Current Microbiology

Chaturvedi, Priyanka; Pathak, Rimjhim; Dayal, Ranu; Parihar, Himani; Kathireshan, Alagapuram K.; Tirumalai, Prem S.

doi: 10.1007/s00284-025-04297-9pmid: 40533631

Despite recent advancements in cancer treatment, colon cancer remains one of the most commonly diagnosed and deadliest cancers worldwide, with significantly increasing incidence rates in developing countries. Numerous studies using in vitro and animal models have explored the potential mechanisms through which probiotics may help prevent colorectal cancer (CRC). Among the most studied probiotic species are those belonging to the Lactobacillus and Bifidobacterium genera. The proposed anti-CRC mechanisms include direct interaction with the intestinal mucosa, such as probiotic adherence and competitive exclusion of harmful microbes, as well as antagonism against pathogens through the action of lactic acid bacteria. Probiotics have also been shown to bind mutagens and carcinogens, and to inhibit the activity of β-glucuronidase—an enzyme linked to damage of colon cells. There is growing evidence supporting the immunomodulatory role of probiotics in CRC prevention. This involves the secretion of beneficial metabolites and modulation of the antitumor immune response via microbiota-mediated pathways. Another proposed mechanism is the ability of probiotics to reduce secondary bile acid production, thereby influencing folate metabolism and contributing to cancer prevention. The effectiveness of probiotics in CRC prevention depends largely on the specific microbial strain. Interestingly, some studies suggest that probiotic viability may not be essential for certain anticancer effects. However, more in vivo studies—particularly human clinical trials—are needed to better understand and validate the potential roles of probiotics (both viable and non-viable), prebiotics, and synbiotics in CRC chemoprevention.

Barraza Sánchez, Jesús J.; Volpe, Sebastiano; Faraj, Santiago E.; Filomatori, Claudia V.

doi: 10.1007/s00284-025-04364-1pmid: 40616665

Alphaviruses are members of the Togaviridae family and comprise important human reemergent pathogens. They have positive-sense RNA genomes encoding both structural and non-structural proteins. Additionally, their genomes harbor diverse cis-acting RNA elements that accumulate functional information. Sequence and structural features are crucial for regulating replication, transcription, translation, and encapsidation. This review explores the multifunctional roles of these RNA elements, emphasizing their contribution to virus-host interactions, pathogenesis, and evolutionary adaptability. Key features include the 5’stem-loop and downstream elements, the subgenomic promoter, several packaging signals, a translation enhancer, the transframe and opal codons, and the 3’untranslated region. These elements collectively orchestrate the alphavirus life cycle and counteract host antiviral responses. Comparative analyses reveal structural and functional diversity across alphavirus species, reflecting evolutionary pressures from both vertebrate and invertebrate hosts. Understanding viral RNA elements provides critical insights into alphavirus molecular biology and opens new avenues for potential therapeutic strategies targeting conserved viral features.

Zhao, Yun-Xiu; Chen, Li-Wen; Shen, Yue; Chen, Hao; Yu, Zi-Yan; Xing, Chao; Chen, Yi-Fei; Zhai, Peng-Fei; Song, Jiu-Wei; Yang, Ju

doi: 10.1007/s00284-025-04326-7pmid: 40555881

Huang, Linghe; Huang, Yanxia; Jiang, Sai; Zeng, Zixian; Tan, Zhaoyang; Huang, Huaxue; Wang, Zhi; Li, Shunxiang; Wu, Dousheng; Jiang, Lin

doi: 10.1007/s00284-025-04324-9pmid: 40590908

Medicinal plants as the core component of Traditional Chinese Medicine (TCM) play a pivotal role in promoting the development of China’s TCM industry. The frequent occurrence of soil-borne diseases significantly impacts the high and stable production of these medicinal plants. Common soil-borne diseases, such as root rot, seedling blight, and gray mold, can occur in more than ten commonly used medicinal plants, leading to a substantial reduction in yield or even total crop failure. This paper provides a comprehensive review of the types and pathogenic mechanisms of common soil-borne diseases during the cultivation of medicinal plants. It discusses chemical, biological, physical, and other control strategies and their current development status for soil-borne diseases. The paper also offers insights into existing challenges in the prevention and control of soil-borne diseases in medicinal plants, aiming to inform green prevention and control practices.

