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Untargeted metabolomics reveals anion and organ-specific metabolic responses of salinity tolerance in willow.

Willows can alleviate soil salinisation while generating sustainable feedstock for biorefinery, yet the metabolomic adaptations underlying their tolerance remain poorly understood. Salix miyabeana was treated with two environmentally abundant salts, NaCl and Na2SO4, in a 12-week pot trial. Willows tolerated salts across all treatments (up to 9.1 dS m-1 soil ECe), maintaining biomass while selectively partitioning ions, confining Na+ to roots and accumulating Cl- andin the canopy and adapting to osmotic stress via reduced stomatal conductance. Untargeted metabolomics captured >5000 putative compounds, including 278 core willow metabolome compounds constitutively produced across organs. Across all treatments, salinity drove widespread metabolic reprogramming, altering 28% of the overall metabolome, with organ-tailored strategies. Comparing salt forms at equimolar sodium, shared differentially abundant metabolites were limited to 3% of the metabolome, representing the generalised salinity response, predominantly in roots. Anion-specific metabolomic responses were extensive. NaCl reduced carbohydrates and tricarboxylic acid cycle intermediates, suggesting potential carbon and energy resource pressure, and accumulated root structuring compounds, antioxidant flavonoids, and fatty acids. Na2SO4 salinity triggered accumulation of sulphur-containing larger peptides, suggesting excess sulphate incorporation leverages ion toxicity to produce specialised salt-tolerance-associated metabolites. This high-depth picture of the willow metabolome underscores the importance of capturing plant adaptations to salt stress at organ scale and considering ion-specific contributions to soil salinity.

Salix

Development of molecular markers associated with saline-alkali tolerance in rapeseed (Brassica napus L.).

A total of 947 saline-alkaline tolerance-related molecular markers and a 5K cGPS genotyping chipwere developed, providing practical tools for marker-assisted selection and molecular design breeding of saline-alkaline-tolerant rapeseed. Rapeseed (Brassica napus L.) has relatively strong tolerance to saline-alkaline stress and shows great potential for the sustainable utilization and improvement of saline-alkaline soils. However, the breeding of highly tolerant cultivars still mainly depends on conventional hybridization combined with phenotype-based selection, which constrains breeding efficiency. In this study, previously reported saline-alkaline tolerance-related genes from rapeseed, rice, maize, wheat, sorghum, and Arabidopsis were collected. Candidate gene-based association analysis enabled the development of molecular markers and a genotyping chip. A total of 483 significantly associated genes were identified, among which 355 genes contained favorable haplotypes. Molecular markers were successfully developed for 275 genes, including 746 KASP and 201 InDel marker pairs, and four marker pairs were randomly selected for validation. In addition, a 5K cGPS liquid-phase chip (HZSW-cGPS-BRNAP-04), was developed and showed a high call rate and excellent reproducibility in genotyping. These markers and the chip are expected to improve the breeding efficiency of saline-alkaline-tolerant rapeseed cultivars. Overall, this study provides useful tools for early-generation evaluation and marker-assisted selection (MAS), and provides a foundation for molecular design breeding of saline-alkali-tolerant rapeseed.

Brassica napus

Long-term saline-alkaline selection rewires the growth-survival trade-off in Priestia megaterium.

