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Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus

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A special issue of Antibiotics (ISSN 2079-6382). This special issue belongs to the section "Mechanism and Evolution of Antibiotic Resistance".

Deadline for manuscript submissions: closed (31 December 2023) | Viewed by 35944

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Special Issue Editor

Prof. Dr. Kunyan Zhang

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1. Department of Pathology & Laboratory Medicine, University of Calgary, Calgary, AB, Canada
2. Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, AB, Canada
3. Department of Medicine, University of Calgary, Calgary, AB, Canada
4. Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
5. Centre for Antimicrobial Resistance, Alberta Health Services (AHS), Calgary, AB, Canada
Interests: molecular diagnostics of clinical microbiology; microbial evolution and diversity; MRSA molecular epidemiology, virulence and pathogenesis; staphylococcal cassette chromosome mec (SCCmec)
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Dear Colleagues,

Staphylococcus aureus is a gram positive and coagulase positive pathogen, belonging to the family of Staphylococcaceae. It has the capability to acquire resistance to most antibiotics and to collect virulence factors. This ability is further augmented by its constant emergence of new clones. Historically, penicillin-resistant S. aureus emerged in 1942 within two years of introduction of penicillin. Semi-synthetic antibiotic, methicillin, was then developed to substitute for the treament of penicillin-resistant S. aureus. However, methicillin-resistant S. aureus (MRSA) was clinically identified in 1960 shortly after its introduction in 1959. Thereafter, the worldwide outbreaks of MRSA occur in waves. The dissemination of MRSA is marked by the propagation of a number of clones harboring specific genetic backgrounds in different continents. Although most MRSA strains are hospital-acquired originally, community-associated strains (CA-MRSA) are now been increasingly recognised worldwide and are both phenotypically and genotypically different from hospital-associated (HA)-MRSA. The importance of Livestock-associated (LA)-MRSA has also been frequently reported sine the mid of 2000s. Infections due to MRSA, in particular CA-MRSA and LA-MRSA, are associated with more severity and higher mortality rate, compared to infections caused by methicillin-susceptible strains. This special issue seeks manuscript submissions in the latest advances in molecular evolution, epidemiology, characterization and pathogenicity of MRSA, as well as, its emerging trends in antibiotic resistance and control.

Prof. Kunyan Zhang
Guest Editor

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Keywords

Staphylococcus aureus
methicillin-susceptive S. aureus (MSSA)
methicillin-resistant S. aureus (MRSA)
hospital-associated MRSA (HA-MRSA)
community-associated MRSA (CA-MRSA)
livestock-associated MRSA (LA-MRSA)
molecular evolution, epidemiology, characterization and pathogenicity of MRSA
antibiotic resistance
infection prevention and control

Related Special Issue

Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus, 2nd Edition in Antibiotics

Published Papers (13 papers)

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15 pages, 1427 KiB

Open AccessArticle

Methicillin Resistance Elements in the Canine Pathogen Staphylococcus pseudintermedius and Their Association with the Peptide Toxin PSM-mec

by Gordon Y. C. Cheung, Ji Hyun Lee, Ryan Liu, Sara D. Lawhon, Ching Yang and Michael Otto

Antibiotics 2024, 13(2), 130; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics13020130 - 28 Jan 2024

Viewed by 1441

Abstract

Staphylococcus pseudintermedius is a frequent cause of infections in dogs. Infectious isolates of this coagulase-positive staphylococcal species are often methicillin- and multidrug-resistant, which complicates therapy. In staphylococci, methicillin resistance is encoded by determinants found on mobile genetic elements called Staphylococcal Chromosome Cassette mec (SCCmec), which, in addition to methicillin resistance factors, sometimes encode additional genes, such as further resistance factors and, rarely, virulence determinants. In this study, we analyzed SCCmec in a collection of infectious methicillin-resistant S. pseudintermedius (MRSP) isolates from predominant lineages in the United States. We found that several lineages characteristically have specific types of SCCmec elements and Agr types and harbor additional factors in their SCCmec elements that may promote virulence or affect DNA uptake. All isolates had SCCmec-encoded restriction–modification (R-M) systems of types I or II, and sequence types (STs) ST84 and ST64 had one type II and one type I R-M system, although the latter lacked a complete methylation enzyme gene. ST68 isolates also had an SCCmec-encoded CRISPR system. ST71 isolates had a psm-mec gene, which, in all but apparently Agr-dysfunctional isolates, produced a PSM-mec peptide toxin, albeit at relatively small amounts. This study gives detailed insight into the composition of SCCmec elements in infectious isolates of S. pseudintermedius and lays the genetic foundation for further efforts directed at elucidating the contribution of identified accessory SCCmec factors in impacting SCCmec-encoded and thus methicillin resistance-associated virulence and resistance to DNA uptake in this leading canine pathogen. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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16 pages, 3710 KiB

