Agents Of Foodborne Diseases Research Articles

Kinetics of Staphylococcus aureus growth and Enterotoxin A production in milk under shaking and static conditions

Numerous studies on bacterial growth or survival predictive models have been conducted since the establishment of predictive microbiology. However, limited research focused on the prediction of bacteria-producing enterotoxins, which are often the causative agents of food-borne diseases. This study aimed to determine an appropriate kinetic model of staphylococcal enterotoxin A (SEA) production in milk after contamination with Staphylococcus aureus. An S. aureus strain producing SEA was inoculated into milk with an initial inoculum concentration of approximately 3.0 log CFU/mL. All samples were incubated for 30–48 h at 20 °C ± 1 °C, 28 °C ± 1 °C, and 36 °C ± 1 °C separately under shaking or static conditions. Duplicate samples were carried out at appropriate intervals to count the number of S. aureus colonies and detect the concentration of SEA. Experimental results showed that the SEA concentration curves under all experimental conditions were sigmoidal and consisted of three phases: lag, exponential, and stationary. Thus, the modified Gompertz model was used to describe the profile of SEA concentration in milk during the incubation. A good fitting accuracy (R2 > 0.97) indicated that the modified Gompertz model was appropriate. In addition to temperature, shaking during incubation also affected the maximal production rate of SEA and the maximal SEA concentrations, and shortened the lag phase at lower incubation temperatures, suggesting that the mechanical movements (e.g., stirring, pumping, and flowing) during the milk processing would increase the risk of SEA occurrence. Besides, the time to detection (TTD) of SEA was found to range from 3 to 24.5 h at temperatures of 36 °C ± 1 °C–20 °C ± 1 °C, at which time the concentrations of S. aureus ranging from 5.0 log CFU/mL–6.9 log CFU/mL at the TTD. This study contributed to understanding the kinetics of SEA production and the possible factors affecting the synthesis of SEA during the manufacturing of liquid foods, such as milk.

Evaluation of a rapid detection method of Salmonella in comparison with the culture method and microbiological quality in fish from the Brazilian Amazon

Abstract Microbiological safety of fish is a concern of consumers, industries and regulatory agencies worldwide. Among the pathogenic microorganisms, Salmonella spp. is one of the main agents of foodborne diseases and should be absent in animal products. Rapid and accurate identification of pathogens in the supply chain is important for both quality assurance and tracking infectious agents within the chain. In this context, this study aimed to evaluate the equivalence of two rapid detection tests, as alternative methods to the conventional Salmonella detection method, as well as to verify the microbiological quality parameters of two commercially important fish species in the Amazon biome. The plate count of aerobic bacteria ranged from 7.76 x 104 to 8.71 x 107 CFU.g-1 for mesophiles and 1.70 x 106 to 4.27 x 108 CFU.g-1 for psychrotrophic whereas the maximum for this group of microorganisms in fresh fish is 106 CFU.g-1. Regarding the Staphylococcus count, the two species presented variations between 1.35 x 104 to 1.51 x 105 CFU.g-1. This represents unsatisfactory conditions of handling, storage and conservation of fish species. The immunoenzymatic and molecular methods have been shown to be reliable, fast and effective in the detection of Salmonella and for its high index of agreement with the conventional detection method. We also emphasize the convenience of multiplex PCR application due to the high sensitivity, specificity, speed and accuracy of Salmonella detection.

Multiplex PCR for the Identification of Pathogenic Listeria in Flammulina velutipes Plant Based on Novel Specific Targets Revealed by Pan-Genome Analysis

