Labeling quality and molecular characterization studies of products containing Lactobacillus spp. strains.

The objective of the study was to characterize at species level by phenotypic and different molecular methods the strains of Lactobacillus spp. used as constituents of five oral and four vaginal products. Susceptibilities to representative antibiotics were evaluated. In addition, total viable counts at mid and 3 months to deadline of shelf life, in the different formulations and the presence of eventual contaminant microorganisms were investigated.In all oral products the molecular characterization at species level of the strains of Lactobacillus spp. confirmed the strains stated on the label, except for one strain cited on the label as Lactobacillus casei, that our study characterized as Lactobacillus paracasei. In oral products total viable cell content complied with content claimed on the label. In three out four vaginal products (one product claimed "bacillo di Döderlein"), molecular characterization complied with the bacterial name stated on the label. Two vaginal products reported viable counts on the label that were confirmed by our study. The other vaginal products, which did not report bacterial counts on the label, showed a similar decrease of viable counts at different dates to deadline compared to the others. From all the tested products, contaminant microorganisms and acquired resistance to representative antibiotics by the probiotic strains were not detected.

Streptococcus pyogenes emm types and subtypes of isolates from paediatric asymptomatic carriers and children with pharyngitis.

This study determined emm subtypes of Streptococcus pyogenes strains isolated from asymptomatic carriers and children with pharyngitis. All strains were previously investigated for fibronectin-binding genes (prtF1 and prtF2) and antimicrobial susceptibility. The most significant differences between the two groups, which share only 5 of the 14 detected emmsubtypes, concern the presence of the two more common emmsubtypes, 12.0 (50.0% vs. 3.1%, for asymptomatic carriers and children with pharyngitis, respectively) and 1.0 (28.1% vs. 0%, for children with pharyngitis and asymptomatic carriers, respectively).

In vitro inhibitory activity of Bifidobacterium longum BB536 and Lactobacillus rhamnosus HN001 alone or in combination against bacterial and Candida reference strains and clinical isolates.

Bifidobacterium longum BB536 and Lactobacillus rhamnosus HN001 are two strains frequently used as probiotic components in food supplements. The decrease of potentially pathogenic gastrointestinal microorganisms is one of their claimed mechanisms. The aim of this study was to investigate their ability, alone or in combination, to inhibit in vitro the growth of Gram-negative, Gram-positive and Candida reference strains and clinical isolates, using different methods. The cell-free supernatants were obtained by centrifugation and filtration from single or mixed broth cultures and the inhibitory activity was tested using both agar-well diffusion and broth microdilution methods. In order to get some preliminary information about the chemical nature of the active metabolites released in the supernatants, the inhibitory activity was investigated after neutralization, heat and proteolytic treatments. The highest inhibitory activity was shown by the untreated supernatant obtained from broth culture of the two probiotic strains, especially against bacterial reference strains and clinical isolates. This supernatant showed inhibitory activity towards Candida species, too. A decreased inhibitory activity was observed for the supernatants obtained from single cultures and after proteolytic treatment, against bacterial reference strains. The study suggests that the combination of B. longum BB536 and L. rhamnosus HN001 could represent a possible alternative against gastrointestinal and urinary pathogens either as prophylaxis or as treatment.

Microbiological and clinical periodontal effects of fixed orthodontic appliances in pediatric patients.

The aim of this study was to evaluate changes of microbiota in ten patients undergoing orthodontic treatment. For each patient clinical examination of gingival index (GI) and plaque index (PI) were performed at the first molars at: baseline (T1), 2 (T2), 4 (T3) and 12 weeks (T4). At the same time subgingival plaque and tongue samples were taken for the microbiological study. Clinical results showed that at T4, the mean PI score was significantly lower than T1 and the GI was markedly reduced. Microbiological results showed that at T1 and T4 facultative aerobic bacteria were prevalent, whereas anaerobic bacteria were more common at T2 and T3.

Complete Genome Sequence of Bifidobacterium longum W11 (LMG P-21586), Used as a Probiotic Strain.

We report the complete genome sequence of Bifidobacterium longum W11 (LMG P-21586) isolated from the intestinal microbiota of a healthy man. The analysis of the sequence may provide insights into the microbiological characteristics and the functional activity of this probiotic strain.

