Successful treatment of disseminated nocardiosis diagnosed by metagenomic next-generation sequencing: A case report and review of literature

Persistent Nocardia beijingensis infection in a patient with postoperative abscess and misuse of antibiotics in China

Here we describe the first case of abscess infection caused by Nocardia beijingensis in China. The patient was immunocompetent but suffered from postoperative abscess for 6 years. This study highlights the necessity of long-term infected foci to be thoroughly examined to identify the pathogen, as well as the importance of accurate Nocardia identification and antimicrobial susceptibility tests for understanding the pathogen's epidemiology, clinical significance, and treatment strategy.

Multiple brain abscesses caused by Nocardia asiatica: Case report and literature review

Nocardia are opportunistic pathogens mainly affecting immunocompromised individuals. Nocardia asiatica, a novel species, can cause severe infections. We present a case of multiple brain abscesses due to Nocardia asiatica, discussing its diagnosis and treatment. In January 2022, a 27-year-old Chinese woman with a history of atypical membranous nephropathy presented with low-grade fever, cough, limb weakness, and headaches. Imaging revealed lung and brain lesions. Neurological symptoms worsened over time, culminating in recurrent seizures and severe headaches. A brain MRI confirmed multiple abscesses. Craniotomy and lesion removal were performed, leading to a diagnosis of brain abscesses caused by Nocardia asiatica. Empirical antibiotics were followed by targeted regimen. After successful treatment, the patient remained symptom-free during follow-ups. Nocardia asiatica multiple brain abscesses are exceedingly rare. This case underscores the importance of considering nocardiosis in immunosuppressed patients presenting with neurological symptoms. Timely neurosurgical intervention and effective antibiotic therapy are crucial. Metagenomic next-generation sequencing proved invaluable for rapid diagnosis. Treatment with trimethoprim-sulfamethoxazole (TMP-SMX) and a carbapenem followed by TMP-SMX alone achieved disease control. This case contributes to the understanding of Nocardia asiatica infections and highlights the role of neurosurgical procedures in managing disseminated nocardiosis.

Respiratory metagenomics: route to routine service

PURPOSE OF REVIEW

The coronavirus disease 2019 pandemic demonstrated broad utility of pathogen sequencing with rapid methodological progress alongside global distribution of sequencing infrastructure. This review considers implications for now moving clinical metagenomics into routine service, with respiratory metagenomics as the exemplar use-case.

RECENT FINDINGS

Respiratory metagenomic workflows have completed proof-of-concept, providing organism identification and many genotypic antimicrobial resistance determinants from clinical samples in <6 h. This enables rapid escalation or de-escalation of empiric therapy for patient benefit and reducing selection of antimicrobial resistance, with genomic-typing available in the same time-frame. Attention is now focussed on demonstrating clinical, health-economic, accreditation, and regulatory requirements. More fundamentally, pathogen sequencing challenges the traditional culture-orientated time frame of microbiology laboratories, which through automation and centralisation risks becoming increasingly separated from the clinical setting. It presents an alternative future where infection experts are brought together around a single genetic output in an acute timeframe, aligning the microbiology target operating model with the wider human genomic and digital strategy.

SUMMARY

Pathogen sequencing is a transformational proposition for microbiology laboratories and their infectious diseases, infection control, and public health partners. Healthcare systems that link output from routine clinical metagenomic sequencing, with pandemic and antimicrobial resistance surveillance, will create valuable tools for protecting their population against future infectious diseases threats.