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Objective: This study aimed to evaluate antibiotic susceptibility and antimicrobial resistance trends among clinically significant anaerobes in Kuwait hospitals from 2013 to 2022, comparing these findings with data from 2002 to 2012. Methods: The study prospectively collected 2,317 anaerobic isolates from various body sites across four Kuwaiti hospitals between January 2013 and December 2022. The minimum inhibitory concentrations for 11 antianaerobic antibiotics were determined using E-test methodology. The study analyzed trends and resistance rates across two periods: 2013-2017 and 2018-2022, using statistical analysis for resistance comparison. Results: Of the 2,317 isolates, most were from wounds (42.2%), fluids (28.0%), and tissues (20.5%). Bacteroides fragilis was the most common pathogen (34.0%), followed by Prevotella bivia (13.4%). Over 90% of isolates were susceptible to imipenem, meropenem, tigecycline, and metronidazole, whereas lower susceptibility was observed for penicillin, amoxicillin-clavulanic acid, and clindamycin. Notable differences in resistance profiles since 2002 were observed, especially in amoxicillin-clavulanic acid, piperacillin, piperacillin-tazobactam, and clindamycin. Conclusion: Owing to detected resistance to all antibiotics, susceptibility testing for anaerobic isolates is recommended in severe infections to ensure effective antimicrobial therapy. Continuous surveillance is crucial for developing antibiotic policies to manage invasive anaerobic infections.
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Antibacterianos , Bacterias Anaerobias , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Bacterias Anaerobias/efectos de los fármacos , Kuwait/epidemiología , Humanos , Estudios Prospectivos , Tigeciclina/farmacología , Farmacorresistencia Bacteriana , Bacteroides fragilis/efectos de los fármacos , Bacteroides fragilis/aislamiento & purificación , Metronidazol/farmacología , Metronidazol/uso terapéuticoRESUMEN
Dysbiosis within microbiomes has been increasingly implicated in many systemic illnesses, such as cardiovascular disease, metabolic syndrome, respiratory infections, and Alzheimer disease (Ad). The correlation between Ad and microbial dysbiosis has been repeatedly shown, yet the etiologic cause of microbial dysbiosis remains elusive. From a neuropathology perspective, abnormal (often age-related) changes in the brain, associated structures, and bodily lumens tend toward an accumulation of oxygen-depleted pathologic structures, which are anaerobically selective niches. These anaerobic environments may promote progressive change in the microbial community proximal to the brain and thus deserve further investigation. In this review, we identify and explore what is known about the anaerobic niche near or associated with the brain and the anaerobes that it is harbors. We identify the anaerobe stakeholders within microbiome communities and the impacts on the neurodegenerative processes associated with Ad. Chronic oral dysbiosis in anaerobic dental pockets and the composition of the gut microbiota from fecal stool are the 2 largest anaerobic niche sources of bacterial transference to the brain. At the blood-brain barrier, cerebral atherosclerotic plaques are predominated by anaerobic species intimately associated with the brain vasculature. Focal cerebritis/brain abscess and corpora amylacea may also establish chronic anaerobic niches in direct proximity to brain parenchyma. In exploring the anaerobic niche proximal to the brain, we identify research opportunities to explore potential sources of microbial dysbiosis associated with Ad.
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Enfermedad de Alzheimer , Bacterias Anaerobias , Encéfalo , Disbiosis , Microbioma Gastrointestinal , Humanos , Enfermedad de Alzheimer/microbiología , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/etiología , Disbiosis/microbiología , Bacterias Anaerobias/patogenicidad , Encéfalo/patología , Encéfalo/microbiología , Barrera Hematoencefálica/microbiología , MicrobiotaRESUMEN
BACKGROUND: Managing infectious complications after kidney transplantation (KT) remains a major challenge. Infections are the leading non-cardiovascular cause of death among kidney transplant recipients (KTr). The urinary tract is particularly vulnerable to infections in this group, leading to high levels of morbidity and mortality, as well as significant economic costs. CASE PRESENTATION: This case report presents the first documented instance of extensive thigh pyomyositis resulting from cystic fistulae in an 84-year-old KTr. The patient was referred to our hospital with acute onset fever, pain in the inner thighs and pyuria. A CT scan revealed bilateral pyomyositis of the thighs, characterized by multiple abscesses in the adductor muscles and hydroaerobic levels. Additionally, cystic fistulae complicated by pubic symphysis osteitis were identified. CONCLUSION: In KTr, lower limb pyomyositis resulting from a urinary tract infection is an extremely rare and significantly worsens the overall prognosis for these patients.
