Reviewer Micropara 1 PDF

What is a Bacteria? streptomycin and tetracycline, which are A single celled microscopic organism that critical for treating bacterial infections. exist in various environment – from soil, water and to human bodies. One of the oldest l...

What is a Bacteria? streptomycin and tetracycline, which are A single celled microscopic organism that critical for treating bacterial infections. exist in various environment – from soil, water and to human bodies. One of the oldest life forms on B) Biotechnology Earth that plays an important role in sustaining Genetically engineered bacteria are used ecosystems, health and even industry. to produce insulin, hormones, and vaccines, making them essential tools in modern medicine. Importance and Contribution of Bacteria 6. INDUSTRIAL APPLICATIONS 1. HUMAN HEALTH AND MICROBIOME A) Waste Treatment A) Digestive Health In sewage treatment plants, bacteria Bacteria like “Lactobacillus” and break down organic waste, helping purify water “Bifidobacterium” help break down food in the gut, before it is returned to natural sources. aiding digestion and producing vitamins like B12 and K. They also prevent the growth of harmful B) Biodegradable Plastics and Biofuels microbes, supporting immune function. Certain bacteria produce biodegradable plastics and biofuels, contributing to B) Immune System Development sustainable alternatives for plastic and fossil Early exposure to beneficial bacteria trains fuels. the immune system to recognize harmful pathogens. Bacteria are crucial to the functioning of A balanced microbiome helps regulate inflammation natural ecosystems, human health, and and reduces the risk of autoimmune diseases. various industries. Their contributions support environmental health, agricultural 2. AGRICULTURE AND SOIL FERTILITY productivity, food safety, medicine, and sustainable practices, making them an A) Nitrogen Fixation essential part of life on Earth. Bacteria like *Rhizobium* convert nitrogen from the air into a form that plants can use, enriching the soil and promoting plant growth. This natural Differences Among Bacteria fertilization reduces the need for chemical fertilizers, supporting sustainable agriculture. Bacteria vary widely based on their shapes, environments, and roles. Some are B) Decomposition beneficial, while others are harmful. They can Soil bacteria break down organic matter, differ in their response to oxygen, their ability returning essential nutrients like nitrogen, to form spores for survival, and their phosphorus, and carbon to the soil, which supports interactions with other organisms, either as plant health and ecosystem balance. symbionts, commensals, or pathogens. Additionally, genetic differences among 3. FOOD PRODUCTION AND PRESERVATION bacteria make some resistant to antibiotics, allowing them to survive even under antibiotic A) Fermentation treatment. Lactic acid bacteria are used in making fermented foods such as yogurt, cheese, and 1. SHAPE AND MORPHOLOGY pickles. These bacteria not only add flavor but Bacterial shapes influence where also extend shelf life and add probiotics, which bacteria can thrive and how they function. benefit gut health. Here’s an overview of common bacterial shapes, their typical habitats, and how these shapes B) Food Safety contribute to their functions: Certain bacteria produce natural antibiotics and acidic by-products that prevent A) Cocci (Spherical) harmful microbes from growing in foods, enhancing safety. Bacteria that are round or spherical in shaped. Common examples of this bacteria 4. ENVIRONMENTAL CLEAN UP were Streptococcus and Staphylococcus. (BIOREMEDIATION) Usually found on human skin, mucous Some bacteria can break down membranes, and other body surfaces; also pollutants (Pollution Reduction), such as oil, common in water, soil, and food. The spherical pesticides, and heavy metals, in soil and water. shape provides a large surface area relative to For instance, “Alcanivorax” bacteria consume volume, allowing cocci to absorb nutrients oil, which makes them useful in cleaning up oil efficiently in nutrient-rich environments, like spills, restoring ecosystems, and reducing the human body. Cocci often form clusters environmental