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Insects Jul 2022Arthropods are reported to serve as vectors of transmission of pathogenic microorganisms to humans, animals, and the environment. The aims of our study were (i) to...
Arthropods are reported to serve as vectors of transmission of pathogenic microorganisms to humans, animals, and the environment. The aims of our study were (i) to identify the external bacteriota of spiders inhabiting a chicken farm and slaughterhouse and (ii) to detect antimicrobial resistance of the isolates. In total, 102 spiders of 14 species were collected from a chicken farm, slaughterhouse, and buildings located in west Slovakia in 2017. Samples were diluted in peptone buffered water, and Tryptone Soya Agar (TSA), Triple Sugar Agar (TSI), Blood Agar (BA), and Anaerobic Agar (AA) were used for inoculation. A total of 28 genera and 56 microbial species were isolated from the samples. The most abundant species were (28 isolates) and (28 isolates). The least isolated species were (one isolate), (two isolates), (two isolates), and (two isolates). There were differences in microbial composition between the samples originating from the slaughterhouse, chicken farm, and buildings. The majority of the bacterial isolates resistant to antibiotics were isolated from the chicken farm. The isolation of potentially pathogenic bacteria such as , , and spp., which possess multiple drug resistance, is of public health concern.
PubMed: 36005303
DOI: 10.3390/insects13080680 -
International Journal of Food... Nov 2023Penicillium nordicum is one of the major producers of ochratoxin A (OTA) in dry-cured ham. Staphylococcus xylosus Sx8 and Staphylococcus equorum Se31 have been...
Penicillium nordicum is one of the major producers of ochratoxin A (OTA) in dry-cured ham. Staphylococcus xylosus Sx8 and Staphylococcus equorum Se31 have been previously proposed as biocontrol agents (BCAs) to prevent the OTA contamination, although their antifungal mode of action has not been established yet. Thus, the aim of this work was to elucidate their mode of action against P. nordicum in a dry-cured ham model system. For this, the effect of live cells, dead cells, and cell-free broth; the nutritional utilisation pattern, niche overlap index (NOI), interactions by dual-culture assays, antifungal effect of volatile compounds, OTA detoxification, and effect on fungal proteome were determined. No fungal growth was observed after 14 days of co-culture with live cells of each staphylococcus at 15 or 20 °C. However, such inhibition was not observed with either dead cells or extracellular extracts. The number of carbon sources utilised by P. nordicum was higher than those used by both cocci at 20 °C, whilst the opposite occurred at 15 °C. According to NOI, nutritional dominance depends on temperature, at 20 °C P. nordicum dominated the niche, but at 15 °C the mould is dominated by the BCAs. The volatile pattern generated by each coccus did not show antifungal effect, and both staphylococci failed to degrade or adsorb OTA. However, in the interaction assay, S. xylosus and S. equorum were able to decrease the fungal growth and its OTA production. In addition, proteomic analyses showed changes in the abundance of proteins related to the cell wall integrity (CWI), carbohydrate metabolism and the biosynthesis of secondary metabolites such as OTA. In conclusion, overall, the antagonistic effects of the two studied cocci against P. nordicum are greater at 15 °C than at 20 °C, being linked to competition for space and nutrients, triggering alterations in CWI pathway, OTA biosynthesis, and carbohydrate metabolism.
Topics: Food Microbiology; Pork Meat; Proteomics; Antifungal Agents; Meat Products; Ochratoxins; Penicillium; Staphylococcus
PubMed: 37523903
DOI: 10.1016/j.ijfoodmicro.2023.110342 -
MSphere Aug 2023The observation that molds can inhibit the growth of was a catalyst for the antibiotic revolution. Considerable attention has been paid to purified metabolites that...
