scholarly journals Coexistence of Multiple Multilocus Variable-Number Tandem-Repeat Analysis Subtypes ofClostridium difficilePCR Ribotype 027 Strains within Fecal Specimens

2010 ◽  
Vol 48 (3) ◽  
pp. 985-987 ◽  
Author(s):  
Hannah E. Tanner ◽  
Katherine J. Hardy ◽  
Peter M. Hawkey
Keyword(s):  
Tandem Repeat ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Repeat Analysis ◽  
Ribotype 027

scholarly journals Multilocus Variable-Number Tandem-Repeat Analysis of Clostridioides difficile Clusters in Ribotype 027 Isolates and Lack of Association with Clinical Outcomes

2019 ◽  
Vol 57 (5) ◽  
Author(s):  
Julian R. Garneau ◽  
Claire Nour Abou Chakra ◽  
Louis-Charles Fortier ◽  
Annie-Claude Labbé ◽  
Andrew E. Simor ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Tandem Repeat ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Content Type ◽  
Repeat Analysis ◽  
Ribotype 027 ◽  
Clostridioides Difficile ◽  
Significant Difference ◽  
Pcr Ribotyping

ABSTRACT The epidemiology of Clostridioides difficile infection (CDI) has drastically changed since the emergence of the epidemic strain BI/NAP1/027, also known as ribotype 027 (R027). However, the relationship between the infecting C. difficile strain and clinical outcomes is still debated. We hypothesized that certain subpopulations of R027 isolates could be associated with unfavorable outcomes. We applied high-resolution multilocus variable-number tandem-repeat analysis (MLVA) to characterize C. difficile R027 isolates collected from confirmed CDI patients recruited across 10 Canadian hospitals from 2005 to 2008. PCR ribotyping was performed first to select R027 isolates that were then analyzed by MLVA (n = 450). Complicated CDI (cCDI) was defined by the occurrence of any of admission to an intensive care unit, colonic perforation, toxic megacolon, colectomy, and if CDI was the cause or contributed to death within 30 days after enrollment. Three major MLVA clusters were identified, MC-1, MC-3, and MC-10. MC-1 and MC-3 were exclusive to Quebec centers, while MC-10 was found only in Ontario. Fewer cases infected with MC-1 developed cCDI (4%) than those infected with MC-3 and MC-10 (15% and 16%, respectively), but a statistically significant difference was not reached. Our data did not identify a clear association between subpopulations of R027 and different clinical outcomes; however, the data confirmed the utility of MLVA’s higher discrimination potential to better characterize CDI populations in an epidemiological analysis. For a patient with CDI, the progression toward an unfavorable outcome is a complex process that probably includes several interrelated strain and host characteristics.

scholarly journals Multiple-Locus Variable-Number Tandem Repeat Analysis of Dutch Bordetella pertussis Strains Reveals Rapid Genetic Changes with Clonal Expansion during the Late 1990s

2004 ◽  
Vol 186 (16) ◽  
pp. 5496-5505 ◽  
Author(s):  
Leo M. Schouls ◽  
Han G. J. van der Heide ◽  
Luc Vauterin ◽  
Paul Vauterin ◽  
Frits R. Mooi
Keyword(s):  
The Netherlands ◽  
Tandem Repeat ◽  
Bordetella Pertussis ◽  
Minimum Spanning Tree ◽  
Whooping Cough ◽  
Variable Number Tandem Repeat ◽  
Clonal Expansion ◽  
Variable Number ◽  
Multiple Locus ◽  
Repeat Analysis

ABSTRACT Bordetella pertussis, the causative agent of whooping cough, has remained endemic in The Netherlands despite extensive nationwide vaccination since 1953. In the 1990s, several epidemic periods have resulted in many cases of pertussis. We have proposed that strain variation has played a major role in the upsurges of this disease in The Netherlands. Therefore, molecular characterization of strains is important in identifying the causes of pertussis epidemiology. For this reason, we have developed a multiple-locus variable-number tandem repeat analysis (MLVA) typing system for B. pertussis. By combining the MLVA profile with the allelic profile based on multiple-antigen sequence typing, we were able to further differentiate strains. The relationships between the various genotypes were visualized by constructing a minimum spanning tree. MLVA of Dutch strains of B. pertussis revealed that the genotypes of the strains isolated in the prevaccination period were diverse and clearly distinct from the strains isolated in the 1990s. Furthermore, there was a decrease in diversity in the strains from the late 1990s, with a remarkable clonal expansion that coincided with the epidemic periods. Using this genotyping, we have been able to show that B. pertussis is much more dynamic than expected.

Multiplex Multilocus Variable-Number Tandem-Repeat Analysis for Typing of PandemicVibrio parahaemolyticusO1:KUT Isolates

2019 ◽  
Vol 16 (2) ◽  
pp. 104-113 ◽  
Author(s):  
Sutima Preeprem ◽  
Kamonnut Singkhamanan ◽  
Mitsuaki Nishibuchi ◽  
Varaporn Vuddhakul ◽  
Pimonsri Mittraparp-arthorn
Keyword(s):  
Tandem Repeat ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Repeat Analysis
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