Obligate Anaerobic Bacteria Research Articles

Antimicrobial Susceptibility Profiles of Prevotella Species Determined by Gradient Test Method in Two Centers in Istanbul

Prevotella species, being members of the human microbiota, are obligate anaerobic gram-negative bacteria. These organisms may cause opportunistic infections, including specific oral infections, local or systemic infections. A significant increase of resistance to some antimicrobials has been detected among Prevotella species. The frequency of resistance vary among isolates from different infection sources and between geographic locations. The knowledge about the antimicrobial susceptibility patterns of different Prevotella species is limited in Turkey. Providing the antimicrobial susceptibility data of these bacteria is very important for effective empirical treatment. In this study, we aimed to determine susceptibility data for 12 antimicrobial agents against Prevotella strains originating from human infections, collected in two centers in Turkey. A total of 118 Prevotella strains, isolated from different clinical samples in Marmara University Faculty of Medicine Medical Microbiology and Istanbul University Faculty of Dentistry Oral Microbiology Laboratories between January 2014-December 2017, were tested. Organisms were identified by using MALDI-TOF MS and by 16S rRNA gene sequencing. Minimal inhibitor concentrations of ampicillin, ampicillin-sulbactam, piperacillin-tazobactam, cefoxitin, meropenem, imipenem, clindamycin, tetracycline, tigecycline, moxifloxacin and metronidazole were determined using gradiyent test methodology (E-test; bioMerieux, France) and the European Committee on Antimicrobial Susceptibility Testing, Clinical and Laboratory Standards Institute and Food and Drug Administration guidelines were used for interpretation. Thirteen different Prevotella species were identified, Prevotella bivia and Prevotella nigrescens were the most prevalent species (n= 21) followed by Prevotella buccae (n= 19). All Prevotella strains were susceptible to piperacillin-tazobactam, cefoxitin, meropenem, imipenem and tigecycline. A total of 2 (1.7%) isolates were resistant to metronidazole and 1 (0.8%) isolate was intermediately resistant to ampicillin/sulbactam. The frequency of resistant isolates against ampicillin, clindamycin, tetracycline and moxifloxacin were 57.6%, 36.4%, 18% and 16.3%, respectively. In conclusion, piperacillin/tazobactam, cefoxitin, and tigecycline displayed high in vitro activity against Prevotella spp. and they all remained good candidates for empiric therapy. Imipenem and meropenem were also found to be very active, but the usage of carbapenems should be reserved for serious mixed infections, potentially accompanied by other resistant organisms. Intermediate resistance to ampicillinsulbactam and the resistance against metronidazole emphasized the need of periodic monitoring of their susceptibility patterns. The high rates of non-susceptibility to ampicillin, clindamycin, tetracycline and moxifloxacin indicated that these antimicrobials should not be used for treatment of infections without prior antimicrobial susceptibility testing.

CHANGES IN SMALL INTESTINE MICROFLORA IN PATIENTS WITH ACUTE INTESTINAL OBSTRUCTION

Among urgent surgical diseases of abdominal cavity, an acute intestinal obstruction is the most difficult to be diagnosed and treated. Leading factor, determining the development of pathophysiological processes is considered to be the progressive manifestations of enteric insufficiency syndrome, resulting in intestinal barrier impairment, negative changes in ecology of intestinal flora, increased endotoxins. To identify the small intestine microflora in acute intestinal obstruction and determine the role of dysbiotic disorders in clinical manifestations of main pathological process, a study was conducted in 60 patients with mechanical intestinal obstruction. The small intestine has a relatively rare microflora, consisting mainly of gram−positive facultative aerobic microorganisms, streptococci, lactobacilli. The distal ileum in nearly 30−55 % of healthy people contains scanty microflora, and yet the flora of this area differs from the microbial population of the higher gastrointestinal tract due to higher concentration of gram−negative bacteria. Optional−anaerobic coliform bacilli, anaerobic bifidobacteria and fusobacteria, bacteroids, the number of which starts exceeding the one of gram−positive species, are presented in significant quantities. Distal to the ileocecal valve there are significant changes in the microflora quantitative and species composition. Obligatory anaerobic bacteria become the predominant part of microflora, exceeding the number of aerobic and facultative anaerobic bacteria. The bacterial flora in different parts of gastrointestinal tract has its own specifics and is quite constant, as a result of the interaction of many factors, regulating the bacterial population in small intestine. The most important among them are: acidity of gastric juice, normal peristaltic activity of the intestine, bacterial interactions and immune mechanisms. Disorders of the intestine motor and evacuation function with its obstruction lead to slow passage of the chyme and contamination of the upper gastrointestinal tract with new types of microbes. There is a syndrome of small intestine excessive colonization, which means an increased concentration of bacterial populations in it, similar in species composition to the colon microflora. Pathological intra−intestinal contents become a source of endogenous infection and re−infection of the patient, leads to internal digestive disorders, which is manifested by syndrome of malabsorption of proteins, carbohydrates and vitamins. Key words: acute intestinal obstruction, small intestinal microflora, conditionally pathogenic microorganisms, intestinal biocenosis.

