Sukhraj Kaur - Academia.edu (original) (raw)

Papers by Sukhraj Kaur

International Journal of Infectious Diseases, Apr 1, 2016

Background: Salmonella enterica ser. Typhi is the causative agent of the clinical condition calle... more Background: Salmonella enterica ser. Typhi is the causative agent of the clinical condition called typhoid fever that results after an incubation period of 10 to 15 days following infection. The main line of treatment of typhoid fever includes antibiotics such as fluoroquinolones and aminoglycosides; however, several studies have reported decreased susceptibilities of fluoroquinolones among Salmonella spp isolated from human infections. Thus, this necessitates the studies to explore alternative or adjunct therapeutic agents. Methods & Materials: In this study we isolated and screened the antimicrobial potential of 92 vaginal lactic acid bacteria from healthy women against S. enterica ser. Typhi MTCC 733 by using agar gel diffusion assay. Further, the susceptibility of S. enterica to various antibiotics and the synergistic activity of the culture supernatant (CS) of the isolate 12a along with antibiotics was determined by using Kirby Bauer disk diffusion and chequerboard titration methods, respectively. Results: The isolate no. 12a, identified as Enterococcus spp. by using physico-chemical characterisation showed broad spectrum antimicrobial activity against many Gram-negative pathogens including S. enterica MTCC733. The antimicrobial activity of the CS of 12a was proteinaceous in nature and lost its activity on treatment with pepsin, proteinase K and papain. The minimum inhibitory concentration of the CS was 2133 AU/ml and was stable over a wide pH range of 3-11. Further, the antimicrobial activity of the CS was lost at 100 • C; 1 hr treatment. The susceptibility of S. enterica to various antibiotics was determined and it showed reduced susceptibilities to many fluoroquinolones and aminoglycosides. Chequerboard titration assay showed that CS of 12a synergised antimicrobial activities of the antibiotics belonging to the classes fluoroquinolones, aminoglycosides and ␤-lactam against S. enterica. Conclusion: In conclusion, the study indicates the potential of the probiotic strains of enterococci as adjunct therapeutic agent against resistant forms of S. enterica.

BMC Microbiology

Background Oxidative stress is responsible for the onset of several chronic and degenerative dise... more Background Oxidative stress is responsible for the onset of several chronic and degenerative diseases. Exogenous supply of antioxidants is reported to neutralize the effects of oxidative stress. Several synthetic antioxidants suffer from various side effects which necessitates the exploration of antioxidant compounds from natural sources. Endophytic fungi residing in the plants are gaining the attention of researchers as a source of novel antioxidants. Majority of the research conducted so far on endophytic fungi has been restricted to the members of phylum ascomycota. Basidiomycota, inspite of their immense bioactive potential remain relatively unexploited. This study aimed to assess the ameliorative effects of an endophytic Schizophyllum commune (basidiomycetous fungus) against oxidative stress associated altered antioxidant levels, genotoxicity and cellular damage to different organs in bisphenol A exposed fresh water fish Channa punctatus. Results Good antioxidant and genoprotec...

Microbial Cell Factories, Dec 11, 2023

Background Gamma-aminobutyric acid (GABA) is a non-protein amino acid with neuroinhibitory, antid... more Background Gamma-aminobutyric acid (GABA) is a non-protein amino acid with neuroinhibitory, antidiabetic, and antihypertensive properties and is used as a drug for treating anxiety and depression. Some strains of lactobacilli are known to produce GABA and strengthen the gut barrier function which play an important role in ameliorating the effects caused by the pathogen on the gut barrier. The probiotic bacteria are also known to modulate the human fecal microbiota, however, the role of GABA-producing strains on the gut epithelium permeability and gut microbiota is not known. Results In this study, we report the production of high levels of GABA by potential probiotic bacterium Limosilactobacillus fermentum L18 for the first time. The kinetics of the production of GABA by L18 showed that the maximum production of GABA in the culture supernatant (CS) occurred at 24 h, whereas in fermented milk it took 48 h of fermentation. The effect of L18 on the restoration of lipopolysaccharide (LPS)-disrupted intestinal cell membrane permeability in Caco-2 monolayers showed that it significantly restored the transepithelial electrical resistance (TEER) values, by significantly increasing the levels of junction proteins, occludin and E-cadherin in L18 and LPS-treated Caco-2 cells as compared to only LPS-treated cells. The effect of GABA-secreting L18 on the metataxonome of human stool samples from healthy individuals was investigated by a batch fermentor that mimics the conditions of the human colon. Although, no differences were observed in the α and β diversities of the L18-treated and untreated samples at 24 h, the relative abundances of bacterial families Lactobacillaceae and Bifidobacteriaceae increased in the L18-treated group, but both decreased in the untreated groups. On the other hand, the relative abundance of Enterobacteriaceae decreased in the L18 samples but it increased in the untreated samples. Conclusion These results indicate that Li. fermentum L18 is a promising GABA-secreting strain that strengthens the gut epithelial barrier by increasing junction protein concentrations and positively modulating the gut microbiota. It has the potential to be used as a psychobiotic or for the production of functional foods for the management of anxiety-related illnesses.

