Negative Anaerobic Bacteria Research Articles

Use of Magnetic Nanoparticles to Isolate Anaerobic Bacteria

Objective: Anaerobic bacteria, which make up an important part of normal body flora, may lead to serious life-threatening infections. Since isolation and identification of anaerobic bacteria require time-consuming, sensitive, and difficult methods, they can only be performed in certain clinical laboratories. For this reason, diagnosis and treatment of anaerobic infections are delayed and drug resistance is observed due to empirical treatment. New methods that will enable the early identification of these bacteria will help reduce the duration of treatment and mortality rates due to anaerobic infections. Method: In this study, it is aimed to design magnetic nanoparticles attached to N-methyl-D-glucamine (Mag-NMDG) to catch anaerobic bacteria for rapid identification. Mag-NMDG nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), and vibrating sample magnetometer (VSM). Results: Mag-NMDG nanoparticles were applied to gram positive and gram negative anaerobic bacteria such as Actinomyces odontolyticus, Prevotella buccae, Veillonella parvula, Bifidobacterium dentium and Bacteroides fragilis isolated from culture media. The binding of bacteria to Mag-NMDG was determined by microscope images, McFarland values, and MALDI-TOF MS identification scores. Conclusion: As a result of this study, it was concluded that the Mag-NMDG nanoparticles could be used to isolate anaerobic bacteria directly from samples. Thus, it is foreseen that many time-consuming and troublesome steps in the isolation and identification stages can be eliminated.

A Phenolic-rich Extract of Cocoa (Theobroma cacao L.) Beans Impairs the Pathogenic Properties of Porphyromonas gingivalis and Attenuates the Activation of Nuclear Factor Kappa B in a Monocyte Model.

Periodontitis, an inflammatory disease that affects tooth-supporting tissues, is the result of a polymicrobial infection involving mainly Gram negative anaerobic bacteria. The aim of the present study was to investigate the effects of a phenolic-rich extract of cocoa (Theobroma cacao L.) beans on the pathogenic properties of Porphyromonas gingivalis, which is well-known as a keystone pathogen in the development of periodontitis. The effect of the cocoa extract on P. gingivalis-induced activation of the nuclear factor kappa B (NF-κB) transcription factor in a monocyte model was also assessed. The cocoa extract, whose major phenolic compound was epicatechin, inhibited the growth, hemolytic activity, proteolytic activities, and adherence properties (basement membrane matrix, erythrocytes) of P. gingivalis in a dose-dependent manner. It also protected the barrier function of a keratinocyte model against the deleterious effects mediated by P. gingivalis, and attenuated reactive oxygen species (ROS) production by oral keratinocytes treated with P. gingivalis. Lastly, the cocoa extract showed an anti-inflammatory property by preventing P. gingivalis-induced NF-κB activation in monocytes. In conclusion, this in vitro study highlighted the potential value of an epicatechin-rich extract of cocoa beans for preventing and/or treating periodontal diseases.

Role of reactive oxygen species and antioxidants in periodontal disease

Recent epidemiological studies reveal that more than two-third of the world’s population suffers from one of the chronic forms of periodontal disease. The primary etiological agent of this inflammatory disease is a polymicrobial complex, predominantly Gram negative anaerobic or facultative bacteria within the sub-gingival biofilm. These bacterial species initiate the production of various cytokines such as interleukin-8 and TNF-α, further causing an increase in number and activity of polymorphonucleocytes (PMN) along with these cytokines, PMNs also produce reactive oxygen species (ROS) superoxide via the respiratory burst mechanism as the part of the defence response to infection. ROS just like the interleukins have deleterious effects on tissue cells when produced in excess. To counter the harmful effects of ROS, human body has its own defence mechanisms to eliminate them as soon as they are formed. The aim of this review is to focus on the role of different free radicals, ROS, and antioxidants in the pathophysiology of periodontal tissue destruction.

