Distribution of innate efflux-mediated aminoglycoside resistance among different Achromobacter species

Comparative phenotypic and genotypic antimicrobial susceptibility surveillance in Achromobacter spp. through whole genome sequencing

Treatment of Achromobacter infections remains challenging due to intrinsic and acquired resistance to commonly used antimicrobial agents and no established clinical breakpoints. We attempted accurate species-level identification and compared the presence of genotypic resistance markers to phenotypic susceptibility patterns in retrospectively collected clinical isolates of Achromobacter spp. Our study concludes that Achromobacter xylosoxidans is the most prevalent species. Commercial matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) systems cannot accurately identify all Achromobacter species due to the limited inclusion of spectra in the databases. Phenotypic antimicrobial susceptibility testing (AST) confirms resistance to the majority of antibiotics tested. Newer agents like delafloxacin, plazomicin, and omadacycline showed little or no activity, while minimum inhibitory concentrations were low for eravacycline. In general, the species other than A. xylosoxidans showed lower MIC50 and MIC90, especially to carbapenems and β-lactamase inhibitor combinations like piperacillin-tazobactam, meropenem-vaborbactam, and imipenem-relebactam. Genotypic analysis confirmed that A. xylosoxidans carries a high number of resistance genes, including multidrug efflux pump AxyXY-OprZ, several class D (OXA-type), and the Class A ß-lactamase blaAXC, while Achromobacter mucicolens has the lowest number of resistance genes and no efflux pumps. This study concludes that there is significant genotypic and phenotypic diversity within the different species of Achromobacter, which are important for the identification of the species and for appropriate antimicrobial therapy.IMPORTANCEIdentification and susceptibility testing of Gram-negative non-fermenting bacteria belonging to the genus Achromobacter is difficult due to the lack of robust databases in commercial identification systems such as matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and clinical breakpoints for antimicrobial agents. Most clinical laboratories interpret minimum inhibitory concentration data using the "non-Enterobacterales" breakpoints included in the Clinical and Laboratory Standards Institute (CLSI) M100. These are breakpoints used for a group of organisms for which data is insufficient to provide species-specific interpretation. Our study provides phenotypic data regarding identification and susceptibility testing and correlates this with the genotypic characterization of 109 clinical isolates belonging to Achromobacter spp. This comprehensive study sheds light on the phenotypic and genotypic character of this bacteria, that is of increasing clinical relevance in hospital-acquired infections.

Genetic and Biochemical Characterization of AXC-2 from Achromobacter ruhlandii

Achromobacter spp. are intrinsically resistant to multiple antibiotics and can also acquire resistance to those commonly used for the treatment of respiratory infections, especially in patients with cystic fibrosis. The aim of this study was to perform the genetic and biochemical characterization of AXC-2 from A. ruhlandii and to analyze all available AXC variants. Steady-state kinetic parameters were determined on a purified AXC-2 enzyme. It exhibited higher catalytic efficiencies towards amino-penicillins and older cephalosporins, while carbapenems behaved as poor substrates. Phylogenetic analysis of all blaAXC variants available in the NCBI was conducted. AXC was encoded in almost all A. ruhlandii genomes, whereas it was only found in 30% of A. xylosoxidans. AXC-1 was prevalent among A. xylosoxidans. AXC variants were clustered in two main groups, correlating with the Achromobacter species. No association could be established between the presence of blaAXC variants and a specific lineage of A. xylosoxidans; however, a proportion of AXC-1-producing isolates corresponded to ST 182 and ST 447. In conclusion, this study provides valuable insights into the genetic context and kinetic properties of AXC-2, identified in A. ruhlandii. It also provides a thorough description of all AXC variants and their association with Achromobacter species and various lineages.

Atypical microbial keratitis

Atypical microbial keratitis refers to corneal infections caused by micro-organisms not commonly encountered in clinical practice. Unlike infections caused by common bacteria, cases of atypical microbial keratitis are often associated with worse clinical outcomes and visual prognosis. This is due to the challenges in the identification of causative organisms with standard diagnostic techniques, resulting in delays in the initiation of appropriate therapies. Furthermore, due to the comparatively lower incidence of atypical microbial keratitis, there is limited literature on effective management strategies for some of these difficult to manage corneal infections. This review highlights the current management and available evidence of atypical microbial keratitis, focusing on atypical mycobacteria keratitis, nocardia keratitis, achromobacter keratitis, and pythium keratitis. It will also describe the management of two uncommonly encountered conditions, infectious crystalline keratopathy and post-refractive infectious keratitis. This review can be used as a guide for clinicians managing patients with such challenging corneal infections.

