334 Microbes and You 



supplies in biological warfare attacks. Since the toxin is not an 

 agent that is communicable, invading armies would not have to 

 fear the spread of this substance to their own troops. 



THE GRAM NEGATIVE COCCI 



Paired, gram negative cocci with adjacent sides flattened. 

 Aerobic and anaerobic species. Non-motile. Some grow poorly 

 or not at all without mammalian body fluids. Optimum tem- 

 perature of 37° C. Parasites of mammals. Genus Veillonella 

 occurs in masses, rarely in pairs, and is anaerobic. 



The two important species in the genus Neisseria are Neisseria 

 gonorrhea, the cause of gonorrhea, and Neisseria meningitidis, the 

 etiological agent of epidemic meningitis. Albert Neisser dis- 

 covered the microbes responsible for gonorrhea while examining pus 

 from an infected individual in 1879, and the genus has been named 

 in his honor. 



Neisseria gonorrheae 



These organisms are spheres measuring between 0.6 and 1.0 

 micron, occurring singly but more usually in pairs, and where 

 the two cells come together, the sides are flattened, giving a coffee 

 bean appearance. Primarv cultivation is enhanced by growing 

 the cultures under an atmosphere containing about 10% of carbon 

 dioxide. 



Man appears to be the only animal for which the gonococcus is 

 a natural pathogen. Gonorrhea is one of the most common of 

 the venereal (from Venus, the goddess of love) diseases, and 

 the infection is contracted almost exclusively by sexual contact 

 with infected individuals, particularlv prostitutes. The extreme 

 sensitivity of these pathogens to drying and to minor temperature 

 changes on either side of 37° C. minimizes the opportunity for their 

 spread by means of fomites, including toflet seats. There is some 

 evidence that infected bed linen, night clothes, and towels have 

 been responsible for a small number of cases of the disease when 

 the contact with the viable discharges was almost immediate. 



Many persons consider gonorrhea "no worse than a bad 



