A case of Mycobacterium goodii prosthetic valve endocarditis in a non-immunocompromised patient: use of 16S rDNA analysis for rapid diagnosis

Four decades of experience of prosthetic valve endocarditis reflect a high variety of diverse pathogens

Prosthetic valve endocarditis (PVE) remains a serious condition with a high mortality rate. Precise identification of the PVE-associated pathogen/s and their virulence is essential for successful therapy, and patient survival. The commonly described PVE-associated pathogens are staphylococci, streptococci and enterococci, with Staphylococcus aureus being the most frequently diagnosed species. Furthermore, multi-drug resistance pathogens are increasing in prevalence, and continue to pose new challenges mandating a personalized approach. Blood cultures in combination with echocardiography are the most common methods to diagnose PVE, often being the only indication, it exists. In many cases, the diagnostic strategy recommended in the clinical guidelines does not identify the precise microbial agent and to frequently, false negative blood cultures are reported. Despite the fact that blood culture findings are not always a good indicator of the actual PVE agent in the valve tissue, only a minority of re-operated prostheses are subjected to microbiological diagnostic evaluation. In this review, we focus on the diversity and the complete spectrum of PVE-associated bacterial, fungal and viral pathogens in blood, and prosthetic heart valve, their possible virulence potential, and their challenges in making a microbial diagnosis. We are curious to understand if the unacceptable high mortality of PVE is associated with the high number of negative microbial findings in connection with a possible PVE. Herein, we discuss the possibilities and limits of the diagnostic methods conventionally used and make recommendations for enhanced pathogen identification. We also show possible virulence factors of the most common PVE-associated pathogens and their clinical effects. Based on blood culture, molecular biological diagnostics, and specific valve examination, better derivations for the antibiotic therapy as well as possible preventive intervention can be established in the future.

A case of Mycobacterium goodii infection related to an indwelling catheter placed for the treatment of chronic symptoms attributed to Lyme disease

Mycobacterium goodii has only rarely been reported to cause invasive disease in humans. Previously reported cases of M. goodii infection have included prosthetic joint infections, pacemaker pocket infections, and pneumonia. We present a case of M. goodii bacteremia with concomitant pulmonary septic emboli that developed in a 32-year-old woman with an indwelling central venous catheter (CVC). The CVC had been placed one year previously for intermittent treatment with intravenous, broadspectrum antibiotics, administered by an outside physician for the treatment of symptoms attributed to chronic Lyme disease. Despite our recommendations, the patient declined follow-up in our Infectious Diseases clinic, opting to continue care under her chronic Lyme disease physician. This case clearly demonstrates the potential for serious medical complications that can arise from the inappropriate use of longterm intravenous antibiotics using a CVC to treat non-specific symptoms attributed to Lyme disease and patients should be counseled regarding these risks.

Prosthetic Conduit Endocarditis With Nontuberculous Mycobacteria in a Child: Associated With the Water Mattress and Heater Chiller Unit

There is a growing body of literature on infection with nontuberculous mycobacteria (NTM) associated with heater chiller units in the cardiac surgery population. We report a pediatric case undergoing reoperation for early right ventricle-to-pulmonary artery conduit stenosis. A successful outcome was achieved following excision of the infected conduit and six-week antibiotic treatment. To our knowledge, there is only one other pediatric cardiac case reported in the literature. Similar to the recently reported cases of infection associated with Mycobacterium chimaera in predominately adult patients after cardiac bypass surgery, we hypothesize that water-containing devices such as the heater chiller unit and water blanket acted as a reservoir for other NTM. With increasing awareness of NTM, we analyzed the 2015-2016 culture data on our fleet of eight heater chiller units. We identified an association between persistent positive cultures and the connection of a water mattress to the heater chiller unit circuit. This led us to abandoning the use of the mattress in pediatric cardiac surgery.

Mycobacterium goodii endocarditis following mitral valve ring annuloplasty

BACKGROUND

Mycobacterium goodii is an infrequent human pathogen which has been implicated in prosthesis related infections and penetrating injuries. It is often initially misidentified as a gram-positive rod by clinical microbiologic laboratories and should be considered in the differential diagnosis.

CASE PRESENTATION

We describe here the second reported case of M. goodii endocarditis. Species level identification was performed by 16S rDNA (ribosomal deoxyribonucleic acid) gene sequencing. The patient was successfully treated with mitral valve replacement and a prolonged combination of ciprofloxacin and trimethoprim/sulfamethoxazole.

CONCLUSION

Confirmation of the diagnosis utilizing molecular techniques and drug susceptibility testing allowed for successful treatment of this prosthetic infection.

Pacemaker pocket infection due to Mycobacterium goodii, a rapidly growing mycobacteria

A woman aged 74 years with an implanted dual-chamber pacemaker presented with pacemaker site infection after failing empiric antimicrobial therapy. The pathogen was later identified as Mycobacterium goodii, a rapidly growing mycobacteria species. The pacemaker was subsequently removed and the patient was treated with oral ciprofloxacin and doxycycline with clinical improvement. In this article, we describe a rare case of pacemaker site infection by M. goodii.

Mycobacterium goodii: An Emerging Nosocomial Pathogen: A Case Report and Review of the Literature

The authors present a successfully treated case of Mycobacterium goodii cardiac device pocket infection, complicated by inherent resistance and drug reactions. This case highlights the complexity of treating these infections. This article outlines treatment approaches and caveats, including duration of therapy and when device reimplantation is appropriate.