NONSPECIFIC IMMUNITY IN BACTERIAL DYSBIOSIS AND BACTERIAL VAGINOSIS

Relevance. The state of dysbiosis and bacterial vaginosis (BV) is characterized by the formation of both systemic and local immune deficiency, which corresponds to the increase in the number of pathogenic microbiota. It is necessary to study the state of non-specific factors of cellular and humoral resistance in the development of bacterial dysbiosis and BV.
 Objectives – to determine the state of nonspecific immunity in bacterial dysbiosis and BV on CD16-cells, as well as indicators in the blood and vaginal fluid phagocyte leukocytes activity (PhLA) and the content of the components of complement C3 and C4.
 Material and methods. Data from 298 women were divided into groups according to index of pathogenic microbiota condition (IPMC) and the pathogenic microbiota indicator (PMI): normocenosis (n=53), dysbiosis I (n=128) and II degree (n=117), among the last allocated 83 patients with PMI>1 lg gE/sample, which was installed BV. Molecular genetic studies of posterolateral wall of the vagina epithelium scrapings was performed by polymerase chain reaction. Quantitatively determined by facultative and obligate anaerobic bacteria, myco- and ureaplasma, yeast-like fungi. Quantification of the cells CD16+ was performed using erythrocyte diagnosticum (LTD Granum, Ukraine). Traditional immunological methods determined by the PhLA, and components of complement C3 and C4 in blood and vaginal fluid. For statistical and regression analysis used the software Statistica 10 (StatSoft, Inc., USA).
 Results. With the progression of dysbiosis has been an increase in the level of blood CD16-cells, which reached maximum at dysbiosis II degree (by 1.1-1.2 times; p≤0,005). With an increase in dysbiosis shows the formation of the phagocytosis failure, which was more common to BV and took place both at systemic and local levels (reducing the umbilical cord blood is 2.5 times 5.4 times in vaginal fluid). The complement components content were varied in the same way in the blood and vaginal fluid – increases in dysbiosis I degree and decreased with dysbiosis II degree, maximum degree, – in BV (C3 – 1.6 times in the blood and 5.0 times in vaginal secretions; p<0.001). Changes of the examined parameters was more pronounced at the local level, which contributed to the BV development.
 Conclusions. With the progression of bacterial dysbiosis formed the insufficiency of non-specific immunity both at the system level and locally. Changes of the studied indicators in vaginal secretions was more pronounced, which contributed to the development of BV.

Cellular Mercury Coordination Environment, and Not Cell Surface Ligands, Influence Bacterial Methylmercury Production.

The conversion of inorganic mercury (Hg(II)) to methylmercury (MeHg) is central to the understanding of Hg toxicity in the environment. Hg methylation occurs in the cytosol of certain obligate anaerobic bacteria and archaea possessing the hgcAB gene cluster. However, the processes involved in Hg(II) biouptake and methylation are not well understood. Here, we examined the role of cell surface thiols, cellular ligands with the highest affinity for Hg(II) that are located at the interface between the outer membrane and external medium, on the sorption and methylation of Hg(II) by Geobacter sulfurreducens. The effect of added cysteine (Cys), which is known to greatly enhance Hg(II) biouptake and methylation, was also explored. By quantitatively blocking surface thiols with a thiol binding ligand (qBBr), we show that surface thiols have no significant effect on Hg(II) methylation, regardless of Cys addition. The results also identify a significant amount of cell-associated Hg-S3/S4 species, as studied by high energy-resolution X-ray absorption near edge structure (HR-XANES) spectroscopy, under conditions of high MeHg production (with Cys addition). In contrast, Hg-S2 are the predominant species during low MeHg production. Hg-S3/S4 species may be related to enhanced Hg(II) biouptake or the ability of Hg(II) to become methylated by HgcAB and should be further explored in this context.

