Current state and future directions for veterinary antimicrobial resistance research

Antimicrobial resistance (AMR) is a critical One Health concern with implications for human, animal, plant, and environmental health. Antimicrobial susceptibility testing (AST), antimicrobial resistance testing (ART), and surveillance practices must be harmonized across One Health sectors to ensure consistent detection and reporting practices. Veterinary diagnostic laboratory stewardship, clinical outcomes studies, and training for current and future generations of veterinarians and laboratorians are necessary to minimize the spread of AMR and move veterinary medicine forward into an age of better antimicrobial use practices. The purpose of this article is to describe current knowledge gaps present in the literature surrounding ART, AST, and clinical or surveillance applications of these methods and to suggest areas where AMR research can fill these knowledge gaps. The related Currents in One Health by Maddock et al, JAVMA, March 2024, addresses current limitations to the use of genotypic ART methods in clinical veterinary practice.

Outcomes associated with empiric cefepime for bloodstream infections caused by ceftriaxone-resistant, cefepime-susceptible Escherichia coli and Klebsiella pneumoniae

BACKGROUND

Cefepime is a first-line agent for empiric sepsis therapy; however, cefepime use may be associated with increased mortality for extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) in an MIC-dependent manner. This study aimed to compare the efficacy of empiric cefepime versus meropenem for bloodstream infections (BSI) caused by ceftriaxone-resistant Escherichia coli and Klebsiella pneumoniae with cefepime MICs ≤ 2 mg/L.

METHODS

This single-center retrospective cohort study included patients admitted from October 2010 to August 2020 who received cefepime or meropenem empirically for sepsis with a blood culture growing ceftriaxone-resistant Escherichia coli or Klebsiella pneumoniae. The primary outcome was 30-day mortality; secondary endpoints included 14-day mortality, recurrent BSI, readmission and recurrent infection within 90 days, time to clinical resolution of infection, time to clinical stability, and clinical stability at 48 hours.

RESULTS

Fifty-four patients met inclusion criteria: 36 received meropenem and 18 received cefepime. The median (IQR) treatment durations of cefepime and meropenem were 3 (2-6) days and 7 (5-10) days, respectively. Thirty-day and 14-day mortality were similar between cefepime and meropenem (11.1% vs. 2.8%; P = 0.255 and 5.6% vs. 2.8%; P = 1.00, respectively). Cefepime was associated with longer time to clinical stability compared with meropenem (median 38.48 hours vs. 21.26; P = 0.016).

CONCLUSION

Mortality was similar between groups, although most patients who received cefepime empirically were ultimately transitioned to a carbapenem to complete the full treatment course. Empiric cefepime was associated with a delay in achieving clinical stability when compared with meropenem to treat BSI caused by ceftriaxone-resistant Enterobacterales, even when cefepime-susceptible.

Search, identification, and curation of cell and gene therapy product regulations using augmented intelligent systems

Background

Manually keeping up-to-date with regulations such as directives, guidance, laws, and ordinances related to cell and gene therapy is a labor-intensive process. We used machine learning (ML) algorithms to create an augmented intelligent system to optimize systematic screening of global regulations to improve efficiency and reduce overall labor and missed regulations.

Methods

Combining Boolean logic and artificial intelligence (i.e., augmented intelligence) for the search process, ML algorithms were used to identify and suggest relevant cell and gene therapy regulations. Suggested regulations were delivered to a landing page for further subject matter expert (SME) tagging of words/phrases to provide system relevance on functional words. Ongoing learning from the repository regulations continued to increase system reliability and performance. The automated ability to train and retrain the system allows for continued refinement and improvement of system accuracy. Automated daily searches for applicable regulations in global databases provide ongoing opportunities to update the repository.

Results

Compared to manual searching, which required 3-4 SMEs to review ~115 regulations, the current system performance, with continuous system learning, requires 1 full-time equivalent to process approximately 9,000 regulations/day. Currently, system performance has 86% overall accuracy, a recommend recall of 87%, and a reject recall of 84%. A conservative search strategy is intentionally used to permit SMEs to assess low-recommended regulations in order to prevent missing any applicable regulations.

Conclusion

Compared to manual searches, our custom automated search system greatly improves the management of cell and gene therapy regulations and is efficient, cost effective, and accurate.

1228. Outcomes Associated with Empiric Cefepime or Meropenem for Bloodstream Infections Caused by Ceftriaxone-Resistant, Cefepime-Susceptible Escherichia coli and Klebsiella pneumoniae

Background

Cefepime is a 4^th generation cephalosporin frequently used for empiric sepsis therapy. Dose- and MIC-dependent efficacy of cefepime is supported by the Clinical & Laboratory Standards Institute, however its use in infections due to extended-spectrum beta-lactamase-producing Enterobacterales is controversial. This study aims to compare outcomes in patients given empiric meropenem or cefepime for bloodstream infections (BSI) caused by ceftriaxone-resistant E. coli and K. pneumoniae.

Methods

This single-center retrospective cohort included adults hospitalized from 2010 - 2020 and received empiric cefepime or meropenem for BSI caused by ceftriaxone-resistant E. coli or K. pneumoniae. In the cefepime group, only organisms with MIC ≤ 2 mg/L were included. Patients who received the empiric agent for < 48 hours, or received an additional active agent within 48 hours were excluded. The primary outcome was 30-day mortality; secondary outcomes were recurrent infection, readmission, and time to clinical stability. Chi-squared or Fisher’s exact was used for categorical variables and Mann-Whitney-U for continuous variables. Inverse probability treatment weighing was used to determine the impact of empirical therapy on clinical stability at 48 hours.

Results

Fifty-four patients were included: 36 received empiric meropenem, 18 received cefepime. There were no significant differences in baseline severity of illness or comorbid conditions. Urinary source was less common in the meropenem group compared to cefepime (52.8 vs 83.8%, p=0.028) (Table 1). There was no difference in 30-day mortality between meropenem and cefepime (2.8 vs 11.1%, p = 0.255). More patients achieved clinical stability at 48 hours on empiric meropenem compared to cefepime (75 vs 44.4%, p = 0.027), and time to clinical stability was significantly shorter (median 21.3 vs 38.5 hours, p = 0.016). Most patients in the meropenem and cefepime groups completed definitive treatment with a carbapenem (88.9 vs 72.2%, p=0.142).

