Caracterización molecular de B-Lactamasas de espectro extendido en cepas de escherichia coli causantes de infección urinaria en pacientes inmunocomprometidos / Molecular characterization of extended spectrum B-Lactamases in strains of escherichia coli causing urinary infection in immunocompromised patients

Introducción. La Infección del Tracto Urinario (ITU) es la infección bacteriana que más se diagnostica en el mundo y su agente causal más frecuente es Escherichia coli (E. coli), bacteria que ha adquirido importancia por su capacidad de producir betalactamasa de espectro extendido (BLEE), lo cual dificulta su tratamiento y hace más frecuentes las infecciones recurrentes y recidivantes incluyendo sus complicaciones, sobretodo en pacientes inmunocomprometidos.Objetivo. Identificar pacientes con ITU producidas por E. coli productoras de BLEE y evaluar su espectro antibacteriano y molecular.Material y métodos. Estudio longitudinal y prospectivo realizado con muestras urinarias de 53 pacientes de la Caja Nacional de Salud en La Paz-Bolivia. Se aisló como agente causal a E. coli en el 72% de las muestras, de estas, 35 presentaron fenotipo BLEE sensibles a imipenem, gentamicina y nitrofurantoina (100%) y amikacina (94%). Los ensayos de fenotipificación reportaron predominio del tipo PhP-2 y los filogenéticos (PCR y secuenciación) identificaron predominio de bla CTX-M-15 asociada a bla TEM-1.Conclusión. Los fármacos de primera línea para el tratamiento de la ITU no son adecuados, haciendo a los pacientes más susceptibles a infecciones recurrentes y recidivantes. Se deben identificar precozmente y tratar eficazmente las ITU producidas por cepas de E. coli productoras de BLEE.

Heterophilic antibodies in sera from individuals without loxoscelism cross-react with phospholipase D from the venom of Loxosceles and Sicarius spiders

Background Loxoscelism is a severe human envenomation caused by Loxosceles spider venom. To the best of our knowledge, no study has evaluated the presence of antibodies against Loxosceles venom in loxoscelism patients without treatment with antivenom immunotherapy. We perform a comparative analysis for the presence of antibodies capable of recognizing Loxosceles venom in a group of patients diagnosed with loxoscelism and in a group of people without loxoscelism. Methods The detection of L. laeta venom, Sicarius venom and recombinant phospholipases D from Loxosceles (PLDs) in sera from people with loxoscelism (Group 1) and from healthy people with no history of loxoscelism (Group 2) was evaluated using immuno-dot blot, indirect ELISA, and Western blot. Results We found naturally heterophilic antibodies (IgG-type) in people without contact with Loxosceles spiders or any clinical history of loxoscelism. Either serum pools or single sera from Group 1 and Group 2 analyzed by dot blot tested positive for L. laeta venom. Indirect ELISA for venom recognition showed titles of 1:320 for Group 1 sera and 1:160 for Group 2 sera. Total IgG quantification showed no difference in sera from both groups. Pooled sera and purified IgG from sera of both groups revealed venom proteins between 25 and 32 kDa and the recombinant phospholipase D isoform 1 (rLlPLD1), specifically. Moreover, heterophile antibodies cross-react with PLDs from other Loxosceles species and the venom of Sicarius spider. Conclusions People without contact with the spider venom produced heterophilic antibodies capable of generating a cross-reaction against the venom of L. laeta and Sicarius spiders. Their presence and possible interference should be considered in the development of immunoassays for Loxosceles venom detection.

