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Abstract Background Hypoxia is a frequent characteristic observed in solid tumors and is strongly associated with tumor metastasis, angiogenesis, and drug resistance. While the vasculature of hypoxic tumor tissues poses obstacles to the efficient administration of conventional drugs, it may prove advantageous in sustaining hyperthermia. Photothermal therapy (PTT) offers a promising treatment strategy that utilizes the activation of photosensitizers to produce heat, thus facilitating the selective ablation of tumor tissues. Method To enhance the accumulation of photothermal agents in tumor tissue and improve the effectiveness of PTT, we developed a self-propelled hybrid called Bif@PAu-NPs. This hybrid consists of polydopamine (PDA)-coated gold nanoparticles (Au-NPs) loaded onto the anaerobic Bifidobacterium infantis (Bif). Results The Bif@PAu-NPs actively aggregated at the tumor site because the ability of Bif can target hypoxic regions, and PAu-NPs achieved precise PTT due to their high photothermal conversion efficiency (η = 67.8%). The tumor tissues were ablated by PTT, resulting in the release of antigens through immunogenic cell death (ICD), which stimulates an immune response. The inclusion of GM-CSF enhanced the immune response by recruiting dendritic cells and initiating long-term anti-tumor immunity. Conclusion The Bif@PAu-NPs hybrid effectively suppressed the growth of both primary tumors and re-challenged tumors. The utilization Bif@PAu-NPs in conjunction with GM-SCF exhibits great potential as a photothermal-immunotherapeutic strategy for precisely treating solid tumors. Graphical Abstract In this study, the bacterial Bif@PAu-NPs biohybrid is exploited the self-driving ability of anaerobic Bifidobacterium infantis to deliver polydopamine-modified gold nanoparticles to hypoxic region of tumor. Under irradiation with 808 nm NIR laser, the hybrid exerts precise photothermal therapy to stimulate the immune response, which is further enhanced by GM-CSF, leading to recruitment of dendritic cells and initiation of a long-term anti-tumor immunity remember to prevent tumor recurrence.

Abstract Background Anaerobes are normal flora of the human body. However, they can cause serious infections in humans. Anaerobic bacteria are known to cause respiratory infections like pneumonia and acute exacerbation of chronic lower airway infections. These are often missed due to the complexity of their isolation and identification. Hence, this study aimed to study anaerobes causing respiratory tract infections and determine their antibiotic susceptibility. Materials & methods Clinical specimens such as bronchial aspirates and pleural aspirates collected from patients with respiratory diseases attending Vallabhbhai Patel Chest Institute were processed, the anaerobes isolated were identified, and their susceptibilities to various groups of antimicrobials were studied using standard microbiological methods. Results Three hundred and fourteen patients were included in the study, 154 males and 160 females. Of these 314 patients, 148 (47%) yielded anaerobes in their clinical samples. Seventy patients had more than one type of anaerobic organism. Hence, 235 isolates were recovered belonging to as many as 17 genera. The MIC of seven antibiotics on 154 isolates was tested. The isolates belonged mostly to the genera Bacteroides, Prevotella, Veillonella, and Actinomyces. Variable resistance was observed to most classes of antibiotics by many genera. Conclusions Metronidazole is commonly used against anaerobes, but the study showed that the isolates were 20–30% resistant to the antibiotic. Starting this as an empirical therapy might lead to treatment failure.

This report describes a rare instance of Odoribacter splanchnicus bacteremia secondary to acute appendicitis in a young man. Initially presenting with symptoms typical of appendicitis, he was diagnosed through clinical examination, laboratory tests, and computed tomography imaging, which confirmed an inflamed appendix with sealed perforation and abscess. O. splanchnicus , a Gram-negative anaerobe commonly found in the human gut, was identified as the causative agent through blood culture. The patient underwent successful laparoscopic appendectomy and was treated with intravenous amoxicillin–clavulanate, leading to a full recovery. This case highlights the potential of O. splanchnicus to act as an opportunistic pathogen in the context of intra-abdominal inflammation. It underscores the diagnostic challenges posed by O. splanchnicus , and the efficacy of advanced diagnostic tools like matrix-assisted laser desorption/ionization-time of flight mass spectrometry in identifying such rare infections. [ABSTRACT FROM AUTHOR]

The relative abundances of Bacteroidetes and Fusobacteria phyla have been reported to be decreased in dogs with chronic enteropathies. In colitis, obligate anaerobes (e.g., Bacteroides and Fusobacterium) are likely to vanish in response to the heightened oxidative stress in the colon’s inflammatory environment. The ability to adhere to the colonic mucosa is viewed as an essential step for obligate anaerobic bacteria to colonize and subsequently interact with the host’s epithelium and immune system. The reintroduction of a balanced community of obligate anaerobic bacteria using probiotics can restore the microbial function in the intestine. We found no studies on dogs regarding the adhesion properties of Bacteriodes vulgatus and Fusobacterium varium on paraffin-embedded canine colonic mucosa. Thus, the objective of this study is to investigate the adhesion capacities of these two bacterial species to paraffin-embedded colonic mucosa from healthy dogs. Additionally, we investigated their hydrophobicity properties to determine whether differences in adhesion capability can be explained by this factor. The results of our study showed that B. vulgatus adhered significantly lower than F. varium to the canine colonic mucosa (p = 0.002); however, B. vulgatus showed higher hydrophobicity (46.1%) than F. varium (12.6%). In conclusion, both bacteria have potential as probiotics, but further studies will be required to determine the efficacy and safety of the strains to be used, which strains to use, and the reasons other than hydrophobicity for attachment.

BackgroundPeriodontal disease (PD) is a prevalent oral affliction in canines, with limited therapeutic options available. The potential transmission of oral bacteria from canines to humans through inter-species contact poses a risk of zoonotic infection. Epigallocatechin gallate (EGCG), the principal catechin in green tea polyphenols, exhibits antibacterial properties effective against human PD. Given the clinical parallels between canine and human PD, this study explores the feasibility of employing EGCG as a therapeutic agent for canine PD.Methods and resultsInitially, a survey and statistical analysis of bacterial infection data related to canine PD in China were conducted. Subsequently, the primary pathogenic bacteria of canine PD were isolated and cultivated, and the in vitro antibacterial efficacy of EGCG was assessed. Furthermore, verify the therapeutic effect of EGCG on a mouse PD model in vivo. The high-throughput 16S rRNA gene sequencing identified Porphyromonas, Fusobacterium, Treponema, Moraxella, and Capnocytophaga as the genera that distinguishing PD from healthy canines’ gingival crevicular fluid (GCF) samples in China. The anaerobic culture and drug susceptibility testing isolated a total of 92 clinical strains, representing 22 species, from 72 canine GCF samples, including Porphyromonas gulae, Prevotella intermedia, Porphyromonas macacae, etc. The minimum inhibitory concentration (MIC) ranging of EGCG was from 0.019 to 1.25 mg/mL. Following a 7 days oral mucosal administration of medium-dose EGCG (0.625 mg/mL), the abundance of periodontal microorganisms in PD mice significantly decreased. This intervention ameliorated alveolar bone loss, reducing the average cementoenamel junction to the alveolar bone crest (CEJ-ABC) distance from 0.306 mm ± 0.050 mm to 0.161 mm ± 0.026 mm. Additionally, EGCG (0.3125 mg/mL) markedly down-regulated the expression of inflammatory factor IL-6 in the serum of PD mice.ConclusionOur research demonstrates the significant antibacterial effects of EGCG against the prevalent bacterium P. gulae in canine PD. Moreover, EGCG exhibits anti-inflammatory properties and proves effective in addressing bone loss in a PD mouse model. These findings collectively suggest the therapeutic potential of EGCG in the treatment of canine PD. The outcomes of this study contribute valuable data, laying the foundation for further exploration and screening of alternative antibiotic drugs to advance the management of canine PD.

