1
|
Vázquez X, Fernández J, Heinisch JJ, Rodicio R, Rodicio MR. Insights into the Evolution of IncR Plasmids Found in the Southern European Clone of the Monophasic Variant of Salmonella enterica Serovar Typhimurium. Antibiotics (Basel) 2024; 13:314. [PMID: 38666990 PMCID: PMC11047700 DOI: 10.3390/antibiotics13040314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 03/22/2024] [Accepted: 03/25/2024] [Indexed: 04/29/2024] Open
Abstract
Salmonella enterica subspecies enterica serovar 4,[5],12:i:- is a monophasic variant of S. Typhimurium which has emerged as a world-wide distributed pathogen in the last decades. Several clones have been identified within this variant, the European clone, the Spanish clone, the Southern European clone and the U.S./American clone. The present study focused on isolates of the Southern European clone that were obtained from clinical samples at Spanish hospitals. The selected isolates were multidrug resistant, with most resistance genes residing on IncR plasmids that also carried virulence genes. These plasmids had a mosaic structure, comprising a highly reduced IncR backbone, which has acquired a large amount of exogenous DNA mostly derived from pSLT and IncI1-I(alfa) plasmids. Although composed of approximately the same elements, the investigated plasmids displayed a high diversity, consistent with active evolution driven by a wealth of mobile genetic elements. They comprise multiple intact or truncated insertion sequences, transposons, pseudo-compound transposons and integrons. Particularly relevant was the role of IS26 (with six to nine copies per plasmid) in generating insertions, deletions and inversions, with many of the rearrangements uncovered by tracking the patterns of eight bp target site duplications. Most of the resistance genes detected in the analyzed isolates have been previously associated with the Southern European clone. However, erm(B), lnu(G) and blaTEM-1B are novel, with the last two carried by a second resistance plasmid found in one of the IncR-positive isolates. Thus, evolution of resistance in the Southern European clone is not only mediated by diversification of the IncR plasmids, but also through acquisition of additional plasmids. All isolates investigated in the present study have the large deletion affecting the fljBA region previously found to justify the monophasic phenotype in the Southern European and U.S./American clones. An SNP-based phylogenetic analysis revealed the close relationship amongst our isolates, and support that those sharing the large fljBA deletion could be more heterogeneous than previously anticipated.
Collapse
Affiliation(s)
- Xenia Vázquez
- Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo (UO), 33006 Oviedo, Spain; (X.V.); (J.F.)
- Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain;
| | - Javier Fernández
- Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo (UO), 33006 Oviedo, Spain; (X.V.); (J.F.)
- Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain;
- Servicio de Microbiología, Hospital Universitario Central de Asturias (HUCA), 33011 Oviedo, Spain
- Centro de Investigación Biomédica en Red-Enfermedades Respiratorias, 30627 Madrid, Spain
- Research & Innovation, Artificial Intelligence and Statistical Department, Pragmatech AI Solutions, 33001 Oviedo, Spain
| | - Jürgen J. Heinisch
- Department of Genetics, Faculty of Biology and Chemistry, University of Osnabrück, Barbarastrasse 11, D-49076 Osnabrück, Germany;
| | - Rosaura Rodicio
- Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain;
- Departamento de Bioquímica y Biología Molecular, Universidad de Oviedo (UO), 33006 Oviedo, Spain
| | - M. Rosario Rodicio
- Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo (UO), 33006 Oviedo, Spain; (X.V.); (J.F.)
- Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain;
| |
Collapse
|
2
|
Wang Z, Gu D, Hong Y, Hu Y, Gu J, Tang Y, Zhou X, Zhang Y, Jiao X, Li Q. Microevolution of Salmonella 4,[5],12:i:- derived from Salmonella enterica serovar Typhimurium through complicated transpositions. Cell Rep 2023; 42:113227. [PMID: 37837619 DOI: 10.1016/j.celrep.2023.113227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 08/28/2023] [Accepted: 09/21/2023] [Indexed: 10/16/2023] Open
Abstract
Salmonella enterica subsp. enterica serovar 4,[5],12:i:- (Salmonella 4,[5],12:i:-), derived from S. Typhimurium, has become the dominant serotype causing human salmonellosis. In this study, we define the genetic mechanism of the generation of Salmonella 4,[5],12:i:- from S. Typhimurium through complicated transpositions and demonstrate that Salmonella 4,[5],12:i:- displays more efficient colonization and survival abilities in mice than its parent S. Typhimurium strain. We identified intermediate strains carrying both resistance regions (RRs) and the fljAB operon for the generation of Salmonella 4,[5],12:i:-. The insertion of RR3 into the chromosomal hin-iroB site of S. Typhimurium produced RR3-S. Typhimurium as a primary intermediate. Salmonella 4,[5],12:i:- was then produced by replacing the fljAB operon and/or its flanking sequences through intramolecular transpositions mediated by IS26 and/or IS1R elements in RR3-S. Typhimurium, which was further confirmed both in vitro and in vivo. Overall, we demonstrate the molecular mechanism underlying the origin, generation, and advantage of RRs-Salmonella 4,[5],12:i:- from S. Typhimurium.
