Hog's gastric mucin as an aid in the isolation of N. gonorrhoeae.

A diagnosis of gonorrhoea can only be made with certainty by the isolation of N. gonorrhoeae. The reliance for diagnosis on stained films alone has been shown by De Bord (1939), Ewing (1949), Schaub and Hauber (1948), and others to be too uncertain to be accepted as proof of infection. Moreover, cultural methods yield a higher proportion of positive results, especially in chronic cases (McLeod, Coates, Happold, Priestley, and Wheatley, 1934; Eldering and Palser, 1946). Unfortunately, the gonococcus is often very difficult to cultivate from pathological material, and it is certainly the most difficult member of the Neisseria group to isolate. Many factors have to be carefully considered, e.g., pH and consistency of medium, temperature, carbon dioxide content of environment, and so on. While these conditions can be fulfilled in large central bacteriological departments, they may place a heavy burden upon the personnel of smaller subsidiary laboratories. Again, clinics may be sited some distance from the parent laboratory, and the bacteria may not survive transportation. It would, therefore, be of advantage to have a medium which could maintain the organism in transport over long distances with fluctuations in temperature en route. The essence of such a medium should be that it is simple to prepare and easy to handle. Many substances have been advocated for their growth-promoting action towards N. gonorrhoeae. Blood, serum, and ascitic fluid have long been regarded as essential ingredients of media, and an atmosphere of carbon dioxide is usually regarded as necessary for satisfactory cultivation. It was reported by Glass and Kennet (1939) that charcoal (heated to 1,000 C. to destroy organic matter) could replace blood. Starch has been used by different workers (Gould, Kane, and Mueller, 1944; Peizer, Steffen, and Klein, 1949). Media have been suggested for maintaining the gonococcus in transport. Cooper, Mayr-Harting, and McLachlan (1950), used a crystal violet blood mixture and later thallium acetate blood mixtures; Moffett, Young, and Stuart (1948), used thioglycollic acid, sodium glycerophosphate, calcium chloride, and methylene blue; Stuart (1946) used a non-nutrient medium with sodium thioglycollate; and Eldering and Palser (1946) used proteose No. 3 agar and haemoglobin medium (Difco). Most of the media suggested are rather complex, and therefore a simpler medium with less rigorous requirements of cultivation would be an advantage. While carrying out studies on the growth-promoting action of hog's gastric mucin towards the meningococcus (Maccabe and King, 1951) one wondered what effect mucin might have on the growth of another member of the Neisseria group-N. gonorrhoeae. This paper illustrates the effect of mucin on the growth of the gonococcus, using, in the first instance, pure cultures of the organism and, secondly, pathological material from cases.