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Journal of Food Protection Jun 2024The current study assessed (i) the microbiological safety level profiles (MSLPs) of milkmen's hands and milking containers and (ii) the influence of hygiene and handling...
The current study assessed (i) the microbiological safety level profiles (MSLPs) of milkmen's hands and milking containers and (ii) the influence of hygiene and handling practices on MSLPs of raw and cultured milk, from six informal dairy farms in Zimbabwe. Interviews and direct observations were carried out during the assessment of hygiene and handling practices at six farms designated A to F. Microbiological criteria of the following six microbiological parameters: Total Bacterial Counts (TBCs), Coliform Counts (CCs), Total Escherichia coli Counts (TECs), Salmonella spp., Listeria monocytogenes and Klebsiella pneumonia, were used to determine contamination level (CL) at four different critical sampling locations (CSLs). The CSLs were raw milk (CSL1), cultured milk (CSL2), milkmen's hands (CSL3), and milking containers (CSL4). The microbiological criteria of the six microbiological parameters were used to score CLs as: intolerable (0), poor to average (1), average (2), and good (3). MSLPs at each CSL for the six farms were computed based on the CL scores to a maximum score of 18. A total of 192 samples were collected and analyzed. Salmonella spp. and L. monocytogenes were not detected at all the CSLs. All the farms failed to achieve a maximum MSLP score of 18 at all the CSLs. The relationship between MSLPs and hygiene and handling practices was tested using point-biserial correlation coefficients. The correlation study revealed that handling and hygiene practices (such as the duration between milking and storage, the type of milking container utilized at farms, the frequency of cleaning the milking parlor, the water source for hand and equipment washing, and the use of hand sanitizers) generally influenced the MSLPs on the farms. Both training and improvement in infrastructure are needed to improve the quality of milk and its products produced and sold in the informal value chain in Zimbabwe.
PubMed: 38871224
DOI: 10.1016/j.jfp.2024.100313 -
Journal of Food Protection Jun 2024In recent years, there have been numerous recalls of frozen vegetable products due to Listeria monocytogenes contamination, which causes listeriosis. In pregnant women,...
In recent years, there have been numerous recalls of frozen vegetable products due to Listeria monocytogenes contamination, which causes listeriosis. In pregnant women, listeriosis can cause miscarriage, stillbirth, and other serious complications. Manufacturing guidelines are created with the intention that frozen vegetables will be cooked prior to consumption. However, consumers may prepare and eat frozen vegetables without prior cooking. Therefore, it is necessary to assess behaviors that could be risky for L. monocytogenes exposure. A 10-question online survey was distributed to women between the ages of 18-54 to investigate frozen vegetable consumption behaviors. The prevalence of uncooked frozen vegetable consumption, reading preparation instructions, and listeriosis knowledge was assessed. Data were analyzed using logistic and ordered logit regression. Of 1,001 complete responses, 531 (53%) indicated that they consumed frozen vegetables in the past week, and of those 35.6% (n = 189) indicated that they consumed frozen vegetables without prior heating. Women who had not heard of listeriosis and had not read preparation instructions had significantly higher odds of uncooked frozen vegetable consumption (Odds Ratio (OR): 2.30, 95% Confidence Interval (CI): 1.48, 3.55; OR: 1.85, 95% CI: 1.13, 3.01, respectively). These results will guide future research on safe food handling practices for frozen vegetable products. The findings support the need for updating public health guidelines to include frozen vegetables as foods that are risky for listeriosis in pregnancy. Additionally, these findings have implications for future research to inform food policy governing labeling regulation on frozen vegetable products to reflect current consumer behavior.
PubMed: 38871223
DOI: 10.1016/j.jfp.2024.100315 -
Meat Science Jun 2024Present study is focused on exploring in vitro antimicrobial activity of ginseng extract (GE) against Staphylococcus aureus, Salmonella Typhimurium and Listeria...
In vitro antimicrobial activity of ginseng extract against Staphylococcus aureus, Salmonella Typhimurium and Listeria monocytogenes and its inhibitory effects on these pathogens in cooked ground beef.
