Evaluation of Lactobacilli for Antagonistic Activity Against the Growth, Adhesion and Invasion of Klebsiella pneumoniae and Gardnerella vaginalis.

Urinary tract infections are the most common infectious diseases in babies and the elderly and are often acquired as nosocomial infections. The purpose of the present study was to identify strains of lactic acid bacteria (LAB) which could be used as alternatives to antibiotics for the treatment of urinary tract infections because of their ability to inhibit urinary tract pathogens (Klebsiella pneumoniae BCRC 10694 and Gardnerella vaginalis BCRC 17040). We screened 370 LAB strains using spent culture supernatants by inhibition zone assay to assess their antimicrobial effects. We studied the effect of heat, pH and enzyme treatment on the inhibitory activity of LAB strain supernatants. Anti-growth activity against urinary tract pathogens was evaluated by co-culture inhibition assay using seven LAB strains. Anti-adhesion and anti-invasion activities against urinary tract pathogens were evaluated by SV-HUC-1 uroepithelium cell culture. The results showed that the supernatants had good heat stability. However, antibacterial activity disappeared entirely at pH 7.0. After enzyme treatments, the supernatants showed first- or second-order inhibitory effects on K. pneumonia BCRC 10694. The survival rate of urinary tract pathogens was 0-10.65% and pH of the culture medium decreased after co-culture with LAB strains for 4 h. In a competition assay, PM2 and RY2 inhibited urinary tract pathogens. PM68, PM78, PM201, PM206 and PM229 inhibited the invasion of SV-HUC-1 cells by G. vaginalis BCRC17040. In conclusion, PM78, PM229 and RY2 showed the strongest inhibitory activity against urinary tract pathogens and could be suitable for use in the treatment of urinary tract infections.

Multispecies probiotics combination prevents ovalbumin-induced airway hyperreactivity in mice.

BACKGROUND: Probiotics could be beneficial to health and some of them have shown to modulate immune responses. AIM: The aim of this study is to investigate if the probiotic strains including Lactobacillus and Pediococcus strains are able to alleviate allergic reactions in an ovalbumin-induced airway allergy model. METHODS: Lactobacillus multi-species preparation (LMP) was gavaged to BALB/c for total six weeks and BALB/c was challenged with ovalbumin in the last two weeks. A barometric whole-body plethysmography was used to assess enhanced pause (Penh) of airway hyperreactivity (AHR). Immunoglobulins (Ig) such as IgE, IgG1, IgG2a and cytokines such as IL-12, IFN-γ, IL-4, IL-5, TNF-α and IL-13 in bronchoalveolar lavage fluid were assayed using ELISA kits. RESULTS: The results showed this LMP significantly reduced Th2 cytokines and enhanced Th1 cytokines production. OVA-specific IgE and IgG1 was lower in the probiotics-treated mice whereas IgG2a was increased. Most importantly, this murine model showed LMP supplementation significantly reduced AHR. CONCLUSIONS: Overall, this Lactobacillus multi-species preparation seemed to suppress OVA-sensitized airway hyperreactivity, thus serving as a possible candidate for therapeutic uses for allergic airway symptoms.

Evaluation of Lactic Acid Bacteria on the Inhibition of Vibrio parahaemolyticus Infection and Its Application to Food Systems.

This study tested the effect of lactic acid bacteria (LAB) inhibition on Vibrio parahaemolyticus BCRC (Bioresource Collection and Research Center) 10806 and BCRC 12865 in a food model. MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays indicated that Caco-2 cells were not damaged after a two-hour treatment with lactic acid bacteria (LAB) and V. parahaemolyticus. The LAB cell culture and supernatant effectively inhibited the growth of V. parahaemolyticus in a food model. ELISA (Enzyme-linked immunosorbent assay) results indicated the significant inhibition of TNF-α; IL-1ß; and IL-6; but Lactobacillus plantarum PM 222 and L. plantarum LP 735 did not significantly affect IL-8 levels. Real-time polymerase chain reaction (PCR) results indicated that LAB could inhibit the mRNA expression of proinflammatory cytokines IL-8; IL-6; and TNF-α; which were induced by V. parahaemolyticus. After rat-received LAB; the expression levels of TNF-α; IL-6; and IL-8 in the serum decreased significantly. In intestinal histology; the rat that received L. plantarum PM 222 and L. plantarum LP 010 was able to alleviate the intestinal villi damage caused by V. parahaemolyticus; which also helped reduce cell apoptosis. In conclusion; our results indicate that LAB can inhibit inflammatory responses caused by V. parahaemolyticus and can effectively inhibit the growth of V. parahaemolyticus in food products.

