[ABAC, a closed system: problems and solutions, currency and perspectives]. / L'ABAC, un sistema chiuso: problemi e soluzioni, attualità e prospettive.

The ABAC System, as it is currently configured, uses pre-determined panels of antibiotics. This form of presentation is a limit for the use of the large number of new molecules, mainly active on Gram-negative bacteria. Therefore, the introduction of a new disposable, called "Gram-negative bacteria--new molecules" is suggested. Such a device will contain those additional and more widely tested antibiotics. According to recent studies concerning the pathology of Gram-positive organisms and the chemotherapeutic treatment for such pathology, changes in the disposable formulations for staphylococci and streptococci are proposed.

[Evaluation of a semiautomatic system (ABAC-ABACTOR III) for the identification of Enterobacteriaceae]. / Valutazione di un sistema semiautomatico (ABAC-ABACTOR II) per l'identificazione delle "Enterobacteriaceae".

ABAC-ABACTOR II system has been compared with two conventional methods (Enterotube II and MS-2) for the identification of Enterobacteriaceae. Our findings demonstrate the validity and the reproducibility of the identification obtained with this system.

[Evaluation of a new system for the simultaneous identification and antibiotic sensitivity testing of gram-negative bacilli by automation]. / Valutazione di un nuovo sistema per la identificazione e l'antibiogramma contemporanei di bacilli gram-negativi in automazione.

ABAC- IDENTIBIOGRAMMA II is a new system allowing the carry out of antimicrobial susceptibility testing on various bacterial groups and also the fully automatic simultaneous susceptibility testing and identification of Gram-negative bacilli (urinary and not). Particularly most species of Enterobacteriaceae and Aeromonas hydrophila, Acinetobacter sp., Pseudomonas sp. can be identified. This system has two important characteristics, due to a computerized program: that is the possibility of using sensitivity data as complement of the biochemical assays to obtain identification and the directions for use transmitted through the display. The validity of system and the reliability of its results have been verified.

[Choice of criteria in the revision of the ABAC system for the determination of sensitivity to antibiotics]. / Criteri di scelta nell'aggiornamento del sistema ABAC per la determinazione della sensibilità agli antibiotici.

The limitation of the ABAC system for the automated antibiotic sensitivity test is the fixed number of antibiotics to be assayed. This limit is partially overcome by the up-dating of ABAC disposables necessary both for bacterial infectious pathology (considerably various and dinamic) and bacterial resistance to antibiotics. Accordingly, research is constantly producing new antibiotics particularly in the beta-lactamine and aminoglycoside fields. In these groups new antibiotics must be found to substitute the old ones in the ABAC disposables, in particular in relation to Gram-negative bacteria (urinary or not). The preparation of a rotor for experimental use containing new antibiotics not present on the market is proposed to evaluate their validity through a rapid and standardized method.

[Comparison of the results of antibiotic sensitivity tests made with the ABAC method and the agar diffusion method]. / Confronto di risultati di antibiogrammi eseguiti con il metodo ABAC e con il metodo della diffusione in agar.

The sensitivity of 200 bacterial strains, recently isolated from pathological products, has been determined in relation to 16 antibiotics both with the ABAC system and the agar diffusion method (Barry). Furthermore, the interference of the variation of inoculum in the ABAC system (controlled by numbering in Petri dishes) has been evaluated. This study presented a good general agreement of the results between both methods. Results of studies on the variation of inoculum (10(6)--10(7) CFU/ml) performance with the ABAC system, gave a very weak interference in the accuracy of the results (with the exception of a few bacterial species in relation to some antibiotics).

[Evaluation of a new system for simultaneous identification and antibiograms of enterobacteria from urine]. / Valutazione di un nuovo sistema per l'identificazione e l'antibiogramma contemporanei di enterobatteri di provenienza urinaria.

A new rotor for the ABAC system has been investigated that allows the main enterobacteria of urinary source to be identified (this is performed manually) and simultaneously the relative antibiogram (this is automatically carried out). The precision of this identification has been shown using control strains previously identified by three miniaturized kits: API 20 E, MICRO-ID and ENTEROPLATE. The accuracy of the ten identification tests present in the new "Identibiogramma" rotor has also been shown. Finally, the correspondence has been shown between the antibiogram performed with the automatized method and that with the KirbyBauer method. The data obtained evidence the validity of the new rotor and of the ABAC system.