Probiootiliste laktobatsillide toime eksperimentaalsele Salmonella infektsioonile

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Salmonella enterica serovar Typhi võib põhjustada persisteeriva infektsiooni ja püsida granuloomidena maksakoes. Kuigi kõhutüüfuse esinemissagedus Eestis on madal, on see ohuks arengumaadesse reisijatele. Kuna S. Typhi tekitab kõhutüüfust ainult inimestel, siis kasutatakse selle uurimiseks eksperimentaalset mudelit, nakatades hiiri Salmonella Typhimuriumiga ja põhjustades kõhutüüfusele sarnase haiguse. Laktobatsillid kuuluvad inimese soole normaalsesse mikroobikooslusesse. Neid kasutatakse probiootikumidena, mis sobivates annustes mõjuvad tervisele kasulikult. Probiootiliste laktobatsillide toimemehhanismid on tüvespetsiifilised: otsene antagonistlik mõju patogeenidele seoses vesinikperoksiidi, piimhappe ja/või bakteriotsiinide tekkega, konkurents toitainetele, adhesioon ning immuunsuse modulatsioon. Kuid toimemehhanism persisteerivate infektsioonide puhul pole teada. Töö eesmärgiks oli selgitada laktobatsillide võimalikku toimet Salmonella persisteeriva infektsiooni korral hiire mudelis mikrobioloogiliste, histoloogiliste, biokeemiliste ja immunoloogiliste uuringutega ja teha kindlaks probiootilise Lactobacillus plantarum Inducia DSM 21379 mõju soole immuunsüsteemile. Salmonella Typhimuriumi ja laktobatsillide mikrobioloogilisteks uuringuteks tehti külvid verest, maksast, põrnast, peen- ja jämesoolest. Samade kudede morfoloogia määramiseks värviti koelõigud hematoksüliin eosiiniga. Oksüdatiivse stressi markerid: LPO, GSSG/GSH ja raua hulk ning tsütokiinide INF-γ, TNF-α ja IL-10 konsentratsiooni mõõdeti soole limaskestast ja maksast. Tulemused näitasid, et: 1. Persisteeriva S.Typhimurium infektsiooni korral leiti S. Typhimurium verest ja uuritud organitest; granuloomid maksast ja põrnast, kõrgenenud olid oksüdatiivse stressi näitajad ning proinflammatoorsed tsütokiinid INF-γ ja TNF-α sooles ja maksas. 2. Kahe in vitro kõrgete antimikroobsete ja antioksüdantsete omadustega inimpäritolu laktobatsilli tüve L. fermentum ME-3 ja L. acidophilus E-1 koosmanustamine 10 päeva jooksul ei eemaldanud S.Typhimuriumi, kuid vähendas oksüdatiivse stressi näitajaid kudedes. 3. Probiootilist bakterit L. plantarum Induciat sisaldava juustu manustamine hiirtele ühe kuu jooksul põhjustas laktobatsillide üldhulga tõusu ning peen- ja jämesoole lümfifolliikulite hüperplaasia. 4. Kombineeritud ravi ofloksatsiini ja L. fermentum ME-3-ga vähendas hiirtel S. Typhimuriumi hulka ja granuloomide teket maksas, samuti oksüdatiivse stressi näitajaid ja vähendas 10 päeva pärast nakatamist INF-γ hulka maksas ja sooles ning suurendas põletikuvastase tsütokiini IL-10 hulka maksas. Maksa granuloomide puudumine oli seotud kõrge laktobatsillide hulgaga sooles. Seega soodustab probiootikum L. fermentum ME-3 persisteeriva Salmonella sp. infektsiooni antimikroobse ravi korral oluliselt haigustekitaja eemaldamist oma antagonistliku aktiivsuse, antioksüdantse ja immuunmoduleeriva toime kaudu.Salmonella enterica serovar Typhi can lead to the development of persistent infection and the formation of granulomas in the liver. Though the prevalence of typhoid fever is low in Estonia, it is still a problem in the developing world. As S. Typhi is restricted to humans, there are no suitable animal models with the particular microbe. In order to study the pathogenesis of typhoid fever, S. Typhimurium has been used in a murine model of systemic infection mimicking persistence observed in S. Typhi carriers. Lactobacillus spp. belongs to normal human microbiota. Probiotic strains belong to the category of organisms classified as generally regarded as safe. Their mode of action is strain-specific: antagonistic influence on pathogens due to the production of hydrogen peroxide, lactic acid, and/or bacteriocins, adhesion, and immunomodulation. The influence and mode of action of probiotic lactobacilli on persistent infections is not known yet. We aimed to detect the effect of lactobacilli of human origin (the probiotic strain Lactobacillus fermentum ME-3 DSM 14241 and Lactobacillus acidophilus E1) on microbiological, histological, biochemical and immunological status of mice in Salmonella Typhimurium persistent infection model, and to detect the impact of the probiotic strain Lactobacillus plantarum Inducia DSM 21379 on the total count of lactobacilli and the immunological response in the gut of mice. For the microbiological detection of Salmonella Typhimurium and lactobacilli, cultures from the blood, liver, spleen, and gut were performed. Histological slides were prepared from the liver, spleen and ileum. The oxidative stress markers: glutathione redox ratio (GSSG/GSH), lipid peroxides (LPO) and Fe content, and concentration of cytokines: INF-γ, TNF-α ja IL-10 in the mucosa of the ileum and liver were estimated. The results of the study indicate that, 1. The elaborated persistent S.Typhimurium infection is characterized by the presence of viable S. Typhimurium in the blood and organs. The presence of granulomas in the liver and spleen is accompanied by increased levels of OxS indices and increased values of TNF-α and INF-γ in the gut and liver. 2. The application of two lactobacilli of human origin, L. fermentum ME-3 with high antimicrobial and antioxidative potential in vitro and L. acidophilus E-1, for 10 days, did not eradicate S.Typhimurium or prevent the developement of granulomas in the liver. An improvement of the gut mucosal barrier was detected due to decreased values of lipid peroxides and glutathione redox ratio of gut mucosa. 3 The intake of cheese containing Lactobacillus plantarum Inducia during one month increased the count of intestinal lactobacilli and hyperplasia of lymphatic follicles in the ileum and colon of healthy mice, indicating a trend of enhancement of the defence capability of intestinal mucosa by probiotic lactobacilli. 4. The combined treatment of ofloxacin and L. fermentum ME-3 increased the eradication of Salmonella Typhimurium, reduced the prevalence of granulomas in the liver, and decreased oxS indices. On Day 10 after inoculation, a reduction of INF-γ in the liver and an increase of IL-10 were detected in the mice without typhoid nodules in the liver. The absence of liver granulomas was associated with a higher total count of lactobacilli in the gut. Thus, in case of antibacterial treatment of persisting Salmonella sp. infection probiotic L. fermentum ME-3 facilitates the eradication of the agent due to its antagonistic, antioxidative and immuunomodulatory activity

