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1.
Three slide agglutination tests for identification of Staphylococcus aureus were compared. The agglutination tests used for evaluation were Staphaurex (Wellcome Diagnostics), Staphyslide-Test (BioMerieux), and ANI S. aureus TEST (Ani Biotech Oy). A total of 347 isolates were analyzed, including 288 strains of S. aureus, 49 of S. epidermis, 11 of S. intermedius, 12 strains of other staphylococci and 14 non-staphylococcal strains. One hundred of the S. aureus strains were isolates from cases of food poisoning, 129 from mastitis and 59 from other clinical cases. The sensitivities of the tests were also compared using diluted suspensions of S. aureus strains and with purified Protein A dilutions. The results showed that the sensitivities of the tests were 98.6%, 97.9% and 99.0% for Staphaurex, Staphyslide-test and ANI S. aureus TEST, respectively. The specificities were 100% for the Staphyslide test and 98.8% for both the ANI S. aureus TEST and the Staphaurex test. The sensitivities measured with diluted S. aureus strain suspensions and Protein A solutions were equal with the Staphaurex and ANI S. aureus TEST. All the agglutination tests studied proved to be practical, easy to use and accurate for the rapid identification of S. aureus strains from culture isolates.  相似文献   

2.
A total number of 640 staphylococci isolated from cows' milk were tested by latex agglutination and coagulase tests. About 50% of coagulase positive and 5% of coagulase negative staphylococci were positive to the latex agglutination tests. Latex agglutination tests were found to be not satisfactory for determining the coagulase status of staphylococci isolated from cows' milk.  相似文献   

3.
A comparison was made between conventional tube coagulase, macrocupsular coagulase, latex agglutination, and miniaturized biochemical test systems for identification of Staphylococcus aureus of bovine origin. A total of 303 gram-positive, catalase-positive cocci of bovine origin were tested. Agreement between each pair of 4-hour tube coagulase, macrocupsular coagulase, latex agglutination, and miniaturized biochemical test results within isolates was greater than 95.0. Seventeen (5.6%) isolates were test negative for 4-hour tube coagulase, but test positive for 24-hour tube coagulase. Thirteen (76.5%) of these isolates were identified as S hyicus, 3 were S aureus, and 1 was not identified.  相似文献   

4.
OBJECTIVE: To estimate sensitivity and specificity of 4 commonly used brucellosis screening tests in cattle and domestic water buffalo of Trinidad, and to compare test parameter estimates between cattle and water buffalo. ANIMALS: 391 cattle and 381 water buffalo. PROCEDURE: 4 Brucella-infected herds (2 cattle and 2 water buffalo) and 4 herds (2 of each species) considered to be brucellosis-free were selected. A minimum of 100 animals, or all animals > 1 year of age, were tested from each herd. Serum samples were evaluated for Brucella-specific antibodies by use of standard plate agglutination test (SPAT), card test (CT), buffered plate agglutination test (BPAT), and standard tube agglutination test (STAT). A Bayesian approach was used to estimate sensitivity and specificity of diagnostic tests without the use of a gold standard, assuming conditional independence of tests. RESULTS: Sensitivity and specificity estimates in cattle, respectively, were SPAT, 66.7 and 98.9; CT, 72.7 and 99.6; BPAT, 88.1 and 98.1; and STAT, 80.2 and 99.3. Corresponding test estimates in water buffalo, respectively, were SPAT, 51.4 and 99.3; CT, 90.4 and 99.4; BPAT, 96.3 and 90.7; and STAT, 75.0 and 98.8. Sensitivity of the CT and specificity of the BPAT were different between cattle and water buffalo with at least 95% probability. CONCLUSIONS AND CLINICAL RELEVANCE: Brucellosis serologic test performance varied by species tested, but BPAT had the highest sensitivity for screening cattle and water buffalo. Sensitivity and specificity of more than 2 screening tests can be estimated simultaneously without a gold standard by use of Bayesian techniques.  相似文献   

