In vitro Susceptibility Studies of the Extract, Fraction and Cream Formulation of the Leaf of Musa paradisiaca Linn against Known Dermatophytes

Aim: This study was aimed at investigating the in vitro susceptibility of known dermatophytes to Musa paradisiaca leaf extract. Methodology: The antifungal activity of the methanol extract, aqueous fraction and cream formulation of Musa paradisiaca leaf was established by agar well diffusion method while minimum inhibitory concentration (MIC) was determined by broth microdilution and broth macrodilution methods respectively. Results: Results obtained show that all the test organisms had varying degrees of susceptibility which is comparable to that of a standard drug, ketoconazole. Microsporum audounii exhibited the lowest MIC of 25 mg/mL for the aqueous fraction and 50 mg/mL for the cream formulation. The MFC/MIC ratio determined indicates the fungicidal potential of the plant. Conclusion: The in vitro susceptibility of M. paradisiaca leaf extract to known dermatophytes is an indication of the possible use of the leaf as a potential for the treatment of skin infections due to the tested organisms.

A Silent Threat of Emerging Resistance Based on Antifungal Susceptibility Pattern of Filamentous Fungi by Microdilution, E Test and, Disc Diffusion Method: A Critical Constructive Analysis

For more than two decades, antifungal susceptibility testing and interpretation haunted the medical professionals in diagnostics and management. This article mainly focuses on the three most widely used methods: broth microdilution, E test, and disc diffusion. It also focuses on the fact that clinicians should switch from empirical treatment to susceptible drugs as early as possible to combat antifungal resistance and newer mutations that horrify us every single day with poor patient outcomes. Many factors need to be taken into account during the interpretation of results but the positive side of the story is that they have been well documented in the literature. Though many methods have come up in testing antifungal susceptibility, still there is a scope for a rapid yet accurate testing modality to flourish and take the lead

GC-MS Analysis and Antimicrobial Activity of the Extract and Fractions of Bacillus subtilis subsp. subtilis 168 Isolated from a River Bank in Nigeria

The menace of drug resistant pathogens is increasing and their level of evading conventional antimicrobials is rising. It is therefore important to discover new antimicrobials to counter the current challenges. Our preliminary investigation identified Bacillus subtilis subsp. subtilis 168 isolated from soil sample sourced from a river bank in Abuja, Nigeria, as the most potent antibiotic-producing bacteria among the other identified producers. The current study screened for the antimicrobial activity of the extract and fractions of the isolate by broth microdilution method. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and the ratio of the MBC/MIC were determined. All the tested pathogens were susceptible to the ethyl-acetate extract (MIC between 28.70 mg/ml and 57.40 mg/ml). The extract displayed bactericidal activity against all tested pathogens (MBC/MIC between 1.00 and 2.00) while Proteus mirabilis was least susceptible. The extract was purified by vacuum liquid chromatography and the fractions challenged with pathogenic strains. The fraction E was the most potent (MIC between 0.09 mg/ml and 0.75 mg/ml) and also bactericidal against all the test microbes (MBC/MIC between 2.00 and 2.11). GC-MS analysis of the purified sub fraction obtained from fraction E identified 13 compounds with different Retention time and peak areas. Among these were three major compounds which include: (i) bis(2-ethylhexyl) phthalate (ii) 1,4-epoxynaphthalene-1(2H)-methanol, 4,5,7-tris(1,1-dimethylethyl)-3,4-dihydro- (iii) D:B-Friedo-B':A'-neogammacer-5-en-3-ol, (3.beta.)-. Our findings suggest that Bacillus subtilis subsp. subtilis 168 isolated locally could serve as a valuable source of lead compounds for pharmaceutical and biotechnological purposes.

Evaluación de la elución de sensidiscos para la determinación de susceptibilidad a colistín en bacilos gramnegativos multi-resistentes / Evaluation of sensi-disk elution for colistin susceptibility determination in multidrug resistant gramnegative bacilli

Resumen Utilizando cepas clínicas de bacilos gramnegativos multi-resistentes (MDR), comparamos las CIM obtenidas de la microdilución en caldo, el método de referencia y el método de elución de sensidiscos. Encontramos que, con la excepción de A. baumannii, los resultados fueron muy similares. El método de elución de sensidiscos podría ser una buena alternativa y confiable para la determinación de la resistencia a colistín.

Abstract Using clinical strains of multidrug resistant (MDR) Gram negative bacilli, we compared MICs obtained from both broth microdilution, the reference method, and sensi-disk elution method. We found that, with A. baumannii exception, results were very similar. Sensi-disk elution method could be a good and reliable alternative for colistin resistance determination.

