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NorR, as a single-target regulator, has been demonstrated to be involved in NO detoxification in bacteria under anaerobic conditions. Here, the norR gene was identified and deleted in the genome of Vibrio alginolyticus. The results showed that deletion of norR in Vibrio alginolyticus led to lower swarming motility and more biofilm formation on aerobic condition. Moreover, we proved that NorR from E. coli had a similar function in controlling motility. NorR overexpression led to increased resistance to oxidative stress and tetracycline. We also observed a reduced ability of the NorR-overexpressing strain to adapt to iron limitation condition. Transcriptome analysis showed that the genes responsible for bacterial motility and biofilm formation were affected by NorR. The expressions of several sigma factors (RpoS, RpoN, and RpoH) and response regulators (LuxR and MarR) were also controlled by NorR. Furthermore, Chip-qPCR showed that there is a direct binding between NorR and the promoter of rpoS. Based on these results, NorR appears to be a central regulator involved in biofilm formation and swarming motility in Vibrio alginolyticus. [ABSTRACT FROM AUTHOR]

Anaerobic bacteria can cause many infections in children. Because they predominant in the normal human skin and mucous membranes bacterial flora, they are often associated with bacterial infections that originate from these sites. They are difficult to isolate from infectious sites, and are frequently missed. Anaerobic infections can occur in all body sites, including the central nervous system, oral cavity, head and neck, chest, abdomen, pelvis, skin, and soft tissues. Anaerobes colonize the newborn after birth and have been isolated in several types of neonatal infections. These include cellulitis of the site of fetal monitoring, neonatal aspiration pneumonia, bacteremia, conjunctivitis, omphalitis, and infant botulism. Management of anaerobic infection is challenging because of the slow growth of these bacteria, by their polymicrobial nature and by the growing antimicrobial resistance of anaerobic. Antimicrobial therapy may be the only treatment required, and may also be an adjunct to a surgical approach. Polymicrobial aerobic-anaerobic infection generally requires delivering antimicrobial therapy effective against all pathogens. The antibiotics with the greatest activity against anaerobes include carbapenems, beta-lactam/beta-lactamase inhibitor combinations, metronidazole, and chloramphenicol. Antimicrobial resistance is growing among anaerobic bacteria. The major increased in resistance have been reported with clindamycin, cephamycins, and moxifloxacin against Bacteroides fragilis group and related strains. Resistance patterns vary between different geographic areas and medical facilities. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the impact of incremental changes in culture conditions on the survival and tolerance of sulfate-reducing bacteria (SRB) to desulfurization and H2 evolution, as acclimation enhances their adaptation to extreme environmental conditions. SRB from sewage sludge were enriched with thiosulfate as the sole energy source and then subjected to gradual acclimation to culture conditions through batch fermentation cycles. They were acclimated to incremental concentrations (50–90 mM) of various sulfur sources ((NH 4) 2 Fe(SO 4) 2 , Na 2 SO 3 , H 2 S, Na 2 S 2 O 3), nitrate (KNO 3), nitrite (KNO 2), and phosphate (KH 2 PO 4) in an assay medium with 0.5% Na 2 S 2 O 3 as the sole energy source. They were also gradually acclimated to increasing temperatures (37–60 °C), desiccation (37 -20 °C), NaCl (50–90 mM), low pressure (−30 mm/Hg for 35 d), and UVB exposure (35 d at a distance of 7 cm) in the same assay medium. The results of this study showed that acclimatized SRB exhibited maximum growth on 70 mM thiosulfate and 60 mM ammonium iron II sulfate for H 2 production. Sodium sulfite and H 2 S supported the growth but did not favor H 2 evolution. This SRB consortium could withstand growth on 80 mM phosphate and produced maximum H 2 in the presence of nitrate and nitrite at concentrations of 60 and 80 mM, respectively. The maximum survival and adaptability of the consortium were observed at 50 °C, low pressure, and 80 mM NaCl. Increasing the inoculum size increased H 2 production. The acclimatized SRB inoculum formulation achieved a maximum biohydrogen production rate of 1.101 mmol/L/d. This study offers valuable insights into the versatile adaptability of SRB and their potential for biohydrogen production during desulfurization. • The effect of acclimation to SRB survival, desulfurization, and H₂ production from thiosulfate. • SRB achieved a maximum biohydrogen production on 70 mM thiosulfate. • SRB increased their growth tolerance with 80 mM phosphate concentration. • High temperature and salinity did not affect for biohydrogen production. • The acclimated SRB inoculum achieved a maximum biohydrogen production rate of 1.101 mmol/L/d. [ABSTRACT FROM AUTHOR]

AbstractObjectiveMethodsResultsConclusionThis study aimed to describe the vaginal microbiome of women with premature ovarian insufficiency (POI) receiving systemic hormone therapy (HT).Forty women with POI receiving systemic HT for at least 6 months, who were sexually active, were included in the descriptive cross-sectional study. Vaginal secretion was collected for DNA extraction followed by pyrosequencing of the 16S rRNA. The samples were pooled into phylogenetic groups (Ravel groups I–V).Women had mean age of 37.13 (± 7.27) years and POI diagnosis at age 27.90 (± 8.68) years, and a mean HT duration of 8.20 (± 8.73) years. It was observed that 33.4% of the women presented group I flora, with a predominance of Lactobacillus crispatus; 9% group II flora, with a predominance of Lactobacillus gasseri; 33.4% group III flora, with a predominance of Lactobacillus iners; 15.2% group IV flora, with a predominance of anaerobic bacteria; and 9% group V flora, with a predominance of Lactobacillus jensenii.Women with POI receiving HT presented a vaginal microbiome with a predominance of lactobacilli in the composition of the vaginal flora, specifically L. crispatus and L. iners when evaluated by molecular biology through pyrosequencing of 16S rRNA. [ABSTRACT FROM AUTHOR]

3,6-Dichlorosalicylic acid (3,6-DCSA) is the demethylation metabolite of herbicide 3,6-dichloro-2-methoxy benzoic acid (dicamba). Previous studies have shown that anaerobic sludge further transformed 3,6-DCSA through decarboxylation and dechlorination. However, the anaerobe, enzyme, and gene involved in the anaerobic degradation of 3,6-DCSA are still unknown. In this study, an anaerobic sludge that efficiently degraded dicamba was enriched, and a 3,6-DCSA decarboxylase, designated chlorosalicylic acid decarboxylase (CsaD), was partially purified and identified from the anaerobic sludge. Metagenomic analysis showed that the csaD gene was located in a gene cluster of metagenome-assembled genome 8 (MAG8). MAG8 belonged to an uncultured order, OPB41, in the class Coriobacteriia of the phylum Actinobacteria, and its abundance increased approximately once during the enrichment process. CsaD was a non-oxidative decarboxylase in the amidohydrolase 2 family catalyzing the decarboxylation of 3,6-DCSA and 6-chlorosalicylic acid (6-CSA). Its affinity and catalytic efficiency for 3,6-DCSA were significantly higher than those for 6-CSA. This study provides new insights into the anaerobic catabolism of herbicide dicamba. IMPORTANCE Dicamba, an important hormone herbicide, easily migrates to anoxic habitats such as sediment, ground water, and deep soil. Thus, the anaerobic catabolism of dicamba is of importance. Anaerobic bacteria or sludge demethylated dicamba to 3,6-DCSA, and in a previous study, based on metabolite identification, it was proposed that 3,6-DCSA be further degraded via two pathways: decarboxylation to 2,5-dichlorophenol, then dechlorination to 3-chlorophenol (3-CP); or dechlorination to 6-CSA, then decarboxylation to 3-CP. However, there was no physiological and genetic validation for the pathway. In this study, CsaD catalyzed the decarboxylation of both 3,6-DCSA and 6-CSA, providing enzyme-level evidence for the anaerobic catabolism of 3,6-DCSA through the two pathways. CsaD was located in MAG8, which belonged to an uncultured anaerobic actinomycetes order, OPB41, indicating that anaerobic actinomycetes in OPB41 was involved in the decarboxylation of 3,6-DCSA. This study provides a basis for understanding the anaerobic catabolism of dicamba and the demethylation product, 3,6-DCSA. [ABSTRACT FROM AUTHOR]

