Effectiveness of tigecycline in the treatment of infections caused by carbapenem-resistant gram-negative bacteria in pediatric liver transplant recipients: A retrospective study

Epidemiology, antimicrobial resistance, and mortality risk factors of carbapenem resistant gram-negative bacteria in hematopoietic stem cell transplantation recipients

Introduction

Carbapenem resistant gram-negative bacteria (CRGNB) infection is more and more frequent in patients after hematopoietic stem cell transplantation (HSCT), and the prognosis is very poor. The purpose of this study was to investigate the clinical characteristics and risk factors for mortality with CRGNB infection in HSCT recipients, and to provide useful information for guiding the application of antibiotics and improving the prognosis in the future.

Methods

Electronic medical records of CRGNB infected patients who underwent HSCT in Xiangya Hospital from January 1, 2015 to June 30, 2022 were collected. At the same time, 1:1 case-control matching was performed according to gender, age and disease type. The epidemiological characteristics and drug resistance of patients with CRGNB infection and non-CRGNB infection were compared. Logistic regression and Cox regression analysis were used to determine the risk factors for CRGNB acquisition and death respectively, and a prediction model of overall survival was constructed by R language.

Results and Discussion

The crude infection rate of CRGNB in HSCT recipients was 7.42%, and the mortality rate was 47.1%. CRGNB was resistant to most commonly used antibiotics. Time interval from diagnosis to transplantation >180 days (HR=7.886, 95% CI 2.624-23.703, P=0.000), septic shock (HR=6.182, 95% CI 2.605-14.671, P=0.000), platelet count < 20 × 10⁹/L (HR=2.615, 95% CI 1.152-5.934, P=0.022) and total bilirubin > 34.2 μmol/L (HR=7.348, 95% CI 2.966-18.202, P=0.000) at the initial stage of infection were 4 independent risk factors associated with mortality. CRGNB infection has become a serious threat to HSCT recipients. Clinicians should pay high attention to it and actively seek personalized treatment strategies suitable for local medical conditions.

Extended-spectrum β-lactamase-producing and carbapenem-resistant Enterobacterales bloodstream infection after solid organ transplantation: Recent trends in epidemiology and therapeutic approaches

Background

Infections caused by multidrug‐resistant gram‐negative bacilli (MDR GNB), in particular extended‐spectrum β‐lactamase‐producing (ESBL‐E) and carbapenem‐resistant Enterobacterales (CRE), pose a major threat in solid organ transplantation (SOT). Outcome prediction and therapy are challenging due to the scarcity of randomized clinical trials (RCTs) or well‐designed observational studies focused on this population.

Methods

Narrative review with a focus on the contributions provided by the ongoing multinational INCREMENT‐SOT consortium (ClinicalTrials identifier NCT02852902) in the fields of epidemiology and clinical management.

Results

The Spanish Society of Transplantation (SET), the Group for Study of Infection in Transplantation of the Spanish Society of Infectious Diseases and Clinical Microbiology (GESITRA‐SEIMC), and the Spanish Network for Research in Infectious Diseases (REIPI) recently published their recommendations for the management of MDR GNB infections in SOT recipients. We revisit the SET/GESITRA‐SEIMC/REIPI document taking into consideration new evidence that emerged on the molecular epidemiology, prognostic stratification, and treatment of post‐transplant ESBL‐E and CRE infections. Results derived from the INCREMENT‐SOT consortium may support the therapeutic approach to post‐transplant bloodstream infection (BSI). The initiatives devoted to sparing the use of carbapenems in low‐risk ESBL‐E BSI or to repurposing existing non‐β‐lactam antibiotics for CRE in both non‐transplant and transplant patients are reviewed, as well as the eventual positioning in the specific SOT setting of recently approved antibiotics.

Conclusion

Due to the clinical complexity and relative rarity of ESBL‐E and CRE infections in SOT recipients, multinational cooperative efforts such as the INCREMENT‐SOT Project should be encouraged. In addition, RCTs focused on post‐transplant serious infection remain urgently needed.

Ceftazidime-Avibactam as Salvage Therapy in Pediatric Liver Transplantation Patients with Infections Caused by Carbapenem-Resistant Enterobacterales

Objective

There are few therapeutic options for infections caused by carbapenem-resistant Enterobacterales (CRE) in children following liver transplantation. Ceftazidime-avibactam (CAZ-AVI), a recently licensed antibacterial in China, was utilized as a salvage therapy against CRE in our center, and its efficacy and safety were therefore assessed.

Methods

The retrospective, observational study was conducted at the First Affiliated Hospital of Zhejiang University. Pediatric liver transplantation patients (≤12 years) who received CAZ-AVI as a salvage therapy against CRE infections were included from January 2020 to December 2021. Clinical success and all-cause death during hospitalization were the primary outcomes. Recurrence of infection, drug-related adverse events, and changes in inflammatory biomarkers were collected.

Results

Six children were enrolled, with a median age of 10.1 (interquartile range (IQR) 5.5–13.8) months. Primary intraperitoneal infections occurred in all patients, with five patients developing bloodstream infections. KPC carbapenemases were detected in most isolates, and the susceptibility results showed general sensitivity to tigecycline, polymyxin B, and CAZ-AVI. Tigecycline-based therapy was taken as the initial treatment and withdrawn because of clinical failure (5 cases) or cholestasis (1 case). After CRE infection, the median time to convert to CAZ-AVI was 7.5 (IQR 7.0–8.8) days, and the median CAZ-AVI treatment length was 21.0 (IQR 20.3–28.5) days. Clinical success was achieved in all patients, with a zero percent all-cause death rate. No CRE infections recurred throughout hospitalization, and no resistance to CAZ-AVI was detected. Patients experienced vomiting (1/6), skin rash (1/6), and a transient increase in cystatin C (2/6), γ-glutamyltransferase (2/6), and alkaline phosphatase (3/6).

