Meta-análise: diagnóstico de tuberculose resistente por técnicas não comerciais de amplificação

La emergencia de tuberculosis (TB) multidrogo y extensivamente-resistente reactivó la necesidad de contar con métodos rápidos para detectar resistencia a isoniacida (INH) y rifampicina (RIF). Por tal motivo, los objetivos de este trabajo fueron evaluar, mediante meta-análisis, la exactitud global y la posible utilidad de métodos caseros basados en PCR para la detección rápida de resistencia a INH y RIF en aislamientos clínicos de Mycobacterium tuberculosis. La búsqueda bibliográfica incluyó Medline/PubMed, BioMedLib. Para estimar la variabilidad entre los resultados de los estudios y el grado de exactitud diagnóstica de los métodos utilizados se realizaron gráficos ?forest plot? y curvas SROC (summary receiver operating characteristic) mediante el software Meta-DiSc. Fueron seleccionados 15 estudios, conteniendo 1311 aislamientos resistentes a INH y 953 a RIF. Para la detección de resistencia a INH la sensibilidad y especificidad globales fueron: 84,0% y 96,0% respectivamente, mientras que para la detección de resistencia a RIF esos valores fueron 92,0% y 97,0%. Además, estos métodos mostraron alta exactitud diagnóstica, con áreas bajo la curva SROC>0,9. La alta sensibilidad y especificidad obtenidas con métodos moleculares caseros sugieren que algunos de ellos podrían ser aplicados para el diagnóstico rápido de resistencia a partir del aislamiento de M. tuberculosis.Due to the emergency of multidrug and extensively-drug resistant tuberculosis, molecular methods for a rapid detection of isoniazid (INH) and rifampicin (RIF) resistance are urgently needed. For that reason, the objectivesof this study were to asses through a meta-analysis the global accuracy and the utility of the home-made molecular methods based in PCR for INH and RIF resistance rapid detection from Mycobacterium tuberculosis clinical isolates. The articles were searched using Medline/PubMed, BioMedLib. The variability among different studies results and the diagnostic accuracy of the used methods were estimated by forest plot and summary receiver operating characteristic (SROC) curves performed with software Meta-DiSc. Fifteen studies were chosed: 1311 containing INH resistant and 953 RIF resistant isolates. The pooled sensitivity and specificity for INH resistance detection was 84.0% and 96.0% respectively, while 92.0% and 97.0% were the pooled values for RIF resistance detection. Besides, these methods showed a high diagnostic accuracy, with the area under the SROC curve >0.9. Due to the high sensitivity and specificity obtained with the home-made molecular methods, some of these tests could be applied for a rapid detection of M. tuberculosis drug resistance in clinical practice.A emergência de tuberculose (TB) multidrogas e extensivamente-resistente reativou a necessidade de contar com métodos rápidos para detectar resistência à isoniazida (INH) e rifampicina (RIF). Por isso, o objetivo deste trabalho foi a avaliação através da meta-análise, da exatidão global e da possível utilidade de métodos caseiros baseados em PCR para detectar rapidamente a resistência a INH e RIF em isolamentos clínicos de Mycobacterium tuberculosis. A pesquisa bibliográfica incluiu Medline/PubMed, Bio MedLib. Para estimar a variabilidade entre os resultados dos estudos e o grau de exatidão diagnóstica dos métodos utilizados, foram realizados gráficos "forest plot" e curvas SROC (summary receiver operating characteristic) com o software Meta-Disc. Foram selecionados 15 estudos, contendo 1311 isolamentos resistentes a INH e 953 a RIF. Para a detecção de resistência a INH, a sensibilidade e especificidade globais foram 84,0% e 96,0% respectivamente, enquanto que para a detecção de resistência a RIF esses valores foram de 92,0% e 97,0%. Alem disso, os mesmos métodos mostraram elevada exatidão diagnóstica, com áreas inferiores à curva SROC>0,9. A elevada sensibilidade e especificidade obtida através de métodos moleculares caseiros sugere que alguns deles poderiam ser aplicados para o diagnóstico rápido de resistência a partir do isolamento de M. tuberculosis.Fil: Imperiale, Belén Rocío. Provincia de Buenos Aires. Ministerio de Salud. Hospital "dr.antonio A. Cetrangolo". Laboratorio de Referencia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Evaluation of MGIT 960 and the colorimetric-based method for tuberculosis drug susceptibility testing

