PubMed Health⌕ Search

Biomedical subjects

S Barbuti

Publications and source records attributed to S Barbuti.

11 recordsLinked to original sources
PubMed1979

Immunological and bacteriological studies in chronic pyelonephritis associated with kidney stones.

Histological and immunofluorescent techniques, urine, stone and renal fragment culture, demonstration of bacteria with fluorescent specific antisera in the renal tissue and determination of circulating antiGBM and antiTBM antibodies in the serum, were studied on the renal biopsies of 46 patients with chronic pyelonephritis (CPN) associated to kidney stones. Results show that the bacteria are often present in renal tissue of CPN with negative urine culture. The presence of C3 and C4 in some cases, and C3 and C3PA in others, at the tubular level associated with bacteria, suggest that the activation of the C system may be through the classic way, i.e., through the bacteriological immune complexes, or the alternate pathway, i.e., through the bacteria or their products. In conclusion, the evolution of the CPN may be related to the activation of the C system and the coagulation mechanism, as shown by frequent fibrinogen deposits.

Adolescent↗
PubMedDate not supplied

[Behavior of Vibrio cholerae strains of the biotype El Tor isolated in Apulia in 1973, in relation to various antibiotics and chemotherapeutics].

The tests carried out on the strains of Vibrio cholerae of the El Tor biotype, isolated during the epidemic in Apulia in 1973, brought to light the sensitivity of all the strains to various antibiotics and chemotherapeutic substances. Only one initially sensitive strain, when it was isolated again in the same patient, proved to be resistant to tetracycline. On the basis of this discovery and others communicated in published works, the Authors outline the problems posed by the emergence of antibiotic-resistant strains, especially when the resistance involves R factors.

Ampicillin↗
PubMedDate not supplied

[Research on V. cholerae anti-antibodies (agglutinating and vibriocidal) in patients affected by cholera-like gastroenteritis. Studies performed during the cholera epidemic occurred in Apulia in August-September 1973].

Agglutinating and vibriocidal antibody titers anti-V. cholerae of the serotypes Ogawa and Inaba, were determined in sera from 189 patients with cholera-like diarrheas during the epidemic of cholera occurred in August-September 1973, in Bari. Antibodies were determined in 74,2% of 70 patients, whose in the faeces and vomiting were isolated strains identified as V. cholerae, biotype El Tor, serotype Ogawa. This frequency was higher against the serotype Ogawa. The antibodies could be proved very early, 4-6 days from the beginning of symptomatology, but they disappeared as rapidly; really, at 2.3 months antibodies were determined in 7,7% only of the above mentioned subjects. As regards the other 119 patients with non-vibrio, cholera-like diarrheas, antibodies were determined in 28 subjects only; 27 of these has received cholera-vaccine some weeks before. One single case remained which was bacteriological negative, but showed signifcant agglutinating and vibriocidal antibody titers against the serotypes Ogawa and Inaba.

Agglutination Tests↗
PubMedDate not supplied

[Researches on the production of inhibitory substances by strains of "N. meningitidis" (author's transl)].

The possibility to produce some inhibitory substances has been researched in 85 strains of N. meningitidis belonging to different serogroups. By the double layer agar method, 9 of these strains have inhibited the growth of one or more indicator strains. We had the best results at 37 degrees C and 30 degrees C in tests made incubating 3 producer strains in different experiment conditions; the "Brain heart infusion agar" and the "Heart infusion agar" were the best and fittest culture media, used for the production of these substances. Several attempts to get the production of bacteriocins in liquid culture media have always given negative results, both by spontaneous growing and by ultraviolet irradiation and mitomycin induction. We were able to get 3 among these substances from as many strains of N. meningitidis (from the 85 tested) in the supernatant, only growing the strains in soft agar and centrifuging these growths. So these 3 bacteriocins had inhibited the growth of the 92% of the tested N. meningitidis, but they were inactive towards 296 bacterial strains belonging to Gram-positive and Gram-negative species (including the 15 strains of Shigella and E. coli given as indicators in the research of colicins), 70 strains of Mycoplasma and 9 L-forms of Pr. mirabilis and of St. aureus. Only 3 L-forms obtained from as many strains of N. meningitidis resulted to be inhibited by the three bacteriocins.

Bacteriocins↗
PubMedDate not supplied

[Report on Citrobacter strains having antigenic relationship with "E. coli", and their characteristics (author's transl)].

