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)

Beta-lactams susceptibility testing of penicillin-resistant, ampicillin-susceptible Enterococcus faecalis isolates: a comparative assessment of Etest and disk diffusion methods against broth dilution.

This study aimed to evaluate the accuracy of disk diffusion and Etest methods, compared to that of the broth dilution reference method for identifying beta-lactam susceptibilities of Penicillin-Resistant, Ampicillin-Susceptible Enterococcus faecalis (PRASEF) isolates. Fifty-nine PRASEF and 15 Penicillin-Susceptible, Ampicillin-Susceptible E. faecalis (PSASEF) clinical nonrepetitive isolates were evaluated. The effectiveness of five beta-lactams (ampicillin, amoxicillin, imipenem, penicillin, and piperacillin) was tested. All antimicrobial susceptibility tests were performed and interpreted according to the Clinical and Laboratory Standards Institute guidelines. Interpretative discrepancies, such as essential agreement, categorical agreement, and errors, were assessed. The acceptability was ≥ 90% for both categorical agreement and essential agreement. Etest proved to be an accurate method for testing beta-lactam susceptibilities of the emerging PRASEF isolates, disk diffusion presented poor performance, particularly for imipenem and piperacillin.

Polymyxin B broth disk elution: a feasible and accurate methodology to determine polymyxin B susceptibility in Enterobacterales.

Determination of polymyxins susceptibility by clinical laboratories is a nightmare, mainly because of physicochemical properties of the drug. Elution tests have already been proposed for colistin, but not for polymyxin B. We aimed to evaluate accuracy of Polymyxin B broth disk elution (PBDE) to determine the susceptibility to this drug. We evaluated 196 Enterobacterales (45.9% polymyxin B-resistant). PBDE was done in 15-mL cation-adjusted Mueller-Hinton broth where one polymyxin B disk (300 U) was eluted (2 µg/mL). BMD was performed as reference method. Categorical Agreement (CA), Major Error (ME) and Very Major Error (VME) were 99.5%, 0% and 1.11% (one false-negative K. pneumoniae MIC 4 µg/mL), respectively. As some institutions preferably use polymyxin B over colistin and in some countries colistin are not commercially available, to specifically evaluate polymyxin B is important. PBDE proved to be a cheap and easy to perform methodology to evaluate susceptibility to polymyxin B among Enterobacterales.

An alternative disk diffusion test in broth and macrodilution method for colistin susceptibility in Enterobacteriales.

Colistin and polymyxin B are old drugs that have been reintroduced to treat Gram-negative infections lacking other treatment options; however, colistin resistance have been reported. To know the correct susceptibility pattern is mandatory for multidrug resistant bacteria. Broth microdilution method is the gold standard to evaluate colistin and polymyxin B susceptibility; nevertheless, it is time consuming and needs expertise to be performed. Disk diffusion method on Müeller-Hinton agar is no longer recommended to evaluate polymyxins susceptibility. In this study we evaluated two methods (disk diffusion in broth and broth macrodilution) as alternative options to identify polymyxin resistance in an easy way. A total of 536 Enterobacteriales isolates were assessed for colistin susceptibility. All non-wild type Enterobacteriales (41) were chosen and 31 wild type bacteria were randomly selected, were used to perform disk diffusion tests in broth and for broth macrodilution tests. We found 100% of concordance between both tested methods and broth microdilution. In conclusion, these two methods are reliable and easier options that complement as initial screening susceptibility for colistin in Enterobacteriales in microbiology laboratories lacking personnel and infrastructure to perform broth microdilution method.

Detection of plasmid-mediated colistin resistance by colistin pre-diffusion and inhibition with EDTA test (CPD-E) in Enterobactereaceae.

A phenotypic assay based on colistin pre-diffusion and differential inhibition of Mobile Colistin Resistance (MCR) protein activity by EDTA showed that, of the 92 strains tested, all MCR producers (49) exhibited an increase ≥5 mm in the inhibition zone around the area of pre-diffusion in the presence of EDTA, in comparison with colistin alone. Results suggest that CPD-E may differentiate MCR-producing microorganisms from resistant microorganisms without this marker.

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

Staphylococcus aureus resistance to topical antimicrobials in atopic dermatitis.

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.

Oxacillin disk diffusion testing for the prediction of penicillin resistance in Streptococcus pneumoniae.

Objective To 1) describe the correlation between the zones of inhibition in 1-µg oxacillin disk diffusion (ODD) tests and penicillin and ceftriaxone minimum inhibitory concentrations (MICs) of meningeal and non-meningeal strains of Streptococcus pneumoniae and 2) evaluate the usefulness of the ODD test as a predictor of susceptibility to penicillin in S. pneumoniae and as a quick and cost-effective method easily implemented in a routine clinical laboratory setting. Methods S. pneumoniae isolates from healthy nasopharyngeal carriers less than 2 years old, obtained in a multicentric cross-sectional study conducted in various Peruvian hospitals and health centers from 2007 to 2009, were analyzed. Using Clinical and Laboratory Standards Institute (CLSI) breakpoints, the correlation between the zones of inhibition of the ODD test and the MICs of penicillin and ceftriaxone was determined. Results Of the 571 S. pneumoniae isolates, 314 (55%) showed resistance to penicillin (MIC ≥ 0.12 µg/mL) and 124 (21.7%) showed resistance to ceftriaxone (MIC ≥ 1 µg/mL). Comparison of the ODD test zones of inhibition and the penicillin MICs, using the CLSI meningeal breakpoints, showed good correlation (Cohen's kappa coefficient = 0.8239). Conclusions There was good correlation between ODD zones of inhibition and penicillin meningeal breakpoints but weak correlation between the ODD results and non-meningeal breakpoints for both penicillin and ceftriaxone. Therefore, the ODD test appears to be a useful tool for predicting penicillin resistance in cases of meningeal strains of S. pneumoniae, particularly in low- and middle- income countries, where MIC determination is not routinely available.

