Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 3 complete abstracts (674 words), 9 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
One of the penicillins which is resistant to penicillinase but susceptible to a penicillin-binding protein. It is inactivated by gastric acid so administered by injection.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Penicillin, Dimethoxyphenyl; Dimethoxyphenyl Penicillin; Meticillin; Staphcillin; Methicillin Hydrate, Monosodium Salt; Methicillin Sodium; Methicillin Monohydrate, Monosodium Salt; Metin.
Where it fits in the MeSH classification
- Broader topics
- Penicillins
- See also
- Methicillin Resistance
Related concepts
- Penicillins
- Penicillinase
Research landscape
PubMed indexes 4,447 records tagged with the MeSH heading “Methicillin” (counts retrieved 2026-10-31). 433 of them (9.7%) were published from 2020 onward, and the busiest period so far is through 1999 with 2,584 records.
Reviews account for 216 records (4.9%) and meta-analyses for 13. Randomized controlled trials number 37 (0.8%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 2,584 |
| 2000-2009 | 627 |
| 2010-2019 | 803 |
| 2020 onward | 433 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 216 | 4.9% |
| Meta-analyses | 13 | 0.3% |
| Randomized controlled trials | 37 | 0.8% |
Method: PubMed query "Methicillin"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-31.
Reading the evidence in drugs and chemicals
Studies of a chemical or drug can answer very different questions: what it is and how it behaves in cells and animals, how the body handles it, and whether it changes outcomes in people. Laboratory and animal findings often do not carry over to patients, and observational studies of exposures are confounded by who uses a substance and why. Nothing on this page is a recommendation to use, avoid, start or stop any substance or medicine; talk to a qualified clinician or pharmacist about your own situation. Check the dose, the species, the comparison group and whether a patient-relevant outcome was measured.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Methicillin-resistant Staphylococcus aureus emerged long before the introduction of methicillin into clinical practice | 2017 | Research article Design not recorded in structured metadata | 199 | cc by PMID 28724393 · DOI · PMC5517843 |
| Global analysis of community-associated methicillin-resistant Staphylococcus aureus exoproteins reveals molecules produced in vitro and during infection | 2007 | Research article Design not recorded in structured metadata | 131 | cc by PMID 17217429 · DOI · PMC2064037 |
| Antibacterial activity against β- lactamase producing Methicillin and Ampicillin-resistants Staphylococcus aureus: Fractional Inhibitory Concentration Index (FICI) determination | 2012 | Research article Design not recorded in structured metadata | 84 | cc by PMID 22716026 · DOI · PMC3464800 |
Methicillin-resistant Staphylococcus aureus emerged long before the introduction of methicillin into clinical practice [1]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundThe spread of drug-resistant bacterial pathogens poses a major threat to global health.
- Closing excerpt
- Crucially this highlights how new drugs, introduced to circumvent known resistance mechanisms, can be rendered ineffective by unrecognised adaptations in the bacterial population due to the historic selective landscape created by the widespread use of other antibiotics.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (245 words)
BackgroundThe spread of drug-resistant bacterial pathogens poses a major threat to global health. It is widely recognised that the widespread use of antibiotics has generated selective pressures that have driven the emergence of resistant strains. Methicillin-resistant Staphylococcus aureus (MRSA) was first observed in 1960, less than one year after the introduction of this second generation beta-lactam antibiotic into clinical practice. Epidemiological evidence has always suggested that resistance arose around this period, when the mecA gene encoding methicillin resistance carried on an SCCmec element, was horizontally transferred to an intrinsically sensitive strain of S. aureus.ResultsWhole genome sequencing a collection of the first MRSA isolates allows us to reconstruct the evolutionary history of the archetypal MRSA. We apply Bayesian phylogenetic reconstruction to infer the time point at which this early MRSA lineage arose and when SCCmec was acquired. MRSA emerged in the mid-1940s, following the acquisition of an ancestral type I SCCmec element, some 14 years before the first therapeutic use of methicillin.ConclusionsMethicillin use was not the original driving factor in the evolution of MRSA as previously thought. Rather it was the widespread use of first generation beta-lactams such as penicillin in the years prior to the introduction of methicillin, which selected for S. aureus strains carrying the mecA determinant. Crucially this highlights how new drugs, introduced to circumvent known resistance mechanisms, can be rendered ineffective by unrecognised adaptations in the bacterial population due to the historic selective landscape created by the widespread use of other antibiotics.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 28724393 · DOI · PMC5517843
Global analysis of community-associated methicillin-resistant Staphylococcus aureus exoproteins reveals molecules produced in vitro and during infection [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a threat to human health worldwide.
