Japanese Journal of Veterinary Research最新文献

The aim of the present study was to evaluate the frequency of antibiotic resistance in Salmonella spp. strains from wild animals in captivity at the Culiacan Zoo and the Mazatlan Aquarium in Sinaloa, Mexico. We identified 17 different Salmonella enterica serovars at a prevalence of 19.90% (Culiacan Zoo) and 6.25% (Mazatlan Aquarium). Antibiotic sensitivity tests revealed that, of the 83 strains studied, 100% were multidrug resistant (MDR). The drugs against which the greatest resistance was observed were: penicillin, erythromycin, dicloxacillin, ampicillin, cephalothin, and chloramphenicol. We therefore conclude that MDR is common among Salmonella isolates originating from wild animals in captivity in Sinaloa.

Contamination levels of coplanar polychlorinated biphenyls (Co-PCBs), polycyclic aromatic hydrocarbons (PAHs), and dichlorodiphenyltrichloroethane (DDTs) were measured in the entire body of the large Japanese field mouse (Apodemus speciosus) collected from Hokkaido (Ishikari and Rankoshi) and Aomori prefecture (Takko) in Japan. Higher concentrations of PCBs including Co-PCBs, were observed in the mice collected from Ishikari than those from Rankoshi. The concentration of PAHs in the soil from Ishikari was also higher than that in the other sampling sites. The findings suggest that Ishikari is the most polluted area, probably because of human activities, depending on the population distribution. However, the observed contaminant levels were extremely lower compared to those in previous studies. The ratio of testis weight to body weight (TW/BW) was the lowest in the mice collected from Ishikari, which is the area contaminated with PAHs and p,p'-dichlorodiphenyldichloroethylene (DDE). However, the serum testosterone levels of mice from the Ishikari area were higher than those from the non-contaminated other areas although no significant differences. Previous studies have shown that a low-level exposure to dioxin related compounds (DRCs) disturbances in sexual function, resulting in the production of testosterone. This study showed that POPs exposure is one of the possibility of the high testosterone concentration in the mice of the Ishikari area in addition to a cause of biological and environmental factors such as habitat density, age, temperatures and/or food riches.

The 23-kDa piroplasm membrane protein of Theileria orientalis (p23) is an immunogenic protein expressed during the intraerythrocytic stage of the parasite; its function, however, remains unclear. To evaluate the host factor or factors that interact with p23, we examined the binding of p23 to components of the host cell surface. Recombinant p23 protein of the Ikeda genotype failed to bind to bovine red blood cells or to peripheral blood mononuclear cells, but did bind to Madin-Darby Bovine Kidney (MDBK) cells. A glycoarray assay showed that recombinant p23 proteins from the three genotypes bound to heparin, indicating that p23 is a heparin-binding Theileria surface molecule. Further analysis of heparin-binding molecules is useful for understanding attachment and invasion of T. orientalis merozoites.

Cardiomyopathies are the most common type of cardiac diseases in cats. Although some normal echocardiographic values for cats have been published, there are variations based on breeds and gender. The objective of this study is to determine normal reference values for M-mode echocardiographic parameters in nonsedated healthy adult Van cats and to compare those values with data reported for nonsedated healthy cats of other breeds. A total of 40 clinically healthy Van cats of both sexes belonging to the Van Cat Research and Application Center of Yuzuncu Yil University were used. Body weight (BW) and 16 M-mode echocardiographic variables were measured in 40 healthy Van cats. The effect of gender and age on each echocardiographic parameter was analyzed and the relationship between BW and each parameter investigated. There was a significant relationship between gender and left atrial dimension during ventricular systole (LAD) and aortic root dimension at end-diastole (AOD) as well as between BW and interventricular septal thickness at end-diastole (IVSd) and end-systole (IVSs), left ventricular internal dimension at end-diastole (LVIDd), left ventricular posterior wall thickness at end-diastole (LVPWd), LAD, AOD, the left ventricular end diastolic volume (EDV) and the stroke volume (SV). A relationship between age and the SV parameter alone was also established. This present study is the first work on cardiac reference values for Van cats highlighting the differences in some M-mode echocardiographic parameters of healthy adult Van cats and other cat breeds, which should be considered when interpreting echocardiographic findings, in order to draw the correct conclusions regarding cardiac health.

We determined the antimicrobial resistance of Salmonella serovars from a total of 154 (44 chilling waters and 110 carcasses) samples collected from 22 poultry slaughterhouses. Standard culture techniques, Kauffmann-White slide agglutination and disc diffusion tests were used to isolate, and identify the serovars and to assess the antimicrobial activity, respectively. A total of 88 isolates belonging to 34 Salmonella serovars from 67 (43.5%) positive samples were identified. Among the samples examined, 68.2% (15/22), 22.7% (5/22), and 42.7% (47/110) from the first chilling waters, the last chilling waters, and carcasses were found contaminated with Salmonella, respectively. The prevalent serovars were S. Enteritidis (12.5%) followed by S. Montevideo and S. Senftenberg (8.0%). Rare Salmonella serovars such as S. Aba, S. Malmoe, S. Westhampton, S. Takoradi, and S. Baiboukoum in chicken slaughterhouses and S. Newbrunswick, S. Huddinge S. Glostrup, S. Dujugu, S. Goettingen and S. II in duck slaughterhouses were also detected. Among the serovars, 52.3% (46/88) and 21.6% (19/88) were resistant to one antibiotic and more than two antibiotics, respectively. High antimicrobial resistance rates against sulfamethoxazole (39.8%) followed by tetracycline (22.7%), nalidixic acid (21.6%), ampicillin and amoxicillin-clavulanic acid (8.0%), and chloramphenicol (4.5%) were observed. These results suggest more stringent hygienic measures should be taken to reduce the incidence of pathogen contamination in the food chain.

