Remission after treatment of osteoarticular infections due to Pseudomonas aeruginosa versus Staphylococcus aureus: a case-controlled study

Purpose: Osteoarticular infections due to methicillin-susceptible Staphylococcus aureus (MSSA) or its methicillin-resistant variant (MRSA) are feared due to treatment failures. According to clinical experience, Pseudomonas aeruginosa may reveal less long-term remission than S. aureus. Methods: A case-controlled study comparing outcomes of osteoarticular infections due to P. aeruginosa vs S. aureus was performed at Geneva University Hospitals. Results: A total of 111 S. aureus (including 37 MRSA) and 20 P. aeruginosa osteoarticular infections were analysed in 131 patients: arthroplasties (n = 38), fracture fixation devices (n = 56), native joint arthritis (n = 7) and osteomyelitis without implant (n = 30). The median active follow-up time was 4years. The patients underwent a median number of two surgical interventions for P. aeruginosa infections compared to two for S. aureus (two for MRSA), while the median duration of antibiotic treatment was 87days for P. aeruginosa and 46days for S. aureus infections (58days for MRSA) (all p > 0.05). Overall, Pseudomonas-infected patients tended towards a lower remission rate than those infected with S. aureus (12/20 vs 88/111; p = 0.06). This was similar when P. aeruginosa was compared with MRSA alone (12/20 vs 30/37; p = 0.08). In multivariate logistic regression analyses adjusting for case mix, odds ratios (OR) for remission were as follows: P. aeruginosa vs S. aureus [OR 0.4, 95% confidence interval (CI) 0.1-1.2], number of surgical interventions (OR 0.6, 95% CI 0.5-1.0) and duration of antibiotic treatment (OR 1.0, 95% CI 1.0-1.0). Conclusions: Despite a similar number of surgical interventions and longer antibiotic treatment, osteoarticular infections due to P. aeruginosa tended towards a lower remission rate than infections due to S. aureus in general or MRSA in particula

The CYP7A1 gene rs3808607 variant is associated with susceptibility of tuberculosis in Moroccan population

Introduction: Despite the medical progress in treatment. Tuberculosis (TB) continues to be a serious global health problem. A genome-wide linkage study identified a major susceptibility locus on  chromosomal region 8q12-q13 in Moroccan TB patients. The CYP7A1 gene is located in this region and codes for cholesterol 7a-hydroxylase, an enzyme involved in cholesterol catabolism. Methods: We selected three SNPs (rs3808607, rs8192875 and rs8192879) and studied their genotype and allele frequencies distribution in patients with pulmonary (PTB) or pleural TB (pTB), and compared them to Healthy Controls (HC). Genotyping of rs8192875 and rs8192879 SNPs was carried out using the Taq Man SNP genotyping Assay while rs3808607 was investigated by PCR-RFLP.Results: We reported here for the first time a statistically significant increase in the AA homozygote genotype frequency of rs3808607 in PTB patients compared to HC (p = 0.02, OR = 1.93, 95% CI: 1.93 (1.07;3.49). The increased risk of developing TB was maintained when we combined the groups of patients (PTB-pTB) (p = 0.01, OR= 1.91, 95% CI = (1.07 - 3.42). In contrast, no genetic association was observed between the rs8192875 or rs8192879 polymorphisms and TB. Conclusion: Our investigations suggest that rs3808607 may play a role in susceptibility to TB in a Moroccan population.Key words: Tuberculosis, cholesterol 7-alpha-hydroxylase, polymorphisms, SNPs, cholestero

Osteochondroma of the First Phalanx in Tbourida Horses

This study aimed at describing anatomo-histopathological and imaging features, using computed tomography and magnetic resonance imaging on six ex vivo forelimbs of Tbourida horses, that presented a particular bone exostosis on the dorsal and proximal part of the first phalanx, diagnosed by X-ray. Gross anatomy of the bone exostosis revealed an irregular surface with poly-lobulated tissue masses showing a cauliflower shape. The diameter/depth varied from 0.5 to 5.1 cm with a mean of 3.9 ± 0.9 cm. The capsule of the metacarpophalangeal joint was hypertrophic and showed many invaginations in the inner part, in contact with the bone exostosis. Computed tomography revealed cortical and medullary continuity of the bone exostosis, with the underlying bone, and remodeling of the cortical surface of the dorsal and proximal part of the first phalanx. Magnetic resonance imaging showed an increased signal intensity of the bone exostosis on the T1- and T2*-weighted gradient fast echo. Histological examination of the bone exostosis revealed a cap of hyaline cartilage, including large foci of endochondral ossification with a base of cancellous bone surrounding marrow spaces, which confirmed the diagnosis of osteochondroma. The capsule of the metacarpophalangeal joint showed a large amount of recently formed connective tissue fibers in its inner part, interspersed with mature connective tissue. The hyperextension of the metacarpophalangeal joint during a Tbourida show, which occurs on a hard ground surface, and the use of hobbles in horse stabling are most likely responsible for the outgrowth of an osteochondroma of different shapes and sizes, and fracture complications in some cases

Gram and acridine orange staining for diagnosis of septic arthritis in different patient populations

