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1.
100 faeces samples of cattle were investigated in comparison to a recent commercially available Salmonella Rapid Test (OXOID) and a cultural standard method (non-selective enrichment in buffered peptone water, selective enrichment in RAPPAPORT-VASSILIADIS-medium) for presence of Salmonella. The Salmonella Rapid Test showed in positive results an accuracy ("sensitivity") of 94.7% and in negative results an assurance ("specificity") of 97.5% and is therefore suitable for rapid detection (within 2 days) of faeces sample of cattle with Salmonella.  相似文献   

2.
The present study was conducted to evaluate the sensitivity and specificity of an immunochromatography-based diagnostic kit for Salmonella. The analytical sensitivity of the test when using pure colonies of different Salmonella species was in the range of 1 X 10(4) to 1 x 10(5) colony-forming units per milliliter. The strip detected 19 of 22 strains of Salmonella spp. but failed to detect S. worthington, S. choleraesuis var. kunzendorf and S. johannesburg. The strip did not detect 27 different enteric bacteria, including Escherichia coli O157:H7, Campylobacter jejuni, Shigella sonnei, and Vibrio parahaemolyticus. In direct testing of feces (n = 66) from chickens infected with Salmonella typhimurium, the strip had a sensitivity of 12.3% and a specificity of 100%. Evaluation of the strip assay (n = 510) after sample pre-enrichment in 2% buffered peptone water (BPW) yielded a sensitivity of 93.8% and specificity of 89% when compared to isolation and identification with xylose-lysine-tergitol 4 (XLT4) selective plating media. Subsequent enrichment in Hajna tetrathionate (TT) broth yielded a higher sensitivity (94.7%) and specificity (96.8%). The agreement (kappa) between the strip test and isolation was 0.004 in direct fecal testing, 0.82 in BPW, and 0.89 in TT broth. The assay could detect Salmonella sp. as early as 18-48 hours during pre-enrichment and enrichment compared to isolation on XLT4, which required an overnight incubation step for the presumptive isolation and identification of Salmonella.  相似文献   

3.
试验使用GenBank中已知的鸟类细胞色素b(Cyt b)基因部分序列(1044 bp)(共13条序列,其中鸡形目4条、鸭科鸟类9条)作为本研究的数据集,并以鸡形目与雁形目(鸡/绿头鸭)的分歧时间(89.8 MYA)为锚定点,用核苷酸不同替代模型对鸭科的分子钟进行标定。雉科与鸭科间的分歧时间的估计值为116.3785 MYA("1+2TiTv"),雁属与5个鸭属间的分歧时间为63.8823 MYA("1+2TiTv"), 鸡与鹌鹑的分歧时间为37.6708 MYA("1+2TiTv"),灰雁、白额雁与鸿雁间的分歧时间的估计值为1.879331 MYA("1+2TiTv")。以上结果说明:用"1+2TiTv"模型分析得到的鸭科鸟类的分歧时间比较可靠;雉科与鸭科、雁属与鸭属两个接近基部类群的分歧时间发生在白垩纪(137-65 MYA),支持鸟类早期历史发生在白垩纪的观点。  相似文献   

4.
Strains of Salmonella isolated from animals in Germany (n = 878) were analysed for the presence of the spvD gene ("Salmonella plasmid virulence gene D") by DNA-DNA hybridization. The spvD gene was only detected in strains of serovars Typhimurium (93.3%), Enteritidis (97.1%), and Dublin (100%) as well as in two rough strains of Salmonella enterica. Salmonella isolates from mammals carried the gene more frequently (cattle 94.0%, horses 92.6%, pigs 73.7%) than those from birds (33.3%) or reptiles (4.5%). Due to its high prevalence in epidemiologically relevant salmonellae, the virulence factor spvD may represent a sensitive and specific target in various serovars for diagnostic or immunization strategies.  相似文献   

