An outbreak of post-surgical wound infections due to Mycobacterium abscessus

The Many Hosts of Mycobacteria 8 (MHM8): A conference report

Mycobacteria are important causes of disease in human and animal hosts. Diseases caused by mycobacteria include leprosy, tuberculosis (TB), nontuberculous mycobacteria (NTM) infections and Buruli Ulcer. To better understand and treat mycobacterial disease, clinicians, veterinarians and scientists use a range of discipline-specific approaches to conduct basic and applied research, including conducting epidemiological surveys, patient studies, wildlife sampling, animal models, genetic studies and computational simulations. To foster the exchange of knowledge and collaboration across disciplines, the Many Hosts of Mycobacteria (MHM) conference series brings together clinical, veterinary and basic scientists who are dedicated to advancing mycobacterial disease research. Started in 2007, the MHM series recently held its 8th conference at the Albert Einstein College of Medicine (Bronx, NY). Here, we review the diseases discussed at MHM8 and summarize the presentations on research advances in leprosy, NTM and Buruli Ulcer, human and animal TB, mycobacterial disease comorbidities, mycobacterial genetics and 'omics, and animal models. A mouse models workshop, which was held immediately after MHM8, is also summarized. In addition to being a resource for those who were unable to attend MHM8, we anticipate this review will provide a benchmark to gauge the progress of future research concerning mycobacteria and their many hosts.

Mycobacterium abscessus subsp. abscessus empyema complicated with subcutaneous abscess

There have been no case reports of thoracic subcutaneous abscess after surgery for Mycobacterium abscessus complex associated empyema. We herein report a case of Mycobacterium abscessus subsp. abscessus (M. abscessus subsp. abscessus) induced subcutaneous abscesses following surgical treatment for concurrent M. abscessus subsp. abscessus -associated empyema and pneumothorax. A 75-year-old woman had M. abscessus subsp. abscessus -associated empyema and pneumothorax. She underwent surgical treatment of decortication and fistulectomy and suffered from M. abscessus subsp. abscessus -associated subcutaneous abscesses after thoracentesis/drainage. A multidisciplinary approach combined with surgical care, thermal therapy, and multidrug chemotherapy contributed to a successful result. An early multidisciplinary approach is believed to be important in cases of M. abscessus subsp. abscessus -associated empyema and subcutaneous abscess.

Medical Tourism and Postoperative Infections: A Systematic Literature Review of Causative Organisms and Empiric Treatment

BACKGROUND

Medical tourism has become increasingly globalized as individuals travel abroad to receive medical care. Cosmetic patients in particular are more likely to seek surgery abroad to defray costs. Unfortunately, not all procedures performed abroad adhere to strict hygienic regulations, and bacterial flora vary. As a result, it is not uncommon for consumers to return home with difficult-to-treat postoperative infections.

METHODS

A systematic literature review of PubMed, Ovid, Web of Science, and Cumulative Index to Nursing and Allied Health Literature databases was performed to assess the microbiology patterns and medical management of patients with postoperative infections after undergoing elective surgery abroad.

RESULTS

Forty-two cases of postoperative infections were reported among patients who underwent elective surgery abroad. Most cases were reported from the Dominican Republic, and the most common elective procedures were abdominoplasty, mastopexy, and liposuction. Rapidly growing mycobacteria such as Mycobacterium abscessus, Mycobacterium fortuitum, and Mycobacterium chelonae were among the most common causes of postoperative infection, with M. abscessus involving 74 percent of cases. Most cases were treated with surgical débridement and a combination of antibiotics. Clarithromycin, amikacin, and moxifloxacin were the most common drugs used for long-term treatment.

CONCLUSIONS

When encountering a patient with a history of medical tourism and treatment-refractory infection, rapidly growing mycobacteria must be considered. To increase the likelihood of yielding a diagnostic organism, multiple acid-fast bacilli cultures from fluid and débridement content should be performed. There has been reported success in treating rapidly growing mycobacterial infections with a combination of antibiotics including clarithromycin, amikacin, and moxifloxacin.

Preventing Postoperative Atypical Mycobacterial Infection

PURPOSE

To report a recent outbreak of atypical mycobacterial infection following upper eyelid surgery and the results of a prevention protocol that was successfully instituted to dramatically reduce the infection rate.

METHODS

This is a multicenter retrospective nonrandomized comparative interventional case series. A chart review of 7 patients who developed atypical mycobacterium infection after undergoing blepharoplasty was conducted. Preventative intervention included exchanging ice compresses for reusable gel packs and substituting tap water with bottled or distilled water for facial cleaning during postoperative care. The main outcome measure was disease incidence.

RESULTS

Of the 368 patients who underwent upper eyelid blepharoplasty and/or blepharoptosis repair from December 2014 to May 2015, 7 people developed cutaneous atypical mycobacterium infection with an incidence of 1.9%. Eighty-six percent of patients received clarithromycin as part of their treatment with average treatment length of 2.8 months. Debridement was performed in 71% of the patients. Biopsy was performed in all patients, and all had histopathology showing granulomatous inflammation. A prevention protocol was developed to reduce potential inoculation in the immediate postoperative period, which successfully reduced the infection rate from 1.9% to 0.06% (p = 0.019).

