Decoding the role of oxidative stress resistance and alternative carbon substrate assimilation in the mature biofilm growth mode of Candida glabrata.

BACKGROUND: Biofilm formation is viewed as a vital mechanism in C. glabrata pathogenesis. Although, it plays a significant role in virulence but transcriptomic architecture and metabolic pathways governing the biofilm growth mode of C. glabrata remain elusive. The present study intended to investigate the genes implicated in biofilm growth phase of C. glabrata through global transcriptomic approach. RESULTS: Functional analysis of Differentially expressed genes (DEGs) using gene ontology and pathways analysis revealed that upregulated genes are involved in the glyoxylate cycle, carbon-carbon lyase activity, pre-autophagosomal structure membrane and vacuolar parts whereas, down- regulated genes appear to be associated with glycolysis, ribonucleoside biosynthetic process, ribosomal and translation process in the biofilm growth condition. The RNA-Seq expression of eight selected DEGs (CgICL1, CgMLS1, CgPEP1, and CgNTH1, CgERG9, CgERG11, CgTEF3, and CgCOF1) was performed with quantitative real-time PCR (RT-qPCR). The gene expression profile of selected DEGs with RT-qPCR displayed a similar pattern of expression as observed in RNA-Seq. Phenotype screening of mutant strains generated for genes CgPCK1 and CgPEP1, showed that Cgpck1∆ failed to grow on alternative carbon substrate (Glycerol, Ethanol, Oleic acid) and similarly, Cgpep1∆ unable to grow on YPD medium supplemented with hydrogen peroxide. Our results suggest that in the absence of glucose, C. glabrata assimilate glycerol, oleic acid and generate acetyl coenzyme-A (acetyl-CoA) which is a central and connecting metabolite between catabolic and anabolic pathways (glyoxylate and gluconeogenesis) to produce glucose and fulfil energy requirements. CONCLUSIONS: The study was executed using various approaches (transcriptomics, functional genomics and gene deletion) and it revealed that metabolic plasticity of C. glabrata (NCCPF-100,037) in biofilm stage modulates its virulence and survival ability to counter the stress and may promote its transition from commensal to opportunistic pathogen. The observations deduced from the present study along with future work on characterization of the proteins involved in this intricate process may prove to be beneficial for designing novel antifungal strategies.

Mapping of audiometric analysis with microbiological findings in patients with chronic suppurative otitis media (CSOM): a neglected clinical manifestation.

Otitis media (OM) is an umbrella term for a number of conditions associated with middle ear inflammation. Chronic suppurative otitis media (CSOM), a type of OM, is characterized by long-term middle ear infection with perforated ear drum and otorrhea. The most common outcome associated with it is acquired hearing impairment in infected individuals which ultimately affects their cognitive and scholastic developments. Clinically, CSOM is thought to be a sequel of re-occurring episodes of Acute otitis media (AOM). Pseudomonas aeruginosa and Staphylococcus aureus are found to be the predominant pathogenic isolates in these patients. However, with the emergence of antibiotic resistance amongst these pathogens, the adequate evaluation and treatment of this condition has become more problematic. The disease has also been recognized as one of the neglected tropical clinical manifestations with high prevalence in school-age children, especially in poor or underprivileged countries. Moreover, untreated cases have further worsened the situation by contributing to various life-threatening complications. Thus, effective treatment and surgical strategies, as well as strengthening of hearing care algorithms along with the discovery of novel animal models for advanced clinical research, can jointly help to fight this disease. In this regard, mapping of the audiological analysis with microbiological findings in CSOM patients may help elucidate the frequency that favors growth of specific pathogens. Knowledge about this potential correlation can then support timely detection of the infection, which is perceived as one of the emerging approaches for its management. In addition to these strategies, creating a true sense of awareness among people can also help mitigate this pathological condition by facilitating early identification, prevention, and treatment. This review discusses the incidence, pathogenesis, investigations, complications, and available treatment modalities associated with CSOM.

Potential of a novel flagellin epitope as a broad-spectrum vaccine candidate against enteric fever.

