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1.
Comparison of media used for the primary isolation of Mycobacteriurm bovis by veterinary and medical diagnostic laboratories 总被引：1，自引：0，他引：1
Veterinary and medical laboratories engaged in the cultural diagnosis of bovine or human tuberculosis were requested to supply samples of the media that they routinely use for the primary isolation of M. bovis. Fourteen laboratories supplied 7 basic media types; these were Lowenstein-Jensen, Stonebrink's, modified Middlebrook 7H11 agar, tuberculosis bovine blood agar, egg yolk agar, Gerloff's egg and Herrold's egg yolk. Two strains of M. bovis were used to test the media, strain AN5, a glycerol-tolerant laboratory strain and M86/90 a glycerol-sensitive wildtype strain. AN5 grew well on all media with the exception of Herrold's and strain M86/90 did not grow on media containing glycerol and grew poorly on Herrold's medium. It is recommended that Lowenstein-Jensen with pyruvate (but without glycerol), Stonebrink's, modified Middlebrook 7H11 and tuberculosis bovine blood agar should be considered the media of choice for the primary isolation of M. bovis. Egg yolk agar also proved adequate for this purpose in the trial. This medium may be suitable for routine use but to date experience with its use is limited. 相似文献
2.
Absence of encapsulation in strains of Staphylococcus aureus isolated from bovine mastitis 总被引：8，自引：0，他引：8
J C Anderson 《Research in veterinary science》1984,37(3):359-361
Thirty of 104 strains of Staphylococcus aureus isolated from clinical cases of bovine mastitis in England grew as diffuse colonies in serum soft agar (SSA), 45 grew as mixed diffuse and compact colonies and 29 yielded compact colonies only. The compact strains grew as diffuse colonies in SSA after one passage in the mammary gland of mice. However, none of the strains had an unstained halo when examined by the India ink technique and there was a 99.99 per cent reduction in the viable numbers of the bacteria in 30 representative strains 24 hours after inoculation into the peritoneal cavity of mice. By contrast the truly encapsulated strain M had an unstained halo by the India ink technique and resisted phagocytic killing in the peritoneal cavity. It is concluded that these strains from cases of mastitis are not encapsulated and that growth as diffuse colonies in SSA is not a reliable test of encapsulation. 相似文献
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4.
Incorporation of vancomycin (5 micrograms/ml), neomycin (5 micrograms/ml), sodium azide (50 micrograms/ml), nystatin (100 iu/ml) and cyclohexamide (100 micrograms/ml) into 5 per cent horse blood agar results in a selective medium for the primary isolation of Haemophilus somnus from cattle and sheep. Addition of thiamine monophosphate (1 microgram/ml) to the medium enhanced growth of this bacterium. Gram-positive bacteria did not grow on the medium and colonies of many Gram-negative bacteria were eliminated or reduced in numbers and size. Colonies of H somnus were larger on the selective medium than on sheep blood agar but retained typical morphology. Recovery of 18 laboratory strains was 73 to 166 per cent (mean 112) on selective medium compared to sheep blood agar. H somnus was isolated from the vagina of a total of 136 (28.6 per cent) of 476 cows surveyed, 79 (16.6 per cent) on sheep blood agar and 129 (27.1 per cent) on selective medium. The selective agents and thiamine were stable indefinitely as a freeze dried mixture while prepared plates were stable for two weeks. 相似文献
5.
Thirteen strains of Leptospira serotype hardjo were cultured from 200 bovine kidneys collected from an abattoir. All strains grew on primary isolation in EMJH medium 0.1 per cent Noble agar but most failed to grow in a variety of media containing neomycin or 5-fluorouracil as selective agents. Two of the cattle from which hardjo were isolated were seronegative by the microscopic agglutination test against hardjo, two had titres of 1/100, five of 1/400, three of 1/1600 and one of 1/6400. 相似文献
6.
The type strain WVU 1853 and field strains SG, N26 and A642 of Mycoplasma synoviae were examined for their requirement for nicotinamide-adenine dinucleotide (NAD) for in vitro growth. All the strains grew and could be repeatedly passaged in Frey broth medium supplemented with filter-sterilised NAD. In modified Frey broth medium from which NAD was omitted and broth medium for which the supplements including yeast extract and NAD were autoclaved, only strains N26 and A642 could be grown and passaged. The growth curves of strain N26 determined in broth media with and without NAD were similar. These results indicated that there are differences in NAD-requirement for in vitro growth among strains of M synoviae. 相似文献
7.
