Introducción. Actualmente se considera a Enterococcus spp. como uno de los agentes de infección hospitalaria más importantes, siendo su resistencia a los antibióticos un problema importante en los centros de salud. Objetivos. Caracterizar la resistencia antimicrobiana en 50 cepas de Enterococcus spp. aisladas de muestras clínicas de pacientes hospitalizados . Materiales y métodos. Se llevó a cabo un estudio de tipo descriptivo observacional de corte transversal en 50 aislamientos clínicos de estas especies microbianas. Se trabajó un aislamiento por paciente. La identificación y la sensibilidad a los antibióticos se realizaron por métodos automatizados y convencionales. El análisis fenotípico de los mecanismos de resistencia a glucopéptidos se hizo según las recomendaciones de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. Resultados. De 50 aislamientos, 30 (60,0 %) y 20 (40,0 %) pertenecían a las especies de Enterococcus faecalis y Enterococcus faecium , respectivamente. La resistencia global expresada por este género fue de 38/50 (76,0 %) para ampicilina; 33/50 (66,0 %) para gentamicina de alto nivel; 34/50 (68,0 %) para estreptomicina de alto nivel; 26/50 (52,0 %) para ciprofloxacina; 4/50 (8,0 %) para linezolid; 17/50 (34,0 %) para teicoplanina; 25/50 (50,0 %) para vancomicina; 31/50 (62,0 %) para minociclina; 34/50 (68,0 %) para tetraciclina y 9/50 (18,0 %) para nitrofurantoina. Frente a los glucopéptidos, 25/50 (50,0 %) y 10/50 (20,0 %) de los aislamientos presentaron los mecanismos Van A y Van B, respectivamente. Conclusiones. Podemos concluir que la mayoría de las veces, las cepas aisladas en el Hospital Hermanos Ameijeiras mostraron porcentajes de resistencia por encima de lo reportado en la literatura científica consultada. El alto porcentaje de cepas con resistencia a la vancomicina podría influir en la aparición de otros gérmenes Gram positivos con resistencia a este fármaco. Se reporta por primera vez en un hospital cubano resistencia de E. faecium a linezolid.

Introduction: Enterococcus spp is currently considered as one of the most important nosocomial pathogens . The antibiotic resistance of this group of bacteria is a particularly important problem in health centers. Objective: To characterize the antibiotic resistance of 50 Enterococcus spp strains isolated from hospitalized patients clinical samples. Materials and methods: We conducted a cross-sectional descriptive observational study in 50 clinical isolates of Enterococcus spp. Only one isolate per patient was analyzed . The identification and antibiotic susceptibility were studied by conventional and automated methods . The phenotypic analysis of glycopeptide resistance mechanisms was performed as recommended by the Spanish Society of Clinical Microbiology and Infectious Diseases . Results: Of 50 isolates obtained from clinical samples, 30 ( 60.0%) belonged to Enterococcus faecalis and 20 (40.0 %) to Enterococcus faecium . The global resistance expressed by this genre was as follows: Ampicillin, 38/50 ( 76.0%); high-level gentamicin , 33/50 ( 66.0%); high-level streptomycin, 34/50 (68.0 %) ; ciprofloxacin, 26/50 (52.0 %); linezolid, 4/50 (8.0 %); teicoplanin, 17/50 ( 34.0%); vancomycin, 25/50 (50.0 %); minocycline, 31/50 ( 62.0%); tetracycline, 34/50 (68.0 %); nitrofurantoin, 9/50 ( 18.0%). As regards glycopeptides, 25/50 (50.0%) showed a Van A mechanism and 10/50 (20.0 %) a Van B mechanism . Conclusions: The isolates obtained at Hospital Hermanos Ameijeiras showed higher resistance rates than those reported in the consulted literature. The high percentage of vancomycin-resistant strains might have influenced the development of other Gram-positive bacteria resistant to this drug. This is the first report on Enterococcus faecium resistant to linezolid in a Cuban hospital.

