¿Es útil la estratificación de la sensibilidad antibiótica de los patógenos urinarios en el Servicio de Urgencias? / Is stratification of antibiotic susceptibility of urinary pathogens useful in the Emergency Department?

OBJETIVO: Determinar la sensibilidad antibiótica de los patógenos causantes de infección del tracto urinario (ITU) estratificándola en función de datos clínicos y demográficos de los pacientes. MATERIAL Y MÉTODOS: Se analizó sensibilidad antibiótica de las bacterias aisladas en orina de 144 pacientes con ITU escogidos al azar y se estratificó en función del sexo, la edad, el tipo de ITU, el haber padecido o no ITU previa y del tratamiento antibiótico previo. RESULTADOS: Se analizó la sensibilidad global de todas las cepas y de las cepas de E. coli observándose diferencias significativas en función del sexo (fluoroquinolonas), la edad (cefuroxima, ertapenem, gentamicina), el tipo de ITU (cefuroxima, cefotaxima, ertapenem, fluoroquinolonas), el haber tenido ITU previa y antibioterapia previa (cefotaxima, fluoroquinolonas, fosfomicina). CONCLUSIONES: El empleo de datos clínicos y demográficos adaptados a la población y a la epidemiología local de resistencia de los uropatógenos, podría ayudar a la elección del tratamiento empírico de la ITU

OBJECTIVE: The aim of the study wat to analyze the antibiotic susceptibility of the pathogens causing urinary tract infection (UTI) and to stratify the results in function of patient's clinical and demographic dates. MATERIAL AND METHODS: The susceptibility of the pathogens isolated in the urine of 144 patients with UTI randomly chosen was analyzed. The results were stratified in function of sex, age, type of UTI, previous UTI and previous antibiotic treatment. RESULTS: The susceptibility of the all isolates and of the Escherichia coli isolates was analyzed. There were significant differences between groups in function of sex (fluoroquinolones), age (cefuroxime, ertapenem and gentamicin), type of UTI (cefuroxime, cefotaxime, ertapenem and fluoroquinolones), previous UTI and previous antibiotic treatment (cefotaxime, fluoroquinolones and fosfomycin). CONCLUSIONS: The use of clinical and demographic data according to population and local resistance epidemiology of the pathogen causing UTI may help to select an adequate empirical treatment for UTI

Antibiotic susceptibility profile of bacilli isolated from the skin of healthy humans

Abstract In the present work, twelve bacilli were isolated from four different regions of human skin from Bela population of Nagpur district, India. The isolated bacilli were identified by their morphological, cultural and biochemical characteristics. Seven isolates were Gram negative rods, out of which five were belong to genus Pseudomonas. Three among the five Gram positive isolates were identified as Dermabactor and the remaining two Bacillus. Their antimicrobial susceptibility profile was determined by Kirby-Bauer disc diffusion method. The isolates showed resistance to several currently used broad-spectrum antibiotics. The Dermabactor genus was resistant to vancomycin, although it was earlier reported to be susceptible. Imipenem was found to be the most effective antibiotic for Pseudomonas while nalidixic acid, ampicillin and tetracycline were ineffective. Isolates of Bacillus displayed resistance to the extended spectrum antibiotics cephalosporin and ceftazidime. Imipenem, carbenicillin and ticarcillin were found to be the most effective antibiotics as all the investigated isolates were susceptible to them. Antibiotic resistance may be due to the overuse or misuse of antibiotics during the treatment, or following constant exposure to antibiotic-containing cosmetic formulations.

Detection of drug resistance in Mycobacterium tuberculosis: Methods, principles and applications.

The growing emergence of multidrug resistant tuberculosis (MDR-TB) strains is obstructing efforts for the control and management of TB. Proper management of MDR-TB relies on early recognition of drug resistance followed by timely treatment initiation. Several diagnostic methods, both phenotypic and molecular, have been developed in last few years for rapid identification of drug resistant (DR)-TB. Revised national tuberculosis control programmes (RNTPs) may find it tough to choose from the puzzling variety of rapid tests. Here, we present an outline of the available methods, discussing their basis, advantages and deficiencies.

