Biogeochemistry and hydrography shape microbial community assembly and activity in the eastern tropical North Pacific Ocean oxygen minimum zone.

Oceanic oxygen minimum zones (OMZs) play a pivotal role in biogeochemical cycles due to extensive microbial activity. How OMZ microbial communities assemble and respond to environmental variation is therefore essential to understanding OMZ functioning and ocean biogeochemistry. Sampling along depth profiles at five stations in the eastern tropical North Pacific Ocean (ETNP), we captured systematic variations in dissolved oxygen (DO) and associated variables (nitrite, chlorophyll, and ammonium) with depth and between stations. We quantitatively analysed relationships between oceanographic gradients and microbial community assembly and activity based on paired 16S rDNA and 16S rRNA sequencing. Overall microbial community composition and diversity were strongly related to regional variations in density, DO, and other variables (regression and redundancy analysis r2  = 0.68-0.82), displaying predictable patterns with depth and between stations. Although similar factors influenced the active community, diversity was substantially lower within the OMZ. We also identified multiple active microbiological networks that tracked specific gradients or features - particularly subsurface ammonium and nitrite maxima. Our findings indicate that overall microbial community assembly is consistently shaped by hydrography and biogeochemistry, while active segments of the community form discrete networks inhabiting distinct portions of the water column, and that both are tightly tuned to environmental conditions in the ETNP.

Tétanos, una enfermedad que se creyó superada: revisión de caso / Tetanus, a disease that was believed to be overcomed: a case review

El tétanos generalizado es una enfermedad infecciosa altamente mortal sin intervenciones médicas y en nuestro tiempo, prevenible mediante inmunización activa. Se presenta el caso de un preescolar de 4 años quien sufre herida cortante en la palma de la mano izquierda y quien se presenta 4 días más tarde con datos clínicos de tétanos generalizado. Fue intubado y admitido a la terapia intensiva del Hospital del Niño Dr. José Renán Esquivel. Su hospitalización se vio caracterizada por neumonía nosocomial, una lesión anfractuosa lingual e inestabilidad autonómica. Además de la antibioticoterapia con metronidazol y la aplicación de inmunoglobulina antitetánica, precisó apoyo hemodinámico con dobutamina y norepinefrina. Para lograr un completo control de las crisis de hipertonía, se ofreció manejo con infusión de midazolam, levetiracetam, clobazam, baclofeno y toxina botulínica.

Generalized tetanus is a highly fatal infectious disease without medical interventions and in our time, preventable by active immunization. The case of a 4-year-old preschooler is presented who suffers a sharp wound in the palm of the left hand and who presents 4 days later with generalized tetanus. He was intubated and admitted to intensive care unit at Dr. José Renán Esquivel Children's Hospital. His hospitalization was characterized by nosocomial pneumonia, an anfractuous lingual lesion and autonomic instability. In addition to antibiotic therapy with metronidazole and the application of tetanus immunoglobulin, hemodynamic support with dobutamine and norepinephrine was required. To achieve complete control of hypertonic crisis, management with infusion of midazolam, levetiracetam, clobazam, baclofen and botulinum toxin was offered.

Cognition in psychiatry
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Cognition has attracted a growing interest in psychiatry. Since the 1990s, cognition as a whole has become an important determinant in the outcome of psychosis. Despite recent progress in the genetics of cognition, the development of new pharmacological compounds in order to improve cognition has not progressed as quickly. This issue will review and discuss the main areas of clinical and basic research in this domain.
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Using tracheal breathing sounds and anthropometric information for screening obstructive sleep apnoea during wakefulness.

Obstructive sleep apnoea (OSA) is a common yet underdiagnosed disorder. Undiagnosed OSA significantly increases perioperative morbidity and mortality for OSA patients undergoing surgery, requiring full anaesthesia. Tracheal breathing sounds characteristics during wakefulness have shown a high correlation with the apnoea-hypopnea index (AHI), while they are also affected by the anthropometric parameters, e.g., sex, age, etc. This study investigates the effects of the anthropometric parameters on our new quick objective OSA screening tool during wakefulness. Breathing sounds of 122 individuals (71 with AHI <15 as non-OSA and 51 with AHI > 15 as OSA) were recorded during wakefulness in the supine position. The spectra and bi-spectra of 81 (47 non-OSA) individuals' signals, which were randomly selected, were analysed as a training dataset to extract the most significant features with the lowest sensitivity to the anthropometric parameters. Using a support vector machine (SVM) classifier, these features resulted in 72.1, 64.7 and 77.5% testing classification accuracy, sensitivity and specificity, respectively. We also investigated classifying subjects into subgroups related to each anthropometric parameter and incorporating a voting procedure. This routine resulted in 83.6, 74.5 and 90.1% testing classification accuracy, sensitivity and specificity, respectively. In conclusion, it is possible to positively utilise the anthropometric information to enhance the classification accuracy for a reliable OSA screening procedure during wakefulness.