Isolation and Characterisation of Probiotics for Antagonising the Cariogenic Bacterium Streptococcus mutans and Preventing Biofilm Formation.

PURPOSE: Consumption of refined foods and beverages high in sugar make the teeth susceptible to the formation of biofilm and may lead to dental caries. The aim of the present study was to determine the ability of selected probiotics to inhibit growth and biofilm formation by the cariogenic bacterium Streptococcus mutans in vitro. MATERIALS AND METHODS: Strains of latic acid bacteria (LAB) (n = 120) from the Bioresources Collection and Research Center (BCRC), saliva of healthy adults and infant stool were screened. The antimicrobial activity of LAB in vitro was evaluated by agar spot culture and co-culture of the S. mutans strains. Antagonistic substances in the spent culture suspensions (SCS) of LAB were precipitated by extraction with ammonium sulphate and chloroform to characterise the protein and lipophilic fractions. RESULTS: Results of co-culturing show that the SCS of the three LAB strains (Lactobacillus pentosus 13-1, 13-4 and L. crispatus BCRC 14618) subjected to heat treatment showed statistically significantly higher antimicrobial activity. Substances produced by L. pentosus 13-4 which have the potential to exhibit antimicrobial properties might be lipophilic proteins. Additionally, microtiter plate biofilm assays indicated that in vitro biofilm formation by S. mutans is strongly modulated by L. pentosus 13-4 and L. crispatus BCRC 14618. CONCLUSION: It can be inferred that the mechanism of reducing biofilm formation by these two LAB strains is associated with sucrose-dependent cell-cell adhesion and the gtfC level of glucosyltransferases in the biofilm. Therefore, it is suggested that L. pentosus 13-4 and L. crispatus BCRC 14618 may contribute to preventing dental caries, as they showed an inhibitory effect on the growth and biofilm formation of the cariogenic bacterium S. mutans in vitro.

Inhibitory Effects of Probiotic Lactobacillus on the Growth of Human Colonic Carcinoma Cell Line HT-29.

This study was conducted to investigate the inhibitory effect of Lactobacillus cells and supernatants on the growth of the human colon cancer cell line HT-29. Our study results indicated that the PM153 strain exhibits the best adhesion ability and the highest survival in the gastrointestinal tract simulation experiment. Furthermore, after an 8-h co-culture of PM153 and HT-29 cells, the PM153 strain can induce the secretion of nitric oxide from the HT-29 cells. In addition, after the co-culture of the BCRC17010 strain (108 cfu/mL) and HT-29 cells, the Bax/Bcl-2 ratio in the HT-29 cells was 1.19, which showed a significant difference from the other control and LAB groups (p < 0.05), which therefore led to the inference that the BCRC17010 strain exerts a pro-apoptotic effect on the HT-29 cells. Upon co-culture with HT-29 cells for 4, 8 and 12 h, the BCRC14625 strain (108 cfu/mL) demonstrated a significant increase in lactate dehydrogenase (LDH) activity (p < 0.05), causing harm to the HT-29 cell membrane; further, after an 8-h co-culture with the HT-29 cells, it induced the secretion of nitric oxide (NO) from the HT-29 cells. Some lactic acid bacteria (LAB) strains have ability to inhibit the growth of the colorectal cancer cell line HT-29 Bax/Bcl-2 pathway or NO production. In summary, we demonstrated that the BCRC17010 strain, good abilities of adhesion and increased LDH release, was the best probiotic potential for inhibition of HT-29 growth amongst the seven LAB strains tested in vitro.

Multi-Strain Probiotics Inhibit Cardiac Myopathies and Autophagy to Prevent Heart Injury in High-Fat Diet-Fed Rats.

