scholarly journals Antibacterial activity of taro [Colocasia esculenta (L.) Schott] leaves extract against foodborne pathogens and its effect on microbial population in raw chicken meat

Food Research ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 401-409
Author(s):  
A.M. Alzabt ◽  
Y. Rukayadi
Keyword(s):  
Antibacterial Activity ◽  
Foodborne Pathogens ◽  
Microbial Population ◽  
Residual Effect ◽  
Colocasia Esculenta ◽  
Chicken Meat ◽  
Curve Analysis ◽  
Chemical Preservatives ◽  
Kill Curve ◽  
Time Kill

Chicken meat is one of the most consumed animal products worldwide. It is a favourable medium for bacterial growth due to its high moisture content and nitrogenous compounds. The growth of foodborne pathogens in food products can cause food poisoning and foodborne illness. Chemical preservatives act to restrict microbial growth which causes deterioration and spoilage of chicken meat and chicken meat products. Chemical preservatives, however, are not preferred nowadays due to consumer perception and their residual effect on the human body. Therefore, the interest in the development of plantbased bio preservatives as a natural alternative to chemical preservatives is increasingly gaining attention. This study aimed to evaluate the antimicrobial activity of taro [Colocasia esculenta (L.) Schott] leaves extract against foodborne pathogens, including Escherichia coli ATCC 43895, Listeria monocytogenes ATCC 19112, Salmonella enterica serovar Typhimurium ATCC 14028, and Staphylococcus aureus ATCC 29737, as well as its effect on microbial population in chicken meat at different concentrations and exposure times. Taro leaves powder was extracted by maceration methods using ethanol as a solvent. The crude extract was tested for antibacterial activity by means of disc diffusion assay (DDA), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill curve analysis. The effects of the extract on microbial population were evaluated at different concentrations, exposure times and storage temperatures. The results showed the inhibition zone of the extract against tested bacterial ranged from 9.5±0.3 mm to 11.6±0.2 mm. The extract can inhibit the growth and kill the tested bacteria with MIC and MBC of 2.50 and 5.00 mg/mL, respectively. The time-kill curve analysis demonstrated that the extract can completely kill the tested bacteria at 4× MIC for 0.5 hrs. Approximately, 5% of the extract could reduce all the microbial population in chicken meat samples with an exposure time of 30 mins. The result suggested that taro leaves extract (TLE) can be integrated into the food system as a natural food preservative.

scholarly journals Antibacterial Activity of Ethanolic Extract ofSyzygium polyanthumL.(Salam)Leaves against Foodborne Pathogens and Application as Food Sanitizer

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Suzita Ramli ◽  
Son Radu ◽  
Khozirah Shaari ◽  
Yaya Rukayadi
Keyword(s):  
Antibacterial Activity ◽  
Foodborne Pathogens ◽  
Ethanolic Extract ◽  
Inhibition Zone ◽  
Antimicrobial Activities ◽  
Disk Diffusion Test ◽  
E Coli ◽  
Natural Microflora ◽  
Kill Curve ◽  
Time Kill

The aim of this study was to determine antibacterial activity ofS. polyanthumL.(salam)leaves extract foodborne pathogens. All the foodborne pathogens were inhibited after treating with extract in disk diffusion test with range6.67±0.58–9.67±0.58 mm of inhibition zone. The range of MIC values was between 0.63 and 1.25 mg/mL whereas MBC values were in the range 0.63 mg/mL to 2.50 mg/mL. In time-kill curve,L. monocytogenesandP. aeruginosawere found completely killed after exposing to extract in 1 h incubation at 4x MIC. Four hours had been taken to completely killE. coli,S. aureus,V. cholerae,andV. parahaemolyticusat 4x MIC. However, the population ofK. pneumoniae,P. mirabilis,andS. typhimuriumonly reduced to 3 log CFU/mL. The treated cell showed cell rupture and leakage of the cell cytoplasm in SEM observation. The significant reduction of natural microflora in grapes fruit was started at 0.50% of extract at 5 min and this concentration also was parallel to sensory attributes acceptability where application of extract was accepted by the panellists until 5%. In conclusion,S. polyanthumextract exhibits antimicrobial activities and thus might be developed as natural sanitizer for washing raw food materials.

