Clinicomicrobiological risk factors for infective endocarditis in viridans group streptococci bacteraemia.

BACKGROUND: When to perform echocardiography to rule out infective endocarditis (IE) in patients with viridans group streptococci (VGS) bloodstream infections (BSIs) is unclear. OBJECTIVES: We aimed to identify independent risk factors for IE in patients with VGS BSI. METHODS: This retrospective study conducted at Seoul National University Hospital from January 2013 to December 2022 involved patients with VGS and nutritionally variant streptococcal BSI, excluding single positive blood cultures and polymicrobial BSI cases. Independent risk factors were identified by multivariate logistic regression and sensitivity analyses according to echocardiography results, VGS species or the inclusion of possible IE cases. RESULTS: Of 845 VGS BSI cases, 349 were analysed and 86 IE cases were identified (24.6%). In the multivariate analysis, heart valve disease [adjusted odds ratio (aOR), 14.14, 95% CI, 6.14-32.58; P < 0.001], persistent bacteraemia (aOR, 5.12, 95% CI, 2.03-12.94; P = 0.001), age (per year, aOR, 0.98; 95% CI, 0.96-1.00; P = 0.015), solid cancer (aOR, 0.26; 95% CI, 0.13-0.53; P < 0.001) and haematologic malignancy (aOR, 0.04; 95% CI, 0.01-0.41; P = 0.006) were independently associated with IE. Sensitivity analyses yielded consistent results; also, infection by a member of the mitis group was independent risk factor for IE (aOR, 6.50; 95% CI, 2.87-14.68; P < 0.001). CONCLUSIONS: Younger age, heart valve disease, persistent bacteraemia, absence of underlying malignancy and BSI by a member of the mitis group were independent risk factors for IE in patients with VGS BSI. Echocardiographic evaluation could be prudently considered based on these clinicomicrobiological risk factors.

Low rates of complications and ß-lactam resistance in viridans group streptococci bloodstream infection among cancer patients receiving chemotherapy.

BACKGROUND: Viridans group streptococci (VGS) bloodstream infection (BSI) frequently occurs in cancer patients receiving chemotherapy, and is associated with infective endocarditis (IE) in up to 20% of cases in the general population. OBJECTIVES: In cancer patients receiving chemotherapy with VGS BSI, we aimed to: (i) determine the incidence of infective complications including IE, (ii) assess the utility of echocardiography in this patient population, (iii) determine the duration and type of antimicrobial therapy received for monomicrobial infections, and (iv) determine the evolution of antimicrobial resistance. METHODS: VGS BSIs (excluding Streptococcus pneumoniae and Streptococcus pseudopneumoniae) in cancer patients receiving chemotherapy were identified from a statewide public pathology database between 2013 and 2022 at our tertiary centre. Medical records were accessed for clinical, microbiological and radiological data. RESULTS: Of 581 patient episodes screened, 183 episodes involving 171 patients met inclusion criteria. Of these, 51% were bone marrow transplantation (BMT) patients, 40% were non-BMT haematology patients, and 8% were solid organ malignancy patients. The median age was 55 years, and 96% were neutropenic at the time of blood culture collection. A transthoracic echocardiogram was performed for 71% of episodes, and one patient met modified Duke's criteria for definite IE, although this diagnosis was not suspected on clinical grounds. Other complications were uncommon. Benzylpenicillin resistance was rare (2.9%) and did not change over time. Most episodes (75%) were treated with piperacillin/tazobactam. For monomicrobial BSIs, the median antibiotic duration was 5 days (IQR 2-7) post-neutropenia resolution. CONCLUSIONS: Infective complications and antimicrobial resistance are rare in cancer patients with VGS BSI. This may provide a safe opportunity to limit both investigations (e.g. echocardiogram) and prolonged exposure to broad-spectrum antimicrobials.

Diagnosing odontogenic sinusitis of endodontic origin: A multidisciplinary literature review.

