Outbreak of Achromobacter xylosoxidans pseudobacteremia in a neonatal care unit related to contaminated chlorhexidine solution

Achromobacter cluster related to COVID-19 supply chain issues

Isolation of an unusual organism, Achromobacter xylosoxidans, from 2 cardiac surgical patients on the same day prompted an investigation to search for cases and cause. An extensive review demonstrated a pseudo-outbreak related to practices to conserve laboratory saline due to short supply resulting from supply chain shortage from the coronavirus disease 2019 pandemic.

Early Achromobacter xylosoxidans Endocarditis After the Valvular Mitral Replacement Complicated by an Agranulocytosis on B-lactams: A Case Report

An immunocompetent 82-year-old woman developed endocarditis caused by an atypical organism called Achromobacter xylosoxidans, after a first valvular surgery. The intravenous antibiotic therapy with ceftazidime - 2 g every 8 hours during five weeks - a key part of the treatment, induced agranulocytosis as an adverse event. Cross-reactivity between antibiotics was suspected. Finally, the patient's cure was the result of a coordinated effort between medical and surgical professionals. Postoperative follow-up is six years.

Clinicomicrobiological Profile of Infections by Achromobacter: An Emerging Nosocomial Pathogen in Indian Hospitals

Background

Achromobacter causes opportunistic nosocomial infections in immunocompromised patients with high mortality. It is underreported as it is often misidentified by conventional microbiological methods.

Aims

The aim of the study is to access the clinicomicrobiological profile and antibiogram of Achromobacter spp. from clinical isolates.

Materials and Methods

It is an observational study done from July 2020 to December 2021 in our hospital. All nonduplicate isolates of Achromobacter from blood and respiratory samples were initially identified with VITEK-2 GN card system and further confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antibiogram and treatment outcomes were also studied.

Results

Achromobacter spp. was isolated from 14 patients. Blood samples yielded most isolates (71.4%; n = 10) followed by tracheal aspirate and bronchoalveolar lavage fluid. Bacteremia followed by pneumonia was the most common clinical manifestation of Achromobacter infection. All the isolates were identified as A. xylosoxidans denitrificans and showed 100% susceptibility to minocycline and piperacillin-tazobactam. Diabetes mellitus and malignancy were the most common underlying condition in these patients. A favorable outcome was seen in 78.6% of the individuals with timely institution of antibiotics and proper diagnosis.

Conclusion

Infections due to Achromobacter are on the rise in developing countries like India. Resistance to many classes of antimicrobials makes its treatment more challenging therefore it should always be guided by antibiograms. The present study highlights the significance of this rare bacterium in patients with malignancies in India and advocates greater vigilance toward appropriate identification of this organism.

Outbreak and control of Achromobacter denitrificans at an academic hospital in Pretoria, South Africa

OBJECTIVE

In this study, we sought to determine the source of an outbreak of Achromobacter denitrificans infections in patients at a tertiary-care academic hospital.

DESIGN

Outbreak report study with intervention. The study period extended from February 2018 to December 2018.

SETTING

The study was conducted at a tertiary-care academic hospital in Pretoria, South Africa.

PATIENTS AND PARTICIPANTS

All patients who cultured A. denitrificans from any site were included in this study. During the study period, 43 patients met this criterion.

INTERVENTIONS

Once an outbreak was confirmed, the microbiology laboratory compiled a list of affected patients. A common agent, chlorhexidine-and-water solution, was used as a disinfectant-antiseptic for all affected patients. The laboratory proceeded to culture this solution. Environmental and surface swabs were also cultured from the hospital pharmacy area where this solution was prepared. Repetitive-element, sequence-based, polymerase chain reaction (rep-PCR) was performed on the initial clinical isolates to confirm the relatedness of the isolates.

