MALTA FEVER 71 



plain agar and at room temperature, and does not produce acid in glu- 

 cose media. It not only occurs in the nasal secretions of healthy people, 

 but appears to be responsible for certain coryzas and bronchial affec- 

 tions, resembling influenza. It also is responsible for certain epidemics 

 of conjunctivitis. 



The original cultures may show only slight growth whereas the subcultures 

 prove luxuriant. 



The colonies are larger, more opaque, and have a more irregular wavy border 

 than the round colonies of the Mening&coccus. 



The colony tends to be easily picked up from the plate with the loop. M. catar-7~s; 

 rhalis grows well at 22 C. after several days, while the Meningococcus requires body^""" 

 temperature. It does not ferment with acid production any of the sugars. 



Micrococcus Melitensis (Bruce, 1887). This is the organism of 

 Malta or Mediterranean fever, sometimes called undulant fever, on 

 account of successive waves of pyrexia running over several months. UJ 

 The disease has a very slight mortality (2%), and the lesions are chiefly 

 of the spleen, which is large and diffluent. The organisms can best be (/j 

 isolated from the spleen or blood. 



M. melitensis is only about 0.3^1 in diameter. The characteristics are its very 

 small size and the dew-drop minute colonies on agar, which at incubator temperature 

 only show themselves about the third to the sixth day. It is nonmotile and Gram- 

 negative. In bouillon there is a slight turbidity. Gelatine growth is very slow and 

 there is no liquefaction. Litmus milk becomes more blue after a week so that there 

 is an alkaline action. Indol is not produced. The optimum reaction of media is 

 + 0.8. It grows best at 38C. 



Many laboratory infections have been recorded. 



The organism occurs in peripheral circulation, it having been cultivated from 

 blood very successfully by Eyre. He takes blood at the height of the fever, and in 

 the afternoon. Formerly it was customary to isolate by splenic puncture. 



Infection is chiefly by means of the milk of infected goats. The organisms are 

 excreted in the urine of patients, and a diagnostic point is to make plates from the 

 urine. Such urine applied to abraded surfaces causes infection. 



The serum of patients shows agglutinating power as early as the fifth day of 

 the disease, and this may persist for years after recovery. Nicolle has advised using 

 serum heated to 56C. for thirty minutes for the agglutination test, nonspecific agglu- 

 tinins being thereby destroyed. Carriers may be of importance in Malta fever and 

 are best detected by agglutination tests. 



A high mononuclear increase may be found in this disease. 



Horses, cows, asses, as well as goats, are susceptible. It is very difficult to 

 infect rabbits, mice and guinea-pigs. Monkeys have been chiefly utilized in ex- 

 perimental work. 



It would appear as if there were other organisms closely related to M. melitensis 

 and a great deal is now being written as to confusing serum reaction from the use 

 of M. paramelitensist 



