pseudomonas by akram.ppt - mymensingh medical college file/pseudomonas by akram.pdf ·...

PSEUDOMONASPSEUDOMONAS

Prof. Md. Akram Hossain Prof. Md. Akram Hossain

11Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain, PseudomonasPseudomonas

1. What is the clinical importance of Pseudomonas?

2. What are the salient cultural & biochemical featuues of Pseudomonas?

3. Write down the pathogensis of Ps. Aeroginousa?

4. Can pseudomonas cause infection in healthy individuals?

5. What are the predisposing factors for Pseudomonas

Review questionsReview questions

5. What are the predisposing factors for Pseudomonas infections?

6. What are the virulence factors of pseudomonas?

7. What is the mechanism of action of Exotoxin A?

8. Name some pigment producing bacteria?

9. Enumerate the diseases caused by Ps. Aeroginousa.

10. How pseudomonas differs from Enterobacteriaceae?22Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain,

PseudomonasPseudomonas

�� PseudomonasPseudomonas isis oftenoften encounteredencountered inin hospitalhospitalandand clinicalclinical workwork becausebecause itit isis aa majormajor causecause ofofhospitalhospital acquiredacquired (nosocomal)(nosocomal) infectionsinfections..

�� ItsIts mainmain targetstargets areare immunocompromisedimmunocompromisedindividuals,individuals, burnburn victims,victims, andand individualsindividuals ononrespiratorsrespirators oror withwith indwellingindwelling catheterscatheters..

�� Additionally,Additionally, thesethese pathogenspathogens colonizecolonize thethe lungslungsofof cysticcystic fibrosisfibrosis patients,patients, increasingincreasing thethe mortalitymortalityraterate ofof individualsindividuals withwith thethe diseasedisease..raterate ofof individualsindividuals withwith thethe diseasedisease..

�� InfectionInfection cancan occuroccur atat manymany sitessites andand cancan leadlead totourinaryurinary tracttract infections,infections, sepsis,sepsis, pneumonia,pneumonia,pharyngitis,pharyngitis, andand aa lotlot ofof otherother problemsproblems..

�� RarelyRarely causecause ofof infectioninfection inin healthyhealthy individualsindividuals..ItsIts nonnon--invasiveinvasive naturenature limitslimits itsits pathogenicpathogeniccapabilitiescapabilities..


�� PseudomonadsPseudomonads areare motile,motile, GramGram--negativenegative rodsrods thatthat utilizeutilize glucoseglucoseoxidativelyoxidatively..

�� TheseThese bacteriabacteria areare clinicallyclinically importantimportantTheseThese bacteriabacteria areare clinicallyclinically importantimportantbecausebecause

•• theythey areare resistantresistant toto mostmost antibioticsantibiotics

•• theythey areare capablecapable ofof survivingsurviving inin conditionsconditionsthatthat fewfew otherother organismsorganisms cancan toleratetolerate..

�� TheyThey alsoalso produceproduce aa slimeslime layerlayer thatthat isisresistantresistant toto phagocytosisphagocytosis..


TaxonomyTaxonomy�� Family Family –– PsedomonadeceaePsedomonadeceae

�� Important memebrsImportant memebrs

•• PseudomonasPseudomonas aeruginosaaeruginosa,,

•• PP. . alcaligenesalcaligenes, ,

•• PP. . chlororaphischlororaphis,,•• PP. . chlororaphischlororaphis,,

•• PP. . fluorescensfluorescens, ,

•• PP. . luteolaluteola. .

•• PP. . mendocinamendocina, ,

•• PP. . monteiliimonteilii,,

•• PP. . pseudalcaligenespseudalcaligenes, ,

•• PP. . putidaputida, , PP. . stutzeristutzeri55Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain,


General CharacteristicsGeneral Characteristics

�� GramGram--negativenegative•• Obligate AerobeObligate Aerobe

•• motilemotile

�� Widely distributed in soil and water, human gut (10%)Widely distributed in soil and water, human gut (10%)•• diverse metabolic capabilitiesdiverse metabolic capabilities

•• many can grow in distilled water to >10many can grow in distilled water to >1066 per mlper ml

•• growth on wide range of carbon sourcesgrowth on wide range of carbon sources

•• readily available for nosocomial infectionsreadily available for nosocomial infections

�� Susceptible to drying, airborne spread less likelySusceptible to drying, airborne spread less likely66Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain,


Pseudomonas aeruginosaPseudomonas aeruginosa

�� PseudomonasPseudomonas aeruginosaaeruginosa isis thetheepitomeepitome ofof anan opportunisticopportunisticpathogenpathogen ofof humanshumans..

