Inanimate Surfaces and Air Contamination with Multidrug Resistant Species of Staphylococcus in the Neonatal Intensive Care Unit Environment.

BACKGROUND: Contamination of the hospital environment with multi-resistant (MDR) Staphylococcus increases the risk of infection. The aim of this study is to identify the MDR species of Staphylococcus on inanimate surfaces, in air, and in clinical samples, and analyze the risk factors that correlate with the occurrence of infections in a Neonatal Intensive Care Unit. METHODS: Samples of inanimate surfaces and air were taken using a premoistened swab (0.9% sodium chloride) and spontaneous air sedimentation, respectively. The clinical isolates were recovered from infected neonates. The isolates (environmental and clinical) were identified by matrix-assisted laser desorption ionization-time of flight and the resistance profile was calculated using the disk diffusion agar technique. RESULTS: In total, 181 isolates were obtained, 93 from (surfaces), 18 from the air, and 70 clinical samples. S. epidermidis was the most frequent species (66.8%), and the failure rate in air cleaning was 100%. More than 60% of the isolates were MDR, and the majority of clinical isolates (60.4%) had a resistance profile identical to that of the environmental isolates. CONCLUSION: Staphylococcus spp. were found in most of the analyzed samples, with a high frequency of MDR isolates, demonstrating the importance of the hospital environment as a reservoir, and the need for infection control measures, and rational use of antimicrobials.

Candidemia by Candida parapsilosis in a neonatal intensive care unit: human and environmental reservoirs, virulence factors, and antifungal susceptibility.

The Candida parapsilosis complex has emerged as one of the main causes of candidemia worldwide. This study aims to evaluate possible C. parapsilosis sensu stricto reservoirs in a NICU, the expression of virulence factors, and antifungal susceptibility, and to analyze their genetic and phenotypic similarity. The study included 17 isolates of C. parapsilosis: seven environmental, one from a newborn's mother, and nine samples from six newborns. We used molecular and phenotypic tests to characterize the isolates and to trace possible routes of infection. The genetic similarity was determined by random amplified polymorphic DNA. The hemolytic and DNAse activity was determined using sheep's blood and DNAse agar, biofilm production by XTT method, and the susceptibility to antifungals through microdilution methodology. Two environmental strains isolated in the same month had high similarity. The 17 isolates expressed at least one of the three virulence factors studied, and one environmental isolate was resistant to fluconazole. This study shows that environmental contamination can be an important reservoir of potentially pathogenic microorganisms, since isolates of C. parapsilosis sensu stricto collected from the hospital environment were able to express virulence factors. Therefore, we emphasized the importance of determining the transmission routes in NICU in order to detect pathogen sources and reservoirs, as well as to establish prevention measures, such as adequate disinfection of the environment.