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1.
Development of PCR-based techniques to identify porcine transmissible gastroenteritis coronavirus isolates. 总被引：3，自引：1，他引：2
R D Woods 《Canadian journal of veterinary research》1997,61(3):167-172
Sixteen isolates of transmissible gastroenteritis virus and one isolate of porcine respiratory coronavirus were characterized using RT-PCR amplification of 4 antigenic subsites in the site A epitope on the TGEV spike gene. The PCR products were digested with restriction enzymes Sau3AI and SspI and the sizes of the fragments were determined. Three different digestion patterns were observed with each enzyme. The recognition site for Sau3AI was missing in 1 isolate, was present in 13 isolates and 3 isolates had 2 sites. PCR-products with a single site had 3 different fragment sizes and the other isolates produced 2 fragments with different sizes. The SspI recognition site was not present in 5 isolates and 12 isolates had a single site that produced 2 fragments of different sizes. Based on the restriction fragment sizes, the 17 isolates were separated into 7 groups. Direct sequencing of the 455 bp nested set fragments demonstrated greater than 96% sequence homology among the 16 isolates and 100% homology in the 4 antigenic subsites in the conserved site A epitope. The groups are discussed in relation to their sequence homology and virulence. In vitro procedures have been developed to identify several porcine enteric coronavirus isolates at the strain level. 相似文献
2.
East ML Moestl K Benetka V Pitra C Höner OP Wachter B Hofer H 《Veterinary microbiology》2004,102(1-2):1-9
Sera from 38 free-ranging spotted hyenas (Crocuta crocuta) in the Serengeti ecosystem, Tanzania, were screened for exposure to coronavirus of antigenic group 1. An immunofluorescence assay indicated high levels of exposure to coronavirus among Serengeti hyenas: 95% when considering sera with titer levels of > or = 1:10 and 74% when considering sera with titer levels of > or = 1:40. Cubs had generally lower mean titer levels than adults. Exposure among Serengeti hyenas to coronavirus was also confirmed by a serum neutralisation assay and an ELISA. Application of RT-PCR to 27 fecal samples revealed viral RNA in three samples (11%). All three positive fecal samples were from the 15 juvenile animals (<24 months of age) sampled, and none from the 12 adults sampled. No viral RNA was detected in tissue samples (lymph node, intestine, lung) from 11 individuals. Sequencing of two amplified products from the S protein gene of a positive sample revealed the presence of coronavirus specific RNA with a sequence homology to canine coronavirus of 76 and 78% and to feline coronavirus type II of 80 and 84%, respectively. Estimation of the phylogenetic relationship among coronavirus isolates indicated considerable divergence of the hyena variant from those in European, American and Japanese domestic cats and dogs. From long-term observations of several hundred known individuals, the only clinical sign in hyenas consistent with those described for coronavirus infections in dogs and cats was diarrhea. There was no evidence that coronavirus infection in hyenas caused clinical signs similar to feline infectious peritonitis in domestic cats or was a direct cause of mortality in hyenas. To our knowledge, this is the first report of coronavirus infection in Hyaenidae. 相似文献
3.
Isolates of Streptococcus suis serotype 7 from diseased pigs in Denmark were characterized by ribotyping, pulsed field gel electrophoresis (PFGE), MIC-determinations and detection of resistance genes. Forty-one different ribotype profiles were found among the 103 isolates and could be divided into two main clusters. No obvious relationship between ribotypes and the clinical origin of the isolates could be observed. Fifty-four isolates, including all 24 isolates belonging to the main ribotype profile were examined by PFGE and 50 different profiles were found. A high frequency of resistance to erythromycin (41%), tetracycline (24%) and streptomycin (28%) was observed. Furthermore, almost all isolates (101) were resistant to sulphamethoxazol. Most isolates were susceptible to ceftiofur, chloramphenicol, florfenicol, penicillin, ciprofloxacin, trimethoprim and trimethoprim + sulphonamides. The tet(M) gene was found among 11 (44%) and the tet(O) gene in six (24%) of 25 tetracycline resistant isolates. The tet(L) and tet(S) genes were not detected in any isolates. The erm(B) gene was detected in 39 (93%) of 42 erythromycin resistant isolates. 相似文献
4.
