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Biomedical subjects

W G Strauss

Publications and source records attributed to W G Strauss.

At least 19 recordsLinked to original sources
PubMed1983

Competitive adherence as a mechanism of bacterial interference.

To determine whether competition among bacteria for specific attachment sites on host cells can explain bacterial interference, Staphylococcus aureus strain 502A was tested in turn against two different nasal coryneforms, a strain of Pseudomonas aeruginosa, and a virulent strain of S. aureus, all in the presence of nasal mucosal cells. Particularly examined was the influence of sequence in which bacteria were presented to the nasal cells in comparison with initial mixtures and individual suspensions. Results paralleled those observed in clinical prophylaxis: the bacterium first to adhere to the epithelial cells was able, under uniform conditions, to interfere with the colonization of subsequently added bacteria. Secondary adherence was not eliminated but substantially reduced, and was probably related to steric blockage by the initial colonizer and its particular ability to dissociate from the host cell.

Adhesiveness↗
PubMed1982

Importance of the keratinized epithelial cell in bacterial adherence.

The effect of cellular pathology and keratinization of skin and nasal cells upon binding of Staphylococcus aureus were examined. Adherence with epithelial cells obtained from either the skin or nasal mucosa of patients with atopic dermatitis was greater than that observed with normal cells (p less than 0.001); the difference in adherence between psoriatic and normal cells was not statistically significant. Tested nasal cells were microscopically differentiated into 4 general types based on stage or layer of keratinization: spinous, low granular, high granular, and keratin. The degree of adherence was related to the progress of keratinization. Data indicated the existence of 2 types of receptors for S. aureus on nasal cells: One, present upon both granular and fully keratinized cells, is not blocked by teichoic acid and appears responsible for the higher bacterial counts on atopic cells; the second is found on keratinized cells only and is susceptible to teichoic acid.

Adhesiveness↗
PubMed1977

Bacterial adherence to nasal mucosal cells.

The ability of several bacterial species to adhere to human nasal mucosal cells and their distribution on nasal mucosal surfaces was studied. Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, and Pseudomonas aeruginosa adhered to scraped nasal mucosal cells. In contrast, viridans streptococci and Klebsiella pneumoniae exhibited feeble or no adherence to nasal mucosal cells. S. aureus affinity for the nasal mucosal cells of carriers of S. aureus was greater than for those of the noncarriers (P less than 0.005). Heat treatment of S. aureus did not block, but slightly reduced, its binding to mucosal cells. The data suggest a high degree of specificity involved in the adherence of bacteria to nasal mucosal cells. The greater affinity of S. aureus for the nasal mucosal cells of carriers (than noncarriers) seems to be a property of mucosal cells rather than bacteria.

Antigens, Bacterial↗
PubMed1970

Effects of a systemic antibiotic on nasal bacterial ecology in man.

The nasal flora of coagulase-positive staphylococcus carriers and noncarriers was studied in aerobic conditions in 17 individuals. Five hundred milligrams of cephalexin was given orally four times daily for 12 days, and its effects on the nasal bacteria were determined quantitatively before, during, and after treatment. The total count obtained before the drug treatment was 5.4 x 10(6) in carriers and 3.9 x 10(6) in noncarriers. The lowest total count observed was 3 days after the cessation of the drug. The increase in gram-negative rods was seen 9 days after antibiotic therapy, not during the greatest reduction of gram-positive bacteria. Coagulase-positive cocci and diphtheroids were most sensitive to drug treatment. After 36 days, the total count was restored to pretreatment level. Diphtheroids did not return to the original number and were replaced by a corresponding increase of resistant coagulase-negative cocci. An inverse relationship between coagulase-negative cocci and lipophilic diphtheroids was seen in the anterior nares of many individuals. No gross difference in nasal ecology to differentiate carriers from noncarriers was seen.

Administration, Oral↗