Article

Acinetobacter baumannii in intensive care unit: a novel system to study clonal relationship among the isolates.

Department of Experimental Medicine and Biochemical Sciences, Tor Vergata University of Rome, Via Montpellier 1, 00133 Rome, Italy.
BMC Infectious Diseases (Impact Factor: 3.03). 02/2008; 8:79. DOI: 10.1186/1471-2334-8-79
Source: PubMed

ABSTRACT 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.
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.
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.
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.

0 Bookmarks
 · 
123 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVES: To establish the possible sources and routes of transmission of a multidrug-resistant Acinetobacter baumannii outbreak involving 22 patients. STUDY DESIGN: Descriptive, retrospective study. METHODS: An environmental investigation was undertaken, monitoring surfaces, air and water. Reconstruction of the spread of the infection took several factors into account such as intrahospital movements of patients and healthcare personnel, hospitalization of patients in the same ward and in chronologically compatible periods, and length of stay. A. baumannii clinical samples were typed using the Multilocus Sequence Typing scheme. RESULTS: The outbreak originated from a patient admitted to the sub-intensive care unit, and the infection subsequently spread to other wards. The allelic profile proved to be the same for all the clinical isolates. Environmental monitoring yielded negative results for A. baumannii. CONCLUSIONS: The results suggest that this epidemic spread through cross-transmission involving healthcare workers.
    Public health 03/2013; · 1.26 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the antibiotic resistance genes inserted into class 1 and class 2 integrons in Acinetobacter baumannii (A. baumannii) isolates obtained from nine different cities in Turkey. A collection of 281 A. baumannii clinical isolates were collected from nine diferent state hospitals in Turkey and were confirmed as A. baumannii by conventional biochemical, API testing and bla -OXA-51 specific PCR. The isolates were examined by PCR for existence of class 1 and 2 integron gene cassettes. They were characterized by antimicrobial susceptibility testing and the highest resistance rates were determined for piperacillin (90.03%), ciprofloxacin (87.54%), cefepime and trimethoprim/sulfamethoxazole (81.13%). The lowest resistance rates was for cefotaxime (3.55%). class I integrons were detected in 6.4% (18/281) of A. baumannii strains and no class 2 integron was detected. The gene cassettes of class 1 integrons AacC1-AAC(3)I-aadA1, AacC1-aadA1, AAC(3)-I, AAC(3)-I -AAC(3)-I -aadA1, TEM-1, AAC(3)-I-aadA1 - AAC(3)-I -AAC(3)-I, AAC(3)-I -AAC(3)-I -AAC(3)-I -aadA1, AAC(3)-I - aadA1, AAC(3)-I-AAC(3)-I, AAC(3)-I-aadA1- AAC(3)-I-aadA1, AAC(3)-I- AAC(3)-I- aadA1-AAC(3)-I-aadA1 were detected in eighteen strains. The aac genes family were most frequently found integrated into the class 1 integrons and it was followed by aadA genes and TEM-1 genes. This is an extensive study on the distribution of class 1 integron among A. baumannii in Turkey. In addition to these, two new alleles were observed. Their percentage rates of similarity to other cassettes are 95% aadA1 ( TKA18) and 89% aadA1 (ANKA3).
    Asian Pacific Journal of Tropical Biomedicine 09/2013; 3(9):743-7.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Multidrug-resistant Acinetobacter baumannii (MDRAB) is an increasing problem worldwide. Prevalence of carbapenem resistance in Acinetobacter spp. due to acquired carbapenemase genes is not known in Finland. The purpose of this study was to examine prevalence and clonal spread of multiresistant A. baumannii group species, and their carbapenemase genes. A total of 55 Acinetobacter isolates were evaluated with repetitive PCR (DiversiLab) to analyse clonality of isolates, in conjunction with antimicrobial susceptibility profile for ampicillin/sulbactam, colistin, imipenem, meropenem, rifampicin and tigecycline. In addition, a new real-time PCR assay, detecting most clinically important carbapenemase genes just in two multiplex reactions, was developed. The assay detects genes for KPC, VIM, IMP, GES-1/-10, OXA-48, NDM, GIM-1, SPM-1, IMI/NMC-A, SME, CMY-10, SFC-1, SIM-1, OXA-23-like, OXA-24/40-like, OXA-58 and ISAbaI-OXA-51-like junction, and allows confident detection of isolates harbouring acquired carbapenemase genes. There was a time-dependent, clonal spread of multiresistant A. baumannii strongly correlating with carbapenamase gene profile, at least in this geographically restricted study material. The new carbapenemase screening assay was able to detect all the genes correctly suggesting it might be suitable for epidemiologic screening purposes in clinical laboratories.
    PLoS ONE 01/2014; 9(1):e85854. · 3.73 Impact Factor

Full-text (2 Sources)

View
37 Downloads
Available from
Jun 10, 2014