Questions and Answers
Which of the following bacteria is associated with causing diphtheria?
What is a common result of virulent strains of Escherichia coli?
Diarrhea
Salmonella typhi can live in non-human hosts.
False
What common infection can result from catheter use in hospitalized patients?
Signup and view all the answers
Chlamydia trachomatis is frequently reported as the most common sexually transmitted infection in the ______.
Signup and view all the answers
What is the hallmark of primary syphilis?
Signup and view all the answers
Normal flora are only found within the internal organs of a healthy person.
Signup and view all the answers
What does the Mantoux test evaluate?
Signup and view all the answers
What is the characteristic shape of Mycobacteria tuberculosis?
Signup and view all the answers
The treatment for syphilis usually involves ______.
Signup and view all the answers
What is the main characteristic of chronic infections?
Signup and view all the answers
Viruses are considered living organisms.
Signup and view all the answers
What is the scientific name for humans?
Signup and view all the answers
What type of bacteria are known to be beneficial?
Signup and view all the answers
All living cells are divided into eukaryotes and prokaryotes.
Signup and view all the answers
What are the three types of bacteria based on oxygen requirements?
Signup and view all the answers
What is the function of the bacterial glycocalyx?
Signup and view all the answers
Match the following bacteria with their diseases:
Signup and view all the answers
The first name in the scientific naming system is called the ______.
Signup and view all the answers
What process do bacteria undergo for reproduction?
Signup and view all the answers
Which of the following is a method of transmission in the chain of infection?
Signup and view all the answers
Endospores can remain dormant for thousands of years.
Signup and view all the answers
What is the primary composition of a bacterial cell wall?
Signup and view all the answers
What is the initial infection caused by the varicella-zoster virus?
Signup and view all the answers
What is the reactivation of the varicella-zoster virus called?
Signup and view all the answers
Which viruses are associated with oncogenic infections?
Signup and view all the answers
What disease is caused by the Human papilloma virus (HPV)?
Signup and view all the answers
What are prion diseases?
Signup and view all the answers
Kuru affects only those who consume infected meat.
Signup and view all the answers
Which fungal infection is caused by dermatophytes?
Signup and view all the answers
What are the two main groups of parasitic infections?
Signup and view all the answers
What is the common transmission route of pinworm infections?
Signup and view all the answers
Which one of the following is NOT a common nosocomial infection?
Signup and view all the answers
What does disinfection refer to?
Signup and view all the answers
Sterilization is an absolute process that kills all microbes.
Signup and view all the answers
What am I if I weaken the nervous system, causing insanity and death?
Signup and view all the answers
What am I if I affect those who had chickenpox before and reside in ganglia?
Signup and view all the answers
What am I if I prefer the liver and am named after this organ?
Signup and view all the answers
What am I if I favor the cervix and can cause warts?
Signup and view all the answers
What am I if I am named after my appearance on the skin and make humans itch?
Signup and view all the answers
What am I if I appear white when I grow in colonies and remain dormant?
Signup and view all the answers
What am I if I have four flagella and cause greenish discharge?
Signup and view all the answers
What am I if I am a parasite that replicates in mosquitoes and humans?
Signup and view all the answers
What am I if I look like a ribbon and require a cow or pig in my life cycle?
Signup and view all the answers
What am I if I look like small coiled threads and spread by the feco-oral route?
Signup and view all the answers
What am I if I spread by the feco-oral route and hatch first in the intestine?
Signup and view all the answers
What am I if I can cause anemia and enter via intact skin?
Signup and view all the answers
______ is the ability of the bacteria to get attached.
Signup and view all the answers
______ is the degree of pathogenicity.
Signup and view all the answers
Human acts as a ______ in spreading tuberculosis.
Signup and view all the answers
Normal flora has the function of ________ and ________.
Signup and view all the answers
E.coli is a __________ based on its oxygen requirement.
Signup and view all the answers
_________ is a separate double-stranded DNA molecule.
Signup and view all the answers
Gram negative bacteria uses ______ for attachment.
Signup and view all the answers
_________ cocci that form grape-like clusters.
Signup and view all the answers
What is the most common method used for sterilization in hospitals?
Signup and view all the answers
What is the most effective antiseptic used in homes?
Signup and view all the answers
What chemical agent is used to purify water?
