Molecular characterization of clinical isolates from vascular access
infection: A single institution study
Abstract
Hemodialysis requires repeated, reliable access to the systemic
circulation; therefore, a well-functioning vascular access (VA)
procedure is crucial for stable hemodialysis. VA infections (VAIs)
constitute the most challenging complication and cause considerable
morbidity, loss of access, and even death. In this study, we
investigated the molecular profiles of different bacterial isolates
retrieved from various types of VA grafts. We collected clinical
isolates from hemodialysis patients with VAIs in our institution for the
period between 2013 and 2018. We identified the bacterial isolates using
standard biochemical procedures; we used a polymerase chain reaction for
coagulase-negative staphylococcus (CoNS) and Burkholderia cepacia
complex (BCC) species identification. The antibiotic resistance and
molecular profile were analyzed using the disk diffusion method and
multilocus sequence typing, respectively. We studied 150 isolates
retrieved from patients with VAI and observed that Staphylococcus aureus
was the predominant bacterial species, followed by S. argenteus, BCC,
and CoNS. According to multilocus sequence typing data, we identified a
wide variety of sequence types (STs) in S. aureus isolates, with ST59,
ST45, and ST239 being the predominant types. Burkholderia cepacia with
two new ST types, namely ST1723 and ST1724, accounted for most of the
BCC infections, along with ST102 B. contaminans, which were mainly
isolated from infected tunneled-cuffed catheters. In summary, the
increased incidence of S. argenteus and BCC infections provides insights
into their potential clinical effects in VAIs. The various STs
identified in different bacterial species indicate the high genetic
diversity of bacterial species isolated from VAIs in our institution.