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1.
Non-lactating, multiparous ewes were immunized either by subcutaneous infection with live Staphylococcus aureus (seventeen ewes) or by intramuscular injections of a killed S. aureus-oil adjuvant vaccine (seventeen ewes). Polymorphs which were subsequently collected from the mammary glands of the animals were used in in vitro phagocytosis assays against Pseudomonas sp. or S. aureus. There was no difference between polymorphs from the two groups of ewes in their ability to phagocytose Pseudomonas organisms. Polymorphs from the infected ewes showed significant phagocytic superiority over cells from ewes given the killed vaccine when S. aureus was the target organism. This phagocytic superiority could be abrogated by removal of cytophilic immunoglobulin from polymorphs and restored by replacement of cytophilic immunoglobulin. It was shown by staining polymorphs with FITC-conjugated anti-immunoglobulin sera that cytophilic immunoglobulin on the surface of polymorphs belonged to the IgG2 class of immunoglobulins. When 'neutral' polymorphs (from non-immunized ewes) were coated with IgG2 purified from the sera of infected ewes, they exhibited enhanced phagocytosis of staphylococci compared with 'neutral' polymorphs carying IgG2 from the sera of ewes given the killed vaccine.  相似文献   

2.
A total of 447 micrococcaceae strains isolated from 88 ewe and 359 goat milk samples from cases of chronic mastitis were differentiated by means of the ATB 32 STAPH-test. Of these strains 389 (= 87%) could be identified. Fourteen strains were sensitive in the bacitracin-resistance-test and therefore classified as Micrococcus spp. In ewe milk following Staphylococcus spp. were found: S. epidermidis, S. aureus, S. lentus, S. xylosus, S. warneri, S. equorum, S. haemolyticus, S. simulans, S. hominis and S. saprophyticus. Staphylococcus spp. identified in goat milk samples were: S. epidermidis, S. aureus, S. caprae, S. lentus, S. simulans, S. capitis, S. lugdunensis, S. xylosus, S. chromogenes, S. hominis, S. arlettae, S. warneri, S. sciuri, and S. saprophyticus. Highest cell counts in the milk of both animals species, and the highest incidence of clinical udder alterations were caused by S. aureus. Increases in milk cell counts as well as pathological udder findings were observed in coagulase-negative staphylococcal infections for novobiocin-sensitive Staphylococcus spp. (S. epidermidis, S. warneri, S. simulans, S. lugdunensis, and S. chromogenes) and several S. lentus strains.  相似文献   

3.
A lyophilised chlamydial vaccine was prepared from the 1B temperature-sensitive strain of ovine Chlamydia psittaci. Ewes inoculated with a low titre of the live vaccine four weeks before artificial insemination were challenged on day 70 of gestation with five UK field isolates of C psittaci, including strains A22 and S26/3 previously incorporated into a commercial inactivated vaccine. There was a significantly lower chlamydial abortion rate after challenge in the vaccinated group (7.1 per cent) than in the unvaccinated group (80 per cent). All the lambs born to the vaccinated ewes were viable and of good quality. The vaccine also reduced the number of infected ewes in the group and the severity of the infection. The compatibility of the chlamydial vaccine and a toxoplasma vaccine was also tested. The abortion rate of ewes vaccinated with the two vaccines at separate injection sites (16 per cent) was less than that of ewes vaccinated with both vaccines at one site (32 per cent).  相似文献   

4.
Mastitis was induced by injection of cell walls of Staphylococcus aureus into the mammary glands of normal cows and of cows which had been vaccinated parenterally with a staphylococcal bacterin in adjuvant. Multiplication of S aureus in normal milk and in mastitic milk from vaccinated and nonvaccinated cows was determined in constant volume cultures. Growth was significantly inhibited during the 1st 6 hours of incubation, regardless of the nature of the milk or the vaccination status of the cows. Growth was inhibited for 24 hours in normal milk, and the organisms grew exponentially in mastitic milk regardless of the vaccination status of the cows.  相似文献   

