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Scientific Reports Jan 2021The respiratory tracts of turkeys play important roles in the overall health and performance of the birds. Understanding the bacterial communities present in the...
The respiratory tracts of turkeys play important roles in the overall health and performance of the birds. Understanding the bacterial communities present in the respiratory tracts of turkeys can be helpful to better understand the interactions between commensal or symbiotic microorganisms and other pathogenic bacteria or viral infections. The aim of this study was the characterization of the bacterial communities of upper respiratory tracks in commercial turkeys using NGS sequencing by the amplification of 16S rRNA gene with primers designed for hypervariable regions V3 and V4 (MiSeq, Illumina). From 10 phyla identified in upper respiratory tract in turkeys, the most dominated phyla were Firmicutes and Proteobacteria. Differences in composition of bacterial diversity were found at the family and genus level. At the genus level, the turkey sequences present in respiratory tract represent 144 established bacteria. Several respiratory pathogens that contribute to the development of infections in the respiratory system of birds were identified, including the presence of Ornithobacterium and Mycoplasma OTUs. These results obtained in this study supply information about bacterial composition and diversity of the turkey upper respiratory tract. Knowledge about bacteria present in the respiratory tract and the roles they can play in infections can be useful in controlling, diagnosing and treating commercial turkey flocks.
Topics: Animals; Bacteria; Metagenome; Metagenomics; Microbiota; Respiratory Mucosa; Turkeys
PubMed: 33510238
DOI: 10.1038/s41598-021-81984-0 -
Microbiology Spectrum Apr 2016Invading pathogens are exposed to a multitude of harmful conditions imposed by the host gastrointestinal tract and immune system. Bacterial defenses against these... (Review)
Review
Invading pathogens are exposed to a multitude of harmful conditions imposed by the host gastrointestinal tract and immune system. Bacterial defenses against these physical and chemical stresses are pivotal for successful host colonization and pathogenesis. Enteric pathogens, which are encountered due to the ingestion of or contact with contaminated foods or materials, are highly successful at surviving harsh conditions to colonize and cause the onset of host illness and disease. Pathogens such as Campylobacter, Helicobacter, Salmonella, Listeria, and virulent strains of Escherichia have evolved elaborate defense mechanisms to adapt to the diverse range of stresses present along the gastrointestinal tract. Furthermore, these pathogens contain a multitude of defenses to help survive and escape from immune cells such as neutrophils and macrophages. This chapter focuses on characterized bacterial defenses against pH, osmotic, oxidative, and nitrosative stresses with emphasis on both the direct and indirect mechanisms that contribute to the survival of each respective stress response.
Topics: Adaptation, Physiological; Animals; Bacteria; Bacterial Physiological Phenomena; Defense Mechanisms; Gastrointestinal Tract; Humans; Microbial Viability; Stress, Physiological; Virulence
PubMed: 27227312
DOI: 10.1128/microbiolspec.VMBF-0007-2015 -
Applied and Environmental Microbiology Jun 1988The fibrolytic microbiota of the human large intestine was examined to determine the numbers and types of cellulolytic and hemicellulolytic bacteria present. Fecal...
The fibrolytic microbiota of the human large intestine was examined to determine the numbers and types of cellulolytic and hemicellulolytic bacteria present. Fecal samples from each of five individuals contained bacteria capable of degrading the hydrated cellulose in spinach and in wheat straw pretreated with alkaline hydrogen peroxide (AHP-WS), whereas degradation of the relatively crystalline cellulose in Whatman no. 1 filter paper (PMC) was detected for only one of the five samples. The mean concentration of cellulolytic bacteria, estimated with AHP-WS as a substrate, was 1.2 X 10(8)/ml of feces. Pure cultures of bacteria isolated on AHP-WS were able to degrade PMC, indicating that interactions with other microbes were primarily responsible for previous low success rates in detecting fecal cellulolytic bacteria with PMC as a substrate. The cellulolytic bacteria included Ruminococcus spp., Clostridium sp., and two unidentified strains. The mean concentration of hemicellulolytic bacteria, estimated with larchwood xylan as a substrate, was 1.8 X 10(10)/ml of feces. The hemicellulose-degrading bacteria included Butyrivibrio sp., Clostridium sp., Bacteroides sp., and two unidentified strains, as well as four of the five cellulolytic strains. This work demonstrates that many humans harbor intestinal cellulolytic bacteria and that a hydrated cellulose source such as AHP-WS is necessary for their consistent detection and isolation.
