Dental unit water content and antibiotic resistance of Pseudomonas aeruginosa and Pseudomonas species: a case study

M Tesauro; M Consonni; I Grappasonni; G Lodi; R Mattina

doi:10.1080/20002297.2022.2107316

Dental unit water content and antibiotic resistance of Pseudomonas aeruginosa and Pseudomonas species: a case study

J Oral Microbiol. 2022 Aug 23;14(1):2107316. doi: 10.1080/20002297.2022.2107316. eCollection 2022.

Authors

M Tesauro¹, M Consonni¹, I Grappasonni², G Lodi¹, R Mattina¹

Affiliations

¹ Department of Biomedical, Surgical and Dental Sciences, Laboratory of Environmental Hygiene, Coordinating Research Centres Episomi University of Milan, University of Milan, Milan, Italy.
² School of Medicinal and Health Products Sciences, University of Camerino, Camerino, Italy.

Abstract

Background: Many studies consider the contamination of dental unit waterlines (DUWLs), but few of them have studied the possible presence of antibiotic resistant Pseudomonas aeruginosa in the DUWLs.

Aims: Investigation of the presence of P. aeruginosa and Pseudomonas spp. strains in DUWLs and evaluation of their resistance to six antibiotics (ceftazidime, netilmicin, piperacillin/tazobactam, meropenem, levofloxacin, colistin sulfate) at a public dental clinic in Milan, Italy.

Results: Dental units were contaminated by P. aeruginosa with loads of 2-1,000 CFU/L and were mainly located on the mezzanine floor, with a range of 46-54%, while Pseudomonas spp. were primarily found on the first and second floors, ranging from 50 to 91%. P. aeruginosa was antibiotic resistant in 30% of the strains tested, andPseudomonas spp. in 31.8% . Cold water from controls was also contaminated by these microorganisms.

Conclusion: Monitoring antibiotic resistance in the water and adopting disinfection procedures on DUs are suggested within the Water Safety Plan.

Keywords: Dental unit water line; Pseudomonas aeruginosa; Pseudomonas spp.; antibiotic resistance; water microbiology; water safety plan.

Grants and funding

This work was supported by the Research Support Plan (2018) of the University of Milan; Research Support Plan of the University of Milan 2018.