scholarly journals Study of the Antimicrobial Potential of Bacteria found in Natural Resources

Author(s):  
Svetlana Noskova ◽  
Svetlana Ivanova ◽  
Alexander Prosekov ◽  
Lyubov Dyshlyuk ◽  
Elena Ulrikh ◽  
...  

Bacteriocins are of great interest as potential antimicrobial agents against various types of bacteria, fungi, and viruses. Isolates of microorganisms derived from natural sources were used in the current study, including lactic acid bacteria and other antagonistic microorganisms. The species of the microorganisms were determined using 16S rDNA and ITS nrDNA analyses. E. coli, S. enterica, S. aureus, P. aeruginosa, B. mycoides, A. faecalis, P. vulgaris, S. flexneri , L. monocytogenes, C. albicans, A. flavus, and P. citrinum were used as pathogenic and opportunistic strains. It was found that 11 strains of antagonistic microorganisms have significant antimicrobial activity against all pathogenic and opportunistic microorganisms. The antimicrobial properties of these microorganisms are currently under study.

2020 ◽  
Vol 8 (A) ◽  
pp. 195-202
Author(s):  
V. M. Le ◽  
L. K. Asyakina ◽  
N. S. Velichkovitch ◽  
O. V. Kozlova ◽  
I. S. Milentyeva ◽  
...  

BACKGROUND: Human infectious diseases caused by antibiotic-resistant bacterial pathogens present a serious problem for clinical medicine. Causative agents of nosocomial infections, such as Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., are the most common among them. An active search for antimicrobial agents that can effectively combat drugresistant pathogens is underway. Antimicrobial substances of bacterial origin are of particular interest. Promising sources of microorganisms with antibiotic properties are natural sources: Soil, water, plants, etc. AIM: The purpose of this work is to screen and characterize the antagonistic properties of microorganisms isolated from natural sources in connection with the creation of new pharmaceutical substances. METHODS: The material for the isolation of microorganisms was the soil, water bodies, and plant objects of various municipal districts of the Kemerovo Region. Identification of the isolated microorganisms was carried out using the methods proposed in the directory “Bergey’s Manual of Determinative Bacteriology” and in the monograph Nesterenko et al. The selection of strains from soil samples was carried out according to standard methods described in “Methods of soil microbiological control. Methodical recommendations,” cultural-morphological properties of isolates were studied using conventional microbiological methods. RESULTS: The following results are obtained: (1) Lactic acid bacteria and other microorganisms antagonists from natural sources were isolated: Soil, water bodies, and plant objects; 20 isolates were isolated, their cultural and morphological properties were studied; isolated microorganisms were found to belong presumably to the genera Bacillus, Leuconostoc, Pedio-coccus, Lactobacillus, and Bacteroides; (2) Antimicrobial properties of lactic acid bacteria and other antagonistic microorganisms isolated from natural sources on solid and liquid nutrient media were studied; (3) 12 strains of 20 isolates with maximum antimicrobial properties were selected for further studies. CONCLUSION: Further research on the biochemical properties of lactic acid bacteria and other antagonist microorganisms isolated from natural sources, the study of antibiotic resistance of lactic acid bacteria and other antagonist microorganisms isolated from natural sources, as well as other more detailed studies will be conducted with selected 12 strains with maximum antimicrobial properties.


Author(s):  
Roseline Eleojo Kwasi ◽  
Iyanuoluwa Gladys Aremu ◽  
Qudus Olamide Dosunmu ◽  
Funmilola A. Ayeni

Background: Ogi constitutes a rich source of lactic acid bacteria (LAB) with associated health benefits to humans through antimicrobial activities. However, the high viability of LAB in Ogi and its supernatant (Omidun) is essential. Aims: This study was carried out to assess the viability of LAB in various forms of modified and natural Ogi and the antimicrobial properties of Omidun against diarrhoeagenic E coli. Methods and Material: The viability of LAB was assessed in fermented Ogi slurry and Omidun for one month and also freeze-dried Ogi with and without added bacterial strains for two months. A further 10 days viability study of modified Omidun, refrigerated Omidun, and normal Ogi was performed. The antimicrobial effects of modified Omidun against five selected strains of diarrhoeagenic E. coli (DEC) were evaluated by the co-culture method. Results: Both drying methods significantly affected carotenoids and phenolic compounds. The Ogi slurry had viable LAB only for 10 days after which, there was a succession of fungi and yeast. Omidun showed 2 log10cfu/ml reduction of LAB count each week and the freeze-dried Ogi showed progressive reduction in viability. Refrigerated Omidun has little viable LAB, while higher viability was seen in modified Omidun (≥2 log cfu/ml) than normal Omidun. Modified Omidun intervention led to 2-4 log reduction in diarrhoeagenic E. coli strains and total inactivation of shigella-toxin producing E. coli H66D strain in co-culture. Conclusions: The consumption of Ogi should be within 10 days of milling using modified Omidun. There are practical potentials of consumption of Omidun in destroying E. coli strains implicated in diarrhea. Keywords: Ogi, Omidun, lactic acid bacteria, diarrhoeagenic Escherichia coli strains, Viability.


