Mediastinitis due to Mycobacterium fortuitum infection following Fontan operation in a child

Nontuberculous Mycobacteria in Saudi Arabia and Gulf Countries: A Review

Nontuberculous Mycobacteria (NTM) are causing growing health problems worldwide. This is indicated by an increasing amount of scientific reports showing not only well-identified species reemerging but also emergence of new species. The emergence and reemergence of NTM are particularly worrying in developing countries due to scarce published data and improper identification. Here we aimed to examine the main epidemiological aspects and diagnostic challenges associated with NTM in countries of the Gulf Cooperation Council (GCC) and compare these findings to the international arena findings. Data revealed that countries of the GCC are largely dominated by rapidly growing mycobacteria species such as M. fortuitum (29%) and M. abscessus (17%) with high rate of definitive respiratory diseases. On the other hand, most of the developed countries are dominated by slowly growing mycobacteria such as MAC, M. kansasii, and M. gordonae. More efforts are needed, however, to gain insights into NTM issues in countries of the GCC.

Nontuberculous mycobacteria in Middle East: Current situation and future challenges

Nontuberculous mycobacteria (NTM) are a diverse group of bacterial species that are distributed in the environment. Many of these environmental bacteria can cause disease in humans. The identification of NTM in environmental sources is important for both clinical and epidemiological purposes. In this study, the distribution of NTM species from environmental and clinical samples in the Middle East was reviewed. In order to provide an overview of NTM, as well as recent epidemiological trends, all studies addressing NTM in the Middle East from 1984 to 2014 were reviewed. A total of 96 articles were found, in which 1751 NTM strains were isolated and 1084 of which were obtained from clinical samples, 619 from environmental samples and 48 were cited by case reports. Mycobacterium fortuitum was the most common rapid growing mycobacteria (RGM) isolated from both clinical (269 out of 447 RGM; 60.1%) and environmental (135 out of 289 RGM; 46.7%) samples. Mycobacterium avium complex (MAC) was the most common slow growing mycobacteria (SGM) isolated from clinical samples (140 out of 637 SGM; 21.9%). An increasing trend in NTM isolation from the Middle East was noted over the last 5years. This review demonstrates the increasing concern regarding NTM disease in the Middle East, emphasizing the need for regional collaboration and coordination in order to respond appropriately.

Sternal wound infection caused by Mycobacterium chelonae

INTRODUCTION

Sternal wound infection caused by Mycobacterium chelonae, a member of the rapidly growing nontuberculous mycobacteria (NTM), is rare and may present without signs and symptoms of systemic infection.

METHODS

We present a patient who had a M. chelonae infection of the sternum following excision of a left atrial myxoma and conducted a review of the literature from 1976 to 2013.

RESULTS

Seventy cases of NTM sternal wound infection after cardiac surgery were identified, including six outbreaks and ten sporadic cases including the present case. Thirty-four cases were isolated coronary artery bypass grafting (CABG) surgery, 16 cases were isolated valve replacement, and two cases were valve replacement with CABG. The age range of the patients was between 6 and 78 years. The average time from the surgery was 49 ± 58 days which was longer than the usual bacterial mediastinitis. The overall mortality rate was 29%.

CONCLUSION

NTM sternal wound infection is rare but may be fatal if not properly treated. The toxic signs are often subtle and it will take longer to isolate compared to typical bacterial mediastinitis. Early recognition, the use of appropriate antibiotics based on susceptibility tests, and aggressive surgical debridement are required for full recovery.

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

BACKGROUND

Mycobacterium goodii is a rare cause of significant infection. M. goodii has mainly been associated with lymphadenitis, cellulitis, osteomyelitis, and wound infection.

CASE PRESENTATION

A case of a 76-year-old Caucasian female is presented. The patient developed a prosthetic valve endocarditis caused by M. goodii. She had also suffered from severe neurological symptoms related to a septic emboli that could be demonstrated as an ischemic lesion found on CT of the brain. Transesophageal echocardiography verified a large vegetation attached to the prosthetic valve. Commonly used blood culture bottles showed growth of the bacteria after 3 days.

CONCLUSIONS

Although M. goodii is rarely involved in these kinds of severe infections, rapidly growing mycobacteria should be recognized during conventional bacterial investigations and identified by molecular tools such as analysis of 16S rDNA. Species identification of nontuberculous mycobacteria is demanding and is preferably done in collaboration with a mycobacterial laboratory. An early diagnosis provides the opportunity for adequate treatment. In the present case, prolonged antimicrobial treatment and surgery with replacement of the prosthetic valve was successful.

Pacemaker infection due to Mycobacterium fortuitum: the role of universal 16S rRNA gene PCR and sequencing

Rapidly growing mycobacteria are a rare cause of pacemaker infection. A low index of suspicion and conventional diagnostic methods may delay diagnosis. We present a review of the literature and report a case of pacemaker infection due to Mycobacterium fortuitum rapidly detected by universal 16S rRNA gene polymerase chain reaction and sequencing.

Culture-Negative Surgical Site Infections

BACKGROUND

The appearance of postoperative surgical site infection (SSI) in the absence of culturable bacterial pathogens is a common dilemma for the surgeon.

METHODS

The literature was searched through references to primary articles, as well as a MEDLINE review, for reports of culture-negative SSIs.

RESULTS

Potential causes of culture-negative SSIs include prior antimicrobial therapy; the presence of fastidious or slow-growing microorganisms such as mycobacteria, Mycoplasma spp., and Legionella spp.; infection caused by mundane bacteria that may be dismissed as "contaminants"; factitious infection; and others.

CONCLUSIONS

We review the recognized causes of "culture negative" SSIs and discuss the laboratory capabilities that may enhance recognition of many of these pathogens and management options.

Nosocomial infections due to nontuberculous mycobacteria

Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and cause colonization, infection, and pseudo-outbreaks in health care settings. Data suggest that the frequency of nosocomial outbreaks due to NTM may be increasing, and reduced hot water temperatures may be partly responsible for this phenomenon. Attention to adequate high-level disinfection of medical devices and the use of sterile reagents and biologicals will prevent most outbreaks. Because NTM cannot be eliminated from the hospital environment, and because they present an ongoing potential for infection, NTM should be considered in all cases of nosocomial infection, and careful surveillance must be used to identify potential outbreaks. Analysis of the species of NTM and the specimen source may assist in determining the significance of a cluster of isolates. Once an outbreak or pseudo-outbreak is suspected, molecular techniques should be applied promptly to determine the source and identify appropriate control measures.