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1.
Seventeen Streptococcus equi subsp. zooepidemicus strains isolated from camels and camel milk in Kenya and Somalia were identified by their cultural characteristics, by biochemical and serological reactions with the help of commercial identification systems and by molecular studies using a multiplex PCR. The isolates were further characterized by a PCR-mediated detection of size polymorphisms in the 16S-23S rDNA intergenic spacer region and the virulence gene szp and by amplification of the virulence gene cne. These molecular analysis are potentially useful in identifying and characterizing S. equi subsp. zooepidemicus strains of this origin and could possibly be valuable in epidemiological investigations.  相似文献   

2.
Rhodococcus equi has been isolated from the submaxillary lymph nodes of domesticated pigs, but little is known about the presence of R. equi in wild boars. The aim of the study was the evaluation of the incidence of R. equi in wild boars and the characterisation of them. Of 482 submaxillary lymph nodes of wild boars shot in 39 settlements throughout Hungary, R. equi was isolated from 60 specimens, and plasmid types of 82 isolates were examined. The isolates were tested for the presence of 15-17-kDa (VapA) and 20-kDa virulence-associated protein antigen (VapB) genes by polymerase chain reaction (PCR). Plasmid DNAs were isolated and analysed by digestion with restriction endonucleases to estimate size and compare their polymorphisms. None of the 82 isolates contained vapA gene but 21 isolates (25.6%) were positive for vapB gene showing 827bp product of the expected size in the PCR amplification. Sixty-one strains (74.4%) did not contain plasmid. The 21 isolates of intermediate virulence contained virulence plasmids that were identified as types 1 (1 isolate), 5 (16 isolates), 21 (1 isolate), and three new distinct plasmid variants (1-1-1 isolate), respectively. On the basis of restriction digestion patterns of plasmid DNAs, we tentatively designated the new variants as types 25-27, respectively. The prevalence of R. equi strains of intermediate virulence among the isolates originated from the submaxillary lymph nodes of wild boars (25.6%) is very similar to those of domestic pigs (26.8%) in Hungary, and plasmid type 5 is the predominating one in both groups. This is the first report of isolation of VapB-positive R. equi from wild boars in the world.  相似文献   

3.
In order to obtain Enterococcus faecalis from fur animals and evaluate its prebiotic properties,in this study,Enterococcus faecalis was isolated from the feces of healthy adult fur-bearing animals (mink,fox,raccoon dog),identified by morphological observation,biochemical test and 16S rRNA sequence analysis.The growth curve,acid production capacity and antibiotic sensitivity of the Enterococcus faecalis isolates were measured to evaluate their probiotic properties.Some strains were selected to determine their tolerance to temperature,artificial gastric juice and artificial bile salt.The results showed that five strains were Gram-positive,and their biochemical characteristics were basically consistent with the standard strains of Enterococcus faecalis,and they were identified as Enterococcus faecalis by 16S rRNA sequence analysis.The five strains all entered the logarithmic phase at 2 h after culture,and entered the stable phase at 8-10 h,and had weak acid production capacity.The resistance rate of the isolates to tetracycline and levofloxacin was 100%,followed by penicillin (80%),erythromycin (80%),gentamicin (80%) and chloramphenicol (40%).All the isolates were sensitive to ampicillin and vancomycin.Enterococcus faecalis from mink,fox and raccoon dog had strong tolerance to temperature below 60 ℃,artificial gastric juice with pH>3.0 and 0.3%-0.5% concentration of bile salt,but poor tolerance to temperature above 70 ℃,and artificial gastric juice with pH<3.0.In conclusion,five strains of Enterococcus faecalis from fur animals (mink,fox,raccoon dog) were obtained in this study.The isolated strains propagated rapidly,which were suitable for colonization and played a prebiotic role in fur animals' intestines,and had good prebiotic characteristics and stress resistance.They could be used as candidate strains for animal microbiological agents for further study.  相似文献   

