Bioactivity Profile of Polyunsaturated Fattyacid extracts from Sardinella longiceps and Sardinella fimbriata – A comparative study

The oceans have proved to be an interminable source of new and effective drugs. Innumerable studies have proved that specific compounds isolated from marine organisms have great nutritional and pharmaceutical value. Polyunsaturated fattyacids (PUFA) in general are known for their dietary benefits in preventing and curing several critical ailments including Coronary heart disease (CHD) and cancers of various kinds. Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) are two PUFA which are entirely marine in origin – and small Clupeoid fishes like sardines are known to be excellent sources of these two compounds. In this study, we selected two widely available Sardine species in the west coast, Sardinella longiceps and Sardinella fimbriata, for a comparative analysis of their bioactive properties. Both these sardines are known to be rich in EPA and DHA, however considerable seasonal variation in its PUFA content was expected and these variations studied. An extraction procedure to isolate PUFA at high purity levels was identified and the extracts obtained thus were studied for anti-bacterial, anti-diabetic and anti-cancerous properties.Samples of both the sardines were collected from landing centre, measured and their gut content analysed in four different months of the year – viz. June, September, December and March. The fish samples were analyzed for fattyacid using FAME method using gas chromatography to identify the full range of fattyacids and their respective concentration in each of the samples. The fattyacids were expressed in mg/g meat and later converted to percentage values against total fatty acids and total PUFA content. Fattyacids during winter season (Dec-Mar) were found to be generally higher than spawning season (June-Sept). PUFA dominated the profiles of both species and average PUFA content was also higher during winter. However, it was found that S. longiceps had proportionately higher EPA as compared to S. fimbriata which was DHA rich. Percentage of EPA and DHA also varied across months for both species – the spawning season seemed to show higher EPA content in S. longiceps and higher DHA content in S. fimbriata. Gut content analysis indicate that adult S. fimbriata is partial to zooplanktons which are DHA rich while adult S. longiceps feed mainly on EPA rich phytoplankton. Juveniles of both species, found mainly in winter, had a gut content showing more mixed diet. This difference in the feeding pattern reflect clearly in their PUFA profile – adult S. longiceps, which dominate the catch during the spawn season, feeding mostly on phytoplankton is concentrated with EPA while the juveniles which are found mostly in the winter season has slightly less EPA proportion as compared to adults. The same is true for S. fimbriata adults that are caught mostly in the spawning season; being rich in DHA as they feed mainly on zooplankton while the juveniles caught during winter season has a relatively lower concentration of DHA in their total PUFA.Various extraction procedures are known to obtain PUFA from fish oil. However, most of them do not give high purity and do not use materials indicated as safe. PUFA extracts have to be edible and should not have harmful substances for applying on mice and human subjects. Some PUFA extraction procedures, though pure and non-toxic, might induce cis-trans conversions during the extraction process. This conversion destroys the benefits of PUFA and at times is harmful to human body. A method free from these limitations has been standardized for this study. Gas Chromatography was performed on the extracts thus made to ensure that it is substantially pure. EPA: DHA ratios for both samples were derived - for S. longiceps this ratio was 3:2, while it was 3:8 for S. fimbriata.Eight common strains of gram positive and gram negative bacterial strains were subjected to the PUFA extracts from both species dissolved in acetone solution using Agar Well Diffusion method. The activity was studied against an acetone control. At the end of incubation period, zones of inhibition were measured to estimate the activity. Minimum inhibitory concentration for each of the active combinations was calculated by keeping p < 0.01 as significant. Four of the bacteria including multi-resistant Staphylococcus aureus were shown to be inhibited by the fish extracts. It was also found that the extracts from S. fimbriata were better than the one from S. longiceps in annihilating harmful bacteria.Four groups of mice subjects were studied to evaluate the antidiabetic properties of the PUFA extracts. Three groups were induced diabetes by administration of alloxan tetra hydrate. One group without diabetes was kept as control and another with diabetes was kept as diabetic control. For two diabetic groups, a prescribed amount of fish extracts were fed from each of the extracts. The biochemical parameters like serum glucose, total cholesterol, LDL & HDL cholesterol, triglycerides, urea and creatinine were sampled from all four groups at regular intervals of 7 days for a period of 28 days. It was found that groups fed with fish extracts had marked improvement in the levels of total LDL & HDL cholesterol, triglycerides and creatinine. Groups fed with extracts from S. fimbriata seem to have fared better as compared to S. longiceps. However, both groups did not show any marked improvement in blood glucose levels or levels of urea.Cell lines of MCF-7 (Breast Cancer) and DU-145 (Prostate Cancer) were used to analyse the cytotoxicity of the PUFA extracts. Both cell lines were subjected to MTT Assay and later the plates were read using an ELISA reader at a wavelength of 570nm. It was found that both extracts had significant cytotoxic effects against both cell lines and a peak cytotoxicity of 85-90% was apparent. IC50 values were calculated from the graphs and it was found that S. longiceps extracts had a slightly lower IC50 value indicating that it is toxic even at a lower concentration as compared to extracts from S. fimbriata.This study summarizes the bioactivity profile of PUFA extracts and provides recommendation for dietary intake; fish based nutritional industry and indigenous pharmaceutical industry. Possible future directions of this study are also elaborated.

