Hypervirulent Klebsiella pneumoniae (hypermucoviscous and aerobactin positive) infection over 6 years in the elderly in China: antimicrobial resistance patterns, molecular epidemiology and risk factor

Abstract

BackgroundThe definition of hypervirulent Klebsiella pneumoniae (hvKp), traditionally regarded as hypermucoviscosity, is controversial. However, data based on both phenotype (hypermucoviscous) and genetic (aerobactin) criteria are limited.MethodsA retrospective study was conducted in 175 geriatric patients between January 2008 and January 2014. The clinical and molecular data, including antimicrobial susceptibility testing, extended-spectrum-β-lactamase (ESBL) production, virulence gene, and multilocus sequence typing of the hvKp-group (hypermucoviscosity and aerobactin positive) were compared with those of classic K. pneumoniae (cKp) isolates.ResultsOf 175 Kp isolates, 45.7% were hvKp. In pathogenicity, K1, K2, magA, rmpA, and rmpA2 genes were strongly associated with hvKp (P < 0.01). In the hvKp group, invasive infections (P < 0.000), liver abscess (P = 0.008), abdominal infection (P = 0.002) and septic shock (P = 0.035) are significantly higher than cKp group. Patients with better nutritional status were frequently infected with hvKp. However, host inflammatory reaction is most severe in hvKp group. Patients with diabetes (odds ratio [OR] = 2.548) and digestive diseases (OR = 2.196) are more likely to be infected with hvKp. Importantly, the detection of hvKp isolates increased from January 2008 to January 2010, January 2010 to January 2012, and January 2010 to January 2014 (12, 30, and 48 isolates, respectively). Overall, 16.3% of hvKp isolates produced ESBLs and 20.0% were MDR-hvKp. Multivariate analysis implied that infection occurred in the ICU (OR = 5.826) and patients with indwelling stomach tubes (OR = 6.461) are independent risk factors for ESBL-hvKp infection.ConclusionsHvKp, especially ESBL-hvKp and MDR-hvKp, is emerging in the elderly. It is essential to enhance clinical awareness and management of hvKp infections.Electronic supplementary materialThe online version of this article (10.1186/s12941-018-0302-9) contains supplementary material, which is available to authorized users.

Hypervirulent Klebsiella pneumoniae – clinical and molecular perspectives

“…Patients with hvKp tend to be younger, immunocompetent, present with severe disease compared to cKp [30,51] and present from community settings [9,38,51,58]. Diabetes is a significant risk factor for acquiring a hvKp infection as opposed to a cKp infection [58][59][60][61][62], and for developing metastatic complications in patients with a liver abscess [40,63,64]. However, not all studies have consistently found this association [6,51], suggesting the connection between diabetes and hvKp could vary by region or clinical presentation.…”

“…Historically, antimicrobial resistance was rare with only 2% of isolates exhibiting resistance to tested first generation cephalosporins in Taiwan from 1997 to 2005 [6]. However, the prevalence of multidrug-resistant hvKp is increasing, possibly related to the increase in healthcare-associated infections, making this already morbid infection more difficult to treat [9,10,12,55,56,58,60,69]. Carbapenem-resistant infections are the most concerning of the multidrug-resistant hvKp isolates, and the optimal treatment is still unknown.…”

Clinical and Microbiological Prognostic Factors of In-Hospital Mortality Caused by Hypervirulent Klebsiella Pneumoniae Infections: A Retrospective Study in a Tertiary Hospital of Southwestern China

“…A retrospective study was conducted from February 2018 to June 2019 in the First A liated Hospital of Chongqing Medical University, a 3200-bed tertiary teaching hospital. First, a total of 613 consecutive cases of cKP infection were enrolled during the study period, of which 135 were de ned as hvKP with positive for both string test and aerobactin gene, as has been described previously [19]. Second, according to the prognosis of hospitalization, 135 patients with hvKP were divided into survival group and death group to determine the prognostic factors related to in-hospital mortality of hvKP infection (Fig.…”

Novel Target Exploration from Hypothetical Proteins of Klebsiella pneumoniae MGH 78578 Reveals a Protein Involved in Host-Pathogen Interaction

“…Several outbreaks of K. pneumoniae infections have been reported in hospital settings from different countries, including China, Israel, Poland, Italy, Colombia, and the United States (Kaye and Dhar, 2016;Ocampo et al, 2016;Baraniak et al, 2017;Krapp et al, 2018;Sotgiu et al, 2018;Liu and Guo, 2019). Reportedly, K. pneumoniae accounts for ∼12% of all hospital-acquired pneumonia in the world (Ashurst and Dawson, 2019).…”