Short communication Detection of Helicobacter and Campylobacter spp. from the aquatic environment of marine mammals C.G. Goldman a, *, M.J. Matteo b , J.D. Loureiro c,d , J. Degrossi e , S. Teves f , S. Rodriguez Heredia c , K. Alvarez c , A. Beltra ´ n Gonza ´ lez a , M. Catalano b , J. Boccio a , G. Cremaschi a , J.V. Solnick g,h , M.B. Zubillaga a a Physics Department, School of Pharmacy and Biochemistry, University of Buenos Aires, Junı´n 956, 1113 Buenos Aires, Argentina b Microbiology, Parasitology and Immunology Department, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina c Mundo Marino Foundation, San Clemente del Tuyu ´, Buenos Aires, Argentina d Mundo Marino Oceanarium, San Clemente del Tuyu ´, Buenos Aires, Argentina e Public Health Laboratory, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina f Microbiology Laboratory, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina g Departments of Medicine and Medical Microbiology & Immunology, University of California, Davis, CA, USA h Center for Comparative Medicine, University of California, Davis, CA, USA ARTICLE INFO Article history: Received 18 March 2008 Received in revised form 17 June 2008 Accepted 26 June 2008 Keywords: Helicobacter Marine mammals Water Otoliths ABSTRACT The mechanism by which Helicobacter species are transmitted remains unclear. To examine the possible role of environmental transmission in marine mammals, we sought the presence of Helicobacter spp. and non-Helicobacter bacteria within the order Campylobacterales in water from the aquatic environment of marine mammals, and in fish otoliths regurgitated by dolphins. Water was collected from six pools, two inhabited by dolphins and four inhabited by seals. Regurgitated otoliths were collected from the bottom of dolphins’ pools. Samples were evaluated by culture, PCR and DNA sequence analysis. Sequences from dolphins’ water and from regurgitated otoliths clustered with 99.8–100% homology with sequences from gastric fluids, dental plaque and saliva from dolphins living in those pools, and with 99.5% homology with H. cetorum. Sequences from seals’ water clustered with 99.5% homology with a sequence amplified from a Northern sea lion (AY203900). Control PCR on source water for the pools and from otoliths dissected from feeder fish were negative. The findings of Helicobacter spp. DNA in the aquatic environment suggests that contaminated water from regurgitated fish otoliths and perhaps other tissues may play a role in Helicobacter transmission among marine mammals. ß 2008 Elsevier B.V. All rights reserved. 1. Introduction In spite of being a widespread infection in humans and animals, the mode by which Helicobacter species are transmitted remains unclear. Oral–oral and fecal–oral modes of transmission have been suggested for human H. pylori infection (Feldman et al., 1998). Contaminated water could be implicated in transmission of the infection (Hulten et al., 1996; Azevedo et al., 2008), although it does not seem to be the main route of transmission (Feldman et al., 1998). Waterborne environmental trans- mission of H. pylori infection might be related to a coccoid form, a viable but non-cultivable bacterial stage that has been widely described for other bacteria in aquatic environments (Byrd et al., 1991; Engstrand, 2001). Oral–oral and fecal–oral routes may also be implicated in transmission of Helicobacter infection in marine mammals, since Helicobacter spp. have been isolated from the feces of dolphins (Harper et al., 2002), and detected in Veterinary Microbiology 133 (2009) 287–291 * Corresponding author. Tel.: +54 11 4964 8202; fax: +54 11 4964 8202x31. E-mail address: cgold@ffyb.uba.ar (C.G. Goldman). Contents lists available at ScienceDirect Veterinary Microbiology journal homepage: www.elsevier.com/locate/vetmic 0378-1135/$ – see front matter ß 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.vetmic.2008.06.023