Cyanobacteria derived compounds: Emerging drugs for cancer management.

The wide diversity of cyanobacterial species and their role in a variety of biological activities have been reported in the previous few years. Cyanobacteria, especially from marine sources, constitutes a major source of biologically active metabolites that have gained great attention especially due to their anticancer potential. Numerous chemically diverse metabolites from various cyanobacterial species have been recognized to inhibit the growth and progression of tumor cells through the induction of apoptosis in many different types of cancers. These metabolites activate the apoptosis in the cancer cells by different molecular mechanisms, however, the dysregulation of the mitochondrial pathway, death receptors signaling pathways, and the activation of several caspases are the crucial mechanisms that got considerable interest. The array of metabolites and the range of mechanisms involved may also help to overcome the resistance acquired by the different tumor types against the ongoing therapeutic agents. Therefore, the primary or secondary metabolites from the cyanobacteria as well as their synthetic derivates could be used to develop novel anticancer drugs alone or in combination with other chemotherapeutic agents. In this study, we have discussed the role of cyanobacterial metabolites in the induction of cytotoxicity and the potential to inhibit the growth of cancer cells through the induction of apoptosis, cell signaling alteration, oxidative damage, and mitochondrial dysfunctions. Moreover, the various metabolites produced by cyanobacteria have been summarized with their anticancer mechanisms. Furthermore, the ongoing trials and future developments for the therapeutic implications of these compounds in cancer therapy have been discussed.

Integrating Pharmacological and Computational Approaches for the Phytochemical Analysis of Syzygium cumini and Its Anti-Diabetic Potential.

Diabetes mellitus (DM) is a metabolic disease caused by improper insulin secretion leading to hyperglycemia. Syzygium cumini has excellent therapeutic properties due to its high levels of phytochemicals. The current research aimed to evaluate the anti-diabetic potential of S. cumini plant's seeds and the top two phytochemicals (kaempferol and gallic acid) were selected for further analysis. These phytochemicals were selected via computational tools and evaluated for α-Glucosidase inhibitory activity via enzymatic assay. Gallic acid (IC50 0.37 µM) and kaempferol (IC50 0.87 µM) have shown a stronger α-glucosidase inhibitory capacity than acarbose (5.26 µM). In addition, these phytochemicals demonstrated the highest binding energy, hydrogen bonding, protein-ligand interaction and the best MD simulation results at 100 ns compared to acarbose. Furthermore, the ADMET properties of gallic acid and kaempferol also fulfilled the safety criteria. Thus, it was concluded that S. cumini could potentially be used to treat DM. The potential bioactive molecules identified in this study (kaempferol and gallic acid) may be used as lead drugs against diabetes.

Aluminium oxide nanoparticles inhibit EPS production, adhesion and biofilm formation by multidrug resistant Acinetobacter baumannii.

Acinetobacter baumannii is a biofilm forming multidrug resistant (MDR) pathogen responsible for respiratory tract infections. In this study, aluminium oxide nanoparticles (Al2O3 NPs) were synthesized and characterized by TEM and EDX and shown to be spherical shaped nanoparticles with a diameter < 10 nm. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) for the Al2O3 NPs ranged between 125 and 1,000 µg ml-1. Exposure to NPs caused cellular membrane disruption, indicated by an increase in cellular leakage of the contents. Biofilm inhibition was 11.64 to 70.2%, whereas attachment of bacteria to polystyrene surfaces was reduced to 48.8 to 51.9% in the presence of NPs. Nanoparticles also reduced extracellular polymeric substance production and the biomass of established biofilms. The data revealed the non-toxic nature of Al2O3 NPs up to a concentrations of 120 µg ml-1 in HeLa cell lines. These results demonstrate an effective and safer use of Al2O3 NPs against the MDR A. baumannii by targeting biofilm formation, adhesion and EPS production.

Cadmium induces GAPDH- and- MDH mediated delayed cell aging and dysfunction in Candida tropicalis 3Aer.

