Two Amino Acid Substitutions in the Coat Protein of Pepper mild mottle virus Are Responsible for Overcoming the L(4) Gene-Mediated Resistance in Capsicum spp

ABSTRACT The Capsicum spp. L genes (L(1) to L(4)) confer resistance to tobamoviruses. Currently, the L(4) gene from Capsicum chacoense is the most effective resistance gene and has been used widely in breeding programs in Japan which have developed new resistant cultivars against Pepper mild mottle virus (PMMoV). However, in 2004, mild mosaic symptoms began appearing on the leaves of commercial pepper plants in the field which possessed the L(4) resistance gene. Serological and biological assays on Capsicum spp. identified the causal virus strain as a previously unreported pathotype, P(1,2,3,4). PMMoV sequence analysis of the virus and site-directed mutagenesis using a PMMoV-J of the P(1,2) pathotype revealed that two amino acid substitutions in the coat protein, Gln to Arg at position 46 and Gly to Lys at position 85, were responsible for overcoming the L(4) resistance gene.     

Two Eimeria species isolated from wild Japanese rock ptarmigans (Lagopus mutus japonicus) in Japan

Fecal samples were collected from 64 Japanese rock ptarmigans (Lagopus mutus japonicus) at 13 locations in the alpine zone of Japan and examined for internal parasites. We found 2 morphologically different types of eimerian oocysts. Based on morphological characteristics, one was identified as Eimeria uekii, which had already been found from Japanese rock ptarmigans in 1981, and the other was likely a new type of Eimeria. The new type of eimerian oocysts required a longer sporulation time than E. uekii. The prevalence of both eimerian oocysts in Japanese rock ptarmigans was 62.5%, while that of E. uekii was 60.9% and the new type 29.7%. Mixed infection of both types was found in 28.1%.     

Canine serum thermostable alkaline phosphatase isoenzyme from a dog with hepatocellular carcinoma

A dog histopathologically diagnosed with hepatocellular carcinoma (HCC) showed very high serum alkaline phosphatase (ALP) activity. A supernatant of ascitic fluid and tumor tissue extracted from the dog also showed much higher ALP activity than normal. ALP isoenzyme analysis of samples was performed using polyacrylamide gel disk electrophoresis, and a wide, broad abnormal band was observed. By various treatments, the abnormal band showed thermostability, which is a characteristic of tumor-associated ALP that has only been reported in humans. The thermostable ALP isoenzyme was not found in sera from 39 dogs with several types of tumor that originated from the liver, except for HCC, nor was it found in 10 dogs with hepatic diseases that did not include hepatic tumors. The thermostable ALP isoenzyme seemed to be associated with canine HCC.     

Comparison of the insulin reaction of peripheral blood T cells between healthy Holstein dairy cows and JB during the periparturient period

To compare the changes in the insulin reaction of Holstein dairy cows and Japanese Black cows (JB) during the periparturient period, the insulin resistance test in vivo and lymphocytes proliferation with insulin in vitro were performed. Ten healthy Holstein dairy cows (Holstein group) and 10 healthy JB cows (JB group) used in this study were observed on days 60, 40, and 20 before calving and days 7 and 20 after calving. In insulin resistance reaction in vivo and in vitro, a low insulin-stimulated glucose disposal rate and lymphocyte proliferation with insulin were observed in the Holstein group compared with the JB group during the experimental period. An analysis of the lymphocytes cultured with insulin showed that the percentage of CD4+CD45R- T cells in the Holstein group was significantly lower than that of the JB group before day 20. These findings indicate that T cells reaction to insulin in healthy periparturient Holstein cows is lower than that in Japanese Black.     

Diabetes mellitus after resection of hepatocellular carcinoma with hypoglycemia in a dog

A 10-year-old male beagle was referred to us with seizure related to hypoglycemia and a large intraabdominal mass. Based on various types of imaging and a laparoscopic biopsy, the intraabdominal mass was diagnosed as a hepatocellular carcinoma (HCC) of the quadrate lobe. The hypoglycemia was suspected to be associated with the HCC. After lobectomy of the quadrate lobe was performed, blood glucose levels continued to increase to higher than normal values and sugar was detected in the urine. The dog was diagnosed as diabetes mellitus (DM) and was treated with insulin for over two years after the surgery.     

Seroepidemiological survey of morbillivirus infection in Kuril harbor seals (Phoca vitulina stejnegeri) of Hokkaido, Japan

Serological analysis was performed to detect morbillivirus infection in Kuril harbor seals in Hokkaido, Japan. Serum samples were collected from the seals at Nosappu (231 sera), Akkeshi (16), and Erimo (75) between 1998 and 2005. Antibodies to phocine distemper virus (PDV) were detected by ELISA in seals from Nosappu and Erimo. Antibodies to PDV were found in 56% (5/9) of the sampled seals from Nosappu in 1998, versus only 5% (3/66) for 2003, 1% (1/79) for 2004, and 1% (1/77) for 2005. These suggest epidemic caused by the virus in or before 1998. As antibody-positive seals included juvenile seals in 2003 and 2005, sporadic infections of the virus are thought to have occurred in recent years. In Erimo, antibodies to PDV were found in 50% (14/28) of sampled seals in 2004, versus only 13% (1/8) for 1999, 7% (1/15) for 2003, and 0% (0/24) for 2005. These suggest sporadic infection by the virus before 2003 and the epizootic between after autumn in 2003, when samples of 2003 were collected, and 2004. Since antibodies to canine distemper virus (CDV) were detected in one adult seal from Nosappu in each year from 2003 to 2005, sporadic infections of the virus were suggested. There were no difference in incidence of seals with antibodies to the viruses between males and females and between juveniles and adults.     

