Pan-azole- and multi-fungicide-resistant Aspergillus fumigatus is widespread in the United States

Aspergillus fumigatus is an important global fungal pathogen of humans. Azole drugs are among the most effective treatments for A. fumigatus infection. Azoles are also widely used in agriculture as fungicides against fungal pathogens of crops. Azole-resistant A. fumigatus has been increasing in Europe and Asia for two decades where clinical resistance is thought to be driven by agricultural use of azole fungicides. The most prevalent mechanisms of azole resistance in A. fumigatus are tandem repeats (TR) in the cyp51A promoter coupled with mutations in the coding region which result in resistance to multiple azole drugs (pan-azole resistance). Azole-resistant A. fumigatus has been isolated from patients in the United States (U.S.), but little is known about its environmental distribution. To better understand the distribution of azole-resistant A. fumigatus in the U.S., we collected isolates from agricultural sites in eight states and tested 202 isolates for sensitivity to azoles. We found azole-resistant A. fumigatus in agricultural environments in seven states showing that it is widespread in the U.S. We sequenced environmental isolates representing the range of U.S. sample sites and compared them with publicly available environmental worldwide isolates in phylogenetic, principal component, and ADMIXTURE analyses. We found worldwide isolates fell into three clades, and TR-based pan-azole resistance was largely in a single clade that was strongly associated with resistance to multiple agricultural fungicides. We also found high levels of gene flow indicating recombination between clades highlighting the potential for azole-resistance to continue spreading in the U.S.IMPORTANCEAspergillus fumigatus is a fungal pathogen of humans that causes over 250,000 invasive infections each year. It is found in soils, plant debris, and compost. Azoles are the first line of defense antifungal drugs against A. fumigatus. Azoles are also used as agricultural fungicides to combat other fungi that attack plants. Azole-resistant A. fumigatus has been a problem in Europe and Asia for 20 years and has recently been reported in patients in the United States (U.S.). Until this study, we did not know much about azole-resistant A. fumigatus in agricultural settings in the U.S. In this study, we isolated azole-resistant A. fumigatus from multiple states and compared it to isolates from around the world. We show that A. fumigatus which is resistant to azoles and to other strictly agricultural fungicides is widespread in the U.S.

The Evolutionary Origins and Ancestral Features of Septins

Septins are a family of membrane-associated cytoskeletal GTPases that play crucial roles in various cellular processes, such as cell division, phagocytosis, and organelle fission. Despite their importance, the evolutionary origins and ancestral function of septins remain unclear. In opisthokonts, septins form five distinct groups of orthologs, with subunits from multiple groups assembling into heteropolymers, thus supporting their diverse molecular functions. Recent studies have revealed that septins are also conserved in algae and protists, indicating an ancient origin from the last eukaryotic common ancestor. However, the phylogenetic relationships among septins across eukaryotes remained unclear. Here, we expanded the list of non-opisthokont septins, including previously unrecognized septins from rhodophyte red algae and glaucophyte algae. Constructing a rooted phylogenetic tree of 254 total septins, we observed a bifurcation between the major non-opisthokont and opisthokont septin clades. Within the non-opisthokont septins, we identified three major subclades: Group 6 representing chlorophyte green algae (6A mostly for species with single septins, 6B for species with multiple septins), Group 7 representing algae in chlorophytes, heterokonts, haptophytes, chrysophytes, and rhodophytes, and Group 8 representing ciliates. Glaucophyte and some ciliate septins formed orphan lineages in-between all other septins and the outgroup. Combining ancestral-sequence reconstruction and AlphaFold predictions, we tracked the structural evolution of septins across eukaryotes. In the GTPase domain, we identified a conserved GAP-like arginine finger within the G-interface of at least one septin in most algal and ciliate species. This residue is required for homodimerization of the single Chlamydomonas septin, and its loss coincided with septin duplication events in various lineages. The loss of the arginine finger is often accompanied by the emergence of the α0 helix, a known NC-interface interaction motif, potentially signifying the diversification of septin-septin interaction mechanisms from homo-dimerization to hetero-oligomerization. Lastly, we found amphipathic helices in all septin groups, suggesting that curvature-sensing is an ancestral trait of septin proteins. Coiled-coil domains were also broadly distributed, while transmembrane domains were found in some septins in Group 6A and 7. In summary, this study advances our understanding of septin distribution and phylogenetic groupings, shedding light on their ancestral features, potential function, and early evolution.

