The cuticular hydrocarbons of the Triatoma sordida species subcomplex (Hemiptera: Reduviidae)

The cuticular hydrocarbons of the Triatoma sordida subcomplex (Hemiptera: Reduviidae: Triatominae) were ana- lysed by gas chromatography and their structures identified by mass spectrometry. They comprised mostly n-alkanes and methyl-branched alkanes with one-four methyl substitutions. n-alkanes consisted of a homologous series from C21-C33 and represented 33-45% of the hydrocarbon fraction; n-C29 was the major component. Methyl-branched alkanes showed alkyl chains from C24-C43. High molecular weight dimethyl and trimethylalkanes (from C35-C39) represented most of the methyl-branched fraction. A few tetramethylalkanes were also detected, comprising mostly even-numbered chains. Several components such as odd-numbered 3-methylalkanes, dimethylalkanes and trimethylalkanes of C37 and C39 showed patterns of variation that allowed the differentiation of the species and populations studied. Triatoma guasayana and Triatoma patagonica showed the most distinct hydrocarbon patterns within the subcomplex. The T. sordida populations from Brazil and Argentina showed significantly different hydrocarbon profiles that posed concerns regarding the homogeneity of the species. Triatoma garciabesi had a more complex hydrocarbon pattern, but it shared some similarity with T. sordida. The quantitative and qualitative variations in the cuticular hydrocarbons may help to elucidate the relationships between species and populations of this insect group.Instituto de Investigaciones Bioquímicas de La Plat

Hidrocarburos cuticulares de triatominos: su aplicación como marcadores taxonómicos

La subfamilia Triatominae (Hemiptera: Reduvidae), comprende un grupo de insectos hematófagos transmisores de la Enfermedad de Chagas, endemia latinoamericana que afecta cerca de 10 millones de personas, causada por el protozoo flagelado Trypanosoma cruzi. Dadas las dificultades en el desarrollo de una vacuna contra la enfermedad, todos los esfuerzos están volcados al control de los triatominos, como insectos vectores. Los triatominos colonizan vivienda humana (hábitat doméstico), así como los ambientes próximos a ella (hábitat peridoméstico), con mayor o menor grado de adaptación dependiendo de la especie en consideración. Las especies asociadas al hombre suelen mostrar una amplia distribución geográfica, en parte como resultado de su transporte pasivo en los enseres domésticos durante las migraciones humanas. Se ha agrupado a las más de 130 especies que integran la subfamilia en distintos complejos y subcomplejos en base a similitudes morfológicas y de distribución geográfica, entre otras. El subcomplejo Triatoma sordida, incluído dentro del complejo T. infestans, está integrado por las especies T. sordida, T. garciabesi, T. guasayana y T. patagonica distribuidas diferencialmente en el cono sur de América del Sur (Argentina, Bolivia, Brasil y Paraguay). Se encuentran principalmente en los ambientes silvestres y peridomésticos y tienen una alta tasa de infección con T. cruzi. Suelen colonizar la vivienda humana tras la erradicación de T. infestans y T. brasiliensis, por lo que dentro de los programas de control se las considera especies secundarias y potencialmente riesgosas. La variabilidad en diversas características fenotípicas así como la posibilidad de obtener descendencia viable en los cruces experimentales ha llevado a dudar del estatus específico de dos de sus integrantes, T. garciabesi y T. patagonica. Asimismo, se ha sugerido que T. sordida podría estar integrada por dos especies crípticas. Las tres principales especies vectoras de la enfermedad son T. dimidiata, T. infestans y Rhodnius prolixus. Dentro del género Triatoma, la especie con mayor capacidad vectorial en América del Norte y Central es T. dimidiata. Con una alta tasa de infección con T. cruzi , esta especie tiene una alta adaptabilidad a diversas condiciones climáticas y coloniza fácilmente los ambientes peridoméstico y doméstico a partir de sus reservorios silvestres, pudiendo encontrársela incluso en grandes ciudades. De origen centroamericano, actualmente tiene una amplia distribución desde el centro de Mexico, por todos los países de América Central hasta Venezuela, Colombia, Perú y Ecuador en América del Sur. Debido a la gran variabilidad que presenta en sus características morfológicas y etológicas a lo largo de su distribución geográfica, inicialmente fue dividida en subespecies, aunque posteriormente fue reunificada en uno de los estudios más abarcativos hechos sobre taxonomía de triatominos. Sin embargo, numerosos estudios posteriores, empleando diversas técnicas fenotípicas y genéticas, muestran una variabilidad difícil de atribuir a la de una única especie. Los caracteres fenotípicos (citológicos, morfométricos, isoenzimáticos, etc.) y genéticos (obtenidos mediante los métodos de RAPD, rDNA ITS-1 y 2, 18S RNA, entre otros), analizados con diversas técnicas de análisis multivariado, se han empleado exhaustivamente en la taxonomía de varios grupos de animales, plantas, hongos y bacterias, ayudando a dilucidar y en parte a resolver relaciones que la taxonomía clásica no era capaz de definir. El patrón de hidrocarburos cuticulares de insectos se ha utilizado ampliamente como carácter taxonómico en el estudio de diversas especies; entre las de importancia sanitaria se destacan las de los géneros Glossina sp., Simulium sp. y Anopheles sp. En triatominos se conoce el patrón de hidrocarburos de varias especies y complejos, y se ha determinado su estructura en T. infestans, T. mazzottii y R. prolixus. Dentro del subcomplejo T. sordida, en este trabajo de tesis se pudo discriminar a T. garciabesi como especie distinta de T. sordida, en función de las caracteristicas cuali y cuantitativas de su perfil de hidrocarburos; sin embargo T. patagonica no se diferencia como especie, agrupándose como una población de T. guasayana. T. sordida y T. garciabesi mostraron una relación estrecha entre ambas, siendo T. guasayana la especie más diferenciada del subcomplejo. Las poblaciones de T. sordida quedaron divididas a su vez en dos grupos netamente diferenciados, que podrían ser considerados como subespecies, en coincidencia con otros estudios. El análisis de los hidrocarburos de T. dimidiata reveló que es necesaria una reconsideración de la taxonomía de la especie. Se obtuvieron tres grupos claramente diferenciados, que se corresponden con la clasificación en subespecies hecha originalmente: T. dimidiata maculipennis para la mayoría de los ejemplares mexicanos, T. d. dimidiata para los centroamericanos y T. d. capitata para los de la mayor parte de los sudamericanos. Adicionalmente, se obtuvo un grupo formado por los insectos de la región mexicana de Yucatán y norte de Guatemala que en coincidencia con otros análisis constituiría otra especie o subespecie. Los insectos colectados en los sistemas de cuevas de Lanquín (Guatemala) y en la región cercana de Augustine (Bélice) mostraron un nivel de diferenciación comparable al de otra especie. Los resultados obtenidos en esta tesis muestran que el patrón de hidrocarburos es un marcador taxonómico de gran utilidad y sensibilidad, tanto para discernir las relaciones interespecíficas como para evaluar la variabilidad intraespecífica en triatominos, además permite inferir el movimiento de insectos tanto dentro de una región geográfica como entre ambientes. La información aportada, en conjunto con la obtenida mediante otros marcadores genéticos y fenéticos contribuiría en el diseño de estrategias específicas de los programas de control de la enfermedad.Facultad de Ciencias Naturales y Muse