Antimicrobial susceptibility pattern of oral gram negative anaerobes from Indian subjects

ObjectivesThere is paucity of information on the antimicrobial susceptibility pattern of oral anaerobic bacteria. In this study, an attempt has been made to evaluate the antimicrobial susceptibility/resistance trend of oral Gram negative bacteria from Indian subjects. MethodsMinimum inhibitory concentrations (MIC) of 304 isolates against twelve different antibiotics were determined using gradient diffusion MIC strips. The organisms were isolated and identified based on phenotypic characteristics and included Porphyromonas gingivalis, Prevotella species, Tannerella forsythia, Fusobacterium nucleatum, Aggregatibacter actinomycetemcoitans, Eickenella corrodens and Capnocytophaga species. For each antimicrobial agent, MIC50 and MIC90 were calculated and expressed. ResultsResistance to azithromycin, clindamycin, and amoxicillin was observed in most of the anaerobic bacterial species studied. High degree of susceptibility was observed to amoxillin-clavulanic acid, doxycycline and moxifloxacin. A single strain of P. melaninogenica was resistant to moxifloxacin. The susceptibility pattern varied with cephalosporins among species. Ceftriaxone showed highest and cefazolin least efficacy among cephalosporins. All anaerobic bacteria tested were susceptible to metronidazole. Strains of T. forsythia were more resistant to several antibiotics than other anaerobic bacteria. All three species of capnophilic bacteria displayed high degree of resistance to metronidazole and significant resistance to amoxicillin, azithromycin, clindamycin, cefazolin and cefuroxime. ConclusionsAmoxicillin-clavulanic acid, doxycycline, moxifloxacin and metronidazole appeared to be the most effective drugs against gram negative anaerobic bacteria. However, the MIC50 and MIC90 values against metronidazole were on the higher side of the normal indicating a potential for developing resistance.

Epigenetics and pathogensis: A newflanged review

Genetics and epigenetics is the process of gene expression or suppression through polymorphism, demethylation, and deacetylation. Although Periodontal diseases are bacterial infections predominantly gram negative anaerobic bacteria that colonize the sub gingivaly in return triggering an inflammatory response which affect the periodontium; whereas periodontitis is a periodontal disease which destroys the tissue and bone that surrounds the tooth. In adults periodontitis is at helm of tooth loss. Pathogenic microrgansims are considered as the primary aetiological factor, but the disease progression is also influenced by Genotype and Phenotype of various individuals. Phenotypic factors such as race, diabetes, gender, education, smoking etc. have sweeping effects on the epigenetic changes and impel susceptibility to disease. Epigenetic modifications expression occur in response to environmental changes.

Development of Lipomer Nanoparticles for the Enhancement of Drug Release, Anti-microbial Activity and Bioavailability of Delafloxacin.

Delafloxacin (DFL) is a novel potent and broad-spectrum fluoroquinolone group of antibiotics effective against both Gram-positive and negative aerobic and anaerobic bacteria. In this study, DFL-loaded stearic acid (lipid) chitosan (polymer) hybrid nanoparticles (L-P-NPs) have been developed by single-emulsion-solvent evaporation technique. The mean particle size and polydispersity index (PDI) of optimized DFL-loaded L-P-NPs (F1-F3) were measured in the range of 299–368 nm and 0.215–0.269, respectively. The drug encapsulation efficiency (EE%) and loading capacity (LC%) of DFL-loaded L-P-NPs (F1-F3) were measured in the range of 64.9–80.4% and 1.7–3.8%, respectively. A sustained release of DFL was observed from optimized DFL-loaded L-P-NPs (F3). Minimum inhibitory concentration (MIC) values of the DFL-loaded L-P-NPs (F3) appeared typically to be four-fold lower than those of delafloxacin in the case of Gram-positive strains and was 2-4-fold more potent than those of delafloxacin against Gram-negative strains. The pharmacokinetic study in rats confirmed that the bioavailability (both rate and extent of absorption) of DFL-loaded L-P-NPs was significantly higher (2.3-fold) than the delafloxacin normal suspension. These results concluded that the newly optimized DFL-loaded L-P-NPs were more potent against both Gram-positive and negative strains of bacteria and highly bioavailable in comparison to delafloxacin normal suspension.

Eravacycline: A Review in Complicated Intra-Abdominal Infections.

