The risk factors for mortality in deceased donor liver transplant recipients with bloodstream infections

Bloodstream infections after solid organ transplantation: clinical epidemiology and antimicrobial resistance (2016-21)

Background

Solid organ transplant (SOT) recipients are at risk of bloodstream infections (BSIs) with MDR organisms (MDROs).

Objectives

To describe the epidemiology of BSI in the year after several types of SOT, as well as the prevalence of MDRO infections in this population.

Methods

We conducted a single-centre, retrospective study of kidney, liver, heart, and multi-organ transplantation patients. We examined BSIs ≤1 year from SOT and classified MDRO phenotypes for Staphylococcus aureus, enterococci, Enterobacterales, Pseudomonas aeruginosa and Candida spp. We compared BSI characteristics between SOT types and determined risk factors for 90 day mortality.

Results

We included 2293 patients [1251 (54.6%) kidney, 663 (28.9%) liver, 219 (9.6%) heart and 160 (7.0%) multi-organ transplant]. Overall, 8.5% of patients developed a BSI. BSIs were most common after multi-organ (23.1%) and liver (11.3%) transplantation (P < 0.001). Among 196 patients with BSI, 323 unique isolates were recovered, 147 (45.5%) of which were MDROs. MDROs were most common after liver transplant (53.4%). The most frequent MDROs were VRE (69.8% of enterococci) and ESBL-producing and carbapenem-resistant Enterobacterales (29.2% and 27.2% of Enterobacterales, respectively). Mortality after BSI was 9.7%; VRE was independently associated with mortality (adjusted OR 6.0, 95% CI 1.7-21.3).

Conclusions

BSI incidence after SOT was 8.5%, with a high proportion of MDROs (45.5%), especially after liver transplantation. These data, in conjunction with local antimicrobial resistance patterns and prescribing practices, may help guide empirical antimicrobial selection and stewardship practices after SOT.

Clinical features of invasive fungal disease in children with no underlying disease

There is limited research into Invasive fungal disease (IFD) in children with no underlying disease. We undertook a retrospective study of children with IFD who did not suffer from another underlying disease, from June 2010 to March 2018 in Changsha, China. Nine children were identified. Eosinophil counts were elevated in six cases. The level of procalcitonin (PCT) was elevated in six cases. Fungal culture was positive in all patients, including eight cases of Cryptococcus neoformans and one case of Candida parapsilosis. 8.33 days following antifungal treatment, the body temperature of the eight patients affected by cryptococcal disease had returned to normal. Our study indicates that the primary pathogen in IFD was Cryptococcus neoformans in children who had no other underlying disease. Eosinophils can be considered to be indicators of cryptococcal infection. IFD in children with no other underlying disease has a satisfactory prognosis.

Long-term mortality risk stratification of liver transplant recipients: real-time application of deep learning algorithms on longitudinal data

BACKGROUND

Survival of liver transplant recipients beyond 1 year since transplantation is compromised by an increased risk of cancer, cardiovascular events, infection, and graft failure. Few clinical tools are available to identify patients at risk of these complications, which would flag them for screening tests and potentially life-saving interventions. In this retrospective analysis, we aimed to assess the ability of deep learning algorithms of longitudinal data from two prospective cohorts to predict complications resulting in death after liver transplantation over multiple timeframes, compared with logistic regression models.

METHODS

In this machine learning analysis, model development was done on a set of 42 146 liver transplant recipients (mean age 48·6 years [SD 17·3]; 17 196 [40·8%] women) from the Scientific Registry of Transplant Recipients (SRTR) in the USA. Transferability of the model was further evaluated by fine-tuning on a dataset from the University Health Network (UHN) in Canada (n=3269; mean age 52·5 years [11·1]; 1079 [33·0%] women). The primary outcome was cause of death, as recorded in the databases, due to cardiovascular causes, infection, graft failure, or cancer, within 1 year and 5 years of each follow-up examination after transplantation. We compared the performance of four deep learning models against logistic regression, assessing performance using the area under the receiver operating characteristic curve (AUROC).

