First isolation of Campylobacter jejuni from the vaginal discharge of three bitches after abortion in South Africa.

Campylobacter jejuni was isolated in pure culture from the vaginal discharge from three German Shepherd bitches after late-pregnancy abortions. The main clinical sign occurring in the bitches was a profuse and odourless haemorrhagic vaginal discharge.

The antibiotic sensitivity patterns of Bacillus anthracis isolated from the Kruger National Park.

Forty-four isolates of Bacillus anthracis made from carcasses and soil in different localities of an endemic anthrax area in the Kruger National Park, South Africa, were tested by standard disc diffusion for their susceptibility to 18 different antibiotics. These were ampicillin, penicillin G, sulphatriad, streptomycin, clindamycin, gentamicin, fusidic acid, trimethoprim, sulphamethoxazole, chloramphenicol, erythromycin, methicillin, tetracycline (2 different concentrations), novobiocin, cefotaxime, netilmicin, cefamandole and cefoxitin. All the isolates were susceptible to ampicillin, streptomycin, chloramphenicol, erythromycin, tetracycline, methicillin and netilmicin. More than 90% of the isolates were sensitive to clindamycin, gentamicin and cefoxitin, whereas only 84.1% of the isolates were sensitive to penicillin G, 86.4% to novobiocin and 68.18% to cefamandole. Complete resistance in 100% of the isolates was encountered with trimethoprim and sulphamethoxazole, with 95.45% for sulphatriad. Moderate sensitivity occurred with penicillin G (15.9% of the isolates), clindamycin (6.8%), novobiocin (13.6%), fusidic acid (84.1%), cefotaxime (100%), cefamandole (31.8%) and cefoxitin (6.8%). The relevance of the findings to the therapeutic uses of different types of antibiotic in human clinical cases referred to in the literature is discussed.

The biochemical, morphological and virulence profiles of Bacillus anthracis isolated in the Kruger National Park.

The biochemical, morphological and virulence profiles of 44 Bacillus anthracis isolates, obtained from various localities and carcass remains of wild animals in the Kruger National Park, South Africa, were examined. The morphological characteristics tested for included: the formation of capsules on bicarbonate agar, the motility of the vegetative organism, the presence of haemolysis on blood tryptose agar, the sensitivity of the vegetative organism to bacteriophage, the production of lecithinase on egg yolk agar, the liquefaction (hydrolysis) of gelatine and the capability of each isolate to produce mucoid colonies when grown on bicarbonate agar with horse serum in an atmosphere containing CO2. The API 50CHB and 20E systems were used to evaluate the biochemical activity of each isolate. The virulence of each isolate was determined by its LD50, using an inbred line of Balb/C mice. A clear pattern in the biochemical reactions emerged that appeared to be specific for each isolate. On the API 50CHB test strip, only 2 of the 44 isolates gave a 100% positive reaction to all 10 of the biochemical substances to which it was supposed to react, 9 gave positive results to 90%, 19 were positive to 80%, and 14 were positive to 70%. The reactions on the API 20E were completely different from what was expected, with only 1 of the biochemical activities (gelatinase production) showing a positive reaction to all the isolates. The virulence test indicated that 27/44 isolates could be regarded as highly virulent with a LD50 of less than 1,000 organisms, and the rest of the isolates as virulent with a LD 50 of 1,001-10,000 organisms.(ABSTRACT TRUNCATED AT 250 WORDS)

The isolation and serology of the "FSA" Brucella melitensis Rev. 1 mutant in a flock of sheep.

A flock of sheep, known to be infected with the "FSA" mutant of Brucella melitensis Rev. 1, was examined serologically and bacteriologically to determine whether any relationship existed which would help in the control of this infection in the field. An attempt was also made to determine whether vertical transmission occurred. Twenty-one out of 62 sheep were bacteriologically positive. The best organs for isolation were the udder, supramammary lymphnodes and uterus. No significant relationship could be shown between the complement fixation test and bacterial isolation. The absence of any relationship between serological and bacteriological results agrees with a short-lived infection. None of the 24 lambs sacrificed at 5 months showed either serological reactions or were bacteriologically positive, thus no vertical transmission could be shown.

The characteristics of a variant strain of Brucella melitensis Rev 1.

Circumstantial evidence is presented for the occurrence of a variant of a vaccine strain of B. melitensis Rev 1, designated "FSA" (foreign South African). FSA resembles Rev 1 in its reactions to penicillin and streptomycin but reacts closer to a field strain of B. melitensis as regards dye (thionine and basic fuchsin) sensitivity and colony size. Although colonies of Rev 1 were consistently smaller than other B. melitensis strains, their size was 0,75 mm as opposed to the 1-2 mm reported in the literature, while B. melitensis 16M colonies were 1,25-1,5 mm as opposed to the 3-4 mm previously reported. Rev 1 was found to be urease positive, unless a test of low sensitivity was applied.

The use of meso-erythritol sensitivity discs in the typing of Brucella strains.

Sensitivity discs containing 1 and 2 mg meso-erythritol were found to give comparable results to the use of meso-erythritol incorporated into growth medium at 1 and 2 mg/ml. The discs proved easy and efficient when used in a disc ring together with benzyl penicillin and streptomycin sulphate discs.

Brucellosis serology: reduced dose S19 vaccination of yearling heifers versus the use of the standard dose at 5-7 months of age in a clean herd.

In the 427 heifers vaccinated at 12 to 14 months of age with the reduced dose (3 X 10(8) to 1 X 10(9) viable organisms per dose) 3 had antibody titres in the complement fixation test of 196, 688 and 748 IU ml-1, respectively, at 5 months post-inoculation. At 23 to 25 months of age 8/128 (6.3%) of these heifers had rose bengal test (RBT) reactions, at least 6/128 (4.7%) a serum agglutination test (SAT) antibody titre in excess of 30 IU ml-1 and 1/128 had a suspicious reaction in the complement fixation test (CFT) of 30 to 49 IU ml-1. In the 116 heifers inoculated with the standard dose (4 to 12 X 10(10) viable organisms) at 5 to 7 months of age and tested at 22 to 24 months of age, a reactor rate of 37/116 (31.9%) in the RBT was seen. At least 34/116 (29.3%) had antibody titres in excess of 30 IU ml-1 in the SAT. Only 1 animal had a suspicious reaction in the CFT of 18 to 24 IU ml-1. No abortions could be attributed to the vaccine strain and no other isolates of the vaccine strain were made. The possible role of vaccine residues in syringes as a cause of persistent reactions is discussed. The use of disposable syringes is recommended. On serological grounds there appears to be little advantage in using the reduced dose vaccine in yearling heifers as opposed to the standard dose vaccination of 5 to 7 month old heifers.

The reproducibility of results in bovine brucellosis serology and their correlation with the isolation of Brucella abortus.

In both the complement fixation test (CFT) and the serum agglutination test (SAT) titres were reproducible for the most part within a twofold range. They seldom exceeded these limits and never a fourfold range. Brucella abortus was successfully isolated in 86% of serologically positive cases and evidence is presented to confirm the use of the 30 International Units/ml level in the CFT as being diagnostically significant. The SAT, when done in microtitration plates, is even more reproducible than when done in tubes. The incidence of infected animals aborting or calving down with negative titres was found to be low.

The relationship between the minimal and the 50% haemolytic dose in complement titrations.

The 50% spectrophotometric complement titration end-point (C'H50) was found to be more reproducible than the 100% end-point. The relationship of the 100% end-point (MHD) to the (C'H50) was 1:2, 5. The use of thrombin tubes induced clotting within 2 min and enabled the process of complement preparation to be completed well within 1 hour.