The intricacies of the serological grouping of streptococci are discussed. The pathogenicity and accurate classification of streptococci isolated from arthritic porcine joints were in doubt. Pure cultures of these isolates were inoculated intravenously into healthy pigs to ascertain their pathogenicity and in an attempt to fulfil Koch's postulates. The pathogenesis of streptococcal arthritis in swine is discussed. On intravenous inoculation into experimental pigs the streptococcal isolates showed varying degrees of pathogenicity and arthritogenesis.
Recent advances in the epidemiology and life cycle of toxoplasmosis are reviewed. Cats play a key role. Toxoplasma has a coccidian-type entero-epithelial cycle with oocyst prodlction in the feline host. An extra-intestinal cycle occurs in both feline and non-feline hosts. The worldwide distribution and the public health significance of toxoplasmosis as a zoonosis is discussed, with particular reference to available data regarding Southern Africa.
Joints obtained from 192 pig carcases were examined by means of standard microbiological and macro- and histopathological procedures. Approximately 32% of the joints were considered normal; 35.5% showed lesions consistent with osteochondrosis and a non-specific synovitis was present in 24.4%. Only 6.1% of joints were arthritic and yielded either Staphylococcus aureus or Streptococcus spp. The remainder (2.3%) had periarticular lesions such as abscesses. The study emphasises that an accurate diagnosis and correct evaluation of pig carcases showing joint lesions, is absolutely essential if a high standard of meat inspection is to be obtained and unnecessary economic losses are to be avoided.
This is the first known isolation in the Republic of South Africa (RSA) of the serovar pomona from the organs of porcine foetuses as well as from the renal lymph nodes of slaughter pigs showing chronic nephritis. In addition, the serovar pomona was isolated from the kidneys of 87.5% of the slaughter pigs examined. The success of these isolations was attributed in part to the refining of 2 existing isolation techniques which complement each other. Using the microscopic agglutination test, serum samples taken from the same farming unit showed evidence of antibodies to the serovar pomona in 89 out of the 170 bovines (52%), 9 out of the 52 porcines (17%), 2 of the 2 canines (100%), 5 out of the 13 equines (38%) and 2 out of the 152 ovines (1%) that were tested. As far as is known, serological evidence of the serovar pomona in porcines, ovines, equines and canines has never previously been published in the RSA.
Some aspects of the pathogenesis and comparative pathology of toxoplasmosis are described. The general pattern of infection, with or without necrosis, and tissue cyst formation as it occurs in all species is dealt with. The wide pathological manifestations of toxoplasmosis as seen in sheep, cattle, pigs, horses, dogs, cats, chinchillas and man are reviewed.
Arthritic joints obtained from 50 freshly slaughtered pig carcasses condemned for polyarthritis were studied microbiologically. A routine technique was developed for aseptically opening joints to obtain material for microbiological examination. A standard series of culture media for the primary isolation of arthritogenic agents were used in the examination of each affected joint. The microbiological study cultured for isolation of the following microorganisms: Erysipelothrix rhusiopathiae, Corynebacterium pyogenes, Staphylococcus aureus, Escherichia coli, Streptococcus spp., Haemophilus spp., Mycoplasma spp., Salmonella spp., Chlamydia, and viruses.E. rhusiopathiae was found to be responsible for 48% of the cases of arthritis and Streptococcus spp., C. pyogenes and S. aureus for 20%, 4%, and 2% respectively; no microorganisms were cultured from 26% of the arthritic joints.
The lymph drainage of the major joints of the porcine forelimb was subjected to a critical examination. Commercial India ink was injected into the left elbow joint and right shoulder joint of an experimental pig. The shoulder joint was approached craniolaterally, the injection site being at the cranial border of the tendon of insertion of the infraspinatus muscle. The elbow joint was approached from the dorsolateral aspect. A suitable site for intra-articular injection into the elbow joint was found to be within an imaginary triangle formed caudal to the lateral epicondyloid crest of the humerus, the ventral border of the lateral head of the M. triceps brachii, and a line just dorsal to the olecranon. The lymph nodes of the neck and shoulder region were carefully exposed and examined for any discoloration due to the ink. The dissection of the lymph vessels and lymph nodes showed that the Lnn, axillares primae costae drained the elbow and shoulder joint after the intra-articular injection of India ink.