The occurrence of antimicrobial resistance and class 1 integrons among commensal Escherichia coli isolates from infants and elderly persons

<p>Abstract</p> <p>Background</p> <p>The aim of our study was to compare the presence of the <it>intI1 </it>gene and its associations with the antibiotic resistance of commensal <it>Escherichia coli </it>strains in children with/without previous antibiotic treatments and elderly hospitalized/healthy individuals.</p> <p>Methods</p> <p>One-hundred-and-fifteen intestinal <it>E. coli </it>strains were analyzed: 30 strains from 10 antibiotic-naive infants; 27 from 9 antibiotic-treated outpatient infants; 30 from 9 healthy elderly volunteers; and 28 from 9 hospitalized elderly patients. The MIC values of ampicillin, cefuroxime, cefotaxime, gentamicin, ciprofloxacin, and sulfamethoxazole were measured by E-test and <it>IntI1 </it>was detected by PCR.</p> <p>Results</p> <p>Out of the 115 strains, 56 (49%) carried class 1 integron genes. Comparing persons without medical interventions, we found in antibiotic-naive children a significantly higher frequency of integron-bearing strains and MIC values than in healthy elderly persons (53% versus 17%; p < 0.01). Evaluating medical interventions, we found a higher resistance and frequency of integrons in strains from hospitalized elderly persons compared with non-hospitalized ones. Children treated with antibiotics had strains with higher MIC values (when compared with antibiotic-naive ones), but the integron-bearing in strains was similar. In most cases, the differences in resistance between the groups (integron-positive and negative strains separately) were higher than the differences between integron-positive and negative strains within the groups.</p> <p>Conclusion</p> <p>The prevalence of integrons in commensal <it>E. coli </it>strains in persons without previous medical intervention depended on age. The resistance of integron-carrying and non-carrying strains is more dependent on influencing factors (hospitalization and antibiotic administration) in particular groups than merely the presence or absence of integrons.</p

