Genomic species diversity among 147 Acinetobacter clinical isolates not belonging to the A. calcoaceticus- A. baumannii (ACB) complex was investigated by phenotypic and genotypic identification methods. The isolates were obtained between 1991 and 1999 from numerous diagnostic laboratories in the Czech Republic and were studied by numerical probabilistic identification using two biochemical frequency matrices and amplified rDNA restriction analysis (ARDRA). Their final identification was derived from the combined phenotypic and ARDRA results. In total, 102 isolates were unambiguously (n = 89) or presumptively (n = 13) identified as A. lwoffii (n = 63), genomic species 13BJ/14TU (n = 9), A. johnsonii (n = 7), A. haemolyticus (n = 6), A. junii (n = 5), and other genomic species (n < 5 isolates each). Forty-five isolates could not be identified as belonging to any described species. Among the unidentified isolates two large groups of non-glucose-acidifying, nonhemolytic, and non-gelatinase-producing isolates were distinguished. These groups, designated phenon 1 (n = 17) and phenon 2 (n = 15), had distinctive phenotypic features and novel ARDRA profiles, which suggests that they represent hitherto undescribed Acinetobacter species. Phenon 2 included mainly clinically insignificant isolates from outpatients, while phenon 1 comprised clinically relevant isolates mostly from the blood of hospitalized patients, and its precise taxonomic definition may therefore be of medical importance. Overall, the development of practical methods for identification required for the elucidation of the biological significance of the (genomic) species within the genus Acinetobacter remains a challenging task.

National Institute of Public Health Prague Czech Republic

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Berlau J, Aucken H, Malnick H, Pit T. Distribution of Acinetobacter species on skin of healthy humans. Eur J Clin Microbiol Infect Dis. 1999;18:179–183. PubMed

Bernards A T, de Beaufort A J, Dijkshoorn L, van Boven C P A. Outbreak of Acinetobacter junii septicemia in a neonatal intensive care unit possibly caused by contaminated parenteral nutritional fluid. J Hosp Infect. 1997;35:129–140. PubMed

Bernards A T, Dijkshoorn L, van der Toorn J, Bochner B R, van Boven C P A. Phenotypic characterization of Acinetobacter strains of 13 DNA-DNA hybridization groups by means of the Biolog system. J Med Microbiol. 1995;42:113–119. PubMed

Bernards A T, van der Toorn J, van Boven C P A, Dijkshoorn L. Evaluation of the ability of the API 20NE system to identify Acinetobacter genomic species. Eur J Clin Microbiol Infect Dis. 1996;15:303–308. PubMed

Bouvet P J M, Grimont P A D. Taxonomy of the genus Acinetobacter with the recognition of Acinetobacter baumannii sp. nov., Acinetobacter haemolyticus sp. nov., Acinetobacter johnsonii sp. nov., and Acinetobacter junii sp. nov., and emended descriptions of Acinetobacter calcoaceticus and Acinetobacter lwoffii. Int J Syst Bacteriol. 1986;36:228–240.

Bouvet P J M, Grimont P A D. Identification and biotyping of clinical isolates of Acinetobacter. Ann Inst Pasteur Microbiol. 1987;138:569–578. PubMed

Bouvet P J M, Jeanjean S. Delineation of new proteolytic genomic species in the genus Acinetobacter. Res Microbiol. 1989;140:291–299. PubMed

Chu Y W, Leung C M, Houang E T S, NG K C, Leung C B, Leung H Y, Cheng A F B. Skin carriage of acinetobacters in Hong Kong. J Clin Microbiol. 1999;37:2962–2967. PubMed PMC

Cruze J A, Singer J T, Finnerty W R. Conditions for quantitative transformation in Acinetobacter calcoaceticus. Curr Microbiol. 1979;3:129–132.

