T serotyping and genomic profile of erythromycin-resistant or -sensitive Streptococcus pyogenes isolated in Campania Region, Italy.

Streptococcus pyogenes causes mild infections, such as pharyngitis, and severe infections, such as necrotizing fascitis. In recent years, erythromycin-resistant strains of S. pyogenes have been reported in many countries. In some areas of Italy, increased rates of erythromycin resistance were first observed in the mid-1990s. Here, we report epidemiological T serotyping, invasiveness, erythromycin resistance, and PFGE patterns of 99 S. pyogenes strains isolated at the Laboratory of Clinical Microbiology of the Second University of Naples, Italy. Regarding T serotyping, 26 of 99 strains were W+, 16 strains were U+, 16 were X+, and 14 were agglutinated by anti T serum. A low percentage revealed Y+. Twelve strains were not T serotyped. PFGE patterns showed species polymorphism; however, inside the various serotypes, we demonstrated a fair homogeneity. No correlation among invasiveness and T serotype or PFGE pattern has been shown. Twenty-two of 99 strains were erythromycin-resistant.

Porins from Salmonella typhimurium accelerate human blood coagulation in vitro by selective stimulation of thrombin activity: implications in septic shock DIC pathogenesis.

The effect of porins, major hydrophobic outer membrane proteins purified from Salmonella typhimurium, on human blood coagulation was investigated. It was found that micromolar concentrations of porins accelerated markedly human blood coagulation in vitro. Using appropriate experiments, data were obtained showing that the main target of the porin-induced procoagulant effect was thrombin. A possible binding of porins with thrombin has been suggested to be the basis of this effect. The implications of this finding in the pathogenesis of the disseminated intravascular coagulation syndrome (DIC) occurring during the Gram-negative septic shock is discussed.

Properties of Yersinia enterocolitica porins: interference with biological functions of phagocytes, nitric oxide production and selective cytokine release.

We have extracted and purified Yersinia enterocolitica ATCC 9610 porins that have molecular weights of 36-38 kDa. They inhibited phagocytosis and phagosome-lysosome fusion (30%) in human monocytes and caused enhanced nitrite production. Preincubation of polymorphonuclear neutrophils with porins (1-10 micrograms/ml/10(6) cells) induced a reduction in chemotaxis, adherence to nylon wool and chemiluminescence. Human lymphomonocytes treated with Y. enterocolitica porins showed a distinctive cytokine profile. Interleukin-1 alpha, interleukin-6 and tumour necrosis factor alpha were released within 3-6 h, while interleukin-8, gamma interferon and granulocyte-macrophage colony stimulating factor were released after 18 h. Interleukin-3 and interleukin-4 were not detected at up to 48 h of incubation. In conclusion, these immunomodulating and histotropic properties may account for Y. enterocolitica infection and its sequelae.

Histamine2 antagonists in allergic rhinitis. Possible role in the control of cellular immune reaction.

We studied effects of monoclonal antibodies on lymphocyte subpopulations in patients with allergic rhinitis treated with histamine2 antagonists. The OKT4/OKT8 ratio after treatment showed a statistically significant decrease compared with initial values, the expression of a relative increase in the OKT8 subpopulation containing the suppressor fraction. In control patients no significant variations were observed. These results confirm our hypothesis that histamine2 antagonists act in allergic rhinitis by modulating the activity of T-suppressor lymphocytes reduced in atopic patients.

Pulmonary disposition of lomefloxacin in patients with acute exacerbation of chronic obstructive pulmonary disease. A multiple-dose study.

In this study we have measured the concentrations of lomefloxacin at steady state in serum and in the intrapulmonary region at specified intervals for 24 h following administration of the last dose of drug in patients suffering from acute exacerbation of chronic obstructive pulmonary disease (COPD). Twenty subjects were enrolled. They received lomefloxacin 400 mg orally once-daily for 5 consecutive days. All patients were divided into five groups, with 4 subjects in each group, according to sampling times (2, 4, 8, 12, and 24 h after the last dose). At bronchoscopy, bronchial biopsies and bronchoalveolar lavage (BAL) were performed. At 12 h after the last dose, serum concentration of lomefloxacin was >1.0 microg/mL and at 24 h it was still detectable, but, at all times, the concentrations in bronchial secretion, bronchial mucosa, and epithelial lining fluid (ELF) were greater than the concentrations in serum [bronchial secretions (pg/mL) = 2.5+/-1.2; 2.2+/-1.0: 2.0+/-1.1; 1.8+/-1.1; 0.6+/-0.3. bronchial mucosa (microg/g) = 5.9+/-2.1; 6.2+/-1.8; 2.6+/-2.2; 1.9+/-1.5; 1.0+/-0.9. ELF (microg/mL) = 6.9+/-2.8; 5.9+/-2.6; 3.1+/-1.9; 2.2+/-1.0; 0.8+/-1.3. serum (microg/mL) = 3.2+/-1.4; 2.8+/-0.9: 2.1+/-1.5; 1.2+/-1.1; 0.4+/-0.81. We must stress that we observed a large inter-individual variability in concentrations. Our data show that lomefloxacin once-daily induces high and sustained concentrations in the various potential sites of pulmonary infection and clearly indicate that the pharmacokinetic behavior of this fluoroquinolone permits once-daily administration in patients with acute exacerbations of COPD.

