bromochloroacetic-acid and Corynebacterium-Infections

In contrast to wild-type mice, genetically engineered Mucin1 (Muc1) null animals display a marked propensity for development of blepharitis and conjunctivitis. Molecular approaches confirmed the presence of Muc1 mRNA and protein in the conjunctival tissue of wild-type mice and identified the bacterial species in Muc1 null symptomatic mice.. Muc1 null animals housed in a conventional facility were examined for visually apparent inflammation of the eye and surrounding tissue. Blood taken from overtly affected animals was assayed for antibodies to common murine viral agents. Swabs of infected eyes and whole eye preparations were used to detect and speciate bacterial pathogens. Frozen sections of whole eye, lid margin, and Harderian gland were immunostained with antibodies to Muc1 and cytokeratin 14, both epithelial cell markers. Northern blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) were performed on RNA isolated from conjunctiva and Harderian gland of wild-type mice to compare relative levels of transcript.. Student's unpaired t-test performed on the eye inflammation frequency of Muc1 null mice confirmed a statistical significance (P < 0.01) when compared to wild-type background animals housed in the same room. Analysis of blood samples from affected Muc1 null animals detected no common murine viral pathogens. Bacterial analysis of conjunctival swabs and whole eye preparations demonstrated the presence of coagulase-negative Staphylococcus, Streptococcus type alpha, and Corynebacterium group G2. Muc1 antibody staining of wild-type sections revealed the presence of Muc1 on conjunctival goblet and non-goblet cells and on the epithelium of the Harderian gland. Serial sections stained with cytokeratin 14 antibody confirmed the epithelial nature of cells expressing the Muc1 protein. RNA from conjunctiva and Harderian gland subjected to RT-PCR and northern blot analysis showed an abundance of Muc1 transcript in these tissues.. Muc1 mRNA and protein are present in murine conjunctival and Harderian gland epithelia. Animals lacking Muc1 mRNA and protein are predisposed to developing eye inflammation when compared to wild-type animals with an intact Muc1 gene. Muc1 appears to play a critical protective role at the ocular surface, presumably by acting as a barrier to infection by certain bacterial strains.

Topics: Animals; Blepharitis; Conjunctiva; Conjunctivitis, Bacterial; Corynebacterium Infections; DNA Primers; Female; Fluorescent Antibody Technique, Indirect; Harderian Gland; Keratins; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Mucin-1; Polymerase Chain Reaction; RNA, Messenger; Staphylococcal Infections; Streptococcal Infections

The purpose of this study was to characterize a spontaneous disease condition causing hyperkeratosis in nude mice and to explore the etiologic role of a particular species of coryneform bacteria in this disease, colloquially known as "scaly skin disease." The study was divided into two parts. In the first phase, a series of inoculation experiments was conducted with a field isolate of the coryneform species used to study the clinical and histopathologic development of the disease syndrome. Athymic nude mice (4 to 5 weeks old) were inoculated on the skin of the back with a suspension of a pure culture of the coryneform bacterium that had been isolated from a field case. The culture was applied with a sterile cotton swab in concentrations varying from 6.1 x 10(4)/ml to 5.0 x 10(7)/ml. All inoculated mice became persistently infected throughout the 33 days of the experiment. Clinically evident hyperkeratosis in inoculated animals developed more frequently in mice housed in a microisolator cage than in a semi-rigid isolator and more frequently in mice inoculated with higher numbers of organisms. In all animals in which hyperkeratosis developed, it was first noted on day 7 after inoculation. The second series of experiments was designed to determine the success of various housing methods in excluding the infection, mechanisms of transmission, susceptibility of other stocks and strains of mice to the organism, and whether the other strains might serve as a source of the organism. Results of the study in various strains indicated that both immunocompetent and immunodeficient mice, whether glabrous or hirsute, could be infected with the organism, but only glabrous animals developed hyperkeratosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Anti-Bacterial Agents; Corynebacterium; Corynebacterium Infections; Epidermis; Fatty Acids; Female; Keratins; Keratosis; Lactams; Macrolides; Male; Mice; Mice, Nude; Microbial Sensitivity Tests; Rodent Diseases; Skin Diseases, Bacterial