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Martina Spaziante,1 Carolina Venditti,2 Ornella Butera,2 Francesco Messina,2 Antonino Di Caro,2 Gilda Tonziello,1 Simone Lanini,1 Maria Adriana Cataldo,1 Vincenzo Puro1 1Emerging Infection Unit and Regional Service for Surveillance and Control of Infectious Diseases (SeRESMI), National Institute for Infectious Diseases “Lazzaro Spallanzani” IRCCS, Rome, Italy; 2Laboratory of Microbiology, National Institute for Infectious Diseases “Lazzaro Spallanzani” IRCCS, Rome, ItalyCorrespondence: Maria Adriana Cataldo Tel +39 0655170786Email adriana.cataldo@inmi.itIntroduction: New Delhi metallo-β-lactamase producing Klebsiella pneumoniae (NDM-Kpn) strains have been causing healthcare-associated infections worldwide. The aim of this study was to describe the molecular mechanisms of antimicrobial resistance and to analyze the clonality of NDM-Kpn isolates collected between January 2019 and June 2020 from patients admitted to hospitals from the Lazio region, Italy.Methods: We performed a retrospective cohort study. Whole-genome sequencing (WGS) was performed on all NDM-Kpn strains; clonality and genetic relationships were further investigated.Results: During the surveillance period, 17 NDM-Kpn isolates were obtained from 17 patients admitted to seven different hospitals. Eight different sequence types (STs) were detected: ST147 (n = 4), ST383 (n = 4), ST15 (n = 3), ST11 (n = 2), ST17 (n = 1), ST29 (n = 1), ST307 (n = 1) and the newly identified ST4853 (n = 1). Genetic relationships were further investigated by the WGS-based core genome MLST (cgMLST) scheme, and 5 cluster types (CTs) were identified. Whereas a substantial overall heterogeneity among isolates was detected (8 different STs were identified out of 17 isolates), the strains within each cluster showed a very high level of genome similarity.Discussion: Our study highlights the key role of surveillance, which allowed taking a picture of a part of the NDM-Kpn strains circulating in Italy, adding further insight into their molecular features.Keywords: carbapenem-resistant Klebsiella pneumoniae, New Delhi metallo-β-lactamase, surveillance, healthcare-associated infections

A Cannas,1 O Butera,1 G Gualano,2 MP Parracino,3 C Venditti,1 A Mazzarelli,1 F Palmieri,2 E Girardi,3,* A Di Caro1,* 1Microbiology and Bio-Repository Unit, National Institute for Infectious Diseases “L. Spallanzani” IRCCS, Rome, Italy; 2Respiratory Infectious Diseases Unit, National Institute for Infectious Diseases “L. Spallanzani” IRCCS, Rome, Italy; 3Clinical Epidemiology Unit, National Institute for Infectious Diseases “L. Spallanzani” IRCCS, Rome, Italy*These authors contributed equally to this workCorrespondence: A CannasNational Institute for Infectious Diseases “L. Spallanzani” IRCCS, Via Portuense 292, Rome 00149, ItalyTel +39 06 5517 0905Email angela.cannas@inmi.itPurpose: Multidrug-resistant tuberculosis (MDR-TB) is a major burden to public health in low incidence countries in Europe. The aim of this study was to attempt to have a better insight into the trends of MDR-TB in the metropolitan area of Rome, within the Italian and the foreign-born population, based on microbiological and demographic data.Patients and methods: We performed a prospective study, collecting microbiological data based on phenotypic drug-resistant testing (DST) of TB strains consecutively isolated in a referral hospital in Rome, the capital city of a low TB incidence country, over a 6-year period, and correlated them to the geographical origin of patients. This study was carried out in a referral hospital for patients with drug-resistant TB from the whole region.Results: Drug-resistance data from 926 patients with a microbiological diagnosis of TB from 2011 to 2016 show a 5.5% rate of MDR-TB, mostly occurring in patients born in a single East European country, that has a high incidence of MDR-TB. The strains isolated from these patients frequently carry additional resistances, leading to an increased risk of developing extensively drug-resistant (XDR) TB.Conclusion: In the great metropolitan area of Rome, MDR-TB more frequently occurs in patients who were born in a single country from Eastern Europe known to have high rates of MDR-TB and long-time residents in Italy. Recent immigrants from non-European countries do not appear to contribute to the rates of MDR-TB reported in this article. This knowledge of local TB trends could help improve the measures of surveillance and prevention of disease.Keywords: tuberculosis, drug-susceptibility testing, MDR-TB, XDR-TB