Study on the Anticancer Activity of Prodigiosin from Variants of Serratia Marcescens QBN VTCC 910026

Insights into the Genome of a New Strain Serratia rubidaea XU1 Isolated from Radioactive Soil and its Prodigiosin Production and Antimicrobial Properties

The genus Serratia is a typical red bacterium involved in prodigiosin synthesis. Here, we report the genome sequence of Serratia rubidaea XU1, which was isolated from radiation-contaminated soil in Xinjiang, China. The genome of XU1 is composed of 4,972,898 base pairs with a GC content of 59.25%. The genome sequence contains 4707 genes and encodes 4573 proteins, 79 tRNAs, and 17 rRNAs. The prodigiosin biosynthesis gene cluster was identified and analyzed, showing a sequence similarity of 85.55-96.02% with Serratia rubidaea. After optimizing the biosynthesis process, XU1 was able to achieve a maximum titer of 574 units/cell of prodigiosin at a pH of 7.5 and a temperature of 25 °C for 36 h. Glycerol at 20 g/L and beef extract at 5 g/L were used as the carbon and nitrogen sources, respectively. Prodigiosin extracted from XU1 demonstrated inhibition of Escherichia coli, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa. The availability of the sequenced genome of XU1 will be greatly beneficial and contribute to complementary studies on the biosynthetic mechanisms of prodigiosin.

Anticancer and Immunomodulatory Activities of Prodigiosin Extracted and Purified from Serratia marcescens

BACKGROUND

Prodigiosin is a naturally occurring compound produced by various bacteria, including Serratia marcescens. It is known for its diverse biological properties. The present study was conducted to extract and purify prodigiosin from Serratia marcescens and investigate its anticancer and immunomodulatory activities.

METHODS

S. presence was isolated from soil samples and characterized. Different solvents were used to extract prodigiosin from Serratia marcescens. The cytotoxic activity of prodigiosin was tested against human rhabdomyosarcoma (RD), rat embryo fibroblasts (REF), and human breast cancer MDA-MB-231 (MDA) epithelial cell lines. Albino mice were divided into six groups: Negative control (normal saline); positive control (injected with 100 µ l of Serratia marcesence); groups A-D were injected with 100 µ l of prodigiosin (1, 3, 6, and 9 µ g/mouse, respectively). After 14 days of treatment, whole blood samples were collected for immunomodulatory analysis.

RESULTS

The study found that the highest yield of prodigiosin (65-230 mg/l) was obtained with methanol as the extraction solvent. Prodigiosin had a cytotoxic effect on cancer cells, particularly against MDA epithelial cells. However, it did not have a cytotoxic effect on normal cells. Immunological analysis revealed significant differences (p ≤ 0.01) in absolute neutrophil counts between the positive control and prodigiosin-treated groups, with the highest value in group C and the lowest in group A. Immunological analysis showed significant differences in neutrophil counts, IL-4, and IL-10 levels between prodigiosin-treated groups and the control group.

CONCLUSION

Serratia marcescens prodigiosin showed cytotoxic effects on cancer cells and boosted IL-10 and IL-4 serum levels, acting as an immunomodulator.

Serratia marcescens ATCC 274 increases production of the red pigment prodigiosin in response to Chi phage infection

Serratia marcescens is an opportunistic human pathogen that produces a vibrant red pigment called prodigiosin. Prodigiosin has implications in virulence of S. marcescens and promising clinical applications. We discovered that addition of the virulent flagellotropic bacteriophage χ (Chi) to a culture of S. marcescens stimulates a greater than fivefold overproduction of prodigiosin. Active phage infection is required for the effect, as a χ-resistant strain lacking flagella does not respond to phage presence. Via a reporter fusion assay, we have determined that the addition of a χ-induced S. marcescens cell lysate to an uninfected culture causes a threefold increase in transcription of the pig operon, containing genes essential for pigment biosynthesis. Replacement of the pig promoter with a constitutive promoter abolished the pigmentation increase, indicating that regulatory elements present in the pig promoter likely mediate the phenomenon. We hypothesize that S. marcescens detects the threat of phage-mediated cell death and reacts by producing prodigiosin as a stress response. Our findings are of clinical significance for two main reasons: (i) elucidating complex phage-host interactions is crucial for development of therapeutic phage treatments, and (ii) overproduction of prodigiosin in response to phage could be exploited for its biosynthesis and use as a pharmaceutical.

