Clinical and microbiological characteristics of anaerobic bacteremia during 1994-2019: A Danish population-based cohort study.

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.

Comparison of the diversity of anaerobic-cultured gut bacterial communities on different culture media using 16S rDNA sequencing.

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.

Clinical and microbiological features of anaerobic implant-related infection in 80 patients after orthopedic surgery.

OBJECTIVES: Implant-related infection is a common complication after orthopedic surgery, but there is limited research focused on anaerobic infections. We retrospectively analyzed data from 80 patients with anaerobic implant-related infections in order to investigate the clinical features, bacterial distribution and antimicrobial resistant characteristics of this disease. METHODS: 80 patients who underwent implant-related infections with anaerobes were included. Pathogens were isolated and identified by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry with verification of 16s rRNA sequencing. Antimicrobial susceptibility testing (AST) was performed using Epsilometric test (E-test). RESULTS: Among the 80 patients, 61.2% (49/80) were infected with anaerobes alone, while 38.8% (31/80) were co-infected with anaerobes and other bacteria. Early infection cases involving anaerobe-alone infections were significantly higher compared to the co-infection group (P < 0.001), also exhibiting lower levels of neutrophils (P = 0.033) and ESR (P = 0.046). Anaerobe-alone infections in the prosthetic joint infection group represented a higher proportion compared with other implant-related infections (P = 0.031). Among all species of anaerobes identified, the top 3 were Cutibacterium acnes, Finegoldia magna and Peptostreptococcus anaerobius. Low MIC values to vancomycin was recorded in C. acnes strains and for amoxicillin/clavulanic acid and piperacillin/tazobactam in most F. magna strains. One of the C. acnes and F. magna strains appeared multi-drug resistant except to vancomycin. CONCLUSIONS: Anaerobe-alone infections have later first onset times and lower infection biomarker levels compared to co-infected patients. The first choice against C. acnes is vancomycin, while amoxicillin/clavulanic acid and piperacillin/tazobactam are recommended for F. magna.

An observational study of anaerobic bacteria in cystic fibrosis lung using culture dependant and independent approaches.

Strict anaerobes are undeniably important residents of the cystic fibrosis (CF) lung but are still unknowns. The main objectives of this study were to describe anaerobic bacteria diversity in CF airway microbiota and to evaluate the association with lung function. An observational study was conducted during eight months. A hundred and one patients were enrolled in the study, and 150 sputum samples were collected using a sterile sample kit designed to preserve anaerobic conditions. An extended-culture approach on 112 sputa and a molecular approach (quantitative PCR targeting three of the main anaerobic genera in CF lung: Prevotella, Veillonella, and Fusobacterium) on 141 sputa were developed. On culture, 91.1% of sputa were positive for at least one anaerobic bacterial species, with an average of six anaerobic species detected per sputum. Thirty-one anaerobic genera and 69 species were found, which is the largest anaerobe diversity ever reported in CF lungs. Better lung function (defined as Forced Expiratory Volume in one second > 70%) was significantly associated with higher quantification of Veillonella. These results raise the question of the potential impact of anaerobes on lung function.

Anaerobic bacterial communities associated with oral carcinoma: Intratumoral, surface-biofilm and salivary microbiota.

It was estimated that more than 700 bacterial species inhabit the oral cavity of healthy humans. Anaerobes comprise a significant fraction of the oral bacteriome and play an important role in the formation of multi-species biofilms attached to various anatomical sites. Bacterial biofilms are also associated with pathologic laesions of the oral cavity, including oral squamous cell carcinoma (OSCC), and distinct oral taxa could also be detected within the tumors, i.e. in deep biopsy samples. These observations suggested that certain oral bacteria or oral bacterial communities may play a causative role in oral carcinogenesis, in addition to the well characterized risk factors of oral cancer. Alternatively, it was also proposed that a subset of oral bacteria may have a growth advantage in the unique microenvironment of OSCC. Recently, a series of studies analysed the OSCC-associated bacterial communities using metataxonomic, metagenomic and metatranscriptomic approaches. This review outlines the major differences between the community structure of microbiota in tumor biopsy, surface-biofilm and salivary or oral wash samples collected from OSCC patients, compared to corresponding samples from control persons. A special emphasis is given to the anaerobic bacteria Fusobacterium nucleatum and Fusobacterium periodonticum that were characterised repeatedly as "OSCC-associated" in independent studies. Predicted microbial functions and relevant in vivo experimental models of oral carcinogenesis will also be summarized.