Han Hu Changsheng Jiang Binzhou Zhang Nan Guo Zhonghua Li Xiaozhen Guo Yang Wang Binlei Liu Qigai He 《Journal of veterinary science (Suw?n-si, Korea)》2021,22(5)
BackgroundAntimicrobial peptides (AMPs) have been identified as promising compounds for consideration as novel antimicrobial agents.ObjectivesThis study analyzed the efficacy of cecropin B against Haemophilus parasuis isolates through scanning electron microscopy (SEM) and atomic force microscopy (AFM) experiments.ResultsCecropin B exhibited broad inhibition activity against 15 standard Haemophilus parasuis (HPS) strains and 5 of the clinical isolates had minimum inhibition concentrations (MICs) ranging from 2 to 16 μg/mL. Microelectrophoresis and hexadecane adsorption assays indicated that the more hydrophobic and the higher the isoelectric point (IEP) of the strain, the more sensitive it was to cecropin B. Through SEM, multiple blisters of various shapes and dents on the cell surface were observed. Protrusions and leakage were detected by AFM.ConclusionsBased on the results, cecropin B could inhibit HPS via a pore-forming mechanism by interacting with the cytoplasmic membrane of bacteria. Moreover, as cecropin B concentration increased, the bacteria membrane was more seriously damaged. Thus, cecropin B could be developed as an effective anti-HPS agent for use in clinical applications. 相似文献
5.
A collection of 77 Staphylococcus intermedius isolates from dogs and cats in Switzerland was examined for resistance to erythromycin. Resistance profiles for 14 additional antibiotics were compared between erythromycin-resistant and susceptible isolates. A resistance prevalence of 27% for erythromycin was observed in the population under study. Complete correlation between resistance to erythromycin, and to spiramycin, streptomycin, and neomycin was observed. The erythromycin-resistant isolates all had a reduced susceptibility to clindamycin when compared to the erythromycin-susceptible isolates. Both constitutive and inducible resistance phenotypes were observed for clindamycin. Ribotyping showed that macrolide-aminoglycoside resistance was randomly distributed among unrelated strains. This suggests that this particular resistance profile is not related to a single bacterial clone but to the horizontal transfer of resistance gene clusters in S. intermedius populations. The erythromycin-resistant isolates were all carrying erm(B), but not erm(A), erm(C), or msr(A). The erm(B) gene was physically linked to Tn5405-like elements known as resistance determinants for streptomycin, streptothricin, neomycin and kanamycin. Analysis of the region flanking erm(B) showed the presence of two different groups of erm(B)-Tn5405-like elements in the S. intermedius population examined and of elements found in Gram-positive species other than staphylococci. This strongly suggests that erm(B) or the whole erm(B)-Tn5405-like elements in S. intermedius originate from other bacterial species, possibly from enterococci. 相似文献
6.
R T Greene C L?mmler 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1992,39(7):519-525
125-I-IgG binding activities were observed with 15 (17%) of 90 S. intermedius isolates from dogs and 39 (95%) of 41 S. hyicus isolates from pigs. Binding activities were not detected with S. hyicus isolates from cows. The IgG binding proteins of 2 S. intermedius, 2 S. hyicus, and protein A from S. aureus Cowan I were isolated from their cell surfaces. The proteins precipitated with IgG preparations from human, rabbit, pig, dog and horse, but not with IgG from cow, mouse and chicken. This indicated that these IgG binding proteins could be classified as type I receptors. In addition, the isolated proteins from all 3 staphylococcal species precipitated with polyclonal chicken anti-protein A antiserum. SDS-PAGE, Western blotting and gel isoelectric focussing of the proteins revealed numerous bands in the 42,000 D range and acid isoelectric points. The isoelectric point of the isolated proteins from both S. intermedius cultures was slightly more acidic than those from S. hyicus and S. aureus. The present results indicate a close functional and antigenic similarity, if not identity, between IgG binding proteins of S. intermedius and S. hyicus, and protein A of S. aureus. 相似文献
7.
