Transmission of methicillin-resistant Staphylococcus aureus infection through solid organ transplantation: confirmation via whole genome sequencing

Positive donor blood cultures are not associated with worse heart transplant survival

BACKGROUND

Recent evidence has demonstrated that transplantation of hearts with blood culture positive donors (BCPDs) to pediatric recipients is safe and effective. Few studies have analyzed the effect of BCPD on adult heart transplant recipients.

METHODS

The United Network for Organ Sharing (UNOS) database was retrospectively reviewed from September, 1987 to March, 2021. Exclusion criteria included pediatric donors/recipients, donor ejection fraction <10% or >85%, inactive listed recipients, donors missing blood cultures, and recipients missing follow-up time. Outcomes were compared with fully adjusted logistic models. To account for discrepancies in BCPD and non-BCPD covariates, an inverse proportionally weighted model with regression adjustment (IPWRA) was used.

RESULTS

A total of 60 592 donors were non-BCPD, while 4009 were BCPD. 7% of hearts not transplanted were BCPD, while 6% of hearts transplanted were BCPD (p = .001). These rates have been nearly constant since 2005. There were no differences in short term survival between the two groups in the adjusted or IPWRA models (p = .103 and .277, respectively). Additionally, the BCPD group had longer ischemic time (3.24 vs. 3.06 h, p < .001), older donor age (32.73 vs. 31.65 years, p < .001), and older recipient age (52.76 vs. 52.09 years, p = .001). The IPWRA revealed an average additional 3.4 years of overall survival and 2.25 years of graft function for BCPD versus non-BCPD recipients, although these results failed to reach statistical significance (p = .387 and .527, respectively).

CONCLUSIONS

Given the need for more donor hearts, donors with positive blood cultures should be considered. Great care in evaluating such patients is advised to eliminate donors with untreated infections, while carefully selected donors can be considered and used.

Epidemiology and Prevention of Early Infections by Multi-Drug-Resistant Organisms in Adults Undergoing Liver Transplant: A Narrative Review

Invasive bacterial infections are a leading cause of morbidity and mortality after liver transplant (LT), especially during the first months after LT, and infections due to multi-drug-resistant organisms (MDRO) are increasing in this setting. Most of the infections in patients in intensive care unit arise from the endogenous microflora and, for this reason, pre-LT MDRO rectal colonization is a risk factor for developing MDRO infections in the post-LT. Moreover, the transplanted liver may carry an increased risk of MDRO infections due to organ transportation and preservation, to donor intensive care unit stay and previous antibiotic exposure. To date, little evidence is available about how MDRO pre-LT colonization in donors and recipients should address LT preventive and antibiotic prophylactic strategies, in order to reduce MDRO infections in the post-LT period. The present review provided an extensive overview of the recent literature on these topics, with the aim to offer a comprehensive insight about the epidemiology of MDRO colonization and infections in adult LT recipients, donor-derived MDRO infections, possible surveillance, and prophylactic strategies to reduce post-LT MDRO infections.

Deceased donors with multidrug-resistant organisms: implications and future directions

PURPOSE OF REVIEW

Organ utilization from donors infected or colonized with multidrug-resistant organisms (MDROs) remains inconsistent, and hesitancy to accept organs from these donors may relate to poor outcomes among solid organ transplant recipients with MDRO donor-derived infections (DDIs). An improved understanding of the risk factors for donor MDRO colonization or infection and the risk of MDRO DDI is needed to safely expand the donor pool while minimizing unnecessary organ discard.

RECENT FINDINGS

Recent studies have begun to delineate risk factors for MDRO acquisition among deceased donors and the epidemiology of MDRO DDIs, but additional efforts are warranted to inform optimal approaches to donor evaluation, risk stratification, management, interfacility and interagency data sharing, and approaches to recipient management.

SUMMARY

This review summaries recent data regarding risk factors for MDRO colonization and infection in deceased donors, epidemiology of MDRO DDIs, and current approaches to donors harboring MDROs and provides a framework for future research and collaboration.

