ResearchPad - gut-bacteria https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Broilers divergently selected for digestibility differ for their digestive microbial ecosystems]]> https://www.researchpad.co/article/elastic_article_15757 Improving the digestive efficiency of broiler chickens (Gallus gallus) could reduce organic waste, increase the use of alternative feed not used for human consumption and reduce the impact of feed in production costs. By selecting chicken lines divergently for their digestive efficiency, we showed previously that digestive efficiency is under genetic control and that the two resulting divergent lines, D+ (high digestive efficiency or “digestibility +”) and D- (low digestive efficiency or “digestibility -”), also differ for the abundance of specific bacteria in their caeca. Here we perform a more extensive census of the bacteria present in the digestive microbiota of 60 chickens selected for their low apparent metabolizable energy corrected for nitrogen balance (AMEn-) or high (AMEn+) digestive efficiency in a [D+ x D-] F8 progeny of 200 individuals. We sequenced the 16S rRNA genes of the ileal, jejunal and caecal microbiotas, and compared the compositions and predicted functions of microbiotas from the different intestinal segments for 20 AMEn+ and 19 AMEn- birds. The intestinal segment of origin was the main factor structuring the samples. The caecal microbiota was the most impacted by the differences in digestive efficiency, with 41 bacterial species with abundances differing between highly and poorly efficient birds. Furthermore, we predicted that the caecal microbiota of efficient birds might be enriched in genes contributing to the degradation of short chain fatty acids (SCFA) from non-starch polysaccharides. These results confirm the impact of the genetic selection led on digestibility on the caecal microbiota taxonomic composition. They open the way toward the identification of specific, causal genes of the host controlling variations in the abundances of bacterial taxons.

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<![CDATA[<i>Escherichia coli</i> ST131 clones harbouring AggR and AAF/V fimbriae causing bacteremia in Mozambican children: Emergence of new variant of <i>fimH27</i> subclone]]> https://www.researchpad.co/article/elastic_article_14507 Escherichia coli ST131 has emerged as a globally disseminated multi-drug resistant clone associated with extra-intestinal infections acquired in the community or hospital. In Manhiça district, E. coli is among the top five leading bloodstream pathogens in children. We characterized E. coli strains causing bacteremia in young children in a rural hospital of Mozambique, providing novel information on the occurrence of a new subclone of ST131 harboring both ExPEC and EAEC related genes and belonging to commonly reported O25:H4 and other serotypes. These data suggest the need for further understanding of pathogenesis and clinical impact of this new entity to inform prompt recognition and appropriate treatment.

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<![CDATA[Anti-cancer effects of <i>Bifidobacterium</i> species in colon cancer cells and a mouse model of carcinogenesis]]> https://www.researchpad.co/article/elastic_article_14495 Probiotics are suggested to prevent colorectal cancer (CRC). This study aimed to investigate the anticancer properties of some potential probiotics in vitro and in vivo.Materials and methodsAnticancer effects of potential probiotic groups were investigated following of in LS174T cancer cells compared to IEC-18 normal cells. 1. a single strain of Bifidobacterium. breve, 2. a single strain of Lactobacillus. reuteri, 3. a cocktail of 5 strains of Lactobacilli (LC), 4. a cocktail of 5 strains of Bifidobacteria (BC), 5. a cocktail of 10 strains from Lactobacillus and Bifidobacterium (L+B). Apoptosis rate, EGFR, HER-2 and PTGS-2 (COX-2 protein) expression levels were assessed as metrics of evaluating anticancer properties. Effect of BC, as the most effective group in vitro, was further assessed in mice models.ResultsBC induced ~21% and only ~3% apoptosis among LS174T and IEC-18 cells respectively. BC decreased the expression of EGFR by 4.4 folds, HER-2 by 6.7 folds, and PTGS-2 by 20 folds among the LS174T cells. In all these cases, BC did not interfere significantly with the expression of the genes in IEC-18 cells. This cocktail has caused only 1.1 folds decrease, 1.8 folds increase and 1.7 folds decrease in EGFR, HER-2 and PTGS-2 expression, respectively. Western blot analysis confirmed these results in the protein level. BC significantly ameliorated the disease activity index, restored colon length, inhibited the increase in incidence and progress of tumors to higher stages and grades.ConclusionsBC was the most efficient treatment in this study. It had considerable “protective” anti-cancer properties and concomitantly down regulated EGFR, HER-2 and PTGS-2 (COX-2), while having significant anti-CRC effects on CRC mice models. In general, this potential probiotic could be considered as a suitable nutritional supplement to treat and prevent CRC. ]]> <![CDATA[A prospective study of bloodstream infections among febrile adolescents and adults attending Yangon General Hospital, Yangon, Myanmar]]> https://www.researchpad.co/article/elastic_article_13833 Bloodstream infection (BSI) is common among persons seeking healthcare for severe febrile illness in low-and middle-income countries. Data on community-onset BSI are few for some countries in Asia, including Myanmar. Such data are needed to inform empiric antimicrobial treatment of patients and to monitor and control antimicrobial resistance. We performed a one year, prospective study collecting information and blood cultures from patients presenting with fever at a tertiary referral hospital in Yangon, Myanmar. We found that almost 10% of participants had a bloodstream infection, and that Salmonella enterica serovars Typhi and Paratyphi A were the most common pathogens. Typhoidal Salmonella were universally resistant to ciprofloxacin. More than half of Escherichia coli and Klebsiella pneumoniae were resistant to extended-spectrum cephalosporins and resistance to carbapenems was also identified in some isolates. We show that typhoid and paratyphoid fever are common, and fluoroquinolone resistance is widespread. Extended-spectrum cephalosporin resistance is common in E. coli and K. pneumoniae and carbapenem resistance is present. Our findings inform empiric antimicrobial management of severe febrile illness, underscore the value of routine use of blood cultures, indicate that measures to prevent and control enteric fever are warranted, and suggest a need to monitor and mitigate antimicrobial resistance among community-acquired pathogens.

