Ciprofloxacin therapy for methicillin-resistant Staphylococcus aureus infections or colonizations

Abstract

Thirty patients were treated for colonization or for skin and soft tissue infections caused by methicilinresistant Staphylococcus aureus. Three treatment regimens were evaluated, each progressively more aggressive. One regimen was 750 mg of ciprofloxacin twice daily for 5 days, the second regimen was 750 mg of ciprofloxacin twice daily for 10 to 14 days, and the final regimen was 750 mg of ciprofloxacin twice daily plus 300 mg of rifampin twice daily for 21 days. It appears that ciprofloxacin alone produced an initial eradication rate in at least one site in 50% of the patients, regardless of whether the treatment was for 5 or up to 14 days. All of the patients with eradication became recolonized within 1 week posttherapy. When rifampin was combined with ciprofloxacin, the eradication rate was 100% when the isolates were susceptible to both agents, and these patients remained free of methicillin-resistant S. aureus at 1-week and 1-month follow-ups.Methicillin-resistant Staphylococcus aureus (MRSA) has recently emerged as both a colonizing organism and a pathogen among many hospitalized patients. The therapy of infections caused by this organism or the eradication of colonization is particularly difficult. None of the beta-lactam antibiotics appears to be clinically effective; chloramphenicol has not proven effective for the treatment of staphylococcal infection in the past; erythromycin therapy produced rapid emergence of resistance and treatment failures; and finally, the use of aminoglycosides has resulted in the rapid emergence of resistant small-colony variants. Bacitracin, although active against this organism, cannot be applied to the upper nares comfortably to enable eradication of the carrier state. Although vancomcyin has proven effective for treating staphylococcal infections in many body sites, this therapy is expensive. Furthermore, vancomcyin is ineffective for those body sites in which vancomycin does not penetrate well, such as the nares.With the availability of the newer quinolone compounds, many of which show adequate to good in vitro activity against both methicillin-susceptible and methicillin-resistant staphylococci (9, 10), enthusiasm for use of the quinolones for treatment of infection or colonization by MRSA seems justified. We therefore evaluated the effectiveness of ciprofloxacin for treatment of skin and soft tissue infections and for eradication of MRSA carriage. MATERIALS AND METHODSPatient population. Patients identified by the primary care physicians or infection control staff as infected or colonized with MRSA as the primary or sole pathogen were evaluated for entrance into the study. All patients were interviewed and clinically reevaluated by the principal investigator (R.H.K.E.) and informed consent was obtained prior to enrollment. Cultures of the skin structures were obtained by aspiration from the leading edge of the infection. Cultures of groin and perirectal areas were obtained by using salinesoaked cotton-tipped swabs over an area of at least 10 cm2. Cultures of the nares w...

Ciprofloxacin-resistant methicillin-resistant Staphylococcus aureus in New York health care facilities, 1988. The New York MRSA Study Group.

“…'7-'9 Ciprofloxacin susceptibility has been tested since May 1987 and resistance to ciprofloxacin was defined as a minimal inhibitory concentration . 4 25 were females, and the age range was 23 to 96 years, with a mean of 67.5 years and a median of 73 years. The mean age of the nursing home patients (71.8 years) was five years greater than that of the hospital patients.…”

Methicillin-resistant staphylococci: detection methods and treatment of infections

“…In another study comparing ciprofloxacin alone to ciprofloxacin in combination with rifampin, resistance to ciprofloxacin emerged during treatment in two patients (79). One of the two patients was receiving the combination, but because the pretreatment clinical isolate was rifampin resistant, ciprofloxacin was the only active drug in the regimen.…”

Association with prior fluoroquinolone therapy of widespread ciprofloxacin resistance among gram-negative isolates in a Veterans Affairs medical center

“…High-level ciprofloxacin resistance among methicillin-resistant Staphylococcus aureus strains has been reported following the use of ciprofloxacin for eradication of staphylococcal colonization (14). Resistant isolates of Pseudomonas aeruginosa and members of the family Enterobacteriaceae can be selected in vitro (3,15) and may occur in vivo after ciprofloxacin therapy (10,13).…”