Acinetobacter baumannii in intensive care unit: a novel system to study clonal relationship among the isolates.
BACKGROUND
The nosocomial infections surveillance system must be strongly effective especially in highly critic areas, such as Intensive Care Units (ICU). These areas are frequently an epidemiological epicentre for transmission of multi-resistant pathogens, like Acinetobacter baumannii. As an epidemic outbreak occurs it is very important to confirm or exclude the genetic relationship among the isolates in a short time. There are several molecular typing systems used with this aim. The Repetitive sequence-based PCR (REP-PCR) has been recognized as an effective method and it was recently adapted to an automated format known as the DiversiLab system.


METHODS
In the present study we have evaluated the combination of a newly introduced software package for the control of hospital infection (VIGI@ct) with the DiversiLab system. In order to evaluate the reliability of the DiversiLab its results were also compared with those obtained using f-AFLP.


RESULTS
The combination of VIGI@ct and DiversiLab enabled an earlier identification of an A. baumannii epidemic cluster, through the confirmation of the genetic relationship among the isolates. This cluster regards 56 multi-drug-resistant A. baumannii isolates from several specimens collected from 13 different patients admitted to the ICU in a ten month period. The A. baumannii isolates were clonally related being their similarity included between 97 and 100%. The results of the DiversiLab were confirmed by f-AFLP analysis.


CONCLUSIONS
The early identification of the outbreak has led to the prompt application of operative procedures and precautions to avoid the spread of pathogen. To date, 6 months after the last A. baumannii isolate, no other related case has been identified.
Fontana
Carla
C
Department of Experimental Medicine and Biochemical Sciences, Tor Vergata University of Rome, Via Montpellier 1, 00133 Rome, Italy. carla.fontana@uniroma2.it
Favaro
Marco
M
Minelli
Silvia
S
Bossa
Maria Cristina
MC
Testore
Gian Piero
GP
Leonardis
Francesca
F
Natoli
Silvia
S
Favalli
Cartesio
C
D000151:Acinetobacter Infections / Q000382:microbiology / Q000517:prevention & control* / Q000635:transmission; D040981:Acinetobacter baumannii / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D054458:Amplified Fragment Length Polymorphism Analysis; D002984:Clinical Laboratory Information Systems / Q000295:instrumentation; D002999:Clone Cells; D003428:Cross Infection / Q000517:prevention & control* / Q000635:transmission; D016172:DNA Fingerprinting; D004196:Disease Outbreaks / Q000517:prevention & control; D004783:Environmental Microbiology; D005260:Female; D006801:Humans; D017053:Infection Control / Q000295:instrumentation / Q000379:methods*; D007362:Intensive Care Units; D007558:Italy; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000295:instrumentation / Q000379:methods*; D018571:Sentinel Surveillance; D012984:Software