scholarly journals Contrasting microbiota profiles observed in children carrying either Blastocystis spp. or the commensal amoebas Entamoeba coli or Endolimax nana

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Juan F. Alzate ◽  
Miguel Toro-Londoño ◽  
Felipe Cabarcas ◽  
Gisela Garcia-Montoya ◽  
Ana Galvan-Diaz

Abstract Recent studies have shown how intestinal parasites can modulate gut microbiota. This observation is not surprising since the human intestinal lumen, like any other niche, is a battlefield of microbial competition, and Eukaryotes can affect bacterial populations. Intestinal pathogenic protist has been associated with reshaping the microbial community structure; however, the interactions between the colonic bacterial communities and parasites like Blastocystis spp., Entamoeba coli, and Endolimax nana have been poorly studied. In this work, we studied the distal intestinal bacterial microbiota of 49 children attending 7 public daycare centers in Medellin, Colombia, and compared the bacterial microbiota structure in the presence or absence of the protists Blastocystis spp., E. coli, and E. nana. Parasite colonization was associated with an increase in bacterial richness. Moreover, Blastocystis spp. presented a positive relationship with Prevotella, since this bacterium was selectively enriched in children carrying it. Remarkably, the E. coli colonized children showed a microbial profile that was closer to uninfected controls, although some bacterial taxa displayed to be enriched. This is the case for Akkermansia, which showed to be favored in E. coli colonized individuals, while notably reduced in the Blastocystis spp. parasitized group.

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 879
Author(s):  
Stefan G. Buzoianu ◽  
Ava M. Firth ◽  
CallaBria Putrino ◽  
Fabio Vannucci

A healthy microbial community in the gut of piglets is critical to minimize the negative performance consequences associated with dietary and environmental changes that occur at weaning. Tonisity Px, an isotonic protein drink, is a potential alternative to balance the gut microbiota as it contains key ingredients for nourishing the small intestine. In the present study, 16 litters comprising 161 piglets were randomly allocated to a group to which Tonisity Px was provided from days 2 to 8 of age (TPX group) or to a control group, to which no Tonisity Px was provided. The TPX group also received Tonisity Px in the 3 days before and after weaning. At days 9, 17, and 30 of age, fecal and ileum samples were collected from piglets belonging to both groups and analyzed using 16S rRNA gene sequencing, semiquantitative PCR of Rotavirus serogroups, and semiquantitative Escherichia coli culture. Overall, Tonisity Px increased the abundance of beneficial bacterial populations (Lactobacillus and Bacteroides species) and reduced potentially pathogenic bacterial populations (E. coli and Prevotellaceae), in both the pre-weaning and post-weaning periods.


2019 ◽  
Author(s):  
Mergim Gjonbalaj ◽  
James W. Keith ◽  
Mytrang Do ◽  
Tobias M. Hohl ◽  
Eric G. Pamer ◽  
...  

AbstractThe complex bacterial populations that constitute the gut microbiota can harbor antibiotic-resistance genes (ARGs), including those encoding for β-lactamase enzymes (BLA), which degrade commonly prescribed antibiotics such as ampicillin. While it is known that ARGs can be transferred between bacterial species, with dramatic public health implications, whether expression of such genes by harmless commensal bacterial species shields antibiotic-sensitive pathogens in trans by destroying antibiotics in the intestinal lumen is unknown. To address this question, we colonized GF mice with a model intestinal commensal strain of E. coli that produces either functional or defective BLA. Mice were subsequently infected with Listeria monocytogenes or Clostridioides difficile followed by treatment with oral ampicillin. Production of functional BLA by commensal E. coli markedly reduced clearance of these pathogens and enhanced systemic dissemination during ampicillin treatment. Pathogen resistance was independent of ARG acquisition via horizontal gene transfer but instead relied on antibiotic degradation in the intestinal lumen by BLA. We conclude that commensal bacteria that have acquired ARGs can mediate shielding of pathogens from the bactericidal effects of antibiotics.


