Comparative prevalence of four enterotoxin genes among Escherichia coli isolated from swine   总被引：15，自引：0，他引：15  

H W Moon  R A Schneider  S L Moseley 《American journal of veterinary research》1986,47(2):210-212

Presence of Escherichia coli enterotoxin genes LT (heat-labile enterotoxin), STaP (heat-stable enterotoxin a, porcine genotype), STaH (heat-stable enterotoxin a, human genotype), and STb (heat-stable enterotoxin b) among 874 swine isolates of E coli was determined, using DNA probes and the DNA colony hybridization technique. Of the 874 isolates evaluated, 45% hybridized with at least one of the enterotoxin gene probes and were designated as enterotoxigenic E coli (ETEC). Eighty-five percent of the ETEC were from pigs with enteric colibacillosis. The remaining 15% were from pigs with edema disease or various other diseases, and from healthy swine. Seventy-four percent of the ETEC hybridized with the STb probe, 52% with STaP, and 31% with LT; ETEC did not hybridize with the STaH probe. Most of the ETEC hybridized with more than one enterotoxin gene probe. Isolates that hybridized with the LT probe also hybridized with STb. The most prevalent gene combination was LT-STb. However, 35% of the ETEC from neonatal (less than or equal to 1 week old) swine with enteric colibacillosis were of the STaP-only genotype, and 33% of the ETEC from older swine with enteric colibacillosis were of the STb-only genotype.  相似文献   

Attaching and effacing bacteria in the intestines of calves and cats with diarrhea   总被引：10，自引：0，他引：10  

A Pospischil  J G Mainil  G Baljer  H W Moon 《Veterinary pathology》1987,24(4):330-334

Histopathologic and electron microscopic examination of intestines of three calves and two cats revealed attaching effacing bacteria characteristic of enteropathogenic Escherichia coli (EPEC) in ileum, cecum, and colon. The attaching effacing bacteria in one of the calves contained bacteriophages, and an E. coli isolate from that calf was shown to produce Shiga-like toxin. These findings contribute to emerging evidence that attaching effacing intestinal bacteria are globally distributed pathogens in a variety of host species and that bacteriophage-mediated production of Shiga-like toxin is related to the virulence of such bacteria.  相似文献   

Shiga-like toxin production and attaching effacing activity of Escherichia coli associated with calf diarrhea   总被引：11，自引：0，他引：11  

J G Mainil  C J Duchesnes  S C Whipp  L R Marques  A D O'Brien  T A Casey  H W Moon 《American journal of veterinary research》1987,48(5):743-748

Four hundred twenty-nine isolates of Escherichia coli from calves were tested for the production of HeLa cell cytotoxin(s). Isolates that produced enough cytotoxin to be detected in culture supernatants of iron-depleted broth were considered to produce increased amounts of cytotoxins. Isolates also were tested for homology with a DNA probe for a gene that encodes localized adherence of human enteropathogenic E coli. Four isolates produced increased amounts of cytotoxin that was neutralized by Shiga antitoxin (toxin designated as Shiga-like toxin-I [SLT-I]). A 5th isolate produced increased amounts of cytotoxin (SLT+) that was not neutralized by the Shiga antitoxin, but was neutralized by antitoxin against a variant of SLT (toxin designated as SLT-II). None of the isolates hybridized with the probe for the localized adherence gene. Three of the SLT+ isolates belonged to human enteropathogenic E coli serogroups O26 and O111. All 5 of the SLT+ isolates were from calves with diarrhea, but none of the 5 SLT+ isolates contained genes for classic heat-labile or heat-stable enterotoxins, for K99 fimbriae, or for invasiveness; neither did any of them adhere to HeLa cells in culture. Three of the 5 SLT+ isolates had attaching and effacing activities when inoculated into ligated intestinal loops of rabbits. One of the isolates with attaching and effacing activity in rabbits was originally isolated from a calf with lesions characteristic of those produced by attaching effacing E coli (AEEC). Calves inoculated with this SLT+ AEEC isolate developed focal colonic lesions characteristic of those produced by AEEC, but did not develop diarrhea.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Efficacy of imidocarb diproprionate and primaquine phosphate in the prevention of tick-borne disease in imported hereford heifers in South Korea     

