The Molecular Epidemiological Characteristics and Genetic Diversity of Salmonella Typhimurium in Guangdong, China, 2007–2011

Sun, Jiufeng; Ke, Bixia; Huang, Yanhui; He, Dongmei; Li, Xiaocui; Liang, Zhaoming; Ke, Changwen

doi:10.1371/journal.pone.0113145

Cited by 46 publications

(51 citation statements)

References 34 publications

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“…Recently, mcr-1 was detected in MDR S. Typhimurium/ST34 and S. Typhimurium/ST36 in England and Wales32. Here, all the five mcr-1 -positive Salmonella strains belong to S. Typhimurium/ST34, which is the predominant ST of S. Typhimurium in Guangdong, China34. In our previous study, we have characterized a high prevalence of MDR S. Typhimurium/ST34 carrying PMQR8, which was also frequently detected in human clinical and food samples in Hong Kong in the same period8.…”

Section: Discussionmentioning

confidence: 85%

Clonal spread of mcr-1 in PMQR-carrying ST34 Salmonella isolates from animals in China

Fang

Song

et al. 2016

Sci Rep

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Since initial identification in China, the widespread geographical occurrence of plasmid-mediated colistin resistance gene mcr-1 in Enterobacteriaceae has been of great concern. In this study, a total of 22 Salmonella enterica were resistant to colistin, while only five isolates which belonged to ST34 Salmonella enterica serovar Typhimurium (S. Typhimurium) were mcr-1 positive. Four of them shared nearly identical PFGE type, although they were from different host species and diverse geographical locations. All the mcr-1-positive S. Typhimurium exhibited multi-resistant phenotypes including ampicillin, streptomycin, gentamicin, florfenicol, nalidixic acid, tetracycline, trimethoprim-sulfamethox, in addition to colistin. The oqxAB and aac(6′)-Ib-cr genes were present alone or in combination in four (80.0%) and five (100%) isolates, respectively. The mcr-1 gene was located on a transferable IncI2 plasmid in the four genetically related strains. In the other one strain, mcr-1 was located on an approximately 190 kb IncHI2 plasmid. In conclusion, we report five mcr-1-positive S. Typhimurium/ST34 isolates. Both clonal expansion and horizontal transmission of IncI2-type plasmids were involved in the spread of the mcr-1 gene in Salmonella enterica from food-producing animals in China. There is a great need to monitor the potential dissemination of the mcr-1 gene.

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Section: Discussionmentioning

confidence: 85%

Clonal spread of mcr-1 in PMQR-carrying ST34 Salmonella isolates from animals in China

Fang

Song

et al. 2016

Sci Rep

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“…Sun et al (2014) There are few published studies that have used molecular techniques to evaluate the genotypic diversity of S. Typhimurium strains isolated in Brazil and these studies used only PFGE for this purpose Bessa et al, 2007;Fernandes et al, 2009;Tavechio et al, 2009;Kich et al, 2011).…”

Section: Resultsmentioning

confidence: 99%

Genotypic diversity, pathogenic potential and the resistance profile of Salmonella Typhimurium strains isolated from humans and food from 1983 to 2013 in Brazil

Almeida

Medeiros

Rodrigues

et al. 2015

Journal of Medical Microbiology

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Salmonella enterica subsp. enterica serovar Typhimurium is one of the leading serovars that causes salmonellosis worldwide. However, few studies have molecularly characterized S. Typhimurium strains in Brazil. In this study, we genotyped 92 S. Typhimurium strains isolated from humans (43) and food (49) between 1983 and 2013 in Brazil using PFGE, multiple-locus variable number of tandem repeats analysis (MLVA) and enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Moreover, we assessed the frequency of 12 virulence markers by PCR and the resistance profile against 12 antimicrobials. More than 85.8 % of the strains studied carried 11 of the virulence markers or more. Thirty-three strains (25 %) were multidrug resistant (MDR). The 92 S. Typhimurium studied were grouped by PFGE as PFGE-A, PFGE-B1 and PFGE-B2; by MLVA as MLVA-A, MLVA-B1 and MLVA-B2; and, finally, by ERIC-PCR as ERIC-A and ERIC-B. The strains isolated from humans before the mid-1990s were allocated to all clusters. The strains isolated from humans after the mid-1990s were distributed in the PFGE-B1, MLVA-B1, MLVA-B2 and ERIC-A clusters. The strains isolated from food were distributed in all clusters, except in PFGE-B2. All typing results suggested that the S. Typhimurium strains of human clinical origin isolated before the mid-1990s were genetically more diverse, which might indicate the selection of a more adapted S. Typhimurium subtype after Salmonella Enteritidis became the most prevalent serovar in Brazil. Regarding strains isolated from food, the results suggest the current circulation of more than one subtype. Furthermore, the high frequency of virulence genes and the presence of MDR strains reinforces their potential hazard for humans and the risk of their presence in foods in Brazil.

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“…Typhimurium phylogroups 32,33 . These two groups were more closely related to each other than to other serotypes of S. enterica subspecies I, including the nearest neighbour, serotype Heidelberg.…”

Section: Discussionmentioning

confidence: 99%

Evolution of Salmonella enterica serotype Typhimurium driven by anthropogenic selection and niche adaptation

Bawn

Thilliez

Kirkwood

et al. 2019

Preprint

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Salmonella enterica serotype Typhimurium (S. Typhimurium) is a leading cause of gastroenteritis and disseminated disease worldwide, and a model organism for host pathogen interactions. Genotypic variation of S. Typhimurium results in strains with diverse host range, pathogenicity and risk to food safety. A robust fully parsimonious phylogenetic tree constructed from recombination purged variation in the whole genome sequence of 131 diverse strains of S. Typhimurium revealed population structure composed of two high order clades (α and β) and multiple subclades on extended internal branches, that exhibited distinct signatures of host adaptation and anthropogenic selection. Clade α contained a number of subclades composed of strains from well characterized epidemics in domesticated animals, while clade β predominantly contained subclades associated with wild avian species, with the notable exception of a subclade containing the DT204/49 complex. The contrasting epidemiology of α and β strains was reflected in distinct distribution of antimicrobial resistance (AMR) genes, accumulation of hypothetically disrupted coding sequences (HDCS), and signatures of functional diversification associated with invasiveness of host adapted serotypes. Gene flux was predominantly driven by acquisition, loss or recombination of prophage, awhile acquisition of large genetic islands (SGI-1 and 4) was restricted to two recent pandemic clones (DT104 and monophasic S. Typhimurium ST34) in clade α.Together, our data are consistent with the view that a broad host range common ancestor of S.Typhimurium diversified with clade α lineages remained largely associated with multiple domesticated animal species, while clade β spawned multiple lineages that underwent diversifying selection associated with adaptation to various niches, predominantly in wild avian species.

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The Molecular Epidemiological Characteristics and Genetic Diversity of Salmonella Typhimurium in Guangdong, China, 2007–2011

Cited by 46 publications

References 34 publications

Clonal spread of mcr-1 in PMQR-carrying ST34 Salmonella isolates from animals in China

Clonal spread of mcr-1 in PMQR-carrying ST34 Salmonella isolates from animals in China

Genotypic diversity, pathogenic potential and the resistance profile of Salmonella Typhimurium strains isolated from humans and food from 1983 to 2013 in Brazil

Evolution of Salmonella enterica serotype Typhimurium driven by anthropogenic selection and niche adaptation

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