Selected Foodborne Pathogens Research Articles

Impact of Irrigation Source on the Dissemination and Persistence of Coliforms and Foodborne Pathogens in Fresh Tomato High Tunnel-dripline System from Small Specialty Crop Farms

This study investigated the impact of irrigation sources (pond, stream, and well) in high tunnel-dripline systems on the dissemination and persistence of foodborne pathogens (Escherichia coli O157, Listeria monocytogenes, Campylobacter spp., Salmonella spp., and the ‘big six’ Shiga toxin-producing E. coli [STEC]) in small specialty crop farms (SSCFs). Ten SSCF-growing fresh tomatoes using high tunnel-dripline systems were sampled between January and November 2022. Selective enrichment combined with PCR was used to detect the selected foodborne pathogens in the irrigation water (n = 240), soil (n = 240), and tomato fruits (n = 120). Overall, surface-originated water sources (streams and ponds) having potential contact with farm animals or wildlife harbored higher pathogen burden (cumulative prevalence of all the pathogens) compared to subsurface water source (well and underground spring water). STEC O26, O45, and O103 were detected at high frequency (up to 88% per SSCF per time point) in the water source and associated dripline irrigation system of 4/6 SSCFs using stream and pond water. Other foodborne pathogens (especially, L. monocytogenes) were detected in 6/10 SSCFs, but at low frequency (<25% per SSCF per time point). The prevalence of foodborne pathogens in the 10 SSCFs over time was positively correlated with the length of high tunnel and planting date (r2 = 0.93 and 0.79, respectively; P < 0.006). Our study highlighted that dripline irrigation systems may allow the long-distance transport of foodborne pathogens from the contaminated water source to the field. Risk assessment and mitigation measures should be implemented to assure the quality of the water source used for irrigation in SSCF.

Comparative assessment of Rhazya stricta and Azadirachta indica methanolic leaf extracts for their antimicrobial efficacy against the selected foodborne pathogens

Comparative assessment of Rhazya stricta and Azadirachta indica methanolic leaf extracts for their antimicrobial efficacy against the selected foodborne pathogens

Therapeutic effects of orally administration of viable and inactivated probiotic strains against murine urinary tract infection.

Urinary tract infections (UTIs) are highly prevalent bacterial infections that pose significant health risks. Specific probiotic strains have been recommended for UTI control and management of antibiotic resistance. Otherwise, para-probiotics, defined as inactivated probiotic cells, offer potential advantages by minimizing risks associated with live microorganisms. However, the effectiveness of heat-killed probiotic strains against UTIs remains uncertain. Additionally, lactoferrin (LF), an iron-binding glycoprotein, exhibits immunomodulatory, antimicrobial, and anti-inflammatory properties. Recently, we had developed recombinant LF-expression probiotics, which can display considerate antibacterial activities against select food-borne pathogens in vitro. Thus, the present study aimed to evaluate the antibacterial activities of heat-killed natural and recombinant LF-expressing probiotics against UTIs in vitro and in vivo. Firstly, using in vitro assays, we assessed the antibacterial activity of heat-killed natural and recombinant LF-expressing probiotics against uropathogenic Escherichia coli and Klebsiella pneumoniae. Among the tested probiotics, 10 heat-killed LF-expressing strains displayed superior antibacterial efficacy compared to 12 natural probiotics. Based on their potent in vitro activity, selected probiotics were formulated into three probiotic mixtures: viable probiotic mixture (LAB), heat-killed probiotic mixture (HK-LAB), and heat-killed LF-expressing probiotic mixture (HK-LAB/LF). To further evaluate the therapeutic potential of these probiotic mixtures in vivo, we established a murine model of UTIs by intraurethral administration of E. coli to 40 female C57BL/6JNarl mice on day 0. Subsequently, mice received oral gavage of placebo, LAB, HK-LAB, or HK-LAB/LF for 21 consecutive days (n = 8 per group). An additional control group (n = 8) received ampicillin treatment for 7 days. To assess protective effects against re-infection or UTI relapse, all mice were challenged with E. coli on day 22 and E. coli plus K. pneumoniae on day 25. Results from the murine UTI model demonstrated that placebo administration did not reduce bacteriuria throughout the experiment. Conversely, supplementation with ampicillin, HK-LAB/LF, HK-LAB, or LAB significantly (p < 0.05) reduced daily bacteriuria by 103 to 104-fold on days 1, 3, 5, and 14, respectively. Furthermore, all four therapeutic treatments improved the bacteriological cure rate (BCR) with varying levels of efficacy. For the 7-day treatment course, the BCR was 25% (placebo), 62.5% (ampicillin), 37.5% (LAB), 37.5% (HK-LAB), and 62.5% (HK-LAB/LF). For the 21-day treatment course, the BCR was 25% (placebo), 75% (ampicillin), 37.5% (LAB), 37.5% (HK-LAB), and 75% (HK-LAB/LF). Notably, HK-LAB and HK-LAB/LF demonstrated superior therapeutic efficacy compared to viable LAB in treating UTIs. Overall, regarding BCR, the three probiotic mixtures can provide benefits against UTI in mice, but ampicillin therapy remains the most efficient among the four treatments. Furthermore, there was no significant difference between pre- and post-challenge courses for the two instances of re-challenging uropathogens in all mice groups, as bacteriuria levels remained below 103 CFU/mL, implying that adaptive responses of mice may help reduce the risk of recurrent UTIs. In conclusion, our results provide new evidence that oral administration of heat-killed probiotic mixtures can confer significant therapeutic efficacy against UTIs in a murine model.