Saline-alkaline soils impose persistent osmotic, ionic, pH, and nutrient stress on soil microorganisms, but the evolutionary routes by which beneficial bacteria adapt to such conditions remain poorly resolved. We performed adaptive laboratory evolution to examine the adaption of the plant growth-promoting rhizobacterium Priestia megaterium HA22 to long-term oligotrophic saline-alkaline selection. After 175 serial transfers, the evolved lineage proliferated stably at 40 g L-1 Na2SO4 at pH 10.0, whereas the wild-type strain failed to proliferate. Genome resequencing and allelic replacement revealed a 5-bp insertion in spo0A, the master sporulation regulator, as a major adaptive mutation. This mutation abolished sporulation; shortened the lag phase; and enhanced vegetative growth, nutrient uptake, and expression of tricarboxylic acid cycle and nitrogen metabolism gene under saline-alkaline stress. According to untargeted metabolomics, adaptation was accompanied by increased amino acid metabolism and aminoacyl-tRNA biosynthesis, with proline, isoleucine and pantothenic acid functionally promoting growth. A point mutation in ugpB enhanced glycerol-3-phosphate uptake, increased peptidoglycan and wall teichoic acid levels, and partially rescued the survival cost of the spo0A mutation. In greenhouse assays under combined saline-alkaline stress, the evolved strain increased soybean shoot dry weight and root dry weight by 56.08% and 27.02%, respectively. These results indicate that prolonged, predictable saline-alkaline selection can favor active growth rather than dormancy when compensatory cell envelope reinforcement buffers survival costs.

Adaptive laboratory evolution

Effect of freezing and thawing on survival of three bacterial isolates from an arctic soil.

Three isolates, a Pseudomonas sp., Bacillus sp., and Arthrobacter sp., which had been isolated from a meadow soil at Devon Island, Canada, were subjected to freezing and thawing at low rates under various conditions. When cells were frozen in sand or soil, survival was dependent on moisture level, storage time, and thaw rate. Pseudomonas M216 was most susceptible to freeze-thaw damage under these conditions. Arthrobacter M51 was the most resistant of the three isolates when frozen in sand or soil and when frozen at a high rate after growth at varing rates at 5 and 15 degrees C in carbon-or nitrogen-limited media. Pseudomonas M216 was more sensitive to freeze-thaw damage when NaCl was present in the freezing menstruum, even at low freezing rates. Survival of cells frozen in growth medium, water, saline, and soil extract was not affected by the freezing rate when it was less than 1 degrees C min-1. Soil extract did not protect cells from freeze-thaw damage any more than water and for Arthrobacter M51 survival was decreased when it was frozen in soil extract.

Arctic Regions

Comparative metagenomic analysis of microbial communities: unravelling microbial communities from the great Rann of Kachchh and coastal saltpans, Gujarat, India.

Hypersaline environments exhibit extreme physiochemical conditions yet support diverse microbial communities. These communities are not only ecologically important but also possess substantial potential for biotechnological exploitation. In this study, we employed a comparative metagenomic approach to assess microbial diversity using two distinct methodologies: (1) direct DNA extraction from raw sediment, and (2) DNA extraction following halophilic enrichment in selective media. Sediment samples were collected from multiple sites and pooled together within the Rann of Kachchh and close-by saltpans and were analysed using 16S rRNA sequencing coupled with bioinformatics pipelines. The results revealed pronounced differences in microbial community composition between the two approaches. Raw sediment samples exhibited significantly higher alpha diversity, with dominant taxa including Halobacterota, Cyanobacteria, and Desulfobacterota, with a substantial proportion of unclassified genera. In contrast, enriched samples were dominated by fast-growing, culturable genera such as Halobacterium, Alkalibacillus, and Candidatus haloredivivus. Principal Coordinate Analysis (PCoA) of beta diversity demonstrated distinct clustering between raw and enriched communities, even within samples from the same sites, underscoring the selective bias introduced by enrichment procedures. These findings emphasise that the methodological choice strongly influences the observed microbial diversity. The aim of this study was to compare microbial community composition in raw hypersaline sediments and enrichment cultures using metagenomic sequencing, to evaluate how enrichment selectively favours specific halophilic taxa. This comparative approach allows identification of the microbial groups that rapidly proliferate under controlled hypersaline conditions, thereby complementing direct environmental sequencing. By integrating both direct and enrichment-based metagenomic approaches, a more comprehensive understanding of microbial community structure in hypersaline environments can be achieved.

