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1.
Seven group B streptococcal cultures isolated from three horses reacted with group B-specific antiserum, were CAMP positive, pigmented and showed the typical biochemical properties of Streptococcus agalactiae. The identification could be confirmed by PCR amplification of the 16S rRNA gene and a subsequent RsaI restriction pattern typical for S. agalactiae. In addition, the isolates were identified by amplification of species specific parts of the 16S rRNA gene, the 16S-23S rRNA intergenic spacer region and by amplification of the CAMP-factor (cfb) gene. Six isolates could be classified as serotype III/Rib, one isolate as serotype Ia/cbeta. The occurrence of the protein antigens Rib and cbeta could be confirmed by PCR amplification of the respective genes. The six isolates of serotype III/Rib were hyaluronidase negative, had a hylB gene with a size of 4.6 kb and an insertion element IS1548 of 0.98 kb. The isolate of serotype Ia/cbeta was hyaluronidase positive, had a hylB gene with a size of 3.3 kb and no insertion element IS1548. In addition, all seven isolates had the insertion element ISSag2 and the gene lmb encoding the laminin binding surface protein Lmb and the gene scpB encoding C5a peptidase. According to the present results the group B streptococci isolated from horses showed characteristics of human isolates of this species.  相似文献   

2.
The 16S r RNA gene of 49 streptococci of serological group B isolated from various origins was amplified by polymerase chain reaction (PCR) and subsequently digested with the restriction enzymes Rsa I and Msp I. The restriction profiles of all group B streptococci appeared to be identical indicating no intraspecies sequence variations of this gene. A fragment of the gene of two group B-streptococcal reference strains, including the hypervariable V2 region, could be amplified by PCR and sequenced. The sequence appeared to be identical and allowed the design of species-specific oligonucleotide primers. The primer pair used produced an amplicon with a size of 1250 bp and correctly identified all 49 group B-streptococci investigated but none of the control strains of various species and serogroups. This primer could be used in a multiplex PCR and allowed a rapid identification of bacteria of this species.  相似文献   

3.
Cell surface hydrophobicities of streptococci of serological group B were determined by the adherence of the bacteria to hexadecane droplets. A significant adherence to hexadecane was observed with the group B streptococcal type reference strains Ib, V, Ic, R and X, but not with those of serotype Ia, II, III and IV. Cultivation of the bacteria in microcapsule-inducing media reduced the hexadecane adherence properties. The adherence to hexadecane was not related to fibrinogen binding properties of the cultures. Screening a large number of group B streptococci isolated from humans and bovines revealed that those with polysaccharide type antigen alone were generally hydrophilic, those with protein antigen alone or with protein antigen in combination with polysaccharide antigen were mostly hydrophobic. Cultivation of the bacteria under microaerobic conditions or after a single mouse passage enhanced microcapsule production and correspondingly reduced the hexadecane adherence values. Treatment of the bacteria by guanidinium chloride or by neuraminidase enhanced the hexadecane adherence. The hydrophobic component on group B streptococcal surface appeared to be partly inactivated by heat or proteolytic treatment of the bacteria.  相似文献   

4.
Direct immunofluorescence (IF) was used to assess cross-reactivity among 41 laboratory strains representing 11 serotypes of avian mycoplasmas. All the strains could be separated into distinct serotypes except the C-O-D-P group, which showed cross-relatedness unlike that demonstrated by other serological methods. With two exceptions, serotype C strains consistently cross-reacted with only the serotype P conjugate; the serotype O strain cross-reacted with the P and C conjugates. The two serotype C exceptions were found to be misclassified, as was the serotype P strain. Direct IF was found to be a quick, reliable method for measuring serological relatedness.  相似文献   

5.
The present study was performed to investigate both the identity and the source of the bacteria responsible for a fatal septicaemia observed in a group of three subadult emerald monitors (Varanus prasinus Schlegel 1839). The emerald monitors were necropsied and examined by light microscopy, including immunohistology, and by electron microscopy. Tissue samples were additionally submitted for bacteriological, virological and parasitological examinations. The virological and parasitological results were noncontributory, whereas the bacteriological investigation resulted in the isolation of gram-positive cocci which were characterized biochemically and serologically and by molecular analysis. The death of the emerald monitors was caused by a partially leukocyte-associated septicaemic infection with streptococci of serological group B of serotype V. Phenotypically and genotypically identical group B streptococci were isolated from the intestine of subadult mice, obtained from the feed used for the monitors. The genotypical characterization included an identical DNA fingerprint of strains of both origins, indicating the epidemiological relation between the feeding mice and the infections of the monitors.  相似文献   

