scholarly journals Prevalence of ColE1-Like Plasmids and Kanamycin Resistance Genes in Salmonella enterica Serovars

2010 ◽  
Vol 76 (20) ◽  
pp. 6707-6714 ◽  
Author(s):  
Chin-Yi Chen ◽  
Rebecca L. Lindsey ◽  
Terence P. Strobaugh ◽  
Jonathan G. Frye ◽  
Richard J. Meinersmann
Keyword(s):  
Resistance Genes ◽  
Salmonella Enterica ◽  
Critical Role ◽  
Antibiotic Resistance Genes ◽  
Kanamycin Resistance ◽  
Close Monitoring ◽  
Incompatibility Group ◽  
Serovar Typhimurium ◽  
Cole1 Plasmid ◽  
Primer Sets

ABSTRACT Multi-antimicrobial-resistant Salmonella enterica strains frequently carry resistance genes on plasmids. Recent studies focus heavily on large conjugative plasmids, and the role that small plasmids play in resistance gene transfer is largely unknown. To expand our previous studies in assessing the prevalence of the isolates harboring ColE1-like plasmids carrying the aph gene responsible for kanamycin resistance (Kanr) phenotypes, 102 Kanr Salmonella isolates collected through the National Antimicrobial Resistance Monitoring System (NARMS) in 2005 were screened by PCR using ColE1 primer sets. Thirty isolates were found to be positive for ColE1-like replicon. Plasmids from 23 isolates were able to propagate in Escherichia coli and were subjected to further characterization. Restriction mapping revealed three major plasmid groups found in three or more isolates, with each group consisting of two to three subtypes. The aph genes from the Kanr Salmonella isolates were amplified by PCR, sequenced, and showed four different aph(3′)-I genes. The distribution of the ColE1 plasmid groups in association with the aph gene, Salmonella serovar, and isolate source demonstrated a strong linkage of the plasmid with S. enterica serovar Typhimurium DT104. Due to their high copy number and mobility, the ColE1-like plasmids may play a critical role in transmission of antibiotic resistance genes among enteric pathogens, and these findings warrant a close monitoring of this plasmid incompatibility group.

scholarly journals Antibiotic Resistance Genes and Salmonella Genomic Island 1 in Salmonella enterica Serovar Typhimurium Isolated in Italy

2002 ◽  
Vol 46 (9) ◽  
pp. 2821-2828 ◽  
Author(s):  
Alessandra Carattoli ◽  
Emma Filetici ◽  
Laura Villa ◽  
Anna Maria Dionisi ◽  
Antonia Ricci ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Salmonella Enterica ◽  
Genomic Island ◽  
Antibiotic Resistance Genes ◽  
Tetracycline Resistance ◽  
Gene Cassette ◽  
Multidrug Resistant ◽  
Phage Types ◽  
Serovar Typhimurium

ABSTRACT Fifty-four epidemiologically unrelated multidrug-resistant Salmonella enterica serovar Typhimurium isolates, collected between 1992 and 2000 in Italy, were analyzed for the presence of integrons. Strains were also tested for Salmonella genomic island 1 (SGI1), carrying antibiotic resistance genes in DT104 strains. A complete SGI1 was found in the majority of the DT104 strains. Two DT104 strains, showing resistance to streptomycin-spectinomycin and sulfonamides, carried a partially deleted SGI1 lacking the flost , tetR, and tetA genes, conferring chloramphenicol-florfenicol and tetracycline resistance, and the integron harboring the pse-1 gene cassette, conferring ampicillin resistance. The presence of SGI1 was also observed in serovar Typhimurium strains belonging to other phage types, suggesting either the potential mobility of this genomic island or changes in the phage-related phenotype of DT104 strains.

scholarly journals Whole-Genome Sequences of 66 Incompatibility Group FIB Plasmid-Carrying Salmonella enterica Serovar Typhimurium Isolates from Food Animal Sources

2020 ◽  
Vol 9 (5) ◽  
Author(s):  
Nesreen H. Aljahdali ◽  
Steven L. Foley ◽  
Jing Han ◽  
Yasser M. Sanad ◽  
Rajesh Nayak ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Incompatibility Group ◽  
Content Type ◽  
Factors Associated ◽  
Food Animal ◽  
Antimicrobial Resistance Genes ◽  
Serovar Typhimurium

