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Journal of Investigative Medicine High... 2015Introduction. In December 2014, the Food and Drug Administration issued a recall of all Wallcur simulation products due to reports of their use in clinical practice. We...
Introduction. In December 2014, the Food and Drug Administration issued a recall of all Wallcur simulation products due to reports of their use in clinical practice. We present a case of septic shock and multiorgan failure after the accidental intravenous infusion of a nonsterile Wallcur simulation product. Case. The patient presented with symptoms of rigors and dyspnea occurring immediately after infusion of Wallcur Practi-0.9% saline. Initial laboratory evidence was consistent with severe septic shock and multiorgan dysfunction. His initial lactic acid level was 9 mmol/L (reference range = 0.5-2.2), and he had evidence of acute kidney injury and markers of disseminated intravascular coagulation. All 4 blood culture bottles isolated multidrug-resistant Empedobacter brevis. The patient recovered from his illness and was discharged with ciprofloxacin therapy per susceptibilities. Discussion. This patient represents the first described case of severe septic shock associated with the infusion of a Wallcur simulation product. Intravenous inoculation of a nonsterile fluid is rare and exposes the patient to unusual environmental organisms, toxins, or unsafe fluid characteristics such as tonicity. During course of treatment, we identified the possible culprit to be a multidrug-resistant isolate of Empedobacter brevis. We also discuss the systemic failures that led to this outbreak.
PubMed: 26668812
DOI: 10.1177/2324709615618980 -
PeerJ 2022Mulberry flavonoids can modulate the composition of rumen microbiota in ruminants to improve nutrient digestibility, owing to their strong biological activities. This...
Mulberry flavonoids can modulate the composition of rumen microbiota in ruminants to improve nutrient digestibility, owing to their strong biological activities. This study aimed to explore the effect of mulberry leaf flavonoids (MLF) on rumen bacteria, fermentation kinetics, and metagenomic functional profile in water buffalo. Forty buffaloes (4 ± 1 lactations) with almost same body weight (av. 600 ± 50 Kg) and days in milk (90 ± 20 d) were randomly allocated to four treatments having different levels of MLF: 0 g/d (control), 15 g/d (MLF15), 30 g/d (MLF30), and 45 g/d (MLF45) supplemented in a basal diet. After 35 days of supplementation, rumen contents were collected to determine rumen fermentation parameters. The 16S rRNA gene sequencing was performed to elucidate rumen bacteria composition. The obtained taxonomic data were analyzed to explore the rumen bacteriome and predict the associated gene functions and metabolic pathways. Results demonstrated a linear increase ( < 0.01) in rumen acetate, propionate, and total VFAs in the MLF45 group as compared to control. No effect of treatment was observed on rumen pH and butyrate contents. Acetate to propionate ratio in the MLF45 group linearly and quadratically decreased ( = 0.001) as compared to MLF15 and control groups. Similarly, MLF45 linearly increased ( < 0.05) the microbial protein (MCP) and NH-N as compared to other treatments. Treatment adversely affected ( < 0.01) almost all alpha diversity parameters of rumen bacteria except Simpson index. MLF promoted the abundance of Proteobacteria while reducing the relative abundances of Actinobacteria, Acidobacteria, Chloroflexi, and Patescibacteria. The MLF supplementation tended to substantially reduce (0.05 < < 0.1) the abundance of Actinobacteria, and Patescibacteria while completely eliminating Acidobacteria ( = 0.029, Chloroflexi = 0.059, and Gemmatimonadetes ( = 0.03) indicating the negative effect of flavonoids on the growth of these bacteria. However, MLF45 tended to substantially increase ( = 0.07) the abundance (~21.5%) of . The MLF treatment exhibited negative effect on five genera by significantly reducing (Sphingomonas) or eliminating (Arthobactor, unclassified_c__Actinobacteria, norank_c__Subgroup_6, norank_o__Saccharimonadales, and Nocardioides) them from the rumen microbiota. Pearson correlation analysis revealed 3, 5 and 23 positive correlations of rumen bacteria with milk yield, rumen fermentation and serum antioxidant parameters, respectively. A positive correlation of MCP was observed with three bacterial genera (Acetobacter, Enterobacter, and Klebsiella). The relative abundance of Pseudobutyrivibrio and Empedobacter also showed a positive correlation with the ruminal acetate and propionate. The present study indicated 45 g/d as an appropriate dose of MLF which modulated rumen bacteria and its functional profile in water buffalo.