Gut Pathogens

Salmonella enterica serotype Typhi causes chronic enteric fever known as typhoid. Prolonged treat... more Salmonella enterica serotype Typhi causes chronic enteric fever known as typhoid. Prolonged treatment regimen used for the treatment of typhoid and indiscriminate use of antibiotics has led to the emergence of resistant strains of S. enterica that has further increased the severity of the disease. Therefore, alternative therapeutic agents are urgently required. In this study, probiotic and enterocin-producing bacteria Enterococcus faecium Smr18 was compared for both its prophylactic and therapeutic efficacy in S. enterica infection mouse model. E. faecium Smr18 possessed high tolerance to bile salts and simulated gastric juice, as treatment for 3 and 2 h resulted in 0.5 and 0.23 log10 reduction in the colony forming units, respectively. It exhibited 70% auto aggregation after 24 h of incubation and formed strong biofilms at both pH 5 and 7. Oral administration of E. faecium in BALB/c mice infected with S. enterica significantly (p < 0.05) reduced the mortality of the infected mic...

AMB Express

The growing awareness about the adverse health effects of artificial synthetic preservatives has ... more The growing awareness about the adverse health effects of artificial synthetic preservatives has led to a rapid increase in the demand for safe food preservation techniques and bio preservatives. Thus, in this study, the biopreservatives efficacy of enterocin-producing Enterococcus faecium Smr18 and its enterocin, ESmr18 was evaluated against Salmonella enterica contamination in chicken samples. E. faecium Smr18 is susceptible to the antibiotics penicillin-G, ampicillin, vancomycin, and erythromycin, thereby indicating that it is a nonpathogenic strain. Further, the enterocin ESmr18 was purified and characterised as a 3.8 kDa peptide. It possessed broad spectrum antibacterial activity against both Gram-positive and Gram-negative pathogens including S. enterica serotypes Typhi and Typhimurium. Purified ESmr18 disrupted the cell membrane permeability of the target cell thereby causing rapid efflux of potassium ions from L. monocytogenes and S. enterica. Chicken samples inoculated with...

Journal of Applied and Natural Science, 2019

The dyeing of wool fabric using a natural dye extracted from Dacryodes macrophylla has been studi... more The dyeing of wool fabric using a natural dye extracted from Dacryodes macrophylla has been studied using both conventional as well as ultrasonic dyeing methods. Natural dye was extracted using water as solvent by Soxhlet extraction method. The extracted color was characterized by spectroscopic studies like UV/Visible and further tested for antimicrobial activity (against Vibrio cholerae (MTCC3906), Salmonella enterica serotype typhi (MTCC733), Shigella flexneri (MTCC1457), Escherichia coli (MTCC119), Listeria monocytogenes (MTCC657) and Staphylococcus aureus (MTCC 96). It was observed that the water extract of D. macrophylla showed antimicrobial activities against S. enterica. The effect of mordants on the dyeing outcome in terms of colour depth as well as fastness properties of the dyeing was investigated. It has been found that employing all the three techniques of dyeing i.e., conventional dyeing at 100 oC and 80 oC as well as ultrasonicated dyeings conducted at 80 oC, the mord...