Eravacycline (Xerava™), a novel fully synthetic fluorocycline, consists of the tetracyclic core scaffold with unique modifications in the tetracyclic D ring; consequently, it exhibits potent in vitro activity against Gram-positive and -negative bacterial strains expressing certain common tetracycline-specific acquired resistance mechanisms. In vitro, eravacycline exhibits potent activity against a broad spectrum of clinically relevant Gram-positive and -negative aerobic and anaerobic bacteria. Intravenous eravacycline is approved in several countries for the treatment of complicated intra-abdominal infections (cIAIs) in adult patients. In two pivotal double-blind, multinational trials in this patient population, eravacycline (infusion ≈ 1 h) was noninferior to intravenous ertapenem or meropenem at the test-of-cure visit in terms of clinical response rates in all prespecified populations. Eravacycline had an acceptable tolerability profile, with infusion site reactions, nausea, vomiting and diarrhoea the most commonly reported adverse reactions, most of which were of mild to moderate severity. Given its broad spectrum of activity against common clinically relevant pathogens (including those expressing certain tetracycline- and other antibacterial-specific acquired resistance mechanisms) and its more potent in vitro activity and better tolerability profile than tigecycline, eravacycline provides a novel emerging option for the treatment of adult patients with cIAIs, especially as empirical therapy when coverage of resistant pathogens is required.

Polymerase chain reaction assay targeting nox gene for rapid identification of Brachyspira canis in dogs.

Genus Brachyspira, as Gram negative anaerobic bacteria, colonize in dogs intestine. The aim of the current study was to determine the prevalence of Brachyspira spp. for the first time in Iran and rapid identification of Brachyspira spp. in dogs by a new designment of a species-specific primer set for B. canis. One hundred fifty-one fecal samples were obtained from dogs by rectal swab. Twenty dogs suffered from diarrhea and 131 of them were healthy. In 9.27% (14/151) of samples, spirochaetes were detected on primary cultures by weak hemolysis and positive Gram staining and then Brachyspira genus was confirmed by NADH oxidase (nox) gene via polymerase chain reaction. Among 14 isolates, twelve isolates were B. canis, one isolate was B. intermedia and another one was non-typeable. From 12 B. canis, only eight isolates were detected by designed specific primers. Ten Brachyspira spp. were isolated from dogs ≤ 1 year old (10/67, 14.92%) and 4 isolates were from > 1 year old dogs (4/84, 4.76%). The isolation rates from healthy and diarrheic dogs were (12/131, 9.16%) and (2/20, 10.00%), respectively. A statistically significant association was observed between the presence of Brachyspira spp. and the age under one year. Based on our findings, the nox gene in B. canis might have more sequence variability compared to other Brachyspira spp.

Analysis on the distribution and drug resistance features of anaerobes isolated from clinical infectious specimens

Objective: To clarify distribution and drug resistance characteristics of anaerobes isolated from clinical infectious samples, and to provide experimental data for guiding on treatment of infections caused by anaerobes. Methods: The anaerobes, isolated from 1 057 different clinical specimens from inpatients admitted to the Affiliated Hospital of Inner Mongolia Medical University from March 2016 to November 2017, were identified by VITEK-2 anaerobes and corynebacterium (ANC) card and bacteroides fragilis isolates were further verified by 16S-rRNA sequencing. Meanwhile, broth dilution method was employed to detect the drug sensititities of bacteroides fragilis and PCR method was used to detect the carbapenem resistance gene cfiA. Results: Totally 303 strains of anaerobic bacteria were isolated, among which 199 strains were gram-negative bacteria, accounted for 65.68%. Among the gram negative anaerobes, bacteroides species were the most common, accounted for 35.64%, followed by prevotella spp., which accounted for 19.14%. B. fragilis were the most common among Bacteroides spp., accounted for 21.54%, followed by Prevotella bivia, accounted for 5.94%. The coincidence rate of 16S-rRNA sequencing results of Bacteroides fragilis and that of ANC card identification results was 100% (65/65). The drug resistance of B. fragilis to penicillin, clidamycin, ampicillin/sulbactam, amoxicillin/clavulanic, were 100%, 90.77%, 56.92% and 66.67%, respectively. The resitance rate of B. fragilis to chloramphenicol was the lowest, which was 1.54%.Moreover, the resistance rate of B. fragilis to imipenem and metronidazole were both higher, which were 38.46%(25/65) and 23.08%(15/65), respectively, and the positive rate of beta lactamase was 100% (65/65). The carrying rate of carbapenems resistance gene cfiA for 65 strains of Bacteroides fragilis was 52.3% (34/65), and 72.00%(18/25)for imipenem resistant strains. Conclusions: The obligate anaerobic bacteria are widely distributed in clinical specimens, and the great majority are gram negative anaerobic bacteria, and the most frequently isolated one is Bacteroides fragilis. Bacteroides fragilis isolates are found to be resistant to several kinds of common antibiotics, especially for imipenem and metronidazole, which should be given more attention to.

