Prevalence and mortality rate of sepsis among adults admitted to hospitals in sub-Saharan Africa: a systematic review and meta-analysis.

Due to abundant pathogen diversity and mounting antimicrobial resistance, sepsis is more common in sub-Saharan Africa (sSA). However, there is a lack of consistent reports regarding the prevalence of adult sepsis in the region. Therefore, this study aimed to determine pooled estimates of sepsis prevalence and associated mortality among adults admitted to hospitals in sSA. Medline (through PubMed), Scopus, Embase, and Web of Science were systematically searched for studies of sepsis in sSA published before 13th February 2023. A random-effects meta-analysis of hospital-wide and intensive care unit (ICU)-based sepsis prevalence was performed with a 95% confidence interval (CI). Subgroup analysis was conducted considering geographic region and sepsis diagnostic criteria. Funnel plots and Egger's test were used to assess publication bias. The protocol was submitted to the Prospective Register for Systematic Reviews (PROSPERO) with an identifier (CRD42023396719). Overall, 14 observational studies, published between 2009 and 2022, from eight different sSA countries comprising 31,653 adult patients (5723 with sepsis) were included in the review. Nine studies that were conducted in a hospital-wide setting showed a pooled prevalence and mortality of 17% (95% CI: 12-21%) and 15% (95% CI: 17-35%), respectively. Five studies in the ICUs presented a pooled prevalence and mortality of 31% (95% CI: 24-38%) and 46% (95% CI: 39-54%), respectively. Based on the sub-group analysis, the pooled hospital-wide prevalence of sepsis in East and Southern Africa was 18% (95% CI: 11-25%), and 20% (95% CI: 2-42%), respectively. The pooled prevalence in the ICU was 14% (95% CI: 4-23%) and 13% (95% CI: 5-20%) for East and Southern Africa, respectively. The hospital-wide and ICU-based sepsis prevalence and mortality are high in sSA. Addressing the burden of adult sepsis should be a priority for healthcare systems in sub-Saharan Africa.

Partial characterization of biosurfactant from Lactobacillus pentosus and comparison with sodium dodecyl sulphate for the bioremediation of hydrocarbon contaminated soil.

The capability of a cell bound biosurfactant produced by Lactobacillus pentosus, to accelerate the bioremediation of a hydrocarbon-contaminated soil, was compared with a synthetic anionic surfactant (sodium dodecyl sulphate SDS-). The biosurfactant produced by the bacteria was analyzed by Fourier transform infrared spectroscopy (FTIR) that clearly indicates the presence of OH and NH groups, C=O stretching of carbonyl groups and NH nebding (peptide linkage), as well as CH2-CH3 and C-O stretching, with similar FTIR spectra than other biosurfactants obtained from lactic acid bacteria. After the characterization of biosurfactant by FTIR, soil contaminated with 7,000 mg Kg(-1) of octane was treated with biosurfactant from L. pentosus or SDS. Treatment of soil for 15 days with the biosurfactant produced by L. pentosus led to a 65.1% reduction in the hydrocarbon concentration, whereas SDS reduced the octane concentration to 37.2% compared with a 2.2% reduction in the soil contaminated with octane in absence of biosurfactant used as control. Besides, after 30 days of incubation soil with SDS or biosurfactant gave percentages of bioremediation around 90% in both cases. Thus, it can be concluded that biosurfactant produced by L. pentosus accelerates the bioremediation of octane-contaminated soil by improving the solubilisation of octane in the water phase of soil, achieving even better results than those reached with SDS after 15-day treatment.

Poly(dimethyl siloxane) surface modification with biosurfactants isolated from probiotic strains.

Depending on the final application envisaged for a given biomaterial, many surfaces must be modified before use. The material performance in a biological environment is mainly mediated by its surface properties that can be improved using suitable modification methods. The aim of this work was to coat poly(dimethyl siloxane) (PDMS) surfaces with biosurfactants (BSs) and to evaluate how these compounds affect the PDMS surface properties. BSs isolated from four probiotic strains (Lactococcus lactis, Lactobacillus paracasei, Streptococcus thermophilus A, and Streptococcus thermophilus B) were used. Bare PDMS and PDMS coated with BSs were characterized by contact angle measurements, infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The influence of the surface modifications on the materials blood compatibility was studied through thrombosis and hemolysis assays. The cytotoxicity of these materials was tested against rat peritoneal macrophages. AFM results demonstrated the successful coating of the surfaces. Also, by contact angle measurements, an increase of the coated surfaces hydrophilicity was seen. Furthermore, XPS analysis indicated a decrease of the silicon content at the surface, and ATR-FTIR results showed the presence of BS characteristic groups as a consequence of the modification. All the studied materials revealed no toxicity and were found to be nonhemolytic. The proposed approach for the modification of PDMS surfaces was found to be effective and opens new possibilities for the application of these surfaces in the biomedical field.

Antimicrobial and antiadhesive properties of a biosurfactant isolated from Lactobacillus paracasei ssp. paracasei A20.

AIMS: The aim of this study was to determine the antimicrobial and antiadhesive properties of a biosurfactant isolated from Lactobacillus paracasei ssp. paracasei A20 against several micro-organisms, including Gram-positive and Gram-negative bacteria, yeasts and filamentous fungi. METHODS AND RESULTS: Antimicrobial and antiadhesive activities were determined using the microdilution method in 96-well culture plates. The biosurfactant showed antimicrobial activity against all the micro-organisms assayed, and for twelve of the eighteen micro-organisms (including the pathogenic Candida albicans, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus agalactiae), the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were achieved for biosurfactant concentrations between 25 and 50 mg ml(-1). Furthermore, the biosurfactant showed antiadhesive activity against most of the micro-organisms evaluated. CONCLUSIONS: As far as we know, this is the first compilation of data on antimicrobial and antiadhesive activities of biosurfactants obtained from lactobacilli against such a broad group of micro-organisms. Although the antiadhesive activity of biosurfactants isolated from lactic acid bacteria has been widely reported, their antimicrobial activity is quite unusual and has been described only in a few strains. SIGNIFICANCE AND IMPACT OF THE STUDY: The results obtained in this study regarding the antimicrobial and antiadhesive properties of this biosurfactant opens future prospects for its use against micro-organisms responsible for diseases and infections in the urinary, vaginal and gastrointestinal tracts, as well as in the skin, making it a suitable alternative to conventional antibiotics.

Agrobacterium tumefaciens-mediated transformation of the antitumor clavaric acid-producing basidiomycete Hypholoma sublateritium.

The basidiomycete Hypholoma sublateritium produces clavaric acid, an antitumor isoprenoid compound. Arthrospores of this fungus were transformed by Agrobacterium tumefaciens-mediated conjugation. Five plasmids carrying different regulatory sequences to drive expression of the hph (hygromycin phosphotransferase) gene were tested. The promoter used was critically important in order to express heterologous genes in H. sublateritium. Constructions carrying the Agaricus bisporus glyceraldehyde-3-phosphate dehydrogenase promoter (P gpd) showed a good transformation efficiency, whereas constructions with the gpd promoter from ascomycetes were ineffective. Transformant clones showed a random integration pattern of plasmid DNA. Most transformants showed a single integrated copy of the transforming plasmid, but about 1.5% showed double or multiple integrations. All the analyzed transformants were mitotically stable and maintained the integrated exogenous DNA in the absence of antibiotic. The green fluorescent protein gene was expressed from the A. bisporus gpd promoter, as shown by RT-PCR studies, but no significant fluorescence was observed. Transformation of H. sublateritium opens the way for the genetic manipulation of clavaric acid biosynthesis in this fungus.