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

OBJECTIVE: To explore whether streptococcal infection may aggravate renal damage in children with Henoch-Schönlein purpura nephritis and its possible mechanism. METHODS: In the study, 485 children diagnosed with Henoch-Schönlein purpura nephritis from July 2015 to December 2019 were selected to analyze their clinical data retrospectively. According to the diagnosis of discharge, whether it was combined with streptococcal infection, the children were divided into two groups. The experimental group contained 91 children with Henoch-Schönlein purpura nephritis combined with streptococcal infection, and there were 394 children who were not infected with Streptococcus in the control group. Suitable test items were preliminarily selected through artificial neural network, and then data analysis was performed through SPSS 23.0. RESULTS: The children with Henoch-Schönlein purpura nephritis infected with streptococcus had statistically significant differences compared with the uninfected children in the test items of urine protein, liver and kidney function, immunoglobulin and complement. Anti-streptolysin O had mild correlation with IgG (Spearman r=-0.328), fibrin degradation products (Spearman r=-0.207), total protein (Spearman r=-0.202) and globulin (Spearman r=-0.223). Compared with the children who were not infected with streptococcus, the differences of the average levels of age (P=0.001), IgG (P < 0.001), fibrin degradation products (P=0.019), total protein (P < 0.001), globulin (P < 0.001), IgA (P < 0.001), IgM (P=0.003), complement 3 (P=0.016), complement 4 (P=0.002), albumin/globulin ratio (P=0.007), alkaline phosphatase (P=0.036), and estimated glomerular filtration rate (P=0.039) in the infected children were statistically significant. In order to explore the risk factors of kidney damage in the children with Henoch-Schönlein purpura nephritis, Logistic regression was performed using anti-streptolysin O, age, immunoglobulin and complement as independent variables, urine protein detection parameters, liver and kidney functions as dependent variables. Age ≤10 years old and hypocomplementemia might be risk factors for aggravating renal damage in the children with Henoch-Schönlein purpura nephritis. CONCLUSION Streptococcal infections may aggravate renal damage in children with Henoch-Schönlein purpura nephritis, in which hypocomplementemia, inflammation, fibrinolysis and disorders of coagulation perhaps play an important role. Children with streptococcal infection should be treated with anti-infective treatment in time and necessarily, and followed up after discharge regularly.
Humans ; IgA Vasculitis/complications* ; Streptococcal Infections/complications* ; Child ; Male ; Female ; Nephritis/microbiology* ; Retrospective Studies ; Child, Preschool ; Kidney/pathology* ; Adolescent

Group B streptococcus (GBS) is one of the severe pathogenic bacteria during the perinatal period, both on pregnant women and newborns. GBS infection may lead to pneumonia, septicemia, meningitis or other severe disease, even death in neonates. Although only 1%-2% infections will develop into GBS disease among the neonates, the etiological mechanism of which is worth researching. This review summarizes the possible factors related to GBS infection or occurrence of the disease, including the risk in gestation period (for example, colonization of GBS on vagina of pregnant women, preterm birth or premature rupture of fetal membranes and so on), related pathogens (bacteria strains, loads or virulence), immune level (inflammatory factor or neutralizing anticytokine auto-Abs), gene defect or primary immunodeficiencies of the hosts.
Female ; Humans ; Infant, Newborn ; Infectious Disease Transmission, Vertical ; Pregnancy ; Pregnancy Complications, Infectious/urine* ; Premature Birth ; Streptococcal Infections/urine* ; Streptococcus agalactiae/isolation & purification* ; Vagina/microbiology*

Objective: To analyze the characteristics of super-antigen (SAg) of group A Streptococcus pyogenes (GAS), isolated from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. Methods: Throat swab specimens from patients with scarlet fever or pharyngeal infections were collected and tested for GAS. Eleven currently known SAg genes including SpeA, speC, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa were tested by real-time PCR while M protein genes (emm genes) were amplified and sequenced by PCR. Results: A total of 377 GAS were isolated from 6 801 throat swab specimens, with the positive rate as 5.5%. There were obvious changes noticed among speC, speG, speH and speK in three years. A total of 45 SAg genes profiles were observed, according to the SAgs inclusion. There were significant differences appeared in the frequencies among two of the highest SAg genes profiles between emm1 and emm12 strains (χ(2)=38.196, P<0.001; χ(2)=72.310, P<0.001). There also appeared significant differences in the frequencies of speA, speH, speI and speJ between emm1 and emm12 strains (χ(2)=146.154, P<0.001; χ(2)=52.31, P<0.001; χ(2)=58.43, P<0.001; χ(2)=144.70, P<0.001). Conclusions: Obvious changes were noticed among SAg genes including speC, speG, speH and speK from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. SAg genes including speA, speH, speI and speJ appeared to be associated with the emm 1 and emm 12 strains. More kinds of SAg genes profiles were isolated form GAS but with no significant differences seen in the main SAg genes profiles, during the epidemic period.
Antigens, Bacterial/genetics* ; Bacterial Outer Membrane Proteins ; Bacterial Proteins ; Beijing/epidemiology* ; China/epidemiology* ; Exotoxins ; Female ; Humans ; Membrane Proteins ; Pharyngitis/microbiology* ; Pharynx/microbiology* ; Pregnancy ; Pregnancy Complications, Infectious/microbiology* ; Real-Time Polymerase Chain Reaction ; Scarlet Fever/microbiology* ; Streptococcal Infections ; Streptococcus pyogenes/isolation & purification* ; Superantigens/genetics*

