Genetic relatedness and novel sequence types of clinical Aeromonas dhakensis from Malaysia

• Published in: Brazilian journal of microbiology Vol. 51; no. 3; pp. 909 - 918
• Main Authors: Lau, Tien Tien Vicky, Tan, Jin-Ai Mary Anne, Puthucheary, S. D., Puah, Suat-Moi, Chua, Kek-Heng
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-09-2020; Springer Nature B.V
• Subjects: Aeromonas; Aeromonas - classification; Aeromonas - genetics; Aeromonas - isolation & purification; Bacterial Fungal and Virus Molecular Biology - Research Paper; Biomedical and Life Sciences; DNA, Bacterial - genetics; Food Microbiology; Genes, Bacterial - genetics; Genes, Essential - genetics; Genetic analysis; Genetic diversity; Genetic Variation; Gram-Negative Bacterial Infections - epidemiology; Gram-Negative Bacterial Infections - microbiology; Humans; Life Sciences; Malaysia - epidemiology; Medical importance; Medical Microbiology; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Multilocus sequence typing; Mycology; Nucleotides; Peritoneal fluid; Peritoneum; Phylogenetics; Phylogeny; RecA protein; Sequence Analysis, DNA; Topology; Malaysia; Sequence types; Multilocus phylogenetic analysis; Genetic diversity; Clonal complex; Aeromonas dhakensis
• ISSN: 1517-8382; 1678-4405
• DOI: 10.1007/s42770-020-00239-8

Aeromonas dhakensis
is an emergent human pathogen with medical importance. This study was aimed to determine the sequence types (STs), genetic diversity, and phylogenetic relationships of different clinical sources of 47
A. dhakensis
from Malaysia using multilocus sequence typing (MLST), goeBURST, and phylogenetic analyses. The analysis of a concatenated six-gene tree with a nucleotide length of 2994 bp based on six housekeeping genes (
gyrB
,
groL
,
gltA
,
metG
,
ppsA
, and
recA)
and independent analyses of single gene fragments was performed. MLST was able to group 47
A. dhakensis
from our collection into 36 STs in which 34 STs are novel STs. The most abundant ST521 consisted of five strains from peritoneal fluid and two strains from stools. Comparison of 62 global
A. dhakensis
was carried out via goeBURST; 94.4% (34/36) of the identified STs are novel and unique in Malaysia. Two STs (111 and 541) were grouped into clonal complexes among our strains and 32 STs occurred as singletons. Single-gene phylogenetic trees showed varying topologies;
groL
and
rpoD
grouped all
A. dhakensis
into a tight-cluster with bootstrap values of 100% and 99%, respectively. A poor phylogenetic resolution encountered in single-gene analyses was buffered by the multilocus phylogenetic tree that offered high discriminatory power (bootstrap value = 100%) in resolving all
A. dhakensis
from
A. hydrophila
and delineating the relationship among other taxa. Genetic diversity analysis showed
groL
as the most conserved gene and
ppsA
as the most variable gene. This study revealed novel STs and high genetic diversity among clinical
A. dhakensis
from Malaysia.