scholarly journals In vitro antimicrobial combination testing of and evolution of resistance to the first-in-class spiropyrimidinetrione zoliflodacin combined with six therapeutically relevant antimicrobials for Neisseria gonorrhoeae

2019 ◽  
Vol 74 (12) ◽  
pp. 3521-3529 ◽  
Author(s):  
Sunniva Foerster ◽  
George Drusano ◽  
Daniel Golparian ◽  
Michael Neely ◽  
Laura J V Piddock ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Single Agent ◽  
Curve Analysis ◽  
Phase Iii ◽  
Transmitted Infection ◽  
Kill Curve ◽  
Time Kill ◽  
Selection Of ◽  
Selection Of Resistance

Abstract Objectives Resistance in Neisseria gonorrhoeae to all gonorrhoea therapeutic antimicrobials has emerged. Novel therapeutic antimicrobials are imperative and the first-in-class spiropyrimidinetrione zoliflodacin appears promising. Zoliflodacin could be introduced in dual antimicrobial therapies to prevent the emergence and/or spread of resistance. We investigated the in vitro activity of and selection of resistance to zoliflodacin alone and in combination with six gonorrhoea therapeutic antimicrobials against N. gonorrhoeae. Methods The international gonococcal reference strains WHO F (WT) and WHO O, WHO V and WHO X (strains with different AMR profiles) were examined. Zoliflodacin was evaluated alone or combined with ceftriaxone, cefixime, spectinomycin, gentamicin, tetracycline, cethromycin or sitafloxacin in chequerboard assays, time–kill curve analysis and selection-of-resistance studies. Results Zoliflodacin alone or in combination with all six antimicrobials showed rapid growth inhibition against all examined strains. The time–kill curve analysis indicated that tetracycline or cethromycin combined with zoliflodacin can significantly decrease the zoliflodacin kill rate in vitro. The frequency of selected zoliflodacin-resistance mutations was low when evaluated as a single agent and further reduced for all antimicrobial combinations. All resistant mutants contained the GyrB mutations D429N, K450T or K450N, resulting in zoliflodacin MICs of 0.5–4 mg/L. Conclusions Zoliflodacin, alone or in combination with sexually transmitted infection therapeutic antimicrobials, rapidly kills gonococci with infrequent resistance emergence. Zoliflodacin remains promising for gonorrhoea oral monotherapy and as part of dual antimicrobial therapy with low resistance emergence potential. A Phase III trial evaluating efficacy and safety of zoliflodacin for uncomplicated gonorrhoea treatment is planned in 2019.

scholarly journals Antibacterial Properties of Essential Oil (EO) Extracted from Nigella sativa Linn. (Black cumin) and its Application Against Vibrio cholerae in Ground Chicken Meat

2019 ◽  
Vol 34 (2) ◽  
pp. 55-60
Author(s):  
Sharmina Deloer ◽  
ML Bari ◽  
Md Mahfuzul Hoque
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Essential Oil ◽  
Vibrio Cholerae ◽  
Chicken Meat ◽  
Optimum Temperature ◽  
Black Cumin ◽  
E Coli ◽  
Chemical Preservatives

Chemical preservatives for food preservation at high concentration are hazardous for public health. The natural antimicrobials from plants, herbs and spices have been given priority as alternatives of the chemical preservatives. In this study, antibacterial activity of the essential oil (3%) from black cumin seeds was tested against five food borne pathogens viz Staphylococcus aureus (ATCC 25923), Shigella dysenteriae-I (MJ-84), Escherichia coli 0157:H7 (ATCC 12079), Escherichia coli (ATCC 25922) and Vibrio cholerae( ATCC 6395) using disc diffusion method. The essential oil (EO) showed antibacterial activity against both Gram positive and Gram negative bacteria with the highest inhibition against S. aureus (17.4 ± 0.2) and the lowest against Vibrio cholerae (14.5 ± 1.0). No activity was observed against E. coli and E. coli O157:H7. The effect of temperature and pH on the antibacterial activity of the EO from black cumin seeds was determined. At 100°C for 30 min treatment, no significant reduction of antibacterial activity of the EO was observed, suggesting that high temperature does not affect the activity. The optimum temperature for the activity was recorded at 50°C. The EO showed the highest activity at pH 7.0 (optimum) with an insignificant change of activity at pH 5.0, 9.0 and 10.0. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of EO against S. aureus, V. cholerae and Shigella dysenterae were determined by two fold dilution method at optimum temperature of 50°C and 37oC and optimum pH at 7.0 and 5.0, respectively, which ranged from 0.125 (S. aureus) to 1.0% (Shigella dysenterae), with the MBC of 0.25 to 2.0%, respectively. Three times of MIC value of EO (1.5%) was applied in ground chicken meat seeded with V. cholerae ATCC 6395 and was kept at -20°C for 10 days. The test organism was diminished within 24 hours, suggesting that the EO from black cumin is highly active in vivo and could be used as preservative in ground chicken meat. The results of this study provide new dimension of research on EOs from spices against foodborne pathogens in vivo in controlling their growth in meat based food and food products. Bangladesh J Microbiol, Volume 34 Number 2 December 2017, pp 55-60