Role of Efflux in Antibiotic Resistance of Achromobacter xylosoxidans and Achromobacter insuavis Isolates From Patients With Cystic Fibrosis

Achromobacter genus (including Achromobacter xylosoxidans, the most prevalent Achromobacter species in patients with cystic fibrosis) is poorly susceptible to most conventional antibiotics. Contribution of efflux by AxyABM, AxyXY-OprZ, and AxyEF-OprN and of target mutations were studied in clinical isolates of A. xylosoxidans and Achromobacter insuavis. Forty-one isolates longitudinally collected from 21 patients with CF were studied by whole-genome sequencing (WGS)-typing, determination of minimum inhibitory concentrations (MICs) of β-lactams, aminoglycosides, colistin, azithromycin, ciprofloxacin, chloramphenicol, and doxycycline, and expression (quantitative RT-PCR) and function (measure of the uptake of a fluorescent substrate) of efflux pumps. WGS-based typing resulted in 10 clusters comprising 2 or 3 isolates and 20 singletons. The efflux activity was high in strains with elevated MICs for amikacin or azithromycin. This work sheds a new light on the impact of efflux and target mutations in resistance of Achromobacter to several drugs.

Role of RND Efflux Pumps in Drug Resistance of Cystic Fibrosis Pathogens

Drug resistance represents a great concern among people with cystic fibrosis (CF), due to the recurrent and prolonged antibiotic therapy they should often undergo. Among Multi Drug Resistance (MDR) determinants, Resistance-Nodulation-cell Division (RND) efflux pumps have been reported as the main contributors, due to their ability to extrude a wide variety of molecules out of the bacterial cell. In this review, we summarize the principal RND efflux pump families described in CF pathogens, focusing on the main Gram-negative bacterial species (Pseudomonas aeruginosa, Burkholderia cenocepacia, Achromobacter xylosoxidans, Stenotrophomonas maltophilia) for which a predominant role of RND pumps has been associated to MDR phenotypes.

Fluoroquinolone resistance in Achromobacter spp.: substitutions in QRDRs of GyrA, GyrB, ParC and ParE and implication of the RND efflux system AxyEF-OprN

BACKGROUND

Achromobacter are emerging pathogens in cystic fibrosis patients. Mechanisms of resistance to fluoroquinolones are unknown in clinical isolates. Among non-fermenting Gram-negative bacilli, fluoroquinolone resistance is mostly due to amino acid substitutions in localized regions of the targets (GyrA, GyrB, ParC and ParE) named QRDRs, but also to efflux.

OBJECTIVES

To explore quinolone resistance mechanisms in Achromobacter.

METHODS

The putative QRDRs of GyrA, GyrB, ParC and ParE were sequenced in 62 clinical isolates, and in vitro one-step mutants obtained after exposure to fluoroquinolones. An in vitro mutant and its parental isolate were investigated by RNASeq and WGS. RT-qPCR and gene inactivation were used to explore the role of efflux systems overexpression.

RESULTS

We detected seven substitutions in QRDRs (Q83L/S84P/D87N/D87G for GyrA, Q480P for GyrB, T395A/K525Q for ParE), all in nine of the 27 clinical isolates with ciprofloxacin MIC ≥16 mg/L, whereas none among the in vitro mutants. The RND efflux system AxyEF-OprN was overproduced (about 150-fold) in the in vitro mutant NCF-39-Bl6 versus its parental strain NCF-39 (ciprofloxacin MICs 64 and 1.5 mg/L, respectively). A substitution in AxyT (putative regulator of AxyEF-OprN) was detected in NCF-39-Bl6. Ciprofloxacin MIC in NCF-39-Bl6 dropped from 64 to 1.5 mg/L following gene inactivation of either axyT or axyF. Substitutions in AxyT associated with overexpression of AxyEF-OprN were also detected in seven clinical strains with ciprofloxacin MIC ≥16 mg/L.

CONCLUSIONS

Target alteration is not the primary mechanism involved in fluoroquinolone resistance in Achromobacter. The role of AxyEF-OprN overproduction was demonstrated in one in vitro mutant.

