Current Issue : January - March Volume : 2014 Issue Number : 1 Articles : 7 Articles
Background: Recent studies have shown that mammalian milk represents a continuous supply of commensal\r\nbacteria, including enterococci. The objectives of this study were to evaluate the presence of enterococci in milk of\r\ndifferent species and to screen them for several genetic and phenotypic traits of clinical significance among\r\nenterococci.\r\nResults: Samples were obtained from, at least, nine porcine, canine, ovine, feline and human healthy hosts.\r\nEnterococci could be isolated, at a concentration of 1.00 Ã?â?? 102 -1.16 Ã?â?? 103 CFU/ml, from all the porcine samples and,\r\nalso from 85, 50, 25 and 25% of the human, canine, feline and ovine ones, respectively. They were identified as\r\nEnterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Enterococcus casseliflavus and Enterococcus durans.\r\nAmong the 120 initial enterococcal isolates, 36 were selected on the basis of their different PFGE profiles and further\r\ncharacterized. MLST analysis revealed a wide diversity of STs among the E. faecalis and E. faecium strains, including\r\nsome frequently associated to hospital infections and novel STs. All the E. faecalis strains possessed some of the\r\npotential virulence determinants (cad, ccf, cob, cpd, efaAfs, agg2, gelE, cylA, espfs) assayed while the E. faecium ones only\r\nharboured the efaAfm gene. All the tested strains were susceptible to tigecycline, linezolid and vancomycin, and\r\nproduced tyramine. Their susceptibility to the rest of the antimicrobials and their ability to produce other biogenic\r\namines varied depending on the strain. Enterococci strains isolated from porcine samples showed the widest spectrum\r\nof antibiotic resistance.\r\nConclusions: Enterococci isolated from milk of different mammals showed a great genetic diversity. The wide\r\ndistribution of virulence genes and/or antibiotic resistance among the E. faecalis and E. faecium isolates indicates that\r\nthey can constitute a reservoir of such traits and a risk to animal and human health....
Recently, natural plants have received much attention as sources of biological active substances. In the present study\r\nwe investigated different extracts of Hedychium coronarium rhizomes for their in-vitro antimicrobial activity. In-vitro\r\nantimicrobial activity was evaluated for methanolic, chloroform and hexane extracts against five bacterial and two fungal strains\r\nby using cylinder plate assay. All the tested extracts of Hedychium coronarium showed significant zone of inhibition against\r\ntested bacterial and fungal strains in a dose dependent manner. All the extracts showed good zone of inhibition at a doses of 250\r\nand 500 ?g/ml. The highest zone of inhibition was shown by chloroform extract against Klebsiella pneumonia at the dose of 500\r\n?g/ml. All extracts exhibited antimicrobial activity in a dose dependent manner but relatively low activity when compared to\r\nthat of standard rifampicin. The activity may be higher if larger dose levels were employed....
Methanolic and aqueous extracts of Cressa Cretica were screened for their antibacterial and antifungal activities. The extracts were tested against 6 different species of human pathogenic bacteria and 4 fungal strains. Most of the extracts were devoid of antifungal and antibacterial activities, the aqueous extract of grass Cressa Cretica obtained by very good activity when compare to methanol extract, which showed strong inhibitory activity against the Gram-positive and Gram-negative bacteria. This study suggests that aqueous extracts of leaves of Cressa Cretica obtained by infusion can be used in the treatment of skin diseases caused by dermatophytes....
Background: Antimicrobial peptides have been the focus of much research over the last decade because of their\r\neffectiveness and broad-spectrum activity against microbial pathogens. These peptides also participate in inflammation\r\nand the innate host defense system by modulating the immune function that promotes immune cell adhesion and\r\nmigration as well as the respiratory burst, which makes them even more attractive as therapeutic agents. This has led\r\nto the synthesis of various antimicrobial peptides, including KSL-W (KKVVFWVKFK-NH2), for potential clinical use. Because\r\nthis peptide displays antimicrobial activity against bacteria, we sought to determine its antifungal effect on C. albicans.\r\nGrowth, hyphal form, biofilm formation, and degradation were thus examined along with EFG1, NRG1, EAP1, HWP1,\r\nand SAP 2-4-5-6 gene expression by quantitative RT-PCR.\r\nResults: This study demonstrates that KSL-W markedly reduced C. albicans growth at both early and late incubation\r\ntimes. The significant effect of KSL-W on C. albicans growth was observed beginning at 10 �µg/ml after 5 h of contact by\r\nreducing C. albicans transition and at 25 �µg/ml by completely inhibiting C. albicans transition. Cultured C. albicans under\r\nbiofilm-inducing conditions revealed that both KSL-W and amphotericin B significantly decreased biofilm formation at 2,\r\n4, and 6 days of culture. KSL-W also disrupted mature C. albicans biofilms. The effect of KSL-W on C. albicans growth,\r\ntransition, and biofilm formation/disruption may thus occur through gene modulation, as the expression of various\r\ngenes involved in C. albicans growth, transition and biofilm formation were all downregulated when C. albicans was\r\ntreated with KSL-W. The effect was greater when C. albicans was cultured under hyphae-inducing conditions.\r\nConclusions: These data provide new insight into the efficacy of KSL-W against C. albicans and its potential use as an\r\nantifungal therapy....
