A case report of streptococcal toxic shock syndrome caused by Streptococcus mitis in a healthy adult.

BACKGROUND: Streptococcal toxic shock syndrome (STSS) is an acute, multisystem and toxin-mediated disease that usually causes shock and multiple organ failure in the early stages of its clinical course. It is associated with a substantial increase in mortality rate. The disease has been associated with invasive group A Streptococcus and is rarely caused by Streptococcus mitis (S. mitis). In healthy adults, S. mitis is closely related to endocarditis but rarely related to STSS. CASE PRESENTATION: We report a case of STSS caused by S. mitis in a healthy 45-year-old woman. She presented with fever 14 h after surgery and with hypotension 24 h later, and she subsequently suffered from septic shock, low albumin, dysfunction of coagulation, acute kidney dysfunction, respiratory alkalosis and metabolic acidosis, acute respiratory distress syndrome and cellulitis of the incision. The diagnosis was obtained through clinical manifestation and blood culture examination. The patient was treated with aggressive fluid resuscitation, adequate antibiotics for a total of 4 weeks, respiratory support, and surgical debridement and drainage of the incision. She was discharged after her vital signs returned to normal and the incision healed on day 40 after surgery. CONCLUSIONS: The diagnosis of STSS is often delayed or missed, which leads to a high mortality rate. It is possible to cure patients if the disease can be identified early and treated with aggressive fluid resuscitation, adequate antibiotics and control of the source of infection. Clinicians should consider the disease in the differential diagnosis of septic shock to prevent death.

Identification of Streptococcus pneumoniae and other Mitis streptococci: importance of molecular methods.

The Mitis group of streptococci includes an important human pathogen, Streptococcus pneumoniae (pneumococcus) and about 20 other related species with much lower pathogenicity. In clinical practice, some representatives of these species, especially Streptococcus pseudopneumoniae and Streptococcus mitis, are sometimes mistaken for S. pneumoniae based on the results of classical microbiological methods, such as optochin susceptibility and bile solubility. Several various molecular approaches that address the issue of correct identification of pneumococci and other Mitis streptococci have been proposed and are discussed in this review, including PCR- and gene sequencing-based tests as well as new developments in the genomic field that represents an important advance in our understanding of relationships within the Mitis group.

Relationships among streptococci from the mitis group, misidentified as Streptococcus pneumoniae.

The aim of our study was to investigate phenotypic and genotypic features of streptococci misidentified (misID) as Streptococcus pneumoniae, obtained over 20 years from hospital patients in Poland. Sixty-three isolates demonstrating microbiological features typical for pneumococci (optochin susceptibility and/or bile solubility) were investigated by phenotypic tests, lytA and 16S rRNA gene polymorphism and whole-genome sequencing (WGS). All isolates had a 6-bp deletion in the lytA 3' terminus, characteristic for Mitis streptococc and all but two isolates lacked the pneumococcal signature cytosine at nucleotide position 203 in the 16S rRNA genes. The counterparts of psaA and ply were present in 100% and 81.0% of isolates, respectively; the spn9802 and spn9828 loci were characteristic for 49.2% and 38.1% of isolates, respectively. Phylogenetic trees and networks, based on the multilocus sequence analysis (MLSA) scheme, ribosomal multilocus sequence typing (rMLST) scheme and core-genome analysis, clearly separated investigated isolates from S. pneumoniae and demonstrated the polyclonal character of misID streptococci, associated with the Streptococcus pseudopneumoniae and Streptococcus mitis groups. While the S. pseudopneumoniae clade was relatively well defined in all three analyses, only the core-genome analysis revealed the presence of another cluster comprising a fraction of misID streptococci and a strain proposed elsewhere as a representative of a novel species in the Mitis group. Our findings point to complex phylogenetic and taxonomic relationships among S. mitis-like bacteria and support the notion that this group may in fact consist of several distinct species.

Mutations in cdsA and pgsA Correlate with Daptomycin Resistance in Streptococcus mitis and S. oralis.

