51 research outputs found
Anti Fungal Activity Of Methanolic Extract Of Usnea SP. Against Malassezia Furfur
The antifungal activity of methanolic extract of Usnea sp. (MEU) against Malassezia furfur ATCC 14521, in terms of in vitro susceptibility, minimum inhibitory concentration (MIC) and minimum fungicidal concentrations (MFC) were investigated using broth microdilution method with endpointafter 48 h. Time-kill curves were determined at concentrations 0~, 1/2~, 1~, 2~, 4~ and 8~MIC. MEU was susceptible against M. furfur with diameter clear zone of 34 mm for 1 mg/ml. MIC and MFC values were 16 ƒÊg/ml and 64 ƒÊg/ml, respectively. Time-kill curve demonstrated that treatment with 4~MIC (64 ƒÊg/ml) and 8~MIC (128 ƒÊg/ml) of MEU for 4 h and 1 h, respectively, was able to kill 100 % of M. furfur. MEU shows potential as an antifungal agent for inhibiting the growth of M. furfur ATCC 14521 in vitro. MEU might be a useful alternative for treating dandruff, tinea versicolor, tinea capitis, and seborrhoeicdermatitis due to the growth inhibition of M. furfur
Screening antimicrobial activity of tropical edible medicinal plant extracts against five standard microorganisms for natural food preservative
Edible medicinal plants are often used in the treatment of various ailments and spice in traditional food preparation. In this study, 45 of tropical edible medicinal plants extracts from Indonesia, Malaysia, and Thailand were screened for their antimicrobial activity against five standard microorganisms for food preservative namely
Aspergillus niger, Candida albicans, Escherichia coli,
Pseudomonas aeruginosa and Staphylococcus aureus.
The methanol extracts of Piper nigrum L. seed, Piper cubeba
L. seed, and the root of Ligusticum acutilobum Siebold and Zucc. showed antimicrobial activity against five species of standard microorganisms. Among them, P. cubeba
L. extract demonstrated the most susceptible against all tested microorganisms. Minimal inhibitory concentration (MIC) and minimal bactericidal or fungicidal concentration (MBC or MFC) were performed by the broth microdilution techniques as described by the Clinical and Laboratory Standard Institute. MIC values of P. cubeba L. extract to
A. niger, C. albicans, E. coli, P. aeruginosa and
S. aureus were 12.8, 1.6, 3.2, 6.4, and 1.6 mg/ml, respectively.
P. cubeba extract killed A. niger, C. albicans, E. coli,
P. aeruginosa and S. aureus with MBC values of 25.6, 3.2, 6.4, 12.8, and 3.2 mg/ml, respectively. The potent antimicrobial activity of P. cubeba L. extract may support its use for natural food preservative
Antibacterial activity of Boesenbergia rotunda (L.) Mansf. A. extract against Escherichia coli
An awareness of
Escherichia coli
as a foodborne pathogen and illness causing bacterium has
been increased among consumers. Moreover, there is demand for natural product in order to
reduce synthetic product that can cause toxic to the human. In this study, antibacterial activity,
in term of MIC, MBC and killing-time curve of methanolic extract of
Boesenbergia rotunda
have been tested against a standard
E. coli
ATCC 25922 and two
E. coli
isolated from milk
products using Clinical and Laboratory Standard Institute (CLSI) methods. The results show
that
B. rotunda
extract was susceptible to all
E. coli
strains. The MIC and MBC values of
B.
rotunda
extract against
E. coli
ranged 0.019 mg/mL
2.5 mg/mL and 0.039 mg/mL – 5.0 μg/mL,
respectively. Killing-time curves were constructed at concentrations of 0x MIC, 1/2x MIC, 1x
MIC, and 2x MIC. All
E. coli
strains can be killed with concentration of 2x MIC after 2 hours.
