Occurrence of mycotoxins in talkan: a cereal-based food traditional for Turkic population.

The consumption of cereal contaminated with mycotoxins poses a serious health risk for humans and animals. The present work aims to evaluate the presence of mycotoxins in talkan, a cereal-based food commonly consumed by the Turkic population. The presence of mycotoxins was investigated in a total of 50 samples obtained from Kazakhstan. After a preliminary screening using various ELISA kits, mycotoxins were confirmed and quantified by HPLC-MS/MS method. More than 28% of the samples were positive for at least one mycotoxin. The calculated probably daily intake for adults and children was 20% above the tolerable daily intake for aflatoxin B1 and deoxynivalenol, while it was above 100% for zearalenone, indicating a high risk for the Kazakh population. A total of 12 samples exhibited concentrations above the European maximum level for ochratoxin A, zearalenone and deoxynivalenol, however, these values were within the limits established by the Russia-Kazakhstan-Belarus Customs Union (TR CU 015/2011).

Assessment of food safety using a new real-time PCR assay for detection and quantification of virulence factors of enterococci in food samples.

AIMS: Development of Taqman MGB real-time PCR (q-PCR) assays for the quantitative detection of virulence factor genes in pure culture and food samples with regard to food safety assessment. METHODS AND RESULTS: New Taqman primers and probes were designed for the ace, esp and gelE genes based on the determinants of virulence profiles of enterococcal strains from GenBank. The high specificity and accuracy of the Taqman probe assay was confirmed. The limit of detection for the different virulence genes was 102  CFU ml-1 or CFU g-1 for pure culture and meat samples, and 103  CFU g-1 for cheese samples. CONCLUSION: This method provides the specific and rapid detection and quantification of ace, esp and gelE genes compared to conventional PCR assays, thus allowing the rapid and direct safety assessment of Enterococcus genus in food samples. SIGNIFICANCE AND IMPACT OF THE STUDY: This study presents efficient methods that can be used directly on food products for the rapid quantification and tracing of virulence genes, regarding food safety assessment. Moreover, this is the first study to quantify these virulence factors using a specific Taqman q-PCR assay in food samples.

Development of a real-time PCR assay for direct detection and quantification of Bacillus sporothermodurans in ultra-high temperature milk.

In our study, a new and highly sensitive real-time PCR Taqman assay was developed for the direct and specific detection of Bacillus sporothermodurans in UHT milk. The target region was selected based on the 16S rRNA gene profiles of 11 B. sporothermodurans from GenBank. A standard curve was created using a reference strain of B. sporothermodurans, DSM 10599. A low limit of detection for B. sporothermodurans in UHT milk (10 cfu/mL) was obtained. Furthermore, a total of 110 UHT milk samples from several supermarkets were directly assessed to detect and quantify B. sporothermodurans using the real-time PCR Taqman developed. The B. sporothermodurans counts obtained were highly correlated with the microbial plate counts in the UHT milk samples. This is the first time that B. sporothermodurans has been quantified directly from UHT milk. This technique could be applicable as a routine tool for preventing the growth of these bacteria by allowing for the rapid screening of raw milk samples in dairy plants. As expected, the probability of bacterial growth in UHT milk packages increased with the B. sporothermodurans counts in the raw milk.

A study on toxic and essential elements in rice from the Republic of Kazakhstan: comparing the level of contamination in rice from the European Community.

Selected toxic elements (total As, Cd, Cr, Hg, Pb, Sr, U and V) and essential elements (Co, Cu, Fe, Mn and Zn) were analyzed using an inductively coupled plasma mass spectrometry (ICP-MS) in unpolished and milled rice collected from Kazakhstan and milled rice from Spain and Portugal to evaluate the potential health risk to the population. Arsenic species (arsenite, arsenate, arsenobetaine, dimethylarsinate and monomethilarsonate) were analyzed using HPLC-IC-MS. From 146 samples analyzed, none of them exceeded the maximum limit set by the European Legislation for Cd or Pb or values recommended by the Codex Alimentarius. Concentrations of Sr, U and V were below LOD and those of Hg, Pb, Co and Cr between

What Is Your Diagnosis?