damage. (e.g., Staphylococcus) or chains (e.g., Streptococcus), which can enhance their ability 5. MEDICAL AND PHARMACEUTICAL to cause infections by spreading across tissues or resisting immune responses. A) Antibiotic Production Bacteria like *Streptomyces* produce a) Staphylococcus aureus - Often found in naturally occurring antibiotics, such as clusters like grapes, responsible for skin infections. b) Streptococcus pneumoniae - Forms chains E) Filamentous (Thread-like) and is a common cause of pneumonia. Bacteria that are have a long, thread-like c) Neisseria gonorrhoeae – (Diplococci) They filaments in shape. Common example was occur in pairs, and cause the sexually Streptomyces where primarily found in soil. The transmitted infection gonorrhea. filamentous structure allows these bacteria to form networks in the soil, aiding in the B) Bacilli (Rod-shaped) breakdown of organic material and the Bacteria that are rod-like or cylindrical production of natural antibiotics. Streptomyces in shaped. Common example was Escherichia species, for example, produce compounds that coli, and Bacillus subtilis. Commonly found in inhibit other microorganisms, which helps the intestines of animals, soil, water, and them compete in soil environments and has decaying organic material. The rod shape significant applications in antibiotic allows bacilli to move efficiently in liquid production. environments, facilitating nutrient absorption and colonization in places like the intestines. a) Nicordia Species – found in soil and water Bacilli can form endospores, a survival and can decompose organic matter but can mechanism in harsh environments, such as cause infection in humans (nicordiosis) which dry soil or areas with high UV exposure. affect the lungs, skin and brain. b) Actinomyces israelli – can cause a) Escherichia coli - A common bacterium actinomycosis, a rare but chronic infection that found in the gut, some strains can cause food forms abscesses in the mouth, lungs, and poisoning. gastrointestinal tract when the bacteria enter b) Bacillus anthracis - Causes anthrax and deeper tissues through injuries. can form spores that survive in harsh conditions. Bacterial shape is closely tied to habitat c) Salmonella typhi - Causes typhoid fever. and function, influencing how bacteria acquire nutrients, move, and survive in diverse C) Spirilla (Spiral-shaped) and Spirochetes environments. This adaptability allows them to (Corkscrew-shaped) inhabit virtually every ecosystem on Earth, Bacteria that are Spiral or corkscrew in from deep-sea vents to the human gut. shaped. Common examples were Helicobacter pylori and Borrelia burgdorferi. Common in viscous environments, such as mucous layers in the stomach or connective tissues in animals. Their spiral shape enables them to move through thick, viscous environments. For instance, Helicobacter pylori uses its shape to burrow through the stomach lining. The spiral structure helps some bacteria, like Borrelia (causing Lyme disease), evade the immune system by “twisting” through tissues and avoiding detection. a) Helicobacter pylori - A spiral bacterium that infects the stomach lining, causing ulcers. b) Spirillum minus - Known to cause rat-bite fever. c) Treponema pallidum - The bacterium responsible for syphilis. d) Borrelia burgdorferi - Causes Lyme disease, transmitted through tick bites. D) Vibrios (Comma-shaped) Bacteria that are Curved rod in shape resembling a comma. Common example was Vibrio cholera (causes cholera). Common in aquatic environments, particularly brackish or saltwater. The curved shape aids in mobility, allowing vibrios to move efficiently in water, 2. GRAM STAINING (CELL WALL which is essential for survival in aquatic STRUCTURE) habitats. Vibrios often thrive in nutrient-rich water where they can quickly reproduce and Bacteria are classified as Gram-positive or release toxins, as in the case of Vibrio cholerae Gram-negative based on their cell wall during cholera outbreaks. structure, which can be observed using the Gram stain technique: a) Vibrio cholera - Causes cholera, a severe diarrheal disease often linked to contaminated Gram-positive Bacteria water. Bacteria that have thick peptidoglycan b) Vibrio vulnificus - Found in warm seawater layers in their cell walls, which retain the and can cause severe infections in wounds or crystal violet dye and appear purple. when ingested. “Staphylococcus” and “Streptococcus” are common Gram-positive bacteria. Gram-negative Bacteria Bacteria that obtain nutrients by Bacteria that have a thin peptidoglycan breaking down organic materials. Most layer surrounded by an outer membrane, pathogenic bacteria, like Streptococcus and which doesn’t retain the dye well and appears Salmonella, are heterotrophic. pink or red after counterstaining. Escherichia coli and Salmonella are Gram-negative Chemotrophic Bacteria bacteria. Bacteria that derive energy from chemical reactions rather than light. Some This distinction is crucial as it chemotrophs, like sulfur bacteria, are found in influences antibiotic treatment options, with extreme environments, such as hot springs and Gram-negative bacteria often being more hydrothermal vents. resistant to antibiotics due to their outer membrane. 6. PATHOGENICITY (ABILITY TO CAUSE DISEASE) 3. OXYGEN REQUIREMENT Not all bacteria are harmful. Bacteria can be: Bacteria vary in their need for oxygen: Pathogenic (Disease-Causing) Aerobic Bacteria These bacteria produce toxins or invade Bacteria that require oxygen for growth body tissues, causing diseases like pneumonia and survival. Mycobacterium tuberculosis, the (Streptococcus pneumoniae) or food poisoning cause of tuberculosis, is an aerobic bacterium. (Salmonella). Anaerobic Bacteria Opportunistic Pathogens Bacteria that grow in the absence of Normally harmless, these bacteria cause oxygen and can be found in environments like infections when the immune system is deep soil or human intestines. Examples weakened. Pseudomonas aeruginosa, for include Clostridium botulinum, which can example, can infect those with compromised cause botulism. immunity. Facultative Anaerobes Non-pathogenic or Beneficial Bacteria that can survive with or without These bacteria are harmless or oxygen, adapting their metabolism accordingly. beneficial, aiding digestion (e.g., Lactobacillus E. coli is a facultative anaerobe. in the gut) or decomposing organic matter in the soil. Microaerophilic bacteria Bacteria that need low levels of oxygen, 7. ANTIBIOTIC RESISTANCE less than what is found in the atmosphere, for Some bacteria are inherently resistant to optimal growth. Helicobacter pylori is an certain antibiotics, while others have developed example. resistance due to mutations or gene transfer: 4. SPORE FORMATION Antibiotic-Resistant Strains Bacteria that can survive even when Some bacteria can form endospores, exposed to antibiotics. Methicillin-resistant which are tough, dormant structures that help Staphylococcus aureus (MRSA) is an example. them survive harsh conditions: Non-Resistant Bacteria Spore-forming bacteria like Bacillus Bacteria that are generally susceptible and Clostridium, can withstand extreme to antibiotics, which kill or inhibit their growth. temperatures, radiation, desiccation, and chemicals. Antibiotic resistance is a growing public health concern as it limits treatment options Non-spore-forming bacteria lack this and increases the risk of severe infections. ability and are more susceptible to environmental stress. 8. GENETIC COMPOSITION AND GENE TRANSFER Spore-forming bacteria pose challenges Bacteria have highly adaptable genomes in healthcare and food safety because they can and can transfer genes among each other survive disinfection processes and later cause through processes like conjugation, infections. transformation, or transduction: 5. NUTRITIONAL NEEDS AND METABOLISM Horizontal Gene Transfer Bacteria have different nutritional needs and The movement of genetic material metabolic pathways: between organism in a ways other than the traditional parent to offspring (vertical Autotrophic Bacteria transfer). HGT is a crucial mechanism that Bacteria that produce their own food. allows bacteria to quickly acquire new traits, Some, like cyanobacteria, are photosynthetic such as antibiotic resistance. HGT also and use sunlight to create energy. facilitate the genetic diversity among bacteria. This varies widely among bacteria, making Heterotrophic Bacteria some species more adaptable to new environments or treatment measures.  