Factors Associated with Foodborne Pathogens among Food Handlers: A Case Study of Thika, Kiambu County, Kenya

Increasing risks of infections with foodborne pathogens may occur as a result of poor food handling practices. The present cross-sectional study employed a mixed-methods approach to determine the factors associated with foodborne pathogens among food handlers working in the food establishments in Thika, Kiambu County, Kenya. Random sampling was used to enroll respondents in the survey. A single stool specimen was collected from each study participant. Laboratory analysis of the specimen was done to test the selected foodborne pathogens. Overall, 44 out of the 285 food handlers who took part in the study had at least one food-transmitted pathogen, putting the prevalence of foodborne infections among the food handlers at 15.4% (95% confidence interval (CI) 11.7%–20.1%). The findings from multivariate logistic regression indicated the following protective factors for foodborne pathogens among the studied food handlers: being female (adjusted odds ratio (AOR) 0.098 (95% CI 0.0304–0.315, p &lt; 0.001 )); having a valid medical examination certificate (AOR 0.141 (95% CI 0.141–1. 0.439, p = 0.001 )); not boiling or treating water before serving the water to customers was a risk factor for having infections with foodborne pathogens (AOR 3.043 (95% CI 1.2225–7.577, p = 0.017 )). The presence of foodborne pathogens among the food handlers in the study area potentially highlights the need to address the spread and transmission of foodborne infections in the study area. There is a need to institute appropriate control measures, including regular screening of food handlers for foodborne illnesses in addition to training them on safe food handling practices, hand hygiene practices, and regular monitoring of the food handling practices.

Antimicrobial Activity of Sugarcane Vinegar with Eatables Against Selected Food Borne Pathogens

Antimicrobial Activity of Sugarcane Vinegar with Eatables Against Selected Food Borne Pathogens

The Effectiveness of Benzalkonium Chloride as an Active Compound on Selected Foodborne Pathogens Biofilm

Benzalkonium chloride (BAC) is a chlorine-based chemical compound with proven antimicrobial properties against bacteria, viruses, and fungi, depending on the length of the alkyl chain. It can be used as a biocide, as a cationic surfactant, and as a phase transfer agent. The aim of this study was to investigate the effectiveness of commercial cleaning agents for sanitary areas Bis duo Active (BDA) with BAC as an active compound in working concentrations of 5% and 20% on the destruction of bacterial biofilm formed on ceramic tiles. A biofilm of Staphylococcus aureus, Salmonella enterica serotype Typhimurium, and Listeria monocytogenes were grown on ceramic tiles with dimensions of 2.5 × 2.5 cm over 24 h. These plates were then treated with working concentrations of BAC for 10 min. After washing, ATP bioluminescence was measured with a luminometer, CFU/cm2 was determined and the total biomass reduction was measured after crystal-violet staining. Both working concentrations of benzalkonium chloride proved to be very effective in destroying the created bacterial biofilm on ceramic tiles. Both treatments caused a reduction in total bacteria number of up to 3.12 log10CFU/cm2, followed by a reduction in total biomass up to circa (ca.) 64%. Inhibition rates varied from ca. 28% to ca. 99%, depending on the method and concentration used. Mechanical cleaning prior or after treatment with BAC is essential to improve biofilm destruction. All methods used in this study are effective for the determination of the anti-biofilm activity of BAC. Further analyses are needed.