Antibacterial Property of Synsepalum dulcificum Leaves Aqueous Extract against Oral Pathogens and its Chemical Compounds

@#Synsepalum dulcificum (S. dulcificum) commonly known as “miracle fruit” because its berries have the capability to modify sour taste to the sweet taste when eaten. Beside the berries, S. dulcificum leaves were also known to possess biological properties such as antioxidant, antimutagenic and antidiabetic activities. However, the study of its antimicrobial activity against oral pathogen is still lacking. Thus, this study aimed to evaluate the antibacterial activity of its leaves against cariogenic bacteria and to analyse its phytochemical compounds. The samples of S. dulcificum leaves were collected in Kelantan, the east coast region of Peninsular Malaysia and extracted with distilled water using a Soxhlet technique. The antibacterial activity of the S. dulcificum leaves aqueous extract against Streptococcus mutans (S. mutans), Streptococcus sobrinus (S. sobrinus) and Lactobacillus salivarius (L. salivarius) was evaluated using the broth microdilution assay. The identification of the phytochemical compounds was performed using gas chromatography-mass spectrometry (GC-MS). The antibacterial study showed the minimum inhibitory concentration of S. dulcificum leaves aqueous extract against S. mutans and S. sobrinus were 16 mg/mL and 8 mg/mL, respectively. Interestingly, there was no inhibitory effect of S. dulcificum leaves aqueous extract against L. salivarius. A total of 42 chemical compounds were identified and major identified bioactive compounds groups were heterocyclic and phenolic compounds. Our results suggested S. dulcificum leaves aqueous extract has antimicrobial properties against S. mutans and S. sobrinus, but no inhibitory activity against oral normal flora, with the presence of bioactive compounds has potential in oral care products application.

Establishment of a New Evaluation Method for Identification of Drug Resistance of Staphylococcus aureus Based on Rapid Identification System of Microorganisms / 中国实验方剂学杂志

Objective::To explore the feasibility of the rapid identification system(MALDI-Biotyper System) of microorganisms for rapid identification of Pseudomonas aeruginosa and clinical isolation of Staphylococcus aureus. Method::Identification quality control and clinical isolation were conducted for drug resistance of S. aureus by microbial rapid identification system and broth dilution method. The scores of microbial rapid identification system were compared with the MIC value of broth dilution method. The drug resistance of P. aeruginosa was simultaneously identified to determine the accuracy and applicability of the rapid identification system of microorganisms. Result::The scores of the microbial rapid identification system showed that the score of sensitive quality control strain S. aureus was higher than 2.000, and the that of resistant strain of methicillin-resistant S. aureus(methicillin-resistant S. aureus, MRSA)was between 1.700 and 2.000.The score of clinically isolated S. aureus was between 1.700 and 2.000, which suggested the drug resistance and was consistent with the MIC value of the broth dilution method. At the same time, the systemic identification value of the P. aeruginosa, which is independent of the quality control sensitive strain, was greater than 2.000, showing sensitivity and it was a sensitive strain itself, which was consistent with the results. Conclusion::The microbial rapid identification system scoring method can be used for the rapid identification of the drug resistance of S. aureus and P. aeruginosa.

Chemical composition and antimicrobial activity of two extract of propolis against isolates of Staphylococcus spp. and multiresistant bacterials / Composição química e atividade antimicrobiana de dois extratos de própolis contra isolados de Staphylococcus spp. e bactérias multirresistentes

There is a growing need to discover and develop alternative therapies for the treatment of mastitis caused by Staphylococcus spp. and multidrug-resistant bacterial infections. This study examined the chemical composition and antimicrobial potential of two propolis extracts (EPA and EPB) against seventy-seven isolates of Staphylococcus spp. obtained from subclinical bovine mastitis; three clinical strains of MRSA and two from clinical strains of S. aureus ATCC, identified as S. aureus ATCC 6538 and S. aureus ATCC 25923. The total phenolic content was determined by the Folin-Ciocalteau method, the total flavonoid content by the Dowd method and the phenolic profile was quantified by HPLC-DAD. The MBC values of the extracts were evaluated by broth microdilution method. The amount of total phenolic and flavonoid compounds was higher in EPA than EPB. Both extracts revealed the presence of caffeic, coumaric, cinnamic, ferulic and 3,4-dihydroxybenzoic acids, with higher concentrations of coumaric and cinnamic acids. Staphylococcus spp. isolates were susceptible to EPA (90.9%), EPB (83.1%) and oxacillin (80.5%). The oxacillin susceptible isolates were also susceptible to EPA (70.1%) and EPB (80.6%), whereas those oxacillin-resistant strains were also susceptible to EPA (40.0%) and to EPB (26.7%). MBC ranged from 34.3 to 68.7µm/mL for EPA and from 68.7 to 137.5µg/mL for EPB. Both extracts inhibited significantly (100%) the clinical strains of MRSA, S. aureus ATCC 6538 and S. aureus ATCC 25923 at the concentration of 68.7µg/mL. It is concluded that both extracts of propolis, whose main constituents are coumaric and cinnamic acids, have high antimicrobial activity against the microorganisms studied, and EPA also against oxacillin-resistant strains. These findings reinforce its potential use for the treatment of bovine mastitis.(AU)

