In:
Ophthalmic Research, S. Karger AG, Vol. 42, No. 1 ( 2009), p. 43-48
Abstract:
〈 i 〉 Aims: 〈 /i 〉 〈 i 〉 Staphylococcus epidermidis 〈 /i 〉 is considered a commensal bacterium; however, it is frequently isolated from ocular infections showing a multidrug resistance. Ciprofloxacin-resistant strains have been isolated from ocular infections; however, resistance to quinolone, such as gatifloxacin and moxifloxacin, is not often studied, consequently the resistance mechanism is unknown. Our aim was to address the quinolone resistance and to explore the resistance mechanism in 〈 i 〉 S. epidermidis 〈 /i 〉 strains isolated from ocular infections. 〈 i 〉 Methods: 〈 /i 〉 〈 i 〉 S. epidermidis 〈 /i 〉 strains were isolated from patients with conjunctivitis (n = 23), endophthalmitis (n = 14) and corneal ulcers (n = 7). Minimum inhibition concentrations were determined by broth and agar dilution methods for moxifloxacin, gatifloxacin, balofloxacin, rufloxacin and pazufloxacin. Mutations were identified by sequencing the 〈 i 〉 gyrA 〈 /i 〉 and 〈 i 〉 parC 〈 /i 〉 genes, and their expression was determined by reverse transcriptase polymerase chain reaction. 〈 i 〉 Results: 〈 /i 〉 We found that 13.6% (6/44) of the strains were quinolone resistant. In endophthalmitis, 21.4% were gatifloxacin, moxifloxacin and balofloxacin resistant. In corneal ulcers, 14.2, 14.2 and 28.5% were gatifloxacin, moxifloxacin and balofloxacin resistant, respectively, and in conjunctivitis only 4.3% were gatifloxacin resistant. The 6 strains with quinolone resistance showed mutations at Ser84Phe for the 〈 i 〉 gyrA 〈 /i 〉 gene, and Ser80Phe for the 〈 i 〉 parC 〈 /i 〉 gene. Gatifloxacin did not change the expression levels of 〈 i 〉 gyrA 〈 /i 〉 and 〈 i 〉 parC 〈 /i 〉 genes. 〈 i 〉 Conclusion: 〈 /i 〉 〈 i 〉 S. epidermidis 〈 /i 〉 strains isolated from three ocular pathologies were gatifloxacin and moxifloxacin resistant due to mutations on the 〈 i 〉 gyrA 〈 /i 〉 and 〈 i 〉 parC 〈 /i 〉 genes.
Type of Medium:
Online Resource
ISSN:
0030-3747
,
1423-0259
Language:
English
Publisher:
S. Karger AG
Publication Date:
2009
detail.hit.zdb_id:
1483177-6
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