FINDINGS

In both datasets, deep learning models outperformed logistic regression, with the Transformer model achieving the highest AUROCs in both datasets (p<0·0001). The AUROC for the Transformer model across all outcomes in the SRTR dataset was 0·804 (99% CI 0·795-0·854) for 1-year predictions and 0·733 (0·729-0·769) for 5-year predictions. In the UHN dataset, the AUROC for the top-performing deep learning model was 0·807 (0·795-0·842) for 1-year predictions and 0·722 (0·705-0·764) for 5-year predictions. AUROCs ranged from 0·695 (0·680-0·713) for prediction of death from infection within 5 years to 0·859 (0·847-0·871) for prediction of death by graft failure within 1 year.

INTERPRETATION

Deep learning algorithms can incorporate longitudinal information to continuously predict long-term outcomes after liver transplantation, outperforming logistic regression models. Physicians could use these algorithms at routine follow-up visits to identify liver transplant recipients at risk for adverse outcomes and prevent these complications by modifying management based on ranked features.

FUNDING

Canadian Donation and Transplant Research Program, CIFAR AI Chairs Program.

Predictors of Mortality During Initial Liver Transplant Hospitalization and Investigation of Causes of Death

BACKGROUND Liver transplant (LT) remains a life-saving procedure with a high mortality rate. The present study investigated the causes of death and sought to identify predictive factors of mortality during the initial LT hospitalization. MATERIAL AND METHODS We retrieved data on first-time adult recipients who underwent LT between November 2017 and October 2019 receiving grafts from donation after citizen's death. The risk factors for mortality during the initial LT hospitalization were confirmed by univariate analysis. We also analyzed the causes of death. RESULTS We enrolled 103 recipients, including 86 males and 17 females, with a mean age of 47.7 years. Thirty-eight (36.9%) recipients were labeled as non-cholestatic cirrhosis-related indications. Approximately 8% of all recipients had diabetes prior to LT. Induction therapy was used in 11 (10.7%) recipients, along with maintenance therapy. The median model for end-stage liver disease score at LT was 32.4 (21.4-38.4). The in-hospital mortality rate of LT recipients was 6.8% (7/103), and infections were responsible for most of the deaths (6/7). The 1 remaining death resulted from primary graft failure. Univariate analysis showed recipients with postoperative pneumonia (p2 mg/dL, and alanine transaminase on day 1 after LT >1800 µmol/L (all P<0.001) were much more likely to die. CONCLUSIONS In-hospital mortality of LT recipients was high, due in large part to infections. Acute hepatic necrosis, prolonged post-transplant ICU stays, certain types of postoperative infections, and postoperative liver and kidney dysfunction were potential risk factors for in-hospital mortality of LT recipients.

Infection within 2 weeks before liver transplantation closely related to prognosis of posttransplant infection: A single-center retrospective observational study in China

BACKGROUND

Infections still represent the main factors influencing morbidity and mortality following liver transplantation. This study aimed to evaluate the incidence and risk factors for infection and survival after liver transplantation.

METHODS

We retrospectively examined medical records in 210 liver recipients who underwent liver transplantation between April 2015 and October 2017 in our hospital. Clinical manifestations and results of pathogen detection test were used to define infection. We analyzed the prevalence, risk factors and prognosis of patients with infection.