CONCLUSIONS

Atypical mycobacterium infection, although rare, should be considered as a possible diagnosis in a blepharoplasty patient with delayed development of nodular lesions. Long-term clarithromycin therapy and debridement have shown good outcomes for these patients; however, the best treatment for any infection is prevention. This study provides the first evidence based approach within the ophthalmic literature for reducing the mycobacterium infection rate in blepharoplasty patients.

Mycobacterium abscessus Infections in Children: A Review of Current Literature

There is limited literature on Mycobacterium abscessus infections in children and limited data about its diagnosis and management. The incidence of infections due to M abscessus appears to be increasing in certain populations and can be a significant cause of morbidity and mortality.Management of these infections is challenging and relies on combination antimicrobial therapy and debridement of diseased tissue, depending on the site and extent of disease. Treatment regimens often are difficult to tolerate, and the antimicrobials used can cause significant adverse effects, particularly given the long duration of therapy needed.This review summarizes the literature and includes information from our own institution's experience on pediatric M abscessus infections including the epidemiology, transmission, clinical manifestations, and the management of these infections. Adult data have been used where there are limited pediatric data. Further studies regarding epidemiology and risk factors, clinical presentation, optimal treatment, and outcomes in children are necessary.

Two-Phase Hospital-Associated Outbreak of Mycobacterium abscessus: Investigation and Mitigation

Background

Nontuberculous mycobacteria (NTM) commonly colonize municipal water supplies and cause healthcare-associated outbreaks. We investigated a biphasic outbreak of Mycobacterium abscessus at a tertiary care hospital.

Methods

Case patients had recent hospital exposure and laboratory-confirmed colonization or infection with M. abscessus from January 2013 through December 2015. We conducted a multidisciplinary epidemiologic, field, and laboratory investigation.

Results

The incidence rate of M. abscessus increased from 0.7 cases per 10000 patient-days during the baseline period (January 2013-July 2013) to 3.0 cases per 10000 patient-days during phase 1 of the outbreak (August 2013-May 2014) (incidence rate ratio, 4.6 [95% confidence interval, 2.3-8.8]; P < .001). Thirty-six of 71 (51%) phase 1 cases were lung transplant patients with positive respiratory cultures. We eliminated tap water exposure to the aerodigestive tract among high-risk patients, and the incidence rate decreased to baseline. Twelve of 24 (50%) phase 2 (December 2014-June 2015) cases occurred in cardiac surgery patients with invasive infections. Phase 2 resolved after we implemented an intensified disinfection protocol and used sterile water for heater-cooler units of cardiopulmonary bypass machines. Molecular fingerprinting of clinical isolates identified 2 clonal strains of M. abscessus; 1 clone was isolated from water sources at a new hospital addition. We made several water engineering interventions to improve water flow and increase disinfectant levels.

Conclusions

We investigated and mitigated a 2-phase clonal outbreak of M. abscessus linked to hospital tap water. Healthcare facilities with endemic NTM should consider similar tap water avoidance and engineering strategies to decrease risk of NTM infection.

Outbreak of Rapidly Growing Nontuberculous Mycobacteria Among Patients Undergoing Cosmetic Surgery in the Dominican Republic

Rapidly growing nontuberculous mycobacteria (RG-NTM), which can contaminate inadequately sterilized medical instruments, have been known to cause serious postsurgical skin and soft tissue infections that often are characterized by a prolonged incubation period and a disfiguring clinical course. Historically, these infections have been associated with surgical procedures performed outside the United States. The Centers for Disease Control and Prevention recently reported an outbreak of RG-NTM infections among women who underwent cosmetic surgery in the Dominican Republic. Because of the large Dominican American community in upper Manhattan, we have recently observed a number of these cases at NewYork-Presbyterian Hospital/Columbia University Medical Center. We highlight the case of a 55-year-old woman who developed a postsurgical RG-NTM infection after bilateral breast reduction in the Dominican Republic; she experienced progressive deformity of her left breast until the causative pathogen was identified 20 months after her initial surgery. To assist in the timely diagnosis and treatment of these infections, we aim to promote greater awareness among physicians who are likely to encounter such patients. We present the pathologic findings of a review of 7 cases of RG-NTM infections seen at NewYork-Presbyterian Hospital/Columbia University Medical Center and discuss the diagnostic and therapeutic challenges associated with these infections, such as prolonged incubation periods, the need for acid-fast stains and mycobacterial cultures, and the combination of surgical therapy and lengthy antibiotic courses that are often required for treatment.

Rapidly growing Mycobacterium infections after cosmetic surgery in medical tourists: the Bronx experience and a review of the literature

BACKGROUND

Medical tourism is increasingly popular for elective cosmetic surgical procedures. However, medical tourism has been accompanied by reports of post-surgical infections due to rapidly growing mycobacteria (RGM). The authors' experience working with patients with RGM infections who have returned to the USA after traveling abroad for cosmetic surgical procedures is described here.

METHODS

Patients who developed RGM infections after undergoing cosmetic surgeries abroad and who presented at the Montefiore Medical Center (Bronx, New York, USA) between August 2015 and June 2016 were identified. A review of patient medical records was performed.

RESULTS

Four patients who presented with culture-proven RGM infections at the sites of recent cosmetic procedures were identified. All patients were treated with a combination of antibiotics and aggressive surgical treatment.