lncidence of enterotoxigenic Staphylococcus aureus in relation to the microbial safety of seafood

A detailed study was made on the microbial quality, with special reference to food safety, of the fish and fishery products in the retail trade in Cochin and around. Also, farmed molluscan shellfishes like mussels and oysters were investigated for the microbial quality including the presence of pathogenic bacteria. Special stress has been given to monitor the incidence of coagulase positive as well as coagulase negative Staphylococcus in these products and their relative incidence have been recorded.In the next part, the investigation was centered mainly on toxigenic S.aureus. This is because among the Gram positive toxigenic bacteria, the Saureus with potential to produce thermostable enterotoxins are more relavent in food safety conceming seafoods in comparison with the Gram-negative pathogens like Salmonella and V.cholerae.The incidence, toxigenic potential and conditions of toxin production by S.aureus have been investigated in detail. An attempt has also been made to relate the toxigenisis with the presence of the concerned toxigenic genes in the genomes of S. aureus strains.

Polypropylene/metal oxide nanocomposites: fiber spinning and evaluation”

PP has been getting much attention over the years because it is a very durable polymer commonly used in aggressive environments including automotive battery casings, fuel containers etc. They are used to make bottles, fibers for clothing, components in cars etc. However, it has some shortcomings such as low dimensional and thermal stability. Materials such as metal oxides with sizes of the order 1–50 nm have received a great deal of attention because of their versatile applications in polymer/ inorganic nanocomposites, optoelectronic devices, biomedical materials, and other areas. They are stable under harsh process conditions and also regarded as safe materials to human beings and animals. In the present investigation, PP is modified by incorporating metal oxide nanoparticles such as ZnO and TiO2 by simple melt mixing method. Melt spinning method was used to prepare PP/metal oxide nanocomposite fibers. Various studies have been carried out on these composites and fibers. In the first part of the study, ZnO nanoparticles were prepared from ZnCl2 and NaOH in presence of chitosan, PVA, ethanol and starch. This is a simple and inexpensive method compared to other methods. Change in morphology and particle size of ZnO were studied. Least particle size was obtained in chitosan medium. The particles were characterized by using XRD, SEM, TEM, TGA and EDAX. Antibacterial properties of ZnO prepared in chitosan medium (NZO) and commercial zinc oxide (CZO) were evaluated using a gram positive and a gram negative bacteria

Development of nitrifying bacterial consortia for immobilizing in nitrifying bioreactors designed for penaeid and non-penaeid larval rearing systems in the tropics

Two ammonia oxidizing (AMOPCU-1 and AMONPCU-1) and two nitrite oxidizing (NIOPCU-1 and NIONPCU-1) consortia for activating nitrifying bioreactors and thereby establishing nitrification in penaeid and non-penaeid hatchery systems were developed by enrichment. For further amplification of the consortia a simple medium having seawater (either salinity 30 ‰ or 15 ‰) as base, supplemented with NH4+-N/NO2--N and PO4- and pH adjusted to 8 was identified. During the amplification in a fermentor the consortia exhibited excessive wall growth and diminished their yield coefficient posing difficulty in harvesting the cells completely. The consortia consisted of both Gram negative and Gram-positive bacterial cells embedded in a mucilaginous matrix of glycocalyx - like material presumably composed of polysaccharides. The consortia besides being useful in activating nitrifying bioreactors developed for shrimp/prawn hatchery systems can also be used as bioaugmentors in the bioremediation of ammonia and nitrite toxicity in aquaculture systems.

