Catheter-related bloodstream infections caused by rapidly growing nontuberculous mycobacteria: a case series including rare species

Nontuberculous mycobacterial infections in patients with hematologic malignancies and recipients of hematopoietic stem cell transplantation

BACKGROUND

The incidence of mycobacterial infections in patients with hematologic malignancies and hematopoietic stem cell transplant (HSCT) recipients is increasing, contributing to significant mortality and morbidity. This review explores the epidemiology, risk factors, clinical presentation, diagnosis, and treatment of nontuberculous mycobacteria (NTM) in this population.

METHODS

A literature search was performed using PubMed with keywords and MeSH terms pertaining to the topics of nontuberculous mycobacteria, hematologic malignancies, hematopoietic stem cell transplant, cellular therapies, chimeric antigen therapies, epidemiology, diagnosis, and treatment. Additionally, we examined the reference lists of the included articles to identify other pertinent studies.

RESULTS

Diagnosing mycobacterial disease among patients with hematologic disease and treatment-associated immunosuppressive conditions is challenging due to the lack of distinctive clinical, radiographic, and laboratory markers, as well as the atypical manifestations compared to immunocompetent patients. Treatment involves using a combination of antibiotics for extended durations, coupled with strategies to achieve source control and reduce immunosuppression when feasible. This is complicated by the absence of clear data correlating in-vitro drug susceptibility and clinical outcome for many antimicrobials use to treat NTM, adverse drug-drug interactions, and the frequent challenges related to poor medication tolerability and toxicities.

CONCLUSION

The rising incidence and corresponding clinical challenges of mycobacterial infections in this unique patient population necessitate a heightened awareness and familiarity of NTM disease by clinicians to achieve timely diagnosis and favorable treatment outcomes.

Disseminated nontuberculous mycobacteria infection in an immunocompetent host: A case report

RATIONALE

Disseminated nontuberculous mycobacterial (NTM) infections are rare and occur primarily in immunocompromised hosts. Mycobacterium abscessus complex (MABC), including M abscessus subsp. massiliense (hereafter M massiliense) is a complex of rapidly growing mycobacterial (RGM) species of NTM. Here, we present a rare case of disseminated NTM infection with RGM bacteremia caused by M massiliense in an immunocompetent host.

PATIENT CONCERNS

A 64-year-old woman with a recent history of spine fracture and septic pneumonia was transferred to our emergency room for dyspnea and fever. A peripherally inserted central catheter (PICC) had been placed over 6 months prior.

DIAGNOSES

Chest computed tomography (CT) showed multifocal patchy consolidations and ground-glass opacity in both lungs. NTM suspected of RGM was isolated from the blood cultures. During hospitalization, multiple erythematous and hemorrhagic crusted nodules developed on the patient's upper and lower extremities, which were confirmed as disseminated NTM infection on skin biopsy.

INTERVENTIONS

After NTM suspected of RGM was isolated from the blood cultures, the patient was empirically treated with antibiotics used for NTM infection, and the PICC was removed. Thereafter, the subspecies of NTM was reported as M massiliense and she was treated according to the antibiotic susceptibility testing results.

OUTCOME

Although skin lesions and inflammatory markers improved gradually during antibiotic treatment over 10 weeks, NTM could still be isolated from the blood culture.

LESSONS

Disseminated NTM infections with RGM bacteremia in an immunocompetent host have rarely been reported. In this case, PICC placement for more than 6 months was suspected to be an important risk factor for RGM bacteremia in an immunocompetent patient. To date, there are only insufficient case reports, moreover no clear guidelines regarding the optimal choice of antibiotics or length of treatment for disseminated NTM infection. Therefore, it is necessary to establish treatment guidelines for patients with disseminated NTM infection and bacteremia.

Catheter-related bloodstream Mycobacterium wolinskyi infection in an umbilical cord blood transplant recipient: a case report

Background

Catheter-related bloodstream infection (CRBSI), caused by rapidly growing mycobacteria (RGM), is a rare infectious complication in hematopoietic stem cell transplant (HSCT) recipients and can often be misdiagnosed as Gram-positive rod (GPR) bacteremia.

Case presentation

We present a case of CRBSI caused by Mycobacterium wolinskyi, a rare RGM, in a 44-year-old female patient who received an umbilical cord blood transplant.

