Pseudomonas aeruginosa is a motile, aerobic, gram-negative bacterium found in various moist environments and is known for its pathogenicity, particularly in immunocompromised individuals. It commonly causes hospital-acquired infections, including urinary tract infections and respiratory infections, and exhibits significant antibiotic resistance. Diagnosis relies on laboratory identification, and treatment often requires a combined antibiotic approach to mitigate resistance development.

1. PSEUDOMONAS
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DR.T.V.RAO MD
Dr. vikas saini
Senior Resident
Department of Microbiology
UCMS & GTB HOSPITAL

2. PSEUDOMONAS
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DR.T.V.RAO MD
• A large group of aerobic, non sporing gram
negative bacteria motile by polar flagella
• Found I nature water, soil, other moist
environments
• Some of them are pathogenic to plants
• Creation of new genera such as
Burkholderia. Stenotrophomnonas

3. - Widely distributed in
soil and water
- Gram negative rods
- Aerobic
- Motile
- Produce water-soluble
pigments
• Opportunistic
pathogens
GENERAL CHARACTERISTICS
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DR.T.V.RAO MD

4. MORPHOLOGY
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DR.T.V.RAO MD
• They are slender gram negative bacillus, 1.5 – 3 microbes x
0.5
microns
• Monoflgellar ?
• Non capsulated but many strains have mucoid slime layer
• Isolates from Cystic fibrosis patients have abundance of
extracellular polysaccharides composed of alginate polymers
• Escape the defence mechanisms by loose capsule in which micro
colonies of bacillus are enmeshed and protected from host
defences.

5. P. aeruginosa
Forms round colonies with a
fluorescent greenish color, sweet
odor, and -hemolysis.
Pyocyanin- nonfluorescent
bluish pigment;
pyoverdin- fluorescent greenish
pigment;
pyorubin, and pyomelanin
Some strains have a prominent
capsule (alginate).
Identification of P. aeruginosa is usually based on oxidase test
and its colonial morphology: b-hemolysis, the presence of
characteristic pigments and sweet odor, and growth at 42 oC.

6. CULTURAL CHARACTERS
DR.T.V.RAO MD 6
• Obligate aerobe, but grow anaerobically if nitrate is
available
• Growth occurs at wide range of temperatures 6-42 c
the optimum being 37 c
• Growth on ordinary media producing large opaque
irregular colonies with distinctive musty mawkish or
earthy smell.
• Iridescent patches with metallic sheen are seen in
cultures on nutrient agar.
• In broth forms dense turbidity with surface pellicle.

7. Characteristics of Pseudomonas aeruginosa
Motile (by single or multiple polar flagella)
gram-negative rods
Obligate (strict) aerobes (most strains)
Oxidase (usually) and catalase positive
Nonfermentative chemoheterotrophic
respiratory metabolism
Minimal nutritional reqts.; Many organic
compounds used as C and N sources, but
only a few carbohydrates by oxidative
metabolism
•Glucose used oxidatively
D•R.T.VL.RA tose negative on MacConkey’s agar

8. PIGMENT PRODUCTION
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DR.T.V.RAO MD
Some strains produce diffusible pigments:
•Pyocyanin (blue); fluorescein (yellow);
pyorubin (red)
P. aeruginosa produces characteristic
grape-like odor and blue-green pus &
colonies
Broad antibiotic resistance

9. BIOCHEMICAL REACTIONS
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DR.T.V.RAO MD
• Oxidative and Non fermentative
• Glucose is utilized oxidatively
• Indole, MR and VP and H2 S tests are
negative
• Catalase, Oxidase, and Arginine tests
are positive

10. TYPING AND IMPORTANCE
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DR.T.V.RAO MD
• Important cause of Hospital Infections
• Important for epidemiological purpose
• Serotyping
• Bacteriocins typing
• Pyocyanin
• Aeruginosin typing
• Restriction endonuclease typing with pulsed gel
electrophoresis

