Ryô Harasawa

Rapid detection and differentiation of the major mycoplasma contaminants in cell cultures using real-time PCR with SYBR Green I and melting curve analysis.

A quantitative real‐time polymerase chain reaction (PCR) procedure followed by melting curve analysis, using the green fluorescence dye SYBR Green I, was developed for rapid detection and differentiation of mycoplasma contaminants in cell cultures. This method showed that the detection of the target sequence was linear over a range from 104 to 10 colony‐forming units (CFU) of the mycoplasma cells. Analysis of the melting temperature of the PCR products allowed differentiation of the major mycoplasma contaminants. These results demonstrate that the protocol described in the present study can decrease the time to obtain reproducible results by simultaneous detection and differentiation of the Mycoplasma species contaminating cell cultures.

Mycoplasma fermentans glycolipid-antigen as a pathogen of rheumatoid arthritis.

Mycoplasma fermentans has been suspected as one of the causative pathogenic microorganisms of rheumatoid arthritis (RA) however, the pathogenic mechanism is still unclear. We, previously, reported that glycolipid-antigens (GGPL-I and III) are the major antigens of M. fermentans. Monoclonal antibody against the GGPL-III could detect the existence of the GGPL-III antigens in synovial tissues from RA patients. GGPL-III antigens were detected in 38.1% (32/84) of RA patients tissues, but not in osteoarthritis (OA) and normal synovial tissues. Immunoelectron microscopy revealed that a part of GGPL-III antigens are located at endoplasmic reticulum. GGPL-III significantly induced TNF-alpha and IL-6 production from peripheral blood mononulear cells, and also proliferation of synovial fibroblasts. Further study is necessary to prove that M. fermentans is a causative microorganism of RA; however, the new mechanisms of disease pathogenesis provides hope for the development of effective and safe immunotherapeutic strategies based on the lipid-antigen, GGPL-III, in the near future.

Molecular Evidence for Hemotropic Mycoplasma Infection in a Japanese Badger (Meles meles anakuma) and a Raccoon Dog (Nyctereutes procyonoides viverrinus )

Abstract We report detection of hemoplasma in wild Japanese badgers (Meles meles anakuma) and raccoon dogs (Nyctereutes procyonoides viverrinus). Sequence analysis of the entire 16S rRNA genes identified Mycoplasma haemocanis in the raccoon dog sample, and a potential novel Mycoplasma species in the Japanese badger.

Isolation of Maedi/Visna Virus from a Sheep in Japan

ABSTRACT Maedi/visna (MV) is a lentiviral disease of sheep caused by the maedi/visna virus (MVV). Although MV is prevalent in many countries, it had not been reported in Japan. In 2011, however, three sheep in northern Japan were reported to be seropositive against the MVV antigen, indicating a persistent MVV infection. In the present study, we isolated MVV from one sheep to confirm MVV infection and conducted genomic classification of the virus. The co-culture of leukocytes from a seropositive sheep with fetal goat lung cells resulted in the formation of syncytial cells and the amplification of a long terminal repeat sequence of MVV by polymerase chain reaction. The isolate was confirmed as being MVV, rather than the caprine arthritis-encephalitis virus based on phylogenetic analysis of the gag gene sequence. Although the sheep was asymptomatic, nonpurulent meningitis and demyelination were found in the spinal cord. These were considered to be early lesions associated with pathogenic MVV infection. Therefore, the present study demonstrated that MVV is distributed in Japan.

Evidence for pestivirus infection in free-living Japanese serows, Capricornis crispus

Sixteen serum samples collected from free‐living Japanese serows, Capricornis crispus, between 2001 and 2004 in Morioka and its vicinity were examined for the presence of pestivirus by reverse transcription‐nested PCR procedure. Three out of the 16 samples produced a visible band in electrophoresed agarose gels. The nucleotide sequences of the three PCR products were found to be identical. The pestivirus found in the serow was identified as Bovine viral diarrhea virus 1 (BVDV‐1) based on nucleotide sequence analyses by phylogeny as well as palindromic nucleotide substitutions at the 5′ untranslated regions. Our data first indicated that BVDV‐1 infection occurred continuously among the free‐living serow populations though the role of BVDV‐1 in wild ungulates is currently unknown.

Salivary nitrate and nitrite may have antimicrobial effects on Desulfovibrio species.

The antibacterial effects of salivary nitrate/nitrite on the growth of three Desulfovibrio species were examined. The bacteria did not grow on plates with ≥0.2 mM nitrate or ≥1.0 mM nitrite. They were also incubated in filter-sterilized saliva. D. desulfuricans was reduced on the order of >102 compared with the control solution (phosphate-buffered saline) in nine out of the 10 participants.

Vertical transmission of Mycoplasma wenyonii in cattle, supported by analysis of the ribonuclease P RNA gene - Short communication.

The vertical transmission of Mycoplasma (M.) wenyonii was investigated in beef cattle raised on a farm in Japan by analysing the ribonuclease P RNA (rnpB) gene sequence using PCR. Peripheral blood samples from 17 dams infected with M. wenyonii and from their neonatal calves were collected and colostrum samples were taken from cows immediately after parturition, and subsequently the blood samples of calves were monitored continuously for three months. At birth on day 0, although no rnpB gene was detected in the colostrum of any of the dams, four (23.5%) of the 17 calves born were positive. At three months after delivery, the number of positive calves decreased to three. Although horizontal transmission by blood-feeding arthropod vectors has been basically accepted as the most common route of haemoplasma infection, these findings suggest that vertical transmission is, at least in part, another most likely route of M. wenyonii infection in cattle.

Group B betacoronavirus in rhinolophid bats, Japan.

We report group B Betacoronavirus infection in little Japanese horseshoe bats in Iwate prefecture. We then used reverse-transcription PCR to look for the coronavirus RNA-dependent RNA polymerase gene in fecal samples collected from 27 little Japanese horseshoe bats and found eight were provisionally positive. We had a success in the nucleotide sequencing of six of the eight positive samples and compared them with those of authentic coronaviruses. We found that these six samples were positive in coronavirus infection, and they belonged to the group B Betacornavirus by phylogenetic analysis. Virus isolation using the Vero cell culture was unsuccessful. Pathogenic trait of these bat coronaviruses remained unexplored.

Haemotropic Mycoplasma Infection Revealed by Real-Time PCR in Specific Pathogen-Free Rats

Abstract The presence of Mycoplasma haemomuris (haemoplasma) in blood samples collected from specific pathogen-free (SPF) laboratory rats bred in Japan was reported. Its presence was examined in Fischer 344, Sprague-Dawley (SD), and Wistar rat strains of both sexes by real-time PCR. All strains were positive for M. haemomuris infection. The 16S rRNA gene of M. haemomuris strain detected in the animals was amplified using end-point PCR. Only the entire nucleotide sequence of 16S rRNA gene of a mycoplasma strain detected in SD rats was determined and compared to those of other haemoplasmas. Our investigations suggest a wide M. haemomuris infection among the SPF rats purchased from commercial breeders in Japan.

Effects of urea on length distribution and morphology of Escherichia coli and Salmonella enterica subsp. enterica cells

1 Laboratory of Veterinary Microbiology, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan. 2 The United Graduate School of Veterinary Science, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1193, Japan. 3 Department of Physics, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan. 4 Laboratory of Veterinary Anatomy, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan.