Investigating hospital Mycobacterium chelonae infection using whole genome sequencing and hybrid assembly

Mycobacterium chelonae is a rapidly growing nontuberculous mycobacterium that is a common cause of nosocomial infections. Here we describe investigation of a possible nosocomial transmission of M. chelonae at the Hospital of the University of Pennsylvania (HUP). M. chelonae strains with similar high-level antibiotic resistance patterns were isolated from two patients who developed post-operative infections at HUP in 2017, suggesting a possible point source infection. The isolates, along with other clinical isolates from other patients, were sequenced using the Illumina and Oxford Nanopore technologies. The resulting short and long reads were hybrid assembled into draft genomes. The genomes were compared by quantifying single nucleotide variants in the core genome and assessed using a control dataset to quantify error rates in comparisons of identical genomes. We show that all M. chelonae isolates tested were highly dissimilar, as indicated by high pairwise SNV values, consistent with environmental acquisition and not a nosocomial point source. Our control dataset determined a threshold for evaluating identity between strains while controlling for sequencing error. Finally, antibiotic resistance genes were predicted for our isolates, and several single nucleotide variants were identified that have the potential to modulated drug resistance.

Skin and Soft Tissue Infections Caused by Mycobacterium chelonae: More Common Than Expected?

Mycobacterium chelonae is a rapidly growing non-tuberculous mycobacterium, which causes infections of the human skin and soft tissue. Despite an increasing incidence of such infections, patients are often misdiagnosed. We report here 5 patients with cutaneous and/or soft tissue infection due to M. chelonae who were diagnosed and treated at our centre. Two of the 5 patients were on immunosuppressive treatment. While clinical presentations differed in each patient, all had a long history of skin lesions. In addition to careful history-taking, tissue biopsies were obtained for mycobacterial culture and histopathological examination. Culture-directed antibiotic therapy was initiated, which resulted in a slow, but continuous, healing of the lesions. In summary, M. chelonae infections are still relatively rare, but should be considered in both immunocompromised and immunocompetent patients with prolonged skin lesions resistant to standard antibiotic treatment. For diagnosis, tissue analysis for mycobacterial culture and histopathological examination, and once diagnosed, adequate antibiotic treatment, is needed.

Description of Mycobacterium chelonae subsp. bovis subsp. nov., isolated from cattle (Bos taurus coreanae), emended description of Mycobacterium chelonae and creation of Mycobacterium chelonae subsp. chelonae subsp. nov

Three rapidly growing mycobacterial strains, QIA-37T, QIA-40 and QIA-41, were isolated from the lymph nodes of three separate Korean native cattle, Hanwoo (Bos taurus coreanae). These strains were previously shown to be phylogenetically distinct but closely related to Mycobacterium chelonae ATCC 35752T by taxonomic approaches targeting three genes (16S rRNA, hsp6 and rpoB) and were further characterized using a polyphasic approach in this study. The 16S rRNA gene sequences of all three strains showed 99.7 % sequence similarity with that of the M. chelonae type strain. A multilocus sequence typing analysis targeting 10 housekeeping genes, including hsp65 and rpoB, revealed a phylogenetic cluster of these strains with M. chelonae. DNA-DNA hybridization values of 78.2 % between QIA-37T and M. chelonae indicated that it belongs to M. chelonae but is a novel subspecies distinct from M. chelonae. Phylogenetic analysis based on whole-genome sequences revealed a 95.44±0.06 % average nucleotide identity (ANI) value with M. chelonae, slightly higher than the 95.0 % ANI criterion for determining a novel species. In addition, distinct phenotypic characteristics such as positive growth at 37 °C, at which temperature M. chelonae does not grow, further support the taxonomic status of these strains as representatives of a novel subspecies of M. chelonae. Therefore, we propose an emended description of Mycobacterium chelonae, and descriptions of M. chelonae subsp. chelonae subsp. nov. and M. chelonae subsp. bovis subsp. nov. are presented; strains ATCC 35752T(=CCUG 47445T=CIP 104535T=DSM 43804T=JCM 6388T=NCTC 946T) and QIA-37T (=KCTC 39630T=JCM 30986T) are the type strains of the two novel subspecies.

