Achromobacter xylosoxidans (Alcaligenes xylosoxidans subsp. xylosoxidans) meningitis associated with a gunshot wound

One year experience of Achromobacter bacteremia at a tertiary care hospital in Northern India

Introduction

Achromobacter is a Gram-negative, motile, obligate aerobic and non-fermentative bacterium. It is an emerging pathogen in the hospital environment as it is frequently found in various solutions.

Hypothesis/Gap Statement

Information about the incidence and risk factors of Achromobacter bacteremia from India is limited.

Aim

We conducted this study to identify the risk factors and underlying conditions predisposing to bacteremia by Achromobacter spp. and analyse the antibiotic resistance pattern of the isolates.

Methodology

We performed a retrospective observational study where automated blood cultures positive for Achromobacter spp. were assessed for clinical characteristics and antibiotic susceptibility patterns from January 2022 to December 2022 in the microbiology laboratory of a tertiary care centre in Northern India.

Results

A total of 14 cases (14/2435, 0.57 %) of Achromobacter spp. were identified from bloodstream infections in one year. The mean age of the patients was 37.59±23.17 years with a male predominance (8/14, 57.1 %). All patients were managed on intravenous antibiotics and intravenous access as peripheral line catheters and only 5(5/14, 35.7 %) patients were managed on central line catheters. The isolates were found highly susceptible to ticarcillin-clavulanic acid (14/14, 100.0 %) followed by fluoroquinolones (12/14, 85.72 %) and trimethoprim-sulphamethoxazole (12/14, 85.72 %). Only 57.14 % (8/14, 57.14 %) of the patients were susceptible to piperacillin-tazobactam. The all-cause 40 day mortality was observed in 35.7 % (5/14, 35.7 %) with two deaths that were directly attributable to sepsis.

Conclusion

This study provides insight into the incidence of Achromobacter bacteremia at our centre and the necessary antibiotic therapy to combat it.

Achromobacter spp. Surgical Site Infections: A Systematic Review of Case Reports and Case Series

Achromobacter species are isolated from rare but severe healthcare-associated infections, including surgical site infections. They are considered to preferentially infect immunocompromised patients but so far with limited evidence. We conducted a systematic review on Achromobacter spp. surgical site infections (SSIs) to determine if such infections were indeed more commonly associated with immunocompromised patients. The secondary objective was to describe the characteristics of infected patients. Eligible articles had to be published before 30 September 2020 and to report Achromobacter spp. SSIs across all surgical specialties excluding ophthalmology. Analyses were performed on individual data without meta-analysis. Cases were divided into 2 subgroups: one group which had either prosthesis or implant and the other group which did not. A first selection led to a review of 94 articles, of which 37 were analyzed. All were case reports or case series and corresponded to 49 infected patients. Most of the patients were under 65 years of age and had undergone a heart or digestive surgery followed by deep infection with no co-infecting pathogens. Nine out of the 49 cases were immunocompromised, with similar distribution between the two subgroups (16.6% and 20%, respectively). This review suggests that Achromobacter spp. SSIs do not preferentially target immunocompromised patients.

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.

Chronic Conjunctivitis From a Retained Contact Lens

PURPOSE

To help clinicians diagnose and manage unilateral recalcitrant chronic bacterial conjunctivitis secondary to a retained soft contact lens and describe the first report of Gram-negative bacteria causing this condition.

METHODS

Chart review of successive cases presenting with unilateral chronic conjunctivitis with positive cultures and a retained contact lens.

RESULTS

Three cases were identified and described. Culturing of the retained contact lenses grew Pseudomonas aeruginosa in the first case, Achromobacter xylosoxidans in the second, and Staphylococcus epidermidis in the third. All three patients were successfully treated with removal of the retained lens and targeted antibiotic eyedrop therapy.

