Conjunctival sac bacterial flora isolated prior to cataract surgery

Abstract

ObjectiveTo determine the trends of conjunctival sac bacterial flora isolated from patients prior to cataract surgery.Subjects and methodsThe study comprised 579 patients (579 eyes) who underwent cataract surgery. Specimens were collected by lightly rubbing the inferior palpebral conjunctival sac with a sterile cotton swab 2 weeks before surgery, and then cultured for isolation of bacteria and antimicrobial sensitivity testing. The bacterial isolates and percentage of drug-resistant isolates were compared among age groups and according to whether or not patients had diabetes mellitus, hyperlipidemia, dialysis therapy, oral steroid use, dry eye syndrome, or allergic conjunctivitis.ResultsThe bacterial isolation rate was 39.2%. There were 191 strains of Gram-positive cocci, accounting for the majority of all isolates (67.0%), among which methicillin-sensitive coagulase-negative staphylococci was the most frequent (127 strains, 44.5%), followed by methicillin-resistant coagulase-negative staphylococci (37 strains, 12.7%). All 76 Gram-positive bacillary isolates (26.7%) were from the genus Corynebacterium. Among the 16 Gram-negative bacillary isolates (5.9%), the most frequent was Escherichia coli (1.0%). The bacterial isolation rate was higher in patients >60 years old, and was lower in patients with dry eye syndrome, patients under topical treatment for other ocular disorders, and patients with hyperlipidemia. There was no significant difference in bacterial isolation rate with respect to the presence/absence of diabetes mellitus, steroid therapy, dialysis, or a history of allergic conjunctivitis. Methicillin-resistant coagulase-negative staphylococci showed a significantly higher detection rate in diabetic patients than nondiabetic patients (20.3% versus 7.0%, P < 0.05). The percentage of all isolates resistant to levofloxacin, cefmenoxime, and tobramycin was 14.0%, 15.2%, and 17.9%, respectively, with no significant differences among these drugs.ConclusionThe high bacterial isolation rate in patients >60 years old and the high methicillin-resistant coagulase-negative staphylococci isolation rate in patients with diabetes are important to consider for prevention of perioperative infections.

Conjunctival Flora in Diabetic and Nondiabetic Individuals

“…These conflicting results may be attributable to the differences in the DR rate between studies. The DR rates in the aforementioned studies were 86.77% for Karimsab and Razak, 12 74.8% for Arbab et al 13 and 8.29% for Suto et al 10 In our study, the rate of DR was 22.6%.…”

“…Arbab et al 13 observed a positive culture rate of 75% in their PDR group compared to 20% in patients without retinopathy, and Staphylococcus epidermidis was the most common isolate. In contrast, Suto et al 10 found no difference in the frequency of positive cultures between diabetic and non-diabetic patients and no relationship between positive culture frequency and the presence of diabetic retinopathy. These conflicting results may be attributable to the differences in the DR rate between studies.…”

“…In the same study, sensitivity of isolated Staphylococcus epidermidis cultures to ofloxacin and ciprofloxacin was 92.5% and 91.5%, respectively. Suto et al 10 found a higher prevalence of methicillin-resistant CNS in diabetic patients and reported that resistance rates of 14% to levofloxacin and 17.9% to tobramycin in the isolates they obtained. Gupta et al 20 found that in all gram-positive cultures isolated from endophthalmitis cases were sensitive to vancomycin and all gram-negative cultures were sensitive to ceftazidime.…”

“…8,9 Similar changes in diabetic patients have also been reported in the literature. Suto et al 10 studied 579 individuals and found a unilateral positive culture rate of 39.2% with CNS as the major bacterial flora element. In the same study, the rate of gram-negative bacteria was 5.9% and the most common gram-negative bacterium was Escherichia coli.…”

Dry Eye Disease and Microbial Keratitis: Is There a Connection?

“…254 The bacterial isolation rate was significantly lower in dry eye patients (using only artificial tears) than for those without dry eye disease, and the use of artificial tears reduced the bacterial isolation rate compared to patients not using topical medication. Patients taking oral steroids did not have a significant difference in bacterial isolation rates.…”