scholarly journals Outbreak of Salmonella enterica serovar Typhimurium in Switzerland, May – June 2008, implications for production and control of meat preparations

2008 ◽  
Vol 13 (44) ◽  
Author(s):  
H Schmid ◽  
H Hächler ◽  
R Stephan ◽  
A Baumgartner ◽  
K Boubaker
Keyword(s):  
Food Safety ◽  
Salmonella Typhimurium ◽  
Food Source ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Pfge Typing ◽  
Safety Regulations ◽  
Serovar Typhimurium ◽  
And Control ◽  
Minced Meat ◽  
Specific Food

An increased number of Salmonella Typhimurium cases were reported in Switzerland between May and June 2008. Investigations involved 72 cases. Results of PFGE typing identified several outbreak strains, the dominating one present in 43 of the 72 isolates. Strains affecting one third of the cases were also found in animal samples, in particular pork. However, no specific food source could be identified. Outbreaks described in this paper highlight the importance of food safety regulations such as those on minced meat and meat preparations issued by the European Commission and adopted by Switzerland into the national law.

Detection of Virulence Plasmid–Encoded Genes in Salmonella Typhimurium and Salmonella Kentucky Isolates Recovered from Commercially Processed Chicken Carcasses

2019 ◽  
Vol 82 (8) ◽  
pp. 1364-1368 ◽  
Author(s):  
RIZWANA TASMIN ◽  
PAUL A. GULIG ◽  
SALINA PARVEEN
Keyword(s):  
United States ◽  
Salmonella Typhimurium ◽  
Virulence Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
The United States ◽  
Clinical Isolates ◽  
Virulence Plasmid ◽  
Chicken Carcass ◽  
Serovar Typhimurium ◽  
Salmonella Virulence

ABSTRACT Salmonella enterica serovar Typhimurium is one of the leading causes of nontyphoidal gastroenteritis of humans in the United States. Commercially processed poultry carcasses are frequently contaminated with Salmonella serovar Kentucky in the United States. The aim of the study was to detect the Salmonella virulence plasmid containing the spv genes from Salmonella isolates recovered from commercially processed chicken carcasses. A total of 144 Salmonella isolates (Salmonella Typhimurium, n = 72 and Salmonella Kentucky, n = 72) were used for isolation of plasmids and detection of corresponding virulence genes (spvA, spvB, and spvC). Only four (5.5%) Salmonella Typhimurium isolates tested positive for all three virulence genes and hence were classified as possessing the virulence plasmid. All isolates of Salmonella Kentucky were negative for the virulence plasmid and genes. These results indicate that the virulence plasmid, which is very common among clinical isolates of Typhimurium and other Salmonella serovars (e.g., Enteritidis, Dublin, Choleraesuis, Gallinarum, Pullorum, and Abortusovis), may not be present in a significant portion of commercially processed chicken carcass isolates.

scholarly journals An outbreak of Salmonella Typhimurium infections in Denmark, Norway and Sweden, 2008

2009 ◽  
Vol 14 (10) ◽  
Author(s):  
T Bruun ◽  
G Sørensen ◽  
L P Forshell ◽  
T Jensen ◽  
K Nygård ◽  
...  
Keyword(s):  
Food Safety ◽  
Salmonella Typhimurium ◽  
Tandem Repeats ◽  
International Communication ◽  
Variable Number ◽  
Outbreak Strain ◽  
Cross Border ◽  
Trace Back ◽  
Outbreak Investigations ◽  
Minced Meat

In November-December 2008, Norway and Denmark independently identified outbreaks of Salmonella Typhimurium infections characterised in the multiple-locus variable number of tandem repeats analysis (MLVA) by a distinct profile. Outbreak investigations were initiated independently in the two countries. In Denmark, a total of 37 cases were identified, and multiple findings of the outbreak strain in pork and pigs within the same supply chain led to the identification of pork in various forms as the source. In Norway, ten cases were identified, and the outbreak investigation quickly indicated meat bought in Sweden as the probable source and the Swedish authorities were alerted. Investigations in Sweden identified four human cases and two isolates from minced meat with the distinct profile. Subsequent trace-back of the meat showed that it most likely originated from Denmark. Through international alert from Norway on 19 December, it became clear that the Danish and Norwegian outbreak strains were identical and, later on, that the source of the outbreaks in all three countries could be traced back to Danish pork. MLVA was instrumental in linking the outbreaks in the different countries and tracing the source. This outbreak illustrates that good international communication channels, early alerting mechanisms, inter-sectoral collaboration between public health and food safety authorities and harmonised molecular typing tools are important for effective identification and management of cross-border outbreaks. Differences in legal requirements for food safety in neighbouring countries may be a challenge in terms of communication with consumers in areas where cross-border shopping is common.