Eighty-one isolates presumptively identified as Pasteurella multocida from a variety of diseases in animals in Zimbabwe were subjected to biochemical characterization, capsular typing and RAPD analysis. The majority of isolates (over 80%) were assigned into named taxa and were predominantly P. multocida subsp. multocida and P. multocida subsp. septica, whilst the remainder were unassigned. Serogroup A was predominant among the three capsular types (A, B and D) of P. multocida detected. Three main RAPD clusters and three subclusters were observed among the majority of isolates (93.8%), whilst the remainder was found to be weakly related. Nine different groups of strains with similar RAPD profiles (100% similarity) were also observed. The reference strain of capsular serogroup F clustered with the reference strain of P. multocida subsp. septica, whilst all other serogroups clustered with reference strains of subsp. multocida and gallicida. Notably, serogroups A and D were observed to be closely related to the reference strain of subsp. multocida. The relationship between biotype, capsular type, host origin and disease manifestation was not clear-cut. However, most pig isolates of subsp. multocida clustered together as did most cattle isolates of subsp. multocida. RAPD tended to separate subsp. multocida from septica. 相似文献
8.
One hundred clinical isolates of Salmonella choleraesuis subsp. choleraesuis serovar dublin (Salmonella dublin) were examined for phage sensitivity, antibiotic resistance patterns, and plasmid content. Computer analysis of the lysis patterns observed by using 27 typing phages divided the S. dublin isolates into 26 groups. One lytic pattern (Designated pattern 16) contained 52% of the isolates examined whereas 16 isolates had unique patterns, and nine patterns had fewer than ten members. Although 14 antibiotic resistance patterns were observed among the 100 isolates, 79% of the isolates grouped in three major patterns. Seven plasmid groups were identified and designated A-G based on the large plasmids found in the isolates. Of the 100 isolates, 28 contained the plasmid profile of Group A, 28 were Group B, 7 were Group C, 34 were Group D, and 1 isolate each was observed in Groups E, F, and G. The strong association between antibiotic resistance pattern and plasmid type suggest that the drug resistance genes are plasmid borne. 相似文献
9.
Genotypic diversity in field isolates of Babesia bovis from cattle with babesiosis after vaccination
AE LEW RE BOCK JM CROFT CM MINCHIN TG KINGSTON RJ DALGLIESH 《Australian veterinary journal》1997,75(8):575-578
Objective To determine whether particular genotypes of Babesia bovis were common to field isolates obtained from cattle properties in Queensland where the B bovis vaccine had apparently failed.
Design A comparative study of polymerase chain reaction genotypes in different populations of B bovis .
Procedure Two polymerase chain reaction assays were applied to analyse DNA extracts of B bovis vaccine (K, T and Dixie strains) and 27 field isolates from 24 properties where disease outbreaks had occurred despite the use of the vaccine. To evaluate the stability of the genotypes identified, 11 of the field isolates were inoculated into experimental cattle that had either been previously vaccinated with T strain or not vaccinated.
Results No particular genotype of B bovis was responsible for the problems observed in previously vaccinated herds. None of the isolates had genotypes identical to the vaccine strains used. No geographic trends among the genotypes were observed. Isolates that originated from the same property also had different genotypes. Blood passage of the 11 field isolates in either previously vaccinated or nonvaccinated cattle did not alter the original genotype.
Conclusion No particular genotypes identified by the Bv80 and BvVA1 polymerase chain reaction assays could be associated with vaccine failures. 相似文献
Design A comparative study of polymerase chain reaction genotypes in different populations of B bovis .
Procedure Two polymerase chain reaction assays were applied to analyse DNA extracts of B bovis vaccine (K, T and Dixie strains) and 27 field isolates from 24 properties where disease outbreaks had occurred despite the use of the vaccine. To evaluate the stability of the genotypes identified, 11 of the field isolates were inoculated into experimental cattle that had either been previously vaccinated with T strain or not vaccinated.
Results No particular genotype of B bovis was responsible for the problems observed in previously vaccinated herds. None of the isolates had genotypes identical to the vaccine strains used. No geographic trends among the genotypes were observed. Isolates that originated from the same property also had different genotypes. Blood passage of the 11 field isolates in either previously vaccinated or nonvaccinated cattle did not alter the original genotype.
Conclusion No particular genotypes identified by the Bv80 and BvVA1 polymerase chain reaction assays could be associated with vaccine failures. 相似文献
10.
