Detection and Analysis of Klebsiella pneumoniae causing Liver Abscess
Background: Compared with “classical” K. pneumoniae, hypervirulent variant of Klebsiella pneumoniae have the ability to cause serious, life-threatening community-acquired infection, including liver abscess, pneumonia, meningitis and endophthalmitis and the ability to metastatically spread. An objective diagnostic test suitable for routine use in the clinical microbiology laboratory is needed.
Methods: A retrospective study was conducted in 240 patients with cultures positive for K. pneumoniae hospitalized in the Chinese PLA General Hospital from May 2013 to August 2014. The clinical and molecular data of the hypervirulent K. pneumoniae (hvKP) causing liver abscess were analyzed.
Results: Among 240 strains of K. pneumoniae, hvKP accounted for 42.5% (102/240), hvKP causing liver abscess were 37 strains, accounting for 36.3% (37/102), patients with diabetes were 11 (11/37, 29.7%), 13 (13/37, 35.1%) patients were diagnosed as fever of unknown origin at first, 7(7/37, 18.9%) patients with tumor, the rest 6 (6/37, 16.2%) patients with postoperative infection or other site infection. Univariate analysis revealed the following risk factors for hvKP causing liver abscess: string test (odds ratio (OR), 11.306[95% confidence interval (CI), 3.579-35.711]), serotype K1 (OR, 3.109[95% CI, 1.338–7.222]) and fever of unknown origin (OR, 6.921[95% CI, 2.503–19.136]). The results detected by multiplex PCR were consistent with single PCR. 102 strains of hvKP were tested the sensitivity to 14-19 drug, 37 strains caused liver abscess were not found with ESBL.
Conclusions: The detection of string test combined with rmpA and aerobactin can better identify hvKP. Patients with liver abscess generally were diabetes, but some patients didn’t have other disease. There is not much difference about the chance to be attacked by hvKP among male and female. ESBL was not detected among the hvKP causing liver abscess. Multiplex PCR assay could detect hvKP quickly.
Yunfang Sun, Hua Wu and Dingxia Shen