Experimentally induced infection of gerbils with cilia-associated respiratory bacillus.
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Animals↗
Biomedical subjects
C L Franklin
Publications and source records attributed to C L Franklin.
Enteric lesions in SCID mice infected with "Helicobacter typhlonicus," a novel urease-negative Helicobacter species.
BACKGROUND AND PURPOSE: Several rodent helicobacters have been associated with chronic active hepatitis or inflammatory bowel disease. Severe combined immunodeficient (SCID) mice appear to be inherently susceptible to disease attributable to these emerging pathogens. With the advent of polymerase chain reaction (PCR) analysis, it has become clear that several as yet unidentified Helicobacter species may also colonize rodents, but their capacity to cause disease is unknown. METHODS: A Helicobacter species isolated from feces of a BALB/c mouse and provisionally named "H. typhlonicus" was used to inoculate helicobacter-free 4-week-old SCID mice (n = 11 males and 11 females). At various weeks after inoculation, mice were sacrificed and liver and intestinal specimens were collected for histologic examination and PCR analyses. RESULTS: The C.B-17 scid/scid mice inoculated with "H. typhlonicus" developed moderate to severe proliferative typhlocolitis, similar to that seen in SCID mice infected with H. hepaticus or H. bilis. However, in contrast to mice infected with H. hepaticus or H. bilis, lesions of chronic active hepatitis were not detected in mice inoculated with "H. typhlonicus." A similar disease syndrome developed in SCID mice cohabitated with B6D2F1 mice naturally infected with a novel Helicobacter species that was genetically identical to "H. typhlonicus." CONCLUSION: "Helicobacter typhlonicus" joins a growing list of helicobacters that are capable of inducing enteric disease in immunodeficient mice.
Animals↗
Interleukin-12 has a role in mediating resistance of murine strains to Tyzzer's disease.
Clostridium piliforme induces enterohepatic disease in many domestic and laboratory animal species. Susceptibility to infection is known to vary with the immune status and strain of the host, but little is known about specific immune mechanisms that regulate this disease. To evaluate host control of C. piliforme infection, we examined the role of interleukin-12 (IL-12) both in the control of and in the response to murine C. piliforme infection. For this study, 3-week-old C. piliforme-resistant C57BL/6 or -susceptible DBA/2 mice were infected intravenously with either the toxic H1 or the nontoxic M1 C. piliforme isolate. Serum and liver samples were collected prior to C. piliforme inoculation (day 0) and at days 1, 3, 7, 14, and 28 postinoculation. Evaluation of hepatic IL-12 p40 mRNA expression by reverse transcription-PCR and of total-IL-12 protein levels in serum by enzyme-linked immunosorbent assay revealed that C. piliforme induced elevations in both hepatic p40 mRNA and serum total-IL-12 levels at all times postinoculation. Elevations were similar with both toxic and nontoxic C. piliforme isolates. Levels of total IL-12 in serum were significantly (P < 0.05) higher in C57BL/6 mice than in DBA/2 mice. Additional experiments were performed in which polyclonal antibody treatment was used to neutralize IL-12 in mice of both strains prior to intravenous inoculation with toxic C. piliforme H1. IL-12 neutralization increased the severity of Tyzzer's disease at day 3 postinoculation in both mouse strains, but the degree of increase was greater in C57BL/6 mice than in DBA/2 mice.
Animals↗
Antigenic analyses of cilia-associated respiratory (CAR) bacillus isolates by use of monoclonal antibodies.