Cutaneous infections caused by rapidly growing mycobacteria: case reports and review of clinical and laboratory aspects

Skin and soft tissue infections caused by rapidly growing non-tuberculous mycobacteria (RG-NTM) have become a growing clinical concern over the past decades. These RG-NTM are ubiquitous environmental organisms and most are resistant to traditional antituberculous agents. In this report, we describe 3 cutaneous infections caused by RG-NTM, namely, Mycobacterium abscessus, M. chelonae, and M. conceptionense, and present the clinical and laboratory characteristics of these infections.

Disseminated cutaneous infection with Mycobacterium chelonae in a renal transplant recipient

Mycobacterium chelonae belongs to a rapidly growing group of nontuberculous mycobacteria (NTM). These organisms are environmental saprophytes that can cause infection in humans. Nontuberculous mycobacteria infections have been described in immunosuppressed patients (eg, in the setting of AIDS or immunotherapy following solid organ transplantation) as well as in immunocompetent patients with certain predisposing factors (eg, recent history of a traumatic wound, recent drug injections, impaired cell-mediated immunity). Due to the increasing prevalence of immune deficiency disorders as well as the rising number of cosmetic procedures performed on healthy individuals, NTM may become a frequent cause of serious morbidity, causing chronic infections of the skin, soft tissue, and lungs. We report a case of M chelonae infection in a 61-year-old woman who was receiving immunosuppressive therapy following renal transplantation 6 years prior to presentation. It is important for clinicians to consider NTM in the differential diagnosis for patients who present with chronic skin or soft tissue infections.

Mycobacterium chelonae Eye Infections Associated with Humidifier Use in an Outpatient LASIK Clinic--Ohio, 2015

Laser-assisted in situ keratomileusis (LASIK) eye surgery is increasingly common, with approximately 600,000 procedures performed each year in the United States. LASIK eye surgery is typically performed in an outpatient setting and involves the use of a machine-guided laser to reshape the lens of the eye to correct vision irregularities. Clinic A is an ambulatory surgery center that performs this procedure on 1 day each month. On February 5, 2015, the Toledo-Lucas County Health Department (TLCHD) in Ohio was notified of eye infections in two of the six patients who had undergone LASIK procedures at clinic A on January 9, 2015. The two patients experienced eye pain after the procedures and received diagnoses of infection with Mycobacterium chelonae, an environmental organism found in soil and water.

Using Syndromic Surveillance to Investigate Tattoo-Related Skin Infections in New York City

In response to two isolated cases of Mycobacterium chelonae infections in tattoo recipients where tap water was used to dilute ink, the New York City (NYC) Department of Health and Mental Hygiene conducted an investigation using Emergency Department (ED) syndromic surveillance to assess whether an outbreak was occuring. ED visits with chief complaints containing the key word "tattoo" from November 1, 2012 to March 18, 2013 were selected for study. NYC laboratories were also contacted and asked to report skin or soft tissue cultures in tattoo recipients that were positive for non-tuberculosis mycobacterial infection (NTM). Thirty-one TREDV were identified and 14 (45%) were interviewed to determine if a NTM was the cause for the visit. One ED visit met the case definition and was referred to a dermatologist. This individual was negative for NTM. No tattoo-associated NTM cases were reported by NYC laboratories. ED syndromic surveillance was utilized to investigate a non-reportable condition for which no other data source existed. The results were reassuring that an outbreak of NTM in tattoo recipients was not occurring. In response to concerns about potential NTM infections, the department sent a letter to all licensed tattoo artists advising them not to dilute tattoo ink with tap water.

Fatal Disseminated Mycobacterium chelonae Infection in an Immunocompromised Host--A Unique Presentation

Disseminated disease due to rapidly growing non tuberculous mycobacteria especially in the immunocompromised host is being increasingly reported. The usual manifestations of disease being skin and soft tissue infection, post operative wound infection and pulmonary disease. We present a case of a disseminated infection due to Mycobacterium chelonae with features of chronic meningitis and knee joint arthritis in a patient with systemic lupus erythematosus on systemic steroids and mycophenolate. M chelonae was isolated from both synovial and cerebrospinal fluid and anti microbial therapy was initiated as per sensitivity results. However the patient's clinical condition continued to worsen and she succumbed to her illness.

Mycobacterium chelonae infection presenting as recurrent cutaneous and subcutaneous nodules--a presentation previously diagnosed as Weber Christian disease

Although the dermatologic community rarely uses "Weber-Christian Disease" as a diagnosis, it still appears in the internal medicine literature. Herein we present a patient with recurrent cutaneous and subcutaneous nodules who was initially treated with aggressive immunosupression for a presumptive diagnosis of Weber-Christian Disease. After more than a decade the patient was diagnosed with cutaneous Mycobacterium chelonea. This case is an excellent example of the difficulty in diagnosing mycobacterial infections and underscores the importance of having a high suspicion for infectious etiologies for unresponsive cutaneous eruptions in patients on immunosuppressive medications.

