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ABSTRACT Brain abscess is a severe infection characterized by the accumulation of pus within the brain parenchyma. Accurate identification of the causative pathogens is crucial for effective treatment and improved patient outcomes. This 10-year retrospective, single-center study aimed to compare the detection performance of conventional culture methods and metagenomic next-generation sequencing (mNGS) in brain abscess. We reviewed 612 patients diagnosed with brain abscess and identified 174 cases with confirmed etiology. The median age was 52 years, with 69.5% males. Culture tests predominately identified gram-positive bacteria, particularly Streptococcus spp. Gram-negative bacteria, including Klebsiella spp., were also detected. However, mNGS revealed a more diverse pathogen spectrum, focusing on anaerobes (e.g., Fusobacterium spp., Parvimonas spp., Porphyromonas spp., Prevotella spp., and Tannerella spp.). mNGS exhibited significantly higher overall pathogen-positive rates in pus samples (85.0% vs 50.0%, P = 0.0181) and CSF samples (84.2% vs 7.9%, P < 0.0001) compared to culture. Furthermore, the detection rates for anaerobes displayed a notable disparity, with mNGS yielding significantly higher positive detections in both pus samples (50.0% vs 10%, P = 0.0058) and CSF samples (18.4% vs 0%, P = 0.0115) when compared to culture methods. The assistance of mNGS in pathogen detection, particularly anaerobes in brain abscess, was evident in our findings. mNGS demonstrated the ability to identify rare and fastidious pathogens, even in culture-negative cases. These results emphasize the clinical value of mNGS as a supplement for brain abscess, enabling more comprehensive and accurate pathogen identification.IMPORTANCEThe accurate identification of pathogens causing brain abscess is crucial for effective treatment and improved patient outcomes. In this 10-year retrospective study, the detection performance of conventional culture methods and metagenomic next-generation sequencing (mNGS) was compared. The study analyzed 612 patients with brain abscess and confirmed etiology in 174 cases. The results showed that culture tests predominantly identified gram-positive bacteria, while mNGS unveiled a broader diverse pathogen spectrum, particularly anaerobes. The mNGS method exhibited significantly higher overall rates of pathogen positivity both in pus and cerebrospinal fluid (CSF) samples, surpassing the culture methods. Notably, mNGS detected a significantly higher number of anaerobes in both pus and CSF samples compared to culture methods. These findings underscore the clinical value of mNGS as a supplement for brain abscess diagnosis, enabling more comprehensive and accurate pathogen identification, particularly for rare and fastidious pathogens that evade detection by conventional culture methods.

Tissue engineering offers a promising alternative for oral and maxillofacial tissue defect rehabilitation; however, cells within a sizeable engineered tissue construct after transplantation inevitably face prolonged and severe hypoxic conditions, which may compromise the survivability of the transplanted cells and arouse the concern of anaerobic infection. Microalgae, which can convert carbon dioxide and water into oxygen and glucose through photosynthesis, have been studied as a source of oxygen supply for several biomedical applications, but their promise in orofacial tissue regeneration remains unexplored. Here, we demonstrated that through photosynthetic oxygenation, Chlamydomonas reinhardtii (C. reinhardtii) supported dental pulp stem cell (DPSC) energy production and survival under hypoxia. We developed a multifunctional photosynthetic hydrogel by embedding DPSCs and C. reinhardtii encapsulated alginate microspheres (CAMs) within gelatin methacryloyl hydrogel (GelMA) (CAMs@GelMA). This CAMs@GelMA hydrogel can generate a sustainable and sufficient oxygen supply, reverse intracellular hypoxic status, and enhance the metabolic activity and viability of DPSCs. Furthermore, the CAMs@GelMA hydrogel exhibited selective antibacterial activity against oral anaerobes and remarkable antibiofilm effects on multispecies biofilms by disrupting the hypoxic microenvironment and increasing reactive oxygen species generation. Our work presents an innovative photosynthetic strategy for oral tissue engineering and opens new avenues for addressing other hypoxia-related challenges.

Abstract Peri-implantitis is a bacterial infection that causes soft tissue inflammatory lesions and alveolar bone resorption, ultimately resulting in implant failure. Dental implants for clinical use barely have antibacterial properties, and bacterial colonization and biofilm formation on the dental implants are major causes of peri-implantitis. Treatment strategies such as mechanical debridement and antibiotic therapy have been used to remove dental plaque. However, it is particularly important to prevent the occurrence of peri-implantitis rather than treatment. Therefore, the current research spot has focused on improving the antibacterial properties of dental implants, such as the construction of specific micro-nano surface texture, the introduction of diverse functional coatings, or the application of materials with intrinsic antibacterial properties. The aforementioned antibacterial surfaces can be incorporated with bioactive molecules, metallic nanoparticles, or other functional components to further enhance the osteogenic properties and accelerate the healing process. In this review, we summarize the recent developments in biomaterial science and the modification strategies applied to dental implants to inhibit biofilm formation and facilitate bone-implant integration. Furthermore, we summarized the obstacles existing in the process of laboratory research to reach the clinic products, and propose corresponding directions for future developments and research perspectives, so that to provide insights into the rational design and construction of dental implants with the aim to balance antibacterial efficacy, biological safety, and osteogenic property.

Bacteriological studies of well water mainly focus on aerobic and facultative aerobic coliform bacteria. However, the presence of obligate anaerobic bacteria in well water, especially sulfate-reducing bacteria (SRB), possible causative agents of some diseases, is often ignored. In this study, the presence of SRB and coexisting anaerobic bacteria with SRB in sulfate-reducing enrichment cultures obtained from 10 well water samples in Istanbul was investigated. A nested polymerase chain reaction-denaturing gradient gel electrophoresis strategy was performed to characterize the bacterial community structure of the enrichments. The most probable number method was used to determine SRB number. Out of 10, SRB growth was observed in only one (10%) enrichment culture and the SRB number was low (

Abstract Acne is a prevalent dermatological disease, with high global incidence, and is a health menace. The current study aimed to isolate and characterize the anaerobic bacteria responsible for the condition. Causes of a total of 70 acne-based bacterium isolates obtained from patients of mild, moderate, and severe acne, 24 were Clostridium innocuum, 21 were Lactobacillus plantarum, 13 were Anaerococcus prevotii, and 12 were Peptoniphilus asaccharolyticus. Nearly 69% of males were suffering, while the rest were females at 31%. The 15–30 years old age group was the most affected. The gold/alginate nanoparticles’ nanopreparation (GANPs) produced from chloroauric acid and sodium alginate was an effective treatment against the acne conditions under the experimental conditions. The nanopreparation exhibited significant inhibitory activity against anaerobic bacterial isolates, with a minimum inhibitory concentration of 200 µg/ml for A. prevotii and P. asaccharolyticus, and 400 µg/ml for C. innocuum and L. plantarum. The in vitro efficacy of the GANPs on human blood parameters was also assessed. The concurrent results suggested potential antibacterial activity and hemocompatibility of the product, which has promise to be used as a successful antibacterial agent for acne.