Conclusions

Rapidly growing mycobacteria can stain as GPRs and may grow in routine blood culture media after 3–4 days of incubation. These features are not widely known to clinicians, and acid-fast staining is therefore recommended when unidentifiable GPRs are detected in blood cultures, especially in immunocompromised patients, such as those with hematologic malignancies or intravascular devices.

NonTuberculous Mycobacteria Blood Stream Infection in Pediatric and Adult Patients: 15 Years Surveillance

BACKGROUND

Nontuberculous Mycobacteria (NTM) are rare causes of bloodstream infection (BSI). This study addresses the management and prognosis of NTM BSI and the differences between adult and pediatric patients.

METHODS

We retrospectively reviewed the medical charts of patients at any age with NTM BSI, from January 1, 2005, to June 30, 2020. Data on demographics, underlying conditions, clinical manifestations, NTM species, antibiotic treatments and outcomes were retrieved.

RESULTS

Positive blood cultures for NTM were detected in 43 patients, 30 children and 13 adults. Median age: 10.37 years (IQR 6.692-39.864). Thirty-seven (86%) patients had an active malignant disease. Fever was the chief sign in 23 (53.5%) patients and pulmonary manifestations in 14 (32.6%). Rapidly growing NTM comprised 39 (90.7%) of the isolates. Central venous catheter (CVC) was documented in 39 (90.7%) cases, 31 (79.5%) of which were removed as part of treatment. Antibiotic treatment directed against NTM was documented in 26 (60.5%) patients. CVC was removed in 7/17 patients who were not treated with antibiotics. Relapse occurred in 3 cases; no 30-days mortality was reported. Children and adults had similar clinical characteristics. However, children had a higher rate of CVC at the time of bacteremia and a higher chance to receive treatment.

CONCLUSION

NTM BSI was seen mainly in oncologic patients with CVC. Children and adults had a similar disease course and outcome. Relapse was rare and NTM-related mortality was not reported.

Bloodstream infections with rapidly growing nontuberculous mycobacteria

Background

Bloodstream infections (BSI) with rapidly growing mycobacteria (RGM) resulted in recent nosocomial outbreaks predominantly in immunocompromised patients. A little is known about the clinical implications of RGM BSI with different species.

Methods

We conducted a multicenter retrospective cohort study of patients with RGM BSI from November 2011 to December 2020. Demographic data, clinical presentation, laboratory and radiographic findings and microbiological characteristics were used to tabulate descriptive statistics. We performed a comparative analysis of patients with BSI due to Mycobacterium abscessus complex (MABC) vs. other RGM.

Results

We identified 32 patients with positive blood cultures for RGM, 4/32 (12.5%) were considered to have unclear significance. The most common source for RGM BSI was intravascular catheters (14/28, 50%). Compared to other sources, patients with catheter-related bloodstream infection (CRBSI) received a shorter course of antimicrobial therapy (median [IQR]: one month [0.37–2.25] vs. six months [2–12]), (P = 0.01). The most common species isolated were MABC (12/28, 42.9%), followed by Mycobacterium fortuitum group (6/28, 21.4%) and Mycobacterium chelonae (6/28, 21.4%). Compared to other RGM, MABC BSI was more likely to be secondary to skin and soft tissue infection, associated with longer hospital stay (P = 0.04) and higher death rates despite a higher number of antimicrobial agents used for empirical and directed therapy per patient.

Conclusion

MABC BSI is associated with an overall more resistant profile, longer hospital stay, and higher death rate despite a more aggressive therapy approach.

Successful treatment of rapid growing mycobacterial infections with source control alone: Case series

Rapid growing mycobacteria have been increasingly recognized as pathogens, both in immunocompromised and immunocompetent population, and their incidence has increased over the last decade significantly. Pulmonary infections are the most common, however, any organ can be affected. The treatment of these infections is costly, prolonged, and often antimicrobial resistance poses a significant challenge to a successful outcome. The source control together with antimicrobials is the cornerstone of treatment. We report a case series of 3 patients with extrapulmonary rapid growing mycobacterial infections in whom the successful treatment was achieved with source control alone.

