In Vitro Comparison of Antibacterial and Antibiofilm Activities of Selected Fluoroquinolones against Pseudomonas aeruginosa and Methicillin-Resistant Staphylococcus aureus.

Majed M Masadeh,Aisha S Magaji,Wesam S Ahmed,Karem H Alzoubi

doi:10.3390/pathogens8010012

Abstract

An in vitro overview of the inhibitory effects of selected fluoroquinolones against planktonic and biofilm cells of the methicillin-resistant Staphylococcus aureus (MRSA) strain American type culture collection (ATCC) 43300 and the Pseudomonas aeruginosa strain ATCC 27853 was carried out. Biofilm cells of both strains were less susceptible to the selected antibiotics than their planktonic counterparts. In addition, certain antibiotics were more effective against biofilm cells, while others performed better on the planktonic cells. Against P. aeruginosa, ciprofloxacin was the most potent on both planktonic and biofilm cells, whereas ofloxacin was the least potent on both biofilm and planktonic cells. Moxifloxacin and gatifloxacin were the most potent against both planktonic and biofilm MRSA bacteria, however, not in the same order of activity. Norfloxacin was the least active when tested against both planktonic and biofilm cells. The results of this work are expected to provide insight into the efficacy of various fluoroquinolones against MRSA and Pseudomonas aeruginosa biofilms. This study could form the basis for future clinical studies that could recommend special guidelines for the management of infections that are likely to involve bacteria in their biofilm state.

Highlights

A biofilm represents a structured, organized, and complex group of sessile bacterial cells attached to a surface, which grow and interact as a community [1]
The agar-well diffusion method was used to determine the zones of inhibition (ZOIs) of the selected FLQs against Methicillin-resistant Staphylococcus aureus (MRSA) and P. aeruginosa planktonic cells
The data obtained from the current study revealed that all the selected FLQs showed considerable growth inhibitory zones, the susceptibility of P. aeruginosa to these antibiotics varied from high to moderate

Summary

Introduction

A biofilm represents a structured, organized, and complex group of sessile bacterial cells attached to a surface, which grow and interact as a community [1]. Biofilms are characterized by significant loss of susceptibility to antibiotics as well as high virulence potential [3], which explains why biofilms are associated with a tremendous impact on health, including increased morbidity and mortality [4]. Complications related to biofilms often result in additional hospitalization and medical care for patients, leading to substantial economic consequences [5]. Staphylococcus aureus and Pseudomonas aeruginosa are medically significant microbes that are capable of forming biofilms [3]. Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of hospital-acquired infections that are becoming more difficult to combat because of the development of bacterial resistance to most of the current antibiotics [6].

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Results

Conclusion