The observation that molds can inhibit the growth of was a catalyst for the antibiotic revolution. Considerable attention has been paid to purified metabolites that inhibit bacteria, but little is known about how species impact the ecology and evolution of bacteria in multispecies microbial communities. Here, we investigated how four different species of can impact global transcription and evolution of a widespread species () using the cheese rind model microbiome. Through RNA sequencing, we identified a core transcriptional response of against all five tested strains, including upregulation of thiamine biosynthesis, fatty acid degradation, and amino acid metabolism as well as downregulation of genes involved in the transport of siderophores. In a 12-week evolution experiment where we co-cultured with the same strains, we observed surprisingly few non-synonymous mutations across populations evolved with the species. A mutation in a putative DHH family phosphoesterase gene only occurred in populations evolved without and decreased the fitness of when co-cultured with an antagonistic strain. Our results highlight the potential for conserved mechanisms of interactions and demonstrate how fungal biotic environments may constrain the evolution of bacterial species.IMPORTANCEFungi and bacteria are commonly found co-occurring both in natural and synthetic microbiomes, but our understanding of fungal-bacterial interactions is limited to a handful of species. Conserved mechanisms of interactions and evolutionary consequences of fungal-bacterial interactions are largely unknown. Our RNA sequencing and experimental evolution data with species and the bacterium demonstrate that divergent fungal species can elicit conserved transcriptional and genomic responses in co-occurring bacteria. molds are integral to the discovery of novel antibiotics and production of certain foods. By understanding how species affect bacteria, our work can further efforts to design and manage -dominated microbial communities in industry and food production.
Topics: Transcriptome; Cheese; Penicillium; Bacteria; Staphylococcus; Fungi; Anti-Bacterial Agents
PubMed: 37219436
DOI: 10.1128/msphere.00047-23 -
Scientific Reports Sep 2022Staphylococcus equorum strain KM1031 is resistant to chloramphenicol, erythromycin and lincomycin. To shed light on the genetic factors underlying these antibiotic...
Staphylococcus equorum strain KM1031 is resistant to chloramphenicol, erythromycin and lincomycin. To shed light on the genetic factors underlying these antibiotic resistances, we determined the global gene expression profile of S. equorum KM1031 using RNA sequencing. During chloramphenicol, erythromycin and lincomycin treatment, 8.3% (183/2,336), 16.0% (354/2,336), and 2.9% (63/2,336) of S. equorum KM1031 genes exhibited significant differences in expression, respectively. These three antibiotics upregulated genes related to efflux and downregulated genes related to transporters. Antibiotic treatment also upregulated osmoprotectant-related genes involved in salt tolerance. To identify specific genes functionally related to antibiotic resistance, we compared the genome of strain KM1031 with those of three S. equorum strains that are sensitive to these three antibiotics. We identified three genes of particular interest: an antibiotic biosynthesis monooxygenase gene (abm, AWC34_RS01805) related to chloramphenicol resistance, an antibiotic ABC transporter ATP-binding protein gene (msr, AWC34_RS11115) related to erythromycin resistance, and a lincosamide nucleotydyltransferase gene (lnuA, AWC34_RS13300) related to lincomycin resistance. These genes were upregulated in response to the corresponding antibiotic; in particular, msr was upregulated more than fourfold by erythromycin treatment. Finally, the results of RNA sequencing were validated by quantitative real-time PCR. This transcriptomic analysis provides genetic evidence regarding antibiotic stress responses of S. equorum strain KM1031.
Topics: ATP-Binding Cassette Transporters; Adenosine Triphosphate; Anti-Bacterial Agents; Chloramphenicol; Erythromycin; Fermented Foods; Lincomycin; Mixed Function Oxygenases; Staphylococcus; Transcriptome
PubMed: 36109627
DOI: 10.1038/s41598-022-19897-9 -
International Journal of Environmental... Jul 2021Dry-cured sausages are traditional in Mediterranean countries, and Paio do Alentejo (PA) is one of the most popular in South Portugal. The aim of the present work was to...
