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Infections due to biofilm-producing microorganisms are one of the main causes for the failure of dental implants. Increasing efforts have been made in order to develop new strategies to prevent biofilm formation. In this study, the biofilm development on a newly designed laser-modified titanium implant surface was evaluated and compared to that on conventional sandblasted titanium used in implant dentistry. The amount of biofilm produced by Staphylococcus aureus, Pseudomonas aeruginosa and Porphyromonas gingivalis isolated from peri-implantitis was assessed by a semi-quantitative spectrophotometric method and by confocal laser scanning microscopy. Results showed a lower biofilm production on laser-modified surface compared to the sandblasted one. In particular, a significantly lower total volume of the biomass was observed on laser-modified surface, while no significant changes in live/dead bacteria percentages were noticed between materials. Modifying the topography of the conventional implant surface with laser ablation could represent a promising approach for inhibiting biofilm formation.

The aim of this work was to evaluate if dietary supplements for medical use available on the Italian and European market in 2011 were correctly labelled in terms of amount of viable bacteria, identity of species or genera and lack of cross contamination by species out of label. Fourteen in twenty-four products (58%) contained all the labelled species in the declared amount and were free of bacterial contamination. Ten in twenty-four products (42%) did not contain the labelled bacterial amount. Moreover, in four of these products (17%), we could not find any viable colony of at least one of the declared species. In two of them the DNA of all missing species could be detected by extracting DNA directly from the product. In conclusion, some products available on the Italian and European market in 2011 were not correctly labelled and did not comply with the specific guidelines.

Orthopaedics is currently the largest market of biomaterials worldwide and implant-related infections, although relatively rare, remain among the first reasons for joint arthroplasty and osteosynthesis failure. Bacteria start implant infection by adhering to biomaterials and producing biofilms, which represent a major reason for bacterial persistence, in spite of antibiotic treatment and host's defence. In the last two decades, a number of different antibiofilm agents have been studied and both in vitro and in vivo results appear now promising, even if their effective role in orthopaedics remains to be assessed. In this review, we introduce an original classification of antibiofilm agents, based on their mechanism of action and examine the available data concerning their possible application to orthopaedic implant-related infections. Molecules that interfere with biofilm production (biofilm prevention agents) include anti-adhesion compounds, quorum sensing inhibitors, non-steroideal anti-inflammatory drugs, and antimicrobial peptides; N-acetylcysteine and specific enzymes promise the greatest therapeutic possibilities by disrupting established biofilms (biofilm disrupting agents). The identification of antimicrobials able to bypass the biofilm barrier (biofilm bypassing agents), and antibiofilm vaccines are further strategies aimed to reduce the impact of biofilm-related infections, opening new pathways in controlling implant-related infections. However, this review shows that still insufficient knowledge is currently available as to regard the efficacy and safety of the investigated antibiofilm strategies to treat infection that involve bone tissue and biomaterials commonly implanted in orthopaedics, pointing out the need for further research in this promising field.

Antibiotic resistance in probiotic strains is a matter of interest due to the increase in consumption of probiotic products. Many studies have evaluated the antibiotic susceptibility of lactobacilli or the presence of resistance determinants, while knowledge on selection of resistance during exposure to antibiotics is still limited. Our aim was to evaluate the behavior of Lactobacillus rhamnosus GG ATCC 53103, a well-known probiotic microorganism, during exposure to erythromycin, tetracycline, amoxicillin/ clavulanate and ciprofloxacin. Our study demonstrated that prolonged exposure to erythromycin and ciprofloxacin could select mutants with reduced susceptibility, even if these modifications in susceptibility could not be attributed to known antibiotic resistance genes or genetic mutations.

Probiotics are widely used to prevent and treat several diseases. Many commercial products are available worldwide. However, there is no clear international or local legislation about them and previous studies showed that most of the tested products are not in conformity with international guidelines. The aim of this study was to determine if products available in the USA market in 2009 were correctly labeled in terms of quantity of viable bacteria, identification of species and cross contamination by species not on the label. Disturbingly, we found that only 4 of 13 products (31%) were in accordance with label claims. Our results suggest the need for adequate control of probiotic production as well as periodical screenings by competent organizations to monitor the effect of storage on product quality.