High-fat diets induce obesity, leading to cardiomyocyte fibrosis and autophagy imbalance. In addition, no previous studies have indicated that probiotics have potential health effects associated with cardiac fibrosis and autophagy in obese rats. This study investigates the effects of probiotics on high-fat (HF) diet-induced obesity and cardiac fibrosis and autophagy in rat hearts. Eight-week-old male Wistar rats were separated randomly into five equally sized experimental groups: Normal diet (control) and high-fat (HF) diet groups and groups fed a high-fat diet supplemented with low (HL), medium (HM) or high (HH) doses of multi-strain probiotic powders. These experiments were designed for an 8-week trial period. The myocardial architecture of the left ventricle was evaluated using Masson's trichrome staining and immunohistochemistry staining. Key probiotics-related pathway molecules were analyzed using western blotting. Abnormal myocardial architecture and enlarged interstitial spaces were observed in HF hearts. These interstitial spaces were significantly decreased in groups provided with multi-strain probiotics compared with HF hearts. Western blot analysis demonstrated that key components of the TGF/MMP2/MMP9 fibrosis pathways and ERK5/uPA/ANP cardiac hypertrophy pathways were significantly suppressed in probiotic groups compared to the HF group. Autophagy balance is very important in cardiomyocytes. In this study, we observed that the beclin-1/LC3B/Atg7 autophagy pathway in HF was increased after probiotic supplementation was significantly decreased. Together, these results suggest that oral administration of probiotics may attenuate cardiomyocyte fibrosis and cardiac hypertrophy and the autophagy-signaling pathway in obese rats.

Heat-Killed Lactobacillus salivarius and Lactobacillus johnsonii Reduce Liver Injury Induced by Alcohol In Vitro and In Vivo.

The aim of the present study was to determine whether Lactobacillus salivarius (LS) and Lactobacillus johnsonii (LJ) prevent alcoholic liver damage in HepG2 cells and rat models of acute alcohol exposure. In this study, heat-killed LS and LJ were screened from 50 Lactobacillus strains induced by 100 mM alcohol in HepG2 cells. The severity of alcoholic liver injury was determined by measuring the levels of aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyl transferase (γ-GT), lipid peroxidation, triglyceride (TG) and total cholesterol. Our results indicated that heat-killed LS and LJ reduced AST, ALT, γ-GT and malondialdehyde (MDA) levels and outperformed other bacterial strains in cell line studies. We further evaluated these findings by administering these strains to rats. Only LS was able to reduce serum AST levels, which it did by 26.2%. In addition LS significantly inhibited serum TG levels by 39.2%. However, both strains were unable to inhibit ALT levels. In summary, we demonstrated that heat-killed LS and LJ possess hepatoprotective properties induced by alcohol both in vitro and in vivo.

Safety evaluation of multiple strains of Lactobacillus plantarum and Pediococcus pentosaceus in Wistar rats based on the Ames test and a 28-day feeding study.

Three lactic acid bacterial strains, Lactobacillus plantarum, HK006, and HK109, and Pediococcus pentosaceus PP31 exhibit probiotic potential as antiallergy agents, both in vitro and in vivo. However, the safety of these new strains requires evaluation when isolated from infant faeces or pickled cabbage. Multiple strains (HK006, HK109, and PP31) were subject to a bacterial reverse mutation assay and a short-term oral toxicity study. The powder product exhibited mutagenic potential in Salmonella Typhimurium strains TA98 and TA1535 (with or without metabolic activation). In the short-term oral toxicity study, rats received a normal dosage of 390 mg/kg/d (approximately 9 × 10(9) CFU/kg/d) or a high dosage of 1950 mg/kg/d (approximately 4.5 × 10(10) CFU/kg/d) for 28 d. No adverse effects were observed regarding the general condition, behaviour, growth, feed and water consumption, haematology, clinical chemistry indices, organ weights, or histopathologic analysis of the rats. These studies have demonstrated that the consumption of multiple bacterial strains is not associated with any signs of mutagenicity of S. Typhimurium or toxicity in Wistar rats, even after consuming large quantities of bacteria.

Cholesterol-lowering potentials of lactic acid bacteria based on bile-salt hydrolase activity and effect of potent strains on cholesterol metabolism in vitro and in vivo.