Topics: Adult; Bacteria; Bacteroides; Cellulose; Clostridium; Feces; Female; Fermentation; Humans; Intestine, Large; Male; Peptococcaceae; Polysaccharides
PubMed: 3415224
DOI: 10.1128/aem.54.6.1530-1535.1988 -
Toxins Oct 2010Microorganisms are ubiquitous in all habitats and are recognized by their metabolic versatility and ability to produce many bioactive compounds, including toxins. Some... (Review)
Review
Microorganisms are ubiquitous in all habitats and are recognized by their metabolic versatility and ability to produce many bioactive compounds, including toxins. Some of the most common toxins present in water are produced by several cyanobacterial species. As a result, their blooms create major threats to animal and human health, tourism, recreation and aquaculture. Quite a few cyanobacterial toxins have been described, including hepatotoxins, neurotoxins, cytotoxins and dermatotoxins. These toxins are secondary metabolites, presenting a vast diversity of structures and variants. Most of cyanobacterial secondary metabolites are peptides or have peptidic substructures and are assumed to be synthesized by non-ribosomal peptide synthesis (NRPS), involving peptide synthetases, or NRPS/PKS, involving peptide synthetases and polyketide synthases hybrid pathways. Besides cyanobacteria, other bacteria associated with aquatic environments are recognized as significant toxin producers, representing important issues in food safety, public health, and human and animal well being. Vibrio species are one of the most representative groups of aquatic toxin producers, commonly associated with seafood-born infections. Some enterotoxins and hemolysins have been identified as fundamental for V. cholerae and V. vulnificus pathogenesis, but there is evidence for the existence of other potential toxins. Campylobacter spp. and Escherichia coli are also water contaminants and are able to produce important toxins after infecting their hosts. Other bacteria associated with aquatic environments are emerging as toxin producers, namely Legionella pneumophila and Aeromonas hydrophila, described as responsible for the synthesis of several exotoxins, enterotoxins and cytotoxins. Furthermore, several Clostridium species can produce potent neurotoxins. Although not considered aquatic microorganisms, they are ubiquitous in the environment and can easily contaminate drinking and irrigation water. Clostridium members are also spore-forming bacteria and can persist in hostile environmental conditions for long periods of time, contributing to their hazard grade. Similarly, Pseudomonas species are widespread in the environment. Since P. aeruginosa is an emergent opportunistic pathogen, its toxins may represent new hazards for humans and animals. This review presents an overview of the diversity of toxins produced by prokaryotic microorganisms associated with aquatic habitats and their impact on environment, life and health of humans and other animals. Moreover, important issues like the availability of these toxins in the environment, contamination sources and pathways, genes involved in their biosynthesis and molecular mechanisms of some representative toxins are also discussed.