5.
Prevalence of udder infections and mastitis in 50 California dairy herds   总被引：2，自引：0，他引：2  
The California mastitis test (CMT) and bacteriologic culture were performed on samples of bulk-tank milk and cow-composite milk (n = 23,138 cows) from 50 California dairies, 19 of the 50 with known mastitis problems. Thirty-eight (76.0%) bulk-tank milk samples and 12,334 (53.3%) cows were positive by results of the CMT. Potential mastitis agents were isolated from 5,085 (22%) cows. Staphylococcus aureus was isolated from all 50 herds, Streptococcus agalactiae was isolated from 47 herds, and Mycoplasma sp was isolated from 24 herds. For cow-composite milk samples, the prevalences were 9.3% for Str agalactiae, 9.1% for S aureus, 0.9% for Mycoplasma sp, 1.2% for coliform bacteria, 0.9% for other streptococci, 0.8% for coagulase-negative staphylococci, and 1.3% for other organisms. The relative sensitivity and the relative specificity of the CMT performed on cow-composite milk samples were 83.4% and 55.2%, respectively, and the predictive value of positive CMT results was 34.2%.  相似文献   

6.
In this study, bacterial cultures were collected from five sites on each of 50 healthy cats and 48 cats with inflammatory skin disease (ISD), to determine prevalence of carriage and relative frequency of methicillin resistance in coagulase-positive staphylococci and Staphylococcus schleiferi ssp. schleiferi. Latex agglutination testing for penicillin-binding protein 2a (PBP2a) and pulsed field gel electrophoresis (PFGE) were performed on all methicillin-resistant (MR) isolates. Polymerase chain reaction (PCR) for the mecA gene was performed on MR S. intermedius and S. schleiferi isolates. Staphylococcal chromosomal cassette (SCCmec) typing was performed on all MR S. aureus isolates. Coagulase-positive staphylococci and S. schleiferi ssp. schleiferi were isolated from 24 of 48 cats with ISD: Staphylococcus aureus (14 of 24, 58%), Staphylococcus intermedius (11 of 24, 46%), Staphylococcus schleiferi ssp. schleiferi (1 of 24, 4%), and Staphylococcus hyicus (1 of 24, 4%). Prevalence of MR was 7% for S. aureus, 0% for S. intermedius, 100% for S. schleiferi ssp. schleiferi, and 0% for S. hyicus. Coagulase-positive staphylococci were isolated from 17 of 50 healthy cats: S. aureus (10 of 17, 59%), S. intermedius (11 of 17, 65%), and S. schleiferi ssp. coagulans (1 of 17, 6%). Prevalence of MR was 20% for S. aureus, 18% for S. intermedius, and 0% for S. schleiferi ssp. coagulans. All MR isolates were positive for PBP2a via latex agglutination. Methicillin-resistant S. intermedius and S. schleiferi ssp. schleiferi isolates were also positive for the mecA gene via PCR. Methicillin-resistant S. aureus isolates were identified as SCCmec type II. Results of PFGE indicated heterogeneity among isolates. There was no significant difference in staphylococcal isolation or methicillin resistance between study groups. While present, MR coagulase-positive staphylococci are significantly less common in these study populations.  相似文献   

7.
Three rapid agglutination assays for the identification of Staphylococcus aureus Monostaph (Bionor A/S, Skien, Norway), Staphyslide-Test (BioMerieux, Lyon, France) and Staph-Rapid-Test (Roche, Basel, Switzerland), were compared. A total of 104 Gram-positive, catalase positive cocci were tested: Nineteen Staphylococcus reference strains comprising 15 spp. (4 strains were coagulase positive), and 7 Micrococcus reference strains comprising 4 spp.; 22 food isolates comprising 13 S. aureus, 8 coagulase positive Staphylococcus spp., and 1 Micrococcus sp.; 56 animal isolates comprising 11 S. aureus, 9 S. hyicus subsp. hyicus, 2 S. intermedius, 15 coagulase positive and 19 coagulase negative Staphylococcus spp. Totally 54 strains were coagulase positive. Considering agglutination of a coagulase positive strain as a correct identification, Monostaph, Staph-Rapid-Test, and Staphyslide-Test correctly identified 52 (96.3%), 47 (87.0%) and 48 (89.0%) of the coagulase positive staphylococci, respectively. Monostaph, Staph-Rapid-Test and Staphyslide-Test showed 1 (2.0%), 4 (8.0%) and 4 (8.0%) false positive reactions respectively. Monostaph, Staph-Rapid-Test and Staphyslide-Test gave 0 (0.0%), 6 (5.8%) and 7 (6.7%) non-interpretable reactions, respectively. Monostaph may be a good alternative to the tube-coagulase test for rapid and reliable identification of coagulase positive staphylococci from both food and veterinary sources. However, false negative reactions may occur with coagulase positive strains of S. hyicus subsp. hyicus and S. intermedius.  相似文献   

