TY - JOUR
T1 - Gatifloxacin, moxifloxacin, and balofloxacin resistance due to mutations in the gyra and parc genes of staphylococcus epidermidis strains isolated from patients with endophthalmitis, corneal ulcers and conjunctivitis
AU - Betanzos-Cabrera, Gabriel
AU - Juárez-Verdayes, Marco A.
AU - González-González, Gabriel
AU - Cancino-Díaz, Mario E.
AU - Cancino-Díaz, Juan C.
PY - 2009/7
Y1 - 2009/7
N2 - Aims:Staphylococcus epidermidis 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 S. epidermidis strains isolated from ocular infections. Methods:S. epidermidis 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 gyrA and parC genes, and their expression was determined by reverse transcriptase polymerase chain reaction. Results: 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 gyrA gene, and Ser80Phe for the parC gene. Gatifloxacin did not change the expression levels of gyrA and parC genes. Conclusion:S. epidermidis strains isolated from three ocular pathologies were gatifloxacin and moxifloxacin resistant due to mutations on the gyrA and parC genes.
AB - Aims:Staphylococcus epidermidis 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 S. epidermidis strains isolated from ocular infections. Methods:S. epidermidis 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 gyrA and parC genes, and their expression was determined by reverse transcriptase polymerase chain reaction. Results: 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 gyrA gene, and Ser80Phe for the parC gene. Gatifloxacin did not change the expression levels of gyrA and parC genes. Conclusion:S. epidermidis strains isolated from three ocular pathologies were gatifloxacin and moxifloxacin resistant due to mutations on the gyrA and parC genes.
KW - Balofloxacin resistance
KW - Gatifloxacin resistance
KW - GyrA
KW - Moxifloxacin resistance
KW - ParC
KW - Staphylococcus epidermidis
UR - http://www.scopus.com/inward/record.url?scp=66149119794&partnerID=8YFLogxK
U2 - 10.1159/000219684
DO - 10.1159/000219684
M3 - Artículo
SN - 0030-3747
VL - 42
SP - 43
EP - 48
JO - Ophthalmic Research
JF - Ophthalmic Research
IS - 1
ER -