Topics: Animals; Female; Acetates; Bacteria; Buffaloes; Fermentation; Morus; Propionates; RNA, Ribosomal, 16S; Rumen
PubMed: 36536626
DOI: 10.7717/peerj.14309 -
Infection, Genetics and Evolution :... Mar 2022Empedobacter falsenii is an emerging opportunistic pathogen that has been occasionally implicated in various human infections. In this study, we described the genomic...
Empedobacter falsenii is an emerging opportunistic pathogen that has been occasionally implicated in various human infections. In this study, we described the genomic features of a multidrug resistant E. falsenii Q1655 obtained from a patient attending a public hospital in Sokoto, northwest Nigeria. The isolate, E. falsenii Q1655, was isolated from the stool sample of a patient in Sokoto, Nigeria. The identity of the isolate was confirmed by MALDITOF-MS. The disc diffusion test and modified Carba-NP test were used for phenotypic antibiotic susceptibility test and carbapenemase enzyme production test, respectively. The whole genome of the strain was sequenced using the Illumina MiSeq technique. Resistome analysis was done by annotation of the WGS against the ARG-ANNOT database. The isolate was resistant to all β-lactam antibiotics with the exception of cefepime. The MICs of imipenem and ertapenem as determined by E-test were 12 μg/ml and 2 μg/ml, respectively. Modified Carba NP test showed that the strain was carbapenemase producing. Resistome analysis revealed the presence of a novel metallo-β-lactamase, a chromosomal bla, which exhibited 94.92% and 97.02% nucleotide and protein sequence identities respectively with bla gene of E. falsenii 174,820. Seven and eight amino-acid substitutions were observed with the bla and bla, respectively. We reported the first isolation and genomic description of an extensively drug resistant isolate of Empedobacter falsenii in Nigeria. This report broadens our knowledge of carbapenem resistance in E. falsenii and it will serve as a useful guide in the development of antibiotic use policy.
Topics: Anti-Bacterial Agents; Ertapenem; Flavobacteriaceae; Genome, Bacterial; Imipenem; Microbial Sensitivity Tests; beta-Lactamases
PubMed: 35121093
DOI: 10.1016/j.meegid.2022.105234 -
Frontiers in Nutrition 2022Rapeseed cake is a by-product of rapeseed oil separation. The nutritional components of rapeseed cake mainly include a variety of carbohydrates, proteins, and minerals....
Rapeseed cake is a by-product of rapeseed oil separation. The nutritional components of rapeseed cake mainly include a variety of carbohydrates, proteins, and minerals. In order to improve the conversion rate of rapeseed cake, we studied the physicochemical properties, the structure of microbial communities, and the composition of metabolites in rapeseed cake after enzymatic fermentation. The results showed that the addition of enzymatic preparation increased microbial diversity. The relative abundance of , , , , , and in enzymatic fermentation was significantly higher than that in natural fermentation. Unlike natural fermentation, microbial diversity during enzymatic fermentation is specific, which improves the efficiency of fermentation. Otherwise, enzymatic fermentation promotes the conversion of macromolecular substances in rapeseed cake, which increases small metabolites, such as fatty acids, organic acids, amino acids and their derivatives. The metabolite enrichment pathway is mostly concentrated in sugar metabolism and fatty acid metabolism. In conclusion, after adding enzymatic preparation, enzymes and microorganisms jointly promote the transformation of macromolecules during the fermentation of rapeseed cake, which laid a good foundation for further utilization of rapeseed cake.
PubMed: 36185678
DOI: 10.3389/fnut.2022.989410 -
IDCases 2023, formerly known as Wautersiella falsenii, was first described in 2006. It is a non-motile, non-fermenting, gram-negative rod, which grows aerobically. A handful of case...
, formerly known as Wautersiella falsenii, was first described in 2006. It is a non-motile, non-fermenting, gram-negative rod, which grows aerobically. A handful of case reports have described its isolation from respiratory, urinary and abscess samples. Besides clinical specimens, it has also been isolated from metalworking fluids and aerosols, carpet surfaces and polluted soils. However, to our knowledge, this is the first case report that describes bacteremia from . We present a 56-year-old male with liver cirrhosis, congestive heart failure and substance abuse disorder, who was admitted in a community hospital in the Bronx, New York for bacteremia of the said organism. This bacterium may serve as a reservoir for resistance genes, such as ERB, tetX and aadS, posing dangers to immunocompromised or hospitalized patients, highlighting the need to study this organism further.
PubMed: 37645528
DOI: 10.1016/j.idcr.2023.e01814 -
Emerging Microbes & Infections Dec 2020Tigecycline is one of the last-resort antibiotics to treat severe infections. Recently, tigecycline resistance has sporadically emerged with an increasing trend, and...
