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1.
Isolation of Mycobacterium paratuberculosis from sheep and cattle in Iceland. Acta vet. scand. 1979, 20, 191–199. — Culture experiments concerning the Icelandic variant of Mycobacterium paratuberculosis are described. Various decontaminating agents and culture media were employed and the colonial morphology of freshly isolated strains on different media described. The growth rate and culture requirements are compared with those of the Norwegian goat-pathogenic variant of M. paratuberculosis. For primary isolation modified Herrold’s medium gave the best results. However, on all the various culture media used, the growth of the Icelandic variant was much more sporadic than that of the Norwegian goatpathogenic variant. It is concluded that bacteriological culture is not useful for the diagnosis of Johne’s disease caused by the Icelandic variant of M. paratuberculosis.  相似文献   

2.
Analysis of antigens in Mycobacterium paratuberculosis. Acta vet. scand. 1979, 20, 200–215. — Using crossed immunoelectrophoresis (GIE) and crossed line immunoelectrophoresis (GLIE), antigens from different strains and variants of Mycobacterium paratuberculosis were compared, and cross-reactions between 1 of these strains and Mycobacterium avium and BGG studied. In each of 4 bovine laboratory strains of M. paratuberculosis examined, altogether 44 different antigens were demonstrated. This is the largest number of antigens in M. paratuberculosis which has been described so far. No important difference in the antigenic structure of the strains was found. The 4 laboratory strains are being used routinely in the production of vaccine against Johne’s disease in Norway and Iceland. One of the aims of the present work was to investigate the antigenic relationship between these strains and the goat-pathogenic Norwegian and the Icelandic variant of M. paratuberculosis. Out of 44 different antigens demonstrated in the laboratory strains, 39 and 31 gave cross-reactions against the Norwegian and the Icelandic variant, respectively. This is in accordance with practical experience, as the results of vaccination against Johne’s disease, performed in Norway for many years, are very good. Twenty-seven and 24 cross-reacting antigens between M. paratuberculosis and strains of M. avium and BGG, respectively, were observed. This finding agrees with clinical observations. Another aim of the investigation was to identify species-specific antigens as regards M. paratuberculosis. One antigen showed a marked cross-reaction between the strains of M. paratuberculosis examined, but did not react with antisera against M. avium and BGG. Some other antigens showed partial specificity. The results obtained stress the complicated antigenic situation in mycobacteria which is of decisive significance as regards the diagnosis and classification of mycobacterial infections.  相似文献   

3.
About half (49%) of strains of Staphylococcus aureus isolated from poultry were non-typable with the international human set of phages, and 55% were biotype B according to the biochemical identification scheme of Hájek & Maršálek (1971, 1973). A furthest neighbour clustering strategy and principal coordinate analysis based on 17 biochemical tests made clear distinctions between biotype B strains and a group of biotype A and intermediate strains. Overall 62% of strains were enterotoxigenic, the majority producing enterotoxin A. Significantly fewer intermediate strains than biotype A or B strains were enterotoxigenic. Starch gel zymograms of intracellular esterases showed a general correlation with the biotyping and phage typing results.  相似文献   

4.
Mycobacterium malmoense was isolated from a soil sample, and biological, biochemical, antigenic, and genetic characteristics of the isolate were described. This is the first report of isolation of this organism in Japan.  相似文献   

5.
A microbiological study of the mycoplasma flora in the respiratory tracts of cattle and goats in selected regions of Tanzania is described. In the examination of cattle, mycoplasmas were isolated from 60 (17.8%) of the 338 examined lung samples, 8 (47.1%) of the 17 lymph nodes, 4 (13.3%) of the 30 pleural fluid samples and 4 (3.9%) of the 103 nasal swabs examined. All the isolates were identified as Mycoplasma mycoides subsp. mycoides, Small Colony type except for one isolate from pleural fluid which was identified as Mycoplasma arginini. M. mycoides subsp. mycoides, Small Colony type was isolated from samples originating from Dodoma, Iringa, Mbeya, Morogoro and Shinyanga regions where outbreaks of contagious bovine pleuropneumonia had been reported. In the examination of goats, mycoplasmas were isolated from 54 (34.0%) of the 159 examined lung samples, 41 (18.1%) of the 226 nasal swabs and 4 (40.0%) of the 10 pleural fluid samples. The species demonstrated were Mycoplasma capricolum subsp. capripneumoniae, M. mycoides subsp. mycoides, Small Colony type Mycoplasma ovipneumoniae and M. Capricolum subsp. arginini. The isolation of M. capripneumoniae in the Coast and Morogoro regions confirmed the presence of contagious caprine pleuropneumonia in the regions.  相似文献   

