Resumo A serrapilheira depositada na superfície do solo, em vários estágios de decomposição tem importância na produtividade primária que impacta nas comunidades microbianas e estocagem de carbono no solo. Objetivou-se neste trabalho avaliar o acúmulo e decomposição dos resíduos culturais de cupuaçu, guaraná, urucum e floresta na região do Amazonas. O estudo foi realizado no assentamento São Francisco, Canutama no Sul do Amazonas, em delineamento experimental de blocos casualisados, sendo que os tratamentos constaram de quatro áreas com diferentes culturas: 1- Guaraná; 2 – Cupuaçu; 3 – Urucum; 4 – Área de mata nativa (floresta), em parcelas subdivididas no tempo: 07, 15, 30, 60, 90, 120, 150, 180, 210, 240, 270 e 300, 330 dias após a distribuição das sacolas no campo, todas com 04 repetições. Para avaliar o aporte e frações dá serapilheira, foram utilizados coletores cônicos em cada área, sendo as coletas realizadas mensalmente no período de março de 2020 a fevereiro de 2021. A estimativa da taxa de decomposição da serrapilheira foi realizada pela quantificação da perda de massa, utilizando-se litter bags, os quais permitem analisar de forma direta a taxa de decaimento ao longo do tempo. Os ambientes de floresta e guaraná apresentaram as maiores produções de serapilheira, e maior deposição quando comparados aos ambientes cultivados com cupuaçu e urucum. As áreas de floresta e urucum apresentaram a maior velocidade de decomposição, já a situação inversa ocorreu sob o cultivo do cupuaçu e guaraná.

Abstract The litter deposited on the soil surface at various stages of decomposition is important for primary productivity that impacts the microbial communities and soil carbon storage. The objective of this study was to evaluate the accumulation and decomposition of cultural residues of Theobroma grandiflorum (Willd. ex. Spreng) Schum, Paullinia cupana (Mart.) Ducke, Bixa orellana L., and forest in the Amazon region. The study was carried out in the São Francisco settlement, Canutama in the south of Amazonas, in a randomized block experimental design, and the treatments consisted of four areas with different crops: 1 - P. cupana; 2 - T. grandiflorum; 3 - B. orellana; 4 - Native woodland area (forest), in time subdivided plots: 7, 15, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, and 330 days after the distribution of the bags in the field, all with four repetitions. To evaluate the contribution and fractions of litter, conical collectors were used in each area, and collections were performed monthly in the period from March 2020 to February 2021. The estimate of the decomposition rate of the litter was done by quantifying the loss of mass, using litter bags, which allow for a direct analysis of the rate of decay over time. The forest and P. cupana environments presented the highest litter production, and greater deposition when compared to environments cultivated with T. grandiflorum and B. orellana. The forest and B. orellana areas showed the highest speed of decomposition, while the opposite situation occurred under T. grandiflorum and P. cupana cultivation.

Objective: To compare plasma concentrations of cannabidiol (CBD) following oral administration of two formulations of the drug (powder and dissolved in oil), and to evaluate the effects of these distinct formulations on responses to emotional stimuli in healthy human volunteers. Methods: In a randomized, double-blind, placebo-controlled, parallel-group design, 45 healthy male volunteers were randomly assigned to three groups of 15 subjects that received either 150 mg of CBD powder; 150 mg of CBD dissolved in corn oil; or placebo. Blood samples were collected at different times after administration, and a facial emotion recognition task was completed after 150 min. Results: There were no significant differences across groups in the subjective and physiological measures, nor in the facial emotion recognition task. However, groups that received the drug showed statistically significant differences in baseline measures of plasma CBD, with a significantly greater difference in favor of the oil formulation. Conclusion: When administered as a single 150-mg dose, neither formulation of oral CBD altered responses to emotional stimuli in healthy subjects. The oil-based CBD formulation resulted in more rapid achievement of peak plasma level, with an approximate fourfold increase in oral bioavailability.

