The cecal microbial community plays an important role in chicken growth and development via effective feed conversion and essential metabolite production. The aim of this study was to define the microbial community’s variants in chickens’ ceca and to explore the most significant association between the microbiome compositions and poultry farming productivity. The meta-analysis included original data from 8 control broiler chicken groups fed with a standard basic diet and 32 experimental groups supplemented with various feed additives. Standard Illumina 16S-RNA gene sequencing technology was used to characterize the chicken cecal microbiome. Zootechnical data sets integrated with the European Production Effectiveness Factor (EPEF) were collected. Analysis of the bacterial taxa abundance and co-occurrence in chicken cecal microbiomes revealed two alternative patterns: Bacteroidota-dominated with decreased alpha biodiversity; and Bacillota-enriched, which included the Actinomycetota, Cyanobacteriota and Thermodesulfobacteriota phyla members, with increased biodiversity indices. Bacillota-enriched microbiome groups showed elevated total feed intake (especially due to the starter feed intake) and final body weight, and high EPEF values, while Bacteroidota-dominated microbiomes were negatively associated with poultry farming productivity. The meta-analysis results lay the basis for the development of chicken growth-promoting feed supplementations, aimed at the stimulation of beneficial and inhibition of harmful bacterial patterns, where relevant metagenomic data can be a tool for their control and selection.

Chromobacterium spp. use a density-dependent cell-to-cell communication mechanism (quorum sensing, QS) to control various traits, including the pigment violacein biosynthesis. Recently, one of the type strains of this genus, previously deposited in the American Type Culture Collection under accession number C. violaceum 31532, was reclassified as C. subtsugae, making the QS data obtained for the first species irrelevant to the second. The goal of this study is to conduct transcriptomic and genomic analyses of the C. subtsugae ATCC 31532 (formerly C. violaceum ATCC 31532) strain to identify density-dependent regulated genes and the mechanisms of their QS control. Whole transcriptome dataset analysis comparing QS-negative mid-log phase and QS-positive early stationary phase samples revealed 35 down-regulated and 261 up-regulated genes, including 44 genes that increased transcription activity the most (log2 (fold change) > 4.0). In addition to the violacein biosynthesis, QS-controlled traits in C. subtsugae ATCC 31532 included the following: (i) cdeAB-oprM efflux pump; (ii) RND efflux transporter; (iii) chuPRSTUV iron acquisition system; (iv) polyamine transport system; (v) carbohydrate (semialdehydes) metabolic pathways; (vi) SAM/SPASM maturase system XYE (predicted); (vii) prophage proteins; and (viii) fucose-binding lectin II. Subsequent screening of the promoter regions of the up-regulated genes and operons in most cases showed the presence of CsuR AHL-receptor/transcriptional regulator binding sites with 56.25–68.75% similarity to the ideal 16-base-pair palindrome 5′-CTGTCCGATAGGACAG-3′ sequence, supporting the concept of QS control in C. subtsugae ATCC 31532 by the csuI-csuR gene pair. Notably, several transcriptional regulators (MarR, TetR/AcrR, HU family DNA-binding protein, helix-turn-helix domain-containing protein) were found to be under QS control. Based on these data, a hierarchical QS regulatory network in C. subtsugae ATCC 31532 was hypothesized that provides direct control of the target genes via a canonical autoinduction mechanism and further dissemination of the effect via the activity of QS-controlled transcriptional regulators.

The paper reports on a study of the effects of different type antioxidant molecules on recombinant, luminescent, bacterial biosensensors. It has been demonstrated that thiamine can activate...

The current study presents a meta-analysis of the detailed relationship between the composition of 25 essential and toxic elements in chicken tissues examined by ICP-MS and the gut microbial community analyzed using NGS techniques. The examination of chicken liver and meat revealed typical elemental compositions, called the “elementomes”. The α-elementomes showed high contents of macro elements (Na, K, Mg, Ca, P), majority trace elements (Sr, Se, Mn, Fe, Co, Cu, Zn) and some toxic elements (B, Pb, Ni, Cd); β-elementomes indicated accumulation of Si, V and Cr; γ-elementomes indicated accumulation of Al, As and Hg. Characterization of the microbiomes’ structure showed two distinct enterotypes, designated “microbiome patterns”; the first was enriched in the phylum Bacteroidota, and the second was dominated by Bacillota and coupled with members of the phyla Actinomycetota, Cyanobacteriota and Thermodesulfobacteriota. A comparison of elementomes and microbiomes demonstrated a clear correspondence between the α- and γ-elementomes belonging to the Bacteroidota-enriched pattern, while the β-elementome was predominantly found in chicken groups belonging to the Bacillota + ACT pattern. This insight proposes a novel strategy to improve deficiency or excess of certain elements in the host by gut microbiome modulation, which needs to be verified with further in vivo experiments.

