Disseminated infection caused by Nocardia cyriacigeorgica in immunocompromised patient confirmed by whole genome sequencing.

INTRODUCTION: Nocardia spp. is an opportunistic pathogen capable of causing localized and disseminated infections in immunocompromised hosts. It is critical for serious infections to have an early and accurate identification of this pathogen in order to enable timely and focused combination antimicrobial treatment. CASE PRESENTATION: We describe the case of 87-year old patient previously treated for myasthenia gravis with corticosteroids and azathioprine. Patient was admitted at the emergency department with a clinical signs of sepsis with cellulitis of right hand associated with injury acquired after gardening and trimming of roses and did not respond to empirical antimicrobial treatment. Computerized tomography revealed pulmonary infiltrates with inflammatory aetiology. Nocardia cyriacigeorgica was cultivated from blood culture, skin swab, abscess aspirate and endotracheal aspirate and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), 16S rRNA sequencing and whole genome sequencing (WGS). Susceptibility testing was performed with E-test (bioMerieux, Marcy-l'Étoile, France) and corresponding resistance genes were detected by WGS. Resistance to amoxicillin-clavulanate, azithromycin, ciprofloxacin and vancomycin was detected by both methods. Despite all interventions and patient receiving antimicrobial treatment including imipenem-cilastatin, amikacin, and trimethoprim-sulfamethoxazole, the course and outcome of infection was unfavourable. CONCLUSION: We would like to emphasize the need to consider the possibility of disseminated Nocardia infection in immunocompromised patients, especially in patients receiving long-term corticosteroid treatment with skin infections and/or cavitary lung lesions, especially if these do not improve with standard antimicrobial treatment. Precise species identity provides a critical guide for physicians in the choice of targeted treatment. Thanks to MALDI-TOF MS, Nocardia spp. identification is now available in routine lab work. WGS is still inevitable for the identification of uncommon and novel species due to the high sequence similarities between closely related species and the genetic diversity of that genus.

Large Anthrax Outbreak in a New Locality in Croatia, 2022.

Bacillus anthracis is a well-known zoonotic pathogen that can cause disease in both animals and humans. Moreover, it has a high bioterrorism potential as its lethal spores are resistant to inactivation, are easy to produce in large quantities, and are easily spread over large areas. Anthrax cases occur in different parts of the world, including most European countries. Specific areas of Croatia are long known as anthrax districts, but with sporadically reported cases over the years. Here, we present a major outbreak of animal and human anthrax in the region of Lonjsko Polje in Croatia, a region not known to have anthrax cases in the past. The outbreak started in July 2022 and lasted several months, but most human and animal cases were reported in the first month. During the outbreak, there were 17 reported human cases of cutaneous anthrax and 29 laboratory-confirmed animal cases. However, due to issues in reporting in animals and the late finding of the carcasses, which made laboratory diagnostics challenging, the actual number of animal cases was probably significantly higher.