Bacteria In Cystic Fibrosis Patients Research Articles

First report on the prevalence of bacteria in cystic fibrosis patients (CF) in a tertiary care center in Saudi Arabia.

IntroductionBacterial infections in CF patients are common and start early in life. The prognosis of the disease is substantially dependent on chronic respiratory infection and inflammation. Pseudomonas aeruginosa (PA) infection or chronic colonization have been established to cause a chronic decline in pulmonary function (PFT), and/or increase CF mortality.ObjectivesTo obtain the prevalence of all bacterial pathogens in our CF patients and assess their evolution over time.MethodA retrospective review of 327 patients with confirmed CF of all age groups, who had respiratory culture samples at the first visit and on a regular follow-up between January 1, 1990 and December 2018, was conducted.ResultsA total of 327 patients had a respiratory culture obtained at presentation. Two hundred and sixteen (66%) of 327 patients are alive, while 111 (34%) have died. Respiratory cultures were taken from nasopharyngeal aspiration (NPA) in 199 patients (61%), tracheal aspirate in 9 (3%), bronchoalveolar lavage (BAL)in one (0.29%), and in 124 patients (38%), sputum was induced. The eastern province contributed to the highest number of patients (122, 37.7%). There is a persistent increase in the prevalence of the common bacteria over the follow-up period of 7 years, namely Hemophilus influenzae (H. influenzae), Staphylococcus aureus (S. aureus), and all Pseudomonas (P. aeruginosa) culture types.Comparing cultures from the first and last follow-up visits, there was an increase in the prevalence of all (P. aeruginosa) cultures from 120 (34%) to 137 (53%), and a decrease in the prevalence of (S. aureus) and (H. influenzae) during the same follow-up period.ConclusionThere is a progressive increase in the number of patients with the most pathogenic types of bacteria because of the advanced age at presentation. As more adult patients are enrolled, there is a need for improved awareness regarding the early eradication of pathogenic bacteria to prevent progressive pulmonary damage.

Investigation of role of anaerobic bacteria in cystic fibrosis patients

Repetitive pulmonary infections are the main cause of morbidity and mortality in cystic fibrosis (CF) patients. In recent years, non-culture dependent metagenomic studies showed complex dynamics of the pulmonary environment of CF patients and pointed out the importance of anaerobic bacteria. Molecular-based studies indicate that anaerobic bacteria can be found more than aerobic or facultative anaerobic bacteria in CF lung environment. However, limited number of studies are far away to clarify the importance of anaerobic bacteria in CF pulmonary disease. The aim of this study was to evaluate the role of anaerobic bacteria in CF patients admitted to Hacettepe University, Pediatric Respiratory Diseases Department, by using quantitative culture method for both aerobic and anaerobic bacteria. Anaerobic bacteria were identified by conventional and semi-automated methods. Antibiotic susceptibilities were performed by agar dilution method. Seventy-seven anaerobic bacteria were isolated from 35 (81.4%) of 43 patients. The total count of anaerobes and facultative bacteria (mean 16 x 106), was higher than aerobes and facultative bacteria (mean 14.1 x 106). If anaerobe culture were not performed merely 63.65% of all species could be obtained. In patients whose samples yielded intermediate or high numbers of PMNLs, significantly more obligate anaerobic bacteria were isolated (p= 0.046). Patients older than 18 years were colonized with higher number of anaerobic bacteria. Susceptibilities of 72 isolates out of 77, against ampicillin, sulbactam-ampicillin, piperacillin, piperacillin-tazobactam, moxifloxacin, metronidazole, imipenem, and clindamycin were also evaluated. Clindamycin was found to be the least effective antibiotic among all. None of the isolates was resistant to imipenem. This is the first study to show the role and importance of anaerobic bacteria in CF patients in our country. The resistance rates in anaerobic bacteria isolated from CF patients is concerning. Therefore, intermittent anaerobic culture and follow-up of resistance rates will be helpful in the follow-up of these patients.

Bacterial colonization status of cystic fibrosis children's toothbrushes: A pilot study

Pseudomonas aeruginosa and Staphylococcus aureus toothbrush contamination in cystic fibrosis (CF) is unknown. This pilot study aimed to determine their prevalence and the potential involvement of toothbrushes in pulmonary infection. Toothbrush bacteriological analysis for children aged 8-18 years was conducted on 27 CF patients, 15 healthy siblings, and 15 healthy children from the general population. S. aureus was detected on 22% of the patients' toothbrushes, and 13% of healthy children's toothbrushes and P. aeruginosa on 15% of patients' toothbrushes and 0-13% of healthy children's toothbrushes. There was no statistical correlation between pulmonary colonization and toothbrush contamination. P. aeruginosa genotyping showed two identical clones on the patients' toothbrushes and in their sputum, and between one patient's sputum and his sibling's toothbrush. S. aureus and P. aeruginosa can colonize CF patients' toothbrushes. The impact on pulmonary colonization remains unknown. Toothbrush decontamination methods need to consider these bacteria in CF patients.