Advances in Clostridioes difficile genome editing

Clostridioes difficile is a Gram-positive, spore-forming, obligate anaerobic bacterium, and the main cause of hospital-associated diarrhea. In recent years, with the presence of virulent strains (i.e., ribosome type 027), the prevalence and mortality events have increased. Thus, studies on physiological and biochemical characteristics, and pathogenic mechanisms of C. difficile have been performed. The development of efficient and stable genome-editing methods for C. difficile is urgent for the dissection of its physiological and pathogenic mechanism. For example, ClosTron technology plays a key role in study of the relationship between C. difficile toxins (Toxin A and Toxin B) and its pathogenicity. This article reviews the history, recent progress and future prospects of C. difficile genome-editing technologies.

Comparative genetic and physiological characterisation of Pectinatus species reveals shared tolerance to beer-associated stressors but halotolerance specific to pickle-associated strains

Obligate anaerobic bacteria from the genus Pectinatus have been known to cause beer spoilage for over 40 years. Whole genome sequencing was performed on eleven beer spoilage strains (nine Pectinatus frisingensis, one Pectinatus cerevisiiphilus and one Pectinatus haikarae isolate), as well as two pickle spoilage species (Pectinatus brassicae MB591 and Pectinatus sottacetonis MB620) and the tolerance of all species to a range of environmental conditions was tested. Exploration of metabolic pathways for carbohydrates, amino acids and vitamins showed little difference between beer spoilage- and pickle spoilage-associated strains. However, genes for certain carbohydrate- and sulphur-containing amino acid-associated enzymes were only present in the beer spoilage group and genes for specific transporters and regulatory genes were uniquely found in the pickle spoilage group. Transporters for compatible solutes, only present in pickle-associated strains, likely explain their experimentally observed higher halotolerance compared to the beer spoilers. Genes involved in biofilm formation and ATP Binding Cassette (ABC) transporters potentially capable of exporting hop-derived antimicrobial compounds were found in all strains. All species grew in the presence of alcohol up to 5% alcohol by volume (ABV) and hops extract up to 80 ppm of iso-α-acids. Therefore, the species isolated from pickle processes may pose novel hazards in brewing.

Utility of anaerobic bottles for the diagnosis of bloodstream infections

BackgroundObligate anaerobes usually account for less than 10% of bacteria recovered from blood cultures (BC). The relevance of routine use of the anaerobic bottle is under debate. The aim of this study was to evaluate the utility of anaerobic bottles for the diagnosis of bloodstream infections (BSI).MethodsWe conducted a 6-month, retrospective, monocentric study in a tertiary hospital. All positive BC were grouped into a single episode of bacteremia when drawn within 7 consecutive days. Bacteremia were classified into contaminants and BSI. Charts of patients with BSI due to obligate anaerobes were studied.ResultsA total of 19,739 blood cultures were collected, 2341 of which (11.9%) were positive. Anaerobic bottles were positive in 1528 (65.3%) of all positive BC but were positive alone (aerobic bottles negative) in 369 (15.8%). Overall 1081 episodes of bacteremia were identified, of which 209 (19.3%) had positive anaerobic bottles alone. The majority 126/209 (60.3%) were contaminants and 83 (39.7%) were BSI. BSI due to facultative anaerobes, obligate aerobes and obligate anaerobes were identified in 67 (80.7%), 3 (3.6%) and 13 (15.7%) of these 83 episodes, respectively. BSI due to obligate anaerobic bacteria were reported in 9 patients with gastro-intestinal disease, in 3 with febrile neutropenia and in 1 burned patient.ConclusionsAnaerobic bottles contributed to the diagnosis of a significant number of episodes of bacteremia. Isolated bacteria were mostly contaminants and non-obligate anaerobic pathogens. Rare BSI due to obligate anaerobes were reported mainly in patients with gastro-intestinal disorders and during febrile neutropenia.