Listeria spp. is an important foodborne disease agent, often found in the fresh mushroom (Flammulina velutipes) and its production environment. The aim of this study was to develop multiplex PCR for rapid identification of Listeria monocytogenes and Listeria ivanovii, and nonpathogenic Listeria in F. velutipes plants. Pan-genome analysis was first used to identify five novel Listeria-specific targets: one for the Listeria genus, one for L. monocytogenes, and three for L. ivanovii. Primers for the novel targets were highly specific in individual reactions. The detection limits were 103–104 CFU/mL, meeting the requirements of molecular detection. A mPCR assay for the identification of pathogenic Listeria, with primers targeting the novel genes specific for Listeria genus (LMOSLCC2755_0944), L. monocytogenes (LMOSLCC2755_0090), and L. ivanovii (queT_1) was then designed. The assay specificity was robustly verified by analyzing nonpathogenic Listeria and non-Listeria spp. strains. The determined detection limits were 2.0 × 103 CFU/mL for L. monocytogenes and 3.4 × 103 CFU/mL for L. ivanovii, for pure culture analysis. Further, the assay detected 7.6 × 104 to 7.6 × 100 CFU/10 g of pathogenic Listeria spiked into F. velutipes samples following 4–12 h enrichment. The assay feasibility was evaluated by comparing with a traditional culture-based method, by analyzing 129 samples collected from different F. velutipes plants. The prevalence of Listeria spp. and L. monocytogenes was 58.1% and 41.1%, respectively. The calculated κ factors for Listeria spp., L. monocytogenes, and L. ivanovii were 0.97, 0.97, and 1, respectively. The results of the novel mPCR assay were highly consistent with those of the culture-based method. The new assay thus will allow rapid, specific, and accurate detection and monitoring of pathogenic Listeria in food and its production environment.

Prevalence and Antibiogram of Salmonella Species Isolated from Snail (Archachatina marginata) Sold in Port Harcourt, Rivers State, Nigeria

Increase in microbial population especially Salmonella species in food due to improper handling, storage and exposure to contaminants can raise public health concerns when consumed without adequate processing. This study evaluates the prevalence and antibiogram of Salmonella species associated with the giant land Snail (Archachatina marginata) sold in markets around Port Harcourt metropolis. A total number of seventy two (72) samples of land snail were collected from three markets; Creek Road, Mile one and Rumuokoro. The samples were labelled and transported in an ice packed coolers to the laboratory for analyses. Standard microbiological protocols were employed to determine the microbial load and species of the various parts (intestine, meat and fluid) of the snail samples after shucking. Antibiotics sensitivity profile testing of the isolated and identified Salmonella species were carried out as recommended by Clinical Laboratory Standard Institute (CLSI) and statistical analyses using one way ANOVA and all pairs Turkey-Kramer. Results from the study showed that the highest total heterotrophic bacteria count (THBC) of 8.6x106CFU/g was obtained in the snail intestine sourced from Creek road market while THBCs of 8.2x106 CFU/g and 7.3x106 CFU/g were from Mile one and Rumuokoro markets respectively. THBCs of meat from the markets ranged from 4.3-5.4x106 CFU/g and 3.7-4.9x106CFU/ml in fluid with Rumuokoro having the least occurrence respectively. Mean Salmonella counts (MSCs) ranged from 0.4-3.6 x103 CFU/g, with least count obtained from Rumuokoro and Mile 1 markets. Similarly, least MSCs in fluid and intestine were obtained from Rumuokoro and Mile 1 whereas Creek road Market had the highest respectively. Three species of Salmonella; S. arizonae, S. gallinarum and S. typhi were predominant in addition to other species such as Vibrio spp,, Bacillus spp., Staphylococcus spp., Shigella spp., Pseudomonas spp., Enterobacter spp., E. coli, Micrococcus spp., Acinetobacter spp., Klebsiella spp. and Listeria spp identified using both conventional and molecular method. Antibiogram profile revealed that all the identified Salmonella species were susceptible to Ofloxacin and Ciprofloxacin but strongly resistance to Cetazidime and Gentamicin. The diversity and elevated microbial load observed from this study calls for caution in handling and processing of snails since most of these bacteria may become aetiologic agents of several food-borne diseases and other pathological conditions. As a necessity, good quality control measures and proper chemotherapy should be administered to patients with signs and symptoms of food borne illness emanating from consumption of snail.

Salmonella Effector SpvB Disrupts Intestinal Epithelial Barrier Integrity for Bacterial Translocation.

