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Microbiology Spectrum Aug 2023is a genus of Gram-negative rods, which can cause persistent airway infections in people with cystic fibrosis (CF). The knowledge about virulence and clinical...
is a genus of Gram-negative rods, which can cause persistent airway infections in people with cystic fibrosis (CF). The knowledge about virulence and clinical implications of is still limited, and it is not fully established whether infections contribute to disease progression or if it is a marker of poor lung function. The most commonly reported species in CF is A. xylosoxidans. While other spp. are also identified in CF airways, the currently used Matrix-Assisted Laser Desorption/Ionization Time Of Flight Mass Spectrometry (MALDI-TOF MS) method in routine diagnostics cannot distinguish between species. Differences in virulence between species have consequently not been well studied. In this study, we compare phenotypes and proinflammatory properties of A. xylosoxidans, , , and using models. Bacterial supernatants were used to stimulate CF bronchial epithelial cells and whole blood from healthy individuals. Supernatants from the well-characterized CF-pathogen Pseudomonas aeruginosa were included for comparison. Inflammatory mediators were analyzed with ELISA and leukocyte activation was assessed using flow cytometry. The four species differed in morphology seen in scanning electron microscopy (SEM), but there were no observed differences in swimming motility or biofilm formation. Exoproducts from all species except caused significant IL-6 and IL-8 secretion from CF lung epithelium. The cytokine release was equivalent or stronger than the response induced by P. aeruginosa. All species activated neutrophils and monocytes in a lipopolysaccharide (LPS)-independent manner. Our results indicate that exoproducts of the four included species do not differ consistently in causing inflammatory responses, but they are equally or even more capable of inducing inflammation compared with the classical CF pathogen P. aeruginosa. Achromobacter xylosoxidans is an emerging pathogen among people with cystic fibrosis (CF). Current routine diagnostic methods are often unable to distinguish A. xylosoxidans from other species, and the clinical relevance of different species is still unknown. In this work, we show that four different species relevant to CF evoke similar inflammatory responses from airway epithelium and leukocytes , but they are all equally or even more proinflammatory compared to the classic CF-pathogen Pseudomonas aeruginosa. The results suggest that species are important airway pathogens in CF, and that all species are relevant to treat.
Topics: Humans; Achromobacter; Cystic Fibrosis; Gram-Negative Bacterial Infections; Achromobacter denitrificans; Lung
PubMed: 37284754
DOI: 10.1128/spectrum.00195-23 -
Journal of Cystic Fibrosis : Official... Dec 2013Achromobacter species leads to chronic infection in an increasing number of CF patients. We report 2 cases of Achromobacter ruhlandii cross-infection between patients...
BACKGROUND AND METHODS
Achromobacter species leads to chronic infection in an increasing number of CF patients. We report 2 cases of Achromobacter ruhlandii cross-infection between patients after well-described indirect contact.
RESULTS
Both cases were young, stable, CF patients without chronic infections and with normal FEV1, but experienced clinical deterioration after visits to the home of a CF patient with A. ruhlandii infection and after sharing facilities with an A. ruhlandii infected CF patient on a skiing vacation, respectively. Both cases became positive for A. ruhlandii in airway secretions and were colonized with A. ruhlandii in their sinuses. Aggressive, long-term antibiotic treatment led to clinical stability. One of the cases developed chronic A. ruhlandii infection.
CONCLUSION
A. species can cause cross-infection even after a short period of indirect contact between infected and non-infected CF patients. Patients should be followed closely for several months before the possibility of cross-infection is ruled out.
Topics: Achromobacter; Adolescent; Bacterial Typing Techniques; Cystic Fibrosis; Electrophoresis, Gel, Pulsed-Field; Female; Gram-Negative Bacterial Infections; Humans; Male; Multilocus Sequence Typing; Paranasal Sinuses; Sputum
PubMed: 23769270
DOI: 10.1016/j.jcf.2013.05.004 -
International Journal of Medical... Feb 2020Bacteria colonising the lungs of cystic fibrosis (CF) patients encounter high selective pressures. Hypermutation facilitates adaptation to fluctuating environments, and...
