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1.
A total of 323 isolates of Streptococcus suis recovered from diseased or healthy pigs in France were serotyped. The presence of virulence-related proteins, Muraminidase-Released Protein (MRP), Extracellular Factor (EF) and Suilysin was also studied in 122 isolates of capsular types 2, 1/2, 9, 7 and 3 to evaluate their implication in virulence of S. suis. Capsular types 2, 1/2, 9, 7 and 3 were the most frequently detected (93%), with 69% for the capsular type 2 alone. Capsular types 2, 1/2, 9, 7, 3, 1, 4, 8, 18, 10 and 12 were isolated from diseased pigs, whereas types 2, 7, 9, 1/2, and 3 originated from the nasal cavities or tonsils of healthy animals. Most of the S. suis type 2 isolates recovered from diseased pigs carried MRP+ EF- Suilysin- (46%) or MRP+ EF+ Suilysin+ (28%) phenotypes. The MRP+ EF- Suilysin- phenotype was also detected in 67% of S. suis type 2 strains isolated from healthy pigs. The production of the virulence-related proteins was less frequently found in S. suis types 1/2, 9, 7 and 3 recovered either from diseased or healthy pigs. In this study, all the capsular type 1/2 strains were MRP+ EF- Suilysin- and all the S. suis type 7 harboured an MRP- EF- Suilysin- phenotype. The MRP- EF- Suilysin- phenotype was found in S. suis types 2, 3, 7 and 9 isolated from septicaemia, meningitis, pneumonia, and pleurisy. These results suggest that the presence of these proteins should not be used as a single condition for classifying the virulence of a field isolate in France.  相似文献   

2.
Isolation and characterization of Streptococcus suis capsular types 9-22   总被引：7，自引：0，他引：7  
The incidence and biochemical patterns of Streptococcus suis capsular types 9-22 are presented. Of 148 untypeable (with types 1-8 antisera) isolates of S. suis recovered from diseased pigs, 10% were not capsulated. Of the remaining 134 isolates, only 53% belonged to capsular types 9-22; capsular types 22 and 9 were the most prevalent, representing 19% and 13%, respectively. Capsular type 15 (de Moor's group T Streptococcus) is reported here for the first time in North America since it was described in 1963 in Europe. Of 188 untypeable isolates recovered from clinically healthy pigs, 25% were noncapsulated. Of the remaining 141 isolates, 90% belonged to the new capsular types, and 87% were identified as 1 of 4 types: 17, 18, 19, and 21. Capsular types 12 and 20 were not detected among the Canadian isolates. Almost half of strains were arginine dihydrolase-negative, and 45% fermented mannitol, which is seldom a positive test with capsular types 1-8. Although some strains were negative with salicin or trehalose, none were negative for both sugars. Only 54% of isolates tested with 1 rapid multitest system were correctly identified as S. suis. A tentative biochemical profile that might be used with a microplate identification system is also presented. Biochemical identification using the conventional system instead of the rapid multitest system is preferable.  相似文献   

3.
猪链球菌是猪的一种重要病原菌,并且也会引起人的链球菌病。有35个荚膜血清型(1/21、~34),通常自发病或死亡猪体分离获得1,2,7,9型和14型菌株,其中2型是毒力最强的血清型。根据已知猪链球菌16 SrRNA及溶血素(sly)、谷氨酸脱氢酶(gdh)、荚膜多糖(cps)、胞壁蛋白或溶菌酶释放相关蛋白(mrp)、胞外因子(epf)编码基因序列设计特异性引物,建立猪链球菌群和1(14),2(1/2),7型和9型特异性PCR或多重PCR,建立2型致病性菌株和1型高致病性菌株毒力鉴定PCR或多重PCR,用于检测和鉴别临床病料和细菌分离物中的猪链球菌,具有高敏感性和高特异性,与其他致病菌及其他血清的猪链球菌型无交叉反应,为疫病诊断及流行病学的研究提供了快速、简便和有用的工具。  相似文献   

4.
Streptococcus suis is an important pig pathogen which is associated with respiratory problems, meningitis and less fre-quently with a variety of other conditions(Hommez et al. 1986). S. suis type 1 causes disease mainly in 1–2 week old pigs while serotype 2 is found commoaily in 2–22 week old pigs, S. suis type 2 is a zoonosis. It can cause meningitis and septicaemia in man (Christensen & Kronvall 1985). Several other serotypes of S. suis have also been identified on the basis of the capsular poly-saccharide (Perch et al. 1983, Hommez et al. 1986). We present a case where we isolated S. suis types 1 and 2 from the brain and lungs respectively of the same diseased suckling piglet. This i/s the first reported case of S. suis types 1 and 2 in Finland.  相似文献   

