Respiratory carriage of the novel Kingella negevensis species by young children.

Kingella negevensis, a novel Kingella species implicated in a pediatric joint infection, has been recently characterized but its epidemiology remains largely unknown. The pharyngeal carriage of K. negevensis was studied by re-examining the results of a previous longitudinal study conducted in a cohort of healthy Israeli children from whom upper respiratory tract specimens were sequentially cultured between the ages of 2 and 36 months. Isolates were identified as K. negevensis by a species-specific nucleic amplification assay and genotyped by pulsed-field gel electrophoresis. ß-lactamase production was determined by the nitrocephin test. Kingella negevensis was detected in 26 of 4,472 (0.58%) oropharyngeal cultures obtained from 24 of 716 children (3.35%) and was not isolated from any of 4,472 nasopharyngeal specimens. Following the first 6 months of life during which none of the children was colonized, the prevalence of carriage gradually increased reaching a peak of 1.09% at 24 months of age and decreased thereafter. Kingella negevensis strains showed genomic heterogeneity, and two clones represented 22 of 26 (84.62%) isolates. Twelve of the 26 (46.15%) isolates, belonging to two distinct clones, produced ß-lactamase. Kingella negevensis shows remarkable similarities with K. kingae in terms of colonization site, age-related patterns of acquisition and carriage, and clonal distribution of ß-lactamase production. Additional research is needed to investigate potential colonization sites of K. negevensis outside the respiratory tract, explore the mechanisms of pharyngeal colonization by the organism, and determine its role as an invasive human pathogen.

Primary subacute epiphyseal osteomyelitis caused by Mycobacterium species in young children: a modern diagnostic approach.

Primary epiphyseal subacute osteomyelitis (PESAO) caused by Mycobacterium species in young children is poorly recognized. We aimed to define the spectrum of this uncommon condition and to propose a novel diagnostic approach. We performed a systematic review of the literature on the PubMed website by selecting all reports of isolated infantile PESAO caused by Mycobacterium species since 1975. We identified 350 citations, of which 174 were assessed for eligibility based on title and abstract. The full text of 81 eligible citations was screened, and relevant data of 15 children under 4 years of age with mycobacterial PESAO were extracted. These data were pooled with those from our Institution. Data from 16 children were reviewed. The median age was 16 ± 7 months and the male:female ratio 1.7. The knee was the most common infection site (94%). The diagnosis of mycobacterial disease was delayed in all cases (range, 2 weeks to 6 months), and initially presumed by histology in 15 children (94%). Microbiologically proven diagnosis was confirmed by bone cultures in 8 of the 15 children (53%), and by specific PCR in 2 of the 3 culture-negative bone specimens (67%). Three children experienced long-term orthopedic complications despite surgical drainage and prolonged antimycobacterial regimens. All recently reported cases came from high-burden tuberculosis areas. Mycobacterium species contribute to the burden of infantile PESAO in endemic tuberculosis areas and may cause growth disturbances. We argue in favor of the early recognition of mycobacterial disease by specific molecular assays in children with infantile PESAO living in high-burden areas.

[Pediatric keratocystic odontogenic tumor and nevoid basal cell carcinoma syndrome. Predictive factors for recurrence and aggressiveness]. / Tumeurs kératokystiques odontogènes de l'enfant et syndrome de Gorlin. Comment expliquer les récidives et l'agressivité des lésions ?

INTRODUCTION: Keratocystic odontogenic tumors (KOT), as complications in Nevoid Basal Cell Carcinoma Syndrome (NBCCS), occur early (before 20 years of age) and are usually more aggressive. The aim of this retrospective study was to determine the clinical, histological, and genetic phenotype, of these lesions and to define predictive features of aggressiveness. PATIENTS AND METHODS: We retrospectively studied five patients presenting with one or several KOT with NBCCS. We collected their clinical, radiological, and therapeutic data, rate of recurrence or new localization. Anatomopathological examinations were reviewed systematically. Somatic PTCH, SMO and SMAD 4 sequencing were completed. RESULTS: The average age at diagnosis was 11.2 years. The average number of KOT was 3.2 most often located in the molar region. All the cysts were enucleated. Anatomopathological examination revealed the presence of satellite cysts and daughter cysts and epithelial expansion in more than 80% of cases. No somatic mutation was observed among KOT. DISCUSSION: KOT develop in the first 10 years, in patients presenting with NBCCS, and recurrence is observed in the second and third decade. KOT are typically aggressive and have a tendency to recur, especially in patients with NBCCS. Anatomopathological examination may be predictive of the lesion's aggressiveness. Understanding the genetic and immunological mechanisms should open the way for new medical treatment.