Dijkshoorn L, van Harsselaar B, Tjernberg I, Bouvet P J M, Vaneechoutte M. Evaluation of amplified ribosomal DNA restriction analysis for identification of Acinetobacter genomic species. Syst Appl Microbiol. 1998;21:33–39. PubMed

Dybowski W, Franklin D A. Conditional probability and the identification of bacteria: a pilot study. J Gen Microbiol. 1968;54:215–229. PubMed

Ehrenstein B, Bernards A T, Dijkshoorn L, Gerner-Smidt P, Towner K J, Bouvet P J M, Daschner F D, Grundman H. Acinetobacter species identification using tRNA fingerprinting. J Clin Microbiol. 1996;34:2414–2420. PubMed PMC

Gerner-Smidt P. Ribotyping of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex. J Clin Microbiol. 1992;30:2680–2685. PubMed PMC

Gerner-Smidt P, Tjernberg I, Ursing J. Reliability of phenotypic tests for identification of Acinetobacter species. J Clin Microbiol. 1991;29:277–282. PubMed PMC

Grimont P A D, Bouvet P J M. Taxonomy of Acinetobacter. In: Towner K J, Bergogne-Bérézin E, Fewson C A, editors. The biology of Acinetobacter. New York, N.Y: Plenum Press; 1991. pp. 25–36.

Grundmann H J, Towner K J, Dijkshoorn L, Gerner-Smidt P, Maher M, Seifert H, Vaneechoutte M. Multicenter study using standardized protocols and reagents for evaluation of reproducibility of PCR-based fingerprinting of Acinetobacter spp. J Clin Microbiol. 1997;35:3071–3077. PubMed PMC

Horrevorts A, Bergman K, Kollée L, Breuker I, Tjernberg I, Dijkshoorn L. Clinical and epidemiological investigations of Acinetobacter genomospecies 3 in a neonatal intensive care unit. J Clin Microbiol. 1995;33:1567–1572. PubMed PMC

Ibrahim A, Gerner-Smidt P, Sjostedt A. Amplification and restriction endonuclease digestion of a large fragment of genes coding for rRNA as a rapid method for discrimination of closely related pathogenic bacteria. J Clin Microbiol. 1996;34:2894–2896. PubMed PMC

Jawad A, Snelling A M, Heritage J, Hawkey P M. Comparison of ARDRA and recA-RFLP analysis for genomic species identification of Acinetobacter spp. FEMS Microbiol Lett. 1998;165:357–362. PubMed

Juni E. Interspecies transformation of Acinetobacter: genetic evidence for ubiquitous genus. J Bacteriol. 1972;112:917–931. PubMed PMC

Juni E. Genus III. Acinetobacter Brisou and Prévot 1954, 727AL. In: Krieg N R, Holt J G, editors. Bergey's manual of systematic bacteriology. 8th ed. Baltimore, Md: The Williams & Wilkins Co.; 1984. pp. 303–307.

Lapage S P, Bascomb S, Willcox W R, Curtis M A. Identification of bacteria by computer: general aspects and perspectives. J Gen Microbiol. 1973;77:273–290. PubMed

Priest F G, Williams S T. Computer-assisted identification. In: Goodfellow M, O'Donnell A G, editors. Handbook of new bacterial systematics. London, United Kingdom: Academic Press; 1993. pp. 361–381.

Seifert H, Baginski R, Schulze A, Pulverer G. The distribution of Acinetobacter species in clinical culture materials. Zentbl Bakteriol. 1993;279:544–552. PubMed

Seifert H, Dijkshoorn L, Gerner-Smidt P, Pelzer N, Tjernberg I, Vaneechoutte M. Distribution of Acinetobacter species on human skin: comparison of phenotypic and genotypic methods. J Clin Microbiol. 1997;35:2819–2825. PubMed PMC

Tjernberg I, Ursing J. Clinical strains of Acinetobacter classified by DNA-DNA hybridization. APMIS. 1989;97:595–605. PubMed

Vaneechoutte M, Dijkshoorn L, Tjernberg I, Elaichouni A, de Vos P, Claeys G, Verschraegen G. Identification of Acinetobacter genomic species by amplified ribosomal DNA restriction analysis. J Clin Microbiol. 1995;33:11–15. PubMed PMC

Differentiation of Acinetobacter Genomic Species 13BJ/14TU from Acinetobacter haemolyticus by Use of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS)

Acinetobacter variabilis sp. nov. (formerly DNA group 15 sensu Tjernberg & Ursing), isolated from humans and animals