Staphylococcus
Staphylococcus is a genus of Gram-positive, spherical bacteria in the family Staphylococcaceae. Cells occur singly, in pairs, tetrads, short chains, and characteristically in irregular, grape-like clusters. Most species are non-motile, non-spore-forming, and facultatively anaerobic.[2]
The name derives from the Ancient Greek words σταφυλή (staphylē), meaning “bunch of grapes”, and κόκκος (kokkos), meaning “berry” or “grain”, referring to the characteristic cellular arrangement. Alexander Ogston first described clustered cocci in pus from a surgical abscess, and Friedrich Julius Rosenbach subsequently established the genus and distinguished S. aureus from the organism now known as S. epidermidis.[3]
The genus contains commensal organisms of the skin and mucous membranes of humans and other animals, as well as opportunistic pathogens.[2] S. aureus can cause community- and healthcare-associated infections, and antibiotic-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA) can cause serious disease.[4]
Taxonomy
[edit]The nomenclature used here follows the List of Prokaryotic names with Standing in Nomenclature (LPSN). The type species is Staphylococcus aureus, and LPSN recognizes 76 species with correct names in the genus.[1]
In 2020, five species were transferred to the newly established genus Mammaliicoccus: M. fleurettii, M. lentus, M. sciuri, M. stepanovicii, and M. vitulinus.[5] LPSN currently treats Mammaliicoccus as a heterotypic synonym of Staphylococcus and therefore retains the corresponding Staphylococcus names, whereas the NCBI taxonomy database and GTDB continue to recognize Mammaliicoccus as a separate genus.[1][6][7]
Phylogeny
[edit]The following phylogenomic tree is a pruned version of the bacterial reference tree from GTDB release R11-RS232, inferred from 120 marker proteins.[8][9][7] It includes named GTDB species clusters whose names are treated as correct by LPSN.[1] Unnamed clusters, letter-suffixed GTDB clusters, and species lacking a corresponding named cluster are not shown.
| 120 marker proteins based GTDB R11-RS232 | |||||||||||||||||||||||||||
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Characteristics and identification
[edit]Staphylococcus cells have a thick peptidoglycan cell wall containing teichoic acids. Most members are catalase-positive and facultatively anaerobic, although physiological characteristics vary among species. Many species also tolerate elevated salt concentrations.[2]
In the laboratory, catalase activity is commonly used to distinguish staphylococci from streptococci and enterococci. Coagulase and other biochemical reactions can then assist with species identification. Closely related species may require molecular methods or MALDI-TOF mass spectrometry for reliable identification.[10]
Coagulase production
[edit]Coagulase activity, the ability to cause plasma clotting, is an important phenotypic characteristic used to distinguish groups of staphylococci. Nine species have conventionally been described as coagulase-positive: S. argenteus, S. aureus, S. coagulans, S. cornubiensis, S. delphini, S. intermedius, S. lutrae, S. pseudintermedius, and S. schweitzeri. S. agnetis, S. chromogenes, and S. hyicus have been described as coagulase-variable.[11]
A genus-wide study found that 13 species coagulated at least one of six tested animal plasmas, including S. condimenti, which had previously been considered coagulase-negative. The observed phenotype varied with the bacterial species, strain, and source of the plasma. Across the genus, activity was associated principally with von Willebrand factor-binding protein, whereas the classical staphylocoagulase gene was restricted to the S. aureus complex.[11]
Species that do not routinely produce coagulase are collectively called coagulase-negative staphylococci (CoNS). This is a phenotypic grouping rather than a formal taxonomic group and includes both commensal and opportunistically pathogenic species.[10]
Genomics and molecular biology
[edit]Complete genome sequences for the methicillin-resistant S. aureus strains N315 and Mu50 revealed chromosomes containing numerous genes associated with virulence and antimicrobial resistance, including genes carried by mobile genetic elements.[12]
Comparative genomic studies have documented extensive variation in accessory genes among staphylococcal strains. Horizontal gene transfer contributes to the distribution of antimicrobial-resistance and virulence genes and also affects genes outside recognized mobile elements.[13]
Ecology and host associations
[edit]
Members of Staphylococcus commonly colonize the skin and mucosal surfaces of mammals and birds. Host associations range from relatively broad to more restricted, and some animal-associated species are also opportunistic pathogens.[14][11]
Staphylococci also occur in foods and environmental habitats.[2] Members of the genus have, for example, been detected in floral nectar microbial communities.[15]
Clinical significance
[edit]Staphylococcus aureus can be carried asymptomatically on the skin or in the nose but can also cause skin and soft-tissue infections, bloodstream infections, pneumonia, endocarditis, osteomyelitis, and infections associated with implanted medical devices.[4][16] Methicillin-resistant strains are collectively known as MRSA. In healthcare settings, the risk of serious infection is increased among patients in intensive care, patients with weakened immune systems, those undergoing certain operations, and those with indwelling medical devices.[4]
Coagulase-negative species are often components of the normal microbiota but can cause opportunistic infections. S. epidermidis is associated particularly with infections of catheters and other implanted devices, S. saprophyticus is a cause of urinary tract infection, and S. lugdunensis can cause invasive disease.[10]
In bloodstream infection, S. aureus virulence factors contribute to tissue adhesion, immune evasion, host-cell injury, inflammation, altered coagulation, and loss of vascular integrity, which can culminate in sepsis and septic shock.[17]
See also
[edit]
References
[edit]- 1 2 3 4 5 "Genus: Staphylococcus". List of Prokaryotic names with Standing in Nomenclature. Leibniz Institute DSMZ. Retrieved 14 August 2026.