2020 ◽  
Vol 2 ◽  
pp. 00002
Author(s):  
Dyah Fitri Kusharyati ◽  
Pancrasia Maria Hendrati ◽  
Dini Ryandini ◽  
Tsani Abu Manshur ◽  
Meilany Ariati Dewi ◽  
...  

<p class="Abstract"><i>Bifidobacterium</i> is a group of Lactic Acid Bacteria (LAB) that commonly found in the gastrointestinal tract and vagina. LAB has many health benefits, such as produce an antimicrobial substance against a pathogen. This research aims to isolate <i>Bifidobacterium</i> from an infant’s feces and know its antimicrobial activity against <i>Escherichia coli</i> and <i>Candida albicans.</i> A total of 5 isolates <i>Bifidobacterium</i> spp. were isolated from the sample. <span lang="EN">The largest inhibitory activity against <i>E. coli</i> was shown by isolate Bb3F, with the inhibitory zone of 10.80 mm. While the largest inhibition activity against <i>C. albicans</i> was shown by isolate Bb1B and Bb3F with the inhibitory zone of 9.70 mm.</span><o:p></o:p></p>


2019 ◽  
Vol 9 (3) ◽  
pp. 601 ◽  
Author(s):  
Alicia Cervantes-Elizarrarás ◽  
Nelly Cruz-Cansino ◽  
Esther Ramírez-Moreno ◽  
Vicente Vega-Sánchez ◽  
Norma Velázquez-Guadarrama ◽  
...  

Probiotics can act as a natural barrier against several pathogens, such Helicobacter pylori, a bacterium linked to stomach cancer. The aim of the present study was to isolate and identify lactic acid bacteria (LAB) from pulque and aguamiel, and evaluate their probiotic potential and antimicrobial effect on Escherichia coli, Staphylococcus aureus, and Helicobacter pylori. Ten isolates were selected and evaluated for in vitro resistance to antibiotics and gastrointestinal conditions, and antimicrobial activity against E. coli and S. aureus and the effect on H. pylori strains. 16S rRNA identification was performed. Ten potential probiotic isolates were confirmed as belonging to the genera Lactobacillus and Pediococcus. All the strains were susceptible to clinical antibiotics, except to vancomycin. Sixty percent of the isolates exhibited antimicrobial activity against E. coli and S. aureus. The growth of H. pylori ATCC 43504 was suppressed by all the LAB, and the urease activity from all the H. pylori strains was inhibited, which may decrease its chances for survival in the stomach. The results suggest that LAB isolated from pulque and aguamiel could be an option to establish a harmless relationship between the host and H. pylori, helping in their eradication therapy.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Stellah Byakika ◽  
Ivan Muzira Mukisa ◽  
Robert Mugabi ◽  
Charles Muyanja

Bacterial contamination of fermented foods is a serious global food safety challenge that requires effective control strategies. This study characterized presumptive E. coli isolated from Obushera, a traditional fermented cereal beverage from Uganda. Thereafter, the antimicrobial effect of lactic acid bacteria (LAB) previously isolated from Obushera, against the E. coli, was examined. The presumptive E. coli was incubated in brain heart infusion broth (pH = 3.6) at 25°C for 48 h. The most acid-stable strains were clustered using (GTG)5 rep-PCR fingerprinting and identified using 16S rRNA sequencing. E. coli was screened for Shiga toxins (Stx 1 and Stx 2) and Intimin (eae) virulence genes as well as antibiotic resistance. The spot-on-the-lawn method was used to evaluate antimicrobial activity. Eighteen isolates were acid stable and are identified as E. coli, Shigella, and Lysinibacillus. The Stx 2 gene and antibiotic resistance were detected in some E. coli isolates. The LAB were antagonistic against the E. coli. Lactic acid bacteria from traditional fermented foods can be applied in food processing to inhibit pathogens. Obushera lactic acid bacteria could be used to improve the safety of fermented foods.


