Lecture 5 Flashcards by Unknown Unknown

Gram +ve Spore forming rods consist of…

Clostridium and Bacillus

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What causes disease in spore forming rods

release of exotoxins

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What is the causitvate agent of anthrax

Bacilius anthracis

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What is UNIQUE about Bacilius anthracis

Its protein capsules that are antiphagocytic

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Tell me about Bacilius anthracis spores

Very stable spores, resistant to heat, UV,drying, disenfectants

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How are human usually exposed to Bacillus anthracis spores

through contact with animals or soil

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What bacteria is used for bio-terrorism and warfare

Bacillus anthracis

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What are the 3 exotoxins found in Bacillus anthracis

1) lethal factor
2)protective antigen
3)Edema factor

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What does Bacillus anthracis PXO1 plasmid encode?

Bacillus anthracis exotoxins

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What does Bacillus anthracis PXO2 plasmid encode?

capsule genes

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What is the treatment for Bacillus anthracis?

Antibiotics: penicillin, doxycylin
Vaccine: available against Protective antigen protein

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What does Bacillus cereus do?

➢Causes food poisoning when spores enter food product

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What types of enterotoxins are found in Bacillus cereus

i)Heat labile: nausea, abdominal pain, diarrhea. Lasts 12-24hrs
(ii) Heat stable: SEVERE nausea and vomiting, short incubation

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How is Bacillus cereus treated?

antibiotic treatment usless…resistant to penicillin

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What is difference between clostridium and Bacillus

-Clostridium is anaerobic
-bacillis is aerobic

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What does Clostridium botulinum do?

Neurotoxin blocks Ach release in autonomic system; flaccid
muscle paralysis:

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What is the treatment for clostridium botulinum?

antitoxin and respiratory assistance

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Clostridium tetani caused by?

Rusty nail contaminated with spores punctures
skin; wound provides anaerobic environment

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What is the exotoxin of Clostridium tetani

tetanospasmin

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What does tetnus cause the body to react?

-sustained contraction fo skeletal muscles and severe muscle spasms

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Clostridium perfringens is also known as what and seen where?

Gas gangrene (seen in soldies wounded in battel)

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What are the 2 classes of infection found in Clostridium perfringens

1) wounded infection: necrotic skin with “crackly” poclets
2)Clostridial myonecrosis: exotoxin secretion dystoryos muscle thus black fluid excreeted from skin

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How is Clostridium perfringens treated?

treated with oxygen, antibiotics (penicillin) or amputation.

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what does Clostridium difficile cause?

antibiotic-associated
pseudomembranous colitis

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What is seen more commonly in hospitals than tetanus, anthrax or botulism

Clostridium difficile

How is Clostridium difficile caused?

Overuse of broad-spectrum antibiotics destroys normal intestinal flora

What does Clostridium difficile infect and release?

infects colon and releases exotoxins ➢Toxin A: diarrhea ➢Toxin B: cytotoxic to colon cells

What is treatment for Clostridium difficile

➢discontinue antibiotic treatment ➢Administer metronidazole or vancomycin

Clostridium difficile is treated by administration of metronidazole or vancomycin...What is different about these antibiotics ??

specifically target the bacteria responsible for the infection without affecting the entire gut microbiota as broadly as other antibiotics might

Gram +ve non spore forming rods include?

1) listeria monocytogenes 2)corynebacterium diptheriae

Where is Listeria monocytogenes found?

soft cheeses, unpasteurized milk, cold cuts

What is the problem with Listeria monocytogenes that makes it hard to get rid of

its PSYCHROPHILE...survives in refrigerator.

What type of bacteria is Listeria monocytogenes

➢ Facultative intracellular aerobe (prefer oxygen rich environment)

What does borderes does Listeria monocytogenes cross

blood brain, GI, feto-placental

What does Corynebacterium diptheriae colonize?

Colonization of pharynx and release of exotoxins into bloodstream

Corynebacterium diptheriae exotoxins damages what?

heart and neural cells

What is treatment of Corynebacterium diptheriae

Treatment (3 steps): (i) Antitoxin (ii) Penicillin or erythromycin (iii) DPT vaccine

What are the 4 types of gram -ve Bacilli (entrics)

1)Enterobacteriaceae 2)Vibrionaceae 3)Pseudomonadaceae 4)Bacterioidaceae

Organisms are divided into groups based on??

biochemical and antigenic properties

What is biochemical classification?

Ability to ferment lactose

What is EMB media?

