Anti-vRE and anti-MRSA activities of new quinolones and their synergism with commercial antibiotics. Part 2.
Anti-VRE and anti-MRSA activities of new quinolone derivatives [The two quinolone derivatives are 8- [3-[(ethylamino) methyl]-1-pyrrodinyl] -7-fluoro-9, 1-[(N-methylimino)methano]-5-oxo-5H-thiazolo[3,2-a]quinolone-4-carboxylic acid (compound A) and 7-fluoro-8-morpholino-9,1-[(N-methylimino) methanol-5-oxo-5H-thiazolo [3,2-a] quinolone-4-carboxylic acid (compound B)] and their synergism with commercial antibiotics were investigated. Compound A exhibited potent antibacterial activity against VRE and MRSA among the five new quinolone compounds tested, and showed superior activity to pefloxacin, ofloxacin and levofloxacin, which are clinically in use these days. With respect to the anti-VRE activity, compound A showed synergism with fosfomycin (FOM), and partial synergism with ampicillin (ABPC), gentaicin (GM), minocycline (MINO) and vancomycin hydrochloride (VCM). Partial synergism in anti-VRE activity was also observed between compound B and GM, MINO, FOM and VCM. Compound A also showed synergism with MINO and FOM in anti-MASA activity. Partial synergism was observed with ABPC, GM and VCM. Synergism with ABPC was not detected in anti-MRSA activity. On the other hand, the synergism of compound B with FOM, and the partial synergisms with ABPC, GM and MINO were also found against MRSA. No synergism with ABPC was found against MRSA. These results suggested that compound A and B could possibly reduce the daily administration dose of these antibiotics in the treatment of nosocomial infections, and also reduce the possibility of the occurrence of nosocomial infections caused by VRE and/or MRSA.
School of Agriculture, Kinki University, Nakamachi 3327-204, Nara 631-8505, Japan.
Yoshikazu
Y
Sakagami
Sadao
S
Komemushi
Goro
G
Tsukamoto
Hirosato
H
Kondo
Akiko
A
Yoshikawa
Osamu
O
Muraoka
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004357:Drug Synergism; D016983:Enterococcus / Q000187:drug effects*; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D015363:Quinolones / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects*; D020713:Vancomycin Resistance
D000900:Anti-Bacterial Agents; D015363:Quinolones