In Vitro Activity of Gepotidacin, a Novel Triazaacenaphthylene Bacterial Topoisomerase Inhibitor, against a Broad Spectrum of Bacterial Pathogens.

Gepotidacin inhibits bacterial DNA replication through a mode different from that of fluoroquinolones. Gepotidacin and comparators were tested by broth and agar dilution against clinical isolates. The in vitro activities of gepotidacin were comparable against methicillin-susceptible and -resistant Staphylococcus aureus (MSSA and MRSA, respectively) isolates (MIC90, 0.5 µg/ml). The gepotidacin MIC90s were as follows (in micrograms per milliliter) for the indicated bacteria: Streptococcus pyogenes, 0.25; Escherichia coli, 2; Moraxella catarrhalis, ≤ 0.06; Streptococcus pneumoniae (0.25), Haemophilus influenzae, 1; Clostridium perfringens, 0.5; and Shigella spp., 1, including levofloxacin-resistant subsets. Gepotidacin warrants further investigation for clinical development.

Dissemination of NDM metallo-ß-lactamase genes among clinical isolates of Enterobacteriaceae collected during the SMART global surveillance study from 2008 to 2012.

The prevalence of carbapenemase enzymes continues to increase. Among the Ambler class B enzymes is the New Delhi metallo-ß-lactamase (NDM). This particular enzyme is capable of hydrolyzing nearly all ß-lactam antimicrobial agents and has spread rapidly, becoming a global problem. Therapeutic treatment options for patients infected with isolates which produce this enzyme are difficult to manage, as cross-resistance to other antimicrobial classes is common. The Study for Monitoring Antimicrobial Resistance Trends (SMART) is a global surveillance study evaluating the antimicrobial susceptibilities of numerous Gram-negative bacterial species recovered from people with intra-abdominal and urinary tract infections. The Clinical and Laboratory Standards Institute methods and a molecular analysis identified 134 isolates of Enterobacteriaceae (nine species) and one Acinetobacter sp. with blaNDM genes. These isolates were collected in nine countries, and >95% of the isolates possessed the NDM-1 variant. The MIC90 values were >4 mg/liter and >8 mg/liter for ertapenem and imipenem, respectively. No tested ß-lactam or ß-lactamase inhibitor combination had activity against these isolates. Resistance to amikacin (79.9%) and levofloxacin (82.8%) was common. Nearly all the isolates encoded additional enzymes, including AmpC cephalosporinases and extended-spectrum ß-lactamases. There is an urgent need for infection control and continued global monitoring of isolates which harbor the NDM enzyme, as evidenced by recent outbreaks.

Lumbar pressure and transcranial Doppler sonography in children with scaphocephaly.

The primary aim of this study was to assess whether there exists a relationship between lumbar cerebrospinal fluid (CSF) pressure and intracranial blood flow velocities as measured by transcranial Doppler sonography (TCD) in children with scaphocephaly. Another aim was to compare pre- and postoperative TCD. Using a transducer, lumbar CSF pressure (LP) was assessed in 21 children with scaphocephaly. TCD was performed, and the pulsatility index (PI) and the resistance index (RI) were obtained before and after cranioplasty. In 17 children LP was higher than the reference values. No significant differences were found in PI and RI indices before and after cranioplasty. LP values were significantly higher in children older than 6 months. There was no association between LP and PI and RI indices. In children with scaphocephaly a higher LP can be expected with age. Moreover, TCD is not a reliable tool in predicting abnormal LP values.

A new alternative method to quantify residual structure in 'unfolded' proteins.

