MALDI-TOF MS for identification of Tsukamurella species: Tsukamurella tyrosinosolvens as the predominant species associated with ocular infections

Abstract

Although Tsukamurella infections have been increasingly reported in Europe, Asia, America, and Africa, indicating that diseases caused by this group of bacteria are emerging in a global scale, species identification within this genus is difficult in most clinical microbiology laboratories. Recently, we showed that groEL gene sequencing is useful for identification of all existing Tsukamurella species. Nevertheless, PCR sequencing is still considered expensive, time-consuming, and technically demanding, and therefore is yet to be incorporated as a routine identification method in clinical laboratories. Using groEL gene sequencing as the reference method, 60 Tsukamurella isolates were identified as five different Tsukamurella species [T. tyrosinosolvens (n = 31), T. pulmonis (n = 25), T. hongkongensis (n = 2), T. strandjordii (n = 1), and T. sinensis (n = 1)]. The most common source of the patient isolates were the eye (n = 18), sputum (n = 6), and blood (n = 6). None of the 60 isolates were identified correctly to species level by MALDI-TOF MS with the original Bruker database V.6.0.0.0. Using the Bruker database extended with 15 type and reference strains which covered all the currently recognized 11 Tsukamurella species, 59 of the 60 isolates were correctly identified to the species level with score ≥2.0. MALDI-TOF MS should be useful for routine species identification of Tsukamurella in clinical microbiology laboratories after optimization of the database. T. tyrosinosolvens was the most common species observed in patients with Tsukamurella infections and the predominant species associated with ocular infections.

The application of proteomic methods (MALDI-toff MS) for studying protein profiles of some nematodes (dirofilaria and ascaris) for differentiating species

“…This leads to a reduction in analysis time, early results of the identification of pathogens and, as a consequence, improvement in clinical care (Lavigne et al, 2013;Theparee et al, 2018;Carbonnelle et al, 2011). This method of identification is comparable in accuracy with the full genome studies (Teng et al, 2018). The important advantage of MALDI-toff MS is its implementability to determine the resistance of microorganisms to antibiotics, disinfectants and the toxin production of pathogens (Hrabák et al, 2013;Burckhardt and Zimmermann, 2011;Lasserre et al, 2015;Carbonnelle et al, 2011).…”

Emergence of Staphylococcus lugdunensis as a Cause of Urinary Tract Infection: Results of the Routine Use of MALDI-TOF MS

“…The marked increase in the detection of S. lugdunensis isolates in urine samples since 2014 coincided with the commencement of using MALDI-TOF MS for rapid bacterial identification in our clinical microbiology laboratory. The use of MALDI-TOF MS has facilitated the identification of a number of bacteria in our laboratory, such as Burkholderia pseudomallei, Laribacter hongkongensis, and Tsukamurella species [8][9][10]. This method not only increases the number of cases diagnosed but also shortens the time to diagnosis.…”

“…The methodology is easy to follow, requires only a minimal amount of bacteria for the analysis, and provides results within minutes. Therefore, it has now been integrated into many clinical laboratories and is useful for the identification of different groups of medically important bacteria [8][9][10]. Since the start of the routine use of MALDI-TOF MS in our clinical microbiology laboratory in January 2014, we have observed an unprecedented surge of S. lugdunensis isolates identified in urine samples of our patients.…”

Tsukamurella pulmonis conjunctivitis in patients with an underlying nasolacrimal duct obstruction – report of two cases

“…In addition, differential colony morphological diagnosis of Gordonia species, Williamsia species, and rapid growing Mycobacteria (e.g. M. abscessus, M. chelonae, and, M. fortuitum) should be performed using MS [9] and 16S rRNA gene sequencing.…”