Anaerobic bacteraemia: A score predicting mortality.

The objectives of this study were to report those variables which are readily identifiable at the bedside and that are able to predict mortality in patients with bacteraemia caused by anaerobes. Patients with clinically significant anaerobic bacteraemias detected between January 2016 and December 2019 in a tertiary hospital in Granada (Spain) were retrospectively included. Species identification was performed by MALDI-TOF MS and/or molecular methods. Finally, 136 cases of anaerobic bacteraemia were included, being the most frequent anaerobes Bacteroides (45.5%; n = 62), Clostridium (24.2%, n = 33), and Gram-positive anaerobic cocci (16.1%, n = 22). Crude mortality was 25.7%, corresponding to 35 patients who died, with 82.8% of deaths directly attributable to bacteraemia. A multivariable logistic regression model with non-parametric bootstrap estimation identified three variables that were independently and significantly associated with an increased risk of death: 1) hospitalization in the intensive care unit; 2) septic shock; and 3) presence of any kind of cancer. These variables were as recorded at the time that the first positive blood culture was obtained. An index score, obtained from these variables, was calculated and divided patients into two groups with increasing likelihood of mortality resulting from anaerobic bacteraemia. The sensitivity and specificity of a prediction of death based on this model were 65.2% and 97%, respectively.

Comparison of Total Anaerobic Microbiota in Periodontitis Before and After the Subgingival Irrigation with Chlorhexidine at 0. 12 % / Comparación de la Microbiota Anaerobia Total en Periodontitis antes y Después de la Irrigación Subgingival con Clorhexidina al 0, 12 %

ABSTRACT: The objective of this study was to determine the effect of the subgingival irrigation of chlorhexidine 0.12 % of the total anaerobic microbiota. Microbial sampling to 30 subjects with periodontitis stage II Grade B, in pockets with a periodontal probing depth > 4 mm. The subgingival irrigation was made with 5 mL of chlorhexidine in the test group and with 5 mL of distilled water in the control group. 24 hours after the procedure was obtained a second sample to compare. It was found that the subgingival irrigation with chlorhexidine at 0.12 % achieved a statistically significant decrease in anaerobic microbiota (p< 0.05).

RESUMEN: El objetivo del presente estudio fue determinar el efecto de la irrigación subgingival de la clorhexidina 0,12 % sobre la microbiota anaeróbica total. Se tomaron muestras microbiológicas a 30 sujetos con periodontitis estadio II grado B, en sacos periodontales con una profundidad de sondaje > 4 mm. Se realizó la irrigación subgingival con 5 mL. de clorhexidina en el grupo test y con 5 mL. de agua destilada en el grupo control. 24 horas después del procedimiento se obtuvo una segunda muestra a comparar. Se detectó que la irrigación subgingival con clorhexidina al 0,12 % logra disminuir en forma estadísticamente significativa la microbiota anaeróbica total (p< 0,05).

Anaerobes and laboratory automation: Like oil and water?

Diagnostic laboratories are urged to take advantage of novel technological advancements to provide standardized and high-throughput information for clinicians; however, total laboratory automation (TLA) has only recently been introduced in clinical microbiology in the last 10-12 years. The introduction of total laboratory automation comes with certain advantages and drawbacks that need to be assessed before the introduction of such systems in the diagnostic workflow that includes the detection of anaerobic bacteria. For several reasons, there is yet to be a manufacturer to fully address the issue of anaerobes in the setting of laboratory automation; the aim of the present paper is to address some of the issues associated with anaerobes in lab automation.

