general characteristics.docx

***Escherichia coli*** - Gram -ve bacilli - Motile; facultative anaerobe Grow in both aerobic and anaerobic - \ this is how they cause diseases. - Non-lactose fermenter. - \- Urease and oxidase negative. - \- H~2~S negative ***Campylobacter spp.*** - Gram -ve - Slend...

***Escherichia coli*** - Gram -ve bacilli - Motile; facultative anaerobe Grow in both aerobic and anaerobic - \ this is how they cause diseases. - Non-lactose fermenter. - \- Urease and oxidase negative. - \- H~2~S negative ***Campylobacter spp.*** - Gram -ve - Slender, curved, Long spiral-shaped rods, maybe coccoid in really old culture (a bit more round) - Motile (single polar unsheathed flagellum at one or both ends) - Non-spore former - Microaerophilic & capnophilic Different to Enterobacteriaceae - Have to grow them at reduced oxygen and increased CO~2~ - Fastidious - Temperature -- grows at 42°C -- adapted to chickens with higher body temp. - Unable to use sugars either oxidatively or fermentatively; derive energy from amino acids; Not grow on MAC or NA; Should grow them on chocolate agar. - Virulence factors - Motility Allow them to burrow(dig) down through the mucus layer - Heat-labile enterotoxin = heat sensitive ***Pseudomonas* General characteristics:** - Gram -ve rods - Motile by 1 or more polar flagella - Non-spore former - Strictly aerobic - Oxidase +ve - Catalase +ve ***Acinetobacter* General characteristics** - Gram-negative - **Short** bacilli in pairs - Non-motile - Capsulated - Strictly aerobic - Oxidase - ve - Catalase + ve ***Chryseobacterium* General Characteristics** Not so common, opportunistic ♣ Gram-negative rods\ ♣ Non-motile\ ♣ Yellow pigment on BA distinctive -- S. aureus can also be yellow on BA\ ♣ Strictly aerobic\ ♣ Oxidase +ve\ ♣ Catalase +ve ***Proteus mirabilis*** **Overview** \- gram-negative bacillus. \- Belongs to the family **Enterobacteriaceae** \- Widely distributed in soil and water and part of the normal human intestinal flora. \- Causes urinary tract infections (UTIs). **Characteristics** \- Non-spore-forming and highly motile. \- Facultative anaerobic (can survive in both aerobic and anaerobic environments). \- Non-lactose fermenter and oxidase - ve. \- Urease + ve (produces urease enzyme). Haemophilus **General characteristics** - Gram-negative - Pleomorphic small bacilli -- sometimes almost coccal in shape, sometimes as short filaments - Non-motile - Non-spore former - Encapsulated or non-encapsulated Only the capsulated forms are called Type B -- super virulent form So have HIB -- H. influenzae Type B vaccine - Aerobic, facultatively anaerobic - Oxidase +ve, Catalase V **Listeria** spp. -- 7 species *L. monocytogenes* **General characteristics** - Gram-positive coccobacilli - motile at room temperature 25 - Non-spore former - Facultatively anaerobic, facultative intracellular organisms can live in both inside or outside the cell - Oxidase - ve , catalase and aesculin + ve - Grow optimally at 35o C to 37o C, but growth also occurs at 4oC fridge - Usually β-haemolytic Unwashed lettuce, deli meats, pregnant--vulnerable **Clostridium** **General Characteristics** - Gram-positive may appear Gram-negative in older cultures - Straight or curved rods may appear singly, in pairs, or in chains - Spore former -- Endospores so it looks like a gram -ve rod with gram +ve cocci in it - Motile -- peritrichous flagella; except *C. ramosum, C. innocuum* - Non-encapsulated -- except *C. perfringens* - Obligate anaerobes strict anaerobes Some *Clostridium* like *C. difficile* will die, or sporulate and the spores will survive. Some are oxygen tolerant, like C. perfringens -- won't die but not going to grow. - Catalase -- ve - Saccharolytic can break down sugars and eat sugars - Proteolytic break down proteins