Susceptibility testing of the polymyxins: where are we now?

Antimicrobial susceptibility testing for the polymyxins-colistin and polymyxin B-is fraught with technical challenges. Key among these is the propensity of the polymyxins to adsorb to polystyrene, a material often used for in vitro minimum inhibitory concentration testing devices. This effect may be mitigated by the addition of a surfactant such as polysorbate 80; however, concern exists that polysorbate 80 may act synergistically with the polymyxins and artificially lower minimum inhibitory concentrations. Furthermore, the polymyxins diffuse poorly through agar, compromising the performance of both disk diffusion and Etest methods. Very few peer-reviewed studies have investigated in vitro susceptibility test methods for the polymyxins, and it is clear that an in vitro test that reliably predicts the activity of the polymyxins in vivo has yet to be defined. This review describes the methods available and challenges associated with susceptibility testing of colistin and polymyxin B and discusses the current breakpoints for both agents.

Susceptibilidad antibiótica in vitro a fluoroquinolonas / In vitro antibiotic susceptibility to fluoroquinolones

Objetivo: Determinar la susceptibilidad antibiótica de la bacterias obtenidas en cultivos de infecciones oculares en la Fundación Oftalmológica de Santander - Clínica Carlos Ardila Lulle (FOSCAL). Materiales y métodos: Estudio descriptivo retrospectivo de una serie de registros de cultivos de muestras de superficie ocular y líquidos intraoculares del laboratorio OCULAB-FOSCAL en Floridablanca (Colombia) realizados entre enero y diciembre de 2007. Se realizó antibiograma por el método de Kirby-Bauer con sensi-discos impregnados de concentraciones determinadas de antibiótico. Resultados: Se recogieron un total de 352 muestras de los cuales 160 fueron de conjuntiva, 150 fueron de córnea y 42 de líquidos intraoculares. Se recuperó más de un microorganismo en el 45,65% del total de las muestras. El 78,7 y el 18,4% de las bacterias identificadas correspondieron a Gram positivos y a Gram negativos, respectivamente. El 6,3, 8,9, 33,2 y 35,6% de las bacterias Gram positivas fueron resistentes a gatifloxacino, moxifloxacino, ciprofloxacino y levofloxacino, respectivamente. El 7,4, 16,7, 16,7 y 25,9% de las bacterias Gram negativas fueron resistentes a gatifloxacino, moxifloxacino, ciprofloxacino y levofloxacino, respectivamente. La resistencia bacteriana global (tanto Gram positivos como Gram negativos) a moxifloxacino fue del 10,15% y a gatifloxacino del 6,46%, siendo esta diferencia estadísticamente significativa (p<0,05)(AU)

Conclusiones: En nuestro estudio, se evidenció el desarrollo de resistencia bacteriana en muestras oculares incluso con las fluoroquinolonas de cuarta generación. Sin embargo se encontraron menores niveles de resistencia para las fluoroquinolonas de cuarta generación que para las de tercera y segunda generación, especialmente entre Gram positivos. Gatifloxacino mostró menores niveles de resistencia que la moxifloxacino. La interpretación de esta superioridad debe, sin embargo, hacerse con cuidado en el campo clínico, ya que se deben tener en cuenta otros factores como la penetración tisular y la actividad in vivo(AU)

