Bone infections caused by Gemella haemolysans

Metagenomic Analysis Reveals a Changing Microbiome Associated With the Depth of Invasion of Oral Squamous Cell Carcinoma

The relationship between oral squamous cell carcinoma (OSCC) development and the microbiome has attracted increasing attention. The depth of invasion (DOI) is an important indicator of tumor progression, staging and prognosis, and the change in the oral microbiome based on the DOI is unclear. This report describes the use of metagenomic analyses to investigate the relationship between the oral microbiome and the DOI. Forty patients in different DOI categories were recruited; 10 healthy people served as the control group. Swab samples collected from the participants were subjected to metagenomic analyses, and the oral microbial communities and their functions were investigated. The abundances of Fusobacterium nucleatum, Capnocytophaga sputigena, Porphyromonas endodontalis, and Gemella haemolysans were significantly increased in the patients compared with the controls. The abundances of some bacteria exhibited a stage-related trend. The abundances of P. endodontalis, Gemella morbillorum and G. haemolysans increased with increasing DOI. In contrast, the abundances of Prevotella melaninogenica, Haemophilus parainfluenzae and Neisseria flavescens decreased with increasing DOI. Based on receiver operating characteristic (ROC) curve analysis, eight species were found to have predictive value: Rothia mucilaginosa, P. melaninogenica, H. parainfluenzae, and N. flavescens in the healthy control group and P. endodontalis, G. morbillorum, G. haemolysans and Fusobacterium periodonticum in the high DOI group. In the functional analysis, several metabolic pathways were decreased, whereas flagellar assembly and bacterial chemotaxis showed an increasing trend as the disease progressed. Biofilm formation, flagella, lipopolysaccharide (LPS) and other virulence factors exhibited staging-related changes. These pathogenic pathways and factors had a clear correlation with specific pathogens. In particular, when OSCC progressed to the late stage, microbial diversity and functional potential changed greatly.

Gemella endocarditis

We herein present the case presenting to our facility complaining of a fever of two months duration, who underwent dental procedure. Patient was diagnosed with infective endocarditis secondary to an uncommon bacteria: Gemella haemolysans. Patient was found to have concomitant severe mitral valve regurgitation. Our patient did not have any comorbidity or risk factor beside his dental procedure. Our patient received intravenous antibiotic therapy for six weeks and was scheduled for mitral valve replacement.

A Case Report of Gemella haemolysans Keratitis After Refractive Surgery

Purpose

Systematic review of Gemella haemolysans infection associated with ophthalmology, and to summarize the clinical characteristics of Gemellahaemolysans keratitis after refractive surgery.

Methods

Case report and literature review.

Results

We report an 18-year-old man who developed corneal infection after Trans-PRK, and the culture results of lesion specimens confirmed G. haemolysans keratitis. He was treated with fortified topical antibiotics, and clinical improvement was noted shortly after treatment. Resolution of keratitis was achieved at 1 month. Then, a systematic review of the reported cases of ocular G. haemolysans infection was conducted. We summarized clinical manifestations of G. haemolysans infection in cornea.

Conclusion

We reported a case of G. haemolysans keratitis infection after refractive surgery, and reviewed the literature of ocular G. haemolysans infection.

A Rare Case of Gemella haemolysans Infection of Knee Arthroplasty

Gemella haemolysans is a facultative, catalase-negative, anaerobic, gram-positive cocci. It is known to mostly cause endocarditis, meningitis, peritonitis, and cerebral abscesses. However, it is extremely rare for this organism to cause infections of an orthopedic nature, with only a single report of infection in total knee arthroplasty (TKA). We present a rare case of knee arthroplasty infection caused by G. haemolysans four years after an uncomplicated TKA procedure.

The Microbiomes of Pancreatic and Duodenum Tissue Overlap and Are Highly Subject Specific but Differ between Pancreatic Cancer and Noncancer Subjects

BACKGROUND

In mice, bacteria from the mouth can translocate to the pancreas and impact pancreatic cancer progression. In humans, oral bacteria associated with periodontal disease have been linked to pancreatic cancer risk. It is not known if DNA bacterial profiles in the pancreas and duodenum are similar within individuals.

METHODS

Tissue samples were obtained from 50 subjects with pancreatic cancer or other conditions requiring foregut surgery at the Rhode Island Hospital (RIH), and from 34 organs obtained from the National Disease Research Interchange. 16S rRNA gene sequencing was performed on 189 tissue samples (pancreatic duct, duodenum, pancreas), 57 swabs (bile duct, jejunum, stomach), and 12 stool samples.

RESULTS

Pancreatic tissue samples from both sources (RIH and National Disease Research Interchange) had diverse bacterial DNA, including taxa typically identified in the oral cavity. Bacterial DNA across different sites in the pancreas and duodenum were highly subject specific in both cancer and noncancer subjects. Presence of genus Lactobacillus was significantly higher in noncancer subjects compared with cancer subjects and the relative abundance of Fusobacterium spp., previously associated with colorectal cancer, was higher in cancer subjects compared with noncancer subjects.

CONCLUSIONS

Bacterial DNA profiles in the pancreas were similar to those in the duodenum tissue of the same subjects, regardless of disease state, suggesting that bacteria may be migrating from the gut into the pancreas. Whether bacteria play a causal role in human pancreatic cancer needs to be further examined.

IMPACT

Identifying bacterial taxa that differ in cancer patients can provide new leads on etiologically relevant bacteria.

Gemella haemolysans bacteremia in a patient with secondary peritonitis due to a duodenal ulcer perforation: A case report

We describe a case of Gemella haemolysans septic shock in a 75-year old Japanese male with a duodenal perforation and secondary peritonitis. Blood cultures on admission were positive for Gram-positive and Gram-variable cocci, and G. haemolysans was identified using whole cell matrix-assisted laser desorpition/ionization mass spectrometry (MALDI-TOF MS), with a score value of 2.12. The 16S rRNA sequencing was difficult to use as a diagnostic test because there was more than 99% sequence homology with related bacterial strains. Based on both the biochemical profiles and whole groEL sequence, we concluded that the strain in our patient was G. haemolysans. The patient was successfully treated with a 16-day course of antimicrobials. His clinical condition improved, and no evidence of a relapse of the infection was noted. Although MALDI-TOF MS and 16S rRNA sequencing are useful for identification of the species, the basic biochemical profile is also important to identify a rare species.