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Trasplante de Riñón , Piomiositis , Muslo , Humanos , Piomiositis/microbiología , Trasplante de Riñón/efectos adversos , Muslo/patología , Masculino , Anciano de 80 o más Años , Bacterias Anaerobias/aislamiento & purificación , Infecciones Urinarias/microbiología , Infecciones Urinarias/complicaciones , Receptores de Trasplantes , Tomografía Computarizada por Rayos X , Infecciones Bacterianas/microbiología , Fístula/etiologíaRESUMEN
OBJECTIVES: Bacteremia with anaerobic bacteria is generally a marker of severe prognosis. However, population-based data is lacking. Our aim was to describe the epidemiology and the 30-day mortality rate of anaerobic bacteremia in a Danish population-based setting. METHODS: In this population-based cohort study, all first-time episodes of anaerobic bacteremia from the North Denmark Bacteremia Research Database during 1994-2019 were identified. Information on comorbidities, discharge diagnoses, and mortality was retrieved. 30-day mortality rates were calculated and a multivariate logistic regression analysis to identify risk factors for death was performed. RESULTS: 1750 episodes with anaerobic bacteremia were identified, corresponding to an incidence rate of 12.5 per 100,000 inhabitants (increasing from 11.2 in 1994-2014 to 17.7 in 2015-2019). Of these episodes, a third were polymicrobial, and the majority (70 %) of patients had one or more comorbid conditions. Abdominal infection was the source of bacteremia in 61 % of patients, while it was unknown for 15 %. The most frequently isolated genera were Bacteroides (45 %), Clostridium (20 %) and Fusobacterium (6 %). The overall crude 30-day mortality rate was 27 %, but rates were even higher for patients of high age, with liver disease, and solid tumors. The odds ratio (OR) for 30-day mortality was 1.32 for Clostridium species, and 1.27 for polymicrobial bacteremia with aerobic bacteria. CONCLUSIONS: The incidence rate of anaerobic bacteremia increased, and the 30-day mortality rate remained high during the study period. Multiple factors influence 30-day mortality rates, including high age, liver disease, solid tumor, polymicrobial bacteremia, and bacteremia with Clostridium species.
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Bacteriemia , Bacterias Anaerobias , Humanos , Bacteriemia/epidemiología , Bacteriemia/microbiología , Bacteriemia/mortalidad , Dinamarca/epidemiología , Masculino , Femenino , Anciano , Bacterias Anaerobias/clasificación , Bacterias Anaerobias/aislamiento & purificación , Persona de Mediana Edad , Estudios de Cohortes , Anciano de 80 o más Años , Adulto , Factores de Riesgo , Incidencia , Adulto Joven , Adolescente , Comorbilidad , Clostridium/aislamiento & purificación , Clostridium/clasificaciónRESUMEN
Oxygen tolerance of anaerobes is a virulence factor, but can also be a beneficial property. Many species have evolved to tolerate or take advantage of the presence of low, especially nanaerobic (≤0.14 %) oxygen concentrations. Oxygen tolerance is genus-, species- and strain-dependent according to their protective mechanisms. It was better expressed in some pathogenic species such as Bacteroides fragilis, Clostridioides difficile, and Clostridium perfringens, as well as in Akkermansia muciniphila than in other potential probiotics such as Alistipes, Blautia and Roseburia spp. Different degrees of oxygen sensitivity were found between the strains of Anaerostipes, Faecalibacterium, and Bifidobacterium spp. Importantly, clostridial spores and anaerobes in biofilms are protected from oxidation. Rubrerythrins and flavodiiron proteins and two regulators (sigma factor B and PerR) contribute to C. difficile protection from reactive oxygen species (ROS). The frequent pathogen, B. fragilis, has numerous protective factors such as enzymes (catalase, superoxide dismutase, alkyl hydroperoxidase, thioredoxin peroxidase, and aerobic-type NrdAB ribonucleotide reductase), and nanaerobic respiration. Seven proteins confer strain-specific oxygen adaptation of Faecalibacterium prausnitzii. Oxygen tolerance protects anaerobes from ROS, shields their DNA and modulates gene expression. Furthermore, oxygen can induce mutations leading to antibiotic resistance as shown in Prevotella melaninogenica. Some Faecalibacterium, Anaerostipes, Bifidobacterium, and Akkermansia strains from the intestinal microbiota exhibiting oxygen tolerance may become next-generation probiotic candidates. Further studies are needed to reveal oxygen effects on more anaerobic species and strains, and the influence of oxygen on antibiotic resistance. More studies on oxygen-tolerant probiotic strains can be useful to optimize biotechnological methods.