RESULTS

The median follow-up was 214 days; the incidence of infection after liver transplantation was 46.7% (n = 98) which included pneumonia (43.4%), biliary tract infection (21.9%), peritonitis (21.4%) and bloodstream infection (7.6%). Among the pathogens in pneumonia, the most frequently isolated was Acinetobacter baumanii (23.5%) and Klebsiella pneumoniae (21.2%). Model for end-stage liver disease (MELD) score (OR = 1.083, 95% CI: 1.045-1.123; P < 0.001), biliary complication (OR = 4.725, 95% CI: 1.119-19.947; P = 0.035) and duration of drainage tube (OR = 1.040, 95% CI: 1.007-1.074; P = 0.017) were independent risk factors for posttransplant infection. All-cause mortality was 11.0% (n = 23). The prognostic factors for postoperative infection in liver recipients were prior-transplant infection, especially pneumonia within 2 weeks before transplantation. Kaplan-Meier curves of survival showed that recipients within 2 weeks prior infection had a significantly lower cumulative survival rate compared with those without infection (65.2% vs. 90.0%; hazard ratio: 4.480; P < 0.001).

CONCLUSIONS

Infection, especially pneumonia within 2 weeks before transplantation, complication with impaired renal function and MELD score after 7 days of transplantation was an independent prognostic factor for postoperative infection in liver transplant recipients.

Pseudomonas aeruginosa bacteremia among liver transplant recipients

Pseudomonas aeruginosa bacteremia remains as a life-threatening complication after liver transplantation (LT) and is intractable because of the high rate of drug resistance to commonly used antibiotics. To better understand the characteristics of this postoperative complication, PubMed and Embase searches as well as reference mining was done for relevant literature from the start of the databases through August 2018. Among LT recipients, the incidence of P. aeruginosa bacteremia ranged from 0.5% to 14.4% and mortality rates were up to 40%. Approximately 35% of all episodes of bloodstream infections (BSIs) were P. aeruginosa bacteremia, of which 47% were multidrug resistant and 63% were extensively drug resistant. Several factors are known to affect the mortality of LT recipients with P. aeruginosa bacteremia, including hypotension, mechanical ventilation, and increasing severity of illness. In LT recipients with P. aeruginosa bacteremia, alteration in DNA gyrase A genes and overexpression of proteins involved in efflux systems, namely the expression of KPC-2-type carbapenemase, NDM-1, and VIM-2-type MBL, contribute to the high resistance of P. aeruginosa to a wide variety of antibiotics. Because of complicated mechanisms of drug resistance, P. aeruginosa causes high morbidity and mortality in bacteremic LT patients. Consequently, early detection and treatment with adequate early targeted coverage for P. aeruginosa BSI are of paramount importance in the early posttransplantation period to obtain a better prognosis for LT patients.

Methicillin-resistant Staphylococcus aureus bacteremia among liver transplant recipients: epidemiology and associated risk factors for morbidity and mortality

Bacteremia due to Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), complicates the clinical course of liver transplantation and is associated with high morbidity and mortality. Intravascular catheters had been reported to be the most frequent source of MRSA bacteremia. Among bacteremic liver recipients, 26.3%-100% of S. aureus were MRSA. Previous studies identified pre-transplant and post-transplant acquired S. aureus carriage, greater severity of liver disease, hepatocellular carcinoma and infection with immuno-modulatory viruses as predictors of S. aureus bacteremia in liver recipients. MRSA bacteremia accompanied by pneumonia and abdominal infections was related to mortality. Vancomycin, as well as daptomycin, is a first-line antibiotic for MRSA bacteremia. The purpose of this review is to better understand the characteristics of MRSA bacteremia by summarizing the epidemiology and antimicrobial resistance of S. aureus, the primary source, and related risk factors for morbidity and mortality of MRSA bacteremia. We have also explored the diagnostic, therapeutic and preventive measures for MRSA bacteremia to improve the outcomes of liver recipients.

Factors influencing mortality in abdominal solid organ transplant recipients with multidrug-resistant gram-negative bacteremia

BACKGROUND

Although multidrug-resistant (MDR) gram-negative bacteremia (GNB) has been recognized as an important cause of morbidity and mortality among abdominal solid organ transplant (ASOT) recipients, there are no data on its prognostic factors after an interim standard definition of MDR was proposed in 2012. The objective of this study was to describe the epidemiology, microbiology, and predictors of infection-related 30-day mortality in ASOT recipients with MDR GNB.

