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  1. Pathogenic bacteria are bacteria that can cause disease. This article deals with human pathogenic bacteria. Although most bacteria are harmless or often beneficial, some are pathogenic, with the number of species estimated as fewer than a hundred that are seen to cause infectious diseases in humans.

    Pathogenic bacteria - Wikipedia
  2. Pathogenic bacteria - Wikipedia

    Pathogenic bacteria are bacteria that can cause disease. This article deals with human pathogenic bacteria. Although most bacteria are harmless or often beneficial, some are pathogenic, with the number of species estimated as fewer than a hundred that are seen to cause infectious diseases in humans.

    Actinomycosis: painful abscesses in the mouth, lungs, or gastrointestinal tract.
    Contact with cattle, sheep, goats and horses Spores enter through inhalation or through abrasions
    Anthrax: pulmonary, gastrointestinal and/or cutaneous symptoms.
    Abscesses in gastrointestinal tract, pelvic cavity and lungs
    Contact with respiratory droplets expelled by infected human hosts.
    Whooping cough Secondary bacterial pneumonia
  3. What is a Pathogen? 4 Types and How They Spread Disease

    Apr 03, 2019 · The disease state caused by a virus enables normally harmless bacteria to become pathogenic. Antibiotics are used to treat bacterial infections. Some strains of bacteria have become resistant to ...

    • Adrienne Santos-Longhurst
  4. Pathogenic Bacteria List - Health Hearty

    These bacteria that cause health problems are called human pathogenic bacteria. These disease-causing bacteria can also gain entry into the body through food, water, air, saliva, and other body fluids. Given below is a list of pathogenic bacteria along with the diseases they cause.

    • What Are Pathogens? | Health | Biology | FuseSchool
    • Rapid Detection of Pathogenic Bacteria
    • Pathogens
    • Studying Pathogenic Bacteria
  5. List of Common Pathogenic Bacteria That Affect the Human Body ...

    Dec 18, 2018 · Bacteria are all around us, in the air, on objects and normally found in and on the human body. When bacteria is on the human body in the absence of disease, it is called a colonizer. However, people can get infected from pathogenic bacteria from food, water, abrasions and other wounds and even from colonizing bacteria if it gets into a ...

  6. Pathogenic bacteria and infectious diseases. What are bacteria?

    Pathogenic bacteria can contribute to many worldwide diseases, including tuberculosis, cholera, anthrax, leprosy, the bubonic plague, pneumonia, and food-borne illnesses. The most common fatal bacterial infectious diseases are respiratory infections, with tuberculosis (caused by the bacteria Mycobacterium tuberculosis ) killing approximately ...

  7. What is Pathogenic Bacteria? (with pictures)

    Sep 21, 2020 · Pathogenic bacteria are also responsible for intestinal problems such as chronic diarrhea, and they can cause infections in many parts of the body. Some are deadly, like the Legionella bacterium, while others are relatively benign, especially if treatment can be accessed.

  8. Pathogens: Definition, types, diseases, prevention, and more

    Aug 21, 2020 · About 300 species of fungi are pathogenic to humans. As with bacteria and viruses, they can have a significant effect on human health. Fungi cause many different types of illness, including:

  9. Pathogen - Wikipedia

    Even pathogenic bacteria that infect other species, including humans, can be infected with a phage. Plants. Plants can play host to a wide range of pathogen types including viruses, bacteria, fungi, nematodes, and even other plants.

  10. Bacteria as Plant Pathogens
    • Frontiers: Current and Future Areas of Inquiry
    • Basic Biology
    • Reproduction
    • Systematics
    • Survival
    • Dissemination
    • Host-Pathogen Interactions
    • Symptomatology
    • Diagnosis
    • Epidemiology and Management

    The most exciting and current areas of research on plant-associated bacteria are the result of new intellectual discoveries, analyses and fields of study, new techniques and new instrumentation unavailable even a decade ago. For example, genomic sequencing, or the ordered reading of thousands of nucleotides constituting the deoxyribonucleic acid (DNA) of an organism, is now relatively common. Yet, of more than 166 sequenced and published bacterial genomes (National Center for Biotechnology Information/NCBI 2004) not including Archaea, at this time only eight are plant pathogens. Along with sequencing and its enormous data accumulation has arisen the field of bioinformatics to enable communication among scientists and analyses of the data, particularly comparative and evolutionary studies. Even supposedly simple steps like annotation of a gene, or its name or function, remains a challenge. The American Phytopathological Society has made a case of the need for additional bacteria to b...

