RESUMO

The tendency to replace synthetic antimicrobials for natural ones in food industry and an increase in bacterial resistance to antibiotics resulted in a necessity to find new alternatives, and essential oils are emerging as promising substitutes for synthetic chemicals in food preservation. The objective of this work was to test the antimicrobial activity of oregano (OEO) and clove (CEO) essential oils over a range of bacteria, molds and yeast of importance as pathogens or food spoilage. The antimicrobial activity of oregano and clove essential oils were analyzed by disk diffusion method and broth microdilution test (MIC) of OEO and CEO were determined for each tested microorganism. OEO and CEO were evaluated in natura (IN) and after thermal processing (TP) at 120 o C for 5 min. Both OEO and CEO presented the same inhibition zones for IN and TP samples, for all tested microorganisms, indicating that these oils can be thermally processed maintaining their antimicrobial activity. For OEO and CEO, the more sensitive microorganisms were the fungi (Aspergillus niger, Penicillium citrinum and Candida albicans), followed by Staphylococcus aureus, Bacillus cereus and Methicillin - resistant Staphylococcus aureus (MRSA); the lowest antimicrobial activities were observed against Streptococcus mutans and Enterococcus faecalis. In general, OEO resulted in higher inhibition zones and lower MIC values for all tested microorganisms, suggesting that it was more effective as an antimicrobial agent than CEO (AU)

A preferência mundial para alimentos mais saudáveis e livres de aditivos químicos pelos consumidores, associada ao aumento da resistência bacteriana, resultaram na necessidade de medidas alternativas no setor de alimentos. Os óleos correspondem a antimicrobianos naturais e constituem uma classe emergente como substitutos dos produtos químicos sintéticos na conservação de alimentos. O objetivo deste trabalho foi avaliar a atividade antimicrobiana de óleos essenciais de orégano (OEO) e cravo (CEO ) frente a bactérias, fungos e leveduras de importância no setor de alimentos. OEO e CEO foram avaliados in natura (IN) e após processamento térmico (TP) a 120 o C por 5 minutos. Para avaliar a atividade antimicrobiana frente a cada microrganismo empregou-se o método de discodifusão e o teste de microdiluição em caldo (MIC). Tanto o OEO quanto o CEO apresentaram zonas de inibição semelhantes para amostras IN e TP, indicando que a atividade antimicrobiana desses óleos são resistentes a altas temperaturas. Os microrganismos mais sensíveis para ambos os óleos essenciais foram os fungos (Aspergillus niger, Penicillium citrinum e Candida albicans), seguidos por Staphylococcus aureus, Bacillus cereus e Staphylococcus aureus resistente à meticilina (MRSA). Já as cepas Streptococcus mutans e Enterococcus faecalis apresentaram uma maior resistência frente à atividade antimicrobiana dos óleos essenciais. Em geral, os maiores halos de inibição e menores valores de MIC foram obtidos quando empregado o OEO, sugerindo uma maior atividade microbiana do mesmo quando comparado ao CEO. (AU)

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RESUMO

Streptococcus equi subsp. equi es el agente etiológico de la adenitis equina, una enfermedad infecciosa que afecta al tracto respiratorio superior y linfonódulos de cabeza y cuello de equinos. La terapia antimicrobiana tradicional incluye como antibiótico de primera elección a la penicilina G (PEN), a la que los estreptococos suelen ser sensibles. El objetivo de este trabajo fue estudiar el perfil de sensibilidad a distintos antimicrobianos de cepas de S. equi que circulan en la provincia de Buenos Aires, Argentina. Se estudiaron 92 aislamientos mediante el método de difusión con discos; los antimicrobianos evaluados fueron PEN, cefotaxima, eritromicina, tetraciclina, enrofloxacina (ENR), trimetroprima-sulfametoxazol (TMS), ciprofloxacina, clindamicina (CLI), estreptomicina (STR) y florfenicol. Se determinó la concentración inhibitoria mínima (CIM) de la PEN y de aquellos antimicrobianos frente a los cuales S. equi mostró resistencia o sensibilidad intermedia. Se obtuvieron altos porcentajes de sensibilidad a todos los antimicrobianos por el método de difusión y valores de CIM por debajo de los puntos de corte para PEN, TMS y CLI. Se identificaron cepas resistentes a ENR y STR, con CIM50, CIM9o y rangos de CIM por encima de los puntos de corte. Los resultados confirman que la PEN podría utilizarse empíricamente, ya que las cepas circulantes en Buenos Aires no mostraron resistencia a este antimicrobiano. Se enfatiza en la relevancia del uso racional de los antibióticos para lograr éxito terapéutico, evitar la cronicidad, la recidiva de infecciones y la aparición de resistencia.

