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G M Rossolini

Publications and source records attributed to G M Rossolini.

97 records · Page 6Linked to original sources
PubMedDate not supplied

Bacterial acid phosphatase gene fusions useful as targets for cloning-dependent insertional inactivation.

The Morganella morganii phoC gene, encoding a class A acid phosphatase, was used to generate gene fusions with modified amino-terminal moieties of the Escherichia coli lacZ gene carrying a multiple-cloning site flanked by phage-specific promoters and recognition sites for universal sequencing primers. The corresponding hybrid proteins retained a PhoC-like enzymatic activity which is easily detectable by a plate histochemical assay, rendering similar gene fusions potentially useful as targets for cloning-dependent insertional inactivation. Cloning experiments performed in plasmids carrying similar lacZ-phoC fusions confirmed their usefulness as cloning vectors for direct screening of recombinants. As compared to conventional lacZ alpha-complementation-based vectors, which can only be used in E. coli hosts carrying specific lacZ mutations, the lacZ-phoC fusion-based vectors can be used in combination with any E. coli host and require a less expensive histochemical assay for screening of recombinants, while retaining all the advantageous features that made the former so popular as general purpose cloning vehicles.

Acid Phosphatase↗
PubMedDate not supplied

Interaction of cefotetan and the metallo-beta-lactamases produced in Aeromonas spp. and in vitro activity.

Aeromonas spp. are increasingly being recognized as human pathogens. The presence of metallo-beta-lactamases in these organisms represents a potential problem in antimicrobial therapy. Mechanism-based inactivators of beta-lactamases are used to overcome the resistance of clinical pathogens to beta-lactam antibiotics, but no clinical useful inhibitors of the metallo-beta-lactamases are presently known. Studying the interaction between cefotetan and Aeromonas spp. producing metallo-beta-lactamase activity, we observed that cefotetan behaved as a transient inactivator for both the crude extracts of Aeromonas strains and the purified enzymes from Aeromonas hydrophila AE036 and Aeromonas schubertii MNSA20. The direct hydrolysis of cefotetan showed that it was a poor substrate for both purified enzymes. In view of the minimum inhibitory concentrations, cefotetan shows to be a useful antimicrobial agent against Aeromonas spp.

Aeromonas↗
PubMedDate not supplied

Identification of Aeromonas strains of clinical origin with atypical phenotypical profiles.

A total of 47 strains of Aereomonas isolated from patients with gastroenteritis was analyzed for 40 phenotypical characters and for evaluating the numeric taxonomy based on 27 discriminatory tests. It was proved that the clinical isolates showed a relative phenotypical distance and the groups of strains that had atypical profiles were compared with the type species by the present identification schemes.

Aeromonas↗
PubMedDate not supplied

Development of immunoglobulin M-antibodies after rubella immunization with RA27/3 attenuated live vaccine in teen-agers: remaining problems.

Four-hundred-fourty-two rubella seronegative teen-agers living in Siena and the surroundings were vaccinated with RA 27/3 live attenuated rubella over a two years period (1985-1987). One-hundred-twenty seven vaccinees' sera were randomly selected for the rubella specific antibodies of the IgM class detection with two Elisa Methods; the sera were collected 10 and 30 days after the challenge; in 58 girls a serum sample was also obtained 1 yr later. None of the sera showed reactivity for RF. The comparison between the two Elisa methods gave satisfactory results, the percentage of discrepancies being low (3.9%). Ten days after the immunization the IgM positive sera were only 7.56% (Elisa Abbott) and 5.88% (Elisa Enzygnost Behringwerke). One month later, 86.61% of the specimens showed reactivity for specific IgM antibodies. None of 58 sera gave positive results after 1 yr. Rubella antibodies of the IgG class could be demonstrated in the "screening" sera of 3 IgM negative subjects, when an Elisa method was applied. Nine subjects (7%) repeatedly resulted IgM negative one month after the challenge although a seroconversion was observed using both HAI and EIA. A serum sample was also obtained in 6/9 IgM "non responders" after a rubella epidemic observed in 1988-1989; no subclinical reinfection due to the wild virus was detected in this group, no changes in HAI antibody title nor evidence of IgM class specific response were observed. Although most of the diagnostic aspects related with rubella and rubella vaccination appear to be resolved, it should be underlined that there are several remaining problems especially associated with IgM detection.

Adolescent↗
PubMedDate not supplied

[Evaluation of the specific immune response after anti-rubella vaccination].

A selective rubella immunization program was carried out in the Siena (Italy) area since 1984. 912 schoolgirls aged 10 to 18 were screened for rubella antibodies. Seropositivity rates, increasing with age, appeared quite heterogenous among subjects living in different villages. Seronegative girls were partly voluntarily immunized with RA 27/3 live attenuated rubella vaccine. Serological and clinical controls performed on 238 subjects one month after immunization showed a 99.6% vaccine-induced seroconversion rate and mild post-vaccinal reactions in 26% of vaccinees. Serological control performed, on 172 subjects, at 8-12 days after vaccination revealed that in most cases vaccine induced haemagglutination-inhibiting antibodies are not detectable at the time. The results are discussed in relation to a forthcoming introduction of compulsory rubella vaccination in our Country.

Adolescent↗