5.
A stock strain of Staphylococcus aureus of mastitis origin, characterized by alpha-, beta-, and delta-toxins, was used to produce chronic mastitis of 20 to 300 days' duration in 6 lactating mammary quarters of 4 cows. Early acute Streptococcus agalactiae mastitis was produced in 1 additional mammary quarter of 1 cow. Equine anti-bovine leukocyte serum (EABLS) was administered to all cows by continuous intravascular drip for 12 to 32 hours. Neutropenia in blood and partial depletion of neutrophil reserve in bone marrow were produced. Chronic subclinical staphylococcal mastitis in 2 quarters of 1 cow changed to gangrenous mastitis by the 40th hour after EABLS administration and led to death of the cow. The disappearance of neutrophil leukocytes from the milk was followed by uninhibited multiplication of S aureus. Probably, staphylococcal leukocidins accelerated the destruction of neutrophils in the milk as S aureus multiplication became intensified. In another quarter of the same cow that was infected with Str agalactiae, neutrophil leukocytes were present in milk as long as 3 days after their disappearance from blood and bone marrow. This may give some indication of the extravascular life-span of the neutrophil in the udder in mastitis. The 2nd cow died at the 16th hour from the start of EABLS administration and at a time when gangrenous mastitis was in the initial stages of development. The S aureus-infected quarters of the 2 remaining cows did not become gangrenous. Administration of EABLS to these 2 cows did not significantly reduce the numbers of neutrophil leukocytes entering the milk of the 3 S aureus-infected quarters. It is concluded that continuous diapedesis of neutrophil leukocytes into the milk in chronic staphylococcal mastitis protects the gland against the development of gangrenous mastitis in the presence of a strain of S aureus capable of alpha-toxin production.  相似文献   

6.
To investigate the role of macrophages in the induction of the production of antibody to staphylococcal antigens, we used Cl2MDP (clodronate) liposomes as a tool for local macrophage depletion. Macrophage depletion caused in mice by intraperitoneal (i.p.) injection of Cl2MDP liposomes was associated with a reduction in the clearance of Staphylococcus aureus Cowan 1 bacteria from the tissues of infected animals and with a marked decrease in the bactericidal activity of macrophages escaping from the lethal effect of clodronate. Despite the functional defect of macrophages, the mice treated with Cl2MDP liposomes two days before the injection of alpha-toxin (toxoid) or whole heat-killed S. aureus Cowan 1 bacteria, demonstrated an enhancement in the production of anti-staphylococcal alpha-toxin IgM and anti-collagen-binding protein IgG. A similar enhancement of antistaphylococcal antibody synthesis was observed in mice after receiving phosphate buffered saline (PBS) encapsulated in liposomes.  相似文献   

7.
A prototype vaccine that is being developed for the control of swine dysentery (SD) was tested in two groups of experimental pigs. Vaccination induced high circulating antibody titres against the aetiological agent, Serpulina (Treponema) hyodysenteriae. Pigs in the first trial were vaccinated twice before being challenged orally with the bacteria. Five of 6 unvaccinated animals developed dysentery within a fortnight of challenge, but only 1 of 6 vaccinated pigs showed signs of disease at this time. Unexpectedly, 1 mo after challenge, the surviving unvaccinated pig and 2 remaining healthy vaccinated animals succumbed to the disease. The reason for the development of this late-onset form of dysentery was not clear. In the second trial, 8 pigs were vaccinated 3 times. Only 2 of these animals (25%) developed severe dysentery after being mixed with infected pigs, whereas 7 of 8 (88%) unvaccinated control pigs in the same pen became diseased. The late-onset form of dysentery was not observed. The prototype vaccine for SD provided a useful level of protection, and could be used in programs to control the disease in Australia.  相似文献   

8.
9.
Three groups of dairy cows were immunized by subcutaneous (s.c.) administration of a preparation of live Streptococcus uberis (strain 0140J) and an intramammary infusion of a soluble surface extract derived from same the bacteria. Animals in Groups 1 and 2 received two s.c. vaccinations plus an intramammary inoculation. Animals in Group 3 received two s.c. vaccinations but did not receive the intramammary infusion. In addition to the vaccinated animals, each group also contained two non-vaccinated (control) animals. All animals were challenged experimentally by intramammary infusion (in two quarters per animal) of ca 100 c.f.u. of S. uberis (strain 0140J or C221) and monitored for clinical signs of disease, bacterial numbers in milk, somatic cell count in milk, and daily milk yield for the following 10 days. Animals in Group I were challenged with strain 0140J. Only one out of six challenged quarters of three vaccinated cows developed clinical disease compared to all (four out of four) quarters of non-vaccinated cows. Animals in Group 2 were challenged with strain C221. All challenged quarters of three vaccinated (six out of six) and two non-vaccinated (four out of four) cows developed clinical mastitis. Animals in Group 3 were challenged with strain 0140J. Five out of eight quarters on four vaccinated cows developed clinical mastitis but the onset was delayed in comparison with that in both non-vaccinated cows in which four out of four challenged quarters developed clinical mastitis. These results indicated that vaccination with live S. uberis protects against challenge with the homologous strain but was less effective against a heterologous strain. Reduced protection was also seen when the intramammary booster was omitted.  相似文献   

