{"created":"2023-06-19T07:18:08.467662+00:00","id":3262,"links":{},"metadata":{"_buckets":{"deposit":"07ee884e-e8ce-460d-8f2c-0d5928965e6a"},"_deposit":{"created_by":4,"id":"3262","owners":[4],"pid":{"revision_id":0,"type":"depid","value":"3262"},"status":"published"},"_oai":{"id":"oai:az.repo.nii.ac.jp:00003262","sets":["17:38:264","370:15:392"]},"author_link":["16356"],"item_10006_date_granted_11":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2000-07-24"}]},"item_10006_degree_grantor_9":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_name":"麻布大学"}]}]},"item_10006_degree_name_8":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"博士(獣医学)"}]},"item_10006_description_22":{"attribute_name":"Abstract","attribute_value_mlt":[{"subitem_description":"Rats and mice have long been known as a carriers or reservoirs of various kinds of infectious diseases such as plague, leptospirosis, rat-bite fever, salmonelosis, lassa fever, hemorrhagic fever with renal syndrome, and so forth and have played a role in the occurrence and epidemic of these diseases. Depending upon the habitat the rats were generally classified into commensal and feral rats and mice. Rats and mice infesting towns and cities were Norway rats (Rattus norvegicus), roof rats (R. rattus) and house mouse (Mus molossinus) in Japan. Rats and mice that inhabit human domiciles can contaminate food and transmit diseases. Among these three species, the Norway rat has been extensively investigated for its pathogen carrier state. They were a major reservoir of Leptospira in rural and city areas which was the cause of leptospirosis. Several hundred people died in a year a few decades ago. Norway rats were also the source of food contamination of Salmonella outbreak which occurred in 1935.\n On the other hand, in the past, the Norway rat was the most dominant species of rat inhabiting towns and cities. Recently, however, roof rats have increased and displaced Norway rats in large buildings with highly modernization of cities. Roof rats are adapted to a life of climbing and prefer an elevated location, living in upper floors, and are resistant of rodenticide. At present, it has been proved that the rats inhabiting buildings in cities are almost roof rats and they come out at night and rummage for something to eat in the kitchen of restaurants or food stores. Despite this, there have not been many reports on pathogenic bacteria in roof rat.\n The present study investigated the occurrence of etiological agents of various kinds of bacterial zoonoses in roof rats infesting buildings in downtown Tokyo. And also, the contamination of the environment (restaurants and so forth) in the buildings by these etiological agents and the relationship between the contaminations of rats and the environments in the buildings in downtown Tokyo were examined.\n\n I. Occurrence of zoonotic bacteria in roof rats infested at buildings in downtown Tokyo.\n During the period from 1988 to1992, a total of 1,374 roof rats were caught with glue traps, at restaurants and groceries in 16 buildings (A to P) in downtown Tokyo. The large intestinal contents of the rats were used for the isolation of Salmonella, Staphylococcus aureus, Listeria, Vibrio, Yersinia, and Campylobacter. The kidneys were for Leptospira. Cotton swabs of oral cavity were also used for S. aureus. Isolation, identification, and characterization such as biotype, serotype, plasmid pattern, and so forth were performed according to the usual methods.