Achromobacter xylosoxidans and Stenotrophomonas maltophilia: Emerging Pathogens Well-Armed for Life in the Cystic Fibrosis Patients' Lung

In patients with cystic fibrosis (CF), the lung is a remarkable ecological niche in which the microbiome is subjected to important selective pressures. An inexorable colonization by bacteria of both endogenous and environmental origin is observed in most patients, leading to a vicious cycle of infection-inflammation. In this context, long-term colonization together with competitive interactions among bacteria can lead to over-inflammation. While Pseudomonas aeruginosa and Staphylococcus aureus, the two pathogens most frequently identified in CF, have been largely studied for adaptation to the CF lung, in the last few years, there has been a growing interest in emerging pathogens of environmental origin, namely Achromobacter xylosoxidans and Stenotrophomonas maltophilia. The aim of this review is to gather all the current knowledge on the major pathophysiological traits, their supporting mechanisms, regulation and evolutionary modifications involved in colonization, virulence, and competitive interactions with other members of the lung microbiota for these emerging pathogens, with all these mechanisms being major drivers of persistence in the CF lung. Currently available research on A. xylosoxidans complex and S. maltophilia shows that these emerging pathogens share important pathophysiological features with well-known CF pathogens, making them important members of the complex bacterial community living in the CF lung.

Achromobacter Infections and Treatment Options

Achromobacter is a genus of nonfermenting Gram-negative bacteria under order Burkholderiales Although primarily isolated from respiratory tract of people with cystic fibrosis, Achromobacter spp. can cause a broad range of infections in hosts with other underlying conditions. Their rare occurrence and ever-changing taxonomy hinder defining their clinical features, risk factors for acquisition and adverse outcomes, and optimal treatment. Achromobacter spp. are intrinsically resistant to several antibiotics (e.g., most cephalosporins, aztreonam, and aminoglycosides), and are increasingly acquiring resistance to carbapenems. Carbapenem resistance is mainly caused by multidrug efflux pumps and metallo-β-lactamases, which are not expected to be overcome by new β-lactamase inhibitors. Among the other new antibiotics, cefiderocol, and eravacycline were used as salvage therapy for a limited number of patients with Achromobacter infections. In this article, we aim to give an overview of the antimicrobial resistance in Achromobacter species, highlighting the possible place of new antibiotics in their treatment.

Longitudinal Surveillance and Combination Antimicrobial Susceptibility Testing of Multidrug-Resistant Achromobacter Species from Cystic Fibrosis Patients

Achromobacter spp. are recognized as emerging pathogens in patients with cystic fibrosis (CF). Though recent works have established species-level identification using nrdA 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 Achromobacter isolates, (ii) describe species-level antimicrobial susceptibility profiles, and (iii) determine the most promising antimicrobial combination for chronic Achromobacter infections. A total of 112 multidrug-resistant (MDR) Achromobacter species isolates from 39 patients were identified using nrdA sequencing. Antimicrobial susceptibility and combination testing were carried out using the Etest method. We detected six species of Achromobacter and found that Achromobacter xylosoxidans was the most prevalent species. Interestingly, sequence analysis showed it was responsible for persistent infection (18/28 patients), followed by Achromobacter ruhlandii (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 Achromobacter spp. epidemiology and confirms prevalence and chronic colonization of A. xylosoxidans in CF lungs. It presents in vitro data to support the efficacy of new combinations for use in the treatment of chronic Achromobacter infections.

Development of a database for the rapid and accurate routine identification of Achromobacter species by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS)

OBJECTIVES

Achromobacter spp. are emerging pathogens in respiratory samples from cystic fibrosis patients. The current reference methods (nrdA-sequencing or multilocus sequence typing) can identify 18 species which are often misidentified by conventional techniques as A. xylosoxidans. A few studies have suggested that matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF/MS) provides accurate identification of the genus but not of species. The aims of this study were (a) to generate a database for MALDI-TOF/MS Bruker including the 18 species, (b) to evaluate the suitability of the database for routine laboratory identification, and (c) to compare its performance with that of the currently available Bruker default database.

METHODS

A total of 205 isolates belonging to the 18 species identified by nrdA sequencing were used to build a local database. Main spectra profiles (MSPs) were created according to Bruker's recommendations for each isolate with the Biotyper software. Performance of the default Bruker database and ours for routine use were compared by testing 167 strains (including 38 isolates used from MSP creation) belonging to the 18 species identified by nrdA sequencing directly from colonies cultivated on various media.

RESULTS

Our new database accurately identified 99.4% (166/167) of the isolates from the 18 species (score ≥2.0) versus only 50.9% (85/167) with the Bruker database. In the Bruker database 17.3% of the isolates (29/167) were incorrectly identified as another species despite a score of ≥2.0.