Topics: Animals; Bacteria; Humans; Toxins, Biological; Water Microbiology; Water Pollutants
PubMed: 22069558
DOI: 10.3390/toxins2102359 -
FEMS Microbiology Reviews Dec 2000Using high resolution molecular fingerprinting techniques like random amplification of polymorphic DNA, repetitive extragenic palindromic PCR and multilocus enzyme... (Review)
Review
Using high resolution molecular fingerprinting techniques like random amplification of polymorphic DNA, repetitive extragenic palindromic PCR and multilocus enzyme electrophoresis, a high bacterial diversity below the species and subspecies level (microdiversity) is revealed. It became apparent that bacteria of a certain species living in close association with different plants either as associated rhizosphere bacteria or as plant pathogens or symbiotic organisms, typically reflect this relationship in their genetic relatedness. The strain composition within a population of soil bacterial species at a given field site, which can be identified by these high resolution fingerprinting techniques, was markedly influenced by soil management and soil features. The observed bacterial microdiversity reflected the conditions of the habitat, which select for better adapted forms. In addition, influences of spatial separation on specific groupings of bacteria were found, which argue for the occurrence of isolated microevolution. In this review, examples are presented of bacterial microdiversity as influenced by different ecological factors, with the main emphasis on bacteria from the natural environment. In addition, information available from some of the first complete genome sequences of bacteria (Helicobacter pylori and Escherichia coli) was used to highlight possible mechanisms of molecular evolution through which mutations are created; these include mutator enzymes. Definitions of bacterial species and subspecies ranks are discussed in the light of detailed information from whole genome typing approaches.
Topics: Bacteria; Ecosystem; Evolution, Molecular; Plant Diseases; Plant Roots; Plants; Soil Microbiology
PubMed: 11077156
DOI: 10.1111/j.1574-6976.2000.tb00564.x -
FEMS Microbiology Reviews May 2009Pathogenic bacteria continuously encounter multiple forms of stress in their hostile environments, which leads to DNA damage. With the new insight into biology offered... (Review)
Review
Pathogenic bacteria continuously encounter multiple forms of stress in their hostile environments, which leads to DNA damage. With the new insight into biology offered by genome sequences, the elucidation of the gene content encoding proteins provides clues toward understanding the microbial lifestyle related to habitat and niche. Campylobacter jejuni, Haemophilus influenzae, Helicobacter pylori, Mycobacterium tuberculosis, the pathogenic Neisseria, Streptococcus pneumoniae, Streptococcus pyogenes and Staphylococcus aureus are major human pathogens causing detrimental morbidity and mortality at a global scale. An algorithm for the clustering of orthologs was established in order to identify whether orthologs of selected genes were present or absent in the genomes of the pathogenic bacteria under study. Based on the known genes for the various functions and their orthologs in selected pathogenic bacteria, an overview of the presence of the different types of genes was created. In this context, we focus on selected processes enabling genome dynamics in these particular pathogens, namely DNA repair, recombination and horizontal gene transfer. An understanding of the precise molecular functions of the enzymes participating in DNA metabolism and their importance in the maintenance of bacterial genome integrity has also, in recent years, indicated a future role for these enzymes as targets for therapeutic intervention.
Topics: Adaptation, Biological; Bacteria; Bacterial Infections; DNA Repair; DNA, Bacterial; Gene Transfer, Horizontal; Genome, Bacterial; Humans; Recombination, Genetic
PubMed: 19396949
DOI: 10.1111/j.1574-6976.2009.00173.x -
Microbiology Spectrum Jul 2019In this review, which is a part of the Curated Collection: Advances in Molecular Epidemiology of Infectious Diseases, I present an overview of the principles used to... (Review)
Review
In this review, which is a part of the Curated Collection: Advances in Molecular Epidemiology of Infectious Diseases, I present an overview of the principles used to classify organisms in the field of phylogenetics, highlight the methods used to infer the interrelationships of organisms, and summarize how these concepts are applied to molecular epidemiologic analyses. I present steps in analyses that come downstream of the assembly of a set of genomes or genes and the production of a multiple-sequence alignment or other matrices of putative orthologs for comparison. I focus on the history of the problem of phylogenetic reconstruction and debates within the field about the most appropriate methods. I illustrate methods that bridge the gap between molecular epidemiology and traditional epidemiology, including phylogenetic character evolution and geographic visualization. Finally, I provide practical advice on how to conduct an example analysis in the appendix. *This article is part of a curated collection.
