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Characterization of oral lactobacilli as potential probiotics for oral health

INTRODUCTION Intestinal lactobacilli have been successfully used as probiotics to treat gastrointestinal disorders, but only limited data are available for the probiotic properties of oral lactobacilli to combat oral diseases. We aimed to characterize oral lactobacilli for their potential probiotic properties according to the international guidelines for the evaluation of probiotics, and to select potential probiotic strains for oral health. METHODS The study included 67 salivary and subgingival lactobacilli of 10 species, isolated from healthy humans. All strains were identified using amplified ribosomal DNA restriction analysis, tested for antimicrobial activity against oral pathogens, tolerance of low pH and bile content. Thereafter, the lysozyme tolerance and antibiotic susceptibility of 22 potential probiotic strains were assessed. RESULTS The majority of strains suppressed the growth of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, and Streptococcus mutans, but none inhibited Candida albicans. The lowest pH tolerated by lactobacilli following 4 h of incubation was pH 2.5, but none of the strains grew at this pH. All strains tolerated a high concentration of lysozyme (10 mg/ml) and half of the strains tolerated a high concentration of human bile [5% volume/volume (V/V)]. Four Lactobacillus plantarum and two Lactobacillus oris strains expressed resistance to tetracycline and/or doxycycline. CONCLUSIONS Strains of L. plantarum, Lactobacillus paracasei, Lactobacillus salivarius, and Lactobacillus rhamnosus expressed both high antimicrobial activity and high tolerance of environmental stress. The absence of transferable antibiotic-resistance genes in L. plantarum strains remains to be confirmed. These results suggest a potential for oral lactobacilli to be used as probiotics for oral health.

The limit of leucocytospermia from the microbiological viewpoint

Summary.  The aim of the study was to find out the correlation between white blood cell (WBC) counts in semen and quantitative composition of seminal microflora, and to establish the minimum WBC count associated with significant bacteriospermia. The research included 159 men with different WBC counts in their semen, 84 of them with chronic prostatitis/chronic pelvic pain syndrome. Semen samples were cultivated quantitatively for detecting anaerobic, microaerophilic and aerobic bacteria. Bryan‐Leishman stained slides were used for detecting WBC in semen. Seminal fluid was colonized by eight different microorganisms, and the total count of microorganisms in semen ranged from 102 to 107 CFU ml−1. A high frequency of anaerobic microorganisms was found. A positive correlation was observed between the WBC count and the number of different microorganisms, and also between the WBC count and the total count of microorganisms in semen sample. The receiver operating characteristic curve analysis demonstrated that the WHO‐defined WBC cut‐off point (1 × 106 WBC ml−1) has very low sensitivity for discriminating between patients with and without significant bacteriospermia, as a more optimal sensitivity/specificity ratio appears at 0.2 × 106 WBC ml−1 of semen. The quantitative microbiological finding of semen in the patients of National Institute of Health (NIH) categories IIIa and IV was very similar, i.e. a high number of different microorganisms and a high total count of microorganisms. In the control group (without leucocytospermia and prostatitis symptoms) both parameters were significantly lower.

Mycoplasmas in semen of chronic prostatitis patients

Objective. To evaluate the occurrence of mycoplasmas in the semen of chronic prostatitis patients. Material and methods. Genital mycoplasmas (Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum, Ureaplasma parvum) were sought in the semen of 121 chronic prostatitis patients [38 National Institutes of Health (NIH) category IIIa, 59 NIH category IIIb and 24 NIH category IV] and 40 controls. The commercially available kit Mycoplasma IST was applied to the semen samples of all 161 men, and polymerase chain reaction (PCR) to those of 60 randomly selected men. Results. Ureaplasmas were found in all study groups (at frequencies ranging from 12% to 25%) using the Mycoplasma IST test, but M. hominis was found only in one NIH category IIIb patient. Using PCR, most of the ureaplasmas appeared to be U. parvum, which was found in all prostatitis groups (18% of NIH category IIIa, 15% of NIH category IIIb and 25% of NIH category IV patients) but not in the controls. M. genitalium was found in 18% of the NIH category IIIa patients. All of the mycoplasmas occurred significantly more frequently in prostatitis patients than in controls and in NIH category IIIa patients than in controls. Conclusion. Mycoplasmas occur more frequently in the semen of prostatitis patients than in that of healthy controls, with U. parvum being the most frequently occurring species.