Draft Genome Sequence of "Candidatus Sulcia muelleri" Strain KPTW1 from Kolla paulula, a Vector of Xylella fastidiosa Causing Pierce's Disease of Grapevine in Taiwan.

The genome of "Candidatus Sulcia muelleri" strain KPTW1 from Kolla paulula, a vector of Xylella fastidiosa that causes Pierce's disease (PD) of grapevine in Taiwan, was sequenced. The strain has a genome size of 253,942 bp, GC content of 22.7%, 237 predicted protein-coding genes, and 34 RNA genes.

Enhancements to the multiple sleep latency test.

INTRODUCTION: The utility of multiple sleep latency tests (MSLTs) is limited to determining sleep onset latency (SOL) and rapid eye movement sleep latency. The odds ratio product (ORP) is a continuous index of sleep depth with values of 0, 1.0, and 2.5 reflecting very deep sleep, light sleep, and full wakefulness, respectively. We determined the time course of sleep depth during MSLT naps expecting that this would enhance the test's clinical utility. METHODS: Thirty MSLTs (150 naps) were performed for excessive somnolence. Patients indicated whether they slept (yes/no) after each nap. SOL was scored by two experienced technologists. Time course of ORP was determined with a commercial system. We determined ORP at SOL (ORPSOL), times ORP decreased <2.0, <1.5, <1.0 and <0.5 during the entire nap duration, and the integral of decrease in ORP over nap duration (ΔORPINT). RESULTS: SOL occurred almost invariably when ORP was between 1.0 and 2.0. Of 47 naps (21 patients) with SOL <5 minutes, ORP decreased <1.0 (light sleep) in <5 minutes in only 13 naps (nine patients) and <0.5 (deep sleep) in only two naps in one patient. The relation between ORPINT and frequency of sleep perception was well defined, allowing determination of a threshold for sleep perception. This threshold ranged widely (5-50 ΔORP*epoch). CONCLUSION: As currently identified, SOL reflects transition into a highly unstable state between wakefulness and sleep. Reporting the times of attaining different sleep depths may help better identify patients at high risk of vigilance loss. Furthermore, an ORPSOL outside the range 1.0-2.0 can help identify scoring errors.

Novel Mutations in the Voltage-Gated Sodium Channel of Pyrethroid-Resistant Varroa destructor Populations from the Southeastern USA.

The parasitic mite Varroa destructor has a significant worldwide impact on bee colony health. In the absence of control measures, parasitized colonies invariably collapse within 3 years. The synthetic pyrethroids tau-fluvalinate and flumethrin have proven very effective at managing this mite within apiaries, but intensive control programs based mainly on one active ingredient have led to many reports of pyrethroid resistance. In Europe, a modification of leucine to valine at position 925 (L925V) of the V. destructor voltage-gated sodium channel was correlated with resistance, the mutation being found at high frequency exclusively in hives with a recent history of pyrethroid treatment. Here, we identify two novel mutations, L925M and L925I, in tau-fluvalinate resistant V. destructor collected at seven sites across Florida and Georgia in the Southeastern region of the USA. Using a multiplexed TaqMan® allelic discrimination assay, these mutations were found to be present in 98% of the mites surviving tau-fluvalinate treatment. The mutations were also found in 45% of the non-treated mites, suggesting a high potential for resistance evolution if selection pressure is applied. The results from a more extensive monitoring programme, using the Taqman® assay described here, would clearly help beekeepers with their decision making as to when to include or exclude pyrethroid control products and thereby facilitate more effective mite management programmes.

Near-freezing effects on the proteome of industrial yeast strains of Saccharomyces cerevisiae.