PURPOSE: Endodontic disease is one of the most common causes of bacterial odontogenic sinusitis (ODS). Diagnosing ODS of endodontic origin involves otolaryngologists confirming sinusitis, and dental specialists confirming endodontic sources. The purpose of this study was to conduct a multidisciplinary literature review to highlight clinical and microbiological features of ODS, and the most optimal diagnostic modalities to confirm endodontic disease. METHODS: An extensive review of both medical and dental literature was performed by rhinologists, endodontists, and an infectious disease specialist. Frequencies of various clinical and microbiological features from ODS studies were collected, and averages were calculated. Different endodontic testing and imaging modalities were also evaluated on their abilities to confirm endodontic disease. RESULTS: ODS patients most often present with unilateral sinonasal symptoms for over 3 months, purulence on nasal endoscopy, and overt dental pathology on computed tomography (CT). Subjective foul smell, and maxillary sinus cultures demonstrating anaerobes and α-streptococci (viridans group) may be more specific to ODS. For endodontic evaluations, cold pulp testing and cone-beam CT imaging are most optimal for confirming pulpal and periapical disease. CONCLUSION: Diagnosing ODS requires collaboration between otolaryngologists and dental specialists. Clinicians should suspect ODS when patients present with unilateral sinonasal symptoms, especially foul smell. Patients will generally have purulent drainage on nasal endoscopy, and both sinus opacification and overt dental pathology on CT. However, some patients will have subtle or absent dental pathology on CT. For suspected endodontic disease, endodontists should be consulted for at least cold pulp testing, and ideally cone-beam CT.

The epidemiological and clinical features of odontogenic infective endocarditis.

Antibiotic prophylaxis (AP) of infective endocarditis (IE) in dental practice is a controversial topic. We evaluated the characteristics of the odontogenic IE and assessed the practice and sources of information pertaining to the topic utilized by the Croatian dentists. We conducted a retrospective review of consecutive medical charts of adult patients with IE, admitted to the University Hospital for Infectious Diseases in Zagreb, Croatia, between January 2007 and December 2017. In addition, a cross-sectional, self-reporting questionnaire survey was conducted with participation of 348 Croatian dentists. Of the 811 admissions for suspected IE (40.3% of all Croatian and 92.1% of all Zagreb hospitals), 386 patients were confirmed as definite IE: 68 with odontogenic IE and 318 with IE of other origin. Their first hospital admissions were analyzed. Definite odontogenic IE was defined as a positive echocardiographic result in conjunction with two separate positive blood cultures showing exclusive oral cavity pathogen or Streptococcus viridans associated with current or recent (< 1 month) dental, periodontal, or oral cavity infection. The annual number of new odontogenic IE patients appeared constant over time. In 91.2% of the cases, odontogenic IE was not preceded by a dental procedure; poor oral health was found in 51.5% of patients, and 47.1% had no cardiac condition that increases the IE risk. In-hospital mortality was 5.1% with conservative treatment and 4.5% with cardiac surgery and was much lower for odontogenic IE than in non-odontogenic IE (14.6% and 34.4%, respectively). An increasing number of admissions for non-odontogenic IE were observed in parallel with an increasing number of staphylococcal IE. Surveyed dentists (500 invited, 69.6% responded) were aware of the AP recommendations, but were largely reluctant to treat patients at risk. In people with poor oral health, AP should be considered regardless of cardiac risk factors. Improvement of oral health should be the cornerstone of odontogenic IE prevention.

Epidemiological and clinical characteristics of Streptococcus tigurinus endocarditis.

BACKGROUND: Streptococcus tigurinus was recently described as a new streptococcal species within the viridans group streptococci (VGS). The objectives of the present work were to analyse the clinical and microbiological characteristics of S. tigurinus isolated from patients with bacteraemias, to determine the prevalence of S. tigurinus among VGS endocarditis in Spain, and to compare the clinical characteristics and outcomes of endocarditis caused by S. tigurinus and other VGS. METHODS: Retrospective nationwide study, performed between 2008 and 2016 in 9 Spanish hospitals from 7 different provinces comprising 237 cases of infective endocarditis. Streptococcal isolates were identified by sequencing fragments of their 16S rRNA, sodA and groEL genes. Clinical data of patients with streptococcal endocarditis were prospectively collected according to a pre-established protocol. RESULTS: Patients with endocarditis represented 7/9 (77.8%) and 26/86 (30.2%) of the bacteraemias caused by S. tigurinus and other VGS, respectively (p < 0.001), in two of the hospital participants. Among patients with streptococcal endocarditis, 12 different Streptococcus species were recognized being S. oralis, S. tigurinus and S. mitis the three more common. No relevant statistical differences were observed in the clinical characteristics and outcomes of endocarditis caused by the different VGS species. CONCLUSIONS: In this multicenter study performed in Spain, S. tigurinus showed a higher predilection for the endocardial endothelium as compared to other VGS. However, clinical characteristics and outcomes of endocarditis caused by S. tigurinus did not significantly differ from endocarditis caused by other oral streptococci.

