Pathology 15

• Dr. Azmiza Syawani Jasni is a lecturer in the Department of Medical Microbiology, Faculty of Medicine and Health Sciences, UPM.
• MDR3003 is a course titled "Introduction to Bacteriology".
• The learning objectives of the course include describing the properties and classification of medically important bacteria, explaining the host-parasites relationship, discussing the epidemiology, mode of transmission and risk factors related to bacterial infection, and outlining the laboratory modalities related to bacterial infections.
• Prokaryotic and Eukaryotic Cells are two basic types of cell; prokaryote and eukaryote.
• Prokaryote: a cell lacking a nucleus and other organelles (e.g., bacteria and archaea).
• Dust can be a source of hospital-acquired infections.
• Vehicle transmission is when an inanimate 'vehicle' becomes contaminated and then serves as a source of infection.
• Fomites are inanimate objects that can become contaminated and serve as a source of infection.
• Examples of fomites include surgical instruments, drink containers, bedding, door handles, and needles.
• Eukaryote: a cell possessing a membrane-enclosed nucleus and usually other organelles (e.g., algae, fungi and protozoa).
• The mode of transmission of dust is through contact.
• An animal can transmit diseases to humans through bites or scratches, or when handling animal waste.
• Disease-causing microorganisms can pass from an infected person to a healthy person through physical contact, such as touching, kissing, sexual contact, or contact with oral or wound secretions.
• Examples of diseases that can be transmitted through dust include chicken pox, pertussis, conjunctivitis, and STDs.
• Morphology of prokaryotes includes coccus, rod, spirillum, spirochete, budding and appendage, filamentous.
• A comparison of prokaryotic and eukaryotic cells includes features such as size, nuclear membrane, cell wall, cytoplasmic structures, and internal structure of bacteria.
• Streptococcus pneumoniae is responsible for diseases like pneumonia, sinusitis and otitis media, meningitis, and bacteraemia.
• pneumoniae); cell wall includes teichoic acid rich in phosphorylcholine (C polysaccharide) o Able to colonize oropharynx and spread into normally sterile tissues o Stimulate local inflammatory response and evade phagocytic killing.
• Enterococcus is responsible for diseases like pneumonia, sinusitis and otitis media, meningitis, and bacteraemia.
• Streptococcus pyogenes, also known as Group A Streptococcus, is responsible for suppurative diseases such as pharyngitis, soft tissue infections, and streptococcal toxic shock syndrome, as well as nonsuppurative diseases like rheumatic fever and glomerulonephritis.
• Streptococcus agalactiae, also known as Group B Streptococcus, is responsible for diseases such as neonatal infections in pregnant women, endometritis, wound infections, and urinary tract infections, as well as other adult infections like bacteraemia, pneumonia, bone and joint infections, and skin and soft tissue infections.
• The internal structure of bacteria includes structure of bacterial cell structures such as capsule/slime layer, cell wall, cell membrane, chromosome, cytoplasm, flagellum, inclusion, pilus (fimbria), plasmid, and ribosomes (70S).
• The bacterial cell wall is made up of peptidoglycan, a long chain of sugars linked to amino acids, and its primary functions are to give shape and rigidity to the cells and protect cells from osmotic lysis.
• Gram +ve and Gram – ve bacteria have different cell wall structures.
• Populations at greatest risk for Mycobacterium tuberculosis disease are foreign-born or travellers to endemic countries, immunocompromised patients (particularly those with HIV infection), drug or alcohol abusers, and individuals exposed to diseased patients.
• Primary infection of Mycobacterium tuberculosis is pulmonary.
• Bacillus cereus is a spore-forming, motile, Gram-positive rod that produces heat-stable and heat-labile enterotoxin, and tissue destruction is mediated by cytotoxic enzymes, including cereolysin and phospholipase C.
• Mycobacterium tuberculosis is the only natural reservoir and person-to-person spread by infectious aerosols is a common method of transmission.
• Bacillus cereus is ubiquitous in soils throughout the world and people at risk include those who consume food contaminated with the bacterium, those with penetrating injuries, those who receive intravenous injections, and immunocompromised patients exposed to Bacillus cereus.
• Mycobacterium tuberculosis is an acid-fast, aerobic rod with a lipid-rich cell wall that is resistant to traditional stains, disinfectants, detergents, common antibacterial antibiotics, and host immune response.
• Enterococcus faecium is a bacterium that causes pneumonia, urinary tract infections, peritonitis, wound infections, and bacteraemia with or without endocarditis.
• Mycobacterium tuberculosis is capable of intracellular growth in alveolar macrophages and the disease is primarily from the host response to infection.
• Bacillus cereus is capable of causing gastrointestinal diseases (emetic and diarrheal forms), ocular infections, and an anthrax-like disease in immunocompetent patients.
• Flagellar arrangements include Polar, monotrichous, Lophotrichous, Polar, Peritrichous, and Flagella16.
• Ignaz Semmelweis was the first to demonstrate the first occurrence of human-to-human transmission in 1848.
• Bacterial endospores can have terminal, subterminal, or central morphologies, and are classified based on the nature of the cell walls, staining characteristics, physical characteristics, biochemical reactions, and ability to produce enzymes such as coagulase and catalase.
• Primary pathogens cause disease as a result of their presence or activity within the normal, healthy host, and their intrinsic virulence.
• There are four main modes of transmission: airborne, contact, vehicle, and vector-borne.
• The cytoplasmic membrane functions as a permeability barrier, protein anchor, and energy conservation site.
• Infection is the process of infecting or the state of being infected, infectious disease are illnesses caused by the spread of microorganisms, and a pathogen is a parasite causing infectious disease.