Question

Write three to five sentences about Pseudomonas aeruginosa bacteria. Such as the shape of the bacteria, gram stain, diseases that can be caused by this bacteria, and etc.

Answer 1

Ans.

• Pseudomonas aeruginosa is a monoflagellated, gram-negative bacterium of rod shaped with unique versatility in nutrition.
• It was first described by Pasteur in the late 19th century as an opportunistic infectious agent.
• It is rod shaped with a length of 1-5 micrometer and width of 0.5-1.0 micrometer.
• It is an obligate respirator i.e. uses aerobic respiration for it's optimal metabolism but in certain situations can also utilize anaerobic respiration.
• It is a very ubiquitous microbe because of it's wide catabolizing capacity and is found in most of the places in environment like soil, water, air, plants and animals.
• P. aeruginosa is the predominant inhabitant in all oligotropic aquatic ecosystems.
• It is called as an opportunistic pathogen because of it's property of infecting only immunocompromised patients for eg. cancer or AIDS patients.

Cell structure and metabolism;

• It's outer membrane contains Protein F (OprF), which functions as a porin and regulates movement of molecules or ions across the cell.
• This protein also plays some structural role and helps maintain shape of bacterial cell.
• F protein also reduces permiability of outer membrane of bacteria, preventing intake of harmful molecules into the cell and providing high resistance to the bacteria against antibiotics.
• Movement in P. aeruginosa is done with the help of flagellum and pilli.
• It prefer aerobic respiration for the metabolism and gains energy by the transfer electrons from glucose to oxygen (ultimate electron acceptor).
• It synthesizes pyochelin and pyoverdin, two siderophores, in order to overcome it's iron deficiency while infecting a host.

Genome ;

• It's genome size is of about 5.2 to 7 million base pairs (Mbp) and most of the content (~65%) is made up of guanine and cystine.
• It posses a single and supercoiled circular chromosome located in cytoplasm.

Clinical infections;

• Infections caused by P. aeruginosa can be divided into 2 categories : those occuring in the patients and those occuring in healthy individuals.
• A number of infections can be caused by this bacterium such as;

1. Urinary Tract Infections (UTI)
2. Community acquired pneumonia (CAP)
3. Ventilator associated pneumonia (VAP)
4. Endocarditis
5. Meningitis
6. Ocular, skin and ear infections

Treatments;

• Following drugs are the treatment of choice for this infection ;

1. Aminoglycosides
2. Carbapenems
3. Third generation cephalosporins
4. Fourth generation cephalosporins
5. Fluoroquinolones
6. Extended spectrum penicillins