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Journal of Oral Microbiology 2017species are non-motile facultative anaerobic/anaerobic bacteria that are found mostly in the oral cavity and some other parts of the human body, in animals, and even in... (Review)
Review
species are non-motile facultative anaerobic/anaerobic bacteria that are found mostly in the oral cavity and some other parts of the human body, in animals, and even in ocean sediments. Valid species include , , , , , , and . Some species require serum or blood for growth. All species ferment carbohydrates and produce lactic acid that may be involved with tooth decay. Acting as opportunistic pathogens, they are involved in a variety of diseases, and have been isolated from immunocompromised but also immunocompetent individuals. Mucositis, oral lesions, wounds, and abscesses may predispose to septicemia. Because identification of species by phenotypic features occasionally lead to misidentification, genetic techniques such as 16S rRNA gene sequencing is recommended. Early diagnosis and treatment of leptotrichia infections is important for positive outcomes. Over the last years, species have been associated with several changes in taxonomy and new associations with clinical diseases. Such changes are reported in this updated review.
PubMed: 29081911
DOI: 10.1080/20002297.2017.1368848 -
Journal of Clinical Microbiology Feb 2023species are anaerobic, Gram-negative bacilli increasingly recognized as pathogens capable of causing invasive infections such as bloodstream infection (BSI),... (Review)
Review
species are anaerobic, Gram-negative bacilli increasingly recognized as pathogens capable of causing invasive infections such as bloodstream infection (BSI), particularly among immunocompromised patients. However, there is a paucity of data regarding epidemiology, antimicrobial susceptibility, optimal treatment, and clinical outcomes among patients with bacteremia. Patient risk factors, treatment approaches, and outcomes of a retrospective cohort of adult patients with BSI at a tertiary medical center (Mayo Clinic Rochester [MCR]) were evaluated. Concurrently, species, temporal trends, and antimicrobial susceptibility testing (AST) results of isolates submitted to a reference laboratory (Mayo Clinic Laboratories) over the past 10 years were examined. We identified 224 blood culture isolates of species, with 26 isolates from patients treated at MCR. The most frequent species included L. trevisanii (49%), L. buccalis (24%), and L. wadei (16%). species demonstrated >90% susceptibility to penicillin, metronidazole, ertapenem, and piperacillin-tazobactam. However, 96% (74/77) of isolates were resistant to moxifloxacin. For patients treated at MCR, the mean patient age was 55 years (standard deviation [SD], 17), with 9 females (35%), and all were neutropenic at the time of BSI. The primary sources of infection were gastrointestinal (58%), intravascular catheter (35%), and odontogenic (15%). Patients were treated with metronidazole (42%), piperacillin-tazobactam (27%), or carbapenems (19%). The mean duration of treatment was 11 days (SD, 4.5), with a 60-day all-cause mortality of 19% and no microbiologic relapse. species are rare but important causes of BSI in neutropenic patients. Due to evolving antimicrobial susceptibility profiles, a review of AST results is necessary when selecting optimal antimicrobial therapy.
Topics: Adult; Female; Humans; Middle Aged; Metronidazole; Leptotrichia; Retrospective Studies; Bacteremia; Anti-Infective Agents; Piperacillin, Tazobactam Drug Combination; Gram-Negative Bacteria; Sepsis; Anti-Bacterial Agents; Microbial Sensitivity Tests
PubMed: 36715514
DOI: 10.1128/jcm.01733-22 -
Annals of Clinical and Laboratory... 2016Leptotrichia is a pencil-shaped Gram-negative rod and is known as an uncommon pathogen of bacteremia in immunocompromised patients. However, because culture and... (Review)
Review
Leptotrichia is a pencil-shaped Gram-negative rod and is known as an uncommon pathogen of bacteremia in immunocompromised patients. However, because culture and identification of Leptotrichia species is difficult in clinical laboratories, Leptotrichia goodfellowii is grossly underestimated as a human pathogen. In this study, we report a case of L. goodfellowii bacteremia in an immunocompetent patient and review 5 previously reported cases describing infection with L. goodfellowii.
