Views: 0 Author: Datafei Medical Publish Time: 2022-12-14 Origin: 迪飞医学
/ guide /
In August 2022, the team of Professor Tian Ye from the Urology Department of Beijing Friendship Hospital Affiliated to Capital Medical University, in cooperation with Difei Medical, published a case report in the journal Infection and Drug Resistance (IF=4.1772), describing a case of Corynebacterium striata. Diagnosis and treatment process of a 35-year-old male patient with congenital valvular endocarditis.Metagenomic sequencing of mitral valve and neoplastic tissue during treatment revealed Corynebacterium striata infection.
/ Research Background /
Infective endocarditis (IE) refers to inflammation of the heart valves or ventricular walls caused by various pathogens.IE can lead to valvular disease, heart failure and even thromboembolic disease, which endanger the life of patients.After kidney transplantation, patients need to receive immunosuppressive therapy for life, and the risk of severe infection may be higher than that of immunonormal populations.When IE occurs in kidney transplant recipients, the infection usually has specific clinical features and is difficult to control.With the development of new sequencing technology, the incidence of Corynebacterium striatum (C. striatum) infection has increased in recent years, and detection methods such as mNGS have also provided more references for clinical diagnosis and treatment.
/ research content /
—— ✦ Case presentation✦ ——
patient:A 35-year-old male with autosomal dominant polycystic kidney disease underwent kidney transplantation for end-stage renal failure
Donor:A 57-year-old male was diagnosed with brain death caused by hypertensive cerebral hemorrhage, and the donor did not report a confirmed infection.
Immune Induction Therapy:Methylprednisolone, Basiliximab, ATG
1-5 days after surgery:Different doses of methylprednisolone, ATG
Maintenance immunosuppressive regimen:Tacrolimus + Mycophenolate Sodium Enteric-Coated Tablets + Prednisone Acetate Tablets
Postoperative day 4:Coryneform bacteria detected in donor kidney preservation solution
On the 3rd, 7th, and 11th day after surgery:Blood, urine, and surgical site samples were culture-free for the pathogen.
Routine oral trimethoprim/sulfamethoxazole was used to prevent PJP after operation, and the antibiotic regimen was ceftazidime 2g, once every 12 hours, for 2 weeks.
Postoperative day 56:The patient presented with a low-grade fever (37.9°C) and was diagnosed with septic shock and disseminated intravascular coagulation due to severe infection.The immunosuppressive maintenance regimen was gradually reduced, mycophenolate mofetil was discontinued, tacrolimus was changed to cyclosporine, and meropenem was given for anti-infection.
Postoperative day 59:Corynebacterium was detected in the blood of the patient, and Enterococcus faecium and Pseudomonas putida were detected in the urine.Linezolid was additionally administered.
On the 65th day after surgery:Sudden persistent precordial angina, accompanied by chest tightness, anhidrosis, and elevated myocardial enzymes.There were murmurs in all valves of the heart, especially in the apical region. The diastolic murmur was grade 3/6. Echocardiography showed a moderately echogenic mass at the posterior end of the mitral valve, which oscillated with the cardiac cycle (Figure 1).
Figure 1 Echocardiogram showed an iso-mass at the posterior end of the mitral valve, which oscillated with the cardiac cycle
Postoperative day 71:The patient went into cardiac arrest with TCPDF ventricular fibrillation before entering the operating room.Chest compressions, defibrillation, and endotracheal intubation were performed in the emergency department.Mitral valve replacement and vegetation resection were performed after the vital signs were stabilized. The patient was unable to maintain vital signs after the operation and died on the 73rd day after the kidney transplantation.However, no pathogens were cultured from the mitral valve or neoplastic tissue.
Retrospective analysis:Reviewing the clinical data of this patient, in the pathological section of valve tissue and vegetation, large polypoid vegetations of fibrin and platelets were seen along the surface of the ruptured endocardium (Fig. 2B).Gram staining of the pathological sections revealed acute inflammation of the neoplasm with bacterial colonies in the valves and necrotic areas of leukocytes (Fig. 2C).Retrospective mNGS was performed on the valve tissue, conclusively identifying endocarditis with C. striatae (Fig. 2D).
Fig.2 Morphological, pathological and microbiological data of valve tissue and vegetation tissue after resection
The article retrospectively analyzed 30 published cases of Corynebacterium striata endocarditis, the clinical manifestations were mainly native valve endocarditis (80%, 24/30), and the mitral valve was the most common (43.3%, 24/30). 13/30), followed by the aortic valve (30%, 9/30).Four cases of striatobacterial endocarditis were confirmed by molecular genetic testing, and the remaining cases were confirmed by traditional culture testing.Corynebacterium striatum is a common corynebacterium in clinical microbiology laboratories, but confirmed infection with Corynebacterium striatum is relatively rare.In the diagnosis of Corynebacterium striatae endocarditis, although traditional diagnostic methods based on microbiological laboratory test results are relatively mature and relatively low-cost, most of them are time-consuming and have a low positive rate, and even misidentification may occur.mNGS has higher sensitivity than conventional methods and is therefore recommended for early diagnosis of IE pathogens.
Table 1 Report of 30 cases of infective endocarditis caused by Corynebacterium striatae
/ Summarize /
1. Adequate anti-infection treatment should be given to kidney transplant recipients at high risk of IE, and bacterial culture and sensitivity tests should be monitored intermittently during hospitalization.Anti-infective treatment requirements may include adequate long-term and combination antibiotics based on susceptibility testing.When unexplained low-grade fever and non-specific clinical symptoms appear, IE should be considered and checked in time.
2. When IE of valvular hyperplasia occurs in patients after renal transplantation, the prognosis may be poor or the risk of death may be extremely high.According to research reports, early surgical intervention can improve the survival rate and reduce the mortality rate of IE.Such interventions are recommended concurrently with anti-infective therapy.
3. mNGS technology has a good application prospect in IE management.When infection with a rare pathogen is clinically suspected, molecular methods can be used for detection.Some studies have reported that the detection rate of Corynebacterium striata in blood culture is low.In this case, the culture method also failed to use the mitral valve and vegetation tissue to identify the pathogen, and the patient's valve tissue was retrospectively detected by mNGS, and the final diagnosis of Corynebacterium striata endocarditis was confirmed by mNGS technology A case of Corynebacterium striatae endocarditis in a renal recipient.
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