Detection of beta-lactamase-producing Enterobacteriaceae in a veterinary hospital environment / Detecção de Enterobactérias produtoras de beta-lactamases em ambiente hospitalar veterinário

Due to the strong selective pressure resulting from the misuse of antibiotics, the natural process of bacterial resistance has been accelerated, leading to the increasingly constant appearance of multiresistant isolates. The high number of multi-resistant bacteria is a one health problem. Enterobacteriaceae are usually commensal bacteria of the gastrointestinal tract. However, they can cause infections, and the most important resistance characteristic among them is the production of ß-lactamases. This study aimed to identify ESBL-producing Enterobacteriaceae of types of TEM, SHV, and the CTX-Mgroups. To isolate the enterobacteria, swabs were collected by swiping objects that had contact with the patients and professionals, and the water of the hospital environment. Ten collections were carried out, yielding 306 samples, from which 118 enterobacteria were identified: Escherichia coli, Enterobacter spp., Klebsiella spp., Proteus mirabilis, Serratiaspp., and Citrobacter spp. Isolates. The genes TEM and CTX-M, for the production of ß-lactamases, were detected in 12.7% of the 118 enterobacterial isolates. It is very important to know the bacterial population circulating in the veterinary hospital environment and its resistance to antimicrobials so that professionals can take appropriate measures to minimize the risks of transmission, especially from cages and consultation tables. In addition, the correct control of the microbiological quality of the supply water, as well as environmental cleaning procedures, are essential to prevent the transmission of these microorganisms.(AU)

Devido à grande pressão seletiva decorrente do uso indevido de antibióticos, tem se acelerado o processo natural de resistência das bactérias, levando ao aparecimento cada vez mais constante de isolados multirresistentes. O elevado número de bactérias multirresistentes identificadas é um problema da saúde única. As enterobactérias são bactérias geralmente comensais do trato gastrointestinal, entretanto podem causar infecções, e a característica de resistência mais importante entre elas é a produção de ß-lactamases. Buscando caracterizar melhor os microrganismos circulantes e potencialmente causadores de infecções em ambiente hospitalar veterinário, este estudo objetivou identificar as enterobactérias produtoras de ESBL do tipo TEM, SHV e os cinco grupos de CTX-M presentes em isolados circulantes em hospital veterinário. Foi realizada coleta de suabes de arrasto de objetos que entram em contato com os pacientes e com os profissionais que ali trabalham, bem como de água, para a identificação das enterobactérias. Foram realizadas 10 coletas, obtendo-se 306 amostras, dessas, 118 enterobactérias foram identificadas: Escherichia coli, Enterobacter, Klebsiella, Proteus mirabilis, Serratia e Citrobacter. Dentre as enterobactérias identificadas, alguns isolados possuíam genes para a produção de ß-lactamases, do tipo TEM e CTX-M. É de grande importância conhecer a população bacteriana circulante no ambiente hospitalar veterinário, e a sua resistência aos antimicrobianos, para que os profissionais possam tomar medidas apropriadas para minimizar os riscos de transmissão, principalmente a partir de gaiolas e mesas de atendimento. Além disso, o correto controle da qualidade microbiológica da água de abastecimento, bem como dos procedimentos de higienização do ambiente, são fundamentais para evitar a transmissão destes microrganismos.(AU)

Detection of efflux pump CmeABC in enrofloxacin resistant Campylobacter spp. strains isolated from broiler chickens (Gallus gallus domesticus) in the state of Rio de Janeiro, Brazil / Detecção da bomba de efluxo CmeABC em cepas de Campylobacter spp. resistentes à enrofloxacina isoladas de frangos de corte (Gallus gallus domesticus) no Estado do Rio de Janeiro, Brasil

