The antimicrobial susceptibility characteristics of Cronobacter sakazakii in comparison to other members of the Enterobacteriaceae family

Abstract

Bacteria displaying antimicrobial resistance pose a significant global healthcare predicament. Studies have reported an association between increases in mortality, duration of hospitalisation, cost of health care and the emergence of multi-drug resistance. This study focused on identifying the antimicrobial susceptibility characteristics of an emerging foodborne pathogen, Cronobacter sakazakii, and comparing these characteristics to other similar bacteria. Two methods were used for this purpose, namely the disc diffusion method for antimicrobial susceptibility testing and the colony biofilm method. Five antibiotics, gentamicin, ampicillin, chloramphenicol, cefpodoxime and nalidixic acid, were used for the disc diffusion tests. Gentamicin and chloramphenicol were utilised in the colony biofilm experiment. It was found that Cronobacter sakazakii could not be distinguished from other members of the genus Cronobacter on the basis of antibiotic susceptibility and had similar characteristics to strains of the species Salmonella typhimurium and Escherichia coli. Significant differences were seen between C.sakazakii and S.typhimurium in the colony biofilm experiment and were presumed to be due to intrinsic differences in the biofilm forming mechanisms of the two species.