Antimicrobial activities of six essential oils commonly used as condiments in Brazil against Clostridium perfringens

Abstract Despite recent advances in food production technology, food-borne diseases (FBD) remain a challenging public health concern. In several countries, including Brazil, Clostridium perfringens is among the five main causative agents of food-borne diseases. The present study determines antimicrobial activities of essential oils of six condiments commonly used in Brazil, viz., Ocimum basilicum L. (basil), Rosmarinus officinalis L. (rosemary), Origanum majorana L. (marjoram), Mentha × piperita L. var. Piperita (peppermint), Thymus vulgaris L. (thyme) and Pimpinella anisum L. (anise) against C. perfringens strain A. Chemical compositions of the oils were determined by GC–MS (gas chromatography–mass spectrometry). The identities of the isolated compounds were established from the respective Kováts indices, and a comparison of mass spectral data was made with those reported earlier. The antibacterial activity was assessed from minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) using the microdilution method. Minimum inhibitory concentration values were 1.25 mg mL-1 for thyme, 5.0 mg mL-1 for basil and marjoram, and 10 mg mL-1 for rosemary, peppermint and anise. All oils showed bactericidal activity at their minimum inhibitory concentration, except anise oil, which was only bacteriostatic. The use of essential oils from these common spices might serve as an alternative to the use of chemical preservatives in the control and inactivation of pathogens in commercially produced food systems.

Prevalência e perfil de resistência de Escherichia coli em uroculturas positivas no município de Triunfo/RS / Prevalence and resistance profile of Escherichia coli in positive urocultures in Triunfo, RS

Introdução: As infecções do trato urinário (ITU) são um importante problema de saúde pública na atualidade, e sua prevalência varia com o sexo e a idade dos pacientes. É bastante comum que o tratamento empírico seja instituído antes da identificação do agente etiológico, gerando um consumo inadequado de antibióticos. O principal agente etiológico dessas infecções é a Escherichia coli (E. coli), que apresenta importantes variações em relação à sua suscetibilidade aos antimicrobianos. O presente trabalho visa determinar a prevalência de patógenos responsáveis pelas infecções no trato urinário, relacionando-os com seu perfil de suscetibilidade aos antimicrobianos utilizados, no intuito de nortear o tratamento mais adequado. Métodos: Trata-se de um estudo transversal, retrospectivo das uroculturas realizadas no laboratório LAPEM, localizado na cidade de Triunfo/RS, no período compreendido entre julho/2010 e junho/2011. Foram selecionados todos os exames bacteriológicos de urina e realizada a verificação quanto à positividade e perfil de resistência para amostra que apresentava crescimento de E. coli, considerando os antimicrobianos de escolha, fluorquinolonas (ciprofloxacina, norfloxacina e levofloxacina), betalactâmicos (ampicilina, imipenem e ceftazidima), aminoglicosídeos (amicacina e gentamicina), ácido nalidíxico, sulfametoxazol/trimetroprim, nitrofurantoína e amoxicilina/ácido clavulânico. Resultados: No perí- odo, realizaram-se 1.274 uroculturas, com 28,89% das amostras demonstrando crescimento de algum agente bacteriano patogênico e 71,11% dos cultivos, sem crescimento algum. Das amostras positivas, 44,6% exibiam o crescimento de E. coli. Conclusão: Assim, os resultados obtidos neste estudo apresentam importância epidemiológica, visto que subsidiam a escolha mais adequada no manejo terapêutico do perfil regional de distribuição de patógenos.

Introduction: Urinary tract infections (UTI) are a major public health problem today, and their prevalence varies according to patient gender and age. It is quite common for empiric treatment to be instituted before identification of the etiologic agent, generating an inappropriate use of antibiotics. The main etiological agent of these infections is Escherichia coli (E. coli), which shows significant variations regarding its susceptibility to antibiotics. This study aims to determine the prevalence of pathogens responsible for urinary tract infections, relating them to their susceptibility profile to the antibiotics used, in order to guide the most appropriate treatment. Methods: This is a cross-sectional, retrospective study of urine cultures performed in the LAPEM laboratory, located in Triunfo, RS, from July 2010 to June 2011. We selected all urine bacteriological tests and checked their positivity and sample resistance profile showing growth of E. coli, considering the antimicrobials of choice, fluoroquinolones (ciprofloxacin, norfloxacin and levofloxacin), beta-lactams (ampicillin, imipenem and ceftazidime), aminoglycosides (amikacin and gentamicin), nalidixic acid, sulfamethoxazole/trimethoprim, nitrofurantoin and amoxicillin/ clavulanic acid. Results: During the study period, 1,274 urine cultures were performed, with 28.89% of samples showing growth of some pathogenic bacterial agent and 71.11% without any growth. From the positive samples, 44.6% exhibited growth of E. coli. Conclusions: The findings of this study have epidemiological significance, as they support the most appropriate choice in the therapeutic management of the regional profile of pathogen distribution.