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1.
PLoS One ; 14(5): e0215945, 2019.
Article in English | MEDLINE | ID: mdl-31042762

ABSTRACT

The composition of the vaginal microbiome, including both the presence of pathogens involved in sexually transmitted infections (STI) as well as commensal microbiota, has been shown to have important associations for a woman's reproductive and general health. Currently, healthcare providers cannot offer comprehensive vaginal microbiome screening, but are limited to the detection of individual pathogens, such as high-risk human papillomavirus (hrHPV), the predominant cause of cervical cancer. There is no single test on the market that combines HPV, STI, and microbiome screening. Here, we describe a novel inclusive vaginal health assay that combines self-sampling with sequencing-based HPV detection and genotyping, vaginal microbiome analysis, and STI-associated pathogen detection. The assay includes genotyping and detection of 14 hrHPV types, 5 low-risk HPV types (lrHPV), as well as the relative abundance of 31 bacterial taxa of clinical importance, including Lactobacillus, Sneathia, Gardnerella, and 3 pathogens involved in STI, with high sensitivity, specificity, and reproducibility. For each of these taxa, reference ranges were determined in a group of 50 self-reported healthy women. The HPV sequencing portion of the test was evaluated against the digene High-Risk HPV HC2 DNA test. For hrHPV genotyping, agreement was 95.3% with a kappa of 0.804 (601 samples); after removal of samples in which the digene hrHPV probe showed cross-reactivity with lrHPV types, the sensitivity and specificity of the hrHPV genotyping assay were 94.5% and 96.6%, respectively, with a kappa of 0.841. For lrHPV genotyping, agreement was 93.9% with a kappa of 0.788 (148 samples), while sensitivity and specificity were 100% and 92.9%, respectively. This novel assay could be used to complement conventional cervical cancer screening, because its self-sampling format can expand access among women who would otherwise not participate, and because of its additional information about the composition of the vaginal microbiome and the presence of pathogens.


Subject(s)
Microbiota , Papillomaviridae/genetics , Papillomavirus Infections/diagnosis , Sexually Transmitted Diseases/diagnosis , Vagina/virology , Adolescent , Adult , Capsid Proteins/genetics , DNA, Viral/genetics , DNA, Viral/isolation & purification , Female , Gardnerella/genetics , Gardnerella/isolation & purification , Genotype , Humans , Lactobacillus/genetics , Lactobacillus/isolation & purification , Limit of Detection , Middle Aged , Oncogene Proteins, Viral/genetics , Papillomaviridae/isolation & purification , Papillomavirus Infections/virology , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 16S/metabolism , Reproducibility of Results , Sensitivity and Specificity , Sexually Transmitted Diseases/virology , Vagina/microbiology , Young Adult
2.
Front Microbiol ; 10: 60, 2019.
Article in English | MEDLINE | ID: mdl-30761108

ABSTRACT

Extreme acidophiles play central roles in the geochemical cycling of diverse elements in low pH environments. This has been harnessed in biotechnologies such as biomining, where microorganisms facilitate the recovery of economically important metals such as gold. By generating both extreme acidity and a chemical oxidant (ferric iron) many species of prokaryotes that thrive in low pH environments not only catalyze mineral dissolution but also trigger both community and individual level adaptive changes. These changes vary in extent and direction depending on the ore mineralogy, water availability and local climate. The use of indigenous versus introduced microbial consortia in biomining practices is still a matter of debate. Yet, indigenous microbial consortia colonizing sulfidic ores that have been domesticated, i.e., selected for their ability to survive under specific polyextreme conditions, are claimed to outperform un-adapted foreign consortia. Despite this, little is known on the domestication of acidic microbial communities and the changes elicited in their members. In this study, high resolution targeted metagenomic techniques were used to analyze the changes occurring in the community structure of local microbial consortia acclimated to growing under extreme acidic conditions and adapted to endure the conditions imposed by the target mineral during biooxidation of a gold concentrate in an airlift reactor over a period of 2 years. The results indicated that operative conditions evolving through biooxidation of the mineral concentrate exerted strong selective pressures that, early on, purge biodiversity in favor of a few Acidithiobacillus spp. over other iron oxidizing acidophiles. Metagenomic analysis of the domesticated consortium present at the end of the adaptation experiment enabled reconstruction of the RVS1-MAG, a novel representative of Acidithiobacillus ferrooxidans from the Andacollo gold mineral district. Comparative genomic analysis performed with this genome draft revealed a net enrichment of gene functions related to heavy metal transport and stress management that are likely to play a significant role in adaptation and survival to adverse conditions experienced by these acidophiles during growth in presence of gold concentrates.

