Comparison of methods for the detection of methicillin resistance in Staphylococcus aureus isolates from food products |
| |
Authors: | Corrente M Normanno G Martella V Bellacicco A L Quaglia N C Dambrosio A Buonavoglia D D'Abramo M Buonavoglia C |
| |
Affiliation: | Department of Health and Animal Well-being, Faculty of Veterinary Medicine, University of Bari, Str. prov per Casamassima, km. 3, Valenzano, Bari, Italy. m.corrente@veterinaria.uniba.it |
| |
Abstract: | AIMS: To compare several methods for detection of methicillin resistance in Staphylococcus aureus isolates from food. METHODS AND RESULTS: Two hundred S. aureus isolates from food of animal origin were screened for methicillin resistance by a PCR assay specific for the mecA gene, an oxacillin agar screen test and a cefoxitin disk diffusion test. Six out of 200 strains (3%) were found to be methicillin-resistant Staphylococcus aureus (MRSA) by PCR. The oxacillin agar screen test detected only one of the MRSA isolates (sensitivity of 16.7%) and mischaracterized three additional strains as MRSA (specificity of 98.45%). None of the MRSA strains was detected by the cefoxitin test (sensitivity of 0%), while 15 methicillin-susceptible S. aureus (MSSA) strains were misclassified as resistant (specificity of 92.3%). Fifteen MSSA strains displayed a beta-lactamase hyperproducer-like phenotype. The six MRSA (mecA-positive) strains resembled the characteristics of heteroresistant strains. CONCLUSIONS: As MRSA of animal origin may display atypical phenotypes, PCR appears to be more reliable for detection of methicillin resistance in animal strains. SIGNIFICANCE AND IMPACT OF THE STUDY: The study stresses the need for implementing the methods of screening S. aureus from food of animal origin for methicillin resistance. |
| |
Keywords: | food products methicillin resistance Staphylococcus aureus |
本文献已被 PubMed 等数据库收录! |
|