6.
Paratuberculosis (ParaTB), caused by Mycobacterium avium subspecies paratuberculosis (MAP) is a chronic enteritis of ruminants and may contribute to Crohn's disease in humans. Key features of host immunity to MAP infection include an early pro-inflammatory (Th1-like) response that eventually gives way to a predominant anti-inflammatory (Th2-like) response. Many studies have been conducted to understand the underlying mechanism of misdirected host immune response, however, these studies mainly focused on cattle. The present study is the first attempt to test the hypothesis of shift in Th1 to Th2 like responses during the progression of ParaTB in caprine species (small ruminant). Ten healthy male kids (<6 months old) of the same breed were selected for this study. Of the 10 kids, 6 were experimentally infected with native strain (S5) of MAP (“Indian Bison Type”) and the remaining 4 kids were control. Kids were monitored for a period of 12 months post infection (MPI) and were tested for establishment of infection. Expression levels of IFNG, IL2, IL12, IL4, and IL10 genes were estimated before infection and at 4, 8, and 12 MPI in stimulated peripheral blood mononuclear cells (PBMCs) of infected and control kids. The study demonstrated the expression of IFNG and IL2 as classic Th1-like pro-inflammatory signatures; whereas, IL10 exhibited itself as classical Th2-like signature. The study also reports unexpected lowered expression of the IL12 gene simultaneously with increased expression of IFNG, lowered expression of the IL2 gene (compared to IFNG), and suppressed expression of the IL4.  相似文献   

7.
Membrane fractions have been isolated from maize (Zea mays L.)roots by discontinuous density gradient centrifugation and phaseseparation methods. A number of approaches were tried with theaim of identifying specific membrane types, especially the plasmamembrane. These included the use of enzymic markers, determinationof glucose and leucine incorporation, separation of membraneproteins by SDS-PAGE, and attempts to identify the plasma membranefraction by cell surface labelling. The results are discussedin relation to the usefulness of membrane markers and the difficultiesof isolating surface membranes from higher plant tissues.  相似文献   

8.
The isolation of Aeromonas punctata (hydrophila, liquefaciens) from feces, throat, and sputum cultures is presented as further evidence that aeromonads are found in man. Morphological and biochemical studies of these strains indicate that the chief differences between the aeromonads and physiologically similar members of the Enterobacteriaceae are found in the polar arrangement of the flagella and in the production of oxidase by the former. The oxidase test should be performed on all paracolon-like bacteria, and a flagella stain should be employed when an oxidase-positive, gram-negative bacillus is isolated. Application of these tests will undoubtedly result in more frequent identification of Aeromonas species from human sources.  相似文献   

9.
10.
Establishment or maintenance of a persistent infection by Mycobacterium tuberculosis requires the glyoxylate pathway. This is a bypass of the tricarboxylic acid cycle in which isocitrate lyase and malate synthase (GlcB) catalyze the net incorporation of carbon during growth of microorganisms on acetate or fatty acids as the primary carbon source. The glcB gene from M. tuberculosis, which encodes malate synthase, was cloned, and GlcB was expressed in Escherichia coli. The influence of media conditions on expression in M. tuberculosis indicated that this enzyme is regulated differentially to isocitrate lyase. Purified GlcB had K(m) values of 57 and 30 microm for its substrates glyoxylate and acetyl coenzyme A, respectively, and was inhibited by bromopyruvate, oxalate, and phosphoenolpyruvate. The GlcB structure was solved to 2.1-A resolution in the presence of glyoxylate and magnesium. We also report the structure of GlcB in complex with the products of the reaction, coenzyme A and malate, solved to 2.7-A resolution. Coenzyme A binds in a bent conformation, and the details of its interactions are described, together with implications on the enzyme mechanism.  相似文献   