ASSESSING THE MICROBIOLOGICAL QUALITY AND SAFETY OF BIOFILM FORMING MICROORGANISMS FROM SELECTED FOODS IN ULI CAMPUS

Biofilms are complex microbial ecosystems formed by one or more species immersed in an extracellular matrix of different compositions depending on the type of food manufacturing environment and the colonizing species. Food-borne diseases associated with bacterial biofilms may arise via intoxications or infections. The main aim of this work is to isolate and identify microorganisms present in some selected food borne pathogens that forms biofilms, investigate for bacterial and fungal contamination and conduct antibiotic sensitivity testing on the bacterial isolates. Biofilm forming microorganisms was isolated from some selected food samples and contact surface. The samples were cultured and sub-cultured to get pure isolates. Bacteria and fungi isolates were identified and characterized using various biochemical tests. Antibiotic susceptibility test was performed on the various bacterial isolates. Suspected microorganisms recovered from the tests were Staphylococcus spp., Salmonella enterica, Escherichia coli, Pseudomonas spp., Candida albicans, Aspergillus spp., and Penicillum spp. The antibiotic susceptibility profile of the bacterial isolates from food samples revealed that E. coli showed susceptibility to Tarivid (OFX) 10 mcg, Reflacine (PEF) 10 mcg, Ciproflox (CPX) 10 mcg, Gentamicine (CN) 10 mcg and Streptomycine (S) 30mcg. S. enterica showed susceptibility to Ciproflox (CPX), Gentamicine (CN) and Streptomicine (s). S. aureus showed susceptibility to Ciproflox (CPX), Streptomicine (s) and Gentamicine (CN) and P. aeruginosa was resistance to the antibiotics used. Many foodborne diseases have been found to be associated with biofilms. The source of contamination from the pathogens investigated could be from contamination of utensils by pathogens, contamination from butcher’s table and knives and from food processing industry. The investigation concluded that bacterial and fungal species associated with food contamination is found to be associated with biofilms.

Antimicrobial activity of bacteriocin produced by a new Latilactobacillus curvatus sp.LAB-3H isolated from traditional yogurt.

In recent years, the use of bacteriocin-producing Lactobacillus species has received much attention in different areas, including using as probiotics, food preservation, and as broad antimicrobial spectrum activity. In this study, a bacteriocin-producingLactobacillusstrain was isolated from traditional yogurt. The isolate was identified by morphological, biochemical, 16S rRNA analyses, and designated asLatilactobacillus curvatusLAB-3H. The primary antimicrobial activity of the isolate was evaluated onMicrococcus luteusPTCC 1408 by the agar gel diffusion method. The growth ofL. curvatusLAB-3H in MRS broth at 37°C and its antimicrobial activity againstLactobacillus caseiATCC 39,392 was evaluated. In batch culture analysis, bacteriocin production starts at the early exponential growth phase and continues to the middle of the stationary phase about (660 AU/ml) at 28h and pH 3.8. Bacteriocin produced byL. curvatusLAB-3H showed antibacterial activity against some selected foodborne pathogens, includingListeria monocytogenesPTCC1294,Bacillus cereusPTCC1857,Staphylococcus aureusPTCC1917, andEscherichia coliPTCC1276. For purification of bacteriocin, ammonium sulfate precipitation and cation exchange chromatography methods were used. The maximum antimicrobial activity observed was about 3985.15 AU/mg of protein, which was a 249.22-fold increase, and 5.21% yield compared with that in the cell-free supernatant. The molecular weight of bacteriocin was approximately 55kDa by SDS-PAGE. The obtained results in this study demonstrate that bacteriocin fromL. curvatusLAB-3H is a potential candidate for controlling microbial contaminations and can be used in different sectors, such as food industries.

