Changing bacterial isolates and antibiotic sensitivities of purulent dacryocystitis

Purpose: 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. Sixteen 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, Escherichia coli, and Enterococcus (70%). Uncommon Gram-negative bacteria were also cultured: Alcaligenes in 2 cases (5%) and one case of Stenotrophomonas maltophilia (2.5%). No anaerobic bacteria were isolated. Gram-negative isolates were sensitive to ceftazidime in 95%, ciprofloxacin in 86% and cefuroxime in 50%, with a sensitivity of less than 30% to cefalexin and ampicillin in those tested. All Pseudomonas isolates (100%) were sensitive to ceftazidime, 86% were sensitive to ciprofloxacin, while only 20% were sensitive to ampicillin and 14% to cefalexin. Alcaligenes was resistant to all antibiotics tested with the exception of ceftazidime. 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.