4.
为获得毛皮动物源粪肠球菌,并评价其益生特性,本研究从健康成年毛皮动物(水貂、狐狸、貉)粪便中分离粪肠球菌,通过形态学观察、生化试验和16S rRNA序列分析等方法进行种属鉴定。测定分离菌株生长曲线、产酸能力、抗菌药敏感性,并挑取部分菌株测定其对于温度、人工胃液、人工胆盐的耐受能力。结果表明,分离菌株中共5株为革兰氏阳性菌,生化特性与粪肠球菌标准株基本相符,且经16S rRNA序列分析鉴定为粪肠球菌。5株菌均于培养后2 h进入对数期,8~10 h进入稳定期,且具有弱产酸能力。分离菌株对四环素、左氟沙星耐药性强,耐药率为100%,其次为青霉素(80%)、红霉素(80%)、庆大霉素(80%)、氯霉素(40%),对氨苄西林和万古霉素敏感。水貂、狐狸和貉源的粪肠球菌对于60 ℃以下温度处理、pH>3.0的人工胃液、0.3%~0.5%浓度的胆盐耐受能力较强,对70 ℃以上高温和pH<3.0的人工胃液耐受性差。综上所述,本研究共获得5株毛皮动物源(水貂、狐狸、貉)粪肠球菌,分离菌株繁殖较快,适合在毛皮动物肠道中定植并发挥益生作用,且具有较好的益生特性和抗逆性,可作为动物用微生态制剂的候选菌种进一步研究。  相似文献   

5.
OBJECTIVE: To determine whether isolation and virulence of Rhodococcus equi from soil and infected foals are associated with clinical disease. DESIGN: Cross-sectional and case-control study. SAMPLE POPULATION: R equi isolates from 50 foals with pneumonia and soil samples from 33 farms with and 33 farms without a history of R equi infection (affected and control, respectively). PROCEDURE: R equi was selectively isolated from soil samples. Soil and clinical isolates were evaluated for virulence-associated protein antigen plasmids (VapA-P) and resistance to the beta-lactam antibiotics penicillin G and cephalothin. Microbiologic cultures and VapA-P assays were performed at 2 independent laboratories. RESULTS: VapA-P was detected in 49 of 50 (98%) clinical isolates; there was complete agreement between laboratories. Rhodococcus equi was isolated from soil on 28 of 33 (84.8%) affected farms and 24 of 33 (72.7%) control farms, but there was poor agreement between laboratories. Virulence-associated protein antigen plasmids were detected on 14 of 66 (21.2%) farms by either laboratory, but results agreed for only 1 of the 14 VapA-P-positive farms. We did not detect significant associations between disease status and isolation of R equi from soil, detection of VapA-P in soil isolates, or resistance of soil isolates to beta-lactam antibiotics. No association between beta-lactam antibiotic resistance and presence of VapA-P was detected. CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of soil microbiologic culture and VapA-P assay results, it is not possible to determine whether foals on a given farm are at increased risk of developing disease caused by R equi.  相似文献   

6.
Rhodococcus equi isolates (204) obtained from foals (lung abscesses, lymph nodes, nasal discharge, rectal swabs) bred in 15 studs located throughout Hungary, isolates from soil samples, lymph nodes of pigs and from lesions of human patients were examined to determine genotypic diversity of virulence-associated plasmids. Isolates were tested for the presence of 15-17 kDa virulence-associated protein antigen (VapA) and 20k Da (VapB) genes by polymerase chain reaction (PCR). Plasmid DNAs were isolated and analysed by digestion with restriction endonucleases for estimation of size and comparison of polymorphisms. Of 146 clinical isolates from foals in 15 studs, 129 (88.3%) gave positive results for the VapA gene, showing a 564 bp product of the expected size in the PCR amplification. Of the 129 clinical isolates from foals, 123 contained an 85 kb type I plasmid and the remaining six contained an 87 kb type I plasmid. Of 48 soil isolates from two horse studs, 26 (54.2%) were positive for VapA gene and contained an 85 kb type I plasmid. Of three pig isolates, one was positive for VapA gene and contained an 85 kb type I plasmid, and the remaining two were positive for the VapB gene, showing a 827 bp product of the expected size in the PCR amplification and were R. equi of intermediate virulence which contained a 95 kb type S5 plasmid. Of the seven human isolates, five were positive for VapB gene by PCR, these were R. equi of intermediate virulence, which contained a 95 kb type S5 plasmid. These results revealed that virulent R. equi strains harbouring a virulence plasmid of 85 kb type I or 87 kb type I, which have been found in clinical isolates from Europe and North and South America, are widespread in Hungary. Furthermore, same intermediately virulence plasmid type was found in both human and pig isolates.  相似文献   

