Cellular Microbiology最新文献

Helicobacter pylori (H. pylori) is one of the major causes of gastric mucosal damage, and infection with H. pylori induces an immune response with gastric mucosal cells, which reduces gastric mucosal damage. The pseudogene BNIP3P1, sharing a remarkable 95.92% similarity with its well-characterized counterpart BNIP3, has largely remained unexplored. To elucidate the role of BNIP3P1 in gastric mucosal damage induced by H. pylori infection, we meticulously constructed both in vivo and in vitro models. Gene chip sequencing, dual-luciferase assays, and cellular phenotyping were detected. We uncovered a compelling positive correlation between the duration of H. pylori infection and BNIP3 overexpression at both the mRNA and protein levels. Intriguingly, overexpression of BNIP3 was found to effectively impede the proliferation and migration of human gastric epithelial cells (GES-1). Furthermore, we identified miR-411-5p as a direct regulator of BNIP3, targeting its 3 ^′UTR region and suppressing its expression during H. pylori infection. Notably, BNIP3P1- 3^′UTR was observed to competitively bind miR-411-5p, leading to the upregulation of BNIP3 expression. Furthermore, overexpression of BNIP3P1 was associated with a marked decrease in GES-1 cell proliferation and a concomitant acceleration of apoptosis. Our findings suggest that BNIP3P1 functions as a competing endogenous RNA (ceRNA) within the BNIP3/miR-411-5p axis during H. pylori infection, which ultimately hinders cell proliferation and promotes apoptosis in GES-1 cells. This study sheds light on the intricate mechanisms underlying H. pylori infection of GES-1 cells.

Bacillales is an order of Gram-positive bacteria comprising well-known genera such as Staphylococcus, Listeria, and Bacillus. Staphylococcus aureus has been shown to cause various types of tissue and systemic infections in humans and livestock. Some isolates can be highly resistant to antibiotics hence the need to identify better drugs and drug targets. Previous studies have shown that (E)-N-(4-fluorophenyl)-2-phenylethene sulfonamide (FPSS) could inhibit activities of a bacteria-specific transcription factor sigma B. Sigma B regulons in Bacillus subtilis and in Listeria monocytogenes, including virulence factor genes in L. monocytogenes, were decreased. Since sigma B is also presented in S. aureus, we initially postulated the use of FPSS to target S. aureus sigma B activity and to attenuate its virulence gene expression. Surprisingly, qRT-PCR results revealed that FPSS induced the expression of sigma B-dependent gene asp23. RNAseq results showed 39 S. aureus genes were affected by FPSS (37 genes were upregulated and two genes were downregulated). FPSS had no effect on expression of sigB operon in S. aureus. Therefore, we hypothesized that the effects of FPSS on sigma B regulons in L. monocytogenes, B. subtilis, and S. aureus were different. FPSS may target the expression of upstream regulators of sigma B (Rsbs), particularly the stressosome proteins which are lacking in S. aureus. Indeed, in L. monocytogenes, FPSS significantly increased the rsbR expression and could, thereby, dampen the sigma B activity and downregulate the expression of sigma B-dependent virulence genes in L. monocytogenes. This study proposes a narrower spectrum of FPSS application to listerial infections, and not staphylococcal infections.

To investigate the investigation of gut microbial communities to chicken egg production performance during different laying stages, we conducted a comparative study of the diversity, composition, and function of microbial communities in the fecal and cecal contents of six hens at the early stage, 25 at the peak stage, and 15 at the late stage. We obtained clean data averaging 13.40 and 13.79 Gb for each of the fecal and cecal content samples. The metagenomic analysis revealed significant differences in fecal and cecal content microbial diversity during different laying stages, especially during the peak stage, and the microbiota structure of fecal contents was more stable compared to that of cecal contents. The dominant microflora in the fecal contents during the peak stage were Firmicutes (74.84%) and Lactobacillus (28.13%). The dominant microflora of cecal contents during different stages were basically the same at the phylum level and genus level. During the peak stage, the dominant bacteria shared by microorganisms in the fecal and cecal contents were Lactobacillus. Functional analyses of the gut microbiome indicate that fecal and cecal content microbes have different functional capacities at different egg-laying stages. We therefore hypothesized that the gut microbiome would vary with laying stage and have a non-negligible effect on egg production performance. These results improved our ability to provide some theoretical basis for feeding management of laying hens during different laying stages and provided insights into the influence of the gut microbiota on the laying performance of chickens.

