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1.
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   

2.
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   

3.
At the Danish Veterinary Laboratory Streptococcus suis infections in pigs were diagnosed in 114 cases in 1995 and in 151 cases in 1996. Isolates were serotyped using specific antisera against type 1 through 28 and a total of 67 cases from 1995 and 113 cases in 1996 were tested for resistance to 11 antimicrobial agents. The majority of cases were lung diseases (57%), followed by septicaemia (16%), meningitis (15%) and endocarditis (8%). Almost 96% of the isolates could be typed using the 28 antisera. The most common serotype was serotype 2 (29%), followed by serotype 7 (17%), and serotypes 3, 4 and 8 (9–10%). The remaining serotypes were observed in frequencies of less than 5%. Serotype 7 was more commonly isolated from septicaemia than the other serotypes. Serotype 2 was more commonly isolated from pigs older than 4 weeks compared to the other serotypes. Most isolates were susceptible to amoxycillin+clavulanate, ampicillin, ceftiofur, enrofloxacin, penicillin, spectinomycin, tiamulin and trimethoprim+sulphadiazine. A high frequency (>30%) of resistance to tetracycline was observed. Among isolates of serotype 2, 9.7% were resistant to lincomycin and 12.9% to spiramycin. Among other serotypes 56.8% were resistant to lincomycin and spiramycin. The differences in susceptibility between isolates of serotype 2 and the other serotypes were statistically significant. Compared to a previous Danish study the distribution of serotypes of S. suis causing infections among pigs in Denmark has changed during the last 15 years.  相似文献   

4.
We developed a new molecular method of typing Streptococcus suis based on polymerase chain reaction (PCR) amplification of a large fragment of rRNA genes, including a part of the 16S and 23S genes and the 16S-23S intergenic spacer region (ISR), followed by restriction fragment length polymorphism (RFLP) analysis with RsaI or MboII endonuclease. The 16S-23S ISRs of 5 S. suis isolates were sequenced and compared. Size and sequence polymorphisms were observed between the S735 reference strain and the 4 wild-type strains. The genetic relationships between 138 independent S. suis strains belonging to various serotypes, isolated from swine or human cases, were determined. The discriminatory power of the method was > 0.95, the threshold value for interpreting typing results with confidence (0.954 with RsaI and 0.984 with RsaI plus MboII). The in vitro reproducibility was 100%. The strains isolated from humans were less genetically diverse than the strains isolated from pigs. For the first time, 2 molecular patterns (R6, M9) were significantly associated with S. suis serotype 2 strains. This genetic tool could be valuable in distinguishing individual isolates of S. suis during epidemiologic investigations.  相似文献   

5.
Streptococcus suis strains (n=411), isolated from diseased pigs in seven European countries were serotyped using specific antisera against serotype 1 to 28, and were phenotyped on the basis of their muramidase-released-protein (MRP) and extracellular-factor protein (EF) production. Overall, S. suis serotype 2 appeared to be most prevalent (32%), followed by serotype 9 (20%) and serotype 1 (12%). Serotype 2 was most frequently isolated in France, Italy and Spain, whereas serotype 9 was most frequently isolated in Belgium, The Netherlands and Germany. In the United Kingdom serotypes 1 and 14 were most frequently isolated. High percentages of S. suis serotype 1, 2, 1/2 and 14 strains, isolated from tissues associated with S. suis infections such as brain, serosa, joint, heart and organs expressed the EF-protein, indicating that in these serotypes expression of EF is likely to be associated with virulence. In contrast, strains belonging to serotype 7 and 9, isolated from tissues associated with S. suis infections did not produce EF. These results strongly suggest that in the serotypes 7 and 9 EF expression is not related to virulence. More than 80% of the S. suis serotype 9 strains produced an MRP* protein, a high molecular variant of the 136kDa MRP. Expression of MRP* in serotype 9 strains is possibly associated with virulence.  相似文献   

6.
The antimicrobial susceptibility of 151 clinical Streptococcus suis strains isolated from diseased pigs in Spain was determined by a microdilution method. Isolates were mostly susceptible to beta-lactam antimicrobials, aminoglycosides, enrofloxacin, novobiocin and spectinomycin. More than 87% of the S. suis isolates were resistant to tetracyclines, sulphonamides, macrolides and clindamycin. Strains of serotype 9 were significantly more resistant than strains of serotype 2 (P<0.05) to tylosin (94% versus 77%) and clindamycin (94% versus 64%). Eighty-seven percent of the S. suis isolates were resistant to at least four antimicrobials and nine isolates (6%) were resistant to at least six antimicrobials. The most frequently identified multidrug pattern involved resistance against tetracyclines, sulphonamides, macrolides and lincosamides, with 69% of the isolates exhibiting this resistotype. Fifteen out of the 22 strains of serotype 2 (68.2%), and 84 out of the 98 of the strains of serotype 9 (85.7%) exhibited this resistotype, indicating its widespread distribution among the strains of the two most frequently isolated serotypes.  相似文献   