Characterization and Pathogenicity of Vibrio cholerae and Vibrio vulnificus from Marine environments

The genus Vibrioof the family Vibrionaceae are Gram negative, oxidasepositive, rod- or curved- rodshaped facultative anaerobes, widespread in marine and estuarine environments. Vibrio species are opportunistic human pathogens responsible for diarrhoeal disease, gastroenteritis, septicaemia and wound infections and are also pathogens of aquatic organisms, causing infections to crustaceans, bivalves and fishes. In the present study, marine environmental samples like seafood and water and sediment samples from aquafarms and mangroves were screened for the presence of Vibrio species. Of the134 isolates obtained from the various samples, 45 were segregated to the genus Vibrio on the basis of phenotypic characterization.like Gram staining, oxidase test, MoF test and salinity tolerance. Partial 16S rDNA sequence analysis was utilized for species level identification of the isolates and the strains were identified as V. cholerae(N=21), V. vulnificus(N=18), V. parahaemolyticus(N=3), V. alginolyticus (N=2) and V. azureus (N=1). The genetic relatedness and variations among the 45 Vibrio isolates were elucidated based on 16S rDNA sequences. Phenotypic characterization of the isolates was based on their response to 12 biochemical tests namely Voges-Proskauers’s (VP test), arginine dihydrolase , tolerance to 3% NaCl test, ONPG test that detects β-galactosidase activity, and tests for utilization of citrate, ornithine, mannitol, arabinose, sucrose, glucose, salicin and cellobiose. The isolates exhibited diverse biochemical patterns, some specific for the species and others indicative of their environmental source.Antibiogram for the isolates was determined subsequent to testing their susceptibility to 12 antibiotics by the disc diffusion method. Varying degrees of resistance to gentamycin (2.22%), ampicillin(62.22%), nalidixic acid (4.44%), vancomycin (86.66), cefixime (17.77%), rifampicin (20%), tetracycline (42.22%) and chloramphenicol (2.22%) was exhibited. All the isolates were susceptible to streptomycin, co-trimoxazole, trimethoprim and azithromycin. Isolates from all the three marine environments exhibited multiple antibiotic resistance, with high MAR index value. The molecular typing methods such as ERIC PCR and BOX PCR revealed intraspecies relatedness and genetic heterogeneity within the environmental isolatesof V. cholerae and V. vulnificus. The 21 strains of V. choleraewere serogroupedas non O1/ non O139 by screening for the presence O1rfb and O139 rfb marker genes by PCR. The virulence/virulence associated genes namely ctxA, ctxB, ace, VPI, hlyA, ompU, rtxA, toxR, zot, nagst, tcpA, nin and nanwere screened in V. cholerae and V. vulnificusstrains.The V. vulnificusstrains were also screened for three species specific genes viz., cps, vvhand viu. In V. cholerae strains, the virulence associated genes like VPI, hlyA, rtxA, ompU and toxR were confirmed by PCR. All the isolates, except for strain BTOS6, harbored at least one or a combination of the tested genes and V. choleraestrain BTPR5 isolated from prawn hosted the highest number of virulence associated genes. Among the V. vulnificusstrains, only 3 virulence genes, VPI, toxR and cps, were confirmed out of the 16 tested and only 7 of the isolates had these genes in one or more combinations. Strain BTPS6 from aquafarm and strain BTVE4 from mangrove samples yielded positive amplification for the three genes. The toxRgene from 9 strains of V. choleraeand 3 strains of V. vulnificus were cloned and sequenced for phylogenetic analysis based on nucleotide and the amino acid sequences. Multiple sequence alignment of the nucleotide sequences and amino acid sequences of the environmental strains of V. choleraerevealed that the toxRgene in the environmental strains are 100% homologous to themselves and to the V. choleraetoxR gene sequence available in the Genbank database. The 3 strains of V. vulnificus displayed high nucleotide and amino acid sequence similarity among themselves and to the sequences of V. cholerae and V. harveyi obtained from the GenBank database, but exhibited only 72% homology to the sequences of its close relative V. vulnificus. Structure prediction of the ToxR protein of Vibrio cholerae strain BTMA5 was by PHYRE2 software. The deduced amino acid sequence showed maximum resemblance with the structure of DNA-binding domain of response regulator2 from Escherichia coli k-12 Template based homology modelling in PHYRE2 successfully modelled the predicted protein and its secondary structure based on protein data bank (PDB) template c3zq7A. The pathogenicity studies were performed using the nematode Caenorhabditiselegansas a model system. The assessment of pathogenicity of environmental strain of V. choleraewas conducted with E. coli strain OP50 as the food source in control plates, environmental V. cholerae strain BTOS6, negative for all tested virulence genes, to check for the suitability of Vibrio sp. as a food source for the nematode;V. cholerae Co 366 ElTor, a clinical pathogenic strain and V. cholerae strain BTPR5 from seafood (Prawn) and positive for the tested virulence genes like VPI, hlyA, ompU,rtxA and toxR. It was found that V. cholerae strain BTOS6 could serve as a food source in place of E. coli strain OP50 but behavioral aberrations like sluggish movement and lawn avoidance and morphological abnormalities like pharyngeal and intestinal distensions and bagging were exhibited by the worms fed on V. cholerae Co 366 ElTor strain and environmental BTPR5 indicating their pathogenicity to the nematode. Assessment of pathogenicity of the environmental strains of V. vulnificus was performed with V. vulnificus strain BTPS6 which tested positive for 3 virulence genes, namely, cps, toxRand VPI, and V. vulnificus strain BTMM7 that did not possess any of the tested virulence genes. A reduction was observed in the life span of worms fed on environmental strain of V. vulnificusBTMM7 rather than on the ordinary laboratory food source, E. coli OP50. Behavioral abnormalities like sluggish movement, lawn avoidance and bagging were also observed in the worms fed with strain BTPS6, but the pharynx and the intestine were intact. The presence of multi drug resistant environmental Vibrio strainsthat constitute a major reservoir of diverse virulence genes are to be dealt with caution as they play a decisive role in pathogenicity and horizontal gene transfer in the marine environments.

