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STEPHEN C. AYALA 《The Journal of eukaryotic microbiology》1971,18(3):433-436
SYNOPSIS. Trypanosomes were found in 94 of over 1,600 wild Lutzomyia vexatrix occidentis, a common phlebotomine sandfly in central California; 25% of the infected sandflies harbored T. bufophlebotomi, identifiable by its peculiar kinetoplast and body structure. The toad trypanosome was cultured from insect isolates and freeze-preserved. Growth in culture occurred at 23 C, but not at 15 C or 30 C. The other 75% of trypanosomes from wild sandflies remain unidentified, altho some were probably T. scelopori or T. gerrhonoti of lizards. 相似文献
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To determine geographical patterns of natural parasite infections among wild rodents, a total of 46 wild rodents from 3 different localities in northern Gangwon-do (Province), Korea were examined for intestinal parasite infections. Along with nematodes such as hookworms and Syphacia spp., Plagiorchis muris (2 specimens) (Trematoda) were collected from striped field mice, Apodemus agrarius. In a Korean wood mouse, Apodemus peninsulae, the overall nematode infections were similar to A. agrarius, but an adult worm of Echinostoma hortense (Trematoda) was collected. In addition, 2 species of cestodes, i.e., Hymenolepis nana and Hymenolepis diminuta, were collected from A. agrarius. Through this survey, A. agrarius and A. peninsule were confirmed as the natural definite hosts for zoonotic intestinal helminths, i.e., P. muris, E. hortense, H. nana, and H. diminuta, in northern Gangwon-do, Korea. Considering increased leisure activities around these areas, seasonal and further comprehensive surveys on wild rodents seem to be needed to prevent zoonotic parasite infections. 相似文献
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Verocytotoxin-Producing Escherichia coli in Wild Birds and Rodents in Close Proximity to Farms 下载免费PDF全文
Eva Mller Nielsen Marianne N. Skov Jesper J. Madsen Jens Lodal Jrgen Brchner Jespersen Dorte L. Baggesen 《Applied microbiology》2004,70(11):6944-6947
Wild animals living close to cattle and pig farms (four each) were examined for verocytotoxin-producing Escherichia coli (VTEC; also known as Shiga toxin-producing E. coli). The prevalence of VTEC among the 260 samples from wild animals was generally low. However, VTEC isolates from a starling (Sturnus vulgaris) and a Norway rat (Rattus norvegicus) were identical to cattle isolates from the corresponding farms with respect to serotype, virulence profile, and pulsed-field gel electrophoresis type. This study shows that wild birds and rodents may become infected from farm animals or vice versa, suggesting a possible role in VTEC transmission. 相似文献
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鼠类对山杏和辽东栎种子的贮藏 总被引:11,自引:2,他引:11
在北京市东灵山地区,选择灌丛生境,人工释放山杏和辽东栎种子,对两种种子在释放处被鼠类就地取食、存留动态、种子被搬运和贮藏的距离、位置、状态、微生境等进行了分析比较。采用活捕饲喂和咬痕比较的方法,对野外取食山杏和辽东栎种子的鼠类进行了鉴定。结果表明:1)取食山杏和辽东栎种子的鼠类主要是大林姬鼠和岩松鼠;2)山杏种子被鼠类搬运的平均距离大于辽东栎种子,两种种子大多数被搬运至21m之内,在9m之内最为集中;3)山杏种子的中位存留时间较辽东栎种子长;4)在释放处,鼠类对辽东栎种子的就地取食强度(54.83%)大于对山杏种子的取食(0.17%);5)在搬运之后,大部分山杏种子被埋藏起来,仅有3粒被取食;而辽东栎种子大部分被取食;6)鼠类趋向于把种子搬运到灌丛下方或灌丛边缘进行贮藏或取食。山杏种子在贮藏点的数量为1—3粒,而辽东栎种子在贮藏点的数量均为1粒。 相似文献
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Prevalence and Genetic Diversity of Bartonella Species Isolated from Wild Rodents in Japan 下载免费PDF全文
Kai Inoue Soichi Maruyama Hidenori Kabeya Naoyuki Yamada Norio Ohashi Yukita Sato Masayoshi Yukawa Toshiyuki Masuzawa Fumihiko Kawamori Teruki Kadosaka Nobuhiro Takada Hiromi Fujita Hiroki Kawabata 《Applied microbiology》2008,74(16):5086-5092
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Juozas Nainys Albertas Timinskas Julia Schneider Rainer G. Ulrich Alma Gedvilaite 《PloS one》2015,10(10)
Two novel polyomaviruses (PyVs) were identified in kidney and chest-cavity fluid samples of wild bank voles (Myodes glareolus) and common voles (Microtus arvalis) collected in Germany. All cloned and sequenced genomes had the typical PyV genome organization, including putative open reading frames for early regulatory proteins large T antigen and small T antigen on one strand and for structural late proteins (VP1, VP2 and VP3) on the other strand. Virus-like particles (VLPs) were generated by yeast expression of the VP1 protein of both PyVs. VLP-based ELISA and large T-antigen sequence-targeted polymerase-chain reaction investigations demonstrated signs of infection of these novel PyVs in about 42% of bank voles and 18% of common voles. In most cases only viral DNA, but not VP1-specific antibodies were detected. In additional animals exclusively VP1-specific antibodies, but no viral DNA was detected, indicative for virus clearance. Phylogenetic and clustering analysis including all known PyV genomes placed novel bank vole and common vole PyVs amongst members of the tentative Wukipolymavirus genus. The other known four rodent PyVs, Murine PyV and Hamster PyV, and Murine pneumotropic virus and Mastomys PyV belong to different phylogenetic clades, tentatively named Orthopolyomavirus I and Orthopolyomavirus II, respectively. In conclusion, the finding of novel vole-borne PyVs may suggest an evolutionary origin of ancient wukipolyomaviruses in rodents and may offer the possibility to develop a vole-based animal model for human wukipolyomaviruses. 相似文献