Novel species including Mycobacterium fukienense sp. is found from tuberculosis patients in Fujian Province, China, using phylogenetic analysis of Mycobacterium chelonae/abscessus complex

OBJECTIVE

To identify the novel species 'Mycobacterium fukienense' sp. nov of Mycobacterium chelonae/abscessus complex from tuberculosis patients in Fujian Province, China.

METHODS

Five of 27 clinical Mycobacterium isolates (Cls) were previously identified as M. chelonae/abscessus complex by sequencing the hsp65, rpoB, 16S-23S rRNA internal transcribed spacer region (its), recA and sodA house-keeping genes commonly used to describe the molecular characteristics of Mycobacterium. Clinical Mycobacterium isolates were classified according to the gene sequence using a clustering analysis program. Sequence similarity within clusters and diversity between clusters were analyzed.

RESULTS

The 5 isolates were identified with distinct sequences exhibiting 99.8% homology in the hsp65 gene. However, a complete lack of homology was observed among the sequences of the rpoB, 16S-23S rRNA internal transcribed spacer region (its), sodA, and recA genes as compared with the M. abscessus. Furthermore, no match for rpoB, sodA, and recA genes was identified among the published sequences.

CONCLUSION

The novel species, Mycobacterium fukienense, is identified from tuberculosis patients in Fujian Province, China, which does not belong to any existing subspecies of M. chelonea/abscessus complex.

[Drug sensitivity analysis of Mycobacterium chelonae and Mycobacterium abscessus and evaluation of Etest for susceptibility testing]

OBJECTIVE

To study the drug resistance profile of Mycobacterium(M.) chelonae and M.abscessus and to evaluate the clinical application of Etest(epsilometer test) for susceptibility testing.

METHODS

Twenty clinical isolates of M.abscessus and 16 clinical isolates of M.chelonae from clinical specimens were collected.Strain identification was carried out by GenoType Mycobacterium CM assay(Hain Lifescience, Germany). The accuracy was evaluated by comparing Etest results to those obtained by broth microdilution. Thirty-six isolates were tested against amikacin, cefoxitin, ciprofloxacin, clarithromycin, doxycycline, imipenem, linezolid, sulfamethoxazole and tobramycin. The agreement among MICs and interpretive category was evaluated. Chi-squared test was used to compare observed frequency of each of the 2 examples.

RESULTS

All of the isolates(36/36) were sensitive to amikacin and cefoxitin, and only 1 isolate(1/36) was resistant to clarithromycin, but more isolates(29/36) were resistant to ciprofloxacin, doxycycline, imipenem and sulfamethoxazole.For M.chelonae, only 2/16 were resistant to linezolid, and 7/16 resistant to tobramycin.For M.abscessus, more than 12/20 were resistant to linezolid and 16/20 resistant to tobramycin. The agreement between broth microdilution MICs and Etest MICs for 9 drugs was 149/324.With amikacin, clarithromycin, doxycycline and imipenem, the agreement for interpretive category was excellent(35/36), followed by sulfamethoxazole(34/36), which corresponded to rarely very major error of 2/36.With ciprofloxacin and tobramycin, agreement for interpretive category was 31/36 and 26/36.With cefoxitin and linezolid, the agreement of Etest MICs was the lowest(14/36), resulting in the resistant category.

CONCLUSIONS

Isolates of M.chelonae and M.abscessus exhibit far more susceptibility to amikacin, cefoxitin and clarithromycin than any other antimicrobial agents.Linezolid and tobramycin showed sensitivity to some isolates of M.chelonae.It is suitable for the Etest method as a simple reliable method for the drug susceptibility of amikacin, ciprofloxacin, clarithromycin, doxycycline, imipenem, and tobramycin except to cefoxitin and linezolid. The Etest method of determining sulfamethoxazole susceptibility should be careful.