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Bacterias Anaerobias , Oxígeno , Factores de Virulencia , Factores de Virulencia/genética , Factores de Virulencia/metabolismo , Oxígeno/metabolismo , Humanos , Bacterias Anaerobias/genética , Bacterias Anaerobias/metabolismo , Anaerobiosis , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , AnimalesRESUMEN
Microbial lipids, used as taxonomic markers and physiological indicators, have mainly been studied through cultivation. However, this approach is limited due to the scarcity of cultures of environmental microbes, thereby restricting insights into the diversity of lipids and their ecological roles. Addressing this limitation, here we apply metalipidomics combined with metagenomics in the Black Sea, classifying and tentatively identifying 1623 lipid-like species across 18 lipid classes. We discovered over 200 novel, abundant, and structurally diverse sphingolipids in euxinic waters, including unique 1-deoxysphingolipids with long-chain fatty acids and sulfur-containing groups. Sphingolipids were thought to be rare in bacteria and their molecular and ecological functions in bacterial membranes remain elusive. However, genomic analysis focused on sphingolipid biosynthesis genes revealed that members of 38 bacterial phyla in the Black Sea can synthesize sphingolipids, representing a 4-fold increase from previously known capabilities and accounting for up to 25% of the microbial community. These sphingolipids appear to be involved in oxidative stress response, cell wall remodeling, and are associated with the metabolism of nitrogen-containing molecules. Our findings underscore the effectiveness of multi-omics approaches in exploring microbial chemical ecology.
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Organismos Acuáticos , Bacterias Anaerobias , Esfingolípidos , Esfingolípidos/biosíntesis , Esfingolípidos/química , Esfingolípidos/genética , Bacterias Anaerobias/clasificación , Bacterias Anaerobias/genética , Bacterias Anaerobias/metabolismo , Organismos Acuáticos/clasificación , Organismos Acuáticos/genética , Organismos Acuáticos/metabolismo , Océanos y Mares , Microbiología del Agua , Genoma Bacteriano/genéticaRESUMEN
The gut microbiome is a dense and diverse community of different microorganisms that deeply influence human physiology and that have important interactions with pathogens. For the correct antibiotic treatment of infections, with its twin goals of effective inhibition of the pathogen and limitation of collateral damage to the microbiome, the identification of infectious organisms is key. Microbiological culturing is still the mainstay of pathogen identification, and anaerobic species are among the most demanding bacterial communities to culture. This study aimed to evaluate the impact of growth media on the culture of an-aerobic bacteria from human stool samples. Stool samples from eight human subjects were cultured each on a yeast extract cysteine blood agar (HCB) and a modified peptone-yeast extract-glucose (MPYG) plate and subjected to Illumina NGS analysis after DNA extraction and amplification. The results showed tight clustering of sequencing samples belonging to the same human subject. Various differences in bacterial richness and evenness could be observed between the two media, with HCB plates supporting the growth of a more diverse microbial community, and MPYG plates improving the growth rates of certain taxa. No statistical significance was observed between the groups. This study highlights the importance of choosing the appropriate growth media for anaerobic bacterial culture and adjusting culture conditions to target specific pathological conditions. HCB plates are suitable for standard microbiological diagnostics, while MPYG plates may be more appropriate for targeting specific conditions. This work emphasizes the role of next-generation sequencing in supporting future research in clinical microbiology.
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Bacterias Anaerobias , Medios de Cultivo , ADN Bacteriano , Heces , Microbioma Gastrointestinal , ARN Ribosómico 16S , Humanos , Medios de Cultivo/química , ARN Ribosómico 16S/genética , Heces/microbiología , Bacterias Anaerobias/genética , Bacterias Anaerobias/aislamiento & purificación , Bacterias Anaerobias/clasificación , Bacterias Anaerobias/crecimiento & desarrollo , ADN Bacteriano/genética , ADN Ribosómico/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Análisis de Secuencia de ADN/métodos , Biodiversidad , Bacterias/genética , Bacterias/clasificación , Bacterias/aislamiento & purificación , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrolloRESUMEN
Anaerobic bacteria can cause many infections in children. Because they predominant in the normal human skin and mucous membranes bacterial flora, they are often associated with bacterial infections that originate from these sites. They are difficult to isolate from infectious sites, and are frequently missed. Anaerobic infections can occur in all body sites, including the central nervous system, oral cavity, head and neck, chest, abdomen, pelvis, skin, and soft tissues. Anaerobes colonize the newborn after birth and have been isolated in several types of neonatal infections. These include cellulitis of the site of fetal monitoring, neonatal aspiration pneumonia, bacteremia, conjunctivitis, omphalitis, and infant botulism. Management of anaerobic infection is challenging because of the slow growth of these bacteria, by their polymicrobial nature and by the growing antimicrobial resistance of anaerobic. Antimicrobial therapy may be the only treatment required, and may also be an adjunct to a surgical approach. Polymicrobial aerobic-anaerobic infection generally requires delivering antimicrobial therapy effective against all pathogens. The antibiotics with the greatest activity against anaerobes include carbapenems, beta-lactam/beta-lactamase inhibitor combinations, metronidazole, and chloramphenicol. Antimicrobial resistance is growing among anaerobic bacteria. The major increased in resistance have been reported with clindamycin, cephamycins, and moxifloxacin against Bacteroides fragilis group and related strains. Resistance patterns vary between different geographic areas and medical facilities.