Dry-cured sausages are traditional in Mediterranean countries, and Paio do Alentejo (PA) is one of the most popular in South Portugal. The aim of the present work was to evaluate the effect of combined starters on the safety and quality of PA preserving its sensory quality. Physicochemical parameters, namely pH and water activity (a), microbiological parameters, biogenic amines, color, texture, and sensory attributes were assessed. Three starter cultures were used, namely S2M7 and CV3C2, both separate and combined with the 2RB4 yeast strain at a concentration of 10 cfu/g. Dextrose 0.25% was added to the meat batter. Starters had a significant effect on the reduction of a values (0.845 to 0.823). The treatment with as well as the co-inoculation of with effectively reduced the counts to undetectable levels. Sausages co-inoculated with S2M7/ CV3C2 showed a significant reduction in the content of vasoactive amines, namely tryptamine (26.21 to 15.70) and β-phenylethylamine (4.80 to 3.69). Regarding texture, control PA showed higher hardness values, and the starters promoted the cohesiveness of the batter while reducing chewiness. The studied starters did not compromise the sensory characteristics of PA.
Topics: Biogenic Amines; Fermentation; Food Microbiology; Latilactobacillus sakei; Meat Products; Portugal; Staphylococcus
PubMed: 34281032
DOI: 10.3390/ijerph18137100 -
Food Microbiology Aug 2021The microbial composition of the food production environment plays an important role in food safety and quality. This study employed both 16 S rRNA gene sequencing... (Comparative Study)
Comparative Study
The microbial composition of the food production environment plays an important role in food safety and quality. This study employed both 16 S rRNA gene sequencing technology and culture-based techniques to investigate the bacterial microbiota of an egg production facility comprising of both free-range and conventional cage housing systems. The study also aimed to detect the presence of Salmonella enterica and determine whether its presence was positively or negatively associated with other taxa. Our findings revealed that microbiota profiles of free-range and cage houses differ considerably in relation to the relative abundance and diversity with a number of taxa unique to each system and to individual sampling sites within sheds. Core to each housing system were known inhabitants of the poultry gastrointestinal tracts, Romboutsia and Turicibacter, as well as common spoilage bacteria. Generally, free-range samples contained fewer taxa and were dominated by Staphylococcus equorum, differentiating them from the cage samples. Salmonella enterica was significantly associated with the presence of a taxa belonging to the Carnobacteriaceae family. The results of this study demonstrate that the diversity and composition of the microbiota is highly variable across egg layer housing systems, which could have implications for productivity, food safety and spoilage.
Topics: Animal Husbandry; Animals; Bacteria; Chickens; Eggs; Female; Male; Microbiota; Oviposition; Salmonella enterica
PubMed: 33653527
DOI: 10.1016/j.fm.2021.103754 -
Scientific Reports Jul 2023The foodborne bacterium Staphylococcus equorum strain KS1030 harbours plasmid pSELNU1, which encodes a lincomycin resistance gene. pSELNU1 undergoes horizontal transfer...
The foodborne bacterium Staphylococcus equorum strain KS1030 harbours plasmid pSELNU1, which encodes a lincomycin resistance gene. pSELNU1 undergoes horizontal transfer between bacterial strains, thus spreading antibiotic resistance. However, the genes required for horizontal plasmid transfer are not encoded in pSELNU1. Interestingly, a relaxase gene, a type of gene related to horizontal plasmid transfer, is encoded in another plasmid of S. equorum KS1030, pKS1030-3. The complete genome of pKS1030-3 is 13,583 bp long and encodes genes for plasmid replication, biofilm formation (the ica operon), and horizontal gene transfer. The replication system of pKS1030-3 possesses the replication protein-encoding gene repB, a double-stranded origin of replication, and two single-stranded origins of replication. The ica operon, relaxase gene, and a mobilization protein-encoding gene were detected in pKS1030-3 strain-specifically. When expressed in S. aureus RN4220, the ica operon and relaxase operon of pKS1030-3 conferred biofilm formation ability and horizontal gene transfer ability, respectively. The results of our analyses show that the horizontal transfer of pSELNU1 of S. equorum strain KS1030 depends on the relaxase encoded by pKS1030-3, which is therefore trans-acting. Genes encoded in pKS1030-3 contribute to important strain-specific properties of S. equorum KS1030. These results could contribute to preventing the horizontal transfer of antibiotic resistance genes in food.