Author(s):  
ROSALINA YULIANA AYEN ◽  
ENDANG KUSDIYANTINI ◽  
SRI PUJIYANTO

Objective: This research aimed to isolate, determine the characteristics of lactic acid bacteria (LAB) of Sui Wu’u from Bajawa, Nusa Tenggara Timur and identify LAB using 16S rRNA potential as antimicrobial activity against pathogenic bacteria. Methods: Sui Wu’u which has been stored for 6 months was obtained from Bajawa district, inoculated on de Man Rogosa-Sharpe Agar (Merck) + 0.5% CaCO3, purification of LAB, characterization of selected isolates, biochemical test, tolerance test for pH, viability to test temperature, and content NaCl, determination of antimicrobial action by the agar well disk diffusion method using antibiotic (Amoxicillin) as a control and as indicator bacteria (Staphylococcus aureus and Escherichia coli) and isolation of genomic 16S rRNA; molecular identification. Results: Based on research results obtained five isolates of LAB, Gram staining the LAB isolated from Sui Wu’u showed that the isolated bacteria (bacilli and coccus) are Gram-positive, catalase-negative and the isolates have tolerance of viability at temperatures of 10°C, 45°C, and 50°C and to salinitas of 4% and 6.5%. The inhibitory zone LAB isolates (2PKT) against E. coli bacteria (20 mm) and S. aureus (12 mm), and (2PKB) against E. coli bacteria (17 mm) and S. aureus (10 mm). The two selected isolates were identified as Lactobacillus fermentum strain HB bacteria with 100% identification value and 98.93% query cover and L. fermentum strain HT with 100% identification value and 99.23% query cover. Conclusion: L. fermentum from Sui Wu’u has antibacterial activity against Staphylococcus aureus and Escherichia coli.


Food Control ◽  
2013 ◽  
Vol 32 (2) ◽  
pp. 477-483 ◽  
Author(s):  
Almudena García-Ruiz ◽  
Teresa Requena ◽  
Carmen Peláez ◽  
Begoña Bartolomé ◽  
M. Victoria Moreno-Arribas ◽  
...  

2017 ◽  
Vol 26 (2) ◽  
pp. 7
Author(s):  
Oscar Perales Pérez ◽  
Yarilyn CedeñoMattei

La dispersión de nanopartículas antibacterianas en matrices poliméricas biocompatibles, no tóxicas y biodegradables permitirá el desarrollo de materiales más eficientes y efectivos para la conservación de alimentos, la eliminación de contaminantes y la protección contra microorganismos que comprometen la salud humana. Los materiales bactericidas nanométricos tienen una relación superficie / volumen muy grande que les permite interactuar con más copias de moléculas biológicas, y por lo tanto, mejorar la eficacia antimicrobiana. Más recientemente, se ha sugerido la actividad antimicrobiana del MgO amigable con el medio ambiente y químicamente estable. La incorporación de compuestos bactericidas en una matriz polimérica puede combinar la estabilidad física proporcionada por la matriz polimérica con las propiedades antimicrobianas de los agentes antimicrobianos dispersados como partıculas pequeñas sólidas. Sobre esta base, la presente investigación se centrará en el desarrollo de mezclas de partículas inorgánicas poliméricas biocompatibles, los denominados nanocompuestos, con actividad antimicrobiana sintonizable y mejorada. Se confirmó la actividad antimicrobiana de perlas de alginato cálcico - MgO (que oscilaban entre 0% y 40% p / p MgO) contra E. coli. Las perlas que contenían 20% p / p de MgO inhibían completamente el crecimiento bacterial de la E. coli. Palabras clave.-Alginato de calcio, Cuentas porosas, Óxido de magnesio, Actividad antimicrobiana. ABSTRACTThe dispersion of antibacterial nanoparticles into bio-compatible, non-toxic and bio-degradable polymeric matrices will enable the development of more efficient and effective materials for food preservation, removal of contaminants, and protection against human health-compromising microorganisms. Nanometric bactericidal materials have a very large surface to volume ratio that enable them to attach more copies of biological molecules, and hence, enhance antimicrobial efficiency. More recently, the antimicrobial activity of environmental-friendly and chemically stable MgO has been suggested. The incorporation of bactericidal compounds into a polymeric matrix can combine physical stability provided by the polymeric matrix with the antimicrobial properties of antimicrobial agents dispersed as solid tiny particles. On this basis, the present research will be focused on the development of biocompatible polymer-inorganic particle mixtures, so-called nanocomposites, with tunable and enhanced antimicrobial activity. The antimicrobial activity of calcium alginate – MgO beads (ranging from 0% - 40% w/w MgO) against E. coli was confirmed. Beads containing 20% w/w of MgO fully inhibited the E. coli. bacterial growth.. Keywords.- Calcium alginate, Porous beads, Magnesium oxide, Antimicrobial activity.


