Indian Journal of Microbiology最新文献

Carbapenem resistance represents a pressing public health concern, posing significant challenges due to limited treatment options and escalating mortality rates. In India, the prevalence of carbapenem resistance among Enterobacteriaceae ranges between 18 to 31%, causing severe infections such as bloodstream infections, pneumonia, urinary tract infections, and intra-abdominal infections. Accurate and timely diagnosis, particularly for Enterobacteriaceae producing carbapenemase, is crucial for effective clinical prophylaxis of critical care patients as they are considered as a last resort of therapy. Various genotypic and non-genotypic detection methods have been developed over the past decade, their limitations in terms of sensitivity and specificity have led the exploration of innovative technologies. Advanced opportunities for carbapenem resistance detection using microfluidic-based biosensors have miniaturized various biomedical devices. This enables the use of less sample and reagents, cheap pricing, automation, screening, and improved detection. Despite ongoing research and development, the adoption of these biosensors in healthcare settings is limited due to the lack of awareness and understanding of their efficiency. Therefore, this review primarily focuses on the advantages and limitations of all biosensor-based devices over existing methods for the detection of carbapenem resistance in gram negative bacilli. These biosensors represent substantial advancements in combating carbapenem resistance, providing promise for more reliable and accurate diagnostic techniques that may eventually improve patient care and infection control.

To investigate the characteristics and risk factors of cytomegalovirus (CMV) infection in patients with dermatomyositis (DM) and explore whether CMV infection plays a role in the prognosis of patients with DM. The retrospective reviewed patients with DM admitted to the hospital from October 2017 to June 2022 and the enrolled patients who were assessed for CMV infection. The clinical characteristics and prognosis of the patients with CMV infection were compared to those without CMV. Of the 181 patients with DM, 53 (29.2%) suffered from CMV infection. The prevalence of CMV infection in the anti-MDA5( +) DM group was higher than it was in the anti-MDA5(-) DM group (38.7% vs. 16.0%, P = 0.001). Multivariate analyses demonstrated that the ILD (OR 5.11, 95% CI 1.74–15.26, P = 0.003), other infections (OR 6.24, 95% CI 1.63–23.89, P = 0.007), the cumulative dose of glucocorticoids (OR 5.19, 95% CI 2.44–11.02, P < 0.001), usage of CTX (OR 8.49, 95% CI 2.28–31.54, P = 0.001), ALB ≦ 30 g/L (OR 3.19, 95% CI 1.03–9.85, P = 0.043) were independent risk factors for CMV infection in patients with DM. Patients in the CMV-infection group showed significantly higher incidences of other infections than those in the CMV-infection-negative group. Higher mortality was observed in the CMV infection group than in the without CMV infection group. CMV infection occurred in patients with DM frequently and was found to be relevant to death. The cumulative dose of glucocorticoids, ILD, useage of CTX, hypoproteinemia, and other infections were contributing factors in the development of CMV infection in patieents with DM.

In this study, soil samples from textile industries located in the Arba Minch region were collected and screened for the presence of heavy-metal-resistant fungi. Among the three isolates identified during the screening process, Aspergillus flavus exhibited the highest resistance to heavy metals such as Cr (VI) and Mn (II). Our results showed that A. flavus biosorbed Mn and Cr at concentrations of 80.5% and 68.4%, respectively, making it a promising biosorbing agent. Furthermore, our study demonstrated that pretreatment of A. flavus fungal biomass with NaOH enhanced the biosorption of Mn and Cr. To optimize the biosorption process, a study was conducted using A. flavus biomass with three independent variables: pH (2–10), biomass dosage (1–5 g/mL), and contact time (40–150 min). The Box-Behnken experimental design was used to determine the optimal biosorption values. Maximum biosorption was achieved at pH 10, biomass dosage (5 g/mL), and contact time of 150 min. These conditions resulted in 88 and 80.29% sorption efficiency for manganese and chromium ions, respectively, by A. flavus biomass. The scanning electron microscopic analysis of A. flavus biomass indicated the presence of large porosities on the microbial surface due to NaOH treatment, which assisted in the higher sorption of heavy metals.