Machine perfusion combined with antibiotics prevents donor-derived infections caused by multidrug-resistant bacteria

Donor infection affects organ utilization, especially the infections by multidrug-resistant bacteria, which may have disastrous outcomes. We established a rat model, inoculated with Escherichia coli or carbapenem-resistant Klebsiella pneumoniae (CRKP), to investigate whether hypothermic machine perfusion (HMP), normothermic machine perfusion (NMP), or static cold storage (SCS) combined with antibiotic (AB) could eliminate the bacteria. E. coli or CRKP-infected kidneys were treated with cefoperazone-sulbactam and tigecycline, respectively. The HMP+AB and NMP+AB treatments had significant therapeutic effects on E. coli or CRKP infection compared with the SCS+AB treatment. The bacterial load of CRKP-infected kidneys in the HMP+AB (22 050 ± 2884 CFU/g vs. 1900 ± 400 CFU/g, p = .007) and NMP+AB groups (25 433 ± 2059 CFU/g vs. 500 ± 458 CFU/g, p = .002) were significantly reduced, with no statistically significant difference between both groups. Subsequently, the CRKP-infected kidneys of the HMP+AB and SCS+AB groups were transplanted. The rats in the SCS+AB group were severe infected and euthanized on day 4 post-transplant. By contrast, the rats in the HMP+AB group were in good condition. In conclusion, HMP and NMP combined with AB seems to be efficient approaches to decrease bacterial load of infected kidneys. This might lead to higher utilization rates of donors with active infection.

Solid Organ Transplantation From Deceased Donors With Infective Endocarditis: The UK Experience

BACKGROUND

There is little evidence regarding the use of organs from deceased donors with infective endocarditis. We performed a retrospective analysis of the utilization, safety, and long-term survival of transplants from donors with infective endocarditis in the United Kingdom.

METHODS

We studied deceased donor transplants over an 18-y period (2001-2018) using data from the UK Transplant Registry. We estimated the risk of infection transmission, defined as a microbiological isolate in the recipient matching the causative organism in the donor in the first 30 days posttransplant. We examined all-cause allograft failure up to 5 years in kidney and liver recipients, comparing transplants from donors with endocarditis with randomly selected matched control transplants.

RESULTS

We studied 88 transplants from 42 donors with infective endocarditis. We found no cases of infection transmission. There was no difference in allograft failure between transplants from donors with infective endocarditis and matched control transplants, among either kidney (hazard ratio, 1.48; 95% CI, 0.66-3.34) or liver (hazard ratio, 1.14; 95% CI, 0.54-2.41) recipients. Compared with matched controls, donors with infective endocarditis donated fewer organs (2.3 versus 3.2 organs per donor; P < 0.001) and were less likely to become kidney donors (odds ratio, 0.29; 95% CI, 0.16-0.55).

CONCLUSIONS

We found acceptable safety and long-term allograft survival in transplants from selected donors with infective endocarditis in the United Kingdom. This may have implications for donor selection and organ utilization.

Impact of donor multidrug-resistant organisms on solid organ transplant recipient outcomes

BACKGROUND

The impact of donor colonization or infection with multidrug-resistant organisms (MDROs) on solid organ transplant (SOT) recipient outcomes remains uncertain. We thus evaluated the association between donor MDROs and risk of posttransplant infection, graft failure, and mortality.

METHODS

A multicenter retrospective cohort study was performed. All SOT recipients with a local deceased donor were included. The cohort was divided into three exposure groups: recipients whose donors had (1) an MDRO, (2) a non-MDRO bacterial or candidal organism, or (3) no growth on cultures. The primary outcomes were (1) bacterial or invasive candidal infection within 3 months and (2) graft failure or death within 12 months posttransplant. Mixed effect multivariable frailty models were developed to evaluate each association.

RESULTS

Of 658 total SOT recipients, 93 (14%) had a donor with an MDRO, 477 (73%) had a donor with a non-MDRO organism, and 88 (13%) had a donor with no organisms on culture. On multivariable analyses, donor MDROs were associated with a significantly increased hazard of infection compared to those with negative donor cultures (adjust hazard ratio [aHR] 1.63, 95% CI 1.01-2.62, p = .04) but were not associated with graft failure or death (aHR 0.45, 95% CI 0.15-1.36, p = .16).

CONCLUSIONS

MDROs on donor culture increase the risk of early posttransplant infection but do not appear to affect long-term graft or recipient survival, suggesting organ donors with MDROs on culture may be safely utilized. Future studies aimed at reducing early posttransplant infections associated with donor MDROs are needed.

