Isolation, Identification, and Prevalence of Oral Mycoplasmas in North American Pinnipeds

Seal finger is a zoonotic infection that humans acquire from pinnipeds during dissection or handling, or from trauma. This infection is not uncommon among Canadian biologists working with wild pinnipeds. The etiological agent is believed to be mycoplasma bacteria. No comprehensive data on prevalence of oral mycoplasmas in pinnipeds are available. To investigate whether pinnipeds carry oral mycoplasmas, wild (n=148) and captive (n=14) phocids in eastern Canada and pinnipeds (n=38) in a rehabilitation center in California, USA, were sampled from 1996 to 1998. Mycoplasmas were cultured, isolated, and identified using indirect fluorescent antibody tests in a dedicated mycoplasma laboratory, and prevalence by sex, age, age class, and species of seal was determined. A total of 23l mycoplasma isolates were obtained from sampled pinnipeds. In Canadian phocids, Mycoplasma phocicerebrale, Mycoplasma phocae, and Mycoplasma phocirhinis were isolated and identified from wild gray (Halichoerus grypus) and Atlantic harbor (Phoca vitulina concolor) seals, while M. phocicerebrale was isolated from wild hooded (Cystophora cristata) and harp (Pagophilus groenlandicus) seals and from captive gray and harbor seals, including new host and geographic reports. In wild seals, prevalence of M. phocicerebrale was 78% (31/40) in gray, 70% (32/46) in hooded, 44% (11/25) in harbor, and 22% (8/37) in harp seals. In Californian pinnipeds, M. phocicerebrale and M. phocirhinis were isolated and identified from California sea lions (Zalophus californianus), northern elephant (Mirounga angustirostris) seals, and Pacific harbor (Phoca vitulina richardii) seals, also new host and geographic reports. Unidentified Mycoplasma and Ureaplasma spp. were also isolated in wild and captive Canadian and Californian pinnipeds. These new data on the prevalence and identification of oral mycoplasmas in sampled pinnipeds indicate that personnel working with these animals in the field or in captive situations should exercise caution.