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BRIEF RESEARCH REPORT article

Front. Mar. Sci.
Sec. Marine Megafauna
Volume 11 - 2024 | doi: 10.3389/fmars.2024.1484944

Klebsiella pneumoniae in Stranded California Sea Lions (Zalophus californianus) of Central California Between 2017-2022

Provisionally accepted
Sydney Nicole Zotto Sydney Nicole Zotto 1*Robin C Dunkin Robin C Dunkin 2Juliana D Limon Juliana D Limon 2Maia S Smith Maia S Smith 2Lisabet M Hortensius Lisabet M Hortensius 3Margaret E. Martinez Margaret E. Martinez 3Pádraig Joseph Duignan Pádraig Joseph Duignan 3Cara Field Cara Field 3Esteban Soto Esteban Soto 4Dane Whitaker Dane Whitaker 4Carlos Rios Carlos Rios 3Maurice Byukusenge Maurice Byukusenge 5Bhushan Jayarao Bhushan Jayarao 5Suresh V. Kuchipudi Suresh V. Kuchipudi 6Amy Carr Kinsley Amy Carr Kinsley 1
  • 1 University of Minnesota Twin Cities, St. Paul, United States
  • 2 Joseph M. Long Marine Laboratory, Institute of Marine Sciences, Division of Physical & Biological Sciences, University of California, Santa Cruz, Santa Cruz, California, United States
  • 3 Marine Mammal Center, Sausalito, California, United States
  • 4 University of California, Davis, Davis, California, United States
  • 5 The Pennsylvania State University (PSU), University Park, Pennsylvania, United States
  • 6 University of Pittsburgh, Pittsburgh, Pennsylvania, United States

The final, formatted version of the article will be published soon.

    Klebsiella pneumoniae is a Gram-negative, facultative anaerobic, and non-motile bacillus frequently observed in mammals. A hypermucoviscous (HMV) phenotype of K. pneumoniae is reported in stranded California sea lions (CSL) causing pleuritis and bronchopneumonia as a persistent cause of strandings. We describe an increase in cases of HMV and non-HMV K. pneumoniae in stranded CSLs along the California coast between 2017 to 2022. 2,146 live-stranded CSLs were rescued by The Marine Mammal Center (Sausalito, California). 47 of these tested positive for K. pneumoniae, with a rise in annual incidence from 0.92% (3/331) in 2017 to 8.5% (14/165) and 7.2% (23/320) in 2021 and 2022, respectively. Strandings occurred across 965 kilometers along the North-Central California coast from Bodega Bay, Sonoma, to Avila Beach, San Luis Obispo. A similar pattern was observed in beach-cast CSL carcasses by the Long Marine Laboratory (LML) Stranding Network in Santa Cruz, California who had 8 CSLs test positive for K. pneumoniae with an annual incidence rate of 2.0% (1/50) and 10.1% (7/69) in 2021 and 2022, respectively, with no cases reported prior to 2021. We applied whole-genome sequencing (WGS) to 8 isolates obtained by LML in 2022. WGS analysis revealed high nucleotide similarity between any pair of isolates. Multilocus Sequence Typing showed that all isolates belonged to Sequence type 65 and contained the K2 polysaccharide capsule and siderophore aerobactin, which are all characteristics of hypervirulent K. pneumoniae. We discuss possible causes for this trend and a need for research on K. pneumoniae in free-ranging CSLs in California.

    Keywords: Data curation, Formal analysis, investigation, methodology, resources, Software, Writing -review & editing. Bhushan Jayarao: Data curation, Writing -review & editing. Amy Carr Kinsley: Conceptualization

    Received: 22 Aug 2024; Accepted: 20 Dec 2024.

    Copyright: © 2024 Zotto, Dunkin, Limon, Smith, Hortensius, Martinez, Duignan, Field, Soto, Whitaker, Rios, Byukusenge, Jayarao, Kuchipudi and Kinsley. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Sydney Nicole Zotto, University of Minnesota Twin Cities, St. Paul, United States

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.