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Antibacterianos , Bacterias Anaerobias , Infecciones Bacterianas , Humanos , Bacterias Anaerobias/efectos de los fármacos , Bacterias Anaerobias/aislamiento & purificación , Antibacterianos/uso terapéutico , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/microbiología , Niño , Recién Nacido , Lactante , Farmacorresistencia BacterianaRESUMEN
BACKGROUND: Mediterraneibacter gnavus is a Gram positive, non-sporulated, obligate anaerobe diplococci. It was first described in 1974 by Moore et al. (under the name Ruminococcus gnavus) from faeces and contents of the gastrointestinal tract of humans. It is a relatively common member of the human gut microbiota, nevertheless its role as a pathogenic bacterium has not been completely elucidated yet and it seems to depend on numerous factors, including those of the host. Here we present a case of prosthetic joint infection following total knee arthroplasty by M. gnavus. CASE PRESENTATION: A 74 years old patient was admitted to the emergency department presenting with acute onset of left knee pain and swelling 20 days after total left knee arthroplasty. Follow-up revealed erythema and oedema without signs of fluctuation or purulent discharge from the surgical wound and elevated inflammatory reactants. Synovial fluid was taken for bacterial culture and antibiotic treatment with ceftazidime and daptomycin was established. Examination of the synovial fluid revealed abundant polymorphonuclear leucocytes, without visualizing bacteria. After four days of incubation, anaerobic culture exhibit growth of small, grey, umbilicated colonies in pure culture on Schaedler agar. The microorganism was identified as R. gnavus by MALDI-TOF (Bruker Daltonics) and M. gnavus by 16S ribosomal bacterial sequencing. The isolated showed susceptibility to the most commonly used anaerobicidal antibiotics except for clindamycin. Surgical treatment and infection source control included DAIR (debridement, antibiotics, and implant retention) and vacuum assisted therapy. The patient was discharged after six weeks with a 3-month course of oral amoxicillin as consolidation therapy. Subsequent follow-up revealed adequate wound healing with no signs of infection. CONCLUSIONS: Mediterraneibacter gnavus have been reported as the causal microorganism in a range of human infections, nevertheless its identification remains challenging. Infection of prosthetic joints by anaerobic microorganisms is uncommon and is not considered in its empirical antibiotic treatment, thus, correct and swift identification of anaerobic bacteria in these cases is paramount.
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Antibacterianos , Artroplastia de Reemplazo de Rodilla , Infecciones por Bacterias Grampositivas , Infecciones Relacionadas con Prótesis , Humanos , Infecciones Relacionadas con Prótesis/microbiología , Infecciones Relacionadas con Prótesis/tratamiento farmacológico , Artroplastia de Reemplazo de Rodilla/efectos adversos , Anciano , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/tratamiento farmacológico , Infecciones por Bacterias Grampositivas/diagnóstico , Antibacterianos/uso terapéutico , Masculino , ARN Ribosómico 16S/genética , Bacterias Anaerobias/aislamiento & purificación , Bacterias Anaerobias/genética , Bacterias Anaerobias/clasificación , Líquido Sinovial/microbiologíaRESUMEN
Co-aggregation of anaerobic microorganisms into suspended microbial biofilms (aggregates) serves ecological and biotechnological functions. Tightly packed aggregates of metabolically interdependent bacteria and archaea play key roles in cycling of carbon and nitrogen. Additionally, in biotechnological applications, such as wastewater treatment, microbial aggregates provide a complete metabolic network to convert complex organic material. Currently, experimental data explaining the mechanisms behind microbial co-aggregation in anoxic environments is scarce and scattered across the literature. To what extent does this process resemble co-aggregation in aerobic environments? Does the limited availability of terminal electron acceptors drive mutualistic microbial relationships, contrary to the commensal relationships observed in oxygen-rich environments? And do co-aggregating bacteria and archaea, which depend on each other to harvest the bare minimum Gibbs energy from energy-poor substrates, use similar cellular mechanisms as those used by pathogenic bacteria that form biofilms? Here, we provide an overview of the current understanding of why and how mixed anaerobic microbial communities co-aggregate and discuss potential future scientific advancements that could improve the study of anaerobic suspended aggregates. KEY POINTS: ⢠Metabolic dependency promotes aggregation of anaerobic bacteria and archaea ⢠Flagella, pili, and adhesins play a role in the formation of anaerobic aggregates ⢠Cyclic di-GMP/AMP signaling may trigger the polysaccharides production in anaerobes.