Approach to the diagnosis and treatment of non-tuberculous mycobacterial disease

Non-tuberculous mycobacteria (NTM) is a collective name given to a group of more than 190 species of Mycobacterium. The clinical presentation for most NTM infections is non-specific, often resulting in delayed diagnosis. Further complicating matters is that NTM organisms can be difficult to isolate. Medications used to treat NTM infection can be difficult for patients to tolerate, and prolonged courses of anti-mycobacterial therapy are often required for adequate suppression or eradication. Herein, we review different NTM syndromes, appropriate diagnostic tests, and treatment regimens.

Catheter-related blood stream infection caused by Mycobacterium chelonae in a child with myeloid leukemia associated with Down syndrome

Rapidly growing nontuberculous mycobacteria should be considered if GPRs gram-positive rods are detected in blood cultures 2-3 days after the blood sample collection.

Mycobacterium mucogenicum bacteremia in an immunocompetent host: A case report and concise review

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M. mucogenicum should be considered as a potential etiology of bacteremia in the setting of an inserted catheter, even in immunocompetent hosts.

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M. mucogenicum is one of the most common causes of rapidly growing mycobacterium bloodstream infection in patients with catheters in place.

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Catheter removal is critical in the management of patients with M. mucogenicum bacteremia since mycobacteria is notorious for biofilm formation.

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M. mucogenicum is naturally resistant to anti-tuberculous drugs.

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M. mucogenicum is susceptible to numerous antibiotics, making early recognition and diagnosis important to tailor appropriate therapy.

Rapidly growing mycobacterium (RGM) bloodstream infections (BSI) have been described in the literature mostly in immunocompromised patients such as those with malignancies. Here, we describe a case of a RGM, Mycobacterium mucogenicum, bloodstream infection in an immunocompetent host who was receiving antibiotics via a peripherally inserted central catheter (PICC).

Mycobacterium septicum: a 6-Year Clinical Experience from a Tertiary Hospital and Reference Laboratory

Mycobacterium septicum is a rarely identified nontuberculous mycobacterium capable of causing infections in both healthy and immunocompromised individuals. Only a few cases of M. septicum infections have been reported, which makes recognizing corresponding clinical disease more challenging for clinicians. Antimicrobial susceptibility profiles for this organism are not well described, and corresponding optimal therapeutic regimens have not been established. We report a tertiary care center's experience with M. septicum from 2014 to 2020. Twelve adult patients with positive cultures for M. septicum were identified. Most cases were identified from sputum samples of individuals with underlying lung disease. Most cases involving M. septicum isolation in culture were not felt to be clinically significant. Two cases were considered possible infections, while only one case was considered a definite infection that required antimicrobial treatment. All M. septicum isolates were susceptible in vitro to amikacin, ciprofloxacin, imipenem, linezolid, moxifloxacin, and trimethoprim-sulfamethoxazole. Isolates were universally resistant to clarithromycin and doxycycline. The isolation of M. septicum in culture is uncommon and requires clinical correlation to determine its clinical relevance and need for treatment. Susceptibility testing should be performed to guide therapy.

A case series of rapidly growing mycobacterial catheter-related bloodstream infections among immunocompetent patients

Rapidly growing mycobacteria (RGM) are ubiquitous in the environment and can cause a variety of human infections. Catheter-related bloodstream infections (CRBSI) caused by RGM have been reported predominantly among immunocompromised patients. Removal of central lines and antimicrobial therapy with at least 2 active agents are generally recommended for immunocompromised patients. RGM bloodstream infections (BSIs) are rare in immunocompetent patients and clinical data are very limited. Retrospective medical record review was conducted on patients with blood cultures positive for RGM from July 2012 through March 2015 at Lemuel Shattuck Hospital, a public teaching hospital in Jamaica Plain, Massachusetts, United States. RGM was suspected by presence of beaded Gram-positive bacilli on Gram staining of positive conventional blood cultures and it was confirmed as RGM by Massachusetts State Public Health Laboratory. Nineteen episodes of RGM BSI were identified in 17 patients who had no known immunocompromised conditions that predispose them to opportunistic pathogens. They were predominantly young male with history of intravenous drug use. Peripherally inserted central catheter (PICC) was present in all episodes of RGM BSI and 74% of them clinically improved with PICC removal alone without specific antibiotic therapy for RGM. They were followed up for median duration of 45 days (interquartile range 25–385). The patients remained alive and asymptomatic until the end of follow-up periods. In immunocompetent patients, removal of catheters alone without adding specific antibiotics may be sufficient for RGM CRBSI.

