Mezlocillin is a broad-spectrum penicillin antibiotic. It is active against both

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...

and some

Gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bact ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

. Unlike most other extended spectrum penicillins, it is excreted by the liver, therefore it is useful for biliary tract infections, such as ascending cholangitis.

Mechanism of action

Like all other

beta-lactam antibiotic β-lactam antibiotics (beta-lactam antibiotics) are antibiotics that contain a beta-lactam ring in their chemical structure. This includes penicillin derivatives (penams), cephalosporins and cephamycins (cephems), monobactams, carbapenems and ...

s, mezlocillin inhibits the third and last stage of bacterial cell wall synthesis by binding to

penicillin binding proteins Penicillin-binding proteins (PBPs) are a group of proteins that are characterized by their affinity for and binding of penicillin. They are a normal constituent of many bacteria; the name just reflects the way by which the protein was discov ...

. This ultimately leads to cell lysis.

Susceptible organisms

Gram-negative

*''

Bacteroides ''Bacteroides'' is a genus of Gram-negative, obligate anaerobic bacteria. ''Bacteroides'' species are non endospore-forming bacilli, and may be either motile or nonmotile, depending on the species. The DNA base composition is 40–48% GC. Unus ...

'' spp., including ''

B. fragilis ''Bacteroides fragilis'' is an anaerobic, Gram-negative, pleomorphic to rod-shaped bacterium. It is part of the normal microbiota of the human colon and is generally commensal, but can cause infection if displaced into the bloodstream or surroun ...

'' *''

Enterobacter ''Enterobacter'' is a genus of common Gram-negative, facultatively anaerobic, rod-shaped, non-spore-forming bacteria of the family Enterobacteriaceae. It is the type genus of the order Enterobacterales. Several strains of these bacteria are ...

'' spp. *''

Escherichia coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Esc ...

'' *''

Haemophilus influenzae ''Haemophilus influenzae'' (formerly called Pfeiffer's bacillus or ''Bacillus influenzae'') is a Gram-negative, non-motile, coccobacillary, facultatively anaerobic, capnophilic pathogenic bacterium of the family Pasteurellaceae. The bacter ...

'' *''

Klebsiella ''Klebsiella'' is a genus of Gram-negative, oxidase-negative, rod-shaped bacteria with a prominent polysaccharide-based capsule. ''Klebsiella'' species are found everywhere in nature. This is thought to be due to distinct sublineages developi ...

'' species *'' Morganella morganii'' *'' Neisseria gonorrhoeae'' *''

Proteus mirabilis ''Proteus mirabilis'' is a Gram-negative, facultatively anaerobic, rod-shaped bacterium. It shows swarming motility and urease activity. ''P. mirabilis'' causes 90% of all ''Proteus'' infections in humans. It is widely distributed in soil and ...

'' *''

Proteus vulgaris ''Proteus vulgaris'' is a rod-shaped, nitrate-reducing, indole-positive and catalase-positive, hydrogen sulfide-producing, Gram-negative bacterium that inhabits the intestinal tracts of humans and animals. It can be found in soil, water, and ...

'' *'' Providencia rettgeri'' *''

Pseudomonas ''Pseudomonas'' is a genus of Gram-negative, Gammaproteobacteria, belonging to the family Pseudomonadaceae and containing 191 described species. The members of the genus demonstrate a great deal of metabolic diversity and consequently are able t ...

'' spp., including '' P. aeruginosa'' *''

Serratia marcescens ''Serratia marcescens'' () is a species of rod-shaped, Gram-negative bacteria in the family Yersiniaceae. It is a facultative anaerobe and an opportunistic pathogen in humans. It was discovered in 1819 by Bartolomeo Bizio in Padua, Italy.Serra ...

Gram-positive

*''

Enterococcus faecalis ''Enterococcus faecalis'' – formerly classified as part of the group D ''Streptococcus'' system – is a Gram-positive, commensal bacterium inhabiting the gastrointestinal tracts of humans. Like other species in the genus ''Enterococcus'', ''E ...

'' *'' Peptococcus'' spp.'' *''

Peptostreptococcus ''Peptostreptococcus'' is a genus of anaerobic, Gram-positive, non-spore forming bacteria. The cells are small, spherical, and can occur in short chains, in pairs or individually. They typically move using cilia. ''Peptostreptococcus'' are slow-g ...

'' spp.''

Synthesis

Mezlocillin can be made in a variety of ways including reaction of

ampicillin Ampicillin is an antibiotic used to prevent and treat a number of bacterial infections, such as respiratory tract infections, urinary tract infections, meningitis, salmonellosis, and endocarditis. It may also be used to prevent group B stre ...

with chlorocarbamate 1 in the presence of triethylamine. Chlorocarbamate 1 itself is made from ethylenediamine by reaction with phosgene to form the cyclic urea followed by monoamide formation with

methanesulfonyl chloride Methanesulfonyl chloride (mesyl chloride) is an organosulfur compound with the formula . Using the organic pseudoelement symbol Ms for the methanesulfonyl (or mesyl) group –, it is frequently abbreviated MsCl in reaction schemes or equations. ...

and then reaction of the other nitrogen atom with phosgene and trimethylsilylchloride. The closely related analogue

azlocillin Azlocillin is an acyl ampicillin antibiotic with an extended spectrum of activity and greater ''in vitro'' potency than the carboxy penicillins. Azlocillin is similar to mezlocillin and piperacillin. It demonstrates antibacterial activity ...

is made in essentially the same manner as mezlocillin. but with omission of the methylation step.

References

External links

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Duke
* * * Penicillins Enantiopure drugs Imidazolidinones {{antibiotic-stub