Charakterisierung der mikrobiellen Population und Untersuchungen zum Quorum Sensing in der Rhizosphäre vom Weidelgras (Lolium perenne) auf einer Rückstandshalde der Kaliindustrie

Im Rahmen dieser Dissertation wurden die Dynamik und die Kommunikation innerhalb der mikrobiellen Population der Rhizosphäre von Deutschem Weidelgras (Lolium perenne) untersucht, welches auf einer teilweise rekultivierten Rückstandshalde der Kaliindustrie wuchs. Um die niederschlagsbedingte Auswaschung von Salzen zu reduzieren, wird die Rückstandshalde des Kaliwerks Sigmundshall (in Bokeloh bei Hannover) schrittweise mit dem technogenen Abdecksubstrat REKAL/SAV ummantelt. Dieses weist eine hohe Standfestigkeit und Wasserspeicherkapazität auf und kann zudem begrünt werden, wofür als Pionierpflanze Lolium perenne dient. Durch diese Rekultivierung wird Niederschlag besser gespeichert und über Evapotranspiration wieder in die Luft abgegeben, was letztendlich die Bildung von Salzwasser vermindert. Da das Abdecksubstrat neben alkalischem pH-Wert auch teilweise hohe Schwermetallkonzentrationen aufweist, sollte in der vorliegenden Arbeit erstmals die mikrobielle Rhizosphären-Gemeinschaft in diesem extremen Habitat mittels einer kulturunabhängigen Methode erforscht werden. Zudem wurden erste Untersuchungen angestellt, ob im Substrat die zelldichte-abhängige bakterielle Kommunikation (Quorum Sensing) nachgewiesen werden kann. Mittels extrahierter Gesamt-DNA wurde anhand der 16S rDNA die Analyse des „Terminalen Restriktonsfragmentlängenpolymorphismus“ (TRFLP) verwendet, um die komplexe bakterielle Rhizosphären-Gemeinschaft unter zeitlichen und lokalen Aspekten zu vergleichen. Auftretende Veränderungen bei den bakteriellen Populationen der jeweiligen Proben wurden durch eine Zu- oder Abnahme der auch als Ribotypen bezeichneten terminalen Restriktionsfragmente (TRF) erfasst. Hierbei zeigten sich am Südhang der Halde während der Sommermonate der Jahre 2008 und 2009 zwar Schwankungen in den bakteriellen Gemeinschaftsprofilen, es lagen jedoch keine eindeutigen Dynamiken vor. Im Vergleich zum Südhang der Halde wies der Nordhang eine höhere Ribotyp-Diversität auf, was mit der fortgeschritteneren Rekultivierung dieses Haldenabschnitts zusammenhängen könnte. Zusätzlich wurden Bakterien aus der Rhizosphäre von Lolium perenne isoliert und mithilfe der Biosensoren Agrobacterium tumefaciens A136 pCF218 pCF372 und Chromobacterium violaceum CV026 auf die Produktion von N-Acylhomoserinlactonen (AHLs) überprüft. Diese AHLs werden von Gram-negativen Mikroorganismen als Signalmoleküle verwendet, um ihre Genexpression zelldichteabhängig zu kontrollieren. Von den 47 getesteten Gram-negativen Rhizosphärenisolaten konnten nur bei einem reproduzierbar AHL-Moleküle mithilfe des Reporterstamms A. tumefaciens nachgewiesen werden. Der AHL-Produzent wurde als Pseudomonas fluorescens identifiziert. Mittels dünnschichtchromatographischer Analysen konnten die extrahierten bakteriellen AHL-Moleküle den N-Octanoyl-L-homoserinlactonen zugeordnet werden.