Conclusions: The results of this study suggest that atypical bacteria may be involved not only in acute upper airway diseases but also in recurrent infections requiring adenoidectomy and/or tonsillectomy. Therefore, their identification, followed by an appropriate treatment, should be considered., Objective: Although viruses and group A beta-haemolytic streptococci (GABHS) represent the most frequent bacterial aetiological agents of paediatric upper respiratory tract infections (URTIs), chlamydia and Mycoplasma pneumoniae have also been found in acute tonsillopharyngitis. Nevertheless their relevance in chronic or recurrent URTI has never been evaluated. This study aimed to further address the role of atypical bacteria in recurrent URTIs requiring adenoidectomy and tonsillectomy., Methods: Samples from 55 consecutive children who underwent adenoidectomy and/or tonsillectomy for recurrent or chronic URTI were cut transversely into smaller sections of 5 mm. Each section was pooled and assayed by specific PCR for viruses and bacteria., Results: Adenovirus was detected in 10 patients (18.2%), influenza A virus in one patient and influenza B virus in another. None of the other tested viruses was found. GABHS was found in 37 patients (67.3%). Moraxella catarrhalis and Haemophilus influenzae were detected in 30 patients (54.5%). M. pneumoniae was detected in 6 patients (10.9%) and C. pneumoniae was found in 10 patients (18.2%).

Probiotics are gaining increasing scientific and commercial interest as functional foods. Their success has led to the development and marketing of a broad range of products based on probiotics. In this context, resolution of the taxonomy of microbial species remains a key point, since different species belonging to the same genus may have different beneficial properties. Lactobacillus sporogenes, which should be correctly classified as Bacillus coagulans, represents the archetypal misidentified probiotic and its inclusion among probiotics has often been a matter of debate. Since this bacterium shows characteristics of both genera Lactobacillus and Bacillus, its taxonomic position between the families lactobacillaceae and bacillaceae has often been discussed.This review summarizes the salient probiotic features of L. sporogenes /B. coagulans by examining currently available information. Although the use of L. sporogenes spores as a probiotic has increased in recent years, clinical evidence of its benefits are limited to only a few studies involving small patient populations.

Background: Cefepime is a fourth-generation cephalosporin usually reserved for treating severe nosocomial pneumonia, as well as empirical treatment of febrile neutropenia, uncomplicated and complicated urinary tract infections, uncomplicated skin and skin structure infections, and complicated intra-abdominal infections., Objective: Since reports of neurotoxic effects and of an all-cause mortality higher with cefepime than with comparators have created some concerns regarding its safety, this paper reviews data available in the PubMed database up to December 2007 on cefepime safety., Methods: Literature data from PubMed obtained by combining cefepime and safety, or cefepime and clinical trials, were examined., Results/conclusions: Caution in the use of cefepime should be adopted until new evidence on cefepime safety is available.

Six commercial probiotic products produced and marketed Italy (containing Lactobacillus GG, Lactobacillus casei DG, Lactobacillus reuteri, Bacillus clausii spores, Bifidobacterium longum and Saccharomyces boulardii) were assayed for their stability during storage, acid, base and bile tolerance and adherence to human intestinal cells. Results indicate that storage, even at conditions established by manufacturers, affects the microbial content of products based on B. longum and partially of that containing L. casei GG . Differences in acid and bile tolerance were found for the products, S. boulardii being better able to survive acid and bile than bacteria. Vegetative cells of B. clausii and B. longum were more susceptible than lactobacilli to low pH values, while fewer differences were found for bile tolerance. Lactobacilli and only partially B. longum, were able to adhere to Caco-2 cells, while S. boulardii and B. clausii showed reduced adherence to human intestinal cells. In conclusion, the products did not completely fulfill all probiotic attributes.

