Aeromonas Clinical Manifestations Quiz

Questions and Answers

What is a common characteristic of Aeromonas in terms of its clinical manifestations?

Is nonmotile and grows only in anaerobic conditions

Is exclusively linked to respiratory infections

Produces enterotoxins linked to diarrheal disease (correct)

Causes only extraintestinal infections

Which method is suggested for the laboratory diagnosis of Aeromonas spp.?

Isolation of an oxidase-negative, Gram-negative cocci

Isolation of a fermenting, oxidase-positive, Gram-negative bacillus (correct)

Isolation of a spore-forming, non-motile bacillus

Isolation of a non-fermenting, Gram-positive bacillus

Which of the following antibiotics is Aeromonas spp. resistant to?

Trimethoprim-sulfamethoxazole

Aminoglycosides

First-generation cephalosporins (correct)

Quinolones

What is the optimal growth condition for Campylobacter jejuni?

An atmosphere containing 5-10% oxygen Signup and view all the answers

What is a recognized complication associated with Campylobacter jejuni infections?

Guillain–Barré syndrome Signup and view all the answers

What is a common clinical manifestation of Pseudomonas aeruginosa infection?

Pulmonary infection in cystic fibrosis patients Signup and view all the answers

Which method is effective for the laboratory diagnosis of Plesiomonas shigelloides?

HE agar and other nonselective media Signup and view all the answers

Which characteristic is NOT associated with the Enterobacteriaceae family?

Strictly aerobic metabolism Signup and view all the answers

What is one of the antimicrobial susceptibilities of Plesiomonas shigelloides?

Susceptible to third-generation cephalosporins Signup and view all the answers

What condition can Pseudomonas aeruginosa most seriously affect?

Patients with cystic fibrosis and burn injuries Signup and view all the answers

Study Notes

Plesiomonas

Plesiomonas shigelloides: facultatively anaerobic, Gram-negative rod that is oxidase- and catalase-positive, ferments glucose.
Found in aquatic environments, limited by a minimum growth temperature of 8°C.
Causes gastroenteritis, especially from consuming uncooked shellfish; can lead to extraintestinal infections like meningitis and septicemia.
Laboratory Diagnosis: Isolated using nonselective and enteric-selective media (e.g., HE agar); indole-positive, methyl-red-positive, reduces nitrates, and ferments glucose, maltose, and trehalose.
Antimicrobial Susceptibility: Susceptible to cephalosporins, trimethoprim–sulfamethoxazole, imipenem, and quinolones.

Pseudomonas

Strictly aerobic, catalase-positive, oxidase-positive, and Gram-negative bacilli with respiratory metabolism.
Commonly associated with pulmonary infections in cystic fibrosis patients and severe infections in burn and trauma patients.
Motility through polar flagella; capable of forming acids and reducing nitrates.

Aeromonas

Found in aquatic environments, associated with intestinal and extraintestinal diseases.
Some strains produce enterotoxins, hemolysin, and a cytopathic factor.
Laboratory Diagnosis: Isolation of a fermenting, oxidase-positive, Gram-negative bacillus should raise suspicion for Aeromonas spp.
Antimicrobial Susceptibility: Susceptible to quinolones, aminoglycosides, carbapenems, and trimethoprim–sulfamethoxazole; produces β-lactamase conferring resistance to penicillins and first-generation cephalosporins.

Campylobacter

Small, motile, non-spore-forming, Gram-negative bacilli that are microaerophilic (optimal growth in 5-10% O2).
C. jejuni: Most common cause of bacterial enteritis in the U.S., linked to improperly cooked poultry; diarrhea may be bloody and self-limited, lasting up to a week.
Can result in extraintestinal infections and is a recognized antecedent of Guillain–Barré syndrome.

Enterobacteriaceae

Endotoxins: Composed of lipid and polysaccharide, elicit symptoms like fever, chills, and DIC; includes K1 antigen related to neonatal meningitis.
K. pneumoniae Capsule: Inhibits phagocytosis; Vi antigen of Salmonella serotype Typhi impairs intracellular killing.
Laboratory Diagnosis: Eosin methylene blue (EMB) and MacConkey's agar differentiate lactose fermenters; XLD and HE agar are selective for Salmonella and Shigella.
Antimicrobial Susceptibility: E. coli and P. mirabilis are susceptible to ampicillin; various species exhibit resistance to first-generation cephalosporins.

Description

Test your knowledge on Aeromonas, a group of bacteria typically found in aquatic environments. This quiz explores their motility, metabolic processes, and their association with intestinal and extraintestinal diseases. Assess your understanding of how these organisms contribute to diarrheal disease through enterotoxin production.