Mycobacterium chelonae facial infections following injection of dermal filler

A cluster of 3 facial Mycobacterium chelonae infections occurred after cosmetic dermal filler injections at a plastic surgery clinic. Pulsed-field gel electrophoresis showed that M chelonae isolated from the clinic tap water were identical to the patient wound isolates. Review of injection procedures identified application of nonsterile ice to the skin prior to injection as a possible source of M chelonae. Surveys of regional laboratories and a national plastic surgery listserv identified no other cases related to the injection of this brand of dermal filler. This is the first report of cutaneous M chelonae infections following the injection of dermal fillers. It adds to a growing body of literature on postinjection M chelonae infections and reinforces the importance of optimal skin disinfection steps prior to percutaneous procedures.

LEVEL OF EVIDENCE

5.

[Atypical mycobacterial infection after kidney transplant: two clinical cases]

Infections are an important cause of morbidity and mortality during kidney transplant. In areas where tuberculosis is not endemic, Mycobacteria other than tuberculosis (MOOT), also known as 'atypical' Mycobacteria, are more frequently involved in mycobacterial infections than M. tuberculosis. The incidence of MOOT infection in renal transplant recipients ranges from 0.16 to 0.38 percent. This low rate of reported incidence is, however, often due to delay in diagnosis and lack of therapeutic protocols. Further difficulty is caused by the interaction of antimycobacterial drugs with the post-transplant immunosuppressive regimen, necessitating close monitoring of plasma concentrations and careful dose modification. We present two cases of Mycobacterium Chelonae infection in kidney transplant recipients which differ in both clinical presentation and pharmacological approach.

Outbreak of Mycobacterium chelonae infection associated with tattoo ink

BACKGROUND

In January 2012, on the basis of an initial report from a dermatologist, we began to investigate an outbreak of tattoo-associated Mycobacterium chelonae skin and soft-tissue infections in Rochester, New York. The main goals were to identify the extent, cause, and form of transmission of the outbreak and to prevent further cases of infection.

METHODS

We analyzed data from structured interviews with the patients, histopathological testing of skin-biopsy specimens, acid-fast bacilli smears, and microbial cultures and antimicrobial susceptibility testing. We also performed DNA sequencing, pulsed-field gel electrophoresis (PFGE), cultures of the ink and ingredients used in the preparation and packaging of the ink, assessment of source water and faucets at tattoo parlors, and investigation of the ink manufacturer.

RESULTS

Between October and December 2011, a persistent, raised, erythematous rash in the tattoo area developed in 19 persons (13 men and 6 women) within 3 weeks after they received a tattoo from a single artist who used premixed gray ink; the highest occurrence of tattooing and rash onset was in November (accounting for 15 and 12 patients, respectively). The average age of the patients was 35 years (range, 18 to 48). Skin-biopsy specimens, obtained from 17 patients, showed abnormalities in all 17, with M. chelonae isolated from 14 and confirmed by means of DNA sequencing. PFGE analysis showed indistinguishable patterns in 11 clinical isolates and one of three unopened bottles of premixed ink. Eighteen of the 19 patients were treated with appropriate antibiotics, and their condition improved.

CONCLUSIONS

The premixed ink was the common source of infection in this outbreak. These findings led to a recall by the manufacturer.

Centers for Disease Control and Prevention (CDC). Tattoo-associated nontuberculous mycobacterial skin infections--multiple states, 2011-2012

Permanent tattoos have become increasingly common, with 21% of adults in the United States reporting having at least one tattoo. On rare occasions, outbreaks of nontuberculous mycobacterial (NTM) skin infections have been reported after tattooing. In January 2012, public health officials in New York received reports of Mycobacterium chelonae skin infections in 14 New York residents who received tattoos during September-December 2011. All infections were associated with use of the same nationally distributed, prediluted gray ink manufactured by company A. CDC disseminated an Epi-X public health alert to identify additional tattoo-associated NTM skin infections; previously identified cases were reported from three states (Washington, Iowa, and Colorado). Public health investigations by CDC, state and local health departments, and the Food and Drug Administration (FDA) found NTM contamination in tattoo inks used in two of five identified clusters. All infected persons were exposed to one of four different brands of ink. NTM contamination of inks can occur during the manufacturing process as a result of using contaminated ingredients or poor manufacturing practices, or when inks are diluted with nonsterile water by tattoo artists. No specific FDA regulatory requirement explicitly provides that tattoo inks must be sterile. However, CDC recommends that ink manufacturers ensure ink is sterile and that tattoo artists avoid contamination of ink through dilution with nonsterile water. Consumers also should be aware of the health risks associated with getting an intradermal tattoo.

