U. Ozcelik

Mycobacterial disease and impaired IFN-γ immunity in humans with inherited ISG15 deficiency.

Tuberculosis Vaccine Conundrum Some children experience severe clinical disease when they are vaccinated against tuberculosis, an attenuated live vaccine that is normally innocuous in humans. Several germline mutations have been identified that account for this susceptibility, and now Bogunovic et al. (p. 1684, published online 2 August) add another to the list—ISG15. Uncovering this mutation, which is inherited in an autosomal recessive manner, was a surprise because studies with mice deficient in ISG15 showed enhanced susceptibility to some viral, but not bacterial, infections. Nevertheless, patients lacking ISG15 were not able to produce adequate amounts of interferon-γ, a cytokine critical for clearance of the bacteria. A mutation that accounts for adverse reactions to the Bacille Calmette-Guérin vaccine against tuberculosis is identified. ISG15 is an interferon (IFN)-α/β–inducible, ubiquitin-like intracellular protein. Its conjugation to various proteins (ISGylation) contributes to antiviral immunity in mice. Here, we describe human patients with inherited ISG15 deficiency and mycobacterial, but not viral, diseases. The lack of intracellular ISG15 production and protein ISGylation was not associated with cellular susceptibility to any viruses that we tested, consistent with the lack of viral diseases in these patients. By contrast, the lack of mycobacterium-induced ISG15 secretion by leukocytes—granulocyte, in particular—reduced the production of IFN-γ by lymphocytes, including natural killer cells, probably accounting for the enhanced susceptibility to mycobacterial disease. This experiment of nature shows that human ISGylation is largely redundant for antiviral immunity, but that ISG15 plays an essential role as an IFN-γ–inducing secreted molecule for optimal antimycobacterial immunity.

Long-term results of disodium etidronate treatment in pulmonary alveolar microlithiasis.

Pulmonary alveolar microlithiasis (PAM) is a rare disease with alveolar microliths mainly composed of calcium phosphate. The gene responsible for the disease is SLC34A2, which encodes a type‐IIb sodium phosphate cotransporter, has been described recently. Treatment of this disease is not clearly defined. Disodium etidronate is a member of bisphonates and it has been administered in these patients due to its inhibitory effect on the precipitation of hydroxyapatite microcrystals. Here, clinical and radiological improvement of two patients with PAM who were treated with disodium etidronate for 9 and 11 years, respectively, are presented. The pathogenetic mechanism of this treatment on the genetic basis of disease is discussed. Pediatr Pulmonol. 2010; 45:514–517.

Prevalence and genetic diversity of Staphylococcus aureus small-colony variants in cystic fibrosis patients

Staphylococcus aureus small-colony variants (SCVs) are being isolated more frequently in cystic fibrosis (CF) patients. We aimed to determine the prevalence of S. aureus SCVs and their phenotypic and genotypic properties in CF patients admitted to a university hospital. Specimens of 248 patients were examined during a period of 11 months. Colonies supposed to be SCVs were evaluated on Columbia blood agar, mannitol salt agar, and brain-heart infusion agar with 5% NaCl (BHIA 5% NaCl). Strains were confirmed by S. aureus nucA PCR. Antibiotic susceptibilities of SCVs and simultaneously isolated S. aureus strains were determined for oxacillin, gentamicin, trimethoprim-sulphamethoxazole, vancomycin, ciprofloxacin, linezolid, and tigecycline. Genetic relatedness between SCVs and normal S. aureus strains was determined with a pulsed-field gel electrophoresis (PFGE) method. S. aureus SCVs were detected in 20 of 248 patients (8.1%). The highest SCV isolation rate was obtained with MSA, followed by BHIA 5% NaCl. Auxotrophism for thymidine was demonstrated in six SCVs. The tigecycline susceptibilities of 48 SCV strains isolated in this study showed higher MIC values than those of 33 simultaneously isolated normal S. aureus strains. Whereas SCVs and normal S. aureus strains showed identical genotypes in 14 of the patients, five patients showed different genotypes. This first study from Turkey evaluating S. aureus SCVs in CF patients has indicated the importance of considering and reporting SCVs in chronic infections such as CF. The presence of SCVs will probably indicate persistent infection, and this might impact on antibiotic treatment decisions, as they are more resistant to antibiotics.

Antioxidant effect of β-carotene in cystic fibrosis and bronchiectasis: clinical and laboratory parameters of a pilot study

The carotenoids are potent antioxidants with the ability to quench singlet oxygen and other toxic oxygen species. The aim of this pilot study was to investigate the protective effect of β‐carotene on oxidant system in patients with cystic fibrosis (CF) and in patients with bronchiectasis (BE) caused by a reason other than CF. Eighteen children with CF and 15 children with BE followed in the Pediatric Chest Disease Unit of Hacettepe University, and 15 healthy children participated in the study. Compared with the controls, significantly lower plasma levels of β‐carotene were found in the CF group and significantly lower plasma levels of vitamin E in the CF and BE groups. The standardization of carotenoid levels for total cholesterol did not significantly attenuate these differences. In addition, there were significantly higher levels of malondialdehyde (a marker of lipid peroxidation) and tumour necrosis factor‐α (TNF‐α) in children with CF and in children with BE than in normal subjects. After 6 mo of β‐carotene supplementation, the plasma levels of β‐carotene and vitamin E increased and the plasma levels of TNF‐α and malondialdehyde decreased in both groups.