Pig (pCSD1) and human (hCSD1) calpastatin domain 1 proteins were studied to characterize common features of the denatured state of proteins. These proteins were chosen for the present investigation, because pCSD1 was suggested previously to be unstructured in water even at 25 degrees C (1) [T. Konno et al., Biochim. Biophys. Acta 1342 (1997) 73-82]. hCSD1 could be expected to exhibit similar features on the basis of preliminary spectroscopic studies. In the present study, the experimental grounds for the estimate of residual structure in the unfolded state were differential scanning calorimetry heat capacity and circular dichroism (CD) measurements over the temperature range 10-80 degrees C. At selected temperatures, we studied also the effect of guanidinium hydrochloride (GdnHCl) which is known to promote further unfolding of the polypeptide chain. All other measurements were performed at pH 6 in pure water. The present results support the conclusion that the comparison of the experimentally obtained heat capacity data with theoretical heat capacity values calculated on the basis of a newly established increment system gives insight into the degree of hydration of the unfolded polypeptide chain. The percentage by which the experimental heat capacity of the unfolded polypeptide chain differs from the calculated heat capacity permits a quantitative estimate of the residual structure. This estimate is in good agreement with that based on CD absorption. The heat capacity approach has the advantage of comparing fully hydrated and partially hydrated residues in the same aqueous environment, whereas for example spectroscopic measurements, such as CD, are generally referred to the fully unfolded chain in concentrated urea or GdnHCl solutions. As the unfolded chains of pCSD1 and hCSD1 exhibit a smaller heat capacity than that calculated on the new peptide-based increment system [M. Häckel et al., J. Mol. Biol. 291 (1999) 197-213], we conclude that the residues in the unfolded polypeptide chain are less hydrated than the same residues in oligopeptides. This suboptimal hydration is the result of residual structure in the chain as observed in both CD and heat capacity measurements.

A new set of peptide-based group heat capacities for use in protein stability calculations.

The partial molar heat capacities of the tripeptides of the sequence glycyl-X-glycine, where X is one of the amino acids leucine, threonine, glutamine, phenylalanine, histidine, cysteine, proline, glutamic acid or arginine, and of the two tetrapeptides tetraglycine and glycyltryptophanylglycylglycine in aqueous solution over the temperature range 10-100 degrees C have been determined using high sensitivity scanning microcalorimetry. These results were used to derive the partial molar heat capacities of the various amino acid side-chains. This report completes our programme to derive reliable side-chain heat capacities for all 20 amino acids of proteins over a wide temperature range using the tripeptides Gly-X-Gly as realistic model compounds. Included in the study is a summary of the partial molar heat capacities of all 20 amino acid side-chains. These results, along with the heat capacity of the peptide backbone group, were used to calculate the partial molar heat capacities of some oligopeptides and of the random coil form of some unfolded proteins in water. The calculated heat capacities of the proteins obtained using this new set of heat capacities for the constituent groups are consistent with the heat capacities of the denatured state determined experimentally.

The partial molar heat capacity and volume of the peptide backbone group of proteins in aqueous solution.

The partial molar heat capacities have been determined for the series of peptides alanyl(glycyl)(x)glycine, x=1-3, and for the compounds N-acetylglycinamide and N-acetyl glycylglycinamide in aqueous solution over the temperature range 10-100 degrees C using high sensitivity scanning microcalorimetry. The partial molar volumes for these compounds have also been determined over the temperature range from 10 to 90 degrees C using a scanning densimetric method. The results were used to derive the partial molar heat capacities and volumes of the glycyl group at temperatures in the range 10-100 degrees C. The results obtained are critically compared with literature results derived using heat capacity and volume data for some oligoglycines.

Partial molar volumes of proteins: amino acid side-chain contributions derived from the partial molar volumes of some tripeptides over the temperature range 10-90 degrees C.

The partial molar volumes of tripeptides of sequence glycyl-X-glycine, where X is one of the amino acids alanine, leucine, threonine, glutamine, phenylalanine, histidine, cysteine, proline, glutamic acid, and arginine, have been determined in aqueous solution over the temperature range 10-90 degrees C using differential scanning densitometry . These data, together with those reported previously, have been used to derive the partial molar volumes of the side-chains of all 20 amino acids. The side-chain volumes are critically compared with literature values derived using partial molar volumes for alternative model compounds. The new amino acid side-chain volumes, along with that for the backbone glycyl group, were used to calculate the partial specific volumes of several proteins in aqueous solution. The results obtained are compared with those observed experimentally. The new side-chain volumes have also been used to re-determine residue volume changes upon protein folding.

Changes in hand function in the aging adult as determined by the Jebsen Test of Hand Function.

