Molecular typing of XDR Acinetobacter baumannii strains in an Italian ICU.
OBJECTIVE
To investigate the antimicrobial susceptibility and clonal relationship of Acinetobacter baumannii strains isolated in an Italian ICU.


METHODS
Epidemiological, observational, retrospective, longitudinal study.


METHODS
The ICU of the University Hospital of Sassari, Italy.


METHODS
Pulsed Field Gel Electrophoresis (PFGE) and Multi Locus Sequence Typing (MLST) were used to evaluate the genomic features of the isolated strains.


RESULTS
Drug susceptibility testing for all isolated strains showed the same resistance pattern, characterized by resistance to the most important antibiotics, with the only exception of colistin. PFGE showed a very poor between-strain variability; three distinct clusters, 11, 4, and 1 isolates in size, were identified (Dice's coefficient: 92.11%). MLST showed that all isolated strains belonged to sequence type 2 (ST2). All isolates collected from the environment and the human samples were positive for the following genes: blaOXA-23, blaOXA-51-like, blaVIM-like, blaIMP-like, andISAba1; however, blaOXA-24-like, blaOXA-58-like, and blaNDM-like were not detected.


CONCLUSIONS
The survey identified XDR strains belonging to the same cell clone, confirming the wide circulation and environmental persistence of this microorganism.
Dip. Scienze biomediche, igiene e medicina preventiva, Università di Sassari, Italy. piana@uniss.it.|UOC Igiene, Azienda Ospedaliero Universitaria di Sassari, Italy.
Andrea
A
Piana
Dip. Scienze biomediche, igiene e medicina preventiva, Università di Sassari, Italy.|UOC Igiene, Azienda Ospedaliero Universitaria di Sassari, Italy.
Alessandra
A
Palmieri
Dip. Scienze biomediche, igiene e medicina preventiva, Università di Sassari, Italy.
Silvia
S
Deidda
Dip. Scienze biomediche, igiene e medicina preventiva, Università di Sassari, Italy.
Erica
E
Mura
UOC Igiene, Azienda Ospedaliero Universitaria di Sassari, Italy.
Bianca Maria
BM
Are
UOC Microbiologia, Azienda Ospedaliero Universitaria di Sassari, Italy.
Salvatore
S
Rubino
UOC Microbiologia, Azienda Ospedaliero Universitaria di Sassari, Italy.
Silvana
S
Sanna
Dip. Chirurgia e medicina traslazionale, Università Bicocca, Milano, Italy.
Enrico
E
Calaresu
Dip. Chirurgia e medicina traslazionale, Università Bicocca, Milano, Italy.
Clementina
C
Cocuzza
Dip. Scienze biomediche, igiene e medicina preventiva, Università di Sassari, Italy.|Ricerca, formazione medica ECM e sviluppo professionale, Azienda Ospedaliero Universitaria di Sassari, Italy.
Giovanni
G
Sotgiu
Dip. Scienze biomediche, igiene e medicina preventiva, Università di Sassari, Italy.|UOC Igiene, Azienda Ospedaliero Universitaria di Sassari, Italy.
Ida
I
Mura
D000151:Acinetobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D002648:Child; D002675:Child, Preschool; D002999:Clone Cells; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005798:Genes, Bacterial; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D012189:Retrospective Studies; D055815:Young Adult; D001618:beta-Lactamases / Q000235:genetics
D001426:Bacterial Proteins; D001618:beta-Lactamases