2014 ◽  
Vol 2 ◽  
Author(s):  
Maira Urazova ◽  
Asel Moldagulova ◽  
Sandugash Anuarbekova ◽  
Altynay Tuyakova ◽  
Gulyaim Abitaeva ◽  
...  

Introduction: Bacteriocins produced by lactic acid bacteria (LAB) have the potential to cover a very broad field of applications, including the food industry and the medical sector. In the food industry, bacteriocinogenic LAB strains can be used as starter cultures, co-cultures, and bioprotective cultures, which would be used to improve food quality and safety. In the medical sector, bacteriocins of probiotic LAB might play a role in interactions, which take place in human gastrointestinal tract, and contribute to gut health. The aim of this study was the examine the effect of LAB antimicrobial activity. Methods: LAB were isolated from different commercial and home made products, such as kazy and sour cream. To screen for bacteriocin producing LAB, we used an agar diffusion bioassay, described in a previous study by Dr. Yang, with three modifications in cell-free supernatant (CFS). First we had a clear supernatant, second we adjusted the CFS to pH 6.0 to eliminate acids antimicrobial effects, and third the CFS pH 6.0 was treated with catalase to exclude the action of H2O2 and confirm action of bacteriocin-like substances. Pathogenic S.marcescens, E. coli, S.aureus cultures were used as indicators. Results: Screening of 95 strains of LAB through deferred antagonism to six indicator cultures showed that all of the selected strains had a high value of antibacterial activity. However, CFS of only 50 strains retained their antimicrobial activity, and 10 of them lost this activity in the second modification of CFS with pH 6.0 to test culture S.marcescens, which confirmed the acidic nature of antimicrobial activity of CFS. Lb.rhamnosus (P-1), Lb.fermentum (N-6), and Lc.lactis (7M) lost antibacterial activity in the presence of the catalase. All modifications of CFS of three strains: Lb.pentosus (16al), Lb.pentosus (P-2), and Pediococcusacidilactici (8) retained inhibitory activity to E.coli and S. aureus. Supernatants of only Lactococcusgarvieae (10a) and Pediococcusacidilactici (25) extracted from homemade meat food kazy (Karaganda) and sour cream (Astana), respectively retained antibacterial activity to all three indicator cultures. Conclusion: The antibacterial activity (pH 6.0, added catalase) of Lactococcusgarvieae (10a) and Pediococcusacidilactici (25) to S. marcescens, E. coli, and S.aureus indicates these strains as promising strains for further use in the preparation of bacteriocins.


2020 ◽  
Vol 83 (11) ◽  
pp. 2018-2025 ◽  
Author(s):  
SAHAR ROSHANAK ◽  
FAKHRI SHAHIDI ◽  
FARIDEH TABATABAEI YAZDI ◽  
ALI JAVADMANESH ◽  
JEBRAEIL MOVAFFAGH

ABSTRACT One of the most effective methods for increasing the antimicrobial activity of a substance is to combine it with one or more other antimicrobial agents. The aim of the present study was to evaluate the antimicrobial effect of buforin I and nisin alone and investigate the synergistic action of these compounds against the most important food spoilage microorganisms, including Bacillus subtilis, Staphylococcus epidermidis, Listeria innocua, Escherichia coli, Salmonella serovar Enteritidis, Aspergillus oryzae, Rhodotorula glutinis, and Geotrichum candidum. The results of MIC and MBC or minimum fungicidal concentration examinations showed that buforin I had higher antimicrobial activity than nisin on all microbial strains used in this study (P ≤ 0.5). E. coli was the most resistant to both antimicrobial agents, whereas L. innocua and S. epidermidis were the most sensitive to nisin and buforin I, respectively. The results of synergistic interaction between buforin I and nisin indicated that the combination of buforin I and nisin on B. subtilis, S. epidermidis, and A. oryzae showed a synergistic effect, whereas it had no effect on Salmonella serovar Enteritidis and G. candidum. The combination of buforin I and nisin showed a partial synergistic effect on L. innocua, E. coli, and R. glutinis. Assessment of viability of the microorganisms under the antimicrobial agents alone and in combination with each other at MICs and fraction inhibitory concentrations indicated that use of these antimicrobial agents in combination enhances antimicrobial activity at lower concentrations of both agents. The present study investigated the antimicrobial properties of buforin I against food spoilage microorganisms for the first time and suggests that its use alone or with nisin may provide a clear horizon for the application of antimicrobial peptides as natural preservatives. Thus, the combination of antimicrobial peptides and traditional antimicrobial food preservatives could be a promising option for the prevention of contamination, spoilage, and infestation of food and beverage products. HIGHLIGHTS


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