Infective endocarditis due to Streptococci and Enterococci: A 3-year retrospective study.

INTRODUCTION: Infective endocarditis (IE) is an infection of the heart valves with an aggregation of bacteria in a fibrin plaque called vegetation. AIMS AND OBJECTIVES: This is a retrospective study of all infective endocarditis cases due to alpha haemolytic streptococci and enterococci. METHODS: All cases of infective endocarditis cases due to alpha haemolytic streptococci and enterococci in a period of three years from 1st January 2010 to 31st December 2012 were included. Isolation of the same organism from more than one set of blood cultures was taken as a confirmed case of infective endocarditis. Clinical and serological parameters were recorded using a proforma. RESULTS: Native valve endocarditis was more common with only five prosthetic valves being involved. Out of 89 clinically suspected cases of IE in the three years from Jan 2010 to Dec 2012, for which blood was sent for culture, 63(70.78%) samples were positive by culture. Of these, 42/63(66.66%) were due to alpha-lytic Streptococci, enterococci and rare gram positive cocci. The rare ones included Enterococcus gallinarum, abiotropha defective, Vagococcus fluvialis and Nutritionally Variant Streptococci(NVS). High level Aminoglycoside resistance(HLAR) was also encountered. The varied and important features of these isolates are discussed. Complications and treatment are described. CONCLUSION: From a clinical microbiology point of view, the major challenge faced by the microbiologist in diagnosis of IE is proper aseptic collection of sample before starting antibiotics with a need for multiple samples to detect and also to prove the causative organism. Sensitivity reporting can be a difficult task in the context of NVS, HLAR and gram positives that are slow growing. Congestive failure and embolisation occurs even when the antibiotic treatment is successful.When patients go in for complications, it is very rarely due to wrong antibiotics.

Functionalized carbon dots enable simultaneous bone crack detection and drug deposition.

Recently, carbon dots (CDs) have become one of the most sought nanomaterials for biological applications owing to their excellent fluorescence, chemical inertness and biocompatibility. This article depicts the generation of a fluorescent nano probe using CDs for viewing bone cracks and simultaneous drug delivery to the cracked or infected sites. Water soluble polyethylene glycol diamine capped CDs were conjugated with glutamic acid (GA), a calcium targeting ligand, and ciprofloxacin as an antibacterial model drug. Physicochemical characterizations, cytotoxicity evaluation, haemolysis and antibacterial activity studies of the synthesized probe and its ability to target onto bone are demonstrated. Our results indicate that there is significant scope in developing functionalized CDs as theranostic agents.

Kodamaea ohmeri tricuspid valve endocarditis with right ventricular inflow obstruction in a neonate with structurally normal heart.

The yeast Kodamaea (Pichia) ohmeri is a rare human pathogen with infrequent report of neonatal infection. Native valve endocarditis by Kodamaea ohmeri is extremely rare. The current case report describes a case of fatal nosocomial native valve endocarditis without any structural heart defects in a 40dayold baby. The patient was referred to our institute after having ICU stay of 18 days in another hospital for necrotizing enterocolitis and was found to have obstructive tricuspid valve mass and fungemia with Kodamaea ohmeri. In spite of the treatment, patient developed sepsis with disseminated intravascular coagulation and could not be revived.

High polymeric IgA content facilitates recognition of microbial polysaccharide-natural serum antibody immune complexes by immobilized human galectin-1.

Dextran-binding immunoglobulin (DIg) and anti-ß-glucan antibody (ABG) are naturally occurring human serum antibodies specific to α- and ß-glucoside epitopes respectively of polysaccharide antigens and heavily enriched in IgA. ABG and DIg are shown here to have much more of their IgA in polymeric form than does serum IgA in general. Cell wall ß-glucans and glycoproteins of the widely consumed yeast (Saccharomyces cerevisiae) offered several hundred fold better ligands for ABG than did small ß-glucosides. Candida albicans cell wall antigen (CCA), a commonly encountered polysaccharide-rich fungal antigen was recognized by normal human serum anti-carbohydrate antibodies to precipitate maximally at a definite stoichiometry typical of immune complexes (IC). IC formed in serum in vitro on addition of CCA contained a significantly higher percentage of IgA than did either naturally occurring IC or serum. Polymeric IgA was far better ligand than monomeric IgA for both anti-IgA antibody and the most widely expressed human tissue lectin galectin-1 which recognizes O-linked oligosaccharides characteristic of IgA, in contrast to N-linked oligosaccharides present in all immunoglobulins. Moreover, desialylation by neuraminidase, an enzyme released into circulation during many microbial infections and diabetes, increased lectin-binding activity of polymeric IgA much more than that of monomeric IgA. Human galectin-1 immobilized in active form in vitro sugar-specifically captured IgA and IgA-containing IC formed by CCA in serum but not IgG. Results suggest that while high IgA content especially in polymeric form may render polysaccharide IC more susceptible to tissue uptake, desialylation of IgA in IC could enhance the process.

An elusive diagnosis: Scedosporium apiospermum infection after near-drowning.

A 51-year-old male was admitted in our institute following an episode of near-drowning. He later developed ventriculitis and cerebral ring-enhancing lesions. He died following a subarachnoid hemorrhage due to rupture of a mycotic aneurysm involving the right fetal posterior cerebral artery. Scedosporium apiospermum was isolated from the cerebrospinal fluid. Central nervous system invasion by S apiospermum may present insidiously in near-drowning patients and, therefore, requires a high index of suspicion. In cases with the characteristic cerebral ring-enhancing lesions and concomitant ventriculitis, treatment should be instituted while awaiting fungal culture. With this article we intend to alert neurologists, intensivists, and physicians to this near fatal infection, as early identification and prompt treatment with voriconazole may be life saving.