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North MJ 《Parasitology today (Personal ed.)》1991,7(9):249; author reply 249
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Comunian LB Moura SB Paglia AP Nicoli JR Guerra JB Rocha GA Queiroz DM 《Current microbiology》2006,53(5):370-373
Since we have limited knowledge about the occurrence of Helicobacter in wild animals, we searched for Helicobacter species in the gastrointestinal tract of 75 rodents captured in forest remnants of Minas Gerais, Brazil. Fragments from the
antrum and corpus of the stomach and from the colon were taken for PCR assays for Helicobacter detection. Although gastric mucosa was Helicobacter-positive in only one animal, the bacterium was detected in the colonic mucosa of 23 rodents (30.7%). Helicobacter detection was more frequent in the colon of terraced rice rat (56%) and house rat (30%) in contrast to punare and Spix’s
yellow-toothed cavy, in which the presence of the bacterium was not detected. Helicobacter rodentium, H. marmotae, H. cinaedi, and other species closely related to the murine helicobacters were presumptively identified by DNA sequencing. Wild rodents
may serve as a reservoir of these Helicobacter species in nature. 相似文献
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Fubito Ishiguro Nobuhiro Takada Yasuhiro Yano Masashi Harada Toshiyuki Masuzawa Hidetada Iida 《Microbiology and immunology》1995,39(6):419-424
Field rodents serve as a reservoir for Lyme disease spirochetes. To evaluate the antibody responses of rodents against different Borrelia species in relation to fauna of vector ticks feeding on them, we examined 272 sera of wild rodents, Apodemus speciosus, A. argenteus, and Eothenomys smithii, obtained in 27 locations in central and western Japan from 1981 to 1994. As to prevalences by rodent species using immunoperoxidase test, A. speciosus, A. argenteus and E. smithii showed 29.4%, 11.6% and 30.8% reactivity to Borrelia japonica, 10.7%, 7.2% and 3.8% to B. afzelii, 0.6%, 1.4% and 0% to B. garinii, and 14.7%, 7.2% and 11.5% to an unknown Borrelia species designated as It type, respectively. Each antibody to B. japonica, B. afzelii and B. sp. It type was detected widely both in central and western Japan, but the antibody to B. garinii was scarcely detectable in any area and rodent species examined. Apodemus mice in high mountain altitudes tend to have antibody to B. afzelii or B. japonica, and those in lower altitudes tend to have B. japonica or B. sp. It type. All 13 Apodemus mice from which B. japonica or B. sp. It type were isolated showed higher titers of antibodies to each homologous Borrelia species. The present results indicate that these antibody prevalences among rodents may be associated with dominant Ixodes ovatus and sporadic I. persulcatus on the mainland of Japan, and that Apodemus mice may not be an efficient reservoir for B. garinii. Such a serosurvey is a useful measure to evaluate the natural distribution of the pathogen. 相似文献
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Juha Song C-Yoon Kim Seo-Na Chang Tamer Said Abdelkader Juhee Han Tae-Hyun Kim Hanseul Oh Ji Min Lee Dong-Su Kim Jong-Taek Kim Hong-Shik Oh Moonsuk Hur Jae-Hwa Suh Jae-Hak Park 《The Korean journal of parasitology》2015,53(6):737-743
In order to examine the prevalence of Cryptosporidium infection in wild rodents and insectivores of South Korea and to assess their potential role as a source of human cryptosporidiosis, a total of 199 wild rodents and insectivore specimens were collected from 10 regions of South Korea and screened for Cryptosporidium infection over a period of 2 years (2012-2013). A nested-PCR amplification of Cryptosporidium oocyst wall protein (COWP) gene fragment revealed an overall prevalence of 34.2% (68/199). The sequence analysis of 18S rRNA gene locus of Cryptosporidium was performed from the fecal and cecum samples that tested positive by COWP amplification PCR. As a result, we identified 4 species/genotypes; chipmunk genotype I, cervine genotype I, C. muris, and a new genotype which is closely related to the bear genotype. The new genotype isolated from 12 Apodemus agrarius and 2 Apodemus chejuensis was not previously identified as known species or genotype, and therefore, it is supposed to be a novel genotype. In addition, the host spectrum of Cryptosporidium was extended to A. agrarius and Crosidura lasiura, which had not been reported before. In this study, we found that the Korean wild rodents and insectivores were infected with various Cryptosporidium spp. with large intra-genotypic variationa, indicating that they may function as potential reservoirs transmitting zoonotic Cryptosporidium to livestock and humans. 相似文献
