MyMedR

Displaying publications 781 - 800 of 942 in total

Abstract:

Sort:

Review: dalbavancin--a novel lipoglycopeptide antimicrobial for gram positive pathogens

Das B, Sarkar C, Biswas R, Pandey S

Pak J Pharm Sci, 2008 Jan;21(1):78-87.
PMID: 18166524

Glycopeptide antibiotics represent an important class of microbial compounds produced by several genera of actinomycetes. The emergence of resistance to glycopeptides among enterococci and staphylococci has prompted the search for second-generation drugs of this class and semi-synthetic derivatives are currently under clinical trials. Antimicrobial resistance among gram-positive organisms has been increasing steadily during the past several decades. Dalbavancin, a novel lipoglycopeptide, has a mechanism of action similar to that of other glycopeptides. It has in vitro activity against a variety of Gram-positive organisms specially multidrug resistant Staphylococcus aureus, but no activity against Gram-negative or vancomycin-resistant enterococci that possess vanA gene. Due to its prolonged half-life (6-10 days), dalbavancin can be administered intravenously once weekly. In Phase II and III clinical trials, dalbavancin was effective and well-tolerated for the treatment of skin and soft-tissue infections, catheter-related bloodstream infections, and skin and skin-structure infections. To date, adverse events have been mild and limited; the most common being pyrexia, headache, diarrhea. Dalbavancin appears to be a promising antimicrobial agent for the treatment of Gram-positive infections. Additional clinical data are required to fully assess its use. Despite the remarkable and favorable pharmacokinetic and pharmacodynamic properties, the use of this potent agent should be restricted to severe infections due to multidrug resistant organisms to limit the risk of selection of resistance. It is active against Gram-positive aerobes and anerobes, including resistant pathogens, with the exception of strains producing vanA-mediated resistance. Its approval by the FDA is expected soon. The extent to which dalbavancin will supplant vancomycin and whether it will be preferred over other newer agents such as linezolid in the next decade remains to be seen.

Matched MeSH terms: Gram-Positive Bacteria/drug effects; Gram-Positive Bacterial Infections/drug therapy*
Fulltext Bacteremia in patients with febrile neutropenia after chemotherapy at a university medical center in Malaysia

Baskaran ND, Gan GG, Kamarulzaman A, Sam IC

Int J Infect Dis, 2007 Nov;11(6):513-7.
PMID: 17459753

OBJECTIVES: This study was initiated to determine the local profile of blood culture isolates and antibiotic sensitivities in febrile neutropenic patients following chemotherapy, and to establish if any modifications to treatment guidelines are necessary.
DESIGN: A total of 116 episodes of febrile neutropenia admitted to the adult hematology ward at a university medical center in Malaysia were studied retrospectively from January 2004 to January 2005.
RESULTS: The study showed 43.1% of febrile neutropenic episodes had established bacteremia. Gram-negative bacteria accounted for 60.3% of isolates. Sensitivities of Gram-negative bacteria to the antibiotics recommended in the Infectious Diseases Society of America (IDSA) guidelines were 86.1-97.2%. Coagulase-negative staphylococci were the most common Gram-positive organisms isolated (23.3%). The majority of these were methicillin-resistant.
CONCLUSIONS: Carbapenem monotherapy, as recommended in the 2002 IDSA guidelines, is effective treatment for the infections most often encountered at our center. Combination therapy with an aminoglycoside should be considered when using ceftazidime, cefepime or piperacillin-tazobactam, particularly in high-risk patients. Vancomycin should be used if a Gram-positive organism is suspected or isolated.