Heterophilic antibodies in sera from individuals without loxoscelism cross-react with phospholipase D from the venom of Loxosceles and Sicarius spiders

Loxoscelism is a severe human envenomation caused by Loxosceles spider venom. To the best of our knowledge, no study has evaluated the presence of antibodies against Loxosceles venom in loxoscelism patients without treatment with antivenom immunotherapy. We perform a comparative analysis for the presence of antibodies capable of recognizing Loxosceles venom in a group of patients diagnosed with loxoscelism and in a group of people without loxoscelism. Methods The detection of L. laeta venom, Sicarius venom and recombinant phospholipases D from Loxosceles (PLDs) in sera from people with loxoscelism (Group 1) and from healthy people with no history of loxoscelism (Group 2) was evaluated using immuno-dot blot, indirect ELISA, and Western blot. Results We found naturally heterophilic antibodies (IgG-type) in people without contact with Loxosceles spiders or any clinical history of loxoscelism. Either serum pools or single sera from Group 1 and Group 2 analyzed by dot blot tested positive for L. laeta venom. Indirect ELISA for venom recognition showed titles of 1:320 for Group 1 sera and 1:160 for Group 2 sera. Total IgG quantification showed no difference in sera from both groups. Pooled sera and purified IgG from sera of both groups revealed venom proteins between 25 and 32 kDa and the recombinant phospholipase D isoform 1 (rLlPLD1), specifically. Moreover, heterophile antibodies cross-react with PLDs from other Loxosceles species and the venom of Sicarius spider. Conclusions People without contact with the spider venom produced heterophilic antibodies capable of generating a cross-reaction against the venom of L. laeta and Sicarius spiders. Their presence and possible interference should be considered in the development of immunoassays for Loxosceles venom detection.(AU)

Composición bioquímica y toxicidad de colonias comestibles de la cianobacteria andina Nostoc sp. Llayta / Biochemical composition and toxicity of edible colonies of the cyanobacterium Nostoc sp. Llayta

RESUMEN Llayta es el nombre asignado a la biomasa seca de macrocolonias de una cianobacteria filamentosa, clasificada como Nostoc sp. Llayta crece en humedales andinos de Sudamérica y ha sido considerada como un ingrediente alimenticio desde tiempos precolombinos. Este estudio pretende contribuir a la definición de la calidad nutritiva de la Llayta, proporcionando información sobre su composición bioquímica e identificar aspectos críticos de interés toxicológico. Los resultados mostraron que el 60% del total de sus aminoácidos son indispensables, contenía un 2% de lípidos totales, 32% del total de ácidos grasos eran poliinsaturados, la vitamina E fue la más abundante (4,3 mg%), el contenido de polifenoles totales es 64 mg equivalentes de ácido gálico, su actividad antioxidante es 17,4 μmoles equivalentes de Trolox, la fibra total fue el 56% del peso seco y presentó un contenido promedio de arsénico total de 9,2 ± 5,4 ppm. Esta cianobacteria no es productora de microcistina, por lo que las colonias de la Llayta podrían considerarse inocua para el consumo humano.

ABSTRACT Llayta is the name assigned to the dry biomass of macrocolonies of a filamentous cyanobacterium classified as Nostoc sp. Llayta grows in the Andean wetlands of South America and has been considered a food ingredient since pre-Columbian times. This work is an effort to contribute to define the nutritional quality of Llayta providing information on its biochemical composition and to identify key toxicological aspects. The results indicated that 60% of its aminoacids were indispensable, total lipids were 2% of dry weight, polyunsaturated fatty acids were 32% of total fatty acids, vitamin E was the most abundant (4.3 mg%), total polyphenols were 64 mg (equivalent to galic acid), antioxidant activity was 17.4 μmoles (equivalent to Trolox), total fiber was 56% of dry weight and accumulated 9.2 ± 5.4 ppm of total arsenic. Since Nostoc sp. Llayta is a cyanobacterium strain that does not synthesize the cyanotoxin microcystin, the Llayta colonies can be considered innocuous for human consumption.