Effect of Turmeric (Curcuma longa) Spice on Nutrititional, Microbial Content of Moin-Moin and Efficacy of Spice Against Selected Foodborne Pathogens

Turmeric (Curcuma longa) impacts flavor, organoleptic quality of foods and contributes to the preservation of foods. Moin-moin is an indigenous food made from beans (Vigna unguiculata) and highly perishable. This study investigated the effect of turmeric spice on quality of moin-moin, and the efficacy of turmeric on selected foodborne pathogens. Three samples were prepared with (0; 2.5 and 5g) of turmeric. Nutritional, microbial, sensory and efficacy of spice against microorganisms were performed. Moisture content ranged from (1.35 to 1.48%), protein (38.9 to 44.9%), ash (6.2 to 7.4%), fat (11 to 11.8%) and fibre (6.9 to 7.7%). TVC of samples for day zero was (3.1 to 6.8 x 105CFU/g); Enterobacteriaceae (1.1 to 2.1x105CFU/g); Staphylococcal (2.7 to 4.6 x105CFU/g); and Coliform (6.4 to 8.3x105CFU/g). After 48 h, sample with 5g of spice and refrigeration had reduced microbial load. Moin-moin with 2.5g of turmeric was generally accepted and considered the best sample. Turmeric spice was observed to be more effective against Salmonella spp. Conclusively, addition of turmeric to moin-moin was able to reduce the microbial load and improve the shelf-life of the product.

GC-HRMS screening of bioactive compounds responsible for antimicrobial and antioxidant activities of blood fruit (Haematocarpus validus Bakh. F. Ex Forman) of North-East India

The aims of this study are to evaluate phytochemical composition, antimicrobial and antioxidant activities of different solvent-assisted blood fruit pulp extracts. The extracts of blood fruit were prepared with various solvents namely, water, ethyl acetate, methanol and acetone. These extracts were divided into two groups, first group of extract were thermosonicated (treated) and the second group were not exposed to thermosonication (untreated). The sample extracts were then evaluated for their antimicrobial properties against various microorganisms. The results revealed that the antimicrobial activity of thermosonicated ethyl acetate extracts at 12mg/mL concentration exhibited the highest inhibition zone of 19.4mm against Staphylococcus aureus. The phenolic content of ethyl acetate extract was found to be the highest as compared to that of other solvent extracts and the values were 1508.08 and 1478.34mg GAE/100g for treated and untreated samples, respectively. The treated ethyl acetate extract antioxidative activity by DPPH, ORAC, ABTS, and FRAP assay were 1627.68, 2119.82, 938.11, and 2360.18µmolTE/g, respectively. The minimum bactericidal concentration (MBC -1.5mg/mL) against the selected foodborne pathogens was obtained with thermosonicated ethyl acetate blood fruit extract. In the present study, it was observed that the thermosonicated ethyl acetate extract exhibits maximum antioxidant and antimicrobial activities than any other examined solvent extracts. The major bioactive volatile compounds found in treated ethyl acetate extracts were 2-bromotetradecane, tetracosane, heptadecane, eicosane and palmitic acid. These bioactive compounds can be utilizable for the development of functional, nutraceutical and pharmacological products.

Antimicrobial Activity of Six International Artisanal Kefirs Against Bacillus cereus, Listeria monocytogenes, Salmonella enterica serovar Enteritidis, and Staphylococcus aureus.

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.

Survival Pattern and Toxin Production of Pathogens in Spiced and Non Spiced Fried Rice

Aims: There is no data regarding the survival rate of pathogens in party foods held at different temperature and time interval in Nigeria. Hence, the need to study the survival rate of selected food borne pathogens in Fried rice (spiced and non – spiced) served at parties, monitor toxin production and the rate at which it is produced with respect to time and holding temperature as well as determine the effect of spices on the survival of food pathogens.&#x0D; Place and Duration of Study: Lagelu and Ibadan North Local Government Authority Area of Ibadan, Oyo State, Nigeria, between May 2017 and September 2017.&#x0D; Methodology: We obtained 10 fried rice samples (5 spiced and 5 non- spiced) from different parties inside sterile food warmers and transferred to the Food Microbiology Laboratory. Pathogens inoculated were obtained from the culture collection unit of the Food Microbiology laboratory and they were Bacillus cereus, Staphylococcus aureus, Salmonella typhi and Escherichia coli. Inoculum size of the pathogens was determined prior to inoculation. Initial temperature of the fried rice sample was taken and after inoculation, samples were taken at an interval of 2 hours to determine the survival rate of the pathogens. Brine Shrimp Lethality (BSL) assay was used to determine the level of toxin produced.&#x0D; Results: The microbial load of all pathogens inoculated increased from its initial size as the holding temperature reduces and holding time increases. For E. coli, there was an increase from 5.3 log10CFU/g to 9.3 log10CFU/g and 8.3 log10CFU/g in non–spiced fried rice and spiced fried rice, respectively, initial load for S. typhi also increase from 4.1 log10CFU/g to 9.1 and 8.4, for B. cereus and S. aureus there was an increase form 6.3 log10CFU/g to 9.0 and 8.4 for non-spiced and spiced rice respectively. Toxicity test shows that the lethal dose was high at 8 hours (LC50:1.5) which connotes that the toxicity was high at this holding time.&#x0D; Conclusion: Holding cooked foods at ambient temperature for 6 h or longer without appropriate reheating constitute a major critical control point for party food. Keeping foods at the right temperatures is an essential food safety practice. Adequate knowledge and application of this by caterers will reduce the rate of food borne illness in the country.