In collaboration with the American College of Veterinary Radiology.

[Mild encephalitis/encephalopathy with a reversible splenial corpus callosum lesion (MERS)]. / Encefalitis/encefalopatía leve con lesión reversible del esplenio del cuerpo calloso (MERS).

INTRODUCTION: Mild encephalitis/encephalopathy with a reversible isolated splenial corpus callosum lesion (MERS) is a clinical-radiological syndrome characterized by a lesion in the center of the splenium identified by magnetic resonance imaging (MRI), the imaging test of choice. CASE REPORT: A 31-year-old man is admitted with fever, intense hemicranial headache, disorientation, dysarthria and paresthesia in the lips and both upper extremities is presented; and that he is admitted for a suspected diagnosis of viral encephalitis. The cerebrospinal fluid analysis shows an elevation of proteins and the electroencephalogram shows generalized slowing, predominantly on the left. MRI shows a well-defined ovoid lesion, isolated in the splenium of the corpus callosum, homogeneous and hyperintense on T2 and FLAIR, with restriction to fluid diffusion and without uptake after gadolinium administration. The patient received empirical treatment with acyclovir and corticosteroids, with good subsequent evolution and disappearance of the lesion described in the control MRI at 3 weeks. CONCLUSION: MERS is a benign, infrequent entity of unknown pathogenesis, which must be differentiated from other pathologies that present with lesions of the corpus callosum, but with an unfavorable prognosis.

TITLE: Encefalitis/encefalopatía leve con lesión reversible del esplenio del cuerpo calloso (MERS).Introducción. La encefalitis/encefalopatía leve con lesión reversible aislada del esplenio del cuerpo calloso (MERS) es un síndrome clinicorradiológico caracterizado por una lesión en el centro del esplenio identificada por resonancia magnética, prueba de imagen de elección. Caso clínico. Se presenta el caso de un varón de 31 años con cuadro de fiebre, cefalea intensa hemicraneal, desorientación, disartria y parestesias en los labios y en ambas extremidades superiores, y que ingresa por sospecha diagnóstica de encefalitis vírica. El análisis del líquido cefalorraquídeo muestra una elevación de proteínas y el electroencefalograma manifiesta una lentificación generalizada de predominio izquierdo. La resonancia magnética evidencia una lesión ovoidea, bien delimitada, aislada en el esplenio del cuerpo calloso, homogénea e hiperintensa en T2 y FLAIR, con restricción a la difusión hídrica y sin captación tras la administración de gadolinio. El paciente recibe tratamiento de forma empírica con aciclovir y corticoesteroides, con buena evolución posterior y desaparición de la lesión descrita en la resonancia magnética de control a las tres semanas. Conclusión. La MERS es una entidad benigna, infrecuente y de patogenia desconocida, que debe diferenciarse de otras patologías que cursan con lesiones del cuerpo calloso en las que el pronóstico es desfavorable.

Differentiation of farmed and wild turbot (Psetta maxima): proximate chemical composition, fatty acid profile, trace minerals and antimicrobial resistance of contaminant bacteria.

