Inadequate antibiotic therapy in solid organ transplant recipients is associated with a higher mortality rate

Investigating infectious outcomes in adult patients undergoing solid organ transplantation: A retrospective single-center experience, Paris, France

OBJECTIVES

This study described the demographic characteristics, clinical presentation, treatment, and outcomes of solid organ transplant recipients who were admitted to our center for infection. It also determined factors associated with a poor outcome, and compares early and late period infections.

METHODS

In this retrospective observational study, conducted at a tertiary care center in France between October 2017 and March 2019, infectious outcomes of patients with solid organ transplant where studied.

RESULTS

A total of 104 patients were included with 158 hospitalizations for infection. Among these 104 patients, 71 (68%) were men. The median age was 59 years old. The most common symptoms on admission were fever (66%) and chills (31%). Lower respiratory tract infections were the most common diagnosis (71/158 hospitalizations). Urinary tract infections were frequently seen in kidney transplant recipients (25/60 hospitalizations). One or more infectious agents were isolated for 113 hospitalizations (72%): 70 bacteria, 36 viruses and 10 fungi, with predominance of gram-negative bacilli (53 cases) of which 13 were multidrug-resistant. The most frequently used antibiotics were third generation cephalosporins (40 cases), followed by piperacillin-tazobactam (26 cases). We note that 25 infections (16%) occurred during the first 6 months (early post-transplant period). Patients admitted during the early post-transplant period were more often on immunosuppressive treatment with prednisone (25/25 VS 106/133) (p = 0.01), mycophenolic acid (22/25 VS 86/133) (p = 0.03), presented for an urinary tract infection (10/25 VS 25/133) (p = 0.04) or a bacterial infection (17/25 VS 53/133) (p = 0.01). Patients with later infection had more comorbidities (57/83 VS 9/21) (p = 0.03), cancer (19/83 VS 0/21) (p = 0.04) or were on treatment with everolimus (46/133 VS 0/25) (p = 0.001). During 31 hospitalizations (20%), patients presented with a serious infection requiring intensive care (n = 26; 16%) or leading to death (n = 7; 4%). Bacteremia, pulmonary and cardiac complications were the main risk factors associated with poor outcome.

CONCLUSION

Infections pose a significant challenge in the care of solid organ transplant patients, particularly those with comorbidities and intensive immunosuppression. This underscores the crucial importance of continuous surveillance and epidemiologic monitoring within this patient population.

Antimicrobial Peptides: The Production of Novel Peptide-Based Therapeutics in Plant Systems

The increased prevalence of antibiotic resistance is alarming and has a significant impact on the economies of emerging and underdeveloped nations. The redundancy of antibiotic discovery platforms (ADPs) and injudicious use of conventional antibiotics has severely impacted millions, across the globe. Potent antimicrobials from biological sources have been extensively explored as a ray of hope to counter the growing menace of antibiotic resistance in the population. Antimicrobial peptides (AMPs) are gaining momentum as powerful antimicrobial therapies to combat drug-resistant bacterial strains. The tremendous therapeutic potential of natural and synthesized AMPs as novel and potent antimicrobials is highlighted by their unique mode of action, as exemplified by multiple research initiatives. Recent advances and developments in antimicrobial discovery and research have increased our understanding of the structure, characteristics, and function of AMPs; nevertheless, knowledge gaps still need to be addressed before these therapeutic options can be fully exploited. This thematic article provides a comprehensive insight into the potential of AMPs as potent arsenals to counter drug-resistant pathogens, a historical overview and recent advances, and their efficient production in plants, defining novel upcoming trends in drug discovery and research. The advances in synthetic biology and plant-based expression systems for AMP production have defined new paradigms in the efficient production of potent antimicrobials in plant systems, a prospective approach to countering drug-resistant pathogens.

Solid organ transplant-specific antibiogram in a tertiary pediatric hospital in Canada