CONCLUSIONS

Unilateral chronic recurrent or recalcitrant purulent papillary conjunctivitis is rare, and a retained contact lens should be suspected in patients with a history of wearing contact lenses. Careful examination with double eversion of the upper eyelid and sweeping of the fornices can recover the offending lens. Although only Gram-positive organisms have been isolated in previous reports, two of our three cultures grew Gram-negative organisms, highlighting the importance of broad-spectrum antibiotic usage for these cases.

Polymicrobial Intracerebral Abscess Growing Mycobacterium avium Complex and Achromobacter xylosoxidans: Case Report and Literature Review

BACKGROUND

Mycobacterium avium complex (MAC) and Achromobacter xylosoxidans (AX) are uncommon sources of neurosurgical infections, particularly in immunocompetent hosts. We report the first published case of intracranial AX abscess and polymicrobial AX-MAC abscess, as well as the fourth MAC abscess in a non-immunocompromised patient.

METHODS

This case report was conducted via retrospective chart review. A literature review was completed in compliance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

RESULTS

Ten years following mucocele resection, a 60-year-old man presented with sinus congestion and headache. Head imaging revealed a left frontal lesion abutting the cribriform plate and ethmoid roof. The patient had a left frontal craniotomy for abscess drainage. Intraoperative cultures demonstrated polymicrobial growth of AX and MAC, managed with antimicrobial therapy and staged skull base reconstruction. Three cases of MAC abscess and 16 cases of AX ventriculitis or meningitis have been reported in immunocompetent patients. All MAC cerebral abscesses occurred in adults, one of whom succumbed to the infection. Of the 9 AX meningitis cases, 4 occurred in neonates and 2 in pediatric patients. Six of the 7 AX ventriculitis cases occurred after neurosurgical operations at the same hospital from contaminated chlorhexidine basins. Except for the neonates, AX ventriculitis or meningitis patients had undergone neurosurgery or had a history of cranial trauma. There were no reports of polymicrobial AX-MAC intracranial abscess.

CONCLUSIONS

AX and MAC are rare causes of intracranial infection. Patients with these pathogens identified in the central nervous system require a multidisciplinary approach for successful management.

Contamination of burn wounds by Achromobacter Xylosoxidans followed by severe infection: 10-year analysis of a burn unit population

Gram-negative infections predominate in burn surgery. Until recently, Achromobacter species were described as sepsis-causing bacteria in immunocompromised patients only. Severe infections associated with Achromobacter species in burn patients have been rarely reported. We retrospectively analyzed all burn patients in our database, who were treated at the Intensive Care Burn Unit (ICBU) of the Cologne Merheim Burn Centre from January 2006 to December 2015, focusing on contamination and infection by Achromobacter species.We identified 20 patients with burns contaminated by Achromobacter species within the 10-year study period. Four of these patients showed signs of infection concomitant with detection of Achromobacter species. Despite receiving complex antibiotic therapy based on antibiogram and resistogram typing, 3 of these patients, who had extensive burns, developed severe sepsis. Two patients ultimately died of multiple organ failure. In 1 case, Achromobacter xylosoxidans was the only isolate detected from the swabs and blood samples taken during the last stage of sepsis. Achromobacter xylosoxidans contamination of wounds of severely burned immunocompromised patients can lead to systemic lethal infection. Close monitoring of burn wounds for contamination by Achromobacter xylosoxidans is essential, and appropriate therapy must be administered as soon as possible.

Genotypic and phenotypic applications for the differentiation and species-level identification of achromobacter for clinical diagnoses