Kidney Transplantation From Deceased Donors With Bloodstream Infection: A Multicenter Retrospective Study

BACKGROUND

The use of organs from donors with infection is limited because of the possibility of transmission. We aimed to investigate the transmission after deceased donor transplantation with bloodstream infection (BSI).

METHODS

A retrospective study of patients undergoing kidney or pancreas transplantation at five tertiary centers in Korea from January 2009 and November 2019 was performed. We analyzed the outcomes after transplantation from deceased donors with BSI.

RESULTS

Eighty-six recipients received transplantation from 69 donors with BSI. The most common isolated pathogens from donors were Gram-positive bacteria (72.0%), followed by Gram-negative bacteria (22.7%), and fungi (5.3%). Appropriate antimicrobial agents were used in 47.8% of donors before transplantation. Transmission occurred only in 1 of 83 recipients (1.2%) from bacteremic donors and 1 of 6 recipients (16.7%) from fungemic donors. One-year patient and graft survival was 97.5%and 96.3%, respectively. There was no significant difference in graft and patient survival between patients who received organs from infected donors and noninfected donors.

CONCLUSION

Using organs from donors with bacteremia seems to be a safe option with low transmission risk. The overall prognosis of using organs from donors with BSI is favorable.

Ten years of donor-derived disease: A report of the disease transmission advisory committee

Despite clinical and laboratory screening of potential donors for transmissible disease, unexpected transmission of disease from donor to recipient remains an inherent risk of organ transplantation. The Disease Transmission Advisory Committee (DTAC) was created to review and classify reports of potential disease transmission and use this information to inform national policy and improve patient safety. From January 1, 2008 to December 31, 2017, the DTAC received 2185 reports; 335 (15%) were classified as a proven/probable donor transmission event. Infections were transmitted most commonly (67%), followed by malignancies (29%), and other disease processes (6%). Forty-six percent of recipients receiving organs from a donor that transmitted disease to at least 1 recipient developed a donor-derived disease (DDD). Sixty-seven percent of recipients developed symptoms of DDD within 30 days of transplantation, and all bacterial infections were recognized within 45 days. Graft loss or death occurred in about one third of recipients with DDD, with higher rates associated with malignancy transmission and parasitic and fungal diseases. Unexpected DDD was rare, occurring in 0.18% of all transplant recipients. These findings will help focus future efforts to recognize and prevent DDD.

Challenges and New Therapeutic Approaches in the Management of Chronic Wounds

Chronic non-healing wounds are estimated to cost the US healthcare $28-$31 billion per year. Diabetic ulcers, arterial and venous ulcers, and pressure ulcers are some of the most common types of chronic wounds. The burden of chronic wounds continues to rise due to the current epidemic of obesity and diabetes and the increase in elderly adults in the population who are more vulnerable to chronic wounds than younger individuals. This patient population is also highly vulnerable to debilitating infections caused by opportunistic and multi-drug resistant pathogens. Reduced microcirculation, decreased availability of cytokines and growth factors that promote wound closure and healing, and infections by multi-drug resistant and biofilm forming microbes are some of the critical factors that contribute to the development of chronic non-healing wounds. This review discusses novel approaches to understand chronic wound pathology and methods to improve chronic wound care, particularly when chronic wounds are infected by multi-drug resistant, biofilm forming microbes.

Molecular Detection and PCR-RFLP Analysis of Mucoviscosity-Associated Gene A (magA) in Clinical Isolates of Multidrug-Resistant Klebsiella pneumoniae in Bangladesh

Background and Objective:

The mucoviscosity associated gene A (magA) in the hypermucoviscous variants of K. pneumoniae is reported to be associated with invasive infections and considered a virulence factor. We sought to analyze the magA genes in K. pneumoniae isolates in the clinical specimen collected from Bangladesh.

Methods:

We established a multicenter cohort of patients with Klebsiella infection hospitalized at 05 different hospitals between September 2016 and April 2017. We collected 313 K. pneumoniae isolates from patients who consented to participate in the study. The isolates were evaluated for harboring the magA genes using a single-tube multiplexed polymerase chain reaction. The magA genes were analyzed by PCR-RFLP technique using two enzymes, namely PciI and SmaI. Antibiogram assay using 12 commercially available antibiotic discs was performed on all the isolates.