Cancer therapy with the viral and bacterial pathogens: The past enemies can be considered the present allies

Cancer continues to be one of the leading causes of mortality worldwide despite significant advancements in cancer treatment. Many difficulties have arisen as a result of the detrimental consequences of chemotherapy and radiotherapy as a common cancer therapy, such as drug inability to penetrate deep tumor tissue, and also the drug resistance in tumor cells continues to be a major concern. These obstacles have increased the need for the development of new techniques that are more selective and effective against cancer cells. Bacterial-based therapies and the use of oncolytic viruses can suppress cancer in comparison to other cancer medications. The tumor microenvironment is susceptible to bacterial accumulation and proliferation, which can trigger immune responses against the tumor. Oncolytic viruses (OVs) have also gained considerable attention in recent years because of their potential capability to selectively target and induce apoptosis in cancer cells. This review aims to provide a comprehensive summary of the latest literature on the role of bacteria and viruses in cancer treatment, discusses the limitations and challenges, outlines various strategies, summarizes recent preclinical and clinical trials, and emphasizes the importance of optimizing current strategies for better clinical outcomes.

Transcriptomic analysis of cell envelope inhibition by prodigiosin in methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading threat to public health as it is resistant to most currently available antibiotics. Prodigiosin is a secondary metabolite of microorganisms with broad-spectrum antibacterial activity. This study identified a significant antibacterial effect of prodigiosin against MRSA with a minimum inhibitory concentration as low as 2.5 mg/L. The results of scanning electron microscopy, crystal violet staining, and confocal laser scanning microscopy indicated that prodigiosin inhibited biofilm formation in S. aureus USA300, while also destroying the structure of the cell wall and cell membrane, which was confirmed by transmission electron microscopy. At a prodigiosin concentration of 1.25 mg/L, biofilm formation was inhibited by 76.24%, while 2.5 mg/L prodigiosin significantly reduced the vitality of MRSA cells in the biofilm. Furthermore, the transcriptomic results obtained at 1/8 MIC of prodigiosin indicated that 235and 387 genes of S. aureus USA300 were significantly up- and downregulated, respectively. The downregulated genes were related to two-component systems, including the transcriptional regulator LytS, quorum sensing histidine kinases SrrB, NreA and NreB, peptidoglycan biosynthesis enzymes (MurQ and GlmU), iron-sulfur cluster repair protein ScdA, microbial surface components recognizing adaptive matrix molecules, as well as the key arginine synthesis enzymes ArcC and ArgF. The upregulated genes were mainly related to cell wall biosynthesis, as well as two-component systems including vancomycin resistance-associated regulator, lipoteichoic acid biosynthesis related proteins DltD and DltB, as well as the 9 capsular polysaccharide biosynthesis proteins. This study elucidated the molecular mechanisms through which prodigiosin affects the cell envelope of MRSA from the perspectives of cell wall synthesis, cell membrane and biofilm formation, providing new potential targets for the development of antimicrobials for the treatment of MRSA.

Red bioactive pigment from Himalayan Janthinobacterium sp. ERMR3:09: optimization, characterization, and potential applications

Prodigiosin is a red pigment commonly produced as a secondary metabolite by Serratia marcescens. It exhibits inherent bioactivities, including antimicrobial and anticancer, with low to no toxic effects on normal cells. The present study investigates a bioactive prodigiosin production from an atypical, red-pigmented, potentially novel Janthinobacterium sp. ERMR3:09 isolated from a glacial moraine. Statistically optimized culture parameters, i.e., w/v 1.0% glucose and 0.08% peptone as carbon and nitrogen sources, temperature 20 °C, and media pH 7, resulted in a four-fold increase in the pigment yield. The upscaled production in an 8 L volume resulted in higher pigment production within a shorter period of 48 h. The ultra-performance liquid chromatography (UPLC) analysis validated the identity of the purified pigment as prodigiosin that showed thermostability at 75 °C for 3 h. Evaluation of antimicrobial activity showed potent inhibitory effects (> 50%) against the opportunistic pathogenic fungal and Gram-positive bacterial strains. The pigment showed significant cytotoxicity (p < 0.05) towards A549 and HeLa cell lines with IC50 values of 42.2 μM and 36.11 μM, respectively. The study demonstrated that microbial communities from extreme niches can be ideal sources of bioactive pigments with immense pharmaceutical potential vital for the development of non-synthetic therapeutic agents.

The Golgi Apparatus as an Anticancer Therapeutic Target

Although the discovery of the Golgi apparatus (GA) was made over 125 years ago, only a very limited number of therapeutic approaches have been developed to target this complex organelle. The GA serves as a modification and transport center for proteins and lipids and also has more recently emerged as an important store for some ions. The dysregulation of GA functions is implicated in many cellular processes associated with cancer and some GA proteins are indeed described as cancer biomarkers. This dysregulation can affect protein modification, localization, and secretion, but also cellular metabolism, redox status, extracellular pH, and the extracellular matrix structure. Consequently, it can directly or indirectly affect cancer progression. For these reasons, the GA is an appealing anticancer pharmacological target. Despite this, no anticancer drug specifically targeting the GA has reached the clinic and few have entered the clinical trial stage. Advances in nanodelivery approaches may help change this scenario by specifically targeting tumor cells and/or the GA through passive, active, or physical strategies. This article aims to examine the currently available anticancer GA-targeted drugs and the nanodelivery strategies explored for their administration. The potential benefits and challenges of modulating and specifically targeting the GA function in the context of cancer therapy are discussed.