3.
Front Public Health ; 6: 77, 2018.
Article in English | MEDLINE | ID: mdl-29686981

ABSTRACT

In most industrialized countries, screening programs for cervical cancer have shifted from cytology (Pap smear or ThinPrep) alone on clinician-obtained samples to the addition of screening for human papillomavirus (HPV), its main causative agent. For HPV testing, self-sampling instead of clinician-sampling has proven to be equally accurate, in particular for assays that use nucleic acid amplification techniques. In addition, HPV testing of self-collected samples in combination with a follow-up Pap smear in case of a positive result is more effective in detecting precancerous lesions than a Pap smear alone. Self-sampling for HPV testing has already been adopted by some countries, while others have started trials to evaluate its incorporation into national cervical cancer screening programs. Self-sampling may result in more individuals willing to participate in cervical cancer screening, because it removes many of the barriers that prevent women, especially those in low socioeconomic and minority populations, from participating in regular screening programs. Several studies have shown that the majority of women who have been underscreened but who tested HPV-positive in a self-obtained sample will visit a clinic for follow-up diagnosis and management. In addition, a self-collected sample can also be used for vaginal microbiome analysis, which can provide additional information about HPV infection persistence as well as vaginal health in general.

4.
Stand Genomic Sci ; 12: 84, 2017.
Article in English | MEDLINE | ID: mdl-29270251

ABSTRACT

10.1601/nm.2199 CLST is an extremely acidophilic gamma-proteobacteria that was isolated from the Gorbea salt flat, an acidic hypersaline environment in northern Chile. This kind of environment is considered a terrestrial analog of ancient Martian terrains and a source of new material for biotechnological applications. 10.1601/nm.2199 plays a key role in industrial bioleaching; it has the capacity of generating and maintaining acidic conditions by producing sulfuric acid and it can also remove sulfur layers from the surface of minerals, which are detrimental for their dissolution. CLST is a strain of 10.1601/nm.2199 able to tolerate moderate chloride concentrations (up to 15 g L-1 Cl-), a feature that is quite unusual in extreme acidophilic microorganisms. Basic microbiological features and genomic properties of this biotechnologically relevant strain are described in this work. The 3,974,949 bp draft genome is arranged into 40 scaffolds of 389 contigs containing 3866 protein-coding genes and 75 RNAs encoding genes. This is the first draft genome of a halotolerant 10.1601/nm.2199 strain. The release of the genome sequence of this strain improves representation of these extreme acidophilic Gram negative bacteria in public databases and strengthens the framework for further investigation of the physiological diversity and ecological function of 10.1601/nm.2199 populations.

5.
Stand Genomic Sci ; 12: 77, 2017.
Article in English | MEDLINE | ID: mdl-29255572

ABSTRACT

Acidithiobacillus albertensis is an extremely acidophilic, mesophilic, obligatory autotrophic sulfur-oxidizer, with potential importance in the bioleaching of sulfidic metal ores, first described in the 1980s. Here we present the draft genome sequence of Acidithiobacillus albertensis DSM 14366T, thereby both filling a long-standing gap in the genomics of the acidithiobacilli, and providing further insight into the understanding of the biology of the non iron-oxidizing members of the Acidithiobacillus genus. The assembled genome is 3,1 Mb, and contains 47 tRNAs, tmRNA gene and 2 rRNA operons, along with 3149 protein-coding predicted genes. The Whole Genome Shotgun project was deposited in DDBJ/EMBL/GenBank under the accession MOAD00000000.

