Editorial

3 pages, 181 KiB

Open AccessEditorial

Biology and Pathogenesis of Staphylococcus Infection

by Valentina Virginia Ebani

Microorganisms 2020, 8(3), 383; https://doi.org/10.3390/microorganisms8030383 - 09 Mar 2020

Cited by 4 | Viewed by 2062

Members of the genus Staphylococcus still represent a topic of great relevance due to the numerous types of infections they cause in humans and animals [...] Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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20 pages, 3584 KiB

Open AccessArticle

Strategies to Prevent Biofilm Infections on Biomaterials: Effect of Novel Naturally-Derived Biofilm Inhibitors on a Competitive Colonization Model of Titanium by Staphylococcus aureus and SaOS-2 Cells

by Inés Reigada, Ramón Pérez-Tanoira, Jayendra Z. Patel, Kirsi Savijoki, Jari Yli-Kauhaluoma, Teemu J. Kinnari and Adyary Fallarero

Microorganisms 2020, 8(3), 345; https://doi.org/10.3390/microorganisms8030345 - 29 Feb 2020

Cited by 8 | Viewed by 3286

Abstract

Biofilm-mediated infection is a major cause of bone prosthesis failure. The lack of molecules able to act in biofilms has driven research aimed at identifying new anti-biofilm agents via chemical screens. However, to be able to accommodate a large number of compounds, the [...] Read more.

Biofilm-mediated infection is a major cause of bone prosthesis failure. The lack of molecules able to act in biofilms has driven research aimed at identifying new anti-biofilm agents via chemical screens. However, to be able to accommodate a large number of compounds, the testing conditions of these screenings end up being typically far from the clinical scenario. In this study, we assess the potential applicability of three previously discovered anti-biofilm compounds to be part of implanted medical devices by testing them on in vitro systems that more closely resemble the clinical scenario. To that end, we used a competition model based on the co-culture of SaOS-2 mammalian cells and Staphylococcus aureus (collection and clinical strains) on a titanium surface, as well as titanium pre-conditioned with high serum protein concentration. Additionally, we studied whether these compounds enhance the previously proven protective effect of pre-incubating titanium with SaOS-2 cells. Out of the three, DHA1 was the one with the highest potential, showing a preventive effect on bacterial adherence in all tested conditions, making it the most promising agent for incorporation into bone implants. This study emphasizes and demonstrates the importance of using meaningful experimental models, where potential antimicrobials ought to be tested for the protection of biomaterials in translational applications. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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22 pages, 3620 KiB

Open AccessArticle

Arginine Catabolic Mobile Element in Evolution and Pathogenicity of the Community-Associated Methicillin-Resistant Staphylococcus aureus Strain USA300

by Kaiyu Wu, John Conly, Jo-Ann McClure, Habib A. Kurwa and Kunyan Zhang

Microorganisms 2020, 8(2), 275; https://doi.org/10.3390/microorganisms8020275 - 18 Feb 2020

Cited by 8 | Viewed by 3093

Abstract

USA300 is a predominant community-associated methicillin-resistant Staphylococcus aureus strain which carries an arginine catabolic mobile element (ACME). ACME contains potential virulence factors including an arginine deiminase (arc) pathway and an oligopeptide permease (opp-3) system, which are proposed to play [...] Read more.

USA300 is a predominant community-associated methicillin-resistant Staphylococcus aureus strain which carries an arginine catabolic mobile element (ACME). ACME contains potential virulence factors including an arginine deiminase (arc) pathway and an oligopeptide permease (opp-3) system, which are proposed to play a role in bacterial virulence and transmission. However, the role of ACME in evolution and pathogenicity of USA300 remains to be elucidated. ACME and arcA deletion mutants were created by allelic replacement from a USA300 clinical isolate. By comparing wild type and isogenic ACME deletion USA300 strains, ACME was shown not to contribute to bacterial survival on plastic surfaces, and mouse skin surfaces. ACME did not contribute to bacterial virulence in cell invasion and cytotoxicity assays, invertebrate killing assays and a mouse skin infection model. Wild-type ACME negative USA300 clinical isolates showed similar associations with invasive anatomic sites as ACME positive isolates. Our experiments also demonstrated that ACME can spontaneously excise from the bacterial chromosome to generate an ACME deletion strain at a low frequency. Our results do not support that the ACME element alone is a significant factor in the transmission and virulence of USA300 strain, and ACME may have been coincidently incorporated into the genome of USA300. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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16 pages, 304 KiB

