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The inactivation of bacterial endospores continues to be the main curtailment for further adoption of high-pressure processing in intrastate, interstate, and global food commerce. The current study investigated the effects of elevated hydrostatic pressure for the inactivation of endospore suspension of three indicator spore-forming bacteria of concern to the food industry. Additionally, the effects of four bacteriocin/bactericidal compounds were studied for augmenting the decontamination efficacy of the treatment. Elevated hydrostatic pressure at 650 MPa and at 50 °C was applied for 0 min (untreated control) and for 3, 7, and 11 min with and without 50K IU of nisin, 224 mg/L lysozyme, 1% lactic acid, and 1% CitricidalTM. The results were statistically analyzed using Tukey- and Dunnett’s-adjusted ANOVA. Under the condition of our experiments, we observed that a well-designed pressure treatment synergized with mild heat and bacteriocin/bactericidal compounds could reduce up to >4 logs CFU/mL (i.e., >99.99%) of bacterial endospores. Additions of nisin and lysozyme were able, to a great extent, to augment (p < 0.05) the decontamination efficacy of pressure-based treatments against Bacillus amyloliquefaciens and Bacillus atrophaeus, while exhibiting no added benefit (p ≥ 0.05) for reducing endospores of Geobacillus stearothermophilus. The addition of lactic acid, however, was efficacious for augmenting the pressure-based reduction of bacterial endospores of the three microorganisms.
Sadiye Aras; Niamul Kabir; Sabrina Wadood; Jyothi George; Shahid Chowdhury; Aliyar Fouladkhah. Synergistic Effects of Nisin, Lysozyme, Lactic Acid, and CitricidalTM for Enhancing Pressure-Based Inactivation of Bacillus amyloliquefaciens, Geobacillus stearothermophilus, and Bacillus atrophaeus Endospores. Microorganisms 2021, 9, 653 .
AMA StyleSadiye Aras, Niamul Kabir, Sabrina Wadood, Jyothi George, Shahid Chowdhury, Aliyar Fouladkhah. Synergistic Effects of Nisin, Lysozyme, Lactic Acid, and CitricidalTM for Enhancing Pressure-Based Inactivation of Bacillus amyloliquefaciens, Geobacillus stearothermophilus, and Bacillus atrophaeus Endospores. Microorganisms. 2021; 9 (3):653.
Chicago/Turabian StyleSadiye Aras; Niamul Kabir; Sabrina Wadood; Jyothi George; Shahid Chowdhury; Aliyar Fouladkhah. 2021. "Synergistic Effects of Nisin, Lysozyme, Lactic Acid, and CitricidalTM for Enhancing Pressure-Based Inactivation of Bacillus amyloliquefaciens, Geobacillus stearothermophilus, and Bacillus atrophaeus Endospores." Microorganisms 9, no. 3: 653.
Current study investigated effects of elevated hydrostatic pressure exposure in the presence of mild heat and natural antimicrobials against Staphylococcus aureus. Hydrostatic pressure of 350 to 550 MPa with nisin (5000 IU/mL), carvacrol, or caprylic acid (0.5% v/v) were applied for the reduction in four-strain mixture of S. aureus in HEPES buffer at 4 and 40 °C for up to 7 min. Results were statistically analyzed by ANOVA and D-values were additionally calculated using best-fitted linear model. Prior to exposure to treatments at 4 °C, counts of the pathogen were 7.95 ± 0.4 log CFU/mL and were reduced (p < 0.05) to 6.44 ± 0.3 log CFU/mL after 7 min of treatment at 450 MPa. D-value associated with this treatment was 5.34 min (R2 = 0.72). At 40 °C, counts were 8.21 ± 0.7 and 5.77 ± 0.3 log CFU/mL before and after the 7-min treatments, respectively. D-value associated with 40 °C treatment was 3.30 min (R2 = 0.62). Application of the antimicrobials provided additional pathogen reduction augmentation for treatments < 5 min. The results of the current study could be incorporated for meeting regulatory requirements such as Food Code, HACCP, and Preventive Control for Human Food of Food Safety Modernization Act for assuring microbiological safety of products against this prevalent pathogen of public health concern.
Jyothi George; Sadiye Aras; Niamul Kabir; Sabrina Wadood; Shahid Chowdhury; Aliyar Cyrus Fouladkhah. Sensitivity of Planktonic Cells of Staphylococcus aureus to Elevated Hydrostatic Pressure as Affected by Mild Heat, Carvacrol, Nisin, and Caprylic Acid. International Journal of Environmental Research and Public Health 2020, 17, 7033 .
