Zinc can counteract selection for ciprofloxacin resistance

Abstract

Phone: (+44)7497497338 21 ORCID: 0000-0002-4169-6548 22 Graphical abstract 23 24One sentence summary 25The minimal selective concentration for a ciprofloxacin resistant E. coli strain increases up to 26 5-fold in the presence of Zinc cations. 27 3 Abstract 28 Antimicrobial resistance (AMR) has emerged as one of the most pressing global threats to 29 public health. AMR evolution occurs in the clinic but also in the environment, where low 30 concentrations of antibiotics and heavy metals can respectively select and co-select for 31 resistance. While the selective potential for AMR of both antibiotics and metals is 32 increasingly well-characterized, studies exploring the combined effect of both types of 33 selective agents are rare. It has previously been demonstrated that fluoroquinolone 34 antibiotics such as ciprofloxacin can chelate metal ions. To investigate how ciprofloxacin 35 resistance is affected by the presence of metals, we quantified selection dynamics between 36 a ciprofloxacin-susceptible and an isogenic ciprofloxacin-resistant Escherichia coli MG1655 37 strain across a gradient of ciprofloxacin concentrations in the presence and absence of Zinc 38 cations (Zn 2+ ). The minimal selective concentration (MSC) for ciprofloxacin resistance 39 significantly increased up to 5-fold in the presence of Zn 2+ . No such effect on the MSC was 40 found for gentamicin, an antibiotic not known to chelate zinc cations. Environmental pollution 41 usually consists of complex mixtures of antimicrobial agents. Our findings highlight the 42 importance of taking antagonistic as well as additive or synergistic interactions between 43 different chemical compounds into account when considering their effect on bacterial 44 resistance evolution. 45

A Model to Investigate the Impact of Farm Practice on Antimicrobial Resistance in UK Dairy Farms

“…Another farm practice factor which requires more investigation is the effect of heavy metal co-resistance on bacterial populations in slurry, given the widespread use of copper and zinc footbaths in the UK (Pal et al 2017;Williams et al 2019). Though it is well known that metals can contribute to the development and spread of AMR, it has also been shown that heavy metals can impede selection for resistance, in the case of ciprofloxacin and zinc (Vos et al 2019). A future model could consider cases in which heavy metals both contribute and detract from the development of AMR.…”

The effect of metal remediation on the virulence and antimicrobial resistance of the opportunistic pathogen Pseudomonas aeruginosa

“…Water and sediment samples were collected from the metal-contaminated Carnon River in Cornwall, U.K. (50°13’54.6’ N, 5°07’48.7’ W) (53). We chose this site as it is polluted by multiple toxic metals (18, 50) and liming has been shown to reduce total non-ferrous metal availability in samples collected in the near vicinity (18). The water sample in reference (50) was taken at the same time as the samples used in this study, and contains high concentrations of non-ferrous metals.…”

“…We chose this site as it is polluted by multiple toxic metals (18, 50) and liming has been shown to reduce total non-ferrous metal availability in samples collected in the near vicinity (18). The water sample in reference (50) was taken at the same time as the samples used in this study, and contains high concentrations of non-ferrous metals. Sediment was collected using a sterile spatula and water was collected by filling a sterile 1000 mL duran bottle (Schott Duran, Munich, Germany).…”

Determining the prevalence, identity and possible origin of bacterial pathogens in soil

“…A further seven rhizosphere samples (paired with seven bulk soil samples) were collected by scraping soil from plant roots (<5 cm depth). Finally, we collected seven soil samples from the banks of the Carnon River which runs through a mine heritage site with high levels of heavy metal contamination (Vos et al ., 2019).…”