Detección de genes de virulencia en cepas de Enterococcus faecalis susceptibles y resistentes a aminoglucósidos / Detection of virulence genes in aminoglycoside susceptible and resistant Enterococcus faecalis

Background: Enterococcus spp. is an important cause of nosocomial infections A number of virulence factors that may enhance its ability to colonize have been described. Enterococcus is capable of acquiring resistance genes, including high-level resistance (HLR) to aminoglycoside antibiotics. Aim: to investigate the prevalence of genes encoding virulence factors in aminoglycosides susceptible and resistant E. faecalis. Materials and Methods: A total of 80 E. faecalis isolates from clinical (n: 52) and poultry samples (n: 28) were included in this study. Bacterial identification was performed by biochemical tests and phenotypificationwas done using the Phene-PlateTM system. Susceptibility to different antimicrobial agents was determined by the agar dilution method. Virulence genes aceI, agg, gelE and efaA were detected by multiplex PCR. Results: All isolates were susceptible to vancomycin and ampicillin. HLR to gentamicin (13.5%) and streptomycin (9.6%) was detected only in clinical isolates. The phenotyping revealed a great diversity of PhP-types, but only one clone with 7 strains of similar characteristics was found. The efaA gen was detected in 100% of the isolates. aceI gene was present in 94.2% and 75%, agg gene in 73.1%, and 67.9%, and gelE gene in 57.5% and 28.6% of the clinical and chicken isolates, respectively. Only 6 strains with HLR to aminoglycosides, belonging to the same phenotype, had the aceI, agg, gelE and efaA genes. Conclusions: E. faecalis with virulence genes and HLR to aminoglycosides were isolated from clinical and chicken samples in Antofagasta. More studies will be necessary to establish an association.

Antecedentes: Enterococcus spp. es una causa importante de infecciones nosocomiales, tanto en Chile como internacional. Se han descrito una serie de factores de virulencia en este microorganismo, que pueden, por ejemplo, aumentar su habilidad para colonizar. Enterococcus tiene capacidad de adquirir genes de resistencia, entre ellos la resistencia de alto nivel (RAN) a los antimicrobianos aminoglucósidos. Objetivo: Investigar la prevalencia de genes de virulencia en cepas de E. faecalis susceptibles y resistentes a aminoglucósidos. Material y Métodos: Un total de 80 cepas de E. faecalis aisladas de muestras clínicas (n: 52) y pollos (n: 28) se incluyeron en este estudio. La identificación se hizo por pruebas bioquímicas y se tipificaron por el sistema Phene-PlateMR. La susceptibilidad a diferentes antimicrobianos fue realizada por test de dilución en agar. Los genes de virulencia aceI, agg, gelE y efaA fueron investigados por RPC múltiple. Resultados: Todas las cepas de E. faecalis fueron susceptibles a vancomicina y ampicilina. Un 13,5% de las cepas clínicas presentaron resistencia de alto nivel a gentamicina y 9,6% a estreptomicina. La tipificación reveló una gran diversidad de fenotipos, pero se encontró un clon con 7 cepas de características similares. El gen efaA estaba presente en 100% de las cepas, gen aceI en 94,2 y 75%, gen agg 73,1 y 67,9% y gen gelE 57,5 y 28,6% de las cepas clínicas y de pollos, respectivamente. Seis cepas con resistencia de alto nivel a aminoglucósidos, que pertenecían a un mismo fenotipo exhibieron los genes efaA, aceI, agg y gelE juntos. Conclusiones: Cepas de E. faecalis que albergan genes de virulencia y con resistencia de alto nivel a aminoglucósidos fueron aisladas de muestras clínicas y de pollos en Antofagasta. Se requieren mayores estudios para establecer una asociación entre estos factores.

