13. Scarlet Fever Rash caused by
Streptococcus pyogenes
Streptococcus epidemitis: normal flora (non pathogenic) on the
body that is opportunistic, can cause UTI’s.
14. Necrotizing Fasciitis due to
Streptococcus pyogenes
http://emedical-help.com/necrotizing-fasciitis-flesh-eating-disease/
Puerperal Sepsis: “Child Fever”
15. Diagnosis, Prevention, Treatment
Culture swabs from lesions
Beta-hemolytic on Blood Agar plates
Antibody titer
Proper hygiene during wound care
Prolonged treatment with penicillin (Rheumatic
fever patients)
Penicillin
Debridement of infected tissues
17. Streptococcus agalactiae/dysgalactiae (Group B)
Neonatal meningitis and sepsis
MOT and Pathology
Normal vaginal flora: Can colonize genital tract and cause
neonatal meningitis and sepsis
Prevention
Prophylactic Ampicillin (mother)
And Treatment
Penicillin (newborn)
18. Streptococcus mutans = facultative anaerobe
Dental caries (cavities)
• Metabolizes sugars to lactic acid decays enamel
• Excretes a sticky polysaccharide for adhesion to
surfaces and each other plaque
• Biofilm protects from extreme and changing
environment of the mouth
• Biofilm plaque best removed mechanically (floss)
• Oral Hygiene is important
• Treatment: Fill cavities
38. Enterobacteriaceae
• Large family of gram-negative rods
• Found primarily in colon
• Common features
• Facultative anaerobe, non-spore forming
39. Escherichia coli
• MOT & Pathology
• Normal Flora of human colon
• UTI (most common cause)
• Fecal-oral
• O157:H7 toxin: hemolytic-uremic syndrome
• Treatment
• Quinolones
• Self limiting
• Prevention
• Remove urinary catheters, ♀ wipe front to back,
water and food handling, handwashing
40. Salmonella enteritidis
• MOT & Pathology
• Fecal-oral (human and animal)
• Eggs and poultry
• Reptiles
• Treatment
• Self-limiting
• Rehydration therapy
• Prevention
• Public health
• Personal hygiene
41. Salmonella typhi
• MOT & Pathology
• Fecal-oral (human only)
• Typhoid fever
• Treatment
• Ciprofloxacin
• Prevention
• Personal hygiene
• Vaccine available (for travelers only)
42. Shigella dysenteriae
• MOT & Pathology
• Fecal-oral (human only)
• ID50 =10
• The four Fs: fingers, flies, food, and feces
• Treatment
• Rehydration/Ciprofloxacin
• Prevention
• Public health
• Personal hygiene
43. Campylobacter jejuni
• MOT & Pathology
• Fecal-oral (human and animal)
• Food or water contamination
• Treatment
• Ciprofloxacin
• Prevention
• Public health
• Personal hygiene
44. pH – Neutrophiles
& Acidophiles
As with temperature, bacteria have minimum, optimum and
maximum pH ranges.
Neutrophiles
• Protozoans and most bacteria have an optimum pH range of
6.5 to 7.5.
• pH range of human organs and tissues.
Acidophiles
• Most fungi & some bacteria grow best in acid niches.
• Example: Chemoautotrophic bacteria that live in mines and
in water that runs off from waste rock around mines.
• Obligate acidophiles have to live in an acidic environment.
• Acid-tolerant Microbes will survive in an acid environment, but
do not prefer that.
Images: HelicobacterPylori : Electron micrograph of H. pylori possessing multiple flagella.
Yutaka Tsutsumi, M.D. Professor Department of Pathology Fujita Health University School of
Medicine
Helicobacter
pylori
• Gram-negative, microaerophilic, and
acidophilic bacterium.
• Infects various areas of the stomach and
duodenum.
• Many cases of peptic ulcers, gastritis,
duodenitis, and perhaps some cancers are
caused by H. pylori infections.
• However, many who are infected do not
show any symptoms.