Оценка микробиоты соскоба уретры у мужчин с инфекциями, передаваемыми половым путем

to conduct a comparative study of the composition of the microbiota of the urethra in men with sexually transmitted infections (STIs), and healthy men. The study included 103 men aged 18 to 45 years: 42 men with urethritis caused by STIs and 61 clinically healthy men. Identification of pathogenic and conditionally pathogenic microorganisms in scrapings from the urethra was performed by PCR in real time (test system Androflor (DNA-Technology, Moscow). In the analysis of the total bacterial mass, it was found that the bacterial contamination of the urethral biotope in patients with STI was significantly higher than in the group of healthy men (5.8 Lg10 and 4.7 Lg10, respectively), with the highest level of bacterial contamination was detected in patients infected with N. gonorrhoeae (6.4 Lg10). Patients with STIs had significantly lower levels of relative Staphylococcus spp., Streptococcus spp., Corynebacterium spp. and their amounts in General compared to clinically healthy men: according to ROC analysis, the best diagnostic indicator (0.93+/-0.04, p<0.001), distinguishing a group of healthy individuals from patients with STI, was the amount of Staphylococcus spp., Streptococcus spp. and Corynebacterium spp. ("Amount Of Normoflor"). In patients infected with C. trachomatis, compared with clinically healthy men, the relative number was significantly higher of Bacteroides spp. / Porphyromonas spp. / Prevotella spp., Peptostreptococcus spp. / Parvimonas spp.; in patients infected with N. gonorrhoeae - Anaerococcus spp. and in patients infected with M. genitalium - Megasphaera spp. / Veillonella spp. / Dialister spp., Anaerococcus spp., Peptostreptococcus spp. / Parvimonas spp. and Eubacterium spp. An increase in the total bacterial contamination of the urethra in STI was found, most pronounced in infection with Neisseria gonorrhoeae. The best diagnostic indicator that distinguishes normal microbiota from the microbiota of patients with STIs is the sum of Staphylococcus spp., Streptococcus spp. and Corynebacterium spp. In patients with clinical signs of an inflammatory reaction and the presence of STIs, a decrease in the normoflora in all types of STIs and an increase in obligate anaerobic bacteria - Megasphaera spp. / Veillonella spp. / Dialister spp., Bacteroides spp. / Porphyromonas spp. / Prevotella spp., Anaerococcus spp., Peptostreptococcus spp. / Parvimonas spp. and Eubacterium spp.

Control of solvent production by sigma-54 factor and the transcriptional activator AdhR in Clostridium beijerinckii.

SummaryClostridia are obligate anaerobic bacteria that can produce solvents such as acetone, butanol and ethanol. Alcohol dehydrogenases (ADHs) play a key role in solvent production; however, their regulatory mechanisms remain largely unknown. In this study, we characterized the regulatory mechanisms of two ADH‐encoding genes in C. beijerinckii. SigL (sigma factor σ54) was found to be required for transcription of adhA1 and adhA2 genes. Moreover, a novel transcriptional activator AdhR was identified, which binds to the σ54 promoter and activates σ54‐dependent transcription of adhA1 and adhA2. Clostridia beijerinckii mutants deficient in SigL or AdhR showed severely impaired butanol and ethanol production as well as altered acetone and butyrate synthesis. Overexpression of SigL resulted in significantly improved solvent production by C. beijerinckii when butyrate was added to cultures. Our results reveal SigL as a novel engineering target for improving solvent production by C. beijerinckii and other solvent‐producing clostridia. Moreover, this study gains an insight into regulation of alcohol metabolism in diverse clostridia.

The Microbiome, Malignant Fungating Wounds, and Palliative Care.

Malignant fungating wounds present in 5–14% of advanced cancer patients in the United States and are a result of cancerous cells infiltrating and proliferating in the skin. Presentation of malignant fungating wounds often occurs in the last 6 months of life and therefore become symbols of impending death for patients and their families. Due to the incurable and severe nature of these wounds, patients require palliative care until death to minimize pain and suffering. Symptoms associated with these chronic wounds include malodor, pain, bleeding, necrosis, large amounts of exudate, increased microbial growth, and more. Limited research using culture-based techniques has been conducted on malignant fungating wounds and therefore no optimal approach to treating these wounds has been established. Despite limited data, associations between the cutaneous microbiome of these wounds and severity of symptoms have been made. The presence of at least one strain of obligate anaerobic bacteria is linked with severe odor and exudate. A concentration of over 105/g bacteria is linked with increased pain and exudate. Bacterial metabolites such as DMTS and putrescine are linked with components of malignant fungating wound odor and degradation of periwound skin. The few but significant associations made between the malignant fungating wound microbiome and severity of symptoms indicate that further study on this topic using 16S rRNA gene sequencing may reveal potential therapeutic targets within the microbiome to significantly improve current methods of treatment used in the palliative care approach.

