Hypervirulent Klebsiella pneumoniae has the characteristics of high virulence and high viscosity, which can cause pneumonia, bacteremia, liver abscess, meningitis and other diseases, and in severe cases, it can be life-threatening. At present, studies on the pathogenic mechanism of hypervirulent Klebsiella pneumoniae showed that siderophore virulence genes play an important role in it. The siderophores closely related to hypervirulent Klebsiella pneumoniae virulence mainly include aerobactin, enterobactin, yersiniabactin and salmochelin. Siderophore-related virulence genes mainly include aer, iucB, iroNB and kfuBC. This article focuses on a brief review of the role of siderophore virulence genes in the pathogenic mechanism of hypervirulent Klebsiella pneumoniae, and aims to guide infection control.
ObjectiveTo retrospectively analyze antibiotic resistance and clinical characteristics of Klebsiella pneumoniae strains for guiding the rational use of antibiotics in the area of the Bai nationality.MethodsThe antibiotic resistance and clinical characteristics of Klebsiella pneumoniae strains were retrospective analyzed, which were isolated from specimens of inpatients in First People’s Hospital of Dali between May 2016 and May 2017.ResultsAmong the 1 342 samples of various kinds of samples, 262 strains of Klebsiella pneumoniae were isolated, with the detection rate of 19.52% (262/1342). Clinical isolated strains were mainly from the new pediatric, intensive care unit, respiratory medicine, pediatrics, and mostly from sputum specimens (78.24%, 205/262). By screening of 22 kinds of antimicrobial agents, all strains had ampicillin resistance (100.00%), while none of these strains had ertapenem resistance. Extended-spectrum β-lactamases (ESBLs) positive strains’ resistance rate was higher than ESBLs negative strains (χ2=261.992, P<0.01). There were 76 drug resistant profiles, most of which were multidrug-resistant bacteria except 116 (44.27%) strains were resistant to ampicillin antibiotics only. And the number of strains in other resistant types ranged from 1 to 16. Only one of 262 strains had amikacin resistance, two of them were resistant to imipenem and meroenan.ConclusionsThere are many multidrug-resistant bacteria in Klebsiella pneumoniae in the population of Bai nationality, and there are no extensively drug resistant bacteria and pandrug-resistant bacteria strains. The strains of carbapene-resistant antibiotics should be worthy of clinical attention.
Objective To investigate the clinical characteristics and bacterial drug resistance of bloodstream infection of gram-negative bacteria, and provide guidance for clinical rational drug use and control of hospital infection. Methods A retrospective analysis was conducted in the patients diagnosed as severe pneumonia with blood culture of gram-negative bacteria from January 2015 to December 2017 in Beijing Anzhen Hospital. Results A total of 60 severe pneumonia patients suffered from bloodstream infection of gram-negative bacteria were recruited including 34 males and 26 females aging from 42 to 89 years and 73.4 years in average. In the 60 patients, 32 cases were infected with Klebsiella pneumonias, 20 cases were infected with Acinetobacter baumanni, and 8 cases were infected with Escherichia coli. The antimicrobial susceptibility testing result of Klebsiella pneumonias showed that the drug susceptibility rate was 100% to tigecycline, and 6.3% to amikacin. Escherichia coli was sensitive to Amikacin, imipenem, ceftazidime and meropenem while resistance to other drugs. The antimicrobial resistance of Acinetobacter baumanni was 28.6% for cefoperazone/sulbactam, and 14.3% for tigecycline. C-reactive protein, procalcitonin and SOFA scores were higher in the patients infected with Acinetobacter baumanni. Neutrophils and blood lactic acid were higher in the patients infected with Klebsiella pneumonias. There were no statistical differences in white blood cell, platelet or motality rate between the patients infected with Acinetobacter baumanni and the patients infected with Klebsiella pneumonias. SOFA scores and blood lactic acid had significantly statistical relevance with prognosis. Conclusion There is a high proportion of drug resistance of Klebsiella pneumoniae and Acinetobacter baumanni in the bloodstream infection of gram-negative bacteria.
Compared to classical Klebsiella pneumoniae, hypervirulent Klebsiella pneumoniae (hvKP) exhibits stronger pathogenicity and a greater ability to evade host immune responses. Infections caused by hvKP typically manifest as more severe diseases with higher mortality rates, thereby increasing the complexity and challenges of clinical treatment. The emergence of carbapenem-resistant hvKP (CR-hvKP) exacerbates this predicament. Although there is still confusion regarding the clinical definition and detection standards for hvKP, this article systematically explains the clinical infection characteristics, identification methods, and mechanisms behind the emergence of CR-hvKP. This can enhance clinical staff’s vigilance towards hvKP infections and offer comprehensive and detailed considerations for the diagnosis and treatment of such strains.
Objective To explore the colonization of Klebsiella pneumoniae in the intensive care unit of our hospital and analyze the risk factors. Methods A total of 226 patients were actively screened in the surgical intensive care unit and neurosurgery intensive care unit from June to December 2020 in the hospital, and their clinical data were retrospectively analyzed. Results Totally, 87 strains of Klebsiella pneumoniae were screened out, 69 strains were carbapenem-resistant Klebsiella pneumoniae (CRKP), and the resistant genotype was mainly KPC genotype (79.6%). The resistance rates of meropenem were 75.0% and 77.4%, respectively. Age and pulmonary infection before admission are risk factors for CRKP colonization, while pulmonary infection before admission is an independent risk factor for CRKP colonization. Conclusions Both the CRKP colonization rate of patients and the rate of resistance to carbapenem antimicrobials are relatively high in the intensive care unit of our hospital. Pulmonary infection before admission is an independent risk factor for CRKP colonization.