Mycobacterium mucogenicum skin and soft tissue infection of the breast mimicking idiopathic granulomatous mastitis

We present a case of a 28-year-old woman who came to medical attention after noticing a breast mass associated with an overlying eroded plaque of the skin. A core biopsy of the breast mass was negative for malignancy but demonstrated granulomatous inflammatory changes. Acid-fast bacilli and Gomori methenamine-silver stains were negative for microorganisms. The patient was diagnosed with presumptive idiopathic granulomatous mastitis and started on oral steroids. Her symptoms progressed. Tissue culture from a repeat biopsy grew Mycobacterium mucogenicum The patient responded well to combination oral antimicrobial therapy.

Healthcare-Associated Mycobacterium bovis-Bacille Calmette-Guérin (BCG) Infection in Cancer Patients Without Prior BCG Instillation

Background

Bacille Calmette-Guérin (BCG), an attenuated strain of Mycobacterium bovis, is widely used as adjunctive therapy for superficial bladder cancer. Intravesical administration of BCG has been associated with systemic infection. Disseminated infection due to M. bovis is otherwise uncommon.

Methods

After identification of 3 patients with healthcare-associated BCG infection who had never received intravesical BCG administration, an epidemiologic study was performed. All patients with healthcare-associated BCG infection in the Barcelona tuberculosis (TB) program were reviewed from 1 January 2005 to 31 December 2015, searching for infections caused by M. bovis-BCG. Patients with healthcare-associated BCG infection who had not received intravesical BCG instillation were selected and the source of infection was investigated.

Results

Nine oncology patients with infection caused by M. bovis-BCG were studied. All had permanent central venous catheters. Catheter maintenance was performed at 4 different outpatient clinics in the same room in which other patients underwent BCG instillations for bladder cancer without required biological precautions. All patients developed pulmonary TB, either alone or with extrapulmonary disease. Catheter-related infection was considered the mechanism of acquisition based on the epidemiologic association and positive catheter cultures for BCG in patients in whom mycobacterial cultures were performed.

Conclusions

Physicians should be alerted to the possibility of TB due to nosocomially acquired, catheter-related infections with M. bovis-BCG in patients with indwelling catheters. This problem may be more common than expected in centers providing BCG therapy for bladder cancer without adequate precautions.

Draft Genome Sequence of Mycolicibacterium sp. Strain NCC-Tsukiji, Isolated from Blood Culture of a Patient with Malignant Lymphoma

A nonidentifiable mycolicibacterium was isolated from a malignant lymphoma patient treated with intensive chemoimmunotherapy. Multilocus sequence analysis showed that this isolate was close to "Mycolicibacterium (Mycobacterium) ratisbonense," but the details of this species were still unknown. Here, we report the draft genome sequence data of Mycolicibacterium sp. strain NCC-Tsukiji.

Infections and outbreaks of nontuberculous mycobacteria in hospital settings

Purpose of review

Non-tuberculous mycobacterial [NTM] infections in the hospital setting are a complex and often challenging entity. The goal of this review is to discuss diagnostic and treatment strategies for established as well as emerging nosocomial NTM infections.

Recent findings

NTM outbreaks have been documented in a variety of hospital settings. Contamination of medical devices or aqueous solutions is often implicated in the spread of infection. More recently, the slow grower M. chimaera has been reported in the setting of contaminated heater-cooler devices used for cardiopulmonary bypass and extracorporeal membrane oxygenation. In addition, increases in medical tourism for cosmetic surgery have led to outbreaks of rapidly growing mycobacteria.

Summary

Diagnosis and treatment of nosocomial NTM pose many challenges for the clinician. Surgical resection or debridement as well as combination antimycobacterial therapy are a mainstay in therapeutic management. Strict infection control and prevention practices are critical to the identification and cessation of outbreaks.

