First Report of Puccinia thaliae on Canna Lily in South Africa.

Canna indica L., known as Indian shot or canna lily, occurs throughout the New World in tropical and subtropical areas. This upright, perennial, rhizomatous herb is a popular garden plant in South Africa because of its spectacular plant habit and growth vigor. During January 2005, canna lily leaves with rust symptoms were collected from Pietermaritzburg in the province of KwaZulu-Natal. Orange-yellow uredinia were observed primarily on the abaxial surfaces, often covering the entire leaf with coalescing pustules. Koch's postulates were completed in repeated tests with spray inoculations of blooming potted plants, urediniospores suspended in water (42 × 104 spores/ml), incubation in a dew chamber for 14 h at 20°C in the dark, and then returned to the greenhouse. Symptoms similar to those of the original collection formed 10 days postinoculation. Only the uredinial stage was observed, which was characterized by hypophyllous, yellow-brown, subepidermal, erumpent, and irregular shaped uredinia. The urediniospores were round to ovoid, orange-yellow, echinulate, and 25 to 35 × 15 to 20 µm. The pathogen was identified as Puccinia thaliae Diet. according to its description on Canna edulis Ker-Gawl. (1). Following the report of P. thaliae on C. indica in Hawaii in 1989 (2), to our knowledge, this is the first description of canna lily rust in South Africa. References: (1) M. L. Jeeva et al. Plant Pathol. 53:261, 2004. (2) D. E. Gardner and C. S. Hodges. Pac. Sci. 43:4155, 1989.

Claviceps cyperi, a new cause of severe ergotism in dairy cattle consuming maize silage and teff hay contaminated with ergotised Cyperus esculentus (nut sedge) on the Highveld of South Africa.

During December/January 1996/97 typical summer syndrome (hyperthermia and a 30% drop in milk yield) occurred in succession in two Holstein dairy herds (n=240 and n=150 milking cows, respectively) on the South African Highveld. These farms are situated in the midst of the prime maize and dairy farming areas of South Africa where this condition had never been diagnosed before. The individual components of the concentrate on both farms were negative for ergot alkaloids. Endophytic fungi and/or ergot infestation of teff and other grasses fed to the cows were then suspected of being involved, but neither endophytes nor ergot alkaloids could be implicated from these sources. By measuring the serum prolactin levels of groups of sheep (n=5) fed the first farm's total mixed ration (TMR) or its three individual fibre components for a period of 11 days, the source of the ergot alkaloids was identified. A statistically significant decrease in the level of this hormone occurred only in the group on maize silage (which constituted 28% on dry matter base of the TMR). The involvement of the maize silage was further chemically confirmed by the high levels of total ergot alkaloids, predominantly ergocryptine, found by LC-MS in the silage as well as in the TMR (115-975 ppb and 65-300 ppb, respectively). The ergot alkaloid content (mainly ergocryptine) of the maize silage on the second affected farm was 875 ppb. Withdrawal of contaminated silage resulted in gradual recovery of stock on both farms. Nut sedge (Cyperus esculentus and Cyperus rotundus of the family Cyperaceae) has a world-wide distribution and is a common weed in annual crops, and can be parasitized by Claviceps cyperi. Careful examination of the maize silage from both farms revealed that it was heavily contaminated with nut sedge and that it contained minute sclerotia, identified as those of Claviceps cyperi, originating from the latter. Nut sedge was abundant on both farms and it is believed that late seasonal rain had resulted in mature, heavily ergotised nut sedge being cut with the silage. Claviceps cyperi sclerotia, collected on the affected fields in the following autumn contained 3600-4000 ppm ergocryptine. That the dominant alkaloid produced by this particular fungus was indeed ergocryptine, was confirmed by negative ion chemical ionization MS/MS. In one further outbreak in another Holstein herd, teff hay contaminated with ergotised nut sedge and containing 1200 ppb alkaloids, was incriminated as the cause of the condition. This is the first report of bovine ergotism not associated with the Poaceae infected with Claviceps purpureum or endophytes but with the family Cyperaceae and this particular fungal phytopathogen.

Ectopic calcification of rat aortas and kidneys is reduced with n-3 fatty acid supplementation.

Supplementation with essential fatty acids has been shown to prevent the experimentally induced ectopic calcification of the kidneys known as nephrocalcinosis. Male Sprague-Dawley rats were fed a semi-synthetic diet supplemented with different essential fatty acids while being injected for a period of 10 days with calcium glubionate. After 3 weeks their kidneys and aorta were removed and the respective calcium content measured compared to the control, saline injected animals. Lipoic acid-EPA, fish oil (EPA rich) as well as the EPA monoester reduced the calcium concentration of both the kidneys and the aorta towards control values. Lipoic-EPA was the best absorbed of the three compounds and its combination of anti-oxidant together with EPA lowered the calcium content of both the aortas and the kidneys.

Two outbreaks of type C and type D botulism in sheep and goats in south Africa.

Two outbreaks of botulism in sheep and goats are described; in one, 329 out of 900 sheep in a feedlot died within 9 d of the onset of the disease and in the other, 100 sheep and goats out of 330 succumbed over a period of about 3 weeks. Animals were found dead or died suddenly, without exhibiting clinical signs. Others stood with lowered heads and showed drooling of saliva or a stiff gait. Paresis and/or paralysis were frequent signs in the terminal stages of the disease. Gross lesions such as the accumulation of fluids in body cavities, pulmonary oedema, foam in the trachea, epicardial haemorrhages and congestion of the mucosa of the small intestine, suggestive of heart failure, were present in animals from both outbreaks. Botulism was confirmed via the mouse toxicity test, by the demonstration of Type C and Type D toxins in the feed and intestinal contents of sheep from the first outbreak and Type D toxin in intestinal contents of sheep from the second. The clinical signs and macropathology in the outbreaks of botulism in sheep and goats in South Africa may resemble "krimpsiekte" and cardiac glycoside and ionophore poisoning, as well as other conditions causing heart failure.