El Uso de Insecticidas para el Control de Haematobia Irritans (L.) (Diptera: Muscidae) en la Argentina

Se efectuaron 806 encuestas en 11 provincias para conocer los insecticidas ylas técnicas de aplicación que se utilizan para el control de la Haematobia irritansen los sistemas productivos de bovinos para leche, carne, cría o ciclo completo enla Argentina. Se observó un uso generalizado de piretroides aplicados en formatópica aunque con ciertas particularidades manifestadas en tres agrupamientos:el primero para Corrientes (ganadería de cría mayoritariamente en la zona infestadacon la garrapata común del vacuno) con propensión a la ausencia de tratamientos;un segundo agrupamiento que caracteriza al resto de la ganadería de cría también en el área infestada con garrapatas, donde es más común el uso depiretroides asociado con avermectinas pero también el uso de avermectinas comoúnico insecticida, con tendencia hacia la aplicación tópica combinada con inyeccióny el empleo de baños de inmersión. El tercer agrupamiento abarca a la regiónlibre de garrapatas con sistemas productivos para leche, invernada y ciclocompleto en la llanura pampeana y Entre Ríos; donde es relativamente común eluso de piretroides asociado con organo-fosforados y el uso de organo-fosforadoscomo único insecticida; la aplicación tópica de biocidas combinado con aspersióno caravanas junto con el uso único de caravanas o aspersión es más notorio eneste agrupamiento.Fil: Suarez, Víctor Humberto. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Castellino, Marta Elena. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Aguirre, Héctor David. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Alcaraz, Eliana Sabrina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Cafrune, Maria Mercedes. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Cetrá, B.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Fader, O. W.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Luciani, C. A.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Mangold, Atilio Jose. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Medus, P. D.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; Argentin

The Forest behind the Tree: Phylogenetic Exploration of a Dominant Mycobacterium tuberculosis Strain Lineage from a High Tuberculosis Burden Country

BACKGROUND: Genotyping of Mycobacterium tuberculosis isolates is a powerful tool for epidemiological control of tuberculosis (TB) and phylogenetic exploration of the pathogen. Standardized PCR-based typing, based on 15 to 24 mycobacterial interspersed repetitive unit-variable number of tandem repeat (MIRU-VNTR) loci combined with spoligotyping, has been shown to have adequate resolution power for tracing TB transmission and to be useful for predicting diverse strain lineages in European settings. Its informative value needs to be tested in high TB-burden countries, where the use of genotyping is often complicated by dominance of geographically specific, genetically homogeneous strain lineages. METHODOLOGY/PRINCIPAL FINDINGS: We tested this genotyping system for molecular epidemiological analysis of 369 M. tuberculosis isolates from 3 regions of Brazil, a high TB-burden country. Deligotyping, targeting 43 large sequence polymorphisms (LSPs), and the MIRU-VNTRplus identification database were used to assess phylogenetic predictions. High congruence between the different typing results consistently revealed the countrywide supremacy of the Latin-American-Mediterranean (LAM) lineage, comprised of three main branches. In addition to an already known RDRio branch, at least one other branch characterized by a phylogenetically informative LAM3 spoligo-signature seems to be globally distributed beyond Brazil. Nevertheless, by distinguishing 321 genotypes in this strain population, combined MIRU-VNTR typing and spoligotyping demonstrated the presence of multiple distinct clones. The use of 15 to 24 loci discriminated 21 to 25% more strains within the LAM lineage, compared to a restricted lineage-specific locus set suggested to be used after SNP analysis. Noteworthy, 23 of the 28 molecular clusters identified were exclusively composed of patient isolates from a same region, consistent with expected patterns of mostly local TB transmission. CONCLUSIONS/SIGNIFICANCE: Standard MIRU-VNTR typing combined with spoligotyping can reveal epidemiologically meaningful clonal diversity behind a dominant M. tuberculosis strain lineage in a high TB-burden country and is useful to explore international phylogenetical ramifications

Mycobacterium tuberculosis complex genetic diversity: mining the fourth international spoligotyping database (SpolDB4) for classification, population genetics and epidemiology