Breast infections with atypical mycobacteria following reduction mammaplasty

Reduction mammaplasty is one of the most common plastic surgery procedures performed in the US, with the goal of correcting symptomatic macromastia. More than 70,000 cases were performed in 2009, with few complications and low infection rates. The authors present two cases of breast infections with Mycobacterium fortuitum and one with Mycobacterium chelonei following bilateral reduction mammaplasty. Infection with these organisms is exceptionally rare following breast surgery in the absence of a prosthetic implant. All of the patients had a delayed presentation following complete wound healing and were refractory to first-line antibiotic therapy. All three required long-term antibiotics in consultation with an infectious disease specialist. The patients all required surgical drainage, and two patients also required formal operative debridement. All three patients eventually went on to complete wound healing.

Mycobacterium chelonae complex bacteremia from a post-renal transplant patient: case report and literature review

In this report we present a case of a young lady with abdominal abscesses and septicemia caused by Mycobacterium chelonae complex. Identification of the organism and initiation of the appropriate antimicrobial therapy was delayed, resulting in significant morbidity and multiple hospital admissions. Gram staining of these organisms from blood culture can be easily overlooked or confused with either debris or diptheroids. We concluded that detection of Gram-positive rod colonies should prompt an acid-fast stain to distinguish diphtheroids from rapidly growing mycobacteria in immunosuppressed patients.

A case of infected scleral buckle with Mycobacterium chelonae associated with chronic intraocular inflammation

PURPOSE

To describe a unique case of chronic intraocular inflammation secondary to scleral buckle infection with Mycobacterium chelonae that was successfully treated with buckle explantation.

METHODS

Case report.

RESULTS

A 59-year-old male with a history of retinal detachment repair at the age of 41 presented with chronic, recurrent intraocular inflammation responsive to topical corticosteroids. Conjunctival erosion with exposure of the scleral buckle occurred five months after initial presentation. The scleral buckle was removed and cultured. After three weeks of postoperative topical tobramycin and dexamethasone treatment, the patient has remained symptom-free without medications. The explanted material grew acid-fast bacilli later identified as M. chelonae.

CONCLUSIONS

This case describes a new finding of chronic intraocular inflammation associated with a scleral buckle infected with M. chelonae and the successful resolution of extraocular infection and intraocular inflammation after buckle removal.

Visual Recovery FollowingMycobacterium chelonaeEndophthalmitis

Following uncomplicated cataract surgery, a patient receiving etanercept for psoriatic arthritis developed Mycobacterium chelonae endophthalmitis. Vitrectomy, capsulectomy, and intraocular lens removal was followed by intravitreal amikacin, topical gatifloxacin, intravenous imipenem, and oral clarithromycin for six months. The patient achieved a final corrected visual acuity of 20/20. Etanercept has been implicated in the development of numerous, severe granulomatous infections, though not previously with M. chelonae. This represents the first reported case of visual recovery following M. chelonae endophthalmitis.

Distribution and genetic characterization of Mycobacterium chelonae in laboratory zebrafish Danio rerio

During routine screening of zebrafish at a research facility, histological changes consistent with mycobacteriosis were observed, prompting an investigation to determine the background prevalence and distribution of Mycobacterium species throughout the facility. Infection status was evaluated in 240 zebrafish representing 9 genetic lines, using histology, culture and PCR. Environmental sources were also tested for the presence of mycobacteria. Prevalence in zebrafish by culture and PCR was 10% (24/240), 21 of which were TU line fish. All isolates from fish were identified as M. chelonae by hsp65 DNA sequencing; subsequent DNA fingerprinting delineated 3 strains, designated H1E1 (1/24), H1E2 (22/24), and H1E3 (1/24). From external sources, tank or tubing surface biofilms were positive by culture (13/32) with multiple species and strains isolated including M. neoaurum, M. phocaicum, and identical strains of M. chelonae that were found in zebrafish: H1E1 (2/13) and H1E2 (8/13). Comparing diagnostic methods, acid-fast stained histological sections showed substantial agreement with plate culture and PCR for detection of mycobacteria in fish. Observation of granulomas in hematoxylin and eosin-stained sections was a less reliable predictor of mycobacteriosis, as uninfected females with egg-associated inflammation and hyperplasia were misdiagnosed. These data revealed background levels of mycobacteriosis in a healthy and well-managed facility. Infected populations were removed, although the apparent ability for M. chelonae to remain viable in environmental reservoirs may make it difficult to eradicate completely. This highlights the importance of an animal-health monitoring program and good husbandry practices to prevent disease in zebrafish research laboratories.