\n\n 1. Occurrence of Salmonella in roof rats\n Salmonella was isolated from 17 (1.5%) out of 1,144 roof rats in buildings. In 1960's, carrier rates of Salmonella in rats inhabited at the city area in Tokyo and Osaka were around 2%. These carrier rates of Salmonella from rats between this study and 1960's were almost equal. So, it was recognized that the carrier rate of Salmonella from rats hardly changed in comparison with the carrier rate 40years ago. Salmonella serotypes identified from 17 rats at the restaurants were S. Typhimurium (35.3%), S. Hadar (29.4%), S. Isangi (11.8%), S. Litchfield (11.8%), S. Enteritidis (5.9 %) and S. Senftenberg (5.9 %). The occurrence rates of Salmonella in retailed meat in Tokyo were 26.6% in chicken, 5.3% in pork, and 1.3% in beef. These meats might be regarded as one of the main sources of Salmonella contamination for the rats in the buildings. S. Typhimurium, S. Hadar, and S. Enteritidis are reported to be most frequent among strains isolated from the meats. They were also most predominant among the strains from the roof rats in the buildings in downtown Tokyo in this study, which was carried out in the nearly same period, suggesting the close link of the roof rats to the meats.\n\n 2. Occurrence of Staphylococcus aureus in roof rats\n 161(17.3%) out of 932 roof rats captured at restaurants in buildings in downtown Tokyo were positive for S. aureus. This carrier rate is lower than that of rats (35.7 to 84.5%) inhabiting other places or other animals (0 to 85.3%). This reflected the cleanliness of the buildings inhabited by these roof rats.\n The 165 S. aureus strains isolated were biotyped into A, B, C, D, G and untypable groups (UT1 and UT2). It was observed that UT1 (58.9%) which was an intermediate type between rodent type (biotype G) and human type (biotype A) was the more predominant than biotype G that had frequently been detected in mice and rat. The strains were classified into coagulase types I, II, III, IV, V, VI, VII, VIII, and untypable group. Coagulase type V (55.9%) that has been detected from the particular lesion of impetigo in humans with high frequency was the most frequent, followed by coagulase type VII (15.5%) that has been most predominant type isolated from patient of staphylococcal food poisoning. 41 strains produced enterotoxins. S. aureus strains isolated in case of food poisoning mostly produced enterotoxin A, B and C. In this study, 87.8% of 41 strains produced enterotoxins A, B and C. Toxic shock syndrome toxin-1 was produced by 3 strains.\n These findings suggested that rats in the buildings might be regarded as one possible source of staphylococcal food poisoning.\n\n 3. Occurrence of Listeria in roof rats\n Listeria was isolated from 133 of 692 (19.2%) roof rats in the buildings. This isolation rate is higher than those of rats (0-9.4%) inhabiting other places and of other animals (0-12.2%). L. monocytogenes which is pathogen and cause of listeriosis was isolated from 43 of 410 (10.5%). This isolation rate is remarkably higher than those of rats (0-3.6%) inhabiting other places and of other animals (0-1.4%). The predominant serotypes of L. monocytogenes from roof rats were 4b, 1/2b, and 1/2a. These serotype strains are frequently detected from patient of human listeriosis.