Open AccessArticle

Antimicrobial Activity of Essential Oils against Staphylococcus and Malassezia Strains Isolated from Canine Dermatitis

by Valentina Virginia Ebani, Fabrizio Bertelloni, Basma Najar, Simona Nardoni, Luisa Pistelli and Francesca Mancianti

Microorganisms 2020, 8(2), 252; https://doi.org/10.3390/microorganisms8020252 - 13 Feb 2020

Cited by 23 | Viewed by 4549

Abstract

Staphylococcus spp. bacteria are the most frequently involved agents in canine cutaneous infections. Treatment of these infections is based on antibiotic therapy, that often is not effective because of the antibiotic-resistance of the bacterial strains. Cutaneous staphylococcal infections are often complicated by Malassezia [...] Read more.

Staphylococcus spp. bacteria are the most frequently involved agents in canine cutaneous infections. Treatment of these infections is based on antibiotic therapy, that often is not effective because of the antibiotic-resistance of the bacterial strains. Cutaneous staphylococcal infections are often complicated by Malassezia yeasts, that may be resistant to the conventional antifungal drugs. The present investigation was aimed to evaluate the in vitro antimicrobial activity of some essential oils (EOs) in view of a potential cutaneous application. In detail, EOs obtained from lemon verbena (Aloysia triphylla L’Hèr. Britton), cinnamon (Cinnamomum zeylanicum J. Presl), myrrh (Commiphora myrrha (Nees) Engl. var. molmol), lemongrass (Cymbopogon citratus (DC.) Stapf), litsea (Litsea cubeba (Lour.) Pers.), lemon balm (Melissa officinalis L.), oregano (Origanum vulgare L.), savory (Satureja montana L.), and thyme (Thymus vulgaris L.) were assayed against Staphylococcus spp. and Malassezia pachydermatis strains previously isolated from dogs with dermatitis. All EOs were tested by agar disk diffusion and minimum inhibitory concentration methods to verify the antistaphylococcal activity, and by a microdilution method to evaluate the activity against M. pachydermatis. O. vulgare, T. vulgaris, and S. montana showed the best antibacterial activity against all the selected strains, with MICs ranging from 0.29 to 0.58 mg/mL, from 0.58 to 1.16 mg/mL, and from 0.56 to 1.12 mg/mL, respectively, whereas A. triphylla (1.03 mg/mL) and S. montana (1.8 mg/mL) were the most active against M. pachydermatis. After a proper in vivo evaluation, O. vulgare, T. vulgaris, and S. montana EOs could be a promising treatment to combat canine cutaneous mixed infections. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

18 pages, 1921 KiB

Open AccessArticle

Characterization of Staphylococcus intermedius Group Isolates Associated with Animals from Antarctica and Emended Description of Staphylococcus delphini

by Veronika Vrbovská, Ivo Sedláček, Michal Zeman, Pavel Švec, Vojtěch Kovařovic, Ondrej Šedo, Monika Laichmanová, Jiří Doškař and Roman Pantůček

Microorganisms 2020, 8(2), 204; https://doi.org/10.3390/microorganisms8020204 - 01 Feb 2020

Cited by 20 | Viewed by 4311

Abstract

Members of the genus Staphylococcus are widespread in nature and occupy a variety of niches, however, staphylococcal colonization of animals in the Antarctic environment has not been adequately studied. Here, we describe the first isolation and characterization of two Staphylococcus intermedius group (SIG) [...] Read more.

