Características clínicas y microbiológicas de la infección de vías urinarias bajas en población ambulatoria / Clinical and Microbiological Characteristics of Lower Urinary Tract Infections in an Outpatient Population

Introducción: El tratamiento de las infecciones del tracto urinario es casi siempre empírico, lo que genera una serie de problemas en la consulta diaria. Objetivo: Caracterizar clínica y microbiológicamente las infecciones de vías urinarias bajas no complicadas en pacientes de una clínica de primer nivel. Métodos: Se realizó un estudio transversal descriptivo. La identificación de las bacterias del cultivo de orina se efectuó por métodos establecidos. La prueba de susceptibilidad a los antimicrobianos se realizó por la técnica Kirby-Bauer. Se utilizó el programa estadístico SPSS versión 26, con la prueba de ji al cuadrado y un análisis multivariado discriminante. Se calculó también razón de momios con el programa Epi-Info. Resultados: Se incluyeron 270 pacientes, con frecuencia de 39,3 por ciento de cultivos positivos, y Escherichia coli como la especie predominante. Se identificaron, además, 31,3 por ciento de bacterias Gram positivas. Se presentó significancia estadística entre la infección urinaria y factores como el sexo, y la infección del tracto urinario previa en las mujeres. Se obtuvo 100 por ciento de cepas resistentes a ampicilina. En general, se obtuvieron porcentajes de resistencia altos en los antimicrobianos probados. Conclusiones: Escherichia coli fue la especie más frecuentemente aislada, sin embargo, existe una serie de microorganismos implicados en enfermedades del tracto genital como Gardnerella vaginalis, que parecen estar involucrados en la etiología de las infecciones del tracto urinario. Se identificaron factores de riesgo como el sexo biológico y las infecciones previas en mujeres. Se obtuvieron porcentajes de resistencia altos en los antimicrobianos probados(AU)

Introduction: The management of urinary tract infections is almost always empirical, which generates a series of problems in the daily consultation. Objective: To characterize, clinically and microbiologically, uncomplicated lower urinary tract infections in patients of a primary level clinic. Methods: A descriptive and cross-sectional study was carried out. Bacterial identification in urine culture was performed by established methods. Antimicrobial susceptibility testing was performed using the Kirby-Bauer technique. The statistical software SPSS (version 26) was used, with the chi squared test and multivariate discriminant analysis. Odds ratios were also calculated with the Epi-Info program. Results: A total of 270 patients were included, with a 39.3percent frequency of positive cultures and Escherichia coli as the predominant species. In addition, 31.3percent of Gram-positive bacteria were identified. There was statistical significance between urinary tract infection and factors such as sex or previous urinary tract infection in women. One result was 100percent of ampicillin-resistant strains. In general, high percentages of resistance were obtained for the tested antimicrobials. Conclusions: Escherichia coli was the most frequently isolated species; however, there is a number of microorganisms implicated in genital tract diseases, such as Gardnerella vaginalis, which appear to be involved in the etiology of urinary tract infections. Risk factors such as biological sex and previous infections in women were identified. High percentages of resistance were obtained for the tested antimicrobials(AU)

Distribution of extended-spectrum beta-lactamase TEM and CTX-M resistance genes among Proteus species Isolated in Sudan

Proteus species are found in the human intestinal tract as part of normal flora. Proteus species are also found in multiple environmental habitats, including long-term care facilities and hospitals, and can cause both community and nosocomial infections. For a long time Proteus was known to be susceptible to beta-lactam antibiotics but nowadays they become resistant. The aim of this study was to detect the Extended-spectrum beta-lactamase (ESBL) TEM and CTX-M genes in 90 Proteus species isolated from urine and wound swabs, obtained from different hospitals in Khartoum state, Sudan, from January to August 2018. Antimicrobial sensitivity was carried out using the following set of antibiotics: amoxiclav, ceftazidime, gentamicin, meropenem, cefotaxime, ciprofloxacin, amoxicillin, ceftriaxone and cotrimoxazole. ESBL producing strains were detected by double disc diffusion synergy test and the resistance genes TEM and CTX-M were detected by Polymerase Chain Reaction (PCR). Antibiotic resistance was found: amoxicillin 40 percent, ceftazidime 25.6 percent, ceftriaxone 23.3 percent, gentamicin 22.2 percent, cotrimoxazole 21.1 percent, and cefotaxime 18.9 percent. Most of the isolates were sensitive to meropenem 92.2 percent and ciprofloxacin 86.7 percent. In double-disk diffusion synergy test, 20 isolates (22.2 percent) were found to be positive for ESBL. The PCR demonstrated that TEM gene was present in 18 isolates (90 percent). It was present alone in 11 isolates (55 percent) and in combination with CTX-M gene in seven isolates (35 percent). The percentage of ESBL producing strains of Proteus was 23.5 percent. This percentage is a bit lower than in previous studies in Sudan. In conclusion; it seems that the CTX-M gene is emerging among Proteus species in SudanAU)

Las especies de Proteus se encuentran en el tracto intestinal humano y forman parte de su flora normal. También se localizan en el medio ambiente y otros hábitats, incluyendo hospitales y diversas instituciones de salud, provocando tanto infecciones en la comunidad como nosocomiales. Durante mucho tiempo, las especies de Proteus fueron susceptibles a los antibióticos betalactámicos, pero actualmente se han tornado resistentes. El propósito de este estudio fue detectar genes de resistencia betalactamasas de espectro extendido (BLEE) TEM y CTX-M, en 90 especies de Proteus aisladas en orina y heridas, provenientes de diversos hospitales del estado de Jartum, Sudán, entre enero y agosto de 2018. La sensibilidad antimicrobiana se determinó con el siguiente juego de antibióticos: amoxiclav, ceftazidima, gentamicina, meropenem, cefotaxima, ciprofloxacina, amoxicilina, ceftriaxona y cotrimoxasol. Las cepas productoras de BLEE se detectaron mediante la técnica de sinergia de doble disco, y los genes de resistencia TEM y CTX-M mediante Reacción en Cadena de la Polimerasa (PCR). Se encontró resistencia antibiótica: amoxicilina 40 por ciento, ceftazidima 25,6 por ciento, ceftriaxona 23,3 por ciento, gentamicina 22,2 por ciento, cotrimoxasol 21,1 por ciento y cefotaxima 18,9 por ciento. La mayor parte de los aislamientos fueron sensibles a meropenem (92,2 por ciento) y ciprofloxacina (86,7 por ciento). Con la técnica de sinergia de doble disco se detectó positividad a BLEE en 20 aislamientos (22,2 por ciento). Mediante PCR se demostró que el gen que codifica TEM estaba presente en 18 aislamientos (90 por ciento); de forma aislada en 11 aislamientos (55 por ciento) y combinado con el gen CTX-M en los otros siete (35 por ciento). El porcentaje de cepas de Proteus productoras de BLEE fue de 23,5 por ciento. Este valor es ligeramente inferior que los detectados en estudios previos en Sudán. En conclusión, hay evidencias de que el gen CTX-M está emergiendo entre las especies de Proteus en Sudán(AU)

