The antibiotic resistance pattern of conjunctival bacteria: A key for designing a cataract surgery prophylaxis

Abstract

Purpose: To assess the prevalence of the antibiotics resistant conjunctival bacteria in order to adapt our cataract surgery prophylaxis to the new prophylaxis techniques.MethodsObservational prospective study of preoperative conjunctival cultures of consecutive patients undergoing cataract surgery during a year. Patients having eye surgical prophylaxis in the previous 6 months were excluded. The aerobiosis and microaerobiosis incubation lasted 2 and 7 days, respectively. Three profiles of identification and antibiotics sensibility tests were used. The data recorded on the Autoscan4 were exported to a Microsoft Access database. Statistical calculations were carried out with the Epidat program, 3.1 version.ResultsOf 4391 microbes isolated, 94.2% bacteria were Gram-positive and 5.3% Gram-negative. In the 1940 selected patients, their prevalence was coagulase-negative Staphylococci (CNS) 88.3%, Diphtheroids 58.1%, Propionibacteria 31%, Streptococci 23.1%, Staphylococcus aureus 10.2%, Haemophilus plus Gram-negative diplococci 7.5%, other Gram-negative rods 4.5%, Enterococci 2%. The Enterococci-Staphylococci profile was the most resistant (erythromycin 47.4%, methicillin 42.8%, ciprofloxacin 23.1%, tetracycline 18.4%, gentamicin 15.7%, levofloxacin 15.1%, tobramycin 14.8%, , chloramphenicol 3.7%, rifampicin 1.6%, and fusidic-acid 0.6%). The typical respiratory bacteria remained sensitive to chloramphenicol and Β-lactams. Other Gram-negative rods were sensitive to aminoglucosides, quinolones, and certain Β-lactams.ConclusionsNone of the antibiotics tested here, including cefuroxime and levofloxacin, was active against the whole isolated conjunctival bacteria of our patients. On the basis of our resistance patterns and other prophylaxes effects, two phases of local prophylaxis are suggested: first, eliminating Staphylococci and respiratory bacteria with rifampicin or chloramphenicol, preoperatively; second, giving levofloxacin from 1 h before surgery until 6 days afterwards. © 2009 Macmillan Publishers Limited All rights reserved.