Mouse monoclonal antibodies (MAbs) developed to a rat isolate (R-3) of cilia-associated respiratory (CAR) bacillus were used to assess antigenic relationships among three rat and five rabbit CAR bacillus isolates. Evaluation of MAbs by enzyme-linked immunosorbent assays (ELISAs) indicated that 87 of 241 hybridomas secreted CAR bacillus-reactive antibodies that could be grouped into four major groups. Group-I MAbs reacted with epitopes expressed by all CAR bacillus isolates and at least two or more nonrelated species of bacteria. Group-II, -III, and -IV MAbs reacted with only one or more of the rat CAR bacillus isolates; no MAbs reacted only with rat and rabbit CAR bacillus isolates. Western blot analyses indicated that 41-, 50-, and 105-kDa peptides of rat CAR bacillus isolates expressed rat CAR bacillus group- and isolate-specific epitopes. Hyperimmune anti-CAR bacillus antiserum and serum specimens from a CAR bacillus histologically positive mouse and rat also reacted with the 41-, 50-, and 105-kDa peptides. Sera from CAR bacillus histologically negative rats did not react with these peptides. These results suggest that the 41-, 50-, and 105-kDa peptides may represent suitable antigens for development of a specific ELISA for detection of rodent CAR bacillus infections. Furthermore, these data indicate that use of crude CAR bacillus preparations for either rat or rabbit CAR bacillus ELISAs is inappropriate.
Animals↗
Transmission of Helicobacter hepaticus infection to sentinel mice by contaminated bedding.
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Animal Husbandry↗
Enterohepatic lesions in SCID mice infected with Helicobacter bilis.
Helicobacter bilis is a recently identified species that colonizes the intestine and liver of mice. In immunocompetent mice, infections have been associated with mild hepatitis, and in immunocompromised mice, inflammatory bowel disease has been induced by intraperitoneal inoculation of the organism. We report inoculation of 6-week-old C.B-17 scid/scid mice by gastric gavage with approximately 10(7) H. bilis colony-forming units. Groups of mice were euthanized and necropsied 12, 24, and 36 weeks after inoculation. Mild to moderate proliferative typhlitis was evident in all mice at 12 and 36 weeks after inoculation and in most mice 24 weeks after inoculation. Mild to severe chronic active hepatitis was detected in 10 of 10 male mice and 3 of 10 female mice. These results indicate that H. bilis can cause moderate to severe enterohepatic disease in immunocompromised mice.
Animals↗
Association of cilia-associated respiratory (CAR) bacillus with natural chronic tracheitis in goats.
A histological, histochemical and immunohistological study of the respiratory tract of 83 slaughtered goats (50 adults and 33 kids) is described. Cilia-associated respiratory (CAR) bacillus was detected by means of the Warthin Starry method in the tracheal epithelium of seven (21.2%) of the kids and 16 (32%) of the adult goats. A chronic diffuse tracheitis characterized by mixed lymphocyte and plasma-cell infiltration was found in all seven kids and in 17 adults, including the 16 infected with the CAR bacillus. Although not proved, it is possible that the CAR bacillus caused the chronic tracheitis. Immunohistochemical results suggested that the caprine CAR bacillus was closely related to the rabbit CAR bacillus.
Animals↗
Natural cilia-associated respiratory bacillus infection in rabbits used for elaboration of hyperimmune serum against Mycoplasma sp.
Cilia-associated respiratory (CAR) bacillus was identified in lung lesions of rabbits used for elaboration of hyperimmune serum against Mycoplasma mycoides ssp. capri (Mmc). Numerous Warthin Starry (WS) positive filamentous bacteria aligned perpendicularly to the surface of bronchial epithelial lining were observed. Immunoperoxidase staining of these bacteria was detected using a serum anti-rabbit CAR bacillus. Ultrastructural morphology corresponds to that of CAR bacilli previously reported in rabbits. The desirability of monitoring laboratory rabbits for CAR bacillus infection as part of the health programme is reinforced, especially in rabbits used for raising sera against respiratory pathogens of animal species in which CAR bacillus infection has been described. This is the first report of natural CAR bacillus infection in rabbits in Europe.
Animals↗
Effects of neutrophil, natural killer cell, and macrophage depletion on murine Clostridium piliforme infection.
