OBJECTIVE: To investigate the risk factors, clinical characteristics, and bacterial resistance of bloodstream infections caused by Streptococcus mitis in children with hematological disease, so as to provide a reference for infection control. METHODS: The clinical information and laboratory findings of pediatric patients complicated with blood cultures positive for Streptococcus mitis from January 2018 to December 2020 in the Institute of Hematology & Blood Diseases Hospital were searched and collected. The clinical characteristics, susceptibility factors, and antibiotic resistance of the children were retrospectively analyzed. RESULTS: Data analysis from 2018 to 2020 showed that the proportion of Streptococcus mitis isolated from bloodstream infections in children (≤14 years old) with hematological diseases was the highest (19.91%) and significantly higher than other bacteria, accounting for 38.64% of Gram-positive cocci, and presented as an increasing trend year by year. A total of 427 children tested positive blood cultures, including 85 children with bloodstream infections caused by Streptococcus mitis who tested after fever. Most children experienced a recurrent high fever in the early and middle stages (≤6 d) of neutropenia and persistent fever for more than 3 days. After adjusting the antibiotics according to the preliminary drug susceptibility results, the body temperature of most children (63.5%) returned to normal within 4 days. The 85 children were mainly diagnosed with acute myeloid leukemia (AML), accounting for 84.7%. The proportion of children in the neutropenia stage was 97.7%. The incidence of oral mucosal damage, lung infection, and gastrointestinal injury symptoms was 40%, 31.8%, and 27.1%, respectively. The ratio of elevated C-reactive protein (CRP) and procalcitonin was 65.9% and 9.4%, respectively. All isolated strains of Streptococcus mitis were not resistant to vancomycin and linezolid, and the resistance rate to penicillin, cefotaxime, levofloxacin, and quinupristin-dalfopristin was 10.6%, 8.2%, 9.4%, and 14.1%, respectively. None of children died due to bloodstream infection caused by Streptococcus mitis. CONCLUSION The infection rate of Streptococcus mitis is increasing year by year in children with hematological diseases, especially in children with AML. Among them, neutropenia and oral mucosal damage after chemotherapy are high-risk infection factors. The common clinical symptoms include persistent high fever, oral mucosal damage, and elevated CRP. Penicillin and cephalosporins have good sensitivity. Linezolid, as a highly sensitive antibiotic, can effectively control infection and shorten the course of disease.
Humans ; Child ; Streptococcal Infections/microbiology* ; Retrospective Studies ; Hematologic Diseases/complications* ; Streptococcus mitis ; Drug Resistance, Bacterial ; Risk Factors ; Microbial Sensitivity Tests ; Anti-Bacterial Agents ; Female ; Male ; Bacteremia/microbiology* ; Child, Preschool ; Adolescent

Septic arthritis is a serious medical condition that can lead to significant complications if misdiagnosed or mismanaged. A rare case of a 1st metatarso-phalangeal joint septic arthritis in a native joint is presented in a patient with no significant risk factors. A 41-year-old patient was referred by his general practitioner owing to ongoing pain and swelling over his native 1st metatarso-phalangeal joint with difficulty on weightbearing for three months. After a series of investigations, including blood tests and a foot magnetic resonance imaging, which were inconclusive, the patient was led to the operating theatre for sampling and washout of his joint. The samples taken in the theatres revealed septic arthritis with Streptococcus mitis as the causative microorganism. The patient was treated with six weeks of oral antibiotics with a good functional outcome. This case report illuminates this rare condition and makes foot and ankle surgeons aware of its existence. A high suspicion for this condition can prevent misdiagnosis and mismanagement.
Adult ; Ankle ; Anti-Bacterial Agents ; Arthritis, Infectious ; Diagnostic Errors ; Foot ; General Practitioners ; Hematologic Tests ; Humans ; Joints ; Magnetic Resonance Imaging ; Risk Factors ; Streptococcus mitis ; Surgeons ; Weight-Bearing

This study aimed to evaluate the antimicrobial effects of Acanthopanax sessiliflorum fruit (ASF; Ogaza) extracts on Streptococcus mutans and Streptococcus sobrinus, which are agents that cause dental caries, and on Streptococcus mitis and Streptococcus salivarius, the microbial flora of the oral cavity. The ASF extracts obtained using 70% ethanol were fractionated in the order of ethyl acetate and n-Butanol, concentrated under reduced pressure, and lyophilized to give powdery solvent extracts. The antimicrobial activity of ASF extracts from each solvent was examined using the disk diffusion method. As a result, only those extracts obtained using an ethyl acetate solvent showed antimicrobial activity. These extracts were selected, and the minimum inhibitory concentration was measured by disk diffusion method at various extract concentrations. Results showed a minimum inhibitory concentration of 32 mg/ml. The viable cell count was measured to confirm the minimum bactericidal concentration. Results showed a minimum bactericidal concentration of 64 mg/ml. In the cytotoxicity test using normal human dermal fibroblast cells, the absorbance value of the test group was similar to that of the control group at 0.64, 1.28, and 6.4 mg/ml. The bacteria and their colonies were examined using a scanning electron microscope. Boundaries between the antimicrobial activity region and non-antimicrobial activity region were observed around the paper disk, which was immersed in the extract with 32 mg/ml concentration. Bacterial colonization was not observed in the area with antimicrobial activity. This finding suggests that ASF extracts can inhibit the growth of some microorganisms in the oral cavity, in addition to the effects of these extracts known to date. In particular, ASF extracts may be used as a preparation for preventing dental caries by adding the extract to the toothpaste or oral mouthwash.
1-Butanol ; Bacteria* ; Cell Count ; Colon ; Dental Caries ; Diffusion ; Eleutherococcus* ; Ethanol ; Fibroblasts ; Fruit* ; Humans ; Methods ; Microbial Sensitivity Tests ; Mouth ; Streptococcus ; Streptococcus mitis ; Streptococcus mutans ; Streptococcus sobrinus ; Toothpastes

