The Effect Of Different Environmental Conditions On Some Characters Of Haemophilus Paraphrophilus

V-dependent growth of Haemophilus paraphrophilus, which Zinnemann et al. (1968) found to take place only when cultures were incubated in air with 5–10 per cent. added CO2, or on a medium containing 0.6 per cent. NaCl, also takes place in the absence of either of these conditions if the cultures are incubated in a closed, moist atmosphere, as in a sealed plate or a sealed jar.

The findings here described do not provide arguments against recognition of the species Haemophilus paraphrophilus, since under conditions of normal humidity and air supply the unadapted, recently isolated strains grow sparsely, or not at all. Typical coccobacillary rods are formed only when cultures are grown in an atmosphere with added CO2 as well as an increased moisture content.