Members of the genus Staphylococcus are widespread in nature and occupy a variety of niches, however, staphylococcal colonization of animals in the Antarctic environment has not been adequately studied. Here, we describe the first isolation and characterization of two Staphylococcus intermedius group (SIG) members, Staphylococcus delphini and Staphylococcus pseudintermedius, in Antarctic wildlife. Staphylococcus delphini were found exclusively in Adélie penguins. The report of S. pseudintermedius from Weddell seals confirmed its occurrence in all families of the suborder Caniformia. Partial RNA polymerase beta-subunit (rpoB) gene sequencing, repetitive PCR fingerprinting with the (GTG)₅ primer, and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry gave consistent identification results and proved to be suitable for identifying SIG members. Comparative genomics of S. delphini isolates revealed variable genomic elements, including new prophages, a novel phage-inducible chromosomal island, and numerous putative virulence factors. Surface and extracellular protein distribution were compared between genomes and showed strain-specific profiles. The pathogenic potential of S. delphini was enhanced by a novel type of exfoliative toxin, trypsin-like serine protease cluster, and enterotoxin C. Detailed analysis of phenotypic characteristics performed on six Antarctic isolates of S. delphini and eight reference strains from different animal sources enabled us to emend the species description of S. delphini. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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14 pages, 2075 KiB

Open AccessArticle

Cysteine-Capped Hydrogels Incorporating Copper as Effective Antimicrobial Materials against Methicillin-Resistant Staphylococcus aureus

by John Jackson Yang, Yung-Chi Huang, Tsung-Hsien Chuang, Deron Raymond Herr, Ming-Fa Hsieh, Chun-Jen Huang and Chun-Ming Huang

Microorganisms 2020, 8(2), 149; https://doi.org/10.3390/microorganisms8020149 - 21 Jan 2020

Cited by 7 | Viewed by 3093

Abstract

Methicillin-resistant Staphylococcus aureus (S. aureus) (MRSA) has become an alarming threat to public health, and infected soft tissue. Antibiotics are commonly used to treat skin infection with MRSA, but the inappropriate use of antibiotics runs a considerable risk of generating resistant [...] Read more.

Methicillin-resistant Staphylococcus aureus (S. aureus) (MRSA) has become an alarming threat to public health, and infected soft tissue. Antibiotics are commonly used to treat skin infection with MRSA, but the inappropriate use of antibiotics runs a considerable risk of generating resistant S. aureus. In this study, we created a cysteine-capped hydrogel able to absorb and release copper, an ion with the capability of suppressing the growth of USA300, a community-acquired MRSA. The results of analysis of Fourier transform infrared spectroscopy (FTIR) revealed the binding of copper to a cysteine-capped hydrogel. The topical application of a cysteine-capped hydrogel binding with copper on USA300-infected skin wounds in the dorsal skin of Institute of Cancer Research (ICR) mice significantly enhanced wound healing, hindered the growth of USA300, and reduced the production of pro-inflammatory macrophage inflammatory protein 2-alpha (MIP-2) cytokine. Our work demonstrates a newly designed hydrogel that conjugates a cysteine molecule for copper binding. The cysteine-capped hydrogel can potentially chelate various antimicrobial metals as a novel wound dressing. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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24 pages, 3399 KiB

Open AccessArticle

Growth Mode and Physiological State of Cells Prior to Biofilm Formation Affect Immune Evasion and Persistence of Staphylococcus aureus

by Kirsi Savijoki, Ilkka Miettinen, Tuula A. Nyman, Maarit Kortesoja, Leena Hanski, Pekka Varmanen and Adyary Fallarero

Microorganisms 2020, 8(1), 106; https://doi.org/10.3390/microorganisms8010106 - 12 Jan 2020

Cited by 16 | Viewed by 5156

Abstract

The present study investigated Staphylococcus aureus ATCC25923 surfaceomes (cell surface proteins) during prolonged growth by subjecting planktonic and biofilm cultures (initiated from exponential or stationary cells) to label-free quantitative surfaceomics and phenotypic confirmations. The abundance of adhesion, autolytic, hemolytic, and lipolytic proteins decreased [...] Read more.