At near-freezing temperatures (0-4°C), the growth of the yeast Saccharomyces cerevisiae stops or is severely limited, and viability decreases. Under these conditions, yeast cells trigger a biochemical response, in which trehalose and glycerol accumulate and protect them against severe cold and freeze injury. However, the mechanisms that allow yeast cells to sustain this response have been not clarified. The effects of severe cold on the proteome of S. cerevisiae have been not investigated and its importance in providing cell survival at near-freezing temperatures and upon freezing remains unknown. Here, we have compared the protein profile of two industrial baker's yeast strains at 30°C and 4°C. Overall, a total of 16 proteins involved in energy-metabolism, translation and redox homeostasis were identified as showing increased abundance at 4°C. The predominant presence of glycolytic proteins among those upregulated at 4°C, likely represents a mechanism to maintain a constant supply of ATP for the synthesis of glycerol and other protective molecules. Accumulation of these molecules is by far the most important component in enhancing viability of baker's yeast strains upon freezing. Overexpression of genes encoding certain proteins associated with translation or redox homeostasis provided specifically protection against extreme cold damage, underlying the importance of these functions in the near-freezing response.

Dengue: Un reto constante

El dengue es una enfermedad infecciosa causada por el virus del dengue, del género avivirus o estegomia calopus que es transmitida por mosquitos, principalmente por el mosquito Aedes aegypti. La infección causa síntomas generales e imprecisos similares al síndrome gripal y en ocasiones evoluciona hasta convertirse en un cuadro potencialmente mortal, llamado dengue grave (antes conocido como dengue hemorrágico). Es una infección muy extendida que se presenta en todas las regiones tropicales y subtropicales del planeta. En los últimos años la transmisión ha aumentado de manera predominante en zonas urbanas y semiurbanas convirtiéndose en un importante problema de salud pública, hasta el punto de que en la actualidad, más de la mitad de la población mundial está en riesgo de contraer la enfermedad. La prevención y el control del dengue dependen exclusivamente de las medidas e caces de lucha contra el vector transmisor. El caso que reportamos trata sobre una adolescente femenina de 14 años quien adquirió la infección por dengue manifestando los signos y síntomas característicos de la enfermedad y evolucionando al dengue grave con un desenlace fatal. Este caso destaca la importancia del diagnóstico temprano y el manejo adecuado del dengue tanto a nivel primario como en el tercer nivel de atención; y nos recuerda que se trata de una enfermedad cuya evolución puede culminar en la mortalidad de los afectados. 1

Dengue is an infectious disease caused by dengue virus, of avivirus gender or estegonomia calopus, that is transmitted by mosquitoes, mainly by the mosquito Aedes aegypti. Infection causes general and imprecise symptoms similar to in uenza syndrome; and sometimes progresses to become a potentially fatal disease, called severe dengue (formerly known as hemorrhagic dengue). It is a widespread infection presented in all tropical and subtropical regions of the world. In recent years increased transmission predominantly in urban and semi-urban areas becoming a major public health problem, to the extent that currently, more than half of the world population is at risk of contracting the disease. The prevention and control of dengue depend exclusively of e ective control measures against the transmitting vector. The case we report is about a 14 year old female who acquired dengue infection manifesting the signs and symptoms of the disease evolve to severe dengue eventually triggering the death of the patient. This case highlights the importance of early diagnosis and appropriate management both in primary health as tertiary, because the dengue it is a disease whose evolution can lead to the death of a ected.

Proteomic evolution of a wine yeast during the first hours of fermentation.

The inoculation of active dry wine yeast (ADWY) is one of the most common practices in winemaking. This inoculation exposes the yeast cells to strong osmotic, acidic and thermal stresses, and adaptation to the new medium is crucial for successful fermentation. We have analysed the changes that occur in the ADWY protein profile in the first hours after inoculation under enological-like conditions at a low temperature. Protein changes mainly included enzymes of the nitrogen and carbon metabolism and proteins related to the cellular stress response. Most of the enzymes of the lower part of the glycolysis showed an increase in their concentration 4 and 24 h after inoculation, indicating an increase in glycolytic flux and in ATP production. However, the shift from respiration to fermentation was not immediate in the inoculation because some mitochondrial proteins involved in oxidative metabolism were induced in the first hours after inoculation. Inoculation in this fresh medium also reduced the cellular concentration of stress proteins produced during industrial production of the ADWY. The only exception was Cys3p, which might be involved in glutathione synthesis as a response to oxidative stress. A better understanding of the yeast stress response to rehydration and inoculation will lead to improvements in the handling efficiency of ADWY in winemaking and presumably to better control of fermentation startup.

Fluidization of membrane lipids enhances the tolerance of Saccharomyces cerevisiae to freezing and salt stress.