RESULTS

In total, 43 isolates of A. denitrificans were cultured from patient specimens during the outbreak. The laboratory cultured A. denitrificans from all bottles of chlorhexidine-and-water solutions sampled from the wards and the pharmacy. The culture of the dispenser device used to prepare this solution also grew A. denitrificans. The rep-PCR confirmed the clonality of the clinical isolates with 2 genotypes dominating.

CONCLUSIONS

Contaminated chlorhexidine-and-water solutions prepared at the hospital pharmacy was determined to be the source of the outbreak. Once this item was removed from the hospital, the laboratory did not culture any further A. denitrificans isolates from patient specimens.

Recurrent environmental contamination in a centralized radiopharmacy unit by Achromobacter spp: results of a large microbiological investigation

BACKGROUND

Radiopharmaceuticals preparation unit, such as every aseptic preparation units, are strictly monitored in terms of microbiological contamination. Despite all biocontamination control procedures, our radiopharmacy unit faced repeated environnmental contamination by Achromobacter spp which necessitated a large environmental investigation.

METHOD

Microbiological controls were carried out using Count Tact agars (Biomérieux) for flat surfaces, dry swabbing for hard to reach areas and containers were filled with a sterile water solution (then filtrated on 0.45µm membrane and seeded). Microbiological identification was performed by mass spectrometry (MALDI-TOF-MS, Brucker) on each positive sample.

RESULTS

Achromobacter spp was found in 10% of the 413 samples during the 8 months investigation period. The proportion of positive samples was stable among time but their location was unpredictable. The highest inoculum was finally found in the buckets used for biocleaning.

DISCUSSION

Samples from cleaning buckets taken by dry swabbing were at first negative, but the use of a non-routinely used sampling method allowed to discover the reservoir of this persistent contamination.

CONCLUSION

This investigation alerted us on the high microbiological risk associated with reusable plastic containers and the importance of a sampling method adapted to critical locations.

Report of two events of nosocomial outbreak and pseudo-outbreak due to contamination with Achromobacter spp

Achromobacter spp. are increasingly recognized as emerging pathogens in immunocompromised patients or suffering cystic fibrosis, but unusual in immunocompetent hosts or individuals that underwent surgery. In this study we describe two simultaneous events attributable to two different Achromobacter spp. contaminated sources. One event was related to an episode of pseudo-bacteremia due to sodium citrate blood collection tubes contaminated with Achromobacter insuavis and the other to Achromobacter genogroup 20 infection and colonization caused by an intrinsically contaminated chlorhexidine soap solution. Both threatened the appropriate use of antimicrobials. Molecular approaches were critical to achieving the accurate species identification and to assess the clonal relationship, strengthening the need for dedicated, multidisciplinary and collaborative work of microbiologists, specialists in infectious diseases, epidemiologists and nurses in the control of infections to clarify these epidemiological situations.

A cluster of Achromobacter xylosoxidans led to identification of Pseudomonas aeruginosa and Serratia marcescens contamination at a long-term-care facility

A cluster of Achromobacter xylosoxidans, an emerging multidrug-resistant aquaphilic bacterium, was identified in 3 long-term-care facility residents. As Pseudomonas aeruginosa and Serratia marcescens were also present in clinical specimens, we conducted an investigation of all 3 water-associated species and identified P. aerguniosa and S. marcescens contamination at the facility. Sequencing analysis linked P. aeruginosa to a clinical isolate. Findings highlight the need for precautionary measures to prevent transmission of water-associated multidrug-resistant bacteria in long-term-care facilities.