Clostridium piliforme infection (Tyzzer's disease) induces enterohepatic disease in many domestic and laboratory animals. Murine susceptibility to Tyzzer's disease varies with host strain, age, and immune status However, little is known about the role of the immune system in control of this disease. To investigate the role of host immunity in Tyzzer's disease, mice were depleted of either neutrophils, natural killer cells, or macrophages by antibody administration or chemotherapy. After depletion, DBA/2 mice, which are naturally susceptible to C. piliforme, or naturally resistant C57BL/6 mice were inoculated intravenously with C. piliforme. Animals were euthanized 3 days postinoculation and evaluated for gross and histologic lesions and hepatic bacterial load. In juvenile DBA/2 or C57BL/6 mice, depletion of either neutrophils or natural killer cells increased severity of disease. In adult mice, depletion of natural killer cells significantly increased severity of Tyzzer's disease in the resistant (C57BL/6) but not in the susceptible (DBA/2) strain. Macrophage depletion did not alter the course of infection in either mouse strain. These studies indicate an important role for neutrophils and natural killer cells in the pathogenesis of murine Tyzzer's disease. The role of macrophages in murine C. piliforme infection will require further evaluation.
Animals↗
Serodiagnosis of Helicobacter hepaticus infection in mice by an enzyme-linked immunosorbent assay.
Helicobacter hepaticus is a newly recognized bacterium associated with chronic active hepatitis, hepatic carcinoma, and inflammatory bowel disease in mice. Currently, fecal or tissue PCR, fecal culture, or histologic examination of silver-stained liver sections is used to diagnose H. hepaticus infection. In this report, we describe an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of H. hepaticus infection in mice with a membrane digest preparation of H. hepaticus as the antigen. Sera from mice positive for H. hepaticus by PCR or histologic examination (n = 88), positive for Helicobacter bilis by PCR (n = 13), positive for other helicobacters (not identifiable to species level) by PCR (n = 25), or negative for all Helicobacter species by PCR (n = 162) were used to evaluate the ELISA. Results indicated that ELISA provided 93.2% sensitivity, 94% specificity, 87.2% positive predictive value, and 96.9% negative predictive value. Cross-reactive antibodies were detected in some mice infected with helicobacters not identifiable to species level. To further define ELISA sensitivity and specificity, groups of 10 C57BL/6 mice were inoculated per os with H. hepaticus, Helicobacter muridarum, or H. bilis. Sera were collected and examined by the ELISA. H. hepaticus-infected mice seroconverted by 2 weeks and maintained ELISA reactivity throughout the 18-week study, while mice infected with H. muridarum and H. bilis were negative by ELISA. These results indicate that this reported ELISA is highly sensitive and specific for the serodiagnosis of H. hepaticus infection in mice.
Animals↗
Fecal PCR assay for diagnosis of Helicobacter infection in laboratory rodents.
A fecal PCR assay for detection of Helicobacter infections in laboratory rodents was developed. DNA was isolated from murine fecal pellets, and a region of the 16S rRNA gene conserved among murine Helicobacter species was amplified. The fecal PCR was sensitive and specific. This assay does not require euthanasia of rodents, which is especially important for valuable rodents, such as transgenic mice.
Animals↗
Mouse strain and age affect susceptibility to experimentally induced genital trichomoniasis.
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Aging↗
Evaluation of hyperplastic goiter in a colony of Syrian hamsters (Mesocricetus auratus).