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<![CDATA[Instigation of indigenous thermophilic bacterial consortia for enhanced oil recovery from high temperature oil reservoirs]]> https://www.researchpad.co/article/elastic_article_13812 The purpose of the study involves the development of an anaerobic, thermophilic microbial consortium TERIK from the high temperature reservoir of Gujarat for enhance oil recovery. To isolate indigenous microbial consortia, anaerobic baltch media were prepared and inoculated with the formation water; incubated at 65°C for 10 days. Further, the microbial metabolites were analyzed by gas chromatography, FTIR and surface tension. The efficiency of isolated consortia towards enhancing oil recovery was analyzed through core flood assay. The novelty of studied consortia was that, it produces biomass (600 mg/l), bio-surfactant (325 mg/l), and volatile fatty acids (250 mg/l) at 65°C in the span of 10 days, that are adequate to alter the surface tension (70 to 34 mNm -1) and sweep efficiency of zones facilitating the displacement of oil. TERIK was identified as Clostridium sp. The FTIR spectra of biosurfactant indicate the presence of N-H stretch, amides and polysaccharide. A core flooding assay was designed to explore the potential of TERIK towards enhancing oil recovery. The results showed an effective reduction in permeability at residual oil saturation from 2.14 ± 0.1 to 1.39 ± 0.05 mD and 19% incremental oil recovery.

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<![CDATA[Lean back and wait for the alarm? Testing an automated alarm system for nosocomial outbreaks to provide support for infection control professionals]]> https://www.researchpad.co/article/N4571fdc0-2a2e-4467-acc9-eeadc2652757

Introduction

Outbreaks of communicable diseases in hospitals need to be quickly detected in order to enable immediate control. The increasing digitalization of hospital data processing offers potential solutions for automated outbreak detection systems (AODS). Our goal was to assess a newly developed AODS.

Methods

Our AODS was based on the diagnostic results of routine clinical microbiological examinations. The system prospectively counted detections per bacterial pathogen over time for the years 2016 and 2017. The baseline data covers data from 2013–2015. The comparative analysis was based on six different mathematical algorithms (normal/Poisson and score prediction intervals, the early aberration reporting system, negative binomial CUSUMs, and the Farrington algorithm). The clusters automatically detected were then compared with the results of our manual outbreak detection system.