É cada vez mais oportuna a necessidade de descobrir e desenvolver terapias alternativas para tratamento da mastite causada por Staphylococcus spp. e de infecções bacterianas multirresistentes. Este estudo examinou a composição química e o potencial antimicrobiano de dois extratos etanólicos de própolis (EPA e EPB) contra setenta e sete isolados de Staphylococcus spp. obtidos a partir de mastite bovina subclínica; três estirpes clínicas de MRSA e duas de linhagens clínicas de S. aureus ATCC, identificadas como, S. aureus ATCC 6538 e S. aureus ATCC 25923, ambas metacilina resistentes. O teor total de fenólicos foi determinado pelo método de Folin-Ciocalteau, o teor de flavonoides totais pelo método Dowd e o perfil fenólico foi quantificado por HPLC-DAD. CBM dos extratos foi avaliada pelo método de microdiluição em caldo. A quantidade total de compostos fenólicos e flavonoides foi maior no EPA do que no EPB. Ambos os extratos revelaram a presença dos ácidos cafeico, cumárico, cinâmico, ferúlico e 3,4-di-hidroxibenzóico, com maiores concentrações de ácidos cumárico e cinâmico. Os isolados de Staphylococcus spp. foram sensíveis a EPA (90,9%), EPB (83,1%) e oxacilina (80,5%). Os isolados suscetíveis à oxacilina também foram suscetíveis ao EPA (70,1%) e ao EPB (80,6%), enquanto os do resistente à oxacilina foram suscetíveis ao EPA (40,0%) e ao EPB (26,7%). MBC variou de 34,3 a 68,7µm/mL para EPA e de 68,7 a 137,5µg/mL para EPB. Ambos os extratos inibiram significativamente (100%) as linhagens clínicas de MRSA, S. aureus ATCC 6538 e S. aureus ATCC 25923 na concentração de 68,7µg/mL. Conclui-se que os extratos etanólicos da própolis, cujos principais constituintes são os ácidos cumário e cinâmico, possuem atividade antimicrobiana contra os micro-organismos estudados, e o EPA também contra as cepas resistentes à oxacilina. Estes achados reforçam seu potencial uso para o tratamento da mastite bovina.(AU)

Isolation, identification and antifungal susceptibility of Candida in patients with fungal sepsis

Background: In this study, our aim was to identify and isolate Candida species from patients admitted in ICU,s of our hospital and to determine their susceptibilities to various antifungal agents so as to find the local resistance pattern and guide for empirical treatment.Methods: In our study 37 strains of candida were isolated (4 Candida albicans, 33 Non-albicans Candida strains). Candida species were identified by conventional, biochemical and molecular methods. Antifungal susceptibility tests for amphotericin B, fluconazole, itraconazole, ketoconazole and voriconazole were performed with broth microdilution method and E- tests as described by National Committee for Clinical Laboratory Standards (NCCLS).Results: Out of 37 Candida strains, the most prevalent species were C. tropicalis (43.2%), C. parapsilosis (24.3%), C. krusei (16.2%), C. albicans (10.8%), and C. glabrata (2.7%). Among all strains four strains (10.8 %) were resistant, two Candida albicans where found resistant to fluconazole one Candida krusei and one Candida parapsilosis were found to be resistant to all azoles.Conclusions: Candidemia continues to be associated with substantial morbidity and mortality and non albicans Candida species are the commonly isolated pathogen from those patients admitted in tertiary care hospitals in Indian scenario. Thus, it is imperative to perform antifungal susceptibility to select appropriate and effective antifungal therapy.

Antimicrobial efficacy of fermented mango leaves beverage towards selected foodborne pathogens

Aims@#Fermented mango leaves of Chokanan variety was produced using selected symbiotic culture of bacteria and yeast (SCOBY) from MARDI’s Collection of Functional Food Cultures (CFFC). The aim of this work was to investigate its functional benefits as food remedy to reduce the risk of food poisoning illness incidence. @*Methodology and results@#Five species of foodborne pathogens: Escherichia coli O157:H7 UPMEC32 (local isolate), Salmonella typhimurium ATCC®53648™, Salmonella enteritidis MDC15 (local isolate), Listeria monocytogenes ATCC®51772™ and Streptococcus gallolyticus (ATCC®9809™) were selected to examine the antimicrobial effect of fermented mango leaves beverage by means of agar well diffusion assay and broth microdilution method to determine its minimum bactericidal concentration (MBC>99). In comparison with chemical inhibitor (acetic acid, 1%) and antibiotic (Penicillin streptomycin, 1%), the agar diffusion assay results confirmed the inhibition efficacy of fermented mango leaves beverage against all five foodborne pathogens tested. Particularly, fermented mango leaves beverage was showing a significant inhibitory effect (P<0.05) against S. gallolyticus, whereas both acetic acid and penicillin streptomycin have no inhibitory activities at all towards this pathogen. Another antimicrobial activity assay using broth microdilution method also confirmed the 100% inhibition effect of fermented mango leaves beverage against these selected pathogenic microorganisms. Furthermore, the efficacy retained 100% inhibitory activities even though the fermented mango leaves beverage has been diluted to 50%. Synergetic effect of significant amount of multiple organic acids present in fermented mango leaves beverage were the main factors contributing to its potent antimicrobial properties and improvement taste after fermentation. On the contrary, little or no antimicrobial inhibitory activity was observed in all non-fermented mango leaves beverages treated samples. @*Conclusion, significance and impact of study@#This finding indicates that the potential of fermented mango leaves beverages as prophylaxis measures to reduce the risk of food poisoning incidence as it has shown a good antimicrobial effect against selected foodborne pathogens. Moreover, this fermented mango leaves beverage are more tasteful after gone through the microbial fermentation process. It is recommended to consume daily to reduce the incidence of food poisoning illness.

