Low endotoxin release from Escherichia coli and Bacteroides fragilis during exposure to moxifloxacin.

BACKGROUND

Bacterial endotoxin is known to act as a potent trigger of disseminated coagulation and septic shock. During clinical antibiotic treatment, endotoxin may be released from Gram-negative bacteria. It is known that antibiotic classes differ in their ability to induce endotoxin release.

AIM

It was the aim of this study to test the endotoxin-liberating potential of different antibiotics with activity against Escherichia coli and Bacteroides fragilis.

METHODS

In vitro test models were used to evaluate the endotoxin-liberating potential of moxifloxacin, a 4th-generation quinolone with antianaerobic activity. Bacteria were exposed to moxifloxacin at 2×, 10× and 50× the minimal inhibitory concentration. Endotoxin release was measured by enzyme-linked immunosorbent and Limulus amoebocyte lysate assays. Comparator drugs were ceftazidime and imipenem, i.e. antibiotics with known high and low endotoxin-liberating potential, respectively. As a parameter for biological responses to endotoxin, the release of proinflammatory cytokines (tumor necrosis factor-α, interleukin-1β) from monocytes/macrophages was quantified with bioassays.

RESULTS

In all test systems, release of endotoxin during exposure of bacteria to moxifloxacin was minimal or low and comparable with that of imipenem.

CONCLUSIONS

Moxifloxacin has a low potential to cause endotoxin-mediated detrimental clinical effects. Concerning its endotoxin-releasing properties, moxifloxacin appears to be a choice equivalent to the carbapenems.