Molecular characterization of penicillin non-susceptible Streptococcus pneumoniae in Christchurch, New Zealand (original) (raw)
Related papers
1998
A total of 26% of the pneumococci isolated from an outpatient clinic in Nairobi, Kenya, during 1991Kenya, during to 1992 had intermediate levels of penicillin resistance. Gene fingerprinting and DNA sequencing were used to distinguish the penicillin-binding protein (PBP) LA, 2B, and 2X genes in 23 resistant isolates. Isolates were grouped into those that had identical forms of each of the three PBP genes (fingerprint groups) and those that had identical rRNA gene restriction patterns (ribotypes). Both methods divided the isolates into 11 groups. In a few cases, horizontal gene transfer appeared to have distributed an identical altered PBP gene into different pneumococcal lineages. Eight isolates were indistinguishable by ribotyping or multilocus enzyme electrophoresis and contained identical PBP LA genes. Although these isolates were therefore members of the same clone, they were divided into two fingerprint groups which contained different PBP 2X and 2B genes. Presumably, members of this clone have acquired different altered PBP 2X and 2B genes on two separate occasions. One of these fingerprint groups contained isolates of serotype 14, whereas the other contained isolates of both serotypes 14 and 7. The identification of isolates in the latter group that are identical by all criteria, except serotype, implies the occurrence of a change in serotype. The predominant serotypes of the penicillin-resistant pneumococci from Nairobi were serotypes 14 and 19. In both cases, isolates of the same serotype which required the same MIC of penicillin were not members of a single clone, indicating that identity of serotype and MIC are not sufficient criteria for defining clones of resistant pneumococci even when the bacteria are isolated from a single clinic.
Molecular epidemiology of penicillin-resistant Streptococcus pneumoniae isolated in central Taiwan
Diagnostic Microbiology and Infectious Disease, 1998
A total of 26% of the pneumococci isolated from an outpatient clinic in Nairobi, Kenya, during 1991Kenya, during to 1992 had intermediate levels of penicillin resistance. Gene fingerprinting and DNA sequencing were used to distinguish the penicillin-binding protein (PBP) LA, 2B, and 2X genes in 23 resistant isolates. Isolates were grouped into those that had identical forms of each of the three PBP genes (fingerprint groups) and those that had identical rRNA gene restriction patterns (ribotypes). Both methods divided the isolates into 11 groups. In a few cases, horizontal gene transfer appeared to have distributed an identical altered PBP gene into different pneumococcal lineages. Eight isolates were indistinguishable by ribotyping or multilocus enzyme electrophoresis and contained identical PBP LA genes. Although these isolates were therefore members of the same clone, they were divided into two fingerprint groups which contained different PBP 2X and 2B genes. Presumably, members of this clone have acquired different altered PBP 2X and 2B genes on two separate occasions. One of these fingerprint groups contained isolates of serotype 14, whereas the other contained isolates of both serotypes 14 and 7. The identification of isolates in the latter group that are identical by all criteria, except serotype, implies the occurrence of a change in serotype. The predominant serotypes of the penicillin-resistant pneumococci from Nairobi were serotypes 14 and 19. In both cases, isolates of the same serotype which required the same MIC of penicillin were not members of a single clone, indicating that identity of serotype and MIC are not sufficient criteria for defining clones of resistant pneumococci even when the bacteria are isolated from a single clinic.
Differentiation of Penicillin Susceptible and Nonsusceptible Streptococcus pneumoniae
Introduction: Streptococcus pneumoniae (S. pneumoniae) cause morbidity and mortality in infants and younger children. Because of high prevalence of penicillin resistance, rapid and reliable diagnostic techniques for penicillin non-susceptible S. pneumoniae (PNSSP) are important for prevention and treatment. We investigated the association of the restriction length polymorphism (RFLP) patterns for pbp2b to distinguish between penicillin susceptible and resistant S. pneumoniae isolates. Methods: In this study, a total of 70 pneumococcal isolates were collected from different clinical sources. MIC of these isolates was determined and pbp2b gene was amplified by PCR and they were digested by HaeІІІ enzyme. Results: Of the 70 isolates, 86% (60) and 14% (10) pneumococcal isolates were found to be PNSSP (penicillin intermediate S. pneumoniae (PISP) and penicillin resistant S. pneumoniae (PRSP)) and penicillin susceptible S. pneumoniae (PSSP). In addition, 10 RFLP patterns (A-J) which were ...
