Gram Stain – Conjunctival Swab
Why Gram Stain (Conjunctival Swab) Test?
CLINICAL INFORMATION
Staphylococcal infection (caused by gram-positive bacteria) is the major bacterial pathogen affecting the eye involved in staphyloma. Some common diseases of the eye include conjunctivitis (also referred to as pink eye is common in children and elderly people), blepharitis, endophthalmitis, keratitis, dacryocystitis, orbital cellulitis etc. Some of the common clinical manifestations include red eye, excessive tears of eyes, thick yellow discharge, formation of crust around the eyes after a nap, burning and/or itchy eyes etc. Conjunctivitis can be caused due to various reasons eg. bacteria, viruses, allergies and excessive use of contact lenses etc. Since conjunctivitis is highly contagious and moreover its treatment modalities of eye infection are strictly based on their identification of the causative organism, culture and sensitivity tests become mandatory.Culture and Sensitivity (Conjunctival Swab) testis used for isolation and identification of pathogenic microbes such as bacteria like staphyloma, fungi and/ viral such as herpes viral infection etc. Several indications for taking swabs sample specimens for the identification of organisms from the conjunctiva and cornea are indicated in certain suspected infections like Neisseria gonorrhea infection, Chlamydia etc. Conjunctival scraping and the cultures are frequently obtained if there is corneal involvement (especially when the central cornea is affected) or multiple keratitis lesion or corneal ulcer (2mm or larger) are present or in cases where anti-bacterial therapy is ineffective. Complications of untreated or chronic cases may lead to irreversible damage to the eye and can result in blindness. Other tests include tests on sample specimen like blood, urine, stool etc, glucose, blood pressure, clinical assessment by optholmologist using specialized optholmogical equipments such as slit lamp and binocular indirect opthalmoscope, retinoscope and direct optholmoscope, keratometer, tonometer etc.Gram Stain Test: This test checks for the presence of harmful pathogenic microbes in suspected infection, for example in the throat, lungs, skin wounds, genitals etc and moreover in body fluids such as blood, urine etc. The two main categories of bacterial infections are gram-positive and gram-negative. This screening for diagnosis is done by the differentiation made, based on how the bacteria react to the gram stain. A gram stain is coloured purple and if the bacteria remain in purple colour it is gram-positive bacteria and incases the bacteria turns red or pink they are gram-negative bacteria. Examples of gram-positive bacteria include nosocomial infection caused by Methicillin-Resistant Streptococcus aureus (MRSA), Strep infections, toxic shock etc. Examples of gram-negative infections include Salmonella, pneumonia, gonorrhea, UTI etc. The significance of differentiating the nature of bacteria as gram-positive or gram-negative helps the physician to begin the most effective antibiotic therapy for treating it. If the test result shows the presence of more than (≥15) colonies along with the same organism isolated from peripheral blood along with clinical signs and symptoms, then the case is said to be an infected positive case. Other gram stain tests include the Acid Fast Test (eg. For mycobacterium causing TB etc). Clinical manifestations include chills, fever, fatigue, nausea, confusion, increased heart rate, nasal flare due to increased breathing -which may or may not be associated with shortness of breath on physical exertion, inflammation (presenting with cardinal signs of inflammation like – rubor, tumour, calor, dolor and loss of function), blood clots, drop in blood pressure, organ failure, elevated WBCs etc. Once tested positive, then the additional supportive tests are ordered for - Evidence-Based Therapy (EBT) such as CBC, test for the presence of bacterial toxins (release of toxic by-products) eg staphylococcal infection, in case of foodborne-illness/food poison (or their toxins), different sample specimen collected for tests eg. blood, stool, urine culture, sputum test, CSF sampling, ascetic fluid, pleural fluid, pericardial fluid, synovial fluid, complement test (to check for increased levels of C3) etc. Moreover, sensitivity tests (also known as susceptibility testing) are also performed for appropriate antibiotic treatment & for better prognosis eg. MRSA – Methicillin-Resistant Staphylococcus aureus, VMSA Vancomycin-Resistant Staphylococcus aureus etc. Other tests other than culture and sensitivity of semen for the source of infection includes microscopic examination and evaluation of semen analysis, blood tests like CBC, differential WBC count (in case of infection), Prostate-Specific Antigen test, testosterone, FSH, ELISA test for Mumps antibodies etc, other hormonal assays eg. pituitary hormones (in case of tumours etc), urinalysis to check for UTI, digital rectal examination to confirm pain and swelling of the prostate, CT Scan, ultrasound (vericocele), genetic tests like DNA etc.
General Instructions:
Sample Requirement: Specimen – conjunctival swab. Test Preparation: None.
NOTE - Sample for specimen collections may vary based on the patient’s condition/cases according to the patient’s presenting complaints/signs or symptoms:
SPECIMEN REQUIREMENT (Special or Rare Cases) - As instructed and guided by Physician / Clinician / Pathologist / as per Laboratory’s requirements, according to procedures and protocols.
This Multi-Specialty Clinical Referral Laboratory RT DIAGNOSTICS provides precise and accurate tests with an extensive range of testing services to the medical centres to help in the diagnosis and identification of pathology in the test specimens for infectious diseases and also to evaluate the function of organ systems of the patient. It prevents further complications and helps to stabilize and restore health to near normalcy at the earliest without delay.