Antibiotic resistance is a global threat driven primarily by antibiotic use. We evaluated the effects of antibiotic exposures on the gut microbiomes and resistomes of children at high risk of colonization by antibiotic-resistant bacteria. We performed shotgun metagenomic sequencing of 691 serially collected fecal samples from 80 children (

Abstract The understanding of how central metabolism and fermentation pathways regulate antimicrobial susceptibility in the anaerobic pathogen Bacteroides fragilis is still incomplete. Our study reveals that B. fragilis encodes two iron‐dependent, redox‐sensitive regulatory pirin protein genes, pir1 and pir2. The mRNA expression of these genes increases when exposed to oxygen and during growth in iron‐limiting conditions. These proteins, Pir1 and Pir2, influence the production of short‐chain fatty acids and modify the susceptibility to metronidazole and amixicile, a new inhibitor of pyruvate: ferredoxin oxidoreductase in anaerobes. We have demonstrated that Pir1 and Pir2 interact directly with this oxidoreductase, as confirmed by two‐hybrid system assays. Furthermore, structural analysis using AlphaFold2 predicts that Pir1 and Pir2 interact stably with several central metabolism enzymes, including the 2‐ketoglutarate:ferredoxin oxidoreductases Kor1AB and Kor2CDAEBG. We used a series of metabolic mutants and electron transport chain inhibitors to demonstrate the extensive impact of bacterial metabolism on metronidazole and amixicile susceptibility. We also show that amixicile is an effective antimicrobial against B. fragilis in an experimental model of intra‐abdominal infection. Our investigation led to the discovery that the kor2AEBG genes are essential for growth and have dual functions, including the formation of 2‐ketoglutarate via the reverse TCA cycle. However, the metabolic activity that bypasses the function of Kor2AEBG following the addition of phospholipids or fatty acids remains undefined. Overall, our study provides new insights into the central metabolism of B. fragilis and its regulation by pirin proteins, which could be exploited for the development of new narrow‐spectrum antimicrobials in the future.

Background: Bacteremia represents high rates of morbidity and mortality, especially in developing countries, highlighting the need for a diagnostic method that allows prompt and appropriate patient treatment. This study compared microbiological performance and adherence of two blood culture protocols for the diagnosis of bacteremia. Methods: Quasi-experimental study conducted between June 2022 and February 2023. Two blood culture protocols were evaluated. Protocol 1 included two aerobic bottles and one anaerobic bottle. Protocol 2 included two aerobic and two anaerobic bottles. Protocols were analyzed in three phases: evaluation of protocol 1 (Phase 1); evaluation of protocol 1 plus educational activities for healthcare staff (Phase 2) and evaluation of protocol 2 (Phase 3). Results: 342 patients and 1155 blood culture bottles (732 aerobic and 423 anaerobic) were included. Positivity was 17.6 %, 22.8 % and 19.4 % in phases 1, 2 and 3, respectively. Among patients with bacteremia, 84.5 % had positive anaerobic bottles, with 9.9 % showing growth only in this bottle. The contamination rates were 1.9 %, 0.3 %, and 0.8 % for each phase, mainly in aerobic bottles. Median positivity time was 11 h for both bottes aerobic and anaerobic. Overall nursing adherence increased from 13.1 % in Phase 1, 25.9 % in Phase 2, and 28.1 % in Phase 3 (p = 0.009). Conclusions: The findings indicate that adding a second anaerobic bottle does not enhance blood culture positivity. Rather than increasing bottle quantity, staff training might be a more effective approach to optimize results.

The symbiotic relationship between the human digestive system and its intricate microbiota is a captivating field of study that continues to unfold. Comprising predominantly anaerobic bacteria, this complex microbial ecosystem, teeming with trillions of organisms, plays a crucial role in various physiological processes. Beyond its primary function in breaking down indigestible dietary components, this microbial community significantly influences immune system modulation, central nervous system function, and disease prevention. Despite the strides made in microbiome research, the precise mechanisms underlying how bacterial effector functions impact mammalian and microbiome physiology remain elusive. Unlike the traditional DNA-RNA-protein paradigm, bacteria often communicate through small molecules, underscoring the imperative to identify compounds produced by human-associated bacteria. The gut microbiome emerges as a linchpin in the transformation of natural products, generating metabolites with distinct physiological functions. Unraveling these microbial transformations holds the key to understanding the pharmacological activities and metabolic mechanisms of natural products. Notably, the potential to leverage gut microorganisms for large-scale synthesis of bioactive compounds remains an underexplored frontier with promising implications. This review serves as a synthesis of current knowledge, shedding light on the dynamic interplay between natural products, bacteria, and human health. In doing so, it contributes to our evolving comprehension of microbiome dynamics, opening avenues for innovative applications in medicine and therapeutics. As we delve deeper into this intricate web of interactions, the prospect of harnessing the power of the gut microbiome for transformative medical interventions becomes increasingly tantalizing.

Background: Blood culture (BC) systems have evolved to increase sensitivity and reduce turnaround times. This study compared the performance of a 4-day versus a 5-day BC incubation period using the BD BACTEC™ FX (Becton, Dickinson and Company, USA). Methods: A total of 37,379 consecutive sets of BC were evaluated over a 3-month period in a 2,700-bed tertiary care hospital. Positive BC results were reviewed to assess time-to-positivity (TTP) and species identification of the isolates. The BCs were performed in pairs of vials, utilizing either BD BACTEC Plus Aerobic/F or Peds Plus/F with BD BACTEC Lytic Anaerobic media. Results: A total of 14,899 episodes, averaging 2.51 sets per episode, were analyzed. Of these, 1,398 (9.38%) were positive, yielding 1,465 isolates. TTP (hours) were < 12 in 48.87%, 12-24 in 31.40%, 24-48 in 13.38%, 48-72 in 3.28%, 72-96 in 1.43%, and >96 in 1.64%. The two most prevalent organisms, Escherichia coli and Klebsiella spp. were detected within 12 hours in 88.75% and 78.90%, respectively. The respective median TTP (T50) values for E. coli, Klebsiella spp., Enterococcus faecalis/E. faecium, and Staphylococcus aureus were 9.24, 9.60, 13.75, and 14.20. T50 values for these species were significantly shorter in anaerobic bottles than in aerobic bottles. Of 24 BCs with TTP > 96, only 4 containing anaerobic bacteria or molds were f irst detected after 96 hours. Conclusion: A 4-day incubation has demonstrated excellent sensitivity. However, a 5-day incubation may be beneficial for hospitals caring for patients at high risk for infections with slow-growing fungi or fastidious bacteria.

Antimicrobial resistance is a global concern, far from being resolved. The need of new drugs against new targets is imminent. In this work, we present a family of aminoalkyl resveratrol derivatives with antibacterial activity inspired by the properties of cationic amphipathic antimicrobial peptides. Surprisingly, the newly designed molecules display modest activity against aerobically growing bacteria but show surprisingly good antimicrobial activity against anaerobic bacteria (Gram-negative and Gram-positive) suggesting specificity towards this bacterial group. Preliminary studies into the action mechanism suggest that activity takes place at the membrane level, while no cross-resistance with traditional antibiotics is observed. Actually, some good synergistic relations with existing antibiotics were found against Gram-negative pathogens. However, some cytotoxicity was observed, despite their low haemolytic activity. Our results show the importance of the balance between positively charged moieties and hydrophobicity to improve antimicrobial activity, setting the stage for the design of new drugs based on these molecules.