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Archaea , Biopelículas , Archaea/metabolismo , Anaerobiosis , Biopelículas/crecimiento & desarrollo , Bacterias Anaerobias/metabolismo , Bacterias Anaerobias/crecimiento & desarrollo , Bacterias/metabolismo , Bacterias/genética , Interacciones MicrobianasRESUMEN
The application of ANAMMOX technology is constrained by sluggish growth and difficulty in enriching ANAMMOX bacteria. Long-term starvation of functioning bacteria due to limited substrate supply makes the steady operation of ANAMMOX reactors more difficult. Re-examining the start-up and recovery performance of the ANAMMOX reactor and identifying its resistance mechanism are important from the standpoint of long-term starvation. By inoculating nitrifying and denitrifying sludge under various operating circumstances, the ANAMMOX reactors were successfully started. Under various start-up procedures, the tolerance mechanism and recovery performance were examined. The outcomes demonstrated that the denitrifying sludge-inoculated reactor operated steadily with a high substrate concentration and low flow rate. After 85 days of operation, the removal efficiencies of NH4+-N, NO2--N, and total nitrogen reached 98.7%, 99.3%, and 89.3%, respectively. After 144 days of starvation and 30 days of recovery, the better nitrogen removal performance was achieved at a low substrate concentration and high flow rate, and the removal efficiencies were 99.8% ï¼NH4+-Nï¼, 99.8% ï¼NO2--Nï¼, and 93.6% ï¼total nitrogenï¼. During the starvation, extracellular polymeric substances wrapped the ANAMMOX bacteria and kept them intact to resist long-term starvation stress. The expression of nirS, hzsA, and hdh genes ensured the synthesis of nitrite/nitric oxide oxidoreductase, hydrazine synthase, and hydrazine dehydrogenase to maintain ANAMMOX activity. There was no significant difference in the relative abundance of ANAMMOX bacteria before and after starvation recovery. Candidatus Kuenenia had better anti-hunger ability, and the relative abundance increased by more than 86% after 30 days of recovery, confirming its tolerance to long-term starvation.
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Reactores Biológicos , Nitrógeno , Eliminación de Residuos Líquidos , Reactores Biológicos/microbiología , Eliminación de Residuos Líquidos/métodos , Nitrógeno/metabolismo , Nitrógeno/aislamiento & purificación , Compuestos de Amonio/metabolismo , Oxidación-Reducción , Aguas del Alcantarillado/microbiología , Anaerobiosis , Bacterias/metabolismo , Desnitrificación , Bacterias Anaerobias/metabolismo , Amoníaco/metabolismoRESUMEN
The problem of the increasing obesity among children and adolescents is urgent. One of the most interesting and promising directions in this area is to study the correlation of individual microorganisms with the presence and absence of obesity. The aim of the study was to assess the correlation between the isolation frequency of individual microorganisms and the presence of obesity in children and adolescents and to identify possible associations between different groups of microorganisms in obese patients. Material and methods. 156 male and female patients aged from 7 to 17 years were included in the study. The patients were divided into a control group (n=23) (healthy patients), a group of children with exogenous constitutional obesity without complications (n=25), a group of children who had one or more complications of obesity (n=108). For all patients body mass index (BMI) was calculated. Additional examination included a cultural study of the intestinal microbiota. Fecal samples of patients were used as the material. Preparation of the material for inoculation, inoculation and subsequent incubation of the Petri plates were carried out under anaerobic conditions. The isolated microorganisms were identified using the MALDI-ToF mass spectrometry method. Results. When analyzing the correlation between obesity and individual taxa, statistically significant differences were obtained only for Bifidobacterium spp. (p=0.045). The analysis of the correlation between obesity and the isolation of individual microorganisms has shown that Bifidobacterium pseudocatenulatum (p=0.012), Candida albicans (p=0.012), Streptococcus salivarius (p=0.016), Bifidobacterium breve (p=0.003), Veillonella parvula (p=0.013), Haemophilus parainfluenzae (p=0.003), Streptococcus oralis (p=0.001), Weissella confusa (p=0.036), Enterococcus mundtii (p=0.036) were isolated less often in patients with obesity than in control group. Conclusion. The results of the study has demonstrated that only one taxon, Bifidobacterium spp., had a significant correlation with the absence of obesity. At the same time, a reliable correlation with the absence of obesity was also established for individual microorganisms, including several microorganisms from Bifidobacterium spp. and Streptococcus spp., which may enable to establish certain microbiological predictors of obesity and its complications.
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Microbioma Gastrointestinal , Humanos , Masculino , Femenino , Niño , Adolescente , Obesidad/microbiología , Bacterias Anaerobias/aislamiento & purificación , Obesidad Infantil/microbiologíaRESUMEN
OBJECTIVES: We aimed to identify specific anaerobic bacteria causing bacteraemia and a subsequent diagnosis of colorectal cancer. METHODS: A nationwide population-based cohort study, which included all episodes of defined specific anaerobic bacteraemia from 2010 (5,534,738 inhabitants) through 2020 (5,822,763 inhabitants) and all cases of colorectal cancer diagnosed from 2010 through 2021 in Denmark. We calculated the incidence and risk of colorectal cancer after bacteraemia with specific anaerobic bacteria using Escherichia coli bacteraemia as reference. RESULTS: Nationwide data on colorectal cancer and specific anaerobic bacteraemia (100% complete, representing 11,124 episodes). The frequencies of colorectal cancer within one year following anaerobic bacteraemia were higher for species, which almost exclusively reside in the colon, such as Phocaeicola vulgatus/dorei (5.5%), Clostridium septicum (24.2%), and Ruminococcus gnavus (4.6%) compared to 0.6% in 50,650 E. coli bacteraemia episodes. Bacteroides spp. had a subhazard ratio for colorectal cancer of 3.9 (95% confidence interval [CI], 3.0 to 5.1) and for Clostridium spp. it was 8.9 (95% CI, 6.7 to 11.8, with C. septicum 50.0 [95% CI, 36.0 to 69.5]) compared to E. coli (reference). CONCLUSION: This nationwide study identified specific colorectal cancer-associated anaerobic bacteria, which almost exclusively reside in the colon. Bacteraemia with these bacteria could be an indicator of colorectal cancer.
