Module 3: Microbial Relationships and Ecological Roles PDF 2023-2024

Microbial Relationships and Ecological Roles MicroPara 2023-2024 Angeles University Foundation - College of Nursing Page 0 of 7  Module 3: Microbial Relationships and Ecological Roles MODULE OVERVIEW This self-guided module is designed to help students grasp the essential...

Microbial Relationships and Ecological Roles MicroPara 2023-2024 Angeles University Foundation - College of Nursing Page 0 of 7  Module 3: Microbial Relationships and Ecological Roles MODULE OVERVIEW This self-guided module is designed to help students grasp the essential elements of microbiology and parasitology, with a particular emphasis on microbial ecology. Microbial ecology examines the complex interactions between microorganisms and their environment. This field of study explores how microorganisms engage with their surroundings and, importantly, how they interact with humans. These interactions occur in various ways and at multiple levels, with the most intimate being the presence of microorganisms on and within our bodies. The study of microbial ecology also involves understanding the role of microorganisms in natural processes, such as nutrient cycling and energy flow, as well as their impact on ecosystems and human health. By delving into these topics, students can appreciate the significance of microorganisms in both natural and artificial environments. In addition to exploring the interactions between microorganisms and their environments, this module emphasizes the critical role of microorganisms in disease. Students will learn about the specific diseases caused by particular pathogens and how these diseases affect human health. The module covers the mechanisms by which microorganisms cause disease, the body's defenses against infections, and how microorganisms can be both harmful and beneficial to humans. By understanding these concepts, students will gain a comprehensive view of the importance of microbiology and parasitology in the broader context of health and disease. This module aims to provide students with a solid foundation in microbial ecology, preparing them for more advanced studies and practical applications in the field. MODULE LEARNING OUTCOME Upon the completion of this module, the learner should be able to: CLO1. Integrate relevant principles and concepts of anatomy and physiology of the cells in Microbiology and Parasitology CLO2. Discuss the concepts, principles, and techniques in Microbiology and Parasitology CLO3. Assess an individual's health status with microbiological or parasitic infection using appropriate techniques with a case scenario analysis through Nursing Care Plan (NCP) creation and Evidence-based Journal (EBJ) reading. LEARNING OBJECTIVES Specifically, to achieve the learning outcomes, you should have achieved the following learning tasks: A. Defined ecology and microbial ecology. B. Listed three categories of symbiotic relationships. C. Differentiated mutualism and commensalism by giving examples for each. D. Cited an example of a parasitic relationship. E. Discussed the beneficial and harmful roles of indigenous microbiota in the human body. F. Described biofilms and their impact on human health. Microbial Relationships and Ecological Roles MicroPara 2023-2024 Angeles University Foundation - College of Nursing Page 1 of 7  ESTIMATED TIME ALLOTMENT Lecture Discussion 2.5 Hours A 30 ITEM MULTIPLE CHOICE TYPE OF QUIZ WILL BE GIVEN 30 Minutes AMONGST STUDENTS TOTAL HOURS 3 HOURS Microbial ecology is the study of microorganisms (including bacteria, fungi, viruses, and archaea) in their natural environments and their interactions with each other, with other organisms, and with their surroundings. Understanding microbial ecology is crucial because it provides insights into how microorganisms behave and function in different ecological niches within the human body and in the broader environment. Microorganisms occupy specific habitats within the human body (such as skin, mucous membranes, and gastrointestinal tract) where they form complex communities known as microbiota. Each niche within the body has unique environmental conditions (pH, temperature, oxygen levels) that shape the composition and function of microbial communities. Microorganisms interact with each other and with human cells. These interactions can be mutualistic (beneficial to both microbe and host), commensal (beneficial to microbe without harming the host), or pathogenic (causing disease). Microbial communities are dynamic and can change in response to factors such as diet, medications (like antibiotics), and environmental exposures. Microbial ecology explores how the microbiota influences human health, including roles in immune system development, metabolism, and protection against pathogens. We should gain insights