Aflatoxin and ochratoxin A were produced from Aspergillus parasiticus and Aspergillus ochraceus respectively and\r\nquantified using TLC. The toxins were mixed with broiler feed to attain required concentration. Four diets for broilers were\r\nprepared, diet 1-basal diet (control), diet 2-basal diet + aflatoxin (1 ppm) + ochratoxin (2 ppm), diet 3-basal diet+ aflatoxin (1\r\nppm) + ochratoxin (2 ppm) + activated charcoal (0.4%), diet 4- basal diet + aflatoxin (1 ppm) + ochratoxin (2 ppm) + activated\r\ncharcoal (0.4%) + yeast culture (0.2%). These four diets were fed to 4 groups of day old broiler chicks with four replicates of\r\neight birds in each replicate, in a completely randomized design for six weeks. Degenerative changes in Liver, kidney and\r\ngerminal centre depletion in spleen, cystic space in bursa of fabricius and disruption of cardiac muscle fibres were observed on\r\nhistopathology in birds fed with aflatoxin and ochratoxin supporting the biochemical study. Activated charcoal (0.4%) showed\r\nonly partial protective effect on combined toxicity in broilers. These results indicate that aflatoxin and ochratoxin in the diet\r\ncaused damage to vital organs. Though the combination of activated charcoal and yeast culture was more effective in\r\ncounteracting the combined toxicity of aflatoxin and ochratoxin compared to the activated charcoal alone, they also could not\r\ncompletely ameliorate the combined toxicity in broilers....
Mucus in fishes plays a major role in protecting against external bacterial, parasitic and fungal infestation. Hence, the\r\nmucus acts as a significant defence barrier and plays a key role in innate immunity. The research emphasizes on the\r\nantimicrobial property and haemolytic efficacy of the epidermal mucus of the striped dwarf catfish, Mystus vittatus collected\r\nfrom the Vellar estuary, Parangipettai. The collected mucus sample was then lyophilized and extracts namely, aqueous, acidic\r\nand organic were prepared and analysed for its antimicrobial activity against selected human and fish pathogens. The hemolytic\r\nefficacy of epidermal mucus was performed. The results of the present investigations reported that mucus of Mystus vittatus\r\npossess remarkable antimicrobial activity. The crude and organic extracts exhibited good haemolytic activity. Hence, the mucus\r\nextract could be a novel candidate against emerging disease scenario in the future. Also, this study will serve as the base for\r\nfurther in-depth investigations and structural elucidation....
Background: The primary target of the human immune response to the malaria parasite Plasmodium falciparum,\r\nP. falciparum erythrocyte membrane protein 1 (PfEMP1), is encoded by the members of the hyper-diverse var gene\r\nfamily. The parasite exhibits antigenic variation via mutually exclusive expression (switching) of the ~60 var genes\r\nwithin its genome. It is thought that different variants exhibit different host endothelial binding preferences that in\r\nturn result in different manifestations of disease.\r\nResults: Var sequences comprise ancient sequence fragments, termed homology blocks (HBs), that recombine at\r\nexceedingly high rates. We use HBs to define distinct var types within a local population. We then reanalyze a\r\ndataset that contains clinical and var expression data to investigate whether the HBs allow for a description of\r\nsequence diversity corresponding to biological function, such that it improves our ability to predict disease\r\nphenotype from parasite genetics. We find that even a generic set of HBs, which are defined for a small number of\r\nnon-local parasites: capture the majority of local sequence diversity; improve our ability to predict disease severity\r\nfrom parasite genetics; and reveal a previously hypothesized yet previously unobserved parasite genetic basis for\r\ntwo forms of severe disease. We find that the expression rates of some HBs correlate more strongly with severe\r\ndisease phenotypes than the expression rates of classic var DBLa tag types, and principal components of HB\r\nexpression rate profiles further improve genotype-phenotype models. More specifically, within the large Kenyan\r\ndataset that is the focus of this study, we observe that HB expression differs significantly for severe versus mild\r\ndisease, and for rosetting versus impaired consciousness associated severe disease. The analysis of a second much\r\nsmaller dataset from Mali suggests that these HB-phenotype associations are consistent across geographically\r\ndistant populations, since we find evidence suggesting that the same HB-phenotype associations characterize this\r\npopulation as well.\r\nConclusions: The distinction between rosetting versus impaired consciousness associated var genes has not been\r\ndescribed previously, and it could have important implications for monitoring, intervention and diagnosis.\r\nMoreover, our results have the potential to illuminate the molecular mechanisms underlying the complex spectrum\r\nof severe disease phenotypes associated with malariaââ?¬â?an important objective given that only about 1% of\r\nP. falciparum infections result in severe disease....
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