2010 ◽  
Vol 77 (1) ◽  
pp. 258-268 ◽  
Author(s):  
Gustavo A. Romero-Pérez ◽  
Kim H. Ominski ◽  
Tim A. McAllister ◽  
Denis O. Krause

ABSTRACTFeces from cattle production are considered important sources of bacterial contamination of food and the environment. Little is known about the combined effects of arctic temperatures and fodder tannins on rumen and hindgut bacterial populations. Individual rumen liquor and rectal fecal samples from donor steers fed either alfalfa silage or sainfoin (Onobrychis viciifoliaScop.) silage and waterad libitumwere collected weekly on the first three sampling days and fortnightly afterwards. The daily ambient temperatures were registered and averaged to weekly mean temperatures. Steers fed sainfoin silage had lower (P< 0.05) concentrations of branched-chain volatile fatty acids (VFA) than those fed alfalfa silage. All VFA concentrations were higher (P< 0.001) in rumen liquor samples than in fecal samples. The interaction of sample type and diet showed a significant effect (P< 0.05) on the proportions of the bacterial community that were from the phylaProteobacteriaandVerrucomicrobia.Ambient temperature had an indirect effect (P< 0.05) on the phylumFirmicutes, as it affected its proportional balance. The bacterial population diversity in samples appeared to decrease concurrently with the ambient temperature. The phylumFirmicutesexplained the first principal component at 64.83 and 42.58% of the total variance in rumen liquor and fecal samples, respectively. The sample type had a larger effect on bacterial communities than diet and temperature. Certain bacterial populations seemed to be better adapted than others to environmentally adverse conditions, such as less access time to nutrients due to higher motility and rate of passage of digesta caused by extreme temperatures, or antimicrobials such as tannins, possibly due to an influence of their biogeographical location within the gut.


2005 ◽  
Vol 6 (1) ◽  
pp. 105-118 ◽  
Author(s):  
G. M. Nava ◽  
L. R. Bielke ◽  
T. R. Callaway ◽  
M. P Castañeda

AbstractThe intestinal mucosa represents the most active defense barrier against the continuous challenge of food antigens and pathogenic microorganisms present in the intestinal lumen. Protection against harmful agents is conferred by factors such as gastric acid, peristalsis, mucus, intestinal proteolysis, and the intestinal biota. The establishment of beneficial bacterial communities and metabolites from these complex ecosystems has varying consequences for host health. This hypothesis has led to the introduction of novel therapeutic interventions based on the consumption of beneficial bacterial cultures. Mechanisms by which probiotic bacteria affect the microecology of the gastrointestinal tract are not well understood, but at least three mechanisms of action have been proposed: production/presence of antibacterial substances (e.g., bacteriocins or colicins), modulation of immune responses and specific competition for adhesion receptors to intestinal epithelium. The rapid establishment of bacterial communities has been thought to be essential for the prevention of colonization by pathogenic bacteria. Some animal models suggest that the reduction in bacterial translocation in neonatal animals could be associated with an increase in intestinal bacterial communities and bacteriocin-like inhibitory substances produced by these species. This review emphasizes the role of the intestinal microbiota in the reduction of the gastrointestinal infections and draws heavily on studies in poultry.


mSystems ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Johannes Cairns ◽  
Katariina Koskinen ◽  
Reetta Penttinen ◽  
Tommi Patinen ◽  
Anna Hartikainen ◽  
...  