\n Therefore, these findings suggested that rats in the buildings might be regarded as one possible source of listeriosis through foods, though it became clear that listeriosis is a food-borne infection, only recently.\n\n 4. Occurrence of Vibrio in roof rats\n 67 (13.4%) out of 500 roof rats captured at restaurants in 13 buildings in downtown Tokyo were positive for Vibrio. Among the rats infesting buildings, the incidence of Vibrio from rats (20.0%, 51/255) in groceries (mainly fish shops) was significantly higher than those (6.5%, 16/245) in restaurants. There were also more kinds of Vibrio from rats in groceries than rat in the restaurants. Therefore, these suggested that fresh fish and shellfish carried into buildings were source of contamination of Vibrio to the rats.\n V. parahaemolyticus, which is halophilic Vibrio, was only detected from rats in groceries. The detection rate was comparatively low (3.1%). 38 strains of V. parahaemolyticus from eight rats at groceries were classified into 26 serotypes. One to eight different serotypes from each rat were detected. These results suggested that fresh fish and shellfish carried into buildings from wide areas of the sea throughout the world and V. parahaemolyticus could not survive in the rats and environment of the buildings.\n On the other hand, V. cholerae non-O1, which is terrestrial Vibrio, was detected at almost the same rate from rats in groceries and restaurants. 41 strains of V. cholerae non-O1 were classified into only 16 serovars. Among them, serotype O108 was most predominant (19.5%) followed by serotype O107, O109. These serotypes isolated in this study were added as new serotypes. The change by time of serotypes for V. cholerae non-O1 from rats at groceries was observed. The same specific serovars of V. cholerae non-O1 were kept for at least one month in the mass of rats in buildings.\n The incidence in summer season (June, July, and August) was significantly higher than that in the other seasons (P<0.01).\n Therefore, the roof rats in the buildings have kept V. cholerae non-O1 and might be one possible source of contamination for foods.\n\n 5. Occurrence of Yersinia in roof rats\n Yersinia spp. were isolated from 341 of 1161 roof rats (29.8%); Y. enterocolitica from 173 rats (15.0%), Y. frederiksenii from 180 rats (15.5%), Y. intermedia from 49 rats (4.2%) and Y. kristensenii from 12 rats (1.0%). Of 175 isolates of Y. enterocolitica, 16 were of serotype O:5 (biotype 1, 8strains) and O:7,8 (biotype 1, 8 strains). None of the Y. enterocolitica isolates were of pathogenic serotype and biotype and they had no pathogenic plasmids.\n Therefore, though the roof rats and habitat in the buildings were highly contaminated by environmental (non-pathogenic) Yersinia, it is thought that pathogenic Yersinia that are carried with contaminated pork could not come to contaminate the roof rats and habitat in the building.