Sixty-six Salmonella enterica serovar Typhimurium isolates carrying incompatibility group FIB (IncFIB) plasmids were sequenced to further characterize the IncFIB plasmid-encoded factors associated with virulence and antimicrobial resistance genes. In addition to the IncFIB plasmid, many of these isolates harbored additional plasmids encoding virulence and antimicrobial resistance genes.

scholarly journals Multidrug-Resistant Salmonella enterica Serovar Paratyphi A Harbors IncHI1 Plasmids Similar to Those Found in Serovar Typhi

2007 ◽  
Vol 189 (11) ◽  
pp. 4257-4264 ◽  
Author(s):  
Kathryn E. Holt ◽  
Nicholas R. Thomson ◽  
John Wain ◽  
Minh Duy Phan ◽  
Satheesh Nair ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Salmonella Enterica ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Mobile Elements ◽  
Mobile Dna ◽  
Serovar Typhimurium ◽  
Dna Elements ◽  
Dna Backbone

ABSTRACT Salmonella enterica serovars Typhi and Paratyphi A cause systemic infections in humans which are referred to as enteric fever. Multidrug-resistant (MDR) serovar Typhi isolates emerged in the 1980s, and in recent years MDR serovar Paratyphi A infections have become established as a significant problem across Asia. MDR in serovar Typhi is almost invariably associated with IncHI1 plasmids, but the genetic basis of MDR in serovar Paratyphi A has remained predominantly undefined. The DNA sequence of an IncHI1 plasmid, pAKU_1, encoding MDR in a serovar Paratyphi A strain has been determined. Significantly, this plasmid shares a common IncHI1-associated DNA backbone with the serovar Typhi plasmid pHCM1 and an S. enterica serovar Typhimurium plasmid pR27. Plasmids pAKU_1 and pHCM1 share 14 antibiotic resistance genes encoded within similar mobile elements, which appear to form a 24-kb composite transposon that has transferred as a single unit into different positions into their IncHI1 backbones. Thus, these plasmids have acquired similar antibiotic resistance genes independently via the horizontal transfer of mobile DNA elements. Furthermore, two IncHI1 plasmids from a Vietnamese isolate of serovar Typhi were found to contain features of the backbone sequence of pAKU_1 rather than pHCM1, with the composite transposon inserted in the same location as in the pAKU_1 sequence. Our data show that these serovar Typhi and Paratyphi A IncHI1 plasmids share highly conserved core DNA and have acquired similar mobile elements encoding antibiotic resistance genes in past decades.

scholarly journals Diverse and Flexible Transmission of fosA3 Associated with Heterogeneous Multidrug Resistance Regions in Salmonella enterica Serovar Typhimurium and Indiana Isolates

2019 ◽  
Vol 64 (2) ◽  
Author(s):  
Liang-Xing Fang ◽  
Qi Jiang ◽  
Guo-Hui Deng ◽  
Bing He ◽  
Ruan-Yang Sun ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Resistance Genes ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Antibiotic Resistance Genes ◽  
Guangdong Province ◽  
Great Flexibility ◽  
Serovar Typhimurium ◽  
M 14

ABSTRACT We identified fosA3 at a rate of 2.6% in 310 Salmonella isolates from food animals in Guangdong province, China. The fosA3 gene was genetically linked to diverse antibiotic resistance genes (ARGs), including mcr-1, blaCTX-M-14/55, oqxAB, and rmtB. These gene combinations were embedded in heterogeneous fosA3-containing multidrug resistance regions on the transferable ST3-IncHI2 and F33:A−:B− plasmids and the chromosome. This indicated a great flexibility of fosA3 cotransmission with multiple important ARGs among Salmonella species.

scholarly journals Distribution of prophages and SGI-1 antibiotic-resistance genes among different Salmonella enterica serovar Typhimurium isolates