7.
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   

8.
利用荧光标记技术,采用2对引物初步建立检测猪链球菌荧光DNA扩增片段长度多态性方法,结果表明12株猪链球菌扩增的多态性位点数从51～98条不等,该方法能够检测猪链球菌的多态性,区分不同血清型以及同一血清型不同特性的菌株,可用于菌株鉴定及流行病学研究中细菌源的追踪。  相似文献   

9.
The study was undertaken to determine the prevalence, in the nasal cavities, of Streptococcus suis in four to eight week old clinically healthy piglets. Streptococci biochemically compatible with S. suis were isolated from 94% of piglets and 98% of farms. Of the 782 isolates submitted to serotyping, only 164 (21%) were included in the nine official serotypes. These 164 typable isolates originated from 121 (31%) of the 388 piglets and from 36 (73%) of the 49 farms included in the study. The most frequent serotypes found in piglets were, in decreasing order, 3, 4, 8 and 2. Serotype 1 was not detected in this survey. As many as 32% of piglets were found positive for two different serotypes and three different serotypes were found in 1%.  相似文献   

10.
Hybridization studies using genomic DNA and a rDNA probe revealed genetic relatedness among reference strains of different Streptococcus suis serotypes. Although most serotype 22 isolates are biochemically atypical, the reference strain of capsular type 22 is genetically related to other S. suis serotypes, but not to Streptococcus pneumoniae. Using DNA digested with BamHI and BglII for ribotyping, some S. suis reference strains had common patterns, but this analysis mainly revealed variations in patterns of S. suis strains of different serotypes.  相似文献   

11.
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   

12.
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   

13.
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14.
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   

15.
A total of 154 feral pig carcases and 81 kangaroo carcases were examined for the presence of Salmonella, coliforms and total aerobic counts. Approximately 34% of pig carcases yielded one or more serotypes of Salmonella, while about 11% of kangaroo carcases were contaminated with salmonella. The results differed widely between sampling occasions. A total of 13 serotypes were isolated from feral pigs with S. anatum (31 isolates) and S. typhimurium (9 isolates) being the predominant serotypes. Coliforms were isolated from approximately 90% of carcases. The mean log10 coliform count on feral pigs was 4.39 +/- 1.45/g and the mean log10 total count was 6.15 +/- 1.15/g. About 21% of carcases were contaminated with more than 100,000 coliforms/g. A total 3 serotypes were isolated from kangaroos (S. bahrenfeld, S. binza, and S. onderstepoort). The mean log10 coliform count on kangaroos was 3.54 +/- 1.04. More than 50% of kangaroo carcases were contaminated with less than 100 coliforms/g. About 15% of carcases were contaminated with more than 10,000 coliforms/g. The mean log10 total count was 5.2 +/- 1.01/g.  相似文献   

16.
Streptococcus suis serotypes associated with disease in weaned pigs   总被引：5，自引：0，他引：5  
Streptococcus suis was recovered from 9 outbreaks of septicaemia and meningitis in weaned pigs between 1979 and 1983. Fifteen isolates from 7 outbreaks were identified as S. suis type 9, and 3 isolates from 2 outbreaks as S. suis type 2. Three further isolates of S. suis type 2 and an isolate of S. suis type 3 were recovered from cases of bronchopneumonia in weaned pigs from 4 other piggeries.  相似文献   

17.
A model of experimental Streptococcus suis infection was developed in young mice. Minimum lethal dose (MLD) values were calculated for four virulent serotypes (1/2, 1, 2, 3) of S. suis using this model. Temperature-sensitive (ts) mutants of S. suis serotypes 1/2 and 1-8 were isolated and characterized on the basis of their growth kinetics and reversion rates. Ts mutants of S. suis 1/2, 1, 2, and 3 were tested as vaccines against the virulent homologous and heterologous challenges in mice. The protection provided was evaluated by analyzing the clinical signs, death or survival. Homologous but not heterologous protection was noted in all mice vaccinated with the mutant strains. Ts mutants of S. suis 1/2 provided 100% protection against challenge by virulent strains of S. suis 1/2, 1, and 2.  相似文献   

18.
猪链球菌PCR检测技术研究进展   总被引：2，自引：2，他引：0  
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   

19.
Streptococcus suis is one of the most important swine bacterial pathogens causing economic losses. This report presents the serotype distribution of S. suis recovered from diseased pigs in Québec from January 2015 to June 2020. Serotypes 1/2 and 2 predominated, followed by serotypes 7, 3, 5, 4, 9, 1, and 14. Compared to previously reported data, very few changes could be observed concerning the serotype distribution, indicating a relative stability. Half of the untypable isolates did not belong to the species S. suis sensu stricto, as determined by recN polymerase chain reaction. Less than 10% of “real S. suis” isolates were untypable. The genetic diversity of S. suis serotypes 1, 2, and 14, as analyzed by multilocus sequence typing, was mainly represented by sequence type (ST)1, ST28, ST25, and ST94. All ST1 isolates (considered highly virulent) belonged to either serotype 1 or 14.  相似文献   

20.
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   

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