ABSTRACTMobile genetic elements such as conjugative plasmids are responsible for antibiotic resistance phenotypes in many bacterial pathogens. The ability to conjugate, the presence of antibiotics, and ecological interactions all have a notable role in the persistence of plasmids in bacterial populations. Here, we set out to investigate the contribution of these factors when the conjugation network was disturbed by a plasmid-dependent bacteriophage. Phage alone effectively caused the population to lose plasmids, thus rendering them susceptible to antibiotics. Leakiness of the antibiotic resistance mechanism allowing Black Queen evolution (i.e. a “race to the bottom”) was a more significant factor than the antibiotic concentration (lethal vs sublethal) in determining plasmid prevalence. Interestingly, plasmid loss was also prevented by protozoan predation. These results show that outcomes of attempts to resensitize bacterial communities by disrupting the conjugation network are highly dependent on ecological factors and resistance mechanisms.IMPORTANCEBacterial antibiotic resistance is often a part of mobile genetic elements that move from one bacterium to another. By interfering with the horizontal movement and the maintenance of these elements, it is possible to remove the resistance from the population. Here, we show that a so-called plasmid-dependent bacteriophage causes the initially resistant bacterial population to become susceptible to antibiotics. However, this effect is efficiently countered when the system also contains a predator that feeds on bacteria. Moreover, when the environment contains antibiotics, the survival of resistance is dependent on the resistance mechanism. When bacteria can help their contemporaries to degrade antibiotics, resistance is maintained by only a fraction of the community. On the other hand, when bacteria cannot help others, then all bacteria remain resistant. The concentration of the antibiotic played a less notable role than the antibiotic used. This report shows that the survival of antibiotic resistance in bacterial communities represents a complex process where many factors present in real-life systems define whether or not resistance is actually lost.


2013 ◽  
Vol 80 (1) ◽  
pp. 110-118 ◽  
Author(s):  
Adelumola Oladeinde ◽  
Thomas Bohrmann ◽  
Kelvin Wong ◽  
S. T. Purucker ◽  
Ken Bradshaw ◽  
...  

ABSTRACTUnderstanding the survival of fecal indicator bacteria (FIB) and microbial source-tracking (MST) markers is critical to developing pathogen fate and transport models. Although pathogen survival in water microcosms and manure-amended soils is well documented, little is known about their survival in intact cow pats deposited on pastures. We conducted a study to determine decay rates of fecal indicator bacteria (Escherichia coliand enterococci) and bovine-associated MST markers (CowM3, Rum-2-bac, and GenBac) in 18 freshly deposited cattle feces from three farms in northern Georgia. Samples were randomly assigned to shaded or unshaded treatment in order to determine the effects of sunlight, moisture, and temperature on decay rates. A general linear model (GLM) framework was used to determine decay rates. Shading significantly decreased the decay rate of theE. colipopulation (P< 0.0001), with a rate of −0.176 day−1for the shaded treatment and −0.297 day−1for the unshaded treatment. Shading had no significant effect on decay rates of enterococci, CowM3, Rum-2-bac, and GenBac (P> 0.05). In addition,E. colipopulations showed a significant growth rate (0.881 day−1) in the unshaded samples during the first 5 days after deposition. UV-B was the most important parameter explaining the decay rate ofE. colipopulations. A comparison of the decay behaviors among all markers indicated that enterococcus concentrations exhibit a better correlation with the MST markers thanE. coliconcentrations. Our results indicate that bovine-associated MST markers can survive in cow pats for at least 1 month after excretion, and although their decay dynamic differs from the decay dynamic ofE. colipopulations, they seem to be reliable markers to use in combination with enterococci to monitor fecal pollution from pasture lands.


2018 ◽  
Vol 95 (1) ◽  
Author(s):  
Michael McTee ◽  
Lorinda Bullington ◽  
Matthias C Rillig ◽  
Philip W Ramsey

ABSTRACTMany experiments that measure the response of microbial communities to heavy metals increase metal concentrations abruptly in the soil. However, it is unclear whether abrupt additions mimic the gradual and often long-term accumulation of these metals in the environment where microbial populations may adapt. In a greenhouse experiment that lasted 26 months, we tested whether bacterial communities and soil respiration differed between soils that received an abrupt or a gradual addition of copper or no copper at all. Bacterial richness and other diversity indices were consistently lower in the abrupt treatment compared to the ambient treatment that received no copper. The abrupt addition of copper yielded different initial bacterial communities than the gradual addition; however, these communities appeared to converge once copper concentrations were approximately equal. Soil respiration in the abrupt treatment was initially suppressed but recovered after four months. Afterwards, respiration in both the gradual and abrupt treatments wavered between being below or equal to the ambient treatment. Overall, our study indicates that gradual and abrupt additions of copper can yield similar bacterial communities and respiration, but these responses may drastically vary until copper concentrations are equal.


