scholarly journals Antimicrobial Activity of Six International Artisanal Kefirs against Bacillus cereus, Listeria monocytogenes, Salmonella enterica Serovar Enteritidis, and Staphylococcus aureus

2020 ◽  
Vol 8 (6) ◽  
pp. 849 ◽  
Author(s):  
Abrar Sindi ◽  
Md. Bahadur Badsha ◽  
Barbara Nielsen ◽  
Gülhan Ünlü

Kefir, a fermented dairy beverage, exhibits antimicrobial activity due to many metabolic products, including bacteriocins, generated by lactic acid bacteria. In this study, the antimicrobial activities of artisanal kefir products from Fusion Tea (A), Britain (B), Ireland (I), Lithuania (L), the Caucuses region (C), and South Korea (K) were investigated against select foodborne pathogens. Listeria monocytogenes CWD 1198, Salmonella enterica serovar Enteritidis ATCC 13076, Staphylococcus aureus ATCC 25923, and Bacillus cereus ATCC 14579 were inhibited by artisanal kefirs made with kefir grains from diverse origins. Kefirs A, B, and I inhibited all bacterial indicator strains examined at varying levels, except Escherichia coli ATCC 12435 (non-pathogenic, negative control). Kefirs K, L, and C inhibited all indicator strains, except S. aureus ATCC 25923 and E. coli ATCC 12435. Bacteriocins present in artisanal kefirs were determined to be the main antimicrobials in all kefirs examined. Kefir-based antimicrobials are being proposed as promising natural biopreservatives as per the results of the study.

Author(s):  
Hasan Ellahi ◽  
Elham Khalili Sadrabad ◽  
Seyed Hossein Hekmatimoghaddam ◽  
Ali Jebali ◽  
Jalal Sadeghizadeh-yazdi ◽  
...  

Background: Staphylococcus aureus, Salmonella enterica, Escherichia Coli (E. Coli) and Listeria monocytogenes are considered as important foodborne pathogens. Pistachia atlantica sub sp. Kurdica, called wild pistachio, has been known as an antimicrobial compound. The aim of this study was to determine the antimicrobial activity and chemical composition of this essential oil (EO) on some of foodborne pathogens. Methods: The EO of Pistachia atlantica was obtained by hydro-distillation and analyzed by GC-MASS. The antibacterial effects of Pistachia atlantica were evaluated at two concentrations of 10 and 15 µL against Staphylococcus aureus, E. Coli, Salmonella enterica, and Listeria monocytogenes using disk diffusion method. The analysis was done by SPSS. Results: In the current study, α-pinene (92.5%) and ß-pinene (1.62%) were the main components of Pistachia atlantica EO. The EO was most effective on Salmonella enterica, whereas, its effect on Listeria monocytogenes was the weakest. The results showed a significant difference in reducing Salmonella enterica in comparison to others (P < 0.05). Conclusion: The EO has inhibitory effects on the studied bacteria. Therefore, this EO can be used as a natural preservative to extend the shelf life of foods.


Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 906
Author(s):  
Bokyung Son ◽  
Minsuk Kong ◽  
Yoyeon Cha ◽  
Jaewoo Bai ◽  
Sangryeol Ryu

Bacteriophage endolysins have attracted attention as promising alternatives to antibiotics, and their modular structure facilitates endolysin engineering to develop novel endolysins with enhanced versatility. Here, we constructed hybrid proteins consisting of two different endolysins for simultaneous control of two critical foodborne pathogens, Staphylococcus aureus and Bacillus cereus. The full-length or enzymatically active domain (EAD) of LysB4, an endolysin from the B. cereus-infecting phage B4, was fused to LysSA11, an endolysin of the S. aureus-infecting phage SA11, via a helical linker in both orientations. The hybrid proteins maintained the lytic activity of their parental endolysins against both S. aureus and B. cereus, but they showed an extended antimicrobial spectrum. Among them, the EAD of LysB4 fused with LysSA11 (LysB4EAD-LyaSA11) showed significantly increased thermal stability compared to its parental endolysins. LysB4EAD-LysSA11 exhibited high lytic activity at pH 8.0–9.0 against S. aureus and at pH 5.0–10.0 against B. cereus, but the lytic activity of the protein decreased in the presence of NaCl. In boiled rice, treatment with 3.0 µM of LysB4EAD-LysSA11 reduced the number of S. aureus and B. cereus to undetectable levels within 2 h and also showed superior antimicrobial activity to LyB4EAD and LysSA11 in combination. These results suggest that LysB4EAD-LysSA11 could be a potent antimicrobial agent for simultaneous control of S. aureus and B. cereus.