Eukaryotes employ various mechanisms to survive environmental stress conditions. Multicellular organisms eliminate permanently damaged cells by apoptosis, while unicellular eukaryotes like yeast react by decelerating cell aging. In the present study, transcriptomic and proteomic approaches were employed to elucidate the underlying mechanism of delayed apoptosis. Our findings suggest that Candida tropicalis 3Aer has a set of tightly controlled genes that are activated under Cd+2 exposition. Acute exposure to Cd+2 halts the cell cycle at the G2/M phase checkpoint and activates multiple cytoplasmic proteins that overcome effects of Cd+2-induced reactive oxygen species. Prolonged Cd+2 stress damages DNA and initiates GAPDH amyloid formation. This is the first report that Cd+2 challenge initiates dynamic redistribution of GAPDH and MDH and alters various metabolic pathways including the pentose phosphate pathway. In conclusion, the intracellular redistribution of GAPDH and MDH induced by prolonged cadmium stress modulates various cellular reactions, which facilitate delayed aging in the yeast cell.

Molecular basis of Cd+2 stress response in Candida tropicalis.

This study examines the bioremediation potential and cadmium-induced cellular response on a molecular level in Candida tropicalis 3Aer. Spectroscopic analysis clearly illustrated the involvement of yeast cell wall components in biosorption. Cadmium bioaccumulation was confirmed by TEM, SEM, and EDX examination. TEM images revealed extracellular as well as cytoplasmic and vacuolar cadmium nanoparticle formation, further validated by presence of ycf1 gene and increased biosynthesis of GSH under cadmium stress. Fourteen proteins exhibited differential expression and during cellular redox homeostasis are found to involve in nitrogen metabolism, nucleotide biosynthesis, and carbohydrate catabolism. Interestingly, C. tropicalis 3Aer is equipped with nitrile hydratase enzyme, rarely been reported in yeast. It has the potential to remove nitriles from the environment. The Cd+2 toxicity not only caused growth stasis but also upregulated the cysteine biosynthesis, protein folding and cytoplasmic detoxification response elements. The present study suggests that C. tropicalis 3Aer is a potential candidate for bioremediating environmental pollution by Cd+2.

Cadmium resistance mechanism in Escherichia coli P4 and its potential use to bioremediate environmental cadmium.

A cadmium-resistant bacterium was isolated from industrial wastewater and identified as Escherichia coli (dubbed as P4) on the basis of morphological, biochemical tests and 16S rRNA ribotyping. It showed optimum growth at 30 °C and pH 7. E. coli P4 found to resist Cd(+2) (10.6 mM) as well as Zn(+2) (4.4 mM), Pb(+2) (17 mM), Cu(+2) (3.5 mM), Cr(+6) (4.4 mM), As(+2) (10.6 mM), and Hg(+2) (0.53 mM). It could remove 18.8, 37, and 56 % Cd(+2) from aqueous medium after 48, 96, and 144 h, respectively. Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and Energy-dispersive X-ray (EDX) analysis also confirmed the biosorption of Cd(+2) by E. coli P4. However, temperature and pH were found to be the most critical factors in biosorption of Cd(+2) by E. coli P4. Cd(+2) stress altered E. coli P4 cell physiology analyzed by measuring glutathione (GSH) and non-protein thiol (cysteine) levels which were increased up to 130 and 48 %, respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) showed alteration in the expression levels of ftsZ, mutS, clpB, ef-tu, and dnaK genes in the presence of Cd(+2). Total protein profiles of E. coli P4 in the absence and presence of Cd(+2) were compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), which showed remarkable difference in the banding pattern. czcB gene, a component of czcCBA operon, was amplified from genomic DNA which suggested the chromosomal-borne Cd(+2) resistance in E. coli P4. Furthermore, it harbors smtAB gene which plays a significant role in Cd(+2) resistance.

Deciphering Multi-target Pharmacological Mechanism of Cucurbita pepo Seeds against Kidney Stones: Network Pharmacology and Molecular Docking Approach.