Streptococcus agalactiae - Distribuição sorotípica e relação com fatores de virulência e resistência antimicrobiana / Streptococcus agalactiae - Serotype distriburion and correlation with virulence factors and antibiotic resistance

Streptococcus agalactiae, ou Estreptococo do Grupo B, é um microrganismo que encontrado na microbiota intestinal, vaginal e/ou geniturinária de 10-30% de mulheres saudáveis. A principal infecção causada por S. agalactiae é a sepse neonatal. O bebê pode adquirir o microrganismo durante o parto ao passar pelo canal vaginal, ou até mesmo durante a gestação, caso haja ascensão de S. agalactiae para o útero. Existem diversos fatores associados à infecção do feto por S. agalactiae quando a mãe é colonizada, tais como fator CAMP, cápsula de polissacarídeos, hialuronidase, ß-citolisina/hemolisina e pili. Não existe consenso ou recomendação técnica sobre o tema no Brasil. Segundo o Caderno de Atenção Básica ao Pré-Natal, não existem estudos que levem à recomendação da antibioticoterapia intraparto. É necessário elucidar as características genotípicas de cepas de S. agalactiae isoladas no Brasil para alinhar as práticas clínicas às características fenotípicas do microrganismo. Desta forma, os objetivos deste projeto são: i) classificar cepas de S. agalactiae isoladas de gestantes e não gestantes quanto ao sorotipo capsular, por PCR Multiplex, ii) avaliar a presença e distribuição de fatores de virulência, por PCR e iii) avaliar o perfil de resistência antimicrobiana, pelo método de disco difusão e teste D. Os achados de virulência e resistência a antimicrobianos foram comparados com os sorotipos, gestação, localização geográfica e sítio de isolamento. Foram analisadas 292 cepas isoladas de gestantes e não gestantes em São Paulo, São José dos Campos e Rio de Janeiro. O sorotipo Ia foi o mais prevalente entre as cepas. Na cidade de São José dos Campos não houve diferença significativa entre a prevalência dos sorotipos Ia e V, sendo que o sorotipo V foi mais abundante do que nas cidades de São Paulo e Rio de Janeiro. O sorotipo II foi mais abundante em mulheres não gestantes do que gestantes. Não foram encontradas cepas resistentes à Penicilina e vancomicina; contudo a resistência a Cefepima, Eritromicina e Clindamicina ficou em torno de 22%. Foram encontradas diferenças entre os sorotipos quanto à resistência, genes de virulência e sítio de isolamento das cepas. Portanto essas diferenças podem se refletir no perfil epidemiológico da infecção por S. agalactiae quanto à localização geográfica também quanto à gestação. A incidência de sepse causada por S. agalactiae diminuiu muito nas últimas décadas, contudo o monitoramento constante é necessário para alinhar as práticas clínicas às características fenotípicas do microrganismo

Streptococcus agalactiae, or Group B Streptococcus, is a microorganism found in intestinal, vaginal and/or genitourinary microbiota from about 10-30% of all healthy women. The main infection caused by S. agalactiae is neonatal sepsis. The baby can contract the infection during labor when passing through the vaginal canal, or even during pregnancy, if S. agalactiae ascends from the vaginal canal to the uterus. There are several factors associated to the infection of the fetus by S. agalactiae when the mother is colonized, such as the CAMP factor, polysaccharide capsule, hyaluronidase, ß-cytolysin/hemolysin and pili. There is no consensus or technical recommendation regarding this theme in Brazil. According to the Brazilian guidelines to prenatal care, there is no research that justifies the implementation of intrapartum antibiotic therapy. There is a need to clarify genotype characteristics of S. agalactiae strains isolated in Brazil in order to align clinical practices to phenotypical characteristics of this microorganism. This way, the goals of this project are: i) to classify S. agalactiae strains isolated from pregnant and nonpregnant women according to their capsular serotype, using PCR Multiplex, ii) to evaluate the presence and distribution of virulence factors, using PCR and iii) to evaluate their antibiotic resistance profile, using disk-diffusion and D-zone tests. The findings regarding virulence and resistance were compared to serotypes, pregnancy, geographic localization and the site where the sample was isolated. A total of 292 strains from pregnant and nonpregnant women from the cities of São Paulo, São José dos Campos and Rio de Janeiro were analyzed. Serotype Ia was the most prevalent among the strains. In São José dos Campos there was no significate difference in the prevalence of serotypes Ia and V. Serotype V was the most abundant in São Paulo and Rio de Janeiro. Serotype II was most prevalent in nonpregnant women when compared to pregnant women. No resistance to Penicillin nor Vancomycin was found. However, resistance to Cefepime, Erythromycin or Clindamycin was found in around 22% of strains. There were differences among serotypes regarding resistance, virulence genes and site where the strain was isolated. Therefore these differences can reflect into the epidemiologic profile of S. agalactiae infection in regards to geographic localization and pregnancy. The incidence of sepsis caused by S. agalactiae has decrease in the last few decades, however constant monitoring is necessary in order to align clinical practice to the microorganisms phenotypical characteristics

Antimicrobial susceptibility of Brazilian Clostridium difficile strains determined by agar dilution and disk diffusion

Abstract Clostridium difficile is a leading cause of diarrhea in hospitalized patients worldwide. While metronidazole and vancomycin are the most prescribed antibiotics for the treatment of this infection, teicoplanin, tigecycline and nitazoxanide are alternatives drugs. Knowledge on the antibiotic susceptibility profiles is a basic step to differentiate recurrence from treatment failure due to antimicrobial resistance. Because C. difficile antimicrobial susceptibility is largely unknown in Brazil, we aimed to determine the profile of C. difficile strains cultivated from stool samples of inpatients with diarrhea and a positive toxin A/B test using both agar dilution and disk diffusion methods. All 50 strains tested were sensitive to metronidazole according to CLSI and EUCAST breakpoints with an MIC90 value of 2 μg/mL. Nitazoxanide and tigecycline were highly active in vitro against these strains with an MIC90 value of 0.125 μg/mL for both antimicrobials. The MIC90 were 4 μg/mL and 2 μg/mL for vancomycin and teicoplanin, respectively. A resistance rate of 8% was observed for moxifloxacin. Disk diffusion can be used as an alternative to screen for moxifloxacin resistance, nitazoxanide, tigecycline and metronidazole susceptibility, but it cannot be used for testing glycopeptides. Our results suggest that C. difficile strains from São Paulo city, Brazil, are susceptible to metronidazole and have low MIC90 values for most of the current therapeutic options available in Brazil.

