Lack of correlation between reduced outpatient consumption of macrolides and macrolide resistance of invasive Streptococcus pneumoniae isolates in Slovenia during 1997–2017

• Published in: Journal of global antimicrobial resistance. 2019-03, Vol.16, p.242-248
• Main Authors: Kastrin, Tamara, Paragi, Metka, Erčulj, Vanja, Žohar Čretnik, Tjaša, Bajec, Tom, Čižman, Milan
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Anti-Bacterial Agents - administration & dosage; Anti-Bacterial Agents - pharmacology; Antibiotic consumption; Child; Child, Preschool; Drug Resistance, Multiple, Bacterial; Drug Utilization; Humans; Infant; Infant, Newborn; Macrolides; Macrolides - administration & dosage; Macrolides - pharmacology; mef(A); Microbial Sensitivity Tests; MLST; Outpatients; PFGE; Pneumococcal Infections - drug therapy; Pneumococcal Infections - microbiology; Slovenia; Streptococcus pneumoniae; Streptococcus pneumoniae - drug effects
• ISSN: 2213-7165; 2213-7173
• DOI: 10.1016/j.jgar.2018.10.022

•In Slovenia macrolide consumption decreased by 42.4% in the period 1997 to 2017.•The macrolide resistance of invasive pneumococci increased from 5.8% to 12.8%.•Spread of a clone explains the increased macrolide resistance among invasive pneumococci.•Reduced consumption of antibiotics is not enough to reverse microbial resistance. The objective of this study was to investigate the correlation between decreased national consumption of macrolides and resistance of invasive Streptococcus pneumoniae isolates in Slovenia during 1997–2017. A total of 4241 invasive S. pneumoniae isolates were collected in Slovenia from 1997 to 2017. The presence of erm(B), mef(E), mef(A) and erm(TR) genes was determined by PCR in 612 erythromycin-resistant isolates. Selected isolates carrying the mef(A) gene were further examined by pulsed-field gel electrophoresis (PFGE). Multilocus sequence typing (MLST) was performed for 161 erythromycin-resistant isolates from 2004 to 2009. Consumption of macrolides decreased by 42.5% between 1997 and 2017, and by 57.0% from the highest consumption during 1999 to 2017. Resistance of S. pneumoniae increased by 120.7% in the same period, from 5.8% in 1997 to 12.8% in 2017. The most prevalent serotypes among macrolide-resistant isolates were 14 (54.9%), 19A (9.0%), 19F (8.3%), 6B (7.2%), 6A (5.2%) and 9V (19; 3.0%). The most prevalent determinant of macrolide resistance in the observed period was erm(B) (43.0%; 263/612), followed by mef(A) (36.3%; 222/612) and mef(E) (14.9%; 91/612). During the study period, an increasing trend in serotype 14, mef(A)-carrying isolates was observed, with a peak in 2011 (P