Table 1: Results

Summary of primary and secondary outcomes

Conclusion

There was no difference in mortality between patients receiving empiric cefepime for BSI due to ceftriaxone-resistant Enterobacterales, with cefepime MIC ≤ 2 mg/L, compared to meropenem; however, time to clinical stability was significantly delayed.

Disclosures

James Kirby, MD, D(ABMM), First Light Biosciences (Board Member)TECAN, Inc. (Research Grant or Support)

Development of the Wheat Practical Haplotype Graph Database as a Resource for Genotyping Data Storage and Genotype Imputation

To improve the efficiency of high-density genotype data storage and imputation in bread wheat (Triticum aestivum L.), we applied the Practical Haplotype Graph (PHG) tool. The Wheat PHG database was built using whole-exome capture sequencing data from a diverse set of 65 wheat accessions. Population haplotypes were inferred for the reference genome intervals defined by the boundaries of the high-quality gene models. Missing genotypes in the inference panels, composed of wheat cultivars or recombinant inbred lines genotyped by exome capture, genotyping-by-sequencing (GBS), or whole-genome skim-seq sequencing approaches, were imputed using the Wheat PHG database. Though imputation accuracy varied depending on the method of sequencing and coverage depth, we found 92% imputation accuracy with 0.01× sequence coverage, which was slightly lower than the accuracy obtained using the 0.5× sequence coverage (96.6%). Compared to Beagle, on average, PHG imputation was ∼3.5% (P-value < 2 × 10⁻¹⁴) more accurate, and showed 27% higher accuracy at imputing a rare haplotype introgressed from a wild relative into wheat. We found reduced accuracy of imputation with independent 2× GBS data (88.6%), which increases to 89.2% with the inclusion of parental haplotypes in the database. The accuracy reduction with GBS is likely associated with the small overlap between GBS markers and the exome capture dataset, which was used for constructing PHG. The highest imputation accuracy was obtained with exome capture for the wheat D genome, which also showed the highest levels of linkage disequilibrium and proportion of identity-by-descent regions among accessions in the PHG database. We demonstrate that genetic mapping based on genotypes imputed using PHG identifies SNPs with a broader range of effect sizes that together explain a higher proportion of genetic variance for heading date and meiotic crossover rate compared to previous studies.

An approach for high-resolution genetic mapping of distant wild relatives of bread wheat: example of fine mapping of Lr57 and Yr40 genes

The article reports a powerful but simple approach for high-resolution mapping and eventual map-based cloning of agronomically important genes from distant relatives of wheat, using the already existing germplasm resources. Wild relatives of wheat are a rich reservoir of genetic diversity for its improvement. The effective utilization of distant wild relatives in isolation of agronomically important genes is hindered by the lack of recombination between the homoeologous chromosomes. In this study, we propose a simple yet powerful approach that can be applied for high-resolution mapping of a targeted gene from wheat's distant gene pool members. A wheat-Aegilops geniculata translocation line TA5602 with a small terminal segment from chromosome 5 M^g of Ae. geniculata translocated to 5D of wheat contains genes Lr57 and Yr40 for leaf rust and stripe rust resistance, respectively. To map these genes, TA5602 was crossed with a susceptible Ae. geniculata 5 M^g addition line. Chromosome pairing between the 5 M^g chromosomes of susceptible and resistant parents resulted in the development of a high-resolution mapping panel for the targeted genes. Next-generation-sequencing data from flow-sorted 5 M^g chromosome of Ae. geniculata allowed us to generate 5 M^g-specific markers. These markers were used to delineate Lr57 and Yr40 genes each to distinct ~ 1.5 Mb physical intervals flanked by gene markers on 5 M^g. The method presented here will allow researchers worldwide to utilize existing germplasm resources in genebanks and seed repositories toward routinely performing map-based cloning of important genes from tertiary gene pools of wheat.

Abstract 2623: Investigation into factors influencing probability of success in oncology clinical trials and trends over time

The regulatory approval process for new therapies in oncology involves costly clinical trials that can span multiple years and historically have had a low probability of success. To derive estimates of the probability of success and other related risk characteristics in oncology clinical trials, we searched Informa Pharma Intelligence's Trialtrove and Pharmaprojects databases for oncology-specific drug-indication programs between 2001 and 2020. In total, we identified 10,083 oncology-specific drug-indication programs, which included 2,800 therapeutic agents (excluding biosimilars) tested across 98 indications. The features we considered included indication and indication group, clinical phase, follow-on indication status, presence and type of patient selection biomarker, drug modality, and accelerated approval status. In several cases, clinical success rates were higher than the benchmark oncology historical average of the phase 1 to approval success rate of 4.1% found in our sample set. For example, the use of pre-selection biomarkers in early clinical development was associated with a greater than two-fold increase in probability of approval from phase 1. Moreover, drugs with prior approvals in another indication were more than three times more likely to be successful from phase 1 than a candidate targeting a novel mechanism. In addition, we found that monoclonal antibodies were numerically more successful than other modalities in the historical data, while oncolytic viruses, vaccines, and bispecific antibodies have been less successful. In all cases, concomitant with the emergence of genomic technologies, an improved scientific understanding of cancer biology, and an evolving regulatory environment that includes a higher number of accelerated approvals, success rates in oncology have improved during the time period of this analysis and particularly in the past 5 years.

Citation Format: Mary Jane Hinrichs, Shomesh E. Chaudhuri, Robert Bowden, Andrew W. Lo, David W. Jenkins. Investigation into factors influencing probability of success in oncology clinical trials and trends over time [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2623.

Diamondites: evidence for a distinct tectono-thermal diamond-forming event beneath the Kaapvaal craton

The petrogenesis and relationship of diamondite to well-studied monocrystalline and fibrous diamonds are poorly understood yet would potentially reveal new aspects of how diamond-forming fluids are transported through the lithosphere and equilibrate with surrounding silicates. Of 22 silicate- and oxide-bearing diamondites investigated, most yielded garnet intergrowths (n = 15) with major element geochemistry (i.e. Ca-Cr) classifying these samples as low-Ca websteritic or eclogitic. The garnet REE patterns fit an equilibrium model suggesting the diamond-forming fluid shares an affinity with high-density fluids (HDF) observed in fibrous diamonds, specifically on the join between the saline-carbonate end-members. The δ¹³C values for the diamonds range from - 5.27 to - 22.48‰ (V-PDB) with δ¹⁸O values for websteritic garnets ranging from + 7.6 to + 5.9‰ (V-SMOW). The combined C-O stable isotope data support a model for a hydrothermally altered and organic carbon-bearing subducted crustal source(s) for the diamond- and garnet-forming media. The nitrogen aggregation states of the diamonds require that diamondite-formation event(s) pre-dates fibrous diamond-formation and post-dates most of the gem monocrystalline diamond-formation events at Orapa. The modelled fluid compositions responsible for the precipitation of diamondites match the fluid-poor and fluid-rich (fibrous) monocrystalline diamonds, where all grow from HDFs within the saline-silicic-carbonatitic ternary system. However, while the nature of the parental fluid(s) share a common lithophile element geochemical affinity, the origin(s) of the saline, silicic, and/or carbonatitic components of these HDFs do not always share a common origin. Therefore, it is wholly conceivable that the diamondites are evidence of a distinct and temporally unconstrained tectono-thermal diamond-forming event beneath the Kaapvaal craton.