Staphylococcus aureus resistance to topical antimicrobials in atopic dermatitis

Abstract: Background: Topical antimicrobial drugs are indicated for limited superficial pyodermitis treatment, although they are largely used as self-prescribed medication for a variety of inflammatory dermatoses, including atopic dermatitis. Monitoring bacterial susceptibility to these drugs is difficult, given the paucity of laboratory standardization. Objective: To evaluate the prevalence of Staphylococcus aureus topical antimicrobial drug resistance in atopic dermatitis patients. Methods: We conducted a cross-sectional study of children and adults diagnosed with atopic dermatitis and S. aureus colonization. We used miscellaneous literature reported breakpoints to define S. aureus resistance to mupirocin, fusidic acid, gentamicin, neomycin and bacitracin. Results: A total of 91 patients were included and 100 S. aureus isolates were analyzed. All strains were methicillin-susceptible S. aureus. We found a low prevalence of mupirocin and fusidic acid resistance (1.1% and 5.9%, respectively), but high levels of neomycin and bacitracin resistance (42.6% and 100%, respectively). Fusidic acid resistance was associated with more severe atopic dermatitis, demonstrated by higher EASI scores (median 17.8 vs 5.7, p=.009). Our results also corroborate the literature on the absence of cross-resistance between the aminoglycosides neomycin and gentamicin. Conclusions: Our data, in a southern Brazilian sample of AD patients, revealed a low prevalence of mupirocin and fusidic acid resistance of S. aureus atopic eczema colonizer strains. However, for neomycin and bacitracin, which are commonly used topical antimicrobial drugs in Brazil, high levels of resistance were identified. Further restrictions on the use of these antimicrobials seem necessary to keep resistance as low as possible.

Actividad antibacteriana in vitro de propóleos chilenos sobre Helicobacter pylori / In vitro antibacterial activity of Chilean propolis against Helicobacter pylori

Introduction: Propolis is a natural product derived from beekeeping. It has anesthetic, anti-inflammatory, immune-stimulant and antibacterial properties on grampositive and gramnegative bacteria. However, little is known regarding its activity on Helicobacter pylori. This bacteria colonizes about half of the world’s population and is associated with chronic gastritis, peptic ulcer and gastric cancer. Objective: The aim of this study was to evaluate the inhibitory activity of 22 propolis extracts from nine of the 11 beekeeping Chilean regions on 10 strains of H. pylori isolated from gastric mucosa. Methods: The antibacterial activity of the extracts was determined using the well diffusion method and diffusion disks. Results: 100% of the extracts were active on the tested strains, showing inhibition halos equal to or greater than 15 mm by both methods. Conclusions: our results show an effective anti H. pylori activity of propolis. However, additional microbiological studies are needed before a potential clinical utility of these natural products is warranted.

Introducción: El propóleos es un producto natural derivado de la apicultura que tiene propiedades anestésicas, anti-inflamatorias, inmuno-estimulantes y antibacterianas. Ejerce su acción sobre distintas bacterias grampositivas y gramnegativas. Sin embargo, es muy poco lo que se sabe en relación a su actividad sobre H. pylori, bacteria asociada con gastritis crónica, úlcera gastro-duodenal y cáncer gástrico y que coloniza a alrededor de la mitad de la población mundial. Objetivo: Evaluar la actividad inhibitoria de 22 extractos de propóleos de orígenes botánicos diferentes, provenientes de nueve de las once zonas mielíferas de Chile, en la época de otoño, sobre 10 cepas de H. pylori aisladas de mucosa gástrica. Metodología: La actividad antibacteriana de los extractos se determinó a través del método de difusión en pocillos y de difusión en discos. Resultados: 100% de los extractos fueron activos sobre las cepas ensayadas, observándose halos de inhibición iguales o mayores a 15 mm en ambos métodos. Conclusiones: Los datos obtenidos in vitro en el presente estudio muestran una efectiva actividad anti H. pylori de los propóleos chilenos, siendo necesario estudios microbiológicos y farmacológicos adicionales para avanzar en una posible utilidad clínica de estos productos naturales.

Antifungal Susceptibility In Vitro Determined by the Etest(r) for Candida Obtained from the Oral Cavity of Irradiated and Elderly Individuals

This study aimed to evaluate the in vitro antifungal susceptibility of Candida species of head-and-neck-irradiated patients (Group 1), non-institutionalized (Group 2) and institutionalized elders (Group 3) using Etest(r) methodology. Candida was isolated from saliva and presumptively identified by CHROMagar Candida(r), confirmed by morphological criteria, carbohydrate assimilation (API 20C AUX(r)) and genetic typing (OPE 18). The collection was made from 29, 34 and 29 individuals (Groups 1, 2 and 3, respectively) with 67 isolates. Etest(r) strips (ketoconazole, itraconazole, fluconazole, amphotericin B and flucytosine) on RPMI (Roswell Park Memorial Institute) agar, on duplicate, were used to evaluate susceptibility. ATTC (American Type Culture Collection) 10231 (Candida albicans) was used as quality control. Among the 67 isolates of Candida species, most were susceptible to azoles, flucytosine and amphotericin B. None of the isolates showed resistance and dose-dependent susceptibility to amphotericin B. There were nine strains resistant to itraconazole, six to fluconazole and two to ketoconazole and ten dose-dependent, mainly to flucytocine. The highest MIC (minimum inhibitory concentration) to C. albicans, C. tropicalis, C. parapsilosis was 2.671 μg.mL-1, 8.104 μg.mL-1, 4.429 μg.mL-1, all for flucytosine. C. krusei and C. glabrata were associated with higher MIC for azoles and C. glabrata with higher MIC to flucytosine. In summary, susceptibility to all tested antifungal agents was evident. The isolates were more resistant to itraconazole and dose-dependent to flucytosine. A comparison of C. albicans in the three groups showed no outliers. Higher MIC was associated with C. krusei and C. glabrata.

Esse estudo objetivou avaliar a susceptibilidade antifúngica in vitro de espécies de Candida obtidas de pacientes irradiados em cabeça e pescoço (Grupo 1), idosos não institucionalizados (Grupo 2) e idosos institucionalizados (Grupo 3) usando a metodologia Etest(r). Candida foi isolada da saliva e identificada presuntivamente pelo teste CHROMagar Candida(r), confirmada pelo critério morfológico, assimilação de carboidratos API 20C AUX(r) e identificação genética (OPE 18). A coleta foi feita em 29, 34 e 29 indivíduos (Grupos 1, 2 and 3, respectivamente) com 67 isolados. As fitas de Etest(r) (cetoconazol, itraconazol, fluconazol, anfotericina B and flucitosina) em meio ágar RPMI (Roswell Park Memorial Institute), em duplicata, foram utilizados para avaliar a susceptibilidade. A ATTC (American Type Culture Collection) 10231 (Candida albicans) foi usada como controle de qualidade. Dos 67 isolados de espécies de Candida, a maioria foi susceptíveis aos azoles, flucitosina e anfotericina B. Nenhum dos isolados mostrou resistência ou susceptibilidade dose-dependente a anfotericina B. Houve nove espécies resistentes ao itraconazol, seis ao fluconazol e duas ao cetoconazol e dez dose-dependentes, principalmente a flucitosina. Os maiores valores de MIC (mínima concentração inibitória) para C. albicans, C. tropicalis, C. parapsilosis foram, respectivamente, 2,671 μg.mL-1, 8,104 μg.mL-1, 4, 429 μg.mL-1, todos para a flucitosina. C. krusei e C. glabrata foram associadas a um maior MIC para azoles e C. glabrata com maior MIC para flucitosina. Em resumo, a susceptibilidade a todos os antifúngicos testados foi evidente. Os isolados foram mais resistentes ao itraconazol e dose dependentes para a flucitosina. A comparação para C. albicans nos três grupos não mostrou diferença. Os maiores valores de MIC estavam relacionados a C. krusei e C. glabrata.