AMA StyleJyothi George, Sadiye Aras, Niamul Kabir, Sabrina Wadood, Shahid Chowdhury, Aliyar Cyrus Fouladkhah. Sensitivity of Planktonic Cells of Staphylococcus aureus to Elevated Hydrostatic Pressure as Affected by Mild Heat, Carvacrol, Nisin, and Caprylic Acid. International Journal of Environmental Research and Public Health. 2020; 17 (19):7033.
Chicago/Turabian StyleJyothi George; Sadiye Aras; Niamul Kabir; Sabrina Wadood; Shahid Chowdhury; Aliyar Cyrus Fouladkhah. 2020. "Sensitivity of Planktonic Cells of Staphylococcus aureus to Elevated Hydrostatic Pressure as Affected by Mild Heat, Carvacrol, Nisin, and Caprylic Acid." International Journal of Environmental Research and Public Health 17, no. 19: 7033.
Since the historic outbreak near Broad Street in London, which serves as cornerstone of modern epidemiology, infectious diseases spread in surface and sub-surface water has been a persisting public health challenge. The current study investigated persistence of wild-type and pressure-stressed Listeria monocytogenes, Escherichia coli O157:H7, and non-typhoidal Salmonella enterica serovars in surface water stored aerobically for up to 28 days at 5, 25, and 37 °C. Additionally, biofilm formation of wild-type and pressure-stressed non-typhoidal Salmonella serovars were monitored on surface of stainless steel and rubber coupons for 28 days at 25 and 37 °C. While L. monocytogenes exhibited a lower (p < 0.05) survival rate at 5 °C, relative to the two Gram-negative pathogens, at higher temperatures of 25 and 37 °C, all three pathogens exhibited similar (p ≥ 0.05) trends for survival in surface water. Both wild-type and pressure-stressed Salmonella serovars in the vast majority of tested times, temperatures, and surfaces exhibited comparable (p ≥ 0.05) persistence and biofilm formation capability. Our study thus indicates the occurrence of contamination could lead to prolonged survival of these microorganisms in low-nutrient environments and highlights the need for preventive measures such as those articulated under Produce Safety Rule of the U.S. Food Safety Modernization Act.
Niamul Kabir; Sadiye Aras; Sabrina Wadood; Shahid Chowdhury; Aliyar Cyrus Fouladkhah. Fate and Biofilm Formation of Wild-Type and Pressure-Stressed Pathogens of Public Health Concern in Surface Water and on Abiotic Surfaces. Microorganisms 2020, 8, 408 .
AMA StyleNiamul Kabir, Sadiye Aras, Sabrina Wadood, Shahid Chowdhury, Aliyar Cyrus Fouladkhah. Fate and Biofilm Formation of Wild-Type and Pressure-Stressed Pathogens of Public Health Concern in Surface Water and on Abiotic Surfaces. Microorganisms. 2020; 8 (3):408.
Chicago/Turabian StyleNiamul Kabir; Sadiye Aras; Sabrina Wadood; Shahid Chowdhury; Aliyar Cyrus Fouladkhah. 2020. "Fate and Biofilm Formation of Wild-Type and Pressure-Stressed Pathogens of Public Health Concern in Surface Water and on Abiotic Surfaces." Microorganisms 8, no. 3: 408.
Pectobacterium and Dickeya species, usually referred to as soft rot Enterobacteriaceae, are phytopathogenic genera of bacteria that cause soft rot and blackleg diseases and are responsible for significant yield losses in many crops across the globe. Diagnosis of soft rot disease is difficult through visual disease symptoms. Pathogen detection and identification methods based on cultural and morphological identification are time-consuming and not always reliable. A polymerase chain reaction (PCR)-based detection method with the species-specific primers is fast and reliable for detecting soft rot pathogens. We have developed a specific and sensitive detection system for some species of soft rot Pectobacteriaceae pathogens in the Pectobacterium and Dickeya genera based on the use of species-specific primers to amplify unique genomic segments. The specificities of primers were verified by PCR analysis of genomic DNA from 14 strains of Pectobacterium, 8 strains of Dickeya, and 6 strains of non-soft rot bacteria. This PCR assay provides a quick, simple, powerful, and reliable method for detection of soft rot bacteria.
Niamul Kabir; Ali Taheri; C. Korsi Dumenyo. Development of PCR-Based Detection System for Soft Rot Pectobacteriaceae Pathogens Using Molecular Signatures. Microorganisms 2020, 8, 358 .