7.
The prevalence of virulent Rhodococcus equi in soil isolates from two horse farms in South Africa and nine clinical isolates from six foals, a foal foetus, a dog, and a monkey was investigated. The isolates were tested for the presence of virulence plasmid DNA and 15- to 17-kDa antigens by immunoblotting. Rhodococcus equi was isolated from almost all of the soil samples obtained from the two farms with 5.0 x 10(1) to 3.3 x 10(4) colony forming units per gram of soil. Virulent R. equi was isolated from three soil samples from one of the farms and appeared in 3.8% (three of 80 isolates), but not in any of the 182 isolates from the other farm. Of the three virulent R. equi isolates, one contained an 85-kb type I plasmid and two an 87-kb type I plasmid. Of nine clinical isolates from the foals, foal foetus, dog and monkey, five from the foals were virulent R. equi which expressed the virulence-associated antigens and contained a virulence plasmid 85-kb type I, and were all isolated from cases of pneumonia typical of that induced by R. equi in young foals living in widely separated areas in South Africa. The isolates from the other four foals, the dog and the monkey were avirulent R. equi.  相似文献   

8.
Five hundred and seventy-nine milk samples were collected from dairy cows on seven farms in Khartoum North area and one farm in Omdurman and examined by bacteriological cultures for the presence of streptococci. One hundred and ninety-three (33.33%) isolates were recovered and identified on the basis of bacteriological characteristics and biochemical reactions as: S. pyogenes, S. agalactiae, S. dysgalactiae, S. faecalis, S. faecium, S. bovis, S. equi, S. lactis and S. uberis. Fifty-seven isolates representing the preliminary identification were tested by the latex-agglutination test to determine the serological groups. It was found that 39 strains belonged to group B, 3 strains to group C. Four strains gave a weak reaction with group D sera and were identified by biochemical tests as S. uberis. Two isolates could not be identified by the available sera. The isolation of S. uberis, S. bovis, S. equi, S. lactis, S. faecalis, S. faecium and S. pyogenes from cows in the Sudan was reported for the first time.  相似文献   

9.
为探究缅甸蟒肺炎病因,本研究对海南文昌缅甸蟒养殖场的4条发病缅甸蟒进行了肺和心血组织的病原菌分离纯化、菌落及染色形态观察、生化、和16S rRNA分子鉴定,最后对各分离菌株进行了体外药敏实验。结果显示,全部分离株菌落及细胞形态特征一致,均为革兰氏阴性杆菌;糖醇发酵等生理生化特性与肠道沙门氏菌一致;根据16S rRNA基因的同源性比对,发现分离菌株与肠道沙门氏菌Salmonella enterica subsp.houtenae DSM 9221菌株同源性达到99%,可确定分离株全部为肠道沙门氏菌。通过23种抗菌药物的药物敏感性显示,所分离菌株对氟罗沙星等12种抗生素完全敏感。本研究结果表明海南文昌缅甸蟒肺炎病因为沙门氏菌感染,体外药敏实验可为该病的抗生素治疗提供使用参考。  相似文献   

10.
从青贮饲料中分离鉴定了39株乳酸菌,并研究了这些乳酸菌的特性。结果表明:分离菌株都是革兰氏阳性、过氧化氢酶阴性、兼性厌氧菌,根据其形态学和生理生化特性,可分为7组(A-G),A组、B组为片球菌属(Pediococcus),C组、D组和E组为肠球菌属(Enterococcus),F组和G组属于乳杆菌属(Lactobacillus)。  相似文献   

11.
羊伪结核病病原的分离鉴定   总被引:1,自引:0,他引:1  
从不同羊场的山羊颈部淋巴结脓肿处分离到5株革兰氏阳性、无荚膜、无芽胞的多型性球杆菌,其对青霉素等药物有很强的抗药性,对强力霉素高敏.根据其形态学、培养特性、生化特性及致病性试验、动物回归试验和血清学试验结果,判定所分离的5株菌为伪结核棒状杆菌.  相似文献   

12.
The plasmid profiles of virulent Rhodococcus equi strains isolated on three horse-breeding farms located in different parts of Hungary were investigated. From 49 soil samples collected on the three farms, 490 R. equi isolates (10 from each sample) were obtained and tested for the presence of 15- to 17-kDa antigens (VapA) by immunoblotting and PCR. Ninety-eight VapA-positive isolates were detected from 30 of the 49 culture-positive samples with a prevalence ranging from 13.1% to 23.2%. Of the 98 virulent isolates, 70 contained an 85-kb type I plasmid, 13 contained an 87-kb type I plasmid, and 15 contained an 85-kb type III plasmid which had been uniquely isolated from soil isolates in the United States. This study demonstrates that the virulent form of R. equi is very widespread in the soil environment of these stud farms in Hungary and the plasmid pattern is different from farm to farm.  相似文献   

