scholarly journals AT Homopolymer Strings in Salmonella enterica Subspecies I Contribute to Speciation and Serovar Diversity

2021 ◽  
Vol 9 (10) ◽  
pp. 2075
Author(s):  
Jean Guard ◽  
Adam Rivers ◽  
Justin Vaughn ◽  
Michael Rothrock ◽  
Adelumola Oladeinde ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Foodborne Illness ◽  
Gene Content ◽  
Plasmid Content ◽  
Self Recognition ◽  
Salmonella Serovars ◽  
New Framework

Adenine and thymine homopolymer strings of at least 8 nucleotides (AT 8+mers) were characterized in Salmonella enterica subspecies I. The motif differed between other taxonomic classes but not between Salmonella enterica serovars. The motif in plasmids was possibly associated with serovar. Approximately 12.3% of the S. enterica motif loci had mutations. Mutability of AT 8+mers suggests that genomes undergo frequent repair to maintain optimal gene content, and that the motif facilitates self-recognition; in addition, serovar diversity is associated with plasmid content. A theory that genome regeneration accounts for both persistence of predominant Salmonella serovars and serovar diversity provides a new framework for investigating root causes of foodborne illness.

scholarly journals AT Homopolymer Strings as a Motif for Self-Recognition and Repair of Genomes in Salmonella enterica Subspecies I

2021 ◽  
Author(s):  
Jean Guard ◽  
Adam R Rivers ◽  
Justin N Vaughn ◽  
Michael J Rothrock, Jr ◽  
Adelumola Oladeinde ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Foodborne Illness ◽  
Gene Content ◽  
Self Recognition ◽  
Salmonella Serovars ◽  
New Framework ◽  
Genome Repair

Adenine and thymine homopolymer strings of at least 8 nucleotides (AT 8+mers) were charac-terized in Salmonella enterica subspecies I and other Eubacteria. Incidence of the motif differed between Eubacteria but not between Salmonella enterica serotypes. Of 481 AT 8+mers loci in serovars Typhimurium, Enteritidis, and Gallinarum, 35 (12.3%) had mutations. We propose that the AT 8+mer motif identifies genomes with optimal gene content and provides self-recognition that facilitates efficient genome repair. A theory that genome regeneration accounts for both serovar diversity and persistence of predominant Salmonella serovars associated provides a new framework for investigating root causes of foodborne illness.

scholarly journals Molecular Analyses of Salmonellaenterica Isolates from Fish Feed Factories and Fish Feed Ingredients

2003 ◽  
Vol 69 (2) ◽  
pp. 1075-1081 ◽  
Author(s):  
Live L. Nesse ◽  
Kerstin Nordby ◽  
Even Heir ◽  
Bjarne Bergsjoe ◽  
Traute Vardund ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Salmonella Enterica ◽  
Profile Analysis ◽  
Plasmid Profile ◽  
Pulsed Field Gel Electrophoresis ◽  
Fish Feed ◽  
Molecular Analyses ◽  
Feed Ingredients ◽  
Pulsed Field ◽  
Salmonella Serovars

ABSTRACT Isolates of the most commonly observed salmonella serovars in Norwegian fish feed factories from 1998 to 2000 (Salmonella enterica serovar Agona, S. enterica serovar Montevideo, S. enterica serovar Senftenberg, and S. enterica serovar Kentucky) were studied by pulsed-field gel electrophoresis (PFGE) and plasmid profile analysis and compared to isolates of the same serovars from fish feed ingredients, humans, and other sources (a total of 112 isolates). Within each serovar, a variety of distinct PFGE types (with similarity levels less than 90%) were observed in the feed ingredients and other sources, while only two distinct types of each serovar were identified in the factories. The combined results of PFGE and plasmid analyses showed that each factory harbored only a few S. enterica clones. Some of these clones persisted for at least 3 years in the factories, indicating that there was long-lasting contamination probably due to inadequate decontamination procedures.

Identification of Salmonella enterica Serovar Typhimurium Using Specific PCR Primers Obtained by Comparative Genomics in Salmonella Serovars

2006 ◽  
Vol 69 (7) ◽  
pp. 1653-1661 ◽  
Author(s):  
H. J. KIM ◽  
S. H. PARK ◽  
T. H. LEE ◽  
B. H. NAHM ◽  
Y. H. CHUNG ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Salmonella Enterica ◽  
Target Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Foodborne Pathogen ◽  
Pcr Primers ◽  
Genomic Sequences ◽  
Local Alignment ◽  
Serovar Typhimurium ◽  
Salmonella Serovars

