Multidrug-resistant Klebsiella Pneumoniae Research Articles

Checkboard Antimicrobial Susceptibility Testing of Multidrug Resistant Klebsiella Pneumoniae Isolated from Patients with Ventilator Associated Pneumonia

Checkboard Antimicrobial Susceptibility Testing of Multidrug Resistant Klebsiella Pneumoniae Isolated from Patients with Ventilator Associated Pneumonia

Poor Central Nervous System Penetration of Tigecycline in a Patient with Sepsis and Ventriculitis Caused by Multidrug-Resistant Klebsiella Pneumoniae

Objective: To report the use of tigecycline in a case of ventriculitis and concurrent bacteremia. Case Summary: A 57-year-old African American male with a ruptured brain aneurysm was admitted to the intensive care unit after surgical intervention and external ventricular drainage placement. His hospital course was complicated by myocardial infarction, ventilator-associated pneumonia, ventriculitis, and sepsis, with multidrug-resistant (MDR) Klebsiella pneumoniae isolated from multiple sites, including blood and cerebral spinal fluid (CSF). The patient was treated with high doses of intravenous tigecycline and gentamicin along with intrathecal gentamicin. This combination eradicated infections outside the central nervous system (CNS) within 48 hours, but it took approximately 8 days for the CSF culture to become negative. Timed serum and CSF fluid samples were collected to determine CSF penetration of tigecycline on day 12 of therapy. CSF concentrations obtained 30 minutes after the dose and at the end of the dosing interval remained below the detectable limit of 0.05 μg/mL. Discussion: Although CSF tigecycline concentrations may not represent actual CNS tissue concentrations at the site of infection, the low CSF concentrations observed in our case may be responsible for the slow CSF clearance of infection. It was not clear whether gentamicin therapy alone, administered both intravenously and intrathecally, would have achieved the same outcome and cleared the infection from the CNS in this patient. Conclusions: Until additional clinical data are available, tigecycline should not be used for the management of MDR infections associated with the CNS.

Epidemiology and molecular characterization of nosocomially transmitted multidrug-resistant Klebsiella pneumoniae

Objectives: To describe the epidemiology, antimicrobial susceptibility, genomic profiles, and control of a nosocomial outbreak of multidrug-resistant Klebsiella pneumoniae (MRKP) that occurred in the pediatric oncology unit of the University of Malaya Medical Centre in Kuala Lumpur. Materials and Methods: A prospective epidemiologic and microbiologic study was conducted of MRKP isolated from the blood and wound of a boy with necrotizing fascilities after a 7-day course of ceftazidime and amikacin. In the following 2 weeks, phenotypically similar MRKP were isolated from the blood cultures of four other patients and rectal swabs of another three patients and two liquid soap samples located in the same ward. Results: Antimicrobial profiles demonstrated that all the isolates were resistant to ceftazidime, sensitive to imipenem and ciprofloxacin, and confirmed to be extended-spectrum beta-lactamase producers. Plasmids of varying molecular weights were present in all isolates. In eight of these isolates, which included four from blood, there were common large molecular weight plasmids ranging from 80 kb to 100 kb. Pulsed-field gel electrophoresis analysis using Xbal demonstrated six different DNA profiles, A to F. Profile A was shared by two blood culture isolates and were related by 91%. Profile B was found in one rectal swab isolate and one isolate from liquid soap and were related by 94%. Profile C was shared by one blood isolate and one liquid soap isolate and showed 100% relatedness. Profiles D, E, and F each were demonstrated by one blood isolate and two rectal swab isolates, respectively. These showed only 65% relatedness. Conclusions: The MRKP strains in this outbreak were not clonal in origin. The decline of the outbreak after 4 weeks was attributed to the reemphasis of standard infection control procedures and the implementation of a program that addressed sites of environmental contamination.