METHODS

We performed a retrospective, double-center analysis of ASOT patients with MDR GNB over a 13-year study period. Univariate and multivariate analyses were performed to identify the risk factors for mortality.

RESULTS

During the observational period, 2169 subjects underwent ASOT. Ninety-nine episodes of MDR GNB were diagnosed in 91 (4.6%) ASOT recipients, with a predominance of E.coli (29 isolates, 29.3%) and A.baumanii (24 isolates, 24.2%). The median age of these 91 recipients was 45 years (interquartile range 35-54). Mortality after the first episode of MDR GNB was 39.6% (36 deaths). The univariate analysis identified the following variables as predictors of MDR GNB-related mortality: lung focus (P = 0.001),nosocomial origin (P = 0.002), graft from donation after cardiac death or deceased donors (P = 0.023), presence of other concomitant bloodstream infection (P < 0.001), temperature of 40 °C or greater at the onset of MDR GNB (P = 0.039), creatinine > 1.5 mg/dl (P = 0.006), albumin < 30 g/L (P = 0.009), platelet count < 50,000/mm3 (P < 0.001), and septic shock (P < 0.001). In the multivariate logistic regression analysis, septic shock (odds ratio (OR) = 160.463, 95% confidence interval (CI) = 19.377-1328.832, P < .001), as well as creatinine > 1.5 mg/dl (OR = 24.498, 95% CI = 3.449-173.998, P = 0.001), nosocomial origin (OR = 23.963, 95% CI = 1.285-46.991, P = 0.033), and presence of other concomitant bloodstream infections (OR = 27.074, 95% CI = 3.937-186.210, P = 0.001) were the variables associated with MDR GNB-related 30-day mortality.

CONCLUSIONS

MDR GNB was associated with high morbidity and mortality in ASOT recipients, with a predominant causative organisms being E.coli and A.baumanii. Nosocomial origin, as well as presence of other concomitant bloodstream infections, increased creatinine level and septic shock were the main predictors of MDR GNB-related 30-day mortality.

Mortality predictors in recipients developing acute respiratory distress syndrome due to pneumonia after kidney transplantation

BACKGROUND

The aim of the present study was to investigate the risk factors related to hospital mortality due to infection in kidney recipients with ARDS meeting the Berlin definition.

METHODS

Univariate and multivariate logistic regression analysis were used to confirm the independent risk factors related to infection-associated mortality.

RESULTS

From January 2001 to August 2014, a total of 94 recipients with acute respiratory dress syndrome (ARDS) caused by pneumonia following kidney transplantation were enrolled in the present study. The most common type of infection was bacterial (52/94; 55.3%), viral (25/94; 26.6%), and polymicrobial (14/94; 14.9%). The most common ARDS was diagnosed within 6 months after transplantation (76/94; 80.9%). There were 39 deaths in these recipients (39/94; 41.5%). Eleven (11.7%) patients had mild, 47 (50.0%) moderate, and 36 (38.3%) severe ARDS; mortality was 27.3, 27.7, and 63.9%, respectively. The independent predictors of infection-related mortality were serum creatinine level >1.5 mg/dL at ARDS onset (OR 3.5 (95%CI 1.2-10.1), p = 0.018) and severe ARDS (OR 3.6 (95%CI 1.4-9.7), p = 0.009) in the multivariate analysis.

CONCLUSION

Infection-related mortality in kidney transplant patients with ARDS was associated with high serum creatinine level and severe ARDS.

The Bacteremia Caused by Non-Lactose Fermenting Gram-Negative Bacilli in Solid Organ Transplant Recipients

BACKGROUND

Blood stream infections (BSIs) remain as a serious life-threatening condition after solid organ transplant (SOT). In recent years, a progressive growth in the incidence of bacteremia caused by non-lactose fermenting gram-negative bacilli (NLF GNB) has been observed. NLF GNB led to high mortality among SOT recipients with bacteremia and were difficult to treat because of their high drug resistance to commonly used antibiotics.

