Estudio de la susceptibilidad a los antibióticos de aislados clínicos de Mycobacterium abscessus. Reporte preliminar

Resumen: Mycobacterium abscessus posee una elevada resistencia a los antibióticos, lo cual limita las opciones terapéuticas para tratar las infecciones causadas por este microorganismo. En este estudio se determinó la susceptibilidad antimicrobiana de 26 cepas de M. abscessus de origen clínico frente a 14 antibióticos, mediante el método de microdilución en caldo (MDC) de acuerdo al procedimiento descrito por el CLSI (2011). Todas las cepas fueron sensibles a la amikacina, seguidas de claritromicina (62%) e imipenem (46%), mientras que el porcentaje de sensibilidad a ciprofloxacina, ampicilina/sulbactam, meropenem, ceftriaxona, amoxacilina y doxiciclina osciló entre 0 y 8%. Nueve diferentes patrones de resistencia fueron observados, representados por la asociación de 4 a 12 antibióticos. La combinación de 8 y 10 marcadores de resistencia constituyeron los patrones más frecuentes (28% cada uno). La amikacina fue el antibiótico con mayor actividad inhibitoria frente a las cepas estudiadas (0,5 – 16 µg/mL). Los patrones de resistencia observados sugieren la necesidad de utilizar las pruebas de susceptibilidad como herramientas que permitan orientar y optimizar las conductas terapéuticas en infecciones producidas por M. abscessus.Study of antibiotic susceptibility of Mycobacterium abscessus clinical isolates. Preliminary report Abstract: Mycobacterium abscessus has a high antibiotic resistance, which limits therapeutic options for treating infections produced by this microorganism. In this study we determined the antimicrobial susceptibility of 26 M. abscessus strain of clinical origin towards 14 antibiotics through the broth microdilution method (BMD) according to the procedure described by the CLSI (2011). All the strains were sensitive to amikacine, followed by clarithromycin (62%), and imipenem (46%), while the percentage sensitivity to ciprofloxacin, ampicillin/sulbactam, meropenem, ceftriaxone, amoxicycillin, and doxicycline varied between 0 and 8%. Nine different resistant patterns were observed, represented by the association of 4 to 12 antibiotics. The combination of 8 and 10 resistance markers constituted the most frequent patterns (28% each). Amikacin was the antibiotic with the highest inhibitory activity towards all the strains studied (0.5 – 16 µg/mL). The resistance patterns observed indicate the need of using susceptibility tests as tools that allow to guide and optimize the therapeutic approach to M. abscessus produced infections

Exploring the "Latin American Mediterranean" family and the RDRio lineage in Mycobacterium tuberculosis isolates from Paraguay, Argentina and Venezuela

Submitted by Sandra Infurna ([email protected]) on 2020-03-28T17:15:58Z No. of bitstreams: 1 HarrrisonGomes_SidraVasconcelos_etal_IOC_2019.pd.pdf: 1746618 bytes, checksum: 5564ed65983e850073abda10c0053dea (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2020-03-28T17:43:14Z (GMT) No. of bitstreams: 1 HarrrisonGomes_SidraVasconcelos_etal_IOC_2019.pd.pdf: 1746618 bytes, checksum: 5564ed65983e850073abda10c0053dea (MD5)Made available in DSpace on 2020-03-28T17:43:14Z (GMT). No. of bitstreams: 1 HarrrisonGomes_SidraVasconcelos_etal_IOC_2019.pd.pdf: 1746618 bytes, checksum: 5564ed65983e850073abda10c0053dea (MD5) Previous issue date: 2019Universidad Nacional de Asunción. Instituto de Investigaciones en Ciencias de la Salud. Departamento de Biología Molecular y Biotecnología. Asunción, Paraguay / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular aplicada às Micobactérias. Rio de Janeiro, RJ, Brasil.Universidad Nacional de Asunción. Instituto de Investigaciones en Ciencias de la Salud. Departamento de Biología Molecular y Biotecnología. Asunción, Paraguay.Universidad Nacional de Asunción. Instituto de Investigaciones en Ciencias de la Salud. Departamento de Biología Molecular y Biotecnología. Asunción, Paraguay.Instituto Nacional de Enfermedades Infecciosas, ANLIS “Carlos G. Malbran”. Servicio de Micobacterias. Buenos Aires. Argentina.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular aplicada às Micobactérias. Rio de Janeiro, RJ, Brasil..Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Microbiologia Celular, Rio de Janeiro, RJ, Brasil.Laboratorio Central de Salud Pública, MSP y BS. Asunción, Paraguay.Instituto Nacional de Enfermedades Respiratorias Emilio Coni. Buenos Aires, Argentina.Instituto de Biomedicina. Laboratorio de Tuberculosis. Caracas, Venezuela / Universidad de Las Américas Facultad de Ciencias de la Salud. One Health Research Group. Quito, Ecuador.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular aplicada às Micobactérias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular aplicada às Micobactérias. Rio de Janeiro, RJ, Brasil.The Latin American & Mediterranean (LAM) spoligotype family is one of the most successful genotype of Mycobacterium tuberculosis worldwide and particularly prevalent in South-America. Within this family, a sublineage named Region of Difference Rio (RDRio) was reported initially in Brazil and is characterized by a genomic deletion of about 26.3 kb. This lineage seems to show a specific adaptation to the Euro-Latin American population. In this context, we sought to evaluate the LAM family and the presence of the RDRio genotype in samples from three Latin American countries including Paraguay, Venezuela and Argentina. To detect LAM strains reliably we applied a typing scheme using spoligotyping, 12 loci MIRU-VNTR, the Ag85C103 SNP and the regions of difference RDRio and RD174. IS6110-RFLP results were also used when available

Evaluation of the transcriptional immune biomarkers in peripheral blood from Warao indigenous associate with the infection by Mycobacterium tuberculosis

Abstract INTRODUCTION: Biomarkers are critical tools for finding new approaches for controlling the spread of tuberculosis (TB), including for predicting the development of TB therapeutics, vaccines, and diagnostic tools. METHODS: Expression of immune biomarkers was analyzed in peripheral blood cells stimulated and non-stimulated with M. tuberculosis antigens ESAT-6, CFP10 and TB7.7. in Warao indigenous individuals. These biomarkers may be able to differentiate TB states, such as active tuberculosis (ATB) cases and latent tuberculosis infection (LTBI) from non-infected controls (NIC). A real-time reverse transcription polymerase chain reaction (RT-qPCR) assay was performed on 100 blood samples under non-stimulation or direct ex vivo conditions (NS=50) and stimulation conditions (S=50). RESULTS: The findings are shown as the median and interquartile range (IQR) of relative gene expression levels of IFN-γ, CD14, MMP9, CCR5, CCL11, CXCL9/MIG, and uPAR/PLAUR immune biomarkers. MMP9 levels were significantly higher in the LTBI-NS and LTBI-S groups compared with the NIC-NS and NIC-S groups. However, CCR5 levels were significantly lower in the LTBI-S group compared with both NIC-NS and NIC-S groups. CCL11 levels were significantly lower in the LTBI-S group compared with the NIC-NS group. CONCLUSIONS: Preliminary findings showed that MMP9 immune biomarkers separated LTBI indigenous individuals from NIC indigenous individuals, while CCR5, CCL11, CD14, and IFN-γ did not differentiate TB states from NIC. MMP9 may be useful as a potential biomarker for LTBI and new infected case detection among Warao indigenous individuals at high risk of developing the disease. It may also be used to halt the epidemic, which will require further validation in larger studies