scholarly journals Internalisation potential of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium and Staphylococcus aureus in lettuce seedlings and mature plants

2013 ◽  
Vol 11 (2) ◽  
pp. 210-223 ◽  
Author(s):  
Taryn-Ann Standing ◽  
Erika du Plessis ◽  
Stacey Duvenage ◽  
Lise Korsten
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
Escherichia Coli O157 ◽  
Human Pathogens ◽  
Serovar Typhimurium ◽  
Staphylococcus Hominis ◽  
Hydroponically Grown

The internalisation potential of Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7 and Salmonella enterica subsp. enterica serovar Typhimurium in lettuce was evaluated using seedlings grown in vermiculite in seedling trays as well as hydroponically grown lettuce. Sterile distilled water was spiked with one of the four human pathogenic bacteria (105 CFU/mL) and used to irrigate the plants. The potential for pathogen internalisation was investigated over time using light microscopy, transmission electron microscopy and viable plate counts. Additionally, the identities of the pathogens isolated from internal lettuce plant tissues were confirmed using polymerase chain reaction with pathogen-specific oligonucleotides. Internalisation of each of the human pathogens was evident in both lettuce seedlings and hydroponically grown mature lettuce plants. To our knowledge, this is the first report of S. aureus internalisation in lettuce plants. In addition, the levels of background microflora in the lettuce plants were determined by plate counting and the isolates identified using matrix-assisted laser ionisation–time of flight (MALDI–TOF). Background microflora assessments confirmed the absence of the four pathogens evaluated in this study. A low titre of previously described endophytes and soil inhabitants, i.e., Enterobacter cloacae, Enterococcus faecalis, Lysinibacillus fusiformis, Rhodococcus rhodochrous, Staphylococcus epidermidis and Staphylococcus hominis were identified.

scholarly journals ATIVIDADE ANTIMICROBIANA DE MICRORGANISMOS ISOLADOS DE GRÃOS DE KEFIR

2018 ◽  
Vol 19 (0) ◽  
Author(s):  
Priscila Alves Dias ◽  
Daiani Teixeira Silva ◽  
Cláudio Dias Timm
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Salmonella Enterica ◽  
Escherichia Coli O157 ◽  
E Coli

Resumo Kefir é o produto da fermentação do leite pelos grãos de kefir. Esses grãos contêm uma mistura simbiótica de bactérias e leveduras imersas em uma matriz composta de polissacarídeos e proteínas. Muitos benefícios à saúde humana têm sido atribuídos ao kefir, incluindo atividade antimicrobiana contra bactérias Gram positivas e Gram negativas. A atividade antimicrobiana de 60 microrganismos isolados de grãos de kefir, frente à Escherichia coli O157:H7, Salmonella enterica subsp. enterica sorotipos Typhimurium e Enteritidis, Staphylococcus aureus e Listeria monocytogenes, foi estudada através do teste do antagonismo. A ação antimicrobiana dos sobrenadantes das bactérias ácido-lácticas que apresentaram atividade no teste do antagonismo foi testada. O experimento foi repetido usando sobrenadantes com pH neutralizado. Salmonella Typhimurium e Enteritidis sobreviveram por 24 horas no kefir em fermentação. E. coli O157:H7, S. aureus e L. monocytogenes foram recuperados até 72 horas após o início da fermentação. Todos os isolados apresentaram atividade antimicrobiana contra pelo menos um dos patógenos usados no teste do antagonismo. Sobrenadantes de 25 isolados apresentaram atividade inibitória e três mantiveram essa atividade com pH neutralizado. As bactérias patogênicas estudadas sobreviveram por tempo superior àquele normalmente utilizado para a fermentação do kefir artesanal, o que caracteriza perigo em potencial para o consumidor quando a matéria-prima não apresentar segurança sanitária. Lactobacillus isolados de grãos de kefir apresentam atividade antimicrobiana contra cepas de E. coli O157:H7, Salmonella sorotipos Typhimurium e Enteritidis, S. aureus e L. monocytogenes além daquela exercida pela diminuição do pH.

scholarly journals Attachment and Colonization by Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium, and Staphylococcus aureus on Stone Fruit Surfaces and Survival through a Simulated Commercial Export Chain

2010 ◽  
Vol 73 (7) ◽  
pp. 1247-1256 ◽  
Author(s):  
STACEY COLLIGNON ◽  
LISE KORSTEN
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Stone Fruit ◽  
Escherichia Coli O157 ◽  
Infectious Dose ◽  
E Coli ◽  
Serovar Typhimurium ◽  
And Staphylococcus Aureus

The ability of the foodborne pathogens Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium, and Staphylococcus aureus to attach, colonize, and survive on stone fruit surfaces was investigated. Fifty microliters of bacterial suspension was spot inoculated onto the sterile intact fructoplane of whole peaches and plums. Minimum time required for initial adhesion and attachment was recorded for different surface contact times. Surface colonization patterns of the four pathogens and survival under simulated commercial export conditions also were evaluated. L. monocytogenes and Salmonella Typhimurium attached immediately to stone fruit surfaces. E. coli O157:H7 and S. aureus were visibly attached after 30 s and 1 h, respectively, of direct exposure. Holding freshly harvested stone fruit at 0.5°C to simulate cold storage conditions significantly lowered the titer of E. coli O157:H7 on plums and the titers of L. monocytogenes and Salmonella Typhimurium on stone fruit. E. coli O157:H7 and L. monocytogenes at a low inoculum level and S. aureus and Salmonella Typhimurium at high and low levels did not survive the simulated export chain conditions at titers that exceeded the minimum infectious dose. However, E. coli O157:H7 and L. monocytogenes were able to survive on stone fruit surfaces when inoculated at an artificially high level. In this case, the final titer at the end of the supply chain was higher than the infectious dose. In this laboratory experiment, E. coli O157:H7, L. monocytogenes, Salmonella Typhimurium, and S. aureus at potential natural contamination levels were unable to survive simulated export conditions.