8.
Brucella spp. are Gram-negative, facultative, intracellular coccobacilli that are pathogenic to a variety of mammals, including ruminants and humans. The conventional serological test for diagnosing brucellosis in cattle in Korea is the standard tube agglutination test. However, agglutination tests sometimes give false-positive results due to cross-reactions with other pathogens. The outer membrane proteins of Brucella species have been extensively studied for their immunogenicity and serodiagnostic applications. However, an application of B. abortus OMPs for serodiagnosis has not been successfully established. In this study, cloning and expression of B. abortus Omp28, a group 3 antigen, were accomplished by PCR amplification cloning into a pMAL expression system, and purification of a recombinant Omp28 (rOmp28). The immunogenicity of rOmp28 was confirmed by Western blot analysis with Brucella-positive bovine serum. To determine whether rOmp2 has a potential benefit for use in the serodiagnosis of bovine brucellosis, rOmp28-based ELISA and latex bead agglutination test were performed. B. abortus positive (n=122) or negative (n=88) from TAT were positive (118/122, 96.7%) or negative (84/88, 95.4%) in ELISA and were positive (94/122, 77%) or negative (71/88, 81.7%) in that the latex bead agglutination test, respectively. The sensitivity, specificity and accuracy were 96.7, 95.4, 96.2% in ELISA and 77, 80.6, 78.5% in latex bead agglutination test, respectively. These findings suggest that the rOmp28 of B. abortus might be a good candidate for developing serological diagnostic tools for bovine brucellosis.  相似文献   

9.
Methicillin resistance rates of 41% for Staphylococcus aureus, 16% for S. intermedius, and 40% for S. schleiferi have recently been reported in canine patients. These were deemed to be reflective of referral and clinician-selection biases, which would imply significantly lower methicillin-resistant staphylococcal carriage rates in less-biased canine populations. In this study, swabs for bacterial culture were collected from five cutaneous sites on each of 50 healthy dogs and 59 dogs with inflammatory skin disease to determine prevalence of carriage and relative frequency of methicillin resistance in coagulase-positive staphylococci and S. schleiferi ssp. schleiferi. These were identified morphologically and by Gram's staining, catalase and coagulase testing, and biochemical speciation. Coagulase-positive staphylococci and S. schleiferi ssp. schleiferi were isolated from 88% (52 of 59) of affected dogs. Species identified in the culture-positive dogs were: S. aureus in 12%, S. intermedius (92%), S. schleiferi ssp. schleiferi (10%), and S. schleiferi ssp. coagulans (10%) with methicillin resistance rates of 17%, 8%, 20% and 20%, respectively. Coagulase-positive staphylococci were isolated from 74% (37 of 50) of healthy dogs: S. aureus (16%), S. intermedius (92%) and S. schleiferi ssp. coagulans (5%). Methicillin resistance rates were 0%, 3% and 50%, respectively. Of total methicillin-resistant isolates, 11 of 13 were positive for PBP2a via latex agglutination. Methicillin-resistant S. intermedius and S. schleiferi ssp. schleiferi isolates were all positive for the mecA gene via PCR. There was no significant difference in staphylococcal isolation or methicillin resistance between study groups. While present, methicillin-resistant coagulase-positive staphylococci are significantly less common in these less-biased populations than in the clinical isolates previously reported from this institution which provided the impetus for this study.  相似文献   