Fowls are the main reservoirs of the highly important food-originating pathogen called Campylobacter spp. and broilers' meat and byproducts are the main vehicles of this microorganism. Increasing of Campylobacter spp. resistant strains to fluorquinolones, an antimicrobial class often employed in poultry farming and in human medicine has become a great concern to poultry breeders. In fact, several studies evaluated increasing bacterial resistance against these antimicrobial agents. The role of CmeABC efflux system has been underscored among the resistance mechanisms in Campylobacter spp. to fluorquinolones. This study investigated the occurrence of CmeABC efflux pump in 81 and 78 enrofloxacin resistant strains of Campylobacter jejuni and C. coli respectively, isolated from broilers collected from six abattoirs situated at São José do Vale do Rio Preto/RJ poultry center and from two commercial abattoirs situated at Metropolitan Region of Rio de Janeiro, from 2013 to 2016. The resistance to enrofloxacin was assessed by agar dilution to determine minimum inhibitory concentration (MIC). The CmeABC efflux system was investigated through the detection of genes genes cmeA, cmeB and cmeC by PCR. The activity of CmeABC efflux pump was investigated in 20 strains by using the efflux pump inhibitor Phenylalanine-Arginine ß-Naphthylamide (PAßN). The three genes cmeA, cmeB and cmeC were detected in 94.3% of the strains (C. jejuni = 80 and C. coli = 70), whereas the system was absent or incomplete in 5.7% of strains (C. jejuni = 1 and C. coli = 8). MIC varied between 0.5µg/ml and 64µg/ml, and 88.7% of strains were enrofloxacin resistant and 11.3% featuring intermediate resistance. The inhibition of the efflux pump by PAßN reduced the MIC to enrofloxacin up to eight times in fifteen strains (75%). These results indicate that this system is frequent and active in Campylobacter spp. Resistant strains in the presence of enrofloxacin.(AU)

As aves são os principais reservatórios de Campylobacter spp., importante patógeno de origem alimentar e a carne de frango e produtos derivados são os principais veículos desse microrganismo. O aumento de cepas de Campylobacter spp. resistentes às fluorquinolonas, uma classe antimicrobiana frequentemente empregada na avicultura e na medicina humana, tornou-se uma grande preocupação para os produtores de aves e vários estudos avaliaram o aumento da resistência bacteriana a esses antimicrobianos. O papel do sistema de efluxo CmeABC tem sido enfatizado entre os mecanismos de resistência em Campylobacter spp. à fluorquinolonas. O presente estudo investigou a ocorrência da bomba de efluxo CmeABC em 81 cepas de Campylobacter jejuni e 78 cepas de Campylobacter coli resistentes à enrofloxacina, isoladas de frangos de corte coletados em seis abatedouros situados no polo avícola de São José do Rio Preto/RJ e de dois abatedouros comerciais situados na Região Metropolitana do Rio de Janeiro, de 2013 a 2016. A resistência à enrofloxacina foi avaliada pelo método de diluição em ágar para determinar a concentração inibitória mínima (CIM). O sistema de efluxo CmeABC foi investigado através da detecção dos genes cmeA, cmeB e cmeC por PCR. A atividade da bomba de efluxo CmeABC foi investigada em 20 cepas utilizando o inibidor da bomba de efluxo Phenylalanine-Arginine ß-Naftilamida (PAßN). Os três genes cmeA, cmeB e cmeC foram detectados em 94,3% das cepas (C. jejuni = 80 e C. coli = 70), enquanto o sistema estava ausente ou incompleto em 5,7% das cepas (C. jejuni = 1 e C coli = 8). A CIM variou entre 0,5µg/ml e 64µg/ml e 88,7% das cepas foram resistentes à enrofloxacina, enquanto 11,3% apresentaram resistência intermediária. A inibição da bomba de efluxo pelo PAßN reduziu a CIM da enrofloxacina até oito vezes em quinze cepas (75%). Estes resultados indicam que este sistema é frequente e ativo em cepas resistentes de Campylobacter spp. na presença de enrofloxacina.(AU)

Implicancias estructurales y fisiológicas de la célula bacteriana en los mecanismos de resistencia antibiótica / Structural and physiological implications of bacterial cell in antibiotic resistance mechanisms

RESUMEN: La alta capacidad de adaptación de las bacterias a ambientes hostiles ha permitido el desarrollo de resistencia a antibacterianos, causando problemas de impacto mundial en la salud hospitalaria y de la comunidad, limitando las opciones terapéuticas lo que afecta el control de enfermedades, elevando las tasas de morbi-mortalidad. Esta capacidad de resistencia es mediada por factores estructurales y fisiológicos de las bacterias que actúan a diferentes niveles tanto extracelular como intracelular. A niveles extracelulares se destaca la capacidad de las poblaciones bacterianas en la formación de biopelículas y la regulación de señales celulares quorum sensing, permitiendo la evasión de la acción antibiótica. A nivel de envoltura celular se destaca el funcionamiento y comportamiento de la pared celular y de la membrana celular, principalmente por medio de la regulación de la expresión de canales de entrada o porinas y/ o bombas de expulsión que impiden el acceso o inducen la salida de antibióticos; otros mecanismos integran la modificación de la actividad de drogas por medio de la hidrólisis o modificación del sitio activo del fármaco. A nivel intracelular, las bacterias pueden cambiar los procesos de óxido/reducción, modificar los sitios objetivos del antibiótico e inactivar los grupos transfer, y modificar las subunidades ribosomales afectando la acción de los antibióticos que inhiben la síntesis de proteínas. A esto se añaden las modificaciones en la expresión génica y del código genético, que regula todos los anteriores, y es capaz de generar cambios adaptativos, resistencia a fármacos y desinfectantes, entre otros. La presente revisión tiene como objetivo describir las implicancias estructurales y fisiológicas de la célula bacteriana en los mecanismos de resistencia antibiótica considerando la organización estructural y fisiológica involucrada en los principales mecanismos de resistencia a antibióticos presentes en bacterias de importancia clínica que conllevan a fallas terapéuticas con alto costo en salud humana.