6.
The 16S rRNA gene of 39 S. equi subsp. zooepidemicus strains and two S. equi subsp. equi strains was amplified by polymerase chain reaction and subsequently digested with the restriction enzyme Hinc II. A restriction profile with two fragments with sizes of 1250 bp and 200 bp could be observed for both S. equi subsp. equi strains and for 30 of the 39 S. equi subsp. zooepidemicus strains indicating a sequence variation within the V2 region of the 16S rRNA gene of the remaining nine S. equi subsp. zooepidemicus isolates. A segment of the 16S rRNA gene including the hypervariable V2 region of 11 S. equi subsp. zooepidemicus and two S. equi subsp. equi could be amplified by PCR and sequenced. The sequence of the V2 region of eight S. equi subsp. zooepidemicus strains appeared to be identical or almost identical to the sequence of the two S. equi subsp. equi strains. The sequence of the remaining three S equi subsp. zooepidemicus strains differed significantly from the sequence of S. equi subsp. equi. These differences allowed a division of S. equi subsp. zooepidemicus strains into two 16S rRNA types and might possibly have consequences for the taxonomic position of these phenotypically indistinguishable strains of one subspecies. A molecular typing could additionally be performed by amplification of the gene encoding the 16S-23S rRNA spacer region. A single amplicon of the spacer gene of 1100 bp could be observed for one S. equi subsp. zooepidemicus, an amplicon of 950 bp for two S. equi subsp. equi strains and 10 S. equi subsp. zooepidemicus strains, a amplicon of 780 bp for 27 S. equi subsp. zooepidemicus strains and a single amplicon of 600 bp for one S. equi subsp. zooepidemicus strain. The variations of the V2 region of the 16S rRNA gene and the size variations of the 16S-23S rRNA spacer gene were not related to each other. Both variations could be used for molecular typing of this species, possibly useful in epidemiological aspects.  相似文献   

7.
During the period from 1985 to 1988 we determined 228 strains of streptococci isolated from samples of various sorts of biomaterials, mainly animals. From this set of streptococci we classified 207 strains into serological groups according to the Lancefield classification and about 30% strains into species by means of serological and biochemical methods. Most of the strains were allocated to group C (37.28%) and group Q (17.39%). 89 streptococci strains originated from pigs, 40 strains from horses, 13 from cattle, 12 from dogs, 9 from poultry and 8 from coypu. The other streptococci strains originated from other animal species or from different material. Most serological groups of streptococci were determined in pigs, less in cattle (7), in poultry (6), in dogs (6), in horses (5) and in coypu (3). Streptococci of the serological group Q were determined in as many as 9 animal species, group C in 8 species and group G in 6 species.  相似文献   

8.
The genetic variability of a gene coding for an outer membrane lipoprotein (omlA) was used to develop a PCR typing system for Actinobacillus pleuropneumoniae. Sequence differences in the middle region of the gene divided the A. pleuropneumoniae serotypes in five distinct groups. Group I included serotypes 1, 9, 11 and 12 (omlA l), Group II consisted of serotypes 2 and 8 (omlA II), Group III included serotypes 3, 6 and 7 (omlA III), Group IV (omlA IV) consisted of serotype 4 and Group V of serotypes 5a, 5b and 10 (omlA V). The sequence differences were utilized to construct PCR primers specific for each group, except of Group IV, as the amplicon of serotype 4 could be separated from Group III by size. Together with a PCR apx typing system, the omlA PCR typing system could discriminate the majority of A. pleuropneumoniae serotypes of biovar 1 except of serotypes 1, 9 and 11 and serotypes 2 and 8. The PCR typing system was tested on 102 field strains of A. pleuropneumoniae isolated from lungs of diseased pigs. The serotyping results of the investigated field strains were in agreement with the apx and omlA gene patterns found in the reference strains of the bacteria, with the exception of the omlA gene of five strains of serotype 8. To examine the apx and omlA gene pattern of tonsil isolates, the PCR typing system was tested on a total of 280 A. pleuropneumoniae field strains isolated from tonsils of pigs. Agreement between serotyping and DNA typing was found in 96% of the isolates using the apx gene patterns and in 89% of the isolates using the omlA gene. The same serotype specific apx/omlA gene pattern was thus found in the majority of the tonsil isolates and in isolates from diseased lungs. Most of the differences in the omlA gene were found in 18 tonsil isolates of serotype 12. The omlA/apx PCR typing system described in the present study makes it possible to determine the type specificity of the majority of A. pleuropneumoniae isolates by simple PCR technique and enables phenotype independent characterization of isolates non-typable by serotyping.  相似文献   