Objective To compare the screening ability of modified Hodge test (MHT), modified carbapenem inactivation method (mCIM) and EDTA-carbapenem inactivation method (eCIM) for drug resistance phenotype of carbapenemase-producing Klebsiella pneumoniae. MethodsCarbapenem resistant Klebsiella pneumoniae (CRKP) strains clinically isolated from 5 hospitals in Chengdu between January 2019 and December 2021 were collected, and the carbapenem sensitive Klebsiella pneumoniae (CSKP) strains isolated in the same period were randomly collected. Polymerase chain reaction (PCR) -amplified carbapenem resistance gene as the gold standard, the consistencies between the results of the three phenotypic tests and the results of genetic testing were compared. Results A total of 160 CRKP strains and 120 CSKP strains were isolated. Among the 160 CRKP strains, carbapenem resistance genes were detected in 156 strains, including 105 strains of blaKPC-2, 41 strains of blaNDM-1, 8 strains of blaKPC-19, 1 strain of blaIMP-1, and 1 strain carrying both blaKPC-2 and blaNDM-1. None of the 120 CSKP drug resistance genes were detected. The sensitivity and specificity of carbapenem screening for MHT and mCIM were 73.08% (114/156), 96.67% (116/120), 97.44% (152/156) and 98.33% (118/120), respectively. The sensitivity and specificity of eCIM for screening metalloenzymes were 95.35% (41/43) and 100% (120/120), respectively. Conclusions The sensitivity of MHT to detect carbapenemase is lower than that of the other two methods, and it is easy to produce false negatives when it is used to detect metalloenzymes. The mCIM has high sensitivity and is consistent with the PCR genetic test results. The combined detection of mCIM and eCIM can screen carbapenemases more effectively and distinguish the types of carbapenemases.
Liver transplantation is currently the only effective curative treatment for end-stage liver disease. In recent years, with advancements in liver transplantation surgery and anti-rejection drugs, the incidence of surgical complications and organ rejection has gradually decreased. Conversely, transplant-related infections have increasingly become a major factor affecting the prognosis of transplant recipients. Furthermore, due to the progress in critical life support technologies, the time spent in the donor’s intensive care unit (ICU) has been extended, and post-transplant infections originating from the donor, especially donor-derived infection (DDI), have become one of the primary sources of infection for recipients. Studies have shown that infections in liver transplant recipients are often caused by Gram-negative pathogens, particularly carbapenem-resistant Klebsiella pneumoniae (CRKP), which has now become the leading cause of fatal infections in liver transplant recipients. To reduce the risk of donor-derived infections, it is necessary to strengthen donor screening and evaluation, establish standardized testing processes, and adjust the use strategies of post-transplant anti-infective drugs and immunosuppressants. Monitoring the immune status of recipients is also crucial. Multidisciplinary collaboration and the application of new technologies will be key in future infection prevention and control. To promote the prevention and treatment of CRKP-related donor infections, West China Hospital of Sichuan University, in collaboration with international experiences, has organized relevant experts to develop an expert consensus on the prevention and treatment of CRKP-targeted DDI.
In recent years, with the wide application of carbapenems, the resistance of Enterobacterium to carbapenems has become increasingly high, leading to a large number of carbapenem-resistant Klebsiella pneumoniae (CRKP). These bacteria are often resistant to many different types of antibacterial drugs, including carbapenems, which leads to clinical treatment failure and seriously threatens the life safety of patients. Currently, these bacteria have become an independent risk factor for patients’ death. This article reviews the drug resistance, infection status and influencing factors, and medication therapy of CRKP, in order to facilitate the clinical diagnosis, treatment, and disease process control of CRKP infection, and provide reference for curbing bacterial drug resistance.
ObjectiveTo study the antibacterial activity of ceftazidime/avibactam against carbapenem-resistant Klebaiella pneumoniae (CRKP) in vitro and detect the resistance genes of CRKP, so as to provide reference for the treatment of patients with CRKP infection.MethodsA total of 120 CRKP strains isolated from clinical specimens from May 2014 to November 2017 were collected. The activitis of 11 antimicrobial agents against those CRKP strains were detected by broth microdilution method, and the genes related to resistance to ceftazidime/avibactam were detected by polymerase chain reaction in the 120 CRKP isolates.ResultsThe resistance rate of the 120 CRKP isolates against ceftazidime/avibactam was 16.67% (20/120), which was significantly lower than that against cefotaxime (100.00%), aztreonam (98.33%), ceftazidime (95.83%), cefoperazone/sulbactam (95.83%), meropenem (95.83%), imipenem (95.00%), levofloxacin(92.50%), amikacin (54.17%), minocycline (39.17%), and tegacycline (23.33%). Among the 20 CRKP strains resistant to ceftazidime/avibactam, there were 12 Klebsiella pneumoniae carbapenemase (KPC)-2-producing strains, 3 KPC-3-producing strains, 1 New Delhi metallo-β-lactamase-1 (NDM-1)-producing strain, and 1 oxacillin β-lactamase-48-producing strain; none of the 20 strains had KPC mutation.ConclusionsCeftazidime/avibactam is an effective agent agianst CRKP, and its resistance rate is significantly lower than that of other commonly used antimicrobial agents, especially other β-lactam antibiotics. In terms of resistance genes, except for one isolate producing NDM-1, no other known gene resistant to ceftazidime/avibactam has been found.