Duplex real-time PCR assay for the simultaneous detection of Achromobacter xylosoxidans and Achromobacter spp

Several members of the Gram-negative environmental bacterial genus Achromobacter are associated with serious infections, with Achromobacter xylosoxidans being the most common. Despite their pathogenic potential, little is understood about these intrinsically drug-resistant bacteria and their role in disease, leading to suboptimal diagnosis and management. Here, we performed comparative genomics for 158 Achromobacter spp. genomes to robustly identify species boundaries, reassign several incorrectly speciated taxa and identify genetic sequences specific for the genus Achromobacter and for A. xylosoxidans. Next, we developed a Black Hole Quencher probe-based duplex real-time PCR assay, Ac-Ax, for the rapid and simultaneous detection of Achromobacter spp. and A. xylosoxidans from both purified colonies and polymicrobial clinical specimens. Ac-Ax was tested on 119 isolates identified as Achromobacter spp. using phenotypic or genotypic methods. In comparison to these routine diagnostic methods, the duplex assay showed superior identification of Achromobacter spp. and A. xylosoxidans, with five Achromobacter isolates failing to amplify with Ac-Ax confirmed to be different genera according to 16S rRNA gene sequencing. Ac-Ax quantified both Achromobacter spp. and A. xylosoxidans down to ~110 genome equivalents and detected down to ~12 and ~1 genome equivalent(s), respectively. Extensive in silico analysis, and laboratory testing of 34 non-Achromobacter isolates and 38 adult cystic fibrosis sputa, confirmed duplex assay specificity and sensitivity. We demonstrate that the Ac-Ax duplex assay provides a robust, sensitive and cost-effective method for the simultaneous detection of all Achromobacter spp. and A. xylosoxidans and will facilitate the rapid and accurate diagnosis of this important group of pathogens.

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.

Early-onset Sepsis Among Preterm Neonates in China, 2015 to 2018

BACKGROUND

The epidemiology of early-onset sepsis (EOS) in China is poorly understood because of the paucity of high-quality data. We aimed to examine the epidemiology, pathogen distribution and neonatal outcomes of EOS among a large cohort of preterm infants in China.

METHODS

All infants born at <34 weeks of gestation and admitted to 25 tertiary neonatal intensive care units in China from April 2015 to May 2018 were enrolled. EOS was defined as a culture-confirmed infection that occurred within 72 hours after birth.

RESULTS

Among 27,532 enrolled infants, 321 (11.7 cases per 1000 admissions) infants developed EOS, and 61 (19.0%) infants died within seven days after EOS onset. The incidence of EOS among inborn infants in 18 perinatal centers was 9.7 cases per 1000 live births <34 weeks' gestation (186/19,084). The case fatality rate was 22.6% (42/186). Gram-negative bacteria were responsible for 61.7% of EOS and 82.0% of EOS-related deaths. Escherichia coli (20.3%) was the leading pathogen, followed by Coagulase-negative staphylococcus (16.5%), Achromobacter xylosoxidans (9.0%) and Klebsiella pneumoniae (8.1%). Group B streptococci infections were relatively rare (2.5%). EOS was an independent risk factor for all-cause mortality and retinopathy of prematurity.

CONCLUSIONS

There is a high burden of EOS among preterm infants in China with a distinctive pathogen distribution. Longitudinal epidemiologic monitoring, further investigation of causative pathogens and development of targeted strategies for prevention and treatment of EOS are needed.

Outbreak of Achromobacter xylosoxidans and Ochrobactrum anthropi Infections after Prostate Biopsies, France, 2014

We report an outbreak of healthcare-associated prostatitis involving rare environmental pathogens in immunocompetent patients undergoing transrectal prostate biopsies at Hôpital Édouard Herriot (Lyon, France) during August 13-October 10, 2014. Despite a fluoroquinolone-based prophylaxis, 5 patients were infected with Achromobacter xylosoxidans and 3 with Ochrobactrum anthropi, which has not been reported as pathogenic in nonimmunocompromised persons. All patients recovered fully. Analysis of the outbreak included case investigation, case-control study, biopsy procedure review, microbiologic testing of environmental and clinical samples, and retrospective review of hospital records for 4 years before the outbreak. The cases resulted from asepsis errors during preparation of materials for the biopsies. A low-level outbreak involving environmental bacteria was likely present for years, masked by antimicrobial drug prophylaxis and a low number of cases. Healthcare personnel should promptly report unusual pathogens in immunocompetent patients to infection control units, and guidelines should explicitly mention asepsis during materials preparation.

