Legionella n mycoplasma

• What type of bacteria is Legionella?

  Aerobic, weakly staining gram-negative pleomorphic bacilli
• How many species of Legionella are known to cause disease in humans?

  Nineteen species
• Which species of Legionella is most commonly associated with human infections?

  Legionella pneumophila
• Where can Legionella bacteria be found in the environment?

  In lakes, rivers, hot springs, and cooling towers
• What is the disease caused by L. pneumophila called?

  Legionnaires' disease or legionellosis
• What are the main symptoms of Legionnaires' disease?

  Fever, chills, dry non-productive cough, headache, and pneumonia
• What is Pontiac fever and how does it differ from Legionnaires' disease?

  Pontiac fever is a flulike illness without pneumonia and is not fatal
• What types of specimens are used for diagnosing Legionella infections?

  Cerebrospinal fluid, blood, vomit, stool, or urine samples
• What methods are used to diagnose Legionella infections?

  Fluorescent antibody staining, serological tests, and molecular methods like PCR
• What is the appearance of colonies of Legionella on BCYE agar?

  Greyish white or blue-green with a ground glass appearance
• What is a key characteristic of Legionella in terms of growth on sheep blood agar?

  There is no growth on supplemented sheep blood agar
• What is the significance of L-cystein for Legionella isolation?


  It is required for primary isolation of Legionella
• How do Mycoplasmas differ from other bacteria in terms of cell structure?

  Mycoplasmas lack cell walls
• What is the size comparison of Mycoplasmas to other bacteria?

  Mycoplasmas are the smallest free-living bacteria
• Why do Mycoplasmas appear pink when stained with Gram stain?

  Because they lack cell walls
• What is the oxygen requirement for Mycoplasmas?

  They are facultatively anaerobic, except for M. pneumoniae, which is a strict aerobe
• What is the family and genus of Mycoplasmas?

  Family: Mycoplasmataceae; Genus: Mycoplasma
• What are some species of Mycoplasma?

  Mycoplasma pneumoniae, Mycoplasma hominis, Mycoplasma genitalium
• How is M. pneumoniae transmitted?

  By infected respiratory secretions
• What is atypical pneumonia and how is it related to M. pneumoniae?

  Atypical pneumonia is characterized by early symptoms like fever, malaise, headache, and sore throat, which are not typical of other types of pneumonia
• What is the common name for M. pneumoniae infections due to mild symptoms?

  Walking pneumonia
• How do M. genitalium and M. hominis infections differ?

  1. genitalium causes nongonococcal urethritis, while M. hominis can cause pyelonephritis and pelvic inflammatory disease
• What types of cancer are associated with Mycoplasma infections?

  Colon, lung, gastric, prostate, and renal cancer
• What is Ureaplasma urealyticum's role in the human body?

  It is part of the normal flora of healthy sexually active men and women
• What infections can Ureaplasma urealyticum cause?

  Nongonococcal urethritis, pyelonephritis, and spontaneous abortion
• What are the laboratory diagnosis specimens for Mycoplasma infections?

  Throat swab, sputum, urethral or genital secretions
• What are the culture and incubation conditions for Mycoplasma?


  Cultured on blood agar or chocolate agar, incubated at 37°C in a microaerophilic environment with 5% CO2 for 48–96 hours
• What are the growth requirements for different Mycoplasma species?

  1. pneumoniae requires glucose, M. hominis requires arginine, U. urealyticum requires urea, and M. genitalium is difficult to culture
• What is the appearance of Mycoplasma colonies on agar?

  They often produce colonies with a 'fried egg' appearance
• How do Ureaplasma differ from Mycoplasma in terms of fermentation?

  Ureaplasma do not ferment carbohydrates and amino acids
• What is the urease test result for Ureaplasma?

  The urease test is positive
• What is the cold agglutination test used for in laboratory diagnosis?

  It detects macroglobulin antibodies that agglutinate human group O cells at low temperature
• Why is the cold agglutination test considered insensitive and nonspecific?

  Because it can produce false positives and does not specifically identify Mycoplasma infections
• What molecular diagnosis method is used for Mycoplasma detection?

  PCR (polymerase chain reaction)