Please use this identifier to cite or link to this item:
https://www.arca.fiocruz.br/handle/icict/63953
DIFFICULTIES IN IDENTIFYING ACTINOMYCETOTA STRAINS ISOLATED FROM AN IMMUNOBIOLOGICAL PRODUCER IN RIO DE JANEIRO BY VITEK 2
Author
Affilliation
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Abstract
Introduction: Actinomycetota is a Phylum that comprehends Gram-positive bacteria that exhibits a wide
morphological variety of coccoid or coccoid rod to fragmented hyphal forms or branched mycelium.
These characteristics cause great difficulty in classifying these microorganisms using Gram staining,
as they can easily be confused with the Bacillaceae family. The semi-automated VITEK®2 system,
which brings together a series of biochemical tests, has been used for microbial identification in the
pharmaceutical industry. However, methodologies based on Gram, as is the case with this system, can
result in misidentifications if the card chosen for analysis is wrong.
Objectives: To evaluate the Actinomycetota rods identification using the VITEK®2 system. Identification
by full 16S rRNA gene sequencing, which is considered the gold standard for species delineation, was
used as a standard.
Methodology: Twenty-nine isolates were selected from an immunobiological producer in Rio de Janeiro,
obtained from 2013 to 2020. Identification by VITEK®2 was carried out according to the manufacturer’s
instructions, using GP and BCL cards, whose databases do not include Actinomycetota phylum bacteria.
For full 16S rRNA gene sequencing, the MicroSEQ TM Full Gene 16S rDNA kit was used, according to
the manufacturer’s instructions.
Results: Nineteen (65.5%) isolates were identified at the genus level and 10 (34.5%) at the species level of
Actinomycetota, with the use of full 16S rRNA gene sequencing. VITEK®2, as expected, did not identify
15 (51.7%) and 17 (58.6%) isolates with the GP and BCL card, respectively. However, both cards led to
misidentifications. For seven (24.1%) and 12 (41.4%) isolates, with GP and BCL card, respectively, the
identification reached genera/species belonging to the Phylum Bacillota, which differed from the standard
identification.
Conclusion: We can conclude that, with the use of VITEK®2 with GP and BCL cards, Actinomycetota
rods can be misidentified as rods from the Phylum Bacillota, which can compromise preventive and
corrective actions in the industry.
Share