The Achromobacter is a genus in the family Alcaligenaceae, comprising fifteen species isolated from different sources, including clinical samples. The ability to detect and correctly identify Achromobacter species, particularly A. xylosoxidans, and differentiate them from other phenotypically similar and genotypically related Gram-negative, aerobic, non-fermenting species is important for patients with cystic fibrosis (CF), as well as for nosocomial and other opportunistic infections. Traditional phenotypic profile-based analyses have been demonstrated to be inadequate for reliable identifications of isolates of Achromobacter species and genotypic-based assays, relying upon comparative 16S rRNA gene sequence analyses are not able to insure definitive identifications of Achromobacter species, due to the inherently conserved nature of the gene. The uses of alternative methodologies to enable high-resolution differentiation between the species in the genus are needed. A comparative multi-locus sequence analysis (MLSA) of four selected ‘house-keeping’ genes (atpD, gyrB, recA, and rpoB) assessed the individual gene sequences for their potential in developing a reliable, rapid and cost-effective diagnostic protocol for Achromobacter species identifications. The analysis of the type strains of the species of the genus and 46 strains of Achromobacter species showed congruence between the cluster analyses derived from the individual genes. The MLSA gene sequences exhibited different levels of resolution in delineating the validly published Achromobacter species and elucidated strains that represent new genotypes and probable new species of the genus. Our results also suggested that the recently described A. spritinus is a later heterotypic synonym of A. marplatensis. Strains were analyzed, using whole-cell Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight mass spectrometry (MALDI-TOF MS), as an alternative phenotypic profile-based method with the potential to support the identifications determined by the genotypic DNA sequence-based MLSA. The MALDI-TOF MS data showed good accordance in strain groupings and identifications by the MLSA data.

Resolution of concomitant Achromobacter xylosoxidans burn wound infection without adjustment of antimicrobial therapy

Achromobacter xylosoxidans is part of an emerging group of Gram negative bacterial infections with potentially severe sequelae, especially in the immunocompromised population such as burn patients. While antimicrobial therapy for patients with A. xylosoxidans bacteremia has been reported, the literature is scarce with regard to treatment in patients with positive tissue cultures only. Herein, we report our institution's experience with such a case and a brief review of the current literature on this micro-organism in the setting of non-bacteremic infection.

Achromobacter xylosoxidans mesh related infection: a case of delayed diagnosis and management

We present the first case of mesh related infection caused by Achromobacter xylosoxidans after ventral hernia repair. After repair of a small paraumbilical hernia, the postoperative course was complicated by persistent discharging sinuses despite the removal of underlying polypropylene mesh. Removal of an intrabdominal omental inflammatory mass containing pus that showed growth of A. xylosoxidans led to the resolution of all the symptoms.

Achromobacter xylosoxidans infection presenting as a pulmonary nodule mimicking cancer

Achromobacter xylosoxidans is typically isolated from pulmonary sources, presenting as pneumonia in immunosuppressed individuals. We describe a novel clinical presentation of A. xylosoxidans infection presenting as multiple spiculated, pulmonary nodules mimicking cancer for which the patient underwent a wedge resection of the lung for diagnosis and staging of presumptive cancer.

Clinical, microbiological profile and treatment outcome of ocular infections caused by Achromobacter xylosoxidans

PURPOSE

To study the microbiological profile and outcome of ocular infections caused by Achromobacter xylosoxidans.

METHODS

Medical and microbiology records of patients with A. xylosoxidans ocular infections managed between May 2007 and December 2007 were reviewed.

RESULTS

The authors identified 10 patients whose eyes were infected by A. xylosoxidans during the study period. Of 10 patients, 8 had microbial keratitis, of whom 6 developed an infection after penetrating keratoplasty. The remaining 2 patients had endophthalmitis. The Gram-stained smear did not reveal any organism in 6 of 10 cases. In the 4 remaining cases, Gram-negative bacilli were reported. Out of 10 isolates, 9 were sensitive to ceftazidime, 7 to amikacin, 5 to ciprofloxacin, and 3 to ofloxacin, gatifloxacin, and chloramphenicol. Only one isolate was sensitive to moxifloxacin. Of the 6 patients with graft infection, 2 patients were lost to follow-up, infection was resolved in 3 patients, and the infection remained active in 1 patient. The two patients with endophthalmitis responded to antibacterial therapy and showed improved visual acuity. Infection was resolved in 2 patients with keratitis.