Introduction: Vaginoplasty is performed to create a neovagina for transgender individuals who seek surgical transition or for cisgender individuals with congenital or acquired absence of a vagina (or "cisvagina"). The current knowledge of the bacterial microenvironment of the neovagina is limited. The objective of this study was to conduct a systematic review of current knowledge regarding the microbiome of the neovagina in transgender women. Methods: A systematic review of three medical databases (PubMed, MEDLINE, Web of Science) was performed in December 2021. Articles were included if they discussed the bacterial flora of the post-surgical neovagina in transgender women. Articles were excluded if their primary focus was pathogenic disease of the neovagina. Articles were summarized qualitatively and organized into a table. Results: Ten articles were identified for the review. Surgical techniques included penile inversion vaginoplasty (PIV) and intestinal/sigmoid vaginoplasty. PIV neovaginas were most similar to cisvaginas with bacterial vaginosis, whereas intestinal vaginoplasty resulted in microbiomes comparable to that of the colorectum. Oral probiotic supplements may be able to encourage the growth of Lactobacillus in the neovagina. Maintenance protocols relating to cleaning are largely surgeon- and institution-dependent, and evidence regarding the use of estrogen and its effect on the neovagina is limited. Conclusions: The microbiome of the neovagina is distinct from that of the cisvagina, and it differs based on surgical technique. Further research is warranted to better characterize the effect of different surgical techniques, patient characteristics, estrogen use, and cleaning habits on the health of the neovaginal microbiome. [ABSTRACT FROM AUTHOR]

Periodontitis and caries, while seemingly innocuous medical conditions, actually pose significant challenges because of their potential etiology with far more serious conditions. Efficacious treatment is hindered by bacterial antibiotic resistance. Standard AgNPs are ineffective against periodontal anaerobic bacteria, because they require oxidative dissolution to release Ag+ ions, which are the actual antimicrobial agents, but oxidation is not possible under anaerobic conditions. Prior studies on Ag-based periodontal antimicrobial materials either did not confirm a silver oxidation state or did not use strictly anaerobic growth media or both, causing spurious antimicrobial efficacy estimates. Here, we prove that silver ion-doped hydroxyapatite nanoparticles (AgHAp NPs) synthesized at various pHs contain an Ag+ oxidation state and directly release Ag+ even in a strictly anerobic medium. Thus, these AgHAp NPs exhibit direct antimicrobial activity against the fastidious anaerobic Gram-negative periodontal bacterium Fusobacterium nucleatum (F. nucleatum) and against caries-causing aerobic, Gram-positive bacterium Streptococcus mutans (S. mutans). The synthesis pH (6–11) correlates inversely with the Ag+ content (4.5–0.45 wt %) of AgHAp NPs and, hence, with antimicrobial efficacy, thus providing tunable efficacy for the target application. AgHAp NPs had greater antimicrobial efficacy than Ag0-containing AgNPs and were less cytotoxic to the mouse fibroblast L929 cell line. Thus, AgHAp NPs (especially AgHAp7) are superior to AgNPs as effective, broad-spectrum, biocompatible antimicrobials against both anaerobic periodontal and aerobic dental bacteria. AgHAp NP synthesis is also inexpensive and scalable, which are significant factors for treating large global populations of indigent people affected by periodontitis and dental caries. [ABSTRACT FROM AUTHOR]

Cellulase selectively recognizes cellulose surfaces and cleaves their β-1,4-glycosidic bonds. Combining hydrolysis using cellulase and fermentation can produce alternative fuels and chemical products. However, anaerobic bacteria produce only low levels of highly active cellulase complexes so-called cellulosomes. Therefore, we designed hybrid cellulase complexes from 49 biotinylated catalytic domain (CD) and 30 biotinylated cellulose-binding domain (CBD) libraries on streptavidin-conjugated nanoparticles to enhance cellulose hydrolysis by mimicking the cellulosome structure. The hybrid cellulase complex, incorporating both native CD and CBD, significantly improved reducing sugar production from cellulose compared to free native modular enzymes. The optimal CBD for each hybrid cellulase complex differed from that of the native enzyme. The most effective hybrid cellulase complex was observed with the combination of CD6-4 from Thermobifida fusca YX and CBD46 from the Bacillus halodurans C-125. The hybrid cellulase complex/CD6-4-CBD46 and -CD6-4-CBD2-5 combinations showed increased reducing sugar production. Similar results were also observed in microcrystalline cellulose degradation. Furthermore, clustering on nanoparticles enhanced enzyme thermostability. Our results demonstrate that hybrid cellulase complex structures improve enzyme function through synergistic effects and extend the lifespan of the enzyme. [ABSTRACT FROM AUTHOR]

Gut microbiome composition is tied to diseases ranging from arthritis to cancer to depression. However, mechanisms of action are poorly understood, limiting development of relevant therapeutics. Organ‐on‐chip platforms, which model minimal functional units of tissues and can tightly control communication between them, are ideal platforms to study these relationships. Many gut microbiome models are published to date but devices are typically fabricated using oxygen permeable polydimethylsiloxane, requiring interventions to support anaerobic bacteria. To address this challenge, a platform is developed where the chips are fabricated entirely from gas‐impermeable polycarbonate without tapes or gaskets. These chips replicate polarized villus‐like structures of the native tissue. Further, they enable co‐cultures of commensal anaerobic bacteria Blautia coccoides on the surface of gut epithelia for two days within a standard incubator. Another complication of commonly used materials in organ‐on‐chip devices is high ad‐/absorption, limiting applications in high‐resolution microscopy and biomolecule interaction studies. For future communication studies between gut microbiota and distal tumors, an additional polycarbonate chip design is developed to support hydrogel‐embedded tissue culture. These chips enable high‐resolution microscopy with all relevant processing done on‐chip. Designed for facile linking, this platform will make a variety of mechanistic studies possible. [ABSTRACT FROM AUTHOR]

Vaginitis is a widespread issue for women worldwide, yet current diagnostic tools are lacking. Bacterial vaginosis (BV) is the most prevalent type of vaginitis, found in 10–50% of reproductive-aged women. Current diagnostic methods for BV rely on clinical criteria, microscopy, or the detection of a few microbes by qPCR. However, many vaginal infections lack a single etiological agent and are characterized by changes in the vaginal microbiome community structure (e.g., BV is defined as a loss of protective lactobacilli resulting in an overgrowth of anaerobic bacteria). Shotgun metagenomic sequencing provides a comprehensive view of all the organisms present in the vaginal microbiome (VMB), allowing for a better understanding of all potential etiologies. Here, we describe a robust VMB metagenomics sequencing test with a sensitivity of 93.1%, a specificity of 90%, a negative predictive value of 93.4%, and a positive predictive value of 89.6% certified by Clinical Laboratory Improvement Amendments (CLIA), the College of American Pathologist (CAP), and the Clinical Laboratory Evaluation Program (CLEP). We sequenced over 7000 human vaginal samples with this pipeline and described general findings and comparisons to US census data. [ABSTRACT FROM AUTHOR]

Dysbiosis within microbiomes has been increasingly implicated in many systemic illnesses, such as cardiovascular disease, metabolic syndrome, respiratory infections, and Alzheimer disease (Ad). The correlation between Ad and microbial dysbiosis has been repeatedly shown, yet the etiologic cause of microbial dysbiosis remains elusive. From a neuropathology perspective, abnormal (often age-related) changes in the brain, associated structures, and bodily lumens tend toward an accumulation of oxygen-depleted pathologic structures, which are anaerobically selective niches. These anaerobic environments may promote progressive change in the microbial community proximal to the brain and thus deserve further investigation. In this review, we identify and explore what is known about the anaerobic niche near or associated with the brain and the anaerobes that it is harbors. We identify the anaerobe stakeholders within microbiome communities and the impacts on the neurodegenerative processes associated with Ad. Chronic oral dysbiosis in anaerobic dental pockets and the composition of the gut microbiota from fecal stool are the 2 largest anaerobic niche sources of bacterial transference to the brain. At the blood-brain barrier, cerebral atherosclerotic plaques are predominated by anaerobic species intimately associated with the brain vasculature. Focal cerebritis/brain abscess and corpora amylacea may also establish chronic anaerobic niches in direct proximity to brain parenchyma. In exploring the anaerobic niche proximal to the brain, we identify research opportunities to explore potential sources of microbial dysbiosis associated with Ad. [ABSTRACT FROM AUTHOR]

