Omics technology draws a comprehensive heavy metal resistance strategy in bacteria.

The rapid industrial revolution significantly increased heavy metal pollution, becoming a major global environmental concern. This pollution is considered as one of the most harmful and toxic threats to all environmental components (air, soil, water, animals, and plants until reaching to human). Therefore, scientists try to find a promising and eco-friendly technique to solve this problem i.e., bacterial bioremediation. Various heavy metal resistance mechanisms were reported. Omics technologies can significantly improve our understanding of heavy metal resistant bacteria and their communities. They are a potent tool for investigating the adaptation processes of microbes in severe conditions. These omics methods provide unique benefits for investigating metabolic alterations, microbial diversity, and mechanisms of resistance of individual strains or communities to harsh conditions. Starting with genome sequencing which provides us with complete and comprehensive insight into the resistance mechanism of heavy metal resistant bacteria. Moreover, genome sequencing facilitates the opportunities to identify specific metal resistance genes, operons, and regulatory elements in the genomes of individual bacteria, understand the genetic mechanisms and variations responsible for heavy metal resistance within and between bacterial species in addition to the transcriptome, proteome that obtain the real expressed genes. Moreover, at the community level, metagenome, meta transcriptome and meta proteome participate in understanding the microbial interactive network potentially novel metabolic pathways, enzymes and gene species can all be found using these methods. This review presents the state of the art and anticipated developments in the use of omics technologies in the investigation of microbes used for heavy metal bioremediation.

Microbial communities in petroleum refinery effluents and their complex functions.

Petroleum refinery effluents (PRE) are a significant cause of pollution. It contains toxic compounds such as total petroleum hydrocarbons (TPH), and polycyclic aromatic hydrocarbons (PAHs), as well as heavy metals. They show a huge threat facing the aquaculture habitats, human health, and the environment if they are not treated before discharging into the environment. Physical and chemical procedures are used to treat hydrocarbon pollution in PRE, but these techniques often result in the formation of hazardous by-products during the remediation process. However, PRE contains various microbial communities, including bacteria, yeast, microalgae, and fungi. The bioremediation and biodegradation of oil contaminants are the primary functions of these microbial communities. However, these microorganisms can perform various additional functions including but not limited to heavy metals removal, production of biosurfactants, and nitrogen fixation. This review contributes to the comprehension of natural microbial communities and their complex functions in petroleum refinery effluents. Understanding microbial communities would facilitate the advancement of innovative biotechnology aimed at treating PRE, improving bioremediation processes, and potentially transforming PRE into valuable bio-products. Moreover, it assists in determining the most effective bioaugmentation strategy to enhance biodegradation and bioremediation in PRE. The review highlights the potential for sustainable green approaches using microbial communities to replace toxic chemical therapies and expensive physical treatments in the future.

Incidence of Drug-Resistant Hospital-Associated Gram-Negative Bacterial Infections, the Accompanying Risk Factors, and Clinical Outcomes with Treatment.

Extensive drug resistance to bacterial infections in hospitalised patients is accompanied by high morbidity and mortality rates due to limited treatment options. This study investigated the clinical outcomes of single and combined antibiotic therapies in extensive (XDR), multidrug-resistant (MDR) and susceptible strains (SS) of hospital-acquired infections (HAIs). Cases of hospital-associated drug-resistant infections (HADRIs) and a few susceptible strains from hospital wards were selected for this study. Bacteria identifications (IDs) and antimicrobial susceptibility tests (ASTs) were performed with a Vitek 2 Compact Automated System. Patients' treatment types and clinical outcomes were classified as alive improved (AI), alive not improved (ANI), or died. The length of hospital stay (LOHS) was acquired from hospital records. The HAI pathogens were Acinetobacter baumannii (28%), Escherichia coli (26%), Klebsiella pneumoniae (22%), Klebsiella (2%) species, Pseudomonas aeruginosa (12%), Proteus mirabilis (4%), and other Enterobacteriaceae. They were MDR (40.59%), XDR (24.75%), carbapenem-resistant Enterobacteriaceae (CRE, 21.78%) and susceptible (12%) strains. The treatments were either monotherapy or combined therapy with different outcomes. Monotherapy produced positive significant outcomes with E. coli infections, while for P. aeruginosa, there were no differences between the number of infections treated with either mono/combined therapies (50% each). Nonetheless, combined therapy had significant effects (p < 0.05) as a treatment for A. baumannii and K. pneumoniae infections. Clinical outcomes and LOHS varied with infecting bacteria. The prevalence of XDR and MDR HAIs was found to be significantly high, with no association with treatment type, LOHS, or outcome.