5.
In this study, an immunochromatographic strip (ICS) was developed for the detection of antibody against Streptococcus suis serotype 2 (SS2). Colloidal gold particles labeled with staphylococcal protein A (SPA), which can bind to the F(C) fragment of mammalian immunoglobulin, were used as the detector reagent. The capsular polysaccharide (CPS) of SS2 and affinity-purified IgG from a healthy naive pig were immobilized on test and control regions of a nitrocellulose membrane, respectively. The ICS was used to 1) detect anti-CPS antibody in 14 sera taken from 4 SS2-infected pigs, 24 sera from pigs hyperimmunized with SS2, and 68 sera from pigs inoculated or infected with bacteria other than SS2; 2) determine anti-CPS antibody titers of 20 positive sera for comparison with enzyme-linked immunosorbent assay (ELISA); and 3) detect anti-CPS antibody in 226 clinical sera taken from diseased pigs also for comparison with ELISA. An ELISA used as a reference test determined the specificity and sensitivity of the ICS to be 97.1% and 86.3%, respectively. There was excellent agreement between the results obtained by ELISA and the ICS (kappa = 0.843). Additionally, there was strong agreement between the results of bacterial isolation from pig tonsils and ICS test (kappa = 0.658). Because it is rapid and easy to use, the test is suitable for the serological surveillance of SS2 at farms.  相似文献   

6.
The production of muramidase-released protein (MRP), extracellular protein factor (EF) and hemolysin (suilysin) by 101 Canadian field strains of Streptococcus suis capsular type 2 is described. Most strains (72%) isolated from diseased pigs were MRP-EF- and only 1 strain was MRP+EF+. This strain was also the only 1 to produce the hemolysin. Thirteen strains (15%) were MRP+ EF- and only 3 strains were MRP* EF-. All the strains isolated from clinically healthy pigs as well as a bovine and 2 human isolates had a MRP-EF- phenotype. In addition, 7 strains (8%) had a MRPS phenotype, which had so far been described for S. suis capsular type 1. In conclusion, most Canadian field isolates of S. suis capsular type 2 tested in this study do not produce the virulence-related proteins described so far for this bacterial pathogen.  相似文献   

7.
猪链球菌2型毒力因子研究进展   总被引：1，自引：1，他引：1  
猪链球茵(SS)病是一种严重危害养猪业的人畜共患病,呈世界性分布.根据荚膜抗原特性的不同,猪链球茵被分为35个血清型(1/2型,1型～34型),其中以猪链球菌2型(SS2)流行最广,毒力最强.SS2主要的毒力因子有溶菌酶释放蛋白、胞外蛋白因子、荚膜抗原、溶血素等.然而,新近发现的一些与SS2致病性相关的基因序列和蛋白片段已经成为当前研究的重点和热点.在基因水平上的新发现主要有orf2毒力因子、89 kb毒力岛、转录调节因子、氨基酸通透酶、ABC转运子及表面锚定蛋白基因、反应调节因子RevS基因、纤连蛋白结合蛋白基因、编码噬茵体的基因序列Ssl和分泌性核酸酶SsnA基因等.蛋白水平上的新发现主要有脂磷壁酸的D-丙氨酰位点、自溶素、精氨酸脱亚氨酸酶系统、浑浊因子,38,45,39,44 ku蛋白,以及一些蛋白酶和纤维蛋白溶血酶原受体等.  相似文献   

