Growth of aerobic and anaerobic bacteria in agar subjected to freezing and diurnal freezing and thawing

Aerobic and anaerobic bacteria growth in agar after freezing and diurnal freezing and thawin

Black-pigmented anaerobic bacteria associated with ovine periodontitis

Periodontitis is a polymicrobial infectious disease that causes occlusion change, tooth loss, difficulty in rumination, and premature culling of animals. This study aimed to detect species of the genera Porphyromonas and Prevotella present in the periodontal pocket of sheep with lesions deeper than 5mm (n=14) and in the gingival sulcus of animals considered periodontally healthy (n=20). The presence of microorganisms was evaluated by polymerase chain reaction (PCR) using specific primers for Porphyromonas asaccharolytica, Porphyromonas endodontalis, Porphyromonas gingivalis, Porphyromonas gulae, Prevotella buccae, Prevotella intermedia, Prevotella loescheii, Prevotella melaninogenica, Prevotella nigrescens, Prevotella oralis, and Prevotella tannerae. Prevalence and risk analysis were performed using Student's t-test and Spearman's correlation. Among the Prevotella and Porphyromonas species detected in the periodontal lesions of sheep, P. melaninogenica (85.7%), P. buccae (64.3%), P. gingivalis (50%), and P. endodontalis (50%) were most prevalent. P. gingivalis (15%) and P. oralis (10%) prevailed in the gingival sulcus. P. gulae and P. tannerae were not detected in the 34 samples studied. Data evaluation by t-test verified that occurrence of P. asaccharolytica, P. endodontalis, P. gingivalis, P. buccae, P. intermedia, P. melalinogenica, and P. nigrescens correlated with sheep periodontitis. The findings of this study will be an important contribution to research on pathogenesis of sheep periodontitis and development of its control measures

Possibility of growth of airborne microbes in the Jovian atmosphere

Efforts to show growth activity of anaerobic bacteria in aerosolized particles suspended in anaerobic gas (N2) are described. Evidence of spore generation in nitrogen was obtained. Results are discussed

The antibiotic sensitivity patterns and plasmid DNA content of gram-negative anaerobic bacteria isolated in Palmerston North, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Masters in Science at Massey University

One hundred and seven Gram-negative bacteria, including 65 Bacteroides species, 28 fusobacteria and 14 veillonellae were isolated from 17 oral infections treated in two dental surgeries in Palmerston North. These bacteria, plus 37 isolates belonging to the B. fragilis group received from Palmerston North hospital, were surveyed for their antibiotic sensitivity levels, and their plasmid DNA content. The hospital isolates of the B. fragilis group were found to have sensitivity levels comparable with those of B. fragilis group isolates reported in the literature recently. The oral isolates were more sensitive to penicillin, cefoxitin, and tetracycline than isolates of the same species reported in the literature. Half the hospital isolates had plasmids, which were all between 8.5 and 2.7 kilobases (kb) in size except for one 60, and one 43 kb plasmid. Comparatively few of the oral anaerobes had plasmids. One Fusobacterium russii isolate had four plasmids, and five Bacteroides isolates had one plasmid each. These five Bacteroides isolates came from two specimens, R5 and R6. Restriction enzyme analysis of all plasmids revealed that the three 5.6 kb plasmids from sample R5 may be related to a group of 5.8 kb plasmids harboured by four of the hospital isolates. Two different species of Bacteroides isolated from sample R5 harboured the 5.6 kb plasmid, and two species of the B. fragilis group bacteria harboured the 5.8 kb plasmid. Plasmid DNA isolated from two tetracycline resistant hospital isolates was used to transform restriction negative E. coli to a low level of tetracycline resistance

Biology of anaerobic bacteria

Sulfate reducing bacteria of the genus DESULFOVIBRIO and homoacetogenic bacteria of the genus SPOROMUSA were sensitive to changes of hydrogen concentrations during the growth on an organic substrate. Increase of hydrogen concentrations competitively inhibited the organic substrate degradation and decrease of hydrogen concentration inhibited the respiration and the reduction of the external electron acceptor. Such hydrogen sensitive strains which seem to intermediarily produce and consume hydrogen ("hydrogen-cycling") were cultivated in the presence of a second hydrogen oxidizer. Both organisms competed for the hydrogen excreted by the first strain. The competence for H2-oxidation of the strains depended not only on hydrogenase affinities but also on the free energy change of H2-oxidation differing with the respective electron acceptors. (Résumé d'auteur