Potential Antibacterial Activity of Yemeni Sidr Honey Against Pseudomonas aeruginosa and Streptococcus pyogenes

2021 ◽  
Vol 19 ◽  
Author(s):  
Mohammad A. Al-kafaween ◽  
Abu Bakar Mohd Hilmi ◽  
Hamid A. Nagi Al-Jamal ◽  
Rania M. Al-Groom ◽  
Nour A. Elsahoryi ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Growth Curves ◽  
Cell Number ◽  
Sem Analysis ◽  
Dilution Method ◽  
Microbial Infection ◽  
Log Reduction ◽  
Kill Curve ◽  
Time Kill

Background: Sidr honey has been reported to exhibit antimicrobial activity against numerous pathogenic bacteria making this honey a promising functional food for the treatment of wounds or stomach ulcers. Objective: The purpose of this study was to investigate the effect of Sidr honey against P. aeruginosa and S. pyogenes. Methods: Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) for Sidr honey were determined by the broth dilution method. The growth curve of both bacteria with MIC, half-MIC and quarter-MIC were monitored by optical density (at OD570). The time-kill curve was used to determine the bacteriostatic and bactericidal activity of Sidr honey on both bacteria by plotting colony forming unit (CFUs) versus time. The effect of Sidr honey on the ultrastructure of the P. aeruginosa and S. pyogenes was investigated using scanning electron microscopy (SEM). The effect of Sidr honey on the expression of virulence genes in both bacteria was determined using quantitative reverse transcription polymerase chain reaction (RT-qPCR). Results: The results showed that Sidr honey possessed the lowest MIC value against P. aeruginosa and S. pyogenes with 12.5 % (w/v) and 20 % (w/v) respectively. In addition, the MBC value for Sidr honey was found to be 20% (w/v) and 25% (w/v) against P. aeruginosa and S. pyogenes respectively. Growth curves conducted with MIC Sidr honey resulted in no growth of P. aeruginosa and S. pyogenes. Growth curves with half-MIC Sidr honey resulted in a reduced growth rate and reduction in overall cell number in both bacteria over a period of 24 h, compared with cells grown without honey. In time-kill curve, treatment of P. aeruginosa and S. pyogenes with Sidr honey for 8 hours resulted in decreases of 4-log reduction (P < 0.05) in total viable counts (TVCs). SEM analysis revealed that there were marked changes in the bacterial cell morphology for both bacteria following treatment with Sidr honey. These changes included the appearance of irregular shapes, incomplete cell division, and swelling cells. The RT-qPCR results showed that the expression of algD, oprF, fleN, fleQ, fleR, fliA, and fliC in P. aeruginosa decreased 0.43-fold, 0.38-fold, 0.41-fold, 0.51-fold, 0.40-fold, 0.61-fold, and 0.39-fold respectively after exposure to Sidr honey. Meanwhile the expression of sof, sfbl, and scpA in S. pyogenes decreased 0.18-fold, 0.21-fold, and 0.28-fold respectively after treated with Sidr honey. Conclusion: Using varying methods to evaluate the planktonic integrity, this study demonstrated that Sidr honey has antibacterial activity against both bacteria and has potential as a therapeutic agent for microbial infection particularly against these two organisms. To our knowledge, this study is the first to indicate that Sidr honey is effective at inducing cell lysis and identify targets genes, at the genetic level, that might be involved in this process.

scholarly journals Antibacterial activity of selected varieties of Malaysian honey against Escherichia coli: A comparative study

