Achromobacter xylosoxidans septic arthritis in a patient with systemic lupus erythematosus

Recurrent Septic Arthritis Due to Achromobacter xylosoxidans in a Patient With Granulomatosis With Polyangiitis

We report a case of recurrent Achromobacter xylosoxidans infections including bacteremia, sepsis, septic joints and endocarditis in a 72 year old female with granulomatosis with polyangiitis. Achromobacter xylosoxidans is a gram negative bacteria increasingly identified in immunocompromised patients. Surgical and medical therapy may need to be combined.

Skin and soft tissue infection caused by Achromobacter xylosoxidans: report of 14 cases

BACKGROUND

Skin and soft tissue infections (SSTIs) caused by Achromobacter xylosoxidans are very infrequent. The aim of the present study was to investigate the clinical and microbiological characteristics of this infection.

METHODS

We carried out a retrospective review of 14 cases of SSTI due to A. xylosoxidans that occurred at the University Hospital of Guadalajara (Spain) from January 2007 to December 2012.

RESULTS

The infection was secondary to vascular diseases, trauma, and recent surgery in 12 patients (85.7%). The most frequent clinical presentation was infection of a vascular ulcer (5 cases). The infection was monomicrobial in 7 patients (50%) and 9 cases were community-acquired (64.2%). The clinical outcome of the patients was uniformly good after antibiotic treatment, except in 4 patients who suffered recurrence of the infection.

CONCLUSION

A. xylosoxidans should be considered a potential pathogen in patients with SSTIs, especially in patients with vascular diseases or after surgery or trauma. A history of contact with water should be investigated in all cases. Treatment can be difficult due to the high level of antibiotic resistance. Trimethoprim-sulfamethoxazole may be useful for treatment in outpatients with community-acquired infections.

Detection of DNA from a range of bacterial species in the knee joints of dogs with inflammatory knee arthritis and associated degenerative anterior cruciate ligament rupture

Mixtures of bacterial nucleic acids can often be detected in synovial joints affected with arthritis. We investigated the potential role of such mixtures of bacterial nucleic acids in the pathogenesis of arthritis in a naturally occurring canine model. Dogs with a common inflammatory knee arthritis in which associated pathological degenerative anterior cruciate ligament (ACL) rupture often develops were studied. Synovial biopsies were obtained from 43 dogs with the naturally occurring ACL rupture arthropathy, 12 dogs with normal knees and intact ACL, and 16 dogs with normal knees and experimentally induced ACL rupture. Using PCR, specimens were tested for Borrelia burgdorferi OspA and p66 gene sequences. Broad-ranging 16S rRNA primers were also used; 'panbacterial' PCR products were cloned and multiple clones were sequenced for bacterial identification. Synovium was also studied histologically. The presence of bacterial DNA within the synovium was significantly associated with the naturally occurring ACL rupture arthropathy (p<0.05); knee joints from 37% of these dogs were PCR-positive. Mixtures of bacterial DNA were common and often included environmental bacteria; predominant organisms included Borrelia burgdorferi and Stenotrophomonas maltophilia. DNA from environmental bacteria was only found in dogs with the naturally occurring ACL rupture arthopathy; joints from 33% of affected dogs contained such bacterial DNA. Synovial inflammation developed in dogs with both naturally occurring and experimentally induced ACL rupture, when compared with intact ACL controls (p<0.01). These results indicate that mixtures of DNA derived from environmental bacteria are commonly found in the knee joint of a naturally occurring canine arthropathy, often in association with a recognized joint pathogen. Our results also suggest that knee instability alone is not responsible for this finding and have led us to hypothesize that mixtures of bacterial DNA are an important causative factor in the pathogenesis of inflammatory arthritis in this canine model.

Infection of a total hip prosthesis in a dog caused by Achromobacter(Alcaligenes) xylosoxidans

A four-year-old male, neutered Labrador retriever was presented with progressive left hindlimb lameness 10 months following total hip replacement. Radiography revealed changes consistent with infection and culture of joint fluid from the left coxofemoral joint revealed Achromobacter (Alcaligenes) xylosoxidans. The prosthesis was removed. Culture of the acetabular cup confirmed Achromobacter xylosoxidans. Achromobacter xylosoxidans is an uncommon but serious cause of nosocomial epidemics in hospitals for human beings. To the authors' knowledge, this is the first report of total hip prosthetic infection with Achromobacter xylosoxidans. Little is reported about its pathogenicity in human beings and the authors failed to retrieve any reports of its clinical significance in animals.

Septic arthritis caused by a gram-negative bacterium representing a new species related to the Bordetella-Alcaligenes complex

A knee-joint exudate culture yielded on two occasions a gram-negative bacterium. Regular methods for speciation did not provide an identification. The infection was successfully treated with ciprofloxacin. The unknown isolate, CCUG 36768, was subjected to further investigation, including 16S rDNA sequencing, protein profiling, cellular fatty acid analysis, and various biochemical tests, in order to produce a species identification. The 1469 bp-long 16S rDNA sequence did not reveal identity with any known species sequence. CCUG 36768 clustered in a group of species, including Alcaligenes defragrans, Denitrobacter permanens, Taylorella equigenitalis, Alcaligenes faecalis, and four strains of Alcaligenes species without a specific species name. Bordetella species also showed a high degree of similarity with CCUG 36768. Protein profiling, cellular fatty acid analysis and computer-assisted analysis of biochemical profiles indicated similarity with Bordetella-Alcaligenes species, often close to B. holmesii and B. avium. API 20 NE indicated the profile of Moraxella species of poor identity. It is concluded that CCUG 36768 represents a new bacterial species of pathogenic potential in humans. It is related to the Bordetella-Alcaligenes group. Powerful new methods for speciation are available and it is recommended that unknown isolates from normally sterile sites be submitted for further analysis. Several isolates are required for the definition of new species.

Investigation of hospital-acquired infections due to Alcaligenes denitrificans subsp. xylosoxydans by DNA restriction fragment length polymorphism

We demonstrate that DNA restriction fragment length polymorphism determined by pulsed-field gel electrophoresis is very useful in the investigation of the epidemiology of hospital-acquired infections caused by Alcaligenes denitrificans subsp. xylosoxydans. This approach showed that hospital-acquired infections caused by this opportunistic pathogen over a 6-month period in 10 patients hospitalized in an intensive care unit and a surgical unit were not a true outbreak. In addition, this molecular typing method established that the respiratory therapy equipment was the source of the contamination of two patients.