title: Mutans streptococci enumeration and genotype selection using different bacitracin-containing media.
abstract: The primary etiological agents associated with dental caries include the mutans streptococci (MS) comprised of Streptococcus mutans and Streptococcus sobrinus. The effective cultivation and isolation of MS are necessary for the study of MS, including their proper clinical assessment in the epidemiological study of dental caries. Several selective media have been developed for the isolation, enumeration, and characterization of MS. However, inhibition of MS may occur, reducing counts and perhaps limiting selection of some strains. The purpose of this study was to compare five culture media containing bacitracin recommended for the isolation of MS. Five commonly used bacitracin-containing media (MSB, MSKB, GTSB, TYS20B, and TYCSB) used for MS isolation were quantitatively evaluated. Standard plate counts were performed in duplicate for 2 prototype MS strains (S. mutans UA159 and S. sobrinus 6715) and for MS isolates from clinical saliva samples obtained from 16 children (approximate age 5years) to determine total plate counts, and total S. mutans counts. Selected isolates (n=249) from all five media for 5 saliva samples were further confirmed as S. mutans with real-time PCR then subsequently evaluated qualitatively with rep-PCR for genotype determination. All media resulted in variable enumeration with no significant difference in MS counts. MS prototype strains grew well on all five media; clinical isolates demonstrated more variability in counts but no overall significant differences were found. MSB demonstrated comparable ability to grow S. mutans but allowed for more non-S. mutans growth. All 5 media identified a consistent predominant genotype by rep-PCR. Recovery of minor genotypes was not inhibited by media type.
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, University of Alabama at Birmingham, SOD 304, 1720 2nd Avenue South, Birmingham, AL 35294-0007, USA. Electronic address: sks@uab.edu.
authors.forename: Stephanie S
authors.initials: SS
authors.lastname: Momeni
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, University of Alabama at Birmingham, SOD 304, 1720 2nd Avenue South, Birmingham, AL 35294-0007, USA. Electronic address: paul.patrick53@yahoo.com.
authors.forename: Paul
authors.initials: P
authors.lastname: Patrick
authors.affiliation: Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, RPHB 217D, 1720 2nd Avenue South, Birmingham, AL 35294-0022, USA. Electronic address: hwiener@uab.edu.
authors.forename: Howard W
authors.initials: HW
authors.lastname: Wiener
authors.affiliation: Department of Biostatistics, School of Public Health, University of Alabama at Birmingham, RPHB 327, 1720 2nd Avenue South, Birmingham, AL 35294-0022, USA. Electronic address: cutterg@uab.edu.
authors.forename: Gary R
authors.initials: GR
authors.lastname: Cutter
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, University of Alabama at Birmingham, SOD 304, 1720 2nd Avenue South, Birmingham, AL 35294-0007, USA. Electronic address: johnruby@uab.edu.
authors.forename: John D
authors.initials: JD
authors.lastname: Ruby
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, University of Alabama at Birmingham, SOD 304, 1720 2nd Avenue South, Birmingham, AL 35294-0007, USA. Electronic address: kcheon@uab.edu.
authors.forename: Kyounga
authors.initials: K
authors.lastname: Cheon
authors.affiliation: Department of Pathology, School of Medicine, University of Alabama at Birmingham, WP P230, 1720 2nd Avenue South, Birmingham, AL 35294-7331, USA. Electronic address: jenndoc@uab.edu.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Whiddon
authors.affiliation: Department of Pathology, School of Medicine, University of Alabama at Birmingham, WP P230, 1720 2nd Avenue South, Birmingham, AL 35294-7331, USA. Electronic address: moser@uab.edu.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Moser
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, University of Alabama at Birmingham, SOD 304, 1720 2nd Avenue South, Birmingham, AL 35294-0007, USA. Electronic address: nkc@uab.edu.
authors.forename: Noel K
authors.initials: NK
authors.lastname: Childers
mesh_terms: D001414:Bacitracin / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D058491:Bacterial Load; D002675:Child, Preschool; D003470:Culture Media / Q000737:chemistry; D003731:Dental Caries / Q000382:microbiology; D005838:Genotype; D060005:Genotyping Techniques; D006801:Humans; D012641:Selection, Genetic / Q000187:drug effects; D013295:Streptococcus mutans / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*
chemical_list: D003470:Culture Media; D001414:Bacitracin
keywords: Genotypes; Selective media; Streptococcus mutans; Streptococcus sobrinus; Total streptococci; rep-PCR