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.
Highlights
Results groEL gene sequence analysis of Tsukamurella isolates Using groEL gene sequencing as the reference method, the 60 Tsukamurella isolates included in this study were identified as five different Tsukamurella species, including T. tyrosinosolvens (n = 31, 51.7%), T. pulmonis (n = 25, 41.7%), T. hongkongensis (n = 2, 3.3%), T. strandjordii (n = 1, 1.7%), and T. sinensis (n = 1, 1.7%)
Among the 25 T. pulmonis strains identified, 16 (64.0%) were isolated from the oral cavities of Chinese cobras while the remaining 9 (36.0%) were isolated from patients. groEL gene sequence analysis showed that intraspecies nucleotide identities among the 27 strains of T. tyrosinosolvens, the 25 strains of T. pulmonis and the two strains of T. hongkongensis ranged from 98.7 to 100.0%, 99.7 to 100.0% and 100.0%, respectively
Clinical spectra of Tsukamurella infections in Hong Kong Including the clinical isolates that we previously reported in our locality[1, 2, 34], the most common Tsukamurella species observed in our patients was T. tyrosinosolvens (n = 31), followed by T. pulmonis (n = 9), T. hongkongensis (n = 3), T. sinensis (n = 2), and T. strandjordii (n = 1)
Summary
Introduction yearsRecently, we have reclassified Tsukamurella spon-The genus Tsukamurella contains clinically relevant giae DSM 44990, Tsukamurella carboxydivorans JCM species and cases have been increasingly reported in 15482, and Tsukamurella sunchonesis JCM 15929 as laterEurope, Asia, America, and Africa, indicating a global heterotypic synonyms of Tsukamurella pulmonis, Tsudistribution of the bacteria[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]. Full list of author information is available at the end of the article result, only 11 Tsukamurella species should be included in this genus according to the current state of the taxonomy at the time of writing[21, 22]. Among these 11 species, 8 are known to be associated with human infections, with the most common infections being indwelling device-related infections, meningitis, pulmonary, and.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
