Letters in Applied Microbiology最新文献

Crop residue management is vital in the Rice-Wheat cropping system, influencing soil health and crop productivity. This study examined the effects of organic and inorganic fertilizers and microbial decomposers on rice growth and yield. We evaluated seven treatments: 100% recommended dose fertilizer (RDF); 50% residue + 50% RDF; 50% residue + 50% RDF + Pusa decomposer; 50% residue + 50% Green Manuring (GM)/Green Leaf Manuring (GLM); 50% residue + 50% GM/GLM + Pusa decomposer; Residue @ 2.5 tons per acre + Pusa decomposer; Residue @ 2.5 tons per acre + no Pusa decomposer; and absolute control. Results indicate that integrating organic and inorganic fertilizers with microbial decomposers positively affects rice growth and yield parameters. While adding microbial decomposer to RDF did not consistently enhance rice yield, it improved soil enzymatic properties. This suggests that the effectiveness of microbial decomposers may vary based on specific soil and crop conditions. Therefore, microbial decomposers present a promising approach to boost soil health and fertility. Further research is needed to optimize conditions for their use and systematically assess their impact on crop yields.

Precise and timely diagnosis is essential to prevent severe outcomes of leptospirosis in humans and animals. Existing diagnostic methods face challenges and limitations, underscoring the need for novel, field-applicable screening, and diagnostic tests/assays. This study evaluates the diagnostic utility of a recombinant ErpY-like lipoprotein (rErpY-LIC11966) in a latex agglutination test (LAT) for diagnosis of animal leptospirosis. The ErpY gene sequence from Leptospira interrogans serovar Pomona, excluding the signal peptide, was amplified, cloned into the pETite vector, and expressed in Escherichia coli. The expressed rErpY (∼16 kDa) was characterized by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis and Western blot using Leptospira-specific standard sera. To assess the diagnostic potential of rErpY, Ni-NTA affinity-purified protein was used to sensitize latex-coated beads (0.8 µm colour beads), which were then employed in the LAT for standardization and optimization with standard positive and negative sera. For evaluation, the rErpY-LAT was tested on serum samples from 177 suspected animal cases and compared to the microscopic agglutination test. It showed a relative diagnostic sensitivity of 90.6%, a specificity of 89.1%, and an overall accuracy of 90%. This study proposes rErpY-LAT as a field testing/screening diagnostic tool for preliminary serodiagnosis of leptospirosis, highlighting the potential of recombinant protein-based assays to address current diagnostic challenges.

This study examined the feasibility of using Cellulomonas fimi and Shewanella oneidensis as microbial fuel cells fueled by starch, cellulose, chitin, and chitosan. To our knowledge, this is the first report of power generation using C. fimi fueled by these polysaccharides other than cellulose, furthermore the first report of S. oneidensis fueled by chitosan. No differences were observed in the power generation capacities between C. fimi and S. oneidensis when chitin and chitosan were used. However, C. fimi demonstrated effective power generation from starch and cellulose, showing a maximum current density of 17.4 mA m-2 for starch and 38.8 mA m-2 for cellulose. S. oneidensis could not utilize these fuels to generate electricity. Power generation using C. fimi fueled by starch and cellulose produced acetic acid, lactic acid, and formic acid. However, when chitin and chitosan were used, only acetic acid was produced. These results indicate that electron transfer from C. fimi to the anode may be inefficient. The accumulation of organic acid in the anode solution indicates insufficient electron transfer to the anode. To improve power generation efficiency, it may be necessary to enhance electron transfer from the cells to the anode, for example, by adding a mediator.

From marine to terrestrial environments, Pseudomonas spp. exhibit a remarkable ability not only to adapt but also thrive even amidst adverse conditions. This fact turns Pseudomonas spp. into one of the most prominent candidates for novel biotechnological solutions. Even though terrestrial isolates have been extensively studied, there is still an almost untapped source to be explored in marine Pseudomonas. Harnessing such strains offers an opportunity to discover novel bioactive compounds that could address current global challenges in healthcare and sustainable development. Therefore, this minireview aimed to provide an overview of the main recent discoveries regarding antimicrobials, antifouling, enzymes, pigments, and bioremediation strategies derived from marine isolates of Pseudomonas spp. Future research perspectives will also be discussed to foster forthcoming endeavors to explore the marine counterparts of such a prolific bacterial genus.

Postbiotic lactate modulates the immune system in inflammatory bowel diseases. However, its role in experimental intestinal mucositis (IM) has not been elucidated. This study aimed to evaluate the effects of lactate supplementation (1 and 2 × 10-1 mol/l) in a 5-fluorouracil (5-FU)-induced IM model. Male BALB/c mice (6-8 weeks old) were randomly divided into four groups: control (CTL), mucositis (MUC), mucositis with 1 × 10-1 mol/l lactate solution (MUC10), and mucositis with 2 × 10-1 mol/l lactate solution (MUC200). Lactate was administered via oral gavage for 10 days. Following the treatment period, the animals were subjected to an intraperitoneal injection of 300 mg/kg 5-FU to induce IM and were euthanized 72 h later for analysis. The MUC group presented intestinal damage with a poor histological score and decreased morphometric parameters as well as decreased mucus production and increased inflammatory infiltration and intestinal permeability compared to those of the CTL group (P < .05). However, the MUC200 group exhibited better results for the evaluated parameters than the MUC group (P < .05). Notably, the results in the MUC10 group were similar to those in the MUC group (P > .05). In conclusion, lactate supplementation attenuates mucositis-induced damage in a dose-dependent manner.