The non-filarial and non-communicable disease podoconiosis affects around 4 million people and is characterized by severe leg lymphedema accompanied with painful intermittent acute inflammatory episodes, called acute dermatolymphangioadenitis (ADLA) attacks. Risk factors have been associated with the disease but the mechanisms of pathophysiology remain uncertain. Lymphedema can lead to skin lesions, which can serve as entry points for bacteria that may cause ADLA attacks leading to progression of the lymphedema. However, the microbiome of the skin of affected legs from podoconiosis individuals remains unclear. Thus, we analysed the skin microbiome of podoconiosis legs using next generation sequencing. We revealed a positive correlation between increasing lymphedema severity and non-commensal anaerobic bacteria, especially Anaerococcus provencensis, as well as a negative correlation with the presence of Corynebacterium, a constituent of normal skin flora. Disease symptoms were generally linked to higher microbial diversity and richness, which deviated from the normal composition of the skin. These findings show an association of distinct bacterial taxa with lymphedema stages, highlighting the important role of bacteria for the pathogenesis of podoconiosis and might enable a selection of better treatment regimens to manage ADLA attacks and disease progression. [ABSTRACT FROM AUTHOR]

Introduction: Healthy lung microbiota plays an important role in preventing Mycobacterium tuberculosis (Mtb) infections by activating immune cells and stimulating production of T-helper cell type 1 cytokines. The dynamic stability of lung microbiota relies mostly on lung homeostasis. In our previous studies, we found that Mtb virulence factor, Rv1987 protein, can mediate host immune response and enhance mycobacterial survival in host lung. However, the alteration of lung microbiota and the contribution of lung microbiota dysbiosis to mycobacterial evasion in this process are not clear so far. Methods: M. smegmatis which does not contain the ortholog of Rv1987 protein was selected as a model strain to study the effects of Rv1987 on host lung microbiota. The lung microbiota, immune state and metabolites of mice infected by M. smegmatis overexpressing Rv1987 protein (MS1987) were detected and analyzed. Results: The results showed that Rv1987 inhibited inflammatory response in mouse lung and anaerobic bacteria and Proteobacteria, Bacteroidota, Actinobacteriota and Acidobacteriota bacteria were enriched in the lung tissues correspondingly. The immune alterations and microbiota dysbiosis affected host metabolic profiles, and some of significantly altered bacteria in MS1987-infected mouse lung, such as Delftia acidovorans, Ralstonia pickettii and Escherichia coli, led to anti-inflammatory responses in mouse lung. The secretory metabolites of these altered bacteria also influenced mycobacterial growth and biofilm formation directly. Conclusion: All these results suggested that Rv1987 can attenuate inflammatory response and alter microbiota in the lung, which in turn facilitates mycobacterial survival in the host. [ABSTRACT FROM AUTHOR]

Introduction: Chain elongation technology, which involves fermentation with anaerobic bacteria, has gained attention for converting short and medium chain substrates into valuable and longer-chain products like medium chain fatty acids (MCFAs). In the recent past, the focus of studies with pure chain elongating cultures was on species of other genera, mainly Clostridium kluyveri. Recently, other chain elongators have been isolated that deserve further research, such as Megasphaera hexanoica. Methods: In this study, batch studies were performed in bottles with two different media to establish the optimal conditions for growth of M. hexanoica: (a) a medium rich in different sources of nitrogen and (b) a medium whose only source of nitrogen is yeast extract. Also, batch bioreactor studies at pH values of 5.8, 6.5 and 7.2 were set up to study the fermentation of lactate (i.e., electron donor) and acetate (i.e., electron acceptor) by M. hexanoica. Results and discussion: Batch bottle studies revealed the yeast extract (YE) containing medium as the most promising in terms of production/cost ratio, producing n-caproate rapidly up to 2.62 ± 0.24 g/L. Subsequent bioreactor experiments at pH 5.8, 6.5, and 7.2 confirmed consistent production profiles, yielding C4-C8 fatty acids. A fourth bioreactor experiment at pH 6.5 and doubling both lactate and acetate concentrations enhanced MCFA production, resulting in 3.7 g/L n-caproate and 1.5 g/L n-caprylate. H2 and CO2 production was observed in all fermentations, being especially high under the increased substrate conditions. Overall, this study provides insights into M. hexanoica's behavior in lactate-based chain elongation and highlights optimization potential for improved productivity. [ABSTRACT FROM AUTHOR]

Oxidation of phosphite (HPO3 2-) to phosphate (HPO4 2-) releases electrons at a very low redox potential (E0 '= -690 mV) which renders phosphite an excellent electron donor for microbial energy metabolism. To date, two pure cultures of strictly anaerobic bacteria have been isolated that run their energy metabolism on the basis of phosphite oxidation, the Gram-negative Desulfotignum phosphitoxidans (DSM 13687) and the Gram-positive Phosphitispora fastidiosa (DSM 112739). Here, we describe the key enzyme for dissimilatory phosphite oxidation in these bacteria. The enzyme catalyzed phosphite oxidation in the presence of adenosine monophosphate (AMP) to form adenosine diphosphate (ADP), with concomitant reduction of oxidized nicotinamide adenine dinucleotide (NAD+) to reduced nicotinamide adenine dinucleotide (NADH). The enzyme of P. fastidiosa was heterologously expressed in Escherichia coli. It has a molecular mass of 35.2 kDa and a high affinity for phosphite and NAD+. Its activity was enhanced more than 100-fold by addition of ADP-consuming adenylate kinase (myokinase) to a maximal activity between 30 and 80 mU x mg protein-1. A similar NAD-dependent enzyme oxidizing phosphite to phosphate with concomitant phosphorylation of AMP to ADP is found in D. phosphitoxidans, but this enzyme could not be heterologously expressed. Based on sequence analysis, these phosphite-oxidizing enzymes are related to nucleotide-diphosphate-sugar epimerases and indeed represent AMP-dependent phosphite dehydrogenases (ApdA). A reaction mechanism is proposed for this unusual type of substrate-level phosphorylation reaction. [ABSTRACT FROM AUTHOR]

Using phages as salvage therapy for nonhealing infections is gaining recognition as a viable solution for patients with such infections. The escalating issue of antibiotic resistance further emphasizes the significance of using phages in treating bacterial infections, encompassing compassionate-use scenarios and clinical trials. Given the high specificity of phages, selecting the suitable phage(s) targeting the causative bacteria becomes critical for achieving treatment success. However, in contrast to conventional antibiotics, where susceptibility-testing procedures were well established for phage therapy, there is a lack of standard frameworks for matching phages from a panel to target bacterial strains and assessing their interactions with antibiotics or other agents. This review discusses and compares published methods for clinical phage microbiology, also known as phage susceptibility testing, and proposes guidelines for establishing a standard pipeline based on our findings over the past 5 years of phage therapy at the Israeli Phage Therapy Center. [ABSTRACT FROM AUTHOR]

Candida albicans is frequently identified as a colonizer of the oral cavity in health and has recently been termed a "keystone" commensal due to its role on the bacterial communities. However, the role that C. albicans plays in such interactions is not fully understood. Therefore, this study aimed to identify the relationship between C. albicans and bacteria associated with oral symbiosis and dysbiosis. To do this, we evaluated the ability of C. albicans to support the growth of the aerobic commensal Streptococcus gordonii and the anaerobic pathogens Fusobacterium nucleatum and Porphyromonas gingivalis in the biofilm environment. RNA‐Sequencing with the Illumina platform was then utilized to identify C. albicans gene expression and functional pathways involved during such interactions in dual‐species and a 4‐species biofilm model. Results indicated that C. albicans was capable of supporting growth of all three bacteria, with a significant increase in colony counts of each bacteria in the dual‐species biofilm (p < 0.05). We identified specific functional enrichment of pathways in our 4‐species community as well as transcriptional profiles unique to the F. nucleatum and S. gordonii dual‐species biofilms, indicating a species‐specific effect on C. albicans. Candida‐related hemin acquisition and heat shock protein mediated processes were unique to the organism following co‐culture with anaerobic and aerobic bacteria, respectively, suggestive that such pathways may be feasible options for therapeutic targeting to interfere with these fungal‐bacterial interactions. Targeted antifungal therapy may be considered as an option for biofilm destabilization and treatment of complex communities. Moving forward, we propose that further studies must continue to investigate the role of this fungal organism in the context of the interkingdom nature of oral diseases. [ABSTRACT FROM AUTHOR]