Bacteria colonising the lungs of cystic fibrosis (CF) patients encounter high selective pressures. Hypermutation facilitates adaptation to fluctuating environments, and hypermutator strains are frequently isolated from CF patients. We investigated the prevalence of hypermutator isolates of Achromobacter spp. among patients affiliated with the CF Centre in Aarhus, Denmark. By exposure to rifampicin, the mutation frequency was determined for 90 isolates of Achromobacter spp. cultured from 42 CF patients; 20 infections were categorised as chronic, 22 as intermittent. The genetic mechanisms of hypermutation were examined by comparing DNA repair gene sequences from hypermutator and normomutator isolates. Achromobacter spp. cultured from 11 patients were categorised as hypermutators, and this phenotype was exclusively associated with chronic infections. Isolates of the Danish epidemic strain (DES) of Achromobacter ruhlandii cultured from patients from both Danish CF centres showed elevated mutation frequencies. The hypermutator state of Achromobacter spp. was most commonly associated with nonsynonymous mutations in the DNA mismatch repair gene mutS; a single clone had developed a substitution in the S-adenosyl-L-methionine-dependent methyltransferase putatively involved in DNA repair mechanisms, but not previously linked to the hypermutator phenotype. Hypermutation is prevalent among clinical isolates of Achromobacter spp. and could be a key determinant for the extraordinary adaptation and persistence of DES.
Topics: Achromobacter; Anti-Bacterial Agents; Chronic Disease; Cystic Fibrosis; DNA Mismatch Repair; Denmark; Humans; MutS DNA Mismatch-Binding Protein; Mutation; Mutation Rate; Phenotype; Prevalence; Rifampin
PubMed: 31969255
DOI: 10.1016/j.ijmm.2020.151393 -
Journal of Clinical Microbiology May 2013A new blaOXA-258 gene is described as a species-specific taxonomic marker for Achromobacter ruhlandii isolates (all recovered from cystic fibrosis patients). Even though...
A new blaOXA-258 gene is described as a species-specific taxonomic marker for Achromobacter ruhlandii isolates (all recovered from cystic fibrosis patients). Even though OXA-258 differs from OXA-114 variants, isolates could be misidentified as A. xiloxosidans by the amplification of an inner fragment from the OXA-coding gene. A robust identification of A. ruhlandii can be achieved by sequencing this single OXA gene, as well as by a more laborious recently proposed multilocus sequence-typing (MLST) scheme.
Topics: Achromobacter; Amino Acid Sequence; Base Sequence; Genes, Bacterial; Genetic Markers; Gram-Negative Bacterial Infections; Humans; Molecular Sequence Data; Multilocus Sequence Typing; RNA, Ribosomal, 16S; beta-Lactamases
PubMed: 23467601
DOI: 10.1128/JCM.03043-12 -
BMC Microbiology Jun 2023Klebsiella pneumoniae is one of the main pathogens of clinical isolation and nosocomial infections, as K. pneumoniae show broad-spectrum resistance to β-lactam and...
BACKGROUND
Klebsiella pneumoniae is one of the main pathogens of clinical isolation and nosocomial infections, as K. pneumoniae show broad-spectrum resistance to β-lactam and carbapenem antibiotics. It is emerging clinical need for a safe and effective drug to anti-K. pneumoniae. At present, Achromobacter mainly focused on its degradation of petroleum hydrocarbons, polycyclic aromatic hydrocarbons, assisting insects to decompose, degrade heavy metals and utilize organic matter, but there were few reports on the antibacterial activity of the secondary metabolites of Achromobacter.
RESULTS
In this study, a strain WA5-4-31 from the intestinal tract of Periplaneta americana exhibited strong activity against K. Pneumoniae through preliminary screening. The strain was determined to be Achromobacter sp. through the morphological characteristics, genotyping and phylogenetic tree analysis, which is homologous to Achromobacter ruhlandii by 99%, its accession numbe in GenBank at National Center for Biotechnology Information (NCBI) is MN007235, and its deposit number was GDMCC NO.1.2520. Six compounds (Actinomycin D, Actinomycin X2, Collismycin A, Citrinin, Neoechinulin A and Cytochalasin E) were isolated and determined by activity tracking, chemical separation, nuclear magnetic resonance (NMR) and mass spectrometry (MS) analysis. Among them, Actinomycin D, Actinomycin X2, Collismycin A, Citrinin and Cytochalasin E showed a good effect on anti-K. pneumoniae, with MIC values of 16-64 µg/mL.