Background and Purpose: This study analyses whether first‐line antihypertensive drugs ameliorate the dysbiosis state in hypertension, and to test if this modification contributes to their blood pressure (BP) lowering properties in a genetic model of neurogenic hypertension. Experimental Approach: Twenty‐week‐old male Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were untreated or treated with captopril, amlodipine or hydrochlorothiazide. A faecal microbiota transplantation (FMT) experiment was also performed by gavage of faecal content from donor SHR‐treated groups to SHR recipients for 3 weeks. Key results: Faeces from SHR showed gut dysbiosis, characterized by lower acetate‐ and higher lactate‐producing bacteria and lower strict anaerobic bacteria. All three drugs increased the anaerobic bacteria proportion, captopril and amlodipine restored the proportion of acetate‐producing bacterial populations to WKY levels, whereas hydrochlorothiazide decreased butyrate‐producing bacteria. Captopril and amlodipine decreased gut pathology and permeability and attenuated sympathetic drive in the gut. Both drugs decreased neuroinflammation and oxidative stress in the hypothalamic paraventricular nuclei. Hydrochlorothiazide was unable to reduce neuroinflammation, gut sympathetic tone and gut integrity. FMT from SHR‐amlodipine to SHR decreased BP, ameliorated aortic endothelium‐dependent relaxation to acetylcholine, lowered NADPH oxidase activity, aortic Th17 infiltration and reduced neuroinflammation, whereas FMT from SHR‐hydrochlorothiazide did not have these effects. Conclusions and Implications: First‐line antihypertensive drugs induced different modifications of gut integrity and gut dysbiosis in SHR, which result in no contribution of microbiota in the BP lowering effects of hydrochlorothiazide, whereas the vasculo‐protective effect induced by amlodipine involves gut microbiota reshaping and gut‐immune system communication. [ABSTRACT FROM AUTHOR]

Adverse effects and multidrug resistance remain significant obstacles in conventional cancer therapy. Nanomedicines, with their intrinsic properties such as nano-sized dimensions and tunable surface characteristics, have the potential to mitigate the side effects of traditional cancer treatments. While nanomaterials have been widely applied in cancer treatment, challenges such as low targeting efficiency and poor tumor penetration persist. Recent research has shown that anaerobic bacteria exhibit high selectivity for primary tumors and metastatic cancers, offering good safety and superior tumor penetration capabilities. This suggests that combining nanomaterials with bacteria could complement their respective limitations, opening vast potential applications in cancer therapy. The use of bacteria in combination with nanomaterials for anticancer treatments, including chemotherapy, radiotherapy, and photothermal/photodynamic therapy, has contributed to the rapid development of the field of bacterial oncology treatments. This review explores the mechanisms of bacterial tumor targeting and summarizes strategies for synthesizing bacterial-nanomaterial and their application in cancer therapy. The combination of bacterial-nanomaterial hybrids with modern therapeutic approaches represents a promising avenue for future cancer treatment research, with the potential to improve treatment outcomes for cancer patients. [ABSTRACT FROM AUTHOR]

Full-scale hostilities in Ukraine led to an unprecedented number of victims with serious injuries, including gunshot wounds, broken bones, and mine-explosive injuries. Wound infections are one of the main causes of non-combat losses of personnel. A prerequisite for the development of a wound infection, among other things, is high microbial contamination of combat wounds. Major bacteria causing such infections are staphylococci (Staphylococcus aureus, S. epidermidis), streptococci (Streptococcus pyogenes, St. agalictiae), enterococci (Enterococcus faecalis), gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii), anaerobic bacteria (Clostridium perfringens, Bacterioides spp.), etc. Modern data indicate a change in the current species composition of causative agents of wound infections, an increase both in the polyresistance of the microbiota to antibacterial drugs and in the frequency of biofilm formation protecting pathogenic microorganisms from antimicrobial therapy and the patient's immune response. Such purulent bacterial infections require new approaches to therapy. Taking into account the large number of combat injuries in Ukraine, the use of bacteriophages as specific agents for the biological control of pathogenic microbiota is of particular importance. In view of the nature of injuries, phage preparations intended for the treatment of purulent-surgical infections of wound and burn surfaces are considered the most promising and in demand today. This review summarizes modern data on the use of phage preparations in clinics and in orthopedics and traumatology in particular. Issues of the delivery of phages to the focus of infection, their effective dose, duration of therapy, and the possibility of combining it with antibiotic therapy are discussed. Information about phage therapy programs that have already been implemented in some countries is presented. The advantages and disadvantages of the use of bacteriophages for personalized therapy of severe patients are highlighted, and the prospects for further research are indicated. [ABSTRACT FROM AUTHOR]

Metastatic cancers are responsible for 90% of cancer related deaths and melanoma is known as one of the deadliest cancers. Dacarbazine (DTIC) for metastatic melanoma has become an approved first-line treatment in routine clinical practice. However, response rates to single-drug therapy with dacarbazine are quite low. Therefore, combination drug therapy as a method of treatment that combines two or more therapeutic agents is the cornerstone of cancer therapy. Here, we examined the effects of the combination of ornidazole, a derivative of 5-nitroimidazole which is active against protozoa and anaerobic bacteria, and DTIC on melanoma cells to investigate novel advanced combination therapies for melanoma. Doses in this study are 0, 800 and 1200µg/mL for ornidazole, 0, 5, 25, 50, 100, 200, 300, 600, 1200μM/L for DTIC and 800µg/mL+100μM/L, 800µg/mL+200μM/L, 1200µg/mL+100μM/L, 1200µg/mL+200μM/L for ornidazole+DTIC combination. Treatment effect of ornidazole and DTIC as a single-agents and in combination on cell viability was investigated with crystal violet and MTT assays. As well as the effect of them on migration ability was assessed by wound healing assay, the effect of them on DNA damage induction was evaluated by comet assay in B16F10 melanoma cells in vitro. Our data showed that combination treatment with ornidazole and DTIC markedly inhibited cancer cell proliferation and migration. DNA damage was also significantly induced by this combination treatment. Our study showed that ornidazole/DTIC combination drug therapy has more effective therapeutic potential for melanoma compared to DTIC therapy alone. In conclusion, our findings suggest that combination therapy with ornidazole/ DTIC could serve as a new and valuable approach for melanoma treatment. [ABSTRACT FROM AUTHOR]

Fecal sterols are traditionally ascribed as important biomarkers for animal excrement, and have been widely used to identify the source of organic matter and to reconstruct paleoecological changes in Antarctic terrestrial, aquatic, and marine ecosystems. However, the in situ microbial hydrogenation of cholesterol to coprostanol could have significance as a proxy to infer paleoenvironmental studies in Antarctica, particularly in anoxic sediment. Here, we report that abundant coprostanol, which was traditionally deemed as a biomarker for human sewage contamination, was found in three anoxic sediment profiles (AC2, BI, and CH1), which were strongly influenced by animal excrement at North Victoria Land, western Ross Sea, Antarctica. Our results suggest that the high concentrations of coprostanol in these three sediment profiles were not due to animal excrement, since coprostanol is not present in penguin guano and is a minor component in seal excrement. Coprostanol/cholesterol and coprostanol/(coprostanol + cholestanol) ratios suggest that coprostanol in the sediment cores of AC2 and BI was primarily derived from bacterial hydrogenation of cholesterol introduced by penguin guano. Coprostanol in CH1 sediments is related to human sewage due to intensive research activities from 1968 to 2006 in this region. However, the low abundance of coprostanol and the ratios of coprostanol/cholesterol and coprostanol/(coprostanol + cholestanol) in a relatively oxidizing sediment core (IIL1) infer that coprostanol was likely contributed by seal settlement. Together with high-throughput sequencing of the 16S rRNA gene, the conversion of cholesterol to coprostanol by anaerobic bacteria (e.g., Eubacterium coprostanoligenes) could occur in anoxic aquatic systems. Our results suggest that the presence of coprostanol in Antarctic lacustrine sediment with anoxic conditions does not necessarily indicate seal activity and human waste as the microbial hydrogenation of cholesterol to coprostanol should also be considered. [ABSTRACT FROM AUTHOR]

The antimicrobial effects of high hydrostatic pressure (HHP) treatments on chill‐stored seafood are well‐documented, while their impact on the metabolic profile of seafood, especially the metabolome of fish flesh, and remains underexplored. Addressing this gap, this study investigates the effects of HHP on the metabolome of chill‐stored rose shrimp by conducting multivariate data analysis based on untargeted proton nuclear magnetic resonance observations. Vacuum‐packed rose shrimp samples were subjected to HHP at 0, 400, 500, and 600 MPa for 10 min and then stored at 2–4°C. The microorganism analysis and metabolic analysis were carried out on days 1 and 14. HHP treatment effectively deactivated Lactobacillus spp., Escherichia coli, Pseudomonas spp., total Coliforms, and sulfite‐reducing anaerobic bacteria. Consequently, HHP treatment significantly reduced the formation rate of decay‐related metabolites, such as hypoxanthine, trimethylamine, and biogenic amines, which exhibited significant accumulation in untreated samples. Multivariate unsupervised analyses provided insights into the overall changes in the metabolite profile induced by HHP. Metabolic pathway analysis revealed several pathways underlying spoilage, including pyruvate metabolism, valine, leucine, and isoleucine biosynthesis, purine metabolism, methane metabolism, glycine, serine, and threonine metabolism, citrate cycle (TCA cycle), glycolysis/gluconeogenesis, alanine, aspartate, and glutamate metabolism, sulfur metabolism, pantothenate and CoA biosynthesis, glutathione metabolism, and glyoxylate and dicarboxylate metabolism. Importantly, these pathways underwent alterations due to the application of HHP, particularly at high‐pressure levels. In summary, the results unveil the potential mechanisms of HHP effects on chill‐stored rose shrimps. [ABSTRACT FROM AUTHOR]