The present study investigated Staphylococcus aureus ATCC25923 surfaceomes (cell surface proteins) during prolonged growth by subjecting planktonic and biofilm cultures (initiated from exponential or stationary cells) to label-free quantitative surfaceomics and phenotypic confirmations. The abundance of adhesion, autolytic, hemolytic, and lipolytic proteins decreased over time in both growth modes, while an opposite trend was detected for many tricarboxylic acid (TCA) cycle, reactive oxygen species (ROS) scavenging, Fe-S repair, and peptidolytic moonlighters. In planktonic cells, these changes were accompanied by decreasing and increasing adherence to hydrophobic surface and fibronectin, respectively. Specific RNA/DNA binding (cold-shock protein CspD and ribosomal proteins) and the immune evasion (SpA, ClfA, and IsaB) proteins were notably more abundant on fully mature biofilms initiated with stationary-phase cells (SDBF) compared to biofilms derived from exponential cells (EDBF) or equivalent planktonic cells. The fully matured SDBF cells demonstrated higher viability in THP-1 monocyte/macrophage cells compared to the EDBF cells. Peptidoglycan strengthening, specific urea-cycle, and detoxification enzymes were more abundant on planktonic than biofilm cells, indicating the activation of growth-mode specific pathways during prolonged cultivation. Thus, we show that S. aureus shapes its surfaceome in a growth mode-dependent manner to reach high levofloxacin tolerance (>200-times the minimum biofilm inhibitory concentration). This study also demonstrates that the phenotypic state of the cells prior to biofilm formation affects the immune-evasion and persistence-related traits of S. aureus. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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17 pages, 2311 KiB

Open AccessArticle

Dendritic Cells Internalize Staphylococcus aureus More Efficiently than Staphylococcus epidermidis, but Do Not Differ in Induction of Antigen-Specific T Cell Proliferation

by Payal P. Balraadjsing, Esther C. de Jong, Willem J. B. van Wamel and Sebastian A. J. Zaat

Microorganisms 2020, 8(1), 19; https://doi.org/10.3390/microorganisms8010019 - 20 Dec 2019

Cited by 8 | Viewed by 2895

Abstract

Staphylococcus aureus and Staphylococcus epidermidis are related species which can cause predominantly acute and subacute infections, respectively. Differences in human adaptive immune responses to these two species are not well understood. Dendritic cells (DCs) have an important role in the control and regulation [...] Read more.

Staphylococcus aureus and Staphylococcus epidermidis are related species which can cause predominantly acute and subacute infections, respectively. Differences in human adaptive immune responses to these two species are not well understood. Dendritic cells (DCs) have an important role in the control and regulation of anti-staphylococcal T cell responses. Therefore, we aimed to compare the ability of S. aureus and S. epidermidis to influence the essential steps in human DC activation and subsequent antigen-specific CD4⁺ T cell proliferation, and to investigate the underlying mechanisms. Using multiple strains of both species, we observed that S. aureus was internalized more effectively than S. epidermidis by DCs but that both species were equally potent in activating these host cells, as evidenced by similar induction of DC maturation marker expression and antigen loading onto MHC-II molecules. The DCs stimulated by S. aureus strains not harboring superantigen (SAg) genes or by any of the S. epidermidis strains, induced low, likely physiological levels of T cell proliferation. Only DCs stimulated with S. aureus strains harboring SAg genes induced high levels of T cell proliferation. Taken together, S. aureus and S. epidermidis do not differently affect DC activation and ensuing antigen-specific T cell proliferation, unless a strain has the capacity to produce SAgs. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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12 pages, 753 KiB

Open AccessArticle

Activation of a Bovine Mammary Epithelial Cell Line by Ruminant-Associated Staphylococcus aureus is Lineage Dependent

by Jurriaan Hoekstra, Victor P. M. G. Rutten, Theo J. G. M. Lam, Kok P. M. Van Kessel, Mirlin P. Spaninks, J. Arjan Stegeman, Lindert Benedictus and Gerrit Koop

Microorganisms 2019, 7(12), 688; https://doi.org/10.3390/microorganisms7120688 - 12 Dec 2019

Cited by 9 | Viewed by 2931

Abstract

Bovine mastitis is a costly disease to the dairy industry and intramammary infections (IMI) with Staphylococcus aureus are a major cause of mastitis. Staphylococcus aureus strains responsible for mastitis in cattle predominantly belong to ruminant-associated clonal complexes (CCs). Recognition of pathogens by bovine [...] Read more.

