Naslov
Extended-spectrum beta-lactamases in Dubrovnik- Neretva County

Autori
Krilanović, Marija ; Beader, Nataša ; Bedenić, Branka ; Car, Haris

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
International Meeting on Emerging Diseases and Surveillance

Mjesto i datum
Beč, Austrija, 09.11.2018. - 12.11.2018

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
extended-spectrum beta-lactamases ; Enterobacteriaceae ; resistance

Sažetak
Background and aim Extended-spectrum β-lactamases- producing hydrolyze oxyimino-cephalosporins and aztreonam, are mostly produced by Enterobacteriacea, and are encoded on transferable plasmids which often contain resistance genes to non-β-lactam antibiotics. Plasmid-mediated AmpC β- lactamases descend from the chromosomal ampC gene transffered to the plasmid. Those β-lactamases confer resistance to first, second and third generation of cephalosporins, monobactams, and to β-lactam-β- lactamase inhibitor combinations. The first ESBL positive Enterobacteriaceae were characterized in Croatia in 1998. The first reports identified SHV-1 and SHV-5 in K. pneumoniae. Later studies revealed switch to CTX-M beta-lactamases, predominantly CTX-M-15. The majority of the earlier studies characterized ESBL sin the large hospital centers in Croatia. However, there were no reports from Dubrovnik- Neretva County, sequestred area, located in South- East geographic region of Croatia. Recently, an increase of ESBL positive organisms was notified in the Public Health Institute of Dubrovnik- Neretva County and the isolates were sent to University Hospital Center Zagreb for analyis of resistance mechanisms. Material and methods Sixty- nine extended-spectrum β-lactamases- producing Enterobacteriacea strains were isolated in Public Health Institute of Dubrovnik- neretva county during the period April 2015 - April 2016. There were 44 E.coli, 17 K.pneumoniae and 8 Enterobacter cloacae. The antibiotic susceptibility was determined by the broth microdilution method according to CLSI standards. The double disk synergy test (DDST) and the CLSI combined disk test with addition of clavulanic acid were performed to detect ESBLs. Chromosomal or plasmid- mediated AmpC β-lactamases were detected by combined disk test using cephalosporin disks with 3- aminophenylboronic acid (PBA). All isolates showed high level of resistance to expanded- spectrum cephalosporins, Results All 44 E.coli isolates showed resistance to amoxicillin, cefuroxime, cefriaxone, ceftizoxime, ceftazidime and cefepime. High level resistance was noticed also for gentamicin (75%) and ciprofloxacin (97, 8%). Imipenem and meropenem were sensitive in all tested isolates. All 17 K. pneumonie isolates showed resistance to amoxicillin, cefuroxime, cefriaxone, ceftizoxime, ceftazidime, cefepime, gentamicin and ciprofloxacine. High level resistence is showed also to piperacilin- tazobaktam (76%). Imipenem and meroenem showed susceptibility. E. cloacae isolates showed resistance to amoxicillin, cefuroxime, cefriaxone, ceftizoxime, ceftazidime and cefepime. High level resistance is showed also to gentamicin (87%) , ciprofloxacin (87%) and piperacilin-tazobaktam (75%). Five of eight isolates showed resistance to meropenem, and four od eight isolates showed resistance to imipenem. All isolates tested positive in DDST and combined disk test indicating the production of an ESBL. PCR revealed that group 1 CTX-M in all isolates, with majority of them harbouring also TEM-1. WGS revealed the presence of resistence gene in non-β- lactam antibiotics: aminoglycosides, teracyclines, trimethoprim, suphonamides, fluoroquinolones and chloramphenicol in addition to blaCTX-M genes. Conclusions Four different plasmid-incompatibility groups were found: X, L/M, N and FIA among E. coli isolates whereas two different plasmid- incompatibility groups were found: L/M and A/C in K.pneumoniae. One plasmid type was found in E. cloacae: L/M. The isolates showed high level of genetic variability and beloged all to different clusters.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti, Kliničke medicinske znanosti

POVEZANOST RADA