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Foods (Basel, Switzerland) Dec 2023Cold-smoked salmon are ready-to-eat products that may support the growth of pathogenic during their long shelf-life. Consumption of such contaminated products can cause...
Cold-smoked salmon are ready-to-eat products that may support the growth of pathogenic during their long shelf-life. Consumption of such contaminated products can cause fatal listeriosis infections. Another challenge and potential risk associated with CS salmon is their high levels of sodium salt. Excess dietary intake is associated with serious health complications. In the present study, anti-listerial bacteriocin (nisin), P100 bacteriophages (Phageguard L, PGL) and fermentates (Verdad N6, P-NDV) were evaluated as commercial bio-preservation strategies for increased control of in standard (with NaCl) and sodium-reduced (NaCl partially replaced with KCl) CS salmon. Treatments of CS salmon with nisin (1 ppm) and PGL (5 × 10 pfu/cm) separately yielded significant initial reductions in (up to 0.7 log) compared to untreated samples. Enhanced additive reductions were achieved through the combined treatments of nisin and PGL. Fermentates in the CS salmon inhibited the growth of Listeria but did not lead to its eradication. The lowest levels of during storage were observed in nisin- and PGL-treated CS salmon containing preservative fermentates and stored at 4 °C, while enhanced growth was observed during storage at an abusive temperature of 8 °C. Evaluation of industry-processed standard and sodium-replaced CS salmon confirmed significant effects with up to 1.7 log reductions in levels after 34 days of storage of PGL- and nisin-treated CS salmon-containing fermentates. No differences in total aerobic plate counts were observed between treated (PGL and nisin) or non-treated standard and sodium-reduced CS salmon at the end of storage. The microbiota was dominated by but with a shift showing dominance of spp. and spp. in fermentate-containing samples. Similar and robust reductions in can be achieved in both standard and sodium-replaced CS salmon using the bio-preservation strategies of nisin, PGL and fermentates under various and relevant processing and storage conditions.
PubMed: 38137194
DOI: 10.3390/foods12244391 -
Pesticide Biochemistry and Physiology Dec 2023Spinetoram wax-based bait station (SWBB) is a maintenance-free, long-lasting, and eco-friendly management measure for Bactrocera dorsalis. However, the impacts of...
Spinetoram wax-based bait station (SWBB) is a maintenance-free, long-lasting, and eco-friendly management measure for Bactrocera dorsalis. However, the impacts of low-concentration spinetoram on B. dorsalis have not yet been determined. Therefore, our study aimed to determine the impacts of low-concentration SWBBs on the biology, demographics, detoxifying enzymes, and gut microorganisms of B. dorsalis. Our results showed that low-concentration SWBBs posed dose-dependent effects on the lifespan and fecundity of B. dorsalis adults. Both the LC and LC treatments significantly reduced the fecundity, while only the latter led to significant deleterious effects on the longevity of adults. Transgenerational bioassays revealed that exposure to LC significantly affected the development period of larvae and pupae as well as the livability of pre-adult stage of the progeny. However, except for the ovipositional period, no significant effects on the biological traits of F adults were observed. In terms of the F demographic parameters, dose-dependent effects were observed. Moreover, both the LC and LC treatments significantly extended the mean generation time, while the latter remarkably decreased the finite and intrinsic rates. Additionally, the significant induction of CarE activity by the LC and LC treatment was maintained until 24 and 48 h respectively. The CYP450 O-deethylation activity in the LC treatment was significantly enhanced at 24 and 48 h intervals when compared to the control. Regarding the intestinal bacterial community, after B. dorsalis adults were exposed to low-concentration SWBBs, the relative abundances of Providencia and Vagococcus were significantly increased, whereas those of Lactococcus and Brachyspira experienced a significant decrease. The obtained results are expected to serve as a foundation for the application of spinetoram in "lure-and-kill" strategies against B. dorsalis.
