Multiple-locus variable-number tandem repeat analysis of Salmonella enterica subsp. enterica serovar Typhimurium: comparison of isolates from pigs, poultry and cases of human gastroenteritis

2007 ◽  
Vol 103 (3) ◽  
pp. 565-572 ◽  
Author(s):  
E.L. Best ◽  
B.-A. Lindstedt ◽  
A. Cook ◽  
F.A. Clifton Hadley ◽  
E.J. Threlfall ◽  
...  
Keyword(s):  
Tandem Repeat ◽  
Salmonella Enterica ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Multiple Locus ◽  
Repeat Analysis ◽  
Serovar Typhimurium

Characterization of Salmonella enterica Serovar Typhimurium Isolates from Pigs and Pig Environment–Related Sources and Evidence of New Circulating Monophasic Strains in Spain

2016 ◽  
Vol 79 (3) ◽  
pp. 407-412 ◽  
Author(s):  
SARA ANDRÉS-BARRANCO ◽  
JUAN PABLO VICO ◽  
CLARA MARÍA MARÍN ◽  
SILVIA HERRERA-LEÓN ◽  
RAÚL CARLOS MAINAR-JAIME
Keyword(s):  
Multidrug Resistance ◽  
Tandem Repeat ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Multiple Locus ◽  
Repeat Analysis ◽  
Major Cluster ◽  
Serovar Typhimurium

ABSTRACT A total of 117 Salmonella enterica serovar Typhimurium and 59 monophasic Salmonella Typhimurium (S. enterica serovar 4,[5],12:i:–) strains isolated between 2008 and 2012 from pig, wild bird, rodent, and farm environment samples from the northeast of Spain were characterized by phage typing, antibiotic susceptibility testing, and multiple-locus variable-number tandem repeat analysis in order to evaluate their phenotypic and genetic relatedness. In Salmonella 4,[5],12:i:–, the most prevalent phage types were U311 (40.7%) and DT195 (22%), which did not correspond with the so-called Spanish clone and generally showed a different resistance pattern (ASSuT). Antibiotic resistance was found in 85.8% of the isolates, with 94.1% of them displaying multidrug resistance. Multiple-locus variable-number tandem repeat analysis identified 92 different profiles, six of them shared by both serovars. The minimum spanning tree showed one major cluster that included 95% of the Salmonella 4,[5],12:i:– isolates, which came from different animal sources, geographic locations, and time periods, suggesting high clonality among those Salmonella strains and the ability to spread among pig farms. Overall, isolates of Salmonella 4,[5],12:i:– were more similar to European strains than to the well-characterized Spanish clone. The spread of these new strains of Salmonella 4,[5],12:i:– would likely have been favored by the important pig trade between this Spanish region and other European countries. The overall high prevalence of multidrug resistance observed in these new strains should be noted.

Multiple-locus variable-number tandem-repeat analysis for discriminating withinSalmonella entericaserovar Typhimurium definitive types and investigation of outbreaks

2010 ◽  
Vol 139 (7) ◽  
pp. 1050-1059 ◽  
Author(s):  
K. H. DYET ◽  
E. TURBITT ◽  
P. E. CARTER
Keyword(s):  
Tandem Repeat ◽  
Phage Type ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Common Source ◽  
Reference Laboratory ◽  
Multiple Locus ◽  
Repeat Analysis ◽  
Phage Types ◽  
Serovar Typhimurium

SUMMARYThe discriminatory power of multiple-locus variable-number tandem-repeat analysis (MLVA) needs to be evaluated for allSalmonella entericasubspeciesentericaserovar Typhimurium (S. Typhimurium) phage types so that the power of this methodology is understood and results can be interpreted correctly during outbreak investigations. We evaluated the ability of MLVA to characterize four definitive phage types (DT) problematic in New Zealand. MLVA discriminated between DT104 isolates although there was very limited variation in the MLVA profiles for isolates with an RDNC phage type (reacts but does not conform to a recognized Typhimurium phage pattern) first observed in New Zealand's Enteric Reference Laboratory in May 2006. Most DT101 isolates had indistinguishable MLVA profiles or profiles that differed at one or two loci. This was also observed in DT160 isolates. MLVA may not identify all common-source outbreaks although it provided valuable data when applied to case isolates from twoS. Typhimurium outbreaks.

scholarly journals Multiple-locus variable-number tandem repeat analysis of Salmonella enterica subsp. enterica serovar Dublin

2014 ◽  
Vol 116 (4) ◽  
pp. 1044-1054 ◽  
Author(s):  
M.K. Kjeldsen ◽  
M. Torpdahl ◽  
J. Campos ◽  
K. Pedersen ◽  
E.M. Nielsen
Keyword(s):  
Tandem Repeat ◽  
Salmonella Enterica ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Multiple Locus ◽  
Repeat Analysis

scholarly journals Multilocus Variable-Number Tandem-Repeat Analysis and Plasmid Profiling To Study the Occurrence of blaCMY-2 within a Pulsed-Field Gel Electrophoresis-Defined Clade of Salmonella enterica Serovar Typhimurium

2009 ◽  
Vol 76 (1) ◽  
pp. 69-74 ◽  
Author(s):  
B. Adhikari ◽  
T. E. Besser ◽  
J. M. Gay ◽  
L. K. Fox ◽  
D. D. Hancock ◽  
...  
Keyword(s):  
Tandem Repeat ◽  
Salmonella Enterica ◽  
Human Health Risk ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Repeat Analysis ◽  
Animal Populations ◽  
Serovar Typhimurium ◽  
Cephalosporin Resistance ◽  
Plasmid Profiling

ABSTRACT Salmonella enterica serovar Typhimurium circulating in food animal populations and carrying resistance to antimicrobial agents represents a human health risk. Recently, a new clade of S. Typhimurium, WA-TYP035/187, was reported in cattle and humans in the Pacific Northwest, United States of America. The objective of this study was to describe a possible mechanism of acquisition of expanded-spectrum cephalosporin resistance in this clade. Ceftazidime resistance increased steadily among WA-TYP035/187 isolates, from 0% (0/2) in 1999 to 77.8% (28/36) in 2006 (χ2 for linear trend, P value of <0.001). Among 112 bovine-source and 18 human-source isolates, 49 (43.8%) and 12 (66.7%) were resistant to ceftazidime, respectively. Multiple-locus variable-number tandem-repeat analysis (MLVA) and plasmid profiling suggested that resistance was acquired by multiple independent genetic events within the WA-TYP035/187 clade. Given the lack of an obvious reservoir in species other than cattle and a parallel rise in ceftiofur resistance in the bovine-specific serovar S almonella enterica serovar Dublin in the same time frame and region, selection pressure due to the use of the expanded-spectrum cephalosporin drug ceftiofur in cattle is a likely factor driving the increasing cephalosporin resistance of WA-TYP035/187.

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