Facilitating folding of outer membrane proteins, roles of the periplasmic chaperone Skp and the outer membrane lipoprotein BamD

This thesis describes several important advancements in the understanding of the assembly of outer membrane proteins of Gram-negative bacteria like Escherichia coli. A first study was performed to identify binding regions in the trimeric chaperone Skp for outer membrane proteins. Skp is known to facilitate the passage of unfolded outer membrane proteins (OMPs) through the periplasm to the outer membrane (OM). A gene construct named “synthetic chaperone protein (scp)” gene was used to express a fusion protein (Scp) into the cytoplasm of E. coli. The scp gene was used as a template to design mutants of Scp suitable for structural and functional studies using site-directed spectroscopy. Fluorescence resonance energy transfer (FRET) was used to identify distances in Skp-OmpA complexes that separate regions in Scp and in outer membrane protein A (OmpA) from E. coli. For this study, single cysteine (Cys) mutants and single Cys - single tryptophan (Trp) double mutants of Scp were prepared. For FRET experiments, the cysteines were labeled with the tryptophan fluorescence energy acceptor IAEDANS. Single Trp mutants of OmpA were used as fluorescence energy donors. In the second part of this thesis, the function of BamD and the structure of BamD-Scp complexes were examined. BamD is an essential component of the β-barrel assembly machinery (BAM) complex of the OM of Gram-negative bacteria. Fluorescence spectroscopy was used to probe the interactions of BamD with lipid membranes and to investigate the interactions of BamD with possible partner proteins from the periplasm and from the OM. A range of single cysteine (Cys) and single tryptophan (Trp) mutants of BamD were prepared. A very important conclusion from the extensive FRET study is that the essential lipoprotein BamD interacts and binds to the periplasmic chaperone Skp. BamD contains tetratrico peptide repeat (TPR) motifs that are suggested to serve as docking sites for periplasmic chaperones such as Skp.

Monitoreo microbiológico de aire, superficies y manos del personal asistencial en entidades de salud : Departamento del Meta 2007

OBJETIVO: Cuantificar Bacterias gram positivas, Bacterias gram negativas y Hongos mediante monitoreo microbiológico de aire, superficies y manos del personal asistencial en cinco entidades de salud del departamento del Meta en el año 2007. MÉTODOS: Estudio ejecutado en cinco entidades, donde se realizó el diagnostico microbiológico del entorno hospitalario, tomando muestras en cada área asistencial de: superficies horizontales antes y después de aplicar el protocolo de limpieza y desinfección de cada institución, manos de personal asistencial antes y después del lavado rutinario de manos y del aire de áreas críticas y no críticas. RESULTADOS: La IPS 3 presentó el Aire de Zona crítica con mayor contaminación bacteriana y la IPS 4 mayor contaminación fúngica. Hospitalización, Urgencias y Apoyo diagnostico evidenciaron las mayores concentraciones microbianas. Se encontraron diferencias estadísticamente significativas entre la carga microbiana antes respecto a después del lavado de manos (p<0,05) y antes y después de la aplicación del protocolo de limpieza y desinfección de superficies. CONCLUSIONES: Con el presente estudio fue posible demostrar que la capacitación, supervisión y monitorización de los procesos de lavado de manos y limpieza y desinfección de superficies pueden llegar a garantizar la reducción de la biomasa bacteriana y fúngica presente en las entidades de la salud.

