Causative Agents Of Foodborne Diseases Research Articles

Distribution ofListeria spp., andListeria monocytogenesin micro- and small-scale meat product processing plants

Listeriosis is a disease caused by L. monocytogenes, a relevant microorganism as a causative agent of foodborne diseases - FBD. This study aimed to evaluate the distribution of Listeria spp., and L. monocytogenes in different production areas in two small plants (A and B) and two micro-food processing plants (C and D) producing meat derivatives, located in different cities of Colombia. The methodology implemented was i. The analysis of sampling points is based on a harmonised tool. ii. Four samplings in each production plant between 2019 and 2020. iii. Isolation and identification of microorganisms through conventional microbiology, a semi-automated system, molecular serotyping and clonal characterisation by ERIC-PCR. L. monocytogenes frequency in the production plants belonging to the study ranged between 5.9 and 28.6 %; for Listeria spp., plants A and D had isolated, plant A had the highest proportion, while for L. monocytogenes geno-serotypes found were: 1/2a, 1/2c, 4a-4c, 4b, 4d - 4e, with geno-serotype 4b as the most frequent. Furthermore, possible persistent isolates were detected in plant C as the feasible sources of contamination, based on failures in flow management, raw material contaminated with L. monocytogenes, lack of standardised cooking processes and transfer of the microorganism through equipment and surfaces. Finally, in three of the four production plants assayed, L. monocytogenes or Listeria spp. were present in the packaging area in some of the samples taken during the study, which calls for increased and frequent monitoring, as well as constant technical support for the control of L. monocytogenes in micro and small-scale production plants.

Retrospective Screening of Anthrax-like Disease Induced by Bacillus tropicus str. JMT from Chinese Soft-Shell Turtles in Taiwan.

Bacillus cereus is ubiquitous in the environment and a well-known causative agent of foodborne disease. Surprisingly, more and more emerging strains of atypical B. cereus have been identified and related to severe disease in humans and mammals such as chimpanzees, apes, and bovine. Recently, the atypical B. cereus isolates, which mainly derive from North America and Africa, have drawn great attention due to the potential risk of zoonosis. The cluster of B. cereus carries several anthrax-like virulent genes that are implicated in lethal disease. However, in non-mammals, the distribution of atypical B. cereus is still unknown. In this study, we conducted a retrospective screening of the 32 isolates of Bacillus spp. from diseased Chinese soft-shelled turtles from 2016 to 2020. To recognize the causative agent, we used various methods, such as sequencing analysis using PCR-amplification of the 16S rRNA gene, multiplex PCR for discriminating, and colony morphology by following previous studies. Furthermore, the digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values were calculated, respectively, below the 70 and 96% cutoff to define species boundaries. According to the summarized results, the pathogen is taxonomically classified as Bacillus tropicus str. JMT (previous atypical Bacillus cereus). Subsequently, analyses such as targeting the unique genes using PCR and visual observation of the bacteria under various staining techniques were implemented in our study. Our findings show that all (32/32, 100%) isolates in this retrospective screening share similar phenotypical properties and carry the protective antigen (PA), edema factor (EF), hyaluronic acid (HA), and exopolysaccharide (Bps) genes on their plasmids. In this study, the results indicate that the geographic distribution and host range of B. tropicus were previously underestimated.

A Small‐molecule Inhibitor VM17 Targeting a Transcriptional Regulator HlyU Attenuates the Virulence of Vibrio vulnificus

Vibrio vulnificusis a causative agent of food‐borne diseases including gastroenteritis and life‐threatening septicemia. Exotoxins such as a multifunctional‐autoprocessing repeats‐in‐toxin (MARTX) toxin, a hemolysin, and a phospholipase A2 encoded by rtxA, vvhA, and plpAgenes, respectively, are essential virulence factors. Interestingly, the expression of rtxA, vvhA, and plpA is activated by a transcriptional regulator HlyU. Therefore, HlyU can be an attractive target to control the virulence of V. vulnificus. We performed a high‐throughput screening of 8,364 molecules at 20 µM using Escherichia coli containing HlyU‐expressing and HlyU‐dependent reporter plasmids. A small molecule VM17 exhibiting the most effective HlyU‐inhibiting activity was selected and verified. VM17 did not affect the cellular HlyU levels, indicating that VM17 could inhibit the HlyU activity. The expression of rtxA, vvhA, and plpAin the wild type was significantly reduced in the presence of 20 µM of VM17. Consistent with this, VM17 enhanced the survival rate of the mice infected with V. vulnificus, indicating that the small molecule inhibits the virulence of V. vulnificus in vitroand in vivo. In conclusion, the combined results suggested that VM17 could be a novel lead compound to attenuate the virulence of V. vulnificuswith a low probability of developing resistance.

Genomic and Phenotypic Characteristics for Vibrio vulnificus Infections.

