Combined effects of soil 3D spatial heterogeneity and biotic spatial heterogeneity (plant clumping) on ecosystem processes in grasslands.

Soil heterogeneity has been shown to enhance plant diversity, but its effect on grassland productivity is less clear. Even less is known about the effect of plant clumping (intraspecific aggregation) and its potential interaction with soil heterogeneity. The combined effects of soil 3D spatial heterogeneity and species clumping were experimentally studied in grassland mesocosms consisting of four grassland species. These species were planted in three patterns (i.e. completely mixed, clumped by 9 or 36 individuals of the same species) on soils with heterogeneous cells of alternating nutrient-poor and rich soil differing in size from 0 (mixed soil) to 12, 24, and 48 cm (complete poor or rich mesocosm). Moderate soil cell sizes (12-24 cm) consistently increased whole-mesocosm aboveground productivity by more than 20%, which mainly originated from the increased growth of the plants growing on the poor soil cells. In contrast, total mesocosm productivity was not affected by species clumping although there were some species-specific effects, both of clumping and of the interaction of clumping with soil heterogeneity. Our results show that intermediate soil heterogeneity promotes productivity. Clumping can improve the growth of inferior species, thus promoting coexistence, without affecting overall productivity. We found no interaction effect of clumping and soil heterogeneity on productivity at the community level and some minor species-specific effects.

Characterisation of Staphylococcus aureus isolates from bloodstream infections, Democratic Republic of the Congo.

Staphylococcus aureus is known worldwide as an invasive pathogen, but information on S. aureus from bloodstream infections in Central Africa remains scarce. A collection of S. aureus blood culture isolates recovered from hospitals in four provinces in the Democratic Republic of the Congo (2009-2013) was assessed. A total of 27/108 isolates were methicillin-resistant S. aureus (MRSA), of which >70% were co-resistant to aminoglycosides, tetracyclines, macrolides and lincosamides. For MRSA and methicillin-susceptible S. aureus (MSSA) isolates, resistance to chloramphenicol and trimethoprim-sulphamethoxazole (TMP-SMX) was <10%. However, 66.7% (72/108) of all isolates harboured the trimethoprim resistance gene dfrG. More than three-quarters (84/108, 77.8%) of isolates belonged to CC5, CC8, CC121 or CC152. Genetic diversity was higher among MSSA (31 spa types) compared to MRSA (four spa types). Most MRSA (23/27, 85.2%) belonged to CC8-spa t1476-SCCmec V and 17/23 (73.9%) MRSA ST8 were oxacillin susceptible but cefoxitin resistant. Among MRSA and MSSA combined, 49.1% (53/108) and 19.4% (21/108) contained the genes encoding for Panton-Valentine leucocidin (lukS-lukF PV, PVL) and toxic shock syndrome toxin-1 (tst, TSST-1), respectively. PVL was mainly detected among MSSA (51/53 isolates harbouring PVL were MSSA, 96.2%) and associated with CC121, CC152, CC1 and CC5. TSST-1 was associated with CC8-spa t1476-SCCmec V. The immune evasion cluster (IEC) genes scn, sak and chp were detected in 81.5% of isolates (88/108, equally represented among MSSA and MRSA). The present study confirms the occurrence of MRSA with high levels of multidrug co-resistance and PVL-positive MSSA among invasive S. aureus isolates in Central Africa.

Staphylococcus aureus nasal carriage among healthcare workers in Kisangani, the Democratic Republic of the Congo.

Methicillin-resistant Staphylococcus aureus (MRSA) is a global health concern, but there are few data from Central Africa. The objective of our study was to characterise S. aureus colonisation isolates from healthcare-exposed professionals in the Democratic Republic of the Congo (DRC). Healthcare workers and medical students (n = 380) in Kisangani, DRC were screened for S. aureus nasal carriage in a single-centre cross-sectional study in the University Hospital of Kisangani. The isolates were identified and characterised using phenotypic and genotypic methods. The nasal carriage rate of S. aureus was 16.6 % and 10 out of 63 isolates (15.9 %) were MRSA. We found 28 different spa types. Most MRSA isolates belonged to ST8-spa t1476-SCCmec V. The majority of MRSA were multidrug-resistant to non-beta-lactam antibiotics. Overall, 28.5 % of S. aureus carried Panton-Valentine leucocidin (PVL)-encoding genes (all methicillin-sensitive) and 17.5 % carried toxic shock syndrome toxin-1 (TSST-1)-encoding genes. The finding of MRSA carriage among healthcare workers in a setting with limited access to diagnostic microbiology and appropriate therapy calls for improved education on infection control practices and supports the introduction of surveillance programmes.