Exploratory Study of Archaebacteria and their Habitat in Underground, Opencast Coal Mines and Coal Mine Fire Areas of Dhanbad

ABSTRACT Coal contains abundant microbial genera which include archaebacteria. The study of archaea kingdom in coal mines is a significant tool for knowing the relationship between coal and archaebacteria, the major role in geochemical cycle and application for further coal bio–beneficiation. The present study related to exploration of archaebacteria and their habitat in coal mining area of Dhanbad with reference to their ecology and nutrient availability that have evolve to grow under extreme conditions. Total six different sites such as two underground coal mines (Sudamdih shaft and Chasnalla underground mine), two opencast coal mines (Chandan project and Bhowra abandoned mine), Jharia mine fire and Sudamdih coal washery of Dhanbad was selected. Seven gram negative obligate anaerobic bacteria were isolated from the selected sites. The isolated species were rod and cocci shaped and the colony was round, smooth, off white in colour and with entire margin and little are cluster of cocci in shape. The isolated species were identified as Methanococcus spp, Methanobacterium spp and Methanosarcina spp. Apart from that two thermoacidophilic sulfur oxidizing bacteria Sulfolobus spp was also isolated from Jharia Coal Mine Fire. The physicochemical and biological characterization of the habitat was also studied for the entire selected area.

Oral ofloxacin and clindamycin as an alternative to the classic rifampicin–clindamycin in hidradenitis suppurativa: retrospective analysis of 65 patients

Rifampicin/Clindamycin (RC) combination is recommended as first line therapy in moderate to severe Hidradenitis Suppurativa (HS) by European S1 guidelines (1–3), notably because a large variety of microorganisms have been isolated from HS lesions: most represented bacteria appear to be Staphylococcus aureus, Coagulase negative staphylococci (CoNS) and anaerobic bacteria from normal skin flora. It has been hypothesized that these bacteria could play a central role in the initiation and maybe in the maintenance of HS lesions, possibly by being a source of antigens in a dysregulated immune response. This article is protected by copyright. All rights reserved.

Epigenetics in Periodontal Diseases

Genetics and epigenetics is the process by which genes were expressed or suppressed through polymorphism, demethylation, and deacetylation. Many Environmental factors such as race, gender, diabetes, education, smoking etc. can have profound effects on the epigenetic changes and induce susceptibility to disease. Periodontal diseases are bacterial infections in which predominantly gram negative anaerobic bacteria colonize the sub gingival areas and triggers an inflammatory response that affect the periodontium; periodontitis is a periodontal disease that destroys the tissue and bone surrounding the tooth. Periodontitis is responsible for tooth loss in adults.

Pleuro-pneumopathie révélant une thrombophlébite septique de la veine jugulaire : pensez au syndrome de Lemierre

Infection by Fusobacterium necrophorum, a Gram negative anaerobic bacteria, can lead to the development of Lemierre's syndrome, an uncommon but potentially fatal infection of the internal jugular vein. Since the introduction of antibiotics, the morbidity and mortality associated with this syndrome have been dramatically reduced. This syndrome is characterized by a pharyngeal infection, which leads to the development of septic thrombophlebitis of the internal jugular vein with septic emboli, which usually spread into the lung. Sometimes the syndrome can be revealed by other unusual clinical symptoms. We present the case of a young patient with an atypical pleural infection associated with pharyngeal infection and thrombosis from the internal jugular vein. The diagnosis of Lemierre's syndrome is mainly clinical, based on a range of suggesting symptoms. Confirmation and monitoring of the condition can be done by ultra-sound and/or contrast enhanced computed tomography. Treatment is based on long-term, high-dose antibiotic therapy and eventually surgical drainage of the infected collection with surgical excision of the internal jugular vein where there is extensive thrombosis. The important message is that in the context of a young patient without comorbidity, who presents with a significant infectious pleurisy, it is important to consider this clinical complication.