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.

ABSTRACTAnaerobic microbes play crucial roles in environmental processes, industry, and human health. Traditional methods for monitoring the growth of anaerobes, including plate counts or subsampling broth cultures for optical density measurements, are time and resource-intensive. The advent of microplate readers revolutionized bacterial growth studies by enabling high-throughput and real-time monitoring of microbial growth kinetics. Yet, their use in anaerobic microbiology has remained limited. Here, we present a workflow for using small-footprint microplate readers and the Growthcurver R package to analyze the kinetic growth metrics of anaerobic bacteria. We benchmarked the small-footprint Cerillo Stratus microplate reader against a BioTek Synergy HTX microplate reader in aerobic conditions using Escherichia coli DSM 28618 cultures. The growth rates and carrying capacities obtained from the two readers were statistically indistinguishable. However, the area under the logistic curve was significantly higher in cultures monitored by the Stratus reader. We used the Stratus to quantify the growth responses of anaerobically grown E. coli and Clostridium bolteae DSM 29485 to different doses of the toxin sodium arsenite. The growth of E. coli and C. bolteae was sensitive to arsenite doses of 1.3 µM and 0.4 µM, respectively. Complete inhibition of growth was achieved at 38 µM arsenite for C. bolteae and 338 µM in E. coli. These results show that the Stratus performs similarly to a leading brand of microplate reader and can be reliably used in anaerobic conditions. We discuss the advantages of the small format microplate readers and our experiences with the Stratus.IMPORTANCEWe present a workflow that facilitates the production and analysis of growth curves for anaerobic microbes using small-footprint microplate readers and an R script. This workflow is a cost and space-effective solution to most high-throughput solutions for collecting growth data from anaerobic microbes. This technology can be used for applications where high throughput would advance discovery, including microbial isolation, bioprospecting, co-culturing, host-microbe interactions, and drug/toxin-microbial interactions.

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.

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.

IntroductionIn recent years, researchers have been exploring the plastic-degrading abilities of bacteria residing in the guts of Styrofoam-eating Tenebrio molitor larvae. However, none of the reported strains have displayed highly efficient plastic degradation capabilities, and it’s noteworthy that none of the existing studies have focused on strictly anaerobic microbes.MethodsIn this study, we exclusively fed Styrofoam to T. molitor larvae and examined how this dietary change influence the gut’s bacterial community composition, as observed through fecal bacteria using bacterial 16S rRNA gene amplicon sequencing and the small-scale culturomics method with 20 types of anaerobic media under four different conditions.ResultsThe results revealed a significant shift in the dominant phylogroup from Lactococcus (37.8%) to Escherichia–Shigella (54.7%) when comparing the feces of larvae fed with bran and Styrofoam, as analyzing through the bacterial 16S rRNA gene amplicon sequencing. For small-scale culturomics method, a total of 226 strains of anaerobic bacteria were isolated and purified using the rolling-tube/strictly anaerobic technique. Among them, 226 strains were classified into 3 phyla, 7 classes, 9 orders, 17 families, 29 genera, 42 known species and 34 potential novel species.DiscussionInterestingly, 24 genera in total, identified through the culturomics method, were not found in the results obtained from amplicon sequencing. Here, we present a collection of culturable anaerobic bacteria from the feces of T. molitor larvae, which might be a promising avenue for investigating the biodegradability of plastics by combining specific strains, either randomly or intentionally, while considering the abundance ratio of the microbial community composition.

Abstract Background Contemporary data reflecting local pathogens and their antibiograms is necessary to select empirical antimicrobial therapy for equine neonates. Hypothesis/Objectives Describe bacterial isolates associated with equine neonatal infection and their antibiograms in the Midwestern United States. An increase in gram‐positive infection and antibiotic resistance compared to previous literature was expected. Animals Data from 149 fluid samples from 133 foals

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.

Lijuan Xiong,1,&ast; Xu Long,1,&ast; Lijun Ni,2,&ast; Lili Wang,2 Yang Zhang,1 Lili Cui,1 Jian Guo,2 Chunying Yang1 1Department of Laboratory Medicine, the Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guizhou, People’s Republic of China; 2Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Jian Guo, Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, No. 1800 Yuntai Road, Pudong New Area, Shanghai, People’s Republic of China, Tel +86-17701810639, Email guojian1110@126.com Chunying Yang, Department of Laboratory Medicine, the Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, No. 83 Feishan Street, Yunyan District, Guiyang City, Guizhou Province, People’s Republic of China, Tel +86-13658504875, Email 2590470591@qq.comPurpose: Matrix-assisted laser desorption-ionization-time of flight mass spectrometry (MALDI-TOF) has recently been widely used in clinical microbiology laboratories, with the advantages of being reliable, rapid, and cost-effective. Here, we reported the performance of two MALDI-TOF MS instruments, EXS3000 (Zybio, China) and Autof ms1000 (Autobio, China), which are commonly used in clinical microbiology field.Methods: A total of 209 common clinical common isolates, including 70 gram-negative bacteria strains, 58 gram-positive bacteria strains, 33 yeast strains, 15 anaerobic bacteria strains, and 33 mold strains, and 19 mycobacterial strains were tested. All strains were identified by EXS3000 (Zybio, China) and Autof ms1000 (Autobio, China). Sequence analysis of 16S rRNA or ITS regions was used to verify all strains.Results: Current study found that species-level discrimination was found to be 191 (91.39%) and 190 (90.91%) by EXS3000 and Autof ms1000, respectively. Genus-level discrimination was 205 (98.09%) by the EXS3000 and 205 (98.09%) by the Autof ms1000, respectively. The correct results at species level of the EXS3000 were 91.43% (64/70) for gram-negative bacteria, 93.1% (54/58) for gram-positive cocci, 93.94% (31/33) for yeast, 100% (15/15) for anaerobes and 81.82% (27/33) for filamentous fungi. The correct results at species level of the Autof ms1000 were 92.86% (65/70) for gram-negative bacteria, 91.38% (53/58) for gram-positive cocci, 93.94% (31/33) for yeast, 100% (15/15) for anaerobes and 78.79% (26/33) for filamentous fungi.Conclusion: Although the results show that the EXS3000 and Autof ms1000 systems are equally good choices in terms of analytical efficiency for routine procedures, the test result of EXS3000 is slightly better than Autof ms1000. It’s worth mentioning that the target plate of the EXS 3000 instrument is reusable, but the target plate of the Autof ms1000 is disposable, making the EXS3000 more effective in reducing costs.Keywords: evaluation, MALDI-TOF mass spectrometry, EXS3000, Autof ms1000, clinical isolates, identification, gram-negative bacteria, gram-positive bacteria, mycobacteria, yeast, anaerobic bacteria

The fermentation characteristics and microbial counts of Megathyrsus maximus ensiled at varying inclusions of Moringa oleifera seeds at different ensiling periods were investigated. Factorial experiment consisting of 3 varying proportions of grass and seeds (100:0, 75:25, and 50:50) and 4 ensiling duration (30, 60, 90, and 120 days) was carried out. The pH was significantly highest (p < 0.05) with the highest inclusion of seeds while pH decreased with increased ensiling duration. Colour and odour changed as the level of seed inclusion increased in the silage while the moisture content (9.10) was significantly higher (p < 0.05) at 30 days of ensiling. Ammonia nitrogen was highest at the highest level of seed inclusion while lactic acid was highest at 60 days of ensiling. Crude protein and tannin contents of the silage increased (p < 0.05) following the increased seed inclusion while there was a reduction as the ensiling duration increased. The total anaerobic bacteria count, total lactobacilli count, and total yeast count of the silage decreased following the increased inclusion of seeds in the silage. As the ensiling duration increased, a reduction in all the silage microbial counts was observed. Inclusion of 25 % of the seeds to 75 % of the grass for silage with ensiling up to 120 days supported improved fermentation characteristics, microbial and crude protein contents as well as a reduction in tannin content which implies that there will not be a detrimental effect on animals that feed on the silage.

