Complete Life Cycle of Trypanosoma thomasbancrofti, an Avian Trypanosome Transmitted by Culicine Mosquitoes

Avian trypanosomes are cosmopolitan and common protozoan parasites of birds; nevertheless, knowledge of their life cycles and vectors remains incomplete. Mosquitoes have been confirmed as vectors of Trypanosoma culicavium and suggested as vectors of T. thomasbancrofti; however, transmission has been experimentally confirmed only for the former species. This study aims to confirm the experimental transmission of T. thomasbancrofti to birds and its localization in vectors. Culex pipiens were fed on blood using four strains of T. thomasbancrofti, isolated from vectors and avian hosts; all strains established infections, and three of them were able to develop high infection rates in mosquitoes. The infection rate of the culicine isolates was 5–28% for CUL15 and 48–81% for CUL98, 67–92% for isolate OF19 from hippoboscid fly, while the avian isolate PAS343 ranged between 48% and 92%, and heavy infections were detected in 90% of positive females. Contrary to T. culicavium, trypanosomes were localized in the hindgut, where they formed rosettes with the occurrence of free epimastigotes in the hindgut and midgut during late infections. Parasites occurred in urine droplets produced during mosquito prediuresis. Transmission to birds was achieved by the ingestion of mosquito guts containing trypanosomes and via the conjunctiva. Bird infection was proven by blood cultivation and xenodiagnosis; mature infections were present in the dissected guts of 24–26% of mosquitoes fed on infected birds. The prevalence of T. thomasbancrofti in vectors in nature and in avian populations is discussed in this paper. This study confirms the vectorial capacity of culicine mosquitoes for T. thomasbancrofti, a trypanosome related to T. avium, and suggests that prediuresis might be an effective mode of trypanosome transmission.

Investigations on Vector-Borne and Aerosol Transmission Potential of Kaeng Khoi Virus in Cave-Dwelling Wrinkle-Lipped Free-Tailed Bats (Chaerephon plicatus) in Thailand

Kaeng Khoi virus (KKV; Order: Bunyavirales, Family: Peribunyaviridae, Genus: Orthobunyavirus), is an endemic viral infection of the wrinkle-lipped free-tailed bat (Chaerephon plicatus; also known as Tadarida plicata plicata). Viral isolates from bat bugs (Family: Cimicidae) suggest vector-borne transmission, but in general little is known about the ecology of KKV and seroprevalence in the local human and animal populations. Transmission studies and a serosurvey were carried out in Kaeng Khoi cave, Saraburi province, Thailand, during 1973–1974. Experimental transmission studies were performed with bat bugs captured within the cave to determine the potential for vector-borne transmission, and sentinel laboratory mice placed inside arthropod-proof cages within the cave to assess the potential for aerosolized transmission. Antibodies to KKV were detected in roof rats (Rattus rattus) inhabiting the cave, in dogs living in the valley, and in humans. Freshly collected cimicids were positive for KKV, but the virus did not replicate in laboratory-inoculated bugs. Sentinel mice placed in Kaeng Khoi cave in open cages consistently became infected with KKV, as determined by the development of neutralizing antibodies. Mice placed in arthropod-proof cages also developed antibodies, indicating the possibility of airborne transmission of KKV.

Experimental transmission of Leishmania (Mundinia) parasites by biting midges (Diptera: Ceratopogonidae)