Estudo comparativo da susceptibilidade de isolados clínicos de Cryptococcus neoformans (Sanfelice, 1895) frente a alguns antifúngicos de uso hospitalar e extratos vegetais obtidos de plantas medicinais da região semiárida sergipana / Comparative study of the susceptibility of clinical isolates of Cryptococcus neoformans (Sanfelice) against some antifungal agents of hospital use and plant extracts obtained from medicinal plants of the semiarid Sergipe region, Brazil

O uso de plantas medicinais no combate as micoses é uma prática comum nas comunidades rurais e, neste contexto, o objetivo desse trabalho foi analisar o perfil de sensibilidade de isolados clínicos de C. neoformans frente a extratos brutos aquosos e antifúngicos de uso hospitalar utilizando a técnica de difusão em disco. Esses produtos naturais foram obtidos de plantas medicinais popularmente utilizadas por comunidades do sertão sergipano. Foram analisados os extratos brutos aquosos de juazeiro (Ziziphus joazeiro Mart.), catingueira (Caesalpinia pyramidalis Tul.), quixabeira (Bumelia sartorum Mart.) e jatobá (Hymenaea courbaril L.). Do juazeiro foi testado o extrato preparado a partir do infuso da entrecasca e da decocção da folha. Da catingueira foi utilizado o extrato preparado a partir do infuso das folhas. Da quixabeira o extrato utilizado foi preparado a partir da decocção da entrecasca e do jatobá maceração da entrecasca. Todos esses produtos naturais foram submetidos aos seguintes tratamentos: exposição ou não a luz ultravioleta e autoclavagem (121ºC por 10minutos). Em paralelo as leveduras patogênicas foram testadas frente aos seguintes antifúngicos de uso hospitalar: anfotericina B, fluconazol, Itraconazol, Miconazol e cetoconazol. Todos os extratos brutos aquosos apresentaram ação antifúngica frente a todas as linhagens clínicas de Cryptococcus neoformans. O tratamento de submeter à autoclavagem e exposição à luz ultravioleta apresentaram melhores resultados de ação antifúngica. Sendo que o tratamento de autoclavar o extrato bruto aquoso prevaleceu estatisticamente com os melhores resultados. Outros estudos de atividade antimicrobiano são necessários para corroborar a ação antimicótica dos produtos natuais testados, como pro exemplo killer-time e fracionamento do teste de micodiluição. No teste de sensibilidade dos antifúngicos realizado foi demonstrado que as leveduras apresentaram resistência preocupante ao fluconazol e a itraconazol pelo método de difusão em disco. Para novos conhecimentos desse perfil de resistência há necessidade de testes de melhor acurácia, como por exemplo, microdiluição. Para tanto, deve-se padronizar os testes de sensibilidade quando há uso de produtos naturais oriundos de plantas medicinais, além de fornecer alternativas de uso aos pacientes cometidos por essa levedura com fornecimento de dados científicos que comprovem a ação dos produtos naturais e plantas medicinais de largo uso no sertão sergipano.

The use of medicinal plants to combat mycoses is a common practice in rural communities, and, in this context, the aim of this study was to analyze the sensitivity of clinical isolates of C. neoformans in relation to aqueous crude extracts and antifungal agents of hospital use using the disc diffusion technique. These natural products were obtained from medicinal plants popularly used empirically by backland communities in Sergipe, Brazil. The aqueous crude extracts of Ziziphus joazeiro Mart., Caesalpinia pyramidalis Tul., Bumelia sartorum Mart. and Hymenaea courbaril L. were analyzed. From the Ziziphus joazeiro Mart., we tested the extract prepared from the infusion of the inner bark and the decoction of the leaf. From the Caesalpinia pyramidalis Tul., the extract used was prepared from the infusion of the leaves. From Bumelia sartorum Mart., the extract used was prepared from the decoction of the bark, and from the Hymenaea courbaril L. we prepared the extract from the maceration of the inner bark. All these natural products were subjected to the following treatments: exposure to ultraviolet light or not and autoclaving (121°C for 10minutes). Amphotericin B, fluconazole, itraconazole, miconazole and ketoconazole were tested. All aqueous crude extracts showed antifungal activity against all clinical strains of Cryptococcus neoformans. The treatment that underwent autoclaving and exposure to ultraviolet light showed better results for antifungal action. The treatment with autoclaving of the aqueous crude extract statistically prevailed with the best results. There is the need to perform some treatments using these natural products based on the tested medicinal plants for better antifungal activity against this pathogenic yeast so they become more effective. In the antifungal susceptibility test performed, it was demonstrated that the yeast had worrying resistance to fluconazole and itraconazole by the disc diffusion method. FOr further knowledge on this resistance profile, there is the need of tests with greater accuracy, such as the microdilution test. To do so, susceptibility testing must be standardized when there is the use of natural products derived from medicinal plants, in addition to the provision of alternative uses by patients affected by this yeast, providing scientific data demonstrating the use and action of the natural products and medicinal plants of wide use in Sergipe, Brazil.

Combined Use of the Modified Hodge Test and Carbapenemase Inhibition Test for Detection of Carbapenemase-Producing Enterobacteriaceae and Metallo-beta-Lactamase-Producing Pseudomonas spp

