Clostridium difficile infection in adult hamsters.

Diarrhea was encountered in a group of adult female golden Syrian hamsters (Mesocricetus auratus) used for titrating the scrapie agent. Ninety percent of the cases occurred in animals over 210 days old even though animals of all age groups lived in the colony concurrently. The cause of diarrhea was investigated in both uninoculated animals and those receiving greater than a limiting dilution of scrapie infectivity, i.e., animals that were not expected to contract the experimental scrapie disease. Three forms of diarrhea were observed. The most commonly encountered was profuse and watery. A chronic form presented with semiformed, thin fecal material smearing the retroperitoneal region. Hemorrhagic diarrhea was observed rarely. Mortality was high among animals with acute watery or hemorrhagic diarrhea. Animals with semiformed soft stools were dehydrated, had a roughened hair-coat, and hunched back. Cardinal lesions were necrosis, inflammation, and mucosal hyperplasia of the cecum and colon and cholangiohepatitis with amyloid deposition. Diffuse renal amyloidosis was present in chronic cases. Toxigenic, cytotoxin B-positive Clostridium difficile was isolated from a majority of affected animals. Cytotoxin B was also present in cecal homogenates of diarrheic animals with C. difficile. The pathological and microbiologic findings indicated a typhlitis and colitis in adult hamsters that was associated with C. difficile infection.     

An outbreak of "wet tail" in hamsters due to Tyzzer's organism (author's transl)

In a colony of Golden hamsters, many animals were found to show signs of "wet tail", and spontaneous deaths occurred during two months. With this outbreak of wet tail and death, etiologic and pathologic studies were made on 11 cases supplied from the colony. Gross pathologic examination disclosed hemorrhagic enteritis in 10 and necrotic foci in the liver in 5 out of 10 cases examined. A number of bacilli morphologically suggestive of Tyzzer's organisms were detected on smears of cut surfaces of the affected intestines and livers. After inoculation with homogenate of the intestines from the moribund cases into hamsters by oral route, the same clinical manifestations as observed in spontaneous cases were reproduced, and the inoculated animals died in 10 to 14 days with numerous Tyzzer's organisms in their intestines and livers. When apparently healthy hamsters were introduced into contaminated cages with soiled bedding which were allowed to stand at room temperature for about 2 months, most of them developed signs of wet tail and died in 5 to 19 days having liver necrosis characteristic of Tyzzer's disease.     

Isolation of Corynebacterium kutscheri from aged Syrian hamsters (Mesocricetus auratus).

Corynebacterium kutscheri was isolated from the oral cavities of 12 male Syrian hamsters (Mesocricetus auratus) which were about 12 months old. At 1, 5, and 9 months after initial isolation of C. kutscheri from the oral cavity, hamsters were euthanatized, and attempts were made to culture C. kutscheri from 13 additional sites. Corynebacterium kutscheri was isolated from nine hamsters, and regardless of the hamsters' ages, the organisms were most frequently isolated from the oral cavity (100%), esophagus (100%), cecal content (100%), and colon and rectum (88.9%). Isolation rates in the nasal cavity were 66.7%, followed by 55.5% in the trachea and 33.3% in the submaxillary lymph nodes. The number of the organisms found in the submaxillary lymph nodes and esophagus was 10(3) to 10(4) CFU/g. The number found in the cecal content and in the colon and rectum was 10(2) to 10(5) CFU/g. The organisms were not isolated from lung, stomach, kidney, spleen, and mesenteric lymph node tissues. The hamsters had neither clinical signs nor lesions. However, 7 of 12 animals had low agglutinating antibody titers. The Syrian hamster can therefore be an asymptomatic carrier of C. kutscheri.     