Nine strains of mycoplasmas were isolated from the lungs of 5 pigs with clinical signs of naturally acquired enzootic pneumonia. Mycoplasma hyopneumoniae was isolated from the lungs of 1 pig and M. hyorhinis from the lungs of 4. An unidentified mycoplasma, which utilized arginine, grew rapidly in broth culture and produced centred colonies on solid medium, was isolated from the lungs of 4 pigs. The pathogenicity of the isolated strain of M. hyopneumoniae was determined by inoculation of pigs from an enzootic pneumonia-free herd. Enzootic pneumonia was produced in the lungs of all 5 pigs inoculated intranasally and intratracheally with broth cultures of the organism isolatied by limit dilution techniques. Enzootic pneumonia was produced in 3 of 6 pigs inoculated intranasally and intratracheally with M. hyopneumoniae purified by the passage of colonies on agar blocks. M. hyopneumoniae was isolated in pure culture from the lungs of all pigs with induced pneumonic lesions. 相似文献
8.
Three gut lactobacilli from piglets (Lactobacillus plantarum L 5, Lactobacillus paracasei L 81, Lactobacillus fermentum L 670) and Lactobacillus casei subsp. pseudoplantarum L.c.) from a calf were examined by microtitre plate binding assay for their lectin-like binding activity after their cultivation on Rogosa agar and in MRS broth. Three ECM (extracellular matrix) molecules (fetuin, porcine fibronectin and porcine mucin) were selected for this assay. Additionally, the effect of heparin on the binding of these three ECM molecules by Lactobacillus strains in microtitre plates was tested. Moreover, haemagglutination tests with pig, cattle, sheep, and hen erythrocytes were performed. However, none of the four Lactobacillus strains examined did react with any of the erythrocytes tested. The differences between individual strains were observed in their binding to immobilised ECM molecules. The best adherent was the Lactobacillus plantarum L5, however, the other three strains showed also good ECM binding. With regard to an influence of cultivation medium on lectin-like binding activity, binding of all ECM molecules was expressed in Lactobacillus paracasei L 81 to significantly higher degree (P < 0.001) after cultivation on Rogosa agar than in MRS broth. Similarly, strains Lactobacillus fermentum L 670 and Lactobacillus casei subsp. pseudoplantarum L.c. displayed significantly higher (P < 0.001) binding of fibronectin and mucin after growth on Rogosa agar in comparison with MRS broth cultivation. However, no significant (on fetuin and fibronectin binding) or opposite effect (on mucin binding) of cultivation medium was observed in Lactobacillus plantarum L 5 strain. The influence of cultivation medium on fetuin binding by Lactobacillus fermentum L 670 was also not significant while Lactobacillus casei subsp. pseudoplantarum L.c. bound fetuin significantly better (P < 0.01) after growth on Rogosa agar. Heparin pretreatment increased the binding of the ECM molecules by the Lactobacillus fermentum L 670 strain significantly (P < 0.001 or P < 0.05) with the exception of porcine fibronectin when the strain was cultivated in MRS broth. This result is important especially in the connection with the previous observations that heparin decreased ECM binding of enteropathogens as staphylococci or clinical enterococcal isolates. Following up on some earlier strain characteristics, these results indicate that the selected lactobacilli are probably suitable for probiotic purposes. 相似文献
9.
S K Tiong 《The Veterinary record》1990,127(3):64-66
Two hundred and sixty-three cases of clinically diseased ducks of all ages were examined for the presence of mycoplasmas. Mycoplasmas and acholeplasmas belonging to more than eight serogroups were cultured from 68 of them, and comprised 12 M anatis, one M columbinasale, two M gallinaceum, two M gallinarum, nine M synoviae, three unidentified Mycoplasma species, 37 Acholeplasma laidlawii and one unclassified acholeplasma belonging to each of serogroups 7 and 8. They were identified by biochemical characterisation, disc growth inhibition and agar gel diffusion tests. Fifty-three (78 per cent) of the isolates occurred with species of Pasteurella: 33.8 per cent with Pasteurella anatipestifer, 32.4 per cent with P multocida and 11.8 per cent with both P anatipestifer and P multocida. Nine of the isolates (13.2 per cent) were in pure culture and six (8.8 per cent) with other agents. Of the ducks negative for mycoplasmas 33.3 per cent were infected with P anatipestifer, 25.1 per cent with P multocida and 14.4 per cent with both P anatipestifer and P multocida. There was no correlation between the infections with mycoplasmas and P anatipestifer but there was a weak association between the infections with mycoplasmas, especially M anatis and P multocida. 相似文献
10.