SOT recipients are more vulnerable to infections with antimicrobial-resistant organisms, and therefore, it may be useful for transplant centers to create transplant-specific antibiograms to direct empirical antimicrobial regimens and monitor trends in antimicrobial resistance. SOT-specific antibiograms were created using antimicrobial susceptibility data on isolates from 2012 to 2018 at The Hospital for Sick Children, Toronto, Ontario, Canada. The CLSI guidelines were followed to generate the antibiograms except that results from 2 years of data were pooled on a rolling basis to achieve larger sample sizes. The 3 most frequent organisms in one analysis period of the SOT antibiogram were Escherichia coli (average sample size ±standard deviation; n = 28.7 ± 3.8), Staphylococcus aureus (n = 27.8 ± 5.0), and Pseudomonas aeruginosa (non-CF) (n = 19.8 ± 8.8). For E.coli, susceptibilities in the SOT antibiogram were significantly lower than those in the hospital-wide antibiogram in 2017-2018 for ampicillin (27% vs 47%; p = .014), piperacillin/tazobactam (55% vs 88%; p < .001), cefotaxime (59% vs 89%; p < .001), ciprofloxacin (71% vs 88%; p = .007), and trimethoprim-sulfamethoxazole (41% vs 69%; p = .001), but not significantly different for aminoglycosides and meropenem. In the SOT antibiogram of E. coli, decreased susceptibility trend was confirmed in some antibiotics, including piperacillin/tazobactam (83% in 2012-2013 vs 55% in 2017-2018). At our center, the solid organ transplant-specific antibiogram revealed important differences in E. coli susceptibilities and trends in antimicrobial resistance. Developing a SOT antibiogram will assist in revising and improving empiric treatment guidelines as well as monitoring antimicrobial resistance in this population.

Antibiotic-Resistant Infections and Treatment Challenges in the Immunocompromised Host: An Update

This article reviews antibiotic resistance and treatment of bacterial infections in the growing number of patients who are immunocompromised: solid organ transplant recipients, the neutropenic host, and persons with human immunodeficiency virus and AIDS. Specific mechanisms of resistance in both gram-negative and gram-positive bacteria, as well as newer treatment options are addressed elsewhere and are only briefly discussed in the context of the immunocompromised host.

Antimicrobial peptides: new hope in the war against multidrug resistance

The discovery of antibiotics marked a golden age in the revolution of human medicine. However, decades later, bacterial infections remain a global healthcare threat, and a return to the pre-antibiotic era seems inevitable if stringent measures are not adopted to curb the rapid emergence and spread of multidrug resistance and the indiscriminate use of antibiotics. In hospital settings, multidrug resistant (MDR) pathogens, including carbapenem-resistant Pseudomonas aeruginosa, vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and extended-spectrum β-lactamases (ESBL) bearing Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae are amongst the most problematic due to the paucity of treatment options, increased hospital stay, and exorbitant medical costs. Antimicrobial peptides (AMPs) provide an excellent potential strategy for combating these threats. Compared to empirical antibiotics, they show low tendency to select for resistance, rapid killing action, broad-spectrum activity, and extraordinary clinical efficacy against several MDR strains. Therefore, this review highlights multidrug resistance among nosocomial bacterial pathogens and its implications and reiterates the importance of AMPs as next-generation antibiotics for combating MDR superbugs.

Antibiotic-Resistant Infections and Treatment Challenges in the Immunocompromised Host

This article reviews antibiotic resistance and treatment of bacterial infections in the growing number of patients who are immunocompromised: solid organ transplant recipients, the neutropenic host, and persons with human immunodeficiency virus and AIDS. Specific mechanisms of resistance in both gram-negative and gram-positive bacteria, as well as newer treatment options are addressed elsewhere, and are only briefly discussed in the context of the immunocompromised host.

Colonization with extended-spectrum beta-lactamase-producing Enterobacteriaceae in solid organ transplantation: A meta-analysis and review

BACKGROUND

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) may cause severe infections, often preceded by ESBL-E gastrointestinal (GI) colonization.

METHODS

We conducted a review of the literature, investigating the prevalence of ESBL-E GI colonization in solid organ transplant (SOT) patients and the risk for subsequent ESBL-E infection. We searched the PubMed and EMBASE databases (to April 1, 2016) looking for studies that contained data on ESBL-E colonization among transplant patients.

RESULTS

Of 341 non-duplicate citations, four studies reporting data on 1089 patients fulfilled our inclusion criteria. Among them, the pooled prevalence for ESBL-E colonization was 18% (95% confidence interval [CI] 5%-36%). Stratifying by transplant type, we identified an ESBL-E colonization rate of 17% (95% CI 3%-39%) among liver transplant recipients and 24% (single report) among kidney transplant recipients.

CONCLUSIONS

Among SOT patients, approximately one in five patients is colonized with ESBL-E, although this finding may be skewed by reporting bias from centers with high ESBL-E prevalence. ESBL-E screening in SOT patients should be considered and evaluated in future studies.