scholarly journals Excess of infections due to a multi-drug sensitive Salmonella enterica serotype Typhimurium in France in June 2008

2008 ◽  
Vol 13 (44) ◽  
Author(s):  
F Grandesso ◽  
N Jourdan-da Silva ◽  
S Le Hello ◽  
S Roussel ◽  
S Rasson ◽  
...  
Keyword(s):  
The Netherlands ◽  
Salmonella Typhimurium ◽  
Salmonella Enterica ◽  
Food Source ◽  
Pfge Profile ◽  
Typhimurium Strain ◽  
Specific Food

An unusually high number of cases of Salmonella Typhimurium was reported in France in June 2008. In the course of epidemiological investigations 112 cases were ascertained, of whom 75 were interviewed. Subtyping by PFGE and MLVA identified a strain named ""majority profile"". Subtyping results were available for 45 interviewed cases, 30 of whom (majority below 15 years of age) were found to be infected with the majority profile strain. Evidence suggested the occurrence of an outbreak due to a monoclonal S. Typhimurium strain with the single PFGE profile XTYM-50. Cases with identical PFGE profile were also detected in Switzerland but no link with outbreaks occurring in the same period in Denmark and in the Netherlands was found. Contamination of a product distributed nationally was suggested as the cause of the outbreak but investigations did not reveal any specific food source.

scholarly journals CpxR regulates the colistin susceptibility of Salmonella Typhimurium by a multitarget mechanism

2020 ◽  
Vol 75 (10) ◽  
pp. 2780-2786 ◽  
Author(s):  
Ya-Jun Zhai ◽  
Hua-Run Sun ◽  
Xing-Wei Luo ◽  
Jian-Hua Liu ◽  
Yu-Shan Pan ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Target Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Efflux Pump ◽  
Colistin Resistance ◽  
Mobility Shift ◽  
Serovar Typhimurium ◽  
Electrophoretic Mobility Shift Assays ◽  
First Time ◽  
Signalling Systems

Abstract Background The two-component signalling systems PmrAB and PhoPQ of Salmonella have been extensively studied with regard to colistin resistance. We previously showed that overexpressed CpxR could significantly increase the colistin susceptibility (16-fold compared with the WT strain) of Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) through PmrAB and PhoPQ. Objectives To identify the potential target genes of CpxR in PmrAB- and PhoPQ-related signalling pathways. Methods His6-CpxR was prokaryotically expressed and purified by Ni-NTA resin affinity chromatography. β-Galactosidase activity assays were conducted to investigate whether CpxR could regulate the promoters of colistin resistance-related genes (CRRGs). Electrophoretic mobility shift assays (EMSAs) were used to further detect His6-CpxR complexes with promoters of CRRGs. Results We demonstrated for the first time (to the best of our knowledge) that CpxR and the AcrAB–TolC efflux pump have reciprocal effects on CRRG transcription. Additionally, CpxR could regulate the colistin susceptibility of Salmonella Typhimurium by binding directly to the promoters of phoPQ, pmrC, pmrH and pmrD at the CpxR box-like sequences or indirectly through other regulators including pmrAB and mgrB. Conclusions CpxR could regulate the colistin susceptibility of Salmonella Typhimurium by a multitarget mechanism.

Fate of Staphylococcus aureus, Salmonella enterica Serovar Typhimurium, and Vibrio vulnificus in Raw Oysters Treated with Chitosan

2006 ◽  
Vol 69 (7) ◽  
pp. 1600-1604 ◽  
Author(s):  
PALLAVI CHHABRA ◽  
YAO-WEN HUANG ◽  
JOSEPH F. FRANK ◽  
REVIS CHMIELEWSKI ◽  
KEITH GATES
Keyword(s):  
Staphylococcus Aureus ◽  
Hydrochloric Acid ◽  
Salmonella Typhimurium ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Vibrio Vulnificus ◽  
Storage Period ◽  
Major Effect ◽  
Chitosan Concentration ◽  
Serovar Typhimurium

The fate of Staphylococcus aureus, Salmonella enterica serovar Typhimurium, and Vibrio vulnificus in oysters treated with chitosan was investigated. Three concentrations (0.5, 1.0, and 2.0%) of chitosan in 0.5% hydrochloric acid were prepared and coated onto raw oysters, which were then stored at 4°C for 12 days. Untreated oysters and oysters coated with 0.5% hydrochloric acid without chitosan were used as controls. S. aureus cells were most sensitive to 2.0% chitosan followed by 0.5 and 1.0%. In general, chitosan treatment of oysters produced a decline in the population of S. aureus by 1 to 4 log CFU/ml compared with the untreated control. Chitosan treatment had no influence on the reduction of Salmonella Typhimurium over the 12-day storage period; inhibition of Salmonella Typhimurium growth was similar in both the control samples and the chitosan-treated samples. However, time of storage had a major effect on the survival of Salmonella Typhimurium on oysters. Neither time nor chitosan concentration had a significant effect on the growth of V. vulnificus during storage. All treatments were similar in inhibiting V. vulnificus growth.

