Complete Blood Count (CBC) Test

The complete blood count (CBC) is a common blood test that measures the different cells in your blood, including red blood cells, white blood cells, and platelets. It gives your doctor a broad picture of your overall health and helps detect many different conditions.

The Bacterial gyrA Gene Drug Resistance test is a molecular diagnostic test that looks for specific genetic mutations in the gyrA gene of bacteria. The gyrA gene provides instructions for making DNA gyrase, an enzyme that is a common target for a group of antibiotics called fluoroquinolones (such as ciprofloxacin, levofloxacin, and moxifloxacin). When bacteria develop mutations in this gene, the antibiotics can no longer effectively kill them, leading to drug-resistant infections.

This test is often performed as part of a routine checkup, or to help investigate symptoms such as fatigue, weakness, fever, unexplained bruising, or weight loss. It can also be used to monitor an existing condition like anemia or infection, or to see how a treatment is affecting your body.

This test is performed when your healthcare provider suspects a bacterial infection that might be resistant to standard antibiotic treatments. It is commonly used for infections such as tuberculosis, gonorrhea, urinary tract infections, and respiratory infections. By identifying drug-resistant mutations early, doctors can select more effective antibiotics and avoid treatments that won't work, leading to better outcomes and preventing the spread of resistant bacteria.

The test is done with a simple blood draw, usually from a vein in your arm. A healthcare provider will clean the site, place a band around your upper arm, and collect a small sample of blood into a tube. The sample is sent to a laboratory, and the entire process typically takes only a few minutes.

A sample is collected from the site of your infection—this could be blood, urine, sputum, or tissue from the infected area. The sample is then sent to a laboratory where molecular techniques (such as PCR or gene sequencing) are used to detect mutations in the gyrA gene. The test does not measure the sample directly in your blood serum but analyzes the genetic material of the bacteria present in the specimen.

Your results show whether your blood cell counts are within normal ranges. Abnormal values may suggest conditions such as anemia, infection, inflammation, bleeding or clotting problems, or certain blood disorders. However, an abnormal result does not always mean serious illness, so your doctor will interpret the numbers along with your symptoms, history, and other tests.

If the test detects gyrA gene mutations, it means the bacteria causing your infection are likely resistant to fluoroquinolone antibiotics. Your doctor will then choose a different class of antibiotics to treat your infection. If no mutations are found, the bacteria should still be sensitive to fluoroquinolones, though your doctor will consider other factors when selecting treatment.

This test is very safe. You may feel a quick sting when the needle is inserted, and the puncture site may be slightly sore or bruised for a day or two. Serious problems such as infection or prolonged bleeding are rare, but let your provider know if you take blood thinners or bleed easily.

The risks associated with this test are minimal and depend primarily on the type of sample collected. The sample collection procedure carries the same small risks as any standard sample collection—such as slight pain or bruising at the needle site for blood draws, or mild discomfort during urine or tissue collection. There are no significant risks from the molecular testing itself.