The Jebsen Test of Hand Function is used to assess a broad range of hand functions required for activities of daily living. The time needed to complete a variety of subtests is measured, with high scores indicative of abnormality. Normative values have been established for men and women in two age groups: 20 to 59 years and 60 to 94 years. The purpose of this study was to determine whether hand function, as measured by the Jebsen test, declines with age in subjects over the age of 60 years. A total of 121 men and women were given the test and grouped into the following age categories: (1) 60 to 69 years, (2) 70 to 79 years, and (3) 80 to 89 years. Hand function decreased with age in both men and women. There were significant positive correlations between age and time needed to complete the various subtests, and analyses of variance revealed significant differences between subjects in their 80s and those in their 60s and 70s. In only a few tasks were there significant differences between men and women within any age group. Because of the decrease in normal function with age, measurements obtained with the Jebsen test in the elderly should be compared with normative values that are obtained from similarly aged subjects. [Hackel ME, Wolfe GA, Bang SM, Canfield JS. Changes in hand function in the aging adult as determined by the Jebsen Test of Hand Function.

[Diagnosis and therapy of chronic subdural hematoma]. / Diagnostika a lécba chronického subdurálního hematomu.

The authors evaluate a group of 72 patients with the diagnosis of chronic subdural haematoma (cSDH). All subdural collections were confirmed on a computer tomograph. Sixty-nine patients were operated by trepanation and drainage into a closed system which was maintained for a maximum of five days. Three patients with a hyperdense CT finding were subjected to extended trepanation or craniectomy with membranectomy. The CT picture made on the 2nd-4th day after operation revealed a persisting subdural collection in 35% of the patients subjected to trephination. The authors were concerned with the problem whether this percentage makes trephination with drainage controversial as the only universal therapeutic method in cSDH. Nevertheless successful reinsertion of the drain (85%) is in favour of trephination although drainage from the first trephination in not always the definite solution. Conversely revision by craniotomy was a failure in 7 patients where the drainage method was not successful. Radical surgery proved useful only in the initial period in patients who despite a chronic course had on CT a hyperdense collection. The influence of the site, volume of collection, lateral overpressure and possibly a subsidiary CT finding could not be proved on a statistically significant scale, therefore the authors did not use these CT markers when selecting surgical intervention.

[Anterior cervical corpectomy in the treatment of multilevel degenerative stenoses with spondylotic myelopathy. Personal experience with therapy and a literature review]. / Prední krcní korpektomie pri resení víceetázových degenerativních stenóz se spondylogenní myelopatií. Zkusenosti s lécbou a prehled literatury.

The authors use as a basis experience with a group of 389 patients operated in 1989-1997 on account of degenerative diseases of the cervical spine with neurological manifestations. The results are compared with experience assembled in 1998-1999. In the new group (188 patients with the same diagnosis) the same indication criteria were used but in case of myelopathy associated with multisegmetal cervical stenosis not only multilevel discectomy was performed (as in the previous group) but in addition also 1-3 segmental corpectomy (somatectomy). The results were evaluated separately for both methods used. The authors emphasize the necessity of a radical approach during decompression of neurological structures incl. removal of uncovertebral osteophytes which must be combined with suitable stabilization of the fusions or possibly be supported by instrumentation. In the discussion the authors illustrate in the form of a review the development of anterior cervical corpectomy as one of the methods of an anterior approach to the cervical spine used at first in traumatic and oncological conditions, later extended to operations on account of degenerative, dysplastic conditions and other diseases. The authors wish to help to define criteria for application of corpectomy when treating stenoses of the spinal canal in the cervical region. The indication will be defined in a perspectively followed up group where a detailed clinical and electrophysiological algorithm for examination was submitted as well as postoperative follow-up and processing of the resulting data.

[Surgical treatment of intervertebral disk herniation and spondylosis in degenerative diseases of the thoracic vertebrae--basic approach. Review of the literature and a group of 12 patients]. / Chirurgická lécba výhrezu meziobratlové ploténky a spondylózy u degenerativního onemocnení hrudní pátere--zadní prístup. Prehled literatury a soubor 12 nemocných.

