Infectious Granulomatous Dermatitis Associated With Rothia mucilaginosa Bacteremia: A Case Report

Ionizing radiation improves skin bacterial dysbiosis in cutaneous T-cell lymphoma

Introduction

Cutaneous T-cell lymphoma (CTCL) is closely associated with the host microbiome. While recent evidence suggests that shifts in specific bacterial taxa are associated with response to UV-B, a form of non-ionizing radiation, the impact of ionizing radiation (IR) has not been investigated.

Methods

16S rRNA and tuf gene amplicon sequencing were performed on DNA extracted from swabs of lesional/non-lesional skin of 12 CTCL patients before/after TSEBT or local IR and from 25 matched healthy controls (HC). Microbial diversity and taxonomic profiles were analyzed.

Results

Radiation exposure increased CTCL skin α-diversity to levels approximating HC. TSEBT appeared to carry the greatest effect compared to local IR. Both α and β-diversity differed significantly post versus pre-IR for TSEBT, but not for local IR. IR was associated with decreases in known pathogenic bacteria such as Streptococcus and S. aureus and increases in healthy commensal bacteria such as Anaerococcus, Bifidobacterium and commensal staphylococci including S. pettenkoferi. Substantially more taxa shifts were seen with TSEBT versus local IR.

Discussion

IR not only eliminates CTCL lesions via induction of apoptosis, but also facilitates skin barrier restoration and recolonization of bacterial taxa associated with a healthy skin microbiome. Local IR does not have as strong an effect on the skin microbiome as TSEBT. As skin microbiota act as immunomodulators with local and potentially systemic influence, TSEBT may also improve CTCL lesions via global effects on the skin microbiome. Future larger-scale studies are required to fully elucidate the relationship between cutaneous microbes and IR treatment in CTCL.

High Inborn Errors of Immunity Risk in Patients with Granuloma

OBJECTIVE

Granuloma etiology includes infections, vasculitis, chemicals, malignancies, lymphoproliferative disorders, and immunological diseases. We hypothesized that patients with granuloma have an underlying primary immunodeficiency disease (PIDD).

PATIENTS AND METHODS

We retrospectively enrolled 82 patients with immunological evaluation among 294 biopsy-proven granuloma patients (0- to 20-year-old). At the same time frame, we followed up with 1910 patients in the same age group.

RESULTS

Out of 82 patients, male/female ratio was 45/37. Median age at symptom onset was 5 years (28 days-17.4 years), age of granuloma at diagnosis was 8.6 years (36 days-19.4 years). Common symptoms at disease onset were fever (23.2%), lymphadenopathy (19.6%), abdominal pain (12.2%), and cough (12.2%). Granuloma was frequent in lymph nodes (26.8%), skin (19.5%), lung (13.4%), and bone (11%). Common infectious agents isolated were Mycobacterium spp. (23.2%) and EBV (4.9%). We document PIDD in 76.8% (63/82) of patients. 49.4% (40/81) of immunologically evaluated granuloma patients had hypogammaglobulinemia. Granuloma rate in pediatric PIDD was 3.3%(63/1910). Patients with multiple granulomas (n = 16) had a PIDD diagnosis. Lung involvement was three times more in PIDD. Brain involvement was only seen in PIDD. Fibroadipose tissue and liver involvement were more frequent in patients without documented PIDD and patients whose evaluation was not completed. The mortality rate in PIDD with granuloma was 15.9%, whereas there was no mortality in patients without PIDD.

CONCLUSION

As documented here, even in a university hospital, the immunologic evaluation ratio is about one-third. We showed high PIDD frequency in children with granuloma, and higher mortality in PIDD with granuloma. Thus, an immunologic evaluation performed meticulously by immunologists is a must for accurate diagnosis and decision of individualized therapeutic options.

Characterization of the Rothia spp. and their role in human clinical infections

The genus Rothia are emerging as opportunistic pathogens associated with various infections in immunocompromised and immunocompetent individuals. This review describes the taxonomy, cell wall structure, pathogenesis, phenotypic and molecular characteristics, clinical diseases, treatment and, as well as, the related genera that may be misidentified by Rothia species.

Rothia spp. infective endocarditis: A systematic literature review

OBJECTIVE

To describe the epidemiological, clinical, microbiological, and therapeutic features and outcomes of Rothia infective endocarditis (RIE) and extracardiac infections (ECRI).

METHODS

We performed a systematic literature review of published cases of RIE and ECRI.

RESULTS

After inclusion of a personal case report, 51 cases of RIE and 215 cases of ECRI were reported. Compared with ECRI patients, RIE patients were significantly more often males (80% versus 59%), intravenous drug users (IVDU) (20% versus 3%), immunocompetent (76% versus 31%), and infected with R. dentocariosa (55% versus 13%) but lacked significant differences with regard to median age (45 years [6-79]), rate of orodental abnormalities (33%), and six-month mortality (14%). Following microbiological documentation, RIE was most often treated with a beta-lactam antibiotic alone (39%) for a median duration of six weeks and required surgery in 39% of cases.

