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Laboratory Animal Research Aug 2023Skin ulcers, skin dermatitis and skin infections are common phenomena in colonies of laboratory mice and are often found at increased prevalence in certain... (Review)
Review
Skin ulcers, skin dermatitis and skin infections are common phenomena in colonies of laboratory mice and are often found at increased prevalence in certain immunocompromised strains. While in many cases these skin conditions are mild, in other cases they can be severe and lead to animal morbidity. Furthermore, the presence of skin infections and ulcerations can complicate the interpretation of experimental protocols, including those examining immune cell activation. Bacterial species in the genus Staphylococcus are the most common pathogens recovered from skin lesions in mice. In particular, Staphylococcus aureus and Staphylococcus xylosus have both been implicated as pathogens on murine skin. Staphylococcus aureus is a well-known pathogen of human skin, but S. xylosus skin infections in humans have not been described, indicating that there is a species-specific difference in the ability of S. xylosus to serve as a skin pathogen. The aim of this review is to summarize studies that link S. aureus and S. xylosus to skin infections of mice and to describe factors involved in their adherence to tissue and their virulence. We discuss potential differences in mouse and human skin that might underlie the ability of S. xylosus to act as a pathogen on murine skin, but not human skin. Finally, we also describe mouse mutants that have shown increased susceptibility to skin infections with staphylococcal bacteria. These mutants point to pathways that are important in the control of commensal staphylococcal bacteria. The information here may be useful to researchers who are working with mouse strains that are prone to skin infections with staphylococcal bacteria.
PubMed: 37533118
DOI: 10.1186/s42826-023-00169-0 -
Microorganisms Dec 2021The biofilm associated protein (Bap) is recognised as the essential component for biofilm formation in V329 and has been predicted as important for other species as...
The biofilm associated protein (Bap) is recognised as the essential component for biofilm formation in V329 and has been predicted as important for other species as well. Although Bap orthologs are also present in most strains, their contribution to biofilm formation has not yet been demonstrated. In this study, different experimental approaches were used to elucidate the effect of Bap on biofilm formation in and the motif structure of two biofilm-forming strains TMW 2.1023 and TMW 2.1523 was compared to Bap of V329. We found that despite an identical structural arrangement into four regions, Bap from differs in key factors to Bap of , i.e., isoelectric point of aggregation prone Region B, protein homology and type of repeats. Disruption of had no effect on aggregation behavior of selected strains and biofilm formation was unaffected (TMW 2.1023) or at best slightly reduced under neutral conditions (TMW 2.1523). Further, we could not observe any typical characteristics of a Bap-positive phenotype such as functional impairment by calcium addition and rough colony morphology on congo red agar (CRA). A dominating role of Bap in cell aggregation and biofilm formation as reported mainly for V329 was not observed. In contrast, this work demonstrates that functions of Bap cannot easily be extrapolated to Bap, which appears as non-essential for biofilm formation in this species. We therefore suggest that biofilm formation in follows different and multifactorial mechanisms.
PubMed: 34946212
DOI: 10.3390/microorganisms9122610 -
Infection and Drug Resistance 2022Drug resistance presents an ever-increasing global public health threat that involves all major microbial pathogens and antimicrobial drugs. Strains that are resistant...
PURPOSE
Drug resistance presents an ever-increasing global public health threat that involves all major microbial pathogens and antimicrobial drugs. Strains that are resistant to multiple drugs pose severe clinical problems and cost lives. However, systematic studies on cross-resistance of have been missing.
METHODS
Here, we investigated various mutations in the sequence of ribosomal proteins involved in cross-resistance. To understand this effect on a molecular basis and to further elucidate the role of cross-resistance, we computationally constructed the 3D model of the large ribosomal subunit from as well as its complexes with both tylosin and florfenicol. Meanwhile, all-atom molecular dynamics simulations was used. In addition, the regulation of protein networks also played an essential role in the development of cross-resistance in .
RESULTS
We discovered that the minimum inhibitory concentration against both tylosin and florfenicol of the mutant strain containing the insertion L22 97KRTSAIN98 changed dramatically. Further, we found that unique structural changes in the β-hairpin of L22 played a central role in this variant in the development of antibiotic resistance in . The regulation of protein networks also played an essential role in the development of cross-resistance in .