SUMMARY: The high adaptability of bacteria to hostile environments has favored antibacterial resistance development, impacting hospital and community healthcare worldwide. It has also affected disease control, limited therapeutic options and raised morbiditymortality rate. This resistance ability is mediated by structural and physiological factors of bacteria acting at both extracellular and cellular levels. The ability of bacterial populations in biofilm formation and regulation of cellular signal quorum sensing at the extracellular level, allows for the evasion of antibiotic action. At a cellular level, the performance and behavior of the cell wall and cell membrane is emphasized, mainly by regulating the expression of inlet channels or porins and/or expulsion pumps preventing access to, or inducing the outflow of antibiotics. Other mechanisms integrate modification of drug activity by hydrolysis or modification of the active site of the drug. Further into intracellular level, bacteria can change the oxidation/reduction processes; modify the target sites of the antibiotic and inactivate transfer groups. Bacteria can also modify the ribosomal subunits affecting the antibiotics which inhibit protein synthesis, and cause modifications of gene expression and genetic code that regulate the above mechanism. These may also generate adaptive changes and resistance to drugs and disinfectants. The aim of the present review is to describe the structural and physiological implications of bacterial cell in the mechanisms of antibiotic resistance. The study also considered the structural and physiological organization involved in the main mechanisms of antibiotic resistance in bacteria relevant to clinical healthcare.

Habituation of enterotoxigenic Staphylococcus aureus to Origanum vulgare L. essential oil does not induce direct-tolerance and cross-tolerance to salts and organic acids

Enterotoxigenic Staphylococcus aureus strains that were isolated from foods were investigated for their ability to develop direct-tolerance and cross-tolerance to sodium chloride (NaCl), potassium chloride (KCl), lactic acid (LA) and acetic acid (AA) after habituation in sublethal amounts (1/2 of the minimum inhibitory concentration - 1/2 MIC and 1/4 of the minimum inhibitory concentration - 1/4 MIC) of Origanum vulgare L. essential oil (OVEO). The habituation of S. aureus to 1/2 MIC and 1/4 MIC of OVEO did not induce direct-tolerance or cross-tolerance in the tested strains, as assessed by modulation of MIC values. Otherwise, exposing the strains to OVEO at sublethal concentrations maintained or increased the sensitivity of the cells to the tested stressing agents because the MIC values of OVEO, NaCl, KCl, LA and AA against the cells that were previously habituated to OVEO remained the same or decreased when compared with non-habituated cells. These data indicate that OVEO does not have an inductive effect on the acquisition of direct-tolerance or cross-tolerance in the tested enterotoxigenic strains of S. aureus to antimicrobial agents that are typically used in food preservation.

Mechanisms of action of systemic antibiotics used in periodontal treatment and mechanisms of bacterial resistance to these drugs

Antibiotics are important adjuncts in the treatment of infectious diseases, including periodontitis. The most severe criticisms to the indiscriminate use of these drugs are their side effects and, especially, the development of bacterial resistance. The knowledge of the biological mechanisms involved with the antibiotic usage would help the medical and dental communities to overcome these two problems. Therefore, the aim of this manuscript was to review the mechanisms of action of the antibiotics most commonly used in the periodontal treatment (i.e. penicillin, tetracycline, macrolide and metronidazole) and the main mechanisms of bacterial resistance to these drugs. Antimicrobial resistance can be classified into three groups: intrinsic, mutational and acquired. Penicillin, tetracycline and erythromycin are broad-spectrum drugs, effective against gram-positive and gram-negative microorganisms. Bacterial resistance to penicillin may occur due to diminished permeability of the bacterial cell to the antibiotic; alteration of the penicillin-binding proteins, or production of β-lactamases. However, a very small proportion of the subgingival microbiota is resistant to penicillins. Bacteria become resistant to tetracyclines or macrolides by limiting their access to the cell, by altering the ribosome in order to prevent effective binding of the drug, or by producing tetracycline/macrolide-inactivating enzymes. Periodontal pathogens may become resistant to these drugs. Finally, metronidazole can be considered a prodrug in the sense that it requires metabolic activation by strict anaerobe microorganisms. Acquired resistance to this drug has rarely been reported. Due to these low rates of resistance and to its high activity against the gram-negative anaerobic bacterial species, metronidazole is a promising drug for treating periodontal infections.