First report of a cross-kingdom pathogenic bacterium, Achromobacter xylosoxidans isolated from stipe-rot Coprinus comatus

Coprinus comatus is an edible mushroom widely cultivated in China as a delicious food. Various diseases have occurred on C. comatus with the cultivated area increasing. In this study, the pathogenic bacterium JTG-B1, identified as Achromobacter xylosoxidans by 16S rDNA and nrdA gene sequencing, was isolated from edible mushroom Coprinus comatus with serious rot disease on its stipe. A. xylosoxidans has been confirmed as an important opportunistic human pathogenic bacterium and has been isolated from respiratory samples from cystic fibrosis. It is widely distributed in the environment. Here, we first report that fungi can also serve as a host for A. xylosoxidans. We confirmed that it can cross-kingdom infect between animals (mice) and fungi (C. comatus). The results of pathogenicity tests, physiological, biochemical and genotyping analysis of A. xylosoxidans from different hosts suggested that different strain of A. xylosoxidans may have pathogenicity differentiation. A. xylosoxidans not only is pathogenic to C. comatus but also may threaten human health.

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.

A Case of Septic Shock caused by Achromobacter xylosoxidans in an Immunocompetent Female Patient after Extracorporeal Shock Wave Lithotripsy for a Ureteral Stone

Achromobacter xylosoxidans can cause various types of infections, but its infection in humans is rare. A. xylosoxidans has been reported as a rare etiological agent of infections including primary bacteremia, catheter-related bloodstream infection, endocarditis, otitis, and pneumonia, particularly in immunocompromised hosts. We encountered a case of septic shock caused by A. xylosoxidans in a 52-year-old, immunocompetent woman with no underlying disease, who received extracorporeal shock wave lithotripsy to remove a left upper ureteral stone. She was treated with antibiotics to which the organism was susceptible but died as a result of septic shock.

Achromobacter respiratory infections

Achromobacteria are ubiquitous environmental organisms that may also become opportunistic pathogens in certain conditions, such as cystic fibrosis, hematologic and solid organ malignancies, renal failure, and certain immune deficiencies. Some members of this genus, such as xylosoxidans, cause primarily nosocomially acquired infections affecting multiple organ systems, including the respiratory tract, urinary tract, and, less commonly, the cardiovascular and central nervous systems. Despite an increasing number of published case reports and literature reviews suggesting a global increase in achromobacterial disease, most clinicians remain uncertain of the organism's significance when clinically isolated. Moreover, effective treatment can be challenging due to the organism's inherent and acquired multidrug resistance patterns. We reviewed all published cases to date of non-cystic fibrosis achromobacterial lung infections to better understand the organism's pathogenic potential and drug susceptibilities. We found that the majority of these cases were community acquired, typically presenting as pneumonias (88%), and were most frequent in individuals with hematologic and solid organ malignancies. Our findings also suggest that achromobacterial lung infections are difficult to treat, but respond well to extended-spectrum penicillins and cephalosporins, such as ticarcillin, piperacillin, and cefoperazone.

Pseudomonas aeruginosa and Achromobacter sp. clonal selection leads to successive waves of contamination of water in dental care units