Topics: Aged; Ceftriaxone; Fusobacteriaceae Infections; Humans; Leptotrichia; Male
PubMed: 26927348
DOI: No ID Found -
Nature Oct 2017RNA has important and diverse roles in biology, but molecular tools to manipulate and measure it are limited. For example, RNA interference can efficiently knockdown...
RNA has important and diverse roles in biology, but molecular tools to manipulate and measure it are limited. For example, RNA interference can efficiently knockdown RNAs, but it is prone to off-target effects, and visualizing RNAs typically relies on the introduction of exogenous tags. Here we demonstrate that the class 2 type VI RNA-guided RNA-targeting CRISPR-Cas effector Cas13a (previously known as C2c2) can be engineered for mammalian cell RNA knockdown and binding. After initial screening of 15 orthologues, we identified Cas13a from Leptotrichia wadei (LwaCas13a) as the most effective in an interference assay in Escherichia coli. LwaCas13a can be heterologously expressed in mammalian and plant cells for targeted knockdown of either reporter or endogenous transcripts with comparable levels of knockdown as RNA interference and improved specificity. Catalytically inactive LwaCas13a maintains targeted RNA binding activity, which we leveraged for programmable tracking of transcripts in live cells. Our results establish CRISPR-Cas13a as a flexible platform for studying RNA in mammalian cells and therapeutic development.
Topics: Biocatalysis; CRISPR-Associated Proteins; CRISPR-Cas Systems; Cell Line, Tumor; Cell Survival; Escherichia coli; Gene Editing; Gene Knockdown Techniques; Genes, Reporter; HEK293 Cells; Humans; Leptotrichia; Plant Cells; RNA; RNA Interference; Stress, Physiological; Substrate Specificity
PubMed: 28976959
DOI: 10.1038/nature24049 -
Medecine Et Maladies Infectieuses Apr 2012
Review
Topics: Aborted Fetus; Abortion, Spontaneous; Amniotic Fluid; Bacterial Typing Techniques; Chromatography, Gas; Diagnosis, Differential; Female; Fusobacteriaceae Infections; Fusobacterium Infections; Humans; Lactic Acid; Leptotrichia; Male; Pregnancy; Ribotyping; Stillbirth
PubMed: 22465058
DOI: 10.1016/j.medmal.2012.02.005 -
Anaerobe Jun 2008Leptotrichia species typically colonize the oral cavity and genitourinary tract. These anaerobic bacteria belong to the normal flora of humans and are seldom found in... (Review)
Review
Leptotrichia species typically colonize the oral cavity and genitourinary tract. These anaerobic bacteria belong to the normal flora of humans and are seldom found in clinically significant specimens. However, on rare occasions, Leptotrichia has been isolated from blood cultures of patients with lesions in the oral mucosa, in particular from patients with neutropenia. These organisms should be considered potential pathogens in neutropenic patients, especially when breaks in the mucosal barriers are present through which they frequently spread to the bloodstream. Leptotrichia has also been recovered from immunocompetent persons, e.g. patients with endocarditis. Although their role in infections remains elusive and not much is known, they have been suggested as emerging pathogens. The present review deals with taxonomy, diagnosis, clinical importance, pathogenesis, host defence, infection control, and spectrum of Leptotrichia infections, and ends with a few typical case reports. Currently, six species have been validly published, but a number of yet uncultivable species exist. Molecular methods recovering uncultivable species should be used to get a real idea of their role as pathogens.
Topics: Adolescent; Adult; Aged; Bacteremia; Blood; Child; Child, Preschool; Female; Fusobacteriaceae Infections; Humans; Leptotrichia; Male; Middle Aged; Mouth; Phylogeny; RNA, Ribosomal, 16S
PubMed: 18539056
DOI: 10.1016/j.anaerobe.2008.04.004 -
Nature Protocols Oct 2019Rapid detection of nucleic acids is integral to applications in clinical diagnostics and biotechnology. We have recently established a CRISPR-based diagnostic platform...
