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Biomedical subjects

A N James

Publications and source records attributed to A N James.

21 records · Page 2Linked to original sources
PubMed1976

Attachment of gonococci to sperm. Influence of physical and chemical factors.

Neisseria gonorrhoeae of pilated T1 and nonpilated T4 colony types attached themselves to human sperm in greatest numbers and most reproducibly when suspensions of the cells were incubated at 35 degrees C in Ringer's solution, pH 6-8. After incubation for 15 or 30 min. in a water bath shaker, 50 per cent. of human sperm had T1 gonococci attached and 25 per cent. T4. Sperm and both types of gonococci were pre-incubated separately with various chemical agents, selected because the agent is found in genital fluids, or has a known effect on bacterial cell walls or sperm membrane. After treatment, sperm were washed or were not washed, and were then tested for attachment by mixture with untreated gonococci. Treated gonococci were handled in the same manner. Change in the percentage of attachment was defined as deviation from the range expected on the basis of a standard curve. Treatment of sperm with the nucleotides, ATP or cAMP, curtailed attachment by T1 gonococci but had no effect on attachment by T4.

Adenosine Triphosphate↗
PubMed1973

Variation in colonial morphology of Neisseria gonorrhoeae after growth on media containing antimicrobial agents.

Stable colonial types 1, 2, 3, and 4 were prepared from eight strains of Neisseria gonorrhoeae. Four of the strains, termed laboratory strains, had been transferred over 100 times; three strains, termed clinical strains, were transferred only three to five times after isolation from patients, and one stabilized clinical strain was transferred purposefully 30 times after isolation from a patient. Colonial types of the three categories were grown on four media containing the following agents at the level used in diagnostic media: (i) vancomycin, colistin, and nystatin; (ii) these antibiotics plus trimethoprim lactate; (iii) trimethoprim lactate alone; and (iv) a control with no antimicrobial agents. When grown on media containing the antimicrobial agents, colonial types 1, 2, and 3 of all strains showed specific and consistent changes that precluded accurate identification of the types. In general, the colonies were smaller, more dense to transmission of light, and more granular than colonies grown on control medium. More colonies showed these type changes in the clinical strains and on media containing trimethoprim lactate. Colonies of type 4 showed little or no change. The changes in colonial morphology of types 1, 2, and 3 were pronounced enough to make colony typing difficult if the antimicrobial agents, particularly trimethoprim lactate, were present in media.

Colistin↗