Caracterización fenotípica y genotípica de la resistencia a meticilina de cepas de Staphylococcus aureus aisladas en Antofagasta / Phenotypic and genotypic characterization of methicillin resistance in strains of Staphylococcus aureus isolated in Antofagasta

Staphylococcus aureus resistant to methicillin (SARM) has been associated with nosocomial infections due to its capacity to develop resistance to multiple antibiotics. There is little information about the SARM which are found in the hospital services of Antofagasta. We studied the phenotypic and genotypic characteristics of methicillin resistance in 38 strains of S. aureus isolated in Antofagasta, identified by coagulase and API Staph tests and by a biochemical test (Ph-system). The susceptibility to antibiotics was studied using the agar dilution technique, identifying SARM strains with discs of oxacillin. Beta-lactamase with nitrocephine, and the gene mecA by means of PCR. Eighty nine percent (34 strains) were SARM with a high resistance to ampicillin, penicillin, erythromycin, claritromycin. gentiamycin, amikacine and ciprofloxacine. All isolates were susceptible to vancomycin and rifampicin. Beta-lactamase was demonstrated in 79% of the SARM strains. Strain typing and resistance patterns revealed a great diversity of PhP-types and antibiotypes in the isolates. Ninety seven percent of the SARM strains had the gene mecA. One PhP-type (C6) was dominant (5 SARM strains) all had the mecA gene, produced beta lactamase and had the same pattern of antibiotic resistance. We conclude that the dominant phenotypes of SARM strains which have the mecA gene and multiple resistance to antibiotics are present in the hospitals of Antofagasta, and sound the alert on the risk of nosocomial transmission of epidemic clones of SARM.

Staphylococcus aureus resistentes a meticilina (SARM) han sido asociados con infecciones nosocomiales por su capacidad para desarrollar resistencia a múltiple antibióticos, existiendo escasa información acerca de SARM que están circulando en los servicios hospitalarios de Antofagasta. Se estudió características fenotIpicas y genotípicas de la resistencia a meticilina en 38 cepas de S. aureus aisladas en Antofagasta, identificadas por tests de coagulasa y API Staph y por tipificación bioquímica (Ph-Sistem). La susceptibilidad a antibióticos se realizo por técnica de dilución en agar, las cepas SARM fueron identificadas con discos de oxacilina, beta-lactamasa por nitrocefina y gen mecA fue detectado pot PCR. El 89% (34 cepas), fueron SARM con una alta resistencia a ampicilina, penicilina, eritromicina, gentamicina, amikacina y ciprofloxacino. Todos los aislados fueron susceptibles a vancomocina y rifampicina. Beta lactamasa fue demostrada en 79% de las cepas SARM. La tipificación y los patrones de resistencia revelaron una alta diversidad de PhP tipos y antibioticos en los aislamientos. El 97% de las cepas SARM albergaban el gen mecA. Un PhP tipo (C6) fue dominante. (5 cepas SARM), todos presentando el gen mecA, produciendo beta lactamasa y mostrando el mismo patrón de resistencia antibiótica. Se concluye que los fenotipos dominantes de cepas SARM que albergan el gen mecA y resistencia múltiples alos antibióticos están circulando en los hospitales de Antofagasta, alertando sobre el riesgo de transmisión intranosocomial de clones epidémicos de SARM.

Enteroparasitosis en alumnos de educación básica de la ciudad de Antofagasta (2006 - 2007) / Enteroparasitism in students of basic education in two municipal schools of the city of Antofagasta (2006-2007)

In the northern part of Chile, due to its geoclimatic characteristics, enteroparasitosis in school children is mainly due to protozoos is such as Giardiosis and Blastocystosis, and Enterobiosis among helminthic infections. During the years 2006 and 2007, we made an enteroparasitosis survey of 92 school children in grades 1 to 8 in two municipal schools of Antofagasta. The global prevalence rate of parasites and commensals was 83.69%. We found frequencies of 68.48% for Blastocystis hominis, 8.70% for Giardia duodenalis, and 23.91% for Enterobius vermicularis. The frequencies for commensals were 18.48% for Entamoeba coli, 16.30% for Endolimax nana, 5.43% for Chilomastix mesnili and 3.26% for Lodamoeba bütschlii. We conclude that the frequency of infection by parasites and commensals among school children is related to the deficient sanitary conditions present in some sectors of the city of Antofagasta, associated with socioeconomic and cultural factors of the population.