Topics: Animals; Tephritidae; Macrolides; Fertility
PubMed: 38072558
DOI: 10.1016/j.pestbp.2023.105705 -
Journal of the Science of Food and... Mar 2024Aquatic products are rich in nutrients and unique in flavor, and are popular among the public. However, aquatic products are extremely susceptible to quality degradation... (Review)
Review
Analysis of changes in volatile compounds and evolution in free fatty acids, free amino acids, nucleotides, and microbial diversity in tilapia (Oreochromis mossambicus) fillets during cold storage.
BACKGROUND
Aquatic products are rich in nutrients and unique in flavor, and are popular among the public. However, aquatic products are extremely susceptible to quality degradation during storage, of which odor deterioration is the most obvious and influential aspect. Odor deterioration in aquatic products is widespread and severely affects overall flavor and quality. In this study, odor deterioration and flavor-related quality degradation of tilapia during cold storage are discussed, focusing on the changes in volatile compounds and the evolution of free fatty acids (FFAs), free amino acids (FAAs), nucleotides, and microbial diversity.
RESULTS
A total of 63 volatile compounds were detected by gas chromatography-mass spectrometry, including 11 hydrocarbons, 10 alcohols, 6 aldehydes, 8 ketones, 6 esters, 9 aromatics, 3 phenols, and 10 other compounds. Microbial diversity analysis revealed that Acinetobacter, Psychrobacter, Vagococcus, and Myroides were the main dominant species of tilapia at the end of cold storage and predicted that microorganisms could influence the flavor of tilapia by participating in important metabolic pathways. Meanwhile, the evolution of FFAs, FAAs, and nucleotides also had a significant impact on odor deterioration, as evidenced by the contribution of unsaturated fatty acids (such as oleic acid and linoleic acid), Lys, and off-flavor nucleotides (HxR and Hx) to the undesirable flavor. Oxidation of oleic acid and linoleic acid resulted in changes in aldehydes, with Lys, HxR, and Hx being key flavor precursors and off-flavor contributors.
CONCLUSION
This study contributes to a comprehensive overview of odor deterioration and the evolution of flavor-related quality in tilapia during cold storage, providing new insights into the regulation of overall flavor and quality. © 2023 Society of Chemical Industry.
Topics: Animals; Food Storage; Fatty Acids, Nonesterified; Amino Acids; Tilapia; Aldehydes; Linoleic Acids; Oleic Acids; Volatile Organic Compounds
PubMed: 38050785
DOI: 10.1002/jsfa.13188 -
Microorganisms Nov 2023Microbial communities can undergo significant successional changes during decay and decomposition, potentially providing valuable insights for determining the postmortem...
Microbial communities can undergo significant successional changes during decay and decomposition, potentially providing valuable insights for determining the postmortem interval (PMI). The microbiota produce various gases that cause cadaver bloating, and rupture releases nutrient-rich bodily fluids into the environment, altering the soil microbiota around the carcasses. In this study, we aimed to investigate the underlying principles governing the succession of microbial communities during the decomposition of pig carcasses and the soil beneath the carcasses. At early decay, the phylum and were the most abundant in both the winter and summer pig rectum. However, became the most abundant in the winter pig rectum in late decay. Using genus as a biomarker to estimate the PMI could get the MAE from 1.375 days to 2.478 days based on the RF model. The abundance of bacterial communities showed a decreasing trend with prolonged decomposition time. There were statistically significant differences in microbial diversity in the two periods (pre-rupture and post-rupture) of the four groups (WPG 0-8Dvs. WPG 16-40D, < 0.0001; WPS 0-16Dvs. WPS 24-40D, = 0.003; SPG 0D vs. SPG 8-40D, = 0.0005; and SPS 0D vs. SPS 8-40D, = 0.0208). Most of the biomarkers in the pre-rupture period belong to obligate anaerobes. In contrast, the biomarkers in the post-rupture period belong to aerobic bacteria. Furthermore, the genus shows a similar increase trend, whether in winter or summer. Together, these results suggest that microbial succession was predictable and can be developed into a forensic tool for estimating the PMI.
PubMed: 38004822
DOI: 10.3390/microorganisms11112811 -
Environmental Microbiome Nov 2023Beetles are ubiquitous cave invertebrates worldwide that adapted to scarce subterranean resources when they colonized caves. Here, we investigated the potential role of...
