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Current Research in Food Science 2022A microbial starter culture is expected to improve the quality of traditional fermented fish products. was selected for grass carp fermentation due to its high...
Proteomics and metagenomics reveal the relationship between microbial metabolism and protein hydrolysis in dried fermented grass carp using a lactic acid bacteria starter culture.
A microbial starter culture is expected to improve the quality of traditional fermented fish products. was selected for grass carp fermentation due to its high proteolytic activity. To investigate its effects on muscle proteolysis of dried fermented fish, the protein profile and microbial community were analysed by using proteomics and metabolomics. The myofibrillar protein and collagen profiles showed remarkable variation after processing, changes that were related to the development of flavour and texture in fish samples. The starter culture had a marked effect on the microbial composition. and were the dominant genera, with a relative abundance of 24.79% and 12.53%, respectively. There were significant correlations (P < 0.05) between the dominant genera and the major peptidase genes and quality-related proteins. These findings suggest that microbial activity is involved in proteolysis and affects the flavour and texture of dried fermented fish.
PubMed: 36467746
DOI: 10.1016/j.crfs.2022.11.016 -
Frontiers in Microbiology 2021In current study, bacterial diversity and community in different tissues of pork bacon were determined using high-throughput sequencing. In total, six phyla and 111...
In current study, bacterial diversity and community in different tissues of pork bacon were determined using high-throughput sequencing. In total, six phyla and 111 bacterial genera were identified. Among them, three dominant genera (, , and ) were shared by all bacon samples. The linear discriminant analysis showed that 24 bacterial taxa significantly differentiated between the tissues. Results of non-metric Multidimensional Scaling and redundancy analysis showed that physicochemical characteristics of the tissue prominently structured the bacterial communities. Network analysis also illustrated that tissue type was an important factor impacting the bacterial interactions in different types of tissue. The results of current study can add valuable insights to the traditional homemade pork bacon.
PubMed: 34925308
DOI: 10.3389/fmicb.2021.799332 -
PloS One 2021Atopic dermatitis is one of the most common skin diseases in dogs. Pathogenesis is complex and incompletely understood. Skin colonizing bacteria likely play an important...
Atopic dermatitis is one of the most common skin diseases in dogs. Pathogenesis is complex and incompletely understood. Skin colonizing bacteria likely play an important role in the severity of this disease. Studying the canine skin microbiota using traditional microbiological methods has many limitations which can be overcome by molecular procedures. The aim of this study was to describe the bacterial microbiota of the skin and ear canals of healthy non-allergic and allergic German shepherd dogs (GSDs) without acute flare or concurrent skin infection and to compare both. Bacterial 16S rRNA gene amplicon sequence data revealed no differences of bacterial community patterns between the different body sites (axilla, front dorsal interdigital skin, groin, and ear canals) in non-allergic dogs. The microbiota at the different body sites of non-allergic GSDs showed no significant differences. Only for the samples obtained from the axilla the bacterial microbiota of allergic dogs was characterized by a lower species richness compared to that of non-allergic dogs and the bacterial community composition of the skin and ear canals of allergic dogs showed body site specific differences compared to non-allergic dogs. Actinobacteria was the most abundant phylum identified from the non-allergic dogs and Proteobacteria from allergic dogs. Macrococcus spp. were more abundant on non-allergic skin while Sphingomonas spp. were more abundant on the allergic skin. Forward step redundancy analysis of metadata indicated that the household the dogs came from had the strongest impact on the composition of the skin microbiome followed by sex, host health status and body site.
Topics: Animals; Dogs; Ear Canal; Female; High-Throughput Nucleotide Sequencing; Hypersensitivity; Male; Microbiota; Skin
PubMed: 33939741
DOI: 10.1371/journal.pone.0250695 -
Journal of Food Protection Apr 2016The aim of this study was to investigate the phenotypic and genotypic antimicrobial resistance, integrons, and transferability of resistance markers in 243 aerobic...