Development of improved methods for the transport and isolation of Haemophilus somnus 总被引：4，自引：0，他引：4
The survival of several strains of Haemophilus somnus under various simulated transport conditions was investigated. Recovery of H somnus from alginate swabs kept at room temperature was possible for up to 27 hours after sampling, but this period could be extended to 72 hours if the swabs were refrigerated. Storage of swabs in transport media did not prolong survival time significantly but did increase the number of bacterial contaminants, thus making recovery of H somnus less likely. The sensitivity of several strains of H somnus to a number of dyes, antibiotics and other antimicrobial agents was determined and a selective isolation medium then formulated. This medium which consisted of brain heart infusion agar supplemented with 5 per cent ovine blood, 5 per cent equine serum, 0.5 per cent yeast extract, cycloheximide (100 micrograms ml-1) and lincomycin (3 micrograms ml-1), facilitated the isolation of H somnus from contaminated material. However, while this medium was effective against many contaminants, it did not prevent swarming by Proteus species. 相似文献
11.
Contrary to historical evidence, recent biochemical and serological studies have suggested that the 1805 strain of M. iowae (K component of serovar I,J,K,N, Q,R) and the SA strain of M. gallopavonis (serovar F) were members of the species M. gallinaceum. After examining three seeds of strain 1805 and an original seed of the SA strain, we present evidence to indicate that 1805 and SA are indeed valid members of the species M. iowae and M. gallopavonis, respectively. However, some seeds of strains 1805 and SA may contain M. gallinaceum. In the case of strain 1805, it is possible that the original seed may have contained M. gallinaceum. 相似文献
12.
All the strains of Ornithobacterium rhinotracheale isolated in the Netherlands between 1996 and 1999 were tested in the agar gel diffusion test for their sensitivity to amoxycillin, tetracycline, enrofloxacin and trimethoprim/sulphonamide (TMP/S). The percentages of strains sensitive to amoxycillin and tetracycline decreased in successive years from approximately 62 per cent to 14 per cent, and four strains were resistant to enrofloxacin or TMP/S. Twelve multiresistant strains were tested against seven alternative antibiotics; they were resistant to all of them except clavulanic acid-potentiated amoxycillin. 相似文献
13.
K R Rhoades 《Avian diseases》1984,28(3):710-717
Comparison of biochemical test results and protein electrophoretic patterns of 21 strains of Mycoplasma iowae indicated that all were similar. Comparison of agglutination test results indicated marked within-species antigenic variation. None of 21 antigens prepared from different strains were effective in demonstrating turkey antibody against five reference strains. Examination of sera from turkeys exposed by intra-air-sac inoculation to two pathogenic strains also indicated antigenic variation. Neither the M. iowae type-strain, Iowa 695, nor the other reference strains were effective in demonstrating antibody against both strains used to expose the turkeys. These findings suggest that antigenic variation may be a major problem in effective serodiagnosis of M. iowae infections. 相似文献
14.
Pathogenicity of some Mycoplasma and Acholeplasma species in the lungs of gnotobiotic calves 总被引：3，自引：0，他引：3
Cloned cultures of 16 strains, representing nine different species of Mycoplasma and Acholeplasma, were inoculated intratracheally into gnotobiotic calves. Strains of M bovirhinis, M canadense, M verecundum, A axanthum and A modicum did not produce visible pneumonic lesions and were not reisolated from the lungs. Strains of M alkalescens and M arginini colonised the lower respiratory tract but failed to produce visible pneumonia. M bovigenitalium (strain M991/70) and M dispar (strain Gri226) both colonised the respiratory tract and induced pneumonic lesions estimated to involve up to 8 per cent (M bovigenitalium) and 17 per cent (M dispar) of the lung. Histologically M bovigenitalium produced a cuffing pneumonia and M dispar produced a interstitial alveolitis. 相似文献
15.
The in vitro emergence of resistance to enrofloxacin, erythromycin, tylosin, tiamulin, and oxytetracycline in three avian Mycoplasma species, Mycoplasma gallisepticum, Mycoplasma synoviae and Mycoplasma iowae was studied. Mutants were selected stepwise and their MICs were determined after 10 passages in subinhibitory concentrations of antibiotic. High-level resistance to erythromycin and tylosin developed within 2-6 passages in the three Mycoplasma species. Resistance to enrofloxacin developed more gradually. No resistance to tiamulin or oxytetracycline could be evidenced in M. gallisepticum or M. synoviae after 10 passages whereas, resistant mutants were obtained with M. iowae. Cross-sensitivity tests performed on mutants demonstrated that mycoplasmas made resistant to tylosin were also resistant to erythromycin, whereas mutants made resistant to erythromycin were not always resistant to tylosin. Some M. iowae tiamulin-resistant mutants were also resistant to both macrolide antibiotics. Enrofloxacin and oxytetracycline did not induce any cross-resistance to the other antibiotics tested. These results show that Mycoplasma resistance to macrolides can be quickly selected in vitro, and thus, providing that similar results could be obtained under field conditions, that development of resistance to these antibiotics in vivo might also be a relatively frequent event. 相似文献
16.
