An expanded genetic toolkit for inducible expression and targeted gene silencing inRickettsia parkeri DOI Creative Commons
Jon McGinn,

A. Wen,

Desmond L. Edwards

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: March 15, 2024

ABSTRACT Pathogenic species within the Rickettsia genus are transmitted to humans through arthropod vectors and cause a spectrum of diseases ranging from mild life-threatening. Despite rickettsiae posing an emerging global health risk, genetic requirements their infectious life cycles remain poorly understood. A major hurdle toward building this understanding has been lack efficient tools for manipulation, owing technical difficulties associated with obligate intracellular nature. To end, we implemented Tet-On system enable conditional gene expression in parkeri . Using Tet-On, show inducible antibiotic resistance fluorescent reporter. We further used promoter screen ability R. express four variants catalytically dead Cas9 (dCas9). demonstrate that all dCas9 can be expressed CRISPR interference (CRISPRi)-mediated targeted knockdown. knockdown as well endogenous virulence factor sca2 Altogether, have developed systems CRISPRi-mediated first time rickettsiae, laying groundwork more scalable, mechanistic investigations into cycles. IMPORTANCE The spotted fever group contains vector-borne pathogenic bacteria neglected threats public health. Due nature development manipulation stunted, molecular underpinnings lifecycle Here, expand toolkit by introducing These allow relatively easy rickettsial expression. effectiveness these disrupting cycle using CRISPRi deplete factor. will crucial comprehensive detailed biology pathogenesis.

Language: Английский

A cross-sectional study on the nasopharyngeal microbiota of individuals with SARS-CoV-2 infection across three COVID-19 waves in India DOI Creative Commons
Tungadri Bose,

Wasimuddin,

Varnali Acharya

et al.

Frontiers in Microbiology, Journal Year: 2023, Volume and Issue: 14

Published: Sept. 6, 2023

Background Multiple variants of the SARS-CoV-2 virus have plagued world through successive waves infection over past three years. Independent research groups across geographies shown that microbiome composition in COVID-19 positive patients (CP) differs from negative individuals (CN). However, these observations were based on limited-sized sample-sets collected primarily early days pandemic. Here, we study nasopharyngeal microbiota patients, wherein samples been witnessed India, which driven by different concern. Methods The swabs 589 subjects providing for diagnostics purposes at Centre Cellular and Molecular Biology (CSIR-CCMB), Hyderabad, India subjected to 16s rRNA gene amplicon - sequencing. Findings We found variations symptomatic vs. asymptomatic patients. CP showed a marked shift microbial diversity compared CN, wave-dependent manner. Rickettsiaceae was only family noted be consistently depleted waves. genera Staphylococcus , Anhydrobacter Thermus Aerococcus observed highly abundant when group. In general, decrease burden opportunistic pathogens host during later infection. Interpretation To our knowledge, this is first analytical cross-sectional scale, designed understand relation between evolving nature changes human microbiota. Although no clear signatures observed, shall pave way better understanding disease pathophysiology help gather preliminary evidence whether interventions can protection or faster recovery.

Language: Английский

Citations

7
Chromosome structure and DNA replication dynamics during the life cycle of the predatory bacterium Bdellovibrio bacteriovorus DOI Creative Commons
Karolina Pląskowska, Jolanta Zakrzewska‐Czerwińska

FEMS Microbiology Reviews, Journal Year: 2023, Volume and Issue: 47(6)

Published: Oct. 3, 2023

Bdellovibrio bacteriovorus, an obligate predatory Gram-negative bacterium that proliferates inside and kills other bacteria, was discovered more than 60 years ago. However, we have only recently begun to understand the detailed cell biology of this proficient bacterial killer. bacteriovorus exhibits a peculiar life cycle bimodal proliferation, thus represents attractive model for studying novel aspects biology. The B. consists two phases: free-living nonreplicative attack phase intracellular reproductive phase. During phase, grows as elongated undergoes binary or nonbinary fission, depending on prey size. In review, discuss: (1) how chromosome structure is remodeled during its cycle; (2) replication dynamics depends proliferation mode; (3) initiation controlled cycle, (4) spatiotemporally coordinated with program.

Language: Английский

Citations

7
An expanded genetic toolkit for inducible expression and targeted gene silencing in Rickettsia parkeri DOI
Jon McGinn,

A. Wen,

Desmond L. Edwards

et al.

Journal of Bacteriology, Journal Year: 2024, Volume and Issue: 206(7)

Published: June 6, 2024

Pathogenic species within the

Language: Английский

Citations

2
Quantitative analysis of morphogenesis and growth dynamics in an obligate intracellular bacterium DOI

Wanda M. Figueroa-Cuilan,

Oihane Irazoki,

Marissa Feeley

et al.

Molecular Biology of the Cell, Journal Year: 2023, Volume and Issue: 34(7)

Published: April 5, 2023

Obligate intracellular bacteria of the order Rickettsiales include important human pathogens. However, our understanding biology Rickettsia species is limited by challenges imposed their obligate lifestyle. To overcome this roadblock, we developed methods to assess cell wall composition, growth, and morphology parkeri, a pathogen in spotted fever group genus. Analysis R. parkeri revealed unique features that distinguish it from free-living alphaproteobacteria. Using novel fluorescence microscopy approach, quantified live host cells found fraction population undergoing division decreased over course infection. We further demonstrated feasibility localizing fusions, for example, protein ZapA, first time. evaluate growth kinetics, an imaging-based assay improves on throughput resolution other methods. Finally, applied these tools quantitatively demonstrate actin homologue MreB required rod shape. Collectively, toolkit was high-throughput, quantitative understand morphogenesis translatable bacteria.