MRI findings of haematomyelia in a dog with spontaneous systemic haemorrhage

A 7-year-old female cross-breed dog was brought to Nihon University Animal Medical Center for investigation of tetraplegia. Lameness in the pelvic limbs, that had developed 2 weeks previously, had progressed to tetraplegia. On magnetic resonance imaging of the spinal cord, isointensity was detected from C2 to C4 and T12 to T13, isointensity and hyperintensity were intermingled from L3 to L4, and hyperintensity was detected from L5 to L7 by T1-weighted imaging. On T2-weighted imaging, hyperintensity was detected in all regions described above. The dog recovered from anaesthesia, but died during the day from systemic bleeding as the result of a coagulopathy of unknown aetiology. Histopathological examination revealed haematomyelia in these regions of the spinal cord. This is the first report of magnetic resonance imaging findings of haematomyelia in canine spontaneous systemic haemorrhage. It appeared that the differences in the findings of T1-weighted imaging along the spinal regions reflected time-lags in the occurrence of bleeding.     

Infectivity of porcine circovirus 1 and circovirus 2 in primary porcine hepatocyte and kidney cell cultures

Infectivity of porcine circovirus (PCV) 1 and PCV2 was examined in primary porcine hepatocyte culture by comparing that of PCV in primary kidney cell culture. The virus titer of PCV2-infected hepatocyte cultures was higher than that of the PCV1-infected hepatocyte cultures and the PCV-infected kidney cell cultures. The number of virus-positive cells was most abundant in PCV2-infected hepatocyte cultures as determined by immunohistochemistry and/or in situ hybridization. The results of our data suggest that PCV2 preferably infects cultured hepatocytes as observed in the liver of pigs with postweaning multisystemic wasting syndrome.     

Gastrointestinal helminths of feral raccoons (Procyon lotor) in Wakayama Prefecture, Japan

The population and distribution of feral raccoons (Procyon lotor) are expanding in Japan after escape or release from animal-owners. Wakayama Prefecture is one of the most typically devastated areas by this exotic carnivore, particularly in the last five years after a latent distribution for more than ten years. Official control measures of feral raccoons commenced in the summer of 2002 by several municipalities, and 531 animals collected in 12 municipalities between May 2003 and April 2005 were submitted for parasitological examination of gastrointestinal helminths. Detected parasites included six nematodes (Physaloptera sp. [prevalence; 5.1%], Contracaecum spiculigerum [0.9%], Strongyloides procyonis [25.5%], Ancylostoma kusimaense [0.8%], Arthrostoma miyazakiense [0.4%], and Molineus legerae [1.1%]), seven trematodes (Isthmiophora hortensis [4.9%], echinostomatid sp. with 34-39 collar spines [1.7%], Metagonimus takahashii [12.4%], M. yokogawai [0.8%], Plagiorchis muris [0.2%], Macroorchis spinulosus [1.9%], and Consinium ten [0.2%]), one cestode (Mesocestoides sp. [0.2%]), and six acanthocephalan spp. (Centrorhynchus bazalenticus [0.2%], Centrorhynchus teres [5.5%], Sphaerirostris lanceoides [2.4%], Plagiorhynchus ogatai [0.6%], Porrorchis oti [1.5%], and Southwelina hispida [1.9%]). Most of the collected parasites are food-borne, indigenous helminth species. Physaloptera sp. has never been recorded in indigenous wild carnivores in Japan, and resembles closely P. rara, prevalent in raccoons of North America, in morphology. The position of a pair of phasmids in the posteroventral region of the adult male, however, could differentiate it from P. rara. Since Strongyloides procyonis is known to cause creeping eruption as well as intestinal infection in a healthy human volunteer, we should be concerned about the rapid increase in the population and distribution of feral raccoons in Japan from the viewpoint of public health as well.     

In vitro cultivation and partial characterization of Lawsonia intracellularis from a Japanese field case of porcine proliferative enteropathy

Lawsonia intracellularis isolated from a Japanese field case of porcine proliferative enteropathy (PPE) was cultivated and partially characterized. The bacterial cells isolated from the intestinal mucosa of a pig suffering from the acute form of PPE were used to inoculate rat small intestine cells (IEC-18) and human epithelial cells (HEp-2). Infected foci, which were stained with L. intracellularis-specific rabbit antiserum, were observed in the cell culture at 5 days post inoculation. The DNA sequence of several genes in the Japanese isolate had high similarity with those of the L. intracellularis type strain, suggesting the genetically close relationship of the two strains. This is the first report describing the cultivation and partial characterization of L. intracellularis originated in Japan.