A CASE REPORTA CASE REPORT

A 3 yr old female child who had undergone A 3 yr old female child who had undergone chemotherapy for ALL a few weeks backchemotherapy for ALL a few weeks back

Now Presented with c/oNow Presented with c/o Ear discharge- 5 days durationEar discharge- 5 days duration Vulvar necrotic lesion 2 days durationVulvar necrotic lesion 2 days duration

O/EO/E Toxic appearanceToxic appearance Fever, tachycardia, tachypnoea Fever, tachycardia, tachypnoea HypotensionHypotension A single vulvar necrotic lesionA single vulvar necrotic lesion Other similar lesions on thoracic region & lower Other similar lesions on thoracic region & lower

extremitiesextremities

InvestigationsInvestigations Total WBC – 1600/mmTotal WBC – 1600/mm33 (N-0%, L-64%, M-32%) (N-0%, L-64%, M-32%) Hb- 8.5 g/dlHb- 8.5 g/dl CRP- 190 mg/dlCRP- 190 mg/dl Electrolyte imbalance (hypokalemia, Electrolyte imbalance (hypokalemia,

hyponatremia)hyponatremia) Blood culture& wound swab sent for c/sBlood culture& wound swab sent for c/s

Initial treatment givenInitial treatment given Ionotropic support with norepinephrineIonotropic support with norepinephrine Mechanical ventilationMechanical ventilation Empirical antibiotic therapy withEmpirical antibiotic therapy with Pipzo, Amikacin & ClindamycinPipzo, Amikacin & Clindamycin

Surgical debridement of necrotic lesion was Surgical debridement of necrotic lesion was donedone

Blood culture & wound swab report was sent to Blood culture & wound swab report was sent to microbiology lab for culture & sensitivitymicrobiology lab for culture & sensitivity

Blood culture & wound swab reportBlood culture & wound swab report Pseudomonas aeruginosa grown in culture Pseudomonas aeruginosa grown in culture

sensitive to pipzo, Imipenem, Tobramycinsensitive to pipzo, Imipenem, Tobramycin

PSEUDOMONAS PSEUDOMONAS INFECTIONSINFECTIONS

Pseudomonas spp.Pseudomonas spp. Structure and PhysiologyStructure and Physiology Gram-negative rods. Gram-negative rods. Motile with polar flagella.Motile with polar flagella. Obligate aerobe.Obligate aerobe. Oxidase-positive.Oxidase-positive. Do not ferment carbohydrates.Do not ferment carbohydrates. Minimal nutritional reqtsMinimal nutritional reqts Survive where most organismsSurvive where most organisms

cannot;cannot;

Resistant to multiple drugsResistant to multiple drugs..

P. aeruginosa

Forms round colonies with a fluorescent greenish color, sweet odor, and beta hemolysis.

Pyocyanin- nonfluorescent bluish pigment;

pyoverdin- fluorescent greenish pigment;

pyorubin (red)

pyomelanin (black)

Some strains have an exo polysaccharide capsule.(alginate)

Epidemiology Epidemiology

Wide spread in natureWide spread in nature commonly present in commonly present in moist environmentsmoist environments in in

hospitalshospitals

(respiratory equipments, cleaning solutions, (respiratory equipments, cleaning solutions, sinks,bath tubs, toilets, endoscopes, flowers sinks,bath tubs, toilets, endoscopes, flowers etc.)etc.)

Pathogenic when Pathogenic when host defences are host defences are compromised compromised

P. aeruginosaP. aeruginosa can infect almost any external can infect almost any external site or organ, mostly site or organ, mostly acquired in the hospital acquired in the hospital esp in ICUsesp in ICUs

One of the most common causes of hospital One of the most common causes of hospital acquired pneumonia & wound infections.acquired pneumonia & wound infections.

PathogenesisPathogenesis

Rarely cause disease in healthy host, Rarely cause disease in healthy host,

But is highly virulent when host defences are But is highly virulent when host defences are compromisedcompromised

Factors predisposing to Pseudomonas aeruginosa Factors predisposing to Pseudomonas aeruginosa infectionsinfections

DISRUPTION OFCUTANEOUS/MUCOSAL BARRIERS:

Burn injury Cystic fibrosis Dermatitis Penetrating trauma Surgery ET intubation Catheterization Injection drug use

IMMUNOSUPPRESSION

NeutropeniaWBC defectsAntibody defectsDefective CMIExtremes of ageDiabetes mellitusSteroid therapyCancerAIDS

