1.
Ambalam, Padma, et al.
(författare)
Bile stimulates Cell Surface Hydrophobicity, Congo Red Binding and Biofilm Formation of Lactobacillus strains.
2012
Ingår i: FEMS Microbiology Letters. - : Oxford University Press (OUP). - 1574-6968 .- 0378-1097. ; 333:1, s. 10-19
Tidskriftsartikel (refereegranskat) abstract
Seventeen Lactobacillus strains were tested for cell surface hydrophobicity (CSH) using the salt aggregation test (SAT) and Congo red binding (CRB) assay. CRB was pH and ionic strength dependent and protease sensitive and in the presence of 100 μg/ml cholesterol, the CRB was significantly reduced. Autoaggregating (AA) L. crispatus strains showed 50% more CRB than the reference strain, the curli-producing E.coli MC4100. CRB of L. crispatus 12005, L. paracasei F8, L. plantarum F44 and L. paracasei F19 was enhanced when grown in MRS broth with 0.5% taurocholic acid (TA) or 5% porcine bile (PB) (P<0.05). CSH was also enhanced for the non-AA strains, L. plantarum F44, L. paracasei F19 and L. rhamnosus GG when grown in MRS broth with 0.5% TA, 5% PB or 0.25% mucin with enhanced biofilm formation in MRS broth with bile (P<0.05). Two AA strains, L. crispatus 12005 and L. paracasei F8, developed biofilm independent of bile or mucin. In summary, under bile stressed growth conditions, early (24 h cultures) biofilm formation is associated with an increase in hydrophobic cell surface proteins and high CRB. Late mature (72 h culture) biofilm contained more carbohydrates as shown by crystal violet staining. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd.All rights reserved.
2.
3.
Ananieva, Olga, et al.
(författare)
Immune responses to bile-tolerant Helicobacter species in patients with chronic liver diseases, a randomized population group, and healthy blood donors
2002
Ingår i: Clinical and Diagnostic Laboratory Immunology. - 1071-412X. ; 9:6, s. 1160-1164
Tidskriftsartikel (refereegranskat) abstract
Bile-tolerant Helicobacter species such as Helicobacter pullorum, Helicobacter bilis, and Helicobacter hepaticus are associated with hepatic disorders in animals and may be involved in the pathogenesis of chronic liver diseases (CLD) in humans. Antibody responses to cell surface proteins of H. pullorum, H. bilis, and H. hepaticus in serum samples from patients with CLD, a randomized population group, and healthy blood donors were evaluated by using enzyme linked immunosorbent assay (ELISA). The results were compared with the antibody responses to Helicobacter pylori. For analysis of a possible cross-reactivity between bile-tolerant Helicobacter species and H. pylori, sera from a subpopulation of each group were absorbed with a whole-cell extract of H. pylori and retested by ELISA. Results before absorption showed that the mean value of the ELISA units for H. pullorum was significantly higher in patients with CLD than in healthy blood donors (P = 0.01). Antibody reactivity to cell surface protein of H. hepaticus was also significantly higher in the CLD patients than in the healthy blood donors and the population group (P = 0.005 and P = 0.002, respectively). Following the absorption, antibody responses to H. pullorum decreased significantly in all three groups (P = 0.0001 for CLD patients, P = 0.0005 for the population group, and P < 0.0001 for the blood donors), indicating that cross-reactivity between H. pylori and other Helicobacter spp. occurs. The antibody responses to H. hepaticus and H. bilis in CLD patients remained high following absorption experiments compared to ELISA results before absorption. The significance of this finding requires further investigations.
4.
Asrat, Daniel, et al.
(författare)
Antimicrobial susceptibility pattern of Helicobacter pylori strains isolated from adult dyspeptic patients in Tikur Anbassa University Hospital, Addis Ababa, Ethiopia
2004
Ingår i: Ethiopian Medical Journal. - 0014-1755. ; 42:2, s. 79-85
Tidskriftsartikel (refereegranskat) abstract
Presently, there is no published information on the antimicrobial susceptibility pattern of H. pylori strains in Ethiopia to guide the choice of drug for therapy. Therefore, it is becoming clinically relevant to test the in vitro susceptibility of H. pylori clinical isolates prior to treating patients. Susceptibility testing was performed on 50 clinical H. pylori isolates obtained from adult dyspeptic patients referred to the gastrointestinal (GI) Clinic of Tikur Anbassa University Hospital. Five antibiotics were evaluated, by using the Episolmeter test (E-test). The antibiogram of 50 H. pylori clinical isolates showed that all strains were sensitive to clarithromycin, erythromycin and tetracycline, while 38/50 (76%) and 3/50 (6%) of the strains were resistant to metronidazole and amoxicillin, respectively. Infection by metronidazole or amoxicillin resistant H. pylori is an important factor leading to treatment failure. Testing of all H. pylori clinical isolates to metronidazole and amoxicillin is recommended. If it is not possible to perform susceptibility tests on each clinical isolate, a program to survey the prevalence of resistance should be implemented in a given area or population. When treatment of H. pylori infection is indicated in dyspeptic patients, the potential availability simplicity of use, safety and low cost of the antimicrobial agents have to be taken into account.
