Comparative Evaluation of Fixed Dose Combination of Ofloxacin and
Ornidazole Against Some Aerobic Bacteria
The present study is undertaken to evaluate the antimicrobial
properties of a new Fixed Dose Combination (FDC) of Ofloxacin Ornidazole
for infusion against some aerobic bacteria in comparison with Ofloxacin
and Ornidazole individually. Antibiotic Susceptibility Test (AST) and
Minimum Inhibitory Concentration (MIC) of FDC of Ofloxacin Ornidazole,
Ofloxacin and Ornidazole for P. aeruginosa, S. aureus, E.
coli, K. pneumoniae, S. epidermis and MRSA were determined
by disc method and broth micro dilution method. In Antimicrobial Susceptibility
Test, lytic zone of combination was found to be more than Ofloxacin or
Ornidazole alone in all microbial strains under study. The MIC value of
FDC of Ofloxacin Ornidazole was found to be higher than both Ofloxacin
and Ornidazole. The data suggests that fixed dose combination of Ofloxacin
and Ornidazole can be a good option for use in mixed microbial infection
of aerobic bacteria, anaerobic bacteria and pathogenic protozoans.
In Antimicrobial Susceptibility Test, lytic zone of combination was found
to be more than Ofloxacin alone in all microbial strains under study. Lytic
Zone less than 10 mm was found in S. aureus, E. coli and P.
aeruginosa in Ornidazole whereas no other organism showed any lytic zone
development with Ornidazole (Fig. 1).
||The MIC values of fixed dose combination of Ofloxacin Ornidazole,
Ofloxacin and Ornidazole
||Lytic Zone size (mm) in Antibiotic susceptibility test of
fixed dose combination of Ofloxacin Ornidazole, Ofloxacin and Ornidazole
As the problem of antibiotic resistance is growing in mixed microbial infection, awareness of use of fixed dose combination for antibacterials has also increased. It is the present trend to evaluate interaction and efficacy of antibiotic combinations such as quinolones with other antibiotics like gentamicin to being used overcome the resistance in microorganisms (Iroha et al., 2008). This concept has most firmly taken root in the Intensive Care Unit (ICU), where empiric antibiotic regimens have been developed not only for safety and efficacy of treatment, but also to prevent the rise of resistant organisms (Kollef, 2005). The traditional antimicrobial therapy of choice in any circumstance has been a regimen that is efficacious, safe and inexpensive. However, if that regimen induces antibiotic resistance then efficacy soon suffers. Ofloxacin is a fluoroquinolone with an indication for bacterial infection. It is well documented that Ornidazole is a potent antiprotozoal and also has antibiotic property against anaerobic bacteria (Merdjan et al., 1985; Jokipii and Jokipii, 1977). There have been attempts to combine these antimicrobials into intravenous infusion for treatment of mixed microbial infection particularly gastric tact infection and diarrhea. It is also evident that pharmacokinetics of these groups of antibacterials do not interfere with each other (Michael et al., 1990).
Present study was carried out with the hypothesis that fixed dose combination of Ofloxacin and Ornidazole act synergistically in aerobic bacteria apart from having proven individual anaerobic antibacterial and antiprotozoal properties. There has been increase in MIC value of combination by 2 to 8 folds in all bacteria other than S. epidermis under study, when compared with Ofloxacin alone. In case of S. epidermis MIC of the combination was found to be similar to Ofloxacin. The MIC of the combination was significantly lower when compared with Ornidazole alone in all organisms under study. Ornidazole practically no therapeutic significant MIC value in organisms under study. In AST, Zone of Ofloxacin alone was found to be similar to FDC with non significant variation. There is statistically significant increase of lytic zone of FDC when compared with Ornidazole alone in S. aureus, E. coli and P. aeruginosa under this study. The FDC has proven efficacy against aerobic bacteria and expected to have efficacy against anaerobic bacteria and pathogenic protozoans. There are earlier reports describing antimicrobial properties of Ofloxacin (Farinotti et al., 1988; Gruenberg et al., 1988) and Ornidazole (Goldstein et al., 1978) individually. There is no earlier work done on antimicrobial efficacy of there drugs in combination, although there has been published reports of toxicological studies of this FDC (Chaudhary et al., 2009).
In the present study, antimicrobial properties of FDC of Ofloxacin Ornidazole infusion is evaluated in some aerobic bacteria in comparison with Ofloxacin and Ornidazole individually. Minimum inhibitory concentration and AST results suggests that the FDC is more effective than Ofloxacin or Ornidazole alone in all organisms under study. It is already established that Ornidazole has got activity against anaerobic bacteria and pathogenic protozoans. It may be concluded that fixed dose combination of Ofloxacin and Ornidazole can have be a good potential for use in mixed microbial infection of aerobic bacteria, anaerobic bacteria and pathogenic protozoans.
Authors are thankful CGM, Domestic operations of Venus Remedies Limited for providing the samples of FDC of Ofloxacin Ornidazole, Ofloxacin and Ornidazole for this study." class="btn btn-success" target="_blank">View Fulltext