Pathogens of veterinary importance isolated from mosquitoes and biting midges in Israel

Abstract

In a bluetongue (BT) disease project, light trappings of Culkoides were conducted in 19 localities and 39,000 biting midges were examined. BT virus type 16 was isolated in 1968 at Devora from a pool consisting mainly of Culicoides schultzei gp and C. imicola; BT virus type 4 was isolated in 1969 at Yesodot from a pool of 183 C. imicola; BT virus type 2 was isolated in 1979 at Talme El'azar from pools consisting of 2462 C. imicola; and BT virus type 6 was isolated 3 times in 1980 at Bet Dagan from pools of 204, 258 and from 143 C. imicola, respectively. In the Akabane project (1976 and 1977) 4632 Culicoides and 1867 mosquitoes from four localities were trapped and examined. An arbovirus which was not Akabane, BT or turkey meningo-encephalitis (TME) was isolated from a pool of 44 engorged Culex pipiens complex trapped in Gan Shemuel. In the Rift Valley fever project, which was conducted in 1978 and 1979 due to the presence of an epidemic in Egypt, 351 mosquitoes of four species and 7098Culicoides of 14 species were tested and none were found to harbour an arbovirus. Within the TME project more than 12,000 Culicoides and 9000 mosquitoes from 14 localities were tested. Positive isolations of TME were made from an unsorted pool of mosquitoes from Gesher haziw, an unsorted pool of 13 Culicoides from Nahalal, a pool of 223 unidentified Culicoides from Zetan and a pool of 12 engorged Cx pipiens complex from the same locality. Other pathogens which were not identified to species level were also isolated.

Implicating Culicoides Biting Midges as Vectors of Schmallenberg Virus Using Semi-Quantitative RT-PCR

“…Vector competence studies for these arboviruses are most complete for AKAV, particularly in Australia where the role of Culicoides brevitarsis in transmitting and spreading the virus has been characterized in detail [7], [8]. Incidence of AKAV in field collected Culicoides has also been studied in Israel [9], [10], the Oman [11] and the Republic of South Africa [12], where the major Afro-tropical arbovirus vector Culicoides imicola is believed to play a primary role in transmission.…”

Isolation of Bluetongue Virus from Midges of Culicoides Schultzei Complex in West Bengal, India

“…This means that midges of C. schultzei complex act as one of the BTV vectors, at least, in the state of West Bengal. Other workers have reported the presence of BTV in various species of Culicoides from different countries [4,[26][27][28]. Earlier, BTV was isolated from pooled sample of Culicoides midges, collected from the western part of India [29,30].…”

The susceptibility of Culicoides imicola and other South African livestock-associated Culicoides species to infection with bluetongue virus serotype 8

“…The susceptibility of C. imicola to a variety of strains of BTV, including an isolate of BTV-9 from Kosovo in Europe (Venter et al, 2005), has been demonstrated in the laboratory (Venter et al, 1991(Venter et al, , 1998(Venter et al, , 2006aPaweska et al, 2002). These laboratory results are supported by numerous, geographically localized, field isolations of BTV (including BTV-8), from field-collected C. imicola (Walker & Davies, 1971;Braverman et al, 1981;Mellor et al, 1984;Blackburn et al, 1985;Braverman et al, 1985;Nevill et al, 1992b;Barnard et al, 1998;Venter et al, 2006b). Susceptibility studies involving the historical reference strains of various BTV serotypes and field-collected, livestock-associated Culicoides species indicate significant differences according to the isolate used.…”