11. RESISTANCE
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DR.T.V.RAO MD
• Killed at 55oc in on 1 hour
• High resistance to chemical agents
• Resistance to quaternary ammonium
compounds.Chlorxylenol
• Resistant to Hexchlorophenes
• Grows also in antiseptic bottles
• Dettol as cetrimide as selective medium
• Sensitive to acids silver salts, beta glutaraldehyde

12. WHAT ANTIBIOTICS TO USE
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DR.T.V.RAO MD
• Aminoglycosides
• Gentamycin, Amikacin, Cephalosporins
• Cefotaxime. Ceftazidime. Ofloxacin,
• Piperacillin, ticarcillin
• Local application, colistin, polymyxin

13. PATHOGENICITY
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DR.T.V.RAO MD
• Blue pus
• Causing the nosocomial infection
• Suppurative otitis
• Localised and generalised infections
• Urinary tract infection after catheterization
• Iatrogenic meningitis
• Post tracheostomy pulmonary infections

14. P.
aeruginosa
Pathogenesis and Immunity
This organism is widely distributed in nature
and is commonly present in moist environments
in hospitals. It is pathogenic only when
introduced into areas devoid of normal
defenses, e.g.,
1.Disruption of mucous membrane and skin.
2.Usage of intravenous or urinary catheters.
3.Neutropenia (as in cancer therapy).

15. P.
aeruginosa
Pathogenesis
Antigenic structure,
enzymes, and toxins
Pili and nonpilus adhesins.
Capsule (alginate,
glycocalyx): seen in cultures
from patients with cystic
fibrosis.
LPS- endotoxin, multiple
immunotypes.
Pyocyanin: catalyzes
production of toxic forms of
oxygen that cause tissue
damage. It also induces IL-8
production. Pyoverdin: a
siderophore.
Proteases
Serine protease,
metalloprotease and alkaline
protease cause tissue damage
and help bacteria spread
Phospholipase C: a hemolysin
Exotoxin A: causes tissue
necrosis and is lethal for animals
(disrupts protein synthesis);
immunosuppressive.
Exoenzyme S and T: cytotoxic to
host cells.

16. PATHOGENESIS AND IMMUNITY
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DR.T.V.RAO MD
• P. aeruginosa can infect almost any
external site or organ.
• P. aeruginosa is invasive and toxigenic. It attaches
to and colonizes the mucous membrane or skin,
invade locally, and produces systemic diseases
and septicemia.
• P. aeruginosa is resistant to many antibiotics. It
becomes dominant when more susceptible
bacteria of the normal flora are suppressed.

17. • Septicaemia
• Endocarditis
• Ecthyma gangrenous
• Infantile diarrhoea
• Shanghai fever
• Disabling eye infections
• Survive with minimal
nutrients
CLINICAL PRESENTATIONS
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18. WHO IS MORE SUSCEPTIBLE TO
INFECTION
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DR.T.V.RAO MD
• This bacterium is of particular concern to
individuals with cystic fibrosis who are highly
susceptible to pseudomonas lung infections.
Pseudomonas aeruginosa is also of grave
concern to cancer and burn patients as well as
those people who are immunocompromised. The
case fatality rate for individuals infected with
Pseudomonas aeruginosa approaches 50
percent.

19. • Pseudomonas aeruginosa
is the most frequently
encountered lung pathogen
in patients with cystic
fibrosis (CF). Following
initial, often intermittent,
episodes of infection, it
becomes a permanently
established component of
the chronically infected lung
in more than 80% of
patients and confers an
adverse prognosis
PSEUDOMONAS AND CYSTIC FIBROSIS
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DR.T.V.RAO MD

20. • Respirators
• Endotracheal
tubes
• Can be Infected
• All equipment's
to be sterilized
INFECTION OF EQUIPMENT'S
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DR.T.V.RAO MD