BACKGROUND: We evaluated the combined use of the modified Hodge test (MHT) and carbapenemase inhibition test (CIT) using phenylboronic acid (PBA) and EDTA to detect carbapenemase-producing Enterobacteriaceae (CPE) and metallo-beta-lactamase (MBL)-producing Pseudomonas spp. METHODS: A total of 49 isolates of CPE (15 Klebsiella pneumoniae carbapenemase [KPC], 5 Guiana extended-spectrum beta-lactamase [GES]-5, 9 New Delhi metallo-beta-lactamase [NDM]-1, 5 Verona integron-encoded metallo-beta-lactamase [VIM]-2, 3 imipenem-hydrolyzing beta-lactamase [IMP], and 12 oxacillinase [OXA]-48-like), 25 isolates of MBL-producing Pseudomonas spp. (14 VIM-2 and 11 IMP), and 35 carbapenemase-negative controls were included. The MHT was performed for all isolates as recommended by the Clinical and Laboratory Standards Institute. Enhanced growth of the indicator strain was measured in mm with a ruler. The CIT was performed by directly dripping PBA and EDTA solutions onto carbapenem disks that were placed on Mueller-Hinton agar plates seeded with the test strain. RESULTS: Considering the results of the MHT with the ertapenem disk in Enterobacteriaceae and Pseudomonas spp., the CIT with the meropenem disk in Enterobacteriaceae, and the imipenem disk in Pseudomonas spp., three combined disk tests, namely MHT-positive plus PBA-positive, EDTA-positive, and MHT-positive plus PBA-negative plus EDTA-negative, had excellent sensitivity and specificity for the detection of KPC- (100% sensitivity and 100% specificity), MBL- (94% sensitivity and 100% specificity), and OXA-48-like-producing isolates (100% sensitivity and 100% specificity), respectively. CONCLUSIONS: Combined use of the MHT and CIT with PBA and EDTA, for the detection of CPE and MBL-producing Pseudomonas spp., is effective in detecting and characterizing carbapenemases in routine laboratories.

Ertapebem disk performance to predict Klebsiella pneumoniae carbapenemase produced by Gram-negative bacilli isolated in a São Paulo city public hospital / Desempenho do disco de ertapenem como preditor da produção de Klebsiella pneumoniae carbapenemase por bacilos Gram-negativos isolados de culturas em um hospital municipal de São Paulo

OBJECTIVE: To evaluate ertapenem disk performance to predict Klebsiella pneumonie carbapenemase production by Gram-negative bacilli. METHODS: All Gram-negative bacilli isolated between January 2010 and June 2011 were tested by disk diffusion (OxoidTM) for sensitivity to ertapenem, meropenem and imipenem. Resistant or intermediate sensitivity strains (diameter <22 mm for ertapenem) were also tested for the blaKPC gene by polymerase chain reaction. Disk predictive positive value for Klebsiella pneumoniae carbapenemase and specificity were calculated. RESULTS: Out of the 21839 cultures performed, 3010 (13.78%) were positive, and Gram-negative bacilli were isolated in 708 (23.52%) of them. Zone of inhibition diameter for ertapenem disk was <22 mm for 111 isolates, representing 15.7% of all Gram-negative isolates. The PCR assay for blaKPC detected 40 Klebsiella pneumoniae carbapenemase-producing strains. No strains intermediate or resistant to meropenem and imipenem were sensitive to ertapenem. The ertapenem disk presented a positive predictive value of 36% to predict blaKPC and 89% specificity. CONCLUSION: The resistance of Gram-negative bacilli detected by disk diffusion against ertapenem does not predict Klebsiella pneumoniae carbapenemase production. Other mechanisms, such as production of other betalactamases and porin loss, may be implicated. The need to confirm the presence of the blaKPC is suggested. Therefore, ertapenem was a weak predictor for discriminating strains that produce Klebsiella pneumoniae carbapenemase.

OBJETIVO: Avaliar o desempenho do disco de ertapenem para predizer micro-organismos produtores de Klebsiella pneumoniae carbapenemase. MÉTODOS: Bacilos Gram-negativos isolados em cultura entre janeiro de 2010 e junho de 2011 foram testados por disco-difusão (OxoidTM) para ertapenem, meropenem e imipenem. As cepas consideradas intermediárias ou resistentes (halo<22mm) para ertapenem foram encaminhadas para a pesquisa do blaKPC por reação em cadeia da polimerase. Calcularam-se o valor preditivo positivo e a especificidade do disco. RESULTADOS: Foram realizadas 21.839 culturas nesse período, sendo 3.010 (13,78%) positivas. Bacilos Gram-negativos foram isolados em 708 (23,52%) destas. A zona de inibição do disco de ertapenem foi <22mm para 111 (15,67%) dos isolados. A pesquisa do blaKPC caracterizou 40 cepas produtoras de Klebsiella peneumoniae carbapenemase. Não houve nenhum caso de disco intermediário ou resistente para meropenem ou imipenem com ertapenem sensível. O valor preditivo positivo foi de 36% e a especificidade calculada do disco de ertapenem para produção de Klebsiella pneumoniae carbapenemase foi de 89% em nosso serviço. CONCLUSÃO: A resistência ao disco de ertapenem não define bacilo produtor de Klebsiella pneumoniae carbapenemase. Mecanismos, como produção de outras betalactamases e perda de porinas, podem estar implicados. Sugerese a necessidade da confirmação da presença do gene blaKPC. O ertapenem, portanto, mostrou-se fraco preditor para discriminar cepas produtoras de Klebsiella pneumoniae carbapenemase.

Caracterização molecular dos mecanismos de resistência à linezolida em estafilococos coagulase-negativos e estudo da estabilidade do fenótipo resistente / Linezolid resistance in negative-coagulase staphylococci: characterization and stability of resistant phenotype

Linezolid was the first agent of the oxazolidinone class to be introduced clinically. This oxazolidinone inhibits protein biosynthesis by preventing the formation of the initiation complex that consists of the mRNA, the f-Met tRNA and the 50S subunit of the ribosome. Although linezolid resistance has been mediated by the cfr-encoded product or by ribosomal proteins (L3, L4 and L22), the most common mechanism of resistance involves mutations in the central loop of domain V of the 23S rRNA gene. From March 2008 to December 2011, 38 coagulase-negative staphylococci (CNS) strains (20 S. epidermidis, 14 S. haemolyticus, 3 S. hominis e 1 S. warneri) exhibiting resistance to linezolid were isolated from blood and catheter cultures from patients in two tertiary care hospitals in the State of São Paulo and were included in this study for the ascertainment of the resistance mechanisms to this antimicrobial agent and for the analysis of the stability of this resistance. The strains exhibited high-level resistance to linezolid (MICs 16-128 µg/ml) and all were multidrug resistant, remaining susceptible to vancomycin and teicoplanin. The G2576T mutation in domain V region of 23S rRNA was identified in all isolates, except in a linezolid-resistant S. haemolyticus strain. The cfr gene and mutations in ribosomal proteins L4 and L22 were not detected. Regarding L3 protein analysis, all S. epidermidis strains of hospital A, including the linezolid-susceptible control strain, showed the L3 Leu101Val mutation, suggesting that this alteration is probably not involved in linezolid resistance. The one strain from hospital B (S. epidermidis) was wild-type for this ribosomal protein. Only one S. haemolyticus strain had a mutation in the L3 protein, Val154Leu. Two S. hominis strains showed Gly139Arg/Met156Thr mutations whereas one strain had Phe147Ile in L3 protein. The identification of these mutations in L3 protein of the linezolid-resistant S. haemolyticus and S. hominis strains strengthens the role of these sites in the acquisition of linezolid resistance in Staphylococcus spp. However, the presence of G2576T in the 23S rRNA gene makes difficult to determine exactly the role of L3 mutations in conferring elevated linezolid MIC values showed by these clinical strains. In the absence of antibiotic pressure, after 130 passages, linezolid resistance was stable in the clinical strains of this study, which did not have all copies of the 23S rRNA gene mutated, according to the restriction of the domain V fragment with NheI enzyme. Sequencing of the individual copies of the 23S rRNA gene in the serially passaged strains showed G2576T in all amplified copies by PCR: 4/4 and 5/5 in S. epidermidis and 3/3 in S. haemolyticus strains (MIC of 16-32 µg/ml). The stability of the mutant rRNA copy was also observed in the linezolid-susceptible S. epidermidis strain (MIC of 4 µg/ml). After the passages in antibiotic-free medium, the linezolid MIC of this strain fell to 1 µg/ml and the G2576T mutation persisted in one 23S rRNA gene copy. The clonal relatedness of the strains was determined by PFGE and revealed a clonal dissemination of different CNS species. Regarding MLST analysis, all S. epidermidis strains belonged to the sequence type ST2 (CC2). Most likely, the increased selective pressure has contributed to the selection of endemic linezolid-resistant CNS clones showing the G2576T mutation that have been disseminated in the institution A since 2008. Differently, the restricted use of linezolid in the institution B could explain the occurrence of a single resistant strain since 2005