2008 ◽  
Vol 71 (2) ◽  
pp. 325-332 ◽  
Author(s):  
YONG-SUK KIM ◽  
ZIAN-BIN ZHENG ◽  
DONG-HWA SHIN

Kimchi is a unique Korean traditional vegetable product that is fermented by lactic acid bacteria (LAB) and is mainly consumed as a side dish with boiled rice. Its main ingredients are brined Chinese cabbage, red pepper powder, and fermented fish sauce, and these are combined with many spices such as garlic, green onion, ginger, and some seaweed. The relationship between the concentration of LAB or the pH and the growth of three gram-positive foodborne pathogens (Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus) was evaluated. Heat treatment (HT; 85°C for 15 min) or neutralization treatment (NT; pH 7.0) was conducted on day 0 (0-D group) and day 3 (3-D group) of incubation. The pH in the control group and the NT group dropped sharply to 4.12 to 4.30 after 2 days of incubation and slightly decreased thereafter, whereas the pH in the control group and HT group stayed at 7.0 during incubation. LAB were not detected in the HT kimchi during incubation. B. cereus in the NT-0-D, NT-3-D, and HT-3-D groups was reduced by 1.5 to 3.1 log CFU/ml but increased slightly in the HT-0-D group. L. monocytogenes in HT-3-D and NT-3-D groups disappeared after 5 days of incubation, and S. aureus in the NT-0-D group disappeared after 4 days. These findings indicate that growth of all the foodborne pathogens was inhibited by NT-0-D, HT-3-D, and NT-3-D, but B. cereus was not inhibited by HT-0-D. Thus, growth of LAB in kimchi is an important factor in the control of foodborne pathogens.


2020 ◽  
Vol 41 (1) ◽  
pp. 3
Author(s):  
Flavia Debiagi ◽  
Renata K.T. Kobayashi ◽  
Gerson Nakazato ◽  
Luciano Aparecido Panagio ◽  
Suzana Mali

A preferência mundial para alimentos mais saudáveis e livres de aditivos químicos pelos consumidores, associada ao aumento da resistência bacteriana, resultaram na necessidade de medidas alternativas no setor de alimentos. Os óleos correspondem a antimicrobianos naturais e constituem uma classe emergente como substitutos dos produtos químicos sintéticos na conservação de alimentos. O objetivo deste trabalho foi avaliar a atividade antimicrobiana de óleos essenciais de orégano (OEO) e cravo (CEO ) frente a bactérias, fungos e leveduras de importância no setor de alimentos. OEO e CEO foram avaliados in natura (IN) e após processamento térmico (TP) a 120 o C por 5 minutos. Para avaliar a atividade antimicrobiana frente a cada microrganismo empregou-se o método de discodifusão e o teste de microdiluição em caldo (MIC). Tanto o OEO quanto o CEO apresentaram zonas de inibição semelhantes para amostras IN e TP, indicando que a atividade antimicrobiana desses óleos são resistentes a altas temperaturas. Os microrganismos mais sensíveis para ambos os óleos essenciais foram os fungos (Aspergillus niger, Penicillium citrinum e Candida albicans), seguidos por Staphylococcus aureus, Bacillus cereus e Staphylococcus aureus resistente à meticilina (MRSA). Já as cepas Streptococcus mutans e Enterococcus faecalis apresentaram uma maior resistência frente à atividade antimicrobiana dos óleos essenciais. Em geral, os maiores halos de inibição e menores valores de MIC foram obtidos quando empregado o OEO, sugerindo uma maior atividade microbiana do mesmo quando comparado ao CEO


2019 ◽  
Vol 8 (4) ◽  
Author(s):  
Francesca Pedonese ◽  
Giada Verani ◽  
Beatrice Torracca ◽  
Barbara Turchi ◽  
Antonio Felicioli ◽  
...  