Helicobacter bilis/Helicobacter rodentium co-infection associated with diarrhea in a colony of scid mice

An outbreak of diarrhea spanning 3 months occurred in a breeding colony of scid/Trp53 knockout mice. Approximately a third of the 150 mice were clinically affected, with signs ranging from mucoid or watery diarrhea to severe hemorrhagic diarrhea with mortality. Helicobacter bilis and the newly recognized urease-negative organism H. rodentium were isolated from microaerobic culture of feces or cecal specimens from affected mice. Dual infection with H. bilis and H. rodentium were confirmed by culture and polymerase chain reaction (PCR) in several animals. Both Helicobacter species rapidly colonized immunocompetent sentinel mice exposed to bedding from cages containing affected mice, but the sentinel remained asymptomatic. Mice with diarrhea had multifocal to segmental proliferative typhlitis, colitis, and proctitis. Several affected mice had multifocal mucosal necrosis with a few focal ulcers in the cecum, colon, and rectum. Mice with diarrhea were treated with antibiotic food wafers (1.5 mg of amoxicillin, 0.69 mg of metronidazole, and 0.185 mg of bismuth/mouse per day) previously shown to eradicate H. hepaticus in immunocompetent mice. Antibiotic treatment resulted in resolution of diarrhea, but not eradication of H. bilis and H. rodentium; mice continued to have positive PCR results after a 2-week treatment regimen, and clinical signs of diarrhea returned in some mice when treatment was suspended. To the authors' knowledge, this is the first report of natural infection with either H. bilis and/or H. rodentium causing acute diarrheal disease and suggests that H. bilis and/or H. rodentium can be an important pathogen for scid mice.     

Clostridium difficile-associated typhlitis in specific pathogen free guineapigs in the absence of antimicrobial treatment

Clostridium difficile (toxin) associated typhlitis was diagnosed in untreated barrier-maintained specific pathogen free guineapigs. It resembled the pathological lesions of antibiotic induced enterocolitis. The possible role of limited colonization resistance to C. difficile provided by mouse enteric microflora in the pathogenesis of the disease is discussed.     

Canine distemper in black-footed ferrets (Mustela nigripes) from Wyoming

In September and October 1985, six black-footed ferrets (Mustela nigripes) were captured from the only known population, located near Meeteetse, Wyoming for captive propagation. Two days following capture an adult male showed signs of canine distemper and an adult female displayed similar signs 7 days postcapture; these infections were undoubtedly acquired prior to capture. Subsequently the four remaining captive black-footed ferrets also developed canine distemper and all eventually died. Clinical signs included severe pruritus, hyperkeratosis and progressive loss of body condition. A few animals had intermittent diarrhea and respiratory disease. Intranuclear and intracytoplasmic inclusion bodies were numerous in epithelial tissues and two black-footed ferrets had a mild to moderate meningoencephalitis. Canine distemper virus was isolated from four animals and paramyxovirus nucleocapsids were observed by electron microscopy of feces from all affected black-footed ferrets. Antibodies to canine distemper virus were not detected in sera of sick black-footed ferrets. Antibodies to canine distemper virus were found in sera of badgers (Taxidea taxus) and coyotes (Canis latrans) collected in the Meeteetse area in 1986. Most free-ranging black-footed ferrets in the colony apparently died of canine distemper during the summer and fall of 1985. An attempt was made to capture all surviving animals in the affected area in order to abort the epizootic and provide black-footed ferrets for captive propagation.     

抗生素在体内外对厌氧菌和艰难梭菌细胞毒素生成的作用

氯林霉素、灭滴灵和甲砜霉素对大多数肠道厌氧菌的生长具抑制作用。氯林霉素还会破坏肠道菌群平衡,使原来受抑制的艰难梭菌得以定植,并在艰难梭菌浓度达10~8/g盲肠内含物时,检测到艰难梭菌细胞毒素。培养基中亚抑菌浓度的氯林霉素和灭滴灵会推迟艰难梭菌细胞霉素的生成。灭滴灵还可保护无菌小鼠及受氯林霉素处理的悉生小鼠免遭艰难梭菌细胞毒素的致死作用,从而证实了灭滴灵在伪膜性结肠炎临床治疗中的可用性。     

Eremomycin in the treatment of antibiotic-associated colitis in golden hamsters]

The efficacy of eremomycin, a new glycopeptide antibiotic, was studied on a model of antibiotic-associated colitis in golden hamsters. The colitis was induced by intraperitoneal or intragastric administration of lincomycin. In a dose of 100 mg/kg administered orally once a day for 5 days eremomycin protected the animals from the lincomycin-induced colitis: some animals survived, the others died in later periods. When the animals were infected with a pathogenetic strain of Clostridium difficile followed by exposure to lincomycin the use of eremomycin produced the similar effect.     

