Tamamura Y.,Japanese National Institute of Animal Health |
Uchida I.,Japanese National Institute of Animal Health |
Uchida I.,Gifu University |
Tanaka K.,Japanese National Institute of Animal Health |
And 15 more authors.
Applied and Environmental Microbiology | Year: 2011
The molecular epidemiology of 545 Salmonella enterica serovar Typhimurium isolates collected between 1977 and 2009 from cattle in Hokkaido, Japan, was investigated using pulsed-field gel electrophoresis (PFGE). Nine main clusters were identified from 116 PFGE patterns. Cluster I comprised 248 isolates, 243 of which possessed a sequence specific to definitive phage type 104 (DT104) or U302. The cluster I isolates were dominant in 1993 to 2003, but their numbers declined beginning in 2004. Beginning in 2002, an increase was observed in the number of cluster VII isolates, consisting of 21 PFGE patterns comprising 165 isolates. A total of 116 isolates representative of the 116 PFGE profiles were analyzed by multilocus variable-number tandem-repeat analysis (MLVA). Other than two drug-sensitive isolates, 19 isolates within cluster VII were classified in the same cluster by MLVA. Among the cluster VII isolates, an antibiotic resistance type showing resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, tetracycline, kanamycin, cefazolin, and sulfamethoxazole-trimethoprim and a resistance type showing resistance to ampicillin, streptomycin, sulfonamides, tetracycline, and kanamycin were found in 23 and 125 isolates, respectively. In the 19 isolates representative of cluster VII, the bla TEM-1 gene was found on a Salmonella serotype Typhimurium virulence plasmid, which was transferred to Escherichia coli by electroporation along with resistance to two to four other antimicrobials. Genomic analysis by subtractive hybridization and plasmid analysis suggested that the bla TEM-1-carrying virulence plasmid has a mosaic structure composed of elements of different origin. These results indicate an emerging multidrug-resistant S. Typhimurium clone carrying a virulence-resistance plasmid among cattle in Hokkaido, Japan. © 2011, American Society for Microbiology.
Akiba M.,Japan National Agriculture and Food Research Organization |
Akiba M.,Osaka Prefecture University |
Senba H.,Animal Quarantine Service |
Otagiri H.,Tobu Livestock Hygiene Service Center |
And 13 more authors.
Ecotoxicology and Environmental Safety | Year: 2015
The sewage treatment plant (STP) is one of the most important interfaces between the human population and the aquatic environment, leading to contamination of the latter by antimicrobial-resistant bacteria. To identify factors affecting the prevalence of antimicrobial-resistant bacteria, water samples were collected from three different STPs in South India. STP1 exclusively treats sewage generated by a domestic population. STP2 predominantly treats sewage generated by a domestic population with a mix of hospital effluent. STP3 treats effluents generated exclusively by a hospital. The water samples were collected between three intermediate treatment steps including equalization, aeration, and clarification, in addition to the outlet to assess the removal rates of bacteria as the effluent passed through the treatment plant. The samples were collected in three different seasons to study the effect of seasonal variation. Escherichia coli isolated from the water samples were tested for susceptibility to 12 antimicrobials. The results of logistic regression analysis suggest that the hospital wastewater inflow significantly increased the prevalence of antimicrobial-resistant E. coli, whereas the treatment processes and sampling seasons did not affect the prevalence of these isolates. A bias in the genotype distribution of E. coli was observed among the isolates obtained from STP3. In conclusion, hospital wastewaters should be carefully treated to prevent the contamination of Indian environment with antimicrobial-resistant bacteria. © 2015 Elsevier Inc.
Yamamoto T.,Japan National Agriculture and Food Research Organization |
Yamamoto T.,Animal Quarantine Service |
Yoshida K.,Animal Quarantine Service |
Fuchinoue S.,Animal Quarantine Service |
And 3 more authors.
