DESCRIPTIONS OF ANTIBIOTICS 



331 



oil fuiifii. Bacteriostatic (1, 5, 11, 15, 33). Cress- 

 resistance with the other tetracyclines and some 

 with chloramphenicol. Active on Endamoeba 

 hisloli/fica (with or without associated bacteria), 

 Colfjoihi platynematut)), and Tetrahymena pyri- 

 forinis (5, 4ti, 53, 79). Inhibits the killer action of 

 Faraineciinu aurelia (var. 4, stock 51 killer, mating 

 type VII) (31). Certain concentrations stimulatory 

 to some protozoa (53), ChloreUa (101), and some 

 yeasts (59). Active on pleuropnevunonia-like 

 organism (PPLO) strains at O.IG to 0.G3 ;ug i)er ml 

 (30, 32). //( vivo: Active in various animals on 

 Streptococcus hemolyticus, S. pyogenes, D. pneu- 

 moniae, Staph, aureus, B. anthracis, K. pneumoniae, 

 Pasteurella tularensis, P. rnultocida, Sal. typhosa. 

 Sal. choleraesuis, Sal. enteritidis, Sal. ncirport , Sal. 

 lyphimuriunt, H. influenzae, H. pertussi.'i, Br. 

 nielitensis, Bartonella muris, Listerella iiioni)- 

 cytoqenes, Spironema duttoni, Borrel'a recurrentis, 

 B. novyi, V. comma, Clostridium septicum, CI. 

 tetani, and M. tuberculosis. Moderately active on 

 Erysipelothrix rhusiopathiae and Sal. gallinarum 

 (1, 5, 6-9, 11, 13, 20, 33, 34, 46, 62). Active on 

 Endamoeba histolytica (rats and dogs) (94), 

 Plasmodium gallinaceum (chicks), P. cathemerium 

 (canaries), P. berghei (mice) (35), and Eperylhro- 

 zoon coccoides (mice) (44). Limited activity on 

 toxoplasmosis (rabbit and mouse) (78). Active on 

 arthritis-producing PPLO (L4 strain) in rats (12). 

 Active on Rickettsia tsutsugamushi, R. prowazekii, 

 R. akari, R. rickettsii, R. burneti, and Neorick- 

 ettsia helmintheca (5, 77). Has a selective toxicity 

 on the growth of coliphage T2 (102). Active on the 

 agents of jjrimary atypical pneumonia, infectious 

 synovitis (chickens), granuloma inguinale, and 

 lymphogranuloma venereum (5, 95), as well as the 

 mouse and feline pneumonitis and sheep abortion 

 organisms (16, 21, 68). Active on Rous sarcoma 

 cells and infective extracts in contact tests (42). 

 A minimal tolerated dose of 150 mg ])er kg moder- 

 ately inhibits sarcoma 180 and carcinoma 1025 

 (mice) (87). Not active on viruses (10, 47). Rule 

 in nutrition: (See chlortetracycline for general 

 discussion.) Added to the diet, oxytetracycline 

 increases growth rate of: rats (on a nutritionally 

 deficient diet) (70); chicks (28); germ-free chicks 

 (71); pheasant chicks (63); turkey poults (25); 

 dairy calves (on a limited milk diet) (75); steers 

 (73); weanling pigs (72); human infants (slight 

 effect) (106); but not rabbits (64). Improves: Feed 

 efficiency; egg production and egg hatchability in 

 laying hens (41, 88); feed consumption and ef- 

 ficiency in calves (limited milk diet) (75). 7h- 

 i-rc(tsc.'<: liiotin, folic acid, and vitamin B12 in the 

 cecal contents of normal, l)Ut not germ-free l)irds 



(71); nicotinic acitl concentration in the liver of 

 cats (74); and blood sugar levels in dairy calves 

 (76). Plants: Oxytetracycline is widely used in 

 combination with streptomycin in controlling cer- 

 tain plant diseases. Alone, it is active on fire 

 l)light (Erivinia amylovora) of apples (51), bac- 

 terial spot iXanthomonas pruni) of peach trees 

 (52) , Stewart's corn wilt {Bacterium stewartii) (89) , 

 leaf blight of corn {B. carotovornm f. zeae) (92), 

 cucumber wilt (E. tracheiphila) (90), and crown- 

 gall (Agrobacterium tumefaciens) of cherry (103) 

 and geranium ((iO). Active on crown-gall tissue 

 (rose) (82). Like chlortetracycline, oxytetra- 

 cycline has been reported to have activity on 

 certain i)lant diseases caused by fvmgi, in spite of 

 its known lack of activity in vitro against these 

 organisms. These diseases include leaf spot phase 

 (H elmi nthosporium vagans) of Kentucky blue grass 

 (97) and downy mildew of cucumber {Pseiido- 

 peronospora cubensis) (98). (Jxytetracycline has a 

 vitamin-sparing action (Bi) on virus tumor tissue 

 of Rumex acetosa (48). It stimulates growth of 

 young corn seedlings, sorrel (43), wheat roots (29), 

 radishes, cucumbers (48), and a spinach-like plant 

 (55). Stimulates germination, sprout and toj) 

 growth of oats, and germination and top growth of 

 Madrid sweet clover (55). Miscellaneous: Applied 

 to fallow plots, increases bacterial and actino- 

 mycete counts, but decrea-ses fungal popvUation. 

 Increases nodvdation of sweet clover roots. Ni- 

 trates accumulate more rapidly in iincropped, 

 antibiotic-treated soils than in water-treated 

 soils. This effect is reversed in cropped, antibiotic- 

 treated soils (55). Stimulates spermatogenesis in 

 the rat (45). 



Toxicity: .\nimfil.'<: Base: LDso (mice) >3500 

 mg per kg subcutaneously, >5200 mg per kg orally 

 (3), and 100 mg per kg intravenou'-ly (15). Hy- 

 drochloride (expressed as mg of base per kg) : LD50 

 (mice) 178 to 192 mg per kg intravenously, 600 to 

 892 mg per kg subcutaneously, and 6690 to 7200 mg 

 per kg orally (3, 4, 15). LI),,,, (rats) 280 mg per kg 

 intravenously (3). LDmi (10-day-old chick em- 

 bryo) 10.9 mg, via allantoic (105). Highly toxic to 

 guinea pigs, i)roducing toxic symptoms at doses 

 as low as 2.5 mg, orally or intramuscularly (7). 

 Sulfate: LD50 (mice) 165 mg per kg intravenously, 

 and 600 mg per kg sul)cutaneously. Xa salt (pH 

 8.5): LD 50 (mice) 150 to 175 mg per kg intravenously; 

 270 to 300 mg per kg sulicutaneously, and 4410 mg 

 per kg orally (3, 4). Plants: Inhiliits root growth 

 (percentage of control) of the following plants at 

 100 ppm; mustard (34 per cent ), red clover (39 per 

 cent), cucvmil)er (19 per cent), and wheat (38 per 

 cent) (80). Toxic to root growth of Lupiniis albus 