We investigated the ability of several recent clinical viridans group streptococci (VGS) bloodstream isolates (Streptococcus mitis/S. oralis subgroup) from daptomycin (DAP)-naive patients to develop DAP resistance in vitro All strains rapidly developed high-level and stable DAP resistance. Substitutions in two enzymes involved in the cardiolipin biosynthesis pathway were identified, i.e., CdsA (phosphatidate cytidylyltransferase) and PgsA (CDP-diacylglycerol-glycerol-3-phosphate-3-phosphatidyltransferase). These mutations were associated with complete disappearance of phosphatidylglycerol and cardiolipin from cell membranes. DAP interactions with the cell membrane differed in isolates with PgsA versus CdsA substitutions.

Bacterial signatures in thrombus aspirates of patients with lower limb arterial and venous thrombosis.

OBJECTIVE: Increasing data supports the role of bacterial inflammation in adverse events of cardiovascular and cerebrovascular diseases. In our previous research, DNA of bacterial species found in coronary artery thrombus aspirates and ruptured cerebral aneurysms were mostly of endodontic and periodontal origin, where Streptococcus mitis group DNA was the most common. We hypothesized that the genomes of S mitis group could be identified in thrombus aspirates of patients with lower limb arterial and deep venous thrombosis. METHODS: Thrombus aspirates and control blood samples taken from 42 patients with acute or acute-on-chronic lower limb ischemia (Rutherford I-IIb) owing to arterial or graft thrombosis (n = 31) or lower limb deep venous thrombosis (n = 11) were examined using a quantitative real-time polymerase chain reaction to detect all possible bacterial DNA and DNA of S mitis group in particular. The samples were considered positive, if the amount of bacterial DNA in the thrombus aspirates was 2-fold or greater in comparison with control blood samples. RESULTS: In the positive samples the mean difference for the total bacterial DNA was 12.1-fold (median, 7.1), whereas the differences for S mitis group DNA were a mean of 29.1 and a median of 5.2-fold. Of the arterial thrombus aspirates, 57.9% were positive for bacterial DNA, whereas bacterial genomes were found in 75% of bypass graft thrombosis with 77.8% of the prosthetic grafts being positive. Of the deep vein thrombus aspirates, 45.5% contained bacterial genomes. Most (80%) of bacterial DNA-positive cases contained DNA from the S mitis group. Previous arterial interventions were significantly associated with the occurrence of S mitis group DNA (P = .049, Fisher's exact test). CONCLUSIONS: This is the first study to report the presence of bacterial DNA, predominantly of S mitis group origin, in the thrombus aspirates of surgical patients with lower limb arterial and deep venous thrombosis, suggesting their possible role in the pathogenesis of thrombotic events. Additional studies will, however, be needed to reach a final conclusion.

A Descriptive Study of Chlorhexidine as a Disinfectant in Cleft Palate Surgery.

OBJECTIVES: Chlorhexidine is seen as the golden standard of disinfectants. It is widely used to clean surgical sites; however, many studies indicate resistance of pathogens to chlorhexidine. One study indicated that pathogenic microorganisms were isolated from the soft palate cleft region in 57% of patients with facial clefts. The objectives of our study were to determine (1) if chlorhexidine application is effective in removing pathogens from the surgical site in these patients, and (2) if any pathogens are isolated, determine if they are resistant to other antimicrobials. DESIGN: A descriptive observational study. SETTINGS: A private practice that specializes in facial cleft surgery, with a country-wide patient base. All procedures were executed by one oral and maxillofacial surgeon. PARTICIPANTS: All patients (N=50) who presented for primary repair of the soft palate cleft were included in the study. INCLUSION CRITERIA: written consent from parent(s), and patient cleared as systemically healthy by a pediatric physician. EXCLUSION CRITERIA: patient(s) with systemic infections (eg, flu) and/or any local infections (eg, tonsillitis). There were 25 males and 25 females with an average age of 7 months and 16 days included in the study. METHODS: Swabs were taken from the surgical site of all 50 patients with cleft soft palate and were sent for culture, identification and antimicrobial sensitivity. The swabs were taken before disinfecting the site as well as after 2 minutes of disinfecting the surgical site with chlorhexidine. Results were compared against each other. RESULTS: Positive cultures with 28 different pathogenic microorganisms that were identified in 47 patients before cleaning the surgical site with the chlorhexidine. The most dominant pathogens were K. pneumonia (n=22), H. influenza (n=18) and S. aureus (n=10). Of the pathogens found, 13 (46%) were still present on the swabs taken after disinfecting with chlorhexidine. K. pneumonia (n= 13), H. influenza (n=11) and S. aureus (n=9) were still the most prevalent pathogens. CONCLUSIONS: This study demonstrated that 61 of the total of 113 pathogens isolated (54%), survived after 2 minutes of disinfecting the surgical and surrounding area with chlorhexidine, thus intensifying the chances of post-operative infection.