Present study is focused on exploring in vitro antimicrobial activity of ginseng extract (GE) against Staphylococcus aureus, Salmonella Typhimurium and Listeria monocytogenes and their biofilm forming ability, then determining its antimicrobial efficiency during the storage (4 and 10 °C) of cooked ground beef contaminated with these pathogens. Results revealed that the minimum inhibitory concentration (MIC) for S. aureus, S. typhimurium and L. monocytogenes were 90, 70 and 40 mg/mL, respectively. GE was also able to inhibit biofilm production by S. aureus and L. monocytogenes, whereas S. typhimurium did not produce biofilm with or without GE application. On the other hand, the results of GE aplication in ground beef indicated that GE incorporation at 0.5% or more reduced S. aureus and S. Typhmurium counts in cooked ground beef at the end of 30 d storage at 4 °C (P < 0.05). Using 1% or more GE totally inhibited S. Typhmurium after 15 d storage at 4 °C (P < 0.05). However, GE application did not affect S. aureus or S. Typhmurium counts in cooked ground beef stored at 10 °C. Furthermore, incorporation of 0.5% or more GE generally inhibited L. monocytogenes growth in cooked ground beef at the end of storage at both 4 and 10 °C (P < 0.05). In general, pH was lower in samples with GE than those without GE regardless of differences in the type of tested pathogen, storage time and temperatures (P < 0.05). Although similar a was generally obtained on processing day, lower a was observed in GE containing groups at the end of storage for both storage temperatures (P < 0.05). Oxidation reduction potential (ORP) in all groups generally increased during storage at both storage temperatures (P < 0.05). In conclusion, our results demonstrated that GE has an important role in controlling growth of tested pathogens and may be used as a natural agent by the meat industry to inhibit the growth of food-borne pathogens in cooked processed meat products during storage.
PubMed: 38870594
DOI: 10.1016/j.meatsci.2024.109559 -
Journal of Medicinal Food Jun 2024Antioxidant-related parameters and anti-inflammatory and antimicrobial activities against were assessed in eight North East Spain poplar propolis samples. Propolis...
Antioxidant-related parameters and anti-inflammatory and antimicrobial activities against were assessed in eight North East Spain poplar propolis samples. Propolis extracts (PEs) were obtained using 70% ethanol (PEE) and methanol (PME). Yield and total phenol compounds were higher in PEE. Phenolic acids were analyzed by a high-performance liquid chromatograph-diode array detector. Caffeic and ferulic acids were quantified in all PEE and PME. All samples contained p-coumaric acid (quantified in 6 PEE and in 3 PME). Ascorbic acid was detected in all propolis, but mainly quantified in PME (≤0.37 mg/g PE). Biological properties were tested on PEE. As for antiradical activities, trolox equivalent antioxidant capacity (TEAC) [against 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)], ranged between 578 and 4620 µmol trolox/g, 2,2-diphenyl-1-picrylhydrazyl (DPPH) (against DPPH free radical), between 0.049 and 0.094 mg/mL, antioxidant activity against hydroxyl (OH) radical (AOA), between 0.04 and 11.01 mmol uric acid/g, and oxygen radical absorbance capacity (ORAC) against peroxyl (ROO) radical between 122 and 3282 µmol trolox/g. Results of TEAC, AOA, and ORAC were significantly correlated. IC anti-inflammatory activity ranged from 1.08 to 6.19 mg/mL. Propolis showed higher inhibitory activity against CECT934 and CP101 by agar well diffusion ( < .05) (10.5 and 10.2 mm, respectively) than against CP102 (7.0 mm). Data of this research show that North East Spain propolis may be of interest for pharmaceutical and food industry use.
Topics: Propolis; Anti-Inflammatory Agents; Phenols; Listeria monocytogenes; Antioxidants; Spain; Anti-Infective Agents; Anti-Bacterial Agents; Plant Extracts
PubMed: 38868932
DOI: 10.1089/jmf.2023.0206 -
Microbiology Resource Announcements Jun 2024, a concerning foodborne pathogen, causes severe infections in vulnerable subjects such as pregnant women and the elderly. In this article, we present the complete...
, a concerning foodborne pathogen, causes severe infections in vulnerable subjects such as pregnant women and the elderly. In this article, we present the complete genome sequence of P4_LIS, an isolated from a patient with invasive bacteria infection.
PubMed: 38864617
DOI: 10.1128/mra.01240-23 -
International Journal of Biological... Jun 2024Bacterial cellulose (BC) has been found extensive applications in diverse domains for its exceptional attributes. However, the lack of antibacterial properties hampers...