Salmonella enterica serovar Typhimurium is a major foodborne pathogen throughout the world. Until now, the specific target genes for the detection and identification of serovar Typhimurium have not been developed. To determine the specific probes for serovar Typhimurium, the genes of serovar Typhimurium LT2 that were expected to be unique were selected with the BLAST (Basic Local Alignment Search Tool) program within GenBank. The selected genes were compared with 11 genomic sequences of various Salmonella serovars by BLAST. Of these selected genes, 10 were expected to be specific to serovar Typhimurium and were not related to virulence factor genes of Salmonella pathogenicity island or to genes of the O and H antigens of Salmonella. Primers for the 10 selected genes were constructed, and PCRs were evaluated with various genomic DNAs of Salmonella and non-Salmonella strains for the specific identification of Salmonella serovar Typhimurium. Among all the primer sets for the 10 genes, STM4497 showed the highest degree of specificity to serovar Typhimurium. In this study, a specific primer set for Salmonella serovar Typhimurium was developed on the basis of the comparison of genomic sequences between Salmonella serovars and was validated with PCR. This method of comparative genomics to select target genes or sequences can be applied to the specific detection of microorganisms.

scholarly journals Salmonella enterica serovars associated with bacteremia in Canada, 2006–2019

2021 ◽  
Vol 47 (56) ◽  
pp. 259-268
Author(s):  
Sandeep Tamber ◽  
Brendan Dougherty ◽  
Kimberly Nguy
Keyword(s):  
Organ Failure ◽  
Salmonella Enterica ◽  
Surveillance Program ◽  
Bacterial Genus ◽  
Salmonella Infections ◽  
Clinical Presentations ◽  
Salmonella Serovars

Background: Members of the bacterial genus Salmonella cause salmonellosis, a disease with a spectrum of clinical presentations from a self-limiting gastroenteritis to more severe bacteremia, organ failure and sepsis. The genus consists of over 2,600 serological variants (serovars). Important differences in the pathogenesis of Salmonella serovars have been noted. Objective: The purpose of this study was to determine which Salmonella serovars were more likely to be associated with bacteremia in Canada. Methods: Information on the total number of Salmonella infections and blood isolations reported to the National Enteric Surveillance Program (NESP) from 2006 to 2019 was extracted for each serovar. The risk (proportion) and likelihood (odds) of bacteremia were calculated for all serovars. Results: Of the 96,082 Salmonella cases reported to the NESP during the 14-year study period, 4.4% (95% CI: 4.3%–4.6%) were bacteremic. Twenty nontyphoidal Salmonella (NTS) serovars were associated with lower rates of bacteremia compared to all NTS serovars, and 19 NTS serovars were identified as having higher rates. Heidelberg, Oranienburg, Schwarzengrund, Virchow, Panama and Poona among the top 25 most commonly reported serovars in Canada during the study period. Conclusion: The identification of serovars associated with Salmonella bacteremia in Canada is a first step towards understanding differences in pathogenesis and disease presentation.

scholarly journals Salmonella Serovars in the Herpetofauna of Indiana County, Pennsylvania

2006 ◽  
Vol 72 (5) ◽  
pp. 3771-3773 ◽  
Author(s):  
David L. Chambers ◽  
Arthur C. Hulse
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Serovars ◽  
Indiana County

ABSTRACT Herpetofaunal Salmonella enterica serovars have not been fully examined in any U.S. region. Thirty-three Salmonella serovars were isolated from 156 samples from 34 species, all within Indiana County, Pennsylvania. Results suggest that herpetofaunas could potentially pose a threat to humans. Further understanding of Salmonella in herpetofaunas may prevent future human cases.

Salmonella Sofia Differs from Other Poultry-Associated Salmonella Serovars with Respect to Cell Surface Hydrophobicity

2008 ◽  
Vol 71 (12) ◽  
pp. 2421-2428 ◽  
Author(s):  
T. W. R. CHIA ◽  
N. FEGAN ◽  
T. A. McMEEKIN ◽  
G. A. DYKES
Keyword(s):  
Zeta Potential ◽  
Cell Surface ◽  
Physicochemical Properties ◽  
Surface Charge ◽  
Hydrophobic Interaction ◽  
Salmonella Enterica ◽  
Food System ◽  
Cell Surface Hydrophobicity ◽  
Bacterial Attachment ◽  
Salmonella Serovars

Salmonella enterica is one of the most important foodborne pathogens. Salmonella enterica subsp. II 4,12:b:– (Salmonella Sofia) is commonly found in Australian poultry. It has been suggested that physicochemical properties such as surface charge and hydrophobicity may affect bacterial attachment to surfaces and their ability to persist in food systems. A possible link between hydrophobicity cell surface charge and persistence of Salmonella from the poultry system was examined. Hydrophobicity of Salmonella Sofia (n = 14), Salmonella Typhimurium (n = 6), Salmonella Infantis (n = 3), and Salmonella Virchow (n = 2) was assayed using hydrophobic interaction chromatography, bacterial adherence to hydrocarbons (BATH), using xylene or hexadecane, and the contact angle method (CAM). Cellular surface charge (CSC) of the isolates was determined using zeta potential measurements. The majority (12 of 14) of Salmonella Sofia isolates were found to be hydrophobic when assayed using BATH with xylene, except isolates S1635 and S1636, and the other serovars were found to be hydrophilic. Salmonella Sofia isolates were not significantly different (P > 0.05) from isolates of other serovars as measured by hydrophobic interaction, BATH with hexadecane, or the CAM. No significant differences (P > 0.05) in zeta potential measurements were observed between isolates. Principal component analysis using results from all four measures of hydrophobicity allowed clear differentiation between isolates of the serovar Salmonella Sofia (except S1635 and S1636) and those of other Salmonella serovars. Differences in physicochemical properties may be a contributing factor to the Salmonella Sofia serovar's ability to attach to surfaces and persist in a food system.

