Sandbox Reserved 994: Difference between revisions

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== Background ==

OXA-24 is a member of the carbapenem-hydrolyzing class D β-lactamases (CHDLs) and is expressed as a resistance mechanism by the bacteria ''Acinetobacter baumannii.'' Class D β-lactamases are clinically dangerous because they hydrolyze β-lactam antibiotics such as penicillins, cephalosporins, and carbapenems. Class D β-lactamases are classified as ~~OXA’s~~, which is in reference to their class designation as oxacillinases; however the terminology is somewhat misleading. While they do have very strong affinity for the antibiotic oxacillin<ref name="Leonard">DOI: 10.1021/ar300327a</ref>; the ~~OXA’s~~ have expanded since their discovery to include penillinase, cephalosporinase, and carbapenemase activity in their spectrum. Due to their original designation as oxacillinases, however, the assignment of the prefix OXA has continued to be standard designation.

OXA-24 is a member of the carbapenem-hydrolyzing class D β-lactamases (CHDLs) and is expressed as a resistance mechanism by the bacteria ''Acinetobacter baumannii.'' Class D β-lactamases are clinically dangerous because they hydrolyze β-lactam antibiotics such as penicillins, cephalosporins, and carbapenems. Class D β-lactamases are classified as OXAs, which is in reference to their class designation as oxacillinases; however the terminology is somewhat misleading. While they do have very strong affinity for the antibiotic oxacillin<ref name="Leonard">DOI: 10.1021/ar300327a</ref>; the OXAs have expanded since their discovery to include penillinase, cephalosporinase, and carbapenemase activity in their spectrum. Due to their original designation as oxacillinases, however, the assignment of the prefix OXA has continued to be standard designation.

Bacteria have cell walls which are largely made of a material called peptidoglycan, composed of N-Acetylmuramic acid (NAM) and N-Acetylglucosamine (NAG), which the cell uses to protect against lysis from changing osmotic pressure. These two materials make alternating links of NAM and NAG which are held next to each other by NAM cross links. Without this forming, the bacterial cell wall cannot hold its structure against more hypotonic solutions and the cell will lyse and die. β-lactams are a group of antibiotics that block the NAM cross linking in the bacterial cell wall by “irreversibly binding to the enzymes that cross-link NAM subunits." <ref name="Bauman">Bauman, Robert W. "Controlling Microbial Growth in the Body: Antimicrobial Drugs." In Microbiology with Diseases by Taxonomy, 287-299. 4th ed. Glenetview, IL: Pearson, 2014. </ref> β-lactams are a family of antibiotics that have a four membered ring called a β-lactam ring. To combat this, bacterial cells have developed enzymes called β-lactamases that hydrolyze the bond between the ring’s acyl group and its nitrogen.<ref name="Bauman" />

Sandbox Reserved 994: Difference between revisions

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 == Background ==
-OXA-24 is a member of the carbapenem-hydrolyzing class D β-lactamases (CHDLs) and is expressed as a resistance mechanism by the bacteria ''Acinetobacter baumannii.'' Class D β-lactamases are clinically dangerous because they hydrolyze β-lactam antibiotics such as penicillins, cephalosporins, and carbapenems. Class D β-lactamases are classified as OXA’s, which is in reference to their class designation as oxacillinases; however the terminology is somewhat misleading.  While they do have very strong affinity for the antibiotic oxacillin<ref name="Leonard">DOI: 10.1021/ar300327a</ref>; the OXA’s have expanded since their discovery to include penillinase, cephalosporinase, and carbapenemase activity in their spectrum. Due to their original designation as oxacillinases, however, the assignment of the prefix OXA has continued to be standard designation.
+OXA-24 is a member of the carbapenem-hydrolyzing class D β-lactamases (CHDLs) and is expressed as a resistance mechanism by the bacteria ''Acinetobacter baumannii.'' Class D β-lactamases are clinically dangerous because they hydrolyze β-lactam antibiotics such as penicillins, cephalosporins, and carbapenems. Class D β-lactamases are classified as OXAs, which is in reference to their class designation as oxacillinases; however the terminology is somewhat misleading.  While they do have very strong affinity for the antibiotic oxacillin<ref name="Leonard">DOI: 10.1021/ar300327a</ref>; the OXAs have expanded since their discovery to include penillinase, cephalosporinase, and carbapenemase activity in their spectrum. Due to their original designation as oxacillinases, however, the assignment of the prefix OXA has continued to be standard designation.
 Bacteria have cell walls which are largely made of a material called peptidoglycan, composed of N-Acetylmuramic acid (NAM) and N-Acetylglucosamine (NAG), which the cell uses to protect against lysis from changing osmotic pressure. These two materials make alternating links of NAM and NAG which are held next to each other by NAM cross links. Without this forming, the bacterial cell wall cannot hold its structure against more hypotonic solutions and the cell will lyse and die. β-lactams are a group of antibiotics that block the NAM cross linking in the bacterial cell wall by “irreversibly binding to the enzymes that cross-link NAM subunits." <ref name="Bauman">Bauman, Robert W. "Controlling Microbial Growth in the Body: Antimicrobial Drugs." In Microbiology with Diseases by Taxonomy, 287-299. 4th ed. Glenetview, IL: Pearson, 2014. </ref> β-lactams are a family of antibiotics that have a four membered ring called a β-lactam ring. To combat this, bacterial cells have developed enzymes called β-lactamases that hydrolyze the bond between the ring’s acyl group and its nitrogen.<ref name="Bauman" />