Abstract The gametogenesis and reproduction of S. elegans from the São Francisco River at Três Marias, Minas Gerais, were analyzed in this study. Steindachrina elegans is a species abundant in the São Francisco River basin and an important fish in the food chain. The size at first gonadal maturation (indicated by the total length of the shortest spermatid male and spawned female) was 10.5 cm and 15.0 cm, respectively. Reproduction occurred more frequently from September to April. This period had high water temperature values. A high frequency of females was observed at the mature and spawned stages and height gonadosomatic index (GSI). Meanwhile, in males, the reproductive peak was from November to February. The long spawning period and the histological characteristics of the spawned ovaries that contained oocytes at different stages of development along with post-ovulatory and atretic oocytes indicates that the spawning of S. elegans is of the partial type.

Objective: To compare plasma concentrations of cannabidiol (CBD) following oral administration of two formulations of the drug (powder and dissolved in oil), and to evaluate the effects of these distinct formulations on responses to emotional stimuli in healthy human volunteers. Methods: In a randomized, double-blind, placebo-controlled, parallel-group design, 45 healthy male volunteers were randomly assigned to three groups of 15 subjects that received either 150 mg of CBD powder; 150 mg of CBD dissolved in corn oil; or placebo. Blood samples were collected at different times after administration, and a facial emotion recognition task was completed after 150 min. Results: There were no significant differences across groups in the subjective and physiological measures, nor in the facial emotion recognition task. However, groups that received the drug showed statistically significant differences in baseline measures of plasma CBD, with a significantly greater difference in favor of the oil formulation. Conclusion: When administered as a single 150-mg dose, neither formulation of oral CBD altered responses to emotional stimuli in healthy subjects. The oil-based CBD formulation resulted in more rapid achievement of peak plasma level, with an approximate fourfold increase in oral bioavailability.

ABSTRACT The feeding behavior of the generalist predator Nabis punctipennis Blanchard (Nabidae) on Acyrthosiphon pisum Harris (Aphididae), two hemipterans common in alfalfa in Chile, was studied in a laboratory experiment using A. pisum, and Aphis craccivora Koch (Aphididae) as alternative prey, which is another common aphid in alfalfa. The presence of A. craccivora did not affect the predation of A. pisum by N. punctipennis. This finding on the predatory behavior of N. punctipennis is valuable to evaluate the potential of this nabid as a biological control agent of A. pisum.

RESUMEN Se estudió la conducta de alimentación del depredador generalista Nabis punctipennis Blanchard (Nabidae) sobre Acyrthosiphon pisum Harris (Aphididae), dos hemípteros comunes en alfalfa en Chile, mediante un experimento en laboratorio utilizando A. pisum y Aphis craccivora Koch (Hemiptera: Aphididae) como presa alternativa, otro áfido común en alfalfa. La presencia de A. craccivora no afectó la depredación de A. pisum por N. punctipennis. La información obtenida sobre la conducta de depredación de N. punctipennis es valiosa para evaluar su potencial como agente de control biológico de A. pisum.

Current pharmacotherapy of Parkinson’s disease (PD) is palliative and unable to modify the progression of neurodegeneration. Treatments that can improve patients’ quality of life with fewer side effects are needed, but not yet available. Cannabidiol (CBD), the major non-psychotomimetic constituent of cannabis, has received considerable research attention in the last decade. In this context, we aimed to critically review the literature on potential therapeutic effects of CBD in PD and discuss clinical and preclinical evidence supporting the putative neuroprotective mechanisms of CBD. We searched MEDLINE (via PubMed) for indexed articles published in English from inception to 2019. The following keywords were used: cannabis; cannabidiol and neuroprotection; endocannabinoids and basal ganglia; Parkinson’s animal models; Parkinson’s history; Parkinson’s and cannabidiol. Few studies addressed the biological bases for the purported effects of CBD on PD. Six preclinical studies showed neuroprotective effects, while three targeted the antidyskinetic effects of CBD. Three human studies have tested CBD in patients with PD: an open-label study, a case series, and a randomized controlled trial. These studies reported therapeutic effects of CBD on non-motor symptoms. Additional research is needed to elucidate the potential effectiveness of CBD in PD and the underlying mechanisms involved.