Unsaturated fatty acids play an essential role in the biophysical characteristics of cell membranes and determine the proper function of membrane-attached proteins. Thus, the ability of cells to alter the degree of unsaturation in their membranes is an important factor in cellular acclimatization to environmental conditions. Many eukaryotic organisms can synthesize dienoic fatty acids, but Saccharomyces cerevisiae can introduce only a single double bond at the Delta(9) position. We expressed two sunflower (Helianthus annuus) oleate Delta(12) desaturases encoded by FAD2-1 and FAD2-3 in yeast cells of the wild-type W303-1A strain (trp1) and analyzed their effects on growth and stress tolerance. Production of the heterologous desaturases increased the content of dienoic fatty acids, especially 18:2Delta(9,12), the unsaturation index, and the fluidity of the yeast membrane. The total fatty acid content remained constant, and the level of monounsaturated fatty acids decreased. Growth at 15 degrees C was reduced in the FAD2 strains, probably due to tryptophan auxotrophy, since the trp1 (TRP1) transformants that produced the sunflower desaturases grew as well as the control strain did. Our results suggest that changes in the fluidity of the lipid bilayer affect tryptophan uptake and/or the correct targeting of tryptophan transporters. The expression of the sunflower desaturases, in either Trp(+) or Trp(-) strains, increased NaCl tolerance. Production of dienoic fatty acids increased the tolerance to freezing of wild-type cells preincubated at 30 degrees C or 15 degrees C. Thus, membrane fluidity is an essential determinant of stress resistance in S. cerevisiae, and engineering of membrane lipids has the potential to be a useful tool of increasing the tolerance to freezing in industrial strains.

A downshift in temperature activates the high osmolarity glycerol (HOG) pathway, which determines freeze tolerance in Saccharomyces cerevisiae.

The molecular mechanisms that enable yeast cells to detect and transmit cold signals and their physiological significance in the adaptive response to low temperatures are unknown. Here, we have demonstrated that the MAPK Hog1p is specifically activated in response to cold. Phosphorylation of Hog1p was dependent on Pbs2p, the MAPK kinase (MAPKK) of the high osmolarity glycerol (HOG) pathway, and Ssk1p, the response regulator of the two-component system Sln1p-Ypd1p. However, Sho1p was not required. Interestingly, phosphorylation of Hog1p was stimulated at 30 degrees C in cells exposed to the membrane rigidifier agent dimethyl sulfoxide. Moreover, Hog1p activation occurred specifically through the Sln1 branch. This suggests that Sln1p monitors changes in membrane fluidity caused by cold. Quite remarkably, activation of Hog1p at low temperatures affected the transcriptional response to cold shock. Indeed, the absence of Hog1p impaired the cold-instigated expression of genes for trehalose- and glycerol-synthesizing enzymes and small chaperones. Moreover, a downward transfer to 12 or 4 degrees C stimulated the overproduction of glycerol in a Hog1p-dependent manner. However, hog1Delta mutant cells showed no growth defects at 12 degrees C as compared with the wild type. On the contrary, deletion of HOG1 or GPD1 decreased tolerance to freezing of wild-type cells preincubated at a low temperature, whereas no differences could be detected in cells shifted directly from 30 to -20 degrees C. Thus, exposure to low temperatures triggered a Hog1p-dependent accumulation of glycerol, which is essential for freeze protection.

The HOG MAP kinase pathway is required for the induction of methylglyoxal-responsive genes and determines methylglyoxal resistance in Saccharomyces cerevisiae.

A sudden overaccumulation of methylglyoxal (MG) induces, in Saccharomyces cerevisiae, the expression of MG-protective genes, including GPD1, GLO1 and GRE3. The response is partially dependent on the transcriptional factors Msn2p/Msn4p, but unrelated with the general stress response mechanism. Here, we show that the high-osmolarity glycerol (HOG)-pathway controls the genetic response to MG and determines the yeast growth capacity upon MG exposure. Strains lacking the MAPK Hog1p, the upstream component Ssk1p or the HOG-dependent nuclear factor Msn1p, showed a reduction in the mRNA accumulation of MG-responsive genes after MG addition. Moreover, hyperactivation of Hog1p by deletion of protein phosphatase PTP2 enhanced the response, while blocking the pathway by deletion of the MAPKK PBS2 had a negative effect. In addition, the activity of Hog1p affected the basal level of GPD1 mRNA under non-inducing conditions. These effects had a great influence on MG resistance, as hog1Delta and other HOG-pathway mutants with impaired MG-specific expression displayed MG sensitivity, whereas those with enhanced expression exhibited MG resistance as compared with the wild-type. However, MG does not trigger the overphosphorylation of Hog1p or its nuclear import in the parental strain. Moreover, dual phosphorylation of Hog1p appears to be dispensable in the triggering of the transcriptional response, although a phosphorylable form of Hog1p is fundamental for the transcriptional activity. Overall, our results suggest that the basal activity of the HOG-pathway serves to amplify the expression of MG-responsive genes under non-inducing and inducing conditions, ensuring cell protection against this toxic glycolytic by-product.