Salmonella are common enteric bacterial pathogens that infect both humans and animals. Intestinal epithelial barrier, formed by a single layer of epithelial cells and apical junctional complex (AJC), plays a crucial role in host defense against enteric pathogens to prevent bacterial translocation. However, the underlying mechanisms of intestinal epithelial barrier dysfunction caused by Salmonella are poorly understood. It is found that a locus termed Salmonella plasmid virulence (spv) gene exists extensively in clinically important Salmonella serovars. SpvB is a key effector encoded within this locus, and closely related to Salmonella pathogenicity such as interfering with autophagy and iron homeostasis. To investigate the interaction between SpvB and intestinal epithelial barrier and elucidate the underlying molecular mechanism, we used the typical foodborne disease agent Salmonella enterica serovar Typhimurium (Salmonella typhimurium) carrying spvB or not to construct infection models in vivo and in vitro. C57BL/6 mice were orally challenged with S. typhimurium wild-type strain SL1344 or spvB-deficient mutant strain SL1344-ΔspvB. Caco-2 cell monolayer model, as a widely used model to mimic the human intestinal epithelium in vitro, was infected with SL1344, SL1344-ΔspvB, or spvB complementary strain SL1344-c-ΔspvB, respectively. The results showed that SpvB enhanced bacterial pathogenicity during S. typhimurium infection in vivo, and contributed to intestinal epithelial barrier dysfunction in both infection systems. This SpvB-mediated barrier dysfunction was attributed to the cellular redistribution of Claudin-1, Occludin, and E-cadherin junctional proteins. Moreover, by using pharmacological inhibitors, we found that F-actin rearrangement and suppression of protein kinase C (PKC) signaling pathway were involved in SpvB-mediated barrier dysfunction. In conclusion, the study reveals the contribution of Salmonella effector SpvB to the dysfunction of intestinal epithelial barrier integrity, which facilitates bacterial translocation via the paracellular route to promote Salmonella systemic dissemination. Our findings broaden the understanding of host–pathogen interactions in salmonellosis, and provide new strategies for the therapy in limiting bacterial dissemination during infection.

Outbreak of Cyclosporiasis in Korean Travelers Returning from Nepal.

Cyclospora cayetanensis is an apicomplexan protozoan and is one of the most common pathogens causing chronic diarrhea worldwide. Eight stool samples with diarrheal symptom out of 18 Korean residents who traveled to Nepal were obtained, and examined for 25 enteropathogens including 16 bacterial species, 5 viral species, and 4 protozoans in stool samples as causative agents of water-borne and food-borne disease. Only C. cayetanensis was detected by nested PCR, and 3 PCR-positive samples were sequenced to confirm species identification. However, the oocysts of C. cayetanensis in fecal samples could not be detected by direct microscopy of the stained sample. As far as we know, this is the first report of a group infection with C. cayetanensis from a traveler visiting Nepal, and the second report of a traveler’s diarrhea by C. cayetanensis imported in Korea.

Clostridium perfringens as Foodborne Pathogen in Broiler Production: Pathophysiology and Potential Strategies for Controlling Necrotic Enteritis.