Cytochrome P450 Genes of the CYP4 Clan and Pyrethroid Resistance in Chagas Disease Vectors

Triatomine insects are vectors of the protozoan Trypanosoma cruzi, the causative agent of Chagas disease. Although residual pyrethroid spraying has been a successful vector control strategy for many years, a growing number of pyrethroid-resistance foci is being documented, mainly in Triatoma infestans, that led to failures in vector elimination. Insecticide resistance is a multifactorial phenomenon that often implies a combination of three different mechanisms: increased insecticide detoxification, reduced affinity of the site of action, and reduced insecticide penetration through the cuticle. All three mechanisms were reported in pyrethroid-resistant T. infestans. Cytochrome P450s are enzymes involved in the metabolism of xenobiotics and endogenous chemicals. They are encoded by CYP genes and classified into different families and clans. In triatomines, the CYP4 clan is divided in two families, CYP3093 and CYP4, and both exhibit genome-wide, triatomine-specific gene expansions. Some members from each family have been reported to be involved in two of the mechanisms mentioned above, i.e., they participate in insecticide detoxification in different organs and tissues, and in the synthesis of cuticular hydrocarbons, which ultimately can contribute to a reduced insecticide penetration. The aim of this manuscript is to review the current state of knowledge of P450 genes belonging to the CYP4 clan in triatomines and to highlight their potential role in insecticide resistance.Fil: Dulbecco, Andrea Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; ArgentinaFil: Pedrini, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; ArgentinaFil: Calderón Fernández, Gustavo Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; Argentin

The cuticular hydrocarbons of the Triatoma sordida species subcomplex (Hemiptera: Reduviidae)