Salmonella and Shiga Toxin–Producing Escherichia coli in Products Sampled in the Food Safety and Inspection Service Raw Pork Baseline Study

The Food Safety and Inspection Service (FSIS) conducts microbiological baseline studies to determine national prevalence of select foodborne pathogens in federally inspected meat and poultry products and to obtain data for risk assessments. The FSIS conducted a baseline study from 1 June 2017 through 31 May 2018 to characterize and determine the prevalence of Salmonella and assess the occurrence of Shiga toxin-producing Escherichia coli (STEC) in a variety of raw pork products. In total, 4,014 samples from slaughter and processing establishments were analyzed for Salmonella; a subset of these samples (1,395) from slaughter establishments were also analyzed for STEC. Analyses determined that the national prevalence of Salmonella in raw pork products was highest in comminuted products (28.9%), followed by intact cuts (5.3%) and nonintact cuts (3.9%). Less than 1% of samples analyzed were positive for the top seven STEC. Our findings indicate there is a need for additional pathogen reduction strategies for raw pork products.

Selenite Cystine Agar for Enumeration of Inoculated Salmonella Serovars Recovered from Stressful Conditions During Antimicrobial Validation Studies.

Process validation studies often require the inoculation of select foodborne pathogens into targeted foods to determine the lethality of the process or antimicrobial ingredients, and quantitative recovery of surviving inoculum bacteria helps to make those assessments. Such processes introduce various stressors on the inoculated challenge microorganisms whereby traditional selective media are too harsh to enumerate the remaining viable and injured population quantitatively. Innate antibiotic resistance of challenge organisms has often been used to establish simple selective media (i.e., Tryptic Soy Agar/TSA + antibiotics) for recovering inoculated strains, but sometimes antibiotic resistant background microorganisms are higher than desired. Salmonella Thompson 120, Salmonella Heidelberg F5038BG1, Salmonella Hadar MF60404, Salmonella Enteritidis H3527, and Salmonella Typhimurium H3380 were characterized for antibiotic resistance and acid adaptation in Tryptic Soy Broth containing 0%, 0.25%, or 1.0% glucose. Sodium pyruvate was evaluated for recovery after stress but no enhancing effect was observed, possibly because the strains were acid-adapted. Selenite Cystine Broth, traditionally used as a selective enrichment broth, was used as the basis for Selenite Cystine Agar (SCA) in combination with three antibiotics to which our Salmonella are resistant. Serovars of Salmonella, both individually and in mixtures, were enumerated on TSA, SCA, Xylose Lysine Desoxycholate (XLD), and Hektoen Enteric (HE) selective agars (all containing the same antibiotics) after conditions of nutrient starvation, desiccation, acid stress, and thermal stress. The data show that quantitative enumeration of our Salmonella serovars on SCA was not significantly different (p > 0.05) than those achieved on TSA for all tested stress categories. Levels of Salmonella enumerated on XLD and/or HE were significantly different (p < 0.05) than on TSA and SCA and often more than 1–2-log lower, consistent with the inhibition of injured cells. These data confirm that SCA (+ antibiotics) is a suitable selective medium for enumeration of these acid-adapted Salmonella serovars as challenge organisms recovered from various conditions of stress.

