The Journal of antimicrobial chemotherapy · 2005
Alterations of the penicillin-binding proteins and murM alleles of clinical Streptococcus pneumoniae isolates with high-level resistance to amoxicillin in Spain.
СтатьяПоддержка исследования: вне правительства СШАНазвание и аннотация: Перевод в очереди
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Cafini Fabio, del Campo Rosa, Alou Luis, Sevillano David, Morosini María Isabel, Baquero Fernando, Prieto José, Spanish Pneumococcal Network (G03/103)
Аннотация
AIMS: The aim of this study was to analyse the nucleotide sequences of regions encoding the penicillin-binding domains of pbp1A, pbp2B and pbp2X genes and murM alleles from 14 selected amoxicillin-resistant Streptococcus pneumoniae isolates (MICs 8-16 mg/L) obtained in Spain.
METHODS: PFGE and dideoxynucleotide chain termination sequencing were used.
RESULTS: Analysis of PFGE profiles showed that the amoxicillin-resistant S. pneumoniae strains belonged to six different PFGE patterns including the Spain23F-1, Spain6B-2, Spain9V-3 and Spain(14)-5 international clones; however, 8 of the 14 strains belonged to the Spain9V-3 clone. These strains showed the typical changes in penicillin-binding proteins (PBPs) 1A and 2X and had 10 unique changes in the 590-641 region of PBP2B as described previously. Transformation experiments tried to incorporate the transpeptidase domain of PBP2B including the 590-641 region associated with amoxicillin-resistant pneumococci. Sequencing of the pbp2B genes revealed that part of the 3' region of the pbp2B sequence encoding a region of the domain (around amino acid 514-538 to the C terminus of PBP2B) did not recombine with the R6 pbp2B gene. The murM sequence analysis showed that 6, 6 and 2 amoxicillin-resistant S. pneumoniae strains had murMA, murMB5 and murMB6 alleles, respectively. However, strains with murMB5 or murMB6 alleles showed a single mutation (N537D) in the 537-581 region of PBP2B, while strains with the murMA allele had 12 unique changes.
CONCLUSIONS: Ten unique changes in the 590-641 region of PBP2B and no specific murM alleles were found in S. pneumoniae strains isolated in Spain with an amoxicillin MIC>or=8 mg/L (MICs from 6 to 12 mg/L by 1 mg/L step dilution). In addition, the presence of specific mutations in PBP2B seems to play a key role in the presence of different murM alleles in these amoxicillin-resistant pneumococcal strains.
METHODS: PFGE and dideoxynucleotide chain termination sequencing were used.
RESULTS: Analysis of PFGE profiles showed that the amoxicillin-resistant S. pneumoniae strains belonged to six different PFGE patterns including the Spain23F-1, Spain6B-2, Spain9V-3 and Spain(14)-5 international clones; however, 8 of the 14 strains belonged to the Spain9V-3 clone. These strains showed the typical changes in penicillin-binding proteins (PBPs) 1A and 2X and had 10 unique changes in the 590-641 region of PBP2B as described previously. Transformation experiments tried to incorporate the transpeptidase domain of PBP2B including the 590-641 region associated with amoxicillin-resistant pneumococci. Sequencing of the pbp2B genes revealed that part of the 3' region of the pbp2B sequence encoding a region of the domain (around amino acid 514-538 to the C terminus of PBP2B) did not recombine with the R6 pbp2B gene. The murM sequence analysis showed that 6, 6 and 2 amoxicillin-resistant S. pneumoniae strains had murMA, murMB5 and murMB6 alleles, respectively. However, strains with murMB5 or murMB6 alleles showed a single mutation (N537D) in the 537-581 region of PBP2B, while strains with the murMA allele had 12 unique changes.
CONCLUSIONS: Ten unique changes in the 590-641 region of PBP2B and no specific murM alleles were found in S. pneumoniae strains isolated in Spain with an amoxicillin MIC>or=8 mg/L (MICs from 6 to 12 mg/L by 1 mg/L step dilution). In addition, the presence of specific mutations in PBP2B seems to play a key role in the presence of different murM alleles in these amoxicillin-resistant pneumococcal strains.
Предметные рубрики MeSH
AllelesAmino Acid SequenceAminoacyltransferasesAmoxicillinBacterial ProteinsDNA, BacterialElectrophoresis, Polyacrylamide GelHumansMicrobial Sensitivity TestsMolecular Sequence DataPenicillin ResistancePenicillin-Binding ProteinsPenicillinsPeptide SynthasesPneumococcal InfectionsReverse Transcriptase Polymerase Chain ReactionSequence Analysis, DNASpainStreptococcus pneumoniaeTransformation, Bacterial