During a research done on the diffusion of enteropathogenic E. coli in a children's community, 24 strains of Citrobacter have been isolated. By agglutination and agar-gel diffusion techniques, they looked to have some somatic antigens in common with those serogroups of enteropathogenic E. coli. The results were as follows: 14 strains were correlated with the serogroup O111; 9 strains with the serogroup O125 and 1 strain with the serogroup O55. The isolation of these strains has been made at the same period when we have found out the E. coli of homologous serogroups, even if they didn't belong to the same subjects. The colicine typing and sensibility to antibiotics tests made both on Citrobacter strains and on E. coli ones of homologous serogroups haven't pointed out other characteristics of identity. Furthermore, antigenic relationships between the 24 strains of Citrobacter and different serogroups of Salmonella have been demonstrated, that is: the strains containing the somatic antigen O111 were correlated with the serogroup O35; the strains having the somatic antigen O125, with the serogroup O6, 14, 24 and the strain containing the somatic antigen O55, with the serogroup O50. The presence of these strains in normal subjects only, gives a further witness that their role in enteric infections remains to be demonstrated.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Researches on some biochemical and serological properties and on the sensitivity to antibiotics of L-forms of "Proteus" (author's transl)].

The possibility to keep some biochemical reactions of the parent strains (urease-positive, glucose fermentation, phenylalanine-deaminase-positive, H2S but not indol production) was demonstrated in 5 L-forms, obtained from as many strains of Pr. mirabilis and in 1 L-form, isolated from a vaginal secretion and identified as belonging to the same species. The indirect hemagglutination technique, made by the sonicated antigen in 3 of the 6 L-forms with Proteus OXK antiserum, resulted positive in titers varying from 1:128 to 1:1024. Crossed tests made with antisera for different bacterial species (e. coli, Shigella, klebsiella, ecc.) and of Mycoplasma (M. hominis, M. orale, M. salivarium, M. fermentans, M. arthritidis) put in evidence aspecific reactions only in 1.3% of the bacterial antisera. On the contrary, all 5 antisera for Mycoplasma were able to agglutinate the sensitized erythrocytes at titers quite analogous to that of the homologous antiserum. The sensitivities to various antibiotics of the 6 L-forms and the parent strains has been determined. All of L-forms were more resistent to the tetracycline than L-forms of other bacterial species. On the basis of te results got by biochemical and serological tests, we confirm the necessity to make use of both the groups of tests, in order to identify the L-forms of recent isolation.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Researches on some properties of inhibitory substances produced by strains of "N. meningitidis" (author's transl)].

Some properties of three inhibitory substances produced by as many strains of N. meningitidis have been studied. All these substances appeared to be completely destroyed by proteolytic enzymes (trypsin and pronase) and to be very heat-stable; they were insensitive to ultraviolet light and they were stable pH 2-10; filtration through filters of different porosity (Seitz, Berkefeld, millipore membranes) resulted in loss of the inhibitory effect constantly. On the basis of these results and on their specific action specific action, it is possible to class these substances among bacteriocins ("meningocins") at low molecular weight.

Bacteriocins↗
PubMedDate not supplied

[Further research of antibodies anti-"N. meningitidis" among healthy population of Bari (southern Italy) (author's transl)].

Research of antibodies anti-N. meningitidis serogroups A, B, and C was carried out on 248 healthy children 7 months-10 years aged by indirect hemagglutination, to determine the age of their initial demonstration into the serum and the time of their clearness, besides the diffusion of antibodies within the infantile population. Antibodies against one or more serogroups of N. meningitidis were detected already in the second half-year life in 73 percent examined children. Frequence of antibodies is progressively increasing in the last years until to findings about 90-100%. Antibodies against N. meningitidis serogroups A were detected more frequently, and in a less degree, the ones against serogroup C. Research of antibodies after 2 and 12 months was repeated on 84 subjects; for the most part of these the antibody titre was the same.

Age Factors↗
PubMedDate not supplied

[Studies of some biochemical characteristics and antibiotic sensitivity of 30 L strains of Staphylococcus aureus].

The production of coagulase, DNase and haemolysins by 30 L-forms obtained from as many strains of Staphylococcus aureus having these properties, has been studied using different techniques. All of L-strains produced coagulase, for the most part after incubation for 24 h, but only some produced DNase and haemolisins. At the same time, the sensitivities of various antibiotics of staphyloccal L-forms and the parent strains has been determined. All of L-forms, as regards to bacterial form from which they were derived, showed an high resistance to antibiotics of which the primary site of action is upon cell wall (penicillin, ampicillin, methicillin, cephalosporins, vancomycin), with the exception of bacitracin. The tetracycline was more effective against the L-forms, while the group that includes chloramphenicol, novobiocin, streptomycin, gentamycin and kanamycin inhibited coccal and L-forms about equally.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Studies of the enterotoxin production capacity of L forms derived from enterotoxic strains of Staphylococcus aureus].

The production of enterotoxin by L-forms obtained from strains of Staphylococcus aureus (10 enterotoxin A-producing strains, 7 enterotoxin B, 2 enterotoxin C and 1 which produced both enterotoxins A and C) has been studied by agar-gel diffusion technique. Using a proper technique, enterotoxin could be detected for 4 L-forms; 3 of these produced the same enterotoxin as parent strain (2 enterotoxin A and 1 enterotoxin B). As regards the other L-form, obtained from strain of St. Aureus which produced both enterotoxins A and C, only enterotoxin A could be detected.

Enterotoxins↗