Acut e Otitis Externa is an inflammation of the outer auditory meatus, and according to popular saying, medicinal plant extracts can be used in its treatment. Aim: to assess the in vitro antimicrobial activity of the following plants: Aleolanthus suaveolens; Caryophyllus aromaticus; Cymbopogon citratus; Matricaria chamomila; Pithecellobium avaremotemo; Plectranthus amboinicus and Ruta graveolens on the germs that cause otitis externa. Materials and Methods: the minimum inhibitory concentration of extracts and oils from these plants was obtained from otitis externa samples. Results: Staphylococcus aureus in 10 cultures, Pseudomonas aeruginosa in 8, Pseudomonas aeruginosa and Staphylococcus aureus together in 5 cultures and Candida albicans and Candida krusei in 4 cultures. P. aeruginosa was resistant to all oils and extracts tested; extracts from A. suaveolens, P. avaremotemo and R. graveolens were inactive; the essential oil from C. aromaticus and M. chamomila were active against 3 strains of S. aureus and the Candida strains; seven of the S. aureus strains were sensitive to the P. amboinicus extract; however, the oil was inactive against 4 S. aureus strains and the Candida strains were sensitive to the R. graveolens essential oil. Conclusion: depending on the etiological agent, some plants presented satisfactory results, however we still need more detailed studies in order to better use these plants.

This study aimed to evaluate the antibacterial activity of Origanum vulgare L. and O. majorana L. essential oils on Staphylococcus aureus, S. coagulase negative, Enterobacter spp., Proteus spp., Acinetobacter spp., Klebsiella spp. isolated from the patients with conjunctivitis. The results showed a prominent inhibitory effect of both the essential oils on all the bacterial strains, noted by the large bacterial growth inhibition zones (15-32mm). The Minimum Inhibitory Concentrations (MIC) values were between 5-20µL/mL and 2.5-10 µL/mL for O. vulgare and O. majorana essential oil, respectively. The MIC were able to cause significant (P<0.05) inhibitory effect on the cell viability of Klebsiella spp., Proteus spp. and S. aureus providing a total elimination of the bacterial inoculum in a maximum time of 24 h of exposure. These results showed the antibacterial effectiveness of O. vulgare and O. marjorana essential oils and supported the possibility of their use as the sources of alternative antimicrobial compounds.
Este estudo objetivou analisar a atividade antibacteriana do óleo essencial de O. vulgare L. and O. majorana L. sobre cepas bacterianas (Staphylococcus aureus, S. coagulase negative, Enterobacter spp., Proteus spp., Acinetobacter spp., Klebsiella spp.) isoladas de pacientes com conjuntivite. Os resultados mostraram um destacável efeito inibitório de ambos os óleos essenciais ensaiadossobre todas as cepas bacterianas, notado pela formação de amplas zonas de inibição do crescimento bacteriano (15-32 mm). Os valores de Concentração Inibitória Mínima - CIM encontradas estiveram entre 5-20µL/mL e 2.5-10 µL/mL para o óleo essencial de O. vulgare e O. majorana, respectivamente. Os valores de CIM foram capazes de causar significante efeito inibitório sobre a viabilidade celular de Klebisiella spp., Proteus spp. e S. aureus causando uma total eliminação do inóculo microbiano em um tempo máximo de 24 h de exposição. Estes resultados mostraram a efetividade antibacteriana dos óleos essenciais de O. vulgare e O. majorana, bem como suporta a possibilidade do uso de tais produtos como fontes de compostos antimicrobianos

Acut e Otitis Externa is an inflammation of the outer auditory meatus, and according to popular saying, medicinal plant extracts can be used in its treatment. Aim: to assess the in vitro antimicrobial activity of the following plants: Aleolanthus suaveolens; Caryophyllus aromaticus; Cymbopogon citratus; Matricaria chamomila; Pithecellobium avaremotemo; Plectranthus amboinicus and Ruta graveolens on the germs that cause otitis externa. Materials and Methods: the minimum inhibitory concentration of extracts and oils from these plants was obtained from otitis externa samples. Results: Staphylococcus aureus in 10 cultures, Pseudomonas aeruginosa in 8, Pseudomonas aeruginosa and Staphylococcus aureus together in 5 cultures and Candida albicans and Candida krusei in 4 cultures. P. aeruginosa was resistant to all oils and extracts tested; extracts from A. suaveolens, P. avaremotemo and R. graveolens were inactive; the essential oil from C. aromaticus and M. chamomila were active against 3 strains of S. aureus and the Candida strains; seven of the S. aureus strains were sensitive to the P. amboinicus extract; however, the oil was inactive against 4 S. aureus strains and the Candida strains were sensitive to the R. graveolens essential oil. Conclusion: depending on the etiological agent, some plants presented satisfactory results, however we still need more detailed studies in order to better use these plants.