Antibacterial Activity of Azithromycin against <i>Brucella melitensis</i>

Abstract

In vitro antibacterial activity of the new macrolide azithromycin was tested against 116 strains of Brucella melitensis, isolated from 115 patients in a major tertiary care referral center. Eighty-seven percent of the strains were inhibited by 1.0 mg/l and all the 116 strains by 2.0 mg/l of azithromycin. Comparison was made with tetracycline, gentamicin, trimethoprim-sulfamethoxazole, rifampicin and ciprofloxacin. All the isolates were susceptible to gentamicin, tetracycline, trimethoprim-sulfamethoxazole, rifampicin. One hundred and fifteen of the 115 strains were also susceptible to ciprofloxacin.

In vitro Activities of Various Antimicrobials against <i>Brucella melitensis</i> Strains in the Aegean Region in Turkey

“…However, the MIC values of the isolates in this study were higher compared to those previously reported [15][16][17] . Of the four macrolides tested in this study, dirithromycin was the least active agent (64 g/ml), thereby supporting our previous in vivo fi ndings in a murine brucellosis model, in which dirithromycin had the lowest cure rate alone or in combination with rifampicin [18] .…”

In vitro-selected resistance to fluoroquinolones in two Brucella strains associated with mutational changes in gyrA

“…However, results of experimental and clinical studies that focused on quinolone activity against Brucella are controversial and conflicting [6,[8][9][10][11][12][13]]. An appreciable rate of relapse along with therapeutic failures in patients treated with ciprofloxacin has been reported [13,14], whilst past studies have documented that the use of ciprofloxacin can be followed by development of resistance, with cross-resistance emerging to most other members of the family [13][14][15][16][17][18][19].…”

In Vitro Activities of Antibiotics Alone and in Combination against Brucella melitensis at Neutral and Acidic pHs

“…Consequently, new treatments are sought. Fluoroquinolones and newer macrolides have good anti-Brucella activity in vitro (1,9,12) and reach high intracellular concentrations, but their in vitro activity may predict efficacy poorly, since brucellae survive in compartments that are inaccessible or hostile to antimicrobial activity. These include the phagolysosomes of macrophages, where the pH may be as low as 5.0 (8).…”