Genome-Wide Association Study for Identification and Validation of Novel SNP Markers for Sr6 Stem Rust Resistance Gene in Bread Wheat

Stem rust (caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn.), is a major disease in wheat (Triticum aestivium L.). However, in recent years it occurs rarely in Nebraska due to weather and the effective selection and gene pyramiding of resistance genes. To understand the genetic basis of stem rust resistance in Nebraska winter wheat, we applied genome-wide association study (GWAS) on a set of 270 winter wheat genotypes (A-set). Genotyping was carried out using genotyping-by-sequencing and ∼35,000 high-quality SNPs were identified. The tested genotypes were evaluated for their resistance to the common stem rust race in Nebraska (QFCSC) in two replications. Marker-trait association identified 32 SNP markers, which were significantly (Bonferroni corrected P < 0.05) associated with the resistance on chromosome 2D. The chromosomal location of the significant SNPs (chromosome 2D) matched the location of Sr6 gene which was expected in these genotypes based on pedigree information. A highly significant linkage disequilibrium (LD, r2 ) was found between the significant SNPs and the specific SSR marker for the Sr6 gene (Xcfd43). This suggests the significant SNP markers are tagging Sr6 gene. Out of the 32 significant SNPs, eight SNPs were in six genes that are annotated as being linked to disease resistance in the IWGSC RefSeq v1.0. The 32 significant SNP markers were located in nine haplotype blocks. All the 32 significant SNPs were validated in a set of 60 different genotypes (V-set) using single marker analysis. SNP markers identified in this study can be used in marker-assisted selection, genomic selection, and to develop KASP (Kompetitive Allele Specific PCR) marker for the Sr6 gene.

HIGHLIGHTS

Novel SNPs for Sr6 gene, an important stem rust resistant gene, were identified and validated in this study. These SNPs can be used to improve stem rust resistance in wheat.

Genome-Wide Association Study for Identification and Validation of Novel SNP Markers for Sr6 Stem Rust Resistance Gene in Bread Wheat

Stem rust (caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn.), is a major disease in wheat (Triticum aestivium L.). However, in recent years it occurs rarely in Nebraska due to weather and the effective selection and gene pyramiding of resistance genes. To understand the genetic basis of stem rust resistance in Nebraska winter wheat, we applied genome-wide association study (GWAS) on a set of 270 winter wheat genotypes (A-set). Genotyping was carried out using genotyping-by-sequencing and ∼35,000 high-quality SNPs were identified. The tested genotypes were evaluated for their resistance to the common stem rust race in Nebraska (QFCSC) in two replications. Marker-trait association identified 32 SNP markers, which were significantly (Bonferroni corrected P < 0.05) associated with the resistance on chromosome 2D. The chromosomal location of the significant SNPs (chromosome 2D) matched the location of Sr6 gene which was expected in these genotypes based on pedigree information. A highly significant linkage disequilibrium (LD, r² ) was found between the significant SNPs and the specific SSR marker for the Sr6 gene (Xcfd43). This suggests the significant SNP markers are tagging Sr6 gene. Out of the 32 significant SNPs, eight SNPs were in six genes that are annotated as being linked to disease resistance in the IWGSC RefSeq v1.0. The 32 significant SNP markers were located in nine haplotype blocks. All the 32 significant SNPs were validated in a set of 60 different genotypes (V-set) using single marker analysis. SNP markers identified in this study can be used in marker-assisted selection, genomic selection, and to develop KASP (Kompetitive Allele Specific PCR) marker for the Sr6 gene.

HIGHLIGHTS

Novel SNPs for Sr6 gene, an important stem rust resistant gene, were identified and validated in this study. These SNPs can be used to improve stem rust resistance in wheat.

Mapping of Quantitative Trait Loci for Leaf Rust Resistance in the Wheat Population Ning7840 × Clark

Leaf rust, caused by Puccinia triticina, is an important fungal disease of wheat (Triticum aestivum L.) and causes significant yield losses worldwide. To determine quantitative trait loci (QTLs) responsible for leaf rust resistance, a recombinant inbred line (RIL) population developed from a cross of Ning7840 × Clark was evaluated for leaf rust severity, and was genotyped for single nucleotide polymorphisms (SNPs) using 9K Illumina chips, and with simple sequence repeat (SSR) markers. Two major QTLs on chromosome arms 7DS and 3BS, and two minor QTLs on chromosomes 5AS and 6AS showed a significant effect on leaf rust severity. The 7DS QTL from Ning7840 and the 3BS QTL from Clark explained, respectively, about 35% and 18% of the phenotypic variation for leaf rust resistance. The QTL on 7DS was confirmed to be Lr34. The QTL on 3BS, QLr.hwwg-3B.1, was associated with adult plant resistance and was provisionally identified as Lr74. QLr.hwwg-5AS and QLr.hwwg-6AS from Ning7840 and Clark, respectively, may correspond to previously described QTLs. Lr34, QLr.hwwg-3BS.1, and QLr.hwwg-6AS had an additive effect on leaf rust severity. RILs with all three favorable alleles showed the highest resistance to leaf rust and the RILs with none of them showed the lowest resistance.