Relentless emergence of antibiotic resistant Salmonella strains, coupled with the drawbacks associated with currently available vaccines against enteric fever, warrants an urgent need to look for new vaccine candidates. Out of the multiple virulence factors harbored by Salmonella, flagella are regarded as one of the most important targets of innate as well as adaptive immune response. Individual Salmonella serotypes alternate between expression of two different antigenic forms encoded by fliC and fljB genes, respectively thereby employing this as a strategy to escape the host immune response. In the present study, using various immunoinformatic approaches, a flagellin epitope, present in both antigenic forms of typhoidal Salmonellae has been targeted. Following B-cell epitope and B-cell derived T-cell epitope prediction and interaction studies with major histocompatibility complexes using molecular docking, a peptide epitope was selected. Further, it was screened for its presence in majority of typhoidal serovars along with other useful attributes, in silico. Thereafter, safety studies were performed with the synthesized peptide. Subsequently, immunization studies were carried out using S. Typhi as well as S. Paratyphi A induced murine peritonitis model. Active immunization with peptide-BSA conjugate resulted in 75% and 80% mice survival following lethal challenge with S. Typhi and S. Paratyphi A respectively, along with a significant IgG antibody titer, thereby highlighting its immunogenic potential. Reduced bacterial burden in vital organs along with improved histoarchitecture and cytokine levels further substantiated the protective efficacy of the proposed candidate. Passive immunization studies with the candidate verified the protective efficacy of the generated antibodies against lethal challenge of bacteria in mice. Given the endemic nature of enteric fever and the antigenic variability observed in Salmonella serotypes, present study highlights the importance of using a vaccine candidate, which, along with generating a strong immune response, also exhibits a broad coverage against both, S. Typhi as well as S. Paratyphi A strains.

Contribution of typhoid toxin in the pathogenesis of Salmonella Typhi.

To persist and establish infection, Salmonella utilizes a battery of different virulence determinants at every stage of infection. Typhoid toxin, a newly identified toxin in Salmonella enterica serovar Typhi is recognized as one of the virulence factors that has been linked with Salmonella pathogenesis. In this study, we have further investigated the role of typhoid toxin in the symptomatology of typhoid fever through in-vivo and ex-vivo studies. In mice, administration of cloned and purified typhoid toxin induces similar symptoms observed during typhoid fever such as fever, weight loss with a decrease in peripheral leucocyte count along with an increase in levels of pro-inflammatory cytokines (Il-6, TNF-α). Results of DNA analysis, fluorescence microscopy and flow cytometry of typhoid toxin-treated macrophages (ex-vivo) altogether revealed the CdtB (subunit of typhoid toxin) mediated DNA damage that led to the apoptosis of cells. Furthermore, to validate CdtB's catalytic role, macrophages were treated with typhoid toxin preincubated with anti-CdtB antibodies (generated in mice). Re-assessment of macrophage DNA by gel electrophoresis and flow cytometry analysis indicated a significant decrease in DNA damage and cells undergoing apoptosis, respectively. Moreover, a significant reduction in in-vitro DNase activity of CdtB protein was also observed on preincubating holotoxin with anti-CdtB antibodies. In total, this study highlights the role of typhoid toxin in inducing typhoid fever-like symptomatology, which may be executed through the toxin's catalytic subunit CdtB.

Heavy metal-induced selection and proliferation of antibiotic resistance: A review.

Antibiotic resistance is recognized as a global threat to public health. The selection and evolution of antibiotic resistance in clinical pathogens were believed to be majorly driven by the imprudent use of antibiotics. However, concerns regarding the same, through selection pressure by a multitude of other antimicrobial agents, such as heavy metals, are also growing. Heavy metal contamination co-selects antibiotic and metal resistance through numerous mechanisms, such as co-resistance and cross-resistance. Here, we have reviewed the role of heavy metals as antimicrobial resistance driving agents and the underlying concept and mechanisms of co-selection, while also highlighting the scarcity of studies explicitly inspecting the process of co-selection in clinical settings. Prospective strategies to manage heavy metal-induced antibiotic resistance have also been deliberated, underlining the need to find specific inhibitors so that alternate medicinal combinations can be added to the existing therapeutic armamentarium.