Identification of uncultured bacteria from abscesses of exotic pet animals using broad-range nested 16S rRNA polymerase chain reaction and Sanger sequencing.

Background:The Sanger sequencing technique has been questioned and challenged by advanced high-throughput sequencing approaches. Sanger sequencing seems to be an obsolete technology. However, there are still research problems that could be answered using the Sanger sequencing technology. Fastidious obligate anaerobic bacteria are mostly associated with abscesses in animals. These bacteria are difficult to isolate from abscesses and are frequently excluded due to the bias of conventional bacterial culturing.Aim:This study demonstrated the usefulness of a broad-range polymerase chain reaction (PCR) with Sanger sequencing to identify the majority population of bacteria in abscesses from exotic pet animals.Materials and Methods:This study performed a pilot investigation of abscesses from 20 clinical cases (17 rabbits, 2 hedgehogs, and 1 sugar glider) using standard culture methods for both aerobes and anaerobes and broad-range nested PCR targeting the 16S rRNA gene followed by the Sanger sequencing technique.Results:The standard culture and PCR techniques detected bacteria in 9 and 17 of 20 samples, respectively. From the 17 sequencings of the 16S rRNA, 10 PCR products were found to be closely related with obligate anaerobes including Bacteroides spp., Fusobacterium spp., Prevotella spp. Phylogenetic analysis using the rpoB gene revealed that the species for the Bacteroides was thetaiotaomicron and for the Fusobacterium was varium and nucleatum. However, the amplification of the rpoB gene for the Prevotella spp. was unsuccessful. Correlations between the standard culture and PCR techniques were found in 9 (6 positive and 3 negative samples) of 20 samples. Eleven samples were discordant between the standard culture and PCR techniques which were composed of eight samples negative by culture but positive by PCR and three samples had different bacteria by the culture and PCR techniques.Conclusion:According to this study, broad-range PCR combined with Sanger sequencing might be useful for the detection of dominant anaerobic bacteria in abscesses that were overlooked based on conventional bacterial culture.

Investigation of role of anaerobic bacteria in cystic fibrosis patients

Repetitive pulmonary infections are the main cause of morbidity and mortality in cystic fibrosis (CF) patients. In recent years, non-culture dependent metagenomic studies showed complex dynamics of the pulmonary environment of CF patients and pointed out the importance of anaerobic bacteria. Molecular-based studies indicate that anaerobic bacteria can be found more than aerobic or facultative anaerobic bacteria in CF lung environment. However, limited number of studies are far away to clarify the importance of anaerobic bacteria in CF pulmonary disease. The aim of this study was to evaluate the role of anaerobic bacteria in CF patients admitted to Hacettepe University, Pediatric Respiratory Diseases Department, by using quantitative culture method for both aerobic and anaerobic bacteria. Anaerobic bacteria were identified by conventional and semi-automated methods. Antibiotic susceptibilities were performed by agar dilution method. Seventy-seven anaerobic bacteria were isolated from 35 (81.4%) of 43 patients. The total count of anaerobes and facultative bacteria (mean 16 x 106), was higher than aerobes and facultative bacteria (mean 14.1 x 106). If anaerobe culture were not performed merely 63.65% of all species could be obtained. In patients whose samples yielded intermediate or high numbers of PMNLs, significantly more obligate anaerobic bacteria were isolated (p= 0.046). Patients older than 18 years were colonized with higher number of anaerobic bacteria. Susceptibilities of 72 isolates out of 77, against ampicillin, sulbactam-ampicillin, piperacillin, piperacillin-tazobactam, moxifloxacin, metronidazole, imipenem, and clindamycin were also evaluated. Clindamycin was found to be the least effective antibiotic among all. None of the isolates was resistant to imipenem. This is the first study to show the role and importance of anaerobic bacteria in CF patients in our country. The resistance rates in anaerobic bacteria isolated from CF patients is concerning. Therefore, intermittent anaerobic culture and follow-up of resistance rates will be helpful in the follow-up of these patients.