Rapid detection of nucleic acids is integral to applications in clinical diagnostics and biotechnology. We have recently established a CRISPR-based diagnostic platform that combines nucleic acid pre-amplification with CRISPR-Cas enzymology for specific recognition of desired DNA or RNA sequences. This platform, termed specific high-sensitivity enzymatic reporter unlocking (SHERLOCK), allows multiplexed, portable, and ultra-sensitive detection of RNA or DNA from clinically relevant samples. Here, we provide step-by-step instructions for setting up SHERLOCK assays with recombinase-mediated polymerase pre-amplification of DNA or RNA and subsequent Cas13- or Cas12-mediated detection via fluorescence and colorimetric readouts that provide results in <1 h with a setup time of less than 15 min. We also include guidelines for designing efficient CRISPR RNA (crRNA) and isothermal amplification primers, as well as discuss important considerations for multiplex and quantitative SHERLOCK detection assays.
Topics: CRISPR-Cas Systems; DNA Primers; Endonucleases; Humans; Leptotrichia; Nucleic Acid Amplification Techniques; Nucleic Acids; Protein Engineering; RNA, Guide, CRISPR-Cas Systems; Recombinant Proteins; Ribonucleases; Workflow; Zika Virus; Zika Virus Infection
PubMed: 31548639
DOI: 10.1038/s41596-019-0210-2 -
American Journal of Therapeutics 2019
Topics: Bacteremia; Fusobacteriaceae Infections; Hematologic Neoplasms; Humans; Leptotrichia
PubMed: 31710317
DOI: 10.1097/MJT.0000000000000891 -
Clinical Microbiology Reviews Apr 2016Bacterial vaginosis (BV) is the most commonly reported microbiological syndrome among women of childbearing age. BV is characterized by a shift in the vaginal flora from... (Review)
Review
Bacterial vaginosis (BV) is the most commonly reported microbiological syndrome among women of childbearing age. BV is characterized by a shift in the vaginal flora from the dominant Lactobacillus to a polymicrobial flora. BV has been associated with a wide array of health issues, including preterm births, pelvic inflammatory disease, increased susceptibility to HIV infection, and other chronic health problems. A number of potential microbial pathogens, singly and in combinations, have been implicated in the disease process. The list of possible agents continues to expand and includes members of a number of genera, including Gardnerella, Atopobium, Prevotella, Peptostreptococcus, Mobiluncus, Sneathia, Leptotrichia, Mycoplasma, and BV-associated bacterium 1 (BVAB1) to BVAB3. Efforts to characterize BV using epidemiological, microscopic, microbiological culture, and sequenced-based methods have all failed to reveal an etiology that can be consistently documented in all women with BV. A careful analysis of the available data suggests that what we term BV is, in fact, a set of common clinical signs and symptoms that can be provoked by a plethora of bacterial species with proinflammatory characteristics, coupled to an immune response driven by variability in host immune function.
Topics: Bacteria; DNA, Bacterial; Female; Humans; Microbiota; Vaginosis, Bacterial
PubMed: 26864580
DOI: 10.1128/CMR.00075-15 -
Science (New York, N.Y.) Aug 2016The clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated genes (Cas) adaptive immune system defends microbes against foreign genetic...
The clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated genes (Cas) adaptive immune system defends microbes against foreign genetic elements via DNA or RNA-DNA interference. We characterize the class 2 type VI CRISPR-Cas effector C2c2 and demonstrate its RNA-guided ribonuclease function. C2c2 from the bacterium Leptotrichia shahii provides interference against RNA phage. In vitro biochemical analysis shows that C2c2 is guided by a single CRISPR RNA and can be programmed to cleave single-stranded RNA targets carrying complementary protospacers. In bacteria, C2c2 can be programmed to knock down specific mRNAs. Cleavage is mediated by catalytic residues in the two conserved Higher Eukaryotes and Prokaryotes Nucleotide-binding (HEPN) domains, mutations of which generate catalytically inactive RNA-binding proteins. These results broaden our understanding of CRISPR-Cas systems and suggest that C2c2 can be used to develop new RNA-targeting tools.
Topics: Adaptive Immunity; Bacterial Proteins; Base Sequence; CRISPR-Cas Systems; Clustered Regularly Interspaced Short Palindromic Repeats; Endoribonucleases; Escherichia coli; Gene Knockdown Techniques; Genetic Loci; Leptotrichia; Levivirus; Molecular Sequence Data; Protein Structure, Tertiary; RNA Cleavage; RNA, Guide, CRISPR-Cas Systems
PubMed: 27256883
DOI: 10.1126/science.aaf5573