Microbially-derived cocktail of carbohydrases as an anti-biofouling agents: a 'green approach'.

Enzymes, also known as biocatalysts, display vital properties like high substrate specificity, an eco-friendly nature, low energy inputs, and cost-effectiveness. Among their numerous known applications, enzymes that can target biofilms or their components are increasingly being investigated for their anti-biofouling action, particularly in healthcare, food manufacturing units and environmental applications. Enzymes can target biofilms at different levels like during the attachment of microorganisms, formation of exopolymeric substances (EPS), and their disruption thereafter. In this regard, a consortium of carbohydrases that can target heterogeneous polysaccharides present in the EPS matrix may provide an effective alternative to conventional chemical anti-biofouling methods. Further, for complete annihilation of biofilms, enzymes can be used alone or in conjunction with other antimicrobial agents. Enzymes hold the promise to replace the conventional methods with greener, more economical, and more efficient alternatives. The present article explores the potential and future perspectives of using carbohydrases as effective anti-biofilm agents.

Possible Contribution of Alternative Transcript Isoforms in Mature Biofilm Growth Phase of Candida glabrata.

Expression of genome-wide alternative transcript isoforms and differential transcript isoform usage in different biological conditions (isoform switching) are responsible for the varied proteomic functional diversity in higher eukaryotic organisms. However, these mechanisms have not been studied in Candida glabrata, which is a potent eukaryotic opportunistic pathogen. Biofilm formation is an important virulence factor of C. glabrata that withstands antifungal drug stress and overcomes the host-immune response. Here, we present the genome-wide differential transcript isoform expression (DTE) and differential transcript isoform usage (DTU) in a mature biofilm growth phase of C. glabrata (clinical isolate; NCCPF 100,037) using the RNA sequencing approach. The DTE analysis generated 7837 transcript isoforms from the C. glabrata genome (5293 genes in total), and revealed that transcript isoforms generated from 292 genes showed significant DTU in the mature biofilm cells. Gene ontology, pathway analysis and protein-protein interactions of significant transcript isoforms, further substantiated that their specific expression and differential usage is required for transitioning the planktonic cells to biofilm in C. glabrata. The present study reported the possible role of expression of alternative transcript isoforms and differential transcript isoform usage in the mature biofilms of C. glabrata. The observation derived from the study may prove to be beneficial for making future antifungal therapeutic strategies. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-022-01036-7.

Diet, Gut Microbiota and COVID-19.

Worldwide, millions of individuals have been affected by the prevailing SARS-CoV-2. Therefore, a robust immune system remains indispensable, as an immunocompromised host status has proven to be fatal. In the absence of any specific antiviral drug/vaccine, COVID-19 related drug repurposing along with various other non-pharmacological measures coupled with lockdown have been employed to combat this infection. In this context, a plant based rich fiber diet, which happens to be consumed by a majority of the Indian population, appears to be advantageous, as it replenishes the host gut microbiota with beneficial microbes thereby leading to a symbiotic association conferring various health benefits to the host including enhanced immunity. Further, implementation of the lockdown which has proven to be a good non-pharmacological measure, seems to have resulted in consumption of home cooked healthy diet, thereby enriching the beneficial microflora in the gut, which might have resulted in better prognosis of COVID-19 patients in India in comparison to that observed in the western countries.

Genomic analysis of Indian strains of Salmonella enterica subsp. enterica serovar Typhi indicates novel genetic repertoire for pathogenicity and adaptations.

