Antibacterial potential of sponge endosymbiont marine Enterobacter sp at Kavaratti Island, Lakshadweep archipelago

ObjectiveTo isolate antibacterial potential of sponge endosymbiotic bacteria from marine sponges at Lakshadweep archipelago. Also to identify the potent bacteria by 16s rDNA sequencing and determine the antibacterial activity against clinical pathogens by MIC.MethodsSponge samples was collected from sub-tidal habitats at Kavaratti Island and identified. The endosymbiotic bacteria were isolated and selected potential bacteria which show antibacterial activity in preliminary screening against clinical pathogens Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Salmonella typhi (S. typhi), Klebsiella pneumoniea (K. pneumoniea) and Streptococcus sp. by disc diffusion assay. The crude extracts of potential bacteria LB3 was tested against clinical pathogens by MIC. The LB3 strain was identified by 16s rDNA sequencing, 1 111 bp was submitted in NCBI (HQ589912) and constructed phylogenetic tree.ResultsSponge sample was identified as Dysidea granulosa (D. granulosa) and potential bacteria LB3 identified as Enterobacter sp TTAG. Preliminary screening of sponge isolates against clinical pathogens, LB3 strain was selected as potential producer of secondary metabolites and crude extract was implies on MIC of LB3 have confirmed with lowest concentration of 5.0 mg/mL in broth medium influence of crude extract on growth inhibitory activity after 5 h of incubation period and completed the inhibitory activity at 15 h.ConclusionsThe present study concluded that phylogenetic analysis of endosymbiotic bacteria Enterobacter sp from sponge D. granulosa of Lakshadweep islands showed significant antibacterial activity against clinical bacterial pathogens.     

Antagonistic properties of seagrass associated Streptomyces sp. RAUACT-1: A source for anthraquinone rich compound

ObjectiveTo identify the antibacterial potential of seagrass (Syringodium isoetifolium) associate microbes against bacterial pathogens.MethodsEumeration of microbial associates were analyzed with leaf and root samples of Syringodium isoetifolium. MIC and MBC were calculated for bacterial pathogens with microbial associates. Phylogenetic and GC-MS analysis were calculated for Actinomycetes sp. (Act01) which was the most potent.ResultsOf the isolated microbial associates phosphatase producing bacterial isolates were identified as maximum [(261.78±35.09) CFU×10⁴/g] counts in root sample. Of the selected microbial isolates Actinomycete sp (Act01) showed broad spectrum of antibacterial activity against antibiotic resistant and fish bacterial pathogens. Phylogenetic analysis of Act01 showed maximum identities (99%) with the Streptomyces sp. (GU5500072). The 16s rDNA secondary structure of Act01 showed the free energy values as ?366.3 kkal/mol. The GC-MS analysis Act01 showed maximum retention value with 23.742 RT and the corresponding chemical class was identified as 1, 4-dihydroxy-2-(3-hydroxybutyl)-9, 10-anthraquinone 9, 10-anthrac.ConclusionsIn conclusion, Streptomyces sp. (GU045544.1) from Syringodium isoetifolium could be used as potential antibacterial agent.     

Screening and study of antifungal activity of leaf litter actinomycetes isolated from Ternate Island,Indonesia

ObjectiveTo characterize abundance of leaf litter actinomycetes from Ternate Island and to assess the antifungal activity of actinomycetes isolates against Candida albicans, Saccharomyces cerevisiae (S. cerevisiae), and Aspergillus niger.MethodsActinomycetes were isolated from leaf litter of Durio species, Syzygium aromaticum, Piper betle, Myristica fragrans, or Pandanus species and unknown plants. Actinomycetes isolates were cultured in a liquid medium. Bioactive compounds were extracted and tested against fungal using Beury-Kirby method with modification. Minimum inhibitor concentration and cell leakages were conducted. Actinomycetes that produced the highest antifungal activity were indentified using molecular sequence data in 16S rRNA gene.ResultsOut of 50 selected isolates, two isolates MG-500-1-4 and SR-2-2 has highest activity against S. cerevisiae. Concentration of material containing nucleic acids, proteins, Ca⁺ and K⁺ ions and morphological observations indicated that extracts of MG-500-1-4 and SR-2-2 caused cell leakage and invagination of S. cerevisiae cells. Based on 16S rRNA gene identification, MG-500-1-4 and SR-2-2 isolates are similar to Streptomyces misakiensis and Streptomyces tricolor respectively.ConclusionsTernate Island contains interesting biodiversity of actinomycetes that has potential use in agriculture, fisheries, and human health to reduce problem of fungal pathogen.     

