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Poultry Science Apr 2005Successful control of foodborne pathogens requires placement of chemical and physical hurdles in the preharvest and postharvest food production sectors. Pathogens may... (Review)
Review
Successful control of foodborne pathogens requires placement of chemical and physical hurdles in the preharvest and postharvest food production sectors. Pathogens may also encounter indigenous antimicrobials in foods including certain botanical compounds that have historically been used for flavor enhancement as well as preservation. Chemical additives have traditionally included organic acids to control microbial contamination in foods and feeds. However, there is some concern that continuous application of certain chemical antimicrobials can lead to a buildup of microbial resistance. This creates problems if foodborne pathogens survive and develop resistance to a variety of environmental stressors encountered in pre- and postharvest animal production. To expand the diversity of potential antimicrobials that have practical application to food animal production requires exploring the interaction between the food matrix and foodborne pathogens. There is potential for isolating antimicrobial compounds that exhibit mechanisms unrelated to conventional antimicrobial compounds. However, understanding the potential for novel antimicrobial compounds in foods and feeds will require the physiological examination of foodborne pathogen response under experimental conditions comparable to the environment where the pathogen is most likely to occur. Research on foodborne Salmonella pathogenesis is extensive and should provide a model for detailed examination of the factors that influence antimicrobial effectiveness. Analysis of pathogen response to antimicrobials could yield clues for optimizing hurdle technologies to more effectively exploit vulnerabilities of Salmonella and other foodborne pathogens when administering antimicrobials during food and feed production.
Topics: Animal Feed; Animals; Anti-Bacterial Agents; Food Microbiology; Salmonella; Salmonella Infections, Animal; Virulence
PubMed: 15844827
DOI: 10.1093/ps/84.4.667 -
ACS Infectious Diseases Jan 2020Natural products from microorganisms are important small molecules that play roles in various biological processes like cellular growth, motility, nutrient acquisition,... (Review)
Review
Natural products from microorganisms are important small molecules that play roles in various biological processes like cellular growth, motility, nutrient acquisition, stress response, biofilm formation, and defense. It is hypothesized that pathogens exploit these molecules to regulate virulence and persistence during infections. Here, we present selected examples of signaling natural products from human pathogenic bacteria that use these metabolites to gain a competitive advantage. Targeting these signaling systems provides novel strategies to antimicrobial treatments.
Topics: Animals; Anti-Bacterial Agents; Bacteria; Biological Products; Host Microbial Interactions; Humans; Secondary Metabolism; Signal Transduction; Virulence
PubMed: 31617342
DOI: 10.1021/acsinfecdis.9b00286 -
Genes Jul 2021RNA modifications are involved in numerous biological processes and are present in all RNA classes. These modifications can be constitutive or modulated in response to... (Review)
Review
RNA modifications are involved in numerous biological processes and are present in all RNA classes. These modifications can be constitutive or modulated in response to adaptive processes. RNA modifications play multiple functions since they can impact RNA base-pairings, recognition by proteins, decoding, as well as RNA structure and stability. However, their roles in stress, environmental adaptation and during infections caused by pathogenic bacteria have just started to be appreciated. With the development of modern technologies in mass spectrometry and deep sequencing, recent examples of modifications regulating host-pathogen interactions have been demonstrated. They show how RNA modifications can regulate immune responses, antibiotic resistance, expression of virulence genes, and bacterial persistence. Here, we illustrate some of these findings, and highlight the strategies used to characterize RNA modifications, and their potential for new therapeutic applications.