into the importance of maintaining a balanced microbiota and strategies to support microbial health, such as probiotics and hygiene practices. Microbial ecology provides a framework for understanding the complex and essential roles of microorganisms in health and disease contexts relevant to nursing practice. It emphasizes the interconnectedness between microbial communities, human hosts, and their environments, fostering a holistic approach to healthcare management and infection prevention. SYMBIOTIC RELATIONSHIPS INVOLVING MICROORGANISMS Symbiosis or symbiotic relationship is defined as the living together or close association of two dissimilar organisms. The organisms that live together in such a relationship are referred to as symbionts. Symbiotic relationships can be categorized into four main types: neutralism, commensalism, mutualism, and parasitism. 1. Neutralism A symbiotic relationship in which neither symbiont is affected by the relationship. In this type of relationship, the organisms coexist without impacting each other’s well-being or functionality. True neutralism is relatively rare because most microorganisms interact in some manner. Microbial Relationships and Ecological Roles MicroPara 2023-2024 Angeles University Foundation - College of Nursing Page 2 of 7  2. Commensalism A symbiotic relationship that is beneficial to one symbiont and of no consequence to the other. In this type of relationship, one organism (the commensal) benefits while the other (the host) remains unaffected. An example of commensalism is the relationship between certain non-pathogenic bacteria and humans, where bacteria reside on the skin or mucous membranes without harming the host. 3. Mutualism A symbiotic relationship that is beneficial to both symbionts. In mutualism, both organisms derive some benefit from the relationship. An example of mutualism is the relationship between humans and their gut microbiota, where the bacteria aid in digestion and synthesize vitamins, while the human host provides a nutrient-rich environment for the bacteria. 4. Parasitism A symbiotic relationship that is beneficial to one symbiont (the parasite) and detrimental to the other symbiont (the host). Parasites derive nutrients and shelter from the host, often causing harm in the process. Examples include pathogenic bacteria, viruses, and protozoa that cause diseases in humans. Indigenous Microbiota of Humans A person’s indigenous microbiota includes all the microorganisms that reside on and within that person. These microorganisms consist of bacteria, fungi, viruses, and sometimes archaea, which can be both harmless and beneficial to human health. Harmless and helpful microbes take up residence on the skin, at all body openings, and on mucus membranes that line the digestive tract and the genitourinary tract. These moist, warm environments provide excellent conditions for microbial growth. Conditions for proper growth, including moisture, pH, temperature, and available nutrients, vary from one anatomic site to another. For example, the acidic environment of the stomach and the slightly acidic pH of the skin select for acid-tolerant microbes, while the anaerobic environment of the large intestine supports obligate anaerobes. In addition to the resident microbiota, transient microbiota take up temporary residence on and within humans. The body is constantly exposed to microorganisms from the external environment; these microbes are attracted to moist, warm body areas. Transient microbes are only temporary for the following reasons: 1. Washing Away: They may be washed from external areas by bathing or other hygiene practices, removing them from the skin surface. 2. Competition: They may not be able to compete with the established resident microbiota, which occupy niches and utilize available nutrients. 3. Host Environment: They may fail to survive in the acidic or alkaline environment of the site. For instance, the acidic pH of the stomach and skin can inhibit the growth of many transient organisms. 4. Antimicrobial Substances: They may be killed by substances produced by resident microbiota, such as bacteriocins, which are proteins produced by bacteria that inhibit the growth of similar or closely related bacterial strains. 