Ecologically and geologically relevant isotope signatures of C, N, and S: okenone producing purple sulfur bacteria Part I

Purple sulfur bacteria (PSB) are known to couple the carbon, nitrogen, and sulfur cycling in euxinic environments. This is the first study with multiple strains and species of okenone-producing PSB to examine the carbon (C), nitrogen (N), and sulfur (S) metabolisms and isotopic signatures in controlled laboratory conditions, investigating what isotopic fractionations might be recorded in modern environments and the geologic record. PSB play an integral role in the ecology of euxinic environments and produce the unique molecular fossil okenane, derived from the diagenetic alteration of the carotenoid pigment okenone. Cultures of Marichromatium purpuratum 1591 (Mpurp1591) were observed to have carbon isotope fractionations ((13)ε biomass - CO2), via RuBisCO, ranging from -16.1 to -23.2‰ during exponential and stationary phases of growth. Cultures of Thiocapsa marina 5653 (Tmar5653) and Mpurp1591 had a nitrogen isotope fractionation ((15)ε biomass - NH 4) of -15‰, via glutamate dehydrogenase, measured and recorded for the first time in PSB. The δ(34) SVCDT values and amount of stored elemental sulfur for Mpurp1591 cells grown autotrophically and photoheterotrophically were dependent upon their carbon metabolic pathways. We show that PSB may contribute to the isotopic enrichments observed in modern and ancient anoxic basins. In a photoheterotrophic culture of Mpurp1591 that switched to autotrophy once the organic substrate was consumed, there were bulk biomass δ(13)C values that span a broader range than recorded across the Late Devonian, Permian-Triassic, Triassic-Jurassic, and OAE2 mass extinction boundaries. This finding stresses the complexities in interpreting and assigning δ(13)C values to bulk organic matter preserved in the geologic record.

Monitoring meticillin resistant Staphylococcus aureus and its spread in Copenhagen, Denmark, 2013, through routine whole genome sequencing

Typing of meticillin resistant Staphylococcus aureus (MRSA) by whole genome sequencing (WGS) is performed routinely in Copenhagen since January 2013. We describe the relatedness, based on WGS data and epidemiological data, of 341 MRSA isolates. These comprised all MRSA (n = 300) identified in Copenhagen in the first five months of 2013. Moreover, because MRSA of staphylococcal protein A (spa)-type 304 (t304), sequence type (ST) 6 had been associated with a continuous neonatal ward outbreak in Copenhagen starting in 2011, 41 t304 isolates collected in the city between 2010 and 2012 were also included. Isolates from 2013 found to be of t304, ST6 (n=14) were compared to the 41 earlier isolates. In the study, isolates of clonal complex (CC) 22 were examined in detail, as this CC has been shown to include the hospital-acquired epidemic MRSA (EMRSA-15) clone. Finally, all MRSA ST80 were also further analysed, as representatives of an important community-acquired MRSA in Europe. Overall the analysis identified 85 spa-types and 35 STs from 17 CCs. WGS confirmed the relatedness of epidemiologically linked t304 neonatal outbreak isolates. Several non-outbreak related patients had isolates closely related to the neonatal isolates suggesting unrecognised community chains of transmission and insufficient epidemiological data. Only four CC22 isolates were related to EMRSA-15. No community spread was observed among the 13 ST80 isolates. WGS successfully replaced conventional typing and added information to epidemiological surveillance. Creation of a MRSA database allows clustering of isolates based on single nucleotide polymorphism (SNP) calling and has improved our understanding of MRSA transmission.

Mapping QTL for the traits associated with heat tolerance in wheat (Triticum aestivum L.)

BACKGROUND

High temperature (heat) stress during grain filling is a major problem in most of the wheat growing areas. Developing heat tolerant cultivars has become a principal breeding goal in the Southern and Central Great Plain areas of the USA. Traits associated with high temperature tolerance can be used to develop heat tolerant cultivars in wheat. The present study was conducted to identify chromosomal regions associated with thylakoid membrane damage (TMD), plasmamembrane damage (PMD), and SPAD chlorophyll content (SCC), which are indicative of high temperature tolerance.

RESULTS

In this study we have reported one of the first linkage maps in wheat using genotype by sequencing SNP (GBS-SNP) markers to extreme response to post anthesis heat stress conditions. The linkage map was comprised of 972 molecular markers (538 Bin, 258 AFLPs, 175 SSRs, and an EST). The genotypes of the RIL population showed strong variation for TMD, SCC and PMD in both generations (F10 and F9). Composite interval mapping identified five QTL regions significantly associated with response to heat stress. Associations were identified for PMD on chromosomes 7A, 2B and 1D, SCC on 6A, 7A, 1B and 1D and TMD on 6A, 7A and 1D. The variability (R(2)) explained by these QTL ranged from 11.9 to 30.6% for TMD, 11.4 to 30.8% for SCC, and 10.5 to 33.5% for PMD. Molecular markers Xbarc113 and AFLP AGCTCG-347 on chromosome 6A, Xbarc121 and Xbarc49 on 7A, gwm18 and Bin1130 on 1B, Bin178 and Bin81 on 2B and Bin747 and Bin1546 on 1D were associated with these QTL.

CONCLUSION

The identified QTL can be used for marker assisted selection in breeding wheat for improved heat tolerance in Ventnor or Karl 92 genetic background.

Mapping QTL for the traits associated with heat tolerance in wheat (Triticum aestivum L.)

BACKGROUND

High temperature (heat) stress during grain filling is a major problem in most of the wheat growing areas. Developing heat tolerant cultivars has become a principal breeding goal in the Southern and Central Great Plain areas of the USA. Traits associated with high temperature tolerance can be used to develop heat tolerant cultivars in wheat. The present study was conducted to identify chromosomal regions associated with thylakoid membrane damage (TMD), plasmamembrane damage (PMD), and SPAD chlorophyll content (SCC), which are indicative of high temperature tolerance.

RESULTS

In this study we have reported one of the first linkage maps in wheat using genotype by sequencing SNP (GBS-SNP) markers to extreme response to post anthesis heat stress conditions. The linkage map was comprised of 972 molecular markers (538 Bin, 258 AFLPs, 175 SSRs, and an EST). The genotypes of the RIL population showed strong variation for TMD, SCC and PMD in both generations (F10 and F9). Composite interval mapping identified five QTL regions significantly associated with response to heat stress. Associations were identified for PMD on chromosomes 7A, 2B and 1D, SCC on 6A, 7A, 1B and 1D and TMD on 6A, 7A and 1D. The variability (R(2)) explained by these QTL ranged from 11.9 to 30.6% for TMD, 11.4 to 30.8% for SCC, and 10.5 to 33.5% for PMD. Molecular markers Xbarc113 and AFLP AGCTCG-347 on chromosome 6A, Xbarc121 and Xbarc49 on 7A, gwm18 and Bin1130 on 1B, Bin178 and Bin81 on 2B and Bin747 and Bin1546 on 1D were associated with these QTL.

