Bio 205 Workshop 2 Bacteria Purpose of Bergy’s Manual: based on ribosomal RNA sequences, which presumably reflect phylogenetic (evolutionary) relationships. Used for the identification of prokaryotes. 2nd edition on classification of prokaryotes. 4 Tests/ Parameters that are evaluated to classify bacteria are: procedure’s that determine an organism’s ability to ferment carious carbohydrates; utilize various substrates such as specific amino acids, starch, citrate, and gelatin; or produce waste products such as hydrogen sulfide gas and also differences in fatty acid composition of bacteria are also used to distinguish between bacteria. Divisions of procaryotic bacteria per Bergy’s Manual are: Gracillicutes, Firmicutes, Tenericutes, and Mendosciutes What kingdoms are procaryotic organisms classified? Monera and What domains are procaryotic organisms classified? Archae and Bacteria Description of the following including, Gram stain, Morphology, and Genus species of common representative organisms & significant characteristics organisms & examples Enterobacteriaceae (enterics) -Gram neg. , rod shaped fermenting sugars to produce lactic acid. Ex: Salmonella, E. coli, Shigella Micrococcaceae- Gram pos. cocci (round), Streptococcaceae- Gram pos. , Ex: Streptococcus, Lactococcus, Lactovum Mycoplasmataceae- Gram neg. , nonmotile microorganism, Mycobacteriaceae- Gram pos. , aerobic and nonmotile, genus of Actinobacteria. Ex: Tuberculosis Rickettsiaceae- Gram neg. , sensitive to environmental exposure. Genus-Rickettsia. Ex: Ticks, Lice Chlamydiaceae- Gram neg. , Phylum Chlamydiae, Ex: Chlamydia, C. trachoma is, C. suis 7. A 27 year old white female presented at the walking clinic of her local physic al on August 15. On physical exam, the patient had a fever of 38. 5C.
She appeared fatigued, had tender joints, and complained of a headache, a stiff neck and a backache. The physician noticed a circular “rash” about 5 inches in diameter, with a bright red leading edge and a dim center in the form of a “bull’s eye”. The physician noted an irregular heart beat. The patient complained of lack of ability to concentrate. The patient gave the following history: She is a graduate student in the wildlife program at the university in town. She was in the field for 3 weeks in Wisconsin during the months of May and June. She tracks small mammals in the field and studies their behavior.
It had been a warm, wet spring and the complained of a large number of biting flies, mosquitoes and ticks in the area. She felt well until about 2 weeks after returning to her home. Since that time, many of her symptoms had progressed. She finally found that she could take it no more. a. What is your best diagnosis of this case? b. What is the etiology, or the genus species name of the causative organism? c. What features are critical to your diagnosis? d. What further steps should be taken to clear up the problem? e. What preventative actions could have been taken? 8.
Louis Pasteur said, “The role of the infinitely small in nature is infinitely large. ” Explain what he meant by using samples of the roles of microorganisms in health, industry, and the environment. -I think he meant that we need microorganisms in our health because they help our digestive system and we use them in agriculture to make products like, cheese, breads, yogurt, etc. We use them to clean our house and our hands. Medicine such as Penicillin is made from microorganisms which help us when we are sick. Fungi and Algae 1. What kingdom are molds and yeasts classified? Fungi -eucaryotic What domain?
Eucaryotes 2. Know defining characteristics of Fungi. Have cell walls which are strong, flexible, nitrogenous polysaccharide called chitin. Lack chlorophyll-do not form photosynthesis. 3. Know the nutritional adaptations of fungi. In nature, they decompose dead organisms (esp. plants) and recycle their nutrients. Fungi are heterotrophs where they obtain their nutrients by absorption. Saprobes, in which fungi secret enzymes to break down dead organic matter in recycling. Other fungi are parasitic and obtain their nutrients from living hosts. 4. Know the classification of fungal diseases (mycoses). 0% of known fungal species produce mycoses, which are fungal diseases of plants, animals, and humans. Classifications of fungi are; Zygomycota, Ascomycota, and Basidiomycota. 5. Know economic effects of fungi. Fungi produce gallic acid, which is used in photographic developers, dyes, indelible ink, as well as in the production of artificial flavoring, perfumes, chlorine, alcohols, and several acids. Fungi are also used to make plastics, toothpaste, soap, and in the silvering of mirrors. In Japan almost 500,000 metric tons of fungus-fermented soybean curd (tofu and miso) are consumed annually.
