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Jumpstart 4/9. Get a book from the cart (hint ch. 30 and 31) Answer the following questions: What bacteria causes gonorrhea? What bacteria causes bubonic plague?. Neisseria and Enterobacteraceae. Medical Microbiology Spring 2010. Neisseriaceae.
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Jumpstart 4/9 • Get a book from the cart (hint ch. 30 and 31) Answer the following questions: • What bacteria causes gonorrhea? • What bacteria causes bubonic plague?
Neisseria and Enterobacteraceae Medical Microbiology Spring 2010
Neisseriaceae • Family of bacteria with 4 genera, 2 are strictly pathogenic and the other 2 are normal flora—we are only going to look at 1 of them • Gram negative cocci, typically arranged in pairs (diplococcus)
Characteristics of Neisseria • Gram negative diplococcus • Do not form spores • Most are catalase positive too (makes it easy for laboratory detection) • Have pili that extend from the membrane • Allow attachment to hosts • Exchange of genetic material
Neisseria cont. • Pathogenic species need iron to grow and compete with their human hosts for iron. • The type that we will focus on is Neisseria gonorrhoeae
Virulence Factors • Pilin- attachment • Por protein- keeps them from being destroyed by the immune system easily • Opa protein- firm attachment • Rmp protein- protects surface antigens from being destroyed • 3 proteins for acquiring iron • LOS (lipooligosaccharide) endotoxin • An enzyme to destroy penicillin
Neisseria gonorrhoeae • Causes the disease gonorrhea • Occurs only in humans • 2nd only to chlamydia as the 2nd most commonly reported bacterial STD in the US • About 300,000 cases per year are reported • Highest incidence is in the age group 15-24 • Transmitted primarily by sexual contact
Only about half of infected women experience symptoms (other half are asymptomatic). Men almost always experience symptoms. • Chance of acquiring the infection if sexual contact with an infected person: • If female, 50% • If male, 20%
Gonorrhea • Signs and symptoms • Depends on the gender and location of the infection
Gonorrhea in males • Mostly restricted to the urethra • Purulent urethral discharge • Dysuria (painful urination) • Swelling of epididymis, prostate may occur
Gonorrhea in females • Primarily restricted to the cervix • Not able to infect the vagina • Signs and symptoms • Vaginal discharge • Dysuria • Abdominal pain • PID • Ovarian abcesses
Diagnosis • Swab infected area and do a gram stain • Oxidase/catalase postitive
Treatment • Penicillin was the drug of choice for years • You already know why not so much anymore (think about its virulence factors) • Also makes them resistant to erythromycin, tetracycline, aminoglycosides • In Asia and Pacific islands, we also see resistance to Cipro • Now, drug of choice is Azithromycin (Z-pac) or doxycycline
Enterobacteriaceae • You have 10 minutes to read and take notes on the structure and physiology of enterobacteriaceae
Group Time I sneakily wrote a number on your paper while you were taking notes. Get with your group. #1’s: E. coli #2’s Salmonella #3’s: Shigella #4’s:Yersinia (my fav) #5’s: Klebsiella #6’s: Treatment, Prevention, and Control
Jumpstart 4/13 • How can gonorrhea be treated? • Name 3 ways that Enterobacteriaceae is different from Neisseria.
E.coli • Escherichia coli • Capable of causing sepsis, UTIs, meningitis, gastroenteritis • 2 major virulence factors • Adhesins: allow it to stick cells and not be flushed away • Exotoxins
E. Coli • Large numbers of E. coli are found in the GI tract • Major cause of UTIs (80% of UTIs are caused by E.coli • Common cause of gastroenteritis in developing countries
Gastroenteritis (E. coli) • EPEC (enteropathogenic): • Small intestine, causes infant diarrhea; watery, nonbloody • ETEC (Enterotoxigenic): • Small intestine, “traveler’s diarrhea” and infant diarrhea; cramps, nausea, low-grade fever
Gastroenteritis, cont • EHEC (Enterohemorrhagic) • Large intestine; bloody diarrhea, no fever • EIEC (Enteroinvasive) • Large intestine; watery diarrhea, may progress to dysentery with bloody stool • EAEC (Enteroaggregative) • Small intestine, infant/traveler’s, persistent
Salmonella • Ingested and travel to the stomach where they can survive the harsh conditions • Colonizes nearly all animals • Most infections result from infected foods (fecal/oral) • Most notorious species is Salmonella typhii
Salmonella, cont. • Gastroenteritis • Septicemia • Enteric fever (typhoid) • Malaise, fever, headache, gastrointestinal problems
Shigella • Common cause of dysentery (S. dysenteriae) • Exotoxin called Shiga toxin that disrupts protein synthesis and damages endothelial cells • Causes shigellosis • Abdominal cramps, diarrhea, fever, bloody stools
Yersinia Read the information provided and answer the following questions: • Between 1347 and 1351, how many people died from bubonic plague? • What is the main source of Y. pestis? • Describe how a bite from this organism may lead to the plague. • Describe several impacts of the Black Plague. • Should we be concerned with the plague returning? Why or why not? • Create a mini-timeline on your notebook paper to represent the history of the plague.
Klebsiella • Prominent capsule • Can cause pneumonia
Treatment • Some infections do not require antibiotic treatment, just treat symptomatically. • E. coli and Salmonella infections can be prolonged by antibiotic use • For other infections, streptomycin