TY - JOUR
T1 - Identification and expression of nor efflux family genes in Staphylococcus epidermidis that act against gatifloxacin
AU - Juárez-Verdayes, Marco A.
AU - Parra-Ortega, Berenice
AU - Hernández-Rodríguez, César
AU - Betanzos-Cabrera, Gabriel
AU - Rodríguez-Martínez, Sandra
AU - Cancino-Diaz, Mario E.
AU - Cancino-Diaz, Juan C.
N1 - Funding Information:
We thank Helen Belefant-Miller from the USDA/ARS for her advice on and assistance with this paper. This work was supported by “ Consejo Nacional de Ciencia y Tecnología ” (CONACYT) grants 153268 . Marco A. Juárez-Verdayes received doctoral scholarships from “CONACYT” and PIFI-IPN. CHR, SRM, MECD and JCCD are fellows from COFAA-IPN, EDI-IPN and SNI-CONACYT. GBC is a fellow of SNI-CONACYT.
PY - 2012/6
Y1 - 2012/6
N2 - NorA, NorB, and NorC are efflux proteins in the Nor family that regulate the secretion of fluoroquinolones, and MgrA/NorR is a transcription factor of the Nor family. Overexpression of Nor family proteins provides fluoroquinolone resistance in Staphylococcus aureus. However, in coagulase-negative staphylococci (CNS), members of the Nor family had not been identified. In this work, the presence of Nor family proteins in Staphylococcus spp. and the expression of Nor family in gatifloxacin resistant S. epidermidis strains obtained from ocular infections (OI) were identified and analyzed. S. epidermidis strains from OIs (n = 44) and healthy skin (HS; n = 52) were isolated. The nor family genes were identified in CNS using PCR, sequencing and phylogenetic approaches. Nor family expression was determined by RT-PCR. NorA efflux activity was determined using the automated ethidium bromide method. In-silico analysis showed that norA, mgrA/norR, and "norB-like" and "norC-like" (norB/norC) genes are present in CNS. The nor family genes were distributed and constitutively expressed in all S. epidermidis strains studied. In one gatifloxacin resistant strain isolated from the endophthalmitis, treatment with gatifloxacin induced overexpression of the norA gene and resulted in high activity of NorA efflux. These results indicate that the Nor family of proteins is present in CNS, and the NorA efflux mechanism for gatifloxacin response occurs in at least one strain of S. epidermidis, contributing to gatifloxacin resistance.
AB - NorA, NorB, and NorC are efflux proteins in the Nor family that regulate the secretion of fluoroquinolones, and MgrA/NorR is a transcription factor of the Nor family. Overexpression of Nor family proteins provides fluoroquinolone resistance in Staphylococcus aureus. However, in coagulase-negative staphylococci (CNS), members of the Nor family had not been identified. In this work, the presence of Nor family proteins in Staphylococcus spp. and the expression of Nor family in gatifloxacin resistant S. epidermidis strains obtained from ocular infections (OI) were identified and analyzed. S. epidermidis strains from OIs (n = 44) and healthy skin (HS; n = 52) were isolated. The nor family genes were identified in CNS using PCR, sequencing and phylogenetic approaches. Nor family expression was determined by RT-PCR. NorA efflux activity was determined using the automated ethidium bromide method. In-silico analysis showed that norA, mgrA/norR, and "norB-like" and "norC-like" (norB/norC) genes are present in CNS. The nor family genes were distributed and constitutively expressed in all S. epidermidis strains studied. In one gatifloxacin resistant strain isolated from the endophthalmitis, treatment with gatifloxacin induced overexpression of the norA gene and resulted in high activity of NorA efflux. These results indicate that the Nor family of proteins is present in CNS, and the NorA efflux mechanism for gatifloxacin response occurs in at least one strain of S. epidermidis, contributing to gatifloxacin resistance.
KW - Eye
KW - Gatifloxacin
KW - NorA
KW - NorB
KW - Staphylococcus epidermidis
UR - http://www.scopus.com/inward/record.url?scp=84860324782&partnerID=8YFLogxK
U2 - 10.1016/j.micpath.2012.03.001
DO - 10.1016/j.micpath.2012.03.001
M3 - Artículo
C2 - 22426170
SN - 0882-4010
VL - 52
SP - 318
EP - 325
JO - Microbial Pathogenesis
JF - Microbial Pathogenesis
IS - 6
ER -