Abstract
(
) is one of the most important nosocomial pathogens responsible for a wide range of infections.
This study aimed to investigate the existence of the plasmidic genes encoding for aminoglycoside modifying enzymes (AMEs), 16S rRNA methyltransferases (RMT), and the altered dihydropetroate synthase (DHPS) encoded by the
gene among
clinical isolates collected from Taif, Kingdom of Saudi Arabia (KSA). The mutations in
and
genes were also investigated.
Forty
clinical isolates were investigated for their susceptibility to ten antibiotics. The plasmid DNA was extracted and screened for nine genes encoding for aminoglycoside resistance in addition to the
gene. The clonal relatedness was determined by random amplified polymorphic DNA (RAPD)-PCR. Mutation in
and the
genes were detected by capillary electrophoresis sequencing (CES).
All isolates were
in which 42.5% of them exhibited a high level of aminoglycoside resistance (HLAR). The most prevalent AMEs and RMT encoding genes were
, the two
gene variants [
and
],
and
in which 90%, 87.5%, 85%, and 45% of isolates tested positive, respectively. The other investigated aminoglycoside resistant encoding genes, namely
, and rmtB, were not detected. Only 15% of isolates harbored the
gene. RAPD-PCR classified the 40 isolates into three clusters in which cluster II was the main cluster. DNA sequencing revealed that 34.29% (12/35) of isolates tested positive for
were found to harbor a common missense mutation in position 102 indicating a novel allelic variant named
. Also, DNA sequencing revealed three missense mutations in the
gene.
This is the first Saudi study to investigate the plasmid borne aminoglycoside and sulfonamide resistance genes among
clinical isolates. A novel allelic variant for
was detected in addition to novel mutations in the
gene.