Beneficial Bacteria in Various Aspect There are three primary mechanisms of horizontal gene transfer in bacteria: 1. GUT HEALTH AND DIGESTION a. Transformation Bacteria such as Lactobacillus Bacteria take up free DNA from the acidophilus and Bifidobacterium species are environment, which may integrate into their good bacteria that resides to our gut. These genome if compatible. For example, a bacteria are key probiotics found in the human bacterium could acquire genes for antibiotic gut and in fermented foods like yogurt and resistance from DNA released other, lysed cell kefir. They aid digestion by breaking down (cell that broken down and died due to damage complex carbohydrates and fibers, producing to its plasma membrane) short-chain fatty acids and vitamins like B12 and K. They also help balance gut flora by b. Conjugation inhibiting harmful bacteria and promoting a A process of direct transfer of DNA through healthy immune response, reducing the risk of cell-to-cell contact. Often, plasmid – small, digestive disorders like irritable bowel circular DNA molecules – are exchanged, syndrome (IBS) and inflammatory bowel transferring genes for traits such as toxin diseases. production or antibiotic resistance. 2. SOIL FERTILITY AND AGRICULTURE c. Transduction Rhizobium and Azospirillum are Bacteriophages (viruses that infect bacteria) bacteria that good for maintain the soil fertility mediate thus type of gene transfer. When and nutrients need for agriculture. These bacteriophage mistakenly incorporates nitrogen-fixing bacteria live in a symbiotic bacterial DNA into viral particle, it can transfer relationship with legume plants. They convert that DNA to another bacterial cell during atmospheric nitrogen into ammonia, a form subsequent infections. plants can absorb and use for growth. By enriching the soil with nitrogen, these bacteria Horizontal Gene Transfer has a reduce the need for chemical fertilizers, substantial implication in medicine, promoting sustainable agriculture and agriculture and Biotechnology, as it plays a improving crop yields naturally. major role in the spread of antibiotic resistance and other survival traits among bacterial 3. ENVIRONMENTAL CLEANUP populations. (BIOREMEDIATION) Bacteria such as Pseudomonas putida 9. ENVIRONMENTAL HABITATS and Alcanivorax borkumensis are examples of Bacteria can thrive in a wide range of bacteria that are responsible in the process of environments, including extreme ones: bioremediation. Certain bacteria can break down environmental pollutants, such as oil Mesophiles spills, heavy metals, and industrial waste. Bacteria that thrive in moderate *Alcanivorax borkumensis*, for instance, is conditions (like human body temperature). used in cleaning up oil spills because it can degrade hydrocarbons in oil. This process, Thermophiles called bioremediation, reduces the Bacteria that live in hot environments, environmental impact of pollutants and aids in such as hot springs. restoring ecosystems affected by industrial pollution. Psychrophiles Bacteria can survive in cold 4. ANTIBIOTIC PRODUCTION temperatures, like in glaciers or deep-sea Streptomyces species bacteria produce environments. naturally occurring antibiotics, including streptomycin, tetracycline, and erythromycin. Halophiles These antibiotics have been vital in treating Bacteria thrive in highly salty bacterial infections, saving countless lives and environments, such as salt lakes. revolutionizing medicine. Many antibiotics used today are derived from bacteria, Bacteria’s adaptability to different showcasing their importance in developing conditions allows them to populate nearly every treatments for diseases. environment on Earth, from soil and water to extreme habitats. 