ANTI-ENZYME IMMUNITY 295 



5. Staphylococcal and Other Bacterial Factors in Fibrin 

 Clot Formation 



It has been known for several decades that certain staphylococcal 

 strains produce a factor which promotes the formation of fibrin clot. 

 During the last decade several reports have shown that other bacterial 

 species elaborate a similar factor. This factor has been called 

 "Coagulase." For reasons stated at the beginning of Section C, and 

 also in view of the inadequacy of available information concerning its 

 chemical nature and its role in fibrin clot formation, the term coagulase 

 seems to be a misnomer. We prefer to call it, at present, a Clotting 

 Factor to be used exclusively in discussions pertaining to plasma clot- 



a. Distribution of Plasma Clotting Factor among Bacteria. 



StafhylococcMS aureus Qfjogenes^ has principally been studied as a 

 good producer of clotting factor. Sta'phylococcus alhiis has been re- 

 ported variously to possess or lack this ability. Reed, et al. (1943) 

 studied several gas gangrene species with respect to their ability to clot 

 plasma. Some 25 cultures belonging to the six most important gas 

 gangrene species: CI. welchii, Ch seyticum, CI. novyi, CI. sordelUi, 

 CI. sporogenes and CI. histolyticum were tested for ability to clot 

 guinea pig plasma by the methods ordinarily employed with staphylo- 

 coccus cultures. Two of five cultures of CI. novyi and one of five 

 cultures of CI. se-pticum regularly produced rapid clotting; CI. histoly- 

 ticum and CI. sforogenes produced slow clotting. Other cultures failed 

 to produce clotting. On the basis of these results, these investigators 

 concluded that plasma clotting is not a significant characteristic of this 

 group of species. However, the experiments of Reed, et al. may merit 

 reinvestigation by taking into consideration several factors not consid- 

 ered during their experimentation, since experiences of other workers, 

 and particularly those of Smith and Hale (1944), to be discussed 

 below, indicate that guinea pig plasma is unsatisfactory when used in 

 testing for the presence of clotting factor. 



b. Anti-clotting Factor. Several investigators have reported the pro- 

 duction of another factor by bacteria which interferes with or inhibits 

 blood clotting. Dennis and Berberian (1934) discussed the relation 

 of this factor to inflammatory fixation of various strains of streptococci 



