[Outbreak of multiresistant and extended spectrum ß-lactamase producing Klebsiella pneumoniae in a high risk neonatal unit]. / Brote por Klebsiella pneumoniae multiresistente y productora de ß-lactamasa de espectro extendido en una unidad de alto riesgo neonatal.

Klebsiella pneumoniae as a producer of extended spectrum beta-lactamase (ESBL) has played an important role as a cause of infection in the neonatal high risk unit (NHRU) of the Autonomous Hospital Institute of the Universidad de Los Andes (AHIULA). In this paper an outbreak caused by this bacterial specie that affected neonates hospitalized in this unit during February 2007 is described. Besides, the environment and the personnel were studied as possible sources of this organism. The strains of K. pneumonia isolated from the outbreak had the same resistance phenotype, produced ESBL type TEM and SHV and belonged to the same genotype as the isolated strains from the hands and the soapy solutions, possible sources of infection. This indicates that it was the same clone. The outbreak was resolved using two important measurements: reinforcing hand washing and with the opportune treatment of neonates with imipenem.

Brote por Klebsiella pneumoniae multiresistente y productora de β-lactamasa de espectro extendido en una unidad de alto riesgo neonatal / Outbreak of multiresistant and extended spectrum β-lactamase producing Klebsiella pneumoniae in a high risk neonatal unit

Klebsiella pneumoniae productora de β-lactamasa de espectro expandido (BLEE) ha jugado un papel importante como causa de infecciones en la unidad de alto riesgo neonatal (UARN) del Instituto Autónomo Hospital Universitario de Los Andes (IAHULA). En el presente trabajo se describe un brote ocasionado por esta bacteria en los neonatos hospitalizados en dicha unidad durante el mes de febrero 2007, así como también, cepas aisladas en los meses siguientes al brote y además, se estudia el ambiente y el personal, como posible fuente de esta bacteria. Las cepas de K. pneumoniae aisladas del brote eran del mismo fenotipo de resistencia, productoras de (3LEE tipo TEM y SHV y pertenecían al mismo genotipo que las cepas aisladas de las manos y de las soluciones jabonosas, posible fuente de infección, lo cual indica que se trataba del mismo clon. El brote se resolvió usando dos importantes medidas: reforzando el lavado de manos y con la indicación oportuna de imipenem a los neonatos afectados.

Klebsiella pneumoniae as a producer of extended spectrum beta-lactamase (ESBL) has played an important role as a cause of infection in the neonatal high risk unit (NHRU) of the Autonomous Hospital Institute of the Universidad de Los Andes (AHIULA). In this paper an outbreak caused by this bacterial specie that affected neonates hospitalized in this unit during February 2007 is described. Besides, the environment and the personnel were studied as possible sources of this organism. The strains of K. pneumonia isolated from the outbreak had the same resistance phenotype, produced ESBL type TEM and SHV and belonged to the same genotype as the isolated strains from the hands and the soapy solutions, possible sources of infection. This indicates that it was the same clone. The outbreak was resolved using two important measurements: reinforcing hand washing and with the opportune treatment of neonates with imipenem.

Molecular basis of extended-spectrum beta-lactamase production in nosocomial isolates of Klebsiella pneumoniae from Mérida, Venezuela.

Twelve Klebsiella pneumoniae isolates resistant to expanded-spectrum cephalosporins and aztreonam, from patients with nosocomial septicaemia at the intensive care unit of the Andes University Hospital, Mérida, Venezuela, were studied for production of extended-spectrum beta-lactamase (ESbetaL) activity. All were also resistant to gentamicin, kanamycin, tetracycline and chloramphenicol but sensitive to cefoxitin, imipenem, amikacin and tobramycin. Production of ESbetaL activity was confirmed by restoring susceptibility to ceftazidime in the presence of clavulanic acid. All isolates carried an identical plasmid of approximately 87 kb. Resistance to beta-lactams, aminoglycosides, tetracycline and chloramphenicol was lost en bloc after plasmid curing by treatment with acridine orange and was transferable en bloc to Escherichia coli by conjugation. Transconjugants always showed the same plasmid profile as that of Klebsiella donors. Isoelectric focusing analysis of the crude extracts of transconjugants showed in all cases, the presence of two beta-lactamases of pI 5.4 and 8.2. Analysis of the plasmid carried by one of the transconjugants by means of hybridization assays, revealed the presence of both bla(TEM) and bla(SHV) determinants. Cloning and sequencing of each determinant identified them as bla(TEM-1) and bla(SHV-5), respectively, the latter being responsible for the ESbetaL activity. Results of this study indicate that ESbetaL determinants of the SHV-type carried by transferable elements, are spreading among nosocomial isolates of K. pneumoniae in Mérida, Venezuela.