Bovine mastitis is a costly disease to the dairy industry and intramammary infections (IMI) with Staphylococcus aureus are a major cause of mastitis. Staphylococcus aureus strains responsible for mastitis in cattle predominantly belong to ruminant-associated clonal complexes (CCs). Recognition of pathogens by bovine mammary epithelial cells (bMEC) plays a key role in activation of immune responsiveness during IMI. However, it is still largely unknown to what extent the bMEC response differs according to S. aureus CC. The aim of this study was to determine whether ruminant-associated S. aureus CCs differentially activate bMEC. For this purpose, the immortalized bMEC line PS was stimulated with S. aureus mastitis isolates belonging to four different clonal complexes (CCs; CC133, CC479, CC151 and CC425) and interleukin 8 (IL-8) release was measured as indicator of activation. To validate our bMEC model, we first stimulated PS cells with genetically modified S. aureus strains lacking (protein A, wall teichoic acid (WTA) synthesis) or expressing (capsular polysaccharide (CP) type 5 or type 8) factors expected to affect S. aureus recognition by bMEC. The absence of functional WTA synthesis increased IL-8 release by bMEC in response to bacterial stimulation compared to wildtype. In addition, bMEC released more IL-8 after stimulation with S. aureus expressing CP type 5 compared to CP type 8 or a strain lacking CP expression. Among the S. aureus lineages, isolates belonging to CC133 induced a significantly stronger IL-8 release from bMEC than isolates from the other CCs, and the IL-8 response to CC479 was higher compared to CC151 and CC425. Transcription levels of IL-8, tumor necrosis factor alpha (TNFα), serum amyloid A3 (SAA3), Toll-like receptor (TLR)-2 and nuclear factor κB (NF-κB) in bMEC after bacterial stimulation tended to follow a similar pattern as IL-8 release, but there were no significant differences between the CCs. This study demonstrates a differential activation of bMEC by ruminant-associated CCs of S. aureus, which may have implications for the severity of mastitis during IMI by S. aureus belonging to these lineages. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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27 pages, 2983 KiB

Open AccessArticle

Structural and Functional Dynamics of Staphylococcus aureus Biofilms and Biofilm Matrix Proteins on Different Clinical Materials

by Anna K. Hiltunen, Kirsi Savijoki, Tuula A. Nyman, Ilkka Miettinen, Petri Ihalainen, Jouko Peltonen and Adyary Fallarero

Microorganisms 2019, 7(12), 584; https://doi.org/10.3390/microorganisms7120584 - 20 Nov 2019

Cited by 37 | Viewed by 4926

Abstract

Medical device-associated staphylococcal infections are a common and challenging problem. However, detailed knowledge of staphylococcal biofilm dynamics on clinically relevant surfaces is still limited. In the present study, biofilm formation of the Staphylococcus aureus ATCC 25923 strain was studied on clinically relevant materials—borosilicate [...] Read more.

