Colonization Density Research Articles

Tacrolimus ointment for children's atopic dermatitis and its influence on malassezia's colonization

Objectives To evaluate the influence of tacrolimus ointment on malassezia's colonization in the lesional areas of the children with atopic dermatitis (AD).Methods The children with AD were randomly divided into a treatment group and a control group.Both groups orally administered loratadine tablets.In addition,the treatment group were treated with 0.03％ tacrolimus ointment and the control group was given Vitamin E cream twice a day for 3 weeks.The SCORAD integral drop index was used to evaluate the efficacy.Values of SCORAD and malassezia colonization density were compared before,day 7,14,and 21 of,and 14 and 28 days after the treatment.Pearson correlation analysis was used to assess the dependability between malassezia colonization density and the severity of disease.Results The SCORAD value of the treatment group markedly decreased after the treatment.The efficacy rate was 95.65 ％ in treatment group and 66.67 ％ in the control group (P ＜ 0.05).28 days after the treatment,one case recurred and the efficacy rate was 91.30％ in the treatment group and 3 cases recurred and the efficacy rate was 50.00％ in the control group,with significant differences (P ＜ 0.05).There was no significant correlation between malassezia colonization density and SCORAD integral before and after the treatment.Day 7,14,and 21 of the treatment,Malassezia colonization densities were lower in the treatment group than in the control group(P ＜ 0.05).Conclusions 0.03％ tacrolimus ointment for children with AD is effective and safe,has a low recurrence rate,and can reduce the malassezia colonization density on the surface of lesional area. Key words: Atopic dermatitis; Tacrolimus; Malassezia; Colonization

Invasion by Two Plant Species Affects Fungal Root Colonizers

The effects of multiple invasive plants on soil fungal communities may impact native ecosystems differently than invasion by one species alone. Native plant communities are likely to have a differential above and below ground response to invaders, and therefore understanding fungal implications of invader interactions would be useful when considering restoration strategies. We examined how invasion by European species, Dog-strangling vine or DSV ( Vincetoxicum rossicum ) (also pale swallow-wort) and garlic mustard or GM ( Alliaria petiolata ), can alter root colonization by both the total and arbuscular mycorrhizal fungi. In two different sites in the Greater Toronto Area, we investigated fungal communities associated with each plant species in differing invasion scenarios using terminal restriction length polymorphism analysis. Fungal communities in DSV changed significantly in the presence of GM, with decreased colonization densities observed in both the total fungi (Student's t -test; t = 2.1, p = 0.02) and AMF communities (Student's t -test; t = 2.0, p = 0.03), as well as decreased overall phylotype richness of the total fungal communities associating with DSV growing in GM patches relative to those growing separately from GM in both sites (one-way ANOVA; F = 4.4, p = 0.02). The converse was not observed, suggesting that GM has the dominant effect on the invaded soil environment. These results suggest that multiple plant invaders influence the composition of soil fungi available to natives in a manner that is less predictable than invasion by a single species, possibly via increased carbon provision or antibiosis attributable to unique root exudates.

Combining self-assembling peptide gels with three-dimensional elastomer scaffolds

Some of the problems raised by the combination of porous scaffolds and self-assembling peptide (SAP) gels as constructs for tissue engineering applications are addressed for the first time. Scaffolds of poly(ethyl acrylate) and the SAP gel RAD16-I were employed. The in situ gelation of the SAP gel inside the pores of the scaffolds was studied. The scaffold-cum-gel constructs were characterized morphologically, physicochemically and mechanically. The possibility of incorporating an active molecule (bovine serum albumin, taken here as a model molecule for others) in the gel within the scaffold’s pores was assessed, and the kinetics of its release in phosphate-buffered saline was followed. Cell seeding and colonization of these constructs were preliminarily studied with L929 fibroblasts and subsequently checked with sheep adipose-tissue-derived stem cells intended for further preclinical studies. Static (conventional) and dynamically assisted seedings were compared for bare scaffolds and the scaffold-cum-gel constructs. The SAP gel inside the pores of the scaffold significantly improved the uniformity and density of cell colonization of the three-dimensional (3-D) structure. These constructs could be of use in different advanced tissue engineering applications, where, apart from a cell-friendly extracellular matrix -like aqueous environment, a larger-scale 3-D structure able to keep the cells in a specific place, give mechanical support and/or conduct spatially the tissue growth could be required.

