title: Antimicrobial resistance of Gram-negative bacilli isolates from inpatients and outpatients at Yaounde Central Hospital, Cameroon.
abstract: OBJECTIVE
  To determine and compare antimicrobial susceptibility patterns of pathogenic bacteria from inpatients and outpatients at a university teaching hospital in Yaounde, Cameroon.
  
  
  METHODS
  Gram-negative bacilli isolates (n = 522), obtained from a wide range of clinical specimens (urine, pus and blood) from inpatients and outpatients at Yaounde Central Hospital between March 1995 and April 1998, were evaluated for resistance to antibiotics (amoxicillin, amoxicillin/clavulanate, piperacillin, cefazolin, cefoxitin, cefotaxime, ceftazidime, aztreonam, imipenem, gentamicin, tobramicin, ofloxacin and trimethoprim/sulfamethoxazole).
  
  
  RESULTS
  Of the 522 isolates recorded, 80.3% were Enterobacteriaceae. A high incidence of resistance to amoxicillin (85%), piperacillin (75%) and trimethoprim/sulfamethoxazole (71%) was observed. The proportion of antimicrobial-resistant isolates from inpatients was significantly higher than that from outpatients (P < 0.05), except for piperacillin, tobramicin and trimethoprim/sulfamethoxazole. The combinations of antimicrobial and organism showed that the percentage of ceftazidime-resistant Pseudomonas aeruginosa and ceftazidime-resistant Enterobacter cloacae were 26.8% and 24% respectively. The rate of antimicrobial resistance in isolates from inpatients was not significantly higher than that in isolates from outpatients for all the antimicrobial/organism combinations, except for ceftazidime-resistant Escherichia coli, which was exclusively found in isolates from inpatients. Among Enterobacteriaceae, high and low level penicillinase (mostly in E. coli (13.6% and 11% respectively) and Klebsiella spp. (9% and 8% respectively) were the most important beta-lactam resistance phenotypes (31.2% and 23.6%, respectively). Wild type (exclusively observed in E. coli, Proteus mirabilis and Salmonella spp.) and low level penicillinase were higher in outpatient than inpatient isolates (wild type--17.9% vs 10.8% and low level penicillinase--29.4% vs 20.5%, respectively; P < 0.05). However, extended spectrum beta-lactamase strains (Klebsiella spp. (3.5%), E. coli (2.6%), Citrobacter spp. (0.7%), Enterobacter spp. (0.4%) and P. mirabilis (0.2%)) were exclusively recovered from inpatients. Penicillinase and high level cephalosporinase resistance phenotypes were frequently observed in non-fermenter Gram-negative bacilli (46.6% and 29.1% respectively). However, there were no significant differences in penicillinase and cephalosporinase resistance between inpatient and outpatient isolates.
  
  
  CONCLUSIONS
  As the incidence of antimicrobial resistance is substantially higher in isolates from inpatient than outpatient pathogens, more resources should be allocated within the hospital to encourage good antibiotic practices and good hospital hygiene.
authors.affiliation: Laboratory of General Biology, Faculty of Science, University of Yaounde I, P.O. Box 812 Yaounde, Cameroon. jgangoue@yahoo.fr
authors.forename: Joseph Gangoué
authors.initials: JG
authors.lastname: Piéboji
authors.forename: Sinata
authors.initials: S
authors.lastname: Koulla-Shiro
authors.forename: Pierre
authors.initials: P
authors.lastname: Ngassam
authors.forename: Dieudonné
authors.initials: D
authors.lastname: Adiogo
authors.forename: Thomas
authors.initials: T
authors.lastname: Njine
authors.forename: Peter
authors.initials: P
authors.lastname: Ndumbe
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002163:Cameroon; D017714:Community-Acquired Infections / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D004755:Enterobacteriaceae / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology; D006785:Hospitals, University; D006801:Humans; D007297:Inpatients; D008826:Microbial Sensitivity Tests; D010045:Outpatients
chemical_list: D000900:Anti-Bacterial Agents