En el norte de Chile por las características geoclimáticas, las enteroparasitosis en escolares se centra principalmente en protozoosis como la Giardiosis y Blastocistosis y la Enterobiosis entre las helmintiasis. Durante los años 2006 y 2007 se encuestó enteroparasitológicamente a 92 escolares que cursaban entre 1° y 8° básico en dos escuelas municipales de Antofagasta. La tasa de prevalencia global por parásitos y comensales fue de 83,69%. Con indicadores de 68,48% para Blastocystis hominis y 8,70% para Giardia duodenalis, y de 23,91% para Enterobius vermicularis. Entre los comensales se encontró Entamoeba coli (18,48%), Endolimax nana (16,30%), Chilomastix mesnili (5,43%) y Iodamoeba bütschlii (3,26%). Se concluye que la frecuencia de infecciones por parásitos y comensales entre los escolares estaría relacionada con las condiciones sanitarias deficitarias presentes en algunos sectores de la ciudad de Antofagasta, asociadas a factores socioeconómicos y culturales de la población.

Evaluación experimental de la eficiencia de una pintura repelente para arañas del género Loxosceles / Effectiveness of a repellent paint against the spider Loxosceles laeta

Background: Loxoscelism is a severe reaction to the bite of the spider Loxosceles laeta. In recent years, a paint with repellent properties has been promoted in the commerce. However, there are no reports of experiments evaluating its effectiveness. Aim: To evaluate experimentally the repellent properties of a paint against Loxosceles laeta. Material and methods: Males, females and nymphs of L laeta were deposited in cockpits that allow the free displacement of the spider. Half of the cockpit was covered with repellent paint. Daily observations during one week, determined how frequently the spiders occupied the space covered with repellent paint. The experiments were run in triplicate. Results: No statisticaldifferences in the occupancy of spaces covered with repellent paint or not covered with it were observed for nymphs (87% and 67%, respectively), males (72% and 77%, respectively) orfemales (91% and 84%, respectively). Conclusions: The tested paint does not have a repellent action against the spider Loxosceles laeta.

Diterpenoids from Azorella compacta (Umbelliferae) active on Trypanosoma cruzi

The anti-Trypanosoma cruzi activity of natural products isolated from Azorella compacta was evaluated, with particular emphasis on their effect against intracellular amastigotes. Five diterpenoids from A. compacta derived from mulinane and azorellane were isolated and identified. Only two products, named azorellanol (Y-2) and mulin-11,3-dien-20-oic acid (Y-5), showed trypanocidal activity against all stages of T. cruzi including intracellular amastigotes. At 10 æM, these compounds displayed a strong lytic activity. It ranged from 88.4 ± 0.6 to 99.0 ± 1 percent for all strains and stages evaluate, with an IC50 /18 h values of 20-84 æM and 41-87 æM, respectively. The development of intracellular amastigotes was also inhibited by nearly 60 percent at 25 æM. The trypanocidal molecules Y-2 and Y-5 did show different degrees of cytotoxicity depending on the cell line tested, with an IC50 /24 h ranging from 33.2 to 161.2 æM. We evaluated the effect of diterpenoids against intracellular T. cruzi forms by immunofluorescent identification of a specific membrane molecular marker (Ssp-4 antigen) of the T. cruzi amastigote forms. The accuracy and reproducibility of the measurements were found to be outstanding when examined by confocal microscopy

A novel reiterated family of transcribed oligo(A)-terminated, interspersed DNA elements in the genome of Trypanosoma cruzi

We report the molecular characterization of a novel reiterated family of transcribed oligo(A)-terminated, interspersed DNA elements in the genome of Trypanosoma cruzi. Steady-state level of transcripts of this sequence family appeared to be developmentally regulated, since only in the replicative forms the parasite showed expression of related sequences with a major band around 3 kb. The presence of frame shifts or premature stop codons predicts that transcripts are not translated. The sequence family also contains truncated forms of retrotransposons elements that may become potential hot spots for retroelement insertion. Sequences homologous to this family are interspersed at many chromosomes including the subtelomeric regions