The proximate, cholesterol, fatty acid and trace mineral compositions in the flesh of farmed and wild turbot (Psetta maxima) were evaluated. Additionally, the potential influence of the use of antimicrobial agents in the bacteria carried by farmed turbot was investigated. For this purpose, a total of 144 Pseudomonas spp. and 127 Aeromonas spp. were isolated and tested for their susceptibility to 12 antimicrobials by a disk diffusion method. Farmed turbot contained higher fat, cholesterol and calories as well as lower moisture content than its wild counterpart. The fatty acid profile of farmed turbot included higher levels of myristic, pentadecanoic, palmitoleic, gadoleic, cetoleic, linoleic, linolenic, stearidonic, eicosadienoic and eicosapentaenoic acids, and lower levels of stearic, arachidonic, docosapentaenoic and docosahexaenoic acids than its wild counterpart. The proportions of polyunsaturated fatty acids and n-3/n-6 ratios were higher in wild turbot than in farmed turbot. With respect to trace minerals, no toxic levels were found, and higher amounts of Cd, Co, Cu, Fe, Mn, Pb and Zn, as well as lower amounts of Cr, were found in farmed turbot relative to wild turbot. The antimicrobial resistance of Pseudomonas spp. and Aeromonas spp. were quite similar, with only the trimethoprim-sulfamethoxazole resistance of Aeromonas spp. isolated from farmed turbot being higher than those isolated from wild turbot. In the case of ampicillin, Pseudomonas spp. isolated from wild turbot showed higher resistance levels than those of their counterparts isolated from farmed turbot. In conclusion, the nutritional parameters of wild turbot are more adequate with respect to nutritional recommendations, while no differences were observed in food safety derived from trace mineral concentrations or the antimicrobial resistance of bacteria isolated from wild and farmed turbot.

Plasmodium carmelinoi n. sp. (Haemosporida: Plasmodiidae) of the lizard Ameiva ameiva (Squamata: Teiidae) in Amazonian Brazil.

Plasmodium carmelinoi n. sp. is described in the teiid lizard Ameiva ameiva from north Brazil. Following entry of the merozoites into the erythrocyte, the young, uninucleated trophozoites are at first tear-shaped and already possess a large vacuole: with growth, they may assume an irregular shape, but eventually become spherical or broadly ovoid. The vacuole reduces the cytoplasm of the parasite to a narrow peripheral band in which nuclear division produces a schizont with 8-12 nuclei. At first the dark, brownish-black pigment granules are restricted to this rim of cytoplasm but latterly become conspicuously concentrated within the vacuole. The mature schizonts are spherical to ovoid and predominantly polar in their position in the erythrocyte. They average 5.4 x 4,9 microm (4.4 x 4.4 - 6.6 x 5,9 microm), shape index 1.1, n = 50: 8-12 merozoites are produced and measure approximately 2.0 x 1,0 microm. Mature gametocytes are also polar in position, and spherical to subspherical. The macrogametocytes measure 5.7 x 5,2 microm (4.4 x 4.0- 5.9 x 5,1 microm), shape index 1.1, n = 50 and, following staining by Giemsa's method, possess a compact, pink-staining nucleus and a clear blue, faintly stained cytoplasm. Microgametocytes are slightly larger, 6.0 x 5,0 microm (5.2 x 4.4 - 6.2 x 5,2 microm), shape index 1.2, n = 45. They stain an over-all pink colour due to the dispersed nuclear chromatin. The vacuoles in both the macro- and microgametocytes are considerably smaller than those of the schizonts and of ovoid or spindle shape: they contain most of the pigment granules. The sex ratio, as seen in an inicial intense infection, was 1 male to 2.2 females. Prevalence of infection was low (5%) but, due to the very low parasitaemia which may result in a failure to detect parasites, it is probably higher than this.

Influence of farming methods on microbiological contamination and prevalence of resistance to antimicrobial drugs in isolates from beef.

