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1.
I D Heron A N Morrow 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1989,36(1):69-75
The anti-bacterial activity of 13 commercially available acaricides, in use in the Caribbean, was tested against Dermatophilus congolensis, an actinomycete involved in streptothricosis of cattle, sheep and goats in the tropics. Acaricides used included organochloride, organophosphorus, carbamate, pyrethroid and amidine compounds. Each acaricide was tested at a typical working dilution used by the farmers, at 25 degrees C and 37 degrees C, in the presence or absence of 15 percent newborn calf serum as a fouling agent. Fouling of acaricides was found to have a marked inhibitory effect on its anti-bacterial activity. Vapona and Cattle Washing Detergent were found to be more active against Dermatophilus congolensis than the other acaricides tested. 相似文献
2.
L T Zaria 《Research in veterinary science》1991,50(2):245-246
When tested on solid media the growth of 19 Dermatophilus congolensis strains was inhibited by antibiotic-producing staphylococci isolated from pigs. Two strains, D congolensis D11 and D15, which were very sensitive to the producers and caused lesions of dermatophilosis in a mouse model, were further used to investigate the ability of the producers to inhibit lesion formation by the strains of D congolensis. The simultaneous application of the antibiotic-producing staphylococci and D congolensis suppressed formation of the lesions in the mouse. 相似文献
3.
A monoclonal antibody (McAb) to Dermatophilus congolensis was produced from murine hybridoma cultures and purified by affinity chromatography. Species specificity was demonstrated using indirect immunofluorescent staining; the McAb was shown to react with 10 D congolensis isolates but not with 10 Nocardia species isolates, a Rhodococcus and a Streptomyces species isolate. The McAb was used to demonstrate D congolensis in clinical material from confirmed bovine and ovine cases and presumptive equine cases of dermatophilosis by indirect immunofluorescent staining. 相似文献
4.
Antigenic diversity within a collection of 18 isolates of Dermatophilus congolensis from different Continents was examined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and by Western blotting with sera from cattle with clinical dermatophilosis using whole cell extracts obtained by three methods and one extract of extracellular products of D. congolensis. One of the methods involving the release of a lysostaphin-solubilized protein (LSP) of whole cells of D. congolensis revealed a number of discrete and easily-identifiable bands in SDS-PAGE which were found suitable for characterizing protein patterns and was, therefore, subsequently used for a comparative analysis of the proteins of all the D. congolensis isolates. Six electropherotypes (ET) of D. congolensis were identified among the 18 isolates using the protein profiles based on the presence of four protein bands at Molecular weights (MW) 62, 28, 17.4 and 16.4 kDa. The ETs were found among isolates from different animal species and from different sources with ET1 consisting of three bovine and two equine isolates; ET2, two bovine and three ovine isolates; ET3, two bovine isolates; ET4, two bovine isolates; ET5, one bovine and one ovine isolates and ET6, two bovine isolates. Immunoblotting of the extracts of D. congolensis isolates with sera from cattle with clinical dermatophilosis infection demonstrated protein bands of MW ranging from 9 kDa to 188 kDa. Sera from chronic dermatophilosis infection demonstrated a 28 kDa protein which was immunodominant in the LSP extracts of all the 18 isolates of D. congolensis tested while sera from mild infections demonstrated mainly the 62 kDa protein in the same extracts. However, many protein bands were demonstrated in surface membrane (TSMP) and extracellular protein extracts with sera from only mildly infected animals. The protein patterns observed in all isolates of D. congolensis revealed global antigenic similarities and distinct differences among isolates which could not be associated with either geographic, climatic or host factors. Also sera from infected animals from endemic regions of dermatophilosis could not differentiate isolates of D. congolensis. This suggests the possibility that such sera must have come from animals that had been infected by a multitude of D. congolensis strains present in the herd environment and strains an animal could have come across during the 'ritual' annual cross-country migration of the cattle herds. 相似文献
5.
Cross-protection studies were conducted with vaccines prepared from two isolates of Dermatophilus congolensis (designated strain 1 and strain 2). The vaccines were prepared as either heat-inactivated, washed, formalized filamentous phase bacterium, mixed with alum as an adjuvant, and inoculated intramuscularly (type A vaccine) or sedimented live filaments inoculated intradermally (type B vaccine). The vaccinated sheep were challenged with D. congolensis zoospores of one or other strain. Challenge sites were observed for the presence and severity of lesions. Serum antibody levels to D. congolensis were monitored after vaccination and challenge. Type A and B vaccines from both strains produced some reduction in the severity of lesions when sheep were challenged with strain 1 but not with strain 2. Unvaccinated control sheep developed more severe and persistent lesions when challenged with strain 2 than controls challenged with strain 1. Serum antibody levels to the type B vaccine prepared from strain 1 were significantly higher (P less than 0.05) than antibody levels to type B vaccine from strain 2. These findings showed there was significant variation in virulence and antigenicity between these two isolates of D. congolensis. 相似文献
6.