Topics: Staphylococcus aureus; Staphylococcus; Plasmids; Biofilms
PubMed: 37429971
DOI: 10.1038/s41598-023-38274-8 -
Journal of Dairy Science Aug 2018The role of non-aureus staphylococci (NAS) in the risk of acquisition of intramammary infections with Staphylococcus aureus is vague and still under debate. The...
The role of non-aureus staphylococci (NAS) in the risk of acquisition of intramammary infections with Staphylococcus aureus is vague and still under debate. The objectives of this study were to (1) investigate the distribution patterns of NAS species from milk and teat skin in dairy herds with automatic milking systems, and (2) examine if the isolated NAS influences the expression of S. aureus virulence factors controlled by the accessory gene regulator (agr) quorum sensing system. In 8 herds, 14 to 20 cows with elevated somatic cell count were randomly selected for teat skin swabbing and aseptic quarter foremilk samples from right hind and left front quarters. Teat skin swabs were collected using the modified wet-dry method and milk samples were taken aseptically for bacterial culture. Colonies from quarters with suspicion of having NAS in milk or teat skin samples (or both) were subjected to MALDI-TOF assay for species identification. To investigate the interaction between S. aureus and NAS, 81 isolates NAS were subjected to a qualitative β-galactosidase reporter plate assay. In total, 373 NAS isolates were identified representing 105 from milk and 268 from teat skin of 284 quarters (= 142 cows). Sixteen different NAS species were identified, 15 species from teat skin and 10 species from milk. The most prevalent NAS species identified from milk were Staphylococcus epidermidis (50%), Staphylococcus haemolyticus (15%), and Staphylococcus chromogenes (11%), accounting for 76%. Meanwhile, the most prevalent NAS species from teat skin were Staphylococcus equorum (43%), S. haemolyticus (16%), and Staphylococcus cohnii (14%), accounting for 73%. Using reporter gene fusions monitoring transcriptional activity of key virulence factors and regulators, we found that out of 81 supernatants of NAS isolates, 77% reduced expression of hla, encoding a-hemolysin, 70% reduced expression of RNAIII, the key effector molecule of agr, and 61% reduced expression of spa encoding protein A of S. aureus, respectively. Our NAS isolates showed 3 main patterns: (1) downregulation effect such as S. chromogenes (milk) and Staphylococcus xylosus (milk and teat), (2) no effect such as Staphylococcus sciuri (teat) and S. vitulinus (teat), and the third pattern (c) variable effect such as S. epidermidis (milk and teat) and S. equorum (milk and teat). The pattern of cross-talk between NAS species and S. aureus virulence genes varied according to the involved NAS species, habitat type, and herd factors. The knowledge of how NAS influences S. aureus virulence factor expression could explain the varying protective effect of NAS on S. aureus intramammary infections.
Topics: Animals; Cattle; Female; Mammary Glands, Animal; Mastitis, Bovine; Milk; Staphylococcal Infections; Staphylococcus; Staphylococcus aureus
PubMed: 29778469
DOI: 10.3168/jds.2017-14311 -
International Journal of Molecular... Jul 2023In food, bacteria carrying antibiotic resistance genes could play a prominent role in the spread of resistance. populations can become large in a number of fermented...