[Clinical, epidemiological and microbiological aspects of Mobiluncus sp. in bacterial vaginosis]. / Aspectos clínicos, epidemiológicos y microbiológicos de Mobiluncus sp. en la vaginosis bacteriana.

BACKGROUND: In this paper, our goal was to determine the optimal isolation conditions, biochemical characterization, and preservation of species of the genus Mobiluncus, associated with bacterial vaginosis in patients attending the family planning clinic. Also, we tried to relate its presence with demographic variables and criteria used in the clinical diagnosis of bacterial diagnosis. METHODS: The specimen from the posterior fornix were collected and transported to the laboratory in a Stuart medium, one at room temperature and the other at 4 degrees C. These samples were inoculated in anaerobic culture media. RESULTS: Of a total of 92 patients studied, 61 (66.3%) were normal, 28 (30.4%) bacterial vaginosis, and 3 (3.3%) had intermediate vaginosis. There was statistically significant relationship only with intrauterine device use (p = 0.00499). The presence of curved rod, using Gram's method, was significantly related with pH (p = 0.00000) positive amines test (p = 0.00000), and the presence of clue cells (p = 0.00000). Mobiluncus was observed in 23 samples (82%), and the majority (15) using RLK agar (cold enrichment technique). With conventional techniques, we identified 12 strains as Mobiluncus curtisii and 3 strains as Mobiluncus mulieris. The strains of Mobiluncus sp. grew better from litmus milk conserved at -30 degrees C. CONCLUSION: Isolating Mobiluncus sp. is fairly easy, if the right media and the techniques are used.

[Characterization of plasmids which mediate resistance to multiple antibiotics in gram-negative bacteria of nosocomial origin]. / Caracterización de plásmidos que median la resistencia a múltiples antibióticos en bacterias gramnegativas de origen nosocomial.

BACKGROUND: The genetic and molecular mechanisms involved in antimicrobial resistance of 10 strains of gramnegative bacilli (1 Serratia marcescens; 2 Escherichia coli; 1 Proteus mirabilis; 4 Klebsiella pneumoniae; 1 Enterobacter cloacae y 1 Alcaligenes faecalis), isolated from adult patients with nosocomial pulmonary infection at the in-patient facilities of the University Hospital of Los Andes, Mérida, Venezuela, have been studied. METHODS: The antimicrobial susceptibility was determined by minimum inhibitory concentrations using the dilution method in agar. The study of extrachromosomal genes was carried out by conjugation, bacterial infection with the bacteriophage M13 and curing of plasmid by acridine orange. The plasmids were isolated by alkaline lysis and analysis of restriction endonuclease digestion was carried out separately using the enzymes EcoRI and HindIII. A DNA probe, derived from the region which encodes the TEM-1 beta-lactamase of the plasmid pBR322 was used for dot-blot hybridization tests. RESULTS: All of the gramnegative bacilli showed resistance to ampicillin, carbenicillin and cephalothin (> 128 micrograms/ml) and 3 strains also showed resistance to gentamicin (> 64 micrograms/ml). Genetic and molecular procedures showed the presence of conjugative plasmids of approximately 54 kb in all the 10 strains. The restriction patterns obtained by using EcoRI and HindIII indicated common DNA fragments in most of the plasmids studied. The dot-blot hybridization tests confirmed homology between the plasmids and the DNA probe used (TEM-1 beta-lactamase). CONCLUSIONS: In this study, the gramnegative bacteria of nosocomial origin harbored self-transferable plasmids of approximately 54 kb, which mediate resistance to gentamicin and encode a beta-lactamase of the TEM group.

[Comparative study of 4 methods for identifying species of the genus Aeromonas]. / Estudio comparativo de 4 métodos para la identificación de especies del género aeromonas.