SETTING: Dr Cetrángolo Hospital, Buenos Aires Province, Argentina. OBJECTIVE: Evaluation of the BACTEC? Mycobacteria Growth Indicator Tube (MGIT)? 960 system and the colorimetric-based method (CMM) for fi rst- and second line drug susceptibility testing (FL-DST, SL-DST) against Mycobacterium tuberculosis. DESIGN: FL-DST was studied using SIRE MGIT 960. Minimal inhibitory concentrations (MICs) for isoniazid (INH), streptomycin, rifampicin (RMP), ethambutol (EMB) and levofl oxacin (LVX) were also determined by CMM using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT). MICs for amikacin (AMK), kanamycin (KM), capreomycin (CPM), ethionamide (ETH), cycloserine, ofl oxacin (OFX), linezolide (LZ) and moxifl oxacin (MFX) were determined on 94 multidrug resistant M. tuberculosis isolates by MGIT 960 and CMM. Statistical methods were applied to define drug susceptible and drug-resistant isolates on the basis of the comparison between results obtained by gold standards. RESULTS: A total of 1626 clinical isolates were studied. Critical drug concentrations could be defi ned in less than 10 days for both CMM and MGIT 960. CMM was cheaper but more laborious than MGIT 960. The highest performances of both methods were achieved for AMK, RMP, OFX, LZ and MFX, followed by INH, ETH, KM, CPM and LVX (tested only by CMM). CONCLUSIONS: Both methods could be implemented as rapid diagnostic tools to detect drug-resistant isolates in clinical practice.Fil: Morcillo, N.. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; ArgentinaFil: Imperiale, Belén Rocío. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Di Giulio, B.. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; Argentin

Evaluation of MGIT 960 and the colorimetric-based method for tuberculosis drug susceptibility testing

SETTING: Dr Cetrángolo Hospital, Buenos Aires Province, Argentina. OBJECTIVE: Evaluation of the BACTEC? Mycobacteria Growth Indicator Tube (MGIT)? 960 system and the colorimetric-based method (CMM) for fi rst- and second line drug susceptibility testing (FL-DST, SL-DST) against Mycobacterium tuberculosis. DESIGN: FL-DST was studied using SIRE MGIT 960. Minimal inhibitory concentrations (MICs) for isoniazid (INH), streptomycin, rifampicin (RMP), ethambutol (EMB) and levofl oxacin (LVX) were also determined by CMM using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT). MICs for amikacin (AMK), kanamycin (KM), capreomycin (CPM), ethionamide (ETH), cycloserine, ofl oxacin (OFX), linezolide (LZ) and moxifl oxacin (MFX) were determined on 94 multidrug resistant M. tuberculosis isolates by MGIT 960 and CMM. Statistical methods were applied to define drug susceptible and drug-resistant isolates on the basis of the comparison between results obtained by gold standards. RESULTS: A total of 1626 clinical isolates were studied. Critical drug concentrations could be defi ned in less than 10 days for both CMM and MGIT 960. CMM was cheaper but more laborious than MGIT 960. The highest performances of both methods were achieved for AMK, RMP, OFX, LZ and MFX, followed by INH, ETH, KM, CPM and LVX (tested only by CMM). CONCLUSIONS: Both methods could be implemented as rapid diagnostic tools to detect drug-resistant isolates in clinical practice.Fil: Morcillo, N.. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; ArgentinaFil: Imperiale, Belén Rocío. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Di Giulio, B.. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; Argentin

Rapid detection of multidrug-resistant Mycobacterium tuberculosis by multiplex allele-specific polymerase chain reaction