Antibody response to Pseudomonas aeruginosa in children with cystic fibrosis

Cystic fibrosis (CF) is the most frequent life threatening autosomal recessive disease in white subjects. The primary cause of morbidity and mortality in children with CF is chronic pulmonary infection, mainly caused by Pseudomonas aeruginosa. The purpose of this study was to assess the value of the measurement of antibodies to P. aeruginosa in diagnosing lung infection by the bacteria in CF patients. We assessed P. aeruginosa antibody titers in CF patients from Rio de Janeiro, Brazil, using cell lysate antigens as well as recombinant PcrV, a Type III Secretion System protein. Sputum (more than 70% of the specimens) or oropharyngeal swabs were obtained whenever patients were regularly followed for their pulmonary disease. Blood samples were obtained with an average interval of 6 months for a period of 2 years. The ELISA cut-offs were assigned as the positive 95% confidence interval of the mean antibody levels from non-fibrocystic controls. Our data showed that most CF patients (81%) of whom were not chronically infected by P. aeruginosa (Groups I and II), had their first serology positive for rPcrV. Cell-lysate ELISA was able to detect P. aeruginosa antibodies before positive culture in the first serum sample of 44% of the patients from Groups I and II. When serum reactivity to rPcrV and cell lysate were combined, 94% of CF patients from Groups I and II (n = 16) had the first serology positive for P. aeruginosa over a mean time of 20 months before the first isolation of P. aeruginosa. In conclusion, longitudinal P. aeruginosa serology should become part of respiratory care follow-up, in conjunction with other lung parameter functions.

Survival of Lung Transplant Patients With Cystic Fibrosis Harboring Panresistant Bacteria Other Than Burkholderia cepacia, Compared With Patients Harboring Sensitive Bacteria

The impact of panresistant bacteria, other than Burkholderia cepacia, on the survival after lung transplantation in patients with cystic fibrosis (CF) remains controversial. To determine the impact of panresistant bacteria in CF patients on survival after lung transplantation a retrospective multicenter study was performed. All lung transplant recipients with a pre-transplant diagnosis of CF, at the University of Toronto (n = 53) and Duke University (n = 50), were included. Patients were included in the panresistant group if at least one specimen isolated from their respiratory secretions grew bacteria resistant or intermediate to all classes of antibiotics tested. Patients with sensitive or resistant B cepacia were excluded because of its adverse impact upon post-transplant survival. Forty-five of 103 (43.7%) patients harbored panresistant bacteria (43 had Pseudomonas aeruginosa, 1 had Stenotrophomonas maltophilia, and 1 had Achromobacter xylosoxidans). According to log-rank test, there was decreased survival in patients with panresistant bacteria compared to patients with sensitive bacteria (survival: 91.1 +/- 4.2% vs 98.3 +/- 1.7% at 3 months; 88.6 +/- 4.8% vs 96.6 +/- 2.4% at 1 year; 63.2 +/- 8.6% vs 90.7 +/- 4.0% at 3 years; 58.3 +/- 9.2% vs 85.6 +/- 5.2% at 5 years; p = 0.016). The results did not differ significantly between the two centers. Both groups had similar or better survival than CF patients as reported by the United Network of Organ Sharing (UNOS) registry (1-year, 86.0%; 3 years, 65.4%; 5 years, 49.6%). Patients with CF harboring panresistant bacteria have slightly decreased survival, but their survival is comparable to the results published by the UNOS registry.