CONCLUSION
Our work provides insightful views into the mechanism of resistance that could be useful for the development of the next generation of antibiotics.
PubMed: 36304967
DOI: 10.2147/IDR.S379264 -
Microorganisms Aug 2017belongs to the vast group of coagulase-negative staphylococci. It is frequently isolated from meat products, either fermented or salted and dried, and is commonly used... (Review)
Review
belongs to the vast group of coagulase-negative staphylococci. It is frequently isolated from meat products, either fermented or salted and dried, and is commonly used as starter cultures in sausage manufacturing. Analysis of the genome together with expression in situ in a meat model revealed that this bacterium is well adapted to meat substrates, being able to use diverse substrates as sources of carbon and energy and different sources of nitrogen. It is well-equipped with genes involved in osmotic, oxidative/nitrosative, and acidic stress responses. It is responsible for the development of the typical colour of cured meat products via its nitrate reductase activity. It contributes to sensorial properties, mainly by the the catabolism of pyruvate and amino acids resulting in odorous compounds and by the limiting of the oxidation of fatty acids, thereby avoiding rancidity.
PubMed: 28850086
DOI: 10.3390/microorganisms5030052 -
Microbial Biotechnology Feb 2022Staphylococcus xylosus (S. xylosus)-induced cow mastitis is an extremely serious clinical problem. However, antibiotic therapy does not successfully treat S. xylosus...
Staphylococcus xylosus (S. xylosus)-induced cow mastitis is an extremely serious clinical problem. However, antibiotic therapy does not successfully treat S. xylosus infection because these bacteria possess a strong biofilm formation ability, which significantly reduces the efficacy of antibiotic treatments. In this study, we developed ceftiofur-loaded chitosan grafted with β-cyclodextrins (CD-g-CS) nanoparticles (CT-NPs) using host-guest interaction. These positively charged nanoparticles improved bacterial internalization, thereby significantly improving the effectiveness of antibacterial treatments for planktonic S. xylosus. Moreover, CT-NPs effectively inhibited biofilm formation and eradicated mature biofilms. After mammary injection in a murine model of S. xylosus-induced mastitis, CT-NPs significantly reduced bacterial burden and alleviated inflammation, thereby achieving optimized therapeutic efficiency for S. xylosus infection. In conclusion, this treatment strategy could improve the efficiency of antibiotic therapeutics and shows great potential in the treatment of S. xylosus infections.
Topics: Animals; Anti-Bacterial Agents; Biofilms; Cattle; Female; Humans; Mastitis; Mice; Nanoparticles; Staphylococcal Infections; Staphylococcus
PubMed: 34180582
DOI: 10.1111/1751-7915.13870 -
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 -
Microorganisms Oct 2021forms biofilm embedded in an extracellular polymeric matrix. As extracellular DNA (eDNA) resulting from cell lysis has been found in several staphylococcal biofilms, we...
forms biofilm embedded in an extracellular polymeric matrix. As extracellular DNA (eDNA) resulting from cell lysis has been found in several staphylococcal biofilms, we investigated biofilm in vitro by a microscopic approach and identified the mechanisms involved in cell lysis by a transcriptomic approach. Confocal laser scanning microscopy (CLSM) analyses of the biofilms, together with DNA staining and DNase treatment, revealed that eDNA constituted an important component of the matrix. This eDNA resulted from cell lysis by two mechanisms, overexpression of phage-related genes and of encoding a holin protein that is an effector of murein hydrolase activity. This lysis might furnish nutrients for the remaining cells as highlighted by genes overexpressed in nucleotide salvage, in amino sugar catabolism and in inorganic ion transports. Several genes involved in DNA/RNA repair and genes encoding proteases and chaperones involved in protein turnover were up-regulated. Furthermore, perceived osmotic and oxidative stresses and responded by up-regulating genes involved in osmoprotectant synthesis and in detoxification. This study provides new insight into the physiology of in biofilm.
PubMed: 34835318
DOI: 10.3390/microorganisms9112192 -
International Journal of Food... Aug 2020Staphylococcus xylosus, a coagulase-negative Staphylococcus, is frequently isolated from food products of animal origin and used as a starter culture in these products...
