Identification of Mycobacterium marinum in sea-urchin granulomas

Mycobacteriosis in Aquatic Invertebrates: A Review of Its Emergence

Mycobacteriosis is a chronic bacterial disease reported in aquatic and terrestrial animals, including humans. The disease affects a wide range of cultured and wild organisms worldwide. Mycobacteriosis is well-known in aquatic vertebrates (e.g., finfish, marine mammals), while in the last few years, reports of its presence in aquatic invertebrates have been on the rise, for both freshwater and marine species. The number of cases is likely to increase as a result of increased awareness, surveillance and availability of diagnostic methods. Domestication of wild aquatic species and the intensification of modern aquaculture are also leading to an increase in the number of reported cases. Moreover, climate changes are affecting fresh and marine aquatic ecosystems. The increasing reports of mycobacteriosis in aquatic invertebrates may also be influenced by global climate warming, which could contribute to the microbes' development and survival rates, pathogen transmission and host susceptibility. Several species of the genus Mycobacterium have been diagnosed in aquatic invertebrates; a few of them are significant due to their wide host spectrum, economic impact in aquaculture, and zoonotic potential. The impact of mycobacteriosis in aquatic invertebrates is probably underestimated, and there is currently no effective treatment other than facility disinfection. In this review, we provide an overview of the diversity of mycobacterial infections reported in molluscs, crustaceans, cnidarians, echinoderms and sponges. We highlight important issues relating to its pathological manifestation, diagnosis and zoonotic considerations.

Foreign Body Granulomas

A large list of foreign substances may penetrate the skin and induce a foreign body granulomatous reaction. These particles can enter the skin by voluntary reasons or be caused by accidental inclusion of external substances secondary to cutaneous trauma. In these cases, foreign body granulomas are formed around such disparate substances as starch, cactus bristles, wood splinters, suture material, pencil lead, artificial hair, or insect mouthparts. The purpose of this article is to update dermatologists, pathologists, and other physicians on the most recent etiopathogenesis, clinical presentations, systemic associations, evaluation, and evidence-based management concerning foreign body granulomatous reactions of skin.

SEA URCHIN SPINE ARTHRITIS OF THE PROXIMAL INTERPHALANGEAL JOINT OF THE HAND: RADIOLOGICAL, INTRAOPERATIVE AND HISTOPATHOLOGICAL FINDINGS

Penetrating sea urchin spine injuries, can lead to devastating, irreversible consequences. Persistent inflammation, cutaneous granuloma, neuroma, tenosynovitis, arthritis and destructive arthritis, leading to permanent loss of function and digit amputation, can occur. We present a case of a patient who developed sea urchin spine arthritis of the proximal interphalangeal joint. Only 17 cases of sea urchin spine arthritis of the hand have been documented in the medical literature. However, in this case, the article also includes sequential radiographs, histopathological slides, and intra-operative photographs.

Sea urchin spine arthritis in the foot

We present a case of sea urchin spine arthritis (SUSA) in a 33-year-old woman who sustained penetrating trauma to the interphalangeal (IP) joint of the hallux while snorkeling in Japan. Serial radiographs and MRI were obtained over a period from 7 weeks to 10 months following injury. At 7 weeks radiographs revealed periarticular osteopenia and subtle marginal erosion, similar to the appearance of tuberculous arthritis. Over the ensuing months, radiographs and MRI documented progressive marginal and periarticular erosions with synovitis, despite preservation of cartilage space and restoration of bone mineral density. Delayed radiographs and imaging features mimic gouty arthropathy. Only the history points to the proper diagnosis, which was confirmed by histopathology, demonstrating necrobiotic granuloma with central fibrinoid necrosis following synovectomy and arthrodesis. The majority of previous case reports affected the hand, with few cases in the feet. In all, radiographic illustrations were limited and demonstrated only minimal osteolysis and periosteal reaction. No other report included MRI or serial radiographs over a long period to illustrate the natural progression of the disease.

Molecular epidemiology of mycobacteriosis in wildlife and pet animals

The ecology of mycobacteria is shifting in accordance with environmental change and new patterns of interaction between wildlife, humans, and nondomestic animals. Infection of vertebrate hosts throughout the world is greater now than ever and includes a growing prevalence in free ranging and captive wild animals. Molecular epidemiologic studies using standardized methods with high discriminatory power are useful for tracking individual cases and outbreaks, identifying reservoirs, and describing patterns of transmission and are used with increasing frequency to characterize disease wildlife. This review describes current features of mycobacteriosis in wildlife species based on traditional descriptive studies and recent molecular applications.