Trachelomonas hispida var. coronata is one of the most widely reported varieties of T. hispida from water bodies worldwide. The specimens of this variety, apart from their species-specific features, such as an ellipsoidal lorica covered with strong, sharp spines, have a crown consisting of long spines surrounding the apical pore opening. The process of lorica formation is poorly understood, and in the few studies dealing with this topic, results indicate that these taxa and the entire species can produce lorica completely devoid of spines, a diacritic feature of the species. In our study, we observed in detail the formation process of the lorica in this taxon under different chemical conditions in relation to the concentration of the basic elements, Fe and Mn, which are saturated in trachelomonad lorica. The results showed that in the Fe-enriched medium, monads formed delicate, porous, spiny envelopes, whereas in the Mn-enriched medium, the loricae were more solid and less porous and had weaker developed spines; rather, they were in the form of short papillae. Differences were also observed in the structure surrounding the apical pore, which was developed differently in the two sets of media modifications (Fe- or Mn-supplemented media). We also observed different elemental compositions and colouration of loricae of cells growing in different media. This revealed that the features considered during the process of species identification are very unstable making the entire exercise highly complicated. Our research also shows that a broad discussion of the problem should be undertaken, and modern methods must be developed to unravel the complexities not only within the species but also within the entire Trachelomonas.

The prevalence of low back pain (LBP) due to lumbar disc herniation (LDH) was recorded as 31.9% in the year 2022. Studies carried out around the world have failed to confirm the primary cause of disc herniation. Among the multiple hypothesized contributing factors, a low-grade bacterial infection has been identified as one of the major causes of LDH. Researchers have reported that Propionibacterium acnes (P. acnes) is the predominant bacterial species isolated using culture-derived methods. However, biofilm formation leads to a low bacterial yield in culture methods. Although culture methods remain the gold standard for the identification of bacterial species, there is a growing need for the usage of advanced techniques that are more sensitive, reliable, less time-consuming, and precise. Advancement of high-throughput sequencing tools allows thorough mining of complete bacterial profiles, even for bacteria that are challenging to cultivate in conventional laboratory settings. Currently, both high-throughput sequencing and omics have opened a new avenue, providing clear evidence for addressing queries related to bacterial contamination that have been frequently addressed in culture isolates of herniated discs over the past few decades. This review evaluates how advanced techniques in microbial identification have revolutionized our understanding of bacteria in disc health. Traditional methods confirmed the existence of known bacteria, but advanced techniques revealed a vast, previously unseen diversity, challenging the output of culture-based methods. This new information has even overturned the understanding of the role of P. acnes in evaluating disc health. Advanced techniques have opened a window to the hidden world of microbes and have been attributed to altered views on bacterial communities in healthy and herniated discs.

Proteases degrade proteins and peptides, recycling materials and preventing unnecessary buildup within the cell. They can also be secreted and act in extracellular space. Bacterial proteases are often secreted and function as virulence factors. In the context of the microbiome, they can contribute to host–microbe interactions to facilitate colonization and disease pathogenesis. Thus, proteolytic activity is often found to be upregulated in patient cohorts. In this minireview, we describe how bacterial proteases in the microbiome can display various bioactivities such as disruption of barrier function, degradation of host defense compounds, modulating inflammatory responses, and allowing for microbial movement. We focus on the gut, skin, vaginal, and urinary microbiomes and describe how specific bacterial organisms have proteolytic activities that can exacerbate or lead to human diseases.

Apilactobacillus kosoi (A. kosoi) 10H is a fructophilic lactic acid bacterium found in vegetable sugar fermentation liquid. It has been shown to possess high intestinal immunostimulatory activity. In this study, we investigated the potential for A. kosoi 10H heat-killed cells and their components to convert the phenotype of immunosuppressive M2 macrophages to immunostimulatory M1 macrophages. We further investigated the ability of induction of apoptosis of cancer cell lines by macrophage culture medium in the presence of A. kosoi 10H heat-killed cells. After induction of macrophage differentiation by phorbol 12-myristate 13-acetate in a THP-1 human monocyte–derived cell line, immunosuppressive M2 macrophages were induced by interleukin-6 (IL-6). When A. kosoi 10H heat-killed cells were brought into contact with IL-6-induced M2 macrophages, the expression of CD163 and CD209, which are M2 macrophage markers, markedly decreased, and the expression of CD80, human leukocyte antigen-DR isotype (HLA-DR), and tumor necrosis factor-α (TNF-α), markers of M1 macrophages, markedly increased. A similar effect was observed with a water-soluble extract and a hydrophobic liquid extract from A. kosoi 10H heat-killed cells. In addition, when M2 macrophage culture medium that had been conditioned with A. kosoi 10H heat-killed cells was added to the MCF-7 breast cancer cell line, we found that apoptosis was induced. TNF-α in the medium conditioned with macrophages cultured in the presence of A. kosoi 10H heat-killed cells was found to be partially responsible for MCF-7 cell death. This study presents basic data on the potential to use lactic acid bacteria to improve the cancer microenvironment.