Práticas alimentares e o cuidado da saúde: da alimentação da criança à alimentação da família / Nutrition habits and healthcare: feeding the children and the family

A alimentação é um aspecto fundamental para a promoção da saúde da criança. No entanto, nutrir, amamentar, comer e oferecer comida são práticas sociais. O objetivo deste estudo foi analisar o significado das práticas alimentares compreendendo as percepções, experiências e valores sobre a alimentação para mães de criança sob risco nutricional, moradoras da Rocinha e freqüentadoras do grupo de mães do Centro Municipal de Saúde Píndaro de Carvalho Rodrigues. Para análise e compreensão do problema, foi utilizado o método da pesquisa qualitativa, através de entrevistas semi-estruturadas e da observação participante. O estudo possibilitou identificar que os hábitos e as práticas alimentares são permeados pelo aprendizado materno, que tem início na infância e é associado aos hábitos urbanos de consumo. A amamentação, a introdução de alimentos complementares até a alimentação cotidiana da família é um processo construído pela experiência e aprendizado próprios de cada grupo social. Identificamos que as práticas alimentares são construídas a partir de diferentes dimensões: temporal, de saúde e doença, de cuidado, afetiva, econômica e de ritual de socialização, que se entrelaçam conformando uma rede. A partir desse entendimento podemos, profissionais de saúde e usuários dos serviços, intervir na realidade tendo em vista a melhoria da saúde da criança e da família.

Clinical predictors of sleep disordered breathing in children at moderate altitude.

BACKGROUND: Validated clinical indicators of sleep disordered breathing (SDB) in children are scarce and none generated at moderate altitude where hypoxemic complications could be frequent and oximetry evaluation might be very efficient. METHODS: A total of 158 children consecutively referred to a sleep clinic in Mexico City (2240 m) for suspected sleep apnea underwent clinical evaluation and nocturnal monitoring of pulse oximetry, snoring and body position. RESULTS: Mean age was 4.9 years (SD 2.5) and 68.4% were males. A total of 84% of children were found with more than five desaturations per hour (>/=4%) while 63% and 34% had more than 10 and 20 desaturations, respectively. Based on logistic regression models, age

Evaluación de la atención de enfermería a senescentes en intercurrencia en el hogar de ancianos de Palmarito durante el 2001 / Evaluation of the nursing care to senescents with intercurrent diseases in the home for elderly at Palmarito during, 2001

Resumen: Se evaluó la atención de enfermería a 18 senescentes en intercurrencia en el Hogar de Ancianos de Palmarito de Cauto del municipio Mella, provincia de Santiago de Cuba, durante el 2001, de los cuales se revisaron las historias clínicas correspondientes. Se realizó una auditoría retrospectiva de los procesos de atención de enfermería, que fueron clasificados como adecuados y no adecuados según criterios establecidos por las autoras, quienes también los relacionaron con el diagnóstico médico del paciente que tuvo la intercurrencia. Entre los principales resultados predominó el catarro común (72,2 por ciento), seguido de la infección urinaria y la linfangitis aguda, e igualmente primó la categoría de adecuados en los procesos de enfermería (66,7 por ciento), lo cual denota que si bien fue preponderantemente efectiva la labor desarrollada, es posible alcanzar mejores indicadores al respecto y obtener la excelencia en la calidad de los servicios de enfermería(AU)

Gene expression analysis of cold and freeze stress in Baker's yeast.