Immunomodulatory Effects of Bifidobacterium longum W11 Produced Exopolysaccharide on Cytokine Production.

BACKGROUND: Health benefits, including immune modulating capability, exerted by Bifidobacterium strains have been attributed to their exopolysaccharides (EPSs). OBJECTIVE: The effects of the purified EPS from B. longum W11 on cytokine production by peripheral blood mononuclear cells (PBMCs) alone or ConA-stimulated were investigated. METHOD: The production of IFN-γ, IL-1ß, IL-6 and IL-10 by PBMCs from healthy adult donors was analysed using purified EPS at two different concentrations (100 µg/mL and 200 µg/mL) and ConA, as an immunopotentiating marker. Moreover, the monosaccharide composition of the EPS from B. longum W11 was detected using HPLC analysis. RESULTS: The results demonstrated the ability of purified EPS to increase the production of the tested cytokines, except IL-10, in ConA-stimulated PBMCs. In not-stimulated-PBMCs, EPS increased the production of IL-6 (at 200 µg/mL) and IL-10 (at 100 µg/mL). The HPLC analysis showed the presence of main monomers, galactose and glucose (ratio 1:1 wt/wt), and small amount of rhamnose. CONCLUSION: The results of this study demonstrate the ability of the EPS produced by B. longum W11 to interact in vitro with the human PBMCs, showing an immune-regulatory profile alone and an immune stimulatory profile in ConA-stimulated PBMCs. This suggests putative applications for the EPS from B. longum W11 in different pathological conditions.

Chemical and biological properties of the novel exopolysaccharide produced by a probiotic strain of Bifidobacterium longum.

Bifidobacterium longum W11 is a commercialized probiotic that has an exopolysaccharide (EPS) layer covering its surface which could play a role in the beneficial properties attributed to the strain; thus, we have carried out chemical and biological analyses of this polymer. The eps cluster putatively involved in the polymer synthesis presented a unique structural organization not previously reported in bifidobacteria. B. longum W11 produced a complex polysaccharide blend with the main component composed of glucose and galactose. An exhaustive structural analysis identified two different repeating units: one linear [→6)-ß-Galf-(1→3)-α-Galp-(1→] and one, more abundant, with the same backbone in which the ß-Galf is 5-substituted by a ß-Glcp unit. The antioxidant capability and the lack of toxicity of the whole EPS W11 mixture, as well as some functional characteristics of the producing strain, such as the in vitro resistance to gastrointestinal conditions and the adhesion of colonocytes, were also determined.

Identification and antibiotic susceptibility of bacterial isolates from probiotic products available in Italy.

This study was carried out to assay the bacterial viability and the probable contamination of a range of probiotic products available in Italy and to test the susceptibility of the isolates. Eleven dried food supplements and five fermented functional foods were examined using different isolation media under standardized cultivation conditions. The identification was made by conventional phenotypic characteristics and biochemical tests. Among isolates from the probiotic products antibiotic susceptibility was detected using the E-test (ABBiodisk). Our results demonstrate that nine food supplements and two fermented foods claimed species which could not be isolated, whereas potential pathogens (i.e. Micromonas micros) were isolated. Lactobacilli displayed species-dependent antibiotic resistance. Atypical resistance occurred for penicillin in Lactobacillus acidophilus and Lactobacillus bulgaricus and for erythromycin in Lactobacillus lactis and Lactobacillus salivarius. A broad range of MICs was observed for cephalosporins and fluroquinolones. Aminoglycosides had poor activity against Lactobacillus isolates. Two of the four isolates of Bifidobacterium exhibited high resistance to trimethroprim/sulfametoxazole and to fluoroquinolones. Our results suggest that some probiotic products claim species that cannot always be isolated, and are sometimes contaminated by potential pathogens. Moreover, the probable transferable erythromycin or penicillin resistance among the lactobacilli isolated should be taken into account.

Predictive value of bacterial analysis of laparotomy wounds.