Aged, 80 and over ; Endophthalmitis ; ethnology ; microbiology ; Female ; Humans ; Sepsis ; complications ; microbiology ; Streptococcal Infections ; complications ; Streptococcus agalactiae ; pathogenicity

BACKGROUND: Group B streptococcus (GBS) infection is a leading cause of neonatal morbidity and mortality worldwide. Here, we present the analytical and diagnostic usefulness of a new real-time PCR-based assay (Xpert GBS; Cepheid, USA) for rapid and accurate prenatal GBS screening. METHODS: We enrolled 175 pregnant women who were between 35 and 39 weeks of gestation. The analytical performance of the Xpert GBS assay was first tested using a reference GBS strain. Next, to test diagnostic performance, rectovaginal swabs were obtained from pregnant women who visited the hospital for regular antenatal screening after 34 weeks of gestation. The results of the Xpert GBS assay were compared to those of standard culture for the detection of prenatal GBS colonization. RESULTS: When any positive result from Xpert GBS or culture was considered a true positive, the sensitivity of the Xpert GBS assay and culture were 91% (20/22; 95% CI [confidence interval], 72-98) and 68% (15/22; 95% CI, 47-84), respectively. The specificity of both methods was 100% (153/153; 95% CI, 97-100). The sensitivity and specificity of the Xpert GBS assay, using the culture results as a reference, were 86.7% and 95.6%, respectively. In the Xpert GBS assay, the median threshold cycle of vaginally colonized samples was significantly lower than rectally colonized samples (P<0.01). CONCLUSIONS: The Xpert GBS assay is an accurate, rapid, easy-to-use test for the detection of maternal GBS colonization in prenatal screening that might be especially useful in clinical settings where standard culture is not feasible.
DNA, Bacterial/*analysis ; Female ; Gestational Age ; Humans ; Pregnancy ; Pregnancy Complications, Infectious/*diagnosis/microbiology ; Prenatal Diagnosis ; Reagent Kits, Diagnostic ; Real-Time Polymerase Chain Reaction ; Rectum/microbiology ; Sensitivity and Specificity ; Streptococcal Infections/*diagnosis/microbiology ; Streptococcus agalactiae/*genetics/isolation & purification ; Vagina/microbiology

Thrombophlebitis of the portal venous system (PVS) with superimposed bacterial infection (septic pylephlebitis) is an extremely rare complication of Crohn's disease (CD), and therefore diagnosis of septic pylephlebitis is difficult without high clinical suspicion. A 16-year old male patient who was diagnosed with CD 3 months earlier was admitted with recurrent fever and abdominal pain. CD activity had been well controlled with conventional medical treatment during a follow-up period. Abdominal contrast-enhanced computed tomography showed massive thrombosis in the PVS without evidence of intra-abdominal infection, and blood cultures were positive for Streptococcus viridians. There was no evidence of deep vein thrombosis or pulmonary thromboembolism, and all laboratory tests for thrombophilia were normal. Based on these findings, the patient was diagnosed with septic pylephlebitis complicated with CD, and was successfully treated with intravenous antibiotic therapy combined with anticoagulation. This case suggests that early comprehensive evaluation is crucial for immediate diagnosis and proper treatment of septic pylephlebitis in patients with CD who present with fever and abdominal pain of unknown origin, even with stable disease activity and absence of other intra-abdominal infections.
Adolescent ; Anti-Bacterial Agents/therapeutic use ; Anticoagulants/therapeutic use ; Colonoscopy ; Crohn Disease/complications/*diagnosis ; Humans ; Male ; Phlebitis/complications/*diagnosis ; Portal Vein/radiography ; Sepsis/*diagnosis/microbiology ; Streptococcal Infections/diagnosis/drug therapy ; Thrombosis/drug therapy/radiography ; Tomography, X-Ray Computed ; Viridans Streptococci/isolation & purification