CONCLUSIONS
The study reported Achromobacter, which was from the intestinal tract of Periplaneta americana with the activity against K. Pneumoniae, can produce antibacterial compounds for the first time. It lays the foundation for development of secondary metabolites of insect intestinal microorganisms.
Topics: Animals; Periplaneta; Dactinomycin; Citrinin; Klebsiella pneumoniae; Phylogeny; Secondary Metabolism; Anti-Bacterial Agents; Achromobacter; Intestines; Klebsiella Infections; Microbial Sensitivity Tests; beta-Lactamases
PubMed: 37277707
DOI: 10.1186/s12866-023-02909-7 -
Antimicrobial Agents and Chemotherapy Oct 2020spp. are recognized as emerging pathogens in patients with cystic fibrosis (CF). Though recent works have established species-level identification using sequencing,...
spp. are recognized as emerging pathogens in patients with cystic fibrosis (CF). Though recent works have established species-level identification using sequencing, there is a dearth in knowledge relating to species-level antimicrobial susceptibility patterns and antimicrobial combinations, which hampers the use of optimal antimicrobial combinations for the treatment of chronic infections. The aims of this study were to (i) identify at species-level referred isolates, (ii) describe species-level antimicrobial susceptibility profiles, and (iii) determine the most promising antimicrobial combination for chronic infections. A total of 112 multidrug-resistant (MDR) species isolates from 39 patients were identified using sequencing. Antimicrobial susceptibility and combination testing were carried out using the Etest method. We detected six species of and found that was the most prevalent species. Interestingly, sequence analysis showed it was responsible for persistent infection (18/28 patients), followed by (2/3 patients). Piperacillin-tazobactam (70.27%) and co-trimoxazole (69.72%) were the most active antimicrobials. Differences were observed in species-level susceptibility to ceftazidime, carbapenems, ticarcillin-clavulanate, and tetracycline. Antimicrobial combinations with co-trimoxazole or tobramycin demonstrate the best synergy, while co-trimoxazole gave the best susceptibility breakpoint index values. This study enriches the understanding of MDR spp. epidemiology and confirms prevalence and chronic colonization of in CF lungs. It presents data to support the efficacy of new combinations for use in the treatment of chronic infections.
Topics: Achromobacter; Achromobacter denitrificans; Anti-Bacterial Agents; Cystic Fibrosis; Gram-Negative Bacterial Infections; Humans; Microbial Sensitivity Tests
PubMed: 32816722
DOI: 10.1128/AAC.01467-20 -
Genome Biology and Evolution Apr 2017Over the past decade, there has been a rising interest in Achromobacter sp., an emerging opportunistic pathogen responsible for nosocomial and cystic fibrosis lung...
Over the past decade, there has been a rising interest in Achromobacter sp., an emerging opportunistic pathogen responsible for nosocomial and cystic fibrosis lung infections. Species of this genus are ubiquitous in the environment, can outcompete resident microbiota, and are resistant to commonly used disinfectants as well as antibiotics. Nevertheless, the Achromobacter genus suffers from difficulties in diagnosis, unresolved taxonomy and limited understanding of how it adapts to the cystic fibrosis lung, not to mention other host environments. The goals of this first genus-wide comparative genomics study were to clarify the taxonomy of this genus and identify genomic features associated with pathogenicity and host adaptation. This was done with a widely applicable approach based on pan-genome analysis. First, using all publicly available genomes, a combination of phylogenetic analysis based on 1,780 conserved genes with average nucleotide identity and accessory genome composition allowed the identification of a largely clinical lineage composed of Achromobacter xylosoxidans, Achromobacter insuavis, Achromobacter dolens, and Achromobacter ruhlandii. Within this lineage, we identified 35 positively selected genes involved in metabolism, regulation and efflux-mediated antibiotic resistance. Second, resistome analysis showed that this clinical lineage carried additional antibiotic resistance genes compared with other isolates. Finally, we identified putative mobile elements that contribute 53% of the genus's resistome and support horizontal gene transfer between Achromobacter and other ecologically similar genera. This study provides strong phylogenetic and pan-genomic bases to motivate further research on Achromobacter, and contributes to the understanding of opportunistic pathogen evolution.
