| Summary: | 碩士 === 國立中興大學 === 獸醫學系暨研究所 === 97 === Microorganism isolates, particularly the bacteria are commonly detected in genital tracts of the dogs. Mating process, genital disease and reproductive status would cause the inoculation and growth of bacteria at many occasions in the external and internal genital tracts. In studies of the aerobic bacterial flora of the prepuce, semen and vagina in dogs, the most commonly isolated bacteria in these regions were opportunistic pathogens. The purpose of this study was to investigate the diversity of bacterial distribution in the prepuce, semen and vagina in clinical healthy dogs. Patients of the Fertility Clinic, Veterinary Medical Teaching Hospital, National Chung Hsing University were recruited in this study from Oct 2007 to May 2009. Swabs of 50 intact dogs (46 prepuce and 34 semen samples), 29 intact bitches (29 vagina samples), 13 neutralized dogs (13 prepuce samples), and 7 neutralized bitches (7 vagina samples) were processed and cultured. The cultivable bacteria were identified by morphology, traditional biochemistry methods, Biolog MicroStation system and GFB-14E. Otherwise, unidentified bacteria were tested by 16S rRNA gene sequencing analysis. In total, 108 (including 24 genera and 54 species), 50 (9 genera and 21 species), and 71 (27 genera and 44 species) bacterial strains were identified from normal prepuce, semen and vagina in intact dogs, respectively. From neutralized dogs, 30 (13 genera and 23 species), and 17 (9 genera and 14 species) bacterial strains were identified from normal prepuce and vagina, respectively. Respective number of bacterial isolated from prepuce, semen and vagina was 2 to 1, no growth and 2 to 3 strains. Bacterial number in the kennel dogs was higher than solely living ones (p＜0.05). Current data also infer that housing conditions, estrous cycle and netrutrlization affect bacterial distribution in the canine genital tract and semen. Opportunistic pathogens such as Corynebacterium urealyticum, Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Micrococcus diversus, Proteus mirabilis, Staphylococcus aureus ss aureus, Staphylococcus intermedius, Staphylococcus saprophyticus, Streptococcus agalactiae and Streptococcus canis were constanly identified in the gential tract and semen. Conclusively, Staphylococcus spp. is the superior genus in all samples of gram-positive bacteria, and its most cultivable species are Staphylococcus xylosus, Staphylococcus intermedius and Staphylococcus cohnii. Otherwise, Escherichia spp. and Pasteurella spp. is the superior gram-negative genus in the intact and neutralize samples, respectively. Opportunistic bacteria (n=11) are constantly detected (53/276 isolates) in the canine genital tracts and semen, suggesting proper hygiene is required for all forms of breeding process. Presence of pathogenic bacteria may explain at least in part the cause of canine infertility.
|
|---|