Matched MeSH terms: Anti-Bacterial Agents/pharmacology; Bacteria/drug effects; Drug Resistance, Multiple, Bacterial
Simultaneous 4-chlorophenol and nitrogen removal in moving bed sequencing batch reactors packed with polyurethane foam cubes of various sizes

Lim JW, Lim PE, Seng CE, Adnan R

Bioresour Technol, 2013 Feb;129:485-94.
PMID: 23266850 DOI: 10.1016/j.biortech.2012.11.111

Moving bed sequencing batch reactors (MBSBRs) packed with 8% (v/v) of 8-, 27- and 64-mL polyurethane (PU) foam cubes, respectively, were investigated for simultaneous 4-chlorophenol (4-CP) and nitrogen removal at increasing 4-CP concentration. When the 4-CP concentration exceeded 300 mg L(-1), the MBSBR with 27-mL foam cubes was observed to outperform the other MBSBRs in removing 4-CP and nitrogen. The reasons were: (1) there were more biomass in inner layer of the 27-mL cubes, compared to that of the 8-mL cubes, which was more shielded from the inhibitory effect of 4-CP and (2) the 27-mL cubes were more mobile than the 64-mL cubes. Although increasing 4-CP concentration to 600 mg L(-1) resulted in incomplete removal of 4-CP in the MBSBRs, results of the batch reactor with 27-mL foam cubes showed that complete 4-CP removal within the REACT period could be achieved by increasing the packing volume to 20%.

Matched MeSH terms: Bacteria, Anaerobic/metabolism*
New insight into the structural, electrochemical and biological aspects of macroacyclic Cu(II) complexes derived from S-substituted dithiocarbazate schiff bases

Low ML, Maigre L, Tahir MI, Tiekink ER, Dorlet P, Guillot R, et al.

Eur J Med Chem, 2016 Sep 14;120:1-12.
PMID: 27183379 DOI: 10.1016/j.ejmech.2016.04.027

Copper (II) complexes synthesized from the products of condensation of S-methyl- and S-benzyldithiocarbazate with 2,5-hexanedione (SMHDH2 and SBHDH2 respectively) have been characterized using various physicochemical (elemental analysis, molar conductivity, magnetic susceptibility) and spectroscopic (infrared, electronic) methods. The structures of SMHDH2, its copper (II) complex, CuSMHD, and the related CuSBHD complex as well as a pyrrole byproduct, SBPY, have been determined by single crystal X-ray diffraction. In order to provide more insight into the behaviour of the complexes in solution, electron paramagnetic resonance (EPR) and electrochemical experiments were performed. Antibacterial activity and cytotoxicity were evaluated. The compounds, dissolved in 0.5% and 5% DMSO, showed a wide range of antibacterial activity against 10 strains of Gram-positive and Gram-negative bacteria. Investigations of the effects of efflux pumps and membrane penetration on antibacterial activity are reported herein. Antiproliferation activity was observed to be enhanced by complexation with copper. Preliminary screening showed Cu complexes are strongly active against human breast adenocarcinoma cancer cell lines MDA-MB-231 and MCF-7.

Matched MeSH terms: Anti-Bacterial Agents/pharmacology; Anti-Bacterial Agents/chemistry; Bacteria/drug effects
Flemingin-Type Prenylated Chalcones from the Sarawak Rainforest Plant Desmodium congestum

Rees KA, Bermudez C, Edwards DJ, Elliott AG, Ripen JE, Seta C, et al.

J Nat Prod, 2015 Aug 28;78(8):2141-4.
PMID: 26284978 DOI: 10.1021/acs.jnatprod.5b00410

In an ongoing program to identify new anti-infective leads, an extract derived from whole plant material of Desmodium congestum collected in the Sarawak rainforest was found to have anti-MRSA activity. Bioassay-guided isolation led to the isolation of two new prenylated chalcones, 5'-O-methyl-3-hydroxyflemingin A (1) and 5'-O-methylflemingin C (2), which were closely related to the flemingins previously isolated from various Flemingia species. Chalcones 1 and 2, which were determined to be 4:6 enantiomeric mixtures by chiral HPLC, exhibited moderate activity against a panel of Gram-positive bacteria and were also cytotoxic to the HEK293 human embryonic kidney cell line.