OBJECTIVE: To evaluate a multiplex allele-specifi c polymerase chain reaction (MAS-PCR) to detect multidrugresistant tuberculosis (MDR-TB) clinical isolates and to describe the main mutations conferring resistance to isoniazid (INH) and rifampicin (RMP). DESIGN: Drug-resistant Mycobacterium tuberculosis clinical isolates were tested to detect mutations using MAS-PCR. The genes involved were katG, inhA promoter and rpoB. RESULTS: Among 193 clinical isolates included in the study, 52.6% of the INH-resistant isolates presented a mutation in the katG (315) gene, 28.1% in the inhAP (−15) and 3.0% in both. For the rpoB gene, 60% of the RMP-resistant isolates showed a mutation in codon 531, 17.5% in 526 and 2.5% in 516. Results were compared with those obtained by sequencing, and 100% concordance was obtained for the detection of the mutation in katG (315), 94.1% for inhAP (−15), and 97.8% for rpoB. The global concordance between both methods was 98%. CONCLUSIONS: The MAS-PCR system allowed the simultaneous and rapid detection of approximately 80.0% of the drug-resistant clinical isolates. This method could be used as a rapid and simple screening tool to detect drug-resistant TB in clinical practice.Fil: Imperiale, Belén Rocío. Provincia de Buenos Aires. Ministerio de Salud. Hospital ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cataldi, Ángel Adrián. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Morcillo, N. S.. Provincia de Buenos Aires. Ministerio de Salud. Hospital ; Argentin

Surveillance and Characterization of Drug‑Resistant Mycobacterium tuberculosis Isolated in a Reference Hospital from Argentina during 8 Years’ Period

Background: Argentina is considered a country with a middle tuberculosis (TB) incidence. However, according to the last national epidemiological report released in 2018, since 2013, the trends are steadily increasing. The aims of this study were to determine the drug‑resistance (DR), multi‑DR and extensively DR (MDR/XDR‑TB), and rifampicin resistance (RIF‑R) burden as a part of the local TB diagnosis (June 2010–August 2018); to detect the mutations associated to isoniazid (INH) and RIF‑R and their geographical distribution; and to analyze the lineage relationship among the genetic patterns of the isolates circulating in the community. Methods: Respiratory and extrapulmonary specimens were processed by Ziehl–Neelsen stain and cultured on specific media. Drug‑susceptibility testing of isolates was performed by the MGIT 960 and a colorimetric micro‑method. Mutations conferring DR were detected by Genotype and DNA sequencing. Results: The study showed a DR‑TB prevalence of approximately 20% of the isolated strains, while M/XDR‑TB‑and particularly RIF‑R‑affected more than 5.0% of the total amount of cases. DR geographical distribution revealed isolates carrying mutations in the inhA gene promoter region only constrained to three districts where it was also registered two same family relatives’ cases with the infrequent rpoB S522 L/Q mutation. The fact that most DR/MDR‑TB isolates were not grouped in genetic clusters suggested that these cases may mostly have occurred due to endogenous reactivation rather than recently transmission. Conclusion: According to the obtained results, it would be convenient, in highly MDR‑TB suspected individuals, to confirm phenotypically, the INH and RIF susceptibility detected by molecular tests.Fil: Imperiale, Belén Rocío. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Di Giulio, Ángela Beatríz. Provincia de Buenos Aires. Hospital "Petrona V. de Cordero"; ArgentinaFil: Mancino, María Belén. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; ArgentinaFil: Zumárraga, Martín José. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Agrobiotecnologia y Biologia Molecular. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Agrobiotecnologia y Biologia Molecular; ArgentinaFil: Morcillo, Nora Susana. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; Argentin

Detection of first- and second-line drug resistance in Mycobacterium tuberculosis clinical isolates by pyrosequencing

Conventional phenotypic drug susceptibility testing (DST) methods for Mycobacterium tuberculosis are laborious and very time-consuming. Early detection of drug-resistant tuberculosis (TB) is essential for prevention and control of TB transmission. We have developed a pyrosequencing method for simultaneous detection of mutations associated with resistance to rifampin, isoniazid, ethambutol, amikacin, kanamycin, capreomycin, and ofloxacin. Seven pyrosequencing assays were optimized for following loci: rpoB, katG, embB, rrs, gyrA, and the promoter regions of inhA and eis. The molecular method was evaluated on a panel of 290 clinical isolates of M. tuberculosis. In comparison to phenotypic DST, the pyrosequencing method demonstrated high specificity (100%) and sensitivity (94.6%) for detection of multidrug-resistant M. tuberculosis as well as high specificity (99.3%) and sensitivity (86.9%) for detection of extensively drug-resistant M. tuberculosis. The short turnaround time combined with multilocus sequencing of several isolates in parallel makes pyrosequencing an attractive method for drug resistance screening in M. tuberculosis.Fil: Engström, Anna. Karolinska Huddinge Hospital. Karolinska Institutet; Suecia. Swedish Institute for Communicable Disease Control; SueciaFil: Morcillo, Nora Susana. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; ArgentinaFil: Imperiale, Belén Rocío. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; ArgentinaFil: Hoffner, Sven E.. Karolinska Huddinge Hospital. Karolinska Institutet; Suecia. Swedish Institute for Communicable Disease Control; SueciaFil: Juréen, Pontus. Karolinska Huddinge Hospital. Karolinska Institutet; Suecia. Swedish Institute for Communicable Disease Control; Sueci