Uso del sistema E-test per lo studio di combinazioni antibiotiche verso batteri Gram-negativi multiresistenti in Fibrosi Cistica

Objectives: Cystic Fibrosis patients are prone to infection by Gram-negative bacteria, such as Pseudomonas aeruginosa and Burkholderia cepacia, which become very resistant with recurrent antibiotic treatments.The purpose of this study was to evaluate the susceptibility patterns of 12 isolates of Burkholderia cepacia and 8 isolates of Pseudomonas aeruginosa, isolated from Cystic Fibrosis patients to five individual antibiotics (ceftazidime, ciprofloxacin, piperacillin/tazobactam, levofloxacin and trimethoprim-sulfamethoxazole) and to four antibiotic combinations (ceftazidime associated with one of the other antibiotics). Methods: Susceptibility tests were carried out using an agar diffusion method, the E-test (AB Biodisk, Solna, Sweden). Results: Strains were selected because of their resistance to individual antimicrobial agents, tested with automated system (Phoenix, BD), which ranged from 41.6% for ceftazidime to 83.3% for ciprofloxacin for Burkholderia cepacia and from 25% for ceftazidime to 100% for trimethoprim-sulfamethoxazole for Pseudomonas aeruginosa. By using E-test,we were able to demonstrate synergy against 2 strains of Pseudomonas aeruginosa (25%) with ceftazidime- piperacillin/tazobactam. No synergy was detected against all strains of Burkholderia cepacia. Conclusions:These results suggest that the E-test offers a simple, labour-efficient and accurate method for MIC determination on agar medium and the susceptibility to antibiotic combinations greatly improves the guide to antibiotic therapy for infections to Gram-negative bacteria in Cystic Fibrosis patients.

Microbiology of airway disease in a cohort of patients with Cystic Fibrosis

BackgroundRecent reports document an increasing incidence of new Gram-negative pathogens such as Stenotrophomonas maltophilia and Alcaligenes xylosoxidans isolated from patients with Cystic Fibrosis, along with an increase in common Gram-negative pathogens such as Pseudomonas aeruginosa and Burkholderia cepacia complex. Furthermore, the increase in multidrug-resistance of such organisms makes the therapeutic management of these patients more problematic. Therefore, careful isolation and identification, and accurate studies of susceptibility to antibiotics are critical for predicting the spread of strains, improving therapeutic measures and facilitating our understanding of the epidemiology of emerging pathogens. The first aim of this study was to determine the incidence and the prevalence of colonization by Gram-negative organisms isolated from respiratory samples of Cystic Fibrosis patients in the Regional Referral Cystic Fibrosis Centre of Naples; the second was to evaluate the spectrum of multidrug-resistance of these organisms.MethodsPatients (n = 300) attending the Regional Cystic Fibrosis Unit were enrolled in this study over 3 years. Sputum was processed for microscopic tests and culture. An automated system, Phoenix (Becton Dickinson, Sparks, Maryland, USA), was used for phenotypic identification of all strains; the API 20 NE identification system (bioMérieux, Marcy l'Etoile, France) was used when the identification with the Phoenix system was inaccurate. A PCR-RFLP method was used to characterize the organisms in the Burkholderia cepacia complex. A chemosusceptibility test on microbroth dilutions (Phoenix) was used. Primary outcomes such as FEV1 were correlate with different pathogens.ResultsDuring the period of study, 40% of patients was infected by Pseudomonas aeruginosa, 7% by Burkholderia cepacia complex, 11% by Stenotrophomonas maltophilia and 7% by Alcaligenes xylosoxidans. Of the strains isolated, 460 were multidrug-resistant. Multiresistant were Pseudomonas aeruginosa and Burkholderia cepacia complex.ConclusionThe results confirm previously reported data; in particular, they show an increase the isolation of non-fermentative Gram-negative bacteria in Cystic Fibrosis patients. They also demonstrate increased resistance to antibiotics. Beta-lactams are rarely effective, with exception of ceftazidime, which is the most efficacious agent against multiresistant strains. Aminoglycosides and quinolones are poorly efficacious.

Multiresistant non-fermentative gram-negative bacteria in cystic fibrosis patients: the results of an Italian multicenter study. Italian Group for Cystic Fibrosis microbiology.

We carried out an epidemiological study on 2717 patients seen on a regular basis at Italian Cystic Fibrosis Centers with the aim of defining the prevalence of multiresistant Gram-negative strains in Italy. We found 272 multiresistant strains out of 1560 Gram-negative strains isolated in 1012 Italian cystic fibrosis patients. From our results in Italian cystic fibrosis patients we may conclude: (1) the beta-lactam antibiotics are moderately active; ceftazidime is the most efficacious even if 59.9% of multiresistant strains are not sensitive to this drug; (2) the aminoglycosides are poorly efficacious; 93% of multiresistant strains are resistant in vitro to tobramycin; and (3) the quinolones, notwithstanding their relatively recent introduction into clinical practice, have very poor activity against multiresistant strains, 89.7% of which are not sensitive.

