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Evidence from epidemiological and molecular studies of bovine Escherichia coli O157∶H7 suggests that strains are frequently transmitted across wide geographic distances. To test this hypothesis, we compared the geographic and genetic distance of a set of international bovine Escherichia coli O157∶H7 isolates using the Mantel correlation. For a measure of genetic relatedness, pulsed-field gel electrophoresis of six different restriction enzyme digests was used to generate an average Dice similarity coefficient for each isolate pair. Geographic distance was calculated using latitude and longitude data for isolate source locations. The Mantel correlation between genetic similarity and the logarithm of geographic distance in kilometers was −0·21 (P<0·001). The low magnitude of the Mantel correlation indicates that transmission over long distances is common. The occurrence of isolates from different continents on the same cluster of the dendrogram also supports the idea that Escherichia coli O157∶H7 strains can be transferred with considerable frequency over global distances.

A monomeric form of human interleukin 10 (IL-10M1) has been engineered for detailed structure-function studies on IL-10 and its receptor complexes. Wild type IL-10 (wtIL-10) is a domain swapped dimer whose structural integrity depends on the intertwining of two peptide chains. wtIL-10 was converted to a monomeric isomer by inserting 6 amino acids into the loop connecting the swapped secondary structural elements. Characterization of IL-10M1 by mass spectroscopy, size exclusion chromatography, cross-linking, and circular dichroism shows that IL-10M1 is a stable alpha-helical monomer at physiological pH whose three-dimensional structure closely resembles one domain of wtIL-10. As previously reported, incubation of wtIL-10 with a soluble form of the IL-10Ralpha (sIL-10Ralpha) generates a complex that consists of 2 wtIL-10 molecules and 4 sIL-10Ralphas. In contrast, IL-10M1 forms a 1:1 complex with the sIL-10Ralpha. Characterization of the interaction using isothermal titration calorimetry confirmed the 1:1 stoichiometry and yielded a dissociation constant of 30 nm with an apparent binding enthalpy of -12.2 kcal/mol. Despite forming a 1:1 complex, IL-10M1 is biologically active in cellular proliferation assays. These results indicate that the 1:1 interaction between IL-10M1 and IL-10Ralpha is sufficient for recruiting the signal transducing receptor chain (IL-10Rbeta) into the signaling complex and eliciting IL-10 cellular responses.

Pasteurella multocidaA:3 was isolated during an outbreak of pasteurellosis in Flemish Giant (FG) rabbits. Since New Zealand White (NZW) rabbits housed in the same room were not as severely affected as FG rabbits, experimental inoculation was undertaken to determine if FG rabbits were more susceptible than NZW rabbits to pasteurellosis induced by this isolate. Rabbits of each breed were inoculated with P. multocidaA:3 and observed for 3 weeks. Four of 5 FG rabbits developed severe clinical disease on days 6, 9, 12 and 14 after inoculation; whereas, the one affected NZW rabbit became ill 14 days after inoculation. All rabbits with clinical disease developed fibrinosuppurative pleuritis, pyothorax and pneumonia which was more severe in FG than NZW rabbits. At necropsy, P. multocidaA:3 was isolated from multiple sites of the diseased rabbits. No significant difference (P=0·099) in the prevalence of lesions between the two breeds was found; however, the score of pneumonia and pleuritis was 3 times greater in FG rabbits than NZW rabbits.

The role of rotavirus in diarrheal disease of rabbits was investigated, and a model for human rotavirus infection was established. Orogastric inoculation of 8- and 12-week-old New Zealand White rabbits with a rabbit strain of rotavirus (L:ALA:84) resulted in fecal shedding of virus for 6 to 8 days from 2 to 5 days after inoculation. Most rabbits exhibited diarrhea, coincident with the onset of viral shedding, which persisted for 2 to 4 days. Diarrhea was characterized by soft or fluid stools and fecal staining of the perineum. Inoculation of 3-week-old rabbits resulted in a briefer period of viral shedding and diarrhea of a milder nature. Histopathologic examination during the period of viral shedding revealed a mild, nonsuppurative enteritis. Inoculated rabbits exhibited antibodies in serum to rotavirus by enzyme-linked immunosorbent assay. Sham-inoculated or uninoculated rabbits maintained in the same cage or the same room with inoculated rabbits acquired rotavirus infection. The mild diarrheal disease which resulted with a rotavirus isolate from severe field cases suggests that cofactors were involved.