AMA StyleNiamul Kabir, Ali Taheri, C. Korsi Dumenyo. Development of PCR-Based Detection System for Soft Rot Pectobacteriaceae Pathogens Using Molecular Signatures. Microorganisms. 2020; 8 (3):358.
Chicago/Turabian StyleNiamul Kabir; Ali Taheri; C. Korsi Dumenyo. 2020. "Development of PCR-Based Detection System for Soft Rot Pectobacteriaceae Pathogens Using Molecular Signatures." Microorganisms 8, no. 3: 358.
Soft rot bacteria of the Pectobacterium and Dickeya genera are Gram-negative phytopathogens that produce and secrete plant cell wall-degrading enzymes (PCWDE), the actions of which lead to rotting and decay of their hosts in the field and in storage. Host chemical signals are among the factors that induce the bacteria into extracellular enzyme production and virulence. A class of compounds (Class I) made up of intermediate products of cell wall (pectin) degradation induce exoenzyme synthesis through KdgR, a global negative regulator of exoenzyme production. While the KdgR− mutant of P. carotovorum is no longer inducible by Class I inducers, we demonstrated that exoenzyme production is induced in this strain in the presence of extracts from hosts including celery, potato, carrot, and tomato, suggesting that host plants contain another class of compounds (Class II inducers) different from the plant cell wall-degradative products that work through KdgR. The Class II inducers are thermostable, water-soluble, diffusible, and dialysable through 1 kDa molecular weight cut off pore size membranes, and could be a target for soft rot disease management strategies.
Paul A. Agyemang; Niamul Kabir; Caleb M. Kersey; C. Korsi Dumenyo. The Bacterial Soft Rot Pathogens, Pectobacterium carotovorum and P. atrosepticum, Respond to Different Classes of Virulence-Inducing Host Chemical Signals. Horticulturae 2020, 6, 13 .
AMA StylePaul A. Agyemang, Niamul Kabir, Caleb M. Kersey, C. Korsi Dumenyo. The Bacterial Soft Rot Pathogens, Pectobacterium carotovorum and P. atrosepticum, Respond to Different Classes of Virulence-Inducing Host Chemical Signals. Horticulturae. 2020; 6 (1):13.
Chicago/Turabian StylePaul A. Agyemang; Niamul Kabir; Caleb M. Kersey; C. Korsi Dumenyo. 2020. "The Bacterial Soft Rot Pathogens, Pectobacterium carotovorum and P. atrosepticum, Respond to Different Classes of Virulence-Inducing Host Chemical Signals." Horticulturae 6, no. 1: 13.
The current study investigated Listeria monocytogenes inactivation using mild heat with elevated hydrostatic pressure and nisin under buffered condition. A four-strain pathogen mixture was exposed to 0 (control) and up to 9 min of (1) 4 °C elevated pressure; (2) 4 °C elevated pressure and nisin; (3) 4 °C nisin; (4) heat at 40 °C; (5) 40 °C elevated pressure; (6) 40 °C elevated pressure and nisin; and (7) 40 °C nisin. Elevated hydrostatic pressure at 400 MPa (Hub880 Explorer, Pressure BioScience Inc., Easton, MA, USA) and nisin concentration of 5000 IU/mL were used in the trials. Analyses of variance were conducted, followed by Dunnett’s- and Tukey-adjusted means separations. Under conditions of these experiments, nisin augmented (p < 0.05) decontamination efficacy of 40 °C heat and elevated hydrostatic pressure treatments, particularly at treatment interval of 3 min. This synergism with nisin faded away (p ≥ 0.05) as the treatment time for thermal, high-pressure, and thermal-assisted pressure processing increased. The results of our study, thus, exhibit that practitioners and stakeholders of pressure-based technologies could benefit from synergism of mild heat and nisin for short-term, high-pressure pasteurization treatments to achieve microbial safety and economic feasibility comparable to traditional heat-treated products.
Sadiye Aras; Niamul Kabir; Shahid Chowdhury; Aliyar Cyrus Fouladkhah. Augmenting the Pressure-Based Pasteurization of Listeria monocytogenes by Synergism with Nisin and Mild Heat. International Journal of Environmental Research and Public Health 2020, 17, 563 .
AMA StyleSadiye Aras, Niamul Kabir, Shahid Chowdhury, Aliyar Cyrus Fouladkhah. Augmenting the Pressure-Based Pasteurization of Listeria monocytogenes by Synergism with Nisin and Mild Heat. International Journal of Environmental Research and Public Health. 2020; 17 (2):563.