Abstract Oreomunnea mexicana is relict and threatened species; it constitutes a dominant tree element in the foggy forest of the Sierra Juárez, Oaxaca. The species is emblematic and is incorporated into the worldview of the inhabitants of the region, where, in addition, it performs very important ecological functions and ecosystem services. The aim of the present work was to analyze the diversity and genetic structure, as well as to evaluate the spatial genetic structure on a fine scale using molecular markers for in situ conservation activities. Dominant markers called inter simple sequence repeat were used with which individuals from nine populations (25 per population) and 120 individuals from a plot of 400 m2 were analyzed. The results showed high levels of genetic diversity (H e = 0.405 ± 0003) and moderate levels of gene flow (N m = 2.25) and low genetic differentiation (P < 0.001; 8%). The fine spatial genetic structure showed a random distribution, while the kinship analysis exhibited high genetic similarity among the analyzed individuals. High levels of diversity suggest that the species is not genetically degraded, however, due to its fragmented distribution and high environmental vulnerability, it is suggested for its conservation in situ, priority should be given for immediate protection to the populations of El Relámpago (due to its great genetic diversity), the Panteon and the Orquidiario due to its low genetic diversity and the high vulnerability due to anthropic and environmental disturbance.

Resumen Oreomunnea mexicana es una especie relicta y amenazada, que constituye un elemento arbóreo dominante en el bosque de niebla de la Sierra Juárez, Oaxaca. La especie es emblemática y se encuentra incorporada en la cosmovisión de los habitantes de la región, donde, además, desempeña funciones ecológicas y servicios ecosistémicos muy importantes. El objetivo del presente trabajo fue analizar la diversidad y estructura genética, así como evaluar la estructura genética espacial a escala fina, utilizando marcadores moleculares con fines de conservación in situ. Se utilizaron marcadores dominantes denominados inter simple sequence repeat con los que se analizaron individuos de nueve poblaciones (25 por población) y 120 individuos de una parcela de 400 m2. Los resultados mostraron niveles altos de diversidad genética (H e = 0.405 ± 0003) y moderados de flujo génico (Nm = 2.25) y baja diferenciación genética (P < 0.001; 8%). La estructura genética espacial fina mostró una distribución aleatoria, mientras que el análisis de parentesco exhibió alta similitud genética entre los individuos analizados. Los niveles altos de diversidad sugieren que la especie no se encuentra degradada genéticamente, sin embargo, debido a su distribución fragmentada y alta vulnerabilidad ambiental, se sugiere para su conservación in situ, se dé prioridad para su protección inmediata a las poblaciones de El Relámpago (por su gran riqueza alélica), El Panteón y El Orquidiario debido a su baja diversidad genética y por la alta vulnerabilidad por perturbación antrópica y ambiental.

Resumo: Myracrodruon urundeuva, espécie nativa da Caatinga e de ampla distribuição geográfica, apresenta relevante valor socioeconômico. Objetivou-se avaliar a influência de estresses ambientais sobre a germinação de lotes de diferentes safras de M. urundeuva. Foram testadas as temperaturas constantes de 10 a 40 °C e potenciais osmóticos de 0 a -0,8 MPa (usando-se polietileno glicol 6000) e de 0 a -0,5 MPa (usando-se soluções de NaCl). O delineamento experimental foi inteiramente casualizado com três repetições de 50 sementes em esquema fatorial (safras x intensidade do estresse) para cada estresse abiótico. Os dados de germinação foram então analisados utilizando modelos de tempo térmico, hídrico, hálico (salino), projetando respostas de germinação em cenários climáticos futuros. Os limites térmicos para a germinação das sementes variaram entre 7,4 e 53,3 oC. O limite osmótico base para germinação de sementes em polietileno glicol foi de -0,6 MPa e em NaCl foi de -0,43 MPa. Segundo modelos de cenários futuros de mudanças climáticas, a redução de semanas com precipitação mínima afetará diretamente a germinação de sementes e o recrutamento de plântulas de M. urundeuva. Assim, conclui-se que sementes de M. urundeuva foram tolerantes aos estresses abióticos. Os modelos de tempo térmico, hídrico e hálico foram eficientes para descrever a resposta foram eficientes para descrever a resposta germinativa de sementes, e os modelos climáticos permitiram identificar as respostas germinativas de M. urundeuva em cenários futuros de mudanças climáticas. De acordo com os modelos para clima futuro (RCP 8.5), a redução da precipitação até 2100 afetará diretamente a germinação de sementes e recrutamento de plântulas de M. urundeuva.