CONCLUSION

RIE is rare and likely secondary to a dental portal of entry or cutaneous inoculation in IVDU. Its prognosis seems to be favorable.

Clinical Detection of Chronic Rhinosinusitis through Next-Generation Sequencing of the Oral Microbiota

Chronic rhinosinusitis (CRS) is the chronic inflammation of the sinus cavities of the upper respiratory tract, which can be caused by a disrupted microbiome. However, the role of the oral microbiome in CRS is not well understood. Polymicrobial and anaerobic infections of CRS frequently increased the difficulty of cultured and antibiotic therapy. This study aimed to elucidate the patterns and clinical feasibility of the oral microbiome in CRS diagnosis. Matched saliva and nasal swabs were collected from 18 CRS patients and 37 saliva specimens from normal volunteers were collected for 16S rRNA sequencing. The α-diversity of the saliva displayed no significant difference between control and CRS patients, whereas the β-diversity was significantly different (p = 0.004). Taxonomic indices demonstrated that Veillonella dispar, Rothia mucilaginosa, and Porphyromonas endodontalis were enriched, while Campylobacter and Cardiobacterium were reduced in the saliva of CRS patients. These microbial markers could significantly distinguish CRS patients from control (AUC = 0.939). It is noted that the 16S rRNA results of the nasal swab were consistent with the nasopharynx aerobic culture, and additionally detected multiple pathogens in CRS patients. In summary, these results indicated these oral microbiomes may provide a novel signal for CRS detection and that NGS may be an alternative approach for CRS diagnosis.

Isolation and identification methods of Rothia species in oral cavities

Rothia dentocariosa and Rothia mucilaginosa which are Gram-positive bacteria are part of the normal flora in the human oral cavity and pharynx. Furthermore, Rothia aeria, which was first isolated from air samples in the Russian space station Mir, is predicted to be an oral inhabitant. Immunocompromised patients are often infected by these organisms, leading to various systemic diseases. The involvement of these organisms in oral infections has attracted little attention, and their distribution in the oral cavity has not been fully clarified because of difficulties in accurately identifying these organisms. A suitable selective medium for oral Rothia species, including R. aeria, is necessary to assess the veritable prevalence of these organisms in the oral cavity. To examine the bacterial population in the oral cavity, a novel selective medium (ORSM) was developed for isolating oral Rothia species in this study. ORSM consists of tryptone, sodium gluconate, Lab-Lemco powder, sodium fluoride, neutral acriflavin, lincomycin, colistin, and agar. The average growth recovery of oral Rothia species on ORSM was 96.7% compared with that on BHI-Y agar. Growth of other representative oral bacteria, i.e. genera Streptococcus, Actinomyces, Neisseria, and Corynebacterium, was remarkably inhibited on the selective medium. PCR primers were designed based on partial sequences of the 16S rDNA genes of oral Rothia species. These primers reacted to each organism and did not react to other non-oral Rothia species or representative oral bacteria. These results indicated that these primers are useful for identifying oral Rothia species. A simple multiplex PCR procedure using these primers was a reliable method of identifying oral Rothia species. The proportion of oral Rothia species in saliva samples collected from 20 subjects was examined by culture method using ORSM. Rothia dentocariosa, Rothia mucilaginosa, and R. aeria accounted for 1.3%, 5.9%, and 0.8% of the total cultivable bacteria number on BHI-Y agar in the oral cavities of all subjects, respectively. It was indicated that among oral Rothia species, R. mucilaginosa is most predominant in the oral cavity of humans. A novel selective medium, ORSM, was useful for isolating each oral Rothia species.

Rothia mucilaginosa prosthetic device infections: a case of prosthetic valve endocarditis

Rothia mucilaginosa is increasingly recognized as an emerging opportunistic pathogen associated with prosthetic device infections. Infective endocarditis is one of the most common clinical presentations. We report a case of R. mucilaginosa prosthetic valve endocarditis and review the literature of prosthetic device infections caused by this organism.