The acetogen Acetobacterium woodii couples caffeate reduction with ferredoxin reduction and NADH oxidation via electron bifurcation, providing additional reduced ferredoxin for energy conservation and cell synthesis. Caffeate is first activated by an acyl-CoA synthetase (CarB), which ligates CoA to caffeate at the expense of ATP. After caffeoyl-CoA is reduced to hydrocaffeoyl-CoA, the CoA moiety in hydrocaffeoyl-CoA could be recycled for caffeoyl-CoA synthesis by an ATP-independent CoA transferase (CarA) to save energy. However, given that CarA and CarB are co-expressed, it was not well understood how ATP could be saved when both two competitive pathways of caffeate activation are present. Here, we reported a dual feedback inhibition of the CarB-mediated caffeate activation by the intermediate hydrocaffeoyl-CoA and the end-product hydrocaffeate. As the product of CarA, hydrocaffeate inhibited CarB-mediated caffeate activation by serving as another substrate of CarB with hydrocaffeoyl-CoA produced. It effectively competed with caffeate even at a concentration much lower than caffeate. Hydrocaffeoyl-CoA formed in this process can also inhibit CarB-mediated caffeate activation. Thus, the dual feedback inhibition of CarB, together with the faster kinetics of CarA, makes the ATP-independent CarA-mediated CoA loop the major route for caffeoyl-CoA synthesis, further saving ATP in the caffeate-dependent electron-bifurcating pathway. A genetic architecture similar to carABC has been found in other anaerobic bacteria, suggesting that the feedback inhibition of acyl-CoA ligases could be a widely employed strategy for ATP conservation in those pathways requiring substrate activation by CoA. [ABSTRACT FROM AUTHOR]

Orbital cellulitis is an uncommon condition with risks to sight and life. As a complication of maxillofacial injuries, the literature suggests this is only possible with fractures or direct inoculation, and there are no reports to the contrary. Here, we make the first report of a possible etiology by which orbital cellulitis developed in a 14-year-old boy even without skin breach or bony fractures; as well as a rare causative pathogen. He presented with facial abscess and progressive orbital cellulitis after blunt facial trauma, requiring functional endoscopic sinus surgery with needle aspiration of facial abscess externally. Cultures showed growth of Streptococcus constellatus/Parvimonas micra, and he received further antibiotics with full recovery. The pathophysiology of orbital cellulitis in this patient is attributed to vascular congestion and local pressure from maxillofacial contusion and maxillary hemoantrum, with impaired paranasal sinus ventilation encouraging anaerobic bacterial growth. Further progression led to facial abscess formation and intraorbital spread with orbital cellulitis. The pediatric demographic is injury-prone, and self-reporting of symptoms can be delayed. Hence, increased suspicion of complicated injuries and orbital cellulitis may be required when managing maxillofacial contusions so that prompt treatment can be given. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to evaluate antibiotic susceptibility and antimicrobial resistance trends among clinically significant anaerobes in Kuwait hospitals from 2013 to 2022, comparing these findings with data from 2002 to 2012. Methods: The study prospectively collected 2,317 anaerobic isolates from various body sites across four Kuwaiti hospitals between January 2013 and December 2022. The minimum inhibitory concentrations for 11 antianaerobic antibiotics were determined using E-test methodology. The study analyzed trends and resistance rates across two periods: 2013–2017 and 2018–2022, using statistical analysis for resistance comparison. Results: Of the 2,317 isolates, most were from wounds (42.2%), fluids (28.0%), and tissues (20.5%). Bacteroides fragilis was the most common pathogen (34.0%), followed by Prevotella bivia (13.4%). Over 90% of isolates were susceptible to imipenem, meropenem, tigecycline, and metronidazole, whereas lower susceptibility was observed for penicillin, amoxicillin–clavulanic acid, and clindamycin. Notable differences in resistance profiles since 2002 were observed, especially in amoxicillin–clavulanic acid, piperacillin, piperacillin–tazobactam, and clindamycin. Conclusion: Owing to detected resistance to all antibiotics, susceptibility testing for anaerobic isolates is recommended in severe infections to ensure effective antimicrobial therapy. Continuous surveillance is crucial for developing antibiotic policies to manage invasive anaerobic infections. [ABSTRACT FROM AUTHOR]

Porphyromonas gingivalis is a gram‐negative anaerobic bacterium recognized for its pivotal role in the pathogenesis of periodontal diseases. This review covers an overview of the virulence factors and lifecycle stages of P. gingivalis, with a specific focus on attachment and colonization, biofilm formation, growth and multiplication, dormancy survival and dissemination. Additionally, we explore the significance of inter‐bacterial cross‐feeding within biofilms. Furthermore, we discuss potential phytochemical‐based strategies to target P. gingivalis, including the use of curcumin, apigenin, quercetin and resveratrol. Understanding the virulence factors and lifecycle stages of P. gingivalis, along with the promising phytochemical‐based interventions, holds promise for advancing strategies in periodontal disease management and oral health promotion. [ABSTRACT FROM AUTHOR]

The abiotic/abiotic hybrid S@UIL system enhances ICD-associated antitumor effects by inducing excessive autophagy and mild-temperature photothermal therapy. [Display omitted] The tumor microenvironment, characterized by hypoxia, supports the efficacy of anaerobic bacteria like attenuated S. typhimurium in cancer therapies. These bacteria target and penetrate deep tumor regions, significantly reducing tumor size but often lead to tumor regrowth due to limited long-term efficacy. To enhance the therapeutic impact, a novel biohybrid system, S@UIL, has been developed by coating S. typhimurium with a zirconium-based nanoscale metal–organic framework (UiO-66-NH 2) loaded with indocyanine green (ICG) and luteolin (LUT). This system maintains the bacteria's tumor-targeting ability while increasing the penetration and therapeutic effectiveness through excessive autophagy and mild hyperthermia. In a subcutaneous colon cancer model, the integration of LUT and ICG promotes autophagic cell death and photothermal sensitization, leading to the release of damage-associated molecular patterns (DAMPs). These DAMPs activate immune responses through dendritic cells and T -cells, enhancing immunogenic cell death (ICD) and potentially reducing immune evasion by tumors. This single-administration approach also integrates multimodal imaging capabilities, providing a promising strategy for improved tumor ICD induction and cancer progression inhibition. [ABSTRACT FROM AUTHOR]

Fusobacterium nucleatum, a gram‐negative anaerobic bacterium abundantly found in the human oral cavity, is widely recognized as a key pathobiont responsible for the initiation and progression of periodontal diseases due to its remarkable aggregative capabilities. Numerous clinical studies have linked F. nucleatum with unfavorable prognostic outcomes in various malignancies. In further research, scholars have partially elucidated the mechanisms underlying F. nucleatum's impact on various types of cancer, thus gaining a certain comprehension of the role played by F. nucleatum in cancer. In this comprehensive review, we present an in‐depth synthesis of the interplay between F. nucleatum and different cancers, focusing on aspects such as tumor initiation, metastasis, chemoresistance, and modulation of the tumor immune microenvironment and immunotherapy. The implications for cancer diagnosis and treatment are also summarized. The objective of this review is to enhance our comprehension of the intricate relationship between F. nucleatum and oncogenic pathogenesis, while emphasizing potential therapeutic strategies. [ABSTRACT FROM AUTHOR]

The rumen microbiota is critical in cattle digestion. Still, its low cultivability makes it difficult to study its ecological function and biotechnological potential. To improve the recovery of ruminal microorganisms, this study combined the evaluation of several cultivation parameters with metabarcoding analysis. The parameters tested comprised eight media cultures, three sample dilutions (10−2, 10−6, 10−12), and two incubation times (3 and 7 days). Bacterial populations were determined through Illumina sequencing of 16S rRNA from three biological replicates. The results indicate that none of the culture media recovered all rumen populations and that there was an altered relative abundance of the dominant phyla. In the rumen, Bacteroidetes and Firmicutes comprised 75% and 15% of the relative abundance, respectively, while in the culture media, these were 15% and 60%, respectively. Principal coordinate analysis (PCoA) of the bacterial community revealed significant shifts in population composition due to dilution, with 10−2 and 10−6 dilutions clustered closely while the 10−12 dilution differed markedly. In contrast, incubation duration did not influence population diversity. According to the results, two media, CAN and KNT, were selected based on their ability to recover more similar populations compared to the rumen sample. The metataxonomic study showed that CAN media had consistent reproducibility over time, while KNT showed enrichment of different taxa due to the use of rumen fluid as a substrate. From these, 64 pure cultures were obtained and 54 were identified through 16S rRNA gene sequencing. Being Streptococcus the most frequently isolated genus, this prevalence contrasts with the liquid media composition, underscoring the importance of refining single colony isolation strategies. Although no culture medium could replicate the native rumen bacterial population perfectly, our findings highlight the potential of CAN and KNT media in recovering populations that are more closely aligned to natural rumen conditions. In conclusion, our study emphasizes the importance of integrating molecular approaches in selecting suitable cultivation media and parameters to depict rumen bacteria accurately. [ABSTRACT FROM AUTHOR]

