First record of avian Plasmodium DNA from mosquitoes collected in the Yaeyama Archipelago, southwestern border of Japan

We studied the prevalence of avian Plasmodium in 509 mosquitoes of 9 species collected from the Ishigaki and Iriomote islands in the Yaeyama Archipelago, located southwest from the mainland of Japan. Two identical avian Plasmodium lineages were detected from Culex (Culiciomyia) nigropunctatus. Detected lineages were phylogenetically classified into different clade to avian Plasmodium lineages from birds and mosquitoes in the mainland of Japan but identical to a lineage detected from a resident bird, White-breasted Waterken (Amaurornis phoenicurus). This is the first detection of avian Plasmodium DNA from mosquitoes in the Yaeyama Archipelago and suggested that resident birds might have been infected with an avian Plasmodium lineage specific to the studied area and C. nigropunctatus could be the candidate vector mosquito species.     

Molecular Detection of Avian Pathogens in Poultry Red Mite (Dermanyssus gallinae) Collected in Chicken Farms

Poultry red mite (PRM, Dermanyssus gallinae) is a blood-sucking ectoparasite as well as a possible vector of several avian pathogens. In this study, to define the role of PRM in the prevalence of avian infectious agents, we used polymerase chain reaction (PCR) to check for the presence of seven pathogens: Avipox virus (APV), Fowl Adenovirus (FAdV), Marek’s disease virus (MDV), Erysipelothrix rhusiopathiae (ER), Salmonella enterica (SE), Mycoplasma synoviae (MS) and Mycoplasma gallisepticum (MG). A total of 159 PRM samples collected between 2004 and 2012 from 142 chicken farms in 38 prefectures in Japan were examined. APV DNA was detected in 22 samples (13.8%), 19 of which were wild-type APV. 16S ribosomal RNA (16S rRNA) of MS was detected in 15 samples (9.4%), and the mgc2 gene of MG was detected in 2 samples (1.3%). Eight of 15 MS 16S rRNA sequences differed from the vaccine sequence, indicating they were wild-type strains, while both of the MG mgc2 gene sequences detected were identical to the vaccine sequences. Of these avian pathogen-positive mite samples, three were positive for both wild-types of APV and MS. On the other hand, the DNAs of ER, SE, FAdV and MDV were not detected in any samples. These findings indicated that PRM can harbor the wild-type pathogens and might play a role as a vector in spreading these diseases in farms.     

Isolation of exfoliative toxin from Staphylococcus intermedius and its local toxicity in dogs

A rounding effect was demonstrated in cultured cells inoculated with the culture filtrates (CFs) of 60 strains of Staphylococcus intermedius derived from dogs affected with pyoderma. Exfoliative toxin (ET)-like toxin (ETLT) was isolated from the CF of S. intermedius strain D-52, which exhibited strong rounding activity and then was purified by gel filtration on a Sephadex G-75 column, and by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The ETLT caused exfoliation in 1-day-old chickens, suckling Syrian hamsters, and dogs, but not in suckling mice. The ETLT was serologically different from exfoliative toxin A (ETA), exfoliative toxin B (ETB), exfoliative toxin C (ETC), S. hyicus exfoliative toxin A (SHETA), and SHETB, as shown by Western blot analysis. The molecular weight of the ETLT was estimated at 30 kDa by SDS-PAGE. In the present study, we propose the ETLT was a novel type of ET, S. intermedius exfoliative toxin (SIET).     

Fenprostalene-induced abortion in bitches

A long-acting prostaglandin F(2alpha) analogue, fenprostalene, was subcutaneously administered singly at doses of 5, 10, 25, 50, 100 or 150 microg on day 25 after ovulation during pregnancy in bitches (n=4 for each dosage), and maintenance of pregnancy, changes in plasma progesterone concentration, interval between the treatment and subsequent estrus and conception rate at that estrus were studied. Abortion was associated with a decrease in the plasma progesterone concentration below about 2 ng/ml, and the abortifacient effect was dose-dependent. Administration of 50 microg or more of fenprostalene induced abortion in all dogs 3 to 13 days after the treatment. The interval between administration and subsequent estrus was markedly shorter in the aborted bitches than in the non-aborted ones (P<0.01). The conception rate at the estrus in the aborted dogs was 50%, whereas all of the bitches who had not aborted became pregnant. The results indicate that a single administration of fenprostalene could induce abortion during mid-pregnancy in bitches, and the subsequent estrus may come early with a low conception rate.     

Ammonia-assimilating microbes in microbial community in a lagoon for wastewater from paddock of dairy cattle

In the present article the distribution and abundance of ammonia‐assimilating microbes among the natural habitants in a lagoon were investigated. In the medium containing lagoon‐extract, about 20% of total 82 isolates showed ammonia‐assimilating ability. By sequencing of 16S ribosomal DNA (rDNA), the highest ammonia‐assimilating isolates at 10°C and 37°C were identified as Janthinobacterium lividum and Bacillus sp., respectively. The structure of the microbial community was analyzed by polymerase chain reaction‐denaturing gradient gel electrophoresis (PCR‐DGGE). Almost of the dominant species that were detected by PCR‐DGGE did not coincide with isolates, which showed the high ammonia‐assimilating ability, but one specie by PCR‐DGGE coincided with ammonia‐assimilating isolate. These results suggested that ammonia‐assimilating microbes existed as non‐dominant species in the microbial community in a lagoon.     

Estrous cycle based on blood progesterone profiles and changes in vulvar appearance of Malayan tapirs (Tapirus indicus)

The progesterone (P(4)) profiles and macroscopic vulvar changes of female Malayan tapirs were investigated in order to understand their fundamental reproductive physiology and to search for visual indicators of estrus. Blood was collected once or twice a week from seven female Malayan tapirs kept at four zoos. Serum or plasma P(4) concentrations were determined by radioimmunoassay. The P(4) concentrations changed cyclically throughout the years, and a total of 56 cycles was confirmed in the seven females. The length of the estrous cycle based on the P(4) profiles was 43.6+/-2.0 days; however, this mean includes great variation in length, from 21 to 84 days. Mucous discharge from the vulva and vulvar swelling were seen when the P(4) concentrations were low before the beginning of a rise in most cases. In conclusion, captive female Malayan tapirs have variations of approximately 1 to 3 months in estrous cycle length, and visual changes in the vulva are helpful in estimating estrus in female Malayan tapirs.