Objective: To determine the antibiotic susceptibility of bacteria recovered from cultures of ocular infections in the Fundación Oftalmológica de Santander - Clínica Carlos Ardila Lulle (FOSCAL). Materials and methods: Retrospective descriptive study of a series of registries of cultures of samples from ocular surfaces and intraocular fluids from the OCULAB-FOSCAL laboratory in Floridablanca (Colombia) made between January and December of 2007. Antibiotic sensitivity screening by the method of Kirby-Bauer with impregnated Sensi-Discs™ of determined antibiotic concentrations was performed. Results: A total of 352 samples were studied: 160 from conjunctiva, 150 from cornea and 42 from intraocular fluids. Of the total of the samples more than one microorganism was recovered 45.65% of the samples. Gram positive and Gram negative bacteria were identified in 78.7 and 18.4%, respectively. Resistance to gatifloxacin, moxifloxacin, ciprofloxacin and levofloxacin was observed in 6.3, 8.9, 33.2 and 35.6%, respectively, of Gram positive bacteria. Resistance to gatifloxacin, moxifloxacin, ciprofloxacin and levofloxacin was also observed in 7.4, 16.7, 16.7%and 25.9%, respectively, of Gram negative bacteria. The overall bacterial resistance (Gram positive and Gram negative) to moxifloxacin was 10.15%, and to gatifloxacin it was 6.46%, being which showed a statistically significant difference (P<.05). Conclusions: In our study the development of bacterial resistance to fourth generation fluoroquinolones was demonstrated in ocular samples. However, lower levels of resistance to fourth generation fluoroquinolones compared with that of third and second generation were found, particularly to Gram positive. Gatifloxacin showed lower resistance levels than moxifloxacin. Nevertheless, interpretation of this superiority must be made with caution in the clinical field, since other factors, like tissue penetration and in vivo activity, must be taken into account(AU)

[Comparison of disc diffusion, E-test, and broth microdilution methods for the determination of resistance to colistin, polymyxin B, and tigecycline in multi-resistant Acinetobacter baumannii isolates]. / Cogul dirençli Acinetobacter baumannii izolatlarinda kolistin, polimiksin B ve tigesiklin direncinin saptanmasinda disk difüzyon, E-test ve buyyon mikrodilüsyon yöntemlerinin karslastirilmasi.

The increased rate of antimicrobial resistance in Acinetobacter baumannii made it necessary to reconsider old antibiotics such as polymyxins and develop new drugs such as tigecycline. The aim of this study was to investigate the susceptibility rates of multi-drug resistant A. baumannii clinical isolates to colistin, polymyxin B, and tigecycline by three different methods in microbiology laboratory of Gaziantep University Research Hospital, between September 2006 and April 2008. A total of 200 A. boumannii strains isolated from various clinical samples (tracheal aspirate, blood, sputum, surgical wound, catheter, pleural fluid, urine, and others) were included to the study. Identification of bacteria was performed by conventional microbiological methods and by an automatized identification system (Vitek 2, bioMerieux, France). Antimicrobial susceptibility pattern of A. baumannii isolates was determined by disc diffusion method and 95 multiple resistant A. baumannii isolates were identified. Susceptibilities of these multiple resistant bacteria to colistin, polymyxin B, and tigecycline were tested with disc diffusion, E-test, and broth microdilution methods. All of the isolates (100%) were sensitive to colistin with all three methods. Ninety-two (96.8%) of them were sensitive to polymyxin B with both disc diffusion and broth microdilution methods, and 90 (94.7%) of them were sensitive to polymyxin B with E-test. Eighty-three (87.4%) of them were sensitive to tigecycline by disc diffusion method, 78 (82.1%) by E-test, and 90 (94.7%) by broth microdilution method. No statistically significant difference was detected for the three methods in terms of susceptibility testing for polymyxin B (p > 0.05). However, while no significant difference wa detected for tigecycline susceptibility testing by disk diffusion and broth microdilution (p > 0.05), statistically significant difference was determined for broth microdilution and E-test methods (p = 0.000). In conclusion, comparison of disc diffusion, E-test, and broth microdilution methods yielded that all three methods were concordant to each other in terms of susceptibility testing of polymyxins. Susceptibility rate to tigecycline was found lower by E-test method than that obtained by other methods. These results emphasized that antimicrobial activities of colistin, polymyxin B and tigecycline against A. baumannii isolates obtained in our hospital were high, however, for tigecycline susceptibility testing against A. boumannii, disk diffusion or broth microdilution methods would rather be preferred.