The gut microbiota is one of the most important components of homeostasis, and is closely related to the health of animals. Probiotics are often used to improve microbiota, regulate immunity, alleviate diseases, and maintain health. Clostridium butyricum is a butyric acid-producing Gram-positive anaerobic bacterium of the genus Clostridium in the family Bacillaceae that grows and reproduces rapidly. It has good bile salt tolerance, hydrophobicity and self-aggregation. Clostridium butyricum can effectively alleviate intestinal inflammation and enhance animal health by regulating intestinal immunity, improving intestinal barrier function, regulating intestinal microbiota structure and other mechanisms. In addition, Clostridium butyricum also has the potential to resist stress and improve animal production performance. The paper reviews the research progress of Clostridium butyricum in the regulation of animal intestinal health, including its physicochemical properties, mechanism of action, and application effects on intestinal functions. It aims to provide a reference for the in-depth research and practical application of Clostridium butyricum. [ABSTRACT FROM AUTHOR]

The management of patients with inflammatory bowel disease (IBD) aims to control inflammation through the use of immunosuppressive treatments that target various points in the inflammatory cascade. However, the efficacy of these therapies in the long term is limited, and they often are associated with severe side effects. Although the pathophysiology of the disease is not completely understood, IBD is regarded as a multifactorial disease that occurs due to an inappropriate immune response in genetically susceptible individuals. The gut microbiome is considered one of the main actors in the development of IBD. Gut dysbiosis, characterised by significant changes in the composition and functionality of the gut microbiota, often leads to a reduction in bacterial diversity and anti-inflammatory anaerobic bacteria. At the same time, bacteria with pro-inflammatory potential increase. Although changes in microbiome composition upon biological agent usage have been observed, their role as biomarkers is still unclear. While most studies on IBD focus on the intestinal bacterial population, recent studies have highlighted the importance of other microbial populations, such as viruses and fungi, in gut dysbiosis. In order to modulate the aberrant immune response in patients with IBD, researchers have developed therapies that target different players in the gut microbiome. These innovative approaches hold promise for the future of IBD treatment, although safety concerns are the main limitations, as their effects on humans remain unknown. [ABSTRACT FROM AUTHOR]

Infection is among the most common factors that impede wound healing, yet standard treatments routinely fail to resolve chronic wound infections. The chronic wound environment is largely hypoxic/anoxic, and wounds are predominantly colonised by facultative and obligate anaerobic bacteria. Oxygen (O2) limitation is an underappreciated driver of microbiota composition and behaviour in chronic wounds. In this perspective article, we examine how anaerobic bacteria and their distinct physiologies support persistent, antibiotic‐recalcitrant infections. We describe the anaerobic energy metabolisms bacteria rely on for long‐term survival in the wound environment, and why many antibiotics become less effective under hypoxic conditions. We also discuss obligate anaerobes, which are among the most prevalent taxa to colonise chronic wounds, yet their potential roles in influencing the microbial community and wound healing have been overlooked. All of the most common obligate anaerobes found in chronic wounds are opportunistic pathogens. We consider how these organisms persist in the wound environment and interface with host physiology to hinder wound healing processes or promote chronic inflammation. Finally, we apply our understanding of anaerobic physiologies to evaluate current treatment practices and to propose new strategies for treating chronic wound infections. [ABSTRACT FROM AUTHOR]

The intricate relationship between regeneration and microbiota has recently gained attention, spanning diverse model organisms. Axolotl (Ambystoma mexicanum) is a critically endangered salamander species and a model organism for regenerative and developmental biology. Despite its significance, a noticeable gap exists in understanding the interplay between axolotl regeneration and its microbiome. Here, we analyse in depth bacterial 16S rRNA amplicon dataset that we reported before as data resource and profile fungal community by sequencing ITS amplicons at the critical stages of limb regeneration (0–1–4–7–30–60 days post amputation, ‘dpa’). Results reveal a decline in richness and evenness in the course of limb regeneration, with bacterial community richness recovering beyond 30 dpa unlike fungi community. Beta diversity analysis reveals precise restructuring of the bacterial community along the three phases of limb regeneration, contrasting with less congruent changes in the fungal community. Temporal dynamics of the bacterial community highlight prevalent anaerobic bacteria in initiation phase and Flavobacterium bloom in the early phase correlating with limb blastema proliferation. Predicted functional analysis mirrors these shifts, emphasising a transition from amino acid metabolism to lipid metabolism control. Fungal communities shift from Blastomycota to Ascomycota dominance in the late regeneration stage. Our findings provide ecologically relevant insights into stage specific role of microbiome contributions to axolotl limb regeneration. [ABSTRACT FROM AUTHOR]

Diabetic foot infection imposes a significant burden and is the major cause of nontraumatic limb amputation. Adequate patient management with effective antibiotic therapy is crucial. This retrospective cohort study aimed to characterize the microbiology and resistance patterns of moderate to severe neuropathic diabetic foot infection in patients hospitalized at a tertiary referral hospital between January 2020 and June 2023. Deep tissue specimens from ulcers were collected for culture. Sixty inpatients were included (62% male, mean age 59.1 ± 11.5 years). Osteomyelitis was present in 90% of the patients. Among 102 microorganisms (average of 1.91 ± 1.25 pathogens per patient), 60.8% were gram-positive bacteria, 31.4% were gram-negative, 3.92% were anaerobic bacteria, and 3.92% were fungi. Staphylococcus aureus (19%) and Enterococcus faecium (17%) were the most common. Pseudomonas aeruginosa (8%) and bacteria of the Enterobacterales family (24%) accounted for all the isolated gram-negative bacteria. Sixteen percent of Staphylococcus aureus and 67% of coagulase-negative Staphylococci were resistant to methicillin. Resistance to ampicillin was found in 11% of Enterococci. All Pseudomonas aeruginosa isolates were sensitive to piperacillin-tazobactam, ceftazidime, or cefepime. Among the Enterobacterales, resistance rates were 35% for piperacillin-tazobactam, 38% for ceftazidime, 21% for cefepime, and 13% for carbapenems. Although the prevalence of methicillin-resistant staphylococci was lower than that in other studies, carbapenem resistance among gram-negative bacteria warrants attention. This study highlights the importance of understanding local epidemiology for effective diabetic foot infection management and resistance mitigation. [ABSTRACT FROM AUTHOR]

Phloroglucinol (1,3,5-trihydroxybenzene) is a key intermediate in the degradation of polyphenols such as flavonoids and hydrolysable tannins and can be used by certain bacteria as a carbon and energy source for growth. The identification of enzymes that participate in the fermentation of phloroglucinol to acetate and butyrate in Clostridia was recently reported. In this study, we present the discovery and characterization of a novel metabolic pathway for phloroglucinol degradation in the bacterium Collinsella sp. zg1085, from marmot respiratory tract. In both the Clostridial and Collinsella pathways, phloroglucinol is first reduced to dihydrophoroglucinol by the NADPH-dependent phloroglucinol reductase (PGR), followed by ring opening to form (S)-3-hydroxy-5-oxohexanoate by a Mn2+-dependent dihydrophloroglucinol cyclohydrolase (DPGC). In the Collinsella pathway, (S)-3-hydroxy-5-oxohexanoate is then cleaved to form malonate semialdehyde and acetone by a newly identified aldolase (HOHA). Finally, a NADP+-dependent malonate-semialdehyde dehydrogenase converts malonate semialdehyde to CO2 and acetyl-CoA, an intermediate in carbon and energy metabolism. Recombinant expression of the Collinsella PGR, DPGC, and HOHA in E. coli enabled the conversion of phloroglucinol into acetone, providing support for the proposed pathway. Experiments with Olsenella profusa, another bacterium containing the gene cluster of interest, show that the PGR, DPGC, HOHA, and MSDH are induced by phloroglucinol. Our findings add to the variety of metabolic pathways for the degradation of phloroglucinol, a widely distributed phenolic compound, in the anaerobic microbiome. [ABSTRACT FROM AUTHOR]