Septins From Protists to People

Septin GTPases form nonpolar heteropolymers that play important roles in cytokinesis and other cellular processes. The ability to form heteropolymers appears to be critical to many septin functions and to have been a major driver of the high conservation of many septin domains. Septins fall into five orthologous groups. Members of Groups 1–4 interact with each other to form heterooligomers and are known as the “core septins.” Representative core septins are present in all fungi and animals so far examined and show positional orthology with monomer location in the heteropolymer conserved within groups. In contrast, members of Group 5 are not part of canonical heteropolymers and appear to interact only transiently, if at all, with core septins. Group 5 septins have a spotty distribution, having been identified in specific fungi, ciliates, chlorophyte algae, and brown algae. In this review we compare the septins from nine well-studied model organisms that span the tree of life (Homo sapiens, Drosophila melanogaster, Schistosoma mansoni, Caenorhabditis elegans, Saccharomyces cerevisiae, Aspergillus nidulans, Magnaporthe oryzae, Tetrahymena thermophila, and Chlamydomonas reinhardtii). We focus on classification, evolutionary relationships, conserved motifs, interfaces between monomers, and positional orthology within heteropolymers. Understanding the relationships of septins across kingdoms can give new insight into their functions.

Simultaneous radical nephrectomy and repair of abdominal aortic aneurysm

OBJECTIVES

The combination of abdominal aortic aneurysm repair with other intra-abdominal surgery is controversial. Most studies have shown that a variety of procedures can be performed at the same time as an aneurysm repair with little change in mortality or complication rates. We conducted a retrospective study to determine if aneurysm repair could be safely and effectively combined with radical nephrectomy.

METHODS

We studied 10 patients who underwent combined abdominal aortic aneurysm repair and radical nephrectomy during a 4-year period. Results from this group were compared to a separate control group of 10 patients who underwent radical nephrectomy alone and another of 12 patients underwent abdominal aortic aneurysm repair alone, during the same time period.

RESULTS

The overall mortality was 10% and significant complications occurred in an additional 10% of patients. Minor, self-limiting complications occurred in 30% of patients. There were no aortic graft infections that occurred in the entire series of patients at 18 months of mean follow-up. There were no remarkable differences in the entire series of patients and the combined values in a separate group of control patients who had undergone either procedure alone.

CONCLUSIONS

Simultaneous radical nephrectomy for presumed renal cell carcinoma can be safely combined with repair of abdominal aortic aneurysm in selected patients.

Percutaneous, transperineal cryosurgery of the prostate as salvage therapy for post radiation recurrence of adenocarcinoma

BACKGROUND

Surgical techniques utilizing the application of very low temperatures to malignant tissues have been used increasingly in recent years in the minimally invasive treatment of prostate cancer. An area of potential application appears to be in the management of radiation resistant prostate cancer.

METHODS

This study represents a retrospective chart review of 33 patients undergoing cryosurgical ablation of the prostate (CSAP) according to a protocol designed by an institutional review board at a single institution for the treatment of radiation resistant prostate cancer. Radiation resistance was defined as a positive prostate needle biopsy and rising prostate specific antigen (PSA). Treatment effect was assessed by serial post treatment PSA determinations and extensive systematic post treatment prostate needle biopsies.

RESULTS

Of the 33 patients analyzed, 24 converted to an all negative biopsy status after one CSAP treatment. Repeat treatment converted two additional patients to a biopsy negative status. CSAP appeared to lower PSA dramatically in most patients. One year after treatment, of 10 patients not on androgen deprivation therapy, 3 maintained a PSA of < 0.4 ng/mL and those patients with androgen deprivation therapy maintained a PSA of < 4.0 ng/mL. The most frequent complications included sloughing syndrome (15.4%) and incontinence (10.3%).

CONCLUSIONS

CSAP appears to eliminate biopsy detectable prostate tumor effectively in the majority of cases in the salvage setting following radiation therapy. A significant discrepancy exists, however, between the biopsy "cure" rate and the biochemical "cure" rate, even in the short term. There is a suggestion that early detection of radiation failure may improve results of this salvage therapy.

Cloning, nucleotide sequence, and expression of a p-hydroxybenzoate hydroxylase isozyme gene from Pseudomonas fluorescens

A gene encoding for a putative isozyme of p-hydroxy-benzoate hydroxylase (PHBH) has been isolated from Pseudomonas fluorescens (ATCC 13525). A comparison of the translated amino acid sequence with that of the known PHBH from P. fluorescens revealed that the new enzyme contains 3 additional amino acids and has 73% absolute homology to the previously known enzyme; conservation of secondary and active-site structures implied that the isozyme and known enzyme share the same general tertiary structure. Subsequent expression of the isozyme in Escherichia coli produced an enzyme with a specific activity about half that of the previously characterized PHBHs from P. fluorescens and Pseudomonas aeruginosa; in addition, somewhat weaker binding affinities for both NADPH and p-hydroxybenzoate were observed. Speculations are made on the reason for the existence of the isozyme, which does not appear to be expressed routinely in P. fluorescens.