Antimicrobial resistance in Haemophilus influenzae from England and Scotland in 1991.
Twenty-two laboratories in England and Scotland sent 2212 clinical isolates of Haemophilus influenzae to The London Hospital Medical College (LHMC) between 1 January and 31 March 1991. After confirmation of identity, the prevalence of resistance was determined and compared with results from previous similar surveys. beta-Lactamase was produced by 8.3% of non-capsulate isolates and 21% of 52 type b isolates; both figures were higher than the 6% and 18% figures recorded, respectively, in 1986. There was an increase in the prevalence of non-beta-lactamase-mediated diminished susceptibility to ampicillin (5.8%) and co-amoxiclav (6.1%) compared with 1986 (4%). Whereas fewer H. influenzae isolates were resistant to tetracycline (1.4%) or chloramphenicol (0.8%), there was an increase in resistance to trimethoprim (6.8%) and to sulphamethoxazole (16.9%) compared with 1986 (4.2% and 3.5% respectively). In addition, 95 isolates (4.3%) were resistant to both of these anti-folate antimicrobials. Six isolates (one type b from CSF) were resistant to all drugs tested, except for co-amoxiclav. Overall, the results demonstrated that changes have occurred in the last decade in England and Scotland, such that H. influenzae isolates are increasingly likely to be resistant to ampicillin, co-amoxiclav and co-trimoxazole.
Powell
M
M
Department of Medical Microbiology, London Hospital Medical College, UK.
Yeo
S F
SF
Seymour
A
A
Yuan
M
M
Williams
J D
JD
Fah
Y S
YS
D002702:Chloramphenicol Resistance; D004352:Drug Resistance, Microbial; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D012141:Respiratory Tract Infections / Q000382:microbiology; D013420:Sulfamethoxazole / Q000494:pharmacology; D013753:Tetracycline Resistance; D014296:Trimethoprim Resistance; D001618:beta-Lactamases / Q000502:physiology
D001618:beta-Lactamases; D013420:Sulfamethoxazole