Microorganisms that cause Gastroenteritis Respiratory infection Cheng Ling How,Tai Lily,Peach Subannaphong, Priyanka Hingorani Stella Muloongo
Cheng Ling How, Tai Lily, Peach Subannaphong, Priyanka Hingorani & Stella Muloongo
Contents Bacteria that cause: Gastroenteritis and Respiratory Infection e Viruses that cause Gastroenteritis and Respiratory Infection Fungi that cause: Respiratory Infection
Contents — — — Bacteria that cause: Gastroenteritis and Respiratory Infection Viruses that cause: Gastroenteritis and Respiratory Infection Fungi that cause: Respiratory Infection
Bacteria That Cause Gastroenteritis Signs symptoms Pathogenesis Clinical Features Staphylococcus aureus Nausea and Enterotoxin acts Very common, abrupt onset, intense vomiting on receptors for up to 24 hours, regular recovery in 24-48 in the gut that hours. Occurs in persons eating the same food transmit impulse No treatment usually necessary except to to medullary restore fluids and electrolytes ters that control Bacillus cereus Vomiting or Enterotoxin formed in Witn incubation period of 2-8 hours, mainly diarrhea food or in gut from vomiting With incubation period of 8-16 growth of B cereus. hours, mainly diarrhea Clostridium perfringens Watery Enterotoxin produced Abrupt onset of profuse diarrhea: vomiting during sporulation occasionally Recovery usual without treatment in gut, causes in 1-4 days. Many clostridia in cultures of faod d feces of patients Clostridium botulinum Paralysis Toxin absorbed Diplopia, dysphagia, dysphonia, difficulty from gut blocks eathing Treatment requires ventilatory acetylcholine at support and antitoxin Diagnosis confirmed by neuromuscular finding toxin in blood or stool Junction DIAGNOSTICS 1)Staphylococcus aureus Gram stain-(+), in clusters; Culture- beta-hemolytic, golden yellow pigment 2)Bacillus cereus Culture specimen from suspected food source 3)Clostridium perfringens: Culture( anaerobic ) Gram stain-(+) 4)Clostridium botulinum Culture(anaerobic ) Gram stain -(+)
Bacteria That Cause Gastroenteritis DIAGNOSTICS : Staphylococcus aureus : Bacillus cereus : Clostridium perfringens : Clostridium botulinum : 1) Gram stain – (+), in clusters ; Culture- beta-hemolytic, golden yellow pigment 2) Culture specimen from suspected food source 3) Culture ( anaerobic ) , Gram stain – (+) 4) Culture (anaerobic ) , Gram stain – (+)
Organism Symptoms Pathogenesis Clinical Features Escherichia coli Watery ETEC in the gut Usually abrupt onset of diarrhea; vomiting rare enterotoxigenic; diarrhea produces heat-labile Serious infections in newborns. In adults ETEC (HL)or heat-stable usually self-limiting in 1-3 days (HSJenterotoxins Toxins cause hypersecretion in small intestine Escherichia coli Dysentery Inflammatory invasion Acute bloody diarrhea with malaise, headache, enteroinvasive of the colonic high fever, and abdominal pain. Severe disease ElEC) mucosa: similar to in poorly nourished children. WBC presentin o shigellosis. EIEC is stool ely related to Shi Escherichia coli Watery, STEC produces shi Causes bloody diarrhea, hemorrhagic colitis, and (Shiga-toxin like toxins. Ofte the majority of causes of hemolytic-uremic produ cing: STEC) diatrhea serotype 0157: H7 yndrome Culture stool for sorbitol-negative E coli and serotype isolates with antisera for 0157: 1-17. Other serotypes may be detected by toxin production using enzyme mmunoassays that contain antibodies to the Shiga-like toxins
Clinical Features Organism Symptoms Pathogenesis Escherichia coli Watery EPEC attaches to mucosal Insidious onset over 3-6 days with listlessness, (enteropathogenic; diarrhea thelial cells and poor feeding, and diarrhea. Usually lasts 5-15 EPEC) roduces cytoskeletal days. Dehydration, electrolytic imbalance changes; may invade and other complications may cause death cells Different from Antimicrobial therapy is important other Ecoli that are enteroadherent o enteroaggregative and cause diarrhea VIbrio parahaemolyticus Watery Toxin causes Abrupt onset of diarrhea in groups consuming hypersecretion; vibrios same food, especially crabs and other seafood. Recovery is usually complete in tools may be days. Food and stool cultures are positive Diagnostics: D)E coli: Gram stain-(); Pink colonies on MacConkey agar; Dark purple to black on EMB agar 2)Vibrio parahaemolyticus: Blue colonies on TCBS agar(non- sucrose fermenting)
Diagnostics : 1) E. coli 2) Vibrio parahaemolyticus : Gram stain- (-) ; Pink colonies on MacConkey agar ; Dark purple to black on EMB agar. : Blue colonies on TCBS agar. ( nonsucrose fermenting )