CONCLUSIONS

This case series of RGM infections following recent cosmetic surgeries abroad highlights the risks of medical tourism. Close monitoring of affected patients by surgical and infectious disease specialties is necessary, as aggressive surgical debridement combined with appropriate antibiotic regimens is needed to achieve cure. Given the increasing reports of post-surgical RGM infections, consultants should have a low threshold for suspecting RGM, as rapid diagnosis may accelerate the initiation of targeted treatment and minimize morbidity.

Infections caused by Mycobacterium abscessus: epidemiology, diagnostic tools and treatment

INTRODUCTION

Mycobacterium abscessus is an emerging mycobacteria that is responsible for lung diseases and healthcare-associated extrapulmonary infections. Recent findings support its taxonomic status as a single species comprising 3 subspecies designated abscessus, bolletii and massiliense. We performed a review of English-language publications investigating all three of these subspecies. Areas covered: Worldwide, human infections are often attributable to environmental contamination, although the isolation of M. abscessus in this reservoir is very rare. Basic research has demonstrated an association between virulence and cell wall components and cording, and genome analysis has identified gene transfer from other bacteria. The bacteriological diagnosis of M. abscessus is based on innovative tools combining molecular biology and mass spectrometry. Genotypic and phenotypic susceptibility testing are required to predict the success of macrolide (clarithromycin or azithromycin)-based therapeutic regimens. Genotyping methods are helpful to assess relapse and cross-transmission and to search for a common source. Treatment is not standardised, and outcomes are often unsatisfactory. Expert commentary: M. abscessus is still an open field in terms of clinical and bacteriological research. Further knowledge of its ecology and transmission routes, as well as host-pathogen interactions, is required. Because the number of human cases is increasing, it is also necessary to identify more active treatments and perform clinical trials to assess standard effective regimens.

A Cluster ofMycobacterium wolinskyiSurgical Site Infections at an Academic Medical Center

Objective

To study a cluster ofMycobacterium wolinskyisurgical site infections (SSIs).

Design

Observational and case-control study.

Setting

Academic hospital.

Patients.

Subjects who developed SSIs withM. wolinskyifollowing cardiothoracic surgery.

Methods

Electronic surveillance was performed for case finding as well as electronic medical record review of infected cases. Surgical procedures were observed. Medical chart review was conducted to identify risk factors. A case-control study was performed to identify risk factors for infection; Fisher exact or Kruskal-Wallis tests were used for comparisons of proportions and medians, respectively. Patient isolates were studied using pulsed-field gel electrophoresis (PFGE). Environmental microbiologic sampling was performed in operating rooms, including high-volume water sampling.

Results

Six definite cases ofM. wolinskyiSSI following cardiothoracic surgery were identified during the outbreak period (October 1, 2008–September 30, 2011). Having cardiac surgery in operating room A was significantly associated with infection (odds ratio, 40;P= .0027). Observational investigation revealed a cold-air blaster exclusive to operating room A as well a microbially contaminated, self-contained water source used in heart-lung machines. The isolates were indistinguishable or closely related by PFGE. No environmental samples were positive forM. wolinskyi.

Conclusions

No single point source was established, but 2 potential sources, including a cold-air blaster and a microbially contaminated, self-contained water system used in heart-lung machines for cardiothoracic operations, were identified. Both of these potential sources were removed, and subsequent active surveillance did not reveal any further cases ofM. wolinskyiSSI.

Infect Control Hosp Epidemiol2014;35(9):1169-1175

Characterization of Mycobacterium Abscessus Subtypes in Shanghai of China: Drug Sensitivity and Bacterial Epidemicity as well as Clinical Manifestations

The aim of the study was to investigate the epidemic characteristics of Mycobacterium abscessus in Shanghai.Fifty-five strains from 55 M. abscessus pulmonary disease patients were isolated. Drug sensitivity was measured by a broth microdilution method. Subtypes of M. abscessus were identified by DNA sequencing. Multilocus sequence typing (MLST), mining spanning tree (MST), and pulsed-field gel electrophoresis (PFGE) were used to analyze sequence types (ST) and clonal complexes (CC). Clinical manifestations were assessed by CT imaging.We identified 42 A isolates, 11 M, and 2 B-subtypes. A and M were highly sensitive to tigecycline and amikacin (97.6-100%). The A-type easily developed drug resistance against clarithromycin. Both types were highly resistance to sulfonamides, moxifloxacin, doxycycline, imipenem, and tobramycin. MLST analysis identified 41 STs including 32 new STs. The MST algorithm distributed 55 isolates into 12 separate CC. The PFGE analysis exhibited 53 distinct restriction patterns and the M-type was closely clustered according to their ST and CC numbers. CT imaging showed that tree-in-bud and patch shadow were commonly observed in M-type, whereas pulmonary cavities were often found in A-type infection patients (P < 0.001).ST1 in A and ST23 in M-type were the main epidemic strains in Shanghai. The M-type appeared to be prone to epidemic nosocomial transmission.