Primera evaluación en Argentina de GenoType® MTBDRplus para la detección de Mycobacterium tuberculosis multidrogo-resistente desde aislamientos y especímenes clínicos

Tuberculosis (tB) and multidrug and extensively drug-resistant (dR) tB are important public health problems that are spreading worldwide. The aims of this study were to determine the sensitivity and specificity of the genotype® mtBdRplus assay from smear-positive clinical specimens and isolates and to explore its possible application in routine work. Clinical samples were previously decontaminated using naoH-n-acetyl-l-cystein or naoH-Clna hypertonic solution for Ziehl-neelsen staining and cultures. The leftover sediments of smear-positive samples were stored at -20 °C, 70 of which were selected to be included in this study according to their dR profile. thirty dR Mycobacterium tuberculosis isolates were also assessed. Sequencing was used as gold standard to detect mutations conferring isoniazid (InH) and rifampicin (RIF) resistance. Valid results were obtained in 94.0 % of the samples and 85.5 % (53/62) of the InH-R samples were properly identified. mutations in the katGS315t gene and inhA C-15t gene promoter region were present in 59.7 % (37/62) and 25.8 % (16/62) of the InH-R samples, respectively. the system could also identify 97.7 % (41/42) of the RIF-R samples; the mutations found were rpoBS531l (66.7 %, 28/42), d516V (19.0 %, 8/42), H526Y and S531p/W (4.8 %, 2/42 each one), and S522l/Q (2.4 %, 1/42). a 98.8 % concordance between the genotype assay and sequencing was obtained. genotype® mtBdRplus has demonstrated to be easy to implement and to perform in clinical laboratories and useful for a rapid detection of dR M. tuberculosis from decontaminated sputa and clinical isolates. Therefore, this assay could be applied as a rapid tool to predict InH-R and/or RIF-R in dR risk cases.La tuberculosis (TBC), y la TBC multi y extensivamente drogo-resistentes (DR) son importantes problemas de salud pública mundial. El objetivo de este estudio fue determinar la sensibilidad y especificidad del sistema GenoType® MTBDRplus a partir de esputos (baciloscopía positiva) y aislamientos clínicos de Mycobacterium tuberculosis, explorando su aplicación clínica. Previo a la tinción de Ziehl-Neelsen y al cultivo, las muestras fueron descontaminadas mediante NaOH-N-acetyl-L-cisteina o la solución hipertónica NaOH-NaCl. Los sedimentos remanentes se conservaron a –20 ºC, y 70 de ellos fueron incluidos en este estudio según su perfil de DR. Treinta cepas de M. tuberculosis DR fueron también evaluadas. La secuenciación fue utilizada como método de referencia para la detección de mutaciones que confieren resistencia a isoniacida (INH) y rifampicina (RIF). Se obtuvieron resultados válidos en el 94,0 % de las muestras, identificándose al 85,5 % (53/62) de las INH-R. La mutación katG S315T estuvo presente en 59,7 % (37/62), y la mutación C-15T del promotor del gen inhA en 25,8 % (16/62) de las mismas. El sistema identificó el 97,7 % (41/42) de las muestras RIF-R. Las mutaciones encontradas fueron rpoB S531L (66,7 %, 28/42), D516V (19,0 %, 8/42), H526Y y S531P/W (4,8 %, 2/42 cada una de ellas) y S522L/Q (2,4 %, 1/42). La concordancia entre el GenoType y la secuenciación fue del 98,8 %. El sistema GenoType® MTBDRplus resultó ser útil, fácil de realizar e implementar para la detección rápida de M. tuberculosis DR. Por lo tanto, este ensayo podría ser aplicado como una herramienta rápida para el diagnostico de TBC DR, principalmente en aquellos casos asociados a factores de riesgo.Fil: Imperiale, Belén Rocío. Provincia de Buenos Aires. Ministerio de Salud. Hospital ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zumárraga, Martín José. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Weltman, Gabriela. Provincia de Buenos Aires. Ministerio de Salud. Hospital ; ArgentinaFil: Zudiker, Roxana. Provincia de Buenos Aires. Ministerio de Salud. Hospital ; ArgentinaFil: Cataldi, Ángel Adrián. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Morcillo, Nora Susana. Provincia de Buenos Aires. Ministerio de Salud. Hospital ; Argentin