\n\n 6. Occurrence of Campylobacter in roof rats\n Campylobacter was isolated from none of 545 rats in the buildings. Campylobacter has been isolated from 16 (17.6%) of 91 Norway rats in the sewer of Lyon, France, from 49 (19.5%) of 251 Norway rats in the port of Nagoya, Japan, and from 1 (1.1%) of 94 Norway rats in the coastal area of Tokyo. In this study, Campylobacter was detected from the Norway rats in the fish market but not from the roof rats at the restaurants in buildings in downtown Tokyo. This difference in the isolation rate of Campylobacter between Norway and roof rats may reflect the followings; roof rats like to live in relatively dry environments such as in tall buildings, but Norway rats prefer to live in moist environments such as sewer and basement; and also Campylobacter tends to diminish rapidly in a dry environment at relatively high temperature such as in buildings in cities.\n\n 7. Occurrence of Leptospira in roof rats\n Carrier state of Leptospira in rats has mainly been investigated for rats inhabiting rural areas, and these carrier rates of Leptospira reported were 11 to 70 %. Until 1970's, the reported carrier rates of Norway rats in sewer and restaurants in downtown Tokyo have been 20 to 25%, and it was recorded that more than 10 people had died from leptospirosis in one year. In this study, no Leptospira was isolated from 564 roof rats in buildings though it was examined in detail by cultivation on isolation medium and inoculation into guinea pig with emulsion kidney of rats and so forth. And all serum titer of roof rats were showed less than 10 fold. According to these results, Leptospira rarely infected the roof rats and was not maintained in roof rats inhabited buildings, because Leptospira is transmitted through water, and expelled by the dry environment in the building.\n Therefore, it could be thought that the opportunities for the roof rats to be infected with Leptospira from drain and so forth and to maintain the Leptospira were decreased remarkably because Leptospira was ordinarily transmitted through water-born infection and the roof rats inhabited modern buildings that are comparatively dry.\n\n Considering the circumstances mentioned above, results of isolation rates of various kind of zoonotic bacteria in roof rats inhabiting the buildings in downtown Tokyo are as follows. Isolation rates of Salmonella and S. aureus in roof rats were almost equal to those in Norway rats, those of Campylobacter and Leptospira was decreased remarkably and non of these bacteria could be isolated, whereas those of Listeria, Vibrio, Yersinia were remarkably high. Especially, for L. monocytogenes, the characteristic recognized was that isolation rates of L. monocytogenes in the roof rats in the buildings were much higher than other rats or animals.\n Therefore, in the next chapter, the state of Listeria contamination in environment of the buildings was investigated to make the cause of high detection rate of Listeria from roof rats in buildings clear.\n\n II. Occurrence of Listeria in roof rats and the environment of their habitat\n During the period from 1994 to1995, a total of 183 large intestinal contents of 183 roof rats trapped at restaurants in 3 buildings (Q to S) in downtown Tokyo and 237 swabbing samples of their inhabiting environments were examined for isolation of Listeria. The isolates were identified for species. The serotype and DNA type of L. monocytogenes strains identified were determined.\n\n 1. Occurrence of Listeria at each buildings\n The detection rates of Listeria spp. in the rats and their habitats were highest in Building R at 52.0% and 35.5%, respectively, followed by Building Q (29.6% and 23.5%, respectively) and Building S (14.8% and 4.4%, respectively). Therefore, there was a positive correlation between the detection rates of Listeria in the rats and those of their habitats: the higher the detection rate of Listeria in the rats, the higher the detection rate in their habitats.