Laura Alksne, Svetlana Makarova, Jeļena Avsejenko, Alla Cibrovska, Julija Trofimova, Olga Valciņa
{"title":"MALDI-TOF MS法测定拉脱维亚临床分离株中耐甲氧西林金黄色葡萄球菌和表皮葡萄球菌。","authors":"Laura Alksne, Svetlana Makarova, Jeļena Avsejenko, Alla Cibrovska, Julija Trofimova, Olga Valciņa","doi":"10.1016/j.clinms.2020.03.001","DOIUrl":null,"url":null,"abstract":"<div><p>Rapid identification of methicillin-resistant <em>Staphylococcus</em> could ensure appropriate medical care. A total of 409 <em>Staphylococcus</em> spp. strains were used to develop a reliable MALDI-TOF method for species identification. We tested twelve <em>S. aureus</em> strains to compare three different sample preparation methods and the reproducibility of the methicillin-resistant <em>m</em>/<em>z</em> 2414 ± 2 indicator peak with direct method in triplicate. A total of 65 <em>Staphylococcus</em> spp. strains (including 37 methicillin-resistant strains) from clinical and hospital environment isolates were used to confirm the presence of phenol-soluble modulin (PSM-mec) peptide. All 272 <em>S. aureus</em> strains from 409 samples were correctly identified at species level by MALDI-TOF. The samples prepared by three methods gave spectra with differences in the intensities and presence of certain peaks. The PSM-mec peak was not visible after the extraction method. The peak <em>m</em>/<em>z</em> 2414 ± 2 was only detected in 61% of the methicillin-resistant strains and in none of the methicillin-sensitive strains. The peak reproducibility for the five analyzed <em>S. aureus</em> strains showing the peak at <em>m</em>/<em>z</em> 2414 ± 2 was 87%. The delta-toxin was observed in 49 out of 65 samples regardless of methicillin susceptibility, as well as in all the samples exhibiting the PSM-mec peak. The peak <em>m</em>/<em>z</em> 2414 ± 2 is specific to methicillin-resistant strains carrying the <em>mecA</em> gene, but the absence of peak <em>m</em>/<em>z</em> 2414 ± 2 does not exclude the possibility of resistance to methicillin. Thus, implementing MALDI-TOF analysis in routine laboratory work, especially with clinical samples, would in many cases provide rapid warning about the presence of methicillin-resistant strains.</p></div>","PeriodicalId":72613,"journal":{"name":"","volume":"16 ","pages":"Pages 33-39"},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.clinms.2020.03.001","citationCount":"6","resultStr":"{\"title\":\"Determination of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis by MALDI-TOF MS in clinical isolates from Latvia\",\"authors\":\"Laura Alksne, Svetlana Makarova, Jeļena Avsejenko, Alla Cibrovska, Julija Trofimova, Olga Valciņa\",\"doi\":\"10.1016/j.clinms.2020.03.001\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Rapid identification of methicillin-resistant <em>Staphylococcus</em> could ensure appropriate medical care. A total of 409 <em>Staphylococcus</em> spp. strains were used to develop a reliable MALDI-TOF method for species identification. We tested twelve <em>S. aureus</em> strains to compare three different sample preparation methods and the reproducibility of the methicillin-resistant <em>m</em>/<em>z</em> 2414 ± 2 indicator peak with direct method in triplicate. A total of 65 <em>Staphylococcus</em> spp. strains (including 37 methicillin-resistant strains) from clinical and hospital environment isolates were used to confirm the presence of phenol-soluble modulin (PSM-mec) peptide. All 272 <em>S. aureus</em> strains from 409 samples were correctly identified at species level by MALDI-TOF. The samples prepared by three methods gave spectra with differences in the intensities and presence of certain peaks. The PSM-mec peak was not visible after the extraction method. The peak <em>m</em>/<em>z</em> 2414 ± 2 was only detected in 61% of the methicillin-resistant strains and in none of the methicillin-sensitive strains. The peak reproducibility for the five analyzed <em>S. aureus</em> strains showing the peak at <em>m</em>/<em>z</em> 2414 ± 2 was 87%. The delta-toxin was observed in 49 out of 65 samples regardless of methicillin susceptibility, as well as in all the samples exhibiting the PSM-mec peak. The peak <em>m</em>/<em>z</em> 2414 ± 2 is specific to methicillin-resistant strains carrying the <em>mecA</em> gene, but the absence of peak <em>m</em>/<em>z</em> 2414 ± 2 does not exclude the possibility of resistance to methicillin. Thus, implementing MALDI-TOF analysis in routine laboratory work, especially with clinical samples, would in many cases provide rapid warning about the presence of methicillin-resistant strains.</p></div>\",\"PeriodicalId\":72613,\"journal\":{\"name\":\"\",\"volume\":\"16 \",\"pages\":\"Pages 33-39\"},\"PeriodicalIF\":0.0,\"publicationDate\":\"2020-04-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.clinms.2020.03.001\",\"citationCount\":\"6\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2376999820300064\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2376999820300064","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Determination of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis by MALDI-TOF MS in clinical isolates from Latvia
Rapid identification of methicillin-resistant Staphylococcus could ensure appropriate medical care. A total of 409 Staphylococcus spp. strains were used to develop a reliable MALDI-TOF method for species identification. We tested twelve S. aureus strains to compare three different sample preparation methods and the reproducibility of the methicillin-resistant m/z 2414 ± 2 indicator peak with direct method in triplicate. A total of 65 Staphylococcus spp. strains (including 37 methicillin-resistant strains) from clinical and hospital environment isolates were used to confirm the presence of phenol-soluble modulin (PSM-mec) peptide. All 272 S. aureus strains from 409 samples were correctly identified at species level by MALDI-TOF. The samples prepared by three methods gave spectra with differences in the intensities and presence of certain peaks. The PSM-mec peak was not visible after the extraction method. The peak m/z 2414 ± 2 was only detected in 61% of the methicillin-resistant strains and in none of the methicillin-sensitive strains. The peak reproducibility for the five analyzed S. aureus strains showing the peak at m/z 2414 ± 2 was 87%. The delta-toxin was observed in 49 out of 65 samples regardless of methicillin susceptibility, as well as in all the samples exhibiting the PSM-mec peak. The peak m/z 2414 ± 2 is specific to methicillin-resistant strains carrying the mecA gene, but the absence of peak m/z 2414 ± 2 does not exclude the possibility of resistance to methicillin. Thus, implementing MALDI-TOF analysis in routine laboratory work, especially with clinical samples, would in many cases provide rapid warning about the presence of methicillin-resistant strains.