I F Salkin M A Gordon W B Stone 《Journal of the American Veterinary Medical Association》1975,167(7):571-573
Infection by both Dermatophilus congolensis and Alternaria alternata was found in a 5 1/2-year-old, female white-tailed deer (Odocoileus virginianus). Encrusted lesions characteristic of dermatophilosis were observed on the hocks, flanks, and back. Giemsa-staining of smears of material from beneath the crusts revealed branching filaments, transversely and longitudinally divided into packets of coccoid cells typical of D congolensis. Hyphae morphologically consistent with those of A alternata were found in methenamine-silver- and hematoxylin-and-eosin-stained sections of tissue from the ears, flanks, and back. Nutrient agar cultures inoculated with tissue from an ear and hindlimb of the deer yielded, respectively, A alternata and D congolensis. 相似文献
7.
Serodiagnosis of Dermatophilus congolensis infection by counterimmunoelectrophoresis 总被引：1，自引：0，他引：1
Sixty-one sera from animals that had contact with Dermatophilus congolensis were examined by comparing three serological methods; counterimmunoelectrophoresis, passive haemagglutination, and agar gel diffusion, and by using four different antigenic extracts of D congolensis. The counterimmunoelectrophoresis was the most satisfactory of the methods having been found to be specific and sensitive, easy to perform and suitable for screening large numbers of samples. It was also found to have a higher antibody detection rate (82.2 per cent) than the other methods thus making it suitable for seroepidemiological surveys. It was found to be capable of detecting multiple antibodies and also revealed dissimilarities among the different antigenic extracts. The cellular antigens of D congolensis were found to detect antibody in more sera than the extracellular antigen; the cell wall extract proved to be the most satisfactory of all, detecting antibody from the largest number of sera compared to the other extracts in all the three serological tests. 相似文献
8.
9.
B Skalka L Pospísil 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1992,39(2):139-143
The strains of Dermatophilus congolensis grew on blood agar with washed sheep erythrocytes with marked total hemolysis. In testing for hemolytic interactions they gave a significant synergistic effect of a characteristic shape with Rhodococcus equi and Streptococcus agalactiae, whereas with Staphylococcus aureus producing beta hemolysin and with Staphylococcus aureus producing delta hemolysin a simultaneous synergistic as well as antagonistic effect were observed. First of all a conspicuous inhibition of in the beta hemolysin zone began and then the hemolytic effect of D. congolensis was enhanced. A similar double reaction was also observed with Listeria ivanovii. With delta hemolysin there was an inhibition of the hemolytic effect of D. congolensis and at the same time a synergistic effect could be observed. Also D. congolensis gave a weak synergistic effect with Micrococcus lylae and Listeria monocytogenes, and a further weak antagonistic effect with alpha hemolysin of Staphylococcus aureus, Staphylococcus hyicus, Staphylococcus chromogenes and Micrococcus luteus. No interaction of D. congolensis was established with Corynebacterium pseudotuberculosis. 相似文献
10.
Components of inflammatory and immunological responses were compared in 17 Merino sheep with chronic dermatophilosis (Group 1) and 15 Merino sheep that had recovered from the disease (Group 2). The functions studied included: (i) total and differential white cell counts; (ii) phagocytic function and intracellular killing by neutrophils; (iii) humoral immune response to T-dependent and T-independent antigens and to Dermatophilus congolensis. (iv) lymphocyte blastogenic responses to phytohaemagglutinin; (v) bovine serum albumen and D. congolensis antigens; (vi) quantification of T-lymphocyte subsets in skin lesions resulting after re-infection with D. congolensis zoospores. After all lesions were treated and the sheep were shorn, both groups of sheep were re-infected with D. congolensis. Both groups had similar infection rate, severity of lesions and rate of resolution after re-infection. The Group 2 sheep had significantly higher primary and secondary antibody responses to killed Brucella abortus cells than Group 1 sheep, but Group 1 sheep had higher levels of specific D. congolensis antibody throughout the trial. Neutrophils from Group 1 sheep showed a higher phagocytic rate for D. congolensis zoospores than Group 2 sheep when the zoospores were opsonised by sera from the Group 1 sheep, but there was no difference in their ability to kill ingested zoospores. Although there were some differences between the groups in the proportion of lymphocytes in lesions that reacted with monoclonal antibodies to T4, T8 and T19-19 lymphocyte markers at various times after re-infection, the sheep in Group 2 consistently had higher levels of lymphocytes reacting to a monoclonal antibody for the T6 lymphocyte antigen in skin biopsies collected 9, 15 and 21 days post-inoculation (p.i.) than did sheep in Group 1. Group 2 sheep also had higher levels of epidermal cells with immunohistochemical properties of Langerhans cells at lesion sites 15 and 21 days p.i. 相似文献
11.