DISRUPTION OF NORMAL BACTERIAL FLORA

Broad spectrum antibiotic therapyExposure to hospitalenvironment

Virulence factors associated with Pseudomonas Virulence factors associated with Pseudomonas infectioninfection

STRUCTURAL COMPONENTSSTRUCTURAL COMPONENTS

CapsuleCapsule

Mucoid polysaccharideMucoid polysaccharide

inhibits antibiotic (aminoglycoside) killing; inhibits antibiotic (aminoglycoside) killing;

Inhibits phagocytosis Inhibits phagocytosis

Pili Pili

AdhesinAdhesin

LipopolysaccharideLipopolysaccharide

Endotoxin activityEndotoxin activity

PyocyaninPyocyanin

Impairs ciliary function; Impairs ciliary function;

mediates tissue damage through production of toxic mediates tissue damage through production of toxic oxygen radicalsoxygen radicals

Virulence factors cont.. Virulence factors cont..

TOXINS AND ENZYMESTOXINS AND ENZYMES

Exotoxin AExotoxin A

Inhibits protein synthesis; produces tissue Inhibits protein synthesis; produces tissue damage (e.g., skin, cornea);damage (e.g., skin, cornea);

ImmunosuppressiveImmunosuppressive

Exotoxin SExotoxin S

Inhibits protein synthesis;Inhibits protein synthesis;

Cytotoxin (leukocidin)Cytotoxin (leukocidin)

Cytotoxic for eukaryotic membranesCytotoxic for eukaryotic membranes

Virulence factors contd…Virulence factors contd…

ElastaseElastase

Destruction of elastin-containing tissues (e.g., Destruction of elastin-containing tissues (e.g., blood vessels, lung tissue, skin), collagen, blood vessels, lung tissue, skin), collagen, immunoglobulins, and complement factorsimmunoglobulins, and complement factors

Alkaline protease, Phospholipase CAlkaline protease, Phospholipase C

causes tissue damage;causes tissue damage;

ANTIBIOTIC RESISTANCE is also a virulence factorANTIBIOTIC RESISTANCE is also a virulence factor

Mechanisms of Antibiotic Resistance in Pseudomonas aeruginosa

INFECTIONS CAUSED BY PSEUDOMONASINFECTIONS CAUSED BY PSEUDOMONAS

1) Pulmonary infections1) Pulmonary infections

2) Skin infections2) Skin infections

3) Urinary Tract Infections3) Urinary Tract Infections

4) Ear infections4) Ear infections

5) Eye infections5) Eye infections

6) Bacteremia & Endocarditis6) Bacteremia & Endocarditis

1. Pulmonary Infections 1. Pulmonary Infections Asymptomatic colonization Asymptomatic colonization Tracheobronchitis Tracheobronchitis Severe necrotizing bronchopneumonia. Severe necrotizing bronchopneumonia.

Colonization is seen in patients withColonization is seen in patients with

cystic fibrosis, cystic fibrosis,

other chronic lung diseases,other chronic lung diseases,

NeutropeniaNeutropenia

Pt on ventilatorPt on ventilator

(Ventilator associated pneumonia)(Ventilator associated pneumonia)

Patients with cystic fibrosis Patients with cystic fibrosis

Mucoid strainsMucoid strains are commonly isolated from are commonly isolated from such patients and are difficult to eradicate with such patients and are difficult to eradicate with antibiotic therapy. antibiotic therapy.

The mortality rate is as high as 70%. The mortality rate is as high as 70%.

2. Primary skin infections2. Primary skin infections

A) Burn wound infectionA) Burn wound infection

common in patients with severe burns.common in patients with severe burns.

Colonization of a burn woundColonization of a burn wound

localized vascular damagelocalized vascular damage

tissue necrosistissue necrosis

bacteremiabacteremia

Predisposing factors for burn infectionsPredisposing factors for burn infections

1. The moist surface of the burn wound1. The moist surface of the burn wound

2. Lack of a neutrophilic response to tissue 2. Lack of a neutrophilic response to tissue

invasioninvasion

B) FolliculitisB) Folliculitis

results from immersion in contaminated water results from immersion in contaminated water (e.g., hot tubs, whirlpools, swimming pools).(e.g., hot tubs, whirlpools, swimming pools).

C) Fingernail infectionsC) Fingernail infections

in people whose hands are frequently exposed to in people whose hands are frequently exposed to water. water.

