In-vitro comparison of tigecycline as an alternative to the classical therapy in brucellosis treatment

Abstract

Brucellosis is an important zoonosis because of its difficult and prolonged treatment regimen; at the same time, it sometimes involves serious complications. The aim of the study was to determine the antibiotic susceptibility profiles of ciprofloxacin, clarithromycin, doxycycline, rifampicin, streptomycin, and tigecycline using the E-test method on brucellosis, and the distribution of Brucella species. Forty-four patients (24 men, 20 women) who were admitted to our laboratory between 2014 and 2016 and for whom Brucella bacteria were found to be grown in their blood cultures were included in the study. Blood samples from patients were incubated on BD Bactec Fx. Positive signaling samples were plated on sheep blood agar and eosin methylene blue agar media. The bacteria were then allowed to grow for 48 h in an incubator at 37 degrees C. Gram-negative cocobacillus as a result of Gram staining was identified with the Vitek 2 Compact instrument and the gram negative identification kit. Antibiotic susceptibility tests against ciprofloxacin, clarithromycin, doxycycline, rifampicin, streptomycin, and tigecycline were also evaluated. Twenty four (54.5%) of 44 patients were men, 20 (45.5%) were women and the mean age was 42.5. The youngest patient was 14 and the oldest patient was 86 years old. All of the isolated bacteria (100%) were detected as Brucella melitensis with the fully automated culture antibiogram device (Vitek 2 Compact, Biomerieux). In the evaluation realized by E-test method, the minimum and maximum minimum inhibitory concentration values for each antibiotic taken for study were obtained as follows: for ciprofloxacin, 0.125-0.50 mu g/ml; for clarithromycin, 0.32-1 mu g/ml; for doxycycline, 0.032-0.64 mu g/ml; for rifampicin, 0.016-0.32 mu g/ml; for streptomycin, 0.10-0.25 mu g/ml; and for tigecycline, 0.125-0.38 mu g/ml. B. melitensis was detected as the causative factor in the majority of cases of brucellosis in the world. Furthermore, according to the E-test method, lower minimum inhibitory concentration values for doxycycline, rifampicin, streptomycin, and tigecycline indicate that they are important antimicrobials in the treatment.