Sequence diversity of the intergenic spacer region of the rRNA gene ofCryptococcus albidusisolated from the skin of patients with atopic dermatitis and healthy individuals

ABSTRACTScant attention has been paid to Lyme disease,Borrelia burgdorferi,Ixodes scapularis, or reservoirs in eastern North Dakota despite the fact that it borders high-risk counties in Minnesota. Recent reports ofB. burgdorferiandI. scapularisin North Dakota, however, prompted a more detailed examination. Spirochetes cultured from the hearts of five rodents trapped in Grand Forks County, ND, were identified asB. burgdorferi sensu latothrough sequence analyses of the 16S rRNA gene, the 16S rRNA gene-ileTintergenic spacer region,flaB,ospA,ospC, andp66. OspC typing revealed the presence of groups A, B, E, F, L, and I. Two rodents were concurrently carrying multiple OspC types. Multilocus sequence typing suggested the eastern North Dakota strains are most closely related to those found in neighboring regions of the upper Midwest and Canada. BALB/c mice were infected withB. burgdorferiisolate M3 (OspC group B) by needle inoculation or tick bite. Tibiotarsal joints and ear pinnae were culture positive, andB. burgdorferiM3 was detected by quantitative PCR (qPCR) in the tibiotarsal joints, hearts, and ear pinnae of infected mice. Uninfected larvalI. scapularisticks were able to acquireB. burgdorferiM3 from infected mice; M3 was maintained inI. scapularisduring the molt from larva to nymph; and further, M3 was transmitted from infectedI. scapularisnymphs to naive mice, as evidenced by cultures and qPCR analyses. These results demonstrate that isolate M3 is capable of disseminated infection by both artificial and natural routes of infection. This study confirms the presence of unique (nonclonal) and infectiousB. burgdorferipopulations in eastern North Dakota.

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Differentiation of group VIII Spiroplasma strains with sequences of the 16S–23S rDNA intergenic spacer region

Canadian Journal of Microbiology ◽

10.1139/w04-091 ◽

2004 ◽

Vol 50 (12) ◽

pp. 1061-1067 ◽

Cited By ~ 14

Author(s):

Laura B Regassa ◽

Kimberly M Stewart ◽

April C Murphy ◽

Frank E French ◽

Tao Lin ◽

...

Keyword(s):

Intergenic Spacer ◽

Analytical Models ◽

23S Rrna ◽

Rrna Gene ◽

Group Viii ◽

Similarity Coefficients ◽

Intergenic Spacer Region ◽

Intergenic Sequences ◽

The Stability ◽

The 16S Rrna Gene

Spiroplasma species (Mollicutes: Spiroplasmataceae) are associated with a wide variety of insects, and serology has classified this genus into 34 groups, 3 with subgroups. The 16S rRNA gene has been used for phylogenetic analysis of spiroplasmas, but this approach is uninformative for group VIII because the serologically distinct subgroups generally have similarity coefficients >0.990. Therefore, we investigated the utility of the 16S–23S rRNA spacer region as a means to differentiate closely related subgroups or strains. We generated intergenic sequences and detailed serological profiles for 8 group VIII Spiroplasma strains. Sequence analyses using Maximum Parsimony, Neighbor Joining, and Maximum Likelihood placed the strains into 2 clades. One clade consisted of strains BARC 2649 and GSU5367. The other clade was divided into clusters containing representatives of the 3 designated group VIII subgroups (EA-1, DF-1, and TAAS-1) and 3 previously unclassified strains. The stability of the positions of the strains in various analytical models and the ability to provide robust support for groupings tentatively supported by serology indicates that the 16S–23S intergenic rDNA sequence will prove useful in intragroup analysis of group VIII spiroplasmas.Key words: Mollicutes, Spiroplasma, phylogeny, Tabanidae.

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Seeing is believing: Can biofilm diagnostics guide individualized therapy in endocarditis?

10.5194/biofilms9-116 ◽

2020 ◽

Author(s):

Judith Kikhney ◽

Laura Kursawe ◽

Swb Eichinger ◽

Walter Eichinger ◽

Julia Schmidt ◽

...

Keyword(s):

Antibiotic Therapy ◽

Biofilm Formation ◽

Heart Valves ◽

Single Cells ◽

Intergenic Spacer ◽

Rrna Gene ◽

Bacterial Cells ◽

Intergenic Spacer Region ◽

Causative Microorganism ◽

The Impact

Introduction In Infective Endocarditis (IE), early diagnosis of the causative microorganism is crucial for correct antibiotic therapy, which improves the patients&#8217; outcome. Objectives We studies the impact of biofilm formation in IE samples. Materials & methods We used Fluorescence in situ Hybridization (FISH) combined with 16S rRNA-gene PCR and sequencing to visualize and identify the infectious agents in native as well as prosthetic valves and to study any biofilm formation. The signal intensity of the fluorescence-labelled FISH probes correlates to a high ribosome content of the bacteria indicating metabolic activity at the time point of surgery. We developed a spacer FISH assay for the detection of the 16S-23S intergenic spacer region that is only present in actively transcribing cells to detect the activity of bacterial cells more precisely on a single cell level. Results FISH visualized bacteria in the heart valves ranging from single cells to highly organized biofilms. Interestingly, we found FISH positive bacteria in culture negative samples and samples from patients under antibiotic therapy. Using the spacer FISH, we visualized positive microbial cells in heart valves of patients under adequate therapy. Preliminary data point to a correlation between the biofilm state and treatment inefficiency. Conclusion FISH/PCR not only allows timely identification of the pathogens in IE, but also biofilm-staging and visualization of the effect of antimicrobial therapy at time of surgery. The technique provides crucial information for successful targeted antibiotic therapy, and it might guide therapeutical decisions in relation to biofilm state in the future.

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