Archiv der Pharmazie, 2009

A novel series of 14 new isonicotinyl hydrazide derivatives 2a-g, 3a-g containing a 4-thiazolidin... more A novel series of 14 new isonicotinyl hydrazide derivatives 2a-g, 3a-g containing a 4-thiazolidinone / 2-azetidinone nucleus were synthesized by reacting N'-substituted arylidene / heteroarylidene isonicotinyl hydrazide 1a-g with thioglycollic acid in the presence of dry benzene and with chloroacetyl chloride in the presence of triethylamine, respectively. Structures of all newly synthesized compounds were characterized on the basis of elemental analyses and spectral data (IR and (1)H-NMR). All the title compounds were tested for their in-vitro antimycobacterial activity against Mycobacterium tuberculosis H(37)Rv using Alamar-Blue susceptibility test, and the activity is expressed as the minimum inhibitory concentration (MIC) in microg/mL. Among the series, compounds 2b, 2g, 3b, and 3g displayed an encouraging antimycobacterial activity profile as compared to that of the reference drugs isoniazid / rifampicin.

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2009

A spectrophotometric method based on diazotization of aniline with triclosan has been developed f... more A spectrophotometric method based on diazotization of aniline with triclosan has been developed for the determination of triclosan in water samples. The diazotization process involves two steps: (1) reaction of aniline with sodium nitrite in an acidic medium to form diazonium ion and (2) reaction of diazonium ion with triclosan to form a yellowish-orange azo compound in an alkaline medium. The resulting yellowish-orange product has a maximum absorption at 352 nm which allows the determination of triclosan in aqueous solution in the linear concentration range of 0.1-3.0 μM with R 2 ¼ 0.998. The concentration of hydrochloric acid, sodium nitrite, and aniline was optimized for diazotization reaction to achieve good spectrophotometric determination of triclosan. The optimization of experimental conditions for spectrophotometric determination of triclosan in terms of concentration of sodium nitrite, hydrogen chloride and aniline was also carried out by using Box-Behnken design of response surface methodology and results obtained were in agreement with the experimentaly optimized values. The proposed method was then successfully applied for analyses of triclosan content in water samples.

Additional file 7 Supplementary Table 4: Antibiotic susceptibility profile of V. cholerae MTCC 3906

Additional file 4 Supplementary Table 1: Antibiotic susceptibility profile of S. enterica MTCC 733

Additional file 3 Supplementary Fig. 3. Agar gel overlay assay of SDS-PAGE gel containing purifie... more Additional file 3 Supplementary Fig. 3. Agar gel overlay assay of SDS-PAGE gel containing purified enterocin 12a band.

Additional file 1 Supplementary Fig. 1. Silver-stained SDS-PAGE gel showing the bands of partiall... more Additional file 1 Supplementary Fig. 1. Silver-stained SDS-PAGE gel showing the bands of partially purified enterocin 12a obtained after SP Sepharose cation-exchange chromatography.

The mouth harbors a diverse abundant and complex microbial community. This highly diverse microfl... more The mouth harbors a diverse abundant and complex microbial community. This highly diverse microflora inhabits various surfaces of normal mouth. Bacteria accumulate on both the hard and soft oral tissues in Biofilms. Bacteria occupy the ecological niche provided by both tooth surface and gingival epithelium. Oral bacteria include Streptococci, Staphylococci, Pediococci and Enterococci etc. Triclosan is organic compound which is antibacterial and antifungal agent present in some toothpaste which change the microflora. Saliva was sampled from Triclosan free and Triclosan containing toothpaste users. Different Medias used for isolation of microbes from samples and for characterization various physical and biochemical tests performed. From collected samples various diplococci, rod shaped and cocci shaped bacteria colonies isolated. Further characterization shows that these bacterial colonies belong to Pediococci, Leuconostoc, Enterococci and Streptococci. But its number is different in T...

Enterococcal species are Gram-positive lactic acid bacteria that are ubiquitously present in envi... more Enterococcal species are Gram-positive lactic acid bacteria that are ubiquitously present in environmental samples, plants, and gastrointestinal tracts of animals. As commensals they are known to benefit the host, but in recent years, they have earned dubious reputation as nosocomial pathogens. They are known to cause diseases like urinary tract infections, endocarditis, bacteremia, and intra-abdominal infections especially in immunocompromised patients that are subjected to prolonged antibiotic treatments. The various factors contributing to their status as nosocomial pathogens are their intrinsic and acquired resistance to various classes of antibiotics. They are known to persist on animate and inanimate surfaces for a long period of time which thus act as reservoirs for the spread of the infection in hospitals. Recent studies have shown that the nosocomial strains are genetically distinct from commensal Enterococcal strains. Thus, herein the various diseases caused by nosocomial ...