The Palliative and Antioxidant Effects of Hesperidin against Lead-Acetate-Induced Testicular Injury in Male Wistar Rats.

Lead (Pb)-induced reprotoxicity is a detrimental consequence of Pb exposure, which results in abnormal spermatogenesis, testicular degeneration, and pathogenic sperm changes. The association between impaired male reproductive function and Pb-induced oxidative stress (OS) has been demonstrated, with consequent testicular antioxidant deficiency. The current study investigated the protective role of the natural antioxidant hesperidin (HSD) against lead-acetate (PbAc)-induced testicular toxicity. Male Wistar rats (n = 40) were randomly divided into four experimental groups: Group I (negative control) received 2.0 mL/kg BW 0.9% saline; Group II received 100 mg/kg BW PbAc; Group III received 100 mg/kg BW HSD; and Group IV received HSD two hours before PbAc using the abovementioned doses. The treatments were administered daily for 30 consecutive days. The results showed that HSD treatment significantly restored PbAc-induced decrease in body, epididymal, and testicular weights as well as in semen parameters, reproductive hormones, and testicular markers of OS. Reduced MDA levels and improved testicular histopathological findings were also observed. Collectively, this study sheds light on the preventive role of HSD against PbAc-induced testicular injury, which is mediated via the suppression of OS and the modulation of reproductive hormones as well as the plausibility of HSD being used as a supplementary therapeutic option for recovery.

Draft genome analysis for Enterobacter kobei, a promising lead bioremediation bacterium.

Lead pollution of the environment poses a major global threat to the ecosystem. Bacterial bioremediation offers a promising alternative to traditional methods for removing these pollutants, that are often hindered by various limitations. Our research focused on isolating lead-resistant bacteria from industrial wastewater generated by heavily lead-containing industries. Eight lead-resistant strains were successfully isolated, and subsequently identified through molecular analysis. Among these, Enterobacter kobei FACU6 emerged as a particularly promising candidate, demonstrating an efficient lead removal rate of 83.4% and a remarkable lead absorption capacity of 571.9 mg/g dry weight. Furthermore, E. kobei FACU6 displayed a remarkable a maximum tolerance concentration (MTC) for lead reaching 3,000 mg/L. To further investigate the morphological changes in E. kobei FACU6 in response to lead exposure, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed. These analyses revealed significant lead adsorption and intracellular accumulation in treated bacteria in contrast to the control bacterium. Whole-genome sequencing was performed to gain deeper insights into E. kobei's lead resistance mechanisms. Structural annotation revealed a genome size of 4,856,454 bp, with a G + C content of 55.06%. The genome encodes 4,655 coding sequences (CDS), 75 tRNA genes, and 4 rRNA genes. Notably, genes associated with heavy metal resistance and their corresponding regulatory elements were identified within the genome. Furthermore, the expression levels of four specific heavy metal resistance genes were evaluated. Our findings revealed a statistically significant upregulation in gene expression under specific environmental conditions, including pH 7, temperature of 30°C, and high concentrations of heavy metals. The outstanding potential of E. kobei FACU6 as a source of diverse genes related to heavy metal resistance and plant growth promotion makes it a valuable candidate for developing safe and effective strategies for heavy metal disposal.

Hydrothermal Synthesis of Multifunctional Bimetallic Ag-CuO Nanohybrids and Their Antimicrobial, Antibiofilm and Antiproliferative Potential.

