Microbiology Laboratory Transport Media - PDF

Microbiology Laboratory Dr. Basma Samir (MD)  TRANSPORT MEDIA for MICROBIOLOGY SAMPLES 1 What samples are collected in transport medium? 2 All types of samples that may have pathogens but cannot be processed imm...

Microbiology Laboratory Dr. Basma Samir (MD)  TRANSPORT MEDIA for MICROBIOLOGY SAMPLES 1 What samples are collected in transport medium? 2 All types of samples that may have pathogens but cannot be processed immediately after collection require transport medium. It may be urine, stool, blood, urethral swabs, nasal and throat swabs, bronchial and alveolar lavage, eye and ear secretions, wound, etc. Transport Media Used in Microbiology Lab 3 The primary objective of using the transport medium is to maintain the specimen as near its original state as possible. What does transport media contain? 4 Transport media are solutions of buffers with carbohydrates, peptones, and other nutrients (excluding growth factors) designed to preserve the viability of bacteria during transport without allowing their growth from the time of collection to that of processing. They do not contain nutritional ingredients such as carbon, nitrogen, or organic growth factors to prevent microbial multiplication. Transport Media Used in Microbiology Lab 5 Selection of transport media may vary depending on the type of organisms suspected. However, transport media are classified based on Physical state as Semi-solid and Liquid Type of suspected microbe as bacteria (aerobic & anaerobic) or viruses. Common Transport media 6 Stuart Transport Medium Commonly used for throat, wound, and skin swabs that may contain ❑ Fastidious organisms ❑ Specimens suspected of having gonococci. 7  Amies medium With Charcoal; helps eliminate metabolic products of bacterial growth, which may be especially useful in isolating fastidious organisms. Without charcoal; These are ideal for isolating Mycoplasma. 8 Cary and Blair Medium Semi-solid, white-colored transport medium for feces that may contain Salmonella, Shigella, Vibrio, or Campylobacter. Cary Blair media is the ideal and WHO-recommended media for transporting Vibrio cholerae. 9  Blood Culture Transport Medium TYPE oF CONTAINER AMOUNT OF BLOOD ROUTE CULTURE Aerobic Blue top Bottle 8-10 cc. Blood Peripheral or Line Anaerobic Fuchsia top Bottle 8-10 cc. Blood Peripheral or Line Fungus Blue top Bottle 8-10 cc. Blood Peripheral or Line TB or AFB or 2 green Vacutainer 7-10 cc. Blood Peripheral or Line Mycobacterium Tubes (Heparin) Pediatric Yellow top Bottle 1-2 cc. Blood Peripheral or Line 10 Blood Culture  Anaerobic Transport Medium (ATM) 11 Maintains viability of most microorganisms through collection & transport of clinical specimens without multiplication. Meets the viability requirements of obligate anaerobes. Prepared, dispensed, & packaged under oxygen- free conditions.  Anaerobic Transport Medium (ATM) 12 Available in multiple sizes & configurations, including sterile surgery packs. Provides an environment that maintains viability without multiplication of anaerobic bacteria. Contains buffered mineral salts in a semi-solid media, with reducing agents (sodium thioglycollate & cysteine).  Anaerobic Transport Medium (ATM) 13 An indicator is added to reveal exposure to oxygen by turning pink. Tubes have caps containing a rubber septa, which allow for direct injection of clinical specimens, introduction of tissue samples, or stabbing w/ swabs. Examples include thioglycolate broth.  Common Transport media Alkaline Peptone Water (APW) Used to transport Vibrio cholerae only when the Cary-Blair medium is not available, and subculture can be done within 6 hours of sample collection. pH is adjusted to 8.4 The alkaline pH of this medium allows the growth of Vibrio organisms while inhibiting the growth of commensal intestinal bacteria. 14 Common Transport media 15 Sach’s buffered glycerol saline Used to transport feces from patients suspected of suffering from bacillary dysentery.  Viral Transport Medium (VTM) Ideal for transporting samples for the diagnosis of viral infections. Viral Transport Media (VTM) are necessary for the transport of nasopharygeal /oropharygeal swabs. Ocular, respiratory, peritoneal and tissue swabs can be submitted in this medium. 16 Viral Transport Medium (VTM) 17 VTM contains antibiotics and antimycotics to suppress bacterial and fungal contamination. It contains phenol red as pH indicator to ensure medium integrity at time of specimen collection (Above pH 8.2 the dye turns a bright fuchsia color). Bacterial transport media are not appropriate for recovering viral pathogens. Guidelines for Specimen Transport 18 Use universal precautions for collecting and handling all specimens. Whenever possible, collect all culture specimens prior to administration of any antimicrobial agents. Avoid contamination with indigenous flora. Swabs are convenient but inferior to tissue and fluid. Tissue and fluid are essential for fungal and mycobacterial culture. Guidelines for Specimen Transport 19 All specimens must be appropriately labeled with two patient identifiers. “patient name, birthdate and/or hospital number”. The requisition will include patient’s name, hospital number, hospital service, date and time of collection, specimen type and tests requested. A requisition needs to accompany each different specimen type. Guidelines for Specimen Transport 20 Deliver all specimens to the laboratory as soon as possible after collection. Specimens for bacterial culture should be transported at room temperature. If transport is delayed, the following specimens should be refrigerated: urines (within 30 min), stool (within 1 h), respiratory specimens. Specimens for viral culture must be transported to the laboratory immediately on ice. Guidelines for Specimen Transport 21 Specimens should be collected in; tightly sealed, leak proof containers and transported in sealable, leak-proof plastic bags. Specimens for TB should be transported double bagged. If anaerobic culture is requested, make certain to use proper anaerobic collection containers. Further questions may be referred to the Microbiology laboratory.  22 THANK YOU