Primera evaluación en Argentina de GenoType® MTBDRplus para la detección de Mycobacterium tuberculosis multidrogo-resistente desde aislamientos y especímenes clínicos

Tuberculosis (tB) and multidrug and extensively drug-resistant (dR) tB are important public health problems that are spreading worldwide. The aims of this study were to determine the sensitivity and specificity of the genotype® mtBdRplus assay from smear-positive clinical specimens and isolates and to explore its possible application in routine work. Clinical samples were previously decontaminated using naoH-n-acetyl-l-cystein or naoH-Clna hypertonic solution for Ziehl-neelsen staining and cultures. The leftover sediments of smear-positive samples were stored at -20 °C, 70 of which were selected to be included in this study according to their dR profile. thirty dR Mycobacterium tuberculosis isolates were also assessed. Sequencing was used as gold standard to detect mutations conferring isoniazid (InH) and rifampicin (RIF) resistance. Valid results were obtained in 94.0 % of the samples and 85.5 % (53/62) of the InH-R samples were properly identified. mutations in the katGS315t gene and inhA C-15t gene promoter region were present in 59.7 % (37/62) and 25.8 % (16/62) of the InH-R samples, respectively. the system could also identify 97.7 % (41/42) of the RIF-R samples; the mutations found were rpoBS531l (66.7 %, 28/42), d516V (19.0 %, 8/42), H526Y and S531p/W (4.8 %, 2/42 each one), and S522l/Q (2.4 %, 1/42). a 98.8 % concordance between the genotype assay and sequencing was obtained. genotype® mtBdRplus has demonstrated to be easy to implement and to perform in clinical laboratories and useful for a rapid detection of dR M. tuberculosis from decontaminated sputa and clinical isolates. Therefore, this assay could be applied as a rapid tool to predict InH-R and/or RIF-R in dR risk cases.La tuberculosis (TBC), y la TBC multi y extensivamente drogo-resistentes (DR) son importantes problemas de salud pública mundial. El objetivo de este estudio fue determinar la sensibilidad y especificidad del sistema GenoType® MTBDRplus a partir de esputos (baciloscopía positiva) y aislamientos clínicos de Mycobacterium tuberculosis, explorando su aplicación clínica. Previo a la tinción de Ziehl-Neelsen y al cultivo, las muestras fueron descontaminadas mediante NaOH-N-acetyl-L-cisteina o la solución hipertónica NaOH-NaCl. Los sedimentos remanentes se conservaron a –20 ºC, y 70 de ellos fueron incluidos en este estudio según su perfil de DR. Treinta cepas de M. tuberculosis DR fueron también evaluadas. La secuenciación fue utilizada como método de referencia para la detección de mutaciones que confieren resistencia a isoniacida (INH) y rifampicina (RIF). Se obtuvieron resultados válidos en el 94,0 % de las muestras, identificándose al 85,5 % (53/62) de las INH-R. La mutación katG S315T estuvo presente en 59,7 % (37/62), y la mutación C-15T del promotor del gen inhA en 25,8 % (16/62) de las mismas. El sistema identificó el 97,7 % (41/42) de las muestras RIF-R. Las mutaciones encontradas fueron rpoB S531L (66,7 %, 28/42), D516V (19,0 %, 8/42), H526Y y S531P/W (4,8 %, 2/42 cada una de ellas) y S522L/Q (2,4 %, 1/42). La concordancia entre el GenoType y la secuenciación fue del 98,8 %. El sistema GenoType® MTBDRplus resultó ser útil, fácil de realizar e implementar para la detección rápida de M. tuberculosis DR. Por lo tanto, este ensayo podría ser aplicado como una herramienta rápida para el diagnostico de TBC DR, principalmente en aquellos casos asociados a factores de riesgo.Fil: Imperiale, Belén Rocío. Provincia de Buenos Aires. Ministerio de Salud. Hospital ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zumárraga, Martín José. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Weltman, Gabriela. Provincia de Buenos Aires. Ministerio de Salud. Hospital ; ArgentinaFil: Zudiker, Roxana. Provincia de Buenos Aires. Ministerio de Salud. Hospital ; ArgentinaFil: Cataldi, Ángel Adrián. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Morcillo, Nora Susana. Provincia de Buenos Aires. Ministerio de Salud. Hospital ; Argentin