BACKGROUND: Despite improvements in antibiotic prophylaxis, surgical site infections represent the most common postoperative complication with important clinical consequences for patients. AIM: The hypothesis that a bacterial analysis of the surgical wound in the operating room could predict the likelihood of developing a clinical infection, and might allow a tailored and preemptive approach, aimed to reduce the consequences of an infection, seems appealing. We would like to present a prospective study on the predictive value of the bacterial analysis of laparotomy wounds. MATERIAL OF STUDY: Seventy eight prospective patients undergoing surgery were included in the study. To evaluate the risk factors associated with increased rate of wound infection, we performed a bacterial analysis of the wound. RESULTS: 48 patients out of 78 (61%) had positive cultures. 23 patients out of 32 patients (72%) who didn't receive antibiotic prophylaxis were positive to the wound culture whereas 25 patients out of 46 patients (54%) grew positive cultures in the group of patients that received antibiotic prophylaxis. None of the 30 patients with negative cultures developed clinical infection. Only 6 patients out of 48 patients who had positive cultures (12.5%) developed wound infection. Clinical infection occurred in 5 patients who had gram-negative contamination of the wound. No clinical infection occurred in patients who had gram-positive contamination. CONCLUSION: Wound cultures and their positivity are predictive tools to identify the patients that are at risk to develop wound infection. The positive predictive value of the bacterial analysis of the wound was 12.5%. KEY WORDS: Abdominal surgery, Bacterial analysis, Wound infection.

Bacteriological findings and antimicrobial resistance in odontogenic and non-odontogenic chronic maxillary sinusitis.

The main objectives of this study were to estimate the frequency of chronic maxillary sinusitis of dental origin, and to evaluate the microbiology of odontogenic and non-odontogenic chronic maxillary sinusitis. Aspirates from 59 patients with chronic maxillary sinusitis (47 non-odontogenic, 12 odontogenic), collected during a 3-year period, were microbiologically processed for aerobic and anaerobic bacteria. Moreover, antimicrobial susceptibility was evaluated in the isolated bacteria. In this study, 20 % of chronic maxillary sinusitis cases were associated with a dental origin, and sinus lift procedures were the main aetiological factor. Our microbiological findings showed that all specimens from chronic maxillary sinusitis were polymicrobial. Sixty aerobes and 75 anaerobes were recovered from the 47 cases of non-odontogenic sinusitis (2.9 bacteria per specimen); 15 aerobes and 25 anaerobes were isolated from the 12 patients with odontogenic sinusitis (3.3 bacteria per specimen). The predominant aerobes were Staphylococcus aureus (27) and Streptococcus pneumoniae (16), while the more frequent anaerobes were Peptostreptococcus species (31) and Prevotella species (30). Haemophilus influenzae and Moraxella catarrhalis were absent in sinusitis associated with a dental origin. Overall, 22 % of Staphylococcus aureus isolates were oxacillin-resistant, and 75 % of Streptococcus pneumoniae isolates were penicillin-resistant and/or erythromycin-resistant; 21 % of anaerobic Gram-positive bacteria were penicillin-resistant, and 44 % of anaerobic Gram-negative bacteria were ß-lactamase-positive. Vancomycin and quinopristin-dalfopristin had the highest in vitro activity against Staphylococcus aureus and Streptococcus species, respectively; amoxicillin-clavulanate and cefotaxime showed the highest in vitro activity against aerobic Gram-negative bacteria; and moxifloxacin, metronidazole and clindamycin were the most active against anaerobic bacteria.

Probiotics: overview of microbiological and immunological characteristics.

Over the last few years, probiotics (commercialized as food, dietary supplements of living bacteria or pharmaceuticals) have attracted the interest of scientists as well as consumers. Recent public interest in healthier lifestyles, together with the acceptance by physicians of nonmainstream therapies, has refocused attention on the role of human microbiota in the prevention and therapy of diseases. Modulation of the intestinal microbiota may be achieved by consuming living bacteria or by consuming a combination of probiotics and prebiotics. In addition, we are learning more about the biology of probiotic microorganisms, through sequencing their genomes, and the interactions of probiotics with human cells and with pathogenic bacteria. Results from well-conducted clinical studies help to increase the acceptance of probiotics for the treatment and prevention of selected diseases, both inside and outside the GI tract. Moreover, the use of selected probiotics for particular subject groups may provide more specific health effects. The medical profession is in an ideal position to guide the consumer towards appropriate prophylactic or therapeutic uses of probiotics in health or in specific disease states.