Streptococcus equi subsp. equi is the etiologic agent of strangles, an infectious disease affecting the upper respiratory tract and head and neck lymph nodes of equines. Routine antimicrobial therapy includes penicillin (PEN) as antibiotic of first choice. Streptococci are usually susceptible to PEN and only a few antimicrobial studies had been performed. The aim of this work was to study the antimicrobial susceptibility profile of S. equi from Buenos Aires, Argentina. Ninety-two isolates were studied by the single disk method to PEN, cefotaxime, erythromycin (ERY), tetracycline, enrofloxacin (ENR), trimethoprim sulfamethoxazole (TMS), ciprofloxacin, clindamycin (CLI), streptomycin (STR) and florfenicol. Minimum inhibitory concentration (MIC) to PEN and antibiotics with resistance and intermediate susceptibility were tested. High percentages of susceptibility were obtained by the disk diffusion method and MIC values of PEN, TMS and CLI were found to be under the breakpoint values. Resistant strains of ENR and STR with MIC50, MIC90 and MIC ranges above breakpoints were identified. These findings confirm that PEN may be used empirically because resistant strains were not found in Buenos Aires. Emphasis is placed on the rational use of antibiotics to achieve therapeutic success, to prevent chronicity, recurrence of infections and the emergence of resistance.

Assuntos

RESUMO

Streptococcus equi subsp. equi is the etiologic agent of strangles, an infectious disease affecting the upper respiratory tract and head and neck lymph nodes of equines. Routine antimicrobial therapy includes penicillin (PEN) as antibiotic of first choice. Streptococci are usually susceptible to PEN and only a few antimicrobial studies had been performed. The aim of this work was to study the antimicrobial susceptibility profile of S. equi from Buenos Aires, Argentina. Ninety-two isolates were studied by the single disk method to PEN, cefotaxime, erythromycin (ERY), tetracycline, enrofloxacin (ENR), trimethoprim sulfamethoxazole (TMS), ciprofloxacin, clindamycin (CLI), streptomycin (STR) and florfenicol. Minimum inhibitory concentration (MIC) to PEN and antibiotics with resistance and intermediate susceptibility were tested. High percentages of susceptibility were obtained by the disk diffusion method and MIC values of PEN, TMS and CLI were found to be under the breakpoint values. Resistant strains of ENR and STR with MIC50, MIC90 and MIC ranges above breakpoints were identified. These findings confirm that PEN may be used empirically because resistant strains were not found in Buenos Aires. Emphasis is placed on the rational use of antibiotics to achieve therapeutic success, to prevent chronicity, recurrence of infections and the emergence of resistance.

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RESUMO

One hundred and forty-one Candida species isolated from clinical specimens of hospitalized patients in Rio de Janeiro, Brazil, during 2002 to 2007, were analized in order to evaluate the distribution and susceptibility of these species to fluconazole. Candida albicans was the most frequent species (45.4%), followed by C. parapsilosis sensu lato (28.4%), C. tropicalis (14.2%), C. guilliermondii (6.4%), C. famata (2.8%), C. glabrata (1.4%), C. krusei (0.7%) and C. lambica (0.7%). The sources of fungal isolates were blood (47.5%), respiratory tract (17.7%), urinary tract (16.3%), skin and mucous membrane (7.1%), catheter (5.6%), feces (2.1%) and mitral valve tissue (0.7%). The susceptibility test was performed using the methodology of disk-diffusion in agar as recommended in the M44-A2 Document of the Clinical and Laboratory Standards Institute (CLSI). The majority of the clinical isolates (97.2%) was susceptible (S) to fluconazole, although three isolates (2.1%) were susceptible-dose dependent (S-DD) and one of them (0.7%) was resistant (R). The S-DD isolates were C. albicans, C. parapsilosis sensu lato and C. tropicalis. One isolate of C. krusei was resistant to fluconazole. This work documents the high susceptibility to fluconazole by Candida species isolated in Rio de Janeiro, Brazil.