10.3823/854 ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad A. Alkafaween ◽  
Hamid A. Nagi Al-Jamal ◽  
Abu Bakar Mohmd Hilmi
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Expression Profiles ◽  
E Coli ◽  
Log Reduction ◽  
Qpcr Analysis ◽  
Acacia Honey ◽  
Kill Curve ◽  
Time Kill ◽  
Tualang Honey

Background: The purpose of this study was to investigate antibacterial activity of three varieties of Malaysian honey; Tualang honey (TH), Gelam honey (GH), and Acacia honey (AH) against Escherichia coli. Methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the honey samples against E. coli were determined by the broth microdilution assay in the presence and absence of catalase enzyme. The mode of inhibition of honey samples against E. coli was investigated by the effect of time on viability. Impacts of the honeys on the expression profiles of the selected genes of E. coli were examined using RT-qPCR analysis. Results: The results showed that TH and GH honey possessed lowest MIC and MBC values against E. coli with 20% and 25% (w/v) respectively. Highest MIC and MBC values were observed by AH honey against E. coli with 25% (w/v) and 50% (w/v) values respectively. Among the tested honeys, TH and GH exhibited the highest total antibacterial activity and the highest levels of peroxide-dependent activity. Time–kill curve demonstrated a bactericidal rather than a bacteriostatic effect; with a 2-log reduction estimated within 540 min. Viable cells were not recovered after 9 hours exposure to MIC of all honey-treated. The RT-qPCR analysis showed that all honey-treated cells share a similar overall pattern of gene expression, with a trend toward reduced expression of the virulence genes of interest. Conclusion: This study demonstrates that Malaysian honey have the potential to be effective inhibitor and virulence modulator of E. coli via multiple molecular targets.

scholarly journals Antibacterial activity of taro (Colocasia esculenta L.) leaves extracts against Staphylococcus aureus and Vibrio parahaemolyticus and its effect on microbial population in sardine (Sardinella longiceps Val.)

Food Research ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 88-97
Author(s):  
K.N.M. Padzil ◽  
N.M. Ayob ◽  
A.M. Alzabt ◽  
Y. Rukayadi
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Vibrio Parahaemolyticus ◽  
Microbial Population ◽  
Inhibition Zone ◽  
Colocasia Esculenta ◽  
Plate Count ◽  
Time Curve ◽  
Total Plate Count ◽  
Diffusion Assay

Colocasia esculenta L. which is popularly known in Malaysia as ‘‘keladi’’ has extensive traditional uses for certain of the plant part such as the leaves, corm and stem. An earlier study has reported on the analysis of its pharmacological properties such as antiinflammatory and antibacterial activity. This study aimed to determine the antibacterial activity of C. esculenta L. leaves extracts against Staphylococcus aureus ATCC 29737 and Vibrio parahaemolyticus ATCC 17802 and its effect on the microbial population of sardine. The extract was tested for antibacterial activity against S. aureus and V. parahaemolyticus in term of disc diffusion assay (DDA), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and killing time curve by using Clinical and Laboratory Standard Institute (CLSI) methods. DDA assay of the extract resulted in 8.40±0.10 mm and 8.20±0.16 mm of inhibition zone of the extract on S. aureus and V. parahaemolyticus, respectively. The extract can inhibit the growth of S. aureus and V. parahaemolyticus with MICs values of 1.25±0.00 and 0.31±0.00 mg/mL and can kill the bacteria with MBCs values of 2.50±0.00 and 0.63±0.00 mg/mL, respectively. The killing time analyses showed that the S. aureus and V. parahaemolyticus can be killed completely for 4 hrs at 2 × MIC (25.0 mg/mL) and 2 × MIC (6.25 mg/mL), respectively. Application of the extract on sardine samples shows significant reduction in total plate count (TPC), S. aureus and V. parahaemolyticus count after treated with 5.00% of the extract and stored at 4˚C for 30 mins. Based on the findings, it indicates that C. esculenta L. can be listed as one of the alternatives natural sanitiser or preservative agent to reduce the bacterial loading of raw sardine prior to cooking

scholarly journals In Vitro Antibacterial Activity of Vertilmicin and Its Susceptibility to Modifications by the Recombinant AAC(6′)-APH(2″) Enzyme

