Current Issue : April - June Volume : 2014 Issue Number : 2 Articles : 7 Articles
Two marine algae (Acanthophora spicifera and Padina tetrastromatica) collected from Madapam coastal areas, Rameshwaram, India were screened for antibacterial activity and minimum inhibitory activity. The seaweeds were extracted by using five different solvents i.e Dichloromethane, Methanol, Hexane, Diethylether and Acetone. All the seaweeds were evaluated antimicrobial activity and minimum inhibitory concentration. The cured compound of Acanthophora spicifera and Padina tetrastromatica was analysis by FTIR. Padina tetrastromatica was analysised by GC MS. Based on the antibacterial and minimum inhibitory concentration diethyl ether extract of P. tetrastromatica and Methanol extract of A. spicifera showed a better zone inhibition and lowest MIC level against the human pathogens. The cured bioactive compound of diethylether extract of P. tetrastromatica and methanol extract of A. spicifera were analysis by FTIR. Di ethyl ether extract of P. tetrastromatica was analysised by GCMS. Based on the GCMS result P. tetrastromatica the active cured extract was composed of volatile metabolites and fatty acids. Most of the seaweeds contain fatty acids. In this fatty acids show a good antimicrobial activity against human pathogen. Based on the FTIR and GCMS results clearly show that seaweeds P. tetrastromatica are an interesting source for biologically active compounds that may be applied for prophylaxis and therapy of human infection, these compounds could be utilized for the development of medically potential products....
Contrary to the classical concept that quinolone resistance mostly originates from chromosomal mutations, plasmid-mediated quinolone resistance (PMQR) has been recently reported in several parts of the world. Three different mechanisms have been identified to date: target protection by Qnr proteins, enzymatic inactivation by the aminoglycoside acetyltransferase AAC(6â��)-Ib-cr and, more recently, active efflux by the QepA pump. We screened qnrA, qnrB, and qnrS among nalidixic acid resistant Escherichia coli and Klebsiella pneumonia isolates. The plasmid-mediated quinolone determinants (qnr genes) were detected in 14 isolates out of 26 nalidixic acid resistant isolates with a percentage of 54%. Out of 14 qnr positive isolates, 9 (64%) were K. pneumoniae and 5 (36%) were E. coli. The qnrA and qnrB genes were detected, alone or in combination, in 4(15%) and 12 (46%) isolates respectively from 26 nalidixic acid resistant isolates that were chosen for PCR studies. In 2 isolates (K33 and E16), both qnrA and qnrB were simultaneously detected whereas qnrS gene wasnâ��t detected in any qnr positive isolates. In our study, Extended-Spectrum �Ÿ-Lactamases (ESBLs), AmpC �Ÿ-lactamases and carbapenemases were detected using double disc diffusion test, AmpC disk test and Modified Hodge Test respectively and it was found that 43% (6/14), 57% (8/14) and 21% (3/14) of qnr positive isolates produced ESBLs, AmpC �Ÿ-lactamases and carbapenemases respectively. According to our results, there is a strong correlation between PMQR determinants (qnr genes) and �Ÿ-lactamases whether ESBLs or AmpC �Ÿ-lactamases or even carbapenemases....
Raw milk is a potential source of Staphylococcus aureus in milk and milk products, especially in the case of defective pasteurization. The main reservoir of Staphylococcus aureus seems to be the infected quarter. The present study was carried out to detect the Staphylococcus aureus from milk samples collected from the suspected milch animals for sub clinical mastitis in the teaching veterinary clinical complex, Rajendranagar. The collected milk samples were poured into Brain Heart Infusion agar and incubated at 37oC for 24 hrs. DNA templates were prepared from inoculums by boiling and snap chilling method. PCR assay was standardized for primers from thermonuclease (nuc) gene to detect Staphylococcus aureus in milk samples by using gradient PCR which gave amplification product with a molecular weight of 270 bp. Out of 80 milk samples screened for presence of Staphylococcus aureus by PCR assay, 60 % samples gave positive result for Staphylococcus aureus which indicates that the major etiological agent for subclinical mastitis is Staphylococcus aureus and causes public health problems due to consumption of defective pasteurization....
Background: Enterococci, ubiquitous colonizers of humans and other animals, play an increasingly important role\r\nin health-care associated infections (HAIs). It is believed that the recent evolution of two clinically relevant species,\r\nEnterococcus faecalis and Enterococcus faecium occurred in a big part in a hospital environment, leading to\r\nformation of high-risk enterococcal clonal complexes (HiRECCs), which combine multidrug resistance with increased\r\npathogenicity and epidemicity. The aim of this study was to establish the species composition in wastewater, its\r\nmarine recipient as well as a river estuary and to investigate the antimicrobial susceptibility of collected isolates.\r\nMolecular methods were additionally applied to test the presence of HiRRECC-related E. faecium.\r\nResults: Two wastewater treatment plants (WWTPs), their marine outfalls and Vistula river that influence\r\nsignificantly the quality of waters in Gulf of Gdansk were sampled to investigate the presence of Enterococcus spp.\r\nFour-hundred-twenty-eight isolates were obtained, including E. faecium (244 isolates, 57.0%), E. hirae (113 isolates,\r\n26.4%) and E. faecalis (63 isolates, 14.7%); other species (E. gallinarum/casseliflavus, E. durans and E. avium) accounted\r\nfor 1.9%. Antimicrobial susceptibility testing revealed the presence of isolates resistant to erythromycin, tetracycline,\r\namipicillin, fluoroquinolones and aminoglycosides (high-level resistance), especially among E. faecium, where such\r\nisolates were usually characterized by multilocus sequence types associated with nosocomial lineages 17, 18 and\r\n78 of this species representing HiRECC, formerly called CC17. These isolates not only carried several resistance\r\ndeterminants but were also enriched in genes encoding pathogenicity factors (Esp, pili) and genes associated with\r\nmobile genetic elements (MGE), a feature also typical for nosocomial HiRECC.\r\nConclusions: Our data show that WWTPs constitute an important source of enterococcal strains carrying\r\nantimicrobial resistance determinants, often associated with the presence of MGE, for the recipient water\r\nenvironment, thus increasing a pool of such genes for other organisms. The presence of HiRECCs in wastewaters\r\nand marine/river environment may indicate that adaptations gained in hospitals may be also beneficial for survival\r\nof such clones in other settings. There is an obvious need to monitor the release and spread of such strains in\r\norder to elucidate better ways to curb their dissemination....