Nuevos casos de infección humana por diphyllobothrium pacificum Nybelin 1931, Margolis 1956 en Chile y su probable relación con el fenómeno de El Niño 1975-2000 / New cases of diphyllobothrium pacificum Nybelin 1931, Margolis 1956 human infection in north of Chile probably related with El Niño phenomenon 1975-2000

The effecto of El Niño/ENSO on terrestrial atmosphere appears to be extremelly clear. However there are outstanding evidences showing its effect on humans and their activities. In fact, prevalence of some parasitic infections have increased during El Niño phenomenon. The reasons for that are the migrations of sylvatic mammals, fishes and birds as well as by environmental contamination. In this report, we show evidence respect of new cases of human infection by Diphyllobothrium pacificum clearly associated with a cyclic manifestation of El Niño in the Chilean Pacific coast during 1975-2000

Actividad de diterpenoides de azorella compacta, llareta, sobre amastigotes de trypanosoma cruzi / Activity of dipernoids isolated from azorella compacta, llareta, on trypanosoma cruzi amastigotes

The trypanocidad activity against amastigote forms of SPA-14, Tulahuen and G strains and CL Brener clone of Trypanosoma cruzi of diterpenoids isolated from Azorella compacta. Phil. (Llareta), a plant with ethnomedicinal prestige from prespanish age, was investigated. Amastigocidal activity was shown in azorellanol (2), diterpene isolated by first time, with an inhitory concentration 50 (IC) that varied between 60 M (CL Brener clone) and 84 M (SPA-14 strain), and in mulin -11,13 -dien-20-oico acid (5) with IC between 41 µM (G strain) and 87 mM (CL Brener clone). The cytotoxicity levels of both compounds against Hela and Vero cells and macrophages J144 are lower than nifurtimox and similar to gentian violet

Estudio epidemiológico de la pediculosis capitis y sarna en escolares básicos de Antofagasta, Chile, 1995 / Epidemiological study of pediculosis capitis and scabies in schoolchildren from Antofagasta, Chile, 1995

In order to contribute to a better knowledge of the pediculosis capitis and scabies during March-December 1995, 1122 primary schoolchildren under 14 years of age in the city-port of Antofagasta in northern Chile (20º South lat.), were examined. A total of 285 (25.4 percent) were found to be infested with Pediculus humanus capitis and only 20 (1.8 percent) with Sarcoptes scabiei. In general the rates of infestation to both ectoparasitic diseases were higher in groups of younger schoolchildren, also higher in women than in men and in those groups with high indexes of crowding and ignorance of the transmission mechanism of pediculosis capitis and scabies

Estado actual de la seroprevalencia de la infección chagásica humana y canina en la comuna de San Pedro de Atacama, II Región de Antofagasta en Chile 1995 / Present status of seroprevalence of canine and human chagasic infection in San Pedro de Atacama, II Región, Antofagasta, Chile 1995

In order to assess the impact of a control program against triatoma infestans launched in 1988, based on insecticide spraying of dwellings, a serological survey for chagasic infection was carried out during 1995 in three localities from San Pedro de Atacama county (22º55' south lat., 68º12' west long.), II Region of Antofagasta in northern Chile. Blood samples from 531 children and adolescents and 65 dogs were subjected to ELISA test and indirect inmunofluorescent test for Chagas's disease respectively. Tests resulted positive in 12 (2,3 percent) persons, all above 5 years old, in contrast with the 16,8 percent serological positivity observed in 1985. Three (4,6 percent) dogs (two 0-12 months old) resulted positive. These results indicate that dwellings sprayings with long-term activity insecticides against T. infestans is a good tool to prevent new human infections with T. cruzi. However, active vector transmissiom among domestic animals (canines) could be recently acquired.