Management of nontuberculous mycobacterial infections of the eye and orbit: A retrospective case series

Nontuberculous mycobacterial abscess of lacrimal sac and eyelid debridement: Case report

Key Clinical Message

It is important to stain acid-fact bacilli on the smear of abscess puncture in addition to Gram stain to detect nontuberculous and tuberculous mycobacteria in the early phase since both can cause rare and challenging extrapulmonary manifestations.

Abstract

A 56-year-old otherwise healthy woman developed abscess from dacryocystitis in the right lower eyelid. The smear of puncture fluid showed acid-fast bacilli and Mycobacterium abscessus was identified after a month. The early start of clarithromycin/ethambutol was switched to clarithromycin/levofloxacin. Debridement specimen after 7-month treatment showed granulomatous tissue with no bacilli.

Omadacycline for management of Mycobacterium abscessus infections: a review of its effectiveness, place in therapy, and considerations for use

The Mycobacterium abscessus complex (MABC) is a group of acid-fast, rapidly dividing non-tuberculous mycobacteria (NTM) that include a number of clinically important subspecies, including M. abscessus, M. bolletii, and M. massiliense. These organisms are prevalent in the environment and are primarily associated with human pulmonary or skin and skin structure infections (SSSI) but may cause more deep-seeded disseminated infections and bacteremia in the immunocompromised. Importantly, these NTM are resistant to most first-line anti-tuberculous agents and, due to intrinsic or acquired resistance, exhibit exceedingly low, variable, and geographically distinct susceptibilities to commonly used antibacterial agents including older tetracyclines, macrolides, aminoglycosides, cephalosporins, carbapenems, and sulfamethoxazole-trimethoprim. Omadacycline is a novel third-generation member of the tetracycline family of antibacterials that has recently been demonstrated to have potent anti-NTM effects and clinical efficacy against MABC, including M. abscessus. The purpose of this review is to present a comprehensive and up-to-date assessment on the body of literature on the role of omadacycline for M. abscessus infections. Specifically, the in vitro and in vivo microbiology, mechanisms of action, mechanisms of resistance, clinical pharmacokinetics, clinical efficacy, adverse effects, dosage and administration, and place in therapy of omadacycline in management of M. abscessus infections will be detailed.

Periocular Infection of Mycobacterium avium Complex in a Patient with Interferon-γ Autoantibodies: A Case Report

The neutralizing anti-interferon-γ autoantibody (nAIGA)-associated immunodeficiency is an emerging entity frequently associated with the nontuberculosis mycobacterium (NTM) infection and other opportunistic infections. We present a female patient with a mysterious periocular Mycobacterium avium complex (MAC) infection, accompanied by sequential opportunistic infections including Salmollelosis and herpes zoster infection. Her condition stabilized after long-term antimycobacterial treatment. Nevertheless, neutralizing anti-interferon-γ autoantibody was found in her serum, which was compatible with the scenario of adult-onset immunodeficiency.

Comparative survival of environmental and clinical Mycobacterium abscessus isolates in a variety of diverse host cells

Aims

Mycobacterium abscessus subsp. abscessus (MABS) is an emerging, opportunistic pathogen found globally in freshwater biofilms and soil. Typically, isolates are treated as a uniform group of organisms and very little is known about their comparative survival in healthy host cells. We posit that environmentally‐ and clinically derived isolates, show differential infectivity in immune cells and resistance to innate defenses.

Methods and Results

Six MABS isolates were tested including three water biofilm/soil and three sputum‐derived isolates. A clinical MABS type strain and an environmental isolate of Arthrobacter were also included. MABS counts were significantly higher compared to Arthrobacter after co‐culture with Acanthamoeba lenticulata, BEAS‐2B epithelial cells, alveolar macrophages and the THP‐1 macrophage cell line. A rough sputum‐derived MABS isolate emerged as an isolate with higher virulence compared to others tested, as both a pellicle and cord former, survivor in the human cell models tested, inducer of high and prolonged production of pro‐inflammatory cytokines, and the capacity to evade LL‐37.

Conclusions

Findings support intraspecies variation between MABS isolates.

Significance and Impact of the Study

These data indicate subversion of host immune defenses by environmental and clinical MABS isolates is nuanced and maybe isolate dependent, providing new information regarding the pathogenesis of NTM infections.

Scleral Buckle Infection Caused by Mycobacterium chelonae: A Case Report

A 63-year-old female with a history of retinal detachment repair with scleral buckle from 28 years prior presented with exposure of the buckle in her right eye. After removing the buckle and anchoring sutures, the operation field was washed with 0.25% polyvinyl alcohol-iodine, vancomycin, and ceftazidime. Cultures revealed Mycobacterium chelonae. Systemic meropenem was discontinued on postoperative day 5. The retina remained attached, and there was no recurrence over a 1-year follow-up. We report a case of NTM buckle infection that responded well to thorough washings with polyvinyl alcohol-iodine and antibiotic solutions instead of using a prolonged course of systemic antibiotics.