MDR Salmonella enterica serovar Typhimurium ST34 carrying mcr-1 isolated from cases of bloodstream and intestinal infection in children in China

2019 ◽  
Vol 75 (1) ◽  
pp. 92-95 ◽  
Author(s):  
Qixia Luo ◽  
Fen Wan ◽  
Xiao Yu ◽  
Beiwen Zheng ◽  
Yunbo Chen ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Ecological Niches ◽  
Salmonella Infection ◽  
Serovar Typhimurium ◽  
Multiple Resistance Genes ◽  
Tn7 Transposition

Abstract Objectives Children are vulnerable to Salmonella infection due to their immature immune system. Cases of infection with mcr-1-harbouring Salmonella in child inpatients have not been reported in China before. Methods Salmonella isolates from gastroenteritis and bacteraemia were screened using primers targeting mcr-1. Complete genome sequences of mcr-1-harbouring isolates were determined using the PacBio RS II platform. The transferability of mcr-1-harbouring plasmids was verified by conjugation. Results We investigated two mcr-1-carrying polymyxin-resistant Salmonella enterica serovar Typhimurium ST34 isolates, S61394 and S44712, from bloodstream and intestinal Salmonella infection of two child inpatients, respectively. Both isolates were non-susceptible to commonly used antibiotics for children that compromised the success of clinical treatment and infection control. The mcr-1-harbouring plasmids pLS61394-MCR and pLS44712-MCR (from S61394 and S44712, respectively) were both conjugative pHNSHP45-2-like IncHI2-type epidemic plasmids carrying multiple resistance genes. Compared with pHNSHP45-2, a ∼33 kb insertion region encoding Tn7 transposition protein and heavy metal resistance proteins was identified in pLS61394-MCR, which might enhance adaptation of bacteria carrying this plasmid to various ecological niches. The phylogenetic tree of worldwide mcr-harbouring Salmonella indicated a host preference of mcr and a worldwide and cross-sectoral prevalence of the mcr-positive Salmonella ST34 clone. Conclusions To our knowledge, for the first time we report completed whole genomes of mcr-1-positive MDR Salmonella Typhimurium ST34 isolated from infected children in China, suggesting that improved surveillance is imperative for tackling the dissemination of mcr-harbouring MDR Salmonella Typhimurium ST34.

Effectiveness of Sanitizing Products on Controlling Selected Pathogen Surrogates on Retail Deli Slicers

2015 ◽  
Vol 78 (4) ◽  
pp. 707-715 ◽  
Author(s):  
MICHAEL C. YEATER ◽  
KATIE R. KIRSCH ◽  
T. MATTHEW TAYLOR ◽  
JEFF MITCHELL ◽  
WESLEY N. OSBURN
Keyword(s):  
High Risk ◽  
Salmonella Typhimurium ◽  
Ammonium Chloride ◽  
Quaternary Ammonium ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Bacterial Attachment ◽  
Listeria Innocua ◽  
Serovar Typhimurium ◽  
Treatment Interaction ◽  
Quaternary Ammonium Chloride

The objectives of this study were (i) to assess the efficacy of quaternary ammonium chloride–based wet foam (WF) and dry foam (DF) sanitizer systems (600 ppm) for reducing Listeria innocua (a nonpathogenic surrogate of Listeria monocytogenes) or a 100.0 μg/ml rifampin-resistant Salmonella Typhimurium LT2 (a nonpathogenic surrogate of Salmonella enterica serovar Typhimurium) on niche and transfer point areas of an unwashed retail deli slicer as compared with traditional chlorine (Cl−) treatment (200 ppm) and (ii) to compare sanitizer surface contact times (10 and 15 min) for pathogen surrogate control. Turkey frankfurter slurries inoculated with L. innocua or Salmonella Typhimurium were used to inoculate seven high-risk sites on a commercial slicer. After 30 min of bacterial attachment, slicers were dry wiped to remove excess food matter, followed by a randomly assigned sanitizer treatment. Surviving pathogen surrogate cells were enumerated on modified Oxford's agar not containing antimicrobic supplement (L. innocua) or on tryptic soy agar supplemented with 100 μg/ml rifampin (Salmonella Typhimurium LT2). Replicate-specific L. innocua and Salmonella Typhimurium reductions were calculated as log CFU per square centimeter of control minus log CFU per square centimeter of enumerated survivors for each site. For both organisms, all sanitizer treatments differed from each other, with Cl− producing the least reduction and WF the greatest reduction. A significant (P < 0.05) site-by-treatment interaction was observed. The results of the study indicate that quaternary ammonium chloride sanitizers (600 ppm) applied by both WF and DF were more effective at reducing L. innocua and Salmonella Typhimurium than a traditional Cl sanitizer (200 ppm) on unwashed slicer surfaces.