Beetles are ubiquitous cave invertebrates worldwide that adapted to scarce subterranean resources when they colonized caves. Here, we investigated the potential role of gut microbiota in the adaptation of beetles to caves from different climatic regions of the Carpathians. The beetles' microbiota was host-specific, reflecting phylogenetic and nutritional adaptation. The microbial community structure further resolved conspecific beetles by caves suggesting microbiota-host coevolution and influences by local environmental factors. The detritivore species hosted a variety of bacteria known to decompose and ferment organic matter, suggesting turnover and host cooperative digestion of the sedimentary microbiota and allochthonous-derived nutrients. The cave Carabidae, with strong mandibula, adapted to predation and scavenging of animal and plant remains, had distinct microbiota dominated by symbiotic lineages Spiroplasma or Wolbachia. All beetles had relatively high levels of fermentative Carnobacterium and Vagococcus involved in lipid accumulation and a reduction of metabolic activity, and both features characterize adaptation to caves.
PubMed: 37957741
DOI: 10.1186/s40793-023-00537-2 -
BMC Infectious Diseases Oct 2023Chronic cholecystitis, characterized by persistent inflammation of the gallbladder, predominantly stems from the prolonged presence of gallstones. Calculous...
BACKGROUND
Chronic cholecystitis, characterized by persistent inflammation of the gallbladder, predominantly stems from the prolonged presence of gallstones. Calculous cholecystitis has demonstrated a consistent escalation in its incidence over time.Gallbladder stones have been recognized as a predisposing factor for the development of biliary tract infections.Concomitantly, there have been substantial shifts in the distribution and resistance profiles of pathogenic microorganisms responsible for biliary tract infections. The timely acquisition of bile samples for pathogen analysis is of paramount importance, given its critical role in guiding judicious clinical pharmacotherapy and enhancing patient prognosis.
CASE PRESENTATION
We present a case involving a 66-year-old female patient who had previously undergone subtotal gastrectomy due to diffuse large B-cell lymphoma. The patient was admitted to our institution with complaints of abdominal pain. Subsequent diagnostic evaluation revealed concurrent choledocholithiasis and cholecystolithiasis. The patient underwent surgical cholecystectomy as the therapeutic approach. Histopathological examination of the excised gallbladder disclosed characteristic features indicative of chronic cholecystitis. Subsequent laboratory analysis of the patient's bile specimen yielded Gram-positive cocci, subsequently identified through biochemical assays, mass spectrometry, and 16 S rRNA analysis as Vagococcus fluvialis. Further in vitro antimicrobial susceptibility testing using disk diffusion and microfluidic dilution showed that this strain exhibited inhibition zone diameters ranging from 12.0 to 32.0 mm in response to 26 antibiotics, including ampicillin, cefazolin, cefuroxime, cefotaxime, ceftriaxone, cefepime, ampicillin/sulbactam, piperacillin, ciprofloxacin, cefoperazone/sulbactam, imipenem, meropenem, piperacillin/tazobarb, penicillin, erythromycin, chloramphenicol, vancomycin, methotrexate/sulfamethoxazole, teicoplanin, linezolid, tigecycline, cefoxitin, ceftazidime, levofloxacin, minocycline and tobramycin. However, the inhibition zone diameters were 6.0 mm for amikacin, oxacillin, clindamycin, and tetracycline. The patient received ceftazidime anti-infective therapy both preoperatively and within 24 h postoperatively and was discharged successfully one week after surgery.
CONCLUSION
In this study, we present the inaugural isolation and identification of Vagococcus fluvialis from bile specimens of patients afflicted with calculous cholecystitis. This novel finding lays a substantial experimental groundwork for guiding clinically rational antimicrobial therapy and advancing the exploration of relevant pathogenic mechanisms pertaining to Vagococcus fluvialis infections.