R. E. Purnell  Moon Chang Rae  Suh Myung Deuk 《Tropical animal health and production》1981,13(1):123-127

Summary This paper describes the build-up of tick-borne blood parasites in a group of Hereford heifers imported from New Zealand to the island of Jeju Do, South Korea. All became infected withTheileria sergenti and half withBabesia bigemina. An attempt was made to contain the 2 parasites by treatment with either primaquine phosphate or imidocarb diproprionate. Both drugs had some prophylactic activity againstT. sergenti for at least 26 days and imidocarb diproprionate eliminatedB. bigemina. SinceT. sergenti infections built up subsequently in the animals it is suggested that repeated prophylaxis combined with regular acaricide treatment of imported cattle is necessary to keep piroplasmosis under control.

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Eficacia Del Dipropionata De Imidocarb Y Del Fostato De Primaquine En La Prevencion De Enfermedades Producidas Por Hematozoarios En Terneras Hereford Importadas, En Corea Del Sur

Resumen El trabajo describe la infectación progresiva con hematozoarios de un grupo de terneras Hereford importadas por Corea del Sur de Nueva Zelandia. Todas se infectaron conTheileria sergenti y la mitad conBabesia bigemina. Los animales se trataron con fosfato de primaquine o con dipropionato de imidocarb. Ambas drogas tuvieron actividad profiláctica contraT. sergenti durante 26 días y el imidocarb eliminóB. bigemina. Debido a que los animales se reinfectaron nuevamente conT. sergenti, se sugiere un régimen profiláctico continuado, combinándolo con baños garrapaticidas en ganado importado para controlar la piroplasmosis.

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Efficacite Du Diproprionate D'imidocarbamide Et Du Phosphate De Primaquine Dans La Prevention De Maladies Transmises Par Les Tiques A Des Genisses Hereford Importees En Coree Du Sud

Résumé Cet article décrit le développement d'affections parasitaires sanguines transmises par les tiques dans un groupe de génisses importées de Nouvelle-Zélande en Corée du Sud. Tous les animaux ont été infectés parTheileria sergenti et la moitié parBabesia bigemina. Un essai a été fait pour contrôler ces deux parasites par des traitements avec du phosphate de primaquine ou du diproprionate d'imidocarbamide. Les deux produits ont eu une certaine activité pendant au moins 26 jours contreT. sergenti et l'imidocarbamide a éliminéBabesia bigemina. Les infections àTheileria sergenti ayant continué, il est suggéré qu'un régime répété de prophylaxie combiné avec un traitement acaricide des animaux importés est nécessire pour lutter efficacement contre les piroplasmoses.

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Seconded by the ODA to the Animal Health Laboratory, Jeju City, Republic of Korea.  相似文献   

Effects of Escherichia coli heat-stable enterotoxin b on small intestinal villi in pigs, rabbits, and lambs   总被引：4，自引：0，他引：4  

R Rose  S C Whipp  H W Moon 《Veterinary pathology》1987,24(1):71-79

Culture supernates from two strains of E. coli were placed into different ligated intestinal sections (loops) of each animal. The two bacterial strains were identical except that one contained a plasmid carrying the heat-stable toxin b (STb) gene, while the other did not. Morphometric techniques were used to assess villous epithelial surface areas and mucosal volumes in both intestinal segments exposed to STb-positive (test) and to STb-negative (control) supernates. In pigs whose intestines were exposed to STb-positive supernatants for 2 hours, both villous epithelial surface area and mucosal volume were significantly smaller in test loops than in control loops (P less than 0.02). In test loops of pigs incubated for 1 hour, and in test loops of lambs incubated for 2 hours, there was a decrease in villous epithelial surface area which approached the test for significance but did not meet it (0.05 less than P less than 0.10). Rabbit test loops did not differ from rabbit control loops in either villous epithelial surface area or mucosal volume. Histological examination of the tissues from all three species revealed epithelial changes in porcine and ovine tissues only. In porcine and ovine tissues, epithelium at villous tips was seen to be cuboidal or squamous, or even to be absent. Villi with similarly altered epithelium were seen in control loops, but were seen much more frequently in test loops. These epithelial changes were seen as early as 30 minutes of incubation in pigs. Intestinal tissues from these pigs were examined by transmission electron microscopy, but no difference between test and control tissues was seen.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Microscopic alterations in jejunal epithelium of 3-week-old pigs induced by pig-specific, mouse-negative, heat-stable Escherichia coli enterotoxin   总被引：3，自引：0，他引：3  