India

Biocontrol efficacy of Bacillus albus SSR3 for controlling postharvest fungal pathogens and mycotoxin contamination.

Sweetpotato black rot, caused by Ceratocystis fimbriata, is a major postharvest disease that leads to substantial storage losses worldwide. In this study, a salt-tolerant rhizobacterial strain, Bacillus albus SSR3, was isolated from the rhizosphere of sweetpotato grown in saline-alkali soil, with broad-spectrum antagonistic activity against postharvest fungal pathogens. LC-MS/MS analysis revealed diverse bioactive metabolites associated with its antifungal activity. Integrated transcriptomic and metabolomic analyses showed that SSR3 bioactive metabolites extensively reprogrammed fungal metabolism, particularly pathways involved in carbohydrate and amino acid metabolism, antioxidant defense, and energy production. These alterations were accompanied by disruption of cell wall and membrane integrity, excessive reactive oxygen species accumulation, and mitochondrial dysfunction, ultimately inhibiting fungal growth. Here, we also found that SSR3 bioactive metabolites effectively inhibited aflatoxin B1 production by Aspergillus flavus and deoxynivalenol accumulation in Fusarium graminearum. In vivo assays further demonstrated that SSR3 bioactive metabolites significantly reduced sweetpotato black rot severity and effectively limited fungal colonization and mycotoxin contamination in stored agricultural commodities. Collectively, our findings demonstrate that B. albus SSR3 suppresses postharvest fungal pathogens through coordinated metabolic reprogramming, oxidative stress induction, and cellular integrity disruption, highlighting its potential as a sustainable biocontrol agent for postharvest disease management.

Bacillus albus

Circle-seq analysis reveals the involvement of eccDNAs in salt stress response of bermudagrass (Cynodon dactylon).

Extrachromosomal circular DNAs (eccDNAs) have been identified in a wide variety of plant species and play a pivotal role in genomic plasticity, emerging as key drivers of stress adaptation. However, the putative roles of eccDNAs under environmental stress remain largely unexplored in plants. As a high-quality turfgrass, bermudagrass (Cynodon dactylon L.) is a pivotal species for the reclamation and improvement of saline-alkali soils. Therefore, we performed a comprehensive analysis of the eccDNA profiles in bermudagrass under salt stress. A total of 1,068 eccDNAs were identified across all chromosomes. These eccDNAs were characterized by short lengths (ranging from 100 bp to 1 kb) and low GC content. Their genomic distribution was not entirely random but rather exhibited a certain preference for intergenic regions and coding sequences (CDS). Crucially, null model analysis of A/T-rich junction sites revealed that these eccDNAs primarily originate from physically unstable scaffold/matrix attachment regions (S/MARs) via stochastic fragmentation, followed by opportunistic circularization predominantly mediated by the non-homologous end joining (NHEJ) pathway. Notably, salt stress specifically enriched eccDNAs derived from DNA transposons, including the Tc1/Mariner, CACTA and MITE superfamilies. Overall, our findings reveal complex extrachromosomal structural dynamics in bermudagrass, offering novel insights into its genomic adaptation under environmental stress.

Cynodon

Rate of elemental sulfur oxidation in some soils of Egypt as affected by the salinity level, moisture, texture, temperature and inoculation.

1. The level of soil moisture most favourable to the oxidation of elemental sulfur was found to be around the field moisture capacity; the oxidation rate decreased at lower and higher moisture levels. 2. The rate of oxidation increased with the clay content of the soils from sandy loam to clay loam. 3. Although S-oxidation could be found already at 10 degrees C, it increased markedly up to a maximum at 35 degrees C and then decreased again at higher temperatures. 4. Increasing the salt content of the soil (NaCl) reduced the rate of oxidation up to a concentration of 9 g salt/100 g soil; at a concentration of salt of 11 g/100 g soil no S-oxidation occurred. 5. Inoculation of the soil with Thiobacillus thiooxidans accelerated the S-oxidation, especially when organic matter was added. 6. In all experiments, S-oxidation was accompained by a decrease in pH.

