Staphylococcus

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Dr. Milad Shaini Shams abadi

Kingdom :BacteriaPhylum: Firmictues

Class: BacilliOrder: Bacillales

Family: StaphylococcaceaeGenus: Staphylococcus

Characteristics

Staphylococcus

S. Afermentans S. aureusS. auricularisS. capitisS. capraeS. carnosusS. cohniiS. epidermidisS. FelisS. haemolyticusS. hominisS. intermediusS. lugdunensis

S. pettenkoferiS. saprophyticusS. schleiferiS. sciuriS. simulansS. vitulusS. warneriS. xylosus

Staphylococcus

Staphylococcus Aureus





|Epidermal keratinocytes constitutively contain stores of pre-made interleukin-1α (IL-1α) during resting conditions, which is rapidly released in response to nonspecific injury, inflammation or infection. b | In keratinocytes, Staphylococcus aureus induces an IL-1α-mediated autocrine signalling loop through IL-1 receptor 1 (IL-1R1), which leads to the rapid and continuous production of neutrophil-attracting chemokines, such as CXC-chemokine ligand 1 (CXCL1), CXCL2 and CXCL8. c | The production of IL-1β during S. aureus cutaneous infections requires two signals. Signal 1 involves the transcription of pro-IL-1β, which is induced by the activation of pattern recognition receptors (PRRs), such as TLR2 (Toll-like receptor 2) and NOD2 (nucleotide-binding oligomerization domain-containing protein 2). Signal 2 involves NLRP3 (NOD-, LRR- and pyrin domain-containing 3) inflammasome activation, which results in caspase 1-mediated cleavage of pro-IL-1β into active IL-1β. NLRP3 inflammasome activation during S. aureus infections has been shown to be triggered by lysozyme-mediated digestion of S. aureus (which releases peptidoglycan, induces the production of reactive oxygen intermediates and promotes phagosome rupture), by the activation of the purinergic receptor P2X7 by ATP (which is released by stressed or damaged cells during an infection) and by pore-forming toxins of S. aureus, such as the α-, β- and γ-haemolysins. IκB, inhibitor of NF-κB; MDP, muramyl dipeptide; NF-κB, nuclear factor-κB.

Health & Medicine

Staphylococcus