Quantification of a T6-lymphocyte antigen in peripheral blood mononuclear cells of sheep was used to select 15 from 48 one year old Merino ewes not previously exposed to Dermatophilus congolensis infection. These sheep were compared in response to challenge with D. congolensis zoospores and levels of T-6 lymphocyte antigen in peripheral blood mononuclear cells with 15 Merino ewes of similar age and strain from a different site that had been treated and recovered from chronic dermatophilosis. The T-6 lymphocyte antigen levels were significantly lower in the chronic dermatophilosis sheep and they developed significantly more severe lesions than the selected, previously unexposed sheep despite the former sheep having high serum antibody levels to D. congolensis. Measurement of the fleece characteristics, wax and suint concentration showed no differences between the groups that might have explained the considerable differences in their susceptibility to dermatophilosis. 相似文献
12.
Humoral and cell-mediated immune response to crude antigens of Dermatophilus congolensis during experimental infection of rabbits. 
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下载免费PDF全文 Rabbits were infected with Dermatophilus congolensis and tested for humoral immune response by indirect haemagglutination and for cell-mediated immune response to crude antigens of D. congolensis. Lymphocyte transformation and macrophage migration inhibition assays were used as in vitro correlates of cell-mediated immune response while cutaneous delayed hypersensitivity was used in vivo. Endo-antigen and whole cell antigen were found to significantly induce cell-mediated immune response. In contrast, humoral responses were found to be more significantly induced by exo-antigen. A biphasic immune response was revealed by the lymphocyte transformation test. 相似文献
13.
The cellular response in the skin of Merino sheep was examined after three successive inoculations with Dermatophilus congolensis. There was a massive neutrophil influx into the infected epidermis and underlying dermis at 4-10 days after the first inoculation. A lymphocyte-macrophage response occurred at 10-12 days, followed by a plasma cell response at 14-38 days. Resolution of skin lesions after the first inoculation corresponded to the time when the plasma cell response in the skin was most intense. A second inoculation with D. congolensis, 70 days after the first, failed to produce skin lesions typical of dermatophilosis. Typical lesions of dermatophilosis did develop after a third inoculation of the same sheep 140 days after the first inoculation, but the lesions resolved in most sheep within 13 days. Dermatophilosis did not develop in some of these sheep at sites inoculated with 100-1000-fold lower infective doses of D. congolensis, whereas control sheep did develop lesions. 相似文献
14.
Larrasa J Garcia A Ambrose NC Alonso JM Parra A de Mendoza MH Salazar J Rey J de Mendoza JH 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2002,49(3):135-141
Dermatophilus congolensis is the pathogenic actinomycete that causes dermatophilosis in cattle, lumpy wool in sheep and rain scald in horses. Phenotypic variation between isolates has previously been described, but its genetic basis, extent and importance have not been investigated. Standard DNA extraction methods are not always successful for D. congolensis due to its complex life cycle, one stage of which is encapsulated. Here we describe the development of rapid and reliable DNA extraction and random amplified polymorphic DNA (RAPD) methods that can be used for genotyping D. congolensis field isolates. Our results suggest that genotypic variation between isolates correlates with host species. Several DNA extraction methods and RAPD protocols were compared. An extraction method based on incubation of the bacterium in lysozyme, sodium dodecyl sulphate (SDS) and proteinase K treatments and phenolic extraction yielded high-quality DNA, which was used to optimize RAPD-polymerase chain reaction (PCR) protocols for two random primers. An alternative rapid, non-phenolic extraction method based on proteinase K treatment and thermal shock was selected for routine RAPD typing of isolates. DNA extracted from reference strains from cattle, sheep and horse using either method gave reproducible banding patterns with different DNA batches and different thermal cyclers. The rapid DNA extraction method and RAPD-PCR were applied to 38 D. congolensis field isolates. The band patterns of the field and type isolates correlated with host species but not with geographical location. 相似文献
15.