Microbiology and ration digestibility in the hindgut of the ovine

Contents of the terminal ilea, ceca-proximal colons, and terminal recta were obtained from nine sheep, three of which were fed 100% orchardgrass hay, three of which were fed 60% cracked corn-40% orchardgrass hay, and three of which were fed 80% cracked corn-20% orchardgrass hay. The digestibility of dry matter in the ceca was greatest when the all-hay diet was fed, whereas the percentage of cellulose digestion in the ceca increased with increasing levels of concentrate. For all diets, the total volatile fatty acid concentrations were higher in the ceca than in the other two sites. The cecal pH levels decreased with increased corn levels in the diet. The total microbiol numbers per gram of ileal and cecal contents increased in response to feeding of concentrate; however, across all diets, the ileal counts were 8% or less of the cecal counts. In contrast, the cellulolytic microbial numbers in the ilea were 50% or more of those in the ceca and were highest with the all-hay diet. Both bacterial and end product concentrations in the ceca were equivalent to those occurring in rumina. A total of 16 cellulolytic cultures were isolated and characterized from ileal and cecal contents of animals fed all three diets. Seven gram-negative-rod-shaped organisms were identified as Butyrivibrio fibrisolvens, whose capacity to digest cellulose exceeded that of several rumen strains. The guanine-plus-cytosine content of the DNA of one strain of B. fibrisolvens was 38.8 mol%, compared with the only previously reported value for this species of 41.2 mol%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Microbiology and ration digestibility in the hindgut of the ovine.

Contents of the terminal ilea, ceca-proximal colons, and terminal recta were obtained from nine sheep, three of which were fed 100% orchardgrass hay, three of which were fed 60% cracked corn-40% orchardgrass hay, and three of which were fed 80% cracked corn-20% orchardgrass hay. The digestibility of dry matter in the ceca was greatest when the all-hay diet was fed, whereas the percentage of cellulose digestion in the ceca increased with increasing levels of concentrate. For all diets, the total volatile fatty acid concentrations were higher in the ceca than in the other two sites. The cecal pH levels decreased with increased corn levels in the diet. The total microbiol numbers per gram of ileal and cecal contents increased in response to feeding of concentrate; however, across all diets, the ileal counts were 8% or less of the cecal counts. In contrast, the cellulolytic microbial numbers in the ilea were 50% or more of those in the ceca and were highest with the all-hay diet. Both bacterial and end product concentrations in the ceca were equivalent to those occurring in rumina. A total of 16 cellulolytic cultures were isolated and characterized from ileal and cecal contents of animals fed all three diets. Seven gram-negative-rod-shaped organisms were identified as Butyrivibrio fibrisolvens, whose capacity to digest cellulose exceeded that of several rumen strains. The guanine-plus-cytosine content of the DNA of one strain of B. fibrisolvens was 38.8 mol%, compared with the only previously reported value for this species of 41.2 mol%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Toxoplasma gondii infections in captive black-footed ferrets (Mustela nigripes), 1992-1998: clinical signs, serology, pathology, and prevention