BackgroundVibrio vulnificus (VV) is a causative agent of foodborne diseases with high mortality. The aim of this study was to investigate the genomic and phenotypic profiles of VV.MethodsSix VV isolates were collected and conducted whole-genome sequencing. Biofilm formation and anti-complement killing test were performed to evaluate the pathogenicity. Subsequently, 157 publicly available genomes of VV isolates were selected to determine the evolutionary relationship.ResultsThe resistant genes norM and tet34 were identified in six isolates. A total of 156 virulence genes were identified. However, there is no obvious difference between strains isolated from blood and puncture fluid. The tendency of growth for six isolates decreased with the lapse of time, while the biofilm formation increased. The genes tadC and flp related to Flp pili were found in isolate 25506 and 30896, resulting in more obvious biofilm formation. In addition, the survival rate of 19656 was less than 20% due to lack of one genomic island including virulence genes (impD-H, clpV-1) relevant to type VI secretion system (T6SS). Multi-locus sequence typing (MLST) revealed 95 different STs and 19 novel STs, indicating that the tendency of 163 isolates was sporadic. Further comparative genomics analysis clearly classified 163 isolates into three distinct evolutionary lineages.ConclusionVV infections were sporadic in humans and the environment. Virulence genes impD-H and clpV-1 related to T6SS were associated with pathogenicity phenotype of VV.

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.

Use of Veterinary Vaccines for Livestock as a Strategy to Control Foodborne Parasitic Diseases.

Foodborne diseases (FBDs) are a major concern worldwide since they are associated with high mortality and morbidity in the human population. Among the causative agents of FBDs, Taenia solium, Echinococcus granulosus, Toxoplasma gondii, Cryptosporidium spp., and Trichinella spiralis are listed in the top global risk ranking of foodborne parasites. One common feature between them is that they affect domestic livestock, encompassing an enormous risk to global food production and human health from farm to fork, infecting animals, and people either directly or indirectly. Several approaches have been employed to control FBDs caused by parasites, including veterinary vaccines for livestock. Veterinary vaccines against foodborne parasites not only improve the animal health by controlling animal infections but also contribute to increase public health by controlling an important source of FBDs. In the present review, we discuss the advances in the development of veterinary vaccines for domestic livestock as a strategy to control foodborne parasitic diseases.

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

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.

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.

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.

Thermal inactivation of human norovirus surrogates in oyster homogenate

Human norovirus (HNV) is the most frequent causative agent of foodborne diseases in the US. Raw and undercooked oysters are commonly associated with outbreaks caused by HNV. Many guidelines recommend that shucked oysters be boiled for at least 3 min, but it is not clear this thermal treatment can inactivate HNV. The objective of this research was to evaluate whether this recommendation was sufficient to inactivate two HNV surrogates, murine norovirus (MNV-1) and Tulane virus (TV) in oyster homogenate as well as to determine their thermal inactivation kinetics. Inoculated oyster homogenate was heated in boiling water and circulating water bath at 49 to 67 °C for different time durations. After 3 min of boiling, both MNV-1 and TV titers decreased to below the detection limits. First-order model and Weibull model were used to describe thermal inactivation kinetics. TD = 1 values from Weibull mode are used as an analog to D values in first-order model. The D values of MNV-1 and TD = 1 values ranged from 28.17 to 0.88 min and 26.64 to 0.78 min at 49 to 67 °C, respectively. The D values of TV and TD = 1 values ranged from 18.18 to 1.56 min and 19.35 to 1.56 min at 49 to 63 °C, respectively. The kinetics demonstrated that at temperatures > 58 °C, TV was much more heat sensitive than MNV-1. As the temperature increased over 58 °C, the inactivation of both viruses occurred at a faster rate. Boiling treatment for 3 min as recommended by FDA for cooking shucked oysters, inactivated MNV-1 and TV in oyster homogenate below detection limit. One minute heating of TV at 63 °C or MNV-1 at 67 °C in contaminated oyster homogenate reduced the viral titers below the detection limits. Our research identified effective combinations of time and temperature to inactivate two HNV surrogate viruses, and thus provides insights on thermal processing to reduce the risk of foodborne viral illness outbreaks associated with consumption of oysters.

Random mutagenesis unveils novel host-pathogen interactions during colonic bacterial infections in immunocompromised hosts

Abstract Attaching/Effacing (A/E) pathogens including enteropathogenic Escherichia coli (EPEC), enterohemorrhagic E. coli (EHEC), and the rodent equivalent Citrobacter rodentium (CR) are important causative agents of foodborne diseases. A/E pathogen infections cause severe morbidity and mortality in immunocompromised hosts with low interleukin-22 (IL-22); however, the crucial host-pathogen interactions and the pivotal A/E virulence proteins (effectors) under immunocompromised conditions, remain elusive. We conducted a functional screening of a CR mutant library consisting of ~2,000 mutant strains, generated via transposon-mediated random mutagenesis, and identified several avirulent strains, which abolish CR-induced severe morbidity and mortality in IL-22 knockout (Il22−/−) mice. Recapitulating the attenuated virulence phenotype by the transposon-interrupted mutant strains, genomic deletion of each identified effector in CR dramatically attenuates CR-caused lethality in Il22−/− mice. Interestingly, genetic deletion of each identified effector gene in CR genome exhibits no impact on the colonization and proliferation of CR in the infected animals; however, the deficiencies in these effectors substantially impede the colonic inflammatory response in the CR-infected Il22−/− mice, through distinct cellular and molecular mechanisms. Hence, our findings unveil a set of novel A/E pathogen effectors pathologically relevant to the severe morbidity and mortality in Il22−/− animals, which could provide new strategies to control A/E pathogen infections under the low IL-22 immunocompromised conditions, which are frequently associated with chronic HIV infection, organ transplantation, and other diseases.