The objective of this multicenter, randomized, controlled, parallel group trial was to evaluate the efficacy of levofloxacin 250 mg oral, once daily (LVFX), placebo one tablet oral once daily (Placebo [P] group) and ciprofloxacin (CPFX) 500 mg oral, twice daily (single blind), prophylaxis in preventing bacteriuria (> or = 10(3) CFU/ml) in post-surgical catheterized patients. In the modified intention-to-treat (M-ITT) population of the 82 enrolled patients, negative bacteriuria was observed in 92% of LVFX group, in 80% of P group and in 100% of CPFX group while in the per-protocol (PP) population figures were: 100%, 86.4% and 100% respectively. Only one symptomatic urinary tract infection and one surgical wound infection were observed in the P group. Both drugs were well tolerated, showing a safety profile comparable to placebo. The high frequency of negative bacteriuria in the placebo group sounds encouraging as it underlines that the adoption of closed urinary drainage system catheters in hospital setting may reduce the frequency of hospital-acquired infections.

This study evaluated the effects of exposure to serum, tonsils and breakpoint drug concentrations of clarithromycin, azithromycin, cefixime and amoxicillin/clavulanate on Streptococcus pyogenes susceptibility. Frequency of mutation and development of resistance after ten passages on antibiotic gradient plates, followed by ten passages without antibiotic, were determined. Phenotypes of macrolide-resistant strains grown at the end of multi-step selection were also determined. Azithromycin induced a surge of resistant strains more rapidly and frequently than clarithromycin, particularly at tonsils concentrations. With amoxicillin/clavulanate no strains showed minimum inhibitory concentrations (MICs) higher than the susceptibility breakpoint. Mutational frequencies were higher for azithromycin, at serum and breakpoint drug concentrations, than for the other drugs. Most of the macrolide resistant strains showed an MLS(B) phenotype. In conclusion, the ability to prevent the occurrence of resistance in clinical isolates of S. pyogenes was similar for amoxicillin/clavulanate and clarithromycin followed by cefixime > azithromycin when tonsil drug concentrations were considered, and greater for amoxicillin/clavulanate followed by clarithromycin > cefixime> azithromycin, at breakpoint and serum concentrations.

In this study the effects of exposure to serum, lung and breakpoint concentrations on Streptococcus pneumoniae susceptibility to clarithromycin, azithromycin, amoxicillin/clavulanate, levofloxacin and moxifloxacin were evaluated. Development of resistance was determined by multi-step and single-step methodologies. In the first experimental set, minimum inhibitory concentrations (MICs) were determined after 10 passages on antibiotic-gradient plates and 10 passages on antibiotic-free plates. Acquisition of resistance was defined as an increase of > or = 4-fold from the starting MIC. In single-step studies, the rate of spontaneous mutations was calculated after a passage on antibiotic-containing agar plates. Azithromycin and levofloxacin gave the highest number of strains with MIC increased of at least 4 times the starting value, followed by moxifloxacin and by clarithromycin which only at the lowest concentration tested selected for resistance in 5 strains. Amoxicillin/clavulanate never displayed > or = 4-fold MIC increase. Frequencies of mutation were lower for clarithromycin and moxifloxacin than for the comparators. At lung concentrations clarithromycin had limited potential to select for resistance.

This study compared the potential synergy of levofloxacin and ciprofloxacin in combination with cefepime, ceftazidime, imipenem, piperacillin/tazobactam or amikacin, against extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli by using checkerboard and time kill studies. Moreover, selection of resistance was determined by frequency of mutations and by calculating the increase in minimum inhibitory concentrations (MICs) after five serial subcultures on antibiotic-containing plates. Synergy occurred more often with levofloxacin combined with imipenem (7/10 strains) and with levofloxacin or ciprofloxacin with amikacin (10/10) than for the other combinations. Time kill studies showed synergy for levofloxacin combined with amikacin, ceftazidime, imipenem or piperacillin/tazobactam, and for ciprofloxacin combined with amikacin, cefepime or imipenem. Antibiotic combinations selected for resistance less frequently than antibiotics alone. Mutation frequency was <10(-12) for all combinations. In conclusion, the combination of a fluoroquinolone with a beta-lactam or amikacin may provide improved antimicrobial activity and help limit the occurrence of resistance in ESBL-producing E. coli strains.

