Probiotic
strains had been investigated for the potential to protect against infection caused by the major fungal pathogen of human,
. Besides antifungal activity, lactobacilli demonstrated a ...promising inhibitory effect on biofilm formation and filamentation of
. On the other hand, two commonly isolated non-albicans
species,
and
, have similar characteristics in filamentation and biofilm formation with
. However, there is scant information of the effect of lactobacilli on the two species.
In this study, biofilm inhibitory effects of
ATCC 53103,
ATCC 8014, and
ATCC 4356 were tested on the reference strain
SC5314 and six bloodstream isolated clinical strains, two each of
,
, and
.
Cell-free culture supernatants (CFSs) of
and
significantly inhibited
biofilm growth of
and
.
, conversely, had little effect on
and
but was more effective on inhibiting
biofilms. Neutralized
CFS at pH 7 retained the inhibitory effect, suggesting that exometabolites other than lactic acid produced by the
strain might be accounted for the effect. Furthermore, we evaluated the inhibitory effects of
and
CFSs on the filamentation of
and
strains. Significantly less
filaments were observed after co-incubating with CFSs under hyphae-inducing conditions. Expressions of six biofilm-related genes (
,
,
,
,
, and
in
and corresponding orthologs in
) in biofilms co-incubated with CFSs were analyzed using quantitative real-time PCR. When compared to untreated control, the expressions of
,
,
, and
genes were downregulated in
biofilm. In
biofilms,
and
were downregulated while
was upregulated. Taken together, the
and
strains demonstrated an inhibitory effect, which is likely mediated by the metabolites secreted into culture medium, on filamentation and biofilm formation of
and
. Our finding suggested an alternative to antifungals for controlling
biofilm.
Fecal microbiota transplant (FMT) has emerged as a potential treatment for severe colitis associated with graft-versus-host disease (GvHD) following hematopoietic stem cell transplant. Bacterial ...engraftment from FMT donor to recipient has been reported, however the fate of fungi and viruses after FMT remains unclear. Here we report longitudinal dynamics of the gut bacteriome, mycobiome and virome in a teenager with GvHD after receiving four doses of FMT at weekly interval. After serial FMTs, the gut bacteriome, mycobiome and virome of the patient differ from compositions before FMT with variable temporal dynamics. Diversity of the gut bacterial community increases after each FMT. Gut fungal community initially shows expansion of several species followed by a decrease in diversity after multiple FMTs. In contrast, gut virome community varies substantially over time with a stable rise in diversity. The bacterium, Corynebacterium jeikeium, and Torque teno viruses, decrease after FMTs in parallel with an increase in the relative abundance of Caudovirales bacteriophages. Collectively, FMT may simultaneously impact on the various components of the gut microbiome with distinct effects.
Proper preservation of stool samples to minimize microbial community shifts and inactivate infectious agents is important for self-collected specimens requiring shipment to laboratories when cold ...chain transport is not feasible. In this study, we evaluated the performance of six preservation solutions (Norgen, OMNI, RNAlater, CURNA, HEMA, and Shield) for these aspects. Following storage of human stool samples with these preservatives at room temperature for 7 days, three hypervariable regions of the bacterial 16S rRNA gene (V1-V2, V3-V4, and V4) were amplicon sequenced. We found that samples collected in two preservatives, Norgen and OMNI, showed the least shift in community composition relative to -80°C standards compared with other storage conditions, and both efficiently inhibited the growth of aerobic and anaerobic bacteria. RNAlater did not prevent bacterial activity and exhibited relatively larger community shift. Although the effect of preservation solution was small compared to intersubject variation, notable changes in microbiota composition were observed, which could create biases in downstream data analysis. When community profiles inferred from different 16S rRNA gene hypervariable regions were compared, we found differential sensitivity of primer sets in identifying overall microbial community and certain bacterial taxa. For example, reads generated by the V4 primer pair showed a higher alpha diversity of the gut microbial community. The degenerate 27f-YM primer failed to detect the majority of
. Our data indicate that choice of preservation solution and 16S rRNA gene primer pair are critical determinants affecting gut microbiota profiling.
Large-scale human microbiota studies require specimens collected from multiple sites and/or time points to maximize detection of the small effects in microbe-host interactions. However, batch biases caused by experimental protocols, such as sample collection, massively parallel sequencing, and bioinformatics analyses, remain critical and should be minimized. This work evaluated the effects of preservation solutions and bacterial 16S rRNA gene primer pairs in revealing human gut microbiota composition. Since notable changes in detecting bacterial composition and abundance were observed among choice of preservatives and primer pairs, a consistent methodology is essential in minimizing their effects to facilitate comparisons between data sets.