'Candidatus Oscillochloris fontis': a novel mesophilic phototrophic Chloroflexota bacterium belonging to the ubiquitous Oscillochloris genus.

We present the results of a study of mesophilic anoxygenic phototrophic Chloroflexota bacteria from Mechigmen hot spring (the Chukotka Peninsula) and Siberia. According to 16S rRNA phylogenetic analysis, these bacteria belong to Oscillochloris trichoides. However, sequencing the draft genome of the bacterium from the Chukotka and analysis of the average nucleotide identity, as well as in silico DNA-DNA hybridization, reveal that this bacterium belongs to a novel species within the Oscillochloris genus. We, therefore, propose 'Candidatus Oscillochloris fontis' as a novel taxon to represent this mesophilic alkaliphilic anaerobic anoxygenic phototrophic bacterium. Spectrophotometry and high-performance liquid chromatography analysis show that the bacterium possesses bacteriochlorophylls c and a, as well as lycopene, ß-carotene and γ-carotene. In addition, transmission electron microscopy shows the presence of chlorosomes, polyhydroxyalkanoate- and polyphosphate-like granules. The genome of 'Ca. Oscillochloris fontis' and the Siberian strains of Oscillochloris sp. possess the key genes for nitrogenase complex (nifH) and ribulose-1,5-bisphosphate carboxylase/oxygenase (cbbL), as previously described for O. trichoides DG-6. The results presented here, and previously published data, show that Oscillochloris bacteria from different aquatic environments have the potential for CO2 and N2 fixation. Additionally, we describe a new primer system for the detection of RuBisCo form I.

Marinitoga lauensis sp. nov., a novel deep-sea hydrothermal vent thermophilic anaerobic heterotroph with a prophage.

A novel moderately thermophilic, heterotrophic anaerobe, designated strain LG1T, was isolated from the Mariner deep-sea hydrothermal vent field along the Eastern Lau Spreading Center and Valu Fa Ridge. Cells of strain LG1T were motile rods, occurring singly or in pairs, 0.6µm in width and 1.2µm in length. The strain LG1T grew between 40 and 70°C (optimum 50-55°C), at a pH between 5 and 8 (optimum pH 6.5) and with 7.5-50gL-1 NaCl (optimum 30gL-1). Sulfur, cystine and thiosulfate were reduced to sulfide, and cell yield was improved in the presence of cystine. Strain LG1T was an organotroph able to use a variety of organic compounds. Phylogenetic analysis based on 16S rRNA gene sequence comparisons indicated that strain LG1T was affiliated to the genus Marinitoga within the order Petrotogales. It shared 95.34-96.31% 16S rRNA gene sequence similarity with strains of other Marinitoga species, and is most closely related to Marinitoga okinawensis. Genome analysis revealed the presence of a prophage sharing high sequence homology with the viruses MPV1, MCV1 and MCV2 hosted by Marinitoga strains. Based on the data from the phylogenetic analyses and the physiological properties of the novel isolate, we propose that strain LG1T is a representative of a novel species, for which the name Marinitoga lauensis sp. nov. is proposed; the type strain is LG1T (=DSM 106824=JCM 32613).

Isolation, characterization, and genome insights into an anaerobic sulfidogenic Tissierella bacterium from Cu-bearing coins.

