SputumSputum

1.Sputum should be collected prior to antimicrobial therapy.

2. Sputum preferably is collected in the morning, patient should be standing or sitting .

3 .Patient takes a deep breath and coughs as hard and as deeply as

possible in container.

A 24-hour collection or repeated (three) specimens are useful for diagnosis of TB .

4. Sputum must be inspected as follows:4. Sputum must be inspected as follows:

• a watery, white-frothy, or mucoid sputum represents pharyngeal secretions & should be examined only for TB.

• a purulent, mucopurulent , yellow, green or brown blood - stained sputum is acceptable for all infections .

5. After collection , cap of container is 5. After collection , cap of container is tightened, & sent immediately to tightened, & sent immediately to laboratory.laboratory.

• In case of delay, specimen is kept in a refrigerator.

• Microscopic examination of sputum for leukocytes & epithelial cells

should be done immediately.

Sputum can be used for detection of bacteria, & fungi

With exception of tuberculosis, microbiological investigation of sputum will not give correct

diagnosis.

•Sputum is contaminated with secretions of oropharynx which contain commensals & potential pathogens (pneumococci,H.influenzae) •A good technique for expectoration and collection of sputum is necessary .

•In children, tracheal secretion can be aspirated through a nasopharyngeal catheter.

•Gastric washing are collected only for TB

•Other organisms are rapidly killed by high acidity of stomach content.

@ For severely ill patients, techniques @ For severely ill patients, techniques available are :available are :

•transtracheal aspiration

•bronchoscopic aspiration

•bronchoalveolar lavage

•direct needle aspiration from lung .

UrineUrine

@Originally urine is sterile.

@ Urethra & genitalia are colonized by bacteria that can cause UTI .

@ Even carefully collected urine sample will be contaminated.

@ UTI is predicted by bacteria count .

@ Count of 100000-1000000/mL indicates UTI

@ Incidence of UTI increases when bacteruria is associated with pyuria.

@ First morning urine collected because it is concentrated.

@ Urine must be free of any discharge or pus from genitalia

@ Urine is transported within one hour to avoid growth of bacteria.

@ If transport is not quick, urine is refrigerated and processed within 24 hours. within 24 hours. Boric acid is not added.Boric acid is not added.

Sexually transmitted diseasesSexually transmitted diseases • STD are caused by viruses, bacteria & fungi

@ Specimens are collected before giving antibiotics .

GonorrhoeaGonorrhoea

@ In males diagnosis is by microscopic testing of urethral smear. @ In asymptomatic patients, culture is needed

@ In females, gonorrhoea affects cervix, urethra, Bartholin’s gland, & Skene’s gland. @ In females there is no or slight symptoms, so culture is important.

Gonococcal urethritis in malesGonococcal urethritis in males

@ @ Purulent discharge is swabbed & a thin smear on a slide is made and a culture plate is inoculated.

@ If delayed, swab is transported by Stuart or Ames media.

•Gonococci will remain viable up to 24 hrs in these transport media.

•Urine is NOT examined for diagnosis of gonococcal urethritis. •Prostatic massage does not increase

recovery of gonococci.

Vaginal dischargeVaginal discharge

•Vaginal discharge is due to :

@ Vaginitis caused by C. albicans.

@ bacterial vaginosis caused by Gardnerella vaginalis and anaerobic bacteria.

•Vaginal discharge swab is collected from posterior vaginal fornix using a speculum . •Discharge is examined as wet preparation for Candida & Gardnerella. No Culture is recommended

Genital ulcersGenital ulcers

•Genital ulcers may be due to T. pallidum & H. ducreyi.

•Dark field microscopy is done for

detection of T. pallidum.•Serous fluid is expressed from ulcer base,& examined microscopically. Material for cultivation of H. ducreyi is sampled from ulcer base and used to inoculate a selective culture plate.

Blood for serologyBlood for serology

• 5 mL blood is collected for serology of syphilis or HIV. •If result is negative in a suspected patient, a second blood specimen should be tested after 3-4 weeks.

StoolsStools

•Feces for diagnosis of infectious Feces for diagnosis of infectious diarrhea is collected in early stage & diarrhea is collected in early stage & prior to antibiotic treatment.prior to antibiotic treatment.

@ Stool is collected in a container, a clean bed-pan, or a paper towel. Stool is then transferred to a suitable container with a lid.

@ Size should not be less than: @ 5 g for bacteriological examinations.

•Parts containing blood or mucus should be selected for analysis.

@ Stool must not be mixed with urine & must not be left exposed to air in containers.

•Penicillin bottles, match boxes, and

banana leaves are forbidden.Rectal swabs is taken if patient is Rectal swabs is taken if patient is unable to give stool.unable to give stool.

•If delayed, it must be placed in a If delayed, it must be placed in a transport medium ( Cary-Blair ). transport medium ( Cary-Blair ).

4.Technician should note:4.Technician should note: • Consistency ( watery, mushy, Consistency ( watery, mushy, formed).formed). • Presence of blood, pus, mucusPresence of blood, pus, mucus

5. Stool for bacteriology is processed 5. Stool for bacteriology is processed within few hours.within few hours. •If delayed, it is refrigerated or a If delayed, it is refrigerated or a transport medium is used, where transport medium is used, where pathogens may survive for one week pathogens may survive for one week even at room temp.even at room temp.

•Alkaline peptone water is a transport & Alkaline peptone water is a transport & enrichment medium for Vibrio choleraeenrichment medium for Vibrio cholerae

7. If stools are shipped through mail:7. If stools are shipped through mail: • Leak-proof stool containers must be Leak-proof stool containers must be enclosed in a strong outer container enclosed in a strong outer container with an absorbent material to absorb with an absorbent material to absorb liquid in case of breakage of container. liquid in case of breakage of container.