Presence of Legionella spp. in thermal springs of the Campania region of south Italy.

Water samples from 66 thermal springs in the Campania region of South Italy were cultured for Legionella spp., Pseudomonas aeruginosa, and indicators of faecal pollution. The temperature of the sources ranged from 21 degrees C to 59.5 degrees C. Legionella pneumophila, serogroup 7-10, was isolated from two out of 60 sources on the Island of Ischia and Legionella dumoffii from one mainland source. The temperatures of these sources were 35.2 degrees C, 48.2 degrees C, and 52.0 degrees C respectively. Twelve sources were positive for P. aeruginosa and 6 for Escherichia coli. Our results found that Legionella spp. were present in only three thermal springs, indicating that in the hydrothermal area of the Campania region the presence of this microbial species is very scarce.

Effects of sodium polystyrene sulfonate on gingival plaque: microbiological investigation and clinical follow-up.

A new antiplaque agent was tested on nine subjects. The antiplaque agent, a 5% aqueous solution (p/v) of sodium polystyrene sulfonate, applied on the tooth surfaces by daily topical application for two weeks, caused a statistically significant 30% reduction of plaque index (PI), with corresponding reduction of total bacteria and qualitative modifications of plaque formation with reduction of Gram-negative bacteria.

Effect of hyperbaric oxygen therapy in experimental subcutaneous and pulmonary infections due to Pseudomonas aeruginosa.

About 80% of nosocomial infections are caused by aerobic bacteria. Pseudomonas aeruginosa is a Gram-negative bacterium belonging to the Pseudomonadaceae family; P. aeruginosa is responsible for 6-22% of all hospital infections. The aim of this study was to evaluate the efficacy of hyperbaric oxygen (HBO2) therapy (2 atm abs x 55 min.day-1) alone for 8 days and combined with antibiotic chemotherapy (amikacin 15 mg.kg-1.day-1 for 8 days by intraperitoneal route) in rats infected subcutaneously and via the pulmonary route. In the rats infected by P. aeruginosa, HBO2 induced a reduction in mortality and morbidity with bacteria eradication in blood culture, bronchial aspirate, and skin biopsies when compared to control. These effects were increased by the use of amikacin, an antibiotic used for the treatment of sensitive Gram-negative bacteria.

[The role of anaerobe adhesion in the colonization of the vaginal mucosa]. / L'aderenza degli anaerobi nella colonizzazione della mucosa vaginale.

Some our previous research works on bacterial adhesion to vaginal cells in the different phases of the menstruum showed that adhesion changes depending on changing environmental conditions. We therefore considered interesting to extend our investigations to anaerobic flora, in the light of recent observations intended to attribute an important role to anaerobic flora in the pathogenesis of vaginitis. The results obtained so far indicate that the maximum adhesion capability is found in the middle of the menstruum. The very low adhesion of bacteria belonging to the Leptothrix genus remains substantially unaltered throughout the menstruum. Low adhesion is also found in sporogenic bacteria, whereas the coccoid ones have a stronger adhesion, particularly about the middle of the menstruum. With lower pH values adhesion of the anaerobic flora is enhanced, whereas in the final phase of the menstruum, with higher pH values, adhesion is reduced. Competition tests evidence a stronger adhesion of coccoid as compared to bacillar types.

New strategies in dandruff treatment: growth control of Malassezia ovalis.