Recent reports on antimicrobial effects of metallic Cu prompted this study of anaerobic microbial communities on copper surfaces. Widely circulating copper-containing coinage was used as a potential source for microorganisms that had had human contact and were tolerant to copper. This study reports on the isolation, characterization, and genome of an anaerobic sulfidogenic Tissierella sp. P1from copper-containing brass coinage. Dissimilatory (bi)sulfite reductase dsrAB present in strain P1 genome and the visible absorbance around 630 nm in the cells suggested the presence of a desulfoviridin-type protein. However, the sulfate reduction rate measurements with 35SO42- did not confirm the dissimilatory sulfate reduction by the strain. The P1 genome lacks APS reductase, sulfate adenylyltransferase, DsrC, and DsrMK necessary for dissimilatory sulfate reduction. The isolate produced up to 0.79 mM H2S during growth, possibly due to cysteine synthase (CysK) and/or cysteine desulfhydrase (CdsH) activities, encoded in the genome. The strain can tolerate up to 2.4 mM Cu2+(150 mg/l) in liquid medium, shows affinity to metallic copper, and can survive on copper-containing coins up to three days under ambient air and dry conditions. The genome sequence of strain P1 contained cutC, encoding a copper resistance protein, which distinguishes it from all other Tissierella strains with published genomes.

Susceptibility of endometrial isolates recovered from women with clinical pelvic inflammatory disease or histological endometritis to antimicrobial agents.

The CDC recommended outpatient treatment of pelvic inflammatory disease (PID) is an intramuscular dose of ceftriaxone plus 14 days of doxycycline, with or without metronidazole. European guidelines (2017) include moxifloxacin plus ceftriaxone as a first line regimen, particularly for women with Mycoplasma genitalium-associated PID. However, the susceptibility of bacteria recovered from the endometrium of women with PID to moxifloxacin is unknown. The in vitro antibiotic susceptibility of facultative and anaerobic bacteria recovered from endometrial biopsy samples were evaluated from 105 women having symptomatic PID and/or histologically confirmed endometritis. A total of 342 endometrial isolates from enrollment visits were identified using a combination of biochemical tests and sequencing. Isolates were tested for antimicrobial susceptibility using agar dilution against ceftriaxone, clindamycin, doxycycline, metronidazole and moxifloxacin according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Neisseria gonorrhoeae was susceptible to ceftriaxone with all isolates having an MIC of 0.03 µg/mL. All the other endometrial isolates were susceptible to ceftriaxone, except for Prevotella species, only half of which were susceptible. The in vitro susceptibility profile for BV-associated bacteria (Gardnerella vaginalis, Atopobium vaginae, Prevotella species, Porphyromonas species and anaerobic gram-positive cocci) revealed greater susceptibility to moxifloxacin compared to doxycycline. Moxifloxacin was superior to metronidazole for G. vaginalis and A. vaginae, and either metronidazole or moxifloxacin was needed to cover Prevotella species. Based on in vitro susceptibility testing, the combination of ceftriaxone plus moxifloxacin provides similar coverage of facultative and anaerobic pathogens compared to the combination of ceftriaxone, metronidazole and doxycycline. Head to head clinical studies of these treatment regimens are needed to evaluate clinical efficacy and eradication of endometrial pathogens following treatment.

Anaerobes in cystic fibrosis patients' airways.

Anaerobes are known to constitute an important part of the airway microbiota in both healthy subjects and cystic fibrosis (CF) patients. Studies on the potential role of anaerobic bacteria in CF and thus their involvement in CF pathophysiology have reported contradictory results, and the question is still not elucidated. The aim of this study was to summarize anaerobe diversity in the airway microbiota and its potential role in CF, to provide an overview of the state of knowledge on anaerobe antibiotic resistances (resistome), and to investigate the detectable metabolites produced by anaerobes in CF airways (metabolome). This review emphasizes key metabolites produced by strict anaerobic bacteria (sphingolipids, fermentation-induced metabolites and metabolites involved in quorum-sensing), which may be essential for the better understanding of lung disease pathophysiology in CF.

Petroleum hydrocarbon rich oil refinery sludge of North-East India harbours anaerobic, fermentative, sulfate-reducing, syntrophic and methanogenic microbial populations.

