DIPHTHERIA IN THE TROPICS 243 



6. Glycerine-blood-agar. In 1910, Mandelbaum and Heinemann^ described a special 

 plate method for distinguishing the true B. diphtheria} from pseudo forms. It was 

 thought well to apply this test to our cocco-bacillus, and it was found that it presented 

 colonies in all respects like those described and figured by the German observers 

 for the true Klebs-LcBffler bacillus. 



A single inoculation experiment was performed, 1 c.c. of a 24-hours' culture grown Inoculation of 

 at 37' C. in sugar-free broth being inoculated on December 30, 1909, subcutaneously into ^ g"'"'==i"P'S 

 a young guinea-pig weighing 40 grammes. The broth was prepared by Spronck's first 

 method.- There was no effect locally or constitutionally. Although, as a rule, the chief 

 stress has to be laid on the animal inoculations when investigating any diphtheria-like 

 bacillus, still, in this instance, one could not hope to gain much information from them 

 as the strain was derived from a very mild case and was clearly not of a virulent type. 

 Moreover, it had been subjected to the action of formamiut and had been sub-cultivated 

 for some time. The man was, indeed, more of a carrier than a patient, although the 

 case, from which presumably he derived his infection through the medium of laboratory 

 cultures, was rather severe. The latter was, however, a complex infection (vide page 245) . 

 A paper by Arkwright in the British Medical Journal for November 12, 1910, on diphtheria 

 carriers and bacilli allied to, but distinct from, the true Klebs-Lceffler bacillus is well 

 worthy of study in relation to this case. 



So far as morphology and cultural characteristics go this cocco-bacillus was 

 undoubtedly B. diphtherias, but I found it hard to believe that two distinct forms — one 

 coccal, the other bacillary — could exist, and that each to some extent could be transformed 

 by appropriate cultivation into the other. The fact remains that such was the case. So 

 far as I can see there was no possibility of error, and Captain Archibald, who on his return 

 from leave, saw something of the work and all the microscopic slides, is satisfied that the 

 facts are as stated. It will be evident that it is important to confirm or refute these 

 observations, for, if cocci alone were found in a throat swab, a case of diphtheria might 

 easily be overlooked. So might carrier cases, for it would appear that the organism tends 

 to assume the coccal form only under certain conditions, one of which may possibly be 

 a diminution in virulence, and another, a free supply of oxygen or the special reaction of 

 the culture medium. It is interesting to note that the whole question of variation in 

 bacteria is coming prominently to the front and one of the most variable is B. diphtherias, variation in 

 This question is much too large to be discussed here. Eeference is made to it in our Second diphtheria 

 Eeview, but one may note a paper by Bordet and Sleeswyk^ on the changes induced by r^^orded 

 cultivation on different culture media, and the recent researches of Cappellani'' who has 

 found in the throats of diphtheria patients filamentous forms which on culture change 

 to the classical rod shape. The two German papers, already mentioned, are of special 

 interest and describe a condition resembling in some respects that found in the Sudan. 

 I did not see them until after this paper was in print. 



I now give in greater detail a list of the observations made from day to day on the 

 cultural forms of this cocco-bacillus. 



December 15, 1909. Swab. Film yielded only Gram-negative cocci with faint 

 metachromatic granules. 



' Mandelbaum, M., aud Heinemann, H. (1910), " Beitrag zu Differenzierung von Diphtherie-und 

 Pseudodiphtherie baoillen." Ceyit. fur Bakt. Orig. Bd. 53, H. 3. 



- Quoted in The Bacteriolorjy of Diphtheria, loc. cit. 



" Bordet, J., and Sleeswyk, J. (June 25, 1910), " Serodiaguostic et variabilite des microbes suivant le milieu 

 de culture." Ann. de I'Insi. Piisteur. 



* Cappellani, S. (1910), " SuUc ramitieazioui del bacillo di Loffler." Ann. Iij. xpcriia, Vol. xx., No. 3. 