Feline infectious peritonitis (FIP) is a terminal disease of cats caused by systemic infection with a feline coronavirus (FCoV). FCoV biotypes that cause FIP are designated feline infectious peritonitis virus (FIPV), and are distinguished by their ability to infect macrophages and monocytes. Antigenically similar to their virulent counterparts are FCoV biotypes designated feline enteric coronavirus (FECV), which usually cause only mild enteritis and are unable to efficiently infect macrophages and monocytes. The FCoV spike protein mediates viral entry into the host cell and has previously been shown to determine the distinct tropism exhibited by certain isolates of FIPV and FECV, however, the molecular mechanism underlying viral pathogenesis has yet to be determined. Here we show that the FECV strain WSU 79-1683 (FECV-1683) is highly dependent on host cell cathepsin B and cathepsin L activity for entry into the host cell, as well as on the low pH of endocytic compartments. In addition, both cathepsin B and cathepsin L are able to induce a specific cleavage event in the FECV-1683 spike protein. In contrast, host cell entry by the FIPV strains WSU 79-1146 (FIPV-1146) and FIPV-DF2 proceeds independently of cathepsin L activity and low pH, but is still highly dependent on cathepsin B activity. In the case of FIPV-1146 and FIPV-DF2, infection of primary feline monocytes was also dependent on host cell cathepsin B activity, indicating that host cell cathepsins may play a role in the distinct tropisms displayed by different feline coronavirus biotypes. 相似文献
11.
The goal of the present study was to characterize, by ribotyping and restriction endonuclease analysis (REA), 35 phocine Bordetella bronchiseptica isolates and to ascertain their relationship to one another and to isolates acquired from other host species. Thirty-four isolates were obtained in Scotland during a 10-year period encompassing the 1988 epizootic; the remaining isolate was obtained independently in Denmark. All phocine isolates had an identical Pvu II ribotype unique from the 18 ribotypes previously detected in strains from heterologous hosts. Alternative restriction enzymes, useful for subgrouping strains within Pvu II ribotypes, also failed to discriminate among isolates from seals. The exclusive occurrence of a single ribotype of B. bronchiseptica in a particular host species has not been previously observed. Similarly, REA based on either HinfI or Dde I profiles did not reveal detectable polymorphisms, although unique patterns were readily distinguished among a limited number of isolates from other host species. This is the first report demonstrating the utility of REA using frequently cutting enzymes for discrimination of B. bronchiseptica strains. These data suggest that B. bronchiseptica-induced respiratory disease in seals along the Scottish shore may be due to the circulation of a single, unique clone. 相似文献
12.
Kaneshima T Hohdatsu T Hagino R Hosoya S Nojiri Y Murata M Takano T Tanabe M Tsunemitsu H Koyama H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(3):301-303
Canine respiratory coronavirus (CRCoV), which is more closely related to the bovine coronavirus (BCoV), has recently been detected in dogs. In this study, we examined whether BCoV was capable of infecting and exhibiting pathogenicity in dogs. Three 1-month-old pups were oronasally given field isolates of BCoV, and were kept together with 2 control animals. As a result, increases in BCoV-neutralizing antibody titers were confirmed in all pups in the challenged and control groups. Moreover, the virus gene was also detected in oral and rectal swabs by RT-PCR. These results indicate that BCoV infects dogs, and easily infects other dogs that are kept together. However, no clinical symptoms such as respiratory symptoms and diarrhea were observed. 相似文献
13.
为了更好地了解禽源沙门菌对四环素的耐药性及耐药基因分布,从不同来源的家禽样品中分离沙门菌,调查其对四环素的耐药性以及耐药菌株中8种四环素耐药基因[tet(A)、tet(B)、tet(C)、tet(W)、tet(M)、tet(D)、tet(K)和tet(L)]的携带情况.结果表明,18.8%的沙门菌分离株对四环素耐药,健康成鸡分离株对四环素的耐药性明显高于雏鸡、死胚或病禽分离株;四环素耐药株中tet(A)、tet(B)和tet(M)基因的携带比例分别为73.1%、11.5%和3.8%,说明沙门菌对四环素的耐药机制以tet(A)和tet(B)基因介导的主动外排为主.本研究首次在对四环素耐药的沙门菌中检测到tet(M)基因,说明tet(M)基因在沙门菌对四环素的耐药性方面也具有潜在的作用. 相似文献
14.