BACKGROUND: Sustainable management of voluminous and hazardous oily sludge produced by petroleum refineries remains a challenging problem worldwide. Characterization of microbial communities of petroleum contaminated sites has been considered as the essential prerequisite for implementation of suitable bioremediation strategies. Three petroleum refinery sludge samples from North Eastern India were analyzed using next-generation sequencing technology to explore the diversity and functional potential of inhabitant microorganisms and scope for their on-site bioremediation. RESULTS: All sludge samples were hydrocarbon rich, anaerobic and reduced with sulfate as major anion and several heavy metals. High throughput sequencing of V3-16S rRNA genes from sludge metagenomes revealed dominance of strictly anaerobic, fermentative, thermophilic, sulfate-reducing bacteria affiliated to Coprothermobacter, Fervidobacterium, Treponema, Syntrophus, Thermodesulfovibrio, Anaerolinea, Syntrophobacter, Anaerostipes, Anaerobaculum, etc., which have been well known for hydrocarbon degradation. Relatively higher proportions of archaea were detected by qPCR. Archaeal 16S rRNA gene sequences showed presence of methanogenic Methanobacterium, Methanosaeta, Thermoplasmatales, etc. Detection of known hydrocarbon utilizing aerobic/facultative anaerobic (Mycobacterium, Pseudomonas, Longilinea, Geobacter, etc.), nitrate reducing (Gordonia, Novosphigobium, etc.) and nitrogen fixing (Azovibrio, Rhodobacter, etc.) bacteria suggested niche specific guilds with aerobic, facultative anaerobic and strict anaerobic populations. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) predicted putative genetic repertoire of sludge microbiomes and their potential for hydrocarbon degradation; lipid-, nitrogen-, sulfur- and methane- metabolism. Methyl coenzyme M reductase A (mcrA) and dissimilatory sulfite reductase beta-subunit (dsrB) genes phylogeny confirmed methanogenic and sulfate-reducing activities within sludge environment endowed by hydrogenotrophic methanogens and sulfate-reducing Deltaproteobacteria and Firmicutes members. CONCLUSION: Refinery sludge microbiomes were comprised of hydrocarbon degrading, fermentative, sulfate-reducing, syntrophic, nitrogen fixing and methanogenic microorganisms, which were in accordance with the prevailing physicochemical nature of the samples. Analysis of functional biomarker genes ascertained the activities of methanogenic and sulfate-reducing organisms within sludge environment. Overall data provided better insights on microbial diversity and activity in oil contaminated environment, which could be exploited suitably for in situ bioremediation of refinery sludge.

Anaerobic bacteria cultured from cystic fibrosis airways correlate to milder disease: a multisite study.

Anaerobic and aerobic bacteria were quantitated in respiratory samples across three cystic fibrosis (CF) centres using extended culture methods. Subjects aged 1-69 years who were clinically stable provided sputum (n=200) or bronchoalveolar lavage (n=55). 18 anaerobic and 39 aerobic genera were cultured from 59% and 95% of samples, respectively; 16 out of 57 genera had a ≥5% prevalence across centres.Analyses of microbial communities using co-occurrence networks in sputum samples showed groupings of oral, including anaerobic, bacteria, whereas typical CF pathogens formed distinct entities. Pseudomonas was associated with worse nutrition and F508del genotype, whereas anaerobe prevalence was positively associated with pancreatic sufficiency, better nutrition and better lung function. A higher total anaerobe/total aerobe CFU ratio was associated with pancreatic sufficiency and better nutrition. Subjects grouped by factor analysis who had relative dominance of anaerobes over aerobes had milder disease compared with a Pseudomonas-dominated group with similar proportions of subjects that were homozygous for F508del.In summary, anaerobic bacteria occurred at an early age. In sputum-producing subjects anaerobic bacteria were associated with milder disease, suggesting that targeted eradication of anaerobes may not be warranted in sputum-producing CF subjects.

[THE CONDITION OF THE CERVIX IN WOMEN LIVING IN OIL AND GAS BEARING AREAS].

