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Virulence Dec 2021Mycoplasmas, the smallest bacteria lacking a cell wall, can cause various diseases in both humans and animals. Mycoplasmas harbor a variety of virulence factors that... (Review)
Review
Mycoplasmas, the smallest bacteria lacking a cell wall, can cause various diseases in both humans and animals. Mycoplasmas harbor a variety of virulence factors that enable them to overcome numerous barriers of entry into the host; using accessory proteins, mycoplasma adhesins can bind to the receptors or extracellular matrix of the host cell. Although the host immune system can eradicate the invading mycoplasma in most cases, a few sagacious mycoplasmas employ a series of invasion and immune escape strategies to ensure their continued survival within their hosts. For instance, capsular polysaccharides are crucial for anti-phagocytosis and immunomodulation. Invasive enzymes degrade reactive oxygen species, neutrophil extracellular traps, and immunoglobulins. Biofilm formation is important for establishing a persistent infection. During proliferation, successfully surviving mycoplasmas generate numerous metabolites, including hydrogen peroxide, ammonia and hydrogen sulfide; or secrete various exotoxins, such as community-acquired respiratory distress syndrome toxin, and hemolysins; and express various pathogenic enzymes, all of which have potent toxic effects on host cells. Furthermore, some inherent components of mycoplasmas, such as lipids, membrane lipoproteins, and even mycoplasma-generated superantigens, can exert a significant pathogenic impact on the host cells or the immune system. In this review, we describe the proposed virulence factors in the toolkit of notorious mycoplasmas to better understand the pathogenic features of these bacteria, along with their pathogenic mechanisms.
Topics: Animals; Biofilms; Host-Pathogen Interactions; Humans; Mice; Mycoplasma; Phagocytosis; Virulence; Virulence Factors
PubMed: 33704021
DOI: 10.1080/21505594.2021.1889813 -
Plant Disease Jul 2023Corynespora leaf spot, which is caused by (Berk. & M. A. Curtis) C.T. Wei (), has been globally reported in many plant species. 'Hongyang' was reported as highly...
Corynespora leaf spot, which is caused by (Berk. & M. A. Curtis) C.T. Wei (), has been globally reported in many plant species. 'Hongyang' was reported as highly sensitive kiwifruit cultivar to . This cultivar is an important germplasm resource in the Actinidiaceae family and is widely cultivated throughout China. Even though has been identified as the pathogen associated with kiwifruits in China, the population from kiwifruit has not been characterized based on morphology, phylogeny, and pathogenicity. In this study, 133 and 48 representative isolates from kiwifruit and 11 other hosts, respectively, recovered from symptomatic leaves were classified into eight morphological subgroups based on host origins. Using three loci (rDNA ITS, , and ), a phylogenetic tree showed that isolates in Sichuan Province were grouped into three clades. All kiwifruit isolates were genetically identical to the rubber isolates from different countries. However, most isolates from other hosts in this study were genetically identical to the cucumber, soybean, and cowpea isolates in China, Brazil, and the United States, and two strawberry isolates clustered with isolates from tomato and other hosts in China, Brazil, and the United States. Furthermore, we confirmed host shift of among different plant species in this study. Although 51 isolates from kiwifruit and different hosts were pathogenic to kiwifruit, blueberry, cucumber, and soybean, virulence levels of the pathogen were diverse for four hosts. Kiwifruit isolates exhibited host specificity with regards to the original host in degree. In addition, those isolates revealed a correlation between morphology and pathogenicity. The results suggest that in Sichuan Province were derived from three different phylogenetic lineages. Promotion of the susceptible 'Hongyang' cultivar led to the emergence of a regnant population from kiwifruit. In conclusion, rapid development of the -sensitive crop in agricultural systems led to the emergence of a regnant population. In some dominant populations (e.g., the population from kiwifruit in this study), host origin was found to be a key factor influencing the morphologic, genetic, and pathogenic characterization of .
Topics: Virulence; Phylogeny; Plant Diseases; Ascomycota; Cucumis sativus
PubMed: 36475741
DOI: 10.1094/PDIS-04-22-0937-RE -
BMC Veterinary Research Jul 2022Pasteurella multocida is one of the most significant pathogens for a number of animals. In rabbits, the infection is generally associated with the P. multocida...
BACKGROUND
Pasteurella multocida is one of the most significant pathogens for a number of animals. In rabbits, the infection is generally associated with the P. multocida serogroups A and D, and the knowledge about the serogroup F is limited. In the present study, a P. multocida serogroup F isolate designated s4 was recovered from the lungs of rabbits died of respiratory disease in Fujian, in the southeast of China. The pathogenicity and genomic features of the s4 were then determined.