Oxidative Stress—Cause or consequence of male genital tract disorders?

Inflammatory prostatitis patients are characterized by oxidative stress (OxS) at local and systemic levels. Less is known about the occurrence of OxS in the case of other frequent male genital tract disorders.

Expression of single-chain antibody against RgpA protease of Porphyromonas gingivalis in Lactobacillus

Aims:  The monoclonal antibody 61BG1·3, recognizing the RgpA protease, has been reported to confer protection against recolonization by the periodontal pathogen Porphyromonas gingivalis in humans. The aim of this study was to express a functional scFv derived from the monoclonal antibody 61BG1·3 on the surface of Lactobacillus paracasei for potential use in the prevention or treatment of periodontal diseases.

Oxidative stress in leucocytospermic prostatitis patients: preliminary results

The aim of this study was to contribute to the knowledge concerning pathogenesis of inflammatory chronic prostatitis by revealing possible shifts in the balance of markers of oxidative stress and anti‐oxidative activity in case of leucocytospermic prostatitis. We also attempted to identify possible relations between seminal micro‐organisms and oxidative stress parameters. A many‐sided complex of local (spermatozoa, seminal plasma) and general (blood, urine) markers in 21 prostatitis patients and nine controls was compared. In both spermatozoa and seminal plasma, the content of diene conjugates was significantly higher in prostatitis patients compared with healthy controls. At the same time total anti‐oxidative status in spermatozoa and total anti‐oxidative activity in seminal plasma were lower in prostatitis patients than in controls. In urine, the level of 8‐isoprostanes was significantly higher in prostatitis patients than in healthy controls, correlating well with 8‐hydroxy‐2′‐deoxyguanosine. The latter correlated with cellular Fe and Ni contents as well, confirming that these metals with varying valency may cause DNA damage. Reduced glutathione showed higher levels in blood of controls than in prostatitis patients. Coryneform bacteria appeared to be associated with prostatitis‐related oxidative stress. In conclusion, leucocytospermic prostatitis patients are characterised by oxidative stress at all levels: systemic (general), seminal plasma and cellular.

Antibacterial Susceptibility of Intestinal Lactobacilli of Healthy Children

We investigated the antibacterial susceptibility of intestinal lactobacilli of Estonian and Swedish children aged 1-2 y. Sixty isolates (10 species) of lactobacilli (29 Estonian and 31 Swedish strains) were tested against ampicillin, cefuroxime, cefoxitin, gentamicin, ciprofloxacin, tetracycline, vancomycin, metronidazole and erythromycin. We observed that intestinal lactobacilli do not display uniform susceptibility to antibiotics. None of the tested lactobacilli was resistant to ampicillin, gentamicin and erythromycin. Single strains were resistant to cefuroxime and tetracycline, about half of the strains to cefoxitin and ciprofloxacin and 73% of the strains to vancomycin. All studied strains were resistant to metronidazole. Most of the strains investigated were resistant to two or three antibiotics out of nine. Some differences in susceptibility were noted between strains belonging to different fermentation types. No differences in susceptibility were found between Estonian and Swedish isolates. Metronidazole, cefoxitin, vancomycin and ciprofloxacin seem to be safer for gastrointestinal lactoflora than other tested antibiotics in both countries.We investigated the antibacterial susceptibility of intestinal lactobacilli of Estonian and Swedish children aged 1?2 y. Sixty isolates (10 species) of lactobacilli (29 Estonian and 31 Swedish strains) were tested against ampicillin, cefuroxime, cefoxitin, gentamicin, ciprofloxacin, tetracycline, vancomycin, metronidazole and erythromycin. We observed that intestinal lactobacilli do not display uniform susceptibility to antibiotics. None of the tested lactobacilli was resistant to ampicillin, gentamicin and erythromycin. Single strains were resistant to cefuroxime and tetracycline, about half of the strains to cefoxitin and ciprofloxacin and 73% of the strains to vancomycin. All studied strains were resistant to metronidazole. Most of the strains investigated were resistant to two or three antibiotics out of nine. Some differences in susceptibility were noted between strains belonging to different fermentation types. No differences in susceptibility were found between Estonian and Swedish isolates. Metronidazole, cefoxitin, vancomycin and ciprofloxacin seem to be safer for gastrointestinal lactoflora than other tested antibiotics in both countries.