Phosphite is a stable phosphorus compound that, together with phosphate, made up a substantial part of the total phosphorus content of the prebiotic Earth's crust. Oxidation of phosphite to phosphate releases electrons at an unusually low redox potential (−690 mV at pH 7.0). Numerous aerobic and anaerobic bacteria use phosphite as a phosphorus source and oxidise it to phosphate for synthesis of nucleotides and other phosphorus‐containing cell constituents. Only two pure cultures of strictly anaerobic bacteria have been isolated so far that use phosphite as an electron donor in their energy metabolism, the Gram‐positive Phosphitispora fastidiosa and the Gram‐negative Desulfotignum phosphitoxidans. The key enzyme of this metabolism is an NAD+‐dependent phosphite dehydrogenase enzyme that phosphorylates AMP to ADP. These phosphorylating phosphite dehydrogenases were found to be related to nucleoside diphosphate sugar epimerases. The produced NADH is channelled into autotrophic CO2 fixation via the Wood‐Ljungdahl (CO‐DH) pathway, thus allowing for nearly complete assimilation of the substrate electrons into bacterial biomass. This extremely efficient type of electron flow connects energy and carbon metabolism directly through NADH and might have been important in the early evolution of life when phosphite was easily available on Earth. [ABSTRACT FROM AUTHOR]

Hypervirulent ribotypes (HVRTs) of Clostridioides difficile such as ribotype (RT) 027 are epidemiologically important. This study evaluated whether MALDI-TOF can distinguish between strains of HVRTs and non-HVRTs commonly found in Europe. Obtained spectra of clinical C. difficile isolates (training set, 157 isolates) covering epidemiologically relevant HVRTs and non-HVRTs found in Europe were used as an input for different machine learning (ML) models. Another 83 isolates were used as a validation set. Direct comparison of MALDI-TOF spectra obtained from HVRTs and non-HVRTs did not allow to discriminate between these two groups, while using these spectra with certain ML models could differentiate HVRTs from non-HVRTs with an accuracy >95% and allowed for a sub-clustering of three HVRT subgroups (RT027/RT176, RT023, RT045/078/126/127). MALDI-TOF combined with ML represents a reliable tool for rapid identification of major European HVRTs. [ABSTRACT FROM AUTHOR]

The Gram-positive anaerobic bacterium Clostridioides difficile (CD) can produce intense exotoxins, contributing to nosocomial infections, and it is the most common cause of health-care-associated infectious diarrhea. Based on spontaneous Individual Case Safety Reports from EudraVigilance (EV), we conducted a descriptive analysis of Clostridioides difficile infection (CDI) cases that reported a spontaneous adverse reaction related to using ceftriaxone, colistimethate, ciprofloxacin, gentamicin, linezolid, meropenem, and piperacillin/tazobactam. Most ADR reports registered in EV that were related to CDI were associated with ceftriaxone (33%), ciprofloxacin (28%), and piperacillin/tazobactam (21%). Additionally, the disproportionality analysis performed showed that all studied antibiotics had a lower reporting probability when compared to clindamycin. A causal relationship between a drug and the occurrence of an adverse reaction cannot be established from EV data alone because the phenomena of underreporting, overreporting, and reporting bias may affect the results. Based on the analysis of the collected data, this study underlines the importance of surveillance and monitoring programs for the consumption of antibiotics. Furthermore, it is essential to use standardized laboratory tests to define CDI's nature accurately. To prevent this infection, specialists should collaborate and adhere strictly to antibiotic stewardship programs, hygiene practices, and isolation protocols. [ABSTRACT FROM AUTHOR]

An overwhelming number of studies have reported the correlation of decreased abundance of butyrate-producing commensals with a wide range of diseases. However, the molecular-level mechanisms whereby gut butyrate causally affects the host mucosal immunity and pathogenesis were poorly understood, hindered by the lack of efficient tools to control intestinal butyrate. Here we engineered a facultative anaerobic commensal bacterium to delivery butyrate at the intestinal mucosal surface, and implemented it to dissect the causal role of gut butyrate in regulating host intestinal homeostasis in a model of murine chronic colitis. Mechanistically, we show that gut butyrate protected against colitis and preserved intestinal mucosal homeostasis through its inhibiting effect on the key pyroptosis executioner gasdermin D (GSDMD) of colonic epithelium, via functioning as an HDAC3 inhibitor. Overall, our work presents a new avenue to build synthetic living delivery bacteria to decode causal molecules at the host-microbe interface with molecular-level insights. • Microbiota-derived metabolite butyrate has intimate correlation with diseases. • A probiotic was engineered to delivery butyrate at the intestinal mucosal surface. • Causal role of gut butyrate in regulating host intestinal homeostasis was dissected. [ABSTRACT FROM AUTHOR]

Bacterial vaginosis (BV) is a most common microbiological syndrome. Multiplex next-generation sequencing (NGS) or molecular tests allow a complete and accurate vaginal microbiota profiling in order to determine the primary causative agent. Due to the high costs and limited availability of NGS, the multiplex real-time PCR draws more attention. The present study aimed to evaluate the microbial composition and dominant lactobacilli species in non-pregnant women with bacterial vaginosis using a multiplex RT-PCR test and determine its diagnostic significance. In total, 331 women complaining of vaginal discharge were included. BV was confirmed upon clinical examination and Nugent criteria. A real-time PCR test was carried out with a new Femoflor test, which identifies opportunistic bacteria, STD pathogens, and some viruses. According to the results, the rate of lactobacilli is significantly reduced in BV-affected patients when compared to healthy women. Moreover, the rate of L. crispatus significantly decreases, while the rate of L. iners remains high. Among obligate anaerobic bacteria, Gardnerella vaginalis was the most prevalent in women with BV. The Femoflor test demonstrated high sensitivity and specificity for diagnosing BV. Moreover, the test allows the identification of infection in women with intermediate vaginal microbiota, as well as STD pathogens, and viruses. Thus, the application of real-time PCR tests can be effectively used in vaginal microbiota evaluation in women with BV, intermediate vaginal microbiota, and healthy women. In addition, this test may be used as an alternative to the Amsel criteria and Nugent scoring method in diagnosing BV. [ABSTRACT FROM AUTHOR]

A phytochemical investigation on the ethanol extract from the fruiting bodies of Ganoderma tsugae resulted in the isolation of two undescribed lanostane triterpenoids, lanosta-8,24E-dien-3,7,11-trioxo-26,27-dihydroxy (1) and 22,23,24,25,26,27-hexanorlanosta-7,9(11)-dien-3β-acetyloxy-15-hydroxy-20-oxo (2). Their structures were determined by spectral methods such as 1D and 2D (1H–1H COSY, HMQC, NOESY, and HMBC) NMR spectroscopy, in addition to high-resolution mass spectrometry. The in vitro pharmacological studies revealed 2 possessed antibacterial activity against 5 anaerobic bacteria with MIC values less than 30 μg/mL. [ABSTRACT FROM AUTHOR]

This article discusses a case study of a rare infection called pyopneumothorax, which was caused by a coinfection of two bacteria, Parvimonas micra and Prevotella oralis. These bacteria are commonly found in the mouth and gut and are associated with gum disease. In people with weakened immune systems, they can cause infections in other parts of the body. The study highlights the difficulties in identifying these bacteria due to their unusual symptoms and challenges in growing them in a lab. The use of advanced sequencing technology can be helpful in diagnosing and treating these infections. The article also explores the use of this technology in diagnosing anaerobic infections, specifically focusing on Prevotella oralis. This bacterium is resistant to certain antibiotics but sensitive to carbapenem antibiotics. Anaerobic infections often involve multiple bacteria, and anaerobes may be present in up to 76% of cases. The article presents a case study where sequencing technology was used to diagnose an anaerobic infection and guide treatment. The study acknowledges its limitations and concludes that accurately identifying the bacteria causing the infection is crucial in treating anaerobic infections, and sequencing technology can provide a fast and accurate diagnosis when traditional lab methods fail to match the clinical symptoms. [Extracted from the article]