CONCLUSIONS

The use of MALDI-TOF/MS in combination with a database developed with samples from 18 Achromobacter species provides rapid and accurate identification. This tool could be used to help future clinical studies.

First Documented Case of Percutaneous Endoscopic Gastrostomy (PEG) Tube-Associated Bacterial Peritonitis due to Achromobacter Species with Literature Review

Introduction. Achromobacter species (spp.) peritonitis has seldom been identified in medical literature. Scarce cases of Achromobacter peritonitis described previously have been correlated with peritoneal dialysis and more sparingly with spontaneous bacterial peritonitis. Achromobacter exhibits intrinsic and acquired resistance, especially in chronic infections, to most antibiotics. This article conducts a literature review of all previously reported Achromobacter spp. peritonitis and describes the first reported case of Achromobacter peritonitis as a complication of percutaneous endoscopic gastrostomy (PEG) tube placement. Discussion. Achromobacter peritonitis as a complication of PEG-tube placement has not been previously reported. In our patients' case, the recently placed PEG-tube with ascitic fluid leakage was identified as the most plausible infection source. Although a rare bacterial peritonitis pathogen, Achromobacter may be associated with wide antimicrobial resistance and unfavorable outcomes. Conclusion. No current guidelines provide significant guidance on treatment of PEG-tube peritonitis regardless of microbial etiology. Infectious Disease Society of America identifies various broad-spectrum antibiotics targeting nosocomial intra-abdominal coverage; some of these antimicrobial selections (such as cefepime and metronidazole combination) may yet be inadequate for widely resistant Achromobacter spp. Recognizably, the common antibiotics utilized for spontaneous bacterial peritonitis, i.e., third generation cephalosporins and fluoroquinolones, to which Achromobacter is resistant and variably susceptible, respectively, would be extensively insufficient. Piperacillin/tazobactam (P/T) and carbapenem were identified to provide the most reliable coverage in vitro; clinically, 5 out of the 8 patients who received either P/T or a carbapenem, or both, eventually experienced clinical improvement.

Study of 109 Achromobacter spp. isolates from 9 French CF centres reveals the circulation of a multiresistant clone of A. xylosoxidans belonging to ST 137

We previously reported the distribution of Achromobacter spp. (species and Sequence Types (ST)) in our French Cystic Fibrosis (CF) centre. In the present study we collected 109 Achromobacter isolates (1/patient) from 9 other French CF Centres for species identification, antimicrobial susceptibility testings and Multilocus-Sequence-Typing (MLST) analysis. Ten species were detected, A. xylosoxidans being the most predominant one (73.4% of the isolates). Piperacillin-tazobactam, ceftazidime, imipenem, meropenem and ciprofloxacin were respectively active against 88, 70, 79, 72 and 23% of the isolates. Among the 79 A. xylosoxidans isolates, 46 STs were detected. Interestingly, ST 137, recovered in 4 centres (5 patients), was previously detected in our centre (2 patients). The strains from the 7 patients belonged to the same pulsotype (pulsed-field-gel-electrophoresis analysis) and harboured acquired resistance to meropenem, ceftazidime, ciprofloxacin, and except for 2 isolates, to imipenem and piperacillin-tazobactam. This is the first description in France of a circulating multiresistant A. xylosoxidans strain.

Fluoroquinolone-resistant Achromobacter xylosoxidans clinical isolates from Serbia: high prevalence of the aac-(6')-Ib-cr gene among resistant isolates

The aim of this study was to evaluate the contribution of plasmid-mediated genes and efflux to fluoroquinolone resistance in collection of Achromobacter spp. gathered during a 3-year period. Susceptibility to ciprofloxacin and levofloxacin was tested by disk diffusion and microdilution tests for a collection of 98 Achromobacter spp. clinical isolates. Identification of fluoroquinolone-resistant isolates was performed by sequencing and phylogenetic analyses of the nrdA gene. Genetic relatedness among resistant isolates was determined by pulsed-field gel electrophoresis (PFGE) analysis. The influence of an H⁺ conductor cyanide m-chlorophenyl hydrazone (CCCP) and a resistance-nodulation-division-type efflux pump inhibitor phenylalanine-arginine beta-naphthylamide (PAβN) on minimal inhibitory concentration (MIC) value was evaluated by broth microdilution. The presence of the plasmid-mediated qnrA, qnrB, qnrC, qnrS, and aac-(6')-Ib-cr genes was investigated by PCR and sequencing. Achromobacter spp. isolates that were resistant or intermediately resistant to fluoroquinolones in disk diffusion tests (44/98) were subjected to microdilution. As a result, 20/98 isolates were confirmed to be resistant to ciprofloxacin while 10/98 was resistant to levofloxacin. CCCP decreased twofold MIC value for ciprofloxacin in six isolates and more than 16 times in one isolate, while MIC value for levofloxacin was decreased in all isolates (twofold to more than eightfold). Fluoroquinolone-resistant isolates were identified as A. xylosoxidans with the nrdA gene sequencing. PFGE revealed that resistant isolates belonged to seven different genotypes. Ten isolates belonging to four genotypes were positive for the aac-(6')-Ib-cr gene. Although resistance to fluoroquinolones was not widespread among analyzed isolates, detected contribution of efflux pumps and the presence of the aac-(6')-Ib-cr gene present a platform for emergence of more resistant strains.

