scholarly journals Diversified mcr-1 -Harbouring Plasmid Reservoirs Confer Resistance to Colistin in Human Gut Microbiota

mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Huiyan Ye ◽  
Yihui Li ◽  
Zhencui Li ◽  
Rongsui Gao ◽  
Han Zhang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Multidrug Resistant ◽  
Global Public Health ◽  
Colistin Resistance ◽  
Human Gut ◽  
Gram Negative ◽  
Sequence Mapping ◽  
Human Gut Microbiota ◽  
Functional Analyses ◽  
Conventional Idea

ABSTRACT Colistin is an ultimate line of refuge against multidrug-resistant Gram-negative pathogens. Very recently, the emergence of plasmid-mediated mcr-1 colistin resistance has become a great challenge to global public health, raising the possibility that dissemination of the mcr-1 gene is underestimated and diversified. Here, we report three cases of plasmid-carried MCR-1 colistin resistance in isolates from gut microbiota of diarrhea patients. Structural and functional analyses determined that the colistin resistance is conferred purely by the single mcr-1 gene. Genetic and sequence mapping revealed that mcr-1 -harbouring plasmid reservoirs are present in diversity. Together, the data represent the first evidence of diversity in mcr-1 -harbouring plasmid reservoirs of human gut microbiota. IMPORTANCE The plasmid-mediated mobile colistin resistance gene ( mcr-1 ) challenged greatly the conventional idea mentioned above that colistin is an ultimate line of refuge against lethal infections by multidrug-resistant Gram-negative pathogens. It is a possibility that diversified dissemination of the mcr-1 gene might be greatly underestimated. We report three cases of plasmid-carried MCR-1 colistin resistance in isolates from gut microbiota of diarrhea patients and functionally define the colistin resistance conferred purely by the single mcr-1 gene. Genetic and sequence mapping revealed unexpected diversity among the mcr-1 -harbouring plasmid reservoirs of human gut microbiota.

scholarly journals The role of the human gut microbiota in colonization and infection with multidrug-resistant bacteria

Gut Microbes ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 1-13
Author(s):  
Irene Wuethrich ◽  
Benedikt W. Pelzer ◽  
Yascha Khodamoradi ◽  
Maria J. G. T. Vehreschild
Keyword(s):  
Gut Microbiota ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Human Gut ◽  
Multidrug Resistant Bacteria ◽  
Human Gut Microbiota

scholarly journals Whole-genome analysis of antimicrobial-resistant Escherichia coli in human gut microbiota reveals its origin and flexibility in transmitting mcr-1

2021 ◽  
Author(s):  
Yichen Ding ◽  
Woei-Yuh Saw ◽  
Linda Wei Lin Tan ◽  
Don Kyin Nwe Moong ◽  
Niranjan Nagarajan ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Gut Microbiota ◽  
Resistance Gene ◽  
Meat Products ◽  
Colistin Resistance ◽  
Human Gut ◽  
Antibiotic Resistant ◽  
Raw Meat ◽  
E Coli ◽  
Human Gut Microbiota

AbstractMultidrug resistant (MDR) Escherichia coli strains that carry extended-spectrum β-lactamases (ESBLs) or colistin resistance gene mcr-1 have been identified in the human gut at an increasing incidence worldwide. In this study, we sampled and characterized MDR Enterobacteriaceae from the gut microbiota of healthy Singaporeans and show that the prevalence of ESBL-producing and mcr-positive Enterobacteriaceae is 26.6% and 7.3%, respectively. Whole-genome sequencing of 37 E. coli isolates identified 25 sequence types and assigned them into six different phylogroups, suggesting that the human intestinal MDR E. coli strains are highly diverse. In addition, we found that E. coli isolates belonging to phylogroup D, B2 and F carry a higher number of virulence genes, whereas isolates of phylogroup A, B1 and E carry fewer virulence factor genes but are frequent carriers of florfenicol resistance gene floR and colistin resistance gene mcr-1. Comparison of the seven mcr-1-positive E. coli isolates revealed that mcr-1 is carried by conjugative plasmids or embedded in composite transposons, which could potentially mobilize mcr-1 to other pathogenic Enterobacteriaceae strains or MDR plasmids. Finally, we found that 12 out of the 37 MDR E. coli isolates in this study show high similarity to ESBL-producing E. coli isolates from raw meats from local markets, suggesting a potential transmission of MDR E. coli from meat products to the human gut microbiota. Our findings show diverse antibiotic resistance and virulence profiles of intestinal E. coli and call for better countermeasures to block the transmission of MDR E. coli via the food chain.ImportanceThe human gut can harbor both antibiotic resistant and virulent E. coli which may subsequently cause infections. In this study, the antibiotic resistance and virulence traits of antibiotic-resistant E. coli isolates from human gut microbiota of healthy subjects were investigated. The isolated E. coli strains carry a diverse range of antibiotic resistance mechanisms and virulence factor genes, are highly diverse to each other, and are likely to originate from raw meat products from the local markets. Of particular concern are seven E. coli isolates which carry colistin resistance gene mcr-1. This gene can be mobilized into other pathogens and MDR plasmids, thereby spreading resistance to the last-resort antibiotic colistin. Our findings also suggest that raw meat could serve as important source to transmit MDR bacteria into the human gut microbiota.

