Purpose: Actinomyces israelii is known as the key species to cause classical actinomycosis. Although A. israelii is frequently isolated from human oral cavities, the distribution of this microorganism has been little ...Purpose: Actinomyces israelii is known as the key species to cause classical actinomycosis. Although A. israelii is frequently isolated from human oral cavities, the distribution of this microorganism has been little reported. The purpose of the present study was to develop selective media (AISM) for the isolation of A. israelii and to assess the prevalence of this organism in the oral cavity. Methods: To examine the bacterial population in the oral cavity, a novel selective medium (AISM) was developed for isolating A. israelii. AISM consists of BHI, yeast extract, agar, ofloxacin, fosfomycin, colistin, and sodium fluoride. Results: A. israelii strains grew well on AISM. A. israelii was detected in all dental plaque samples collected from 20 subjects and the mean number of this organism in the samples was 7.9 × 104 CFU/ml. Conclusion: These results indicated that the selective medium was useful for the isolation of A. israelii and this organism was a part of the normal flora in the human oral cavity.展开更多
We present an unusual case of esophageal actinomycosis that developed in a patient with normal immunity and a history of acute SARS-CoV-2 infection. We report a case of a 56-year-old female patient without chronic deg...We present an unusual case of esophageal actinomycosis that developed in a patient with normal immunity and a history of acute SARS-CoV-2 infection. We report a case of a 56-year-old female patient without chronic degenerative pathologies with a history of non-severe acute SARS-CoV-2 infection that occurred two months prior to her presentation, treated with prednisone and betamethasone orally and inhaled, respectively for 21 days. The pivotal symptom is dysphagia and definitive diagnosis requires a tissue culture of the affected organ or a biopsy that shows the classic sulfur granules. Currently, antibiotic treatment with beta-lactams, such as amoxicillin/clavulanic acid, is still effective, as it was in our patient.展开更多
Actinomycetes are relatively prevalent bacteria in the ocean,constituting 9% of the total number of marine bacteria.The advancement of science and technology has led to a more profound exploration of marine actinomyce...Actinomycetes are relatively prevalent bacteria in the ocean,constituting 9% of the total number of marine bacteria.The advancement of science and technology has led to a more profound exploration of marine actinomycetes.These studies hold immense significance in comprehending the distribution and adaptation of marine actinomycetes within the oceanic environment,as well as uncovering new secondary metabolites.Based on differing lifestyles,marine actinomycetes can be categorized as free-living or co-epiphytic.The activity and metabolism of actinomycetes vary across diverse marine settings,including the deep sea,benthic regions,and marine organisms.Due to their distinctive biological traits and genetic background,these marine actinomycetes inevitably generate metabolites possessing unique structures.Research methodologies concerning marine actinomycetes predominantly encompass traditional pure culture techniques,molecular biology approaches,and the integration of metagenomics and bioinformatics.The exploration of varied methodologies proves pivotal for the analysis of metabolite processes.Through the cultivation of marine actinomycetes,numerous compounds featuring novel structures and significant activities have been isolated,furnishing a substantial foundation for new drug investigations.These encompass,but are not restricted to,peptides,antibiotics,terpenoids,ketones,quinones,macrolides,and pigments.The potential applications of marine actinomyces and their secondary metabolites extend beyond antibacterial and anti-tumor effects,exhibiting promising prospects in antifungal and antiviral domains.This paper provides a comprehensive review of the classification,resources,research methodologies,and habitats of marine actinomycetes.Furthermore,it delves into the classification of secondary metabolites and their functional activities,facilitating a more exhaustive analysis of the secondary metabolites produced by marine actinomycetes.展开更多