Simple SummaryClostridium perfringens (Cp.) is an important microorganism from a clinical, food and veterinary point of view. In humans, it is the causal agent of foodborne diseases, commonly associated with the consumption of chicken meat, while, in broilers, it causes clinical or subclinical necrotic enteritis. Cp. has the ability to synthesize toxins, bacteriocins, and enzymes of different nature, which modify the anatomical structure of the intestinal mucosa, enterocytes, and the cellular matrix altering the physiological activities of the gastrointestinal tract, resulting in gastrointestinal disorders, diarrhea, and if it is not attended, death, resulting in significant economic losses for the poultry industry. Food additives such as probiotics, prebiotics, synbiotics, essential oils, organic acids, and enzymes have been presented as alternatives to mitigate the incidence of necrotic enteritis (NE) in broilers, by improving the overall intestinal health and producing healthy birds for consumption. It is imperative to conduct further research on alternatives and efficient products to modulate the intestinal microbiota, and to know the role they play in the immune system, complementing the current demand, economic gain, and keeping the ecology.Clostridium perfringens (Cp.) is the cause of human foodborne desease. Meat and poultry products are identified as the main source of infection for humans. Cp. can be found in poultry litter, feces, soil, dust, and healthy birds’ intestinal contents. Cp. strains are known to secrete over 20 identified toxins and enzymes that could potentially be the principal virulence factors, capable of degrading mucin, affecting enterocytes, and the small intestine epithelium, involved in necrotic enteritis (NE) pathophysiology, also leading to immunological responses, microbiota modification and anatomical changes. Different environmental and dietary factors can determine the colonization of this microorganism. It has been observed that the incidence of Cp-associated to NE in broilers has increased in countries that have stopped using antibiotic growth promoters. Since the banning of such antibiotic growth promoters, several strategies for Cp. control have been proposed, including dietary modifications, probiotics, prebiotics, synbiotics, phytogenics, organic acids, and vaccines. However, there are aspects of the pathology that still need to be clarified to establish better actions to control and prevention. This paper reviews the current knowledge about Cp. as foodborne pathogen, the pathophysiology of NE, and recent findings on potential strategies for its control.

Antimicrobial Resistance in Salmonella Serovars Isolated From an Egg-Producing Region in Brazil

ABSTRACT Fowl paratyphoid infections are caused by different Salmonella serovars that can affect a wide range of hosts. Due to its complex epidemiology, Salmonella serovar identification is crucial for the development and implementation of monitoring and control programs in poultry farms. Moreover, the characterization of the antimicrobial resistance profiles of Salmonella strains isolated from livestock is relevant to public health because they are a common causative agent of foodborne diseases. The objective of this study was to investigate the presence of Salmonella spp. and to identify the antimicrobial resistance profiles of strains isolated in the midwestern region of Sao Paulo state, which accounts for the highest production of table eggs in Brazil. For this purpose, 2008 fecal samples were collected on 151 commercial layer farms and submitted to microbiological analyses. Twenty-two serovars were isolated from 80 (52.9%) farms, among which S. Mbandaka and S. Braenderup were the most prevalent. All isolates expressed resistance to at least one of the 23 antimicrobials tested, and the highest resistance rates were determined against streptomycin (93.5%) and sulfonamide (84.6%). Moreover, multidrug resistance was observed in 41% of the isolates and the maximum drug resistance profile was against ten different antimicrobials. Therefore, the identification of Salmonella serovars in poultry production provides epidemiological knowledge to develop prevention and control measures in order to ensure poultry health and to prevent human infection by multiresistant strains.

Detection of Kudoa hexapunctata and Kudoa neothunni from retail raw tuna in Japan using a novel duplex polymerase chain reaction

Kudoa hexapunctata was taxonomically separated from Kudoa neothunni, but their main host is tuna. K. hexapunctata has been identified as causative agent of foodborne diseases associated with the ingestion of raw Pacific bluefin tuna (PBT) in Japan, but K. neothunni has not. Therefore, it is clinically and epidemiologically important to detect and distinguish these two species. In the present study, we developed a novel duplex polymerase chain reaction (dPCR) targeting the 28S rRNA gene sequences of K. hexapunctata and K. neothunni. The dPCR amplified the desired genetic regions of each species, and the detection limit was 10 copies/reaction. A total of 36 retail tuna samples from different fishing ports were purchased and tested by dPCR. Thirty-one tested positive for K. hexapunctata and four tested positive for K. neothunni. Several retail PBT samples were examined in some of the fishing ports, and among these samples, the detection rates of K. hexapunctata was higher than 85%, and the rates were similar between wild and farmed PBT. The detection rates of K. hexapunctata in wild and farmed retail PBT were 75% and 71%, respectively, in May. However, the rates in June and July were 100% for both. K. hexapunctata and K. neothunni myxospores were not observed in the dPCR-positive samples, except in juvenile PBT, suggesting that the number of parasites was insufficient to cause foodborne disease. Thus, dPCR is a useful method for detecting and distinguishing K. hexapunctata and K. neothunni, and can be used in epidemiological studies of these parasites.

