Bacteria Basics and Gram positive bacteria

What are the five major groups of bacteria

Gram positive (thick wall), Gram negative (thin wall + outer membrane), Spirochetes (spiral), Cyanobacteria (photosynthetic), Chlamydiae (intracellular)

How many bacterial phyla are currently identified

30 phyla that we can classify

How many bacterial phyla may exist

Possibly over 1000 that have not been identified yet

What are the 7 major bacterial phyla you need to know Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, Spirochetes, Cyanobacteria, Chlamydiae

Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, Spirochetes, Cyanobacteria, Chlamydia

What is the main structural difference between Gram-positive and Gram-negative bacteria - Gram-positive have thick peptidoglycan layers, Gram-negative have thin layers plus an outer membrane with endotoxin

Why are Gram-negative bacteria often more dangerous - Their outer membrane contains endotoxin (LPS) that triggers strong immune responses like fever and inflammation

What is an endospore and why is it important - A dormant, heat-resistant structure that allows bacteria to survive extreme conditions and reactivate later

Why are endospores clinically important - They make bacteria hard to kill with heat, disinfectants, and environmental stress

What are the key characteristics of Firmicutes - Gram-positive, thick wall, low G+C DNA, many form endospores for survival

What genus in Firmicutes is important for environmental survival - Bacillus (aerobic, soil bacteria, spore forming)

What are the oxygen requirements of Bacillus species - Mostly aerobic or facultative anaerobes (can live with or without oxygen)

What diseases are caused by Bacillus anthracis - Anthrax (cutaneous, inhalation, GI, meningitis)

What is Bacillus cereus associated with - Food poisoning, especially reheated rice

What genus includes obligate anaerobic, toxin-producing bacteria - Clostridium

What disease is caused by Clostridium tetani - Tetanus (muscle rigidity, lockjaw)

What disease is caused by Clostridium botulinum - Botulism (flaccid paralysis)

What disease is caused by Clostridium difficile - Pseudomembranous colitis after antibiotics

What do Lactobacillus and Lactococcus do - Produce lactic acid, used in food fermentation

What disease does Listeria monocytogenes cause - Meningitis, bacteremia, crosses placenta

What are the three main Gram-positive cocci genera - Staphylococcus, Streptococcus, Enterococcus

What test differentiates Staphylococcus from Streptococcus - Catalase test

What is the arrangement of Staphylococcus - Grape-like clusters

What is the arrangement of Streptococcus - Chains

What does a positive coagulase test indicate - Staphylococcus aureus (pathogenic)

What disease can follow Streptococcus pyogenes infection - Rheumatic fever

What is Streptococcus pneumoniae known for - Leading cause of bacterial pneumonia