Matched MeSH terms: Gram-Positive Bacteria/drug effects
Antibiotics in chronic suppurative otitis media: a bacteriologic study

Indudharan R, Haq JA, Aiyar S

Ann Otol Rhinol Laryngol, 1999 May;108(5):440-5.
PMID: 10335703

Conservative medical management of chronic suppurative otitis media (CSOM) is an important step in achieving a dry ear. Topical antibiotic ear drops and aural toilet form the mainstay of medical management of noncholesteatomatous CSOM. This study analyzes the causal organisms and their sensitivity to various antibiotics. Out of 382 swabs examined, the major organisms isolated were Pseudomonas aeruginosa (27.2%), followed by Staphylococcus aureus (23.6%). The sensitivity of P. aeruginosa was 100% to ceftazidime, 98.9% to ciprofloxacin, 96.3% to gentamicin, and 95.4% to polymyxin B, whereas the sensitivity of S. aureus was 98.6% to ciprofloxacin, 97.4% to cloxacillin sodium, 96.5% to cotrimoxazole, and 90.7% to gentamicin. Pseudomonas aeruginosa was almost completely resistant to ampicillin (97.6%) and chloramphenicol (96.6%), whereas S. aureus was almost completely resistant to ampicillin (73.8%) and polymyxin B (98.3%). Among the available topical antibiotic preparations for use in the ear, we found that ciprofloxacin and gentamicin are the best choices.

Matched MeSH terms: Anti-Bacterial Agents/therapeutic use*; Bacteria/isolation & purification
Novel halogenated metabolites from the Malaysian Laurencia pannosa

Suzuki M, Daitoh M, Vairappan CS, Abe T, Masuda M

J Nat Prod, 2001 May;64(5):597-602.
PMID: 11374951

In connection with our chemotaxonomic studies of Malaysian species of the red algal genus Laurencia, the chemical composition of Laurencia pannosa Zanardini was examined. Two halogenated sesquiterpenoids, named pannosanol (1) and pannosane (2), have been isolated along with a halogenated C15-acetogenin, (3Z)-chlorofucin (3). The structures of these compounds were determined from their spectroscopic data (IR, 1H NMR, 13C NMR, 2D NMR, and MS). Pannosanol and pannosane are novel halometabolites with an unusual rearranged chamigrane framework. Antibacterial activities of these metabolites against marine bacteria are also described.

Matched MeSH terms: Anti-Bacterial Agents/isolation & purification; Anti-Bacterial Agents/pharmacology; Anti-Bacterial Agents/chemistry*; Bacteria/drug effects
Septicaemia in paediatric cancer patients: a 5-year surveillance study in university hospital, Kuala Lumpur, Malaysia

Ariffin H, Ariffin W, Peng LH, Parasakthi N

J Trop Pediatr, 1997 10;43(5):279-81.
PMID: 9364125 DOI: 10.1093/tropej/43.5.279

Infectious complications are the major cause of morbidity and mortality in children with malignancy. Empirical antimicrobial therapy in the management of fever of unknown origin should be tailored to local bacteriological data and antibiotic sensitivity patterns. Five-hundred-and-fifty-nine cases of culture-proven septicaemia occurring in pediatric cancer patients between 1990 and 1994 were retrospectively analysed and compared with a similar study done in our centre between 1976 and 1979. A wide spectrum of organisms was isolated. Staphylococcus epidermidis, Staphylococcus aureus, and Klebsiella pneumoniae were the most common and consistent bacteria isolated during the 5 year period. More than 70 per cent of the staphylococci were sensitive to methicillin and universally sensitive to vancomycin. However, a worrying trend of ceftazidime-resistance amongst gram-negative organisms was found. In these situations, the use of imipenem is recommended as resistance to this antimicrobial agent was exceedingly rare.

Matched MeSH terms: Bacteria/isolation & purification; Bacterial Infections/drug therapy; Bacterial Infections/microbiology*
Fulltext Evaluation of the bacteriological contamination of a closed feeding system for enteral nutrition

Chan L, Yasmin AH, Ngeow YF, Ong GS

Med J Malaysia, 1994 Mar;49(1):62-7.
PMID: 8057993

A closed enteral delivery system consisting of a cardboard tetrapack containing the sterile ready-to-use liquid feed and an independent sterile administration set, has been devised. We found bacterial contamination within 24 hours in this system in patients on ventilatory support in intensive care. This emphasises the need for meticulous care in handling enteral feeding systems to prevent environmental contamination.