This study collected different probiotic isolates from animal and plant sources to evaluate the bile-salt hydrolase activity of probiotics in vitro. The deconjugation potential of bile acid was determined using high-performance liquid chromatography. HepG2 cells were cultured with probiotic strains with high BSH activity. The triglyceride (TG) and apolipoprotein B (apo B) secretion by HepG2 cells were evaluated. Our results show that the BSH activity and bile-acid deconjugation abilities of Pediococcus acidilactici NBHK002, Bifidobacterium adolescentis NBHK006, Lactobacillus rhamnosus NBHK007, and Lactobacillus acidophilus NBHK008 were higher than those of the other probiotic strains. The cholesterol concentration in cholesterol micelles was reduced within 24 h. NBHK007 reduced the TG secretion by 100% after 48 h of incubation. NBHK002, NBHK006, and NBHK007 could reduce apo B secretion by 33%, 38%, and 39%, respectively, after 24 h of incubation. The product PROBIO S-23 produced a greater decrease in the total concentration of cholesterol, low-density lipoprotein, TG, and thiobarbituric acid reactive substance in the serum or livers of hamsters with hypercholesterolemia compared with that of hamsters fed with a high-fat and high-cholesterol diet. These results show that the three probiotic strains of lactic acid bacteria are better candidates for reducing the risk of cardiovascular disease.

Suppression of TLR-4-related inflammatory pathway and anti-fibrosis effects of probiotic-fermented purple sweet potato yogurt in hearts of spontaneously hypertensive rats.

Inflammation plays an important role in triggering fibrosis of cardiovascular disease and hypertension. Gamma-aminobutyric acid (GABA) has hypotensive effect; GABA concentration could be enhanced in milk fermented with lactic acid bacteria (LAB). This study evaluated the effect of probiotic-fermented purple sweet potato yogurt (PSPY) on the toll-like receptor 4 (TLR-4)-related inflammatory components, and on fibrosis in the heart of spontaneously hypertensive rat (SHR). TLR4-related pathway and fibrosis-associated proteins TGFbeta and FGF2 were significantly increased in SHR hearts, but were highly suppressed in 10% PSPY-fed rats. Microscopic examination with Masson trichrome staining of left ventricle further demonstrated that 10% and 100% PSPY both significantly reduced interstitial fibrosis in SHR hearts. These findings indicated that oral administration of 10% probiotic-fermented PSPY was strong enough to lower cardiac fibrosis in SHR rats through the suppression of TLR-4-related inflammatory pathway. Therefore, PSPY may be included in diets to help prevent cardiac fibrosis in patients with hypertension.

Genotoxicity assessment of multispecies probiotics using reverse mutation, mammalian chromosomal aberration, and rodent micronucleus tests.

Genotoxicity assessment is carried out on freeze dried powder of cultured probiotics containing Lactobacillus rhamnosus LCR177, Bifidobacterium adolescentis BA286, and Pediococcus acidilactici PA318. Ames tests, in vitro mammalian chromosome aberration assay, and micronucleus tests in mouse peripheral blood are performed. For 5 strains of Salmonella Typhimurium, the Ames tests show no increased reverse mutation upon exposure to the test substance. In CHO cells, the frequency of chromosome aberration does not increase in responding to the treatment of probiotics. Likewise, the frequency of micronucleated reticulocytes in probiotics-fed mice is indistinguishable from that in the negative control group. Taken together, the toxicity assessment studies suggest that the multispecies probiotic mixture does not have mutagenic effects on various organisms.

Applications of Lactobacillus rhamnosus spent culture supernatant in cosmetic antioxidation, whitening and moisture retention applications.

This study was aimed at investigating the antioxidant, whitening, and moisture-retention properties of Lactobacillus rhamnosus spent culture supernatant (Lr-SCS) in cosmetic applications. Results reveal that Lr-SCS effectively and gradually scavenges 1,1-diphenyl-2-picrylhydrazyl as well as 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cations, and increases reducing power in a dose-dependent manner. Additionally, Lr-SCS can also suppress tyrosinase activity in vitro and effectively promote moisture retention. Heat treatment at 100 °C for 30 min does not influence the functions of Lr-SCS. We conclude that Lr-SCS can be used effectively in skin care cosmetics.