The results show that
B. rotunda
extract has potential antibacterial activity against
E. coli
Effect of Psidium guajava L. leaf extract on beef quality at different storage temperatures
Psidium guajava L., or guava, has been widely reported as having antimicrobial activities against foodborne pathogens. However, the efficacy of P. guajava leaf extract at different storage temperatures has not been extensively explored. Therefore, the present work investigated the effect of antibacterial activity of P. guajava leaf extract on beef quality at different storage temperatures. Disc diffusion assay was performed on selected foodborne pathogens (Bacillus cereus ATCC33019, B. megaterium ATCC14581, B. pumilus ATCC14884, B. subtilis ATCC6633, Escherichia coli ATCC43895, Enterobacter aerogenes ATCC13048, Klebsiella pneumoniae ATCC13773, Pseudomonas aeruginosa ATCC9027, Salmonella Typhimurium ATCC14028, and Staphylococcus aureus ATCC29737) to evaluate the antibacterial activity of the ethanolic extract of P. guajava leaves. The results revealed inhibition zones ranging from 7.00 ± 0.00 to 10.00 ± 0.00 mm. MIC and MBC assays were conducted to assess the bacteriostatic and bactericidal effects of the leaf extract at a concentration range of 0.08 to 2.50 mg/mL, and > 5.00 mg/mL, respectively. The stability of the leaf extract was also measured at different temperatures and pH conditions by disc diffusion assay with the minimum inhibition zone of 7.00 ± 0.00 mm. The application of P. guajava leaf extract (0.05, 0.50, and 5.00%) on beef samples resulted in a continuous decrease in Total Plate Count during 14-day storage at refrigerated (4.0 ± 2.0°C) and freezing (-18.0 ± 2.0°C) temperatures. The results revealed that P. guajava leaf extract can effectively serve as a natural meat preservative to prolong the shelf life of the treated beef up to 14 days
Assessing biofilm formation by Listeria monocytogenes
Abstract Listeria monocytogenes (L. monocytogenes) is a serious food-borne pathogen for immunocompromised individuals. L. monocytogenes is capable of producing biofilm on the surface of food processing lines and instruments. The biofilm transfers contamination to food products and impose risk to public health. Transfers contamination to food products, and impose risk hazard to public health. The aim of this study was to investigate biofilm producing ability of L. monocytogenes isolates. Microtitre assay was used to measure the amount of biofilm production by ten L. monocytogenes isolates from minced chicken / meat, sausages and burgers. Results showed that all 10 L. monocytogenes isolates were able to form biofilm after 24 h at 20˚C on polystyrene surface (the common surface in food industries). Some strains were capable of forming biofilm more than the others. All strains showed a slight raise in the quantities of attached cells over 48 and 72 h. L. monocytogenes strains isolated from minced chicken, minced meat and burgers were better biofilm-producers comparing to the strains isolated from sausages
Occurrence and antibiotic resistance of Salmonella spp. in raw beef from wet market and hypermarket in Malaysia
Salmonellae are highly pathogenic foodborne bacteria able to cause infection even at low doses. Infection by Salmonella from contaminated foods leads to gastrointestinal disease known as salmonellosis. Raw beef can be a source of human infection if the meat products are not properly handled, stored or cooked. This study aimed to investigate the prevalence and concentration of Salmonella in the raw beef sold at wet markets and hypermarkets in Serdang, Selangor, Malaysia, using MPN-PCR and MPN-plating on Xylose Lysine Deoxycholate (XLD) medium. In addition, Salmonella isolates recovered from the samples were tested for antibiotics susceptibility using Kirby-Bauer antibiotic susceptibility testing. The incidence of Salmonella in the raw beef samples using plating and PCR methods were 64.63% (53/82) and 17.07% (14/82) respectively. The microbial concentration of Salmonella in raw beef samples ranged between 3-4600 MPN/g by MPN-plating and 3-30 MPN/g by MPN-PCR approach. All isolates were found to be susceptible to imipenem, gentamicin, kanamycin, and chloramphenicol but resistant to cephalothin. It can be deduced from the results that raw beef can be a reservoir for Salmonella infection and the use of cephalothin (30 μg) in the treatment of infection due to these strains could be ineffective. Preventive measures such as proper temperature control as well as proper handling of raw beef in the market place are crucial to the minimization of any potential health hazard posed by this foodborne pathogen
Antimicrobial resistance of Listeria monocytogenes and Salmonella Enteritidis isolated from vegetable farms and retail markets in Malaysia
