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Biomedical subjects

W Baffone

Publications and source records attributed to W Baffone.

At least 19 recordsLinked to original sources
PubMed2006

Microbiological study of cosmetic products during their use by consumers: health risk and efficacy of preservative systems.

AIM: To evaluate the microbial contamination of 91 cosmetics (23 o/w emulsions, 47 tensiolytes, 21 aqueous pastes) in three different states of use (intact, in-use, ending product) and the protection efficacy of the preservative systems most frequently used in the analysed cosmetic formulations. METHODS AND RESULTS: Total bacterial count, isolation and identification of pathogenic isolates were performed on the collected cosmetics. About 10.6% of tensiolytes (13.5% bath foam, 6.7% shampoo, 10% liquid soaps) were contaminated by Staphylococcus warneri, Staphylococcus epidermidis and Pseudomonas putida. The efficacy of the preservative systems of two cosmetic products, tested against standard micro-organisms (Staphylococcus aureus ATCC 4338 and Pseudomonas aeruginosa ATCC 9027) and two isolates from cosmetics in this study (S. epidermidis and P. putida), satisfied the Cosmetics, Toiletries, and Fragrance Association and Official Italian Pharmacopeia criteria, while only one tested cosmetic respected the Rapid Challenge Test criterion. CONCLUSIONS: Contaminated cosmetic products are relatively uncommon, but some products, unable to suppress the growth of several micro-organisms, represent a potential health hazard. SIGNIFICANCE AND IMPACT OF THE STUDY: The challenge test may be performed not only during the preparation of the preservative system in the intact cosmetics, but also be used to evaluate the protection efficacy during their use.

Bacteria↗
PubMed2005

Flow cytometric evaluation of Vibrio parahaemolyticus adhesion inhibition to human epithelial cells.

BACKGROUND: The present report demonstrates the usefulness of flow cytometry for a quantitative assessment of adhesion inhibition of a Vibrio parahaemolyticus strain to human epithelial cells to acquire more information about the nature of its adhesins. METHODS: The inhibition of the adhesive process to Hep-2 was assayed by adding several monosaccharides to infected cells monolayers. The quantification of the adherent bacteria, labeled with a specific primary antibody plus a secondary fluorescein isothiocyanate-conjugated antibody, was performed by flow cytometry in comparison with light microscopy. The adherence was quantified in terms of the proportion of cells with adherent V. parahaemolyticus and as the mean of adherent bacteria per cell. RESULTS: The adhesion showed a percentage of 98% with a mean fluorescence channel of 331 comparable to those obtained by light microscopy. The addition of monosaccharides resulted in a D-mannose and N-acetyl-galactosamine sensitive adherence. Even if this environmental strain also showed a mannose-sensitive cell-associated hemoagglutination that could mediate V. parahaemolyticus adherence, our results suggest that different sites for an irreversible adherence to host cell are involved. CONCLUSIONS: Flow cytometry in combination with indirect immunofluorescence is an effective tool to investigate the adhesive process of bacteria to epithelial cells because it is more sensitive and reproducible than visual counting of bacteria performed in light microscopy.

Animals↗
PubMed2004

Morphological changes and outer membrane protein patterns in Helicobacter pylori during conversion from bacillary to coccoid form.

Conversion from bacillary to fully coccoid form via an intermediate U-and V-shaped form has been described in prolonged cultures of H. pylori. This morphological transformation may be the expression of transitory adaptation to a particular environment and may play an important role in antibiotic resistance and the difficulty to eradicate the pathogen. The aim of this study was to evaluate morphological and outer membrane protein changes in H. pylori during ageing-induced conversion to coccoid morphology. We used two H. pylori strains (the reference NCTC 11639 and a fresh clinical isolate) cultivated in microaerophilic environment at 37 degrees C, monitoring their morphological and biochemical evolutions for 11 days. Microscopic examination revealed the passage from spiral to U- and V-shaped form after 5-8 days of incubation, the conversion to coccoid form and the entry into viable but non-culturable state (VBNC) between days 9 and 11. Protein pattern difference appeared at 97.4 to 45 and 30 kDa molecular weight. Biochemical tests demonstrated not only a modification of outer membrane protein profiles, but also an intra-specific variability by comparison between the two analysed strains. Our findings suggest that structural and outer membrane changes associated with coccoid transformation represent a typical response in H. pylori and may constitute a survival strategy in adverse environmental conditions.