8.
Streptococcus suis is an important pathogen of swine, causing meningitis, arthritis, polyserositis, septicemia, and sudden death in weaning piglets as well as fattening pigs. Recently, 3 molecular tests have been developed in our laboratory: a multiplex polymerase chain reaction (m-PCR) assay for the detection of S. suis species and serotypes 2 and 1/2, and 2 molecular typing methods, pulsed-field gel electrophoresis and an approach based on PCR amplification of a fragment of rRNA genes, including a part of the 16S and 23S genes and the 16S-23S rDNA intergenic spacer region (ISR), followed by restriction fragment length polymorphism (RFLP) analysis (ISR-RFLP). In the present study, we used these tests to analyze tonsil samples from clinically healthy pigs and to identify individual isolates of S. suis during epidemiologic investigations of 8 related herds with a history of septicemia caused by S. suis serotype 2. Capsular typing showed that 58% of the strains were nontypable. Of the 17 serotypes present, serotype 22 was the most prevalent. In the 7 farms without clinical signs on the day of sampling, we detected S. suis serotype 2 or 1/2, or both, in less than 5% of the pigs by m-PCR or by bacteriologic culture. In the 8th farm, on which 2 pigs had clinical signs of septicemia on the day of sampling, we detected S. suis serotype 2 or 1/2, or both, by m-PCR in the tonsils of 40% of fattening pigs (21 wk old) that lacked symptoms. Molecular typing of the serotype 2 strains showed a common origin of contamination in these herds, given that 1 pattern (C1) was detected in the isolates from 6 of the 8 herds. However, up to 4 patterns were associated with septicemia and sudden death. Several patterns of S. suis serotype 2 can be responsible for disease in the same herd. These molecular tools may be useful for confident studies of the transmission of S. suis, thereby contributing to the control of S. suis infection.  相似文献   

9.
A total of 142 strains from different serotypes of Streptococcus suis isolated in Spain from diseased pigs (88 strains) and healthy carrier pigs (54 strains) were studied for the presence of a muramidase released protein (MRP) and an extracellular factor (EF). The following five phenotypes: MRP+EF+, MRP+EF-, MRP-EF+, MRP+EF* and MRP*EF- were detected. A high percentage of S. suis serotype 2 strains isolated from diseased pigs (84 per cent) belonged to phenotype MRP+EF+, but this phenotype has also been noticed in other serotypes (serotypes 1, 1/2 and 14). Both proteins were detected in S. suis serotype 2 strains (26%) isolated from healthy carrier pigs and one of both proteins in serotypes 1 and 14 (phenotype MRP+EF*). The isolation of S. suis strains from healthy pigs which have shown both proteins may support the epidemiological significance of these carriers in the maintenance, transmission and distribution of virulent strains within and between swine farms.  相似文献   

10.
Rapid detection of Streptococcus suis serotype 2 in weaned pigs   总被引：5，自引：0，他引：5  
A survey to detect Streptococcus suis serotype 2 in 1,716 weaned pigs was done in Quebec. Forty-nine sow herds were included in this survey: in 26 herds, S suis serotype 2 had been isolated during the preceding 12 months and in 23 herds (control), the organism had not been detected during a previous study. Swab specimens of the nasal cavity and tonsils of pigs were obtained for bacteriologic culture, and S suis serotype 2 was easily detected by the use of brain-heart infusion agar containing a Streptococcus-selective supplement and 5% goat antiserum raised against S suis serotype 2. After measurement of the diameter of the precipitation zone of 539 isolates, a slide agglutination test was performed to identify the S suis serotype 2 isolates. The mean precipitation zone diameter obtained for group S suis serotype 2 was larger (P less than 0.001) than that for the group designated as "others". With slide agglutination test results as reference and on the basis of discriminant analysis to stimulate detection of S suis serotype 2, 93.1% of all isolates were correctly classified, using the precipitation zone diameter as unique classification criterion. Relative specificity was 94.5% and relative sensitivity was 88.7%. Use of the precipitation zone diameter on a quantitative basis led to the proposal of a simple and reliable technique to screen swine herds for S suis serotype 2 in weaned pigs. Nasal and tonsillar swab specimens were obtained and analyzed concurrently for S suis serotype 2. The organism was found in both sites in only 20.4% of 103 carrier pigs.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

11.
Isolation of Streptococcus suis using a selective medium.   总被引：4，自引：2，他引：2       下载免费PDF全文
A selective medium containing tryptic soy agar, 5% defibrinated bovine blood, crystal violet, nalidixic acid and gentamicin significantly improved the isolation rate of Streptococcus suis from tonsilar tissue of slaughtered pigs. Ninety-five percent of the S. suis isolates identified in Guelph were confirmed as S. suis in Copenhagen, but only six out of 21 isolates typed as capsular serotype 2 in Guelph were confirmed to possess serotype 2 antigen in Copenhagen. Sixty-four percent of the S. suis isolates were not typable within the current scheme of capsular serotypes from 1 to 13 and type 1/2.  相似文献   