5. Bodily Secretions: They may be flushed away by bodily secretions or excretions, such as mucus, saliva, urine, and feces, which constantly renew the microbial communities by physically removing transient organisms. Microbial Relationships and Ecological Roles MicroPara 2023-2024 Angeles University Foundation - College of Nursing Page 3 of 7 Superinfection refers to the phenomenon where an organism, typically present in low numbers within a particular environment or host, undergoes rapid and excessive growth under certain conditions, leading to clinical manifestations of disease. An important opportunistic pathogen known for causing superinfections is the yeast Candida albicans. This organism normally resides in small numbers near body openings such as the mouth, vagina, or lower intestines. Under normal circumstances, Candida albicans exists as a commensal organism, meaning it coexists peacefully with other microorganisms in the body without causing harm. However, when conditions shift, such as a decrease in the population of other resident microbiota (normal microbial flora), Candida albicans can capitalize on the opportunity and proliferate rapidly. This can occur due to factors like antibiotic therapy, which disrupts the normal balance of microbial communities (dysbiosis), allowing Candida albicans to overgrow and cause infection. The resulting disease caused by Candida albicans overgrowth is known as candidiasis. Depending on the site of infection, candidiasis can manifest as oral thrush (in the mouth), vaginal yeast infections (vulvovaginal candidiasis), or gastrointestinal candidiasis (in the intestines). Symptoms typically include discomfort, itching, redness, and in severe cases, systemic candidiasis can occur, affecting internal organs and potentially leading to serious complications, especially in immunocompromised individuals. Microbiota of the Skin: The skin harbors a diverse community of microorganisms known as the skin microbiota. This microbiota primarily consists of anaerobic bacteria and fungi. Areas of the skin that are moist and warm, such as the folds between toes and fingers, as well as hairy areas with sweat and oil glands (like underarms and groin), provide ideal conditions for microbial growth. In contrast, dry and calloused skin areas typically have fewer resident bacteria. The skin microbiota play a crucial role in protecting against pathogenic invasion by occupying ecological niches and competing for resources with potential pathogens. Microbiota of the Ears and Eyes: Outer Ear and Auditory Canal: These areas harbor microorganisms similar to those found on the skin. The outer ear and auditory canal are typically colonized by skin-associated bacteria and fungi. Middle and Inner Ear: Under normal circumstances, the middle and inner ear are considered sterile environments. However, pathogens from the external environment can potentially reach these areas through the Eustachian tube, especially during activities like coughing, sneezing, or blowing the nose, which can introduce microorganisms and lead to infections. Eyes: The external surface of the eye is protected by tears, mucus, and sebum, which help lubricate, cleanse, and shield the eye. Tears contain lysozyme and other antimicrobial substances that help to control the numbers of indigenous microbiota on the eye's surface. This continuous cleansing and protective mechanism helps to Microbial Relationships and Ecological Roles MicroPara 2023-2024 Angeles University Foundation - College of Nursing Page 4 of 7 maintain a relatively low microbial load on the surface of the eye. Microbiota of the Respiratory Tract: Upper Respiratory Tract: The nasal passages and throat host a diverse population of microorganisms. These areas are lined with moist mucous membranes that provide favorable conditions for microbial growth. The microbiota of the upper respiratory tract play roles in immune modulation and defense against invading pathogens. Lower Respiratory Tract: Normally, the lower respiratory tract, including the lungs, is considered sterile due to efficient defense mechanisms that include mucociliary clearance (where mucus traps and removes particles and microorganisms) and immune surveillance by resident immune cells. However, microbial invasion into the lower respiratory tract can occur in conditions such as pneumonia or when the defense mechanisms are compromised. Microbiota of the Oral Cavity The oral cavity hosts a diverse community of microorganisms, with the most common indigenous microbiota including various species of α-hemolytic streptococci. Streptococcus mutans is particularly notable for its role in dental plaque formation, contributing to dental caries (cavities). The oral microbiota is influenced by factors such as diet, oral hygiene practices, and the presence of dental restorations. Maintaining a balanced oral microbiota is important for oral health, as dysbiosis can lead to dental and periodontal diseases. Microbiota of the Gastrointestinal Tract: Stomach: Gastric enzymes and the acidic pH of the stomach typically prevent the growth of indigenous microbiota. Most transient microbes are killed by these harsh conditions. However, Helicobacter pylori, a Gram-negative bacterium, can survive in the stomach and is associated with the development of ulcers. Small Intestine: ○ Duodenum: Bile inhibits the growth of most microbes, resulting in relatively