Eradication of Salmonella Typhimurium infection in a murine model of typhoid fever with the combination of probiotic Lactobacillus fermentum ME-3 and ofloxacin

<p>Abstract</p> <p>Background</p> <p>The aim of the study was to detect whether in experimental <it>Salmonella enterica </it>Typhimurium infection the probiotic <it>Lactobacillus fermentum </it>ME-3 in combination with fluoroquinolone therapy would eradicate <it>S. </it>Typhimurium, prevent the development of liver and spleen granulomas and improve the indices of oxidative stress in the ileum mucosa.</p> <p>The selected bacteriological, histological and biochemical methods were applied.</p> <p>Results</p> <p>Combined treatment with <it>L. fermentum </it>ME-3 and ofloxacin eradicated <it>Salmonella </it>Typhimurium from blood, ileum and liver, decreased the number of animals with liver and spleen granulomas and reduced the value of lipid peroxides in the ileum mucosa. Higher total counts of intestinal lactobacilli in all experimental groups were associated with the absence of liver granulomas.</p> <p>Conclusion</p> <p>The antimicrobial and antioxidative probiotic <it>L. fermentum </it>ME-3 combined with ofloxacin enhances the eradication of experimental <it>S</it>. Typhimurium infection. These observations on probiotic and antimicrobial co-action may serve as basis to develop new strategies for treatment of invasive bacterial infections of the gut.</p

TÜ Kliinikumi ühendlaboris isoleeritud anaeroobide spekter ja ravimitundlikkus

2001.–2006. a analüüsiti TÜ Kliinikumi ühendlaboris kliinilistest materjalidest isoleeritud anaeroobide rühmi ja antibiootikumitundlikkust ning võrreldi neid parodontiidi patogeenide sarnaste andmetega. Kliinilistest materjalidest isoleeritud anaeroobsetest parodontiidi patogeenidest olid sagedasemad prevotellad ja fusobakterid. Anaeroobide antibiootikumitundlikkus oli suhteliselt kõrge. Metronidasool toimis hästi gramnegatiivsetesse pulkbakteritesse, kuid grampositiivsed kokid olid resistentsemad. Klindamütsiin ja ampitsilliin/sulbaktaam olid tõhusad kõikide anaeroobirühmade suhtes. Beetalaktamaasi produtseerivate mikroobide osakaal oli 7–54%. Sagedasemad beetalaktamaasi suhtes positiivsed mikroobid olid Porphyromonas spp. ja Prevotella spp. Parodontiidi anaeroobsed patogeenid osutusid kliinilistest isolaatidest antibiootikumitundlikumateks. Eesti Arst 2008; 87(11):834−84

Staphylococcus epidermidis ja Klebsiella pneumoniae – võimalikud hospitaalinfektsioonide tekitajad Eesti lasteintensiivravi osakondades

Haiglasisesed infektsioonid ohustavad eelkõige pikaaegsel intensiivravil viibivaid patsiente, eriti aga enneaegseid ja madalakaalulisi vastsündinuid. Hospitaalinfektsioonide tekitajateks on tinglikult patogeensed mikroobid, mis pärinevad patsientide enda mikrofloorast või haigla keskkonnast. Mitmekülgse bakterioloogilise uuringuga Eesti lasteintensiivravi osakondades selgitati seal tsirkuleerivate mikroobitüvede etioloogilist struktuuri, kolonisatsiooni ning mikroobide tekitatud infektsioone. Eesti Arst 2003; 82 (4): 239–24

Persistence of Escherichia coli Clones and Phenotypic and Genotypic Antibiotic Resistance in Recurrent Urinary Tract Infections in Childhood▿