Topics: Animals; Bacteria; Bacterial Infections; Communicable Diseases; Evolution, Molecular; Humans; Phylogeny; Virus Diseases; Viruses
PubMed: 31325287
DOI: 10.1128/microbiolspec.AME-0006-2018 -
Molecular Microbiology Mar 2002Present in the extracellular matrix and membranes of virtually all animal cells, proteoglycans (PGs) are among the first host macromolecules encountered by infectious... (Review)
Review
Present in the extracellular matrix and membranes of virtually all animal cells, proteoglycans (PGs) are among the first host macromolecules encountered by infectious agents. Because of their wide distribution and direct accessibility, it is not surprising that pathogenic bacteria have evolved mechanisms to exploit PGs for their own purposes, including mediating attachment to target cells. This is achieved through the expression of adhesins that recognize glycosaminoglycans (GAGs) linked to the core protein of PGs. Some pathogens, such as Bordetella pertussis and Chlamydia trachomatis, may express more than one GAG-binding adhesin. Bacterial interactions with PGs may also facilitate cell invasion or systemic dissemination, as observed for Neisseria gonorrhoeae and Mycobacterium tuberculosis respectively. More-over, pathogenic bacteria can use PGs to enhance their virulence via a shedding of PGs that leads to there lease of effectors that weaken the host defences. The exploitation of PGs by pathogenic bacteria is thus a multifaceted mechanistic process directly related to the potential virulence of a number of microorganisms.
Topics: Animals; Bacteria; Bacterial Infections; Glycosaminoglycans; Humans; Virulence
PubMed: 11971262
DOI: 10.1046/j.1365-2958.2002.02841.x -
Clinical Microbiology and Infection :... May 2004As recent external quality control results have shown, the diagnosis of Rothia dentocariosa infection still presents problems for clinical laboratories. This review... (Review)
Review
As recent external quality control results have shown, the diagnosis of Rothia dentocariosa infection still presents problems for clinical laboratories. This review describes the taxonomy, as well as the chemotaxonomic, morphological and biochemical characteristics, of this organism, and surveys bacteria that may be confused with Rothia dentocariosa.
Topics: Actinomycetales Infections; Bacteriological Techniques; Diagnosis, Differential; Humans; Micrococcaceae; Phylogeny
PubMed: 15113315
DOI: 10.1111/j.1469-0691.2004.00784.x -
Parasites & Vectors May 2024Gut bacteria, which serve as essential modulators, exert a significant impact on insect physiology and behavior and have substantial application potential in pest...
BACKGROUND
Gut bacteria, which serve as essential modulators, exert a significant impact on insect physiology and behavior and have substantial application potential in pest management. The dynamics of gut bacteria and their impact on Phortica okadai behavior remain unclear.
METHODS
In this study, the dynamics of gut bacteria at different developmental stages in P. okadai were analyzed using 16S ribosomal RNA (rRNA) gene sequencing, and the species and abundance of gut bacteria that affect host behavior were examined via behavioral experiments.
RESULTS
A total of 19 phyla, 29 classes, 74 orders, 101 species, and 169 genera were identified. The results of the behavioral experiments indicated that the species Lactiplantibacillus argentoratensis, Acetobacter tropicalis, Leuconostoc citreum, and Levilactobacillus brevis effectively influenced the feeding preference of P. okadai, and the single-bacterium-seeded P. okadai exhibited feeding preferences distinct from those of the germ-free (GF) and wild-type P. okadai.
CONCLUSIONS
The species and relative abundance of gut bacteria together positively impact P. okadai behavior. Lactiplantibacillus argentoratensis, as the most attractive bacteria to P. okadai, presents opportunities for novel pest control strategies targeting this vector and agricultural pest.
Topics: Animals; Gastrointestinal Microbiome; Bacteria; RNA, Ribosomal, 16S; Behavior, Animal; Feeding Behavior; Tephritidae
PubMed: 38734668
DOI: 10.1186/s13071-024-06297-3