Triclosan Resistance in a Bacterial Fish Pathogen, Aeromonas salmonicida subsp. salmonicida, is Mediated by an Enoyl Reductase, FabV

Khan, Raees; Lee, Myung Hwan; Joo, Hae Jin; Jung, Yong Hoon; Ahmad, Shabir; Choi, Jin Hee; Lee, Seon-Woo

doi:10.4014/jmb.1407.07021

“…It is possible that these microbes encode triclosan resistance genes or that they constantly are replenished via environmental exposure (i.e., their water). Indeed triclosan resistant mutants carrying the FabV gene have been described for members of the family Aeromonadaceae [60]. Taken together these results indicate that the zebrafish gut harbors microbes both resistant and susceptible to triclosan exposure and that triclosan exposure is associated with altered abundance of specific taxa in this compartment.…”

Section: Resultsmentioning

confidence: 76%

Triclosan Exposure is Associated with Rapid Restructuring of the Microbiome in Adult Zebrafish

Gaulke

¹

,

Barton

²

,

Proffitt

³

et al. 2016

Preprint

View full text Add to dashboard Cite

Growing evidence indicates that disrupting the microbial community that comprises the intestinal tract, known as the gut microbiome, can contribute to the development or severity of disease. As a result, it is important to discern the agents responsible for microbiome disruption. While animals are frequently exposed to a diverse array of environmental chemicals, little is known about their effects on gut microbiome stability and structure. Here, we demonstrate how zebrafish can be used to glean insight into the effects of environmental chemical exposure on the structure and ecological dynamics of the gut microbiome. Specifically, we exposed forty-five adult zebrafish to triclosan-laden food for four or seven days or a control diet, and analyzed their microbial communities using 16S rRNA amplicon sequencing. Triclosan exposure was associated with rapid shifts in microbiome structure and diversity. We find evidence that several operational taxonomic units (OTUs) associated with the family Enterobacteriaceae appear to be susceptible to triclosan exposure, while OTUs associated with the genus Pseudomonas appeared to be more resilient and resistant to exposure. We also found that triclosan exposure is associated with topological alterations to microbial interaction networks and results in an overall increase in the number of negative interactions per microbe in these networks. Together these data indicate that triclosan exposure results in altered composition and ecological dynamics of microbial communities in the gut. Our work demonstrates that because zebrafish afford rapid and inexpensive interrogation of a large number of individuals, it is a useful experimental system for the discovery of the gut microbiome's interaction with environmental chemicals.

show abstract

“…Examination of the phylotype analysis confirmed that these taxa were unchanged during exposure. Concordantly, triclosan resistant mutants carrying the FabV gene have been described for members of the family Aeromonadaceae [ 60 ]. Taken together these results indicate that the zebrafish gut harbors microbes both resistant and susceptible to triclosan exposure and that triclosan exposure is associated with altered abundance of specific taxa in this compartment.…”

Section: Resultsmentioning

confidence: 99%

Triclosan Exposure Is Associated with Rapid Restructuring of the Microbiome in Adult Zebrafish

Gaulke

¹

,

Barton

²

,

Proffitt

³

et al. 2016

View full text Add to dashboard Cite

Growing evidence indicates that disrupting the microbial community that comprises the intestinal tract, known as the gut microbiome, can contribute to the development or severity of disease. As a result, it is important to discern the agents responsible for microbiome disruption. While animals are frequently exposed to a diverse array of environmental chemicals, little is known about their effects on gut microbiome stability and structure. Here, we demonstrate how zebrafish can be used to glean insight into the effects of environmental chemical exposure on the structure and ecological dynamics of the gut microbiome. Specifically, we exposed forty-five adult zebrafish to triclosan-laden food for four or seven days or a control diet, and analyzed their microbial communities using 16S rRNA amplicon sequencing. Triclosan exposure was associated with rapid shifts in microbiome structure and diversity. We find evidence that several operational taxonomic units (OTUs) associated with the family Enterobacteriaceae appear to be susceptible to triclosan exposure, while OTUs associated with the genus Pseudomonas appeared to be more resilient and resistant to exposure. We also found that triclosan exposure is associated with topological alterations to microbial interaction networks and results in an overall increase in the number of negative interactions per microbe in these networks. Together these data indicate that triclosan exposure results in altered composition and ecological dynamics of microbial communities in the gut. Our work demonstrates that because zebrafish afford rapid and inexpensive interrogation of a large number of individuals, it is a useful experimental system for the discovery of the gut microbiome’s interaction with environmental chemicals.

show abstract

“…salmonicida harbors a TCS R FabV ENR homolog with high identity with ENRs in other fish pathogens, including Edwardsiella spp., Vibrio spp., and Flavobacterium spp. [40]. Our functional work suggests that TCS R FabV homologs may be ubiquitous in Aeromonas spp.…”

Section: Discussionmentioning

confidence: 89%

Functional screening for triclosan resistance in a wastewater metagenome and isolates of Escherichia coli and Enterococcus spp. from a large Canadian healthcare region

Cameron

¹

,

Barbieri²,

Read

³

et al. 2019

View full text Add to dashboard Cite

The biocide triclosan is in many consumer products and is a frequent contaminant of wastewater (WW) such that there is concern that triclosan promotes resistance to important antibiotics. This study identified functional mechanisms of triclosan resistance (TCSR) in WW metagenomes, and assessed the frequency of TCSR in WW-derived and clinical isolates of Escherichia coli and Enterococcus spp. Metagenomic DNA extracted from WW was used to profile the microbiome and construct large-insert cosmid libraries, which were screened for TCSR. Resistant cosmids were sequenced and the TCSR determinant identified by transposon mutagenesis. Wastewater Enterococcus spp. (N = 94) and E. coli (N = 99) and clinical Enterococcus spp. (N = 146) and vancomycin-resistant E. faecium (VRE; N = 149) were collected and tested for resistance to triclosan and a comprehensive drug panel. Functional metagenomic screening revealed diverse FabV homologs as major WW TCSR determinants. Resistant clones harboured sequences likely originating from Aeromonas spp., a common WW microbe. The triclosan MIC90s for E. coli, E. faecalis, and E. faecium isolates were 0.125, 32, and 32 mg/L, respectively. For E. coli, there was no correlation between the triclosan MIC and any drug tested. Negative correlations were detected between the triclosan MIC and levofloxacin resistance for E. faecalis, and between triclosan and vancomycin, teicoplanin, and ampicillin resistance for E. faecium. Thus, FabV homologs were the major contributor to the WW triclosan resistome and high-level TCSR was not observed in WW or clinical isolates. Elevated triclosan MICs were not positively correlated with antimicrobial resistance to any drug tested.

show abstract

Triclosan Resistance in a Bacterial Fish Pathogen, Aeromonas salmonicida subsp. salmonicida, is Mediated by an Enoyl Reductase, FabV

Cited by 8 publications

References 40 publications

Triclosan Exposure is Associated with Rapid Restructuring of the Microbiome in Adult Zebrafish

Triclosan Exposure is Associated with Rapid Restructuring of the Microbiome in Adult Zebrafish

Triclosan Exposure Is Associated with Rapid Restructuring of the Microbiome in Adult Zebrafish

Functional screening for triclosan resistance in a wastewater metagenome and isolates of Escherichia coli and Enterococcus spp. from a large Canadian healthcare region

Contact Info

Product

Resources

About