Abstract: Myracrodruon urundeuva, a native species from the Brazilian Caatinga, is widely distributed across its endemic region, where it also plays an essential socioeconomic role. The objective of this study was to evaluate the influence of environmental stress on the germination of M. urundeuva seeds harvested in different years (2010 to 2013). Seeds were germinated at constant temperatures between 10 to 40 °C, osmotic potentials from 0 to -0.8 MPa (in polyethylene glycol 6000 solutions), and from 0 to -0.5 MPa (in NaCl solutions). The experiment was conducted according to a completely randomized design, with three replicates of 50 seeds, in a factorial scheme (harvest year x stress intensity) for each environmental stress. Germination data were then analysed using thermal, hydro and halo time models, and future germination responses projected according to climate change scenarios. The germination thermal thresholds ranged from 7.4 to 53.3 oC. The germination base osmotic threshold (using polyethylene glycol) was -0.6 MPa and the base osmotic threshold in NaCl was -0.43MPa. Seeds from different harvest years showed distinct tolerance to environmental stresses. The thermal, hydro and halo-time models were efficient to describe the germinative response of seeds, and the climate models allowed to identify the germination responses of M. urundeuva in future climate. According to the models for future climate (RCP 8.5), the reduction of rainfall by 2100 will directly affect seed germination and seedling recruitment of M. urundeuva.

Abstract: Oreomunnea mexicana(Stand.) J.F. Leroy is a relict species, threatened and a key species for cloud ecosystem functionof the Sierra Juárez, Oaxaca, the most extensive and best conserved in Mexico. This study includes a diagnostic on two critical stages of the process of population regeneration ofO. mexicana. To this end, it analyzed the: 1) production, dispersion, viability and germination of seeds, 2) effect of predation on the growth and survival of the seedlings, and 3) effect of environmental variables (soil, canopy structure and solar radiation) on the regeneration of the species. The study was made from 2014 to 2015 in the cloud forest of Santiago Comaltepec, Oaxaca, Mexico, in two locations (San Bernardo and El Orquidiario). Differences in seed production were found between years and between locations, as well as low seed viability and a high percentage of seed parasitism. The establishment and growth of the seedlings are subject to find suitable microhabitats, since seedlings have specific illumination and soil requirements. The high edaphic specificity faced by the species could be a key factor for its fragmented and discontinuous distribution in Sierra Juárez. Further population regeneration studies are recommended to increase knowledge of the species and thereby achieve its conservation.

Resumen: Oreomunnea mexicana (Stand.) J.F. Leroy es una especie relicto, amenazada, y clave para el funcionamiento del ecosistema de niebla de la Sierra Juárez, Oaxaca, el más extenso y conservado de México. En este estudio se realizó un diagnóstico en dos etapas críticas del proceso de regeneración poblacional de O. mexicana. Para ello, se analizó: 1) la producción, dispersión, viabilidad y germinación de semillas, 2) el efecto de la depredación en el crecimiento y supervivencia de las plántulas, y 3) el efecto de variables ambientales (suelo, estructura del dosel y radiación solar) en la regeneración de la especie. El diagnóstico se realizó de 2014 a 2015 en el bosque de niebla de Santiago Comaltepec, Oaxaca, México, dentro del cual se seleccionaron dos localidades: San Bernardo y El Orquidiario. Se encontraron diferencias en la producción de semillas entre años y entre localidades, además de baja viabilidad y un alto porcentaje de parasitismo en las semillas. El establecimiento y crecimiento de las plántulas están sujetos a encontrar microhábitats adecuados, dado que las plántulas tienen requerimientos específicos de iluminación y de minerales esenciales en el suelo. La alta especificidad edáfica que presenta la especie puede ser factor de su distribución fragmentada y discontinua en la Sierra Juárez. Se recomienda continuar con los estudios de regeneración poblacional para aumentar el conocimiento de la especie y con ello lograr su conservación.