5.
To detect Bovine Virus Diarrhoea Virus (BVDV)-specific antibodies in cattle serum, plasma and bulk milk, a simple, reliable and rapid blocking ELISA ("Ceditest") has been developed using two monoclonal antibodies ("WB112" and "WB103") directed to different highly conserved epitopes on the non-structural peptide NS3 of pestiviruses. The test can be performed at high reproducibility using undiluted samples. In testing 1000 field serum samples, the ELISA showed a specificity and a sensitivity relative to the virus neutralization test of 99% and 98%, respectively. The blocking ELISA is able to detect specific antibodies in serum obtained 12 days after an acute infection and in serum of vaccinated and challenged animals. A frequency distribution diagram, obtained by testing almost 1800 random Dutch field serum samples, showed a clear separation between a negative population (maximum frequency of the % inhibition at -5%) and a positive population (maximum frequency of the % inhibition at 95%). Based on these data, the prevalence of seropositive animals was 65% (95% confidence interval: 63%-67%). By exchanging plasma- and bulk milk samples between two laboratories (The Netherlands and Denmark), a good overall agreement was found between results obtained with the Ceditest and those obtained with the Danish blocking ELISA as used in the Danish BVDV eradication programme. The results indicate that BVDV infections can reliably be diagnosed by the Ceditest ELISA and that the test is suitable for use in large scale screening and eradication programmes.  相似文献   

6.
OBJECTIVES: To determine the prevalence of Salmonella infections in horses at necropsy. DESIGN: Cross-sectional prevalence survey. ANIMALS: 102 horses. PROCEDURE: Mesenteric lymph nodes were collected from horses that were necropsied. Horses had died or were euthanatized because of severe disease or at the request of the owner. Twenty-eight of the horses were racehorses euthantized following acute catastrophic injuries on the racetrack. Mesenteric lymph nodes were submitted for Salmonella culture via direct plating of tissue specimens on MacConkey agar and by use of 4 enrichment culture techniques that used tetrathionate and selenite enrichment broth and brilliant green and Salmonella-Shigella selective plating media. RESULTS: Salmonella typhimurium was isolated from the mesenteric lymph nodes of 2 foals (2/102, 1.96% of the horses). Salmonella organisms were not isolated from the mesenteric lymph nodes of adult horses. CONCLUSIONS AND CLINICAL RELEVANCE: Prevalence of Salmonella infections in horses of our study (1.96%) suggests that the results of cross-sectional surveys, using bacteriologic culture to determine prevalence of Salmonella infection, should be interpreted with caution. Prevalence of Salmonella infections determined in a single facility may not reflect the prevalence of Salmonella-infected horses in the general population; furthermore, obtaining a Salmonella isolate from a horse does not establish that the horse is a chronic Salmonella carrier.  相似文献   

7.
OBJECTIVE: To compare 3 alternative culture techniques for the detection of Salmonella organisms in swine feces with a modification of the International Standard Organization (ISO) 6579 standard protocol. SAMPLE POPULATION: Fecal samples from swine herds suspected of having Salmonella infections. PROCEDURE: 4 experiments were performed to evaluate the following: 1) diagnostic sensitivity of the selective preenrichment and rapid isolation novel technology (SPRINT) protocol, compared with that of the modified ISO protocol; 2) detection limit of the SPRINT protocol for Salmonella organisms; 3) use of tetrathionate-novobiocin (TTN) broth, compared with selenite cysteine (SC) broth for selective enrichment; and 4) use of universal preenrichment (UPE) broth, compared with buffered peptone water (BPW) for preenrichment of samples prior to the use of modified semisolid Rappaport-Vassiliadis (MSRV) plates. RESULTS: Comparing the Salmonella culture results of 183 swine fecal samples, the diagnostic sensitivity of the SPRINT protocol (0.86) was not significantly different than the diagnostic sensitivity of the modified ISO protocol (0.80), although it was 24 hours faster. The SPRINT protocol could detect 5 of the 6 investigated Salmonella serotypes at inoculation concentrations of < 10 colony-forming units (CFU)/25 g of uncontaminated feces. The TTN broth performed significantly better than the SC broth for selective enrichment of Salmonella organisms. There was no significant difference in results of preenrichment of samples between the use of UPE broth or BPW. CONCLUSIONS AND CLINICAL RELEVANCE: The SPRINT protocol may provide a faster alternative for isolation of Salmonella organisms from swine fecal samples. Furthermore, the use of TTN broth instead of SC broth may increase the sensitivity of the modified ISO 6579 protocol.  相似文献   

