There exists a voluminous literature over the last five decades on the biology of the Sea Otter (Enhydra lutris). Some of these reports are on the clinical pathology of these animals but to the authors' knowledge little if any data are available on the host-parasite relationships and immune response to microbial pathogens.

The present progress report represents preliminary data as part of a long-term study on the indigenous microbial flora, host-parasite relationship (particularly bacterial and fungal pathogens) and immune competence of the sea otter in the wild and in captivity.

Experimental Data

A total of 49 otters were restrained off the coast of California for the implantation of transmitters for determining their productivity, migration, and response to environmental parameters. At this time microbial samples were taken with swabs and transported in culturettes for further evaluation in the laboratory at Berkeley. The source of these samples is shown in Table 1. All samples were cultured on a variety of non­selective and selective media and identified by standard techniques.

The organisms identified to-date from the rectal samples are shown in Table 2. As noted a variety of bacteria are represented including Salmonella, Vibrio, and Yersinia spp. The data are not arranged in frequency of isolation per animal or location but simply to show the variety of Genera isolated thus far. The organisms isolated from the nose, throat, sheath, and vagina are shown in Table 3 and from the eye, ear, and teeth in Table 4.

The IgG was isolated using DEAE AFFI-GEL 13LUE and the IgM using Sephycryl 200. Antisera were produced in rabbits after the purity of the immunoglobulins was first determined by immunoelectrophoresis against rabbit anti-whole otter serum. The antisera were then used to prepare single radialimmune diffusion plates. The results are shown in Table 5. The range of values for IgG as noted are somewhat higher than that reported for the Northern Fur Seal and for the dolphin but the IgM was somewhat lower. The data represent only half of the animals' sera available for testing at the present.

Discussion

This preliminary report indicates that otters have as indigenous flora a wide variety of bacteria, some of which are known as pathogens. Because otters have as their diet filter feeders which are known to concentrate pathogens, future studies will concentrate on organisms such as Vibrio parahemollticus and similar pathogens known to exist in shellfish. Studies are in progress on the microbial content of food fed to otters in captivity, the pool waters and serological response of the animals' IgM to specific pathogens to diagnose acute infections.

Table 1. Sea Otter Samples

Sea Otter Food Items Sampled

 Fish

 Squid

 Abalone

 Shrimp

 Clam

 Smelt

Table 2. Presumptive identification of organisms from rectal samples

 Achromobacter sp.

 Actinobacillus sp.

 Alcaligenes sp.

 Candida sp.

 Citrobacter sp.

 Enterobacter agglomerans

 Enterobacter sp.

 Escherichia coli

 Flavobacterium

 Klebsiella oxytoca

 Klebsiella sp.

 Moraxella sp.

 Morganella morganii

 Pasteurella sp.

 Providencia sp.

 Proteus sp.

 Pseudomonas aeruginosa

 Ps. putida

 Ps. Putrefaciens

 Pseudomonas sp.

 Rhodotorula

 Salmonella sp.

 Serratia sp.

 Vibrio alginolyticus

 Vibrio sp.

 Yersinia sp.

Table 3. Presumptive identification of organisms from the nose, throat, sheath, and vaginal swabs

Nose

 Bacilus sp. (or Corynebacterium sp.)

 Enterobacter sp.

 Esclierichia coli

 Flavobacterium sp.

 Klebsiella sp.

 Pasteurella or Yersinia sp.

 Staphylococcus sp.

 Streptococcus sp.

Throat

 Candida sp.

 Citrobacter sp

 Enterobacter agglomerans

 Enterobacter sp

 Flavobacterium sp.

 Klebsiella sp. Micrococcus sp.

 Streptococcus-group D enterococcus

 Streptococcus-group D non-enterococcus

 Streptococcus sp.

 Vibrio sp.

 Yersinia sp.

Sheath

 Escherichia coli

Vaginal

 Escherichia coli

 Flavobacterium sp

 Proteus sp.

 Pseudomonas sp.

 Rhodotorula sp.

 Staphylococcus sp.

 Streptococcus-group D

 Streptococcus sp.

 Streptomyces sp.

Table 4. Presumptive identification of organisms from the eye, ear, and teeth swabs

Eye

 Bacillus sp.

 Escherichia coli

 Morganella morganii

Ear

 Bacillus sp.

 Staphylococcus sp.

Teeth

 Aeromonas sp.

 Flavobacterium sp.

 Providencia sp.

 Pseudomonas aeruginosa

 Streptomyces sp.

Table 5. Base-line levels of immunoglobulins in otters and other marine mammals