Question

hey guys give me a short note on mycoplasma--kh__iii2796​

Answer 1

Añńeyong.....♡

Specimen Collection and Transport

For the detection of most viruses, specimens collected soon after the onset of clinical symptoms (preferably within the first 3–4 days) when viral shedding is greatest are preferred. Optimal specimens vary depending on the site or sites of disease. In general, tissues, aspirates, and body fluids are superior to swabs. Body sites or lesions that can be sampled easily with a swab include the pharynx or nasopharynx, conjunctiva, urethra, cervix, vagina, and vesicles or ulcers on the skin or mucous membranes. Many swabs types are available for specimen collection, including plastic swabs, wooden swabs, and swabs with a flexible wire shaft and a tip made of cotton, Dacron, calcium alginate, or polyurethane,7 although not all are suitable for detection of some viruses. Swabs with a wooden shaft can contain toxic products that inactivate herpes simplex virus (HSV). Cotton-tipped swabs can contain fatty acids that can interfere with the survival of Chlamydia species, but they are suitable for the collection of specimens from the vagina, cervix, or urethra for the detection of Mycoplasma. Calcium alginate–tipped swabs can be toxic for lipid-enveloped viruses such as herpesviruses and some cell cultures, but they are useful for the collection of specimens for Chlamydia. Although swabs placed in a viral transport medium (VTM) can be used for NAATs, many commercial assays for detection of viruses and Chlamydia provide their own swab and transport media, which should be used.

Swabs and tissues for detection of viruses should be placed into VTM to prevent drying, maintain virus viability, and prevent the overgrowth of contaminating organisms.7 Several commercially prepared VTMs are available.7 Swabs collected for bacterial isolation that are placed in bacterial transport medium are unacceptable for detection of viruses.7 Conversely, VTM contains antimicrobial agents that inhibit most bacteria and fungi. Specimens such as blood, bone marrow, cerebrospinal fluid (CSF), urine, and other body fluids should be placed in clean, sterile containers without VTM.

For detection of most respiratory viruses, a nasopharyngeal (NP) aspirate or wash, sputum, or bronchoalveolar lavage (BAL) specimen provides a better yield for detection of viruses than NP, nasal, or throat swabs.7 Multiple samples can be required to maximize yield. Freshly passed stool is superior to a rectal swab for detection of gastrointestinal viruses.7

Specific viruses can be found in different blood cells, the plasma or serum, or both (e.g., HIV in lymphocytes and macrophages, CMV in neutrophils and to a lesser extent in mononuclear cells, enteroviruses in plasma and white blood cells).8,9 Blood should be collected into Vacutainer tubes containing an anticoagulant such as ethylenediaminetetraacetic acid (EDTA). Recovery rates are higher with EDTA than with heparin.10 Heparin can inactivate herpesviruses and can inhibit some NAATs11,12; this issue may be less of a concern for real-time polymerase chain reaction (PCR) and can be related to the type of heparin (sodium vs. lithium) used.13,14

For tissue specimens or when the lability of particular viruses (e.g., respiratory syncytial virus [RSV] or varicella-zoster virus [VZV]) is a concern, VTM containing albumin or serum as a stabilizer should be used.

Most viruses are stable for 2 to 3 days at 4°C (refrigerator or wet ice temperature).7 Freezing at −20°C (ordinary freezer temperature) destroys or reduces the infectivity of most viruses and can alter the ability to detect viral antigen when using some commercially available kits. Beyond 2 to 3 days, specimens should be stored in an ultralow-temperature freezer (−70°C) and transported on dry ice. For some NAATs (e.g., detection of hepatitis C virus [HCV] RNA in serum or plasma), serum or plasma should be separated within 4 to 6 hours of collection and processed within 72 hours (if kept at 2°C–8°C) or frozen at −70°C until tested.7

For serologic detection of viral antibodies or antigen, blood can be transported at room temperature. If a delay is anticipated, the specimen should be kept refrigerated at 2°C to 8°C. Serum or plasma should be separated as soon as possible after specimen collection. If an extended period will elapse before testing, the serum or plasma sample should be frozen at −20°C or lower. Repeated freeze-thaw cycles should be avoided. For viruses for which an IgM assay is available (e.g., hepatitis A virus [HAV]), an acute phase specimen can be sufficient for diagnosis. Otherwise, an acute phase specimen is collected within a few days of illness onset and serum is stored, followed by collection of a convalescent phase specimen 2 to 4 weeks later, and the specimens are tested simultaneously.

Hope it helps uh...!