One hundred and thirteen finishing pig units and 74 sow units in Catalonia, Spain, were examined to determine the prevalence of salmonella infections and the factors that could be associated with them. Pooled faecal samples were taken from the finishing units, and samples of faeces were collected from individual sows. The Salmonella isolates were serotyped, phage typed and examined for their antimicrobial susceptibility to 18 common antimicrobial drugs. In addition, blood samples from pigs on 141 farms were analysed by ELISA. In both the bacteriological and serological surveys, a questionnaire with 84 questions was completed for each farm. Salmonella species were isolated from 20 per cent of the finishing units and 24 per cent of the sow units; 14 serotypes were detected in the finishing pigs and 11 in the sows. More than 30 per cent of the strains were resistant to tetracycline, sulphonamides, ampicillin or streptomycin, and 69 per cent of the strains were resistant to three or more agents up to 10 compounds. Seventy-seven per cent of the farms had at least one seropositive animal, and 26 per cent of these farms had an individual seroprevalence of 50 per cent or more. The factors associated (P<0.05) with the excretion of Salmonella species in the finishing units were the practice of raising livestock other than pigs (odds ratio [OR]=6.18), the herd size (OR=5.87), and a past history of clinical salmonellosis (OR=4.97). For the sows, the factors associated (P<0.05) with the excretion of Salmonella species were having open-flushed drainage of sewage (OR=34.48), a lack of rodent control measures (OR=0.05) and the number of sows in the unit (OR=9.26). Factors associated with seropositivity in the finishing units were a lack of bird-proof nets (OR=0.30) and the use of water from private wells (OR=3.64). 相似文献
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18.
Western blots of proteins of 14 Mycoplasma iowae strains and isolates resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were probed with three monoclonal antibodies (MAbs), MI6, MI7, and MI8. MAb MI6 reacted with one or more antigens with apparent molecular weights of 60,000, 70,000, and 94,000. In three strains (N-PHN-D13, R-D2497, and K 1805), antigens located on a single peptide band were recognized, while in others additional epitopes at different molecular-weight positions were revealed. A similar pattern was observed with MAb MI7, although it reacted with fewer antigens than did MAb MI6 and failed to recognize antigens in strains N-PHN-D13 and R-D2497. MAb MI8 reacted with an antigen at an apparent molecular-weight position of 28,000 in four of the 14 strains and isolates. The diverse reaction patterns observed with the MAbs in the 14 M. iowae strains and isolates confirms the occurrence of antigenic variation within this species. Antigenic variation in M. iowae may be pivotal in determining host-parasite interactions, pathogenesis, and the outcome of disease. 相似文献
19.
Fluorescent antibody technique has been used as a diagnostic tool for the identification of pathogenic avian Mycoplasma species. Fluorescein-conjugated antisera for Mycoplasma iowae prepared from rabbit hyperimmune serum against one serotype (I) has not always been reliable, giving false-negative results. A fluorescein-conjugated antisera was prepared with antibody against the six identified serotypes (I, J, K, N, Q, and R) that comprise the species M. iowae. This heterogeneous conjugate was used to positively identify M. iowae in field isolates and lab strains, while maintaining specificity. Polymerase chain reaction specific for M. iowae was used to determine specificity. 相似文献
20.
Diets with 16.5, 14.5, 12.5 and 10.5 per cent protein and 2765 k cal. metabolisable energy per kg. and a fifth diet containing 10.5 per cent protein and 2165 k cal. M.E./kg. were fed to Rhode Island Red x Light Sussex pullets and to “hybrid” pullets which weighed 33 per cent less and produced 20 per cent more eggs. Both strains had protein requirements of the order of 20 g./bird/day. It is possible that the assumed higher requirement of the “hybrid” pullets for productive purposes was offset by a smaller requirement for maintenance and growth. Expressed as a percentage of a 2765 k cal. diet, the small strain required at least 16.5 per cent protein and the large strain no more than 12.5 per cent protein for maximum performance. Both strains performed well on the 2165 k cal., 10.5 per cent protein diet, illustrating that high energy diets are not essential for small strains of pullets.
Egg size was reduced by protein restriction in the heavy strain but not in the light strain. On isocaloric diets the light strain consumed more food only at the lowest protein level whereas the heavy strain tended to eat progressively more as the protein was reduced from 16.5 to 12.5 per cent. When offered the low energy diet both strains ate more food, but substantially fewer calories, than when given diets of 2765 k cal. M.E./kg. Protein restriction had a marked effect in reducing live‐weight gains. Energy level of the diet had a large effect on weight gain and also on fat deposition in the carcass.
The greatest differences in performance due to diet did not occur at the time of maximum egg output. The evidence indicates that a diet which is too low in protein to support peak egg production will also fail to support normal egg production at any later stage of the laying year. 相似文献