Proteomic identification of Axc, a novel beta-lactamase with carbapenemase activity in a meropenem-resistant clinical isolate of Achromobacter xylosoxidans

The development of antibiotic resistance during treatment is a threat to patients and their environment. Insight in the mechanisms of resistance development is important for appropriate therapy and infection control. Here, we describe how through the application of mass spectrometry-based proteomics, a novel beta-lactamase Axc was identified as an indicator of acquired carbapenem resistance in a clinical isolate of Achromobacter xylosoxidans. Comparative proteomic analysis of consecutively collected susceptible and resistant isolates from the same patient revealed that high Axc protein levels were only observed in the resistant isolate. Heterologous expression of Axc in Escherichia coli significantly increased the resistance towards carbapenems. Importantly, direct Axc mediated hydrolysis of imipenem was demonstrated using pH shift assays and ¹H-NMR, confirming Axc as a legitimate carbapenemase. Whole genome sequencing revealed that the susceptible and resistant isolates were remarkably similar. Together these findings provide a molecular context for the fast development of meropenem resistance in A. xylosoxidans during treatment and demonstrate the use of mass spectrometric techniques in identifying novel resistance determinants.

Role of AxyZ Transcriptional Regulator in Overproduction of AxyXY-OprZ Multidrug Efflux System in Achromobacter Species Mutants Selected by Tobramycin

AxyXY-OprZ is an RND-type efflux system that confers innate aminoglycoside resistance to Achromobacter spp. We investigated here a putative TetR family transcriptional regulator encoded by the axyZ gene located upstream of axyXY-oprZ An in-frame axyZ gene deletion assay led to increased MICs of antibiotic substrates of the efflux system, including aminoglycosides, cefepime, fluoroquinolones, tetracyclines, and erythromycin, indicating that the product of axyZ negatively regulates expression of axyXY-oprZ Moreover, we identified an amino acid substitution at position 29 of AxyZ (V29G) in a clinical Achromobacter strain that occurred during the course of chronic respiratory tract colonization in a cystic fibrosis (CF) patient. This substitution, also detected in three other strains exposed in vitro to tobramycin, led to an increase in the axyY transcription level (5- to 17-fold) together with an increase in antibiotic resistance level. This overproduction of AxyXY-OprZ is the first description of antibiotic resistance acquisition due to modification of a chromosomally encoded mechanism in Achromobacter and might have an impact on the management of infected CF patients. Indeed, tobramycin is widely used for aerosol therapy within this population, and we have demonstrated that it easily selects mutants with increased MICs of not only aminoglycosides but also fluoroquinolones, cefepime, and tetracyclines.

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

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.

A Pan-Genomic Approach to Understand the Basis of Host Adaptation in Achromobacter

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.

Achromobacter xylosoxidans is the predominant Achromobacter species isolated from diverse non-respiratory samples

Achromobacter spp. are emerging opportunistic Gram-negative rods responsible for diverse nosocomial or community-acquired infections. We describe, for the first time, the distribution of Achromobacter spp., defined by nrdA gene sequencing, and their antimicrobial susceptibility in a variety of non-respiratory samples recovered from hospitalized patients from 2010 to 2015. Of the 63 isolates studied, A. xylosoxidans was the most prevalent (41 isolates), and with the exception of A. insuavis (four isolates), the remaining 10 species identified were represented by one or two isolates only. All isolates were uniformly susceptible to piperacillin and piperacillin-tazobactam and 97% to meropenem, but 76% showed resistance to ciprofloxacin. This study confirms the diversity of Achromobacter spp. in non-cystic fibrosis (CF) isolates and the predominance of A. xylosoxidans, as previously reported for CF sputum isolates. There was no apparent link between the clinical site of infection and the species of Achromobacter.