Studies on the microbial communities in non-human primate hosts provide unique insights in both evolution and function of microbes related to human health and diseases. Using 16S rRNA gene amplicon ...profiling, we examined the oral, anal and vaginal microbiota in a group of non-captive rhesus macaques (N = 116) and compared the compositions with the healthy communities from Human Microbiome Project. The macaque microbiota was dominated by Bacteroidetes, Firmicutes and Proteobacteria; however, there were marked differences in phylotypes enriched across body sites indicative of strong niche specialization. Compared to human gut microbiota where Bacteroides predominately enriched, the surveyed macaque anal community exhibited increased abundance of Prevotella. In contrast to the conserved human vaginal microbiota extremely dominated by Lactobacillus, the macaque vaginal microbial composition was highly diverse while lactobacilli were rare. A constant decrease of the vaginal microbiota diversity was observed among macaque samples from juvenile, adult without tubectomy, and adult with tubectomy, with the most notable distinction being the enrichment of Halomonas in juvenile and Saccharofermentans in contracepted adults. Both macaque and human oral microbiota were colonized with three most common oral bacterial genera: Streptococcus, Haemophilus and Veillonella, and shared relatively conserved communities to each other. A number of bacteria related to human pathogens were consistently detected in macaques. The findings delineate the range of structure and diversity of microbial communities in a wild macaque population, and enable the application of macaque as an animal model for future characterization of microbes in transmission, genomics and function.
A zinc(II) phthalocyanine substituted with a triamino moiety and its tri-N-methylated analogue have been prepared and characterized with various spectroscopic methods. Both compounds remain ...non-aggregated in N,N-dimethylformamide and in water containing 0.05% Cremophor EL (v/v), and can generate singlet oxygen effectively. The photodynamic activities of these compounds have been examined against a range of bacterial strains, including the Gram-positive methicillin-sensitive Staphylococcus aureus ATCC 25923 and methicillin-resistant Staphylococcus aureus ATCC BAA-43, and the Gram-negative Escherichia coli ATCC 35218 and Pseudomonas aeruginosa ATCC 27853. Both photosensitizers are highly cytotoxic, particularly for the two Gram-positive strains, for which as low as 5 nM of dye is required to induce a 4-log reduction of their viability. The tri-N-methylated derivative has also been shown to be able to effectively inhibit the growth of a series of clinical strains of Staphylococcus aureus and Escherichia coli, and biofilms of methicillin-resistant Staphylococcus aureus ATCC 67928 and ATCC 68507, and Staphylococcus epidermidis ATCC 35984. In addition, the photodynamic inactivation of a range of viruses using these two compounds has also been investigated. Both compounds are highly photocytotoxic against the enveloped viruses influenza A virus (H1N1) and herpes simplex virus type 1 (HSV1), but exhibit no significant cytotoxicity toward the non-enveloped viruses adenovirus type 3 (Ad3) and coxsackievirus (Cox B1).
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•Two zinc(II) phthalocyanines were prepared as photosensitizers for antimicrobial PDT.•They are highly photocytotoxic toward a range of bacterial strains and viruses.•Only 5 nM of dye is required to induce a 4-log reduction of the bacterial viability.•Their photodynamic action can extend to several methicillin-resistant strains.•They exhibit no significant cytotoxicity toward non-enveloped viruses.
To estimate the prevalence and attribution of two non-vaccine-covered HPV types (HPV52 and HPV58) across the world.
Meta-analysis on studies reported in English and Chinese between 1994 and 2012.
The ...pooled prevalence and attribution rates of HPV52 and HPV58 in invasive cervical cancers were significantly higher in Eastern Asia compared to other regions (HPV52 prevalence: 5.7% vs. 1.8-3.6%, P<0.001; HPV52 attribution: 3.7% vs. 0.2-2.0%; HPV58 prevalence: 9.8% vs. 1.1-2.5%, P<0.001; HPV58 attribution: 6.4% vs. 0.7-2.2%, P<0.001). Oceania has an insufficient number of studies to ascertain the prevalence of HPV52. Within Eastern Asia, the attribution of HPV58 to invasive cervical cancer was 1.8-fold higher than that of HPV52. Similarly, HPV52 and HPV58 shared a higher prevalence and attribution among cervical intraepithelial neoplasia in Eastern Asia. In contrast to the classical high-risk type, HPV16, the prevalence and attribution of HPV52 and HPV58 decreased with increasing lesion severity. Thus, HPV52 and HPV58 behave as an "intermediate-risk" type.