The presence of Escherichia coli, Staphylococcus aureus, Listeria monocytogenes and Salmonella spp. was determined in 75 samples of conventional beef and in 75 samples of organic beef. All samples came from cattle slaughtered and processed in the same slaughterhouse and quartering room. A total of 180 E. coli, 180 S. aureus and 98 L. monocytogenes strains were analyzed by an agar disk diffusion assay for their resistance to 11 antimicrobials, for the case of E. coli and S. aureus, or 9 antimicrobials, for the case of L. monocytogenes. Salmonella spp. were not isolated from any of the beef samples. No significant differences in prevalence were obtained for any of the bacterial species tested between organic and conventional beef. E. coli isolated from organic beef exhibited significant differences in antimicrobial resistance against 5 of the 11 antimicrobials tested as compared to isolates recovered from conventional beef. In the case of S. aureus, these differences were only found for 3 of the 11 antimicrobials tested and for L. monocytogenes, no differences were obtained between isolates obtained from organic or conventional beef. Although no significant differences were obtained in microbiological contamination, E. coli and S. aureus isolates from organically farmed beef samples showed significantly lower rates of antimicrobial resistance in E. coli and S. aureus isolates.

Endophytic actinobacteria induce defense pathways in Arabidopsis thaliana.

Endophytic actinobacteria, isolated from healthy wheat tissue, which are capable of suppressing a number wheat fungal pathogens both in vitro and in planta, were investigated for the ability to activate key genes in the systemic acquired resistance (SAR) or the jasmonate/ethylene (JA/ET) pathways in Arabidopsis thaliana. Inoculation of A. thaliana (Col-0) with selected endophytic strains induced a low level of SAR and JA/ET gene expression, measured using quantitative polymerase chain reaction. Upon pathogen challenge, endophyte-treated plants demonstrated a higher abundance of defense gene expression compared with the non-endophyte-treated controls. Resistance to the bacterial pathogen Erwinia carotovora subsp. carotovora required the JA/ET pathway. On the other hand, resistance to the fungal pathogen Fusarium oxysporum involved primarily the SAR pathway. The endophytic actinobacteria appear to be able to "prime" both the SAR and JA/ET pathways, upregulating genes in either pathway depending on the infecting pathogen. Culture filtrates of the endophytic actinobacteria were investigated for the ability to also activate defense pathways. The culture filtrate of Micromonospora sp. strain EN43 grown in a minimal medium resulted in the induction of the SAR pathway; however, when grown in a complex medium, the JA/ET pathway was activated. Further analysis using Streptomyces sp. strain EN27 and defense-compromised mutants of A. thaliana indicated that resistance to E. carotovora subsp. carotovora occurred via an NPR1-independent pathway and required salicylic acid whereas the JA/ET signaling molecules were not essential. In contrast, resistance to F. oxysporum mediated by Streptomyces sp. strain EN27 occurred via an NPR1-dependent pathway but also required salicylic acid and was JA/ET independent.

Comparison of antimicrobial resistance in Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes strains isolated from organic and conventional poultry meat.

The presence of Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes was determined in 55 samples of organic poultry meat and in 61 samples of conventional poultry meat. A total of 220 E. coli, 192 S. aureus, and 71 L. monocytogenes strains were analyzed by an agar disk diffusion assay for their resistance to ampicillin, cephalothin, chloramphenicol, ciprofloxacin, doxycycline, fosfomycin, gentamicin, nitrofurantoin, streptomycin, and sulfisoxazole (E. coli); chloramphenicol, ciprofloxacin, clindamycin, doxycycline, erythromycin, gentamicin, nitrofurantoin, oxacillin, and sulfisoxazole (S. aureus); and chloramphenicol, doxycycline, erythromycin, gentamicin, sulfisoxazole, and vancomycin (L. monocytogenes). The results indicated a significantly higher (P < 0.0001) prevalence of E. coli but not of S. aureus and L. monocytogenes in organic poultry meat as compared with conventional poultry meat. E. coli isolated from organic poultry meat exhibited lower levels of antimicrobial resistance against 7 of the 10 antimicrobials tested as compared with isolates recovered from conventional meat. In the case of S. aureus and L. monocytogenes isolated from conventional poultry, antimicrobial resistance was significantly higher only for doxycycline as compared with strains isolated from organic poultry. In the case of E. coli, the presence of multiresistant strains was significantly higher (P < 0.0001) in conventional poultry meat as compared with organic poultry meat. Organically farmed poultry samples showed significantly lower development of antimicrobial resistance in intestinal bacteria such as E. coli.