BACKGROUND: Urolithiasis is a prevalent condition with significant morbidity and economic implications. The economic burden associated with urolithiasis primarily stems from medical expenses. Previous literature suggests that herbal plants, including Cucurbita pepo, have lithotriptic capabilities. C. pepo is an annual, herbaceous, widely grown, and monoecious vegetative plant known for its antioxidants, fibers, and fatty acids. Recent studies on C. pepo seeds have shown therapeutic potential in reducing bladder stones and urodynamic illnesses, like kidney stones. However, the precise molecular and pharmacological mechanisms are unclear. OBJECTIVE: In this research, we employed network pharmacology and molecular docking to examine the active compounds and biological mechanisms of Cucurbita pepo against kidney stones. METHODS: Active constituents were obtained from previous studies and the IMPPAT database, with their targets predicted using Swiss target prediction. Kidney stone-associated genes were collected from DisGeNET and GeneCards. The active constituent-target-pathway network was constructed using Cytoscape, and the target protein-protein interaction network was generated using the STRING database. Gene enrichment analysis of C. pepo core targets was conducted using DAVID. Molecular docking was performed to identify potential kidney stone-fighting agents. RESULTS: The findings revealed that Cucurbita pepo contains 18 active components and has 192 potential gene targets, including AR, EGFR, ESR1, AKT1, MAPK3, SRC, and MTOR. Network analysis demonstrated that C. pepo seeds may prevent kidney stones by influencing disease-related signaling pathways. Molecular docking indicated that key kidney stone targets (mTOR, EGFR, AR, and ESR1) effectively bind with active constituents of C. pepo. CONCLUSION: These findings provide insight into the anti-kidney stone effects of Cucurbita pepo at a molecular level. In conclusion, this study contributes to understanding the potential of Cucurbita pepo in combating kidney stones and lays the foundation for further research.

Handwashing basins and healthcare associated infections: Bacterial diversity in biofilms on faucets and drains.

BACKGROUND: Increasingly, hospital handwashing basins have been identified as a source of healthcare-associated infections. Biofilms formed on the faucet and drains of handbasins can potentially harbour pathogenic microbes and promote the dissemination of antimicrobial resistance. However, little is known about the diversity of these biofilm communities and the routes of contamination. AIM: The aim of this paper was to use 16S rRNA gene amplicon sequencing to investigate the diversity of prokaryote communities present in faucet and drain biofilm samples taken from hospital and residential handbasins. FINDINGS: The biofilm prokaryotes communities were diverse, with high abundances of potentially corrosive, biofilm forming and pathogenic genera, including those that are not typically waterborne. The ß-diversity showed statistically significant differences in the variation of bacterial communities on the basis on building type (hospital vs residential p = 0.0415). However, there was no statistically significant clustering based on sampling site (faucet vs drain p = 0.46). When examining the ß-diversity between individual factors, there was a significant difference between drain biofilms of different buildings (hospital drain vs residential drain p = 0.0338). CONCLUSION: This study demonstrated that biofilms from hospital and residential handbasins contain complex and diverse microbial communities that differ significantly by building type. It also showed biofilms formed on the faucet and drain of a hospital's handbasins were not significantly different. Future research is needed to understand the potential mechanisms of transfer between drains and faucets of hospital handbasins. This information will inform improved infection control guidelines to control this underrecognized source of infections.

Increased flushing frequency of a model plumbing system initially promoted the formation of viable but non culturable cells but ultimately reduced the concentration of culturable and total Legionella DNA.

Legionella is the causative agent of Legionnaires' disease, and its prevalence in potable water is a significant public health issue. Water stagnation within buildings increases the risk of Legionella. However, there are limited studies investigating how stagnation arising through intermittent usage affects Legionella proliferation and the studies that are available do not consider viable but non culturable (VBNC) Legionella. This study used a model plumbing system to examine how intermittent water stagnation affects both VBNC and culturable Legionella. The model plumbing system contained a water tank supplying two biofilm reactors. The model was initially left stagnant for ≈5 months (147 days), after which one reactor was flushed daily, and the other weekly. Biofilm coupons, and water samples were collected for analysis at days 0, 14 and 28. These samples were analysed for culturable and VBNC Legionella, free-living amoebae, and heterotrophic bacteria. After 28 days, once-a-day flushing significantly (p < 0.001) reduced the amount of biofilm-associated culturable Legionella (1.5 log10 reduction) compared with weekly flushing. However, higher counts of biofilm-associated VBNC Legionella (1 log10 higher) were recovered from the reactor with once-a-day flushing compared with weekly flushing. Likewise, once-a-day flushing increased the population of biofilm-associated Vermamoeba vermiformis (approximately 3 log10 higher) compared with weekly flushing, which indicated a positive relationship between VBNC Legionella and V. vermiformis. This is the first study to investigate the influence of stagnation on VBNC Legionella under environmental conditions. Overall, this study showed that a reduction in water stagnation decreased culturable Legionella but not VBNC Legionella.

Uncovering chikungunya virus-encoded miRNAs and host-specific targeted genes associated with antiviral immune responses: an integrated bioinformatics approach.