Genetic diversity of <i>Mycobacterium avium</i> complex strains isolated in Argentina by MIRU-VNTR

Mycobacterium avium sp. avium (MAA), M. avium sp. hominissuis (MAH), and M. avium sp. paratuberculosis (MAP) are the main members of the M. avium complex (MAC) causing diseases in several hosts. The aim of this study was to describe the genetic diversity of MAC isolated from different hosts. Twenty-six MAH and 61 MAP isolates were recovered from humans and cattle, respectively. GenoType CM® and IS1311-PCR were used to identify Mycobacterium species. The IS901-PCR was used to differentiate between MAH and MAA, while IS900-PCR was used to identify MAP. Genotyping was performed using a mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) scheme (loci: 292, X3, 25, 47, 3, 7, 10, 32) and patterns (INMV) were assigned according to the MAC-INMV database (http://mac-inmv.tours.inra.fr/). Twenty-two (22/26, 84·6%) MAH isolates were genotyped and 16 were grouped into the following, INMV 92, INMV 121, INMV 97, INMV 103, INMV 50, and INMV 40. The loci X3 and 25 showed the largest diversity (D: 0·5844), and the global discriminatory index (Hunter and Gaston discriminatory index, HGDI) was 0·9300. MAP (100%) isolates were grouped into INMV 1, INMV 2, INMV 11, INMV 8, and INMV 5. The HGDI was 0·6984 and loci 292 and 7 had the largest D (0·6980 and 0·5050). MAH presented a higher D when compared with MAP. The MIRU-VNTR was a useful tool to describe the genetic diversity of both MAH and MAP as well as to identify six new MAH patterns that were conveniently reported to the MAC-INMV database. It was also demonstrated that, in the geographical region studied, human MAC cases were produced by MAH as there was no MAA found among the human clinical samples.Facultad de Ciencias VeterinariasCentro de Diagnóstico e Investigaciones Veterinaria

Genetic diversity of <i>Mycobacterium avium</i> complex strains isolated in Argentina by MIRU-VNTR

Mycobacterium avium sp. avium (MAA), M. avium sp. hominissuis (MAH), and M. avium sp. paratuberculosis (MAP) are the main members of the M. avium complex (MAC) causing diseases in several hosts. The aim of this study was to describe the genetic diversity of MAC isolated from different hosts. Twenty-six MAH and 61 MAP isolates were recovered from humans and cattle, respectively. GenoType CM® and IS1311-PCR were used to identify Mycobacterium species. The IS901-PCR was used to differentiate between MAH and MAA, while IS900-PCR was used to identify MAP. Genotyping was performed using a mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) scheme (loci: 292, X3, 25, 47, 3, 7, 10, 32) and patterns (INMV) were assigned according to the MAC-INMV database (http://mac-inmv.tours.inra.fr/). Twenty-two (22/26, 84·6%) MAH isolates were genotyped and 16 were grouped into the following, INMV 92, INMV 121, INMV 97, INMV 103, INMV 50, and INMV 40. The loci X3 and 25 showed the largest diversity (D: 0·5844), and the global discriminatory index (Hunter and Gaston discriminatory index, HGDI) was 0·9300. MAP (100%) isolates were grouped into INMV 1, INMV 2, INMV 11, INMV 8, and INMV 5. The HGDI was 0·6984 and loci 292 and 7 had the largest D (0·6980 and 0·5050). MAH presented a higher D when compared with MAP. The MIRU-VNTR was a useful tool to describe the genetic diversity of both MAH and MAP as well as to identify six new MAH patterns that were conveniently reported to the MAC-INMV database. It was also demonstrated that, in the geographical region studied, human MAC cases were produced by MAH as there was no MAA found among the human clinical samples.Facultad de Ciencias VeterinariasCentro de Diagnóstico e Investigaciones Veterinaria