Molecular characterisation of Canadian paediatric multidrug-resistant Streptococcus pneumoniae from 1998–2004

Zhanel, George G.; Xi, Wang; Nichol, Kim; Nikulin, A.; Wierzbowski, Aleksandra; Mulvey, Michael R.; Hoban, Daryl J.

doi:10.1016/j.ijantimicag.2006.08.005

Cited by 26 publications

(22 citation statements)

References 15 publications

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“…Mutations associated with elevated minimal inhibitory concentrations (MIC) have been described for key antibiotics commonly used to treat both invasive and non-invasive SPN infection [1,15,18,19]. DNA sequence analysis for key resistance-conferring residues in penicillin binding proteins ( pbp ) 2x , 1 a , and 2b showed conservation between MDR 19A (this study), MDR 19F (this study), and MDR 19A from US and Korea (Table 6).…”

Section: Resultsmentioning

confidence: 99%

“…Second, MDR 19A existed before the implementation of PCV7 and has simply replaced vaccine serotypes (VS) targeted by PCV7 [14]. Third, MDR 19A has attained conserved genetic markers which confer resistance to antibiotics commonly used in the treatment of Streptococcus pneumoniae (SPN) invasive pneumococcal disease (IPD) [15]. These genetic markers are missing in the drug susceptible SPN 19A isolates, such as those belonging to sequence type 199.…”

Section: Introductionmentioning

confidence: 99%

“…Chief amongst these antibiotics conferred resistance to, are β-lactams and macrolides. Resistance to these drugs likely confers a fitness advantage to the organism at the population level where antibiotics are commonly dispensed [15]. Of note, high-level penicillin resistance has been mainly associated with serotypes 6A, 6B, 9V, 14, 19A, 19F, and 23F [1].…”

Section: Introductionmentioning

confidence: 99%

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Genome-wide dissection of globally emergent multi-drug resistant serotype 19A Streptococcus pneumoniae

Pillai

Shahinas

Buzina³

et al. 2009

BMC Genomics

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BackgroundEmergence of multi-drug resistant (MDR) serotype 19A Streptococcus pneumoniae (SPN) is well-documented but causal factors remain unclear. Canadian SPN isolates (1993-2008, n = 11,083) were serotyped and in vitro susceptibility tested. A subset of MDR 19A were multi-locus sequence typed (MLST) and representative isolates' whole genomes sequenced.ResultsMDR 19A increased in the post-PCV7 era while 19F, 6B, and 23F concurrently declined. MLST of MDR 19A (n = 97) revealed that sequence type (ST) 320 predominated. ST320 was unique amongst MDR 19A in that its minimum inhibitory concentration (MIC) values for penicillin, amoxicillin, ceftriaxone, and erythromycin were higher than for other ST present amongst post-PCV7 MDR 19A. DNA sequencing revealed that alleles at key drug resistance loci pbp2a, pbp2x, pbp2b, ermB, mefA/E, and tetM were conserved between pre-PCV7 ST 320 19F and post-PCV7 ST 320 19A most likely due to a capsule switch recombination event. A genome wide comparison of MDR 19A ST320 with MDR 19F ST320 identified 822 unique SNPs in 19A, 61 of which were present in antimicrobial resistance genes and 100 in virulence factors.ConclusionsOur results suggest a complex genetic picture where high-level drug resistance, vaccine selection pressure, and SPN mutational events have created a "perfect storm" for the emergence of MDR 19A.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Genome-wide dissection of globally emergent multi-drug resistant serotype 19A Streptococcus pneumoniae

Pillai

Shahinas

Buzina³

et al. 2009

BMC Genomics

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“…The erm (B) encoded methylation of the ribosomal macrolide target site, which confers high-level macrolide resistance as well as resistance to lincosamides and streptogramin B (MLS B phenotype), is the prevalent mechanism in some Asian, European, Middle Eastern, and African countries [6,9-13]. The mef encoded efflux pump conferring low-level macrolide resistance (M phenotype) is more prevalent in other Asian and European countries and North America [9,14-16]. …”

Section: Introductionmentioning

confidence: 99%

Dominance of multidrug resistant CC271 clones in macrolide-resistant streptococcus pneumoniae in Arizona

et al. 2012

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BackgroundRates of resistance to macrolide antibiotics in Streptococcus pneumoniae are rising around the world due to the spread of mobile genetic elements harboring mef(E) and erm(B) genes and post-vaccine clonal expansion of strains that carry them.ResultsCharacterization of 592 clinical isolates collected in Arizona over a 10 year period shows 23.6% are macrolide resistant. The largest portion of the macrolide-resistant population, 52%, is dual mef(E)/erm(B)-positive. All dual-positive isolates are multidrug-resistant clonal lineages of Taiwan19F-14, mostly multilocus sequence type 320, carrying the recently described transposon Tn2010. The remainder of the macrolide resistant S. pneumoniae collection includes 31% mef(E)-positive, and 9% erm(B)-positive strains.ConclusionsThe dual-positive, multidrug-resistant S. pneumoniae clones have likely expanded by switching to non-vaccine serotypes after the heptavalent pneumococcal conjugate vaccine release, and their success limits therapy options. This upsurge could have a considerable clinical impact in Arizona.

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“…The mega element, which was 5.5 kb in size, was inserted at several chromosomal sites in Streptococcus (27). The presence of a mega element is the most prevalent mechanism of Streptococcus pneumoniae macrolide resistance in the United States, Canada, and the United Kingdom (28). The last block, with a length of 7 kb, showed 99% similarity with Tn558 and included the florfenicol-chloramphenicol transporter FexA, transposase, and a putative oxidoreductase.…”

Section: Figmentioning

confidence: 99%

Characterization of a Multiresistant Mosaic Plasmid from a Fish Farm Sediment Exiguobacterium sp. Isolate Reveals Aggregation of Functional Clinic-Associated Antibiotic Resistance Genes

Yang

Wang

et al. 2014

Appl Environ Microbiol

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bThe genus Exiguobacterium can adapt readily to, and survive in, diverse environments. Our study demonstrated that Exiguobacterium sp. strain S3-2, isolated from marine sediment, is resistant to five antibiotics. The plasmid pMC1 in this strain carries seven putative resistance genes. We functionally characterized these resistance genes in Escherichia coli, and genes encoding dihydrofolate reductase and macrolide phosphotransferase were considered novel resistance genes based on their low similarities to known resistance genes. The plasmid G؉C content distribution was highly heterogeneous. Only the G؉C content of one block, which shared significant similarity with a plasmid from Exiguobacterium arabatum, fit well with the mean G؉C content of the host. The remainder of the plasmid was composed of mobile elements with a markedly lower G؉C ratio than the host. Interestingly, five mobile elements located on pMC1 showed significant similarities to sequences found in pathogens. Our data provided an example of the link between resistance genes in strains from the environment and the clinic and revealed the aggregation of antibiotic resistance genes in bacteria isolated from fish farms.

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Molecular characterisation of Canadian paediatric multidrug-resistant Streptococcus pneumoniae from 1998–2004

Cited by 26 publications

References 15 publications

Genome-wide dissection of globally emergent multi-drug resistant serotype 19A Streptococcus pneumoniae

Genome-wide dissection of globally emergent multi-drug resistant serotype 19A Streptococcus pneumoniae

Dominance of multidrug resistant CC271 clones in macrolide-resistant streptococcus pneumoniae in Arizona

Characterization of a Multiresistant Mosaic Plasmid from a Fish Farm Sediment Exiguobacterium sp. Isolate Reveals Aggregation of Functional Clinic-Associated Antibiotic Resistance Genes

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