BACKGROUND: To investigate the risk factors for vaginal infections and antimicrobial susceptibilities of vaginal microorganisms among women who experienced preterm birth (PTB), we compared the prevalence of vaginal microorganisms between women who experienced preterm labor (PTL) without preterm delivery and spontaneous PTB. METHODS: Vaginal swab specimens from 126 pregnant women who experienced PTL were tested for group B streptococcus (GBS), Mycoplasma hominis, Mycoplasma genitalium, Ureaplasma urealyticum, Chlamydia trachomatis, Trichomonas vaginalis, Neisseria gonorrhoeae, Treponema pallidum, herpes simplex virus (HSV) I and II, and bacterial vaginosis. A control group of 91 pregnant women was tested for GBS. Antimicrobial susceptibility tests were performed for GBS, M. hominis, and U. urealyticum. RESULTS: The overall detection rates for each microorganism were: U. urealyticum, 62.7%; M. hominis, 12.7%; GBS, 7.9%; C. trachomatis, 2.4%; and HSV type II, 0.8%. The colonization rate of GBS in control group was 17.6%. The prevalence of GBS, M. hominis, and U. urealyticum in PTL without preterm delivery and spontaneous PTB were 3.8% and 8.7% (relative risk [RR], 2.26), 3.8% and 17.3% (RR, 4.52), and 53.8% and 60.9% (RR, 1.13), respectively, showing no significant difference between the 2 groups. The detection rate of M. hominis by PCR was higher than that by culture method (11.1% vs. 4.0%, P=0.010). The detection rates of U. urealyticum by PCR and culture method were 16.7% and 57.1%, respectively. CONCLUSIONS: There was no significant difference in the prevalence of GBS, M. hominis, and U. urealyticum between the spontaneous PTB and PTL without preterm delivery groups.
Female ; Humans ; Microbial Sensitivity Tests ; Mycoplasma Infections/complications/microbiology ; Mycoplasma hominis/isolation & purification ; Obstetric Labor, Premature/*epidemiology/etiology ; Pregnancy ; Pregnancy Complications, Infectious/epidemiology/microbiology ; Premature Birth/*epidemiology/etiology ; Prevalence ; Risk Factors ; Streptococcal Infections/complications/microbiology ; Streptococcus agalactiae/isolation & purification ; Ureaplasma Infections/complications/microbiology ; Ureaplasma urealyticum/isolation & purification ; Vagina/*microbiology

Necrotizing fasciitis is known to be a highly lethal infection of deep-seated subcutaneous tissue and superficial fascia. Reports of necrotizing fasciitis due to Streptococcus pneumoniae are exceedingly rare. We report a case of necrotizing fasciitis in a 62-yr-old man with liver cirrhosis and diabetes mellitus. He presented with painful swelling of left leg and right hand. On the day of admission, compartment syndrome was aggravated and the patient underwent surgical exploration. Intra-operative findings revealed necrotizing fasciitis and cultures of two blood samples and wound aspirates showed S. pneumoniae. The patient died despite debridement and proper antimicrobial treatment. To the best of our knowledge, this is the first case of fatal necrotizing fasciitis with meningitis reported in Korea. We also review and discuss the literature on pneumococcal necrotizing fasciitis.
Anti-Bacterial Agents/therapeutic use ; Diabetes Mellitus, Type 2/complications/diagnosis ; Fasciitis, Necrotizing/*diagnosis/drug therapy/microbiology/surgery ; Fatal Outcome ; Humans ; Leg/surgery ; Liver Cirrhosis/complications/diagnosis ; Male ; Middle Aged ; Streptococcal Infections/*diagnosis/drug therapy ; Streptococcus pneumoniae/isolation & purification

Streptococcus suis is a swine pathogen that causes meningitis, septicemia, pneumonia, and endocarditis. The first case of human S. suis infection was reported in Denmark in 1968, and since then, this infection with has been reported in many countries, especially in Southeast Asia because of the high density of pigs in this region. We report the case of a patient with septic arthritis and bacteremia caused by S. suis. Cases in which S. suis is isolated from the joint fluid are very rare, and to the best of our knowledge, this is first case report of S. suis infection in Korea. The identity of this organism was confirmed by phenotypic characterization and 16S rRNA sequence analysis. An 81-yr-old Korean woman who presented with fever, arthralgia, and headache was admitted to a secondary referral center in Korea. Culture of aspirated joint fluid and blood samples showed the growth of S. suis biotype II, which was identified by the Vitek2 GPI and API 20 Strep systems (bioMerieux, USA), and this organism was susceptible to penicillin G and vancomycin. The 16S rRNA sequences of the blood culture isolates showed 99% homology with those of S. suis subsp. suis, which are reported in GenBank. The patient's fever subsided, and blood and joint cultures were negative for bacterial growth after antibiotic therapy; however, the swelling and pain in her left knee joint persisted. She plans to undergo total knee replacement.
Aged, 80 and over ; Anti-Bacterial Agents/administration & dosage ; Arthritis, Infectious/complications/*diagnosis/microbiology ; Bacteremia/complications/*diagnosis/microbiology ; Female ; Humans ; Injections, Intravenous ; Microbial Sensitivity Tests ; Phenotype ; RNA, Ribosomal, 16S/chemistry/genetics ; Sequence Analysis, DNA ; Streptococcal Infections/complications/*diagnosis/microbiology ; Streptococcus suis/genetics/*isolation & purification