�� TheThe bacteriumbacterium almostalmost nevernever infectsinfects�� TheThe bacteriumbacterium almostalmost nevernever infectsinfectsuncompromiseduncompromised tissues,tissues, yetyet therethere isishardlyhardly anyany tissuetissue thatthat itit cannotcannotinfect,infect, ifif thethe tissuetissue defensesdefenses arearecompromisedcompromised inin somesome mannermanner..


P. aeruginosaP. aeruginosa

�� PseudomonasPseudomonas aeruginosaaeruginosa isis thethe mostmostfrequentlyfrequently isolatedisolated nonnon--fermenterfermenter ininthethe laboratorylaboratory.. ItIt hashas severalseveralfeaturesfeatures thatthat distinguishdistinguish itit fromfromfeaturesfeatures thatthat distinguishdistinguish itit fromfromotherother speciesspecies ofof PseudomonasPseudomonas::

•• ItIt cancan growgrow atat 4242 degreesdegrees celsiuscelsius

•• ProducesProduces aa bluishbluish pigmentpigment (pyocyanin)(pyocyanin)andand aa greenishgreenish pigmentpigment

•• CharacteristicCharacteristic fruityfruity odorodor


Important cultural propertiesImportant cultural properties

�� Oxidase + Oxidase +

�� BetaBeta--hemolytic hemolytic

�� Characteristic odorCharacteristic odor�� Characteristic odorCharacteristic odor

and color and color

�� Motile Motile


PathogenesisPathogenesis

�� Disease rare in healthy individualsDisease rare in healthy individuals•• chronic external otitischronic external otitis

�� Disease most common in those withDisease most common in those with•• natural immunologic deficiencynatural immunologic deficiency

•• immunosuppressive therapyimmunosuppressive therapy•• immunosuppressive therapyimmunosuppressive therapy

•• burnsburns

•• chronic pulmonary disease (cystic fibrosis)chronic pulmonary disease (cystic fibrosis)

•• IV narcotic useIV narcotic use

•• renal dialysisrenal dialysis

�� Most common sites of infection: urinary tract, burnsMost common sites of infection: urinary tract, burns1010Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain,


Pathogenesis...Pathogenesis...

�� Septicemia, abscessesSepticemia, abscesses

�� Corneal infectionsCorneal infections

�� MeningitisMeningitis�� MeningitisMeningitis

�� BronchopneumoniaBronchopneumonia

�� Subacute endocarditisSubacute endocarditis


List of Disease producedList of Disease produced

1.1. EndocarditisEndocarditis. . 2.2. Respiratory infectionsRespiratory infections. . 3.3. BacteremiaBacteremia.. .. 4.4. Central Nervous System infectionsCentral Nervous System infections..5.5. Ear infections including external otitisEar infections including external otitis. .

Eye infectionsEye infections..6.6. Eye infectionsEye infections..7.7. Bone and joint infectionsBone and joint infections. . 8.8. Urinary tract infectionsUrinary tract infections..9.9. Gastrointestinal infectionsGastrointestinal infections.. .. 10.10. Skin and soft tissue infections, including Skin and soft tissue infections, including

wound infections, pyoderma and wound infections, pyoderma and dermatitisdermatitis. .


Details of DiseaseDetails of Disease

1.1. EndocarditisEndocarditis.. Pseudomonas aeruginosa infectsheart valves of IV drug users and prosthetic heartvalves. The organism establishes itself on theendocardium by direct invasion from the bloodstream.

2. Respiratory infections. Respiratory infectionscaused by Pseudomonas aeruginosa occur almostcaused by Pseudomonas aeruginosa occur almostexclusively in individuals with a compromisedlower respiratory tract or a compromised systemicdefense mechanism. Primary pneumonia occurs inpatients with chronic lung disease and congestiveheart failure. Bacteremic pneumonia commonlyoccurs in neutropenic cancer patients undergoingchemotherapy. Lower respiratory tract colonizationof cystic fibrosis patients by mucoid strains ofPseudomonas aeruginosa is common and difficult,if not impossible, to treat.

..


Details of Disease...Details of Disease...

� Bacteremia. Pseudomonas aeruginosa causesbacteremia primarily in immunocompromisedpatients. Predisposing conditions includehematologic malignancies, immunodeficiencyrelating to AIDS, neutropenia, diabetes mellitus,and severe burns. Most Pseudomonasbacteremia is acquired in hospitals and nursinghomes. Pseudomonas accounts for about 25homes. Pseudomonas accounts for about 25percent of all hospital acquired Gram-negativebacteremias.