scholarly journals Molecular Studies Neglect Apparently Gram-Negative Populations in the Human Gut Microbiota

2013 ◽  
Vol 51 (10) ◽  
pp. 3286-3293 ◽  
Author(s):  
P. Hugon ◽  
J.-C. Lagier ◽  
C. Robert ◽  
C. Lepolard ◽  
L. Papazian ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Human Gut ◽  
Gram Negative ◽  
Human Gut Microbiota ◽  
Molecular Studies

In vitro study of the interaction between human gut microbiota and herbal extracts using willow bark extract as an example

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
EM Pferschy-Wenzig ◽  
K Koskinen ◽  
C Moissl-Eichinger ◽  
R Bauer
Keyword(s):  
Gut Microbiota ◽  
In Vitro Study ◽  
Vitro Study ◽  
Bark Extract ◽  
Herbal Extracts ◽  
Human Gut ◽  
Human Gut Microbiota ◽  
Willow Bark

Metabolization of the herbal combination STW-5 by human gut microbiota in vitro

2017 ◽  
Author(s):  
EM Pferschy-Wenzig ◽  
A Roßmann ◽  
K Koskinen ◽  
H Abdel-Aziz ◽  
C Moissl-Eichinger ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Human Gut ◽  
Human Gut Microbiota

Substrate use prioritization by a coculture of five species of gut bacteria fed mixtures of arabinoxylan, xyloglucan, β-glucan, and pectin

2020 ◽  
Author(s):  
Y Liu ◽  
AL Heath ◽  
B Galland ◽  
N Rehrer ◽  
L Drummond ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Dietary Fiber ◽  
Plant Cell Wall ◽  
Bacterial Species ◽  
Short Chain ◽  
Emergent Properties ◽  
Human Gut ◽  
Fermentation Products ◽  
Plant Polysaccharides ◽  
Human Gut Microbiota

© 2020 American Society for Microbiology. Dietary fiber provides growth substrates for bacterial species that belong to the colonic microbiota of humans. The microbiota degrades and ferments substrates, producing characteristic short-chain fatty acid profiles. Dietary fiber contains plant cell wall-associated polysaccharides (hemicelluloses and pectins) that are chemically diverse in composition and structure. Thus, depending on plant sources, dietary fiber daily presents the microbiota with mixtures of plant polysaccharides of various types and complexity. We studied the extent and preferential order in which mixtures of plant polysaccharides (arabinoxylan, xyloglucan, β-glucan, and pectin) were utilized by a coculture of five bacterial species (Bacteroides ovatus, Bifidobacterium longum subspecies longum, Megasphaera elsdenii, Ruminococcus gnavus, and Veillonella parvula). These species are members of the human gut microbiota and have the biochemical capacity, collectively, to degrade and ferment the polysaccharides and produce short-chain fatty acids (SCFAs). B. ovatus utilized glycans in the order β-glucan, pectin, xyloglucan, and arabinoxylan, whereas B. longum subsp. longum utilization was in the order arabinoxylan, arabinan, pectin, and β-glucan. Propionate, as a proportion of total SCFAs, was augmented when polysaccharide mixtures contained galactan, resulting in greater succinate production by B. ovatus and conversion of succinate to propionate by V. parvula. Overall, we derived a synthetic ecological community that carries out SCFA production by the common pathways used by bacterial species for this purpose. Systems like this might be used to predict changes to the emergent properties of the gut ecosystem when diet is altered, with the aim of beneficially affecting human physiology. This study addresses the question as to how bacterial species, characteristic of the human gut microbiota, collectively utilize mixtures of plant polysaccharides such as are found in dietary fiber. Five bacterial species with the capacity to degrade polymers and/or produce acidic fermentation products detectable in human feces were used in the experiments. The bacteria showed preferential use of certain polysaccharides over others for growth, and this influenced their fermentation output qualitatively. These kinds of studies are essential in developing concepts of how the gut microbial community shares habitat resources, directly and indirectly, when presented with mixtures of polysaccharides that are found in human diets. The concepts are required in planning dietary interventions that might correct imbalances in the functioning of the human microbiota so as to support measures to reduce metabolic conditions such as obesity.

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