11.
Some relationships among Schaefer's serotypes and biological and biochemical characteristics were observed in strains of the Mycobacterium avium-Mycobacterium intracellulare complex. Strains belonging to serotypes 2 and 16 lacked the capacity to utilize n- and iso-butanols as the sole source of carbon in the presence of ammoniacal nitrogen. However, strains of serotype 2 grew at 45 C and lacked arylsulfatase activity (after 14 days), whereas strains of serotype 16 failed to grow at 45 C and showed positive arylsulfatase activity. Strains belonging to serotypes 8, 9, and 15 grew at 45 C, utilized n- and iso-butanols, and showed arylsulfatase activity.  相似文献   

12.
13.
Twenty-four flocks comprising 2370 breeding goats were examined. Threehundred-and-sixty-nine (15.6 %) of the goats either aborted or delivered dead kids at full term, or were barren. In 23 of the herds the rate of reproductive loss ranged from 2 % to 36 %, whereas in one herd all of 54 mated goats had live kids. A loss of ≥ 20 % was found in 9 herds comprising 799 goats. In 11 herds comprising 946 goats the rate of reproductive failure was ≤ 10 %. The incidence of reproductive failure was higher in older goats than in those in their first or second pregnancy. The causes were identified in only about 3 % of the goats that aborted. It is concluded that reproductive failure in many flocks probably is associated with non-infectious causes such as nutritional and environmental factors.  相似文献   

14.
SYNOPSIS. Mitochondria were isolated from Euglena gracilis strain Z by pressure-breakage of the cells and sucrose-cushion centrifugation. Multiple peaks (2-4) were observed in the rate of phosphorylation with Mg-ADP-phosphate concentration curves. The phosphorylative and oxidative activities were highest with NADH as the substrate, moderate with succinate, and lowest with glutamate. Inhibition of phosphorylation with 2,4-dinitrophenol and carbonyl cyanide, m-chlorophenylhydrazone gave sigmoidal concentration curves, with the extent of inhibition by DNP depending on the substrate used. Inhibition of phosphorylation by valinomycin, atractyloside, or carboxyatractyloside was only ~ 60%. Oligomycin inhibited phosphorylation in 2 phases at low and high concentrations; it inhibited Mg-ATPase in a sigmoidal fashion. Both phosphorylation and oxidation had discontinuities in Arrhenius plots at 34 C and 18 C. The relative Mg2+-dependent nucleoside triphosphatase activity was: 1 for ATP and GTP, 0.6 for ITP, 0.15 for CTP and and UTP; with Ca2+ in place of Mg2+ this activity was 0.35. Both DNP and CCCP stimulated the Mg-ATPase 50-200%. The optimal pH for the stimulation was ~ 7 regardless of the uncoupler used, and ~ 8 without the uncouplers. The few differences observed between mitochondria from Euglena and those from other sources are probably due to the fragmentation of the reticular mitochondrial structure during isolation and not to unique characteristics of these mitochondria.  相似文献   

15.
Uracil phosphoribosyltransferase (UPRT) catalyzes the conversion of uracil and 5-phosphoribosyl-α-1-pyrophosphate (PRPP) to uridine 5′-monophosphate (UMP) and pyrophosphate (PPi). UPRT plays an important role in the pyrimidine salvage pathway since UMP is a common precursor of all pyrimidine nucleotides. Here we describe cloning, expression and purification to homogeneity of upp-encoded UPRT from Mycobacterium tuberculosis (MtUPRT). Mass spectrometry and N-terminal amino acid sequencing unambiguously identified the homogeneous protein as MtUPRT. Analytical ultracentrifugation showed that native MtUPRT follows a monomer-tetramer association model. MtUPRT is specific for uracil. GTP is not a modulator of MtUPRT ativity. MtUPRT was not significantly activated or inhibited by ATP, UTP, and CTP. Initial velocity and isothermal titration calorimetry studies suggest that catalysis follows a sequential ordered mechanism, in which PRPP binding is followed by uracil, and PPi product is released first followed by UMP. The pH-rate profiles indicated that groups with pK values of 5.7 and 8.1 are important for catalysis, and a group with a pK value of 9.5 is involved in PRPP binding. The results here described provide a solid foundation on which to base upp gene knockout aiming at the development of strategies to prevent tuberculosis.  相似文献   