10.
A total of 168 coagulase-negative staphylococci (CNS) strains were isolated from milk samples taken from cows with clinical mastitis. The samples were collected between January 1990 and August 1992 from cows in the veterinary surveillance area of the Ambulatory Clinic, College of Veterinary Medicine, Hautj?rvi, Finland. In 100 cases the effect of antibiotic treatment was evaluated 3-4 weeks after initial sampling. Clinical symptoms of the animals were recorded, and the inflammatory status of their udders was evaluated using the CMT test and assessing milk NAGase activity. CNS mastitis was most common in young cows during early lactation. Staphylococcus hyicus, S. simulans and S. epidermidis were the most frequently isolated CNS. Clinical symptoms were most severe with S. hyicus. Cure rates for CNS induced mastitis were high.  相似文献   

11.
A total of 71 Staphylococcus aureus strains isolated from bovine mammary glands were identified and subtyped. The methods used to differentiate between the S. aureus isolates were the DNA polymorphism pattern after amplification with a Polymerase Chain Reaction using several primer combinations and phage typing. The DNA fingerprinting technique using RAPD, ERIC1R and ERIC primers proved to be useful in differentiating isolates of S. aureus. Differentiation of isolates using phage typing gave no additional information compared to the DNA technique. The outbreak of S. aureus in the herd studied was mainly caused by one S. aureus strain. Other strains were only found on three occasions, twice in subclinical infections and once from a case of clinical mastitis. In the latter case the dominant strain was isolated from a different quarter of the same cow. Four of the ten cows studied suffered from clinical mastitis. From those four cows, three remained infected with the same S. aureus strain despite antibiotic treatment.  相似文献   

12.
Enterotoxin production by Staphylococcus species other than Staphylococcus aureus has been reported. Staphylococcus strains (104 in toto) representing twelve species and subspecies were examined for enterotoxins using a commercial staphylococcal enterotoxin ELISA immunoassay (TECRA, International Bioproducts). Staphylococcus intermedius (24 strains) and S. aureus (7 strains) were positive with this test. Western blots of S. aureus exoproteins demonstrated proteins of approximately 30 kD, consistent with known staphylococcal enterotoxins. The major antigen in all S. intermedius strains, a 75 kD protein, was not analogous to previously described staphylococcal enterotoxins. This protein was unique to S. intermedius. Gel filtration data indicate that the protein is a subunit of a larger protein in vivo. The 75 kD protein cross-reacts with several enterotoxin antibodies. It is unclear whether the protein is a toxin, but its homology with S. aureus enterotoxins may indicate a shared toxic region, or this protein may create false positive results in screening for enterotoxin.  相似文献   

13.
Staphylococcus aureus and Staphylococcus epidermidis both recognize and bind the human iron-transporting glycoprotein, transferrin, via a 42-kDa cell surface protein receptor. In an iron-deficient medium, staphylococcal growth can be promoted by the addition of human diferric transferrin but not human apotransferrin. To determine whether the staphylococcal transferrin receptor is involved in the removal of iron from transferrin, we employed 6 M urea-polyacrylamide gel electrophoresis, which separates human transferrin into four forms (diferric, monoferric N-lobe, and monoferric C-lobe transferrin and apotransferrin). S. aureus and S. epidermidis but not Staphylococcus saprophyticus (which lacks the transferrin receptor) converted diferric human transferrin into its apotransferrin form within 30 min. During conversion, iron was removed sequentially from the N lobe and then from the C lobe. Metabolic poisons such as sodium azide and nigericin inhibited the release of iron from human transferrin, indicating that it is an energy-requiring process. To demonstrate that this process is receptor rather than siderophore mediated, we incubated (i) washed staphylococcal cells and (ii) the staphylococcal siderophore, staphyloferrin A, with porcine transferrin, a transferrin species which does not bind to the staphylococcal receptor. While staphyloferrin A removed iron from both human and porcine transferrins, neither S. aureus nor S. epidermidis cells could promote the release of iron from porcine transferrin. In competition binding assays, both native and recombinant N-lobe fragments of human transferrin as well as a naturally occurring human transferrin variant with a mutation in the C-lobe blocked binding of 125I-labelled transferrin. Furthermore, the staphylococci removed iron efficiently from the iron-loaded N-lobe fragment of human transferrin. These data demonstrate that the staphylococci efficiently remove iron from transferrin via a receptor-mediated process and provide evidence to suggest that there is a primary receptor recognition site on the N-lobe of human transferrin.  相似文献   