In the era of emerging antibiotic resistance, Salmonella enterica subsp. enterica serovar Typhi the causative agent of typhoid, is a threat for healthcare systems in developing countries especially India, where the disease is highly endemic. Genetic diversity among different strains may be the cause of variable severity of disease in different regions of the world. To explore this genetic diversity, genome annotation by rapid annotation using subsystem technology (RAST) was carried out for genomes of four Salmonella Typhi strains from two distinct areas available in the public domain. Two clinical strains were from India (P-stx-12 and E02-1180) and the other two strains considered as reference strains were from the endemic regions of Papua New Guinea (UJ308A and UJ816A). We report that Indian clinical strains possess several similar genes responsible for virulence and pathogenicity as those present in the reference strains. Interestingly, Indian clinical strains also possess 34 additional potential virulence genes that are absent in the reference strains, suggesting the more dreadful nature of Indian clinical strains as compared to those causing endemic typhoid. Indian strains contained genes coding for; Colicin V and bacteriocin production; multidrug resistance efflux pumps; ABC transporters; Type III and Type VI secretion systems, siderophore aerobactin, pathogenicity islands and Vi polysaccharide biosynthesis and transport. These unique genes are also reported in the genomes of other six clinical strains of India analyzed through RAST and IslandViewer 4 for validation purpose. This study highlights the presence of potential genes as molecular targets to overcome the future endemic outbreaks in India.

Peptides as adjuvants for ampicillin and oxacillin against methicillin-resistant Staphylococcus aureus (MRSA).

Fast emerging antibiotic resistance in pathogens requires special attention for strengthening the reservoir of antimicrobial compounds. In view of this, several peptides with known antimicrobial activities have been reported to enhance the efficacy of antibiotics against multidrug resistant (MDR) pathogens. In the present study, potential of peptides having distinct mechanism of action, if any, was evaluated to improve the efficacy of conventional antibiotics against methicillin-resistant S. aureus (MRSA). After primary screening of six peptides, two peptides namely T3 and T4 showing very high minimum inhibitory concentrations (MICs) were selected to assess their role in altering the MICs of antibiotics to which the pathogen was resistant. In the presence of the peptides, the MICs of the antibiotics were found to be reduced as per the fractional inhibitory concentration indices (FICI) and time kill assay. These observations prompted us to look for their mechanism of action. The effect of peptides on the morphology of pathogen by field emission scanning electron microscopy (FE-SEM) revealed no damage to the cells at the sub-inhibitory concentrations of the peptide which correlated well with the higher MIC of the peptide, indicating no direct impact on the pathogen. However, dielectric spectroscopy, confocal microscopy and flow cytometry confirmed the interaction and localization of peptides with the bacterial membrane. The peptides were also found to inhibit efflux of ethidium bromide which is the substrate for many proteins involved in efflux system. Therefore, it is speculated that the peptides after interacting with the membrane of the pathogen might have resulted in the inhibition of the efflux of antibiotics thereby reducing their effective concentrations. The study thus suggests that peptides with no antimicrobial activity of their own, can also enhance the efficacy of the antibiotics by interacting with the pathogen thereby, acting as adjuvants for the antibiotics.

Tackling Salmonella Persister Cells by Antibiotic-Nisin Combination via Mannitol.

Bacterial persisters (defined as dormant, non-dividing cells with globally reduced metabolism) are the major cause of recurrent infections. As they neither grow nor die in presence of antibiotics, it is difficult to eradicate these cells using antibiotics, even at higher concentrations. Reports of metabolites (which help in waking up of these inactive cells) enabled eradication of bacterial persistence by aminoglycosides, suggest the new potential strategy to improve antibiotic therapy. Here we propose, mannitol enabled elimination of Salmonella persister cells by the nisin-antibiotic combination. For this, persister cells were developed and characterized for their typical properties such as non-replicative state and metabolic dormancy. Different carbon sources viz. glucose, glycerol, and mannitol were used, each as an adjunct to ampicillin for the eradication of persister cells. The maximum (but not complete) killing was observed with mannitol-ampicillin, out of all the combinations used. However, significant elimination (about 78%) could be observed, when nisin (an antimicrobial peptide) was used with ampicillin in presence of mannitol, which might have mediated the transfer of antibiotic-nisin combination at the same time when the cells tried to grab the carbon molecule. Further, the effectiveness of the trio was confirmed by flow cytometry. Overall, our findings highlight the potential of this trio-combination for developing it as an option for tackling Salmonella persister cells.