Propolis antimicrobial activity has been limitedly studied in food, particularly in dairy products. We studied the antimicrobial activity of an alcoholic extract of an Italian propolis in sterile skim milk, pasteurized cow’s milk, and cow’s and goat’s whey cheese (ricotta). Following the determination of the minimal inhibitory concentration on Gram+ and Gram- bacteria, the extract was employed at 2 and 5% (P2, P5), using controls with the same ethanol concentrations (E2, E5) and without any addition. In milk trials, Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, and Pseudomonas fluorescens were tested. P2 and P5 samples registered significant decreases of Gram+ bacteria in skim milk. The same was true for P5 in cows’ milk, but only with S. aureus for P2. Ricotta was inoculated with L. monocytogenes, S. aureus and B. cereus and stored at 8.5°C. In cow’s milk ricotta, L. monocytogenes counts in P5 were always lower than control during the storage time, significantly so from the 14th day. In goat’s ricotta, L. monocytogenes counts in P5 were at least one logarithm lower than E5, whereas the extract didn’t show a significant effect on S. aureus and B. cereus. The antimicrobial activity of propolis, particularly on L. monocytogenes, could be employed in ready-to-eat refrigerated dairy products.


2003 ◽  
Vol 58 (11-12) ◽  
pp. 850-854 ◽  
Author(s):  
Ayşen Özdemir Türk ◽  
Meral Yılmaz ◽  
Merih Kıvanç ◽  
Hayrettin Türk

Abstract In this study, the antimicrobial activity of the acetone, diethyl ether and ethanol extracts of the lichen Cetraria aculeata has been investigated. The extracts were tested against twelve bacteria and eight fungi and found active against Escherichia coli, Staphylococcus aureus, Aeromonas hydrophila, Proteus vulgaris, Streptococcus faecalis, Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa, Listeria monocytogenes. No antimicrobial activity against the fungi was detected. It was determined that only one substance in the extracts has antimicrobial activity and it was characterized as protolichesterinic acid. The MICs of the extracts and protolichesterinic acid were also determined.


1997 ◽  
Vol 60 (3) ◽  
pp. 272-275 ◽  
Author(s):  
VIJAY K. JUNEJA ◽  
OSCAR P. SNYDER ◽  
BENNE S. MARMER

The ability of 16 foodborne pathogens, representative of 5 different species, to grow during cooling of previously sterilized cooked beef was studied to determine a safe cooling rate. Auto-claved ground beef samples (3 g) were inoculated with heat-shocked spores of Bacillus cereus (strain BH 86) or Clostridium botulinum (nonproteolytic type B strains CBW 25, 17B, and KAP B5 and type E strains Whitefish, Saratoga, and Alaska) or vegetative cells of Listeria monocytogenes (strains HO-VJ-S, V-7, and Scott A), Staphylococcus aureus (strains 196E, B121, and B 124), or Salmonella serotypes (S. dublin, S. enteritidis, and S. typhimurium), vacuum-packaged, and cooked in a stirred water bath to an internal temperature of 60°C in I h. In some experiments combinations of C. botulinum and B. cereus spores or S. aureus and salmonellae vegetative cells were used. Heated samples were cooled through the temperature range of 54.4 to 7.2°C at rates varying from 6 to 21 h. Samples were removed at various times during cooling to determine if growth of the pathogens had occurred. No growth was observed with cooling periods of up to 21h. This study with the model meat system (3 g autoclaved ground beef inoculated with selected pathogens and then pasteurized) indicated that cooling from 52.4 to 7.2°C in up to 21 h would not pose a food safety hazard from growth of these pathogens.


2009 ◽  
Vol 72 (8) ◽  
pp. 1654-1659 ◽  
Author(s):  
PILAR MARTINEZ VIEDMA ◽  
HIKMATE ABRIOUEL ◽  
NABIL BEN OMAR ◽  
ROSARIO LUCAS LÓPEZ ◽  
EVA VALDIVIA ◽  
...  