Deciphering polymyxin B minimum inhibitory concentration from colistin minimum inhibitory concentration and vice versa: An analysis on 156 carbapenem-resistant Enterobacteriaceae isolates

The susceptibility determination to polymyxins (colistin and polymyxin B) remains a challenge for clinical microbiology laboratories. We evaluated the minimum inhibitory concentration (MIC) of both antimicrobials by the broth microdilution method in a selected subset of 156 carbapenem-resistant Enterobacteriaceae (CRE) isolates. Good concordance between polymyxin B and colistin MIC values was obtained, and there was 98% categorical agreement in CRE isolates. Future large-scale multicentre study is needed to draw conclusion if the MIC of colistin can be used to extrapolate the MIC of polymyxin B and vice versa.

Phytochemistry and antimicrobial activity of Campomanesia adamantium

ABSTRACT Campomanesia adamantium (Cambess.) O. Berg., Myrtaceae, is a plant popularly used for its anti-inflammatory, anti-diarrhoeal and urinary antiseptic activities. The aims of this study were to obtain the crude ethanolic extract and the hexane, dichloromethane, ethyl acetate, aqueous and concentrated aqueous tannin fractions from C. adamantium leaves, perform biomonitored fractionation to isolate and identify chemical compounds, study the chemical composition of the volatile oils of the leaves and flowers and test the antimicrobial activity of the ethanolic extract, fractions, isolated substances and volatile oils. Phytochemical screening and chromatographic and spectrometric techniques were used. Volatile oils were isolated by hydrodistillation in a Clevenger apparatus and analyzed by gas chromatography/mass spectrometry. The antimicrobial activity was tested by a broth microdilution test. The component stictane-3,22-diol was isolated and identified from the hexane fraction, while valoneic and gallic acid were isolated and identified from the concentrated aqueous tannin fraction. The major constituents of the volatile oils of the leaves were verbenene (13.91%), β-funebrene (12.05%) and limonene (10.32%), while those of the volatile oils of the flowers were sabinene (20.45%), limonene (19.33%), α-thujene (8.86%) and methyl salicylate (8.66%). Antibacterial activity was verified for the hexane fraction, while antifungal activity was observed for the aqueous fraction and concentrated aqueous tannin fraction and for vanoleic acid. These results may justify the popular use of C. adamantium.

Comparación y evaluación de métodos cuantitativos para determinar la susceptibilidad antimicrobiana de cepas del complejo Mycobacterium abscessus / Comparison and Evaluation of Quantitative Methods for Determining Antimicrobial Susceptibility of Complex Mycobacterium Abscessus Strains / Comparação e avaliação de métodos quantitativos para determinar a susceptibilidade antimicrobiana de cepas do complexo Mycobacterium abscessos

Resumen Introducción: el complejo Mycobacterium abscessus incluye especies patógenas emergentes multirresistentes, lo cual limita las opciones terapéuticas para tratar las infecciones causadas por dichos microorganismos. En este estudio se compararon las concentraciones inhibitorias mínimas (CIM) obtenidas mediante dos métodos cuantitativos, se establecieron los puntos de corte empleados en el micrométodo colorimétrico (MMC) y se evaluó la susceptibilidad antimicrobiana. Materiales y métodos: la CIM de nueve antibióticos fue determinada mediante el MMC y la microdilución en caldo (MDC) para 19 cepas del complejo M. abscessus. El test F de Snedecor se utilizó para establecer la diferencia significativa de las CIM entre los dos métodos y se determinaron los puntos de corte mediante la técnica de distribución de la probabilidad para el MMC. Resultados: se encontró una correlación de los resultados de la CIM del 50% entre MMC y MDC para los antibióticos ensayados. Probablemente esta discrepancia en los resultados se deba a diferencias en algunos parámetros técnicos de cada procedimiento. Todas las cepas fueron sensibles a la amikacina y resistentes a meropenem y ampicilina-sulbactam. Independientemente de la especie del complejo M. abscessus, las fluoroquinolonas mostraron una baja actividad inhibitoria (0-25%) sobre los aislados clínicos, resultados que son similares a los reportados por otros autores. Conclusión: Los patrones de multirresistencia observados en las cepas analizadas sugieren la necesidad de utilizar las pruebas de susceptibilidad como herramientas que permitan orientar y optimizar las conductas terapéuticas en infecciones producidas por M. abscessus.