Remediation of intramacrophageal Shigella dysenteriae type 1 by probiotic lactobacilli isolated from human infants' stool samples.

BACKGROUND & OBJECTIVES: Shigella dysenteriae is one of the most virulent pathogens causing bacillary dysentery and is responsible for high mortality in infants. To reduce the load of antibiotic therapy for treating shigellosis, this study was carried out to assess the ex vivo effect of novel probiotic lactobacilli, isolated from infant's stool samples, on killing S. dysenteriae type 1 residing in the rat macrophages. METHODS: Stool samples from infants were collected, processed for the isolation of lactobacilli and screened for the probiotic attributes (acid tolerance, bile tolerance, ability to adhere intestinal cells and anti-S. dysenteriae activity). The effect of cell-free supernatant of lactobacilli on Shigella- infected macrophages in terms of phagocytic ability, extent of lipid peroxidation, nitrite, superoxide dismutase and glutathione levels was evaluated. RESULTS: Based on the probiotic attributes, three lactobacilli were isolated from the stool samples of infants. Using classical and molecular tools, these isolates were identified as Lactobacillus pentosus, L. Paraplantarum and L. rhamnosus. All the three lactobacilli had the ability to kill intramacrophage S. dysentriae type 1. The anti-Shigella activity of the probiotic lactobacilli was attributed to increased antioxidative ability and decreased free radical production by the infected macrophages. INTERPRETATION & CONCLUSIONS: Probiotic cocktail of L. pentosus, L. paraplantarum and L. rhamnosus showed ex vivo killing of S. dysenteriae residing inside the rat macrophages significantly. This cocktail has the potential to be used as a natural alternative for treating S. dysenteriae infection, especially in infants, however, further studies need to be done to confirm these finding in vivo.

Management of Staphylococcus Mediated Systemic Infection by Enhancing the Resurging Activity of Co-trimoxazole in Presence of Cryptdin-2.

Resurgence of sensitivity of the antibiotics, to which the pathogen had developed resistance in the past, requires special attention for strengthening the reservoir of antimicrobial compounds. Reports in the recent past have suggested that co-trimoxazole (COT) has regained its activity against methicillin resistant Staphylococcus aureus (MRSA). The present study exploited the use of COT in the presence of an antimicrobial peptide (AMP), cryptdin-2 (a murine Paneth cell alpha defensin), in order to reduce the selective pressure of the antibiotic on the pathogen. In vitro antibacterial activity and in vivo efficacy of the combination was ascertained against MRSA induced systemic infection using a murine model. Observations of the present study might help in restoring the regained activity of conventional antibiotics, such as COT, when used in combination with novel antimicrobial molecules like AMPs. This might prove as a viable strategy to eliminate the chances of re-occurrence of resistance due to their multi-prong targeting and synergistically combating infections caused by these resistant pathogens.

Synergism in dual functionality of cryptdin-2 in conjunction with antibiotics against Salmonella.

BACKGROUND & OBJECTIVES: The emergence of multidrug-resistant Salmonella over the last two decades poses a major health risk. In this context, antimicrobial peptides have found a strategic place in the therapeutic armamentarium. Previously, we found that cryptdin-2 has the potential to augment the activity of conventional second- and third-generation anti-Salmonella antibiotics as evident by in vitro assays. In continuation to this, the present study was designed to evaluate the in vivo synergistic effects, if any, of cryptdin-2 in combination with ciprofloxacin and ceftriaxone against murine salmonellosis. METHODS: Scanning electron microscopy (SEM) studies along with in vivo synergistic studies were performed using cryptdin- 2 and antibiotic combinations. In addition, peroxidative liver damage, levels of nitric oxide (NO) and antioxidant enzymes along with tumour necrosis factor-alpha (TNF-α) levels were also measured. RESULTS: The SEM results revealed marked changes on the outer membrane of the bacterial cells treated with various combinations. Both the tested combinations demonstrated synergistic in vivo potency against S. Typhimurium as evident by reduction in the number of Salmonellae in the liver, spleen and intestine. Analysis of peroxidative liver damage, levels of NO and antioxidant enzymes along with TNF-α and nuclear factor-kappa B levels revealed that the tested combinations restored their levels to near normal. The most potent combination was found to be that of cryptdin-2 and ciprofloxacin in terms of direct killing and immunomodulatory potential. INTERPRETATION & CONCLUSIONS: These findings suggest that cryptdin-2 may act in conjunction with conventional antibiotics indicating the possibility of developing these combinations as additional therapeutic agents to combat Salmonella infections.