Accreditation and Quality Assurance | Year: 2014
The quality of diagnostic tests conducted by the Animal Quarantine Service (AQS) is critical to the safety of national livestock production. In procedures for tests such as polymerase chain reaction and enzyme-linked immunosorbent assay, measurement of tiny quantities of samples or reagents is quite common. Therefore, many efforts have been made to maintain the quality of micropipette operations, including routine calibration of equipment and training programs for operators. In this study, we developed a pilot training program to analyze the effects of training on pipetting accuracy, i.e., trueness and precision. The program involved a self-instruction A4-sized leaflet describing how to improve pipetting technique. Thirty-three staff members from seven AQS laboratories participated in the program. Each participant repeated sampling of 300 μL of distilled water 10 times before and after reading the leaflet, and the effects of training on the trueness and precision of the pipetting results were analyzed. To determine pipetting trueness, we examined the variation of the delivered volume from the target volume (300 μL) using the proportional odds mixture model. Our data demonstrated that participation in the training program and the level of experience with pipetting significantly improved trueness. Analysis of standard deviations of the ten samplings, as an indicator of precision, also showed that participation in the training program improves pipetting precision. Thus, our data supported the implementation of such simple, quick training sessions to improve pipetting trueness and precision in diagnostic laboratories. © 2014, Springer-Verlag Berlin Heidelberg.
Arai R.,Saitama Prefectural Chuo Livestock Hygiene Service Center |
Arai R.,Gifu University |
Tominaga K.,Yamaguchi Prefectural Institute of Public Health and Environment |
Wu M.,University of Tsukuba |
And 10 more authors.
PLoS ONE | Year: 2012
European foulbrood (EFB) is an important infectious disease of honeybee larvae, but its pathogenic mechanisms are still poorly understood. The causative agent, Melissococcus plutonius, is a fastidious organism, and microaerophilic to anaerobic conditions and the addition of potassium phosphate to culture media are required for growth. Although M. plutonius is believed to be remarkably homologous, in addition to M. plutonius isolates with typical cultural characteristics, M. plutoniuslike organisms, with characteristics seemingly different from those of typical M. plutonius, have often been isolated from diseased larvae with clinical signs of EFB in Japan. Cultural and biochemical characterization of 14 M. plutonius and 19 M. plutonius-like strain/isolates revealed that, unlike typical M. plutonius strain/isolates, M. plutonius-like isolates were not fastidious, and the addition of potassium phosphate was not required for normal growth. Moreover, only M. plutonius-like isolates, but not typical M. plutonius strain/isolates, grew anaerobically on sodium phosphate-supplemented medium and aerobically on some potassium salt-supplemented media, were positive for β-glucosidase activity, hydrolyzed esculin, and produced acid from L-arabinose, D-cellobiose, and salicin. Despite the phenotypic differences, 16S rRNA gene sequence analysis and DNA-DNA hybridization demonstrated that M. plutonius-like organisms were taxonomically identical to M. plutonius. However, by pulsed-field gel electrophoresis analysis, these typical and atypical (M. plutonius-like) isolates were separately grouped into two genetically distinct clusters. Although M. plutonius is known to lose virulence quickly when cultured artificially, experimental infection of representative isolates showed that atypical M. plutonius maintained the ability to cause EFB in honeybee larvae even after cultured in vitro in laboratory media. Because the rapid decrease of virulence in cultured M. plutonius was a major impediment to elucidation of the pathogenesis of EFB, atypical M. plutonius discovered in this study will be a breakthrough in EFB research. © 2012 Arai et al.
PubMed | Manipal University India, Tobu Livestock Hygiene Service Center, Animal Quarantine Service, Osaka Prefecture University and 3 more.
Type: | Journal: Ecotoxicology and environmental safety | Year: 2015
The sewage treatment plant (STP) is one of the most important interfaces between the human population and the aquatic environment, leading to contamination of the latter by antimicrobial-resistant bacteria. To identify factors affecting the prevalence of antimicrobial-resistant bacteria, water samples were collected from three different STPs in South India. STP1 exclusively treats sewage generated by a domestic population. STP2 predominantly treats sewage generated by a domestic population with a mix of hospital effluent. STP3 treats effluents generated exclusively by a hospital. The water samples were collected between three intermediate treatment steps including equalization, aeration, and clarification, in addition to the outlet to assess the removal rates of bacteria as the effluent passed through the treatment plant. The samples were collected in three different seasons to study the effect of seasonal variation. Escherichia coli isolated from the water samples were tested for susceptibility to 12 antimicrobials. The results of logistic regression analysis suggest that the hospital wastewater inflow significantly increased the prevalence of antimicrobial-resistant E. coli, whereas the treatment processes and sampling seasons did not affect the prevalence of these isolates. A bias in the genotype distribution of E. coli was observed among the isolates obtained from STP3. In conclusion, hospital wastewaters should be carefully treated to prevent the contamination of Indian environment with antimicrobial-resistant bacteria.