METHODS

Two electronic databases, PUBMED and EMBASE, were searched for relevant literature published up to January 2015, to better understand the characteristics of bacteremia because of NLF GNB.

RESULTS

The morbidity and mortality rates of bacteremia because of NLF GNB depend on the types of organisms and transplantation. Multi-drug resistant NLF GNB ranged from 9.8% to 12.5% of all NLF GNB causing BSIs among SOT recipients. Certain factors can predispose SOT recipients to NLF GNB bacteremia, which included previous transplantation, hospital-acquired BSIs, and prior intensive care unit admission. Combination therapy may be beneficial in the treatment of NLF GNB bacteremia to enhance antimicrobial activity, provide synergistic interactions, relieve side effects, and minimize superinfections.

CONCLUSIONS

Prevention is pivotal in minimizing the morbidity and mortality associated with NLF GNB bacteremia after SOT. To improve the outcomes of SOT recipients with NLF GNB bacteremia, prevention is pivotal, and combination therapy of antibiotics may be beneficial.

Mortality Predictors in Acute Respiratory Distress Syndrome Renal Transplant Recipients With ESKAPE/rESKAPE Pneumonia

BACKGROUND

A sustained immunosuppressive state in renal transplant recipients is a factor that can contribute to increased incidence of acute respiratory distress syndrome (ARDS) due to pneumonia. ARDS renal recipients with ESKAPE (E. faecium, S. aureus, K. pneumoniae, A. baumannii, P. aeruginosa, and Enterobacter spp.) pneumonia are probably related to high morbidity and mortality. We therefore sought to investigate the frequency of ESKAPE and resistant ESKAPE (rESKAPE) pathogens isolated from respiratory tract specimens of renal recipients with ARDS and determine the risk factors for mortality.

METHODS

A retrospective analysis of ARDS renal recipients with ESKAPE/rESKAPE pneumonia was reviewed. Multiple logistic regression analysis was conducted to identify the independent risk factors associated with infection-related mortality.

RESULTS

During the study period, 88 ESKAPE pathogens obtained from respiratory tract specimens of 54 ARDS renal recipients were documented including 33 A. baumannii, 24 P. aeruginosa, 17 S. aureus, 6 K. pneumoniae, 8 Enterobacter species, and 0 E. Faecium. Among these ESKAPE organisms, 61.4% (54/88) were antimicrobial resistant. The risk factors for mortality independently associated with ARDS renal recipients with ESKAPE pneumonia were severe ARDS (odds ratio [OR] 4.3 (95% confidence interval [CI] 1.1-16.4), P = .032), serum creatinine level >1.5 mg/dL (OR 4.2 95% CI (1.0-17.9), P = .05) and body temperature less than 38°C (OR 5.0 (95% CI 1.3-19.6), P = .02) at ARDS onset. The independent determinants of mortality were associated with ARDS renal recipients with rESKAPE pneumonia were serum creatinine level >1.5 mg/dL (OR 13.7, 95% CI 1.3-142.1, P = .028) and body temperature less than 38°C (OR 5.5 (95% CI 1.1-26.6) at ARDS onset, P = .035).

CONCLUSIONS

The majority of EPKAPE isolates were antimicrobial resistant. Mortality in ARDS renal recipients with ESKAPE/rESKAPE pneumonia was associated with the severity of ARDS, elevated serum creatinine level, or depressed febrile response at ARDS onset.

Risk Factors for Bloodstream Infection After Living-donor Liver Transplantation in Children

BACKGROUND

Postoperative bloodstream infection (BSI) is the most important determinant of recipient morbidity and mortality after liver transplantation (LT). Children who underwent LT are at the highest risk of developing BSI because of the significant surgical intervention, use of multiple devices, and administration of immunosuppressive agents. However, information regarding the risk factors for BSI in children after LT is limited.