The relationship of severe acute respiratory syndrome coronavirus with avian and other coronaviruses
Jackwood MW 《Avian diseases》2006,50(3):315-320
In February 2003, a severe acute respiratory syndrome coronavirus (SARS-CoV) emerged in humans in Guangdong Province, China, and caused an epidemic that had severe impact on public health, travel, and economic trade. Coronaviruses are worldwide in distribution, highly infectious, and extremely difficult to control because they have extensive genetic diversity, a short generation time, and a high mutation rate. They can cause respiratory, enteric, and in some cases hepatic and neurological diseases in a wide variety of animals and humans. An enormous, previously unrecognized reservoir of coronaviruses exists among animals. Because coronaviruses have been shown, both experimentally and in nature, to undergo genetic mutations and recombination at a rate similar to that of influenza viruses, it is not surprising that zoonosis and host switching that leads to epidemic diseases have occurred among coronaviruses. Analysis of coronavirus genomic sequence data indicates that SARS-CoV emerged from an animal reservoir. Scientists examining coronavirus isolates from a variety of animals in and around Guangdong Province reported that SARS-CoV has similarities with many different coronaviruses including avian coronaviruses and SARS-CoV-like viruses from a variety of mammals found in live-animal markets. Although a SARS-like coronavirus isolated from a bat is thought to be the progenitor of SARS-CoV, a lack of genomic sequences for the animal coronaviruses has prevented elucidation of the true origin of SARS-CoV. Sequence analysis of SARS-CoV shows that the 5' polymerase gene has a mammalian ancestry; whereas the 3' end structural genes (excluding the spike glycoprotein) have an avian origin. Spike glycoprotein, the host cell attachment viral surface protein, was shown to be a mosaic of feline coronavirus and avian coronavirus sequences resulting from a recombination event. Based on phylogenetic analysis designed to elucidate evolutionary links among viruses, SARS-CoV is believed to have branched from the modern Group 2 coronaviruses, suggesting that it evolved relatively rapidly. This is significant because SARS-CoV is likely still circulating in an animal reservoir (or reservoirs) and has the potential to quickly emerge and cause a new epidemic. 相似文献
15.
Ribosome-rich extracts (RRE) were prepared by differential and ultracentrifugation from 25 bovine and 6 ovine isolates of Fusobacterium necrophorum (FN) including both biotypes A and B. A pooled rabbit antiserum was prepared against whole-cell and sonicated whole-cell bacterins of F necrophorum isolate FN 3080, and a 2nd pooled rabbit antiserum was prepared against a RRE of FN 3080. The RRE of the 25 bovine isolates were tested against the FN 3080 whole-cell antiserum, using Ouchterlony double-immunodiffusion procedures. One to 3 precipitin lines were observed with the 25 isolates. The individual bovine isolates were found to have lines of identity with 5 to 21 of the other 24 isolates. The 25 bovine isolates and the 6 ovine isolates were then compared, using the FN 3080 RRE antiserum. One to 3 precipitin lines were observed for the 31 isolates with the RRE antiserum, and lines of identity were observed between all 31 of the isolates. These results indicated that common antigens are present in the RRE from a wide variety of F necrophorum isolates including both A and B biotypes. 相似文献
16.
为了解潮霉素B预混剂临床驱除绦虫线虫的有效性和给药时间的合理性,依据兽药临床试验规范,试验选择了蠕虫自然感染皖西麻黄鸡824只,按要求随机分为3组,分别为潮霉素B预混剂治疗组284只,芬苯哒唑粉对照药物组284只,不治疗的感染对照组256只,试验周期根据临床治疗效果确定。结果显示,潮霉素B预混剂,推荐剂量10 mg/kg混饲,连续饲喂21 d,对鸡蛔虫和绦虫的粗计驱虫率分别为63%和26%,表现明显的驱除蛔虫作用(P0.05),连续饲喂42 d,对鸡蛔虫和绦虫的粗计驱虫率分别为100%和-13%,驱蛔虫效果极显著(P0.01);对照药物芬苯哒唑粉,50 mg/kg混饲,连续饲喂6 d,对鸡蛔虫和绦虫的粗计驱虫率分别为100%和44%,同样具有极显著的驱除蛔虫作用(P0.01),本试验中2种药物的驱蛔虫效果相当,对绦虫的驱除作用不明显(P0.05)。潮霉素B预混剂10 mg/kg混饲,连续饲喂42 d,可以驱净鸡蛔虫的感染,但对鸡绦虫感染无明显的驱除作用。 相似文献
17.