- Closing excerpt
- We conclude that the exoproteins identified herein likely account in part for the success of CA-MRSA as a human pathogen.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (202 words)
Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a threat to human health worldwide. Although progress has been made, mechanisms of CA-MRSA pathogenesis are poorly understood and a comprehensive analysis of CA-MRSA exoproteins has not been conducted. To address that deficiency, we used proteomics to identify exoproteins made by MW2 (USA400) and LAC (USA300) during growth in vitro. Two hundred and fifty unique exoproteins were identified by 2-dimensional gel electrophoresis coupled with automated direct infusion-tandem mass spectrometry (ADI-MS/MS) analysis. Eleven known virulence-related exoproteins differed in abundance between the strains, including alpha-haemolysin (Hla), collagen adhesin (Cna), staphylokinase (Sak), coagulase (Coa), lipase (Lip), enterotoxin C3 (Sec3), enterotoxin Q (Seq), V8 protease (SspA) and cysteine protease (SspB). Mice infected with MW2 or LAC produced antibodies specific for known or putative virulence factors, such as autolysin (Atl), Cna, Ear, ferritin (Ftn), Lip, 1-phosphatidylinositol phosphodiesterase (Plc), Sak, Sec3 and SspB, indicating the exoproteins are made during infection in vivo. We used confocal microscopy to demonstrate aureolysin (Aur), Hla, SspA and SspB are produced following phagocytosis by human neutrophils, thereby linking exoprotein production in vitro with that during host-pathogen interaction. We conclude that the exoproteins identified herein likely account in part for the success of CA-MRSA as a human pathogen.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 17217429 · DOI · PMC2064037
Antibacterial activity against β- lactamase producing Methicillin and Ampicillin-resistants Staphylococcus aureus: Fractional Inhibitory Concentration Index (FICI) determination [3]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundThe present study reports the antibacterial capacity of alkaloid compounds in combination with Methicillin and Ampicillin-resistants bacteria isolated from clinical samples.
- Closing excerpt
- Moreover, this study demonstrates the potential of this herbaceous as a source of antibacterial agent that could be effectively used for future health care purposes.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (227 words)
BackgroundThe present study reports the antibacterial capacity of alkaloid compounds in combination with Methicillin and Ampicillin-resistants bacteria isolated from clinical samples. The resistance of different bacteria strains to the current antibacterial agents, their toxicity and the cost of the treatment have led to the development of natural products against the bacteria resistant infections when applied in combination with conventional antimicrobial drugs.MethodThe antibacterial assays in this study were performed by using inhibition zone diameters, MIC, MBC methods, the time-kill assay and the Fractional Inhibitory Concentration Index (FICI) determination. On the whole, fifteen Gram-positive bacterial strains (MRSA/ARSA) were used. Negative control was prepared using discs impregnated with 10 % DMSO in water and commercially available Methicillin and Ampicillin from Alkom Laboratories LTD were used as positive reference standards for all bacterial strains.ResultsWe noticed that the highest activities were founded with the combination of alkaloid compounds and conventional antibiotics against all bacteria strains. Then, results showed that after 7 h exposition there was no viable microorganism in the initial inoculums.ConclusionThe results of this study showed that alkaloid compounds in combination with conventional antibiotics (Methicillin, Ampicillin) exhibited antimicrobial effects against microorganisms tested. These results validate the ethno-botanical use of Cienfuegosia digitata Cav. (Malvaceae) in Burkina Faso. Moreover, this study demonstrates the potential of this herbaceous as a source of antibacterial agent that could be effectively used for future health care purposes.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 22716026 · DOI · PMC3464800
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Methicillin-resistant Staphylococcus aureus: an overview of basic and clinical research [4]
- Research article Methicillin-resistant Staphylococcus aureus [5]
- Research article Methicillin-resistant Staphylococcus aureus [6]
- Research article Methicillin resistance in Staphylococcus aureus: mechanisms and modulation [7]
- Research article Methicillin-resistant staphylococci [8]
- Research article Secreted virulence factor comparison between methicillin-resistant and methicillin-sensitive Staphylococcus aureus, and its relevance to atopic dermatitis [9]
References
- Harkins CP, Pichon B, Doumith M, Parkhill J, Westh H, Tomasz A, et al.. Methicillin-resistant Staphylococcus aureus emerged long before the introduction of methicillin into clinical practice. . 2017. PMID 28724393 · DOI · PMC5517843
- Burlak C, Hammer CH, Robinson MA, Whitney AR, McGavin MJ, Kreiswirth BN, et al.. Global analysis of community-associated methicillin-resistant Staphylococcus aureus exoproteins reveals molecules produced in vitro and during infection. . 2007. PMID 17217429 · DOI · PMC2064037
- Konaté K, Mavoungou JF, Lepengué AN, Aworet-Samseny RR, Hilou A, Souza A, et al.. Antibacterial activity against β- lactamase producing Methicillin and Ampicillin-resistants Staphylococcus aureus: Fractional Inhibitory Concentration Index (FICI) determination. . 2012. PMID 22716026 · DOI · PMC3464800
- Turner NA, Sharma-Kuinkel BK, Maskarinec SA, Eichenberger EM, Shah PP, Carugati M, et al.. Methicillin-resistant Staphylococcus aureus: an overview of basic and clinical research. Nat Rev Microbiol. 2019. PMID 30737488 · DOI · PMC6939889
- Lee AS, de Lencastre H, Garau J, Kluytmans J, Malhotra-Kumar S, Peschel A, et al.. Methicillin-resistant Staphylococcus aureus. Nat Rev Dis Primers. 2018. PMID 29849094 · DOI
- Brumfitt W, Hamilton-Miller J. Methicillin-resistant Staphylococcus aureus. N Engl J Med. 1989. PMID 2651925 · DOI
- Stapleton PD, Taylor PW. Methicillin resistance in Staphylococcus aureus: mechanisms and modulation. Sci Prog. 2002. PMID 11969119 · DOI · PMC2065735
- Chambers HF. Methicillin-resistant staphylococci. Clin Microbiol Rev. 1988. PMID 3069195 · DOI · PMC358041
- Schlievert PM, Strandberg KL, Lin YC, Peterson ML, Leung DY. Secreted virulence factor comparison between methicillin-resistant and methicillin-sensitive Staphylococcus aureus, and its relevance to atopic dermatitis. J Allergy Clin Immunol. 2010. PMID 20109735 · DOI · PMC2814367
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-31.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.