A Case Report of Penicillin-Tolerant Streptococcus mitis Endocarditis Chang-Hua Chen, MD, MSc, PhD.

There is no clear relationship between the serum inhibition test and clinical outcome for Streptococcus mitis (S. mitis) endocarditis. We report an 84-year-old male with endocarditis caused by penicillin-tolerant S. mitis. The results for the serum inhibitory test (SIT) and serum bactericidal test (SBT) showed a trough level of SIT = 1:256 and SBT = 1:4 and a peak level of SIT ≥ 1:1024 and SBT = 1:16. In addition, the SIT/SBT ratio was 64 at peak level and more than 64 at trough level, which is compatible with penicillin-tolerant S. mitis. Following a 42-day high-dose penicillin treatment (24 M IU/day, via a continuous drip), the patient made a good recovery. In vitro inhibitory and bactericidal test results were not a valid predictor of medical treatment failure. Physicians need to continue to evaluate the surgical indications when treating patients with S. mitis endocarditis.

Streptococcus mitis and S. oralis Lack a Requirement for CdsA, the Enzyme Required for Synthesis of Major Membrane Phospholipids in Bacteria.

Synthesis and integrity of the cytoplasmic membrane are fundamental to cellular life. Experimental evolution studies have hinted at unique physiology in the Gram-positive bacteria Streptococcus mitis and S. oralis These organisms commonly cause bacteremia and infectious endocarditis (IE) but are rarely investigated in mechanistic studies of physiology and evolution. Unlike in other Gram-positive pathogens, high-level (MIC ≥ 256 µg/ml) daptomycin resistance rapidly emerges in S. mitis and S. oralis after a single drug exposure. In this study, we found that inactivating mutations in cdsA are associated with high-level daptomycin resistance in S. mitis and S. oralis IE isolates. This is surprising given that cdsA is an essential gene for life in commonly studied model organisms. CdsA is the enzyme responsible for the synthesis of CDP-diacylglycerol, a key intermediate for the biosynthesis of all major phospholipids in prokaryotes and most anionic phospholipids in eukaryotes. Lipidomic analysis by liquid chromatography-mass spectrometry (LC-MS) showed that daptomycin-resistant strains have an accumulation of phosphatidic acid and completely lack phosphatidylglycerol and cardiolipin, two major anionic phospholipids in wild-type strains, confirming the loss of function of CdsA in the daptomycin-resistant strains. To our knowledge, these daptomycin-resistant streptococci represent the first model organisms whose viability is CdsA independent. The distinct membrane compositions resulting from the inactivation of cdsA not only provide novel insights into the mechanisms of daptomycin resistance but also offer unique opportunities to study the physiological functions of major anionic phospholipids in bacteria.

Diversity of Mosaic pbp2x Families in Penicillin-Resistant Streptococcus pneumoniae from Iran and Romania.

Penicillin-resistant Streptococcus pneumoniae strains are found at high rates in Romania and Iran. The mosaic structure of PBP2x was investigated in 9 strains from Iran and in 15 strains from Romania to understand their evolutionary history. Mutations potentially important for ß-lactam resistance were identified by comparison of the PBP2x sequences with the sequence of the related PBP2x of reference penicillin-sensitive S. mitis strains. Two main PBP2x mosaic gene families were recognized. Eight Iranian strains expressed PBP2x variants in group 1, which had a mosaic block highly related to PBP2x of the Spain23F-1 clone, which is widespread among international penicillin-resistant S. pneumoniae clones. A second unique PBP2x group was observed in Romanian strains; furthermore, three PBP2x single mosaic variants were found. Sequence blocks of penicillin-sensitive strain S. mitis 658 were common among PBP2x variants from strains from both countries. Each PBP2x group contained specific signature mutations within the transpeptidase domain, documenting the existence of distinct mutational pathways for the development of penicillin resistance.