Matched MeSH terms: Bacteria/isolation & purification*
The bacteriology of brain abscess: a local experience in Malaysia

Puthucheary SD, Parasakthi N

Trans R Soc Trop Med Hyg, 1990 7 1;84(4):589-92.
PMID: 2091359

31 cases of intracranial abscess seen over a period of 10 years showed a peak incidence in the second and third decades of life with a male preponderance. Tetralogy of Fallot and other congenital cyanotic heart diseases were the predominant associated factors (32%). The commonest site of infection was the frontal lobe. Gram-stained smears of pus proved to be extremely useful. The majority of the organisms (82%) were either microaerophilic or anaerobic bacteria with Streptococcus milleri being the most frequent isolate. With the exception of Corynebacterium species, all isolates were susceptible to penicillin or chloramphenicol, most being susceptible to both.

Matched MeSH terms: Bacteria/isolation & purification
Ceftazidime/metronidazole versus netilmicin/metronidazole in the treatment of perforated appendicitis in children

Kooi GH, Pit S

Clin Ther, 1990 Jan-Feb;12(1):54-60.
PMID: 2183940

One hundred children with peritonitis resulting from a perforated appendix were treated with ceftazidime or netilmicin. Metronidazole was added to both groups to treat the anaerobic organisms commonly associated with the infecting aerobic organisms in peritonitis. Escherichia coli was the most common aerobe found in peritoneal pus. Wound infection occurred in nine patients of the netilmicin group and in none treated with ceftazidime (P less than 0.01). No bacterial resistance was evident in the ceftazidime group, but gram-positive streptococci found in eight patients were resistant to netilmicin. Thus it is recommended that an antibiotic of the penicillin group be added if netilmicin is used to treat peritonitis. The results indicate that ceftazidime was more effective than netilmicin in the treatment of children with peritonitis resulting from a perforated appendix.

Matched MeSH terms: Bacteria/isolation & purification
Fermentation of blueberry and blackberry juices using Lactobacillus plantarum, Streptococcus thermophilus and Bifidobacterium bifidum: Growth of probiotics, metabolism of phenolics, antioxidant capacity in vitro and sensory evaluation

Wu Y, Li S, Tao Y, Li D, Han Y, Show PL, et al.

Food Chem, 2021 Jun 30;348:129083.
PMID: 33517000 DOI: 10.1016/j.foodchem.2021.129083

In this study, three potential probiotic strains were selected to ferment blueberry and blackberry juices. The viable cell counts of selected strains were increased by 0.4-0.7 log CFU/mL in berry juices environments after 48-h fermentation. Meanwhile, the contents of cyanindin-3-glucoside and peonidin-3-glucoside decreased over 30%. Heatmap presented an upgrade trend of syringic acid, ferulic acid, gallic acid and lactic acid during fermentation. However, the contents of p-coumaric acid, protocatechuic acid, chlorogenic acid, critic acid and malic acid showed downgrade trend. The metabolism of phenolics probably contributed to the enhancement of the ABTS radical scavenging activity (40%-60%) in fermented berry juices. Moreover, the three strains presented different capacities on changing the quality of berry juices according to the PCA and LDA analysis. The contents of individual organic acids had positive correlations with sensory quality, especially for sourness. Overall, probiotic fermentation could improve the sensory quality of berry juices.

Matched MeSH terms: Bacteria/metabolism*
Fulltext Influence of bacterial organic selenium on blood parameters, immune response, selenium retention and intestinal morphology of broiler chickens

Dalia AM, Loh TC, Sazili AQ, Samsudin AA

BMC Vet Res, 2020 Sep 29;16(1):365.
PMID: 32993790 DOI: 10.1186/s12917-020-02587-x

