Browsing by Author "Cristescu, Bogdan"

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    Molecular detection of tick-borne pathogens in caracals (Caracal caracal) living in human-modified landscapes of South Africa
    (2020-04-30) Viljoen, Storme; O’Riain, M J; Penzhorn, Barend L; Drouilly, Marine; Serieys, Laurel E K; Cristescu, Bogdan; Teichman, Kristine J; Bishop, Jacqueline M
    Background Wild carnivores living alongside humans and domestic animals are vulnerable to changes in the infectious disease dynamics in their populations. The aims of this study were to determine the prevalence and diversity of selected tick-borne pathogens (TBPs) of veterinary and/or zoonotic concern in wild populations of caracals (Caracal caracal) occurring in human-modified landscapes in South Africa. Using molecular techniques, we screened 57 caracal blood samples for infection by rickettsial bacteria and piroplasms in three regions of South Africa: rangeland in the Central Karoo (n = 27) and Namaqualand (n = 14) as well as the urban edge of the Cape Peninsula (n = 16) of South Africa. To characterise pathogen identity, we sequenced the 18S rRNA and 16S rRNA genes from positive samples and analysed sequences within a phylogenetic framework. We also examine the diversity of potential tick vectors. Results All individuals tested were infected with at least one tick-borne pathogen. Pathogens included Hepatozoon felis, Babesia felis, Babesia leo and a potentially novel Babesia species. An Anaplasma species previously described in South African domestic dogs was also found in 88% of urban edge caracals. Higher rates of co-infection characterised urban edge caracals (81% vs 15% and 0% in the two rangeland populations), as well as a greater incidence of mixed infections. Host attached tick species include Haemaphysalis elliptica, an important pathogen vector among carnivore hosts. Conclusions This study confirms the occurrence of previously undocumented tick-borne pathogens infecting free-ranging caracals in human-modified landscapes. We identify clear differences in the pathogen profiles among our study populations and discuss the likely health costs to caracals living adjacent to urban areas.
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    Predation impacts on livestock in a communal area of Namaqualand, Northern Cape, South Africa
    (2014) Lutchminarayan, Kirtanya; Hoffmann, Timm; Cristescu, Bogdan
    The black-backed jackal (Canis mesomelas) and caracal (Felis caracal) commonly inhabit agricultural landscapes in southern Africa, threatening goat and sheep herds. The communal area of Paulshoek, in the Northern Cape of South Africa provided a model system to study this, as farmers in this region are dependent on livestock farming as a livelihood. 47 farmers were interviewed monthly from 1998-2013, to record the number of goats and sheep lost to predators and this formed the basis of the long-term dataset. Furthermore, predation levels for each animal age class and animal condition category were investigated, and predation levels were linked to rainfall, herd size and farmer herding strategies. On-farm personal interviews with 20 of the farmers were conducted in 2014 to evaluate perceptions of predation and to gain insight into their herding strategies. It was established that 1,495 animals were reportedly lost to predators over the study period whilst an average of 3.1% of goats and 5.4% of sheep in all Paulshoek herds were lost to predators each year. Predation levels varied annually, and were linked to annual rainfall patterns. There were differences in monthly predation levels with the highest predation occurring in the late autumn- early winter months (April-June). Herd size was an important variable affecting predation as larger herds were reported as having noticeably higher predation levels than smaller herds. Younger animals were also identified as prime targets of predators whilst few older animals were lost due to predation. There were significant differences between animal condition and rainfall for the five different animal condition classes as animals in poor condition were most highly predated. Little variation in predation levels was observed within and between farmers, and the number of hours worked by farmers did not affect predation levels. Herding was recognized as an ancient practice in Paulshoek and is perceived as a means of protection of livestock from predators. This study provides valuable insight into the impacts of livestock predation in Paulshoek by investigating predator behaviour in communal areas and providing insight into farmer livelihoods, both of which could be useful for future research and communal farm management.