Cumulative incidence and mortality of infective endocarditis in Siriraj hospital-Thailand: a 10-year retrospective study.

BACKGROUND: To investigate the cumulative incidence of and factors associated with mortality among patients with infective endocarditis (IE) at Thailand's largest national tertiary referral center. METHODS: Medical charts of adult patients diagnosed with IE by Duke criteria at Siriraj Hospital during January 2005 to May 2015 were retrospectively reviewed. RESULTS: Of 380 patients, 66.3% had definite IE, and 81.3% had native valve IE (NVE). Cumulative IE incidence was 5.67/1000 admissions. The most common pathogens were viridans group streptococci (VGS) (39.7%), methicillin-sensitive Staphylococcus aureus (MSSA) (13.1%), and beta-hemolytic streptococci (11.5%) in NVE; and, MSSA (20.3%), VGS (20.3%), and Enterococcus spp. (16.9%) in prosthetic valve (PVE) or device-related IE (DRIE). Overall in-hospital mortality was 18.4%. Mortality was significantly higher in PVE/DRIE than in NVE (26.8% vs. 16.5%, p = 0.047). End-stage renal disease (ESRD) (aOR: 9.43, 95% CI: 2.36-37.70), diabetes mellitus (DM) (aOR: 2.81, 95% CI: 1.06-7.49), neurological complication (aOR: 14.16, 95% CI: 5.11-39.22), congestive heart failure (aOR: 4.32, 95% CI: 1.91-9.75), hospital-acquired infection (aOR: 3.78, 95% CI: 1.66-8.57), renal complication (aOR: 3.12, 95%CI: 1.32-7.37), and other complication during admission (aOR: 3.28, 95% CI: 1.41-7.61) were independently associated with mortality. CONCLUSIONS: The incidence of IE, and the mortality rate among those diagnosed with IE are both increasing in Thailand - particularly among those with PVE or DRIE. End-stage renal disease, diabetes mellitus, and development of IE-related complications during admission were found to be independent predictors of mortality.

Associations between echocardiographic manifestations and bacterial species in patients with infective endocarditis: a cohort study.

BACKGROUND: The diagnosis of infective endocarditis (IE) is based on microbiological analyses and diagnostic imaging of cardiac manifestations. Echocardiography (ECHO) is preferred for visualization of IE-induced cardiac manifestations. We investigated associations between bacterial infections and IE manifestations diagnosed by ECHO. METHODS: In this cohort study, data from patients aged 18 years or above, with definite IE admitted at the Karolinska University Hospital between 2008 and 2017 were obtained from Swedish National Registry of Endocarditis. Bacteria registered as pathogen were primarily selected from positive blood culture and for patients with negative blood culture, bacteria found in culture or PCR from postoperative material was registered as pathogen. Patients with negative results from culture or PCR, and patients who did not undergo ECHO during hospital stay, were excluded. IE manifestations diagnosed by ECHO were obtained from the registry. Chi-squared test and two-sided Fisher's exact test was used for comparisons between categorical variables, and student's t test was used for continuous numerical variables. Multivariable analyses were performed using logistic regression. Secular trend analyses were performed using linear regression. Associations and the strength between the variables were estimated using odds ratios (ORs) with 95% confidence intervals (CIs). P < 0.05 was considered significant. RESULTS: The most common bacteria were Staphylococcus aureus (n = 239, 49%) and viridans group streptococci (n = 102, 21%). The most common manifestations were vegetation in the mitral (n = 195, 40%), aortic (n = 190, 39%), and tricuspid valves (n = 108, 22%). Associations were seen between aortic valve vegetations and Enterococcus faecalis among patients with native aortic valves, between mitral valve vegetations and streptococci of group B or viridans group, between tricuspid valve vegetations and S. aureus among patients with intravenous drug abuse, and between perivalvular abscesses as well as cardiovascular implantable electronic device (CIED)-associated IE and coagulase negative staphylococci (all P < 0.05). CONCLUSIONS: Associations were found between certain bacterial species and specific ECHO manifestations. Our study contributes to a better understanding of IE manifestations and their underlying bacterial etiology, which pathogens can cause severe infections and might require close follow-up and surgical treatment.

