Mycobacterium marinum skin infection successfully treated with levofloxacin

Mycobacterium marinum: A Case-Based Narrative Review of Diagnosis and Management

Skin and soft tissue infections caused by non-tuberculous mycobacteria are occurring more frequently in recent years. However, chronic skin and soft tissue lesions present a challenge for clinicians, as the diagnostic work-up and definitive diagnosis require knowledge and available laboratory resources. We present here the case of a 66-year-old male patient who presented with painful abscess-like nodules on his right hand and forearm, which worsened after treatment with an anti-TNF-a agent. The fluid specimen taken from the lesion was positive for mycobacteria according to the acid-fast stain. Mycobacterium marinum was identified, first by next-generation sequencing and finally grown on culture, after eight weeks. Acknowledging the complexity of diagnosing and managing infections by non-tuberculous mycobacteria, and especially Mycobacterium marinum, we provide a review of the current epidemiology, clinical characteristics, diagnosis and management of Mycobacterium marinum infection.

Mycobacterium marinum

Mycobacterium marinum is a well-known pathogenic mycobacterium for skin and soft tissue infections and is associated with fishes and water. Among nontuberculous mycobacteria (NTM), it is the leading cause of extrarespiratory human infections worldwide. In addition, there is a specific scientific interest in M. marinum because of its genetic relatedness to Mycobacterium tuberculosis and because experimental infection of M. marinum in fishes mimics tuberculosis pathogenesis. Microbiological characteristics include the fact that it grows in 7 to 14 days with photochromogenic colonies and is difficult to differentiate from Mycobacterium ulcerans and other mycolactone-producing NTM on a molecular basis. The diagnosis is highly suspected by the mode of infection, which is related to the hobby of fishkeeping, professional handling of marine shells, or swimming in nonchlorinated pools. Clinics distinguished skin and soft tissue lesions (typically sporotrichoid or subacute hand nodules) and lesions disseminated to joint and bone, often related with the local use of corticosteroids. In clinical microbiology, microscopy and culture are often negative because growth requires low temperature (30°C) and several weeks to succeed in primary cultivation. The treatment is not standardized, and no randomized control trials have been done. Therapy is a combination of surgery and antimicrobial agents such as cyclines and rifampin, with successful outcome in most of the skin diseases but less frequently in deep tissue infections. Prevention can be useful with hand protection recommendations for professionals and all persons manipulating fishes or fish tank water and use of alcohol disinfection after contact.

Zoonotic bacteria, antimicrobial use and antimicrobial resistance in ornamental fish: a systematic review of the existing research and survey of aquaculture-allied professionals

Using systematic review methodology, global research reporting the frequency of zoonotic bacterial pathogens, antimicrobial use (AMU) and antimicrobial resistance (AMR) in ornamental fish, and human illness due to exposure to ornamental fish, was examined. A survey was performed to elicit opinions of aquaculture-allied personnel on the frequency of AMU and AMR in ornamental fish. The most commonly reported sporadic human infections were associated withMycobacterium marinum, whileSalmonellaParatyphi B var. Java was implicated in all reported outbreaks.Aeromonasspp. were most frequently investigated (n=10 studies) in 25 studies surveying ornamental fish from various sources. High levels of resistance were reported to amoxicillin, penicillin, tetracycline and oxytetracycline, which was also in agreement with the survey respondents' views. Studies on AMU were not found in our review. Survey respondents reported frequent use of quinolones, followed by tetracyclines, nitrofurans, and aminoglycosides. Recommendations for future surveillance and public education efforts are presented.

Mycobacterium marinum infection of the deep structures of the hand and wrist: 25 years of experience

Mycobacterium marinum infection could have various presentations, from superficial skin infection to deep structure destruction. The prognosis is relatively poor when deep structure is involved as it is more destructive. The prognosis is even worse when operation is required. In the retrospective study of 136 patients who suffered this disease with deep structure involvement, their clinical presentations could be classified into benign and aggressive type. It was found that both types of presentation could be treated conservatively by medication alone. Benign presentations could be treated successfully with chemotherapy alone without complications. Patients with aggressive presentation were usually associated with worse prognosis as there were more complications regardless of the management option. Therefore, the clinical presentation not only had prognostic value but could also guide the treatment plan.

