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

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

doi:10.3390/antibiotics10080980

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 Hawaiʻi, Hawaiʻi, are a potential health risk. Samples were collected from three regions on Hawaiʻi 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 Hawaiʻi. This may be a public health hazard.

Highlights

Previous studies have shown a higher prevalence of Methicillinresistant Staphylococcus aureus (MRSA) infections in the State of Hawai‘i compared to the national average [18,19]
MRSA was not detected in waters at river/stream stations
The MRSA in this study were the typical USA300 strains, which are likely circulating in the community

Summary

Introduction

Staphylococcus aureus is a facultative pathogen that can be part of the normal flora of humans, as well as some animal species. They have been found in domestic and wild animals, as well as in a variety of environments [1,2,3,4,5,6]. Methicillinresistant Staphylococcus aureus (MRSA)- and methicillin-susceptible S. aureus (MSSA)-related mortality rates have been estimated at 14 and 11 deaths per 100,000 hospitalizations, respectively, in the United States [17]. Previous studies have shown a higher prevalence of MRSA infections in the State of Hawai‘i compared to the national average [18,19].

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