Purpose: The sensitivity of Gram staining is known to be suboptimal for the diagnosis of native joint septic arthritis. We lack information about the accuracy of Gram compared to other microscopic staining techniques for predicting infection in different patient populations. Methods: This was a cohort study with cost evaluations at the Orthopaedic Service of Geneva University Hospitals (January 1996-October 2012). Results: Among 500 episodes of arthritis (196 with immunosuppression, 227 with underlying arthroplasties and 69 with gout or other crystals in synovial fluid), Gram staining revealed pathogens in 146 episodes (146/500, 29%) or in 146 of the 400 culture-positive episodes (37%). Correlation between the Gram and acridine staining of the same sample was good (Spearman 0.85). Overall, the sensitivity, specificity, positive predictive value and negative predictive value of Gram stain for rapid diagnosis of septic arthritis was 0.37, 0.99, 0.99 and 0.28, respectively, compared to microbiological cultures. Quite similar values were recorded across the different patient subpopulations, in particular for sensitivity values that were 0.33 for patients with prosthetic joint infections, 0.40 for immunosuppressed patients, 0.36 for patients under antibiotic administration and 0.52 for patients with concomitant crystalline disease. Conclusions: The sensitivity of Gram or acridine orange staining for a rapid diagnosis of episodes of septic arthritis is suboptimal compared to microbiological culture, regardless of underlying conditions, immunosuppression or antibiotic therapy. The sensitivity in the presence of synovial fluid crystals is moderate. Acridine orange and Gram stains are equivalent

Gram and acridine orange staining for diagnosis of septic arthritis in different patient populations

The sensitivity of Gram staining is known to be suboptimal for the diagnosis of native joint septic arthritis. We lack information about the accuracy of Gram compared to other microscopic staining techniques for predicting infection in different patient populations

COMPARISON OF A DNA BASED PCR APPROACH WITH CONVENTIONAL METHODS FOR THE DETECTION OF MYCOBACTERIUM TUBERCULOSIS IN MOROCCO

<p><strong>Background:</strong> Worldwide, tuberculosis (TB) is a major public health problem and the rapid diagnosis and appropriate chemotherapy become the first priority and a serious challenge to improve TB treatment.</p><p>In the objective of early TB diagnosis and rapid detection of <em>Mycobacterium tuberculosis </em>(MTB) in the clinical specimens, the utility of the Polymerase Chain Reaction (PCR) using the Insertion Sequence 6110 (IS6110) as target was compared to conventional methods.</p><p><strong>Methods:</strong> Out of 305 patients with different clinical manifestations: suspected, new, drug relapse, drug failure and chronic cases were enrolled in this study and tested by mycobacteriological and PCR techniques for the investigation about the tubercle bacilli.</p><p><strong>Results:</strong> The results of the in house IS6110 PCR showed a good sensitivity (92, 42%) and high specificity (98%), the positive and negative predictive values were 96.4 % and 95.3 % respectively.</p><p><strong>Conclusion:</strong> This study showed clearly that the PCR testing using the IS6110 in the routine analysis is a potential tool for the rapid TB diagnosis, especially for critical cases and would be of great interest to help the clinician in the misdiagnosed critical cases by the traditional radiology.</p&gt

Molecular Typing of Mycobacterium Tuberculosis Complex by 24-Locus Based MIRU-VNTR Typing in Conjunction with Spoligotyping to Assess Genetic Diversity of Strains Circulating in Morocco.

Standard 24-locus Mycobacterial Interspersed Repetitive Unit Variable Number Tandem Repeat (MIRU-VNTR) typing allows to get an improved resolution power for tracing TB transmission and predicting different strain (sub) lineages in a community.During 2010-2012, a total of 168 Mycobacterium tuberculosis Complex (MTBC) isolates were collected by cluster sampling from 10 different Moroccan cities, and centralized by the National Reference Laboratory of Tuberculosis over the study period. All isolates were genotyped using spoligotyping, and a subset of 75 was genotyped using 24-locus based MIRU-VNTR typing, followed by first line drug susceptibility testing. Corresponding strain lineages were predicted using MIRU-VNTRplus database.Spoligotyping resulted in 137 isolates in 18 clusters (2-50 isolates per cluster: clustering rate of 81.54%) corresponding to a SIT number in the SITVIT database, while 31(18.45%) patterns were unique of which 10 were labelled as "unknown" according to the same database. The most prevalent spoligotype family was LAM; (n = 81 or 48.24% of isolates, dominated by SIT42, n = 49), followed by Haarlem (23.80%), T superfamily (15.47%), >Beijing (2.97%), > U clade (2.38%) and S clade (1.19%). Subsequent 24-Locus MIRU-VNTR typing identified 64 unique types and 11 isolates in 5 clusters (2 to 3isolates per cluster), substantially reducing clusters defined by spoligotyping only. The single cluster of three isolates corresponded to two previously treated MDR-TB cases and one new MDR-TB case known to be contact a same index case and belonging to a same family, albeit residing in 3 different administrative regions. MIRU-VNTR loci 4052, 802, 2996, 2163b, 3690, 1955, 424, 2531, 2401 and 960 were highly discriminative in our setting (HGDI >0.6).24-locus MIRU-VNTR typing can substantially improve the resolution of large clusters initially defined by spoligotyping alone and predominating in Morocco, and could therefore be used to better study tuberculosis transmission in a population-based, multi-year sample context

Detailed Results obtained including demographic, drug-resistance and genotyping information on 5 Clusters and 69 unique patterns defined by identical spoligotyping and 24-loci MIRU from 75 <i>M</i>.<i>tuberculosis</i> strain isolated in Morocco.

<p>ID: Identifying number</p><p>DST: Drug SusceptibilityTesting</p><p>MLVA-MtbC15-9: Multi Locus Variant Allele-Mycobacterium tuberculosis complex15-9</p><p>Detailed Results obtained including demographic, drug-resistance and genotyping information on 5 Clusters and 69 unique patterns defined by identical spoligotyping and 24-loci MIRU from 75 <i>M</i>.<i>tuberculosis</i> strain isolated in Morocco.</p