Phenotypic and molecular characterization of β-lactams resistance and capsular typing of colonizing Haemophilus influenzae strains isolated from neutropenic patients in Tunisia

2009 ◽  
Vol 57 (5) ◽  
pp. 353-357 ◽  
Author(s):  
A. Touati ◽  
W. Achour ◽  
A. Ben Hassen
Keyword(s):  
Haemophilus Influenzae ◽  
Molecular Characterization ◽  
Neutropenic Patients ◽  
Capsular Typing

scholarly journals Molecular Characterization of Pneumococcal Nasopharynx Isolates Collected from Children during Their First 2 Years of Life

1998 ◽  
Vol 36 (8) ◽  
pp. 2248-2253 ◽  
Author(s):  
Marcel Sluijter ◽  
Howard Faden ◽  
Ronald de Groot ◽  
Nicole Lemmens ◽  
Wil H. F. Goessens ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Horizontal Transfer ◽  
Capsular Type ◽  
Penicillin Binding Protein ◽  
Resistant Strains ◽  
Pneumococcal Colonization ◽  
Different Strains ◽  
Culture Positive ◽  
Capsular Typing

Pneumococcal colonization was studied in 19 children monitored from birth through the age of 2 years. For this purpose, pneumococcal isolates were characterized by capsular typing, restriction fragment end labeling (RFEL), and penicillin-binding protein (PBP) genotyping. Fifty-eight isolates were collected and were found to belong to 10 capsular types, 31 RFEL types, and 7 PBP genotypes. Thirty-nine percent of the isolates had reduced susceptibility to penicillin. All seven highly resistant strains (MICs, >1 μg/ml) were identical to the pandemic clone 23F. Children were culture positive between one and eight times at 13 scheduled visits. Although the infants were frequently recolonized with different strains, colonization with one particular strain often persisted for several months. Isolation of a previously detected capsular type was common, and the chromosomal homogeneity tended to be high when it occurred. Horizontal transfer of capsular genes between strains of different RFEL types was demonstrated in one child. The ecological advantage of transfer of capsular genes is unclear unless survival of the organism on a mucosal surface may be linked to immunoprotective pressure against particular capsular types.

Molecular Characterization of Resistance Plasmids in Epidemiologically Unrelated Strains of Multiresistant Haemophilus influenzae

1993 ◽  
Vol 168 (1) ◽  
pp. 177-187 ◽  
Author(s):  
Jack Levy ◽  
Godelieve Verhaegen ◽  
Patrick De Mol ◽  
Martine Couturier ◽  
Daniel Dekegel ◽  
...  
Keyword(s):  
Haemophilus Influenzae ◽  
Molecular Characterization ◽  
Resistance Plasmids

scholarly journals Rapid identification, capsular typing and molecular characterization of Streptococcus pneumoniae by using whole genome nanopore sequencing

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
S. Garcia-Garcia ◽  
A. Perez-Arguello ◽  
D. Henares ◽  
N. Timoneda ◽  
C. Muñoz-Almagro
Keyword(s):  
Streptococcus Pneumoniae ◽  
Whole Genome Sequencing ◽  
Real Time ◽  
Molecular Characterization ◽  
Genome Sequencing ◽  
Rapid Identification ◽  
Whole Genome ◽  
Genomic Epidemiology ◽  
Capsular Typing

Abstract Background Whole genome sequencing has emerged as a useful tool for identification and molecular characterization of pathogens. MinION (Oxford Nanopore) is a real-time third generation sequencer whose portability, affordability and speed in data production make of it an attractive device for whole genome sequencing. The objective of this study is to evaluate MinION sequencer for pathogen identification and molecular characterization of Streptococcus pneumoniae isolated at a children’s Hospital. Whole genome sequencing of 32 Streptococcus pneumoniae invasive isolates, previously characterized by standard methods (Quellung reaction, Multiplex PCR and Sanger-MLST), were performed. DNA was extracted using ZymoBIOMICS DNA Microprep kit. Quantification and purity of DNA was assessed by Qubit and Nanodrop, respectively. Library preparation was performed using the Rapid Barcoding Kit. Real-time workflow EPI2ME platform “What’s it in my pot” was used for species identification. Fast5 sequences were converted into FASTQ by Albacore software. Reads were assembled using CANU software. PathogenWatch, genomic epidemiology and pubmlst online tools were used for capsular typing and/or whole genome-MLST profile. Results Rapid identification of Streptococcus pneumoniae was achieved by “What’s in my pot”. Capsular typing was correctly assigned with PathogenWatch in all 32 isolates at serogroup level and 24 at serotype level. Whole genome-MLST results obtained by genomic epidemiology and pubmlst were consistent with double locus variant clonal complex obtained by Sanger-MLST in 31 isolates. Conclusion MinION sequencer provides a rapid, cost-effective and promising pathway for performing WGS by a pocked-sized device for epidemiological purposes but improving its sequencing accuracy will make it more appealing to be used in clinical microbiology laboratories.

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