title: Species distribution and antimicrobial susceptibility of gram-negative aerobic bacteria in hospitalized cancer patients.
abstract: BACKGROUND
  Nosocomial infections pose significant threats to hospitalized patients, especially the immunocompromised ones, such as cancer patients.
  
  
  METHODS
  This study examined the microbial spectrum of gram-negative bacteria in various infection sites in patients with leukemia and solid tumors. The antimicrobial resistance patterns of the isolated bacteria were studied.
  
  
  RESULTS
  The most frequently isolated gram-negative bacteria were Klebsiella pneumonia (31.2%) followed by Escherichia coli (22.2%). We report the isolation and identification of a number of less-frequent gram negative bacteria (Chromobacterium violacum, Burkholderia cepacia, Kluyvera ascorbata, Stenotrophomonas maltophilia, Yersinia pseudotuberculosis, and Salmonella arizona). Most of the gram-negative isolates from Respiratory Tract Infections (RTI), Gastro-intestinal Tract Infections (GITI), Urinary Tract Infections (UTI), and Bloodstream Infections (BSI) were obtained from leukemic patients. All gram-negative isolates from Skin Infections (SI) were obtained from solid-tumor patients. In both leukemic and solid-tumor patients, gram-negative bacteria causing UTI were mainly Escherichia coli and Klebsiella pneumoniae, while gram-negative bacteria causing RTI were mainly Klebsiella pneumoniae. Escherichia coli was the main gram-negative pathogen causing BSI in solid-tumor patients and GITI in leukemic patients. Isolates of Escherichia coli, Klebsiella, Enterobacter, Pseudomonas, and Acinetobacter species were resistant to most antibiotics tested. There was significant imipenem -resistance in Acinetobacter (40.9%), Pseudomonas (40%), and Enterobacter (22.2%) species, and noticeable imipinem-resistance in Klebsiella (13.9%) and Escherichia coli (8%).
  
  
  CONCLUSIONS
  This is the first study to report the evolution of imipenem-resistant gram-negative strains in Egypt. Mortality rates were higher in cancer patients with nosocomial Pseudomonas infections than any other bacterial infections. Policies restricting antibiotic consumption should be implemented to avoid the evolution of newer generations of antibiotic resistant-pathogens.
authors.affiliation: Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt. hossamking@mailcity.com
authors.forename: Hossam M
authors.initials: HM
authors.lastname: Ashour
authors.forename: Amany
authors.initials: A
authors.lastname: El-Sharif
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D006088:Gram-Negative Aerobic Bacteria / Q000187:drug effects* / Q000302:isolation & purification* / Q000472:pathogenicity; D016905:Gram-Negative Bacterial Infections / Q000150:complications* / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality; D006760:Hospitalization; D006801:Humans; D008826:Microbial Sensitivity Tests; D009369:Neoplasms / Q000150:complications* / Q000382:microbiology* / Q000401:mortality
chemical_list: D000900:Anti-Bacterial Agents