few microbiota in this part of the small intestine. ○ Jejunum and Ileum: These segments of the small intestine have a more abundant and diverse microbial population due to the favorable conditions provided by the presence of nutrients and less hostile pH levels compared to the stomach and duodenum. Large Intestine (Colon): The colon contains the largest number and variety of microorganisms in the body, including bacteria, fungi, protozoa, and viruses. Many of these microbiota are opportunistic, meaning they can cause disease if they gain access to other parts of the body. The microbiota of the colon play roles in digestion, vitamin synthesis, and immune system modulation. Microbes are regularly removed from the GI tract through defecation. Microbial Relationships and Ecological Roles MicroPara 2023-2024 Angeles University Foundation - College of Nursing Page 5 of 7 Microbiota of the Genitourinary Tract: Kidneys, Ureters, and Bladder: These organs are typically sterile under healthy conditions. Distal Urethra and External Opening of the Urethra: The distal urethra and its external opening harbor various microbes, including bacteria, yeast, and viruses, which can potentially cause infections if they migrate upwards towards the bladder or kidneys. Reproductive Systems: ○ Women: The reproductive tract is usually sterile, except for the vagina. Vaginal microbiota composition varies with age and hormonal changes. During reproductive years, the presence of lactobacilli helps maintain an acidic environment, which suppresses the growth of potential pathogens. Changes in vaginal microbiota can lead to conditions like bacterial vaginosis (BV) or yeast infections. ○ Men: The male reproductive tract is typically sterile, except during infections. Beneficial and Harmful Roles of Indigenous Microbiota: 1. Microbial Antagonism: Indigenous microbiota compete with potential pathogens for colonization sites and nutrients, thereby preventing infections through a mechanism known as microbial antagonism. 2. Opportunistic Pathogens: Many indigenous microbiota can act as opportunistic pathogens under certain conditions, such as immune suppression or disruptions in normal microbiota balance. 3. Biotherapeutic Agents: In cases where antibiotics or other therapies disrupt the balance of indigenous microbiota, biotherapeutic agents like probiotics (e.g., lactobacilli in yogurt) can be used to restore microbial balance and prevent complications such as yeast infections. Microbial Communities: Biofilms: Microbes often form biofilms, which are structured communities adhering to surfaces such as tissues or medical devices (e.g., catheters, prosthetic implants). Biofilms are resistant to antibiotics, disinfectants, and host immune responses, making them difficult to eradicate and a significant medical concern. Synergistic Infections: Sometimes, two or more microorganisms cooperate synergistically to cause infections that neither could cause alone. This synergistic relationship is known as a synergistic or polymicrobial infection, which can complicate diagnosis and treatment. Microbial Relationships and Ecological Roles MicroPara 2023-2024 Angeles University Foundation - College of Nursing Page 6 of 7 EVALUATION EXAM You will be given a 30-item quiz as an assessment of your theoretical learnings about the Introduction of Microbiology. LEARNER’S RESOURCES and READINGS Bartolome, F.A. & Quiles, E.P. (2024). Microbiology and Parasitology: A textbook and Laboratory manual for the Health Sciences: C&E Publishing, Inc. Bartolome, F.A. & Quiles, E.P. (2020). Microbiology and Parasitology: A textbook and Laboratory manual for the Health Sciences: C&E Publishing, Inc. Barer, Mike (2019). Medical Microbiology: A Guide to Microbial Infections: Pathogenesis, Immunity, Laboratory Investigation and Control. Amsterdam, Netherlands: Elsevier Cowan, Kelly M. ( 2018) Fundamentals of Microbiology. Jone and Bartlett Learning: Burlington, Ma Engelkirk, Paul G. (2018). Burton’s Microbiology for the Health Science (11th edition). Philadelphia: Wolters Kluwer Health Talaro, Kathleen P. (2018). Foundations in Microbiology.New York, NY: McGraw-Hill Education WEBSITES: 1. http://www.microbes.info 2. http://www.mic.sgmjournals.org/ 3. http://www.asm.org/ 4. http://www.microbiologytext.com/ 5. http://www.microbiologyonline.org.uk/ 6. http://www.nature.com/nmicro/index.html 7. http://www.ebscohost.com PREPARED BY: MARVIC S. RUBIO, RN, MSN DALE N. TUAZON, RN, MSN PEER REVIEWED BY: MICHELLE KHO-ENRIQUEZ, RN, MNc ANALYN R. RUBIO, RN, MNc REVIEWED AND EVALUATED BY: MARY ANGELICA BAGAOISAN, RN, MAN LEVEL 1 COORDINATOR DEBBIE Q. RAMIREZ, RN, PH. D ASSISTANT DEAN APPROVED BY: ZENAIDA S. FERNANDEZ,RN, PH. D DEAN Microbial Relationships and Ecological Roles MicroPara 2023-2024 Angeles University Foundation - College of Nursing Page 7 of 7