Detection and identification of aquatic mycobacteria in formalin-fixed, paraffin-embedded fish tissues

The isolation of mycobacteria from field samples is problematic, and isolation of the bacterium is sometimes not even attempted. The detection of mycobacteria through traditional histology using formalin-fixed, paraffin-embedded (FFPE) tissues is neither sensitive nor specific. However, detection of mycobacterial DNA from FFPE specimens, suspected of being infected with mammalian mycobacteriosis, is a routine clinical procedure. In the present study, a polymerase chain reaction (PCR)-based method was used to detect and identify mycobacteria in FFPE specimens sampled from fish suspected of being infected with fish mycobacteriosis. A total of 45 fish tissue samples, comprising of 12 tissue samples obtained from experimentally infected fish and the remainder from fish naturally infected with mycobacteria, were analysed using a PCR protocol which amplifies a fragment of the mycobacterial 65 kDa heat-shock protein (hsp65) gene. PCR-restriction enzyme analysis and/or sequencing were employed to further analyse the PCR amplicons. The PCR results were compared with those obtained by histology and culture. Mycobacterial DNA was detected in 34 of the 45 samples examined, of which 16 samples (47%) showed granulomatous reactions on histological examination. Using histology as the gold standard, no false-negative PCR results were obtained. Also, considering the presence or absence of granulomas as a diagnostic criterion, the sensitivity and specificity of PCR in 42 of the FFPE tissues were 16/16 (100%) and 8/26 (approximately 30.8%), respectively. Corresponding microbiological cultures were available for 15 cases, of which 13 were pure Mycobacterium cultures. Of these, 13 were PCR positive (100% sensitivity and 50% specificity). The PCR-based methods used here proved sensitive, specific and rapid for the detection of mycobacteria in routinely processed paraffin wax-embedded and formalin-fixed histological samples, and the results of the study suggest that this method has potential use in retrospective epidemiological studies.

Sea urchin spine arthritis of the hand

PURPOSE

Although rare, hand injury caused by puncture with the sea urchin spine can result in serious complications. To emphasize its clinical significance, this article describes a group of patients who sustained chronic granulomatous arthritis induced by puncture with sea urchin spine (designated sea urchin spine arthritis).

METHODS

Five patients who developed sea urchin spine arthritis of the hand after puncture with sea urchin spine were treated at our hospitals. All lesions involved the proximal interphalangeal (PIP) joint (4 index fingers and 1 middle finger). Patients experienced pain, swelling, and discomfort around the site of puncture immediately after the injury. These initial symptoms subsided within a few days, and secondary symptoms including fusiform swelling, limited motion, and mild pain of the PIP joint appeared from 1 to 2 months later. Laboratory tests of inflammation and blood cell counts were negative. Plain radiographs showed soft tissue swelling and osteolysis but no visible spine. Thorough synovectomy of the PIP joint was performed, and the granulation tissue around the joint was also removed.

RESULTS

No microorganism was identified from tissue culture or polymerase chain reaction in any of the 5 patients. At a mean follow-up of 21 months, 2 patients exhibited essentially normal active motion of the affected PIP joint, whereas the remaining 3 patients had diminished range of motion.

CONCLUSIONS

Diagnosis of sea urchin spine arthritis can be made by history of sea urchin spine injury, a symptom-free period before the development of synovitis, and the absence of laboratory test abnormalities. Neither antibiotics nor nonsteroidal anti-inflammatory agents are effective. Undertaken early enough, thorough synovectomy might avoid complications and obtain favorable results.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

[Mycobacterium marinum infection. Case report and review of the literature]

Atypical mycobacterial infections are increasingly important in immunosuppressed patients as well as in healthy hosts. The atypical mycobacterium that most commonly affects the skin is Mycobacterium marinum. The infection should be suspected upon the presence of ulcers, nodules or chronic plaques and a history of contact with fresh or salt water. Optimal therapy is yet to be established. We report a case of Mycobacterium marinum infection in a patient receiving immunosuppressive therapy that responded favourably to treatment with doxicycline. We review the different antibiotic regimens prescribed in the past years for the treatment of Mycobacterium marinum infection.