Factores asociados a infección por Acinetobacter baumannii en una Unidad de Cuidados Intensivos en Bogotá D.C.

INTRODUCCIÓN: Acinetobacter baumannii es un cocobacilo gram negativo, oportunista, de baja virulencia. En los últimos años, se ha convertido en responsable del aumento de la incidencia de infecciones en las Unidades de Cuidado Intensivo (UCI), que se caracterizan por multiresistencia a antibióticos de amplio espectro. METODOLOGÍA: Estudio de Casos y Controles Pareado, razón 1:4, en tres cohortes de brotes por A. baumannii 2006-2010 de un Hospital Universitario. Como medida de asociación se calculó el Odd Ratio con una confiabilidad del 95%, utilizando regresión logística condicional. RESULTADOS: Se identificaron 3 brotes en el periodo 2006-2010, de los cuales se obtuvo una muestra de 14 casos y 56 controles. En el análisis multivariado se encontró asociación estadísticamente significativa entre la infección/colonización por A. baumannii y el presentar algún estado de inmunosupresión (OR=15.45; IC95%=1.12-212.44) y el tener catéter venoso central en un tiempo superior a diez días (OR=13.74; IC95%=1.25-151.44). No se encontró asociación estadísticamente significativa entre infección/colonización y mortalidad. De 14 casos, 13 presentaron aislamientos de multiresistentes, 9 son de origen respiratorio, 2 hemocultivos y 3 de origen abdominal. La mortalidad en los casos no está asociada a procesos de inmunosupresión, bacteremias e infecciones/colonizaciones respiratorias. CONCLUSIONES: La infección/colonización por A. baumannii se asoció a estado de inmunosupresión del paciente y el tener catéter venoso central por más de 10 días, que se correlaciona con la intervención invasiva, frecuente en las Unidades de Cuidados Intensivos. No fue posible establecer diferenciación clara entre infección y colonización, y su asociación con la mortalidad de los pacientes.

Actividad antibacteriana del aceite esencial de la conobea scopariodes frente a cinco cepas bacterianas de interés clínico en Colombia

En Colombia el manejo de pacientes en los diferentes servicios hospitalarios han presentado inconvenientes en el combate de infecciones por bacterias y la resistencia de las mismas; el Staphylococcus aureus Escherichia coli y Pseudomonas aeruginosa, han demostrado evolución en la creación de generaciones resistentes y también han participado junto con la Salmonella y el B.cereus en brotes por ETAS como principales microorganismos causales. En el presente estudio se analizó el aceite esencial de la Conobea scoparioides para evaluar su actividad frente a cinco cepas bacterianas. Se obtuvo el AE y se prepararon las bacterias aplicándose pruebas de sensibilidad y no paramétricas para determinar el porcentaje de inhibición, la evaluación de la MIC y comparar la efectividad del aceite vs la estreptomicina. El aceite esencial presentó actividad principalmente contra el B. cereus con el mayor % de inhibición y una MIC de 3.2 ug/ml, caso diferente presentó P. aeruginosa con un % de crecimiento por encima del 50% presentando una MIC de 16.7 ug/ml. Finalmente podemos concluir que se presentó mayor actividad frente a bacterias gram positivas como el caso del B. cereus que en gram negativas con MIC bajas. Estos resultados permite comparar la actividad de la conobea con estudios recientes bajo la misma modalidad que permiten identificar nuevas plantas con actividad biológica y percibir que la conobea es efectiva en mayor proporción frente a bacterias gram positivas.

