Reduced vancomycin susceptibility in porcine ST9 MRSA isolates
Porcine strains of livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) have been recognized in many countries and have been shown to be able to cause human infection. Resistance to non-beta lactam antibiotics has been reported but non-susceptibility to vancomycin, which is kno...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2013-10-01
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| Series: | Frontiers in Microbiology |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fmicb.2013.00316/full |
| _version_ | 1818025805021708288 |
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| author | Gabriella Mei Lan Kwok Margaret May O'Donoghue Vijaya Chandranna Doddangoudar Jeff eHo Maureen Valerie Boost |
| author_facet | Gabriella Mei Lan Kwok Margaret May O'Donoghue Vijaya Chandranna Doddangoudar Jeff eHo Maureen Valerie Boost |
| author_sort | Gabriella Mei Lan Kwok |
| collection | DOAJ |
| description | Porcine strains of livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) have been recognized in many countries and have been shown to be able to cause human infection. Resistance to non-beta lactam antibiotics has been reported but non-susceptibility to vancomycin, which is known to occur in human MRSA, has so far not been observed in LA-MRSA. Such resistance is typically fairly low level involving changes in the cell wall thickness. The development of resistance is usually preceded by presence of a sub-population having an increased MIC, which is selected for by exposure to vancomycin. This study investigated vancomycin susceptibility of one hundred porcine MRSA isolates using three MIC methods including spiral gradient endpoint (SGE) technique which allows visualization of more resistant sub-populations. SGE revealed 16 strains with an MIC above 2.0 mg/L, of which 14 were determined to have MIC 4 mg/L by agar dilution. SGE revealed a further two isolates with MIC 2 mg/L. In addition, trailing endpoints not reaching resistance were present in 26 isolates with MIC 1.5 mg/L, the presence of vancomycin non-susceptibility in porcine isolates is of concern and further monitoring of LA-MRSA is essential. |
| first_indexed | 2024-12-10T04:21:56Z |
| format | Article |
| id | doaj.art-273bea9321934977a51b13a99698886b |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-12-10T04:21:56Z |
| publishDate | 2013-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-273bea9321934977a51b13a99698886b2022-12-22T02:02:23ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2013-10-01410.3389/fmicb.2013.0031654873Reduced vancomycin susceptibility in porcine ST9 MRSA isolatesGabriella Mei Lan Kwok0Margaret May O'Donoghue1Vijaya Chandranna Doddangoudar2Jeff eHo3Maureen Valerie Boost4The Hong Kong Polytechnic UniversityThe Hong Kong Polytechnic UniversityThe Hong Kong Polytechnic UniversityThe Hong Kong Polytechnic UniversityThe Hong Kong Polytechnic UniversityPorcine strains of livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA) have been recognized in many countries and have been shown to be able to cause human infection. Resistance to non-beta lactam antibiotics has been reported but non-susceptibility to vancomycin, which is known to occur in human MRSA, has so far not been observed in LA-MRSA. Such resistance is typically fairly low level involving changes in the cell wall thickness. The development of resistance is usually preceded by presence of a sub-population having an increased MIC, which is selected for by exposure to vancomycin. This study investigated vancomycin susceptibility of one hundred porcine MRSA isolates using three MIC methods including spiral gradient endpoint (SGE) technique which allows visualization of more resistant sub-populations. SGE revealed 16 strains with an MIC above 2.0 mg/L, of which 14 were determined to have MIC 4 mg/L by agar dilution. SGE revealed a further two isolates with MIC 2 mg/L. In addition, trailing endpoints not reaching resistance were present in 26 isolates with MIC 1.5 mg/L, the presence of vancomycin non-susceptibility in porcine isolates is of concern and further monitoring of LA-MRSA is essential.http://journal.frontiersin.org/Journal/10.3389/fmicb.2013.00316/fullVancomycinLivestock-associated MRSAVraSGraRSpiral gradient endpoint techniqueVRSA |
| spellingShingle | Gabriella Mei Lan Kwok Margaret May O'Donoghue Vijaya Chandranna Doddangoudar Jeff eHo Maureen Valerie Boost Reduced vancomycin susceptibility in porcine ST9 MRSA isolates Frontiers in Microbiology Vancomycin Livestock-associated MRSA VraS GraR Spiral gradient endpoint technique VRSA |
| title | Reduced vancomycin susceptibility in porcine ST9 MRSA isolates |
| title_full | Reduced vancomycin susceptibility in porcine ST9 MRSA isolates |
| title_fullStr | Reduced vancomycin susceptibility in porcine ST9 MRSA isolates |
| title_full_unstemmed | Reduced vancomycin susceptibility in porcine ST9 MRSA isolates |
| title_short | Reduced vancomycin susceptibility in porcine ST9 MRSA isolates |
| title_sort | reduced vancomycin susceptibility in porcine st9 mrsa isolates |
| topic | Vancomycin Livestock-associated MRSA VraS GraR Spiral gradient endpoint technique VRSA |
| url | http://journal.frontiersin.org/Journal/10.3389/fmicb.2013.00316/full |
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