Collapse
Affiliation(s)
- Zhenyu Wang
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Jiangsu Key Lab of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-product Safety, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China
| | - Dan Gu
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Jiangsu Key Lab of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-product Safety, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China
| | - Yaming Hong
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Jiangsu Key Lab of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-product Safety, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China
| | - Yachen Hu
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Jiangsu Key Lab of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-product Safety, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China
| | - Jiaojie Gu
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Jiangsu Key Lab of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-product Safety, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China
| | - Yuanyue Tang
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Jiangsu Key Lab of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-product Safety, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China
| | - Xiaohui Zhou
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT 06269, USA; School of Public Health and Emergency Management, Southern University of Science and Technology, 1088 Xueyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Yunzeng Zhang
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Jiangsu Key Lab of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-product Safety, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China.
| | - Xinan Jiao
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Jiangsu Key Lab of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-product Safety, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China.
| | - Qiuchun Li
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Jiangsu Key Lab of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China; Joint International Research Laboratory of Agriculture and Agri-product Safety, Yangzhou University, 48 Wenhui East Road, Yangzhou 225000, Jiangsu, China.
| |
Collapse
|
3
|
Vázquez X, García-Fierro R, Fernández J, Bances M, Herrero-Fresno A, Olsen JE, Rodicio R, Ladero V, García V, Rodicio MR. Incidence and Genomic Background of Antibiotic Resistance in Food-Borne and Clinical Isolates of Salmonella enterica Serovar Derby from Spain. Antibiotics (Basel) 2023; 12:1204. [PMID: 37508300 PMCID: PMC10376468 DOI: 10.3390/antibiotics12071204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 07/15/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023] Open
Abstract
Salmonella enterica serovar Derby (S. Derby) ranks fifth among nontyphoidal Salmonella serovars causing human infections in the European Union. S. Derby isolates (36) collected between 2006 and 2018 in a Spanish region (Asturias) from human clinical samples (20) as well as from pig carcasses, pork- or pork and beef-derived products, or wild boar (16) were phenotypically characterized with regard to resistance, and 22 (12 derived from humans and 10 from food-related samples) were also subjected to whole genome sequence analysis. The sequenced isolates belonged to ST40, a common S. Derby sequence type, and were positive for SPI-23, a Salmonella pathogenicity island involved in adherence and invasion of the porcine jejune enterocytes. Isolates were either susceptible (30.6%), or resistant to one or more of the 19 antibiotics tested for (69.4%). Resistances to tetracycline [tet(A), tet(B) and tet(C)], streptomycin (aadA2), sulfonamides (sul1), nalidixic acid [gyrA (Asp87 to Asn)] and ampicillin (blaTEM-1-like) were detected, with frequencies ranging from 8.3% to 66.7%, and were higher in clinical than in food-borne isolates. The fosA7.3 gene was present in all sequenced isolates. The most common phenotype was that conferred by the tet(A), aadA2 and sul1 genes, located within identical or closely related variants of Salmonella Genomic Island 1 (SGI1), where mercury resistance genes were also present. Diverse IncI1-I(α) plasmids belonging to distinct STs provided antibiotic [blaTEM-1, tet(A) and/or tet(B)] and heavy metal resistance genes (copper and silver), while small pSC101-like plasmids carried tet(C). Regardless of their location, most resistance genes were associated with genetic elements involved in DNA mobility, including a class one integron, multiple insertion sequences and several intact or truncated transposons. By phylogenetic analysis, the isolates were distributed into two distinct clades, both including food-borne and clinical isolates. One of these clades included all SGI1-like positive isolates, which were found in both kinds of samples throughout the entire period of study. Although the frequency of S. Derby in Asturias was very low (0.5% and 3.1% of the total clinical and food isolates of S. enterica recovered along the period of study), it still represents a burden to human health linked to transmission across the food chain. The information generated in the present study can support further epidemiological surveillance aimed to control this zoonotic pathogen.
