High prevalence of Candida dubliniensis in lower respiratory tract secretions from cystic fibrosis patients may be related to increased adherence properties.

OBJECTIVES: We identified Candida spp isolated from lower respiratory tract secretions obtained from cystic fibrosis (CF) patients, by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), with the aim of determining the most prevalent causative agent. We also sought to determine their adhesive properties in order to understand their biology related to CF. METHODS: Twenty-five clinical samples were collected from a cohort of 20 CF patients. Twenty-six isolates of Candida spp were isolated and identified by MALDI-TOF MS method. Adherence assays were performed using the Fluxion BioFlux 200, a flow apparatus that allows for the visualization of adhering cells. RESULTS: MALDI-TOF MS analysis revealed C. dubliniensis to be the most prevalent species (n=18, 69%), followed by C. albicans (n=4), C. tropicalis (n=3), and C. glabrata (n=1). C. dubliniensis showed the strongest adherence under constant flow when compared to the other species of Candida. In the majority of cases, C. dubliniensis was isolated in combination with Pseudomonas aeruginosa and Staphylococcus aureus. C. dubliniensis appears to be able to survive in the CF lung and coexist with bacteria. CONCLUSIONS: The data presented here show that the presence of C. dubliniensis in the lower airways of CF patients may be related to increased adherence properties.

Molecular identification and susceptibility pattern of clinical Nocardia species: Emergence of Nocardia crassostreae as an agent of invasive nocardiosis.

BACKGROUND: Nocardia species are rare, opportunistic organisms that cause disease in both immunocompetent and immunocompromised individuals. OBJECTIVE: To investigate the clinical presentations of various Nocardia infections based on the 16S ribosomal RNA gene of the isolate, as well as related risk factors and susceptibility patterns to antimicrobial agents. METHODS: Thirteen patients with a diagnosis of nocardiosis were included in the present study. Seven Nocardia species were identified by 16S ribosomal RNA. Susceptibility testing was performed using six antimicrobial agents. RESULTS: Five patients were immunocompromised, and eight were immunocompetent with predisposing factors including cystic fibrosis, tuberculosis and ophthalmic infections. Nocardia caused pulmonary infections in eight patients (61.5%), invasive systemic infections in three patients (23%) and local (ophthalmic) infections in two patients (15.4%). In the patients with pulmonary disease, nocardiosis was caused by six species (Nocardia cyriacigeorgica, Nocardia otitidiscaviarum, Nocardia farcinica, Nocardia carnea, Nocardia testacea and Nocardia asiatica). The seventh species identified in the present study was Nocardia crassostreae. DISCUSSION: N crassostreae is a multidrug-resistant organism that was reported to be an emerging human pathogen causing invasive nocardiosis in a patient with non-Hodgkin's lymphoma. N farcinica was isolated from blood in a patient with breast cancer. None of the Nocardia isolates were resistant to linezolid. One N otitidiscaviarum isolate was a multidrug-resistant organism. All patients in the present study were treated with the appropriate antibiotics and their condition resolved without further sequelae. CONCLUSIONS: The present study is the first report on N crassostreae as a human pathogen. The detection of multidrug-resistant species necessitate molecular identification and susceptibility testing, and should be performed for all Nocardia infections. Nocardiosis manifests various clinical features depending on the Nocardia species and underlying conditions.

HISTORIQUE: Les espèces de Nocardia sont des organismes opportunistes rares qui sont pathogènes à la fois chez les personnes immunocompétentes et immunodéprimées. OBJECTIF: Explorer la présentation clinique de diverses infections à Nocardia d'après le gène d'ARN ribosomique 16S de l'isolat, ainsi que les facteurs de risque connexes et les profils de susceptibilité aux antimicrobiens. MÉTHODOLOGIE: Treize patients ayant un diagnostic de nocardiose ont participé à la présente étude. Les chercheurs ont repéré sept espèces de Nocardia au moyen de l'ARN ribosomique 16S. Ils ont effectué les tests de susceptibilité à six antimicrobiens. RÉSULTATS: Cinq patients étaient immunodéprimés et huit étaient immunocompétents, mais présentaient des facteurs de prédisposition, y compris la fibrose kystique, la tuberculose et des infections ophtalmiques. La Nocardia a provoqué des infections pulmonaires chez huit patients (61,5 %), des infections systémiques invasives chez trois patients (23 %) et des infections locales (ophtalmiques) chez deux patients (15,4 %). Chez les patients atteints d'une maladie pulmonaire, la nocardiose était attribuable à six espèces (Nocardia cyriacigeorgica, Nocardia otitidiscaviarum, Nocardia farcinica, Nocardia carnea, Nocardia testacea et Nocardia asiatica). La septième espèce observée dans la présente étude était la Nocardia crassostreae. EXPOSÉ: La N crassostreae, un organisme multirésistant considéré comme un agent anthropopathogène émergent, était responsable d'une nocardiose invasive chez un patient atteint d'un lymphome non hodgkinien. Les chercheurs ont isolé le N farcinica dans le sang d'un patient atteint d'un cancer du sein. Aucun des isolats de Nocardia n'était résistant à la linézolide. Un isolat de N otitidiscaviarum était multirésistant. Tous les patients participant à la présente étude ont reçu un traitement aux antibiotiques pertinent et se sont rétablis sans autres séquelles. CONCLUSION: La première étude est la première à faire état de la N crassostreae comme agent anthropopathogène. Pour déceler les espèces multirésistantes, il faut procéder à une identification moléculaire et à un test de susceptibilité, des mesures qu'il faudrait prendre à l'égard de toutes les infections à Nocardia. La nocardiose s'associe à diverses caractéristiques cliniques, selon l'espèce de Nocardia et les maladies sousjacentes.

The pattern of Down syndrome among children in Qatar: a population-based study.

BACKGROUND: The objective of the present study was to determine the prevalence pattern of Down Syndrome (DS) in children <5 years of age in the State of Qatar. This is a retrospective descriptive study. The study was conducted in the Hamad General Hospital, Women's Hospital, and Rumailah Hospital (Hamad Medical Corporation). A total of 146 children were reported as having DS during the 6-year period from 1 January 2000 to December 31, 2005. METHODS: The diagnostic classification of definitive DS was made in accordance with criteria based on the International Classification of Disease 10th Revision (ICD-10). The data collected from the medical records included sociodemographic characteristics of the children, genetic and family history, pedigree analysis, and clinical genetic examination. RESULTS: A total of 146 children were diagnosed with DS during the last 6-year period and the prevalence rate is 19.5 per 10,000 live births. Of these, 40.4% were Qataris and 59.6% were non-Qataris. DS was slightly more common in boys (52.7%) than girls (47.3%). Infants <1 year old had the highest frequency of DS (40.4%), followed by children (1-2) years (26%). The most common abnormality was regular trisomy (98%). Also, one-half of the studied children had congenital heart problems (51.7%). There is a significant relationship between DS and maternal age as reported by other studies in other countries. CONCLUSION: The identification of specific types of chromosomal abnormalities in DS children is important as it enables clinicians to accurately counsel the parent regarding the recurrence risk and available options.