Open AccessArticle

The Role of Prophage ϕSa3 in the Adaption of Staphylococcus aureus ST398 Sublineages from Human to Animal Hosts

by Habib Dastmalchi Saei, Jo-Ann McClure, Ayesha Kashif, Sidong Chen, John M. Conly and Kunyan Zhang

Antibiotics 2024, 13(2), 112; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics13020112 - 23 Jan 2024

Viewed by 893

Abstract

Staphylococcus aureus sequence type (ST) 398 is a lineage affecting both humans and livestock worldwide. However, the mechanisms underlying its clonal evolution are still not clearly elucidated. We applied whole-genome sequencing (WGS) typing to 45 S. aureus strains from China and Canada between 2005 and 2014, in order to gain insight into their evolutionary pathway. Based on WGS phylogenetic analysis, 42 isolates were assigned to the human-associated clade (I/II-GOI) and 3 isolates to livestock-associated clade (IIa). Phylogeny of ϕSa3 sequences revealed five phage groups (Groups 1–5), with Group 1 carrying ϕSa3-Group 1 (ϕSa3-G1), Group 2 carrying ϕSa3-G2, Group 3 carrying ϕSa3-G3, Group 4 carrying ϕSa3-G4 and Group 5 lacking ϕSa3. ϕSa3-G1 was only found in strains that accounted for the most ancestral human clade I, while ϕSa3-G2, ϕSa3-G3 and ϕSa3-G4 were found restricted to sublineages within clade II-GOI. Some isolates of clade II-GOI were also found to be ϕSa3-negative or resistant to methicillin which are unusual characteristics for human-adapted isolates. This study demonstrated a strong association between phylogenetic grouping and phage type, suggesting an important role of ϕSa3 prophage in the evolution of human-adapted ST398 subclones. In addition, our results suggest that this subclone slowly began to adapt to animal hosts by losing ϕSa3 and acquiring methicillin resistance, which was observed in some strains of human-associated clade II-GOI, an intermediate human to livestock transmission clade. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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11 pages, 1035 KiB

Open AccessArticle

Comparing the Phylogenetic Distribution of Multilocus Sequence Typing, Staphylococcal Protein A, and Staphylococcal Cassette Chromosome Mec Types in Methicillin-Resistant Staphylococcus Aureus (MRSA) in Korea from 1994 to 2020

by You-Jin Hwang

Antibiotics 2023, 12(9), 1397; https://doi.org/10.3390/antibiotics12091397 - 01 Sep 2023

Viewed by 828

Abstract

Staphylococcus aureus (S. aureus) bacteremia is one of the most frequent and severe bacterial infections worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is a serious human pathogen that can cause a wide variety of infections. Comparative genetic analyses have shown that despite the existence of a vast number of genotypes, genotypes are restricted to certain geographical locations. By comparing multilocus sequence typing (MLST) and SCCmec types from 1994 to 2020, the present study intended to discover which genotype genes were related to MRSA infections. MLST, Staphylococcus aureus protein A (spa), and SCCmec typings were performed to determine their relationship during those years. Results revealed that MRSA isolates in the Republic of Korea were distributed among all major staphylococcal cassette chromosome mec (SCCmec) types. The majority of SCCmec isolates belonged to SCCmec type II and type IV. The majority of MLST had the sequence type (ST) 72, 239, 8, or 188. By contrast, minorities belonged to ST22 (SCCmec IV), ST772 (SCCmec V), and ST672 (SCCmec V) genotypes. The SCCmec type was determined for various types. The spa type was dispersed, seemingly regardless of its multidrug resistance property. The MLST type was found to be similar to the existing typical type. These results showed some correlations between resistance characteristics and types according to the characteristics of the MLST types distributed, compared to previous papers. Reports on genotype distribution of MLST and SCCmec types in MRSA are rare. These results show a clear distribution of MLST and SCCmec types of MRSA from 1994 to 2020 in the Republic of Korea. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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29 pages, 5432 KiB

