BACKGROUNDThe dilemma of pathogens identification in patients with unidentified clinical symptoms such as fever of unknown origin exists, which not only poses a challenge to both the diagnostic and therapeutic process by itself, but also to expert physicians.

METHODSIn this report, we have attempted to increase the awareness of unidentified pathogens by developing a method to investigate hitherto unidentified infectious pathogens based on unbiased high-throughput sequencing.

RESULTSOur observations show that this method supplements current diagnostic technology that predominantly relies on information derived five cases from the intensive care unit. This methodological approach detects viruses and corrects the incidence of false positive detection rates of pathogens in a much shorter period. Through our method is followed by polymerase chain reaction validation, we could identify infection with Epstein-Barr virus, and in another case, we could identify infection with Streptococcus viridians based on the culture, which was false positive.

CONCLUSIONSThis technology is a promising approach to revolutionize rapid diagnosis of infectious pathogens and to guide therapy that might result in the improvement of personalized medicine.

Female ; Herpesvirus 4, Human ; genetics ; isolation & purification ; High-Throughput Nucleotide Sequencing ; methods ; Humans ; Male ; Viridans Streptococci ; genetics ; isolation & purification

BACKGROUND: In order to determine the clinical usefulness of the MicroScan (Siemens Healthcare Diagnostics, USA) MICroSTREP plus antimicrobial panel (MICroSTREP) for testing antimicrobial susceptibility of beta-hemolytic streptococci (BHS) and viridans group streptococci (VGS), we compared the accuracy of MICroSTREP with that of the CLSI reference method. METHODS: Seventy-five BHS and 59 VGS isolates were tested for antimicrobial susceptibility to ampicillin, penicillin, cefotaxime, meropenem, erythromycin, clindamycin, levofloxacin, and vancomycin by using MICroSTREP and the CLSI agar dilution method. RESULTS: The overall essential agreement with regard to minimum inhibitory concentrations (MICs) (within +/-1 double dilution) between MICroSTREP and the CLSI reference method was 98.2%, and categorical agreement (CA) was 96.9%. For the BHS isolates, the CA for erythromycin was 96.0%, whereas that for cefotaxime, meropenem, levofloxacin, and vancomycin (for ampicillin, penicillin, and clindamycin; 98.7%) was 100%. For the VGS isolates, the CA for penicillin was 84.7% and that for erythromycin, clindamycin, and vancomycin (for meropenem, 86.5%; for ampicillin, 88.1%; and for cefotaxime and levofloxacin, 96.6%) was 100%. All categorical errors of penicillin and ampicillin in the VGS isolates were minor. CONCLUSIONS: The accuracy of MICroSTREP is comparable to that of the CLSI reference method, suggesting that this panel can be effective for testing antimicrobial susceptibility of BHS and VGS.
Anti-Bacterial Agents/*pharmacology ; Drug Resistance, Bacterial ; Humans ; Microbial Sensitivity Tests ; Reagent Kits, Diagnostic ; Streptococcal Infections/microbiology ; Streptococcus/*drug effects/isolation & purification ; Viridans Streptococci/*drug effects/isolation & purification

BACKGROUND: Viridans group streptococci (VGS) are both commensal microbes and potential pathogens. Increasing resistance to penicillin in VGS is an ongoing issue in the clinical environment. We investigated the difference in susceptibility and resistance to penicillin among various VGS species. METHODS: In total 1,448 VGS isolated from various clinical specimens were analyzed over a two-yr period. Identification and antimicrobial susceptibility test was performed by the automated VITEK 2 system (bioMerieux, France) or the MicroScan MICroSTREP system (Siemens, Germany). RESULTS: Among the 1,448 isolates, 412 were isolated from blood (28.4%). Streptococcus mitis group was the most frequently isolated (589 isolates, 40.7%), followed by the S. anginosus group (290 isolates, 20.0%), S. sanguinis group (179 isolates, 12.4%) and S. salivarius group (57 isolates, 3.9%). In total, 314 isolates could not be identified up to the species level. The overall non-susceptibility to penicillin was observed to be 40.0% (resistant, 11.2% and intermediately resistant, 28.8%) with uneven distribution among groups; 40.2% in S. sanguinis group (resistant, 5.0% and intermediately resistant, 35.2%), 60.3% in S. mitis group (resistant, 20.9% and intermediately resistant, 39.4%), 78.9% in S. salivarius group (resistant, 8.8% and intermediately resistant, 70.1%), and 6.2% in S. anginosus group (resistant, 1.7% and intermediately resistant, 4.5%). CONCLUSIONS: Antimicrobial resistance patterns towards penicillin show differences among various VGS; this should be considered while devising an effective antimicrobial treatment against VGS.
Anti-Infective Agents/*pharmacology ; Body Fluids/microbiology ; Drug Resistance, Bacterial ; Humans ; Microbial Sensitivity Tests ; Penicillins/pharmacology ; Streptococcal Infections/microbiology/pathology ; Viridans Streptococci/*drug effects/isolation & purification

Right-sided infective endocarditis (RIE) occurs predominantly in intravenous drug users in western countries, and it has a relatively good prognosis. Clinical features and prognosis of RIE occurring in non-drug users are not well known. We investigated the clinical findings of RIE in non-drug users. We retrospectively reviewed 345 cases diagnosed with IE. Cases with RIE or left-sided infective endocarditis (LIE) defined by the vegetation site were included and cases having no vegetation or both-side vegetation were excluded. Clinical findings and in-hospital outcome of RIE were compared to those of LIE. Among the 245 cases, 39 (16%) cases had RIE and 206 (84%) cases had LIE. RIE patients were younger (40+/-19 yr vs 50+/-18 yr, P=0.004), and had a higher incidence of congenital heart disease (CHD) (36% vs 13%, P<0.001) and central venous catheter (CVC) (21% vs 4%, P=0.001) compared to LIE patients. A large vegetation was more common in RIE (33% vs 9%, P<0.001). Staphylococcus aureus was the most common cause of RIE, while Streptococcus viridans were the most common cause of LIE. In-hospital mortality and cardiac surgery were not different between the two groups. CHD and use of CVC were common in non-drug users with RIE. The short-term clinical outcome of RIE is not different from that of LIE.
Adult ; Aged ; Central Venous Catheters/microbiology ; Echocardiography ; Endocarditis, Bacterial/*diagnosis/microbiology/mortality ; Female ; Heart Defects, Congenital/complications/epidemiology ; Hospital Mortality ; Humans ; Incidence ; Male ; Middle Aged ; Prognosis ; Retrospective Studies ; Staphylococcus aureus/isolation & purification ; Viridans Streptococci/isolation & purification ; Young Adult

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