title: Evaluation of Three Bacterial Identification Systems for Species Identification of Bacteria Isolated from Bovine Mastitis and Bulk Tank Milk Samples.
abstract: A study was conducted to evaluate Sensititre®Automated Reading and Incubation System 2x System (ARIS), API®(API), and Bruker MALDI-TOF MS (MALDI) bacterial species identification systems using 132 diverse bacterial isolates from bovine milk samples and bulk tank milk received at the Penn State Animal Diagnostic Laboratory. The results were compared with 16S rRNA gene sequence analysis, which served as the reference method for species identification. The ARIS, API, and MALDI identified 0%, 40%, and 33.4% of species classified as Gram-positive rod isolates belonging to genera Arthrobacter, Bacillus, Brachybacterium, Brevibacterium, and Corynebacterium, respectively. It was observed that 76.5%, 93.9%, and 96.9% of catalase-negative, Gram-positive cocci (n = 33; Aerococcus, Enterococcus, Lactococcus, Streptococcus) were correctly identified to the species level by ARIS, API, and MALDI, respectively, while 33.4%, 84.5%, and 97.7% of catalase-positive, Gram-positive cocci (n = 45; Kocuria, Staphylococcus) were correctly identified to their species by ARIS, API, and MALDI, respectively. A total of 48 isolates (Acinetobacter, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pasteurella, Providencia, Pseduomonas, Serratia) of Gram-negative bacteria were examined, of which 85.4%, 93.7%, and 95.8% of the isolates were correctly identified to the species level by ARIS, API, and MALDI, respectively. In our laboratory, the MALDI had the least costs associated with consumables and reagents compared to ARIS, API, and 16S rRNA identification methods. Identification of bacterial species was accomplished in <2 h using MALDI and 24 h for ARIS, API, and 16S rRNA identification systems.
authors.affiliation: 1 Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, Pennsylvania.
authors.forename: Emily
authors.initials: E
authors.lastname: Savage
authors.affiliation: 1 Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, Pennsylvania.
authors.forename: Shubhada
authors.initials: S
authors.lastname: Chothe
authors.affiliation: 1 Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, Pennsylvania.
authors.forename: Valerie
authors.initials: V
authors.lastname: Lintner
authors.affiliation: 1 Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, Pennsylvania.
authors.forename: Traci
authors.initials: T
authors.lastname: Pierre
authors.affiliation: 1 Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, Pennsylvania.
authors.forename: Tammy
authors.initials: T
authors.lastname: Matthews
authors.affiliation: 1 Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, Pennsylvania.
authors.forename: Subhashinie
authors.initials: S
authors.lastname: Kariyawasam
authors.affiliation: 2 Pennsylvania Veterinary Laboratory , Pennsylvania Department of Agriculture, Harrisburg, Pennsylvania.
authors.forename: Dawn
authors.initials: D
authors.lastname: Miller
authors.affiliation: 2 Pennsylvania Veterinary Laboratory , Pennsylvania Department of Agriculture, Harrisburg, Pennsylvania.
authors.forename: Deepanker
authors.initials: D
authors.lastname: Tewari
authors.affiliation: 1 Penn State Animal Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University , University Park, Pennsylvania.
authors.forename: Bhushan
authors.initials: B
authors.lastname: Jayarao
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D006090:Gram-Negative Bacteria / Q000145:classification / Q000302:isolation & purification*; D006095:Gram-Positive Cocci / Q000145:classification / Q000302:isolation & purification*; D016987:Gram-Positive Rods / Q000145:classification / Q000302:isolation & purification*; D008414:Mastitis, Bovine / Q000175:diagnosis* / Q000382:microbiology; D008892:Milk / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000302:isolation & purification; D017423:Sequence Analysis, RNA; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: bacterial species identification; milk