Exam 4 (Micro) pt.2

Aerobic gram-negative rods

A group of non-enteric bacteria that are predominantly opportunistic, zoonotic, or primary pathogens, known for their unique lipopolysaccharide outer membrane.

Lipopolysaccharide Outer Membrane

A distinctive layer in the cell walls of gram-negative bacteria that produces endotoxins, eliciting immune responses.

Opportunistic Pathogens

Microorganisms that can cause disease when the host's immune system is compromised.

Pseudomonas spp.

A genus of small, free-living gram-negative rods effective in bioremediation, characterized by aerobic respiration and antibiotic resistance.

Pseudomonas aeruginosa

An opportunistic pathogen responsible for nosocomial infections in immunocompromised patients, including UTIs and pneumonia.

Burkholderia spp.

A genus that includes species used in bioremediation and can cause lung infections, particularly in cystic fibrosis patients.

Acinetobacter baumannii

A gram-negative bacterium increasingly linked to nosocomial infections and known for its resistance to multiple antibiotics.

Stenotrophomonas maltophilia

An opportunistic pathogen associated with severe respiratory conditions in immunocompromised individuals, known for multi-drug resistance.

Francisella tularensis

The bacterium causing tularemia, associated with wild rabbits and various insects, with potential transmission routes including contact and inhalation.

Bordetella pertussis

The primary causative agent of whooping cough, highly contagious and particularly dangerous for infants and young children.

Legionella pneumophila

The bacterium responsible for legionellosis, historically linked to outbreaks such as the one at the American Legion convention in 1976.

Facultative Anaerobes

Bacteria that can grow in both aerobic and anaerobic conditions, allowing them to ferment glucose and other sugars.

Coliforms

Lactose-fermenting bacteria that indicate fecal contamination, commonly used to assess water safety.

Escherichia coli (E. coli)

The most common enteric bacillus, some strains of which can cause severe disease including hemorrhagic colitis.

Klebsiella pneumoniae

A bacterium prevalent in the respiratory tract, causing pneumonia and urinary tract infections due to antibiotic resistance.

Salmonella spp.

Bacteria that cause severe gastrointestinal diseases and include Salmonella typhi, the cause of typhoid fever.

Shigella spp.

Bacteria that cause dysentery characterized by severe diarrhea, often exacerbated by poor sanitation.

Proteus spp.

A genus of bacteria found in soil and the human body that can become opportunistic, leading to infections.

Yersinia enterocolitica

A species associated with animals that can cause ileitis, mimicking appendicitis and complicating diagnosis.

Endotoxins

Toxins produced by certain bacteria that can trigger strong immune responses.

Clinical Relevance of Pseudomonas

Notorious for causing infections in patients with burns or cystic fibrosis, leading to various complications.

Transmission Routes for Francisella

Can be transmitted through contact with infected animals, inhalation, ingestion, or bites from infected vectors.

Pathophysiology of Bordetella pertussis

Infection leads to ciliated cell destruction, impairing mucociliary clearance and resulting in mucus accumulation.

Vaccine for Bordetella pertussis

An acellular vaccine (DTaP) that stimulates an immune response against whooping cough without using live organisms.

Outbreak History of Legionella pneumophila

Identified during the outbreak at the American Legion convention in 1976, leading to significant illness and fatalities.

Rapid Molecular Methods

Advanced diagnostic techniques used for the quick identification of pathogens, although traditional cultures are more cost-effective.

Diagnostic Testing for Enteric Bacteria

Involves the use of selective media to culture bacteria and observe biochemical reactions indicative of specific genera.

Immune Responses to Endotoxins

Endotoxins induce responses that can lead to fever, inflammation, and septic shock.

Nosocomial Infections

Infections acquired in a hospital setting, often caused by opportunistic pathogens.

Multidrug Resistance

The ability of bacteria to resist multiple antibiotics, complicating treatment options.

Environmental Reservoirs for Legionella

Typically found in warm water environments, becoming problematic when aerosolized.

Klebsiella pneumoniae Infections

Associated with nosocomial pneumonia, often stemming from its polysaccharide capsule enabling evasion of the immune response.

Asymptomatic Carriers of Salmonella

Individuals who carry the bacteria without showing symptoms, complicating infection control efforts.

Mucociliary Clearance Mechanism

The process that helps trap and remove pathogens from the respiratory tract, impaired by Bordetella infection.

Gastrointestinal Disease from Enteric Bacteria

Caused by specific strains of E. coli, Salmonella, and Shigella due to high fecal contamination.

Bioassays in Bacterial Identification

Tests conducted in test tubes after culture incubation to analyze bacterial types based on biochemical reactions.

Antigenic Structures of Pathogenic Bacteria

H, K, and O antigens are used to characterize and identify bacteria, playing a role in immune response.

High-Risk Occupations for Tularemia

Occupations involving potential exposure to infected animals or contaminated environments due to the risk of tularemia.

Severe Conditions Linked to Stenotrophomonas maltophilia

Associated with respiratory illnesses in patients with compromised immune systems.

Environmental Cleanup with Pseudomonas spp.

Utilized in bioremediation efforts due to the ability to utilize a variety of organic materials.

Causative Agents of Gastrointestinal Infections

Include Salmonella and Shigella spp., which can lead to severe disease and outbreaks.

Bacterial Resistance Mechanisms

Include structural modifications and efflux pumps that help bacteria survive antibiotic treatment.

Clinical Implications of E. coli O157:H7

Can lead to severe disease outcomes such as hemorrhagic colitis and acute kidney failure.

Quality Indicator in Water Supplies

E. coli counts are used to assess fecal contamination and water safety.

Opportunistic Infections in Immunocompromised Patients

Infections caused by normally non-pathogenic bacteria that take advantage of weakened immune systems.

Vaccine Recommendations for Francisella tularensis

Recommended primarily for individuals in high-risk jobs due to its potential as a bioterrorism agent.

Biohazard Risk of Processing Rabbit Carcasses

High risk due to potential exposure to bioaerosols from infected animals.

Characteristics of Aerobic Gram-Negative Rods

Small, non-spore forming bacteria categorized as pathogens or opportunistic, with environmental versatility.

Plasmid-Mediated Resistance

A form of resistance in bacteria where resistance genes are carried on plasmids, contributing to multi-drug resistance.

Morbidity Associated with Acinetobacter Infections

Can lead to severe complications in patients with underlying health conditions.

Resistance of Proteus spp.

Often becomes opportunistic following antibiotic treatments leading to infections.

Community Reservoirs for Legionella

Present in human-made water systems, posing infectious risks when inhaled.

Multidrug Resistance Implication

Makes treatment of infections complex and often requires careful selection of antibiotics.

Infections Caused by Enterobacter spp.

Notable for urinary tract infections and post-surgical complications.

Immune Evasion via Polysaccharide Capsule

Klebsiella pneumoniae uses its capsule to resist phagocytosis and evade immune responses.

Clinical Features of Tularemia

Symptoms include severe illness such as headaches, fever, and chills, potentially leading to high mortality.

Antibiotics and Enteric Infections

Antibiotics may be warranted for severe cases, but abused can lead to resistance issues.

Understanding Anaerobic vs. Aerobic Bacteria

Crucial for different treatment and management strategies in infectious diseases.

Cystic Fibrosis and Burkholderia spp.

Certain species of Burkholderia cause lung infections in cystic fibrosis patients, highlighting their pathogenicity.