Microbiology ◽  
2006 ◽  
Vol 152 (7) ◽  
pp. 2137-2147 ◽  
Author(s):  
Armand P. H. M. Hermans ◽  
Annelien M. Beuling ◽  
Angela H. A. M. van Hoek ◽  
Henk J. M. Aarts ◽  
Tjakko Abee ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Salmonella Enterica ◽  
Phage Type ◽  
Antibiotic Resistance Genes ◽  
Subtractive Hybridization ◽  
The Novel ◽  
Additional Information ◽  
Phage Types ◽  
Serovar Typhimurium

Recently, the authors identified Salmonella enterica serovar Typhimurium (S. Typhimurium) definitive type (DT)104-specific sequences of mainly prophage origin by genomic subtractive hybridization. In the present study, the distribution of the prophages identified, ST104 and ST64B, and the novel prophage remnant designated prophage ST104B, was tested among 23 non-DT104 S. Typhimurium isolates of different phage types and 19 isolates of the DT104 subtypes DT104A, DT104B low and DT104L, and the DT104-related type U302. The four S. Typhimurium prophages Gifsy-1, Gifsy-2, Fels-1 and Fels-2 were also included. Analysis of prophage distribution in different S. Typhimurium isolates may supply additional information to enable development of a molecular method as an alternative to phage typing. Furthermore, the presence of the common DT104 antibiotic resistance genes for the penta-resistance type ACSSuT, aadA2, floR, pse-1, sul1 and tet(G), was also studied because of the authors' focus on this emerging type. Based on differences in prophage presence within their genome, it was possible to divide S. Typhimurium isolates into 12 groups. Although no clear relationship was found between different phage type and prophage presence, discrimination could be made between the different DT104 subtypes based on diversity in the presence of prophages ST104, ST104B and ST64B. The novel prophage remnant ST104B, which harbours a homologue of the Escherichia coli O157 : H7 HldD LPS assembly-related protein, was identified only in the 14 DT104L isolates and in the DT104-related U302 isolate. In conclusion, the presence of the genes for penta-resistance type ACSSuT, the HldD homologue containing ST104 prophage remnant and phage type DT104L are most likely common features of the emerging subtype of S. Typhimurium DT104.

scholarly journals Contribution of Target Gene Mutations and Efflux to Decreased Susceptibility of Salmonella enterica Serovar Typhimurium to Fluoroquinolones and Other Antimicrobials

2006 ◽  
Vol 51 (2) ◽  
pp. 535-542 ◽  
Author(s):  
Sheng Chen ◽  
Shenghui Cui ◽  
Patrick F. McDermott ◽  
Shaohua Zhao ◽  
David G. White ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Efflux Pump ◽  
Critical Role ◽  
Gene Mutations ◽  
Efflux Pumps ◽  
Fluoroquinolone Resistance ◽  
Naturally Occurring ◽  
Serovar Typhimurium ◽  
Resistant Mutants ◽  
Increased Susceptibility

ABSTRACT The mechanisms involved in fluoroquinolone resistance in Salmonella enterica include target alterations and overexpression of efflux pumps. The present study evaluated the role of known and putative multidrug resistance efflux pumps and mutations in topoisomerase genes among laboratory-selected and naturally occurring fluoroquinolone-resistant Salmonella enterica serovar Typhimurium strains. Strains with ciprofloxacin MICs of 0.25, 4, 32, and 256 μg/ml were derived in vitro using serovar Typhimurium S21. These mutants also showed decreased susceptibility or resistance to many nonfluoroquinolone antimicrobials, including tetracycline, chloramphenicol, and several β-lactams. The expression of efflux pump genes acrA, acrB, acrE, acrF, emrB, emrD, and mdlB were substantially increased (≥2-fold) among the fluoroquinolone-resistant mutants. Increased expression was also observed, but to a lesser extent, with three other putative efflux pumps: mdtB (yegN), mdtC (yegO), and emrA among mutants with ciprofloxacin MICs of ≥32 μg/ml. Deletion of acrAB or tolC in S21 and its fluoroquinolone-resistant mutants resulted in increased susceptibility to fluoroquinolones and other tested antimicrobials. In naturally occurring fluoroquinolone-resistant serovar Typhimurium strains, deletion of acrAB or tolC increased fluoroquinolone susceptibility 4-fold, whereas replacement of gyrA double mutations (S83F D87N) with wild-type gyrA increased susceptibility >500-fold. These results indicate that a combination of topoisomerase gene mutations, as well as enhanced antimicrobial efflux, plays a critical role in the development of fluoroquinolone resistance in both laboratory-derived and naturally occurring quinolone-resistant serovar Typhimurium strains.