Dental care unit waterlines (DCUWs) consist of complex networks of thin tubes that facilitate the formation of microbial biofilms. Due to the predilection toward a wet environment, strong adhesion, biofilm formation, and resistance to biocides, Pseudomonas aeruginosa, a major human opportunistic pathogen, is adapted to DCUW colonization. Other nonfermentative Gram-negative bacilli, such as members of the genus Achromobacter, are emerging pathogens found in water networks. We reported the 6.5-year dynamics of bacterial contamination of waterlines in a dental health care center with 61 dental care units (DCUs) connected to the same water supply system. The conditions allowed the selection and the emergence of clones of Achromobacter sp. and P. aeruginosa characterized by multilocus sequence typing, multiplex repetitive elements-based PCR, and restriction fragment length polymorphism in pulsed-field gel electrophoresis, biofilm formation, and antimicrobial susceptibility. One clone of P. aeruginosa and 2 clones of Achromobacter sp. colonized successively all of the DCUWs: the last colonization by P. aeruginosa ST309 led to the closing of the dental care center. Successive dominance of species and clones was linked to biocide treatments. Achromobacter strains were weak biofilm producers compared to P. aeruginosa ST309, but the coculture of P. aeruginosa and Achromobacter enhanced P. aeruginosa ST309 biofilm formation. Intraclonal genomic microevolution was observed in the isolates of P. aeruginosa ST309 collected chronologically and in Achromobacter sp. clone A. The contamination control was achieved by a complete reorganization of the dental health care center by removing the connecting tubes between DCUs.

Fatal non-thrombotic pulmonary embolization in a patient with undiagnosed factitious disorder

Background

Factitious fever is extremely challenging to diagnose in patients with complicated chronic medical problems, and represents as much as 10% of fevers of unknown origin. Factitious fever caused by self-injecting oral medications through indwelling central catheters is a diagnostic challenge.

Case presentation

We present a 32-year-old Caucasian female with history of short gut syndrome, malnutrition requiring total parental nutrition, and pancreatic auto-islet transplant with fever of unknown origin. Multiple episodes of bacteremia occurred with atypical pathogens, including α-hemolytic Streptococcus, Achromobacter xylosoxidans, and Mycobacterium mucogenicum. Chest computed tomography was notable for extensive tree-in-bud infiltrates. Sudden cardiac arrest with right-sided heart failure following acute hypoxemia led to her death. Diffuse microcrystalline cellulose emboli with foreign body granulomatosis was found on autopsy. Circumstantial evidence indicated that this patient suffered from factitious disorder, and was self-injecting oral medications through her central catheter.

Conclusion

A high index of suspicion, early recognition, and multifaceted team support is essential to detect and manage patients with factitious disorders before fatal events occur.

Detection of Achromobacter xylosoxidans in hospital, domestic, and outdoor environmental samples and comparison with human clinical isolates

Achromobacter xylosoxidans is an aerobic nonfermentative Gram-negative rod considered an important emerging pathogen among cystic fibrosis (CF) patients worldwide and among immunocompromised patients. This increased prevalence remains unexplained, and to date no environmental reservoir has been identified. The aim of this study was to identify potential reservoirs of A. xylosoxidans in hospital, domestic, and outdoor environments and to compare the isolates with clinical ones. From 2011 to 2012, 339 samples were collected in Dijon's university hospital, in healthy volunteers' homes in the Dijon area, and in the outdoor environment in Burgundy (soil, water, mud, and plants). We designed a protocol to detect A. xylosoxidans in environmental samples based on a selective medium: MCXVAA (MacConkey agar supplemented with xylose, vancomycin, aztreonam, and amphotericin B). Susceptibility testing, genotypic analysis by pulsed-field gel electrophoresis, and blaOXA-114 sequencing were performed on the isolates. A total of 50 strains of A. xylosoxidans were detected in hospital (33 isolates), domestic (9 isolates), and outdoor (8 isolates) samples, mainly in hand washing sinks, showers, and water. Most of them were resistant to ciprofloxacin (49 strains). Genotypic analysis and blaOXA-114 sequencing revealed a wide diversity among the isolates, with 35 pulsotypes and 18 variants of oxacillinases. Interestingly, 10 isolates from hospital environment were clonally related to clinical isolates previously recovered from hospitalized patients, and one domestic isolate was identical to one recovered from a CF patient. These results indicate that A. xylosoxidans is commonly distributed in various environments and therefore that CF patients or immunocompromised patients are surrounded by these reservoirs.

Bacteremia due to Achromobacter xylosoxidans in neonates: clinical features and outcome

Objective

We report an outbreak of Achromobacter xylosoxidans at a neonatal intensive care unit. We aimed to present clinical, laboratory and treatment data of the patients.

