rat (Rattus norvegicus) were identical to cattle isolates from the corresponding farms with respect to serotype, virulence profile, and pulsed-field gel electrophoresis type. This study shows that wild birds and rodents may become infected from farm animals or vice versa, suggesting a possible role in VTEC transmission.     

Detection of Leptospira spp. in semen and vaginal fluids of goats and sheep by polymerase chain reaction

Thirteen goat herds and seven sheep flocks in the state of Rio de Janeiro, Brazil were screened for leptospirosis. From the three herds and three flocks with greatest seroreactivity, 19 goats (16 females and three bucks) and 40 sheep (26 ewes and 14 rams) that were seropositive (specific anti-Leptospira titres > or =400, based on a microscopic agglutination test), were selected for more detailed studies. From those animals, samples of vaginal fluids or semen were collected for bacteriological and molecular assays. For both species of animals, the most prevalent reactions were to serovars Hardjo, Shermani, and Grippotyphosa. Although leptospires were detected by darkfield microscopy in three vaginal fluid samples (from two goats and one ewe), pure isolates were not obtained by bacteriological culture of vaginal fluids or semen. However, seven vaginal fluid samples (from four goats and three ewes) and six semen samples (all from rams) were positive on polymerase chain reaction (PCR). Based on these findings, in addition to analogous findings in cattle, we inferred that there is potential for venereal transmission of leptospirosis in small ruminants.     

Development of an enzyme-linked immunosorbent assay for detection of IgM antibodies to Babesia bigemina in cattle

A crude antigenic preparation of Babesia bigemina was used to develop an ELISA for the detection of IgM antibodies. Optimal dilutions of the antigen, using positive and negative reference sera, were determined by checkerboard titrations. Negative sera from cattle imported from tick-free areas, serum samples collected from infected B. bigemina cattle were used to validate the test. The specificity was 94% and sensitivity of the Elisa 87.5%. Sera from 385 cattle deriving from areas free from tick-borne diseases, which were submitted to a preimmunization process, were screened by this technique. The Elisa detected seroconversion on the 14th day post-inoculation in animals either infested with Boophilus microplus ticks (infected with B. bigemina), or inoculated with B. bigemina infected blood. Antibody titers decreased after day 33; however, all animals remained positive until the end of the experiment (124 days). The ELISA described may prove to be an appropriate serological test for the detection of IgM antibodies against B. bigemina.     

Prevalence of Gastrointestinal Clostridium difficile Carriage in Australian Sheep and Lambs

Recently, Clostridium difficile has been isolated from a wide variety of animals, particularly production animals, mainly cattle and pigs. Concurrently, the incidence of C. difficile infection (CDI) in humans has increased in the community, with some suggestions that food-borne transmission of C. difficile is occurring. Interestingly, sheep and lambs appear not to have been investigated for carriage/colonization with C. difficile. The aim of this project was to determine the prevalence of carriage of C. difficile in sheep and lambs in Australia by culturing fecal samples. A total of 371 sheep and lamb fecal samples were received in seven batches from three different geographic areas in eastern Australia and two in Western Australia. The overall rate of detection in sheep and lambs was low (4.0%); however, carriage/colonization in lambs (6.5%) was statistically significantly higher than that in sheep (0.6%) (P = 0.005). Seven distinct PCR ribotype patterns were observed, three of which were known international ribotypes (UK 056 [n = 1], UK 101 [n = 6], and UK 137 [n = 2]), while the remainder were unable to be matched with our available reference library. This low rate of carriage/colonization in Australian ovines suggests they are unlikely to be a major source/reservoir of human infections.     

Prevalence and strain diversity of thermophilic campylobacters in cattle, sheep and swine farms

AIMS: To determine prevalence and strain diversity of thermophilic campylobacters in healthy ruminants and swine. METHODS AND RESULTS: Faecal samples collected from 343 herds (120 sheep, 124 beef cattle, 82 dairy cattle and 17 swine) in the Basque Country were screened in pools for thermophilic campylobacters. Two hundred and three herds were positive (67.1% dairy cattle, 58.9% beef cattle, 55.0% sheep and 52.9% pig), and species-specific PCR identified Campylobacter jejuni in 20.7% of the herds and Campylobacter coli in 6.4%. Campylobacter coli was isolated from the four production systems and was the most prevalent species in swine, where C. jejuni was not found. Other thermophilic campylobacters were found in all production systems. Four hundred and ninety-three animals from 11 positive herds were individually analysed, detecting significantly higher within-herd prevalences in dairy cattle (66.7%) and swine (57.8%) than in sheep (8.8%) or beef cattle (5.4%). flaA PCR-RFLP and pulsed-field gel electrophoresis analysis of a selection of isolates showed high genetic diversity. CONCLUSIONS: Healthy swine, cattle and sheep are important reservoirs of thermophilic campylobacters of different species and high genetic diversity. SIGNIFICANCE AND IMPACT OF THE STUDY: Efficient farm-based intervention measures are needed to reduce risk of infection. Non-C. jejuni/C. coli species should be monitored to investigate their significance for infection.     