Predominance of Mycobacterium fortuitum-chelonae complex in Ghatampur field area, endemic for leprosy

Non-tuberculous mycobacteria (NTM) are commonly found in the environment. As exposure to environmental mycobacteria has been reported to immunomodulatory in this study, the presence of environmental mycobacteria was investigated in soil, drinking water and drainage sample in Ghatampur, India, which is known for high endemicity for leprosy. Soil, drinking water from the hand pumps/wells and also drainage water collected in pools was collected in clean containers and cultured for environmental mycobacteria. Samples were processed according to the protocol established earlier. 69 soil, 62 drinking water and 31 drainage water samples were analysed from soil and water collected from 48 villages of this field area. After decontamination, cultures were set upon Lowenstein Jensen (LJ) medium. Mycobacteria were identified using biochemical tests and molecular techniques such as PCR-RFLP targeting hsp65 kD and rpoB region as well as 16S ribosomal sequencing in case of isolates showing variable biochemical features. NTM (non-tubercular mycobacteria) were isolated from 47.82% of soil samples, 20.69% of drinking water samples and 19.35% of the drainage water samples, overall mycobacteria could be isolated 52/162 of samples (32.09%). Among these mycobacteria, M. fortuitum-chelonae complex was predominant in this area; other species isolated were M. phlei, M. vaccae, M. terrae and M. flavescens. Relevance of exposure to these mycobacteria on endemicity needs to be studied by immunological and epidemiological parameters.

Postoperative infection of laparoscopic surgery wound due to Mycobacterium chelonae

We report a case of postoperative wound infection due to Mycobacterium chelonae. A 35-year-old woman presented with multiple erythematous nodules, plaques and discharging sinuses over the abdomen, 45 days after she had undergone laparoscopic ovarian cystectomy. The seropurulent discharge from the wound showed acid-fast bacilli on Ziehl- Neelsen stain and culture yielded Mycobacterium chelonae. The patient responded to clarithromycin and doxycycline. The source of infection was probably contaminated water or disinfectant solution used for sterilization of laparoscopic instruments.

Nontuberculous mycobacterial peritonitis in peritoneal dialysis patients

While nontuberculous mycobacterial peritonitis is uncommon among peritoneal dialysis (PD) patients, these infections have serious consequences. They present a significant diagnostic and therapeutic challenge for clinicians. Diagnosis can be delayed due to the slow growth rate of some mycobacterial species. These organisms can also be overlooked when adequate culture media are not used in the microbiological evaluation process. The choice of antimicrobial therapy depends upon isolation and speciation of the infecting Mycobacterium species, and prompt catheter removal is essential. Because serious intra-abdominal complications may follow infection, identifying patient risk factors for nontuberculous mycobacterial peritonitis and initiating prompt diagnosis and treatment are essential. We report three cases of peritonitis associated with Mycobacterium chelonae and Mycobacterium gordonae, each with a unique presentation, and discuss the appropriate diagnosis and treatment strategies for the management of PD-associated mycobacterial infections.

Association of mycobacteria with Eales' disease

BACKGROUND & OBJECTIVES

Eales' disease is an idiopathic disease resulting in retinal neovascularization, recurrent haemorrhages, with or without retinal detachment predominantly affecting healthy young males (97.6%) in the Indian subcontinent. Inspite of several studies, the aetiology of Eales' disease is not clear. The isolation of Mycobacterium fortuitum from the aqueous humour of a patient with classical Eales' disease, led us to hypothesize that rapid growing nontuberculous mycobacteria (RGNTM), particularly M. fortuitum and M. chelonae could be associated with Eales' disease. We therefore undertook this study to detect DNA of these RGNTM and also of M. tuberculosis in vitreous fluids (VFs) from patients with Eales' disease and non-Eales' disease.

METHODS

We developed and optimized seminested polymerase chain reactions (SnPCRs) to detect DNAs of M. fortuitum and M. chelonae on archival ERMs (33) and VFs (19) of Eales' and control patients along with conventional mycobacteriological investigations.

RESULTS

In the retrospective study, 70 per cent ERM samples were positive for one or more Mycobacterium spp. tested by snPCR. M. fortuitum and M. chelonae were isolated from two VFs, which were also positive by sn PCR in the prospective study. Statistical evaluation of the results of both retrospective and prospective investigations showed a statistically significant association of Mycobacterium spp. with Eales' disease.