RESULTS
The serotype and sequence type of s4 were F:L3 and ST12, respectively. The s4 was pathogenic for rabbits, but it was a low virulent strain comparing to the previously reported highly pathogenic P. multocida serogroup F strains J-4103, C21724H3km7, P-4218 and HN07. The whole genome of the s4 was then sequenced to understand the genomic basis for pathogenicity. Particularly, a large-sized fragment of approximate 275 kb in length was truncated from the chromosome to form a plasmid. Moreover, the in-frame deletion of natC and N-terminal redundance of gatF would resulted in the production of a mutant L3 outer core structure that was distinct from those of the other P. multocida strains belonging to the lipopolysaccharide genotype L3. We deduced that these features detected in the genome of s4 might impair the pathogenicity of the bacterium.
CONCLUSIONS
This study evaluated the pathogenicity and determined the genomic features of the rabbit sourced P. multocida serogroup F isolate s4, the observations and findings would helpful for the understanding of the pathogenicity variability and genetic diversity of P. multocida.
Topics: Animals; Genomics; Pasteurella Infections; Pasteurella multocida; Rabbits; Serogroup; Virulence
PubMed: 35869529
DOI: 10.1186/s12917-022-03381-7 -
Biomolecules Jun 2021Bacterial secretory systems are essential for virulence in human pathogens. The systems have become a target of alternative antibacterial strategies based on small... (Review)
Review
Bacterial secretory systems are essential for virulence in human pathogens. The systems have become a target of alternative antibacterial strategies based on small molecules and antibodies. Strategies to use components of the systems to design prophylactics have been less publicized despite vaccines being the preferred solution to dealing with bacterial infections. In the current review, strategies to design vaccines against selected pathogens are presented and connected to the biology of the system. The examples are given for , , , , and other human pathogens, and discussed in terms of effectiveness and long-term protection.
Topics: Bacteria; Bacterial Infections; Bacterial Proteins; Bacterial Secretion Systems; Bacterial Vaccines; Humans; Virulence
PubMed: 34203937
DOI: 10.3390/biom11060892 -
Molecular Biology Reports Feb 2022Phytophthora cinnamomi is classified as one of the most devastating plant pathogens in the world. It has a destructive effect on more than 5000 horticultural and... (Review)
Review
Phytophthora cinnamomi is classified as one of the most devastating plant pathogens in the world. It has a destructive effect on more than 5000 horticultural and forestry species in the world, and especially on Castanea sativa. The genus Phytophthora belongs to the Class Oomycetes, a group of fungus like organisms which provoke plant diseases via motile zoospores. Control of this organism is considered very challenging because of the limited range of effective chemical inhibitors. The development of sustainable control measures for the future management of P. cinnamomi requires in-depth knowledge of the cellular and molecular bases of development and metabolism. The aim of this review was to identify molecular factors associated with the metabolism of P. cinnamomi by studying the genes implicated in fundamental metabolism using tools of bioinformatics. Also, some genes involved in pathogenicity will be cited and characterized, such as genes coding for transglycosylases. Genomic sequences of P. cinnamomi were analyzed using an open reading frame (ORF) finder. The identified ORFs products (proteins) were compared to sequences already described and with known functions present in databases such as NCBI and fungi database. In this way, homologous proteins were found, with the respective specific domains, to proteins involved in the metabolism and pathogenicity of Phytophthora ssp.
Topics: Computational Biology; Computer Simulation; Genomics; Phytophthora; Plant Diseases; Plant Roots; Virulence
PubMed: 34751913
DOI: 10.1007/s11033-021-06901-0 -
Trends in Microbiology May 2020Bacterial pathogens employ diverse fitness and virulence mechanisms to gain an advantage in competitive niches. These lifestyle-specific traits require integration into... (Review)
Review
Bacterial pathogens employ diverse fitness and virulence mechanisms to gain an advantage in competitive niches. These lifestyle-specific traits require integration into the regulatory network of the cell and are often controlled by pre-existing transcription factors. In this review, we highlight recent advances that have been made in characterizing this regulatory flexibility in prominent members of the Enterobacteriaceae. We focus on the direct global interactions between transcription factors and their target genes in pathogenic Escherichia coli and Salmonella revealed using chromatin immunoprecipitation coupled with next-generation sequencing. Furthermore, the implications and advantages of such regulatory adaptations in benefiting distinct pathogenic lifestyles are discussed.