Topics: Female; Humans; Aged; Ceftazidime; Sulbactam; Bile; Drug Resistance, Bacterial; Microbial Sensitivity Tests; Anti-Bacterial Agents; Anti-Infective Agents; Gram-Positive Cocci; Ampicillin; Piperacillin; Cholecystitis
PubMed: 37845605
DOI: 10.1186/s12879-023-08696-w -
Microbial Pathogenesis Nov 2023In aquaculture, probiotic yeasts have gained particular interest because of their numerous health benefits for farmed fish. Many autochthonous yeasts have been isolated...
Identification of four autochthonous yeasts from the intestines of goldfish, Carassius auratus with potential probiotic properties and their effects on the most common fish bacterial pathogens.
In aquaculture, probiotic yeasts have gained particular interest because of their numerous health benefits for farmed fish. Many autochthonous yeasts have been isolated and identified from fish species with potential probiotic characteristics. In the present study, four autochthonous yeast strains were identified and characterized from the intestinal tracts of 16 healthy goldfish, Carassius auratus. Their in vitro probiotic properties were examined in terms of cell surface hydrophobicity, co-aggregation, and tolerability to different pH values and bile salt concentrations. These strains were identified by culture characters and sequence analysis of ITS (Internal Transcribed Spacer) gene regions. Four strains, namely Cutaneotrichosporon jirovecii isolate jpn01, Debaryomyces nepalensis isolate jpn02, Blastobotrys proliferans isolate jpn05, and Diutina catenulata isolate jpn06, were identified and added to the NCBI GenBank with accession numbers defined as MT584874.1, MT584873.1, MT649918.1, and MT501155.1, respectively. Results demonstrated the capability of these strains to co-aggregate with several fish-associated bacterial pathogens such as Lactococcus garvieae, Vagococcus salmoninarum, Vibrio anguillarum, Yersinia ruckeri, and Aeromonas hydrophila. Only the jpn05 strain did not co-aggregate with A. hydrophila. All identified yeast isolates could grow and tolerate low pH conditions (pH 2.0) and bile salt concentrations (up to 1.5%). Of interest, the hydrophobicity (%) of the yeast isolates was 80%, 94.0%, 80.6%, and 66.4% for jpn01, jpn02, jpn05, and jpn06 isolates, respectively. In this context, our data provide important in vitro evidence for the potential probiotic features of the yeast isolates. These strains could be considered candidate probiotic yeasts; however, their application in aquaculture nutrition necessitates further in vivo assays.
Topics: Animals; Goldfish; Saccharomyces cerevisiae; Probiotics; Bacteria; Intestines; Bile Acids and Salts; Fish Diseases
PubMed: 37806502
DOI: 10.1016/j.micpath.2023.106381 -
Food Research International (Ottawa,... Oct 2023Fermented fish and fermented fish-based products are part of the diet of many countries all over the world. Their popularity is not only due to the unique flavor, the... (Review)
Review
Fermented fish and fermented fish-based products are part of the diet of many countries all over the world. Their popularity is not only due to the unique flavor, the distinct texture, and the good nutritional quality, but also to the easiness of the production process, that is commonly based on empirical traditional methods. Fish fermentation techniques ususally rely on the combination of some key steps, including salting, addition of spices or additives, and maintenance of anaerobic conditions, thus selecting for the multiplication of some pro-technological microorganisms. The objective of the present review was to provide an overview of the current knowledge of the microbial communities occurring in fermented fish and fish-based products. Specific information was collected from scientific publications published from 2000 to 2022 with the aim of generating a comprehensive database. The production of fermented fish and fish-based foods was mostly localized in West African countries, Northern European countries, and Southeast Asian countries. Based on the available literature, the microbial composition of fermented fish and fish-based products was delineated by using viable counting combined with identification of isolates, and culture-independent techniques. The data obtained from viable counting highlighted the occurrence of microbial groups usually associated with food fermentation, namely lactic acid bacteria, staphylococci, Bacillus spp., and yeasts. The identification of isolates combined with culture-independent methods showed that the fermentative process of fish-based products was generally guided by lactobacilli (Lactiplantibacillus plantarum, Latilactobacillus sakei, and Latilactobacillus curvatus) or Tetragenococcus spp. depending on the salt concentration. Among lactic acid bacteria populations, Lactococcus spp., Pediococcus spp., Leuconostoc spp., Weissella spp., Enterococcus spp., Streptococcus spp., and Vagococcus spp. were frequently identified. Staphylococcus spp. and Bacillus spp. confirmed a great adaptation to fermented fish-based products. Other noteworthy bacterial taxa included Micrococcus spp., Pseudomonas spp., Psychrobacter spp., Halanaerobium spp., and Halomonas spp. Among human pathogenic bacteria, the occurrence of Clostridium spp. and Vibrio spp. was documented. As for yeast populations, the predominance of Candida spp., Debaryomyces spp., and Saccharomyces spp. was evidenced. The present literature review could serve as comprehensive database for the scientific community, and as a reference for the food industry in order to formulate tailored starter or adjunctive cultures for product improvement.