Open AccessArticle

The Plasmidomic Landscape of Clinical Methicillin-Resistant Staphylococcus aureus Isolates from Malaysia

by Esra’a I. Al-Trad, Ching Hoong Chew, Ainal Mardziah Che Hamzah, Zarizal Suhaili, Nor Iza A. Rahman, Salwani Ismail, Suat Moi Puah, Kek Heng Chua, Stephen M. Kwong and Chew Chieng Yeo

Antibiotics 2023, 12(4), 733; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics12040733 - 09 Apr 2023

Cited by 1 | Viewed by 2212

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a priority nosocomial pathogen with plasmids playing a crucial role in its genetic adaptability, particularly in the acquisition and spread of antimicrobial resistance. In this study, the genome sequences of 79 MSRA clinical isolates from Terengganu, Malaysia, (obtained between 2016 and 2020) along with an additional 15 Malaysian MRSA genomes from GenBank were analyzed for their plasmid content. The majority (90%, 85/94) of the Malaysian MRSA isolates harbored 1–4 plasmids each. In total, 189 plasmid sequences were identified ranging in size from 2.3 kb to ca. 58 kb, spanning all seven distinctive plasmid replication initiator (replicase) types. Resistance genes (either to antimicrobials, heavy metals, and/or biocides) were found in 74% (140/189) of these plasmids. Small plasmids (<5 kb) were predominant (63.5%, 120/189) with a RepL replicase plasmid harboring the ermC gene that confers resistance to macrolides, lincosamides, and streptogramin B (MLS_B) identified in 63 MRSA isolates. A low carriage of conjugative plasmids was observed (n = 2), but the majority (64.5%, 122/189) of the non-conjugative plasmids have mobilizable potential. The results obtained enabled us to gain a rare view of the plasmidomic landscape of Malaysian MRSA isolates and reinforces their importance in the evolution of this pathogen. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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11 pages, 2035 KiB

Open AccessArticle

Genomics Insight into cfr-Mediated Linezolid-Resistant LA-MRSA in Italian Pig Holdings

by Manuela Iurescia, Elena Lavinia Diaconu, Patricia Alba, Fabiola Feltrin, Carmela Buccella, Roberta Onorati, Angelo Giacomi, Andrea Caprioli, Alessia Franco, Antonio Battisti and Virginia Carfora

Antibiotics 2023, 12(3), 530; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics12030530 - 07 Mar 2023

Cited by 2 | Viewed by 1605

Abstract

The cfr genes encode for a 23S rRNA methyltransferase, conferring a multiresistance phenotype to phenicol, lincosamide, oxazolidinone, pleuromutilin, and streptogramin A antibiotics. These genes have been described in staphylococci, including methicillin-resistant Staphylococcus aureus (MRSA). In this study, we retrospectively performed an in-depth genomic characterisation of three cfr-positive, multidrug-resistant (MDR) livestock-associated (LA) MRSA clonal complexes (CCs) 1 and 398 detected in different Italian pig holdings (2008–2011) during population studies on Italian livestock (2008–2014). We used a combined Illumina and Oxford Nanopore Technologies (ONT) whole genome sequencing (WGS) approach on two isolates (the 2008 CC1 and the 2010 CC398 isolates, but not the 2011 CC1 isolate). Interestingly, the three isolates presented different cfr variants, with only one displaying a linezolid-resistant phenotype. In isolate 2008 CC1, the cfr gene was identified within a Tn558 composite transposon-like structure flanked by IS elements located on a novel 44,826 bp plasmid. This represents the first report of CC1 LA-MRSA harbouring the cfr gene in its functional variant. Differently, cfr was chromosomally located in isolate 2010 CC398. Our findings have significant public health implications, confirm the need for the continuous genomic surveillance of cfr-positive zoonotic LA-MRSA, and backdate cfr presence in LA-MRSA from Italian pigs to at least 2008. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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16 pages, 2440 KiB

Open AccessArticle

Study of SarA by DNA Affinity Capture Assay (DACA) Employing Three Promoters of Key Virulence and Resistance Genes in Methicillin-Resistant Staphylococcus aureus

by Byungchan Kim, Hong-Ju Lee, Sung-Hyun Jo, Min-Gyu Kim, Yeonhee Lee, Wonsik Lee, Wooseong Kim, Hwang-Soo Joo, Yun-Gon Kim, Jae-Seok Kim and Yung-Hun Yang

Antibiotics 2022, 11(12), 1714; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics11121714 - 28 Nov 2022