9.
The integron content of 52 DT104/U302 phage type strains and 53 non-DT104/U302 strains of Salmonella enterica serotype Typhimurium (S. Typhimurium) was studied in PCR experiments using a 5'-CS/3'-CS primer pair (Lévesque et al., 1995). Forty-three out of 44 streptomycin- and/or ampicillin-resistant DT104 and related phage type strains were found to carry a 1 kb and/or 1.2 kb long integron. The other resistance markers did not affect the number and size of integrons; no integron-free multidrug-resistant (MDR) DT104 strains were found. The two large groups of DT104 strains (Felix-Callow's phage types 2 and 2c) proved to be identical in respect of integron patterns (IPs), supporting the views of those authors who consider DT104 a single clone. Strains of human and animal origin did not differ from each other in their IPs. Within the non-DT104 phage types, ampicillin- and/or streptomycin-resistant, integron-free MDR strains were also found. Based on amplicons varying between 290 and 3500 bp an IP system was suggested. The commonest amplicon sizes in non-DT104 strains were 1450 and 2050 bp. The IPs of DT104 strains and of non-DT104 strains containing an integron of 1 and 1.2 kb size were stable. In contrast, the IPs of other non-DT104 strains showed a varying degree of instability. Integron loss was frequently associated with spontaneous plasmid elimination and changes of R-type among the descendants of a given strain.  相似文献   

10.
布氏杆菌为世界性具重要公共卫生意义的人兽共患疫病原，分6个种。建立种间及种株间安全敏感、经济有效的快速鉴别诊断方法对布病防制及分子流行病学研究具有重要意义。布氏杆菌IS711和omp2基因具有种属特异性，可用于布氏杆菌的PCR分子诊断。其中IS711为转座因子，在不同种布菌种存在插入位置的多态性，外膜蛋白OMP2编码基因则存在反向重复序列及种株间的多态性。为此，分别采用复式-PCR、PCR和限制性酶切片段长多态性（RFLP）分析，对分属于B．mclitcnsis、B．suis和B．abortus的不同种布氏杆菌的不同种株，M5、M16、S2、S6和S19进行分子鉴别诊断。结果显示，根据IS711基因特定PCR扩增片段长多态性，可进行布氏杆菌种间的快速鉴别；而omp2编码基因PCR扩增片段PsrⅠ、KpnⅠ、NcoⅠ和Eco47 Ⅲ等4种限制酶片段长多态性，则可成为布氏杆菌菌株间特异的分子鉴别诊断标记，甚至疫苗株M5和野毒株M16之间的分子诊断标记。  相似文献   

11.
In characterising Mycoplasma agalactiae strains from various European countries and from Africa, a new insertion sequence (IS), ISMag1, which is related to IS of the family of IS30 insertion elements, has been identified by DNA sequence analysis and Southern blot hybridisation. ISMag1 has a size of 1515bp, and contains inverted repeats of 3bp and a gene encoding the putative transposase on a single open reading frame. ISMag1 is present only in the rarely isolated serotypes E, F, G and H of M. agalactiae, where it is found in 1 to approximately 30 copies. The different patterns obtained by hybridisation of a labelled probe of ISMag1 to genomic DNA cut with various restriction enzymes correlate to some extent to the different serotypes and to variations of the nucleotide sequences of the uvrC genes of the different strains. Based on uvrC sequences, the strains of M. agalactiae carrying ISMag1 form a cluster, separate from the other strains. IS patterns obtained with ISMag1 allow a fine subtyping of the serotypes E, F, G and H of M. agalactiae for epidemiological studies. The potential role of ISMag1 and of its copy numbers on virulence and persistence of the respective strains requests further studies.  相似文献   