Infertility is a condition where a male or female is unable to achieve pregnancy through at least 1 year of regular, unprotected sexual intercourse. There are several known causes and risk factors associated with infertility. The gut microbiota is a complex community of trillions of microorganisms living in the gut. Due to modern lifestyle changes, such as dietary habits, physical inactivity, and increasing antibiotic use, the diversity and composition of these microbes may change in a detrimental manner. Dysbiosis or an imbalance of the gut microbiota compared to a normal composition can lead to various abnormalities, such as obesity, Alzheimer’s, metabolic disorders, and infertility. This review will cover the factors influencing gut microbiota composition, the mechanisms by which gut microbiota contributes to infertility in men and women, the effects of gut microbiota on problems that may arise during pregnancy, and therapeutic methods for diseases caused by dysbiosis of the gut microbiota.

Multidrug-resistant (MDR) pathogens such as Escherichia coli, Pseudomonas aeruginosa, and Enterobacter cloacae have become a global health threat. Drug repositioning or repurposing has become a viable solution to combat the threat posed by MDR pathogens. A strategic approach to identifying potential new candidates as future molecular drug targets is presented in this study. Fifty proteins critical for virulence during systemic infection were selected from the entire genomes of MDR E. coli MB641 and Enterobacter cloacae MB649, which were isolated from infected orthopaedic implants. Interaction networks were built using the STRING database to visualise the positioning of the selected virulence proteins in the network space and support their suitability for therapeutic targeting. The two significant virulence proteins FliG and FlhA, which were discovered by network analysis, were suggested as prospective treatment targets. To test the stability of the protein–drug complexes, the preidentified proteins were docked with 10 marketed antibacterial drugs and six phytochemicals. Amikacin, rifampicin, streptomycin, and tetracycline had the best binding interaction and stability for both strains, according to our findings. Molecular dynamic simulation studies were performed for amikacin and catechin at 100 ns. Both hydrophobic and hydrophilic stable contacts were seen in the active sites of amikacin and catechin with new chemical structures. Structural and conformational analysis of the docked protein-ligand complex was done by RMSD which showed stability of the amikacin and catechin complexes, whereas RMSF showed conformational changes. Based on the results, we propose the phytochemical catechin as the best theoretical lead, which may be further experimentally studied for selective inhibition.

Klebsiella species are becoming a major global public health concern. In particular, the increase in multidrug-resistant strains is a cause for concern. This study was aimed at determining the antibiotic susceptibility of two different isolates of Klebsiella quasipneumoniae subsp. similipneumoniae and determining the virulence characteristics and bacterial morphology under subminimum inhibitory concentrations (sub-MICs) of antibiotics. In this study, two multidrug-resistant K. quasipneumoniae subsp. similipneumoniae isolates were identified, one of which was clinical, and the other was isolated from freshwater. The MICs of the antibiotics meropenem, chloramphenicol, ciprofloxacin, and kanamycin were determined for these isolates. The effects of the sub-MICs on the virulence and morphological characteristics of the bacteria were investigated in comparison with K. pneumoniae (ATCC 13883). The MICs of meropenem, chloramphenicol, ciprofloxacin, and kanamycin were 0.04, 20, 2, and 8 μg/mL in the clinical isolate; 0.2, 15, 5, and 2 μg/mL in the freshwater isolate; and 0.03, 3, 0.1, and 0.3 μg/mL for K. pneumoniae. The biofilm-forming ability of K. quasipneumoniae subsp. similipneumoniae isolates decreased with antibiotic sub-MICs. Siderophore activity increased only with MIC/4 of kanamycin and MIC/2 of chloramphenicol in the clinical isolate (p > 0.05). Furthermore, bacterial morphology and expression of virulence genes were affected differently by the sub-MICs. This study showed that biofilm formation decreased and that the changes in bacterial morphology and expression of virulence genes were very different in the presence of 1/2 and 1/4 sub-MIC antibiotics.