Veillonella spp. are nitrate-reducing bacteria with anaerobic respiratory activity that reduce nitrate to nitrite. They are obligate anaerobic, Gram-negative cocci that ferment lactate as the main carbon source and produce short-chain fatty acids (SCFAs). Commensal Veillonella reside in the human body site where lactate level is, however, limited for Veillonella growth. In this study, nitrate was shown to promote the anaerobic growth of Veillonella in the lactate-deficient media. We aimed to investigate the underlying mechanisms and the metabolism involved in nitrate respiration. Nitrate (15 mM) was demonstrated to promote Veillonella dispar growth and viability in the tryptone-yeast extract medium containing 0.5 mM L-lactate. Metabolite and transcriptomic analyses revealed nitrate enabled V. dispar to actively utilize glutamate and aspartate from the medium and secrete tryptophan. Glutamate or aspartate was further supplemented to a medium to investigate individual catabolism during nitrate respiration. Notably, nitrate was demonstrated to elevate SCFA production in the glutamate-supplemented medium, and further increase tryptophan production in the aspartate-supplemented medium. We proposed that the increased consumption of glutamate provided reducing power for nitrate respiration and aspartate served as a substrate for fumarate formation. Both glutamate and aspartate were incorporated into the central metabolic pathways via reverse tricarboxylic acid cycle and were linked with the increased production of acetate, propionate, and tryptophan. This study provides further understanding of the promoted growth and metabolic mechanisms by commensal V. dispar utilizing nitrate and specific amino acids to adapt to the lactate-deficient environment. [ABSTRACT FROM AUTHOR]

Glucuronoyl esterases (GEs) are carbohydrate active enzymes in carbohydrate esterase family 15 which are involved in the hydrolysis of lignin-carbohydrate complexes. They are encoded by a wide range of aerobic and anaerobic fungi and bacteria inhabiting diverse environments. The rumen microbiome is a complex microbial community with a wide array of enzymes that specialize in deconstructing plant cell wall carbohydrates. Enzymes from the rumen tend to show low similarity to homologues found in other environments, making the rumen microbiome a promising source for the discovery of novel enzymes. Using a combination of phylogenetic and structural analysis, we investigated the structure-function relationship of GEs from the rumen bacteria Fibrobacter succinogenes and Ruminococcus flavefaciens, and from the rumen fungus, Piromyces rhizinflata. All adopt a canonical α/β hydrolase fold and possess a structurally conserved Ser-His-Glu/Asp catalytic triad. Structural variations in the enzymes are localized to loops surrounding the active site. Analysis of the active site structures in these enzymes emphasized the importance of structural plasticity in GEs with non-canonical active site conformations. We hypothesize that interkingdom HGT events may have contributed to the diversity of GEs in the rumen, and this is demonstrated by the phylogenetic and structural similarity observed between rumen bacterial and fungal GEs. This study advances our understanding of the structure-function relationship in glucuronoyl esterases and illuminates the evolutionary dynamics that contribute to enzyme diversity in the rumen microbiome. [ABSTRACT FROM AUTHOR]

The potential involvement of the gut microbiota in metabolic dysfunction‐associated steatohepatitis (MASH) pathogenesis has garnered increasing attention. In this study, we elucidated the link between high‐fat/cholesterol/cholate‐based (iHFC)#2 diet‐induced MASH progression and gut microbiota in C57BL/6 mice using antibiotic treatments. Treatment with vancomycin (VCM), which targets gram‐positive bacteria, exacerbated the progression of liver damage, steatosis, and fibrosis in iHFC#2‐fed C57BL/6 mice. The expression levels of inflammation‐ and fibrosis‐related genes in the liver significantly increased after VCM treatment for 8 weeks. F4/80+ macrophage abundance increased in the livers of VCM‐treated mice. These changes were rarely observed in the iHFC#2‐fed C57BL/6 mice treated with metronidazole, which targets anaerobic bacteria. A16S rRNA sequence analysis revealed a significant decrease in α‐diversity in VCM‐treated mice compared with that in placebo‐treated mice, with Bacteroidetes and Firmicutes significantly decreased, while Proteobacteria and Verrucomicrobia increased markedly. Finally, VCM treatment dramatically altered the level and balance of bile acid (BA) composition in iHFC#2‐fed C57BL/6 mice. Thus, the VCM‐mediated exacerbation of MASH progression depends on the interaction between the gut microbiota, BA metabolism, and inflammatory responses in the livers of iHFC#2‐fed C57BL/6 mice. [ABSTRACT FROM AUTHOR]

Diversity of extremophilic microorganisms in mud volcanoes is largely unexplored. Here we report the isolation of a novel alkaliphilic, mesophilic, fermentative bacterium (strain FN5sucT) from a terrestrial mud volcano located at the Taman Peninsula, Russia. Cells of strain FN5sucT are gram-stain-positive, non-sporeforming, motile rods. The temperature range for growth is 10–37°C, with an optimum at 30°C. The pH range for growth is 7.5–10.0, with an optimum at pH 9.0. The isolate utilizes various organic polymeric substances, organic acids, carbohydrates, and proteinaceous compounds. The end products of carbohydrates fermentation are acetate, CO2 and trace amounts of H2 and formate. The major cellular fatty acid compounds are C16:0, C16:1 ω7c, and monounsaturated dimethyl acetal C14:1. Phylogenetic analysis reveals that strain FN5sucT is most closely related to Petrocella atlantisensis = DSM 105309T (98.4% 16S rRNA gene identity). The total size of the genome of strain FN5sucT is 3.35 Mb, and a genomic DNA G+C content is 37.0 mol %. The genome contains complete glycolisis/glyconeogenesis pathway. We propose to assign strain FN5sucT to the genus Petrocella, as a new species, Petrocella pelovolcani sp. nov. The type strain is FN5sucT (=DSM 113898T = UQM 41591T). [ABSTRACT FROM AUTHOR]

Clindamycin is a lincosamide antibiotic that has been used as a topical, oral, or injectable formulation for over five decades. It exhibits a narrow spectrum of microbiologic activity, primarily against gram-positive and anaerobic bacteria. In dermatology, clindamycin has been used primarily as a topical agent, usually for the treatment of acne vulgaris. Despite questions surrounding antibiotic resistance and/or its relative contribution to antibiotic treatment efficacy, a large body of data support the therapeutic value of topical clindamycin for acne vulgaris. As a systemic agent, clindamycin is used orally to treat a variety of cutaneous bacterial infections, and sometimes for acne vulgaris, with oral treatment for the latter less common in more recent years. The modes of action of clindamycin are supported by data showing both its anti-inflammatory and antibiotic mechanisms, which are discussed here along with pharmacokinetic profiles and structure-activity relationships. The diverse applications of clindamycin for multiple disease states, its efficacy, and safety considerations are also reviewed here, including for both topical and systemic formulations. Emphasis is placed on uses in dermatology, but other information on clindamycin relevant to clinicians is also discussed. [ABSTRACT FROM AUTHOR]

Timely pathogen identification in bloodstream infections is crucial for patient care. A comparison is made between positive blood culture (BC) pellets from serum separator tubes using a direct identification (DI) method and colonies on agar plates from a short-term incubation (STI) method with a matrix-assisted laser desorption/ionization Biotyper for the evaluation of 354 monomicrobial BCs. Both the DI and STI methods exhibited similar identification rates for different types of bacteria, except for Gram-positive and anaerobic bacteria. The DI method's results aligned closely with the STI method's results for Enterobacterales, glucose-non-fermenting Gram-negative bacilli (GNB), and carbapenem-resistant Enterobacterales. The DI method exhibited high concordance with the conventional method for GNB identification, achieving 88.2 and 87.5% accuracy at the genus and species levels, respectively. Compared with the STI method, the DI method showed a less successful performance for Gram-positive bacterial identification (50.5 vs. 71.3%; p < 0.01). The DI method was useful for anaerobic bacterial identification of slow-growing microorganisms without any need for colony growth, unlike in the STI method (46.7 vs. 13.3%; p = 0.04). However, both methods could not identify yeast in positive BCs. Overall, the DI method provided reliable results for GNB identification, offering many advantages over the STI method by significantly reducing the turnaround time and enabling quicker pathogen identification in positive BCs. [ABSTRACT FROM AUTHOR]