Acidithiobacillus thiooxidans

Functional study of the AfRAP2 gene in Amorpha fruticosa L. tolerance to saline-alkali and drought stress.

BACKGROUND: Amorpha fruticosa L. is a leguminous shrub with high tolerance to drought, poor soil, and saline-alkali stress conditions. As a member of the family of transcription factors in higher plants, the ethylene response factor AP2/ERF plays a crucial role in both plant adaptation to abiotic stress and in growth and development. In this study, based on genes identified from the transcriptomic sequencing of Amorpha fruticosa L. under drought stress, the upregulated gene AfRAP2 was isolated from its seedlings, with the aim of elucidating its stress-response function using molecular biological techniques. RESULTS: In this study, the AfRAP2 gene was cloned from the leaves of Amorpha fruticosa L. using RT-PCR. Bioinformatics analysis revealed that AfRAP2 contains an AP2 domain and belongs to the DREB subfamily of the AP2/ERF transcription factor family, showing close phylogenetic relationships with LaEREBP from Lathyrus albus. Real-time quantitative PCR (RT-qPCR) results indicate that AfRAP2 is expressed in various tissues of Amorpha fruticosa L., with the highest expression in leaves and the lowest in stems, furthermore, its expression is significantly upregulated in roots and leaves upon induction by NaHCO3 and PEG6000. Subcellular localization experiments confirmed that the AfRAP2 protein is localized to the nucleus, and GUS histochemical staining assay revealed that its promoter drives GUS expression in anthers. Resistance analysis of overexpressing yeast strains showed that yeast transformed with the AfRAP2 gene exhibited significantly better growth under sorbitol, mannitol, and NaHCO3 stress conditions compared to the control, indicating that this gene enhances yeast tolerance to drought and saline-alkali stress. We screened transgenic tobacco and Populus davidiana × P. alba var. Pyramidalis. The results showed that under natural drought and saline-alkali stress treatments, the transgenic lines exhibited significantly improved growth and higher activities of the physiological indicators of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) compared with wild-type plants, indicating that the overexpression of the AfRAP2 gene plays a key role in the response to saline-alkali stress and drought stress. CONCLUSION: In summary, AfRAP2 contains an AP2 domain and belongs to the DREB subfamily of transcription factors, under abiotic stress induced by NaHCO₃ and mannitol, it can induce the expression of the AfRAP2 gene in tobacco and Populus davidiana×P. alba var. pyramidalis. AfRAP2 plays a vital role in the plant response to saline-alkali stress and drought stress and is a promising candidate gene for stress-tolerant breeding.

Plant Proteins

Hypoosmolarity inhibits ammonia oxidation by terrestrial and freshwater Nitrosopumilaceae members.

Salinity strongly influences the physiology and distribution of nitrifying microorganisms, yet the effects of low salinity remain understudied. This study investigates the impact of hypoosmolarity on different groups of ammonia oxidizers in soil and freshwater reservoirs, as well as in pure culture isolates. In soil microcosms amended with ammonium, at low salinity levels (~120 μS/cm), comparable to values commonly found in pristine terrestrial and freshwater environments, the abundance of ammonia-oxidizing bacteria (AOB), dominated by Nitrosomonas oligotropha, significantly increased. In contrast, the growth of ammonia-oxidizing archaea (AOA), dominated by "Candidatus Nitrosotenuis" of the Nitrosopumilaceae family, was stimulated by high salinity (~760 μS/cm). In ammonium-fed freshwater microcosms, the abundance of AOB, dominated by N. oligotropha, significantly increased under both low (~170 μS/cm) and high salinity (~850 μS/cm) conditions. In the presence of allylthiourea (50 μM), used to inhibit bacterial ammonia oxidation, AOA were sensitive to low salinity in both soil and freshwater microcosms. Consistently, culture-dependent studies revealed marked growth inhibition of terrestrial AOA, especially members of Nitrosopumilaceae, under hypoosmolarity, unlike AOB and complete ammonia oxidizer (comammox) strains. Genomic analyses, along with transcriptomic studies, suggested that the sensitivity of AOA to hypoosmolarity stress was possibly due to a lack of osmoregulatory transport systems and their S-layer cell wall structure. Overall, this study indicates hypoosmolarity as an important factor shaping the ecological niches and distribution of ammonia oxidizers, as well as nitrification activities, in terrestrial and freshwater environments that are increasingly affected by intensified water cycles due to global change.

