Bacteriology Section
The Bacteriology and Parasitology section performs a wide range of diagnostic testing. Specimens are accepted from public and private agencies, hospitals, clinics, and doctor’s offices. Specimens may be from humans, animals, the environment, or foods. We have surge capacity for testing during outbreaks or increased incidence. We provide telephone consultation and referral of unusual specimens to the CDC. The following is a brief description of the services that we provide.
DNA probe testing for Neisseria gonorrhoeae and Chlamydia trachomatis
The amplified probe is offered for use on routine screening of endocervical and urethral swab specimens as well as male and female urine specimens.
Parasitic Diseases
The laboratory no longer routinely offers this service. Please call for assistance during outbreaks or in identifying unusual parasites.
Reference Bacteriology Isolation, identification, serogrouping, and serotyping of bacterial species from submitted samples or reference culture.
Virology Section
The virology section isolates and identifies viruses, antibodies, and antigens from submitted samples.
Strain Identification Using
Pulsed Field Gel Electrophoresis
Strain typing is used to determine relatedness of isolates in a suspected outbreak. All species of microorganisms have a large number of strains that are identifiable by alterations in their genomes. Phenotypic characteristics defined by techniques such as bacterial biotyping, antibiograms, serotyping, and bacteriophage typing have been used to identify strains. Pulsed field gel electrophoresis (PFGE) is a method of strain identification based on analysis of the genomic DNA of an isolate of an organism. The genomic DNA is digested with restriction enzymes into fragments that are electrophoretically separated on an agarose gel. The stained gel is photographed and the resulting “DNA fingerprint” can be compared to that of other isolates to determine their probable relatedness.
The Maine HETL is currently an active participant of PulseNET. PulseNET is a national network of public health laboratories that perform DNA fingerprinting on food-borne bacteria. The network permits rapid comparison of obtained patterns through an electronic database at the Centers for Disease Control and prevention (CDC). The food-borne bacterial pathogens currently being DNA sub-typed by the HETL are E. coli O157:H7, Salmonella typhimurium, and other Salmonella serotypes. Other foodborne pathogens for which we have the capacity to type by PFGE are Listeria and Shigella species.