The Sustainable Bioactive Dyeing of Textiles: A Novel Strategy Using Bacterial Pigments, Natural Antibacterial Ingredients, and Deep Eutectic Solvents

The textile industry stands as a prominent contributor to global environmental pollution, primarily attributable to its extensive reliance on synthetic dyes, hazardous components, and solvents throughout the textile dyeing and treatment processes. Consequently, the pursuit of sustainable textile solutions becomes imperative, aimed at replacing these environmentally unfriendly constituents with biobased and bioactive pigments, antibacterial agents, and, notably, natural solvents. Achieving this goal is a formidable yet indispensable challenge. In this study, the dyeing ability of the crude gel prodigiosin, produced by non-pathogenic bacteria Serratia plymuthica, was investigated on various multifiber fabrics at different conditions (temperature and pH) and by using salts and alternative mordants (the conventional Ferrous Sulphate (FeSO4) and a new bio-mordant, L-Cysteine (L-Cys)). Additionally, a novel gel-based Choline chloride (ChCl)/Lactic acid (LA) (1:2) deep eutectic solvent (DES) dyeing medium was studied to replace the organic solvents. Nylon fabrics dyed with 3.0% over the weight of the fiber (owf) L-Cys at pH = 8.3 had improved color fastness to washing, while the gel-based ChCl/LA (1:2) DES dyebath provided a better color fastness to light. Moreover, nylon fabrics under these conditions exhibited remarkable antimicrobial activity against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). In conclusion, the utilization of the crude gel-based prodigiosin pigment demonstrates a distinct advantage in dyeing textile materials, aligning with the growing consumer demand for more eco-friendly and sustainable products. Additionally, the application of the natural reducing agent L-Cys, previously untested as a bio-mordant, in conjunction with the use of gel-based DES as a dyeing medium, has showcased improved colorimetric and antibacterial properties when applied to nylon that is dyed with the crude gel prodigiosin pigment.

Isolation, Identification, and Antibacterial Properties of Prodigiosin, a Bioactive Product Produced by a New Serratia marcescens JSSCPM1 Strain: Exploring the Biosynthetic Gene Clusters of Serratia Species for Biological Applications

Prodigiosin pigment has high medicinal value, so exploring this compound is a top priority. This report presents a prodigiosin bioactive compound isolated from Serratia marcescens JSSCPM1, a new strain. The purification process of this compound involves the application of different chromatographic methods, including UV-visible spectroscopy, high-performance liquid chromatography (HPLC), and liquid chromatography-mass spectrometry (LC/MS). Subsequent analysis was performed using nuclear magnetic resonance (NMR) to achieve a deeper understanding of the compound's structure. Finally, through a comprehensive review of the existing literature, the structural composition of the isolated bioactive compound was found to correspond to that of the well-known compound prodigiosin. The isolated prodigiosin compound was screened for antibacterial activity against both Gram-positive and Gram-negative bacteria. The compound inhibited the growth of Gram-negative bacterial strains compared with Gram-positive bacterial strains. It showed a maximum minimum inhibitory concentration against Escherichia coli NCIM 2065 at a 15.9 ± 0.31 μg/mL concentration. The potential binding capabilities between prodigiosin and the OmpF porin proteins (4GCS, 4GCP, and 4GCQ) were determined using in silico studies, which are generally the primary targets of different antibiotics. Comparative molecular docking analysis indicated that prodigiosin exhibits a good binding affinity toward these selected drug targets.

Prodigiosin as an antibiofilm agent against multidrug-resistant Staphylococcus aureus

Staphylococcus aureus is known for forming bacterial biofilms that confer increased antimicrobial resistance. Combining antibiotics with antibiofilm agents is an alternative approach, but the antibiofilm ability of prodigiosin (PG), a potential antibiotic synergist, against antimicrobial-resistant (AMR) S. aureus remains to be understood. The antibiofilm activity of PG against 29 clinical AMR S. aureus strains was evaluated using crystal violet staining, and its synergistic effects with vancomycin (VAN) was confirmed using the checkerboard test. The viability and metabolic activity of biofilms and planktonic cells were also assessed. The results revealed that PG exhibited promising inhibitory activity against biofilm formation and synergistic activity with VAN. It effectively reduced the metabolic activity of biofilms and suppressed the production of exopolysaccharides, which might be attributed to the downregulation of biofilm-related genes such as sarA, agrA, and icaA. These findings suggest that PG could be used as a preventive coating or adjuvant against biofilms in clinical settings.