Introduction: microbiological control of water and food has motivated the development of selective culture media capable of detecting Enterococcus, which need an appropriate source of energy to ensure the recovery of microorganisms. Objectives: compare different nutrient bases produced from food products and by-products according to their growth promotion capacity for the genus Enterococcus, and evaluate the accuracy of dextrose azide broth culture medium. Methods: eighty strains of different genera were selected for the test. Two experimental variants of dextrose azide broth were prepared (one buffered) and the microorganisms selected were inoculated at a standardized concentration. Biomass increase was determined by measuring optical density in a spectrophotometer at 640 nm every 1 h. Microbiological evaluation of the culture medium was carried out using different microbial genera at different concentrations. Diagnostic and relative sensitivity, specificity and accuracy, and the Kappa index were determined for the culture medium. Glucose azide broth (Merck, Germany) was used as reference medium. Results: the Enterococcus species evaluated showed higher biomass production than the other genera. The buffered formulation showed maximum growth of culture and this medium exhibited a higher inhibitory effect on the strains selected as negative control bacteria. The culture medium showed satisfactory results for diagnostic sensitivity, specificity and accuracy (97.7; 94.6; 96.3 %, respectively) and relative sensitivity, specificity and accuracy (100; 89.8; 94.8 %, respectively). These values were higher than those obtained with the reference medium. Kappa indices were ranged as "almost perfect". Conclusions: with the nutrient base obtained from beef heart, a by-product from the food industry (beef heart papainic peptone), better growth of the genus Enterococcus is obtained, as well as higher accuracy in the formulation when it is used as the main source of nutrients.

Introducción: el control microbiológico de aguas y alimentos ha motivado el desarrollo de medios de cultivo selectivos capaces de detectar Enterococcus, los cuales necesitan de una fuente de energía apropiada para garantizar la recuperación de estos. Objetivos: comparar diferentes bases nutritivas elaboradas a partir de productos y subproductos alimenticios según su capacidad de promoción de crecimiento del género Enterococcus y evaluar la exactitud del medio de cultivo caldo azida dextrosa. Métodos: para el ensayo se seleccionaron 80 cepas de diferentes géneros. Se prepararon dos variantes experimentales del caldo azida dextrosa (una tamponada) y se inocularon los microorganismos seleccionados a una concentración estandarizada. El incremento de la biomasa se determinó midiendo la densidad óptica en un espectrofotómetro a 640 nm cada una hora. La evaluación microbiológica del medio de cultivo se realizó utilizando diferentes géneros microbianos a distintas concentraciones. Se determinó la sensibilidad, especificidad, exactitud diagnóstica y relativa y el índice Kappa del diagnosticador. Como medio de referencia se utilizó el caldo azida glucosa proveniente de la firma comercial Merck (Alemania). Resultados: la producción de biomasa de las especies de enterococos evaluadas resultó superior con respecto a los otros géneros, siendo mayor en la formulación tamponada. De igual forma, esta logró un efecto inhibitorio superior sobre los controles negativos ensayados. El medio de cultivo mostró resultados satisfactorios de sensibilidad, especificidad y exactitud diagnósticas (97,7; 94,6; 96,3 %, respectivamente) y relativas (100; 89,8; 94,8 % respectivamente). Estos valores fueron superiores a los obtenidos con el medio de referencia. Los índices Kappa estuvieron en el rango de "casi perfecta". Conclusiones: con la base nutritiva obtenida del corazón de res, subproducto de la industria alimenticia (peptona papaínica de corazón de res) se obtiene un mejor crecimiento del género Enterococcus y una mayor exactitud en la formulación donde se encuentra como fuente principal de nutrientes.

INTRODUCTION: Nosocomial pneumonia associated with use of mechanical ventilators is one of the greatest challenges confronted by intensivists worldwide. The literature associates several bacteria with this type of infection; most common in intensive care units are Acinetobacter baumannii, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus and some of the Enterobacteriaceae family. OBJECTIVES: To identify the causal agents of nosocomial ventilatorassociated pneumonia in patients receiving mechanical ventilation in the intensive care units of Havana's Hermanos Ameijeiras Clinical-Surgical Teaching Hospital in 2011, and to characterize their antibiotic resistance. METHODS: A cross-sectional descriptive study was conducted using hospital administrative data of quantitative cultures from positive tracheal aspirates for January through December, 2011. Records were analyzed from 77 intensive care unit patients who developed nosocomial ventilator-associated pneumonia. Variables examined were age and sex, and pathogens identified from culture of tracheal aspirate and related antibiotic susceptibility. RESULTS: Species most frequently isolated were: Acinetobacter baumannii in 53 patients (68.8%), Pseudomonas aeruginosa in 34 patients (44.2%), other species of Pseudomonas in 15 patients (19.5%), and Serratia marcescens, Klebsiella pneumoniae, and Escherichia coli in 12 patients each (15.6%). Some patients presented more than one pathogen in concurrent or successive infections. Antimicrobial susceptibility testing found high percentages of resistance to antibiotics in all these pathogens. Least resistance was found to colistin. CONCLUSIONS: The prevalence of antibiotic resistance in bacteria causing nosocomial ventilator-associated pneumonia is of concern. Colistin is the drug of choice among the antibiotics reviewed, but sensitivity to other antibiotics should be assessed to search for more appropriate broad-spectrum antibiotics for treating nosocomial ventilator-associated pneumonia. Our results also suggest the need to strengthen infection control efforts, particularly in intensive care units, and to reassess compliance with quality control procedures. Multidisciplinary research involving microbiologists, epidemiologists, internists and intensivists is needed to fully understand the etiological and resistance patterns observed.

