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UNASSIGNED: Rothia species are known to cause dental caries and periodontal disease, and infrequently cause native or prosthetic valve endocarditis mostly in immunocompromised persons. With an increasing use of implantable cardiac devices, early clinical suspicion and a rapid diagnosis of endocarditis is essential for optimal treatment to reduce complications and mortality. Bacteremic infection with Rothia dentocariosa in immunocompetent persons is uncommon. Pacemaker lead-related endocarditis caused by Rothia spp. is rare and management guidelines are not defined.
UNASSIGNED: We report a rare case of implantable cardiac defibrillator (ICD) lead endocarditis in an immunocompetent patient that was caused by Rothia dentocariosa.
UNASSIGNED: Clinicians should be aware of this rare cause of CIED lead infections and should be acquainted with the optimal strategies of prompt antibiotic therapy and removal of the infected device/leads.

Rothia dentocariosa is a conditionally pathogenic bacterium that may cause infective endocarditis (IE) in selected patients and give rise to a variety of clinical complications, albeit it is not a common IE pathogen. We present the case of a patient diagnosed with Rothia dentocariosa-associated IE secondary to influenza B and thrombocytopenic purpura. The blood culture revealed Rochebacterium caries, cardiac ultrasound detected vegetation, while brain and spleen abscesses manifested and progressively deteriorated. Despite a suboptimal response to anti-infective therapy, the patient ultimately underwent aortic valve replacement. Discharge from the hospital was achieved upon control of the brain abscess and spleen abscess.

Background: Aneurysms of the internal iliac artery in infective endocarditis are extremely rare, with few cases reported in the literature, and Rothia dentocariosa infective endocarditis are rare. Analysis: We describe the case of a previously healthy 62-year-old male who presented a Rothia dentocariosa infective endocarditis. Results: Multi-modality imaging revealed an aneurysm of the left internal iliac artery, which was clinically silent. The patient was treated with antibiotics and semi-emergent bioprosthesis aortic valve replacement. Follow-up multi-modality imaging showed the regression of the aneurysm. Conclusion: This case shows that an aneurysm of the internal iliac artery in infective endocarditis can regress under antibiotherapy alone. This case also highlights the ability of PET/CT to identify and follow such an aneurysm.

OBJECTIVE: Rothia spp. are emerging as significant bacteria associated with oral health, with Rothia dentocariosa being one of the most prevalent species. However, there is a lack of studies examining these properties at the genetic level. This study aimed to establish a genetic modification platform for R. dentocariosa.
METHODS: Rothia spp. were isolated from saliva samples collected from healthy volunteers. Subsequently, R. dentocariosa strains were identified through colony morphology, species-specific polymerase chain reaction (PCR), and 16S ribosomal RNA gene sequencing. The identified strains were then transformed with plasmid pJRD215, and the most efficient strain was selected. Transposon insertion mutagenesis was performed to investigate the possibility of genetic modifications.
RESULTS: A strain demonstrating high transforming ability, designated as R. dentocariosa LX16, was identified. This strain underwent transposon insertion mutagenesis and was screened for 5-fluoroorotic acid-resistant transposants. The insertion sites were confirmed using arbitrary primed PCR, gene-specific PCR, and Sanger sequencing.
CONCLUSIONS: This study marks the first successful genetic modification of R. dentocariosa. Investigating R. dentocariosa at the genetic level can provide insights into its role within the oral microbiome.

A 40-year-old male patient with a history of dental disease was sent to the emergency room mainly for fever, unclear consciousness, and purpura. Computed tomography reveals subarachnoid hemorrhage and blood analysis reveals platelet reduction. The patient was started daily intravenous piperacillin tazobactam glucocorticoid and gamma globulin. Two weeks later, symptoms improved but still had severe complications such as fever, platelet reduction, hepatosplenic abscess, and severe myocardial injury. Subsequently, Rothia dentocariosa was cultured from the blood samples of patient\'s limb. The patient was started on daily injections of tigecycline and penicillin. Ten days later, symptoms improved and amikacin was tried, which was later confirmed to be ineffective in this patient. Cardiac ultrasound revealed aortic valve vegetations and magnetic resonance imaging revealed brain abscess formation. Then, antibiotics were adjusted to vancomycin and meropenem. Finally, the patient underwent valve replacement. Infectious endocarditis - after surgery, vancomycin and meropenem were utilized for a week leading to symptom resolution. The patient was transferred to rehabilitation hospital. This case will provide clinical experience for the treatment of R. dentocariosa.