BACKGROUND: Several studies indicated that dietary organic selenium (Se) usually absorbed better than an inorganic source, with high retention and bioavailability. Dietary Se as an antioxidant element affects the immune system and hematological status in animals. Therefore, the aim of this study was to evaluate the effect of dietary supplementation of bacterial selenium as an organic source on hematology, immunity response, selenium retention, and gut morphology in broiler chickens.
RESULTS: The present results revealed that supplementation of inorganic Se was associated with the lowest level of RBC, HB, and PCV with significant difference than ADS18-Se. In the starter stage, both T2 and T5 were associated with the significantly highest IgG level compared to the basal diet, while all supplemented groups showed higher IgM levels compared to the control group. In the finisher phase, all Se supplemented groups showed significant (P ˂ 0.05) increases in IgG, IgA, and IgM levels compared to T1. Birds fed bacterial-Se showed high intestinal villus height and better Se retention more than sodium selenite. The organic selenium of ADS18 had a superior action in improving Se retention compared to ADS1 and ADS2 bacterial Se.
CONCLUSIONS: Bacterial organic Se had a beneficial effect on the villus height of small intestine led to high Se absorption and retention. Thus, it caused a better effect of Se on hematological parameters and immunity response.

Matched MeSH terms: Bacteria/chemistry
Hibiscus cannabinus L. (kenaf) studies: Nutritional composition, phytochemistry, pharmacology, and potential applications

Sim YY, Nyam KL

Food Chem, 2021 May 15;344:128582.
PMID: 33199120 DOI: 10.1016/j.foodchem.2020.128582

The electronic database was searched up to July 2020, using keywords, kenaf and roselle, chemical constituents of kenaf and roselle, therapeutic uses of kenaf and roselle. Journals, books and conference proceedings were also searched. Investigations of pharmacological activities of kenaf revealed that this edible plant exhibits a broad range of therapeutic potential including antioxidant, antimicrobial, antityrosinase, anticancer, antihyperlipidemia, antiulcer, anti-inflammatory, and hepatoprotective activities. Kenaf also showed versatile utility as a functional ingredient in food, folk medicine, and animal nutritions, as well as in nanotechnology processes. The exploitation of underexploited kenaf by-products can be a significant part of waste management from an economic and environmental point of view. In addition, kenaf showed comparable nutritional, phytochemical, and pharmacological properties with Hibiscus sabdariffa (Roselle). This review has important implications for further investigations and applications of kenaf in food and pharmaceuticals industry.

Matched MeSH terms: Bacteria/drug effects
Fulltext Effect of Hybrid mono/bimetallic Nanocomposites for an enhancement of Catalytic and Antimicrobial Activities

Sivaranjan K, Padmaraj O, Santhanalakshmi J, Sathuvan M, Sathiyaseelan A, Sagadevan S

Sci Rep, 2020 02 13;10(1):2586.
PMID: 32054936 DOI: 10.1038/s41598-020-59491-5

Exploring the new catalytic systems for the reduction of organic and inorganic pollutants from an indispensable process in chemical, petrochemical, pharmaceutical and food industries, etc. Hence, in the present work, authors motivated to synthesize bare reduced graphene oxide (rGO), polyaniline (PANI), three different ratios of rGO-PANI(80:20,50:50, 10:90) composites and rGO-PANI(80:20,50:50, 10:90) supported mono (Pd) & bimetallic [Pd: Au(1:1,1:2, 2:1)] nanocomposite by a facile chemical reduction method. Also, it investigated their catalytic performances for the reduction of organic/inorganic pollutants and antimicrobial activities. All the freshly prepared bare rGO, PANI, three different ratios of rGO-PANI(80:20, 50:50,10:90) composites and rGO-PANI(80:20, 50:50,10:90)/Pd & Pd: Au(1:1, 1:2,2:1) nanocomposite hybrid catalysts were characterized using UV-Vis, FT-IR, SEM, FE-SEM, EDAX, HR-TEM, XRD, XPS and Raman spectroscopy analysis. Among them, an optimized best composition of rGO-PANI(80:20)/Pd: Au(1:1) bimetallic nanocomposite hybrid catalyst exhibits better catalytic reduction and antimicrobial activities than other composites, as a result of strong electrostatic interactions between rGO, PANI and bimetal (Pd: Au) NPs through a synergistic effect. Hence, an optimized rGO-PANI(80:20)/Pd:Au(1:1) bimetallic nanocomposite catalyst would be considered as a suitable catalyst for the reduction of different nitroarenes, organic dyes, heavy metal ions and also significantly inhibit the growth of S. aureus, S. Typhi as well as Candida albicans and Candida kruesi in wastewater.