Evolution of resistance in poultry intestinal Escherichia coli during three commonly used antimicrobial therapeutic treatments in poultry.

The resistance rates of intestinal Escherichia coli populations from poultry were determined during treatment and withdrawal period with 3 antimicrobial agents commonly used as therapeutics in poultry medicine. A total of 108 chickens were considered: 18 were treated orally with enrofloxacin, 18 with doxycycline, and 18 with sulfonamides, whereas another 18 chickens were maintained as controls for each antimicrobial group. Fecal samples were taken during the treatment and after the withdrawal period, and E. coli were isolated through Fluorocult media plating. A total of 648 E. coli strains (216 per antimicrobial tested) were isolated and identified though biochemical methods. Minimal inhibitory concentrations to the antimicrobials used were also determined using a broth microdilution method. The resistance rates of intestinal E. coli to all of the antimicrobials tested significantly increased during the course of the therapeutic treatment. In addition, significant differences (P = 0.0136) in resistance rates persisted between the intestinal E. coli of the enrofloxacin-treated and control batches until the end of the withdrawal period, but this difference was not observed for the cases of doxycycline or sulfonamides treatments. Antimicrobial use in poultry medicine seems to select for antimicrobial-resistant strains of pathogenic bacterial species such as E. coli. In some cases, the higher frequencies of resistant strains may persist in the avian intestinal tract until the end of the withdrawal period, when it is legal to use these animals for human consumption.

Trypanosoma (Megatrypanum) saloboense n. sp. (Kinetoplastida: Trypanosomatidae) parasite of Monodelphis emiliae (Marsupiala: Didelphidae) from Amazonian Brazil.

Trypanosoma (Megatrypanum) soloboense n. sp., is described in the Brazilian opossum Monodelphis emiliae (Thomas, 1912) from primary forest in the Salobo area of the Serra dos Carajás (6 degrees S, 50 degrees 18' W) Pará State, North Brazil. Two morphologically different trypomastigotes were noted. Slender forms, regarded as immature parasites, have a poorly developed undulating membrane adhering closely to the body: large, broad forms with a well developed membrane are considered to be the mature trypomastigotes and have a mean total length of 71.2 microm (62.4-76.2) and a width of 6.1 (5.0-8.0). Infections studied in two opossums were of very low parasitaemia. The large size of T. (M.) saloboense readily distinguishes it from the two previously described members of the subgenus Megatrypanum of neotropical marsupials, T. (M.) freitasi Régo et al., 1957 of Didelphis ozarae and D. marsupialis, and T. (M.) samueli Mello, 1977 of Monodelphis domesticus, which measure only 49.0-51.5 microm and 42.4 microm respectively. No infections were obtained in hamsters inoculated with triturated liver and spleen from one infected M. emiliae, or in laboratory mice inoculated with epimastigotes from a blood-agar culture. No division stages could be detected in the internal organs or the peripheral blood.

New species of Eimeria and Isospora (Protozoa: Eimeriidae) in Geochelone spp. (Chelonia: Testudinidae) from Amazonian Brazil.

Tetrasporocystic, dizoic oocysts of reptiles have been separated by some authors into the genera Eimeria, Choleoeimeria and Acroeimeria (Protozoa: Eimeriidae), based on the site and mode of development of their endogenous stages. The majority of Eimeria species have been, and still are, however, described on oocyst morphology alone. Four different oocysts with this basic morphology were encountered in the faeces of Brazilian tortoises, Geochelone carbonaria Spix, 1824 and are assigned to the genus Eimeria, with the view that they can readily be transferred to the genus Choleoeimeria or Acroeimeria if this is indicated by a future examination of their endogenous development. A morphological comparison distinguishes the oocysts from those of Eimeria spp., previously described in chelonids of the family Testudinidae, and the names E. amazonensis, E. carbonaria, E. carajasensis and E. wellcomei n. spp. are proposed. Coccidial infection appears to be common in G. carbonaria, with three of seven animals examined passing oocysts. Oocysts of Isospora rodriguesae n. sp. (Protozoa: Eimeriidae) are described in the faeces of Geochelone denticulata Linnaeus, 1766. They are morphologically very different from those of Isospora testudae, Davronov, 1985 in Testudo horsfieldi. Eimeria motelo Hurková et al., 2000, previously described in Geochelone denticulata from Peru, is here recorded in the some chelonid from Amazonian Brazil.