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Bacteriemia , Bacterias Anaerobias , Neoplasias Colorrectales , Humanos , Dinamarca/epidemiología , Bacteriemia/epidemiología , Bacteriemia/microbiología , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/microbiología , Bacterias Anaerobias/aislamiento & purificación , Estudios de Cohortes , Masculino , Femenino , Incidencia , Anciano , Persona de Mediana Edad , Anciano de 80 o más Años , AdultoRESUMEN
Tattooing and use of permanent makeup (PMU) have dramatically increased over the last decade, with a concomitant increase in ink-related infections. Studies have shown evidence that commercial tattoo and PMU inks are frequently contaminated with pathogenic microorganisms. Considering that tattoo inks are placed into the dermal layer of the skin where anaerobic bacteria can thrive and cause infections in low-oxygen environments, the prevalence of anaerobic and aerobic bacteria should be assessed in tattoo and PMU inks. In this study, we tested 75 tattoo and PMU inks using the analytical methods described in the FDA Bacteriological Analytical Manual Chapter 23 for the detection of both aerobic and anaerobic bacterial contamination, followed by 16S rRNA gene sequencing for microbial identification. Of 75 ink samples, we found 26 contaminated samples with 34 bacterial isolates taxonomically classified into 14 genera and 22 species. Among the 34 bacterial isolates, 19 were identified as possibly pathogenic bacterial strains. Two species, namely Cutibacterium acnes (four strains) and Staphylococcus epidermidis (two strains) were isolated under anaerobic conditions. Two possibly pathogenic bacterial strains, Staphylococcus saprophyticus and C. acnes, were isolated together from the same ink samples (n = 2), indicating that tattoo and PMU inks can contain both aerobic (S. saprophyticus) and anaerobic bacteria (C. acnes). No significant association was found between sterility claims on the ink label and the absence of bacterial contamination. The results indicate that tattoo and PMU inks can also contain anaerobic bacteria. IMPORTANCE: The rising popularity of tattooing and permanent makeup (PMU) has led to increased reports of ink-related infections. This study is the first to investigate the presence of both aerobic and anaerobic bacteria in commercial tattoo and PMU inks under aerobic and anaerobic conditions. Our findings reveal that unopened and sealed tattoo inks can harbor anaerobic bacteria, known to thrive in low-oxygen environments, such as the dermal layer of the skin, alongside aerobic bacteria. This suggests that contaminated tattoo inks could be a source of infection from both types of bacteria. The results emphasize the importance of monitoring these products for both aerobic and anaerobic bacteria, including possibly pathogenic microorganisms.
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Bacterias Aerobias , Bacterias Anaerobias , Tinta , ARN Ribosómico 16S , Tatuaje , Bacterias Anaerobias/aislamiento & purificación , Bacterias Anaerobias/genética , Bacterias Anaerobias/clasificación , Bacterias Aerobias/aislamiento & purificación , Bacterias Aerobias/clasificación , Bacterias Aerobias/genética , ARN Ribosómico 16S/genéticaRESUMEN
Little is known of primary production in dark hypersaline ecosystems despite the prevalence of such environments on Earth today and throughout its geologic history. Here, we generated and analyzed metagenome-assembled genomes (MAGs) organized as operational taxonomic units (OTUs) from three depth intervals along a 30-cm sediment core from the north arm of Great Salt Lake, Utah. The sediments and associated porewaters were saturated with NaCl, exhibited redox gradients with depth, and harbored nitrogen-depleted organic carbon. Metabolic predictions of MAGs representing 36 total OTUs recovered from the core indicated that communities transitioned from aerobic and heterotrophic at the surface to anaerobic and autotrophic at depth. Dark CO2 fixation was detected in sediments and the primary mode of autotrophy was predicted to be via the Wood-Ljungdahl pathway. This included novel hydrogenotrophic acetogens affiliated with the bacterial class Candidatus Bipolaricaulia. Minor populations were dependent on the Calvin cycle and the reverse tricarboxylic acid cycle, including in a novel Thermoplasmatota MAG. These results are interpreted to reflect the favorability of and selectability for populations that operate the lowest energy requiring CO2-fixation pathway known, the Wood-Ljungdahl pathway, in anoxic and hypersaline conditions that together impart a higher energy demand on cells.
