Growth inhibition on Staphyloccoccus aureus by oils from Aloysia triphylla.

FREYTES, S.; OLIVA, M; GALLUCCI, M.; CASERO, C.; ZYAGDLO, J.; DEMO, M

Tafi del Valle (Tucuman)

Jornada; XXV Jornadas Cient¨ªficas de la Asociaci¨®n de Biolog¨ªa de Tucum¨¢n; 2008

GROWTH INHIBITION ON STAPHYLOCCOCCUS AUREUS BY OILS FROM ALOYSIA TRIPHYLLA Freytes, S.1; Oliva, M1; Gallucci, M.1; Casero, C.1; Zyagdlo, J.2; Demo, M1. 1:FacCEFQyN.UNRC. 2:FacCEFyN.UNC. mdemo@exa.unrc.edu.ar  Introduction: A.triphylla, "cedr¨®n", is aromatic (lemon like), with great importance in Argentine and international market due to sensory and medicinal properties of essential oils (EO). These have antimicrobial properties. Aims: To study the growth inhibition on S.aureus by EO from A.triphylla. Materials and methods: The EO were obtained by hydrodistilation of vegetal from La Paz (Cba), analyzed by gas chromatography and mass spectrometry (GC-MS). The strain used was S.aureus ATCC25212. The effect of inoculumm on the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), cell lysis by OD and microbial death as a function of time was analyzed. Results: Limonene (2.9%), neral(20%), geranial(29.2%), espathulenol(8.9%) and caryophyllene oxide(7%) were identified. For initial cell concentration (ICC) of 9.2x 106cfu/ml, the MIC was 1.84¦Ìg/¦Ìl and for an ICC of 4.6x 104cfu/ml the MIC was 0.23¦Ìg/¦Ìl. The MBC was 56.25¦Ìg/¦Ìl. The EO did not produce cell lysis. The time killing effect was at 2 min for twice the MBC (112.5¦Ìg/¦Ìl), at 4 min for the MBC (56.25¦Ìg/¦Ìl) and at 15 min for half the MBC (28,125¦Ìg/¦Ìl). Conclusions: The effect "cide" was reached in short periods of time. This EO could be an effective chemotherapeutic against antibiotics multirresistant S.aureus, risponsible for human and animals diseases.