Clinical Significance of Isolates Known to Be Blood Culture Contaminants in Pediatric Patients.

Background and objectives: The objective of this study was to investigate the clinical significance of isolates from blood stream infection known to be blood culture contaminants in pediatric patients. Materials and Methods: Microbiological reports and medical records of all blood culture tests issued from 2002 to 2012 (n = 76,331) were retrospectively reviewed. Evaluation for potential contaminants were done by reviewing medical records of patients with the following isolates: coagulase-negative Staphylococcus, viridans group Streptococcus, Bacillus, Corynebacterium, Micrococcus, Aerococcus, and Proprionibacterium species. Repeated cultures with same isolates were considered as a single case. Cases were evaluated for their status as a pathogen. Results: Coagulase-negative Staphylococcus had clinical significance in 23.8% of all cases. Its rate of being a true pathogen was particularly high in patients with malignancy (43.7%). Viridans group Streptococcus showed clinical significance in 46.2% of all cases. Its rate of being a true pathogen was similar regardless of the underlying morbidity of the patient. The rate of being a true pathogens for remaining isolates was 27.7% for Bacillus and 19.0% for Corynebacterium species. Conclusions: Coagulase-negative Staphylococcus and viridans group Streptococcus isolates showed high probability of being true pathogens in the pediatric population, especially in patients with underlying malignancy.

[Identification and antibiotic susceptibility of viridans group streptococci isolates recovered from patients hospitalized at a teaching hospital in Buenos Aires City]. / Identificación y sensibilidad a los antimicrobianos de aislados de estreptococos del grupo viridans provenientes de pacientes internados en un hospital universitario de la ciudad de Buenos Aires.

Members of the viridans group streptococci (VGS) are the cause of local and invasive infections. Due to the severity of these infections and taking into account that reports regarding epidemiological aspects are scarce, the aims of this work were the identification and the study of the antibiotic susceptibility profiles of the isolates recovered from patients that were hospitalized in order to find out about the resistance level and the epidemiology of infections in which VGS are involved. A hundred and thirty two isolates identified as VGS were isolated at Hospital de Clínicas «José de San Martín¼ during the period 2011-2015. The identification was performed by biochemical test and mass spectrometry by Matrix Assisted Laser Desorption Ionization -Time of Flight Mass Spectrometry. Streptococcus anginosus group was prevalent (42%) followed by Streptococcus mitis group (33%). In the latter, isolates of Streptococcus pneumoniae were excluded. All the VGS isolates were susceptible to ertapenem, meropenem, linezolid and vancomycin; 25.8% were resistant (I+R) to penicillin, being prevalent in the S. mitis group. Regarding ceftriaxone and cefepime 96.9% of the isolates were susceptible. Only two isolates were resistant to levofloxacin, 27.2% to tetracycline and it was not found high level resistance to gentamycin (MIC range 0.5-32µg/ml). Resistance to erythromycin was 17.4% with no significant difference between M and MLS phenotypes. The most active antibiotics were in addition to ceftriaxone and cefepime, vancomycin, ertapenem, meropenem and linezolid. These results highlight the importance of the continuous surveillance of the infections caused by VGS in order to predict a correct antibiotic therapy.

Activity of dalbavancin and comparator agents against Gram-positive cocci from clinical infections in the USA and Europe 2015-16.