Topics: Animals; Humans; Acclimatization; Africa, Western; Bacillus; Candida; Databases, Factual; Enterococcaceae; Fishes
PubMed: 37689879
DOI: 10.1016/j.foodres.2023.113112 -
Microorganisms Jul 2023A large variety of cheeses can be produced using different manufacturing processes and various starter or adjunct cultures. In this study, we have described the...
A large variety of cheeses can be produced using different manufacturing processes and various starter or adjunct cultures. In this study, we have described the succession of the microbial population during the commercial production and subsequent ripening of smear-ripened cheese using 16S rRNA gene sequencing. The composition of the microbiota during the first 6 days of production was constant and consisted mainly of LAB (lactic acid bacteria) originating from the starter culture. From day 7, the proportion of LAB decreased as other bacteria from the production environment appeared. From the 14th day of production, the relative proportion of LAB decreased further, and at the end of ripening, bacteria from the environment wholly dominated. These adventitious microbiota included , /, , and (Proteobacteria phylum), as well as and (Firmicutes phylum), (Fusobacteria phylum), and (Campylobacterota phylum), all of which appeared to be characteristic taxa associated with the cheese rind. Subsequent analysis showed that the production and ripening of smear-ripened cheese could be divided into three stages, and that the microbiota compositions of samples from the first week of production, the second week of production, and supermarket shelf life all differed.
PubMed: 37512907
DOI: 10.3390/microorganisms11071735 -
Toxics Jul 2023Black soldier fly () larvae (BSFL) possess remarkable antibiotic degradation abilities due to their robust intestinal microbiota. However, the response mechanism of BSFL...
Comparative Metagenomic and Metatranscriptomic Analyses Reveal the Response of Black Soldier Fly () Larvae Intestinal Microbes and Reduction Mechanisms to High Concentrations of Tetracycline.
Black soldier fly () larvae (BSFL) possess remarkable antibiotic degradation abilities due to their robust intestinal microbiota. However, the response mechanism of BSFL intestinal microbes to the high concentration of antibiotic stress remains unclear. In this study, we investigated the shift in BSFL gut microbiome and the functional genes that respond to 1250 mg/kg of tetracycline via metagenomic and metatranscriptomic analysis, respectively. The bio-physiological phenotypes showed that the survival rate of BSFL was not affected by tetracycline, while the biomass and substrate consumption of BSFL was slightly reduced. Natural BSFL achieved a 20% higher tetracycline degradation rate than the germ-free BSFL after 8 days of rearing. Metagenomic and metatranscriptomic sequencing results revealed the differences between the entire and active microbiome. Metatranscriptomic analysis indicated that , , , and were the active genera that responded to tetracycline. Furthermore, based on the active functional genes that responded to tetracycline pressure, the response mechanisms of BSFL intestinal microbes were speculated as follows: the family that mediates the expression of efflux pumps expel tetracycline out of the microbes, while and release it from the ribosome. Eventually, tetracycline was degraded by deacetylases and novel enzymes. Overall, this study provides novel insights about the active intestinal microbes and their functional genes in insects responding to the high concentration of antibiotics.
PubMed: 37505576
DOI: 10.3390/toxics11070611