Toxin Information and Courses from MediaLab, Inc.

These are the MediaLab courses that cover Toxin and links to relevant pages within the course.

Learn more about laboratory continuing education for medical technologists to earn CE credit for AMT, ASCP, NCA, and state license renewal and recertification. Or get information about laboratory safety and compliance courses that deliver cost-effective OSHA safety training and continuing education to your laboratory's employees.

Current Topics in Clinical Microbiology
Review 2 Tuomanen EI.: Pathogenesis of pneumococcal inflammation: otitis media Vaccine. 19 Suppl 1:S38-40, 2000Pneumococci cause damage to the ear in otitis media with an association with bacterial meningitis. The pathogenesis of injury involves host response to cell wall constituents and the pore-forming toxin, pneumolysin.Release of cell wall constituents, particularly during antibiotic-induced bacterial lysis, leads to an influx of leukocytes and subsequent tissue injury. The signal transduction cascade for this response is becoming defined and includes CD14, Toll-like receptor 2, NFkB, and cytokine production.The second source of injury is the cytotoxicity of the pore forming toxin, pneumolysin.Decreasing the sequelae of otitis can be achieved by an increased understanding of the site-specific mechanisms of pneumococcal-induced inflammation.	View Page
Review 1 Garbutt JM. Littenberg B. Evanoff BA. Sahm D. Mundy LM. Enteric carriage of vancomycin-resistant Enterococcus faecium in patients tested for Clostridium difficile. Infection Control & Hospital Epidemiology. 20(10):664-70, 1999OBJECTIVE: To identify independent risk factors for enteric carriage of vancomycin-resistant Enterococcus faecium (VREF) in hospitalized patients tested for Clostridium difficile toxin.PATIENTS: Convenience sample of 215 adult inpatients who had stool tested for C. difficile between January 29 and February 25, 1996.RESULTS: 41 (19%) of 215 patients had enteric carriage of VREF. Five independent risk factors for enteric VREF were identified: (1) history of prior C. difficile infection, (2) parenteral treatment with vancomycin for > or = 5 days, (3) treatment with antimicrobials effective against gram-negative organisms, (4) admission from another institution, and (5) age > 60 years. These risk factors for enteric VREF were independent of the patient's current C. difficile status.CONCLUSIONS: Antimicrobial exposures are the most important modifiable independent risk factors for enteric carriage of VREF in hospitalized patients tested for C. difficile.	View Page
Case History A 63 year old man was seen in the emergency room with the complaints of sudden onset of fever, chills, and abdominal pain, accompanied by mild diarrhea. The blood pressure was 140/84, the pulse rate 82/minute, and the body temperature 39.8C. A blood sample was drawn for a complete blood count, and a blood culture.A second blood culture was drawn from the opposite arm, with 10 ml of blood being placed into each an aerobic and an anaerobic bottle, following customary practice.The complete blood count revealed a hemoglobin of 15.8 mg/dl, a hematocrit of 45%, and a white blood count of 4.2/L. The neutrophils were 39%, lymphocytes 45%, monocytes 10%, eosinophils 4% and basophils 2%. The platelet count was 255/L. The patient was admitted to the hospital for further work-up and empiric antibiotic therapy.Within 24 hours after admission, the body temperature had decreased to 38.2C, although the mild diarrhea persisted.A stool toxin test for Clostridium difficile was negative and neither enteric pathogens nor Campylobacter species were recovered in stool culture after 24 hours incubation. Fecal neutrophils were not seen on direct examination. The anaerobic blood culture became positive 36 hours after inoculation.	View Page
Review 3 Ladhani S. Joannou CL. Lochrie DP. Evans RW. Poston SM.: Clinical, microbial, and biochemical aspects of the exfoliative toxins causing staphylococcal scalded-skin syndrome. Clinical Microbiology Reviews. 12:224-242, 1999The exfoliative (epidermolytic) toxins of Staphylococcus aureus are the causative agents of the staphylococcal scalded-skin syndrome (SSSS), a blistering skin disorder that predominantly affects children. Clinical features of SSSS vary along a spectrum, ranging from a few localized blisters to generalized exfoliation covering almost the entire body.The toxins act specifically at the zona granulosa of the epidermis to produce the characteristic exfoliation, although the mechanism by which this is achieved is still poorly understood.Despite the availability of antibiotics, SSSS carries a significant mortality rate, particularly among neonates with secondary complications of epidermal loss and among adults with underlying diseases.	View Page
The staphylococcal toxins causing the scalded skin syndrome (SSSS) have as their site of action in which of the following layers of skin:	View Page

Introduction to Bioterrorism
Biological Agents Biological agents are organisms or toxins that can kill or incapacitate people, live stock, and crops. The three basic groups of biological agents that would likely be used as weapons are bacteria, viruses, and toxins. Biological agents can be dispersed as aerosols or airborne particles.	View Page
Category A Agents Category A agents include: Smallpox (variola major) Anthrax (Bacillus anthracis) Plague (Yersinia pestis) Botulism (Clostridium botulinum toxin) Tularaemia (Francisella tularensis) Ebola hemorrhagic fever Marburghemorrhagic fever Lassa fever Argentine hemorrhagic fever	View Page
Category B Agents Category B agents include: Q Fever (Coxiella burnetii) Brucellosis (Brucella sp.) Glanders (Burkholderia mallei) Venezuelan encephalomyelitis Eastern and western equine encephalomyelitis Ricin toxin from castor beans (Ricinus communis) Epsilon toxin of Clostridium perfringens Staphylococcus enterotoxin B	View Page
Agent: Botulism (bacterium) Most likely means of dissemination: Aerosol (eating contaminated food)Primary route of entry: Inhalation (oral)General signs and symptoms: Difficulty with speaking, swallowing, or blurred or double vision, drooping eyelids (ptosis), dilated pupils, dry mouth, decreased gag reflex, weakening of the reflexes (hyporeflexia), abnormal sensations such as numbness, prickling, tingling, and arm or leg weakness.Botulism is caused by a neurotoxin and technically could be classified as a chemical WMD. For our discussion it is placed under biological agents because the toxin is derived from a bacterium. Botulism is potentially life-threatening, producing a characteristic clinical picture of muscular paralysis leading to respiratory failure. Photo courtesy of the CDC archives.	View Page
Types of Chemical Agents There are four primary agents that could possible be used in a chemical attack: Lung-damaging or choking agents Blood agents Blister agents Nerve agentsOthers that might be used include: incapacitating agents, riot-control agents, heavy metals, volatile toxins, pesticides, dioxins, explosive nitro compounds and oxidizers, flammable industrial gases and liquids, plus corrosive industrial acids and bases.	View Page
What if: Biological Attack Biological attacks involve bacteria, viruses or natural toxins. The effects of toxins can be immediate but for bacteria and viruses the effects may not be apparent for weeks. A bio-terrorist may attack by infecting animals, contaminating food and water, spraying bacteria or viruses into the air. In infections such as smallpox and plague, once a few individuals are infected they can further spread the disease from person to person. An attack could also come from through a building’s ventilation system, the mail, or even through exposure to an infected terrorist seeking to spread disease during an infectious stage.	View Page

Phlebotomy
Plasma drugs and toxins Drugs and toxins including therapeutic drugs and drugs of abuse may be present in the plasma. Other substances too numerous to mention are also present in plasma.	View Page
Plasma components Plasma is the liquid portion of the blood. It contains many substances including:Water Electrolytes Sugars Proteins Lipids Drugs & Toxins	View Page