19Healthcare-associated infections (HAI) are an important public health threat with the 20 multidrug-resistant (MDR) gram-negative bacteria (GNB) being of particular concern. Here 21 we present the antimicrobial resistance profile of HAI-related GNB (HAIrB) isolated from 22 patients (PT), healthcare workers (HCW) and hospital environment (HE) in a six-month 23 screening program. From the 180 sampling points distributed in six hospital units, a total of 24 1,080 swabs were collected allowing the isolation of 390 HAIrB: 50.5% from HE, 42.6% 25 2 from PT and 6.9% from HCW. Among the HAIrB, 32.6% were characterized as MDR and 26 38.7% as extended-spectrum cephalosporins resistant (ESC-R), showing no differences in the 27 distribution between PT, HE and HCW. Carbapenem resistance (CARB-R) was detected for 28 17.7% of all HAIrB, being higher among Acinetobacter spp. isolates (36.5%), followed by 29 Enterobacteriaceae (14.5%) and Pseudomonas spp. (11.8%). Except for the ICU, that 30 revealed higher MDR, CARB-R and ESC-R rates, HAIrB-resistant profiles were similarly 31 detected within the hospital units. Prevalence of bla KPC-like and bla CTX-M-1 β-lactamases-32 resistance genes was higher in K. pneumoniae and E. cloacae complex, while bla OXA-23-like 33 and bla SPM-like were higher in A. baumannii and P. aeruginosa, respectively. This study 34 reveals that the spreading of HAIrB within a hospital environment is higher than predicted, 35indicating that healthcare workers, hospital areas and equipment are key players on 36 dissemination of MDR gram-negative bacteria and shows that an active surveillance program 37 can provide precise understanding and direct actions towards control of HAI. 38 39 3 14). In this scenario, adoption of surveillance programs based on new technologies associated 51 with the rational management of antimicrobials and the continuous training for healthcare 52 workers can allow an effective control of HAI transmission, ensuring the patient safety and a 53 consequent reduction of direct and indirect healthcare costs (5,(15)(16). 54To better understand the antimicrobial resistance profile and the dissemination of HAI-related 55 GNB in the healthcare setting we carried out a six-month surveillance program targeting 56 patients, hospital environment and healthcare workers. 57 58
Material and Methods 59
Study design 60The Healthcare-associated Infections Microbiome Project (HAIMP) was carried out at the 61 Professor Polydoro Ernani