Pesquisa de fatores de virulência em Pseudomonas aeruginosa isoladas de águas minerais naturais

Abstract

This study evaluated biofilm formation and antimicrobial susceptibility of Pseudomonas aeruginosa isolated to evaluate the microbiological quality of 80 natural mineral water samples sold in 20 L bottles. The quantity of P. aeruginosa and enterococci was assessed, including total coliforms, thermotolerant coliforms and sulfite-reducing clostridia (SRC). Biofilm production from P. aeruginosa was evaluated in brain heart infusion broth (BHI) and sterile natural mineral water at temperatures of 25 and 35°C for 24 and 48 h. Antimicrobial susceptibility tests were performed using the agar diffusion method (Kirby-Bauer). Of the 80 samples analyzed, 40 (50%) presented unsatisfactory microbiological quality according to RDC no. 275/05. Thirty-eight (47.5%) samples presented P. aeruginosa, nine (11.2%) total coliforms, four (5.0%) SRC and one (1.2%) thermotolerant coliform. Sixteen P. aeruginosa strains (51.6%) were classified as non-adherent or weakly adherent, both in BHI as in mineral water. However, five strains (16.1%) were strongly adherent in the two matrices, mainly in BHI at the temperature of 25ºC. The study also isolated resistant or intermediate resistant strains to antibiotics of aminoglycosides and/or β-lactams classes. It was concluded that P. aeruginosa isolates were able to produce biofilm in the studied matrices and presented resistance to antimicrobials. Half of the samples presented unsatisfactory microbiological quality, mostly due to P. aeruginosa contamination.

Occurrence of total coliforms,Escherichia coliandCronobacterspecies in commercially available 20 l bottled drinking water sold in Rio de Janeiro State, Brazil

“…Of the 15 brands analysed, nine (60·0%) gave an unsatisfactory result for at least one of the lots analysed. These results were similar of those reported by Pedrosa et al () who analysed 33 brands and observed that 57·6% gave unsatisfactory results. These results indicate that these products continue to represent risk for human consumption and agrees with earlier Brazilian Ministry of Health data (Brasil ).According to Pedrosa et al (), the water marketed in returnable bottles should be more closely controlled, especially in terms of its microbiological characteristics.…”

“…Ayaz et al (2017) evaluated the cleaning practices and contamination status of contents and teats of feeding bottles used by children admitted in a hospitals in Pakistan and observed that 5Á6% of the mothers/caretakers use natural mineral waters to prepare feeding bottle for children. It is notable therefore that previously studies in Brazil reported that 50-72% of samples of natural mineral waters sold in 20 l bottles were unsatisfactory for human consumption due to microbiological contamination, including the presence of indicators for faecal contamination (Brandao et al 2012;Pedrosa et al 2014).…”

“…Given that Cronobacter can cause infections in adults, the microbiological evaluation of drinking water is important as it is a potential route for colonization and transmission (Liu et al ). Due to the high consumption of natural mineral waters sold in 20 l returnable bottles by the adult population and previous studies have reported their contamination by bacterial indicators of faecal contamination (Brandao et al ; Pedrosa et al ), monitoring the quality of these products is very important.…”

Pseudomonas Aeruginosa: Virulence Factors and Antibiotic Resistance Genes

“…Biofilms are communities composed of microorganisms adhered to a biotic or abiotic surface surrounded by a matrix of exopolysaccharide (EPS), whose function is to guarantee the protection of the microorganisms existing in its interior against the attack of the microbial aggressions of the external or internal environment. Thus, when P. aeruginosa is submitted under stress conditions, the formation of biofilms are often associated with higher antimicrobial resistance when compared to the planktonic form and assists in the evasion of the host immune response (31)(32)(33)(34)(35)(36). Biofilm microorganisms also exhibit altered phenotype with respect to growth rate and gene transcription [35,35].…”

“…Thus, when P. aeruginosa is submitted under stress conditions, the formation of biofilms are often associated with higher antimicrobial resistance when compared to the planktonic form and assists in the evasion of the host immune response (31)(32)(33)(34)(35)(36). Biofilm microorganisms also exhibit altered phenotype with respect to growth rate and gene transcription [35,35]. P. aeruginosa is a Gram-negative bacillus involved in opportunistic diseases, particularly in immunocompromised patients, which may cause several diseases as dermatitis, urinary infections and a wide variety of systemic infections, especially in hospital infections [36].…”