The aim of the study was to determine the influence of oil products on the development of cervical pathology in women living in oil and gas bearing areas. A retro and prospective study of 300 women was conducted, of which 150 studied - Temir district (main group) and 150 women of Khobdinsky district (control group). It was revealed that a complex of unfavorable environmental factors affecting the body of women living in the oil and gas bearing area leads to deterioration of gynecological health and development of the precancerous process of the cervix: in women of the main group, under constant exposure to harmful factors, significantly more often than in women in the control group reveals precancerous conditions of the cervix of varying severity -28 (18.6%) and 9 (6%). Vaginal contents in women of the main group are characterized by significant disturbances in the microbial flora, which is manifested by a significant increase in the number of strict anaerobic bacteria, 69-46% and 31-20.6%, as compared with the control group. The increased generation of anaerobes is accompanied by a decrease in the frequency of lactobacilli, in particular lactobacilli, which in turn can lead to a disruption of the normal epithelization of the cervix.

Periprosthetic joint infection caused by anaerobes. Retrospective analysis reveals no need for prolonged cultivation time if sensitive supplemented growth media are used.

BACKGROUND: In microbiological diagnosis of periprosthetic joint infection (PJI) culture media and incubation time are controversially discussed, especially if anaerobic bacteria are the causative agent. This study was conducted to demonstrate the influence of sensitive supplemented growth media on the duration of culturing anaerobes. METHODS: Twenty-five consecutive cases were included in this retrospective study. For definition of PJI, the criteria of the Musculoskeletal Infection Society (MSIS) were considered. Histopathological analysis was interpreted according to the classification by Krenn et al. The quantity and time to positivity of detected anaerobes were monitored. Furthermore, antimicrobial activity within the tissue and sonicate fluid was phenotypically tested. RESULTS: In all cases, even if the patients had received antibiotics before recovery, culture of anaerobes (Propionibacterium species, Finegoldia magna, Parvimonas micra and Robinsoniella peoriensis), both from tissue samples and prosthetic components, first became detectable in supplemented liver thioglycollate broth within six days (median: four days). CONCLUSION: Recommendations for prolonged cultivation for up to 14 days mostly aim at detection of anaerobes. Here we present a laboratory procedure that can shorten cultivation time considerably.

Ereboglobus luteus gen. nov. sp. nov. from cockroach guts, and new insights into the oxygen relationship of the genera Opitutus and Didymococcus (Verrucomicrobia: Opitutaceae).

We isolated a novel member of the phylum Verrucomicrobia from the hindgut of the cockroach Shelfordella lateralis. Strain Ho45 is a yellow-pigmented, motile coccus that represents a new genus-level lineage with less than 93% sequence similarity to the 16S rRNA genes of other species in the family Opitutaceae. Ultrastructural analysis revealed a Gram-negative cell envelope with an outer membrane and a periplasmic space. In its ability to ferment sugars to propionate and acetate as major products, strain Ho45 resembles its closest relative, Opitutus terrae. However, the strains differed in their relationship to oxygen. Although strain Ho45 grew and consumed oxygen at sub-atmospheric concentrations (1-4%), both growth rate and cell yield decreased strongly with increasing oxygen concentration in the headspace. By contrast, O. terrae, previously described as an obligate anaerobe, proved to be facultatively aerobic, with highest growth rates and cell yields at 2% and 16% oxygen, respectively. Also the closely related Didymococcus (Diplosphaera) colitermitum, previously described as an obligately aerobic microaerophile, showed a fermentative metabolism under anoxic conditions, forming the same products from glucose as strain Ho45 and O. terrae. Based on phenotypic and phylogenetic evidence, we propose strain Ho45 as the type strain of a novel genus, Ereboglobus luteus gen. nov. sp. nov., and provide an emended description of the family Opitutaceae and the genera Opitutus and Didymococcus.