Multiple Site Surveillance Cultures as a Predictor of Methicillin-Resistant Staphylococcus aureus Infections

To determine the relationship between methicillin-resistant Staphylococcus aureus (MRSA) colonization density, colonization site, and probability of infection in a frequently screened cohort of intensive care unit (ICU) patients. Patients had swab samples tested for MRSA at admission to the ICU, discharge from the ICU, and twice weekly during their ICU stay, and they were followed up for development of MRSA infection. Swab test results were analyzed to determine the proportion of patients colonized and the proportion colonized at each screening site. Hazard of MRSA infection (rate of infection per day at risk) was calculated using a Cox proportional hazards analysis, and risk factors for MRSA infection, including presence of MRSA, degree of colonization, and pattern of colonization were determined. Among the 4,194 patient episodes, 238 (5.7%) had screening results that were positive for MRSA, and there were 34 cases of MRSA infection. The hazard ratio (HR) for developing an infection increased as more sites were colonized (HR, 3.4 for being colonized at more than 1 site compared with colonization at 1 site [95% confidence interval, 1.2-9.9]). Colonization site was predictive of developing infection (HR for nose or throat colonization compared with no colonization, 168 [95% confidence interval, 69-407]). This study demonstrated that the hazard of developing an infection was higher when more sites were colonized and that certain sites were more predictive of infection than others. These results may be useful for predicting infection in ICU patients and may influence treatment.

Colonization pressure as a risk factor for colonization by multiresistant Acinetobacter spp and carbapenem-resistant Pseudomonas aeruginosa in an intensive care unit

OBJECTIVE:To determine factors associated with colonization by carbapenem-resistant Pseudomonas aeruginosa and multiresistant Acinetobacter spp.METHODS:Surveillance cultures were collected from patients admitted to the intensive care unit at admission, on the third day after admission and weekly until discharge. The outcome was colonization by these pathogens. Two interventions were implemented: education and the introduction of alcohol rubs. Compliance with hand hygiene, colonization pressure, colonization at admission and risk factors for colonization were evaluated.RESULTS:The probability of becoming colonized increased during the study. The incidence density of colonization by carbapenem-resistant P. aeruginosa and multiresistant Acinetobacter spp. and colonization pressure were different between periods, increasing gradually throughout the study. The increase in colonization pressure was due to patients already colonized at admission. The APACHE II score, colonization pressure in the week before the outcome and male gender were independent risk factors for colonization. Every 1% increase in colonization pressure led to a 2% increase in the risk of being colonized.CONCLUSION:Colonization pressure is a risk factor for carbapenem-resistant P. aeruginosa and multiresistant Acinetobacter spp. colonization. When this pressure reaches critical levels, efforts primarily aimed at hand hygiene may not be sufficient to prevent transmission.

CD4 T Cell Memory and Antibody Responses Directed against the Pneumococcal Histidine Triad Proteins PhtD and PhtE following Nasopharyngeal Colonization and Immunization and Their Role in Protection against Pneumococcal Colonization in Mice

The present study was undertaken to understand the role of vaccine candidates PhtD and PhtE in pneumococcal nasopharyngeal (NP) colonization, their ability to induce CD4 T cell memory and antibody responses following primary NP colonization, and their contribution to protection against secondary pneumococcal colonization in mice. The study was also aimed at understanding the potential of immunization with PhtD and PhtE in eliciting qualitative CD4 T cell memory responses and protection against pneumococcal NP colonization in mice. PhtD and PhtE isogenic mutants in a TIGR4 background (TIGR4 ΔPhtD and TIGR4 ΔPhtE) were constructed and found to have a significantly reduced colonization density over time in the nasopharynges of mice compared to those of mice colonized with wild-type TIGR4. Mice with primary colonization by wild-type TIGR4, TIGR4 ΔPhtD, or TIGR4 ΔPhtE were protected against secondary colonization by wild-type TIGR4; nonetheless, the clearance of secondary colonization was slower in mice with primary colonization by either TIGR4 ΔPhtD or TIGR4 ΔPhtE than in mice with primary colonization by wild-type TIGR4. Colonization was found to be an immunizing event for PhtD and PhtE antigens (antibody response); however, we failed to detect any antigen (PhtD or PhtE)-specific CD4 T cell responses in any of the colonized groups of mice. Intranasal immunization with either PhtD or PhtE protein generated robust serum antibody and CD4 Th1-biased immune memory and conferred protection against pneumococcal colonization in mice. We conclude that PhtD and PhtE show promise as components in next-generation pneumococcal vaccine formulations.