Results

During the analysis period, 14 different hospital outbreaks were detected as a result of conventional manual outbreak detection. Based on the pathogens’ overall incidence, outbreaks were divided into two categories: outbreaks with rarely detected pathogens (sporadic) and outbreaks with often detected pathogens (endemic). For outbreaks with sporadic pathogens, the detection rate of our AODS ranged from 83% to 100%. Every algorithm detected 6 of 7 outbreaks with a sporadic pathogen. The AODS identified outbreaks with an endemic pathogen were at a detection rate of 33% to 100%. For endemic pathogens, the results varied based on the epidemiological characteristics of each outbreak and pathogen.

Conclusion

AODS for hospitals based on routine microbiological data is feasible and can provide relevant benefits for infection control teams. It offers in-time automated notification of suspected pathogen clusters especially for sporadically occurring pathogens. However, outbreaks of endemically detected pathogens need further individual pathogen-specific and setting-specific adjustments.

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<![CDATA[In vitro and ex vivo evaluation of the anti-Giardia duodenalis activity of the supernatant of Slab51 (SivoMixx)]]> https://www.researchpad.co/article/5c8acce0d5eed0c4849901f8

The effects on Giardia duodenalis of Slab51 probiotic supernatants were evaluated in vitro and ex vivo. In vitro, Slab51 (101 UFC) was cultured and the obtained supernatant was filtered, adjusted at pH 7, and added (100μl/ml) as such (Slab51 FS) or after heat-treatment, to G. duodenalis cultures to evaluate its effects on G. duodenalis trophozoites growth and adherence. For comparison, negative and metronidazole (20μg/ml) treated controls were used. The morphological and ultrastructural alterations of G. duodenals trophozoites following treatment with Slab51 FS supernatant were investigated by transmission electron microscopy. Ex vivo, mice duodenal portions were cultivated in standard conditions with 5x105 G. duodenalis trophozoites/ml, while to further five duodenal portions similarly cultured and infected, Slab51 FS 200μl was added. After 12 and 18h, samples were fixed in 10% buffered formalin and histologically processed to score Giardia infection and cell damage. Cell proliferation/apoptosis was scored by Ki67, TUNEL and Caspase–3 tests. All experiments were conducted in triplicate throughout the study. All data were statistically evaluated (P< 0.05). Results showed that Slab51 FS significantly reduced Giardia growth and adherence respect to negative controls, but its efficacy was overall lower than that of metronidazole. Moreover, the effects of Slab51 FS were significantly lowered by heat-treatment and this reduction was statistically higher at 90°C than at 56°C, indicating a heat-sensitive nature of active Slab51 FS compounds. At the ultrastructural level, Slab51 FS treated Giardia trophozoites were swelling, increased in size and showed alterations of their cellular membrane and vacuole patterns, loss of the nuclear envelope and nuclear architecture. In ex vivo trials, viable G. duodenalis trophozoites and enterocyte TUNEL+ and Caspase-3 expression were significantly reduced in intestinal sections added with Slab51 FS, while enterocyte Ki67 expression was significantly increased, confirming the anti-G. duodenalis activity of Slab51 FS observed in vitro. In conclusion, results from this study showed that the fresh culture supernatant of the commercial probiotic Slab51 has anti-G. duodenalis properties both in vitro and ex vivo in a mouse model.

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<![CDATA[Contact with adult hen affects development of caecal microbiota in newly hatched chicks]]> https://www.researchpad.co/article/5c8977aad5eed0c4847d32a0

Chickens in commercial production are hatched in a clean hatchery environment in the absence of any contact with adult hens. However, Gallus gallus evolved to be hatched in a nest in contact with an adult hen which may act as a donor of gut microbiota. In this study, we therefore addressed the issue of microbiota development in newly hatched chickens with or without contact with an adult hen. We found that a mere 24-hour-long contact between a hen and newly hatched chickens was long enough for transfer of hen gut microbiota to chickens. Hens were efficient donors of Bacteroidetes and Actinobacteria. However, except for genus Faecalibacterium and bacterial species belonging to class Negativicutes, hens did not act as an important source of Gram-positive Firmicutes. Though common to the chicken intestinal tract, Lactobacilli and isolates from families Erysipelotrichaceae, Lachnospiraceae and Ruminococcaceae therefore originated from environmental sources instead of from the hens. These observation may have considerable consequences for the evidence-based design of the new generation of probiotics for poultry.