10.
A commercial latex agglutination test for the detection of Group B streptococcal antigens was used to detect infection due to Streptococcus agalactiae in whey of bovine milk samples. Fifteen out of 17 known infections were detected, but it was necessary to incubate the wheys at 37 degrees C for 18 hours in nine of the samples. It was found that the latex agglutination test could detect Group streptococcal carbohydrate antigens in whey samples from artificially infected quarters from one to four days after failure to detect the organism on culture or after antibiotic therapy of the affected quarter.  相似文献   

11.
A total of 144 strains of mastitis streptococci (groups B, C, and D) were grouped by conventional technique (Lancefield precipitin test) latex agglutination (LA), and coagglutination (CA). The LA correctly grouped 98% and the CA grouped 100% of strains on the test when the instructions of the manufacturers were followed. Sensitivity of both tests was improved for strains belonging to group D when extracts from colonies grown on sheep blood agar plates were used for grouping. Nonspecific reactions between groups C and B were observed only with one kit of LA reagents, whereas cross-reactions were recorded with all groups when CA reagents were used.  相似文献   

12.
Background: Fibrin(ogen) degradation products (FDPs) and D‐dimer are sensitive indicators of excessive fibrinolysis due to disseminated intravascular coagulation (DIC) in dogs. To the authors' knowledge, latex‐agglutination–based plasma FDP and D‐dimer assays have not been validated for use in horses. Objectives: To determine: 1) sensitivity and specificity of latex‐agglutination serum and plasma FDP and D‐dimer assays for diagnosis of DIC; and 2) their prognostic value in horses with severe colic. Methods: At hospital admission and 24 hours later, blood was collected from 30 healthy horses and 20 horses with severe colic. Horses fulfilling predefined laboratory criteria of DIC were enrolled, and their data were subcategorized by survival for analysis. Platelet counts were determined and coagulation panel testing was performed. Serum and plasma FDP concentrations were measured using separate latex agglutination kits. Plasma D‐dimer concentration was measured using 3 latex agglutination kits and a card immunofiltration test. Test sensitivity and specificity results were determined for healthy horses and those with colic. Median test values were compared between colic survivors and nonsurvivors to evaluate the prognostic usefulness of all tests. Results: Performance characteristics varied among assays and kit suppliers. The FDP assays had low sensitivity (<40%), whereas the most accurate D‐dimer kit had 50% sensitivity and 97% specificity. High D‐dimer concentration was the third most common hemostatic abnormality in horses with colic. Median antithrombin (AT) activity was significantly lower and activated partial thromboplastin time (aPTT) was significantly longer in nonsurvivors than survivors. Conclusions: Commercial latex‐agglutination D‐dimer assays might prove useful as adjunctive tests for the diagnosis of DIC in horses with severe colic; however FDP assays are invalid for this purpose. Low AT activity and prolonged aPTT at admission are associated with a poor prognosis in this patient population.  相似文献   

13.
多重PCR快速检测奶牛乳房炎3种主要病原体   总被引：10，自引：0，他引：10  
奶牛乳房炎是引起奶牛业经济损失的一种重要疫病,目前还没有快速、特异检测奶牛乳房炎主要致病原的方法。本试验根据金黄色葡萄球菌、无乳链球菌、大肠杆菌各自保守的16S或23S rRNA基因序列,合成了3对特异性引物,建立了三重PCR检测方法。特异性试验表明,该方法对所有参与测试的金黄色葡萄球菌、无乳链球菌和大肠杆菌都能扩增出各自的阳性条带,而对所有参与测试的对照菌株则不能扩增出任何条带。敏感性试验表明该方法能检测到4个菌的金黄色葡萄球菌、无乳链球菌和2个菌的大肠杆菌。对送检的乳房炎奶样36份直接进行PCR检测,金黄色葡萄球菌阳性7份,无乳链球菌阳性2份,大肠杆菌阳性6份。  相似文献   

