Discrepancy in MALDI-TOF MS identification of uncommon Gram-negative bacteria from lower respiratory secretions in patients with cystic fibrosis.

Early identification of microbial organisms from respiratory secretions of patients with cystic fibrosis (CF) is important to guide therapeutic decisions. The objective was to compare the accuracy of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) relative to the conventional phenotypic method in identifying common bacterial isolates, including nonfermenting Gram-negative bacteria, in a cohort of patients with CF. A total of 123 isolates from 50 patients with CF representing 14 bacterial species from respiratory specimens were identified using MALDI-TOF MS in parallel with conventional phenotypic methods. Discrepancies were confirmed by 16S ribosomal RNA (rRNA) gene sequencing in five Gram-negative isolates. The MALDI-TOF MS managed to identify 122/123 (99.2%) bacterial isolates to the genus level and 118/123 (95.9%) were identified to the species level. The MALDI-TOF MS results were 100% consistent to the species level with conventional phenotypic identification for isolates of Staphylococcus aureus, Pseudomonas aeruginosa, Haemophilus influenzae, Streptococcus pyogenes, Achromobacter xylosoxidans, Stenotrophomonas maltophilia, and other uncommon organisms such as Chryseobacterium gleum and Enterobacter cloacae. The 5/123 (4.6%) isolates misidentified were all Gram-negative bacteria. The isolation of E. cloacae and Haemophilus paraphrohaemolyticus may extend the potentially pathogenic list of organisms isolated from patients with CF. Although the technique provides an early identification and antimicrobial therapy approach in patients with CF, limitation in the diagnosis of uncommon Gram-negative bacteria may exist

Genetic relatedness and host specificity of Pseudomonas aeruginosa isolates from cystic fibrosis and non-cystic fibrosis patients

Background: Pseudomonas aeruginosa is one of the primary pathogens isolated more frequently in cystic fibrosis (CF) and it exhibits innate resistance to a wide range of antibiotics. Purpose: We sought to determine whether the highly prevalent genotypes of P. aeruginosa are specifically linked to CF patients and have any related multidrug antibiotic resistance. Isolates from hospitalized non-CF patients and from environmental sources were also genotypically analyzed. Methods: Collections of P. aeruginosa from lower respiratory secretions (n=45) were genotyped using pulsed-field gel electrophoresis (PFGE). Phenotypic screening for antibiotic susceptibility was performed for the common antimicrobial agents by E-test and automated Phoenix method. Results: P. aeruginosa isolates from CF (n=32), hospitalized non-CF patients (n=13), and environment sources (n=5) were analyzed. The population structure of P. aeruginosa is highly diverse and population-specific. All PFGE results of P. aeruginosa isolates fall among four major clusters. Cluster 1 contained 16 P. aeruginosa isolates from CF patients and two from environmental sources; cluster 2 contained 11 P. aeruginosa isolates from CF and one each from non-CF and environmental sources; cluster 3 contained 12 P. aeruginosa isolates from hospitalized non-CF patients and two P. aeruginosa isolates from one CF patient and one environmental source; and cluster 4 consisted of three isolates from CF patients and one from the environment. The majority of multidrug-resistant P. aeruginosa isolates were in clusters 3 and 4. P. aeruginosa isolates from CF patients were resistant to ciprofloxacin (34.4%) followed by resistance to amikacin and gentamicin (each 28%), whereas the majority of isolates from non-CF patients were resistant to meropenem (69%) and were grouped in cluster 3. Conclusion: PFGE of P. aeruginosa isolates from CF patients shows a high degree of similarity, suggesting specific adaptation of these clones to CF-affected lungs. The hospitalized non-CF cluster has a different clonal origin, indicating specific clustering in a specific location, suggesting hospital-acquired P. aeruginosa infections.The Qatar National Research Fund (UREP 14-026-3-010)

A Rare Pediatric Case of Severe Bird Fancier’s Lung Presented with Viral Pneumonitis-Like Picture

