ResumoDiversos microrganismos podem ser veiculados por alimentos causando doenças nos seres humanos. Os antibióticos comumente utilizados no tratamento dessas doenças têm apresentado baixo ou nenhum efeito, tendo em vista à resistência que muitos microrganismos têm adquirido. Diante deste quadro, o objetivo desta pesquisa foi avaliar o óleo essencial das folhas de Rosmarinus officinalis L. como modulador da resistência bacteriana a drogas. O óleo essencial foi obtido através de hidrodestilação em aparelho de Clevenger por 3h. Foram testadas 4 cepas de E.coli resistentes a Ampicilina (AMP) e a Tetraciclina (TET) e 4 cepas de Salmonella spp. resistentes a Nitrofurantoína (NIT). As cepas em suspensão escala MacFarland 0,5 foram inoculadas em agar Mueller Hinton, em seguida os discos dos antibióticos embebidos com 10 e 20μL do óleo de alecrim puro foram dispostos sobre as placas. Após 24h/37ºC foram medidos os halos ao redor dos discos. Todas as cepas avaliadas apresentaram susceptibilidade à ação combinada do óleo essencial com os antibióticos testados. Os resultados obtidos indicam ser promissora a utilização de óleo essencial de alecrim em associação com antibióticos no combate a bactérias patogênicas. Palavras-chave: Óleo essencial, alecrim, resistência bacteriana AbstractMicroorganisms can be transmitted by food causing diseases in humans. The antibiotics commonly used in treatment of these diseases have shown little or no effect, and in view of the resistance that many microorganisms have acquired. This study evaluated the essential oil leaves of Rosmarinus officinalis L. as a modulator of resistance bacterial drug. The essential oil was obtained by hydrodistillation in a Clevenger apparatus for 3 hours. We tested four strains of E.coli resistant ampicillin (AMP) and tetracycline (TET) and four strains of Salmonella spp. Resistant to nitrofurantoin (NIT). The strains in 0.5 MacFarland scale suspension were inoculated on Mueller Hinton agar, then soaked antibiotic disks with 10 and 20μL oil pure rosemary were placed on the plates. After 24h/37 º C were measured halos around the discs. All strains tested showed susceptibility to the combined action of essential oil with antibiotics tested. The results indicate that the use of promising rosemary essential oil in combination with antibiotics to combat pathogenic bacteria.

Antibiotic resistance has increased in recent years, raising the concern of public health authorities. We conducted a study of Escherichia coli isolates obtained from human and food samples to assess the prevalence of antimicrobial resistance and to determine the genotype and clonal relationship of 84 E. coli isolates (48 from humans and 36 from foods). An antimicrobial susceptibility test was performed using the disk diffusion method. Virulence factors were evaluated by multiplex PCR, and the clonal relationship among the resistant isolates was studied by Pulsed Field Gel Electrophoresis (PFGE). All isolates were susceptible to ceftriaxone. Overall, 26%, 20.2%, 15.4% and 6% of the isolates were resistant to tetracycline, ampicillin, sulfamethoxazole/trimethoprim and cephalotin, respectively. Twenty two percent of the isolates exhibited resistance to more than one antimicrobial agent. Multiple-drug resistance was mostly observed in the human isolates and involved the antibiotics ampicillin and tetracycline. None of the six virulence genes were identified among the isolates. Analysis of genetic diversity by PFGE of 31 resistant isolates, revealed 29 distinct restriction patterns. In conclusion, E. coli from humans and foods are resistant to commonly used antibiotics and are highly genetically diverse. In this setting, inappropriate use of antibiotics may be a cause of high resistance rate instead of clonal spread.