Cited by 3 | Viewed by 2178

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA), one of the most well-known human pathogens, houses many virulence factors and regulatory proteins that confer resistance to diverse antibiotics. Although they have been investigated intensively, the correlations among virulence factors, regulatory proteins and antibiotic resistance are still elusive. We aimed to identify the most significant global MRSA regulator by concurrently analyzing protein-binding and several promoters under same conditions and at the same time point. DNA affinity capture assay (DACA) was performed with the promoters of mecA, sarA, and sarR, all of which significantly impact survival of MRSA. Here, we show that SarA protein binds to all three promoters. Consistent with the previous reports, ΔsarA mutant exhibited weakened antibiotic resistance to oxacillin and reduced biofilm formation. Additionally, production and activity of many virulence factors such as phenol-soluble modulins (PSM), α-hemolysin, motility, staphyloxanthin, and other related proteins were decreased. Comparing the sequence of SarA with that of clinical strains of various lineages showed that all sequences were highly conserved, in contrast to that observed for AgrA, another major regulator of virulence and resistance in MRSA. We have demonstrated that SarA regulates antibiotic resistance and the expression of various virulence factors. Our results warrant that SarA could be a leading target for developing therapeutic agents against MRSA infections. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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13 pages, 3327 KiB

Open AccessArticle

Emergence of Cfr-Mediated Linezolid Resistance among Livestock-Associated Methicillin-Resistant Staphylococcus aureus (LA-MRSA) from Healthy Pigs in Portugal

by Célia Leão, Lurdes Clemente, Maria Cara d’Anjo, Teresa Albuquerque and Ana Amaro

Antibiotics 2022, 11(10), 1439; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics11101439 - 19 Oct 2022

Cited by 9 | Viewed by 1706

Abstract

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) ST398 is mainly found in Europe and North America, colonizing the nasal cavity of pigs. This study characterized the MRSA isolates recovered from pig nasal swabs (n = 171) by evaluating the antimicrobial susceptibility profile by broth microdilution and characterizing the genetic lineages by spa-typing. Three linezolid-resistant isolates were subjected to Whole-Genome Sequencing (WGS). All strains harbored the mecA gene and were resistant to tetracycline and susceptible to vancomycin. A high frequency of multidrug resistance (97.6%) was evidenced, with 55 different multidrug resistance profiles identified. The MRSA strains were found to belong to 17 spa-types, three being novel. The linezolid-resistant strains appeared to belong to the ST398 type, spa-type t011, and SCCmec_type_Vc and to harbor the cfr, fexA, blaZ, mecA, tetM, and tetK genes. The cfr gene was predicted to be carried in the plasmid, flanked by ISSau9 and the transposon TnpR. MRSA from Portuguese fattening pigs present a high diversity of genetic lineages. The presence of cfr-positive LA-MRSA may represent a risk of transmission to humans, mainly to those in contact with livestock. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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11 pages, 476 KiB

Open AccessArticle

Expression of Staphylococcal Virulence Genes In Situ in Human Skin and Soft Tissue Infections

by Michael S. Pulia, Jennifer Anderson, Zhan Ye, Noha S. Elsayed, Thao Le, Jacob Patitucci, Krishna Ganta, Matthew Hall, Vineet K. Singh and Sanjay K. Shukla

Antibiotics 2022, 11(4), 527; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics11040527 - 14 Apr 2022

Cited by 3 | Viewed by 1929

Abstract

Background: Staphylococcus aureus, the most common pathogen in skin and soft tissue infections (SSTI), harbors many well-characterized virulence genes. However, the expression of many of them in SSTIs is unknown. In this study, S. aureus virulence genes expressed in SSTI were investigated. Methods: Fifty-three subjects presenting to the outpatient’s care and emergency departments with a purulent SSTI at two medical centers in Wisconsin, USA, were enrolled in the study. Total mRNA was extracted from the purulent or swab materials, made into cDNA and sequenced on MiSeq platform. The relative cDNA counts to gmk and identifications of the transcripts were carried out with respect to USA300 reference genome and using SAMTOOLS v.1.3 and BWA, respectively. Result: A significantly higher cDNA count was observed for many of the virulence and regulatory gene transcripts in the pus samples compared to the swab samples relative to the cDNA counts for gmk, a housekeeping gene. They were for lukS-PV (18.6 vs. 14.2), isaA (13.4 vs. 8.5), ssaA (4.8 vs. 3.1), hlgC (1.4 vs. 1.33), atl (17.7 vs. 8.33), clfA (3.9 vs. 0.83), eno (6.04 vs. 3.16), fnbA (5.93 vs. 0.33), saeS (6.3 vs. 1.33), saeR (5.4 vs. 3.33) and agrC (5.6 vs. 1.5). Conclusions: A relative increase in the transcripts of several toxins, adhesion and regulatory genes with respect to a gmk in purulent materials suggests their role in situ during SSTIs, perhaps in an orchestrated manner. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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16 pages, 1318 KiB