Hyperplastic goiter was diagnosed during routine health monitoring of a closed Syrian hamster colony (SG). Adult and juvenile hamsters were affected at a prevalence of 45%. Histologic examination of the enlarged thyroid gland revealed marked follicular cell hyperplasia. Because prevalence of thyroid hyperplasia in this colony exceeded the 6 to 7% prevalence expected in aged hamsters, additional studies were performed to investigate the pathogenesis of this condition. Juvenile male SG hamsters and age- and sex-matched Syrian hamsters that did not have increased prevalence of goiter were obtained from an unrelated source (Fredrick Cancer Research and Development Center [FCRDC]). The thyroid glands of hamsters were evaluated by 123I radionuclide imaging. Eight of 18 SG hamsters and none of the FCRDC hamsters had a diagnosis of enlarged thyroid gland. Serum baseline and post-thyrotropin thyroxine concentrations in SG hamsters were not statistically different from those in FCRDC hamsters. To investigate whether diet played a role in development of hyperplastic goiter, for 6 months 15 FCRDC hamsters were fed the diet that had been fed to SG hamsters (mouse breeder diet), and five were fed a control diet. To determine whether dietary change would result in resolution of goiter, affected SG hamsters were fed a control diet for 3 months. At the end of each feeding trial, thyroid gland uptake of 123I was reevaluated. The amount of 123I taken up by the thyroid glands of FCRDC hamsters fed the mouse breeder diet was not significantly different from that of controls. In contrast, thyroid gland uptake of 123I remained high for all affected SG hamsters fed the control diet. On the basis of results of these investigations, diet was ruled out as the cause of goiter. Also, a diagnosis of euthyroid hyperplastic goiter was made for the SG hamsters. A genetic cause is suspected to play a role in the increased prevalence of goiter in SG hamsters.
Animals↗
Molecular characterization of newly recognized rodent parvoviruses.
Several autonomous rodent parvoviruses distinct from the prototypic rodent parvoviruses have been isolated. These include variants of a mouse parvovirus (MPV), a hamster isolate designated hamster parvovirus (HaPV), and a variant strain of minute virus of mice (MVM) designated MVM-Cutter or MVM(c). In this study, the DNA sequence of the coding regions of the viral genome and the predicted protein sequences for each of these new isolates were determined and compared to the immunosuppressive and prototypic strains of MVM [MVM(i) and MVM(p)], the rodent parvovirus H-1, and LuIII, an autonomous parvovirus of uncertain host origin. Sequence comparisons showed that the MPV isolates were almost identical, HaPV was very similar to MPV, and MVM(c) was most similar to MVM(i) and MVM(p). Haemagglutination inhibition assays revealed that MPV and HaPV represent two serotypes distinct from previously characterized rodent parvovirus serotypes while MVM(c) belongs to the MVM serotype. Each of the newly isolated rodent parvoviruses was shown to encapsidate a predominantly negative-sense 5 kb DNA genome and to encode two nonstructural proteins (NS1 and NS2) and two structural viral proteins (VP1 and VP2). These studies indicate that MPV and HaPV are autonomous parvoviruses distinct from previously characterized parvoviruses and MVM(c) is a variant strain of MVM distinct from MVM(i) and MVM(p).
Amino Acid Sequence↗
Isolation of a novel Helicobacter species, Helicobacter cholecystus sp. nov., from the gallbladders of Syrian hamsters with cholangiofibrosis and centrilobular pancreatitis.
A filamentous, gram-negative, motile bacterium with a single polar sheathed flagellum was isolated from gallbladders of hamsters with cholangiofibrosis and centrilobular pancreatitis. Bacteria grew under microaerophilic conditions at 37 and 42 degrees C, were oxidase, catalase, arginine aminopeptidase, and L-arginine arylamidase positive, reduced nitrate to nitrite, were resistant to cephalothin, and exhibited intermediate susceptibility to nalidixic acid. Sequence analysis of the 16S rRNA gene indicated that the bacterium was a novel member of the Helicobacter genus, most closely related to Helicobacter pametensis. We propose to name this bacterium Helicobacter cholecystus. In epidemiologic studies, isolation of H. cholecystus correlated strongly with the presence of cholangiofibrosis and centrilobular pancreatitis; however, further studies are needed to define the role of this bacterium in pathogenesis.
Animals↗
Expression of recombinant parvovirus NS1 protein by a baculovirus and application to serologic testing of rodents.