Mycobacterium grossiae sp. nov., a rapidly growing, scotochromogenic species isolated from human clinical respiratory and blood culture specimens

A previously undescribed, rapidly growing, scotochromogenic species of the genus Mycobacterium (represented by strains PB739^T and GK) was isolated from two clinical sources - the sputum of a 76-year-old patient with severe chronic obstructive pulmonary disease, history of tuberculosis exposure and Mycobacterium avium complex isolated years prior; and the blood of a 15-year-old male with B-cell acute lymphoblastic leukaemia status post bone marrow transplant. The isolates grew as dark orange colonies at 25-37 °C after 5 days, sharing features in common with other closely related species. Analysis of the complete 16S rRNA gene sequence (1492 bp) of strain PB739^T demonstrated that the isolate shared 98.8 % relatedness with Mycobacterium wolinskyi. Partial 429 bp hsp65 and 744 bp rpoB region V sequence analyses revealed that the sequences of the novel isolate shared 94.8 and 92.1 % similarity with those of Mycobacterium neoaurum and Mycobacterium aurum, respectively. Biochemical profiling, antimicrobial susceptibility testing, HPLC/gas-liquid chromatography analyses and multilocus sequence typing support the taxonomic status of these isolates (PB739^T and GK) as representatives of a novel species. Both isolates were susceptible to the Clinical and Laboratory Standards Institute recommended antimicrobials for susceptibility testing of rapidly growing mycobacteria including amikacin, ciprofloxacin, moxifloxacin, doxycycline/minocycline, imipenem, linezolid, clarithromycin and trimethropin/sulfamethoxazole. Both isolates PB739^T and GK showed intermediate susceptibility to cefoxitin. We propose the name Mycobacterium grossiae sp. nov. for this novel species and have deposited the type strain in the DSMZ and CIP culture collections. The type strain is PB739^T (=DSM 104744^T=CIP 111318^T).

Mycobacterium Fortuitum Bloodstream Infection in a Very Low Birth Weight Preterm Neonate

Mycobacterium fortuitum is a rapidly growing Mycobacterium species that is a rare cause of disease, primarily in immunocompromised patients. We present a very low birth weight preterm neonate who developed M. fortuitum bloodstream infection, where 16S rDNA sequencing allowed accurate identification. Cure was achieved by line removal and adjuvant combination treatment with amikacin, ciprofloxacin and clarithromycin.

Nontuberculous Mycobacteria in Children: A Focus on Bloodstream Infections

BACKGROUND

Nontuberculous mycobacteria (NTM) are ubiquitous organisms with variable disease-causing potential. Bloodstream infections caused by NTM in children are poorly described.

METHODS

We describe a retrospective case series of children with culture-confirmed mycobacterial disease managed at the Children's Hospital at Westmead between July 2005 and June 2015.

RESULTS

Sixty-five patients had 149 positive NTM cultures; 55 (83.0%) episodes in 54 patients were considered clinically significant. Of the 54 children who met criteria for NTM disease, 25 (46.3%) had lymphadenitis, 13 (24.1%) lung disease, 8 (14.8%) had soft tissue infection or osteomyelitis and 8 (14.8%) had bacteremia. All children with bacteremia had a central venous catheter; those with pulmonary infection had underlying lung disease and all children with soft tissue infection or osteomyelitis had a history of recent penetrating injury. Disease caused by Mycobacterium avium-intracellulare complex was most common, accounting for 19 (76.0%) and 7 (53.8%) lymph node and lung infections, respectively. The most frequently isolated rapid growing mycobacteria were Mycobacterium fortuitum (8; 15%) and Mycobacterium abscessus (6; 11%), with M. fortuitum accounting for the majority (6; 75%) of bloodstream infections. Six (75%) patients with bacteremia had their intravenous catheter removed and all had a favorable outcome. A single disease relapse was reported in 1 of 2 patients with a retained catheter.

CONCLUSION

Lymphadenitis was the most common NTM disease manifestation and not associated with comorbidity. NTM bacteremia was always associated with a central line and catheter removal with cure. We were unable to assess the added value of various antibiotic regimens.