5.
Asrat, D, et al.
(författare)
Prevalence of Helicobacter pylori infection among adult dyspeptic patients in Ethiopia
2004
Ingår i: Annals of Tropical Medicine and Parasitology. - : Informa UK Limited. - 1364-8594 .- 0003-4983. ; 98:2, s. 181-189
Tidskriftsartikel (refereegranskat) abstract
In developing countries such as Ethiopia, where chronic gastritis and peptic-ulcer disease are the most common endoscopic findings, it is important to study the association between Helicobacter pylori infection and gastroduodenal diseases. Both invasive and non-invasive diagnostic methods were therefore used to investigate 300, consecutive, adult patients with dyspepsia, from the gastrointestinal clinic of Tikur Anbassa University Hospital, Addis Ababa. The apparent overall prevalence of H. pylori infection varied according to the detection method employed. Culture revealed H. pylori in only 69%, of the patients but this pathogen appeared more common when rapid urease tests (71%), PCR-denaturating gradient gel electrophoresis (91%), histopathology (81%), silver staining (75%) or stool-antigen tests (81%) were employed. Antibodies to H. pylori were detected, both by enzyme immuno-assay (EIA) and immunoblotting, in approximately 80%, of the patients, whether the antigens used were of a reference strain or from a local isolate of H. pylon. When some of the EIA-positive and EIA-negative sera were cross-absorbed with antigens of Campylobacter jejuni and re-tested by EIA, the H. pylori-positive sera remained positive and the negative sera remained negative. Dyspeptic patients in Ethiopia, like most of those previously observed elsewhere in Africa, are often infected with H. pylon. It is important that the management of these patients should not be hampered by the misinterpretation of the African epidemiology of this pathogen.
6.
Asrat, Daniel, et al.
(författare)
Prevalence of Helicobacter pylori vacA and cagA genotypes in Ethiopian dyspeptic patients
2004
Ingår i: Journal of Clinical Microbiology. - 1098-660X. ; 42:6, s. 2682-2684
Tidskriftsartikel (refereegranskat) abstract
A total of 300 gastric biopsy samples and 50 Helicobacter pylori isolates were collected from Ethiopian adult dyspeptic patients. The vacA and cagA genes were detected in 90 and 79% of biopsy specimens, respectively, and in 100 and 87% of clinical isolates, respectively. Both genes were detected in 84% of the gastric biopsy samples and in 87% of the clinical isolates. Among vacA genotypes, the s1/m1 genotype was the most common in gastric biopsy samples (48%). The vacA and cagA positive H. pylori strains were detected to a higher degree in patients with chronic active gastritis (71%) than patients with other histopathological findings (29%) (P < 0.05).
7.
Dzierzanowska-Fangrat, Katarzyna, et al.
(författare)
Lack of an association between Helicobacter infection and autoimmune hepatitis in children
2006
Ingår i: Polish Journal of Microbiology. - 1733-1331. ; 55:2, s. 157-159
Tidskriftsartikel (refereegranskat) abstract
An association between Helicobacter infection and autoimmune hepatitis (AIH) in children was investigated. The prevalence of antibodies to H. pylori did not differ between the AIH and the control group, (22% versus 14%), and antibodies to non-gastric Helicobacter were not detected in either group. H. pylori DNA was found in two AIH liver tissues, but Helicobacter was not cultured from any sample.
8.
Kondepudi, Kanthi Kiran, et al.
(författare)
A novel multi-strain probiotic and synbiotic supplement for prevention of Clostridium difficile infection in a murine model.