Abstract The demography of Oreomunea mexicana, an endangered species was studied. This species is a Cenozoic relic and is a dominant tree in the cloud mountain forest of Sierra Juárez, Oaxaca. Population structure of four populations were obtained through plots of 400 m2 (20 x 20 m) for the years 2011 and 2016. Through the use of Lefkovitch-type matrices, the finite population growth rate (λ) and an elasticity analysis were obtained for the population of San Bernardo over two time periods (2011 - 2015 and 2015 - 2016). Strong winds of 100 km/h were recorded on March 2016, that increased the mortality within the studied populations, without modifying its population structure in an inverted J-shape. However, the demographic study in San Bernardo showed a λ in decrease for the second period of 0.44 ± 0.009, in compared to a growth of λ (1.101 ± 1.083) found in the first period. The permanence of individuals is the most important demographic parameter in maintaining viability demographic in O. mexicana. The species presented a high sensitivity and vulnerability to extreme environmental changes, with a decrease in population number in a short period of time (2015-2016). Therefore, if it is desired to restore these local populations, is absolutely essential that conservation efforts focus on maintaining and increasing the number of adult individuals in the area in the future.

Resumen Se estudió la demografía de Oreomunnea mexicana, una especie amenazada considerada un relicto del Cenozoico. Esta especie es un elemento arbóreo dominante en el bosque de niebla de La Sierra Juárez, Oaxaca. Se obtuvo la estructura poblacional de cuatro sitios en 2011 y 2016 a través de parcelas de 400 m2 (20 m × 20 m). Por medio del uso de matrices de tipo Lefkovitch se obtuvo la tasa finita de crecimiento poblacional (λ) para la población de San Bernardo, además de un análisis de elasticidad para dos periodos (2011 - 2015 y 2015 - 2016). En marzo de 2016, se registraron fuertes vientos de 100 km/h, lo que incrementó la mortalidad dentro de las poblaciones, sin modificar su estructura poblacional en forma de J invertida. No obstante, el estudio demográfico en San Bernardo mostró una λ en decremento para el segundo periodo de 0.44 ± 0.009, en comparación con una λ en crecimiento de 1.101 ± 1.083 del primer periodo. Se encontró que la permanencia de los individuos es el parámetro demográfico más importante para mantener la estabilidad demográfica de las poblaciones. La especie mostró alta vulnerabilidad a cambios extremos en el ambiente, con un decremento en su número poblacional en un período corto (2015-2016). Por lo anterior, si se desea restaurar estas poblaciones locales, la conservación in situ debe enfocarse a lograr mantener y aumentar a futuro el número de individuos adultos en la zona.

Résumés: L’article s’interroge sur la politique économique internationale que pourrait adopter le gouvernement de Donald Trump. On aborde le mécontentement qu’inspire la mondialisation à certains groupes aux États-Unis, les conséquences que pourrait entraîner la décision de cette puissance d’abandonner l’Accord de partena riat transpacifique et les conditions pour la renégociation prévi sible de l’Accord de libre-échange nord-américain (TLCAN). On cite aussi les matières qu’il faudrait mettre à jour ou ajouter au tlcan, suivant les tendances internationales de la réglementation sur le commerce et l’investissement au XXIe siècle.