Degradation of BTEX by anaerobic bacteria: physiology and application

Pollution of the environment with aromatic hydrocarbons, such as benzene, toluene, ethylbenzene and xylene (so-called BTEX) is often observed. The cleanup of these toxic compounds has gained much attention in the last decades. In situ bioremediation of aromatic hydrocarbons contaminated soils and groundwater by naturally occurring microorganisms or microorganisms that are introduced is possible. Anaerobic bioremediation is an attractive technology as these compounds are often present in the anoxic zones of the environment. The bottleneck in the application of anaerobic techniques is the lack of knowledge about the anaerobic biodegradation of benzene and the bacteria involved in anaerobic benzene degradation. Here, we review the existing knowledge on the degradation of benzene and other aromatic hydrocarbons by anaerobic bacteria, in particular the physiology and application, including results on the (per)chlorate stimulated degradation of these compounds, which is an interesting new alternative option for bioremediatio

Study on porphyromonas gingivalis- and porphyromonas endodontalis- mediated signaling pathway

It is known that anaerobic microbes like Porphyromonas gingivalis (P. gingivalis) are involved in the progression and initiation of multiple forms of periodontal disease such as chronic periodontitis. However, in order to culture this gram-negative anaerobic microbes in the laboratory we need a long time (about 72 hours) with a complete absence of oxygen (≤0.001%) to reach optimal cell density. Therefore it is usually treated in an anaerobic chamber. Because this traditional method to culture P. gingivalis is costly and time consuming, we tried to elaborate in this study a new, rapid and less expensive method for culturing the anaerobes, such as P. gingivalis and P. endodontalis. With the use of a rotary shaker under anaerobic conditions, it would seal the bacterial growth media from oxygen exposure using a mineral oil overlay. Additional analysis by western blot helped us to study more about the cell’s biological functions. As a result, we found that the RAW264.7 cells treated by P. gingivalis or P. endodontalis showed three groups of kinase phosphorylation levels. As these kinases are key factors for the bacteria induced inflammation, we are interested to find how to reduce such bacteria (i.e. P. gingivalis and P. endodontalis) induced inflammation via regulation of these related kinase phosphorylation in future studies. Based on our experiment, we believe that this method can be suitable for growing most species of anaerobic bacteria. Thus, we envision that this new method could be widely used in areas of both research and industry in the near future

Hydrogen production by mixed culture of several facultative bacteria and anaerobic bacteria

AbstractThe characteristic of hydrogen production by facultative anaerobic bacteria, obligate anaerobic bacteria and their mixed culture was studied by the batch culture method. The results showed that, due to the synergistic effect between facultative bacteria and anaerobic bacteria, the ability of hydrogen production in the mixed culture was much better than that in the pure culture. Especially, the culture Scheme No.7 mixed up with three strains (Bacterium. E: Bacterium. B: Bacterium. P = 1:1:1) not only had the best hydrogen production capacity (1.885 mol H2/mol glucose) and maximum average hydrogen production rate (212.2 mL/(L·h)), but also had stable hydrogen production under continuous culture conditions, which was 1.968 mol H2/mol glucose

Antimicrobial use Guidelines for Treatment of Respiratory Tract Disease in Dogs and Cats: Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases

Respiratory tract disease can be associated with primary or secondary bacterial infections in dogs and cats and is a common reason for use and potential misuse, improper use, and overuse of antimicrobials. There is a lack of comprehensive treatment guidelines such as those that are available for human medicine. Accordingly, the International Society for Companion Animal Infectious Diseases convened a Working Group of clinical microbiologists, pharmacologists, and internists to share experiences, examine scientific data, review clinical trials, and develop these guidelines to assist veterinarians in making antimicrobial treatment choices for use in the management of bacterial respiratory diseases in dogs and cats.M.R. Lappin, J. Blondeau, D. Boothe, E.B. Breitschwerdt, L. Guardabassi, D.H. Lloyd, M.G. Papich, S.C. Rankin, J.E. Sykes, J. Turnidge, and J.S. Wees