Associations between antibiotic resistance and bacteriophage resistance phenotypes in laboratory and clinical strains of Salmonella enterica subsp. enterica serovar Typhimurium

2020 ◽  
Vol 143 ◽  
pp. 104159
Author(s):  
Md Jalal Uddin ◽  
Juhee Ahn
Keyword(s):  
Antibiotic Resistance ◽  
Salmonella Enterica ◽  
Clinical Strains ◽  
Bacteriophage Resistance ◽  
Serovar Typhimurium

scholarly journals Understanding the basis of antibiotic resistance: a platform for drug discovery

Microbiology ◽  
2014 ◽  
Vol 160 (11) ◽  
pp. 2366-2373 ◽  
Author(s):  
Laura J. V. Piddock
Keyword(s):  
Antibiotic Resistance ◽  
Salmonella Enterica ◽  
Efflux Pump ◽  
Antibiotic Resistance Genes ◽  
Multi Drug Resistance ◽  
Annual Conference ◽  
Altered Expression ◽  
Genetic Inactivation ◽  
Fluoroquinolone Antibiotics ◽  
Serovar Typhimurium

There are numerous genes in Salmonella enterica serovar Typhimurium that can confer resistance to fluoroquinolone antibiotics, including those that encode topoisomerase proteins, the primary targets of this class of drugs. However, resistance is often multifactorial in clinical isolates and it is not uncommon to also detect mutations in genes that affect the expression of proteins involved in permeability and multi-drug efflux. The latter mechanism, mediated by tripartite efflux systems, such as that formed by the AcrAB–TolC system, confers inherent resistance to many antibiotics, detergents and biocides. Genetic inactivation of efflux genes gives multi-drug hyper-susceptibility, and in the absence of an intact AcrAB–TolC system some chromosomal and transmissible antibiotic resistance genes no longer confer clinically relevant levels of resistance. Furthermore, a functional multi-drug resistance efflux pump, such as AcrAB–TolC, is required for virulence and the ability to form a biofilm. In part, this is due to altered expression of virulence and biofilm genes being sensitive to efflux status. Efflux pump expression can be increased, usually due to mutations in regulatory genes, and this confers resistance to clinically useful drugs such as fluoroquinolones and β-lactams. Here, I discuss some of the work my team has carried out characterizing the mechanisms of antibiotic resistance in Salmonella enterica serovar Typhimurium from the late 1980s to 2014. A video of this Prize Lecture, presented at the Society for General Microbiology Annual Conference 2014, can be viewed via this link: https://www.youtube.com/watch?v=MCRumMV99Yw.

scholarly journals Assessment of Antibiotic Resistance Phenotype and Integrons in Salmonella enterica serovar Typhimurium Isolated from Swine

2008 ◽  
Vol 70 (10) ◽  
pp. 1133-1137 ◽  
Author(s):  
Nabin RAYAMAJHI ◽  
Sang Gyun KANG ◽  
Mi Lan KANG ◽  
Hee Soo LEE ◽  
Kyung Yoon PARK ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Resistance Phenotype ◽  
Serovar Typhimurium

scholarly journals Alterations of Salmonella enterica Serovar Typhimurium Antibiotic Resistance under Environmental Pressure

2018 ◽  
Vol 84 (19) ◽  
Author(s):  
Mengfei Peng ◽  
Serajus Salaheen ◽  
Robert L. Buchanan ◽  
Debabrata Biswas
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Salmonella Enterica ◽  
Tetracycline Resistance ◽  
Multidrug Resistant ◽  
Genetic Alterations ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Farm Systems ◽  
Serovar Typhimurium

ABSTRACT Microbial horizontal gene transfer is a continuous process that shapes bacterial genomic adaptation to the environment and the composition of concurrent microbial ecology. This includes the potential impact of synthetic antibiotic utilization in farm animal production on overall antibiotic resistance issues; however, the mechanisms behind the evolution of microbial communities are not fully understood. We explored potential mechanisms by experimentally examining the relatedness of phylogenetic inference between multidrug-resistant Salmonella enterica serovar Typhimurium isolates and pathogenic Salmonella Typhimurium strains based on genome-wide single-nucleotide polymorphism (SNP) comparisons. Antibiotic-resistant S. Typhimurium isolates in a simulated farm environment barely lost their resistance, whereas sensitive S. Typhimurium isolates in soils gradually acquired higher tetracycline resistance under antibiotic pressure and manipulated differential expression of antibiotic-resistant genes. The expeditious development of antibiotic resistance and the ensuing genetic alterations in antimicrobial resistance genes in S. Typhimurium warrant effective actions to control the dissemination of Salmonella antibiotic resistance. IMPORTANCE Antibiotic resistance is attributed to the misuse or overuse of antibiotics in agriculture, and antibiotic resistance genes can also be transferred to bacteria under environmental stress. In this study, we report a unidirectional alteration in antibiotic resistance from susceptibility to increased resistance. Highly sensitive Salmonella enterica serovar Typhimurium isolates from organic farm systems quickly acquired tetracycline resistance under antibiotic pressure in simulated farm soil environments within 2 weeks, with expression of antibiotic resistance-related genes that was significantly upregulated. Conversely, originally resistant S. Typhimurium isolates from conventional farm systems lost little of their resistance when transferred to environments without antibiotic pressure. Additionally, multidrug-resistant S. Typhimurium isolates genetically shared relevancy with pathogenic S. Typhimurium isolates, whereas susceptible isolates clustered with nonpathogenic strains. These results provide detailed discussion and explanation about the genetic alterations and simultaneous acquisition of antibiotic resistance in S. Typhimurium in agricultural environments.

scholarly journals Antibiotic Resistance in Salmonella enterica Serovar Typhimurium Exposed to Microcin-Producing Escherichia coli

2001 ◽  
Vol 67 (8) ◽  
pp. 3763-3766 ◽  
Author(s):  
Steve A. Carlson ◽  
Timothy S. Frana ◽  
Ronald W. Griffith
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
Defense Mechanism ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Multidrug Resistant ◽  
E Coli ◽  
Resistant Phenotype ◽  
Serovar Typhimurium

ABSTRACT Microcin 24 is an antimicrobial peptide secreted by uropathogenicEscherichia coli. Secretion of microcin 24 provides an antibacterial defense mechanism for E. coli. In a plasmid-based system using transformed Salmonella enterica, we found that resistance to microcin 24 could be seen in concert with a multiple-antibiotic resistance phenotype. This multidrug-resistant phenotype appeared when Salmonella was exposed to an E. coli strain expressing microcin 24. Therefore, it appears that multidrug-resistant Salmonellacan arise as a result of an insult from other pathogenic bacteria.

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.

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