Ammonia

Advances in Understanding Salt Stress Effects on Growth and Productivity in Sorghum (Sorghum bicolor L. Moench).

Salinity is a growing problem for cereal cultivation because it imposes multiple stresses, including osmotic, ionic, nutritional, and oxidative constraints, on the crop. Sorghum (Sorghum bicolor L. Moench) is considered a climate-smart C4 cereal for food, feed, fodder, forage, and bioenergy, but recent studies indicate that salinity continues to hinder establishment, biomass formation, reproductive growth, and yield. This review compiles the literature on the impacts of salinity on sorghum from 2021 to 2026, with a focus on germination, vegetative growth, physiological and biochemical responses, ion homeostasis, genetic control, productivity, mitigation, and future breeding priorities. In total, 160 records were identified, 118 records were screened after duplicate removal, and 44 recent sources were included in the synthesis. Across comparable sorghum studies, saline/NaCl treatments of approximately 60-200 mM commonly reduced germination by about 20-40%, root and shoot elongation by 25-50%, and biomass by 20-55%, while tolerant genotypes generally maintained higher K+/Na+ balance, 40-60% greater biomass retention, or two- to five-fold stronger ion homeostasis indicators than sensitive lines under similar conditions. Salt stress also lowers leaf expansion, chlorophyll stability, gas exchange, dry matter accumulation, panicle fertility, and grain filling. Tolerant genotypes show greater antioxidant potential, osmotic adjustment, photosynthetic stability, and root system resilience. Recent omics and genome-wide association studies suggest that salinity tolerance in sorghum is polygenic and involves genes related to ion transport, stress signalling, antioxidant regulation, osmolyte metabolism, and growth maintenance. This review recommends a shift from descriptive trait lists to full-cycle field validation, multi-trait selection indices, and integrated packages combining breeding with seed priming, soil water management, amendments, and beneficial microorganisms.

PRISMA

Wound cleansing by high pressure irrigation.

All traumatic wounds are contaminated to some degree by both soil and bacteria. Specific infection potentiating factors in soil impair the defenses of the tissue and invite infection. These factors are small in size and resist removal by low pressure irrigation. The efficiency of wound irrigation is markedly improved by delivering the irrigant to the wound under continuous high pressure. Irrigation of the wound with saline solution delivered at 15 pounds per square inch removed 84.8 per cent of the soil infection potentiating factors from the wound. The residual infection potentiating factors remaining in the wound did not significantly impair tissue defenses. On the basis of these experimental studies, clinical studies are now being initiated to test the therapeutic value of high pressure irrigation in traumatic wounds in humans.

Animals

Chemical and physical microenvironments at the Viking landing sites.

Physical and chemical considerations permit the division of the near-surface regolith on Mars into at least six zones of distinct microenvironments. The zones are euphotic, duricrust/peds, tempofrost, permafrost, endolithic, and interfacial/transitional. Microenvironments vary significantly in temperature extremes, mean temperature, salt content, relative pressure of water vapor, UV and visible light irradiance, and exposure to ionizing radiation events (100 Mrad) and oxidative molecular species. From what is known of the chemistry of the atmosphere and regolith fines (soil), limits upon the aqueous chemistry of soil pastes may be estimated. Heat of wetting could reach 45 cal/g dry soil; initial pH is indeterminate between 1 and 10; ionic strength and salinity are predicted to be extremely high; freezing point depression is inadequate to provide quantities of liquid water except in special cases. The prospects for biotic survival are grim by terrestrial standards, but the extremes of biological resiliency are inaccessible to evaluation. Second-generation in situ experiments which will better define Martian microenvironments are clearly possible. Antarctic dry valleys are approximations to Martian conditions, but deviate significantly by at least half-a-dozen criteria.