Study of a room temperature phosphorescence phenomenon to allow the detection of aflatoxigenic strains in culture media.

A novel screening method based on room temperature phosphorescence (RTP) for the visual detection of aflatoxigenic strains from Aspergillus genus is described. Strains were cultured on media widely used in food mycology to which methyl-beta-cyclodextrin plus bile salts (0.6% sodium deoxycholate) were added. Aflatoxin production was readily detectable after 3 days of incubation at 28 degrees C by RTP emission from the mycelium of aflatoxigenic strains observed after exposure to UV light. The method was tested on thirty-two Aspergillus sp. strains. The phosphorescence phenomenon was reproduced in vitro by immobilizing aflatoxin B1 on ion exchange resin beads.

Liquid chromatography-electrospray ionization-mass spectrometry method in multiple reaction monitoring mode to determine 17alpha-ethynylestradiol residues in cattle hair without previous digestion.

A liquid chromatography-mass spectrometric (LC-MS/MS) method has been developed for determination of ethynylestradiol residues in cattle hair. Hair samples were pulverized with a cryogenic mill followed by a simple extraction with acetonitrile. A dansyl derivatization procedure to improve ethynylestradiol detection was used before the LC-MS/MS analysis in multiple reaction monitoring (MRM) mode using alpha-estradiol as an internal standard. The method was validated following the latest EU guidelines using blank hair samples spiked at 2 ng g(-1). The detection capability (CCbeta) was less than 2 ng g(-1), and the decision limit (CCalpha) was 1 ng g(-1). Incurred samples obtained 56 days after cow treatment with ethynylestradiol were analyzed, and the presence of ethynylestradiol in the hair was confirmed in all cases.

Antimicrobial resistance in Enterococcus spp. strains isolated from organic chicken, conventional chicken, and turkey meat: a comparative survey.

The mean counts of Enterococcus spp. were determined for 30 samples each of organic chicken meat, conventional chicken meat, and turkey meat, and differences for Enterococcus contamination in meat were determined. Two enterococci strains from each sample were isolated to obtain a total of 180 strains, and resistance to ampicillin, chloramphenicol, doxycycline, ciprofloxacin, erythromycin, gentamicin, nitrofurantoin, and vancomycin was determined by a disk diffusion method. Average counts obtained showed that Enterococcus mean counts from organic chicken meat (3.18 log CFU/g) were significantly higher than those obtained from conventional chicken meat (2.06 log CFU/g) or conventional turkey meat (1.23 log CFU/g). However, the resistance data obtained showed that isolates from organic chicken meat were less resistant than enterococci isolates from conventional chicken meat to ampicillin (P = 0.0067), chloramphenicol (P = 0.0154), doxycycline (P = 0.0277), ciprofloxacin (P = 0.0024), erythromycin (P = 0.0028), and vancomycin (P = 0.0241). In addition, isolates from organic chicken were less resistant than conventional turkey meat isolates to ciprofloxacin (P = 0.001) and erythromycin (P = 0.0137). Multidrug-resistant isolates were found in every group tested, but rates of multidrug-resistant strains were significantly higher in conventional chicken and turkey than those obtained from organic chicken meat. Enterococcus faecalis was the most common species isolated from organic chicken (36.67%), whereas Enterococcus durans was the most common species isolated from conventional chicken (58.33%) and turkey (56.67%). The rates obtained for antimicrobial resistance suggest that although organic chicken meat may have higher numbers of Enterococcus, these bacteria present a lower level of antimicrobial resistance.