Microbiology of Dental Implants: a Review of Literature

Root form dental implants have a high success rate and are commonly used for replacement of missing teeth, however failures occasionally occurs, such implants must be removed. Like teeth dental implants also establish micro flora soon after placement and stable implants showed no significant shifts in the composition, whereas failing implants showed presence of gram negative anaerobic bacteria. This article reviews the micro flora associated with dental implants.

Anaerobic and Aero Tolerant Bacterial Profile of Halitosis

Bad breath "halitosis" is a frequent unpleasant odor of breath. Bad breath is infected by gram negative anaerobic bacteria in tongue coating. These bacteria have a tendency of producing foul-smelling sulphur containing gases called volatile sulphur compounds (VSCs). Both anaerobic and aero tolerant bacteria associated with human halitosis condition are being reported. The profile includes (Prevotella intermedia (6.66%), Porphyromonas endontalis (10%) and Veillonella spp. (13.3%). (Erysipelothrix rhusiopathiae (13.3%), Streptococcus salivarius (13.3%) and Streptococcus oralis (10%). This profile consists of commonal, soft tissue and hard tissue associated pathogen as well as an animal associated pathogens.

Association between Periodontitis and Alzheimer's Disease.

Alzheimer's disease (AD) is a neurodegenerative disease which significantly increases with age. Its onset can be either early or late. AD is characterized by the salient inflammatory features, microglial activation, and increased levels of proinflammatory cytokines which contribute to the inflammatory status of the central nervous system (CNS). Whereas, periodontitis is a common oral infection associated with the gram negative anaerobic bacteria. Periodontitis can be marked as a “low-grade systemic disease” by release of proinflammatory cytokines into systemic circulation and elevation of C-reactive protein (CRP). Inflammation is known to play a pivotal role in both the disease process serving as a connecting link between periodontitis and AD. The present review throws a light on possible enigmatic link between AD and periodontitis. This review is designed by collecting data from PubMed database using key words like “Alzheimer's disease”, “inflammation”, “periodontitis”, and “proinflammatory cytokines”.

Periodontal Vaccine—A Boon In Periodontics

Periodontal disease though is multifactorial it is thought to be caused by group of gram negative anaerobic bacteria resulting in destruction of periodontal ligament and alveolar bone. The current treatment of periodontitis is non specific and is centered on removal of supragingival and subgingival plaque by mechanical debridement and surgical procedures. Due to its high prevalence rate this disease has created an innovative interest to find a solution in the form of vaccine. The search for periodontal vaccine revolves around the antigenic factors of the periodontal pathogens. The objective of periodontal vaccine is to identify the antigens involved in the destructive process of periodontitis against which antibodies would be evoked to exert protection. It also aims to induce mucosal antibody response with little or moderate doses of vaccine. Till date no preventive modality exists for periodontal disease and treatment rendered is palliative. Thus availability of periodontal vaccine would not only prevent and modulate periodontal disease but also enhance the quality of life for whom periodontal treatment cannot be easily obtained.