6.
Front Microbiol ; 8: 30, 2017.
Article in English | MEDLINE | ID: mdl-28154559

ABSTRACT

The acidithiobacilli are sulfur-oxidizing acidophilic bacteria that thrive in both natural and anthropogenic low pH environments. They contribute to processes that lead to the generation of acid rock drainage in several different geoclimatic contexts, and their properties have long been harnessed for the biotechnological processing of minerals. Presently, the genus is composed of seven validated species, described between 1922 and 2015: Acidithiobacillus thiooxidans, A. ferrooxidans, A. albertensis, A. caldus, A. ferrivorans, A. ferridurans, and A. ferriphilus. However, a large number of Acidithiobacillus strains and sequence clones have been obtained from a variety of ecological niches over the years, and many isolates are thought to vary in phenotypic properties and cognate genetic traits. Moreover, many isolates remain unclassified and several conflicting specific assignments muddle the picture from an evolutionary standpoint. Here we revise the phylogenetic relationships within this species complex and determine the phylogenetic species boundaries using three different typing approaches with varying degrees of resolution: 16S rRNA gene-based ribotyping, oligotyping, and multi-locus sequencing analysis (MLSA). To this end, the 580 16S rRNA gene sequences affiliated to the Acidithiobacillus spp. were collected from public and private databases and subjected to a comprehensive phylogenetic analysis. Oligotyping was used to profile high-entropy nucleotide positions and resolve meaningful differences between closely related strains at the 16S rRNA gene level. Due to its greater discriminatory power, MLSA was used as a proxy for genome-wide divergence in a smaller but representative set of strains. Results obtained indicate that there is still considerable unexplored diversity within this genus. At least six new lineages or phylotypes, supported by the different methods used herein, are evident within the Acidithiobacillus species complex. Although the diagnostic characteristics of these subgroups of strains are as yet unresolved, correlations to specific metadata hint to the mechanisms behind econiche-driven divergence of some of the species/phylotypes identified. The emerging phylogenetic structure for the genus outlined in this study can be used to guide isolate selection for future population genomics and evolutionary studies in this important acidophile model.

7.
Res Microbiol ; 167(7): 555-67, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27288569

ABSTRACT

The genus Acidithiobacillus comprises several species of Gram-negative acidophilic bacteria that thrive in natural and man-made low pH environments in a variety of geo-climatic contexts. Beyond their fundamental interest as model extreme acidophiles, these bacteria are involved in the processing of minerals and the desulfurization of coal and natural gas, and are also sources of environmental pollution due to their generation of acid mine drainage and corrosion of cement and concrete structures. Acidithiobacillus spp. are therefore considered a biotechnologically relevant group of bacteria, and their identification and screening in natural and industrial environments is of great concern. Several molecular typing methodologies have been instrumental in improving knowledge of the inherent diversity of acidithiobacilli by providing information on the genetic subtypes sampled in public and private culture collections; more recently, they have provided specific insight into the diversity of acidithiobacilli present in industrial and natural environments. The aim of this review is to provide an overview of techniques used in molecular detection, identification and typing of Acidithiobacillus spp. These methods will be discussed in the context of their contribution to the general and specific understanding of the role of the acidithiobacilli in microbial ecology and industrial biotechnology. Emerging opportunities for industrial and environmental surveillance of acidithiobacilli using next-generation molecular typing methodologies are also reviewed.


Subject(s)
Acidithiobacillus/classification , Acidithiobacillus/isolation & purification , Environmental Microbiology , Genetic Variation , Industrial Microbiology , Molecular Typing , Acidithiobacillus/metabolism , Minerals/metabolism , Mining/methods
8.
Res Microbiol ; 165(9): 735-42, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25176612