Abstracts: This paper evaluates the international economic policy of the United States in the context of the administration of President Donald Trump. The paper analyzes the dissatisfaction with the process of globalization in the United States, the consequences of its abandonment of the Trans-Pacific Partnership Agreement and the potential scenarios raised by the imminent renegotiation of the North American Free Trade Agreement. The main spheres and disciplines that need to be updated or added to the nafta are analyzed on the basis of international trends in trade and invest ment regulation in the twenty-first century.

Resumen: Este artículo evalúa la política económica internacional de Esta dos Unidos en lo que atañe a la administración del presidente Donald Trump. El artículo analiza el descontento con el proceso de la globalización en Estados Unidos, las consecuencias del aban dono por parte de ese país del Acuerdo Transpacífico de Asocia ción Económica y los potenciales escenarios ante la inminente renegociación del Tratado de Libre Comercio de América del Norte. Se analizan prospectivamente los principales ámbitos y dis ciplinas que habrán de actualizarse o sumarse en el TLCAN con base en las tendencias internacionales en la regulación del comer cio e inversión del siglo XXI.

G.L. Arzate-Vázquez, F.A. Castrejón-Pineda, R. Rosiles-Martínez, S. Carrillo-Pita, S. Angeles-Campos, and E. Vargas-Bello-Pérez. 2016. Effect of genus and growth stage on the chemical and mineral composition of tropical grasses used to feed dairy cows. Cien. Inv. Agr. 43(3): 476-485. In tropical production systems, dairy cows are rarely supplemented with minerals, which often lead to mineral imbalances. Grasses grown together in the same soil type and sampled at the same growth stage can vary widely in chemical and mineral composition; therefore, the objective of this study was to characterize the chemical and mineral composition of Urochloa spp., Megathyrsus spp., and Andropogon spp. at three different stages of growth in the same soil type. The content of dry matter (DM; g 100 g-1) was higher (P<0.05) in Urochloa spp. than in Andropogon spp. and Megathyrsus spp. Hemicellulose, non-fiber carbohydrates and slowly degraded true protein contents were higher (P≤0.05) in Andropogon spp. than in Urochloa spp. and Megathyrsus spp. Ether extract, crude protein, rapidly degraded true protein and unavailable protein contents were not affected by genus, whereas ether extract, ash, neutral detergent fiber, non-fiber carbohydrates, rapidly degraded true protein and unavailable protein contents were not affected by growth stage. Compared with Urochloa spp. and Andropogon spp., Megathyrsus spp. had higher (P≤0.05) contents of Na and Mg, intermediate (P≤0.05) contents of Mn and lower (P≤0.05) contents of Zn. P, Na, and K contents were affected by growth stage. Compared with Megathyrsus spp. and Andropogon spp., Urochloa spp. was higher (P≤0.05) in P and Na contents. Results from this study may be useful in predicting the nutrient and mineral supply from forages in dairy production systems in tropical areas.

G.L. Arzate-Vázquez, F.A. Castrejón-Pineda, R. Rosiles-Martínez, S. Carrillo-Pita, S. Angeles-Campos y E. Vargas-Bello-Pérez. 2016. Efecto del género y etapa de crecimiento sobre la composición química y mineral de pastos tropicales utilizados para alimentar vacas lecheras. Cien. Inv. Agr. 43(3): 476-485. En los sistemas de producción tropical, las vacas lecheras rara vez se suplementan con minerales y frecuentemente esto provoca un desequilibrio mineral. Los pastos que crecen en las mismas condiciones de suelo y que son muestreados en la misma etapa de crecimiento pueden variar en su composición química y mineral, por lo tanto el objetivo de este estudio es caracterizar la composición química y mineral de Urochloa spp., Megathyrsus spp., and Andropogon spp., en tres etapas distintas de crecimiento con las mismas condiciones de suelo. El contenido de materia seca (g 100 g-1) fue mayor (P≤0.05) en Urochloa spp., que en Andropogon spp., y Megathyrsus spp. Los contenidos de hemicelulosa, carbohidratos no estructurales y proteína verdadera de degradación lenta, fueron mayores en (P≤0.05) Andropogon spp., que en Urochloa spp., y Megathyrsus spp. Los contenidos de extracto etéreo, proteína cruda, proteína verdadera de rápida degradación no fueron afectados por el género del pasto; mientras que el extracto etéreo, ceniza, fibra detergente neutra, contenido celular, carbohidratos no estructurales, proteína verdadera de rápida degradación y proteína no degradables tampoco fueron afectados por la etapa de crecimiento de los pastos. En comparación con Urochloa spp., y Andropogon spp., Megathyrsus spp., tuvo mayor (P≤0.05) cantidad de P, Na y Mg, valores intermedios (P≤0.05) para Mn y valores menores (P≤0.05) para Zn. P, Na y K fueron afectados por la etapa de crecimiento de los pastos. Comparado con Megathyrsus spp., y Andropogon spp., Urochloa spp., presentaron contenidos más altos (P≤0.05) de P y Na. Los contenidos de K fueron menores (P≤0.05) en Andropogon spp., que aquellos observados en Megathyrsus spp., y Urochloa spp. Los resultados de este estudio podrían ser utilizados para calcular o predecir el consumo de nutrientes y minerales de vacas lecheras en sistemas de pastoreo tropical.