Management of Mycobacterium abscessus post abdominoplasty

Atypical mycobacterium is the source of a recent outbreak of cosmetic surgery infections [1]. Such an infection is difficult to eradicate and presents unique challenges in its management after esthetic surgery. Delays in appropriate treatment are frequent because of difficulty in diagnosis and unfamiliarity with this type of infection. We present cases of our management of Mycobacterial abscessus abdominoplasty infections following cosmetic surgery in the Dominican Republic. Rapid initial recognition of this problem and the frequent need for surgical treatment of atypical mycobacterium abdominoplasty infection may aid in the treatment of this rare but increasingly encountered infection.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Bronchopleural fistula following M. abscessus infection 11 years after lobectomy for lung cancer

Bronchopleural fistula (BPF) is a potentially fatal complication of lung cancer resection surgery that occurs during the healing process of the bronchial stump. However, the vulnerability of the healed surgical wound to overlapping acquired airway destruction has not yet been determined in detail. We herein present a case of fatal BPF following Mycobacterium abscessus (M. abscessus) infection, which occurred 11 years after right upper lobectomy for lung cancer. The findings of the present study suggest that patients with M. abscessus pulmonary disease in which airway destruction is progressing towards the bronchial stump of previous lobectomy should be considered for early completion pneumonectomy to prevent fatal BPF.

Extrapulmonary infections caused by a dominant strain of Mycobacterium massiliense (Mycobacterium abscessus subspecies bolletii)

A single strain of Mycobacterium massiliense (BRA 100), a subspecies of the Mycobacterium abscessus complex, has been responsible for an epidemic of post-surgical infections in Brazil. Outside Brazil, this is the first report to describe a single emerging strain of M. massiliense (TPE 101) associated with extrapulmonary infections. This phenomenon may be underestimated because sophisticated molecular typing of M. abscessus is not routinely performed. Our molecular epidemiology study was triggered by an outbreak investigation. Nine case isolates were grown from the surgical sites of nine mostly paediatric patients receiving operations from 2010 to 2011. All available non-duplicated isolates of M. abscessus during this period were obtained for comparison. Mycobacteria were characterized by multilocus sequence analysis (MLSA), repetitive sequence PCR (rep-PCR) and pulsed-field gel electrophoresis (PFGE). Of 58 isolates of M. abscessus overall, 56 were clinical isolates. MLSA identified 36 of the isolates as M. massiliense. All case isolates were indistinguishable by PFGE and named the TPE 101 pulsotype. Of the stored strains of M. abscessus, TPE 101 strains were over-represented among the control surgical wound (7/7, 100%) and subcutaneous tissue isolates (4/5, 80%) but rare among the respiratory isolates (1/16, 6%) and absent from external skin, ocular and environmental samples. In conclusion, a unique strain of M. massiliense has emerged as a distinctive pathogen causing soft tissue infections in Taiwan. Further study to identify whether this is due to an occult common source or to specific virulence factors dictating tissue tropism is warranted.

Clinical and microbiological differences between Mycobacterium abscessus and Mycobacterium massiliense lung diseases

In recent years, many novel nontuberculous mycobacterial species have been discovered through genetic analysis. Mycobacterium massiliense and M. bolletii have recently been identified as species separate from M. abscessus. However, little is known regarding their clinical and microbiological differences in Japan. We performed a molecular identification of stored M. abscessus clinical isolates for further identification. We compared clinical characteristics, radiological findings, microbiological findings, and treatment outcomes among patients with M. abscessus and M. massiliense lung diseases. An analysis of 102 previous isolates of M. abscessus identified 72 (71%) M. abscessus, 27 (26%) M. massiliense, and 3 (3%) M. bolletii isolates. Clinical and radiological findings were indistinguishable between the M. abscessus and M. massiliense groups. Forty-two (58%) patients with M. abscessus and 20 (74%) patients with M. massiliense infections received antimicrobial treatment. Both the M. abscessus and M. massiliense groups showed a high level of resistance to all antimicrobials, except for clarithromycin, kanamycin, and amikacin. However, resistance to clarithromycin was more frequently observed in the M. abscessus than in the M. massiliense group (16% and 4%, respectively; P = 0.145). Moreover, the level of resistance to imipenem was significantly lower in M. abscessus isolates than in M. massiliense isolates (19% and 48%, respectively; P = 0.007). The proportions of radiological improvement, sputum smear conversion to negativity, and negative culture conversion during the follow-up period were higher in patients with M. massiliense infections than in those with M. abscessus infections. Patients with M. massiliense infections responded more favorably to antimicrobial therapy than those with M. abscessus infections.

Evaluation of a low-cost calorimetric approach for rapid detection of tuberculosis and other mycobacteria in culture

AIMS

The objective of this study was to evaluate the effectiveness of microcalorimetry in rapid detection of mycobacterium species using an inexpensive Isothermal microcalorimetry (IMC) instrument. In addition, we compared microcalorimetry with conventional monitoring techniques.

METHODS AND RESULTS

Isothermal microcalorimetry measures heat production rate and can provide rapid detection of living mycobacteria in clinical specimens. Using liquid medium showed that bacterial activity measured by IMC using a TAM Air® agreed with the triphenyl tetrazolium chloride (TTC) assay. Using solid medium to enhance growth, fast-growing mycobacteria detection was achieved between 26 and 53 h and slow-growing mycobacteria detection was achieved between 54 and 298 h. In addition, the calorimetric data were analysed to estimate the growth rate and generation time of the mycobacteria monitored.

SIGNIFICANCE AND IMPACT OF THE STUDY

Infections caused by mycobacteria are severe and difficult to treat. With 9·27 million new cases of tuberculosis in 2007, developing countries experience severe health and economic consequences owing to the lack of an affordable, fast detection method. Research-grade IMC instruments are too expensive to use in developing countries. Our study demonstrates that less-expensive instruments such as the TAM air® are adequate for mycobacteria detection and therefore establishes a clear proof of concept.

