Zoccola Roberto, Di Blasio Alessia, Bossotto Tiziana, Pontei Angela, Angelillo Maria, Dondo Alessandro, Goria Maria, Zoppi Simona
Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, 10154 Torino, Italy.
Azienda Sanitaria Locale TO3 S.C. Sanità Animale, Pinerolo, 10064 Torino, Italy.
Microorganisms. 2021 May 11;9(5):1031. doi: 10.3390/microorganisms9051031.
is an emerging pathogen associated with endocarditis and vasculitis following cardiac surgery. Although it can take up to 6-8 weeks to culture on selective solid media, culture-based detection remains the gold standard for diagnosis, so more rapid methods are urgently needed. For the present study, we processed environmental infected simulates at volumes defined in international guidelines. Each preparation underwent real-time PCR; inoculates were placed in a VersaTREK™ automated microbial detection system and onto selective Middlebrook 7H11 agar plates. The validation tests showed that real-time PCR detected DNA up to a concentration of 10 ng/µL. A comparison of the isolation tests showed that the PCR method detected DNA in a dilution of ×10 CFU/mL in the bacterial suspensions, whereas the limit of detection in the VersaTREK™ was <10 CFU/mL. Within less than 3 days, the VersaTREK™ detected an initial bacterial load of 100 CFU. The detection limit did not seem to be influenced by NaOH decontamination or the initial water sample volume; analytical sensitivity was 1.5 × 10 CFU/mL; positivity was determined in under 15 days. VersaTREK™ can expedite mycobacterial growth in a culture. When combined with PCR, it can increase the overall recovery of mycobacteria in environmental samples, making it potentially applicable for microbial control in the hospital setting and also in environments with low levels of contamination by viable mycobacteria.
是一种与心脏手术后的心内膜炎和血管炎相关的新兴病原体。尽管在选择性固体培养基上培养可能需要长达6 - 8周,但基于培养的检测仍然是诊断的金标准,因此迫切需要更快速的方法。在本研究中,我们按照国际指南规定的体积处理环境感染模拟物。每种制剂都进行了实时PCR;接种物被放置在VersaTREK™自动微生物检测系统中,并接种到选择性Middlebrook 7H11琼脂平板上。验证试验表明,实时PCR可检测到浓度高达10 ng/µL的DNA。分离试验的比较表明,PCR方法在细菌悬液中能检测到×10 CFU/mL稀释液中的DNA,而VersaTREK™的检测限<10 CFU/mL。在不到3天的时间内,VersaTREK™检测到初始细菌载量为100 CFU。检测限似乎不受NaOH去污或初始水样体积的影响;分析灵敏度为1.5×10 CFU/mL;在15天内确定阳性。VersaTREK™可以加快培养中分枝杆菌的生长。当与PCR结合时,它可以提高环境样品中分枝杆菌的总体回收率,使其有可能应用于医院环境以及活菌分枝杆菌污染水平较低的环境中的微生物控制。