The attribution of HPV52 and HPV58 to cervical intraepithelial neoplasia and invasive cancer in Eastern Asia were respectively 2.5-2.8 and 3.7-4.9 folds higher than elsewhere. Changes in the attributed disease fraction can serve as a surrogate marker for cross-protection or type replacement following widespread use of HPV16/18-based vaccines. This unique epidemiology should be considered when designing HPV screening assays and vaccines for Eastern Asia.
Limited data is available on the epidemiology and characteristics of carbapenem-resistant
(CRE) and their associated plasmids or virulence determinants from Sri Lanka. Through whole genome sequencing ...of CREs from the intensive care units of a Sri Lankan teaching hospital, we identified a carbapenemase gene,
in 10 carbapenemase-producing
isolates (two strains of ST437 and eight strains of ST147) from 379 respiratory specimens.
was carried in three variants of ColE-type plasmids.
strains with
variants showed high minimum inhibitory concentrations to carbapenem. Furthermore, genes encoding for extended spectrum β-lactamases (ESBL), plasmid-mediated quinolone resistance (PMQR) determinants (
,
, and
) were present in all 10 strains. Amino acid substitution in chromosomal quinolone resistance-determining regions (QRDRs)
(Ser83Ile) and
(Ser80Ile) were also observed. All strains had yersiniabactin genes on mobile element ICE
. Strict infection control practices and judicious use of antibiotics are warranted to prevent further spread of multidrug-resistant
.
► Human cathelicidin LL37 and its fragments LL13-37 and LL17-32 inhibited HIV-1 reverse transcriptase dose-dependently with an IC50 value of 15
μM, 7
μM, and 70
μM, respectively. ► Human cathelicidin ...LL37 and its fragments LL13-37 and LL17-32 inhibited HIV-1 protease with a weak potency. ► The peptides did not exert toxicity on human peripheral blood mononuclear cells.
Cathelicidins exhibit anti-HIV activity but it is not known if they reduce the activity of enzymes crucial to the life cycle of the retrovirus. It is shown in this investigation that human cathelicidin LL37 and its fragments LL13-37 and LL17-32 inhibited HIV-1 reverse transcriptase dose-dependently with an IC50 value of 15
μM, 7
μM, and 70
μM, respectively. The three peptides inhibited HIV-1 protease with a weak potency, achieving 20–30% inhibition at 100
μM. The mechanism of inhibition was protein–protein interaction as revealed by surface plasmon resonance. The peptides were devoid of the ability to inhibit translocation of HIV-1 integrase, which has been labeled with green fluorescent protein, into the nucleus. The peptides did not exert toxicity on human peripheral blood mononuclear cells.
Microbial culture-based investigations of inflamed tonsil tissues have previously indicated enrichment of several microorganisms such as Streptococcus, Staphylococcus and Prevotella. These taxa were ...also largely reflected in DNA sequencing studies performed using tissue material. In comparison, less is known about the response of the overall oral cavity microbiota to acute tonsillitis despite their role in human health and evidence showing that their compositions are correlated with diseases such as oral cancers. In addition, the influence of subject-specific circumstances including consumption of prescription antibiotics and smoking habits on the microbiology of acute tonsillitis is unknown.
We collected oral rinse samples from 43 individuals admitted into hospital for acute tonsillitis and 165 non-disease volunteers recruited from the public, and compared their microbial community compositions using 16S rRNA gene sequencing. We assessed the impact of tonsillitis, whether subjects were prescribed antibiotics, the presence of oral abscesses and their smoking habits on community composition, and identified specific microbial taxa associated with tonsillitis and smoking.
Oral rinse community composition was primarily associated with disease state (tonsillitis vs non-tonsillitis) although its effect was subtle, followed by smoking habit. Multiple Prevotella taxa were enriched in tonsillitis subjects compared to the non-tonsillitis cohort, whereas the non-tonsillitis cohort primarily showed associations with several Neisseria sequence variants. The presence of oral abscesses did not significantly influence community composition. Antibiotics were prescribed to a subset of individuals in the tonsillitis cohort but we did not observe differences in community composition associated with antibiotics consumption. In both tonsillitis and non-tonsillitis cohorts, smoking habit was associated with enrichment of several Fusobacterium variants.
These findings show that the oral cavity microbial community is altered during acute tonsillitis, with a consistent enrichment of Prevotella during tonsillitis raising the possibility of targeted interventions. It also supports the possible link between smoking, Fusobacteria and oral cancers.
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