14.
The dsRNA concentrated polyacrylamide gel electrophoresis (CPAGE) detected rotavirus directly from 19% of 77 stool specimens from diarrheic calves. A commercial enzyme-linked immunosorbent assay (ELISA) detected 25%, latex agglutination test, 23%, and polyacrylamide gel electrophoresis (PAGE), 19%. Establishing CPAGE as the "standard," the commercial ELISA and the latex agglutination test both had higher sensitivity (84%) than PAGE (79%). However, PAGE produced the highest specificity (100%), followed by agglutination (88%) and ELISA (84%). The commercial ELISA had a slightly higher sensitivity than agglutination, PAGE, and CPAGE, but the ELISA specificity was generally lower. The latex agglutination test had a lower sensitivity than ELISA, but specificity was higher. Agglutination had similar negative predictive values (94%), compared with agglutination and PAGe, but had the lowest positive predictive value (a measure of accuracy) (70%). Agreement with CPAGE was highest for PAGE (94.8%), followed by agglutination (87%) and ELISA (84.4%). The calculated percentages of total disagreement with all other tests indicated that ELISA differed from the other rotavirus detection assays in 10.4% of the cases, agglutination in 7.8%, PAGE in 2.6%, and CPAGE in 1.3%. The 2 PAGE assays allowed the detection of atypical rotaviruses from feces based on the characteristic "super-short" migration pattern of the 11 genomic segments of rotaviruses and of other members of the Reoviridae.  相似文献   

15.
The aim of this paper was to evaluate the effects associated with intramammary infection (IMI) by a bacterium or a group of bacteria (Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, coliforms, Staphylococci other than S. aureus, and Corynebacterium bovis) on the somatic cell count (SCC) in quarter milk of dairy cows. Papers selected for analysis had to provide SCC values associated with the natural infection in quarters by different bacteria. Sampling for measurement of SCC and determination of the infection had to be done on the same day. Only papers published in English or in French after 1971 were considered. Twenty-one papers fulfilled the selection criteria. The animals sampled, the measurement techniques for SCC and the bacteriological identification, as well as the definition of the infection, all differed widely among the selected studies. The meta-analysis method was used to estimate both the mean SCC (arithmetic and geometric) value and the average increase on SCC of each type of infection. The geometric mean SCC in bacteriologically negative quarters was 68 000 c/mL. In case of IMI, the retained SCC was 357 000, 857 000, 547 000, 1 024 000, 1 151 000, 138 000 and 105 000 c/mL in quarters infected by Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, coliforms, staphylococci other than S. aureus and Corynebacterium bovis, respectively. The variation factors that could influence these SCC values and the bacteriological results are discussed.  相似文献   

16.
Three hundred fifty one (195 local zebu and 156 Holstein x local zebu crosses) lactating cows of smallholder farms in Bahir Dar 'milk shed' were examined from September 2003 to March 2004 to determine mastitis prevalence, isolate pathogens and identify the role of some potential risk factors. Clinical prevalence was determined through examination of abnormalities of milk, udder or cow. California mastitis test (CMT) was used for determination of subclinical mastitis prevalence. Clinical prevalence at cow level was 3.9% in crossbreds and none in local zebu breeds. Subclinical mastitis at cow level based on CMT was high (34.4%) in crossbreds compared to indigenous zebu (17.9%) (p < 0.05). Quarter subclinical prevalence based on CMT was 17.9% and 4.9% in crossbreds and local zebu, respectively. The pathogens isolated from mastitic milk (CMT positive milk) were coagulase negative staphylococci (CNS), S. aureus, Str. agalactiae, Str. dysgalactiae, Str. uberis, Micrococcus species, C. bovis, A. pyogens, B. cereus, and S. intermedius. Among these, the most frequent isolates were CNS (50%), S. aureus (19%), Str. agalactiae (8%) and Str. dysgalactiae (7%). Among potential risk factors considered, stage of lactation, parity and breed were found to affect the occurrence of mastitis significantly (p < 0.05).  相似文献   