• Helicobacter spp. only known
microorganisms to thrive in highly acidic
environment of stomach.
45. Helicobacter pylori
• MOT and Pathology
– Ingestion, produce
ammonia
– Gastric ulcer
– Carcinoma
• Treatment
– Antibiotics
• Prevention
– None
46. pH : Cholera (Alkalinophiles)
Alkilinophiles
• Can live in water as well as soil with pH’s around
11.5 (14 is max alkilinity)!
• Example: Vibrio cholera (Cholera) will grow
outside the body at a pH of 9.0.
• Infectious gastroenteritis caused by the bacterium
Vibrio cholerae.
• Transmission occurs through ingesting contaminated
water or food.
• Major reservoir for cholera long assumed to be
humans, but considerable evidence exists that aquatic
environments can serve as reservoirs of the bacteria.
• Gram-negative bacterium that produces cholera
Alkilinophiles
• Action on mucosal epithelium lining of the small
intestine responsible for the characteristic massive
diarrhea.
• One of the most rapidly fatal illnesses known.
Progresses from first liquid stool to shock in 4 to 12
hours, with death quickly following without rehydration
treatment.
47. Vibrio cholerae
• MOT and Pathology
– Fecal-oral
– Contaminated H2O
– Enterotoxin
– Watery stools
• Treatment
– Rehydration therapy
• Prevention
– Public health
– Personal hygiene
48. Vibrio parahemolyticus
• MOT and Pathology
– Lives in warm seawater
– Ingestion of raw/undercooked seafood
• Treatment
– Self limiting (three days)
• Prevention
– Proper refrigeration and cooking of seafood
49. Nosocomial Gram-negative Bacilli
Klebsiella pneumoniae: Pneumonia and UTI
Proteus vulgaris: UTI especially hospital acquired
Pseudomonas aeruginosa: Burn sepsis and UTI and
more
Serratia marcescens: Burn sepsis
50. Klebsiella pneumoniae
• MOT & Pathology
– Respiratory tract and intestinal tract
– Droplet
– Catheter
• Treatment
– Antibiotics
• Prevention
– Prompt removal of urinary catheter
51. Proteus vulgaris
• MOT & Pathology
– Human colon
– Soil and H2O
– Highly motile, colonizes urethra, leads to
ascending infection
• Treatment/Prevention
– Antibiotics
– Prompt removal of catheters
60. Yersinia pestis
• Plague (black death)
• Killed one quarter of the population of Europe
in the middle ages
• Fleas transmit
• Bubos: inflammed
lymphnodes
• Droplet = pneumonic plague
61. Lyme disease
Causative agent:
Borrelia burgdorferi
• Reservoir: Deer
• Vector: Ticks
• First symptom:
Bull's-eye rash
• Second phase:
Irregular heartbeat,
encephalitis
• Third phase: Arthritis
62.
63. Obligate Intracellular Parasites
• Chlamydia trachomatis: NGU, pelvic
inflammatory disease (PID), eye infection
• Rickettsia rickettsii: Rocky mountain spotted
fever (RMSF)
• Rickettsia prowazeki: Typhus
• Lack ability to produce enough ATP to grow
independently
64. Chlamydia trachomatis
• Most common bacterial STI in USA
• Eye infection, fomites, birth canal
• PID
• Infertility
• Erythromycin
71. Mycobacterium leprae
• Leprosy
• Direct contact
• Nasal or skin secretions
• Replicates in skin
• Anesthesia, bone re-absorption
• Loss of digits or tip of nose
• Antibiotics
• Isolation of patients
72. Mycoplasma
• Smallest bacteria
• Lack cell wall
• Fluorescent stains to visualize
• Mycoplasma pneumoniae: walking pneumonia
– Droplet infection
– Common on campuses
– May be self-limiting or require antibiotics
73. Question
Staphylococcus and Streptococcus can be easily
differentiated in a lab by which of the following?
a) Cell shape
b) Gram stain reaction
c) Growth in high salt concentration
d) Ability to cause disease
e) Glucose fermentation