Abstract Introduction: The Mycobacterium abscessus complex includes multidrug resistant emerging pathogens, which limit therapeutic options for treating infections caused by these microorganisms. In this study, the minimum inhibitory concentrations (MICS) obtained by 2 quantitative methods were compared, the cut-off points used in the colorimetric micromethod (CMM) were established and the antimicrobial susceptibility was evaluated. Materials and Methods: The MIC for nine antibiotics was determined by CMM and broth microdilution (BMD) for 19 strains of M. abscessus complex. The Snedecor F test was used to establish the significant difference in the CIM between the methods, cutoff points were determined by the probability distribution method for the CMM. Discussion: A correlation of 50% between CMM and BMD for antibiotics tested was found. Probably, this discrepancy in the results is due to differences in some technical parameters of each procedure. All strains were susceptible to amikacin and were resistant to meropenem and ampicillin-sulbactam. Independently of the species of M. abscessus complex, fluoroquinolones showed a low inhibitory activity (0-25%) on clinical isolates, results that are similar to those reported by other authors. Conclussion: The Multidrug resistance patterns observed in the strains tested suggest the need for susceptibility testing as tools to guide and optimize the therapeutic behavior in infections caused by M. abscessus.

Resumo Introdução: o complexo Mycobacterium abscessus inclui espécies patógenas emergentes multirresistentes, o qual limita as opções terapêuticas para tratar as infeções causadas por estes microrganismos. Neste estudo compararam-se as concentrações inibitórias mínimas (CIMS) obtidas mediante 2 métodos quantitativos, se estabeleceram os pontos de corte empregados no micrométodo colorimétrico (MMC) e se avaliou a susceptibilidade antimicrobiana. Materiais e métodos: a CIM de 9 antibióticos foi determinada mediante o MMC e microdiluição em caldo (MDC) para 19 cepas do complexo M. abscessus. O teste F de Snedecor utilizou-se para estabelecer a diferença significativa das CIMS entre os dois métodos e determinaram-se os pontos de corte mediante a técnica de distribuição da probabilidade para o MMC. Resultados: se encontrou uma correlação dos resultados da CIM do 50% entre MMC e MDC para os antibióticos testados. Provavelmente, esta discrepância nos resultados se deve a diferenças em alguns parâmetros técnicos de cada procedimento. Todas as cepas foram sensíveis à amikacina e resistentes a meropenem e ampicilina-sulbactam. Independentemente da espécie do complexo M. abscessos, as fluoroquinolonas mostraram uma baixa atividade inibitória (0-25%) sobre os isolados clínicos, resultados que são similares aos reportados por outros autores. Conclussão: Os patrões de multirresistência observados nas cepas analisadas, sugerem a necessidade de utilizar as provas de susceptibilidade como ferramentas que permitam orientar e otimizar as condutas terapêuticas em infeções produzidas por M. abscessus.

In vitro combination susceptibility testing for detecting clinical isolates of Acinetobacter baumannii by five kinds of antibiotics with sulbactam / 临床检验杂志

Objective To investigate the in vitro antibacterial activity of single cefoperazone,ceftazidime,imipenem,tigecycline and colistin and their combination with sulbactam against clinical isolates of Acinetobacter baumannii (A.baumannii).Methods Twentythree meropenem-resistant A.baumannii strains and 21 meropenem-sensitive strains from the Study for Monitoring Antimicrobial Resistance Trends (SMART) during 2011 and 2012 were collected,and their combination susceptibility tests were performed by the checkerboard dilution method.The fractional inhibitory concentration (FIC) index was calculated to evaluate the combination effect of antibiotics.Results No antagonism effect was observed for all of combinations.The combination of sulbactam with cefoperazone or tigecycline mainly produced synergistic effect on A.baumannii,and the strains with FIC index ≤0.5 accounted for 56.8％ and 50.0％,respectively.The combination of sulbactam with imipenem or colistin showed synergistic or partially synergistic effect on A.baumannii,and the strains with FIC index ＜ 1 accounted for 61.4％ and 52.3％,respectively.However,the combination of sulbactan with ceftazidime didn't show any interation,and the strains with FIC index ≥4 accounted for 63.6％.Conclusion The combination of sulbactam with cefoperazone has the best synergistic effect on A.baumannii,especially on carbapenem-sensitive A.baumannii.The combination of sulbactam with imipenem or tigecycline may enhance the antibacterial activity on carbapenem-resistant A.baumannii.The combination of sulbactam with imipenem or tigecycline may be helpful for the treatment of carbapenem-resistant A.baumannii infection.

Synthesis and antifungal activities of N-1,3,4-thiadiazol-2-yl-4-oxo-thiochroman-2-yl-formamide derivatives / 药学学报

Thiochromanones and 1,3,4-thiadazoles as heterocyclic compounds have broad biological activities. In order to find novel compounds with antifungal bioactivity, substituted thiophenol and maleic anhydride were used to synthesize the intermediate 4-oxothiochromane-2-carboxylic acid. It was reacted with 2-amino-1,3,4-thiadiazol to get fourteen target compounds containing 1,3,4-thiadazole moiety. The structures of the obtained compounds were confirmed by 1H NMR, 13C NMR and HR-MS. All compounds were investigated for antifungal activity via microdilution broth method. The results showed that the target compounds 3a and 3c to Epidermophyton floccosum and Mucor racemosus exhibited better antifungal activity than the positive control fluconazole, in which the minimum inhibition concentration can reach 8 μg·mL-1 and 16 μg·mL-1. Compound 3e showed significant inhibitory activity to Helminthosporium maydis, Sclerotinia sclerotiorum and Botrytis cinerea compared with that of the positive control carbendazim. Compound 3b exhibited inhibitory activity to Helminthosporium maydis better than the positive control carbendazim.