INTERPRETATION & CONCLUSION

The results of the present study suggested the involvement of Mycobacterium spp. in the aetiopathogenesis of Eales' disease. Further studies on a larger sample will be required to confirm these findings.

Atypical mycobacteria keratitis after laser in situ keratomileusis unresponsive to fourth-generation fluoroquinolone therapy

We report a case of post-laser in situ keratomileusis atypical mycobacteria infection unresponsive and resistant to fourth-generation fluoroquinolones, which highlights the importance of a high level of suspicion and the need for multidrug therapy for effective eradication.

Infections with atypical mycobacteria in renal transplant recipients

Infections due to atypical mycobacteria are infrequent in renal transplant recipients but they cause serious morbidity. These pathogens are common in patients with acquired immune deficiency syndrome (AIDS). We report four proven cases of infections caused with atypical mycobacteriae from 1997 to 2003, by different organisms namely, M. chelonei, M.fortuitum, M. abcessus and M. terrae in renal transplant recipients. Infection with M. terrae documented here is the first occurrence in a renal transplant patient. Histopathological examination of aspirates or biopsy specimens from involved areas and staining and culture for mycobacteriae are essential for diagnosis. Treatment involves antimycobacterial therapy, reduction in immunosuppression and surgery, if indicated. Atypical mycobacterial infections, though currently uncommon, are significant and could prove to be an emerging pathogen in renal transplant recipients in the context of the AIDS epidemic in India.

Skin and joint infection by Mycobacterium chelonae: Rescue treatment with interferon gamma

INTRODUCTION

Atypical mycobacteria are environmental organisms that cause opportunistic infections in humans.

CASE REPORT

A 50-year-old electronics engineer sought advice about starting TNFalpha antagonist therapy for ankylosing spondylitis. Disease duration was 23 years and current treatment was methylprednisolone 4 mg/d. Atypical skin lesions and knee arthritis were noted. Fluid aspirated from the knee showed inflammatory properties and a few acid-fast bacteria, which a line probe assay identified as Mycobacterium chelonae. The same organism was found in a skin biopsy from a thigh lesion. Antimicrobial treatment was started immediately. Inadequate results 6 months later prompted synovectomy of the knee followed by interferon gamma, 50 microg/m(2) body surface area subcutaneously 3 times a week. After 16 months, there were no new skin or joint lesions, and the antimicrobials and interferon gamma were therefore discontinued.

CONCLUSION

This highly unusual case suggests that interferon gamma may be effective in patients with M. chelonae infection that fails to respond adequately to antimicrobials.

A cluster of rapidly growing mycobacterial peritoneal dialysis catheter exit-site infections

In this case series, a cluster of 5 consecutive peritoneal dialysis patients with atypical mycobacterial exit-site infections in a single center within 20 months are described. Clinical features, treatment, and outcomes are discussed. Most patients had been treated with prolonged systemic antibiotic therapy for recurrent bacterial exit-site infections in the preceding months, and all had used topical gentamicin ointment for exit-site infection treatment or prophylaxis. It is postulated that this might have predisposed them to atypical mycobacterial exit-site infection as a result of selection pressure on uncommon organisms.

Nontuberculous mycobacteria infection after mesotherapy: Preliminary report of 15 cases

BACKGROUND

Mesotherapy is an increasingly used technique which is currently causing several mycobacterial infections owing to contaminated substances being injected, and also to poor aseptic measures being held by nonprofessional practitioners.

PATIENTS AND METHODS

We collected 15 cases of nontuberculous mycobacteria (NTM) infection after mesotherapy in a 6-month period.

RESULTS

All patients were female with ages ranging from 19 to 52 years; the main substances injected were procaine and lecithin, and the time between mesotherapy and the appearance of the lesions varied between 1 and 12 weeks. Clinical lesions were mostly nodules and abscesses, which were localized in the abdomen and buttocks in the majority of cases. The main patient complaint was local pain but some presented with systemic symptoms such as fever and malaise. Biopsies reported granulomatous chronic inflammation in the majority of cases. Skin cultures were positive for NTM and Mycobacterium chelonae.

DISCUSSION AND CONCLUSIONS

Mesotherapy not performed with quality controlled substances can be a predisposing factor for NTM infection.