Antimicrobial constituents from three endophytic fungi

ObjectiveTo evaluate the antimicrobial potential of extracts of the endophytic fungi Plectophomella sp., Physalospora sp., and Crataegus monogyna (C. monogyna) and study the tentative identification of their active constituents.MethodsCrude extracts and isolated compounds were screened for antimicrobial activity using the agar well diffusion method. Four compounds were purified from three endophytic fungi using column chromatography and their structures have been assigned based on their ¹H and ¹³C nuclear magnetic resonance spectra.ResultsPlectophomella sp., Physalospora sp., and C. monogyna extracts showed promising antifungal, antibacterial and herbicidal properties. (-)-Mycorrhizin A was isolated from Plectophomella sp. while cytochalasins E and K were isolated from Physalospora sp. Similarly radicinin was purified from the endophytic fungus C. monogyna. The ethyl acetate extract of Plectophomella sp. showed significant antifungal activity towards Ustilago violacea (U. violacea) and Eurotium repens (E. repens) and significant antibacterial activity against Bacillus megaterium. Interestingly, the ethyl acetate extracts of Physalospora sp. and C. monogyna showed strong herbicidal and antifungal activities towards Chlorella fusca, U. violacea, E. repens, Mycotypha microspora (M. microspora), Fusarium oxysporum, Escherichia coli, and Bacillus megaterium. (-)-Mycorrhizin A showed significant antifungal activity towards U. violacea and E. repens. Cytochalasins E and K showed strong antifungal activity against E. repens and M. microspora especially towards fungal Mycotypha microspora. Similarly cytochalasins E and K showed good herbicidal activity towards Chlorella fusca. Radicinin showed strong antifungal activity against E. repens and M. microspora.ConclusionsAntimicrobial activities demonstrated by the extracts of the endophytic fungi Plectophomella sp., Physalospora sp., and C. monogyna and four isolated compounds clearly demonstrate that these fungi extracts and active compounds present a great potential use in the food, cosmetic and pharmaceutical industries.     

Surveillance of multidrug resistance of 10 enteropathogens in a teaching hospital and in vitro efficacy of 25 ethnomedicinal plants used by an Indian aborigine

ObjectiveTo have an antibiogram of hospital acquired (HA) and community acquired (CA) enteropathogens against 16 antibiotics to assess the infection dynamics for plausible help to the antimicrobial stewardship. To check extracts of 25 lesser-known plants used by an Indian aborigine, for antimicrobial efficacy in vitro and as complementary and alternate medicines against resistant pathogens.MethodsTen strains of enteric bacteria (Enterobacter aerogenes, Escherichia coli, Klebsiella sp., Salmonella paratyphi, S. typhi, Shigella boydii, S. dysenteriae, S. flexneri, S. sonnei and Vibrio cholerae) were isolated from clinical samples in 6 months and their antibiotic sensitivity was assessed by the disc-diffusion method. Concentrated aqueous and ethanolic extracts of leaves and barks of plants were used for monitoring their antibacterial potencies, by the agar-well diffusion method.ResultsIsolated bacterial strains were invariably multidrug resistant (MDR). E. coli was the most frequently isolated organism from HA and CA samples, followed next by Klebsiella sp. From the surveillance, it was evident that the distribution of MDR strains of each was more in HA than CA isolates. Aqueous and ethanolic extracts of Aegle marmelos, Azadirachta indica, Cassia fistula, Holarrhena antidysenterica, Salvadora persica and Terminalia arjuna were highly effective against the all isolated enteropathogenic strains. From the preliminary phytochemical analysis, it was confirmed that both extracts of A. indica, T. arjuna and T. alata contained all the detected phytochemicals (alkaloids, glycosides, terpenoids, reducing sugars, saponins, tannins, flavonoids and steroids), which plausibly attributed to their significant antibacterial activity.ConclusionsPhytoextracts were highly effective against the all enteropathogenic bacterial isolates, in vitro. These 25 plants could be used further for the isolation of pure compounds for use as complementary medicines.     