CONCLUSION

The identified QTL can be used for marker assisted selection in breeding wheat for improved heat tolerance in Ventnor or Karl 92 genetic background.

Mapping QTL for the traits associated with heat tolerance in wheat (Triticum aestivum L.)

BACKGROUND

High temperature (heat) stress during grain filling is a major problem in most of the wheat growing areas. Developing heat tolerant cultivars has become a principal breeding goal in the Southern and Central Great Plain areas of the USA. Traits associated with high temperature tolerance can be used to develop heat tolerant cultivars in wheat. The present study was conducted to identify chromosomal regions associated with thylakoid membrane damage (TMD), plasmamembrane damage (PMD), and SPAD chlorophyll content (SCC), which are indicative of high temperature tolerance.

RESULTS

In this study we have reported one of the first linkage maps in wheat using genotype by sequencing SNP (GBS-SNP) markers to extreme response to post anthesis heat stress conditions. The linkage map was comprised of 972 molecular markers (538 Bin, 258 AFLPs, 175 SSRs, and an EST). The genotypes of the RIL population showed strong variation for TMD, SCC and PMD in both generations (F10 and F9). Composite interval mapping identified five QTL regions significantly associated with response to heat stress. Associations were identified for PMD on chromosomes 7A, 2B and 1D, SCC on 6A, 7A, 1B and 1D and TMD on 6A, 7A and 1D. The variability (R(2)) explained by these QTL ranged from 11.9 to 30.6% for TMD, 11.4 to 30.8% for SCC, and 10.5 to 33.5% for PMD. Molecular markers Xbarc113 and AFLP AGCTCG-347 on chromosome 6A, Xbarc121 and Xbarc49 on 7A, gwm18 and Bin1130 on 1B, Bin178 and Bin81 on 2B and Bin747 and Bin1546 on 1D were associated with these QTL.

CONCLUSION

The identified QTL can be used for marker assisted selection in breeding wheat for improved heat tolerance in Ventnor or Karl 92 genetic background.

Healthcare-associated outbreak of meticillin-resistant Staphylococcus aureus bacteraemia: role of a cryptic variant of an epidemic clone

Background

New strains of meticillin-resistant Staphylococcus aureus (MRSA) may be associated with changes in rates of disease or clinical presentation. Conventional typing techniques may not detect new clonal variants that underlie changes in epidemiology or clinical phenotype.

Aim

To investigate the role of clonal variants of MRSA in an outbreak of MRSA bacteraemia at a hospital in England.

Methods

Bacteraemia isolates of the major UK lineages (EMRSA-15 and -16) from before and after the outbreak were analysed by whole-genome sequencing in the context of epidemiological and clinical data. For comparison, EMRSA-15 and -16 isolates from another hospital in England were sequenced. A clonal variant of EMRSA-16 was identified at the outbreak hospital and a molecular signature test designed to distinguish variant isolates among further EMRSA-16 strains.

Findings

By whole-genome sequencing, EMRSA-16 isolates during the outbreak showed strikingly low genetic diversity (P < 1 × 10⁻⁶, Monte Carlo test), compared with EMRSA-15 and EMRSA-16 isolates from before the outbreak or the comparator hospital, demonstrating the emergence of a clonal variant. The variant was indistinguishable from the ancestral strain by conventional typing. This clonal variant accounted for 64/72 (89%) of EMRSA-16 bacteraemia isolates at the outbreak hospital from 2006.

Conclusions

Evolutionary changes in epidemic MRSA strains not detected by conventional typing may be associated with changes in disease epidemiology. Rapid and affordable technologies for whole-genome sequencing are becoming available with the potential to identify and track the emergence of variants of highly clonal organisms.

The provenances of asteroids, and their contributions to the volatile inventories of the terrestrial planets

Determining the source(s) of hydrogen, carbon, and nitrogen accreted by Earth is important for understanding the origins of water and life and for constraining dynamical processes that operated during planet formation. Chondritic meteorites are asteroidal fragments that retain records of the first few million years of solar system history. The deuterium/hydrogen (D/H) values of water in carbonaceous chondrites are distinct from those in comets and Saturn's moon Enceladus, implying that they formed in a different region of the solar system, contrary to predictions of recent dynamical models. The D/H values of water in carbonaceous chondrites also argue against an influx of water ice from the outer solar system, which has been invoked to explain the nonsolar oxygen isotopic composition of the inner solar system. The bulk hydrogen and nitrogen isotopic compositions of CI chondrites suggest that they were the principal source of Earth's volatiles.

Enteric disease surveillance under the AFHSC-GEIS: current efforts, landscape analysis and vision forward

The mission of the Armed Forces Health Surveillance Center, Division of Global Emerging Infections Surveillance and Response System (AFHSC-GEIS) is to support global public health and to counter infectious disease threats to the United States Armed Forces, including newly identified agents or those increasing in incidence. Enteric diseases are a growing threat to U.S. forces, which must be ready to deploy to austere environments where the risk of exposure to enteropathogens may be significant and where routine prevention efforts may be impractical. In this report, the authors review the recent activities of AFHSC-GEIS partner laboratories in regards to enteric disease surveillance, prevention and response. Each partner identified recent accomplishments, including support for regional networks. AFHSC/GEIS partners also completed a Strengths, Weaknesses, Opportunities and Threats (SWOT) survey as part of a landscape analysis of global enteric surveillance efforts. The current strengths of this network include excellent laboratory infrastructure, equipment and personnel that provide the opportunity for high-quality epidemiological studies and test platforms for point-of-care diagnostics. Weaknesses include inconsistent guidance and a splintered reporting system that hampers the comparison of data across regions or longitudinally. The newly chartered Enterics Surveillance Steering Committee (ESSC) is intended to provide clear mission guidance, a structured project review process, and central data management and analysis in support of rationally directed enteric disease surveillance efforts.