Animal host associated differences in Shiga toxin-producing Escherichia coli isolated from sheep and cattle on the same farm

AIMS: To investigate if cattle on the same farm as sheep are a possible risk factor for stx in sheep and to determine whether or not sheep and cattle on the same farm share the same stx pool. METHODS AND RESULTS: Faecal samples from sheep and cattle were screened for stx by polymerase chain reaction (PCR). Of these samples, 87.6 and 64.6% were stx positive in sheep and cattle, respectively. There was no difference in stx occurrence in sheep from farms with or without cattle. From stx positive samples, 118 Shiga toxin-producing Escherichia coli (STEC) isolates were recovered by a filter-hybridization method. Serotyping, PCR and pulsed-field gel electrophoresis (PFGE) showed that there was a distinct association between serotypes, stx profiles and animal species. CONCLUSIONS: Keeping animals together in pens, which enhances faecal-oral contact, is suggested as a possible explanation for the differences seen in stx occurrence. Sheep and cattle isolates are distinctly different in serotype and stx profile although isolated from the same farm, and are more related to isolates within the same serotype with the same stx profile than to isolates with different serotype from the same farm. SIGNIFICANCE AND IMPACT OF STUDY: The study supports the animal-host relationship hypothesis suggested in other studies and indicates that the STEC sheep reservoir in Norway may not pose a serious public health risk.     

Seroprevalence and Potential Risk Factors for Brucella Spp. Infection in Traditional Cattle,Sheep and Goats Reared in Urban,Periurban and Rural Areas of Niger

Introduction

In Niamey, Niger, interactions within the interface between animals, humans and the environment induce a potential risk of brucellosis transmission between animals and from animals to humans. Currently, little is known about the transmission of Brucella in this context.

Results

5,192 animals from 681 herds were included in the study. Serum samples and hygroma fluids were collected. A household survey enabled to identify the risk factors for transmission of brucellosis. The true adjusted herd-level prevalence of brucellosis ranged between 11.2% and 17.2% and the true adjusted animal-population level prevalence was 1.3% (95% CI: 0.9–1.8%) based on indirect ELISA test for Brucella antibodies. Animals aged of 1–4 years were found to be more susceptible than animals less than 1 year old (Odds ratio [OR] of 2.7; 95% CI: 1.43–5.28). For cattle, the odds of brucellosis seropositivity were higher in rural compared to the periurban areas (OR of 2.8; 95% CI: 1.48–5.17) whereas for small ruminants the risk of seropositivity appeared to be higher in urban compared to periurban areas (OR of 5.5; 95% CI: 1.48–20.38). At herd level, the risk of transmission was increased by transhumance (OR of 5.4; 95% CI: 2.84–10.41), the occurrence of abortions (OR of 3.0; 95% CI: 1.40–6.41), and for herds having more than 50 animals (OR of 11.0; 95% CI: 3.75–32.46). Brucella abortus biovar 3 was isolated from the hygromas.

Conclusion

brucellosis in Niger is a serious problem among cattle especially in the rural areas around Niamey and among sheep in the urban areas of Niamey. The seroprevalence varies across strata and animal species with important risk factors including herd size, abortion and transhumance at herd level and age at animal population level. For effective control of brucellosis, an integrated approach seems appropriate involving all stakeholders working in public and animal health.     

一株牛源阿卡斑病毒的分离鉴定

阿卡斑病毒(Akabane virus,AKV)是能引起牛、绵羊、山羊流产、早产、新生胎儿畸形的虫媒性RNA病毒。为了解家畜虫媒病毒在我国西南边境地区的分布和流行情况,本研究对中缅边境西盟县的52份牛抗凝血和140份血清(牛70份、羊70份)中的蓝舌病病毒(Bluetongue virus,BTV)、鹿流行性出血热病毒(Epizootic hemorrhagic disease virus,EHDV)、AKV等虫媒病毒进行检测与分离,通过ELISA及qRT-PCR方法检测病毒,通过核酸阳性抗凝血接种BHK细胞传代以分离病毒,通过设计特异性引物,扩增分离毒株S基因721bp片段及M基因816bp片段,通过克隆测序及中和试验以鉴定病毒,最终从38号牛的抗凝血中分离到一株AKV,TCID50为10-3.5/0.1mL,经比对,分离株S片段与日本KS-2/Mo/06毒株亲缘关系最近,核苷酸同源性为97.66%,M片段与中国DHL10M110毒株亲缘关系最近,核苷酸同源性为96.56%。本研究首次报告了从云南边境地区牛群中分离到AKV,证实了西南边境存在AKV的流行,为AKV在我国的流行病学和边境地区疫病风险防控提供了重要参考及有力依据。     

Diurnal and Seasonal Variations of Serum Enzyme Activity in Cattle and Sheep

In order to test the variation of enzyme activity in serum of cattle and sheep during the day, blood samples were taken at three hrs. interval from 6 a.m. to 9 p.m. The following enzymes were assayed: Aspartate aminotransferase (AspAT = GOT), alanine aminotransferase (AlAT = GPT), total lactate dehydrogenase (LDH), and a-hydroxybutyrate dehydrogenase (HBD). The variation between animals contributed by far to the greatest part of the total variation in clinical healthy animals. The time-of-day-dependant variation was less than 3 %, except for alanine aminotransferase. During the first two weeks of spring pasture serum aspartate and alanine aminotransferase levels were significantly raised in both cows and ewes, compared with serum levels of the same animals on indoor feeding. No such increase occurred in total lactate dehydrogenase.