ABSTRACT Objectives. To describe the clinical characteristics, lethality, antibiotic susceptibility, and serotype distribution of pneumococcal meningitis in pediatric patients in Lima, Peru. Materials and Methods. A case series of pneumococcal meningitis in children less than 16 years of age from two prospective, multicenter, passive surveillance studies of invasive pneumococcal diseases held in Lima-Peru from 2006 to 2008 and 2009 to 2011. Results. We report 44 pneumococcal meningitis episodes; 68.2% of them were in children less than 2 years old. The overall case fatality rate was 32.6%; 92.9% of fatal cases were in children less than 2 years of age (p<0.05). Malnutrition was associated with fatal cases (p<0.05). 64.3% of fatal cases died within the first two days. 41.9% of pneumococcal isolates were resistant to penicillin, 23.3% were intermediate resistant to ceftriaxone (none were highly resistant) and 9.3% were resistant to chloramphenicol. The most common serotypes were 6B, 14, 19F and 23F, which accounted for 68.3% of all strains; 84.1% of strains were PCV13 serotypes. Conclusions. Pneumococcal meningitis continues to be a lethal disease, especially in children less than 2 years of age. Since almost two third of lethal cases lead to death within the first 48 hours, prompt diagnosis and management is critical, as well as assurance of immunization with pneumococcal vaccine.

RESUMEN Objetivos. Describir las características clínicas, letalidad, susceptibilidad antibiótica y distribución de serotipos de meningitis neumocócica en pacientes pediátricos de Lima, Perú. Materiales y Métodos. Serie de casos de meningitis neumocócica en niños menores de 16 años. Los datos fueron obtenidos de dos estudios multicéntricos prospectivos, de vigilancia pasiva de enfermedad neumocócica invasiva realizados en Lima-Perú desde los años 2006 al 2008, y del 2009 al 2011. Resultados. Reportamos 44 episodios de meningitis neumocócica; 68,2% fueron en niños menores de 2 años. La tasa de letalidad fue 32,6; y 92,9% de los casos letales ocurrieron en niños menores de dos años (p<0,05). La desnutrición estuvo asociada a los casos letales (p<0,05). El 64,3% de los casos fatales murieron dentro de los 2 primeros días. El 41,9% de los cultivos con neumococo fueron resistentes a la penicilina, 23,3% mostró resistencia intermedia a ceftriaxona (ninguno mostró resistencia completa) y 9,3% mostró resistencia a cloranfenicol. Los serotipos más frecuentes fueron 6B, 14, 19F y 23F, los cuales constituyeron el 68,3% de todas las cepas; 84,1% de las cepas encontradas están incluidas en los serotipos de la vacuna 13 valente. Conclusiones. La meningitis neumocócica continúa siendo una enfermedad letal, especialmente en niños menores de 2 años. Dado que aproximadamente dos tercios de los casos letales fallecen en las primeras 48 h, es crítico un diagnóstico y tratamiento oportuno, así como asegurar el cumplimiento de la inmunización con la vacuna neumocócica.