Microbial Drug Resistance, 1998
From January 1993 through December 1996,1,252 Streptococcus pneumoniae strains from different geographic regions of Brazil were studied for penicillin (Pen) susceptibility. All pneumococci were isolated from normally sterile fluids from patients, newborns to 88 years old. Pen resistance (R) had a mean rate of 15.1%, with 14.5% of strains showing intermediate level Pen-R and 0.6% showing high-level Pen-R. Similar Pen-R rates were observed in different regions of the country, in the range of 9.5% to 17.1%. A Pen-R increase was noted from 9.6% in 1993 to 20.6% in 1996. Pen-R was mostly associated to serotypes 6B, 14, 19A, and 23F (89%). Chromosomal DNA relatedness of Pen-R strains was determined by pulsed field gel electrophoresis (PFGE). High genetic diversity was identified, being represented by 27 patterns among the 92 strains. Two important features were observed: the predominance of relatively low-level Pen MIC (range 0.1-0.5 mg/L) in 86 of the 92 strains, and the presence of 60.8% as four major PFGE clusters unique to Brazil. Another feature was the geographic spread of these clusters over large distances in the country. The city of Säo Paulo seems to be a Pen-R focus (18.4%) in Brazil. Only two strains representing the international clone B widely spread in France, Portugal, and Spain, belonging to serotype 14, were found. 209 210 BRANDILEONE ET AL. tries such as South Africa,20 Hungary,22, and Spain21,24 and were shown to spread to other parts of the world (clonal spread), e.g., to the United States,23,36 Iceland,30 and Croatia.32 Such pneumococci with close genetic relatedness are referred to as the international clones of S. pneumoniae. In general, these clones comprise highly Pen-R-and multidrug-resistant strains and share a common capsular serotype.24,30,35
Annals of Microbiology, 2006
Eighty-nine penicillin-and ciprofloxacin-resistant Streptococcus pneumoniae isolates were evaluated by serotyping and pulsed-field gel electrophoresis. Although penicillin-resistant isolates demonstrated considerable homogeneity, resistance to ciprofloxacin did not correlate with a reduction in genotypic variability. These results suggest that, unlike that of penicillin resistance, the spread of S. pneumoniae ciprofloxacin resistance in Canada is currently not attributable to clonal dissemination. Clinical isolates of Streptococcus pneumoniae with reduced susceptibility to -lactams and fluoroquinolones may arise de novo or from the clonal spread of one or more resistant strains. Molecular surveillance of penicillin-and multidrug-resistant pneumococci from several countries has demonstrated that, in general, the majority of isolates circulating within a geographic area are derivatives of a relatively small number of clonal lineages (6, 7, 11). Few studies, however, have examined the molecular epidemiology of fluoroquinolone-nonsusceptible S. pneumoniae (1, 4, 10). The purpose of the present study was to compare the genetic relatedness between penicillin-and ciprofloxacin-resistant clinical isolates of S. pneumoniae within Canada. Eighty-nine clinical isolates of S.
Clinical Microbiology and Infection, 2007
A population-based nationwide surveillance of antibiotic resistance associated with invasive pneumococcal disease (IPD) in children and adolescents (aged <16 years) was performed in Germany between 1997 and 2004. In total, 1517 isolates were collected, of which 5.1% and 1.1% were intermediately-or fully-resistant, respectively, to penicillin G. During the 8-year study period, an increase in resistance to both penicillin G and erythromycin A was observed, and the frequency of isolates exhibiting reduced susceptibility to penicillin G or erythromycin A increased from 1.4% and 11.1%, respectively, in 1997, to 8.7% and 29.0%, respectively, in 2004. Among the penicillin non-susceptible pneumococcal isolates, serotypes 14 (24.5% of isolates), 23F (16.0%) and 6B (16.0%) were found most frequently. Multilocus sequence typing of 58 (62%) penicillin G non-susceptible isolates revealed that sequence type (ST) 156 (Spain 9V -3 clone) and its single-locus variant ST 557 were widespread in Germany. Moreover, 17 new penicillin G non-susceptible STs were defined for the first time. The study illustrated the genetic heterogeneity of antibiotic-resistant pneumococcal isolates in Germany.
Antimicrobial Agents and Chemotherapy, 1993
Streptococcus pneumoniae (the pneumococcus) is believed to have developed resistance to penicillin by the production of altered forms of penicillin-binding proteins (PBPs) that have decreased affinity for penicillin. Sixty-eight clinical isolates of serogroup 6 and 19 pneumococci (MICs, <0.015 to 8 ,ug/ml) were randomly selected from hospitals across South Africa which are at substantial geographic distance from each other. The polymerase chain reaction was used to isolate the penicillin-binding domain of PBPs 2B and 2X from the chromosomal DNAs of the bacteria; the purified PBP DNA was digested with restriction enzymes, the fragments were end-labelled and separated on polyacrylamide gels, and the DNA fingerprints were visualized following autoradiography. Fingerprint analysis revealed that at least 19 PBP 2B gene variants occur in the serogroup 6 and 19 pneumococci. The PBP 2B gene revealed a uniform profile among penicillin-susceptible isolates, with variation from this profile occurring only in isolates for which MICs were .0.06,ug/ml.
Journal of clinical microbiology, 1998
Restriction digest profiling of pneumococcal pbp2b-specific amplicons was effective for screening penicillin resistance. The pbp2b amplicon of all pneumococcal isolates for which the MICs of penicillin were < or = 0.03 microgram/ml had one of two different susceptible restriction profiles, and all 33 isolates for which MICs were 0.5 microgram/ml or greater had one of seven distinct resistant profiles. Low-concentration penicillin resistance (MICs = 0.06 microgram/ml to 0.25 microgram/ml) was associated with sensitive HaeIII profiles in some isolates; however, RsaI profiling and pbp2b sequence analysis of such isolates revealed that some isolates contained low-level resistant pbp2b alleles, while others had susceptible pbp2b alleles. This data indicates that low-level penicillin resistance is sometimes conferred by determinants other than pbp2b.
Genetics of high level penicillin resistance in clinical isolates of Streptococcus pneumoniae
FEMS Microbiology Letters, 1995
Mosaic penicillin-binding proteins (PBP) lA, 2X and 2B genes were cloned from four clinical isolates of Streptococcus pneumoniue with levels of susceptibility to penicillin ranging from 1.5 to 16 pg benzylpenicillin ml-'. In each instance it was possible to transform either the penicillin-sensitive laboratory strain R6 or a sensitive clinical isolate llOK/70 to the full level of penicillin resistance with these three penicillin-binding proteins alone. Until now it has not been possible to clearly determine whether alterations to PBPlA, 2X and 2B alone were sufficient to attain high level penicillin resistance.