Environmental Surveillance and Characterization of Antibiotic Resistant Staphylococcus aureus at Coastal Beaches and Rivers on the Island of Hawai'i

Tyler J Gerken; Marilyn C Roberts; Philip Dykema; Geoff Melly; Darren Lucas; Vanessa De Los Santos; Joenice Gonzalez; Patrick Butaye; Tracy N Wiegner

doi:10.3390/antibiotics10080980

Environmental Surveillance and Characterization of Antibiotic Resistant Staphylococcus aureus at Coastal Beaches and Rivers on the Island of Hawai'i

Antibiotics (Basel). 2021 Aug 13;10(8):980. doi: 10.3390/antibiotics10080980.

Authors

Tyler J Gerken¹, Marilyn C Roberts¹, Philip Dykema², Geoff Melly², Darren Lucas², Vanessa De Los Santos², Joenice Gonzalez², Patrick Butaye^{3

4}, Tracy N Wiegner⁵

Affiliations

¹ Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA 98105, USA.
² Washington State Department of Health, Shoreline, WA 98155, USA.
³ Ross University School of Veterinary Medicine, Basseterre 42123, Saint Kitts and Nevis.
⁴ Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium.
⁵ Marine Science Department, University of Hawai'i at Hilo, Hilo, HI 96720, USA.

Abstract

Staphylococcus aureus are human facultative pathogenic bacteria and can be found as contaminants in the environment. The aim of our study was to determine whether methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) isolated from coastal beach and river waters, anchialine pools, sand, and wastewater on the island of Hawai'i, Hawai'i, are a potential health risk. Samples were collected from three regions on Hawai'i Island from July to December 2020 during the COVID-19 pandemic and were characterized using whole-genome sequencing (WGS). From WGS data, multilocus sequence typing (MLST), SCCmec type, antimicrobial resistance genes, virulence factors, and plasmids were identified. Of the 361 samples, 98.1% were positive for Staphylococcus spp. and 7.2% were S. aureus positive (n = 26); nine MRSA and 27 MSSA strains were characterized; multiple isolates were chosen from the same sample in two sand and seven coastal beach water samples. The nine MRSA isolates were multi-drug resistant (6-9 genes) sequence type (ST) 8, clonal complex (CC) 8, SCCmec type IVa (USA300 clone), and were clonally related (0-16 SNP differences), and carried 16-19 virulence factors. The 27 MSSA isolates were grouped into eight CCs and 12 STs. Seventy-eight percent of the MSSA isolates carried 1-5 different antibiotic resistance genes and carried 5-19 virulence factors. We found S. aureus in coastal beach and river waters, anchialine pools, and sand at locations with limited human activity on the island of Hawai'i. This may be a public health hazard.

Keywords: MRSA; MSSA; Staphylococcus aureus; USA300; antimicrobial resistance; beaches; rivers; sequence types; virulence factors; whole-genome sequencing.