Background Clinicians variably obtain anaerobic blood cultures as part of sepsis evaluations in the neonatal intensive care unit (NICU). Our objective was to determine if anaerobic blood culture bottles yielded clinically relevant information by either recovering pathogens exclusively or more rapidly than the concurrently obtained aerobic culture bottle in the NICU. Methods A retrospective cohort study of blood cultures obtained from infants admitted to the NICU from August 01, 2015 to August 31, 2023. Standard practice was to inoculate 2 mL of blood divided equally between an aerobic and an anaerobic culture bottle. We analyzed positive blood cultures where both aerobic and anaerobic bottles were obtained and compared pathogen recovery and time to positivity between the bottles. Results During the study period, 4599 blood cultures were obtained from 3665 infants, and 265 (5.8%) were positive. Of these, 182 cultures were sent as aerobic–anaerobic pairs and recovered pathogenic organisms. Organisms were recovered exclusively from the anaerobic bottle in 32 (17.6%) cultures. Three organisms were obligate anaerobes; the rest were facultative anaerobes including Coagulase-negative staphylococci (40.6%), Escherichia coli (15.6%), and Staphylococcus aureus (15.6%). Cultures with exclusive recovery in the anaerobic bottle were more frequently obtained ≤3 days after birth, compared to other cultures (31.3% vs 15.3%, P  = .03). When both bottles recovered the pathogen (n  = 113), the anaerobic bottle had a shorter time to positivity in 76 (67.3%) cultures. Conclusions Including anaerobic culture bottles could lead to the identification of pathogens not recovered in the aerobic bottle, as well as earlier identification of pathogens. [ABSTRACT FROM AUTHOR]

Background: Acetogens, a diverse group of anaerobic autotrophic bacteria, are promising whole-cell biocatalysts that fix CO2 during their growth. However, because of energetic constraints, acetogens exhibit slow growth and the product spectrum is often limited to acetate. Enabling acetogens to form more valuable products such as volatile fatty acids during autotrophic growth is imperative for cementing their place in the future carbon neutral industry. Co-cultivation of strains with different capabilities has the potential to ease the limiting energetic constraints. The lactate-mediated co-culture of an Acetobacterium woodii mutant strain, capable of lactate production, with the Clostridium drakei SL1 type strain can produce butyrate and hexanoate. In this study, the preceding co-culture is characterized by comparison of monocultures and different co-culture approaches. Results: C. drakei grew with H2 + CO2 as main carbon and energy source and thrived when further supplemented with D-lactate. Gas phase components and lactate were consumed in a mixotrophic manner with acetate and butyrate as main products and slight accumulation of hexanoate. Formate was periodically produced and eventually consumed by C. drakei. A lactate-mediated co-culture of the A. woodii [PbgaL_ldhD_NFP] strain, engineered for autotrophic lactate production, and C. drakei produced up to 4 ± 1.7 mM hexanoate and 18.5 ± 5.8 mM butyrate, quadrupling and doubling the respective titers compared to a non-lactate-mediated co-culture. Further co-cultivation experiments revealed the possible advantage of sequential co-culture over concurrent approaches, where both strains are inoculated simultaneously. Scanning electron microscopy of the strains revealed cell-to-cell contact between the co-culture partners. Finally, a combined pathway of A. woodii [PbgaL_ldhD_NFP] and C. drakei for chain-elongation with positive ATP yield is proposed. Conclusion: Lactate was proven to be a well-suited intermediate to combine the high gas uptake capabilities of A. woodii with the chain-elongation potential of C. drakei. The cell-to-cell contact observed here remains to be further characterized in its nature but hints towards diffusive processes being involved in the co-culture. Furthermore, the metabolic pathways involved are still speculatory for C. drakei and do not fully explain the consumption of formate while H2 + CO2 is available. This study exemplifies the potential of combining metabolically engineered and native bacterial strains in a synthetic co-culture. [ABSTRACT FROM AUTHOR]

Mechanistic investigation of host-microbe interactions in the human gut are hindered by difficulty of co-culturing microbes with intestinal epithelial cells. On one hand the gut bacteria are a mix of facultative, aerotolerant or obligate anaerobes, while the intestinal epithelium requires oxygen for growth and function. Thus, a coculture system that can recreate these contrasting oxygen requirements is critical step towards our understanding microbial-host interactions in the human gut. Here, we demonstrate Intestinal Organoid Physoxic Coculture (IOPC) system, a simple and cost-effective method for coculturing anaerobic intestinal bacteria with human intestinal organoids (HIOs). Using commensal anaerobes with varying degrees of oxygen tolerance, such as nano-aerobe Bacteroides thetaiotaomicron and strict anaerobe Blautia sp., we demonstrate that IOPC can successfully support 24–48 hours HIO-microbe coculture. The IOPC recapitulates the contrasting oxygen conditions across the intestinal epithelium seen in vivo. The IOPC cultured HIOs showed increased barrier integrity, and induced expression of immunomodulatory genes. A transcriptomic analysis suggests that HIOs from different donors show differences in the magnitude of their response to coculture with anaerobic bacteria. Thus, the IOPC system provides a robust coculture setup for investigating host-microbe interactions in complex, patient-derived intestinal tissues, that can facilitate the study of mechanisms underlying the role of the microbiome in health and disease. [ABSTRACT FROM AUTHOR]

Ischemic bowel disease is considered a high‐risk factor for infection from anaerobic bacteria, as the ischemic bowel is the perfect ground for their development. Herein, we present the case of an advance stage colon cancer patient with a rare cause of gastrointestinal bleeding and bacteremia due to Clostridium paraputrificum, a rare anaerobic Gram‐positive bacterium. The patient had presented with several episodes of hematochezia in the context of chronic superior mesenteric‐portal vein tumor thrombosis and rupture of ectopic varices, and the bacteremia was an unexpected complication of the bowel ischemia due to a combination of arterial ischemia and venous congestion. [ABSTRACT FROM AUTHOR]

Background: The combination of immune checkpoint inhibitors with radiotherapy can enhance the immunomodulation by RT and reduce the growth of distant unirradiated tumors (abscopal effect); however, the results are still not very satisfactory. Therefore, new treatment options are needed to enhance this effect. Our previous study showed that the combination of Bifidobacterium (Bi) and its specific monoclonal antibody (mAb) could target and alleviate hypoxia at the tumor site and act as a radiosensitizer. In this study, we explored the anti-tumor efficacy of quadruple therapy (Bi + mAb and RT + αPD-1). The current study also aimed to probe into the complex immune mechanisms underlying this phenomenon. Methods: Constructed 4T1 breast and CT26 colon cancer tumor models. A comprehensive picture of the impact of constructed quadruple therapy was provided by tumor volume measurements, survival analysis, PET/CT imaging, immune cell infiltration analysis and cytokine expression levels. Results: The abscopal effect was further amplified in the "cold" tumor model and prolonged survival in tumor-bearing mice. Bi can colonized in primary and secondary tumors and direct the mAb to reach the tumor site, activate complement, enhance the ADCC effect and initiate the innate immune response. Then combined with αPD-1 and radiotherapy to stimulate adaptive immune response and synergize with cytokines to expand the immune efficacy and generate effective anti-tumor immune response. Conclusions: Bi was used as an artificially implanted anaerobic target to cause a transient "infection" at the tumor, causing the tumor to become locally inflamed and "hot", and at the same time, mAb was used to target Bi to enhance the local immune effect of the tumor, and then combined with radiotherapy and αPD-1 to amplify the abscopal effect in multiple dimensions. Therefore, the present study provided a new idea for the multipotent immune-activating function of antibody-targeted anaerobic bacteria for the RT treatment of extensively metastasized cancer patients. [ABSTRACT FROM AUTHOR]

Background: Ruthenibacterium lactatiformans, a Gram-stain-negative, rod-shaped, obligate anaerobic bacterium of the Oscillospiraceae family, has not been previously reported in human infections. This study reports the first case of bacteraemia and potential vertebral osteomyelitis caused by Ruthenibacterium lactatiformans. Case presentation: An 82-year-old man with a history of diabetes, chronic renal failure, and prior spinal surgery for spondylolisthesis and spinal stenosis presented with fever and lower back pain. Magnetic resonance imaging revealed multiple vertebral osteomyelitis lesions. Initial blood cultures identified methicillin-resistant Staphylococcus aureus (MRSA), which prompted vancomycin treatment. However, repeated blood cultures not only confirmed persistent MRSA, but also detected Gram-negative bacilli (GNB). Despite surgical removal of the spinal hardware and antimicrobial therapy, the patient's osteomyelitis worsened, necessitating transfer for further management. Subsequent analysis using 16S rRNA gene sequencing identified the GNB as Ruthenibacterium lactatiformans. Conclusions: This is the first documented instance of human infection with Ruthenibacterium lactatiformans, signifying its pathogenic potential in vertebral osteomyelitis. The involvement of anaerobic bacteria and the possibility of polymicrobial infections complicate the diagnosis and treatment of vertebral osteomyelitis. This report underscores the need for caution when identifying the causative organism and selecting an appropriate treatment. [ABSTRACT FROM AUTHOR]