In vitro antibacterial potential of metal oxide nanoparticles against antibiotic resistant bacterial pathogens

ObjectiveTo investigate the antibacterial potential of 5 different metal oxide nanoparticles against antibiotic resistant bacterial pathogens viz., Pseudomonas aeruginosa, Klebsiella sp. Streptococcus pneumoniae, Staphylococcus aureus and Streptococcus sp.MethodsThe antibacterial activity of the five different nanoparticles was assessed by well diffusion method. Different concentrations of the nanoparticles were analyzed by MIC and MBC techniques. Finally the potential MgO nanoparticle was also subjected for the time kill assay method.ResultsThe results reveal that, the MgO nanoparticle showed maximum sensitivity [(16.00±0.53) mm dia] against Streptococcus pneumoniae and showed minimum sensitivity against Klebsiella sp. [(9.00±0.31) mm dia]. None of the nanoparticles showed sensitivity against the Streptococcus sp. The MIC result reveals that, the MgO nanoparticle showed maximum inhibition at a concentration of 10 μ g against Streptococcus pneumoniae. Moreover, the time kill assay reveals that, the bacterial growth was inhibited from the 2nd h onwards at a concentration of 10μ g.ConclusionsIt is concluded from the present findings that, the MgO nanoparticle could be used as an alternative antibacterial agent after completing successful in vivo trials.     

Isolation and identification of MDR–Mycobacterium tuberculosis and screening of partially characterised antimycobacterial compounds from chosen marine micro algae

ObjectiveTo isolate the multiple drug resistance (MDR) Mycobacterium tuberculosis (M. tuberculosis) and to screen for the bioactive compounds extracted from marine microalgae.MethodsSixty seven collected samples that were confirmed by 16S rDNA analysis as positive with M. tuberculosis infection were subjected to sensitivity test against commercially used front line and second line drugs by absolute concentration method using LJ slants. Seven bacterial isolates numbered I-78, I-101, I-127, I-173, I-202, I-262, I-327 showed resistant for more than 3 drugs were considered as MDR M. tuberculosis. Thus the percentage of 10.4 were recorded MDRTB. Fifteen marine micro algal extracts were screened for antimycobacterial activity and partial characterization of the active principles was done.ResultsThe percentage contribution of marine micro algal species on the extraction of antimycobacterials indicated Isochrysis galbana (I. galbana) contain rich bioactive compounds and accounted for 60% inhibition of the total isolates. The percentage contribution of solvents on the extraction of antimicrobials from I. galbana showed that the methanol, chloroform, n-Butanol showed maximum of extraction. The purified eluted compounds (R_f 0.43) from TLC plate were chromatographed by gas chromatography. The eluted sterol compounds showed 13 unsaturated sterols with 3 major sterols.ConclusionsThe present study indicates the presence of unsaturated fatty acids may have the effect on MDR M. tuberculosis, indicating a potential natural alternative to antibiotics.     

The effect of extracts of Selaginella involvens and Selaginella inaequalifolia leaves on poultry pathogens

ObjectiveTo investigate the antimicrobial activity of some commonly available herbs against poultry pathogens such as Escherichia coli (E. coli) and Pseudomonas species isolated from poultry litter.MethodsThe extracts of Selaginella involvens and Selaginella inaequalifolia were tested against E. coli and Pseudomonas isolated from poultry litter by the agar diffusion method.ResultsResults indicated that different plant extracts showed inhibitory effects against E. coli (8-13 mm) and Pseudomonas (6.5-13 mm). The four different extracts of Selaginella involvens and Selaginella inaequalifolia showed similar levels of antimicrobial activity on E. coli.ConclusionsThe antimicrobial activities of all the four plant extracts are comparable and their potential as alternatives in the treatment of infections by these microorganisms were present in the poultry litter. Susceptibility testing is conduced on isolates using drugs selected on the basis of their importance to human medicine and use in poultry production.     