Clarithromycin and amikacin vs. clarithromycin and moxifloxacin for the treatment of post-acupuncture cutaneous infections due to Mycobacterium abscessus: a prospective observational study

An outbreak of post-acupuncture cutaneous infections due to Mycobacterium abscessus occurred in Ansan, Korea, from November 2007 through to May 2008. During this time a prospective, observational, non-randomized study was conducted involving 52 patients that were diagnosed with cutaneous M. abscessus infection. We compared the clinical response between patients treated with clarithromycin plus amikacin regimen and those treated with clarithromycin plus moxifloxacin regimens with regard to time to resolution of the cutaneous lesions. Among the 52 study patients, 33 were treated with clarithromycin plus amikacin, and 19 were treated with clarithromycin plus moxifloxacin. The baseline characteristics for the treatment groups were not significantly different, except for initial surgical excision (n = 27 vs. 6, respectively, p = 0.001). The median time (weeks) to resolution of the lesions in the clarithromycin plus moxifloxacin-treated subjects was significantly shorter than that in the clarithromycin plus amikacin-treated subjects (17 ± 1.1 vs. 20 ± 0.9, respectively, p = 0.017). With adjustments for age, location of lesions, prior incision and drainage, and excision during medical therapy, clarithromycin plus moxifloxacin-treated subjects were more likely to have resolved lesions (hazard ratio, 0.387; 95% confidence interval, 0.165-0.907; p = 0.029). The frequency of drug-related adverse events in the two treatment groups was not significantly different (n = 18 vs. 14, respectively; p = 0.240). The most common adverse event was gastrointestinal discomfort. The results of our study showed that the combination regimen of clarithromycin and moxifloxacin resulted in a better clinical response than a regimen of clarithromycin plus amikacin when used for treatment of cutaneous M. abscessus infection.

An unusual surgical site infection in a liver transplant recipient

Mycobacterium abscessus is a rare cause of human infection and is difficult to diagnose unless it is suspected. A 45-year-old woman underwent deceased donor liver transplantation following which she developed non-healing surgical site infection, which did not resolve with routine antibiotics for 2 months. The scraping of the wound revealed M abscessus infection. Definitive identification of this species of mycobacterium was possible by its growth characteristics on culture and reverse line blot hybridisation assay. She was treated with clarithromycin and cotrimaxazole as per sensitivity and showed complete recovery from the infection within 6 weeks of starting the drugs, which were continued for 6 months. We believe that this is the first documented case of surgical site infection by M abscessus in a liver transplant recipient.

Non tuberculous mycobacteria in surgical wounds- a rising cause of concern?

INTRODUCTION

The non-tuberculous mycobacteria (NTM) have emerged as important opportunistic pathogens in the recent years. The NTM are rapid growing mycobacteria (RGM), which include Mycobacterium fortuitum and M. chelonae and are grouped as M. fortuitum-chelonae complex. Non-healing postoperative wound infections that do not respond to antibiotics used for pyogenic infections and having sterile routine aerobic cultures should raise a suspicion of NTM.

PATIENTS AND METHODS

All patients with post operative wound infection over a five year period were included in the study. All wound infections were evaluated with wound culture and sensitivity and treated with appropriate antibiotics. All infections with underlying mesh were initially managed with dressings/debridement, long term antibiotics. Explantation of the mesh was to be used as a last resort.

RESULTS

We analyzed the records of patients with post operative wound infections who had wound cultures taken and found that 16 of our patients had initial sterile cultures. In all these cases, wound infection manifested itself as discharging sinuses between 2-3 weeks after surgery. Of these seven patients grew NTM on their repeat cultures. The commonest organism isolated was M. fortuitum (57%). The commonest antibiotic used for treatment was Tab Clarithromycin and the mean duration of treatment was 6 to 9 months. No patients required debridement or removal of mesh.

DISCUSSION

NTM infections in post operative wound though rare should be suspected in all post operative wound infections which occurs late, lack local and systemic signs of pyogenic infections and have sterile cultures. High index of suspicion for NTM infection will allow identification and treatment of these patients with long-term antimicrobial therapy alone without the need for surgical explantation of the mesh.

Structural analysis of biofilm formation by rapidly and slowly growing nontuberculous mycobacteria

Mycobacterium avium complex (MAC) and rapidly growing mycobacteria (RGM) such as M. abscessus, M. mucogenicum, M. chelonae, and M. fortuitum, implicated in health care-associated infections, are often isolated from potable water supplies as part of the microbial flora. To understand factors that influence growth in their environmental source, clinical RGM and slowly growing MAC isolates were grown as biofilm in a laboratory batch system. High and low nutrient levels were compared, as well as stainless steel and polycarbonate surfaces. Biofilm growth was measured after 72 h of incubation by enumeration of bacteria from disrupted biofilms and by direct quantitative image analysis of biofilm microcolony structure. RGM biofilm development was influenced more by nutrient level than by substrate material, though both affected biofilm growth for most of the isolates tested. Microcolony structure revealed that RGM develop several different biofilm structures under high-nutrient growth conditions, including pillars of various shapes (M. abscessus and M. fortuitum) and extensive cording (M. abscessus and M. chelonae). Although it is a slowly growing species in the laboratory, a clinical isolate of M. avium developed more culturable biofilm in potable water in 72 h than any of the 10 RGM examined. This indicates that M. avium is better adapted for growth in potable water systems than in laboratory incubation conditions and suggests some advantage that MAC has over RGM in low-nutrient environments.

