Microbiology Tests - Suburban Diagnostics

SubUrban Icon Microbiology Tests

The department of microbiology has always been a key focus area at Suburban Diagnostics and has now become a centre of excellence in the diagnosis of infectious diseases.  


  • State-of-the-art technology with US FDA-approved instruments like BacT/ALERT, Vitek 2 Compact, MGIT Bactec, Gene Xpert
  • Dedicated set-up with separate area for processing of samples of bacteria, TB and fungus
  • TB Lab is RNTCP accredited for first line drug testing
  • Updated CLSI guideline used for the interpretation of sensitivity of reports
Our key offerings in Suburban Diagnostics
  • Blood culture
  • Bacterial culture and sensitivity
  • Fungal culture and sensitivity
  • Urine culture
  • TB culture
  • TB Genexpert
  • TB sensitivity
  • MRSA screening
  • OT sterility using air sampler
  • Autoclave testing
  • Water sterility
Blood culture:

  • Blood cultures are done using an automated system – Bact/alert
  • Paired blood cultures using 1 aerobic and 1 anaerobic bottle helps increase the yield of positive blood cultures 2.5 times
  • Polymeric beads in the bottle adsorb antibiotics, if any, in the sample and allow organisms to grow uninhibited
Bacterial Culture

  • The bacterial isolate is identified and susceptibility done using and automated system – Vitek 2 Compact
  • The identification is done using 64 biochemicals
  • Susceptibility to various antibiotics is deduced using MIC and breakpoint MIC values
  • Susceptibility based on MIC values using an automated system ensures quality, precision, accuracy of results
  • Treatment of patients based on culture reports using MIC values ensures better clinical outcome as MIC values help select an appropriate antibiotic
Fungal culture:

  • Fungal infections are found in immune-compromised patients such as those on long term steroids, diabetics, patients with cancer or on anti-cancer therapy, transplant recipients, pre-term infants and the elderly
  • The samples processed for fungal culture are blood, urine, pus, tissue, body fluids, sputum, BAL, skin, hair and nail
  • Yeast cells isolated in the above samples can be accurately identified and susceptibility to 6 antifungals is given
Urine Culture:

  • Urinary isolate is identified and susceptibility is done using Vitek 2 Compact
  • The susceptibility to various groups of antibiotics is deduced using MIC and breakpoint MIC values
  • We use special containers with boric acid, a urinary preservative, to maintain the colony count of bacteria and avoid overgrowth

At Suburban Diagnostics, we retrospectively studied around 25000 samples of urine culture, over a period of 3 years. The study concluded the following:


  • Tb culture useing MGIT BACTEC is the gold standard in the diagnosis of tuberculosis
  • MGIT BACTEC employs liquid media which enhances the growth of mycobacterium
  • Provides culture results in 10 to 14 days, while the conventional LJ method yields results in 28 – 42 days
Genexpert TB test – MTB / RIF test – CBNAAT

  • Rapid and confirmatory molecular detection of mycobacterium tuberculosis genome and rifampicin resistance (rpoB gene mutation)
  • Can be performed on both pulmonary and extra pulmonary samples
  • Highly sensitive (88%) and specific (98%)
  • WHO recommendations: Genexpert TB test should be used as the initial diagnostic test in individuals suspected of MDR TB or HIV TB co-infection
  • Sensitivity is done towards 13 drugs – Streptomycin, INH, Rifampicin, Ethambutol, Pyrazinamide, Kanamycin, Ethionamide, PAS, Moxifloxacin, Ciprofloxacin, Levofloxacin, Amikacin, Capreomycin
  • Results are available in 2-3 weeks
  • Test done using MGIT BACTEC

  • MRSA is Methicillin Resistant Staphylococcus resistant to many drugs including Penicillin, Cephalosporins and Carbapenems
  • It is done in preoperative cases during transplants, implants and cardiac surgeries
  • Hand impressions and nasal swabs are tested
  • Results are available in 48 to 72 hours

  • Uses automated air samplers which actively sample the air in the operation theater using a vacuum. The number of colonies on the agar plate after 48 hours of incubation are an indicator of the sterility of air in the operation theater
  • Results are available in 48-72 hours
  • It can measure both the bacteria and fungi
Testing of Autoclaves
  • Testing of autoclaves needs to be done using biological indicators every week
  • This is to check if the autoclave is working at the right temperature and pressure to achieve sterilization of the various items used in the hospital or nursing homes
  • The biological indicators will be provided to the respective hospitals
  • Reports are available in 3 days
  • It tests for bacteria present in water in order to check its potability
  • Water in operation theater, ICU, hospitals and dialysis water can be also tested for the presence of bacteria
  • Membrane filtration technique is used

For any further information, please email Dr. Shweta Naik at

To book a test, please click here