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<![CDATA[Composition of gut microbiota in patients with toxigenic Clostridioides (Clostridium) difficile: Comparison between subgroups according to clinical criteria and toxin gene load]]> https://www.researchpad.co/article/5c76fe10d5eed0c484e5b3f2

Data concerning the human microbiota composition during Clostridioides (Clostridium) difficile infection (CDI) using next-generation sequencing are still limited. We aimed to confirm key features indicating tcdB positive patients and compare the microbiota composition between subgroups based on toxin gene load (tcdB gene) and presence of significant diarrhea. Ninety-nine fecal samples from 79 tcdB positive patients and 20 controls were analyzed using 16S rRNA gene sequencing. Chao1 index for alpha diversity were calculated and principal coordinate analysis was performed for beta diversity using Quantitative Insights into Microbial Ecology (QIIME) pipeline. The mean relative abundance in each group was compared at phylum, family, and genus levels. There were significant alterations in alpha and beta diversity in tcdB positive patients (both colonizer and CDI) compared with those in the control. The mean Chao1 index of tcdB positive patients was significantly lower than the control group (P<0.001), whereas there was no significant difference between tcdB groups and between colonizer and CDI. There were significant differences in microbiota compositions between tcdB positive patients and the control at phylum, family, and genus levels. Several genera such as Phascolarctobacterium, Lachnospira, Butyricimonas, Catenibacterium, Paraprevotella, Odoribacter, and Anaerostipes were not detected in most CDI cases. We identified several changes in the microbiota of CDI that could be further evaluated as predictive markers. Microbiota differences between clinical subgroups of CDI need to be further studied in larger controlled studies.

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<![CDATA[Salmonella-vectored vaccine delivering three Clostridium perfringens antigens protects poultry against necrotic enteritis]]> https://www.researchpad.co/article/5c6c75ddd5eed0c4843d0359

Necrotic enteritis is an economically important poultry disease caused by the bacterium Clostridium perfringens. There are currently no necrotic enteritis vaccines commercially available for use in broiler birds, the most important target population. Salmonella-vectored vaccines represent a convenient and effective option for controlling this disease. We used a single attenuated Salmonella vaccine strain, engineered to lyse within the host, to deliver up to three C. perfringens antigens. Two of the antigens were toxoids, based on C. perfringens α-toxin and NetB toxin. The third antigen was fructose-1,6-bisphosphate aldolase (Fba), a metabolic enzyme with an unknown role in virulence. Oral immunization with a single Salmonella vaccine strain producing either Fba, α-toxoid and NetB toxoid, or all three antigens, was immunogenic, inducing serum, cellular and mucosal responses against Salmonella and the vectored C. perfringens antigens. All three vaccine strains were partially protective against virulent C. perfringens challenge. The strains delivering Fba only or all three antigens provided the best protection. We also demonstrate that both toxins and Fba are present on the C. perfringens cell surface. The presence of Fba on the cell surface suggests that Fba may function as an adhesin.

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<![CDATA[Carriage and colonization of C. difficile in preterm neonates: A longitudinal prospective study]]> https://www.researchpad.co/article/5c76fe0ed5eed0c484e5b398

Background

Premature neonates (PN) present multiple risk factors for high frequencies and high levels of colonization by C. difficile, yet data is missing about this specific pediatric population. Here, we investigated PN C. difficile carriage and colonization dynamics, analyzed the impact of perinatal determinants on colonization, and characterized the isolates.

Methods

A one year longitudinal monocentric prospective cohort study was performed on 121 PN. C. difficile strains isolated from fecal samples on selective medium were identified and characterized by PCR (tpi housekeeping gene; tcdA and tcdB, and binary toxin genes), capillary gel-based electrophoresis PCR-ribotyping, and Multi-Locus Variable-number tandem-repeat Analysis (MLVA).

Results

Of the 379 samples analyzed, 199 (52%) were C. difficile culture positive with the mean levels of C. difficile colonization decreasing significantly (P = .027) over time. During hospitalization, C. difficile colonization frequency increased up to 61% with 95% of the strains belonging to both non-toxigenic PCR-ribotypes (RTs) FR082 (35%) and 032 (60%). After hospital discharge, if a higher diversity in RTs was observed, RTs FR082 and 032 remained predominant (respectively 40% and 28%). MLVA showed clonal relationship within each FR082 and 032 RTs. Ten toxigenic strains (5%) were isolated, all tcdA+/tcdB+ except for one tcdA-/tcdB+, and all being acquired after hospitalization. At 1 week, the only factors found to be linked with a higher frequency of C. difficile colonization were a higher gestational age (P = 0.006) and a higher birth weight (P = 0.016).