Epidemic increase in Salmonella bloodstream infection in children, Bwamanda, the Democratic Republic of Congo.

Salmonella enterica is the leading cause of bloodstream infection in children in sub-Saharan Africa, but few data are available from Central-Africa. We documented during the period November 2011 to May 2012 an epidemic increase in invasive Salmonella bloodstream infections in HGR Bwamanda, a referral hospital in Equateur Province, DR Congo. Salmonella spp. represented 90.4 % (103 out of 114) of clinically significant blood culture isolates and comprised Salmonella Typhimurium (54.4 %, 56 out of 103), Salmonella Enteritidis (28.2 %, 29 out of 103) and Salmonella Typhi (17.5 %, 18 out of 103), with Salmonella Enteritidis accounting for most of the increase. Most (82 out of 103, 79.6 %) isolates were obtained from children < 5 years old. Median ages of patients infected with Salmonella Typhimurium and Salmonella Enteritidis were 14 months (14 days to 64 years) and 19 months (3 months to 8 years) respectively. Clinical presentation was non-specific; the in-hospital case fatality rate was 11.1 %. More than two thirds (69.7 %, 53 out of 76) of children < 5 years for whom laboratory data were available had Plasmodium falciparum infection. Most (83/85, 97.6 %) non-typhoid Salmonella isolates as well as 6/18 (33.3 %) Salmonella Typhi isolates were multidrug resistant (i.e. resistant to the first-line oral antibiotics amoxicillin, trimethoprim-sulfamethoxazole and chloramphenicol), one (1.0 %) Salmonella Typhimurium had decreased ciprofloxacin susceptibility owing to a point mutation in the gyrA gene (Gly81Cys). Multilocus variable-number tandem-repeat (MLVA) analysis of the Salmonella Enteritidis isolates revealed closely related patterns comprising three major and four minor profiles, with differences limited to one out of five loci. These data show an epidemic increase in clonally related multidrug-resistant Salmonella bloodstream infection in children in DR Congo.

Presence of extended-spectrum beta-lactamase-producing Enterobacteriaceae in waste waters, Kinshasa, the Democratic Republic of the Congo.

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are a major public health concern. We previously demonstrated the presence of ESBL-producing Enterobacteriaceae in sachet-packaged water bags sold in Kinshasa, the Democratic Republic of the Congo. In complement to the previous study, we aimed to assess the presence of ESBL-producing Enterobacteriaceae in waste waters in Kinshasa.Enterobacteriaceae isolates recovered from environmental water samples were screened and phenotypically confirmed as ESBL-producers by disk diffusion according to Clinical and Laboratory Standards Institute (CLSI) guidelines (CLSI M100-S21). Final identification to the species level and further antimicrobial susceptibility testing were carried out with MicroScan® NBC42 panels and the identification of bla (ESBL) coding genes was performed by a commercial multiplex ligation polymerase chain reaction (PCR) microarray (Check-Points CT 101, Wageningen, the Netherlands). Overall, 194 non-duplicate Enterobacteriaceae were recovered from several sewer and river sites in nine out of 24 municipalities of Kinshasa. Fourteen isolates (7.4 %) were confirmed as ESBL-producers, the main species being Enterobacter cloacae (46.6 %) and Klebsiella pneumoniae (40.0 %). Associated resistance to both aminoglycoside and fluoroquinolone antibiotics was observed in ten isolates; the remaining isolates showed co-resistance to either fluoroquinolone (n = 3) or to aminoglycoside (n = 1) alone. All but one isolate carried bla (CTX-M) genes belonging to the CTX-M-1 group. ESBL-producing Enterobacteriaceae are increasingly being reported from various sources in the community. The present results suggest that ESBL-producing Enterobacteriaceae are widespread in the environment in the community of Kinshasa. Cities in Central Africa should be added to the map of potentially ESBL-contaminated environments and highlight the need to reinforce safe water supply and public sanitation.