14.
A total of 175 strains of Staphylococcus aureus and 67 strains of Staphylococcus epidermidis were studied, isolated from 486 samples of milk secretion taken aceptically from the individual quarters of the udder of cows affected with subclinical and purulent (clinical) mastitis. The staphylococci were referred to as the causative agent of mastitis in case they were the only microflora in the seedings of the investigated material. Tests were applied as given in Fig. 1 to characterize the strains. It was found that mastitis in cows could be due to both plasma coagulating staphylococci (Staphylococcus aureus) and coagulase-negative Staphylococcus epidermidis organisms. The two Staphylococcus species were isolated from cows with clinical and subclinical mastitis. The division between pathogenic and nonpathogenic Staphylococcus strains by the plasma-coagulating symptom proved impossible, and this made it necessary to use other tests for pathogenicity. It became evident that the thing Staph. aureus and Staph. epidermidis had in common when isolated from cows with mastitis was the production of a gold-like pigment and delta hemolysin. Similarly to Staph. aureus isolated animals, the bovine Staph. epidermidis organisms did not possess fibrinolysin and rarely produced hemolysin. The isolated organisms belonging to the coagulase-positive staphylococci corresponded by their basic properties to Staphylococcus aureus var. bovis as described in the literature. The cultures of Staphylococcus epidermidis isolated under similar conditions showed in a considerable per cent of the cases somewhat different behaviour.  相似文献   

15.
Specific serum activity levels against four reference strains of foot-and-mouth disease virus (FMDV) were evaluated from 1634 animals vaccinated with commercial quadrivalent oil vaccines and from 746 unvaccinated, naive animals, using the liquid-phase blocking sandwich ELISA (lpELISA) test. Cows from the FMDV-free area of Argentina were tested for the absence of specific FMDV antibodies (sp FMDV Abs) and those showing lpELISA titres < 1.0 were grouped in lots of 16 animals. They were vaccinated and challenged at 90 days postvaccination (DPV) with one of four virus strains used for vaccine production and control (prototype strains). Serum samples from vaccinated and control cattle were collected 60 and 90 DPV and the level of sp FMDV Abs was determined by lpELISA. Animals were examined for clinical signs of disease. Results show that serum lpELISA titre levels directly correlate with the percentage of protected animals. It was seen that 100, 98, 93 and 87% of the vaccinated cattle with antibody titre levels > or = 2.1 were protected against challenge with serotypes C85, A87,01 Cas and A79, respectively. Evidence is also presented of seroconversion in a sample of 3-5-month-old calves vaccinated in the field, showing lpELISA titres compatible with protection against the four vaccine viruses as long as 150 DPV. Results reported in this paper strongly support the use of the lpELISA test for a rapid and reliable evaluation of the efficacy of FMDV commercial vaccines as well as for the assessment of the immunological status of cattle in FMDV-free and enzootic regions of South America.  相似文献   

16.
17.
OBJECTIVE: To identify the Staphylococcus aureus capsular serotypes that are not typable, using capsular serotypes 5 and 8, which are currently used to type S aureus isolated from cows with mastitis. SAMPLE POPULATION: Milk samples (n = 273) from cows with mastitis in 178 dairy herds in California, Wisconsin, Michigan, Texas, and New York that were collected by state diagnostic laboratories and S aureus-positive milk samples collected by Veterinary Health Services in the United Kingdom (15), France (22), The Netherlands (36), and Germany (21). PROCEDURE: Capsular serotyping of coded isolates was performed by use of direct cell agglutination and immunoprecipitation of cell extracts with antisera specific for capsular types 5 and 8 and a newly developed S aureus serotyping antiserum 336. RESULTS: In the United States, S aureus capsular types 5 and 8 accounted for 18 and 23% of the isolates, respectively, and type 336 accounted for 59%. Percentage of capsular serotypes in European samples were as follows: type 5 = 34%, type 8 = 34%, type 336 = 30%, and nontypable = 2%. CONCLUSIONS: Serotypes 5 and 8 accounted for only 41% of S aureus isolates from US milk samples, but accounted for 70% of isolates from European milk samples. Addition of the newly developed serotyping antiserum 336 to the typing scheme accounted for 100% of US samples and 98% of European samples and will enable development of a more comprehensive S aureus vaccine.  相似文献   