Improved Differentiation of Streptococcus pneumoniae and Other S. mitis Group Streptococci by MALDI Biotyper Using an Improved MALDI Biotyper Database Content and a Novel Result Interpretation Algorithm.

Reliable distinction of Streptococcus pneumoniae and viridans group streptococci is important because of the different pathogenic properties of these organisms. Differentiation between S. pneumoniae and closely related Sreptococcusmitis species group streptococci has always been challenging, even when using such modern methods as 16S rRNA gene sequencing or matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. In this study, a novel algorithm combined with an enhanced database was evaluated for differentiation between S. pneumoniae and S. mitis species group streptococci. One hundred one clinical S. mitis species group streptococcal strains and 188 clinical S. pneumoniae strains were identified by both the standard MALDI Biotyper database alone and that combined with a novel algorithm. The database update from 4,613 strains to 5,627 strains drastically improved the differentiation of S. pneumoniae and S. mitis species group streptococci: when the new database version containing 5,627 strains was used, only one of the 101 S. mitis species group isolates was misidentified as S. pneumoniae, whereas 66 of them were misidentified as S. pneumoniae when the earlier 4,613-strain MALDI Biotyper database version was used. The updated MALDI Biotyper database combined with the novel algorithm showed even better performance, producing no misidentifications of the S. mitis species group strains as S. pneumoniae All S. pneumoniae strains were correctly identified as S. pneumoniae with both the standard MALDI Biotyper database and the standard MALDI Biotyper database combined with the novel algorithm. This new algorithm thus enables reliable differentiation between pneumococci and other S. mitis species group streptococci with the MALDI Biotyper.

Streptococcus mitis and Gemella haemolysans were simultaneously found in atherosclerotic and oral plaques of elderly without periodontitis-a pilot study.

OBJECTIVES: Local infections may contribute to the initiation and progression of several clinical diseases in humans. Atherosclerotic plaques of subjects suffering from periodontitis are colonized by periopathogens; however, the presence of bacteria in atherosclerotic plaques in patients without severe forms of periodontitis is of high relevance for the general population. MATERIALS AND METHODS: Patients who were electively treated for atherosclerotic lesions of the carotid artery and without clinical signs of periodontitis were eligible for the study. Oral and atherosclerotic plaques were sampled, processed, and analyzed for their microbial composition by 454-sequencing. RESULTS: Seventeen patients were included in the analyses, and 76 % of all atherosclerotic plaque specimens were positive for bacterial DNA. In the oral plaques, 76,532 sequences were identified representing 1 phylum, 17 classes, 112 families, and 263 genera. In atherosclerotic plaques, 6112 sequences representing 1 phylum, 4 classes, 8 families, and 36 genera were found. The bacterial DNAs of the species Gemella haemolysans and Streptococcus mitis were simultaneously found in atherosclerotic as well as oral plaque samples of 3 patients. CONCLUSIONS: These results indicated that in subjects without periodontitis, the transmission of oral bacteria to atherosclerotic plaques of the carotid artery is a feasible event. CLINICAL RELEVANCE: The prevention of transient bacteremia from the oral cavity requires high levels of oral health.

Composition and Antibacterial Activity of the Essential Oils of Orthosiphon stamineus Benth and Ficus deltoidea Jack against Pathogenic Oral Bacteria.

In this study, the essential oils of Orthosiphon stamineus Benth and Ficus deltoidea Jack were evaluated for their antibacterial activity against invasive oral pathogens, namely Enterococcus faecalis, Streptococcus mutans, Streptococcus mitis, Streptococcus salivarius, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum. Chemical composition of the oils was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The antibacterial activity of the oils and their major constituents were investigated using the broth microdilution method (minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC)). Susceptibility test, anti-adhesion, anti-biofilm, checkerboard and time-kill assays were also carried out. Physiological changes of the bacterial cells after exposure to the oils were observed under the field emission scanning electron microscope (FESEM). O. stamineus and F. deltoidea oils mainly consisted of sesquiterpenoids (44.6% and 60.9%, respectively), and ß-caryophyllene was the most abundant compound in both oils (26.3% and 36.3%, respectively). Other compounds present in O. stamineus were α-humulene (5.1%) and eugenol (8.1%), while α-humulene (5.5%) and germacrene D (7.7%) were dominant in F. deltoidea. The oils of both plants showed moderate to strong inhibition against all tested bacteria with MIC and MBC values ranging 0.63-2.5 mg/mL. However, none showed any inhibition on monospecies biofilms. The time-kill assay showed that combination of both oils with amoxicillin at concentrations of 1× and 2× MIC values demonstrated additive antibacterial effect. The FESEM study showed that both oils produced significant alterations on the cells of Gram-negative bacteria as they became pleomorphic and lysed. In conclusion, the study indicated that the oils of O. stamineus and F. deltoidea possessed moderate to strong antibacterial properties against the seven strains pathogenic oral bacteria and may have caused disturbances of membrane structure or cell wall of the bacteria.

