Antibiotic resistance rates for Pseudomonas aeruginosa clinical respiratory and bloodstream isolates among the Veterans Affairs Healthcare System from 2009 to 2013

Abstract

Pseudomonas aeruginosa is a major cause of healthcare-associated infections and resistance among isolates is an increasing burden. The study purpose was to describe national resistance rates for clinical P. aeruginosa respiratory and bloodstream cultures and the prevalence of multidrug-resistant (MDR) P. aeruginosa within the Veterans Affairs (VA). MDR was defined as non-susceptibility to at least one drug in at least 3 of the following 5 categories: carbapenems, extended-spectrum cephalosporins, aminoglycosides, and piperacillin/tazobactam. We reviewed 24,562 P. aeruginosa respiratory and bloodstream isolates across 126 VA facilities between 2009 and 2013. Most isolates were collected from inpatient settings (82%). Resistance was highest in fluoroquinolones (33%) and exceeded 20% for all classes assessed (carbapenems, extended-spectrum cephalosporins, aminoglycosides, and piperacillin/tazobactam). Resistance was higher in inpatient settings and in respiratory isolates. Prevalence of MDR was 20% overall (22% for inpatient isolates, 11% outpatient, 21% respiratory, 17% bloodstream). Our findings are consistent with previous surveillance reports.

Keywords: Multidrug-resistance; Pseudomonas aeruginosa; Resistance.

Fig. 1.

P. aeruginosa Antibiotic Resistance Among Veterans Affairs Inpatient Facilities by CDC Region. AMG = Aminoglycosides; CDC = Centers for Disease Control and Prevention; E N Central = East North Central Region; E S Central = East South Central Region; ES Ceph = Extended-spectrum cephalosporin; FQ = Fluoroquinolone; MDR = Multidrug resistant; Mid Atlantic = Middle Atlantic Region; Mountain = Mountain Region; New England = New England Region; Pacific = Pacific Region; PIP = Piperacillins; S Atlantic = South Atlantic Region; W N Central = West North Central Region; W S Central = West South Central Region Data are % non-susceptible (total number of isolates tested). Not every antibiotic category tested for every isolate tested. Extended-spectrum cephalosporins category included ceftazidime and cefepime. Fluoroquinolones category included levofloxacin and ciprofloxacin. Aminoglycosides category included amikacin, gentamicin, and tobramycin. Carbapenems category included imipenem, meropenem, and doripenem. Piperacillins included piperacillin and piperacillin/tazobactam. CDC MDR was defined as non-susceptibility to at least one agent in at least three of the following 5 categories: aminoclycosides, carbapenems, extended-spectrum cephalosporins, fluoroquinolones, and piperacillins.

Fig. 2.

P. aeruginosa Antibiotic Resistance Among Veterans Affairs Outpatient Facilities by CDC Region. AMG = Aminoglycosides; CDC = Centers for Disease Control and Prevention; E N Central = East North Central Region; E S Central = East South Central Region; ES Ceph = Extended-spectrum cephalosporin; FQ = Fluoroquinolone; MDR = Multidrug resistant; Mid Atlantic = Middle Atlantic Region; Mountain = Mountain Region; New England = New England Region; Pacific = Pacific Region; PIP = Piperacillins; S Atlantic = South Atlantic Region; W N Central = West North Central Region; W S Central = West South Central Region Data are % non-susceptible (total number of isolates tested). Not every antibiotic category tested for every isolate tested. Extended-spectrum cephalosporins category included ceftazidime and cefepime. Fluoroquinolones category included levofloxacin and ciprofloxacin. Aminoglycosides category included amikacin, gentamicin, and tobramycin. Carbapenems category included imipenem, meropenem, and doripenem. Piperacillins included piperacillin and piperacillin/tazobactam. CDC MDR was defined as non-susceptibility to at least one agent in at least three of the following 5 categories: aminoclycosides, carbapenems, extended-spectrum cephalosporins, fluoroquinolones, and piperacillins.