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1- Gram Negative cocci
Antimicrobial
sensitivity
Biochemical
tests
culture
Microscopic
examination
Laboratory
diagnosis
pathogenicity
Bacteria
penicillin
1- Oxidase + Ve
2- Utilize :
Glucosemaltose
Chocolate blood
agar (
transparent or
grey colonies
incubation in
CO2
Gram –Ve
dipiococci
( intracellular in
pus cells )
CSF
Pyogenic
meningitides
( headachevomiting- stiff neck
)
Niesseria
meningitidis
Resistant to
penicillin
1- Oxidase + Ve
2- Utilize :
glucose only
1- Modified
New York City (
MNYC)
2- Thayer
martin
( transparent or
grey colonies )
Gram –Ve
dipiococci
( intracellular in
pus cells )
Urethal &
cervical
exudates- urine
– eye swab
Gonorrhoeae
( sexual
transmitted) –
acute conjunctivitis
in infants of
mother with
Gonorrhoeae
Niesseria
gonorrhoeae
2- Gram Positive cocci
Antimicrobial
sensitivity
Biochemical
tests
culture
Microscopic
examination
Laboratory
diagnosis
pathogenicity
Bacteria
1- All
staphylococci
are catalase +
Ve
2- coagulase
+Ve
3- DNAase +Ve
4- liquefy gel
5- hemolyse
blood
1-Blood agar
( yellow to cream colonies
some strains betahaemolytic
2- macConkey agar (small
deep pink due to lactose
fermentation )
3- Mannitol salt agar agar (
yellow due to Mannitol
fermentation )
4- nutrient agar
( golden yellow )
Gram +Ve in
cluster (
grape like
cluser )
Pus –skin
swab sputum – CSF
– blood –
Faeces –
vomit in food
poisoning
Pneumonia –
impetigo – wound
infection –
osteomyelitis –
food poisoning
due to
enterotoxins
Normal flora in
40% of health
people
Staphylococcus
aureus
Penicillin &
Erythromycin
1- sensitive to
Bacitracin disk
2- antistreptolysin O (
ASO )
1- Blood agar ( small white
beta- haemolytic colonies )
2-Crystal violet blood agar
( selective for S. pyoggenes
)
3- macConkey agar
( no growth )
Gram +Ve in
chains,pairs
– some
strains are
capsulated
Throat swab –
pus swab blood
Sore throat (
tonsillitis,
pharyngitis ) –
scarlet fever –
otitis media –
impetigo –
rhrumatic fever –
glomerulonephritis
Normal flora in
Streptococc
us pyogenes
( Group A )
upper respiratory
tract
Penicillin &
Erythromycin
1- Hippurate
hydrolysis +Ve
by adding ferric
chloride give
heavy brown
precipitate
2- CAMP
( extracellular
protein
produced by S.
agalactiae
enhance
haemolysis
with S. aureus
beta- lysin
1- Blood agar ( grey
,mucoid beta- hemolytic
colonies )
2- kanamycin blood agar
( selective for S. agalactiae
)
3- MacConkey agar
Gram +Ve in
chains,pairs
– some
strains are
capsulated
CSF – ear
swab –
vaginal swab blood
Septic abortion –
gynecological
sepsis – UTI –
neonatal
septicemia –
meningitis –
normal flora in
femal genital tract
Strepotococ
cus
agalactiae
( Group B )
Penicillin ,
Erythromycin
& cotrimoxazole
1- Bile solubility
test (clear
turbidity)
2- sensitive to
optochin disk
1- Blood agar
( mucoid alpha- haemolytic
2- chocolate agar with CO2
Gram +Ve
elongated
diplococcus
– short
chains
capsulated
Sputum –
exudatesblood - CSF
Lobar pneumonia
– bronchitis –
meningitis –
conjunctivitis –
normal flora in
upper respiratory
tract
Strepotococ
cus
pneumoniae
Gram +Ve in
chains
Endocarditisdental caries –
bacteraemia
Normal flora in
upper respiratory
tract
Strepotococ
cus
Viridians
species
Haemolysis
Sensitivity to
Bacitracin
CAMP
Aesculin Hydrolysis
Streptococcus pyogenes
Group A
Beta
sensitive
negative
negative
Strepotococcus agalactiae
Group B
Beta
resistant
positive
negative
Strepotococcus Fecalis
Group D
Non haemolytic
resistant
negative
positive
Sensitive to
