title: Effect of ceftazidime and gentamicin on the oropharyngeal and faecal flora of patients with haematological malignancies.
abstract: Thirty-four patients with haematological malignancies were studied to investigate the effect of empirical broad-spectrum antibiotic therapy (ceftazidime and gentamicin) on the gastro-intestinal flora. Twenty-five patients with acute myeloid leukaemia or post-autologous bone-marrow transplantation were given framycetin, nystatin and colistin (Fracon), and two patients with non-Hodgkin's Lymphoma were on co-trimoxazole, as long-term gut prophylaxis. Semi-quantitative microbiology was carried out on oropharyngeal swabs and quantitative microbiology on faecal specimens. The oropharyngeal flora consisted mainly of streptococci, coagulase-negative staphylococci and coryneforms, and was little affected by ceftazidime/gentamicin. A strain of Enterobacter cloacae resistant to ceftazidime and gentamicin colonized one patient, who later developed septicaemia. The faecal flora of patients on Fracon was dominated by enterococci; the few enterobacteria present were eliminated by ceftazidime/gentamicin. The anaerobic flora was absent in 15% of patients; in the remainder, it consisted mainly of Bacteroides spp., and was little affected by ceftazidime/gentamicin. The faecal flora of patients not on Fracon always contained anaerobes, and some strains of enterobacteria persisted throughout antibiotic treatment. None of the patients was colonized by Clostridium difficile or Pseudomonas aeruginosa. Broad-spectrum therapy with ceftazidime and gentamicin appeared to have little effect on the gastro-intestinal flora, except to encourage the overgrowth of enterococci and reduce the numbers of enterobacteria.
authors.affiliation: Department of Medical Microbiology, St. Bartholomew's Hospital, London, UK.
authors.forename: D A
authors.initials: DA
authors.lastname: Murdoch
authors.forename: S
authors.initials: S
authors.lastname: Gibbs
authors.forename: C G
authors.initials: CG
authors.lastname: Price
authors.forename: S
authors.initials: S
authors.lastname: Easmon
authors.forename: J
authors.initials: J
authors.lastname: Franklin
authors.forename: T A
authors.initials: TA
authors.lastname: Lister
authors.forename: S
authors.initials: S
authors.lastname: Tabaqchali
mesh_terms: D002442:Ceftazidime / Q000494:pharmacology*; D003091:Colistin / Q000627:therapeutic use; D004754:Enterobacter / Q000187:drug effects / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology*; D005839:Gentamicins / Q000494:pharmacology*; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy / Q000382:microbiology*; D008228:Lymphoma, Non-Hodgkin / Q000188:drug therapy / Q000382:microbiology*; D009503:Neutropenia / Q000188:drug therapy / Q000382:microbiology*; D009761:Nystatin / Q000627:therapeutic use; D009960:Oropharynx / Q000382:microbiology*; D012307:Risk Factors; D013210:Staphylococcus / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification; D013291:Streptococcus / Q000187:drug effects / Q000302:isolation & purification; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000627:therapeutic use
chemical_list: D005839:Gentamicins; D009761:Nystatin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D002442:Ceftazidime; D003091:Colistin