Phloroglucinol (1,3,5-trihydroxybenzene) is an important intermediate in the degradation of flavonoids and tannins by anaerobic bacteria. Recent studies have shed light on the enzymatic mechanism of phloroglucinol degradation in butyrate-forming anaerobic bacteria, including environmental and intestinal bacteria such as Clostridium and Flavonifractor sp. Phloroglucinol degradation gene clusters have also been identified in other metabolically diverse bacteria, although the polyphenol metabolism of these micro-organisms remain largely unexplored. Here, we describe biochemical studies of polyphenol degradation enzymes found in the purple non-sulfur bacterium Rubrivivax gelatinosus IL144, an anaerobic photoheterotroph reported to utilize diverse organic compounds as carbon sources for growth. In addition to the phloroglucinol reductase and dihydrophloroglucinol cyclohydrolase that catalyze phloroglucinol degradation, we characterize a Mn2+ - dependent phloretin hydrolase that catalyzes the cleavage of phloretin into phloroglucinol and phloretic acid. We also report a Mn2+ -dependent decarboxylase (DeC) that catalyzes the reversible decarboxylation of 2,4,6-trihydroxybenzoate to form phloroglucinol. A bioinformatics search led to the identification of DeC homologs in diverse soil and gut bacteria, and biochemical studies of a DeC homolog from the human gut bacterium Flavonifractor plautii demonstrated that it is also a 2,4,6-trihydroxybenzoate decarboxylase. Our study expands the range of enzymatic mechanisms for phloroglucinol formation, and provides further biochemical insight into polyphenol metabolism in the anaerobic biosphere. [ABSTRACT FROM AUTHOR]

Background: Antibiotic beads are used to treat local bacterial infections by delivering high drug concentrations to infected tissue. Objectives: This study examined the elution characteristics of metronidazole from metronidazole-calcium sulfate (MCa) and metronidazole-calcium-potassium sulfate (MCaK) beads over 20 days and the antibacterial efficacy of the beads after storage. Methods: The MCa and MCaK beads were prepared by mixing 250 mg of metronidazole and 10 g of calcium sulfate hemihydrate with water and a 3% potassium sulfate solution, respectively. The beads were placed in phosphate-buffered saline for the elution study. The metronidazole eluents were determined using high-performance liquid chromatography. The microstructures were examined by scanning electron microscopy (SEM), and the antimicrobial activity was evaluated by a microbioassay. Results: For the 20-day study, the total amount of metronidazole released was greater in the MCa beads than in the MCaK beads by 6.61 ± 0.48 mg (89.11% ± 3.04%) and 4.65 ± 0.36 mg (73.11% ± 4.38%), respectively. The amounts of eluted drugs from the MCa and MCaK beads were higher than the minimum inhibitory concentration at 0.5 µg/mL against anaerobic bacteria at both 20 days and 14 days. SEM showed that calcium crystals on the outer surface had dissolved after elution, and thinner calcium crystals were prominent in the MCaK beads. The MCa and MCaK beads exhibited antibacterial activity after setting, followed by storage at room temperature or 4°C for 21 days. Conclusions: The MCa beads could release more drug than the MCaK beads, but all eluted metronidazole amounts were effective in controlling bacterial infections. Both metronidazole beads could be stored at ambient temperature or in a refrigerator. [ABSTRACT FROM AUTHOR]

(Background) The diagnosis and the antimicrobial treatment of orthopedic infection are challenging, especially in cases with culture-negative results. New molecular methods, such as next-generation sequencing (NGS), promise to overcome some limitations of the standard culture, such as the detection of difficult-to-grow bacteria. However, data are scarce regarding the impact of molecular techniques in real-life scenarios. (Methods) We included cases of suspected orthopedic infection treated with surgery from May 2021 to September 2023. We combined traditional cultures with NGS. For NGS, we performed a metagenomic analysis of ribosomal 16s, and we queried dedicated taxonomic libraries to identify the species. To avoid false positive results, we set a cut-off of 1000 counts of the percentage of frequency of reads. (Results) We included 49 patients in our study. Our results show the presence of bacteria in 36/49 (73%) and 29/49 (59%) cases studied with NGS and traditional cultures, respectively. The concordance rate was 61%. Among the 19/49 discordant cases, in 11/19 cases, cultures were negative and NGS positive; in 4/19, cultures were positive and NGS negative; and in the remaining 4/19, different species were detected by traditional cultures and NGS. (Conclusions) Difficult-to-grow microorganisms, such as slow-growing anaerobic bacteria, were better detected by NGS compared to traditional culture in our study. However, more data to distinguish between true pathogens and contaminants are needed. NGS can be an additional tool to be used for the diagnosis of orthopedic infections and the choice of appropriate antimicrobial therapy. [ABSTRACT FROM AUTHOR]

Cutibacterium acnes (C. acnes) is a Gram-positive anaerobic facultative bacterium that is part of the human skin commensal microbiome. It colonizes various regions of the body, including the face, back, and chest. While typically a harmless commensal, under certain conditions, C. acnes can become pathogenic, leading to or promoting conditions such as acne vulgaris (AV), post-surgical infections, prostate cancer, and sarcoidosis. Current treatments for C. acnes infections often involve antibiotics, but the rise of antibiotic resistance has raised concerns. This review presents the virulence factors, clinical relevance, and current treatments of C. acnes, highlighting its association with AV, post-surgical infections, and other diseases. It also explores alternative innovative therapies such as phage therapy in development/research that are gaining prominence, with a growing focus on personalized medical approaches. To enhance C. acnes treatment while minimizing side effects and antibiotic prescription concerns, numerous clinical studies have been undertaken. These investigations span various pathological profiles and employ diverse strategies, such as utilizing bacterial extracts and compounds to restore healthy skin flora. The limitations and challenges of current and innovative treatments are also addressed, emphasizing the need for multidisciplinary strategies to combat C. acnes infections effectively. [ABSTRACT FROM AUTHOR]

In order to study the differentiation of performance and functional bacteria of anaerobic ammonium oxidation (anammox) processes inoculated with different anammox sludge impaired by low temperature, two upflow anaerobic sludge bed reactors were constructed to treat synthetic nitrogen-contained wastewater. Experimental results showed that anammox sludge exposed to lower room temperature of 0–15 °C for nearly 1 month recovered anammox activity on Day 1 without sludge lysis, and the total nitrogen removal rate (TNRR) gradually increased from 3.23 to 13.41 kg m−3 d−1. Stover–Kincannon model predicted a maximum nitrogen removal potential (Umax) of 177.62 kg m−3 d−1. However, anammox sludge exposed to − 20 °C environment for nearly 30 days experienced three stages of sludge lysis (Days 1–2), sludge lag (Days 3–7) and propagation stage (Days 8–77). Due to the activity loss and FA inhibition, the maximum TNRR of 4.04 kg m−3 d−1 and a predicted Umax of 8.51 kg m−3 d−1 were observed after 77 days' operation. After long-term operation (291 d), the dominant functional bacteria and genes were changed; even two reactors had similar operation performance. Anammox genus Candidatus Jettenia had the maximum RA values of 16.01% with higher nitrogen removal-related genes nirB/K/S, hdh and hzo in reactor feeding sludge exposed to 0–15 °C, but Candidatus Brocadia was dominant with higher hzs gene in reactor inoculating sludge suffering from − 20 °C environment. This work would be helpful to restart the anammox reactor with seeding sludge after long-term storage of anammox sludge under lower temperature conditions. [ABSTRACT FROM AUTHOR]

Bacillus cereus is a Gram positive, facultative anaerobic bacterium characterized by large rod- shaped cells and an ability to form heat-resistant endospores. Because this bacterium is so widely distributed throughout nature and is frequently found in soil, it is naturally present in a wide variety of food products of both animal and plant origin. The presence of B. cereus and its virulence factors in dairy products may result in food poisoning and other illnesses. B. cereus causes two types of intestinal illness: emetic (vomiting) and diarrheal. Furthermore, the bacterium causes a variety of systemic and local infections in both immunosuppressed and immunocompetent persons. Different toxins and pathogenic factors like nonhemolytic enterotoxin Nhe, hemolytic enterotoxin Hbl, enterotoxin FM and cytotoxin K are accountable for diarrheal syndrome, meanwhile the depsipeptide cereulide toxin causes emetic syndrome. Because of its genetic similarity to Bacillus anthracis and Bacillus thuringiensis, the ability to detect this pathogen in food is frequently difficult. We reviewed characters, virulent attributes, toxins profiles of this bacterium. Current control methods are limited so future control strategies must be developed. [ABSTRACT FROM AUTHOR]