Language: Английский

Citations

5
Rickettsia parkeri DOI Creative Commons
Allison T. Scott, Cassandra Vondrak, Allen G. Sanderlin

et al.

Trends in Microbiology, Journal Year: 2022, Volume and Issue: 30(5), P. 511 - 512

Published: Feb. 1, 2022

Language: Английский

Citations

8
Subversion of host cell signaling: The arsenal of Rickettsial species DOI Creative Commons
Dan Huang, Jingjing Luo, Xuan Ouyang

et al.

Frontiers in Cellular and Infection Microbiology, Journal Year: 2022, Volume and Issue: 12

Published: Oct. 31, 2022

Rickettsia is a genus of nonmotile, Gram-negative, non-spore-forming, highly pleomorphic bacteria that cause severe epidemic rickettsioses. The spotted fever group and typhi are major members the Rickettsia. Rickettsial species from two groups subvert diverse host cellular processes, including membrane dynamics, actin cytoskeleton phosphoinositide metabolism, intracellular trafficking, immune defense, to promote their colonization intercellular transmission through secreted effectors (virulence factors). However, lineage-specific rickettsiae have exploited divergent strategies accomplish such challenging tasks these elaborated focus on distinct cell processes. In present review, we summarized current understandings how different rickettsial employ effectors’ arsenal affect processes in order own replication or avoid destruction.

Language: Английский

Citations

8
Thriving in Oxygen While Preventing ROS Overproduction: No Two Systems Are Created Equal DOI Creative Commons
Ofelia Méndez-Romero, Carolina Ricardez-García,

Paulina Castañeda-Támez

et al.

Frontiers in Physiology, Journal Year: 2022, Volume and Issue: 13

Published: April 4, 2022

From 2.5 to 2.0 billion years ago, atmospheric oxygen concentration [O2] rose thousands of times, leading the first mass extinction. Reactive Oxygen Species (ROS) produced by non-catalyzed partial reduction O2 were highly toxic eliminating many species. Survivors developed different strategies cope with ROS toxicity. At same time, using as final acceptor in respiratory chains increased ATP production manifold. Thus, both and strong drivers evolution, species optimized aerobic metabolism while developing ROS-neutralizing mechanisms. The line defense is preventing overproduction two mechanisms parallel: 1) Physiological uncoupling systems (PUS), which increase rate electron fluxes systems. 2) Avoidance excess [O2]. However, it seems that avoidance efficiency improved, PUSs became less efficient. PUS includes branched proton sinks, may be specific, mitochondrial proteins (UCPs) or unspecific, permeability transition pore (PTP). High also involved strategies: Cell association, biofilms multi-cellularity allowed gas-permeable organisms (oxyconformers) from bacterial arthropods exclude O2. Motility, migrate hypoxic niches. 3) Oxyregulator organisms: early fish, O2-impermeable epithelium excluded all gases only exact amounts entered through specialized Here we follow parallel evolution O2-avoidance, critical lost efficiency. In regard, there fewer evidence on their although UCPs have indeed drifted function some not clear whether PTPs exist.

Language: Английский

Citations

7
Typhus group Rickettsia community-acquired bacterial central nervous system infections: We must think outside the box! DOI Creative Commons

Pauline B Roxas,

Jiménez Cruz,

Nicole Rae Horelka

et al.

Journal of the Neurological Sciences, Journal Year: 2024, Volume and Issue: 466, P. 123281 - 123281

Published: Oct. 19, 2024

Language: Английский

Citations

1
A conserved interaction between the effector Sca4 and host clathrin suggests additional contributions for Sca4 during rickettsial infection DOI
Cassandra Vondrak, Brandon Sit,

Chanakan Suwanbongkot

et al.

Infection and Immunity, Journal Year: 2024, Volume and Issue: 92(12)

Published: Nov. 13, 2024

Intracellular bacterial pathogens deploy secreted effector proteins that manipulate diverse host machinery and pathways to promote infection. Although many effectors carry out a single function or interaction, there are growing number of capable interacting with multiple factors. However, few by arthropod-borne obligate intracellular

Language: Английский

Citations

1
Cell-selective proteomics reveal novel effectors secreted by an obligate intracellular bacterial pathogen DOI Creative Commons
Allen G. Sanderlin, Hannah K. Margolis,

Abigail F. Meyer

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Nov. 17, 2023

Abstract Pathogenic bacteria secrete protein effectors to hijack host machinery and remodel their infectious niche. Rickettsia spp. are obligate intracellular that can cause life- threatening disease, but absolute dependence on the cell environment has impeded discovery of rickettsial targets. We implemented bioorthogonal non-canonical amino acid tagging (BONCAT) during R. parkeri infection selectively label, isolate, identify secreted effectors. As first use BONCAT in an bacterium, our screen more than doubles number experimentally validated for . The novel factors (Srfs) we identified include -specific proteins unknown function localize cytoplasm, mitochondria, ER. further show one such effector, SrfD, interacts with Sec61 translocon. Altogether, work uncovers a diverse set previously uncharacterized lays foundation deeper exploration host-pathogen interface.

Language: Английский

Citations

3