Microbial contamination of main contact surfaces of Automated Teller Machines from Metropolitan Area of Porto

ABSTRACT

Automated Teller Machines (ATM) are likely to be contaminated with various microorganisms because of their contact with the hands of many users daily. The main objective of this study was to investigate ATMs as a potential source of bacterial contamination. This study was conducted in the Metropolitan Area of Porto, in which 50 swab samples were cultured on selective media. Some isolates were identified based on colonial, morphological and biochemical characteristics. Susceptibility to several antibiotics was also evaluated for each isolated organism. Most contaminated ATMs had high numbers of Enterobacteriaceae and Enterococci. Staphylococci and Enterobacteriaceae were the most prevalent bacteria found. The recovered bacterial isolates varied in their antibiotic resistance pattern; Staphylococcus spp. demonstrated the most resistant profiles. With this pioneering study in Portugal, it was demonstrated that although ATMs in metropolitan area of Porto were not highly contaminated, some potentially pathogenic bacteria were present and resistant to some commonly used antibiotics.

KEYWORDS:

• Antibiotic resistance
• ATM
• Microbial contamination

Acknowledgments

This work was supported through project ‘Biological tools for adding and defending value in key agro-food chains (bio—n2—value)’, No. NORTE-01-0145-FEDER-000030, funded by Fundo Europeu de Desenvolvimento Regional (FEDER), under Programa Operacional Regional do Norte—Norte2020”. We would also like to thank the scientific collaboration under the Fundação para a Ciência e a Tecnologia (FCT) project UID/Multi/50016/2019. Financial support for author J. Barbosa was provided by a post-doctoral fellowship SFRH/BPD/113303/2015 (FCT). The authors express their gratitude to the editor Dr Michael Brett-Crowther for his valuable comments to improve this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.