Marine sediments act as a sink for the accumulation of various organic contaminants such as polychlorobiphenyls (PCBs). These contaminants affect the composition and activity of microbial communities, particularly favoring those capable of thriving from their biodegradation and biotransformation under favorable conditions. Hence, contaminated environments represent a valuable biological resource for the exploration and cultivation of microorganisms with bioremediation potential. In this study, we successfully cultivated microbial consortia with the capacity for PCB removal under both aerobic and anaerobic conditions. The source of these consortia was a multicontaminated marine sediment collected from the Mar Piccolo (Taranto, Italy), one of Europe's most heavily polluted sites. High-throughput sequencing was employed to investigate the dynamics of the bacterial community of the marine sediment sample, revealing distinct and divergent selection patterns depending on the imposed reductive or oxidative conditions. The aerobic incubation resulted in the rapid selection of bacteria specialized in oxidative pathways for hydrocarbon transformation, leading to the isolation of Marinobacter salinus and Rhodococcus cerastii species, also known for their involvement in aerobic polycyclic aromatic hydrocarbons (PAHs) transformation. On the other hand, anaerobic incubation facilitated the selection of dechlorinating species, including Dehalococcoides mccartyi, involved in PCB reduction. This study significantly contributes to our understanding of the diversity, dynamics, and adaptation of the bacterial community in the hydrocarbon-contaminated marine sediment from one sampling point of the Mar Piccolo basin, particularly in response to stressful conditions. Furthermore, the establishment of consortia with biodegradation and biotransformation capabilities represents a substantial advancement in addressing the challenge of restoring polluted sites, including marine sediments, thus contributing to expanding the toolkit for effective bioremediation strategies. [ABSTRACT FROM AUTHOR]

Residents of the Qinghai-Tibet Plateau might experience shifts in their gut microbiota composition as a result of the plateau environment. For example, high altitudes can increase the abundance of obligate anaerobic bacteria, decrease the number of aerobic bacteria and facultative anaerobic bacteria, increase probiotics, and decrease pathogenic bacteria. This study aimed to determine the structure and metabolic differences in intestinal microbial communities among the Tibetan and Han populations on the Qinghai-Xizang Plateau and shed light on the factors that influence the abundance of the microbial communities in the gut. The structural characteristics of intestinal microorganisms were detected from blood and fecal samples using 16S rRNA sequencing. Metabolic characteristics were detected using gas chromatography–time-of-flight mass spectrometry (GC–TOFMS). The influencing factors were analyzed using Spearman's correlation analysis. Bacteroides and Bifidobacterium were dominant in the intestinal tract of the Han population, while Bacteroides and Prevotella were dominant in that of the Tibetan population, with marked differences in Pseudomonas, Prevotella, and other genera. Ferulic acid and 4-methylcatechol were the main differential metabolites between the Tibetan and Han ethnic groups. This may be the reason for the different adaptability of Tibetan and Han nationalities to the plateau. Alanine aminotransferase and uric acid also have a high correlation with different bacteria and metabolites, which may play a role. These results reveal notable disparities in the compositions and metabolic characteristics of gut microbial communities in the Tibetan and Han people residing on the Qinghai-Tibet Plateau and may provide insights regarding the mechanism of plateau adaptability. [ABSTRACT FROM AUTHOR]

Identifying the microbiome within chronic diabetic foot ulcers is essential if effective antimicrobial therapies are to be administered. Using culture and 16S rRNA gene sequencing, the aim of this study was to compare the microbiome of paired tissue scraping samples with swab samples, collected from participants during attendance at a high‐risk foot clinic. The mean richness of cultured swab and tissue scraping samples was consistent, with anaerobes infrequently isolated from both sample types. Comparing percentage frequencies of detection of selected genera of known and potential pathogens namely Staphylococcus, Streptococcus, Enterococcus, Corynebacterium, Enterobacteriaceae and Pseudomonas from cultured and sequenced swab and tissue scrapings indicated that both collection methods captured varying percentages of all the selected genera. The mean abundance of sequenced samples was not significantly different between swabs and tissue scrapings. The mean richness or number of distinct operational taxonomic units (OTUs) and Shannon's H diversity index were not significantly different between the two collection methods. The mean relative abundance of the selected genera of known and potential pathogens, including anaerobes Anaerococcus and Finegoldia, was higher in swabs compared with tissue scrapings and significantly so in Staphylococcus and Pseudomonas genera. Multivariate analyses confirmed no significant differences between the bacterial community compositions of the paired samples. These results suggest that tissue scrapings and swabs can effectively capture the microbiome of chronic DFUs using culture and 16S rRNA gene sequencing. [ABSTRACT FROM AUTHOR]

Background: Traditionally, conventional microbiological culture methods have been used to detect pathogenic microorganisms in chronic osteomyelitis. However, these methods have been found to have a low detection rate, complicating the precise guidance of infection treatment. This study employed metagenomic next-generation sequencing (mNGS) to detect these microorganisms in chronic osteomyelitis with three main objectives: 1). Gain a deeper understanding of the composition of pathogenic microorganisms in chronic osteomyelitis. 2). Compare the microbial detection rates between mNGS and the standard culture methods used in laboratories to enhance the effectiveness of the traditional culture methods. 3). Explore the potential of mNGS in etiological diagnosis. Methods: Fifty clinically confirmed intraoperative bone tissue samples of chronic osteomyelitis from January 2021 to December 2021 were collected and subjected to mNGS and microbiological testing, respectively. The orthopaedic surgeon combined clinical manifestations and related examinations to determine the causative pathogens. Results: The culture method obtained 29 aerobic and parthenogenic anaerobic bacteria, 3 specific anaerobic bacteria, and 1 yeast-like fungus. Thirty-six aerobic and parthenogenic anaerobic bacteria, 11 specific anaerobic bacteria, and 1 yeast-like fungus were obtained by mNGS, and 2 Mycobacterium tuberculosis(MTB) strains were detected. However, there was no significant difference in the overall positive detection rate between mNGS and the culture method (P = 0.07), and the two were not statistically significant in detecting aerobic and partly anaerobic bacteria (P = 0.625). But, mNGS was significantly superior to culture in detecting anaerobic bacteria and Mycobacterium tuberculosis (P<0.05). Conclusions: The mNGS method has enhanced our understanding of the distribution of pathogenic microorganisms in chronic osteomyelitis. Traditional culture methods help isolate and cultivate aerobic and facultative anaerobic bacteria, and fungi, and are also utilized for antibacterial drug sensitivity tests. However, mNGS has shown superior capabilities in detecting anaerobic bacteria, MTB, and mixed infection bacteria. This finding offers invaluable guidance for improving laboratory microbial culture and detection conditions. Hence, mNGS should be judiciously used for chronic osteomyelitis, and PCR can be implemented for certain difficult-to-culture microorganisms, such as MTB. [ABSTRACT FROM AUTHOR]

Background: Anaerobes are normal flora of the human body. However, they can cause serious infections in humans. Anaerobic bacteria are known to cause respiratory infections like pneumonia and acute exacerbation of chronic lower airway infections. These are often missed due to the complexity of their isolation and identification. Hence, this study aimed to study anaerobes causing respiratory tract infections and determine their antibiotic susceptibility. Materials & methods: Clinical specimens such as bronchial aspirates and pleural aspirates collected from patients with respiratory diseases attending Vallabhbhai Patel Chest Institute were processed, the anaerobes isolated were identified, and their susceptibilities to various groups of antimicrobials were studied using standard microbiological methods. Results: Three hundred and fourteen patients were included in the study, 154 males and 160 females. Of these 314 patients, 148 (47%) yielded anaerobes in their clinical samples. Seventy patients had more than one type of anaerobic organism. Hence, 235 isolates were recovered belonging to as many as 17 genera. The MIC of seven antibiotics on 154 isolates was tested. The isolates belonged mostly to the genera Bacteroides, Prevotella, Veillonella, and Actinomyces. Variable resistance was observed to most classes of antibiotics by many genera. Conclusions: Metronidazole is commonly used against anaerobes, but the study showed that the isolates were 20–30% resistant to the antibiotic. Starting this as an empirical therapy might lead to treatment failure. [ABSTRACT FROM AUTHOR]