Longitudinal Analyses of Gut-Associated Bacterial Microbiota in Ulcerative Colitis Patients.

BACKGROUND: The normal colonic microbiota is associated with the etiology of ulcerative colitis (UC). Several bacterial species are associated with the initiation and amplification of disease process. However, the etiology and mechanism of UC are poorly understood. The present study aimed to investigate, characterize, and compare the main composition of the mucosa-associated intestinal microflora in colonoscopic biopsy specimens of UC and non-UC patients. METHODS: Aerobic and facultative-anaerobic mucosa-associated bacteria were isolated and diagnosed from colonoscopic biopsy specimens of 40 UC patients and 40 patients without UC. Patients were selected as control from the same centers and colonoscopy was carried out for other reasons (mainly colorectal screening). Isolation and characterization for aerobic and facultative-anaerobic intestinal bacteria were carried out by conventional culture techniques. DNA extraction from biopsies and polymerase chain reaction (PCR) amplification of bacterial 16S rRNA with gene-targeted and species-specific primers was performed for detection of anaerobic bacterial species. RESULTS: Several species of mucosa-associated aerobic and facultative anaerobic bacteria were found in biopsy specimens and there were no significant differences between UC patients and non-UC patients. Our investigation for detection of the anaerobic intestinal flora showed Faecalibacterium prausnitzii, Prevotella, and Peptostreptococcus productus were the predominant microflora in controls and have significant differences (P = 0.002, 0.025 and 0.039, respectively). CONCLUSION: This is the first investigation of the intestinal mucosa-associated microflora in patients with UC in Iran. These results, although limited by sample size, allow a better understanding of changes in mucosa-associated bacterial flora in these patients, showing that decrease of Faecalibacterium prausnitzii, Provetella, and Peptostreptococcus productus in the intestinal tract may translate into a reduction in the important role of this beneficial bacterial species, which can lead to reduced protection of the gut mucosa and UC development.

Potencial antimicrobiano de extratos glicólicos vegetais sobre bactérias anaeróbias / Antimicrobial potential of plant glycolic extracts on anaerobic bacteria

A resistência microbiana aos antibióticos disponíveis é preocupação constante, devido à dificuldade no tratamento de infecções causadas por cepas resistentes, em decorrência do uso indiscriminado de antimicrobianos. Assim, a busca por terapias antimicrobianas alternativas tem sido crescente e necessária, sendo a fitoterapia umas das opções de escolha. O objetivo do presente estudo foi analisar a atividade antibacteriana de extratos glicólicos de Achyrocline satureioides (macela), Cynara scolymus (alcachofra), Hamamelis virginiana (hamamelis) e Persea americana (abacateiro), pelos períodos de 5 min e 24 h de exposição sobre bactérias anaeróbias Fusobacterium nucleatum subsp. nucleatum, Parvimonas micra, Porphyromonas endodontalis e Porphyromonas gingivalis, em culturas planctônica e biofilmes. As bactérias armazenadas a -80ºC foram ativadas em caldo Brucella enriquecido (hemina 1%, menadiona 1% e sangue de carneiro desfibrinado 5%) e incubadas em câmara de anaerobiose por 48 h a 37ºC por sete dias. A partir de culturas puras, o teste de microdiluição em caldo foi conduzido em microplacas por meio de suspensões bacterianas padronizadas em solução fisiológica estéril (NaCl 0,9%) e diluições dos extratos em caldo, sendo as placas incubadas por 48 h a 37ºC em anaerobiose. Alíquotas de cada poço foram semeadas em ágar Brucella enriquecido. Após incubação, a Concentração Inibitória Mínima (CIM) e Concentração Bactericida Mínima (CBM) foram determinadas. As concentrações efetivas de cada extrato foram aplicadas sobre os biofilmes de cada espécie, formados em microplacas a partir de suspensões bacterianas puras padronizadas na escala 0,5 de McFarland. As microplacas foram incubadas por sete dias a 37ºC para formação dos biofilmes, sendo o meio trocado a cada 48 h. Os biofilmes foram tratados por 5 min e 24 h. Em seguida, foram lavados e desprendidos por homogeneizador ultrassônico. As suspensões diluídas foram adicionadas em ágar Brucella enriquecido. Após 48 h, as Unidades Formadoras de Colônia por mililitro (UFC/mL) foram determinadas. Os resultados foram analisados por ANOVA e teste de Tukey ou por Kruskal-Wallis e teste Dunns, ambos com nível de significância de 5% (p≤0,05). Sobre as culturas planctônicas, a CIM e CBM dos extratos foi determinada apenas para F. nucleatum. A CBM dos extratos de A. satureioides, C. scolymus e P. americana foi obtida sobre P. micra. Não foi obtida atividade bactericida para P. endodontalis e P. gingivalis. Sobre biofilmes, todas as espécies apresentaram reduções significativas quando expostas aos extratos em ambos os tempos. Pode-se concluir que os extratos testados apresentaram efeito bacteriostático sobre F. nucleatum. Atividade bactericida dos extratos foi observada sobre F. nucleatum, bem como sobre P. micra, exceto para H. virginiana. Os extratos avaliados também apresentaram efeito antibiofilme sobre F. nucleatum, P. micra, P. endodontalis e P. gingivalis por 5 min e 24 h de exposição(AU)

