Medical treatment of staphylococcal infective endocarditis

Staphylococcal infective endocarditis is a severe event requiring aggressive therapy. Antibiotic regimen depends mainly on (1) the species of Staphylococcus (Staphylococcus aureus versus coagulase-negative staphylococci) and its resistance pattern (resistance to penicillin, to methicillin, to multiple classes of antibiotics); (2) the type of infected valve (native versus prosthetic); (3) the site of infection (left side versus right side endocarditis); (4) some underlying conditions of the host, in particular the presence or not of intravenous drug abuse. Based on in vitro susceptibility results, animal models and clinical trials, the following regimens are currently recommended. For native valve endocarditis, penicillin G 20 million units per i.v. for 4-6 weeks for penicillin-susceptible strains; a penicillinase-resistant penicillin (oxacillin) 2 g i.v. q 4 h for 4-6 weeks plus an aminoglycoside (gentamicin) 1.0 mg.kg−1 i.v. q 8 h for 1 week, for penicillin-resistant, methicillin-susceptible strains; for methicillin resistant strains, vancomycin 30 mg.kg.day−1 i.v. in 2—4 doses for 4—6 weeks with the addition or not of rifampin 600-900 mg.day−1 orally. For a prosthetic valve endocarditis, a three-drug regimen (oxacillin or vancomycin, plus gentamicin and rifampin) and a longer duration (6 weeks or more) are generally recommended. Shorter (2 weeks) treatment could be delivered to uncomplicated cases of right-sided endocarditis. In view of an increased resistance to classic drugs and suboptimal efficacy of some of them, new therapeutic modalities should be looked at, in particular for endocarditis cases due to methicillin-resistant strain

Evaluation of the susceptibility of pathogenic Candida species to fluconazole

A fluconazole 25 ug disk diffusion test was used to test 2230 consecutively isolatedCandida strains from 42 different hospital laboratories in 23 countries. Ninety seven percent of 1634Candida albicans isolates and 83.4% of 596 non-Candida albicans isolates were susceptible to fluconazole, applying the proposed breakpoints (≥26 mm for susceptible strains and 18-25 mm for dosedependent susceptible strains). This is the first hospital laboratory study to evaluate a large number and wide range of sequentialCandida isolates from patients with all types of hospital infections. The fluconazole disk diffusion test appears to be a low-cost, reproducible, and accurate means of assessing the in vitro susceptibility ofCandida isolate

Prophylaxis of pyelonephritis by aminoglycosides accumulated in the kidney

When given prophylactically, gentamicin accumulates and persists in the rat kidney and affords protection against obstructive acute Escherichia coli pyelonephritis. Similar protection is observed after administration of amikacin, netilmicin and tobramycin, which accumulate to various degrees in the renal parenchyma. In those animals developing pyelonephritis despite aminoglycoside prophylaxis, renal infection and inflammation are reduced during the acute phase of the disease. This results in almost complete protection against renal scarring later on. Administrée à titre prophylactique, la Gentamicine s'accurnule dans le rein du rat et le protège contre l'apparition de pyélonéphrite aiguë à E. coli. Un effet protecteur identique est observé aprés administration d'Amikacine, de Nétilmicine, et de Tobramycine, qui s'accumulent à des degrés divers dans le parenchyme rénal. Chez l'animal, lorsqu'apparait une pyélonéphrite, malgré le traitement prophylactique par les aminoglycosides, l'infection et l'inflammation rénales sont diminuées durant la phase aiguë de la maladie. Ceci réduit le risque de lésion et de formation ultérieure de tissu cicatricie

Lymph node dissection in lung cancer surgery

Lung cancer, a leading cause of cancer-related death, often requires surgical resection for early-stage cases, with recent data supporting less invasive resections for tumors smaller than 2 cm. Central to resection is lymph node assessment, an area of controversy worldwide, compounded by advances in minimally invasive techniques. The review aims to assess current standards for lymph node assessment, recent data from the surgical era, and the immunobiological basis of how lymph node metastases impact patient outcomes. The British Thoracic Society guidelines recommend systematic nodal dissection during lung cancer resection, without specifying node removal or sampling. Historical data on mediastinal lymph node dissection (MLND) survival benefits are inconclusive, although proponents argue for lower recurrence rates. Recent trials such as ACOSOG Z0030 found no survival difference between MLND and nodal sampling, reinforcing the need for robust staging. While lobe-specific dissection strategies have been proposed, they currently lack consensus. JCOG1413 aims to compare the clinical benefits of lobe-specific and systematic dissection. TNM-9 staging revisions emphasize the prognostic significance of single-station N2 involvement. Robotic surgery shows promise, with trials such as RAVAL, which reported comparable outcomes to video-assisted thoracic surgery (VATS) and improved lymph node sampling. Immunobiological insights suggest preserving key immunological sites during lymphadenectomy, especially for patients receiving adjuvant immunotherapy. In conclusion, the standard lymph node resection strategy remains unsettled. The debate between systematic and selective dissection continues, with implications for staging accuracy and patient outcomes. As minimally invasive techniques evolve, robotic surgery emerges as an effective and low-risk approach to delivering optimal lymph node assessment