Background: Successful viral infection requires the involvement of host cellular factors in their life cycle. Heat shock\r\nprotein 70 (HSP70) can be recruited by numerous viruses to promote the folding, maturation, or assembly of viral\r\nproteins. We have previously shown that HSP70 is significantly elevated in porcine reproductive and respiratory\r\nsyndrome virus (PRRSV)-infected lungs, suggesting HSP70 may play a potential role during PRRSV infection. In this\r\nstudy, we tried to investigate the role of HSP70 during PRRSV infection.\r\nResults: In this study, we observed that PRRSV infection induced the expression of HSP70. The down-regulation of\r\nHSP70 using quercetin, a HSPs synthesis inhibitor, or small interfering RNAs (siRNA) reduced the viral protein level\r\nand viral production. Notably, these inhibitory effects on PRRSV infection could be attenuated by heat shock\r\ntreatment. In addition, HSP70 was found to colocalize with the viral double-stranded RNA (dsRNA) and knockdown\r\nof HSP70 decreased the dsRNA levels, suggesting HSP70 is involved in the formation of viral replication and\r\ntranscription complex (RTC) and thus affects the viral replication.\r\nConclusions: Our study revealed that HSP70 is an essential host factor required for the replication of PRRSV. The\r\ninhibition of HSP70 significantly reduced PRRSV replication, which may be applied as an effective antiviral strategy....
Background: Vascular endothelial growth factor (VEGF) is a key angiogenic factors. It plays an important role in\r\nboth physiologic and pathologic angiogenesis and increases permeability across the vessels. Using antibody phage\r\ndisplay technology, we obtained a novel anti-VEGFA IgG, named as FD006. In this study, the pharmacological\r\ncharacteristics and efficacy of FD006 in corneal neovascularization (CoNV) were evaluated.\r\nResults: FD006 was predicted to have similar binding mode to bevacizumab. Experimental analysis showed that\r\nthe binding ability of FD006 seemed a little stronger than bevacizumab, for the EC50 of FD006 to bind VEGF\r\nanalyzed by ELISA was about 0.037 �µg/mL while that of bevacizumab was 0.18 �µg/mL. Binding kinetics assays\r\nshowed similar results that FD006 possessed 2-fold higher affinity to bind VEGF than bevacizumab due to slower\r\ndissociation rate of FD006; meanwhile, FD006 inhibited the VEGF-induced proliferation of HUVEC with an IC50 value\r\nof 0.031 �± 0.0064 �µg/ml, which seemed similar or a litter better than bevacizumab (0.047 �± 0.0081 �µg/ml). The\r\nsubconjunctival administration of FD006, bevacizumab or dexamethasone could significantly inhibit the growth of\r\nCoNV contrasting to N.S (p < 0.01). At the early stage, FD006 showed better inhibitory effect on the growth of CoNV\r\ncompared with bevacizumab (p < 0.05). Western blot analysis showed that FD006 could inhibit the expression of\r\nVEGF, VEGFR-1, VEGFR-2, MMP-9 and ICAM-1, which could explain its favorable anti-angiogenic activity.\r\nConclusions: The pharmacological characteristics of FD006 were similar or even a little better than bevacizumab in\r\ninhibiting corneal neovascularization...
Background: Nitric oxide (NO) is produced as part of the host immune response to bacterial infections, including\r\nurinary tract infections. The enzyme flavohemoglobin, coded by the hmp gene, is involved in protecting bacterial\r\ncells from the toxic effects of NO and represents a potentially interesting target for development of novel\r\ntreatment concepts against resistant uropathogenic bacteria. The aim of the present study was to investigate if\r\nthe in vitro antibacterial effects of NO can be enhanced by pharmacological modulation of the enzyme\r\nflavohemoglobin.\r\nResults: Four clinical isolates of multidrug-resistant extended-spectrum �Ÿ-lactamase (ESBL)-producing uropathogenic\r\nE. coli were included in the study. It was shown that the NO-donor substance DETA/NO, but not inactivated DETA/NO,\r\ncaused an initial growth inhibition with regrowth noted after 8 h of exposure. An hmp-deficient strain showed a\r\nprolonged growth inhibition in response to DETA/NO compared to the wild type. The imidazole antibiotic miconazole,\r\nthat has been shown to inhibit bacterial flavohemoglobin activity, prolonged the DETA/NO-evoked growth inhibition.\r\nWhen miconazole was combined with polymyxin B nonapeptide (PMBN), in order to increase the bacterial wall\r\npermeability, DETA/NO caused a prolonged bacteriostatic response that lasted for up to 24 h.\r\nConclusion: An NO-donor in combination with miconazole and PMBN showed enhanced antimicrobial effects and\r\nproved effective against multidrug-resistant ESBL-producing uropathogenic E. coli....
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