Adaptation, Physiological↗
PubMed2003

Retention of virulence in viable but non-culturable halophilic Vibrio spp.

The viable but non-culturable (VBNC) forms of two environmental strains of Vibrio alginolyticus 1 and Vibrio parahaemolyticus 66 and one strain of V. parahaemolyticus ATCC 43996 showing virulence characteristics (hemolysin production, adhesive and/or cytotoxic ability, in vivo enteropathogenicity) were obtained by culturing bacteria in a microcosm consisting of artificial sea water (ASW) and incubating at 5 degrees C with shaking. Every 2 days, culturability of the cells in the microcosm was monitored by spread plates on BHI agar and total count and the percentage of viable cells were determined by double staining with DAPI and CTC. When cell growth was not detectable (<0.1 CFU/ml), the population was considered non-culturable and, then, the VBNC forms were resuscitated in a murine model. For each strain, eight male Balb/C mice were intragastrically inoculated with 0.1 ml of concentrated ASW bacterial culture. Two mice from each group were sacrificed at 2, 4, 8, and 12 days after challenge for autopsy and re-isolation of the microorganisms from the intestinal tissue cultures. Isolation was obtained in 25% of the animals challenged with the VBNC V. alginolyticus strain, in 37.5% of those challenged with the VBNC V. parahaemolyticus strain of environmental origin and in 50% of the animals infected with VBNC V. parahaemolyticus ATCC 43996. The strains thus isolated were again subjected to biological assays to determine the retention of pathogenicity. The virulence characteristics that seemed to disappear after resuscitation in the mouse were subsequently reactivated by means of two consecutive passages of the strains in the rat ileal loop model. The results obtained indicate that VBNC forms of the strains examined can be resuscitated and retain their virulence properties.

Animals↗
PubMed2002

Synthesis of new C-6 alkyliden penicillin derivatives as beta-lactamase inhibitors.

New penicillin, penicillin sulfone and sulfoxide derivatives bearing a C-6-alkyliden substituent were prepared. Their chemical synthesis, in vitro antibacterial activity and inhibition properties against two selected enzymes representing Class A and C beta-lactamases are reported. Compounds 3a-c, 7a-c were able to inhibit either TEM-1 (a Class A enzyme, from Escherichia coli) or P-99 (a Class C enzyme, from E. cloacae), or both enzymes, when tested in competition experiments using nitrocefin as the reporter substrate. However, when tested in combination with amoxicillin, the same compounds did not show synergistic effects against E. coli and E. cloacae strains producing TEM-1 and P99 enzymes, respectively. This finding is most likely related to poor penetration through the bacterial cell wall, as shown by using a more permeable isogenic E. coli strain. Interestingly, a synergistic effect against a strain of S. aureus which produces PC1-enzyme (a Class A beta-lactamase) was observed for compound 3a when used in combination with amoxicillin.

Amoxicillin↗
PubMed2001

Detection of Escherichia coli O157:H7 and other intestinal pathogens in patients with diarrhoeal disease.

Six hundred and six faeces specimens from patients with diarrhoea, aged 0->60 and living in the area of Fano (Italy), were examined for Escherichia coli O157:H7, Salmonella, Shigella and thermophilic Campylobacter spp. E. coli O157:H7 was not found, confirming the limited circulation of this bacterium in our country. On the other hand, Salmonellae were the most frequent pathogens (5.6%), followed by Campylobacters (2.3%) and Shigellae (0.3%).

Adolescent↗
PubMed2001

Possible involvement of Pseudomonas fluorescens and Bacillaceae in structural modifications of Tuber borchii fruit bodies.

Previous studies on Tuber borchii fruit bodies in early maturation stages suggested a role of bacteria in sporocarp structural modifications. In order to verify this hypothesis, in the present study we investigated by means of microbial and ultrastructural approaches, the bacterial population of T. borchii sporocarps from intermediate maturation phases to advanced decomposition stages, paying particular attention to chitinolytic and cellulolytic bacteria and to their relationships with ascii and ascospores. We found that Pseudomonas fluorescens and spore-forming Bacillaceae, both able to degrade cellulose and chitin, are present inside the sporocarps in all maturation stages investigated. Moreover, rod-shaped bacteria seem able to erode ascus walls and colonize the interior of ascii containing mature spores. These results suggest a possible role of these bacteria in the process of ascus opening. Moreover, the presence of P. fluorescens and Bacillaceae on isolated mature spores after decontamination suggests an intimate association between these bacteria and the ascospores.