Ampicillin &
resistant to
Cephalospori
n
1- Aesculin
hydrolysis +Ve
( Black- brown
color )
2- litmust Milk
decolorization
( reduce litmus
milk & give pale
yellow color)
3- growth in
6.5% NaCl &
40% bile
Grow over wide
temperature 10-45 C
1- Blood agar
2- macConkey agar ( small
pink colonies due to lactose
fermentation)
3- CLED( small yellow
colonies due to lactose
fermentation)
Gram +Ve in
chains,pairs
Site of
infection
UTI – biliary tract –
wound- ulcers –
endocarditismeningitis –
normal flora in
vagina & intestinal
tract
Strepotococcus
Fecalis
( Enterococcus )
( Group D )
3- Aerobic and facultative anaerobic Gram negative Bacilli
Biochemical tests
culture
Microscopic
examination
Laboratory
diagnosis
pathogenicity
Bacteria
1- indole :+ Ve
2- motility : +Ve
3- MR : +Ve
4- nitrare : +Ve
IMVC
++-1- Blood agar ( some strains are haemolytic
2- MacConkey : pink colonies due to lactose
fermentation
3- CLED : yellow colonies due to lactose
fermentation
4- XLD : yellow color
5- DCA : growth inhibited
6- EMB : black colonies with metallic shine
6- KIA : yellow butt – yellow slant produce
Acid & gas
Gram –Ve
motile rods
Urine – pus –
faeces – CSF blood
UTI – wound
infection –
meningitis –
bacteraemia in
neonates - diarrhea
E. coli
1- citrate : +Ve
2- urease: +Ve
3- MR: +Ve/-Ve
4- Vp : +Ve/-Ve
5- nitrate : +Ve
IMVC
--++
1- blood agar : large grey white mucoid
colonies
2- macConkey : mucoid pink colonies due to
lactose fermentation
3- CLED : yellow colonies due to lactose
fermentation
6- KIA : yellow butt – yellow slant produce
Acid & gas
Gram –Ve non
motile
capsulated
rods
Urine – pus –
sputum
Chest infection
(bronchopneumonia
– abscesses ) - UTI
Klebsiella
pneumonia
1- urease : +Ve
2- PPA: +ve
3- motility : +Ve
4- Citrate : +Ve
1-bloodagar : fishy odour – swarming
2- MacConkey & XLD: swarming inhibited
due to bile salts
3- CLED : swarming inhibited due electrolyte
deficient
4- KIA : yellow butt – red slant produce gas &
H2S
Gram -Ve
pleomorphic
rods actively
motile
Urinr – pus
UTI ( Alkaline ) –
abdominal & wound
infection
Proteus
mirabilis
1-KSA :
a- Pink ( alkaline )
slope & yellow (
acid ) butt
indicating
fermentation of
glucose not
lactose
b- produce gas
except S. typhi
c-produce H2S
except S.
paratyphi A
2- citrate : +Ve
except S.
paratyphi A
3- MR: +Ve
IMVC
-+-+
4- Widal test
(O&H
antibodies )
1-blood culture ( blood Columbia agar
- diphasic medium )
2- blood agar ( subculture ):grey- white some
strains appear mucoid
3- XLD(selective media ):pink color with black
center due to H2S
4- MacConkey & DCA : pale color with black
center
Gram -Ve rods
actively motile
– non- sporing
except S. typhi
1- for enteric
fever ( bloodfaeces- urine )
2- for
enterocolitis
( faeces –
blood )
3- for
bacteraemia
( blood )
1- Enteric fever
( typhoid &
paratyphoid )
2- enterocolitis
3- Bacteraemia
salmonella
1-KIA : pink
(alkaline ) slope &
yellow( acid ) butt
indicating
fermentation of
glucose not
lactose – no H2S
Selective media
1-XLD: red-pink colonies without black center
2-MacConkey & DCA: pale color due to non
lactose fermentation –
S. sonnei produce pink color on prolonged
incubation
Gram -Ve
1-fresh faecal
specimen
2-transport
medium for
delayed
faecal
specimen
Bacillary dysentery
or shigellosistransmission by
faecal oral route
Shigella
production
2- MR: +ve
1-Catalase : +ve
oxidase –ve
urea, indol -ve
2- MR: +ve
Optimum temp.
27C
( culture should be
incubated at room temp.)
1-blood agar: small shiny non haemolytic
colonies after 24- 48hr.