Etiology of Diabetic Foot Infection in Patients with Poorly Controlled Diabetes

SummaryThe aim of the study was to define the spectrum and susceptibility of microorganisms, isolated from diabetic foot ulcers in patients with poorly controlled diabetes, treated at the clinic of surgery, and compare microbial findings of specimens collected superficially and from deep tissues. The study included 19 patients with type 1 and 2 diabetes with clinical signs of infection. All patients were with poorly controlled diabetes and staged from 3rd to 5th grade according to the Wagner diabetic foot scale. Swab samples from non-debrided wounds and biopsy samples from deep tissues were collected from each patient. Specimens were inoculated on media for isolation of aerobic and anaerobic bacteria. Identification and susceptibility testing of the isolated oiganisms were performed by conventional methods, and VITEK 2 and mini API Systems (bioMerieux, France). A total of 88 bacterial isolates were cultured, comprising 56 clinical strains. Gram positive bacteria were the most common isolated organisms (53.57%), followed by Gram negative bacteria (26.78%) and anaerobic bacteria (19.64%). Staphylococcus aureus was the most common organism detected (10 strains), followed by Enterococcus spp. (7 strains), Escherichia coli (7 strains), Bacteroides spp. (6 strains) and various other organisms of low incidence. Polymicrobial infection was detected in 17 (89.47%) of the patients. In most of the cases infections were caused by 3 bacterial species. Mixed aerobic/anaerobic infections were detected in 9 (47.3%) patients. In 15 (78.94%) patients, there was a coincidence of bacterial findings from superficial and deep tissue samples. The strains isolated were susceptible to commonly used antimicrobials for treatment of diabetic foot infection. The predominant part of the diabetic foot infections were polymicrobial, caused by association between two or three microbial species. In half of the cases the infection was mixed. There was a good correlation between microbial findings from superficial swabs and deep tissue specimens when they were delivered to the microbiology laboratory immediately after collection.

Antimicrobial effect of <i>Anacardium occidentale</i> leaf extract against pathogens causing periodontal disease

The oral cavity is perpetually colonized by different species of microorganisms and at times it is difficult to characterize the periodontal pathogen causing breakdown of tissue and bone. But over the years, based on scientific knowledge, it has been observed that various gram negative anaerobic bacteria have been involved with the initiation of periodontal disease. Based on literature reviews, a study was undertaken to investigate the antimicrobial effect of Anacardium occidentale (cashew) leaf extract on Porphyromonas gingivalis and Prevotella intermedia. Methanol and aqueous extracts of cashew leaves were prepared. Its antimicrobial activity against P. gingivalis and P. intermedia was tested using the agar diffusion method at various dilutions of 75 μ, 50 μl, 25 μl, 10 μl and 5 μl respectively. 0.2% Clorhexidine gluconate (CHX) was used as control. Cultures of P. gingivalis and P. intermedia strains were maintained on Kanamycin blood agar. The agar plates were then incubated at 37?C for 72 hours after which the zone of inhibition was measured and the mean was recorded for each test solution. The results of this study demonstrated that, for both P. gingivalis and P. intermedia, the highest concentration (75 μl) of both the extracts showed maximum antimicrobial action. For P. ginigvalis, the aqueous extract demonstrated significant inhibitory activity compared to the methanolic extract (p = 0.005), which was comparable to that of CHX. For P. intermedia, similar results were observed with aqueous extract being more effective compared to methanolic (p = 0.007), however, CHX was most effective compared to both the extracts (p = 0.007). This study revealed that Anacardium occidentale leaf extracts have efficient antimicrobial activity against P. gingivalis & P. intermedia. Hence, this preliminary study suggests that the antimicrobial action of A. occidentale leaf could be utilized for the preparation of chemical plaque control formulations.

Reactive oxygen species in periodontitis

Recent epidemiological studies reveal that more than two-third of the world's population suffers from one of the chronic forms of periodontal disease. The primary etiological agent of this inflammatory disease is a polymicrobial complex, predominantly Gram negative anaerobic or facultative bacteria within the sub-gingival biofilm. These bacterial species initiate the production of various cytokines such as interleukin-8 and TNF-α, further causing an increase in number and activity of polymorphonucleocytes (PMN) along with these cytokines, PMNs also produce reactive oxygen species (ROS) superoxide via the respiratory burst mechanism as the part of the defence response to infection. ROS just like the interleukins have deleterious effects on tissue cells when produced in excess. To counter the harmful effects of ROS, human body has its own defence mechanisms to eliminate them as soon as they are formed. The aim of this review is to focus on the role of different free radicals, ROS, and antioxidants in the pathophysiology of periodontal tissue destruction.