The taxonomy of bacteria in the field of clinical microbiology is in a state of constant flux. A large-scale revamping of the classification and nomenclature of anaerobic bacteria has taken place over the past few decades, mainly due to advances in molecular techniques such as 16S rRNA and whole genome sequencing (WGS). New genera and species have been added, and existing genera and species have been reclassified or renamed. A major role of the clinical microbiological laboratories (CMLs) is the accurate identification (ID) and appropriate antimicrobial susceptibility testing (AST) for clinically important bacteria, and rapid reporting and communication of the same to the clinician. Taxonomic changes in anaerobic bacteria could potentially affect the choice of appropriate antimicrobial agents and the antimicrobial breakpoints to use. Furthermore, current taxonomy is important to prevent treatment failures of emerging pathogenic anaerobes with antimicrobial resistance. Therefore, CMLs should periodically update themselves on the changes in the taxonomy of anaerobic bacteria and suitably inform clinicians of these changes for optimum patient care. This article presents an update on the taxonomy of clinically important anaerobic bacteria, together with the previous names or synonyms. This taxonomy update can help guide antimicrobial therapy for anaerobic bacterial infections and prevent treatment failure and can be a useful tool for both CMLs and clinicians.

Abstract Background Faecal samples are frequently used to characterise the gut microbiota in health and disease, yet there is considerable debate about how representative faecal bacterial profiles are of the overall gut community. A particular concern is whether bacterial populations associated with the gut mucosa are properly represented in faecal samples, since these communities are considered critical in the aetiology of gastrointestinal diseases. In this study we compared the profiles of the faecal and mucosal microbiota from ten healthy volunteers using bacterial culturing (culturomics) and next-generation sequencing targeting the 16S ribosomal nucleic acid (rRNA) gene. Paired fresh rectal biopsies and faecal samples were processed under stringent anaerobic conditions to maintain the viability of the bacteria. Four different sample types were analysed: faecal (F), faecal homogenised (FHg), biopsy tissue (B) and biopsy wash (BW) samples. Results There were no significant statistical differences in either bacterial richness or diversity between biopsy washes (BW) and faecal (F) or faecal homogenised (FHg) samples. Principal coordinates analysis of a Bray–Curtis distance matrix generated from sequence variant tables did not show distinct clustering between these samples (PERMANOVA; p = 0.972) but showed strong clustering of samples from individual donors. However, the rectal biopsy tissue (B) samples had a significantly altered bacterial signature with greater abundance of Proteobacteria and Acidobacteria compared to faecal (F) and faecal homogenised (FHg) samples. A total of 528 bacteria encompassing 92 distinct bacterial species were isolated and cultured from a subset of six volunteer samples (biopsy washes and faeces). This included isolation of 22 novel bacterial species. There was significant similarity between the bacterial species grown in anaerobic culture and those identified by 16S rRNA gene sequencing (Spearman correlation; rho = 0.548, p = 0.001). Conclusion This study showed that the bacterial profiles of paired faecal and rectal biopsy wash samples were very similar, validating the use of faecal samples as a convenient surrogate for rectal biopsy-associated microbiota. Anaerobic bacterial culture results showed similar taxonomic patterns to the amplicon sequence analysis disproving the dogma that culture-based methods do not reflect findings of molecular assessments of gut bacterial composition. Video abstract

ABSTRACT Polyphenols are abundant in nature, and their anaerobic biodegradation by gut and soil bacteria is a topic of great interest. The O2 requirement of phenol oxidases is thought to explain the microbial inertness of phenolic compounds in anoxic environments, such as peatlands, termed the enzyme latch hypothesis. A caveat of this model is that certain phenols are known to be degraded by strict anaerobic bacteria, although the biochemical basis for this process is incompletely understood. Here, we report the discovery and characterization of a gene cluster in the environmental bacterium Clostridium scatologenes for the degradation phloroglucinol (1,3,5-trihydroxybenzene), a key intermediate in the anaerobic degradation of flavonoids and tannins, which constitute the most abundant polyphenols in nature. The gene cluster encodes the key C-C cleavage enzyme dihydrophloroglucinol cyclohydrolase, as well as (S)-3-hydroxy-5-oxo-hexanoate dehydrogenase and triacetate acetoacetate-lyase, which enable phloroglucinol to be utilized as a carbon and energy source. Bioinformatics studies revealed the presence of this gene cluster in phylogenetically and metabolically diverse gut and environmental bacteria, with potential impacts on human health and carbon preservation in peat soils and other anaerobic environmental niches. IMPORTANCE This study provides novel insights into the microbiota’s anaerobic metabolism of phloroglucinol, a critical intermediate in the degradation of polyphenols in plants. Elucidation of this anaerobic pathway reveals enzymatic mechanisms for the degradation of phloroglucinol into short-chain fatty acids and acetyl-CoA, which are used as a carbon and energy source for bacterium growth. Bioinformatics studies suggested the prevalence of this pathway in phylogenetically and metabolically diverse gut and environmental bacteria, with potential impacts on carbon preservation in peat soils and human gut health.

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial membrane lipids that are widely used in terrestrial paleoclimatic reconstructions. Recent studies have reported that brGDGTs can also be produced by marine bacteria. However, the environmental factors influencing marine-derived brGDGTs and their source organisms remain largely unknown. Here, we investigated the distribution and composition of brGDGTs and a suite of their putative derivatives called overly branched GDGTs (obGDGTs) in the Mariana Trench core sediments (water depth 8300 m, core length 320 cm), as well as the composition of bacterial communities. The ratio of the branched over isoprenoid tetraethers (BIT) was 0.03-0.21 (average 0.07; SD = 0.04; n = 21) and the ratio ΣIIIa/ΣIIa of brGDGTs was 0.93-7.47 (average 3.39; SD = 1.73; n = 21), which support the in situ production of brGDGTs. Co-occurrence network analysis revealed that a total of 33 types of bacteria at the order level (e.g., Armatimonadota DG-56, Proteobacteria Rhodospirillales, Chloroflexi SAR202_clade) were closely related to the distribution of brGDGTs and obGDGTs, which could be potential sources for these compounds. The abrupt increase in brGDGT and obGDGT concentrations in deeper oxygen-depleted sediments and their good correlations with anaerobic bacterial abundances suggest that these brGDGTs and obGDGTs may be produced by anaerobic bacteria residing in the anoxic sediments. Considerable variation in the degrees of methylation and cyclization of brGDGTs (obGDGTs) under different redox conditions indicate that sediment oxygen levels may have a profound impact on the presence and abundance of brGDGTs and obGDGTs, which should be considered when applying them for paleo-temperature or pH reconstructions. This study shows that brGDGTs and obGDGTs obtained from the Mariana Trench were probably produced by a variety of bacterial phyla indigenous in the hadal ocean, which are different from Acidobacteria commonly considered to be major terrestrial sources of brGDGTs.