High prevalence rate of extended-spectrum beta-lactamases (ESBL) among Enterobacteriaceae in a small Brazilian public hospital

The production of extended-spectrum beta-lactamases (ESBL) is considered one of the most important resistance mechanisms that impair antimicrobial treatment of infections caused by Enterobacteriaceae. Data on culture and susceptibility tests were collected from the Clinical Analyses and Research Laboratory charts reporting on patients admitted to the University Hospital of Maringá (HUM) from January 2004 to December 2009. The following Enterobacteriaceae were selected: Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter spp. and Proteus mirabilis. All tests were performed according to the recommendations of the Clinical and Laboratory Standards Institute (biochemical identification; susceptibility tests; initial screening and phenotypic confirmatory tests for ESBL). For Enterobacter spp. isolates, a disk approximation test was carried out, adding a cefepime disk. Seven hundred samples were analyzed, and E. coli was the most prevalent bacteria (n= 356). ESBLs were detected phenotypically in 7.3 percent of E. coli, 61.7 percent of K. pneumoniae, 33.3 percent of K. oxytoca, 7.1 percent of P. mirabilis, and 13.4 percent of Enterobacter spp samples. Overall ESBL prevalence reached 22 percent when all producers were taken together. Although HUM is considered a small-sized hospital, it showed high levels of resistance to antimicrobial agents, similar to those observed in bigger hospitals, which demonstrated the need for careful epidemiological surveillance.

A produção de beta-lactamases de espectro ampliado (ESBL) é considerada um dos mais importantes mecanismos de resistência aos antimicrobianos, o que dificulta o tratamento de infecções causadas por enterobactérias. Dados sobre cultura e testes de sensibilidade foram coletados das fichas do Laboratório de Ensino e Pesquisa de Análises Clínicas de pacientes atendidos no Hospital Universitário de Maringá (HUM), de janeiro de 2004 a dezembro de 2009. As enterobactérias escolhidas foram: Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter spp. e Proteus mirabilis. Os testes foram realizados de acordo com as recomendações do CLSI (identificação bioquímica; testes de suscetibilidade; triagem e confirmação fenotípica de produção de ESBL). Para isolados de Enterobacter spp., utilizou-se a técnica de disco aproximação, acrescentando um disco de cefepima. Setecentas amostras foram analisadas e E. coli foi a bactéria mais prevalente (n=356). ESBLs foram detectadas fenotipicamente em 7,3 por cento das amostras de E. coli, 61,7 por cento das de K. pneumoniae, 3,3 por cento das de K. oxytoca, 7,1 por cento das de P. mirabilis e em 13,4 por cento das de Enterobacter spp. A prevalência geral de ESBL chegou a 22 por cento, somando-se todos os isolados produtores. O HUM, mesmo sendo considerado um hospital de pequeno porte, apresenta níveis altos de resistência a antimicrobianos, semelhantes àqueles observados em hospitais maiores, demonstrando a necessidade de cuidadosa vigilância epidemiológica.

Documento de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEIMC) y de la Sociedad Española de Medicina Preventiva, Salud Pública e Higiene (SEMPSPH), para luchar contra las resistencias bacterianas / No disponible

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Resistencia a drogas antituberculosas en Caracas, Venezuela; 2001-2006 / Antituberculosis drug resistance in Caracas, Venezuela; 2001-2006

Para establecer la sensibilidad de las cepas de Mycobac-terium tuberculosis aisladas en Caracas, entre 2001 y 2006, fueron probadas utilizando el método colorimétrico para determinar las Concentraciones Inhibitorias Mínimas (CIM). De las 324 cepas, 46 (14,2%) mostraron resistencia a una o más drogas. Encontramos resistencia de alto nivel (CIM 8 µg/ml) y bajo nivel (CIM 1-4 µg/ml) a Estreptomicina en 6 (1,8%) y 25 (7,7%) de las cepas, respectivamente. Se encontró resistencia a Isoniacida de bajo nivel (MIC 0,125 - 0,5 µg/ml) en 8 (2,5%) y de alto nivel (MIC 1,0 µg/ml) en 15 (4,6%) de las cepas estudiadas. Hallamos 13 (4,0%) cepas resistentes a Rifampicina (RIF) (5 µg/ml) y 11 (3,4%) a Etambutol (10 µg/ml). De los 17 (5,2%) aislamientos resistentes a dos o más drogas, 12 (3,7%) fueron resistentes a INH y RIF (definido como multirresistencia, MDR). De las 12 cepas MDR, 11 fueron aisladas a partir de esputo y una de líquido pleural. Este estudio muestra un incremento en la prevalencia de la resistencia a las drogas antituberculosas en Caracas, especialmente las cepas MDR. Este aumento apunta hacia la necesidad de una encuesta na-cional, para evaluar el panorama real de la resistencia.