[Tietze's syndrome in a 2-year old boy]. / Het syndroom van tietze bij een 2-jarige jongen.

A 2-year-old boy was seen with a painful swelling of the left costochondral junction. Laboratory examination revealed no signs of infection. Echography and CT-scan revealed swelling of the 4th and 5th costochondral junction and the pectoral muscle. Tietze's syndrome was suspected and a wait-and-see policy was decided on. During follow-up, the symptoms gradually decreased. Ten weeks after the onset of symptoms there was only a slight, painless swelling with normal ultrasound findings. Tietze's syndrome is defined as a benign, painful, non-suppurative and localised swelling of the costosternal, costochondral or sternoclavicular joints with spontaneous regression of symptoms. It is typically described in adults but appears in children and infants as well. Recognition of this syndrome and knowledge of its favourable outcome can prevent invasive diagnostic procedures.

Flexion-type supracondylar elbow fractures in children.

SUMMARY: Flexion-type supracondylar elbow fractures are uncommon in children. Minimally displaced fractures were treated in plaster cast in 7 children, and 22 children with a displaced fracture were treated by closed reduction and percutaneous pinning. Results after an average follow-up of 6.3 years showed that the treatment of choice yielded excellent or good results in 86.2% of the patients. All patients were satisfied with the end result and had normal use of their elbow.

Fractures and nonunions of the carpal scaphoid in children.

Fractures of the carpal scaphoid in children show some quite remarkable differences with respect to fractures of the carpal scaphoid in adults. A review of the literature shows that fractures in children are more often located in the distal third, are more often incomplete and are usually not displaced. Our experience with 23 fresh fractures of the carpal scaphoid in children confirms these findings of the literature. Nonunion of the carpal scaphoid is exceedingly rare in children. When reviewing the literature we could find only 29 published cases of nonunion of the carpal scaphoid in children. In most articles describing carpal scaphoid nonunion in children, bone grafting is recommended as the treatment of choice. We report two children with a nonunion of the carpal scaphoid treated successfully by cast immobilization. Therefore, we propose that a child with a nonunion of the carpal scaphoid bone that has never been immobilized previously should be treated by cast immobilization. Surgery should be considered only if there is no indication of healing after 3 months of immobilization.

Treatment of chronic isolated radial head dislocation in children.

Four children had an operative reduction without annular ligament reconstruction for chronic acquired isolated dislocation of the radial head: one girl and three boys with an average age of 7.1 years (range, 4-8.5 years). History indicated that all children had sustained an injury. Results, with an average followup of 50.7 months, were assessed clinically and radiographically. All patients had excellent postoperative functional and radiographic outcomes. Measurements of range of motion of the elbow revealed improved motion in all patients. Reconstruction of the annular ligament seems unnecessary and, therefore, it is suggested that an unreduced radial head dislocation can be treated by simple open reduction and fixation for 6 weeks with a transarticular pin.

Fractures of the capitellum humeri in adolescents.

Six children between 11 and 15 years old with a displaced fracture of the capitellum were treated by open reduction and fixation with one small screw. In all cases union occurred. There were no complications and all the children regained normal elbow function. There were no cases of avascular necrosis.

The CINCA syndrome: a rare cause of chronic arthritis and multisystem inflammatory disorders.

Chronic infantile neurological cutaneous articular (CINCA) syndrome is a rare disorder with neonatal onset characterised by a chronic progressive inflammatory process with skin rash, articular and central nervous system involvement. This primary systemic inflammatory disorder should be distinguished from juvenile rheumatoid arthritis (JRA). Although the articular findings are characteristic features of CINCA syndrome, there is a certain degree of variability in the articular involvements which are not always symmetrical nor is the degree of severity uniform. The etiology of CINCA syndrome remains unknown. No single treatment has been found to be effective. This syndrome is known in the American medical literature as infantile onset multisystem inflammatory disease (IOMID).