2-macConkey :very small translucent pink
after 24-48hr. ( non lactose fermentation but
it take up red dye of indicator in the medium
)
Small Gram –
Ve
coccobacillus
–
capsulated
show
bipolar
staining
with
methylene
blue, Giemsa
Bubo
aspiratessputumblood
Plague
( Bubonic –
pneumonic –
septicaemic
Transimission : 1infected fleas
(Xenopsylla ) from
rats or domestic
animals
( dogs,cats )
2- inhaling
organisms in
airborn droplets
Yersinia
pestis
1- oxidase : +Ve
2- Citrate : + Ve
3- oxidationfermentation test
:
Yellow color ( in
oxidative opened
tube )
1- blood agar: large flat spreading colonies
often are haemolytic
2-macConkey : pale color due to NLF
3- CLED : geen color due to NLF
3- KIA : pink-red slope with metallic
appearance – pink-red butt
Gram –Ve
motile
rod
some strains
are
capsulated-
obligatory
aerobic
Produce
pigment
a- blue geen
b-yellow green
Pus – urinesputumeffusions blood
Opportunistic
hospital acquired
infection
1-skin infection (
burn, wound,ulcers
)
2- UTI ( following
catherization )
3- Respiratory tract
infection
4- ear infection
(otitis externa)
5- eye infection
Pseudomon
as
aeruginosa
1- oxidase : +Ve
2-indole : + Ve
Grow best in alkaline pH
1- TCBS ( selective media ):sucrose
fermenting yellow colonies
2- KIA: red slope and yellow butt
3- blood agar : often produce beta haemolytic
colonies
Gram –Ve
curved rods
motile ( with
single
flagellum at
one end )
Faecal
specimen
rice water stool
( enterotoxin
activates adenylate
cyclase within
intestine result in
secretion of large
fluid & electrolytes
transmission by
faecal oral routes
Vibrio
cholera
1-catalase : +Ve
2-oxidase : +Ve
3- urease : +Ve
B rucella is difficult to isolate & it more
isolated from blood in acute brucellosis
during time of fever
1- tryptone soya (tryptic soy )diphasic
medium :
B. abortus requiring CO2 & keep for weeks
with subculture every few days
2- serum dextrose agar :
smooth,mucoid,rough colony
3- B. abortus & B. suis produce H2S
Small Gram –
Ve coccobacilli
or short rods
1-Blood or
bone marrow
in acute stage
2- serum for
serology
Brucellosis or
undulant fever (
zoonotic disease )
Brucella
1-Oxidase:+Ve
2-Nitrate
reduction : +Ve
Grow best moist CO2 & media contain
haemin & NAD
( factor X ) or NADP ( factor V )
1-chocolate agar
2- satellitism test : S. aureus in blood agar
produce factor V & haemin released by
haemolysin enhance growth of H. influenza
Small Gram –
Ve
coccobacillus
or short rod
CSFnasopharynge
al specimens
– pus – blood
( specimens
must be
cultured as
soon as
possible &
not
refrigerated )
1-pyogenic
(purulent )
meningitis in young
children below 5
years old
2- pneumonia (adult
)
3- acute epiglottitis
( fatal airway
obstruction )
4- cellulitis
Haemophilu
s influenzae
Oxidase : +Ve
Strict aerobic ( specimens must be cultured
as soon as possible )
1- Charcoal cephalexin blood agar ( selective
& enrichment media ) : incubated for 2-6 days
in CO2 moist aerobically produce small
mercury like mucoid colonies
Small
capsulated
Gram –Ve
cocobacillus
( singly or in
chains )
Nasopharyng
eal secretion
collected by
aspiration
Whooping cough
( infection of
mucosa of upper
respiratory tract )
Bordetella
pertussis
1- oxidase : +Ve
2- catalase : +Ve
3- Na hippurate
hydrolysis : +Ve
Strictly microaerophilic reduired (10% CO2 ) –
thermophilic ( 36 – 43 c )
1- Blood agar : non haemolytic droplet like
colonies
2- Butzler virion medium : selective media
Spirally curved
motile G-Ve ,
with faecal
smear (1%
basic fuchsin)
Appear linked
to wings of
gulls or "S" or
comma shape
Diarrheal
feces contain
blood ,pus,
mucus
Enteritis – watery
diarrhea or
dysentery
( main source are
unpasteurized milk
– fecal oral route )
campylobac
ter
1- oxidase : +Ve
2- catalase : +Ve
3- urease : +Ve
Microaerophilic required CO2 ( grow slowly
forming grey translucent colonies within 3-7
days
1- blood agar : slightly beta – haemolytic
Small spiral or
S shape G-Ve
Gastric biopsy
– stool serum for
serology
Chronic gastritis
lead to ulceration &
may cause gastric
carcinoma
Helicobacter
pylori
4- Anaerobic Gram Negative Bacteria
1- They ferment
wide ranges of
carbohydrates
( glucose –
maltose – lactose
)
2- Aesculin
hydrolysis : +Ve
3- can grow in 20
% Bile tolerant
test
Strict anaerobic they fastidious they require
media containing blood & menadione ( vit.
K)
1- blood agar ; grey , non haemolytic
colonies
G-Ve rods
pleomorophic
Pus –
exudatesinfection
tissue - blood
Abdominal infection
( particularly
following surgery ) –
peritonitis –
gynaecological
infections (
puerperal sepsis )lung , cerebral
abscesses – soft
tissue infections
Bacteroides
fragilis