Actinomycosis is an uncommon chronic infectious disease. Common sites of involvement include the cervicofacial, thoracic and abdominopelvic regions. In abdominopelvic actinomycosis, the ileocecal region, including the...Actinomycosis is an uncommon chronic infectious disease. Common sites of involvement include the cervicofacial, thoracic and abdominopelvic regions. In abdominopelvic actinomycosis, the ileocecal region, including the appendix, is the most commonly involved site. In some reports, limited appendiceal actinomycosis has revealed a thickened appendiceal wall with peri-appendiceal inflammation as acute appendicitis or perforated appendicitis. We experienced pathologically confirmed intraluminal limited appendiceal actinomycosis without peri-appendiceal infiltration. Here, we report the computed tomography and ultrasound findings.展开更多
Peroxidases (POXs) are the key extracellular enzymes produced by crude oil degrading microbes. Knowledge of optimum conditions for POXs activity is crucial for providing effective environment for bioremediation. In th...Peroxidases (POXs) are the key extracellular enzymes produced by crude oil degrading microbes. Knowledge of optimum conditions for POXs activity is crucial for providing effective environment for bioremediation. In this study, physicochemical properties of POXs produced by Actinomyces israelii and Actinomyces viscosus during growth on crude oil were studied. The POXs exhibited similarities in activity and stability with striking differences in response to two divalent metal ions. The POXs from both species had optimum pH of 7.0 and were very stable over a narrow pH range (6.0 - 8.0). The POXs demonstrated similar thermostability exhibiting relative residual activity of 62% at 50°C after 30 min incubation and 45% residual activity at the same temperature after 60 min despite the fact that POXs from A. viscosus and A. israelii had optimum temperatures of 50°C and 40°C, respectively. The POXs from A. viscosus and A. israelii were greatly activated by Fe2+ at 5.0 and 10.0 mM. The enzymes were both strongly inhibited by Cu2+, Mg2+ and Hg2+. Surprisingly, these congeneric POXs demonstrated striking differences in their response to Ca2+ and Mn2+. POX from A. viscosus was activated by Ca2+ and Mn2+ exhibiting relative activity of 136% and 106% at 5 mM, respectively. In contrast, POX from A. israelii was strongly inhibited by Ca2+ and Mn2+ exhibiting 62.5% relative activity in the presence of 5 mM of each metal ion. Increasing the concentration of Ca2+ and Mn2+ led to further activation of POX from A. viscosus and inhibition of POX from A. israelii. Results provide deeper insights into functional properties of studied POXs from closely related microbes. The physicochemical properties are very similar;however, notable differences provide a strong basis for structural characterization of these congeneric enzymes.展开更多
文摘Purpose: Actinomyces israelii is known as the key species to cause classical actinomycosis. Although A. israelii is frequently isolated from human oral cavities, the distribution of this microorganism has been little reported. The purpose of the present study was to develop selective media (AISM) for the isolation of A. israelii and to assess the prevalence of this organism in the oral cavity. Methods: To examine the bacterial population in the oral cavity, a novel selective medium (AISM) was developed for isolating A. israelii. AISM consists of BHI, yeast extract, agar, ofloxacin, fosfomycin, colistin, and sodium fluoride. Results: A. israelii strains grew well on AISM. A. israelii was detected in all dental plaque samples collected from 20 subjects and the mean number of this organism in the samples was 7.9 × 104 CFU/ml. Conclusion: These results indicated that the selective medium was useful for the isolation of A. israelii and this organism was a part of the normal flora in the human oral cavity.
文摘We present an unusual case of esophageal actinomycosis that developed in a patient with normal immunity and a history of acute SARS-CoV-2 infection. We report a case of a 56-year-old female patient without chronic degenerative pathologies with a history of non-severe acute SARS-CoV-2 infection that occurred two months prior to her presentation, treated with prednisone and betamethasone orally and inhaled, respectively for 21 days. The pivotal symptom is dysphagia and definitive diagnosis requires a tissue culture of the affected organ or a biopsy that shows the classic sulfur granules. Currently, antibiotic treatment with beta-lactams, such as amoxicillin/clavulanic acid, is still effective, as it was in our patient.