Immunomodulatory agents are potentially believed to play important roles in infectious, allergic,... more Immunomodulatory agents are potentially believed to play important roles in infectious, allergic, and autoimmune diseases. The probiotic bacteria such as lactobacilli have immunomodulatory properties and are generally regarded as safe. Thus, they can be used as adjuvants for the treatment of infectious and allergic/autoimmune diseases. The immunomodulatory properties of five lactobacilli species such as Lactobacillus casei, L. rhamnosus, L. paracasei, L. gasseri, and L. acidophilus have been well studied. This book chapter summarizes the various studies which have reported immunomodulation by Lactobacillus species. Further, the immunomodulatory molecules produced by lactobacilli have been discussed. The immunomodulatory effects of Lactobacillus species are strictly strain-specific and in some cases yielded contrasting results in different hosts. Thus, use of lactobacilli as immunomodulatory agent for therapeutic use should be strictly backed by human clinical trials. Further, some o...

International journal of applied research, 2016

New Journal of Chemistry, 2021

Probe BTNN undergoes a drastic upsurge (~146-fold, Φ = 69%) in fluorescence intensity (bright gre... more Probe BTNN undergoes a drastic upsurge (~146-fold, Φ = 69%) in fluorescence intensity (bright green, λem 530 nm) while moving from pH 7 to pH 2. MG-63 cells and E....

BMC Microbiology, 2021

Background Increase in the number of infections caused by Gram-negative bacteria in neutropenic c... more Background Increase in the number of infections caused by Gram-negative bacteria in neutropenic cancer patients has prompted the search for novel therapeutic agents having dual anticancer and antimicrobial properties. Bacteriocins are cationic proteins of prokaryotic origin that have emerged as one of the most promising alternative antimicrobial agents with applications as food preservatives and therapeutic agents. Apart from their antimicrobial activities, bacteriocins are also being explored for their anticancer potential. Results In this study, a broad-spectrum, cell membrane-permeabilizing enterocin with a molecular weight of 65 kDa was purified and characterized from the culture supernatant of vaginal Enterococcus faecium 12a. Enterocin 12a inhibited multidrug-resistant strains of various Gram-negative pathogens such as Salmonella enterica, Shigella flexneri, Vibrio cholerae, Escherichia coli and Gram-positive, Listeria monocytogenes, but had no activities against different str...

Microbial Cell Factories, 2020

Background An increasing rate of antibiotic resistance among Gram-negative bacterial pathogens ha... more Background An increasing rate of antibiotic resistance among Gram-negative bacterial pathogens has created an urgent need to discover novel therapeutic agents to combat infectious diseases. Use of bacteriocins as therapeutic agents has immense potential due to their high potency and mode of action different from that of conventional antibiotics. Results In this study, a novel bacteriocin E20c of molecular weight 6.5 kDa was purified and characterized from the probiotic strain of Enterococcus hirae. E20c had bactericidal activities against several multidrug resistant (MDR) Gram-negative bacterial pathogens. Flow cytometry and scanning electron microscopy studies showed that it killed the Salmonella enterica cells by forming ion-permeable channels in the cell membrane leading to enhanced cell membrane permeability. Further, checkerboard titrations showed that E20c had synergistic interaction with antibiotics such as ampicillin, penicillin, ceftriaxone, and ciprofloxacin against a cipr...

Molecular Biology Reports, 2019

Diabetes is considered as a major health concern worldwide and patients with diabetes are at high... more Diabetes is considered as a major health concern worldwide and patients with diabetes are at high risk for infectious diseases. Therefore, α-glucosidase inhibitors possessing antibacterial activity along with the ability to inhibit biofilms would be better therapeutic agents for diabetic patients. In the present study, two fractions (AF1 and AF2) possessing α-glucosidase inhibitory activity were purified from an endophytic fungus Alternaria destruens (AKL-3) isolated from Calotropis gigantea. These were evaluated for their antimicrobial and antibiofilm potential against human pathogens. AF1 exhibited broad spectrum antimicrobial activity against all the tested pathogens. It also significantly inhibited biofilm formation and dispersed the preformed biofilm at sub-optimal concentrations. AF2 possessed lesser activity as compared to AF1. The active compounds were purified using semi preparative HPLC. Some of the active compounds were identified to be phenolic in nature. The active fractions were also determined to be non-mutagenic and non-cytotoxic in safety analysis. The study highlights the role of endophytic fungi as sources of α-glucosidase inhibitors with antimicrobial potential which can have application in management of diabetes.