title: Phenotypic and Molecular Characterization of Salmonella 1,4,[5],12:i:- R-Type ASSuT Isolates from Humans, Animals, and Environment in Portugal, 2006-2011.
abstract: The increase in prevalence of Salmonella 1,4,[5],12:i:- related infections over the last few years has been considered a public health issue in many European countries, especially as this serovar may be associated with tetraresistance to ampicillin, streptomycin, sulfonamides, and tetracyclines (R-type ASSuT). Salmonella 1,4,[5],12:i:- isolates (n = 187) obtained by the Portuguese National Laboratory from different sources, including human clinical cases (n = 170), veterinary (n = 10), environmental (n = 6), and food samples (n = 1), were collected from 15 districts between 2006 and 2011. All isolates were serotyped using the slide agglutination method and results were confirmed by multiplex PCR for the monophasic variant. From the confirmed Salmonella 1,4,[5],12:i:-, R-type ASSuT isolates were selected by disc diffusion and minimal inhibitory concentration (MIC) determination for further characterization by pulsed-field gel electrophoresis restriction with XbaI, virulence genes determination by PCR, additional antimicrobial resistance profiling by disc diffusion, and epidemiological distribution evaluation. Out of the 187 serotyped isolates, 133 were confirmed as Salmonella 1,4,[5],12:i:- with a R-type ASSuT occurrence of 61.7%. Distribution among Portuguese districts showed a higher percentage of reported cases in coastal areas, in particular, in Porto (24.8%), Setúbal (13.5%), and Aveiro (12.8%), probably due to the higher population density. Clonality analysis revealed a high diversity of pulsotypes with the majority of human salmonellosis cases being attributed to sporadic events. All isolates harbored 14 out of the 18 virulence genes evaluated and 87.8% of the isolates showed all the resistance genes frequently associated with the European clone, blaTEM+sul2+straA-straB+tetB+. This study shows that Salmonella 1,4,[5],12:i:- resistant isolates are widely distributed in Portugal. This may be related to a selective advantage offered by R-type ASSuT profile, the presence of multiple virulent features, including the ability to form biofilms, which along with a high diversity of pulsotypes may be responsible for the dissemination through the country.
authors: 1 CIISA/Faculty of Veterinary Medicine, University of Lisbon , Lisbon, Portugal .
authors: Rui
authors: R
authors: Seixas
authors: 1 CIISA/Faculty of Veterinary Medicine, University of Lisbon , Lisbon, Portugal .
authors: Tânia Raquel
authors: TR
authors: Santos
authors: 2 National Reference Laboratory of Gastrointestinal Infections, National Health Institute Doutor Ricardo Jorge , Lisbon, Portugal .
authors: Jorge
authors: J
authors: Machado
authors: 1 CIISA/Faculty of Veterinary Medicine, University of Lisbon , Lisbon, Portugal .
authors: Luís
authors: L
authors: Tavares
authors: 1 CIISA/Faculty of Veterinary Medicine, University of Lisbon , Lisbon, Portugal .
authors: Fernando
authors: F
authors: Bernardo
authors: 1 CIISA/Faculty of Veterinary Medicine, University of Lisbon , Lisbon, Portugal .
authors: Teresa
authors: T
authors: Semedo-Lemsaddek
authors: 1 CIISA/Faculty of Veterinary Medicine, University of Lisbon , Lisbon, Portugal .
authors: Manuela
authors: M
authors: Oliveira
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development; D024901:Drug Resistance, Multiple, Bacterial; D005243:Feces / Q000382:microbiology; D005506:Food Contamination; D005516:Food Microbiology; D006801:Humans; D015994:Incidence; D008198:Lymph Nodes / Q000382:microbiology; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D058889:Molecular Typing / Q000662:veterinary; D011159:Population Surveillance; D011174:Portugal / Q000453:epidemiology; D012475:Salmonella / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification* / Q000502:physiology; D012480:Salmonella Infections / Q000453:epidemiology / Q000382:microbiology*; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D062211:Spatio-Temporal Analysis; D034421:Sus scrofa; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism; D014871:Water Microbiology; D060753:Water Quality
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D037521:Virulence Factors
keywords: Portugal; R-type ASSuT; Salmonella 1,4,[5],12:i:-; virulence factors