In food, bacteria carrying antibiotic resistance genes could play a prominent role in the spread of resistance. populations can become large in a number of fermented foods, yet the antibiotic resistance properties of this species have been little studied. In this work, the resistance/susceptibility (R/S) profile of strains ( = 30) from cheese to 16 antibiotics was determined by broth microdilution. The minimum inhibitory concentration (MIC) for all antibiotics was low in most strains, although higher MICs compatible with acquired genes were also noted. Genome analysis of 13 strains showed the resistome to be composed of intrinsic mechanisms, acquired mutations, and acquired genes. As such, a plasmidic gene providing resistance to chloramphenicol was found in one strain; this was able to provide resistance to after electroporation. An (A) polymorphic gene was identified in five strains. The Mrs(A) variants were associated with variable resistance to erythromycin. However, the genetic data did not always correlate with the phenotype. As such, all strains harbored a polymorphic / gene, although only one acquired copy was associated with strong resistance to fosfomycin. Similarly, a plasmid-associated operon encoding a penicillinase system was identified in five ampicillin- and penicillin G-susceptible strains. Identified genes not associated with phenotypic resistance further included (C) in two strains and in all strains. The antibiotic R/S status and gene content of strains intended to be employed in food systems should be carefully determined.
Topics: Anti-Bacterial Agents; Cheese; Food Microbiology; Drug Resistance, Microbial; Microbial Sensitivity Tests
PubMed: 37511416
DOI: 10.3390/ijms241411657 -
Journal of Dairy Science Jan 2017Coagulase-negative staphylococci (CNS) have become the main pathogens causing bovine mastitis in recent years. A huge variation in species distribution among herds has...
Coagulase-negative staphylococci (CNS) have become the main pathogens causing bovine mastitis in recent years. A huge variation in species distribution among herds has been observed in several studies, emphasizing the need to identify subgroup- and species-specific herd-level factors to improve our understanding of the differences in ecological and epidemiological nature between species. The use of bulk milk samples enables the inclusion of a large(r) number of herds needed to identify herd-level risk factors and increases the likelihood of recovering enough isolates per species needed for conducting subgroup- and, eventually, species-specific analyses at the same time. This study aimed to describe the prevalence and distribution of CNS species in bulk milk samples and to identify associated subgroup- and species-specific herd-level factors. Ninety percent of all bulk milk samples yielded CNS. Staphylococcus equorum was the predominant species, followed by Staphylococcus haemolyticus and Staphylococcus epidermidis. A seasonal effect was observed for several CNS species. Bulk milk samples from herds with a loose-pack or a tiestall housing system were more likely to yield CNS species compared with herds with a freestall barn, except for S. epidermidis, Staphylococcus simulans, and Staphylococcus cohnii. In September, herds in which udders were clipped had lower odds of yielding Staphylococcus chromogenes, S. simulans, and Staphylococcus xylosus, the CNS species assumed to be most relevant for udder health, in their bulk milk than herds in which udder clipping was not practiced. Bulk milk of herds participating in a monthly veterinary udder health-monitoring program was more likely to yield these 3 CNS species. Herds always receiving their milk quality premium or predisinfecting teats before attachment of the milking cluster had lower odds of having S. equorum in their bulk milk. Herds not using a single dry cotton or paper towel for each cow during premilking udder preparation were more likely to have S. cohnii-positive bulk milk. Herds in which flushing with hot water or steam of the milking cluster after having milked a cow with a (sub)clinical mastitis was applied, were less likely to yield S. simulans, S. haemolyticus, and S. cohnii in their bulk milk. Always wearing gloves during milking decreased the odds of having Staphylococcus devriesei-positive bulk milk. Tap water from the public drinking system used as drinking water increased the odds of yielding S. simulans in the bulk milk. In conclusion, CNS are highly prevalent in bulk milk and might originate from the environment for some species (we hypothesize this is true for S. equorum or S. cohnii), or from within the udder (e.g., for S. simulans). Studies collecting bulk milk and quarter milk samples at the same time along with environmental samples are needed to determine the exact origin of the different (subgroups of) CNS species present in bulk milk using strain-typing techniques.
Topics: Animals; Cattle; Coagulase; Female; Mastitis, Bovine; Milk; Prevalence; Risk Factors; Staphylococcal Infections; Staphylococcus
PubMed: 27865514
DOI: 10.3168/jds.2016-11476