12.
A blocking ELISA based on the monoclonal antibody (MAb) 1A7 was developed to detect antibodies against Mycoplasma suis. The MAb was produced by immunising BALB/c mice with recombinant MSG1 protein (rMSG1) from M. suis expressed in E. coli. Following identification by Western blotting, the MAb was purified and labelled with horseradish peroxidase. The parameters of the ELISA were optimised, and the cut-off value determined as 36.35% by analysing the percentage inhibition of M. suis negative serum. The sensitivity and specificity of the ELISA were 92% and 100%, respectively. In repeatability tests, the intra- and inter-batch variation coefficients were <10%. The results suggest this blocking ELISA is specific, sensitive and reproducible, and will be a valuable tool in the serodiagnosis of M. suis infection in pigs.  相似文献   

13.
Streptococcus suis isolated from pigs in Finland   总被引：6，自引：0，他引：6  
A total of 58 Streptococcus suis strains were isolated from deceased pigs submitted to the National Veterinary Institute, Regional Laboratory in Kuopio, Finland, over a 3 1/2 year period, most frequently from cases of pneumonia. The bacteria were isolated from cases of meningitis, sepsis, rhinitis, endocarditis and abortion. S. suis was also isolated from nasal cavity, lung and brain of some sick piglets without signs of inflammation. Further S. suis was detected in 12 out of 107 tonsils of healthy fatteners tested. S. suis strains were identified by biochemical methods followed by typing. The most common capsular types were 7, 3 and 2, respectively. Only one type 1 strain and no types 6 and 9 strains were found. All S. suis strains tested were sensitive to penicillin and ampicillin.S. suis is not uncommon in Finnish pig herds. S. suis may be regarded as a potentially pathogenic organism which under certain predisposing conditions may cause serious disease.  相似文献   

14.
This study was undertaken to determine the prevalence, capsular serotype, and antimicrobial susceptibility of Streptococcus suis isolated from slaughter pigs. Capsular serotype and antimicrobial susceptibility were determined by coagglutination test and agar dilution minimum inhibitory concentration, respectively. Streptococcus suis was isolated from 55 of the 406 palatine tonsillar samples tested (13.8%) and 14 of the 29 sampled herds (48.3%). Of the 55 isolates recovered from slaughter pigs, 26 (47.3%) were untypeable. Of the remaining 29 isolates, capsular serotypes 9 (9 isolates) and 16 (4 isolates) were the most common, followed by capsular serotypes 4 (3 isolates) and 7 (3 isolates). Every capsulated isolate was typeable and no palatine tonsillar sample yielded more than one serotype. Most of isolates were susceptible to low concentrations (MIC90) of amoxicillin (2 microg/mL), ceftiofur (1 microg/mL), and penicillin (1 microg/mL). No correlation was found between antimicrobial susceptibility and capsular serotype.  相似文献   

15.
Streptococcus suis capsular type 2 is still an important cause of economic losses in the swine industry. At the present time, vaccination of pigs against this infection is generally carried out with autogenous bacterins and results are equivocal. In this study, the protective effect of a live avirulent S. suis type 2 strain (#1330) which had induced a good protection in mice, was evaluated in swine. The experiment was performed in triplicate using 4 week-old piglets. A total of 15 piglets were vaccinated 3 times, 15 others were vaccinated 2 times, and 15 piglets were injected 3 times with sterile Todd-Hewitt broth. Using an indirect ELISA, an increase in the IgG response to S. suis antigens was noted in 27 of the 30 vaccinated piglets. On day 21 post-vaccination, all animals were challenged intravenously with a virulent S. suis type 2 strain (#999). In the 2 vaccinated groups, 26 animals were fully protected. Only 1 out of the 15 piglets vaccinated 3 times developed mild clinical signs. In the group vaccinated twice, 3 piglets showed clinical signs and 1 of them died after the challenge. In the control group, 7 animals died out of the 11 with clinical signs of infection. In conclusion, a protective immunity was observed in swine when using strain 1330. However, more studies are needed to assess the use of a live S. suis strain in a vaccine for pigs.  相似文献   

16.
Serum samples collected from breeder chickens ranging in age from 1 day to 55 weeks were tested for CAA antibodies by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescent antibody (IFA) test. The relationship of ELISA to IFA test was determined. The sensitivity of the ELISA relative to the IFA test was 82.64%, and the specificity of the ELISA relative to the IFA test was 56.25%. Agreement between the ELISA and the IFA test was highly significant (Kappa = 0.74, Z = 5.78). We concluded that the ELISA is as good as the IFA test for detecting CAA antibody in sera from chickens.  相似文献   