ABSTRACT Objective To 1) describe the correlation between the zones of inhibition in 1-µg oxacillin disk diffusion (ODD) tests and penicillin and ceftriaxone minimum inhibitory concentrations (MICs) of meningeal and non-meningeal strains of Streptococcus pneumoniae and 2) evaluate the usefulness of the ODD test as a predictor of susceptibility to penicillin in S. pneumoniae and as a quick and cost-effective method easily implemented in a routine clinical laboratory setting. Methods S. pneumoniae isolates from healthy nasopharyngeal carriers less than 2 years old, obtained in a multicentric cross-sectional study conducted in various Peruvian hospitals and health centers from 2007 to 2009, were analyzed. Using Clinical and Laboratory Standards Institute (CLSI) breakpoints, the correlation between the zones of inhibition of the ODD test and the MICs of penicillin and ceftriaxone was determined. Results Of the 571 S. pneumoniae isolates, 314 (55%) showed resistance to penicillin (MIC ≥ 0.12 µg/mL) and 124 (21.7%) showed resistance to ceftriaxone (MIC ≥ 1 µg/mL). Comparison of the ODD test zones of inhibition and the penicillin MICs, using the CLSI meningeal breakpoints, showed good correlation (Cohen’s kappa coefficient = 0.8239). Conclusions There was good correlation between ODD zones of inhibition and penicillin meningeal breakpoints but weak correlation between the ODD results and non-meningeal breakpoints for both penicillin and ceftriaxone. Therefore, the ODD test appears to be a useful tool for predicting penicillin resistance in cases of meningeal strains of S. pneumoniae, particularly in low- and middle- income countries, where MIC determination is not routinely available.

RESUMEN Objetivo 1) Describir la correlación entre las zonas de inhibición observadas en la prueba de difusión con discos de oxacilina de 1 µg y la concentración inhibitoria mínima (CIM) de penicilina y ceftriaxona frente a cepas meníngeas y no meníngeas de Streptococcus pneumoniae y 2) evaluar si la prueba de difusión con discos de oxacilina permite predecir la sensibilidad de S. pneumoniae a la penicilina y sirve como método rápido y eficaz en función de los costos, y resulta fácil de aplicar en los laboratorios clínicos ordinarios. Métodos Se analizaron colonias de S. pneumoniae aisladas de la nasofaringe de portadores sanos menores de 2 años obtenidas en un estudio transversal multicéntrico realizado en diversos hospitales y centros de salud del Perú entre los años 2007 y 2009. Se determinó la correlación entre las zonas de inhibición observadas en la prueba de difusión con discos y la CIM de la penicilina y la ceftriaxona utilizando los valores críticos definidos por el Instituto de Estándares Clínicos y de Laboratorio. Resultados De las 571 colonias aisladas de S. pneumoniae, 314 (55 %) presentaron resistencia a la penicilina (CIM ≥ 0,12 µg/ml) y 124 (21,7%), resistencia a la ceftriaxona (CIM ≥ 1 µg/ml). Se observó una buena correlación (coeficiente κ de Cohen = 0,8239) entre las zonas de inhibición de la prueba de difusión con discos y la CIM de la penicilina utilizando los valores críticos del Instituto respecto de las cepas meníngeas. Conclusiones Se encontró una buena correlación entre las zonas de inhibición de la prueba de difusión con discos y los valores críticos de CIM de la penicilina respecto de las cepas meníngeas, pero una correlación débil entre los resultados de la prueba de difusión y los valores críticos tanto de la penicilina como de la ceftriaxona respecto de las cepas no meníngeas. Por consiguiente, la prueba de difusión con discos es un método de utilidad para predecir la resistencia a la penicilina de las cepas meníngeas de S. pneumoniae, en particular en los países de ingresos bajos y medianos, donde no suele ser posible determinar la CIM.