Distribution of mycobacteria in clinically healthy ornamental fish and their aquarium environment

Some mycobacterial species (particularly Mycobacterium marinum) found in aquarium environments may cause chronic diseases in fish and cutaneous infections in humans, the so-called 'fish tank granuloma'. The presence and distribution of mycobacterial species in clinically healthy aquarium fish and their environment has not been adequately explored. The present study analysed the occurrence of mycobacteria in a decorative aquarium (Brno, South Moravia) and in five aquaria of a professional fish breeder (Bohumin, North Moravia). After Ziehl-Neelsen staining, acid-fast rods (AFR) were observed in six (14.3%) and mycobacteria were detected by culture in 18 (42.9%) of 42 tissue samples from 19 fish. Sixty-five samples of the aqueous environment from all six aquaria were examined; AFR were found in 16 (24.6%) and mycobacteria were detected by culture in 49 (75.4%) samples. Forty-one (70.7%) of 58 selected mycobacterial isolates were identified biochemically as follows: M. fortuitum, M. flavescens, M. chelonae, M. gordonae, M. terrae, M. triviale, M. diernhoferi, M. celatum, M. kansasii and M. intracellulare. The clinically important species for humans and fish, M. marinum, was not detected. Mycobacterium kansasii was isolated from one sample of the aquarium environment from North Moravia, which is a region of the Czech Republic with endemic incidence of M. kansasii in water. The incidence of other conditionally pathogenic mycobacterial species in healthy fish and in all investigated constituents of the aquarium environment including snails and crustaceans used for fish feeding, was quite high. Accordingly, mycobacterial species from aquarium environments may serve as a possible source of infection for both aquarium fish and immunodeficient fish handlers.

Cutaneous manifestations of waterborne infections

Although waterborne pathogens are relatively uncommon causes of cutaneous infections, these agents are being recognized with increasing frequency. Humans are exposed to water through a variety of recreational and occupational activities. Poor sanitary conditions in developing nations place the human populations at constant risk. Some aquatically acquired skin infections respond well to therapy, whereas other diseases do not require a specific treatment. However, many of these infections are rare, and effective therapy has not been defined. Gram-negative bacilli constitute the largest group of aquatic pathogens that cause skin infections. Other agents include mycobacteria, fungi, viruses, and amoeba and other parasites. Toxins from aquatic animals and parasites are associated with cutaneous diseases. Because waterborne skin infections, which are caused by a wide variety of pathogens, occur infrequently, most of the literature on the topic are case reports. This paper reviews the aquatic pathogens associated with cutaneous infections in humans and the available treatments.

Atypical cutaneous mycobacteriosis diagnosed by polymerase chain reaction

Atypical mycobacteria are important human pathogens. Although they often cause systemic disease, mycobacterial infection may present solely as cutaneous lesions. It is not easy to detect nontuberculous mycobacteria by the traditional histochemical Ziehl-Neelsen stain, or by culture on specific media. Polymerase chain reaction (PCR) may be used to identify nontuberculous mycobacteria in skin lesions. We report a 40-year-old man and a 36-year-old woman, both of whom were immunocompetent and kept fish, who had skin lesions on the backs of their right hands. Ziehl-Neelsen staining and culture on Lowenstein-Jensen media were negative. Mycobacterial DNA was detected by amplification of 16S ribosomal DNA. In both cases, PCR-enzyme-linked immunosorbent assay showed a positive signal when probes for Mycobacterium (universal probe) and M. chelonae were used, and in one patient M. fortuitum was also discovered. Antibiotic therapy with clarithromycin 500 mg twice daily was begun. After 6 months of treatment, the skin lesions were cured.

Squamous cell carcinoma arising in a psoriatic nail bed: case report with discussion of diagnostic difficulties and therapeutic options

We describe a squamous cell carcinoma arising from a psoriatic nail bed. The tumour had a verrucous surface and was very well differentiated, raising the possibility of early verrucous carcinoma. Occurrence of any type of squamous carcinoma in this site and background is extremely rare. Particular diagnostic and therapeutic questions arise in this unusual setting. We discuss the aetiology and diagnostic differentiation from other nail bed squamoproliferative lesions, particularly so-called subungual keratoacanthoma. We also discuss therapeutic options, including Moh's surgery and retinoids.