The most prevalent findings in reproductive tracts of 38 laboratory and 17 free-ranging Rhesus female monkeys were vaginitis, cervicitis, metritis, pelvic endometriosis and uterine adenomyosis. Several monkeys had cervical dysplasia and one had a serous cystadenoma. The findings in the two groups were similar although prevalence for several diseases differed. There was a significant relationship between the occurrence of vaginitis, metritis, adenomyosis and endometriosis and gravidity, time since last pregnancy, number of matings, hysterotomies, reproductive ability and reproductive status.

Serological findings in a commercial colony of Hartley guineapigs revealed that about 70% had antibodies to Chlamydia psittacias detected by the microimmunofluorescence method. Conjunctivitis was evident in 140% of 86 guineapigs examined. Chlamydial antigen was detected in conjunctival scrapings by a direct immuno-fluorescence test using Chlamydia-specific monoclonal antibody; however, C. psittaciwas not demonstrated by other methods.

Five Cebus albifronsmonkeys were infected intravaginally with Herpesvirus hoministype 2. The resulting infection clinically, virologically, and serologically resembled that seen in humans. After the acute infection had ceased, one monkey shed virus spontaneously on two occasions while two others shed following adrenalin administration. Herpesvirus was recovered from the second and third sacral dorsal root ganglia of two monkeys by cocultivation. Despite a variety of techniques, we could not recover virus from any other tissues. In addition, we recovered herpesvirus from co-cultivated trigeminal ganglia of an ocularly infected monkey.

To determine the role of animals as possible sources for human infection with Campylobacter jejuni/coli, 218 human cases of Campylobacter enteritis diagnosed among members of Group Health Cooperative of Puget Sound, King County, Washington, from April 1982 through September 1983 were compared with 526 controls, randomly selected from Group Health Cooperative members. All subjects were questioned regarding animal exposures one week prior to illness (cases) or interview (controls). There was no increase in risk for C. jejuni/coli enteritis associated with contact with various animals. However, exposure to diarrheic animals was associated with a fourfold increase in the risk of C. jejuni/coli enteritis (odds ratio = 4.3, 95% confidence interval (CI) 1.9-9.7). Adjustment for potential confounding factors by logistic regression analysis yielded an odds ratio of 3.3 (95% CI 1.2-7.5) associated with such exposure. An estimated 6.3% of cases of C. jejuni/coli enteritis was attributed to exposure to diarrheic animals.

To determine the risk of toxoplasma infection to individuals exposed to cats in a research institution, we compared the prevalence of toxoplasma antibodies with exposure to cats in university employees. Of 116 employees tested, 42 (36 percent) had toxoplasma antibodies as determined by the indirect fluorescent antibody test. Women and individuals aged 35 years or more had a greater prevalence of antibodies. The antibody prevalence by occupation was 72.1 percent for physicians and those with doctorates, 45.3 percent for animal and veterinary technicians, 33.3 percent for research technicians, 28.2 percent for administrative staff, 25.0 percent for graduate students and fellows, and 13.4 percent for veterinarians. There was no significant positive association between exposure to cats and the prevalence of toxoplasma antibodies. A follow-up of seronegative employees, 6 and 18 months later, revealed no seroconversions indicative of acute toxoplasma infection. We concluded that there was no significant risk of toxoplasma infection in university employees exposed to cats.

The extracellular region of the human interleukin-10 (hIL-10) receptor was expressed using a myeloma cell line and was purified to homogeneity by ligand-affinity chromatography. SDS-polyacrylamide gel electrophoresis analysis indicated that the soluble receptor is glycosylated and has an apparent molecular mass of 35,000-45,000. Under native conditions, soluble hIL-10 receptor was determined by gel filtration to be a monomeric protein. Soluble hIL-10 receptor was able to inhibit the binding of 125I-hIL-10 to the full-length receptor and was able to antagonize the effect of human IL-10 in cell proliferation and cytokine synthesis inhibition. The apparent dissociation constant (Kd) of soluble hIL-10 receptor was determined to be 563 +/- 59 pM, approximately 2- to 10-fold higher than that found on intact cells (Tan, J. C., Indelicato, S. R., Narula, S. K., Zavodny, P. J., and Chou, C.-C. (1993) J. Biol. Chem. 268, 21053-21059; Liu, Y., Wei, S. H.-Y., Ho, A. S.-Y., de Waal Malefyt, R., and Moore, K. W. (1994) J. Immunol. 152, 1821-1829). When hIL-10 binds soluble hIL-10 receptor in solution, a single complex was detected by gel filtration, and the complex was found to consist of two hIL-10 dimers and four soluble receptor monomers, suggesting that hIL-10 may induce a novel mode of oligomerization of the receptor upon binding.