Efeito antimicrobiano do cianoacrilato em bactérias bucais / Antimicrobial effect of cyanoclylate in oral bacteria

Objetivo: O objetivo deste estudo foi avaliar as propriedades antimicrobianas do etil-cianoacrilato (Super Bonder®).Materiais e métodos: O método utilizado foi o de Difusão em meio sólido – orifício em agar contra S.aureus, S. mutans, S. oralis, S. epidermidis, E. faecalis, E.coli and B. subtilis. A ação bacteriostática foi observada através da medi-ção dos halos de inibição e a bactericida através do repique.Resultados: Todos os microrganismos foram inibidos na presence do Super Bonder®, apresentando halos que variaram de 2 a 12 mm. Porém, todos apresentaram crescimento após o repique, o que significa que o Super Bonder® é apenas bacteriostático.Conclusão: foi concluído que o Super Bonder® (Loctite) apresenta propriedades antimicrobianas na inibição do crescimento por contato

Objective: The aim of this study was to evaluate antimicrobial properties of ethyl-cyanoacrylate (Super Bonder®).Materials and methods: The method used was Diffusion in Solid Mean - Orifice in Agar against S.aureus, S. mutans, S. oralis, S. epidermidis, E. faecalis, E.coli and B. subtilis. The bacteriostatic action was observed through the measurement of inhibition halos and the bactericidal one for rebound piece of halo of each nutrient.Results: All microorganisms had been inhibited in the presence of Super Bonder®, presenting halos that had varied of 2 to 12 mm. However, all the microorganisms had presented growth after rebound, what it means that the Super Bonder® is only bacteriostatic.Conclusion: It was concluded that the Super Bonder® (Loctite) presents antimicrobial properties that inhibit the bacterial growth for contact

Reliability of Kirby-Bauer disk diffusion method for detecting meropenem resistance among non-fermenting gram-negative bacilli.

Background: Meropenem is empirically used as a last resort for the treatment of infections by non-fermenting gram-negative bacilli (NFGNB). Minimum inhibitory concentration (MIC) determined using agar or broth dilution methods is widely used for testing meropenem resistance. However, it is not possible in resource-poor settings. Aim: A prospective study was performed to evaluate the reliability of Kirby-Bauer disk diffusion (KBDD) method for detecting meropenem resistance among NFGNB. Materials and Methods: A total of 146 NFGNB consisting of 56 Acinetobacter baumannii, 24 Acinetobacter lwoffii, 48 Pseudomonas aeruginosa and 18 Pseudomonas spp. were included in the study. All the isolates were tested simultaneously by both KBDD method and agar dilution method. Results: Very major errors were not observed with A. baumannii, A. lwoffii and P. aeruginosa, while other Pseudomonas spp. showed a very major error rate of about 5.6%. The major error rates observed with A. baumannii, A. lwoffii, P. aeruginosa and Pseudomonas spp. were 1.8%, 0%, 2.1% and 28.6%, respectively. All the isolates showed a good correlation between zone diameters (KBDD method) and MICs (agar dilution method). The sensitivity and specificity of KBDD method for detecting meropenem resistance was above 90% for all the NFGNB except Pseudomonas spp. Conclusions: The KBDD method can be reliably used for routine testing of meropenem resistance in A. baumannii, A. lwoffii and P. aeruginosa. However, further studies are needed before employing this technique for detecting meropenem resistance in Pseudomonas spp.

Determinación de la susceptibilidad de cepas de Helicobacter pylori a Levofloxacino en formato pequeño y método de difusión en disco usando Agar yema de huevo / Antimicrobial susceptibility of helicobacter pylori to levofloxacin determined in a miniwell format and disk diffusion tests using egg yolk agar

OBJETIVOS: Determinar la concentración mínima inhibitoria (CMI) de Levofloxacino en cepas de HELICOBACTER PYLORI (HP). MATERIALES Y MÉTODOS: Se evaluaron 95 cepas peruanas de HP en métodos de agar dilución y difusión en disco, así como el coeficiente Pearson (r) y el efecto del inóculo. RESULTADOS: 36,9% (35 de 95) fueron resistentes a Levofloxacino (CMI>1μg/ml). CMI90 fue 16ug/ml (IC:90%). CMI de Levofloxacino no viró ante diferentes concentraciones del inóculo. r:-0,733 (p<0,001). CONCLUSIONES: La proporción de HP resistentes a Levofloxacino en Perú es mayor a la observada en países desarrollados. Se recomienda evaluar periódicamente la susceptibilidad antimicrobiana para elegir óptimas conductas terapéuticas.

OBJECTIVES: To determine the Minimum inhibitory concentration (MIC) of Levofloxacin against HELICOBACTER PYLORI (HP). MATERIALS AND METHODS: 95 HP Peruvian strains were evaluated in Agar dilution and Disk diffusion tests, as well as the Pearson Coefficient (r) and the inoculum’s effect. RESULTS: 36.9% (35 of 95) were resistant (MIC>1μg/ml) to Levofloxacin. MIC90 was 16ug/ ml (CI:90%). MIC of Levofloxacin did not change at different inoculum concentrations. r: -0.733 (p<0.001). CONCLUSIONS: The proportion of HP Levofloxacin resistant strains in Peru is higher than in developed countries. Periodic testing of antibiotic susceptibility is warranted to select the most accurate therapies.