We assessed the clonality of consecutive Escherichia coli isolates during the course of recurrent urinary tract infections (RUTI) in childhood in order to compare clonality with phenotypic antibiotic resistance patterns, the presence of integrons, and the presence of the sul1, sul2, and sul3 genes. Altogether, 78 urinary E. coli isolates from 27 children, who experienced recurrences during a 1-year follow-up after the first attack of acute pyelonephritis, were investigated. The MICs of sulfamethoxazole, trimethoprim-sulfamethoxazole (SXT), ampicillin, cefuroxime, cefotaxime, and gentamicin and the presence or absence of the intI gene for class 1 integrons and the sulfamethoxazole resistance-encoding genes sul1, sul2, and sul3 were determined. All E. coli strains were genotyped by pulsed-field gel electrophoresis. There were no significant differences in the prevalences of resistance to beta-lactams and SXT between initial and consecutive E. coli isolates (41 versus 45% and 41 versus 29%, respectively). However, the E. coli strains obtained after SXT administration more frequently carried two or more sul genes than the nonexposed strains (9/21 [43%] versus 11/57 [19%], respectively; P = 0.044). In 78% of the patients, the recurrence of unique clonal E. coli strains alone or combined with individual strains was detected. Phenotypic resistance and the occurrence of sul genes were more stable in clonal strains than in individual strains (odds ratios, 8.7 [95% confidence interval {95% CI}, 1.8 to 40.8] and 4.4 [95% CI, 1.1 to 17.7], respectively). Thus, in children with RUTIs, the majority of E. coli strains from consecutive episodes are unique persisting clones, with rare increases in the initially high antimicrobial resistance, the presence of sul genes, and the presence of integrons

Effect of early directed implementation of family-integrated care measures on colonisation with Enterobacteriaceae in preterm neonates in NICU

Background Hospital-acquired strains (HASs) and multiresistant strains in neonatal intensive care unit often harbour virulence and resistance mechanisms, carrying the risk of invasive infections. We describe colonisation with Enterobacteriaceae in neonates receiving early directed versus routine family-integrated care (FIC) within the first month of life.Methods A prospective cohort study included neonates with a gestational age below 34 weeks. During the first period, neonates were admitted to an open bay unit with transfer to the single-family room if available; feeding with the mother’s own breast milk (MOBM) was introduced within 24 hours, and skin-to-skin contact (SSC) within 5 days of life (the routine care group). During the second period, following a wash-in of 2 months, care in a single-family room within 48 hours, the introduction of MOBM within two and SSC in 48 hours were applied (the intervention group). Enterobacteriaceae isolated from neonatal stool, breast milk and parental skin swabs were genotyped, Simpson’s Index of Diversity (SID) calculated, and extended-spectrum beta-lactamases (ESBL) detected.Results In 64 neonate-parents’ groups, 176 Enterobacteriaceae, 87 in routine care and 89 in the intervention group were isolated; 26 vs 18 were HAS and one vs three ESBL positive, respectively. In the intervention group compared with the routine care group, SSC and MOBM feeding was started significantly earlier (p&lt;0.001); during the first week of life, time spent in SSC was longer (median hours per day 4.8 (4–5.1) vs 1.9 (1.4–2.6), p&lt;0.001) and the proportion of MOBM in enteral feeds was higher (median (IQR) 97.8% (95.1–100) vs 95.1% (87.2–97.4), p=0.011). Compared with the routine care group, the intervention group had higher SID and a reduction of HAS by 33.1% (95% CI 24.4% to 42.4%) in time series analysis.Conclusions Early implementation of FIC measures may hold the potential to increase diversity and reduce colonisation with HAS Enterobacteriaceae

Surf en Chine : Entre volonté politique et engouement économique

La Chine souhaite transformer Hainan, île tropicale au sud du pays, en " Hawaï chinois ". Sa stratégie : accueillir des compétitions internationales de surf professionnel. Un objectif entre volonté politique et engouement économique qui peine à trouver écho auprès de la population locale, peu tournée vers la pratique de ce sport

Quantification of Clostridium difficile in Antibiotic-Associated-Diarrhea Patients▿

Comparing culture- and non-culture-based methods for quantifying Clostridium difficile in antibiotic-associated-diarrhea patients, we found that the real-time PCR method correlated well with quantitative culture and was more sensitive. A positive association between the population levels of C. difficile and the presence of its toxins was found