Conclusion

The dynamics of C. difficile colonization in PN followed a specific pattern. C. difficile colonization rapidly occurred after birth with a low diversity of non-toxigenic RTs. After hospitalization, non-toxigenic RTs diversity increased. Sporadic carriage of toxigenic strains was observed after hospitalization.

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<![CDATA[Evidence of transmission of Clostridium difficile in asymptomatic patients following admission screening in a tertiary care hospital]]> https://www.researchpad.co/article/5c6b262bd5eed0c4842894b4

Background

Clostridium difficile (CD) is the leading cause of infectious health-care associated diarrhea. However, little is known regarding CD carriage and transmission amongst asymptomatic colonizers. We evaluated carriage, characterized strains and examined epidemiologic linkages in asymptomatic colonized CD patients.

Methods

Rectal swabs from asymptomatic patients admitted to the general medicine ward from April 1-June 30 2012 were collected. PCR-confirmed CD colonies were ribotyped and characterized by Modified-Multi Locus Variable Number Tandem Repeat Analysis (MMLVA).

Results

1549-swabs were collected from 474-patients. Overall, 50/474(10.6%) were CD PCR-positive, 24/50 were colonized at admission, while 26/50 were first identified > = 72 hours after admission. Amongst the 50 CD PCR-positive patients, 90% were asymptomatically colonized and 80% of individuals carried toxigenic CD-strains, including ribotype-027 (5/45:11%). MMLVA revealed five-clusters involving 15-patients harboring toxigenic (4/5) and non-toxigenic CD strains (1/5). In two clusters, patients were CD positive on admission while in the other three clusters involving 10 patients, we observed CD transmission from asymptomatically colonized patients to 8 previously CD-negative patients.

Conclusions

We identified increasing rates of colonization during admission to medical wards. MMLVA typing effectively discriminated between strains and suggests that 20% of patients with CD colonization acquired their strain(s) from asymptomatically colonized individuals in hospital.

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<![CDATA[Social dynamics modeling of chrono-nutrition]]> https://www.researchpad.co/article/5c5b52b1d5eed0c4842bce5a

Gut microbiota and human relationships are strictly connected to each other. What we eat reflects our body-mind connection and synchronizes with people around us. However, how this impacts on gut microbiota and, conversely, how gut bacteria influence our dietary behaviors has not been explored yet. To quantify the complex dynamics of this interplay between gut and human behaviors we explore the “gut-human behavior axis” and its evolutionary dynamics in a real-world scenario represented by the social multiplex network. We consider a dual type of similarity, homophily and gut similarity, other than psychological and unconscious biases. We analyze the dynamics of social and gut microbial communities, quantifying the impact of human behaviors on diets and gut microbial composition and, backwards, through a control mechanism. Meal timing mechanisms and “chrono-nutrition” play a crucial role in feeding behaviors, along with the quality and quantity of food intake. Considering a population of shift workers, we explore the dynamic interplay between their eating behaviors and gut microbiota, modeling the social dynamics of chrono-nutrition in a multiplex network. Our findings allow us to quantify the relation between human behaviors and gut microbiota through the methodological introduction of gut metabolic modeling and statistical estimators, able to capture their dynamic interplay. Moreover, we find that the timing of gut microbial communities is slower than social interactions and shift-working, and the impact of shift-working on the dynamics of chrono-nutrition is a fluctuation of strategies with a major propensity for defection (e.g. high-fat meals). A deeper understanding of the relation between gut microbiota and the dietary behavioral patterns, by embedding also the related social aspects, allows improving the overall knowledge about metabolic models and their implications for human health, opening the possibility to design promising social therapeutic dietary interventions.

