The Key Role of Pulsed-Field Gel Electrophoresis in Investigation of a Large Multiserotype and Multistate Food-Borne Outbreak of
            <i>Salmonella</i>
            Infections Centered in Pennsylvania

d Salmonella enterica subsp. enterica serovar Newport (S. Newport) is the third most prevalent cause of food-borne salmonellosis. Rapid, efficient, and accurate methods for identification are required to track specific strains of S. Newport during outbreaks. By exploiting the hypervariable nature of virulence genes and clustered regularly interspaced short palindromic repeats (CRISPRs), we previously developed a sequence-based subtyping approach, designated CRISPR-multi-virulence-locus sequence typing (CRISPR-MVLST). To demonstrate the applicability of this approach, we analyzed a broad set of S. Newport isolates collected over a 5-year period by using CRISPR-MVLST and pulsed-field gel electrophoresis (PFGE). Among 84 isolates, we defined 38 S. Newport sequence types (NSTs), all of which were novel compared to our previous analyses, and 62 different PFGE patterns. Our data suggest that both subtyping approaches have high discriminatory abilities (>0.95) with a potential for clustering cases with common exposures. Importantly, we found that isolates from closely related NSTs were often similar by PFGE profile as well, further corroborating the applicability of CRISPR-MVLST. In the first full application of CRISPR-MVLST, we analyzed isolates from a recent S. Newport outbreak. In this blinded study, we confirmed the utility of CRISPR-MVLST and were able to distinguish the 10 outbreak isolates, as defined by PFGE and epidemiological data, from a collection of 20 S. Newport isolates. Together, our data show that CRISPR-MVLST could be a complementary approach to PFGE subtyping for S. Newport.

show abstract

“…DNA samples were stored at Ϫ20°C prior to PCR analysis. PFGE-XbaI analysis of all isolates was performed using standard protocols (35,36).…”

Section: Methodsmentioning

confidence: 99%

Subtyping of Salmonella enterica Serovar Newport Outbreak Isolates by CRISPR-MVLST and Determination of the Relationship between CRISPR-MVLST and PFGE Results

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…The perfect identity of virulence gene profiles and Shiga toxin sequences among the two sets of 2006 outbreak isolates prompted us to investigate strain relatedness using PFGE as described previously (20) (Fig. 1).…”

mentioning

confidence: 99%

Characterization of Shiga Toxin-Producing Escherichia coli Isolates Associated with Two Multistate Food-Borne Outbreaks That Occurred in 2006

Uhlich

Sinclair

Warren

et al. 2008

Appl Environ Microbiol

View full text Add to dashboard Cite

Shiga toxin-producing Escherichia coli isolates from two 2006 outbreaks were compared to other O157:H7 isolates for virulence genotype, biofilm formation, and stress responses. Spinach-and lettuce-related-outbreak strains had similar pulsed-field gel electrophoresis patterns, and all carried both stx 2 and stx 2c variant genes. Cooperative biofilm formation involving an E. coli O157:H7 strain and a non-O157:H7 strain was also demonstrated.

show abstract

“…Native animals and wildlife have been implicated in previous communitywide outbreaks of salmonellosis (5,6). Outbreaks of Salmonella infections have been caused by foods of animal origin, and poultry and poultry products such as eggs are considered to be the most important food vehicles for S. enteritidis infections (7,8).…”

Section: Discussionmentioning

confidence: 99%

A Food-Borne Outbreak of Gastroenteritis Caused by Different <i>Salmonella</i> Serotypes in 2 Universities in Xiamen, Fujian, China, in 2012

Guo

Huang

et al. 2015

Jpn J Infect Dis

View full text Add to dashboard Cite

SUMMARY:We investigated a diarrhea outbreak in 2 universities to identify the etiological agent responsible, the source of infection, the mode of transmission, and the risk factors. A case-controlled study was conducted using case students and asymptomatic control students who were selected randomly and frequency-matched according to class and age, and the source of food or water intake was investigated. Of the total 22,404 students at the universities, 0.25z developed Salmonella Infections. A total of 96z (54/56) of the case students and 30z (35/117) of the control students consumed bread products provided by the same vendor (odds ratio [OR] ＝ 63.3; 95z confidence interval [CI], 14.9-550.7). Among the students who consumed bread, 96z (52/54) of the case students and 9z (3/35) of the control students ate egg sandwiches (OR ＝ 277.3; 95zCI, 43.9-1,750.8). Seven strains of Salmonella enteritidis and 6 strains of S. chester were isolated from the case students or food samples. Pulsed-field gel electrophoresis typing showed the same patterns. The outbreak of gastroenteritis was caused mainly by egg sandwiches contaminated with different serotypes of Salmonella.

show abstract

The Key Role of Pulsed-Field Gel Electrophoresis in Investigation of a Large Multiserotype and Multistate Food-Borne Outbreak of Salmonella Infections Centered in Pennsylvania

Cited by 35 publications

References 23 publications

Subtyping of Salmonella enterica Serovar Newport Outbreak Isolates by CRISPR-MVLST and Determination of the Relationship between CRISPR-MVLST and PFGE Results

Subtyping of Salmonella enterica Serovar Newport Outbreak Isolates by CRISPR-MVLST and Determination of the Relationship between CRISPR-MVLST and PFGE Results

Characterization of Shiga Toxin-Producing Escherichia coli Isolates Associated with Two Multistate Food-Borne Outbreaks That Occurred in 2006

A Food-Borne Outbreak of Gastroenteritis Caused by Different <i>Salmonella</i> Serotypes in 2 Universities in Xiamen, Fujian, China, in 2012

Contact Info

Product

Resources

About