A recombinant baculovirus containing the NS1 gene of minute virus of mice was constructed. Optimal expression of the recombinant NS1 protein (rNS1) was achieved by infecting Trichoplusa ni High Five cells at a multiplicity of 10 and incubating them for 72 h postinfection. An enzyme-linked immunosorbent assay (ELISA) with rNS1 as the antigen was evaluated for serologic testing of laboratory rodents. The rNS1 ELISA proved to be a more sensitive method for the detection of antibodies to recently recognized rodent parvovirus species (mouse orphan parvovirus and rat orphan parvovirus) and prototypic parvovirus species (minute virus of mice, Kilham's rat virus, and H-1) than were conventional parvovirus ELISAs that use whole parvovirus virions.
Amino Acid Sequence↗
Identification of murine helicobacters by PCR and restriction enzyme analyses.
Three murine helicobacter species have recently been identified: Helicobacter hepaticus, Helicobacter muridarum, and Helicobacter bilis. Infections with H. hepaticus and H. bilis have been associated with hepatitis and hepatic neoplasia. In this study, oligonucleotide primers were designed from regions of the 16S rRNA gene that are conserved among members of the Helicobacter genus. The assay amplified the expected 374-bp product from all three rodent Helicobacter species and was able to detect as little as 5 pg of H. hepaticus, H. bilis, or H. muridarum DNA. The specificity of the reaction was determined by testing cecal DNA from uninfected mice and mice with documented Helicobacter infections and by testing DNA from other bacterial genera. A product of the expected size was generated with cecal DNA from Helicobacter-infected mice but not with DNA from uninfected mice. With the exception of that of "Flexispira rappini, " which is closely related to the Helicobacter genus, DNA from other bacterial genera was not amplified with the Helicobacter genus-specific primers. MboI, MaeI, and HhaI restriction enzyme analyses of the amplified product were able to differentiate among the murine Helicobacter species but could not differentiate H. bilis from "F. rappini." To distinguish H. bilis, a reverse primer based on H. bilis 16S rRNA sequence was designed. PCR with the H. bilis-specific reverse primer (Hbr) and the Helicobacter genus-specific forward primer (H276f) amplified H. bilis DNA but not DNA from "F. rappini" or other rodent helicobacters. Examination of a large number of murine cecal tissues with this combination of PCR assays and restriction enzyme analyses indicated that H. hepaticus and H. bilis infections are widespread in laboratory mouse and rat colonies.
Animals↗
Lesions of experimental genital Tritrichomonas foetus infections in estrogenized BALB/c mice.
Ninety-seven BALB/c mice were inoculated intravaginally with 8.0 x 10(5) Tritrichomonas foetus organisms, using either isolate ATCC 30003 or field isolate MU Y22 2 days after estrogenization with 15 micrograms 17 beta-estradiol. Reproductive tracts were examined at several time points post-inoculation to determine gross and histologic responses to trichomonad infection as compared to estrogenized, uninfected control animals. The two isolates varied greatly in ability to maintain chronic infection; no ATCC 30003-inoculated animals remained culture-positive beyond 7 weeks post-inoculation, whereas MU Y22-inoculated animals were infected for greater than 26 weeks. Lesions were seen in 40-60% of animals prior to 10 weeks post-inoculation and included moderate uterine dilation and glandular atrophy, uterine gland abscesses, pyometra, intramural perivascular lymphoid infiltrates, and ovarian bursitis. The severity of lesions was independent of the T. foetus isolate. Lesions became more severe at 10 weeks post-inoculation, and at 10 and 26 weeks post-inoculation, lesions were seen in 60% and 75% of animals, respectively. In addition to lesions described above, epithelial changes were marked at these late necropsies, including ulceration, flattening, hypertrophy, and squamous metaplasia. The lesions seen in these mice closely resemble those described in natural bovine infection, suggesting that the estrogenized BALB/c mouse is an excellent model for study of bovine trichomoniasis.
Administration, Intravaginal↗