The cuticular hydrocarbons of the Triatoma sordida subcomplex (Hemiptera: Reduviidae: Triatominae) were ana- lysed by gas chromatography and their structures identified by mass spectrometry. They comprised mostly n-alkanes and methyl-branched alkanes with one-four methyl substitutions. n-alkanes consisted of a homologous series from C21-C33 and represented 33-45% of the hydrocarbon fraction; n-C29 was the major component. Methyl-branched alkanes showed alkyl chains from C24-C43. High molecular weight dimethyl and trimethylalkanes (from C35-C39) represented most of the methyl-branched fraction. A few tetramethylalkanes were also detected, comprising mostly even-numbered chains. Several components such as odd-numbered 3-methylalkanes, dimethylalkanes and trimethylalkanes of C37 and C39 showed patterns of variation that allowed the differentiation of the species and populations studied. Triatoma guasayana and Triatoma patagonica showed the most distinct hydrocarbon patterns within the subcomplex. The T. sordida populations from Brazil and Argentina showed significantly different hydrocarbon profiles that posed concerns regarding the homogeneity of the species. Triatoma garciabesi had a more complex hydrocarbon pattern, but it shared some similarity with T. sordida. The quantitative and qualitative variations in the cuticular hydrocarbons may help to elucidate the relationships between species and populations of this insect group.Instituto de Investigaciones Bioquímicas de La Plat

Increased mortality of Acanthoscelides obtectus by alkane-grown Beauveria bassiana

The effect of alkane-growth induction of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (Deuteromycotina: Hyphomycetes), on the ability to kill the bean weevil Acanthoscelides obtectus Say (Coleoptera: Bruchidae), was tested. Adult insects were sprayed with an 0.01% Tween 20 aqueous suspension of 4 × 10⁶ conidia/ml. The performance of fungi grown in complete agar medium containing glucose as carbon source (FS₀) was compared to that of alkane-grown fungi (FS₁) with n-hexadecane as the only carbon source. Mortality increased (p < 0.05) from 22 ± 4.5% to 44 ± 11.4% at day 7, and from 26 ± 5.5% to 60 ± 7.1% 14 days after treatment with FS₀ or FS₁ respectively. The insect epicuticular hydrocarbons were analysed by capillary gas chromatography (CGC); major components were saturated hydrocarbons, 27 to 29 carbons in length. A variety of methyl-branched isomers of C27 were the prevailing structures, and nC27 was the major straight chain component. Whole insect hydrocarbons were qualitatively identical to those of the epicuticular surface. Oleic, linoleic and palmitic acids accounted for almost 88% of the fungal fatty acids, irrespective of the carbon source used for growth; however, the unsaturated/saturated ratio diminished markedly from 4.32 (FS₀) to 2.47 (FS₁). These results indicate that alkane supplementation of culture media might be a tool to improve the virulence of some mycoinsecticides.Instituto de Investigaciones Bioquímicas de La Plat

Inventario de Violencia y Acoso Psicológico en el Trabajo (IVAPT) en Colombia: el peligroso Little Jiffy

(Se trata de una carta el editor, no hay resumen

Smanjenje sindroma sagorijevanja kod zdravstvenih radnika kroz program temeljen na kognitivno-bihevioralnome modelu: Pilot-istraživanje

Peruvian primary healthcare professionals experience high levels of burnout syndrome (BS). This study aims to assess the impact of a cognitive-behavioural model-based (CBMB) program as an occupational intervention to reduce burnout in primary healthcare providers. A total of 29 workers (intervention group = 16) took part in a CBMB intervention training program consisting of one 1-hour weekly session over a period of 6 weeks. Scores of each burnout dimension, as well as other variables, were measured at pre-intervention, post-intervention, and at a 6-month follow-up period using self-report questionnaires. Data collected at these three-time points were analysed using effect size measures and sensitivity statistic. Comparison between pre-intervention and post-intervention scores indicates that emotional exhaustion has the highest improvement among all burnout dimensions (50%), followed by cynicism, but no changes were found with follow-up scores. In the same way, no changes were found in professional efficacy at any stage. The CBMB intervention program showed a short-term reduction of BS in primary healthcare workers, but only in two dimensions of the burnout experience, emotional exhaustion and cynicism.Peruanski djelatnici primarne zdravstvene zaštite pokazuju visoku razinu sindroma sagorijevanja. Cilj je ovoga istraživanja procijeniti učinak programa temeljenoga na kognitivno-bihevioralnome modelu (KBM) kao profesionalne intervencije za smanjenje sagorijevanja kod pružatelja primarne zdravstvene zaštite. Ukupno 29 radnika (intervencijska skupina = 16) sudjelovalo je u intervencijskome programu edukacije temeljenome na KBM-u koji se sastojao od jednoga susreta tjedno u trajanju od 1 sata tijekom 6 tjedana. Rezultati svih dimenzija sagorijevanja, kao i druge varijable, mjereni su upitnicima za samoprocjenu prije intervencije, nakon intervencije i u razdoblju praćenja od 6 mjeseci. Podaci prikupljeni u tim trima vremenskim točkama analizirani su pomoću mjera veličine učinka i statistike osjetljivosti. Usporedba rezultata prije intervencije i rezultata nakon intervencije pokazuje da je od svih dimenzija sagorijevanja kod dimenzije emocionalne iscrpljenosti došlo do najvećega poboljšanja (50 %), a slijedi je cinizam. U rezultatima praćenja nakon 6 mjeseci razlike nisu pronađene. Također, nisu pronađene promjene u profesionalnoj učinkovitosti ni u jednoj fazi mjerenja. Intervencijski program temeljen na KBM-u doveo je do kratkoročnoga smanjenja simptoma sagorijevanja kod djelatnika primarne zdravstvene zaštite, ali samo u dvjema dimenzijama: emocionalnoj iscrpljenosti i cinizmu