- 1 2 3 4 Götz, Friedrich; Bannerman, Tammy; Schleifer, Karl-Heinz (2006). "The genera Staphylococcus and Macrococcus". The Prokaryotes. Vol. 4. Springer. pp. 5–75. doi:10.1007/0-387-30744-3_1. PMC 7120318.
- ↑ Licitra, Giancarlo (2013). "Etymologia: Staphylococcus". Emerging Infectious Diseases. 19 (9): 1553. doi:10.3201/eid1909.et1909.
- 1 2 3 "Staphylococcus aureus basics". Centers for Disease Control and Prevention. 15 April 2024. Retrieved 14 August 2026.
- ↑ Madhaiyan, Munusamy; Wirth, Joseph S.; Saravanan, Venkatakrishnan Sivaraj (2020). "Phylogenomic analyses of the Staphylococcaceae family suggest the reclassification of five species within the genus Staphylococcus as heterotypic synonyms, the promotion of five subspecies to novel species, the taxonomic reassignment of five Staphylococcus species to Mammaliicoccus gen. nov., and the formal assignment of Nosocomiicoccus to the family Staphylococcaceae". International Journal of Systematic and Evolutionary Microbiology. 70 (11): 5926–5936. doi:10.1099/ijsem.0.004498. PMID 33052802.
- ↑ "Taxonomy browser: Mammaliicoccus". NCBI Taxonomy Browser. National Center for Biotechnology Information. Retrieved 14 August 2026.
- 1 2 "bac120_r232.sp_labels.tree". Genome Taxonomy Database. Retrieved 14 August 2026.
- ↑ "Methods". Genome Taxonomy Database. Retrieved 14 August 2026.
- ↑ "Announcing GTDB R11-RS232". GTDB Forum. 15 April 2026. Retrieved 14 August 2026.
- 1 2 3 Becker K, Heilmann C, Peters G (2014). "Coagulase-negative staphylococci". Clinical Microbiology Reviews. 27 (4): 870–926. doi:10.1128/CMR.00109-13. PMC 4187637. PMID 25278577.
- 1 2 3 Pickering, Amy C.; Yebra, Gonzalo; Gong, Xiangyu; et al. (2021). "Evolutionary and functional analysis of coagulase positivity among the staphylococci". mSphere. 6 (4) e00381-21. doi:10.1128/mSphere.00381-21. PMID 34346700.
- ↑ Kuroda, Makoto; Ohta, Toshiko; Uchiyama, Ikuo; et al. (2001). "Whole genome sequencing of meticillin-resistant Staphylococcus aureus". The Lancet. 357 (9264): 1225–1240. doi:10.1016/S0140-6736(00)04403-2. PMID 11418146.
- ↑ Chan CX, Beiko RG, Ragan MA (2011). "Lateral transfer of genes and gene fragments in Staphylococcus extends beyond mobile elements". Journal of Bacteriology. 193 (15): 3964–3977. doi:10.1128/JB.01524-10. PMC 3147504. PMID 21622749.
- ↑ Kloos, Wesley E. (1980). "Natural populations of the genus Staphylococcus". Annual Review of Microbiology. 34: 559–592. doi:10.1146/annurev.mi.34.100180.003015. PMID 7002032.
- ↑ Jacquemyn H, Lenaerts M, Brys R, Willems K, Honnay O, Lievens B (2013). "Among-population variation in microbial community structure in the floral nectar of the bee-pollinated forest herb Pulmonaria officinalis L." PLOS ONE. 8 (3) e56917. Bibcode:2013PLoSO...856917J. doi:10.1371/journal.pone.0056917. PMC 3594240. PMID 23536759.
- ↑ Tong, Steven Y. C.; Davis, Joshua S.; Eichenberger, Emily; Holland, Thomas L.; Fowler, Vance G. (2015). "Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management". Clinical Microbiology Reviews. 28 (3): 603–661. doi:10.1128/CMR.00134-14. PMC 4451395. PMID 26016486.
- ↑ Powers, Michael E.; Wardenburg, Juliane Bubeck (2014). "Igniting the fire: Staphylococcus aureus virulence factors in the pathogenesis of sepsis". PLOS Pathogens. 10 (2) e1003871. doi:10.1371/journal.ppat.1003871. PMC 3923759. PMID 24550724.
External links
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Media related to Staphylococcus at Wikimedia Commons
Data related to Staphylococcus at Wikispecies