The aim of this study was to investigate the phenotypic and genotypic antimicrobial resistance, integrons, and transferability of resistance markers in 243 aerobic bacteria recovered from pork at slaughter in the People's Republic of China. The organisms belonged to 22 genera of gram-negative bacteria (92.2%) and gram-positive bacteria (7.8%). High levels of resistance were detected to tetracycline, trimethoprim-sulfamethoxazole, and ampicillin (36.2 to 54.3%), and lower levels were detected to nitrofurantoin, cefotaxime, gentamicin, ciprofloxacin, and chloramphenicol (7.8 to 29.2%). Across species, genes conferring antimicrobial resistance were observed with the following frequencies: blaTEM, 40.7%; blaCMY-2, 15.2%; blaCTX-M, 11.5%; sul2, 27.2%; sul1, 14.4%; tet(A), 5.4%; tet(L), 5.4%; tet(M), 5.0%; tet(E), 3.7%; tet(C), 3.3%; tet(S), 2.5%; and tet(K), 0.8%. Various antimicrobial resistance genes were found in new carriers: blaTEM in Lactococcus garvieae, Myroides odoratimimus, Aeromonas hydrophila, Staphylococcus sciuri, Raoultella terrigena, Macrococcus caseolyticus, Acinetobacter ursingii, Sphingobacterium sp., and Oceanobacillus sp.; blaCMY-2 in Lactococcus lactis, Klebsiella oxytoca, Serratia marcescens, Acinetobacter baumannii, and Myroides phaeus; tet(L) in M. caseolyticus; sul1 in Vibrio cincinnatiensis; sul2 in Acinetobacter bereziniae, Acinetobacter johnsonii, and V. cincinnatiensis; and the class 1 integron and gene cassette aadA2 in V. cincinnatiensis. Approximately 6.6% of isolates contained class 1 integrons, and one isolate harbored class 2 integrons. Plasmid associated intI1 and androgen receptor- encoding genes were transferred into Escherichia coli J53 and E. coli DH5α by conjugation and transformation experiments, respectively. Our study highlights the importance of aerobic bacteria from pork as reservoirs for antimicrobial resistance genes and mobile genetic elements that can readily be transferred intra- and interspecies.
Topics: Abattoirs; Animals; Anti-Bacterial Agents; Bacteria; Bacterial Proteins; China; Drug Resistance, Bacterial; Food Handling; Integrons; Plasmids; Red Meat; Swine
PubMed: 27052863
DOI: 10.4315/0362-028X.JFP-15-455 -
Frontiers in Microbiology 2022The influence of microbiota composition and metabolisms on the safety and quality of fermented fish products is attracting increasing attention. In this study, the total...
The influence of microbiota composition and metabolisms on the safety and quality of fermented fish products is attracting increasing attention. In this study, the total viable count (TVC), pH, total volatile base nitrogen (TVB-N) as well as biogenic amines (BAs) of traditional fermented () were quantitatively determined. To comprehend microbial community variation and predict their functions during fermentation, 16S rRNA-based high-throughput sequencing (HTS) and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) were employed, respectively. The fresh samples stored without fermentation were used as controls. TVC and TVB-N values increased rapidly, and the content of BAs exceeded the permissible limit on day 2 in the controls, indicating serious spoilage of the fish. In contrast, a slower increase in TVC and TVB-N was observed and the content of BAs was within the acceptable limit throughout the fermentation of . Significant differences in microbiota composition were observed between and the controls. The bacterial community composition of was relatively simple and was identified as the dominant microbial group. The accumulation of histamine was inhibited in which was positively correlated with the relative abundance of , , , , et al. based on Redundancy analysis (RDA), while showed a positive correlation with tyramine, cadaverine, and putrescine. Functional predictions, based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis, revealed that the relative abundance of metabolic function exhibited a decreasing trend with prolonged fermentation time and the abundance of metabolism-related genes was relatively stable in the later stage of fermentation. Those metabolisms related to the formation of BAs like histidine metabolism and arginine metabolism were inhibited in . This study has accompanied microbiota analysis and functional metabolism with the accumulation of BAs to trace their correspondences, clarifying the roles of microorganisms in the inhibition of BAs during fermentation of
PubMed: 36406411
DOI: 10.3389/fmicb.2022.1030789 -
Journal of Dairy Science Oct 2020The objective of this work was to determine the effect of milk bactofugation on the counts and microbial diversity of mesophilic (MT), psychrotrophic (PT), and...
