Welcome to Pathogen Group 9
• Yersinia pestis • Francisella tularensis • Borrelia burgdorferi • Rickettsia rickettsii • Rickettsia prowazekii • Acinetobacter baumannii Yersinia pestis: Plague
• gram negative oval bacillus, bipolar staining • Entero- bacteriaceae • Aerobic or facultatively anaerobic • No capsule • Nonmotile Plague
• reservoir: rodents vector: fleas
• bubonic plague: bubos, fever, chills, headache, malaise, prostration, petechial rash • plague pneumonia
• pneumonic plague blocked spiny valve in flea causes regurgitation during bite plague areas: U. S. Plague in world History of Plague Pandemics
• 6th Century: killed 100 million Europeans • 14th Century: killed 44 million Europeans • 20th Century: killed ?? Million in China Plague cases per year, U.S. plague transmission plague transmission Francisella tularensis: Tularemia
• reservoirs: rabbits, other animals, ticks (transovarian transmission in ticks) • oval gram - bacilli • bipolar staining • Strictly aerobic (Tortora is wrong) • Capsule • Requires enriched media (cysteine added) • Highly virulent: ID as low as 10 cells • many modes of transmission Transmission of tularemia
• Bite of tick or deer fly • Through inhalation (occupational hazard for gardeners: dust from rodent feces) • Through ingestion • Through skin contact • Splash into eye forms of tularemia
• ulceroglandular = skin ulcer and lymphaden- opathy • glandular with no ulcer • ocular • intestinal - pain, vomiting, diarrhea • pneumonic • typhoidal (systemic) tularemia
• primary lesion (ulcer) Tularemia in U.S. Tularemia as bioterrorist weapon
• Considered ideal: many methods of transmission, especially airborne Borrelia burgdorferi : Lyme disease
• spirochete • reservoir: mice and deer • Also affects dogs, cows, horses • vector: ticks • affects skin, joints, nervous system, and cardiovascular system Increase in Lyme disease Counties with Lyme disease
symptoms of Lyme disease
• Estimated 5-40% of human infections symptomatic • initial rash (most reliable symptom) • rash usually accompanied by fatigue, fever, headache, stiff neck, arthralgia or myalgia (all are often intermittent) • Late symptoms: arthritis meningitis, cranial neuritis, facial palsy disorders of heartbeat Lyme disease
• bullseye rash around site of tick bite Lyme reservoir and vector Lyme disease reservoir and vector Lyme transmission to human Lyme prevention
• LYMErix vaccine: no longer manufactured • avoid tick bites, remove ticks promptly Rickettsia rickettsii: Rocky Mountain Spotted Fever • vector: ticks symptoms of RMSF
• fever • myalgia, headache, petechial rash (usually on palms of hands and soles of feet), vomiting, fever, lethargy • Potentially fatal without prompt treatment with antibiotic (doxycycline) • 90% of cases April-Sept
RMSF rash on hands and abdomen • transovarian transmission in ticks QuickTime™ and a Photo - JPEG decompressor are needed to see this picture.
• RMS fever damage to a person RMS fever: fatal case with gangrene Rickettsia prowazekii: Epidemic Typhus Fever • vector: lice (s. louse) • fever, chills, headache, prostration, general pains, red rash on 5th day spreads over whole body • can be fatal • may reoccur years later Acinetobacter baumannii
• Aerobic, opportunistic, gram-negative coccobacillary rod • There have been many reports of A. baumannii infections among American soldiers wounded in Iraq, earning it the nickname "Iraqibacter".[3] • Multi-drug resistant Acinetobacter baumannii is abbreviated as MDRAB. Multidrug-resistant Acinetobacter is not a new phenomenon; it has always been inherently resistant to multiple antibiotics. • In soil and water • Normally inhabits skin, mucous membranes and soil Acinetobacter baumannii
• Genus Acinetobacter is important opportunistic pathogens in hospital-acquired infections. They cause various types of human infections, including pneumonia, wound infections, urinary tract infections, bacteremia, and meningitis. Of the currently known 31 Acinetobacter species, Acinetobacter baumannii is the most prevalent in clinical specimens. Adherence of bacteria to epithelial cells is an essential step towards colonization and infection. Bacterial adherence to host cells is mediated by fimbria or membrane components. Furthermore, many pathogenic bacteria are capable of invading non-phagocytic cells and evolve to survive within the host cells. The cellular invasion of bacteria contributes to evasion of humoral immunity, persistence in the host, and penetration into deep tissues.