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Biomedical subjects

S Barbuti

Publications and source records attributed to S Barbuti.

At least 55 records · Page 3Linked to original sources
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

[Studies on the bacteriological diagnosis of cholera and on the characteristics of isolated strains in the Apulia epidemic during the summer of 1973].

Descriptions are given of the characteristics of 107 strains of Vibrio cholerae of the serum type Ogawa isolated during the epidemic in 1973, which, although not exhibiting hemolysis in liquid culture, could be assigned because of their other characteristics to the El Tor biotype and to the phagic type 1. The Authors also make a number of technical annotations on the bacteriological diagnosis of cholera.

Bacteriophages↗
PubMedDate not supplied

[Studies on the spread of Vibrio cholerae, biotype El Tor in the environment during the period following the 1973 epidemic in Apulia].

In the period following the cholera epidemic, studies were made of sewage, seawater and various foodstuffs (green vegetables, mussels, etc.) in an attempt to isolate Vibrio cholerae of the El Tor biotype. Only in the samples of sewage taken at Bari and Taranto was it possible to isolate Vibrio cholerae biotype El Tor for a period of about a month after the last case of the illness; in this period it was isolated in 5 of the 11 samples taken at Bari and in 1 of the 14 taken at Taranto. The positive tests involved all zones of the city, leading to the conclusion that the bearers had spread throughout the whole population. The cholera-bearing vibrio was not isolated in any of the other materials, and this leads one to believe that the preventive measures taken immediately were sufficient to avoid foodstuffs being contaminated.

Cholera↗
PubMedDate not supplied

[Studies on the efficacy of cholera vaccination in a population sample of Bari].

To measure the efficacy of cholera vaccination during the epidemic of cholera occurred in August-September 1973 in Bari, agglutinating and vibriocidal antibody titers were determined in 151 subjects; of these, 65 were children between 6 months and 4 years of age and 86 adults past thirty years. Antibodies could be proved in 80% of the subjects, with relatively higher frequency in children (84,6%) than in adults (76,7%). No significant difference was seen against the serotypes Inaba and Ogawa. The vibriocidal antibody tests was uniformly more sensitive than the agglutination test. In 108 of these subjects (all of 65 children and 43 of the adults), it was possible to make the serological controls 3 and 6 months after vaccination. At 3 months, antibodies were determined in 50,7% of the children and in 44,2% of the adults; at 6 months, only 20% of the children and 18,6% of the adults showed agglutinating and vibriocidal antibodies. For the control, the research of V. cholerae-antibodies was maked also in sera of 300 healties subjects of all ages, by whom the bleedings were obtained prior to epidemic of cholera. Antibodies against the serotypes Inaba and Ogawa were determined in 23 subjects (7,6%); of these, 5 had vibriocidal titers of 1:2560-1:5120.

Adult↗
PubMedDate not supplied

Environmental surveillance of poliovirus in Italy: pilot study.

A pilot study on environmental surveillance of poliovirus included one hundred ninety-six samples (drinking water, surface water, seawater and sewage), collected between 1996 and 1998 in different regions of Italy. Samples were screened for the presence of poliovirus and other enteric viruses. Twelve polioviruses, 35 non polio enteroviruses (NPE) and 51 enteric non entero (NE) viruses were isolated. All poliovirus isolates, namely four type 1, four type 2 and four type 3, were characterised as Sabin-like strains. Thirty-one Coxsackie B and 4 Echo viruses were also detected. The presence of Sabin-like polioviruses in the environment is not unexpected since immunization with only oral poliovirus vaccine was performed in Italy until May 1999, when a sequential schedule consisting of two doses of inactivated polio vaccine (IPV) and two of oral polio vaccine (OPV) was adopted; in July 2002 a schedule consisting of four doses of IPV was adopted. Although this is only a pilot study and the number of samples analysed is limited, so far data from this study so far supports once again evidence of lack of circulating wild poliovirus and is in line with results from AFP surveillance in Italy and stool survey on healthy children.

Environmental Monitoring↗
PubMedDate not supplied

[Carriers of Neisseria meningitidis among teen-agers in Apulia (Italy)].

An investigation about N. meningitidis carriers was carried out in Apulia (Italy) among teen-agers. 85 healthy carriers were identified (1.4%): the 81.2% of isolates resulted polyagglutinable, 3.5% autoagglutinable and 1.2% were not classifiable with antisera. The other strains belonged to serogroup B (9.4%), W135 (2.3%), Y (1.2%) and 29E (1.2%). Some Authors report that non-groupable strains are usually isolated from healthy carriers pharynx. The most recent molecular methods permit to subdivide these bacteria in serotype and serosubtype by membrane protein antigens, too. So, today the only identification as serogroup is not able to study N. meningitidis epidemiology.

Adolescent↗
PubMedDate not supplied

[Legionellosis in Apulia (Italy): an underevaluated disease].

The frequent occurrence of Legionnaires' disease outbreaks in many countries, including Italy, highlights the importance of epidemiological investigations on this disease. For this purpose, an active surveillance programme of pneumonia patients was carried out in a large hospital in Apulia (Italy) from March 2001 to December 2003. A total of 612 patients were tested for Legionella pneumophila infection by urinary antigen detection and evaluation of antibodies titre. Culture of respiratory specimens was performed on 117 patients. Thirty-seven patients (6%) tested positive for legionellosis: 10 resulted nosocomial cases and 27 as community-acquired. Only 9 cases di Legionella pneumophila infection were reported from Apulia to the routine surveillance system between 1996 and 2000. The results of our study denote the level of underestimation of this disease in Apulia.

Antibodies, Bacterial↗
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↗