Native Predators Do Not Influence Invasion Success of Pacific Lionfish on Caribbean Reefs

Biotic resistance, the process by which new colonists are excluded from a community by predation from and/or competition with resident species, can prevent or limit species invasions. We examined whether biotic resistance by native predators on Caribbean coral reefs has influenced the invasion success of red lionfishes (Pterois volitans and Pterois miles), piscivores from the Indo-Pacific. Specifically, we surveyed the abundance (density and biomass) of lionfish and native predatory fishes that could interact with lionfish (either through predation or competition) on 71 reefs in three biogeographic regions of the Caribbean. We recorded protection status of the reefs, and abiotic variables including depth, habitat type, and wind/wave exposure at each site. We found no relationship between the density or biomass of lionfish and that of native predators. However, lionfish densities were significantly lower on windward sites, potentially because of habitat preferences, and in marine protected areas, most likely because of ongoing removal efforts by reserve managers. Our results suggest that interactions with native predators do not influence the colonization or post-establishment population density of invasive lionfish on Caribbean reefs.

Field Evaluation of Culture plus Latex Sweep Serotyping for Detection of Multiple Pneumococcal Serotype Colonisation in Infants and Young Children

BackgroundNasopharyngeal swab (NPS) culture by World Health Organisation (WHO) methodology underestimates multiple pneumococcal serotype colonisation compared to a simple culture and latex sweep method. The impacts of this on descriptions of pneumococcal serotype distributions and colonisation dynamics in infancy are not clear.Methods8,736 NPS collected from infants enrolled into a longitudinal study were processed to evaluate the field utility of the latex sweep method. 1,107 had previously been cultured by WHO methodology. Additionally, colonisation results were compared in 100 matched pairs of infants, where swabs from an individual were cultured either by WHO or latex sweep method.ResultsIn 1,107 swabs cultured by both methods, the latex sweep method was three times more likely to detect colonisation with multiple pneumococcal serotypes than the WHO method (p<0.001). At least one common serotype was identified in 91.2% of swabs from which typeable pneumococci were detected by both methods. Agreement improved with increasing colonisation density (p = 0.03). Estimates of age at first pneumococcal acquisition and colonisation duration were not affected by culture/serotyping method. However, a greater number of serotype carriage episodes were detected in infants cultured by latex sweep (p = 0.03). The overall rate of non-vaccine type pneumococcal acquisition was also greater in infants cultured by latex sweep (p = 0.04).ConclusionsLatex sweep serotyping was feasible to perform on a large specimen collection. Multiple serotype colonisation detection was significantly improved compared with WHO methodology. However, use of the latex sweep method is unlikely to significantly alter colonisation study serotype distribution or colonisation dynamics results.