Treatment of Mycobacterium marinum cutaneous infections

Mycobacterium marinum is a non-tuberculous mycobacterium found in non-chlorinated water, with worldwide prevalence. It is the most common atypical Mycobacterium that causes opportunistic infection in humans. It presents as a solitary, red-to-violaceous plaque or nodule with an overlying crust or verrucous surface, or as inflammatory nodules or abscesses, usually in a sporotrichotic type of distribution. Deep infections may also occur. Although diagnosis is confirmed by isolation and identification of the organism in practice diagnosis remains largely presumptive based on clinicohistological features and the response to treatment. Polymerase chain reaction allows the routine early detection of the organism from a biopsy specimen. In the near future, it seems possible that histopathological examination might be greatly assisted by the rapidly improving possibilities with in vivo imaging. There have been many therapeutic modalities used effectively in the treatment of M. marinum infections. Spontaneous remission has also been reported in untreated infections and in immunocompetent hosts. However, there is no proven treatment of choice because M. marinum is naturally multi-drug resistant species and treatment is based primarily on the personal experience and preference of individual investigators, without the benefit of large studies. In superficial cutaneous infections minocycline, clarithromycin, doxycycline and trimethoprim-sulfamethoxazole as monotherapy are effective treatment options, but drug resistance varies and thereby combination therapy usually of two drugs may be required. Ciprofloxacin has shown considerable effectiveness. In cases of severe infections, including those with a sporotrichoid distribution pattern, a combination of rifampicin and ethambutol seems to be the recommended regimen. The use of isoniazid, streptomycin and pyrazinamide as empirical treatment options should be avoided. Surgical treatment is not usually recommended and must be cautiously applied. Cryotherapy, X-ray therapy, electrodesiccation, photodynamic therapy and local hyperthermic therapy have been reported as effective therapeutic alternatives. M. marinum infection should always be included in the differential diagnosis of all cases with poor-healing wounds in upper extremities and a history of exposure to aquariums.

Fish gambler's tenosynovitis caused by Mycobacterium marinum: environmental investigation of a fishing pond in Southern Taiwan

We describe a patient with Mycobacterium marinum tenosynovitis associated with a fish spine injury acquired at a gambling fishing pond in southern Taiwan and identify the source of the infection. M. marinum was isolated from fishing ponds and underground water and wastewater at the site. The isolates shared the same pulsed-field gel electrophoresis pattern as the patient. M. marinum was not detected in 54 samples obtained from 27 fish. Mycobacterium gordonae was isolated from 24 samples collected from the fish. Mycobacterium abscessus was isolated from 3 fish samples (Lateolabrax japonicus 1 and Sciaenops ocellatus 2). M. abscessus and M. gordonae were isolated from all water samples. This investigation provides strong evidence that the predisposing factor for the M. marinum infection was with a fish spine injury acquired at a gambling fishing pond. The source of the infection was the contaminated pond water.

Masquerading Mycobacterium: Plastic surgeon to the rescue

A patient with a Mycobacterium marinum infection of the hand is described. The present case illustrates that M marinum infection may mimic common skin conditions such as eczema, and fungal and parasitic infestations. Key elements in the diagnosis and management of this infection are a high index of suspicion, a detailed history of recreational or occupational exposure to exotic fish, tissue biopsy, wound culture and prompt empirical antibiotic therapy. Once in vitro organism sensitivities are obtained, antibiotic treatment may last for up to 24 months. Surgical drainage and debridement are an important supplement to antimicrobial therapy when subcutaneous structures are involved, as in the present report. Invasive digital and hand infections can rapidly result in permanent residual stiffness, deformity and loss of function; therefore, it is important to raise awareness of the condition among those considered to be at risk.

Mycobacterium marinum hand infection: case reports and review of literature

Three patients with Mycobacterium marinum infection are described. Key elements in the diagnosis of this infection are a high index of suspicion, taking a history with an emphasis on exposure to tropical fish or other potential sources of M. marinum infection, and tissue biopsy for culture and histology. The microbiologist should be informed about the suspicion of M. marinum infection so that appropriate cultures can be performed. As M. marinum does not grow under routine culture conditions, the diagnosis is easily missed resulting in delayed treatment. The treatment is essentially antimicrobial therapy for the superficial lesions supplemented by an appropriate surgical debridement especially when deep structures are involved.

Mycobacterium marinum infections

Mycobacterium marinum is a saprophytic mycobacteria capable of causing soft tissue infection in humans, usually acquired by inoculation. As with other mycobacterial infections, diagnosis may be difficult and recent developments in molecular biology are also being applied to atypical mycobacteria such as Mycobacterium marinum.