� Central Nervous System infections.Pseudomonas aeruginosa causes meningitis andbrain abscesses. The organism invades the CNSfrom a contiguous structure such as the innerear or paranasal sinus, or is inoculated directlyby means of head trauma, surgery or invasivediagnostic procedures, or spreads from a distantsite of infection such as the urinary tract. 1414Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain,


� Ear infections including external otitis.Pseudomonas aeruginosa is the predominant bacterialpathogen in some cases of external otitis including"swimmer's ear". The bacterium is infrequently found inthe normal ear, but often inhabits the external auditorycanal in association with injury, maceration,inflammation, or simply wet and humid conditions.

� Eye infections. Pseudomonas aeruginosa can causedevastating infections in the human eye. It is one of the

Details of Disease...Details of Disease...

devastating infections in the human eye. It is one of themost common causes of bacterial keratitis, and hasbeen isolated as the etiologic agent of neonatalophthalmia. Pseudomonas can colonize the ocularepithelium by means of a fimbrial attachment to sialicacid receptors. If the defenses of the environment arecompromised in any way the bacterium can proliferaterapidly and, through the production of enzymes such aselastase, alkaline protease and exotoxin A, cause arapidly destructive infection that can lead to loss of theentire eye.



� Bone and joint infections.

• Pseudomonas infections of bones and jointsresult from direct inoculation of the bacteria orthe hematogenous spread of the bacteria fromother primary sites of infection. Blood-borneinfections are most often seen in IV drugusers, and in conjunction with urinary tract orpelvic infections. Pseudomonas aeruginosa haspelvic infections. Pseudomonas aeruginosa hasa particular tropism for fibrocartilagenousjoints of the axial skeleton. Pseudomonasaeruginosa causes chronic contiguousosteomyelitis, usually resulting from directinoculation of bone, and is the most commonpathogen implicated in osteochondritis afterpuncture wounds of the foot.


� Urinary tract infections.• Urinary tract infections (UTI) caused byPseudomonas aeruginosa are usually hospital-acquired and related to urinary tractcatheterization, instrumentation or surgery.Pseudomonas aeruginosa is the third leadingcause of hospital-acquired UTIs, accountingfor about 12 percent of all infections of this


cause of hospital-acquired UTIs, accountingfor about 12 percent of all infections of thistype. The bacterium appears to be among themost adherent of common urinary pathogensto the bladder uroepithelium. As in the case ofE. coli urinary tract infection can occur via anascending or descending route. In addition,Pseudomonas can invade the bloodstreamfrom the urinary tract, and this is the sourceof nearly 40 percent of Pseudomonasbacteremias.


Gastrointestinal infections.• Pseudomonas aeruginosa can produce

disease in any part of the gastrointestinaltract from the oropharynx to the rectum. Asin other forms of Pseudomonas disease,those involving the GI tract occur primarilyin immunocompromised individuals. The


those involving the GI tract occur primarilyin immunocompromised individuals. Theorganism has been implicated in perirectalinfections, pediatric diarrhea, typicalgastroenteritis, and necrotizingenterocolitis. The GI tract is also animportant portal of entry in Pseudomonassepticemia.

� .1818Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain,


� Skin and soft tissue infections,including wound infections, pyodermaand dermatitis.• Pseudomonas aeruginosa can cause a variety

of skin infections, both localized and diffuse.The common predisposing factors arebreakdown of the integument which may result


breakdown of the integument which may resultfrom burns, trauma or dermatitis; highmoisture conditions such as those found in theear of swimmers and the toe webs of athletesand combat troops, in the perineal region andunder diapers of infants, and on the skin ofwhirlpool and hot tub users; neutropenia; andAIDS. Pseudomonas has also been implicatedin folliculitis and unmanageable forms of acnevulgaris. 1919Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain,


Virulence factorsVirulence factors

1.1. Adhesins Adhesins

2.2. Invasins Invasins

3.3. Motility/chemotaxis Motility/chemotaxis

4.4. Toxins Toxins Toxins Toxins

5.5. Antiphagocytic surface properties Antiphagocytic surface properties

6.6. Defense against serum bactericidal Defense against serum bactericidal reaction reaction

7.7. Defense against immune responses Defense against immune responses

8.8. Genetic attributes Genetic attributes

9.9. Ecologic criteria Ecologic criteria 2020Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain, PseudomonasPseudomonas

