Rapid identification of Nocardia cyriacigeorgica from a brain abscess patient using MALDI-TOF-MS

Abstract

Nocardia cyriacigeorgica (N. cyriacigeorgica) is most frequently associated with human infections, including chronic bronchitis, pulmonary disease and brain abscesses. In general, N. cyriacigeorgica causes infections in immunocompromised individuals and has been reported in clinical samples worldwide. However, the isolation and speciation of N. cyriacigeorgica in the routine diagnostic microbiology laboratory are complicated and time consuming. Recent mass spectrometry techniques such as matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry (MALDI-TOF-MS) have been successfully integrated into many routine diagnostic microbiology laboratories, allowing for the rapid, accurate and simple identification and speciation of many different microorganisms, including difficult-to-identify bacterial species. Here, we present a case report of a 65-year-old female patient from the neurology ward of Prince Sultan Military Medical City in Riyadh, Saudi Arabia, who was infected with N. cyriacigeorgica. The bacterium was successfully identified by MALDI-TOF-MS, with species identification subsequently confirmed by sequence analysis of the 16S ribosomal RNA.

A post-transplant infection by Nocardia cyriacigeorgica

“…An accurate diagnosis was made because of the cultures; after which, treatment was initiated promptly to deal with infection. MALDI-TOF MS test, wherever applicable, can be used to diagnose such cases, as it gives fast and reliable results for such difficult-to-diagnose pathogens [16]. Prophylactic treatment for Nocardia usually involves long-term co-trimoxazole.…”

Brain Abscesses by Nocardia: An Interesting Case

“…Nocardia species are slow-growing bacteria and can be difficult to culture in a laboratory. Molecular diagnosis utilizing techniques such as matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALD-TOF MS) for 16S ribosomal RNA gene sequencing is now available and a very reliable alternative for the rapid identification of bacteria from the aspirate [ 5 ]. The lungs (60%) and skin (21%) are the primary sites of infection in the majority of the cases of nocardiosis.…”