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Chaochao Lv Longxian Zhang Rongjun Wang Fuchun Jian Sumei Zhang Changshen Ning Helei Wang Chao Feng Xinwei Wang Xupeng Ren Meng Qi Lihua Xiao 《Applied and environmental microbiology》2009,75(24):7692-7699
To understand the prevalence of Cryptosporidium infection in rodents in China and to assess the potential role of rodents as a source for human cryptosporidiosis, 723 specimens from 18 rodent species were collected from four provinces of China and examined between August 2007 and December 2008 by microscopy after using Sheather''s sugar flotation and modified acid-fast staining. Cryptosporidium oocysts were detected in 83 specimens, with an overall prevalence of 11.5%. Phodopus sungorus, Phodopus campbelli, and Rattus tanezumi were new reported hosts of Cryptosporidium. The genotypes and subtypes of Cryptosporidium strains in microscopy-positive specimens were further identified by PCR and sequence analysis of the small subunit rRNA and the 60-kDa glycoprotein (gp60) genes. In addition to Cryptosporidium parvum, C. muris, C. andersoni, C. wrairi, ferret genotype, and mouse genotype I, four new Cryptosporidium genotypes were identified, including the hamster genotype, chipmunk genotype III, and rat genotypes II and III. Mixed Cryptosporidium species/genotypes were found in 10.8% of Cryptosporidium-positive specimens. Sequence analysis of the gp60 gene showed that C. parvum strains in pet Siberian chipmunks and hamsters were all of the subtype IIdA15G1, which was found previously in a human isolate in The Netherlands and lambs in Spain. The gp60 sequences of C. wrairi and the Cryptosporidium ferret genotype and mouse genotype I were also obtained. These findings suggest that pet rodents may be potential reservoirs of zoonotic Cryptosporidium species and subtypes.Cryptosporidium spp. are protozoan parasites that infect a wide range of vertebrates, including humans. Cryptosporidiosis is acute and self-limiting in immunocompetent hosts but life threatening in immunocompromised individuals (48). Humans and animals can acquire Cryptosporidium infection through direct contact with infected individuals or contaminated fomites or by consumption of contaminated food or water (16, 47). Rodents, which are abundant and widespread, have been considered reservoirs of cryptosporidiosis in humans and farm animals. Previous studies based on oocyst morphology showed that many wild rodents might serve as hosts of Cryptosporidium parvum-like and C. muris-like parasites (4, 8, 42). The reported prevalence rates of Cryptosporidium in rodents ranged from 5.0% to 39.2% (11-13). Nearly 40 rodent species belonging to 11 families (Sciuridae, Muridae, Cricetidae, Castoridae, Geomyidae, Hystricidae, Erethizontidae, Myocastoridae, Caviidae, Hydrochoeridae, and Chinchillidae) have been reported as hosts of Cryptosporidium spp. (10, 12, 30, 53).Recently, PCR-based genotyping and subtyping tools have been used in assessing the human-infective potential of Cryptosporidium spp. in animals and the extent of cross-species transmission of cryptosporidiosis in animals (47, 49, 51). Five Cryptosporidium species and nearly 20 Cryptosporidium genotypes of uncertain species status have been identified in rodents worldwide in recent studies (3, 6, 12, 13, 18-20, 23, 26, 30, 31, 36, 39, 52, 53). Among them, C. parvum, C. meleagridis, cervine genotype, C. muris, C. andersoni, chipmunk genotype I, and skunk genotype have been associated with cryptosporidiosis in humans although the last four species and genotypes are each responsible for only one or a few cases (47). Subtyping based on sequence analysis of the 60-kDa glycoprotein (gp60) gene has been used in tracking the transmission of six Cryptosporidium species and genotypes, including C. hominis, C. parvum, C. meleagridis, C. fayeri, and the rabbit and horse genotypes (7, 37). There are at least 10 gp60 subtype families of C. parvum, two (IIa and IId) of which are involved in zoonotic transmission. In rodents, natural C. parvum infection is rare (11), and only one C. parvum subtype (IIaA15G2R1) has been reported in capybaras (Hydrochoerus hydrochaeris) in Brazil (30).Until recently there has been no genetic characterization of Cryptosporidium spp. in rodents in China. Worldwide, there are also hardly any genetic data on Cryptosporidium spp. from pet rodents. The purpose of this study was to determine the prevalence of Cryptosporidium in some wild, laboratory, and pet rodents in China and to assess the zoonotic potential of Cryptosporidium spp. from rodents. 相似文献