Ascomycota↗
PubMed2001

Studies on the development and stability of resistance of Helicobacter pylori to metronidazole and clarithromycin.

Thirty-one strains of Helicobacter pylori, susceptible to metronidazole and clarithromycin, were isolated from 31 biopsy samples from patients with various gastric pathologies. We investigated the possibility of selecting resistant strains and the stability of resistance by exposing isolates to increasing subinhibitory concentrations of metronidazole and clarithromycin using a serial passages technique. Resistance to metronidazole was obtained in 100% of the isolates, while 32.2% displayed resistance to clarithromycin. Resistance to metronidazole was stable in 93.5% (29 of 31) of the isolates, whereas 100% (10 of 10) of the strains were stably resistant to clarithromycin. The stability of the resistance that occurred after three passages on medium containing the two drugs was statistically significant (P <0.001). Thus, the technique of serial passages in vitro could be useful as a first screening in selecting drugs for use in therapeutic protocols for clinical trials.

Anti-Bacterial Agents↗
PubMed2000

Occurrence and expression of virulence-related properties of Vibrio species isolated from widely consumed seafood products.

In this study, widely consumed fresh seafood products were examined for the presence of Vibrio spp. Thirteen percent of the samples examined were found to be contaminated with halophilic vibrios belonging to the species V. alginolyticus (81.48%), V. parahaemolyticus (14.8%) and V. cholerae non 0:1 (3.7%). A greater isolation frequency (18.9%) was found for mussels. Significant adhesiveness and strong cytotoxicity factors were revealed in a significant number of the Vibrio spp. isolated. These results confirm that the presence of Vibrio spp. in seafood products is common, and suggest that routine examination of such products for these pathogenic agents would be advisable.

Adhesins, Bacterial↗
PubMed2000

Presence of enteroviruses and reoviruses in the waters of the Italian coast of the Adriatic Sea.

EEC directive 76/160 requires member states to apply microbiological and chemico-physical standards for the quality of recreational waters. In observation of this regulation, in the present study 144 samples of seawater were taken over a 12-month period and tested to determine viral contamination. The samples were collected from the coastal waters of the Italian town of Pesaro, which is located on the Adriatic Sea. Using cell culture techniques, 32.6% of the seawater samples were found to be contaminated with enteroviruses. Isolation of these viruses was most frequent in the summer months. Thus, our results indicate the need to increase the frequency of monitoring of these waters and to eliminate the sources of contamination.

Cell Culture Techniques↗
PubMed1999

Occurrence, diversity, and pathogenicity of halophilic Vibrio spp. and non-O1 Vibrio cholerae from estuarine waters along the Italian Adriatic coast.

The occurrence, diversity, and pathogenicity of Vibrio spp. were investigated in two estuaries along the Italian Adriatic coast. Vibrio alginolyticus was the predominant species, followed by Vibrio parahaemolyticus, non-O1 Vibrio cholerae, and Vibrio vulnificus. By using a biochemical fingerprinting method, all isolates were grouped into nine phenotypes with similarity levels of 75 to 97.5%. The production of toxins capable of causing cytoskeleton-dependent changes was detected in a large number of Vibrio strains. These findings indicate a significant presence of potentially pathogenic Vibrio strains along the Adriatic coast.

Animals↗
PubMed1998

Occurrence, diversity and pathogenicity of mesophilic Aeromonas in estuarine waters of the Italian coast of the Adriatic Sea.