2008 ◽  
Vol 52 (11) ◽  
pp. 3875-3882 ◽  
Author(s):  
Cong-Ran Li ◽  
Xin-Yi Yang ◽  
Ren-Hui Lou ◽  
Wei-Xin Zhang ◽  
Yue-Ming Wang ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Staphylococcus Epidermidis ◽  
Minimum Bactericidal Concentration ◽  
Resistant Bacteria ◽  
In Vitro Antibacterial Activity ◽  
Curve Determination ◽  
Resistant Strains ◽  
Kill Curve ◽  
Time Kill

ABSTRACT Vertilmicin is a new semisynthetic aminoglycoside with a structure similar to that of netilmicin except for a methyl group at the C-6′ position. In the present study, the in vitro antibacterial activity of vertilmicin was studied, and its susceptibility to modifications by the recombinant aminoglycoside bifunctional modifying enzyme AAC(6′)-APH(2″) was compared with those of verdamicin and netilmicin. A total of 1,185 clinical isolates collected from hospitals in Beijing between 2000 and 2001 were subjected to the in vitro antibacterial activity evaluations, including MIC, minimum bactericidal concentration (MBC), and time-kill curve tests. The MICs were evaluated in non-gentamicin-resistant (gentamicin-susceptible and gentamicin-intermediate) strains and gentamicin-resistant strains, respectively. For most of the non-gentamicin-resistant bacteria (except for the isolates of Pseudomonas spp.), the MIC90s of vertilmicin were in the range of 0.5 to 8 μg/ml, comparable to those of the reference aminoglycosides. For the gentamicin-resistant isolates, the three semisynthetic aminoglycosides (vertilmicin, netilmicin, and amikacin) demonstrated low MIC50s and/or MIC90s, as well as high percent susceptibility values. Among the study drugs, vertilmicin showed the lowest MIC90s, 16 μg/ml, for the gram-positive gentamicin-resistant isolates of Staphylococcus aureus and Staphylococcus epidermidis. Meanwhile, vertilmicin was a potent bactericidal agent, with MBC/MIC ratios in the range of 1 to 2 for Escherichia coli, Klebsiella pneumoniae, and S. aureus and 1 to 4 for S. epidermidis. The time-kill curve determination further demonstrated that this effect was rapid and concentration dependent. In evaluations of susceptibility to modifications by the recombinant AAC(6′)-APH(2″) with maximum rate of metabolism/Km measurements, vertilmicin exhibited susceptibilities to both acetylation and phosphorylation lower than those of netilmicin and verdamicin.

scholarly journals Combination Therapy of Sophoraflavanone B against MRSA:In VitroSynergy Testing

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Su-Hyun Mun ◽  
Ok-Hwa Kang ◽  
Dae-Ki Joung ◽  
Sung-Bae Kim ◽  
Yun-Soo Seo ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Multidrug Resistant ◽  
Antibacterial Drug ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Kill Curve ◽  
Time Kill

Sophoraflavanone B (SPF-B), a known prenylated flavonoid, was isolated from the roots ofDesmodium caudatum. The aim of this study was to determine the antimicrobial synergism of SPF-B combined with antibiotics against methicillin-resistantStaphylococcus aureus(MRSA). MRSA, a multidrug-resistant pathogen, causes both hospital- and community-acquired infections worldwide. The antimicrobial activity of SPF-B was assessed by the broth microdilution method, checkerboard dilution test, and time-kill curve assay. The MIC of SPF-B for 7 strains ofS. aureusranges from 15.6 to 31.25 μg/mL determined. In the checkerboard method, the combinations of SPF-B with antibiotics had a synergistic effect; SPF-B markedly reduced the MICs of theβ-lactam antibiotics: ampicillin (AMP) and oxacillin (OXI); aminoglycosides gentamicin (GET); quinolones ciprofloxacin (CIP) and norfloxacin (NOR) against MRSA. The time-kill curves assay showed that a combined SPF-B and selected antibiotics treatment reduced the bacterial counts below the lowest detectable limit after 24 h. These data suggest that the antibacterial activity of SPF-B against MRSA can be effectively increased through its combination with three groups of antibiotics (β-lactams, aminoglycosides, and quinolones). Our research can be a valuable and significant source for the development of a new antibacterial drug with low MRSA resistance.

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