Daniel S. Shapiro, MD

Wendy B. Gillespie, MT, ASCP

Culture tubesThe Microbiology Laboratory is one of many labs at Lahey Hospital. The main purpose of this laboratory is to assist in the diagnosis of infectious diseases. This starts with the patient entering the healthcare system and presenting with certain signs and symptoms consistent with an infectious disease. The patient’s physician then orders specific tests to clarify the presence of an infectious disease. These diseases can include those caused by bacteria (e.g., Group A streptococcus that may cause strep throat); those caused by viruses (e.g., influenza A that cause the flu); those caused by fungi (e.g., Candida, which may cause vaginal yeast infections); or those caused by parasites (e.g., Giardia, which may cause diarrhea).

Microbiology Lab StaffA range of personnel performs testing and oversees the Microbiology Laboratory. Medical technologists, who are highly trained professionals and have bachelor’s degrees in medical technology or microbiology, perform the daily testing. The lab is directed by a board-certified physician with specialty training in microbiology and infectious diseases.

Examining bacterial growth on culture platesIn order for microbiology to aid in diagnosing the correct infectious disease, a number of steps occur. The first step is the collection of the appropriate specimens to diagnose the patient’s disease. For instance, if an infection of the bladder is a possibility, the physician may order a urinalysis that looks at the cell types present in the urine, such as red and white blood cells, as well as a urine specimen for a culture to grow the organism that is causing the infection.

Specimens may be collected from a number of different sources, including blood, urine, and swab specimens of the throat. Sometimes a more invasive technique using a needle or other special instrument is required to collect the specimen. This first step in microbiology diagnosis of infectious disease is very important! A good quality specimen means the best chance of diagnosing the infectious disease.

Bacterial culture plates, Organism identification test strip, Antibiotic sensitivity plate (Disk Diffusion Test)After the collection of the specimen and input from the physician about what the possible infectious disease may be, the laboratory decides what technique is best to identify the infectious disease and the organism likely causing the problem. All of the techniques look for some product of an organism. The time it takes to identify the organism is dependent on the technique used, as well as how complicated the testing process may be. For the patient, this means the lab may be able to provide an answer in anywhere from 15 minutes to eight weeks!

Recommended Web Site

ASM Website

The American Society for Microbiology represents 25 disciplines of microbiological specialization plus a division for microbiology educators. Microbiologists study microbes–bacteria, viruses, rickettsiae, mycoplasma, fungi, algae and protozoa–some of which cause diseases, but many of which contribute to the balance of nature or are otherwise beneficial. Microbiological research includes infectious diseases, recombinant DNA technology, alternative methods of energy production and waste recycling, new sources of food, new drug development, and the etiology of sexually transmitted diseases, among other areas. Microbiology is also concerned with environmental problems and industrial processes.