Final: - Bacillus

Question 1

What is Pseudomonas aeruginosa?

Answer 1

Opportunistic pathogen, particularly in hospital settings. Resistant to soaps, detergents, and disinfectants. Causes infections in burns, wounds, UTIs, pneumonia, and septicemia. Known for producing exotoxins. Requires antibiotic sensitivity testing due to frequent resistance.

Question 2

What is Brucella spp.?

Answer 2

Causes brucellosis (undulant fever), primarily zoonotic from cattle (B. abortus) and pigs (B. suis). Symptoms include fluctuating fever, chills, body aches, and organ involvement. Transmission through raw milk, animal contact, or broken skin. Treated with antibiotics, but no human vaccine.

Question 3

What is Francisella tularensis?

Answer 3

Causative agent of tularemia (rabbit fever), primarily zoonotic from rabbits and rodents. Spread via insect vectors (ticks, deer flies) or direct contact with animal carcasses. Symptoms include fever, ulcers at the entry site, and pneumonia. Treated with antibiotics, and a live attenuated vaccine exists for at-risk individuals.

Question 4

What is Bordetella pertussis?

Answer 4

Causative agent of whooping cough (pertussis). Transmission via droplets from infected individuals. Causes severe coughing fits, often with a characteristic ‘whoop.’ Particularly dangerous for infants. Prevented with DTaP vaccination.

Question 5

What is Legionella pneumophila?

Answer 5

Causative agent of Legionnaires’ disease and Pontiac fever. Spread via inhalation of aerosolized contaminated water (air conditioners, cooling towers). Causes pneumonia with fever, chills, and respiratory distress. Risk groups include the elderly, smokers, and immunocompromised. Treated with erythromycin.

Question 6

What is Yersinia pestis?

Answer 6

Causative agent of plague (bubonic, septicemic, and pneumonic). Spread by flea bites or aerosolized droplets. Causes swollen lymph nodes (buboes), septicemia, and pneumonia. High mortality if untreated. Treatable with antibiotics if caught early. Vaccines available for high-risk individuals.

Question 7

What is Haemophilus influenzae?

Answer 7

Causes acute bacterial meningitis, primarily in young children. Can also cause respiratory tract infections and middle ear infections. Untreated meningitis has a high mortality rate. A vaccine (Hib) is available for prevention.

Question 8

What is Haemophilus aegyptius?

Answer 8

Causes acute conjunctivitis (pinkeye). Characterized by hemorrhaging in the eye, leading to a bright pink sclera.

Question 9

What is Haemophilus ducreyi?

Answer 9

Causative agent of soft chancre (chancroid), a sexually transmitted infection. Causes painful ulcers and swollen lymph nodes in the genital area.

Question 10

What are Haemophilus parainfluenza and Haemophilus aphrophilus?

Answer 10

Part of the normal flora in the mouth and nasopharynx. Can cause endocarditis if introduced into the bloodstream during dental procedures, oral injury, or periodontal disease.

Question 11

What is Escherichia coli (E. coli)?

Answer 11

Several strains are pathogenic. Can cause traveler’s diarrhea, infant diarrhea, and Hemorrhagic colitis (due to strain O157:H7). The latter causes bloody diarrhea and can progress to hemolytic uremic syndrome (HUS), which is especially dangerous for the elderly, young children, and immunocompromised.

Question 12

What is Klebsiella pneumoniae?

Answer 12

Opportunistic pathogen, can cause pneumonia, UTIs, meningitis, wound infections, and septicemia. Particularly dangerous for immunocompromised individuals.

Question 13

What is Enterobacter aerogenes?

Answer 13

Common cause of UTIs and nosocomial infections, including wound infections and bacteremia.

Question 14

What is Serratia marcescens?

Answer 14

Opportunistic pathogen, causes pneumonia, UTIs, wound infections, and septicemia, particularly in hospitalized patients.

Question 15

What is Citrobacter freundii?

Answer 15

Opportunistic pathogen, associated with UTIs, bacteremia, and wound infections, especially in immunocompromised individuals.

Question 16

What is Salmonella typhi?

Answer 16

Causative agent of typhoid fever. Transmission via fecal-oral route, often from contaminated food or water. Symptoms include fever, abdominal pain, and intestinal bleeding. Can cause perforation of the intestine and septicemia. Mortality rate of 10-15% if untreated.

Question 17

What are Other Salmonella species (e.g., S. enteritidis)?

Answer 17

Zoonotic pathogens that contaminate food products, especially poultry and eggs. Can cause gastrointestinal illness, including diarrhea, nausea, vomiting, and abdominal cramps.

Question 18

What are Shigella spp.?

Answer 18

Causes shigellosis (bacillary dysentery), characterized by abdominal cramping, bloody and mucous-filled stool, and fever. Shigella does not invade the bloodstream but produces an exotoxin (shigatoxin) that damages the intestinal lining.

Question 19

What are Proteus spp., Morganella spp., Providencia spp.?

Answer 19

Opportunistic pathogens commonly associated with nosocomial infections, including UTIs, wound infections, and pneumonia. Typically infect immunocompromised individuals.