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.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

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 articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

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.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

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 articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

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 C0₂. 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 <1 000 organisms, and the rest of the isolates as virulent with a LD 50 of 1 001 - 10 000 organisms. The other morphological characteristics demonstrated the typical nature of Bacillus anthracis. Three control isolates, one being the non-capsular, avirulent toxigenic Sterne strain were included in this study.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

The characteristics of a variant strain of Brucella melitensis Rev I

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 articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

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 articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

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. This is the first documented report of abortion in bitches caused by Campylobacter jejuni in South Africa.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

The characteristics of a variant strain of Brucella melitensis Rev l

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 characteristics of a variant strain of Brucella melitensis\ud Rev l

Circumstantial evidence is presented for the occurrence of a variant of a vaccine strain of B. melitensis Rev\ud 1, designated "FSA"(foreign South African). FSA resembles Rev 1 in its reactions to penicillin and streptomycin\ud but reacts closer to a field strain of B. melitensis as regards dye (thionine and basic fuchsin) sensitivity and\ud colony size.\ud \ud 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. \ud \ud Rev 1 was found to be urease positive, unless a test of low sensitivity was applied