Comportamiento epidemiológico de la sepsis nosocomial en la Unidad de Recién Nacidos de la Fundación Cardioinfantil

Objetivo. Se realizó un estudio retrospectivo que describe las características demográficas, la etiología, los factores asociados, la mortalidad, la sensibilidad y la resistencia de los microorganismos a los antibióticos usados en sepsis nosocomial. Diseño del estudio. Se realizó la recolección de datos desde el 2004 hasta el primer trimestre del 2006. Se definió infección nosocomial probada como la infección diagnosticada después de 72 horas de hospitalización y que recibe manejo antibiótico mayor a 3 días. Resultados. Se revisaron 60 historias clínicas, en las cuales los gérmenes Gram negativos fueron los principales causantes de sepsis nosocomial, tanto intra como extrainstitucional; de ellos la k. pneumoniae fue el germen más frecuentemente encontrado. Conclusiones. Los gérmenes Gram negativos son los microorganismos predominantemente causantes de sepsis nosocomial en la Unidad de Recién Nacidos (URN) de la Fundación Cardioinfantil (FCI).

Prevalencia de betalactamasas de espectro extendido en Escherichia coli, Klebsiella pneumoniae y Klebsiella oxytoca del Hospital Occidente de Kennedy. Nivel III, Bogotá

El objetivo es calcular la prevalencia para Escherichia coli, Klebsiella pneumoniae y Klebsiella oxytoca, productoras de betalactamasas espectro extendido, en el Hospital Occidente de Kennedy Nivel III, de Bogotá. Metodología: se analizaron en el Hospital Occidente de Kennedy, durante el período comprendido entre el 20 de noviembre de 2002 y el 30 septiembre de 2003, 3.574 cultivos, en los cuales se identificaron 897 cepas de Kepsiella pneumoniae, Klebsiella oxytoca y Escherichia coli, mediante paneles de microdilución del sistema de MicroScan Dried Gram Negative, como prueba de cribado para la identificación de germen y susceptibilidad a betalactamasas de espectro extendido. Luego se realizó una prueba confirmatoria con paneles de sistema MicroScan Dried ESBL Confirmation, recomendada para su uso por el National Committee for Clinical Laboratory Standards (NCCLS), al evaluar la concentración inhibitoria mínima para ceftazidima y cefotaxima solos y en combinación con ácido clavulánico. Resultados: los resultados mostraron una prevalencia combinada de gérmenes productores betalactamasas igual a 18,6% (intervalo de confianza del 95%: 16,2%-21,4%). La prevalencia para Escherichia coli fue de 9,5%; para Klebsiella pneumoniae, de 43,5%, y para Klebsiella oxytoca, de 10,3%. Los índices de resistencia bacteriana más altos correspondieron a ceftriaxona y ceftazidima. Conclusión: el estudio demuestra una alta prevalencia de betalactamasas de espectro extendido en gérmenes gramnegativos, probablemente por el uso excesivo de antibióticos betalactámicos de amplio espectro. Además, se destaca la importancia de la detección con pruebas de susceptibilidad y confirmación, como apoyo para la instauración de medidas de control y de vigilancia epidemiológica, con el fin de reducir índices de resistencia bacteriana emergente.

Desenlaces de las infecciones respiratorias en la unidad de cuidado intensivo de la fundación neumologica colombiana

Las infecciones asociadas a ventilación mecánica (VM) son frecuentes en la unidad de cuidado intensivo (UCI). Existen dos infecciones: neumonía (NAV) y traqueobronquitis (TAV). NAV genera impacto negativo en los desenlaces de los pacientes al aumentar la morbilidad, mortalidad y los tiempos en UCI y VM, pero no se conoce el impacto de TAV. El objetivo de este estudio fue identificar si hay diferencias entre NAV y TAV. Materiales y métodos: Se realizó un estudio de cohortes entre 2009 y 2013 en la UCI de la Fundación Neumológica Colombiana. De los pacientes con NAV y TAV se obtuvieron datos demográficos, epidemiológicos, microbiológicos y desenlaces como tiempos de estancia en UCI, VM y de hospitalización y mortalidad. Se compararon estadísticamente mediante t de Student y Chi2 para datos normales y prueba de Mann-Whitney para datos no normales. Resultados: Los pacientes con NAV y TAV fueron similares en la condición de ingreso a UCI. Al diagnóstico de la infección hubo diferencias significativas entre grupos en la oxigenación y tiempo de estancia hospitalaria, en UCI y VM. La microbiología fue con predominio de gérmenes Gram negativos y presencia de multirresistencia en el 52.5% de casos, sin diferencias significativas entre grupos. En los desenlaces, se observó diferencias en los tiempos totales de estancia en UCI, hospitalización y VM, pero sin diferencia en ellos después del diagnóstico. No hubo diferencias significativas en mortalidad. Conclusiones: NAV y TAV son similares en el impacto sobre la evolución de los pacientes en cuanto a morbilidad, estancias y mortalidad.