Results:

The presence of K. pneumoniae specific gene (ureD) was confirmed in all the isolates. The percentage of isolates harboring the magA gene was 7.34%(23 isolates), the majority of which was collected from the patients admitted in intensive care units (16 isolates, 69.6%), and infectious diseases wards (5 isolates, 21.7%). PCR-RFLP analysis revealed that for 7 out of 23 isolates, where Sma1 could not cleave the magA gene. All the isolates showed resistance to ampicillin, carbenicillin cefradine, chloramphenicol, erythromycin, kanamycin, and sulphamethoxazole, though the extent was varying. However, imipenem showed 100% sensitivity to all the tested isolates.

Conclusion:

This study demonstrates the presence of the magA gene in multidrug-resistant clinical isolates of K. pneumoniae collected from Bangladesh.

Screening of donors and recipients for infections prior to solid organ transplantation

PURPOSE OF REVIEW

This review is a brief overview of current guidelines on screening donors and candidates for bacterial, fungal, parasitic and viral infections prior to solid organ transplantation. The pretransplant period is an important time to evaluate infection exposure risk based on social history as well as to offer vaccinations.

RECENT FINDINGS

One of the major changes in the past few years has been increased utilization of increased Public Health Service risk, HIV positive, and hepatitis C-positive donors. There has also been increased attention to donor and recipient risks for geographically associated infections, such as endemic fungal infections and flaviviruses.

SUMMARY

Screening for donors and candidates prior to organ transplantation can identify and address infection risks. Diagnosing infections in a timely manner can help guide treatment and additional testing. Use of necessary prophylactic treatment in organ recipients can prevent reactivation of latent infections and improve posttransplant outcomes.

Donor-derived bacterial infections in lung transplant recipients in the era of multidrug resistance

OBJECTIVES

Our aim was to analyze the prevalence of multidrug-resistant bacterial infections in lung transplant donors and to evaluate its influence on donor-derived bacterial infections.

METHODS

We conducted a retrospective study of adult patients who underwent lung transplantation (2013-2016) at our hospital. Donor-derived bacterial infection was defined as the isolation of the same bacteria with identical antibiotic susceptibility patterns in the recipient and the perioperative cultures from the donor during the first month posttransplantation. We utilized a preventive antibiotic strategy adapted to the bacteria identified in donor cultures using systemic and nebulized antibiotics.

RESULTS

252 lung transplant recipients and 243 donors were included. In 138/243 (56.8%) donors, one bacterial species was isolated from at least one sample; graft colonization (118/243; 48.6%), blood cultures (5/243; 2.1%) and the contamination of preservation fluids (56/243; 23%). Multidrug-resistant bacteria were isolated from 12/243 (4.9%) donors; four Enterobacterales, four Stenotrophomonas maltophilia, three Pseudomonas aeruginosa and one methicillin-resistant Staphylococcus aureus. There was no transmission of these multidrug-resistant bacteria. Donor-derived infections, primarily tracheobronchitis due to non-MDR bacteria, were diagnosed in 7/253 (2.9%) recipients, with good clinical outcomes.

CONCLUSIONS

The lungs of donors colonized with multidrug-resistant bacteria may be safely used when recipients receive prompt tailored antibiotic treatment.

Methicillin-resistant Staphylococcus aureus in solid organ transplantation-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the American Society of Transplantation Infectious Diseases Community of Practice review the epidemiology, diagnosis, prevention, and management of methicillin-resistant Staphylococcus aureus (MRSA) infections in solid organ transplantation. Despite an increasing armamentarium of antimicrobials active against MRSA, improved diagnostic tools, and overall declining rates of infection, MRSA infections remain a substantial cause of morbidity and mortality in solid organ transplant recipients. Pre- and post-transplant MRSA colonization is a significant risk factor for post-transplant MRSA infection. The preferred initial treatment of MRSA bacteremia remains vancomycin. Hand hygiene, chlorhexidine bathing in the ICU, central-line bundles that focus on reducing unnecessary catheter use, disinfection of patient equipment, and the environment along with antimicrobial stewardship are all aspects of an infection prevention approach to prevent MRSA transmission and decrease healthcare-associated infections.