scholarly journals Escherichia coli O157:H7 Induces Stronger Plant Immunity than Salmonella enterica Typhimurium SL1344

2013 ◽  
Vol 103 (4) ◽  
pp. 326-332 ◽  
Author(s):  
Debanjana Roy ◽  
Shweta Panchal ◽  
Bruce A. Rosa ◽  
Maeli Melotto
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Pathogenic Bacteria ◽  
Plant Immunity ◽  
Stomatal Closure ◽  
Defense Responses ◽  
Control Measures ◽  
Escherichia Coli O157 ◽  
Human Pathogens ◽  
Field And Laboratory Conditions

Consumption of fresh produce contaminated with bacterial human pathogens has resulted in various, sometimes deadly, disease outbreaks. In this study, we assessed plant defense responses induced by the fully pathogenic bacteria Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium SL1344 in both Arabidopsis thaliana and lettuce (Lactuca sativa). Unlike SL1344, O157:H7 induced strong plant immunity at both pre-invasion and post-invasion steps of infection. For instance, O157:H7 triggered stomatal closure even under high relative humidity, an environmental condition that generally weakens plant defenses against bacteria in the field and laboratory conditions. SL1344 instead induced a transient stomatal immunity. We also observed that PR1 gene expression was significantly higher in Arabidopsis leaves infected with O157:H7 compared with SL1344. These results suggest that plants may recognize and respond to some human pathogens more effectively than others. Furthermore, stomatal immunity can diminish the penetration of human pathogens through the leaf epidermis, resulting in low bacterial titers in the plant apoplast and suggesting that additional control measures can be employed to prevent food contamination. The understanding of how plant responses can diminish bacterial contamination is paramount in preventing outbreaks and improving the safety of food supplies.

scholarly journals Comparison between Whatman FTA Elute Cards and Conventional Swab for the Detection of Pathogenic Enteric Bacteria Using an RT-qPCR Assay

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Na Yue ◽  
Zichao Jia
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Salmonella Enterica ◽  
Enteric Bacteria ◽  
Enteric Pathogens ◽  
Escherichia Coli O157 ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Fta Cards ◽  
And Staphylococcus Aureus

The emergence of outbreaks of foodborne illness is closely associated with food contamination caused by various enteric pathogens, such as Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica serovar Enteritidis, and Staphylococcus aureus. The control of enteric pathogens poses a challenge due to the fact that these pathogens can persist for a long period of time in the environment. The rapid detection of pathogenic organisms plays a crucial role in the prevention and identification of crises related to health, safety, and well-being. Improper sample handling and processing may influence the diagnostic efficacy and accuracy. The aim of the present study was to compare the preservation capacity for enteric bacteria between Whatman Flinders Technology Associates (FTA) cards and swabs for reverse transcription-quantitative PCR (RT-qPCR) detection. It was found that Whatman FTA cards exhibited an improved preservation capacity for five types (both laboratory and environmental strains) of enteric bacteria, including Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica serovar Enteritidis, and Staphylococcus aureus for RT-qPCR detection. Hence, Whatman FTA cards may be a suitable tool for the routine isolation of foodborne bacteria for molecular diagnosis. Therefore, the use of Whatman FTA cards for sample collection and preservation may increase sensitivity and accuracy for bacteria isolation and diagnosis.

scholarly journals Antimicrobial potential of Pediococcus acidilactici from Bekasam, fermentation of sepat rawa fish (Tricopodus trichopterus) from Banyuasin, South Sumatra, Indonesia

2019 ◽  
Vol 20 (12) ◽  
Author(s):  
Sri Melia ◽  
Endang Purwati ◽  
Yulianti Fitri Kurnia ◽  
Dhiva Rezzy Pratama
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Pathogenic Bacteria ◽  
Escherichia Coli O157 ◽  
Pediococcus Acidilactici ◽  
Antimicrobial Potential

Abstract. Melia S, Purwati E, Kurnia Y. F, Pratama D. R. 2019. Antimicrobial potential of Pediococcus acidilactici from Bekasam, fermentation of sepat rawa fish (Tricopodus trichopterus) from Banyuasin, South Sumatra, Indonesia. Biodiversitas 20: 3532-3538. This study aimed to determine the antimicrobial potential of lactic acid bacteria isolated from bekasam. Bekasam is a result of sepat rawa fermentation from Banyuasin District, South Sumatra, Indonesia. The results showed that the morphological and biochemical properties of lactic acid bacteria were Gram-positive and cocci, negative catalase and included in homofermentative groups. The biggest antimicrobial activity was shown by bekasam isolate to Escherichia coli O157: H7 (21.26 mm), followed by Staphylococcus aureus ATCC25923 (18.23 mm) and Listeria monocytogenes CFSAN004330 (5.10 mm), while diameter barriers for crude bacteriocin supernatant isolates lactic acid bacteria to Escherichia coli O157: H7, Staphylococcus aureus ATCC25923 were 14.99 mm, 17.69 mm, and Listeria monocytogenes CFSAN004330 had no antimicrobial activity at neutral pH. The results of molecular identification with 16S rRNA showed that lactic acid bacteria isolated from bekasam isolate have similarity with Pediococcus acidilactici strain PB22 that has antimicrobial potential against pathogenic bacteria and potential as bio preservatives.

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