C-Phycocyanin (C-PC), is a natural blue pigment found mainly in cyanobacteria. Due to its extraordinary spectral properties and unique health benefits, this pigment has attracted significant attention in various industries. C-PC is widely studied and reported to have different pharmacological properties, notably antioxidant, anti-inflammatory, anti-cancer, neuroprotective, and hepatoprotective activities. Commercial exploitation of cyanobacterial phycocyanin relies on mass cultivation of selected cyanobacteria using different strategies like phototrophic, heterotrophic, mixotrophic, two-stage, open, and closed systems. Nonetheless, the production is influenced by different environmental factors especially light, pH and temperature as well as the availability of high yielding strains. Some of the bottlenecks like breaking the genetic barrier of sub-optimal yield or response to environmental factors can be addressed by genetic and metabolic engineering using advanced molecular tools. The present review discusses the production and application of C-PC along with possible molecular interventions to improve C-PC production. We have also discussed how strain improvement and diversified application can harness the commercial potential of C-PC in future to a greater extent.

The current study is based on the synthesis of silver nanoparticles using Aspergillus fumigatus and its larvicidal activity against Aedes aegyptii. The optical, morphological, structural, and elemental properties of synthesized silver nanoparticles were investigated by UV–Vis spectroscopy, Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Energy-dispersive X-ray analysis (EDX) and Zeta potential. The characterization was confirmed by the surface plasmon resonance band at 434 nm. The results validated the spherical shape and size (28–33 nm) of the nanoparticles. Biosynthesized silver nanoparticles (AgNPs) have been evaluated for their effectiveness in controlling Aedes aegyptii larvae. The larvicidal effect was evident in the experiment when Aedes larvae were exposed to five different log concentrations of Aspergillus fumigatus based-AgNPs. The mortality in the larvae had been observed at various exposure times. Exposure of third instar larvae of Aedes aegypti to biosynthesized silver nanoparticles resulted in lethal concentrations (LC₅₀ and LC₉₀) of 2.624 and 4.728 ppm, respectively. Moreover, the biotoxicity screening against non-target organism Daphnia magna revealed the nontoxic nature of biogenic nanosilver against non-target fauna. The findings indicate that Aspergillus fumigatus has the potential to facilitate the swift synthesis of silver nanoparticles, presenting a novel approach for vector control strategies, without causing any harm to other aquatic organisms occupying the same ecological niche.

Multidrug-resistant Klebsiella pneumoniae (MDR-KP) infections have become a major global issue in the healthcare sector. Alternative viable tactics for combating bacterial infections, such as the use of bacteriophages, can be considered. One of the major challenges in phage therapy is the emergence of phage-resistant bacteria. This study isolated bacteriophages from water and soil samples against MDR-KP isolates. Susceptible bacterial hosts were exposed to phages at different concentrations and prolonged durations of time to obtain phage-resistant survivors. Phenotypic changes such as changes in growth rates, biofilm formation ability, antibiotic sensitivity patterns, and outer membrane proteins (OMPs) profiling of the survivors were studied. Our findings indicate that the phage ØKp11 and ØKp26 survivors had reduced growth rates and biofilm formation ability, altered antibiotic sensitivity patterns, and reduced OMPs expression compared with the parent MDR-KP002 isolate. These results suggest that the alternations in the bacterial envelope result in phenotypic phage resistance among MDR bacterial isolates.

Microgravity is a state of free fall which one experiences in space. Human-crewed missions are becoming more sophisticated in the ongoing times. The altered gravitational conditions exert several physiological changes in the astronauts. Among many, one of the significantly affected systems and least discussed so far is the neurological system. Earlier studies have shown that exposure to space condition leads to structural changes in the brain, including distorted neurons and apoptotic astrocytes. Recent studies show the velocity of the action potential is reduced. Hippocampal activity is disrupted leading to cognitive impairment. Neuro ocular change occurs in some astronauts. Probiotics like Bacillus coagulans and Lactobacillus sp. connect gut-brain axis. Several probiotics are effective in treating neurological structural disorders. To sum up, in orbital exploration, astronauts face challenges of cosmic radiation and microgravity, impacting neuronal morphology. Chronic low-dose X-ray exposure delays neurite outgrowth and induces apoptosis. Simulated microgravity intensifies these effects, causing a significant increase in late apoptotic neurons. Astrocytes exposed to microgravity undergo apoptosis, but surviving cells adapt. Microgravity induces cellular senescence in rat cells, mimicking aging. NASA Twin Study reveals cognitive declines post-microgravity. Probiotics show therapeutic potential in neurological disorders, influencing gene expression and apoptotic proteins. They alleviate neurodegeneration and delay senescence, emphasizing their role in neurological well-being. In this review we discuss baseline data in this area since few laboratories has started working on the effect of nanoparticles on probiotics under microgravity. This review would help us and others interested in this field worldwide to work cohesively in future.