Secondary infections with Secondary infections with PseudomonasPseudomonas

occur in people who have acne or who depilate occur in people who have acne or who depilate their legstheir legs

3. Urinary tract Infection 3. Urinary tract Infection

in patients with in patients with long-term indwelling urinary long-term indwelling urinary catheterscatheters

Exposure to broad spectrum antibiotics selects Exposure to broad spectrum antibiotics selects for multi drug resistant bacteria.for multi drug resistant bacteria.

4. Ear Infections4. Ear Infections

A) Otitis externaA) Otitis externa

swimming an important risk factor swimming an important risk factor ("swimmer's ("swimmer's ear").ear").

managed with topical antibioticsmanaged with topical antibiotics

B) Malignant otitis externaB) Malignant otitis externa

Virulent form of disease seen in diabetic and Virulent form of disease seen in diabetic and elderly patients. elderly patients.

Invades the underlying tissues,damage the Invades the underlying tissues,damage the cranial nerves and bones, can be life cranial nerves and bones, can be life threatening. threatening.

Aggressive, antimicrobial and surgical Aggressive, antimicrobial and surgical intervention is required for patientsintervention is required for patients

C) Chronic otitis media.C) Chronic otitis media.

EyeEye Infections Infections

Infections of the eye occur after Infections of the eye occur after initial trauma to initial trauma to the corneathe cornea (e.g., abrasion from contact lens, (e.g., abrasion from contact lens, scratch on the eye surface) scratch on the eye surface)

and then and then exposure to exposure to P. aeruginosaP. aeruginosa in in contaminated water.contaminated water.

Corneal ulcersCorneal ulcers develop and can progress to eye- develop and can progress to eye-threatening disease unless prompt treatment is threatening disease unless prompt treatment is institutedinstituted

Bacteremia and EndocarditisBacteremia and Endocarditis..

Mortality rate in affected patients is higher with Mortality rate in affected patients is higher with P. aeruginosaP. aeruginosa bacteremia because of bacteremia because of

1. The predilection of the organism for 1. The predilection of the organism for immunocompromisedimmunocompromised patients patients

2. The 2. The inherent virulenceinherent virulence of of Pseudomonas.Pseudomonas.

Bacteremia occurs most often in patients Bacteremia occurs most often in patients withwith

Neutropenia, Neutropenia,

Diabetes mellitus, Diabetes mellitus,

Extensive burns, Extensive burns,

Hematologic malignancies. Hematologic malignancies.

Most bacteremias originate from infections of the Most bacteremias originate from infections of the

Lower respiratory tract, Lower respiratory tract,

Urinary tract, and Urinary tract, and

Skin and soft tissue (particularly burn wound Skin and soft tissue (particularly burn wound infections). infections).

Ecthyma gangrenosumEcthyma gangrenosum

Characteristic skin lesions in pseudomonas Characteristic skin lesions in pseudomonas bacteremia. bacteremia.

Erythematous vesicles that become Erythematous vesicles that become hemorrhagic, necrotic, and ulcerated. hemorrhagic, necrotic, and ulcerated.

PseudomonasPseudomonas endocarditis endocarditis

Most commonly observed in Most commonly observed in intravenous-drug intravenous-drug abusers. abusers.

Acquire the infection from the use of drug Acquire the infection from the use of drug paraphernalia contaminated with the paraphernalia contaminated with the waterborne organisms. waterborne organisms.

The tricuspid valveThe tricuspid valve is often involved, is often involved,

The infection is associated with a chronic course The infection is associated with a chronic course

Other InfectionsOther Infections Gastrointestinal tract infections Gastrointestinal tract infections Central nervous system infections Central nervous system infections Musculoskeletal systemMusculoskeletal system

The underlying conditions required for The underlying conditions required for most infections aremost infections are

(1) The presence of the organism in a moist(1) The presence of the organism in a moist

reservoir reservoir (2) The circumvention or elimination of host(2) The circumvention or elimination of host

defensesdefenses

Gastrointestinal infectionsGastrointestinal infections. . Any part of the git from the oropharynx to the rectum Any part of the git from the oropharynx to the rectum

can be affectedcan be affected Primarily in Primarily in immunocompromisedimmunocompromised individuals. individuals.

Presents asPresents as Pediatric diarrhea, Pediatric diarrhea, Typical gastroenteritis, Typical gastroenteritis, Necrotizing enterocolitisNecrotizing enterocolitis. . Important portal of entry in Important portal of entry in

PseudomonasPseudomonas septicemia septicemia

& bacteremia& bacteremia

Central nervous system infectionsCentral nervous system infections. .