METHODS

We retrospectively reviewed 210 children who underwent living-donor LT at the largest pediatric LT center in Japan. Patients' characteristics, blood culture results and clinical outcomes were extracted from electronic medical records. Univariate and multivariate analyses were performed to identify the risk factors for BSI.

RESULTS

Among the 210 LT recipients, 53 (25%) recipients experienced 86 episodes of BSI during the observational period. The source of the BSI was identified only in 38%: catheter-related BSI (27%) peritonitis (7%), urinary tract infection (2%), pneumonia (1%) and infectious endocarditis (1%). A multivariate analysis demonstrated that body weight (P = 0.03), volume of blood loss during LT (P < 0.001) and cytomegalovirus (CMV) antigenemia positivity (P = 0.04) were independently associated with the development of BSI. The risk factors for BSI differed when we analyzed the subjects according to age (≤24 months and >24 months), blood loss and pediatric end-stage liver disease/model for end-stage liver disease versus positive CMV antigenemia.

CONCLUSIONS

The volume of blood loss, postoperative CMV antigenemia positivity and body weight were associated with the development of BSI after LT in pediatric living-donor recipients. To identify the age-specific predictors of BSI in children who underwent LT, age-specific analyses are crucial.

Factors influencing mortality in solid organ transplant recipients with bloodstream infection

Although bloodstream infection (BSI) is a major cause of mortality after solid organ transplantation, information regarding its prognostic factors is scarce. To identify risk factors for 30-day mortality in solid organ transplant (SOT) recipients with BSI, we prospectively recorded all episodes of BSI occurring in adult SOT recipients from January 2007 to October 2014 at a university hospital. We identified 361 consecutive episodes of BSI involving 246 patients. The 30-day case-fatality rate from the onset of BSI was 11.4%. Factors independently associated with 30-day mortality in a logistic regression analysis were shock at presentation (OR 13.658; 95% CI 5.985-31.168), acute graft rejection in the previous 6 months (OR 3.681; 95% CI 1.059-12.795), and a platelet count of <50,000 × 10(9)/L (OR 3.070; 95% CI 1.173-8.038). Kidney recipients were the patients with the best prognosis (OR 0.375; 95% CI 0.156-0.900). Our findings may help to identify SOT recipients with BSI who are at the highest risk of death.

Staphylococcus aureus bacteremias following liver transplantation: a clinical analysis of 20 cases

BACKGROUND

To describe the incidence, clinical characteristics, and outcomes of Staphylococcus aureus bacteremia after liver transplantation and investigate the drug resistance of S. aureus to frequently used antibiotics to provide evidence for clinical prevention and therapy.

MATERIALS AND METHODS

In a double-center retrospective study, blood cultures positive for S. aureus were obtained from January 1, 2001 to December 31, 2014. The BACTEC 9120 blood culture system and the Vitek-2 system were used to process blood samples and identify species, respectively. We also collected these patients' data to confirm clinical and laboratory characteristics.

RESULTS

Twenty of 275 (7.3%) liver recipients developed S. aureus bacteremia during the study period. The median time to the onset of S. aureus bacteremias was 6 days after liver transplantation and all episodes of bacteremias were early onset. The lung was the most common source of primary infection, followed by the intra-abdominal/biliary tract. A total of nine (45%) liver recipients died due to S. aureus bacteremias. Of these 20 S. aureus cases, 80% were methicillin-resistant. S. aureus was highly resistant to erythromycin and penicillin (resistance rate >90%). No S. aureus resistant to glycopeptides and oxazolidone antibiotics was observed. There were seven (35%) liver recipients with an inappropriate antibiotic therapy. Between the periods of 2001-2007 and 2008-2014, the distribution of methicillin-resistant S. aureus was not significantly different (P=1.000). Pneumonia as a predominant primary source, a high body temperature, abnormal blood pressure, and decreased platelets, which occurred in the early period after liver transplantation, as well as high morbidity and mortality, were the main characteristics of S. aureus bacteremias.