Retroperitoneal cold abscess caused by mycobacteria chelonae abscessus after percutaneous nephrolithotomy in India: strategies for detection, management, and prevention in the United States

Atypical, nontuberculous, mycobacteria (NTM) are emerging as significant pathogens in nosocomial infections. Historically, such outbreaks have been limited to developing countries, and clinicians in the United States have not been exposed to the nuances of diagnosing and treating such infections. With an increasing prevalence worldwide, all clinicians should be able to recognize and treat NTM infections. We report a case of a patient who developed a retroperitoneal cold abscess caused by NTM after percutaneous stone surgery in India. Through a comprehensive review of published reports, we offer strategies for the treatment and prevention of such outbreaks.

Atypische Mykobakteriose der Haut durch Mycobacterium abscessus bei einer immunkompetenten Frau

Mycobacterium abscessus is the most pathogenic of the fast-growing mycobacteria, and it is resistant to most of the antimicrobial and tuberculostatic drugs available. This non-tuberculous mycobacterium is significant in medicine because it can contaminate post-traumatic wounds and be a causative agent in chronic skin and soft tissue infection after surgical procedures.A 60-year-old immunocompetent woman was suffering from chronic ulcers and abscesses on the heels and malleoli of both feet. Histological examination revealed a granulomatous inflammation with detection of acid-fast rods, albeit without fibrinoid necrosis. The repeated detection of atypical mycobacteria, which were ultimately identified as Mycobacterium abscessus, allowed the diagnosis of an atypical mycobacteriosis of the skin. This was successfully treated first with clarithromycin and rifabutin and later with a combination of ethambutol, minocycline, clofazimine and azithromycin.

Mycobacterium abscessus keratitis after LASIK with IntraLase femtosecond laser

A healthy 38-year-old woman developed 2 white spots in her left eye 2 weeks after bilateral laser in situ keratomileusis (LASIK) using the IntraLase femtosecond laser. Initial treatment included levofloxacin 0.5% but was unsuccessful. The surgeon irrigated the interface and repositioned the flap due to a worsened lesion. She was referred to us after the keratitis had not improved. The flap was lifted for collection of the specimen and irrigation of the interface. The keratitis was treated with intensive topical clarithromycin 1%, amikacin 1.25% and oral clarithromycin, which improved her clinical condition. She developed a toxic reaction to amikacin 1.25%, which was replaced by moxifloxacin 0.5%. Mycobacterium abscessus was identified. The keratitis resolved over 2 months. Five months after treatment, the patient had a visual acuity of 20/20 with correction. Nontuberculous mycobacteria should be considered as an etiologic agent, even in cases of infectious keratitis after LASIK using the femtosecond laser.

Cutaneous Infection with Mycobacterium abscessus in a child

Nontuberculous mycobacteria can cause cutaneous infections in both children and adults. Localized nontuberculous mycobacterial infections of the skin have been reported in children following injections or surgical procedures. We report a child who developed a cutaneous nontuberculous mycobacterial infection after exposure of a skin wound to pond water. Cutaneous infection with the rapidly growing mycobacteria Mycobacterium abscessus was demonstrated by clinical and histologic evaluation on the lower leg of an otherwise healthy 12-year-old Caucasian boy. We describe this as an instance of an unusual acquisition of cutaneous M. abscessus infection in a child.

An outbreak of post-acupuncture cutaneous infection due to Mycobacterium abscessus

Background

Despite the increasing popularity of acupuncture, the importance of infection control is not adequately emphasized in Oriental medicine. In December 2001, an Oriental medical doctor in Seoul, South Korea, encountered several patients with persistent, culture-negative skin lesions on the trunk and extremities at the sites of prior acupuncture treatment. We identified and investigated an outbreak of Mycobacterium abscessus cutaneous infection among the patients who attended this Oriental medicine clinic.

Methods

Patients were defined as clinic patients with persistent cutaneous infections at the acupuncture sites. Medical records for the previous 7 months were reviewed. Clinical specimens were obtained from the patients and an environmental investigation was performed. M. abscessus isolates, cultured from patients, were compared by pulsed-field gel electrophoresis (PFGE).

Results

Forty patients who attended the Oriental medicine clinic and experienced persistent cutaneous wound infections were identified. Cultures from five of these patients proved positive, and all other diagnoses were based on clinical and histopathologic examinations. All environmental objects tested were negative for M. abscessus, however, most were contaminated by various nosocomial pathogens. Molecular analysis using PFGE found all wound isolates to be identical.

Conclusion

We have identified a large outbreak of rapidly growing mycobacterial infection among patients who received acupuncture at a single Oriental medicine clinic. Physicians should suspect mycobacterial infections in patients with persistent cutaneous infections following acupuncture, and infection control education including hygienic practice, should be emphasized for Oriental medical doctors practicing acupuncture.

Iatrogenic Mycobacterium abscessus infection associated with acupuncture: clinical manifestations and its treatment

BACKGROUND

Mycobacterial infections transmitted by acupuncture are an emerging problem. There have been two reports of mycobacterial infections complicating acupuncture in the English literature.