\n It was also recognized that there was a positive correlation between the ratios of L. monocytogenes positive specimens to L. innocua positive specimens in the rats and those in their habitats. These differed from one building to the next, but were comparable within the same building. The states of Listeria contamination in the rats and their habitats were also similar on the same floor in Building Q.\n\n 2. Serovars and RAPD types of L. monocytogenes isolated from rats and their habitat environment\n The serotype and RAPD type of L. monocytogenes in the rats and their habitats varied from floor to floor and from building to building. But the serotype and RAPD type of L. monocytogenes isolated were similar and a positive correlation between the rats and their habitat within the same building or the same floor.\n On the other hand, though L. monocytogenes could not colonize in the intestine of rats, L. monocytogenes could survive in a humid environment for a long time. It can be concluded that Listeria spp. survive for a fairly long time in closed environments, such as restaurants in the buildings and that rats inhabiting the buildings are exposed to Listeria spp. through contaminated environments more than through contaminated food. The rats that inhabit the building reflect the state of the environmental contamination, and encourage the expansion of environmental contamination through the feces or mechanical transportation of the source of contamination. And it was suggested that the territory of the rats in the buildings were limited within one building or one floor.\n\n Conclusion\n In this study, the occurrence of zoonotic bacteria in the roof rats adapted to environment in the buildings of modernized cities were investigated. The roof rats infesting the buildings in downtown Tokyo carried the pathogenic bacteria, such as L. monocytogenes, V. cholerae non-O1, S. aureus, Salmonella and so forth, that were recognized to be maintained in special environments of the modernized buildings in place of the pathogens for leptospirosis, rat-bite fever, hemorrhagic fever with renal syndrome and so forth, of which rats are the original host and had been detected from Norway rats in the past. So, rats in buildings play a role in spreading the pathogens in the environments.\n From these mentioned, one aspect of the ecology of pathogens involving the rats and their habitat in buildings in modernized cities was cleared."}]},"item_10006_description_7":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"ネズミは、ペスト、レプトスピラ症、鼠咬症、サルモネラ症、ラッサ熱、腎症候性出血熱など様々な疾病の病原巣あるいは媒介者として知られ、これらの疾病の発生あるいは流行の原因となってきた。ネズミは、その生活圏の違いから一般にイエネズミとノネズミに分けられている。イエネズミには、クマネズミ、ドブネズミ、ハツカネズミの3種があり、ヒトの生活圏に生息することから住家性ネズミとも言われ、ヒトと密接に係わっている。この3種のなかでも、特にドブネズミは、かって日本の田園および都市において年間数百人の死者を出したレプトスピラ症の主要な病原巣であり、また、1935年に発生したサルモネラ食中毒（大福餅事件）の汚染源であったことなどにより、一躍注目を浴び多くの調査がなされてきた。\n　一方、近年都市の近代化が著しく進み、都市環境の急激な変化と共に、そこに生息するネズミの生態にも大きな変化が起こっている。すなわち、1970年代に入ると、それまで優勢であったドブネズミに代わって、乾燥に強く、殺鼠剤に抵抗性で、垂直移動を好むクマネズミが優勢となり、今日では、都市のビル内に生息しているネズミのほとんどはクマネズミであることが明らかにされている。\n　本研究は、これまでに不明であったこのように近代都市のビル内に生息するようになり、猖獗を極めているクマネズミにおける各種人獣共通感染症原因細菌の保有状況をはじめて明らかにし、さらにビル内環境（飲食店など）における汚染状況を調べ、ネズミと環境汚染の関連性について検討した。\n\n　I. 