Paniagua-Contreras Gloria, Monroy-Pérez Eric, Gutiérrez-Lucas Raúl, Sainz-Espuñes Teresita, Bustos-Martínez Jaime, Vaca Sergio
FES-Iztacala, Universidad Nacional Autónoma de México (UNAM), Av. de Los Barrios 1, Los Reyes Iztacala, 54090, Tlalnepantla, Mexico.
Folia Microbiol (Praha). 2014 Jul;59(4):295-302. doi: 10.1007/s12223-013-0300-4. Epub 2014 Jan 15.
Methicillin-resistant Staphylococcus aureus (MRSA) is the causal agent of multiple nosocomial infections worldwide, including catheter-associated bacteremia in hemodialysis patients. The purposes of this work were to genetically characterize a group of MRSA isolates from catheter-related infections of ambulatory Mexican hemodialysis patients and to determine whether the strains are the same as those carried by the patients in their anterior nares. Sixteen pairs of MRSA isolates from the catheter (cat) and anterior nares (N) of hemodialysis patients were compared using pulsed-field gel electrophoresis (PFGE), PCR detection of adhesion genes and other virulence markers, and an antibiogram. Three pairs of N/cat MRSA isolates (18.7 %) with identical resistograms also showed the same combination of PCR-detected markers and PFGE pattern; one additional pair showed only an identical electrophoretic PFGE pattern. Of the MRSA isolates, 75 % (n = 24) were resistant to ≥ 7 antibiotics, 4 isolates were resistant to 11 antibiotics, and 7 isolates were resistant to the 12 antibiotics tested. The most frequent virulence marker combination found was spa, clfA, clfB, cna, bbp, ebps, map/eap, sdrC, sdrD, sdrE, ica, agr (65.6 %, n = 21). The SCCmec alleles of the 32 MRSA isolates were IV (n = 20), I (n = 7), II (n = 4), and V (n = 1), and no SCCmec type III MRSA was found. The genotypic characterization of the MRSA isolates studied in this work will contribute to a better understanding of the virulence gene makeup of catheter-colonizing S. aureus strains and will help to lower the infection risk in these patients.
耐甲氧西林金黄色葡萄球菌（MRSA）是全球多种医院感染的病原体，包括血液透析患者的导管相关菌血症。本研究的目的是对一组来自墨西哥非卧床血液透析患者导管相关感染的MRSA分离株进行基因特征分析，并确定这些菌株是否与患者前鼻孔中携带的菌株相同。使用脉冲场凝胶电泳（PFGE）、粘附基因和其他毒力标记物的PCR检测以及抗菌谱，比较了16对来自血液透析患者导管（cat）和前鼻孔（N）的MRSA分离株。三对具有相同耐药谱的N/cat MRSA分离株（18.7%）也显示出PCR检测标记物的相同组合和PFGE图谱；另外一对仅显示相同的PFGE电泳图谱。在MRSA分离株中，75%（n = 24）对≥7种抗生素耐药，4株对11种抗生素耐药，7株对所测试的12种抗生素耐药。最常见的毒力标记物组合是spa、clfA、clfB、cna、bbp、ebps、map/eap、sdrC、sdrD、sdrE、ica、agr（65.6%，n = 21）。32株MRSA分离株的SCCmec等位基因分别为IV型（n = 20）、I型（n = 7）、II型（n = 4）和V型（n = 1），未发现SCCmec III型MRSA。本研究中对MRSA分离株的基因特征分析将有助于更好地了解导管定植金黄色葡萄球菌菌株的毒力基因组成，并有助于降低这些患者的感染风险。
