1. Batterjee Medical College

2. Dr. Manal El Said Head of Medical Microbiology Department Brucella Species (B. abortus, B. suis, B. melitensis)

3. Batterjee Medical College Brucella Species (B. abortus, B. suis, B. melitensis) Diseases Brucellosis (undulant fever). Incubation period of 1 to 3 weeks & onset acute or gradual Nonspecific symptoms: fever, chills, fatigue, malaise, anorexia, & weight loss occur. Undulating (rising-and-falling) fever pattern. Enlarged lymph nodes, liver & spleen are frequently found. Pancytopenia occurs. B. melitensis infections more severe & prolonged whereas B. abortus are more self-limited. Osteomyelitis is the most frequent complication. Secondary spread from person to person is rare.

4. Batterjee Medical College Brucella Species (B. abortus, B. suis, B. melitensis)

5. Batterjee Medical College Characteristics Small gram-negative rods. Habitat and Transmission Reservoir is domestic livestock. Transmission is via: - Unpasteurized milk & cheese - Direct contact with infected animal. Brucella Species (B. abortus, B. suis, B. melitensis)

6. Batterjee Medical College Brucella Species (B. abortus, B. suis, B. melitensis)

7. Batterjee Medical College Brucella Species (B. abortus, B. suis, B. melitensis)

8. Batterjee Medical College Organisms localize in reticuloendothelial cells, especially liver & spleen. Able to survive and replicate intracellularly. Predisposing factors include consuming unpasteurized dairy products & working in abattoir. Pathogenesis Brucella Species (B. abortus, B. suis, B. melitensis)

9. Batterjee Medical College Brucella Species (B. abortus, B. suis, B. melitensis)

10. Batterjee Medical College Brucella Species (B. abortus, B. suis, B. melitensis)

11. Batterjee Medical College Laboratory Diagnosis Gram-stained smear plus culture on blood agar plate. Identified by biochemical reactions & by agglutination with known antiserum. Serologically by detecting antibodies in patient's serum. Brucella Species (B. abortus, B. suis, B. melitensis)

12. Batterjee Medical College Treatment Tetracycline plus rifampin. Pasteurize milk; vaccinate cattle. No human vaccine is available Prevention Brucella Species (B. abortus, B. suis, B. melitensis)

13. Batterjee Medical College Dr. Manal El Said Head of Medical Microbiology Department Francisella tularensis

14. Batterjee Medical College Francisella tularensis Diseases Tularemia. Presentation can vary from sudden onset of influenzalike syndrome to prolonged onset of low-grade fever & adenopathy. Approximately 75% of cases are "ulceroglandular" type, in which site of entry ulcerates & regional lymph nodes are swollen & painful. Less frequent forms of tularemia include glandular, oculoglandular, typhoidal, gastrointestinal, & pulmonary. Disease usually confers lifelong immunity.

15. Batterjee Medical College Francisella tularensis Characteristics Small gram-negative rods. Reservoir is many species of wild animals, especially rabbits, deer & rodents. Transmission is by ticks, aerosols, contact & ingestion. Habitat and Transmission

16. Batterjee Medical College Pathogenesis Francisella tularensis Organisms localize in reticuloendothelial cells. Francisella tularensis enters respiratory tract & (2) lamina propria of respiratory bronchioles via M cells; (3) Digested antigen is taken up by dendritic cells; dendritic cells travel to regional lymph nodes &present F. tularensis antigens to T-helper 1 cells; (4) T- helper 1 cells proliferate; they may return to site of initial infection; (5) restimulation by local antigen presenting cells results in interferon-γ production & macrophage activation; (6) Failure to clear F. tularensis results in granuloma formation.

17. Batterjee Medical College Laboratory Diagnosis Culture is rarely done because special media are required & there is high risk of infection of laboratory personnel. Serologic tests detect antibodies in patient's serum. Francisella tularensis Francisella tularensis in a liver cell.

