Identification of an epidemic strain ofAcinetobacter baumanii using electrophoretic typing methods

Abstract

Nosocomial infections due to Acinetobacter baumannii dramatically increased in a Lebanese medical center following an outbreak of hostilities in Lebanon in 1984. The incidence of infection caused by this organism has remained high in this institution, thus requiring the implementation of a strain typing system to aid in infection control. Three methods were investigated for their utility in differentiating among a representative group of 36 nosocomial Acinetobacter baumannii isolates obtained over a 10 month period from specimens of hospitalized patients. Isolates were typed by antibiogram analyses, plasmid fingerprinting, and total cell protein profiles. Only three distinct total cell protein profiles were detected, with one pattern accounting for 26 (72.2%) of the isolates. However, eight different plasmid profiles were observed, with 20 (55.5%) isolates having the same profile. Eleven distinct antibiograms were seen with the most prevalent pattern occurring in 21 isolates. Twenty of the 21 (95%) isolates with the common antibiogram also had the same plasmid profile and total protein profile (44.4% of total isolates). The combination of these three typing methods was useful in tracing the spread of these organisms in the medical center. The data obtained suggest the distribution of a common strain among at least six wards of this hospital.

Subtyping of Bacillus cereus by total cell protein patterns and arbitrary primer polymerase chain reaction

“…It can be postulated that probably these isolates belong to the same clone of cells bu:: different conditions lead to the expression or suppiession of one or two proteins. This observation is consistent with a study on A c i n e t o b a c t e r baumam~:ii which showed that the 3 protein patterns obtained in the typing of 36 isolates, differed from each other by only one major band [15]. We have further typed ten isolates recovered from an orange juice outbreak in USA in an attempt to assess the utility of the method in epidemiological studies.…”

“…This assay proved to be discriminatory for a variety of bacteria including H a e m o p h i l u s influenzae, Salmonella typhi and A c i n e t o b a c t e r b a u m a n i i [5,8,15]. The current study was thus undertaken to assess the subtyping potential of SDS-PAGE of total cell proteins in conjunction with AP-PCR.…”

“…Twenty-five gl of lx treatment buffer was added to all unused wells. After electrophoresis (35mA/gel, 10 °C, 3.5-5 hours), the gels were fixed and stained as previously described [15]. Total cell protein patterns were compared visually.…”

Acinetobacterin Denmark: II. Molecular studies of theAcinetobacter calcoaceticus-Acinetobacter baumanniicomplex

“…"ani-[ratus") according to the old terminology (2,9,10,18). Several authors consider A. baumannii a synonym for this old designation, enforced by the manufacturers of commercial identification systems like API (3,19,21,23,24). In the first part of the present study, 37 glucose-oxidizing (var anitratus) strains were found and of these 23 belonged to the Acb complex.…”

“…Strains of the genus Acinetobacter have been incriminated in hospital infections to an increasing extent during the last decades (3,9,15,16,21,23,25). In 1986 and 1987 Bouvet & Grimont revised the taxonomy of the genus on the basis of DNA-DNA hybridization results (4) and devised some phenotypical tests to discriminate between the DNA groups arising from the hybridization study (5).…”