zithromax and Brucellosis

Brucellosis is an important public health problem in Peru. We evaluated 48 human Brucella melitensis biotype 1 strains from Peru between 2000 and 2006. MICs of isolates to doxycycline, azithromycin, gentamicin, rifampin, ciprofloxacin, and trimethoprim-sulfamethoxazole were determined by the Etest method. All isolates were sensitive to tested drugs during the periods of testing. Relapses did not appear to be related to drug resistance.

Topics: Anti-Infective Agents; Azithromycin; Brucella melitensis; Brucellosis; Ciprofloxacin; Doxycycline; Gentamicins; Humans; Microbial Sensitivity Tests; Peru; Rifampin; Trimethoprim, Sulfamethoxazole Drug Combination

The prophylactic potential of the azalide azithromycin as well as the fluoroquinolones trovafloxacin and grepafloxacin was assessed for the control of infection with Brucella melitensis in an experimental mouse model, determined by reduction in splenic bacterial burden. Trovafloxacin showed limited protective efficacy when administered 2h following a low-dose B. melitensis challenge, whereas grepafloxacin was ineffective. In comparison, azithromycin provided significant control of infection both following low- and high-dose challenges. Overall, the data confirm the potential utility of azithromycin in the prophylaxis of brucellosis and suggest that neither trovafloxacin nor grepafloxacin would likely be valuable for post-exposure prophylaxis of Brucella infection.

Topics: Animals; Anti-Bacterial Agents; Antibiotic Prophylaxis; Azithromycin; Brucella melitensis; Brucellosis; Colony Count, Microbial; Disease Models, Animal; Female; Fluoroquinolones; Humans; Mice; Mice, Inbred BALB C; Naphthyridines; Piperazines; Spleen

Ten patients with brucellosis were treated with azithromycin and gentamicin to assess the treatment's safety and efficacy. Seven patients had an excellent therapeutic response at the end of therapy; however, relapse was noted in 3. When relapse was considered in combination with an initial lack of efficacy, 5 patients (50%; 95% confidence interval, 18.7%-81.3%) did not respond to therapy; these results do not favor the use of azithromycin to treat brucellosis in humans.

Topics: Adolescent; Adult; Anti-Bacterial Agents; Azithromycin; Brucellosis; Child; Drug Therapy, Combination; Female; Gentamicins; Humans; Male; Middle Aged; Pilot Projects; Safety; Treatment Failure; Treatment Outcome

The activities of therapeutic regimens with azithromycin (AZI) and doxycycline combined with streptomycin (DOX-SM) were compared in Brucella melitensis infected mice. In a chronic model, AZI given over 10, 14 or 21 consecutive days (50 mg/kg/24 h) significantly reduced the infection (1.3-1.6 logs, day 48 post-infection). However, the effectiveness of DOX (21 days, 50 mg/kg/12 h) was higher than AZI (3.4 logs of reduction, day 48 post-infection). Besides, when DOX was administered for 45 days, it "cured" all the animals from day 78. Similar results were obtained in an acute model infection. One single dose of DOX or DOX-SM, starting one day after lethal challenge, was able to protect 83% of the mice. In contrast, only 25% of the mice treated with AZI (50-200 mg/Kg) survived the challenge. Our findings demonstrate that AZI, in contrast to DOX-SM, does not cure experimental brucellosis.

Topics: Acute Disease; Animals; Anti-Bacterial Agents; Azithromycin; Brucella melitensis; Brucellosis; Chronic Disease; Colony Count, Microbial; Doxycycline; Drug Combinations; Female; Mice; Spleen; Streptomycin

The activities of a short therapeutic regimen with azithromycin and the classic treatment doxycycline with streptomycin were compared and evaluated in mice infected with Brucella melitensis. In a chronic model, starting therapy 31 days after challenge, azithromycin (10 days, 50 mg/kg/day) significantly reduced the infection (2.9 logs, day 48 post-infection). The effectiveness of doxycycline (21 days, 50 mg/kg/12 hourly) was greater than azithromycin (4.1 logs of reduction, day 48 post-infection), and when doxycycline was administered for a period of 45 days, all the animals were bacteriologically cured from day 78. The combination with streptomycin (14 days, 10 mg/kg/day) did not improve the effect of any of the regimens. In an acute model infection, treatments with doxycycline or doxycycline-streptomycin, for a period of 3 days, starting 1 day after lethal challenge, were able to protect all the mice. In contrast, only 50% of the mice treated with azithromycin survived the challenge. In conclusion, although a short oral treatment with azithromycin was able to reduce the infection significantly, it was not able to cure the animals as effectively as the classic regimen with doxycycline administered for a longer period of time.

Topics: Acute Disease; Animals; Anti-Bacterial Agents; Azithromycin; Brucella abortus; Brucella melitensis; Brucellosis; Chronic Disease; Doxycycline; Drug Therapy, Combination; Female; Mice; Mice, Inbred BALB C; Organ Size; Spleen; Streptomycin