13.
从新疆地区某驴养殖场获得了3株驴腺疫链球菌分离株HTP133、HTP123和HTP232.为了解这3株驴腺疫链球菌的生物学特性和确定其分子分型,本研究对其进行了生化特性、药敏特性的检测,对16S rRNA进行序列对比分析,并利用PCR扩增SeM等位基因和测序鉴定其基因型.研究结果表明3株分离菌均为马链球菌马亚种.药敏试...  相似文献   

14.
Two hundred and twelve Rhodococcus equi strains were isolated from soil, nasal and rectal swabs of horses and immunocompromised human patients in Hungary and serotyped using Prescott's serotyping system. One hundred and forty-seven strains (69.3%) belonged to serotype 1, 22 strains (10.4%) to serotype 2, 6 strains (2.8%) to serotype 3 and 1 strain (0.5%) to serotype 4. Serotypes 5, 6 and 7 were not found and 36 strains (17%) could not be typed. Serotype 1 (72%) was the type most commonly isolated from clinical samples of foals or from the soil of horse facilities. Six out of 8 R. equi strains from humans belonged to serotype 2, and two human strains were untypable. The data show that the prevalence of R. equi serotypes varies in different geographic areas of the country.  相似文献   

15.
OBJECTIVE: To evaluate sensitivity and specificity of a multiplex polymerase chain reaction (PCR) assay for simultaneous detection of Rhodococcus equi and differentiation of strains that contain the virulence-associated gene (vapA) from strains that do not. SAMPLE POPULATION: 187 isolates of R equi from equine and nonequine tissue and environmental specimens and 27 isolates of bacterial species genetically or morphologically similar to R equi. PROCEDURE: The multiplex PCR assay included 3 gene targets: a universal 311-bp bacterial 16S ribosomal RNA amplicon (positive internal control), a 959-bp R equi-specific target in the cholesterol oxidase gene (choE), and a 564-bp amplicon of the vapA gene. Duplicate multiplex PCR assays for these targets and confirmatory singleplex PCR assays for vapA and choE were performed for each R equi isolate. An additional PCR assay was used to examine isolates for the vapB gene. RESULTS: Results of duplicate multiplex and singleplex PCR assays were correlated in all instances, revealing high specificity and reliability (reproducibility) of the vapA multiplex assay. Of the pulmonary isolates from horses with suspected R equi pneumonia, 97.4% (76/78) yielded positive results for vapA. Seven of 50 (14%) human isolates of R equi yielded positive results for vapA. Six human R equi isolates and 1 porcine isolate yielded positive results for vapB. No isolates with vapA and vapB genes were detected. CONCLUSIONS AND CLINICAL RELEVANCE: The multiplex PCR assay is a sensitive and specific method for simultaneous confirmation of species identity and detection of the vapA gene. The assay appeared to be a useful tool for microbiologic and epidemiologic diagnosis and research.  相似文献   

16.
Rhodococcus equi isolates (462) obtained from 64 soil samples collected on 5 R. equi-endemic horse-breeding farms and isolates from 100 infected foals in Texas were examined to determine the prevalence and genotypic diversity of virulence-associated plasmids. Isolates were tested for the presence of 15-17-kDa virulence-associated protein antigens (VapA) by immunoblotting and virulence-associated plasmids by PCR. Plasmid DNAs were isolated and analyzed by digestion with restriction endonucleases for estimation of size and comparison of polymorphisims. Rhodococcus equi were isolated from soil of all 5 farms; however, virulent R. equi were only isolated from 3 of the 5 farms and represented 18.8% (87 of 462) of total isolates. Of the 87 virulent soil isolates, 56 (64.5%) contained an 85-kb type I plasmid, 23 (26.4%) an 87-kb type I plasmid, 7 (8%) a newly defined 85-kb type III plasmid (Tx 43), and 1 (1.1%) a newly defined 85-kb type IV plasmid (Tx 47). Of the 100 isolates from infected foals, 96 were virulent. Of the 96 virulent isolates, 51 (53.1%) contained an 85-kb type I plasmid, 39 (40.6%) an 87-kb type I plasmid, 4 (4.2%) an 85-kb type III plasmid (Tx 43), and 2 (2.1%) an 85-kb type IV plasmid (Tx 47). There are at least 4 different R. equi virulence-associated plasmids in Texas, 2 of which have not previously been described. Based upon virulence plasmid typing, there is geographic diversity among isolates of R. equi from clinical and environmental samples on horse-breeding farms in Texas. There is not a strong correlation between the presence of virulent R. equi in farm soils and the R. equi disease status of those farms.  相似文献   