The Antimicrobial Effect of Radiant Catalytic Ionization on the Bacterial Attachment and Biofilm Formation by Selected Foodborne Pathogens under Refrigeration Conditions

The decontamination of food contact surfaces is a major problem for the food industry. The radiant catalytic ionization (RCI) method, based on the ionization process, may be an alternative for conventional decontamination procedures. The advantage of this technique is the possibility of its application to household refrigerating appliances and industrial cold rooms. This study aimed to assess the effect of RCI on the reduction of Campylobacter jejuni, Listeria monocytogenes, and Salmonella Enteritidis from the biofilms formed on a glass surface under refrigeration conditions. Bacterial biofilms were exposed to RCI for 24 h and after 12 (variant I) and 72 h (variant II) of the glass surface contamination. In the last variant (III), the contaminated meat was placed on the glass surface in the refrigerator and subjected to RCI treatment for 72 h. The significantly highest values of absolute reduction efficiency coefficient E were found for the bacterial attachment stage of biofilm formation (variant I). The research proves the efficiency of the RCI method in the reduction of bacteria number from a glass surface.

Suppressive effects of Streptococcus thermophilus KLDS 3.1003 on some foodborne pathogens revealed through in vitro, in vivo and genomic insights.

Foodborne diseases (FBDs) remain a persistent global challenge and recent research efforts suggest that lactic acid bacteria (LAB) strains can contribute towards their prevention and treatment. This study investigates the genetic properties of Streptococcus thermophilus KLDS 3.1003 as a potential probiotic and health-promoting LAB strain as well as its in vitro and in vivo activities against two foodborne pathogens. In vitro, its antimicrobial activities and tolerance levels in simulated bile salts and acids were determined. The cytotoxic effects of the LAB strain in RAW264.7 cells were also evaluated. For in vivo evaluation, 24 BALB/c mice were orally administered control and trial diets for 14 days. Genomic analyses of this strain's bacteriocin configuration, stress response system and multidrug resistance genes were annotated to validate in vitro and in vivo results. In vitro antimicrobial results show that the cells and CFS of S. thermophilus KLDS 3.1003 could inhibit both pathogens with the former being more effective (P < 0.05). In addition, its cell-free supernatant (CFS) could inhibit the growth of both pathogens, with catalase treatment having the highest effect against it. More so, after 3 h of incubation, survivability levels of S. thermophilus KLDS 3.1003 were significantly high (P < 0.05). LPS-induced RAW264.7 cell activities were also significantly reduced by 108-109 CFU mL-1 of S. thermophilus KLDS. In vivo, significant weight losses were inhibited in the TSTEC group compared to the TSTSA group (P < 0.05). Moreover, pathogen-disrupted blood biochemical parameters like HDL, LDL, TP, TG, AST, ALT and some minerals were restored in the respective prevention groups (TSTEC and TSTSA). Genomic analyses showed that S. thermophilus KLDS 3.1003 has bacteriocin-coding peptides, which accounts for its antimicrobial abilities in vitro and in vivo. S. thermophilus KLDS 3.1003 is also endowed with intact genes for acid tolerance, salt-resistance, cold and heat shock responses and antioxidant activities, which are required to promote activities against the selected foodborne pathogens. This study showed that S. thermophilus KLDS 3.1003 has the genomic capacity to inhibit foodborne pathogens' growth in vitro and in vivo, thus qualifying it as a potential probiotic, antimicrobial and bio-therapeutic candidate.

Chemical Composition and Antibacterial Activity of the Essential Oil from Qiancao (&lt;i&gt;Rubia cordifolia &lt;/i&gt;Linn.) Roots against Selected Foodborne Pathogens

Chemical composition of the essential oil from Qiancao roots was analyzed by gas chromatography-mass spectrometry (GC-MS), and 43 components were identified in the paper. Mollugin (30.58%) was found to be the major component, followed by 3-methyl-2-cyclopenten-1-one (10.55%), 4-tert-butyl-2-phenyl-phenol (8.64%) and eugenol (6.30%). The antibacterial activity of essential oil against selected food-borne pathogens was evaluated. The results showed that the sensitivity to essential oil were different for different tested bacteria and the essential oil had a strong antibacterial activity against B. cereus with the lowest minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC) values of 0.0625 and 0.125 mg/mL, respectively. In addition, microbial growth curve assay also showed that the essential oil had a significant effect on the growth rate of surviving B. cereus. The data of this study suggests that the essential oil from Qiancao roots has great potential for application as a natural antimicrobial agent to preserve food.