Tigecycline is one of the last-resort antibiotics to treat severe infections. Recently, tigecycline resistance has sporadically emerged with an increasing trend, and Tet(X) family represents a new resistance mechanism of tigecycline. In this study, a novel chromosome-encoded tigecycline resistance gene, (X14), was identified in a tigecycline-resistant and colistin-resistant strain ES183 recovered from a pig fecal sample in China. Tet(X14) shows 67.14-96.39% sequence identity to the other variants [Tet(X) to Tet(X13)]. Overexpression of Tet(X14) in confers 16-fold increase in tigecycline MIC (from 0.125 to 2 mg/L), which is lower than that of Tet(X3), Tet(X4) and Tet(X6). Structural modelling predicted that Tet(X14) shared a high homology with the other 12 variants with RMSD value from 0.003 to 0.055, and Tet(X14) can interact with tetracyclines by a similar pattern as the other Tet(X)s. (X14) and two copies of (X2) were identified on a genome island with abnormal GC content carried by the chromosome of ES183, and no mobile genetic elements were found surrounding, suggesting that (X14) might be heterologously obtained by ES183 via recombination. Blasting in Genbank revealed that Tet(X14) was exclusively detected on the chromosome of , mainly encoded on antimicrobial resistance islands. and belong to the family , suggesting that the members of maybe the major reservoir of (X14). Our study reports a novel chromosome-encoded tigecycline resistance gene (X14). The expanded members of Tet(X) family warrants the potential large-scale dissemination and the necessity of continuous surveillance for (X)-mediated tigecycline resistance.
Topics: Animals; Anti-Bacterial Agents; China; Colistin; Drug Resistance, Multiple, Bacterial; Feces; Flavobacteriaceae; Genome, Bacterial; Microbial Sensitivity Tests; Swine; Swine Diseases; Tetracycline Resistance; Tigecycline
PubMed: 32731802
DOI: 10.1080/22221751.2020.1803769 -
Case Reports in Pediatrics 2016Empedobacter brevis is gram-negative bacilli that belongs to Flavobacteriaceae family. It was previously known with name of Flavobacterium breve. The reservoir of these...
Empedobacter brevis is gram-negative bacilli that belongs to Flavobacteriaceae family. It was previously known with name of Flavobacterium breve. The reservoir of these bacteria is soil, plants, water, food, hospital water sources, including incubators, sinks, faucets, tap water, hemodialysis systems, saline solutions, and other pharmaceutical solutions. We report a case of term female newborn, admitted with complaint of respiratory distress developing soon after birth and developed clinical features of sepsis at age of 92 hours of postnatal life. The sepsis screen was positive and blood culture and cerebrospinal fluid showed growth of Empedobacter brevis that was resistant to multiple antibiotics. The neonate was treated with appropriate antibiotics and was discharged successfully. The novelty of the case report is that this is the first case report of neonatal sepsis caused by Empedobacter brevis.
PubMed: 27648334
DOI: 10.1155/2016/7609602 -
Translational Animal Science Jan 2023We applied ruminal and plasma metabolomics and ruminal 16S rRNA gene sequencing to determine the metabolic pathways and ruminal bacterial taxa associated with divergent...
We applied ruminal and plasma metabolomics and ruminal 16S rRNA gene sequencing to determine the metabolic pathways and ruminal bacterial taxa associated with divergent residual body weight gain phenotype in crossbred beef steers. A group of 108 crossbred growing beef steers (average BW = 282.87 ± 30 kg) were fed a forage-based diet for a period of 56 d in a confinement dry lot equipped with GrowSafe intake nodes to determine their residual body weight gain (RADG) phenotype. After RADG identification, blood and rumen fluid samples were collected from beef steers with the highest RADG (most efficient; = 16; 0.76 kg/d) and lowest RADG (least efficient; = 16; -0.65 kg/d). Quantitative untargeted metabolome analysis of the plasma and rumen fluid samples were conducted using chemical isotope labelling/liquid chromatography-mass spectrometry. Differentially abundant metabolites in each of the plasma and rumen fluid samples between the two groups of beef steers were determined using a false discovery rate (FDR)-adjusted -values ≤ 0.05 and area under the curve (AUC) > 0.80. Rumen and plasma metabolic pathways that were differentially enriched or depleted ( ≤ 0.05) in beef steers with positive RADG compared to those with negative RADG were determined by the quantitative pathway enrichment analysis. A total of 1,629 metabolites were detected and identified in the plasma of the beef steers; eight metabolites including alanyl-phenylalanine, 8-hydroxyguanosine, and slaframine were differentially abundant (FDR ≤ 0.05; AUC > 0.80) in beef steers with divergent RADG; five metabolic pathways including steroid hormone biosynthesis, thiamine metabolism, propanoate metabolism, pentose phosphate pathway, and butanoate metabolism were enriched ( ≤ 0.05) in beef steers with positive RADG, relative to negative RADG steers. A total of 1,908 metabolites were detected and identified in the rumen of the beef steers; results of the pathway enrichment analysis of all the metabolites revealed no metabolic pathways in the rumen were altered ( > 0.05). The rumen fluid samples were also analyzed using 16S rRNA gene sequencing to assess the bacterial community composition. We compared the rumen bacterial community composition at the genus level using a linear discriminant analysis effect size (LEfSe) to identify the differentially abundant taxa between the two groups of beef steers. The LEfSe results showed greater relative abundance of _vadinHA17 and in steers with positive RADG compared to the negative RADG group, while steers in the negative RADG group had greater relative abundance of , , , , , and compared to the positive RADG group. Our results demonstrate that beef steers with positive or negative RADG exhibit differences in plasma metabolic profiles and some ruminal bacterial taxa which probably explain their divergent feed efficiency phenotypes.
