DESCRIPTIONS OF ANTIBIOTICS 



241 



gram-positive and gram-negative t)acteria, certain 

 protozoa, rickettsiae, and the psittacosis group. 

 Not active on fungi. In vitro: Active on strepto- 

 cocci (0.3 to 1.25 ^lg per ml), diplococci (0.1 to 

 0.3 Mg per ml), staphylococci {<0.6 jug per ml;, 

 E. coli, Aerobacler aerogenes (<5.0 ^g per ml), 

 K. pneumoniae (1.0 to 5.0 ng per ml), Hemophihis 

 influenzae (2.0 ng per ml), Brucella suis and B. 

 abortus (<0.75/igpe/'ml), and Actinomyces israelii. 

 Not active at 20 /ig per ml on Pseudomonas or 

 Proteus (11). Active on pleuropneumonia-like 

 organisms (PPLO) (0.23 to 1.25 fxg per ml) (54). 

 Inhibits bacteria-free Tetrahymena and two color- 

 less flagellates at >0.1 ^g per nil. At 0.85 /xg per 

 ml early growth is stimulated (30). Promotes 

 growth of protozoa living on Pohjtomella at 10 to 

 50 ^lg per ml (31), and at a narrow range of con- 

 centration (about 0.1 Mg pf" i"l) ill a bacteria- 

 free culture. At higher concentrations, the pro- 

 tozoa are inhibited (30). Interferes with the killer 

 action of Paramecium aurelia (53). Active on 

 Endamoeba histolytica and T richomonas vaginalis 

 (14). Stimulates growth of ('. albicans at >0.1 

 mg per ml (65). Inhibits CO2 fixation in the dark 

 by Scenedesmus obliquus, but increases sucro.se 

 accumulation and stimulates photosynthesis ui) 

 to si.x times the normal rate at 1.5 X lO^-* M and 

 above (64). Inactive on free coliphage T3, l)ut 

 prevents adsor|)tion and growth of the phage if 

 (he host cell is j)reincubated with subbacterio- 

 static concentrations of the antibiotic. Infected 

 cells are more susceptible to the antibiotic than 

 normal cells (66). Activity adversely affected in 

 presence of serum (2). Growth inhibition of E. 

 coli is reversed by glycine, inosine, lumichrome, 

 and riboflavin; in the case of the latter, competi- 

 tively (67). Resistance develops relatively slowly 

 (2). Anhydrochlortetracycline, although having 

 only a fraction of the antibacterial activity of 

 chlortetracycline, is much more active than the 

 parent compound on actinomycetes (104). In vivo: 

 Active in various animals on Streptococcus pyo- 

 genes, S. hemolyticus, Staph, aureus, D. pneu- 

 moniae, B. anthracis, Erysipelothrix rhusiopathiae, 

 Pastetirella multocida. Listeria monocytogenes, K. 

 pneumoniae, Sal. typhosa. E. coli, Pr. vulgaris, 

 and Ps. pseudomallei (2, 4, 5, 11, 93, 135). Cell- 

 free preparations of ('. albicans, prepared by 

 sonic vibration, are lethal to mice when given in 

 combination with chlortetracycline, but innocu- 

 ous alone (130). Active on Endamoeba histolytica 

 infections in rats, dogs, and rabbits (37, 118), 

 Plasmodium cathemerium in the canary, and P. 

 berghei in mice (38). Some activity on Toxoplasma 

 gondii infections in mice (77). When administered 

 in the diet, it increases the susceptibility of Aedes 



aegypti to /-•. gallinaceuni infections, but decreases 

 it in Anopheles (58) . Active in rats on experimental 

 polyarthritis (PPLO strain L4) (13), and in chick 

 embryos on a PPLO strain causing arthritis in 

 the goat (120). Active in eggs, mice, and guinea 

 pigs on rickettsiae of Rocky Mountain spotted 

 fever, murine, scrub. North Queensland tick and 

 epidemic typhus. North African tick bite fever, 

 Boutonneuse fever, Q fever, and rickettsial pox 

 (8, 28, 103). Active in mice on infections caused 

 by the following viruses: feline pneumonitis (but 

 not in vitro) (18), a gray lung fever (21), mouse 

 hepatitis (32), vaccinia (also active in vitro) (33), 

 Rous sarcoma [in vitro), tested in chickens (47), 

 herpes simplex {in vitro) (111) and the lympho- 

 granuloma-psittacosis group (8). Not active in 

 mice on influenza B, canine distemper, ral)ies 

 street virus, Newcastle disease virus, Venezuelan 

 equine encephalomyelitis, poliomyelitis (MEF-1 

 strain) (8, 52), myxoma virus (chick embryo), 

 fibroma, myxomatosis viruses (rabl)its) (78), or 

 Bittner's milk virus (78). Moderate activity on 

 cat ascarids; no activity on hookworms or tape- 

 worms (79). Anthelmintic activity in mice (57) 

 and horses (83). Protects against hemorrhagic 

 shock in dogs (54). May stimulate Walker car- 

 cinosarcoma (rat) (87). Enhances growth of the 

 following transplanted tumors: rat carcinoma 

 175-0, Crocker rat carcinoma, mouse sarcoma 180, 

 and mouse adenocarcinoma E0771 at 1.6 to 3.2 

 mg per 100 gm of body weight when given for 4 

 to 10 days. At 8 mg per 100 gm for 18 days, com- 

 pletely inhibits some 1- to 3-day transplants of 

 Crocker rat carcinoma, but not 10-day transplants 

 (27). No effect on mammary tumors (C3H mice) 

 or Lucke kidney adenocarcinoma (frogs) (78). In 

 ])lants, chlortetracycline controls, by seed treat- 

 ment, black rot of rutabaga (Xanthomonas cam- 

 pestris) (92). Some control of tomato crown -gall 

 (Agrobacteriuui tumefacieus) (23). Active on bac- 

 teria-free gall tissue (112). Stimulates growth of 

 radish plants (72) and lupine root (Lupinus) (87). 

 Increased growth rate has been reported in the 

 following when chlortetracycline was added to the 

 diet: mice (81); protein-deficient (98) or vitamin- 

 deficient (99) rats; chicks (16); pullets (70); gos- 

 lings (46); geese (100); bobwhite quail (122); tur- 

 key poults (19); lambs (95); weanling (93) and 

 disease-free pigs (97); calves (69, 114); yearlings 

 (69); steers (126); horses (89); cats (91); dogs 

 (48); midernourished children (74); and young 

 men (90). .\lkali-degraded chlortetracycline has 

 no growth-promoting eft'ects in the chick (26). 

 Chlortetracycline is degraded to biologically in- 

 active isochlortetracycline in the rat intestinal 

 tract (133). Dietary chlortetracycline: (a) In- 