17.
Rhodococcus equi has a low pathogenicity in cattle, but it occasionally causes lymph node granulomas, which are detected at abattoir post mortem inspection, and must be distinguished from tuberculous granulomas. Lymph node lesions were detected in 6719 cattle, from a total of 3,263,622 cattle examined post mortem in abattoirs, in the Republic of Ireland, during 1997 and 1998. Histological examination was performed on all lesions, principally for the purpose of identifying animals with tuberculosis. A total of 1122 of the lesions were cultured on blood agar and on Stonebrinks and Lowenstein-Jensen medium containing pyruvate, because the histological findings were difficult to interpret or were suggestive of R. equi infection. R. equi was isolated from 264 lesions. Almost all of the R. equi granulomas were confined to a single lymph node, and were present predominantly in the retropharyngeal, bronchial and mediastinal lymph nodes. R. equi granulomas were present in a significantly higher proportion of the lesions detected in steers and heifers compared to cows. The prevalence in the total population of 3.3 million cattle examined post mortem was 0.008%. The 15-17kDa antigens, associated with virulence in this organism, and the 20kDa antigen, associated with intermediate virulence, were not detected in isolates from 146 cattle, analysed by immunoblot assays. A PCR assay to detect the plasmid gene encoding the 15-17kDa antigens was also negative for isolates from these 146 animals. Plasmids were not detected in 30 isolates which were examined.  相似文献   

18.
从贵州省临床疑似鸭传染性浆膜炎发病鸭鹅中分离病原菌,经细菌分离培养、细菌形态、培养特征及生化试验,初步鉴定出疑似鸭疫里默氏杆菌(Riemerella anatipestifer,RA)20株,经PCR和动物接种试验,其中9株鉴定为RA。对不同地区分离到的这9株菌进行血清型鉴定和15种常规抗菌药物的药敏试验。结果发现,9株RA中4株为血清2型,其余5株暂未鉴定出血清型;9株分离株中,对吡哌酸、链霉素、卡那霉素和红霉素等耐药的菌株比例为80%以上,对先锋霉素高度敏感的菌株比例较高。结果表明,本次分离的RA菌株生化试验鉴定结果与其他地区存在一定差异,不同地区分离到的RA对不同抗菌药的敏感程度存在较大差异性。本研究结果为该地区鸭传染性浆膜炎的药物防制提供了很好的理论依据。  相似文献   

19.
本试验从河南省多个养猪场采集有明显呼吸道症状的猪肺脏和鼻拭子,进行支气管败血波氏杆菌(Bordetella bronchiseptica,Bb)的分离鉴定,通过病原的分离、培养对分离菌株进行形态观察、培养特性和生化试验鉴定,以及用支气管败血波氏杆菌flaB基因的特异性引物进行PCR鉴定,结果表明,有8株分离菌株扩增出了237 bp的特异性目的条带,结合形态观察及生化试验鉴定,确认成功分离到了8株猪源性支气管败血波氏杆菌;药敏试验结果显示,分离菌株对强力霉素、氯霉素、氟苯哒唑、氧氟沙星、四环素、卡那霉素、庆大霉素、奈丁酸和阿米卡星高度敏感。  相似文献   

20.
本实验从重庆某肉牛场肺炎患牛肺脏中分离一株革兰氏阳性双球菌,为进一步确定该菌株的分类地位,本研究对其进行细菌学分类鉴定。通过细菌培养特性、菌落形态观察、生化试验和PCR鉴定等研究表明,该分离菌与羊创伤球菌(H.ovis)(CCUG37441)特性相近;其16S rRNA序列与H.ovis标准株同源性达99.8%。药物敏感性试验和动物试验表明,该菌对菌必治最敏感,不致死小白鼠。  相似文献   

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