Topics: Bacteria; Host Adaptation; Host-Pathogen Interactions; RNA Processing, Post-Transcriptional; RNA, Bacterial; Virulence
PubMed: 34440299
DOI: 10.3390/genes12081125 -
Biological Reviews of the Cambridge... Nov 2004Recent studies have provided evolutionary explanations for much of the variation in mortality among human infectious diseases. One gap in this knowledge concerns... (Review)
Review
Recent studies have provided evolutionary explanations for much of the variation in mortality among human infectious diseases. One gap in this knowledge concerns respiratory tract pathogens transmitted from person to person by direct contact or through environmental contamination. The sit-and-wait hypothesis predicts that virulence should be positively correlated with durability in the external environment because high durability reduces the dependence of transmission on host mobility. Reviewing the epidemiological and medical literature, we confirm this prediction for respiratory tract pathogens of humans. Our results clearly distinguish a high-virulence high-survival group of variola (smallpox) virus, Mycobacterium tuberculosis, Cornynebacterium diphtheriae, Bordetella pertussis, Streptococcus pneumoniae, and influenza virus (where all pathogens have a mean percent mortality > or = 0.01% and mean survival time >10 days) from a low-virulence low-survival group containing ten other pathogens. The correlation between virulence and durability explains three to four times of magnitude of difference in mean percent mortality and mean survival time, using both across-species and phylogenetically controlled analyses. Our findings bear on several areas of active research and public health policy: (1) many pathogens used in the biological control of insects are potential sit-and-wait pathogens as they combine three attributes that are advantageous for pest control: high virulence, long durability after application, and host specificity; (2) emerging pathogens such as the 'hospital superbug' methicillin-resistant Staphylococcus aureus (MRSA) and potential bioweapons pathogens such as smallpox virus and anthrax that are particularly dangerous can be discerned by quantifying their durability; (3) hospital settings and the AIDS pandemic may provide footholds for emerging sit-and-wait pathogens; and (4) studies on food-borne and insect pathogens point to future research considering the potential evolutionary trade-offs and genetic linkages between virulence and durability.
Topics: Animals; Bacteria; Disease Transmission, Infectious; Evolution, Molecular; Humans; Mortality; Time Factors; Virulence; Viruses
PubMed: 15682873
DOI: 10.1017/s1464793104006475 -
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 Plant Pathology Feb 2022Decay due to fungal infection is a major cause of postharvest losses in fruits. Acidic fungi may enhance their virulence by locally reducing the pH of the host. Several... (Review)
Review
Decay due to fungal infection is a major cause of postharvest losses in fruits. Acidic fungi may enhance their virulence by locally reducing the pH of the host. Several devastating postharvest fungi, such as Penicillium spp., Botrytis cinerea, and Sclerotinia sclerotiorum, can secrete gluconic acid, oxalic acid, or citric acid. Emerging evidence suggests that organic acids secreted by acidic fungi are important virulence factors. In this review, we summarized the research progress on the biosynthesis of organic acids, the role of the pH signalling transcription factor PacC in regulating organic acid, and the action mechanism of the main organic acid secreted via postharvest pathogenic fungi during infection of host tissues. This paper systematically demonstrates the relationships between tissue acidification and postharvest fungal pathogenicity, which will motivate the study of host-pathogen interactions and provide a better understanding of virulence mechanisms of the pathogens so as to design new technical strategies to prevent postharvest diseases.
Topics: Fruit; Fungi; Host-Pathogen Interactions; Penicillium; Virulence; Virulence Factors
PubMed: 34820999
DOI: 10.1111/mpp.13159 -
Current Opinion in Insect Science Aug 2016Bees are important pollinators of plants in both agricultural and non-agricultural landscapes. Recent losses of both managed and wild bee species have negative impacts... (Review)
Review
Bees are important pollinators of plants in both agricultural and non-agricultural landscapes. Recent losses of both managed and wild bee species have negative impacts on crop production and ecosystem diversity. Therefore, in order to mitigate bee losses, it is important to identify the factors most responsible. Multiple factors including pathogens, agrochemical exposure, lack of quality forage, and reduced habitat affect bee health. Pathogen prevalence is one factor that has been associated with colony losses. Numerous pathogens infect bees including fungi, protists, bacteria, and viruses, the majority of which are RNA viruses including several that infect multiple bee species. RNA viruses readily infect bees, yet there is limited understanding of their impacts on bee health, particularly in the context of other stressors. Herein we review the influence environmental factors have on the replication and pathogenicity of bee viruses and identify research areas that require further investigation.