Background: Many infections due to Gram-positive cocci (GPC; staphylococci, streptococci and enterococci) regularly involve prolonged systemic antibiotic use. Dalbavancin has demonstrated activity against GPC isolates and has been approved for the treatment of acute bacterial skin and skin structure infections (ABSSSIs) in adults. Objectives: To evaluate the activity of dalbavancin against GPC isolated from a variety of infection types in the USA and Europe. Methods: A total of 14 319 Staphylococcus aureus, 1992 CoNS, 3269 ß-haemolytic streptococci (BHS), 2071 Enterococcus faecalis, 936 Enterococcus faecium, 71 Enterococcus gallinarum/casseliflavus and other Enterococcus spp., 3487 Streptococcus pneumoniae and 1063 viridans group streptococci (VGS) causing clinical infections were consecutively collected (2015-16) and tested for susceptibility by broth microdilution methods. Results: All S. aureus (36.4% MRSA) isolates were susceptible to dalbavancin, teicoplanin and vancomycin, while daptomycin and linezolid showed susceptibility rates of >99.9% (according to CLSI criteria). Dalbavancin MIC results were at least 16-fold lower than these comparators against all S. aureus. Dalbavancin was the most potent agent against CoNS [62.2%/59.6% methicillin-resistant (CLSI/EUCAST)], followed by daptomycin, linezolid and vancomycin. All vancomycin-susceptible E. faecalis isolates were inhibited by dalbavancin at ≤0.25 mg/L (FDA susceptible breakpoint). Dalbavancin was very active against BHS (MIC90 0.03 mg/L) and the most active agent against S. pneumoniae and VGS (highest MIC 0.25 mg/L). Ceftriaxone, daptomycin, levofloxacin and vancomycin were also active (93.5%-100.0% susceptible) against VGS, whereas clindamycin, erythromycin, penicillin and tetracycline had lower activity. Conclusions: Dalbavancin appears to be a viable candidate for treating serious infections caused by GPC.

Septic Carotid Endarterectomy Patch as a Result of Preoperative Tooth Extraction.

Infected carotid patches are rare. We present a gentleman who had an elective carotid endarterectomy with Dacron patch closure for symptomatic carotid stenosis under regional anesthesia, and he presented 1 month later with a discharging sinus at the lower aspect of the neck wound. Computed tomography scan showed a rim-enhancing collection next to the carotid bifurcation. He subsequently underwent patch excision and repair with autologous saphenous vein graft, with good recovery. Of significance was that he had a dental extraction for a loose tooth 1 day before the index operation as advised by the anesthetist. Streptococcus viridans species, which are part of the normal flora of oral cavity, were isolated from the tissue culture. This is the first case in the world's literature of a patient who had S. viridans carotid patch infection that may be related to his preoperative tooth extraction.

Viridans streptococcus peritonitis in peritoneal dialysis: clinical characteristics and comparison with concurrent polymicrobial infection.

BACKGROUND: The clinical course of Viridans streptococci (VS) peritonitis in patients undergoing peritoneal dialysis (PD) is rarely reported. This study examined the association of clinical factors with VS peritonitis. METHODS: We retrospectively reviewed clinical data from patients with VS peritonitis from March 1990 to February 2016 in a PD center in Taiwan and evaluated clinical profiles and treatment outcomes. RESULTS: A total of 109 episodes of VS peritonitis in 71 patients identified. Among these patients, 57 had mono-VS peritonitis and 14 had concurrent polymicrobial infections. The median time interval from PD initiation to the first VS peritonitis episode was 18 months (range, 0.6-144 months). Among clinical outcomes, most VS peritonitis episodes were completely cured regardless of a history of peritonitis. All episodes with catheter removal occurred in those without a history of recent antibiotic use. CONCLUSION: VS peritonitis in patients undergoing PD typically has favorable treatment outcomes. Antibiotic therapy should be started promptly.

Insight into the Diversity of Penicillin-Binding Protein 2x Alleles and Mutations in Viridans Streptococci.

The identification of commensal streptococci species is an everlasting problem due to their ability to genetically transform. A new challenge in this respect is the recent description of Streptococcus pseudopneumoniae as a new species, which was distinguished from closely related pathogenic S. pneumoniae and commensal S. mitis by a variety of physiological and molecular biological tests. Forty-one atypical S. pneumoniae isolates have been collected at the German National Reference Center for Streptococci (GNRCS). Multilocus sequence typing (MLST) confirmed 35 isolates as the species S. pseudopneumoniae A comparison with the pbp2x sequences from 120 commensal streptococci isolated from different continents revealed that pbp2x is distinct among penicillin-susceptible S. pseudopneumoniae isolates. Four penicillin-binding protein x (PBPx) alleles of penicillin-sensitive S. mitis account for most of the diverse sequence blocks in resistant S. pseudopneumoniae, S. pneumoniae, and S. mitis, and S. infantis and S. oralis sequences were found in S. pneumoniae from Japan. PBP2x genes of the family of mosaic genes related to pbp2x in the S. pneumoniae clone Spain23F-1 were observed in S. oralis and S. infantis as well, confirming its global distribution. Thirty-eight sites were altered within the PBP2x transpeptidase domains of penicillin-resistant strains, excluding another 37 sites present in the reference genes of sensitive strains. Specific mutational patterns were detected depending on the parental sequence blocks, in agreement with distinct mutational pathways during the development of beta-lactam resistance. The majority of the mutations clustered around the active site, whereas others are likely to affect stability or interactions with the C-terminal domain or partner proteins.

