カルバペネムに耐性のある非典型性尿病原菌エシェリキア・コライのクローンの出現が,尿路感染症の増加の原因となっている
Lachlan L Walker1,2, Minh-Duy Phan1,2, Budi Permana1,2
1Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.
Nature communications
|September 2, 2025
まとめ
特定の大腸菌株 (ST167) が,尿路感染症 (UTI) を増加させている. この株,特にC2サブクラードは,有意な耐性遺伝子を携えており,クローン拡張を示しており,公衆衛生上の懸念が高まっています.
科学分野:
- 微生物学
- ゲノミクス
- 感染症
背景:
- カーバペネム耐性腸菌は 世界的に深刻な健康上の脅威です
- 尿路感染症 (UTI) を引き起こす尿病原性大腸菌 (UPEC) は,抵抗性が高まっている.
- フィルグループAのE. coli配列型167 (ST167) は,UTIの症例で上昇信号を示しています.
研究 の 目的:
- 尿路感染症に関与するE. coli ST167のゲノム特性と進化軌道を調査する.
- 抗菌剤耐性および毒性に関連したST167内の特定のクラードとサブクラードを特定する.
主な方法:
- UTIに関連するE. coli ST167のEnteroBaseデータセットの分析
- 全ゲノムシーケンシングと系統遺伝分析により,ST167のクラードとサブクラードが定義される.
- コアゲノムマルチロカスシーケンスのタイプ化 (cgMLST)
- 毒性因子と抗菌剤耐性遺伝子の調査
- 膀のコロニー化能力を評価するネズミのUTIモデル
主要な成果:
- 系統遺伝学的分析により,ST167内の3つの主要なクラード (A,B,C) が明らかになり,サブクラードC2はカルバペネムおよびセファロスポリン耐性遺伝子の高輸送を示した.
- サブクラードC2の株は,高いゲノム類似性 (コア遺伝子2,513のアレル差異<20) を表し,クレブシエラ由来カプセル型 (KL124,KL30) を抱えていた.
- 主に北米で見られるサブクラードC2は,2016年以降のクローン拡大の証拠を示している.
- タイプ1のフィムブリア遺伝子の喪失は,クラードBとCで観察された.
- 2つのサブクラードC2単離体は,ネズミのUTIモデルで膀のコロニー化が減少したことを示した.
結論:
- E. coli ST167は,特にサブクラードC2は,UTIに関連した非典型のUPECクローンを表しています.
- ST167サブクラードC2における抵抗性遺伝子の存在,クローン拡張,および変化した毒性の要因は,その新興の脅威の可能性を強調しています.
- 耐性UPEC菌株の拡散を理解し,それと闘うために,さらなる監視と研究が必要である.
関連する概念動画
01:25Urinary Tract Infection II: Pathophysiology
43
The pathophysiology of urinary tract infections (UTIs) encompasses several progressive stages, beginning with bacterial colonization and culminating in potential systemic complications if untreated. UTIs are primarily initiated by bacteria, such as Escherichia coli, which often originate from the gastrointestinal tract and migrate to the urinary system through the periurethral area. This migration can occur via several routes, including improper hygiene practices, sexual activity, or...
43
01:26Urinary Tract Infection I: Introduction
47
Urinary tract infections (UTIs) impact various parts of the urinary system, including the kidneys, ureters, bladder, and urethra. These infections are generally bacterial, with Escherichia coli being the most common causative agent, often originating from the gastrointestinal tract. However, other bacteria, such as Staphylococcus saprophyticus, Klebsiella pneumoniae, and Proteus mirabilis, are also known to cause UTIs. The type, location, and underlying complexity of the UTI guide both...
47
01:30Urinary Tract Infection III: Diagnostic Studies and Interprofessional Care
35
A healthcare provider can diagnose a urinary tract infection (UTI) through several methods:Medical History and Symptoms: The provider will take a detailed medical history and ask about symptoms such as frequent urination, burning sensation during urination, and lower abdominal pain.Urinalysis: A clean-catch urine sample is collected in a sterile container and tested for the presence of bacteria, white blood cells (leukocytes), nitrites, blood, and protein. The presence of leukocytes and...
35
01:26Urine Studies II: Urine Culture and Sensitivity Test
112
A urine culture and sensitivity test is a diagnostic procedure used to identify urinary tract bacterial infections and determine the most effective antibiotics for treatment. This test is generally preferred when a patient shows manifestations of a urinary tract infection, such as frequent or painful urination, cloudy or foul-smelling urine, or lower abdominal pain.Purpose of the TestThe primary goals of a urine culture and sensitivity test are to:Determine the specific bacteria causing the...
112
01:27Acute Pyelonephritis I: Introduction
44
Pyelonephritis is a bacterial infection that primarily affects the renal parenchyma and collecting system, including the renal pelvis, tubules, and interstitial tissue of one or both kidneys. It can be classified as either acute—a sudden, severe infection—or chronic, which refers to long-term or recurrent kidney infections.The primary cause of acute pyelonephritis (APN) is bacterial infection, with Escherichia coli accounting for approximately 70-80% of cases. Other bacteria, such...
44
01:17Urinary Tract Infection IV: Nursing Management
87
In managing urinary tract infections (UTIs) in nursing, a comprehensive assessment is essential. Begin by gathering subjective data, such as the patient’s complaints of dysuria (painful urination), urinary frequency, urgency, suprapubic pain, and any lower abdominal discomfort. This information can be complemented by questions regarding previous UTIs, sexual activity, and personal hygiene practices, which can provide insight into risk factors. Objective assessment should focus on signs...
87