都市のビル内のクマネズミにおける人獣共通感染症原因細菌の保有状況\n　1988～1992年に、東京都心部の16のビル内で捕獲したクマネズミ1.191匹（大腸内容物など）を供試し、各種人獣共通感染症原因細菌の分離培養を行い、分離菌株の種の同定、生物型、血清型、プラスミド型、DNA型などの各種型別、病原因子の試験などを実施した。\n\n　1. Salmonellaの保有状況\n　ビル内のクマネズミにおけるSalmonellaの保有率は1.5%（17/1144）で、1960年代の東京および大阪の市街地のネズミにおける保有率約2%とほぼ同率であり、40年前とほとんど変化が認められなかった。また、出現血清型はTyphimurium（35.3%）、Hadar（29.4%）、Isangi（11.8%）、Enteritidis（11.8%）などが高頻度で検出された。本研究と同時期の都心部のビル内小売り食肉におけるSalmonellaの汚染率は鶏肉26.6%、豚肉5.3%、牛肉1.3%であり、血清型は今回のネズミと同様の血清型が高頻度で検出されている。したがって、都市のネズミのSalmonella保有状況はこれらの食肉の汚染状況を反映していることが示唆された。\n\n　2. S.aureusの保有状況\n　ビル内のクマネズミにおけるS. aureusの保有率は17.3%（161/932）で、既報の他の場所に生息するネズミ（35.7～84.5%）や他の動物（0～85.3%）の保有率に比較してかなり低率であった。ビル内環境の清浄さを反映していると考えられた。\n　分離菌の生物型は、これまでネズミなどの齧歯類から多く検出される齧歯類型（G型）よりも、齧歯類型（G型）とヒト型（A型）の中間型（UT1）が58.9%と圧倒的に多いという特徴が認められた。コアグラーゼ型については、ヒトの膿痂疹などの臨床由来株に多いV型（55.9%）、次いで食中毒患者から最も頻繁に分離されるVII型（31.8%）の2型が最優勢であった。分離菌161株のうち41株（25.5%）がエンテロトキシンを産生し、しかもヒト食中毒の原因菌として頻度が高いエンテロトキシンA、B、C産生株が87.8%を占めた。3株（1.9%）がTSST-1を産生した。したがって、都市のネズミのS. aureusはヒト型あるいはヒト食中毒由来株に類似の性状を示す傾向が認められた。食中毒の汚染源になっている可能性が示唆された。\n\n　3. Listeriaの保有状況\n　ビル内のクマネズミにおけるListeria ssp.の保有率は19.2%（133/692）で、既報の他の場所に生息するネズミ（0～9.4%）や他の動物（0～12.2%）における保有率に比較してかなり高率であった。また、菌種別にみた場合、リステリア症の原因菌は病原牲L. monocytogenesの保有率は10.5%（43/410）で、既報の他の場所に生息しているネズミ（0～3.6%）や他の動物（0～1.4%）における保有率に比較して著しく高率であり、さらに、L. monocytogenesの分離株の血清型はヒトの病原性3大血清型として知られている1/2a、1/2b、4bが圧倒的に多く、91.7%を占めるなどの顕著な特徴が認められた。従って、近年リステリア症は食品媒介性であることが明らかになりつつあるが、都市のクマネズミが飲食店の食品を介して感染源になってる可能性が示唆された。\n\n　4. Vibrioの保有状況\n　ビル内のクマネズミにおけるVibrio spp.の保有率は13.4%（67/500）であった。このうち主に生鮮魚介類を販売している食品店では20.0%（51/255）で、飲食店での6.5%（16/245）より有意義（P<0.01）に高率であり、しかも、より多くの菌種（6種）が検出されることなどから、ビル内に搬入される生鮮魚介類がビル内のネズミの主な汚染源であることが示唆された。\n　好塩性の腸炎ビブリオ（V. parahaemolyticus）は食品店のネズミのみから比較的低率（3.1%）で検出されたが、分離菌38株は26血清型に型別され、また、1匹のネズミから8種の異なる血清型が検出される例がみられることなど変化にとみ、世界の広い海域の生鮮魚介類がビル内に搬入されていることが示唆されると共に、本菌はビル内のネズミや環境で生存できないと考えられた。\n　これに対して、淡水性のV. cholerae non-O1は、食品店および飲食店のネズミの両者からほぼ同率（7.5%と4.5%）で検出され、分離菌41株は比較的少ない16血清型に型別されるのみで変化に乏しく、また特定の血清型（本研究で初めて発見、追加された0107、0108、0109など）が約一ヶ月間継続して同一の食品店から検出されることなどから、V. cholerae non-O1はネズミの腸管内あるいはビル内環境でかなり長期間生存でき、汚染が維持されていると考えられた。\n　ビル内のネズミにおけるVibrio spp.の保有率には海産魚介類の場合と同様に季節差が認められ、夏季で25.8%（49/190）と高率であったが、冬季では、1.9%（1/52）と著しく低率であった。したがって、都市のネズミはV. cholerae non-O1の特定の血清型を選択的に保有し、食品の汚染源になっている可能性が示唆された。\n\n　5. Yersiniaの保有状況\n　ビル内のクマネズミにおけるYersinia spp.の保有率は29.4%（341/1161）で、過去に報告されている都市の下水道のドブネズミにおける保有率（1/3～20.5%）よりもむしろ高率であった。出現菌種は、5菌種で、そのうち病原性（食中毒菌）のY. enterocolitica（173株、14.9%）および非病原性のいわゆる環境エルシニアと呼ばれるY. frederiksenii（180株、15.5%）の2菌種が最優勢であった。しかし、Y. enterocoliticaの分離菌はいずれも病原因子（45Mdプラスミド、カルシュウム要求性、自己凝集性など）が全て陰性で、環境エルシニア化していると考えられた。したがって、ビル内のネズミと環境は環境エルシニアによってかなり高率に汚染されていて、病原性Y. enterocoliticaなどが汚染豚肉などとともにビル内に侵入しても、ネズミや環境を汚染するまでに至らないと考えられた。\n\n　6. Campylobacterの保有状況\n　都市のネズミにおけるCampylobacterの保有状況についてはこれまで主にドブネズミについて調べられており、保有率として下水道17.6%、港湾地域1.1%などが報告されている。今回ビル内のクマネズミ545匹について調べたが、全て陰であった。\n　一方、東京都区内の小売り食肉におけるCampylobacterの汚染率として鶏肉77.2%、牛肉5.1%、豚肉1.4%などが報告されている。このような汚染食肉とともにCampylobacterがビル内に持ち込まれても、衛生的に管理されるとともに、比較的乾燥したビル内環境では死滅しやすく、ビル内のネズミを汚染することは少ないと考えられた。\n\n　7. Leptospriaの保有状況\n　ネズミにおけるLeptospriaの保有はこれまで主に田園地域のネズミについて調査されており、11～70%の保有率が報告されている。また、1970年代までの東京都区内の下水道や飲食店のドブネズミにおいて20～25%の保有率が報告され、都市だけでも年間10名以上の死亡が記録されていた。今回、都心部のビル内のクマネズミ564匹にちて腎臓乳剤のモルモット接種などを行って精査したがLeptospriaは全く検出されず、また、血中抗体価も全て10倍以下であった。したがって、Leptospriaは本来水系感染によって伝搬するため、比載的乾燥した近代ビル内に生息するクマネズミが、下水道などからのLeptospriaに感染し、それを持続する機会は非常に少なくなっているものと考えられた。