Comparación entre el sistema Phoenix y métodos basados en agar para el ensayo de sensibilidad a antibióticos en Streptococcus spp / Comparison between Phoenix system and agar-based methods for antimicrobial susceptibility testing of Streptococcus spp

Introducción. La resistencia a los antibióticos en el grupode los estreptococos es un problema emergente de especialimportancia en las infecciones graves. El sistema automatizadoBD Phoenix para identificación y antibiograma esun instrumento diagnóstico recientemente disponible quepermite obtener resultados en 12 h.Métodos. Se ha llevado a cabo un estudio comparativoentre el sistema BD Phoenix con paneles SMIC/ID-9 y el métododisco-difusión para la realización de estudios de sensibilidada antibióticos. Se utilizaron 200 aislamientos clínicosde estreptococos: betahemolíticos (n=65), viridans (n=87) yStreptococcus pneumoniae (n=48).Resultados. De forma global, en relación con el métododisco-difusión, hubo un acuerdo entre categorías superioral 96,7% (94,8% en betahemolíticos y 97,9% en viridans).Las tasas de errores menores fueron inferiores al 10% paratodos los antibióticos. El mayor porcentaje de errores gravescorrespondió a eritromicina y clindamicina dentro del grupode los betahemolíticos (14,7 %). El porcentaje global deerrores muy graves fue inferior al 0,5%. Los resultados parapenicilina en estreptococos viridans y S. pneumoniae presentaronun acuerdo entre categorías del 89,7 y 91,7% frentea Etest, respectivamente.Conclusiones. El sistema automatizado BD Phoenix esun instrumento diagnóstico de gran utilidad y efectividadpara el ensayo cuantitativo de la sensibilidad a los antibióticosen el grupo de los estreptococos (AU)

Introduction. Antibiotic resistance is an emergingproblem among streptococcal species, especially for severeinfections. Automated diagnostic systems for antimicrobialsusceptibility testing, such as BD Phoenix, is arecently available instruments that makes it possible toobtain results within 12 h.Methods. Antimicrobial susceptibility testing resultsof the BD Phoenix system were compared to those obtainedfrom Clinical Laboratory Standards Institute (CLSI)disk-diffusion method. Two-hundred different clinicalisolates of streptococci were assayed: beta-hemolytic(n=65), viridans (n=87), S. penumoniae (n=48).Results. Overall, there was categorical agreement greaterthan 96.7% (94.8% for beta-hemolytic and 97.9% for viridansgroup) in relationship to the disk-diffusion method.The minor error rates were less than 10% for all the antibiotics.The greatest percentage of serious errors correspondedto erythromycin and clindamycin within the beta-hemolyticgroup (14.7%). Overall percentage of very serious errors wasless 0.5%. The results for penicillin in viridans streptococciand S. pneumoniae results showed 89.7% and 91.7% of categoricalagreement, respectively, using the Etest as reference.Conclusions. The automated BD Phoenix system is avery useful and effective diagnostic tool for quantitativetesting of sensitivity to antibiotics in the streptococci group (AU)

Antibacterial activity of zinc modified titanium oxide surface.

Titanium-based implants are successfully used for various biomedical applications. However, in some cases, e.g. in dental implants, failures due to bacterial colonization are reported. Surface modification is a commonly proposed strategy to prevent infections. In this work, titanium oxide, naturally occurring on the surface of titanium, was modified by promoting the formation of a mixed titanium and zinc oxide, on the basis of the idea that zinc oxide on titanium surface may act as the zinc oxide used in pharmaceutical formulation for its lenitive and antibacterial effects. The present work shows that it is possible to form a mixed titanium and zinc oxide on titanium surfaces, as shown by Scanning Electron Microscopy and XPS analysis. To this end titanium was preactivated by UV on crystalline titanium oxide, both in the anatase form or in the co-presence of anatase and rutile. By performing antibacterial assays, we provide evidence of a significant reduction in the viability of five streptococcal oral strains on titanium oxide surfaces modified with zinc. In conclusion, this type of chemical modification of titanium oxide surfaces with zinc might be considered a new way to reduce the risk of bacterial colonization, increasing the lifetime of dental system applications.

