Background
The population of new patients with end-stage kidney disease (ESKD)
receiving dialysis in Taiwan increased from 10,697 in 2013 to 11,596 in
2016. According to the 2018 Annual Report on Kidney Disease in Taiwan,
the proportion of new patients with ESKD receiving hemodialysis was
88.9% in 2013, but it increased to 89.7% in 2016. The establishment of
a well-functioning vascular access (VA) procedure is fundamental to
enabling patients to undergo an efficient hemodialysis procedure.
Although infection related to VA is not common, it is a problematic
complication that may lead to
access loss, sepsis, and even
death. The major types of VA conduits commonly used are native
arteriovenous fistulas (AVFs), prosthetic arteriovenous grafts (AVGs),
and central venous catheters (CVCs; both temporary and cuffed tunneled).
AVFs and AVGs are preferred over CVCs for dialysis access because CVCs
expose patients undergoing hemodialysis to an increased risk of
healthcare-associated infections (1). Pathogens primarily responsible
for CVC-related infections are Staphylococcus , Gram-negative
enteric bacilli, Pseudomonas aeruginosa , and Candida spp.
These pathogens can form a biofilm on the CVC walls, rendering them
strongly resistant to antibiotic action (2). The mechanism underlying VA
infections (VAIs) generally involves the migration of surface organisms
along the external surface of the catheter from the exit-site wound or
through the lumen of the catheter. Staphylococcus aureus and
coagulase-negative staphylococcus (CoNS) species are the most frequently
isolated bacteria from VAIs.
S. aureus is among the most common causes of both endemic and
epidemic infections acquired in hospitals. Patients undergoing
hemodialysis are frequently exposed to S. aureus during their
stay in dialysis centers, hospitals, or rest homes; the VA site for
hemodialysis is a potential site of entry for the pathogen, and the risk
of infection is particularly high when a CVC is used (3, 4).
Furthermore, recent research has reported that CoNS species as the most
common etiology of nosocomial bloodstream infection (BSI), especially
CVC-related BSI (CRBSI), in hospitalized patients (5-7).
P. aeruginosa is a major cause of nosocomial infection,
particularly in immunocompromised patients. It has a predilection for
moist environments that serve as its natural reservoirs; therefore,P. aeruginosa is a common pathogen in graft infection (8, 9).
We conducted a 5-year single-institution study to (1) investigate the
prevalence of bacterial species from VAI (2) determine the molecular
characteristics of different bacterial species isolated from various
types of VAIs, and (3) establish the correlation between bacterial
species, sequence types (STs), and VAI types.