It is given an explanation of the results obtained with the following methods: AEROKEY II, AEROKEY II + Abbot's scheme, Api 20 NE, and the Biolog System. The study was conducted with 38 strains of Aeromonas isolated from children under 5 with acute diarrheal disease (ADD). The AEROKEY II + Abbot's scheme proved to be the best identification method.

Especies de aeromonas asociadas a diarrea: características microbiológicas y clínicas / Species of aeromonas associated a diarrhea: characteristic microbiological and clinical

Para estudiar las características microbiológicas y clínicas de Aeromonas sp. asociada a Enfermedad Diarreica Aguda (EDA) se analizaron, desde junio de 1993 1 diciembre de 1994, 397 muestras de heces de niños menores de cinco años con EDA y 121 asintomáticos. Fueron aisladas en una frecuencia de 11,8 y 5,8 por ciento en los casos de EDA y control, respectivamente. A.hydrophila y A.caviae fueron las especies más aisladas en ambos casos. Como patógenos únicos se encontraron en un 38,3 por ciento, y asociados en un 61,7 por ciento. La presentación del cuadro clínico fue 50 por ciento de tipo disentérico: 33,33 por ciento de tipo secretorio y 16.66 por ciento de tipo indeterminado. El mejor medio de cultivo fue el DNA-ampicilina. Se obtuvo un 1 por ciento con producción de H2S y un 5 por ciento fermentadoras de la lactosa. En las cepas se detectó por lo menos dos de las enzimas estudiadas; en base a esto, existe una importante circulación de este género con capacidad de producir EDA

Bacterias anaeróbicas como agentes etiológicos de infecciones en el ganado vacuno / Anaerobic bacteria as etiology agent in infections in the cattle

Se estudiaron 14 muestras clínicas provenientes de ganado vacuno de las Haciendas El Joque y La Atalaya, Mérida, con el propósito de aislar bacterias anaeróbicas involucradas en procesos infecciosos que afectan al ganado y que muchas veces son causas de pérdida económicas en las explotaciones lecheras de la región. En 11 casos, de los 14 estudiados, se aislaron bacterias anaeróbicas. Fusobacterium necrophorum fue el micro-organismo anaerobio más frecuente aislado, asociado con otras bacterias anaeróbicas y facultativas anaerobias como Corynebacterium (Actinomyces) pyogenes. Bacteroides pigmentados fue aislado de los casos de pododermatitis estudiados, Clostridium perfrigens de un cuadro clínico de enterotexemia fulminante en un becerro y Actinomyces sp de muestras clínicas de un absceso en la región cervical de uno de los ejemplares estudiados. Los resultados obtenidos nos permiten presumir que probablemente la incidencia de estas infecciones por bacterias anaeróbicas sea alta y que muchas veces pueden pasar desapercibidas si no se hace un diagnóstico micro-biológico. Por lo tanto, es de gran interés para el veterinario tener conocimiento de estas infecciones para prevenirlas y controlarlas

Properties of a bacteriocin produced by Clostridium bifermentans 18137.

Una particula filamentosa, con um amplio espectro de actividad similar a una bacteriocina, producida por Clostridium bifermentans 18137 fue caracterizada parcialmente. La bacteriocina inhibio el crecimiento de Clostridium aerofoetidum y causo lisis de celulas viables, pero no de celulas previamente muertas por exposicion al aire. La particula fue precipitada por sulfato de amonio a 40% de saturacion, tuvo una densidad entre l,22 y 1,29 g/ml y consistio en filamentos helicoidales. Fue inactivada por pronasa, quimotripsina y calentamiento a 95o.C por 5 min. R Nasa, Ba++ y Cd++ inhibieron las lisis cuando se anadieron junto con la bacteriocina, pero se mantuvo la actividad inhibitoria bajo las mismas condiciones. Se encontro RNA asociado con la bacteriocina y fue removido solo parcialmente por tratamiento con R Nasa. Celulas de C. aerofoetidum tratadas con la bacteriocina sufreiron dano extenso que incluyo destruccion de la membrana citoplasmatica y la pared celular, y disolucion del contenido celular. Tambien se observo la formacion de esferoplastos y fantasmas bacterianos