Topics: Agriculture; Animals; Bees; Ecosystem; Virulence; Virus Physiological Phenomena; Virus Replication
PubMed: 27720045
DOI: 10.1016/j.cois.2016.04.009 -
Molecular Biology of the Cell Dec 2015One quarter of all deaths worldwide each year result from infectious diseases caused by microbial pathogens. Pathogens infect and cause disease by producing virulence...
One quarter of all deaths worldwide each year result from infectious diseases caused by microbial pathogens. Pathogens infect and cause disease by producing virulence factors that target host cell molecules. Studying how virulence factors target host cells has revealed fundamental principles of cell biology. These include important advances in our understanding of the cytoskeleton, organelles and membrane-trafficking intermediates, signal transduction pathways, cell cycle regulators, the organelle/protein recycling machinery, and cell-death pathways. Such studies have also revealed cellular pathways crucial for the immune response. Discoveries from basic research on the cell biology of pathogenesis are actively being translated into the development of host-targeted therapies to treat infectious diseases. Thus there are many reasons for cell biologists to incorporate the study of microbial pathogens into their research programs.
Topics: Animals; Bacteria; Cell Biology; Host-Pathogen Interactions; Humans; Infections; Mice; Parasites; Signal Transduction; Virulence; Viruses
PubMed: 26628749
DOI: 10.1091/mbc.E15-03-0144 -
Essays in Biochemistry Sep 2022Pathogenic fungi use diverse infection strategies to obtain nutrients from plants. Biotrophic fungi feed only on living plant tissue, whereas necrotrophic fungi kill... (Review)
Review
Pathogenic fungi use diverse infection strategies to obtain nutrients from plants. Biotrophic fungi feed only on living plant tissue, whereas necrotrophic fungi kill host cells to extract nutrients. To prevent disease, plants need to distinguish between pathogens with different life cycles, as a successful defense against a biotroph, which often involves programmed cell-death around the site of infection, is not an appropriate response to some necrotrophs. Plants utilize a vast collection of extracellular and intracellular receptors to detect the signatures of pathogen attack. In turn, pathogens are under strong selection to mask or avoid certain receptor responses while enhancing or manipulating other receptor responses to promote virulence. In this review, we focus on the plant receptors involved in resistance responses to fungal pathogens and highlight, with examples, how the infection strategy of fungal pathogens can determine if recognition responses are effective at preventing disease.
Topics: Fungi; Plant Diseases; Plant Immunity; Plants; Virulence
PubMed: 35587147
DOI: 10.1042/EBC20210073 -
Frontiers in Cellular and Infection... 2018Iron is an absolute requirement for both the host and most pathogens alike and is needed for normal cellular growth. The acquisition of iron by biological systems is... (Review)
Review
Iron is an absolute requirement for both the host and most pathogens alike and is needed for normal cellular growth. The acquisition of iron by biological systems is regulated to circumvent toxicity of iron overload, as well as the growth deficits imposed by iron deficiency. In addition, hosts, such as humans, need to limit the availability of iron to pathogens. However, opportunistic pathogens such as are able to adapt to extremes of iron availability, such as the iron replete environment of the gastrointestinal tract and iron deficiency during systemic infection. has developed a complex and effective regulatory circuit for iron acquisition and storage to circumvent iron limitation within the human host. As can form complex interactions with both commensal and pathogenic co-inhabitants, it can be speculated that iron may play an important role in these interactions. In this review, we highlight host iron regulation as well as regulation of iron homeostasis in . In addition, the review argues for the need for further research into the role of iron in polymicrobial interactions. Lastly, the role of iron in treatment of infection is discussed.
Topics: Candida albicans; Candidiasis; Gastrointestinal Tract; Gene Expression Regulation, Fungal; Homeostasis; Host-Pathogen Interactions; Humans; Immunity; Iron; Microbial Interactions; Symbiosis; Virulence
PubMed: 29922600
DOI: 10.3389/fcimb.2018.00185