title: Performance of culture media for the isolation and identification of Staphylococcus aureus from bovine mastitis.
abstract: Rapid isolation and identification of pathogens is a major goal of diagnostic microbiology. In order to isolate and identify Staphylococcus aureus, a number of authors have used a variety of selective and/or differential culture media. However, to date, there are no reports comparing the efficacy of selective and differential culture media for S. aureus isolation from bovine mastitis cases using the 16S rRNA (rrs) gene sequence as a gold standard test. In the present study, we evaluated the efficacy of four selective and/or differential culture media for the isolation of S. aureus from milk samples collected from cows suffering from bovine mastitis. Four hundred and forty isolates were obtained using salt-mannitol agar (SMA, Bioxon), Staphylococcus-110 agar (S110, Bioxon), CHROMAgar Staph aureus (CSA, BD-BBL) and sheep's blood agar (SBA, BD-BBL). All bacterial isolates were identified by their typical colony morphology in the respective media, by secondary tests (for coagulase and β-haemolysis) and by partial 16S rRNA (rrs) gene sequencing as a gold standard test. Sensitivity, positive predictive and negative predictive values were higher for SMA (86.96, 52.63 and 95.95%, respectively) compared with S110 (70.00, 23.73 and 90.91%, respectively), CSA (69.23, 28.13 and 95.74%, respectively) and SBA (68.75, 37.93 and 89.58%, respectively) while specificity values were similar for all media. Data indicated that the use of culture media for S. aureus isolation combined with determination of coagulase activity and haemolysis as secondary tests improved accuracy of the identification and was in accordance with rrs gene sequence-analysis compared with the use of the culture media alone.
authors.affiliation: Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán, México.
authors.forename: G U
authors.initials: GU
authors.lastname: Bautista-Trujillo
authors.affiliation: Unidad de Servicios de Apoyo al Diagnóstico, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán, México.
authors.forename: J L
authors.initials: JL
authors.lastname: Solorio-Rivera
authors.affiliation: Unidad de Servicios de Apoyo al Diagnóstico, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán, México.
authors.forename: I
authors.initials: I
authors.lastname: Rentería-Solórzano
authors.affiliation: Unidad de Servicios de Apoyo al Diagnóstico, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán, México.
authors.forename: S I
authors.initials: SI
authors.lastname: Carranza-Germán
authors.affiliation: Departamento de Atención a la Salud, Universidad Autónoma Metropolitana-Xochimilco, Coyoacán, México.
authors.forename: J A
authors.initials: JA
authors.lastname: Bustos-Martínez
authors.affiliation: Centro Nacional de Recursos Genéticos, Instituto Nacional de Investigaciones Forestales y Agropecuarias, Tepatitlán de Morelos, Jalisco, México.
authors.forename: R I
authors.initials: RI
authors.lastname: Arteaga-Garibay
authors.affiliation: Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán, México.
authors.forename: V M
authors.initials: VM
authors.lastname: Baizabal-Aguirre
authors.affiliation: Instituto de Investigaciones Agropecuarias y Forestales, Universidad Michoacana de San Nicolás de Hidalgo, La Palma, Tarímbaro, Michoacán, México.|Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán, México.
authors.forename: M
authors.initials: M
authors.lastname: Cajero-Juárez
authors.affiliation: Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán, México.
authors.forename: A
authors.initials: A
authors.lastname: Bravo-Patiño
authors.affiliation: Centro Multidisciplinario de Estudios en Biotecnología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Tarímbaro, Michoacán, México.
authors.forename: J J
authors.initials: JJ
authors.lastname: Valdez-Alarcón
mesh_terms: D000818:Animals; D001431:Bacteriological Techniques / Q000662:veterinary; D002417:Cattle; D003470:Culture Media / Q000737:chemistry*; D005260:Female; D008414:Mastitis, Bovine / Q000382:microbiology*; D008969:Molecular Sequence Data; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000145:classification* / Q000302:isolation & purification*
chemical_list: D003470:Culture Media