INFLUENZA III 



composed of organisms showing various functions; Prcteus vulgaris liquefying gelatin 

 rapidly, P. mirabilis slowly and P. zenkeri not at all. The differentiation of the colon 

 group is extensively considered under bacteriology of water. 



GRAM-NEGATIVE BACILLI REQUIRING SPECIAL MEDIA 



Bacillus Influenzas (Pfeiffer, 1892). This organism is the type of the 

 so-called haemophilia bacteria organisms whose growth is restricted 

 to media containing haemoglobin. The influenza bacillus seems to grow 

 better on slants freshly streaked with blood than on those which have 

 been made for some time, and they appear to grow better on this sur- 

 face smear of blood than on a mixture of agar and blood. 



The influenza bacilli are most likely to be isolated from the sputum of broncho- 

 pneumonia due to this organism. It has also frequently been found in the nasal 

 secretions of influenza patients. Exceptionally, it is present in the blood, and has 

 been isolated in cases of meningitis from cerebrospinal fluid. It also occurs at times 

 in anginas, but then usually associated with other organisms. Infection probably 

 only takes place by contact. It is a very small bacillus which in sputum tends to 

 show itself in aggregations, especially centering about M. tettragenus. It stains rather 

 faintly when compared with cocci, so that a smear of sputum stained with formol 

 fuchsin shows a deep violet staining for the M. tetragenus or other cocci, and scattered 

 around in a clump-like aggregation we see these minute, rather faintly stained rods. 

 They also tend to stain more deeply at either end, so that they sometimes appear 

 as diplococci. Gram's method, counterstaining with formol fuchsin is excellent for 

 their demonstration. The red bacilli and the violet-black cocci are easily dis- 

 tinguished . 



To cultivate them, rub the sputum, or at autopsy the material from 

 a lung, on a slant smeared with human blood (pigeon's blood is also 

 satisfactory), and then without sterilizing the loop, inoculate a second 

 blood slant; then a third, and possibly a fourth. 



The colonies appear as very minute dewdrop-like points which seem to run^into 

 each other in a wave-like way. To test such colonies we should transfer a single 

 colony to plain agar and blood-serum, trying not to carry over any blood. If the 

 least trace of blood is carried over, they may grow on agar or blood-serum. Organ- 

 isms resembling the influenza bacillus have been isolated from whooping-cough. 

 Such organisms have also been found in the fauces of well persons. In many 

 epidemics of influenza the bacillus has not been isolated, or success has obtained in 

 only a small proportion of the cases. Etiological factors in conditions more or less 

 resembling influenza may be the Streptococcus, Pneumococcus, or M. calarrhahs. 

 The influenza bacillus seems to grow best in symbiosis with some other organism, 

 especially with S. pyogenes aureus. 



Koch-Weeks Bacillus (Koch, 1883). This produces a severe con- 

 junctivitis. It is very common in Egypt and is also a frequent cause 

 of conjunctivitis in the Philippines and in temperate climates. 