Meningitis and brain abscesses. Meningitis and brain abscesses.

Invades the CNS from a contiguous structure Invades the CNS from a contiguous structure such as the inner ear or paranasal sinus, such as the inner ear or paranasal sinus,

oror

Inoculated directly by means of head trauma, Inoculated directly by means of head trauma, surgery or invasive diagnostic procedures, surgery or invasive diagnostic procedures,

oror

Spreads from a distant site of infection such as Spreads from a distant site of infection such as the urinary tract.the urinary tract.

Laboratory DiagnosisLaboratory Diagnosis Specimen:Specimen: skin lesions, pus, urine, blood, skin lesions, pus, urine, blood,

spinal fluid, sputum.spinal fluid, sputum. Culture:Culture: Blood agar plate and Differential Blood agar plate and Differential

media (MacConkey agar)media (MacConkey agar)

Identification of Identification of P. P.

aeruginosaaeruginosa is is

usually based on usually based on

Colonial morphology, Colonial morphology,

ββ-hemolysis, -hemolysis,

Oxidase positivity, Oxidase positivity,

Characteristic pigments Characteristic pigments

Sweet odor, Sweet odor,

Growth at 42 C. Growth at 42 C.

TreatmentTreatment

The antimicrobial therapy for The antimicrobial therapy for PseudomonasPseudomonas infections is frustrating because infections is frustrating because

(1) the bacteria are (1) the bacteria are typically resistanttypically resistant to to most antibioticsmost antibiotics

(2) the infected patient with compromised (2) the infected patient with compromised host host defenses cannot augment the antibiotic defenses cannot augment the antibiotic activityactivity

Combined antibiotic therapyCombined antibiotic therapy is generally is generally required to avoid resistance. required to avoid resistance.

..Avoid using inappropriate broad-spectrum antibiotics, Avoid using inappropriate broad-spectrum antibiotics,

which can suppress the normal flora which can suppress the normal flora and permit overgrowth of resistant pseudomonadsand permit overgrowth of resistant pseudomonads

Some Antipseudomonadal antibiotics:Some Antipseudomonadal antibiotics:

PiperacillinPiperacillin, Piperacillin/tazobactam (Penicillins), Piperacillin/tazobactam (Penicillins)

Ceftazidime Ceftazidime (Cephalosporins)(Cephalosporins)

Imipenem,Imipenem, meropenem (carbapenems) meropenem (carbapenems)

TobramycinTobramycin, Amikacin, Gentamicin , Amikacin, Gentamicin (Aminoglycosides)(Aminoglycosides)

CiprofloxacinCiprofloxacin (Quinolones) (Quinolones)

Polymyxin B,Polymyxin B, ColistinColistin

PREVENTION & CONTROLPREVENTION & CONTROL Its impossible to eliminate PseudomonasIts impossible to eliminate Pseudomonas from from

the hospital environment.the hospital environment.

Effective infection-control practices should Effective infection-control practices should concentrate on preventing the concentrate on preventing the

Contamination of sterile equipment, such as Contamination of sterile equipment, such as respiratory therapy and dialysis machines, respiratory therapy and dialysis machines,

Cross-contamination of patients by medical Cross-contamination of patients by medical personnel. personnel.

The inappropriate use of broad-spectrum The inappropriate use of broad-spectrum antibiotics should also be avoidedantibiotics should also be avoided

Pseudomonas and related organisms

Other Aerobic nonfermenters

Burkholderia cepacia: RT infection in cystic fibrosis patients, UTI, opportunistic infections

Burkholderia pseudomallei: opportunistic pulmonary infections

Stenotrophomonas maltophilia: opportunistic infections

Acinetobacter baumannii: opportunistic infections of respiratory tract infections

Moraxella catarrhalis: opportunistic RT infections

CASE REVIEWCASE REVIEW

DiagnosisDiagnosis

Pseudomonas aeruginosa Sepsis in a child with Pseudomonas aeruginosa Sepsis in a child with neutropenia associated with Ecthyema neutropenia associated with Ecthyema gangrenosumgangrenosum

Pipzo was continued as per AST reportPipzo was continued as per AST report

OUTCOMEOUTCOME

Successful completion of 2 wks course of Successful completion of 2 wks course of antimicrobial therapyantimicrobial therapy

Complete recovery and healing of necrotic Complete recovery and healing of necrotic lesionslesions