Etiología y resistencia bacteriana de las infecciones urinarias extrahospitalarias del norte de Tenerife / Etiology and antibacterial resistances of urinary infection of outpatients in north of Tenerife

Objectivo. Conocer los microorganismos causantes de las infecciones urinarias extrahospitalarias y sus resistencias antimicrobianas en nuestra área para facilitar el tratamiento antibiótico de forma empírica. Diseño. Se describen las infecciones del tracto urinario (ITU) identificadas a partir de la revisión sistemática de los resultados de urianálisis y urocultivo realizados en nuestro laboratorio. Pacientes y métodos. Urocultivos solicitados y remitidos a nuestro laboratorio entre los meses de abril a noviembre de 2003. Se identificó el tipo de germen y la sensibilidad antibiótica. Se analizaron un total de 4.874 urocultivos, de los cuales 1.310 (27 por ciento) fueron positivos. El germen más prevalente fue E. coli (48 por ciento) con mayor sensibilidad a fosfomicina, nitrofurantoína y amoxicilinaclavulánico, seguido de E. faecalis (14 por ciento), P. mirabilis (4 por ciento) y K. pneumoniae (3 por ciento). Conclusiones. E. coli fue el germen más frecuentemente aislado. Considerando una tasa de resistencia inferior al 20 por ciento para el empleo empírico de antibióticos en las ITU no complicadas, no se recomienda el uso de ampicilina, cotrimoxazol y quinolonas. En nuestro medio, los antibióticos de elección para el tratamiento de ITU serían amoxicilina-clavulánico y cefalosporinas de primera generación (AU)

European survey on Campylobacter surveillance and diagnosis 2001.

Two surveys have been conducted on behalf of the Campylobacter Working Group with the aim of assessing the feasibility of a European network on human Campylobacter infections. The first survey, conducted in 18 countries, collected information about diagnostic methods used for surveillance purpose while the second one, conducted among 10 European countries, gathered data on diagnostic methods and procedures in primary laboratories. Seventeen of the 18 countries had a surveillance system for Campylobacter infections and 13 a national reference laboratory. The case definition used for the surveillance in all these countries included laboratory confirmation. No commonly applicable subtyping methods were applied. Concerning primary laboratories dealing with Campylobacter infections, only a few of them reported directly to the national level, and antimicrobial susceptibility testing was performed by about half of the laboratories. These surveys indicated that a basic infrastructure for a wide European Campylobacter surveillance exists.

Clinical features and antimicrobial susceptibility trends in Citrobacter freundii bacteremia.

This retrospective study investigated the clinical characteristics and antimicrobial susceptibilities of 36 cases of Citrobacter freundii bacteremia treated at the Taipei Veterans General Hospital from 1996 through 1999. The results showed that the predominant infection site was the intraabdominal region and the mortality was 22%. The resistance of C. freundii to most third-generation cephalosporins and broad-spectrum penicillins increased in both nosocomial and community-acquired C. freundii bacteremia during the study period, and the strategy of using a combination of antimicrobial agents to treat C. freundii infection was effective. This study also demonstrated the importance of appropriate antimicrobial therapy to the successful outcome of C. freundii bacteremia. The guidelines of the National Nosocomial Infections Surveillance System were followed to determine trends of resistance of C. freundii to various antimicrobial agents. The resistance of C. freundii to antibiotics in 1999 (n = 10), compared with the period from 1996 through 1998 (n = 26), increased 66% for ciprofloxacin, 36% for ticarcillin/clavulanate, 70% for piperacillin/tazobactam, and 62.8% for piperacillin, but remained uniformly susceptible to imipenem/cilastatin and the new fluoroquinolone (levofloxacin). This increase in resistance was attributable to the use of third-generation cephalosporin instead of first-generation cephalosporins. These findings indicate the need for new measures to facilitate the appropriate choice of antimicrobial agents for patients with C. freundii bacteremia.

Serovars and multiple drug resistant Salmonella sp. isolated from children in Rio de Janeiro-Brazil

