MALTA FEVER AND THE MICROCOCCUS MELITENSIS 381 



MICROCOCCUS CAPRINUS. 



Under this name Mohler and Washburn have described a coccus 

 which is claimed to be the cause of takosis (i. e., a wasting disease of 

 Angora goats). The most characteristic morbid lesions of this affec- 

 tion are emaciation and anemia. Consolidated areas are generally 

 found in the lungs, the myocardium is pale, soft, and flabby, and the 

 epicardium and endocardium may present hemorrhagic spots. The 

 kidneys are anemic and softened and the spleen is small and may be 

 adherent to the neighboring structures. The Micrococcus caprinus 

 has been isolated from the heart's blood. It usually presents itself in 

 pairs, and is pathogenic for goats, chickens, rabbits, guinea-pigs, and 

 white mice, but not for sheep, dogs, or rats. 



MALTA FEVER AND THE MICROCOCCUS MELITENSIS. 



Occurrence and Historical. Malta or Mediterranean fever is a 

 septicemic disease of man, caused by the Micrococcus melitensis, 

 discovered by Bruce in 1887. It is, however, by no means confined 

 to Malta, as cases have been reported from Greece, Italy, Spain, 

 Turkey, North and South Africa, America, India, and the Philippine 

 Islands. The affection is of particular interest to the veterinarian 

 because it is primarily a disease of goats and is transferred through 

 their raw milk to man. 



Morphology. The Micrococcus melitensis is a very small coccus, 

 measuring about 0.4 by 0.3 micron. It is seen as a monococcus or as 

 diplococci, more rarely in short chains. The diameter of the individual 

 stained cocci, according to Bruce, is about 0.33 micron. Longer 

 chains of 10 to 14 cocci are frequently seen in older bouillon cultures. 

 The union of the individual links is evidently not very firm and the 

 chains in stained preparations are broken up into smaller segments. 

 Involution forms, which come to resemble bacilli, are found in older 

 cultures. The organism does not form spores, is not motile, and has 

 no flagella. It stains well with the ordinary anilin dyes, and is Gram 

 negative. 



Cultural Properties. The organism grows best in culture media 

 which are slightly acid to phenolphthalein + 1 (alkaline to litmus). 

 It grows best at blood temperature, but has a wide range of temper- 

 ature. The growth is slow, and it generally requires three to four days 

 before colonies can be seen with the naked eye. The surface of 

 agar plates liberally inoculated after twenty-four to thirty-six hours 

 somewhat resembles ground glass under a low power of the micro- 

 scope. After twenty-four to seventy-two hours individual dewdrop-like 

 colonies are visible. In about eight days they reach a diameter of 

 1.5 mm. They are round, regularly spherical; the superficial colonies 



