Group 5 Presentation

• Presentation of Pathogens
• Presenters


  • Cadlaon, Nielsen
  • Catague, Kaye Ann
  • Escalante, Crisyl Joy
  • Maliwanag, Angela Conception
  • Vargas, Ralf Lorenz
  • Velarde, Jinneca
• Pathogens


  • #4 - Corynebacterium diptheria
  • #1 - Helicobacter pylori
  • #2 - Treponema pallidum
  • #3 - Leptospira interrogans
  • #5 - Streptococcus pneumoniae

  
• Helicobacter pylori commonly known as "H. Pyroli" is a type of bacteria that infects stomach

  
• Helicobacter pylori


  • Gram-negative, microaerophilic bacterium that can infect humans
  • Causes inflammation and ulceration

  
• Transmission of H. pylori


  Can occur via the fecal-oral, gastric-oral, oral-oral, or sexual routes
• Helicobacter pylori


  • Normally has a curved to spiral shape
  • Some have short or tapered rod shape
  • Measures for about 2 to 4 micrometer (μm) in length and 0.5 to 1 μm in width
  • Usually arranged in clusters or in chains
  • Not spore forming, relies on its structure for various mechanisms

  
• Growth requirements of Helicobacter pylori

  • 5-10 % oxygen concentration
  • 37 to 42 degrees Celsius
  • Low pH environment
  • Tolerates high osmotic pressure
  • Prefer low level of oxygen but can tolerate its presence
  • Relies on production of enzymes that helps it survive
• Diseases caused by Helicobacter pylori

  • Gastritis
  • Peptic Ulcer
  • Gastric Cancer
  • MALT Lymphoma

  
• Peptic ulcer


  • Open sores that develop on the inside lining of your stomach and the upper portion of your small intestine
  • Weakens the protective mucous coating of the stomach and duodenum, thus allowing acid to get through to the sensitive lining and both acid and the bacteria irritate the lining and cause a sore, or ulcer

  
• Gastritis


  • Inflammation of the stomach lining
  • H pylori infect the stomach lining and weakens the protective barrier leading to inflammation that damages the stomach lining

  
• MALT lymphoma


  • A rare form of non-Hodgkin lymphoma
  • Gastric MALT lymphoma caused by H. Pylori lead to a chronic stomach infection

  
• Gastric Cancer


  • H. Pylori make a toxin called Cytotoxin-associated gene A (CagA) that gets injected into the junctions where cells of the stomach lining meet
  • Once inside cells, CagA can cause them to become cancerous by removing controls on cell growth and enhancing cell motility
  • Long-term exposure of cells to the toxin causes chronic inflammation

  
• Helicobacter pylori defense mechanisms

  • Urease activity - Catalyzes hydrolysis of urea present in the stomach to yield NH3 and CO2, thus elevating the pH to neutral as necessary for survival
  • Flagella-mediated motility - Helping the bacterium move towards host gastric epithelial cells
  • Bacterial Adhesins - Blood-antigen binding protein A (BaBA Adhesin), Sialic acid-binding adhesin (SaBA Adhesin)
  • Effector Proteins /Toxins - Cytotoxin-associated gene A (Cag A), Vacuolating cytotoxin (VaCA)

  
• Cytotoxin-associated gene A (Cag A)

  Effector toxin used by H. pylori that becomes cancerous

  
• Innate Immune response against Helicobacter pylori

  • Neutrophils
  • Macrophages
  • Dendritic cells
• Adaptive immune response against Helicobacter pylori

  • CD4+T Cell responses (Th1,Th2,Treg cells)
  • Antibodies IgA and IgG
• Clinical manifestations of diseases caused by Helicobacter pylori

  • Peptic Ulcers - Abdominal pains, nausea, vomiting and bloating
  • Gastritis - Abdominal pain, bloating, indigestion, and gastrointestinal bleeding
  • MALT Lymphoma - Difficulty swallowing, feeling bloated after eating, feeling full after only eating a small amount of food, heartburn, indigestion, nausea, stomach pain, unintentional weight loss, and vomiting
  • Gastric Cancer - Persistent indigestion, tummy pain, feeling sick (nausea) or being sick (vomiting), weight loss

  
• Treponema pallidum, formerly known as Spirochaeta pallida, is a microaerophilic spirochete bacterium
• Treponema pallidum


  • Spiral-shaped or helical shape
  • Diameter: 0.2 to 0.3 micrometers, Length: 5 to 15 micrometers
  • Covered by a thick phospholipid membrane
  • Spiral arrangement due to internal flagella, called periplasmic flagella or endoflagella
  • Not a spore-forming bacterium

  
• Growth requirements of Treponema pallidum

  • Anaerobic bacterium, survives in oxygen-free environments
  • Optimal temperature between 34°C and 36°C
  • Prefers a neutral pH (around 7.0)
  • Thrives in an isotonic osmotic environment
  • Non-fermenting bacterium
• Diseases caused by Treponema pallidum