Antibiotic prophylaxis with teicoplanin on alternate days reduces rate of viridans sepsis and febrile neutropenia in pediatric patients with acute myeloid leukemia.

Intensive chemotherapy directed against acute myeloid leukemia of childhood is followed by profound neutropenia and high risk for bacterial and fungal infections, including viridans group streptococci as a common cause for gram-positive septicemia. Few retrospective studies have shown the efficacy of various antibiotic prophylactic regimens in children. We retrospectively studied 50 pediatric patients treated on the AML-BFM 2004 protocol between 2005 and 2015 at St. Anna Children's Hospital and assessed the effect of antibiotic prophylaxis on the frequency of febrile neutropenia and bacterial sepsis. Fifty pediatric patients underwent 199 evaluable chemotherapy cycles. Viridans sepsis occurred after none of 98 cycles with prophylactic administration of teicoplanin/vancomycin in comparison to 12 cases of viridans sepsis among 79 cycles without systemic antibacterial prophylaxis (0 vs. 15 %, p < 0.0001). In addition, there were significantly fewer episodes of febrile neutropenia in the teicoplanin/vancomycin group (44 % vs. no prophylaxis 82 %, p < 0.0001). Severity of infection seemed to be worse when no antibiotic prophylaxis had been administered with a higher rate of intensive care unit treatment (0/98, 0 %, vs. 4/79, 5 %, p = 0.038). So far, no increase of vancomycin-resistant enterococcus isolates in surveillance cultures was noticed. Antibiotic prophylaxis with teicoplanin (or vancomycin) appears safe and feasible and resulted in eradication of viridans sepsis and decreased incidence of febrile neutropenia in pediatric AML patients. The possibility to administer teicoplanin on alternate days on an outpatient basis or at home could contribute to patient's quality of life and decrease health care costs.

The Microbiome of the Lower Respiratory Tract in Premature Infants with and without Severe Bronchopulmonary Dysplasia.

Aim We determined whether the bacteria in the lower respiratory tract (LRT) in extremely premature infants with severe bronchopulmonary dysplasia (BPD) are different from those with nonsevere BPD. Study Design We conducted a retrospective study of extremely premature infants who were admitted to the neonatal intensive care unit of Fukushima Medical University Hospital, Japan between April 2005 and March 2014. We screened for the bacterial colonization of the LRT using tracheobronchial aspirate fluid. Results A total of 169 extremely premature infants were included. Overall, 102 did not experience severe BPD, whereas the remaining 67 experienced severe BPD. Corynebacterium species (Cs) were more frequently detected in the severe BPD than nonsevere BPD infants (p = 0.03). There were significant differences between infants with and without severe BPD in the duration of endotracheal ventilation (p = 0.00, odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01-1.06), the duration of supplemental oxygen (p = 0.00, OR, 1.02; 95% CI, 1.01-1.03) before 36 weeks of postmenstrual age, and the frequency of sepsis after 7 postnatal days (p = 0.01, OR, 1.73; 95% CI, 1.18-2.54). Conclusion Cs are more likely to be present in the severe BPD infants with longer duration of endotracheal ventilation.

[Comparison of MALDI-TOF and 16S rRNA methods in identification of viridans group streptococci]. / Viridans grup streptokok tanimlamasinda MALDI-TOF ve 16S rRNA yöntemlerinin karsilastirilmasi.

