The Effect of Prebiotic Chitosan on the growth and antimicrobial characteristic of Probiotic lactobacilli

Background and Aim: Nowadays, prebiotics are the matter of interest, because of stimulating the growth and activity of beneficial enteric bacteria (probiotic) and their antimicrobial and antitumor characteristics. The aim of this research is to study the effect of prebiotic Chitosan on the growth of probiotic bacteria and their antimicrobial effect. Materials and Methods: This research was done in 2010 in order to study of the effect of prebiotic chitosan on the growth of probiotic bacteria Lactobacillus acidophilus PTCC 1643 and Lactobacillus casei PTCC 1608 by using of drawing growth curve of these bacteria in the presence of different chitosan concentrations, also, the effect of this prebiotic on antimicrobial properties of probiotic bacteria was investigated against Escherichia coli by using of overlay method and blank disk method. Results: According to the test results, the growth of two probiotic bacteria were increased in the presence of chitosan and the most effective concentration of prebiotic chitosan was achieved, 6.5 (mg/mL).Antimicrobial effects of probiotic bacteria were increased in the presence of chitosan against E.coli especially Entrohaemoragic E. coli in comparison with the time that probiotic bacteria were used alone. Conclusions: According to the results of this study, prebiotic chitosan, due to increasing effect on the growth and antimicrobial characteristic of probiotic lactobacillus, can be a proper candidate for effective symbiotic compound against pathogenic bacteria

The study of Antimicrobial and Anti-adhesive effect of ProbioticLactobacilli on Uropathogenic Escherichia coli (UPEC)

Introduction: One of the most important factors in Urinary Tract Infection caused by Uropathogenic Escherichia coli, is the attachment of bacteria to the host cell surface. Thus, inhibition of bacterial attachment is the appropriate action to prevent infection. The aim of this study was to investigate the antimicrobial and especially anti adhesive characteristics of probiotic bacteria against Escherichia coli by using microbial techniques. Materials and methods: In this study two strains of Lactobacillus acidophilus PTCC 1643 and Lactobacillus casei PTCC 1608 were used .40 Uropathogenic Escherichia coli were collected from Semnan province hospitals.20 samples with the more capability of biofilm production were selected for microbial tests. To evaluate the antimicrobial activity of complete culture and supernatant of probiotic lactobacilli, modified double layer method and dilution of supernatant were used, respectively. The mechanism of co- aggregation of lactobacilli with pathogens was examined. The microtitre plate method was used to detect anti-adhesive activity of Lactobacilli supernatant. Results: The antimicrobial and anti-adhesive effects of probiotic lactobacilli on Uropathogenic Escherichia coli were confirmed in all tests. In this study, Lactobacillus casie with the growth inhibitory (42/7 mm) and anti-adhesive (46/7mm) effects were reported as a proper probiotic bacterium. Discussion and conclusion: According to the results, the probiotic lactobacilli have spectacular effects to prevent attachment, biofilm formation and pathogenicity of UPEC, so using them to prevent and treat Urinary tract infection is a practical, reasonable and acceptable method

Biofilm formation, antimicrobial susceptibility, serogroups and virulence genes of uropathogenic E. coli isolated from clinical samples in Iran

Abstract Background Uropathogenic Escherichia coli O- Serogroups with their virulence factors are the most prevalent causes of UTIs. The present research performed to track common uropathogenic E.coli serogroups, antibiotic resistance pattern of strains and prevalence of virulence genes in isolations having the ability to constitute biofilm. Methods In this research 130 E.coli isolation from patients having UTI symptoms were collected and antimicrobial resistance pattern was performed by Kirby-Bauer method. Polymerase chain reaction was done using primer pairs to identify common serogroups of uropathogenic E.coli and studying virulence genes in isolations creating biofilm. Results Among 130 E.coli isolates, 80 (61.53 %) were able to make biofilm that 15 isolates (18.75 %) indicated strong reaction, 20 (25 %) of medium and 45 (56.25 %) of weak biofilm reaction. Among isolations creating biofilm, the highest resistance reported to Ampicillin (87.5 %) and the lowest to Nitrofurantoin (3.75 %). The frequency of fimH, pap, sfa and afa genes in isolations having the ability to create strong biofilm reported 93.33 %, 86.66 %, 86.66 % and 66.66 %, respectively. Conclusions The findings indicated the importance of virulence genes in serogroups producing uropathogenic E.coli biofilm. It is recommended that strains producing biofilm before antibiotic use should be studied