Pleural empyema can lead to significant morbidity and mortality despite chest drainage and antibiotic treatment, necessitating novel and minimally invasive interventions. Fusobacterium nucleatum is an obligate anaerobe found in the human oral and gut microbiota. Advances in sequencing and puncture techniques have made it common to detect anaerobic bacteria in empyema cases. In this report, we describe the case of a 65-year-old man with hypertension who presented with a left-sided encapsulated pleural effusion. Initial fluid analysis using metagenomic next-generation sequencing (mNGS) revealed the presence of Fusobacterium nucleatum and Aspergillus chevalieri. Unfortunately, the patient experienced worsening pleural effusion despite drainage and antimicrobial therapy. Ultimately, successful treatment was achieved through intrapleural metronidazole therapy in conjunction with systemic antibiotics. The present case showed that intrapleural antibiotic therapy is a promising measure for pleural empyema. [ABSTRACT FROM AUTHOR]

Co-aggregation of anaerobic microorganisms into suspended microbial biofilms (aggregates) serves ecological and biotechnological functions. Tightly packed aggregates of metabolically interdependent bacteria and archaea play key roles in cycling of carbon and nitrogen. Additionally, in biotechnological applications, such as wastewater treatment, microbial aggregates provide a complete metabolic network to convert complex organic material. Currently, experimental data explaining the mechanisms behind microbial co-aggregation in anoxic environments is scarce and scattered across the literature. To what extent does this process resemble co-aggregation in aerobic environments? Does the limited availability of terminal electron acceptors drive mutualistic microbial relationships, contrary to the commensal relationships observed in oxygen-rich environments? And do co-aggregating bacteria and archaea, which depend on each other to harvest the bare minimum Gibbs energy from energy-poor substrates, use similar cellular mechanisms as those used by pathogenic bacteria that form biofilms? Here, we provide an overview of the current understanding of why and how mixed anaerobic microbial communities co-aggregate and discuss potential future scientific advancements that could improve the study of anaerobic suspended aggregates. Key points: • Metabolic dependency promotes aggregation of anaerobic bacteria and archaea • Flagella, pili, and adhesins play a role in the formation of anaerobic aggregates • Cyclic di-GMP/AMP signaling may trigger the polysaccharides production in anaerobes [ABSTRACT FROM AUTHOR]

Rapeseed cake is an important agricultural waste and it has the potential to improve soil fertility, crop productivity and microbial activities. Nonetheless, the effects of rapeseed cake on microbes of tobacco rhizosphere have not studied yet. Therefore, this study was conducted to investigate the effects of rapeseed cake fertilizer on the inter-root soil microbial community of roasted tobacco. The present study was comprised of different proportions of nitrogen replacement fertilizers such as rapeseed cake fertilizer (N30:30%, N60:60%, N100:100%), and recommended nitrogen application as control. The results of diversity analysis showed that cake fertilizer significantly increased the Ace and Chao indices of soil microbial populations, and Shannon and Invsimpson indices were significantly higher. Furthermore, cake fertilizer also significantly increased the relative abundance of Actinobacteria, Ascomycetes, Intrasporangium, Chaetomium and Mortierella and decreased the relative abundance of Firmicutes, Basidiomycota and Fusicolla. Moreover, cake fertilizer also significantly increased the abundance of stress-tolerant bacteria and animal pathogen-dung saprotroph-endophyte- epiphyte-plant saprotroph-wood saprotroph fungi, and decreased the abundance of their potentially pathogenic and anaerobic bacteria and unknown saprophytic types and plant pathogenic fungi. Further, available phosphorus (AP), soil organic carbon (SOC), microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) were identified as the main factors affecting the structure of the inter-root soil microbial community of baked tobacco. In conclusion, rapeseed -cake based fertility could be an important strategy to modulate the composition of bacterial and fungal communities in tobacco rhizosphere by improving soil properties, and decreasing the abundance of pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Introduction: Fusobacterium nucleatum (F. nucleatum) is an anaerobic, gram-negative bacterium, morphologically an elongated bacillus with a sharp end belonging to the Bacteroidaceae. It is the normal flora of the mouth that is present in other organs in some diseases. Given the role of F. nucleatum in the creation and development of human diseases, it is very important to investigate its characteristics and functions. However, due to the obligate anaerobic nature of F. nucleatum, purification and long-term storage of the bacteria pose problems. The aim of this study is to find an optimal method for the purification of F. nucleatum to enable a detailed study of the functions and mechanisms of the bacteria to provide new therapeutic approaches to control or treat the diseases caused by F. nucleatum for future studies. Materials and Methods: Samples were taken from deep periodontal pockets of 16 patients using 40 size paper points with tryptic soy broth transfer medium (first method) and Columbia agar culture medium with gas pack type A and anaerobic jar (second method). The samples were then examined for the presence of F. nucleatum by macroscopic and microscopic observations, biochemical tests, PCR and sequencing. Results: The results showed that the tryptic soy broth transfer medium was not able to preserve and keep the bacteria alive, and the purified F. nucleatum was isolated by direct transfer to Columbia agar culture medium with gas pack type A and anaerobic jar. Discussion and Conclusion: Due to the obligate anaerobic nature of F. nucleatum, the use of transfer medium is not efficient for isolation due to the greater exposure of bacteria to air oxygen, and the optimal method for purification of F. nucleatum is the second sampling method. [ABSTRACT FROM AUTHOR]

Tattooing and use of permanent makeup (PMU) have dramatically increased over the last decade, with a concomitant increase in ink-related infections. Studies have shown evidence that commercial tattoo and PMU inks are frequently contaminated with pathogenic microorganisms. Considering that tattoo inks are placed into the dermal layer of the skin where anaerobic bacteria can thrive and cause infections in low-oxygen environments, the prevalence of anaerobic and aerobic bacteria should be assessed in tattoo and PMU inks. In this study, we tested 75 tattoo and PMU inks using the analytical methods described in the FDA Bacteriological Analytical Manual Chapter 23 for the detection of both aerobic and anaerobic bacterial contamination, followed by 16S rRNA gene sequencing for microbial identification. Of 75 ink samples, we found 26 contaminated samples with 34 bacterial isolates taxonomically classified into 14 genera and 22 species. Among the 34 bacterial isolates, 19 were identified as possibly pathogenic bacterial strains. Two species, namely Cutibacterium acnes (four strains) and Staphylococcus epidermidis (two strains) were isolated under anaerobic conditions. Two possibly pathogenic bacterial strains, Staphylococcus saprophyticus and C. acnes, were isolated together from the same ink samples (n = 2), indicating that tattoo and PMU inks can contain both aerobic (S. saprophyticus) and anaerobic bacteria (C. acnes). No significant association was found between sterility claims on the ink label and the absence of bacterial contamination. The results indicate that tattoo and PMU inks can also contain anaerobic bacteria. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microbial overlap in biowaste workers' exposure via air and species on hands. • Biowaste links to lactic acid bacteria and compost to A. fumigatus exposure. • Some species have previously been linked to occupational health issues. • Several risk class 2 species present; most species cannot be risk evaluated. • Different species compositions in various particle size fractions. This study aims to investigate the microbiological working environment of biowaste workers, focusing on airborne fungal and bacterial species exposure, size distribution, and species on workers' hands. The research, conducted across six plants with 45 personal exposure assessments, revealed a total of 150 bacterial species and 47 fungal species on workers' hands, including 19 and 9 species classified in risk class 2 (RC2), respectively. Workers' exposure analysis identified 172 bacterial and 32 fungal species, with several in RC2. In work areas, 55 anaerobic bacterial species belonging to RC2 were found. Different species compositions were observed in various particle size fractions, with the highest species richness for anaerobic bacteria in the fraction potentially depositing in the secondary bronchi and for fungi in the pharynx fraction. The geometric mean aerodynamic diameter (D G) of RC2 anaerobic bacteria was 3.9 µm, <1.6 µm for Streptomyces , 3.4 µm for Aspergillus , and 2.0 µm for Penicillium. Overlapping species were identified on workers' hands, in their exposure, and in work areas, with Bacillus amyloliquefaciens, Leuconostoc mesenteroides, Bacillus cereus, Enterococcus casseliflavus , and Aspergillus niger consistently present. While the majority of RC2 bacterial species lacked documented associations with occupational health problems, certain bacteria and fungi, including Bacillus cereus, Escherichia coli, Enterobacter, Klebsiella pneumonia, Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, Lichtheimia corymbifera, Lichtheimia ramosa, and Paecilomyces variotii, have previously been linked to occupational health issues. In conclusion, biowaste workers were exposed to a wide range of microorganisms including RC2 species which would deposit in different parts of the airways. [ABSTRACT FROM AUTHOR]