Pseudomonas Aeruginosa in Hospitalized Patients with Infective Exacerbations of Bronchiectasis: Clinical and Research Implications

<i>Pseudomonas Aeruginosa</i> in Hospitalized Patients with Infective Exacerbations of Bronchiectasis: Clinical and Research Implications

The effects of panresistant bacteria in cystic fibrosis patients on lung transplant outcome.

The number of cystic fibrosis (CF) patients undergoing lung transplant continues to rise as long term survival improves. One major contraindication to this potentially life-saving intervention is infection with multi-drug-resistant bacteria. We undertook this retrospective study in 66 transplanted patients over 6 yr to determine the influence of panresistant bacteria on transplant outcome. The in vitro antibiotic susceptibility pattern of respiratory tract bacteria obtained pre- and/or intraoperatively was used to categorize patients into panresistant (n = 27) (Burkholderia cepacia, n = 6, and Pseudomonas aeruginosa, n = 21) or sensitive (n = 39) groups. Postoperative ventilator days, hospital length of stay, and antibiotic days were similar for both groups (p > 0.2). The incidence of bacterial bronchitis (28% and 33%, respectively) and pneumonia (28% and 38%, respectively) did not differ between these groups (p > 0.2) at 6 mo. Likewise, one-year (81% and 83%, respectively) survival was similar for both groups (p > 0.2). As expected, panresistant B. cepacia patients had a lower 1-yr survival (50% versus 90%, p < 0.05) and had a higher mortality attributable to B. cepacia (50% versus 0%, p < 0.01) compared with panresistant P. aeruginosa patients. Our results indicate that CF patients infected with panresistant P. aeruginosa have similar transplant outcomes as patients with sensitive bacteria and should not be excluded from lung transplant based solely on this criterion.

308 TITERS OF SALIVARY IgA ANTIBODIES TO BACTERIAL ANTIGENS IN CYSTIC FIBROSIS WITH AND WITHOUT SEVERE MALNUTRTnON

Natural history of cystic fibrosis (CF) is marked by an increasing proneness to lung infections requiring long-term antibiotic therapy. Secretory IgA (SIgA) represent a major component of the mucosal defence system but they have been shown to be ineffective to prevent lung colonization from Pseudomonas Aeruginosa in CF. Little is known however about secretory immunity to common bacteria in CF patients.

Predictive Value of Oropharyngeal Cultures for Identifying Lower Airway Bacteria in Cystic Fibrosis Patients

Identifying lower respiratory pathogens in young, non expectorating cystic fibrosis (CF) patients has been problematic. Bronchial secretions are difficult to obtain, and little is known about lower airway flora in these patients. We collected simultaneous bronchial and oropharyngeal specimens in 43 CF patients in optimal respiratory status, including both expectorating (17) and nonexpectorating (26) patients, to determine the predictive value of oropharyngeal cultures for identifying lower airway pathogens. An additional goal was to characterize the lower respiratory flora of these patients. Predictive values were defined as the proportion of oropharyngeal culture results that accurately reflected the results of bronchial cultures. Predictive values of positive oropharyngeal cultures in nonexpectorating patients were 83% (95% confidence interval 36 to 100%) for Pseudomonas aeruginosa and 91% (59 to 100%) for Staphylococcus aureus. Predictive values of negative oropharyngeal cultures were lower: 70% (48 to 86%) for R aeruginosa and 80% (52 to 96%) for S. aureus. A relatively high proportion of nonexpectorating CF patients less than 10 yr old had R aerusginosa (11 of 24, 46%) or Klebsiella species (5 of 24, 21%) in their lower airways. The isolation of Klebsiella was associated with younger age (p = 0.03) and recent administration of antistaphylococcal antibiotics (p = 0.05). Our results suggest that oropharyngeal cultures yielding R aeruginosa or S. aureus are highly predictive, but such cultures lacking these organisms do not rule out the presence of these pathogens in the lower airways of CF patients.

Defective cellular immunity to gram-negative bacteria in cystic fibrosis patients

In vitro lymphocyte responses to Pseudomonas aeruginosa have been found to be impaired in cystic fibrosis patients with advanced clinical disease. The responses to Klebsiella pneumoniae, Serratia marcescens, and Proteus mirabilis were studied in a similar group of cystic fibrosis patients and normal individuals. Cystic fibrosis patients found to be unresponsive to pseudomonas were also unresponsive to klebsiella, serratia, and proteus. Responsiveness to Staphylococcus aureus was not impaired in cystic fibrosis patients. We postulate that in vitro lymphocyte responses to several gram-negative bacteria require the function of a lymphocyte subpopulation which may be impaired in some cystic fibrosis patients.