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Sedimentos Geológicos , Lagos , Metagenoma , Sedimentos Geológicos/microbiología , Utah , Lagos/microbiología , Salinidad , Procesos Autotróficos , Filogenia , Bacterias Anaerobias/genética , Bacterias Anaerobias/metabolismo , Bacterias Anaerobias/clasificación , Dióxido de Carbono/metabolismo , AnaerobiosisRESUMEN
The coupling of microscale zero-valent iron (mZVI) and anaerobic bacteria (AB) has gained increasing attention due to its ability to enhance dechlorination efficiency by combining the advantages of chemical and microbial reduction. However, the implementation of these coupling technologies at the field scale is challenging in terms of sustainability goals due to the coexistence of various natural electron acceptors in groundwater, which leads to limited electron selectivity and increased secondary risk. Therefore, this study used trichloroethylene (TCE) as a probe contaminant and nitrate (NO3-) as a typical co-occurring natural electron acceptor to optimize the overall sustainable remediation performance of an mZVI/AB coupled system by adjusting the mZVI particle size and dosage. Results revealed that mZVI particles of different sizes exhibit different microorganism activation capabilities. In contrast to its 2 µm and 7 µm counterparts, the 30 µm mZVI/AB system demonstrated a strong dosage-dependency in TCE removal and its product selectivity. Finally, multi-criteria analysis (MCA) methods were established to comprehensively rank the alternatives, and 30 µm mZVI (15 g/L dosage) was determined to be the best remediation strategy with the highest total sustainability score under all studied hydro-chemical conditions when equal weights were applied to technical, environmental, and economic indicators. Our work provides a paradigm for comprehensively assessing the sustainable remediation performance of chlorinated aliphatic hydrocarbons polluted groundwater in practical applications.
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Agua Subterránea , Hierro , Nitratos , Tricloroetileno , Agua Subterránea/química , Nitratos/química , Hierro/química , Contaminantes Químicos del Agua/química , Bacterias Anaerobias/metabolismo , Tamaño de la PartículaRESUMEN
Mechanistic investigation of host-microbe interactions in the human gut are hindered by difficulty of co-culturing microbes with intestinal epithelial cells. On one hand the gut bacteria are a mix of facultative, aerotolerant or obligate anaerobes, while the intestinal epithelium requires oxygen for growth and function. Thus, a coculture system that can recreate these contrasting oxygen requirements is critical step towards our understanding microbial-host interactions in the human gut. Here, we demonstrate Intestinal Organoid Physoxic Coculture (IOPC) system, a simple and cost-effective method for coculturing anaerobic intestinal bacteria with human intestinal organoids (HIOs). Using commensal anaerobes with varying degrees of oxygen tolerance, such as nano-aerobe Bacteroides thetaiotaomicron and strict anaerobe Blautia sp., we demonstrate that IOPC can successfully support 24-48 hours HIO-microbe coculture. The IOPC recapitulates the contrasting oxygen conditions across the intestinal epithelium seen in vivo. The IOPC cultured HIOs showed increased barrier integrity, and induced expression of immunomodulatory genes. A transcriptomic analysis suggests that HIOs from different donors show differences in the magnitude of their response to coculture with anaerobic bacteria. Thus, the IOPC system provides a robust coculture setup for investigating host-microbe interactions in complex, patient-derived intestinal tissues, that can facilitate the study of mechanisms underlying the role of the microbiome in health and disease.
Asunto(s)
Técnicas de Cocultivo , Mucosa Intestinal , Organoides , Oxígeno , Humanos , Organoides/microbiología , Organoides/metabolismo , Oxígeno/metabolismo , Técnicas de Cocultivo/métodos , Mucosa Intestinal/microbiología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/citología , Microbioma Gastrointestinal , Interacciones Microbiota-Huesped , Bacterias Anaerobias/crecimiento & desarrollo , Bacterias Anaerobias/metabolismo , Intestinos/microbiología , Intestinos/citología , Bacteroides thetaiotaomicron/metabolismoRESUMEN
BACKGROUND: The combination of immune checkpoint inhibitors with radiotherapy can enhance the immunomodulation by RT and reduce the growth of distant unirradiated tumors (abscopal effect); however, the results are still not very satisfactory. Therefore, new treatment options are needed to enhance this effect. Our previous study showed that the combination of Bifidobacterium (Bi) and its specific monoclonal antibody (mAb) could target and alleviate hypoxia at the tumor site and act as a radiosensitizer. In this study, we explored the anti-tumor efficacy of quadruple therapy (Bi + mAb and RT + αPD-1). The current study also aimed to probe into the complex immune mechanisms underlying this phenomenon. METHODS: Constructed 4T1 breast and CT26 colon cancer tumor models. A comprehensive picture of the impact of constructed quadruple therapy was provided by tumor volume measurements, survival analysis, PET/CT imaging, immune cell infiltration analysis and cytokine expression levels. RESULTS: The abscopal effect was further amplified in the "cold" tumor model and prolonged survival in tumor-bearing mice. Bi can colonized in primary and secondary tumors and direct the mAb to reach the tumor site, activate complement, enhance the ADCC effect and initiate the innate immune response. Then combined with αPD-1 and radiotherapy to stimulate adaptive immune response and synergize with cytokines to expand the immune efficacy and generate effective anti-tumor immune response. CONCLUSIONS: Bi was used as an artificially implanted anaerobic target to cause a transient "infection" at the tumor, causing the tumor to become locally inflamed and "hot", and at the same time, mAb was used to target Bi to enhance the local immune effect of the tumor, and then combined with radiotherapy and αPD-1 to amplify the abscopal effect in multiple dimensions. Therefore, the present study provided a new idea for the multipotent immune-activating function of antibody-targeted anaerobic bacteria for the RT treatment of extensively metastasized cancer patients.
