HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (Papers in Press[PDF]) All Versions of this Article: mic.0.026054-0v1 155/7/2333    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Gundi, V. A. K. B. Articles by La Scola, B. Search for Related Content PubMed PubMed Citation Articles by Gundi, V. A. K. B. Articles by La Scola, B. Agricola Articles by Gundi, V. A. K. B. Articles by La Scola, B.

Validation of partial rpoB gene sequence analysis for the identification of clinically important and emerging Acinetobacter species

¹ Universite de la Mediterrannee;
² Leiden University Medical Center;
³ Faculte de Medecine de Marseille, Universite de la Mediterranee

ABSTRACT

Bacteria belonging to the genus Acinetobacter are ubiquitous in soil and water. Only a few species including Acinetobacter baumannii, and the unnamed Acinetobacter genomic species (gen. sp.) 3 and 13TU which together with the soil organism Acinetobacter calcoaceticus are combined in the A. calcoaceticus-A.baumannii (Acb-) complex have been recognized as important nosocomial infectious agents. The ecology, epidemiology and pathology of most species are not yet well-established. Lack of practical and accurate methods limits routine identification of clinical isolates and thus hampers precise identification of those of the Acb-complex and other Acinetobacter species of possible clinical significance. We previously identified a 350-bp highly variable zone on the rpoB gene which appeared a promising target for rapid molecular identification [La Scola et al., Journal of Clinical Microbiology (2006) 44: 827-832]. In the present study, we validated this method for accuracy on a collection of reference strains belonging to A. calcoaceticus (5 strains), Acinetobacter gen. sp. 3 (29 strains), gen. sp. 13TU (18 strains), A. baumannii (30 strains) and one strain each of A. radioresistens, A. gen. sp. 15TU, A. gen. sp. 10, A. gen. sp. 11, A. gen. sp. "between" 1-3 and A. gen. sp. 14TU=13BJ. This represent the largest analysis to date that compares a large number of well-identified strains of the Acb-complex to assess the intra- and interspecies variation within this complex. All were correctly identified with 98.9-100% intra-species relatedness based on partial rpoB sequence analysis. We then applied this tool to identify 99 Acinetobacter clinical isolates from 4 public hospitals in Marseille, France. All isolates could easily be identified to species as they were separated into 13 species sequence types (SSTs) with a sequence variance of 0-2.6% with their respective type strains. Of these 99 isolates, 10 were A. haemolyticus, 52 were A. baumannii, 27 were A. gen. sp. 3, 5 were A. schindleri, 1 was A. lwoffii, 1 was A. gen. sp. 13TU. Three were provisionally identified as A. gen. sp. 9. This is the first work in identifying all specimens of a set of clinical Acinetobacter isolates at species level using rpoB sequence analysis. Our data emphasize the recognition of A. schindleri as an emerging cause of Acinetobacter-related infection and confirm that A. gen. sp. 3 is the second most commonly isolated Acinetobacter species after A. baumannii in patients.

⁴ E-mail: bernard.lascola{at}medecine.univ-mrs.fr