Polymicrobial vertebral osteomyelitis after oesophageal biopsy: a case report.

BACKGROUND: While most cases of polymicrobial vertebral osteomyelitis are secondary to hematogenous seeding, direct inoculation during spinal surgery and contiguous spread from adjacent soft tissue are also potential routes whereby pathogens may infect the spine. CASE PRESENTATION: A 74 year-old man presented with an exacerbation of back pain after a fall. His past medical history included hepatocellular and oesophageal carcinoma. Three months earlier he had undergone an endoscopic biopsy of the oesophagus for routine follow-up of his oesophagus carcinoma. He also underwent a vertebroplasty due to suspected pathologic fracture. On admission to hospital, magnetic resonance imaging revealed an infiltrative process at the level of the 5th and 6th thoracic vertebrae. Blood cultures were positive for both Streptococcus mitis and Gemella morbillorum. During his course of antibiotic therapy he developed an abscess at the level of 8th thoracic vertebrae and culture of this abscess grew Candida albicans. He was treated with antibiotics and antifungal drugs and recovered fully. CONCLUSION: Vertebral osteomyelitis may be caused by direct spread following an oesophageal procedure. Microbiological diagnosis is essential to target the specific pathogen, especially in cases of polymicrobial infection.

Arthritis-induced alveolar bone loss is associated with changes in the composition of oral microbiota.

Rheumatoid arthritis (RA) and periodontitis (PD) are chronic inflammatory disorders that cause bone loss. PD tends to be more prevalent and severe in RA patients. Previous experimental studies demonstrated that RA triggers alveolar bone loss similarly to PD. The aim of this study was to investigate if arthritis-induced alveolar bone loss is associated with modification in the oral microbiota. Checkerboard DNA-DNA hybridization was employed to analyze forty oral bacterial species in 3 groups of C57BL/6 mice: control (n = 12; without any challenge); Y4 (n = 8; received oral inoculation of Aggregatibacter Actinomycetemcomitans strain FDC Y4) and AIA group (n = 12; chronic antigen-induced arthritis). The results showed that AIA and Y4 group exhibited similar patterns of bone loss. The AIA group exhibited higher counts of most bacterial species analyzed with predominance of Gram-negative species similarly to infection-induced PD. Prevotella nigrescens and Treponema denticola were detected only in the Y4 group whereas Campylobacter showae, Streptococcus mitis and Streptococcus oralis were only found in the AIA group. Counts of Parvimonas micra, Selenomonas Noxia and Veillonella parvula were greater in the AIA group whereas Actinomyces viscosus and Neisseira mucosa were in large proportion in Y4 group. In conclusion, AIA is associated with changes in the composition of the oral microbiota, which might account for the alveolar bone loss observed in AIA mice.

Assessment of Correlation between Clinical Parameters and Pulp Canal Pathogens in Endodontic Pathologies: A Microbiological Study.

