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Biomedical subjects

G Orefici

Publications and source records attributed to G Orefici.

103 records · Page 6Linked to original sources
PubMed1984

Group B streptococci: extracellular neuraminidase production and virulence in mouse.

Neuraminidase production by reference strains of various group B streptococci serotypes was investigated before and after serial passages in mouse. The enzyme production was tested in culture filtrates using bovine submaxillary mucin as substrate. Although passages in mouse markedly increased the virulence of all the strains it was not possible to demonstrate a relationship between the increased virulence and the enzyme production.

Animals↗
PubMed1983

Susceptibility of Mycobacterium fortuitum to antibacterial agents as evaluated by disk diffusion and agar dilution methods.

The susceptibility of 34 strains of M. fortuitum to several antimicrobial agents was comparatively tested by the disk diffusion and the agar dilution methods. The results obtained by these two methods essentially showed that the microorganism was fully sensitive to amikacin and kanamycin and only partially sensitive to sisomicin and rifampicin. Streptomycin, erythromycin and cephotaxime were inactive. The disk diffusion method seems advisable as a rapid screening procedure for antibiotic susceptibility testing M. fortuitum.

Antibiotics, Antitubercular↗
PubMed1983

Staphylococcus aureus resistant to methicillin and gentamicin as a cause of outbreak of epidemic enteritis in a hospital.

During the month of February 1982 in an orthopedic department (37 patients admitted), episodes of diarrhoea occurred in 9 patients, one of these resulting in the death of one patient. From the stool cultures of the patients methicillin/gentamicin resistant S. aureus (MRGRSA) was isolated. The clinical, microbiological and epidemiological analysis demonstrated the staphylococcal origin of the enterocolitis. The statistical analysis brought to light a significant increase in the acquisition of the infection in relation to age, surgical intervention, catheter, ulcers and antibiotic therapy. The medical staff, colonized at hand and nose by the epidemic strain contributed probably to the transmission from person to person. Antimicrobial therapy with oral vancomycin of colonized patients and application of topical ointment (betadine) on personnel eliminated colonization with methicillin/gentamicin resistant S. aureus.

Adolescent↗
PubMed1982

Study of a BCG vaccine. Influence of dose and time.

When a vaccine in three different concentrations (non-diluted, half-strength and one-third strength) was used on a study population of 159 students, six weeks after the vaccination only the vaccine at one-third strength showed small vaccination lesions in comparison with those of the other two concentrations. There is no evidence of any significant difference between them with respect to the positive reaction to the tuberculin testing. After one year, the number of subjects with a positive vaccination scar is drastically reduced in the case of the vaccine at one-third strength. As regards the tuberculin reaction, even if the difference in the number of positive values is not significant, the reaction size for the one-third and one-half strength dose diminishes significantly with respect to that observed at six weeks.

BCG Vaccine↗
PubMed1976

A study on the receptor for a mycobacteriophage : phage phlei.

From Mycobacterium phlei, glycolipid fractions have been isolated which inactivate phage Phlei. On the basis of the characteristics of the inactivation (specificity, kinetics, requirement for Ca++) typical of the phage-host cell system, it was concluded that these fractions contain the receptor sites for phage Phlei ; this conclusion was supported by electron microscopic studies. All the active fractions contain four kinds of components : fatty acids, glycerol, sugars (D-lyxose, 6-0-methyl-D-glucose, and low amounts of glucose and mannose), and water-soluble acids. These acids are isolated by degradation of the receptor fractions as oxalic and pyruvic acids. Variations of the ratio oxalic acid/pyruvic acid according to the mode of degradation and the absence of the peak characteristic of the protons of a pyruvic acid residue in the NMR spectrum, suggest that these acids might arise from the splitting of oxaloacetic acid. A tentative structure of the receptor is proposed, in many monoglycerides are linked through keto-acid to a polysaccharide core.

Binding Sites↗
PubMedDate not supplied

Rapid increase of resistance to erythromycin and clindamycin in Streptococcus pyogenes in Italy, 1993-1995. The Italian Surveillance Group for Antimicrobial Resistance.

A survey of antibiotic resistance in Streptococcus pyogenes in Italy showed a sharp increase in erythromycin resistance. In 1993, the incidence of erythromycin-resistant strains was on average 5.1%, with marked variations by geographic area. Two years later, the incidence of these strains had registered a 1.5- to roughly 20-fold increase, with a mean value of 25.9%, exceeding 40% in three centers out of 13 and 30% in another four. For all the strains studied, normal levels of susceptibility to penicillin were reported.

Anti-Bacterial Agents↗
PubMedDate not supplied

["Staphylococcus saprophyticus": a little known Staphylococcus (author's transl)].

Enzymatic patterns, antibiotic sensitivity, penicillinase, production, mercury ion resistance have been studied in St. saprophyticus strains in comparison with St. epidermidis, both isolate from urinary infections of hospital patients. The St. saprophyticus has shown to have a lower number of virulence factors, to be more sensitive to antibiotics and to have a lower potential epidemiological value.

Anti-Bacterial Agents↗