Mesenchymal stromal cells, commonly referred to as MSCs, are a type of multipotent stem cells that are typically extracted from adipose tissue and bone marrow. In the field of tissue engineering and regenerative medicine, MSCs and their exosomes have emerged as revolutionary tools. Researchers are now devoting greater attention to MSCs because of their ability to generate skin cells like fibroblasts and keratinocytes, as well as their distinctive potential to decrease inflammation and emit pro-angiogenic molecules at the site of wounds. More recent investigations revealed that MSCs can exert numerous direct and indirect antimicrobial effects that are immunologically mediated. Collectively, these antimicrobial properties can remove bacterial infections when the MSCs are delivered in a therapeutic setting. Regardless of the positive therapeutic potential of MSCs for a multitude of conditions, transplanted MSC cell retention continues to be a major challenge. Since MSCs are typically administered into naturally hypoxic tissues, understanding the impact of hypoxia on the functioning of MSCs is crucial. Hypoxia has been postulated to be among the factors determining the differentiation of MSCs, resulting in the production of inflammatory cytokines throughout the process of tissue regeneration and wound repair. This has opened new horizons in developing MSC-based systems as a potent therapeutic tool in oxygen-deprived regions, including anaerobic wound infection sites. This review sheds light on the role of hypoxia-MSCs in the treatment of anaerobic bacterial wound infection in terms of both their regenerative and antimicrobial activities. [ABSTRACT FROM AUTHOR]

It is an active research area in the development of engineered bacteria to address the bottleneck issue of hypoxic tumors, which otherwisely possess resistance to chemotherapies, radiotherapies, and photodynamic therapies. Here we report a new method to ablate hypoxic tumors with NIR-nanoantenna sensitized engineered bacteria (NASEB) in a highly effective and dual selective manner. It features engineered E. coli MG1655 (EB) with coatings of lanthanide upconversion nanoparticles (UCNPs) as external antennas on bacterial surface (MG1655/HlyE-sfGFP@UCNP@PEG), enabling NIR laser-switchable generation/secretion of HlyE perforin to kill cancer cells. We have demonstrated that NASEB enrichment on hypoxic tumor sites via their innate chemotactic tendency, in assistance of localized NIR laser irradiation, can suppress tumors with improved efficacy and selectivity, thus minimizing potential side effects in cancer treatment. The NIR-responsive nanoantenna sensitized switching in engineering bacteria is distinct from the previous reports, promising conceptually new development of therapeutics against hypoxic tumors. Tumor hypoxia exacerbates tumor progression, but also reduces the efficacy of conventional chemotherapies, radiotherapies, or photodynamic therapies. Here we develop near infrared Nano Antenna Sensitized Engineered Bacteria (NASEB) to treat hypoxic tumors. NASEB can accumulate and proliferate on hypoxic tumor sites via their innate chemotactic tendency. After receiving NIR laser signals, the upconversion nanoparticles on NASEB surface as antennas can transduce them to blue light for activation of HlyE perforin in the protein factory of EB. Our method features dual selectivity on the tumor sites, contributed by hypoxic tumor homing of anaerobic bacteria and spatial confinement through selective NIR laser irradiation. The concept of NASEB promises to address the challenges of tumor hypoxia for cancer therapies. [Display omitted] [ABSTRACT FROM AUTHOR]

The hypoxic tumor microenvironment (TME) significantly affects cancer treatment. Conventional chemotherapeutic agents cannot effectively target hypoxic tumor tissue, which decreases efficacy and results in severe toxic side effects. To alleviate this problem, a self‐driving biomotor is developed by functionalizing MCDP nanoparticles containing calcium peroxide and doxorubicin (DOX) loaded onto polydopamine‐coated metal–organic frameworks（MOF）, with the anaerobic Bifidobacterium infantis (Bif) for synergistic chemotherapy and chemodynamic therapy (CDT) against breast cancer. The materials of institute Lavoisier (MIL) frameworks + CaO2 + DOX + polydopamine (MCDP)@Bif biohybrid actively targets hypoxic regions of solid tumors via the inherent targeting ability of Bif. Once it has accumulated in the tumor tissue, MCDP generates hydroxyl radicals through the enhanced Fenton‐type reactions between Fe2+ and self‐generated hydrogen peroxide in the acidic TME. The disruption of Ca2+ homeostasis and resulting mitochondrial Ca2+ overload triggers apoptosis and enhances oxidative stress, promoting tumor cell death. The results found that the DOX concentration in MCDP@Bif‐treated tumors is 3.8 times higher than that in free‐DOX‐treated tumors, which significantly prolongs the median survival of the tumor‐bearing mice to 69 days and reduces the toxic side effects of DOX. Therefore, the novel bacteria‐driven drug delivery system is highly effective in achieving synergistic chemotherapy and CDT against solid tumors. [ABSTRACT FROM AUTHOR]

Objectives. This study aimed to evaluate the effects of different cleaning regimes of acrylic-based removable orthodontic appliances on bacterial biofilm formation and whether the surface modification, i.e., polished acrylic fitting surface, reduces biofilm formation. Materials and Methods. This double-blind, parallel, randomized clinical trial involved thirty-nine orthodontic patients indicated for removable orthodontic appliances. The patients were allocated into three groups according to the cleaning method: brushing with a denture brush and chlorhexidine (CHX) toothpaste, Lacalut cleaning tablet, and a combination of both cleaning methods. Each patient wore an upper removable appliance containing eight wells fitted with eight detachable acrylic tiles (four polished and four unpolished) for seven days. Five types of oral microbiota were evaluated using selective growth media and biochemical tests. The biofilm cleaning efficacy was assessed using the colony-forming unit (CFU) and scanning electron microscopy (SEM). Statistical Analysis. Data from the CFU using different cleansing regimes were compared, following log transformation, using one-way analysis of variance (ANOVA). The polished and unpolished tiles were compared for biofilm formation on each cleansing method using an independent t-test. Results. There was no significant difference among the three cleaning methods on the polished or unpolished tiles. However, in polished tiles, streptococci were significantly reduced in all cleaning methods, whereas staphylococci and Staphylococcus aureus were markedly decreased in brushing and combination cleaning methods. However, the total number of anaerobic bacteria was significantly reduced in polished tiles using the combination method only. Conclusions. Polishing the fitting surface of an acrylic-based orthodontic appliance reduced the tested bacterial biofilm formation and may enhance cleaning efficiency. Brushing and combination methods showed superior cleaning effects compared to cleaning tablets. This trial is registered with NCT05707221. [ABSTRACT FROM AUTHOR]

This study included 72 participants with oral halitosis (35 men and 37 women), who had been clinically diagnosed and ranged in age from 14 to 70. 95 samples were obtained using sterile paper points (size 30) or sterile cotton swabs, in either aerobic or anaerobic conditions, thioglycolate broth was transported and blood agar was used for culture (for 48–72 hours). The bacteria were recognized by means of biochemical testing, tests for antibiotic susceptibility, and morphological and cultural features. Results revealed that 13 different bacterial species were isolated in this study, including Bacteriodes spp. (26 isolates), Viridans Streptococci (18 isolates), Peptostreptococci (19 isolates), Actinomyces spp. (15 isolates), Porphyromonas spp. (8 isolates), Fusobacterium spp. (9 isolates), Veillonella spp. (5 isolates), Streptococcus spp. (10 (2 isolates). The dominant anaerobic bacterial species and genera in instances of halitosis is the conclusion. [ABSTRACT FROM AUTHOR]

