RRC ID 41235
Author Seier-Petersen MA, Nielsen LN, Ingmer H, Aarestrup FM, Agersø Y.
Title Biocide Susceptibility of Staphylococcus aureus CC398 and CC30 Isolates from Pigs and Identification of the Biocide Resistance Genes, qacG and qacC.
Journal Microb. Drug Resist.
Abstract OBJECTIVES:Methicillin-resistant Staphylococcus aureus (MRSA), in particular clonal complex (CC) 398, is increasingly found in livestock. Recently, MRSA CC30 was identified in Danish pigs. We determined the susceptibility of porcine S. aureus isolates of CC398 and CC30 to disinfectants used in pig farming (benzalkonium chloride, hydrogen peroxide, formaldehyde, sodium hypochlorite, and caustic soda). Furthermore, efflux pump activity, antimicrobial resistance profiles, hemolysis properties, and the presence of toxic shock syndrome toxin-1 (TSST-1) and Panton-Valentine Leukocidin (PVL)-encoding virulence factors were investigated.
METHODS:Susceptibilities to biocides and antimicrobial agents of 79 porcine S. aureus isolates were determined by the microdilution method. Isolates comprised 21 methicillin-sensitive S. aureus (MSSA) and 40 MRSA isolates belonging to CC398 and 13 MSSA and 5 MRSA isolates belonging to CC30. The presence of quaternary ammonium compound (QAC) resistance efflux pumps was analyzed using an ethidium bromide accumulation assay. The presence of qac resistance genes in active efflux pump positive isolates was determined by whole-genome sequencing data. All isolates were screened for lukPV and tst genes with PCR, and hemolytic activities were determined using an agar plate assay.
RESULTS:S. aureus isolates did not show reduced susceptibility to the biocides tested. However, the QAC resistance gene, qacG, was detected in three MRSA CC30 isolates and the qacC in one MRSA CC30 isolate. CC30 isolates were generally more susceptible to non-beta-lactam antibiotics than CC398. Isolates generally had low hemolytic activity and none encoded PVL or TSST-1.
CONCLUSION:The presence of qac genes in European porcine S. aureus isolates and in livestock-associated MRSA CC30 is for the first time described in this study. This finding is concerning as it ultimately may compromise disinfection with QACs and thereby contribute to the selection and spread of MRSA CC30.
Volume 21(5)
Pages 527-36
Published 2015-10
DOI 10.1089/mdr.2014.0215
PMID 26430941
MeSH Animals Anti-Bacterial Agents / pharmacology* Bacterial Proteins / genetics* Bacterial Proteins / metabolism Benzalkonium Compounds / pharmacology Disinfectants / pharmacology* Erythrocytes / drug effects Formaldehyde / pharmacology Gene Expression Hemolysis / drug effects High-Throughput Nucleotide Sequencing Membrane Transport Proteins / genetics* Membrane Transport Proteins / metabolism Methicillin-Resistant Staphylococcus aureus / drug effects Methicillin-Resistant Staphylococcus aureus / genetics* Methicillin-Resistant Staphylococcus aureus / isolation & purification Methicillin-Resistant Staphylococcus aureus / pathogenicity Microbial Sensitivity Tests Polymerase Chain Reaction Protein Isoforms / genetics Protein Isoforms / metabolism Quaternary Ammonium Compounds / pharmacology Sheep Sodium Hypochlorite / pharmacology Staphylococcal Infections / microbiology Staphylococcal Infections / pathology Staphylococcal Infections / veterinary* Swine Swine Diseases / microbiology* Swine Diseases / pathology Virulence Factors / genetics Virulence Factors / metabolism
IF 2.344
Times Cited 0
General Microbes JCM 16555 JCM 16556