Chemical Phenomena

The effect of osmotic pressure and salinity of the medium on the growth and sporulation of Aspergillus niger and Paecilomyces lilacinum species.

The effect of osmotic pressure and salinity on the production of conidia and growth of Aspergillus niger and Paecilomyces lilacinum, isolated from the soil, have been studied in this investigation. The maximum production of conidia in both species was observed in the nutrient medium containing 1% NaCl wheras maximum growth was recorded in the nutrient medium containing 3% NaCl. It has been thus observed that the salinity and the osmotic pressure related to it effect the reproductive as well as the vegetative development of both species, and these effects have been observed to be different. The sensitivity of both fungal species to the salt was also investigated. Conidia were not observed in the P. lilacinum species grown in nutrient medium with 5% NaCl whereas conidial development did take place in the case of Aspergillus niger grown in the nutrient medium containing 5% NaCl.

Aspergillus niger

Sulfide-oxidizing potential and hypersalinity tolerance strategies in salt-crust covered coastal microbial mats.

Hypersaline microbial mats are dense microbial ecosystems capable of performing nearly complete element cycling under harsh conditions including near-saturation salinity. Our previous study of salt-crust-covered microbial mats showed that oxygenic photosynthesis was inhibited at salt saturation, while phototrophic sulfide oxidation persisted despite well-known sulfide-oxidizing taxa being undetectable. In this study, we analyzed metagenome-assembled genomes (MAGs) from the same mats to identify sulfide-oxidizing taxa and adaptations enabling oxygenic phototrophs to survive salt saturation. We extended the dataset by including morphologically identical mats exposed to lower salinity regimes to identify metabolic capabilities specifically selected for by saturation-level salinity. The phototrophic sulfide oxidation capability was found in nearly all cyanobacterial MAGs, in some Chloroflexota, and in abundant Rhodovibrio populations previously not known to oxidize sulfide. Furthermore, we found clear indications of Haloarchaea-like potassium-based osmoregulation in Bradymonadaceae (Myxococcota) adding another taxon to the few known potassium-accumulating bacteria. Despite lower oxygen concentrations, salt-crust-covered mats showed smaller proportions of fermenters and higher proportions of aerobic microorganisms than lower-salinity mats. We compared the genetic signatures of hypersalinity and desiccation tolerance in cyanobacterial MAGs from this study to genomes from desiccation-prone environments such as desert soils and small freshwater streams. Genomes of hyperhalophilic cyanobacteria were characterized by lack of certain potassium transporters and catalase genes and presence of additional osmolyte transporter subunits and sulfide-oxidation genes. We hypothesize that during salt saturation the oxidative stress for mat dwelling cyanobacteria is lowered, while the ability to oxidize sulfide provides them with energy when oxygenic photosynthesis is inhibited.

Oxidation-Reduction

Genomic exploration of Bacillus paralicheniformis TB197: an agrobiotechnological tool from the Sonoran Desert.