Prolapse of an intervertebral disc and neurologically important spondylosis of the thoracic vertebrae are not a frequent finding--in the wide spectrum of surgical treatment of degenerative diseases of the spine the numbers of operations in the thoracic section account only for a few percent. The authors give an account of 12 patients treated surgically during the 5-year period 1997-2001 at the Neurosurgical Department of the First Medical Faculty Charles University and Institute for Postgraduate Training in Prague-Stresovice. They describe the establishment of the neurological finding from the differential diagnostic aspect, the algorithm of radiological examination and selected treatment. In the group of surgically treated patients were two with spinal and radicular symptoms, 8 patients had only spinal and 2 patients had only root symptoms. Laminectomy was performed in one female patient, in 9 patients discectomy was performed from a transpedicular approach and in two patients discectomy from costotransversectomy. Complete normalization of clinical complaints was recorded in 2 patients, in 8 the condition improved and 2 patients did not improve. In 2 patients a revision was made and extension of the approach on account of persisting clinical complaints, in one patient after revision complete normalization of the clinical finding occurred, the second patient did not improve after revision. Selection and results of the surgical approach--in all instances different types of posterior approach were involved--are discussed. In the discussion also a brief review, indications and illustrations of posterior approaches are given. The discussion deals also with the advantages and disadvantages of the method as compared with the anterior approach or endoscopic technique. The authors emphasize the advantages of the microsurgical technique--the open posterior approach still holds an irreplaceable place in the spectrum of surgical therapeutic methods despite the onset of endoscopic methods.

Serotype prevalence and antibiotic resistance in Streptococcus pneumoniae clinical isolates among global populations.

Streptococcus pneumoniae remains a leading cause of disease in children and adults. Serotypes differ in invasiveness, virulence, and antibiotic resistance; therefore, serotype surveillance is necessary to monitor the burden of pneumococcal disease, especially in the setting of pneumococcal vaccination programs. The Tigecycline Evaluation Surveillance Trial, (TEST), is an on-going global antibiotic susceptibility surveillance program. Serotypes and antibiotic susceptibilities of 2173 invasive S. pneumoniae in this existing database during 2004-2008 were evaluated. Worldwide, serotypes 19A (28%), 19F (10%) and 14 (9%) were the most common in children under 5 years. In adults over 16 years, 19A (13%), 3, 6A and 7F (all 7%) were most common. Serotypes 19A, 6A, 19F, 6B, 15A, 9V, and 14 exhibited significantly higher levels of erythromycin resistance (P<0.05), while 19A, 19F, 35B, 6A, 6B, 23A, 9V, 15A, and 14 demonstrated higher rates of penicillin resistance (P<0.05). This analysis of an existing pathogen database provides a snapshot of global serotype data and describes the consequential issue of antibiotic resistance in specific serotypes, many of which are increasingly common causes of invasive pneumococcal disease.

Susceptibility of European Escherichia coli clinical isolates from intra-abdominal infections, extended-spectrum ß-lactamase occurrence, resistance distribution, and molecular characterization of ertapenem-resistant isolates (SMART 2008-2009).

A total of 3160 clinical isolates of Escherichia coli from intra-abdominal infections were collected during 2008-2009 from 13 European countries. The frequency of extended-spectrum ß-lactamase (ESBL)-producing isolates in Europe was 11%. The most active antibiotics tested were typically imipenem, ertapenem, and amikacin, although the activity of all non-carbapenem antibiotics was lower when tested against ESBL-positive isolates than when tested against ESBL-negative isolates. Ertapenem exhibited 99.3% susceptibility with all isolates, and 96.8% susceptibility with ESBL-positive isolates. With application of the ertapenem CLSI clinical breakpoint for resistance (MIC ≥1 mg/L), only six isolates (0.2%) were ertapenem-resistant, and only three of these were available for molecular characterization. Of those three, only one was ESBL-positive (CTX-M-14), and two were carbapenemase-positive (OXA-48). All three were negative for, VIM, NDM and KPC carbapenemases. Although the level of ertapenem resistance in E. coli is very low, further monitoring of ertapenem susceptibility and molecular characterization of ertapenem-resistant isolates is needed.

Simultaneous cerebral and spinal fluid pressure recordings in surgical indications of the Chiari malformation without myelodysplasia.