Leishmania parasites, causative agents of leishmaniasis, are currently divided into four subgenera: Leishmania, Viannia, Sauroleishmania and Mundinia. The recently established subgenus Mundinia has a wide geographical distribution and contains five species, three of which have the potential to infect and cause disease in humans. While the other Leishmania subgenera are transmitted exclusively by phlebotomine sand flies (Diptera: Psychodidae), natural vectors of Mundinia remain uncertain. This study investigates the potential of sand flies and biting midges of the genus Culicoides (Diptera: Ceratopogonidae) to transmit Leishmania parasites of the subgenus Mundinia. Sand flies (Phlebotomus argentipes, P. duboscqi and Lutzomyia migonei) and Culicoides biting midges (Culicoides sonorensis) were exposed to five Mundinia species through a chicken skin membrane and dissected at specific time intervals, post bloodmeal. Potentially infected insects were also allowed to feed on ear pinnae of anaesthetized BALB/c mice and the presence of Leishmania DNA was subsequently confirmed in the mice using polymerase chain reaction analyses. In C. sonorensis, all Mundinia species tested were able to establish infection at a high rate, successfully colonize the stomodeal valve and produce a higher proportion of metacyclic forms than in sand flies. Subsequently, three parasite species, L. martiniquensis, L. orientalis and L. sp. from Ghana, were transmitted to the host mouse ear by C. sonorensis bite. In contrast, transmission experiments entirely failed with P. argentipes, although colonisation of the stomodeal valve was observed for L. orientalis and L. martiniquensis and metacyclic forms of L. orientalis were recorded. This laboratory-based transmission of Mundinia species highlights that Culicoides are potential vectors of members of this ancestral subgenus of Leishmania and we suggest further studies in endemic areas to confirm their role in the lifecycles of neglected pathogens.

TRANSMISSION OF HOLOGRAPHIC INFORMATION ON A SINGLE SIDEBAND

When holographic information is transmitted through communication channels, a problem arises associated with the large capacity of holograms. In the patent of the Russian Federation No. 2707582, the possibility of compressing holographic information was shown, similar to the transmission on one sideband known in radio electronics. The experimental transmission of such compressed information over a Wi-Fi wireless communication channel with a frame rate of more than 25 frames per second is shown in this paper. The experiment of transmitting holographic information of 3D images over a wireless Wi-Fi communication channel to simulate 3D video using the FTP protocol was carried out. In accordance with the RF patent No. 2707582, each transmitted frame of a 3D image was the sum of two 2D frames-a texture (2000x2000 pixels) and a mask (1000x1000 pixels). To simulate the transmission of a video sequence, packets of 500 double frames were transmitted simultaneously. The transmission times of these frame packets measured in real time by FileZilla showed that the transmission of full holographic information about a 3D object in real time with a frame rate greater than 25 frames / sec. quite feasible.

Research Advances of Leptotrombidium scutellare in China

Leptotrombidium scutellare is one of the 6 main vectors of scrub typhus in China. It has been found in more than 15 provinces of China. Especially in Yunnan, it was found to be mainly distributed in some mountainous areas with high altitude, low temperature and low precipitation. Rodents and some other small mammals were the most common hosts of L. scutellare. To date, more than 40 host species of L. scutellare have been recorded with very low host specificity, and the main hosts varied in different geographical regions. L. scutellare had a strong resistance against the cold environment, and the temperature and humidity were 2 important factors affecting its growth and development. Among different individuals of their rodent hosts, L. scutellare mites often showed an aggregated distribution pattern, which reflected the interspecific cooperation of the mites. The chromosome karyotype of L. scutellare was 2n=16 and all the 8 pairs of chromosomes were short rod-shaped with metacentric or sub-metacentric types. The isozyme spectrum supported that L. scutellare, L. deliense and L. rubellum were in the same species group. Based on the natural infection, experimental transmission and epidemiological evidence, L. scutellare has been eventually confirmed as the second major vector of scrub typhus in China, which is second only to L. deliense.

Sheep Pox in North Western and North Central States of Nigeria

SHEEP pox in two northern states of Nigeria is reported. The disease produced nodules which became popular, vesicular and ulcerated on the skin. Lesions also developed in the respiratory, urogenital and alimentary organs The importance of the disease in animal production and its control are discussed. Viral isolation was not done but the disease was experimentally reproduced. Diagnosis was based on clinical history, experimental transmission and morphological examination