17.
The present study was undertaken to evaluate the ability of 33 Streptococcus suis capsular type 2 isolates to adhere to frozen sections of porcine lung. Twenty isolates originated from diseased pigs and 13 from the nasal cavities of clinically healthy pigs. All isolates from diseased animals adhered to lung sections; isolates from pneumonia adhered, in general, in greater numbers than isolates from meningitis. Only four isolates from clinically healthy animals showed a weak adherence to lung sections. Hydrophobic surface properties were also evaluated. All isolates tested appeared to possess a hydrophilic cell surface. The thickness of the capsular material correlated well with the degree of adherence. However, when the adherence capacity of a noncapsulated mutant was compared with that of the parent strain, it was found that the mutant strain had at least the same adherence capacity as the capsulated parent strain. The data suggest that S. suis capsular type 2 isolates involved in pathological conditions can adhere to porcine lung tissue. The adherence activity does not seem to involve hydrophobic interactions. The amount of capsular material seems to influence the adherence activity, but is probably not the only mechanism involved.  相似文献   

18.
Samples of ear scrapings, serum and diaphragmatic muscle were collected from 271 fattening pigs at the slaughterhouse. The scrapings were examined for the presence of mites, and tests for specific antibodies to Sarcoptes scabiei var suis in the serum and meat juice were made with an experimental ELISA. The cut-off value for the meat-juice ELISA was estimated at an optical density of 0.5 by receiver operating characteristic curve analysis, on the basis of the cut-off value for the serum ELISA of 0.4. The results of the three tests were used in a Bayesian model to estimate the characteristics of each test. The specificity of the tests of the ear scrapings was considered to be 1 and their sensitivity was estimated by Bayesian analysis to be 0.86, with a 95 per cent confidence interval (CI) of 0.73 to 0.99. The sensitivity of the meat juice ELISA (0.71, 95 per cent CI 0.6 to 0.8) and its specificity (0.77, 95 per cent CI 0.66 to 0.89) were comparable with the sensitivity (0.73, 95 per cent CI 0.6 to 0.8) and specificity (0.81, 95 per cent CI 0.69 to 0.95) of the serum ELISA.  相似文献   

19.
Streptococcus suis infection in swine. A sixteen month study.   总被引：9，自引：0，他引：9       下载免费PDF全文
A total of 349 isolates of Streptococcus suis retrieved from different tissues from diseased pigs were examined in this study. Only 48% of them could be categorized as one of serotypes 1 to 8 and 1/2. Among typable isolates, serotype 2 was the most prevalent (23%), followed by serotype 3 (10%). The majority of all isolates originated from lungs, meninges/brain, and multiple tissues. Forty-one percent of typable isolates and 33% of untypable isolates were retrieved in pure culture. Other isolates were found in conjunction with Pasteurella multocida, Escherichia coli, Actinobacillus pleuropneumoniae, Actinomyces pyogenes, and other streptococci. Typable S. suis isolates were more frequently isolated from pigs between five and ten weeks of age, while untypable isolates were mostly found in animals aged more than 24 weeks. No obvious monthly and/or seasonal variation of the prevalence of isolation of S. suis could be detected.  相似文献   

20.
The safety and protective efficacy of a horse antiserum raised against inactivated whole cell preparations of Streptococcus suis serotype 2 was investigated in pigs by experimental challenge. The antiserum was evaluated in two similar experiments each comprising 12 4-week-old pigs treated with 6 ml of antiserum the day before challenge and four pigs used as challenge controls. Pigs were infected by subcutaneous injection with approximately 10(11) colony forming units of S. suis serotype 2. Clinical disease in the pigs that could be attributed to infection with S. suis was reduced from 88 to 35% (P = 0.015). The percentage of pigs with lesions that could be associated with S. suis was reduced from 88 to 22% (P = 0.002) and isolation of S. suis serotype 2 was reduced from five (63%) out of eight pigs in the combined challenge control groups to 3 (13%) out of 23 pigs in the combined treatment groups. These results indicate that passive immunization of pigs may be a way to reduce or control S. suis serotype 2 infections in pigs.  相似文献   

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