16.
Culture is considered the definitive technique for Johne's disease diagnosis, and it is essential for later applications of certain molecular typing techniques. In this study, we have tested four solid media (Herrold's egg yolk medium [HEYM] with sodium pyruvate and mycobactin [HEYMm-SP], HEYM with mycobactin and without sodium pyruvate [HEYMm], Middlebrook 7H11 with mycobactin [Mm], and Löwenstein-Jensen with mycobactin [LJm]) for isolation of Mycobacterium avium subsp. paratuberculosis strains in 319 tissue samples from cattle herds and goat flocks. We have shown that each of the two main groups of M. avium subsp. paratuberculosis (type II and type I/III) has different requirements for growth in the culture media studied. The recommended solid media for isolation of type I/III strains are LJm and Mm, since the combination of both media allowed the recovery of all these strains. The most widespread culture medium, HEYM, is not suitable for the isolation of this group of M. avium subsp. paratuberculosis strains. Regarding the type II strains, HEYMm-SP was the medium where more strains were isolated, but the other three media are also needed in order to recover all type II strains. The incubation period is also related to the strain type. In conclusion, because the type of strain cannot be known in advance of culture, coupled with the fact that cattle and goats can be infected with both groups of strains, we recommend the use of the four solid media and the prolongation of the incubation period to more than 6 months to detect paratuberculous herds/flocks and to determine the true prevalence of the infection.  相似文献   

17.
Five proteins having molecular masses of 90, 67, 37, 36, and 32 kDa (p90, p67, p37, p36, and p32, respectively) were identified in the particulate fractions of pig brain cortex and pig spinal cord prepared in the presence of 0.2 mM Ca2+ and further purified using a protocol previously described for the purification of calpactins. Proteins p90, p37, and p36 are related to annexins I and II. Annexin II, represented by p90, is found as an heterotetramer, composed of two heavy chains of 36 kDa and two light chains of 11 kDa, and as a monomer of 36 kDa. Protein p37, which differs immunologically from p36, is a monomer and could be related to annexin I. All three proteins are Ca(2+)-dependent phospholipid- and F-actin-binding proteins; they are phosphorylated on a serine and on a tyrosine residue by protein kinases associated with synaptic plasma membranes. Purified p36 monomer and p36 heterotetramer proteins bind to actin at millimolar Ca2+ concentrations. The stoichiometry of p36 binding to F-actin at saturation is 1:2, corresponding to one tetramer or monomer of calpactin for two actin monomers (KD, 3 x 10(-6) M). Synaptic plasma membranes supplemented with the monomeric or tetrameric forms of p36 phosphorylate the proteins on a serine residue. The monomer is phosphorylated on a serine residue by a Ca(2+)-independent protein kinase, whereas the heterotetramer is phosphorylated on a serine residue and a tyrosine residue by Ca(2+)-dependent protein kinases. Antibodies to brain p37 and p36 together with antibodies to lymphocytes lipocortins 1 and 2 were used to follow the distribution of these proteins in nervous tissues. Polypeptides of 37, 34, and 36 kDa cross-react with these antibodies. Anti-p37 and antilipocortin 1 cross-react on the same 37- and 34-kDa polypeptides; anti-p36 and antilipocortin 2 cross-react only on the 36-kDa polypeptides.  相似文献   