Digestive enzymes in tsetse fly midgut are thought to modulate the development of African trypanosome which is a causative agent of trypanosomosis in human and animal. Cathepsin B is induced after the first blood meal ingestion and being higher in trypanosome infected flies. A DNA fragment encoding pro-cathepsin B (930 bp) (Accession No. AF329480_1) was cloned and expressed in E. coli and P. pastoris protein expression systems. An active recombinant cathepsin B (rGmcathB) produced by P. pastoris was migrating from 35 to 45 kDa under reducing condition, rGmcathB exhibited the highest proteolytic activity at pH 4.0 with wide range temperature 25-30 degrees C, also degraded bovine hemoglobin and serum albumin. rGmcathB exhibited hydrolysis preference for Z-Arg-Arg-MCA (K(cat)/K(M) 7.58 mM(-1)sec(-1)) and bovine hemoglobin (K(cat)/K(M) 3.77 x 10(3) mM(-1)sec(-1)). The proteolytic activity of rGmcathB was inhibited by specific cysteine protease inhibitor (E-64) confirmed belonging to papain-like cysteine protease family. These results indicated that rGmcathB shows the activity of cathepsin B and have high affinity with blood protein referring a role in blood meal digestion. In this study, the recombinant protein expressed by E. coli expression system was not enzymatically active as shown in the recombinant protein expressed by P. pastoris expression system. This finding implies that P. pastoris expression system is more suitable for expressing enzymatically active recombinant proteases than E. coli expression system.

As a preliminary study for the development of individual in vitro maturation (IVM) culture of bovine oocytes, a multi-well (MW) plate was used. Maturation, fertilization and development to blastocysts were examined and compared with those of IVM oocytes cultured in 50-microl droplets in groups and in 10-microl droplets individually. The maturation rates were similar in all experimental groups. Normal fertilization rates in MW and 50-microl droplets were similar, but lower in 10-microl droplets (p < 0.01). The blastocyst rate in 10-microl droplets tended to be lower than those in MW (p = 0.15) and 50-microl droplets (p = 0.19). These results indicate that an IVM system using MW supports the acquisition of developmental competence by bovine oocytes the same as conventional group IVM culture.

Cyclooxygenase (COX)-2 participates essentially in bone healing, demonstrated by COX-2 knockout mice that showed delayed fracture repair. Considerable controversy still exists on inhibitory effects of COX-2 inhibitors on bone healing in clinical cases. To assess stage-dependent effects of short-term treatment of COX-2 inhibitors on osteogenic differentiation, a canine POS osteosarcoma cell line which spontaneously differentiates into osteoblastic cell was exposed to COX-2 inhibitors such as carprofen and meloxicam for 72 hours during three different stages of osteoblast differentiation, including day 0 to 3 (pre-osteoblastic stage), day 4 to 7 (transitional stage) and day 8 to 11 (mature osteoblastic stage). As osteogenic markers, expression of alkaline phosphatase (ALP) was estimated by analysis of mRNA expression, enzymatic activity and ALP staining, and expression of osteocalcin was estimated by analysis of mRNA expression after the drug treatments. Calcified matrix formation was finally observed by von Kossa staining on day 14. Expressions of ALP showed no significant suppression by carprofen and meloxicam during all three stages. However, expressions of osteocalcin mRNA and non-calcified nodule formations were delayed by carprofen and meloxicam during transitional stage. Nevertheless, fully calcified nodule formation was observed in all experimental groups during post-medication period. These results indicate that short-term treatment of carprofen and meloxicam would reversibly suppress the differentiation of osteoblasts.

Blood samples from 105 northern pintails (Anas acuta) captured on Hokkaido, Japan were tested for antibodies to avian influenza virus (AIV), Japanese encephalitis virus (JEV), and West Nile virus (WNV) to assess possible involvement of this species in the spread of economically important and potentially zoonotic pathogens. Antibodies to AIV were detected in 64 of 105 samples (61%). Of the 64 positives, 95% and 81% inhibited agglutination of two different H5 AIV antigens (H5N1 and H5N9), respectively. Antibodies to JEV and WNV were detected in five (5%) and none of the samples, respectively. Results provide evidence for prior exposure of migrating northern pintails to H5 AIV which couldhave implications for viral shedding and disease occurrence. Results also provide evidence for limited involvement of this species in the transmission and spread of flaviviruses during spring migration.

Animals persistently infected (PI) with bovine viral diarrhea virus (BVDV) play an important role in the spread of BVDV. Alteration of maternal C-X-C chemokine receptor type 4 (CXCR4) expression has been suspected as closely concerned with the production of PI calves. It is not clear what the influence of CXCR4 response to the prevalence of PI calves. We have previously reported a dairy herd with high prevalence of PI calves within a short period having a single origin of infection. CXCR4 and cytokine expressions in cows of this herd were investigated. There were no significant differences in CXCR4 and cytokine expressions between the dams of PI calves and the dams of non PI calves in the herd. In the comparison among the herds, CXCR4 expressions in the PI producing herds were significantly lower than the BVDV-free herd. Moreover, CXCR4 expressions in the high prevalence herd and the low prevalence herd were similar. These findings among herds corresponded with the previously reported experimental production of persistent infection with BVDV in cows. Based on the cytokine profile of these herds, IL-10 was significantly higher in the high prevalence herd and the BVDV-free herd. The combination of low expression of CXCR4 and high expression of IL-10 might be closely concerned with some bias for the production of PI calves.