Bone scintigraphy in children with persistent pain in an extremity, suggesting algoneurodystrophy.

In this retrospective study, the data of bone scintigraphy performed in 21 children suspected of reflex sympathetic dystrophy (RSD) were analyzed. All of them had persistent pain in an extremity or a clinical suspicion of RSD. All children with strong suspicion of RSD showed diffuse hypoactivity at the level of the involved area on bone scintigraphy. This hypoactivity was clearly related to a decreased vascular supply. The specificity of this scintigraphic pattern is questionable, however, since two children without suggestive clinical signs for RSD had the same scintigraphic pattern.

Subperiosteal ganglion cyst of the tibia. A communication with the knee demonstrated by delayed arthrography.

We report a patient with a subperiosteal ganglion cyst of the tibia which was imaged by radiography, arthrography, CT and MRI. The images were correlated with the arthroscopic surgical and histological findings. Spiculated formation of periosteal new bone on plain radiographs led to the initial suspicion of a malignant tumour. Demonstration of the cystic nature of the tumour using cross-sectional imaging was important for the precise diagnosis. Communication between the ganglion cyst and the knee was shown by a delayed arthrographic technique, and the presence of this communication was confirmed at arthroscopy and surgically.

Split coronal fractures of the lumbar spine. Treatment by posterior internal fixation and transpedicular bone grafting.

The clinical and radiological results of 12 patients with a split coronal vertebral fracture were analysed with minimum follow-up of 24 months. All patients were treated operatively with an AO internal spinal fixator and transpedicular bone grafting. The operation was supplemented with posterior bone grafts in 4 patients. All fractures healed without marked deformity. There were no vertebral body pseudarthroses. There were no neurological or vascular injuries due to the placement of pedicle screws or to transpedicular bone grafting. 10 patients, had excellent or good results.

Bilateral stress fractures of the femoral neck complicated by unilateral displacement in a child.

Stress fractures of the femoral neck with an open capital femoral epiphysis in children are very rare. Up to the time of this writing, 12 cases have been described in children between the ages of 5 and 16 years (2, 4, 10-12, 14). The differential diagnosis from other hip diseases causing pain, a limp, and limited movement can be difficult when standard radiographs are normal. In this situation, tomography, isotope bone scanning, and magnetic resonance imaging (MRI) have proved to be very useful in both adults and children (2, 3, 5-8, 10-12). Complications such as nonunion or severe displacement are uncommon in children and have occurred only after they have resumed or continued the causal activity (12). As far as we are aware, bilateral development of a fatigue fracture of the femoral neck in a child has never been reported. We describe the case of an 8-year-old girl who sustained first a right then later a left femoral neck stress fracture. Displacement of the left fracture occurred after a minor but significant injury and required surgical treatment.

Unusual evolution of a benign-looking cortical defect of the proximal humerus. A case of intracortical osteosarcoma?

A case of an osteosarcoma following a pathological fracture through a small benign-looking cortical lesion of the proximal humerus is described. The unusual evolution from a small cortical lesion to a malignant lesion raises the question whether this is a case of an intracortical osteosarcoma that has some distinct features from those of previously reported cases.

Radial neck osteolysis after annular ligament reconstruction. A case report.

The treatment of the dislocated radial head in a late Monteggia lesion remains a matter of controversy. Annular ligament reconstruction using a strip of triceps tendon is a commonly used technique. Although most published series report good and excellent results, the overall complication rate of this procedure is not known. This study reports a 9-year-old boy who had avascular necrosis and bone resorption of the radial neck after a late annular ligament reconstruction using a sling of triceps tendon for a radial head dislocation that was not detected previously.

Atlantoaxial rotatory fixation. A case report and proposal of a new classification system.

Atlantoaxial rotatory fixation (AARF) remains a relatively rare finding. A case of AARF is reported and the existing Fielding and Hawkins classification is reviewed. Furthermore a new classification system is proposed.