To asses drug susceptibility of Mycobacterium tuberculosis strains isolated from 2001 to 2006 in Caracas. Available strains were tested using colorimetric method to determine the Minimal Inhibitory Concentrations (MIC). Of 324 strains, 46 (14,2%) showed resistance to one or more drugs. High-resistance (8 µg/ml) and low-resistance (1-4 µg/ml) to Strep omycint was found in 6 (1,8%) and 25 (7,7%) strains, respectively. Isoniazid (INH) low-resistance (MIC 0.125 - 0.5 µg/ml) were found in 8 (2,5%) and high-resistant (MIC at 1.0 µg/ml) in 15 (4,6%), Rifampicin resistance (RMP) (5 µg/ml) in 13 (4%), and Ethambutol resistance (10 µg/ml) in 11 (3,4%) of the strains. Of the 17 (5,2%) isolates resistant to two or more drugs, 12 (3,7%) were resistant to INH and RMP (defined as multidrug resistance, MDR). Of these 12 MDR strains, 11 were isolated from sputum and one from pleu ral fluid. This study shows an increased prevalence of resistance to anti-tuberculosis drugs in Caracas, especially the prevalence of MDR strains, raises an urgent need of a proper nationwide survey to evaluate the true picture of resistance.

Nuevo horizonte en la lucha contra la resistencia bacteriana / New horizont in the fight against bacterial resistance

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Perfil de resistência de Mycobacterium tuberculosis no estado de Mato Grosso do Sul, 2000-2006 / Drug resistance profile of Mycobacterium tuberculosis in the state of Mato Grosso do Sul, Brazil, 2000-2006

OBJETIVO: Determinar o perfil de resistência a drogas de Mycobacterium tuberculosis no estado de Mato Grosso do Sul no período entre 2000 e 2006. MÉTODOS: Estudo descritivo de casos notificados de tuberculose no Sistema de Informação de Agravos de Notificação, com cultura positiva para M. tuberculosis e testes de sensibilidade a rifampicina, isoniazida, estreptomicina e etambutol. Para as culturas, utilizaram-se os meios sólidos Lõwenstein-Jensen e Ogawa-Kudoh, assim como um sistema automatizado com meio líquido; para os testes de sensibilidade, o método das proporções. RESULTADOS: De 783 casos, 69,7 por cento eram de pacientes masculinos, na faixa etária de 20-49 anos (70 por cento), com forma pulmonar (94,4 por cento) e sorologia positiva para HIV (8,6 por cento); 645 (82,4 por cento) eram casos novos, e 138 (17,6 por cento) eram casos tratados. Identificou-se qualquer resistência em 143 casos (18,3 por cento). A taxa de resistência primária (RP) foi, respectivamente, 8,1 por cento, 1,6 por cento, 2,8 por cento e 12,4 por cento, para monorresistência, multirresistência (MR), outros padrões de associação de drogas e qualquer resistência, ao passo que a taxa de resistência adquirida (RA) foi, respectivamente, 14,5 por cento, 20,3 por cento, 10,9 por cento e 45,7 por cento, e a taxa de resistência combinada (RC) foi, respectivamente, 9,2 por cento, 4,9 por cento, 4,2 por cento e 18,3 por cento. A estreptomicina foi a droga mais comum na RP (3,4 por cento), e a isoniazida foi a mais comum na RA e RC (7,2 por cento e 3,7 por cento, respectivamente). CONCLUSÕES: Os níveis de resistência são elevados, prejudicando o controle da tuberculose em Mato Grosso do Sul. A MR adquirida, 12,7 vezes superior à MR primária, evidencia o uso prévio de medicamentos como indicativo de resistência. Os níveis refletem a fragilidade da atenção ao doente, mostrando a importância do tratamento diretamente observado, assim como das culturas e testes de sensibilidade ...

