First report of cross resistance to silver and antibiotics in Klebsiella pneumoniae isolated from patients and polluted water in Tunisia

Abstract

Klebsiella pneumoniae, ubiquitously found in a variety of environmental sources, is an important pathogen in burn wounds and nosocomial infections. Burn wounds have been commonly treated with silver compounds, which are also used in a multitude of (non)medical products. As the latter increased silver discharge into different environments, we evaluated and compared silver resistance in K. pneumoniae isolates collected from patients hospitalized at the Charles‐Nicolle hospital (Tunis, Tunisia) with isolates collected from different metal polluted waters in the north and south of Tunisia. All K. pneumoniae isolates harboured blaTEM‐1 and blaSHV‐1. In addition, all clinical isolates showed a multidrug phenotype and harboured the blaCTX‐M‐15, blaOXA‐1 and blaNDM‐1. Furthermore, all isolates showed resistance to silver nitrate. The silver resistance determinant, screened via the silE gene, was located for all isolates on a large plasmid with a size similar to pMG101. This study showed cross‐resistance between silver and beta‐lactams in clinical as well as environmental K. pneumoniae isolates from Tunisia and showed for the first time that NDM‐1‐producing K. pneumoniae developed resistance to silver.

First Description of Various Bacteria Resistant to Heavy Metals and Antibiotics Isolated from Polluted Sites in Tunisia

“…Substantial reports suggest that heavy metal contamination represents an indirect selection agent that contributes to the maintenance and spread of antibiotic resistance factors ( Baker-Austin et al 2006 ). The silE gene can be harbored on plasmids ( Ben Miloud et al 2020 ) carrying antibiotic resistance genes, and silver can thereby have an indirect selective pressure. Even more directly, silver can select for porin deficiency and consequently mediate a cross-resistance to β-lactams ( Sütterlin et al 2014 ).…”

“…Sampling sites were chosen because of their geographic situation near urban, industrial, and agricultural areas. Sample locations were based on a previous study that determined the degree of pollution (Ben Miloud et al 2020).…”

4-[(E)-2-(1-Pyrenyl)Vinyl]Pyridine Complexes: How to Modulate the Toxicity of Heavy Metal Ions to Target Microbial Infections

“…There are nevertheless two issues concerning the use of metal ions as therapeutic weapons. The first concerns the development of resistance pathways to these ions by some bacteria, generally through (over-)expression of efflux pumps [9], transporters [10,11], or chaperones [10] (for a complete review, see [12]). Secondly, bacteria are not always the only susceptible organisms to metal ions, and some heavy metal ions are toxic to mammalian cells, e.g., cadmium(II), arsenic(III or V), and mercury(II) [13][14][15][16][17].…”