Concern about salt levels in freshwater habitats receiving road de-icer runoff has inspired the development of “eco-friendly” formulations that are intended to be less toxic to aquatic organisms, but few experiments have determined that these products are environmentally benign. Mesocosms containing lake water were established for 6 weeks to compare traditional road salt with two newer de-icers, one an inorganic mixture of chloride salts and the second of beet extract and brine. Amplicon sequencing and algal blocking sequences facilitated the identification of differentially impacted bacterial taxa. Ironically, although there was only a minor effect on bacterial structure at high road-salt concentrations, there was an increased relative abundance of salt-resistant genera in the mixed-salt formulation. After amendment with the beet brine de-icer, there was a turnover of taxa coincident with a 68-fold decrease in dissolved oxygen, with decreased diversity and displacement by anaerobic genera indicating a shift across a threshold to a new, apparently stable state, suggesting mesocosm recovery was unlikely. Overall, although we applaud the sentiment behind the formulation of less-damaging “eco-friendly” de-icers, they appear to have more negative environmental impacts than the traditional road salt that they were made to replace.

Background and purpose: Transgenic rice is a type of rice that its genetic sequence has been changed to improve its quantity and quality. Bt (Bacillus thuringiensis) transgenic rice expresses Cry1Ab protein and is named Tarom Molaii. There are no studies on the effect of this type of transgenic rice on gastrointestinal health in Iran, so, this study investigated the effect of Tarom Molaii transgenic rice on common microbial flora of rat intestine. Materials and methods: In this experimental study, 24 Sprague Dawley (SD) rats received transgenic and non-transgenic rice in their diets for 90 days and were compared with the control group that received standard rat diet. The number of Escherichia coli, Bifidobacterium, Lactobacillus, and Enterococcus bacteria and the total number of aerobic and anaerobic bacteria in fecal samples were examined in jejunum, ileum, and duodenum samples on days 60, 90, and after killing the rats. Results: The study showed that except for the total number of anaerobic bacteria in the stool sample on day 90, there was no significant relationship between the study groups and the number of bacteria (P>0.05). There was an increase in the number of intestinal Lactobacillus in the transgenic rice-fed group and a decrease in the number of anaerobic bacteria in the transgenic rice-fed group compared with the control group and the non-transgenic rice-fed group. Conclusion: Consumption of transgenic rice in current study had no considerable effect on the number of common bacteria in the intestinal normal flora. But, long-term studies are needed in other laboratory animals.

Background: Anaerobes are recognized as important human pathogens causing severe life threatening exogenous and endogenous infection if left untreated. Anaerobes are one of the most neglected pathogens in various clinical samples due to the problem in sample handling, technical difficulties in their cultivation, and identification along with prolonged turnaround time. Aims and Objectives: The present study was undertaken to identify the different anaerobic organisms associated with deep seated abscess and their association with various risk. Materials and Methods: Pus and fluid sample collected in sterile syringe or swab stick were immediately put in RCM and taken to the laboratory. Gram staining, ZN stain, and culture--both aerobic and anaerobic were done. Obligate anaerobes were checked for aerotolerance. Subcultures were done for identification of species level by Gram stain, colony morphology, biochemical tests, and final identification that were done by the Vitek 2 system. Results: Out of the 170 samples, 144 (84.70%) were culture positive and the rest 26 (15.29%) were culture negative; 101 (70.1%) were aerobic, 23 (16%) anaerobes, and 20 (13.9%) mixed aerobic and anaerobic. A total of 51 obligate anaerobes were isolated from various samples. Out of which 32 (62.74 %) anaerobic Gram-positive cocci-Peptostreptococcus anaerobious being the most common and 13 (25.49%) anaerobic Gram-negative bacilli --Bacteroids fragilis being most common and 6 (11.76%) were anaerobic Gram-positive bacilli - Actinomyces meyeri being the most common. Diabetes mellitus was a significant associated factor. Maximum number of anaerobes was isolated from abscess over oral cavity followed by gangrenous foot, scrotal abscess, and diabetic foot. Conclusion: Anaerobes are an important cause of deep-seated abscess—mostly being polymicrobial in nature. Incision--drainage and proper antibiotic therapy is necessary for their early control and prevention of complications.

Introductıon: Deep neck infections are a group of diseases with serious complications and mortality, which can occur as a result of common diseases in the community and which have surgical and medical treatment options. Objectives: Patients ages, genders, complaints, physical examination findings, hospitalization complaints, history of antibiotic use before the application, additional diseases, radiological tests and analysis of examinations, type of treatment method, antibiotic agents selected in treatment, bacterial culture results, duration of hospitalization, complications, mortality rates were systematically recorded. In the study, anaerobic bacterial factors, which are difficult to produce in routine, were produced by considering special transport conditions and culture media. Methods: A total of 74 patients who were hospitalized in the Department of Otorhinolaryngology, University of Mersin, between 01.07.2016 and 01.07.2017 for deep neck infection were evaluated prospectively. The study included 37 female and 37 male patients. The ages of the patients ranged from 1 to 69 and the mean age was 31 years. Results: According to the analysis of the obtained data, there was a statistically significant relationship between the patients with additional diseases and the treatment modalities of the patients (p = 0.017). The surgical treatment rate was increased in this group of patients. In patients with a history of antibiotic use, it was found that patients in the pediatric group were in hospital longer in terms of length of stay compared to adults (p = 0.036). In adult patients who underwent surgery, the absorptive long axis was found to be longer in mm than in patients receiving isolated medical treatment (p = 0.008). Conclusions: Deep neck infections is a disease group that seriously concerns public health, with significant mortality and morbidity. Ensuring airway safety of patients should be the first intervention. Abscesses located lateral to the tonsil capsule may not drain adequately without concomitant tonsillectomy.

Peritoneal dialysis-related peritonitis is a common complication of patients receiving peritoneal dialysis. However, peritonitis caused by anaerobic infection is rare. This article was reported a 44-year-old female patient who had undergone maintenance peritoneal dialysis for more than 4 years. She was admitted due to abdominal pain, diarrhea, and turbid peritoneal fluid after being diagnosed with peritoneal dialysis-related peritonitis. Repeated peritoneal fluid culture tests yielded negative results. After ineffective anti-infection treatment, the possibility of peritoneal dialysis-related refractory peritonitis was considered. Metagenomic next-generation sequencing （mNGS） pathogenic examination revealed the presence of Bacteroides thetaiotaomicron infection. She was recovered and discharged after combined use of metronidazole combined with imipenem and cilastatin sodium for 18 d. No recurrence of peritonitis was observed during follow-up. The diagnosis and treatment of this case prompt that attention should be paid to peritoneal dialysis-related peritonitis caused by anaerobic bacterial infection. mNGS can be applied in the routine examination of peritoneal dialysis-related peritonitis, aiming to improve the detection rate of pathogenic microorganisms, promptly select appropriate antibiotics for anti-infection therapy and enhance clinical prognosis of patients.