Susceptibilidad del género aspergillus a los antifúngicos por el método de microdilución en caldo / Susceptibility of the aspergillus genus to antifungal agents by the broth microdilution method

La aspergilosis es una micosis ocasionada por el género Aspergillus que afecta tanto a pacientes inmunocompetentes como inmunosuprimidos. La presentación clínica depende del estado inmune del hospedero y de los factores de riesgo asociados; en la medida en que progrese la inmunosupresión habrá mayor probabilidad de adquirir la enfermedad invasora que se asocia a una elevada morbimortalidad. El objetivo de este trabajo fue Establecer la susceptibilidad del género Aspergillus a diferentes antifúngicos por el método de Microdilución en caldo según el documento M38-A2, con el fin de conocer los patrones de susceptibilidad de los aislados clínicos de Aspergillus spp. Se utilizaron 76 cepas clínicas que se encuentran en resguardo en la micoteca del Departamento de Micología del Instituto Nacional de Higiene "Rafael Rangel". Se utilizaron cepas controles A. fumigatus ATCC 204305, A. flavus ATCC 204304, C. parapsilosis ATCC 22019 y C. krusei ATCC 6258. Obteniendo como resultado que las CMI más elevadas in vitro frente a las 4 especies de Aspergillus fueron Voriconazol y AmB. Itraconazol y Caspofungina reportaron las CMI más bajas y por consiguiente los PCE obtenidos se encontraron entre más o menos 2 CMI comparadas con otras investigaciones. Este estudio aportó información importante sobre el comportamiento del género Aspergillus frente a los antifúngicos más utilizados en el tratamiento de la aspergilosis en nuestro país como a nivel mundial.

Aspergillosis is a mycosis caused by the genus Aspergillus that affects both immunocompetent and immunosuppressed patients. The clinical presentation depends on the host's immune status and the associated risk factors; As immunosuppression progresses, there is a greater probability of acquiring the invasive disease that is associated with high morbidity and mortality. The objective of this work was to establish the susceptibility of the genus Aspergillus to different antifungals by the method of Microdilution in broth according to document M38-A2, in order to know the susceptibility patterns of the clinical isolates of Aspergillus spp. Seventy-six clinical strains were used in the mycology department of the National Institute of Hygiene "Rafael Rangel". Control strains A. fumigatus ATCC 204305, A. flavus ATCC 204304, C. parapsilosis ATCC 22019 and C. krusei ATCC 6258 were used. As a result, the highest MICs in vitro against the 4 Aspergillus species were Voriconazole and AmB. Itraconazole and Caspofungin reported lower MICs and therefore the PCEs obtained were found between plus or minus 2 MICs compared to other investigations. This study provided important information about the behavior of the genus Aspergillus against the most commonly used antifungals in the treatment of aspergillosis in our country as a worldwide.

Actividad antibacteriana in vitro de Curcuma longa (Zingiberaceae) frente a bacterias nosocomiales en Montería, Colombia / In vitro antibacterial activity of Curcuma longa (Zingiberaceae) against nosocomial bacteria in Montería, Colombia

ResumenLa resistencia bacteriana es un problema de salud creciente a nivel mundial que genera graves impactos económicos y sociales, comprometiendo la acción terapéutica de los antibióticos actuales. Por ello, la búsqueda de nuevos compuestos con propiedades antimicrobianas se hace más relevante en los estudios modernos, en especial frente a bacterias de interés clínico. En el presente estudio se evaluó la actividad antibacteriana in vitro del extracto etanólico y el aceite esencial de Curcuma longa L (Zingiberaceae), contra bacterias nosocomiales utilizando el método de microdilución. Se utilizaron cepas de Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus sp., Salmonella sp. y Bacillus sp., aisladas de infecciones nosocomiales en un centro hospitalario de la ciudad de Montería y cepas de referencia de S. aureus ATCC 43300, S. aureus ATCC 29213, S. aureus ATCC 25923, P. aeruginosa ATCC 27853, E. coli ATCC 25922 y K. pneumoniae ATCC 700603. El perfil antibacterial del extracto etanólico fue más evidente a las concentraciones más altas (1 000 ppm), obteniendo porcentajes de reducción significativos de más del 50 % frente a K. pneumoniae ATCC 700603 y un aislado clínico de E. coli, mientras que, frente al aislado clínico del género Bacillus fue más activo el aceite esencial. Para el resto de los microorganismos los porcentajes de reducción obtenidos a una concentración de 1 000 ppm variaron entre 17 y 42 % con el extracto etanólico y entre 8 y 43 % con el aceite esencial. A concentraciones de 100 y 500 ppm la actividad antibacteriana de los extractos fue menor. Los resultados obtenidos indican que el extracto etanólico y el aceite esencial de los rizomas de C. longa poseen compuestos activos con propiedades antibacterianas que podrían emplearse en investigaciones futuras, como una alternativa terapéutica para el tratamiento de infecciones producidas por patógenos nosocomiales.