Staphylococcus xylosus, a coagulase-negative Staphylococcus, is frequently isolated from food products of animal origin and used as a starter culture in these products in which it contributes to their flavour, while Staphylococcus aureus, a coagulase-positive bacterium, causes foodborne intoxication and is implicated in a broad diversity of infections in medical sector, notably in nosocomial infections. S. xylosus and S. aureus are both capable of forming a biofilm and share the same ecological niches, thus we explored their interaction in biofilms with a view to limiting the risks associated with S. aureus. Cell-free supernatants of different strains of S. xylosus were able to inhibit the biofilm formation of S. aureus. The S. xylosus C2a strain released into the supernatant a molecule of molecular weight above 30 kDa that is resistant to proteolytic enzymes and inhibits the formation of S. aureus MW2 biofilm, though the mechanism involved has yet to be elucidated. Furthermore, S. xylosus C2a modified the architecture of S. aureus MW2 in co-culture biofilm. Confocal laser scanning microscopy revealed that S. aureus formed a biofilm with a flat and compact structure while in co-culture with S. xylosus the two species formed large juxtaposed aggregates throughout the period of incubation. This architecture made the S. aureus biofilm more susceptible to detachment.
Topics: Animals; Antibiosis; Biofilms; Coagulase; Food Microbiology; Foodborne Diseases; Staphylococcal Infections; Staphylococcus; Staphylococcus aureus
PubMed: 32449679
DOI: 10.1016/j.ijfoodmicro.2020.108653 -
Archives of Microbiology Dec 2021Staphylococcus xylosus is a gram-positive bacterium that has attracted much attention due to its increasing clinical appearance, frequently associated with serious...
Staphylococcus xylosus is a gram-positive bacterium that has attracted much attention due to its increasing clinical appearance, frequently associated with serious multidrug resistance cases. L-lactate dehydrogenase (LDH) has been related to drug resistance in several bacterial species. However, the mechanism of multidrug resistance in S. xylosus remains unclear as well as the involvement of LDH in such resistance. To explore the relationship between multidrug resistance and LDH in S. xylosus, we used tylosin-resistant S. xylosus as the parent strain to construct ldh knockout and complemented strains. Then, we tested their resistance to macrolides, lincosamides, tetracyclines, and aminoglycosides. In addition, the enzyme activity, metabolite content, and transcriptional level of key genes involved in the TCA cycle and thioredoxin system were determined to clarify the mechanism of resistance. We observed that the resistance to multiple antibiotics increased significantly after ldh knockout, especially that to lincomycin, whereas antibiotic sensitivity was partially restored in the complemented strain. The levels of pyruvate, nicotinamide adenine dinucleotide, and reactive oxygen species decreased significantly upon ldh knockout, and the activity of isocitrate dehydrogenase and malate dehydrogenase decreased. These results indicate that the lack of LDH promotes multidrug resistance in S. xylosus by inhibiting the TCA cycle and regulating the thioredoxin system.
Topics: Anti-Bacterial Agents; Drug Resistance, Multiple; L-Lactate Dehydrogenase; Staphylococcus
PubMed: 34962581
DOI: 10.1007/s00203-021-02625-8 -
IDCases 2021Prosthethic Joint Infection (PJI) is a severe complication following joint replacement. Late PJI can occur years after implantation by hematogenous seeding of a...
Prosthethic Joint Infection (PJI) is a severe complication following joint replacement. Late PJI can occur years after implantation by hematogenous seeding of a microbial agent. is a coagulase-negative commensal of the human skin and rarely associated with opportunistic human infections. We report the rare case of a 70-year old Patient suffering from knee pain 18 years after primary Total Knee Arthroplasty. Microbiological sampling detected as causative agent. The patient was successfully treated with a two-stage implant exchange and antibiotic therapy using co-amoxicillin and rifampicin/cotrimoxazol. This case illustrates the ability of to cause late PJI and the importance of not letting coagulase-negative Staphylococci be routinely categorized as contaminants of microbiological samples.
PubMed: 34036044
DOI: 10.1016/j.idcr.2021.e01160