BACKGROUND: Cutaneous infections induced by Malassezia ovalis (Pityrosporum ovale) represent a therapeutic problem due to the high rate of recurrence. OBJECTIVE: We studied feasible strategies to control the growth of M. ovalis, compatible with topical use in cosmetic formulations. Studies were performed on the effects of pH, ionic strength, cinnamic acid and related compounds on mycotic growth. METHODS: M. ovalis was cultivated in modified Sabouraud agar. The effects of pH, ionic strength and cinnamic acid and related compounds on mycotic growth were studied by the membrane filter method. RESULTS: In vitro growth of M. ovalis is strongly affected by pH and ionic strength. pH 4.5 induced a growth inhibition of about 95% and 1 M NaCl, at the optimal growth pH, reduced cell growth by over 90%. Cinnamic acid showed an inhibitory effect of 50% at 0.005 g/dl; 30 min incubation with cinnamic acid 0.5 g/dl had a mycocidic effect. CONCLUSION: These results suggest the use of cosmetic compositions containing cinnamic acid or buffered acidic lotions and shampoos in the treatment of M. ovalis infections of the scalp, eventually in addition or alternative to antimycotic drugs or in maintenance therapy. Cosmetic formulations with high ionic strength or skin irritant derivatives such as cinnamaldehyde cannot be proposed for practical use.

Effects of Cetyltrimethylammonium naproxenate on the adherence of Gardnerella vaginalis, Mobiluncus curtisii, and Lactobacillus acidophilus to vaginal epithelial cells.

BACKGROUND AND OBJECTIVES: A decreased concentration or total disappearance of Lactobacillus acidophilus in the vagina constitutes a frequent observation in bacterial vaginosis. GOAL OF THE STUDY: Cetyltrimethylammonium naproxenate has been evaluated in vitro to detect antiadhesive properties at subinhibitory concentrations for Gardnerella vaginalis and Mobiluncus curtisii to vaginal epithelial cells (VEC). STUDY DESIGN: Bacterial strains 14C- and or 3H-labeled were tested for adherence and competition to binding sites in VECs before and after treatment at sub-MIC with cetyltrimethylammonium naproxenate. RESULTS: In control tests of adherence, G. vaginalis and M. curtisii had their maximal adhesion at pH 5.4, L. acidophilus at pH 4.4. Preincubation of G. vaginalis and M. curtisii with cetyltrimethylammonium naproxenate 2.5 mg/mL (subinhibitory concentration) at pH 5.4 reduced adherence to VECs respectively by 48.3% and 34.1%. The same treatment of L. acidophilus showed no statistically significant difference. Treatment of VECs alone did not modify adherence. Competition tests between L. acidophilus and G. vaginalis and between L. acidophilus and M. curtisii showed that, in small quantities, L. acidophilus could compete with G. vaginalis and M. curtisii for binding sites in VECs at pH 4.4, when pretreated with cetyltrimethylammonium naproxenate. At a higher pH (4.8 and 5.4), L. acidophilus in higher quantities did not compete for binding sites occupied by G. vaginalis and M. curtisii. CONCLUSIONS: Cetyltrimethylammonium naproxenate at subinhibitory concentrations modifies the adhesiveness of G. vaginalis and M. curtisii to VECs, reducing it by 48.3% and 34.1%, respectively. Adhesion of L. acidophilus to VECs is not impaired by pretreatment with cetyltrimethylammonium naproxenate at pH 4.4, even if they are in low number and compete for binding sites against pathogens. At higher pH levels, L. acidophilus did not compete for binding sites occupied by G. vaginalis and M. curtisii.

Effects of a new topic amikacin formulation on chemotaxis and release of profibrotic factors by human monocytes.

