Contamination of automated teller machines surfaces with multi-drug resistance, including esbl and quinolone-resistant gram-negative bacteria in dar es salaam, tanzania

Abstract

Background: Commonly touched public surfaces such as Automated Teller Machines (ATMs) are reported to be contaminated with a variety of pathogenic bacteria including multi-drug resistant (MDR) gram-negative bacteria, with potential for transmission of such dangerous microorganisms among users. In Tanzania little is known about the proportion of MDR gram-negative bacteria contaminated on ATMs, associated factors, and antimicrobial resistance patterns. This study aimed to determine the proportion of MDR gram-negative bacteria contaminated on ATM surfaces, associated factors, and antimicrobial resistance patterns in Dar es salaam, Tanzania. Methodology: This was a cross-sectional study, conducted between January and March -2021 at Dar es Salaam. A total of 298 ATMs from NMB, NBC, and CRDB banks were studded. Observation checklist was used to collect information. Sterile cotton swabs were used to collect samples from the mostly touched ATM Metallic keypads/screen, placed in nutrient broth. Samples were cultured on Mac-Conkey agar, and antimicrobial susceptibility was done using the Kirby Bauer disc diffusion method as per the CLSI guideline. K. pneumoniae ATCC 700603 and E. coli ATCC 25922 were standard organisms used as control. ESBL production was done using the combination disk method and MDR was identified when bacteria were resistant to three or more antimicrobial classes. Chi-square and modified poisson regression were performed to show factors associated with MDR contamination. P-value <0.05 was considered statistical significance Results˸ More than half (55.4%) of ATMs in Dar es Salaam are contaminated with gram negative bacteria. K. pneumoniae was the most predominant bacteria, 18.5% (31/168). The highest level of resistance was observed against ampicillin (68.9%). About one-third 34.5% (58/168) of the isolates were MDR. ESBL produces were 14.1%(10/71) and more significantly resistant to meropenem (30%), while quinolone resistant isolates were 19.6%(33/168) and were more resistant to ampicillin (54.8%), trimethoprim/ sulfamethoxazole (37.1%), and meropenem (20.9%). Risk factors for contamination of ATMs included location at Ubungo (PR adj = 3.62, 95%CI = 1.58-8.30, P=0.002), Kigamboni (PR adj = 2.78, 95%CI = 1.20-6.42, P=0.017), and Temeke (PR adj = 2.75, 95%CI = 1.04-3.72, P=0.023), and less frequent cleaning (PR adj = 1.98, 95%CI = 1.04-3.73, P=0.04) Conclusions: More tha half of ATMs in Dar es Salaam are contaminated with gram-negative bacteria including multi-drug resistant, especially those located in highly populated areas and the less frequently cleaned ones. These findings indicate the potential role of ATMs in Dar es Salaam in spreading multi-drug resistant bacteria that can cause infections that are difficult to treat, which should alert customers and owners of these machines. Clear instructions are urgently needed regarding disinfection of the machines and clients’ precautionary measures, mainly hand sanitation. Keywords: Multi-drug resistance, Gram-negative bacteria, Automated Teller Machine (ATM), Extended-Spectrum Beta-Lactamases (ESBL), Quinolone/ flouraquinolone-resistant.