Different strains of the rust fungus Puccinia graminis cause billions of dollars of damage annually to food and timber crops throughout the world. 6. What kingdom are algae classified? The classification of algae is not yet settled, however, there are different divisions of kingdoms. Chlorophyta (Green Algae), Kingdom Rhodophyta (Red Algae), Halophyte (Brown Algae), Chrysophyta (Golden Algae, Yellow-Green Algae, and Diatoms) What domain? Eucaryotes-eucaryotic photosynthesizers (plants) Algae are classified by their photosynthetic absorption spectra. 7. Know defining characteristics of algae. quatic, photosynthetic (i. e. , chloroplast-containing), Algae can be multicellular or unicellular. 8. Know economic effects of algae. Some harmful algae produce potent toxins which cause illness or death in humans and other organisms, including endangered species. Other harmful algae are non-toxic to humans and wildlife but degrade ecosystems by forming such large blooms that they can adversely affect corals, seagrasses, and organisms living on the sea-bottom. 9. A California farmer developed a low-grade fever, myalgia, and cough. A chest X ray revealed an infiltrate in the lungs.
Microscopic examination of the sputum revealed found, budding cells. A sputum culture grew mycelia and arthroconidia. a. What is the scientific name of the organism most likely the cause of the symptoms? Ascomycota- the Ascomycetes. Valley Fever. (coccidioidomycosis). b. What type of a microbiological agent is responsible for this disease? Fungi c. How is this disease transmitted? It is inhaled. d. How might it be prevented? Ovoid construction sites and dusty areas. Stay indoors. 10. Seventeen patients in ten hospitals had cutaneous infections caused by Rhizopus.
In all 17 patients, Elastoplast bandages were placed over sterile gauze pads to cover wounds. Fourteen of the patients had surgical wounds, two had venous line insertion sites, and one had a bite wound. Lesions present when the bandages were removed ranged from vesiculopustular eruptions to ulcerations and skin necrosis requiring debridement. a. How did the wounds most likely get contaminated? The surgeons used dirty bandages. b. Why is a fungus a more likely contaminant than a bacterium in this instance? The fungi most likely spread and used the humans as a host. 11.
Why doesn’t penicillin act against any of the pathogenic fungi or algae? Penicillin wouldn’t work so well, because it doesn’t work on gram-positive bacteria. Protozoa and Helminths 1. What kingdom are protozoa classified? Protista. What domain? Eucaryotes. 2. Know defining characteristics of protozoa. single celled, non-algae, non-fungal. They feed on organic matter and other microorganisms through phagocytosis. There are also protozoans that produce their own food (autotrophs) through the process of photosynthesis. They reproduce via binary fission or multiple fission. 3. Know the ecological roles of protozoa.
Most important role is in the food chain. Protozoa is what fish rely on as their major source of protein. Protozoa helps control the population of bacteria as well as other protozoa’s feeding on them. Decomposition so that nutrients and minerals are recycled back to the environment. 4. What kingdom are helminths classified? Animalia What domain? Eucaryotes 5. Know defining characteristics of helminths. All helminthes are relatively large, well-developed organ systems, most are active feeders, body is either flat and covered with plasma membrane, or cylindrical and covered with cuticle.
Some helminthes are hermaphrodites, and others have separate sexes. 6. Differentiate between an intermediate host and a definitive host. A primary host or definitive host is a host in which the parasite reaches maturity and, if applicable, reproduces sexually. A secondary host or intermediate host is a host that harbors the parasite only for a short transition period, during which (usually) some developmental stage is completed. Example: In the case of malaria, the definitive host is the mosquito and the intermediate host is the human. 7. What is the role of arthropods in the field of microbiology?
They are biological vectors, meaning they also serve as hosts for the pathogens they transmit. 8. A 62-year old diabetic black man presents in the emergency room with a swollen left leg with areas of blanching and blue mottling. A “foul order” is coming from a dressed wound. The physician removed the dressing and a brownish fluid is seeping from a wounded area. The fluid contains what appears to be small bits of tissue. No pus appears to be present. The wound has a strong” rotten” odor. Five days earlier, while at his work as a farmer, he caught the leg in his manure spreader, sustaining a deep, crushing, grossly dirty injury.