Biodegradation of the Most Heavier Fraction of Crude Oil, Asphaltene, by Bacillus toyonensis BCT-7112

There have been few records on microorganisms with the ability to survive and utilizehigh concentrations of heavy fractions of crude oil like asphaltene. These organisms are applicable in different aspects of petroleum industry from extraction to refining and environmental pollution treatment. To isolate such indigenous bacteria, a highly viscouscrude oil was selected and its asphaltene extracted. Isolation, enrichment, and purification of the bacterium were done in ISO 9439 medium at room temperature and 45°C as well. Studying morphological characteristics, biochemical and molecular tests were performed to identify isolated bacteria. The 16S rRNA gene sequence was subjected. To study the biodegradation of asphaltene, isolated bacteria were cultured in ISO 9439 medium for 2, 20 and 50 d at 25°C and 45°C.The efficiency of asphaltene degradationwas evaluated by FT-IR spectroscopy analysis. The bacterial species, which could use asphaltene as the sole carbon and energy source, were selected. Among all, Bacillus toyonensis BCT-7112 had the most degrading ability on asphaltene. The percentage of asphaltene degradation after 50 d of incubation at 25°C was 64.8%, and it was 60% at 45°C. Based on the FT-IR analysis, the isolate had the most biodegrading effect on Aldehyde compounds in comparison with other asphaltene ingredients. This amount of degradation is the most among the present records in literature

The Co-aggregation effects of probiotic lactobacillus against some pathogenic bacteria

Background and Aim: Nowadays, probiotic Lactobacilli are as suitable candidate to control and treat diseases, due to their microbial characteristics and especially co-aggregation which prevent attachment and colonization of pathogenic bacteria. The aim of this study is investigation of antimicrobial and co-aggregation of probiotic bacteria, Lactobacillus.plantarum PTCC 1601, Lactobacillus.casei PTCC 1801, and isolated Lactobacilli from dairy products of Sabzevar city against some pathogenic bacteria. Materials and Methods: Isolation and purification of probiotic lactobacilli from Sabsevar traditional dairy products was done by common methods. Among 10 isolated probiotic lactobacilli,two of them which had more probiotic  potentail were selected and  their  phylogenetic and molecular characteristics  was investigated by  16s rDNA sequencing technique. Antimicrobial and anti-adhesive effect of probiotic bacteria was examined by Modified Double Layer, Co-Culture and Co-aggregation methods. Co-aggregation of probotic bacteria with pathogens was seen by ATM microscope. Results: In this study, isolated probotic lactobacilli from Sabsevar traditional dairy products and standard bacteria, L.plantarum and L.casei shown the most antimicrobial effect and co-aggregation with pathogenic bacteria, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus, respectively. Inhibition of pathogenic bacteria in the presence of probotic bacteria was seen by co-culture method. Conclusions: According to this study, all used probiotic bacteria in this research inhibited the growth of pathogenic bacteria, among them L.casei had spectacular antimicrobial effect and co-aggregation with pathogenic bacteria and it may be used as a suitable candidate to control diseases

An In Vivo Study of Lactobacillus rhamnosus (PTCC 1637) as a New Therapeutic Candidate in Esophageal Cancer

OBJECTIVE: This study is aimed at investigating the effect of probiotic Lactobacillus rhamnosus on esophageal cancer in vivo and in vitro. METHODS AND RESULTS: In this study, the cytotoxicity effects of L. rhamnosus supernatant and whole-cell culture on a cancer cell line (Kyse30) compared to 5fu were evaluated by the MTT assay. The real-time PCR method was used to analyse the L. rhamnosus supernatant effect on the expression of Wnt signaling pathway genes. An in vivo investigation in nude mice was done to assess the anti-tumor activity of L. rhamnosus supernatant and whole-cell culture. Both supernatant and whole-cell culture of L. rhamnosus reduced cell survival (Kyse30) P < 0.001. The supernatant of this bacterium significantly reduced the expression of Wnt signaling pathway genes. Administration of supernatant and whole-cell culture of L. rhamnosus expressively reduced tumor growth compared to the control group. The effects of this bacterium on tumor necrosis were quite evident, pathologically P < 0.01. CONCLUSION: This study is the first report that assessed the potential impact of L. rhamnosus, especially its supernatant on esophageal cancer and Wnt signaling pathway genes. Therefore, this bacterium can be a harmless candidate for esophageal cancer therapy