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Updated: Aug 8, 2026
Optimized PCR-based Detection of Mycoplasma
Published on: June 20, 2011
Isolation of Mycoplasma species from a patient with seal finger
Abstract:
The etiologic agent of seal finger (speck finger) is unknown. Seal finger occurs after a seal bite, and the symptoms include acute pain, swelling, discharge, and, in some cases, there is joint involvement. The discovery of Mycoplasma species in epidemics of seal disease prompted attempts to link seal finger to mycoplasma. Mycoplasma species were isolated in cultures of a specimen from the finger of an aquarium trainer who was bitten by a seal and of a specimen from the front teeth of the biting seal. The two Mycoplasma isolates were identical biochemically; they were serum-dependent and hydrolyzed arginine. The isolates were susceptible to tetracycline but resistant to erythromycin. By growth inhibition and immunofluorescent antibody tests, both strains were identified as Mycoplasma phocacerebrale, a mycoplasma isolated in an epidemic of seal disease occurring in the Baltic Sea. The patient's infection was treated successfully with tetracycline. To our knowledge, this is the first case in which a mycoplasma has been associated with seal finger.
Insights
Seal finger, a condition following a seal bite, is now linked to Mycoplasma phocacerebrale. This discovery offers new insights into the bacterial cause of this painful human infection.
Area of Science:
- Infectious Diseases
- Microbiology
- Dermatology
Background:
- Seal finger (speck finger) is a painful condition following a seal bite with unknown etiology.
- Symptoms include pain, swelling, discharge, and potential joint involvement.
Observation:
- Mycoplasma species were investigated due to their presence in seal disease epidemics.
- Mycoplasma was isolated from an infected aquarium trainer and the biting seal.
Findings:
- Biochemical analysis confirmed the isolates were identical, serum-dependent, and arginine-hydrolyzing.
- Growth inhibition and immunofluorescent antibody tests identified the strains as Mycoplasma phocacerebrale.
- The patient's infection responded successfully to tetracycline treatment.
Implications:
- This is the first documented association of Mycoplasma with seal finger.
- Identifies Mycoplasma phocacerebrale as a potential causative agent of seal finger.
- Suggests tetracycline as an effective treatment for seal finger infections.