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Hydrogen (H₂), a clean and versatile energy carrier, has recently gained significant attention as a potential solution for reducing carbon emissions and promoting sustainable energy systems. The yield and efficiency of the biological H₂ production process primarily depend on sterilization conditions. Various strategies, such as heat inactivation and membrane-based sterilization, have been used to achieve desirable yields via microbial fermentation. Almost every failed biotransformation process is linked to nonsterile conditions at any reaction stage. Therefore, the production of renewable biofuels as alternatives to fossil fuels is more attractive. Pure sugars have been widely documented as a costly feedstock for H₂ production under sterile conditions. Biotransformation under nonsterile conditions is more desirable for stable and sustainable operation. Low-cost feeds, such as biowaste, are considered suitable alternatives, but they require appropriate sterilization to overcome the limitations of inherited or contaminating microbes during H₂ production. This article describes the status of microbial fermentative processes for H₂ production under nonsterile conditions and discusses strategies to improve such processes for sustainable, cleaner production.

Microbes in the rhizosphere play a significant role in the growth, development, and efficiency of plants and trees. The rhizospheric area's microbes are reliant on the soil's characteristics and the substances that the plants release. The majority of previous research on medicinal plants concentrated on their bioactive phytochemicals, but this is changing now that it is understood that a large proportion of phytotherapeutic substances are actually created by related microorganisms or through contact with their host. The roots of medicinal plants secrete a large number of secondary metabolites that determine the diversity of microbial communities in their rhizosphere. The dominant bacteria isolated from a variety of medicinal plants include various species of Bacillus, Rhizobium, Pseudomonas, Azotobacter, Burkholderia, Enterobacte, Microbacterium, Serratia, Burkholderia, and Beijerinckia. Actinobacteria also colonize the rhizosphere of medicinal plants that release low molecular weight organic solute that facilitate the solubilisation of inorganic phosphate. Root exudates of medicinal plants resist abiotic stress and accumulate in soil to produce autotoxic effects that exhibit strong obstacles to continuous cropping. Although having a vast bioresource that may be used in agriculture and modern medicine, medicinal plants' microbiomes are largely unknown. The purpose of this review is to (i) Present new insights into the plant microbiome with a focus on medicinal plants, (ii) Provide information about the components of medicinal plants derived from plants and microbes, and (iii) Discuss options for promoting plant growth and protecting plants for commercial cultivation of medicinal plants. The scientific community has paid a lot of attention to the use of rhizobacteria, particularly plant growth-promoting rhizobacteria (PGPR), as an alternative to chemical pesticides. By a variety of processes, these rhizobacteria support plant growth, manage plant pests, and foster resilience to a range of abiotic challenges. It also focuses on how PGPR inoculation affects plant growth and survival in stressful environments.

In this study, 13 diesel degrading bacteria were isolated from the oil contaminated soils and the promising strains identified as Acinetobacter pittii ED1 and Pseudomonas aeruginosa BN were evaluated for their diesel degrading capabilities. These strains degraded the diesel optimally at 30 °C, pH 7.0 and 1% diesel concentration. Both the strains produced biofilm at 1% diesel concentration indicating their ability to tolerate diesel induced abiotic stress. Gravimetric analysis of the spent medium after 7 days of incubation showed that A. pittii ED1 and P. aeruginosa BN degraded 68.61% and 76% diesel, respectively, while biodegradation reached more than 90% after 21 days. Fourier Transform Infrared (FTIR) analysis of the degraded diesel showed 1636.67 cm⁻¹ (C=C stretch, N–H bond) peak corresponding to alkenes and primary amines, while GC-TOF-MS analysis showed decline in hydrocarbon intensities after 7 days of incubation. The present study revealed that newly isolated A. pittii ED1 and P. aeruginosa BN were able to degrade diesel hydrocarbons (C11–C18, and C19–C24) efficiently and have potential for bioremediation of the oil-contaminated sites.