Salivary glands from males of 3 Dermacentor species (D andersoni, D variabilis and D occidentalis) that were infected with either the Virginia or Idaho isolate of Anaplasma marginale as nymphs or adults were examined for colonies of A marginale by use of light and electron microscopy. Prior to dissection of salivary glands, exposed ticks were held at 25 C for 15 to 18 days, followed by a 3-day incubation at 37 C. Ticks of 2 species transmitted A marginale to calves; the third tick species was confirmed infected by demonstration of typical colonies in tick gut cells, but transmission was not attempted; Colonies of A marginale were seen with light microscopy in salivary glands of all 3 species of ticks; they were located in acinar cells that contained simple granules. Colonies varied morphologically from small, compact ones to larger structures that contained distinct organisms and often were adjacent to the host cell nucleus. Electron microscopy confirmed that the colonies were rickettsial organisms. Morphologic features of A marginale varied and included reticulated forms, forms with electron-dense centers, and small particles; these various forms were similar to those described previously in midgut epithelial cells of ticks. We believe that the organism seen within tick salivary glands may replicate in the glands before its transmission to the vertebrate host.

The amphotropic murine leukemia virus (MLV) has been shown to infect mammalian species other than mice. If this virus infects and expresses genes in cells of livestock species (cattle, sheep, and pigs) it has potential for use as a vector to produce transgenic livestock. Because the gene-injection technique for producing transgenic animals is inherently inefficient, our laboratory was interested in identifying or constructing retroviral vectors capable of infecting livestock embryos. The infectivity of an amphotropic MLV-based vector for ovine, bovine, and porcine cells was tested. Experiments were also conducted to test the ability of the amphotropic MLV promoter, compared with known strong promoters, to express genes in cells from these species. Results indicated that amphotropic MLV infects and expresses genes efficiently in porcine cells and is, therefore, a potential vector for producing transgenic pigs. Infection was not detected in cells from adult bovine and ovine species; however, low levels of infection, with subsequent gene expression, were detected in cells derived from bovine embryos.

Bovine leukemia virus (BLV) was transmitted by horse flies, Tabanus fuscicostatus, from a cow with a lymphocyte count of 31,500/mm3 to goats and dairy calves. As few as 10 and 20 flies transmitted BLV to goats and calves respectively, but the minimal number of flies required to transmit the infection was not established. Groups of 150 and 100 T fuscicostatus transmitted BLV to beef calves from a cow with a lymphocyte count of 14,600/mm3. These results support a role for horse flies in the horizontal transmission of BLV.

White sturgeon iridovirus (WSIV) disease is caused by a virus of the eponymous family and is mostly triggered by stressful environmental conditions, i.e. high rearing density, excessive handling, or temporary loss of water. The aim of this study was to develop the most effective diagnostic method for quick and efficient confirmation or exclusion of the presence of WSIV. A total of 42 samples (spleen, gills, intestine, skin, kidney, and brain) were collected from eight sturgeon (Acipenser gueldenstaedtii and A. oxyrinchus) aged ≤5+ farmed or caught between 2010 and 2014 in open waters (Dąbie Lake and Szczecin Lagoon). They were tested for WSIV presence using conventional PCR, qPCR, and in situ hybridisation (ISH). In gross examination, all fish appeared to be healthy. Neither species showed clinical signs typical of WSIV infection. In the majority of cases, fragments of iridoviral DNA were found using molecular methods in the kidneys, and also in the liver, gills, and skin. The detection rate using ISH was 47.37% and most commonly the brain and kidney tissues were positive. The most efficient of the methods used was real-time PCR, with 100% effectiveness in detection of WSIV DNA. The study demonstrates the capabilities for WSIV diagnosis available to sturgeon farmers and water administrators, indicating useful methods of adequate sensitivity as well as organs to sample in order to achieve the highest probability of viral detection.

Koi herpesvirus (KHV) has infected farmed common carp in Poland clinically and asymptomatically since 2004. The role of non-carp species as vectors of virus transmission is well known except for in the case of KHV. The aim was to better understand this virus’ infection and transmission pathways in common carp, looking at the potential vector role of fishes kept with them. Eight species were experimentally infected with KHV by immersion in a suspension at 20°C ±1 and transferred to a tank after 45 minutes. Specimens were euthanised at intervals up to 56 days post infection (dpi) and tissue was examined for KHV DNA. Surviving infected fishes were introduced at intervals, each time into a separate tank, to naïve common carp for experimental infection. These were observed daily for symptoms, sacrificed along with controls after three months, and dissected to provide tissue samples. Also fish from 14 species collected from a farm with a history of KHV were sampled from 3 to 22 months after disease was confirmed. Organ sections from single fish were collected in a single tube. Viral DNA was detected in tench and roach samples up to 49 dpi, but in three-spined stickleback and stone maroko samples only up to 14 dpi. Transmission of KHV to naïve carp occurred after cohabitation. KHV DNA was detected in three fish species three months after the farm outbreak. We confirmed that grass and Prussian carp, tench, roach, and brown bullhead can transfer the virus to naïve common carp.

Koi herpesvirus (KHV) has infected farmed common carp in Poland clinically and asymptomatically since 2004. The role of non-carp species as vectors of virus transmission is well known except for in the case of KHV. The aim was to better understand this virus’ infection and transmission pathways in common carp, looking at the potential vector role of fishes kept with them.

White sturgeon iridovirus (WSIV) disease is caused by a virus of the eponymous family and is mostly triggered by stressful environmental conditions, i.e. high rearing density, excessive handling, or temporary loss of water. The aim of this study was to develop the most effective diagnostic method for quick and efficient confirmation or exclusion of the presence of WSIV.

A total of 103 blood samples from pet dogs around Ipoh were screenedfor common blood protozoa. A total of 14 samples were found positive for Erhlichia canis and one sample was found positive for microfilaria of Dirofilaria immitis. Both these diseases are transmitted by vectors; ticks (Rhipicephalus sangiuneus) and mosquitoes respectively. In the hot and wet tropical environment where vectors are abundant, pet care, hygiene and regular screening will help veterinarians detect these infections early to facilitatetreatment.