ABSTRACT
SETTING: Twenty-nine epidemiological unrelated and mostly multidrug-resistant Mycobacterium tuberculosis (MDR-TB) strains from Peruvian patients. OBJECTIVE: To investigate the molecular genetics of MDR-TB strains recovered in a Latin American country. DESIGN: Antimicrobial agent susceptibility testing, major genetic group designation, IS6110 fingerprinting, spoligotyping, and automated deoxyribonucleic acid sequencing of regions of the katG, rpoB, embB, gyrA, and pncA genes with mutations commonly associated with drug resistance. RESULTS: Nineteen isolates were found to be multidrug-resistant by susceptibility testing. IS6110 typing showed that virtually all isolates were unique and therefore had independently acquired drug resistance. Seventy-nine percent of isoniazid-resistant strains had a Ser315Thr amino acid change in KatG. Ninety-five percent of rifampin-resistant isolates had amino acid replacements in the rifampin-resistance determining region of RpoB. Six of 11 ethambutol-resistant strains had EmbB alterations. Eleven pyrazinamide-resistant strains had distinct mutations in pncA. CONCLUSION: Virtually all organisms evolved drug resistance independently. The types of drug resistance-associated mutations identified were very similar to changes occurring in isolates from other areas of the world. Nucleotide sequence-based strategies for rapid detection of drug resistance-conferring mutants will be applicable to organisms recovered in Peru, and potentially other areas of Latin America.
Subject(s)
Bacterial Proteins , Drug Resistance, Multiple/genetics , Genes, Bacterial , Mycobacterium tuberculosis/genetics , Amidohydrolases/genetics , DNA Gyrase , DNA Topoisomerases, Type II/genetics , DNA-Directed RNA Polymerases , Genotype , Microbial Sensitivity Tests , Mutation , Pentosyltransferases/genetics , Peroxidases/genetics , Peru , Plant Proteins/genetics , Sequence Analysis, DNAABSTRACT
Se estudiaron 954 cepas cuyo aislamiento primario se realizó de muestras clínicas provenientes de todas las regiones del país durante 1989-1990. El objetivo del estudio fue determinar la frecuencia de microbacterias tuberculosas y no tuberculosas en el Laboratorio Nacional de Referencia de Tuberculosis del Perú. Para el aislamiento se utilizó el medio de Lowenstein Jensen. El mayor número de muestras y sus cultivos correspondientes fueron de secreciones pulmonares (97 por ciento); hubo 3 micobacterias no tuberculosas de muestras de orina. La frecuencia de aislamientos de micobacterias tuberculosas en 1989 y 1990 fue de 100 por ciento y 99.3 por ciento respectivamente. Se encontró 4 micobacterias no tuberculosas que correspondieron a M. fortuitum. Los resultados permiten afirmar que M. tuberculosis sigue siendo la micobacteria aislada con mayor frecuencia en las muestras estudiadas.
Subject(s)
Tuberculosis , Mycobacterium fortuitumABSTRACT
Sera from patients infected with Taenia solium, Hymenolepis nana and Echinococcus granulosus were tested against homologous and heterologous parasite antigens using an ELISA assay, and a high degree of cross-reactivity was verified. To identify polypeptides responsible for this cross reactivity, the Enzyme Linked Immunoelectro Transfer Blot (EITB) was used. Sera from infected patients with T.solium, H.nana, and E.granulosus were assessed against crude, ammonium sulphate precipitated (TSASP), and lentil-lectin purified antigens of T.solium and crude antigens of H.nana and E.granulosus. Several bands, recognized by sera from patients with T.solium, H.nana, and E.granulosus infections, were common to either two or all three cestodes. Unique reactive bands in H.nana were noted at 49 and 66 K-Da and in E.granulosus at 17-21 K-Da and at 27-32 K-Da. In the crude cysticercosis extract, a specific non glycoprotein band was present at 61-67 K-Da in addiction to specific glycoprotein bands of 50, 42, 24, 21, 18, 14, and 13 K-Da. None of the sera from patients with H.nana or E.granulosus infection cross reacted with these seven glycoprotein bands considered specific for T.solium infection.