A total of 208 strains of Aeromonas were isolated by monthly sampling from two estuaries (one provided with, and the other devoid of a waste-water treatment system) on the Italian coast of the Adriatic sea between September 1994 and August 1995. Biotyping at the species level allowed the identification of 96 strains (46%) as Aer. caviae, 46 (22%) as Aer. sobria, 33 (16%) as Aer. hydrophila and 25 (12%) as Aer. veronii. Eight strains (4%) were regarded as unnamed aeromonads. Aeromonas caviae was the most prevalent species in water with a high degree of pollution, while Aer. hydrophila strains were more commonly isolated from cleaner water. Aeromonas sobria and Aer. veronii were equally distributed in both estuaries. There was no correlation between temperature and numbers of aeromonads in either estuary. Using a biochemical fingerprinting method, strains were divided into similarity groups (PhP-types) based on their biochemical phenotypes. Several different PhP-types were found in each estuary, yielding a high diversity for these strains. However, some identical PhP-types were also found in both estuaries and at different times of the year, indicating that certain Aeromonas strains can survive more widely varying physico-chemical conditions. The production of toxins capable of causing cytoskeletal-dependent changes in the morphology of Chinese hamster ovary (CHO) cells was detected in 14 strains and appeared to be dependent on the season.

Aeromonas↗
PubMed1997

Antipoliomyelitis immunity status in a cohort of young men drafted into military service, residing in the suburban Milan area.

The aim of this study was to verify the antipolio immune status of a cohort of eighteen year-olds residing in the suburban Milan area for whom vaccination histories were available. Seropositivity (titres of neutralizing antibodies > or = 1:8) for the three virus serotypes was detected in 89.2% of the 530 subjects tested, whereas simultaneous seronegativity for all three polioviruses was found for only 0.6% of the subjects.

Adolescent↗
PubMed1997

Comparison of colloidal bismuth subcitrate and metronidazole, both in combination with an H2-antagonist as therapy for Helicobacter pylori.

In this random study, the efficacy of either colloidal bismuth subcitrate (CBS) or metronidazole in combination with an H2-antagonist in the treatment of various gastric pathologies was evaluated, along with the trends in antibody levels. Among the 40 Helicobacter pylori-positive patients with various gastroduodenal pathologies who underwent chemotherapy, 27 were treated with CBS and 13 with metronidazole. H. pylori was eradicated in 48.14% of the patients treated with CBS and 53.8% of those treated with metronidazole. After therapy, no statistically significant or slight decrease in the serum levels of antibodies was found.

Adult↗
PubMed1995

Diffusion of thermophilic Campylobacter in the Pesaro-Urbino area (Italy) from 1985 to 1992.

The results of research on the spreading of campylobacter in the Pesaro-Urbino area carried out from 1985 to 1992 are presented. Materials of different origin were examined: 822 samples of human faeces, 533 animal rectal swabs, 192 samples of domestic sewage, 48 of river water, 96 of sea water and 632 of various types of food. Two hundred and nine strains of campylobacter were isolated (9%), most of which were Campylobacter jejuni (80%), with particular frequency in food products (chicken carcass 45.7%, ground meat and sausage 18.1%) and in river water (31.3%). In contrast, the samples of sea water and dairy cheese products were always negative. It may be concluded that the spreading of campylobacter in the Pesaro-Urbino area is mainly associated with food products of animal origin. Therefore, better controls in the processing of these products may be necessary.

Animals↗
PubMed1992

Prevalence of anti-HCV in subjects of various age groups.

812 serum samples from 382 males and 430 females from various age groups were examined. All the samples were tested for anti-HCV hepatitis C virus, anti-HBc and HBsAg with an enzymeimmunoassay. The total serum prevalence was 2.9% for anti-HVC, 22.2% for anti-HBc and 4.6% for HBsAg. The seropositivity rates of anti-HCV and anti-HBc tended to increase with age, while for HBsAg a more regular pattern was observed for the different subject groups. The fact that anti-HCV are more frequently found together with HBV markers confirms the existence of similar modes of transmission of the two viruses.

Adult↗
PubMed1990

Yersinia enterocolitica and related species isolated in the Pesaro and Urbino area (Italy) from 1981 to 1986.

A total of 23 strains of yersinias, Y. enterocolitica (17), Y. frederiksenii (5) and Y. intermedia (1) characterized according to bio-serogroup and phage type, were isolated from human, animal and environmental samples during a 5-year period. It appears that in the Pesaro-Urbino area Yersinia spp. are infrequent and the strains of Y. enterocolitica belong to environmental and rarely to human pathogenic bioserogroups.

Adolescent↗