18. Batterjee Medical College Francisella tularensis

19. Batterjee Medical College Francisella tularensis Colonization of Francisella tularensis on various media, namely: (A) buffered charcoal yeast extract; (B) chocolate agar medium; (C) sheep’s blood agar; (D) cysteine heart agar.

20. Batterjee Medical College Treatment Francisella tularensis Streptomycin. Live, attenuated vaccine for persons in high-risk occupations. Protect against tick bites. Prevention

21. Batterjee Medical College Dr. Manal El Said Head of Microbiology Department Pasteurella multocida

22. Batterjee Medical College Pasteurella multocida Diseases Rapidly spreading cellulitis at site of animal bite is indicative of P. multocida infection. Incubation period is brief, less than 24 hours. Osteomyelitis can complicate cat bites, because cats' sharp, pointed teeth can implant organism under periosteum. Wound infection, e.g., cellulitis

23. Batterjee Medical College Pasteurella multocida Characteristics Small gram-negative rods. Habitat and Transmission Reservoir is mouth of many animals, especially cats & dogs. Transmission is by animal bites.

24. Batterjee Medical College Pathogenesis Pasteurella multocida Spreads rapidly in skin & subcutaneous tissue.

25. Batterjee Medical College Pasteurella multocida Laboratory Diagnosis Gram-stained smear and culture.

26. Batterjee Medical College Treatment Pasteurella multocida Penicillin G.. Prevention Ampicillin should be given to individuals with cat bites. There is no vaccine.

27. Batterjee Medical College Capnocytophaga gingivalis It is gram-negative fusiform rod that is associated with periodontal disease It can be opportunistic pathogen, causing sepsis in immunocompromised patients. Capnocytophaga

28. Batterjee Medical College Capnocytophaga canimorsus It is a member of the oral flora of dogs and causes infections following dog bites. It cause sepsis in immunocompromised patients, especially those without spleen. Capnocytophaga

29. Batterjee Medical College This is group of small gram-negative rods that have in common the following: Slow growth in culture, Requirement for high CO 2 levels to grow in culture Ability to cause endocarditis. -They are members of the human oropharyngeal flora and can enter the bloodstream from that site. -The name "HACEK" is an acronym of the first letters of the genera of the following bacteria: Haemophilus aphrophilus and Haemophilus paraphrophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae. HACEK Group

30. Batterjee Medical College Vibrio cholerae Diseases Cholera. Watery diarrhea (Rice-water stool) in large volumes. There are no red blood cells or white blood cells in stool. There is no abdominal pain & subsequent symptoms are referable to marked dehydration. Loss of fluid & electrolytes leads to cardiac & renal failure. Acidosis & hypokalemia occur as result of loss of bicarbonate & potassium in stool.

31. Batterjee Medical College Vibrio cholerae Diseases

32. Batterjee Medical College Vibrio cholerae Comma-shaped gram-negative rods. Oxidase-positive Characteristics Habitat and Transmission Habitat is human colon. Transmission is by fecal–oral route.

33. Batterjee Medical College Vibrio cholerae Pathogenesis Massive, watery diarrhea caused by enterotoxin that activates adenylate cyclase by adding ADP-ribose to stimulatory G protein. Increase in cyclic AMP causes outflow of chloride ions & water. Toxin has two components: - Subunit A: ADP-ribosylating activity - Subunit B: binds toxin to cell surface receptors.

34. Batterjee Medical College Vibrio cholerae Pathogenesis Organism produces mucinase, which enhances attachment to intestinal mucosa. Infectious dose is high (>10 7 organisms). Carrier state rare string test

35. Batterjee Medical College Vibrio cholerae Gram-stained smear and culture. (During epidemics, cultures not necessary.) Agglutination of the isolate with known antisera confirms the identification. Laboratory Diagnosis Vibrio cholerae on TCBS agar string test

36. Batterjee Medical College Treatment Vibrio cholerae Treatment of choice is fluid and electrolyte replacement. Tetracycline is not necessary but shortens duration and reduces carriage. Public health measures, e.g., sewage disposal, chlorination of the water supply, stool cultures for food handlers, and handwashing prior to food handling. Vaccine containing killed cells has limited effectiveness. Tetracycline used for close contacts. Prevention

