Evolution of Antimicrobial Resistance Levels of ESKAPE Microorganisms in a Peruvian IV-Level Hospital

Abstract

Backgound: The members of the so-called ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) are a frequent cause of severe infection, ranking among the most relevant causes of hospital infections. In Peru, few studies, often focused in a single ESKAPE microorganism, have been performed, but none providing an overall and comprehensive long-time analysis of the antibiotic resistance of ESKAPE microorganisms. In the present study, the evolution of antimicrobial resistance levels of ESKAPE microorganisms isolated during 2009 - 2010 (Period 1) and 2012 - 2014 (Period 2) in a IV-level hospital in Lima was analyzed.

Materials and methods: ESKAPE microorganisms were isolated from inpatients clinical samples. Bacterial identification, as well as antimicrobial susceptibility levels for up to 29 antimicrobial agents and presence of Extended-Spectrum β-Lactamases (only established in K. pneumoniae) were determined using automatic methods.

Results: Of 9,918 clinical isolates, 1,917/3,777 (50.8%) [JAN/2009-JUN/2010 (Period 1)] and 4764/6141 (46.4%) [JAN/2012-DEC/2014 (Period 2)] belonged to the ESKAPE group (P <0.0001). ESKAPE were more frequent in the intensive care unit (ICU) (P <0.0001). E. faecium decreased from 5.1% to 4.1% (P <0.5), S. aureus from 10.5% to 7.0% (P <0.05), and P. aeruginosa from 12.9% to 11.6% (P <0.05), while, A. baumannii increased from 5.0% to 6.7% (P <0.05), mainly related to an increase in ICU isolates (8.4% vs. 17.1%; P <0.05). Overall, high levels of antimicrobial resistance were detected, but with few exceptions (e.g. vancomycin in E. faecium), antibiotic resistance levels remained stable or lower in Period 2. Contrarily, A. baumannii showed significantly increased resistance to different cephalosporins, carbapenems and amoxicillin plus sulbactam.

Conclusion: The introduction of a successful extensively drug-resistant A. baumannii clone in the ICU is suspected. The isolation of ESKAPE and levels of antibiotic resistance levels have reduced over time.

Keywords: Acinetobacter baumannii; Intensive Care Unit; Klebsiella pneumoniae; Multidrug resistance; Pseudomonas aeruginosa.

Figure 1. Evolutive trends between the two study periods.

Blue, No significant differences; Green, Significant decrease; Red, Significant increase. M, medicine department; S, surgery department; I, intensive care unit; O, overall data; Ef, Enterococcus faecium; Sa, Staphylococcus aureus; Kp, Klebsiella pneumoniae; Ab, Acinetobacter baumannii; Pa, Pseudomonas aeruginosa; Ent, Enterobacter spp.; PEN, penicillin; AMP, ampicillin; OXA, oxacillin; CFZ, cefazolin; CTX, cefotaxime; CRO, ceftriaxone; CAZ, ceftazidime; FEP, cefepime; AMC, amoxicillin-clavulanic; SAM, ampicillin-sulbactam; TZP, piperacillin-tazobactam; ATM, aztreonam; IPM, imipenem; MEM, meropenem; ETP, ertapenem; GEN, gentamicin; AMK, amikacin; STR, streptomycin; TET, tetracycline; RIF: rifampicin; CIP, ciprofloxacin; ERY, erythromycin; CLI, clindamycin; TMP/SMX, trimethoprim-sulfamethoxazole; VAN, vancomycin.