Q : What do we come to know from routine examination and from culture of urine?

A : Routine urine examination tells us about the presence or absence of certain substances the glucose, proteins, ketones, nitrites, bilirubin which could be an indication of certain diseases like diabetes mellitus, jaundice, infection etc. Blood in urine could indicate infection, stones etc. Pus cells could indicate infection. Casts could indicate real disease. Crystals like oxalate, urate etc. are seen following high dietary intake of food rich in these minerals. Culture of urine helps us to isolate bacteria causing infection.

Q : Why do we take 2 days for culture and sensitivity - Why not one day, now that there are new technologies available?

A : Routine examination is done by directly visualizing urine under the microscope and doing certain chemical tests on the urine sample which takes a few minutes. In culture, the urine is plated on culture media which provide nutrition for the bacteria to grow. After overnight incubation bacteria grow on the media and then are replated on media on which different antibiotic discs are put and again after overnight incubation we see which antibiotics are able to prevent the growth of the bacteria.

Q : Is the morning sample of urine necessary for a test?

A : Morning sample of urine is the ideal sample for culture, but a sample can be collected at any time of the day after proper cleaning and washing the area with soap and water to prevent bacteria from the surrounding areas from entering the urine or this will give you erroneous result.

Q : What should the time gap be between collection and giving the urine sample to the laboratory?

A : Urine sample should be brought to the lab as soon as possible (within 1-2 hours of collection) as the urine provides an excellent source of nutrition to the bacteria present and the bacteria multiply and will give a wrong result when tested after a longer time interval In case there is a delay the sample can be placed inside the refrigerator (not freezer)

Q : What should the time gap be between collection and examination of a stool specimen?

A : Stool specimens should be delivered to the laboratory within one hour as the organisms die out quickly and will not be detected.

Q : What is the difference between sputum and saliva?

A : Saliva is the watery secretion in the mouth which contains different types of bacteria present normally in the mouth. Sputum is the thick yellow secretion from the lungs which usually contains the bacteria causing infection in the lungs. To bring up a sputum sample one should placed both hands on the waist, take 2-3 deep breaths and cough up vigorously so the sputum comes out from the lungs. Try a hot drink before coughing up sputum.

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