Chikungunya virus (CHIKV) is a single-stranded RNA virus belonging to the genus Alphavirus and is responsible for causing Chikungunya fever, a type of arboviral fever. Despite extensive research, the pathogenic mechanism of CHIKV within host cells remains unclear. In this study, an in-silico approach was used to predict that CHIKV produces micro-RNAs that target host-specific genes associated with host cellular regulatory pathways. Putative micro-RNAs of CHIKV were predicted using the miRNAFold and Vmir RNA structure web servers, and secondary structure prediction was performed using RNAfold. Host-specific target genes were then predicted, and hub genes were identified using CytoHubba and module selection through MCODE. Functional annotations of hub genes revealed their association with various pathways, including osteoclast differentiation, neuroactive ligand-receptor interaction, and mRNA surveillance. We used the freely available dataset GSE49985 to determine the level of expression of host-specific target genes and found that two genes, F-box and leucine-rich repeat protein 16 (FBXL16) and retinoic acid receptor alpha (RARA), were down-regulated, while four genes, RNA binding protein with serine-rich domain 1 (RNPS1), RNA helicase and ATPase (UPF1), neuropeptide S receptor 1 (NPSR1), and vasoactive intestinal peptide receptor 1 (VIPR1), were up-regulated. These findings provide insight into novel miRNAs and hub genes associated with CHIKV infection and suggest potential targets for therapeutic intervention. Further experimental validation of these targets could lead to the development of effective treatments for CHIKV-mediated diseases.

Subtractive proteomics-based vaccine targets annotation and reverse vaccinology approaches to identify multiepitope vaccine against Plesiomonas shigelloides.

Plesiomonas shigelloides, an aquatic bacterium belonging to the Enterobacteriaceae family, is a frequent cause of gastroenteritis with diarrhea and gastrointestinal severe disease. Despite decades of research, discovering a licensed and globally accessible vaccine is still years away. Developing a putative vaccine that can combat the Plesiomonas shigelloides infection by boosting population immunity against P. shigelloides is direly needed. In the framework of the current study, the entire proteome of P. shigelloides was explored using subtractive genomics integrated with the immunoinformatics approach for designing an effective vaccine construct against P. shigelloides. The overall stability of the vaccine construct was evaluated using molecular docking, which demonstrated that MEV showed higher binding affinities with toll-like receptors (TLR4: 51.5 ± 10.3, TLR2: 60.5 ± 9.2) and MHC receptors(MHCI: 79.7 ± 11.2 kcal/mol, MHCII: 70.4 ± 23.7). Further, the therapeutic efficacy of the vaccine construct for generating an efficient immune response was evaluated by computational immunological simulation. Finally, computer-based cloning and improvement in codon composition without altering amino acid sequence led to the development of a proposed vaccine. In a nutshell, the findings of this study add to the existing knowledge about the pathogenesis of this infection. The schemed MEV can be a possible prophylactic agent for individuals infected with P. shigelloides. Nevertheless, further authentication is required to guarantee its safeness and immunogenic potential.

Detection and quantification of viable but non-culturable Legionella pneumophila from water samples using flow cytometry-cell sorting and quantitative PCR.

Legionella pneumophila is a waterborne pathogen and, as the causative agent of Legionnaires' disease, a significant public health concern. Exposure to environmental stresses, and disinfection treatments, promotes the formation of resistant and potentially infectious viable but non-culturable (VBNC) Legionella. The management of engineered water systems to prevent Legionnaires' disease is hindered by the presence of VBNC Legionella that cannot be detected using the standard culture (ISO11731:2017-05) and quantitative polymerase reaction (ISO/TS12869:2019) methods. This study describes a novel method to quantify VBNC Legionella from environmental water samples using a "viability based flow cytometry-cell sorting and qPCR" (VFC + qPCR) assay. This protocol was then validated by quantifying the VBNC Legionella genomic load from hospital water samples. The VBNC cells were unable to be cultured on Buffered Charcoal Yeast Extract (BCYE) agar; however, their viability was confirmed through their ATP activity and ability to infect amoeba hosts. Subsequently, an assessment of the ISO11731:2017-05 pre-treatment procedure demonstrated that acid or heat treatment cause underestimation of alive Legionella population. Our results showed that these pre-treatment procedures induce culturable cells to enter a VBNC state. This may explain the observed insensitivity and lack of reproducibility often observed with the Legionella culture method. This study represents the first time that flow cytometry-cell sorting in conjunction with a qPCR assay has been used as a rapid and direct method to quantify VBNC Legionella from environmental sources. This will significantly improve future research evaluating Legionella risk management approaches for the control of Legionnaires' disease.