Roles for mannitol and mannitol dehydrogenase in active oxygen-mediated plant defense

Reactive oxygen species (ROS) are both signal molecules and direct participants in plant defense against pathogens. Many fungi synthesize mannitol, a potent quencher of ROS, and there is growing evidence that at least some phytopathogenic fungi use mannitol to suppress ROS-mediated plant defenses. Here we show induction of mannitol production and secretion in the phytopathogenic fungus Alternaria alternata in the presence of host-plant extracts. Conversely, we show that the catabolic enzyme mannitol dehydrogenase is induced in a non-mannitol-producing plant in response to both fungal infection and specific inducers of plant defense responses. This provides a mechanism whereby the plant can counteract fungal suppression of ROS-mediated defenses by catabolizing mannitol of fungal origin.     

Antimicrobial activity of Hibiscus sabdariffa extract against uropathogenic strains isolated from recurrent urinary tract infections

ObjectiveTo report the antimicrobial effect and biofilm forming capacity of the uropathogenic strains that have been isolated from recurrent urinary tract infections (UTIs) in the presence of Hibiscus sabdariffa (H. sabdariffa) extract.MethodsSix Escherichia coli and two Klebsiella pneumoniae isolates were collected from patients with recurrent UTIs. The susceptibility of bacterial isolates to H. sabdariffa extracts were tested by determining their minimum inhibitory concentrations (MICs), and minimum bactericidal concentration (MBC) by using the broth microdilution method in accordance to Clinical and Laboratory Standards Institute guidelines. Time-kill curves were plotted against the eight isolates based on the MIC results. The biofilm forming capacity of the isolates were evaluated using the microtiter plate assay. Detection of biofilms was done using the crystal violet staining method.ResultsVarious levels of the extracts MIC were observed against all the uropathogenic isolates. MIC values ranged from 0.5 to 4 mg/mL, and MBC values ranged from 8 to 64 mg/mL. Both the time-kill experiment and MBC-MIC ratio demonstrated that the extracts' effect was in general, bacteriostatic. The biofilm capacity inhibition assay results showed that extracts inhibited biofilm production of all the isolates. The level of biofilm inhibition however, had varied among the bacterial strains and ranged from 8%–60% reduction in optical density.ConclusionsThe results of the study support the effective potential of H. sabdariffa extract to prevent recurrent UTIs and to emphasize the significance of the plant extract, in order to approach it as a potential antimicrobial agent.     

Evaluation of antimicrobial study in in vitro application of Clerodendrum infortunatum Linn.

ObjectiveTo evaluate the antimicrobial potency of ethanol and chloroform extracts of root, leaf and stem of Clerodendrum infortunatum (Verbenaceae) and to explore a scientific data as this plant was randomly use in traditional medicine to cure common ailments such as intestinal disorder, diarrhea, tuberculosis and respiratory problems, etc.MethodsThe in vitro application was carried out by using disc diffusion, micro broth dilution and serial dilution techniques against clinically important life threatening organisms.ResultsAll the extracts showed significant inhibitory activity over the bacteria and fungus comparable to the standard drug tetracycline and fluconazole. The maximum average diameter zone of inhibition was recorded to bacterial strains against Bacillus megaterium, Salmonella typhi, Klebsiella pneumoniae and to fungi against Aspergillus niger and Candida albicans. The minimum inhibitory concentration values of ethanol leaf extract were determined 64 μg/mL to Bacillus megaterium, Salmonella typhi and Klebsiella pneumoniae; 128 μg/mL to Staphylococcus aureus, Streptococcus-β–haemolyticus and Escherichia coli.ConclusionsThe findings evidently appear promising antibacterial and antifungal properties of Clerodendrum infortunatum against antagonistic pathogens. Leaf possesses quite potent activity than root and stem specially leaf extract>root extract>stem extract. This study serves as basis for further research to lead compounds to be isolated so that it may be as a template for the implications of these results for bioactivity and drug discovery potential of herbal products.     

Resistance among Gram-negative ESKAPE pathogens isolated from hospitalized patients with intra-abdominal and urinary tract infections in Latin American countries: SMART 2013–2015