Oropharyngeal Colonization Density of Kingella kingae

To the Editors: The pathogenesis of Kingella kingae invasive infections remains unclear, even if there is evidence that K. kingae first colonizes the oropharynx before penetrating the bloodstream and invading distant organs.1 The density of the oropharyngeal carriage may thus be suspected to play a role in the pathogenesis of invasive K. kingae infections, as it is the case with many other pathogens of the oropharyngeal flora, such as Streptococcus pneumoniae or Haemophilus influenzae.2–7 In the current study, we explored whether there was a modification in the density of K. kingae oropharyngeal bacterial load that might modify the risk of invasive infections during the first years of life in children. We quantified the oropharyngeal colonization density of 117 positive oropharyngeal swabs, analyzed with a rtPCR assay targeting the toxin-encoding gene rtxB. As we have previously demonstrated that there is no difference in the density of oropharyngeal K. kingae colonization between children with osteoarticular infections and asymptomatic carriers,8 throat swabs of all children were considered together. All participants’ parents provided written consent, and the protocol was approved by the institutional ethics committee. For baseline characteristics, variables are reported as mean ± standard deviation. Pearson coefficient was used to establish correlation between continuous variables. Between January 2008 and December 2012, 117 children with positive K. kingae rtPCR assays on oropharyngeal swabs were included and investigated in this study (71 asymptomatic oropharyngeal carriers and 46 children with suspected or proven osteoarticular infections due to K. kingae). The mean age of the children was 22.8 ± 10.1 months (range: 8-48 months). The oropharyngeal colonization density was estimated by the number of cycles needed to detect the DNA target. The mean number of cycles for detection was 33 ± 4.5 cycles. The Pearson’s correlation coefficient (r) between oropharyngeal colonization density and age of the children was –0.050 (P = 0.592), demonstrating no statistically significant correlation between the 2 variables (Fig. 1). Similarly to S. pneumoniae, H. influenzae type b or Neisseria meningitidis, K. kingae resides in the mucosal surface and is able to penetrate the bloodstream, disseminate and invade distant organs.9–11 Colonization of the respiratory tracts by these organisms is, therefore, a prerequisite for later invasion. For most of these microoorganisms, such as S. pneumoniae or H. influenzae,2–7 there are evidences that the bacterial load varies in the nasopharynx with the age of subjects, and that higher nasopharynx colonization densities play major roles in the development of invasive infections.2–7 For K. kingae, there are currently no data about the K. kingae oropharyngeal colonization density during the first years of life. This study is thus the first, to the best of our knowledge, to demonstrate that the pharyngeal colonization density is very stable during the first 4 years of life, and that this parameter must thus play a minor role in the development of invasive infection. In conclusion, the density of the K. kingae oropharyngeal carriage does not vary during the first 4 years of life and seems thus to play no role in the development of invasive infections, as it is the case with many other pathogens present in oropharyngeal flora, such as S. pneumoniae or H. influenzae. Dimitri Ceroni, MD Victor Dubois-Ferriere, MD Rebecca Anderson Della Llana, MD Pediatric Orthopedic Service University Hospitals of Geneva Omar Kherad, MD Internal Medicine Department University of Geneva Hôpital de la Tour Pierre Lascombes, MD Pediatric Orthopedic Service University Hospitals of Geneva Gesuele Renzi, MD Clinical Microbiology Laboratory Service of Infectious Diseases University Hospitals of Geneva Sergio Manzano, MD Pediatric Emergency Division University Hospitals of Geneva Abdessalam Cherkaoui, PhD Clinical Microbiology Laboratory Service of Infectious Diseases University Hospitals of Geneva Jacques Schrenzel, MD Clinical Microbiology Laboratory Genomic Research Laboratory Service of Infectious Diseases University Hospitals of Geneva Geneva, Switzerland

Investigation of fungal root colonizers of the invasive plant Vincetoxicum rossicum and co-occurring local native plants in a field and woodland area in Southern Ontario

Fungal communities forming associations with plant roots have generally been described as ranging from symbiotic to parasitic. Disruptions to these associations consequently can have significant impacts on native plant communities. We examined how invasion by Vincetoxicum rossicum, a plant native to Europe, can alter both the arbuscular mycorrhizal fungi, as well as the general fungal communities associating with native plant roots in both field and woodland sites in Southern Ontario. In two different sites in the Greater Toronto Area, we took advantage of invasion by V. rossicum and neighbouring uninvaded sites to investigate the fungal communities associating with local plant roots, including goldenrod (Solidago spp.), wild red raspberry (Rubus idaeus), Canada anemone (Anemone canadensis), meadow rue (Thalictrum dioicum), and wild ginger (Asarum canadense). Fungi colonizing roots were characterized with terminal restriction fragment length polymorphism (T-RFLP) analysis of amplified total fungal (TF) and arbuscular mycorrhizal fungal (AMF) ribosomal fragments. We saw a significant effect of the presence of this invader on the diversity of TF phylotypes colonizing native plant roots, and a composition shift of both the TF and AMF community in native roots in both sites. In native communities invaded by V. rossicum, a significant increase in richness and colonization density of TF suggests that invaders such as V. rossicum may be able to influence the composition of soil fungi available to natives, possibly via mechanisms such as increased carbon provision or antibiosis attributable to unique root exudates. Nature Conservation 4: 55–75 (2013) doi: 10.3897/natureconservation.4.3578 http://www.pensoft.net/natureconservation Copyright Cindy L. Bongard et al. This is an open access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. ReSeARCh ARtICle Launched to accelerate biodiversity conservation A peer-reviewed open-access journal