We used mRNA differential display to assess yeast gene expression under cold or freeze shock stress conditions. We found both up- and down-regulation of genes, although repression was more common. We identified and sequenced several cold-induced genes exhibiting the largest differences. We confirmed, by Northern blotting, the specificity of the response for TPI1, which encodes triose-phosphate isomerase; ERG10, the gene for acetoacetyl coenzyme A thiolase; and IMH1, which encodes a protein implicated in protein transport. These genes also were induced under other stress conditions, suggesting that this cold response is mediated by a general stress mechanism. We determined the physiological significance of the cold-induced expression change of these genes in two baker's yeast strains with different sensitivities to freeze stress. The mRNA level of TPI1 and ERG10 genes was higher in freeze-stressed than in control samples of the tolerant strain. In contrast, both genes were repressed in frozen cells of the sensitive strain. Next, we examined the effects of ERG10 overexpression on cold and freeze-thaw tolerance. Growth of wild-type cells at 10 degrees C was not affected by high ERG10 expression. However, YEpERG10 transformant cells exhibited increased freezing tolerance. Consistent with this, cells of an erg10 mutant strain showed a clear phenotype of cold and freeze sensitivity. These results give support to the idea that a cause-and-effect relationship between differentially expressed genes and cryoresistance exists in Saccharomyces cerevisiae and open up the possibility of design strategies to improve the freeze tolerance of baker's yeast.

Respiración y sueño: caso clínico de interés: niño de tres años de edad con síndrome de apnea obstructiva del seño grave e hipertensión pulmonar corregida con adenoamigdalectomía / Breathing and sleep. An interesting clinical case: three year old boy with severe obstructive sleep apnea and pulmonary hypertension reversed by adeno-tonsillectomy

Se presenta el caso de un niño de tres años y 11 meses de edad con hipertrofia de adenoides y amígdalas e historia de ronquido habitual, apneas observadas por los padres y sueño inquieto. En la polisomnografía se encontró que cursaba con síndrome de apnea obstructiva del sueño grave, debido a que presentaba un índice de apnea + hipopnea de 63.9 eventos por hora de sueño. Además, cursaba con hipoxemia e hipoventilación alveolar graves con valores promedio de SaO2 de 70.8 por ciento y PCO2et de 53 mmHg. También se demostró que tenía hipertensión pulmonar ligera y datos de cor pulmonale. El tratamiento con adenoamigdalectomía normalizó la respiración nocturna. Se hace una descripción clínica del caso, de la polisomnografía y una revisión del tema.

Riesgo quirúrgico en la apnea del sueño: implicaciones para las amigdalectomías / Surgical risk in sleep apnea: implications for tonsillectommies

El crecimiento amigdalino o adenoideo es una de las causas más frecuentes del síndrome de apnea obstructiva del sueño (SAOS), sobre todo en niños. La adenoamigdalectomía frecuentemente es curativa en estos pacientes, pero por otro lado tiene más riesgo que en niños sin el SAOS. Los pacientes con SAOS programados para adenoamigdalectomía requieren una valoración preoperatoria detallada que puede incluir una polisomnografía. Además son pacientes en quienes se necesita una vigilancia permanente desde el preoperatorio hasta el postoperatorio, los más graves en terapia intensiva. Es importante identificar entre los pacientes programados para adenoamigdalectomía a los que tienen signos y síntomas compatibles con el SAOS ya que conviene enviarlos a centros de referencia para su atención adecuada

Sépsis en la Unidad de Terapia Intensiva: Revisión de 12 años (1981-1992) / Sepsis within the intensive care unit: A 12 years review (1981-1992)

Realizamos una revisión retrospectiva de 12 años (1981-1992) para conocer la incidencia y evolución de la sepsis en niños admitidos a la Unidad de Terapia Intensiva del Hospital del Niño. Para clasificar los pacientes sépticos empleamos la nueva terminología recomendada recientemente. Encontramos un total de 815 niños infectados; de éstos, 171 (21 por ciento) tuvieron sepsis, 497 (61 por ciento) sepsis severa y 147 (18 por ciento) choque séptico. La documentación etiológica de la infección se logró en 212 casos (26 por ciento), con un predominio del Staphylococcus aureus y la Neisseria meningitidis. La letalidad global fue del (39 por ciento) 319 pacientes. Los factores del mal pronóstico fueron la presencia del choque séptico, la falla multisistémica y la etiología meningocóccica de la sepsis. Los niños que recibieron una terapia antimicrobiana inapropiada tuvieron una mortalidad mayor que los pacientes tratados adecuadamente según los patrones de susceptibilidad del germén aislado (53 por ciento) versus (34 por ciento, p=0.012). Este trabajo ofrece importante información sobre la magnitud y pronóstico de los niños con infecciones sistémicas severas manejados en nuestra institución