Plastics and Microplastics as Vectors for Bacteria and Human Pathogens

<p>Since plastics degrade very slowly, they remain in the environment on much longer timescales than most natural substrates and can thus provide a novel habitat for colonization by bacterial communities. The full spectrum of relationships between plastics and bacteria, however, is little understood. The objective of this study was to examine marine plastic pollution as a substrate for bacteria, with particular focus on<em> Vibrio spp</em>., including the human pathogens, <em>Vibrio cholerae</em>, <em>Vibrio parahaemolyticus</em>, and <em>Vibrio vulnificus</em>.</p> <p>Colonization experiments were set up in a tributary of the lower Chesapeake Bay to follow <em>Vibrio spp</em>. colonization and total bacterial community composition over time. Microplastics and paired seawater samples were also collected and examined for the presence and abundance of <em>Vibrio spp</em>. In many instances, vibrios were enriched on plastics by at least two orders of magnitude compared to paired seawater samples. Antibiotic-resistance profiles for <em>Vibrio spp</em>. isolates revealed no differences between the antibiotic susceptibilities of vibrios isolated from plastics compared to those from the surrounding water column. There was, however, a significant difference in antibiotic susceptibility between isolates from colonization experiments and microplastics, with more resistance overall seen in the former.</p> <p>Bacterial colonization on plastics was detected with DNA sequencing as early as day two and communities on plastic were consistently distinct and more diverse than surrounding seawater. Fifteen different bacterial classes were found in water and biofilms and 171 genera were identified. Among all samples, <em>Gammaproteobacteria</em> (30%) constituted the majority of the total sequences with the next most retrieved bacterial classes being <em>Bacteroidetes</em> (28%) and <em>Alphaproteobacteria</em> (20%). Colonization rates and community structure varied temporally and among substrate types, suggesting that numerous factors should be considered when characterizing microbial communities on plastic. This is the first study to culture <em>V. cholerae, V. parahaemolyticus</em>, and <em>V. vulnificus</em> from marine plastics, demonstrates that plastic pollution serves as a habitat for <em>Vibrio</em> species, and confirms the conjecture of Zettler et al. (2013) that plastics may serve as a vector for these and other potentially pathogenic bacteria.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Ocean & Earth Sciences

Year dc:date.available

2018

Author dc:creator

• Laverty, Amanda Lee

Contributors dc:contributor

• Fred C. Dobbs
• P. Dreux Chappell
• Dayle Daines

• Bacteria
• Biofilm
• Human pathogens
• Microplastics
• Plastics
• Vibrio
• Microbiology
• Oceanography

Statement dc:rights

• <p>In Copyright. URI: <a href="http://rightsstatements.org/vocab/InC/1.0/">http://rightsstatements.org/vocab/InC/1.0/</a> This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).</p>

Identifier

9780438455948

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:oeas_etds-1013