antibiotic
fluoroquinolone
YH,YL
Fluoroquinolone antibiotics have greater activity in vitro against Brucella species than the parent drug nalidixic acid. In addition, they are well absorbed after oral administration, and they achieve high concentrations within phagocytic cells. Although the minimum bactericidal concentration of quinolones is reported to be approximately four times the minimum inhibitory concentration, a lack of bactericidal activity was found at pH levels comparable to those found within cells. In addition, when quinolones were used as monotherapy in experimental animals and humans infected with Brucella, the rates of relapse were unacceptably high. Therefore, quinolones should always be used in combination with other drugs, such as doxycycline or rifampicin.
(http://www.who.int/csr/resources/publications/Brucellosis.pdf p38)