Number of isolates with ESBL-producing gene.

The spread of antimicrobial-resistant bacteria is a global threat. Our previous study investigated oral colonization by Gram-negative antimicrobial-resistant bacteria and methicillin-resistant Staphylococcus aureus (MRSA) in long-term care facilities. In this study, antimicrobial-resistant bacteria in the oral cavity of bedridden severely dependent elderly residents were investigated and the relationship of antimicrobial-resistant bacteria with oral and systemic status was clarified. In addition, the effect of professional oral care on antimicrobial-resistant bacteria colonization was investigated. This was a cross-sectional study followed by an interventional study. Fifty-seven residents were randomly assigned to screening for the presence of Gram-negative antimicrobial-resistant bacteria with 3rd-generation cephalosporin or carbapenem-resistance methods and the presence of oral and rectal MRSA using respective selective plates. Epidemiological data were collected from clinical records. The interventional study was conducted on 23 subjects who presented with Gram-negative antimicrobial-resistant bacteria or S. aureus in the cross-sectional study. The interventions included professional oral care once a week for 8 weeks in addition to daily oral care. Antimicrobial-resistant bacteria colonization before and after the intervention was compared. Among 57 subjects, antimicrobial-resistant bacteria were isolated from oral samples of 29 subjects and from rectal samples of 44 subjects. Among 29 subjects with oral antimicrobial-resistant bacteria, Gram-negative antimicrobial-resistant bacteria and MRSA were isolated from 21 and 17 subjects, respectively. Logistic regression analysis of the independent variables revealed that Non-oral nutritional intake was significantly related to Gram-negative antimicrobial-resistant bacteria positivity. In the interventional study, professional oral care failed to eliminate of oral antimicrobial-resistant bacteria in most subjects. This study showed that subjects with Non-oral nutritional intake had significantly higher rates of oral Gram-negative antimicrobial-resistant bacteria. These findings concluded that a short-term professional oral management has a limited capacity to eliminate antimicrobial-resistant bacteria. Our results provide important information for the control of infections caused by antimicrobial-resistant bacteria in the oral cavity.

耐抗菌药物细菌（antimicrobial-resistant bacteria）的传播已成为全球性公共卫生威胁。我们此前的研究针对长期照护机构内的革兰氏阴性耐药菌与耐甲氧西林金黄色葡萄球菌（methicillin-resistant Staphylococcus aureus, MRSA）的口腔定植情况展开了调查。本研究聚焦重度失能卧床老年居住者的口腔耐药菌定植状况，明确了耐药菌与口腔及全身健康状态的关联；同时探究了专业口腔护理对耐药菌口腔定植的干预效果。本研究采用横断面研究（cross-sectional study）联合干预性研究（interventional study）的设计方案：共纳入57名受试者，受试者被随机分配接受两项筛查，一是采用第三代头孢菌素（3rd-generation cephalosporin）或碳青霉烯类耐药（carbapenem-resistance）检测方法筛查革兰氏阴性耐药菌，二是通过专用选择性培养基（selective plates）筛查口腔与直肠样本中的MRSA定植情况，研究的流行病学数据均来源于临床病历记录。针对横断面研究中检出革兰氏阴性耐药菌或金黄色葡萄球菌的23名受试者，本研究开展了干预性研究：干预方案为在日常口腔护理基础上，每周实施1次专业口腔护理，持续8周，对比干预前后受试者的耐药菌定植状态。在全部57名受试者中，29名的口腔样本检出耐药菌，44名的直肠样本检出耐药菌；在29名口腔定植耐药菌的受试者中，分别有21名检出革兰氏阴性耐药菌、17名检出MRSA。对自变量开展的logistic回归分析（logistic regression analysis）显示，非经口营养摄入（Non-oral nutritional intake）与革兰氏阴性耐药菌阳性检出率显著相关。干预性研究结果显示，专业口腔护理未能使多数受试者的口腔耐药菌定植得到清除。本研究表明，非经口营养摄入者的口腔革兰氏阴性耐药菌检出率显著更高；短期专业口腔管理在清除耐药菌方面的能力较为有限。本研究结果为口腔耐药菌相关感染的防控工作提供了重要参考依据。