236 BACTERIOLOGICAL EXAMINATION OF MATERIAL 



The normal nasal cavity, although freely exposed to the exterior 

 and theoretically, at least, continually contaminated with bacteria 

 both from the inspired air and the microorganisms washed from the 

 eyes in the lachrymal secretions, is relatively free from microorganisms. 

 Staphylococcus albus, non-hemolytic short-chain streptococci and 

 pseudodiphtheria bacilli appear to be the more common organisms 

 isolated from the healthy nasal cavity. Material for examination is 

 obtained after cleaning the external nares with sterile salt solution 

 upon swabs of sterile cotton. 



Diphtheria, leprosy, ozena, rhinoscleroma and various coryzas are 

 the common types of nasal infection, but a variety of organisms may 

 be present there either transiently, or somewhat more permanently 

 during bronchial infections. Thus pneumococci, influenza and per- 

 tussis bacilli have occasionally been isolated from the nasal secretion 

 during pneumonia, influenza or whooping cough respectively. Menin- 

 gococci and parameningococci have been demonstrated both in patients 

 and carriers during epidemics of cerebrospinal meningitis. It is not 

 unlikely that Micrococcus catarrhalis has been incorrectly diagnosed 

 as the meningococcus in the past, because both organisms are Gram- 

 negative diplococci. Microcococcus catarrhalis is occasionally found 

 in large numbers in the nasal secretion of acute coryza. 



The bacteriology of ozena is a subject of controversy. Bacillus 

 ozaense and Bacillus rhinoscleromatis, both members of the Mucosus 

 Capsulatus Group of bacteria, have been regarded as the etiological 

 agents in the past. 



The earliest lesion of leprosy appears to be a nasal ulcer, more 

 frequently located at the junction of the bony and cartilaginous septum, 

 hence an examination of the nasal cavity is of paramount importance 

 for the early diagnosis of this disease. 



Tuberculous ulcerations of the nose are comparatively infrequent; 

 the tubercle bacillus is readily distinguished from the lepra bacillus 

 by injection of suspected material into a guinea-pig. The animal 

 is very susceptible to infection with the tubercle bacillus, but refrac- 

 tory to lepra bacilli. Occasionally acid-fast bacilli, which are neither 

 lepra nor tubercle bacilli, have been reported as occurring in the 

 nasal secretion. Karlinski's nasal secretion bacillus is the best known 

 of the Saprophytic Acid-fast Group. It grows promptly and with con- 

 siderable luxuriance upon glycerin agar, which at once distinguishes 

 it from the pathogenic acid-fast bacilli. 



Nasal diphtheria is not an uncommon type of infection with the 