OBJECTIVE: To characterize mechanical ventilation-associated pneumonia (MVAP). METHOD: This is an observational descriptive study to characterize MVAP in 61 ventilated patients admitted in the intensive care units of the Hermanos Ameijeiras hospital during 2011. This study also aimed to isolate the bacteria causing MVAP and characterize their resistance to antibiotics. RESULTS: 51 (83.60%) patients presented pulmonary infiltrates and 35 (50.81%) presented a clinical score > 6 according to the Clinical Pulmonary Infection Score. Acinetobacter baumannii and Pseudomonas aeruginosa were the most frequently isolated microorganisms from patients with MVAP. Both microorganisms showed a high resistance to antibiotics. Carbapenems were the most frequent used antimicrobial therapeutic agents; elective antibiotic combinations were directed against both bacterial wall structure and nucleic acid synthesis. CONCLUSION: Patients with MVAP identified during the studied period showed similar frequency to those reported in medical literature. Thus, this study corroborated that this is still a relevant medical problem in this hospital. Acinetobacter baumannii and Pseudomonas aeruginosa were the most frequently isolated microorganisms from patients with MVAP. Antimicrobial treatment, empirical or not, are still the main risk factors for the development of multidrug-resistant strains of bacteria. The rate of resistance to antibiotics of Acinetobacter baumannii and Pseudomonas aeruginosa strains isolated from patients with MVAP was higher than those isolated from infected patients without MAVP. Tigecycline and colistin were the only antibiotics fully effective against Acinetobacter baumannii strains isolated in 2011 from patients with MVAP; against Pseudomonas aeruginosa strains, only colistin was fully effective.

Both Acinetobacter baumannii and Pseudomonas aeruginosa are considered to be causal agents of severe lower respiratory tract infections in patients under mechanical ventilation in intensive care units. A descriptive cross-sectional study was conducted with 36 mechanically ventilated patients from intensive care units to compare the importance of the two species. The most relevant results showed that of 20 patients with A. baumannii, 15 (75.00 %) developed ventilator-associated pneumonia, and 10 (50.00 %) died with sepsis vs. 13 (100 %) patients with Ps. aeruginosa, of whom 12 (92.30 %) developed ventilator-associated pneumonia and 4 (30.76 %) died with sepsis. It is concluded that of the two microbial species, Acinetobacter baumannii was found in most patients with ventilator-associated pneumonia and in those for whom sepsis played a significant role as a cause of death.

Tanto Acinetobacter baumannii como Pseudomonas aeruginosa son considerados agentes causales de severas infecciones respiratorias bajas en pacientes sometidos a ventilación mecánica en las unidades de cuidados intensivos. Se realizó un estudio descriptivo de corte transversal a 36 pacientes con ventilación mecánica en estas unidades con el objetivo de comparar la la repercusión de ambas especies. Los resultados más relevantes indicaron que de 20 pacientes con A. baumannii, 15 (75,00 %) desarrollaron neumonía asociada a la ventilación y 10 (50,00 %) fallecieron sépticos vs. 13 (100 %) pacientes con Ps. aeruginosa de los cuales 12 (92,30 %) desarrollaron neumonía asociada a la ventilación y 4 (30,76 %) fallecieron sépticos. Se concluye que entre ambas especies microbianas Acinetobacter baumannii fue encontrado en la mayoría de los pacientes con neumonía asociada a la ventilación y en aquellos en los que la sepsis desempeñó un papel significativo como causa de muerte.