Enterocin AS-48 was tested against Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes in different kinds of desserts. The highest activity against S. aureus was detected in baker cream. However, in yogurt-type soy-based desserts and in gelatin pudding, AS-48 (175 arbitrary units [AU]/g) reduced viable cell counts of S. aureus by only 1.5 to 1.8 log units at most. The efficacy of AS-48 in puddings greatly depended on inoculum size, and viable S. aureus counts decreased below detection levels within 24 h for inocula lower than 4 to 5.5 log CFU/g. For L. monocytogenes, bacteriocin concentrations of 52.5 to 87.5 AU/g reduced viable counts below detection levels and avoided regrowth of survivors. The lowest activity was detected in yogurt-type desserts. For B. cereus, viable cell counts were reduced below detection levels for bacteriocin concentrations of 52.5 AU/g in instant pudding without soy or by 175 AU/g in the soy pudding. In gelatin pudding, AS-48 (175 AU/g) reduced viable cell counts of B. cereus below detection levels after 8 h at 10°C or after 48 h at 22°C. Bacteriocin addition also inhibited gelatin liquefaction caused by the proteolytic activity of B. cereus.


Molekul ◽  
2017 ◽  
Vol 12 (2) ◽  
pp. 166
Author(s):  
Soerya Dewi Marliyana ◽  
Didin Mujahidin ◽  
Yana M Syah ◽  
Yaya Rukayadi

Time–kill assay was performed for 4-hydroxypanduratin A that was isolated from Kaempferia pandurata rizhome against four important foodborne pathogens, namely Bacillus cereus ATCC 21772, Bacillu subtilis ATCC 6633, Staphylococcus aureus ATCC 29737,  and  Proteus mirabilis ATCC 21100. The methods have been investigated in term of Minimum Inhibitory Concentration (MIC) and killing time curve using methods of Clinical and Laboratory Standards Institute (CLSI) guidelines. The results showed that 4-hydroxypanduratin A rapid acting in killing bacteria as follow: B. cereus : 1×MIC for 4 h, P. mirabilis: 4×MIC for 0.5 h, meanwhile  B. subtilis and S. aureus were 1×MIC for 2 h. In conclusion, 4-hydroxypanduratin A showed strong antimicrobial activity against four important foodborne pathogens.


2019 ◽  
Vol 82 (10) ◽  
pp. 1802-1814 ◽  
Author(s):  
SANDRINE GUILLOU ◽  
JEANNE-MARIE MEMBRÉ

ABSTRACT High hydrostatic pressure processing (HPP) is a mild preservation technique, and its use for processing foods has been widely documented in the literature. However, very few quantitative synthesis studies have been conducted to gather and analyze bacterial inactivation data to identify the mechanisms of HPP-induced bacterial inactivation. The purpose of this study was to conduct a quantitative analysis of three-decimal reduction times (t3δ) from a large set of existing studies to determine the main influencing factors of HPP-induced inactivation of three foodborne pathogens (Listeria monocytogenes, Staphylococcus aureus, and Salmonella enterica) in various foods. Inactivation kinetics data sets from 1995 to 2017 were selected, and t3δ values were first estimated by using the nonlinear Weibull model. Bayesian inference was then used within a metaregression analysis to build and test several models and submodels. The best model (lowest error and most parsimonious) was a hierarchical mixed-effects model including pressure intensity, temperature, study, pH, species, and strain as explicative variables and significant factors. Values for t3δ and ZP associated with inactivation under HPP were estimated for each bacterial pathogen, with their associated variability. Interstudy variability explained most of the variability in t3δ values. Strain variability was also important and exceeded interstudy variability for S. aureus, which prevented the development of an overall model for this pathogen. Meta-analysis is not often used in food microbiology but was a valuable quantitative tool for modeling inactivation of L. monocytogenes and Salmonella in response to HPP treatment. Results of this study could be useful for refining quantitative assessment of the effects of HPP on vegetative foodborne pathogens or for more precisely designing costly and labor-intensive experiments with foodborne pathogens.


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