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During 1970-1972 haemobartonellosis occurred in research canines at 2 widely separated institutions. Clinical anemia occurred in a splenectomized dog at a Maryland facility, and subsequent screening disclosed an infection rate of 65% in a group of 20 splenectomized subjects. Treatment was successful, and the animals were used in research. A research institution in Texas encountered a number of dogs with fever (to 106 degrees F) and eosinophilia (to 42%) following minor surgery. Blood from affected animals was injected iv into splenectomized dogs, and 3 of 6 recipients developed haemobartonellosis. Further study was conducted, with some success, to establish a relationship between fever and eosinophilia and Haemobartonella canis infection in nonsplenectomized subjects. Our experiences suggest that haemobartonellosis is a widespread, latent disease of dogs and that significant potential exists for the infection to adversely affect research results. 相似文献
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Trypanosomes are protozoan parasites that cause major diseases in humans and other animals. Trypanosoma brucei and Trypanosoma cruzi are the etiologic agents of African and American Trypanosomiasis, respectively. In spite of large amounts of information regarding various aspects of their biology, including the essentially complete sequences of their genomes, studies directed towards an understanding of mechanisms related to DNA metabolism have been very limited. Recent reports, however, describing genes involved with DNA recombination and repair in T. brucei and T. cruzi, indicated the importance of these processes in the generation of genetic variability, which is crucial to the success of these parasites. Here, we review these data and discuss how the DNA repair and recombination machineries may contribute to strikingly different strategies evolved by the two Trypanosomes to create genetic variability that is needed for survival in their hosts. In T. brucei, two genetic components are critical to the success of antigenic variation, a strategy that allows the parasite to evade the host immune system by periodically changing the expression of a group of variant surface glycoproteins (VSGs). One component is a mechanism that provides for the exclusive expression of a single VSG at any one time, and the second is a large repository of antigenically distinct VSGs. Work from various groups showing the importance of recombination reactions in T. brucei, primarily to move a silent VSG into an active VSG expression site, is discussed. T. cruzi does not use the strategy of antigenic variation for host immune evasion but counts on the extreme heterogeneity of their population for parasite adaptation to different hosts. We discuss recent evidence indicating the existence of major differences in the levels of genomic heterogeneity among T. cruzi strains, and suggest that metabolic changes in the mismatch repair pathway could be an important source of antigenic diversity found within the T. cruzi population. 相似文献
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African trypanosomes are devastating human and animal pathogens that cause significant human mortality and limit economic development in sub-Saharan Africa. Studies of trypanosome biology generally consider these protozoan parasites as individual cells in suspension cultures or in animal models of infection. Here we report that the procyclic form of the African trypanosome Trypanosoma brucei engages in social behavior when cultivated on semisolid agarose surfaces. This behavior is characterized by trypanosomes assembling into multicellular communities that engage in polarized migrations across the agarose surface and cooperate to divert their movements in response to external signals. These cooperative movements are flagellum-mediated, since they do not occur in trypanin knockdown parasites that lack normal flagellum motility. We term this behavior social motility based on features shared with social motility and other types of surface-induced social behavior in bacteria. Social motility represents a novel and unexpected aspect of trypanosome biology and offers new paradigms for considering host-parasite interactions. 相似文献