|Year : 1997 | Volume
| Issue : 6 | Page : 376-378
Mycobacterium Fortuitum in Cutaneous Infections
BM Hemashettar, AM Pandit, B Siddaramappa, Manjun
B M Hemashettar
Source of Support: None, Conflict of Interest: None
Three cases of culture proven primary cutaneous infections caused by Mycobacterium fortuitum, a rapidly growing non tuberculous mycobacterium, are reported. The first case was treated with ciprofloxacin and the other two, with trimethoprim / sulphamethoxazole with an excellent outcome.
Keywords: Mycobacterium, Skin infection
|How to cite this article:|
Hemashettar B M, Pandit A M, Siddaramappa B, Manjun. Mycobacterium Fortuitum in Cutaneous Infections. Indian J Dermatol Venereol Leprol 1997;63:376-8
|How to cite this URL:|
Hemashettar B M, Pandit A M, Siddaramappa B, Manjun. Mycobacterium Fortuitum in Cutaneous Infections. Indian J Dermatol Venereol Leprol [serial online] 1997 [cited 2019 Jul 15];63:376-8. Available from: http://www.ijdvl.com/text.asp?1997/63/6/376/4623
Rapidly growing mycobacteria are uncommon human pathogens. Two members of this group, Mycobacterium fortuitum and M chelonae have been identified as opportunistic pathogens.
M. fortuitum is ubiquitously distributed in nature. They have been recovered from soil, dust, water, milk and even from saliva of healthy human beings. Till recently, the organism was considered to be a harmless saprophyte. Lately, there have been several reports wherein it has been incriminated in a variety of human infections.  Most investigators agree that these organisms are of relatively low virulence and infections are generally associated with decreased host resistance or a heavy inoculum. 
In the present communication, we are reporting three cases of culture proven primary cutaneous infections caused by this non tuberculous mycobacterium.
| Case Reports|| |
Case 1 A previously healthy, 37-year-old army man presented with multiple nodules on the anterior abdominal wall since one month. The first of the lesions appeared as a small nodule, gradually increased in size that led to suppuration and discharge of pus. Later on, other lesions developed. The patient gave history of trauma to the abdominal wall several months ago.
Examination of anterior abdominal wall showed three oval nodular lesions each measuring 2-21/2X 2-3 cms. They were non tender firm to cystic on palpation. Two more lesions which were not visible externally, could be felt on palpation.
Routine haematology, urinalysis and biochemical tests were within normal limits. HIV 1 and 2 and blood VDRL tests were non reactive.
Pus aspirated with aseptic precautions from the lesions, was inoculated on chocolate as well as on Macconkey agars and incubated at 37°c. Gram stained smear showed plenty of pus cells but no organisms. After 5 days of incubation, a number of small creamy white colonies appeared on chocolate agar and lactose fermenting colonies on Macconkey agar. The isolate was identified as M.fortuitum complex by standard techniques (R). After isolation of this unexpected pathogen, the pus smear was stained by ZiehlNeelsen method and it showed acid fast bacilli. Based on sensitivity tests, the patient was advised tab. ciprofloxacin 500mg bid for 6 weeks. The recovery was complete and uneventful.
Case 2 A 35-year-old woman was referred for a microbiological work-up with a clinical diagnosis of sporotrichosis / atypical mycobacterial infection. The patient had 3 nodular lesions arranged in a linear fashion on the extensor aspect of the right forearm since about 1 month. No other information in the history, general examination or routine investigations were contributory to the present illness. Pus from the lesions showed acid fast organisms and culture yielded M.foruitum complex. A course of trimethoprim / sulfamethoxazole was instituted for a period of 6 weeks. There was significant improvement when the patient was discharged.
Case 3 A 15-year-old girl presented with complaints of nodular lesions over the dorsum of the hand and the middle finger since 2 months. There were no constitutional symptoms. General physical examination, routine haematology, clinical chemistry and serological tests were within normal limits. Aspirated contents of the nodules showed acid fast organisms, and the Mfortuitum complex was isolated in pure culture. The patient was treated with trimethoprim / sulfamethoxazole for a period of 6 weeks. The patient responded well to treatment.
| Discussion|| |
Cutaneous lesions caused by Mfortuitum may occur in three clinical settings; a) post surgical, most commonly reported in sternotomy wounds, b) as a manifestation of disseminated disease, usually occurring in immunocompromised host with signs and symptoms of a systemic infection, and c) primary cutaneous infections (non surgical). The last type usually occurs as a localized infection in an otherwise healthy individual, with a history of trauma 1-2 months before developing symptoms at the involved site. When dissemination occurs, usually the primary source is unknown. Morphologically, the patients may present with abscesses, ulcers, draining sinus tracts, cellulitis or tender erythematous nodules. Occasionally the lesions may be multiple and tend to be distributed along the course of the afferent lymphatics, simulating the lesions of sporotrichosis, often referred to as 'sporotrichoid mycobacteriosis.  All the three cases presented here could be included in this category.
Rapid growing mycobacteria as a group are resistant to conventional antimycobacterial agents used to treat tuberculosis but are susceptible to several other antibiotics. However, species vary in their susceptibility to different antibiotics. Hence proper identification and speciation of the isolates are important for selection of appropriate antibiotics. The presence of tetracycline resistance genetic determinants in members of the group clearly precludes the use of tetracyclines.  However, they are susceptible to amikacin, ciprofloxacin, sulfonamides, cefoxitin, imipenem, clarithromycin and azithromycin.  In addition to the antibiotics, drainage and debridement of the lesions is advocated.
Unlike infections of the lung, wherein disease caused by acid fast organisms is frequently considered, cutaneous and soft tissue lesions are seldom considered as being caused primarily by acid fast organisms. Hence a delay in diagnosis is the rule rather than an exception. A high index of suspicion and diligent search for acid fast organism in all purulent samples wherein gram stainable organism in all purulent samples wherein gram stainable organisms are not demonstrated and inclusion of appropriate media with sufficiently long incubation period are likely to prove beneficial.
| Acknowledgement|| |
We thank Dr. V.L. Jahagirdar, Professor of Microbiology, Dr. V.M. Medical College, Sholapur and the Directors of Tuberculosis Research Centre, Madras as well as National Tuberculosis Institute, Bangalore for confirming the identity and sensitivity of the isolates.
| References|| |
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