Effect of nisin and doxorubicin on DMBA-induced skin carcinogenesis--a possible adjunct therapy.

In view of the emergence of multidrug-resistant cancer cells, there is a need for therapeutic alternatives. Keeping this in mind, the present study was aimed at evaluating the synergism between nisin (an antimicrobial peptide) and doxorubicin (DOX) against DMBA-induced skin carcinogenesis. The possible tumoricidal activity of the combination was evaluated in terms of animal bioassay observations, changes in hisotological architecture of skin tissues, in situ apoptosis assay (TUNEL assay) and in terms of oxidant and antioxidant status of the skin tissues. In vivo additive effect of the combination was evidenced by larger decreases in mean tumour burden and tumour volume in mice treated with the combination than those treated with the drugs alone. Histological observations indicated that nisin-DOX therapy causes chromatin condensation and marginalisation of nuclear material in skin tissues of treated mice which correlated well with the results of TUNEL assay wherein a marked increase in the rate of apoptosis was revealed in tissues treated with the combination. A slightly increased oxidative stress in response to the adjunct therapy as compared to dox-alone-treated group was revealed by levels of lipid peroxidation (LPO) and nitrite generation in skin tissue-treated mice. An almost similar marginal enhancement in superoxide dismutase levels corresponding with a decrease in catalase activity could also be observed in nisin + DOX-treated groups as compared to nisin and dox-alone-treated groups. These results point towards the possible use of nisin as an adjunct to doxorubicin may help in developing alternate strategies to combat currently developing drug resistance in cancer cells.

Nisin/ß-lactam adjunct therapy against Salmonella enterica serovar Typhimurium: a mechanistic approach.

OBJECTIVES: Multidrug resistance exhibited by Salmonella strains has proved to be a big hurdle in the development of an effective anti-Salmonella therapy. In this context, we had previously demonstrated strong synergism of nisin/ceftriaxone and nisin/cefotaxime combinations against Salmonella enterica serovar Typhimurium. However, the mechanism remained unexplored. The present study was therefore planned in order to evaluate the underlying mechanisms responsible for the synergistic effect of nisin in combination with these ß-lactam antibiotics against serovar Typhimurium. METHODS: A membrane permeabilization assay along with pulse labelling studies were performed to confirm the ability of the combinations to permeabilize the bacterial membrane and to verify their effects on macromolecule synthesis. Additionally, analysis of peroxidative liver damage was performed and levels of nitric oxide, antioxidant enzymes, tumour necrosis factor-α and nuclear factor-κB were also measured. RESULTS: 1-N-phenylnapthylamine (NPN) uptake assay results confirmed a permeabilization-dependent mechanism, as NPN was taken up by treated cells in a time- and concentration-dependent manner, indicating that the combination influenced membrane permeability. Likewise, dose- and time-dependent inhibition of DNA, RNA and protein synthesis in the presence of both the combinations was observed. Interestingly, synergistic results inferred from in vivo assays confirmed the immuno-modulatory effects of the combinations in the treated mice. CONCLUSIONS: Nisin/ceftriaxone and nisin/cefotaxime combinations exert their antibacterial activity against Salmonella by multiple modes of action that involve membrane permeabilization, inhibition of DNA, RNA and protein synthesis and direct immuno-modulatory activity.

Revisiting eukaryotic anti-infective biotherapeutics.

