Management of Gram-negative and fungal endocarditis

The Assessment of Antimicrobial Resistance in Gram-Negative and Gram-Positive Infective Endocarditis: A Multicentric Retrospective Analysis

Background and Objectives: Multidrug-resistant microorganisms have made treating bacterial infections challenging. Resistance to antibiotics is expected to overcome efforts to produce new, effective antibacterial medication that is lifesaving in many situations. Infective endocarditis (IE) is a life-threatening infection that affects 5–15 per 100,000 patients annually and requires rapid antibiotic therapy to prevent morbidity and mortality. Materials and Methods: The present research assessed IE cases over five years, from a multicentric database, with the main objective of determining the degree of antibiotic resistance in these patients, stratified by Gram-positive and Gram-negative bacteria. Results: Bad oral hygiene was present in 58.6% of patients from the Gram-negative group (vs. 38.7% in the Gram-positive group). Non-valvular heart disease was identified in approximately 40% of all patients, and valvopathies in approximately 20%. It was observed that 37.9% of Gram-negative IE bacteria were resistant to three or more antibiotics, whereas 20.7% were susceptible. Among Gram-positive infections, S. aureus was the most commonly involved pathogen, with a multidrug-resistant pattern in 11.2% of patients, while Acinetobacter baumannii had the highest resistance pattern of all Gram-negative pathogens, with 27.4% of all samples resistant to three or more antibiotics. Patients with Gram-negative IE were 4.2 times more likely to die. The mortality risk was 4 times higher when bacteria resistant to two or more antibiotics was involved and 5.7 times higher with resistance patterns to three or more antibiotics than the reference group with no antibiotic resistance. Peripheral catheters were the most common cause of multi-resistant IE, followed by heart surgery, dental procedures, and ENT interventions. Conclusions: Even though Gram-positive infections were the most frequent (83.0% of all cases), Gram-negative IE infections are substantially more deadly than Gram-positive IE infections. However, it was also observed that patients with Gram-negative infections were more likely to have underlying comorbidities, be institutionalized, and be underweight. Although the Gram-negative infections were more severe, their resistance patterns were similar to Gram-positive bacteria. As resistance patterns increase, more efforts should be made to prevent a healthcare catastrophe. At the same time, careful prophylaxis should be considered in patients at risk, including those with central catheters, undergoing dental procedures, and with poor oral hygiene.

Clinical characteristics and risk factors of tigecycline-associated hypofibrinogenaemia in critically ill patients

Purpose

To analyze the clinical features and risk factors of tigecycline-associated hypofibrinogenaemia and study whether cefoperazone/sulbactam combined with tigecycline aggravates coagulopathy or hypofibrinogenaemia.

Methods

A retrospective case–control study of patients with severe infection who were treated with tigecycline was conducted. Patients were assigned to the hypofibrinogenaemia group (< 2.0 g/L) and normal fibrinogen (normal) group (≥ 2.0 g/L) to assess the clinical features of patients with tigecycline-associated hypofibrinogenaemia. The traits of patients treated with cefoperazone/sulbactam in the hypofibrinogenaemia group were also analyzed.

Results

In total, 127 patients were enrolled in the study, including 71 patients with hypofibrinogenaemia and 56 patients with normal fibrinogen levels. Hypofibrinogenaemia developed at a median of 6 (4–8) days after tigecycline treatment, and the fibrinogen level returned to normal at a median of 3 (3–5) days after tigecycline discontinuation. In the multivariate analysis, intra-abdominal infection (p = 0.005), fibrinogen level at tigecycline initiation (p < 0.001), maintenance dose (p = 0.039), and treatment duration (p = 0.002) were found to be related to hypofibrinogenaemia. Treatment with cefoperazone/sulbactam was not associated with hypofibrinogenaemia (p = 0.681), but patients treated with cefoperazone/sulbactam had a higher incidence of coagulopathy (p = 0.009) and needed more blood products (p = 0.003) than those treated without cefoperazone/sulbactam.

Conclusion

Tigecycline-associated hypofibrinogenaemia often developed on the 6th (4th–8th) day of tigecycline use and was associated with intra-abdominal infection, fibrinogen level at tigecycline initiation, maintenance dose, and treatment duration of tigecycline but not cefoperazone/sulbactam.

Fatal Vitamin K-Dependent Coagulopathy Associated with Cefoperazone/Sulbactam: A Case Report

This case report describes a suspected and fatal adverse reaction involving vitamin K-dependent coagulopathy that might be associated with cefoperazone/sulbactam (CPZ/SAM), a combined antimicrobial formulation. We reported a patient diagnosed with acute cerebral infarction and secondary pulmonary infection who was treated with an intravenous infusion of CPZ/SAM at 3 g twice daily. After receiving treatment with CPZ/SAM, the patient developed a fatal adverse reaction of CPZ-induced hemorrhage. The Naranjo assessment score in this report was 5, suggesting that the patient's coagulation function disorder was potentially associated with the use of CPZ/SAM. To prevent vitamin K-dependent coagulopathy caused by CPZ/SAM, it is suggested to avoid cephalosporins in patients with a high risk of bleeding unless the need for cephalosporins is compelling.

