Colonization of Residents and Staff of an Italian Long-Term Care Facility and an Adjacent Acute Care Hospital Geriatrics Unit by Multidrug-Resistant Bacteria.

In 2022, we undertook a point prevalence screening study for Enterobacterales with extended-spectrum ß-lactamases (ESBLs), high-level AmpC cephalosporinases and carbapenemases, and also methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) in a long-term care facility (LTCF) and the associated acute-care hospital Geriatrics unit in Bolzano, Northern Italy. Urine samples and rectal, inguinal, oropharyngeal, and nasal swabs were plated on selective agar plates. Metadata of the patients, including demographic data, were collected, and risk factors for colonization were determined. ESBL, AmpC, carbapenemase, and quinolone resistance genes were investigated by the HybriSpot 12 PCR AUTO System. The following colonization percentages by multidrug-resistant (MDR) bacteria have been found in LTCF residents: all MDR organisms, 59.5%; ESBL producers, 46.0% (mainly CTX-M-type enzymes); carbapenemase producers, 1.1% (one Klebsiella pneumoniae with KPC-type); MRSA, 4.5%; VRE, 6.7%. Colonization by MDR bacteria was 18.9% for LTCF staff and 45.0% for Geriatrics unit patients. Peripheral vascular disease, the presence of any medical device, cancer, and a Katz Index of 0 were significant risk factors for colonization of LTCF residents by MDR bacteria in univariate and/or multivariate regression analysis. To conclude, the ongoing widespread diffusion of MDR bacteria in the LTCF suggests that efforts should be strengthened on MDR screening, implementation of infection control strategies, and antibiotic stewardship programs targeting the unique aspects of LTCFs. ClinicalTrials.gov ID: 0530250-BZ Reg01 30/08/2022.

Staphylococcus epidermidis in feedings and feces of preterm neonates.

Staphylococcus epidermidis has emerged as the leading agent causing neonatal late-onset sepsis in preterm neonates; although the severity of the episodes caused by this species is often underestimated, it might exert relevant short- and long-term detrimental effects on neonatal outcomes. In this context, the objective of this study was to characterize a collection of S. epidermidis strains obtained from meconium and feces of preterm infants, and to assess the potential role of the enteral feeding tubes as potential reservoirs for this microorganism. A total of 26 preterm infants were enrolled in the study. Meconium and fecal samples were collected weekly during their first month of life (n = 92). Feeding samples were collected after their pass through the enteral feeding tubes (n = 84). S. epidermidis was present in the fecal samples of all the infants in, at least, one sampling time at concentrations ranging from 6.5 to 7.8 log10 CFU/g. Initially, 344 isolates were obtained and pulsed-field gel electrophoresis (PFGE) profiling allowed the reduction of the collection to 101 strains. Among them, multilocus sequence typing (MLST) profiling showed the presence of 32 different sequence types (ST). Globally, most of the STs to hospital-adapted high-risk clones and belonged to clonal complexes (CC) associated to the hospital environment, such as CC2. The virulence gene most commonly detected among the strains was altE. High resistance rates to macrolides and aminoglycosides were detected and 64% of the strains harboured the mecA gene, which was codified in SCCmec types. Our results indicates the existence of a complex and genetically diverse S. epidermidis population in the NICU environment. A better knowledge of S. epidermidis strains may help to devise strategies to avoid their conversion from symbiont to pathobiont microorganisms in the NICUs.

Serratia marcescens colonization in preterm neonates during their neonatal intensive care unit stay.

Background: Nosocomial sepsis is the main problem that preterms have to face during their stay at neonatal intensive care units (NICU). Serratia marcescens is an emerging cause of preterm sepsis but its epidemiology is still largely unknown. Consequently, the aims of this study were to know the rate of preterms colonized by S. marcescens during their stay at the NICU and the characteristics and evolution of the S. marcescens population, including the susceptibility to clinically relevant antibiotics. Methods: Twenty-six preterm infants born with a gestational age ≤ 32 weeks and/or weigh ≤1500 g were included in the study. Samples of meconium and feces (n = 92) were collected during their first month of life of the infants, together with feeding samples after their pass through enteral feeding tubes (n = 37). Samples were inoculated on MacConkey agar plates. The isolates identified as S. marcescens were genotyped using RAPD and PFGE; and antibiotics susceptibility was performed in a Vitek 2 system. Results: A total of 179 S. marcescens isolates were obtained from the samples. PFGE profiling and cluster analysis allowed the classification of the isolates into 7 different S. marcescens clones. PFGE patterns 1 and 3 were the dominant strains in the fecal samples colonizing 31 and 35% of the infants, respectively. Those isolates causing bacteremia in two infants clustered in PFGE pattern 3. Conclusion: S. marcescens is a bacterial species closely associated to the NICU environment. It can be frequently isolated from preterm's feces although only some genetic lineages seem to be associated to sepsis. Enteral feeding tubes act as important reservoirs to keep the S. marcescens population in the NICU. Trial registration: The local ethic committee approved this trial with the reference 09/157.