Medically important Bacteria with their Gram staining Reactions
S/No
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
Name of Bacteria
Staphylococcus aureus
Morphology
Clusters/tetrads
Gram Reaction
Gram-positive cocci
Staph epidermidis
Staph saprophyticus
Staph haemolyticus
Staph hominis
Streptococcus pyogenes
Streptococcus agalactiae
Enterococci faecalis
Enterococci faecium
Enterococci (others)
Streptococci pneumoniae
Streptococcus mutans
Neisseria gonorrhoeae
Neisseria meningitidis
Moraxella catarrhalis
Corynebacterium diptheriae
Listeria monocytogenes
Bacillus anthracis
Bacillus cereus
Clostridium tetani
Clostridium botulinum
Clostridium perfringens
Clostridium difficile
Lactobacillus acidophilus
Clusters
Clusters
Clusters
Tetrads and clusters
Chains
Chains
Clusters
Clusters
Chains
Lancet shaped diplococci
Chains or shot rods
Diplococcus,
Diplococcus
Diplococcus
Club-shaped, non-spore
Motile, non-spore former
Long with endospores
Large endospore former
Spore forming
Spore forming
Short, wide spore former
Spore former
Microaerophilic rod
Gram-positive cocci
Gram-positive cocci
Gram-positive cocci
Gram-positive cocci
Gram-positive cocci
Gram-positive cocci
Gram-positive cocci
Gram-positive cocci
Gram-positive cocci
Gram-positive cocci
Gram-positive cocci
Gram-negative cocci
Gram-negative cocci
Gram-negative cocci
Gram-positive Bacilli
Gram-positive Bacilli
Gram-positive Bacilli
Gram-positive Bacilli
Gram-positive Bacilli
Gram-positive Bacilli
Gram-positive Bacilli
Gram-positive Bacilli
Gram-positive Bacilli
Begumisa MG lecture notes series
Disease caused
Food poisoning, Toxic shock syndrome, Scalded skin
syndrome, pneumonia, meningitis, UTIs, Skin infection,
Osteomyelitis
Nosocomial infections (prosthetic) , UTIs,
UTIs in sexually active women
Pharyngitis, Scarlet fever &Rheumatic fever
Neonatal meningitis, pneumonia & sepsis
UTIs, Biliary tract infections, endocarditis
UTIs, Biliary tract infections, endocarditis
Pneumonia, Meningitis, sepsis, Otitis media
Dental caries, endocarditis, Brain abscesses
Gonorrhea, urethritis (men), gonococcal bacteremia,
Neonatal meningitis, meningitis in immunosuppressed
bronchopulmonary infections, Otitis media( children)
Diphtheria (mild sore throat with fever, myocarditis
Neonatal meningitis
Anthrax (Cutaneous, pulmonary & gastrointestinal
Food poisoning (nausea, vomiting & diarrhea)
Tetanus (muscle spasms, lockjaw, Risus sardonicus)
Food-borne botulinism, infant botulinism
Gaseous gangrene( Cellulitis/ wound infection)
Pseudomembranous enterocolitis (diarrhea)
Normal flora, Probiotic (produces Vitamin K & lactase)
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25.
Escherichia coli
Mixed rods
Gram-negative Bacilli
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
Klebsiella pneumoniae
Proteus mirabilis
Shigella dysenteriae
Salmonella typhi
Yersinia enterocolitica
Vibrio cholerae
Vibrio parahaemolyticus
Campylobacter jejuni
Helicobacter pylori
Pseudomonas aeruginosa
Encapsulated-thick caps
Rods
Long rods
Long rods
Long rods
Curved rods/ comma
Curved rods/ comma
Curved rods/ comma
Curved rods/ comma
Long rods
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
36.
37.
38.
39.
Pseudomonas cepacea
Bacteroides fragilis
Fusobacterium
Haemophilus influenzae
Long rods
Long rods
Long rods
Variable, small rods
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
40.
41.
42.
43.
44.
Haemophilus parainfluenza
Haemophilus ducreyi
Gardnerella vaginalis
Bordetella pertussis
Legionella pneumophila
Variable, small rods
Variable, small rods
Variable, small rods
Variable, small rods
Variable, small rods
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
45.
46.
47.
48.
49.
50.
51.
52.
Brucella melitensis
Brucella abortus
Brucella suis
Brucella canis
Yersinia pestis
Yersinia enterocolitica
Francisella tularensis
Goats
Cattle
Pigs
Dogs
Rods
Rods
Rods
Rods
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Gram-negative Bacilli
Begumisa MG lecture notes series
Zoonotic rods
(primarily of
animal origin )
Diarrhea, UTIs, sepsis, newborn meningitis, hospital
acquired pneumonia, hospital acquired sepsis,
Pneumonia, hospital acquired UTIs, sepsis
Urinary tract infection (UTIs), sepsis
Bloody diarrhea with mucus and pus
Enteric fever (typhoid & paratyphoid fever), sepsis
Acute enterocolitis with fever, diarrhea & abdominal pa
Cholera: severe diarrhea with rice water stools. No pus
Food poisoning, (diarrhea for 3 days)
Bloody/ secretory diarrhea
Duodenal ulcers, chronic gastritis
Pneumonia, Osteomyelitis, Bum wound infections,
UTIs, sepsis, endocarditis (in IV drug abusers)
Hospital acquired infections
Abscesses in the Gastrointestinal tract, pelvis & lungs
Necrotizing anaerobic pneumonia, Periodontal disease
Meningitis (children), Acute epiglottitis, septic arthritis
(infants), Sepsis, Pneumonia, Sinusitis, otitis media
Chancroid (painful genital ulcer)
Bacterial vaginitis (foul smelling viginal discharge)
Whooping cough
Legionnaires’ disease (pneumonia, fever and nonproductive cough), Pontiac fever (headache, fever….)
Brucellosis:
1. Undulating fever (fever peaks in the evening &
returns normal by the morning)
2. Weakness, loss of appetite
Bubonic plague, Pneumonic plague, Sepsis
Enterocolitis( focal ulcerations in ilium), Arthritis, Rash
Tularemia (ulceroglandular, pneumonia, typhoidal)
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