Gram-negative ESKAPE pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are important etiologic agents of nosocomial infection that are frequently resistant to broad-spectrum antimicrobial agents. Gram-negative ESKAPE pathogens were collected from hospitalized patients in 11 Latin American countries from 2013 to 2015 as part of the Study for Monitoring Antimicrobial Resistance Trends (SMART) global surveillance program. In total, 2113 isolates from intra-abdominal infections (IAI) and 970 isolates from urinary tract infections (UTI) were tested against antimicrobial agents using standardized CLSI broth microdilution methodology. Of the agents tested, amikacin demonstrated the highest rates of susceptibility (%) for K. pneumoniae (92.2, 92.3), Enterobacter spp. (97.5, 92.1), and P. aeruginosa (85.3, 75.2) isolates from both IAI and UTI, respectively. Ertapenem (68.5, 62.6) and imipenem (79.2, 75.9) showed substantially higher rates of susceptibility (%) than other β-lactams, including piperacillin-tazobactam (35.9, 37.4) against ESBL-positive isolates of K. pneumoniae from IAI and UTI, respectively. Rates of susceptibility to all agents tested against A. baumannii were ≤30.9%. Gram-negative ESKAPE pathogens isolated from Latin America demonstrated compromised in vitro susceptibility to commonly prescribed broad-spectrum, parenteral antimicrobial agents. Continued surveillance is warranted. New antimicrobial agents with potent activity against Gram-negative ESKAPE pathogens are urgently needed.     

Antibacterial activities of some Indian traditional plant extracts

ObjectiveTo evaluate the in vitro antibacterial activity of various solvent extracts of South Indian traditional medicinal plants Ocimum sanctum, Ocimum gratissimum, Aegle marmelos, and Adhatoda vasica leaves against clinical pathogens of human origin.MethodsThe antimicrobial activity of different solvents crude extract of four medicinal plants used in traditional Indian medicine was tested by disc diffusion method against five bacterial pathogens: Escherichia coli, Staphylococcus aureus, Salmonella typhi, Salmonella paratyphi and klebsiella pneumoniae.. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was determined for evaluating the potential plant extract.ResultsThe antibacterial results showed methanol extracts (0.4 g/ml) of Ocimum gratissimum and Ocimum sanctum showed maximum zone of inhibition (30 mm and 25.5 mm, respectively) against Salmonella typhi. MIC was tested at various concentrations from 0.625 mg/ml to 0.039 mg/ml for all the plant extracts. At the lowest concentration (0.039mg/ml) tested, methanol extracts of Ocimum gratissimum showed higher MIC against Salmonella typhi and Salmonella paratyphi where as the methanolic extracts of Ocimum gratissimum showed potent activity against Staphylococcus aureus at 0.078 mg/ml. Methanol extract (0.4 g/ml) of Aegle marmelos showed significant inhibitory activity of 22.5mm and MIC value of 0.156.mg/ml against E. coli strain. The Klebsiella spp was the most resistant strain of all and various concentrations Adhatoda vasica extract showed less activity against the tested pathogens.ConclusionsThe present screening result demonstrated that the Indian traditional medicinal plants Ocimum sanctum, Ocimum gratissimum, Aegle marmelos methanol leaf extract has potent antibacterial activity and the studied plants may be new source for novel antibacterial compound discovery for treating drugs resistant human pathogens.     

Adhesion and cellsurface properties of wild species of spore formers against enteric pathogens

ObjectiveTo investigate the adhesion potential and cell surface properties against enteric pathogens Salmonella typhi, Salmonella para typhi A and Vibrio cholera.MethodsAdhesion potentials of spore and vegetative phase were studied separately for the isolates. Hydrophobic nature was measured on the basis of affinity towards the xylene. Autoaggregation and coaggregation were studied on the basis of clumping of cells. In vitro adhesion studies were done on mucous which were prepared from infant child faeces. Biofilm production of superior adhesive isolate was confirmed by SEM analysis.ResultsSpore and vegetative phases of isolates possessed a different rate of adhesion potentials on intestinal mucous, which indicated that cell surface properties were involved in adhesion process. Spores showed a higher hydrophobicity than their vegetative cells which remained less or non hydrophobic. Vegetative phases showed capabilities for autoaggregation and coaggregation. Spores were found to be more adhesive on intestinal mucous than vegetative phase. Among enteric pathogens Vibrio cholera registered higher adhesion potentials with supporting cell surface properties. Among the five sporeforming isolates, isolate BM-3 possess superior adhesion than enteric pathogens and also exhibited biofilm formation which enhances colonization potential.ConclusionsSpore and vegetative cell phases shows differences in adhesion potentials. Cell surface properties and adhesion studies reveals that isolate BM-3 can be selected as superior isolate which is capable for biofilm production. In short, isolate BM-3 possesses an enhanced adhesion potential than enteric pathogens towards intestinal mucous which is a desirable probiotic character.     

