Comparison of antibiotic susceptibility patterns in Pseudomonas aeruginosa isolated from adult patients with cystic fibrosis (CF) with invasive Pseudomonas aeruginosa from non-CF patients

Abstract

The role of bacterial pathogens in CF pulmonary disease contributes greatly to the morbidity and mortality in patients with CF. CF patients have recurrent and chronic respiratory tract infections and most of their morbidity and mortality is due to such infections throughout their life [1,2]. These infections are usually dominated by non-fermenting Gram-negative organisms (Burkholderia cenocepacia and Stenotrophomonas maltophilia), including Pseudomonas aeruginosa. P. aeruginosa is the single most important pathogen in this patient population. Recent advances in treatment, which include intensive physiotherapy and aggressive antibiotic treatment, have greatly improved the outlook for patients. However, with the improvement in survival rates in CF patients, a new range of pulmonary issues have arisen. These include the emergence of multi-drug resistant strains of P. aeruginosa [3] and the appearance of organisms with increased virulence such as the Burkholderia cepacia complex (BCC).There are approximately 283 adult CF patients in Northern Ireland (NI) with CF, where they receive regional CF centrebased multidisciplinary care at the Regional Adult Cystic Fibrosis Centre, Belfast City Hospital.At present, the UK CF Registry, which is compiled by the CF Trust [4], includes data on the presence of respiratory pathogens, but does not include any information on antibiotic susceptibility of colonising/infection respiratory pathogens, including P. aeruginosa. A study was therefore undertaken locally to evaluate current levels of antimicrobial susceptibility in adult CF patients who were infected with P. aeruginosa and to compare levels of antibiotic susceptibility, with a comparator non-CF population of invasive P. aeruginosa, isolated from blood culture material.One hundred and twenty seven adult patients (approximately. 61.7% of total adult CF patients in NI) with a confirmed clinical diagnosis of CF were included in the study. There were 72 males and 55 females, with an age range of 19-82 years and 18-61 years, respectively. Of the 127 patients with a documented history of P. aeruginosa infection, P. aeruginosa isolates were selected as part of the routine microbiological workup, which included the selection of isolates which were morphologically different, including those which were mucoid. From these, 99 were nonmucoid, 26 were mucoid and 2 were mixed (mucoid + nonmucoid). Antibiotic susceptibility profiles of the most recent P. aeruginosa isolate were examined and antibiotic susceptibility noted against the following four antibiotic classes [11 agents]: aminoglycosides [

Comparison of virulence factors and antibiotic resistance of Pseudomonas aeruginosa strains isolated from patients with and without cystic fibrosis

“…Similar results were also obtained in another Turkish multi-center study comparing the antibiotic resistance of P.aeruginosa isolates from sputum samples of patients with CF and lower respiratory tract samples of patients without CF (24). In contrary to this Rao et al showed that isolates from blood samples of CF patients were more resistant to antibiotics than those of non-CF patients (25). It may be because of several classes of antibiotics used in the management of CF airways infection.…”

Ciprofloxacin DPI: a randomised, placebo-controlled, phase IIb efficacy and safety study on cystic fibrosis

“… 24 Because the relevance of organism antibiotic sensitivity patterns has been questioned in recent years, the use of two antibiotics with different mechanisms of action to improve outcome is still common practice in most CF centres. 25 …”

Antibiotic resistance evolution of Pseudomonas aeruginosa in cystic fibrosis patients (2010‐2013)

“…Antibiotic resistance is a significant and increasing problem in medical practice and a common clinical complication in CF patients infected with P aeruginosa , which tends to present more resistance than P aeruginosa from non‐CF patients to all clinically relevant classes of antibiotics …”

“…This fact seems to reflect the chronic burden of antibiotic exposure usually present in CF treatment …”