scholarly journals Complete Genome Sequences of 17 Canadian Isolates of Salmonella enterica subsp. enterica Serovar Heidelberg from Human, Animal, and Food Sources: TABLE 1

2016 ◽  
Vol 4 (5) ◽  
Author(s):  
Geneviève Labbé ◽  
Kim Ziebell ◽  
Sadjia Bekal ◽  
Kimberley A. Macdonald ◽  
E. Jane Parmley ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Resistance Genes ◽  
Salmonella Enterica ◽  
Complete Genome ◽  
Foodborne Illness ◽  
Food Sources ◽  
Genome Sequences ◽  
Human Animal

Salmonella enterica subsp. enterica serovar Heidelberg is a highly clonal serovar frequently associated with foodborne illness. To facilitate subtyping efforts, we report fully assembled genome sequences of 17 Canadian S . Heidelberg isolates including six pairs of epidemiologically related strains. The plasmid sequences of eight isolates contain several drug resistance genes.

scholarly journals Prevalence and Antimicrobial Resistance of Campylobacter spp. and Salmonella Serovars in Organic Chickens from Maryland Retail Stores

2005 ◽  
Vol 71 (7) ◽  
pp. 4108-4111 ◽  
Author(s):  
Shenghui Cui ◽  
Beilei Ge ◽  
Jie Zheng ◽  
Jianghong Meng
Keyword(s):  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Retail Stores ◽  
Serovar Typhimurium ◽  
Salmonella Serovars ◽  
Campylobacter Spp

ABSTRACT Retail organic (n = 198) and conventional (n = 61) chickens were analyzed. Most organic (76%) and conventional (74%) chickens were contaminated with campylobacters. Salmonellae were recovered from 61% of organic and 44% of conventional chickens. All Salmonella enterica serovar Typhimurium isolates from conventional chickens were resistant to five or more antimicrobials, whereas most S. enterica serovar Typhimurium isolates (79%) from organic chickens were susceptible to 17 antimicrobials tested.

scholarly journals Salmonella enterica: Survival, Colonization, and Virulence Differences among Serovars

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
A. Andino ◽  
I. Hanning
Keyword(s):  
Host Specificity ◽  
Salmonella Enterica ◽  
Foodborne Illness ◽  
Poultry Feed ◽  
Independent Factor ◽  
Expression Levels ◽  
Mitigation Methods

Data indicate that prevalence of specific serovars ofSalmonella entericain human foodborne illness is not correlated with their prevalence in feed. Given that feed is a suboptimal environment forS. enterica, it appears that survival in poultry feed may be an independent factor unrelated to virulence of specific serovars ofSalmonella. Additionally,S. entericaserovars appear to have different host specificity and the ability to cause disease in those hosts is also serovar dependent. These differences among the serovars may be related to gene presence or absence and expression levels of those genes. With a better understanding of serovar specificity, mitigation methods can be implemented to controlSalmonellaat preharvest and postharvest levels.

scholarly journals Isolation and Characterization of Salmonella Enterica Serovar Typhimurium Circulating Among Healthy Chickens of Bangladesh

2016 ◽  
Vol 4 (7) ◽  
pp. 519
Author(s):  
Md. Shafiullah Parvej ◽  
Marzia Rahman ◽  
Md. Forhad Uddin ◽  
KHM Nazmul Hussain Nazir ◽  
Md. Sayduzzaman Jowel ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Multidrug Resistant ◽  
Cloacal Swab ◽  
Specific Gene ◽  
Isolation And Characterization ◽  
Serovar Typhimurium ◽  
Salmonella Serovars ◽  
Layer Chickens ◽  
Apparently Healthy

Salmonella is considered as a global problem ranking first among food borne diseases. All motile Salmonella of poultry origin are zoonotic and readily transmit to human via meat and eggs but reports on non - typhoidal Salmonella serovars circulating in layer chickens is very limited in South-East Asian countries including Bangladesh. Salmonella serovars isolated from apparently healthy chickens were characterized in the present study. Of 170 samples (cloacal swab 150 and feed 20) collected from commercial layer farms, motile Salmonella was isolated 4% (6/150) and 50% (10/20) respectively by cultural, biochemical, motility test and by detection of hisJ gene. About 5% (8/170) samples possessed serovar-specific gene fimA, suggesting that isolates were Salmonella enterica serovar Typhimurium. Antimicrobial susceptibility testing demonstrated that the isolated serovars were multidrug resistant. Therefore apparently healthy layer chickens harbour and transmit S. Typhimurium to the environment, although little is alarming since it has zoonotic significance and the isolates were resistant to commonly used first line of antibiotic in Salmonella infection.

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