BACKGROUND: The Direct Repeat locus of the Mycobacterium tuberculosis complex (MTC) is a member of the CRISPR (Clustered regularly interspaced short palindromic repeats) sequences family. Spoligotyping is the widely used PCR-based reverse-hybridization blotting technique that assays the genetic diversity of this locus and is useful both for clinical laboratory, molecular epidemiology, evolutionary and population genetics. It is easy, robust, cheap, and produces highly diverse portable numerical results, as the result of the combination of (1) Unique Events Polymorphism (UEP) (2) Insertion-Sequence-mediated genetic recombination. Genetic convergence, although rare, was also previously demonstrated. Three previous international spoligotype databases had partly revealed the global and local geographical structures of MTC bacilli populations, however, there was a need for the release of a new, more representative and extended, international spoligotyping database. RESULTS: The fourth international spoligotyping database, SpolDB4, describes 1939 shared-types (STs) representative of a total of 39,295 strains from 122 countries, which are tentatively classified into 62 clades/lineages using a mixed expert-based and bioinformatical approach. The SpolDB4 update adds 26 new potentially phylogeographically-specific MTC genotype families. It provides a clearer picture of the current MTC genomes diversity as well as on the relationships between the genetic attributes investigated (spoligotypes) and the infra-species classification and evolutionary history of the species. Indeed, an independent Naïve-Bayes mixture-model analysis has validated main of the previous supervised SpolDB3 classification results, confirming the usefulness of both supervised and unsupervised models as an approach to understand MTC population structure. Updated results on the epidemiological status of spoligotypes, as well as genetic prevalence maps on six main lineages are also shown. Our results suggests the existence of fine geographical genetic clines within MTC populations, that could mirror the passed and present Homo sapiens sapiens demographical and mycobacterial co-evolutionary history whose structure could be further reconstructed and modelled, thereby providing a large-scale conceptual framework of the global TB Epidemiologic Network. CONCLUSION: Our results broaden the knowledge of the global phylogeography of the MTC complex. SpolDB4 should be a very useful tool to better define the identity of a given MTC clinical isolate, and to better analyze the links between its current spreading and previous evolutionary history. The building and mining of extended MTC polymorphic genetic databases is in progress

Toxicidad in vitro de la cipermetrina para rhipicephalus (boophilus) microplus (can.) y del diazinón para haematobia irritans (l.) en la Argentina

Se evaluó la susceptibilidad-resistencia de poblaciones argentinas de la garrapata Rhipicephalus microplus (83 poblaciones) y de la mosca Haematobia irritans (125 poblaciones) a la cipermetrina (piretroide) y al diazinón (órgano-fosforado), respectivamente. No se detectaron poblaciones de H. irritans resistentes al diazinón pero se determinaron 19 poblaciones de garrapatas resistentes a la cipermetrina. La mayoría (15) de ellas se concentró en el litoral, especialmente en Corrientes, donde predominan condiciones de mayor aptitud para el desarrollo de R. microplus; la frecuencia anual de tratamiento con acaricidas es alta y los piretroides fueron reemplazados en buena medida por acaricidas a base de formamidina y avermectinas. El resto de las poblaciones resistentes fueron determinadas en el área oeste de la distribución de la garrapata (tres en Córdoba, una en Salta) donde la apatitud para el desarrollo de R. microplus es intermedia y la frecuencia anual de tratamientos es menor que en el este. Se destaca la conveniencia de mantener la evaluación continua del status de la susceptibilidad-resistencia de la H. irritans a los órgano-fosforados para alertar en forma temprana si se comprobara algún cambio en la situación actual. Se considera necesario continuar con la evaluación de la susceptibilidad-resistencia de R. microplus a los piretroides en las áreas donde las poblaciones son aún susceptibles e incorporar técnicas para el diagnóstico de resistencia a formamidinas y avermectinas que son utilizados como acaricidas en una proporción importante de establecimientos ganaderos

Tuberculosis in a southern Brazilian prison

The occurrence of tuberculosis (TB) in prisons has been described as an alarming public health problem in many countries, especially in developing nations. The objective of this study was to conduct a survey among prisoners with TB respiratory symptoms in order to estimate the incidence of the disease, to analyze the drug susceptibility profile and genotype the isolates of Mycobacterium tuberculosis in the city of Charqueadas, southern of Brazil. The TB incidence was 55/1,900 inhabitants in the prison; this corresponds to an incidence of 3,789/100,000 inhabitants, with a prevalence of 72/1,900 (4,960/100,000 inhabitants). Drug susceptibility test was performed and, among the analyzed isolates, 85% were susceptible to all drugs tested and 15% were resistant to at least one drug, of which 89% were resistant only to isoniazid (INH) or in combination with another drug. The genotype classification of spoligotyping analysis showed that 40% of the isolates belong to LAM family, 22% to T family, 17.5% to Haarlem family, 12.5% to U family and 3% to X family. The shared international spoligotypes most frequently found were 729 (27%), 50 (9.5%), 42 (8%), 53 (8%) and 863 (8%). In conclusion, it was observed that TB in this specific population had been caused, mostly, by strains that have been transmitted in the last few years, as demonstrated by the large level of genotype clustering. In addition, it was found specific large clusters, which were not often found in the general population from the same period and in the same region