Open AccessFeature PaperArticle

Methicillin-Resistant Staphylococcus aureus from Peninsular Malaysian Animal Handlers: Molecular Profile, Antimicrobial Resistance, Immune Evasion Cluster and Genotypic Categorization

by Minhian Chai, Muhammad Zikree Sukiman, Amirah Huda Kamarun Baharin, Insyirah Ramlan, Lennard Zhunhoong Lai, Yeewen Liew, Pavitra Malayandy, Noor Muzamil Mohamad, Siewshean Choong, Siti Mariam Zainal Ariffin and Mohd Faizal Ghazali

Antibiotics 2022, 11(1), 103; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics11010103 - 14 Jan 2022

Cited by 5 | Viewed by 2702

Abstract

Staphylococcus aureus (S. aureus) infections, particularly methicillin-resistant Staphylococcus aureus (MRSA) in humans and animals, have become a significant concern globally. The present study aimed to determine the prevalence and antibiogram of S. aureus isolated from animal handlers in Peninsular Malaysia. Furthermore, the genotypic characteristics of S. aureus isolates were also investigated. Nasal and oral swab samples were collected from 423 animal handlers in Peninsular Malaysia. The antibiogram profiles of S. aureus against 18 antibiotics were established using a Kirby–Bauer test. The genotypic profile of S. aureus, including the presence of antimicrobial resistance (AMR), virulence genes and spa genotypes, was investigated using molecular techniques. The overall carriage rate of S. aureus, MRSA and MDRSA was 30.5%, 1.2% and 19.4%, respectively. S. aureus was highly resistant against penicillin (72.3%) and amoxicillin (52.3%). Meanwhile, gentamicin and linezolid were fully effective against all the isolated S. aureus from animal handlers. It was observed that animal handlers with close exposure to poultry were more likely to carry S. aureus that is resistant to tetracycline and erythromycin. S. aureus isolates harboured tetracycline resistance (tetK, tetL and tetM), erythromycin resistance (ermA, ermB, ermC and msrA) and immune evasion cluster (IEC) genes (scn, chp, sak, sea and sep). Seventeen different spa types were detected among the 30 isolates of MDRSA, with t189 (16.7%) and t4171 (16.7%) being the predominant spa type, suggesting wide genetic diversity of the MDRSA isolates. The present study demonstrated the prevalence of S. aureus strains, including MRSA and MDRSA with various antimicrobial resistance and genetic profiles from animal handlers in Peninsular Malaysia. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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14 pages, 2274 KiB

Open AccessArticle

Genomic Investigation of Methicillin-Resistant Staphylococcus aureus ST113 Strains Isolated from Tertiary Care Hospitals in Pakistan

by Nimat Ullah, Hamza Arshad Dar, Kanwal Naz, Saadia Andleeb, Abdur Rahman, Muhammad Tariq Saeed, Fazal Hanan, Taeok Bae and Amjad Ali

Antibiotics 2021, 10(9), 1121; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics10091121 - 17 Sep 2021

Cited by 6 | Viewed by 3456

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a multi-drug resistant and opportunistic pathogen. The emergence of new clones of MRSA in both healthcare settings and the community warrants serious attention and epidemiological surveillance. However, epidemiological data of MRSA isolates from Pakistan are limited. We performed a whole-genome-based comparative analysis of two (P10 and R46) MRSA strains isolated from two provinces of Pakistan to understand the genetic diversity, sequence type (ST), and distribution of virulence and antibiotic-resistance genes. The strains belong to ST113 and harbor the SCCmec type IV encoding mecA gene. Both the strains contain two plasmids, and three and two complete prophage sequences are present in P10 and R46, respectively. The specific antibiotic resistance determinants in P10 include two aminoglycoside-resistance genes, aph(3’)-IIIa and aad(6), a streptothrin-resistance gene sat-4, a tetracycline-resistance gene tet(K), a mupirocin-resistance gene mupA, a point mutation in fusA conferring resistance to fusidic acid, and in strain R46 a specific plasmid associated gene ant(4’)-Ib. The strains harbor many virulence factors common to MRSA. However, no Panton-Valentine leucocidin (lukF-PV/lukS-PV) or toxic shock syndrome toxin (tsst) genes were detected in any of the genomes. The phylogenetic relationship of P10 and R46 with other prevailing MRSA strains suggests that ST113 strains are closely related to ST8 strains and ST113 strains are a single-locus variant of ST8. These findings provide important information concerning the emerging MRSA clone ST113 in Pakistan and the sequenced strains can be used as reference strains for the comparative genomic analysis of other MRSA strains in Pakistan and ST113 strains globally. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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Review