Clinical microbiology during the Vietnam War

During the period of 1965-1968, over two dozen Army microbiologists were deployed to various locations in Southeast Asia in support of the Vietnam War. Their role was to serve both a clinical laboratory mission/function at the mobile Army surgical hospital and mobile laboratory level as well as to perform research roles in all of the facilities. They were essential to the formulation of medical intelligence as well as to the practice of operational medicine in the deployed environment. The results of their laboratory investigations provided commanders and military physicians with critical medical information for patient care, outbreak investigation, and forensic analysis. As with many soldiers in support of the infantry and armor combat forces, most of the work occurs behind the scenes and their contributions are often left out of the historical literature. This article presents a brief overview of microbiology performed by Army microbiologists during the Vietnam War.

Immunohistochemical study of nuclear factor-kappaB activity and interleukin-8 abundance in oesophageal adenocarcinoma; a useful strategy for monitoring these biomarkers

AIMS

To determine if immunohistochemistry (IHC) could be used to monitor nuclear factor-kappaB (NF-kappaB) activity in oesophageal adenocarcinoma and pre-malignant (Barrett's) oesophageal tissues, relative to normal oesophageal mucosa. The pro-inflammatory cytokine interleukin-8 (IL-8), a transcriptional target of NF-kappaB, was also studied to better understand NF-kappaB functionality; its RNA and protein levels were assessed in oesophageal tissues.

METHODS

IHC was employed using an antibody against the nuclear localisation sequence (NLS) of the p65 subunit as well as an antibody against IL-8. To assess NF-kappaB function, changes in gene expression of NF-kappaB controlled genes (IL-8 and I-kappaB) were also assessed in the histological sequence using real-time PCR. More global expression changes were also studied using membrane arrays.

RESULTS

IHC was effective at monitoring overall NF-kappaB activity and IL-8 abundance. This method also allowed NF-kappaB activity and IL-8 abundance to be pinpointed in specific cell types. There were significant increases in nuclear NF-kappaB activity and IL-8 abundance across the histological series. Gene expression analysis also showed consistent up-regulation of IL-8, confirming the IHC data and showing enhanced transcriptional NF-kappaB activity. I-kappaB (another NF-kappaB target) showed down-regulation in dysplastic and adenocarcinoma tissues. Down-regulation of I-kappaB gene expression may partly explain increased NF-kappaB activity.

CONCLUSION

IHC, using antibodies against the NLS of p65, may be useful in monitoring overall NF-kappaB activity in oesophageal tissues. As IHC is amenable to high-throughput screening (whereas traditional electrophoretic mobility shift assay methods are not), this may lead to the development of a better screening tool for early cancer risk.

Effects of Ribose Supplementation Prior to and during Intense Exercise on Anaerobic Capacity and Metabolic Markers

This study examined whether ribose supplementation before and during intense anaerobic exercise impacts anaerobic capacity and metabolic markers. Twelve moderately trained male cyclists (22.3 ± 2.2 y; 181 ± 6 cm, 74.8 ± 9 kg) participated in the study. Subjects were familiarized and fasted for 8 h after standardizing nutritional intake. In a double blind and crossover manner subjects ingested either a 150 mL placebo or ribose (3 g ribose + 150 μg folate). Subjects rested for 25 min and completed 5 × 30 s anaerobic capacity tests with 3 min passive rest. Six capillary blood samples were taken prior to and after sprints for adenine nucleotide breakdown determination. The experiment was repeated 1 wk later with alternative drink. Data were analyzed by repeated measures ANOVA. No significant interactions were observed for any performance or blood variables. D-ribose supplementation has no impact on anaerobic exercise capacity and metabolic markers after high-intensity cycling exercise.

Predictors of participation in genetic research in a primary care physician network

This study evaluated the process of recruiting women from a primary care physician network into a study of genetic counseling for breast cancer. It also investigated predictors of women's interest in participating in genetic counseling research. Women were recruited in three stages: (a) via an initial contact letter; (b) a telephone screening survey; and (c) a mailed baseline questionnaire. We performed a logistic regression with participation as the outcome. We sent 4690 initial contact letters and conducted 2081 telephone surveys to recruit 340 participants. Number of relatives with cancer, higher interest in taking a genetic test for breast cancer, and lower degree of worry about cancer were strong predictors for women's participation. Recruitment data showed interest in a study on genetic counseling for breast cancer risk. However, interest decreased as study requirements increased. Participation in genetics-related studies is related to psychological differences that must be considered when generalizing findings.

Alteration of cytokine levels in murine retrovirus infection: modulation by combination therapy

Immunoregulatory cytokines may regulate the resistance or susceptibility of a host to retroviral infection. These cytokines may be therapeutically modulated to prevent or limit the progression of infection. The non-progression to AIDS of some HIV+ patients has been related to a strong type 1 cytokine response (IL-2, IL-12, and IFNgamma). For this reason, we investigated the ability of combination therapeutics to modulate cytokines in vivo towards a type 1 cytokine response in a murine retroviral infection using Friend leukemia virus (FLV). BALB/c mice were infected with FLV and treated with either 3'-azido-3'-deoxythymidine (AZT), the immunomodulator methionine enkephalin (MENK), or a combination of both AZT and MENK starting 3 d post infection. Splenocytes were harvested on days 1, 3, 7, 14, 21 and 28 post treatment initiation and cultured with 1 microg/ml concanavalin A (ConA) for 24 h. Supernatants were examined for IL-2, IL-4, IL-10, IL-12, and IFNgamma cytokine production using cytokine specific ELISAs. The levels of type 2 cytokines were not significantly changed by any treatment group over the course of the disease. However, although decreased in all infected animals, type 1 cytokines were partially maintained by the combination treatment through day 21. RT-PCR for cytokine specific mRNA confirmed these results, with expression of the type 1 cytokines, especially IFNgamma, being maintained through day 21. Establishment of a treatment regime that can maintain protective cytokine activities against disease progression may prove applicable to other retroviral infections.

Clinical significance of nephrotoxicity in patients treated with amphotericin B for suspected or proven aspergillosis

The records of 239 immunosuppressed patients receiving amphotericin B for suspected or proven aspergillosis were reviewed to determine rates of nephrotoxicity, dialysis, and fatality. The mean and median durations of treatment were 20.4 and 15.0 days, respectively. The creatinine level doubled in 53% of patients and exceeded 2.5 mg/dL in 29%; 14.5% underwent dialysis; and 60% died. A multivariate Cox proportional hazards analysis showed that patients whose creatinine level exceeded 2.5 mg/dL (hazard ratio [HR], 42.02; P<.001), allogeneic bone marrow transplantation (BMT) patients (HR, 6.34; P<. 001), and autologous BMT patients (HR, 5.06; P=.024) were at greatest risk for requiring hemodialysis. Use of hemodialysis (HR, 3. 089; P<.001), duration of amphotericin B use (HR, 1.03 per day; P=. 015), and use of nephrotoxic agents (HR, 1.96; P=.017) were associated with greater risk of death, whereas patients undergoing solid organ transplantation were at lowest risk (HR, 0.46; P=.002). These data indicate that elevated creatinine levels during amphotericin B treatment are associated with a substantial risk for hemodialysis and a higher mortality rate, but the risks vary in different patient groups.