Abstract:Bacterial resistance is a growing health problem worldwide that has serious economic and social impacts, compromising public health, and the therapeutic action of current antibiotics. Therefore, the search for new compounds with antimicrobial properties is relevant in modern studies, particularly against bacteria of clinical interest. In the present study, in vitro antibacterial activity of the ethanol extract and essential oil of Curcuma longa (Zingiberaceae) was evaluated against nosocomial bacteria, using the microdilution method. Escherichia coli strains, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus sp. were used, Salmonella sp. and Bacillus sp., isolated from nosocomial infections in a hospital in the city of Monteria and reference strains of S. aureus ATCC 43300, S. aureus ATCC 29213, S. aureus ATCC 25923, P. aeruginosa ATCC 27853, E. coli ATCC 25922 and K. pneumonia ATCC 700603. The ethanol extract antibacterial profile was more efficient at higher concentrations (1 000 ppm), obtaining significant percentages of reduction of more than 50 % against K. pneumoniae ATCC 700603 and a clinical isolate of E. coli; while compared to Bacillus clinical isolate, was more active than the essential oil. For the rest of microorganisms, the reduction percentages obtained at a concentration of 1 000 ppm varied between 17 and 42 % with ethanolic extract, and 8 to 43 % with essential oil. At concentrations of 100 and 500 ppm antibacterial activity of the extracts was lower. The results indicated that the ethanolic extract and essential oil of C. longa rhizomes have active compounds with antibacterial properties that could be used in future research as a therapeutic alternative for the treatment of infections caused by nosocomial pathogens. Rev. Biol. Trop. 64 (3): 1201-1208. Epub 2016 September 01.

Evaluation of colorimetric nitrate reductase assay for rapid detection of methicillin resistance in clinical isolates of Staphylococcus aureus.

Background & objectives: Methicillin resistant Staphylococcus aureus (MRSA) remains a major cause of health care-associated infections. Rapid detection of MRSA facilitates the early initiation of appropriate treatment and infection control. Hence, the present study was undertaken to standardize and evaluate the performance of rapid colorimetric nitrate reductase assay (NRA) for determining methicillin resistance in S.aureus. Methods: A total of 160 clinical isolates of S. aureus, (80 each of methicillin susceptible and methicillin resistant) were included in the study. Minimum inhibitory concentration (MIC) was determined by NRA and reference broth micro dilution (BMD) methods. Results of NRA were compared with BMD and analyzed. Results: For MRSA, the MIC values ranged from 4 to ≥ 16 μg/ml and for MSSA, ≤ 0.5 to 2 μg/ml. Category and essential agreement for NRA as compared with BMD were found to be 99.4 and 89.7 per cent, respectively. No minor or major discrepancy was observed. A single resistant isolate showed very major discrepancy. Interpretation & conclusions: Colorimetric NRA being an inexpensive test requiring no special equipment can be employed as an alternative method for rapid detection of MRSA in resource limited settings.

Atividade antimicrobiana in vitro das folhas de araçá (Psidium cattleianum Sabine) contra micro-organismos da mucosa oral / In vitro antimicrobial activity of leaves of araçá (Psidium cattleianum Sabine) against oral micro-organisms

Introdução: A espécie Psidium cattleianum Sabine tem despertado o interesse dos pesquisadores por apresentar, além de atividade cicatrizante, analgésica e antioxidante, propriedades antimicrobianas frente a micro-organismos da mucosa oral que podem atuar como agentes cariogênicos. Objetivo: Foi avaliada, neste trabalho, a atividade antimicrobiana de extratos bruto e fracionados das folhas do araçá, além do seu perfil cromatográfico. Material e método: Para avaliação da atividade antimicrobiana, foi utilizada a técnica de microdiluição, para determinação da Concentração Inibitória Mínima (CIM), e repique do inóculo em Ágar Muller Hinton (Himedia), para averiguação da Concentração Bactericida Mínima (CBM). O extrato foi testado nas concentrações entre 10 e 500 µg/mL. O perfil cromatográfico foi realizado pelo método de Cromatografia Líquida de Alta Eficiência (CLAE). Resultado: Os resultados obtidos foram submetidos a uma análise descritiva e foi possível observar a atividade inibitória dos extratos do P. cattleianum contra S. mutans e S. oralis. Conclusão: A atividade antimicrobiana dos extratos de P. cattleianum contra micro-organismos orais justifica maiores estudos para a utilização medicinal dessa espécie, como, por exemplo, sua utilização em enxaguantes bucais.

Introduction: The specie Psidium cattleianum Sabine has aroused the interest of researchers to exhibit, healing activity, analgesic, antioxidant, antimicrobial properties against the micro-organisms of the oral mucosa that can act as cariogenic agents. Objective: It was analyzed in this study the antimicrobial activity of crude extracts and fractions and chromatographic profile of araçá. Material and method: For antimicrobial activity, we used the technique of on broth microdilution for determining the Minimum Inhibitory Concentration (MIC) and replating of inoculum in Muller Hinton (Himedia) agar for finding the Minimum Bactericidal Concentration (MBC). The extract was tested at concentrations between 10 and 500 µg/mL. The chromatographic profile was performed by the method of High Performance Liquid Chromatography. Result: The results were submitted to a descriptive analysis was possible to observe the inhibitory activity of the extracts of P. cattleianum against S. oralis and S. mutans. Conclusion: The antimicrobial activity of P. cattleianum extracts against oral microorganisms justifies the use of this species as a medicinal plant.