Evaluation of cefaclor oral suspensions stability using reversed phase high performance liquid chromatography and antimicrobial diffusion methods

The effect of temperature stresses on Cefaclor suspensions under different storage conditions for a duration of 14 days was tested. The degradation of Cefaclor was determined on the 2[nd], 7[th] and 14[th] day after reconstitution using a sensitive and precise Reversed phase High Performance Liquid Chromatographic [RP-HPLC] method. The RSD values for Forticef, Midocef, Ceclor, Cefabac and Cloracef, indicated a good precision of the RP-HPLC method. The limit of detection [LOD] and the limit of quantification [LOQ] were found 0.008 mg/ml and 0.03mg/ml respectively. The antimicrobial effect of Cefaclor suspension was also tested against pathogenic bacteria using the cylinder diffusion method. The RSD values range of the antimicrobial assay for all the Cefaclor compounds were 1.47-3.7%. The LOD and LOQ were 0.2mg/ml and Img/ml respectively. During the normal use of Ceclor, Midocef, and Forticef the loss of activity and the degradation were less than 5% on the 14[th] day of preservation at 4°C. However, the percentage of degradation for Cefabac and Cloracef on the 14th day reached 5 and 6%, respectively. Statistical multiple comparison between the effect of 4°C and 25°C indicated non significant mean differences [P >/= 0.05] for Forticef, Cefabac, Ceclor and Cloraf and significant effect for Midocef [P

Screening da Atividade Antifúngica de Óleos Essenciais sobre Cepas de Candida / Screening of Essential Oils Antifungal Activity on Candida Strains

Objetivo: O propósito desse estudo foi identificar a atividade antifúngica de óleos essenciais sobre cepas de Candida envolvidas com infecções da cavidade bucal. Método: Foram avaliados óleos essenciais obtidos a partir das seguintes espécies vegetais: Citrus reticulata (Tangerina Cravo); Citrus aurantifolia (Limão Tahiti); Cinnamomum zeylanicum (Canela); Matricaria chamomilla (Camomila Azul); Mentha piperita (Menta); Eugenia uniflora (Pitanga) e Zingiber officinale (Gengibre). A determinação da atividade antifúngica foi realizada utilizando a técnica de difusão em meio de cultura sólido, onde discos de papel de filtro foram embebidos nos óleos e colocados em placas de Petri contendo agar Sabouraud Dextrose inoculado com cepas de Candida albicans e C. tropicalis. Também foi observada a concentração inibitória mínima a partir do método da microdiluição. Os ensaios foram realizados em duplicata. Resultados: Foi observada expressiva atividade antifúngica dos óleos essenciais de C. zeylanicum, C. aurantifolia e M. piperita, que apresentaram diâmetros de halos de inibição de crescimento microbiano de até, respectivamente, 48 mm, 30 mm e 19 mm. Ainda foi possível identificar que 66,7% das cepas ensaiadas mostraram-se resistentes aos óleos essenciais de C. reticulata, M. chamomilla, E. uniflora e Z. officinale. O C. zeylanicum e nistatina apresentaram, respectivamente, CIMs de 312 µg mL-1 e 32 µg mL-1. Conclusão: Os óleos essenciais avaliados apresentam atividade antifúngica, sendo os melhores resultados encontrados para C. zeylanicum. Sugere-se a realização de outros ensaios para avaliação de atividade anti-Candida desse óleo essencial, que pode representar possível agente terapêutico no tratamento de infecções fúngicas da cavidade bucal

Objective: The purpose of this study was to identify the antifungal activity of essential oils on Candida strains involved in oral cavity infections. Methods: essential oils obtained from the following species were evaluated: Citrus reticulata (Cravo Tangerine) Citrus aurantifolia (Tahiti Lime), Cinnamomum zeylanicum (Cinnamon), Matricaria chamomilla (Blue Chamomile), Mentha piperita (Mint), Eugenia uniflora (Pitanga) and Zingiber officinale (Ginger). The determination of antifungal activity was performed using the diffusion technique on solid medium, where filter paper discs were soaked in oils and placed in Petri dishes containing Sabouraud dextrose agar inoculated with strains of Candida albicans and C. tropicalis. It was also observed the minimum inhibitory concentration from the microdilution method. Tests were performed in duplicate. Results: We observed significant antifungal activity of essential oils ofC. zeylanicum, C. aurantifolia and M. piperita, which had halos of microbial growth inhibition with diameters up to 48 mm, 30 mm and 19 mm, respectively. Still, it was possible to identify that 66.7% of strains tested were resistant to essential oils of C. reticulata, M. chamomilla, E. uniflora and Z. officinale. C. zeylanicum and nystatin showed µg mL-1 and 32 µg mL-1 MIC, respectively. Conclusion: The essential oils tested have antifungal activity, with best results for C. zeylanicum. It is suggested to conduct other tests for evaluation of anti-Candida activity of this essential oil, which could represent possible therapeutic agent in the treatment of fungal infections of the oral cavity

Avaliação in vitro da sensibilidade da Corynebacterium pseudotuberculosis frente a diferentes tipos de antissépticos e desinfetantes e determinação de sua curva de crescimento / In vitro evaluation of the susceptibility of Corynebacterium pseudotuberculosis to different kinds of antiseptics and disinfectants, and the determination of its growth curve

O objetivo deste estudo foi avaliar o efeito in vitro de antissépticos e desinfetantes contra a Corynebacterium pseudotuberculosis e descrever a curva de crescimento deste micro-organismo em caldo de infusão de cérebro e coração adicionado de 0,1% de Tween 80 (BHI + T), ao longo de 48 horas. Foram avaliados tintura de iodo a 10%, hipoclorito de sódio a 2,5%, permanganato de potássio a 5%, sabonete líquido antisséptico Aseptol® e álcool etílico absoluto (99,8%), por meio da metodologia da disco-difusão. Um swab estéril foi imerso na suspensão bacteriana produzida e semeado em placa de ágar Mueller-Hinton. Discos estéreis foram embebidos em cada solução a ser testada e distribuídos na superfície do ágar. Os resultados foram obtidos de acordo com o diâmetro do halo produzido ao redor dos discos. Para obtenção da curva de crescimento, colônias isoladas do micro-organismo foram inoculadas em frasco contendo BHI + T. A cada quatro horas, 2 mL eram retirados para medição da massa celular em espectrofotômetro e 1 mL para realização das diluições seriadas, plaqueamento em ágar sangue e contagem de células viáveis. Observou-se que, para a obtenção de uma concentração máxima de C. pseudotuberculosis, próxima a 1.200 x 105 células viáveis/mL, deve-se manter o inóculo sob incubação adequada por um período de 28 a 40 horas. Quanto à prova de sensibilidade, verificou-se que a tintura de iodo a 10%, seguida pelo hipoclorito de sódio a 2,5% e permanganato de potássio a 5%, foram os antissépticos e desinfetantes com maior poder bactericida in vitro contra a C. pseudotuberculosis.