Mediastinitis post revascularización miocárdica: impacto del cambio de profilaxis antibiótica en la fundación Cardioinfantil 2012 - 2013

INTRODUCCIÓN. La mediastinitis posterior a cirugía de revascularización miocárdica es una infección infrecuente, pero potencialmente fatal. En la Fundación Cardioinfantil se ha observado una tendencia al incremento de la misma en los últimos años, obligando a un cambio en las medidas de profilaxis antimicrobiana, pasando de cefalosporinas a vancomicina – gentamicina, sin embargo no se conoce aún el impacto de estas medidas. OBJETIVO: Determinar si el cambio de la profilaxis antibiótica en pacientes sometidos a revascularización miocárdica influye en una disminución de la incidencia de mediastinitis durante los años 2012 – 2013. METODOLOGÍA: Estudio de cohortes retrospectivo, evaluando la incidencia de mediastinitis post revascularización miocárdica, en pacientes expuestos a 2 diferentes tipos de profilaxis antimicrobiana (cefalosporinas vs vancomicina-gentamicina). Se describieron los patrones de susceptibilidad y resistencia de los patógenos encontrados en mediastinitis y la mortalidad de esta patología. RESULTADOS: Los patógenos más frecuentemente aislados en la mediastinitis fueron Staphylococcus aureus y Klebsiella pneumoniae, en la mayoría monomicrobiano. Se encontraron patógenos con perfiles de resistencia como betalactamasas de espectro extendido en Gram negativos y resistencia a la meticilina en cocos Gram positivos. El RR de mediastinitis del grupo expuesto a vancomicina-gentamicina respecto al grupo de cefalosporinas fue de 0,9 con IC 95% 0,28 – 3,28. CONCLUSIÓN: la epidemiologia microbiana de la mediastinitis no difiere de la reportada en otras series. La profilaxis antimicrobiana con vancomicina - gentamicina en pacientes sometidos a revascularización miocárdica, no redujo la incidencia de mediastinitis. Se propone regresar a la terapia de profilaxis con cefalosporinas.

Caracterización de los pacientes con catéter venoso central en un hospital universitario de cuarto nivel en Bogotá 2011 - 2013

Introducción: La utilización de catéteres venosos centrales (CVC) en la unidad de cuidado intensivo tiene gran importancia y amplio uso, son fuente de apoyo para la realización de varia actividades, pero con un gran potencial de complicaciones, por lo cual es fundamental conocer todos los aspectos relacionados con su uso, para así poder controlarlas. Métodos: Realizamos un estudio descriptivo de corte transversal con el objetivo de caracterizar los pacientes que requirieron CVC en el Hospital Universitario Fundación Santa Fe de Bogotá durante junio de 2011 y mayo de 2013, describimos sus complicaciones asociadas tanto mecánicas como infecciosas, determinamos la tasa de bacteriemia, gérmenes causales y sus patrones de resistencia. Resultados: Se colocaron 2.286 CVC, el 52,9% en hombres, la media de edad fue 58,9 años. El total de las complicaciones ascienden al 4,5%, infecciosas 4,0% y mecánicas 0,6%. Dentro de las mecánicas solo encontramos inmediatas, no tardías. Con respecto a las infecciosas encontramos infección del sitio de inserción y bacteriemia. Se documentó una tasa de bacteriemia de 3,4 por 1000-días catéter en 2013, en disminución con respecto a 2012 (3,9) y 2011 (4,4). El microorganismo mas frecuentemente aislado fue el Staphylococcus Coagulasa Negativo con patrón usual de resistencia. Conclusión: Las complicaciones asociadas al uso de CVC en el HUFSFB, se presentan en menor frecuencia a las descritas internacionalmente; la tasa de bacteriemia asociada al CVC ha disminuido año tras año, posiblemente asociado al cuidado mas estricto posterior a la implementación de protocolos de manejo.