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.
Objective To investigate the risk factors for Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections, and construct a clinical model for predicting the risk of CRKP infections. Methods A retrospective analysis was performed on Klebsiella pneumoniae infection patients hospitalized in the Third Hospital of Hebei Medical University from May 2020 to May 2021. The patients were divided into a CRKP group (117 cases) and a Carbapenem-sensitive Klebsiella pneumoniae (CSKP) group (191 cases). The predictors were screened by full subset regression using R software (version 4.3.1). The truncation values of continuous data were determined by Youden index. Nomogram and score table model for CRKP infections risk prediction was constructed based on binary logistic regression. The receiver operator characteristic (ROC) curve and area under curve (AUC) were used to evaluate the accuracy of models. Calibration curve and decision curve were used to evaluate the performance of models. Results308 patients with Klebsiella pneumoniae infections were included. A total of 8 predictors were selected by using full subset regression and truncation values were determined according to Youden index: intensive care unit (ICU) stay at time of infection>2 days, male, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) score>15 points, hospitalization stay at time of infection>10 days, any history of Gram-negative bacteria infection in the last 6 months, heart disease, lung infection, antibiotic exposure history in the last 6 months. The AUC of CRKP prediction risk curve model was 0.811 (95%CI 0.761 - 0.860). When the optimal cut-off value of the constructed CRKP prediction risk rating table was 6 points, the AUC was 0.723 (95%CI 0.672 - 0.774). The Bootstrap method was used for internal repeated sampling for 1000 times for verification. The model calibration curve and Hosmer-Lemeshow test (P=0.618) showed that these models have good calibration degree. The decision curve showed that these models have good clinical effectiveness. Conclusion The prediction model of CRKP infections based on the above 8 risk factors can be used as a risk prediction tool for clinical identification of CRKP infections.
ObjectiveTo study the distributions of virulence genes of Klebsiella pneumoniae (KP) and the distribution of hypervirulent KP (HvKP), and assess the performance of a single gene to predict HvKP.MethodsPolymerase chain reaction (PCR) method was used to analyze 12 virulence-related genes (entB, irp2, iroN, iucA, mrkD, fimH, c-rmpA, p-rmpA2, p-rmpA, wzy-K1, allS and peg-344) and drug-resistance gene blaKPC among 376 clinical KP strains collected from January 2016 to December 2018. Sequence types (ST) of KP were determined after sequencing and comparison, following the detection of 7 house-keeping genes (gapA, infB, mdh, pgi, phoE, rpoB and tonB) by PCR method. Statistical analyses were made for the distributions of virulence genes of KP and the distribution of HvKP with GraphPad Prism 8 software.ResultsAmong the 376 KP strains, the positive rates of entB, irp2, iroN, iucA, mrkD, fimH, c-rmpA, p-rmpA2, p-rmpA, wzy-K1, allS and peg-344 were 100.0%, 76.9%, 22.1%, 28.2%, 97.6%, 97.1%, 1.6%, 24.5%, 21.0%, 7.4%, 4.8% and 31.6%, respectively. The positive rates of the aforementioned virulence genes in the blaKPC-positive group (n=167) were 100.0%, 94.0%, 7.2%, 16.8%, 97.0%, 96.4%, 0.0%, 15.0%, 6.6%, 0.0%, 0.0% and 21.0%, respectively, and those in the blaKPC-negative group (n=209) were 100.0%, 63.2%, 34.0%, 37.3%, 98.1%, 97.6%, 2.9%, 32.1%, 32.5%, 13.4%, 8.6% and 40.2%, respectively; there was no statistically significant difference in entB, mrkD or fimH between the two groups (P>0.05), the positive rate of irp2 was higher in the blaKPC-positive group than that in the blaKPC-negative group (P<0.05), and the positive rates of the rest virulence-related genes were lower in the blaKPC-positive group than those in the blaKPC-negative group (P<0.05). The rate of HvKP in the blaKPC-negative group was higher than that in the blaKPC-positive group (38.3% vs. 18.0%, P<0.05). As a marker of HvKP, iucA showed high sensitivity and specificity (90.9% and 97.7%), followed by p-rmpA2 (83.6% and 100.0%) and iroN (73.6% and 99.2%). ST11 accounted for 87.4% in the blaKPC-positive group, while ST23, ST20, ST54 and ST29 were the four primary types in the blaKPC-negative group, accounting for 23.4% totally.ConclusionsDifferent virulence genes mean different distributions in KP. blaKPC-negative KP is more virulent than blaKPC-positive KP. iucA and p-rmpA2 could serve as good predicators of HvKP. Armed with extreme virulence and drug-resistance, blaKPC-positive HvKP is of great clinical concern.