ABSTRACT

Phenotypic, metabolic and genetic properties of several Acidithiobacillus caldus strains indicate the existence of as yet undefined levels of variation within the species. Inspite of this, intraspecies genetic diversity has not yet been explored in detail. In this study, the design and implementation of a Multi Locus Sequence Typing (MLST) scheme for At. caldus is described. This represents the first MLST-based study applied to industrial isolates of the species. Seven informative and discriminant MLST markers were selected using a sequence-driven approach and a custom-designed bioinformatic pipeline. The allelic profiles of thirteen At. caldus strains from diverse geographical origins and industrial settings were derived using this scheme. MLST-based population structure analysis indicated only moderate amounts of genetic diversity within the set of strains, further supporting their current assignment to a single species. Also, no clear evidence for geographical isolation could be derived from this study. However, the prevalence of sequence type 1 in heap leaching industrial settings support the view that bioprocess conditions and dynamics may have a strong influence on At. caldus (microbial) microdiversity patterns. The MLST scheme presented herein is a valuable tool for the identification and classification of strains of At. caldus for either ecological or evolutionary studies and possibly also for industrial monitoring purposes.


Subject(s)
Acidithiobacillus/classification , Acidithiobacillus/genetics , Genetic Variation , Multilocus Sequence Typing/methods , Environmental Microbiology , Geography , Industrial Microbiology
9.
PLoS One ; 8(11): e78237, 2013.
Article in English | MEDLINE | ID: mdl-24250794

ABSTRACT

BACKGROUND: Acidithiobacillus caldus is a sulfur oxidizing extreme acidophile and the only known mesothermophile within the Acidithiobacillales. As such, it is one of the preferred microbes for mineral bioprocessing at moderately high temperatures. In this study, we explore the genomic diversity of A. caldus strains using a combination of bioinformatic and experimental techniques, thus contributing first insights into the elucidation of the species pangenome. PRINCIPAL FINDINGS: Comparative sequence analysis of A. caldus ATCC 51756 and SM-1 indicate that, despite sharing a conserved and highly syntenic genomic core, both strains have unique gene complements encompassing nearly 20% of their respective genomes. The differential gene complement of each strain is distributed between the chromosomal compartment, one megaplasmid and a variable number of smaller plasmids, and is directly associated to a diverse pool of mobile genetic elements (MGE). These include integrative conjugative and mobilizable elements, genomic islands and insertion sequences. Some of the accessory functions associated to these MGEs have been linked previously to the flexible gene pool in microorganisms inhabiting completely different econiches. Yet, others had not been unambiguously mapped to the flexible gene pool prior to this report and clearly reflect strain-specific adaption to local environmental conditions. SIGNIFICANCE: For many years, and because of DNA instability at low pH and recurrent failure to genetically transform acidophilic bacteria, gene transfer in acidic environments was considered negligible. Findings presented herein imply that a more or less conserved pool of actively excising MGEs occurs in the A. caldus population and point to a greater frequency of gene exchange in this econiche than previously recognized. Also, the data suggest that these elements endow the species with capacities to withstand the diverse abiotic and biotic stresses of natural environments, in particular those associated with its extreme econiche.


Subject(s)
Acidithiobacillus/genetics , DNA Transposable Elements/genetics , Genome, Bacterial , Sulfur/metabolism , Acidithiobacillus/metabolism , Bacterial Proteins/genetics , Computational Biology , Conjugation, Genetic , Plasmids/genetics
10.
Rev Med Chil ; 137(2): 208-14, 2009 Feb.
Article in Spanish | MEDLINE | ID: mdl-19543642

ABSTRACT

BACKGROUND: Most clinical isolates of Vibrio parahaemolyticus produce a major virulence factor known as the thermostable direct hemolysin (TDH). TDH is encoded by the tdh gene which is located in a genomic pathogenicity island (PAI). Most environmental isolates are described as tdh negative. AIM: To assess if environmental strains lack the full pathogenicity island or if only the tdh gene is deleted. MATERIAL AND METHODS: Thirty eight clinical and 66 environmental strains of Vibrio parahaemolyticus were studied. PAI was characterized by polymerase chain reaction (PCR). The presence of tdhA and tdhS genes, was determined by Southern blot. RESULTS: Fifty three environmental strains (80%) lacked a full PAI when compared with clinical strains. In environmental strains, Southern blot and sequence analysis showed that a genetic region of 80 kilobase pairs including genes from VPA1310 to VPA1396 was missing. CONCLUSIONS: These results highlight the genetic dynamism of Vibrio parahaemolyticus pathogenecity island region and suggest that new pathogenic strains could appear by horizontal transfer of the island between toxigenic and non-toxigenic strains.