The growing global threat of antimicrobial resistance is reaching a crisis point as common bacterial infections, including those caused by pathogenic Neisseria species, are becoming increasingly untreatable. This is compelling the scientific community to search for new antimicrobial agents, taking advantage of computational mining and using whole genome sequences to discover natural products from the human microbiome with antibiotic effects. In this study, we investigated the crude extract from a Rothia dentocariosa strain with demonstrated antimicrobial activity against pathogenic Neisseria spp. by spot-on-lawn assay. The genomic DNA of the R. dentocariosa strain was sequenced, and bioinformatic evaluation was performed using antiSMASH and PRISM to search for biosynthetic gene clusters (BGCs). The crude extract with potential antimicrobial activity was run on Tricine-SDS-PAGE, and the putative peptides were characterised using liquid chromatography-tandem mass spectrometry (LC-MS). The crude extract inhibited the growth of the pathogenic Neisseria spp. Six BGCs were identified corresponding to non-ribosomal peptide synthases (NRPSs), polyketide synthases (PKSs), and ribosomally synthesised and post-translationally modified peptides. Three peptides were also identified corresponding to Actinorhodin polyketide putative beta-ketoacyl synthase 1. These findings serve as a useful reference to facilitate the research and development of NRPS and PKS as antimicrobial products against multidrug-resistant N. gonorrhoeae.

Moraxella catarrhalis is found almost exclusively within the human respiratory tract. This pathobiont is associated with ear infections and the development of respiratory illnesses, including allergies and asthma. Given the limited ecological distribution of M. catarrhalis, we hypothesized that we could leverage the nasal microbiomes of healthy children without M. catarrhalis to identify bacteria that may represent potential sources of therapeutics. Rothia was more abundant in the noses of healthy children compared to children with cold symptoms and M. catarrhalis. We cultured Rothia from nasal samples and determined that most isolates of Rothia dentocariosa and \"Rothia similmucilaginosa\" were able to fully inhibit the growth of M. catarrhalis in vitro, whereas isolates of Rothia aeria varied in their ability to inhibit M. catarrhalis. Using comparative genomics and proteomics, we identified a putative peptidoglycan hydrolase called secreted antigen A (SagA). This protein was present at higher relative abundance in the secreted proteomes of R. dentocariosa and R. similmucilaginosa than in those from non-inhibitory R. aeria, suggesting that it may be involved in M. catarrhalis inhibition. We produced SagA from R. similmucilaginosa in Escherichia coli and confirmed its ability to degrade M. catarrhalis peptidoglycan and inhibit its growth. We then demonstrated that R. aeria and R. similmucilaginosa reduced M. catarrhalis levels in an air-liquid interface culture model of the respiratory epithelium. Together, our results suggest that Rothia restricts M. catarrhalis colonization of the human respiratory tract in vivo. IMPORTANCE Moraxella catarrhalis is a pathobiont of the respiratory tract, responsible for ear infections in children and wheezing illnesses in children and adults with chronic respiratory diseases. Detection of M. catarrhalis during wheezing episodes in early life is associated with the development of persistent asthma. There are currently no effective vaccines for M. catarrhalis, and most clinical isolates are resistant to the commonly prescribed antibiotics amoxicillin and penicillin. Given the limited niche of M. catarrhalis, we hypothesized that other nasal bacteria have evolved mechanisms to compete against M. catarrhalis. We found that Rothia are associated with the nasal microbiomes of healthy children without Moraxella. Next, we demonstrated that Rothia inhibit M. catarrhalis in vitro and on airway cells. We identified an enzyme produced by Rothia called SagA that degrades M. catarrhalis peptidoglycan and inhibits its growth. We suggest that Rothia or SagA could be developed as highly specific therapeutics against M. catarrhalis.

Rothia species are gram positive, round to rod-shaped bacteria that are normally oral and respiratory tract flora. They were first isolated in 1967 from dental caries. We present a 69-year-old male with no risk factors for aforementioned bacteria however was found to have thickened anterior leaflet of the mitral valve with a small isoechoic lesion consistent with vegetation on Transthoracic echocardiogram. Blood cultures grew pan sensitive Rothia dentocariosa. Patient was treated with long-term antibiotics. This case adds to the limited number of cases of Rothia dentocariosa Endocarditis.

BACKGROUND: Rothia sp. are Gram-positive bacteria in the class of Actinobacteria that are part of the physiological oral flora. In rare cases, Rothia aeria and Rothia dentocariosa can cause infective endocarditis (IE). The biofilm potential of Rothia in endocarditis is unknown.
METHODS: Specimen from two cases of Rothia endocarditis were obtained during cardiac surgery. One of the patients suffered mitral valve IE from Rothia aeria. In the other case, IE of a prosthetic pulmonary valve was caused by Rothia dentocariosa. Fluorescence in situ hybridization (FISH) was used for visualization of microorganisms within heart valve tissues in combination with PCR and sequencing (FISHseq).
RESULTS: The two heart valve specimens featured mature biofilms of bacteria that were identified by FISHseq as Rothia aeria and Rothia dentocariosa, respectively. FISH showed in situ biofilms of both microorganisms that feature distinct phenotypes for the first time ex vivo. Both of our reported cases were treated successfully by heart valve surgery and antibiotic therapy using beta-lactam antibiotics.
CONCLUSIONS: The biofilm potential of Rothia sp. must be taken into account. The awareness of Rothia aeria and Rothia dentocariosa as rare but relevant pathogens for infective endocarditis must be raised. Use of biofilm-effective antibiotics in Rothia IE should be discussed.