Among the extensive cortège of plant-associated microorganisms (the so-called plant microbiota), mutualistic fungal and bacterial symbionts are striking examples of soil microorganisms that have successfully coevolved with their hosts since plants adapted to terrestrial ecosystems. They promote plant growth by facilitating the acquisition of scarce nutrients. In these…
Any part of the human body that is open to the outside world it available for the colonisation of bacteria. While this blog has covered bacteria in the and the throat, one area I ve neglected to cover is the bacteria that get into the lungs. As the company I currently work for is involved in respiratory research I was rather excited to find a PLoS One paper that looked…
To search the entire book, enter a term or phrase in the form below Custom Search Bacterial Defense against Phagocytosis © Kenneth Todar, PhD Introduction Some pathogenic bacteria are inherently able to resist the bactericidal components of host tissues, usually as a function of some structural property. For example, the poly-D-glutamate capsule of Bacillus anthracis…
The prokaryotic tubulin homolog protein FtsZ assembles into the Z-ring at mid-cell to provide contractile force during bacterial cell division. Here, by tracing the status of FtsZ in living E. coli cells, we unexpectedly revealed a cytosolic organelle-like structure containing the FtsZ protein that is solely formed in non-growing/non-dividing late stationary-phase…
For bacteria, the structural integrity of its cell wall is of utmost importance for survival, and to this end, a rigid scaffold called peptidoglycan, comprised of sugar molecules and peptides, is synthesized and located outside the cytoplasmic membrane of the cell. Disruption of this peptidoglycan layer has for many years been a prime target for effective antibiotics…
Bacterial cells are fundamentally different to the cells of multicellular animals such as humans. They are far smaller, with less internal organisation and no nucleus (they have DNA but it is not packaged safely within a membrane). Because of this bacteria are almost exclusively single-celled organisms, with their own autonomy and often mobility. Of course many bacteria…
Living cells are divided into two types - prokaryotic and eukaryotic (sometimes spelled procaryotic and eucaryotic). This division is based on internal complexity. The following interactive animations provide graphic roadmaps to the organization of both of these cell types. Prokaryotic Cell Model For life all cells have basic needs. Cells have diverged in their structure…
Bacteria are mostly unicellular organisms that lack and are among the smallest living things on earth—only viruses are smaller. Multiplying rapidly under favorable conditions, bacteria can aggregate into colonies of millions or even billions of organisms within a as small as a drop of . The Dutch merchant and amateur scientist Anton van Leeuwenhoek was the first to…
The widespread housefly is a true fly and is one of the most extensively distributed animals. The Plants & Botany Edible fungi: Certain fungi are edible. About 200 species of mushrooms (e.g., Asgaricus sp), morels Economics The number found in nature is more than all other organisms put together in and a single cell can carry Site the important of having economic…
Structure: Like many other protists, the structure of Amoeba proteus is relatively simple. It is a single celled organism that appears transparent and gelatin like – with an arguably “forever” changing shape, with a nucleus and membrane bound organelles (such as food vacuoles, contractile vacuoles, golgi apparatus, mitochondria etc.). As mentionned above, Amoeba proteus…
Learning Objectives Summarize Koch’s postulates and molecular Koch’s postulates, respectively, and explain their significance and limitations Explain the concept of pathogenicity (virulence) in terms of infectious and lethal dose Distinguish between primary and opportunistic pathogens and identify specific examples of each Summarize the stages of pathogenesis Explain…
Viruses – Pages 475-483 Viruses Not living Don’t grow or develop No respiration Only reproduce within a host (can’t do it alone MUST have a host) Virus multiply through the lytic cycle where the virus attacks the host, injects it nucleic acid into the host, and then spreads or bursts from the host. Virus Structure Structure = Made up of (1) protein coat- capsid (located…
(Smithsonian.com) What s the difference between bacteria and viruses? You asked us, what s the difference between bacteria and viruses? You see, bacteria are microscopic. They live just about everywhere, including extreme environments like hot springs and radioactive waste. Now, you can wag a finger at bacteria for things like ear infections and strep throat. But…
Bacteria are the oldest and most abundant life form on Earth. These microscopic, single-celled organisms live in all environments - including in and on the human body. A study published in May 2016 in the Proceedings of the National Academy of Sciences of the U.S.A. estimated there may be as many as 1 trillion different types of bacteria. Most bacteria are harmless…