  • Syphilis
  • Bejel (Endemic Syphilis)
  • Yaws
• Syphilis


  • A sexually transmitted infection that can result in sores developing on or near the lips, mouth, anus, and genital area
  • A chronic illness that primarily affects humans, spread vertically during childbirth or through sexual contact between an infected mother and her offspring
• Bejel (Endemic Syphilis)


  • A chronic infection caused by Treponema pallidum, mostly found in arid parts of the Middle East, Asia, and Africa
  • Mainly contagious through intimate contact and primarily affects children
• Yaws


  • A chronic infectious disease caused by Treponema pallidum, primarily affecting children in tropical regions, especially in Africa, Asia, and the Pacific
  • Typically spreads by direct skin-to-skin contact
• Pathogenesis of Treponema pallidum


  • Highly invasive pathogen that quickly spreads within the host
  • Outer membrane has few surface-exposed proteins, allowing it to evade the immune system
  • Lacks traditional lipopolysaccharide (LPS), but possesses inflammatory-inducing lipoproteins
  • Evades the immune system through antigenic variation, limiting surface-exposed proteins, suppressing the immune response, and localizing in specific tissues to avoid detection by immune cells
• Innate Immune Responses against Treponema pallidum


  • Treponema pallidum evades immune detection through poor recognition by the innate immune system, while macrophages help clear the bacteria through phagocytosis
  • This stealthy behavior explains why syphilis often lacks systemic inflammatory symptoms, despite the challenges it presents
• Clinical Manifestations of Syphilis

  • Primary Syphilis - Chancre: A painless sore at the site of infection (genitals, rectum, or mouth)
  • Secondary Syphilis - Skin Rashes, Fever, Swollen Lymph Glands, Hair Loss, and Fatigue
  • Latent syphilis - No visible symptoms, infection remains in the body but is not actively causing symptoms
  • Tertiary Syphilis - Organ Damage: Neurological problems, cardiovascular issues, and more
• Preventions for Syphilis


  • Safe Sexual Practices - Using condoms appropriately and consistently
  • Regular Testing - Get tested regularly for sexually transmitted infections
  • Treatment and Partner Notification - Let sexual partners know if diagnosed with syphilis so they can get tested and receive proper care
  • Early Diagnosis and Treatment - Seek immediate medical attention for testing and treatment if exposed to Treponema pallidum
  • Avoiding Risky Behaviors - Avoid or reduce actions that raise the possibility of syphilis infection
• Regularly get tested for sexually transmitted infections, such as syphilis, particularly if you participate in high-risk sexual activities or have several sexual partners.
• Treatment and Partner Notification


  Let your sexual partners know if you've been diagnosed with syphilis so they can get tested and, if needed, receive the proper care.
• Preventions for Syphilis


  • Early Diagnosis and Treatment: Seek immediate medical attention for testing and treatment if you think you may have syphilis or have been exposed to Treponema pallidum.
  • Avoiding Risky Behaviors: Avoiding or reducing actions that raise the possibility of syphilis infection, such as sharing needles and unprotected intercourse, can help prevent against infection.
• Leptospira interrogans is a spirochaete bacteria found in warm tropical regions, capable of surviving for extended periods in soil or water. It is pathogenic to animals and humans, causing flu-like symptoms and potential kidney and liver damage. In humans, infection is commonly spread through contact with contaminated water or soil, particularly through animal urine. Farmers and veterinarians are among those at higher risk of serious infection.

  
• Leptospira interrogans was first discovered by Dutch scientist, Adolph Weil


  1915
• Leptospira interrogans


  Commonly known simply as "leptospira."
• Leptospira


  • Flexible, spiral-shaped, Gram-negative spirochete with internal flagella

  
• Leptospira interrogans is gram-negative due to its cell wall structure, which includes a thin layer of peptidoglycan between an outer membrane and a cytoplasmic membrane. This is a key feature that distinguishes it from gram-positive bacteria.
• Unique Characteristics of Leptospira interrogans

  • Spiral Shape: Its spiral shape helps it move efficiently through host tissues.
  • Flagella: Internal flagella enable corkscrew-like motion, aiding penetration and immune evasion.
  • Environmental Survival: It can survive in water and soil for extended periods.
  • Host Adaptation: It can infect a wide range of host species.
  • Antigenic Variation: Changes surface antigens, evading the immune system.
  • Biofilm Formation: Forms biofilms, protecting against the immune system and antibiotics.
  • Zoonotic Transmission: Transmitted from animals to humans, often through contaminated environments or direct contact.
• Leptospira interrogans is unique among bacteria due to its highly motile corkscrew-like motion, ability to survive in water and soil for long periods, wide host range, and transmission primarily through animal urine and contaminated environments.

  
• Arrangement of Leptospira interrogans

  • Spiral-shaped bacteria, often found in pairs, clusters, or solitary, with hooked ends, and a length of 6 to 20 micrometers. They are commonly found in water and soil.