AIM

To describe the clinical manifestations and treatment of patients who acquired localized Mycobacterium abscessus infection in the process of acupuncture.

METHODS

Clinical manifestations and responses to different methods of treatment were reviewed in 40 patients who developed various skin lesions after acupuncture at a Korean oriental medicine clinic. Results The morphology of the lesions which developed at the acupuncture sites varied. Although the lesions disappeared with the combined administration of clarithromycin and amikacin for 3 months in most cases, five out of 25 patients (20%) showed residual lesions at the end of treatment, and had to be treated with a higher dosage of clarithromycin or alternative antibiotics based on sensitivity tests.

CONCLUSIONS

We recommend at least 3 months of treatment with clarithromycin for treating skin infections caused by M. abscessus, with supplementary antibiotics selected based on patients' drug sensitivity tests.

Mycobacteria in drinking water distribution systems: ecology and significance for human health

In contrast to the notorious pathogens Mycobacterium tuberculosis and M. leprae, the majority of the mycobacterial species described to date are generally not considered as obligate human pathogens. The natural reservoirs of these non-primary pathogenic mycobacteria include aquatic and terrestrial environments. Under certain circumstances, e.g., skin lesions, pulmonary or immune dysfunctions and chronic diseases, these environmental mycobacteria (EM) may cause disease. EM such as M. avium, M. kansasii, and M. xenopi have frequently been isolated from drinking water and hospital water distribution systems. Biofilm formation, amoeba-associated lifestyle, and resistance to chlorine have been recognized as important factors that contribute to the survival, colonization and persistence of EM in water distribution systems. Although the presence of EM in tap water has been linked to nosocomial infections and pseudo-infections, it remains unclear if these EM provide a health risk for immunocompromised people, in particular AIDS patients. In this regard, control strategies based on maintenance of an effective disinfectant residual and low concentration of nutrients have been proposed to keep EM numbers to a minimum in water distribution systems.

Mycobacterium fortuitum: an iatrogenic cause of soft tissue infection in surgery

BACKGROUND

Mycobacterium fortuitum is an uncommon cause of soft tissue infections. Treatment is often inadequate with persistence of infection unless the aetiological agent and its antibiotic sensitivity are accurately established.

METHODS

Medical records of 23 patients with chronic soft tissue infection caused by M. fortuitum over a 12-year period from 1991 to 2002 were studied.

RESULTS

In 20 patients the cause was iatrogenic, following intramuscular injections (12), laparoscopy (5) and other surgical procedures (3) and in three patients discharging sinuses developed spontaneously. Patients presented with recurrent abscesses or chronic discharging sinuses that did not respond to conventional surgical drainage. The diagnosis was established by isolating M. fortuitum from the tissues in all cases. The treatment consisted of a more aggressive surgical intervention in form of excision, debridement and extensive lay open with curettage and prolonged administration of appropriate antibiotics. The organism showed maximum sensitivity to amikacin and ciprofloxacin. Healing occurred in all cases. Three patients suffered recurrences: two responded to further debridement and antibiotics and are well at 2 and 5 years, respectively.

CONCLUSION

A high index of suspicion based on clinical presentation is essential to diagnose M. fortuitum as a cause of soft tissue infection. Treatment involves aggressive surgical debridement and administration of combination antibiotics based on sensitivity, which should be continued for a period that will ensure complete healing and prevent recurrence.

Mycobacterium canariasense sp. nov

A novel rapidly growing, non-pigmented mycobacterium was isolated from blood samples obtained from 17 patients with febrile syndrome. Bacterial growth occurred at 30 and 37 °C on Löwenstein–Jensen medium and also on MacConkey agar without crystal violet. Strains contained α- and α′-mycolates in their cell wall. Sequence analysis of the hsp65 and 16S rRNA genes identified the isolates as rapidly growing mycobacteria. Sequences of both genes were unique within the mycobacteria. DNA–DNA hybridization showed that the isolates had less than 15 % reassociation with 13 other recognized rapidly growing mycobacteria. The name Mycobacterium canariasense sp. nov. is proposed for this novel opportunistic pathogen, which is most closely related to Mycobacterium diernhoferi. The type strain is 502329T (=CIP 107998T=CCUG 47953T).

Mycobacterium abscessus cellulitis and multifocal abscesses of the breasts in a transsexual from illicit intramammary injections of silicone

We report the case of a 29-year-old transsexual who developed Mycobacterium abscessus infection after receiving intramammary liquid silicone injections in the nonphysician office setting. Our patient represents 1 of 14 confirmed and 11 suspected cases in New York City of M abscessus infection after illicit cosmetic procedures. As injectable cosmetic procedures are becoming increasingly popular, dermatologists should be aware of both the common and unusual complications. Furthermore, all physicians should be alerted to the current cluster of M abscessus infections after injections for cosmetic purposes by nonmedical practitioners in New York City.

Radiographic and CT findings of nontuberculous mycobacterial pulmonary infection caused by Mycobacterium abscessus

OBJECTIVE

The purpose of our study was to describe the radiographic and CT findings in patients with pulmonary infections caused by Mycobacterium abscessus, one of the more common rapidly growing nontuberculous mycobacteria that cause lung disease.

CONCLUSION

The main radiologic and CT manifestations of M. abscessus lung infection are bilateral small nodular opacities, bronchiectasis, and cavity formation.