Chicago/Turabian StyleSadiye Aras; Niamul Kabir; Shahid Chowdhury; Aliyar Cyrus Fouladkhah. 2020. "Augmenting the Pressure-Based Pasteurization of Listeria monocytogenes by Synergism with Nisin and Mild Heat." International Journal of Environmental Research and Public Health 17, no. 2: 563.
Soilborne diseases are the most economically significant problem faced by Southern region nursery producers. The goal of this research was to improve Rhizoctonia root rot disease management through the use of soil solarization alone and in combination with biofumigant cover crops—arugula ‘Astro’ (Eruca vesicaria ssp. sativa), mustard green ‘Amara’ (Brassica carinata), and turnip ‘Purple top forage’ (B. rapa); good quality compost and mustard meal amendment. The experiments were established as on-farm trials in 2016 and 2017 with prevalent Rhizoctonia solani population in propagation beds. All three biofumigant cover crops, arugula ‘Astro’, mustard green ‘Amara’, and turnip ‘Purple top forage’ in combination with solarization were able to reduce the Rhizoctonia root rot in flowering cherry ‘Kwanzan’ plants in nursery propagation beds. Compost amendment increased the flowering cherry rooted cuttings growth (plant weight, root weight, and plant height) compared to other treatments. Soil solarization in combination with cover crops and organic inputs could be used as part of an integrated approach to manage Rhizoctonia root rot in nursery crop propagation beds.
Fulya Baysal-Gurel; Niamul Kabir; Prabha Liyanapathiranage. Effect of Organic Inputs and Solarization for the Suppression of Rhizoctonia solani in Woody Ornamental Plant Production. Plants 2019, 8, 138 .
AMA StyleFulya Baysal-Gurel, Niamul Kabir, Prabha Liyanapathiranage. Effect of Organic Inputs and Solarization for the Suppression of Rhizoctonia solani in Woody Ornamental Plant Production. Plants. 2019; 8 (5):138.
Chicago/Turabian StyleFulya Baysal-Gurel; Niamul Kabir; Prabha Liyanapathiranage. 2019. "Effect of Organic Inputs and Solarization for the Suppression of Rhizoctonia solani in Woody Ornamental Plant Production." Plants 8, no. 5: 138.
The current study investigated synergism of elevated hydrostatic pressure, habituation, mild heat, and antimicrobials for inactivation of O157 and non-O157 serogroups of Shiga toxin-producing Escherichia coli. Various times at a pressure intensity level of 450 MPa were investigated at 4 and 45 °C with and without carvacrol, and caprylic acid before and after three-day aerobic habituation in blueberry juice. Experiments were conducted in three biologically independent repetitions each consist of two replications and were statistically analyzed as a randomized complete block design study using ANOVA followed by Tukey- and Dunnett’s-adjusted mean separations. Under the condition of this experiment, habituation of the microbial pathogen played an influential (p < 0.05) role on inactivation rate of the pathogen. As an example, O157 and non-O157 serogroups were reduced (p < 0.05) by 1.4 and 1.6 Log CFU/mL after a 450 MPa treatment at 4 °C for seven min, respectively, before habituation. The corresponding log reductions (p < 0.05) after three-day aerobic habituation were: 2.6, and 3.3, respectively at 4 °C. Carvacrol and caprylic acid addition both augmented the pressure-based decontamination efficacy. As an example, Escherichia coli O157 were reduced (p < 0.05) by 2.6 and 4.2 log CFU/mL after a seven-min treatment at 450 MPa without, and with presence of 0.5% carvacrol, respectively, at 4 °C.
Niamul Kabir; Sadiye Aras; Abimbola Allison; Jayashan Adhikari; Shahid Chowdhury; Aliyar Fouladkhah. Interactions of Carvacrol, Caprylic Acid, Habituation, and Mild Heat for Pressure-Based Inactivation of O157 and Non-O157 Serogroups of Shiga Toxin-Producing Escherichia coli in Acidic Environment. Microorganisms 2019, 7, 145 .
AMA StyleNiamul Kabir, Sadiye Aras, Abimbola Allison, Jayashan Adhikari, Shahid Chowdhury, Aliyar Fouladkhah. Interactions of Carvacrol, Caprylic Acid, Habituation, and Mild Heat for Pressure-Based Inactivation of O157 and Non-O157 Serogroups of Shiga Toxin-Producing Escherichia coli in Acidic Environment. Microorganisms. 2019; 7 (5):145.