Infectious Disease Transmission in Solid Organ Transplantation: Donor Evaluation, Recipient Risk, and Outcomes of Transmission

In 2016, the Transplantation Society of Australia and New Zealand, with the support of the Australian Government Organ and Tissue authority, commissioned a literature review on the topic of infectious disease transmission from deceased donors to recipients of solid organ transplants. The purpose of this review was to synthesize evidence on transmission risks, diagnostic test characteristics, and recipient management to inform best-practice clinical guidelines. The final review, presented as a special supplement in Transplantation Direct, collates case reports of transmission events and other peer-reviewed literature, and summarizes current (as of June 2017) international guidelines on donor screening and recipient management. Of particular interest at the time of writing was how to maximize utilization of donors at increased risk for transmission of human immunodeficiency virus, hepatitis C virus, and hepatitis B virus, given the recent developments, including the availability of direct-acting antivirals for hepatitis C virus and improvements in donor screening technologies. The review also covers emerging risks associated with recent epidemics (eg, Zika virus) and the risk of transmission of nonendemic pathogens related to donor travel history or country of origin. Lastly, the implications for recipient consent of expanded utilization of donors at increased risk of blood-borne viral disease transmission are considered.

A Case Report: Organs From a Donor With Highly Virulent Zoonotic Outbreak Strain of Streptococcus agalactiae Serotype III, Multilocus Sequence Type 283 Infective Endocarditis Did Not Result in Transmission With Adequate Prophylactic Antibiotic Cover

In 2015, an outbreak involving a highly virulent zoonotic outbreak strain of Streptococcus agalactiae serotype III, multilocus sequence type 283 occurred in Singapore with increased neurologic complications, septic arthritis, and spinal infections in healthier patients. We report a case of a successful dual kidney transplant from a deceased donor with infective endocarditis and disseminated infection with the same strain of S agalactiae and we review the current literature.

Review of Infectious Disease Prophylaxis in Solid Organ Transplantation

As immunosuppressive therapy has evolved over the years, rejection rates in solid organ transplant have declined, but infections remain a significant cause of morbidity and mortality in this population. Prophylaxis against bacterial, viral, and fungal infections is often used to prevent infection from common pathogens during high-risk periods. As an integral part of the multidisciplinary medical team, it is important that nurses caring for transplant recipients be familiar with methods to detect and prevent infectious diseases in this population. This article presents a review of risk factors for and prevalence of common infectious pathogens, as well as important considerations regarding prophylactic medications in solid organ transplant recipients.

Donor-derived infections among Chinese donation after cardiac death liver recipients

AIM

To investigate blood cultures of deceased donors and report the confirmed transmission of bacterial infection from donors to liver recipients.

METHODS

We retrospectively studied the results of blood cultures among our donation after cardiac death (DCD) donors and calculated the donor-derived bacterial infection rates among liver recipients. Study participants underwent liver transplantation between January 1, 2010 and February 1, 2017. The study involved a total of 67 recipients of liver grafts from 67 DCD donors. We extracted the data of donors’ and patients’ characteristics, culture results and clinical outcomes, especially the post-transplant complications in liver recipients, from electronic medical records. We analyzed the characteristics of the donors and the corresponding liver recipients with emphasis put on donor-derived infections.

RESULTS

Head trauma was the most common origin of death among our 67 DCD donors (46.3%). Blood taken prior to the procurement operation was cultured for 53 of the donors, with 17 episodes of bloodstream infections developing from 13 donors. The predominant organism isolated from the blood of donors was Gram-positive bacteria (70.6%). Only three (4.5%) of 67 liver recipients developed confirmed donor-derived bacterial infections, with two isolates of multidrug-resistant Klebsiella pneumoniae and one isolate of multidrug-resistant Enterobacter aerogenes. The liver recipients with donor-derived infections showed relation to higher crude mortality and graft loss rates (33.3% each) within 3 mo post transplantation, as compared to those without donor-derived infections (9.4% and 4.7%, respectively). All three liver recipients received appropriate antimicrobial therapy.

CONCLUSION

Liver recipients have high occurrence of donor-derived infections. The liver recipients with donor-derived multidrug-resistant Enterobacteriaceae infections can have good outcome if appropriate antimicrobial therapy is given.