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.

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

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 2µg/mL. Nitazoxanide and tigecycline were highly active in vitro against these strains with an MIC90 value of 0.125µg/mL for both antimicrobials. The MIC90 were 4µg/mL and 2µg/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.

Susceptibilidad antimicrobiana en aislamientos cubanos de Vibrio cholerae O1 procedentes de muestras clínicas / Antimicrobial susceptibility in Cuban isolates of Vibrio cholerae O1 obtained from clinical samples

Introducción: la re-emergencia de cólera en Haití estableció un nuevo reservorio para el incremento de la séptima pandemia. Esto provocó su diseminación a República Dominicana y a otros países de la región del Caribe, como Cuba y México.Objetivo: estudiar la susceptibilidad antimicrobiana de aislamientos de Vibrio cholerae O1, serotipo Ogawa, biotipo El Tor aisladas de pacientes durante el evento epidemiológico de cólera ocurrido en Cuba entre junio de 2012 y agosto de 2013.Métodos: se realizó el estudio de la susceptibilidad antimicrobiana in vitro en 144 aislamientos de V. cholerae, mediante el método de Bauer-Kirby frente a nueve antimicrobianos: ampicilina, sulfonamida, trimetoprim/sulfametoxazol, cloranfenicol, tetraciclina, doxiciclina, azitromicina, ciprofloxacina y gentamicina, según las normas del Instituto de Estándares de Laboratorio Clínico de los Estados Unidos de América.Resultados: el total de los aislamientos resultaron resistentes al trimetoprim-sulfametoxazol; el 98,7 % lo fue a la sulfonamida y el 90,3 % a la ampicilina. Se obtuvieron valores de sensibilidad intermedia para ciprofloxacina (30,6 %) y cloranfenicol (27,1 %). Se apreciaron niveles de sensibilidad superior al 92 % a los antimicrobianos de primera línea en el tratamiento de la enfermedad (doxiciclina, tetraciclina y azitromicina), así como también a la gentamicina. No se observaron cepas multirresistentes.Conclusiones: los datos aportados por este trabajo demuestran la efectividad in vitro de los antimicrobianos utilizados en el tratamiento la enfermedad diarreica aguda causada por V. cholerae en Cuba(AU)

The combined-disk boronic acid test as an accurate strategy for the detection of KPC carbapenemase in Central America.

INTRODUCTION: Carbapenemase-producing Klebsiella pneumoniae (KPC) outbreaks may cause a huge economical burden on developing countries. Furthermore, KPC can be challenging to detect. We describe the laboratory strategy for the detection of KPC from 2011 to 2013 in a tertiary care hospital in Central America with approximately 1,000 beds. METHODOLOGY: A retrospective analysis of a clinical laboratory database was done to determine the pragmatic application of the combined-disk boronic acid test during a KPC outbreak in Panama. A total of 1,026 Klebsiella pneumoniae isolates were found, of which 133 were positive for KPC. The strategy during two phases was described according to the test employed as a confirmatory test for KPC. After the K. pneumoniae isolates were detected by the VITEK 2 system, blaKPC polymerase chain reaction (PCR) and the combined-disk boronic acid test were employed as a confirmatory test during phase one. The combined-disk boronic acid test was employed as a confirmatory test for KPC during phase two. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of the boronic acid test were 100%, 97%, 91%, and 100%, respectively, when blaKPC PCR was employed as a confirmatory test during the start of the outbreak. Afterwards, modified VITEK 2 system parameters resulted in 116 suspicious KPC samples and the boronic acid test confirmed 102 isolates. CONCLUSIONS: The use of an automated bacterial identification system and the boronic acid test for the detection of KPC was an effective and low-cost strategy for a clinical laboratory in Panama during an outbreak.

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

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.

Evaluation of polymyxin susceptibility profile among KPC-producing Klebsiella pneumoniae using Etest and MicroScan WalkAway automated system.

Determination of polymyxin susceptibility profile is important to monitor resistance rates and for implementing control measures for polymyxin-resistant carbapenem-resistant Enterobacteriaceae. Some laboratorial methods have been used to determine the polymyxin susceptibility profile. However, the performance of MicroScan WalkAway has been poorly reported for KPC-producing Klebsiella pneumoniae, so far. To evaluate two different methods, Etest and the MicroScan automated system, in determining minimal inhibitory concentration (MIC) of polymyxin among KPC-producing K. pneumoniae isolated from patients in two care units (ICUs) of a tertiary hospital in Porto Alegre, Southern Brazil. A total of 101 KPC-Kb isolates were obtained from rectal swabs and clinical specimens (urine, blood, and endotracheal aspirate). Colistin and polymyxin B MICs were determined using MicroScan WalkAway automated system and Etest, respectively. Discrepant results were resolved by broth microdilution (BMD). MicroScan showed 88.1% of sensitivity for predicting polymyxin B resistance in KPC-producing K. pneumoniae compared to the results obtained by Etest. All discrepant results were tested by BMD and these were concordant with results obtained by Etest. The MicroScan automated system does not seem to be very efficient for the screening of polymyxin-resistant isolates once an inappropriate sensitivity is achieved. The results presented here show the need for confirmation of the susceptibility profile by use of a dilution method (Etest or BMD).

Antifungal susceptibility in vitro determined by the Etest® 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® methodology. Candida was isolated from saliva and presumptively identified by CHROMagar Candida(r), confirmed by morphological criteria, carbohydrate assimilation (API 20C AUX®) 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® 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.

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.