OBJECTIVE: This observational study described the characterization of bacteria isolated from the lower respiratory tract of ventilated patients hospitalized in intensive care units. The demonstration of isolated microorganism resistance to antibiotics and a time-trend analysis of infection comparing a 48-month period were also other objectives. METHOD: Semi-quantitative assays of 1254 samples taken from 741 ventilated patients were performed, while pathogens were identified using the Enterotube II assay and VITEK 2 Compact equipment. Bacterial resistance to antibiotics was assessed by the Kirby-Bauer disc diffusion method and time-trend analysis of infection was based on data recorded by hospital microbiology laboratories. RESULTS: The most prevalent isolated bacteria from the patient's lower respiratory tract were with Gram-negative bacteria (67.8%) mostly represented by: Acinetobacter spp. (25.2%), Pseudomonas spp. (18.3%) and Klebsiellas spp. (9.4%). Acinetobacter spp. showed moderate high to very high resistance to ceftriaxone (CRO), gentamicin (CN), amikacin (AK), meropenem (MRP), aztreonam (ATM) and piperacillin/tazobactam (TZP). Some isolates of Acinetobacter spp. resistant to colistin (CS) were identified in this patient population. Pseudomonas spp. and Klebsiella spp. were very highly resistant to ampicillin/sublactam (AMS) and with moderate or low resistance to CRO, ATM, MRP, AK, CN and TZP. A decrease in the Pseudomonas spp. prevalence rate was observed, whereas an increase in Acinetobacter spp. and Klebsiella spp. prevalence rates were observed in a 48-month period. CONCLUSION: This research corroborated that these nosocomial infections are a relevant medical problem in our context. The most prevalent bacterial infections in the lower respiratory tract of ventilated patients were by Acinetobacter spp., Pseudomonas spp. and Klebsiella spp. The panel of antibiotics used as preventive therapy was not the solution of infections and probably induced drug-resistance mechanisms in these isolated microorganisms.

INTRODUCTION: the infection caused by Paracapillaria philippinensis (Capillaria philippinensis) is clinically characterized as a progressive enteric illness with massive loss of proteins and a malabsorption syndrome that may become fatal. OBJECTIVE: the first report in Cuba of human infection with P. philippinensis. METHODS: the case of a Cuban male patient aged 21 years from the City of Havana, who had never been abroad, was described. This young man was admitted to the hospital because after having eaten one breadcrumb-covered fish, he started having diarrheic episodes that progressively increased up to more than 15 abundant diarrheas per day, without phlegm or blood, and a clinical picture of severe malnutrition and general symptoms of intensive asthenia and anorexia RESULTS: the lab diagnosis confirmed the presence of P. philippinensis eggs in feces. CONCLUSIONS: the clinical features of the patient and the finding of moderate eosinophilia in the hematological study agreed with published information. As far as we know, this is the first finding of a human infection caused by P. philippinensis in Cuba, and in the American continent as well. The epidemiological alert on the possible emergence of new cases of this parasitic infection in our geographic zone is important, mainly in those places where the habit of eating raw or undercooked fish is part of the local culture.

INTRODUCCIÓN: la infección por Paracapillaria philippinensis (Capillaria philippinensis), se caracteriza clínicamente como una enteropatía progresiva, con pérdida masiva de proteínas y un síndrome de malabsorción que puede llegar a ser mortal. OBJETIVO: reportar por primera vez en Cuba el hallazgo de infección humana por P. philippinensis. MÉTODOS: se describió el caso de un paciente de 21 años de edad, del sexo masculino, procedente de Ciudad de La Habana, y que nunca había viajado fuera del país. Ingresa porque después de la ingestión de un pescado empanado comenzó a presentar un cuadro diarreico que se fue intensificando con el transcurrir de los días, llegando a tener más de 15 deposiciones líquidas diarias, abundantes en cantidad, sin flemas ni sangre, acompañado de un cuadro de desnutrición severa, y síntomas generales de astenia y anorexia intensas. RESULTADOS: el diagnóstico de laboratorio confirmó la presencia en heces de huevos de P. philippinensis. CONCLUSIONES: las características clínicas del paciente y el hallazgo de una eosinofilia moderada, coinciden con lo descrito en la literatura. En nuestro conocimiento, este es el primer hallazgo de infección autóctona por P. philippinensis en humanos que se realiza en Cuba, y en el continente americano. Es importante la alerta epidemiológica sobre la posible emergencia de esta parasitosis en nuestra zona geográfica, sobre todo en aquellos lugares donde la costumbre de comer pescado crudo o mal cocido sea parte del contexto cultural.