Natural and experimental infection of the lizard Ameiva ameiva with Hemolivia stellata (Adeleina: Haemogregarinidae) of the toad Bufo marinus.

Developmental stages of a haemogregarine in erythrocytes of the lizard Ameiva ameiva (Teiidae), from Pará State, north Brazil, were shown to be those of Hemolivia by the nature of the parasite's sporogonic cycle in the tick Amblyomma rotondatum. The type species, Hemolivia stellata Petit et al., 1990 was described in the giant toad Bufo marinus and the tick Amblyomma rotondatum, also from Pará State, and in view of the fact that A. ameiva and Bufo marinus share the same habitat and are both commonly infested by A. rotondatum, the possibility that the parasite of A. ameiva is H. stellata had to be considered. Uninfected lizards fed with material from infected ticks taken from B. marinus, and others fed with liver of toads containing tissue-cysts of H. stellata, were shown to subsequently develop typical Hemolivia infections, with all stages of the development similar to those seen in the naturally infected lizards. Conversely, a juvenile, uninfected toad became infected when fed with sporocysts of Hemolivia in a macerated tick that had fed on an infected A. ameiva and pieces of liver containing tissuecysts from the same lizard. The remarkable lack of host specificity shown by H. stellata, in hosts so widely separated as an amphibian and a reptile, is discussed.

Phytanic acid consumption and human health, risks, benefits and future trends: A review.

Phytanic acid is a methyl-branched fatty acid present in the human diet, derived from the enzymatic degradation of phytol and subsequently oxidized by the rumenal microbiota and certain marine organisms. Consequently, phytanic acid is carried into the human body by means of food ingestion, mostly via red meat, dairy products and fatty marine foods. This fatty acid accumulates in people with some peroxisomal disorders and is traditionally related to neurological damage. However, some benefits derived from phytanic acid intake have also been described, such as the prevention of metabolic syndrome or type 2 diabetes. The aim of this work was to conduct an overview of the literature on the phytanic acid content of foods, management of the phytanic content during food production and biochemical mechanisms of phytanic acid metabolism, as well as to assess the evidence for the health benefits and risks of phytanic acid consumption in human health.

Biofilm formation, phenotypic production of cellulose and gene expression in Salmonella enterica decrease under anaerobic conditions.

Salmonella enterica subsp. enterica is one of the main food-borne pathogens. This microorganism combines an aerobic life outside the host with an anaerobic life within the host. One of the main concerns related to S. enterica is biofilm formation and cellulose production. In this study, biofilm formation, morphotype, cellulose production and transcription of biofilm and quorum sensing-related genes of 11 S. enterica strains were tested under three different conditions: aerobiosis, microaerobiosis, and anaerobiosis. The results showed an influence of oxygen levels on biofilm production. Biofilm formation was significantly higher (P<0.05) in aerobiosis than in microaerobiosis and anaerobiosis. Cellulose production and RDAR (red, dry, and rough) were expressed only in aerobiosis. In microaerobiosis, the strains expressed the SAW (smooth and white) morphotype, while in anaerobiosis the colonies appeared small and red. The expression of genes involved in cellulose synthesis (csgD and adrA) and quorum sensing (sdiA and luxS) was reduced in microaerobiosis and anaerobiosis in all S. enterica strains tested. This gene expression levels were less reduced in S. Typhimurium and S. Enteritidis compared to the tested serotypes. There was a relationship between the expression of biofilm and quorum sensing-related genes. Thus, the results from this study indicate that biofilm formation and cellulose production are highly influenced by atmospheric conditions. This must be taken into account as contamination with these bacteria can occur during food processing under vacuum or modified atmospheres.