Confirmed Transmission of Bacterial or Fungal Infection to Kidney Transplant Recipients from Donated After Cardiac Death (DCD) Donors in China: A Single-Center Analysis

Background

We aimed to investigate blood and urine cultures of donated after cardiac death (DCD) donors and report the cases of confirmed (proven/probable) transmission of bacterial or fungal infection from donors to kidney recipients.

Material/Methods

Seventy-eight DCD donors between 2010 and 2016 were included. Sixty-one DCD donors underwent blood cultures and 22 episodes of bacteremias developed in 18 donors. Forty-three donors underwent urine cultures and 14 donors experienced 17 episodes of urinary infections.

Results

Seven of 154 (4.5%) kidney recipients developed confirmed donor-derived bacterial or fungal infections. Inappropriate use of antibiotics in donor was a risk factor for donor-derived infection (p=0.048). The use of FK506 was more frequent in recipients without donor-derived infection than those with donor-derived infection (p=0.033). Recipients with donor-derived infection were associated with higher mortality and graft loss (42.9% and 28.6%, respectively), when compared with those without donor-derived infection (4.8% each). Three kidney recipients with donor-derived infection died; one death was due to multi-organ failure caused by Candida albicans, and two were related to rupture of the renal artery; two of them did not receive appropriate antimicrobial therapy after infection.

Conclusions

Our kidney recipients showed high occurrence rates of donor-derived infection. Recipients with donor-derived infection were associated with higher mortality and graft loss than those without donor-derived infection. The majority of recipients with donor-derived infection who died did not receive appropriate antimicrobial therapy after infection.

Whole genome SNP typing to investigate methicillin-resistant Staphylococcus aureus carriage in a health-care provider as the source of multiple surgical site infections

BACKGROUND

Prevention of nosocomial transmission of infections is a central responsibility in the healthcare environment, and accurate identification of transmission events presents the first challenge. Phylogenetic analysis based on whole genome sequencing provides a high-resolution approach for accurately relating isolates to one another, allowing precise identification or exclusion of transmission events and sources for nearly all cases. We sequenced 24 methicillin-resistant Staphylococcus aureus (MRSA) genomes to retrospectively investigate a suspected point source of three surgical site infections (SSIs) that occurred over a one-year period. The source of transmission was believed to be a surgical team member colonized with MRSA, involved in all surgeries preceding the SSI cases, who was subsequently decolonized. Genetic relatedness among isolates was determined using whole genome single nucleotide polymorphism (SNP) data.

RESULTS

Whole genome SNP typing (WGST) revealed 283 informative SNPs between the surgical team member's isolate and the closest SSI isolate. The second isolate was 286 and the third was thousands of SNPs different, indicating the nasal carriage strain from the surgical team member was not the source of the SSIs. Given the mutation rates estimated for S. aureus, none of the SSI isolates share a common ancestor within the past 16 years, further discounting any common point source for these infections. The decolonization procedures and resources spent on the point source infection control could have been prevented if WGST was performed at the time of the suspected transmission, instead of retrospectively.

CONCLUSIONS

Whole genome sequence analysis is an ideal method to exclude isolates involved in transmission events and nosocomial outbreaks, and coupling this method with epidemiological data can determine if a transmission event occurred. These methods promise to direct infection control resources more appropriately.

KlebSeq, a Diagnostic Tool for Surveillance, Detection, and Monitoring of Klebsiella pneumoniae

Health care-acquired infections (HAIs) kill tens of thousands of people each year and add significantly to health care costs. Multidrug-resistant and epidemic strains are a large proportion of HAI agents, and multidrug-resistant strains of Klebsiella pneumoniae, a leading HAI agent, have caused an urgent public health crisis. In the health care environment, patient colonization by K. pneumoniae precedes infection, and transmission via colonization leads to outbreaks. Periodic patient screening for K. pneumoniae colonization has the potential to curb the number of HAIs. In this report, we describe the design and validation of KlebSeq, a highly informative screening tool that detects Klebsiella species and identifies clinically important strains and characteristics by using highly multiplexed amplicon sequencing without a live-culturing step. We demonstrate the utility of this tool on several complex specimen types, including urine, wound swabs and tissue, and several types of respiratory and fecal specimens, showing K. pneumoniae species and clonal group identification and antimicrobial resistance and virulence profiling, including capsule typing. Use of this amplicon sequencing tool to screen patients for Klebsiella carriage could inform health care staff of the risk of infection and outbreak potential. KlebSeq also serves as a model for next-generation molecular tools for public health and health care, as expansion of this tool can be used for several other HAI agents or applications.

