Multidrug-Resistant Corynebacterium striatum Associated with Increased Use of Parenteral Antimicrobial Drugs

Abstract

Corynebacterium striatum is an emerging multidrug-resistant bacteria. We retrospectively identified 179 isolates in a clinical database. Clinical relevance, in vitro susceptibility, and length of parenteral antimicrobial drug use were obtained from patient records. For patients with hardware- or device-associated infections, those with C. striatum infections were matched with patients infected with coagulase-negative staphylococci for case–control analysis. A total of 87 (71%) of 121 isolates were resistant to all oral antimicrobial drugs tested, including penicillin, tetracycline, clindamycin, erythromycin, and ciprofloxacin. When isolated from hardware or devices, C. striatum was pathogenic in 38 (87%) of 44 cases. Patients with hardware-associated C. striatum infections received parenteral antimicrobial drugs longer than patients with hardware-associated coagulase-negative staphylococci infections (mean ± SD 69 ± 5 days vs. 25 ± 4 days; p<0.001). C. striatum commonly shows resistance to antimicrobial drugs with oral bioavailability and is associated with increased use of parenteral antimicrobial drugs.

Keywords: Corynebacterium striatum; antimicrobial resistance; bacteria; multidrug resistance; parenteral antimicrobial drugs.

Figure 1

Patients infected with Corynebacterium striatum, by specimens isolated from a particular anatomic site, at the University of Washington Medical Center, Seattle, Washington, USA, 2005–2014. Hardware, surgical specimen obtained from a location anatomically in connection with a foreign device; BAL, bronchoalveolar lavage; urine, specimen isolated from a urine sample (we were unable to determine presence or absence of a catheter); surgical site, deep surgical specimen; skin, wound swab from a nonsurgical superficial specimen.

Figure 2

Numbers (A) and percentages (B) of Corynebacterium striatum isolates from patients at the University of Washington Medical Center, Seattle, Washington, USA, 2005–2014, with a multidrug-resistant phenotype for all antimicrobial drugs tested (penicillin, ciprofloxacin, clindamycin, erythromycin, and tetracycline). Inpatient or outpatient indicates clinical setting in which cultures were performed.

Figure 3

Length of use of parenteral intravenous antimicrobial drugs in matched case−control analysis of Corynebacterium striatum isolates and isolates of coagulase-negative staphylococci in patients with hardware-associated infections, University of Washington Medical Center, Seattle, Washington, USA, 2005–2014. Horizontal lines within boxes indicate median values, whiskers indicate minimum and maximum values, and boxes indicate 25th and 75th percentiles. Mean durations of parenteral antimicrobial drug use for patients infected with C. striatum and those infected with coagulase-negative staphylococci were compared by using the Mann-Whitney U test. CoNS, coagulase-negative staphylococci.