Patients with Chiari's malformation without myelodysplasia often suffer from another associated spinal cord lesion--syringomyelia. A condition entirely overriding the clinical picture, affecting adversely the results of surgery as well as the prognosis of this congenital developmental defect. Proceeding from the results of their surgical treatment of 40 patients with hindbrain malformation, the authors recommend, in accordance with the literature, a different approach to and classification of patients depending on the presence of syringomyelia (A/B classification; A: syringomyelia on MR--present, B: absent). The pathological development of the syrinx is caused by obstruction to the natural CSF circulation in the subarachnoid spaces of the craniocervical junction (Williams' dissociation theory). The authors are convinced that routine (static) imaging methods (CT, MR) cannot prove the presence or behaviour of a CSF block, and that they cannot help choose reliably the optimum type of treatment. In contrast, direct measurement (and monitoring) of CSF pressure in different compartments of the CSF pathways (intracranial/intraspinal compartment, i.e., in front of and beyond the suspected block) are a method which can help ascertain with precision the presence and behaviour of a CSF circulatory block, and which also provides dynamic information on such a block during the diurnal rhythm for a period of several days. The authors present the results of a prospective study of 25 patients with hindbrain malformation and describe a technique of parallel monitoring of the two CSF compartments using an adaptation of the Williams method, as well as two different types of dissociation tests designed to prove the presence of a CSF block. CSF flow obstruction was found in 11 patients, in 14 patients it could not be proved. In 8 out of 9 patients with a fully developed syrinx (group A) the block was found as expected. It was, however, diagnosed also in 3 patients until then without any graphic proof of a syrinx (group B). The authors also report on short-term (3-year) results of surgical treatment in patients with rhombencephalic malformation, who had 2 different modes of treatment indicated on the basis of dissociation test results. The advantages and disadvantages are discussed of direct measurement and parallel monitoring of CSF in comparison with radiological methods; emphasis is laid on inevitable radicality in the recanalization of CSF passages in patients with well established CSF blocks.

Chronic subdural haematoma treatment with a rigid endoscope.

Surgical treatment is the method of choice in cases of chronic subdural haematoma--as a rule: trephination, drainage with lavage, or repeated drainage (drain reinsertion where the haematoma has been evacuated insufficiently). A poorly manageable but non-negligible group is made up of patients (about 5-12 % of all cases) where the less invasive methods of choice keep failing. The equally mini-invasive endoscopic technique appears to be one of the suitable therapeutical approaches before resorting to open-surgery revision. The adapted technique of rigid endoscope insertion permitting sufficient revision and treatment of the subdural space concerned is presented. The method is demonstrated on three case reports where routine trephination with lavage, drainage and repeated drain insertion failed. A very good improvement in clinical condition and graphic findings was achieved in two patients. In the remaining one, the neurological lesion improved ad integrum despite a tiny residual haematoma as visualized by CT. Two weeks later, a clinical relapse had developed and the patient was treated with new trephination and drain reinsertion. The technical aspects of the modification of the endoscopic technique are discussed: stressing the advantages or low-degree invasiveness, scope for keeping intact the inner membrane of the haematoma and avoiding direct invasion of the cerebral tissue. The limits of the method are discussed as well. The authors regard this method as a useful addition to the surgical armamentarium, especially in cases of chronic subdural haematomas resisting conventional approaches.

Identification, cloning, and sequencing of piv, a new gene involved in inverting the pilin genes of Moraxella lacunata.

Moraxella lacunata is a bacterium that is a causative agent of human conjunctivitis and keratitis. We have previously cloned the Q and I pilin (formerly called beta and alpha pilin) genes of Moraxella bovis and determined that an inversion of 2 kilobases (kb) of DNA determines which pilin gene is expressed. Using an M. bovis pilin gene as a hybridization probe to screen a lambda ZAP library of M. lacunata DNA, we have isolated a clone that not only contains the entire type 4 pilin gene inversion region of M. lacunata but inverts the 2-kb region on a plasmid subclone (pMxL1) in Escherichia coli. Deletion derivatives of pMxL1 yielded some plasmids that still had the entire inversion region but were phase locked into one or the other of the two potential orientations. Similarly, insertions of a 2-kb streptomycin-resistant element (omega) within some regions outside of the inversion also resulted in phase-locked plasmids. These deletions and insertions thus localize a probable invertase necessary for the inversion event. The region was sequenced, and an open reading frame with over 98% DNA sequence homology to an open reading frame that we previously found in M. bovis and called ORF2 appeared to be a strong candidate for the invertase. This conclusion was confirmed when a plasmid containing the M. bovis ORF2 supplied, in trans, the inversion function missing from one of the M. lacunata phase-locked inversion mutants. We have named these putative invertase genes piv(ml) (pilin inversion of M. lacunata) and piv(mb) (pilin inversion of M. bovis). Despite previously noted sequence similarities between the M. bovis sites of inversion and those of the Hin family of invertible segments and a 60-base-pair region within the inversion with 50% sequence similarity to the cin recombinational enhancer, there is no significant sequence similarity of the Piv invertases to the Hin family of invertases.