MALDI-TOF MS contribution to diagnosis of melioidosis in a nonendemic country in three French travellers

Abstract

Melioidosis is an endemic disease in Southeast Asia and northern Australia. An increasing number of cases are being reported in nonendemic countries, making the diagnosis less obvious. We discuss the identification of Burkholderia pseudomallei using matrix-assisted desorption ionization–time of flight mass spectrometry on the occasion of recent cases of imported melioidosis in French travellers.

The Brief Case: A Traveler’s Tale—Burkholderia pseudomallei Infection in a Cystic Fibrosis Patient

“…MALDI-TOF MS incorrectly identified this organism as Burkholderia thailandensis (albeit at a suboptimal rating), which is genetically closely related to B. pseudomallei but is nonpathogenic in humans. Misidentification of B. pseudomallei by the Bruker MALDI-TOF MS has been well described in the literature (1,5,(14)(15)(16). In this case, the Public Health England UK antimicrobial resistance and health care-associated infections reference unit, opportunistic pathogens section based in Colindale, London, used a species-specific PCR to identify this organism and performed susceptibility testing in a BSL3 facility (2,3).…”

“…As B. pseudomallei can be acquired through inhalation, all culture plates for suspected or confirmed cases should be handled by trained personnel with the appropriate personal protective equipment (PPE). Respiratory protection must be used during centrifugation because of the potential to generate aerosols and transmit infection (3,5,10,(13)(14)(15)(16). Sealed cups should be used in all centrifuges, and these should be opened only in a biologic safety cabinet (5).…”

Identification of Burkholderia pseudomallei by Use of the Vitek Mass Spectrometer

“…Previous methods of B. pseudomallei identification have been plagued by inaccuracy, prolonged turnaround time, and cost (1,12,26,34). Mass spectrometry identification of organisms has increased over time and is now a standard in many laboratories worldwide.…”

“…Using the Bruker standard database, the result may only be accurate to the genus level or the isolate may be misidentified as B. thailandensis. On this platform, the security-relevant library, which includes potential agents of bioterrorism, can identify B. pseudomallei (25)(26)(27). In-house Bruker MS reference libraries have been created and found to be accurate in the identification of B. pseudomallei from both primary isolates and directly from blood cultures (28,29).…”

Erreurs d'identification des agents biologiques à cote de sécurité élevée du groupe de risque 3 par SM MALDI-TOF au Canada : de novembre 2015 à octobre 2017

“…Des études ont indiqué que l'identification erronée des microorganismes par SM MALDI-TOF semble être attribuable à l'incomplétude des bases de données de référence utilisées (2,(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26). Deux types de bases de données de référence sont actuellement utilisées au Canada : les bases de données cliniques, contenant les spectres approuvés par Santé Canada, et les bases de données de recherche, qui contiennent un plus vaste ensemble de spectres, mais dont l'application clinique n'a pas été autorisée.…”