An epizootic of toxoplasmosis occurred among 22 adult and 30 kit black-footed ferrets (Mustela nigripes) maintained under quarantine conditions at the Louisville Zoological Garden (Louisville, Kentucky, USA) in June, 1992. Black-footed ferrets appear to be highly susceptible to acute and chronic toxoplasmosis. Clinical signs were observed in 19 adults and six kits and included anorexia, lethargy, corneal edema, and ataxia. Two adults and six kits died with acute disease. High antibody titers to Toxoplasma gondii were detected by latex agglutination and modified agglutination assay in 10 black-footed ferrets. One adult and six kits that died with acute clinical signs were necropsied and T. gondii-like organisms were found microscopically in multiple organs. Diagnosis of toxoplasmosis was confirmed by immunohistochemical staining with anti-T. gondii antibodies and by ultrastructural examination. Although the source of T. gondii for black-footed ferrets was not identified, frozen uncooked rabbit was the most likely source. Chronic toxoplasmosis resulted in the death of at additional 13 black-footed ferrets that were adults during the epizootic. Affected animals developed chronic progressive posterior weakness and posterior ataxia 6-69 mo after the epizootic began. Meningoencephalitis or meningoencephalomyelitis associated with chronic toxoplasmosis were identified at necropsy in all 13 ferrets. Precautions to prevent introduction of pathogens into the colony were insufficient to exclude T. gondii. Although toxoplasmosis may cause significant mortality in mustelids, the high mortality of black-footed ferrets in this epizootic was of concern due to their endangered status. This is the first detailed report of toxoplasmosis in black-footed ferrets.     

Cecal volvulus in two African green monkeys (Cercopithecus athiops sabeus)

Following short-term signs of weakness, depression, and/or anorexia of less than 24 h, two adult male African green monkeys (Cercopithecus aethiops sabeus) of St. Kitts origin died from complications of cecal volvulus. Gaseous distention was radiologically apparent in one animal. Necropsy of both monkeys revealed cecal volvulus, one at the ileocecal junction and one involving a segment of the distal portion of the ileum and cecum. Congestion and hemorrhage were evident microscopically in the lamina propria of the affected intestine, with variable necrosis.     

A fatal enteric syndrome in Mystromys albicaudatus (white tailed rat) following topical antibiotic treatment.

Heavy death losses (59%) occurred in adult Mystromys 3--14 days after muscle biopsies were taken from their rear legs. Clinical signs included anorexia, depression, and rough hair coat. Predominant necropsy findings were hrmorrhagic typhlitis and colitis. Results of studies evaluating the roles of the anesthetic and the tropical antibiotic ointment suggested that the deaths were caused by ingestion of the topically applied antibiotic.     

Clostridium difficile: an important pathogen of food animals

Human Clostridium difficile-associated disease (CDAD) is of unquestioned importance in humans, and has been a not-uncommon cause of enteric disease in horses, dogs, and ratites. Over the past 5 years, C. difficile has emerged as a major cause of neonatal enteritis in pigs. Piglets 1-7 days of age are affected, with gross lesions frequently including mesocolonic edema. Colonic contents may be pasty-to-watery and yellow, although some piglets are constipated or obstipated. Focal suppuration and segmental necrosis are seen on microscopic examination of cecal and colonic lamina propria, and exudation of neutrophils and fibrin into the lumen gives rise to the so-called volcano lesions. Results of one study revealed that more than one-third of piglets with enteritis were affected by C. difficile alone, while an additional quarter of affected piglets may have had mixed infections. C. difficile may be the most important uncontrolled cause of neonatal diarrhea in pigs.     

Clostridium difficile-associated ileocecitis in clindamycin-treated infant hamsters

Infant hamsters, four days of age or older, developed aClostridium difficile-associated ileocecitis following clindamycin administration, whereas non-antibiotic-treated infant hamsters and hamsters less than four days old given clindamycin were asymptomatically colonized withC. difficile. The incidence of lethality among clindamycin-treated infant hamsters increased with age of the animals, such that all adult hamsters given clindamycin died within 72 h of treatment. Adult hamsters given clindamycin had significantly higher titers of cytotoxin throughout the intestinal tract compared with infant hamsters given clindamycin.     