Medical device-associated staphylococcal infections are a common and challenging problem. However, detailed knowledge of staphylococcal biofilm dynamics on clinically relevant surfaces is still limited. In the present study, biofilm formation of the Staphylococcus aureus ATCC 25923 strain was studied on clinically relevant materials—borosilicate glass, plexiglass, hydroxyapatite, titanium and polystyrene—at 18, 42 and 66 h. Materials with the highest surface roughness and porosity (hydroxyapatite and plexiglass) did not promote biofilm formation as efficiently as some other selected materials. Matrix-associated poly-N-acetyl-β-(1-6)-glucosamine (PNAG) was considered important in young (18 h) biofilms, whereas proteins appeared to play a more important role at later stages of biofilm development. A total of 460 proteins were identified from biofilm matrices formed on the indicated materials and time points—from which, 66 proteins were proposed to form the core surfaceome. At 18 h, the appearance of several r-proteins and glycolytic adhesive moonlighters, possibly via an autolysin (AtlA)-mediated release, was demonstrated in all materials, whereas classical surface adhesins, resistance- and virulence-associated proteins displayed greater variation in their abundances depending on the used material. Hydroxyapatite-associated biofilms were more susceptible to antibiotics than biofilms formed on titanium, but no clear correlation between the tolerance and biofilm age was observed. Thus, other factors, possibly the adhesive moonlighters, could have contributed to the observed chemotolerant phenotype. In addition, a protein-dependent matrix network was observed to be already well-established at the 18 h time point. To the best of our knowledge, this is among the first studies shedding light into matrix-associated surfaceomes of S. aureus biofilms grown on different clinically relevant materials and at different time points. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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14 pages, 1348 KiB

Open AccessArticle

Staphylococcus arlettae Genomics: Novel Insights on Candidate Antibiotic Resistance and Virulence Genes in an Emerging Opportunistic Pathogen

by Anna Lavecchia, Matteo Chiara, Caterina De Virgilio, Caterina Manzari, Rosa Monno, Armando De Carlo, Carlo Pazzani, David Horner, Graziano Pesole and Antonio Placido

Microorganisms 2019, 7(11), 580; https://doi.org/10.3390/microorganisms7110580 - 19 Nov 2019

Cited by 12 | Viewed by 5513

Abstract

Coagulase Negative Staphylococci (CoNS) are becoming increasingly recognized as an important cause of human and animal infections. Notwithstanding their clinical relevance, annotation of genes potentially involved in pathogenicity and/or antibiotic resistance in the CoNS species Staphylococcus arlettae (SAR) is currently very limited. In [...] Read more.

Coagulase Negative Staphylococci (CoNS) are becoming increasingly recognized as an important cause of human and animal infections. Notwithstanding their clinical relevance, annotation of genes potentially involved in pathogenicity and/or antibiotic resistance in the CoNS species Staphylococcus arlettae (SAR) is currently very limited. In the current work we describe the genome of a novel methicillin resistant isolate of SAR, which we named Bari, and present a comprehensive analysis of predicted antibiotic resistance profiles and virulence determinants for all the 22 currently available SAR genomes. By comparing predicted antibiotic resistance and virulence-associated genes with those obtained from a manual selection of 148 bacterial strains belonging to 14 different species of staphylococci and to two “outgroup” species, Bacillus subtilis (BS) and Macrococcus caseoliticus (MC), we derived some interesting observations concerning the types and number of antibiotic resistance-related and virulence-like genes in SAR. Interestingly, almost 50% of the putative antibiotic resistance determinants identified in this work, which include the clinically relevant mec, van, and cls genes, were shared among all the SAR strains herein considered (Bari included). Moreover, comparison of predicted antibiotic resistance profiles suggest that SAR is closely related to well-known pathogenic Staphylococcus species, such as Staphylococcus aureus (SA) and Staphylococcus epidermidis (SE). A similar analysis of predicted virulence factors, revealed that several genes associated with pathogenesis (including, for example, ica, nuc, and ssp), which are commonly found in the genomes of pathogenic staphylococci such as Staphylococcus haemolyticus (SH) and Staphylococcus saprophyticus (SS), are observed also in the SAR strains for which a genomic sequence is available. All in all, we believe that the analyses presented in the current study, by providing a consistent and comprehensive annotation of virulence and antibiotic resistance-related genes in SAR, can constitute a valuable resource for the study of molecular mechanisms of opportunistic pathogenicity in this species. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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15 pages, 3253 KiB

Open AccessArticle

Cell-Wall Hydrolases as Antimicrobials against Staphylococcus Species: Focus on Sle1

by Aurore Vermassen, Régine Talon, Carine Andant, Christian Provot, Mickaël Desvaux and Sabine Leroy

Microorganisms 2019, 7(11), 559; https://doi.org/10.3390/microorganisms7110559 - 12 Nov 2019

Cited by 10 | Viewed by 2910

Abstract

Some staphylococcal species are opportunistic pathogens of humans and/or animals with Staphylococcus epidermidis as one of the most important. It causes a broad spectrum of diseases in humans and animals. This species is able to form biofilms and has developed antibiotic resistance, which [...] Read more.