Screening of Antimicrobial and Synergistic Activity of Withania somnifera , Aloe vera Plant Extracts and Certain Lactic Acid Bacterial Strains against Food Borne Pathogens

The methanolic extract of plants Withania somnifera , Aloe vera and certain lactic acid bacterial (LAB) strains were evaluated for their antibacterial and synergistic effect against food borne pathogens. Antagonistic/synergistic activity of plant extracts and LAB were tested alone and combinely against selected food borne pathogens by using well diffusion method. The results exhibited that the extracts of Withania somnifera , Aloe vera and the lactic acid bacterial strainswere showed excellentantimicrobial activity when they are tested alone against the test organisms.But the results obtained from the combined testing of methanolic extracts of plants and Lactic acid bacterial strains significantly lesser antibacterial activityagainst all the tested organisms except with Pediococciacidolactici 252 which showed synergistic activity with methonalic extract of Withania somnifera against E.coli . The present study indicated that the methanolic extracts of Withania somnifera , Aloe vera and LAB showed good antibacterial activity when they are used individually then the combined and these can be used as a natural drug for the treatment of several infectious diseases.

Evaluation of peanut skin and grape seed extracts to inhibit growth of foodborne pathogens

Peanut skin extract (PSE) and grape seed extract (GSE) are derived from waste products in the wine and peanut industries, respectively. Both have high concentrations of polyphenols, known to possess antioxidant and antimicrobial properties. PSE primarily contains “A‐type” procyanidins, while GSE primarily contains “B‐type” procyanidins. These differ structurally, but are both isomers of epicatechin dimers. The objective of this study was to evaluate the antimicrobial effects of PSE containing A‐type procyanidins and GSE containing B‐type procyanidins against select foodborne pathogens (Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium). The minimum inhibitory concentration (MIC) of the two extracts on L. monocytogenes, E. coli O157:H7, and S. Typhimurium was determined using the pour plate method. GSE had a significantly lower MIC (p ≤ .05) than PSE for L. monocytogenes (GSE = 60.6 ppm, PSE > 68.2 ppm) and S. Typhimurium (GSE = 45.7 ppm, PSE = 60.6 ppm), but no difference in inhibition of E. coli O157:H7. Since GSE contributed to greater inhibition, GSE extract was fractionated into monomer‐rich (consisting primarily of catechins, epicatechins, and epicatechin gallates) and oligomer‐rich (consisting of dimers, trimers, tetramers, up to decamers) components. Growth curves of all three pathogens in the presence of full extract, monomer and oligomer fractions were compared separately. None of the extracts inhibited S. Typhimurium growth. Generally, the extract containing greater oligomer components inhibited growth of L. monocytogenes and E. coli O157:H7 when compared to the control. Results indicate that an extract with type B procyanidins higher in oligomers may have greater antimicrobial properties.

Chemical Composition and Antibacterial Action of Robinia pseudoacacia L. Flower Essential Oil on Membrane Permeability of Foodborne Pathogens

This research investigates the chemical composition of flower essential oil of Robinia pseudoacacia (FEORP) by GC-MS analysis and reports its antimicrobial efficacy against selected foodborne pathogens. The GC-MS analysis of FEORP confirmed the presence of 27 compounds which represented 94.46 % of total oil. Further, FEORP (1000 μg/disc) exhibited significant antimicrobial effects against some of the selected foodborne pathogens such as Staphylococcus aureus KCTC 1621, Bacillus subtilis KCTC 3569, Listeria monocytogenes KCTC 3569, Escherichia coli O157:H7 and Salmonella enterica ATCC 4731 with diameters of the zones of inhibition (15.2 ± 0.3-17.3 ± 2.0 mm) as well as the MIC and MBC (250-1,000 μg/mL). Additionally, FEORP at MIC reduced cell viabilities of two selected foodborne pathogens, B. subtilis KCTC 3569 and E. coli O157:H7. Furthermore, FEORP established its inhibitory effect on the membrane integrity of both selected bacterial pathogens as indicated by the increased release of extracellular ATP and relative electrical conductivities as well as the loss of 260-nm absorbing materials, and leakage of potassium ions, suggesting that FEORP could be an effective and natural agent for controlling the growth of hazardous foodborne pathogens.