Antimicrobial chemical constituents from endophytic fungus Phoma sp.

Objective:To evaluate the antiniicrobial polenlial of different extracts of the endophytic fungus Phoma sp.and the tentative identification of their active constituents.Methods:The extract and compounds were screened for antimicrobial activity using the Agar Well Diffusion Method.Four compounds were purified using column chromatography and tlieir structures were assigned using～1H and～(13)C NMR spectra,DEPT,2D COSY,HMQC and HMBC experiments.Results:The ethyl acetate fraction of Phoma sp.showed good antifungal,antibacterial,and algicidal properties.One new dihydrofuran derivative,named phomafuranol(1),together with tliree known compounds,phomalacton(2),(3R)-5-hydroxymellein(3)and emodin(4)were isolated from the ethyl acetate fraction of Phoma sp.Preliminary studies indicated that phomalacton(2)displayed strong antibacterial,good antifungal and antialgal activities.Similarly(3R)-5-hydroxymellein(3)and emodin(4)showed good antifungal,antibacterial and algicidal properties.Conclusions:Antimicrobial activities of the ethyl acetate fraction of the endophytic fungus Phoma sp.and isolated compounds clearly demonstrate that Phoma sp.and its active compounds represent a great potential for the food,cosmetic and pharmaceutical industries.     

Isolation and molecular characterization of bioactive secondary metabolites from Callyspongia spp. associated fungi

ObjectiveTo isolate and characterize the bioactive secondary metabolite from Callyspongia spp. associated fungi.MethodsIn vitro antibacterial screening of fungi associated with Callyspongia species, collected from south east coast of India, against selected clinical isolates of bacteria were conducted in this study. The extracts showing good antimicrobial activity were subjected to further analysis to identify the active constituents sponge associated fungi (both biomass and filtrate) with five different solvents. The compound responsible for bioactivity was characterized using Fouvier-transform infrared (FT-IR) and gas chromatography-mass spectrometry (GC-MS) instrumental analysis to identify the functional group and compound. The molecular characterization of the elite fungal strains were done by isolating their genomic DNA and amplify the internal transcribed spacer (ITS) region of 5.8 sr RNA using specific ITS primer. The novelty of the strain was proved by BlastN analysis against non-redundant (NR) database and hence was submitted to GenBank.ResultsActive compound was Desmethylnomifensine confirmed by GC-MS and the potent fungi was Aspergillus flavus GU815344.ConclusionsThe isolate exhibits a marked antagonistic activity against potential bacterial pathogens thus illuminating the advanced researches in this decade to focus on clinical pharmacology to identify novel therapeutic targets. The present study depicts a promising scenario to focus on Aspergillus flavus derived compounds which can be easily scaled up for large biomass production and stable formulation as a drug.     

In vitro antioxidant activity and total phenolic content of endophytic fungi isolated from Eugenia jambolana Lam.

ObjectiveTo elucidate the antioxidant activity and total phenolic content (TPC) of ethyl acetate extracts of endophytic fungi isolated from Eugenia jambolana by three different antioxidant assays.MethodsTwenty one different endophytic fungal extracts were screened for presence of various phytochemicals, TPC and in vitro antioxidant activity. TPC was tested by Folin-Ciocalteau reagent based assay. DPPH free radical scavenging, hydrogen peroxide scavenging and reducing power assays were used to evaluate the antioxidant activity.ResultsAlkaloids, phenols, flavonoids, saponins, and terpenes were the main phytochemicals presents in all 21 endophytes. A significant positive correlation was found between antioxidant activity and TPC in fungal extracts. There is 36% endophytic extracts having high phenolic content exhibited potent antioxidant activity. Chaetomium sp., Aspergillus sp., Aspergillus peyronelii and Aspergillus niger strain showed the highest antioxidant activity ranging from 50% to 80% having 58 mg/g to 60 mg/g GAE total phenolics. Ascorbic acid used as a standard showed 90% reducing potential.ConclusionsThe results reveal that metabolites produced by endophytic fungi isolated from Eugenia jambolana can be a potential source of novel natural antioxidant compounds.     