CONCLUSION

Although A. xylosoxidans ocular infections are rare, one should retain a high index of clinical suspicion in patients who present with slowly progressive disease characterized by a localized infiltration and show Gram-negative bacilli on smear examination.

Ribosomal DNA-directed PCR for identification of Achromobacter (Alcaligenes) xylosoxidans recovered from sputum samples from cystic fibrosis patients

The opportunistic human pathogen Achromobacter (Alcaligenes) xylosoxidans has been recovered with increasing frequency from respiratory tract culture of persons with cystic fibrosis (CF). However, confusion of this species with other closely related respiratory pathogens has limited studies to better elucidate its epidemiology, natural history, and pathogenic role in CF. Misidentification of A. xylosoxidans as Burkholderia cepacia complex is especially problematic and presents a challenge to effective infection control in CF. To address the problem of accurate identification of A. xylosoxidans, we developed a PCR assay based on a 16S ribosomal DNA sequence. In an analysis of 149 isolates that included 47 A. xylosoxidans and several related glucose-nonfermenting species recovered from CF sputum, the sensitivity and specificity of this PCR assay were determined to be 100 and 97%, respectively. The availability of this assay will enhance identification of A. xylosoxidans, thereby facilitating study of the pathogenic role of this species and improving infection control efforts in CF.

Epidemiological typing of Alcaligenes xylosoxidans subsp. xylosoxidans by antibacterial susceptibility testing, fatty acid analysis, PAGE of whole-cell protein and pulsed-field gel electrophoresis

Antibacterial susceptibility testing, fatty acid analysis, protein analysis and DNA analysis of Alcaligenes xylosoxidans subsp. xylosoxidans were compared to determine the efficiency of the methods available for strain typing. Thirty isolates were investigated: 20 clinical isolates from a nonsocomial outbreak in Essen (Germany), 9 clinical isolates from sporadic nosocomial cases in Paris (France) and reference strain ATCC 2402. The highest microbiological discriminative power was exhibited by pulsed-field gel electrophoresis (PFGE) yielding nine types, followed by fatty acid methyl ester (FAME) analysis with six types, and antibacterial susceptibility testing and polyacrylamide gel electrophoresis with five types each. By combining the results of the four typing methods, 14 varieties could be differentiated. Protein analysis and fatty acid analysis failed to discriminate between isolates from Essen and Paris and the reference strain, while antibacterial susceptibility testing and DNA analysis clearly discriminated them. It is concluded that a combination of antibacterial susceptibility testing and PFGE typing is most suitable for epidemiological typing of Alcaligenes xylosoxidans subsp. xylosoxidans strains.

Comparison of polymerase chain reaction and pulsed-field gel electrophoresis for the epidemiological typing of Alcaligenes xylosoxidans subsp. xylosoxidans in a burn unit

Eighteen isolates of Alcaligenes xylosoxidans subsp. xylosoxidans were collected from clinical specimens of 15 patients in a burn unit and a plastic surgery ward over a 16-month period. Pulsed-field gel electrophoresis and polymerase chain reaction (PCR) were compared for the epidemiologic typing of these 18 isolates and fifteen epidemiologically unrelated strains. These 18 isolates demonstrated an identical fingerprint pattern and were easily distinguished from the 15 epidemiologically unrelated strains by pulsed-field gel electrophoresis typing and both enterobacterial repetitive intergenic concensus and repetitive extragenic palindrome-primed PCR fingerprinting. We conclude that pulsed-field gel electrophoresis analysis of XbaI-digested genomic DNA is a highly discriminatory and reproducible method for epidemiological typing of A. xylosoxidans subsp. xylosoxidans isolates. However, poor resolution due to frequent cutting in the smaller fragments (< 145.5 Kb) may lead to difficulty in interpretation. PCR is a rapid and highly discriminatory, but less reproducible, technique with occasional loss of major bands. The fingerprints produced by repetitive extragenic palindrome primed PCR had more intense bands and were easier to read than those produced by enterobacterial repetitive intergenic concensus-primed PCR in this study.