Oring, Justin

Background: Mycobacterium nebraskense is a rare, slow growing nontuberculous mycobacterium species with limited documented cases. This systematic review aims to comprehensively analyze the clinical characteristics, presentation, and management of M. nebraskense infections by analyzing the available literature, including a newly reported case that we present in this article. Methods: A comprehensive search was conducted using PubMed and Google Scholar to identify relevant cases up to October 2023. Only seven reported cases were found, highlighting the scarcity of information on this pathogen. Results: Our analysis revealed several key findings. First, gender disparities were observed, with females being more susceptible to M. nebraskense infections. Additionally, a significant portion of patients presented with asymptomatic infections. Most affected individuals were over the age of 60, emphasizing potential age-related susceptibility. Comorbidity profiles varied widely among cases, and patients with preexisting lung comorbidities were at an increased risk of infection. The decision to treat or observe depended on clinical presentation, with even immunosuppressed individuals not always requiring treatment. Regarding treatment, we proposed an empirical approach with amikacin, clarithromycin, or rifabutin, considering the reported resistance to doxycycline and minocycline. Combination therapy was commonly employed to minimize resistance development, consistent with mycobacterial infection management. Conclusion: This study underscores the need for further research to validate these findings and enhance our understanding of M. nebraskense infections. As limited data are available, this review aims to provide valuable insights into a rare and emerging pathogen to guide clinical practice and future research endeavors.

Abstract We present the case of a 61-year-old woman with a history of orthotopic heart transplant who was hospitalized with new-onset headache. Magnetic resonance imaging (MRI) of the brain revealed T2 hyperintense signal involving the left occipital lobe with leptomeningeal enhancement and mild vasogenic edema. Initial neurologic examination was normal; however, after 7 days she developed imbalance, visual disturbances, night sweats, bradyphrenia, alexia without agraphia, and right hemianopsia. Brain MRI showed enlargement of the left occipital mass and worsening edema. Stereotactic needle biopsy showed nondiagnostic necrosis. The patient continued to deteriorate despite dexamethasone. Cerebrospinal fluid (CSF) suggested infection, and cytomegalovirus CSF polymerase chain reaction (PCR) was positive. The patient received vancomycin, imipenem, and ganciclovir. After obtaining a positive serum beta-D-glucan (Fungitell), amphotericin was added. Despite best medical efforts, the patient died. Postmortem broad-range PCR sequencing of the brain tissue was positive for rare amoeba Balamuthia mandrillaris.

Abstract Background Echinococcus multilocularis is a destructive zoonotic cestode with low human incidence. Hydatid disease classically presents with hepatic or lung involvement with infrequent extrahepatic bone destruction. Diagnosis is challenging due to its latency and mimicry. Fig.1: Case 1 - X-ray imaging of the pelvis shows osseous destruction of the iliac crest secondary to known osteomyelitis status post left ilium debridement. Fig.2: Case 1 - Magnetic resonance imaging demonstrates extensive osteomyelitis throughout left ilium. Stable scattered focal fluid collections seen throughout the left lower quadrant. Methods CASE 1: A 57 year-old Albanian male with diabetes, latent TB, and left iliac lytic lesion presented with 4 weeks of left flank pain and was treated with 6 weeks of IV Ceftriaxone and Flagyl. 2 years later he returned with flank pain and purulent lumbar drainage. Hip x-ray suggested chronic osteomyelitis, with left psoas fluid collections on CT. Bartonella, Q fever, Brucella, HIV, AFB and fungal serologies were negative. Hemipelvis debridement revealed structures concerning for hydatid disease. Echinococcus IgG was equivocal. Histopathology was consistent with Echinococcus multilocularis species, and albendazole was started. On follow-up, he presented with left hip tenderness and toe extensor weakness. Labs showed mild leukocytosis. CT revealed progressive destruction of the left iliac with sacroiliac extension concerning for abscess. CASE 2: A 36 year-old female presented with lung and liver cysts, progressive dyspnea, and non-productive cough. She lived in Africa, Asia, and Europe and consumed local street food and unpasteurized milk. Hobbies included spelunking and swimming in freshwater lakes. She had exposure to stray animals, but denied bites or scratches. Over 4 years dyspnea progressed to orthopnea. MR abdomen revealed a 10x6x12cm liver cyst and chest CT showed 2 fluid-attenuating lesions in the LLL and RLL, measuring 4.9 x 6.0 cm and 6.8 x 4.3 cm respectively. Echinococcus, Bartonella, Q fever, Brucella, HIV, AFB and fungal serologies were negative. Schistosomiasis serology was equivocal. Fig. 3: Case 2 - MRI abdomen demonstrating 10x6x12cm liver cyst Fig. 4: Case 2 - Chest CT showed 2 dominant fluid attenuating lesions within the LLL and RLL. The larger lesion in RLL measures 6.8 x 4.3 cm. The left lower lobe lesion measures 4.9 x 6.0 cm. Results Patient 1 underwent type I hemipelvectomy. Patient 2 underwent pulmonary segmentectomy and liver lobectomy. Both were continued on albendazole. Fig. 5: Case 1 - Photo taken during debridement of left ileac and hip. Note presence of white cysts discovered intraoperatively. Fig. 6: Case 1 - Histopathologic slides (H&E stain) demonstrating hooks and scolices consistent with Echinococcus multilocularis. A. Hooklet (100x magnification). B. Hydatid cyst with black-staining structures suggestive of degenerating hooklets. C. Zoomed detail of cyst wall. D. Degenerating hydatid cyst and hooklets. Conclusion Equivocal IgG serology does not exclude infection. History and clinical presentation are key to diagnosis, but histopathology remains the gold standard. Hydatid bone infection progresses insidiously and frequently recurs, depending upon excision and debridement. Finally, echinococcosis demands aggressive long-term therapy and surveillance. Disclosures Claudia R. Libertin, MD, Pfizer, Inc. (Grant/Research Support, Research Grant or Support)