Risk Factors and Outcomes of Endocarditis Due to Non-HACEK Gram-Negative Bacilli: Data from the Prospective Multicenter Italian Endocarditis Study Cohort

The objective of this study was to investigate predisposing factors and outcomes of infective endocarditis (IE) caused by non-HACEK Gram-negative bacilli (GNB) in a contemporary multicenter cohort. Patients with IE due to GNB, prospectively observed in 26 Italian centers from 2004 to 2011, were analyzed. Using a case-control design, each case was compared to three age- and sex-matched controls with IE due to other etiologies. Logistic regression was performed to identify risk factors for IE due to GNB. Factors associated with early and late mortality were assessed by Cox regression analysis. The study group comprised 58 patients with IE due to GNB. We found that Escherichia coli was the most common pathogen, followed by Pseudomonas aeruginosa and Klebsiella pneumoniae The genitourinary tract as a source of infection (odds ratio [OR], 13.59; 95% confidence interval [CI], 4.63 to 39.93; P < 0.001), immunosuppression (OR, 5.16; 95% CI, 1.60 to 16.24; P = 0.006), and the presence of a cardiac implantable electronic device (CIED) (OR, 3.57; 95% CI, 1.55 to 8.20; P = 0.003) were factors independently associated with IE due to GNB. In-hospital mortality was 13.8%, and mortality rose to 30.6% at 1 year. A multidrug-resistant (MDR) etiology was associated with in-hospital mortality (hazard ratio [HR], 21.849; 95% CI, 2.672 to 178.683; P = 0.004) and 1-year mortality (HR, 4.408; 95% CI, 1.581 to 12.287; P = 0.005). We conclude that the presence of a genitourinary focus, immunosuppressive therapy, and an indwelling CIED are factors associated with IE due to GNB. MDR etiology is the major determinant of in-hospital and long-term mortality.

Epidemiology and the prognosis of healthcare-associated infective endocarditis in China: the significance of non-nosocomial acquisition

Limited research has been conducted on healthcare-associated infective endocarditis (HAIE), although it is of increasing importance. The aim of this study is to compare the epidemiology, clinical characteristics, and prognosis of community-acquired IE (CA-IE) with HAIE and non-nosocomial healthcare-associated IE (NNHCA-IE). A retrospective, consecutive case-series analysis was organized and performed during the 20-year study period in Huashan Hospital, Shanghai, China. A total of 154 patients were enrolled, including 126 (81.8%) who had CA-IE and 28 (18.2%) who had HAIE, among whom 20 (71.4%) had non-nosocomial IE. Patients with HAIE compared to patients with CA-IE had poorer clinical conditions (Charlson comorbidity index ≥2: 35.7% vs. 15.1%, P = 0.012; immunosuppressive therapy: 21.4% vs. 4.0%, P = 0.005), underwent more prosthetic valve replacement (35.7% vs. 7.1%, P <0.001), had less streptococcus infection (16.7% vs. 51.1%, P = 0.007) but more atypical bacterial infection (50.0% vs. 21.1%, P = 0.017) and poorer outcomes (17.9% vs. 4.0%, P = 0.019). It is noteworthy that the results were quite similar between the comparison of patients with NNHCA-IE and those with CA-IE. Overall, in-hospital mortality was 6.5%. The IE acquisition site and low serum albumin levels (odds ratio (OR): 0.8; P = 0.04) were significantly associated with an increased risk of mortality. Nosocomial IE patients had an 8.3-fold and NNHCA-IE patients had 6.5-fold increase in the risk of mortality compared to CA-IE patients. In conclusion, HAIE and NNHCA-IE have important epidemiological and prognostic implications. Because NNHCA-IE usually occurs in patients residing in the community, it is suggested that these patients should be identified and treated by the community primary care clinical staff as early as possible.

Infective endocarditis due to multidrug resistant gram-negative bacilli: single centre experience over 5 years

BACKGROUND

Infective endocarditis (IE) due to gram-negative (GN) bacilli is uncommon. Although multi- and extensively-drug resistant (MDR/XDR) GN infections are emerging, very few data are available on IE due to these microrganisms.

METHODS

In this study, we describe the clinical characteristics, course and outcome of five contemporary, definite, MDR/XDR GNIE cases seen at our centre.

RESULTS

All patients had been admitted to a hospital during the 6months before IE onset, 2 were on hemodialysis and 3 on intravenous medications. Three of the 5 cases were hospital-acquired. Intracardiac prosthetic devices were present in all cases (3 central venous lines, 2 prosthetic heart valves, 2 pacemakers). Mean Charlson comorbidity index was 5.8. Causative pathogens were XDR Pseudomonas aeruginosa (2 cases), XDR Acinetobacter baumannii, MDR Burkolderia cepacia and MDR Escherichia coli (1 case each). Concomitant pathogens with a MDR/XDR phenotype were isolated in 4 patients. Both valves and intracardiac devices and left and right sides of the heart were involved. The rate of complications was high. Antibiotic treatment hinged on the use of colistin, a carbapenem or both. Cardiovascular surgical procedures were performed in 3 patients. Despite aggressive therapeutic regimens, outcomes were poor. Clearance of bacteremia was obtained in 3 patients, in-hospital death occurred in 3 patients, only 1 patient survived during follow up.

CONCLUSIONS

MDR/XDR GN are emerging as a cause of IE in carriers of intracardiac prostheses with extensive healthcare contacts and multiple comorbidities. Resistant GNIE has a complicated course and shows a dismal prognosis.

Community-acquired multidrug-resistant Gram-negative bacterial infective endocarditis

We describe two cases of bacterial endocarditis secondary to multidrug-resistant Gram-negative organisms. In both cases, the diagnosis was made in accordance with the modified Duke's criteria and confirmed by histopathological analysis. Furthermore, in both instances there were no identifiable sources of bacteraemia and no history of contact with hospital or other medical services prior to the onset of symptoms. The patients were managed in similar fashion with prolonged broad-spectrum antibiotic therapy and surgical intervention and made complete recoveries. These cases highlight Gram-negative organisms as potential agents for endocarditis, as well as expose the dissemination of such multidrug-resistant bacteria into the community. The application of an integrated medical and surgical approach and therapeutic dilemmas encountered in managing these cases are described.