Topics: Chromatin Immunoprecipitation; Escherichia coli; Escherichia coli Infections; Gene Expression Regulation, Bacterial; High-Throughput Nucleotide Sequencing; Salmonella; Salmonella Infections; Transcription Factors; Transcription, Genetic; Virulence
PubMed: 32298614
DOI: 10.1016/j.tim.2020.01.002 -
International Journal of Molecular... Feb 2023The growth-defense trade-off in plants is a phenomenon whereby plants must balance the allocation of their resources between developmental growth and defense against... (Review)
Review
The growth-defense trade-off in plants is a phenomenon whereby plants must balance the allocation of their resources between developmental growth and defense against attack by pests and pathogens. Consequently, there are a series of points where growth signaling can negatively regulate defenses and where defense signaling can inhibit growth. Light perception by various photoreceptors has a major role in the control of growth and thus many points where it can influence defense. Plant pathogens secrete effector proteins to manipulate defense signaling in their hosts. Evidence is emerging that some of these effectors target light signaling pathways. Several effectors from different kingdoms of life have converged on key chloroplast processes to take advantage of regulatory crosstalk. Moreover, plant pathogens also perceive and react to light in complex ways to regulate their own growth, development, and virulence. Recent work has shown that varying light wavelengths may provide a novel way of controlling or preventing disease outbreaks in plants.
Topics: Plants; Light Signal Transduction; Signal Transduction; Virulence; Chloroplasts; Plant Diseases; Plant Immunity
PubMed: 36835216
DOI: 10.3390/ijms24043803 -
PeerJ 2022Pathogen accumulation after introduction is unavoidable for exotic plants over a long period of time. Therefore, it is important to understand whether plant invasion...
Pathogen accumulation after introduction is unavoidable for exotic plants over a long period of time. Therefore, it is important to understand whether plant invasion promotes novel pathogen emergence and increases the risk of pathogen movement among agricultural, horticultural, and wild native plants. In this study, we used multiple gene analysis to characterize the species composition of 104 isolates of obtained from the invasive plant and native plants from Yunnan, Hubei, Guizhou, Sichuan, and Guangxi in China. Phylogenetically, these strains were from (88.5%), (10.6%) and (0.9%). There was a high amount of sharing between strains associated with and with local plants. Pathogenicity tests indicated that most of these strains are generalists; the isolates with a wider host range were more virulent to the plant. Woody plants were more resistant to these strains than herbaceous plants and vines. However, the invasive plant was highly sensitive to these strains. Our data are valuable for understanding how invasion impacts the species composition of the native plant and whether invasion causes potential disease risks in invaded ecosystems.
Topics: Ageratina; Alternaria; Ecosystem; Introduced Species; Virulence; China; Plants
PubMed: 35251785
DOI: 10.7717/peerj.13012 -
International Journal of Biological... May 2022Plant pathogenic fungi encode and secrete effector proteins to promote pathogenesis. In recent years, the important role of effector proteins in fungi and plant host... (Review)
Review
Plant pathogenic fungi encode and secrete effector proteins to promote pathogenesis. In recent years, the important role of effector proteins in fungi and plant host interactions has become increasingly prominent. In this review, the functional characterization and molecular mechanisms by which fungal effector proteins modulate biological processes and suppress the defense of plant hosts are discussed, with an emphasis on cell localization during fungal infection. This paper also provides a comprehensive review of bioinformatic and experimental methods that are currently available for the identification of fungal effector proteins. We additionally summarize the secretion pathways and the methods for verifying the presence effector proteins in plant host cells. For future research, comparative genomic studies of different pathogens with varying life cycles will allow comprehensive and systematic identification of effector proteins. Additionally, functional analysis of effector protein interactions with a wider range of hosts (especially non-model crops) will provide more detailed repertoires of fungal effectors. Identifying effector proteins and verifying their functions will improve our understanding of their role in causing disease and in turn guide future strategies for combatting fungal infections.
Topics: Crops, Agricultural; Fungal Proteins; Fungi; Host-Pathogen Interactions; Plant Diseases; Virulence
PubMed: 35227707
DOI: 10.1016/j.ijbiomac.2022.02.133 -
Methods in Molecular Biology (Clifton,... 2020An essential property associated with leptospiral virulence is the pathogen's ability to translocate across host cells, enabling Leptospira to evade the host immune...
An essential property associated with leptospiral virulence is the pathogen's ability to translocate across host cells, enabling Leptospira to evade the host immune response, disseminate, and establish infection. Cell monolayer translocation assay allows for the quantification of Leptospira strain's competence to cross cell barriers while measuring the integrity of the polarized eukaryotic cell monolayer during this process.
Topics: Animals; Biological Assay; Cell Line; Cell Movement; Cell Polarity; Dogs; Eukaryotic Cells; Leptospira; Leptospirosis; Madin Darby Canine Kidney Cells; Virulence
PubMed: 32632868
DOI: 10.1007/978-1-0716-0459-5_15