Patterns of triclosan resistance in Vibrionaceae

Abstract

The antimicrobial additive triclosan has been used in personal care products widely across the globe for decades. Triclosan resistance has been noted among Vibrio spp., but reports have been anecdotal and the extent of phenotypic triclosan resistance across the Vibrionaceae family has not been established. Here, triclosan resistance was determined for Vibrionaceae strains across nine distinct clades. Minimum inhibitory concentrations (MIC) were determined for 70 isolates from clinical (n = 6) and environmental sources (n = 64); only two were susceptible to triclosan. The mean MIC for all resistant Vibrionaceae was 53 µg mL−1 (range 3.1–550 µg mL−1), but was significantly different between clades (p < 0.001). The highest mean triclosan MIC was observed in the Splendidus clade (200 µg mL−1; n = 3). Triclosan mean MICs were 68.8 µg mL−1 in the Damselae clade and 45.3 µg mL−1 in the Harveyi clade. The lowest mean MIC was observed in the Cholerae clade with 14.4 µg mL−1, which was primarily represented by clinical strains. There were no significant differences in triclosan MIC among individual species or among environmental strains isolated from different locations. Overall, phenotypic triclosan resistance appears to be widespread across multiple clades of Vibrionaceae.

Comprehensive insight into triclosan—from widespread occurrence to health outcomes

“…Based on the reported values given in Table 1 , TCS concentrations in surface water were several times higher than the predicted no observed effect concentration (PNEC) of TCS set by European Commission (0.069 nM). Hence, the current prioritization methodology of TCS is questionable due to the growing resistance of the vast groups of bacteria and the demonstrated TCS toxicity toward different aquatic organisms at the environmental levels (Khatikarn et al 2018 ; Lydon et al 2018 ; Westfall et al 2019 ).…”

Draft genome sequence of multidrug-resistant Vibrio navarrensis strain DA9 isolated from a coastal canal in the Florida Keys (USA)

“…In August 2014, a sucrose fermentation-positive presumptive Vibrio isolate (strain DA9) was isolated from surface seawater in a coastal canal (24.700389, –81.352000) in the Florida Keys (USA) after growth on thiosulfate-citrate-bile salts-sucrose (TCBS) agar plates at 30°C overnight ( 9 ). Further characterization of strain DA9 through hsp60 sequencing ( 10 ) revealed that it was closely related to V. vulnificus (84.6% nucleotide identity) and subjected to further investigation through antibiotic resistance screening and whole-genome sequencing.…”