The rapidly growing global problem of infectious pathogens acquiring resistance to conventional antibiotics is an instigating reason for researchers to continue the search for functional as well as broad-spectrum antimicrobials. Hence, we aimed in this study to synthesis silver-copper oxide (Ag-CuO) nanohybrids as a function of Ag concentration (0.05, 0.1, 0.3 and 0.5 g) via the one-step hydrothermal method. The bimetallic Ag-CuO nanohybrids Ag-C-1, Ag-C-2, Ag-C-3 and Ag-C-4 were characterized for their physico-chemical properties. The SEM results showed pleomorphic Ag-CuO crystals; however, the majority of the particles were found in spherical shape. TEM results showed that the Ag-CuO nanohybrids in formulations Ag-C-1 and Ag-C-3 were in the size range of 20-35 nm. Strong signals of Ag, Cu and O in the EDX spectra revealed that the as-synthesized nanostructures are bimetallic Ag-CuO nanohybrids. The obtained Ag-C-1, Ag-C-2, Ag-C-3 and Ag-C-4 nanohybrids have shown their MICs and MBCs against E. coli and C. albicans in the range of 4-12 mg/mL and 2-24 mg/mL, respectively. Furthermore, dose-dependent toxicity and apoptosis process stimulation in the cultured human colon cancer HCT-116 cells have proven the Ag-CuO nanohybrids as promising antiproliferative agents against mammalian cancer.

pH-Responsive PVA/BC-f-GO Dressing Materials for Burn and Chronic Wound Healing with Curcumin Release Kinetics.

Polymeric materials have been essential biomaterials to develop hydrogels as wound dressings for sustained drug delivery and chronic wound healing. The microenvironment for wound healing is created by biocompatibility, bioactivity, and physicochemical behavior. Moreover, a bacterial infection often causes the healing process. The bacterial cellulose (BC) was functionalized using graphene oxide (GO) by hydrothermal method to have bacterial cellulose-functionalized-Graphene oxide (BC-f-GO). A simple blending method was used to crosslink BC-f-GO with polyvinyl alcohol (PVA) by tetraethyl orthosilicate (TEOS) as a crosslinker. The structural, morphological, wetting, and mechanical tests were conducted using Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), water contact angle, and a Universal testing machine (UTM). The release of Silver-sulphadiazine and drug release kinetics were studied at various pH levels and using different mathematical models (zero-order, first-order, Higuchi, Hixson, Korsmeyer-Peppas, and Baker-Lonsdale). The antibacterial properties were conducted against Gram-positive and Gram-negative severe infection-causing pathogens. These composite hydrogels presented potential anticancer activities against the U87 cell line by an increased GO amount. The result findings show that these composite hydrogels have physical-mechanical and inherent antimicrobial properties and controlled drug release, making them an ideal approach for skin wound healing. As a result, these hydrogels were discovered to be an ideal biomaterial for skin wound healing.

Comparison of the Response of Bacterial IscU and SufU to Zn2+ and Select Transition-Metal Ions.

IscU, the central scaffold protein in the bacterial ISC iron-sulfur (Fe-S) cluster biosynthesis system, has long been recognized to bind a Zn2+ ion at its active site. While initially regarded as an artifact, Zn2+ binding has been shown to induce stabilization of the IscU structure that may mimic a state biologically relevant to IscU's role in Fe-S cluster biosynthesis. More recent studies have revealed that SufU, a homologous protein involved in Fe-S cluster biosynthesis in Gram-positive bacteria, also binds a Zn2+ ion with structural implications. Given the widespread occurrence of the "IscU-like" protein fold, particularly among Fe-S cluster biosynthesis systems, an interesting question arises as to whether Zn2+ ion binding and the resulting structural alterations are common properties in IscU-like proteins. Interactions between IscU and specific metal ions are investigated and compared side-by-side with those of SufU from a representative Gram-positive bacterium in the phylum Firmicutes. These studies were extended with additional transition metal ions chosen to investigate the influence of coordination geometry on selectivity for binding at the active sites of IscU and SufU. Monitoring and comparing the conformational behavior and stabilization afforded by different transition metal ions upon IscU and SufU revealed similarities between the two proteins and suggest that metal-dependent conformational transitions may be characteristic of U-type proteins involved in Fe-S cluster biosynthesis.