21. PSEUDOMONAS AND URINARY TRACT
INFECTIONS
•Pseudomonal UTIs are usually hospital-acquired
and are associated with catheterization,
instrumentation, and surgery. These infections can
involve the urinary tract through an ascending
infection or through bacteriuic spread. In addition,
these infections are a frequent source of
bacteraemia. No specific characteristics distinguish
this type of infection from other forms of UTI.
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22. • Toxic extracellular products
in culture filtrates
• Exotoxin A and S
• Exotoxin A acts as NADase
resembling Diphtheria toxin
• Proteases,elastatese
hemolysins and enterotoxin
• Slime layer and Biofilms
TOXINS AND ENZYMES IN
PSEUDOMONAS
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23. PSEUDOMONAS AERUGINOSA AN
IMPORTANT OPPORTUNISTIC PATHOGEN
•Pseudomonas aeruginosa is an opportunistic
pathogen, meaning that it exploits some break in
the host defences to initiate an infection. In fact,
Pseudomonas aeruginosa is the epitome of an
opportunistic pathogen of humans. The bacterium
almost never infects uncompromised tissues, yet
there is hardly any tissue that it cannot infect if the
tissue defences are compromised in some manner
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DR.T.V.RAO MD

24. P.AEROGINOSA IS AN OPPORTUNISTIC
PATHOGEN
•P,aeroginosa is an opportunistic pathogen. It
rarely causes disease in healthy persons. In
most cases of infection, the integrity of a physical
barrier to infection (eg, skin, mucous membrane)
is lost or an underlying immune deficiency (eg,
neutropenia, immunosuppression) is present.
Adding to its pathogenicity, this bacterium has
minimal nutritional requirements and can tolerate
a wide variety of physical conditions
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DR.T.V.RAO MD

25. PSEUDOMONAS PROMINENT HOSPITAL
ACQUIRED INFECTIONS
•It causes urinary tract infections, respiratory
system infections, dermatitis, soft tissue
infections, bacteraemia, bone and joint
infections, gastrointestinal infections and a
variety of systemic infections, particularly in
patients with severe burns and in cancer
and AIDS patients who are
immunosuppressed.
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26. DIAGNOSIS OF P.AEROGINOSA
INFECTION
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• Diagnosis of P,aeroginosa infection depends upon
isolation and laboratory identification of the bacterium.
It grows well on most laboratory media and commonly
is isolated on blood agar or eosin-methylthionine blue
agar. It is identified on the basis of its Gram
morphology, inability to ferment lactose, a positive
oxidase reaction, its fruity odour, and its ability to grow
at 42°C. Fluorescence under ultraviolet light is helpful
in early identification of P.s aeruginosa colonies.
Fluorescence is also used to suggest the presence of
P. aeruginosa in wounds.

27. Pseudomonas sp. develop as easily
distinguishable blue-green coloured
colonies, clearly visible under normal
lighting conditions. Other bacterial
species are inhibited or give
colourless colonies. Pseudomonas
aeruginosa, Pseudomonas
fluorescens, Pseudomonas putida
and Pseudomonas fragilis all give
typical blue-green colony colouration
and can be studied directly by
serotyping or biochemical methods.
IDENTIFICATION WITH CHROMAGAR
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DR.T.V.RAO MD

28. LABORATORY IDENTIFICATION OF
DIAGNOSIS OF P.AEROGINOSA INFECTIONS
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DR.T.V.RAO MD
• Diagnosis of P. aeruginosa infection depends upon
isolation and laboratory identification of the bacterium. It
grows well on most laboratory media and commonly is
isolated on blood agar or eosin-methylthionine blue agar.
It is identified on the basis of its Gram morphology,
inability to ferment lactose, a positive oxidase reaction,
its fruity odour, and its ability to grow at 42° C.
Fluorescence under ultraviolet light is helpful in early
identification of P. aeruginosa colonies and may also
help identify its presence in wounds.