Scientific evidence of the prevention and therapy of some intestinal diseases is accumulating in regard to probiotic products. However, sufficient information on the use of probiotics in specific therapies is not yet available and, above all, there is no clear legislation about these products in Europe. In this study, we evaluated five different probiotic products commercially available in Italy for their qualitative and quantitative microbial content after about 12 and 22 months of storage. We also evaluated the stability of lactobacilli to 0.3% bile salts and to pH of 3.58 and 7.98. There were discrepancies between the declared content and our results found after storage for 4 of the tested products. Bile salts and basic pH did not affect the growth of the lactobacilli tested, while for 2 tested products 6 hours at acid pH produced a complete inhibition of bacterial growth. Our results suggest the need for clear legislation and adequate control of the manufacturing of probiotic products.

Moxifloxacin is a recent fluoroquinolone with an antibacterial spectrum encompassing both aerobic Gram-negative and Gram-positive strains, as well as anaerobic bacteria. In this study the activity of moxifloxacin against Streptococcus pneumoniae, Staphylococcus aureus, Moraxella catarrhalis, Haemophilus influenzae, Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa, and effects of subinhibitory concentrations on bacterial morphology and adhesion properties were compared with those of amoxicillin, clarithromycin and ceftriaxone. The in vitro activity of moxifloxacin against Gram-positive and Gram-negative pathogens was equal to or better than that of comparators. Subinhibitory concentrations of moxifloxacin significantly affected bacterial morphology of S. pneumoniae, M. catarrhalis, H. influenzae and P. aeruginosa, leading to formation of spherical forms and filaments. Moreover, bacterial adhesion to buccal cells and fibroblasts was reduced after treatment with 1/4 and 1/8 X MIC of moxifloxacin. In conclusion, subinhibitory concentrations of moxifloxacin remarkably interfere with some bacterial pathogenic factors, thereby contributing to its antimicrobial activity.

The bactericidal activity of levofloxacin, ciprofloxacin, moxifloxacin and norfloxacin against clinical isolates conventionally classified as resistant to fluoroquinolones were compared at their maximum concentrations in serum, urine (except moxifloxacin) and bronchial mucosa (except norfloxacin). Time killing curves against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Streptococcus pneumoniae were performed. Serum concentrations of the tested drugs were not able to produce a bactericidal effect on fluoroquinolone-resistant strains. In the urine series, levofloxacin was always bactericidal (decrease > or = 3 logs CFU/ml), while norfloxacin and ciprofloxacin were bactericidal on E. coli (both), P. mirabilis (norfloxacin) and P. aeruginosa (ciprofloxacin). In the bronchial mucosa series, S. pneumoniae was rapidly killed by levofloxacin and moxifloxacin, and K. pneumoniae by levofloxacin after 12 hours. In conclusion, the maximum levofloxacin concentrations achievable at certain body sites allowed killing even of strains defined as resistant by conventional breakpoints.

Vaginal infections caused by Candida spp., other yeasts and Trichomonas vaginalis are problematic mainly due to the various factors involved in development of infection and to the failure of common treatments. In this study we investigated the presence of synergistic activity of econazole and ibuprofen isobuthanolammonium against 310 different vaginal isolates, by using the microdilution broth assay to test in vitro antimicrobial activity and the effect of the two drugs on phagocytosis and intramacrophagic cellular killing of mouse peritoneal macrophages. The effect of sub-inhibitory concentrations of econazole / ibuprofen isobuthanolammonium combination on Candida albicans germ tube formation was also evaluated. The in vitro antifungal activity of econazole was notably improved by addition of ibuprofen isobuthanolammonium. Macrophage killing of C. albicans was significantly increased by the two drugs and also germ-tube formation was significantly affected. We conclude that the addition of ibuprofen isobuthanolammonium to econazole provides better in vitro antifungal activity. However, further studies are needed to elucidate the in vivo action of this formulation.