Signup and view all the answers
What method is used for sterilizing glassware?
Signup and view all the answers
What method is used for sterilizing vaccines?
Signup and view all the answers
What method is used for sterilizing heat-sensitive materials?
Signup and view all the answers
What is Phenol originally used for?
Signup and view all the answers
What is the main action of Chlorhexidine?
Signup and view all the answers
Which of the following is a widely used alcohol for cleaning skin?
Signup and view all the answers
Which of the following statements about surface-active agents is true?
Signup and view all the answers
What is the main use of Halogens?
Signup and view all the answers
The primary use of formaldehyde is to preserve tissue specimens.
Signup and view all the answers
What does the term 'Moist Heat' relate to in sterilization?
Signup and view all the answers
Which of the following is an example of a Physical Agent used in sterilization?
Signup and view all the answers
What common method is used to kill microbes in milk?
Signup and view all the answers
Dry heat sterilization requires a temperature of 180°C for 2 hours.
Signup and view all the answers
A solution of iodine with alcohol is known as ______.
Signup and view all the answers
What are bacterial resting cells called?
Signup and view all the answers
Cocci are a type of bacteria that are classified based on what characteristic?
Signup and view all the answers
Study Notes
Introduction to Microbiology
- Hand hygiene is crucial in nursing to prevent nosocomial infections.
- Nosocomial infections are a significant global health issue.
- Nursing professionals need microbiology knowledge for effective healthcare.
- Understanding infection spread aids in controlling it.
- Focus on bacteria as a major group of microbes is essential.
Microorganisms Overview
- Microorganisms are microscopic entities, including:
- Algae
- Fungi
- Protozoans
- Bacteria
- Viruses
- The human body contains approximately 10 trillion cells with 100 trillion microbes in the gut.
Prokaryotes
- Prokaryotes lack a nucleus; eukaryotes (plants, animals) have nuclei.
- Bacteria are classified as prokaryotic cells, containing scattered DNA and no membranous organelles.
- Bacterial cell walls are composed of peptidoglycan and reproduce via binary fission.
Bacteria: Good and Bad
- Most bacteria are beneficial, assisting in digestion and vitamin synthesis (e.g., Vitamin B, K) and used in food products (bread, cheese, yogurt).
- Harmful bacteria can cause diseases.
Bacterial Naming and Classification
- Binomial nomenclature, established by Carolus Linnaeus, provides scientific names in Latin.
- Example: Staphylococcus aureus (Genus: Staphylococcus, species: aureus).
- Bacteria classification is based on shape and arrangement:
- Shapes: cocci (spherical), bacilli (rod-shaped), spirilla (spiral).
- Arrangements: diplo (pairs), strepto (chains), staphylo (clusters).
Bacterial Structure
- Structures external to cell wall include glycocalyx, pili, and flagella.
- Internal structures: plasma membrane, cytoplasm (contains ribosomes and nucleoid).
- Glycocalyx: Gelatinous layer protecting against phagocytosis and aiding in attachment.
- Flagella: Motility structures aiding bacterial movement.
- Pili: Found in Gram-negative bacteria, facilitating host attachment.
Cell Wall and Gram Staining
- Gram-positive bacteria have thick peptidoglycan layers, while Gram-negative bacteria possess thinner layers and an outer membrane containing lipopolysaccharides.
- Gram staining differentiates bacteria based on cell wall structure, vital in identifying infections.
Bacterial Growth Requirements
- Optimal growth conditions include human body temperature and pH (6.5 - 7.5).
- Bacteria require water, carbon, and oxygen, with oxygen needs categorized as:
- Obligate aerobes: Require oxygen.
- Obligate anaerobes: Do not require oxygen.
- Facultative anaerobes: Can survive in both conditions.
Endospores
- Under unfavorable conditions, some bacteria form endospores, dormant and resistant cells.
- Endospores can remain inactive for thousands of years and are only killed by autoclave.
- Example: Clostridium tetani spores in soil can cause tetanus after entering the body through wounds.
Infection and Pathogenesis
- Infection refers to microorganisms multiplying within the body.
- Chain of infection includes:
- Pathogen (infectious agent)
- Reservoir (host/source)
- Portal of exit (exit route)
- Transmission methods (contact, vehicle, vector)
- Portal of entry (entry route)
- New host infection.