OBJECTIVE: To determine the drug resistance profile of Mycobacterium tuberculosis in the state of Mato Grosso do Sul, Brazil, between 2000 and 2006. METHODS: Descriptive study of reported tuberculosis cases in the Brazilian Case Registry Database. We included only those cases in which M. tuberculosis culture was positive and sensitivity to drugs (rifampicin, isoniazid, streptomycin and ethambutol) was tested. Lõwenstein-Jensen and Ogawa-Kudoh solid media were used for cultures, as was an automated liquid medium system. Sensitivity tests were based on the proportion method. RESULTS: Among the 783 cases evaluated, males predominated (69.7 percent), as did patients in the 20-49 year age bracket (70 percent), a diagnosis of pulmonary tuberculosis (94.4 percent) and positive HIV serology (8.6 percent); 645 (82.4 percent) were new cases, and 138 (17.6 percent) had previously been treated. Resistance to at least one drug was found in 143 cases (18.3 percent). The primary resistance (PR) rate was, respectively, 8.1 percent, 1.6 percent, 2.8 percent and 12.4 percent, for monoresistance, multidrug resistance (MDR), other patterns of resistance and resistance to at least one drug, whereas the acquired resistance (AR) rate was 14.5 percent, 20.3 percent, 10.9 percent and 45.7 percent, respectively, and the combined resistance (CR) rate was 9.2 percent, 4.9 percent, 4.2 percent and 18.3 percent, respectively. In PR, streptomycin was the most common drug, whereas isoniazid was the most common in AR and CR (7.2 percent and 3.7 percent, respectively). CONCLUSIONS: These high levels of resistance undermine the efforts for tuberculosis control in Mato Grosso do Sul. Acquired MDR was 12.7 times more common than was primary MDR, demonstrating that the previous use of drug therapy is an indicator of resistance. These levels reflect the poor quality of the health care provided to these patients, showing the importance of using the directly observed treatment, ...

Importancia de la cobertura antimicrobiana y de las resistencias bacterianas en la elección de antibióticos en Pediatría / Importance of the antimicrobial spectrum and the bacterial resistances in the antibiotic Choice for the treatment of pediatric patients with comunitary infections

Objetivo. Conocer la importancia de la cobertura antimicrobianay de las resistencias bacterianas, así como su relacióncon otros parámetros terapéuticos, a la hora de elegirun tratamiento antimicrobiano en pacientes pediátricos.Material y métodos. Estudio obsevacional transversal,enmarcado en el Proyecto MUSA (Mejora del Uso de los Antimicrobianos)en la atención primaria de salud, realizadomediante entrevista personal a 210 pediatras, seleccionadosde forma aleatoria, con representatividad a nivel nacional.Esta muestra fue extraída de otra mayor (855 médicos), querepresentaba a la práctica totalidad de médicos responsablesde la prescripción de antimicrobianos en el ámbito extrahospitalario(error muestral del 3,3% para un margen de confianzadel 95% y un grado de dispersión de respuesta máximo:p=q=50).Los resultados del estudio en pediatría se sometieron a unanálisis comparativo con los obtenidos con un estudio de lasmismas características realizado 10 años atrás y con los resultadosglobales del estudio general.El cuestionario utilizado en la entrevista tenía dos partesclaramente diferenciadas: en la primera de ellas, se tratabade preguntas abiertas con objeto de conseguir respuestas espontáneasde los participantes; la segunda parte, conteníacuestiones con respuestas sugeridas.Resultados. La eficacia clínica es el aspecto más valoradode forma espontánea por los pediatras españoles a la hora deelegir un antimicrobiano; a la eficacia, le siguen la tolerancia/seguridad y la posología. La cobertura antimicrobiana escitada por uno de cada 4-5 pediatras participantes en el estudio(21,9%), mientras que las resistencias bacterianas sóloson citadas por el 3,8% (AU)

Objective. This study aimed to know the importanceof the antimicrobial spectrum and the bacterial resistances for the antibiotic choice in the extrahospitalarypediatric area, at the same time that establish the relationshipwith others therapeutics parameters.Material and methods. Cross-sectional, observationalstudy within the MUSA (Improvement of Use of AntimicrobialAgents in Primary Health Care) Project made bypersonal interview of 210 pediatrician doctors randomlyselected with national represantitivity. This target is includedin a bigger universe (855 doctors) representativeof the most doctors responsible of the antibiotic prescriptionsin the extrahospitalary area (sample error ofthe 3,3 % for a 95 % confidence interval and maximumresponse dispersion: p=q=50).The results of the pediatric study were subjected to acomparative analysis with the results of a similar studymade ten years ago and with the global results of thegeneral study.The questionnaire used for the interview had twocrearly differenced parts: in the first part, the questionswere open with the objective to get spontanious answersfrom the participants; the second part had questions withsuggested answers.Results. Clinical efficacy is the most spontaneouslyvalored issue by the spanish pediatricians when it comesto choosing an antimicrobial agent; efficacy is followedby tolerance/safety and posology. Antimicrobial spectrumis mentioned by one out of 4-5 pediatricians thathave participated in the study (21,9%), while the bacterialresistances are only mentioned by a 3,8% (AU)

