Notably, the PFGE genotypes V, VII and VIII isolated
from ICU patients also had the more resistant antibiotype R1 though found in lower numbers. A number of factors including aggressive antibiotic therapy, prolonged hospitalization and the performance of invasive procedures are well documented contributors to the increased risk of infection with nosocomial strains of MDR K. pneumoniae in patients admitted to the ICU [15]. Clearly different antibiotic susceptibility patterns distinguish different strains of ESBL producing K. pneumoniae as shown in the current study. However, antibiotic susceptibility testing has relatively limited utility as a typing system in epidemiologic studies
not only because of phenotypic variation but also because Selleck PF-04929113 antibiotic resistance is under extraordinary selective pressure in contemporary hospitals [14]. The selective pressure from antimicrobial therapy may alter the antimicrobial susceptibility profile of an organism, such that related organisms show different resistance profiles [16]. Graffunder et al [10] found a correlation between the selective pressure of antimicrobial agents identified as risk factors for ESBL producing organisms and the presence of related resistance genes residing on the plasmids [10]. Woodford et al [16] also suggests that antibiotic pressure may have been a factor for initial colonization of patients and the development of further resistance by the organism [16]. The limitations of the study are those attending studies involving GSK3326595 purchase NVP-LDE225 chemical structure retrospective data collection, the disproportionately small number of ESBL producing K. pneumoniae strains from some clinical service areas, the long time period over which the isolates were collected, the lack of surveillance cultures to detect asymptomatic, colonized patients with MDR ESBL producing K. pneumoniae and the limited available epidemiologic data to compare with the PFGE typing results. During the extended
period of study advances in medical technology, changes in patient population, formulary restrictions and changes in standards of practice or infection Endonuclease control measures may affect the results [10]. Conclusions In summary the results showed clonal diversity of MDR ESBL producing K. pneumoniae, elements of its temporal distribution which were suggestive of endemic persistence and dissemination of this organism between patients at this hospital, the extent of which was not fully ascertained. Further studies which investigate the factors which determine the emergence and persistence of ESBL producing K. pneumoniae in Jamaican hospitals and the impact on clinical and economic outcomes at such institutions would be useful. Methods Microbiological Investigations All clinical isolates (n = 66) of MDR K.