The objective of this work was to determine the effect of milk bactofugation on the counts and microbial diversity of mesophilic (MT), psychrotrophic (PT), and thermophilic (TT) thermoduric bacteria and its potential as a technological method to remove spoilage microorganisms resistant to pasteurization. Different batches of raw milk from 69 dairy farms divided into sets in 3 bulk tanks (A, B, C) were evaluated at different times during the technological process. As the raw milk was preheated (∼55°C) immediately before bactofugation (10,000 × g), the effect of bactofugation was estimated by comparing the counts in raw, preheated, and bactofuged milk. This centrifugation was sufficient to reduce the isolation of 88% of the MT in preheated milk. For PT, it was possible to verify a reduction of 72.5% in batch C. The TT were not recovered at higher detection limits (<5 cfu/mL). For diversity, 310 isolates were identified using a molecular approach; 15 species of contaminating thermoduric bacteria were identified from raw and preheated milk, and only 6 species were recovered in bactofuged milk. Only MT were recovered from the bactofuged milk, mainly the species Lysinibacillus fusiformis (61.7%) and Bacillus licheniformis (12.3%). Both species are known to be endospore-forming psychrotrophs and have proteolytic or lipolytic activity. The bactofugation of raw milk reduced the number of isolates of B. licheniformis, Bacillus toyonensis, Micrococcus aloeverae, and Aestuariimicrobium kwangyangense by 33, 43, 86, and 92%, respectively, and reduced the isolates of Macrococcus caseolyticus, Lysinibacillus varians, Carnobacterium divergens, Microbacterium hominis, Kocuria indica, Micrococcus yunnanensis, Gordonia paraffinivorans, Bacillus invictae, and Kocuria kristinae to undetectable levels. The results of this study indicate that bactofugation can be applied by the dairy industry to reduce pasteurization-resistant microorganisms in combination with prophylactic measures to prevent the contamination of raw milk by spores and vegetative forms of bacteria.
Topics: Actinobacteria; Animals; Bacillaceae; Bacillus; Bacteria, Thermoduric; Carnobacterium; Centrifugation; Micrococcaceae; Micrococcus; Milk; Propionibacteriaceae; Staphylococcaceae
PubMed: 32828509
DOI: 10.3168/jds.2020-18591 -
Frontiers in Nutrition 2022Bigeye tuna () is an economically valuable ocean fish species. It is susceptible to contamination during storage and transportation. Having proper transportation...
Bigeye tuna () is an economically valuable ocean fish species. It is susceptible to contamination during storage and transportation. Having proper transportation packaging and stable temperature during transportation are critical to prevent quality deterioration. However, the influence of packaging on retaining freshness in transit remains unknown. Here, the impact of different transportation packaging on the quality and microbiological variation of bigeye tuna during the logistics process was investigated by measuring physical-chemical indexes and microbial diversity. It turned out that aluminum foil paper (AFP) group had minimum temperature fluctuation, exhibited preferable water retaining capacity and color protection effect. AFP packaging could efficiently prevent TVB-N increase and microbial growth. After 40 h, the TVB-N value was 21.28 mg/100 g and microbial total plate count was 3.53 lg CFU/g, which was within the acceptable range. Temperature fluctuations and packaging materials had a major effect on the microbial community structure of bigeye tuna. , and were dominant in the AFP group, while , and were dominant in the expanded polystyrene foam (EPSF) and European logistics (EUL) groups. AFP packaging could effectively slow down the growth and reproduction of , restraining the growth of microorganisms and preserve the quality of bigeye tuna. This study provides insights into understanding the effects of packaging material on maintaining quality during logistics transportation.
PubMed: 36159488
DOI: 10.3389/fnut.2022.998377 -
Foods (Basel, Switzerland) Oct 2023In this study, we determined and identified the bacterial diversity of different types of artisanal and industrially produced cheese. The antibiotic (erythromycin,...
In this study, we determined and identified the bacterial diversity of different types of artisanal and industrially produced cheese. The antibiotic (erythromycin, chloramphenicol, kanamycin, ampicillin, clindamycin, streptomycin, tetracycline, and gentamicin) and biocide (peracetic acid, sodium hypochlorite, and benzalkonium chloride) resistance of clinically relevant bacteria was determined as follows: , , sp., , , , , , , , sp., , , , , and Also, the effect of the sub-inhibitory concentration of three biocides on antibiotic resistance was determined. The microbiota of evaluated dairy products comprise diverse and heterogeneous groups of bacteria with respect to antibiotic and disinfectant tolerance. The results indicated that resistance was common in the case of ampicillin, chloramphenicol, erythromycin, and streptomycin. sp. SCSSZT2/3, SRGT/1, SAT/1, MTT/5, and SIJ/2 showed resistance to most antibiotics. The tested bacteria showed sensitivity to peracetic acid and a different level of tolerance to benzalkonium chloride and sodium hypochlorite. The inhibition zone diameter of antibiotics against SZT/2, JS11, CSKO2, and GRT/10 was affected only by the sub-inhibitory concentration of peracetic acid.