Estudio comparativo de las infecciones urinarias en un área sanitaria (1992-2006) / Comparative study of urinary infections in a health care area (1992-2006)

Objetivo: Conocer la flora bacteriana causante de las infecciones urinarias en nuestra área sanitaria durante un año y su sensibilidad a los antimicrobianos más utilizados. Comparar los resultados con un estudio previo similar realizado catorce años antes. Material y métodos: Análisis retrospectivo de los urocultivos de pacientes pediátricos enviados al Servicio de Microbiología del Hospital de Cabueñes (Gijón), tanto desde Atención Primaria, como desde nuestro propio Servicio entre enero y diciembre de 2006.Resultados: Se obtuvieron un total de 292 urocultivos positivos (60% pacientes de sexo femenino), de los cuales122 (42%) fueron remitidos desde Atención Primaria. El microorganismo aislado más frecuente fue Escherichia coli (71,9%), seguido de Proteus (13,6%), Enterococcus faecalis(5,4%), Klebsiella pneumoniae (2,1%) y Pseudomonas aeruginosa(1,7%). Los antibióticos más eficaces por vía oral fueron cefixima, cefuroxima, amoxicilina-clavulánico y fosfomicina, mientras que cefotaxima, gentamicina y amoxicilina-clavulánico ofrecen buenos resultados en uso hospitalario. Existen escasas variaciones en el perfil etiológico yla sensibilidad a antimicrobianos con respecto a la muestra de nuestra área sanitaria realizada en 1992-93 y otros estudios similares realizados en el ámbito de nuestra sociedad regional. Conclusiones: El perfil bacteriológico de los uropatógenos y su patrón de sensibilidad a antimicrobianos mostraron escasa variabilidad en nuestro medio a lo largo del período de tiempo observado. La muestra obtenida ofrece resultados similares a otros estudios de nuestro ámbito regional. Es necesario continuar con un uso racional de los antibióticos en función de los antibiogramas locales para la máxima optimización de su eficacia en el tratamiento de las infecciones urinarias pediátricas (AU)

Objetive: To know variations in local aetiology and treatment options in children with urine infections. Material and methods: Retrospective etiologic and antibiotic susceptibility study performed in a secondary hospital. All positive urine cultures received in Microbiology Department of Hospital de Cabueñes in 2006 were analysed. We have compared our results with a sample collected in the same area in 1992-93. Results: 292 urine cultures were included; 122 of them were sent by Primary Care Centers. Escherichia coli was the most common cause of urinary tract infections (71,9%), followed by Proteus (13,6%), Enterococcus faecalis (5,4%), Klebsiellapneumoniae (2,1%) and Pseudomonas aeruginosa (1,7%).Cefixime, cefuroxime, amoxicillin-clavulanate acid and phosphomicinwere the most appropriate oral treatment. Hospital treatment was the orically effective using cefotaxime, gentamicina and amoxicillin-clavulanate acid. Little differences about etiological profile and sensitive pattern were observed comparing with a similar study made in 1992-93.Conclusions: Aetiology of pediatric urinary tract infections and antimicrobial susceptibility show little variations along time in our study. It is necessary, somehow, periodical geographic studies to provide the best choice of empirical antibiotic treatment (AU)

Enfoque terapéutico de las neumonías en la infancia / General management of pneumonia in childhood

