Current treatment options for Mycobacterium marinum cutaneous infections

ABSTRACT

Introduction

Mycobacterium marinum is a slowly growing photochromogenic nontuberculous mycobacterium that has special growth characteristics. It causes a uniquely human disease, a cutaneous syndrome named fish tank granuloma or swimming pool granuloma because of the strong epidemiological links with water. The treatment of this disease involves the use of different antimicrobials alone and in combination, depending on the severity of the disease. The antibiotics most frequently used are macrolides, tetracyclines, cotrimoxazole, quinolones, aminoglycosides, rifamycins, and ethambutol. Other approaches include the use of surgery in some cases. New treatment options, like new antibiotics, phage therapy, phototherapy, and others are currently being developed with good in vitro experimental results. In any case, the disease is usually a mild one, and the outcome is good in most of the treated patients.

Areas covered

We have searched the literature for treatment schemes and drugs used for treatment of M. marinum disease, as well as other therapeutic options.

Expert opinion

Medical treatment is the most recommended approach option, as M. marinum is usually susceptible to tetracyclines, quinolones, macrolides, cotrimoxazole, and some tuberculostatic drugs, usually used in a combined therapeutic scheme. Surgical treatment is an option that can be curative and diagnostic in small lesions.

KEYWORDS:

• Mycobacterium marinum
• skin and soft tissue infection
• treatment
• fish tank granuloma
• surgery
• combined therapy

Article highlights

• M. marinum is a non-tuberculous mycobacterium widely distributed in aquatic environments.

• Patients usually acquire the disease known as ‘fish tank granuloma’ through contact with fish or after cleaning aquariums or swimming pools. Organisms may be introduced into the skin through previous abrasions.

• Most lesions are found on the upper limbs and localized on the skin in the form of granulomas. With rare exceptions, different parts of the body are affected, and the infection may spread via the lymphatic system in a sporotrichoid pattern or affect deep tissues such as bone or lungs.

• Diagnosis is made from biopsy material, histologic examination, and culture. A history of exposure to an aquarium, pool, or fish cleaning is often key to diagnosis.

• Studies show that superficial infections may benefit from clarithromycin or tetracycline monotherapy. For severe infections, the combination of ethambutol and clarithromycin is recommended, with the addition of rifampicin in the case of deep tissue involvement.

• The recommended duration of treatment is 1 to 2 months after the resolution of symptoms, typically 3 to 4 months in total.

• Susceptibility testing is not routinely recommended and should be reserved for cases of treatment failure.

• In some cases of deep infection or failure of antibiotic treatment, surgical debridement should be used.

Acknowledgments

We want to acknowledge Prof. Luis Requena, from the Department of Dermatology at the Fundacion Jimenez Diaz University Hospital for providing us with the clinical and histopathological images (Figure 2).

Declaration of interest

J Esteban reports receiving travel funds by Biomérieux, Pfizer as well as receiving conference fees by Biomérieux, Heraeus. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.