18.
We investigated a possible mechanism by which immunization against core and lipid A determinants of lipopolysaccharide reduced clinical cases of mastitis and symptoms commonly associated with heterologous Gram-negative IMI. The IgG fraction of sera from cows immunized with either Escherichia coli J5 bacterin, E. coli J5 lipopolysaccharide conjugate vaccine, or unimmunized controls was purified by precipitation with caprylic acid and ammonium sulfate. The degree of IgG crossreactivity with Gram-negative bacteria that were isolated from clinical quarters was greater than that with Gram-positive isolates of Staphylococcus aureus. The highest magnitude of crossreactivity was against smooth strain E. coli isolates, followed by heterologous species of Enterobacter, Serratia, and Klebsiella isolates. Serum IgG from cows immunized with conjugate was highly crossreactive to E. coli J5, E. coli O111:B4, Serratia marcescens, Klebsiella pneumoniae, and Salmonella typhimurium lipopolysaccharides. The magnitude of antibody crossreactivity with lipopolysaccharides coincided with the ability of IgG to suppress the mitogenic effect of lipopolysaccharides on bovine lymphocytes.  相似文献   

19.
The aim of this study was to investigate the influence of iron present in the growth medium of Staphylococcus aureus on the bacterial adhesion to collagen. The experiments were extended to determinate the siderophore production and to examine the S. aureus isolates surface hydrophobicity. The addition of iron to metal deficient defined medium causes the change in hydrophobicity of the examined S. aureus strains surfaces from hydrophilic to hydrophobic. The presence of iron in staphylococcal growth medium alters also the adhesion to the surface covered with collagen. Four out of six S. aureus strains adhere to collagen weaker when cells come from iron-rich medium. Majority of tested strains produce markedly less of siderophores in media containing the excess of iron (1 and 10 microM Fe) and there is no staphylococcal siderophore activity in the growth medium with a very high concentration of this compound (120 microM Fe). The obtained results indicate that the iron-stressed conditions influence the staphylococcal adhesion to collagen.  相似文献   

20.
Two experiments were conducted to test the efficacy of a novel infectious bursal disease virus (IBDV) vaccine in broiler chickens with maternal IBDV immunity. The IBDV vaccine was formulated by mixing IBDV strain 2512 with bursal disease antibodies (BDA) to produce the IBDV-BDA complex vaccine. In Expt. I, 1-day-old Cobb x Cobb broiler chickens were vaccinated subcutaneously with either IBDV-BDA or commercial live intermediate IBDV vaccine (vaccine A) or were left unvaccinated. In Expt. 2, the vaccine A group was not included; instead, IBDV strain 2512 was included. Chickens were maintained in isolation houses. On day 28 (Expt. 1) and day 32 (Expt. 2) of age, chickens from each group were challenged with a standard USDA IBDV (STC strain) challenge. Challenged and unchallenged chickens were evaluated for their bursa/body weight ratios and antibody titers 3 days post-challenge. Bursae collected from Expt. 2 were examined histologically to evaluate bursal lesions and confirm gross examination. None of the unvaccinated chickens was protected against the challenge virus as evidenced by the presence of acute bursal lesions (edema/hemorrhage). All chickens receiving the IBDV-BDA complex or the IBDV strain 2512 (Expt. 2) were protected from the challenge virus as evidenced by no acute bursal lesions. Additionally, chickens receiving the IBDV-BDA complex vaccine or the IBDV strain 2512 had antibody titers to IBDV, indication the presence of an active immune response. In Expt. 1, chickens vaccinated with vaccine A and challenged had bursal lesions similar to those observed in the unvaccinated, challenged chickens. These chickens also showed no indication of active immunity against the virus. These results suggest that the 1-day-of-age-administered IBDV-BDA complex vaccine can induce active immunity and protection against a standard IBDV challenge in the face of variable levels of maternal IBDV immunity.  相似文献   

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