Mixed group of Rhizobiales microbes in lung and blood of a patient with fatal pulmonary illness.

We examined the microbial composition in the diseased lung and early-phase microbial cultures from the blood of a patient with a rapidly progressing fatal pulmonary illness. Although no microbes could be isolated from such cultures during the initial study, the HTS-microbiome study revealed the presence of a unique mixture of alphaproteobacteria, composed mainly of different families of Rhizobiales microbes. Microbial 16S rDNA sequences matching closely to Afipia cberi were identified mainly in the patient's diseased lung tissue, but only rarely in the early-phase blood cultures. Conversely, the high abundance of sequences found in early-phase blood cultures of different broth media matched closely with those of the families Methylobacteriaceae, Phyllobacteriaceae and Sphingomonadaceae. The two species that successfully adapted to grow in a laboratory culture system were A. cberi and Mesorhizobium hominis, which eventually were isolated from a previously cryopreserved blood culture of SP4 broth. Many other species, including members of the Bradyrhizobiaceae and Phyllobacteriaceae families, and all members of the Methylobacteriaceae and Sphingomonadaceae families identified by HTS remained non-cultivated. We developed specific PCR primers and FISH probes, which detected the target Rhizobiales microbes in former blood cultures and autopsy lung tissues. It is unclear what role these Rhizobiales microbes might have played in the patient's complex disease process. However, the above mentioned assays should help in rapidly detecting and identifying these previously unrecognized Rhizobiales microbes in patients.

Isolation and characterization of two novel bacteria Afipia cberi and Mesorhizobium hominis from blood of a patient afflicted with fatal pulmonary illness.

We recently isolated and discovered new Bradyrhizobiaceae microbes from the cryopreserved culture broth of blood samples from 3 patients with poorly defined illnesses using modified SP4 media and culture conditions coupled with genomic sequencing. Using a similar protocol, we studied a previously cryopreserved culture broth of blood sample from a patient who had succumbed to an acute onset of fulminant pulmonary illness. We report that two phases of microbial growth were observed in the re-initiated culture. Biochemical and genomic characterization revealed microbes isolated from the first phase of growth were new Afipia species of Bradyrhizobiaceae, tentatively named A. cberi with a ~ 5 MB chromosome that was different from those of all previously known Afipia microbes including the newly discovered A. septicemium. The microbes isolated from the second phase of growth were prominent sugar assimilators, novel Phyllobacteriaceae, phylogenetically most closely related to Mesorhizobium and tentatively named M. hominis with a ~ 5.5 MB chromosome. All A. cberi isolates carry a circular ~ 140 KB plasmid. Some M. hominis isolates possess a circular ~ 412 KB plasmid that can be lost in prolonged culture or passage. No antibiotics resistant genes could be identified in both of the A. cberi and M. hominis plasmids. Antibiotic susceptibility studies using broth culture systems revealed isolates of A. cberi could be sensitive to some antibiotics, but all isolates of M. hominis were resistant to essentially all tested antibiotics. However, the cell-free antibiotics susceptibility test results may not be applicable to clinical treatment against the microbes that are known to be capable of intracellular growth. It remains to be determined if the 2 previously unknown Rhizobiales were indeed pathogenic and played a role in the pulmonary disease process in this patient. Specific probes and methods will be developed to re-examine the diseased lungs from patient's autopsy.

A prospective, randomized trial of single-drug versus dual-drug immunosuppression in heart transplantation: the tacrolimus in combination, tacrolimus alone compared (TICTAC) trial.

BACKGROUND: Cardiac transplantation, a procedure nearly abandoned in the 1970s, has evolved into the standard of care for appropriate patients with end-stage heart failure. Much of this success has been due to improvements in immunosuppression, including the introduction of a triple-drug regimen. Retrospective reports suggested that single-drug immunosuppression with tacrolimus was feasible. As such, a prospective, randomized trial was conducted to test this approach. METHODS AND RESULTS: One hundred fifty adult de novo heart transplant recipients were enrolled in a prospective, randomized, controlled, open-label trial comparing tacrolimus monotherapy (MONO) with tacrolimus and mycophenolate mofetil therapy (COMBO). Corticosteroids were used in the early postoperative period but discontinued in all patients over 8 to 9 weeks. The primary end point was the composite biopsy score at 6 months after transplant. Patients were followed for 1 to 5 years. The composite biopsy score was similar between groups at 6 and 12 months: 6-month MONO, 0.70 ± 0.44 (95% confidence interval, 0.60 to 0.80) versus COMBO, 0.65 ± 0.40 (95% confidence interval, 0.55 to 0.74; P=0.44). Allograft vasculopathy was assessed by angiography and intravascular ultrasound, with no significant differences noted. Three-year survival was also similar (92.4% MONO versus 97% COMBO; P=0.58, log-rank). CONCLUSIONS: Addition of mycophenolate to single-agent immunosuppression did not provide an advantage over single-agent immunosuppression in terms of rejection, allograft vasculopathy, or 3-year survival. Corticosteroids, which have traditionally been a mainstay of therapy, were successfully discontinued in all patients. These conclusions are tempered by the limited statistical power associated with a sample size of only 150 patients. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00299221.

Detection of early renal transplant rejection by minimally-invasive monitoring of impedance variability.

BACKGROUND: Allograft rejection that occurs after renal transplants is identified by surveillance biopsies or by abnormal laboratory and/or hemodynamic data. The latter are insensitive markers of rejection that may not appear until significant histologic damage has already occurred. Therefore, a sensitive and specific non-invasive method of detecting early rejection of transplanted solid organs is needed. METHOD: A single canine renal allograft was implanted followed by bilateral nephrectomy. Bipolar pacing electrodes were implanted at each end of the transplanted kidney. A second set of electrodes was implanted in the liver, which served as a non-rejecting normal organ. Electrodes were connected to an implantable sensor placed in the subcutaneous tissue. Electrical tissue impedance levels were telemetrically downloaded daily. The clinical status of the transplanted organ was monitored by following the blood urea nitrogen and serum creatinine levels, urine output, and clinical appearance. After tissue impedance levels had stabilized, all immunosuppressants were abruptly discontinued. Clinical signs of rejection were then observed after a few days. RESULTS: Rejection was accompanied by changes in electrical impedance of the implanted organ. These changes, when observed, occurred 1-5 days before clinical signs of rejection appeared. CONCLUSION: Analyses of these data suggest that development of a minimally-invasive high-confidence sensor of early rejection of solid organ transplants is feasible.

Intramuscular low-grade myxoid neoplasm with recurrent potential (cellular myxoma) of the lower extremity: case report with cytohistologic correlation and review of the literature.

"Low-grade myxoid neoplasm with recurrent potential" (cellular myxoma) is a term recently used to describe a subset of soft tissue lesions with histology intermediate between intramuscular myxoma and low-grade myxofibrosarcoma or myxoid malignant fibrous histiocytoma (MFH), while resembling a deeper counterpart of superficial angiomyxoma. Their distinctive biological behavior is characterized by the potential to recur locally, in contrast to intramuscular myxoma, while having no potential to advance in grade or metastasize when compared to low-grade myxofibrosarcoma. We present a cytohistological correlation for an intramuscular location of such a tumor in the lower extremity of a 49-yr-old male.