Acetaldehyde production and microbial colonization in oral squamous cell carcinoma and oral lichenoid disease

The main aim of this prospective study was to explore the ability of the oral microbiome to produce acetaldehyde in ethanol incubation. A total of 90 patients [30 oral squamous cell carcinoma (OSCC); 30 oral lichenoid disease (OLD); 30 healthy controls (CO)] were enrolled in the study. Microbial samples were taken from the mucosa using a filter paper method. The density of microbial colonization was calculated and the spectrum analyzed. Microbial acetaldehyde production was measured by gas chromatography. The majority (68%) of cultures produced carcinogenic levels of acetaldehyde (>100 μM) when incubated with ethanol (22 mM). The mean acetaldehyde production by microbes cultured from smoker samples was significantly higher (213 μM) than from non-smoker samples (141 μM) (P=.0326). The oral microbiota from OSCC, OLD patients and healthy individuals are able to produce carcinogenic levels of acetaldehyde. The present provisional study suggests smoking may increase the production of acetaldehyde.

Log colonization by Ips sexdentatus prevented by increasing host unsuitability signaled by verbenone

AbstractSudden increments of breeding material after windstorms, forest fires, or inappropriate management practices help bark beetles such as Ips sexdentatus Boerner (Coleoptera: Curculionidae: Scolytinae) increase in numbers and colonize standing healthy pine trees. Preventing bark beetles from arriving to susceptible trees or logs may have great relevance for bark beetle management. Recent studies have reported inhibition of the aggregation response of I. sexdentatus using verbenone. Two field experiments were conducted to examine the effect of verbenone on the colonization pattern of this beetle. The first experiment tested the combined effect of trans‐conophthorin, a non‐host bark volatile with known repellent effect, and verbenone on Pinus sylvestris L. (Pinaceae) log piles of two sizes, but failed to protect them against I. sexdentatus attack when these two infochemicals were released at low rates. The results of this experiment suggested an interaction with the associated secondary bark beetle Orthotomicus erosus (Wollaston). A second experiment examined the response of I. sexdentatus and O. erosus to log piles that released verbenone at 0, 2, 10, or 40 mg day−1. Although I. sexdentatus colonization of Pinus nigra Arnold logs was completely prevented at 40 mg day−1, O. erosus could be found at all tested verbenone release rates. Besides verbenone, O. erosus colonization density and the height from which logs originated were the variables that best explained I. sexdentatus log colonization pattern. In addition, I. sexdentatus and O. erosus were rarely recorded colonizing the same log, and niche breadth analyses suggested that they excluded each other. The role of verbenone in the colonization process and its potential use in the prevention of population buildups of damaging bark beetles such as I. sexdentatus are discussed.

Assessment of remnant unionid assemblages in a selection of Great Lakes coastal wetlands

Populations of native unionids have been in steady decline over the past century. The invasion of dreissenid mussels (Dreissena polymorpha and Dreissena rostriformis bugensis) in the mid-1980's impacted already imperiled unionid populations by greatly increasing their regional extinction rates. A selection of Great Lakes coastal wetlands around Michigan was surveyed to locate remnant populations of native unionids. Physical and chemical parameters were measured in coastal wetlands to evaluate the importance of these habitat parameters to remnant unionid assemblages. We assessed fouling rates by dreissenids on unionids and used artificial substrates to estimate dreissenid colonization densities. Live unionids were found in coastal wetlands of the Les Cheneaux Islands, the Lake St. Clair delta, and North Maumee Bay with significantly higher unionid fouling in the Les Cheneaux Islands compared to the other two sampling areas (F2,76=4.97, p=0.0095). No live unionids were documented in Beaver Island, Garden Island, Grand Traverse Bay, or Saginaw Bay wetlands. Dreissena colonization densities on artificial substrates averaged 19,213m−2 at one site in North Maumee Bay, and 10,425m−2 in Saginaw Bay, but no colonization occurred in the wetlands of Beaver Island, Garden Island, the Les Cheneaux Islands, or Grand Traverse Bay while Dreissena presence in the open water of these regions was evident. Dreissena colonization densities on artificial substrates increased with measures of anthropogenic disturbance and decreased with higher water level fluctuations and aerial exposure. Specific conductance, turbidity, and magnitude of water level fluctuations were important predictors of Dreissena colonization on artificial substrates.