\n\n　以上、東京都心部のビル内に生息するクマネズミにおける各種病原細菌の保有状況を調べた結果、SalmonellaとS.aureusについては従来の都市のドブネズミにおける保有率とほぼ同様であったが、CampylobacterとLeptospriaについては著しく減少し、全く検出されなかった。しかし、Listeria、Vibrio、およびYersiniaは著しい高率を示し、特にL. monocytogenesについては他のいずれの動物における保有率よりも際だって高率であるという顕著な特徴が認められた。そこで、このビル内ネズミにおけるL. monocytogenesの高率保有の原因を探るため、次項においてビル内環境におけるListeria汚染について調べた。\n\n　II. 都市のビル内のクマネズミとその生息環境におけるListeriaの汚染状況\n　1994～1995年に3つのビル（Q、R、S）で捕獲されたクマネズミ183匹の腸内容183検体およびその生息環境（飲食店厨房の床面と排水溝）の拭き取りスワブ243検体を供試し、Listeriaの分離培養と分離株の菌種の同定、血清型別およびDNA型別をおこなった。\n\n　1. 各ビルにおけるListeriaの汚染率\n　3つのビルにおけるネズミと環境のListeria汚染率を比較すると、Rビルでは両汚染率共に最も高くそれぞれ52.0%、35.5%、Sビルでは共に最も低く14.8%、4.4%、Qビルは共にRビルとSビルの中間値29.6%、23.5%であった。従って、ネズミと環境の両汚染率は、ネズミで高い場合環境でも高く、ネズミで低い場合環境でも低いというビル間の変化に明瞭な並行関係が認められた。この並行関係は、出現菌種のL. monocytogenesとL. innocuaの汚染率についても明瞭に認められ、さらに、Qビルの各階においても同様であった。\n\n　2. L. monocytogenesの血清型およびRAPDタイプ\n　ネズミと環境におけるL. monocytogenesの出現血清型の種類とその検出率、またDNAのRAPDタイプは、いずれも各ビル間あるいQビル各階の間で著しく異なっているが、同一のビルあるいはQビルの同一の階では両者間に明瞭な並行関係あるいは類似性が認められた。\n　一方、これまでにL. monocytogenesはラットの腸管に定着できないが、湿潤な環境には長期間生存できることが明らかにされている。したがって、特定の血清型やRAPDタイプが特定のビルあるいは階を汚染、定着し、そこに生息するネズミはこの環境汚染状況を反映してListeriaを保菌し、環境汚染の拡大を助長していることが強く示唆された。また、ビル内のネズミの行動範囲（テリトリー）は同一の階のあるいは同一のビル内などにかなり限定されていることが強く示唆された。\n\n　本研究は、これまでほとんど不明であった近代都市環境に適応し隆盛を極めているクマネズミにおける各種病原細菌の汚染状況を初めて明らかにしたもので、その汚染状況は、かってのドブネズミにおけるレプトスピラ症、鼠咬症、腎症候性出血熱などのようなネズミを本来の宿主とする疾病の病原微生物によるものではなく、これらに代わって、L. monocytogenes、V. cholerea non-O1、S. aureusあるいはSalmonellaなどのような近代ビル内の特殊環境で生存あるいは定着していると考えられる病原細菌によって逆に汚染され、ネズミはこれらの環境汚染病原細菌の拡大者（spreader）としての役割を果たしていることを強く示唆する成績を得、近代都市環境とそこに生息するクマネズミに関わる病原細菌の新しい生態の一面を明らかにした。"}]},"item_10006_dissertation_number_12":{"attribute_name":"学位授与番号","attribute_value_mlt":[{"subitem_dissertationnumber":"乙第383号"}]},"item_10006_version_type_18":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_ab4af688f83e57aa","subitem_version_type":"AM"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"加藤, 行男"},{"creatorName":"Kato, Yukio","creatorNameLang":"en"}],"nameIdentifiers":[{},{},{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2013-02-20"}],"displaytype":"detail","filename":"diss_dv_otsu0383.pdf","filesize":[{"value":"5.3 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"diss_dv_otsu0383","url":"https://az.repo.nii.ac.jp/record/3262/files/diss_dv_otsu0383.pdf"},"version_id":"ef15ae91-1bfd-4209-a8c5-514480f0f242"},{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2014-08-18"}],"displaytype":"detail","filename":"diss_dv_otsu0383_jab&rev.pdf","filesize":[{"value":"487.0 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"diss_dv_otsu0383_jab&rev","url":"https://az.repo.nii.ac.jp/record/3262/files/diss_dv_otsu0383_jab&rev.pdf"},"version_id":"cce04591-0342-45aa-9edb-f7f736fb3bfe"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"thesis"}]},"item_title":"都市のビル内に生息するクマネズミにおける人獣共通感染症原因細菌に関する研究","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"都市のビル内に生息するクマネズミにおける人獣共通感染症原因細菌に関する研究"},{"subitem_title":"Studies on zoonotic bacteria in rats inhabiting the buildings in downtown Tokyo","subitem_title_language":"en"}]},"item_type_id":"10006","owner":"4","path":["264","392"],"pubdate":{"attribute_name":"公開日","attribute_value":"2013-02-13"},"publish_date":"2013-02-13","publish_status":"0","recid":"3262","relation_version_is_last":true,"title":["都市のビル内に生息するクマネズミにおける人獣共通感染症原因細菌に関する研究"],"weko_creator_id":"4","weko_shared_id":4},"updated":"2023-06-19T08:16:12.766916+00:00"}