Antimicrobial susceptibility surveillance of obligate anaerobic bacteria in the Kinki area

Obligate anaerobes exist as resident flora in various sites in humans, but they are also emphasized as endogenous causative microorganism of infections. We performed surveillance to understand the trend of drug susceptibility in obligate anaerobic bacteria in the Kinki area of Japan. In the experiment, we used 156 obligate anaerobe isolates collected from 13 institutions that participated in the Study of Bacterial Resistance Kinki Region of Japan. MALDI Biotyper was used to identify the collected strains, and among the 156 test strains, those that could be identified with an accuracy of Score Value 2.0 or more included 6 genera, 30 species, and 144 strains (Bacteroides spp. 77 strains, Parabacteroides sp. 2 strains, Prevotella spp. 29 strains, Fusobacterium spp. 14 strains, Porphyromonas spp. 2 strains, and Clostridioides difficile 20 strains), and they were assigned as subject strains for drug susceptibility testing. The drug susceptibility test was carried out by broth microdilution method using Kyokuto Opt Panel MP ANA (Kyokuto Pharmaceutical Industrial Co., Ltd., Tokyo, Japan) and judged according to CLSI criteria. As a result, Bacteroides and Parabacteroides species showed good sensitivities to tazobactam-piperacillin, imipenem, metronidazole and chloramphenicol, and low sensitivities to ampicillin, cefoperazone and vancomycin. Prevotella species showed good sensitivities to sulbactam-ampicillin, tazobactam-piperacillin, cefmetazole, imipenem, doripenem and metronidazole. Susceptibility rates to other drugs were slightly different depending on the bacterial species. Both Fusobacterium spp. and Porphyromonas spp. showed high sensitivities to many drugs. C. difficile was highly sensitive to vancomycin and metronidazole, having MIC90s of 0.5 μg/mL and ≤2 μg/mL, respectively.

Complete Genome Sequence of Caloramator sp. Strain E03, a Novel Ethanologenic, Thermophilic, Obligately Anaerobic Bacterium.

Here, we report the complete genome sequence of Caloramator sp. strain E03, an anaerobic thermophile that was isolated from a hot spring within the Rabbit Creek area of Yellowstone National Park. The assembly contains a single 2,984,770-bp contig with a G+C content of 31.3% and is predicted to encode 2,678 proteins.

OxyR senses sulfane sulfur and activates the genes for its removal in Escherichia coli

Sulfane sulfur species including hydrogen polysulfide and organic persulfide are newly recognized normal cellular components, and they participate in signaling and protect cells from oxidative stress. Their production has been extensively studied, but their removal is less characterized. Herein, we showed that sulfane sulfur at high levels was toxic to Escherichia coli under both anaerobic and aerobic conditions. OxyR, a well-known regulator against H2O2, also sensed sulfane sulfur, as revealed via mutational analysis, constructed gene circuits, and in vitro gene expression. Hydrogen polysulfide modified OxyR at Cys199 to form a persulfide OxyR C199-SSH, and the modified OxyR activated the expression of thioredoxin 2 and glutaredoxin 1. The two enzymes are known to reduce sulfane sulfur to hydrogen sulfide. Bioinformatics analysis indicated that OxyR homologs are widely present in bacteria, including obligate anaerobic bacteria. Thus, the OxyR sensing of sulfane sulfur may represent a preserved mechanism for bacteria to deal with sulfane sulfur stress.

A Tertiary Hospital Based Study on Prevalence of Bacterial Vaginosis in Post- Partum Cases

Background: The endogenous micro flora contains a variety of bacteria. These are aerobic, facultative and obligate anaerobic bacteria like many important pathogens such as Klebsiella, Pseudomonas, Escherichia coli, Staphylococcus, Streptococcus species and besides the normal lactobacilli. These organisms exist in a commensal, synergistic or antagonistic relationship. Methods: This study was conducted in Department of Gynecology in Adesh Institute of Medical Sciences and Research, Bathinda, Punjab. Study Population: -50 post-partum cases were subjected in this study. Results: In this study 50 total numbers of cases were included, out of which 60% were belongs to 25-29 age group followed by 20-24 (32%), 30-34 (6%) & 35-40 (2%) age group. 16% infection occur in the post -partum study out of fifty cases caused by different types of organism. Conclusion: This study reveals that in post-partum period, addition of lactobacilli iatrogenically may prove to be useful in prevention of infection.