Subject(s)
Genomic Islands/genetics , Hemolysin Proteins/genetics , Vibrio parahaemolyticus/genetics , Bacterial Toxins/genetics , Base Sequence , Chile , DNA, Bacterial/isolation & purification , Environmental Microbiology , Humans , Molecular Sequence Data , Polymerase Chain Reaction , Shellfish/microbiology , Vibrio parahaemolyticus/isolation & purification , Vibrio parahaemolyticus/pathogenicity , Virulence Factors
11.
Rev. méd. Chile ; 137(2): 208-214, feb. 2009. ilus, tab
Article in Spanish | LILACS | ID: lil-516085

ABSTRACT

Background: Most clinical isolates of Vibrio parahaemolyticus produce a major virulence factor known as the thermostable direct hemolysin (TDH). TDH is encoded by the tdh gene which is located in a genomic pathogenicity island (PAI). Most environmental isolates are described as tdh negative. Aim: To assess if environmental strains lack the full pathogenicity island or if only the tdh gene is deleted. Material and methods: Thirty eight clinical and 66 environmental strains of Vibrio parahaemolyticus were studied. PAI was characterized by polymerase chain reaction (PCR). The presence of tdhA and tdhS genes, was determined by Southern blot. Results: Fifty three environmental strains (80%) lacked a full PAI when compared with clinical strains. In environmental strains, Southern blot and sequence analysis showed that a genetic región of 80 kilobase pairs including genes from VPA1310 to VPA1396 was missing. Conclusions: These results highlight the genetic dynamism of Vibrio parahaemolyticus pathogenecity island región and suggest that new pathogenic strains could appear by horizontal transfer of the island between toxigenic and non-toxigenic strains.


Subject(s)
Humans , Genomic Islands/genetics , Hemolysin Proteins/genetics , Vibrio parahaemolyticus/genetics , Bacterial Toxins/genetics , Base Sequence , Chile , DNA, Bacterial/isolation & purification , Environmental Microbiology , Molecular Sequence Data , Polymerase Chain Reaction , Shellfish/microbiology , Vibrio parahaemolyticus/isolation & purification , Vibrio parahaemolyticus/pathogenicity , Virulence Factors
12.
Rev Med Chil ; 135(2): 264-9, 2007 Feb.
Article in Spanish | MEDLINE | ID: mdl-17406746

ABSTRACT

The San Vicente de Paul Hospital was the first Clinical Hospital of the University of Chile and was located at the same place of present School of Medicine. The School area contains several old buildings, which are probably remains of the San Vicente de Paul Hospital. After a careful study of the current plans of the Faculty of Medicine of the University of Chile and those of the San Vicente de Paul Hospital, and after checking measurements on the actual site, we were able to demonstrate that two and a half clinical rooms of the original building and some parts of the old laundry still remain intact. At present, these constructions are being used as storerooms, student's union offices, and other activities. We expect that this article may contribute to improve the knowledge of our roots by our own as well as by future generations and that it may inspire our authorities to take care and preserve this important patrimonial remains of our national medicine.


Subject(s)
Archaeology , Hospitals/history , Architecture/history , Chile , History, 19th Century , History, 20th Century , History, 21st Century , Humans , Schools, Medical/history
13.
Proc Natl Acad Sci U S A ; 104(9): 3135-40, 2007 Feb 27.
Article in English | MEDLINE | ID: mdl-17360620

ABSTRACT

Glutamyl-tRNA (Glu-tRNA), formed by Glu-tRNA synthetase (GluRS), is a substrate for protein biosynthesis and tetrapyrrole formation by the C(5) pathway. In this route Glu-tRNA is transformed to delta-aminolevulinic acid, the universal precursor of tetrapyrroles (e.g., heme and chlorophyll) by the action of Glu-tRNA reductase (GluTR) and glutamate semialdehyde aminotransferase. GluTR is a target of feedback regulation by heme. In Acidithiobacillus ferrooxidans, an acidophilic bacterium that expresses two GluRSs (GluRS1 and GluRS2) with different tRNA specificity, the intracellular heme level varies depending on growth conditions. Under high heme requirement for respiration increased levels of GluRS and GluTR are observed. Strikingly, when intracellular heme is in excess, the cells respond by a dramatic decrease of GluRS activity and the level of GluTR. The recombinant GluRS1 enzyme is inhibited in vitro by hemin, but NADPH restores its activity. These results suggest that GluRS plays a major role in regulating the cellular level of heme.