Microbial resistance to antibiotics available is constant concern, due to the difficulty in treating infections caused by resistant strains as a result of the indiscriminate use of antimicrobials. Thus, the search for antimicrobial alternative therapies has been growing and necessary, being one option the herbal medicine. The objective of the present study was to analyze the antibacterial activity to Achyrocline satureioides glycolic extracts (macela), Cynara scolymus (artichoke), Hamamelis virginiana (Witch-Hazel) and Persea americana (avocado), for periods of 5 min and 24 h from exhibition on anaerobic bacteria Fusobacterium nucleatum subsp. nucleatum, Parvimonas micra, Porphyromonas gingivalis and Porphyromonas endodontalis in planktonic communities and biofilms. Bacteria stored at -80°C have been activated in Brucella broth enriched (hemin 1%, menadione 1% and defibrinated sheep blood 5%) and incubated in anaerobiose chamber for 48 h at 37° C for seven days. From pure cultures, the microdiluição test in broth was conducted in microplates through standardized bacterial suspensions in sterile saline solution (NaCl 0.9%) and dilution of the extracts in broth, being incubated plates for 48 h at 37° C in anaerobiosis. Aliquots of each well were sown in Brucella agar enriched. After incubation, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined. Effective concentrations of each extract were applied on the biofilms of each species, formed in microplates from pure bacterial suspensions in 0.5 McFarland scale standard. The microplates were incubated for 7 days at 37°C for the formation of biofilms, being the culture medium replaced every 48 h. Biofilms were treated for 5 min and 24 h have been washed and given off by ultrasonic homogenizer. Dilute suspensions were added in Brucella agar enriched. After 48 h, the Colony Forming Units per milliliter (CFU/ml) were determined. The results were analyzed by ANOVA and Tukey test, or Kruskal-Wallis test and Dunns, both with a significance level of 5% (p ≤ 0.05). On the planktonic cultures, CIM and CBM of extracts was determined only to F. nucleatum. The CBM of the extracts of A. satureioides, C. scolymus and P. americana was obtained on P. micra. Bactericidal activity was not obtained for P. endodontalis and P. gingivalis. About biofilms, all species exhibited significant reductions when exposed to the extracts in both times. It can be concluded that the extracts tested showed bacteriostatic effect on F. nucleatum. Bactericidal activity of extracts was observed on F. nucleatum and P. micra, except for H. virginiana. The extracts evaluated also presented antibiofilme effect on F. nucleatum, P. micra, P. endodontalis and P. gingivalis for 5 min and 24 h(AU)