INTRODUCTION: Success and failure of root canal therapy is largely dependent on the clinician and the patient. Once the tooth is restored into its functional and esthetic place, the root canal therapy is considered to be complete. It is a well-known fact that root canal space acts as a rich reservoir for microorganisms. Past studies show that root canal harbors an array of different microorganisms. Streptococcus mitis and Enterococcus faecalis have been found to be the most prevalent microorganisms isolated from the infected pulp canal space. Hence, we evaluated the association of endodontic signs and symptoms with root canal pathogens. MATERIALS AND METHODS: A total of 120 patients were selected for the study and divided broadly into two groups: Group I containing patients with primary infection and group II containing patients in which retreatment was required. Both groups contained 60 patients each. Clinical parameters recorded for the study are pain, tenderness on percussion, swelling, periapical radiolucency on radiographic analysis, caries, sinus formation, and tooth mobility. After assessment, opening, and initial filing, sterile paper points were inserted into the root canal space for collection of microbiological sample, which was further send to laboratory for cultural analysis. All the results were analyzed by Statistical Package for the Social Sciences (SPSS) software. Student's t-test and Fisher's exact test were used to evaluate the level of significance. RESULTS: While comparing the mean age of the patients in the two groups, no significant association was seen. Statistically significant results were obtained while comparing the association between pain and S. mitis. Positive correlation was seen on comparing the association between tenderness on percussion and E. faecalis. Also, a positive association was seen between periapical radiolucency and S. mitis. CONCLUSION: Strong positive correlation exists between S. mitis and E. faecalis and endodontic signs and symptoms. CLINICAL SIGNIFICANCE: Sound knowledge regarding the association of microbes of root canal and specific endodontic signs and symptoms could help therapeutic management of root canal infections effectively.

An in vivo comparison of internal bacterial colonization in two dental implant systems: identification of a pathogenic reservoir.

OBJECTIVES: The aim of this study was to compare internal bacterial colonization in two implant systems, one screw root form (SRF) with an external hexagon connection and one plateau root form (PRF) with a Morse taper internal connection. MATERIALS AND METHODS: Thirty-two implants; 12 SRF and 20 PRF, were sampled in 15 patients. All implants had been in function for at least 6 months prior to sampling. The implant restoration was removed and 10 µl of sterile saline was introduced into the implant well via a sterile glass syringe. The saline was drawn back up and transferred to the laboratory for microbiological analysis. The number of aerobic and anaerobic colony forming units per millilitre was determined and the dominant micro-organism in each sample was identified by 16s rRNA gene amplicon sequencing. RESULTS: There was a significant difference between bleeding on probing around the SRF implants (3%) and the PRF implants (28%) (p = 0.0496). Bacterial colonization was identified at 11 SRF and 19 PRF implants. The numbers of anaerobic bacteria recovered from PRF implants was significantly higher than that from SRF implants (p = 0.0002). Streptococcus species and Enterococcus faecalis were found to dominate. CONCLUSIONS: This in vivo study demonstrated bacterial colonization in both types of implant systems, irrespective of the type of connection. Significantly greater anaerobic counts were found in the Morse taper internal connection implants.

Histopathology of streptococcus mitis/oralis endophthalmitis after intravitreal injection with bevacizumab: a report of 7 patients.

PURPOSE: To report the histopathologic findings of a series of patients from an outbreak of Streptococcal endophthalmitis after intravitreal injection of bevacizumab prepared by a single compounding pharmacy. DESIGN: Case series. PARTICIPANTS: Seven surgical specimens (5 enucleated globes and 2 evisceration specimens) from 7 patients with endophthalmitis after intravitreal injection of bevacizumab. METHODS: Retrospective case series, including clinical data and histopathologic specimens examined by light microscopy. MAIN OUTCOME MEASURES: Review of clinical data included baseline visual acuity, clinical intervention, and time elapsed from injection to loss of globe. Histopathologic specimens were reviewed for pathologic changes at all tissue levels. RESULTS: Seven of 12 total patients (4 women, 3 men; mean age, 77.7 years) from an outbreak of Streptococcus mitis/oralis endophthalmitis after bevacizumab injection ultimately sustained loss of the affected globe, with an average of 139.1 days elapsed between injection and globe loss. Mean time from injection to presentation was 2.86 days (range, 1-6), and all patients were initially treated with vitreous tap and injection. Although histologic review of surgical specimens disclosed a wide range of pathologic tissue changes, recurring patterns of tissue damage were evident. All 5 enucleated globes displayed retinal detachment, fibrous proliferation with cyclitic membrane formation, rubeosis iridis, and secondary angle closure. All 7 specimens displayed persistent choroidal inflammation, in 1 case 208 days after injection. Six of 7 specimens had foci of retinal necrosis. Although vitreous cultures were positive in all cases, no organisms were identified by light microscopy in any of the 7 specimens. CONCLUSIONS: S. mitis/oralis endophthalmitis is a devastating complication of intravitreal injection with bevacizumab with a high rate of globe loss (7 of 12 patients, 58.3%) and a wide variety of severe pathologic tissue changes. Although no organisms were identified in the examined tissues, persistent inflammation was present in all cases, and fibrous proliferation resulted in cyclitic membrane formation and retinal detachment in all enucleated globes. These findings suggest that potential globe-salvaging interventions must address a pattern of changes involving persistent, chronic inflammation and fibrovascular proliferation as key components.