Accurate identification of viridans group streptococci (VGS) frequently encountered as a causative agent of infective endocarditis is always a challenge for the clinical microbiology laboratory. Clinical microbiology laboratories generally use semi automatic/full automatic systems, molecular methods and also conventional methods for the identification of these bacteria. There are recent published studies that have used MALDI-TOF (Matrix Assisted Laser Ionization Mass Spectrometry-Time of Flight) systems in the identification of VGS. The aim of the study was to compare the performance of the conventional methods, semi automatic and MALDI-TOF MS system used in identification of VGS in oral microbiota of persons under the risk of infective endocarditis, with the gold standard method 16S rRNA sequence analysis and to create a diagnosis algorithm for the identification of VGS in clinical microbiology laboratories according to the obtained data.The study was conducted with 51 VGS strains isolated from oral microbiota of the patients with rheumatologic cardiac, valve and/or prosthetic valve diseases, under the risk of development of infective endocarditis, who have admitted to Ankara Numune Training and Research Hospital, Department of Cardiology, between February-June 2015. Standard microbiology procedures, optochin susceptibility and bile solubility tests were done for the isolation of bacteria. Bacteria were also identified with APISTREP (bioMérieux, France) and MALDI-TOF MS Bruker Microflex (Bruker Biotyper; Bruker Daltonics, Bremen, Germany) methods. BSF-8 (5´-AGAGTTTGATCCTGGCTCAG-3´) and BSR-534(5´-ATTACCGCGGCTGCTGGC-3´) primers were used in the 16S rRNA sequence analysis of bacteria. ABI PRISM 3100 Avan t Genetic Analyzer (Applied Biossytems, Foster City, CA, USA) were used for the sequence analysis. Electropherograms were analyzed in SeqScape Software (Applied Biosystems, Foster City, CA, USA) and compared with the reference sequences in GenBank with BLASTN (NCBI). According to the result of optochin and bile solubility tests, with API STREP system, 16 (31,37%) of the isolates were identified as Mitis group, 15 (29.41%) as Anginosus group, 9 (17.5%) as Salivarius group, 7 (13,73%) as Sanguinis group and 4 (7.84%) as Bovis group among optochin and bile resistant alpha hemolytic streptococci. Moreover, of the same isolates 20 (39.22%) were identified as Mitis group, 14 (27.45%) as Anginosus group, 13 (25.49%) as Salivarius group and 4 (7.84%) as Sanguinis group with MALDI-TOF system. In the identification with 16S rRNA, 25 (49.02%) of the isolates were identified as Mitis group, 13 (25.49%) as Anginosus group, 12 (23.53%) as Salivarius group and 1 (1.96%) as Sanguinis group. According to the results, it was determined that 33 (64.70%) of the isolates identified in MALDI-TOF MS system and 31 (60.78%) of the isolates identified in API STREP system were compatible with 16S rRNA sequence analysis method. For Mitis group, API STREP test sensitivity was 48.00% and specificity was 84.62% and MALDI-TOF system sensitivity was 80.00% and specificity was 100%. As VGS identification is a complicated process, we believe a single method will be insufficient for the identification of these isolates in clinical microbiology laboratories. We suggest that MALDI-TOF system can be used for VGS diagnosis, however, optochin test and/or molecular methods should also be included in the diagnosis algorithm when necessary.

Bloodstream infections in patients with chronic lymphocytic leukemia: a longitudinal single-center study.

Infectious complications in chronic lymphocytic leukemia (CLL) represent a major cause of morbidity and mortality. The aim of the study was to investigate temporal trends in bloodstream infections (BSIs) among patients with CLL. Individuals with blood cultures were linked to Swedish Cancer Registry and divided into three time periods (1988-1993, 1994-1999, and 2000-2006) according to year of CLL diagnosis. CLL patients (n = 275) with 1092 blood culture episodes were identified and linked to the nationwide Cause of Death Registry and Swedish Patient Registry (to retrieve information on splenectomies). The most common causes of BSI among CLL patients were Escherichia coli (11/43, 15/78, and 9/33), Streptococcus pneumoniae (7/43, 13/78, and 6/33), Pseudomonas aeruginosa (2/43, 8/78, and 3/33), Staphylococcus aureus (1/43, 6/78, and 6/33), and Viridans streptococci (5/43, 6/78, and 2/33). Coagulase-negative staphylococci was the most frequent microorganism found in blood cultures (22/70, 23/106, and 5/41, respectively) but is a frequent contaminant. Based on the largest study to date on BSI in CLL patients, we found a stable proportion of Gram-positive to Gram-negative bacteria and no temporal change of distribution was observed for BSIs 1988-2006.

