Changing bacterial isolates and antibiotic sensitivities of purulent dacryocystitis

Abstract

Objective: To examine the current spectrum of bacterial isolates in cases of chronic dacryocystitis and dacryoabcess and to determine their antibiotic sensitivities.

Materials and methods: We carried out a prospective study in which 39 patients who presented to the outpatient clinic with chronic purulent dacryocystitis or acute dacryoabscess had cultures taken. All patients were antibiotic-free for at least one week prior to culturing.

Results: The 39 positive cultures grew 41 bacterial isolates, as two patients grew two species of bacteria; 16 isolates (39%) were Gram-positive and 25 (61%) were Gram-negative. The most common isolates were Pseudomonas (22%), Staphylococcus aureus (13%), Enterobacter (10%), Citrobacter (10%), Streptococcus pneumoniae, E. coli, and Enterococcus (7%). Uncommon Gram-negative bacteria were also cultured: Alcaligenes in two cases (5%), and one case of Stenotrophomonas maltophilia (2.5%). No anaerobic bacteria were isolated. Gram-negative isolates were sensitive to ceftazidime in 95%, ciproxin in 86%, and cefuroxime in 50% of cases, with sensitivity of less than 30% to cephalexin and ampicillin in those tested. All Pseudomonas isolates (100%) were sensitive to ceftazidine, 86% were sensitive to ciprofloxacin, with only 20% being sensitive to ampicillin and 14% to cephalexin. Alcaligenes was resistant to all antibiotics tested with the exception of ceftazidine.

Conclusion: This study demonstrates a significant change in bacterial flora and antibiotic treatment requirements of purulent dacryocystitis from previously published data. A higher incidence of Gram-negative organisms, particularly Pseudomonas, with resistance to commonly used antibiotics was found. The emergence of rarer highly resistant Gram-negative microorganisms may also indicate a trend in lacrimal sac infections. These findings suggest that the antibiotic treatment protocol before and after lacrimal surgery should be reconsidered in this subgroup of patients.