Bird Fancier’s Lung (BFL) is a rare, nonatopic immunologic response to repeated or intense inhalation of avian (bird) proteins/antigens found in the feathers or droppings of many species of birds, which leads to an immune-mediated inflammatory reaction in the respiratory system. Although this is the most common type of hypersensitivity pneumonitis (HP) reported in adults, it is one of the classifications of a rare subtype of interstitial lung disease that occurs in the pediatric age group of which few case reports are available in the literature. The pathophysiology of HP is complex; numerous organic and inorganic antigens can cause immune dysregulation, leading to an immune-related antigen⁻antibody response (immunoglobulin G—IgG- against the offending antigen). Diagnosing BFL in the pediatric age group is challenging due to the history of exposure usually being missed by health care providers, symptoms and clinical findings in such cases being nonspecific and often misdiagnosed during the acute illness with other common diseases such asthma or acute viral lower respiratory tract infection, and the lack of standardization of criteria for diagnosing such a condition or sensitive radiological or laboratory tests. Treatment, on the other hand, is also controversial. Avoidance of the offending antigen could be the sole or most important part of treatment, particularly in acute mild and moderate cases. Untreated cases can result in irreversible lung fibrosis. In this case report, we highlight how children presenting with an acute viral lower respiratory tract infection can overlap with the acute/subacute phase of HP. Early intervention with pulse steroids markedly improves the patient’s clinical course

Use of Intravenous Pulse Steroids to Treat Allergic Bronchopulmonary Aspergillosis in a Non-Compliant Asthmatic Adolescent

Allergic bronchopulmonary aspergillosis (ABPA) is an immune-mediated inflammatory airway disease that predominantly affects patients with cystic fibrosis (CF) and, less commonly, patients with asthma. ABPA can lead to irreversible lung injury and bronchiectasis if not treated early and aggressively. Long-term oral steroids are the standard therapy of ABPA. However, it is associated with an increased risk of steroids side effects and possible medication noncompliance. Monthly intravenous pulse methylprednisolone (IV-PS) has been used as an alternative to oral steroids to treat CF-related ABPA with a reportedly similar clinical response and less steroid-related side effects. To our knowledge, the use of IV-PS in asthma-related ABPA has not been previously reported. We report the successful management of asthma-related ABPA in an adolescent using intravenous pulse methylprednisolone in addition to oral itraconazole with no significant steroid-related side effects

Persistence of Candida dubliniensis and lung function in patients with cystic fibrosis

Abstract Objectives Candida dubliniensis is an emerging yeast and demonstrated a high adherence property to cystic fibrosis respiratory tract. Therefore, it is important to determine the persistence of C. dubliniensis and to assess the possible relationship to the body mass index (BMI) and forced expiratory volume in 1st second (FEV1). Results Candida isolates were identified by MALDI-TOF MS to species level from 40/52 (76.9%) cystic fibrosis patients. C. dubliniensis was the most common organism isolated from 50/77 (65%) lower respiratory specimens of 29 patients. Patients with persistent C. dubliniensis isolates have higher mean BMI in comparison to intermittent C. dubliniensis group. However, this difference did not reach statistical significance (P = 0.539). In contrast, patients with persistent C. dubliniensis isolates have significantly lower FEV1% mean in comparison to intermittent C. dubliniensis group particularly at initial two visits (P < 0.05); however, at subsequent visit the difference observed was not statistically significant (P = 0.456). The persistence of C. dubliniensis is more frequent in adults having more advanced disease, co-infections with chronic P. aeruginosa, cystic fibrosis related diabetes, long-term nebulized tobramycin and oral Zithromax therapy than patients with intermittent C. dubliniensis. Patients with persistent C. dubliniensis have lower FEV1 percentage and higher BMI than the intermittent C. dubliniensis

Serum Zinc Level in Asthmatic and Non-Asthmatic School Children

Asthma is one of the most common chronic disorders among children. Zinc (Zn) is an essential dietary antioxidant and may have a special role in assisting the airways of asthmatic subjects. The primary objective of this study was to measure serum Zn levels among asthmatic school children and to compare this to the serum Zn level in non-asthmatic children. The secondary objective was to investigate the relationship between Zn levels and the degree of asthma control. A cross-sectional study following forty asthmatic children and forty matched non-asthmatic children of both genders was conducted. Weight, height, body mass index (BMI), BMI Z-scores, serum Zn, hemoglobin, total protein, and albumin concentrations were measured in both groups. Serum immunoglobulin E (IgE) levels, the forced expiratory volume in 1 second (FEV1), and dosage of inhaled steroids were measured in asthmatic school children. The results show the mean Zn level among asthmatic children was 12.78 ± 1.8 μmol/L. Hypozincemia was detected in four asthmatic children. Asthma and control groups were matched in age, gender, and BMI Z score (p &gt; 0.05). No significant difference was observed in Zn levels, hemoglobin, albumin, and total protein between both groups (p &gt; 0.05). Among asthmatics, Zn levels were not significantly associated with the degree of asthma control (well controlled, mean Zn = 12.9 ± 1.5, partially controlled, mean Zn = 11.9 ± 1.6, and uncontrolled, mean Zn = 3.62 ± 2.2) (p = 0.053). The Zn level was not correlated with the FEV1 Z score. There was no significant association between Zn level and the dosage of inhaled steroids or IgE concentrations (p &gt; 0.05). The findings show that Zn may not play a major role in the degree of asthma control. Larger studies are needed to confirm these results

Host specificity of pseudomonas aeruginosa isolates from patients with cystic fibrosis and patients from different clinical backgrounds.