S C Whipp  S L Moseley  H W Moon 《American journal of veterinary research》1986,47(3):615-618

The objective of this study was to determine whether exposure of swine jejunum to crude culture filtrates containing Escherichia coli pig-specific, mouse-negative, heat-stable enterotoxin (STb) induces structural alterations in the jejunal mucosa of pigs. Two ligated intestinal loops in each of twelve 3-week-old pigs were exposed for 2 hours to sterile E coli culture filtrates from each of the following strains: 431 (STa-producing), 1261 (STa and STb-producing), and 1790 (STb-producing); recombinant strain HB101-pRAS-1 (STb-producing); the nontoxigenic K-12 variant HB101; or trypticase soy broth. Formalin-fixed sections from these loops were examined for sloughed cells around villi, and a lesion score was determined, indicating a change in villous epithelium from columnar to cuboidal or squamous cell types or to discontinuous epithelium. Villous lengths and crypt depths also were determined. For loops exposed to culture filtrates containing STa and STb or containing only STb, lesion scores and numbers of sloughed cells were greater (P less than 0.05) and villous length was shorter (P less than 0.01) than in loops not exposed to toxin. For loops exposed to culture filtrates containing STa, lesion scores, villus lengths, and numbers of sloughed cells were not different from those of loops not exposed to toxin. Therefore, exposure of swine jejunum to STb induced structural alterations in intestinal mucosa (ie, loss of villous absorptive cells and partial atrophy of villi) that were consistent with those causing compromised absorptive capacity.  相似文献   

Experimental Mycobacterium paratuberculosis infection in chickens   总被引：3，自引：0，他引：3  

A B Larsen  H W Moon 《American journal of veterinary research》1972,33(6):1231-1235

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Outbreaks of classical swine fever in the Republic of Korea in 2003     

Wee SH  Park CK  Jeong JM  Kim CH  Hwang IJ  Kim SJ  Yoon H  Lee ES  Nam HM  Park JY  Moon OK 《The Veterinary record》2005,157(4):113-115

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Association of Escherichia coli with diarrheal disease of the newborn pig   总被引：7，自引：0，他引：7  

H W Moon  D K Sorensen  J H Sautter  J M Higbee 《American journal of veterinary research》1966,27(119):1007-1011

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In vitro detection of Shiga toxin using porcine alveolar macrophages.     

W L Mengeling  A C Vorwald  N A Cornick  K M Lager  H W Moon 《Journal of veterinary diagnostic investigation》2001,13(5):421-424

Porcine alveolar macrophages were found to be highly susceptible to the cytolytic effects of a toxin (Shiga toxin [Stx]) produced by certain strains of Escherichia coli and sometimes associated with clinical disease in pigs and other animals. In comparison with the cells that are most commonly used for Stx detection and titration in vitro (namely, Vero cells), porcine alveolar macrophages appeared to be generally more sensitive and test results could be obtained in less time. Moreover, unlike Vero cells, porcine alveolar macrophages need not be continuously propagated to ensure immediate availability. They can simply be removed from a low-temperature repository, thawed, seeded, and shortly thereafter exposed to the sample in question. These characteristics suggest that porcine alveolar macrophages may be useful in developing a highly sensitive and timely diagnostic test for Stx.  相似文献