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<![CDATA[Impact of CodY protein on metabolism, sporulation and virulence in Clostridioides difficile ribotype 027]]> https://www.researchpad.co/article/5c5b52e7d5eed0c4842bd237

Toxin synthesis and endospore formation are two of the most critical factors that determine the outcome of infection by Clostridioides difficile. The two major toxins, TcdA and TcdB, are the principal factors causing damage to the host. Spores are the infectious form of C. difficile, permit survival of the bacterium during antibiotic treatment and are the predominant cell form that leads to recurrent infection. Toxin production and sporulation have their own specific mechanisms of regulation, but they share negative regulation by the global regulatory protein CodY. Determining the extent of such regulation and its detailed mechanism is important for understanding the linkage between two apparently independent biological phenomena and raises the possibility of creating new ways of limiting infection. The work described here shows that a codY null mutant of a hypervirulent (ribotype 027) strain is even more virulent than its parent in a mouse model of infection and that the mutant expresses most sporulation genes prematurely during exponential growth phase. Moreover, examining the expression patterns of mutants producing CodY proteins with different levels of residual activity revealed that expression of the toxin genes is dependent on total CodY inactivation, whereas most sporulation genes are turned on when CodY activity is only partially diminished. These results suggest that, in wild-type cells undergoing nutrient limitation, sporulation genes can be turned on before the toxin genes.

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<![CDATA[Evolutionary dynamics of bacteria in the gut microbiome within and across hosts]]> https://www.researchpad.co/article/5c521828d5eed0c4847975dd

Gut microbiota are shaped by a combination of ecological and evolutionary forces. While the ecological dynamics have been extensively studied, much less is known about how species of gut bacteria evolve over time. Here, we introduce a model-based framework for quantifying evolutionary dynamics within and across hosts using a panel of metagenomic samples. We use this approach to study evolution in approximately 40 prevalent species in the human gut. Although the patterns of between-host diversity are consistent with quasi-sexual evolution and purifying selection on long timescales, we identify new genealogical signatures that challenge standard population genetic models of these processes. Within hosts, we find that genetic differences that accumulate over 6-month timescales are only rarely attributable to replacement by distantly related strains. Instead, the resident strains more commonly acquire a smaller number of putative evolutionary changes, in which nucleotide variants or gene gains or losses rapidly sweep to high frequency. By comparing these mutations with the typical between-host differences, we find evidence that some sweeps may be seeded by recombination, in addition to new mutations. However, comparisons of adult twins suggest that replacement eventually overwhelms evolution over multi-decade timescales, hinting at fundamental limits to the extent of local adaptation. Together, our results suggest that gut bacteria can evolve on human-relevant timescales, and they highlight the connections between these short-term evolutionary dynamics and longer-term evolution across hosts.

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<![CDATA[Association between vaginal washing and vaginal bacterial concentrations]]> https://www.researchpad.co/article/5c536b0ad5eed0c484a47f26

Vaginal washing is a common practice associated with adverse outcomes including bacterial vaginosis (BV) and HIV infection. Prior studies have not examined the associations between vaginal washing and individual vaginal bacteria, or whether these associations are independent of the effect of vaginal washing on BV. The purpose of this study was to characterize the association between vaginal washing and the presence and concentrations of vaginal bacteria associated with optimal and sub-optimal vaginal states. The analysis utilized data from participants in the placebo arm of the Preventing Vaginal Infections trial, which enrolled HIV-uninfected women from the United States and Kenya. Detection of bacterial taxa associated with BV was compared between visits with versus without reported vaginal washing. The effect of vaginal washing on a number of vaginal bacteria differed substantially (p<0.05) between the US and Kenya, so results were stratified by country. In US women, vaginal washing was associated with a significantly higher likelihood of detection of BV associated bacterium 1 (BVAB1) (relative risk [RR] 1.55, 95% confidence interval [CI] 1.15–2.09, p = 0.004), BVAB2 (RR 1.99, 95%CI 1.46–2.71, p<0.001), Mageeibacillus indolicus (RR 2.08, 95%CI 1.46–2.96, p<0.001), Atopobium vaginae (RR 1.34, 95%CI 1.13–1.59, p = 0.001), Leptotrichia/Sneathia species (RR 1.66, 95% CI 1.33–2.09, p<0.001), Megasphaera species (RR 1.78, 95%CI 1.34–2.37, p<0.001) and Gardnerella vaginalis (RR 1.08, 95%CI 1.01–1.16, p = 0.02). No significant association between vaginal washing and bacterial detection was found in Kenyan women. Adjustment for bacterial vaginosis diagnosed by Gram stain did not alter these results. This study provides evidence that the association between vaginal washing and detection of individual bacterial taxa can vary regionally. For some vaginal bacteria, the association with vaginal washing may be independent of the effect on Gram stain detection of BV. Larger prospective studies in diverse geographic settings should explore whether eliminating vaginal washing impacts the presence and concentrations of key vaginal bacteria.

