Investigation of the potential for mutational resistance to XF-73, retapamulin, mupirocin, fusidic acid, daptomycin, and vancomycin in methicillin-resistant Staphylococcus aureus isolates during a 55-passage study.

XF-73 is a dicationic porphyrin drug with rapid Gram-positive antibacterial activity currently undergoing clinical trials for the nasal decolonization of Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus (MRSA). In multistep (55-passage) resistance selection studies in the presence of subinhibitory concentrations of XF-73, retapamulin, mupirocin, fusidic acid, and vancomycin against four Network on Antimicrobial Resistance in Staphylococcus aureus MRSA strains, there was no >4-fold increase in the MIC for XF-73 after 55 passages. In contrast, there was an increase in the MICs for retapamulin (from 0.

In vitro activity of XF-73, a novel antibacterial agent, against antibiotic-sensitive and -resistant Gram-positive and Gram-negative bacterial species.

The antibacterial activity of XF-73, a dicationic porphyrin drug, was investigated against a range of Gram-positive and Gram-negative bacteria with known antibiotic resistance profiles, including resistance to cell wall synthesis, protein synthesis, and DNA and RNA synthesis inhibitors as well as cell membrane-active antibiotics. Antibiotic-sensitive strains for each of the bacterial species tested were also included for comparison purposes. XF-73 was active [minimum inhibitory concentration (MIC) 0.

Antimicrobial susceptibility of community-acquired respiratory tract pathogens in the UK during 2002/3 determined locally and centrally by BSAC methods.

Objectives: To determine the antimicrobial susceptibility of Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae causing community-acquired lower respiratory tract infection in the UK during 2002/2003 and to compare susceptibilities determined locally by disc diffusion with agar dilution MICs determined at a central laboratory.

Methods: H. influenzae, M.

Surveillance of the susceptibility of ocular bacterial pathogens to the fluoroquinolone gatifloxacin and other antimicrobials in Europe during 2001/2002.

Objectives: To determine the identity of European ocular bacterial pathogens and their susceptibility to topical antimicrobial agents.

Methods: Bacterial isolates derived from clinically significant ocular infections were collected from 10 European centres. Bacteria were re-identified and susceptibility to gatifloxacin, ciprofloxacin, ofloxacin, fusidic acid, gentamicin and chloramphenicol was determined using the NCCLS agar incorporation method at a central testing laboratory.