The influence of bacterial nutrition (by ethanol) on the appearance of hydrogen sulfide and colloidal sulfur in the filtrate of innovative U-shaped small-sized (point-of-use) submersible denitrifying biofilter describes in the course of its regular operation. The device intends to get drinking water from groundwater sources contaminated with nitrates, sulfates, and heavy metal ions. Colonies of denitrifying bacteria occupy an ecological niche inside the filter bed in an anoxic medium in the inlet elbow of the biofilter and reduce the concentration of nitrates below of hygienic limit at the optimal feed by ethanol. Hydrogen sulfide and colloidal sulfur produce the sulfate-reducing and sulfur bacteria. Sulfate-reducing bacteria act in an anaerobic environment in the bottom conjunction zone of the inlet and outlet elbows of the biofilter. These bacteria release hydrogen sulfide when ethanol adds to filtering water in excess compared to the dosage required for denitrification. Colonies of sulfur bacteria occupy an ecological niche in the output zone of the biofilter exit elbow and oxidise hydrogen sulfide to elemental sulfur. Sulfate reduction associated with nitrates removal can be helpful for additional water purification from admixtures of heavy and polyvalent metal ions. [ABSTRACT FROM AUTHOR]

Cutibacterium acnes, an integral component of the skin's customary bacterial flora, represents a Gram-positive anaerobic bacterium characterized by its low virulence. Despite its low virulence, the pathogen can cause profound-seated infections as well as infections linked to medical devices. We report a case study of a prosthesis endocarditis accompanied by a paraaortic abscess caused by C. acnes, a development occurring five years prior to composite aortic root and valve replacement. At the point of admission, the patient presented with a combination of symptoms hinting at a subacute progression, such as weight loss, chest pain, and limitations of cardiopulmonary functionality. An anaerobic pathogen, namely C. acnes, was detected in a singular blood culture vial. Since first-line imaging modalities such as echocardiography did not reveal any signs of inflammation, and in the case of a suspected diagnosis for IE, did not show high pretest probability, further diagnostic imaging such as 18F-FDG PET CT was put to use. Here, a highly elevated glucose metabolism around the aortic valve ring was detected, pointing to an inflammatory process. The patient received adjusted intravenous antibiotic therapy over a course of six weeks; he then underwent surgical therapy via re-replacement of the aortic root and valve using a composite conduit. Advanced microbiological analyses, including the amplification of PCR and valve sequencing via 16S rDNA, mainly detected one pathogen: C. acnes. Delayed onset with mild symptoms and laboratory findings is characteristic of infective endocarditis by C. acnes. Due to its high rate of complications, mortality, and morbidity, an infection should not be disregarded as contamination. Recommendations from different studies underline a combination of a positive blood culture and microbiological evidence to differentiate between contamination and true infection in the case of an infection involving C. acnes. Serial blood cultures with prolonged incubation, advanced microbiological analyses, and modified Duke criteria including second-line imaging techniques should be utilized for further evaluation. [ABSTRACT FROM AUTHOR]

Objective The study is aiming to explore the key corrosion bacteria in the production process of shale gas, and analyze the potential succession law of bacteria. Methods The 16S rRNA high-throughput sequencing analysis technology was used to sequence the bacterial flora in the fracturing fluid preparation water and produced water of a shale gas platform in Weiyuan area. Results The bacterial structure of fresh water is completely different from that of produced water and recycled flowback fluid, the richness and diversity of bacteria decreased after fracturing. The key corrosive bacteria include Arcobacter, Marinobacterium and Pseudomonas, etc. The bacterial community in the freash water is mainly composed of mesophilic, aerobic bacteria with weak functions such as sulfate reduction and acid production. While in the recycled flowback fluid, there are a large number of bacteria with functions of sulfur metabolism, acid production and biofilm production. After fracturing, in the produced water there are mainly facultative anaerobic, anaerobic or strictly anaerobic bacteria with functions such as sulfate reduction, sulfur reduction, sulfur oxidation, acid production, biofilm production, iron reduction, and some thermophilic bacteria were identified. Conclusion This provides theoretical and technical support for further research on bacterial corrosion of gathering and transportation pipelines and pipeline protection. [ABSTRACT FROM AUTHOR]

Enterococcus species are Gram-positive cocci that are characterized by being catalasenegative, facultative anaerobic bacteria, and non-spore forming. Enteroccoi is often isolated from environmental and animal sources and inhabits the human gastrointestinal tract. Enterococcus species, which gets its resources from the dairy industry, animals, and people, is one of the most abundant lactic acid bacteria in raw milk. The aim of the present study is to detect antibiotic resistance of Enterococci isolated from raw milk by phenotypic and genotypic methods. Vitek 2 Compact System was used to identify the samples and assess their antimicrobial susceptibility. Following that, drug resistance genes (ermB, aph (3')-IIIa, and TetM) and one virulence gene (esp) were molecularly detected by PCR. Twenty isolates of Enterococci were phenotypically identified by routine laboratory examination and Vitek2. High rates of antibiotic resistance were found to erythromycin and tetracycline with percentages of 65% and 35%, respectively. The presence of tetM and ermB in milk isolates was found to be 100%, similarly. No detection of aph (3')IIIa was found in milk isolates. Esp was detected only in 5% of isolated samples. The prevalence of Enterococci among studied samples was 11.8% (20/170). The fact that Enterococci were resistant to erythromycin and tetracycline in our study was noteworthy since these bacteria could potentially be transmitted to people by drinking milk that has not been properly treated. [ABSTRACT FROM AUTHOR]

Purpose: To analyse the epidemiology, treatment, and microbiological findings of hospitalised Lithuanian children and adolescents admitted due to maxillofacial infections over a 17-years period. Methods: 428 medical records of paediatric (under the age of 18) patients hospitalised at Vilnius University Hospital from 2003 to 2019 due to a maxillofacial infection were reviewed. The data concerning patient sociodemographic characteristics, aspects related to a hospital stay, treatment modalities, microbiological findings, and sensitivity to antibiotics, were collected and analysed. Results: The most prevalent condition was odontogenic maxillofacial space infection (28.7%), followed by lymphadenitis (21.7%). The mean (sd) age was 10.86 (4.8) years and the male-to-female ratio was 1.37:1. The majority of patients (83.4%) underwent surgical treatment. The mean (sd) hospital stay was 5.49 (2.9) days. The longest hospital stay was observed in the case of odontogenic maxillofacial space infections. A longer period of hospitalisation was generally associated with the presence of anaerobes and their resistance to antibiotics as well as multiple space involvement in deep neck space infections and a permanent causative tooth in odontogenic cases. The most commonly isolated microbiological species was Staphylococcus aureus spp. Conclusion: The most common origin of maxillofacial infection was odontogenic among investigated Lithuanian children and adolescents. In the majority of cases, a penicillin group antibiotic was prescribed. Streptococci were the predominant bacteria in the cases of odontogenic infection, while Staphylococci were the most prevalent among non-odontogenic cases. Nearly 40.0% of isolated microorganisms were resistant to penicillin. High resistance to metronidazole was identified among anaerobic bacteria. [ABSTRACT FROM AUTHOR]

Commensal bacteria like the Staphylococcal species are part of the skin microbiota, which helps maintain healthy skin. However, certain factors can lead to these commensals becoming opportunistic pathogens capable of causing diseases like acne vulgaris. Topical and systemic antibiotics have been the main treatment for acne. However, long-term antibiotic usage could result in the emergence of resistant bacterial strains and treatment failure. This study evaluated the antibiotic susceptibility patterns of anaerobic bacteria isolated from clinical acne samples. Skin swabs were collected from 50 acne patients and cultured under anaerobic conditions. The resulting bacterial isolates were identified using biochemical tests and 16S rRNA gene sequencing. The antibiotic susceptibility patterns of the confirmed isolates were determined using the disc diffusion assay for eight commonly prescribed antibiotics for acne treatment. Sequencing results revealed that S. epidermidis was the most isolated bacterial species (68%, n=34), followed by S. aureus (8%, n=4). However, a significant proportion of bacterial isolates were susceptible to all eight tested antibiotics, which is unusual. On the other hand, 26% (n=13) of the tested bacterial species isolates were found to be resistant to clindamycin, while 36% (18) were resistant to erythromycin and 20% (n=10) were to tetracycline. Since there has been limited research regarding the antibiotic resistance patterns of anaerobic acne-associated bacteria in Malaysia, this study can help shed some light on suitable local prescription practices and raise awareness about the cautious use of antibiotics in treating acne vulgaris. [ABSTRACT FROM AUTHOR]