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<![CDATA[Fecal microbiota transplantation for treatment of recurrent C. difficile infection: An updated randomized controlled trial meta-analysis]]> https://www.researchpad.co/article/5c5217d8d5eed0c4847946a2

Objectives

Although systematic evaluation has confirmed the efficacy of fresh fecal microbiota transplantation (FMT) for treatment of recurrent and/or refractory and/or relapse C. difficile infection (RCDI), it lacks the support of well-designed randomized controlled trials (RCTs), and the latest guidelines do not optimize the management of FMT. In this paper, we focus on an in-depth study of fresh FMT and fecal infusion times to guide clinical practice.

Methods

We reviewed studies in PubMed, Medline, Embase, the Cochrane library and Cochrane Central written in English. The retrieval period was from the establishment of the databases to September 20th, 2018. The retrieval objects were published RCTs of RCDI treated by fresh FMT. The intervention group was fresh FMT group, while the control group included antibiotic therapy or placebo or frozen FMT or capsule. The primary and secondary outcomes were the clinical remission of diarrhea without relapse after 8–17 weeks and the occurrence of severe adverse events, respectively. Subgroup analysis analyzed the effect of single and multiple fecal infusions. Two authors independently completed the information extraction and assessed risk of bias and overall quality of the evidence.

Results

8 randomized controlled trials met the inclusion criteria, involving 537 patients (273 in the fresh FMT group and 264 in the control group). The recurrence rate of clinical diarrhea in the fresh FMT group was 11.0% (30/273), which was significantly lower than the control group (24.6%, 65/264; P < 0.05); the pooled relative risk (RR) was 0.38 (95%CI:0.16–0.87; I2 = 67%; P = 0.02) in the fresh FMT group, and the clinical heterogeneity was significant and random effects model was used; However, there was no significant difference neither for the effect of antibiotic treatment/frozen feces transplanted by enema (RR = 1.07; 95%CI: 0.64–1.80; I2 = 0%; P = 0.79) or capsule/frozen feces transplanted by colonoscopy (RR = 0.42; 95%CI: 0.05–3.94; I2 = 43%; P = 0.45) compared with fresh FMT. The subgroup analysis showed that FMT by multiple infusions could effectively and significantly (RR = 0.24; 95%CI:0.10–0.58; I2 = 0%; P = 0.001) improve the clinical diarrhea remission rate. Most mild to moderate adverse events caused by FMT were self-limited and could be quickly alleviated; no severe adverse events happened because of FMT.

Conclusions

Overall, the use of fresh feces for bacterial transplantation was the best efficiency for RCDI compared to antibiotic therapy or placebo. The fecal transmission method by enema was not ideal, but capsules or frozen feces transported by colonoscopy could be an alternative treatment compared to fresh FMT. For patients with severe RCDI, multiple fecal transplants can effectively improve their diarrhea remission rate. The focus of future research should be on how to standardize the production of capsules or frozen feces to better guide the clinical management of RCDI patients by FMT.

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<![CDATA[Diarrheal bacterial pathogens and multi-resistant enterobacteria in the Choqueyapu River in La Paz, Bolivia]]> https://www.researchpad.co/article/5c46656bd5eed0c484519147

Water borne diarrheal pathogens might accumulate in river water and cause contamination of drinking and irrigation water. The La Paz River basin, including the Choqueyapu River, flows through La Paz city in Bolivia where it is receiving sewage, and residues from inhabitants, hospitals, and industry. Using quantitative real-time PCR (qPCR), we determined the quantity and occurrence of diarrheagenic Escherichia coli (DEC), Salmonella enterica, Klebsiella pneumoniae, Shigella spp. and total enterobacteria in river water, downstream agricultural soil, and irrigated crops, during one year of sampling. The most abundant and frequently detected genes were gapA and eltB, indicating presence of enterobacteria and enterotoxigenic E. coli (ETEC) carrying the heat labile toxin, respectively. Pathogen levels in the samples were significantly positively associated with high water conductivity and low water temperature. In addition, a set of bacterial isolates from water, soil and crops were analyzed by PCR for presence of the genes blaCTX-M, blaKPC, blaNDM, blaVIM and blaOXA-48. Four isolates were found to be positive for blaCTX-M genes and whole genome sequencing identified them as E. coli and one Enterobacter cloacae. The E. coli isolates belonged to the emerging, globally disseminated, multi-resistant E. coli lineages ST648, ST410 and ST162. The results indicate not only a high potential risk of transmission of diarrheal diseases by the consumption of contaminated water and vegetables but also the possibility of antibiotic resistance transfer from the environment to the community.

