Hassan A. Gaafar

Screening for Trichomonas vaginalis infection by use of acridine orange fluorescent microscopy.

The acridine orange test for detection of Trichomonas vaginalis in smears has been adapted for delayed examination of specimens. Mailed-in slides stained by acridine orange were compared with on-site wet mounts; the acridine orange test detected 96% of all positives, whereas only 76% were detected by wet mounts. In a similar comparison with Papanicolaou smears, the acridine orange test detected 89% as compared with 67% detected by Papanicolaou smears.

Bacteriocin Production by Neisseria gonorrhoeae

Seventeen apparently unrelated isolates of Neisseria gonorrhoeae out of 2,123 tested produced a diffusible growth-inhibitory substance against other gonococci. The inhibitor was destroyed by trypsin, not blocked by bovine serum albumin, and not soluble in chloroform-methanol; each isolate was resistant to the inhibitor it produced. Thus, the substance differs from previously described gonococcal inhibitors, and since it fits the description of a bacteriocin we designated it gonocin. The use of gonocin for typing was complicated by the observation that susceptibility to gonocin appears to depend on the gonococcal colony type. Images

Specificity of Macrophage Receptors

Summary Mouse peritoneal macrophages possess receptors specific for IgG. These receptors differentiate between self and foreign IgG but not between IgG from different heterologous species.