8.
In two studies, seven different culture protocols were compared to test naturally contaminated faecal samples from pigs for isolation of Y. enterocolitica serotype O:3/biotype 4 (n = 70 and n = 79). Four of the protocols were based on the Nordic Committee on Food Analysis (NMKL protocols), while three protocols were based on a rapid and selective method (here called ITC protocols). The protocols differed mainly in time of pre-enrichment (1, 10 and 24 d) and enrichment (2, 10, 24 d) and the type of selective enrichment media (ITC vs. MRB). The sensitivity of the rapid ITC protocol (24 % and 9 %) was comparable with the lengthy NMKL-protocols (16 % and 11 %), while the results of direct plating after 3 h (4 %) and the extended enrichment in ITC-broth (4 %) were very low. In addition, there was a marked reduction in the number of false positive plates in the short selective protocol (62 % vs. 12 %). The results indicate possibilities of shortening the culture methods by replacing most of the biochemical tests with an agglutination test based on a monoclonal antibody.  相似文献   

9.
A rapid and readily available DNA probe kit was developed for the detection of Salmonella spp. This kit utilized the colorimetric DNA/rRNA sandwich hybridization method in microtiter wells. Within 3 hr Salmonella spp. in selective enrichment broth cultures were detected by the DNA probe kit. The kit effectively identified all of 187 strains of Salmonella tested and yielded no false-positive reactions in the examination of 674 pure cultures of non-salmonellae. The DNA probe kit could detect 10(5) cfu/ml in pure culture. A total of 379 naturally contaminated samples (raw chicken meat, liquid egg, animal feeds, poultry feces and frozen foods) were tested, both by the standard culture method and the DNA probe kit. The 169 of these samples were culture positive and 210 were culture negative. The sensitivity of the DNA probe kit was 98.2% (166/169) and the specificity was 99.5% (209/210). These results show that the DNA probe kit is a useful tool to examine a large number of various samples for contamination by Salmonella spp. in food and livestock industry.  相似文献   

10.
Clinical specimens of small animals (n=869) were screened for the occurrence of methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA; MRSA) during routine microbiological examinations, and results were confirmed by a multiplex PCR strategy. The genetic relatedness of all mecA-positive S. aureus isolates was further investigated by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), PCR for Panton-Valentine leukocidine genes (PVL) and staphylococcal cassette chromosome mec-typing (SCCmec). A total of 61 S. aureus isolates were found during a 20-month period of investigation, 27 (44.3%) of them harbouring the mecA gene for methicillin-resistance. The majority of MRSA were isolated in specimens from dogs (n=18) and cats (n=4). One guinea pig and one rabbit were found to be positive for an MRSA infected site. Similarly, three exotic animals, a turtle, a bat and a parrot, were found to be infected with MRSA. PFGE and MLST analysis revealed a certain genotype ("A" and "A-1") dominating the isolate collection (23 of 27). Furthermore, one isolate showed homologous PFGE pattern to the German epidemic strain Barnim ("BE") and another one ("BE-1") was considered to be closely related. A third genotype ("B") was detected in two cases. Two different sequence types (ST) were identified among the 27 MRSA isolates. PFGE type "A" and both strains related to the Barnim epidemic strain were assigned to ST22, whereas ST239 was associated to PFGE profile "B". The present data show that certain MRSA genotypes are capable of infecting a wide spectrum of small and exotic animals, especially in clinical facilities.  相似文献   

11.
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12.
In two studies, seven different culture protocols were compared to test naturally contaminated faecal samples from pigs for isolation of Y. enterocolitica serotype O:3/biotype 4 (n = 70 and n = 79). Four of the protocols were based on the Nordic Committee on Food Analysis (NMKL, protocols), while three protocols were based on a rapid and selective method (here called ITC protocols). The protocols differed mainly in time of pre-enrichment (1, 10 and 24 d) and enrichment (2, 10, 24 d) and the type of selective enrichment media (ITC vs. MRB). The sensitivity of the rapid ITC protocol (24% and 9%) was comparable with the lengthy NMKL-protocols (16% and 11%), while the results of direct plating after 3 h (4%) and the extended enrichment in ITC-broth (4%) were very low. In addition, there was a marked reduction in the number of false positive plates in the short selective protocol (62% vs. 12%). The results indicate possibilities of shortening the culture methods by replacing most of the biochemical tests with an agglutination test based on a monoclonal antibody.  相似文献   