Filling the gap between collection, transport and storage of the human gut microbiota

Stool collection devices minimizing the exposure of gut bacteria to oxygen are critical for the standardization of further microbiota-based studies, analysis and developments. The aim of this work was to evidence that keeping anaerobiosis has a deep impact on the viability and diversity of the fecal microbiota that is recovered in the laboratory. Recovering certain microbial populations, such as obligate anaerobic bacteria, is particularly critical if the purpose of the study is to envisage personalized therapeutic purposes, such as autologous Fecal Microbiota Transplant. In this study the same fecal specimens were sampled in conventional stool containers and GutAlive, a disposable device that minimizes exposure of the gut microbiota to oxygen. Samples from five healthy donors were analysed and 150 differential colonies were recovered and identified by 16S rRNA gene sequencing. Globally, GutAlive maintained extremely oxygen sensitive (EOS) populations that were lost in conventional stool containers, and thus viability of species such as as Akkermansia muciniphila, Faecalibacterium prausnitzii and a novel member of the Clostridiales order was kept. These obligate anaerobes were not recovered using the conventional stool collection device. In conclusion, the use of GutAlive for stool collection and transport optimized the viability and recovery of EOS bacteria in the lab by diminishing oxygen toxicity.

Engineering Clostridium for improved solvent production: recent progress and perspective.

Clostridia are Gram-positive, spore-forming, obligate anaerobic bacteria that can produce solvents such as acetone, ethanol, and butanol, which can be used as biofuels or building block chemicals. Many successful attempts have been made to improve solvent yield and titer from sugars through metabolic engineering of solventogenic and acidogenic clostridia. More recently, cellulolytic and acetogenic clostridia have also attracted high interests for their ability to utilize low-cost renewable substrates such as cellulose and syngas. Process engineering such as in situ butanol recovery and consolidated bioprocessing (CBP) has been developed for improved solvent titer and productivity. This review focuses on metabolic and process engineering strategies for solvent production from sugars, lignocellulosic biomass, and syngas by various clostridia, including conventional solventogenic Clostridium acetobutylicum, engineered acidogens such as C. tyrobutyricum and C. cellulovorans, and carboxydotrophic acetogens such as C. carboxidivorans and C. ljungdahlii.

A complex human gut microbiome cultured in an anaerobic intestine-on-a-chip.

The diverse bacterial populations that comprise the commensal microbiome of the human intestine play a central role in health and disease. A method that sustains complex microbial communities in direct contact with living human intestinal cells and their overlying mucus layer in vitro would thus enable investigations of host–microbiome interactions. Here, we show the extended co-culture of living human intestinal epithelium with stable communities of aerobic and anaerobic human gut microbiota, enabled by a microfluidic intestine-on-a-chip that permits the control and real-time assessment of physiologically relevant oxygen gradients. When compared to aerobic co-culture conditions, the establishment of a transluminal hypoxia gradient in the chip increased intestinal barrier function and sustained a physiologically relevant level of microbial diversity, consisting of over 200 unique operational taxonomic units from 11 different genera, and of an abundance of obligate anaerobic bacteria with ratios of Firmicutes and Bacteroidetes similar to those observed in human faeces. The intestine-on-a-chip may serve as a discovery tool for the development of microbiome-related therapeutics, probiotics and nutraceuticals.

Prevotella cerevisiae sp. nov., beer-spoilage obligate anaerobic bacteria isolated from brewery wastewater.

Two obligate anaerobic, Gram-stain-negative, non-spore-forming bacilli (strains SBC 8034T and SBC 8065) were isolated from brewery wastewater. Cells of the two strains were rod-shaped and 0.8×2-5 µm in size. Strains SBC 8034T and SBC 8065 did not grow on Columbia agar or tryptic soy agar II with 5 % sheep blood, brain-heart infusion agar or chocolate agar, but did grow on peptone-yeast-glucose agar and de Man, Rogosa and Sharpe agar using beer instead of water. The organisms produced acetic acid and succinic acid as the major metabolic end-products. Phylogenetic analysis based on 16S rRNA gene sequences revealed that both strains are clearly distinct from all recognized species within the genus Prevotella, but belong to the same species (DDH=85 %). Based on 16S rRNA and hsp60 gene sequencing, along with phenotypic, chemical and biochemical properties, strains SBC 8034T and SBC 8065 were considered to represent a novel species within the genus Prevotella, for which the name Prevotellacerevisiae sp. nov. is proposed. Strain SBC 8034T (=DSM 100619T=JCM 30867T) is the type strain of the proposed novel species.