Some staphylococcal species are opportunistic pathogens of humans and/or animals with Staphylococcus epidermidis as one of the most important. It causes a broad spectrum of diseases in humans and animals. This species is able to form biofilms and has developed antibiotic resistance, which has motivated research on new antibacterial agents. Cell-wall hydrolases (CWHs) can constitute a potential alternative. Following a hijacking strategy, we inventoried the CWHs of S. epidermidis. The lytic potential of representative CWHs that could be turned against staphylococci was explored by turbidity assays which revealed that cell wall glycosidases were not efficient, while cell wall amidases and cell wall peptidases were able to lyse S. epidermidis. Sle1, which is encoded by chromosomal gene and composed of three anchoring LysM domains and a C-terminal CHAP (cysteine, histidine-dependent amidohydrolase/peptidase) domain, was one of the most active CWHs. The phylogeny of Sle1 revealed seven clusters mostly identified among staphylococci. Sle1 was able to lyse several staphylococcal species, including Staphylococcus aureus, both in planktonic and sessile forms, but not Micrococcus. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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18 pages, 7764 KiB

Open AccessArticle

Characterization of the Three New Kayviruses and Their Lytic Activity Against Multidrug-Resistant Staphylococcus aureus

by Natalia Łubowska, Bartłomiej Grygorcewicz, Katarzyna Kosznik-Kwaśnicka, Agata Zauszkiewicz-Pawlak, Alicja Węgrzyn, Barbara Dołęgowska and Lidia Piechowicz

Microorganisms 2019, 7(10), 471; https://doi.org/10.3390/microorganisms7100471 - 18 Oct 2019

Cited by 30 | Viewed by 4142

Abstract

The development of antimicrobial resistance has become a global concern. One approach to overcome the problem of drug resistance is the application of bacteriophages. This study aimed at characterizing three phages isolated from sewage, which show lytic activity against clinical isolates of multidrug-resistant [...] Read more.

The development of antimicrobial resistance has become a global concern. One approach to overcome the problem of drug resistance is the application of bacteriophages. This study aimed at characterizing three phages isolated from sewage, which show lytic activity against clinical isolates of multidrug-resistant Staphylococcus aureus. Morphology, genetics and biological properties, including host range, adsorption rate, latent time, phage burst size and lysis profiles, were studied in all three phages. As analyzed by transmission electron microscopy (TEM), phages vB_SauM-A, vB_SauM-C, vB_SauM-D have a myovirion morphology. One of the tested phages, vB_SauM-A, has relatively rapid adsorption (86% in 17.5 min), short latent period (25 min) and extremely large burst size (~500 plaque-forming units (PFU) per infected cell). The genomic analysis revealed that vB_SauM-A, vB_SauM-C, vB_SauM-D possess large genomes (vB_SauM-A 139,031 bp, vB_SauM-C 140,086 bp, vB_SauM-D 139,088 bp) with low G+C content (~30.4%) and are very closely related to the phage K (95–97% similarity). The isolated bacteriophages demonstrate broad host range against MDR S. aureus strains, high lytic activity corresponding to strictly virulent life cycle, suggesting their potential to treat S. aureus infections. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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11 pages, 3845 KiB

Open AccessArticle

Staphylococcus xylosus Infection in Rainbow Trout (Oncorhynchus mykiss) As a Primary Pathogenic Cause of Eye Protrusion and Mortality

by Woo Taek Oh, Jin Woo Jun, Sib Sankar Giri, Saekil Yun, Hyoun Joong Kim, Sang Guen Kim, Sang Wha Kim, Se Jin Han, Jun Kwon and Se Chang Park

Microorganisms 2019, 7(9), 330; https://doi.org/10.3390/microorganisms7090330 - 07 Sep 2019

Cited by 16 | Viewed by 4070

Abstract

Staphylococcal infections are extensively investigated in humans owing to the resistance of staphylococci to diverse antibiotics commonly used in hospitals. The resistance mechanism of methicillin-resistant Staphylococcus aureus has garnered the interest of researchers due to its risk to the global public health. Furthermore, [...] Read more.