Mycobacterium tuberculosis strains of Beijing genotype are rarely observed in tuberculosis patients in South America

The frequency of the Beijing genotype of Mycobacterium tuberculosis as a cause of tuberculosis (TB) in South America was determined by analyzing genotypes of strains isolated from patients that had been diagnosed with the disease between 1997 and 2003 in seven countries of the subcontinent. In total, 19 of the 1,202 (1.6%) TB cases carried Beijing isolates, including 11 of the 185 patients from Peru (5.9%), five of the 512 patients from Argentina (1.0%), two of the 252 Brazilian cases (0.8%), one of the 166 patients from Paraguay (0.6%) and none of the samples obtained from Chile (35), Colombia (36) and Ecuador (16). Except for two patients that were East Asian immigrants, all cases with Beijing strains were native South Americans. No association was found between carrying a strain with the Beijing genotype and having drug or multi-drug resistant disease. Our data show that presently transmission of M. tuberculosis strains of the Beijing genotype is not frequent in Latin America. In addition, the lack of association of drug resistant TB and infection with M. tuberculosis of the Beijing genotype observed presently demands efforts to define better the contribution of the virulence and lack of response to treatment to the growing spread of Beijing strains observed in other parts of the world

Genotyping of Mycobacterium tuberculosis isolates from alow-endemic setting in northwestern state of Paraná in Southern Brazil

The purpose of this study was to provide information about the genetic diversity and prevalent genotype of Mycobacterium tuberculosis in a low-endemic setting in northwestern state of Paraná in Southern Brazil. We employed spoligotyping and mycobacterial interspersed repetitive units-variable number tandem repeat (MIRU-VNTR) techniques to genotype M. tuberculosisisolates from patients with pulmonary tuberculosis (TB). The 93 isolates analyzed by spoligotyping were divided into 36 different patterns, 30 of which were described in the SITVIT database. Latin American and Mediterranean, Haarlem and T families were responsible for 26.9%, 17.2% and 11.8% of TB cases, respectively. From the 84 isolates analyzed by MIRU-VNTR, 58 shared a unique pattern and the remaining 26 belonged to nine clusters. The MIRU loci 40, 23, 10 and 16 were the most discriminatory. A combination of MIRU-VNTR and spoligotyping resulted in 85.7% discriminatory power (Hunter-Gaston index = 0.995). Thus, combining spoligotyping and MIRU-VNTR typing proved to be most useful for epidemiological study in this low-endemic setting in Southern Brazil. The current study demonstrated that there is significant diversity in circulating strains in the city of Maringá and the surrounding regions, with no single genotype of M. tuberculosispredominating

Tuberculosis recurrence in a high incidence setting for HIV and tuberculosis in Brazil

Background: To compare epidemiological data between recurrent cases after cure (RC), distinguishing relapse from reinfection, after dropout (RD) and new cases (NC) in an ambulatory setting in a TB-endemic country. Methods: Records of patients who started treatment for pulmonary TB between 2004 and 2010 in a TB clinic were reviewed. Epidemiological data were analyzed. Spoligotyping and MIRU patterns were used to determine relapse or reinfection in 13 RC available. Results: Of the eligible group (1449), 1060 were NC (73.2%), among the recurrent cases, 203 (14%) were RC and 186 (12.8%) were RD. Of RC, 171 (84.2%) occurred later than 6 months after a previous episode, 13 had available DNA, in 4 (30.7%) the disease was attributed to reinfection and in 9 (69.3%), to relapse. Comparing RC to NC, HIV (p < 0.0001) was independent risk factor for RC. When RC and RD were compared, alcohol abuse (p = 0.001) and treatment noncompliance (p = 0.006) were more frequent in RD. Conclusions: HIV is the sole more important associated factor for RC. This finding points the need to improve the approach to manage TB in order to decrease the chance for exposure especially in vulnerable people with increased risk of developing disease and to improve DOTS strategy to deal with factors associated to treatment noncompliance