We describe two cases of uncomplicated pharyngitis caused by hypervirulent Klebsiella pneumoniae (hvKp) in a family, initially in an immunocompetent adolescent, followed by possible household spread resulting in similar presentations in the patient's parent. Genomic analysis confirmed hvKp from the two cases were genetically identical and typed as K2-ST3252. Nasopharyngeal carriage and respiratory secretion/droplet may play an important yet underrecognized role in the transmission of hvKp. Enhancing routine screening for hvKp in the upper respiratory culture, followed by genotyping provides an effective pathway for early diagnosis.

We report a rare case of mycetoma after renal transplant in a patient with distant exposure to mangroves during disaster relief efforts in the Caribbean. Histopathology and fungal culture from the skin biopsy revealed findings consistent with chronic mycetoma caused by a dematiaceous mold. Next Generation Sequencing (NGS) identified the organism as closely related to Raghukumaria keshaphalae, a fungus originally isolated from mangroves. This case highlights the emerging threat posed by environmental dematiaceous fungi as obscure opportunistic pathogens in the setting of natural disasters, especially for immunocompromised patients, and the pivotal diagnostic role of NGS in invasive fungal infections.

Background

Carbapenemase-producing carbapenem-resistant Pseudomonas aeruginosa (CP-CRPA) is a major public health threat due to limited treatment options and high transmissibility. Though widespread globally, few instances of locally transmitted New Delhi metallo-β-lactamase (NDM)-producing CP-CRPA have been documented in the United States. Here, a cluster of locally transmitted NDM-1 CP-CRPA infections in Southern California is reported.

Methods

Epidemiologic investigations involving both patient screening and environmental surveillance by microbiological culture, carbapenemase testing, and bacterial whole-genome sequencing were conducted.

Results

Through extensive epidemiologic investigations, a sink environmental reservoir was identified. A genetically unique strain of NDM-CRPA was identified to be transmitted among seven patients in a single hospital over the course of 1.5 years. Changes in antimicrobial resistance genes harbored by a mobile genetic element were identified between the index and later cases, and the gene encoding NDM-1 resided within a mobile genetic element on the chromosome displaying evidence of widespread transmission between different species. Several interventions were implemented, including sink P-trap replacement and disinfectant against Pseudomonas biofilms. No additional cases were identified after the interventions.

Conclusions

Implementation of real-time pathogen surveillance enabled effective response to an ongoing outbreak that involved environmental sampling, microbiological testing, whole-genome sequencing, facility management, and updated infection prevention policies.