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Anticuerpos Monoclonales , Ratones Endogámicos BALB C , Animales , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales/farmacología , Línea Celular Tumoral , Femenino , Bacterias Anaerobias/inmunología , Ratones , Bifidobacterium , Citocinas/metabolismo , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias/radioterapia , Neoplasias/inmunología , Neoplasias/patología , Neoplasias/terapia , Terapia CombinadaRESUMEN
Understanding how microbial lipidomes adapt to environmental and nutrient stress is crucial for comprehending microbial survival and functionality. Certain anaerobic bacteria can synthesize glycerolipids with ether/ester bonds, yet the complexities of their lipidome remodeling under varying physicochemical and nutritional conditions remain largely unexplored. In this study, we thoroughly examined the lipidome adaptations of Desulfatibacillum alkenivorans strain PF2803T, a mesophilic anaerobic sulfate-reducing bacterium known for its high proportions of alkylglycerol ether lipids in its membrane, under various cultivation conditions including temperature, pH, salinity, and ammonium and phosphorous concentrations. Employing an extensive analytical and computational lipidomic methodology, we identified an assemblage of nearly 400 distinct lipids, including a range of glycerol ether/ester lipids with various polar head groups. Information theory-based analysis revealed that temperature fluctuations and phosphate scarcity profoundly influenced the lipidome's composition, leading to an enhanced diversity and specificity of novel lipids. Notably, phosphorous limitation led to the biosynthesis of novel glucuronosylglycerols and sulfur-containing aminolipids, termed butyramide cysteine glycerols, featuring various ether/ester bonds. This suggests a novel adaptive strategy for anaerobic heterotrophs to thrive under phosphorus-depleted conditions, characterized by a diverse array of nitrogen- and sulfur-containing polar head groups, moving beyond a reliance on conventional nonphospholipid types.
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Lipidómica , Nitrógeno , Fósforo , Azufre , Fósforo/metabolismo , Azufre/metabolismo , Nitrógeno/metabolismo , Adaptación Fisiológica , Sulfatos/metabolismo , Bacterias Anaerobias/metabolismo , AnaerobiosisRESUMEN
BACKGROUND: Clinicians variably obtain anaerobic blood cultures as part of sepsis evaluations in the neonatal intensive care unit (NICU). Our objective was to determine if anaerobic blood culture bottles yielded clinically relevant information by either recovering pathogens exclusively or more rapidly than the concurrently obtained aerobic culture bottle in the NICU. METHODS: A retrospective cohort study of blood cultures obtained from infants admitted to the NICU from August 01, 2015 to August 31, 2023. Standard practice was to inoculate 2 mL of blood divided equally between an aerobic and an anaerobic culture bottle. We analyzed positive blood cultures where both aerobic and anaerobic bottles were obtained and compared pathogen recovery and time to positivity between the bottles. RESULTS: During the study period, 4599 blood cultures were obtained from 3665 infants, and 265 (5.8%) were positive. Of these, 182 cultures were sent as aerobic-anaerobic pairs and recovered pathogenic organisms. Organisms were recovered exclusively from the anaerobic bottle in 32 (17.6%) cultures. Three organisms were obligate anaerobes; the rest were facultative anaerobes including Coagulase-negative staphylococci (40.6%), Escherichia coli (15.6%), and Staphylococcus aureus (15.6%). Cultures with exclusive recovery in the anaerobic bottle were more frequently obtained ≤3 days after birth, compared to other cultures (31.3% vs 15.3%, Pâ =â .03). When both bottles recovered the pathogen (nâ =â 113), the anaerobic bottle had a shorter time to positivity in 76 (67.3%) cultures. CONCLUSIONS: Including anaerobic culture bottles could lead to the identification of pathogens not recovered in the aerobic bottle, as well as earlier identification of pathogens.