13.
The Directive 2003/99/EG of the European Parliament and of the Council on the monitoring of zoonoses and zoonotic agents demands a quality management (QM) system for the execution of its monitoring programmes. Consequently the National Salmonella Reference Laboratory of Germany performed two ring-trials in 2005 and 2006 on the microbiological detection of Salmonella from poultry feces among all participating laboratories in the Federal States. Salmonella detection was performed according to the EN ISO 6579:2002 standard method which was modified according to the recommendations of the Community Reference Laboratory for Salmonella in Bilthoven, The Netherlands. This method uses modified-semisolid Rappaport-Vassiliadis Agar as the only selective enrichment. In 2005 twenty-four and in 2006 twenty-two laboratories participated.They received eight identical samples of the contamination levels L0 (no Salmonella), L1 (11 and 16 cfu per 10 g faeces respectively) and L2 (292 and 418 cfu per 10 g faeces respectively). For both years the data of 20 laboratories could statistically be evaluated. The relative accuracy of the respected results increased from 88.8% in 2005 to 98% in 2006. This is as well reflected in the improved COR- and Kappa-Indices. Taken all together the data show, that the modified-semisolid Rappaport-Vassiliadis protocol is a sensitive, established method for the detection of Salmonella from poultry faeces.  相似文献   

14.
Genoa salami prepared using three different salt concentrations (2.0, 2.75 and 3.3%) were inoculated with 2.0 x 10(3) and 1.1 x 10(3) bacteria/g of Salmonella typhimurium and Staphylococcus aureus respectively. Over a period of 74 days samples were taken and analyzed for water activity and pH, counts of S. aureus and presence of Salmonella. After 11 days of dry-curing Salmonella could no longer be detected by preenrichment followed by selective enrichment procedures. Viable S. aureus were still found after 74 days of dry-curing. The results of this study would suggest that water activity and pH measurements are useful in evaluating the safety of dry-cured products.  相似文献   

15.
A conventional method of isolating Salmonella was compared with isolation using novobiocin-supplemented plating media and delayed secondary enrichment (DSE). The DSE greatly increased the ability to isolate Salmonella from poultry and environmental samples. Four hundred sixty-four isolations of Salmonella were made from a total of 4377 cultures (11%). Two hundred sixty-nine (58%) isolations of Salmonella were made following the 24-hour incubation; of these, 43 (9%) isolates were isolated only at this time. In comparison, a total of 421 (91%) Salmonella were isolated by DSE, of which 195 isolates (42%) were isolated only with DSE. The addition of novobiocin to the selective plating medium increased the isolation rate for Salmonella and reduced the level of contaminating bacteria growing on the plate.  相似文献   

16.
通过对各种增菌液和培养基的比较以及组合筛选,选择一种较为有效和简便的分离沙门菌的方法.采用6种常用的选择性培养基对9种血清型的沙门菌以及常见的共生肠道菌大肠杆菌和阴沟肠杆菌分别进行培养,根据生长特点对选择性培养基进行初步筛选,然后对3种常用选择性增菌液进行筛选,将筛选出的增菌液与培养基进行不同组合,检测各血清型沙门菌与大肠杆菌、阴沟肠杆菌的混合物在不同组合中的增菌和分离效果,并对其进行评价.研究结果表明,最佳分离培养方案为样品经SC和TTB增菌后再用显色培养基或者XLT4培养基进行选择性培养.本研究结果优化了沙门菌的常规分离培养方法,可用于不同样品中沙门菌的分离培养,提高沙门菌分离率.  相似文献   