Los niños con neumonía y afectación media o moderada pueden ser cuidados en su domicilio con seguridad y reexaminados a las 48 horas del inicio del tratamiento. En los niños pequeños, una afectación más intensa –como tener una SaO2 <92%, cianosis, polipnea >70 rpm, esfuerzo respiratorio, apneas intermitentes, quejido, incapacidad para ingerir alimentos y limitación para observación o supervisión familiar– es indicación para su ingreso hospitalario. En los niños más mayores, estas indicaciones serían una SaO2 <92%, cianosis, polipnea >50 rpm, dificultad para ingerir líquidos o alimentos, quejido, signos de deshidratación o dificultad familiar para su observación o supervisión. Como los virus son la causa única de muchos casos de neumonía en la infancia no parece apropiado tratar a cada niño con antibióticos. Las decisiones terapéuticas en un niño concreto pueden ser difíciles, pues la mayoría de las pruebas no son útiles para diferenciar de modo adecuado las infecciones virales de las bacterianas. La resistencia antibacteriana se ha incrementado constantemente en los últimos años y está relacionada con su uso abusivo en situaciones en que la afectación viral es muy probable o la enfermedad es leve y limitada a vías superiores. Por esta razón, es preferible restringir los antibióticos tanto como sea posible y, si se usan, utilizar agentes de espectro estrecho siempre que sea posible, pues la menor presión antibiótica limita la emergencia de resistencia antibiótica. Finalmente, se comenta el enfoque terapéutico de las neumonías, de acuerdo con la edad, la repercusión sobre el estado general, el patrón radiológico, los datos de laboratorio y la epidemiología de estas infecciones en nuestro medio (AU)

Infants and children with moderate pneumonia can be safely cared for at home and should be re-examined within 48 hours of the beginning of treatment. An SaO2 of 92% or less, cyanosis, respiratory rate greater than70 breaths per minute, difficulty in breathing, intermittent apnea, grunting, inability to eat, and a family incapable of providing appropriate observation or supervision are indicators for hospital admission among infants. In the case of older children, theses indicators are an SaO2 of 92% or less, cyanosis, respiratory rate greater than 50 breaths per minute, difficulty in the intake of fluids or solids, grunting, signs of dehydration, or a family incapable of providing either appropriate observation or supervision. Since viruses are the sole cause of many cases of pneumonia in childhood, it is not appropriate to treat every child with antibiotics. However, therapeutic decisions can be difficult, because most tests do not adequately differentiate viral from bacterial infection in a given child. The problem of bacterial resistance to antibiotics has increased steadily in recent years, and it is certainly related to their overuse in situations in which viral involvement is quite probable or the illness is trivial and self-limiting, such as an upper respiratory infection. Hence, it is preferable to restrict antibiotics as much as possible and to use narrow-spectrum agents whenever appropriate, because less antibiotic pressure limits the emergence of bacterial resistance. Finally, we comment on the general management of pneumonias depending on the age, the impact on the general condition of the patient and the radiological pattern, laboratory data and the epidemiology of these infections in our general population (AU)

Situación actual de las resistencias a antibióticos en infecciones amigdalares / Present situation of antibiotic resistances in tonsillar infections

Objetivo: Obtener los principales microorganismos y resistencias a antibióticos en infecciones amigdalares. Material y métodos: Realizamos un estudio microbiológico con antibiograma de amígdalas palatinas postquirúrgicas. Resultados: Los microorganismos más aislados han sido el Staphylococcus aureus (29,3%) seguido del Streptococcus pyogenes (23,4%), y del Haemophilus influenzae (12,1%). Las mayores resistencias fueron para el S. aureus (91% a la penicilina, 18% a la eritromicina y un 5% al resto de β-lactámicos), seguido del H. influenzae (50% a la claritromicina, 30% a la amoxicilina y 2% a cefalosporinas) y por último el S. pyogenes (28% a la eritromicina, 10% a la clindamicina y 3% a la penicilina). Conclusiones: Destacamos la mínima resistencia encontrada a las cefalosporinas por lo que parece ser el grupo antibiótico más seguro, excepto en los niños menores de 5 años en los cuales la amoxicilina sigue siendo de primera elección dado que están provocadas por S. pyogenes sensibles a dicho antibiótico

Objective: To obtain the main responsible organisms, its sensitivity and resistances to antibiotics in tonsillitis. Material and methods: We have studied the post-surgical tonsils, carrying out a microbiologic study, its culture and sensitivity. Results: The most frequent isolated organisms were Staphylococcus aureus (29.3%), followed by Streptococcus pyogenes (23.4%), and Haemophilus influenzae (12.1%). The highest resistances were for the S. aureus (penicillin 91%, erythromycin 18% and 5% to the rest of the β-lactams), followed by H. influenzae (50% clarithromycin, 30% amoxycillin and 2% cephalosporins) and S. pyogenes (28% erytromycin, 10% clindamycin and 3% penicillin). Conclusions: We noticed the minimal resistance found to cephalosporins, and for this reason they appear to be the safest option, except in children under five years old, in which amoxicillin is still the first line treatment, because the causative agent is S. pyogenes, sensitive to that antibiotic

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