Uncovering Differences in Virulence Markers Associated with Achromobacter Species of CF and Non-CF Origin

Abstract

Achromobacter spp. are recognized as emerging pathogens in hospitalized as well as in cystic fibrosis (CF) patients. From 2012 to 2015, we collected 69 clinical isolates (41 patient) of Achromobacter spp. from 13 patients with CF (CF isolates, n = 32) and 28 patients receiving care for other health conditions (non-CF isolates, n = 37). Molecular epidemiology and virulence potential of isolates were examined. Antimicrobial susceptibility, motility, ability to form biofilms and binding affinity to mucin, collagen, and fibronectin were tested to assess their virulence traits. The nrdA gene sequencing showed that A. xylosoxidans was the most prevalent species in both CF and non-CF patients. CF patients were also colonized with A. dolens/A. ruhlandii, A. insuavis, and A. spiritinus strains while non-CF group was somewhat less heterogenous, although A. insuavis, A. insolitus, and A. piechaudii strains were detected beside A. xylosoxidans. Three strains displayed clonal distribution, one among patients from the CF group and two among non-CF patients. No significant differences in susceptibility to antimicrobials were observed between CF and non-CF patients. About one third of the isolates were classified as strong biofilm producers, and the proportion of CF and non-CF isolates with the ability to form biofilm was almost identical. CF isolates were less motile compared to the non-CF group and no correlation was found between swimming phenotype and biofilm formation. On the other hand, CF isolates exhibited higher affinity to bind mucin, collagen, and fibronectin. In generall, CF isolates from our study exhibited in vitro properties that could be of importance for the colonization of CF patients.

Antimicrobial susceptibility of non-fermenting Gram-negative pathogens isolated from cystic fibrosis patients

“…The most active agents for Achromobacter were SXT and IMI. In contrast to previously published data, MER was less active than IMI [16]. CAZ, COL, and TOB have been considered adequate for inhalation therapy [17]; however, in this study, these antibiotics presented high MIC 90 values.…”

“…Some studies have demonstrated that its presence is associated with a risk of pulmonary exacerbation but not with a worsened long-term prognosis [15]. Also, Achromobacter isolated from people with CF seem to be more virulent than those isolated from other sources [16]. The most active agents for Achromobacter were SXT and IMI.…”

Microbiology of Cystic Fibrosis Airway Disease

“…Achromobacter species are motile due to the presence of flagella, and can exhibit binding factors to mucin, collagen, and fibronectin, thereby facilitating initial attachment and invasion of the respiratory tract. 82,83 Biofilm formation as well as intrinsic resistance to several classes of antimicrobials through the expression of efflux pumps, βlactamases, and aminoglycoside-modifying enzymes [84][85][86] is also expressed by this group of pathogens.…”

Characterization of Novel Lytic Bacteriophages of Achromobacter marplantensis Isolated from a Pneumonia Patient

“…The recent review of genetic divergence within the Achromobacter genus resulted in an increase in the number of recorded strains of A. marplatensis , owing to the reclassification of A. spiritinus as A. marplatensis [ 15 , 16 ]. A. marplatensis now carries a newly recognised importance in CF patients, being isolated from more than 10% of patients in a French CF Centre [ 12 ], as well as in CF patients in Argentina [ 17 ], Serbia [ 18 ], Denmark [ 19 ] and the UK [ 20 ].…”