Impact of mutations in hVISA isolates on decreased susceptibility to vancomycin, through population analyses profile - area under curve (PAP-AUC).

We analyzed sequences of graSR, vraSR, walKR and rpoB genes in hVISA from Brazil. Five isolates showed mutations in at least one gene. rpoB H481N and graS T224I were the most frequent mutations, followed by graR D148Q and walK A468T. Our study reinforces the heterogeneity of genetic patterns among hVISA.

Development of serological proteome analysis of mastitis by Staphylococcus aureus in ewes.

Staphylococcus aureus is a major agent of mastitis in ruminants worldwide. So far, efficient measures for its prophylaxis (including vaccination) have proven to be unsuccessful and there is a need for a better understanding of the host response to udder infection by S. aureus. Serological proteome analysis (SERPA) is a promising technique that can be used to identify S. aureus immuno-dominant determinants providing that bacterial culture conditions used to grow S. aureus strains for protein sample preparation mimic the context of mastitis. A S. aureus strain was used in experimental mastitis to generate sheep serum used to determine the best growth conditions for SERPA. Sera collected in the field from different ewes suffering from mastitis by S. aureus were used to confirm experimental observations. Three different culture media (BHI, whey and iron-depleted RPMI) were tested. The influence of aeration and growth phase on protein production was also evaluated by immuno-detection of protein samples prepared from cultures grown in different conditions and obtained from different culture fractions (supernatant, cell wall, and total lysates). Our results showed that culturing in iron-depleted RPMI with (secreted proteins, prepared from stationary phase) or without aeration (cell wall proteins, prepared from early stationary phase, and total proteins, prepared from exponential phase) is the condition that best mimics growth in vivo during mastitis and this in vitro growth condition is to be used henceforth in experiments involving SERPA.

Molecular characterisation of Staphylococcus aureus strains isolated from small and large ruminants reveals a host rather than tissue specificity.

Staphylococcus aureus is an important pathogen in domestic ruminants. The main objective of this study was to determine the similarity of epidemiologically unrelated S. aureus isolates from bovine, ovine, and caprine hosts regardless the locus of isolation (nares and udder). By pulsed-field gel electrophoresis, seven major pulsotypes were identified among 153 isolates recovered from 12 different regions of France as well as from Brazil, the USA and Belgium. Typing of the accessory gene regulator (agr) and capsular (cap) serotype was carried out on all the isolates and revealed the predominance of agr I and III and of cap8 regardless the ruminant host species. Screening for methicilin-resistant S. aureus (MRSA) was carried out by disk diffusion and revealed a prevalence of only 3.2% of MRSA among the strains tested. These results suggest the existence of a host rather than tissue specificity among S. aureus isolates colonising the ruminant species and suggest a limited transmission of those isolates between large (bovine) and small (ovine-caprine) ruminants. The agr class and cap types correlated with pulsotype clusters rather than with a specific host species. Antimicrobial resistance appears not to have contributed to the predominance of any given genotypes, and MRSA prevalence appears very low in ruminant isolates.

Molecular techniques for MRSA typing: current issues and perspectives.

Staphylococcus aureus has long been recognised as an important pathogen in human disease. Serious staphylococcal infections can frequently occur in inpatients and may lead to dire consequences, especially for therapy with antimicrobial agents. The increase in the frequency of Methicillin-Resistant Staphylococcus aureus (MRSA) as the causal agent of nosocomial infection and the possibility of emergence of resistance to vancomycin demands a quick and trustworthy characterization of isolates and identification of clonal spread within hospitals. Enough information must be generated to permit the implementation of appropriate measures for control of infection, so that outbreaks can be contained. Molecular typing techniques reviewed in this manuscript include: plasmid profile analysis, analysis of chromosomal DNA after enzymatic restriction, Southern blotting, pulsed field gel electrophoresis (PFGE), techniques involving polymerase chain reaction and multilocus sequence typing (MLST). Repetitive DNA Sequence PCR (rep-PCR) may be used for screening due to its practicality, low cost and reproducibility. Because of its high discriminatory power Pulsed-Field Gel Electrophoresis (PFGE) still remains the gold standard for MRSA typing. New techniques with higher reproducibility and discriminatory power, such as Multi-Locus Sequence Typing (MLST), are appearing. These are mostly useful for global epidemiology studies. Molecular typing techniques are invaluable tools for the assessment of putative MRSA outbreaks and so should be extensively used for this purpose.