CONCLUSION

S. aureus led to severe bacteremias in liver recipients, with high morbidity and mortality, and the majority of them comprised methicillin-resistant S. aureus.

Distribution and resistance of pathogens in liver transplant recipients with Acinetobacter baumannii infection

BACKGROUND

Drug-resistant Acinetobacter baumannii has become a major problem in liver transplant recipients. The aim of this study was to investigate the clinical presentation, distribution, and drug susceptibility characteristics in liver recipients with A. baumannii infection.

METHODS

We retrospectively investigated 17 liver recipients who developed A. baumannii infection between January 1, 2007 and December 31, 2014. The distribution of A. baumannii and drug susceptibility characteristics were reviewed.

RESULTS

Infectious complications due to A. baumannii appeared in 17 liver recipients, with a total of 24 episodes. Approximately 63% (15/24) of A. baumannii infections occurred within 2 weeks after transplantation. The most common source of infection was multiple culture-positive sites (35.3%, n=6), followed by the intra-abdominal/biliary tract (23.5%, n=4) and lung (23.5%, n=4). Eight patients (47.1%) had a body temperature of 38°C or higher at the onset of A. baumannii infection. Nine, seven, and 12 recipients had a serum creatinine level of >1.5 mg/dL, a white blood cell count of >15,000/mm(3), and a platelet count of <50,000/mm(3), respectively. There were five (29.4%) cases of septic shock and eight (47.1%) deaths. The rate of antibiotic resistance of A. baumannii to ten of 12 antibiotics investigated was more than 60%. Among the 24 infections caused by A. baumannii, 75% were carbapenem-resistant. The rods were relatively sensitive to tigecycline and cefoperazone-sulbactam.

CONCLUSION

The clinical manifestations of A. baumannii infection included a high body temperature, a decreased platelet count, an elevated white blood cell count, and onset in the early period after transplantation as well as high mortality. The antibiotic resistance rate of A. baumannii was extremely high. Prevention measures and combination antibiotic therapy are needed to improve the outcomes of liver recipients with A. baumannii infections.

Distribution and resistance of pathogens in liver transplant recipients with Acinetobacter baumannii infection

BACKGROUND

Drug-resistant Acinetobacter baumannii has become a major problem in liver transplant recipients. The aim of this study was to investigate the clinical presentation, distribution, and drug susceptibility characteristics in liver recipients with A. baumannii infection.

METHODS

We retrospectively investigated 17 liver recipients who developed A. baumannii infection between January 1, 2007 and December 31, 2014. The distribution of A. baumannii and drug susceptibility characteristics were reviewed.

RESULTS

Infectious complications due to A. baumannii appeared in 17 liver recipients, with a total of 24 episodes. Approximately 63% (15/24) of A. baumannii infections occurred within 2 weeks after transplantation. The most common source of infection was multiple culture-positive sites (35.3%, n=6), followed by the intra-abdominal/biliary tract (23.5%, n=4) and lung (23.5%, n=4). Eight patients (47.1%) had a body temperature of 38°C or higher at the onset of A. baumannii infection. Nine, seven, and 12 recipients had a serum creatinine level of >1.5 mg/dL, a white blood cell count of >15,000/mm(3), and a platelet count of <50,000/mm(3), respectively. There were five (29.4%) cases of septic shock and eight (47.1%) deaths. The rate of antibiotic resistance of A. baumannii to ten of 12 antibiotics investigated was more than 60%. Among the 24 infections caused by A. baumannii, 75% were carbapenem-resistant. The rods were relatively sensitive to tigecycline and cefoperazone-sulbactam.

CONCLUSION

The clinical manifestations of A. baumannii infection included a high body temperature, a decreased platelet count, an elevated white blood cell count, and onset in the early period after transplantation as well as high mortality. The antibiotic resistance rate of A. baumannii was extremely high. Prevention measures and combination antibiotic therapy are needed to improve the outcomes of liver recipients with A. baumannii infections.

