Faculty Bibliography

Lancefield group G streptococcus is now recognized as a pathogen and has been reported to cause severe infections, including meningitis. We describe the first case of meningitis caused by this organism in a patient with acquired immunodeficiency syndrome (AIDS) and the direct transmission of the pathogen to a technologist accidentally exposed to the cerebrospinal fluid. To prove the identity of the two strains, we have tested them employing the Vitek system. We have also tested 13 other strains of group G streptococci obtained from different sources. Our results yielded 14 different biotypes with the 15 strains tested. The only identical ones were the two suspect strains from the index case and the technologist. We conclude that the biotyping system employed in our study appears to be a useful epidemiological tool for marking group G streptococci

We describe three patients with acquired immunodeficiency syndrome who presented with a bilateral coarse superficial epithelial keratitis due to infection with the protozoal parasite Microspora, Encephalitozoon cuniculi. Despite the extent of the corneal surface disease, conjunctival inflammation was minimal. Visual acuity ranged from 20/20 to 20/200. In one patient, the keratitis was complicated by the development of a surface defect with secondary Pseudomonas species infection. All patients had a history of exposure to household pets. Standard cultures were negative. Diagnosis was established in two of the three cases based on characteristic appearance of the protozoan in conjunctival scrapings. Electron microscopy of a conjunctival biopsy specimen in one patient confirmed the species. No recognized effective treatment is available for this infection

Historically, the literature suggests that staphylococcal exoproteins, including enterotoxins, are stimulated by various physicochemical ecologic factors, many of which have been shown to stimulate production of toxic shock syndrome toxin 1 (TSST-1). The propensity of different fibers and other substances to amplify TSST-1 production in toxic shock syndrome-associated strains of Staphylococcus aureus, as well as a comparative analysis of the underlying mechanisms of TSST-1 production, are reported. Two hundred twenty intravaginal devices or other products and materials and 60 experimental controls were examined for their propensity to induce TSST-1 production. Certain materials are superior to unaltered cotton in providing a more absorbent fiber--nutrients are efficiently drawn in, concentrating protein between fibers, and thereby creating an ideal physicochemical environment for the amplification of TSST-1 and other toxins. The greatest stimulation of TSST-1 was observed with (in decreasing order): polyester and carboxymethyl cellulose, polyacrylates, viscose rayon, gelatin foam, polyurethane, and cotton. No toxin was found with nasal tampons (polymer of polyvinyl acetal) or with vaginal cups (an elastomeric polymer). Results are discussed in terms of specific ecologic parameters from historical as well as recent perspectives

Instrument development in microbiology has focused on automating the traditional process of bacterial identification using growth-dependent technology. With the advent of genetic tools, advances in immunology, and engineering innovations microbiologists are moving away from the traditions of culture-dependent technology and are concentrating on the development of rapid, specific, nongrowth-dependent systems with a potential for automation

A prospective comparison of the microbiologic safety of Merocel versus NuGauze nasal packing in 119 surgical patients is presented. Presurgical and postsurgical nasal cultures were obtained, analyzed, and compared. The importance of a preoperative nasal culture isolate of Toxic Shock Syndrome Toxin Number 1 (TSST-1) producing Staphylococcus aureus in predicting postoperative toxigenic S. aureus isolation and Toxic Shock Syndrome symptomatology is demonstrated. An in vitro comparison of the ability of NuGauze and Merocel to amplify TSST-1 production was performed

Synthetic tampons and toxic shock syndrome toxin-one (TSST-1)-producing strains of Staphylococcus aureus have been linked to an increased incidence of toxic shock syndrome (TSS). While recent reports attempt to define the tampon connection as the creation of an optimal environment for the production of TSST-1, the role of other factors in disease expression in an animal model remain under investigation. To understand the role of tampons and bacteria, pools of Swiss mice were inoculated with permutations of effluents from TSS strains of S. aureus and Escherichia coli grown inside tampons. Depending on tampon brand, when all 3 factors were combined mortality ranged from 20-100%. In controls inoculated with single effluents, or effluents from growth in the presence of cotton, no deaths were observed. Likewise, when hairless mice were inoculated with exotoxin, endotoxin, and tampon leachables, mortality was 100%. In the absence of any 1 component, mortality ranged from 0-40%. Lethal toxicity can be the result of enhancement, since animal death in apparent shock was observed in all pools containing the 3 components, and in all pools containing effluents of TSS S. aureus and E. coli grown in the presence of synthetic tampons, but not in their absence. A retrospective analysis of fatal vs non-fatal TSS in humans supports the hypothesis of enhancement