    Bacteria associated with plants have several morphological shapes as can be seen with conventional microscopes at 400x to 1000x magnification. These shapes initially provided simple ways to differentiate them. There are bacilli (rods), cocci (spherical), pleomorphic rods (tendency toward irregular shapes) and spiral shapes. The majority of plant-associated bacteria are rods. However, modern science has shown by biochemical, genetic and molecular biological analyses that these bacteria are quite heterogeneous. Some are related to and grouped with animal and human pathogens. By different types of microscopy (Basic Microscopy), principally fluorescent, confocal, phase-contrast and electron microscopy, one can see different parts of bacterial cells (Figure 8). Stains are often useful in the differentiation of structures. Chromosomes composed of DNA are coiled and there may be more than one per cell. Plasmids, or extra-chromosomal genomic entities may be present, and can code for essenti...

    In general, bacteria reproduce by binary fission (one cell splitting into two), but the process is complex. If present, the extrachromosomal DNA elements or plasmids are usually reproduced in synchrony with the bacterial chromosome, but under some conditions can be lost naturally or by chemical manipulation ('cured'). Many plant pathogens harbor plasmids, e.g. strains of Pantoea (syn: Erwinia) stewartii subsp. stewartii (Stewart's wilt of corn disease lesson) may have up to 13 plasmids of unknown function (Coplin et al. 1981). Genetic variation in natural settings, e.g. fields, is probably underestimated due to lack of sampling and characterization. For example, at least seven pathogenic variants of the Goss's wilt and blight bacterium of corn, Clavibacter michiganensis subsp. nebraskensis(Smidt and Vidaver 1987), have been detected in a single field. Horizontal transfer, the passage of DNA from one bacterial cell to another, may be accomplished in the laboratory and is assumed to a...

    Most of the plant pathogenic bacteria are either Gram-positive, classified within the Phylum Actinobacteria, or Gram-negative, in the Phylum Proteobacteria. Gram-positive and Gram-negative cells appear purple or red, respectively, with specific stains when viewed at 1000x magnification with a light microscope (Figure 12). The different colors largely reflect differences in stain retention by the respective cell walls of the bacteria during the staining process. Further differentiation is based on chemical or physiological characteristics, e.g. cell wall composition, enzyme production, substrate utilization, etc. Molecular characterization of 16S ribosomal RNA also may distinguish bacteria from one another. Ribosomes are coded by a highly conserved part of the bacterial chromosome and represent only a small part of the genome. But, the 'gold standard' for determining phylogenetic relationships is DNA:DNA homology by hybridization or genomic sequencing. Such analyses are sometimes at...

    Survival of plant pathogenic bacteria in nature occurs most commonly in plant debris left on the soil surface, in and on seeds, in soil, and in association with perennial hosts. But some bacteria can also survive in water and some do well on inanimate objects or on or inside insects. Clavibacter michiganensis subsp. sepedonicus, causative agent of potato ring rot, is notoriously known for surviving on machinery and packaging material. Knowledge of survival is usually essential to intervene in dissemination and for disease management. return to top

    Dissemination of plant pathogenic bacteria is easy, but fortunately does not always result in disease. Dissemination commonly occurs by windblown soil and sand particles that cause plant wounding, particularly during or after rains or storms (Figure 13). Wounding is essential for entry by many plant pathogens. Aerosols generated by diurnal temperature fluctuations enable dissemination, if temperature and humidity are aligned (Hirano and Upper 1989). Some plant diseases require certain temperature conditions e.g. Pseudomonas syringae (synonym: P. savastanoi) pv. phaseolicola causes disease below 22°C (72 °F) and Xanthomonas campestris (syn: X. axonopodis) pv. phaseoli, above 22°C on dry bean (Phaseolus vulgaris). Both diseases can occur simultaneously under growth conditions in which day and night temperature differentials enable disease progression in susceptible plants. Infested (surface contamination) or infected seed or any plant part can be sources of bacterial inoculum. Machine...

