Structure of the French farm-to-table surveillance system for Salmonella

The French surveillance system for Salmonella is based on a national system which can be traced back to 1947 for human cases and to the late 1980s for the main animal reservoirs. This system has evolved with regard to both European regulations and changes in the observed prevalence of Salmonella. European regulations establish a solid foundation on which to build an active harmonised surveillance system at the production level and for integrating data from the whole food chain. There are also passive surveillance networks in the agri-food and veterinary sectors and these allow complementary information to be obtained from other sectors or sources. The main strengths and weaknesses of these systems are described and a comparison of the different approaches is presented using a grid analysis. The results show that passive systems are very useful for detecting emerging or unusual events and for early warning of outbreaks. They also produce time series of cases or can determine the number of strains that should be used to assess the impact of interventions. Active surveillance data, due to their representativeness and reliability, are key elements in the application of risk analysis tools such as quantitative risk assessment or attribution. Thus, although data is collected and analysed by various organisations, these organisations all collaborate at a national level. Furthermore, their implication in European and international projects is effective and the main objectives of a surveillance system can be met

Characterization of soot particles in the plumes of over-ventilated diffusion flames

International audienceno abstrac

Novel insertion sequence- and transposon-mediated genetic rearrangements in genomic island SGI1 of Salmonella enterica serovar Kentucky36800

Salmonella genomic island 1 (SGI1) is an integrative mobilizable element that harbors a multidrug resistance (MDR) gene cluster. Since its identification in epidemic Salmonella enterica serovar Typhimurium DT104 strains, variant SGI1 MDR gene clusters conferring different MDR phenotypes have been identified in several S. enterica serovars and classified as SGI1-A to -O. A study was undertaken to characterize SGI1 from serovar Kentucky strains isolated from travelers returning from Africa. Several strains tested were found to contain the partially characterized variant SGI1-K, recently described in a serovar Kentucky strain isolated in Australia. This variant contained only one cassette array, aac(3)-Id-aadA7, and an adjacent mercury resistance module. Here, the uncharacterized part of SGI1-K was sequenced. Downstream of the mer module similar to that found in Tn21, a mosaic genetic structure was found, comprising (i) part of Tn1721 containing the tetracycline resistance genes tetR and tet(A); (ii) part of Tn5393 containing the streptomycin resistance genes strAB, IS1133, and a truncated tnpR gene; and (iii) a Tn3-like region containing the tnpR gene and the beta-lactamase bla(TEM-1) gene flanked by two IS26 elements in opposite orientations. The rightmost IS26 element was shown to be inserted into the S044 open reading frame of the SGI1 backbone. This variant MDR region was named SGI1-K1 according to the previously described variant SGI1-K. Other SGI1-K MDR regions due to different IS26 locations, inversion, and partial deletions were characterized and named SGI1-K2 to -K5. Two new SGI1 variants named SGI1-P1 and -P2 contained only the Tn3-like region comprising the beta-lactamase bla(TEM-1) gene flanked by the two IS26 elements inserted into the SGI1 backbone. Three other new variants harbored only one IS26 element inserted in place of the MDR region of SGI1 and were named SGI1-Q1 to -Q3. Thus, in serovar Kentucky, the SGI1 MDR region undergoes recombinational and insertional events of transposon and insertion sequences, resulting in a higher diversity of MDR gene clusters than previously reported and consequently a higher diversity of MDR phenotypes</p

Epidemiological and genetic features associated with the international spread of multi-drug resistant <em>Salmonella</em> Kentucky ST198

National audienc

Effect of ramR mutations on efflux genes expression and on fluoroquinolone susceptibility in <em>Salmonella enterica</em> serotype Kentucky ST198

National audienceBackground. Efflux is a mechanism that has been previously reported to increase fluoroquinolone (FQ) resistance levels when it is upregulated in clinical isolates of Salmonella enterica mainly of serotype Typhimurium (1). In this study efflux related genes were investigated in the emerging FQ-resistant epidemic S. enterica serotype Kentucky ST198 clone (2) for the presence of mutations in their regulatory genes, and for their expression levels. Methods. Among a representative panel of thirty serotype Kentucky strains from Egypt or east Africa with decreased FQ susceptibility, three strains overproducing the AcrAB-TolC efflux system were detected and studied (3). Two FQ-resistant strains with substitutions in QRDR and with basal expression level of AcrABTolC and the susceptible reference strain 98K were used as control. Genetic relatedness was determined by XbaI-pulsed field gel electrophoresis and multilocus sequence typing. Presence of mutations in the ramRA, soxRS, marOR loci and acrR, acrS genes were assessed by sequencing. The six strains and their wild-type ramR gene complemented derivatives were analysed by (i) qRT-PCR for gene expression of regulatory and efflux genes and by (ii) MIC determinations of quinolones, FQ and florfenicol as other substrate of AcrAB-TolC. Results. All serotype Kentucky strains studied were of sequence type X1-ST198, excepted the 98K strain which was X4-ST198. Among the thirty S. Kentucky strains, three overproduce AcrAB-TolC (3). All three strains presented different mutations in the ramR gene in comparison to the reference strain 98K. The three detected mutations (deletion of 91 bp, insertion of 1 bp or 4 bp) resulted in frame shift of the ramR gene. All other efflux regulatory genes were not mutated. As confirmed by complementation with a wild-type ramR gene, all three mutations were responsible for increased expression of ramA and acrAB. Increased expression of tolC and acrEF genes was observed in 2 out of the 3 strains. All three mutations were shown to increase two-fold the MICs of FQ and florfenicol in comparison to the ramR complemented derivatives and the reference strain. The two strains with a basal expression level of AcrAB-TolC presented any mutation in sequenced genes. The only strain presenting 3 substitutions in QRDR associated with 1 mutation in ramR upregulating AcrAB-TolC leaded to the higher level FQ resistance Conclusion. Various novel ramR mutations, responsible for increased efflux, were detected in the emerging epidemic serotype Kentucky ST198 clone. As previously reported in other FQ-resistant strains of serotypes Typhimurium or Schwarzengrund, ramR mutations seem to be sporadic (10 % in this study) and contribute only to a little extent to the decreased FQ susceptibilit