Aminoglycosides, widely used because of their large-spectrum antibiotic effects, should not interfere with the healing process of an ulcer or an infected wound. We evaluated the effects of amikacin or the excipients present in the topic formulation BG 90, powder 2. 5% (Boniscontro e Gazzone S.r.l., Rome, Italy), on human monocyte chemotaxis and the release of profibrotic factors by resting or lipopolysaccharide (LPS)-activated monocytes. The chemotactic response of monocytes to zymosan-activated serum is not modified in vitro by pre-incubation of the cells with amikacin (2 and 10 microg/ml/10(6) cells) or excipients. Unstimulated monocytes did not secrete appreciable amounts of cytokines. Vice versa, amikacin-stimulated cells released platelet-derived growth factor AB (PDGF-AB) (about 340 pg/ml), transforming growth factor (TGF)-beta1 (about 10 pg/ml), and tumour necrosis factor (TNF)-alpha (over 1,100 pg/ml); among excipients, ZnO and vitamin E induced PDGF-AB release (about 320 and, respectively, 200 pg/ml), while stimulation of monocyte monolayers by the other excipients did not lead to appreciable cytokine release. As expected, LPS-activated human monocytes produced PDGF-AB, TGF-beta1, and TNF-alpha. When monocytes were co-stimulated with LPS and amikacin, the PDGF-AB and TGF-beta1 values almost overlapped with those from the stimulation of cells with LPS alone, while TNF-alpha production was slowly reduced. The results show a stimulating effect of aminoglycoside on the production of profibrotic factors and, therefore, on the healing process of wounds in addition to a modulating effect on the production of pro-inflammatory cytokines like TNF-alpha. Moreover, ZnO and tocopherol (free-radical scavengers), used as excipients in the topic formulation, induce the release of growth factors with profibrotic activity (PDGF-AB). Further research is warranted to explore the effects of this formulation in vivo, verifying whether the association of the antibiotic with scavengers has a double advantage in topical amikacin: on the one hand, it could limit the damage from free radicals, and on the other it could favour tissue healing.

Pulmonary penetration of dirithromycin in patients suffering from acute exacerbation of chronic bronchitis.

The aim of this study was to evaluate the concentrations of dirithromycin, a new macrolide antibiotic, in bronchial secretions (BS), bronchial mucosa (BM), epithelial lining fluid (ELF) and serum in 25 patients with acute exacerbation of chronic bronchitis after a 5-day, once-daily, dirithromycin regimen. All patients received dirithromycin, 500 mg (two 250 mg tablets) given orally once daily at 08.00 fasted, for 5 consecutive days. They were divided into five groups (n = 5 in each group) according to sampling time (24, 48, 72, 96 and 120 h, after the last dose). Mean serum concentrations remained low throughout the study (0.44 microgram/ml at 24 h, 0.31 microgram/ml at 48 h, 0.33 microgram/ml at 72 h, 0.12 microgram/ml at 96 h and 0.11 microgram/ml at 120 h, respectively), although they were higher than the MICs for Moraxella catarrhalis for up to 72 h and than that for Streptococcus pneumoniae for up to 120 h after the last dose. By contrast, in all other samples, mean concentrations were higher than the MICs for many relevant respiratory pathogens for at least 3 days, and higher than that for S. pneumonia and M. catarrhalis for up to 120 h (mean concentrations measured 2.67, 2.15, 1.74, 0.27 and 0.17 micrograms/ml, respectively, in BS; 2.59, 2.59, 1.96, 0.41 and 0.27 micrograms/g, respectively, in BM; 2.21, 2.25, 1.57, 0.22 and 0.15 micrograms/ml, respectively, in ELF). These findings demonstrate that dirithromycin is concentrated in each of these potential sites of infection for up to 3 days after a 5-day course of therapy. Therefore, short-term therapy with dirithromycin may be useful for many respiratory infections.

Survival to lipopolysaccharide, cytokine release and phagocyte functions in mice treated with different total parenteral nutrition regimens.

Effects on host defenses of Total Parenteral Nutrition (TPN) with long- (LCT) and medium-chain triglycerides (MCT) were studied. Survival to lipopolysaccharide (LPS) challenge, blood clearance of Escherichia coli, in vivo and in vitro production of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were investigated. In BALB/c mice, LCTs produced a 25% reduction in mortality, compared with controls. TPN performed with a LCT plus MCT mixture reduced mortality by 50%. Spasms appeared after 18 h and 12 h respectively in mice treated with LCT-MCT mixture or LCTs alone, respect to controls (8 h). The LCT-MCT mixture produced a 67% blood clearance of E. coli after 1 h, while the treatment with LCTs alone had no significant effects compared to controls (about 40%). The LCT-MCT mixture induced a 50% increase in chemiluminescence respect to controls. A 33% increase was observed in rats treated with LCTs alone. TNF-alpha serum levels after challenge with LPS were not modified by any of the triglycerides or their combinations. IL-6 increased by 43% with LCT-MCT mixture and by 39% with LCTs alone versus controls. After a 3 h in vitro treatment with LCTs, human monocytes were stimulated to release TNF-alpha at levels higher than those stimulated with the LCT-MCT mixture, and respect to controls. In contrast after 3 h the stimulation with LCT-MCT mixture induced a higher IL-6 release than controls and cells stimulated with LCTs alone, or with LPS.

Immunobiological activities of Helicobacter pylori porins.

