Modulation of the norfloxacin resistance in Staphylococcus aureus by Croton campestris A. and Ocimum gratissimum L.
BACKGROUND
Some species of Staphylococcus are often recognized as etiological agents of many animal and human opportunistic infections. This study is the first test of change in resistance of antibiotic activity by Croton campestris A. and Ocimum gratissimum L. against multiresistant strains of Staphylococcus aureus.


OBJECTIVE
In this study, the hexane and methanol extract of Croton campestris A. and Ocimum gratissimum L. was tested for antibacterial activity alone and in combination with norfloxacin against the strain SA1199B.


METHODS
The minimum inhibitory concentration (MIC) and the modulatory effect of extracts was assayed using microtitre assay.


RESULTS
By the fact of the MIC observed was not clinically relevant (MIC= 512 to ≥1.024 µg/ml), the antibiotic activity of norfloxacin was enhanced when this antibiotic was combined with sub-inhibitory concentrations of extracts, mainly the hexane extracts.


CONCLUSIONS
These results indicate that the assayed extracts present compounds that can be used as a putative efflux pump inhibitor, indicating that Croton campestris A. and Ocimum gratissimum L. can be a source of plant derived products with antibiotic modifier activity.
Laboratório de Microbiologia e Biologia Molecular, Universidade Regional do Cariri, Crato, CE, Brasil. hdmcoutinho@gmail.com
Henrique D M
HD
Coutinho
Edinardo F F
EF
Matias
Karla K A
KK
Santos
Francisco A V
FA
Santos
Maria Flaviana B
MF
Morais-Braga
Teógenes M
TM
Souza
Jacqueline Cosmo
JC
Andrade
Celestina E S
CE
Souza
Saulo R
SR
Tintino
Gláucia M M
GM
Guedes
Vivyanne S
VS
Falcão-Silva
José P
JP
Siqueira-Júnior
José G M
JG
Costa
D029802:Croton; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D004357:Drug Synergism; D006586:Hexanes / Q000494:pharmacology*; D006801:Humans; D000432:Methanol / Q000494:pharmacology*; D009643:Norfloxacin / Q000494:pharmacology*; D031339:Ocimum; D010936:Plant Extracts / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects*
D006586:Hexanes; D010936:Plant Extracts; C026385:n-hexane; D009643:Norfloxacin; D000432:Methanol