Clinical and microbiological epidemiology of early and late infectious complications among solid-organ transplant recipients requiring hospitalization

There is limited literature describing the clinical and microbiological characteristics of solid-organ transplant recipients requiring hospitalization for infectious complications. This study reports on the rate and timing of these syndromes and describes the associated microbiological epidemiology. This prevalence cohort study evaluated solid-organ transplant recipients requiring hospitalization during 2007-2011. We reported infectious complications requiring hospitalization in 603 of 1414 readmissions at a rate of 0.43 episodes per 1000 transplant-days (95% CI, 0.40-0.47), with 85% occurring >6 months post-transplantation. The most frequent infectious complications were as follows: respiratory (27%), sepsis or bacteremia (13%), liver or biliary tract (12%), genitourinary (12%), and cytomegalovirus related (9%). Approximately 53% presented without fever, 45% had no pathogen isolated, and multidrug-resistant organisms were isolated in 27% of those with an identified microbiological etiology. Infectious-related complications continue to pose a high clinical burden on our acute care center, with the majority occurring in the late transplant period. Clinicians are faced with the difficult task of prescribing adequate antimicrobial therapy.

Solid organ transplant patients: are there opportunities for antimicrobial stewardship?

OBJECTIVE

Rising incidence of Clostridium difficile and multidrug-resistant organisms' infections and a dwindling development of new antimicrobials are an impetus for antimicrobial stewardship in organ transplant recipients. We sought to understand antimicrobial prescribing practices and identify opportunities for interdisciplinary collaboration among the transplant, antimicrobial stewardship, and infectious diseases teams.

METHODS

In 2013, two assessors conducted four real-time audits on all antimicrobial therapy in transplant patients, assessing each regimen against stewardship principles established by the Centers for Disease Prevention and Control, supplemented by applicable transplant-specific infection guidelines. Chi-square test was used to compare stewardship-concordant and stewardship-discordant audit results relative to transplant infectious diseases consultation.

RESULTS

Analysis was performed on 176 audits. Fifty-eight percent (103/176) received at least one antimicrobial, of which 69.9% (72/103) were stewardship-concordant. Infections were confirmed or suspected in 52.3% (92/176). Of those, 98.9% (91/92) received antimicrobials, and 41.8% (38/91) were prescribed by transplant clinicians. Infectious diseases consultation was associated with more stewardship-concordant prescriptions (78.5% vs. 59.6%, p = 0.03). The most common stewardship-discordant categories were lack of de-escalation, empiric antimicrobial spectrum being too broad, and therapy duration being too long.

CONCLUSIONS

Opportunities exist for antimicrobial stewardship in transplant recipients, especially those who do not require infectious diseases consultation.

Rapid identification of pathogens using molecular techniques

Real-time PCR is the traditional face of nucleic acid detection in the diagnostic microbiology laboratory and is now generally regarded as robust enough to be widely adopted. Methods based on nucleic acid detection of this type are bringing increased accuracy to diagnosis in areas where culture is difficult and/or expensive, and these methods are often effective partners to other rapid molecular diagnostic tools such as matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS). This change in practice has particularly affected the recognition of viruses and fastidious or antibiotic-exposed bacteria, but has been also shown to be effective in the recognition of troublesome or specialised phenotypes such as antiviral resistance and transmissible antibiotic resistance in the Enterobacteriaceae. Quantitation and high-intensity sequencing (of multiple whole genomes) has brought new opportunities as well as new challenges to the microbiology community. Diagnostic microbiologists currently training might be expected to deal less with the culture-based techniques of the last half-century than with the high-volume data and complex analyses of the next.

Sepsis in standard care: patients' characteristics, effectiveness of antimicrobial therapy and patient outcome--a cohort study

PURPOSE

Fast diagnosis and initiation of appropriate antibiotic therapy is pivotal for the survival of sepsis patients. However, most studies on suspected sepsis patients are conducted in the intensive care unit or in the emergency room setting, neglecting the standard care setting. This study evaluated sepsis risk factors, microbiological accurateness of the initial empiric antimicrobial therapy and its effect on hospital mortality in standard care patients.

METHODS

In this prospective observational cohort study, patients with clinically suspected sepsis meeting two or more SIRS criteria were screened on standard care wards. After hospital discharge, occurrence of an infection was assessed according to standardized criteria, and empirical antibiotic therapy was evaluated using antibiograms of recognized pathogens by expert review.

RESULTS

Of the 2384 screened patients, 298 fulfilled two or more SIRS criteria. Among these were 28.2 % SIRS patients without infection, 46.3 % non-bacteremic/fungemic sepsis patients and 25.5 % bacteremic/fungemic sepsis patients. Occurrence of a malignant disease and chills were associated with a higher risk of patients having bacteremic/fungemic sepsis, whereas other described risk factors remained insignificant. In total, 91.1 % of suspected sepsis patients received empirical antimicrobial therapy, but 41.1 % of bacteremic sepsis patients received inappropriate therapy. Non-surviving bacteremic sepsis patients received a higher proportion of inappropriate therapy than those who survived (p = 0.022).

