Taking a Look at Bacterial Endospores

The identification of bacteria is a fundamental objective of microbiologists. It is essential to distinguish specific bacterial properties to understand the environment, physiology and disease. As new bacterial species emerge and existing ones evolve into different strains, it is imperative that microbiologists continue to isolate bacteria from the field, identify their findings and research newly discovered forms. Their discoveries can then be used to evaluate the types of microbial life that may be found in certain environments and the corresponding benefits or risks to those that dwell in those areas.

The genus Streptococcus is classified as a gram positive bacteria because of the spherical or ovoid cells that often arranged in pairs and the color it turns too after undergoing the gram staining technique. Unlike the catalase positive genus Staphylococcus, Streptococcus is catalase negative (Fox). Many Streptococcus bacteria are known to be facultative anaerobes, meaning they prefer to grow in places that have no oxygen but will adjust to places that contain some oxygen (Holt, et al.). On the contrary, there are a handful of Streptococcus bacteria that are considered to be obligate anaerobes, meaning they are strictly prohibited from being around oxygen because they are unable to live. Growing this type of bacteria includes specific factors

Escherichia coli is a gram negative bacteria which is the main aerobic commensal bacteria found in the intestines of animals; it can also become pathogenic if it gets into the urinary tract ot the blood (Erb et. al., 2007). Staphylococcus aureus is a gram positive bacteria. It is the leading cause of bacterial infections in humans involving the skin, blood, and lower respiratory tract in America (De Leo et. al., 2009); Natural selection of antibiotic resistance in S. aureus has led to the emergence of increased resistance to penicillin, methicillin, and vancomycin within the human population (De Leo et. al., 2009). One important difference between gram-positive and gram-negative bacteria is the structure of their cell walls. The cell walls

vulgaris have numerous virulence factors including fimbriae, flagella, outer membrane proteins, lipopolysaccharide, and capsule. These qualities help make sure that the cell survive. Its extracytoplasmic outer membrane is a feature shared with many others gram negative bacteria. The outer membrane of gram negative bacteria serves as a defensive barrier that controls the influx and efflux of solute. This feature allows the bacteria to inhabit several different, and sometime harsh environments. Flagella help the cell move around and fimbriae aid the cell to attach or adhere to one and other or sometime to inanimate object. P. vulgaris is highly motile that it have the ability to swarming. Swarming is the ability for bacteria to move around on solid surface at high rates. Since it natural reside in the lower GI track, a compromise immune system can cause complicated urinary tract

Anthrax is endemic is areas of the world such as Africa and the Middle East, but B. anthracis can also be found sporadically in North America and Europe often associated with contaminated livestock. In the presence of oxygen, this primary pathogen also forms very hardy endospores that can survive in the right conditions for more than 50 years. This usually occurs when an infected animal dies; the animal carcass will open, exposing the bacterium to oxygen, stimulating sporulation. The spores will survive on the dead animal tissue or soil, ready to infect the next organism, human or animal. The proteinaceous coat of the spore provides protection against extreme temperatures, and chemical and enzymatic damage. Under the coat, there is a thick layer of peptidoglycan that further reduces the permeability of the spore. Bacillus anthracis has two main virulence factors encoded on two separate transduced plasmids. The pX02 plasmid encodes for the polypeptide capsule, essential for the bacterium to avoid phagocytosis. The pX01 plasmid has three components: the PA (protective antigen), LF (lethal factor), and EF (edema factor). The edema toxin (PA and EF) causes local skin edema and the lethal toxin (PA and LF), is deadly to the susceptible cells. The exotoxins secreted from the bacterium gain entry into the cell when the protective antigen attaches to a cell membrane, stimulating the cell to endocytose either the edema toxin or

I studied the expression of V. parahaemolyticus’ expression of OM protein when grown in a high and low salt condition. I hypothesized that V. parahaemolyticus would increase the expression of OM proteins in a high salt condition and lower the expression of OM proteins in a low salt condition. As shown in the results section, V. parahaemolyticus expressed more proteins when it was grown in the high salt environment, thus my hypothesis was supported. I predicted that the bacterium would build a wall of proteins around itself to help maintain it stay isotonic state. My results showed that more proteins were expressed but I do not have results to prove that those proteins were used to keep the cell osmotically happy. I was surprised that there weren’t more

Next, using proper inoculation technique, which is heating the loop with a Bunsen burner until it is red hot and cooling it in the edge of the medium agar, grab a small but barely visible amount of Bacillus Cereus and drop it into the nutrient agar slant. Heating the tube in an 80-degree Celsius water bath should kill all of the vegetative bacterial cells in the sample, but the endospores within the sample should remain since they are resistant to heat. Once the sample has cooled, these endospores will be able to germinate to form vegetative cells. After cooling the beaker with the sample with ice, using proper inoculation techniques once again, use the 13- streak technique as used in Exercise 1.4 to streak the plate, then store the plate inverted at 37-degrees Celsius. The 13-streak technique is used isolate a bacterium into a pure culture from a mixed population [12].