Antimicrobial and antioxidant activity of essential oil and different plant extracts of Psidium cattleianum Sabine / Atividade antimicrobiana e antioxidante do óleo essencial e diferentes extratos vegetais de Psidium cattleianum Sabine

Abstract The goals of the study were to determinethe antimicrobial and antioxidant activities of essential oil and plant extracts aqueous and ethanolic of Psidium cattleianum Sabine; the chemical composition of the essential oil of P. cattleianum; and the phytochemical screening of aqueous and ethanolic extracts of the same plant. Regarding the antimicrobial activity, the ethanolic extract exhibited moderate antimicrobial activity with respect to bacteria K. pneumoniae and S. epidermidis, whereas, regarding other microorganisms, it showed activity considered weak. The aqueous extract and the essential oil showed activity considered weak, although they inhibited the growth of microorganisms. About the antioxidant potential, the ethanolic and aqueous extracts exhibited a scavenging index exceeding 90%, while the essential oil didn´t show significant antioxidant activity. Regarding the phytochemical composition, the largest class of volatile compounds identified in the essential oil of P. cattleianum included the following terpenic hydrocarbons: α-copaene (22%); eucalyptol (15%), δ-cadinene (9.63%) and α-selinene (6.5%). The phytochemical screening of extracts showed the presence of tannins, flavonoids, and triterpenoids for aqueous and ethanolic extracts. The extracts and essential oils inhibit the growth of microrganisms and plant extracts showed significant antioxidant activity. Also, the phytochemical characterization of the essential oil showed the presence of compounds interest commercial, as well as extracts showed the presence of important classes and compounds with biological activities.

Resumo Os objetivos do trabalho foram determinar as atividades antimicrobiana e antioxidante do óleo essencial e dos extratos vegetais aquoso e etanólico de Psidium cattleianum Sabine; a composição química do óleo essencial P. cattleianum e a triagem fitoquímica dos extratos vegetais aquoso e etanólico da mesma planta. Quanto à atividade antimicrobiana, o extrato etanólico apresentou atividade antimicrobiana moderada frente as bactérias K. pneumonieae e S. epidermidis, enquanto frente aos demais micro-organismos apresentou atividade considerada fraca. O extrato aquoso e o óleo essencial apresentaram atividade considerada fraca, embora tenham inibido o crescimento dos micro-organismos. Em relação ao potencial antioxidante, os extratos etanólico e aquoso apresentaram índice de sequestro superior a 90%, enquanto o óleo essencial não apresentou atividade antioxidante significativa. Para a composição fitoquímica, a maior classe de compostos voláteis identificados no óleo essencial de P. cattleianum foram os hidrocarbonetos terpênicos, sendo eles: α-copaeno (22%), eucaliptol (15%), δ-cadineno (9,63%) e α-selineno (6,5%). Na triagem fitoquímica dos extratos verificou-se a presença de taninos, flavonóides e triterpenóides tanto para o extrato aquoso quanto etanólico. Os extratos e óleo essencial inibiram o crescimento dos micro-organismos e os extratos vegetais apresentaram atividade antioxidante significativa. Também, a caracterização fitoquímica do óleo essencial mostrou a presença de compostos de interesse comercial, assim como os extratos apresentaram a presença de classes e compostos com importantes atividades biológicas.

Chemical analysis, antimicrobial and anti-oxidative properties of Daucus gracilis essential oil and its mechanism of action

Objective: To evaluate the essential oils (EO) composition, antimicrobial and antioxi-dant power of a local plant, Daucus gracilis (D. gracilis). Methods: The aerial parts of D. gracilis were subjected to hydro distillation by a Cle-venger apparatus type to obtain the EO which had been analyzed by gas chromatography and gas chromatography coupled with mass spectrometry, and screened for antimicrobial activity against five bacteria and three fungi by agar diffusion method. The mechanism of action of the EO was determined on the susceptible strains by both of time kill assay and lysis experience. The minimal inhibitory concentrations were determined by agar macro-dilution and micro-dilution methods. Anti-oxidative properties of the EO were also studied by free diphenyl-2-picrylhydrazyl radical scavenging and reducing power techniques. Results: The EO yielded 0.68 (v/w). The chemical analysis presented two dominant constituents which were the elemicin (35.3%) and the geranyl acetate (26.8%). D. gracilis EO inhibited the growth of Bacillus cereus and Proteus mirabilis significantly with minimal inhibitory concentrations of 17.15 mg/mL by the agar dilution method and 57.05 mg/mL and 114.1 mg/mL, respectively by liquid micro-dilution. A remarkable decrease in a survival rate as well as in the absorbance in 260 nm was recorded, which suggested that the cytoplasm membrane was one of the targets of the EO. The EO showed, also, important anti-oxidative effects with an IC50 of 0.002 mg/mL and a dose-dependent reducing power. Conclusions: D. gracilis EO showed potent antimicrobial and anti-oxidative activities and had acted on the cytoplasm membrane. These activities could be exploited in the food industry for food preservation.