Subject(s)
Acidithiobacillus/genetics , Aldehyde Oxidoreductases/metabolism , Feedback, Physiological/physiology , Gene Expression Regulation, Bacterial/physiology , Glutamate-tRNA Ligase/metabolism , Heme/metabolism , Acidithiobacillus/enzymology , Blotting, Western , DNA Primers , Hemin/metabolism , NADP/metabolism , Recombinant Proteins/metabolism , Spectrophotometry
14.
Rev. méd. Chile ; 135(2): 264-269, feb. 2007. ilus
Article in Spanish | LILACS, MINSALCHILE | ID: biblio-1539429

ABSTRACT

The San Vicente de Paul Hospital was the first Clinical Hospital of the University of Chile and was located at the same place of present School of Medicine. The School are contains several old buildings, which are probably remains of the San Vicente de Paul Hospital. After a careful study of the current plans of the Faculty of Medicine of the University of Chile and those of the San Vicente de Paul Hospital, and after checking measurements on the actual site, we were able to demonstrate that two and a half clinical rooms of the original building and some parts of the old laundry still remain intact. At present, these constructions are being used as storerooms, student's union offices, and other activities. We expect that this article may contribute to improve the knowledge of our roots by our own as well as by future generations and that it may inspire our authorities to take care and preserve this important patrimonial remains of our national medicine


Subject(s)
Hospitals, Public/history , Chile
15.
Rev. méd. Chile ; 135(2): 264-269, feb. 2007. ilus
Article in Spanish | HISA - History of Health | ID: his-18910

ABSTRACT

The San Vicente de Paul Hospital was the first Clinical Hospital of the University of Chile and was located at the same place of present School of Medicine. The School are contains several old buildings, which are probably remains of the San Vicente de Paul Hospital. After a careful study of the current plans of the Faculty of Medicine of the University of Chile and those of the San Vicente de Paul Hospital, and after checking measurements on the actual site, we were able to demonstrate that two and a half clinical rooms of the original building and some parts of the old laundry still remain intact. At present, these constructions are being used as storerooms, student's union offices, and other activities. We expect that this article may contribute to improve the knowledge of our roots by our own as well as by future generations and that it may inspire our authorities to take care and preserve this important patrimonial remains of our national medicine (AU)


Subject(s)
Hospitals, Public/history , Public Health/history , Chile
16.
FEBS Lett ; 557(1-3): 133-5, 2004 Jan 16.
Article in English | MEDLINE | ID: mdl-14741355

ABSTRACT

Two types of glutamyl-tRNA synthetase exist: the discriminating enzyme (D-GluRS) forms only Glu-tRNA(Glu), while the non-discriminating one (ND-GluRS) also synthesizes Glu-tRNA(Gln), a required intermediate in protein synthesis in many organisms (but not in Escherichia coli). Testing the capacity to complement a thermosensitive E. coli gltX mutant and to suppress an E. coli trpA49 missense mutant we examined the properties of heterologous gltX genes. We demonstrate that while Acidithiobacillus ferrooxidans GluRS1 and Bacillus subtilis Q373R GluRS form Glu-tRNA(Glu), A. ferrooxidans and Helicobacter pylori GluRS2 form Glu-tRNA(Gln) in E. coli in vivo.


Subject(s)
Escherichia coli/enzymology , Glutamate-tRNA Ligase/metabolism , RNA, Transfer, Amino Acyl/metabolism , Base Sequence , DNA Primers , Escherichia coli/genetics , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Glutamate-tRNA Ligase/genetics , Mutation, Missense , Polymerase Chain Reaction , Substrate Specificity
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