The multicopper oxidase of Mycobacterium tuberculosis (MmcO) exhibits ferroxidase activity and scavenges reactive oxygen species in activated THP-1 cells

Serum Ceruloplasmin-to-Albumin Ratio as a Biochemical Marker in Pulmonary Tuberculosis Before and After Treatment

BACKGROUND

The study compares the serum ceruloplasmin-to-albumin ratio of tuberculosis (TB) patients before and after anti-tuberculosis treatment (ATT) to assess its diagnostic and prognostic value. Despite the pandemic's impact on TB notifications, global TB cases rose by 16% in 2022.

METHODS

The study was conducted at Meenakshi Medical College Hospital and Research Institute, Kanchipuram, from November 2022 to November 2023, with participants aged 15 and above diagnosed with pulmonary TB. The analysis of clinical, radiographic, microbiological, and biochemical data revealed a gender distribution of 58% male and 42% female individuals, with an average age of 49. Significant reductions in ceruloplasmin levels and increases in albumin levels were found following therapy, as well as a decrease in the ceruloplasmin-to-albumin ratio, showing that ceruloplasmin may serve as a severity measure and treatment indicator.

RESULTS

Male patients accounted for 58% of the study population, while females accounted for 42%. Patients aged 36-45 made up the largest group (26%). Following treatment, serum ceruloplasmin levels decreased significantly (from 66.28 mg/dL to 35.56 mg/dL), but albumin levels increased (from 2.96 g/dL to 4.19 g/dL). The ceruloplasmin-to-albumin ratio dropped from 0.022 to 0.008, showing treatment efficacy.

CONCLUSIONS

The study highlights the potential of serum biomarkers for diagnosing and monitoring TB. The serum ceruloplasmin-to-albumin ratio is a promising biochemical diagnostic. Further research is needed to validate these findings and investigate their clinical significance in TB management.

Insertion sequence contributes to the evolution and environmental adaptation of Acidithiobacillus

BACKGROUND

The genus Acidithiobacillus has been widely concerned due to its superior survival and oxidation ability in acid mine drainage (AMD). However, the contribution of insertion sequence (IS) to their biological evolution and environmental adaptation is very limited. ISs are the simplest kinds of mobile genetic elements (MGEs), capable of interrupting genes, operons, or regulating the expression of genes through transposition activity. ISs could be classified into different families with their own members, possessing different copies.

RESULTS

In this study, the distribution and evolution of ISs, as well as the functions of the genes around ISs in 36 Acidithiobacillus genomes, were analyzed. The results showed that 248 members belonging to 23 IS families with a total of 10,652 copies were identified within the target genomes. The IS families and copy numbers among each species were significantly different, indicating that the IS distribution of Acidithiobacillus were not even. A. ferrooxidans had 166 IS members, which may develop more gene transposition strategies compared with other Acidithiobacillus spp. What's more, A. thiooxidans harbored the most IS copies, suggesting that their ISs were the most active and more likely to transpose. The ISs clustered in the phylogenetic tree approximately according to the family, which were mostly different from the evolutionary trends of their host genomes. Thus, it was suggested that the recent activity of ISs of Acidithiobacillus was not only determined by their genetic characteristics, but related with the environmental pressure. In addition, many ISs especially Tn3 and IS110 families were inserted around the regions whose functions were As/Hg/Cu/Co/Zn/Cd translocation and sulfur oxidation, implying that ISs could improve the adaptive capacities of Acidithiobacillus to the extremely acidic environment by enhancing their resistance to heavy metals and utilization of sulfur.

CONCLUSIONS

This study provided the genomic evidence for the contribution of IS to evolution and adaptation of Acidithiobacillus, opening novel sights into the genome plasticity of those acidophiles.

Metal manipulators and regulators in human pathogens: A comprehensive review on microbial redox copper metalloenzymes "multicopper oxidases and superoxide dismutases"

The chemistry of metal ions with human pathogens is essential for their survival, energy generation, redox signaling, and niche dominance. To regulate and manipulate the metal ions, various enzymes and metal chelators are present in pathogenic bacteria. Metalloenzymes incorporate transition metal such as iron, zinc, cobalt, and copper in their reaction centers to perform essential metabolic functions; however, iron and copper have gained more importance. Multicopper oxidases have the ability to perform redox reaction on phenolic substrates with the help of copper ions. They have been reported from Enterobacteriaceae, namely Salmonella enterica, Escherichia coli, and Yersinia enterocolitica, but their role in virulence is still poorly understood. Similarly, superoxide dismutases participate in reducing oxidative stress and allow the survival of pathogens. Their role in virulence and survival is well established in Salmonella typhimurium and Mycobacterium tuberculosis. Further, to ensure survival against stress, like metal starvation or metal toxicity, redox metalloenzymes and metal transportation systems of pathogens actively participate in metal homeostasis. Recently, the omics and protein structure biology studies have helped to predict new targets for regulation the colonization potential of the pathogenic strains. The current review is focused on the major roles of redox metalloenzymes, especially MCOs and SODs of human pathogenic bacteria.

Sedimentimonas flavescens gen. nov., sp. nov., isolated from sediment of Clam Island, Liaoning Province

A novel Gram-stain negative, aerobic and ovoid to short rod shaped bacterium with a single polar flagellum, named strain B57^T, was isolated from sediment of Clam Island, Liaoning Province, China. The optimal growth of this strain was found to occur at 37 °C, pH 6-6.5, and in the presence of 2% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain B57^T forms a distinct lineage within the family Rhodobacteraceae, sharing high 16S rRNA gene sequence similarity with Sinirhodobacter populi sk2b1^T (97.4%). The average amino acid identity of B57^T and the closely related species were lower than the threshold level for genus delineation. The dominant respiratory quinone of strain B57^T was identified as Q-10. The major fatty acids were found to be Summed Feature 8 (C_18:1ω7c and/or C_18:1ω6c), Summed Feature 3 (C_16:1ω7c and/or C_16:1ω6c) and C_16: 0. The polar lipids were identified as phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, diphosphatidylglycerol, two unidentified phospholipids, one unidentified glycolipid, and one unidentified lipid. The DNA G + C content of strain B57^T was determined to be 64.1 mol%. Based on the biochemical, phylogenetic and chemotaxonomic analysis, strain B57^T is concluded to represent a novel species of a novel genus, for which the name Sedimentimonas flavescens gen. nov., sp. nov.is proposed. The type strain is B57^T (= CGMCC1.19488^T = KCTC 92053^T).