Ocorrência e atividade de fungos micorrízicos arbusculares em plantios de eucalipto (eucalyptus sp.) no litoral norte da Bahia, Brasil

Nas últimas décadas, tecnologias alternativas vêm sendo estudadas visando tornar o cultivo do eucalipto (Eucalyptus sp.) mais econômico e sustentável. Entre estas, as associações micorrízicas merecem destaque devido aos inúmeros benefícios que proporcionam às plantas hospedeiras. Este trabalho teve como objetivo avaliar a ocorrência e atividade de fungos micorrízicos arbusculares em plantios de eucalipto utilizados comercialmente pela Copener Florestal Ltda. no litoral norte da Bahia. Foi observada grande variabilidade na densidade de esporos (36,2 a 203,2 esporos em 50 g de solo), colonização micorrízica (10,6 a 57,8%) e nos teores de glomalina facilmente extraível e total (0,34 a 1,92 mg g de solo-1 e 0,48 a 3,88 mg g de solo-1) nos plantios de eucalipto. Os resultados neste estudo permitiram concluir que, embora os clones apresentem suscetibilidade à micorrização em condições de campo, variações nas características do solo afetam aspectos ecológicos dos fungos micorrízicos arbusculares nos plantios de eucalipto da Copener Florestal Ltda. no litoral norte da Bahia.

Triatoma dimidiata (Latreille) Abundance and Infection with Trypanosoma cruzi in a Rural Community of Yucatan, Mexico

The present is a longitudinal study that describes the abundance of Triatoma dimidiata (Latreille) (Hemiptera: Reduviidae) and its infection with Trypanosoma cruzi in a rural community of Yucatan, Mexico. From a total of 370 individuals collected, 81.3% were adults, most from intradomicile ecotope (282/301), but nymphs were more abundant in peridomicile (58/69). The overall proportion of infected bugs was 21.9% (23.9% of adults and 13% of nymphs). The infection proportion was similar between intradomicile and peridomicile ecotopes (22.8% and 18.1%, respectively). Overall, 76.5% (36/47) of the houses and their backyards were infested. Of those, 27.7% were colonized and 75% had infected triatomines. Our data showed different proportions on infestation, colonization and bug density. Ninety-seven percent of overall peridomicile abundance was distributed in chicken coops, doghouses, opossum nests and dove cages. Triatomine entomological indices showed higher infestation and density inside domiciles, but higher colonization in the peridomicile. The abundance, the amount of infected intradomicile adult T. dimidiata and the incidence of infestation showed a seasonal pattern, with 63.7% of all individuals collected during the late dry season (April to June). We showed the peridomicile colonization of animal shelters and suggest it as a relevant source of T. dimidiata individuals. As infected bugs were found in both ecotopes, the studied area is under a high risk of T. cruzi transmission to humans.

Relationships Between Rhinitis Symptoms, Respiratory Viral Infections and Nasopharyngeal Colonization With Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus in Children Attending Daycare

Nasal bacterial colonization is often dubbed "asymptomatic." We hypothesized that rhinitis, common in preschool children, is associated with bacterial colonization and that respiratory viruses, which cause rhinitis, interact with bacteria in ways which promote transmission. Five hundred eighty-five children (4.2-73.6 months) attending daycare had clinical information, a rhinitis score and nasal swabs collected in February 2009. Swabs in soya tryptone glucose glycerine broth were cultured for Streptococcus pneumoniae (Sp), Haemophilus influenzae (Hi) and Staphylococcus aureus and analyzed by real-time polymerase chain reaction for respiratory viruses, both semiquantitatively. Rhinitis symptoms, carriage of Sp and Hi and viral detection fell, whereas S. aureus carriage rates rose with age. Significant, age-independent associations between rhinitis symptoms and detection of Hi (P < 0.033) and Hi colonization density (P < 0.027) were observed. Of the 42% with detected viruses, most (78%) had picornavirus detection. There was a significant age-independent association between viral detection (and viral load, picornavirus detection and picorn aviral load) and detection of Sp (P = 0.020, 0.035, 0.005, 0.014) and between viral detection and viral load and Sp colonization density (P = 0.024, 0.028) [corrected]. Hi may promote its own transmission by inducing or ampli¬fying rhinitis in children. There isa close quantitative relationship between respiratory viral detection, including picornavirus detection and Spcoloni¬zation. These findings have implications for understanding disease patho¬genesis and formulating prevention strategies using vaccines [corrected].