ObjectivesTo identify the clinical characteristics and prognosis for CRKP (Carbapenem-resistant Klebsiella pneumonia, CRKP) infection among ICU patients in the Second Affiliated Hospital of Anhui Medical University. MethodsWe conducted a retrospectively analysis in which 19 patients infected by CRKP with another 21 CSKP (Carbapenem-sensitive Klebsiella pneumoniae, CSKP) infected patients from January 2017 to April 2018. Risk factors for CRKP infection were assessed. ResultsThe lower respiratory tract is the most common site of CRKP infection in our department. CRKP infection was associated with several clinical symptoms, particularly a higher incidence of sepsis shock (χ2=8.338, P=0.004), more application of the combined medicine (χ2=26.3, P<0.001), prolonged hospital stays (χ2=–2.217, P=0.027) and more expenses on antibiotics (χ2=12.855, P=0.005), and the declined survival rates in 14 days (χ2=4.269, P=0.039) and 21 days (χ2 =5.647, P=0.017). The resistance rate of CRKP strains was high, however no resistance to tegafycline was found. The risk factors of CRKP infection included three generations of cephalosporin and/or hydrocarbonase antibiotics exposure (χ2 =6.388, P=0.041), exposure time of three generations of cephalosporin (U=–2.187, P=0.029), exposure time of hydrocarbonase antibiotics (U=–2.103, P=0.035), tracheal intubation (χ2=6.352, P=0.012), tracheotomy (χ2 =4.821, P=0.028), SOFA score (t=4.505, P<0.001) and Charlson comorbidity index (t=3.041, P=0.004). The SOFA score was the only factor independently associated with CRKP bacteremia (P=0.02). ConclusionsCRKP infections in ICU directly affect the course of disease, survival time and treatment expenses of patients. Therefore, monitoring bacterial resistance, rational use of antibiotics, and protection of the immune function are of great significance for prevention and treatment of CRKP infection.
目的 探討高毒力肺炎克雷伯菌（hypervirulent Klebsilla pneumoniae，hvKP）感染患者的臨床特征、診斷方法和治療過程，提高臨床醫生對 hvKP的認識。方法 回顧性分析1例hvKP感染患者的一般資料、影像學表現和治療方案，并進行相關文獻復習。結果 患者男，52歲，因發熱1+個月入院，入院CT提示：左肺下葉外基底段胸膜下占位伴雙肺散在多發結節，周圍型肺癌伴轉移？炎性？肝S6-7段占位，肝膿腫？痰及肝膿液培養均發現肺炎克雷伯菌，二代測序示肺炎克雷伯菌，故考慮為hvKP感染。根據藥敏結果先后調整抗生素為美羅培南（1.0 g 2次/d）聯合頭孢他啶（3.0 g 2次/d）、左氧氟沙星（0.5 g 1次/d）聯合頭孢他啶（3.0 g 2次/d）、頭孢哌酮鈉舒巴坦鈉聯合阿米卡星治療，并予引流肝膿腫及胸腔積液后，患者癥狀、體征和影像學異常均明顯好轉，隨訪復查，病灶基本吸收。結論 肺炎克雷伯菌肝膿腫合并膿毒性肺栓塞患者，影像表現疑似肺癌伴肺內轉移。針對該類患者，臨床醫生應考慮肺炎克雷伯菌感染可能，盡早獲取病原學證據，同時關注hvKP常見的侵襲部位，結合藥敏試驗及抗生素藥效學/藥代動力學特點，選用合適的抗生素，從而改善疾病預后。
Objective To investigate the clinical characteristics and drug resistance changes of nosocomial infection caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) in different types of clinical departments, and to provide evidence for prevention and control of CRKP infection. Methods The hospital infection real-time monitoring system was used to retrospectively collect the inpatients with CRKP nosocomial infection in the First People’s Hospital of Lianyungang from January 2019 to December 2023 as the research objects. According to the different sources of departments, they were divided into intensive care unit (ICU) group, internal medicine group and surgery group. The changes of clinical characteristics and drug resistance to common antibiotics were analyzed. Results A total of 636188 inpatients were monitored, and 225 cases were infected with CRKP, with an overall infection detection rate of 0.035%. The detection rates of CRKP infection in the ICU group, internal medicine group, and surgery group were 0.736% (138/18749), 0.013% (44/336777), and 0.015% (43/280662), respectively, with the ICU group demonstrating a significantly higher rate than the other groups (P<0.05). The detection rates fluctuated in the early stage and then decreased rapidly in different years. The main infection site of CRKP in all groups was lower respiratory tract, but the proportion of device-related infections in the ICU group was higher than that in the internal medicine and surgery groups (P<0.05). In terms of the infected population, there was no significant difference in gender among groups (P>0.05) with the proportion of males more than 60%, while the difference in the proportion of patients aged ≥65 years among