In vivo lysogenization of a Clostridium difficile bacteriophage ФCD119

Clostridium difficile is a nosocomial pathogen identified as the cause of antibiotic-associated diarrhea and colitis. In this study, we have documented the lysogeny of a C.?difficile bacteriophage in hamsters during C.?difficile infection. The lysogens isolated from the hamsters were toxin typed and their phage integration site was confirmed by PCR. Through toxin ELISA it was found that the toxin production in the in?vivo isolated lysogens was affected due to ФCD119 lysogenization as in the case of in?vitro isolated ФCD119 lysogens. Together our findings indicate that a baceriophage can lysogenize its C.?difficile host even during the infection process and highlights the importance of lysogeny of C.?difficile phages as an evolutionary adaptation for survival.     

Effects of Promastigote Growth Phase,Frequency of Subculture,and Host Age on Promastigote-initiated Infections with Leishmania donovani in the Golden Hamster*†

Promastigotes of Leishmania donovani, 3S strain, were cultured from homogenized infected hamster spleen incubated at 25 C in a particle-free modification of Tanabe's (1923) medium, and were subcultured in this medium from 1 to 4 times. Promastigotes were inoculated intracardially to golden hamsters (Mesocricetus auratus). Promastigotes that were subcultured frequently by transfer from log phase of growth retained their infectivity for hamsters, as assayed by numbers of amastigotes in the liver at 16 days post infection. Promastigotes that were subcultured infrequently by transfer from stationary phase declined in infectivity. The extent of the decline was roughly proportional to the length of the incubation periods of the primary culture plus 1st subculture. Promastigotes harvested from log phase of growth were significantly less infective for hamsters than those harvested from stationary phase of growth, in that numbers of amastigotes found in the liver after 16 days were lower, and times to death longer, when log phase organisms were used to infect hamsters. The age of the hamster at the time of inoculation was found to affect the apparent infectivity of promastigotes from a 1st or 2nd subculture. When weanling (age 4 weeks), juvenile (age 8 weeks) and adult (age 24 to 32 weeks) hamsters received the same numbers of promastigotes, the weanlings had the highest numbers of liver amastigotes at 16 days, and shortest times to death, of the 3 groups; juveniles were intermediate between weanlings and adults; and adults had the lowest numbers of parasites and longest times to death of the host. Differences were statistically significant only between weanlings and adults. Responses of weanling and adult hamsters to infection with promastigotes could be rendered indistinguishable if the promastigotes were inoculated on the basis of 10⁵ promastigotes per g of host body weight.     

Tritrichomonas muris in the Hamster: Pseudocysts and the Infection of Newborn

SYNOPSIS. Female golden hamsters, either in the last week of pregnancy or in the first weeks of nursing, excreted in their feces variable numbers of pseudocysts of Tritrichomonas muris . Pseudocysts examined by electron microscopy had internalization of the 3 anterior flagella and the undulating membrane with its recurrent flagellum. The undulating membrane and the associated marginal lamellae were characteristic of T. muris . Pseudocysts gradually become motile after 2 or more hours of incubation in medium. The "excysted" trophozoites were identified ultrastructurally as T. muris . Newborn hamsters were not infected with T. muris at 3 days of age, but by the 7th day essentially all were found to have infected ceca, concomitant with cecal enlargement and the appearance of adult-type feces.     

Cellulolytic and non-cellulolytic bacteria in rat gastrointestinal tracts.

Lactobacillus and Bifidobacterium species were the predominant organisms isolated from small intestinal (jejunal) contents of rats, and lactic acid was the only organic acid detected. The numbers of cellulolytic bacteria in small intestines were low (approximately 10(3)/g). The fermentation in ceca was different from that in intestines, as, in addition to small amounts of lactic acid, high concentrations of volatile fatty acids were detected. The mixed cecal microflora was able to digest cellulose (pebble-milled Whatman no. 1) and cabbage. High numbers of cellulolytic bacteria were found (0.5 X 10(8) to 12.2 X 10(8)/g; 6% of total viable bacteria). The predominant celluloytic organism isolated was Bacteroides succinogenes. Ruminococcus flavifaciens was isolated from a few animals. The kinds and numbers of the predominant non-cellulolytic organisms isolated from rat ceca were similar to those described by previous workers.