70 Infection 



maximus, Leptothrix buccalis maxima, lodococcus vaginatus, Spiril- 

 lum sputigenum and Spirochaeta dentinum (denticola) — in every 

 mouth. Practically the same conclusions were reached by Vin- 

 centini. * These organisms are peculiar in that they will not grow in 

 artificial culture. In addition to this permanent ilora, Miller culti- 

 vated fifty- two other species, some of which were harmless, some well- 

 known pathogens. 



From the mouth these organisms may be traced into the pharynx 

 and esophagus. 



In studying the micro-organisms of dental caries Goodbyf found 

 a large number of organisms which he divided into three groups: 

 A; Those that produce acids, including Streptococcus brevis. Ba- 

 cillus necrodentalis (Goodby), Sarcina alba, Sarcina lutea, Sarcina 

 aurantiaca. Staphylococcus pyogenes aureus, and Staphylococcus 

 pyogenes salivarius (Biondi). B. Those that liquefy blood-serum: 

 Bacillus mesentericus rubra, B. mesentericus vulgatus, B. mesenteri- 

 cus fuscus. Bacillus fuscus, a yellow bacillus, probably B. gingivte 

 pyogenes (Miller), and Bacillus liquefacium motilis. C. Those that 

 produce pigment, including the same organisms as group B. In ca- 

 rious dentine two organisms, Streptococcus brevis and Bacillus 

 necrodentalis, were invariably present. 



The extinction of the great number of bacteria entering the mouth 

 is referred by most bacteriologists to a bactericidal action of the 

 saliva. 



The stomach seems to retain very few of the many bacteria that 

 must enter it, its persistently acid contents being inimical to their 

 development. Certain sarcina, especially Sarcina ventriculi, may be 

 found without any considerable departure from the normal state. 

 In carcinoma and other forms of pyloric obstruction with dilatation, 

 the bacterial flora increases, and in achlorhydria micro-organisms 

 of fermentation make their appearance. They are, however, acci- 

 dental and not permanent tenants of the organ. 



In carcinoma of the stomach a bacillus, probably one of the lactic 

 acid groups, early makes its appearance and is of some diagnostic im- 

 portance. It is called after its discoverer the Oppler-Boas bacillus,! 

 also on account of angulations found in its threads, Bacillus gen- 

 iculatus. It is a large bacillus, tending to form long threads easily 

 seen without an oil-immersion lens. It is probably non-motile, does 

 not form spores, stains by Gram's method, and is said by Emory§ 

 to divide longitudinally as well as transversely. This, as he says, will, 

 if proved to be correct, be a most important means of identifying the 

 species. Cultures are easily made in media acidified with lactic acid. 



The intestine receives such micro-organisms as have survived what- 

 ever destructive influences the gastric juices may have exerted, and 



* " Bacteria of the Sputa and Cryptogamic Flora of the Mouth," London, 1897- 

 t Transactions of the Odontological Society, June, 1899. 

 j" Deutsche med. Wochenschrift," 1905, No. 5. 

 § "Bacteriology and Hematology," p. 114. 