EVALUATION OF ANTIMICROBIAL AND ANTIOXIDANT PROPERTIES OF MANGIFERA INDICA BARK EXTRACTS TO PROLONG THE SHELF LIFE OF FRUITS AND FOOD PRODUCTS

Processed food products can be contaminated by a variety of pathogenic and spoilage microbes. Those are the causative agents of foodborne diseases and cause significant economic losses in the food industries and human health. This was the basis of the present study, carried out with an objective to investigate the antibacterial and antifungal potentials of Mangifera indica bark extract. The antimicrobial activity of plant extracts and phytochemicals was evaluated with antibiotic susceptible and resistant microorganisms. An attempt was made in this study to evaluate these properties to prolong the shelf life of fruits and vegetables at the time of transportation and storage. Parts of the Mango plants have multifarious uses as traditional and asthetic values as well as medicinal implications. Antioxidant property was also evaluated by DPPH method. Methanolic extract of mangifera bark was used to evaluate the properties of phytochemicals and their role as an effective antioxidant and antimicrobial agent. The antibacterial activity was tested against one Gram-positive-Staphylococcus aureus, and three Gram-negative-Escherichia coli, Pseudomonas aeruginosa, Salmonella human pathogenic bacteria; and two fungal strains― Candida albicans and Aspergilus niger. After evaluation, methanolic extract of Mangifera bark the presence of phytochemicals like, alkaloids, glycosides, phenolic compounds, tannins and steroids. Zone of inhibition of extracts were compared with that of different standards like oxytetracycline, levofloxacin for antibacterial activity and fluconazole for antifungal activity. The results showed that the remarkable zone of inhibition against the bacterial growth ranged from 14 to 15 mm for pathogenic strain of bacteria. The zone of inhibition was observed first time of around 13 mm against the fungal strain. After the preliminary screening for antimicrobial activity by agar well diffusion method, MIC & MBC were also determined against above mentioned bacteria ranged from 3.125 to 6.25 μg/mL. However MBC ranges from 1.562 to 3.125 μg/mL. The parameter IC50 (efficient concentration|| value) is used for the interpretation of the results from the DPPH method and the IC50 value for Mangifera indica is 94.04 μg/ml. Therefore, this plant can be used to isolate bioactive natural products and can be employed to control the food spoilage and to improve the quality of fruits and food products and may also play a vital role for the improvement of quality products for food industries. Keywords: Mango bark, Antioxidant, Antimicrobial, hytochemicals, IC50, MIC, MBC

Medicinal Value of Croton macrostachyus and Solanum incanum against Causative Agent of Foodborne Diseases

Medicinal Value of Croton macrostachyus and Solanum incanum against Causative Agent of Foodborne Diseases

Risk of Water and Food-Borne Communicable Diseases in Travelers Entering Korea.

ObjectivesIt was supposed to analyze status and affecting factors in water and food-borne communicable disease by screening entrants with diarrhea symptom at the point of entry in KoreaMethodsSymptomatic travelers with water and food-borne communicable diseases who entered Korea were diagnosed by a health declaration and detection of causative agents in water and food using laboratory tests. Among those entered in 2017, the affecting factors in the incidence of communicable diseases among those who had diarrhea at the entry into Korea, were analyzed, with frequency and chi-square test.ResultsThe number of travel entrants with gastrointestinal communicable diseases increased by 40.19% from 2013 to 2017. The percentage of causative agents of water and food-borne communicable diseases was the highest at 69.2% from July to September. The rate of detection of causative agents of communicable disease pathogens in travelers from Southeast Asia entering Korea was 70.2%, which was higher than people arriving from East Asia and Central Asia (57.5%; p < 0.001).ConclusionThe positive ratio of causative agents of water and food-borne communicable diseases was high among travelers that had entered Korea from July to September, with a high number among entrants from Southeast Asia. Based on the positive detection of causative agents, the entry period and countries visited were statistically significant affecting factors (p < 0.001).

