BMSC210 CH4.2 Flashcards
How many classes are the Proteobacteria divided into?
Five
Alphaproteobacteria
Betaproteobacteria
Gammaproteobacteria
Deltaproteobacteria
Epsilonproteobacteria
What is the first class of Proteobacteria?
Alphaproteobacteria
What is the unifying characteristic of Alphaproteobacteria?
They are oligotrophs
What do oligotrophs rely on for their energy needs?
Cells
What are elementary bodies?
Endospore-like form of intracellular bacteria
What is the relationship between Rhizobium and legume roots?
Symbiotic relationship
What type of nutrients do Betaproteobacteria require?
organic nutrients
Where do Betaproteobacteria often grow?
between aerobic and anaerobic areas
Are some genera of Betaproteobacteria human pathogens?
Yes
What is quorum sensing?
Density-dependent communication in bacteria
Why is quorum sensing important for bacterial populations?
Delay activation of specific genes until advantageous
What is Enterobacteriaceae?
Family of enteric bacteria
What are the two categories within Enterobacteriaceae?
Coliforms and non-coliforms
What is the prototypical bacterium species of coliforms?
Escherichia coli
What is the second category of bacteria that cannot ferment lactose or can only ferment it incompletely?
Noncoliforms
Name some notable human pathogens that are noncoliforms.
Salmonella spp., Shigella spp., Yersinia pestis
What is the potentially deadly toxin produced by some strains of E. coli?
Shiga toxin
What are serotypes?
Strains or variations of the same species of bacteria
How are serotypes classified?
Based on patterns of reactivity by animal antisera against molecules on the surface of the bacterial cells
What are the unique characteristics of Escherichia?
Inhabit the gastrointestinal tract of warm-blooded animals
Are most sulphate-reducing bacteria pathogenic?
No, few of them are pathogenic
What is the smallest class of Proteobacteria?
Epsilonproteobacteria
What are the characteristics of Epsilonproteobacteria?
Gram-negative and microaerophilic
What diseases can be caused by Campylobacter?
Food poisoning and severe enteritis
What is the common cause of chronic gastritis and ulcers of the stomach and duodenum?
H. pylori
What is a common cause of inflammation in the small intestine?
C. jejuni
How is C. jejuni usually transmitted to humans?
Eating contaminated poultry products
What is H. pylori linked to?
Stomach cancer
How is H. pylori able to survive in the stomach?
It produces urease and other enzymes that modify its environment to make it less acidic
What are the unique characteristics of the Epsilonproteobacteria class?
Gram-negative, spiral-shaped rod; aerobic (microaerophilic)
What are the unique characteristics of the Campylobacter genus?
Gram-negative, spiral-shaped rod; often infects chickens; may infect humans via undercooked meat, causing severe enteritis
What are the unique characteristics of the Helicobacter genus?
Gram-negative, spiral-shaped rod; aerobic (microaerophilic) bacterium; can damage the inner lining of the stomach, causing chronic gastritis, peptic ulcers, and stomach cancer
