🦠 bacteria

Staphylococcus aureus

Staphylococcus aureus

Gram positive cocci in clusters facultatively anaerobic catalase positive coagulase positive golden-yellow colonies (staphyloxanthin)

Staphylococcus epidermidis

Gram positive cocci in clusters catalase positive coagulase negative resident skin flora causes prosthesis-associated infections

Staphylococcus saprophyticus

Gram positive cocci in clusters catalase positive coagulase negative cause acute cystitis in young women

Streptococcus Enterococcus

Gram positive cocci in chains aerobic, facultatively anaerobic

Peptostreptococcus Peptococcus

Gram positive cocci in chains anaerobic

Listeria monocytogenes

Gram positive bacilli non-spore-forming aerobic foodborne, mother-to-baby transmission

Corynebacterium diphtheriae

Gram positive pleomorphic bacilli non-spore-forming aerobic coryneform (characteristic swelling at end) cause diphtheria

Corynebacterium striatum

Gram positive pleomorphic bacilli commensal of skin & mucous membrane opportunisitic pathogen

Bacillus anthracis

Gram positive bacilli boxcar shaped aerobic single endospore cause anthrax

Bacillus cereus

Gram positive bacilli boxcar shaped aerobic single endospore cause food poisoning, associated with indwelling catheters

Nocardia

Gram positive bacilli beaded/branching appearance partially acid-fast (mycolic acid) causes suppurative granulomatous inflammation

Mycobacterium tuberculosis

Gram positive bacilli aerobic

Clostridium tetani Clostridium perfringens Clostridium botulinum Clostridium difficile

Gram positive bacilli anaerobic spore-forming

Neisseria gonorrhoeae

Gram negative diplococci strictly aerobic oxidase positive Thayer-Martin agar sexual transmission

Neisseria meningitidis

Gram negative diplococci strictly aerobic oxidase positive capsule transmission by droplet/mucosal contact serogroups: A,B,C,X,Y,W-135

Enterobacteriaceae

Gram negative bacilli facultatively anaerobic glucose fermenter oxidase negative commensals in large bowel

Escherichia coli

[Enterobacteriaceae]

• diarrhoeal disease

• urinary tract infection, bacteriaemia, meningitis in neonates, peritonitis

Klebsiella pneumoniae

[Enterobacteriaceae]

• community-acquired pneumonia

• abscess formation

• intra-abdominal infections

• nosocomial infections

Salmonella enterica

[Enterobacteriaceae]

• gastroenteritis

• typhoidal slamonellae: Slamonella Typhi, Paratyphi A,B,C → systemic infection

• non-typhoidal salmonellae → disseminated/focal infections

Shigella dysenteriae Shigella flexneri Shigella boydii Shigella sonnei

[Enterobacteriaceae]

• bacillary dysentery

• large intestinal inflammation

• Shiga toxin

Vibrio cholerae

curved Gram negative bacilli oxidase positive glucose fermenter actively motile cholera toxin → rice water stools

Pseudomonas aeruginosa

Gram negative bacilli strictly aerobic non-fermenter oxidase positive green pigment, fruity smell hospital-acquired infections

Acinetobacter baumannii

Gram negative coccobacilli strictly aerobic non-fermenter hospital infections, nosocomial infections

Haemophilus influenzae

Gram negative coccobacilli strictly aerobic non-fermenter X factor: haemin; V factor: NAD, NADP chocolate agar polysaccharide capsule (type b children & infants)

Brucella melitensis Brucella abortus Brucella suis

Gram negative coccobacilli zoonosis acute & chronic infection

Bacteroides Fusobacterium Porphyromonas Veillonella

Gram negative strictly anaerobic mixed infections, abscess formation intra-abdominal, genital tract, head & neck infections

Mycoplasma Ureaplasma

cell wall-deficient

Borrelia recurrentis

[Spirochete] microaerophilic relapsing fever

Borrelia burgdorferi

[Spirochete] microaerophilic Lyme disease

Leptospira interrogans

[Spirochete] aerobic zoonosis Leptospirosis infection through broken skin, mucous membranes, droplets, contact with animal

Treponema pallidum

[Spirochete] non cultivable syphilis (sexual transmission) chronic infection congenital infection

Rickettsia Orientia Coxiella Chlamydia

obligate intracellular

Nutrient agar

supportive media

Blood agar

enrichment media detects haemolysis Streptococcus pneumoniae: alpha haemolysis

Chocolate agar

enrichment media heating releases nutrients in blood → Haemophilus influenzae Streptococcus pneumoniae: greenish discoloration

MacConkey agar

selective media, differential media various enteric Gram negative bacilli differentiates lactose fermenters & non-fermenters

Mannitol salt agar

selective media Staphylococcus

Xylose-lysine deoxycholate (XDL) agar

selective media, differential media Salmonella, Shigella

Thiosulphate citrate bile salts (TCBS) agar

selective media, differential media Vibrio

Lowenstein-Jensen agar

selective media, egg-based media Mycobacteria malachite green to inhibit growth of other bacteria

Selenite-F broth

selective media enrichment & selective for Salmonella

Thayer-Martin agar

selective media, enrichment media Neisseria gonorrhoeae additional nutrients to support growth, antimicrobials to suppress growth of normal flora

chromogenic media

distinguish different organisms by displaying color change urine culture