His wife cleaned the wound as well as she could with soap and water, dressed in with clean gauze, and wrapped it tightly with an elastic bandage to stop the bleeding. The second day they redressed the wound and applied tripe antibiotic ointment. The patient treated his pain with ibuprofen (Advil). He reported the pain was not bad for the first 72 hours. In the past 24 hours, the leg swelled and the mottling began to appear. A foul odor and severe pain accompanied the swelling. His wife convinced him to come to the emergency room even though they did not have medical insurance. (Hint: this is a bacterial infection. a. What is your diagnosis in this case? Gangrene b. What is the etiology? Or what is the scientific name of the organism responsible? A beta-hemolytic Streptococcus species. c. How should this wound be treated? Dead tissue should be removed immediately (amputation). An operation to improve blood supply, antibiotics, repeated operations to remove dead skin. d. Is this a life-threatening condition? No, complications could include disability, prolonged wound healing, or the need for reconstructive surgery. e. Is it likely that the patient’s diabetes contributed to the problem as presented?
Yes. 9. How are cysts of protozoa similar to bacterial endospores? Both can survive harsh conditions. How are they different? Protozoa feed on bacteria and other smaller organisms, whereas bacteria feed on dead animal and plant materials, making them decay. 10. Why are macroscopic tapeworms studied in the field of microbiology? I would assume because they are a part of nature, and their eggs are microscopic. The Un-Living 1. Differentiate between a virus and a bacterium. A virus is an organism that contains no cells (acellular) whose genome consists of nucleic acid and hat reproduce inside host cells. They do not breathe, move or grow. However, they most definitely reproduce and can adapt to new hosts. A bacterium is any of the one-celled (unicellular) prokaryotic micro-organisms of the class Schizomycetes. Capability to move (motility). They may be free-living, saprophytic (obtaining food by absorbing dissolved organic material), or capable of causing disease (pathogenic) in plants or animals. 2. Describe the major parts and shapes of viruses. Helical: rod-shapedshort and highly rigid, or long and very flexible. Icosahedral: near spherical 12 minimum.
Prolate: five-fold axis, structure is cylinder with a cap at the other end. And Complex: neither purely helical or icosahedra, extra protein tails on outer wall. 3. What does it mean that some are naked and some are enveloped? What is the composition of the envelop? When a virus lacks an envelope it is called a naked virus. Made of cell wall, cytoplasm membrane (gram-pos &neg. ) and an outer membrane (gram-neg). 4. How do viruses multiply in the host cell? A virus injects its DNA into the host cell making it produce multiple copies of that DNA and multiple copes of the protein capsule of that virus.
When the host becomes full of many copies of that virus, the host cell explodes releasing all the new viruses. This is done by either lytic cycle or lysogenic cycle. 5. What does it mean that a virus is an obligate parasite? They can’t reproduce outside of a host cell; viral DNA always inserts itself into host DNA; the invariably kill any cell they infect; they can incorporate nucleic acids from other viruses; and they must use the enqumes encoded by the virus itself. 6. What is a bacteriophage? A virus that infects and usually destroys bacterial cells. . How does a virus cause damage to the host? Viruses damage the host by consuming their substance -- eating the host from the inside out. The digestion of the host by the infectious agent can cause death to the host body. Some viruses produce toxins that poison the host. Some viruses cause hosts to grow tumors, such as cancers. All of the immediate damage to the host is by an infectious agent that damages a particular organ or tissue. 8. Why don’t we grow viruses in our lab? Because there could be an accident and someone could get sick or hurt. 9.
Differentiate between persistent viral infections and chronic latent viral infections and know examples of diseases. Persistent infections are characterized as those in which the virus is not cleared but remains in specific cells of infected individuals. Persistent infections may involve stages of both silent and productive infection without rapidly killing or even producing excessive damage of the host cells. Examples of persistent infections are subacute sclerosing panencephalitis (SSPE) that can follow an acute measles infection and progressive encephalitis that can follow rubella.