Characterization of Nalidixic Acid–Resistant and Fluoroquinolone-Reduced Susceptible Salmonella Typhimurium in Swine

2011 ◽  
Vol 74 (4) ◽  
pp. 610-615 ◽  
Author(s):  
K. E. LEE ◽  
J. H. JUNG ◽  
B. Y. JUNG ◽  
Y. H. PARK ◽  
Y. H. LEE
Keyword(s):  
Salmonella Typhimurium ◽  
Nalidixic Acid ◽  
Antimicrobial Agents ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Multidrug Resistant ◽  
Quinolone Resistance ◽  
Specific Primers ◽  
Serovar Typhimurium ◽  
Clonal Spread

From 2001 to 2008, a total of 27 isolates of Salmonella enterica serovar Typhimurium were obtained from 930 swine. All 27 isolates were resistant to streptomycin and tetracycline. Seventeen isolates were multidrug resistant to more than three antimicrobial agents. Seven of these multidrug-resistant isolates were pentaresistant to ampicillin, chloramphenicol, streptomycin, tetracycline, and nalidixic acid. Among 27 isolates, 14 isolates (51.8%) were nalidixic acid resistant (MIC, ≥128 μg/ml) and had reduced susceptibility to various quinolones (MIC, 0.125 to 2 μg/ml). When quinolone resistance–determining regions in the gyrA and gyrB genes of these isolates were sequenced, 13 isolates had Asp87→Tyr mutations and 1 isolate had Asp87→Gly mutation in the quinolone resistance–determining region of gyrA, whereas no mutation was found in gyrB. Genes for qnrA, qnrB, and qnrS were not detected by PCR with specific primers. Pulsed-field gel electrophoresis of genomic DNA digested with XbaI showed two patterns suggesting a clonal spread of Salmonella Typhimurium in swine in Korea.

scholarly journals Mixed Biofilm Formation by Shiga Toxin–Producing Escherichia coli and Salmonella enterica Serovar Typhimurium Enhanced Bacterial Resistance to Sanitization due to Extracellular Polymeric Substances†

2013 ◽  
Vol 76 (9) ◽  
pp. 1513-1522 ◽  
Author(s):  
RONG WANG ◽  
NORASAK KALCHAYANAND ◽  
JOHN W. SCHMIDT ◽  
DAYNA M. HARHAY
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Foodborne Pathogens ◽  
Shiga Toxin ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Bacterial Resistance ◽  
Salmonella Enterica Serovar Typhimurium ◽  
E Coli ◽  
Serovar Typhimurium

Shiga toxin–producing Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium are important foodborne pathogens capable of forming single-species biofilms or coexisting in multispecies biofilm communities. Bacterial biofilm cells are usually more resistant to sanitization than their planktonic counterparts, so these foodborne pathogens in biofilms pose a serious food safety concern. We investigated how the coexistence of E. coli O157:H7 and Salmonella Typhimurium strains would affect bacterial planktonic growth competition and mixed biofilm composition. Furthermore, we also investigated how mixed biofilm formation would affect bacterial resistance to common sanitizers. Salmonella Typhimurium strains were able to outcompete E. coli strains in the planktonic growth phase; however, mixed biofilm development was highly dependent upon companion strain properties in terms of the expression of bacterial extracellular polymeric substances (EPS), including curli fimbriae and exopolysaccharide cellulose. The EPS-producing strains with higher biofilm-forming abilities were able to establish themselves in mixed biofilms more efficiently. In comparison to single-strain biofilms, Salmonella or E. coli strains with negative EPS expression obtained significantly enhanced resistance to sanitization by forming mixed biofilms with an EPS-producing companion strain of the other species. These observations indicate that the bacterial EPS components not only enhance the sanitizer resistance of the EPS-producing strains but also render protections to their companion strains, regardless of species, in mixed biofilms. Our study highlights the potential risk of cross-contamination by multispecies biofilms in food safety and the need for increased attention to proper sanitization practices in food processing facilities.

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