Bile Acids as Modulators of Gut Microbiota Linking Dietary Habits and Inflammatory Bowel Disease: A Potentially Dangerous Liaison

Bile Acids as Modulators of Gut Microbiota Linking Dietary Habits and Inflammatory Bowel Disease: A Potentially Dangerous Liaison

Biodiversity of Arbuscular Mycorrhizal (AM) fungi in mangroves of Goa in West India

Seventeen mangrove species of eight families at seven riverine and fringe habitats in Goa West India were surveyed for Arbuscular Mycorrhizal (AM) fungal diversity. Sixteen species were found to be mycorrhizal and one species showed no AM fungal colonization. AM root colonization was recorded at all seven sites and ranged from 6%–77%. Maximum root colonization was recorded in Excoecaria agallocha (77%) and minimum colonization in Avicennia marina (6%). Paris-type colonization was predominant at all sites. Auxiliary cells were recorded in roots of Acanthus ilicifolius, Ceriops tagal and Sonneretia alba. AM fungal root colonization and spore density varied by plant species and site. Site average spore density ranged from 1.84 spores·g−1 to 0.54 spores·g−1 of soil. In total, 28 AM fungal species of five genera, viz. Glomus, Acaulospora, Scutellospora, Gigaspora and Entrophospora, were recovered. Glomus was the dominant genus, three species of which were sporocarpic forms. Maximum site species richness (SR) ranged from 16 to 5. Species richness was maximum in A. ilicifolius where seven species of three genera were recovered. Based on relative abundance (RA) and isolation frequency (IF), two common species, viz. G. intraradices and A. laevis, were recovered from all seven sites.

Intestinal Microbiota Containing Barnesiella Species Cures Vancomycin-Resistant Enterococcus faecium Colonization

Bacteria causing infections in hospitalized patients are increasingly antibiotic resistant. Classical infection control practices are only partially effective at preventing spread of antibiotic-resistant bacteria within hospitals. Because the density of intestinal colonization by the highly antibiotic-resistant bacterium vancomycin-resistant Enterococcus (VRE) can exceed 10(9) organisms per gram of feces, even optimally implemented hygiene protocols often fail. Decreasing the density of intestinal colonization, therefore, represents an important approach to limit VRE transmission. We demonstrate that reintroduction of a diverse intestinal microbiota to densely VRE-colonized mice eliminates VRE from the intestinal tract. While oxygen-tolerant members of the microbiota are ineffective at eliminating VRE, administration of obligate anaerobic commensal bacteria to mice results in a billionfold reduction in the density of intestinal VRE colonization. 16S rRNA gene sequence analysis of intestinal bacterial populations isolated from mice that cleared VRE following microbiota reconstitution revealed that recolonization with a microbiota that contains Barnesiella correlates with VRE elimination. Characterization of the fecal microbiota of patients undergoing allogeneic hematopoietic stem cell transplantation demonstrated that intestinal colonization with Barnesiella confers resistance to intestinal domination and bloodstream infection with VRE. Our studies indicate that obligate anaerobic bacteria belonging to the Barnesiella genus enable clearance of intestinal VRE colonization and may provide novel approaches to prevent the spread of highly antibiotic-resistant bacteria.

Causes, consequences, and perspectives in the variations of intestinal density of colonization of multidrug-resistant enterobacteria

The intestinal microbiota is a complex environment that hosts 1013 to 1014 bacteria. Among these bacteria stand multidrug-resistant enterobacteria (MDRE), which intestinal densities can substantially vary, especially according to antibiotic exposure. The intestinal density of MDRE and their relative abundance (i.e., the proportion between the density of MDRE and the density of total enterobacteria) could play a major role in the infection process or patient-to-patient transmission. This review discusses the recent advances in understanding (i) what causes variations in the density or relative abundance of intestinal colonization, (ii) what are the clinical consequences of these variations, and (iii) what are the perspectives for maintaining these markers at low levels.