scholarly journals Antimicrobial resistance in Salmonella enterica subsp. enterica serovar typhimurium from humans and production animals

1997 ◽  
Vol 40 (1) ◽  
pp. 67-75 ◽  
Author(s):  
A. Seyfarth
Keyword(s):  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Serovar Typhimurium ◽  
Production Animals

scholarly journals Clarithromycin Exerts an Antibiofilm Effect against Salmonella enterica Serovar Typhimurium rdar Biofilm Formation and Transforms the Physiology towards an Apparent Oxygen-Depleted Energy and Carbon Metabolism

2020 ◽  
Vol 88 (11) ◽  
Author(s):  
Munirah Zafar ◽  
Humera Jahan ◽  
Sulman Shafeeq ◽  
Manfred Nimtz ◽  
Lothar Jänsch ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Biofilm Formation ◽  
Antibiofilm Activity ◽  
Bacterial Cells ◽  
Content Type ◽  
Regulatory Pathways ◽  
Heat Shock Stress ◽  
Extracellular Matrix Components ◽  
Serovar Typhimurium

ABSTRACT Upon biofilm formation, production of extracellular matrix components and alteration in physiology and metabolism allows bacteria to build up multicellular communities which can facilitate nutrient acquisition during unfavorable conditions and provide protection toward various forms of environmental stresses to individual cells. Thus, bacterial cells within biofilms become tolerant against antimicrobials and the immune system. In the present study, we evaluated the antibiofilm activity of the macrolides clarithromycin and azithromycin. Clarithromycin showed antibiofilm activity against rdar (red, dry, and rough) biofilm formation of the gastrointestinal pathogen Salmonella enterica serovar Typhimurium ATCC 14028 (Nalr) at a 1.56 μM subinhibitory concentration in standing culture and dissolved cell aggregates at 15 μM in a microaerophilic environment, suggesting that the oxygen level affects the activity of the drug. Treatment with clarithromycin significantly decreased transcription and production of the rdar biofilm activator CsgD, with biofilm genes such as csgB and adrA to be concomitantly downregulated. Although fliA and other flagellar regulon genes were upregulated, apparent motility was downregulated. RNA sequencing showed a holistic cell response upon clarithromycin exposure, whereby not only genes involved in the biofilm-related regulatory pathways but also genes that likely contribute to intrinsic antimicrobial resistance, and the heat shock stress response were differentially regulated. Most significantly, clarithromycin exposure shifted the cells toward an apparent oxygen- and energy-depleted status, whereby the metabolism that channels into oxidative phosphorylation was downregulated, and energy gain by degradation of propane 1,2-diol, ethanolamine and l-arginine catabolism, potentially also to prevent cytosolic acidification, was upregulated. This analysis will allow the subsequent identification of novel intrinsic antimicrobial resistance determinants.

scholarly journals Prevalence and Antimicrobial Resistance of Campylobacter spp. and Salmonella Serovars in Organic Chickens from Maryland Retail Stores

2005 ◽  
Vol 71 (7) ◽  
pp. 4108-4111 ◽  
Author(s):  
Shenghui Cui ◽  
Beilei Ge ◽  
Jie Zheng ◽  
Jianghong Meng
Keyword(s):  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Retail Stores ◽  
Serovar Typhimurium ◽  
Salmonella Serovars ◽  
Campylobacter Spp

ABSTRACT Retail organic (n = 198) and conventional (n = 61) chickens were analyzed. Most organic (76%) and conventional (74%) chickens were contaminated with campylobacters. Salmonellae were recovered from 61% of organic and 44% of conventional chickens. All Salmonella enterica serovar Typhimurium isolates from conventional chickens were resistant to five or more antimicrobials, whereas most S. enterica serovar Typhimurium isolates (79%) from organic chickens were susceptible to 17 antimicrobials tested.

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 Genotypic and Phenotypic Characterization of Incompatibility Group FIB Positive Salmonella enterica Serovar Typhimurium Isolates from Food Animal Sources

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1307
Author(s):  
Nesreen H. Aljahdali ◽  
Bijay K. Khajanchi ◽  
Kennedi Weston ◽  
Joanna Deck ◽  
Justin Cox ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Virulence Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Incompatibility Group ◽  
Cell Counts ◽  
Food Animal ◽  
Animal Populations ◽  
Plasmid Replicon ◽  
Serovar Typhimurium

Salmonella enterica is one of the most common bacterial foodborne pathogens in the United States, causing illnesses that range from self-limiting gastroenteritis to more severe, life threatening invasive disease. Many Salmonella strains contain plasmids that carry virulence, antimicrobial resistance, and/or transfer genes which allow them to adapt to diverse environments, and these can include incompatibility group (Inc) FIB plasmids. This study was undertaken to evaluate the genomic and phenotypic characteristics of IncFIB-positive Salmonella enterica serovar Typhimurium isolates from food animal sources, to identify their plasmid content, assess antimicrobial resistance and virulence properties, and compare their genotypic isolates with more recently isolated S. Typhimurium isolates from food animal sources. Methods: We identified 71 S. Typhimurium isolates that carried IncFIB plasmids. These isolates were subjected to whole genome sequencing and evaluated for bacteriocin production, antimicrobial susceptibility, the ability to transfer resistance plasmids, and a subset was evaluated for their ability to invade and persist in intestinal human epithelial cells. Results: Approximately 30% of isolates (n = 21) displayed bacteriocin inhibition of Escherichia coli strain J53. Bioinformatic analyses using PlasmidFinder software confirmed that all isolates contained IncFIB plasmids along with multiple other plasmid replicon types. Comparative analyses showed that all strains carried multiple antimicrobial resistance genes and virulence factors including iron acquisition genes, such as iucABCD (75%), iutA (94%), sitABCD (76%) and sitAB (100%). In 17 cases (71%), IncFIB plasmids, along with other plasmid replicon types, were able to conjugally transfer antimicrobial resistance and virulence genes to the susceptible recipient strain. For ten strains, persistence cell counts (27%) were noted to be significantly higher than invasion bacterial cell counts. When the genome sequences of the study isolates collected from 1998–2003 were compared to those published from subsequent years (2005–2018), overlapping genotypes were found, indicating the perseverance of IncFIB positive strains in food animal populations. This study confirms that IncFIB plasmids can play a potential role in disseminating antimicrobial resistance and virulence genes amongst bacteria from several food animal species.

Sign in / Sign up

Export Citation Format

Share Document