Rapid and quantitative detection of viable emetic Bacillus cereus by PMA-qPCR assay in milk

Emetic Bacillus cereus is one of the causative agents of foodborne diseases which can cause vomiting-type food poisoning after ingestion of contaminated food. To minimize B. cereus food poisoning, propidium monoazide (PMA) combined with quantitative polymerase chain reaction (qPCR) called PMA-qPCR was applied for detecting viable emetic B. cereus in milk. The cereulide synthetase gene of emetic B. cereus (cesB) was chosen for the primer, and PMA treatment was optimized at 3 μg/mL to inhibit the PCR amplification of DNA from dead cells. Under optimized assay parameters, the limit of detection (LOD) using this method were 102 CFU/mL in both pure culture and in spiked milk matrix. The cycle threshold (Ct) values obtained for this assay was not significantly affected by the presence of non-target bacteria such as E. coli O157:H7 which indicated the high selectivity of the assay for emetic B. cereus. The PMA-qPCR assay used in this study has the potential for sensitive detection of viable emetic B. cereus in milk.

Occurrence of Foodborne Agents at Food Service Facilities in the Czech Republic

Contamination of food service facilities in the Czech Republic by foodborne agents was determined. Bacillus cereus, Staphylococcus aureus, and Escherichia coli were detected in almost 50% of samples. The occurrence of B. cereus, S. aureus, and E. coli depended on the season of the year. Regular monitoring of food service facilities for agents of foodborne disease is necessary.

HYGIENIC PRACTICES AND BACTERIOLOGICAL QUALITY OF MILK: A REVIEW

Anyone dealing with raw milk on a day-to-day basis knows very well how quickly it becomes sour when it is stored for long periods at high ambient temperatures prevalent in tropical and subtropical countries. This is because the inherent lactic acid bacteria and contaminating microorganisms from storage vessels or the environment break down the lactose in milk into lactic acid. When sufficient lactic acid has accumulated, the milk becomes sour and coagulates, much like when you add sufficient lemon juice to fresh milk. Raw milk that contains too much lactic acid, even if it does not appear to be curdled, will coagulate when heated. So far, many pathogenic microorganisms, such as Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, Salmonella sp., and Candida sp., have been reported as the causal agents of food-borne diseases and/or food spoilage. Contamination of raw and/or processed foods usually occurs during the production, sale, and distribution of the foods. Therefore, the objective of this review paper was to investigate hygienic practices and bacteriological quality of milk. In order to produce good quality dairy, establishment of standards, use of effective enforcement, education of dairy personnel’s and farmers on various aspects of milk hygiene and handling technique is important.

Current insights on Arcobacter butzleri in food chain

Arcobacter butzleri is an emerging pathogen with a global distribution, frequently found in the food chain. Its wide spread and association with human illness may point this bacterium as a possible causative agent of foodborne diseases usually associated with unknown etiology. Thus, the true pathogenic potential of A. butzleri and the associated risk of disease development must be clarified. Since its dispersion throughout the food chain is clear, this points toward a potential public health problem due to contaminated food and water, which is strengthened by the ability of this microorganism to survive in food products and water and by its resistance to stress created during food storage and processing.

Modeling shellfish harvest policies for food safety: Wild oyster harvest restrictions to prevent foodborne Vibrio vulnificus

Vibrio vulnificus has been identified as one of the main causative agents of foodborne disease associated with shellfish consumption. Infections of V. vulnificus increase during the summer months due to higher densities of the bacteria in warmer water and inappropriate handling of shellfish. In Florida, the daily harvest period is regulated to control the length of time between shellfish harvest and processing, and this harvest period has been recently reduced during the summer months to decrease the risk of foodborne disease. Adoption of this public health policy can affect the profitability and economic sustainability of wild oyster harvesters, especially in resource-dependent coastal communities. This study develops a dynamic and stochastic bioeconomic model to assess the impact of this policy on fishers’ harvest and revenues, and weighs that impact against the policy’s potential public health benefits. Our results show that fishers will experience reduced harvests early in the season due to the shorter harvest hours, but this initial loss is partially recouped later in the season as harvests remain high for longer than they would have if the policy were not in place. This study highlights the relationship between food safety interventions and management of fishery resources, and provides a comprehensive framework for evaluating the costs and benefits associated with such interventions.