PubMed: 28383665
DOI: 10.1093/gbe/evx061 -
Journal of Cystic Fibrosis : Official... May 2013We recently described a multilocus sequence typing scheme for Achromobacter that identified several novel species in this genus.
BACKGROUND
We recently described a multilocus sequence typing scheme for Achromobacter that identified several novel species in this genus.
METHODS
We assessed the ability of nrdA sequence analysis to differentiate Achromobacter species, including the seven previously named species and 14 recently described genogroups. Confirmation of distinctness between groups was confirmed using the k parameter. Using this single locus sequence to differentiate species, we analyzed Achromobacter isolates obtained from 341 CF patients in the U.S.
RESULTS
We found that Achromobacter xylosoxidans accounts for 42% of Achromobacter infections, while Achromobacter ruhlandii accounted for 23.5% of infections. Isolates from 17% of patients were members of the novel genogroup 14. The remaining 17.5% of strains belonged to 11 other species/genogroups.
CONCLUSION
The use of nrdA sequence analysis allows differentiation of the several Achromobacter species that can infect persons with CF. Achromobacter species other than A. xylosoxidans account for the majority of Achromobacter infection in CF patients in the U.S.
Topics: Achromobacter; Bacterial Proteins; Cystic Fibrosis; DNA, Bacterial; Humans
PubMed: 23141756
DOI: 10.1016/j.jcf.2012.10.002 -
Journal of Clinical Microbiology Aug 2012A multilocus sequence analysis (MLSA) scheme was developed for characterization of strains and species from the genus Achromobacter, which are increasingly recovered...
A multilocus sequence analysis (MLSA) scheme was developed for characterization of strains and species from the genus Achromobacter, which are increasingly recovered from patients with cystic fibrosis (CF). Five conserved housekeeping genes were selected for the MLSA, which was applied to a diverse collection of 77 strains originating from Europe, Asia, and South America and including type strains of the seven recognized Achromobacter species, six environmental strains, eight non-CF clinical strains, and 56 CF clinical strains. The discriminatory power of MLSA, based on 2,098 nucleotides (nt), was much superior to a 16S rRNA gene comparison based on 1,309 nt. Congruence was observed between single-gene trees and a concatenated gene tree. MLSA differentiated all seven current Achromobacter species and also demonstrated the presence of at least four novel potential species within the genus. CF isolates were predominantly Achromobacter xylosoxidans (64%), an undescribed Achromobacter species (18%), and Achromobacter ruhlandii (7%). A clone of Achromobacter, which has spread among patients from Danish CF centers in Aarhus and Copenhagen, was identified as Achromobacter ruhlandii. MLSA facilitates the specific identification of isolates of Achromobacter necessary for describing their role in clinical infections.
Topics: Achromobacter; Asia; Cluster Analysis; Cystic Fibrosis; Environmental Microbiology; Europe; Genotype; Gram-Negative Bacterial Infections; Humans; Molecular Sequence Data; Multilocus Sequence Typing; South America
PubMed: 22675125
DOI: 10.1128/JCM.00728-12 -
Journal of Clinical Microbiology Dec 2015Molecular methodologies were used to identify 28 Achromobacter spp. from patients with cystic fibrosis (CF). Multilocus sequence typing (MLST) identified 17...
Characterization of Achromobacter Species in Cystic Fibrosis Patients: Comparison of bla(OXA-114) PCR Amplification, Multilocus Sequence Typing, and Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry.
Molecular methodologies were used to identify 28 Achromobacter spp. from patients with cystic fibrosis (CF). Multilocus sequence typing (MLST) identified 17 Achromobacter xylosoxidans isolates (all bla(OXA-114) positive), nine Achromobacter ruhlandii isolates (all bla(OXA-114) positive), one Achromobacter dolens isolate, and one Achromobacter insuavis isolate. All less common species were misidentified as A. xylosoxidans by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Chronic colonization by clonally related A. ruhlandii isolates was demonstrated.
Topics: Achromobacter; Cystic Fibrosis; Gram-Negative Bacterial Infections; Humans; Multilocus Sequence Typing; Polymerase Chain Reaction; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; beta-Lactamases
PubMed: 26400790
DOI: 10.1128/JCM.02197-15