1. Specimens Throat swab Pus Cerebrospinal fluid Blood Serum for antibody determinant 2. Smear Gram staining Purple color cocci in chain arrangement Not to be confused with Viridans Streptococci from throat swab sample since both have same appreance 3. Culture … Read more
Specimens: stool, mucus flecks, and rectal swabs for culture. Large numbers of fecal leukocytes and some red blood cells often are seen microscopically. Microscopic examination Microscopic examination of stool smears reveals higher number of PMN cells. They are Gram negative … Read more
Laboratory diagnosis of Francisella tularensis Specimen Scrapings from infected ulcers, lymph node biopsies, and sputum, whole blood. Serum is generally collected from all patients early in disease and during convalescence. To minimize the loss of viable organisms, samples should be … Read more
Laboratory diagnosis of Legionella pneumophila Specimen: Respiratory secretions (sputum, bronchial aspirate or washings), as well as pleural fluid, lung biopsy or autopsy material. Microscopy Legionellae in clinical specimens stain poorly with Gram stain and the small, intracellular bacteria are rarely … Read more
Laboratory diagnosis of Leprosy caused by Mycobacterium leprae Specimen Skin biopsies, nasal discharges, scrapings from the nasal mucosa and slit-skin smears which are prepared by making superficial incisions in the skin, scraping out some tissue fluid and cells. Skin smears … Read more
Laboratory diagnosis of Mycoplasma pneumoniae Specimen Ideal specimens are throat swabs and nasopharyngeal aspirates, lung biopsies, expectorated sputum. Washings are more reliable than sputum specimens because most infected patients have a dry, nonproductive cough and do not produce sputum. Microscopy … Read more
Laboratory diagnosis of Streptococcus pneumoniae Specimen: Sputum, blood, endotracheal aspirate, bronchoalveolar lavage, cerebrospinal fluid (CSF), pleural fluid, joint fluid, abscess fluid, bones, and other biopsy material. Microscopy Gram staining of sputum shows lancet shaped Gram-positive cocci in pairs. Fresh emulsified … Read more
Laboratory diagnosis of Leptospira interrogans Specimens Specimens consist of aseptically collected blood in a heparin tube, CSF, urine, or tissues for microscopic examination and culture. Serum is collected for agglutination tests. Microscopy As leptospires are thin, they are at the … Read more
Laboratory diagnosis of Borrelia burgdorferi Specimen Blood, cerebrospinal fluid, joint fluid, tissue biopsies Body fluids should be transported without any preservatives. Tissue biopsy specimens should be placed in sterile saline to prevent drying. Direct detection methods The organisms can be … Read more
Laboratory diagnosis of Rickettsia rickettsii Specimen: Skin biopsies, serum Direct detection method Although Rickettsiae stain poorly with Gram stain, they can be stained with Giemsa or Gimenez stains. Direct detection of R. rickettsii antigen in skin biopsy specimens of the rash from … Read more
Laboratory diagnosis of Corynebacterium diphtheriae Specimen Dacron swabs from the nose, throat, or other suspected lesions must be obtained before antimicrobial drugs are administered. Swabs should be collected from beneath any visible membrane. The swab should then be placed in semisolid … Read more
Laboratory diagnosis of Syphilis caused by Treponema pallidum Specimen Samples collected from ulcers and lesions should not be contaminated with blood, microorganisms, or tissue debris. Polymerase chain reaction (PCR) samples should be collected on a sterile Dacron or cotton swab … Read more
Laboratory diagnosis of Listeriosis caused by Listeria monocytogenes Specimens: Cerebrospinal fluid (CSF), Blood Microscopy Gram-stain preparations of cerebrospinal fluid (CSF) typically show no organisms because the bacteria are generally present in concentrations below the limit of detection (e.g., 10ˆ4 bacteria per … Read more
Laboratory diagnosis of Bacterial vaginosis caused by Gardnerella vaginalis Specimen: Vaginal discharge specimen A. Direct Microscopic Examination Bacterial Vaginosis (BV) is characterized by a foul-smelling discharge. A diagnosis/confirmation is done microscopically by examination of gram stains to detect change in … Read more