Multidrug-resistant organisms in liver transplant: Mitigating risk and managing infections

Liver transplant (LT) recipients are vulnerable to infections with multidrug-resistant (MDR) pathogens. Risk factors for colonization and infection with resistant bacteria are ubiquitous and unavoidable in transplantation. During the past decade, progress in transplantation and infection prevention has contributed to the decreased incidence of infections with methicillin-resistant Staphylococcus aureus. However, even in the face of potentially effective antibiotics, vancomycin-resistant enterococci continue to plague LT. Gram-negative bacilli prove to be more problematic and are responsible for high rates of both morbidity and mortality. Despite the licensure of novel antibiotics, there is no universal agent available to safely and effectively treat infections with MDR gram-negative organisms. Currently, efforts dedicated toward prevention and treatment require involvement of multiple disciplines including transplant providers, specialists in infectious diseases and infection prevention, and researchers dedicated to the development of rapid diagnostics and safe and effective antibiotics with novel mechanisms of action. Liver Transplantation 22 1143-1153 2016 AASLD.

Genomics of Natural Populations of Staphylococcus aureus

Staphylococcus aureus is a major human pathogen and an important cause of livestock infections. The first S. aureus genomes to be published, 15 years ago, provided the first view of genome structure and gene content. Since then, thousands of genomes from a wide array of strains from different sources have been sequenced. Comparison of these sequences has resulted in broad insights into population structure, bacterial evolution, clone emergence and expansion, and the molecular basis of niche adaptation. Furthermore, this information is now being applied clinically in outbreak investigations to inform infection control measures and to determine appropriate treatment regimens. In this review, we summarize some of the broad insights into S. aureus biology gained from the analysis of genomes and discuss future directions and opportunities in this dynamic field of research.

Multidrug-Resistant Bacterial Donor-Derived Infections in Solid Organ Transplantation

Although rare, donor-derived infections (DDIs) caused by multidrug-resistant (MDR) bacteria can have devastating consequences for organ transplant recipients. Recognition of MDR bacterial DDIs can be challenging, as MDR bacteria are prevalent in most hospitals and distinguishing their transmission through transplantation from other, more typical routes of acquisition are difficult. New technologies such as whole genome sequencing have recently proven to be a powerful advance in the investigation of MDR bacterial DDIs. Once recognized, the optimal treatment of MDR bacterial DDIs is not clear. Herein, we review the clinical manifestations, outcomes, and management of MDR bacterial DDIs, and identify areas of uncertainty toward which the transplant community should direct further research efforts.

Donor-Derived Infections: Incidence, Prevention, and Management

Organ donors reflect the diverse US population, and there are an increasing number of donors born in, who have resided in, or who have traveled to underdeveloped areas of the world or areas with geographically restricted infections. As such, these donors are exposed to pathogens that can potentially be transmitted to recipients of the donor’s organs. Additionally, there are newer techniques to identify many pathogens that may be transmitted from the donor to the transplant recipients. Finally, high-profile reports of several donor-derived infections have heightened awareness of donor-derived infections and have likely contributed to increased recognition. In this chapter, the incidence, methods of identification and prevention, and management of unexpected donor-derived infections will be reviewed.

Whole genome sequencing in clinical and public health microbiology

SummaryGenomics and whole genome sequencing (WGS) have the capacity to greatly enhance knowledge and understanding of infectious diseases and clinical microbiology.

The growth and availability of bench-top WGS analysers has facilitated the feasibility of genomics in clinical and public health microbiology.

Given current resource and infrastructure limitations, WGS is most applicable to use in public health laboratories, reference laboratories, and hospital infection control-affiliated laboratories.

As WGS represents the pinnacle for strain characterisation and epidemiological analyses, it is likely to replace traditional typing methods, resistance gene detection and other sequence-based investigations (e.g., 16S rDNA PCR) in the near future.

Although genomic technologies are rapidly evolving, widespread implementation in clinical and public health microbiology laboratories is limited by the need for effective semi-automated pipelines, standardised quality control and data interpretation, bioinformatics expertise, and infrastructure.