Whole genome sequencing of carbapenem-resistant Klebsiella pneumoniae: evolutionary analysis for outbreak investigation.

Aim: Carbapenemase-resistant Enterobacteriaceae represents a major concern in hospital setting. Materials & methods: The evolutionary history of carbapenem-resistant Klebsiella pneumonia strains was analyzed by core genome multilocus sequence typing and Bayesian phylogenesis by whole genomes sequencing. Results: A great increase carbapenem-resistant K.pneumoniae causing blood stream infection was observed in the years 2015-2016. At multilocus sequence typing (MLST), they were prevalently ST512 and ST101. ST512 were core genome (cg)MLST 53, while ST101 mainly cgMLST453. The minimum-spanning tree, based on cgMLST, showed strains clustering based on the different STs. By Bayesian phylogenetic analysis, maximum clade credibility tree showed that strains were introduced in the year 2005 with the most probable location in the ICU ward. Two outbreaks by ST101 and ST512 strains with Tower T8 as the probable location were evidenced. Conclusion: Molecular epidemiology is a powerful tool to track the way of transmission of resistant bacteria within the hospital setting.

Multicenter evaluation of the RAPIDEC® CARBA NP test for rapid screening of carbapenemase-producing Enterobacteriaceae and Gram-negative nonfermenters from clinical specimens.

The rapid diagnosis of carbapenemase-producing (CP) bacteria is essential for the management of therapy and infection control. In this study, RAPIDEC® CARBA NP (RCNP) was evaluated for the rapid screening of CP Enterobacteriaceae, Acinetobacter baumannii complex, and Pseudomonas aeruginosa from clinical specimens collected at five Italian hospitals. Firstly, each site tested 20 well-characterized strains in a blinded fashion. Secondly, each center prospectively tested 25 isolates from blood cultures processed with a rapid workflow (6h after subculture) and 25 isolates from other specimens processed after an overnight culture. The presence of carbapenemases was confirmed by multiplex real-timePCRs targeting carbapenemase genes. RCNP presented an overall sensitivity, specificity, positive predictive value, and negative predictive value of 70%, 94%, 82%, and 89%, respectively, with a higher performance in detection of CP Enterobacteriaceae and a poorer performance in detection of CP A. baumannii complex. With isolates from blood cultures, RCNP could significantly reduce the time required for identification of CP Enterobacteriaceae (less than 9h since the positivization of blood cultures).

Performance evaluation of Anyplex™II HPV28 detection kit in a routine diagnostic setting: comparison with the HPV Sign® Genotyping Test.

Anyplex™II HPV28 is a new PCR assay designed for HPV genotyping. It can detect 28 HPV types including 19 high-risk and 9 low-risk types. This study evaluated the performance of Anyplex™II HPV28 on 123 fresh cervical samples screened in parallel with HPV Sign® Genotyping Test. Of the 123 samples screened, 93 were positive, 15 negative, and 15 discordant. The total number of HPV positive samples combined was 108: 38 single infections and 70 multiple infections. The agreement between the two tests was 87.8%, κ=0.592. Genotype specific agreement was strong for HPV 16 (k=0.761), HPV 18 (k=0.674), and HPV 35 (k=0.796). Sensitivity and specificity of Anyplex™II HPV28 assay using HPV Sign® Genotyping Test as reference was 84.8% and 94%; conversely, sensitivity and specificity of HPV Sign® Genotyping Test was 29% and 99.5%. Anyplex™II HPV28 assay is a sensitive and specific assay suitable for HPV genotyping but requires clinical validation.