Lactose fermenters are dark purple/black * Inhibits Gram positive bacteria

What is MacConkey Media:

* Lactose fermenters are pink-purple * Inhibits Gram positive bacteria

list 4 other types of Biochemical Classifications

1)H2S production 2)Hydrolysis of urea 3)Liquefy gelatin 4)Decarboxylation of amino acids

Classification Using Surface Antigens consists of?

Variable O antigen, K-antigen, H-antigen.

What is variable O antigen?

outermost layer of LPS common between enterics

What is K-antigen?

covers the O-antigen

What does H-antigen do?

flagellar sub-unit * Only in motile bacteria

list the 3 scenarios of disease cause by enterics?

1) Diarrhea-with/without systemic invasion 2) Diarrhea with intestinal cell invasion 3) Diarrhea with invasion of lymph nodes and bloodstream

1) Diarrhea-with/without systemic invasion

Bacteria bind intestinal cells but do not enter * EXOTOXIN release causes diarrhoea; ENTEROTOXIN causes fluid/electrolyte loss * Watery diarrhoea, NO FEVER * Vibrio cholera

2) Diarrhea with intestinal cell invasion

Bacterial virulence factors allow binding and invasion of cells * Toxin release destroys cells bloody stools * Fever response * Shigella,

3) Diarrhea with invasion of lymph nodes and bloodstream

Abdominal pain with diarrhoea containing white and red cells * Fever, headache, increased white cell counts * Salmonella Typhi, Yersinia enterocolitica, Campylobacter jejeuni

Salmonellae is member of what family?

Enterobacteriaceae

what are the 2 types of salmonella

S. enterica and S. bongori

What are two types of s.enterica?

Enterocolitis (tummy problems) and Typhoid (enteric) fever

Complete... thier are 2 types of entercolitis S. enterica serovar

1) S. enterica serovar Enteritidis 2)S. enterica serovar Typhimurium

Complete... thier are 2 types of Typhoid S. enterica serovar

1) S. enterica serovar Typhi 2) S. enterica serovar Paratyphi

How can someone get S. enterica serovar Enteritidis aka entercolitis?

Ingestion of contaminated food * Poultry, eggs, meat and milk

*enteric fever is?

generalized infection...bacterial multiplication in lymphoid tissue...Necrosis of intestinal lymphoid tissue ulceration, haemorrhage, perforation

if enteric fever is untreated what is the mortality?

10%

what term is used to refer to individuals who have recovered from an infectious disease but continue to harbor the causative microorganism within their bodies, have no symtpoms and have transmit it

Convalescent carriers:

How long is enteric fevers Convalescent carriers

3 months

chronic carriers of enteric fever?

are only 1-2% excrete bacteria for at least 6 months, sometimes life long.

What is the diagnosis for enteric fever during 1st and 2/3rd week

1st week: isolation of bacteria from blood 2-3rd week: stool and urine

Is thier treatment for enteric fever?

Vaccine available, but only effective against small bacterial load

What is Most numerous aerobic bacteria of normal gut flora

Escherichia coli

What notable symptoms does shigellae cause?

Cause acute diarrhoea with mucus, pus and blood

Difference between shigellae sonnei and shigellae dysenteriae

Shigella sonnei Europe and North America S. dysenteriae: tropics and severe

treatment for shigallae?

NO VACCINE

Campylobacter types?

C. jejuni and C. coli

Name the bacteria that can cause bloody diarrhea?

Shigallae and Campylobacter

Where are Pseudomonas found

mainly in moist habitats and water

what is treatment for Pseudomonas

Difficult to treat becuase ALL are ANTIBIOTIC RESISTANT

Pseudomonas aeruginosa

Respiratory pathogen in cystic fibrosis patients AND * Infections in lesions of burn patients

What is Common contaminant of saline solutions and water

Pseudomonas cepacia

What is Haemophilus influenzae bacteria normally apart of in the human body

nasopharyngeal flora i

What does nasopharyngeal flora cause

Meningitis, pneumonia, joint infections

What is linked to infant formula?

Cronobacter sakazakii

What is special about Helicobacter pylori

Microaerophillic and spiral bacilli

What does Helicobacter pylori cause

stomach ulcers

What does Urease do

gives protection form low pH

What is the treatment for Helicobacter pylori

triple therapy treatmnet: antibiotics and H+ pump inhibitors

What bacteria causes a CRAZY cough

Bordetella pertussis

What is prevention for Bordetella pertussis

vaccination with heat-killed organism

Lecture 5 Flashcards

Gram +V and Gran -V Bacilli (83 cards)