groups was statistically significant (P<0.05), with the highest in the internal medicine group (86.36%). The burden of underlying diseases and invasive operation exposure of the infected patients were high, and the proportion of cardiovascular and cerebrovascular diseases and indwelling catheters were as high as 69.33% and 83.56%, respectively. The differences in the proportions of cardiovascular and cerebrovascular diseases, diabetes mellitus, ≥3 underlying diseases, and surgical and invasive procedures among groups were statistically significant (P<0.05). The distribution of infection specimens in each group showed no statistically significant difference (P>0.05), with sputum, blood, and mid-stream urine specimens being the main detected specimens in all groups. The resistance rates of CRKP to penicillins and cephalosporins were more than 93%, and the resistance rates to aminoglycosides and sulfonamides were relatively low and showed a decline year by year. The resistance rate to ceftazidime/avibactam was only 7.41%, but the resistance rate to tigecycline increased. The difference in resistance rate of CRKP to co-trimoxazole among groups was statistically significant (P<0.05), while the differences in resistance to other antimicrobial agents were not statistically significant (P>0.05). Conclusions The detection rate, clinical characteristics and drug resistance of CRKP infection in different types of departments of medical institutions are different and changing. It is necessary to strengthen the rational use of antibiotics and the prevention and control of nosocomial infection.
ObjectiveTo observe and analyze the clinical features and prognosis of endogenous klebsiella pneumoniae endophthalmitis (EKPE).MethodsThis is a retrospective case series study. Seven patients (8 eyes) with EKPE were enrolled in this study. There were 3 males (4 eyes) and 4 females (4 eyes). The ages were from 39 to 76 years, the mean age was 57.29 years. All these cases had no history of trauma and surgery. Meanwhile, they all had some risk factors, such as infection, diabetes mellitus, systemic lupus erythematosus, liver abscess, renal insufficiency undergoing dialysis treatment, Hodgkin lymphoma and so on. All the eyes were undertaken visual acuity, slit lamp and fundus examination to observe the eye conditions. Seven eyes were undertaken pars plana vitrectomy with intravitreal injection of antibiotics from 2 days to 2 weeks after onset. And only one eye was undertaken intravitreal injection of antibiotics without surgery. Microbial stains and culture were performed for 7 eyes using vitreous and aqueous fluid samples from the procedures of vitrectomy. Meanwhile, culture and drug sensitive tests were performed from blood samples. According to the result of the drug sensitive tests, carbapenems such as imipenem and meropenem were used in each patient through intravenous injection from 1 to 2 weeks. During the follow up period from 3 days to 1 year, prognosis was observed at each office visit.ResultsFrom these eight eyes, presenting visual acuity was light perception (4 eyes), hand motion (3 eyes), 0.1 (1 eye). Hypopyon (6 eyes), aqueous fluid opacity (2 eyes) and diffuse vitreous opacity (8 eyes) were found. Changes in fundus like optic disc, macular edema and retinal vascular occlusion could be observed. Cultures of the vitreous and aqueous fluid samples from vitrectomy were all point out to klebsiella pneumoniae. At last office visit, the visual acuity of patients with hypopyon was no light perception (1 eye), light perception (1 eye), hand motion (1 eye). The visual acuity of patients without hypopyon was 0.05 (1 eye) and 0.5(1 eye). Finally, 1 eye was underwent enucleation and one patient with binocular disease was died of multiple organ failure.ConclusionsEKPE is almost unilateral attacked. Changes in fundus like optic disc, macular edema and retinal vascular occlusion can be observed. EKPE is commonly associated with poor visual outcomes. It is useful to save patients’ visual acuity by performing vitrectomy before hypopyon happened.
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.