High-Quality Complete and Draft Genome Sequences for Three Escherichia spp. and Three Shigella spp. Generated with Pacific Biosciences and Illumina Sequencing and Optical Mapping.

ABSTRACTEscherichia spp., including E. albertii and E. coli, Shigella dysenteriae, and S. flexneri are causative agents of foodborne disease. We report here reference-level whole-genome sequences of E. albertii (2014C-4356), E. coli (2011C-4315 and 2012C-4431), S. dysenteriae (BU53M1), and S. flexneri (94-3007 and 71-2783).

Importancia en Salud Pública y modelamiento de Staphylococcus Aureus en alimentos.

Staphylococcus aureus es uno de los principales agentes causantes de ETA en Colombia y en el mundo. Este microorganismo causa intoxicación, la cual se debe a la ingestión de alimentos contaminados con enterotoxinas termoestables producidas por esta bacteria. Actualmente, existen herramientas predictivas basadas en conceptos matemáticos que permiten estimar del riesgo microbiológico y determinar la vida útil de una matriz alimenticia. Así, se realizó una revisión bibliográfica de la importancia de S. aureus como agente etiológico y de las acciones realizadas a través del tiempo para predecir su comportamiento en un alimento.

Production of hemolysin BL by Bacillus cereus group isolates of dairy origin is associated with whole-genome phylogenetic clade.

BackgroundBacillus cereus group isolates that produce diarrheal or emetic toxins are frequently isolated from raw milk and, in spore form, can survive pasteurization. Several species within the B. cereus group are closely related and cannot be reliably differentiated by established taxonomical criteria. While B. cereus is traditionally recognized as the principal causative agent of foodborne disease in this group, there is a need to better understand the distribution and expression of different toxin and virulence genes among B. cereus group food isolates to facilitate reliable characterization that allows for assessment of the likelihood of a given isolate to cause a foodborne disease.ResultsWe performed whole genome sequencing of 22 B. cereus group dairy isolates, which represented considerable genetic diversity not covered by other isolates characterized to date. Maximum likelihood analysis of these genomes along with 47 reference genomes representing eight validly published species revealed nine phylogenetic clades. Three of these clades were represented by a single species (B. toyonensis –clade V, B. weihenstephanensis – clade VI, B. cytotoxicus - VII), one by two dairy-associated isolates (clade II; representing a putative new species), one by two species (B. mycoides, B. pseudomycoides – clade I) and four by three species (B. cereus, B. thuringiensis, B. anthracis – clades III-a, b, c and IV). Homologues of genes encoding a principal diarrheal enterotoxin (hemolysin BL) were distributed across all, except the B. cytotoxicus clade. Using a lateral flow immunoassay, hemolysin BL was detected in 13 out of 18 isolates that carried hblACD genes. Isolates from clade III-c (which included B. cereus and B. thuringiensis) consistently did not carry hblACD and did not produce hemolysin BL. Isolates from clade IV (B. cereus, B. thuringiensis) consistently carried hblACD and produced hemolysin BL. Compared to others, clade IV was significantly (p = 0.0001) more likely to produce this toxin. Isolates from clade VI (B. weihenstephanensis) carried hblACD homologues, but did not produce hemolysin BL, possibly due to amino acid substitutions in different toxin-encoding genes.ConclusionsOur results demonstrate that production of diarrheal enterotoxin hemolysin BL is neither inclusive nor exclusive to B. cereus sensu stricto, and that phylogenetic classification of isolates may be better than taxonomic identification for assessment of B. cereus group isolates risk for causing a diarrheal foodborne disease.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2883-z) contains supplementary material, which is available to authorized users.

ASSESSMENT OF FOOD MICROBIAL CONTAMINATION BY SALMONELLA REPRESENTATIVES

The spread of Salmonella in foods is important. Microorganisms of the genus Salmonella at present remains one of the most common causative agents of foodborne diseases that pose a threat to humans. In Russia in recent years, noted the leadership of salmonellosis in the flare of disease caused by food transmission of infectious agents. For the past 10 years (2004-2013) the average recorded 48.7 thousand cases of human infection with salmonella with few deaths -. 8-14 a year. Since the main source of representatives of the genus Salmonella are for human food products, there is need to control livestock products against this microorganism. The article presents the data for the 2012-2104 biennium., сharacterizing the degree of reduction of microbial contamination of food representatives p. Salmonella, because in 2012 it was 9.5% in 2013. - 1.3%, in 2014 - 1.0%. The results showed that the samples of poultry meat and meat products were characterized by a high level of detection of bacteria p. Salmonella. The study of animal products serovariantami district were identified Salmonella Group B, C and D.