Ciprofloxacin's Antibacterial Effect on Sensitive and Resistant Isolates of Enterococcus faecalis
Noor Flayyih Hasan *
Department of Microbiology, College of Medicine, Kerbela University, 56001, Iraq.
Huda A Najy
Department Medical Laboratory Techniques, University of Ahl al-Bayt, College of Medical and Health Technology, Iraq.
Firas.A. ali
Department Medical Laboratory Techniques, University of Ahl al-Bayt, College of Medical and Health Technology, Iraq.
*Author to whom correspondence should be addressed.
Abstract
An investigation was carried out to research the antibacterial properties of ciprofloxacin against susceptible and resistant isolates of Enterococcus faecalis and studying susceptible individuals are exposed to sub-MIC in vitro, resistance this purpose. After determining the inhibitory zone and ciprofloxacin MIC, the sensitive isolates were subjected to sub-MIC continuously for 21 days. The findings demonstrated the minimum inhibitory concentrations (MICs) for susceptible and resistant Enterococcus faecalis were, respectively, 0.26±0.07 and 29.82±9.33 μg/ml. In concern to susceptible E. faecalis, the inhibition zones were (15.50 ± 0.30, 21.00 ± 0.50 and 23.50 ± 0.70 mm) with significant difference (P<0.05) save for the range of 0.5 to 1MIC, whereas those of the resistant E. faecalis were 9.80 ± 0.40, 13.00 ± 0.30 and 18.50 ± 0.60 mm. with substantial distinction (P< 0.05) all concentrations. When comparing the absorbance to those from day zero, the spectrophotometer's measurements of the bacterial density at various intervals ranging from 0 to 21 days revealed a substantial steady increase (P<0.05). Finally, after 21 days of exposure to sub-MIC, ciprofloxacin resistance developed in susceptible Enterococcus faecalis.
Keywords: Enterococcus faecalis, ciprofloxacin, resistance, antimicrobials