Chicago/Turabian StyleNiamul Kabir; Sadiye Aras; Abimbola Allison; Jayashan Adhikari; Shahid Chowdhury; Aliyar Fouladkhah. 2019. "Interactions of Carvacrol, Caprylic Acid, Habituation, and Mild Heat for Pressure-Based Inactivation of O157 and Non-O157 Serogroups of Shiga Toxin-Producing Escherichia coli in Acidic Environment." Microorganisms 7, no. 5: 145.
Fulya Baysal-Gurel; Niamul Kabir. Evaluation of fungicides and biocontrol products for the control of Phytophthora root rot of hydrangeas. Archives Of Phytopathology And Plant Protection 2019, 52, 481 -496.
AMA StyleFulya Baysal-Gurel, Niamul Kabir. Evaluation of fungicides and biocontrol products for the control of Phytophthora root rot of hydrangeas. Archives Of Phytopathology And Plant Protection. 2019; 52 (5-6):481-496.
Chicago/Turabian StyleFulya Baysal-Gurel; Niamul Kabir. 2019. "Evaluation of fungicides and biocontrol products for the control of Phytophthora root rot of hydrangeas." Archives Of Phytopathology And Plant Protection 52, no. 5-6: 481-496.
Rhus aromatica, fragrant sumac, is a deciduous shrub native to southeastern Canada, southern and eastern United States and is often used in native plant gardens. Fragrant sumac plants in 1 gal containers with symptoms of leaf spot were received from a commercial nursery in Tennessee in July 2015. The symptoms were dark brown-black, irregularly shaped, greasy leaf spots surrounded by yellow halos; defoliation also occurred. The disease severity (percentage leaf area diseased) was nearly 25% and the disease incidence was nearly 40% of 5,000 plants. Bacterial streaming was observed microscopically from necrotic leaf tissues. Bacteria were isolated from surface- sterilized infected leaf tissue by plating 10- fold serial dilutions onto yeast dextrose carbonate (YDC) and Pseudomonas F agar media. Mucoid, bright yellow colonies consistently developed on YDC. Bacteria were gram negative, oxidase negative, levan positive, esculin hydrolysis positive, catalase positive, and growth at 35°C positive. Two symptomatic leaves and two purified strains (FBGS-1 and FBGS-2) were tested using Xanthomonas immunoblot test (Agdia, Inc., Elkhart, IN). All of the samples were positive. To confirm pathogen identity, total genomic DNA was extracted using the UltraClean Microbial DNA Isolation Kit (MO BIO Laboratories, Inc., Carlsbad, CA) directly from a 2-day old culture. The 16S rRNA gene was amplified by PCR using the universal bacterial primers 8F and 1492R (Galkiewicz and Kellogg, 2008) and sequenced. The sequence (GenBank Accession No. KU709886) was 99% similar to those of Xanthomonas axonopodis strains from several hosts in multiple countries in the NCBI database. Pathogenicity tests were performed using one isolated bacterial strain (FBGS-1) on containerized sumac plants. Three plants were sprayed with a bacterial suspension (108 CFU/ml), covered with clear plastic for 24 h, and directly placed into a greenhouse at 25 to 30°C. Control plants were sprayed with sterilized water and kept in the same condition. Inoculated plants showed leaf spot symptoms after 2 weeks. The bacterium was re-isolated from leaf spots as described above. All control plants remained symptom- free and the bacterium was not isolated from leaf tissue. To the best of our knowledge, this is the first report of bacterial leaf spot on sumac caused by X. axonopodis. Development of effective bacterial disease management practices is necessary for nursery production of woody ornamentals. References: (1) J. P. Galkiewicz and C. A. Kellogg. Appl. Environ. Microbiol. 74:7828, 2008.
F. Baysal-Gurel; T. Simmons; M. N. Kabir; P. Liyanapathiranage. First Report of Bacterial Leaf Spot Caused by Xanthomonas axonopodis Infecting Fragrant Sumac in Tennessee. Plant Disease 2016, 100, 1946 .
AMA StyleF. Baysal-Gurel, T. Simmons, M. N. Kabir, P. Liyanapathiranage. First Report of Bacterial Leaf Spot Caused by Xanthomonas axonopodis Infecting Fragrant Sumac in Tennessee. Plant Disease. 2016; 100 (9):1946.
Chicago/Turabian StyleF. Baysal-Gurel; T. Simmons; M. N. Kabir; P. Liyanapathiranage. 2016. "First Report of Bacterial Leaf Spot Caused by Xanthomonas axonopodis Infecting Fragrant Sumac in Tennessee." Plant Disease 100, no. 9: 1946.