Foram caracterizadas sorologicamente e testadas para a susceptibilidade e antimicrobianos, 116 amostras de Salmonella isoladas de coproculturas e hemoculturas efetuadas de crianças durante o período de maio de 1987-junho 1992 no Instituto Fernando Figueira, Brasil. Detectou-se seis sorogrupos (04; 07; 08; 09; 03; 10 e 035) representados por 18 serovares, sendo a S. typhimurium (62,93 por cento) a mais frequente, seguida da S. agona (7,75 por cento). Os antimicrobianos utilizados foram a ampicilina (Ap), cefalotina (Cf), cefoxitina (Cx), ceftriaxona (Cro), pefloxacin (Pf), gentamicina (Ge), amicacina (Am), sulfametoxazoletrimetropim (SxT), cloranfenicol (CL) e tetraciclina (Te). 94.52 por cento das cepas de S. typhimurium representaram determinantes de resistência. Foram encontrados 29 padröes de resistência diferentes, sendo o mais frequente para S. typhimurium o Ap, Cf, Ge, Am, Sxt, Cl, Te, Pf (40,47 por cento) e para os outros serovares o Te (20.83 por cento). A determinaçäo da concentraçäo mínima inibitória realizada para cinco dos antimicrobianos citados evidenciou altos níveis de resistência para Ap e Cl, contrapondo-se a níveis mais baixos obtidos para Ge, Sxt e Cro

Penicilin resistant Streptococcus pneumoniae from patients with meningitis

Avaliou-se a susceptibilidade a antibióticos em 146 cepas de Streptococcus pneumoniae isoladas de líquido cerebroespinhal. Sete cepas (3 com o fenótipo de resistência e 4 com o fenótipo de susceptibilidade moderada) apresentaram resultados semelhantes para a oxacilina segundo o método da difusäo em disco, e para a penicilina segundo o método da concentraçäo mínima inibitória. Duas cepas tiveram comportamentos discrepantes ao comparar-se os resultados de 2 métodos. Todas as outras cepas (137) apresentaram inibiçäo de crescimento para uma concentraçäo de oxacilina de 1 mg/ml, segundo o método da difusäo em disco

Bacteremias en un hospital de cáncer. experiencia entre 1980 y 1993 en el INEN / Bacteremia at cancer hospital between 1980 and 1993

Con el objeto de evaluar la distribución epidemiológica de las bacteremias detectadas en el INEN entre 1980 y 1993 revisamos los archivos de la institución. Los gérmenes Gram positivos representan aproximadamente el 60 por ciento de la serie. Entre 1980 a 1984 el S. aureus fue el Gram positivo más frecuente y S. epidermidis entre 1985 y 1993. Los gérmenes negativos representaron el 40 por ciento del total y cinco fueron los más frecuentes: Pseudomona, E. coli, Klebsiella, Acinetobacter y Enterobacter.

Necesidad del uso del Antibiograma en el tratamiento Antituberculoso

1.-Es necesario el conocimiento de la sensibilidad del germen para el tratamiento, 2.-Se constata que algunas resitencias son resultado de mala dosificacion de las drogas(dosis minimas tratatamientos intermitentes esquemas terapeuticos no adecuados). 3.-Conociendo la sensibilidad del germen a los diferentes quimio-farmacos tanto en tratamiento como el periodo de internacion son mas cortos, 4.-Por falta de control de la sensibilidad del germen se prologa el periodo de internación y la evolución de la enfermedad con el consiguiente derroche de recursos economicos no solo en el mantemimiento sino tambien en la adquisisición de drogas, 5.-El porcentaje más alto de resitencias en los casos expuestos está dado por la Estreptomicina en primer lugar luego por el PAS y en orden de menor frecuencia la INH y el Myambutol

Determinación cuantitativa de la actividad de los agentes antimicrobianos CIM / Quantitative determination of the activity of the antimicrobial agents CIM

El documento ofrece el III Curso Latinoamericano de Actualización en Antimicrobianos realizado en Managua del 13 al 15 de junio del 2000. En el que aborda el tema sobre la determinación cuantitativa de la actividad de los agentes antimicrobianos (CIM), así como la cinetica de la actividad antimicrobiana, los casos en que se debe realizar una prueba cuantitativa (CIM), ,los métodos para la determinación cuantitativa de la sensibilidad a los antimicrobianos, los factores que afectan los resultados de las pruebas de sensibilidad por dilución, los criterios para establecer puntos de corte farmacocinetica y farmacodinamica de las drogas, asi como los criterios para establecer puntos de corte y las recomendaciones para evaluar la sensibilidad de microorganismos inusuales, los mecanismos de resistrencia a antibióticos Betalactamicosn en Haemophilus SPP