18.
The present study aimed to identify and characterize plasmids in a national collection of oral Enterococcus faecalis (n = 106) isolated from patients with marginal periodontitis. Plasmid replicon typing was performed by multiplex-PCR and sequencing with specific primers for 18 rep-families and 1 unique sequence. Additional plasmid analysis by S1-PFGE was performed for comparison. Totally 120 plasmid replicon amplicons of seven rep-families were identified in 93 E. faecalis strains, e.g. rep9 (prototype pCF10), rep6 (prototype pS86), rep2 (prototype pRE25/pEF1), and rep8 (prototype pAM373). Rep9 was the most predominant rep-family being detected in 81 (76.4%) strains. Forty of these strains were tetracycline resistant and three were erythromycin resistant. Rep6 was the second predominant rep-family being detected in 22 (20.8%) strains. Rep2 was detected in eight (7.5%) strains. All rep2-positive strains were resistant to tetracycline and/or erythromycin and six of them contained Tn916/Tn1545 genes. The rep-positive E. faecalis exhibited divergence in multilocus sequence types (STs). There was a significant correlation between rep9 and ST21, while multiple rep-families appeared in ST40. Totally 145 plasmid bands were identified in 95 E. faecalis strains by S1-PFGE, 59 strains carrying one plasmid, 27 carrying two, five carrying three, three carrying four, and one strain carrying five plasmids. Plasmid sizes varied between 5–150 kbp. There was a significant correlation between the number of plasmids identified by PCR rep-typing and by S1-PFGE. The results indicate that the majority of E. faecalis of marginal periodontitis are likely to be a reservoir for diverse mobile genetic elements and associated antimicrobial resistance determinants.  相似文献   

19.
条斑紫菜中R-藻红蛋白的生化特性   总被引:5,自引:0,他引:5  
条斑紫菜的R-藻红蛋白(R-PE),在CM-52柱上用含8mol/L脲的0.02mol/L乙酸铵缓冲液(pH=5.05)洗脱,观察到3条色带,经吸收光谱测定表明,它们分别是α、β、γ亚基。用SDS-PAGE测定的α、β和γ亚基分子量分别是17.0kd,18.0kd和31.7kd。R-PE中亚基的摩尔比是6α:6β:1γ。条斑紫菜的R-PE最稳定的聚集态分子量是229kd。各亚基的发色团含量:α亚基含2个藻红胆素(PEB),β亚基含1个PEB和0.5个藻尿胆素(PUB),γ亚基含2个PEB和3个PUB。结合R-PE和各亚基的氨基酸组成分析,条斑紫菜的R-PE亚基组成是(αβ)6γ。  相似文献   

20.
Faecal samples from 95 healthy pigs and samples of jejunal content from 85 piglets suffering from colienterotoxaemia were tested for the presence of drug resistant E. coli strains. Practically all pigs in both groups harboured E. coli strains resistant to one or more of the 6 antibiotics/chemotherapeutic agents tested (Oxytetracycline, streptomycin, sulphaisodimidin, neomycin, ampicillin, chloramphenicol). Almost 100% of healthy and approx. 90% of diseased pigs harboured strains resistant to Oxytetracycline, streptomycin and sulphaisodimidin. Pigs with strains resistant to neomycin, ampicillin and chloramphenicol were less frequently found. The predominant coliform flora consisted of E. coli strains” resistant to Oxytetracycline, streptomycin and sulphaisodimidin in 71% to 81% of diseased pigs and in 47% to 69% of the healthy pigs. In diseased pigs ¾ of the animals had a coliform flora dominated by neomycinresistant E. coli strains. Of the 721 resistant E. coli strains isolated from healthy pigs, 11% were single resistant while the corresponding figure for the 518 resistant strains isolated from diseased pigs was 6%. Thus 89% and 94% of strains showed simultaneous resistance to 2 or more antibiotics. E. coli strains resistant to 3 or more drugs were found in approx. 60% and 70% of the isolates from healthy and diseased animals, respectively. Oxytetracycline/streptomycin/sulphaisodimidin resistance was most commonly found, approx. 22% and 38% of the strains from healthy and diseased pigs, respectively, showing this resistance pattern. Transmission of drug resistance which was examined in E. coli strains originating from the diseased pigs was demonstrated in approx. 76% of the isolates. The incidence of drug resistance transfer in single, double, triple and quadruple resistant strains was 11%, 68%, 97% and 98%, respectively.  相似文献   

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