12.
One hundred twenty-nine Brucella field strains isolated from cattle in Cantabria, Spain, from March 1999 to February 2003, were analysed by using the AMOS-ERY PCR assay and by Southern blot hybridisation with a probe from insertion sequence IS711. Most of the field isolates produced only the ery band in the AMOS-ERY assay and showed a hybridisation pattern identical to that exhibited by reference strains of biovars 5, 6 and 9 of Brucella abortus, but different from strain Tulya, belonging to biovar 3 of B. abortus. However, typing of these strains by standard methods demonstrated that they belonged to biovar 3 of B. abortus. These results indicated that B. abortus biovar 3 was not genetically homogeneous and at least could be divided in two. In one class, that we called biovar 3a, would be the Tulya strain, while the local field strains would belong to biovar 3b. Cloning and nucleotide sequencing of a DNA fragment containing an IS711 copy exclusive of the B. abortus field strains from biovar 3b and reference strains from biovars 5, 6 and 9, revealed the existence of a 5.4 kb deletion close to an IS711 copy. Based on these data, we designed a new primer, which together with the IS711 AMOS primer produced a PCR fragment of 1.7 kb only from the isolates of biovars 3b, 5, 6 and 9 of B. abortus. No amplification products were produced with these primers from strains of the rest of species and biovars of Brucella and from bacteria phylogenetically close to Brucella analysed in this work. Addition of this primer to the AMOS-ERY PCR primer cocktail allows the positive distinction of B. abortus biovars 3b, 5, 6 and 9 from the rest of Brucella species and biovars.  相似文献   

13.
By PCR using the ant(3")-Ia primer pair the aadA gene was detected in 34 streptomycin- and spectinomycin-resistant Salmonella enterica serotype Typhimurium strains. Out of them 12 belonged to DT104 and 22 to non-DT104 phage type. Using different primer combinations it was demonstrated that this gene was integron-associated in all cases: in the DT104 strains it was generally contained by a 1 kb integron while in the majority of the non-DT104 strains by a 2.05 kb (less often by a 1.9 or 1 kb) integron. In the case of integrons carrying multiple cassettes the cassette containing the aadA gene was located closer to the 3' end of the integron. The aadA genes of DT104 and non-DT104 strains were different: in the former group the aadA2 gene, while in the latter group (constituted by strains of five different phages types as well as unclassifiable and untypable strains) the aadA1 gene could be identified. The RH50/RH51 primer pair described by Collis and Hall (1992) proved to be suitable for rapid discrimination between the aadA1 and aadA2 genes on the basis that the RH51 primer bound exclusively to the aadA2 gene.  相似文献   

14.
动物蓝舌病毒L2基因克隆及序列分析比较   总被引：2，自引：0，他引：2  
对 15株中国动物蓝舌病毒血清 1型 (BTV- 1)野毒株及 1株弱毒疫苗株 L 2基因进行了克隆和测序 ,并进行了系统进化分析。中国 BTV- 1型毒株分为 2个组 :分离年代最早的 Y86 3毒株 (1979年 )为 组 ;1996年以后分离的 14株毒株为 组。 2组之间的同源性是 91.6 %。 组又分为 4个谱系 ,疫苗株 Vac F45与原始株 V6 5 8分别属于 组的第 1和第 3谱系 ,核苷酸同源性 98.6 %。由此表明 ,中国 BTV- 1型毒株在自然进化及鸡胚传代驯化过程中 ,L2基因发生了遗传变异。  相似文献   

15.
The cultural, morphological, biochemical, serological characteristics and antibiotic susceptibility of 25 Rhodococcus equi strains isolated from lungs and lung abscesses of pneumonic foals and 5 R. equi strains isolated from immuno-compromised human patients were examined. All R. equi strains showed common cultural, morphological and biochemical characteristics both with conventional tests and on the basis of their enzyme profile. The R. equi strains examined were resistant to penicillins with the exception of ampicillin, to sulphamethazine and several strains also to sulphamethoxazole-trimethoprim. All strains were susceptible to erythromycin and rifampicin. The strains isolated from humans showed somewhat higher rate of antibiotic resistance to penicillin, cefotaxime, kanamycin, streptomycin, lincomycin, and oxytetracycline. The overwhelming majority (96%) of the equine isolates belonged to serotype 1 in Prescott's serotyping system, while the human isolates could not be serotyped.  相似文献   