Collapse
Affiliation(s)
- Xenia Vázquez
- Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo (UO), 33006 Oviedo, Spain
- Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Instituto de Productos Lácteos de Asturias (IPLA), Consejo Superior de Investigaciones Científicas (CSIC), 33300 Villaviciosa, Spain
| | - Raquel García-Fierro
- Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo (UO), 33006 Oviedo, Spain
| | - Javier Fernández
- Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Servicio de Microbiología, Hospital Universitario Central de Asturias (HUCA), 33011 Oviedo, Spain
- Centro de Investigación Biomédica en Red-Enfermedades Respiratorias, 30627 Madrid, Spain
- Research & Innovation, Artificial Intelligence and Statistical Department, Pragmatech AI Solutions, 33001 Oviedo, Spain
| | - Margarita Bances
- Laboratorio de Salud Pública, Dirección General de Salud Pública, Consejería de Salud del Principado de Asturias, 33011 Oviedo, Spain
| | - Ana Herrero-Fresno
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark
| | - John E Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark
| | - Rosaura Rodicio
- Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Departamento de Bioquímica y Biología Molecular, Universidad de Oviedo (UO), 33006 Oviedo, Spain
| | - Víctor Ladero
- Instituto de Productos Lácteos de Asturias (IPLA), Consejo Superior de Investigaciones Científicas (CSIC), 33300 Villaviciosa, Spain
- Grupo de Microbiología Molecular, Instituto de Investigación Sanitaria del Principado de Asturias (IAPA), 33011 Oviedo, Spain
| | - Vanesa García
- Laboratorio de Referencia de Escherichia coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Campus Terra, Universidade de Santiago de Compostela, 27002 Lugo, Spain
- Instituto de Investigación Sanitaria de Santiago de Compostela, 15706 Santiago de Compostela, Spain
| | - M Rosario Rodicio
- Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo (UO), 33006 Oviedo, Spain
- Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| |
Collapse
|
4
|
Zhang F, Ye X, Yin Z, Hu M, Wang B, Liu W, Li B, Ren H, Jin Y, Yue J. Comparative genomics reveals new insights into the evolution of the IncA and IncC family of plasmids. Front Microbiol 2022; 13:1045314. [DOI: 10.3389/fmicb.2022.1045314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022] Open
Abstract
Incompatibility groups IncA and IncC plasmids are of great concern due to their ability to disseminate antibiotic resistance in bacteria via conjugative transfer. A deep understanding of their genomic structures and evolutionary characteristics is of great significance for improving our knowledge about its multidrug-resistance evolution and dissemination. However, current knowledge of their backbone structure, features of core functional modules and the characteristics of variable regions is based on a few plasmids, which highlights the need for a comprehensive systematic study. The present study thoroughly compared and analysed 678 IncA and IncC plasmid genomes. We found that their core functional genes were occasionally deficient and sometimes existed as multiple functional copies/multiple families, which resulted in much diversity. The phylogeny of 13 core functional genes corresponded well to the plasmid subtypes. The conjugative transfer system gained diverse complexity and exhibited many previously unnoticed types with multiple combinations. The insertion of mobile genetic elements (MGEs) in plasmids varied between types and was present in 4 insertion spots in different types of plasmids with certain types of transposons, integrons and insertion sequences. The impact of gene duplication, deletion, the insertion of MGEs, genome rearrangement and recombination resulted in the complex dynamic variable backbone of IncA and IncC plasmids. And IncA and IncC plasmids were more complex than their closest relative SXT/R391 integrative conjugative elements (ICEs), which included nearly all of the diversity of SXT/R391 in key systems. Our work demonstrated a global and systematic view of the IncA and IncC plasmids and provides many new insights into their genome evolution.
Collapse
|
5
|
Genomic Analysis of Two MDR Isolates of Salmonella enterica Serovar Infantis from a Spanish Hospital Bearing the blaCTX-M-65 Gene with or without fosA3 in pESI-like Plasmids. Antibiotics (Basel) 2022; 11:antibiotics11060786. [PMID: 35740192 PMCID: PMC9219668 DOI: 10.3390/antibiotics11060786] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/02/2022] [Accepted: 06/05/2022] [Indexed: 02/04/2023] Open
Abstract
Salmonella enterica serovar Infantis (S. Infantis) is a broiler-associated pathogen which ranks in the fourth position as a cause of human salmonellosis in the European Union. Here, we report a comparative genomic analysis of two clinical S. Infantis isolates recovered in Spain from children who just returned from Peru. The isolates were selected on the basis of resistance to cefotaxime, one of the antibiotics of choice for treatment of S. enterica infections. Antimicrobial susceptibility testing demonstrated that they were resistant to eight classes of antimicrobial agents: penicillins, cephalosporins, phenicols, aminoglycosides, tetracyclines, inhibitors of folate synthesis, (fluoro)quinolones and nitrofurans, and one of them was also resistant to fosfomycin. As shown by whole-genome sequence analysis, each isolate carried a pESI-like megaplasmid of ca. 300 kb harboring multiple resistance genes [blaCTX-M-65, aph(4)-Ia, aac(3)-IVa, aph(3′)-Ia, floR, dfrA14, sul1, tet(A), aadA1 ± fosA3], as well as genes for resistance to heavy metals and disinfectants (mer, ars and qacEΔ1). These genes were distributed in two complex regions, separated by DNA belonging to the plasmid backbone, and associated with a wealth of transposable elements. The two isolates had a D87Y amino acid substitution in the GyrA protein, and truncated variants of the nitroreductase genes nfsA and nsfB, accounting for chromosomally encoded resistances to nalidixic acid and nitrofurantoin, respectively. The two S. Infantis isolates were assigned to sequence type ST32 by in silico multilocus sequence typing (MLST). Phylogenetic analysis revealed that they were closely related, differing only by 12 SNPs, although they were recovered from different children two years apart. They were also genetically similar to blaCTX-M-65-positive ± fosA3 isolates obtained from humans and along the poultry production chain in the USA, South America, as well as from humans in several European countries, usually associated with a travel history to America. However, this is the first time that the S. Infantis blaCTX-M-65 ± fosA3 MDR clone has been reported in Spain.
