CULTURE OF NORMALLY STERILE FLUIDS

Lusubilo Malakbungu(BMLS)Lusu2012

Normally sterile Fluids

These are fluids that do not contain commensals. Any marked presence of commensals can lead to progression of disease in these fluid and site in particular.

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Some diseases occuring in normal sterile sites Amnionitis-inflamation of the amnion(fetal

sac).Due to contamination of vaginal flora or instrumentation during antenatal medical procedures.

Pericaditis-inflamation of the pericardium(membrane enveloping the heart).

Peritonitis-inflamation of the peritoneum. Empyema-collection of pus in pleural

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• Septic athritis- pyogenic infection of a joint. Spread by haematogeneous spread.

• Bursitis-inflamation of bursa(small fluid filled sac of fibrous tissues lined with synovial membrane)

• Meningitis-inflamation of the meninges in the brain. Agents can be Haemophilus influenza, Streptococcus pneumoniae.Neisseria meningitidis.

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CULTURING PROCEDURES FOR

SOME NORMAL STERILE FLUIDS

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1.Cerebral Spinal Fluid Collection should be done by

experienced personnel. 5-10ml of CSF should be collected in

two sterile tubes. Disinfection of the skin is mandatory. Cells of CSF disintergrate rapidly,so

they should be processed immediately without delay.

Lumbar puncture done between L3 and L4 Lusu2012

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. If transport to laboratory is not

possible,inoculate CSF aseptically into Trans-Isolate (T-I)Medium and held overnight at 35C

MACROSCOPIC

Cloudy appearance give a clue of pyogenic infections.

Gram staining

CSF should be centrifuged and the sediments smeared for staining.

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CULTURE The drop of sediments after

centrifugation is used for culture. MEDIA:Blood agar,Chocolate

Agar(Tryptone Soy Agar) .Suspected organisms for this culture include N.meningitidis,H.influenza,S.pneumoniae.

-SDA-used for any clue of yeast cells in gram stain. Lusu2012

. MCA-when neonatal meningitis is

suspected,for isolating Escherichia coli also Listeria monocytogenes

RESULTS

Colonies could be of:Neisseria meningitidis(in Blood Agar & chocolate agar)

S.pneumoniae,H.influenza(CA),Cryptococcus neoformans(SDA).

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Confirmation of coloniesH.Influenzae will grow on CA and satellite

colonies in the vicinity of staphylococcus streak.

H.Influenza type b-antiserum slide agglutination.

On CA rapid oxidase positive is suggested to be meningococci.

N.Meningitidis antisera(A,B,C) in slide agglutination

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OTHER STERILE SITES Pericardial effusion

This infections pericaditis can be:- Purulent caused by bacteria. Benign can be due to viruses Granulomatous which are caused by

mycobacterium tuberculosis.

Wide range of bacteria isolated for purulent include Streptococcus spp,Neisseria spp,Haemophilus.

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BONE MARROW

Should be inoculated into commercially available Nutrient broth(e.g Brain-Heart infusion broth or TSB)

Common isolate is S.aureus.

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OTHER EFFUSIONS

Synovial Pleural Ascitic (peritoneal)

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Collection

Is done by a well trained medical officer.

After aspiration ,aseptically dispense the fluid as follows;

2-3ml into a dry,sterile,screw-cap tube or bottle to observe for clotting.

9 ml into a screw-cap tube or bottle which contains 1ml of sterile tri-sodium citrate, mix well for anticoagulation.

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Microscopic Examination

Gram smear-look for pus cells and bacteria.

Ziehl-Neelsen

Look for AFB

Wet preparation for crystals:

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CULTURE Blood agar (incubate aerobically) Chocolate agar(incubate in C02 MacConkey agar

Incubate aerobically.

For suspected Tuberculosis-required facilities of tuberculosis should be used.

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Report culturesLook particularly for

S.aureus,s.pyogenes,s.pneumoniae,H.influenzae,Neisseria spp,Enterobacteria.

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references

Isolation of Agents from Normally Sterile Sites;CDC covers 2003.

Investigations of Fluid from Normally sterile sites; Issued by Standards Unit, Department for Evaluations, Standards and Training,Centre for Infections.

Cheesebrough M.District Laboratory Practice in Tropical Countries, Part 2 Second Edition Lusu2012