Medically Important Bacteria
- Gram-positive cocci examples include:
- Staphylococcus aureus (skin infections, food poisoning)
- Streptococcus (e.g., pharyngitis, pneumonia).
- Gram-negative cocci examples include:
- Neisseria meningitidis (meningitis)
- Neisseria gonorrhoeae (gonorrhea).
- Important Gram-positive bacilli:
- Clostridium tetani (tetanus)
- Corynebacterium diphtheriae (diphtheria).
- Important Gram-negative bacilli:
- Escherichia coli (E. coli, urinary tract infections).
- Salmonella typhi (typhoid fever).
Infection Control
- Breaking the chain of infection is essential for health workers.
- Preventive measures include hand hygiene, PPE, and isolation of sick patients.
- Infection control methodologies include disinfecting surfaces and enhancing host defenses through vaccinations and antibiotics.
Conclusion
- Understanding microbiology, especially the characteristics and behavior of bacteria, is fundamental to nursing practice and infection control in healthcare settings.### Mycobacteria tuberculosis
- Aerobic acid-fast bacilli, requiring special stains (e.g., Ziehl-Neelsen).
- Natural reservoir is humans; spread through droplet transmission, notably droplet nuclei.
- Responsible for Tuberculosis; bacilli enter lungs and are initially phagocytosed by macrophages.
- Some bacilli multiply within macrophages, forming tubercles that undergo necrosis and lead to caseous necrosis.
- Ruptured caseous tubercles can spread bacilli through the bloodstream.
- Calcification of outer tubercle layer can be visualized via X-rays.
Prevention and Diagnosis
- BCG vaccine (live attenuated M. bovis) is used for prevention.
- Tuberculin skin test (Mantoux test) involves the injection of purified protein derivative; a reaction of 10 mm or more within 48-72 hours indicates a positive result.
- Sputum staining is used for diagnostic purposes.
Treponema Pallidum and Syphilis
- Treponema pallidum is the causative agent of syphilis, transmitted via unprotected sexual contact or congenitally.
- Syphilis has three phases:
- Primary syphilis: Chancre (painless ulcer) at infection site occurs 2-10 weeks post-exposure.
- Secondary syphilis: Skin rashes and mucous membrane lesions develop 1-3 months later.
- Tertiary syphilis: Untreated cases may lead to gummas in various organs over 1-10 years.
Congenital Syphilis
- Results from transmission of Treponema pallidum to the fetus in utero, causing chronic infection.
Diagnosis and Treatment
- Diagnosis includes dark field microscopy and serological screening (e.g., VDRL).
- Treatment is typically with penicillin.
Normal Flora
- Comprises a permanent population of bacteria and fungi, not viruses or parasites.
- Located on body surface linings and mucous membranes; not found in internal organs.
Functions of Normal Flora
- Protection: Acts as a defense mechanism, preventing pathogen invasion (e.g., Lactobacillus).
- Nutrition: Intestinal flora produce B vitamins and vitamin K, deficiencies may occur due to antibiotics.
Opportunistic Pathogens
- Non-pathogenic microorganisms can cause infections in immunocompromised individuals (e.g., candidiasis in AIDS patients).
Carrier State
- Carriers harbor potential pathogens (e.g., Streptococcus pneumoniae, Salmonella typhi) without symptoms, posing an infection risk.
Bacterial Classification
- Bacteria are prokaryotic, classified by shape and arrangement (e.g., cocci, bacilli).
- Important groups include gram-positive cocci (staph, strepto) and gram-negative bacilli (E. coli, Salmonella).
- Medically significant other bacteria encompass Chlamydia trachomatis, Mycobacterium tuberculosis, and Treponema pallidum.
Virus Characteristics
- Viruses are the smallest microorganisms (20-300 nm), not visible with light microscopy, and require a host cell for replication.
- Lacks organelles and has limited enzymes, dependent on host metabolism.
Virus Structure
- Comprised of nucleic acids (DNA or RNA), a capsid, and potentially an envelope with glycoprotein.
Pathogenesis
- Viruses can cause disease through various infection patterns:
- Acute infections: Rapid onset with systemic spread (e.g., influenza, COVID-19).
- Chronic infections: Continued presence of the virus (e.g., HIV, Hepatitis B and C).