绵羊刚果嗜皮菌的分离鉴定及某些生物学特性研究 总被引：1，自引：0，他引：1
从疑似嗜皮菌感染绵羊的皮肤疙瘩病料中分离到1株细菌,通过对其形态、培养特性、生长特征、生理生化特性、16S rRNA基因序列测定与同源性分析等研究,证明分离株为刚果嗜皮菌。人工感染羔羊表现出与自然发病绵羊相同的症状并死亡,从人工感染死亡绵羊皮肤中再次获得同种细菌。药敏试验结果表明:该菌对林可霉素、卡那霉素、氧氟沙星、复方磺胺、土霉素、氟苯尼考高度敏感。 相似文献
16.
The host cell-mediated immune response was examined following experimentally-induced infection of rats with Dermatophilus congolensis, the causal agent of the skin disease dermatophilosis. Mononuclear cells (MC) isolated from Wistar rats 10 days following the induction of a third infection underwent a strong and specific proliferative response, as assessed by a [3H]thymidine incorporation assay, when cultured with various concentrations of inactivated D. congolensis cocci. Using specific monoclonal antibodies in an indirect fluorescent antibody test, this in vitro response was found to be characterised by a large expansion of the W3/25 (T-helper phenotype) population to form 56% of the total. Finally, the primed and stimulated MC were assessed for their ability to produce factors capable of inhibiting macrophage migration. The culture supernatants of D. congolensis-stimulated MC from infected rats caused significant migration inhibition of normal rat peritoneal exudate cells, whilst the supernatants of similarly-stimulated MC from naive rats failed to cause significant inhibition. The results show that a MC subpopulation becomes primed following experimentally-induced infection with D. congolensis and becomes activated after subsequent, in vitro, exposure. 相似文献
17.
Zoospores of Dermatophilus congolensis were analysed by SDS-PAGE and western blotting. The electrophoretic profiles of zoospores from 13 isolates of D. congolensis were similar but not identical when stained with Coomassie blue or silver. Immunodominant polypeptides with apparent molecular masses of 76 and 31 kDa were identified in western blots of 13 of 13 and 12 of 13 isolates respectively of D. congolensis reacted with hyperimmune, ovine, antizoospore sera. Identical immunodominant polypeptides were observed in western blots reacted with sera obtained from naturally infected sheep. Initial characterisation of the 76 and 31 kDa polypeptides indicated that they were probably surface exposed because (i) antibodies eluted from the surface of live zoospores after adsorption of hyperimmune antizoospore serum, reacted principally against the 76 and 31 kDa subunit polypeptides in western blots, (ii) adsorption of hyperimmune antizoospore serum with live zoospores resulted in significant diminution of reactivity against both the 76 and 31 kDa polypeptides in western blots, (iii) indirect fluorescent immunostaining of zoospores with antiserum prepared against gel-purified 76 kDa polypeptide, resulted in intense staining of the zoospore outer coat. Immuno-gold electron microscopy of negatively stained zoospores with antiserum prepared against gel-purified 31 kDa polypeptide identified this antigen as a flagella subunit. 相似文献
18.
Kaya O Kirkan S Unal B 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2000,47(2):155-157
Dermatophilus congolensis was isolated from a cat with dermatitis. The isolate was sensitive to oxytetracyclin, streptomycin and penicillin but resistant to ampicillin, amoxicillin, gentamycin and cefoperazone. 相似文献
19.
Survival of Dermatophilus congolensis in tropical clay soils submitted to different water potentials. 总被引：1，自引：0，他引：1
The survival of a rifampicin-resistant mutant of Dermatophilus congolensis in vertisol and oxisol soils from Guadeloupe and in their constitutive clays was studied using a pneumatic device for controlling water potentials (pF). Experiments were carried out at two pF values simulating the wet season and the dry season. Survival time depended on the type of soil and its water content. Organic matter had a protective effect on the microorganism in oxisol but not in vertisol. The pathogenicity of D. congolensis was preserved in the soils which could therefore act as temporary reservoirs of this pathogen. Long-term survival of this organism in soils mixed with water suggests that ponds and dipping tanks may constitute sources of infection for cattle. 相似文献
20.
Three antigens prepared from different phases of the life cycle of Dermatophilus congolensis were used in an enzyme-linked immunosorbent assay to measure serum and skin surface antibody responses in sheep after a first, second and third inoculation with D. congolensis. After the first inoculation, a strong antibody response to the flagella, filament and soluble antigens was detected after 7-21 days in the sera from sheep that were regularly biopsied; the antibody response at the skin surface was detected 28-42 days after inoculation, when the lesions were resolving. Strong anamnestic responses were detected in the serum of sheep that were biopsied and some of the nonbiopsied sheep after the second and third inoculations, but the skin surface antibody response at these times was variable. 相似文献