Matched MeSH terms: Bacteria/drug effects
Therapeutic challenges in the era of antibiotic resistance

Lee C

Int J Antimicrob Agents, 2008 Dec;32 Suppl 4:S197-9.
PMID: 19134519 DOI: 10.1016/S0924-8579(09)70002-0

Multidrug microbial resistance poses major challenges to the management of infection, particularly with the paucity of new drugs with activity against these bacteria. Since the turn of this century a few new antibiotics have been licensed, including linezolid, daptomycin and tigecycline. This supplement reports data presented at the 13th International Congress of Infectious Diseases held in Kuala Lumpur in June 2008. Dr R. Isturiz reviews the data on global resistance trends and the potential impact on empirical therapy; Dr J.-H. Song reviews new agents on the antimicrobial horizon; and the final paper in the supplement, by Dr L.R. Peterson, reviews the role of tigecycline in the management of complicated intra-abdominal and skin and soft tissue infections.

Matched MeSH terms: Anti-Bacterial Agents/pharmacology; Anti-Bacterial Agents/therapeutic use*; Bacteria/drug effects*; Bacterial Infections/drug therapy*
Exploring the potential of halotolerant bacteria for biodegradation of polycyclic aromatic hydrocarbon

Al Farraj DA, Hadibarata T, Yuniarto A, Alkufeidy RM, Alshammari MK, Syafiuddin A

Bioprocess Biosyst Eng, 2020 Dec;43(12):2305-2314.
PMID: 32812060 DOI: 10.1007/s00449-020-02415-4

The present study aimed to determine the degradation and transformation of three-ring PAHs phenanthrene and anthracene by Cryptococcus sp. MR22 and Halomonas sp. BR04 under halophilic conditions. The growth progress of Cryptococcus sp. MR22 and Halomonas sp. BR04 on anthracene and phenanthrene was monitored by colony-forming unit (CFU) technique. The growth of the bacteria was maintained at a maximum concentration of 200 mg/L of all tested hydrocarbon, indicating that Cryptococcus sp. MR22 and Halomonas sp. BR04 significantly perform in the removal of the PAH-contaminated medium at low concentrations. The fit model to represent the biodegradation kinetics of both PAHs was first-order rate equation The extract prepared from cells supplemented with three different substrates exhibited some enzymes such as hydroxylase, dioxygenase, laccase and peroxidase. The results suggest that both strains had an impressive ability in the degradation of aromatic and aliphatic hydrocarbon but also could tolerate in the extreme salinity condition.

Matched MeSH terms: Bacteria/metabolism*
Fulltext Differences in the bacteriome of swab, saliva, and tissue biopsies in oral cancer

Gopinath D, Menon RK, Wie CC, Banerjee M, Panda S, Mandal D, et al.

Sci Rep, 2021 01 13;11(1):1181.
PMID: 33441939 DOI: 10.1038/s41598-020-80859-0

Microbial dysbiosis has been implicated in the pathogenesis of oral cancer. We analyzed the compositional and metabolic profile of the bacteriome in three specific niches in oral cancer patients along with controls using 16SrRNA sequencing (Illumina Miseq) and DADA2 software. We found major differences between patients and control subjects. Bacterial communities associated with the tumor surface and deep paired tumor tissue differed significantly. Tumor surfaces carried elevated abundances of taxa belonging to genera Porphyromonas, Enterobacteriae, Neisseria, Streptococcus and Fusobacteria, whereas Prevotella, Treponema, Sphingomonas, Meiothermus and Mycoplasma genera were significantly more abundant in deep tissue. The most abundant microbial metabolic pathways were those related to fatty-acid biosynthesis, carbon metabolism and amino-acid metabolism on the tumor surface: carbohydrate metabolism and organic polymer degradation were elevated in tumor tissues. The bacteriome of saliva from patients with oral cancer differed significantly from paired tumor tissue in terms of community structure, however remained similar at taxonomic and metabolic levels except for elevated abundances of Streptococcus, Lactobacillus and Bacteroides, and acetoin-biosynthesis, respectively. These shifts to a pro-inflammatory profile are consistent with other studies suggesting oncogenic properties. Importantly, selection of the principal source of microbial DNA is key to ensure reliable, reproducible and comparable results in microbiome studies.