Bacterial cellulose (BC) has been found extensive applications in diverse domains for its exceptional attributes. However, the lack of antibacterial properties hampers its utilization in food and biomedical sectors. Leucocin, a bacteriocin belonging to class IIa, is synthesized by Leuconostoc that demonstrates potent efficacy against the foodborne pathogen, Listeria monocytogenes. In the current study, co-culturing strategy involving Kosakonia oryzendophytica FY-07 and Leuconostoc carnosum 4010 was used to confer anti-listerial activity to BC, which resulted in the generation of leucocin-containing BC (BC-L). The physical characteristics of BC-L, as determined by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), were similar to the physical characteristics of BC. Notably, the experimental results of disc diffusion and growth curve indicated that the BC-L film exhibited a potent inhibitory effect against L. monocytogenes. Scanning electron microscopy (SEM) showed that BC-L exerts its bactericidal activity by forming pores on the bacterial cell wall. Despite the BC-L antibacterial mechanism, which involves pore formation, the mammalian cell viability remained unaffected by the BC-L film. The measurement results of zeta potential indicated that the properties of BC changed after being loaded with leucocin. Based on these findings, the anti-listerial BC-L generated through this co-culture system holds promise as a novel effective antimicrobial agent for applications in meat product preservation and packaging.
PubMed: 38857722
DOI: 10.1016/j.ijbiomac.2024.133047 -
Probiotics and Antimicrobial Proteins Jun 2024This study aimed to assess the antibacterial activity and bio-preservation capability of bacteriocin-producing LAB isolated from Ethiopian traditional fermented dairy...
This study aimed to assess the antibacterial activity and bio-preservation capability of bacteriocin-producing LAB isolated from Ethiopian traditional fermented dairy products in raw milk from Jimma town. Bacteriocin-producing LAB were tested for their antimicrobial activity against various foodborne pathogens, including Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, and Salmonella typhimurium. The results showed that probiotic LAB isolates inhibited foodborne pathogens (E. coli, S. aureus, and L. monocytogenes), with inhibition zones ranging from 22.00 ± 0.57 to 34.13 ± 0.57. Enterococcus faecium and Lactococcus lactis demonstrated possible antagonistic effects against E. coli, while Pediococcus pentosaceus had a 34.13 ± 0.57 mm inhibitory zone against Pseudomonas aeruginosa. The isolates also showed co-aggregation potential with the pathogens, with Lactococcus lactis isolates and their combinations demonstrating the best co-aggregation capabilities against the investigated pathogens. The bio-preservative assay showed that putative probiotic isolates (L. lactis JULABE35, E. faecium JULABE 23, and P. pentosaceus JULABE05) were efficient in decreasing Listeria monocytogenes in raw milk. After 7-8 days, milk samples diagnosed with these isolates showed complete reduction of Listeria monocytogenes. The bio-preservation capability of bacteriocin-producing LAB on raw milk extended the shelf life of milk at 4 °C storage for ten days, compared to six days for milk samples without probiotic LAB. The milk samples preserved with probiotic and bacteriocin-producing isolates showed good proximate analysis, showing significant variation with milk kept without bacteriocin-producing isolates. The isolated chemicals employed in this study can be used as food additives or food preservatives, indicating potential applications in Ethiopian traditional fermented dairy products.
PubMed: 38856908
DOI: 10.1007/s12602-024-10272-w -
Frontiers in Veterinary Science 2024Examining the microbiological characteristics of pet food is imperative to safeguard the health and well-being of companion animals, pet owners, and the surrounding...
Examining the microbiological characteristics of pet food is imperative to safeguard the health and well-being of companion animals, pet owners, and the surrounding environment. Domestic animals, known for carrying harmful microorganisms, pose a significant health risk, especially in close proximity to people and children. Notably, no studies have previously investigated pet food quality in the Gulf Cooperation Council countries, in particular, the United Arab Emirates (UAE). This study examined the microbiological quality of all stock keeping units (SKUs) of pet foods marketed in UAE ( = 118). Parameters assessed include Total Aerobic Microbial Count (TAMC), , Total Yeast and Mold Count (TYMC), , , and species. Among the 118 samples, 33 (28%) exceeded the acceptable TAMC limit of 10 CFU/g, highlighting significant variations based on manufacturers and ingredients. Eight samples (7%) surpassed the maximum limit of 3 × 10 CFU/g. TYMC levels exhibited variation, with 33 (28%) exceeding the limit of 10 CFU/g. was identified in 44 (37%) of the samples, while was not detected. contamination was observed in 28 (24%) of the samples. Statistical analyses revealed associations between pet food characteristics and microbial quality, underscoring the imperative for international standards to ensure the safety of pet food. These findings carry significant implications for pet owners, regulatory bodies, and the pet food industry, emphasizing the need for ongoing efforts to enhance the overall quality and safety of pet food products.