Studies were carried out on some biological activities of Helicobacter pylori porins in vitro. We extracted and purified a porin with an apparent molecular mass of 30 kDa. Human polymorphonuclear leukocytes preincubated with H. pylori porins showed a decrease of chemotaxis, of adherence to nylon wool, and of chemiluminescence. Used as chemotaxins in place of zymosan-activated serum or as chemotaxinogens in place of zymosan, the porins induced polymorphonuclear leukocyte migration. Human monocytes and lymphocytes cultivated in the presence of H. pylori porins released cytokines. Release of the various cytokines studied was obtained with differentiated kinetics and at various porin concentrations. Starting only 3 h after culture, tumor necrosis factor alpha is released quickly, reaching a peak at 18 h, at a porin concentration of 1 microgram/ml/10(6) cells. Interleukin-6 (IL-6) appears later, with a peak at 10 micrograms/ml/10(6) cells, while IL-8 is released after 6 h of culture, with a peak at 24 h, at a porin concentration of 10 micrograms/ml/10(6) cells, while IL-8 is released after 6 h of culture, with a peak at 24 h, at a porin concentration of 10 micrograms/ml/10(6) cells. Lymphocytes stimulated by H. pylori porins release gamma interferon after 18 h of culture at higher concentrations of porins (20 micrograms/ml/10(6) cells). Granulocyte macrophage colony-stimulating factor is released from 6 to 48 h at a concentration of 1 microgram/ml/10(6) cells, while both IL-3 and IL-4 are released after 18 h of culture at different porin concentrations (0.1 and 1 microgram/ml/10(6) cells, respectively). Our results lead us to think that during H. pylori infection, surface components, porins in particular, are able to induce a series of chain reactions ranging from the inflammatory to the immunological responses.

Adherence of bacteria to cardiac valve prostheses.

The adherence of bacterial cells to valvular prostheses has been studied. Bacteria were selected on the basis of their surface features (fimbriae, hydrophobicity and specific receptors). It was found that only strains having fimbriae and high cell surface hydrophobicity adhered to bioprostheses, while they did not adhere to metallic prostheses to any significant extent. Adherence to bioprostheses depended on the exposure time and it was affected by the saline concentration of the suspension medium. Furthermore, different bacterial binding capacity was observed for bioprostheses from different companies.

Effect of measles-mumps-rubella vaccination on polymorphonuclear neutrophil functions in children.

Adherence, metabolic burst and chemotaxis of polymorphonuclear neutrophils (PMNs) were examined in 15 children before and seven days after measles-mumps-rubella vaccine administration. In all children, PMN functions were significantly reduced on the seventh day. Adherence, metabolic burst and chemotaxis tested in three subjects one month after vaccination had returned to normal values. Only two children presented transient hyperpyrexia. We conclude that measles-mumps-rubella vaccine administration suppresses PMN functions without clinical consequences. This is probably because attenuated strains of vaccine viruses do not replicate in lymphoid tissues as extensively as do wild-type strains.

Decreased adherence of polymorphonuclear neutrophils in children with viral infection.

The adherence of polymorphonuclear neutrophils was examined in 16 children affected by enteritis, pneumonia, hepatitis and infectious mononucleosis. The results were compared with those obtained in 30 healthy adult volunteers and in 15 healthy children of the same age. Adhesiveness was significantly higher in adults than in healthy children, and significantly higher in healthy children than in children with viral infection. In 7 patients tested one month after regression of the disorder, PMN adhesiveness had returned to normal.

Rat seminal vesicle protein SV-IV and its transglutaminase-synthesized polyaminated derivative SPD2-SV-IV induce cytokine release from human resting lymphocytes and monocytes in vitro.

Micromolar amounts of SV-IV, one of the major proteins secreted from the rat seminal vesicle epithelium, induce in vitro a marked release of a variety of cytokines (interferon-gamma, tumor necrosis factor-alpha, interleukin 6, and granulocyte-monocyte colony-stimulating factor) from human resting peripheral blood mononuclear cells as well as from isolated resting lymphocytes and monocytes. This effect was found to be significantly higher when the spermidine adduct of SV-IV (Spd2-SV-IV), synthesized in vitro by the enzyme transglutaminase, was used instead of the native protein. Furthermore, the pretreatment of monocytes with transglutaminase caused an increase of the inducing effect of both native and modified SV-IV on the release of interleukin 6 from these cells. The inducing effect of these proteins on the cytokine release was markedly inhibited by actinomycin D and cycloheximide.