Gene transfer in the gastrointestinal tract

The maximum in vivo transfer rate of plasmid pAMbeta1 in the gut was 0.03 transconjugant per recipient cell, and this rate could be simulated in vitro only by forced filter mating. Transfer was not detected in liquid culture matings. Our findings demonstrate that in vitro methods, such as forced filter mating and liquid mating, underestimate the in vivo rates of gene transfer.

Treatment of invasive fungal infections with amphotericin B colloidal dispersion in bone marrow transplant recipients

Amphotericin B colloidal dispersion (ABCD, AMPHOTEC, AMPHOCIL), a lipid complex of amphotericin B, was developed to reduce the nephrotoxicity of amphotericin B while retaining its antifungal efficacy. In this retrospective review, the efficacy and safety of ABCD were evaluated in 220 BMT recipients (167 allogeneic; 53 autologous) with suspected or documented life-threatening fungal infections (primarily Candida or Aspergillus species). Patients were treated in five open-label clinical trials of ABCD therapy. ABCD was administered intravenously once daily, median dose of 4 mg/kg, for up to 409 days (mean 23 days, median 16 days). Successful therapeutic response to treatment (complete or partial) was reported in 52% of the 99 evaluable patients with proven infection, and in 40% of all 220 patients. In the evaluable population, the response and mortality rates were 51% and 73%, respectively, in the allogeneic BMT patients, compared to 52% and 48% in the autologous BMT patients. The response rate for evaluable patients with Candida spp was 65%, 38% for patients with Aspergillus spp, and 42 % for patients with other or multiple fungal infections. In this patient population at high risk of nephrotoxicity due to concomitant cyclosporine and/or other nephrotoxic agents, ABCD did not cause renal dysfunction. Although the majority of patients had pre-existing renal impairment (median baseline serum creatinine 1.8 mg/dl), there was no trend towards increasing serum creatinine. No unexpected toxicities were observed. In conclusion, ABCD appears to be safe and effective for the treatment of severe fungal infections in BMT patients.

Human herpesvirus 6 infections after bone marrow transplantation: clinical and virologic manifestations

Human herpesvirus 6 (HHV-6) DNA levels in peripheral blood mononuclear cells were prospectively evaluated in 20 cytomegalovirus-seronegative allogeneic marrow transplant patients and in 10 healthy control subjects. Blood and saliva specimens obtained weekly for 3 months after transplant were evaluated by quantitative HHV-6 polymerase chain reaction. One of 20 patients experienced primary HHV-6 infection after marrow transplant (seroconversion, HHV-6 viremia, skin rash); 18 of 20 had increased peripheral blood mononuclear cell HHV-6 DNA levels consistent with asymptomatic reactivations, and 1 patient experienced a reactivation-associated skin rash. Genotyping revealed HHV-6 variant B DNA in all cases. Therapy with acyclovir or intravenous immunoglobulin was not correlated with lower HHV-6 DNA levels. Thus, asymptomatic HHV-6 reactivations appear to be common following allogeneic marrow transplantation. Among HHV-6-seronegative and viral DNA-negative patients, primary HHV-6 infection can ensue in association with self-limited clinical symptoms, including diffuse maculopapular rash.

Analysis of murine gammaherpesvirus-68 transcription during lytic and latent infection

Murine gammaherpesvirus-68 (MHV-68) is a gamma2-herpesvirus that upon experimental infection of laboratory mice establishes a latent infection in B lymphocytes. To date, no virus-encoded gene products have been reported to be expressed during latent infection. In this study, viral transcription has been analysed in a persistently infected B-cell line and abundant and preferential transcription of open reading frame M3 has been identified. Significantly, in situ hybridization analysis of latently infected mouse spleens with probes corresponding to 20 MHV-68 ORFs demonstrated active transcription of a single ORF, corresponding to M3. The kinetics and pattern of transcription of M3 were compared with that of the virally encoded tRNAs (vtRNAs), previously demonstrated to constitute a marker for latent infection in the spleen. Transcription of vtRNAs in splenic tissue could be first detected at 7 days post-inoculation (p.i.) in scattered cells in periarteriolar lymphoid sheaths (PALS). At 10 days p.i., vtRNA transcription was widespread and localized not only to cells in PALS but also to cells within developing germinal centres and from 21 days p.i. expression was detected exclusively within lymphoid follicles. Transcription of vtRNAs could be detected as late as 70 days p.i. In contrast, the histological localization of M3 transcription, which was first detected at 7 days p.i. in scattered cells in PALS, never changed and transcription could not be detected beyond 21 days p.i. These results suggest that M3 is an ORF that is expressed early during the establishment of latency in vivo.

The impact of candidemia on length of hospital stay, outcome, and overall cost of illness

Although numerous studies have examined trends in nosocomial fungal infections, few have specifically addressed the cost of care associated with candidemia. This study analyzes the direct medical costs associated with treating candidemia in the United States. The study design was a cost-of-illness analysis estimating the average cost of candidemia for a single episode of care. Data were obtained from three sources: the 1993 Healthcare Cost and Utilization Project of the Agency for Health Care Policy and Research, the relevant literature, and a clinical expert in systemic fungal infections. The estimated cost (1997 U.S.$) of an episode of care for candidemia is $34,123 per Medicare patient and $44,536 per private insurance patient. The major cost associated with candidemia is that of an increased hospital stay. The estimated cost of care for candidemia may change in the future because of the use of more expensive antifungal treatments with improved safety and efficacy profiles.