The composition of planktonic prokaryotic communities in a hospital building water system depends on both incoming water and flow dynamics.

In recent years, the frequency of nosocomial infections has increased. Hospital water systems support the growth of microbes, especially opportunistic premise plumbing pathogens. In this study, planktonic prokaryotic communities present in water samples taken from hospital showers and hand basins, collected over three different sampling phases, were characterized by 16S rRNA gene amplicon sequencing. Significant differences in the abundance of various prokaryotic taxa were found through univariate and multivariate analysis. Overall, the prokaryotic communities of hospital water were taxonomically diverse and dominated by biofilm forming, corrosion causing, and potentially pathogenic bacteria. The phyla Proteobacteria, Actinobacteriota, Bacteroidota, Planctomycetota, Firmicutes, and Cyanobacteria made up 96% of the relative abundance. The α-diversity measurements of prokaryotic communities showed no difference in taxa evenness and richness based on sampling sites (shower or hand basins), sampling phases (months), and presence or absence of Vermamoeba vermiformis. However, ß-diversity measurements showed significant clustering of prokaryotic communities based on sampling phases, with the greatest difference observed between the samples collected in phase 1 vs phase 2/3. Importantly, significant difference was observed in prokaryotic communities based on flow dynamics of the incoming water. The Pielou's evenness diversity index revealed a significant difference (Kruskal Wallis, p < 0.05) and showed higher species richness in low flow regime (< 13 minutes water flushing per week and ≤ 765 flushing events per six months). Similarly, Bray-Curtis dissimilarity index found significant differences (PERMANOVA, p < 0.05) in the prokaryotic communities of low vs medium/high flow regimes. Furthermore, linear discriminant analysis effect size showed that several biofilm forming (e.g., Pseudomonadales), corrosion causing (e.g., Desulfobacterales), extremely environmental stress resistant (e.g., Deinococcales), and potentially pathogenic (e.g., Pseudomonas) bacterial taxa were in higher amounts under low flow regime conditions. This study demonstrated that a hospital building water system consists of a complex microbiome that is shaped by incoming water quality and the building flow dynamics arising through usage.

Stagnation arising through intermittent usage is associated with increased viable but non culturable Legionella and amoeba hosts in a hospital water system.

Hospital water systems are a significant source of Legionella, resulting in the potentially fatal Legionnaires' disease. One of the biggest challenges for Legionella management within these systems is that under unfavorable conditions Legionella transforms itself into a viable but non culturable (VBNC) state that cannot be detected using the standard methods. This study used a novel method (flow cytometry-cell sorting and qPCR [VFC+qPCR] assay) concurrently with the standard detection methods to examine the effect of temporary water stagnation, on Legionella spp. and microbial communities present in a hospital water system. Water samples were also analyzed for amoebae using culture and Vermamoeba vermiformis and Acanthamoeba specific qPCR. The water temperature, number and duration of water flow events for the hand basins and showers sampled was measured using the Enware Smart Flow® monitoring system. qPCR analysis demonstrated that 21.8% samples were positive for Legionella spp., 21% for L. pneumophila, 40.9% for V. vermiformis and 4.2% for Acanthamoeba. All samples that were Legionella spp. positive using qPCR (22%) were also positive for VBNC Legionella spp.; however, only 2.5% of samples were positive for culturable Legionella spp. 18.1% of the samples were positive for free-living amoebae (FLA) using culture. All samples positive for Legionella spp. were also positive for FLA. Samples with a high heterotrophic plate count (HPC ≥ 5 × 103 CFU/L) were also significantly associated with high concentrations of Legionella spp. DNA, VBNC Legionella spp./L. pneumophila (p < 0.01) and V. vermiformis (p < 0.05). Temporary water stagnation arising through intermittent usage (< 2 hours of usage per month) significantly (p < 0.01) increased the amount of Legionella spp. DNA, VBNC Legionella spp./L. pneumophila, and V. vermiformis; however, it did not significantly impact the HPC load. In contrast to stagnation, no relationship was observed between the microbes and water temperature. In conclusion, Legionella spp. (DNA and VBNC) was associated with V. vermiformis, heterotrophic bacteria, and stagnation occurring through intermittent usage. This is the first study to monitor VBNC Legionella spp. within a hospital water system. The high percentage of false negative Legionella spp. results provided by the culture method supports the use of either qPCR or VFC+qPCR to monitor Legionella spp. contamination within hospital water systems.