A cluster of central line-associated bloodstream infections due to rapidly growing nontuberculous mycobacteria in patients with hematologic disorders at a Japanese tertiary care center: an outbreak investigation and review of the literature

BACKGROUND Rapidly growing nontuberculous mycobacteria (RGM) are considered rare pathogens, causing central line-associated bloodstream infection. We identified an outbreak of central line-associated bloodstream infection due to RGM at a hematology-oncology ward during a 5-month period. DESIGN Outbreak investigation and literature review. SETTING A Japanese tertiary care center. PATIENTS Adults who were hospitalized at the hematology-oncology ward from October 15, 2011, through February 17, 2012. RESULTS A total of 5 patients with a bloodstream infection due to RGM (4 cases of Mycobacterium mucogenicum and 1 case of Mycobacterium canariasense infection) were identified; of these, 3 patients had acute myeloid leukemia, 1 had acute lymphocytic leukemia, and 1 had aplastic anemia. Four of the 5 patients received cord blood transplantation prior to developing the bloodstream infection. All central venous catheters in patients with a bloodstream infection were removed. These patients promptly defervesced after catheter removal and their care was successfully managed without antimicrobial therapy. Surveillance cultures from the environment and water detected M. mucogenicum and M. canariasense in the water supply of the hematology-oncology ward. The isolates from the bloodstream infection and water sources were identical on the basis of 16S-rRNA gene sequencing. CONCLUSIONS The source of RGM in the outbreak of bloodstream infections likely was the ward tap water supply. Awareness of catheter-related bloodstream infections due to nontuberculous mycobacteria should be emphasized, especially where immunocompromised patients are at risk. Also, using antimicrobials after catheter removal to treat central line-associated bloodstream infection due to RGM may not be necessary. Infect Control Hosp Epidemiol 2015;36(1): 76-80.

Human infections due to nontuberculous mycobacteria: the infectious diseases and clinical microbiology specialists' point of view

Nontuberculous mycobacteria (>150 species such as Mycobacterium avium, Mycobacterium kansasii, Mycobacterium chelonae and Mycobacterium abscessus) are opportunistic pathogens causing lung and extrarespiratory infections, beside M. ulcerans and M. marinum that are pathogens causing specific skin and soft tissue infections. Disseminated infections occur only in severe immunosuppressed conditions such as AIDS. The diagnosis is based on repeated isolations of the same mycobacterium associated with clinical and radiological signs, and the absence of tuberculosis. Precise species identification is obtained by molecular biology. Therapeutic antibiotic regimens differ with regard to the mycobacterial species that are involved. Prevention of iatrogenic infections relies on using sterile water in all injections, healthcare and cosmetic occupations. Future perspectives are to set effective antibiotic regimens tested in randomized therapeutic trials.

First report of Mycobacterium canariasense catheter-related bacteremia in the Americas

Mycobacterium canariasense is a recently described late-pigmenting, rapidly growing mycobacterium linked to bacteremia in patients with underlying malignant diseases. We report a case of M. canariasense infection in a patient from Massachusetts with underlying diffuse B cell lymphoma, which was identified both by multilocus sequence typing and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). To our knowledge, this is the first description after its original identification in Spain and the first report of this opportunistic pathogen in the Americas.

Sacroiliitis secondary to catheter-related bacteremia due to Mycobacterium abscessus (sensu stricto)

We describe a case of sacroiliitis secondary to catheter-related bacteremia due to Mycobacterium abscessus (sensu stricto). This case confirms that MultiLocus sequence typing and variable-number tandem-repeat methods are very robust techniques to identify the pathogen species and to validate molecular epidemiological links among complex M. abscessus isolates.

A case of Mycobacterium mucogenicum infection in a liver transplant recipient and a review of the literature

Bacterial, viral, and fungal infections can be devastating in a postoperative liver transplant recipient on multidrug immunosuppressive therapy. Various atypical (nontuberculous mycobacteria [NTM]) mycobacterial infections have been reported in the solid organ transplant population, but to our knowledge, no cases of Mycobacterium mucogenicum infections have been reported. Here, we report a case of a patient with end-stage liver disease secondary to primary biliary cirrhosis, model for end-stage liver disease score of 29, who underwent deceased-donor orthotopic liver transplantation, with her postoperative course complicated by multiple pleural effusions and peritonitis. Despite numerous courses of antibiotics, her condition did not improve. Acid-fast bacilli cultures grew M. mucogenicum, which was then treated with appropriate antimicrobical therapy. M. mucogenicum, a rapidly growing NTM that can be present in water contamination, should be recognized as a potential source of infection, especially in the immunocompromised population.

A case of catheter-related bloodstream infection caused by Mycobacterium phocaicum

We present a patient with double hit Burkitt's like lymphoma who developed a catheter-related bloodstream infection due to Mycobacterium phocaicum that was identified by rpoB gene sequencing. His infection resolved with 7 weeks of antibiotics and port-a-cath removal.