Sakamoto K.,Japanese National Institute of Animal Health |
Morioka K.,Japanese National Institute of Animal Health |
Fukai K.,Japanese National Institute of Animal Health |
Yamamoto T.,Japanese National Institute of Animal Health |
And 12 more authors.
Japan Agricultural Research Quarterly | Year: 2016
Lao People's Democratic Republic (Lao PDR) submitted a request to Japan for 200,000 doses of expired foot-and-mouth disease (FMD) O type vaccines that were in storage for emergency use. Approximately 100,000 animals, consisting of both cattle and Asian water buffalo (Bubalus bubalus bubalis), received the same vaccine twice within one month in Xieng Khouang province in the northeast area of Lao PDR. Concurrently, the efficacy of three-month expired FMD O type vaccine (6PD50 O Manisa) was assessed in serum samples of 90 cattle and 31 buffalo from the field using a Liquid Phase Blocking-ELISA (LPBE) assay. Of these samples, 75 cattle (83.3%) and 24 buffalo (77.4%) were seropositive against the FMD virus (FMDV) O type before vaccination. Testing for non-structural protein (NSP) using the PrioCHECK FMD NS kit showed that many of the animals with high titers in the screening test before vaccination were FMDV-infected animals. Fifteen cattle and seven buffalo with titers 1:32 or under before vaccination exhibited high titers of antibody (1:45-1:1448) one month after the first vaccination and further increased titers (1:362-1:5792) one month after the second vaccination. Nearly all of the cattle (97.6%) had high titers to control FMD 14 months after the second vaccination. To date, no outbreak of FMD has been reported at the study site. Three-month expired FMD O type vaccines induced appropriate immune responses against FMD in both cattle and buffalo.
Kusumoto M.,Japanese National Institute of Animal Health |
Fukamizu D.,Fukuoka Chuo Livestock Hygiene Service Center |
Ogura Y.,University of Miyazaki |
Yoshida E.,Animal Quarantine Service |
And 6 more authors.
Applied and Environmental Microbiology | Year: 2014
Insertion sequences (ISs) are the simplest transposable elements and are widely distributed in bacteria; however, they also play important roles in genome evolution. We recently identified a protein called IS excision enhancer (IEE) in enterohemorrhagic Escherichia coli (EHEC) O157. IEE promotes the excision of IS elements belonging to the IS3 family, such as IS629, as well as several other families. IEE-mediated IS excision generates various genomic deletions that lead to the diversification of the bacterial genome. IEE has been found in a broad range of bacterial species; however, among sequenced E. coli strains, IEE is primarily found in EHEC isolates. In this study, we investigated non-EHEC pathogenic E. coli strains isolated from domestic animals and found that IEE is distributed in specific lineages of enterotoxigenic E. coli (ETEC) strains of serotypes O139 or O149 isolated from swine. The iee gene is located within integrative elements that are similar to SpLE1 of EHEC O157. All iee-positive ETEC lineages also contained multiple copies of IS629, a preferred substrate of IEE, and their genomic locations varied significantly between strains, as observed in O157. These data suggest that IEE may have been transferred among EHEC and ETEC in swine via SpLE1 or SpLE1-like integrative elements. In addition, IS629 is actively moving in the ETEC O139 and O149 genomes and, as in EHEC O157, is promoting the diversification of these genomes in combination with IEE. © 2014, American Society for Microbiology.
Ishihara K.,Rakuno Gakuen University |
Takahashi R.,Rakuno Gakuen University |
Andoh M.,Tokyo University of Agriculture and Technology |
Makita K.,Rakuno Gakuen University |
And 4 more authors.
Epidemiology and Infection | Year: 2012
Japanese weather data for areas that produced Campylobacter spp.-positive chicken products were compared with those for areas producing negative samples. Regarding samples produced during the period of rising temperature (spring and summer), the mean weekly air temperatures for Campylobacter-positive samples were higher than those for negative samples for the period of the week in which the samples were purchased (18·7°C vs. 13·1°C, P=0·006) to a 12-week lag (12 weeks before purchasing samples; 7·9°C vs. 3·4°C, P=0·009). Significant differences in weekly mean minimum humidity and sunshine duration per day were also observed for 1- and 2-week lag periods. We postulated that the high air temperature, high humidity and short duration of sunshine for the chicken-rearing period increased Campylobacter colonization in chickens during the period of rising temperature. Consequently, the number of Campylobacter-contaminated chicken products on the market in Japan may fluctuate because of the climatic conditions to which reared chickens are exposed. © 2011 Cambridge University Press.