Mycobacterium goodii, a rapidly growing nontuberculous mycobacterium, is an emerging pathogen in nosocomial infections. Its inherent resistance patterns make it a challenging organism to treat, and delays in identification can lead to poor outcomes. We present a case of cardiac device pocket infection with M. goodii, complicated by both antibiotic resistance and drug reactions that highlight the challenges faced by clinicians trying to eradicate these infections. We also present a brief review of the English literature surrounding this disease, including a table of all reported cases of M. goodii infections and their outcomes to act as guide for clinicians formulating treatment plans for these infections. A clear understanding of diagnostic methods and treatment caveats is essential to curing infections caused by these organisms.

Mycobacterial endocarditis: a comprehensive review

OBJECTIVE

A systematic analysis was made in view of the epidemiology, clinical features, diagnosis, treatment and main outcomes of mycobacterial endocarditis.

METHODS

The data source of the present study was based on a comprehensive literature search in MEDLINE, Highwire Press and Google search engine for publications on mycobacterial endocarditis published between 2000 and 2013.

RESULTS

The rapidly growing mycobacteria become the predominant pathogens with Mycobacterium chelonae being the most common. This condition has changed significantly in terms of epidemiology since the 21st century, with more broad patient age range, longer latency, prevailed mitral valve infections and better prognosis.

CONCLUSION

Mycobacterial endocarditis is rare and the causative pathogens are predominantly the rapidly growing mycobacteria. Amikacin, ciprofloxacin and clarithromycin are the most frequently used targeted antimicrobial agents but often show poor responses. Patients with deep infections may warrant a surgical operation or line withdrawal. With periodic multidrug therapy guided by drug susceptibility testing, and surgical managements, patients may achieve good therapeutic results.

Healthcare-associated prosthetic heart valve, aortic vascular graft, and disseminated Mycobacterium chimaera infections subsequent to open heart surgery

AIMS

We identified 10 patients with disseminated Mycobacterium chimaera infections subsequent to open-heart surgery at three European Hospitals. Infections originated from the heater-cooler unit of the heart-lung machine. Here we describe clinical aspects and treatment course of this novel clinical entity.

METHODS AND RESULTS

Interdisciplinary care and follow-up of all patients was documented by the study team. Patients' characteristics, clinical manifestations, microbiological findings, and therapeutic measures including surgical reinterventions were reviewed and treatment outcomes are described. The 10 patients comprise a 1-year-old child and nine adults with a median age of 61 years (range 36-76 years). The median duration from cardiac surgery to diagnosis was 21 (range 5-40) months. All patients had prosthetic material-associated infections with either prosthetic valve endocarditis, aortic graft infection, myocarditis, or infection of the prosthetic material following banding of the pulmonary artery. Extracardiac manifestations preceded cardiovascular disease in some cases. Despite targeted antimicrobial therapy, M. chimaera infection required cardiosurgical reinterventions in eight patients. Six out of 10 patients experienced breakthrough infections, of which four were fatal. Three patients are in a post-treatment monitoring period.

CONCLUSION

Healthcare-associated infections due to M. chimaera occurred in patients subsequent to cardiac surgery with extracorporeal circulation and implantation of prosthetic material. Infections became clinically apparent after a time lag of months to years. Mycobacterium chimaera infections are easily missed by routine bacterial diagnostics and outcome is poor despite long-term antimycobacterial therapy, probably because biofilm formation hinders eradication of pathogens.

Brown-Pigmented Mycobacterium mageritense as a Cause of Prosthetic Valve Endocarditis and Bloodstream Infection

Mycobacterium spp. are a rare cause of endocarditis. Herein, we describe a case of Mycobacterium mageritense prosthetic valve endocarditis. This organism produced an unusual brown pigment on solid media. Cultures of valve tissue for acid-fast bacilli might be considered in some cases of apparently culture-negative prosthetic valve endocarditis.

Nontuberculous Mycobacteria: An Underestimated Cause of Bioprosthetic Valve Infective Endocarditis

From 2010 to 2013, 5 cases of nontuberculous mycobacteria infective endocarditis (IE), exclusively from bioprosthesis, were diagnosed in three hospitals out of 370 blood culture-negative-suspected IE. The porcine origin of this underestimated etiology is questioned.

Background. Atypical mycobacteria, or nontuberculous mycobacteria (NTM), have been barely reported as infective endocarditis (IE) agents.

Methods. From January 2010 to December 2013, cardiac valve samples sent to our laboratory as cases of blood culture-negative suspected IE were analyzed by 16S rDNA polymerase chain reaction (PCR). When positive for NTM, hsp PCR allowed species identification. Demographic, clinical, echocardiographic, histopathological, and Ziehl-Neelsen staining data were then collected.

Results. Over the study period, 6 of 370 cardiac valves (belonging to 5 patients in 3 hospitals) were positive for Mycobacterium chelonae (n = 5) and Mycobacterium lentiflavum (n = 1) exclusively on bioprosthetic material. The 5 patients presented to the hospital for heart failure without fever 7.1–18.9 months (median 13.1 months) after biological prosthetic valve implantation. Echocardiography revealed paravalvular regurgitation due to prosthesis dehiscence in all patients. Histopathological examination of the explanted material revealed inflammatory infiltrates in all specimens, 3 of which were associated with giant cells. Gram staining and conventional cultures remained negative, whereas Ziehl-Neelsen staining showed acid-fast bacilli in all patients. Allergic etiology was ruled out by antiporcine immunoglobulin E dosages. These 5 cases occurred exclusively on porcine bioprosthetic material, revealing a statistically significant association between bioprosthetic valves and NTM IE (P < .001).

Conclusions. The body of evidence confirmed the diagnosis of prosthetic IE. The statistically significant association between bioprosthetic valves and NTM IE encourages systematic Ziehl-Neelsen staining of explanted bioprosthetic valves in case of early bioprosthesis dysfunction, even without an obvious sign of IE. In addition, we strongly question the cardiac bioprosthesis conditioning process after animal sacrifice.