29. TREATING PSEUDOMONAS INFECTIONS
•Combined antibiotic therapy is generally
required to avoid resistance that develops
rapidly when single drugs are employed.
Avoid using inappropriate broad-spectrum
antibiotics, which can suppress the normal
flora and permit overgrowth of resistant
pseudomonads.
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DR.T.V.RAO MD

30. PSEUDOMONAS AERUGINOSA A RESISTANT
PATHOGEN
•Pseudomonas aeruginosa is frequently resistant
to many commonly used antibiotics. Although many
strains are susceptible to gentamicin, tobramycin,
colistin, and amikacin, resistant forms have
developed. The combination of gentamicin and
carbenicillin is frequently used to treat severe
Pseudomonas infections. Several types of vaccines
are being tested, but none is currently available for
general use.
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31. P.
aeruginosa
Prevention and Control
Pseudomonas spp. normally inhabit soil, water, and vegetation
and can be isolated from the skin, throat, and stool of healthy
persons.
Spread is mainly via contaminated sterile equipment's and cross-
contamination of patients by medical personnel.
High risk population: patients receiving broad-spectrum
antibiotics, with leukemia, burns, cystic fibrosis, and
immunosuppression.
Methods for control of infection are similar to those for other
nosocomial pathogens. Special attention should be paid to sinks,
water baths, showers, hot tubs, and other wet areas.

32. BURKHOLDERIA
B. mallei, B. pseudomallei, B. cepacia
B. mallei – glanders/horses, mules and asses
Loeffler and Schutz (1882)
Natural disease – horses – glanders – farcy
Glanders – respiratory system – nasal septum
nodules – ulcers, catarrhal discharge

33. B. MALLEI
Farcy – lymph vessels and nodes – hard cords
Human – occupational – ostlers, grooms,
veterinarians
Mode of infection – contact discharges animal
lymphangitis, pyemia – multiple secondary foci
different parts of body – large, no bacilli
Acute glanders – fever, mucopurulent nasal
discharge, severe prostration – fatal

34. LABORATORY DIAGNOSIS
Microscopy
Culture
Samples – lesions
Microscopy – GNB 2–5 ǔ x 0.5 ǔ – irregular
staining, beaded appearance
Culture – ordinary media – translucent yellow
colonies

35. B. PSEUDOMALLEI
Melioidosis
Whitmore’s bacillus, Actinobacillus whitmori
Melis – disease – asses, eidos – resemblance
Whitmore and Krishnaswami (1912) – Rangoon
Whitmore – isolated (1913)

36. PATHOGENESIS
Meliodosis – animals, saprophyte
Human infection – soil, H2O, contact skin abrasions
Ingestion – contaminated particles
Asymptomatic infection, abscesses RE/liver, spleen
Motile, liquifies gelatin, utilises sugars – acid
thermolabile exotoxins – lethal necrotising

37. CLINICAL PICTURE – HUMANS
Acute septicemia
Subacute typhoid
Pneumonia and hemoptysis – TB
Chronic – caseus/suppurative foci and abscess
– subcutaneous tissue, bones, internal organs

38. LABORATORY DIAGNOSIS
Samples – exudate, sputum, pus, blood, urine
Microscopy – irregular safety pin
Isolation – ordinary media
Serology – ELISA, indirect hemagglutination – PCR
Rx – ceftazidime, cotrimoxazole, tetracycline
Prolonged Rx

39. B. CEPACIA
Cepacia – Latin – onion
Onion rot
Hospital acquired infection – opportunistic
pathogen
Cystic fibrosis or chronic granulomatous
Oxidase +ve, mannitol, sorbitol, sucrose –
acidified
Resistance – inherent, most antibiotics

40. STENOTROPHOMONAS MALTOPHILA
P. multophilia
Free-living GNB oxidase – negative
Opportunistic pathogen
Bacteremia, meningitis, pneumonia, UTI
Wound infection, hospital infection –
contaminated disinfectants, respiratory
monitors
Rx – trimethoprim – sulphomethoxazole