- Latent infections: Dormant after initial infection, can reactivate during immune compromise (e.g., herpes simplex, chickenpox).
- Oncogenic infections: Cause malignant changes in host cells (e.g., HPV, Hepatitis viruses).
Prion Diseases
- Rare infectious diseases caused by prions, which are malformed proteins lacking nucleic acids that induce misfolding of normal proteins.
- Kuru, seen in certain New Guinea tribes, is a notable example, transmitted through consumption of infected human brain tissue.
Summary of Key Infections
- Acute infections: Include influenza, Zika, rabies, Dengue, SARS, and COVID-19.
- Chronic infections: Include HIV, Hepatitis B, and C.
- Latent infections: Include herpes simplex virus and varicella zoster (chickenpox).
- Oncogenic infections: Include HPV and Hepatitis viruses.
Introduction to Fungal and Parasitic Infections
- Fungal infections can result from eukaryotic fungi, often residing in the environment. Examples include ringworm and candidiasis.
- Parasitic infections include a range of protozoa and helminths affecting human and animal populations.### Fungal Infections
- Common fungal infections include Ringworm, Tinea Versicolor, and Candidiasis.
- Ringworm is caused by dermatophytes, affecting keratinized structures with symptoms like intense itching, worsened by heat and humidity.
- Tinea Versicolor, caused by Malassezia furfur, leads to hypopigmented skin areas, often asymptomatic, more prevalent in hot, humid conditions.
- Candida albicans, part of normal flora in various body areas, causes opportunistic infections when host defenses are compromised, such as oral thrush, vulvovaginitis, and chronic nail infections.
Parasitic Infections
- Parasitic organisms are non-mutual symbionts, classified into protozoa (single-celled) and helminths (multicellular).
- Protozoa include:
- Trichomonas vaginalis: causes genital infections transmitted by sexual contact, leading to foul-smelling discharge.
- Entamoeba histolytica: causes amoebic dysentery, common in poor sanitation, resulting in painful defecation with bloody stools.
- Plasmodium: causes malaria, transmitted by Anopheles mosquitoes, resulting in fever and severe complications like renal failure.
Helminths
- Multicellular parasites with well-defined body systems, including:
- Cestodes: segmented worms like tapeworms.
- Nematodes: unsegmented worms include pinworms, roundworms, and hookworms.
- Tapeworms live in intestines, absorbing nutrients, and are spread via the fecal-oral route. They can cause neurocysticercosis upon ingestion of infected meat.
- Pinworms cause anal itching, with females laying eggs around the anus, leading to re-infection through scratching.
- Roundworms migrate through the body, potentially causing malnutrition and inflammation in children.
- Hookworms feed on blood, leading to iron deficiency anemia, affecting around 800 million people globally.
Nosocomial Infections
- Acquired during hospital stays, associated with microorganisms, compromised host status, and transmission chains.
- Common infection types include:
- Urinary Tract Infections (50%)
- Surgical Wound Infections (25%)
- Lower Respiratory Tract Infections
- Bacteremia from IV drips.
Microbial Sterilization & Disinfection
- Critical for preventing infection in healthcare, requires understanding of microbial growth concepts introduced by Semmelweis and Lister.
- Disinfection kills most microorganisms, while sterilization removes all microbes, including endospores.
- Various agents and methods used:
- Chemical Agents: Phenol, chlorhexidine, alcohol, halogens (chlorine, iodine), aldehydes (formaldehyde, glutaraldehyde).
- Physical Agents: Heat (moist, dry, pasteurization), filtration for heat-sensitive materials, radiation.
Mechanisms of Action
- Anti-microbial agents work by altering membrane permeability or damaging proteins and nucleic acids, with varying effectiveness across different types.
- Moist heat (boiling, autoclaving) and dry heat are effective sterilization methods, alongside pasteurization for specific applications like milk.
Summary
- Understanding the spectrum of fungal and parasitic infections is crucial for diagnosis and treatment.
- Knowledge of nosocomial infection prevention and microbial control is essential for healthcare settings.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the crucial concepts introduced in the first lecture of the Microbiology course. It focuses on the importance of hand hygiene and understanding nosocomial infections in healthcare. A solid grasp of microbiology is essential for nursing professionals to effectively manage patient care.