Breakthrough viridans streptococcal bacteremia in allogeneic hematopoietic stem cell transplant recipients receiving levofloxacin prophylaxis in a Japanese hospital.

BACKGROUND: Breakthrough viridans streptococcal bacteremia (VSB) in patients with hematological malignancy receiving levofloxacin prophylaxis is a major blood stream infection (BSI) occurring during febrile neutropenia. However, clinical data focused on VSB in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients are lacking. METHODS: The medical records of allo-HSCT recipients who received oral levofloxacin prophylaxis between January 2011 and August 2013 at Toranomon Hospital were reviewed to evaluate breakthrough VSB. Stored viridans streptococcal (VGS) species were identified by using sodA gene sequencing, and were assessed for drug susceptibility. RESULTS: Among the 184 allo-HSCT recipients on levofloxacin prophylaxis, 28 (15.2 %) experienced breakthrough VSB. All of the 28 recipients with VSB were treated with a cefepime-based or piperacillin/tazobactam-based regimen. The susceptibility rates of the VGS strains for levofloxacin, cefepime, piperacillin/tazobactam, meropenem, and vancomycin were 0 %, 95 %, 100 %, 100 %, and 100 %, respectively. Both the MIC50 (minimum inhibitory concentration) and the MIC90 of ceftazidim (0.5 µg/mL and 2 µg/mL, respectively) were higher than the MIC90 of all the other anti-pseudomonal beta-lactams (APBLs). Only 1 VGS strain had a penicillin MIC ≥ 2 µg/mL by the Etest (3.6 %). There were no cases with acute respiratory distress syndrome (ARDS) that was associated with VSB, although the rate of viridans group streptococcal shock syndrome was high (26 %). The crude 30-day mortality rate in the VSB group (10.7 %) did not differ significantly from that in the BSI without VSB group (9.3 %) or non-BSI group (7.0 %) (P = 0.77). Also, VSB was not a risk factor for all-cause mortality up to 60 days following allo-HSCT (P = 0.43). CONCLUSIONS: APBL with increased anti-VGS activity (APBL-VA) monotherapy would typically be optimal for treating the VGS strains in this setting. Indication of adding an empiric anti-gram-positive agent to APBL-VA for treating VSB should depend on local factors, such as the susceptibility results. In addition, breakthrough VSB is probably not a major cause of death in allo-HSCT settings, where beta-lactam non-susceptible VGS and the ARDS are rare.

Predictors of prolonged stay in patients with community-acquired pneumonia and complicated parapneumonic effusion.

BACKGROUND AND OBJECTIVE: Development of CPE in CAP is associated with prolonged hospital stay and it may increase the morbidity and mortality. We aimed to identify microbiological and clinical factors that predicate a prolonged hospital admission in patients treated with a tube thoracostomy to control CPE. METHODS: This retrospective cohort included patients with CPE requiring chest tube drainage in a tertiary referral Korean hospital from 1 January 2004 to 30 July 2012. After dichotomous grouping according to the mean duration of hospital stay, clinical, laboratory and microbiological parameters were compared. RESULTS: The final analysis included 158 patients with CPE. The majority were male (130, 85.0%), and the mean age was 62.8 years. The mean duration of hospital stay was 17.7 (±10.2) days. The mean duration of chest tube drainage was 9.6 (±6.7) days. Streptococcus viridans (48.4%) was the most common pathogen. Intrapleural fibrinolysis was performed in 85 (53.8%); additional tube insertion was needed in 40 (25.3%) patients. In the multivariate analysis after adjusting for covariates, a prolonged hospital stay was associated with fever (aOR: 3.42, P = 0.02), lower PaO2 (aOR: 4.89, P = 0.007) and haemoglobin (aOR: 4.90, P = 0.003) levels, and an increased blood neutrophil fraction (aOR: 3.83, P = 0.01) on admission as well as the identification of microbes in CPE (aOR: 4.14, P = 0.03), and ineffective pleural drainage (aOR: 3.28, P = 0.03). CONCLUSIONS: This study suggests that physicians should note the clinical symptoms and laboratory findings of severe infection and effectiveness of pleural drainage to predicate which patients with a CAP needing thoracostomy for CPE will have a prolonged hospital stay.