Unlike latent and chronic infections, slow infection may not begin with an acute period of viral multiplication. In a latent viral infection the virus remains in equilibrium with the host for long periods of time before symptoms again appear, but the actual viruses cannot be detected until reactivation of the disease occurs. Examples include infections caused by HSV-1 (fever blisters), HSV-2 (genital herpes), and VZV (chickenpox-shingles). 10. Differentiate between virus, viroid, and prion. A virus is an infectious acellular agent with nucleic acid surrounded by pertinacious capsomeres.
A viroid is an infectious entity affecting plants, its smaller than a virus and it consists of only one strand of RNA. A prion is a pertinacious infectious particle hat lacks nucleic acids and replicates by converting similar normal proteins into new prions. 11. Compare and contrast lysogeny by a prophage and latency by a provirus. The lysogeny infects hosts cells grow and reproduce normally for generations before they lyse. A prophage is an inactive bacteriophage which is inserted into a host’s chromosome. A virus in latency has the ability to lie dormant within a cell. Anti-Infective Drugs 1.
Define the following terms: Chemotherapy: a branch of medical microbiology in which chemicals are studied for their potential to destroy pathogenic microorganisms. Antimicrobial drugs: any compound used to treat infectious disease, may also functions as intermediate level disinfectant. Antibiotic: antimicrobial agent that is produced naturally by an organism. Selective toxicity: principle by which an effective antimicrobial agent must be more toxic to a pathogen than to the pathogen‘s host. Prophylaxis: measures designed to preserve health (as an individual or of society) and prevent the spread of disease. . What are the characteristics of the ideal antimicrobial drug? Selectively toxic to the microbe but non toxic to host cells Microbicidal rather than microbiostatic Relatively soluble and functions even when highly diluted in body fluids Remains potent long enough to act and is not broken down or excreted prematurely Not subject to the development of antimicrobial resistance Complements of assists the activities of the host's defenses Remains active in tissues and body fluids Readily delivered to the site of infection Not excessive in cost
Does not disrupt the host's health by causing allergies or predisposing the host to other infections Quinine Inhibition of cell wall synthesis Inhibition of nucleic acid synthesis, structure or function Inhibition of protein synthesis Disruption of cell membrane structure or function Mechanisms of Drug Action can be a. Inhibition of cell wall synthesis b. Inhibition of nucleic acid (RNA and DNA) structures and function c. Inhibition of protein synthesis d. Interference with cell membrane structure or function e. Inhibition of folic acid synthesis 3.
Briefly describe these mechanisms in your own words, and list the types of medications capable of the mechanisms. Antibiotics that inhibit cell wall synthesis such as penicillin grow under normal circumstances is impossible in the absence of peptidoglycan synthesis. 4. Explain the following: Antibacterial: an antibacterial is a compound or substance that kills or slows down the growth of bacteria. Antifungal: An antifungal capable of destroying fungi. Antiparasitic chemotherapy: destructive to parasites. Antiprotozoal: a medical drug used to fight diseases (malaria) caused by protozoas.
Antihelminthic: medicine used to destroy parasitic worms. Antiviral: drug or treatment used to fight against viruses. 5. Are medications used against helminthes effective for bacterial infections? I would say, yes they can help the bacterial infection because a virus will be stopped from copying itself and the bacteria will soon stop 6. How are synthetic antibacterial drugs different from antibiotics? Antibacterial drugs and antibiotics are one and the same. Synthetic means it's created through chemical reactions instead of organisms. 7. Briefly explain how antiviral agents work.
They work by slowing down the virus from replicating itself. Drugs usually work by interacting with receptors on the surface of cells or enzymes within cells. 8. How does drug resistance develop? When a drug is given and only kills a certain amount of the bacteria, because some might have been a mutation of that bacteria then the bacteria that wasn’t killed is replicated and then that person has a new bacteria in them that is resistant to the drug given. 9. What are some new approaches to antimicrobial therapy? 10. What is susceptibility testing? Susceptibility testing is to predict the in vivo success or failure of antibiotic therapy.
What is the name of the lab? Antibiotic Sensitivity Testing Using The Kirby-Bauer Method. A pathogen is isolated and then identified. Then its tested for sensitivity to a number of antimicrobial agents to help the clinician pick what’s best for the patient. 11. Your pregnant neighbor has a sore throat and tells you that she is taking some tetracycline she had left over from a previous infection. Give 2 reasons why her decision is a poor one. Tetracycline can harm the fetus. When tetracycline is used during pregnancy it can cause the teeth to become permanently stained.