Materials and methods

All consecutive episodes of bacteremia due to A. xylosoxidans at our neonatal intensive care unit, beginning with the index case detected at November 2009 until cessation of the outbreak in April 2010, were evaluated retrospectively.

Results

Thirty-four episodes of bacteremia occurred in 22 neonates during a 6-month period. Among the affected, 90% were preterm newborns with gestational age of 32 weeks or less and 60% had birth weight of 1000 g or less. Endotracheal intubation, intravenous catheter use, total parenteral nutrition and prolonged antibiotic therapy were the predisposing conditions. Presenting features were abdominal distention, thrombocytopenia and neutropenia. The mortality rate was 13.6% and the majority of isolates were susceptible to piperacillin-tazobactam, carbapenems and trimethoprim-sulfametoxazole, and resistant to gentamycin. More than half were breakthrough infections. Despite intensive efforts to control the outbreak by standard methods of hand hygiene, patient screening and isolation, containment could be achieved only after the neonatal intensive care unit was relocated. The investigation was not able to single out the source of the outbreak.

Conclusion

A. xylosoxidans has the potential to cause serious infections in premature babies. More studies are needed to determine the importance of different sources of infection in hospital units.

Achromobacter species endocarditis: A case report and literature review

Endocarditis due to Achromobacter species is a rare, yet serious, endovascular infection. Achromobacter species infective endocarditis is associated with underlying immunodeficiencies or prosthetic heart valves and devices. A case of prosthetic pulmonary valve endocarditis secondary to Achromobacter xylosoxidans subspecies denitrificans is described in the present report. This life-threatening infection was successfully treated with combined valve replacement and prolonged antibiotic therapy. A Medline/PubMed literature review of Achromobacter endocarditis was also performed. Achromobacter species are an uncommon, yet important, cause of nosocomial endocarditis. Given the significant associated morbidity and mortality, along with a high degree of intrinsic antibiotic resistance, Achromobacter species infective endocarditis remains a clinical treatment challenge.

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.

Got black swimming dots in your cell culture? Identification of Achromobacter as a novel cell culture contaminant

Cell culture model systems are utilized for their ease of use, relative inexpensiveness, and potentially limitless sample size. Reliable results cannot be obtained, however, when cultures contain contamination. This report discusses the observation and identification of mobile black specks observed in multiple cell lines. Cultures of the contamination were grown, and DNA was purified from isolated colonies. The 16S rDNA gene was PCR amplified using primers that will amplify the gene from many genera, and then sequenced. Sequencing results matched the members of the genus Achromobacter, bacteria common in the environment. Achromobacter species have been shown to be resistant to multiple antibiotics. Attempts to decontaminate the eukaryotic cell culture used multiple antibiotics at different concentrations. The contaminating Achromobacter was eventually eliminated, without permanently harming the eukaryotic cells, using a combination of the antibiotics ciprofloxacin and piperacillin.

Hospital outbreak of Burkholderia stabilis bacteraemia related to contaminated chlorhexidine in haematological malignancy patients with indwelling catheters

Burkholderia cepacia complex (BCC) is an opportunistic pathogen that occasionally causes hospital outbreaks. This paper describes an outbreak of BCC bacteraemia in haematological malignancy patients related to a contaminated chlorhexidine gluconate solution. Eight BCC isolates were obtained from patients hospitalised in the same ward of a cancer centre in a Korean hospital. A further three BCC isolates were obtained from 0.5% chlorhexidine gluconate used in the same ward. The isolates were identified as B. stabilis and exhibited identical pulsed-field gel electrophoresis profiles. All patients with B. stabilis bacteraemia had indwelling intravenous catheters, which were treated with chlorhexidine to disinfect the catheters. Following identification of the source of contamination, strict controls regarding surveillance cultures for disinfectants have been enforced. No further B. stabilis infections have been found in the hospital.