The study, designed as a group-level integrative data analysis, included homogeneous datasets obtained from 24 Arbor Acres chicken groups. Quantitative amino-acid analysis in chicken tissues was carried out using the capillary electrophoresis method. Gut microbial community analysis was performed using 16S rRNA gene-sequencing technology on the Illumina MiSeq platform. Amino-acid analysis of liver samples revealed 10 Arg-high and 14 Arg-low chicken groups, while for thigh samples, the ratio of Arg-high and Arg-low groups was 18/6, respectively. The gut microbiomes of chickens with an Arg-high amino-acid profile showed increased Chao1 and Shannon diversity index values, defined by a significant abundance of several members of the phylum Bacillota (formerly Firmicutes), including the genera Christensenella, Eisenbergiella, Dysosmobacter, Anaerotignum, Oscillibacter, unclassified Oscillospiraceae, and Lachnospiraceae. In contrast, the gut microbial communities of chickens with low Arg content showed decreased Chao1 and an increased Shannon dominance index, which was explained by the significant abundance of the genus Alistipes belonging to the phylum Bacteroidota (formerly Bacteroidetes). Prediction of amino-acid biosynthetic pathways in chicken-gut microbiomes revealed a general trend toward increased relative abundance of most KEGG orthologs in Arg-high groups, as well as a number of positive links with Arg and Val/Leu + Ile content in liver and thigh samples.

Introduction. In most cases, osteomyelitis is the monomicrobial disease caused by various Gram-positive bacteria. However, previous injury may contribute to formation of a microbial association. Presence of two or more pathogens in the infectious focus can markedly complicate the disease clinical picture.Kytococcus schroeteriis one of the rarest pathogens found in clinical samples. Slightly more than twenty described cases related to such infection have been recorded globally. The aim of the research was to analyse the first identified clinical case of post-traumatic osteomyelitis associated withKytococcus schroeteriandEnterococcus faecalis.Materials and methods.The bacterial cultures were obtained from the wound discharge of the patient’s shin by the cultural method. Identification of the bacterial cultures was performed using a VITEK MS mass spectrometer followed by 16S rRNA gene sequencing. The morphological, tinctorial and biochemical features of the cultures obtained were established, and their antibacterial resistance was also determined.Results. The clinical case was associated with the diagnosis “Chronic post-traumatic osteomyelitis of the left shin”. Two types of microorganisms were isolated from the wound discharge, and identified asKytococcus schroeteriandEnterococcus faecalisusing the MALDI-ToF mass spectrometry method. 16S rRNA gene sequencing from the isolated bacterial cultures confirmed the MALDI-ToF mass spectrometry data. Antimicrobial susceptibility for this microorganism was determined according to the criteria for the staphylococcal group according to the clinical guide “Determination of sensitivity to antimicrobial drugs (rev. 2021)”.Conclusion. For the first time, the mixed infection caused by two Gram-positive bacteriaK. schroeteriandE. faecalishas been described. Such associations can enhance the pathogenic effects of each other bacterium, which may contribute to transition of the infection to a chronic form with a low probability of positive cultural test.K. schroeteriis a representative of the normal skin microbiota, but this microorganism is able to cause various infections. TheK. schroeterispecies should be differentiated from other representatives of the orderMicrococcales. At cultural examination, resistance to oxacillin is a suspicious sign indicating that the bacterial culture might be potentially assigned toK. schroeterispecies. Due to the unavailability of current biochemical tests for differentiationK. schroeterifrom related taxa, reliable identification of this species is recommended using MALDI-ToF mass spectrometry or 16S rRNA gene sequencing.