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<![CDATA[Effect of ZFN-edited myostatin loss-of-function mutation on gut microbiota in Meishan pigs]]> https://www.researchpad.co/article/5c478c68d5eed0c484bd2230

Intestine contains the body's second largest genetic information, so a relatively stable microbiota ecosystems and interactions between intestinal micro-organisms play a pivotal role in the normal growth and development in animals. The establishment of intestinal microflora is affected by a variety of factors such as species, environmental factors, developmental stage, organizational structure and physiological characteristics of various parts of the digestive tract. Gene editing technology such as ZFN has recently been used as a new approach to replace the traditional transgenic technology and to make genetic modifications in animals. However, it is not known if genetic modification by gene editing technology will have any impact on gut microbiota. In this study, by sequencing 16S rRNA collected from rectum, we investigated the effects of ZFN-mediated myostatin (MSTN) loss-of-function mutation (MSTN-/-) on gut microbiota in Meishan pigs. Our results showed that the fecal microbial composition is very similar between MSTN-/- Meishan pigs and wild type Meishan pigs. Although significant differences in certain individual strains were observed, all the dominant microorganism species are basically the same between MSTN-/- and wild type pigs. However, these differences do not adversely affect MSTN-/- Meishan pigs. Thus, it is concluded that ZFN-mediated MSTN loss-of-function mutation did not have any adverse effect on the gut microbiota in Meishan pigs.

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<![CDATA[A cross-sectional study on the prevalence of antibiotic use prior to laboratory tests at two Ghanaian hospitals]]> https://www.researchpad.co/article/5c478c46d5eed0c484bd141b

There has been a significant rise in global antibiotic use in recent years. Development of resistance has been linked to easy accessibility, lack of regulation of sale, increased tendency to self-medicate and the lack of public knowledge. The increase in antibiotic misuse, including self-medication, has not been well documented in developing countries. Antibiotic use prior to visiting health facilities has been found to be prevalent in developing countries. It has been identified by some studies to increase the likelihood of missed diagnoses and influence the outcome of bacteriological tests. This study is aimed at determining the prevalence of prior antibiotic use through a cross-sectional survey of patients undergoing laboratory tests at two health facilities in Ghana. Face-to-face questionnaires were used to interview 261 individuals chosen by random sampling of patients visiting the bacteriology laboratory of the hospitals within a two-month period. The questionnaire investigated participant demographic characteristics, knowledge about antibiotics and the nature of antibiotic use. Antibiotic property detection bioassay was performed on patient’s urine sample using a disk diffusion method to accurately determine antibiotic use within 72 hours. Culture results were used as an index to evaluate the effect of prior antibiotic use on bacteriological tests. Out of a 261 participants enrolled, 19.9% (95% CI, 14.9–24.9) acknowledged using antibiotics prior to their visit to the laboratory during the study period. On the contrary, 31.4% (95% CI, 25.7–37.5) of participants’ urine samples were positive for antimicrobial activity. Participants within the age ranges of 20–30, 31–40 and 41–50 years had significantly lower odds of urine antimicrobial activity. Participants who had urine antimicrobial activity were more likely to have no growth on their culture plates than participants who had no urine antimicrobial activity [OR 2.39(1.37–4.18), p = 0.002]. The most commonly used antibiotics were the penicillins, fluoroquinolones and metronidazole. Although, majority of the participant (54.8%) had knowledge of antibiotics, most of them had inadequate information on their proper use. The commonest indications for antibiotic use were aches and pains (30.3%), diarrhoea (43.3%) and urinary tract infections (28.0%). Prior antibiotic use was found to increase the likelihood of obtaining a culture negative result and can affect the outcome of bacteriological tests.

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