scholarly journals Characterization of the Genomes of a Diverse Collection of Salmonella enterica Serovar Typhimurium Definitive Phage Type 104

2008 ◽  
Vol 190 (24) ◽  
pp. 8155-8162 ◽  
Author(s):  
Fiona J. Cooke ◽  
Derek J. Brown ◽  
Maria Fookes ◽  
Derek Pickard ◽  
Alasdair Ivens ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Fragment Size ◽  
Phage Type ◽  
Antibiotic Resistance Genes ◽  
Serovar Typhimurium ◽  
Mlst Type ◽  
Plasmid Profiling ◽  
Type Sequence

ABSTRACT Salmonella enterica serovar Typhimurium definitive phage type 104 (DT104) has caused significant morbidity and mortality in humans and animals for almost three decades. We completed the full DNA sequence of one DT104 strain, NCTC13348, and showed that significant differences between the genome of this isolate and the genome of the previously sequenced strain Salmonella serovar Typhimurium LT2 are due to integrated prophage elements and Salmonella genomic island 1 encoding antibiotic resistance genes. Thirteen isolates of Salmonella serovar Typhimurium DT104 with different pulsed-field gel electrophoresis (PFGE) profiles were analyzed by using multilocus sequence typing (MLST), plasmid profiling, hybridization to a pan-Salmonella DNA microarray, and prophage-based multiplex PCR. All the isolates belonged to a single MLST type, sequence type ST19. Microarray data demonstrated that the gene contents of the 13 DT104 isolates were remarkably conserved. The PFGE DNA fragment size differences in these isolates could be explained to a great extent by differences in the prophage and plasmid contents. Thus, here the nature of variation in different Salmonella serovar Typhimurium DT104 isolates is further defined at the gene and whole-genome levels, illustrating how this phage type evolves over time.

scholarly journals Role for Neutrophils in Host Immune Responses and Genetic Factors That Modulate Resistance to Salmonella enterica Serovar Typhimurium in the Inbred Mouse Strain SPRET/Ei

2010 ◽  
Vol 78 (9) ◽  
pp. 3848-3860 ◽  
Author(s):  
Lien Dejager ◽  
Iris Pinheiro ◽  
Pieter Bogaert ◽  
Liesbeth Huys ◽  
Claude Libert
Keyword(s):  
Mouse Strain ◽  
Salmonella Enterica ◽  
Genetic Factors ◽  
Inbred Mouse ◽  
Critical Role ◽  
Inbred Mouse Strain ◽  
Natural Resistance ◽  
Host Bacterium ◽  
A Genome ◽  
Serovar Typhimurium

ABSTRACT Infection with Salmonella enterica serovar Typhimurium is a complex disease in which the host-bacterium interactions are strongly influenced by genetic factors of the host. We demonstrate that SPRET/Ei, an inbred mouse strain derived from Mus spretus, is resistant to S. Typhimurium infections. The kinetics of bacterial proliferation, as well as histological examinations of tissue sections, suggest that SPRET/Ei mice can control bacterial multiplication and spreading despite significant attenuation of the cytokine response. The resistance of SPRET/Ei mice to S. Typhimurium infection is associated with increased leukocyte counts in the circulation and enhanced neutrophil influx into the peritoneum during the course of infection. A critical role of neutrophils was confirmed by neutrophil depletion: neutropenic SPRET/Ei mice were sensitive to infection with S. Typhimurium and showed much higher bacterial loads. To identify genes that modulate the natural resistance of SPRET/Ei mice to S. Typhimurium infection, we performed a genome-wide study using an interspecific backcross between C3H/HeN and SPRET/Ei mice. The results of this analysis demonstrate that at least two loci, located on chromosomes 6 and 11, affect survival following lethal infection with S. Typhimurium. These two loci contain several interesting candidate genes which may have important implications for the search for genetic factors controlling Salmonella infections in humans and for our understanding of complex host-pathogen interactions in general.

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