Susceptibilities of Mycobacterium marinum to Gatifloxacin, Gemifloxacin, Levofloxacin, Linezolid, Moxifloxacin, Telithromycin, and Quinupristin-Dalfopristin (Synercid) Compared to Its Susceptibilities to Reference Macrolides and Quinolones

Abstract

The susceptibility pattern of Mycobacterium marinum was determined. Quinupristin-dalfopristin and telithromycin were less active than clarithromycin. Linezolid showed good antimicrobial activity at clinically achievable concentrations. Gatifloxacin, levofloxacin, and moxifloxacin displayed activities similar to those of ciprofloxacin. Gemifloxacin was less active. The Etest method showed variable agreement with the reference method.Mycobacterium marinum was recognized as a human pathogen in 1959 (13). Infection occurs when traumatized skin is exposed to contaminated water and is usually localized to the skin of the upper extremity. The organism can also cause deep-tissue infection and, rarely, disseminated disease (4, 5, 6). The incubation period has been estimated to between 2 and 4 weeks, and the infection usually resolves spontaneously after 6 to 30 months. Since infection with M. marinum is quite rare and the organism is resistant to many conventional antimicrobial agents, optimal treatment has yet to be established. The aim of this study was to determine the susceptibility of M. marinum to new antimicrobial agents. Furthermore, the Etest method was evaluated.Of the strains tested, 43 were clinical isolates collected in Sweden from 1989 to 2001. M. marinum ATCC 2275 was also included as a reference strain. Ciprofloxacin and moxifloxacin were from Bayer, Wuppertal, Germany; clarithromycin was from Abbott, Queenborough, United Kingdom; erythromycin was from Astra, Södertälje, Sweden; gatifloxacin was from Grünenthal, Stolberg, Germany; gemifloxacin was from SmithKline Beecham, Munich, Germany; linezolid was from Pharmacia & Upjohn, Kalamazoo, Mich.; and levofloxacin, quinupristin-dalfopristin, and telithromycin were from Aventis Pharma, Vitry sur Seine, France.The MICs of the drugs were determined by using MuellerHinton agar supplemented with 5% OADC (oleic acid, albumin, dextrose, and catalase) (1). A multipoint inoculator was used to deliver approximately 10 4 to 10 5 CFU per spot to agar dilution plates containing antimicrobial agents in twofold dilutions. All the plates were incubated at 30°C for 7 days. The MICs for the M. marinum strains were defined as the lowest concentration allowing no visible growth at the spot of inoculation on the agar dilution plates. The MICs for Staphylococcus aureus ATCC 21212 and Enterococcus faecalis ATCC 21213 were determined after 24 h and shown to be within reference values for all antibiotics. Etest strips were obtained from Biodisk (Solna, Sweden). The correlation of the results determined by the Etest method and the agar dilution method, used as a reference, was determined on the basis of the agreement, which was defined as the percentage of clinical isolates for which the MIC was the same within Ϯ1 log 2 dilution.The MICs of 10 antimicrobial agents determined by the agar dilution method are presented in Table 1. The MICs of clarithromycin (MIC at which 50% of the isolates tested were inhibited [MIC 50 ], 1 g/ml; MIC 90 , 1 g/ml) were lower than those for erythromycin...

Treatment of Sporotrichoid Fish Tank Granuloma with Pulsed Clarithromycin

“…From then on, several studies, based on different methods such as agar dilution, radiometric respirometric technique (Bactec) and stable gradient test (Etest), confirmed the first observations [4,5,6,7,8,9,10,11,12,13]. …”

Nontuberculous Mycobacterial Infections: A Clinical Review

“…- [89,90]; HAE: M. haemophilum [2]; a lack of consistency in susceptibility results [2]. b see [32] for further discussion; c in [89] discussed as resistant Table 4 In vitro susceptibility of selected NTM to various antimycobacterial agents.…”

In Vitro Activity of Fluoroquinolones Against Mycobacterium abscessus and Mycobacterium chelonae Causing Infectious Keratitis After LASIK in Brazil

“…Most isolates described in the literature are susceptible to amikacin or tobramycin, one of the fluoroquinolones, and to clarithromycin. 30,33,56,71,74 A combination of these drugs as the initial topical treatment of suspected cases until culture and susceptibility tests are available may be warranted.…”

“…41,[47][48][49][50][51][52] Although in vitro activity does not always accurately predict therapeutic efficacy, in vitro tests may aid in determining the best antibiotic coverage, particularly when MIC results are available. 53 Some in vitro studies have shown that amikacin, ciprofloxacin, norfloxacin, vancomycin, tobramycin, and gentamicin can be active against rapidly growing mycobacteria (RGM), [32][33][34][54][55][56] but there are few drugs that are active against M. chelonae and M. abscessus. 28,52,[57][58][59] In vitro susceptibility tests with the newer fluoroquinolones (8-methoxy fluoroquinolones), gatifloxacin and moxifloxacin, have shown that gatifloxacin is more active than ciprofloxacin against various mycobacterial species.…”