Author(s):  
О. Lavrenchuk ◽  
І. Bagdasarova

The rapid growth of the acquired resistance of bacteria to antibacterial agents requires a revision of the selection ofempirical antimicrobial therapy in children with urinary tract infection (UTI). The aim of this work was to investigate the etiological structure of uropathogen flora and its sensitivity to nitrofurantoin and antibacterial drugs ofother classes in children with UTI in Kyiv and region. Materials and methods. Were examined in 95 children aged 3 to 17years in the aediatric Nephrology Department of, Institute of Nephrology NAMS of Ukraine” on the basis of clinical hospital №7 Kyiv city in 2015-2016. The disease duration ofthepatients rangedfrom 3 months to 4years. Results.The microbial spectrum of the urine depended on theform of pyelonephritis, but all patients were dominated by enterobacteria E. coli and Kl. pneumoniae. The greatest number of patients was resistant to ampicillin, co-trimoxazol and cefuroxime – 10.5% of patients with acute and 17.2% with chronic pyelonephritis. The highest sensitivity was preserved in all patients before medications meronem and gentamicin – 100% and 94.7%, respectively. Most children in Kyiv and Kyiv region showed a high sensitivity to nitrofurantoin:furamag – 78.9-75.8%,furagin - 63.8-65.5%. Comparative analysis of therapeutic efficiency of drugsfuramag and co-trimoxazol, demonstrated greater therapeutic efficacy of nitro- furans in the absence of recurrences, compared with co-trimoxazol (Oto 1.68withp=0.021). Conclusions. Among the causative agents of UTI in children of the city of Kyiv and Kyiv region was dominated by gram-negativeflora - E. coli and Kl. pneumoniae. High sensitivity to nitrofurantoin drugs, especiallyfuramag, cephalosporins, and gentamicin and meronem was documented. High rates of resistance to penicillin and co-trimoxazol was revealed. The use of the drugfuramag contributed to a more rapid, complete andpersistent normalization ofclinical and laboratory parameters in children with UTI.


Author(s):  
Amy A. O’Callaghan ◽  
Elaine Dempsey ◽  
Namrata Iyer ◽  
Sarah Stiegeler ◽  
Kevin Mercurio ◽  
...  

The metabolite-rich environment that is the intestinal lumen contains metabolic by-products deriving from microbial fermentation and host cell metabolism, with resident macrophages being constantly exposed to this metabolic flux. Succinate, lactate and itaconate are three metabolites secreted by primed macrophages due to a fragmented tri-carboxylic acid (TCA) cycle. Additionally, succinate and lactate are known by-products of microbial fermentation. How these metabolites impact biological functioning of resident macrophages particularly in response to bacterial infection remains poorly understood. We have investigated the potential influence of these metabolites on macrophage phagocytosis and clearance of Escherichia coli (E. coli) infection. Treatment of murine bone-marrow-derived macrophages (BMDMs) with succinate reduced numbers of intracellular E. coli early during infection, while lactate-treated BMDMs displayed no difference throughout the course of infection. Treatment of BMDMs with itaconate lead to higher levels of intracellular E. coli early in the infection with bacterial burden subsequently reduced at later time-points compared to untreated macrophages, indicative of enhanced engulfment and killing capabilities of macrophages in response to itaconate. Expression of engulfment mediators MARCKS, RhoB, and CDC42 were reduced or unchanged following succinate or lactate treatment and increased in itaconate-treated macrophages following E. coli infection. Nitric oxide (NO) levels varied while pro- and anti-inflammatory cytokines differed in secretory levels in all metabolite-treated macrophages post-infection with E. coli or in response to lipopolysaccharide (LPS) stimulation. Finally, the basal phenotypic profile of metabolite-treated macrophages was altered according to marker gene expression, describing how fluid macrophage phenotype can be in response to the microenvironment. Collectively, our data suggests that microbe- and host-derived metabolites can drive distinct macrophage functional phenotypes in response to infection, whereby succinate and itaconate regulate phagocytosis and bactericidal mechanisms, limiting the intracellular bacterial niche and impeding the pathogenesis of infection.


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