Unusual infectious complications of dermatologic procedures

Because dermatologic procedures disrupt skin integrity, they alter the body's protective barrier and predispose individuals to cutaneous infection. Postoperative wound infections--even with common pathogens such as S. aureus--seldom complicate dermatologic procedures; however, unusual infections have been reported to complicate excisions, biopsies, skin grafts, chemical peels, dermabrasion, laser resurfacing, liposuction, blepharoplasty, and injections (eg, with anesthetic solutions or botulinum toxin). Numerous environmental and patient risk factors increase the rate of postoperative wound infections, but otherwise healthy individuals undergoing relatively simple procedures are sometimes affected. Obtaining a thorough patient, history (including history of prior HSV infection or any immunocompromising factors) is crucial. Patients should be warned of potential complications, particularly when they are undergoing cosmetic procedures. It is important to maintain a high index of suspicion for possible wound infection in all patients that extends several months postoperatively. Manifestations of unusual postoperative infections are highly variable, and they might be secondary to bacterial, fungal, viral, or parasitic pathogens. Bacterial lesions are often polymicrobial, and bacterial superinfection can exacerbate other wound complications such as HSV reactivation. Most wound infections remain localized, but occasionally systemic disease occurs. For example, cutaneous diphtheria or rapidly growing mycobacteria rarely disseminate, whereas TSS results in systemic disease caused by toxin release. Some unusual postsurgical infections are self-limited, but they can still be potentially life threatening or disfiguring. Antimicrobial prophylaxis might reduce the risk of wound infection in some cases. Clinicians can better care for patients by becoming familiar with the causes and clinical manifestations of unusual dermatologic postoperative wound infections (Table 1). Following the recognition of an infectious process, appropriate diagnostic procedures allow for pathogen identification and the prompt institution of indicated therapy.

The genetics of nontuberculous mycobacterial infection

The molecular aetiology of familial susceptibility to disseminated mycobacterial disease, usually involving weakly pathogenic strains of mycobacteria, has now been elucidated in more than 30 families. Mutations have been identified in five genes in the interleukin-12-dependent interferon-gamma pathway, highlighting the importance of this pathway in human mycobacterial immunity. Knowledge derived from the study of these rare patients contributes to our understanding of the immune response to common mycobacterial pathogens such as Mycobacterium tuberculosis and Mycobacterium leprae, which remain major public health problems globally. This knowledge can be applied to the rational development of novel therapies and vaccines for these important mycobacterial diseases.

An outbreak of Mycobacterium chelonae infection after LASIK

OBJECTIVE

To describe an outbreak of mycobacterial keratitis after laser in situ keratomileusis (LASIK), including the microbiologic investigation, clinical findings, treatment response, and outcome.

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Patients (n = 10) who underwent LASIK surgery between August 22 and September 4, 2000, and developed mycobacterial infection.

METHODS

Patients were prospectively followed in relation to microbiologic investigation, clinical findings, treatment response, and outcome.

MAIN OUTCOME MEASURES

Most patients underwent bilateral simultaneous LASIK. Postoperative infection was signaled by the appearance of corneal infiltrates in the third postoperative week. The microbiologic workup was performed on cultures obtained either by direct scraping of the cornea or by lifting the flap. Medical therapy was instituted based on drug susceptibility testing. Surgical interventions such as corneal debridement and flap removal were performed during recurrences or when there was no satisfactory clinical response.

RESULTS

Cultures revealed Mycobacterium subspecies chelonae. Patients were treated with topical clarithromycin (1%), tobramycin (1.4%), and ofloxacin (0.3%). Oral clarithromycin (500 mg twice a day) was prescribed for those patients who did not respond clinically to topical treatment. Four eyes healed on this regimen. Flap removal was necessary in seven eyes.

CONCLUSIONS

This report highlights mycobacteria as an etiologic infectious agent after LASIK. Diagnosis can be difficult and is often delayed. The treatment mainstay is prolonged antibiotic therapy. Surgical debridement and flap removal may shorten the disease course.

A polymorphic region in Mycobacterium abscessus contains a novel insertion sequence element

A polymorphic region was discovered in the genetically uncharacterized opportunistic pathogen Mycobacterium abscessus. The region contains a novel 1.7 kb insertion sequence (IS) named ISMab1. ISMab1 contains two complete ORFs and one partial ORF located in segments with over 80% nucleotide identity to Mycobacterium avium IS1601 and IS999 and to previously unreported IS-like elements from Mycobacterium smegmatis. The marked similarity within this family of elements is supportive of horizontal transfer between environmental mycobacterial species. In clinical isolates, ISMab1 was either present as a single copy or absent. The polymorphic region containing ISMab1 was identified by genomic subtraction between a parental strain and phenotypic variant. The variant has a 14.2 kb genomic deletion and this is flanked in the parental strain by complex arrays of inverted and direct repeats. Clinical isolates of M. abscessus were probed for the deletion and flanking sequences and two were found to be missing more than 20 kb. No regional deletions were found in the type strain, ATCC 19977. Although M. abscessus is a rapidly growing species, comparative sequence analysis of 23 kb from the polymorphic region showed that most local ORFs have greater amino acid identity to proteins encoded by genes from the slowly growing mycobacteria, M. avium and Mycobacterium tuberculosis, than to the rapid-grower M. smegmatis. Several ORFs also have strong similarity to Pseudomonas aeruginosa genes with a potential role in beta-oxidation.