Assessing the Effectiveness of Fermented Banana Peel Extracts for the Biosorption and Removal of Cadmium to Mitigate Inflammation and Oxidative Stress.

This study identified 11 lactic acid bacteria (LAB) strains that exhibited tolerance to heavy metal cadmium concentrations above 50 ppm for 48 h. Among these strains, T126-1 and T40-1 displayed the highest tolerance, enduring cadmium concentrations up to 500 ppm while still inhibiting bacterial growth by 50%. Moreover, the fermentation of banana peel using LAB significantly enhanced the clearance rate of cadmium (p < 0.05) compared to nonfermented banana peel. Additionally, the LAB-fermented banana peel exhibited higher 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and reduced power values. Strain T40-1 exhibited a significant improvement in its ability to chelate ferrous ions (p < 0.05). Regarding antibiotic resistance, both the T40-1 and TH3 strains demonstrated high resistance with a third-level inhibition rate against ampicillin and tetracycline. Cell viability tests revealed that incubation with the T40-1 and TH3 strains for a duration of 24 h did not result in any cellular damage. Moreover, these LAB strains effectively mitigated oxidative stress markers, such as reactive oxygen species (ROS), glutathione (GSH), and lactate dehydrogenase (LDH), caused by 2 ppm cadmium on cells. Furthermore, the LAB strains were able to reduce the inflammatory response, as evidenced by a decrease in interleukin-8 (IL-8) levels (p < 0.05). The use of Fourier transform infrared (FT-IR) spectroscopy analysis provided valuable insight into the interaction between metal ions and the organic functional groups present on the cell wall of fermented banana peel. In summary, this study highlights the potential of the LAB strains T40-1 and TH3 in terms of their tolerance to the cadmium, ability to enhance cadmium clearance rates, and their beneficial effects on oxidative stress, inflammation, and cell viability.

Investigating the Effectiveness of Exopolysaccharide-Producing Lactic Acid Bacteria in Biosorbing Lead (II), Attaching to Caco-2 Cells, and Provoking Antiinflammatory Responses.

Lead is a common toxic heavy metal with harmful effects on the human body and is widely used in several industries. It can contaminate the environment by air and water emissions and can enter the human body through the respiratory tract, ingestion, or skin contact. Lead is considered as a persistent environmental pollutant, with a half-life of 30 days in the blood, and exists in the skeletal system for decades and causes damage to other systems. Biosorption is receiving increasing attention. Due to its high efficiency and economic value in removing heavy metals from the environment, a variety of biosorption methods can be used for the removal of heavy metals. Lactic acid bacteria (LAB) strains were capable of attaching to both human skin stratum corneum HaCaT cells and human rectal cancer Caco-2 cells. NBM-04-10-001 and NBM-01-07-003 significantly reduced the secretion of IL-6 and IL-8 after coculture with HaCaT cells. In the immune response of RAW264.7 mouse macrophages, high bacterial counts reduced the concentrations of IL-6 and TNF-α in a dose-dependent manner. The results of animal experiments revealed that feeding lead solution exerted no effect on the animal's food intake, and feeding PURE LAC NBM11 powder could effectively remove lead content in the blood. The group fed with PURE LAC NBM11 powder showed significantly less damage and lesions to liver cells. The LAB powder developed in this study has the potential to bind metals, preventing them from entering the body and protecting the host. LAB can be an ideal strain for future bioadsorption chelators.

Anti-inflammatory effects of probiotic Lactobacillus paracasi on ventricles of BALB/C mice treated with ovalbumin.