Collapse
|
6
|
Vázquez X, García V, Fernández J, Bances M, de Toro M, Ladero V, Rodicio R, Rodicio MR. Colistin Resistance in Monophasic Isolates of Salmonella enterica ST34 Collected From Meat-Derived Products in Spain, With or Without CMY-2 Co-production. Front Microbiol 2022; 12:735364. [PMID: 35069462 PMCID: PMC8770973 DOI: 10.3389/fmicb.2021.735364] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/17/2021] [Indexed: 12/02/2022] Open
Abstract
Colistin is a last-resort antibiotic in fighting severe infections caused by multidrug resistant Gram negative pathogens in hospitals. Zoonotic bacteria acquire colistin resistance in animal reservoirs and mediate its spread along the food chain. This is the case of non-typhoid serovars of Salmonella enterica. Colistin-resistant S. enterica in foods represents a threat to human health. Here, we assessed the prevalence of colistin-resistance in food-borne isolates of S. enterica (2014–2019; Asturias, Spain), and established the genetic basis and transferability of this resistance. Five out of 231 isolates tested (2.2%) were resistant to colistin. Four of them, belonging to the European monophasic ST34 clone of S. Typhimurium, were characterized in the present study. They were collected from pork or pork and beef meat-derived products, either in 2015 (three isolates) or 2019 (one isolate). Molecular typing with XbaI-PFGE and plasmid profiling revealed distinct patterns for each isolate, even though two of the 2015 isolates derived from the same sample. The MICs of colistin ranged from 8 to 16 mg/L. All isolates carried the mcr-1.1 gene located on conjugative plasmids of the incompatibility groups IncX4 (2015 isolates) or IncHI2 (2019 isolate). Apart from colistin resistance, the four isolates carried chromosomal genes conferring resistance to ampicillin, streptomycin, sulfonamides and tetracycline [blaTEM–1, strA-strB, sul2, and tet(B)] and heavy metals, including copper and silver (silESRCFBAGP and pcoGE1ABCDRSE2), arsenic (arsRSD2A2BCA1D1) ± mercury (merEDACPTR), which are characteristically associated with the European ST34 monophasic clone. The 2019 isolate was also resistant to other antibiotics, comprising third generation cephalosporins and cephamycins. The latter phenotype was conferred by the blaCMY–2 gene located on an IncI1-I(α)-ST2 plasmid. Results in the present study identified meat-derived products as a reservoir of a highly successful clone harboring transferable plasmids which confer resistance to colistin and other clinically important antibiotics. An important reduction in the number of food-borne S. enterica detected during the period of the study, together with the low frequency of colistin resistance, underlines the success of One Health initiatives, such as those implemented at the UE, to control zoonotic bacteria along the food chain and to halt the spread of antimicrobial resistance.
Collapse
Affiliation(s)
- Xenia Vázquez
- Área de Microbiología, Departamento de Biología Funcional, Universidad de Oviedo, Oviedo, Spain.,Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Vanesa García
- Laboratorio de Referencia de Escherichia coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela (USC), Lugo, Spain
| | - Javier Fernández
- Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain.,Servicio de Microbiología, Hospital Universitario Central de Asturias (HUCA), Oviedo, Spain
| | - Margarita Bances
- Laboratorio de Salud Pública (LSP), Consejería de Sanidad del Principado de Asturias, Oviedo, Spain
| | - María de Toro
- Plataforma de Genómica y Bioinformática, Centro de Investigación Biomédica de La Rioja (CIBIR), Logroño, Spain
| | - Víctor Ladero
- Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas (IPLA-CSIC), Villaviciosa, Spain.,Grupo de Microbiología Molecular, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - Rosaura Rodicio
- Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain.,Departamento de Bioquímica y Biología Molecular, Universidad de Oviedo, Oviedo, Spain
| | - M Rosario Rodicio
- Área de Microbiología, Departamento de Biología Funcional, Universidad de Oviedo, Oviedo, Spain.,Grupo de Microbiología Traslacional, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| |
Collapse
|