    Infection of plants by bacteria can occur in multiple ways. Infection is generally considered to be passive, i.e. accidental, although a few cases of plant chemoattractants have been reported. Bacteria can be sucked into a plant through natural plant openings such as stomata, hydathodes or lenticels. They can enter through abrasions or wounds on leaves, stems or roots or through placement by specific feeding insects. The nutrient conditions in plants may be such as to favor multiplication in different plant parts e.g. flowers or roots. Wind-driven rain carrying inoculum can be highly effective. Artificially, bacteria are most commonly introduced into plants by wounding, by pressure-driven aerosols mimicking wind-driven rains, vacuum infiltration, or by seed immersion into inoculum. return to top

    Symptomatology of bacterial diseases is extremely varied, but usually characteristic for a particular pathogen. Symptoms can range from mosaics, resembling viral infections, to large plant abnormalities, such as galls or distorted plant parts. Hormone disruption can produce characteristic abnormal growths on roots, stems, and floral structures (phyllody) and sometimes abnormal flower colors (virescence). The most common symptoms are spots on leaves (Figure 14) or fruit (Figure 15), blights or deadening of tissue on leaves, stems or tree trunks, and rots (Figure16) of any part of the plant, usually roots or tubers. Wilts can also occur, due to plugging of vascular tissue (Figure 17). Symptoms may vary with photoperiod, plant variety, temperature and humidity, and infective dose. In some cases, symptoms may disappear or become inconsequential with further growth of the plant. For example, Holcus spot of corn caused by Pseudomonas syringae pv. syringaeis arrested at the onset of hot dr...

    Diagnosis of non-fastidious bacterial diseases depends on characteristic symptomatology, isolation of the presumed infectious agent, and physiological and/or molecular tests (Plant Disease Diagnosis). In heavily infected plants, bacterial populations in leaves or lesions may reach 108 or 109 CFU/gram of plant tissue, and actually visibly ooze from leaves or stems (Figure 18). A simple way to determine if a disease is caused by a bacterium is to cut a typical lesion or discolored area near its boundary with healthy tissue and suspend it in a droplet of water on a microscope slide. If a mass of moving small rods or 'dots' is seen at 400-1000x magnification flowing from the cut tissue under a microscope, you are observing bacterial streaming (Figure 19) which is an indicator of a bacterial disease. However, not all bacterial infections show streaming, or it may not be visualized without special microscope attachments. Serological tests, usually enzyme-linked, and physiological assays a...

    Bacterial diseases, in principle, can occur in any plant. Minimizing plant disease requires understanding the mechanisms of survival and spread. A competitive exclusion mechanism by beneficial bacteria can be effective in protection against disease. (Biological Control of Plant​ Pathogens). Notably, in crown gall of roses, Agrobacterium radiobacter strain K84 and its genetically engineered, transfer-minus derivative, strain K1026, provide excellent protection against A. tumefaciens(Ryder and Jones, 1991). Experimentally, and to a limited extent commercially, specific bacteriophages have been used as biological control agents and have merit based on having highly benign environmental effects. In some cases, copper-based sprays are effective at minimizing inoculum build-up. But copper-resistant bacteria have also arisen. In a few cases, antibiotics used occasionally in human medicine have been used for combating plant diseases (Antibiotic Use for Plant Disease Management in the U.S.)....

  11. Gram-Positive Bacteria Overview, Interpreting Test Results

    Dec 18, 2019 · If a bacterium is pathogenic, it means it causes disease in humans. Many gram-positive bacteria are pathogens.. While there are more than 100 pathogenic gram-positive bacteria, the most notable ...

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