16.
根据外膜蛋白基因中间部分的差异,毒素基因和荚膜基因的型特异性,建立3个多重PCR的分型体系,可将App1～12型分成11个模式,除9型和11型外完全区分。此分型体系用于3株野毒株的分型,得出的结果和血清学分型一致。对人工发病猪扁桃体、肺脏、鼻拭子各12份分型结果与已知血清型一致。将该分型系统直接用于临床病料的鉴定并分型,实验从35份临床可疑病料中检测出2份阳性,均为7型,从健康猪扁桃体350份中检测出5份阳性,一份为4型,一份为12型,一份为3型,2份为7型。  相似文献   

17.
检测鸭疫里默氏杆菌（Riemerellaanatipestifer,RA）10个基因在不同菌株间的分布并进行序列分析,研究其在不同菌株中的保守性。分别选取8株RA的10个基因进行PCR扩增,扩增产物克隆于pMD18-T载体,进行序列测定和分析。结果显示：测定的8株RA菌株中均能检测到Lipid A、LuxE和TCTR编码基因,表明这些基因在不同血清型RA菌株中的保守性良好;TR基因仅从6株具有致病性的RA菌株中扩增得到,而2株非致病性RA菌株NJ1和NJ4未能扩增到,表明TR基因可能与RA菌株的致病性相关;IS1仅从6株血清1型和2型的RA菌株扩增得到,2株血清10型菌株均未扩增得到,提示IS1为血清10型菌株缺失基因。  相似文献   

18.
The biochemical and serological properties of 21 strains of Actinobacillus pleuropneumoniae biotype 2 isolated from haemorrhagic necrotic pleuropneumonia of swine were examined. For serologic typing, the indirect haemagglutination (IHA) and the double gel-diffusion tests were used. On the basis of their soluble surface antigens, our A. pleuropneumoniae biotype 2 isolates could be assigned to two proposed serotypes. Serotype 1 comprised 11 strains and serotype 2 comprised 10 strains. All strains contained two surface antigen components. In the strains belonging to serotype 1, one of the antigens was identical with the serotype-specific antigen of Pasteurella haemolytica T4. Both antigens of serotype 2 strains proved to be type-specific. Four strains received from Switzerland, including the holotype strain of A. pleuropneumoniae biotype 2, and three strains isolated from swine in the G.D.R. belonged to serotype 2. Both the double gel diffusion and the IHA tests detected a 2-way cross-reaction between biotype 1, serotype 2 and biotype 2, serotype 2 strains of A. pleuropneumoniae, which could be eliminated using cross-absorbed sera.  相似文献   

19.
The serological characteristicis of 14 strains assigned to serotype 5 were examined by the slide agglutination test, the indirect haemagglutination (IHA) test and by gel diffusion.All the strains possessed identical capsular antigenic determinants of polysaccharide (PS) nature and lipopolysaccharide (LPS) nature. However, based upon a capsular antigenic determinant of PS nature the strains could be divided in two subtypes. It is therefore proposed to refer to the H. pleuropneumoniae strains of serotype 5 to two subtypes: subtype a with strain K17 as the subtype strain and subtype b with strain L20 as the subtype strain.  相似文献   

20.
The serological identity of 234 strains of Yersinia pseudotuberculosis recovered from domestic animals and birds in New Zealand was determined by slide agglutination test. Thirty strains were also examined by tube agglutination test. The strains were isolated from cattle (56), sheep (8), deer (117), goats (13), pigs (7), rabbits (6), guinea pigs (5), and aviary species of birds (22). All strains were isolated from animals or birds which had died or shown signs of ill health and amongst which diarrhoea was a common feature. Serotype I accounted for 23% (53) of strains, serotype II for 13% (30) of strains and serotype III for 64% (151) of strains. It was concluded that further investigations on the prevalence and serological identity of strains recovered from clinically healthy animals mav provide useful information in assessing the significance of various serotypes as a cause of disease in livestock.  相似文献   

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