@article{oai:u-ryukyu.repo.nii.ac.jp:02002730, author = {日越, 博信 and 親里, 真理子 and 宮平, 良成 and 平川, 守彦 and Higoshi, Hironobu and Oyasato, Mariko and Miyahira, Yoshinari and Hirakawa, Morihiko}, issue = {44}, journal = {琉球大学農学部学術報告, The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus}, note = {沖縄本島内の一養鶏場で産卵鶏の日齢別に採取した糞便由来大腸菌合計826株について, 7薬剤に対する感受性試験を行い, また耐性菌については伝達性Rプラスミドの検索も試みた。供試した7薬剤のいずれかに耐性の大腸菌は, 314株(38.0%)であった。日齢別の耐性菌検出率では20日齢が86.9%で最高, 600日齢が8.8%で最低であり, 加齢に伴い低下する傾向を示した。しかし, 500日齢では51.7%を示し, 20日齢に次いで高い値であった。薬剤別ではSA耐性が29.7%で最高, 以下SM, CTC, KM, ABPC耐性などの順であった。各日齢ともSA耐性が1位または2位の検出率を示したが, 200日及び400日齢ではCTC耐性が1位を, また800日齢ではABPC耐性とSA耐性が同率で1位を示すなど, 日齢によって検出順位が異なった。耐性型の種類は, 全体では単剤型から6剤型まで23種類認められたが, 20日齢では16種類, 他の日齢では7種類以下であった。また2剤以上の薬剤に耐性の多剤耐性型が約70%を占め, 特に20日齢では90%が多剤耐性型であり, 6剤型も本日齢のみで検出された。なお200日, 500日及び800日齢でも59∿77%が多剤耐性型であった。耐性菌314株における伝達性Rプラスミドの検索では, 60株(19.1%)がRプラスミドを保有していたが, うち47株は500日齢由来であった。300日, 400日及び800日齢ではRプラスミド保有菌が検出されなかった。これら菌株の伝達耐性型は単剤型から4剤型まで見られたが, 49株が単剤伝達型であり, 残りの2∿4剤伝達型は20日及び500日齢由来であった。, Fecal samples were collected from laying hens at various ages in a poultry farm in Okinawa Prefecture. A total of 826 strains of Escherichia coli were isolated from the samples and tested for sensitivity testing to 7 antibiotics. Transmissible R plasmid was investigated in the resistant strains. Three hundred and fourteen strains (38.0%) were resistant to at least one of the 7 antibiotics tested. The prevalence of resistant strains was highest in the 20-day-old group (86.9%) and lowest in the 600-day-old group (8.8%), with a tendency of decrease with age. However, the prevalence was still 51.7% in the 500-day-old group, the second highest after the 20-day-old group. The rate of SA resistance was highest at 29.7%, followed by SM, CTC, KM and ABPC, in that order. SA resistance was the highest or second highest in all age groups, but CTC resistance was the highest in the 200-and 400-day-old groups, and ABPC and SA resistance was high in the 800-day-old group. The order of resistance rate among antibiotics varied slightly with age. Twenty-three resistance patterns were detected ranging from single-agent to 6-agent resistance. Sixteen types were observed in the 20-day-old group and 7 types or less in the other age groups. Multiple resistance type, defined as resistance to 2 or more antibiotics, accounted for approximately 70%. In the 20-day-old group, particularly, 90% were of the multiple resistance type and 6-agent resistance was seen only in this age group. Transmissible R plasmid was investigated in 314 resistant strains. Sixty strains (19.1%) possessed R plasmid, 47 strains of which were from the 500-day-old group. No R plasmid possessing strain was detected in the 300-, 400-or800-day-old group., 紀要論文}, pages = {131--138}, title = {産卵鶏糞便由来大腸菌の薬剤耐性} }