Antimicrobial activity of Lactobacillus against microbial flora of cervicovaginal infections

ObjectiveTo assess the probiotic nature of Lactobacillus in preventing cervical pathogens by studying the effectiveness of antimicrobial activity against vaginal pathogens.MethodsLactobacilli were isolated from healthy vaginal swabs on selective media and different pathogenic bacteria were isolated by using different selective media. The Lactobacillus strains were tested for the production of hydrogen peroxide and antimicrobial compounds along with probiotic properties.ResultsOf the 10 isolated Lactobacillus strains, strain 1, 3 and 6 are high hydrogen peroxide producers and the rest were low producers. Results of pH and amines tests indicated that pH increased with fishy odour in the vaginal fluids of cervicovaginal infection patients when compared with vaginal fluids of healthy persons. The isolates were found to be facultative anaerobic, Gram-positive, non-spore-forming, non-capsule forming and catalase-negative bacilli. The results of antimicrobial activity of compounds indicated that 280 and 140 μg/mL was the minimum concentration to inhibit the growth of both pathogens and test organisms respectively.ConclusionsThe results demonstrated that Lactobacillus producing antimicrobial compounds inhibits the growth of cervical pathogens, revealing that the hypothesis of preventing vaginal infection by administering probiotic organisms has a great appeal to patients, which colonize the vagina to help, restore and maintain healthy vagina.     

In vitro antibacterial activity of the metal oxide nanoparticles against urinary tract infectious bacterial pathogens

ObjectiveTo investigate the antibacterial properties of the five metal oxide nanoparticles viz., Al₂O₃, Fe₂O₃, CeO₂, ZrO₂ and MgO against urinary tract infectious pathogens viz., Pseudomonas sp., Enterobacter sp., Klebsiella sp., Escherichia coli (E. coli), Proteus morganii (P. morganii) and Staphylococcus aureus (S. aureus).MethodsThe antibacterial activity of the five different nanoparticles was assessed by well diffusion method. Different concentrations of the nanoparticles were analyzed by minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) techniques. Finally, the potential nanoparticle Al₂O₃ which showed maximum antibacterial sensitivity was also subjected for the time kill assay method.ResultsAmong the nanoparticles, Al₂O₃ nanoparticle showed maximum sensitivity (16.00±0.21) mm against E. coli. None of the nanoparticles showed activity against Pseudomonas sp. The MIC results also revealed that, the Al₂O₃ nanoparticle showed maximum inhibition at the concentration of 5 μg/mL against E. coli, followed by 10 μg/mL against Klebsiella sp. and P. morganii, respectively. Moreover, the time kill assay revealed that, the bacterial growth was maximum inhibited at the concentration of 5 μg/mL from the 2nd h.ConclusionsIt can be concluded from the present findings that, the Al₂O₃ nanoparticle can be used as an alternative antibacterial agent for the urinary bacterial diseases after completing successful clinical trials.     

Multiple evolutionary origins of the fungus causing Panama disease of banana: Concordant evidence from nuclear and mitochondrial gene genealogies

Panama disease of banana, caused by the fungus Fusarium oxysporum f. sp. cubense, is a serious constraint both to the commercial production of banana and cultivation for subsistence agriculture. Previous work has indicated that F. oxysporum f. sp. cubense consists of several clonal lineages that may be genetically distant. In this study we tested whether lineages of the Panama disease pathogen have a monophyletic origin by comparing DNA sequences of nuclear and mitochondrial genes. DNA sequences were obtained for translation elongation factor 1α and the mitochondrial small subunit ribosomal RNA genes for F. oxysporum strains from banana, pathogenic strains from other hosts and putatively nonpathogenic isolates of F. oxysporum. Cladograms for the two genes were highly concordant and a partition-homogeneity test indicated the two datasets could be combined. The tree inferred from the combined dataset resolved five lineages corresponding to “F. oxysporum f. sp. cubense” with a large dichotomy between two taxa represented by strains most commonly isolated from bananas with Panama disease. The results also demonstrate that the latter two taxa have significantly different chromosome numbers. F. oxysporum isolates collected as nonpathogenic or pathogenic to other hosts that have very similar or identical elongation factor 1α and mitochondrial small subunit genotypes as banana pathogens were shown to cause little or no disease on banana. Taken together, these results indicate Panama disease of banana is caused by fungi with independent evolutionary origins.