�� AdhesinsAdhesins

•• fimbriae (Nfimbriae (N--methylmethyl--phenylalanine pili) phenylalanine pili)

•• polysaccharide capsule (glycocalyx) polysaccharide capsule (glycocalyx)

•• alginate slime (biofilm)alginate slime (biofilm)

�� InvasinsInvasins

Virulence factors…

InvasinsInvasins

•• elastase elastase

•• alkaline protease alkaline protease

•• hemolysins (phospholipase and lecithinase) hemolysins (phospholipase and lecithinase)

•• cytotoxin (leukocidin) cytotoxin (leukocidin)

•• siderophores and siderophore uptake siderophores and siderophore uptake systemssystems

•• pyocyanin diffusible pigmentpyocyanin diffusible pigment 2121Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain, PseudomonasPseudomonas

�� Motility/chemotaxisMotility/chemotaxis

•• flagellaflagella

�� ToxinsToxins

•• Exoenzyme S Exoenzyme S

•• Exotoxin A Exotoxin A


•• Exotoxin A Exotoxin A

•• LipopolysaccharideLipopolysaccharide

�� Antiphagocytic surface Antiphagocytic surface propertiesproperties

•• capsules, capsules,

•• slime layers slime layers

•• LPSLPS2222Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain,


�� Defense against serum Defense against serum

bactericidal reactionbactericidal reaction

•• slime layers, capsules slime layers, capsules

•• LPS LPS

•• protease enzymesprotease enzymes


•• protease enzymesprotease enzymes

�� Defense against immune Defense against immune

responsesresponses

•• capsules, slime layers capsules, slime layers

•• protease enzymesprotease enzymes2323Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain,


�� Genetic attributesGenetic attributes

•• genetic exchange by transduction and genetic exchange by transduction and conjugation conjugation

•• inherent (natural) drug resistance inherent (natural) drug resistance R factors and drug resistance R factors and drug resistance


R factors and drug resistance R factors and drug resistance plasmidsplasmids

�� Ecologic criteriaEcologic criteria

•• adaptability to minimal nutritional adaptability to minimal nutritional requirements requirements

•• metabolic diversity metabolic diversity

•• widespread occurrence in a variety of widespread occurrence in a variety of habitatshabitats


�� Alginate (polysaccharide)Alginate (polysaccharide)•• viscous gel around bacteriaviscous gel around bacteria

•• coating may protect from coating may protect from

Capsule/ slim layer

•• coating may protect from coating may protect from phagocytosis in lung infectionsphagocytosis in lung infections

•• only produces septicemia in only produces septicemia in patients with neutropeniapatients with neutropenia

•• turned off turned off in vitroin vitro, rapidly , rapidly turned back on turned back on in vivoin vivo


Exotoxin AExotoxin A

�� A:B toxin (1:1)A:B toxin (1:1)

�� Most clinical isolates, those Most clinical isolates, those without = less virulentwithout = less virulentwithout = less virulentwithout = less virulent

�� Binds to receptor, internalizedBinds to receptor, internalized

�� Regulation by ironRegulation by iron

�� Similar in structure, function to Similar in structure, function to diphtheria toxindiphtheria toxin


� 90% pigmented• common diagnostic feature

• involved in iron acquisition

� Pyocyanin

Other Virulence FactorsOther Virulence Factors

• antibacterial, aids colonization

• damages endothelial tissue in vitro

• formation of superoxide, peroxide

� Pyochelin mediates conversion of superoxide to hydroxyl

� Fluorescein: flouresces in tissue2727Prof. Muhammad Akram Hossain, Prof. Muhammad Akram Hossain,


�� Broadly resistant to Broadly resistant to antibiotics, plasmidantibiotics, plasmid--mediatedmediated

Antibiotic ResistanceAntibiotic Resistance

�� Resistance mediated by Resistance mediated by loss of appropriate porins loss of appropriate porins for entryfor entry

