Despite their significant impact on public health, antibiotic resistance and size distributions of airborne viable bacteria in indoor environments in neonatal intensive care units (NICU) remain understudied. Therefore, the objective of this study was to assess the antibiotic resistance of airborne viable bacteria for different sizes (0.65–7 µm) in private-style and public-style neonatal intensive care units (NICU). Airborne bacteria concentrations were assessed by a six-stage Andersen impactor, operating at 28.3 L/min. Public-style NICU revealed higher concentrations of airborne viable bacteria (53.00 to 214.37 CFU/m3) than private-style NICU (151.94–466.43), indicating a possible threat to health. In the public-style NICU, Staphylococcus was the highest bacterial genera identified in the present study, were Staphylococcus saprophyticus and Staphylococcus epidermidis predominated, especially in the second bronchi and alveoli size ranges. Alloiococcus otitidis, Bacillus subtiles, Bacillus thuringiensis, Kocuria rosea, and Pseudomonas pseudoalcaligene, were identified in the alveoli size range. In NICU#2, eight species were identified in the alveoli size range: Bacillus cereus, Bacillus subtilis, Bacillus thuringiensis, Eikenella corrodens, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus gordoni. Multi-drug-resistant organisms (MDROs) were found in both of the NICUs. Bacillus cereus strains were resistant to Ampicillin, Cefoxitin, Ceftaroline, and Penicillin G. Staphylococcus cohnii ssp. cohnii was resistant in parallel to ampicillin and G penicillin. Staphylococcus saprophyticus strains were resistant to Ampicillin, Penicillin G, Oxaxilin, and Erythromycin. Results may indicate a potential threat to human health due to the airborne bacteria concentration and their antibiotic resistance ability. The results may provide evidence for the need of interventions to reduce indoor airborne particle concentrations and their transfer to premature infants with underdeveloped immune systems, even though protocols for visitors and cleaning are well-established.

The object of this research to determine the statistical relationship and degree of association between variables: hospital admission days and diagnostic (disease) potentially associated to fungal bioaerosols exposure. Admissions included acute respiratory infections, atopic dermatitis, pharyngitis and otitis. Statistical analysis was done using Statgraphics Centurion XVI software. In addition, was estimated the occupational exposure to fungal aerosols in stages of a landfill using BIOGAVAL method and represented by Golden Surfer XVI program. Biological risk assessment with sentinel microorganism A. fumigatus and Penicillium sp, indicated that occupational exposure to fungal aerosols is Biological action level. Preventive measures should be taken to reduce the risk of acquiring acute respiratory infections, dermatitis or other skin infections.

Resumen-En este estudio se evaluaron la inmisión de los bioaerosoles bacterianos en las diferentes del sistema respiratorio en una unidad de cuidados intensivos neonatales (UCI). En este estudio, se utilizó un impactador Andersen de seis etapas para el muestreo de bioaerosoles con un caudal de 28,3 L/min. Las concentraciones obtenidas de bioaerosoles bacterianos oscilaron entre 67 y 423 UFC/m 3 , con un valor promedio de 110,13 UFC/m 3 , lo que puede representar una posible amenaza para la salud de los trabajadores y los neonatos en la UCI. Los resultados indicaron que Staphylococcus saprophyticus y Staphylococcus epidermidis habían predominado, especialmente en la quinta y sexta etapa, lo que significa segundos bronquios y alvéolos. Mientras que Staphylococcus fue el género de mayor prevalencia, Alloiococcus otitidis, Bacillus subtiles, Bacillus thuringiensis, Kocuria rosea y Pseudomonas pseudoalcaligene se presentaron en los alvéolos. Palabras Claves: calidad del aire; bioaerosoles; Unidad de cuidado intensivo neonatal; infecciones respiratorias; Resistencia a antibióticos; salud pública; Evaluación de riesgos.

In this study, the emmission of the Bacterial bioaerosols in the different respiratory system in a neonatal intensive care unit (ICU). In this study, a six-stage Andersen impactor was used for the sampling of bioaerosols with a flow rate of 28.3 L / min. The concentrations obtained from bacterial bioaerosols ranged between 67 and 423 CFU / m3, with an average value of 110.13 CFU / m3, which can represent a possible threat to the health of the workers and neonates in the ICU. The results indicated than Staphylococcus saprophyticus and Staphylococcus epidermidis predominated, especially in the fifth and sixth stages, which means second bronchi and alveoli. While Staphylococcus was the most prevalent genus, Alloiococcus otitidis, Bacillus subtiles, Bacillus thuringiensis, Kocuria rosea and Pseudomonas pseudoalcaligene occurred in the alveoli.