Background: Pseudomonas aeruginosa is one of the primary pathogens being isolated more frequently in cystic fibrosis (CF) and exhibits innate resistant to a wide range of antibiotics. Purpose: To determine whether the highly prevalent genotypes of P. aeruginosa are specifically linked to CF patients, isolates from non-CF patients and environment sources were genotypically analyzed. Methods: Collections of P. aeruginosa from lower respiratory secretions (n= 57) were genotyped using pulse-field gel electrophoresis (PFGE). Phenotypic screening for antibiotic susceptibility was performed for the common antimicrobial agents by Etest and automated Phoenix. Results: P. aeruginosa isolates from CF (n=39), non-CF patients (n=13), and environment sources (n=5) were analyzed. The population structure of P. aeruginosa is highly diverse and population specific. All the strains fall among 3 major clusters. Cluster A contained 16 isolates from CF patients and 2 environmental; cluster B contained 12 isolates from CF and one environmental while cluster C contained all the isolates from non CF patients and one environmental. The majority of P. aeruginosa strains in CF were resistant to ciprofloxacin (25.7%) followed by amikacin and gentamicin (each 23.6%). Whereas, the majority of isolates from non-CF were resistant to meropenem (69%), which grouped in cluster C. Conclusion: The fingerprints obtained with P. aeruginosa isolates from CF patients have a high degree of similarity, suggesting specific adaptation of these two clones to CF lung. The third non-CF cluster has different clonal origin, indicating specific clustering in both location and patient group

An Overview of the Homozygous Cystic Fibrosis Transmembrane Conductance Regulator Mutation c.3700 A>G (p.Ile1234Val) in Qatar

Purpose of Review Cystic fibrosis (CF) is a monogenic recessive disease with multisystem involvement. The cause is a mutation in the gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The aim is to review the literature involving the CFTR I1234V mutation and to provide recommendations for future research activities. Recent Findings The prevalence rates of CFTR mutations vary across the globe. The CFTR I1234V mutation is the most common mutation in Qatar, and one of the most common in the Arabian Gulf region. Summary Areas for future research include testing of the CFTR transcript and activity levels in different samples including nasal cells and organoids. Another area is applying Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technology as a tool for gene editing.Other Information Published in: Current Genetic Medicine Reports License: https://creativecommons.org/licenses/by/4.0See article on publisher's website: http://dx.doi.org/10.1007/s40142-019-00174-7</p

The emergence of multidrug-resistant Pseudomonas aeruginosa in cystic fibrosis patients on inhaled antibiotics

Introduction: Multidrug-resistant Pseudomonas aeruginosa (MDR-PA) is an important and growing issue in the care of patients with cystic fibrosis (CF), and a major cause of morbidity and mortality. Objective: The objective of the study was to describe the frequency of MDR-PA recovered from the lower respiratory samples of pediatric and adult CF patients, and its antibiotic resistance pattern to commonly used antimicrobial agents including β-lactams, aminoglycosides, and fluoroquinolones. Materials and Methods: The lower respiratory isolates of P. aeruginosa were obtained from inpatients and outpatients CF clinics from a tertiary care teaching hospital for the period from October 2014 to September 2015. The identification and antimicrobial susceptibility for all the isolates were performed by using the BD Phoenix™ and E-test in compliance with Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: A total of 61 P. aeruginosa samples were isolated from thirty CF patients from twenty families. Twelve sputum samples were positive for MDR-PA (seven nonmucoid and five mucoid isolates) from five CF patients (five families) with moderate-to-very severe lung disease given MDR-PA frequency of 19.7%. The median age of the study group was 20 (range 10–30) years. Three CF patients were on chronic inhaled tobramycin and two on nebulized colistin. The antimicrobial patterns of isolates MDR-PA showed the highest rate of resistance toward each gentamycin, amikacin, and cefepime (100%), followed by 91.7% to ciprofloxacin, 75% to tobramycin, 58.3% to meropenem, and 50% to piperacillin-tazobactam. None of the isolates were resistant to colistin during the study period. Conclusion: The study results emphasize that the emergence of a significant problem in the clinical isolates of P. aeruginosa in CF patients that dictate appropriate attention to the antibiotic management after proper surveillance