Nationwide pseudo-outbreak of Salmonella enterica ssp. diarizonae, France

International audienceTo investigate an increased incidence of human cultures growing Salmonella enterica ssp. diarizonae serotype 61:k:1,5,7 in France in 2008, we reviewed medical records of case patients and identified the material used during invasive procedures and for bacterial culture. Trace-back investigations incriminated culture media containing contaminated sheep blood agar

Epidemiological and genetic features associated with the international spread of multi-drug resistant Salmonella Kentucky ST198

National audienc

Salmonella infections associated with reptiles: the current situation in Europe36794

Salmonella infections are caused by consumption of contaminated food, person-to-person transmission, waterborne transmission and numerous environmental and animal exposures. Specifically, reptiles and other cold blooded animals (often referred to as &quot;exotic pets&quot;) can act as reservoirs of Salmonella, and cases of infection have been associated with direct or indirect contact with these animals. Approximately 1.4 million human cases of Salmonella infection occur each year in the United States and it has been estimated that 74,000 are a result of exposure to reptiles and amphibians. Regular case reports of reptile-associated salmonellosis in the US are available for the period 1994-2002. Cases of Salmonella infection attributed to direct or indirect contact with reptiles or other exotic pets have been described in a number of European countries, too but a more comprehensive overview of the magnitude of this problem in Europe is lacking. In total, 160,649 human cases of salmonellosis were reported in 2006 in the then 25 European Union Member States, Bulgaria, Romania, Iceland, Liechtenstein and Norway</p

Community Incidence of Campylobacteriosis and Nontyphoidal Salmonellosis, France, 2008-2013.

&lt;p&gt;Community incidence estimates are necessary to assess the burden and impact of infections on health and to set priorities for surveillance, research, prevention, and control strategies. The current study was performed to estimate the community incidence of campylobacteriosis and nontyphoidal salmonellosis in France from the number of laboratory-confirmed cases reported to the national reference center (NRC). The probabilities of a case in the community visiting a doctor, having a stool sample requested, having a positive laboratory test, and having the case reported to the NRC were estimated using data of national surveillance systems, national hospitalization and health insurance databases, and specific surveys informing about these parameters. Credible intervals (CrI) were calculated using Monte Carlo simulation. In addition, we estimated the number of hospitalizations for both infections in France. The annual community incidence rate in France is estimated at 842 cases per 100,000 (90%CrI 525-1690) for campylobacteriosis and 307 cases per 100,000 (90%CrI 173-611) for salmonellosis. The annual number of hospitalizations is estimated at 5182 for campylobacteriosis and 4305 for salmonellosis. The multiplication factors between cases ascertained by the surveillance system and cases in the community were 115 for campylobacteriosis and 20 for salmonellosis. They are consistent with estimates reported in other countries, indicating a high community incidence of campylobacteriosis and salmonellosis in France.&lt;/p&gt;</p

Reptiles in Guadeloupe (French West Indies) are a reservoir of major human Salmonella enterica serovars

International audienceA retrospective study was conducted to identify the risk factors associated withSalmonella enterica bacteremia in infants and children in Guadeloupe. The 171 patients with S.S. enterica infection seen between 2010 and 2014 included 155 (90.6%) with acutegastroenteritis, of whom 42 (27.1%) had concomitant bacteremia, and 16 (9.4%) with primarybacteremia. The most common Salmonella serovars were Panama (N = 57, 33.3% of isolates)and Arechavaleta (N = 28, 16.4%). Infection with the previous serovars was significantlyassociated with bacteremia in a multivariate analysis. A delay between onset of symptoms andhospital admission > 5 days (P = 0.01), vomiting (P = 0.001), and increased respiratory rate (P= 0.001) contributed independently to bacteremia in the multivariate analysis. Thus, if nontyphoidalinfection is suspected, blood should be cultured and antibiotic treatment initiated in allall patients who meet these criteria