Fecal microbiota transplantation (FMT) is under investigation for several indications, including ulcerative colitis (UC). The clinical success of FMT depends partly on the engraftment of viable bacteria. Because the vast majority of human gut microbiota consists of anaerobes, the currently used aerobic processing protocols of donor stool may diminish the bacterial viability of transplanted material. This study assessed the effect of four processing techniques for donor stool (i.e., anaerobic and aerobic, both direct processing and after temporary cool storage) on bacterial viability. By combining anaerobic culturing on customized media for anaerobes with 16S rRNA sequencing, we could successfully culture and identify the majority of the bacteria present in raw fecal suspensions. We show that direct anaerobic processing of donor stool is superior to aerobic processing conditions for preserving the bacterial viability of obligate anaerobes and butyrate-producing bacteria related to the clinical response to FMT in ulcerative colitis patients, including Faecalibacterium, Eubacterium hallii, and Blautia. The effect of oxygen exposure during stool processing decreased when the samples were stored long-term. Our results confirm the importance of sample conditioning to preserve the bacterial viability of oxygen-sensitive gut bacteria. Anaerobic processing of donor stool may lead to increased clinical success of FMT, which should further be investigated in clinical trials.

Background: Chronic Periodontitis (CP) and Aggressive Periodontitis (AP) are chronic inflammation diseases in the dental supporting tissues characterized by the existence of pocket inside, alveolar bone attachments and damages rapidly leading to the dental loss. The pocket inside is related to the existence of the dominating bacteria known as the black-pigmented anaerobic bacteria group. This black-pigmented bacteria group consists of Porphyromonas spp and Prevotella spp genus abundantly found in the periodontal pocket. This research aims at examining the number of black-pigmented bacteria taken from the Gingival Crevicular Fluid (GCF) of patients suffering from the Chronic Periodontitis (CP) and Aggressive Periodontitis (AP). Method: The ethical clearance was obtained from the Faculty of Dentistry, Universitas Jember. The subjects diagnosed with the Chronic Periodontitis (CP) and Aggressive Periodontitis were recorded into pocket and then the panoramic Rontgen photographs were taken. The Gingival Crevicular Fluid (GCF) of patients were taken using a sterile paper point and then inserted to the pocket inside for 30 seconds. The paper point was then inserted to the PBS and examined using a microbiological test on blood agar media. The mouth cavity hygiene levels of subjects were recorded using OHI-S, while the needs on periodontal treatments using CPITN. The statistical test was conducted using T-test with the value of p0.05). this shows the same periodontal disease severity of both Chronic Periodontitis (CP) and Aggressive Periodontitis (AP). The bacteria culture result shows that the number of black- pigmented anaerobic bacteria in both Chronic Periodontitis (CP) and Aggressive Periodontitis (AP) was not significant (p>0.05). The mouth hygiene level of patients suffering from the Chronic Periodontitis (CP) and Aggressive Periodontitis (AP) was at the medium (93%) level with the needs on periodontal treatments of scaling and root planning (85%) Conclusion: The number of black-pigmented anaerobic bacteria colonies belonging to the patients suffering from the Chronic Periodontitis (CP) and Aggressive Periodontitis (AP) was same.

Background and Objectives: Anaerobic infections are usually caused by the host’s endogenous flora due to a breach in the anatomical barriers and Bacteroides spp. are the most notorious organisms associated with anaerobic infections. The identification of anaerobes has been a challenge since times. MALDI-TOF-MS is a boon for aiding the rapid detection of anaerobic organisms and has helped us to enlist the distribution of various anaerobic pathogens. Materials and Methods: This retrospective analysis (January 2018 to December 2019) was carried out in a tertiary care hospital in North India, in which the anaerobic microbiological profile of all patients admitted to surgical wards, ICU, and OPD of various departments (Orthopedics, Surgery, Gynecology, and Obstetrics) was reviewed. Samples received were immediately processed aerobically (5% sheep blood agar and Mac Conkeyagar) as well as anaerobically (RCM and freshly prepared sheep blood agar) as per the laboratory protocols. Results: Bacteroides fragilis (19.12%) was the most common anaerobe whereas among aerobes Escherichia coli (30.2%) followed by Klebsiella pneumoniae (10.34%) were most commonly isolated. The majority of patients were males (56%) and the most common presentation was with abscesses (21.4%). Polymicrobial infections (69.51%) outnumbered monomicrobial ones (30.48%). Conclusion: There is a paucity of literature on anaerobe isolation from surgical infections from our country which motivated us to study anaerobic infections and the high sample size in our institute enabled us to study surgical infections from an anaerobic perspective. This will add to the knowledge of microbiologists and clinicians. MALDI-TOF MS helped in rapid and accurate identification and hence we could report a wider spectrum of organisms in our study.

The composition of the gut microbiota oscillates according to the light–dark cycle. However, the existing literature demonstrates these oscillations only by molecular methods. Microbial cultures are an interesting method for studying metabolically active microorganisms. In this work, we aimed to understand the diurnal oscillation of the intestinal microbiota in Wistar male rats through microbial culture analysis. Over a 24 h period, three animals were euthanized every 6 h. Intestinal segments were dissected immediately after euthanasia and diluted in phosphate-buffered saline (PBS) for plating in different culture media. The CFU/mL counts in feces samples cultured in the Brucella medium were significantly higher at ZT0, followed by ZT6, ZT18, and ZT12 (p = 0.0156), which demonstrated the diurnal oscillation of metabolically active anaerobic bacteria every 6 h using microbial culture. In addition, quantitative differences were demonstrated in anaerobic bacteria and fungi in different gastrointestinal tract tissues.

Abstract Background Managing surgical site infections, with negative culture report in routine diagnosis is a common dilemma in microbiology accounting more than 30% worldwide. The present study attempted to identify the presence of bacterial spp. if any in wound aspirates/swabs of culture negative surgical site infections of hospitalised patients using molecular tools. Methods Ninety-seven patients with post-operative SSI whose wound swabs/aspirate were negative in the conventional aerobic culture after 72 h of incubation were analysed by 16S rRNA gene specific broad range PCR. The amplified DNA fragments were sequenced by Sanger DNA sequencing method and homology of the sequence were matched using NCBI BLAST (NCBI, USA) Results Of the 97 patients, 16S rRNA based broad range PCR assay could identify the presence of bacterial pathogen in 53(54.63%) cases, of which 29 isolates were supposed to be of viable but non-culturable bacteria (VBNC), 07 were of obligatory anaerobes and 13 were of unculturable bacteria, 04 were with poly bacterial infections. Conclusions Our study highlights the usefulness of PCR assay in detecting the presence of any VBNC, anaerobes and unculturable bacteria in SSI patients regardless of how well the bacteria may or may not grow in culture. Measures should be taken to use anaerobic culture system and PCR diagnosis along with conventional culture to detect the VBNC and unculturable bacteria where Gram stain is positive for better patient care.

