Changing bacterial isolates and antibiotic sensitivities of purulent dacryocystitis

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

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.

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 (7%). 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.

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.