文摘Actinomycetes are relatively prevalent bacteria in the ocean,constituting 9% of the total number of marine bacteria.The advancement of science and technology has led to a more profound exploration of marine actinomycetes.These studies hold immense significance in comprehending the distribution and adaptation of marine actinomycetes within the oceanic environment,as well as uncovering new secondary metabolites.Based on differing lifestyles,marine actinomycetes can be categorized as free-living or co-epiphytic.The activity and metabolism of actinomycetes vary across diverse marine settings,including the deep sea,benthic regions,and marine organisms.Due to their distinctive biological traits and genetic background,these marine actinomycetes inevitably generate metabolites possessing unique structures.Research methodologies concerning marine actinomycetes predominantly encompass traditional pure culture techniques,molecular biology approaches,and the integration of metagenomics and bioinformatics.The exploration of varied methodologies proves pivotal for the analysis of metabolite processes.Through the cultivation of marine actinomycetes,numerous compounds featuring novel structures and significant activities have been isolated,furnishing a substantial foundation for new drug investigations.These encompass,but are not restricted to,peptides,antibiotics,terpenoids,ketones,quinones,macrolides,and pigments.The potential applications of marine actinomyces and their secondary metabolites extend beyond antibacterial and anti-tumor effects,exhibiting promising prospects in antifungal and antiviral domains.This paper provides a comprehensive review of the classification,resources,research methodologies,and habitats of marine actinomycetes.Furthermore,it delves into the classification of secondary metabolites and their functional activities,facilitating a more exhaustive analysis of the secondary metabolites produced by marine actinomycetes.
文摘Actinomycosis is an uncommon chronic infectious disease. Common sites of involvement include the cervicofacial, thoracic and abdominopelvic regions. In abdominopelvic actinomycosis, the ileocecal region, including the appendix, is the most commonly involved site. In some reports, limited appendiceal actinomycosis has revealed a thickened appendiceal wall with peri-appendiceal inflammation as acute appendicitis or perforated appendicitis. We experienced pathologically confirmed intraluminal limited appendiceal actinomycosis without peri-appendiceal infiltration. Here, we report the computed tomography and ultrasound findings.
文摘Peroxidases (POXs) are the key extracellular enzymes produced by crude oil degrading microbes. Knowledge of optimum conditions for POXs activity is crucial for providing effective environment for bioremediation. In this study, physicochemical properties of POXs produced by Actinomyces israelii and Actinomyces viscosus during growth on crude oil were studied. The POXs exhibited similarities in activity and stability with striking differences in response to two divalent metal ions. The POXs from both species had optimum pH of 7.0 and were very stable over a narrow pH range (6.0 - 8.0). The POXs demonstrated similar thermostability exhibiting relative residual activity of 62% at 50°C after 30 min incubation and 45% residual activity at the same temperature after 60 min despite the fact that POXs from A. viscosus and A. israelii had optimum temperatures of 50°C and 40°C, respectively. The POXs from A. viscosus and A. israelii were greatly activated by Fe2+ at 5.0 and 10.0 mM. The enzymes were both strongly inhibited by Cu2+, Mg2+ and Hg2+. Surprisingly, these congeneric POXs demonstrated striking differences in their response to Ca2+ and Mn2+. POX from A. viscosus was activated by Ca2+ and Mn2+ exhibiting relative activity of 136% and 106% at 5 mM, respectively. In contrast, POX from A. israelii was strongly inhibited by Ca2+ and Mn2+ exhibiting 62.5% relative activity in the presence of 5 mM of each metal ion. Increasing the concentration of Ca2+ and Mn2+ led to further activation of POX from A. viscosus and inhibition of POX from A. israelii. Results provide deeper insights into functional properties of studied POXs from closely related microbes. The physicochemical properties are very similar;however, notable differences provide a strong basis for structural characterization of these congeneric enzymes.