Kumar, Bhavnesh; Sharma, Divakar; Venkatesan, Krishnamurthy; Bisht, Deepa

doi: 10.1007/s00284-025-04341-8pmid: 40608075

Pharmacoproteomics enables the actual status of the drug-induced conditions at the protein level. Aminoglycosides have been a major component of second-line anti-TB therapy and with a well-known mechanism to inhibit protein synthesis in bacteria by interacting with several steps of the translational process. Researchers suggested the benefit of treating antibiotic-resistant M. tuberculosis strains with the same antibiotics at an effective and safe level. In this study, we analyzed the pharmaco-proteomic effects of aminoglycosides on eight drug-resistant clinical isolates by 2DE coupled with MALDI-TOF MS. Further, bioinformatics tools have been employed to characterize the protein-antibiotic interactions. This study revealed that nine proteins showed consistently increased intensities under drug pressure. 60 kDa chaperonin1 (Rv3417c) is a heat shock protein (Hsp) that plays a key role in the survival of bacilli under stress conditions. Elongation factor Tu (Rv0685) promotes GTP-dependent binding of aminoacyl-tRNA to the A-site of the ribosome during protein biosynthesis. Dihydrolipoyl dehydrogenase (Rv0462) is involved in energy metabolism. Ribosome recycling factor Rv2882c is responsible for increasing the efficiency of translation by recycling ribosomes from one round of translation to another. Proteasome subunit beta (Rv2110c) is involved in protein degradation. Antigen 85-A precursor (Rv3804c) is involved in cell-wall mycoloylation. Three proteins (Rv2623, Rv3389c, and Rv2744c) were identified with unknown functions. Overexpressed proteins and pathways could be directly/indirectly involved in aminoglycoside resistance. Bioinformatics revealed that three proteins of unknown functions showed good binding with aminoglycosides, suggesting their direct/indirect role in resistance, and need further exploration.

Raimi, Adekunle; Horn, Suranie; Pieters, Rialet; Adeleke, Rasheed

doi: 10.1007/s00284-025-04356-1pmid: 40637870

Beneficial microbes, including endophytic bacteria, are widely used in bioformulation to improve crop productivity. However, the microbes are rarely assessed for their virulence properties. Thus, this study evaluates bacterial endophytes from vegetables for their hemolytic, antibiotic, cytotoxic activity, and ability to colonise and promote spinach (Spinacia oleracea) growth. Colonisation was assessed by visualising mCherry plasmid-tagged endophytic bacteria within plant tissues using a confocal microscope. Results showed that endophytic Pseudomonas azotoformans, Enterobacter bugandensis, Bacillus cereus and Serratia marcescens were non-hemolytic, sensitive to antibiotics, with high antibacterial and very slow cytotoxic activity, suggesting their nonvirulence and biocontrol potential. These bacteria had the highest and fastest rate of promoting seed germination and colonised the spinach leaves in a greenhouse experiment, as revealed by the visualised red fluorescence of the mCherry-plasmid transformed endophytes. Spinach inoculated with E. bugandensis and S. marcescens had higher total chlorophyll, but lower growth parameters compared to P. azotoformans and B. cereus. The root length, fresh weight and dry weight were higher in plants inoculated with P. azotoformans compared to the control and other endophytes. While endophytes with virulence potential may present health implications when consumed by humans, the nonvirulent and plant growth-promoting endophytes have applications in microbial formulation. Overall, beneficial endophytes present valuable resources in inoculum production for sustainable crop production.

Zhang, Shuang; Qu, Limin; Yuan, Meihua; Liu, Tao; Sun, Xindi; Yan, Lei

doi: 10.1007/s00284-025-04347-2pmid: 40586984

Acidithiobacillus ferrooxidans (A. ferrooxidans) is a widely studied acidophilic prokaryote primarily found in natural low-pH environments by fixing carbon dioxide and nitrogen and drives ecological succession in acidic biotopes. As a key microorganism in bioleaching and biocorrosion processes, A. ferrooxidans demonstrate unique capabilities in synthesizing both intracellular magnetite and various extracellular secondary minerals. Understanding the synthesis mechanisms and characterizing the composition of these secondary minerals are of significant scientific importance. In this study, we briefly introduced the physico-chemical characteristics of A. ferrooxidans, with emphasis on summarizing the information regarding its biomineralization as investigated through microscopic, spectroscopic, and coupled analytical techniques. Additionally, the properties and potential applications of the inorganic minerals produced by A. ferrooxidans-mediated were reviewed. Finally, we discussed possible future research directions and development prospects for the application of spectroscopy in studying inorganic minerals synthesized by A. ferrooxidans.