Three antigen preparations of Pasteurella multocida, lipopolysaccharide antigen, boiled-cell extract antigen, and boiled whole-bacterium antigen, were used in an enzyme-linked immunosorbent assay (ELISA) to detect rabbit immunoglobulin G antibody to P. multocida. The sensitivity of each antigen preparation was compared by using sera from P. multocida-infected and uninfected rabbits and sera from two rabbits immunized with different serotypes of P. multocida. In the ELISA, all three antigen preparations detected high titers of antibodies in infected rabbits and markedly lower levels in uninfected rabbits. When whole-bacterium or boiled-cell extract antigens were used, the ELISA detected antibodies in sera from both immunized rabbits, but with lipopolysaccharide antigen, only antibody to the homologous serotype was detected. Sera absorbed with P. multocida and Bordetella bronchiseptica, another respiratory pathogen of rabbits, revealed that antibodies detected in the ELISA did not cross-react. Since the lipopolysaccharide antigen was more difficult to prepare and may be type specific, and since the whole-bacterium antigen was the least sensitive, the boiled-cell extract was chosen as the best antigen preparation to use in the ELISA.

Popliteal lymph nodes from eight New Zealand white rabbits with clinical or serological evidence of naturally acquired infection with Treponema paraluis-cuniculi were transferred to rabbits that had not been exposed to this infection. Lymph nodes from two rabbits successfully transmitted infection. The nodes from one of these rabbits transmitted infection during both the acute and chronic stages of infection. Recipients that were successfully infected showed concomitant antibody responses in the Venereal Disease Research Laboratory (VDRL), rapid plasma reagin (RPR), and fluorescent treponemal antibody-absorption (FTA-ABS) tests six to 10 weeks after inoculation; recipients of uninfected nodes showed no change in serological state. Antibody responses were followed by the development of dark field positive genital lesions 14 to 15 weeks after inoculation. [ABSTRACT FROM PUBLISHER]

Ten sporadic cases of venereal spirochaetosis, caused by Treponema paraluis-cuniculi, were seen in New Zealand white rabbits in two years. An equal number of males and females were affected. Females tended to have milder clinical signs than males. Lesions were usually found on the prepuce in males and the vulva in females, although the anus and skin of the perineum were also affected. Facial lesions were rare. Lesions healed in seven to 28 days in rabbits treated with penicillin. Eight rabbits had antibodies reactive in the Venereal Disease Research Laboratory (VDRL), rapid plasma reagin (RPR), and fluorescent treponemal antibody absorbed (FTA-ABS) tests when the disease was first diagnosed. In several rabbits followed longitudinally, RPR test results became negative two to four months after antimicrobial treatment, VDRL antibody titres diminished but usually persisted at low levels, while FTA-ABS antibodies declined slowly and were still evident 12 months after treatment. [ABSTRACT FROM PUBLISHER]

Inoculation of the urethra, conjunctiva, pharynx, and anal canal of six male crab-eating macaques (Macaca fascicularis) with urethral exudate from male patients with urethral gonorrhoea or with laboratory gonococcal strains was unsuccessful in establishing infection or producing increased polymorphonuclear leucocytes on Gram stain. Intraurethral inoculation with laboratory strains of Ureaplasma urealyticum resulted in transiently positive urethral cultures for U. urealyticum and was associated in some cases with increased numbers of polymorphonuclear leucocytes on Gram stain of urethral material. The findings suggest that the crab-eating macaque may be useful for studying the pathogenesis of urethral infection with U. urealyticum. [ABSTRACT FROM PUBLISHER]

Two adult male baboons (Papio cynocephalus) were infected by urethral catheter with a Type D strain of Chlamydia trachomatis isolated from a male patient with nongonococcal urethritis. Chlamydial organisms were shed from the urethra for about 90 days and serum antibody developed. Intraurethral re-inoculation of homologous and heterologous (Type I) strains of Chalmydia, 4 and 11 months later, resulted in relatively shorter periods of infection of less than 15 days. The antibody titres and type-specific patterns were not substantially influenced by re-infection. [ABSTRACT FROM PUBLISHER]