�� Treatment often fails, Treatment often fails, mortality > 80%mortality > 80%


Reported susceptibilities Reported susceptibilities

�� Ureidopenicillins, Ureidopenicillins,

�� Aminoglycosides, Aminoglycosides,

�� Ceftazidime, Ceftazidime, �� Ceftazidime, Ceftazidime,

�� Fluoroquinolones, Fluoroquinolones,

�� Carbapenems Carbapenems

�� Multiresistance may occur Multiresistance may occur


TreatmentTreatment

�� BecauseBecause PP.. aeruginosaaeruginosa isis commonlycommonly resistantresistanttoto antibiotics,antibiotics, infectionsinfections areare usuallyusually treatedtreatedwithwith twotwo antibioticsantibiotics atat onceonce.. PseudomonasPseudomonasinfectionsinfections maymay bebe treatedtreated withwith combinationscombinations ofofceftazidimeceftazidime (Ceftaz,(Ceftaz, Fortraz,Fortraz, Tazicef),Tazicef),ciprofloxacinciprofloxacin (Cipro),(Cipro), imipenemimipenem (Primaxin),(Primaxin),gentamicingentamicin (Garamycin),(Garamycin), tobramycintobramycin (Nebcin),(Nebcin),gentamicingentamicin (Garamycin),(Garamycin), tobramycintobramycin (Nebcin),(Nebcin),ticarcillinticarcillin--clavulanateclavulanate (Timentin),(Timentin), ororpiperacillinpiperacillin--tazobactamtazobactam (Zosyn)(Zosyn)..

�� MostMost antibioticsantibiotics areare administeredadministered intravenouslyintravenouslyoror orallyorally forfor twotwo toto sixsix weeksweeks.. TreatmentTreatment ofof ananeyeeye infectioninfection requiresrequires locallocal applicationapplication ofofantibioticantibiotic dropsdrops..


PreventionPrevention

�� MostMost hospitalshospitals havehave programsprograms forfor thethe

preventionprevention ofof nosocomialnosocomial infectionsinfections.. PatientsPatients

withwith cysticcystic fibrosisfibrosis maymay bebe givengiven periodicperiodic dosesdoses

ofof antibioticsantibiotics toto preventprevent episodesepisodes ofof

pseudomonaspseudomonas pneumoniapneumonia..

�� MinorMinor skinskin infectionsinfections cancan bebe preventedprevented byby

avoidingavoiding hothot tubstubs withwith cloudycloudy waterwater;;

•• avoidingavoiding publicpublic swimmingswimming poolspools atat thethe endend ofof thethe dayday;;

•• removingremoving wetwet swimsuitsswimsuits asas soonsoon asas possiblepossible;; bathingbathing

afterafter sharingsharing aa hothot tubtub oror usingusing aa publicpublic poolpool;;

•• cleaningcleaning hothot tubtub filtersfilters everyevery sixsix weeksweeks;; andand usingusing

appropriateappropriate amountsamounts ofof chlorinechlorine inin thethe waterwater..


Pseudomonas malleiPseudomonas mallei

�� Glanders in horses, transmitted to man Glanders in horses, transmitted to man

�� Rare in the West, usually found in Asia, Rare in the West, usually found in Asia, Africa, Middle EastAfrica, Middle EastAfrica, Middle EastAfrica, Middle East

�� Necrosis of nasal mucus membranes, Necrosis of nasal mucus membranes, lymphatics, lymph nodes, skinlymphatics, lymph nodes, skin

�� Acute or chronic pneumonia may also occurAcute or chronic pneumonia may also occur


BurkholderiaBurkholderiapseudomalleipseudomallei

�� 15 species in genus, 15 species in genus, B. cepacia B. cepacia andandB. B. pseudomallei pseudomallei only human pathogensonly human pathogens

�� B. pseudomalleiB. pseudomalleicauses melioidosiscauses melioidosis•• endemic to Southeast Asia, Northern Territory of endemic to Southeast Asia, Northern Territory of

Australia; significant number of cases were Australia; significant number of cases were diagnosed in returning Vietnam veteransdiagnosed in returning Vietnam veterans

•• infection by exposure to organism in soil and infection by exposure to organism in soil and surface watersurface water


�� Benign pulmonary diseaseBenign pulmonary disease

�� Rapidly fatal septicemia with disseminated abscessesRapidly fatal septicemia with disseminated abscesses

�� Latency leads to recrudescence (up to 26 years)Latency leads to recrudescence (up to 26 years)

Virulence factorsVirulence factors

BurkholderiaBurkholderiapseudomallei….pseudomallei….

�� Virulence factorsVirulence factors•• metalloprotease, serine proteasemetalloprotease, serine protease

•• lipase, phospholipase C, hemolysinlipase, phospholipase C, hemolysin

•• lethal toxin not yet identifiedlethal toxin not yet identified


pseudomonas by akram.ppt - mymensingh medical college file/pseudomonas by akram.pdf ·...

Documents