小森 敏明

感染症の診断・治療に臨床検査は必須である。特に感染症検査は病気の原因となる微生物の同定、治療薬の適正使用に有効な薬剤感受性検査結果を提供する。
我々は感染症検査システムにおいて、検体の受付基準の設定、検査方法や再検基準の統一化、薬剤感受性検査報告のカスケード報告や選択的報告の導入、報告コメントのフォーマット化に取り組んだ。その結果、正確で信頼性の高い検査データを報告するシステムが構築できた。本システムは感染症検査の標準化だけでなく、技師教育にも利用できる。今後は更なる精度の向上と新しい検査への対応を追加していく必要がある。

薬剤耐性菌による感染症は治療薬が限定されるだけでなく、患者の入院期間延長につながる。また、薬剤耐性菌が検出された施設では院内感染防止対策をとり、アウトブレイク発生の有無を調査する。検査室では薬剤感受性検査や遺伝子検査など数種類の検査を組み合わせて薬剤耐性菌のスクリーニング検査や確定検査を実施している。簡便で迅速、検査コストが安価な薬剤耐性菌検査法の開発が望まれる。

薬剤耐性菌は感染症患者のみならず、院内感染や地域での拡散が問題になる。我々は京滋薬剤耐性菌サーベイランス研究会を2001年から立ちあげ、京滋地域の十数施設で共同して統一の検出基準を作成し、薬剤耐性菌の分離状況を調査している。メチシリン耐性黄色ブドウ球菌（MRSA）やメタロ-β-ラクタマーゼ（MBLs）産生菌は経年的に減少してきたが、基質特異性拡張型β-ラクタマーゼ（ESBLs）産生菌は増加してきた。特定の施設では同一の遺伝子型を有する薬剤耐性菌が確認され、院内感染が疑われた。今後は世界保健機構（WHO）が示すヒト・動物・環境を一体として考える「one health」の概念に則り、抗菌薬の適正使用を考えていく必要がある。

Microbial testing is essential for the diagnosis and treatment of infectious diseases. Microbial testing provides the identification of causative microbe for the disease and the results of drug-sensitivity test that is effective for appropriate use of antimicrobial agents. In the infectious disease test system, we worked on establishing the acceptance criteria for samples, unification of test methods and the criteria for retesting, cascading and selective reporting of antimicrobial susceptibility reports, and formatting of report comments. As a result, we have developed a system that reports accurate and reliable test data. This system can be used not only for the standardization of infectious disease tests but also for the education of technicians. In the future, further improvement of the accuracy of tests and the adaptation to new tests should be added to the system.

Infection with antimicrobial resistant bacteria not only limits the treatments applicable but also prolongs patients’ hospitalization. In addition, the facilities where antimicrobial resistant bacteria are detected have to take measures to prevent nosocomial infections and examine the possible occurrence of outbreaks. The laboratory conducts screening and definitive tests of antimicrobial resistant bacteria by combining several types of tests such as antimicrobial susceptibility tests and genetic tests. It is desirable to develop a simple, fast, and inexpensive method for testing antimicrobial resistant bacteria.

Antimicrobial resistant bacteria are problematic with respect to hospital infection and the spread in communities in addition to be troubling for infected patients. We have been active in the Kyoto-Shiga Clinical Microbiology Study Group since 2001. Around a dozen of facilities in Kyoto and Shiga prefectures have developed unified standards in their joint effort, and are investigating the situation of detecting antimicrobial resistant bacteria. Methicillin-resistant Staphylococcus aureus (MRSA) and metallo β-lactamase-producing bacteria have decreased over time, while extended-spectrum β-lactamase-producing bacteria have increased. In particular facilities, antimicrobial resistant bacteria with the same genotype were identified, which is suggestive of nosocomial infections. In the future, we should consider the proper use of antibacterial agents in accordance with the concept of “one health”, a concept proposed by the World Health Organization (WHO), in which we consider human, animal and environment in an integrated manner.