Staphylococcal infections are extensively investigated in humans owing to the resistance of staphylococci to diverse antibiotics commonly used in hospitals. The resistance mechanism of methicillin-resistant Staphylococcus aureus has garnered the interest of researchers due to its risk to the global public health. Furthermore, the zoonotic potential of staphylococci has led to increased interest in their transmission mechanism via food, livestock, as well as domestic and wild animals. Although fish are globally consumed, there are only few studies on the potential threat of staphylococcal infection in aquatic animals. In this study, we present the first description of Staphylococcus xylosus infection and its pathogenicity in rainbow trout, which resulted in fish mortality and economic losses in trout fisheries. We focused on the pathogenic role of the bacterium and its influence on rainbow trout based on the clinical symptoms in the eyes. Staphylococcus xylosus infection induced exophthalmia and disrupted the primary immune barrier, which increased the possibility of other secondary bacterial infections in fish under poor conditions, resulting in continuous mortality. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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14 pages, 755 KiB

Open AccessArticle

Phylogenetic and Molecular Profile of Staphylococcus aureus Isolated from Bloodstream Infections in Northeast Brazil

by Andrea de S. Monteiro, Bruna L. S. Pinto, Joveliane de M. Monteiro, Rômulo M. Ferreira, Patrícia C. S. Ribeiro, Silvia Y. Bando, Sirlei G. Marques, Luís C. N. Silva, Wallace R. Nunes Neto, Gabriella F. Ferreira, Maria Rosa Q. Bomfim and Afonso G. Abreu

Microorganisms 2019, 7(7), 210; https://doi.org/10.3390/microorganisms7070210 - 22 Jul 2019

Cited by 13 | Viewed by 4261

Abstract

Staphylococcus aureus is a notorious human pathogen associated with serious nosocomial and community-acquired infections, such as pneumonia, meningitis, endocarditis, toxic shock syndrome, and sepsis, among others. The objective of this study was to investigate the molecular profile, antimicrobial resistance, and clonal diversity of [...] Read more.

Staphylococcus aureus is a notorious human pathogen associated with serious nosocomial and community-acquired infections, such as pneumonia, meningitis, endocarditis, toxic shock syndrome, and sepsis, among others. The objective of this study was to investigate the molecular profile, antimicrobial resistance, and clonal diversity of S. aureus isolated from the bloodstream. The determination of the minimum inhibitory concentration (MIC) of the antimicrobial was performed by an automated method. The presence of several virulence and resistance genes was evaluated by PCR. In addition, multilocus sequence typing (MLST) was used to analyze the clonal diversity of S. aureus. A high resistance to oxacillin (78%), clindamycin (78%), erythromycin (70%), ciprofloxacin (61%), and gentamicin (52%) was observed among the isolates. In most of them, the following virulence genes were detected: hlb (83%), ebpS (61%), icaA (57%), fnbpA (17%), and clfA (13%). Only one isolate carried the pvl gene. MLST analysis identified five new sequence types (STs): 5429, 5430, 5431, 5432, and 5433, as well as another seven—ST5, ST97, ST398, ST101, ST30, ST461, and ST2779—among the remaining strains. These seven STs and the four new STs are clustered in four clonal complexes: CC1, CC2, CC7, and CC17. Phylogenetic analysis showed the genetic relationship of the five new ST strains with another 18 strains. Altogether, these analyses indicate the horizontal transfer acquisition of virulence factor genes and multidrug resistance. Full article

(This article belongs to the Special Issue Biology and Pathogenesis of Staphylococcus Infection)

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