Molecular techniques for MRSA typing: current issues and perspectives

Staphylococcus aureus has long been recognised as an important pathogen in human disease. Serious staphylococcal infections can frequently occur in inpatients and may lead to dire consequences, especially as to therapy with antimicrobial agents. The increase in the frequency of Methicillin-Resistant Staphylococcus aureus (MRSA) as the causal agent of nosocomial infection and the possibility of emergence of resistance to vancomycin demands a quick and trustworthy characterization of isolates and identification of clonal spread within hospitals. Enough information must be generated to permit the implementation of appropriate measures for control of infection, so that outbreaks can be contained. Molecular typing techniques reviewed in this manuscript include: plasmid profile analysis, analysis of chromosomal DNA after enzymatic restriction, Southern blotting, pulsed field gel electrophoresis (PFGE), techniques involving polymerase chain reaction and multilocus sequence typing (MLST). Repetitive DNA Sequence PCR (rep-PCR) may be used for screening due to its practicality, low cost and reproducibility. Because of its high discriminatory power Pulsed-Field Gel Electrophoresis (PFGE) still remains the gold standard for MRSA typing. New techniques with higher reproducibility and discriminatory power, such as Multi-Locus Sequence Typing (MLST), are appearing. These are mostly useful for global epidemiology studies. Molecular typing techniques are invaluable tools for the assessment of putative MRSA outbreaks and so should be extensively used for this purpose

Microdecompression for lumbar spinal canal stenosis.

STUDY DESIGN: A description of the technique for lumbar microdecompression and a prospective study of the outcomes. OBJECTIVE: To describe and analyze a technique that affords an excellent decompression while minimizing damage to surrounding tissues. SUMMARY OF BACKGROUND DATA: Commonly used techniques of lumbar decompression that include bilateral takedown of paraspinal musculature and aggressive bony resection can result in significant iatrogenic sequelae. A less destructive alternative is needed. METHODS: Unilateral limited takedown of multifidus was undertaken, and ipsilateral decompression performed. The contralateral side then was addressed under the midline structures with microscopic visualization--thereby preserving the supra-/interspinous ligament complex and the contralateral musculature. Thirty consecutive patients undergoing the procedure were analyzed prospectively and after a follow-up period by independent observers using a modified validated functional outcome score and patient satisfaction measures. RESULTS: The technique affords an excellent decompression while minimizing destruction to tissues not directly involved in the pathologic process. Functional outcome scores doubled, and 87% of patients reported high satisfaction rates. CONCLUSIONS: Lumbar microdecompression is a minimally invasive technique that appears to provide excellent functional outcomes.

Uninstrumented posterolateral lumbar fusion for single level isolated disc resorption and/or degenerative disc disease.

The limited soft-tissue envelope technique for an uninstrumented single-level posterolateral lumbar fusion has been studied in a group of 23 patients. It resulted in a solid fusion in 21 of 23 (91%) patients. Overall, 18 of 23 (78%) patients had a satisfactory outcome to this fusion technique, which can be performed in any community-based hospital.

Microdecompression and uninstrumented single-level fusion for spinal canal stenosis with degenerative spondylolisthesis.

STUDY DESIGN: A retrospective review was completed on 21 patients who had a "least invasive" (one or two level) microdecompression and uninstrumented single-segment lumbar fusion for spinal canal stenosis with degenerative spondylolisthesis. OBJECTIVE: To determine whether a "least invasive" approach to lumbar spinal canal stenosis and degenerative spondylolisthesis would yield acceptable results. SUMMARY OF BACKGROUND DATA: The prevailing surgical technique for symptomatic spinal canal stenosis with degenerative spondylolisthesis is a wide midline decompression and instrumented fusion. METHODS: On an average of 38 months postoperatively, 21 patients were personally assessed on four scores: 1) their overall satisfaction with the outcome of surgery, 2) an analog back and leg pain scale, 3) a functional evaluation scale, and 4) Ferguson (upshot) anterior-posterior lumbosacral and lateral flexion-extension radiographs. RESULTS: The overall satisfactory outcome on all four scales was 16 (76%) of 21. Twenty of twenty-one patients had relief of their claudicant leg pain; the overall fusion rate was 18 (86%) of 21. Two of three patients with a pseudarthrosis had a successful outcome on the patient-oriented outcome (1, 2, and 3) scales (excluding the radiograph scale), and one was a failure. One patient with a solid fusion was a failure because of continuing back pain. One patient with a solid fusion was a failure because of continuing leg pain. The overall satisfactory outcome on the nonradiographic scales was 18 of 21, for an 86% patient satisfaction rate. CONCLUSIONS: In this retrospective study, a "least invasive" surgical approach to lumbar degenerative spondylolisthesis with spinal canal stenosis causing claudicant leg pain produced acceptable results.

A system for reporting the size and location of lesions in the spine.