37. Batterjee Medical College Comma-shaped gram-negative rod found in warm sea water. Causes watery diarrhea Acquired by eating contaminated raw seafood. Outbreaks have occurred on cruise ships in Caribbean. Diarrhea is mediated by enterotoxin similar to cholera toxin.. Vibrio parahaemolyticus Forms GREEN non-sucrose fermenting agars

38. Batterjee Medical College Comma-shaped gram-negative rod found in warm sea water. Causes cellulitis & life-threatening sepsis with hemorrhagic bullae. Acquired either by trauma to skin, especially in shellfish handlers, or by ingestion of raw shellfish, especially in patients who are immunocompromised or have liver damage. Vibrio vulnificus

39. Batterjee Medical College Dr. Manal El Said Campylobacter jejuni Head of Medical Microbiology Department

40. Batterjee Medical College Habitat is human & animal feces. Transmission is by fecal–oral route. Campylobacter jejuni Diseases Enterocolitis. Characteristics Comma-shaped gram-negative rods. Microaerophilic. Grows well at 42°C Habitat and Transmission

41. Batterjee Medical College Campylobacter jejuni Invades mucosa of colon but does not penetrate Sepsis rarely occurs. Pathogenesis Laboratory Diagnosis Gram-stained smear plus culture on special agar, e.g., Skirrow's agar, at 42°C in high-CO 2, low-O 2 atmosphere.

42. Batterjee Medical College Public health measures, e.g., sewage disposal, chlorination of the water supply, stool cultures for food handlers, and handwashing prior to food handling. No preventive vaccine or drug is available. Usually symptomatic treatment only; erythromycin for severe disease. Campylobacter jejuni Treatment Prevention

43. Batterjee Medical College Dr. Manal El Said Helicobacter pylori Head of Medical Microbiology Department

44. Batterjee Medical College Helicobacter pylori Diseases Characteristics Gastritis & peptic ulcer. Risk factor for gastric carcinoma. Curved gram-negative rod. Habitat is the human stomach. Transmission is by ingestion. Habitat and Transmission

45. Batterjee Medical College Organisms synthesize urease, which produces ammonia damages gastric mucosa. Ammonia neutralizes acid pH in stomach, which allows the organism to live in gastric mucosa. Helicobacter pylori Pathogenesis

46. Batterjee Medical College Laboratory Diagnosis Gram stain and culture. Urease-positive. Serologic tests for antibody "urea breath" test are useful. Helicobacter pylori

47. Batterjee Medical College Treatment Amoxicillin, metronidazole & bismuth (Pepto- Bismol). Prevention No vaccine or drug is available. Helicobacter pylori

48. Batterjee Medical College Dr. Manal El Said Head of Medical Microbiology Department Bacteroides fragilis

49. Batterjee Medical College Bacteroides fragilis Diseases Characteristics Habitat and Transmission Sepsis, peritonitis, and abdominal abscess. Anaerobic, gram-negative rods Habitat is the human colon, where it is the predominant anaerobe. Transmission occurs by spread from the colon to the blood or peritoneum.

50. Batterjee Medical College Pathogenesis Lipopolysaccharide in cell wall is chemically different from & less potent than typical endotoxin. No exotoxins known. Capsule is antiphagocytic. Predisposing factors to infection include bowel surgery and penetrating abdominal wounds. Bacteroides fragilis

51. Batterjee Medical College Laboratory Diagnosis Gram-stained smear plus anaerobic culture Identification based on biochemical reactions and gas chromatography. Serologic tests not useful. Bacteroides fragilis

52. Batterjee Medical College Treatment Prevention Bacteroides fragilis Metronidazole, clindamycin & cefoxitin are effective Abscesses should be surgically drained. Resistance to penicillin G, some cephalosporins, and aminoglycosides is common. Plasmid-encoded β -lactamase mediates resistance to penicillin. In bowel surgery, perioperative cefoxitin can reduce the frequency of postoperative infections. No vaccine is available.