To understand the mechanism of transovarian transmission of Salmonella enteritidis in laying hens, experiments were conducted to examine the isolation of S. enteritidis from the preovulatory follicles of experimentally infected hens. Salmonella enteritidis was isolated from the preovulatory follicles in 16 birds (from follicle membrane alone in 10 birds, from the follicle yolk alone in 4 birds, and from both membrane and yolk in 2 birds). In addition, 83 S. enteritidis isolates of the major phage types prevalent in United States were tested for attachment to hen ovarian granulosa cells and HEp-2 cells. Salmonella enteritidis demonstrated three different patterns of attachment to granulosa cells, namely, local, diffuse, and aggregative; whereas, only local attachment pattern was observed on HEp-2 cells. The total number of S. enteritidis isolates that demonstrated any pattern of attachment was significantly greater on the granulosa cells than on HEp-2 cells (P < .05). Salmonella enteritidis isolates of phage Types 8 and 28 demonstrated similar patterns of attachment on granulosa cells derived from the mature and developing follicles of the hen ovary. This suggest that S. enteritidis can colonize the preovulatory follicles at different stages of development. Preincubation of bacteria with the tetrapeptide arg-gly-asp-ser, the amino acid sequence known to mediate the interaction of adhesive proteins with cells, abrogated the local attachment of bacteria to granulosa cells. These results suggest that S. enteritidis can colonize the preovulatory follicles by interacting with the ovarian granulosa cells and that adhesive proteins may be involved in this process.

Aims:The aim of this study was to assess probiotic attributes such as adhesion, auto aggregation, hydrophobicity and antibacterial activity of Lactobacillus strains from dairy products. Methodology: In this study, the autoaggregation, coaggregation, hydrophobicity and adhering abilities and antimicrobial activities of six Lactobacillus strains belonging to different species were assessed. Hydrophobicity was determined by bacterial adherence to hydrocarbons, xylene, n-hexadecane and chloroform. Results: The percentage of hydrophobicity of the strains range from 29.5% to 77.4% as measured by the described test. The autoaggregation among Lactobacillus strains range from 15.8% to 63.1%, while coaggregation range from 18.6% to 55.1%. Adhesion of the tested strains to buccal epithelial cells range from 8.0% to 50%. The tested Lactobacillus strains demonstrated variable inhibitory activity against pathogenic bacteria. Conclusion: Our findings indicated that one Lactobacillus strain expressed broad antibacterial activities against a group of bacterial pathogens and along 2 other strains exhibited ability to adhere to epithelial cells as shown by aggregation, coaggregation and hydrophobicity, indicating that such isolates can be good candidates for probiotic use.

SUMMARYWe have evaluated solid-phase ELISA IgG antibody avidity studies as a means of identifying cases of recent HIV-1 infection. Although separate studies on the avidity of anti-gp41 and anti-p24 antibodies in seroconvertors have been reported, a comparison of the ability of patients to simultaneously mature their immune response to more than one HIV antigen immediately following seroconversion appears to be lacking. We have demonstrated a maturation in anti-gp41 avidity which reflects the time since seroconversion in all cases. In contrast, however, only some patients produced high-avidity anti-p24 or anti-p17 antibodies during the same time span. While the avidity of anti-gp41 antibodies remained high in cases of non-recent HIV infection, even in the face of advanced disease, we have confirmed the findings of others that the avidity of anti-p24 falls before the onset of ARC or AIDS. Therefore, whilst the avidity of anti-gp41 antibodies could reliably be of value in identifying cases of recent HIV infection, the avidity of anti-p24 or anti-p17 antibodies could not, but may be of prognostic value, even at an early stage. The time taken to reach maximum anti-p17, anti-p24 and anti-gp41 titres was variable, but anti-gp41 titres, like anti-gp41 avidity, remained high. In contrast, anti-p24 titres fell, even during the early follow-up period in some seroconvertors. Anti-p24 antibody avidity, however, appeared to be a better predictor of disease progression in 'remote' cases than anti-p24 titre. The avidity and titres of these antibodies are presented in relation to the clinical details, p24 antigen status, CD4 and CD8 counts where these are known.Keywords anti-gp41 anti-p17 anti-p24 relative antibody avidity recent infection antibody titre

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.

Fourteen miniature donkeys (Equus asinus) in a mid-Michigan herd of 38 animals presented with clinical signs of besnoitiosis, including the presence of typical tissue cysts in the ocular sclera, the buccal and nasal mucosa, together with characteristic dermatitis in specific areas of the body. The common histopathological change seen was the presence of many 100-200-microm diameter, thick walled, typical Besnoitia sp. tissue cysts together with a chronic cellular response associated with degenerating cysts. Microscopy of isolated scleral cysts and skin biopsies showed the presence of protozoal organisms consistent in morphology with that of Besnoitia bennetti bradyzoites. Molecular analysis of these parasites indicates that they differ from previously described coccidia, including Besnoitia sp., from rabbits and opossums. Isolated cases of infection with this agent have been reported infrequently in equids; however, this is the first report of an outbreak in a herd of donkeys in the United States.