Assuntos

RESUMO

One hundred and forty-one Candida species isolated from clinical specimens of hospitalized patients in Rio de Janeiro, Brazil, during 2002 to 2007, were analized in order to evaluate the distribution and susceptibility of these species to fluconazole. Candida albicans was the most frequent species (45.4%), followed by C. parapsilosis sensu lato (28.4%), C. tropicalis (14.2%), C. guilliermondii (6.4%), C. famata (2.8%), C. glabrata (1.4%), C. krusei (0.7%) and C. lambica (0.7%). The sources of fungal isolates were blood (47.5%), respiratory tract (17.7%), urinary tract (16.3%), skin and mucous membrane (7.1%), catheter (5.6%), feces (2.1%) and mitral valve tissue (0.7%). The susceptibility test was performed using the methodology of disk-diffusion in agar as recommended in the M44-A2 Document of the Clinical and Laboratory Standards Institute (CLSI). The majority of the clinical isolates (97.2%) was susceptible (S) to fluconazole, although three isolates (2.1%) were susceptible-dose dependent (S-DD) and one of them (0.7%) was resistant (R). The S-DD isolates were C. albicans, C. parapsilosis sensu lato and C. tropicalis. One isolate of C. krusei was resistant to fluconazole. This work documents the high susceptibility to fluconazole by Candida species isolated in Rio de Janeiro, Brazil.

Assuntos

RESUMO

One hundred and forty-one Candida species isolated from clinical specimens of hospitalized patients in Rio de Janeiro, Brazil, during 2002 to 2007, were analized in order to evaluate the distribution and susceptibility of these species to fluconazole. Candida albicans was the most frequent species (45.4%), followed by C. parapsilosis sensu lato (28.4%), C. tropicalis (14.2%), C. guilliermondii (6.4%), C. famata (2.8%), C. glabrata (1.4%), C. krusei (0.7%) and C. lambica (0.7%). The sources of fungal isolates were blood (47.5%), respiratory tract (17.7%), urinary tract (16.3%), skin and mucous membrane (7.1%), catheter (5.6%), feces (2.1%) and mitral valve tissue (0.7%). The susceptibility test was performed using the methodology of disk-diffusion in agar as recommended in the M44-A2 Document of the Clinical and Laboratory Standards Institute (CLSI). The majority of the clinical isolates (97.2%) was susceptible (S) to fluconazole, although three isolates (2.1%) were susceptible-dose dependent (S-DD) and one of them (0.7%) was resistant (R). The S-DD isolates were C. albicans, C. parapsilosis sensu lato and C. tropicalis. One isolate of C. krusei was resistant to fluconazole. This work documents the high susceptibility to fluconazole by Candida species isolated in Rio de Janeiro, Brazil.(AU)

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RESUMO

The antimicrobial activity of Syzygium cumini leaves extract, known as "jambolão", was evaluated. The crude hydroalcoholic extract was active against Candida krusei (inhibition zone of 14.7 ± 0.3 mm and MIC = 70 µg/mL), and against multi-resistant strains of Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus.

A atividade antimicrobiana do extrato das folhas de Syzygium cumini (Myrtaceae), conhecido como "jambolão", foi avaliada. O extrato hidroalcoólico mostrou atividade contra Candida krusei (halo de inibição de 14.7 ± 0.3 mm e CIM = 70 µg/mL) e cepas multiresistentes de Pseudomonas aeruginosa, Klebsiella pneumoniae e Staphylococcus aureus.