Lactic acid bacteria (LAB) are microorganisms that benefit animals with allergic diseases and intestinal disorders such as inflammatory bowel disease. We propose that LAB can prevent cardiomyocytes inflammation and apoptosis in BALB/c mice using an ovalbumin (OVA)-induced allergy. Thirty-nine male BALB/c mice were divided into five groups: normal control, allergy control and three allergy groups each treated with Kefir I (Kefir I), Kefir II (Kefir II) or GM080 products (GM080). The myocardial architecture and apoptotic molecules in the excised left ventricle from these mice were investigated and post-treatment effects were evaluated. The inflammatory pathway, including toll-like receptor 4 (TLR4), phospholate-Jun-N-terminal kinase (p-JNK), JNK1/2 and tumor necrosis factor- alpha (TNF-α) and the mitochondria-dependent apoptosis phospholate-p38 (p-p38), Bcl-2 associated agonist of cell death (Bad), Bcl-2 associated X (Bax) and activated caspase 3, were found to be significant- ly increased in the hearts of allergy mice. The expression of phospholate-nuclear factor-κB (p-NFκB), TNF-α, p-p38 and Bad protein products were reduced or retarded in the Kefir I- or II-treated allergy group. The GM080-treated allergy group exhibited significantly lower p-JNK, JNK1/2, phospholate- Ikappa B (p-IκB), Bax and Bad protein products than the Kefir I and Kefir II allergy groups. These results indicate that LAB can reduce inflammation and prevent apoptosis of cardiomyocytes in the heart of OVA-induced allergy mice.

High-Grade B-Cell Lymphoma (HGBL) with MYC and BCL2 and/or BCL6 Rearrangements Is Predominantly BCL6-Rearranged and BCL6-Expressing in Taiwan.

This study investigated the epidemiological and clinical peculiarities of BCL2 and BCL6 rearrangement in patients with high grade B-cell lymphoma (HGBL) from Taiwan, compared with data from Western countries. Two hundred and eighty-two DLBCL cases from Taipei Medical University-affiliated hospitals (n = 179) and Tri-Service General Hospital (n = 103) were enrolled for this study. From the 282, 47 (16.7%) had MYC translocation; 24 of these harbored concurrent BCL2 and/or BCL6 translocation (double-hit, DH or triple-hit, TH). Twelve DH-HGBL cases had simultaneous MYC and BCL6 translocations, 8 harbored MYC and BCL2 rearrangement, while the remaining 4 patients exhibited TH. Together, 66.7% of DH/TH-HGBL patients were BCL6 rearrangement positive. Among these BCL6-rearranged DH/TH-HGBL patients, only 6 (37.5%) overexpressed MYC and BCL6 proteins simultaneously, indicating that MYC-BCL6 co-overexpression may not be plausible surrogate biomarker for screening BCL6-rearranged DH-HGBL. By the end of year 5, all patients with TH-HGBL, BCL2 DH-HGBL and all but one BCL6 DH-HGBL cases had expired or were lost to follow-up. Progression-free survival (PFS) was longer for the non-DH/TH-HGBL group compared with the DH/TH-HGBL group. While the patients with BCL2 DH-HGBL were lost to follow-up by day 800, their remaining TH-HGBL and BCL6 DH-HGBL peers exhibited very poor PFS, regardless of age strata. More so, patients with BCL6 rearrangement were 5.5-fold more likely associated with extranodal involvement compared with their BCL2-rearranged peers. Moreover, ~60.0% of the BCL6-rearranged DH-HGBL cases were non-GCB, suggesting that including screening for BCL6 rearrangement in patients with the non-GCB phenotype may aid medical decision-making and therapeutic strategy. Contrary to contemporary data from western countries, 2 in every 3 patients with DH/TH-HGBL in Taiwan harbor BCL6 rearrangement. Consistent with present findings, we recommend mandatory screening for BCL6 rearrangement in patients with aggressive HGBL in Taiwan.

Use of PCR primers and probes based on the 23S rRNA and internal transcription spacer (ITS) gene sequence for the detection and enumerization of Lactobacillus acidophilus and Lactobacillus plantarum in feed supplements.

