Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden.
District Veterinarians, Swedish Board of Agriculture, Gothenburg, Sweden.
Equine Vet J. 2020 Nov;52(6):884-890. doi: 10.1111/evj.13248. Epub 2020 Mar 2.
Endoscopic examinations are essential for diagnosis and treatment of strangles (S equi infection) in horses. However, even after disinfection, endoscopes may retain viable bacteria or bacterial DNA. Twitches are commonly used during endoscopic examinations and can thus also potentially transmit the organism to other horses.
To evaluate the efficacy of different disinfectant methods to eliminate S equi from experimentally contaminated endoscopes and twitches and the effectiveness of field disinfection of endoscopes used in sampling carriers of S equi.
Experimental contamination and observational field study.
One endoscope and 30 twitches were contaminated with standardised S equi broth solutions. The endoscope was disinfected following three protocols using various disinfectants for manual disinfection. A fourth protocol used an automated endoscope reprocessor (AER). The twitches (n = 30) were disinfected following eight different disinfecting protocols. Three endoscopes used in sampling for silent carriers were disinfected following a field-based protocol. After each protocol the endoscopes and twitches were sampled for S equi by culture and qPCR.
Following experimental contamination all endoscope disinfection protocols, apart from 1/6 of the ethanol protocol were S equi culture negative. However, no endoscope disinfection protocol completely eliminated retention of S equi DNA. Field disinfection of endoscopes after sampling carriers yielded no culture positives and all but one (13/14) were qPCR negative. All twitches disinfected following experimental contamination were culture negative but sodium hypochlorite was the only disinfectant that completely eliminated detection of S equi DNA.
Experimental contamination may not reflect the numbers of S equi transferred to endoscopes or twitches during use on silent carriers and purulent secretions from infected horses may influence survival of S equi.
While most disinfection methods appear to ensure removal of cultivable S equi, residual DNA can remain on both endoscopes and twitches.
内窥镜检查对于马的缰腺炎（S 马流感感染）的诊断和治疗至关重要。然而，即使经过消毒，内窥镜仍可能保留有活力的细菌或细菌 DNA。在内窥镜检查过程中常使用搐搦，因此也可能将病原体传播给其他马匹。
评估不同消毒剂方法从实验污染的内窥镜和搐搦中消除 S 马流感的效果，以及对用于采样 S 马流感携带者的内窥镜进行现场消毒的效果。
实验污染和观察性现场研究。
用标准化的 S 马流感肉汤溶液污染 1 个内窥镜和 30 个搐搦。内窥镜使用三种不同的消毒剂进行手动消毒，根据三个方案进行消毒。第四个方案使用自动内窥镜处理器（AER）。30 个搐搦根据 8 种不同的消毒方案进行消毒。在基于现场的方案下，对用于采样无症状携带者的 3 个内窥镜进行消毒。在每个方案之后，通过培养和 qPCR 对内窥镜和搐搦进行 S 马流感采样。
除了 1/6 的乙醇方案外，所有内窥镜消毒方案在实验污染后均未培养出 S 马流感。然而，没有任何内窥镜消毒方案能完全消除 S 马流感 DNA 的保留。采样携带者后对内窥镜进行现场消毒未产生培养阳性，除 1 个外（13/14）qPCR 均为阴性。所有经实验污染后消毒的搐搦均为培养阴性，但次氯酸钠是唯一能完全消除 S 马流感 DNA 检测的消毒剂。
实验污染可能无法反映在无症状携带者和感染马的脓性分泌物上使用时转移到内窥镜或搐搦上的 S 马流感数量。
虽然大多数消毒方法似乎可以确保清除可培养的 S 马流感，但内窥镜和搐搦上仍可能残留 DNA。