Molecular screening and characterization of Legionella pneumophila associated free-living amoebae in domestic and hospital water systems.

Free-living amoebae are ubiquitous in the environment and cause both opportunistic and non-opportunistic infections in humans. Some genera of amoebae are natural reservoirs of opportunistic plumbing pathogens, such as Legionella pneumophila. In this study, the presence of free-living amoebae and Legionella was investigated in 140 water and biofilm samples collected from Australian domestic (n = 68) and hospital water systems (n = 72). Each sample was screened in parallel using molecular and culture-based methods. Direct quantitative polymerase chain reaction (qPCR) assays showed that 41% samples were positive for Legionella, 33% for L. pneumophila, 11% for Acanthamoeba, and 55% for Vermamoeba vermiformis gene markers. Only 7% of samples contained culturable L. pneumophila serogroup (sg)1, L. pneumophila sg2-14, and non-pneumophila Legionella. In total, 69% of samples were positive for free-living amoebae using any method. Standard culturing found that 41% of the samples were positive for amoeba (either Acanthamoeba, Allovahlkampfia, Stenamoeba, or V. vermiformis). V. vermiformis showed the highest overall frequency of occurrence. Acanthamoeba and V. vermiformis isolates demonstrated high thermotolerance and osmotolerance and strong broad spectrum bacteriogenic activity against Gram-negative and Gram-positive bacteria. Importantly, all Legionella positive samples were also positive for amoeba, and this co-occurrence was statistically significant (p < 0.05). According to qPCR and fluorescence in situ hybridization, V. vermiformis and Allovahlkampfia harboured intracellular L. pneumophila. To our knowledge, this is the first time Allovahlkampfia and Stenamoeba have been demonstrated as hosts of L. pneumophila in potable water. These results demonstrate the importance of amoebae in engineered water systems, both as a pathogen and as a reservoir of Legionella. The high frequency of gymnamoebae detected in this study from Australian engineered water systems identifies an issue of significant public health concern. Future water management protocols should incorporate treatments strategies to control amoebae to reduce the risk to end users.

Genetic Diversity and Virulence Profiling of Multi-Drug Resistant Escherichia coli of Human, Animal, and Environmental Origins.

Rapid urbanization has increased human-animal interaction and consequently enhanced the chances to acquire zoonotic diseases. The current investigation is focused to uncover the genetic diversity of multidrug-resistant E. coli strains between different ecologies (i.e., humans, livestock, and environment) at the molecular level by employing antimicrobial resistance profiling, virulence genes profiling, and microbial typing approach using ERIC PCR. Based on multiple antibiotic resistance, overall, 19 antibiotic resistance patterns (R1-R19) were observed. Most of the strains (49/60) were detected to have the combinations of stx, eaeA, and hlyA genes and considered STEC/EPEC/EHEC. A total of 18 unique genetic profiles were identified based on ERIC-PCR fingerprints and most of the strains (13) belong to P1 whereas the least number of strains were showing profiles P7 and P8-P11 (one member each profile). The calculated values for Shannon index (H) for human, animal, and environment are 1.70, 1.82, and 1.78, respectively revealing the highest genetic diversity among the E. coli strains of animal origin. The study revealed that drug-resistant pathogenic E. coli strains could be transmitted bidirectionally among the environment, humans, and animals.

Development, Biological Characterization, and Immunological Evaluation of Virosome Vaccine against Newcastle Disease in Pakistan.