BACKGROUND: Cases of infective endocarditis (IE) require prompt etiological diagnosis for effective treatment. Molecular methods can aid in rapid and reliable diagnosis of culture-negative IE cases. We evaluated the utility of 16S rDNA PCR and sequencing in determining the causative agents of IE in valve tissues, especially when specimens were obtained after initiation of antimicrobial therapy. METHODS: We performed 16S rDNA PCR and sequencing in heart valve specimens and medical records review of 80 patients who underwent protocol-based cardiac surgery from 2013 to 2015. One patient did not meet the criteria for IE. Sixty-five (81.3%) and 14 pa-tients (17.5%) were diagnosed as having definite IE and possible IE, respectively. Blood and heart valve biopsy tissue were examined by using routine microbiological methods. RESULTS: Blood cultures in our hospital were IE-positive for 33 patients (41.8%), whereas 49 patients (62.0%) showed positive blood cultures when initial blood cultures performed at the referring hospital were included. Eighteen (22.8%) and 40 patients (50.6%) were IE-positive in valve tissue cultures and 16S rDNA PCR, respectively. Bacteria in the Streptococcus mitis group (n=26) were the most common etiological agents of IE. Eight (10.1%) culture-negative specimens tested positive by 16S rDNA PCR. In five of eight PCR-positive and culture-negative cases, fastidious or anaerobic organisms were the cause of IE. CONCLUSIONS: Direct 16S rDNA PCR and sequencing can be used as a supplementary method to conventional blood and biopsy culture testing, especially in culture-negative IE cases that are negative for IE by culture.
Bacteria ; Biopsy ; Diagnosis* ; DNA, Ribosomal* ; Endocarditis* ; Heart Valves ; Humans ; Medical Records ; Methods ; Polymerase Chain Reaction* ; Streptococcus mitis ; Thoracic Surgery

Human mouth environment is known to include a variety bacteria, including Streptococcus spp., Staphylococcus spp., Actinomyces spp., Lactobacillus spp., Candida spp., Enterobacteriaceae, et al. Human oral microorganisms can cause dental caries, gingivitis, periodontitis, respiratory tract infection, and cardiovascular disease. Thus, right denture cleaning is essential to oral and general human health. The aim of this study was to evaluate the bactericidal effect of a sodium dichloroisocyanurate-based effervescent tablet (Aos Denti Germ, Aos Company, Chungbuk, Korea) against oral microorganisms. A total of 5 species Streptococcus spp. (Streptococcus anginosus, Streptococcus mitis, Streptococcus mutans, Streptococcus oralis, and Streptococcus sobrinus), Actinomyces oris, Candida albicans, and Escherichia coli were used in this study. All strains were exposed to the distilled water prepared with effervescent tablet. After the exposure, the mixture of strains and effervescent tablet was inoculated onto blood agar or MacConkey agar plate and cultured at 36℃. All strains were killed immediately on exposure to effervescent tablet. The results suggested that effervescent tablet could be used as an effective denture cleanser for dental hygiene.
Actinomyces ; Agar ; Bacteria ; Candida ; Candida albicans ; Cardiovascular Diseases ; Chungcheongbuk-do ; Dental Caries ; Denture Cleansers ; Dentures* ; Enterobacteriaceae ; Escherichia coli ; Gingivitis ; Humans ; Lactobacillus ; Mouth ; Oral Hygiene ; Periodontitis ; Respiratory Tract Infections ; Sodium ; Staphylococcus ; Streptococcus ; Streptococcus mitis ; Streptococcus mutans ; Streptococcus oralis ; Water