PubMed: 38855408
DOI: 10.3389/fvets.2024.1389981 -
BioRxiv : the Preprint Server For... May 2024Attenuated strains of the intracellular pathogen can deliver genetically encoded payloads inside tumor cells. preferentially accumulates and propagates inside...
Attenuated strains of the intracellular pathogen can deliver genetically encoded payloads inside tumor cells. preferentially accumulates and propagates inside immune-suppressed tumor microenvironments. To maximize the payload impact in tumors and minimize damage to healthy tissues, it is desirable to induce payload synthesis when bacteria are eliminated from the healthy tissues but are grown to high numbers intratumorally. Here, we have engineered a tightly controlled gene expression system for intracellular inducible with a cumin derivative, cumate. Upon cumate addition, expression of a reporter gene is increased in growing by 80-fold, and in intracellular in murine tumors by 10-fold. This study demonstrates the feasibility of activating gene expression in intracellular bacteria in live animals using an edible inducer. The system is expected to enhance the efficacy and safety of the attenuated strains as antitumor payload delivery bacterial drones.
PubMed: 38853860
DOI: 10.1101/2024.05.28.596178 -
International Journal of Food... Aug 2024Despite the wide variety of native and exotic fruits in Brazil, there is limited understanding of their ability to support pathogens during storage. This study aimed to...
Despite the wide variety of native and exotic fruits in Brazil, there is limited understanding of their ability to support pathogens during storage. This study aimed to evaluate the behavior of Salmonella enterica and Listeria monocytogenes inoculated into the pulp of eight fruits native and exotic to Brazil: Jenipapo (Genipa americana L.), Umbu (Spondias tuberosa Arruda), Maná (Solanum sessiliflorum), Cajá-manga (Spondias dulcis), Physalis (Physalis angulata L.), Feijoa (Acca sellowiana), Cupuaçu (Theobroma grandiflorum) (average pH < 3.3) and in a low acidy fruit: Abiu (Pouteria caimito) (pH 6.11). The pathogens were inoculated into the different fruits and stored at 10, 20, 30 and 37 °C for up to 12 h and 6 days, respectively. Among the fruits evaluated, Abiu was the only one that allowed Salmonella growth, showing higher δ-values at 20 and 30 °C (5.6 log CFU/g for both temperatures). For Physalis and Feijoa, there was a small reduction in the pathogen concentration (<1 log-cycle), mainly at 10 and 20 °C, indicating its ability to remain in the matrices. For the other fruits, notable negative δ-values were obtained, indicating a tendency towards microbial inactivation. The survival potential was significantly affected by temperature in Abiu, Maná, Cupuaçu, and Cajá-manga (p < 0.05). The same phenomena regarding δ-value were observed for L. monocytogenes population, with the greatest survival potential observed at 20 °C in Abiu (3.3 log CFU/g). Regarding the exponential growth rates in Abiu, the highest values were observed at 30 and 37 °C, both for Salmonella (4.6 and 4.9 log (CFU/g)/day, respectively) and for L. monocytogenes (2.8 and 2.7 log (CFU/g)/day, respectively), with no significant difference between both temperatures. Regarding microbial inactivation, L. monocytogenes showed greater resistance than Salmonella in practically all matrices. Jenipapo and Umbu were the pulps that, in general, had the greatest effect on reducing the population of pathogens. Furthermore, the increase in storage temperature seems to favor the increase on inactivation rates. In conclusion, Salmonella and L. monocytogenes can grow only in Abiu pulp, although they can survive in some acidic tropical fruits kept at refrigeration and abusive temperatures.
Topics: Salmonella enterica; Listeria monocytogenes; Fruit; Brazil; Food Microbiology; Temperature; Colony Count, Microbial; Food Contamination; Food Storage
PubMed: 38851046
DOI: 10.1016/j.ijfoodmicro.2024.110783