Epidemiology of chronic Pseudomonas aeruginosa infections in cystic fibrosis

Chronic lung infection with Pseudomonas aeruginosa is primarily responsible for pulmonary deterioration of cystic fibrosis patients. The purpose of this study was to type the P. aeruginosa isolates collected sequentially from cystic fibrosis patients, chronically colonized with P. aeruginosa, by random amplified polymorphic DNA fingerprinting-PCR (RAPD-PCR). Sequential P. aeruginosa isolates (n: 130) that had been collected from 20 CF patients over at least 9 years were investigated. The isolates were analyzed by RAPD-PCR using two arbitrary primers. Antimicrobial susceptibility testing of all isolates was performed by the disc diffusion method. RAPD-PCR typing demonstrated that strains dissimilar in colony morphotype and of different antibiotic susceptibility patterns could be of the same genotype. Some CF patients were colonized with a rather constant P. aeruginosa flora, with strains of different phenotypes but of one genotype. However, some patients may be colonized with more than one genotype. The results also demonstrated that there might be a risk of cross-colonization between CF patients followed-up at the same center.

Neutrophil chemotaxis in acutely infected and clinically stable cystic fibrosis patients

Abstract Purpose: The aim of the present study was to evaluate the role of neutrophil chemotaxis in cystic fibrosis (CF) and to also determine whether an acute bacterial infection and the nutritional status of a child can affect neutrophil chemotaxis.

Cytomegalovirus infection in immunocompetent wheezy infants: the diagnostic value of CMV PCR in bronchoalveolar lavage fluid

Cytomegalovirus (CMV) pneumonitis in immunocompetent hosts is uncommon but is being recognized more frequently, particularly when presenting as severe viral pneumonia.

Predominance of hospital-associated MRSA among cystic fibrosis patients in a Turkish reference cystic fibrosis centre

Abstract Methicillin-resistant Staphylococcus aureus (MRSA) strains are the major causative agents of numerous hospital- and community-acquired infections. Increasing prevalence of MRSA in cystic fibrosis (CF) populations is reported all over the world. Although there are papers reporting the prevalence and genetic backgrounds of MRSA isolates from different settings in Turkey, there is no information regarding the situation in the CF community. This study was conducted to characterize the MRSA strains recovered from CF patients followed-up at a Turkish reference CF centre. Microbiological testing of isolates was performed via conventional microbiological techniques. Molecular characterization of MRSA isolates was carried out by SCCmec typing by multiplex PCR and PVL gene determination. Among a total of 604 CF patients included in the study, 325 patients were found to harbour S. aureus (53·8%). Of those 325 patients, 24 were positive for MRSA during their follow-up (7·4%). Thirty-two MRSA isolates from these patients were chosen for further assessment of molecular characteristics. Twenty-six MRSA isolates exhibited a pattern like SCCmec type III (81·2%) and six consecutive MRSA isolates of a single patient revealed SCCmec type IV (18·7%). Our findings definitely support the need for further surveillance studies for CF-MRSA strains and highlight the need for infection control measures in the setting of CF centres.

Idiopathic interstitial pneumonias: Diagnosis, treatment and follow-up

tissue in the neighborhood of esophagus was detected. It was seen that the bottom of the cyst has extended to on the arch aortic and the cyst was connected to the esophagus muscular layer with the tight connective tissue. Microscopic appearance of lesion, smooth muscle tissue with double row in the wall of cystic tissue whose inner surface is paved with silial cylindrical epithelium, mononuclear inflammatory cells in these regions, congested vasculars are seen and these are found compatible with the esophageal cyst. The patient’s breathing and wheeze do not occur again after the operation. Although the diagnosises of asthma which do not heal and not respond the bronchodilator treatment in infant do not occur frequently, mediastinal masses should be kept in mind.

148 Burkholderia cepacia complex isolation and identification in a Turkish CF Unit

Introduction: Isolation of B. cepacia complex (Bcc) in sputum from CF patients carries a significant medical importance. Rapid and precise identification is essential to evaluate risks in terms of prognosis and epidemicity. This study was performed to evaluate the prevalence and genomovar status of Bcc in our CF population. Methods: Sputum samples colllected from 92 CF patients were inoculated onto OFBL agar for the isolation of Bcc. Phoenix@ Identification System was used for phenotypic analysis. Nucleic acid purification from sputum was performed using High Pure PCR Template Kit©. Bcc rec A gene was amplified utilizing BCR-1 and BCR-2 primers. Bcc strain KK 7394 (Neqas, UK) was used as reference strain and P putida as negative control. For the validation of PCR, another CF sputum with no pathogenic bacterial growth was spiked with 107 cfu/ml reference strain. Restriction fragment length polymorphism (RFLP) was done for the molecular identification of Bcc isolate. Results: Bcc was isolated from 2 out of 92 samples (2.2%) and phenotypically verified using the automatized system. PCR was shown to detect DNAs from reference strain, spiked sample and one of the sputum samples from which Bcc was isolated (1.1%). RecA PCR (+) strain was identified as B. multivorans by RFLR Conclusion: Although Bcc is an infrequent pathogen in our CF population, special care should be given for its isolation and identification since it has considerable impact on morbidity and mortality in CE Identification of putative Bcc isolates should be confirmed by molecular methods as misidentification may occur when only phenotypic analysis is considered. 4. Microbiology