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14 pages, 1702 KiB

Open AccessReview

Staphylococcal Infections and Neonatal Skin: Data from Literature and Suggestions for the Clinical Management from Four Challenging Patients

by Domenico Umberto De Rose, Flaminia Pugnaloni, Ludovica Martini, Iliana Bersani, Maria Paola Ronchetti, Andrea Diociaiuti, May El Hachem, Andrea Dotta and Cinzia Auriti

Antibiotics 2023, 12(4), 632; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics12040632 - 23 Mar 2023

Viewed by 4183

Abstract

Staphylococcal infections in neonates might be associated with skin blistering since early antibiotic therapy has been shown to limit infection spread and positively influence outcomes; therefore, neonatologists should be aware of these conditions. This review examines the recent literature on the management of Staphylococcal infections that involve neonatal skin, discussing the most appropriate clinical approach to four cases of neonatal blistering diseases with Staphylococcal infections: a case of Staphylococcal bullous impetigo, a case of Staphylococcal scalded skin syndrome (SSSS), a case of epidermolysis bullosa with overlapping Staphylococcal infection, and a case of burns with overlapping Staphylococcal infection. In treating Staphylococcal infections involving skin in neonates, the presence or absence of systemic symptoms should be considered. In the lack of evidence-based guidelines in this age category, treatment should be individualized according to several factors including the extension of the disease or further skin comorbidities (such as skin fragility), with a multidisciplinary approach. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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12 pages, 1627 KiB

Open AccessReview

Current Status of Staphylococcal Cassette Chromosome mec (SCCmec)

by Yuki Uehara

Antibiotics 2022, 11(1), 86; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics11010086 - 11 Jan 2022

Cited by 53 | Viewed by 8219

Abstract

Staphylococcal cassette chromosome mec (SCCmec) typing was established in the 2000s and has been employed as a tool for the molecular epidemiology of methicillin-resistant Staphylococcus aureus, as well as the evolution investigation of Staphylococcus species. Molecular cloning and the conventional sequencing of SCCmec have been adopted to verify the presence and structure of a novel SCCmec type, while convenient PCR-based SCCmec identification methods have been used in practical settings for many years. In addition, whole-genome sequencing has been widely used, and various SCCmec and similar structures have been recently identified in various species. The current status of the SCCmec types, SCCmec subtypes, rules for nomenclature, and multiple methods for identifying SCCmec types and subtypes were summarized in this review, according to the perspective of the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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8 pages, 263 KiB

Open AccessPerspective

Detection of Methicillin-Resistant Staphylococcus aureus Infections Using Molecular Methods

by Fred C. Tenover and Isabella A. Tickler

Antibiotics 2022, 11(2), 239; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics11020239 - 12 Feb 2022

Cited by 5 | Viewed by 2723

Abstract

The application of molecular detection methods for bacterial pathogens has dramatically improved the outcomes of septic patients, including those with methicillin-resistant Staphylococcus aureus (MRSA) infections. Molecular methods can be applied to a variety of clinical specimens including nasal swabs, growth in blood culture bottles, and wounds. While data show that the overall accuracy of molecular tests for MRSA is high, results can be confounded by the presence of multiple staphylococcal species in a specimen, insertions and deletions of DNA in and around the Staphylococcal Cassette Chromosome mec (SCCmec) element, and point mutations in mecA. Herein, we explore the complexities of molecular approaches to MRSA detection and the instances where phenotypic methods should be pursued to resolve discrepancies between genotypic and phenotypic results. Full article

(This article belongs to the Special Issue Molecular Evolution and Pathogenicity of Methicillin-Resistant Staphylococcus aureus)

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