In this study the antibacterial and antifungal properties of propolis, a natural product of bees, have been investigated against different pathogens. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined according to NCCLS standards on 320 strains including Staphylococcus aureus, Group A beta-hemolytic streptococci, Streptococcus pneumoniae, Moraxella catarrhalis, Haemophilus influenzae, Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Candida albicans. Time-kill curves were assessed for susceptible microorganisms, testing 0, 0.5, 1, 2, 4 x MIC for propolis, by counting viable bacteria after 0, 3, 6, 24 hours and viable yeasts after 0, 3, 6, 24 and 48 hours. Propolis showed good antimicrobial activity against most of the isolates, particularly S. pneumoniae, H. influenzae and M. catarrhalis, but not against Enterobacteriaceae. Time-kill curves demonstrated bacteriostatic rather than bactericidal activity of propolis, the latter being evident only at high concentrations.

Helicobacter pylori infection is currently treated with antimicrobial agents in combination with antacids. Recent studies have described the in vitro bactericidal activity of fish oils and polyunsaturated fatty acids on H. pylori, and reduced rates of duodenal ulcer in people with high intake of these substances. In this study we have tested the in vitro activity of three different fish oil formulations on H. pylori strains using the Kirby Bauer method and an in vitro antibacterial test on bacteria adhered to cellular monolayers. Our results demonstrate that one of the oils is active. In this study we cannot speculate on which component of the active oil is effective and its mechanism of action, but we hypothesize that a higher concentration of icosapentaenoic acid and docosahexaenoic acid occurs in the active oil. Further in vitro and in vivo studies are needed before proposing fish oils as treatment of H. pylori infection.

Helicobacter pylori is the causative agent of gastritis and a co-agent in other gastroduodenal diseases. Gastroduodenal ulcer and MALT-lymphoma in particular, regress when patients are administered antimicrobial agents to eradicate infection. Sometimes eradication is not definitive and is difficult to check. The aim of our study was to test the antimicrobial activity of omeprazole on H. pylori in comparison with ampicillin and other anti-H2 drugs (ranitidine and famotidine), and to evaluate their interference with bacterial adhesion of H. pylori. We also compared results of the agar dilution antibacterial sensitivity test on H. pylori to those obtained using a bacteria adherence to cell monolayers model, to see if drug activity was different against adhered bacteria. We evaluated omeprazole and ampicillin MIC90s (minimum inhibitory concentrations) against 20 H. pylori isolates by traditional agar dilution method and by exposing previously adhered bacteria to an Hep-2 monolayer to different drug concentrations. The activity against bacteria adhered to cell lines was evaluated by counting viable adhered bacteria after 1, 6, 12 hours of contact with drug. Interference with adherence to Hep-2 cells was also tested. Omeprazole and ampicillin MICs were comparable to other findings (omeprazole MIC90 was 12.5 microg/ml and ampicillin MIC90 was 0.016 microg/ml), while higher concentrations were necessary (4 x MIC90) against adhered bacteria. These findings suggest that MICs evaluated with traditional assays can have different predictivity than tests on adhered H. pylori.

In our study we considered the possible interference of cefetamet-pivoxil with the intestinal microflora. We used 60 germ-free mice in which an intestinal microflora similar to the human one had been implanted. They were treated with 14.3 mg/Kg/die (standard dose) and a 28.6 mg/kg/die (daily dose) of cefetamet-pivoxil by oral route. The results obtained in vivo proved that cefetamet-pivoxil at therapeutic doses does not influence the normal intestinal microflora.

The aim of our study was to evaluate the interference of fosfomycin trometanol (F.T.), at subinhibitory concentrations (1/4 and 1/8 MICs), on some urovirulence factors of Escherichia coli (12 strains). We tested fimbriae production, adhesion to uroepithelial cells, hydrophobicity, motility and hemolysin production of E. coli grown in the presence or absence of F.T. The strains tested, grown in the presence of F.T. (1/8 MIC), were less capable of adhering to uroepithelial cells, had less hemagglutination and reduced motility. This behavior was enhanced at 1/4 MIC of F.T. The hemolysin production and hydrophobicity properties present in some of our tested strains also were significantly decreased when the E. coli were grown in the presence of sub-MIC concentrations of F.T. These results suggest that F.T. may be of clinical use as treatment for acute urinary tract infection and in pyelonephritis prophylaxis.