Newcastle disease (ND) is a highly fatal, infectious, viral disease, and despite immunization with live and inactivated vaccines, the disease is still endemic, causing heavy morbidity and mortality leading to huge economic losses to the poultry industry in Pakistan. Therefore, the present study was aimed for the first time in the country at using novel virosomal technology to develop the ND vaccine using an indigenous highly virulent strain of the virus. ND virosome was prepared using Triton X-100, and SM2 Bio-Beads were used to remove the detergent and reconstitute the viral membrane into virosome. Confirmation was done by transmission electron microscopy and protein analysis by SDS-PAGE. In vitro cell adhesion property was observed by incorporating green fluorescent protein (GFP), producing plasmid into virosome and in vitro cell culture assay. Sterility, safety, and stability of the vaccine were tested before in vivo evaluation of immunogenicity and challenge protection study in commercial broiler. The virosome vaccine was administered (30 µg/bird) at days 7 and 14 through the intranasal route in comparison with commercially available live and inactivated ND vaccines. Results revealed significantly high (p < 0.05) and clinically protective hemagglutination inhibition (HI) antibody titers at 7, 14, 21, and 28 days postimmunization with the virosome vaccine in comparison to the negative control. The GMTs were comparable to live and inactivated vaccines with nonsignificant (p > 0.05) differences throughout the experiment. Antibody levels increased in all vaccinated groups gradually from the 7th day and were maximum at 28th-day postvaccination. In the virosome-administered group, GMT was 83.18 and 77.62 at 21st and 28th-days postvaccination, respectively. Challenge revealed 100%, 90%, and 80% protection in virosome, live, and inactivated vaccinated groups, respectively. Under given experimental conditions, we can conclude that ND virosome vaccine prepared from the indigenous virus was found to be safe and immunogenic.

Molecular detection of extensively drug-resistant Salmonella Typhi and carbapenem-resistant pathogens in pediatric septicemia patients in Pakistan - a public health concern.

Aim: To determine the prevalence of multidrug (MDR) and extensively drug-resistant (XDR) pathogens from pediatric blood samples Methods: In total, 4543 children's blood samples were processed in the BacT/ALERT system. Confirmation of the isolates and MIC was determined in VITEK® 2 system. Molecular identification of blaIMP, blaVIM and blaOXA-48 was done by PCR. Results: Of 4543 blood cultures, 458 (10%) were positive for bacterial growth and Salmonella Typhi (415; 90%) remained the primary pathogens. Antibiogram revealed 208 (50.1%) and 137 (33%) were MDR and XDR S. Typhi, respectively. Klebsiella pneumoniae displayed 46% resistance to imipenem. One hundred twelve (81.7%) XDR Typhi were positive for blaCTXM, whereas 14 (66.6%) blaVIM were found in carbapenem-resistant bacteria. Conclusion: A high prevalence of MDR and XDR pathogens was found in peads blood culture.

The prospects of antimicrobial coated medical implants.

The implants are increasingly being a part of modern medicine in various surgical procedures for functional or cosmetic purposes. The progressive use of implants is associated with increased infectious complications and prevention of such infections always remains precedence in the clinical settings. The preventive approaches include the systemic administration of antimicrobial agents before and after the surgical procedures as well as the local application of antibiotics. The relevant literature and existing clinical practices have highlighted the role of antimicrobial coating approaches in the prevention of implants associated infections, although the applications of these strategies are not yet standardized, and the clinical efficacy is not much clear. The adequate data from the randomized control trials is challenging because of the unavailability of a large sample size although it is compulsory in this context to assess the clinical efficacy of preemptive practices. This review compares the efficacy of preventive approaches and the prospects of antimicrobial-coated implants in preventing implant-related infections.

Legionella pneumophila and Protozoan Hosts: Implications for the Control of Hospital and Potable Water Systems.

Legionella pneumophila is an opportunistic waterborne pathogen of public health concern. It is the causative agent of Legionnaires' disease (LD) and Pontiac fever and is ubiquitous in manufactured water systems, where protozoan hosts and complex microbial communities provide protection from disinfection procedures. This review collates the literature describing interactions between L. pneumophila and protozoan hosts in hospital and municipal potable water distribution systems. The effectiveness of currently available water disinfection protocols to control L. pneumophila and its protozoan hosts is explored. The studies identified in this systematic literature review demonstrated the failure of common disinfection procedures to achieve long term elimination of L. pneumophila and protozoan hosts from potable water. It has been demonstrated that protozoan hosts facilitate the intracellular replication and packaging of viable L. pneumophila in infectious vesicles; whereas, cyst-forming protozoans provide protection from prolonged environmental stress. Disinfection procedures and protozoan hosts also facilitate biogenesis of viable but non-culturable (VBNC) L. pneumophila which have been shown to be highly resistant to many water disinfection protocols. In conclusion, a better understanding of L. pneumophila-protozoan interactions and the structure of complex microbial biofilms is required for the improved management of L. pneumophila and the prevention of LD.