1.1 Microbial Diseases of the Nervous System.pptx

Microbial Diseases of the Nervous System 8/27/24  2 The Nervous System The nervous system consists of: 1) Brain 2) Spinal cord 3) A network of nerves throughou...

Microbial Diseases of the Nervous System 8/27/24  2 The Nervous System The nervous system consists of: 1) Brain 2) Spinal cord 3) A network of nerves throughout the body The nervous system is divided into TWO subdivisions: a) Central nervous system (CNS) b) Peripheral nervous system Aktive Grotesk Aktive Grotesk (PNS) Aktive Grotesk Aktive Grotesk Aktive Grotesk  Anatomy of Central Nervous System 3 CNS consists of the BRAIN and SPINAL CORD. subduralspace A three-layered membrane known as Meninges protect the brain and spinal cord. The three layers are: 1) Dura mater – outer membrane 2) Arachnoid membrane – middle membrane 3) Pia mater – Inner membrane Sub means under/below Subarachnoid space: It is the space between arachnoid and pia mater. It is filled with CSF. Filled with fluid that called a CSF(cerebro spinal fluid) Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  4 Cerebrospinal Fluid (CSF) Cerebrospinal fluid is found in the subarachnoid space between arachnoid and pia mater. Composition: CSF consists of water, proteins, glucose, sodium, and chloride. Function: Protects the brain & spinal cord, supplies nutrition and circulates waste away. Protectio, carry supplimints ,and waste away How to collect CSF sample: Can obtain CSF through Lumbar puncture (LP) & Ventricular tap (rare method). Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  5 Lumbar puncture (LP) for obtaining CSF Another name A lumbar puncture (LP), also called a spinal tap, is an invasive procedure used to collect a sample of cerebrospinal fluid (CSF) from the subarachnoid space in the spine. Procedure: Note:We collect three bottles of CSF During a lumbar puncture, a hollow needle is inserted through the skin in the lower back (lumbar region). The needle passes between the vertebrae to withdraw some cerebrospinal fluid (CSF). Precautions for Lumbar puncture: a) Should be performed only when absolutely necessary. b) Coagulation profile for patients with bleeding problems should be checked before lumbar puncture. c) No lumbar puncture should be done at site of localized infection. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  6 Lumbar puncture (LP) for obtaining CSF We collect three bottles of CSF http://medicoinfo.org/cerebrospinal-fluid-csf- significance-function-collection-patient-preparation- Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk complication-laboratory-analysis/  Cerebrospinal fluid (CSF) Analysis 7 Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  8 How do microorganisms enter the nervous system Microorganisms can enter nervous system via: 1) Skull or backbone fractures 2) Medical procedures 3) Along peripheral nerves 4) Blood or lymph Bacteria, viruses and fungi are the most common causes of nervous system infections. Inflammation of the meningis Meningitis is the inflammatory response to infection of meninges. Bacterial meningitis is generally more serious than viral meningitis. swelling of the brain Encephalitis results in the swelling of the brain, and it’s usually caused by Aktive Grotesk a viral infection. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  9 Bacterial Meningitis Symptoms of Bacterial Meningitis In the beginning there is fever, headache; which can be very severe, stiff neck that aches and feels tender and a positive Pain on knee (+ ) Kernig’s sign. No pain (-)no infection in nervouse systen These initial symptoms are followed by nausea and projectile vomiting. The appearance of resistance or pain during extension of the patient's knees beyond 135 May progress to degrees constitutes a positive Kernig's sign ‫التشنجات‬ seizures un and able coma. to control of muscles convulsions/seizures Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Laboratory diagnosis of CNS infections 10 For laboratory diagnosis of CNS infections Cerebrospinal fluid (CSF) collected through lumbar puncture is mostly used. 3 sterile bottles labeled 1, 2, and 3 are used for CSF collection to ensure enough sample is collected. Contain only pure CSF withput any unwanted material For bacteriological examination bottle number 3 is used. The reason is for using this bottle is to reduce/avoid contamination with microorganism and epithelium or blood from skin and soft tissue capillaries ruptured during the puncture. Laboratory procedures performed on CSF 1. Visual appearance 2. Microscopy 3. Culture 4. Biochemical analysis 5. Antigen/ antibody detection tests. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Laboratory Procedures performed on CSF 11 1. Visual Appearance: Observe CSF for clarity, color, and presence of particulates. 2. Microscopy: Microscopy for cerebrospinal fluid (CSF) focuses on cell counts and staining of microorganisms. A. Cell Count: To determine the number and type of cells present in the CSF. Specific patterns of WBCs Acid canfasthelp bactera in diagnosing the type of infection. B. Gram stain and Ziehl Neelsen stain: To identify the presence and type of bacteria in the CSF. Both these staining procedures are done if the WBC count is higher, indicated by clinical details or requested by doctor. C. Negative Staining: Capsulated yeast such as Cryptococcus neoformans, which causes meningitis in immunosuppressed patients can be visualized by negative staining Bacteria not stained it stay the same Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk just the background colored Aktive Grotesk  12 Laboratory Procedures performed on CSF D. Wet Preparation: A simple laboratory technique to observe live microorganisms. The test sample is placed in a drop of water or saline solution on a microscope slide and covered with a cover slip and observed under a microscope. Wet preparations can be performed on centrifuged or neat samples. Wet preparation is done for detection of: i. Naegleria fowleri: Causes acute meningitis. People swimming in infected water can contract this infection. The parasite enters the eye or though the nasal mucosa. ii. Trypanosoma brucei: Causes sleeping sickness. Spread by the bite of an infected tsetse fly. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  13 Laboratory Procedures performed on CSF 3. Culture Methods of culture for to detect infectious microorganisms vary depending on W.B.C result, clinical details and doctor's request. 1. Normal WBC: The neat CSF is inoculated onto chocolate agar and into enrichment broth. 2. Raised WBC: CSF is inoculated in 2 Blood agars (one aerobic and the other anaerobic), Chocolate agar and an enrichment broth are also used. Specific Pathogen Considerations Using special type of medium agar Suspected Tuberculosis (TB): If TB is suspected use Löwenstein-Jensen (L.J.) Agar, Kirshner’s medium or TB Bactec media. Suspected Fungi: Sabouraud’s agar is used for the isolation and cultivation of yeasts and fungi. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Laboratory Procedures performed on CSF 14 4. Biochemical analysis: Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  15 Laboratory Procedures performed on CSF Foreign particles that enter and activate the immune system 5. Antigen and antibody detection tests: Antibody produced against antigens a) Commercial kits of antibodies or antigens can be used for the detection of viruses, bacteria and yeast in the CSF. Various serological methods utilizing the antigens or antibodies include enzyme-linked immunosorbent assay (ELISA), Western blotting, agglutination tests and immunofluorescence assays. b) PCR and other DNA technologies that detect nucleic acid (DNA/RNA) in the CSF sample are also used. This method is quick and can accurately identify the disease- causing agent. It can also be used for the detection of dead bacterial cells. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  16 Haemophilus influenzae Meningitis Haemophilus influenzae are Gram-negative aerobic bacteria which are part of the normal throat microbiota. Age Group: Primarily affects children aged 6 months to 4 years. The cover of this bacteria Capsule Antigen: These bacteria contain Type b antigen. This antigen enhances the disease-causing ability by allowing the bacterium to evade the host's immune system and help in colonization and invasion of host tissues. Prevention: Hib vaccine provides protection against this bacteria. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  17 Neisseria Meningitis, Meningococcal Meningitis Neisseria meningitidis are Gram-negative aerobic cocci bacteria that are surrounded by a capsule. N. meningitidis are bacteria that can live in the back of the nose and throat. Approximately 10% of people are healthy nasopharyngeal carriers. Age Group: Children younger than 1 year and adults 65 years and older are at increased risk. Transmission: Neisseria meningitidis are transmitted from one person to another by sharing respiratory and throat secretions (saliva or spit). Prevention: Vaccine can help protect against some serotypes of Neisseria meningitidis Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  18 Streptococcus pneumoniae Meningitis, Pneumococcal Pneumonia Streptococcus pneumoniae are Gram-positive diplococci. About 70% of people are healthy nasopharyngeal carriers. Age Group: Most common in children (1 month to 4 years). Mortality: 30% in children, 80% in elderly Prevention: Pneumococcal conjugate vaccine (PCV13) and pneumococcal polysaccharide vaccine (PPSV23) provide effective protection. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  19 Listeriosis Listeria monocytogenes are Gram-positive aerobic rod- shaped bacteria. Pregnant and newborns, adults aged 65 or older, and people with weakened immune systems are at increased risk. Transmission: a) Usually foodborne (contaminated dairy, meat, or produce) b) Can be transmitted to fetus (maternal-fetal infection) Pathogenesis: Reproduces in phagocytes, allowing for intracellular survival. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Tetanus 20 The causative agent is Clostridium tetani, a Gram-positive, endospore-forming, obligate anaerobe bacteria. Tetanus is a serious disease of the nervous system leading to muscle contraction particularly of jaw and neck. The bacteria produces a toxin; Tetanospasmin, which blocks the relaxation pathway in muscles. Prevention: Vaccination with tetanus toxoid (included in DTP vaccines) and booster shots (dT). Treatment: With tetanus immune globulin Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Botulism Stop the massage of neurons Only live without oxygen 21 Clostridium botulinum is a Gram-positive, endospore-forming, obligate anaerobe bacteria. Botulinal toxin blocks the release of neurotransmitter neuromuscular junctions, leading to flaccid paralysis. Types of Botulism: a) Foodborne Botulism: Results from ingesting food contaminated with botulinum toxin. b) Infant Botulism: Occurs when infants ingest spores that germinate in the intestines and produce toxin. c) Wound Botulism: Caused by the growth of C. botulinum in a wound, leading to toxin production. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Botulism. 22 Signs & Symptoms Difficulty swallowing, Double and blurred vision, Drooping eyelids, Slurred speech, Muscle weakness, Difficulty in breathing. Treatment: Botulism antitoxin to neutralize circulating toxins. Antibiotics to eliminate bacteria from the intestines in infant botulism Prevention: Proper canning techniques, including adequate heat treatment and pH control, to prevent spore germination and toxin production in canned foods Use of nitrites/nitrates in processed meats to inhibit endospore germination. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Leprosy Acid- fast bacteria 23 Mycobacterium leprae is an acid-fast rod-shaped bacterium causes leprosy. All parts of bosy except CNS It primarily grows within peripheral nerves and skin cells. ‫من خالل لفترات طويلة‬ Transmission typically occurs through prolonged, close contact with an infected individual. There are two forms of leprosy: a) Tuberculoid (neural) leprosy: Characterized by skin lesions and a loss of sensation in affected areas. The lepromin test is typically positive in individuals with this form. b) Lepromatous (progressive) leprosy: Marked by the presence of disfiguring nodules all over the body. Individuals with this form usually test negative on the lepromin test. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Types of Leprosy 24 lepromin test lepromin test Appear of skin patches Body loss it shape and get change ,loss of fingers Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Poliomyelitis 25 Poliomyelitis is caused by the poliovirus, which is primarily transmitted through ingestion of contaminated food or water. The initial symptoms of poliovirus infection can include a sore throat and nausea. The virus can enter the bloodstream (viremia) and, if persistent, can invade the central nervous system (CNS), leading to the destruction of motor cells and paralysis. However, paralysis occurs in less than 1% of polio cases. Kill and damage the neurons Prevention of poliomyelitis is primarily achieved through vaccination, typically using an enhanced-inactivated polio vaccine (eIPV). Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Rabies 26 Rabies is caused by the rabies virus, a member of the Rhabdovirus family. The virus is primarily transmitted to humans through the bite of an infected animal. After entering the body, the virus multiplies in skeletal muscles near the site of the bite before spreading to the central nervous system (CNS), Inflamm…of brian where it causes inflammation of the brain (encephalitis). Initial symptoms of rabies in humans can include fever, headache, and a general feeling of illness. As the disease progresses, more specific symptoms such as‫هلوسة‬ agitation, hallucinations, hydrophobia (fear of water) may develop. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Rabies 27 Not expore the disease but for protection Prevention of rabies includes Ex:working with animals pre-exposure prophylaxis, which involves vaccination with the human diploid cell vaccine (HDCV) for individuals at high risk of exposure. Post-exposure treatment involves a combination of the rabies vaccine and rabies immune globulin (RIG) administered as soon as possible after exposure to the virus. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Arboviral Encephalitis 28 Arboviral encephalitis refers to a group of viral infections that cause inflammation of the brain (encephalitis). These viruses are transmitted to humans by arthropods, such as mosquitoes and ticks. Prevention of arboviral encephalitis primarily involves Ex:by killingcontrolling them the arthropod vectors that transmit the viruses. Vaccines are available for some arboviruses, such as Japanese encephalitis virus, but not for all. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Circular fungus Cryptococcus neoformans 29 Cryptococcus neoformans is a fungus commonly found in soil, particularly in association with pigeon and chicken droppings. The fungus is typically transmitted to humans through the respiratory route, primarily via inhalation of fungal spores. Once in the body, the fungus can spread through the bloodstream to the CNS, where it can cause cryptococcal meningitis. Cryptococcal meningitis is a severe condition with a mortality rate of up to 30% in untreated cases. Treatment for cryptococcal meningitis includes a combination of antifungal medications, such as Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk amphotericin B and flucytosine, Aktive Grotesk  African Trypanosomiasis 30 African trypanosomiasis, also known as sleeping sickness. Type of protozoan Caused by the protozoan parasites Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense. T. b. gambiense infection is the chronic form of African trypanosomiasis, lasting 2 to 4 years if untreated. T. b. rhodesiense infection is more acute, progressing rapidly over a few months. Transmission: Transmitted from infected animals to humans through the bite of the tsetse fly. Treatment: Eflornithine is a medication used to treat T. b. gambiense infection; it works by blocking an enzyme necessary for the parasite's survival. That’s why there is. No vacctination to this type The parasite's ability to evade the host's immune Becouse itsystem keep onthrough changingantigenic the antigens variation, where it alters its surface proteins to avoid recognition by antibodies. This makes the development of effective vaccines and Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk treatments more difficult. Aktive Grotesk  Naegleria fowleri 31 Naegleria fowleri is a free-living amoeba found in freshwater and causes a rare but severe brain infection called primary amebic meningoencephalitis (PAM). Infection occurs when contaminated water enters the body through the nose, typically during activities such as swimming. The amoeba then travels along the olfactory nerve to the brain, causing inflammation and destruction of brain tissue. Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk  Transmissible Spongiform Encephalopathies 32 Protiens molucle that couse disease (TSEs) TSEs are a group of fatal neurodegenerative disorders caused by abnormal prion proteins that affect humans and animals. Prion go and act in our brain system Prions are misfolded proteins that can convert normal proteins into abnormal forms, leading to brain damage and characteristic spongiform changes. TSEs can be transmitted through ingestion of contaminated meat, transplantation of infected tissues, or inheritance of mutated prion proteins. Types of TSEs: Sheep scrapie Creutzfeldt-Jakob disease Kuru Bovine spongiform encephalopathy Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Aktive Grotesk Thank You