Matched MeSH terms: Bacteria/genetics*; DNA, Bacterial/genetics
Fulltext Investigation on antimicrobial activity of root extracts of Thespesia populnea Linn

Senthil-Rajan D, Rajkumar M, Srinivasan R, Kumarappan C, Arunkumar K, Senthilkumar KL, et al.

Trop Biomed, 2013 Dec;30(4):570-8.
PMID: 24522124 MyJurnal

Many medicinal plants have been used for centuries in daily life to treat microbial diseases all over the world. In this study, the in vitro antibacterial activity of aqueous and ethanol root extracts of Thespesia populnea Linn were investigated. Antimicrobial properties of T. populnea Linn was evaluated against five pathogenic bacteria and two fungi. Disc diffusion method and minimum inhibitory concentration (MIC) were determined by broth serial dilution method. The ciprofloxacin (5 μg/ml) and flucanozole (100 units/disc) were used as positive controls for bacteria and fungi respectively. Different concentrations (50, 100, 150 μg/ml) of ethanolic and aqueous root extracts of T. populnea were checked for the dose dependent antibacterial activity. Thespesia populnea showed broad spectrum antimicrobial activity against gram positive and gram negative bacteria and maximum inhibition by ethanolic extract was observed at higher dose (250 μg/ml) as 27±0.2mm. The MIC of the ethanol extract was 10 μg/ml for Staphylococcus aureus and 750 μg/ml for Candida albicans. The antifungal activity offered against S. aureus by the ethanolic extract is more than the aqueous extract. The results concluded that the anti-microbial activity of T. populnea was dose dependent. As the concentration increased the inhibition zone also increased. Flavonoids and tannins present in the extracts may be responsible for the antimicrobial activity.

Matched MeSH terms: Bacteria/drug effects*
Fulltext Bacteria as a source of oviposition attractant for Aedes aegypti mosquitoes

Arbaoui AA, Chua TH

Trop Biomed, 2014 Mar;31(1):134-42.
PMID: 24862053 MyJurnal

Since a safe and effective mass vaccination program against dengue fever is not presently available, a good way to prevent and control dengue outbreaks depends mainly on controlling the mosquito vectors. Aedes aegypti mosquito populations can be monitored and reduced by using ovitraps baited with organic infusions. A series of laboratory experiments were conducted which demonstrated that the bacteria in bamboo leaf infusion produce volatile attractants and contact chemical stimulants attractive to the female mosquitoes. The results showed that the female mosquitoes laid most of their eggs (59.9 ± 8.1 vs 2.9 ± 2.8 eggs, P<0.001) in bamboo leaf infusions when compared to distilled water. When the fresh infusion was filtered with a 0.45 μm filter membrane, the female mosquitoes laid significantly more eggs (64.1 ± 6.6 vs 4.9 ± 2.6 eggs, P<0.001) in unfiltered infusion. However when a 0.8 μm filter membrane was used, the female laid significantly more eggs (62.0 ± 4.3 vs 10.1 ± 7.8 eggs, P<0.001) in filtrate compared to a solution containing the residue. We also found that a mixture of bacteria isolated from bamboo leaf infusion serve as potent oviposition stimulants for gravid Aedes mosquitoes. Aedes aegypti laid significantly more eggs (63.3 ± 6.5 vs 3.1 ± 2.4 eggs, P<0.001) in bacteria suspension compared to sterile R2A medium. Our results suggest microbial activity has a role in the production of odorants that mediate the oviposition response of gravid mosquitoes.

Matched MeSH terms: Bacteria/chemistry*

Filters

Please provide feedback to Administrator ([email protected])

External Links