17.
OBJECTIVE: To determine the methicillin-resistant profile of staphylococcal isolates from the skin of dogs with pyoderma. ANIMALS: 90 dogs with pyoderma. PROCEDURE: Staphylococci isolated from dogs with pyoderma were tested for susceptibility to methicillin by use of a standard disk diffusion test with oxacillin disks. The DNA extracted from the isolates was tested for the mecA gene that encodes the penicillin-binding protein 2a (PBP2a) by use of a polymerase chain reaction (PCR) assay. The expression of PBP2a was determined with a commercial latex agglutination assay. Species of staphylococcal isolates were identified by use of morphologic, biochemical, and enzymatic tests. RESULTS: Most of the isolated staphylococci were methicillin-susceptible, coagulase-positive Staphylococcus intermedius isolates. Whereas only 2 of 57 S. intermedius isolates were resistant to methicillin, approximately half of the isolates had the mecA gene and produced PBP2a. Staphylococcus schleiferi was the second most common isolate. Widespread resistance to methicillin was found among S. schleiferi isolates. More coagulase-negative S. schleiferi isolates were identified with mecA gene-mediated resistance to methicillin, compared with coagulase-positive S. schleiferi isolates. CONCLUSIONS AND CLINICAL RELEVANCE: The latex agglutination assay for the detection of PBP2a expression coupled with the PCR assay for the mecA gene may provide new information about emerging antimicrobial resistance among staphylococcal isolates.  相似文献   

18.
The efficacy of a recombinant leptospiral outer membrane protein LipL41 as an antigen for conducting IgG-Enzyme linked immunosorbent assay (ELISA) and latex agglutination test (LAT) for serodiagnosis of bovine leptospirosis was evaluated. The recombinant LipL41 antigen developed and used for detecting the antibodies was specific in detection of the pathogenic serovars of Leptospira, as the expression of the LipL41 antigen is restricted only to pathogenic leptospires. A total of 430 bovine serum samples were subjected to IgG-ELISA and LAT, and the sensitivity and specificity were assessed in comparison with microscopic agglutination test (MAT). The sensitivity and specificity of IgG-ELISA and LAT were 86.84% and 93.16%, and 95.42% and 98.33% respectively. Both the tests are found to be sensitive, specific and concurred with the standard MAT. The study concluded that the rLipL41 protein could be used as a potential diagnostic antigen in different assay formats for bovine leptospirosis.  相似文献   

19.
Swab specimens obtained from skin lesions of 45 cats were cultured bacteriologically for staphylococci. Thirty-two staphylococcal isolates were recovered from 30 cats and were biotyped, using biochemical tests contained in a staphylococcal identification system. Of 23 isolates considered coagulase-positive, 16 were identified as Staphylococcus aureus, 5 as S intermedius, and 2 as S hyicus. Of 9 isolates considered coagulase-negative, 6 were identified as S simulans, 2 as S epidermidis, and 1 as S xylosus. Antimicrobial susceptibility tests were done on all staphylococcal isolates, using a disk-diffusion method. Staphylococcal isolates were susceptible to clavulanic acid-amoxicillin, cloxacillin, cephalothin, chloramphenicol, gentamicin, erythromycin, and trimethoprim-sulfamethoxazole. Resistance to penicillin G, ampicillin, and tetracycline was frequent.  相似文献   

20.
A latex agglutination test was evaluated as a method for the detection and titration of antibodies against swine Haemophilus infection and it was found that the test is applicable to the etiologic diagnosis of Haemophilus infection in swine. In swine infected experimentally with H. pleuropneumoniae (H. parahaemolyticus), the micromethod of agglutination using latex particles coated with antigens of H. pleuropneumoniae was found to be comparable agar-gel immunodiffusion and complement-fixation tests, which have previously been used for the etiologic diagnosis of the disease. Antibody titers determined by the latex agglutination test corrlated well with those determined by the other serological tests. The latex agglutination test tended to detect antibodies earlier than any of the other tests. By the latex agglutination test, weak cross-reactions were observed among different serotypes of H. pleuropneumoniae, whereas no cross-reaction was demonstrated between H, pleurophneumoniae and H. parasuis. The latex agglutination test was found to be simple and useful for the serological survey of swine Haemophilus infection, especially when dealing with a large number of samples.  相似文献   

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