Climate change and the harmful effects of extensive agrochemical use for plant nutrition and pest control on soils, the environment, and human health are driving the search for sustainable alternatives that reduce their use while increasing plant resilience. In regenerative agriculture, microorganisms have become valuable tools, acting as biological control agents or biostimulants, such as plant growth-promoting rhizobacteria, and/or to enhance plant performance under abiotic stress. The genus Bacillus is well known for its versatile interactions with plants. Specifically, Bacillus paralicheniformis TB197 has demonstrated high efficacy in controlling phytopathogenic nematodes and adapting to diverse soil and crop conditions. Based on these traits, we explored the agricultural potential of this strain through genomic analysis and in vitro and in vivo assays. Gene analysis identified functions related to three main areas: (i) stress resistance and plant colonization, (ii) plant growth promotion, and (iii) phytopathogen control. The strain showed high tolerance to salinity and temperature, promoted plant growth, and exhibited strong antifungal activity. These findings highlight the potential of the TB197 strain as a promising candidate for developing next-generation bioinoculants.IMPORTANCEThe use of beneficial microorganisms is a pivotal strategy for mitigating the environmental impacts of intensive agriculture while preserving crop productivity. Bacillus paralicheniformis TB197 is a native desert soil bacterium with genetic traits associated with stress tolerance, plant growth promotion, and suppression of plant pathogens. In this study, we employed a multifaceted approach integrating genomic analysis and functional assays to demonstrate the strain's multifunctional potential as an agricultural bioinoculant. The results of the study demonstrate that a singular bacterial strain can integrate multiple beneficial functions relevant to sustainable agriculture. This work contributes to the field of applied microbiology by expanding the understanding of how environmentally adapted bacteria can serve as biological alternatives to chemical inputs in agroecosystems.

Bacillus

In vitro survival of human pathogenic fungi in Hawaiian beach sand.

In vitro studies utilizing 4 pathogenic fungi, Trichosporon cutaneum, Candida albicans, Microsporum gypseum and Trichophyton mentagrophytes, all known from Hawaiian beaches, indicate that they survive in the fluctuating beach habitat where they can serve as potential sources of infection for significant periods of time. Survival was measured by testing the viability of propagules at intervals for 6 months. All species survived 6 months under 1 or more experimental conditions. Survival patterns showed both increases and decreases depending upon the given parameters designed to simulate various beach conditions. Propagules inoculated on hair and horn (keratinized inoculum) did not remain viable longer than propagules from pure culture suspensions (non-keratinized). Microbial antagonism was not a major factor in survival. All species survived at least 1 month in non-sterile sand inoculated with keratinized propagules. This condition approximated the natural sand habitat. Alternate wetting and drying of sand caused an overall decrease in survival time except for M. gypseum (non-keratinized inoculum) at 37 degrees C in sterile sand and T. mentagrophytes (keratinized inoculum) at 37 degrees C in non-sterile sand. Temperature was important: increasing temperature resulted in a general decrease in survival time; 45 degrees C was definitely inhibitory, with the exception of T. cutaneum which survived that level for 6 months (keratinized inoculum). Salinity did not influence survival.

Candida albicans

Evaluation of wound irrigation by pulsatile jet and conventional methods.

Irrigation of wounds to remove bacteria and foreign material is an essential of wound management along with debridement. The effectiveness of saline lavage by high pressure (50 psi) pulsatile jet irrigation has been compared with conventional gravity flow and bulb syringe procedures. Experimental paravertebral incisional surface wounds in 234 randomized rats were either clean or traumatized and soiled. Wounds in 200 of the rats were seeded with E. coli (log 8.80). Swab specimens of each wound were taken at incision, after seeding, after irrigation, and at three, seven, and ten days after closure. Eulates of more than 1600 specimens were cultured. No anaerobes were found. Irrigation diminished bacterial counts in all wounds, but only pulsatile jet irrigation brought about significant (P less than 0.05) reduction of bacteria in each type of wound. After three days E. coli was significantly diminished in all wounds, regardless of irrigation or none, owing to host defense mechanisms. Nevertheless, clean contaminated wounds were infected at three days but not at seven days after lavage, while traumatized wounds remained infected at ten days except for those initially irrigated by pulsatile jet. Thus, pulsatile jet irrigation removed bacterial from experimental wounds more efficiently than conventional procedures.

Animals