Listeriosis and salmonellosis are the major foodborne illnesses worldwide. Over the last decade, increasing reports about the antibiotic resistance of Listeria monocytogenes and Salmonella from diverse sources have prompted public health concerns, especially in developing countries with over reliance or misuse of antibiotic drugs in the treatment of humans and animals. In this study, antibiotic susceptibility profiles of 58 L. monocytogenes and 12 Salmonella Enteritidis strains from vegetable farms and retail markets in Malaysia were tested by the standard disk diffusion method. Listeria monocytogenes isolates were found to exhibit 100% resistance to penicillin G. Also, high resistance patterns were observed for meropenem (70.7%) and rifampicin (41.4%). The multiple antibiotic resistance (MAR) index of L. monocytogenes isolates ranged from 0.11 to 0.56. Besides, the antibiogram results revealed that multidrug-resistant (MDR) S. Enteritidis were detected and all the S. Enteritidis isolates demonstrated resistance to at least four antibiotics. Ampicillin, amoxicillin, and trimethoprim failed to inhibit all the S. Enteritidis strains. Salmonella Enteritidis isolates also displayed high resistance to nalidixic acid (75.0%), trimethoprim-sulfamethoxazole (75.0%), and chloramphenicol (66.7%). Findings in this study indicated that vegetables could be potential sources of multidrug resistance of L. monocytogenes and S. Enteritidis, which can be a serious issue and a major concern for public health. Thus, there is a great need for surveillance programs in Malaysia to continuously monitor the antibiotic resistance profiles of important pathogens
Occurrence and antibiotic resistance of Salmonella spp. in raw beef from wet market and hypermarket in Malaysia
Antibacterial activity of Thymoquinone, an active principle of Nigella sativa and its potency to prevent bacterial biofilm formation
<p>Abstract</p> <p>Background</p> <p>Thymoquinone is an active principle of <it>Nigella sativa </it>seed known as "Habbah Al-Sauda" in Arabic countries and "Sinouj" in Tunisia. Bacterial biofilms tend to exhibit significant tolerance to antimicrobials drugs during infections.</p> <p>Methods</p> <p>The antibacterial activity of Thymoquinone (TQ) and its biofilm inhibition potencies were investigated on 11 human pathogenic bacteria. The growth and development of the biofilm were assessed using the crystal violet (CV) and the 2, 3-bis [2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) reduction assay.</p> <p>Results</p> <p>TQ exhibited a significant bactericidal activity against the majority of the tested bacteria (MICs values ranged from 8 to 32 μg/ml) especially Gram positive cocci (<it>Staphylococcus aureus </it>ATCC 25923 and <it>Staphylococcus epidermidis </it>CIP 106510). Crystal violet assay demonstrated that the minimum biofilm inhibition concentration (BIC50) was reached with 22 and 60 μg/ml for <it>Staphylococcus aureus </it>ATCC 25923 and <it>Staphylococcus epidermidis </it>CIP 106510 respectively. In addition our data revealed that cells oxidative activity was influenced by TQ supplementation. In the same way, TQ prevented cell adhesion to glass slides surface.</p> <p>Conclusion</p> <p>The ability of TQ to prevent biofilm formation warrants further investigation to explore its use as bioactive substances with antibiofilm potential.</p
In Vitro and In Vivo Anti-Angiogenic Activities of Panduratin A
Targeting angiogenesis has emerged as an attractive and promising strategy in anti-cancer therapeutic development. The present study investigates the anti-angiogenic potential of Panduratin A (PA), a natural chalcone isolated from Boesenbergia rotunda by using both in vitro and in vivo assays.PA exerted selective cytotoxicity on human umbilical vein endothelial cells (HUVECs) with IC(50) value of 6.91 ± 0.85 µM when compared to human normal fibroblast and normal liver epithelial cells. Assessment of the growth kinetics by cell impedance-based Real-Time Cell Analyzer showed that PA induced both cytotoxic and cytostatic effects on HUVECs, depending on the concentration used. Results also showed that PA suppressed VEGF-induced survival and proliferation of HUVECs. Furthermore, endothelial cell migration, invasion, and morphogenesis or tube formation demonstrated significant time- and dose-dependent inhibition by PA. PA also suppressed matrix metalloproteinase-2 (MMP-2) secretion and attenuated its activation to intermediate and active MMP-2. In addition, PA suppressed F-actin stress fiber formation to prevent migration of the endothelial cells. More importantly, anti-angiogenic potential of PA was also evidenced in two in vivo models. PA inhibited neo-vessels formation in murine Matrigel plugs, and angiogenesis in zebrafish embryos.Taken together, our study demonstrated the distinctive anti-angiogenic properties of PA, both in vitro and in vivo. This report thus reveals another biological activity of PA in addition to its reported anti-inflammatory and anti-cancer activities, suggestive of PA's potential for development as an anti-angiogenic agent for cancer therapy
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