Management of rapidly growing mycobacterial bacteremia in cancer patients

Rapidly growing mycobacteria (RGM) are environmental organisms capable of causing a wide spectrum of diseases. We identified 116 cancer patients with RGM. Mycobacterium mucogenicum was the leading cause of disease. Removal of the catheter correlated with significant decrease in the bacteremia relapse rate (P = .007). A median duration of 4 weeks of therapy produced a good outcome.

Disseminated Mycobacterium gordonae infection in a child with cystic fibrosis

A 4-year-old girl with cystic fibrosis (CF) presented with unrelenting pyrexia commencing shortly after flushing of the central venous catheter (CVC). Mycobacterium gordonae was subsequently isolated from bronchoalveolar lavage, gastric washings, and lung biopsy. While this case most likely represents central line infection by a non-tuberculous mycobacterial (NTM) species, it is difficult to state this definitively in the absence of positive cultures from the CVC. We suggest that infection with NTM should always be considered in CF patients with indwelling devices and unexplained fever.

An outbreak of Mycobacterium mucogenicum bacteremia in pediatric hematology-oncology patients

BACKGROUND AND AIMS

Mycobacterium mucogenicum (MM) is a rapidly growing nontuberculous mycobacterium that is commonly identified in tap water that can rarely cause bacteremia. We describe an outbreak of MM bacteremia among pediatric hematology-oncology patients.

METHODS

Charts of children with MM bacteremia were retrospectively reviewed. Demographic data, underlying conditions, central venous catheter (CVC) type, duration of bacteremia, and treatment were retrieved. Epidemiologic investigation was conducted during the outbreak including environmental sampling.

RESULTS

During an 8-month period (September 2005-May 2006), 8 patients aged 1.5 to 17 years had MM bacteremia. Seven patients had underlying malignancy and 1 with thalassemia major had bone marrow transplantation. The mean number of positive blood cultures was 4.2 (1-11) per patient. Two patients received antibiotic treatment in addition to removal of CVC. All patients were cured. Almost 60 environmental samples were obtained from surfaces, ice, and municipal water supply. All were negative and no source was documented. Infection control measures included emphasis on guidelines for prevention of CVC-associated infections. No cases occurred before and after this outbreak.

CONCLUSIONS

MM is a rare agent of CVC-associated bacteremia. Removal of the CVC may be sufficient for management of bacteremia. In the absence of definite source identification, reinforcement of standard infection control measures can be successful in containing outbreaks.

Catheter-related bloodstream infections: catheter management according to pathogen

Central-line access is an essential part of modern healthcare practice; however, catheter-related bloodstream infection is a major problem that causes substantial morbidity and mortality, and excess length of stay and cost. The risk of infection depends on the type of device, the site of insertion, the underlying conditions and the appropriate prevention measures taken during catheter insertion. Management of catheter-related bloodstream infection involves deciding on catheter removal, antimicrobial catheter lock solution and the type and duration of systemic antimicrobial therapy. Systemic antimicrobial use is essential but, although generally effective in controlling sepsis, it often fails to sterilise the line, increasing the incidence of complications or recurrence. The decision regarding whether the catheter should be removed or retained is therefore crucial. One of the major factors to be considered is the type of organism involved in the catheter-related infection. This review outlines the epidemiology, pathogenesis, diagnosis, microbiology and management of catheter-related infections, mainly focusing on the management of the intravascular device according to the pathogen.

Infections in the immunocompromised

Infections in the immunocompromised differ significantly from those in the immunocompetent. They can be more serious, more often life threatening, more difficult to diagnose and are caused by more unusual organisms. Children can be immunocompromised for a variety of reasons and the numbers, worldwide, are growing.

Mycobacterium mucogenicum group infections: a review

It has become apparent that Mycobacterium mucogenicum isolates recovered from clinical samples are more diverse than was previously realized and include an increasing number of emerging pathogens, as depicted by multilocus sequence analysis. Most clinically significant cases of those organisms involved catheter-related infections. They are susceptible to most antimicrobial agents, but like other rapidly growing mycobacteria, they are resistant to first-line antituberculous agents. A review of the cases of M. mucogenicum complex infection in the literature is addressed here, as well as two additional cases of the closely related species Mycobacterium aubagnense.