OBJECTIVES: The usage of medicinal plants as natural antimicrobial agents has grown in many fields including dental medicine. The aim of this in vitro study was three-fold: (i) to determine the chemical compositions of the Ferula gummosa essential oil (FGEO), (ii) to compare the antimicrobial efficacy of the oil with sodium hypochlorite (NaOCl) and chlorhexidine (CHX), (iii) to assess the toxic behavior of FGEO in different concentrations compared to 5% NaOCl and 0.2% CHX. MATERIALS AND METHODS: Gas chromatography/mass spectrometry (GC/MS) was used to determine the chemical compositions of the oil. The disk diffusion method and a broth micro-dilution susceptibility assay were exploited to assess the antimicrobial efficacy against Enterococcus faecalis, Staphylococcus aureus, Streptococcus mitis, and Candida albicans. The cytocompatibility of the FGEO was assessed on L929 fibroblasts, and compared to that of NaOCl and CHX. RESULTS: Twenty-seven constituents were recognized in FGEO. The major component of the oil was beta-pinene (51.83%). All three irrigants significantly inhibited the growth of all examined microorganisms compared to the negative control group. FGEO at 50 microg/mL was effective in lower concentration against Enterococcus faecalis than 5% NaOCl and 0.2% CHX, and was also more potent than 0.2% CHX against Candida albicans and Staphylococcus aureus. FGEO was a cytocompatible solution, and had significantly lower toxicity compared to 5% NaOCl and 0.2% CHX. CONCLUSIONS: FGEO showed a promising biological potency as a root canal disinfectant. More investigations are required on the effectiveness of this oil on intracanal bacterial biofilms.
Anti-Infective Agents ; Biofilms ; Candida albicans ; Chlorhexidine ; Dental Pulp Cavity ; Diffusion ; Enterococcus faecalis ; Ferula* ; Fibroblasts ; Plants* ; Plants, Medicinal ; Sodium Hypochlorite ; Spectrum Analysis ; Staphylococcus aureus ; Streptococcus mitis

Botryomycosis is an uncommon chronic suppurative bacterial infection of the skin and visceral organs seen primarily in immunocompromised patients. Here, we report a case of splenic botryomycosis caused by Streptococcus mitis in a 53-year-old immunocompetent woman with a history of distal gastrectomy for advanced gastric cancer.
Bacterial Infections ; Female ; Gastrectomy* ; Humans ; Immunocompromised Host ; Middle Aged ; Skin ; Spleen ; Stomach Neoplasms ; Streptococcus mitis*

We report a rare case of tricuspid valve and pulmonary valve endocarditis associated with a double-chambered right ventricle in an adult female with pulmonary artery aneurysm and septic pulmonary embolism by Streptococcus mitis. She was treated with aggressive antibiotic therapy followed by debridement of the infective lesion of tricuspid valve, pulmonary valve replacement using xenograft and resection of obstructing muscular bundles in right ventricle.
Adult ; Aneurysm ; Debridement ; Endocarditis* ; Endocarditis, Bacterial ; Female ; Heart Defects, Congenital ; Heart Ventricles* ; Heterografts ; Humans ; Pulmonary Artery ; Pulmonary Embolism ; Pulmonary Valve* ; Streptococcus mitis ; Tricuspid Valve

Dental professionals are repeatedly exposed to many microorganisms present in both blood and saliva. Thus, dental professionals are at a greater risk of acquiring and spreading infections, and the implementation of infections control guidelines is necessary. Cellular phones have become a necessary device for communicating in hospitals. Cellular phones contaminated with bacteria may serve as a fomite in the transmission of pathogens by the hands of medical personnel. Nevertheless, studies about rate and levels of bacterial contamination of cellular phones have been extremely limited with regards to dental personnel. The purpose of this study was to identify bacterial flora on the cellular phones of dentists by a molecular biological method using the 16S rRNA cloning and sequencing method. We acquired total 200 clones from dentists' cell phones and identified the bacterial species. Pseudomonas (34.6%), Lactobacillus (18.5%), Azomonas (11.5%), and Janthinobacterium (6%) were the dominant genera on dentists' cell phones. The oral bacteria identified were Anaerococcus lactolyticus, Gibbsiella dentisursi, Lactobacills leiae, Streptococcus mitis, Streptococcus oligofermentans, and Streptococcus sanguinis. Pathogenic bacteria and opportunistic pathogens such as Carnobacterium funditum, Raoultella planticola, Shigella flexneri, Lactobacillus iners, Staphylococcus aureus, and Staphylococcus epidermidis were also identified.
Bacteria ; Carnobacterium ; Cellular Phone* ; Clone Cells ; Cloning, Organism ; Dentists* ; Fomites ; Hand ; Humans ; Lactobacillus ; Pseudomonadaceae ; Pseudomonas ; Saliva ; Shigella flexneri ; Staphylococcus aureus ; Staphylococcus epidermidis ; Streptococcus ; Streptococcus mitis

BACKGROUND: Right-to-left vascular shunts are associated with brain abscess. CASE REPORT: We present a 47-year-old female with a cryptogenic left thalamic abscess on which Streptococcus mitis grew upon aspiration. Computed tomography of the chest with contrast agent revealed an anomalous connection between the left superior pulmonary and brachiocephalic veins. A right-to-left shunt was confirmed in a transthoracic echocardiogram study in which bubbles were injected into the left arm; this shunt had not previously been noted upon right-arm injection. CONCLUSIONS: We recommend aggressive evaluation for right-to-left shunts in patients who present with cryptogenic brain abscesses. In addition to imaging, this should include a bubble-based study with left-arm saline injection.
Abscess ; Arm ; Brachiocephalic Veins ; Brain Abscess* ; Brain* ; Female ; Humans ; Middle Aged ; Streptococcus mitis ; Thorax