[Doxycycline treatment of experimental legionellosis in guinea pigs infected by aerosol].
The efficacy of curative and preventive treatment by doxycyclin was studied with the same experimental model as during the study of erythromycin [14]. The infectious aerosol was done with a strain of Legionella pneumophila serogroup 1, Philadelphia (ATCC 33152). Male albinos Dunkin-Hartley guinea-pigs were exposed for 30 min to an aerosol dose of 1, 10 or 100 LD 50 (10(3), 10(4) or 10(5) viable organisms). After preliminary assays to find out the efficient posology, doxycyclin was administered intraperitoneally (IP) 18 h after the infection at a dosage of 60 mg/kg/day for 5 days in the animals infected with 1 LD 50, and 75 mg/kg/day in the animals with 10 and 100 LD 50. The preventive treatment (75 mg/kg/day) administered one day before and the day of the infection was tested with animals infected with 10 LD 50. The guinea-pigs were observed 8 days (weight, rectal temperature) and watched over 3 weeks after the end of treatment; serological and bacteriological tests (cardiac blood, lungs, spleen) were performed in every animal; doxycyclin assays (serum, lungs) during treatment were performed by high performance liquid chromatography (HPLC). The treatment of guinea-pigs infected by 1, 10 and 100 LD 50 gave a survival rate of 100%, 75% and 50% respectively. On the other hand the animals which received preventive treatment were all survivors. Seroconversions with antibody titres from 64 to 512 were observed for all the survivors. Bacteriological tests were all negative. The mean doxycyclin concentrations in serum (microgram/ml) and lung (microgram/g) were 1.66 and 11.42 after 24 h of treatment and 5.71 and 18.93 after 7 days.(ABSTRACT TRUNCATED AT 250 WORDS)
Nowicki
M
M
Laboratoire National de la Santé, Centre National de Référence de Légionelloses, Faculté de médecine Alexis-Carrel, Lyon.
Paucod
J C
JC
Bornstein
N
N
Meugnier
H
H
Freney
J
J
Isoard
P
P
Fleurette
J
J
D000336:Aerosols; D000818:Animals; D004318:Doxycycline / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use*; D006168:Guinea Pigs; D007877:Legionnaires' Disease / Q000188:drug therapy* / Q000382:microbiology; D008168:Lung / Q000378:metabolism; D008297:Male
D000336:Aerosols; D004318:Doxycycline
Traitement par la doxycycline de la légionellose expérimentale du cobaye infecté par aérosol.