The food industry faces numerous challenges today, with the prevention and reduction of microbial contamination being a critical focus. While traditional chemical-based methods are effective and widely used, rising energy costs, the development of microbial tolerances, and growing awareness of the ecological impact of chemical biocides have renewed interest in novel biocides. Ozone, in both its gaseous and aqueous forms, is recognized as a potent disinfectant against bacteria, viruses, and fungi due to its high oxidation potential. Our review highlights several studies on the applications of ozone within the food industry, including its use for surface and aerosol disinfection and its capacity to reduce viable Listeria monocytogenes, a pertinent foodborne pathogen harbouring environmental and biocide stress tolerances and biofilm former. We also explore the use of ozone in food treatment and preservation, specifically on blueberries, apples, carrots, cabbage, and cherry tomatoes. While ozone is an effective disinfectant, it is important to consider material incompatibility, and the risks associated with prolonged human exposure to high concentrations. Nevertheless, for certain applications, ozone proves to be an efficacious and valuable alternative or complementary method for microbial control. Compliance with the biocide products regulation will require ozone device manufacturers to produce proven efficacy and safety data in line with British standards based on European standards (BS EN), and researchers to propose adaptations to account for ozone's unique properties.

Despite the advent of Xpert MTB/RIF, pleural tuberculosis (TB) diagnosis in pleural fluid is still difficult. Hence, we assessed the diagnostic efficacy of its advanced version, Xpert MTB/RIF Ultra for pleural TB diagnosis using pleural fluid as sample. Tuberculosis pleuritis (TBP) suspects (n = 261) were enrolled in the study of which 29 were excluded. The remaining patients (n = 232) were categorized into definite TBP (n = 31), probable TBP (n = 28), and non-TB controls (n = 173) based on composite reference standard consisting of smear, culture, histopathology, and Xpert MTB/RIF as well as follow up/clinical response to anti-tuberculosis therapy. Among the TBP suspects, 59 were diagnosed as TBP patients. The sensitivity of Xpert MTB/RIF Ultra (52.5%) using pleural fluid for TBP diagnosis was higher than sensitivity obtained with smear (22.4%), culture (17.6%), and Xpert MTB/RIF (25%) alone, carried using either pleural fluid or pleural biopsy or both the samples. In cases of probable TBP, where none of the laboratory tests were positive, Xpert MTB/RIF Ultra use led to an increased diagnostic percentage of definite TBP from 52.5% to 69.4% Overall, the Xpert MTB/RIF Ultra showed promising results for a definitive diagnosis of TBP in pleural fluid samples.

Biofilm-mediated osteomyelitis presents significant therapeutic challenges. Given the limitations of existing osteomyelitis treatment approaches, there is a distinct need to develop a localized drug delivery system that is biocompatible, biodegradable, and capable of controlled antibiotic release. Multivesicular liposomes (MVLs), characterized by their non-concentric vesicular structure, distinct composition, and enhanced stability, serve as the system for a robust sustained-release drug delivery platform. In this study, various hydrogel formulations composed of poloxamer 407 and other hydrogels, incorporating vancomycin hydrochloride (VAN HL)-loaded MVLs (VAN HL-MVLs), were prepared and evaluated. The optimized VAN HL-MVL sol-gel system, consisting of poloxamer 407 and hyaluronic acid, successfully maintained drug release for up to 3 weeks and exhibited shear-thinning behavior at 37°C. While complete drug release from MVLs alone took place in 312 h, the hydrogel formulation extended this release to 504 h. The released drug effectively inhibited the Staphylococcus aureus biofilms growth within 24 h and methicillin-resistant S. aureus biofilms within 72 h. It also eradicated preformed biofilms of S. aureus and methicillin-resistant S. aureus in 96 and 120 h, respectively. This injectable in situ gel system incorporating VAN HL-MVLs holds potential as an alternative to undergoing multiple surgeries for osteomyelitis treatment and warrants further studies.

Legionnaires' disease (LD) is a severe and potentially fatal form of bacterial pneumonia caused by Legionella spp. We evaluated the use of UV-light for detecting Legionella non-pneumophila in water samples according to the NEN-EN-ISO 11731:2017 methodology (reference method) in a collaborative effort involving 10 laboratories. First, a test panel was constructed of 298 strains: 157 Legionella strains and 141 non-Legionella strains were cultured on buffered charcoal yeast extract (BCYE)-medium and confirmed according to ISO 11731: 2017 (cultured on BCYE agar plates with and without l-cysteine), and by matrix-assisted laser desorption-ionization time of flight or next generation sequencing. All strains were additionally exposed to an UV-light to assess if they showed a bright blue fluorescence effect (UV-positive) or not (UV-negative). Second, in an interlaboratory study, 10 laboratories analyzed a blinded set of 16 Legionella strains and 8 non-Legionella strains using both methods. The test panel analyses showed 100% accordance between the UV-light and reference method. In addition, the interlaboratory study results showed full agreement between both methods. Our results support the implementation of UV-light detection to confirm Legionella presumptive colonies during analyses of water samples according to the NEN-EN-ISO 11731:2017 methodology. Implementation of UV-light confirmation could reduce workload, time-to-result and costs for the analyses of water samples for the presence of Legionella.