PubMed: 37959056
DOI: 10.3390/foods12213937 -
Antimicrobial Agents and Chemotherapy Apr 2010Macrococcus is a bacterial genus that is closely related to Staphylococcus, which typically is isolated from animal skin and products. The genome analysis of...
Macrococcus is a bacterial genus that is closely related to Staphylococcus, which typically is isolated from animal skin and products. The genome analysis of multidrug-resistant Macrococcus caseolyticus strain JCSC5402, isolated from chicken, previously led to the identification of plasmid pMCCL2, which carries a transposon containing an unusual form of the Macrococcus mec gene complex (mecA(m)-mecR1(m)-mecI(m)-blaZ(m)). In M. caseolyticus strain JCSC7096, this mec transposon containing the mec gene complex (designated Tn6045 in this study) was found integrated downstream of orfX on the chromosome. Tn6045 of JCSC7096 was bracketed by the direct repeat sequences (DR) specifically recognized by cassette chromosome recombinase (CCR). A non-mecA-containing staphylococcal cassette chromosome (SCC) element, designated SCC(7096), was integrated next to the mec transposon and separated from the latter by a DR. Nested PCR experiments showed that the mec transposon not only was excised singly but also coexcised with SCC(7096) from the chromosome at the DRs. The coexcised elements formed the extrachromosomal closed circular DNA of the SCCmec-like element. SCCmec is known to be the mobile element conveying methicillin (meticillin) resistance in staphylococci. However, its origin has been unknown. Our observation revealed a potential mechanism of the generation of a new SCCmec-like element in M. caseolyticus, a commensal bacterium of food animals.
Topics: Animals; Base Sequence; Chickens; DNA Primers; DNA Transposable Elements; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Genes, Bacterial; Genome, Bacterial; Methicillin Resistance; Molecular Sequence Data; Multigene Family; Phylogeny; Plasmids; Staphylococcaceae; Staphylococcus
PubMed: 20086147
DOI: 10.1128/AAC.00575-09 -
One Health (Amsterdam, Netherlands) Dec 2021The emergence and spread of multidrug-resistant organisms (MDROs) represent a threat to human and animal health.
BACKGROUND
The emergence and spread of multidrug-resistant organisms (MDROs) represent a threat to human and animal health.
OBJECTIVES
To assess duration of carriage of MDROs in dogs and cats presented to veterinary clinics/hospitals in Switzerland. To estimate prevalence, duration of and risk factors for MDRO carriage in their owners and the occurrence of co-carriage in owner-pet pairs.
METHODS
Prospective, longitudinal, observational study. Nasal swabs and fecal samples were collected from 50 owners of dogs and cats presented to 3 large veterinary hospitals, 1 medium-sized clinic and 1 practice. If pet or owner tested positive for a MDRO, follow-up samples were collected for up to 8 months. Methicillin-resistant (MR) , MR , MR coagulase-negative staphylococci (MRCoNS), MR spp., cephalosporinase- and carbapenemase-producing (CP) Enterobacterales were isolated and further characterized by MALDI-TOF MS, microdilution, β-lactam resistance gene detection, REP/ERIC-PCR, multilocus sequence typing or whole-genome sequencing. Risk factors for MDRO carriage in owners were explored based on questionnaire-derived data.
RESULTS
Five out of 50 owners carried 3rd generation cephalosporin-resistant Enterobacterales (3GC-R-Ent.), and 5/50 MRCoNS. In 3 dogs and 4 cats carriage of 3GC-R-Ent. persisted for up to 136 days after discharge (median 99 days, IQR 83 days, range 36-136 days), in two cats isolates were carbapenem-resistant. Owner-pet co-carriage was not observed. No specific risk factors for MDRO carriage in owners were identified.
CONCLUSIONS
After discharge from veterinary care, dogs and cats may carry 3GC-R-Ent. for prolonged time periods. Carriage of MDROs was common in owners, but pet-owner co-carriage of the same MDRO was not observed.
PubMed: 34522760
DOI: 10.1016/j.onehlt.2021.100322