Skin injuries constitute a gateway for pathogenic bacteria that can be either part of tissue microbiota or acquired from the environmental. These microorganisms (such as Acinetobacter baumannii, Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus) produce virulence factors that impair tissue integrity and sustain the inflammatory phase leading for establishment of chronic wounds. The high levels of antimicrobial resistance have limited the therapeutic arsenal for combatting skin infections. Thus, the treatment of non-healing chronic wounds is a huge challenge for health services worldwide, imposing great socio-economic damage to the affected individuals. This scenario has encouraged the use of natural polymers, such as polysaccharide, in order to develop new formulations (membranes, nanoparticles, hydrogels, scaffolds) to be applied in the treatment of skin infections. In this non-exhaustive review, we discuss the applications of polysaccharide-based formulations in the healing of infected wounds in animal models and clinical trials. The formulations discussed in this review were prepared using alginate, cellulose, chitosan, and hyaluronic acid. In addition to have healing actions per se, these polysaccharide formulations can act as transdermal drug delivery systems, controlling the release of active ingredients (such as antimicrobial and healing agents). The papers show that these polysaccharides-based formulations are efficient in controlling infection and improve the healing, even in chronic infected wounds. These data should positively impact the design of new dressings to treat skin infections.

The skin is the largest organ in the human body, acting as a physical and immunological barrier against pathogenic microorganisms. The cutaneous lesions constitute a gateway for microbial contamination that can lead to chronic wounds and other invasive infections. Chronic wounds are considered as serious public health problems due the related social, psychological and economic consequences. The group of bacteria known as ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter sp.) are among the most prevalent bacteria in cutaneous infections. These pathogens have a high level of incidence in hospital environments and several strains present phenotypes of multidrug resistance. In this review, we discuss some important aspects of skin immunology and the involvement of ESKAPE in wound infections. First, we introduce some fundamental aspects of skin physiology and immunology related to cutaneous infections. Following this, the major virulence factors involved in colonization and tissue damage are highlighted, as well as the most frequently detected antimicrobial resistance genes. ESKAPE pathogens express several virulence determinants that overcome the skin’s physical and immunological barriers, enabling them to cause severe wound infections. The high ability these bacteria to acquire resistance is alarming, particularly in the hospital settings where immunocompromised individuals are exposed to these pathogens. Knowledge about the virulence and resistance markers of these species is important in order to develop new strategies to detect and treat their associated infections.

Water quality is mainly assessed using traditional water quality assessment methods that measure chemical parameters against established standards. The water quality index is used worldwide for water quality assessment. The main parameters evaluated include the total dissolved solids, electrical conductivity, nitrite, and nitrate. In this study, the WQI combined with microbiological analyses was used to assess the water quality of two rivers, Munim and Iguará. Data obtained in this study were then correlated using multivariate statistical analysis. Principal component analysis grouped the monitored sampling points into three clusters and identified temperature, Escherichia coli, and turbidity, as features correlated to the rainy season, while phosphorus, total dissolved solids, and biochemical oxygen demand are associated with the dry season. Four principal components explained 81.20% of the data variance during the studied seasons. The evaluated correlations indicated that in the rainy season, E. coli (~443.63 CFU/100 mL) and turbidity (~36.51 NTU) levels were the highest. However, in the dry season, the levels of phosphorus (~4.25 mg·L⁻¹), total dissolved solids (145.46 mg·L⁻¹), and dissolved oxygen (~9.89 mg·L⁻¹) were the highest.

The objective of this study was to evaluate the antibacterial action of filamentous bacteria isolated from the Byrsonima crassifolia leaf. An endophytic bacterium has been identified by classical and molecular techniques as Streptomyces ansochromogene. Screening for antibacterial action against pathogens with medical relevance (Klebsiella pneumoniae ATCC 700603, Pseudomonas aeruginosa ATCC 15692, Staphylococcus aureus ATCC 6538, Corynebacterium diphtheriae ATCC 27012, Mycobacterium abscessus, Cryptococcus gattii ATCC 24065, and Cryptococcus neoformans ATCC 24067) demonstrated activity against the bacterium P. aeruginosa ATCC 0030 with inhibition diameter zones (IDZ) of 17.6 ± 0.25 mm in the preliminary screening in solid medium. After fermentation in liquid medium, an IDZ of 19.6 ± 0.46 mm and a minimum inhibitory concentration (MIC) of 0.5 mg/mL were detected. The antibiofilm action was observed with 100% inhibition of biofilm formation at a concentration of 0.250 mg/mL. When the infection curve was prepared, it was observed that the metabolite was effective in protecting the larvae of Tenebrio molitor. The metabolite does not show toxicity for eukaryotic cells. The leishmanicidal activity demonstrated that the metabolite presented a dose-dependent effect on the promastigotes forms of Leishmania amazonensis growth and the estimated IC₅₀/72 h was 71.65 ± 7.4 μg/mL. Therefore, it can be concluded that the metabolite produced by the endophytic bacterium Streptomyces sp. is promising for future use as an alternative strategy against bacterial resistance.

Fruit juices have been emerging as excellent vehicles for development of probiotic products due to their nutritional properties and presence of bioactive compounds. This work evaluated the growth and viability of Limosilactobacillus fermentum ATCC 23271 and Lacticaseibacillus rhamnosus ATCC 9595 in bacuri juice (Platonia insignis Mart., Clusiaceae). Both strains were able to grow in bacuri juice, without any supplementation. Viability was kept after 28 days of storage; however, growth was significantly higher for L. rhamnosus ATCC 9595 (7.40 ± 0.04 Log CFU/mL). Following this, the effects of bacterial inoculum and pulp concentration on growth and lactic acid production by L. rhamnosus ATCC 9595 were investigated using a central composite rotational design. The inoculum concentration was the main factor for obtaining the most favorable relation between growth and organic acid production (G/pH ratio). Among the tested conditions, those used in assay 6 allowed the best G/pH ratio (2.13) and higher lactic acid production (4.14 g/L). In these conditions, L. rhamnosus ATCC 9595 grown in bacuri juice showed the same resistance towards acidification or addition of lysozyme than when cultivated in MRS. Finally, the anti-infective effects of fermented and non-fermented juices were analyzed using Tenebrio molitor larvae infected by enteroaggregative Escherichia coli 042. The pre-treatment with supernatants of both fermented and non-fermented juices significantly increased the survival of E. coli-infected larvae. However, only the L. rhamnosus-fermented juice had protective effects when inoculated 2 h after infection. Collectively, the results obtained in this research allowed the basis for the development of a non-dairy probiotic product from bacuri juice.