Retrospective study of genetic diversity of Acinetobacter baumannii -resistant strains isolated from patients in Riga East University Hospital in Latvia

Affiliations are different in Web of Science database and original journal publication. Here are given affiliations from original publication in Proceedings of the Latvian Academy of Sciences, Section B: Natural Exact and Applied Sciences.publishersversionPeer reviewe

Antimicrobial resistance and molecular biology of Acinetobacter baumannii isolates

MedicīnaVeselības aprūpeMedicineHealth CareA. baumannii ir aeroba gramnegatīvā baktērija, kas izraisa ar veselības aprūpi saistītas infekcijas. A. baumannii rezistence ietekmē ar veselības aprūpi saistītu infekciju izplatību. Patogēno baktēriju molekulārā analīze ir nopietns līdzeklis, lai uzlabotu infekcijas kontroles pasākumus pret A. baumannii ar kombinētu rezistenci. Mērķis ir analizēt A.baumannii infekcijas gadījumus, antimikrobiālo rezistences profilu un raksturot molekulāros bioloģiskos parametrus atbilstoši infekcijas tipam. Šis pētījums tika veikts Rīgas Austrumu klīniskā universitātes slimnīcā laikā no 2015. līdz 2017. gadam. Izolātus ieguva no pacientiem ar mikrobioloģiski apstiprinātu A. baumannii klātbūtni. Lai analizētu ar virulenci saistīto gēnu sadalījumu, tika izmantota pilna genoma sekvenēšana. Tā tika veikta Pārtikas drošības, dzīvnieku veselības un vides institūtā “BIOR”, izmantojot Nextera XT library construction kit and Illumina Miseq V3 300bp paired reads. Virulences gēnu atlasē tika izmantota virulences faktoru datu bāze (Virulence factors database). Pētījumā tika iekļauti 93 A. baumannii izolāti. 61 (66%) gadījumu bija kolonizācija, 32 (34%) gadījumi - apstiprināta infekcija. 71 virulences gēnu sadalījums tika pētīts visiem izolātiem . Visos A.baumannii izolātos bija minimums 53 gēni, bet tikai vienam izolātam tika atrasts visu analizēto 71 gēnu. 16 (17%) izolātu iztrūka gan bap, gan bauA gēnu, kas ir atbildīgi par bioplēves veidošanos un dzelzs uzņemšanu. Tika atklāts, ka 13 (15%) ir karbapenēm- rezistenti, 72 (81%) – ar kombinētu (fluorhinolonu, aminoglikozīdu un karbapenēmu) rezistenci un 4 (4%) jutīgi A. baumannii izolāti. Rezultāti atklāja, ka A.baumannii izolāti ar kombinētu rezistenci bija 81% gadījumos. Izolātos bija atklāts liels virulences gēnu īpatsvars, un starp kolonizācijas un infekcijas gadījumiem virulences gēnu profili statistiski neatšķīrās. Tomēr virulences gēnu nēsāšana A. baumannii ar kombinētu reistenci bija statistiski augstākā nekā karbapenēmu rezistentiem A. baumannii izolātiem.A. baumannii is an aerobic gram-negative bacterium that causes healthcare associated infections (HCAI). A. baumannii resistance affects the spread of health care associated infections. Molecular testing of pathogenic bacteria is an important tool for improving infection control measures against A. baumannii with combined resistance. Aim is to analyze A. baumannii infection cases, antimicrobial resistance profile and characterize molecular biological parameters according to infection type. This study was conducted in the Riga East University Hospital during 2015-2017-year period. Isolates were obtained from patients with microbiologically confirmed presence of A. baumannii. Whole genome sequencing was used for analyzing the distribution of virulence associated genes. WGS was performed in Institute of Food safety, Animal health and Environment “BIOR” using Nextera XT library construction kit and Illumina Miseq V3 300bp paired reads. VFDB was used for virulence gene selection. 93 A. baumannii isolates were included in the study. 61 (66%) cases were colonization, 32 (34%) cases - confirmed infection. We examined the distribution of 71 virulence genes in WGS of all isolates. 53 genes were present in all A. baumannii isolates while only one isolate contained all analyzed 71 gene. 16 (17%) isolates were missing both bap and bauA genes responsible for biofilm formation and iron uptake. 13 (15%) patients were found to have Carbapenem-resistant, 72 (81%) – Extensively-drug resistant (XDR) or Combined (fluoroquinolones, aminoglycosides and carbapenems) resistance and 4 (4%) sensitive A. baumannii. Results revealed that XDR isolates were accounted on 81% of cases. Isolates contained high proportion of virulence genes and there was statistically significant difference found in virulence genes profile between multi-drug resistant and carbapenem-resistant A. baumannii isolates