Elkhouli, Rania R.; ElBaghdady, Khaled Z.; Khalil, Mostafa M. H.; Mohamed, Samar S.

doi: 10.1007/s00284-025-04299-7pmid: 40553384

This study explores the biosynthesis of iron oxide nanoparticles (IONPs) by Aspergillus flavus recovered from The Iron and Steel Factory (Helwan) in EGYPT. Various factors, including metal salt concentration, inoculum size, pH, incubation time, temperature, and aeration, were optimized to enhance nanoparticle production. Characterization of the IONPs was performed using UV–Vis spectroscopy, Dynamic light scattering (DLS), X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FTIR). The synthesized IONPs were found to be quasi-spherical with sizes ranging from 7.66 to 49 nm and exhibited an amorphous structure. The photocatalytic activity of the IONPs was evaluated for the degradation of Coomassie Brilliant Blue R-250 under UV light. At pH 3 and with 10 mg/mL IONPs, 61% degradation of 7 ppm dye was achieved after 180 min. The antimicrobial activity of the IONPs was assessed against 8 microbial strains (Aspergillus flavus MT102937, Aspergillus niger MT103092, Aspergillus fumigatus MT103062, Candida albicans CA10231, Escherichia coli ATCC 25922, Shigella sonnei ATCC 29930, Staphylococcus aureus ATCC 6538, and Streptococcus mutans ATCC 25175). The IONPs showed the highest inhibitory effect against Staphylococcus aureus ATCC 6538, with a zone of inhibition of 22.33 ± 0.58 mm, while Aspergillus niger MT103092 was the most sensitive fungal species, showing an inhibition zone of 16.33 ± 1.53 mm. The results highlighting the potential applications of biosynthesized IONPs in environmental remediation and antimicrobial therapies.

Wang, Xu-Dong; Bai, Jia-Li; Ma, Zhen-Jia; Fan, Jie; Kong, Wei-Bao; Wang, Jun-Long; Zhang, Ji; Liang, Jun-Yu

doi: 10.1007/s00284-025-04333-8pmid: 40603548

In light of concerns regarding milk quality deterioration and the rising threat of bacterial resistance, developing alternative treatments to antibiotics for mastitis has become imperative. Clove oil (CEO), a well-established natural antimicrobial, has not been extensively investigated for its synergistic potential when combined with Elsholtzia EO. Essential oils (EOs) from the plants were extracted using steam distillation. Gas chromatography–mass spectrometry (GC–MS) results showed that the main component of CEO was eugenol (76.59%), the main component of Elsholtzia densa EO was limonene (22.05%), the main component of Elsholtzia ciliata EO was carvone (31.63%), the main component of Elsholtzia fruticosa EO (EfEO) was eucalyptol (40.1%), and the main component of Elsholtzia stauntonii EO was cuminol (27.60%). Antimicrobial assays demonstrated CEO′s superior efficacy against bovine mastitis pathogens (MIC: 1.875–7.5 mg/mL), while CEO/EfEO combination exhibited marked synergy (FICI ≤ 0.75). Further studies on the antimicrobial mechanisms of CEO, EfEO, and the CEO/EfEO combination showed that they were able to affect the integrity of the bacterial cell wall and increase membrane permeability. Such effect led to the leakage of biomolecules, including proteins and nucleic acids, accompanied by a concurrent decline in intracellular ATPase activity. The results of antioxidant activity assay showed that CEO exhibited stronger antioxidant capacity than EfEO. Cytotoxicity assessments conducted in bovine mammary epithelial cells delineated safe therapeutic windows, with EC50 values ranging from 0.120 to 0.148 mg/mL for CEO and 0.261–0.286 mg/mL for EfEO. Furthermore, the combined application of CEO and EfEO resulted in a reduction of the EC50 value. These findings indicate that CEO and EfEO represent a promising phytotherapeutic alternative, offering a potential solution to the growing challenge of antibiotic resistance in dairy production systems.

Mosaad, Habiba; Elekhnawy, Engy; Negm, Walaa A.; Younis, Salwa S.; El-Aasr, Mona

doi: 10.1007/s00284-025-04316-9pmid: 40528121

In light of the propagation of resistance amongst bacteria, many infections are currently difficult to treat, with extremely high death and morbidity rates. Thus, we investigated the effect of using a combination of amoxicillin and broccoli ethanolic extract against Staphylococcus aureus infections. Broccoli or Brassica oleracea active metabolites’ were to be identified and quantified using high-performance liquid chromatography (HPLC). The major detected compounds were chlorogenic acid and gallic acid. In vitro, the combination of amoxicillin with broccoli revealed fractional inhibitory concentration index of the amoxicillin-broccoli combination was less than 0.5 in 50% of the isolates, which indicates a synergetic potential. The in vivo study revealed a notable lessening in the bacterial count present in the examined tissues in the employed systemic infection model. The studied tissues were kidney, liver, and spleen. Moreover, the histological characteristics were found to have a remarkable enhancement in the combination-treated group. Thus, future clinical reports have to be employed to explicate the usefulness of such a combination in the clinical practice.Graphical abstract[graphic not available: see fulltext]