Lymphokine-augmented activation of avian heterophils

Heterophils are important mediators of innate resistance in poultry, especially in young birds that have not yet developed an acquired immune response. Invasion of the intestinal mucosa by Salmonella spp. initiates the recruitment of large numbers of heterophils to the lamina propria. Thus, the heterophilic response can control, but not eliminate, bacterial numbers in the bird until development of acquired immunity. Unfortunately, chicks and turkey poults are highly susceptible to Salmonella infections during the first 4 d posthatch due to the functional immaturity of both the innate and acquired immune systems. We have previously shown that the administration of Salmonella enteritidis (SE)-immune lymphokines (ILK) into either 18-d-old developing embryos or day-of-hatch chicks and poults conferred increased resistance to SE organ invasion. In this review, we present evidence that the protection induced by ILK is mediated by vigorous recruitment and activation of heterophils. These activated heterophils migrate rapidly to the site of bacterial invasion where they phagocytize and kill the SE. Specifically, in vitro studies demonstrate an enhancement of functional activities of the heterophils including chemotaxis, adherence, phagocytosis, and bacterial killing. In addition, during the activation process, membrane expression of adhesion molecules rapidly changes from L-selectins to beta2 integrins (CB11b/CD18) on the cells that become activated. These results further demonstrate the validity of preventive activation in poultry to induce the migration of large numbers of activated phagocytic cells to the site of infection by a pathogenic organism. Importantly, this immunopotentiation of the inflammatory response by ILK, as described here, induces the functional maturation of heterophils during the first 4 d posthatch.

Marrow transplantation for chronic myeloid leukemia: the influence of plasma busulfan levels on the outcome of transplantation

The influence of busulfan (BU) plasma concentration on outcome of transplantation from HLA identical family members for the treatment of chronic myelogenous leukemia (CML) was examined in 45 patients transplanted in chronic phase (CP) (n = 39) or accelerated phase (AP) (n = 6). All patients received the same regimen of BU, 16 mg/kg orally and cyclophosphamide (CY), 120 mg/kg intravenously. Plasma concentrations of BU at steady state (C(SS)BU) during the dosing interval were measured for each patient. The mean C(SS)BU was 917 ng/mL (range, 642 to 1,749; median, 917; standard deviation, 213). Of patients with C(SS)BU below the median, seven (five of 18 in CP and two of four in AP) developed persistent cytogenetic relapse and three of these patients died. There were no relapses in patients with C(SS)BU above the median. The difference in the cumulative incidence of relapse between the two groups was statistically significant (P = .0003). C(SS)BU was the only statistically significant determinant of relapse in univariable or multivariable analysis. The 3-year survival estimates were 0.82 and 0.64 for patients with C(SS)BU above and below the median (P = .33). There was no statistically significant association of C(SS)BU with survival or nonrelapse mortality, although the power to detect a difference in survival between 0.82 and 0.64 was only 0.24, similarly C(SS)BU above the median was not associated with an increased risk of severe regimen-related toxicity. We conclude that low BU plasma levels are associated with an increased risk of relapse.

Retention of herpes simplex virus DNA sequences in the nuclei of mouse footpad keratinocytes after recovery from primary infection

Persistence of herpes simplex virus (HSV) DNA in mouse footpad keratinocytes was studied by non-isotopic in situ hybridization. HSV DNA was retained in keratinocyte nuclei for more than 2 weeks after disappearance of infectious virus and viral antigens. The anatomical location of viral DNA became more superficial with increasing time post-infection, reflecting the migration of cells from the basal layer of the epidermis towards the stratum granulosum. Latency-associated transcripts (LATs) were not detected in footpad cells at any of the times studied. In contrast, LATs were detected readily in the nuclei of lumbar ganglionic neurons innervating HSV DNA positive footpads. It was concluded that, after termination of productive infection in the skin, HSV DNA persists transiently in keratinocyte nuclei, in the absence of abundant latency-associated transcription. An implication of these data is that detection of HSV DNA in the skin may reflect recent, but not necessarily current, cutaneous virus replication.

Multicenter evaluation of proposed standardized procedure for antifungal susceptibility testing of filamentous fungi

A multicenter study was conducted to expand the generation and analysis of data that supports the proposal of a reference method for the antifungal susceptibility testing of filamentous fungi. Broth microdilution MICs of amphotericin B and itraconazole were determined in 11 centers against 30 coded duplicate pairs of Aspergillus spp., Fusarium spp., Pseudallescheria boydii, and Rhizopus arrhizus. The effect of inoculum density (approximately 10(3) and 10(4) CFU/ml), incubation time (24, 48, and 72 h), and procedure of MIC determination (conventional and colorimetric [Alamar Blue] evaluation of growth inhibition) on intra- and interlaboratory agreement was analyzed. Based on intra- (97 to 100%) and interlaboratory (94 to 95%) agreement for both drugs, the overall optimal testing conditions identified were determination of colorimetric MICs after 48 to 72 h of incubation with an inoculum density of approximately 10(4) CFU/ml. These testing conditions are proposed as guidelines for a reference broth microdilution method.

Legionellosis in a bone marrow transplant center

We reviewed 10 cases of culture proven legionellosis that occurred at a marrow transplant center (Fred Hutchinson Cancer Research Center, Seattle, WA, USA) over a 6-year period ending in 1993. Infections were caused by four species of Legionella with no apparent clustering of cases. Detection of Legionella using direct fluorescent antibody assays proved unreliable due to the high proportion of rare Legionella species isolated. The clinical presentation, course and outcome of patients varied and did not correlate with underlying disease, type of transplant, transplant day or engraftment status. However, five of the seven patients infected with non-pneumophila species recovered from their pneumonia compared to none of the three patients infected with L. pneumophila. Persistent or relapsed infection after 3 weeks of appropriate therapy was documented in one case suggesting that prolonged antibiotic treatment is indicated in these patients.

Fungal liver infection in marrow transplant recipients: prevalence at autopsy, predisposing factors, and clinical features

To determine the prevalence of fungal liver infection at autopsy in marrow transplant recipients, we reviewed autopsy results for the period 1980-1989. Cases were compared to randomly chosen autopsied controls without fungal infection. Fungal liver infection was found in 67 (9%) of 731 patients. Fungal cultures of liver lesions were positive for 34 of 67 patients, most of whom had been culture-positive for the same fungal species (largely Candida) during life. Multivariate analysis revealed that independent predictors of fungal liver infection were deep fungal infection after transplantation (RR, 35), colonization or superficial infection after transplantation (RR, 13), and severe liver dysfunction caused by veno-occlusive disease of the liver and/or graft-versus-host disease (RR, 7). Clinical and laboratory findings during the last month of life revealed no differences between cases and controls. Liver imaging studies performed during the last 15 days of life had a sensitivity of only 18% for detecting fungal liver lesions.