Risk factors for mortality in liver transplant recipients with ESKAPE infection

BACKGROUND

Although infections caused by the pathogens Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp (ESKAPE) have recently been identified as serious emerging problems in solid organ transplant, no information in liver transplant (LT) recipients is available. We sought to investigate the risk factors for associated mortality in LT recipients with ESKAPE infections.

METHODS

A retrospective analysis of infection after LT was reviewed. Risk factors for mortality caused by ESKAPE infection were identified.

RESULTS

Fifty-three episodes of infections caused by ESKAPE were documented in 51 LT recipients. The main sites of infection were the bloodstream (49.0%), the lungs (33.3%), and the intra-abdominal/biliary tract (17.6%). The risk factors for mortality independently associated with ESKAPE infection were female sex (odds ratio [OR] = 6.6, 95% confidence interval [CI] = 1.1-40.8, P = .042), septic shock (OR = 30.1, 95% CI = 3.7-244.8, P = .001), and lymphocyte counts <300/mm(3) (OR = 20.2, 95% CI = 2.9-142.2, P = .003).

CONCLUSIONS

To improve the results of LT, more effective therapeutic treatments are of paramount importance when female LT recipients with ESKAPE infection present with septic shock and decreased lymphocyte counts.

Bloodstream infections among solid organ transplant recipients: epidemiology, microbiology, associated risk factors for morbility and mortality

Bloodstream infections (BSIs) remain important causes of morbidity and mortality among solid organ transplant (SOT) recipients and still threaten the success of SOT. In general, among SOT recipients, risk factors for BSIs are associated with prior ICU admission, catheterization, older recipient or donor age…etc. Pulmonary focus, nosocomial source of BSIs, lack of appropriate antibiotic therapy and other variables have significant impacts on BSIs-related mortality in SOT. Most of BSIs in SOT are caused by gram-negative bacteria. However, all aspects including microbiological spectrum, morbidity and mortality rates, risk factors of BSIs and BSIs-related death depend on the type of transplantation. The purpose of this review is to summarize the epidemiology, microbiologic features including antimicrobial resistance of organisms, and associated risk factors for morbidity and mortality of BSIs according to different type of transplantation to better understand the characteristics of BSIs and improve the outcomes after SOT.

[Nosocomial infection in patients receiving a solid organ transplant or haematopoietic stem cell transplant]

Bacterial infections are the most common infections in solid organ transplant recipients. These infections occur mainly in the first month after transplantation and are hospital-acquired. Nosocomial infections cause significant morbidity and are the most common cause of mortality in this early period of transplantation. These infections are caused by multi-drug resistant (MDR) microorganisms, mainly Gram-negative enterobacteria, non-fermentative Gram-negative bacilli, enterococci, and staphylococci. The patients at risk of developing nosocomial bacterial infections are those previously colonized with MDR bacteria while on the transplant waiting list. Intravascular catheters, the urinary tract, the lungs, and surgical wounds are the most frequent sources of infection. Preventive measures are the same as those applied in non-immunocompromised, hospitalized patients except in patients at high risk for developing fungal infection. These patients need antifungal therapy during their hospitalization, and for preventing some bacterial infections in the early transplant period, patients need vaccinations on the waiting list according to the current recommendations. Although morbidity and mortality related to infectious diseases have decreased during the last few years in haematopoietic stem cell transplant recipients, they are still one of the most important complications in this population. Furthermore, as occurs in the general population, the incidence of nosocomial infections has increased during the different phases of transplantation. It is difficult to establish general preventive measures in these patients, as there are many risk factors conditioning these infections. Firstly, they undergo multiple antibiotic treatments and interventions; secondly, there is a wide variability in the degree of neutropenia and immunosuppression among patients, and finally they combine hospital and home stay during the transplant process. However, some simple measures could be implemented to improve the current situation.