Lecture 36 - Pseudomonas & Non- Fermenters - 18 Oct 2006

Pseudomonas & nonfermenters

Dr. Noura AL-Sweih

EMQ          

Salmonella paratyphi A Streptococcus pneumoniae Vibrio cholera Vancomycin Linezolide Neisseria gonorrhoae Staphylococcus aureus E.coli Streptococcus agalactiae

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A 25 yrs old lady with dysuria New borne boy with septicemia 2hrs after drinking milk developed sever vomiting 3 yrs old child with fever, irritability and ear ache 67yrs old man with hip joint prosthesis and septicemia 24 yrs old man return from SEA with urethral discharge 34 yrs old Bangladeshi man complained of sever watery diarrhea 45 yrs old Pakistani man complained of fever for 3 weeks A case of endocarditis caused by vancomycin resistant enterococci( VRE)

Pseudomonas & non- fermenters  Gram-

 Strict

 They

Negative bacilli, non-fermentative

aerobe

are saprophytes, widely distributed in soil, water, and other moist environments

Pseudomonas & non- fermenters Reclassification of pathogenic pseudomonads

Genus Pseudomonas

Species P. aeroginosa

Stenotrophomonas

S. maltophilia

Burkholedria

B. cepacia

Pseudomonas aeruginosa

GNB

Oxidase +

Green- diffusible pigment

Biochemical tests

 Name

the organisms that are oxidase positive?  Neisseria spp  Vibrio spp  Pseudomonas spp

Pseudomonas aeruginosa Habitat man and animal gastrointestinal tract, water, soil, most of hospitals environment, survive in antiseptics, saline, and sterile water in hospitals

Pseudomonas aeruginosa Laboratory characteristics  Produce diffusible green pigments  Oxidase-Positive  Oxidative and not fermentative

Pseudomonas aeruginosa Pathogenesis  Can infect any external site or organ  Community acquired infections are superficial [otitis externa]  Hospital acquired infections are; common, severe & variable

Pseudomonas aeruginosa Patients at risk to develop hospital acquired infections

• Elderly • Burn • Malignancy • Immunosuppressive [corticosteroids] • Urinary catheters • Mechanical ventilation (ventilator associated pneumonia)

Pseudomonas aeruginosa Clinical Infections

• UTI (especially nosocomial UTI) • Wound infections • Chronic Otitis Media and Externa • Septicaemia & Necrotizing pneumonia •

( high mortality ) Lower respiratory tract infection in Cystic fibrosis

Pseudomonas aeruginosa Clinical Infections

• Eye infections, secondary to trauma or •

surgery,can be severe and result from contact lenses, contaminated eye drops Endocarditis, right side, tricuspid in drug addict

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Name other organisms known to cause infective endocarditis? Viridans streptococci (native endocarditis) Staphylococcus epidermidid (prosthetic endocarditis) Enterococcus faecalis (endocarditis in elderly) Pseudomonas areuginosa (drug addict endocarditis)

Pseudomonas aeruginosa Treatment:

• P.aeruginosa is normally resistant to most •

commonly used antibiotics Major antipsudomonal antibiotics are:

• Aminoglycosides [ gentamicin & amikacin] • Piperacillin + tazobactam

• Ceftazidime • Ciprofloxacin • Imipenem & meropenem

Sten otro pho mona s Malto philia  

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Opportunistic pathogen Cause infection mainly in immunocompromised patients High mortality rate reaching 60% in patients with haematological malignancies It is resistant to most commonly used antibiotics except Ciprofloxacin & trimethoprimsulfamethoxazole [ co-trimoxazole]

Burkholderia Cepacia  It

is non-pathogenic in healthy individuals  It is a major opportunistic cause of respiratory infection in patients with cystic fibrosis, bacteraemia occur in 20% of colonized patients  It is intrinsically multi-resistant  Antibiotics may be used in treatment include Co-trimoxazole, & imipenem

Cystic Fibrosis