Reduction of Burnout Syndrome in Health Workers through a Cognitive-Behavioural Model-Based Program: A Pilot Study

Peruvian primary healthcare professionals experience high levels of burnout syndrome (BS). This study aims to assess the impact of a cognitive-behavioural model-based (CBMB) program as an occupational intervention to reduce burnout in primary healthcare providers. A total of 29 workers (intervention group = 16) took part in a CBMB intervention training program consisting of one 1-hour weekly session over a period of 6 weeks. Scores of each burnout dimension, as well as other variables, were measured at pre-intervention, post-intervention, and at a 6-month follow-up period using self-report questionnaires. Data collected at these three-time points were analysed using effect size measures and sensitivity statistic. Comparison between pre-intervention and post-intervention scores indicates that emotional exhaustion has the highest improvement among all burnout dimensions (50%), followed by cynicism, but no changes were found with follow-up scores. In the same way, no changes were found in professional efficacy at any stage. The CBMB intervention program showed a short-term reduction of BS in primary healthcare workers, but only in two dimensions of the burnout experience, emotional exhaustion and cynicism

Reduction of Burnout Syndrome in Health Workers through a Cognitive-Behavioural Model-Based Program: A Pilot Study

Peruvian primary healthcare professionals experience high levels of burnout syndrome (BS). This study aims to assess the impact of a cognitive-behavioural model-based (CBMB) program as an occupational intervention to reduce burnout in primary healthcare providers. A total of 29 workers (intervention group = 16) took part in a CBMB intervention training program consisting of one 1-hour weekly session over a period of 6 weeks. Scores of each burnout dimension, as well as other variables, were measured at pre-intervention, post-intervention, and at a 6-month follow-up period using self-report questionnaires. Data collected at these three-time points were analysed using effect size measures and sensitivity statistic. Comparison between pre-intervention and post-intervention scores indicates that emotional exhaustion has the highest improvement among all burnout dimensions (50%), followed by cynicism, but no changes were found with follow-up scores. In the same way, no changes were found in professional efficacy at any stage. The CBMB intervention program showed a short-term reduction of BS in primary healthcare workers, but only in two dimensions of the burnout experience, emotional exhaustion and cynicism

Genome of Rhodnius prolixus, an insect vector of Chagas disease, reveals unique adaptations to hematophagy and parasite infection

Rhodnius prolixus not only has served as a model organism for the study of insect physiology, but also is a major vector of Chagas disease, an illness that affects approximately seven million people worldwide. We sequenced the genome of R. prolixus, generated assembled sequences covering 95% of the genome (∼702 Mb), including 15,456 putative protein-coding genes, and completed comprehensive genomic analyses of this obligate blood-feeding insect. Although immunedeficiency (IMD)-mediated immune responses were observed, R. prolixus putatively lacks key components of the IMD pathway, suggesting a reorganization of the canonical immune signaling network. Although both Toll and IMD effectors controlled intestinal microbiota, neither affected Trypanosoma cruzi, the causal agent of Chagas disease, implying the existence of evasion or tolerance mechanisms. R. prolixus has experienced an extensive loss of selenoprotein genes, with its repertoire reduced to only two proteins, one of which is a selenocysteine-based glutathione peroxidase, the first found in insects. The genome contained actively transcribed, horizontally transferred genes from Wolbachia sp., which showed evidence of codon use evolution toward the insect use pattern. Comparative protein analyses revealed many lineage-specific expansions and putative gene absences in R. prolixus, including tandem expansions of genes related to chemoreception, feeding, and digestion that possibly contributed to the evolution of a blood-feeding lifestyle. The genome assembly and these associated analyses provide critical information on the physiology and evolution of this important vector species and should be instrumental for the development of innovative disease control methods.La lista completa de autores que integran el documento puede consultarse en el archivoEste documento tiene una corrección (ver documento relacionado).Centro Regional de Estudios GenómicosInstituto de Investigaciones Bioquímicas de La Plat