Tuomi J Rantamaki LK Tanskanen R 《Comparative immunology, microbiology and infectious diseases》2002,25(2):109-125
Infectivity of and immune responses to 28 Finnish Borrelia burgdorferi sensu lato isolates was studied in 3-4-week-old outbred NMRI and inbred BALB/c/Hy laboratory mice; rabbits were also inoculated. Twenty-one isolates were found to detectably infect mice. A variation among isolates in degree of infectivity was observed. Higher infection rate and higher average ELISA readings were recorded for intradermal than intraperitoneal inoculations. The results suggest differences between Borrelia genospecies in organotropism. The ear was frequently infected by representatives of all genospecies; among high infectivity experiments, this rate was highest, 100%, in infections by Borrelia afzelii. Further differences between genospecies specific organ distributions: B. burgdorferi sensu stricto and Borrelia garinii isolates seemed to infect the bladder relatively more frequently than B. afzelii did; B. afzelii isolates infected heart relatively more frequently than others did. Genospecies specific differences were demonstrated between antigens in reactivity, i.e. in their 'sensitivity' as reagents of ELISA and IFA methods to measure isolate specific immune responses. Antigens from two B. afzelii isolates differed clearly in sensitivity. 相似文献
18.
19.
A plasmid, pG3BS, containing a cDNA clone from the 5' coding region of the peplomer glycoprotein gene appears to be specific for enteric transmissible gastroenteritis virus (TGEV) strains and for live-attenuated TGEV vaccines. This cDNA probe is used to differentiate porcine respiratory coronavirus (PRCV) isolates from TGEV field and vaccine strains by a slot blot hybridization assay. Probe pG3BS also hybridizes to canine coronavirus (CCV) RNA but does not hybridize to antigenically related feline infectious peritonitis virus (FIPV) RNA. The RNAs of 13 enteric TGEV isolates from the United States, Japan, and England, 4 US-licensed live-attenuated TGEV vaccines, and antigenically closely related CCV were detected by pG3BS. The RNAs of FIPV and 3 US isolates of PRCV did not react with pG3BS but were detected by a TGEV-derived plasmid, pRP3. Pigs infected with either PRCV or TGEV test serologically positive for TGEV antibody by the serum neutralization test. Characterization of the virus circulating in a swine herd by the pG3BS probe will differentiate between an enteric TGEV and a respiratory PRCV infection. 相似文献
20.
Monospecific antisera were prepared in rabbits against canine coronavirus (CCV) and transmissible gastroenteritis virus of pigs (TGEV), and in 24 pigs and 3 cats against TGEV alone. Neutralizing antibody titres were higher for the immunizing than the heterologous virus, although cross-neutralization usually was detected. This confirmed that CCV and TGEV are distinct, but antigenically related coronaviruses. In sera from 41 dogs, CCV-neutralizing titres were on average 2.7 fold higher than TGEV-neutralizing titres, suggesting that CCV was the causal agent. Sera from 29 cats in colonies with feline infectious peritonitis (FIP) and known to contain TGEV-neutralizing antibody, were found to have titres 12.3 fold higher against CCV. The FIP virus (FIPV) is probably more closely related to CCV than TGEV as judged by antigens involved in virus neutralization.Antisera to two isolates of bovine coronavirus, three isolates of haemagglutinating encephalomyelitis virus, seven strains of avian infectious bronchitis virus and the 229E strain of human coronavirus all failed to neutralize CCV and TGEV. Thus CCV, TGEV and probably FIPV fall into a group of antigenically related agents, separable from other members of the family Coronaviridae, by both virus neutralization and immunofluorescence tests. 相似文献