Aim: The study aimed at comparing the antimicrobial activity of mycelium and spore of Ganoderma lucidum on Prevotella intermedia isolated from subgingival plaque of chronic periodontitis patients. Settings and Design: Written informed consent was obtained from each subject enrolled in the study. The institutional ethics committee granted ethical clearance for the study. Materials and Methods: Twenty patients diagnosed with chronic periodontitis were included in the study. Using sterile curettes, pooled subgingival plaque samples were collected from the deepest sites of periodontal pockets. The collected samples were then transported in 1 mL of reduced transport fluid. The organisms were cultured and confirmed and were used for the minimum inhibitory concentration (MIC) procedure. Statistical Analysis: Mean of the MIC value obtained was calculated. Comparison between the antimicrobial activity of mycelium and spore against P. intermedia groups with respect to mean MIC value (in mcg/ml) was done by Mann–Whitney U test. Comparison of antimicrobial activity of mycelium and spores of G. lucidum against P. intermedia expressed by the MIC value at different concentrations was done by Chi-square test. Results: The mean MIC obtained for mycelium was 5.64 mcg/ml. The mean MIC obtained for spore was 3.62 mcg/ml. Results of the comparison of antimicrobial activity implied that the antimicrobial activity of mycelium and spore of G. lucidum was comparable. Conclusions: Both mycelium and spore of G. lucidum with its bioactivity could be used as an antimicrobial, in combination with conventional therapy in periodontal disease.

Sheep farms produce waste in the form of feces and urine that are organic materials and the source of bacteria. This study aims to determine the potential of bacteria in sheep feces when used as a starter for biogas formation (the number of anaerobic bacteria and biogas production) on lignite coal media. The method used in this study was experimental in the laboratory using a completely randomized design with four treatments and four replications. The data were analyzed using analysis of variance, and Duncan test was performed to find out the differences between treatments. The research procedure was divided into two stages. The first stage was in vitro method to select the feces sample with the largest biogas production. The second stage was utilizing enriched media (media 98-5) liquid for observing the growth of bacteria originating from selected sheep feces, and then the bacteria consortium was used as starters on lignite coal media. The treatments were based on the concentration of bacteria consortium used, T1=0%, T2=1.5%, T3=3%, and T4=4.5%. The number of anaerobic bacteria was observed in Hungate tubes, and biogas production was observed in serum bottles. The results showed that the highest number of anaerobic bacteria (1012 CFU/ml) and the highest biogas production (105 mL) were achieved at T2=1.5%. Bacteria in sheep feces can be potentially used as a biogas forming agent on lignite coal media, which is proved by the growth of anaerobic bacteria and the biogas production from present study.

Abstract Background Capture and storage of the energy carrier hydrogen as well as of the greenhouse gas carbon dioxide are two major problems that mankind faces currently. Chemical catalysts have been developed, but only recently a group of anaerobic bacteria that convert hydrogen and carbon dioxide to acetate, formate, or biofuels such as ethanol has come into focus, the acetogenic bacteria. These biocatalysts produce the liquid organic hydrogen carrier formic acid from H2 + CO2 or even carbon monoxide with highest rates ever reported. The autotrophic, hydrogen-oxidizing, and CO2-reducing acetogens have in common a specialized metabolism to catalyze CO2 reduction, the Wood–Ljungdahl pathway (WLP). The WLP does not yield net ATP, but is hooked up to a membrane-bound respiratory chain that enables ATP synthesis coupled to CO2 fixation. The nature of the respiratory enzyme has been an enigma since the discovery of these bacteria and has been unraveled in this study. Results We have produced a His-tagged variant of the ferredoxin:NAD oxidoreductase (Rnf complex) from the model acetogen Acetobacterium woodii, solubilized the enzyme from the cytoplasmic membrane, and purified it by Ni2+–NTA affinity chromatography. The enzyme was incorporated into artificial liposomes and catalyzed Na+ transport coupled to ferredoxin-dependent NAD reduction. Our results using the purified enzyme do not only verify that the Rnf complex from A. woodii is Na+-dependent, they also demonstrate for the first time that this membrane-embedded molecular engine creates a Na+ gradient across the membrane of A. woodii which can be used for ATP synthesis. Discussion We present a protocol for homologous production and purification for an Rnf complex. The enzyme catalyzed electron-transfer driven Na+ export and, thus, our studies provided the long-awaited biochemical proof that the Rnf complex is a respiratory enzyme.

Introduction and objective Anaerobic bacteria are a component of the human microbiome. Many of them are characterized by low pathogenicity, but some may cause opportunistic and polybacterial infections. Some species are absolutely pathogenic. The aim of the study is to show the problems that may appear at any stage of microbiological testing with the participation of anaerobic bacteria. State of knowledge Due to technical difficulties and the cost of the test, microbiological diagnostics of anaerobic bacteria is usually carried out in only a few microbial laboratories. The skipping of diagnoses of these bacteria in routine microbiological testing results in an underestimation of their involvement in the etiology of infections, and makes the monitoring of antibiotic resistance impossible. Among anaerobes strains resistant to clindamycin, beta-lactam antibiotics combined with a beta-lactamase inhibitor and carbapenems, are especially often isolated. The problem of resistance mainly concerns anaerobic Gram-negative rods. Conclusion The appropriate procedure, from the stage of sample qualification to the interpretation of the obtained outcome, exerts an effect on the reliability of the result, and significantly reduces the cost associated with the isolation and identification of anaerobic bacteria. Microbiological determination of drug susceptibility of anaerobic bacteria also allows assessment of resistance trends, establishing the principles of empirical therapy, and the creation of appropriate antibiotic policy in the hospital.

Jie Jiang,1,2,* Bo She,3,4,* Rui Zheng1,2 1Department of Clinical Laboratory, The First People’s Hospital of Yunnan Province, Kunming, Yunnan, People’s Republic of China; 2Department of Clinical Laboratory, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, Yunnan, People’s Republic of China; 3PET/CT Center, The First People’s Hospital of Yunnan Province, Kunming, Yunnan, People’s Republic of China; 4PET/CT Center, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, Yunnan, People’s Republic of China*These authors contributed equally to this workCorrespondence: Rui Zheng Tel +86-0871-63638430Email ynkmzheng@gmail.comAbstract: Eggerthella lenta is part of the normal bacterial flora of the intestinal tract, but may cause life-threatening infections. E. lenta has been isolated from blood, abscesses, wounds, skin ulcers, and intra-abdominal infections. However, due to historical difficulties with laboratory identification by conventional biochemical methods, some cases of E. lenta infection have previously gone undiagnosed, especially in China where E. lenta infections are very rare. Recently, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), a new type of technology, has made it possible to identify E. lenta. We report a case of postoperative infection caused by E. lenta which was treated successfully using meropenem.Keywords: Eggerthella lenta, MALDI-TOF, intra-abdominal abscess, bloodstream infection, anaerobic bacteria

Aim:Sodium hypochlorite, though considered an ideal root canal irrigant, cannot be used at required concentrations in children, due to its undesirable effects. Hence, it is imperative to search for an ideal root canal irrigant to avoid these undesirable effects which we hope to achieve with this study. The antimicrobial efficacy of aqueous ozone, green tea, and normal saline as irrigants in pulpectomy procedures of the primary teeth has been compared. Materials and Methods: Sixty patients between 4 and 8 years of age with a single-rooted deciduous tooth indicated for pulpectomy were included. The infected teeth were randomly allocated to one of the three treatment groups based on the irrigating agents used, namely normal saline, green tea extract, or ozonated water. Specimens for anaerobic culture were collected three times from the teeth: before irrigation, after initial irrigation, and on the 3rd day after final irrigation. Results and Conclusion: Mean colony forming unit (CFU) count after both initial and final irrigation with ozonated water was significantly lower when compared with green tea and normal saline. Further, it was observed that the mean CFU count with green tea was significantly lower than the counts obtained with normal saline on the 3rd day after final irrigation. Hence, both ozonated water and green tea could be considered a good alternative to conventional root canal irrigants in the primary teeth. Larger sample sizes with a larger variety of irrigants are recommended.

