In vitro antiseptic susceptibility of clinical isolates from nosocomial infections.
To evaluate the susceptibility of a large number of strains to various antiseptics, we elaborated a simple, qualitative broth turbidity method in which we could quickly judge the efficacy visually. For this method, we prepared a modified neutralizer broth, consisting of trypticase soy broth containing 15% Tween 80, 1% soybean lecithin and 0.5% sodium thiosulfate. The susceptibilities of Serratia marcescens No. 26 to 4 antiseptics obtained from the turbidity method showed a good agreement with those obtained from the colony-counting method; the 4 antiseptics tested were povidone-iodine (PVP-I), chlorhexidine gluconate (CHG), benzalkonium chloride (BAC) and alkyldiaminoethylglycine hydrochloride (AEG). Both PVP-I and BAC had complete efficacy in 0.5 min against all isolates tested [100 isolates of S. marcescens, 103 of Klebsiella pneumoniae, 99 of Pseudomonas aeruginosa, 19 of Alcaligenes faecalis and 30 of A. xylosoxidans subsp. xylosoxydans (A. xylosoxydans)]. In contrast, the effectiveness of CHG was weak compared with PVP-I, BAC and AEG. Strong resistance against AEG was noted even after 3-min exposure in 1 isolate each of A. faecalis and A. xylosoxydans. It is concluded that the turbidity test is a simple and accurate method to evaluate susceptibility to various antiseptics and that it is suitable for a screening of a large number of strains. Among the 4 antiseptics tested, PVP-I and BAC showed a consistently high activity against all isolates, confirming PVP-I and BAC to be clinically useful antiseptics.
Shimizu
M
M
Pharmaceutical Research Center, Meiji Seika Kaisha Ltd., Yokohama, Japan. masaki_shimizu@meiji.co.jp
Okuzumi
K
K
Yoneyama
A
A
Kunisada
T
T
Araake
M
M
Ogawa
H
H
Kimura
S
S
D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001548:Benzalkonium Compounds / Q000494:pharmacology; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015169:Colony Count, Microbial; D003428:Cross Infection / Q000382:microbiology*; D004352:Drug Resistance, Microbial; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D011206:Povidone-Iodine / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012706:Serratia marcescens / Q000187:drug effects; D013997:Time Factors
D000891:Anti-Infective Agents, Local; D001548:Benzalkonium Compounds; D011206:Povidone-Iodine; C010882:chlorhexidine gluconate; D002710:Chlorhexidine