Single-Dose Rifampin Prophylaxis for Experimental Endocarditis Induced by High Bacterial Inocula of Viridans Streptococci

In rats challenged with viridans streptococci poorly susceptible to antibiotic killing, single doses of antibiotics only prevent endocarditis induced by bacterial inoculum sizes that produce disease in 90% of control animals (ID90) : additional doses are required to protect against inocula exceeding the ID90. We investigated whether single-dose rifampin would extend the efficacy of single-dose prophylaxis to inocula exceeding the ID90. We used two strains of viridans streptococci highly susceptible to killing by rifampin and two resistant strains. All rats wereinjected with 10-1,000 times the ID90 of the four strains. Single-dose rifampin successfully prevented endocarditis due to all four strains. A few prophylaxis failures were observed after challenge with the two poorly susceptible strains, but in vivo emergence of resistant variants did not account for these failures. Thus, rifampin was the first antibiotic given as a single dose that successfully prevented experimental streptococcus endocarditis after challenge with high bacterial inocul

Genome Sequences of Listeria monocytogenes Strains Responsible for Cheese- and Cooked Ham Product-Associated Swiss Listeriosis Outbreaks in 2005 and 2011.

The complete genome sequences of three Listeria monocytogenes serotype 1/2a strains, Lm 3136, Lm 3163, and Lm N1546, which were responsible for listeriosis outbreaks in 2005 and 2011 in Switzerland, are presented here

An Epidemic of Food-Borne Listeriosis in Western Switzerland: Description of 57 Cases Involving Adults

This article describes 57 cases of listeriosis that occurred in adults in western Switzerland during an outbreak associated with the consumption of a soft cheese. Twenty-one percent of the cases were of bacteremia, 40% were of meningitis, and 39% were of meningoencephalitis. Overall, 42% of the patients had an underlying disease and 54% were >65 years of age. Patients with bacteremia were significantly older than those with meningitis or meningoencephalitis (median ages, 75, 69, and 55 years, respectively). The epidemic strain, defined by phage typing, was isolated in three-quarters of the listerial cases observed during the epidemic period and did not appear to differ significantly from the nonepidemic strains in terms of virulence. The overall mortality associated with the 57 cases was 32%. Among the patients' characteristics, age and type of clinical presentation were independent predictors of death in a multivariate logistic regression model (pseudo-r2 [coefficient of determination], .26; both P values <.05), and a presentation of meningoencephalitis was associated with an increased death risk (odds ratio, 6.5; 95% confidence interval, 1.1-39.5; P < .05). Neurological sequelae developed in 30% of the survivors of CNS listeriosi

Hierarchical Relative Lempel-Ziv Compression

Relative Lempel-Ziv (RLZ) parsing is a dictionary compression method in which a string S is compressed relative to a second string R (called the reference) by parsing S into a sequence of substrings that occur in R. RLZ is particularly effective at compressing sets of strings that have a high degree of similarity to the reference string, such as a set of genomes of individuals from the same species. With the now cheap cost of DNA sequencing, such datasets have become extremely abundant and are rapidly growing. In this paper, instead of using a single reference string for the entire collection, we investigate the use of different reference strings for subsets of the collection, with the aim of improving compression. In particular, we propose a new compression scheme hierarchical relative Lempel-Ziv (HRLZ) which form a rooted tree (or hierarchy) on the strings and then compress each string using RLZ with parent as reference, storing only the root of the tree in plain text. To decompress, we traverse the tree in BFS order starting at the root, decompressing children with respect to their parent. We show that this approach leads to a twofold improvement in compression on bacterial genome datasets, with negligible effect on decompression time compared to the standard single reference approach. We show that an effective hierarchy for a given set of strings can be constructed by computing the optimal arborescence of a completed weighted digraph of the strings, with weights as the number of phrases in the RLZ parsing of the source and destination vertices. We further show that instead of computing the complete graph, a sparse graph derived using locality-sensitive hashing can significantly reduce the cost of computing a good hierarchy, without adversely effecting compression performance