title: Antimicrobial susceptibility of the pathogens of bacteraemia in the UK and Ireland 2001-2002: the BSAC Bacteraemia Resistance Surveillance Programme.
abstract: OBJECTIVE
  To describe the current patterns of antimicrobial resistance in the major pathogens of bacteraemia in the UK and Ireland, to highlight any unexpected resistance patterns and to act as a reference baseline for future studies.
  
  
  METHODS
  In 2001 and 2002, 5092 blood culture isolates were collected by 29 laboratories distributed across the UK and Ireland. A single central laboratory re-identified the isolates and measured MICs by the BSAC agar dilution method.
  
  
  RESULTS
  Oxacillin resistance was found in 42% of Staphylococcus aureus and 76% of coagulase-negative staphylococci. Streptococci were generally susceptible to beta-lactams, but tetracycline resistance was common (except in Streptococcus pneumoniae) and particularly common among group B isolates (82% resistant). Nine percent of S. pneumoniae had reduced susceptibility to penicillin (MICs 0.12-1 mg/L), but none required >/=2 mg/L for inhibition. High-level gentamicin resistance was seen in 43% of Enterococcus faecalis, often in combination with raised ciprofloxacin MICs (>/=32 mg/L), but these isolates remained susceptible to ampicillin and imipenem. Only linezolid and tigecycline showed in vitro potency against a large proportion of Enterococcus faecium. Vancomycin resistance was restricted to enterococci (20% of E. faecium, 3% of E. faecalis) and a single isolate of coagulase-negative staphylococci (0.2%, MIC of 8 mg/L). Escherichia coli isolates were commonly resistant to amoxicillin (56%) and tetracycline (88%) but remained susceptible to ceftazidime, piperacillin/tazobactam and imipenem. Extended-spectrum beta-lactamases were detected in 2% of E. coli (none in 2001, 3.2% in 2002), 5% of Klebsiella spp. and 8% of Enterobacter spp. Resistance rates of Pseudomonas aeruginosa to ciprofloxacin, ceftazidime, gentamicin, imipenem and piperacillin/tazobactam were between 4% and 7%. Among the newly licensed and developmental agents, there was no resistance to linezolid in Gram-positive organisms. Ertapenem had a wide spectrum, covering Enterobacteriaceae, streptococci and oxacillin-susceptible staphylococci. MICs of tigecycline were low for Gram-positive species and Enterobacteriaceae except Proteeae and Enterobacter spp.
  
  
  CONCLUSIONS
  Antimicrobial resistance among major bloodstream pathogens to those antimicrobials often selected for empirical therapy was relatively uncommon in 2001-2002, usually <10%. An important exception was oxacillin resistance in S. aureus.
authors.affiliation: Department of Medical Microbiology, Southmead Hospital, Bristol BS10 5NB, UK. rosy.reynolds@btinternet.com
authors.forename: Rosy
authors.initials: R
authors.lastname: Reynolds
authors.forename: Nicola
authors.initials: N
authors.lastname: Potz
authors.forename: Melissa
authors.initials: M
authors.lastname: Colman
authors.forename: Andrea
authors.initials: A
authors.lastname: Williams
authors.forename: David
authors.initials: D
authors.lastname: Livermore
authors.forename: Alasdair
authors.initials: A
authors.lastname: MacGowan
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000890:Anti-Infective Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology*; D001419:Bacteria / Q000187:drug effects*; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects; D016983:Enterococcus / Q000187:drug effects; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D007753:Laboratories / Q000592:standards; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods*; D012737:Sex Factors; D013210:Staphylococcus / Q000187:drug effects; D013291:Streptococcus / Q000187:drug effects; D006113:United Kingdom / Q000453:epidemiology; D001618:beta-Lactamases / Q000032:analysis
chemical_list: D000890:Anti-Infective Agents; D001618:beta-Lactamases