The effect of varying multidrug-resistence (MDR) definitions on rates of MDR gram-negative rods

Abstract

BackgroundA multitude of definitions determining multidrug resistance (MDR) of Gram-negative organisms exist worldwide. The definitions differ depending on their purpose and on the issueing country or organization. The MDR definitions of the European Centre for Disease Prevention and Control (ECDC) were primarily chosen to harmonize epidemiological surveillance. The German Commission of Hospital Hygiene and Infection Prevention (KRINKO) issued a national guideline which is mainly used to guide infection prevention and control (IPC) measures. The Swiss University Hospital Zurich (UHZ) – in absentia of national guidelines – developed its own definition for IPC purposes. In this study we aimed to determine the effects of different definitions of multidrug-resistance on rates of Gram-negative multidrug-resistant organisms (GN-MDRO).MethodsMDR definitions of the ECDC, the German KRINKO and the Swiss University Hospital Zurich were applied on a dataset comprising isolates of Escherichia coli, Klebsiella pneumoniae, Enterobacter sp., Pseudomonas aeruginosa, and Acinetobacter baumannii complex. Rates of GN-MDRO were compared and the percentage of patients with a GN-MDRO was calculated.ResultsIn total 11′407 isolates from a 35 month period were included. For Enterobacterales and P. aeruginosa, highest MDR-rates resulted from applying the ‘ECDC-MDR’ definition. ‘ECDC-MDR’ rates were up to four times higher compared to ‘KRINKO-3/4MRGN’ rates, and up to six times higher compared to UHZ rates. Lowest rates were observed when applying the ‘KRINKO-4MRGN’ definitions. Comparing the ‘KRINKO-3/4MRGN’ with the UHZ definitions did not show uniform trends, but yielded higher rates for E. coli and lower rates for P. aeruginosa. On the patient level, the percentages of GN-MDRO carriers were 2.1, 5.5, 6.6, and 18.2% when applying the ‘KRINKO-4MRGN’, ‘UHZ-MDR’, ‘KRINKO-3/4MRGN’, and the ‘ECDC-MDR’ definition, respectively.ConclusionsDifferent MDR-definitions lead to considerable variation in rates of GN-MDRO. Differences arise from the number of antibiotic categories required to be resistant, the categories and drugs considered relevant, and the antibiotic panel tested. MDR definitions should be chosen carefully depending on their purpose and local resistance rates, as definitions guiding isolation precautions have direct effects on costs and patient care.

Antimicrobial Susceptibility Testing for Salmonella Serovars Isolated from Food Samples: Five-Year Monitoring (2015–2019)

“…The break point for resistance or susceptibility interpretation to each antibiotic was in accordance with the CLSI standards. In the evaluation of the results, the strains displaying intermediate resistance were regarded as resistant, and the strains displaying resistance to at least three antibiotic classes were considered multidrug resistant (MDR) [ 22 , 23 ].…”

Impact of Colistin Dosing on the Incidence of Nephrotoxicity in a Tertiary Care Hospital in Saudi Arabia

“…The data collected included baseline demographic information; colistin dosing and duration of therapy; concomitant antibiotic administration; and laboratory findings such as albumin, hemoglobin, white blood cell, and serum creatinine levels (evaluated at baseline, peak (if AKI occurred), and the end of colistin treatment). We also recorded isolates of the bacterial cultures and susceptibility patterns to various antimicrobial agents and defined MDR organisms for Enterobacterales, A. baumannii complex, and P. aeruginosa as the resistance to three or more classes of antimicrobials [ 20 ]. Patients who developed AKI were followed up for 3 months after the end of colistin treatment to evaluate its reversibility.…”

<p>The First Egyptian Report Showing the Co-Existence of <em>bla</em>_NDM-25, <em>bla</em>_OXA-23, <em>bla</em>_OXA-181, and <em>bla</em>_GES-1 Among Carbapenem-Resistant <em>K. pneumoniae</em> Clinical Isolates Genotyped by BOX-PCR</p>

“…1,4 According to the definition proposed by the Center for Disease Control and Prevention (CDC), K. pneumoniae is considered to be MDR when it exhibits resistance to at least one agent in three or more classes of antimicrobial agents. 5 Extensive drug resistance (XDR) corresponds to MDR isolates that develop resistance to all antibiotic groups except for two or fewer classes. 6 Pan drug resistance (PDR) corresponds to XDR isolates that develop resistance to all antibiotics, including polymyxin and tigecycline.…”

“…Representative DNA fingerprint pattern generated by BOX-PCR for carbapenem-resistant K. pneumoniae clinical isolates. L, 100 bp DNA ladder; lanes 3, 4,5,6,7,8,9,10,11,12,13,14,15,16,17, and 18 are the code No. of CRKP clinical isolates.…”