Prevalence of asymptomatic inflammatory (National Institutes of Health Category IV) prostatitis in young men according to semen analysis.

OBJECTIVES To determine the prevalence of asymptomatic inflammatory (National Institutes of Health category IV) prostatitis in a cross-sectional community sample of young men. METHODS The study group consisted of 565 men aged 18.9 +/- 1.8 years (mean +/- standard deviation). Cytologic examination of all ejaculates (using Bryan-Leishman stained slides), as well as analysis for basic semen parameters (volume, concentration, and motility) and clinical examination for possible pathologies in the genital region, were performed. Subjects with any clinical symptoms of inflammation were excluded. Levels of prostate-specific antigen in blood serum and interleukin-6 in seminal plasma were determined as well. RESULTS The prevalence of asymptomatic inflammatory prostatitis (greater than 1 x 10(6) white blood cells [WBC]/mL in semen, according to World Health Organization guidelines) was 6.0%, but when we used a lower threshold suggested by our previous studies (greater than 0.2 x 10(6) WBC/mL), the prevalence was 19.0%. In this study the analysis did not show any significant effect of leukocytospermia on sperm quality, except higher sperm concentration in subjects with moderate leukocytospermia (0.2-1 x 10(6) WBC/mL). We did not detect any seasonal differences in the prevalence of asymptomatic inflammatory prostatitis. Interleukin-6 and prostate-specific antigen levels were significantly higher in leukocytospermic subjects than in those without leukocytospermia. CONCLUSIONS Asymptomatic inflammatory prostatitis has a notable prevalence among healthy young men, suggesting the need for further studies to investigate pathogenetic mechanisms of the disease. Lack of negative effect of leukocytospermia on basic semen parameters may indicate higher functional reserve of accessory sex glands in this age group.

Male infertility: Decreased levels of selenium, zinc and antioxidants

In this study, we aimed to compare the level of zinc, selenium, glutathione peroxidase activity and antioxidant status in following populations of men: severe inflammation in prostate (>10(6) white blood cells in prostate secretion; n=29), severe leukocytospermia, (>10(6) white blood cells in semen; n=31), mild inflammation, (0.2-1M white blood cells in semen or prostate secretion; n=24), non-inflammatory oligozoospermia (n=32) and healthy controls (n=27). Male partners of infertile couples had reduced level of antioxidative activity, selenium and zinc in their seminal plasma. Most importantly, reduced selenium levels were evident in all patient groups regardless of inflammation status. Therefore, these patients might gain some benefit from selenium supplementation.

Complementary seminovaginal microbiome in couples

The genital tract microbiome is tightly associated with reproductive health. Although many research studies have been performed on the vaginal microbiome, current knowledge of the male microbiome is scarce, and parallel studies examining couples are extremely rare. In this work, we aimed to compare seminal and vaginal microbiomes in couples and to assess the influence of sexual intercourse on vaginal microbiome. The study included 23 couples. Microbiomes of semen and vaginal fluid (pre- and post-intercourse) were profiled using Illumina HiSeq2000 sequencing of the V6 region of 16S rRNA gene. Seminal communities were significantly more diverse, but with lower total bacterial concentrations than those of the vagina. Gardnerella vaginalis was predominant in half of the women whose partners had significant leukocytospermia, but only in one of 17 women who had a partner without leukocytospermia. There was significant decrease in the relative abundance of Lactobacillus crispatus after intercourse, and high concordance between semen and vaginal samples. Our data support the hypothesis that semen and vaginal microbiomes are in association, inasmuch as the predominance of G. vaginalis in female partners was significantly related to inflammation in male genital tracts.