Fluoroquinolone Therapy in Staphylococcus aureus Infections: Where Do We Stand?

Abstract

Aim:The study aimed to evaluate the utility of various commonly used fluoroquinolones against Staphylococcus aureus isolates.Materials and Methods:A total of 250 isolates of S. aureus were studied from different clinical specimens like blood, pus, wound swabs, sputum, ear swabs, and body fluids between November 2009 and December 2011. All the isolates were tested for their susceptibility to fluoroquinolones and other antimicrobial agents by Kirby-Bauer disc diffusion method using criteria of standard zone of inhibition. Methicillin-resistant S. aureus (MRSA) detection was done by cefoxitin disk diffusion method. The MRSA isolates were tested for minimum inhibitory concentration (MIC) to vancomycin by E-test strips. All the MRSA strains were sent to National Staphylococcal Phage-typing Centre, Maulana Azad Medical College, New Delhi for phage typing.Results:A total of 107 strains of S. aureus (42.8%) were detected as MRSA. Multidrug resistance was observed among the MRSA strains more commonly than among the MSSA stains. Among the fluoroquinolones, maximum resistance in MRSA was seen to ciprofloxacin (92.5%), followed by ofloxacin (80.4%). None of the S. aureus isolates showed resistance to vancomycin and linezolid. The MICs of vancomycin for the MRSA tested ranged from 0.5 to 2 μg/ml. Phage typing pattern of 107 MRSA isolates revealed that 37 (34.6%) MRSA isolates were nontypeable and 70 (65.4%) were typeable.Conclusion:Ciprofloxacin can no longer be used in empirical therapy against MRSA infections. Use of other members of fluoroquinolone should be limited only to those strains that show laboratory confirmation of their susceptibility. Vancomycin remains the drug of choice to treat MRSA infections.

Staphylococcus Aureus Infections and Their Antibiotic Susceptibility Profile at a Tertiary Care Hospital

“…We did not find a significant difference in infection profile between MRSA and MSSA isolates, mirroring the finding of Dilnessa and Bitew [21]. MRSA strains were found to be more resistant to non-beta lactam antibiotics compared to MSSA (Table 2), similar to findings of earlier studies [5,11,12]. Infection control practices need to be further strengthened and complemented with judicious antimicrobial prescribing to reduce the burden of MRSA infections.…”

“…Bouchiat et al, in their analysis of 92 S. aureus clinical isolates, found 70.6% (n=65) of them to be resistant to ciprofloxacin [11]. Gade and Qazi have reported 57.6% (n=144) isolates of S. aureus to be ciprofloxacin resistant [12]. High rates of quinolone resistance have also been noted earlier by Metri et al among S. aureus isolates (n=137) [13].…”

Phenotypic and Genotypic Determination of Antibiotic Resistances of Some Clinical Staphylococcus aureus Isolates

“…On iki Avrupa ülkesinden 78 laboratuvarla işbirliği içinde yürütülen bir çalışma, florokinolonlara direnç prevalansında büyük farklılıklar ortaya çıkarmıştır ve en yüksek direnç oranları %70.6 olarak MR-SA'larda kaydedilmiştir [28] . Klinik örneklerden Kirby-Bauer disk difüzyon yöntemi ile florokinolon direncini araştıran bir çalışmada MRSA izolatlarında siprofloksasin direnci %92.5 olarak bildirilmiştir [29] .…”

Biofilm formation and Antibiotic susceptibility pattern among Staphylococcus aureus in a tertiary care hospital in Kanchipuram: An Evaluation of screening methods for biofilm formation

“…Studies have reported resistance to ciprofloxacin among MRSA ranging from 39% to 68%. (20) In a study by Neeta D Gade et al, (2013) ciprofloxacin resistant MRSA was 6.5%. (20) Agarwal et al, (2013) have reported 53.7% of the biofilm producing MRSA isolates as Ciprofloxacin resistant MRSA.…”

“…(20) In a study by Neeta D Gade et al, (2013) ciprofloxacin resistant MRSA was 6.5%. (20) Agarwal et al, (2013) have reported 53.7% of the biofilm producing MRSA isolates as Ciprofloxacin resistant MRSA. (4) Biofilm producing bacterial isolates are recalcitrant to antibiotic therapy leading to chronic infection.…”