aetiology and antimicrobial susceptibility pattern of the significant blood culture isolates from a district general hospital in England

ABSTRACT

To report the prevalence of pathogens causing blood stream infections [BSIs] and antibiotic susceptibility profile of blood culture isolates from district general hospital, southeast of England. This study was conducted at Southend Hospital, UK to provide data on common pathogens of BSIs and their susceptibility profiles. The microbiology laboratory information and hospital information systems and patients note records were retrospectively reviewed to determine the clinical significance of BSI isolates and the susceptibility pattern from August 2006 to July 2007. Blood cultures were processed by BACTEC, a continuous monitoring system and blood culture isolates were identified by standard conventional methods. Disc diffusion method was used for susceptibility testing according to the British Society of Antimicrobial Chemotherapy guidelines. A total of 699 isolates were analysed. Gram positive bacteria as a group were the most common cause of BSIs. Escherichia coli accounted for 18.8% [132 strains] of the total blood culture isolates; followed by Staphylococcus aureus [18.2%, 127 isolates], coagulase negative Staphylococcus [10.9%, 76 isolates], Streptococcus species [9.4%, 66 isolates] and Klebsiella species [6.72%, 47 isolates]. Anaerobes accounted for 3.9% of the total BSIs whilst only 19 Candida species were isolated. Antimicrobial sensitivity results showed that the majority of the Gram negative bacteria were sensitive to imipenem, meropenem, piperacillin/tazobactam and gentamicin while vancomycin showed good activity against Gram positive bacterial isolates. Better understanding of local prevalence of pathogens of BSI and their susceptibility profile can improve the efficiency of the empiric therapy. Active surveillance of pathogens causing BSI and their antimicrobial susceptibility patterns should be continuously practiced in healthcare settings in order to prevent the spread of multiresistant pathogens