T6SS, Type VI Secretion System, is a specialized protein secretion system used by bacteria for survival. This system acts as a “gun” firing proteins into the target cell. It is one of 6 found in Gram negative bacteria and has been known to target eukaryotic cells, as well as competing bacteria. T6SS serves as a virulence factor towards its host while also effectively killing its competitors, responding in stress and horizontally transfering DNA. Certain systems also recognize other cells as themselves.

Summary Citation: Madigan, M.T., J.M. Martinko, K. S.Bender, D.H. Buckley, D.A.Stahl. 2014. Brock: Biology of Microorganisms. 14th edition. Benjamin Cummings, New York.

Clostridium botulinum is a Gram-positive, anaerobic, slightly curved, motile, rod-shaped bacterium that is also spore-forming producing the heat-resistant endospores. The endospores it produces are very resistant to environmental stresses including heat and high acid, it can become activated in anaerobic environments, low acidity, high moisture content, and in temperatures ranging from 3°C to 43°C. It is usually found in soil and water of any region in the world. The production of botulinum toxin of this bacteria makes it pathogenic. It is a neurotoxin that causes the disease botulism, a rare but serious paralytic illness that can lead to death (Schneider et al. 2014).

There was no difference between the control plates which proves that the lid on the plate serves as significant protection, potentially shielding the bacteria to the mutagenic effects the UV light. All three plates were incubated at 25 degree Celsius. The first Control plate showed lots of red and furry growth and the original pattern of swiping was observed in all the quadrants. The second control plate was also observed to have furry and pigmented red growth in all the quadrants, despite being exposed to UV light due to the plate lid during exposure. The experiment plate showed the most interesting results, in the 10 second UV exposure quadrant the bacteria had red pigmented growth but it is speckled, pinpointed and the original swipes were not observed. Moreover the growth seemed not as furry and robust as the control plates. The quadrant exposed to 20 sec of UV light showed significantly less growth than the 10 sec quadrant and the colonies are pinpointed with several beige colonies in between the red speckles. Original swipe pattern of the bacteria was not observed in this colony. In the quadrant exposed to 30 seconds of UV light, the differences are even more significant as the colonies are few and far in between and only several pinpoint red colonies found with a few beige colonies and some colonies with red centers surrounded by beige. The effects of UV light are very drastic in the 40 second quadrant as the growth is severely diminished with only a

Oocyst of C. cayetanensis is spherical, 8-10 µm in diameter and appears as a nonrefrctile sphere that contains a cluster of refractive membrane bound globules (Bern et al., 1996). On sporulation the entire globule divides into two ovoid structures which are called sporocysts, each one contains two sporozoites and each sporozoite measures 1.2-9.0 microns (Ortega et al., 1993). The amount of time required for oocyst to sporulate in nature is unknown but under laboratory conditions, sporulation occurs after 5-11 days incubation in either distilled water or 2.5% potassium dichromate at temperatures of 25 to 32° C (Ortega et al., 1993; Ortega and Sanchez 2010). Laboratory diagnosis of cyclosporiosis by microscopy is the commonest method but molecular has the potential to be more sensitive in spite of being unable to differentiate live from dead Cyclospora oocysts (Garcia-Lopez et al., 1996). Due to the several outbreaks caused by cyclosporiosis and its relation to certain local or imported food and contaminated water supply the development of new anti-protozoal agents to eradicate the resistance infective forms are urgent (Chacin-Bonilla,

Bacillus subtilis is rod-shaped and has the ability to form a tough, protective endospore, allow the organism to tolerate extreme conditions. Some uses of Bacillus subtilis includes using as a model organism for laboratory studies. It can also be genetically modified to convert explosives into harmless compound of nitrogen, water and carbon dioxide. (Wikipedia, 2010)

Spirochaetes are helical bodies that can twist and screw their way through the medium but no physical external organelles (Macnab, R. 1984). Spirochetes are flagellated called axials or periplasmic fibrils found at the poles of the bacterium. Axial fibrils are composed of rotatable endoflagellum that is affixed to the rigid protoplasmic cylinder all within a tensile outer sheath. The mechanism of movement is described by Berg, H. C. (1976). the flagella produces torque between the cell and its outer membrane thus results in reciprocal rotation. Therefore, the result is a conformational change. Spirochetes can model a set of three diverse set of actions including reversais, flexing and swimming (Charon, N., et al, 1992). These can be altered through the concentration of surrounding attractant and

The SPI-2 type III secretion system is a multifunctional virulence system (Fig. 4) that is initiated following entry of bacteria into eukaryotic cells and facilitates bacterial growth in all cell types (Ochman et al.,1996;