5. FOOD PRODUCTION AND PRESERVATION In the food industry, lactic acid bacteria These differences make bacteria highly play a crucial role in producing and preserving adaptable and versatile organisms with diverse fermented foods like yogurt, cheese, roles. Some bacteria are vital for health, sauerkraut, and pickles. These bacteria not industry, and the environment, while others only enhance flavor but also inhibit spoilage- can cause diseases and resist treatments. causing bacteria by producing lactic acid, Understanding these distinctions helps in which lowers the pH and creates an managing bacterial risks, leveraging their inhospitable environment for harmful beneficial uses, and developing targeted microbes. This fermentation process extends medical treatments. shelf life and adds beneficial probiotics to the diet. Lactobacillus and Leuconostoc are BENEFICAL AND HARMFUL BACTERIA examples of bacteria responsible in this process.  Given these risks, it’s essential to implement preventive practices, such as: Harmful/Risky Bacteria in Various Aspects A) Proper Food Handling 1. FOODBORNE ILLNESSES Cooking meats thoroughly, washing Salmonella and pathogenic E. coli hands and surfaces, and refrigerating strains are responsible for foodborne illnesses, perishable items promptly can prevent often resulting from undercooked meat, foodborne illnesses. contaminated produce, or unpasteurized dairy. These bacteria can cause severe B) Vaccination gastrointestinal symptoms, including vomiting, Vaccines for bacterial diseases like diarrhea, and abdominal pain. Some cases, tuberculosis and pneumonia reduce the especially those caused by E. coli O157:H7, can incidence of these infections. lead to kidney failure, particularly in vulnerable populations like young children and the C) Antibiotic Stewardship elderly. Using antibiotics responsibly and only when prescribed by a healthcare provider helps 2. TUBERCULOSIS (TB) prevent antibiotic resistance. Mycobacterium tuberculosis is a D) Hygiene and Sanitation pathogen that causes tuberculosis, a serious Regular handwashing, surface respiratory disease that primarily affects the disinfection, and safe water practices help lungs but can spread to other parts of the body. reduce bacterial spread, especially in TB is highly contagious, spreading through the healthcare and community settings. air when an infected person coughs or sneezes. Drug-resistant strains of TB have emerged, E) Personal Protective Measures making treatment more complex and Using insect repellents and checking for heightening the risk of transmission and ticks after outdoor activities can reduce the risk mortality. of Lyme disease. 3. NECROTIZING FASCIITIS (FLESH-EATING Bacteria play diverse roles in our world, DISEASE) offering invaluable benefits but also presenting Streptococcus pyogenes, known for causing risks. Beneficial bacteria contribute to human flesh-eating disease. S. pyogenes can rapidly health, agriculture, environmental cleanup, destroy muscle, fat, and skin tissue. medicine, and food production, showcasing Necrotizing fasciitis often enters through minor their versatility and importance. Conversely, cuts or injuries and can progress swiftly, pathogenic bacteria underscore the need for leading to severe tissue damage and even death preventive measures to manage risks, if not treated promptly. This infection is a especially given the rising concern over medical emergency that often requires surgery antibiotic resistance. With a balanced and aggressive antibiotic therapy. approach, we can harness bacterial benefits while mitigating their potential harms. 4. HEALTHCARE-ASSOCIATED INFECTIONS (HAIs) In healthcare settings, antibiotic- resistant bacteria like C. difficile and MRSA pose significant risks to patients. C. difficile causes severe diarrhea and colitis, often after antibiotic treatment disrupts normal gut bacteria, allowing it to proliferate. MRSA infections are challenging to treat due to resistance to multiple antibiotics and can lead to life-threatening conditions such as sepsis and pneumonia. Clostridium difficile and Methicillin-resistant Staphylococcus aureus (MRSA) are example of bacteria associated to such diseases. 5. LYME DISEASE Transmitted through tick bites, Borrelia burgdorferi causes Lyme disease, which can lead to chronic fatigue, joint pain, and neurological problems if untreated. Lyme disease cases have increased due to expanded tick habitats and climate change. This bacterial infection is particularly concerning in forested or grassy regions and requires prompt antibiotic treatment to prevent long-term complications. PREVENTIVE MEASURES FOR BACTERIAL RISKS