Analysis of hypervirulent Klebsiella pneumoniae and classic Klebsiella pneumoniae infections in a Chinese hospital.

AIMS: To evaluate the clinical and genetic virulence characteristics of critically ill patients with hypervirulent Klebsiella pneumoniae (hvKP) and classic KP (cKP) infection. METHODS AND RESULTS: The patients included in this retrospective study (n = 225) were grouped according to their hvKP (n = 114) or cKP (n = 111) status, and their clinical characteristics were analysed and compared. Cox multivariate analysis was conducted to determine the risk factors for hvKP infection. Length of hospital stay, length of intensive care unit stay, duration of mechanical ventilation and 28-day survival rate were similar between the groups. However, the incidence of septic shock was higher in the hvKP group (16.7%) than in the cKP group (8.1%). CONCLUSIONS: There was a high rate of hvKP infection in this population. Compared to patients with cKP infection, those with hvKP infection showed a higher probability of having septic shock; nevertheless, survival and length of hospital stay were similar between the groups. Risk factors for hvKP infection included hospital-acquired infection and renal insufficiency. SIGNIFICANCE AND IMPACT OF THE STUDY: This study presents relevant information on the characteristics of hvKP infection in a Chinese population, and this promotes early diagnosis and supports the view that the prevalence of hvKP is high in China.

Molecular detection of Class 1, 2, and 3 integrons in hypervirulent and classic Klebsiella pneumoniae isolates: A cross-sectional study.

Background and Aims: The "hypervirulent" variant of Klebsiella pneumoniae (hvKp) is an emerging pathogen that cause life-threatening infection. The present study was conducted to identify the prevalence of hvKp and to investigate the presence class 1, 2, and 3 integrons in these isolates. Methods: A cross-sectional study was conducted at three teaching hospitals, Ahvaz, South-west of Iran, from January 1, 2019 to December 31, 2020. Samples were collected from inpatients and included only the first samples collected from each patient. K. pneumoniae strains were isolated from different specimens using biochemical test and confirmed by targeting 16S-23S rDNA internal transcribed spacer. HvKp isolates were recovered using string test and were further characterized by detection virulence-associated genes (rmpA, iucA, and magA). Antibiotic susceptibility patterns of isolates were determined using the disc diffusion method. Isolates were screened for presence the integron genes (intI, intII, and intIII) and repetitive element sequence-based polymerase chain reaction (PCR) performed to determine strain relatedness. SPSS version 22 was used for the data analysis. Results: Seventy-one (77%) of isolates showed multidrug-resistant (MDR) phenotype. HvKP accounted for 14% (13/92) of cKp isolated from blood (46%) and urinary tract infection (38%), and the great majority of them (61.5%; 8/13) exhibited MDR phenotype. Using the PCR assay, 29 of 92 isolates (31.5%) were found to have positive results for the presence of IntI. Three of the IntI-positive strains were hvKP. Class 2 integron was present in 8/92 cKp isolates. Integron Class 2 was found to coexist with Class 1 integron in 3/8 isolates. All integron-positive isolates (IntI and/or IntII) were resistant to at least three different classes of antibiotics and showed MDR phenotype. No Class 3 integrons were detected among the isolates. Conclusion: The results of our study revealed that considering the role of integrons in facilitating the acquisition and dissemination of resistance genes among bacteria, monitoring the emergence of hvKp, emphasizing on the mechanism of antimicrobial resistance, can prevent from the spread of carbapenemase-producing hvKp strains.

Clinical features of hypervirulent Klebsiella pneumoniae bloodstream infection / 中国感染控制杂志

Objective To understand the microbiological and clinical features of bloodstream infection(BSI) with high virulent Klebsiella pneumoniae(hvKP).Methods The strains and clinical data of 159 patients with Klebsiella pneumoniae (K.pneumoniae) BSI at the Second Hospital of Dalian Medical University from April 2013 to March 2016 were collected.Statistical analysis was performed using SPSS 19.0 software.Results 35.22％(56/159)of patients were with hvKP BSI,K1 and K2 serotypes in hvKP BSI accounted for 51.79％ and 26.79％ respectively.The main source of hvKP BSI was liver abscess(n =26,46.43 ％),the classic type of K.pneumoniae (cKP) BSI was primary bacteremia(n =41,39.81 ％).Difference in different types of infection between two groups of patients was statistically significant(x2 =57.782,P＜0.001),89.29 ％ of hvKP BSI was community-associated infection(CAI),and 73.79％ of cKP BSI was healthcare-associated infection(HAI).Difference in underlying diseases between two groups of patients was statistically significant(x2 =36.532,P＜0.001),50.00％ of hvKP BSI patients had diabetes,45.63％ of cKP BSI patients had malignant tumor.Icidence of septic shock in hvKP BSI patients was higher than that of cKP BSI patients(32.14％ vs 8.74％;x2 =14.096,P＜0.001).The proportion of ESBLs-producing of hvKP and cKP were 5.36％ (3/56)and 47.57％ (49/103)respectively,difference was statistically significant(x2 =29.375,P＜0.001).Klebsiella pneumoniae carbapemase(KPC)-producing hvKP was not found.Resistance rates of hvKP to ceftazidime,ceftriaxone,cefepime,aztreonam,gentamicin,levofloxacin,and compound sulfamethoxazole were all lower than cKP(all P＜0.05).Conclusion hvKP BSI is common in CAI,infection sources and underlying diseases are difference from cKP BSI,hvKP BSI is prone to cause septic shock.Both laboratories and clinicians should pay attention to hvKP infection and the change trend of antimicrobial resistance.