Context: RJ is a natural bee product and is known to have remarkable health benefits. The objective was to evaluate its antimicrobial potential against periodontopathic bacteria and compare the same with chlorhexidine. Aims: The aim was to evaluate and compare the antimicrobial activity of royal jelly (RJ) with chlorhexidine against the periodontopathic bacteria (aerobic and anaerobic) in subgingival plaque. Materials and Methods: Subgingival plaque samples of 15 chronic periodontitis patients were taken, and clinical parameters were evaluated. Inhibitory effect of RJ and chlorhexidine was investigated “in vitro” on the growth of aerobic and anaerobic bacteria by colony count, minimum inhibitory concentration, and minimum bactericidal concentration (MBC) by the method of serial broth dilution. Statistical Analysis Used: ANOVA statistical analysis was used in this study. Results: Subgingival anaerobic bacteria predominate (colony-forming unit). Chlorhexidine is more sensitive in inhibiting aerobic and anaerobic bacteria (at concentration 50 μg/100 μl). A higher concentration of RJ is required to have an inhibitory effect. MBC of chlorhexidine shows no growth on blood agar plates, whereas minimum bacterial growth is seen around the RJ. Conclusions: Chlorhexidine (gold standard) has a higher inhibitory effect in the case of chronic periodontitis; however, RJ can also be used as an alternative but at higher concentration and lesser dilution. Evaluation of the quality, quantity and the biological activity of RJ is a necessity and must be done before its “in vivo” application.

Background and Objectives: Anaerobic bacteria are a common cause of endogenous infections, some of which can be life threatening. These bacteria are not easily cultured and isolated and often cannot even found from infected sites. Delayed or inappropriate treatment of these microorganisms can lead to failure in eradicating these infections. The purpose of this study was to determine the diversity of anaerobic bacteria at present and their pattern of sensitivity to several antibiotics. Materials and Methods: A retrospective study was conducted over a period of two years on various specimens. Specimens derived from body fluids are inoculated on a BacT/Alert (bioMérieux). Anaerobic isolates were identified by Gram staining and continued identification using Vitek 2® automated system. Antibiotic sensitivity examination was carried out using ATBTM ANA (bioMérieux). Results: A total of 440 specimens were received in microbiology laboratory for anaerobic culture from patients with multiple infections from 13 hospitals in Jakarta. Our research was able to identify 18 species on anaerobic bacteria, consisting 52.5% Gram positive and 47.5% Gram negative bacteria. The most common bacteria found were Clostridium perfringens (15%) from Gram positive and Provetella bivia (10%) from Gram negative. The sensitivity pattern shows that antibiotic piperacilline-tazobactam is 100% effective against anaerobic bacteria, while metronidazole as the drug of choice is only 75% effective. Against Gram positive, several antibiotics such as piperacilline-tazobactam, ticarcilin-clavunic acid, cefoxitin, cefotetan, imipenem and chloramphenicol were 100% effective, however metronidazole occupied the lowest position (61.9%). Meanwhile against Gram negative antibiotics piperacilline-tazobactam is 100% effective and chloramphenicol in the second position (94.75%). Conclusion: Clostridium perfringens and Provetella bivia are the most common bacteria found. The antibiotics piperacilline-tazobactam is 100% effective against both Gram positive and negative. The accuracy of specimen management, isolation, identification and sensitivity examination will determine the successful microbiological investigations.

Bacterial Vaginosis (BV) involves the presence of a multi-species biofilm adhered to vaginal epithelial cells, but its in-depth study has been limited due to the complexity of the bacterial community, which makes the design of in vitro models challenging. Perhaps the most common experimental technique to quantify biofilms is the crystal violet (CV) staining method. Despite its widespread utilization, the CV method is not without flaws. While biofilm CV quantification within the same strain in different conditions is normally accepted, assessing multi-species biofilms formation by CV staining might provide significant bias. For BV research, determining possible synergism or antagonism between species is a fundamental step for assessing the roles of individual species in BV development. Herein, we provide our perspective on how CV fails to properly quantify an in vitro triple-species biofilm composed of Gardnerella vaginalis, Fannyhessea (Atopobium) vaginae, and Prevotella bivia, three common BV-associated bacteria thought to play key roles in incident BV pathogenesis. We compared the CV method with total colony forming units (CFU) and fluorescence microscopy cell count methods. Not surprisingly, when comparing single-species biofilms, the relationship between biofilm biomass, total number of cells, and total cultivable cells was very different between each tested method, and also varied with the time of incubation. Thus, despite its wide utilization for single-species biofilm quantification, the CV method should not be considered for accurate quantification of multi-species biofilms in BV pathogenesis research.

Prevotella is recognized as one of the core anaerobic genera in the oral microbiome. In addition, members of this genus belong to microbial communities of the gastrointestinal and respiratory tracts. Several novel Prevotella species, most of them of oral origin, have been described, but limited knowledge is still available of their clinical relevance. Prevotella melaninogenica is among the anaerobic commensals on oral mucosae from early months of life onward, and other early colonizing Prevotella species in the oral cavity include Prevotella nigrescens and Prevotella pallens. Oral Prevotella species get constant access to the gastrointestinal tract via saliva swallowing and to lower airways via microaspiration. At these extra-oral sites, they play a role as commensals but also as potentially harmful agents on mucosal surfaces. The aim of this narrative review is to give an updated overview on the involvement of oral Prevotella species in gastrointestinal and respiratory health and disease.

This work focused on the metabolomic profiling of the conditioned medium (FS03CM) produced by an anaerobic bacterium closely related to Terrisporobacter spp. to identify potential antimicrobial metabolites. The metabolome of the conditioned medium was profiled by two-channel Chemical Isotope Labelling (CIL) LC-MS. The detected metabolites were identified or matched by conducting a library search using different confidence levels. Forty-eight significantly changed metabolites were identified with high confidence after the growth of isolate FS03 in cooked meat glucose starch (CMGS) medium. Some of the secondary metabolites identified with known antimicrobial activities were 4-hydroxyphenyllactate, 3-hydroxyphenylacetic acid, acetic acid, isobutyric acid, valeric acid, and tryptamine. Our findings revealed the presence of different secondary metabolites with previously reported antimicrobial activities and suggested the capability of producing antimicrobial metabolites by the anaerobic bacterium FS03.