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Biomedical subjects

L J Piddock

Publications and source records attributed to L J Piddock.

96 records · Page 6Linked to original sources
PubMed1985

The antimicrobial activity of cefpirome, a new cephalosporin.

The activity of the extended spectrum cephalosporin cefpirome (HR 810) was compared with that of other beta-lactams and gentamicin. A total of 524 clinical isolates and strains known to be resistant to certain agents were studied. Against the Enterobacteriaceae, Haemophilus influenzae and Neisseria spp. cefpirome was highly active (MIC90 less than or equal to 0.5 mg/l), generally being as active or slightly more active than ceftazidime and cefotaxime, and 8 to 32 times more active than cefuroxime. Against Pseudomonas aeruginosa cefpirome (MIC90 8 mg/l) was four-fold less active than ceftazidime. Staphylococcus aureus was susceptible to cefpirome (MIC90 2 mg/l) and cefpirome was the only cephalosporin tested with significant activity against Lancefield Group D streptococci. Bacteroides spp. (with the exception of Bact. ureolyticus) were resistant to cefpirome. The compound was bactericidal to all the susceptible strains studied with the exception of Lancefield Group D streptococci. The major target site for cefpirome was PBP 3 and the protein binding was low.

Bacteria↗
PubMed1985

The mode of action of Sch 34343: affinity for the penicillin binding proteins of Escherichia coli K-12 and Bacteroides fragilis.

The competition of the new penem antibiotic, Sch 34343, for the penicillin-binding-proteins (PBPs) of Escherichia coli and Bacteroides fragilis was studied. Sch 34343 caused rounding of cells, and then sphaeroplast formation and lysis in both organisms. The primary target in both organisms was PBP 2, and at higher concentrations PBP 1a and 1b (and 1c in Bact. fragilis). These targets were inhibited at well below therapeutically achievable concentrations. The results indicate that in E. coli and Bact. fragilis, the bactericidal activity of Sch 34343 is related to inhibition of two out of three 'essential' PBPs.

Anti-Bacterial Agents↗
PubMedDate not supplied

Quinolone resistance in Escherichia coli.

Escherichia coli is an important pathogen of animals and humans that causes great financial cost in food production by causing disease in food animals. The quinolones are a class of synthetic antimicrobial agents with excellent activity against Escherichia coli and other Gram-negative bacteria used in human and veterinary medicine. Different quinolones are used to treat various conditions in animals in different parts of the world. All members of this class of drug have the same mode of action: inhibition of topoisomerase enzymes, DNA Gyrase and Topoisomerase IV. Escherichia coli can become resistant to quinolones by altering the target enzymes, reducing permeability of the cell to inhibit their entry, or by actively pumping the drug out of the cell. All these resistance mechanisms can play a role in high-level fluoroquinolone resistance, however target site mutations appear to be most important. As all quinolones act in the same way resistance to one member of the class will also confer decreased susceptibility to all members of the family. Quinolone resistant Escherichia coli in animals have increased in numbers after quinolone introduction in a number of different case studies. The resistance mechanisms in these isolates are the same as those in resistant strains found in humans. Care needs to be taken to ensure that quinolones are used sparingly and appropriately as highly resistant strains of Escherichia coli can be selected and may pass into the food chain. As these drugs are of major therapeutic importance in human medicine, this is a public health concern. More information as to the numbers of quinolone resistant Escherichia coli and the relationship between resistance and quinolone use is needed to allow us to make better informed decisions about when and when not to use quinolones in the treatment of animals.

Animals↗