The aim of this study was to evaluate the in vitro effect of antiseptics and disinfectants against Corynebacterium pseudotuberculosis, and to define the growth curve of this microrganism inoculated in brain heart infusion broth plus 0.1% of Tween 80 (BHI + T), for 48 hours incubation. For the susceptibility test, evaluations were made using 10% iodine, 2.5% sodium hypochlorite, 5% potassium permanganate, Aseptol® liquid soap, and absolute ethyl alcohol (99.8%), by way of the disc-diffusion method. A sterile swab was immersed in a bacterial suspension and plated in Mueller-Hinton agar. Sterile discs were immersed in each solution to be tested and distributed on the agar surface. The results were obtained according to the inhibition circle diameter formed around the disc. For the growth curve determination, colonies were inoculated in a bottle containing BHI + T. Every 4 hours, 2 mL was withdrawn to evaluate the cell mass in a spectrophotometer, and 1 mL was taken to perform serial dilutions, blood agar base plating and counting of viable cells. It was observed that in order to reach the maximum concentration of C. pseudotuberculosis, close to 1,200 x 105 viable cells/mL, the inoculum must be maintained at appropriate incubation for a period of 28-40 hours. The sensibility test indicated.

Prevalence of phenotypic resistance of Staphylococcus aureus isolates to macrolide, lincosamide, streptogramin B, ketolid and linezolid antibiotics in Turkey

The incidence of drug-resistant pathogens differs greatly between countries according to differences in the usage of antibiotics. The purpose of this study was to investigate the phenotypic resistance of 321 methicillin resistance Staphylococcus aureus (MRSA) and 195 methicillin susceptible S. aureus (MSSA) in a total of 516 S. aureus strains to macrolide, lincosamide, streptogramin B (MLS B), ketolid, and linezolid. Disk diffusion method was applied to determine MLS B phenotype and susceptibility to different antibiotic agents. It was found that 54.6 percent of the isolates were resistant to erythromycin (ERSA), 48 percent to clindamycin, 55 percent to azithromycin, 58.7 percent to spiramycin, 34.7 percent to telithromycin, and 0.4 percent to quinupristin-dalfopristin, respectively. No strain resistant to linezolid was found. The prevalence of constitutive (cMLS B), inducible (IMLS B), and macrolides and type B streptogramins (M/MS B) among ERSA isolates (237 MRSA, 45 MSSA) was 69.6 percent, 18.2 percent, and 12.2 percent in MRSA and 28.9 percent, 40 percent, and 31.1 percent in MSSA, respectively. In conclusions, the prevalence of cMLS B was predominant in MRSA; while in MSSA strains, iMLS B and M/MS B phenotype were more higher than cMLS B phenotype resistance. The resistance to quinupristindalfopristin was very low, and linezolid was considered as the most effective antibiotic against all S.aureus strains.

Caracterización de ß-lactamasas de espectro extendido (BLEE) en cepas nosocomiales de K. pneumoniae Sucre-Venezuela / Characterization of extended-spectrum ß-lactamases in nosocomial strains of Klebsiella pneumoniae Sucre Venezuela

En este estudio, 25 cepas de K. pneumoniae aisladas de pacientes con infección nosocomial durante el periodo agosto 2002 a diciembre de 2003 fueron examinadas para determinar su susceptibilidad antimicrobiana, perfil plasmídico, transferencia de determinantes de resistencia y los tipos de genes blaTEM , blaSHV , blaCTX-M. Diecinueve cepas presentaron susceptibilidad disminuida a las cefalosporinas de tercera generación y al aztreonam y fueron productoras de ß-lactamasas de espectro extendido (BLEE). Todas las cepas presentaron plásmidos transferibles con una frecuencia de conjugación de 10-3 a 10-4 transconjugantes/célula donante. El análisis de los patrones de restricción reveló la presencia de tres tipos de plásmidos. Las cepas E. coli transconjugantes, además de ser productoras de BLEE, expresaron resistencia a aminoglucósidos y cloranfenicol. Se encontró la presencia del gen blaTEM en todos los plásmidos transferibles y los genes blaSHV y blaCTX en plásmidos transferibles y no transferibles. Las enzimas identificadas fueron TEM-1, SHV-5-2a y CTX-M-2. Los plásmidos presentes en las cepas de K. pneumoniae, juegan un papel importante en la diseminación de los genes que codifican resistencia a los ß-lactámicos y otros antimicrobianos.

In this study, 25 strains of K. pneumoniae, isolated from patients with nosocomial infections from August 2002 to December 2003, were examined to determine their antimicrobial susceptibility, plasmid profile, transfer capacity of resistance determinants and blaTEM, blaSHV, and blaCTX-M genes. Nineteen nosocomial strains revealed a weakened susceptibility to third-generation cephalosporins and aztreonam, and were extended-spectrum ß-lactamases (ESBLs) producers. All strains presented conjugable plasmids with a conjugation frequency of 10-3 to 10-4 transconjugants/donor cell. The analysis of restriction patterns revealed the presence of three differents plasmids. The Escherichia coli transconjugants were ESBLs producers and expressed resistance for aminoglucosides and chloramphenicol. The blaTEM gen was found in all transferables plasmids and the blaSHV and blaCTX genes were found in transferables and no transferables plasmids. The enzymes identified in the isolates were TEM-1 SHV-5-2a and CTX-M-2. The plasmids present in the K. pneumoniae strains play an important role in the dissemination of the genes encoding resistance to ß-lactams and other antimicrobial agents.

Novel antimicrobial secondary metabolites from a Penicillium sp. isolated from Brazilian cerrado soil / Nuevos metabolitos antimicrobianos secundarios de Penicillium sp. aislada en suelo del cerrado de Brasil

The morphological features of a Penicillium, isolated from Brazilian cerrado soil, were characterized and showed to be distinctly different from all well-defined Penicillium species. Chemical and biological investigation on the ethyl acetate extract of this Penicillium isolate resulted in the isolation of three new naphthalenoids: a major metabolite, methyl 6-acetyl-4-methoxy-5,7,8-trihydroxynaphthalene-2-carboxylate and two minor ones, methyl 6-acetyl-4-methoxy-7,8-dihydroxynaphthalene-2-carboxylate and methyl 6-acetyl-4-methoxy-5,8-dihydroxynaphthalene-2-carboxylate. Their structures were determined based on their mono and bidimensional nuclear magnetic resonance data. Acetyl, allyl and methoxyl derivatives of the major metabolite were prepared in order to establish structure-activity relation. Antimicrobial activity of the major natural product and its semi-synthetic derivatives was screened by macro dilution methodology and the corresponding minimum inhibitory concentrations were determined. Natural secondary metabolite methyl 6-acetyl-4-methoxy-5,7,8-trihydroxynaphthalene-2-carboxylate, isolated in a very high yield (0.3175 mg.L-1) showed to be the most active compound, possessing expressive activity against Candida albicans (minimum inhibitory concentration (MIC) 32 ug/mL), Listeria monocitogenes and Bacillus cereus (MIC 64 µg/mL for both).