Streptococcus mitis/oralis endophthalmitis management without phakic intraocular lens removal in patient with iris-fixated phakic intraocular lens implantation.

BACKGROUND: To report a case of Streptococcus mitis/oralis endophthalmitis management which had developed after complicated iris-fixated phakic intraocular (pIOL) lens implantation. CASE PRESENTATION: A 23-year-old-woman received pIOL implantation followed secondary intraocular intervention to lower intraocular pressure. The patient presented with severe pain and decreased visual acuity and was managed with intravitreal and intracameral antibiotic injection with topical applications of fortified antibiotics. Culture of aqueous humor was positive for S. mitis/oralis, which was sensitive to the empiric antibiotic regimen. Clinical features started to improve 5 days after treatment and the pIOL was left in place. The uncorrected distant visual acuity and endothelial cell count were 20/32 and 3143 cells/mm2 four weeks after treatment, respectively. CONCLUSION: S. mitis/oralis endophthalmitis after pIOL implantation could be managed with appropriate antibiotic administration without pIOL removal if accompanied by rapid clinical improvement after the initial intensive management in the absence of vitreous involvement.

Culture negative empyema in a critically ill child: an opportunity for rapid molecular diagnostics.

BACKGROUND: Nucleic acid amplification technologies (NAAT) are advancing our ability to make rapid molecular diagnoses in patients with serious culture negative infections. This is the first report of PCR coupled to electrospray ionization mass spectrometry use in the evaluation of complicated community acquired pneumonia in a pediatric patient. CASE PRESENTATION: We present a case of culture negative empyema in a critically ill, Caucasian, 2-year-old girl who was treated with broad-spectrum empiric antibiotics, in which the length of stay was prolonged by adverse effects of the empiric antibiotic treatment. PCR coupled to electrospray ionization mass spectrometry was applied to culture negative fluid and tissue samples from the patient in order to determine the etiology of the empyema. CONCLUSIONS: Using this method, Streptococcus mitis/viridans was identified as the pathogen. A retrospective review of cases of empyema in children at our institution found that 87.5% of cases were negative for identification of a pathogen and antibiotics were administered to 100% of cases prior to collecting pleural fluid for culture. Understanding the role of Streptococcus mitis/viridans group in the etiology of empyema using an advanced NAAT coupled with mass spectrometry can enlighten clinicians as to the impact of this pathogen in community acquired pneumonia and help assist with antibiotic stewardship.

Bacteremia after piezocision.

INTRODUCTION: The aim of this study was to investigate the presence of transient bacteremia after a piezocision procedure. METHODS: The sample consisted of 30 subjects (24 women, 6 men; mean age, 19.6 ± 0.7 years; range, 18.1-22.4 years) with the American Society of Anesthesiologists' physical status I. All patients had Class I skeletal and dental relationships and had fixed orthodontic treatment with the Damon system. The piezocision surgery was performed 1 week after the placement of the orthodontic appliances in all patients. Two 20-mL venous blood samples were collected before and 30 to 60 seconds after the first microincision using an aseptic technique. The samples were inoculated into BACTEC Plus aerobic and anaerobic blood culture bottles and were assessed in the BACTEC blood culture analyzer (Becton Dickinson Diagnostic Instrument Systems, Sparks, Md). The results were analyzed statistically using the McNemar test, with P <0.05 indicating statistical significance. RESULTS: No significant difference between the preoperative and postoperative samples was determined with respect to transient bacteremia (P = 0.250). No bacteremia was detected in the pretreatment samples, although Gemella sanguinis, Streptococcus pluranimalium, and Streptococcus mitis/oralis were detected in 3 postoperative blood samples. CONCLUSIONS: The piezocision procedure might be related to transitory bacteremia. Hence, orthodontists should consider the possibility of bacterial endocarditis in at-risk patients when piezocision is part of the treatment plan.