2014
Ingår i: Microbiology and Immunology. - : Wiley. - 1348-0421 .- 0385-5600. ; 58:10, s. 552-558
Tidskriftsartikel (refereegranskat) abstract
The protective effect of a multi-strain probiotic and synbiotic formulation was evaluated in C57BL/6 mice infected with Clostridium difficile (CD) NAP1/027. Antibiotic treated mice were divided into four groups. Group 1, fed with a synbiotic formulation consisting of Lactobacillus plantarum F44, L. paracasei F8, Bifidobacterium breve 46, B. lactis 8:8, galacto-oligosaccharides (GOS), isomalto-oligosaccharides (IMOS) and resistant starch (RS); group 2, fed with the same four probiotic strains as in group 1; group 3, fed with the same prebiotic supplements as mentioned in group 1 for seven days before CD infection and group 4, the control group, was antibiotic treated and infected with NAP1/027 strain. Faeces and caecal contents were collected for microbial cell viability, quantitative PCR (qPCR), toxin analyses and histopathology. Synbiotics and probiotics fed mice showed a significant increase of total bifidobacteria (P < 0.05). Total lactobacilli count was increased in group 1. The caecal toxins were negative in group 2 mice, and one sample each from group 1 and 3 was positive. qPCR of caecal content showed significant reduction in NAP1/027 DNA copies in group 1-2 and significantly higher numbers of B. breve 46, L. plantarum F44 and L. paracasei F8 in group 1 and 2 (P < 0.05) but much less pronounced in group 3-4. This study demonstrated that the newly developed synbiotic or multi-strain probiotic formulation conferred protection against NAP1/027 infection in C57BL/6 mice. This holds promising to conduct future human studies.
9.
Kondepudi, Kanthi Kiran, et al.
(författare)
Prebiotic-non-digestible oligosaccharides preference of probiotic bifidobacteria and antimicrobial activity against Clostridium difficile.
2012
Ingår i: Anaerobe. - : Elsevier BV. - 1095-8274 .- 1075-9964. ; 18:5, s. 489-497
Tidskriftsartikel (refereegranskat) abstract
Bifidobacterium breve 46, Bifidobacteriumlactis 8:8 and Bifidobacteriumlongum 6:18 and three reference strains B. breve CCUG 24611, B. lactis JCM 10602, and Bifidobacteriumpseudocatenulatum JCM 1200 were examined for acid and bile tolerance, prebiotic utilization and antimicrobial activity against four Clostridium difficile (CD) strains including the hypervirulent strain, PCR ribotype NAP1/027. B. lactis 8:8 and B. lactis JCM 10602 exhibited a high tolerance in MRSC broth with pH 2.5 for 30 min. B. breve 46 and B. lactis 8:8 remained 100% viable in MRSC broth with 5% porcine bile after 4 h. All six strains showed a high prebiotic degrading ability (prebiotic score) with galactooligosaccharides (GOS), isomaltooligosaccharides (IMOS) and lactulose as carbon sources and moderate degradation of fructooligosaccharides (FOS). Xylooligosaccharides (XOS) was metabolized to a greater extent by B. lactis 8:8, B. lactis JCM 10602, B. pseudocatenulatum JCM 1200 and B. longum 6:18 (prebiotic score >50%). All strains exhibited extracellular antimicrobial activity (AMA) against four CD strains including the CD NAP1/027. AMA of B. breve 46, B. lactis 8:8 and B. lactis JCM 10602 strains was mainly ascribed to a combined action of organic acids and heat stable, protease sensitive antimicrobial peptides when cells were grown in MRSC broth with glucose and by acids when grown with five different prebiotic-non-digestible oligosaccharides (NDOs). None of C. difficile strains degraded five prebiotic-NDOs. Whole cells of B. breve 46 and B. lactis 8:8 and their supernatants inhibited the growth and toxin production of the CD NAP1/027 strain.
10.
Kornilovska, Iryna, et al.
(författare)
Immunogenic proteins of Helicobacter pullorum, Helicobacter bilis and Helicobacter hepaticus identified by two-dimensional gel electrophoresis and immunoblotting.
2002
Ingår i: Proteomics. - 1615-9861. ; 2:6, s. 775-783
Tidskriftsartikel (refereegranskat) abstract
The ecological niches occupied by various species of Helicobacter are not yet known and the full spectrum of diseases associated with Helicobacter infections are not yet defined. Since these fastidious microaerofilic bacteria require special growth conditions new and improved molecular and serologic diagnostic methods have been developed to increase our understanding of their pathogenesis and virulence characteristics. Immunogenic cell surface proteins of Helicobacter pullorum, Helicobacter bilis, and Helicobacter hepaticus were characterised by proteomic techniques using two-dimensional electrophoresis and immunoblotting with antisera from immunised rabbits. Cross-reactivity between the three Helicobacter species were analysed after a four-step cross-absorption experiment. For H. pullorum, H. bilis and H. hepaticus 21, 13 and 27 specific immunogenic proteins, respectively, were identified. These proteins could be of important sero-diagnostic value for analyses of sera from humans, laboratory animals and for the veterinarian field.
