Document Type

Master's Research

Degree Name

Master of Science

Department

Biology

Advisor(s)

Frank V. Paladino, Tanya T. Soule

Date of Award

8-2012

Abstract

The microorganisms associated with olive ridley nesting and potential antimicrobial properties of cloacal fluid were studied at Parque Nacional Marino las Baulas, Costa Rica, and nearby beaches during the 2010-2011 and 2011-2012 seasons. During the first season, bacteria and fungi were isolated and identified from frozen nest chamber sand, cloacal fluid, and unhatched egg samples. This first season, fungi were isolated from cloacal fluid samples, but bacteria were not, however, bacteria and fungi were both isolated from sand and unhatched egg samples. Enterobacter cloacae and Pseudomonas aeruginosa were the most common unhatched egg bacterial isolates. All fungal genera isolated from unhatched eggs had been isolated in previous studies, but this was the first study were Cladosporium was isolated from olive ridley egg chamber sand, and were Aspergillus, Cladosporium, Penicillium¸ and Geotrichum were isolated from olive ridley cloacal fluid. Prior to this study, Geotrichum had not been associated with nesting sea turtles. The second season, samples were not frozen to determine if cloacal fluid contains bacteria, which may have been lost due to freezing the first season, and to identify any potential sand bacterial contaminants in the cloacal fluid. These unfrozen cloacal fluid samples contained Corynebacterium sp., Bacillus sp., Klebsiella sp., as well as genera documented in previous studies. Citrobacter freundii and Serratia odorifera were common in both the cloacal fluid and nest chamber sand samples on all beaches, thus may be potential sand contaminants of cloacal fluid. Kirby-Bauer disk diffusion assays could not detect antimicrobial properties of cloacal fluid against E. cloacae, P. aeruginosa, and Staphylococcus aureus control strains for both olive ridleys and a few opportunistically sampled Eastern Pacific green turtles (Chelonia mydas agassizii). While we cannot say cloacal fluid antimicrobial properties are absent against our test organisms, it is clear they are neither abundant nor widespread in these nesting populations.

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