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Showing 2 results for Multilocus Sequence Typing
Volume 6, Issue 3 (8-2020)
Abstract
Aims: 16S ribosomal RNA methyltransferases (RMTases) confer high-level resistance to aminoglycosides and are increasingly reported among Gram-negative bacilli, especially Klebsiella pneumoniae isolates. The objectives of the present study were to assess the resistance to aminoglycosides, the presence of RMTase genes, and the multilocus sequence typing (MLST) in urinary K. pneumoniae isolates.
Materials & Methods: In this study, 100 K. pneumoniae isolates were tested for susceptibility to amikacin and gentamicin by broth microdilution test according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Then the prevalence of RMTase genes was determined, and alleles and ST type of two selected isolates were identified by MLST. Finally, the isolates were genetically typed using Enterobacterial Repetitive Intergenic Consensus (ERIC) method.
Findings: Broth microdilution assay showed that resistance to amikacin and gentamicin was 70 and 52%, respectively. In addition, 40% of the strains were resistant to both aminoglycosides. Also, rmtC (59.8%) gene was the most common type of RMTase genes investigated, followed by rmtA (51.2%), rmtD (47.6%), rmtF (43.9%), rmtE (41.5%), armA (41.5%), and rmtB (7.3%). K. pneumoniae isolates were assigned into two sequence types: ST51 and ST149. Using ERIC-PCR method, 3-7 different bands and 21 ERIC-PCR profiles were detected among the studied isolates.
Conclusion: The high frequency of aminoglycoside resistance and the increased presence of 16S RMTases in K. pneumoniae strains are of great concern in Iran. Molecular typing showed high genetic diversity among the studied isolates. However, ST51 and ST149 were reported for the first time in Iran and could be considered as emerging strains.
M. Noofeli , M. Asadipour , R. Yari,
Volume 9, Issue 2 (9-2018)
Abstract
Aims: Bordetella pertussis is a gram negative and obligated aerobic bacterium that causes pertussis disease and it is a specific pathogen in human. Pertussis is an acute respiratory infection and leads to death in infants. The aim of this study was to analyze housekeeping genes in Bordetella pertussis vaccine strains by multilocus sequence typing (MLST).
Materials and Methods: In the present experimental study, 4 samples of 134 and 509 bacterial strains and 2 standard samples of Tohama I, and 18323 were collected. After biochemical tests, the samples were cultured and separated and the genomic purification of DNA was done by Phenol–chloroform technique and analyzed by MLST. After genome sequencing, the analysis was performed by standard software such as Clustalw 2, MEGA 5.04, and DNASIS Max 3. Sequence similarity of 16S rDNA gene nucleotides was performed, using BLAST software with sequences recorded in the GenBank genome database to compare and determine the sequences similarity.
Findings: Regarding the created bands and the sequence of the game, the housekeeping genes in Bordetella pertussis vaccine strains were approved. The results of the PCR reaction for Pgm, Icd, Gly A, and Tyr B genes showed that all specimens have homogenous genes with a molecular weight of 500bp.
Conclusion: Evaluating the housekeeping genes in Bordetella pertussis vaccine strains by MLST vaccine strains (Razi Institute; Iran) correspond with international standard series and no change or deviation has occurred in the studied genes.