Estimates of the 2015 global and regional disease burden from four foodborne metals – arsenic, cadmium, lead and methylmercury

The impact of foodborne metals on the burden of disease has been largely overlooked, in comparison to the attention on acute diseases associated with infectious foodborne agents. Four articles in this special section describe in detail the burden of disease from foodborne lead, methylmercury, arsenic, and cadmium. Ingested lead and methylmercury are causally associated with lifelong intellectual disability. Long term ingestion of arsenic is causally associated with an increased risk of cancer. Long term ingestion of cadmium is causally associated with an increased risk of late stage chronic kidney disease. This article presents an overview of the burden of disease from these four foodborne metals and discusses them in the context of the World Health Organization's initiative to estimate the global burden of foodborne disease. The results indicate that in 2015, ingestion of arsenic, methylmercury, lead, and cadmium resulted in more than 1 million illnesses, over 56,000 deaths, and more than 9 million disability-adjusted life years (DALYs) worldwide. The greatest impact on DALYs was in the Western Pacific B subregion. All of the metals were found to have high DALYs per case in comparison with other foodborne disease agents, including infectious and parasitic agents. In addition, lead, arsenic, and methylmercury were found to have high DALYs per 100,000 population in comparison to other foodborne disease agents.

Antibacterial, Preservative, and Mutagenic Potential of Copaifera spp. Oleoresins Against Causative Agents of Foodborne Diseases.

Foodborne diseases (FBDs) are a serious public health concern worldwide. In this scenario, preservatives based on natural products, especially plants, have attracted researchers' attention because they offer potential antimicrobial action as well as reduced health impact. The genus Copaifera spp., which is native of tropical South America and West Africa, contains several species for which pharmacological activities, including antibacterial effects, have been described. On the basis of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antibiofilm activity (inhibition and eradication), preservative capacity, and Ames test, we evaluated the antibacterial, preservative, and mutagenic potential of Copaifera spp. oleoresins against the causative agents of FBDs. The Copaifera duckei, Copaifera reticulata, Copaifera paupera, and Copaifera pubiflora oleoresins displayed promising MIC/MBC values-from 12.5 to 100 μg/mL-against Staphylococcus aureus (American Type Culture Collection [ATCC] 29213), Listeria monocytogenes (ATCC 15313), and Bacillus cereus (ATCC 14579). C. duckei, C. reticulata, C. paupera, and C. pubiflora oleoresin concentrations ranging from 25 to 200 μg/mL and from 100 to 400 μg/mL inhibited biofilm formation and eradicated biofilms, respectively. The oleoresins did not exert mutagenic effects and had superior food preservative action to sodium benzoate (positive control). In conclusion, Copaifera oleoresins exhibit potential antibacterial activity and are not mutagenic, which makes them a promising source to develop novel natural food preservatives to inhibit foodborne pathogens.

Development of microsatellite loci in zoonotic tapeworm Dibothriocephalus latus (Linnaeus, 1758), Lühe, 1899 (syn. Diphyllobothrium latum) using microsatellite library screening

The broad fish tapeworm Dibothriocephalus latus is a causative agent of human food-borne disease called diphyllobothriosis. Medical importance, scattered geographical distribution and unknown origin of D. latus in Europe and North America make this species to be an interesting model for population genetics. Microsatellite markers were originally designed by library screening using NGS approach and validated as tools for future studies on population genetics of D. latus. Out of 122 candidates selected after NGS analysis, 110 yielded PCR products of the expected size, and in 78 of them, a declared repetitive motif was confirmed by Sanger sequencing. After the fragment analysis, six loci were proved to be polymorphic and tested for observed (Ho) and expected (He) heterozygosity, and deviations from Hardy-Weinberg equilibrium (HWE). They promise future application in studies on genetic interrelationships, origin and migratory routes of this medically important emerging tapeworm.