Emerging drug resistance has forced the scientific community to revisit the observational data documented in the folklore and come up with novel and effective alternatives. Candidates from eukaryotic origin including herbal products and antimicrobial peptides are finding a strategic place in the therapeutic armamentarium against infectious diseases. These agents have recently gained interest owing to their versatile applications. Present review encompasses the use of these alternative strategies in their native or designer form, alone or in conjunction with antibiotics, as possible remedial measures. Further to this, the limitations or the possible concerns associated with these options are also discussed at length.

Efficiency of double layered microencapsulated probiotic to modulate proinflammatory molecular markers for the management of alcoholic liver disease.

Alcohol-related disorders are one of the challenging current health problems with medical, social, and economic consequences. Endotoxemia, oxidative stress, and release of a variety of inflammatory molecules are established mediators in alcoholic liver injury (ALD). Probiotics like L. plantarum though were reported to attenuate ALD, their in vivo health benefits are limited by their survival and sustenance in the adverse gut conditions. Therefore, to enhance their in vivo performance, chitosan coated alginate beads entrapping L. plantarum were prepared, characterized, and evaluated for their efficacy against ALD in rats. Following chronic alcohol exposure, rats developed endotoxemia, showed enhanced levels of liver enzyme markers, NF-κB levels, and increased cytokines such as TNF- α and IL12/p40 subunit, and reflected significant histological changes in the intestine and liver. However, cosupplementation with double layered microencapsulated probiotic significantly (P < 0.05) reduced the levels of endotoxemia, serum transaminases, NF-κB, and cytokines complemented with restoration of normal histoarchitecture of the intestine and liver. It is being documented here for the first time that the probiotics have the potential to inhibit IL-12/p40 subunit which is a recently explored potential marker for developing novel therapeutic agents. This study reveals that microencapsulation of probiotics may offer a biopharmacological basis for effective management of ALD.

Efficacy of cryptdin-2 as an adjunct to antibiotics from various generations against salmonella.

Emerging drug resistance in Salmonella coupled with the recent poor success rate of antibiotic discovery programs of the pharmaceutical industry is a cause for significant concern. It has forced the scientific community to look for alternative new classes of antimicrobial compounds. In this context, combinations of antimicrobial peptides (AMPs) and conventional antibiotics have gained interest owing to their versatile applications. The present study was therefore planned to evaluate the synergistic effects, if any, of cryptdin-2, a mouse Paneth cell alpha-defensin, in combination with four different antibiotics i.e. ciprofloxacin, ceftriaxone, cefotaxime and chloramphenicol, which are conventionally used against Salmonella. Minimum bactericidal concentrations of the selected antimicrobial agents were determined by micro and macro broth dilution assays. In-vitro synergy between the agents was evaluated by fractional bactericidal concentration index (checkerboard test) and time-kill assay. Cryptdin-2-ciprofloxacin, cryptdin-2-ceftriaxone and cryptdin-2-cefotaxime combinations were found synergistic as evident by in vitro assays. This synergism provides an additional therapeutic choice by allowing the use of conventional antibiotics in conjunction with AMPs against MDR Salmonella.

Changes in the electrical properties at an early stage of mouse liver carcinogenesis.

The present investigation reports the changes in the electrical properties of hepatic tissue in the frequency range of 100 Hz to 5 MHz at an early stage of liver carcinogenesis using the four-pin electrode method. The hepatocarcinogenesis model was developed by intraperitoneal injection of N-nitrosodiethylamine (NDEA) to male Balb/c mice. Histopathological assessment revealed high-grade dysplasia in the liver of NDEA-treated animals. The ultrastructural investigations indicated the presence of large and clumped cells with inconspicuous cell boundaries. The treatment resulted in significant changes in the dielectric properties of the tissues. A decrease in tissue conductivity along with an increase in relative permittivity was observed. The biophysical changes correlated well with histoarchitectural and morphological changes. The alterations in architectural arrangement and membrane structure of cells may be responsible for the observed changes in the dielectric properties.