Calderaro Adriana, Buttrini Mirko, Farina Benedetta, Montecchini Sara, Martinelli Monica, Arcangeletti Maria Cristina, Chezzi Carlo, De Conto Flora
Department of Medicine and Surgery, University of Parma, Viale A. Gramsci 14, 43126 Parma, Italy.
Unit of Clinical Virology, University Hospital of Parma, Viale A. Gramsci 14, 43126 Parma, Italy.
Microorganisms. 2022 Jul 21;10(7):1477. doi: 10.3390/microorganisms10071477.
The epidemiology of Clostridioides difficile infection (CDI) has changed over the last two decades, due to the emergence of C. difficile strains with clinical relevance and responsible for nosocomial outbreaks with severe outcomes. This study reports an outbreak occurred in a Long-term Care Unit from February to March 2022 and tracked by using a Matrix-Assisted Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) typing approach (T-MALDI); subsequently, a characterization of the toxigenic and antimicrobial susceptibility profiles of the C. difficile isolates was performed. A total of 143 faecal samples belonging to 112 patients was evaluated and C. difficile DNA was detected in 51 samples (46 patients). Twenty-nine C. difficile isolates were obtained, and three different clusters were revealed by T-MALDI. The most representative cluster accounted 22 strains and was considered to be epidemic, in agreement with PCR-Ribotyping. Such epidemic strains were susceptible to vancomycin (MIC ≤ 0.5 mg/mL) and metronidazole (MIC ≤ 1 mg/mL), but not to moxifloxacin (MIC > 32 mg/mL). Moreover, they produced only the Toxin A and, additionally, the binary toxin. To our knowledge, this is the first reported outbreak referable to a tcdA+/tcdB-/cdt+ genotypic profile. In light of these results, T-MALDI is a valid and rapid approach for discovering and tracking outbreaks.
在过去二十年中，艰难梭菌感染（CDI）的流行病学发生了变化，这是由于出现了具有临床相关性且导致严重后果的医院内暴发的艰难梭菌菌株。本研究报告了2022年2月至3月在一个长期护理病房发生的一次暴发，并采用基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）分型方法（T-MALDI）进行追踪；随后，对艰难梭菌分离株的产毒和抗菌药敏谱进行了表征。共评估了112例患者的143份粪便样本，在51份样本（46例患者）中检测到艰难梭菌DNA。获得了29株艰难梭菌分离株，T-MALDI显示出三个不同的簇。最具代表性的簇有22株菌株，与PCR核糖体分型一致，被认为是流行株。这些流行株对万古霉素（MIC≤0.5mg/mL）和甲硝唑（MIC≤1mg/mL）敏感，但对莫西沙星（MIC>32mg/mL）不敏感。此外，它们仅产生毒素A，另外还产生二元毒素。据我们所知，这是首次报告的与tcdA+/tcdB-/cdt+基因型谱相关的暴发。鉴于这些结果，T-MALDI是发现和追踪暴发的一种有效且快速的方法。