Conclusion

CAZ-AVI was shown to be a successful salvage treatment for CRE infection in pediatric liver transplant recipients, with minor and temporary drug-related side effects.

Incidence, Clinicomicrobiological Characteristics, Risk Factors, and Treatment ‎Outcomes of Bacterial Infections Following Liver Transplantation in Pediatrics: A ‎Retrospective Cohort Study

Background: Liver transplantation (LT) is the definitive treatment for patients with advanced liver failure. Bacterial infections are common consequences of organ transplantation resulting from immune suppression and prolonged hospitalization. Methods: This retrospective cohort study examined the records of all liver transplant pediatrics under 18 years of age in Abu-Ali Sina hospital, Shiraz, Fars province, Iran, from April 2019 to February 2020. Demographic, laboratory, and clinical data were extracted along with the administered therapeutic approach for the patient. Results: Of 80 enrolled patients, 52 were male, and 28 were female, with a median age of 60 months. An incidence of 67.9% of bacterial infections was recorded. Gram-negative and Gram-positive pathogens accounted for 64.06% and 35.93% of infections, respectively. Surgical site infections were the most common ones. The length of ICU stay, hospitalization, mechanical ventilation duration, and re-hospitalization were significantly higher in the infected group than in non-infected pediatrics (P-value < 0.05). Multivariate regression analysis showed that the only risk factor for bacterial infections after LT was the length of ICU stay. The mortality rate was 22%, which was significantly higher among the infection group (P = 0.008). Conclusions: A high rate of bacterial infections and an increasing prevalence of nosocomial and antibiotic-resistant pathogens were detected in the early period after LT.

Tigecycline antibacterial activity, clinical effectiveness, and mechanisms and epidemiology of resistance: narrative review

Tigecycline is unique glycylcycline class of semisynthetic antimicrobial agents developed for the treatment of polymicrobial infections caused by multidrug-resistant Gram-positive and Gram-negative pathogens. Tigecycline evades the main tetracycline resistance genetic mechanisms, such as tetracycline-specific efflux pump acquisition and ribosomal protection, via the addition of a glycyclamide moiety to the 9-position of minocycline. The use of the parenteral form of tigecycline is approved for complicated skin and skin structure infections (excluding diabetes foot infection), complicated intra-abdominal infections, and community-acquired bacterial pneumonia in adults. New evidence also suggests the effectiveness of tigecycline for the treatment of severe Clostridioides difficile infections. Tigecycline showed in vitro susceptibility to Coxiella spp., Rickettsia spp., and multidrug-resistant Neisseria gonnorrhoeae strains which indicate the possible use of tigecycline in the treatment of infections caused by these pathogens. Except for intrinsic, or often reported resistance in some Gram-negatives, tigecycline is effective against a wide range of multidrug-resistant nosocomial pathogens. Herein, we summarize the currently available data on tigecycline pharmacokinetics and pharmacodynamics, its mechanism of action, the epidemiology of tigecycline resistance, and its clinical effectiveness.

Rising Klebsiella pneumoniae Infections and Its Expanding Drug Resistance in the Intensive Care Unit of a Tertiary Healthcare Hospital, Saudi Arabia

Nosocomial infections caused by Klebsiella pneumoniae and other Gram-negative organisms have emerged as a significant health problem especially in intensive care units (ICU). This study aims to examine K. pneumoniae infections in the ICU of Aseer Central Hospital and to determine their antimicrobial susceptibility and their relationship to patients' clinical outcomes. This is a retrospective observational study done in a tertiary care center in the Aseer region in Saudi Arabia. The study spanned from January 2018 to December 2019. Demographic, microbiologic, and patient outcomes were collected from 276 patients with various infections. Identification of isolates and in vitro susceptibility to 32 antimicrobial agents were done by the Vitek 2 automated system (bioMérieux, Marcy-l'Étoile, France). Prevalence of K. pneumoniae bacteria, their susceptibility to antimicrobials, and effect on clinical outcome were studied. Two hundred seventy-six K. pneumoniae were recovered from ICU patients with various infections. K. pneumoniae isolates (n=276) were collected mainly from the respiratory tract (61%) and K. pneumoniae represented 39% of the major causal agents of ICU infections, followed by Acinetobacter spp. (30%), Pseudomonas aeruginosa (10.0%), Escherichia coli (7%), and others (14%). The mortality among the 276 ICU patients was 33.3%; K. pneumoniae was connected to 42% of the cases and 67% of the total deaths were between 50 and 90 years of age. K. pneumoniae demonstrated high sensitivity and hence can be recommended for in vivo treatment for tigecycline (81%), cefazolin (77.2%), colistin (64.9%), and to a lesser extent norfloxacin (60%) and imipenem (55.5%). High resistance was detected for ampicillin (100%), extended-spectrum β-lactamases-sulbactam (ESBL-SCM) (100%), piperacillin (100%), and ceftazidime (92.5%). Resistance to carbapenems was elevated in ertapenem (65.2%) and meropenem (61.7%). The increase of K. pneumoniae represents a threat to ICU patients, although K. pneumoniae infections were results rather than the causes, as it was connected to almost half of the ICU mortalities. Tigecycline alone or in combination with colistin on high-dose regimens could be a more effective therapy for treating carbapenem-resistant K. pneumoniae infections.