CONCLUSIONS

A significant proportion of bacteremic sepsis patients receive inappropriate empiric antimicrobial therapy. Our results indicate that rapid availability of microbiological results is vital, since inappropriate antimicrobial therapy tended to increase the hospital mortality of sepsis patients.

Impact of infectious disease consultation on the clinical and economic outcomes of solid organ transplant recipients admitted for infectious complications

BACKGROUND

There has been a paucity of data on the healthcare resource utilization of infectious disease-related complications in solid organ transplant recipients. The aims of this study were to report the clinical and economic burden of infectious disease-related complications, along with the impact of infectious disease consultation.

METHODS

This cohort study evaluated patients requiring admission to a tertiary-care center during 2007, 2008, and 2011. Propensity score matching was used to estimate the effects of patient demographics, comorbidities, and transplant- and infection-related factors on 28-day hospital survival, length of stay (LOS), and medical costs.

RESULTS

Infectious disease-related complications occurred in 603 of 1414 (43%) admissions in 306 of 531 (58%) patients. Unadjusted 28-day mortality did not differ between those who received infectious disease consultations vs those who did not (2.9% vs 3.6%, P = .820), however, after propensity score matching, infectious disease consultation resulted in significantly greater 28-day survival estimates (hazard ratio = 0.33; log-rank P = .026), and reduced 30-day rehospitalization rates (16.9% vs 23.9%, P = .036). The median LOS and hospitalization costs were significantly increased for patients receiving an infectious disease consultation than in those managed by the attending team alone (7.0 vs 5.0 days, P = .002, and $9652 vs $6192, P = .003). However, the median LOS (5.5 vs 5.1 days, P = .31) and hospitalization costs ($8106 vs $6912, P = .63) did not differ significantly among those receiving an early infectious disease consultation (<48 hours) vs no consultation, respectively.

CONCLUSIONS

Infectious disease consultation in recipients of solid organ transplant is associated with increased LOS and hospitalization costs but decreased mortality and reduced rehospitalization rates. Early consultation with infectious disease specialists decreases healthcare resource utilization compared with delayed referrals.

Trauma after transplant: hold the antibiotics please

OBJECTIVE

Despite the increase in transplantation and the prevalence of trauma as a major disease entity, few data exist about transplant patients who suffer trauma. We conducted a study to determine whether transplant patients (TP) have worse outcomes, particularly of infections, than do their non-transplant (NTP) counterparts after trauma.

METHODS

We performed a retrospective review of trauma patients from 2006 to 2010. All patients who had undergone organ transplantation were included and compared through 1:3 propensity matching with their NTP counterparts. Data for the groups were compared to determine differences in outcomes.

RESULTS

The review included 17 TP (13 kidney, 2 liver, 1 kidney/liver, and 1 kidney/pancreas) as compared with 51 NTP. The patients were matched for injury severity score (ISS), age, and gender, with most suffering blunt trauma (82.4% [14/17] TP vs. 90% [46/51] NTP, p = 0.5). The groups had similar initial Glasgow Coma Scale (GCS) scores (13.2 ± 4.5 TP vs. 13.9 ± 2.5 NTP, p=0.6), serum lactate concentrations (2.0 ± 1.8 mmol/L TP vs. 2.3 ± 1.5 mmol/L NTP, p=0.39), and base deficits (-1.5 ± 4.0 TP vs. 0.6 ± 3.0 NTP, p=0.21). Comorbidities were more common in the TP than in the NTP group. The groups had similar lengths of stay (days on ventilator: 0.1 ± 0.3 TP vs. 0.4 ± 1.6 NTP, p=0.9; days in ICU: 0.2 ± 0.6 TP vs. 2.4 ± 5.9 NTP, p=0.16; days in hospital: 5.2 ± 6.8 TP vs. 7.5 ± 10.2 NTP, p=0.86), and two deaths occurred in each of the two groups (p=0.26). Overall complications were similar (52.94% [9/17] TP vs. 62.75% [32/51] NTP, p=0.57), and there were only two infections, both in the NTP group (p=1.0). Antibiotics were given to 59% of the TP vs. 39% of the NTP, with an average duration of 8.4 days for the TP vs. 3.9 days for the NTP.

CONCLUSION

When matched equally for degree of injury, the TP and NTP had similar outcomes. There also appeared to be no differences in infectious complications in the two groups, yet more of the TP had exposure to more days of antibiotics. Similar protocols of antimicrobial therapy should apply to both TP and NTP to avoid the overuse of antimicrobial agents and ensure maintenance of the susceptibility patterns of pathogens.