PubMed: 37435477
DOI: 10.1093/tas/txad054 -
BMC Biology Dec 2021Tigecycline is a tetracycline derivative that constitutes one of the last-resort antibiotics used clinically to treat infections caused by both multiple drug-resistant...
BACKGROUND
Tigecycline is a tetracycline derivative that constitutes one of the last-resort antibiotics used clinically to treat infections caused by both multiple drug-resistant (MDR) Gram-negative and Gram-positive bacteria. Resistance to this drug is often caused by chromosome-encoding mechanisms including over-expression of efflux pumps and ribosome protection. However, a number of variants of the flavin adenine dinucleotide (FAD)-dependent monooxygenase TetX, such as Tet(X4), emerged in recent years as conferring resistance to tigecycline in strains of Enterobacteriaceae, Acinetobacter sp., Pseudomonas sp., and Empedobacter sp. To date, mechanistic details underlying the improvement of catalytic activities of new TetX enzymes are not available.
RESULTS
In this study, we found that Tet(X4) exhibited higher affinity and catalytic efficiency toward tigecycline when compared to Tet(X2), resulting in the expression of phenotypic tigecycline resistance in E. coli strains bearing the tet(X4) gene. Comparison between the structures of Tet(X4) and Tet(X4)-tigecycline complex and those of Tet(X2) showed that they shared an identical FAD-binding site and that the FAD and tigecycline adopted similar conformation in the catalytic pocket. Although the amino acid changes in Tet(X4) are not pivotal residues for FAD binding and substrate recognition, such substitutions caused the refolding of several alpha helixes and beta sheets in the secondary structure of the substrate-binding domain of Tet(X4), resulting in the formation of a larger number of loops in the structure. These changes in turn render the substrate-binding domain of Tet(X4) more flexible and efficient in capturing substrate molecules, thereby improving catalytic efficiency.
CONCLUSIONS
Our works provide a better understanding of the molecular recognition of tigecycline by the TetX enzymes; these findings can help guide the rational design of the next-generation tetracycline antibiotics that can resist inactivation of the TetX variants.
Topics: Anti-Bacterial Agents; Escherichia coli; Microbial Sensitivity Tests; Mixed Function Oxygenases; Tigecycline
PubMed: 34895224
DOI: 10.1186/s12915-021-01199-7 -
Frontiers in Microbiology 2021High concentrations of Y12 significantly inhibit the development of housefly larvae and accelerate larvae death. In this study, the dynamic distribution of the gut...
High concentrations of Y12 significantly inhibit the development of housefly larvae and accelerate larvae death. In this study, the dynamic distribution of the gut microbiota of housefly larvae fed different concentrations of Y12 was investigated. Compared with low-concentration diets, orally administered high-concentration diets caused higher mortality and had a greater impact on the community structure and interaction network of intestinal flora in housefly larvae. The bacterial community of the gut microbiota in housefly larvae was reconstructed in 4 days. Bacterial abundance and diversity were significantly reduced in housefly larvae fed high concentrations of . With the growth of larvae, the relative abundances of , , , , and increased significantly in housefly larvae fed with high concentrations of , while the relative abundances of , , , , , and were significantly reduced. To analyze the role of the gut microorganisms played on housefly development, a total of 10 cultivable bacterial species belonging to 9 genera were isolated from the intestine of housefly larvae among which , , , , and promoted the growth of larvae through feeding experiments. This study is the first to analyze the influence of high concentrations of on the gut microbiota of houseflies. Our study provides a basis for exploring the pathogenic mechanism of high concentrations of Y12 in houseflies.
PubMed: 34335517
DOI: 10.3389/fmicb.2021.691158