Novel polymerase chain reaction (PCR) primers designed from the 16S-23S internal transcription spacer (ITS) rRNA and 23S rRNA genes, respectively, were used for the specific detection of Lactobacillus acidophilus and Lactobacillus plantarum. Molecular weights of the PCR products were 221 and 599 bp, respectively. Strains of L. acidophilus and L. plantarum obtained from the culture center, dairy products, infant stool and other samples, could be identified with these PCR primers. DNAs from other lactic acid bacteria (LAB) species including strains of Lactobacillus pentosus which was closely related to L. plantarum, and bacteria species other than LAB, would not generate the false positive results. When this PCR primer set was used for the detection of L. acidophilus and L. plantarum in feed supplement or feed starter samples, reliable results were obtained. Furthermore, when these L. acidophilus or L. plantarum specific primers were used as DNA probes for the colony hybridization of L. acidophilus and L. plantarum, the viable cells of these LAB species in culture and feed supplements or starter products could be identified and enumerized. The method described here thus offers a rapid and economic way to inspect and assure the quality of the feed supplements or fermentation starters.

Evaluation of inhibitory activity of domestic probiotics for against invasion and infection by Proteus mirabilis in the urinary tract.

INTRODUCTION: Approximately 5% of men and 40%-50% of women have experienced urinary tract infections (UTI), which are the most common infectious diseases and nosocomial infections in humans. Proteus mirabilis is susceptible to most antibiotics, but antibiotic treatment usually causes side effects. In this research, lactic acid bacteria (LAB) was assessed for its inhibitory activity against a urinary tract pathogen. METHODOLOGY: We studied the effect of pH adjustment, heat, and enzyme treatments on the inhibitory activity of LAB strains and their supernatants, using well-diffusion and co-culture assays. In the cell culture assay, anti-adhesion and anti-invasion activities against P. mirabilis were tested with SV-HUC-1 urothelial cells. RESULTS: LAB were able to adhere to the urothelial cells and inhibited P. mirabilis growth. LAB were also able to inhibit P. mirabilis adhesion to or invasion of SV-HUC-1 urothelial cells. Finally, in the competition assay, LAB showed inhibitory effects against P. mirabilis. LAB could also inhibit the invasion of P. mirabilis into urothelial cells. CONCLUSIONS: Two LAB strains (PM206 and 229) exhibited antagonistic activity against P. mirabilis adhesion or invasion of urothelial cells in culture. In the future, probiotics may be used in food or urinary tract cleansing and could replace antibiotic treatments.

Antagonistic activity of Lactobacillus acidophilus RY2 isolated from healthy infancy feces on the growth and adhesion characteristics of enteroaggregative Escherichia coli.

Enteroaggregative Escherichia coli (EAggEC) infection is an important cause of acute diarrhea, affecting children in developing countries and travelers visiting tropical or subtropical areas. Three probiotics can exert bacteriostatic or bactericidal effects on human and animal intestinal pathogens, the efficiency of probiotics on EAggEC infection remains unclear. In this study, the antagonistic activity of probiotic bacteria isolated from infant faeces was examined against several EAggEC stains. While three isolates, Lactobacillus acidophilus RY2, Lactobacillus salivarius MM1 and Lactobacillus paracasei En4 were shown to significantly inhibit the growth of EAggEC. In addition, the antagonistic activity of the Lactobacillus species was maintained despite heating (100 degrees C, 15 min) of cell free culture supernatant (CFCS). The antagonistic activity of the CFCS however, could be reduced following lactate dehydrogenase treatment and at pH 7.2. Furthermore, in an adhesion-inhibition assay, L. acidophilus RY2 was shown to be more effective than L. salivarius MM1 and L. paracasei EN4. This study suggests that L. acidophilus RY2 could be used as a probiotic organism against EAggEC.

Use of specific primers based on the 16S-23S internal transcribed spacer (ITS) region for the screening Bifidobacterium adolescentis in yogurt products and human stool samples.

Effective methods for the identification and enumeration of lactic acid producing bacteria (LAB) cells are important for the quality control and assurance of probiotic products. In this study, we designed a polymerase chain reaction (PCR) primer set from the sequence in 16S-23S internal transcribed spacer (ITS) region and used it for the specific detection of Bifidobacterium adolescentis, one of the Bifidobacterium species used in probiotics. Specificity of the PCR primers, i.e., bits-1/bits-2, was assured by assay strains of B. adolescentis, other Bifidobacterium species, and strains of non-Bifidobacterium spp. Coupled with the use of a known primer set specific for Bifidobacterium species, Bifidobacterium strains and B. adolescentis could be identified from LAB strains in fermented dairy products and human fecal samples.