17.
Measurements of morphological and biochemical parameters in subcutaneous adipose tissue as well as investigations of energy metabolism and fat deposition of 89 male castrated pigs were performed. Breeding lines of swine (German Landrace) had been selected through 8 generations for high ("E(+)-Line") and low ("E(-)-Line") levels of NADPH-generating dehydrogenases. A control group ("K.") without selection was closely paralleled. For 21 days the animals were kept under feeding experiments within 2 sectors of growing period (67 kg, 85 kg body mass), and biopsies of backfat were examined subsequently. The inner layer of subcutaneous adipose tissue showed constantly bigger fat cells than the outer layer. The fat cell size increased generally with fattening and body mass respectively. The cellularity of adipose tissue was dependent significantly on the percentage of the very small fat cells measured up to 30 microns diameter (= "PKF30"). The breeding lines differed slightly with respect to their cellularity: The inner layer showed the gradation E+ greater than K. greater than E- concerning fat cell volumes and fat cell surfaces respectively. The PKF30 correlated significantly with food energy level as well as with the respirationally examined protein retention, particularly in inner layers of younger animals. Relations to the fat deposition (examined respirationally or with the D2O-Method and after slaughter respectively) were recognized, not showing validity for all cases. The parameters of lipogenic activity tested by tissue slice preparations and homogenates respectively correlated negatively with average fat cell size.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

18.
Brief history and extensive published field efficacy data of the two rough ("R") bacterial mutants utilized in commercial preparations of the core antigen bacterins Escherichia coli O111:B4 (strain J5) and Salmonella typhimurium Re-17 are summarized. Particular dosage schedules and routes of administration of coliform mastitis bacterins are compared for their associated ecacy. Practical concerns in employing a coliform mastitis vaccination program are discussed. Characteristics of farms using coliform mastitis vaccination and suggested guidelines for whether individual dairy herds should adopt this practice are presented for consideration.  相似文献   

19.
Su YC  Yu CY  Lin JL  Lai JM  Chen SW  Tu PC  Chu C 《Avian diseases》2011,55(2):217-222
Salmonellosis is a common food-borne illness in humans caused by Salmonella-contaminated poultry and their products. In hatcheries, 110 Salmonella isolates were identified, mostly from first enrichment, and few from delayed enrichment. The Salmonella prevalence in goose and duck hatcheries was higher when measured by four multiplex PCR methods than by traditional culture (73.8% vs. 44.35%, P < 0.05); 97.3% of 110 isolates were Salmonella Potsdam of serogroup C1 and other isolates were Salmonella Montevideo of C1 and Salmonella Albany of C2. Plasmid and pulsed field gel electrophoresis genetic analysis revealed that isolates from duck hatcheries were more diverse than those from goose hatcheries. In Salmonella Potsdam, host species-specific genotypes were observed in geese for genotypes 3, 4, and 5 and in ducks for genotypes 7, 8, and 9, suggesting that Salmonella Potsdam may evolve into goose- and duck-specific isolates. An examination of 1121 eggs found that only Salmonella Potsdam was identified in 1.8% (7/591) of eggs from chickens fed on the ground, not housed in cages, and in egg content (6/7) as well as eggshell membrane (1/7). In conclusion, Salmonella Potsdam may be a major Salmonella infection in waterfowl and chicken eggs.  相似文献   

20.
The accuracy of bacterial culture and PCR for Salmonella in swine was examined through systematic review of existing primary research in this field. A replicable search was conducted in 10 electronic databases. All steps of the review were conducted by two reviewers: to identify relevant publications, to assess their methodological soundness and reporting, and to extract raw data or reported test accuracy estimates. Meta-analyses and meta-regression were performed: to evaluate pooled estimates of test sensitivity (Se) and specificity (Sp), to identify variables explaining the variation in reported test estimates, and to evaluate the association between these variables and reported test Se and Sp. Twenty-nine studies were included in the review. Unique test evaluations reported in these 29 studies were categorized according to the type of test comparison: culture versus culture (n = 134 test evaluations) and PCR versus culture (n = 21). We identified significant heterogeneity among evaluations for each test category. For culture, more heterogeneity was caused by differences in individual test protocols (52%) than overall differences between studies (16%). Enrichment temperature, study population, agar and enrichment type were significantly associated with variation in culture Se. Furthermore, interaction between enrichment temperature and enrichment type was detected. For PCR, most of the heterogeneity was caused by overall differences between studies (65-70%); sample type and study size were associated with variation in reported PCR Se and Sp. The overall methodological soundness and/or reporting of primary studies included in this review were poor, with variable use of reference standards, and consistent lack of the use or reporting of blinding, randomization and subject (sample) selection criteria. Consequently, the food safety and veterinary public health research community should formally consider ways for standardizing the conduct and reporting of this type of research.  相似文献   

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