STUDY DESIGN: A description of a method for standardizing the nomenclature used in reporting the size and location of lesions in the lumbar or thoracic spine is presented. OBJECTIVES: To make the reporting of findings on computed tomography or magnetic resonance imaging scans simpler and more accurate. SUMMARY OF BACKGROUND DATA: Over the past 10 years, three other systems have been proposed, and parts of each have been incorporated in this system. METHODS: This is a multicenter report. A group of 12 prominent physicians, including radiologists, neurosurgeons, orthopedic surgeons, and physiatrists, at 11 centers collaborated in the formulation of this system. RESULTS: In this system, areas in the axial plane, i.e., medial to lateral, are called "zones," and in the caudocranial direction, they are called "levels." The zones are the central canal zone, the subarticular zone, the foraminal zone, and the extraforaminal zone. In the caudocranial direction, the levels from above downward are the suprapedicle level, the pedicle level, the infrapedicle level, and the disc level. The size of a lesion can be rated by the descriptive words normal, mild, moderate, moderately severe, and severe, or by the numbers 1 to 5, with the number 1 indicating normal and the number 5 indicating severe. CONCLUSIONS: The authors of the present study believe that all health care professionals who care for the spine will find this nomenclature valuable in communicating with each other, in writing medical reports, in presenting reports at meetings, or in writing scientific articles.

Focus issue on lumbar disc herniation: macro- and microdiscectomy.

This paper is based on a review, analysis, and discussion of the extensive literature on indications, technique, and complications of discectomy (macro and micro) for lumbar disc herniation. Outcomes for lumbar discectomy for disc herniation depend on patient selection. Short-term results of discectomy are excellent when there is agreement between the clinical presentation and imaging studies. Long-term results of surgery are only slightly better than conservative measures and the natural history of a lumbar disc herniation. A review of the literature reveals success rates for lumbar discectomy ranging from 80-96%. The outcome of lumbar discectomy does not appear to be affected by the use of a microscope and depends more on patient selection than on surgical technique.

Consensus summary of the diagnosis and treatment of lumbar disc herniation.

Clinicians must not simply decide that a patient with symptoms and a positive diagnostic test has a reason for a specific treatment, and likewise clinicians must not decide that a patient with symptoms and a negative test does not have a clinically important problem. We must also consider the sensitivity, specificity and predictive value of the diagnostic test and the individual characteristics of the patient. Treatment outcome depends on many factors. Point of service decisions vs population based decisions are obviously different. Each patient presents to the treating practitioner on a given day, at a given time, and it is this picture upon which a plan of care is formulated.

Microdecompression without fusion for radiculopathy associated with lytic spondylolisthesis.

Patients with symptomatic L-5 nerve root compression and associated lytic spondylolisthesis are commonly treated by bilateral wide posterior decompression and concomitant fusion, often accompanied by transpedicular instrumentation. More limited surgery aimed solely at the relief of nerve root compression offers the potential for significant relief of radicular pain while avoiding iatrogenic instability, thereby alleviating the need for arthrodesis with its increased surgical morbidity. Nine patients with unilateral radicular symptoms referable to the L-5 nerve root, minimal back pain, and a lytic pars lesion with mild spondylolisthesis underwent unilateral microdecompression on their symptomatic side without associated fusion. All patients obtained relief of radicular pain at both short- and long-term follow-up examination. One patient demonstrated increased back pain and, accordingly, the procedure is now recommended only for patients with no greater than a 25% spondylolisthesis. Unilateral microdecompression without stabilization is an effective and safe method for relieving radicular pain in patients with a lytic pars defect, a mild spondylolisthesis, and minimal back pain. This therapeutic option should be considered in select cases as an alternative to bilateral wide decompression with fusion and instrumentation.

Chymopapain versus conventional surgery for lumbar disc herniation. 10-year results of treatment.

We reviewed two comparable groups of patients who had been treated for lumbar disc herniation by chymopapain chemonucleolysis (145) or conventional surgical discectomy (91). They were reviewed 10 years after treatment by questionnaire, followed by a personal interview by an independent observer. The results of the surgically treated groups were slightly better than those treated with chymopapain. In particular, there was significantly better early relief of leg and low back pain, and fewer patients needed a second procedure. Complications were few in both groups.

Automated percutaneous diskectomy: initial patient experience. Work in progress.

A new method has been developed for percutaneously decompressing herniated lumbar disks. The method entails gaining access to the disk space through the use of an introduction system and a cannula. A 2-mm aspiration probe called a Nucleotome is then placed through the cannula into the disk space, and the nucleus pulposus is aspirated. Thirty-six patients have undergone the procedure, with a successful result in 31. There were no significant complications encountered, and the procedure is now being done on an outpatient basis. These preliminary results indicate that automated percutaneous diskectomy has the potential to replace laminectomy in the treatment of uncomplicated herniated disks.