Bacteriological Characteristics of Staphylococcus aureus Isolates from Humans and Bulk Milk

• Published in: Journal of dairy science Vol. 91; no. 2; pp. 564 - 569
• Main Authors: Hata, E, Katsuda, K, Kobayashi, H, Nishimori, K, Uchida, I, Higashide, M, Ishikawa, E, Sasaki, T, Eguchi, M
• Format: Journal Article
• Language: English
• Published: Savoy, IL Elsevier Inc 01.02.2008; American Dairy Science Association; Am Dairy Sci Assoc
• Subjects: Animal productions; Animals; Anti-Bacterial Agents - pharmacology; antibiotic resistance; antibiotics; Bacterial Toxins - chemistry; Bacterial Toxins - genetics; Biological and medical sciences; bulk milk; Cattle; Cattle Diseases - epidemiology; Cattle Diseases - microbiology; Cluster Analysis; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; Electrophoresis, Gel, Pulsed-Field; epidemiological studies; Female; Food industries; Food Microbiology; Fundamental and applied biological sciences. Psychology; genes; Humans; Japan - epidemiology; LukM/LukF'-PV leukotoxin gene; LukM/LukF′-PV; methicillin; methicillin-resistant staphylococcus aureus; Microbial Sensitivity Tests; microbiological quality; Milk - microbiology; pulsed-field gel electrophoresis; pulsotypes; Serotyping; Staphylococcal Infections - epidemiology; Staphylococcal Infections - microbiology; Staphylococcal Infections - veterinary; Staphylococcus aureus; Staphylococcus aureus - classification; Staphylococcus aureus - genetics; Staphylococcus aureus - isolation & purification; Terrestrial animal productions; Vertebrates; Zoonoses - epidemiology; Zoonoses - microbiology; Japan; LukM/LukF′-PV; pulsed-field gel electrophoresis; Staphylococcus aureus; Pulsed field electrophoresis; Dairy industry; Human milk; Bacteria; Micrococcales; Isolate; Micrococcaceae; Bulk; LukM/LukF'-PV
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2007-0457

The aim of this study was to clarify the epidemiological association and bacteriological characteristics of human and animal Staphylococcus aureus isolates. Pulsed-field gel electrophoresis showed that pulsotypes (PT) of isolates from bulk milk differed from PT from human isolates, suggesting that there is no epidemiological association between isolates from these 2 sources. The absence of a common PT could result from the lack of contact between the sources. Methicillin-resistant S. aureus from human secretions and S. aureus from bulk milk in Japan consisted of 1 and 2 dominant clusters, respectively, whereas methicillin-susceptible S. aureus from humans consisted of assorted clusters. Isolates belonging to the dominant clusters showed the coagulase serotype, the capsule serotype, detection of exotoxin genes, and antimicrobial susceptibility. Isolates from bulk milk did not show the penicillin-binding protein 2a gene, and 252 of 275 isolates belonging to the 2 dominant clusters of bulk milk were susceptible to ampicillin, cefazolin, erythromycin, chloramphenicol, oxacillin, and vancomycin. Moreover, the LukM/LukF′-PV leukotoxin gene was detected in 233 of 275 isolates belonging to the dominant clusters in bulk milk isolates. These results support the hypothesis that a number of factors play a role in the adaptation of S. aureus isolates to specific hosts.