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Sampling of ruminant saliva has gained interest as a non-invasive proxy for exploring the structure of the rumen microbiome. However, the subsequent data analysis assumes that bacteria originating from the oral cavity are merely passengers in the rumen and play no active role. In this study, it was hypothesised that metabolically active oral bacteria present in the salivary microbiome play a role in the ruminal degradation of plant material. In vitro cultivation-based enumeration confirmed that the ruminant oral cavity harbours a significant number of anaerobic and cellulolytic bacteria that are metabolically active under ruminal conditions. Bacterial 16S rRNA gene profiling of in vitro enrichments also confirmed that oral-derived bacteria were capable of colonising plant material. Preliminary analysis of the colonising bacteria indicated that bacteria belonging to the genus Streptococcus were of particular interest. In conclusion, the findings of the current study clearly indicate that bolus-associated bacteria have the potential to play a metabolically active role in terms of ruminal colonisation and the degradation of plant material. This evidence confirms the merit of the hypothesis that the metabolically active oral bacteria present in the salivary microbiome may play a role in the ruminal degradation of plant material. [ABSTRACT FROM AUTHOR]

Bacteria of the genus Bacillus and related genera (e.g., Paenibacillus, Alicyclobacillus or Brevibacillus) belong to the phylum Firmicutes. Taxonomically, it is a diverse group of bacteria that, to date, has not been well described phylogenetically. The group consists of aerobic and relatively anaerobic bacteria, capable of spore-forming. Bacillus spp. and related genera are widely distributed in the environment, with a particular role in soil. Their abundance in the agricultural environment depends mainly on fertilization, but can also depend on soil cultivated methods, meaning whether the plants are grown in monoculture or rotation systems. The highest abundance of the phylum Firmicutes is usually recorded in soil fertilized with manure. Due to the great abundance of cellulose in the environment, one of the most important physiological groups among these spore-forming bacteria are cellulolytic bacteria. Three key cellulases produced by Bacillus spp. and related genera are required for complete cellulose degradation and include endoglucanases, exoglucanases, and β-glucosidases. Due to probable independent evolution, cellulases are encoded by hundreds of genes, which results in a large structural diversity of these enzymes. The microbial degradation of cellulose depends on its type and environmental conditions such as pH, temperature, and various substances including metal ions. In addition, Bacillus spp. are among a few bacteria capable of producing multi-enzymatic protein complexes called cellulosomes. In conclusion, the taxonomy of Bacillus spp. and related bacteria needs to be reorganized based on, among other things, additional genetic markers. Also, the ecology of soil bacteria of the genus Bacillus requires additions, especially in the identification of physical and chemical parameters affecting the occurrence of the group of bacteria. Finally, it is worth adding that despite many spore-forming strains well-studied for cellulolytic activity, still few are used in industry, for instance for biodegradation or bioconversion of lignocellulosic waste into biogas or biofuel. Therefore, research aimed at optimizing the cellulolytic properties of spore-forming bacteria is needed for more efficient commercialization. [ABSTRACT FROM AUTHOR]

On the basis of routine microbiological tests and selected physicochemical parameters, the quality and food safety of Polish varietal honeys were evaluated. The study included 21 honey samples from 5 varieties (multifloral, honeydew, rapeseed, buckwheat and linden), in which the moisture and extract content, water activity, pH and free acids were determined, and the colony count, the presumptive Bacillus spp., the total fungal count and the presence of anaerobic spore-forming bacilli were examined. More than half (52%, 11/21) of the analyzed honeys contained fewer microorganisms than 10 cfu/g, and in the remaining samples, their numbers ranged from 5 × 101 cfu/g to 4.5 × 102 cfu/g. In all the honeys, the number of presumptive Bacillus spp. in 1 g was less than 10 cfu. In 81% (17/21) of the samples, the total count of fungi in 1 g of honey was less than 10 cfu, and the most contaminated was buckwheat honey (3 samples). The anaerobic spore-forming bacteria was detected in 0.1 g only in one sample of buckwheat honey. The values of the physicochemical parameters did not exceed the accepted limits, which indicated that the honey environment was unfavourable for the development of the tested microbial profile. [ABSTRACT FROM AUTHOR]

Objectives: Patients with a peritonsillar abscess (PTA) often present to emergency departments as the first point of medical contact. Upper respiratory tract infections (URTIs) are more frequent in the winter. Therefore, we hypothesize that the incidence of PTAs will be more frequent in colder winter months as well. This is the first study assessing the seasonal variation and epidemiology of PTA presentations to an emergency department in Atlantic Canada, home to a unique maritime climate. Methods: A retrospective cohort study was conducted through a chart review of all patients who presented to the Saint John Regional Hospital Emergency Department from January 1, 2015, to December 31, 2020. Patient characteristics, treatment, and microbiology were reported. A chi-square goodness-of-fit test assessed the seasonal variation of PTA. Pearson correlations assessed PTA incidence per mean monthly temperature and humidity. Results: A total of 75 patients were included. 57.3% were male and 42.7% were female, with a mean age (±SD) of 35.9 ± 14.0. Most patients presented afebrile (82.7%, cutoff ≥ 38.0°C). Approximately half of all patients had an elevated WBC count (49.3%, cutoff ≥ 10.9 × 109). The most common bacteria isolated were Streptococcus species followed by anaerobic bacteria (17.9%). No significant variation was found with respect to season (X2(3) = 1.0, P =.801), temperature (r(70) = 0.198, P =.096), or humidity, (r(70) = 0.063, P =.599). Conclusion: This study did not find a seasonal variation of PTA in a maritime climate. These findings question the anecdotal hypothesis that PTA is associated with progression from acute URTIs and therefore would be more common in the winter months. [ABSTRACT FROM AUTHOR]

The etiology of irritable bowel syndrome (IBS) is unknown. Abnormal intestinal bacterial profiles and low bacterial diversity appear to play important roles in the pathophysiology of IBS. This narrative review was designed to present recent observations made relating to fecal microbiota transplantation (FMT), which implicate possible roles of 11 intestinal bacteria in the pathophysiology of IBS. The intestinal abundances of nine of these bacteria increased after FMT in patients with IBS, and these increases were inversely correlated with IBS symptoms and fatigue severity. These bacteria were Alistipes spp., Faecalibacterium prausnitzii, Eubacterium biforme, Holdemanella biformis, Prevotella spp., Bacteroides stercoris, Parabacteroides johnsonii, Bacteroides zoogleoformans, and Lactobacillus spp. The intestinal abundances of two bacteria were decreased in patients with IBS after FMT and were correlated with the severity of IBS symptoms and fatigue (Streptococcus thermophilus and Coprobacillus cateniformis). Ten of these bacteria are anaerobic and one (Streptococcus thermophilus) is facultative anaerobic. Several of these bacteria produce short‐chain fatty acids, especially butyrate, which is used as an energy source by large intestine epithelial cells. Moreover, it modulates the immune response and hypersensitivity of the large intestine and decreases intestinal cell permeability and intestinal motility. These bacteria could be used as probiotics to improve these conditions. Protein‐rich diets could increase the intestinal abundance of Alistipes, and plant‐rich diet could increase the intestinal abundance of Prevotella spp., and consequently improve IBS and fatigue. [ABSTRACT FROM AUTHOR]

Mikania micrantha is an economically damaging invasive weed, which is widely naturalized in the tropical and subtropical regions of the world. This weed has reported yield losses in various cash crops and plantation crops in South East Asia including India. M. micrantha was found to change the soil microbial communities (bacteria, fungi and actinomycetes) as well as the soil chemical properties. It enhances a significant increase in aerobic bacteria but decreases in anaerobic bacteria due to which infested soil were free from other weeds. Similarly, in soil chemical characteristics significant increases in pH, total N and P were observed and a decrease in soil organic matter where M. micrantha is prevalent. It has allelopathic properties which affect neighbouring crops, weeds, insects and pathogens. This weed produces allelochemicals (phenolics, flavonoids, alkaloids and terpenes) that may be released by volatilization and decomposition of plant debris. It was also found that the aqueous leaf extract of invasive weed M. micrantha inhibited seed germination and seedling growth of various cereals, vegetables, and other plants. A similar result was found in test crops but there was no affected case found in the greenhouse experiment. This review will help the researchers and scientists in understanding the harmful effect of this invasive weed. [ABSTRACT FROM AUTHOR]