Formation and Structural Analysis of Novel Dibornyl Ethers

One- and two-dimensional NMR spectroscopy has been used to establish the regio- and stereochemistry of novel dibornyl ethers, obtained by acid-catalysed condensation of camphor-derived a-hydroxybornanones South African Journal of Chemistry Vol.55 2002: 111-11

Long-term follow-up of owned, free-roaming dogs in South Africa naturally exposed to Babesia rossi.

Babesia rossi is an important, tick-borne intraerythrocytic protozoan parasite; however, its natural history and epidemiology is poorly understood. Babesia rossi is the most virulent Babesia sp. in domestic dogs and is generally considered to cause severe babesiosis, which is fatal if left untreated. However, subclinical infections and mild disease from B. rossi have been reported, although the clinical progression of these cases was not reported. Therefore, to better understand B. rossi under field conditions, we evaluated its clinical progression and seroprevalence in an owned, free-roaming dog population in Zenzele, South Africa, where the parasite is endemic and prevention is not routine. The entire dog population in Zenzele was monitored intensively at the individual level from March 2008 until April 2014, primarily for a longitudinal study on rabies control. Subsequent evaluation of B. rossi comprised analyses of clinical and laboratory data collected from the Zenzele dog population during the 6 year study period. A substantial proportion (31% (n = 34)) of 109 dogs (randomly selected from every available dog in February/March 2010 older than ~6-8 weeks (n = 246)) tested by Indirect Fluorescent Antibody Test had seroconverted strongly to B. rossi. All 34 dogs were generally consistently healthy adults, determined from regular clinical examinations between March 2008 and April 2014. Blood smear examinations at multiple time points between July 2009 and February 2011 were also undertaken for almost all of these (34) seropositive dogs and all those tested were consistently negative for Babesia spp. Subclinical infections and mild disease were also the main findings for a separate group of 18 dogs positive for Babesia spp. on blood smear examination and confirmed to be infected with B. rossi by Polymerase Chain Reaction - Reverse Line Blot. Almost all of these dogs were positive at only one time point from repeat blood smear examinations between July 2009 and February 2011. We suggest that these observations are consistent with immunity acquired from repeated, low-level exposure to the parasite, generating transient subclinical infections or mild disease. Should this be the case, the use of tick control, particularly in adult dogs in free-roaming populations in B. rossi endemic regions, should be carefully considered

Why is Southern African canine babesiosis so virulent? An evolutionary perspective

<p>Abstract</p> <p>Canine babesiosis is a common, highly virulent disease in Southern Africa with even pups and juveniles being severely affected. This contrasts with bovine babesiosis, for example, where host, parasite and vector co-evolved and young animals develop immunity after infection without showing clinical signs. <it>Babesia rossi</it>, the main causative organism of canine babesiosis in sub-Saharan Africa, was first described from a side-striped jackal (<it>Canis adustus</it>) in Kenya. Although data are meagre, there is evidence that indigenous African canids, such as jackals and wild dogs (<it>Lycaon pictus</it>), can harbour the parasite without showing untoward effects. Dogs are not indigenous to Africa. The vast majority of dogs presented at veterinary facilities in South Africa represent recently introduced European, Asian or American breeds. The contention is that <it>B. rossi </it>is a new challenge to which these dogs have not adapted. With intensive treatment of clinical cases, natural selection is effectively negated and the status quo will probably be maintained indefinitely. It is postulated that <it>Babesia vogeli</it>, which frequently results in unapparent infections or mild manifestations in dogs, represents or is closely related to the ancestral form of the canine parasite, possibly originating from wolves (<it>Canis lupus</it>).</p

Evidence of new pathogenic Theileria species in dogs

Babesiosis, caused by tick-borne haematozoan organisms of the genus Babesia, is a parasitic disease of domestic and wild mammals. Canine Babesidae have historically been classified as “large Babesia” (Babesia canis) and “small Babesia” (Babesia gibsoni) based on the size of their intraerythrocytic forms. Recent publications, however, suggest that the diversity of piroplasm species infecting dogs might be greater than previously appreciated. Sequencing and phylogenetic analysis of the ssrRNA gene has revealed that canine piroplasms are found in three clades, ‘true’ Babesia sp. (B. canis and B. gibsoni), Theileria annae and Theileria-like group (B. conradae). This newly recognised piroplasm T. annae appears to be hyperendemic in northwest Spain. The vector for this emergent canine infection remains undescribed, although the Ixodeshexagonus is suspected based on their presence upon the dogs in NW Spain and the relative absence of others. These observations have introduced a major change in the approach to the epidemiology of babesiosis in dogs. More clinical samples and data will need to be collected and analyzed to understand the importance of Theileria species in dogs