Identification of disulphide stress-responsive extracytoplasmic function sigma factors in Rothia mucilaginosa

Rothia mucilaginosa is known as a member of commensal bacterial flora in the oral cavity and has received attention as a potential opportunistic pathogen. We previously determined the genomic sequence of R. mucilaginosa DY-18, a clinical strain with biofilm-like structures isolated from an infected root canal of a tooth with persistent apical periodontitis. We found that the DY-18 genome had only two sigma factor genes that encoded the primary and extracytoplasmic function (ECF) sigma factors. Genomic analysis on the available database of R. mucilaginosa ATCC 25296 (a type strain for R. mucilaginosa) revealed that ATCC 25296 has three sigma factors: one primary sigma factor and two ECF sigma factors, one of which was highly homologous to that of DY-18. ECF sigma factors play an important role in the response to environmental stress and to the production of virulence factors. Therefore, we first examined gene-encoding sigma factors on R. mucilaginosa genome in silico. The homologous ECF sigma factors found in strains DY-18 and ATCC 25296 formed a distinct SigH (SigR) clade in a phylogenetic tree and their cognate anti-sigma factor has a HXXXCXXC motif known to respond against disulphide stress. Quantitative reverse transcription polymerase chain reaction (PCR) and microarray analysis showed that the transcriptional levels of sigH were markedly up-regulated under disulphide stress in both strains. Microarray data also demonstrated that several oxidative-stress-related genes (thioredoxin, mycothione reductase, reductase and oxidoreductase) were significantly up-regulated under the diamide stress. On the basis of these results, we conclude that the alternative sigma factor SigH of R. mucilaginosa is a candidate regulator in the redox state.

Rothia aeria neck abscess in a patient with chronic granulomatous disease: case report and brief review of the literature

Rothia aeria caused a necrotic lymphadenitis and neck abscess in a patient with CGD. This infection was aggressive, crossed tissue planes, required two surgeries, as well as prolonged antibiotics for complete resolution. Rothia aeria is a rare pathogen that can be added to the spectrum of agents causing disease in CGD, a finding that further reinforces the importance of microbiologic identification of infections in this patient population.

Infections in Leukemia and Hematopoietic Stem Cell Transplantation

Infections are one of the most common complications in patients diagnosed with leukemia and serve as a major obstacle to treatment. Through the early 1970s, infections were the most common cause of death in patients diagnosed with acute leukemia, but improvement in treatment and supportive care over the past few decades, coupled with expanded prophylaxis and prevention regimens, have led to reduction in both the frequency and severity of infections. Regardless, due in part to an aging cancer population and the diversity of cancer treatments and procedures, infectious diseases remain a major cause of morbidity and mortality in patients with leukemia.

Complete Genome Sequence of Rothia mucilaginosa DY-18: A Clinical Isolate with Dense Meshwork-Like Structures from a Persistent Apical Periodontitis Lesion

Rothia mucilaginosa is an opportunistic pathogen in the human oral cavity and pharynx. We found that R. mucilaginosa DY-18, a clinical isolate from a persistent apical periodontitis lesion, had biofilm-like structures. Similar structures were also observed on R. mucilaginosa ATCC25296. To further study these structures, we determined the complete genome sequence of DY-18 and found it a 2.26-Mb chromosome. Regarding stress responsive systems known to affect biofilm formation in many bacteria, DY-18 genome possessed only two sigma factor genes. One of these encoded an additional sigma factor whose promoter-binding activity may be regulated in response to environmental stimuli. Additionally, several genes assigned to two-component signal transduction systems were presented in this genome. To the best of our knowledge, this is the first complete genome of R. mucilaginosa species and our data raise the possibility that this organism regulates the biofilm phenotype through these stress responsive systems.

Nodeomics: pathogen detection in vertebrate lymph nodes using meta-transcriptomics

The ongoing emergence of human infections originating from wildlife highlights the need for better knowledge of the microbial community in wildlife species where traditional diagnostic approaches are limited. Here we evaluate the microbial biota in healthy mule deer (Odocoileus hemionus) by analyses of lymph node meta-transcriptomes. cDNA libraries from five individuals and two pools of samples were prepared from retropharyngeal lymph node RNA enriched for polyadenylated RNA and sequenced using Roche-454 Life Sciences technology. Protein-coding and 16S ribosomal RNA (rRNA) sequences were taxonomically profiled using protein and rRNA specific databases. Representatives of all bacterial phyla were detected in the seven libraries based on protein-coding transcripts indicating that viable microbiota were present in lymph nodes. Residents of skin and rumen, and those ubiquitous in mule deer habitat dominated classifiable bacterial species. Based on detection of both rRNA and protein-coding transcripts, we identified two new proteobacterial species; a Helicobacter closely related to Helicobacter cetorum in the Helicobacter pylori/Helicobacter acinonychis complex and an Acinetobacter related to Acinetobacter schindleri. Among viruses, a novel gamma retrovirus and other members of the Poxviridae and Retroviridae were identified. We additionally evaluated bacterial diversity by amplicon sequencing the hypervariable V6 region of 16S rRNA and demonstrate that overall taxonomic diversity is higher with the meta-transcriptomic approach. These data provide the most complete picture to date of the microbial diversity within a wildlife host. Our research advances the use of meta-transcriptomics to study microbiota in wildlife tissues, which will facilitate detection of novel organisms with pathogenic potential to human and animals.