Pseudomonas paucimobilis bacteremia

A Rare Case of Sphingomonas paucimobilis Meningitis in the Absence of Cerebrospinal Fluid Pleocytosis

Sphingomonas paucimobilis is a nonfermentative gram-negative bacillus of low pathogenicity. The organism has been involved in causing a wide range of infections in community and hospital settings. Only 3 cases of meningitis caused by this organism have been reported so far. We report a rare case of S paucimobilis meningitis who presented with atypical symptoms. A 50-year-old female presented with headache, dizziness, chills, shakiness, and neck pain along with nuchal rigidity. On physical examination, severe neck rigidity along with decreased range of motion was noticed. Her cerebrospinal fluid showed gram-negative rods, and she was started on meropenem. The cerebrospinal fluid grew S paucimobilis sensitive to meropenem. She subsequently showed significant improvement and was discharged home on intravenous meropenem for 21 days and showed complete recovering in 5 weeks.

A Lethal Case of Sphingomonas paucimobilis Bacteremia in an Immunocompromised Patient

Sphingomonas paucimobilis is a yellow-pigmented, glucose nonfermenting, aerobic, Gram negative bacillus of low pathogenicity. This organism was found in the implantation of indwelling catheters, sterile intravenous fluid, or contaminated hospital environment such as tap and distilled water, nebulizer, ventilator, and hemodialysis device. A 55-year-old female was hospitalized for diabetic foot ulcer in the presence of multiple comorbidities: diabetes mellitus, colonic tuberculosis, end-stage renal disease, and indwelling catheters for central venous catheter and hemodialysis. The patient passed away on the 44th day of admission due to septic shock. The organism found on blood culture on the 29th day of admission was multidrug resistant S. paucimobilis. Severe infection and septic shock due to S. paucimobilis have been reported particularly in immunocompromised patients, but there has been only one reported case of death in a premature neonate with septic shock. This is the first reported lethal case of S. paucimobilis bacteremia in an adult patient.

Sphingomonas paucimobilis bacteremia in an HIV and hepatitis C co-infected patient

INTRODUCTION

Prompt diagnosis and treatment of blood stream infections in an immunocompromised host can result in a decrease in mortality with appropriate antibiotic coverage. Signs, symptoms, physical examination, cultures and sensitivity findings must be evaluated and interpreted together to accurately diagnose and manage the problem.

CASE PRESENTATION

We present a case of Sphingomonas paucimobilis bacteremia in a patient with Human Immunodeficiency virus (HIV) and hepatitis C virus co-infection.

CONCLUSION

To our knowledge, this is the first reported case of this organism in a patient with HIV co-infected with chronic hepatitis C virus.

Autoimmune disease triggered by infection with alphaproteobacteria

Despite having long been postulated, compelling evidence for the theory that microbial triggers drive autoimmunity has only recently been reported. A specific association between Novosphingobium aromaticivorans, an ubiquitous alphaproteobacterium, and primary biliary cirrhosis (PBC) has been uncovered in patients with PBC. Notably, the association between Novosphingobium infection and PBC has been confirmed in a mouse model in which infection leads to the development of liver lesions resembling PBC concomitant with the production of anti-PDC-E2 antibodies that cross-react with conserved PDC-E2 epitopes shared by Novosphingobium. The discovery of infectious triggers of autoimmunity is likely to change our current concepts about the etiology of various autoimmune syndromes and may suggest new and simpler ways to diagnose and treat these debilitating diseases.

Interplay between carbohydrate and lipid in recognition of glycolipid antigens by natural killer T cells

Natural killer T (NKT) cells are a T cell subpopulation that were named originally based on coexpression of receptors found on natural killer (NK) cells, cells of the innate immune system, and by T lymphocytes. The maturation and activation of NKT cells requires presentation of glycolipid antigens by CD1d, a cell surface protein distantly related to the major histocompatibility complex (MHC)-encoded antigen presenting molecules. This specificity distinguishes NKT cells from most CD4(+) and CD8(+) T cells that recognize peptides presented by MHC class I and class II molecules. The rapid secretion of a large amount of both Th1 and Th2 cytokines by activated NKT cells endows them with the ability to play a vital role in the host immune defense against various microbial infections. In this review, we summarize progress on identifying the sources of microbe-derived glycolipid antigens recognized by NKT cells and the biochemical basis for their recognition.

Sphingomonas paucimobilis bacteremia in humans: 16 case reports and a literature review

BACKGROUND/PURPOSE

Sphingomonas paucimobilis is a glucose-nonfermenting Gram-negative bacillus that is widely distributed in both natural environment and hospitals. Various infections in humans have been reported, but most have been limited to sporadic case reports. The aim of this study was to describe the clinical characteristics and manifestations of S. paucimobilis bacteremia. We also reviewed the literature on S. paucimobilis bacteremia.

METHODS

Cases of S. paucimobilis bacteremia were identified retrospectively at a university-affiliated hospital in Taiwan. In addition, relevant case reports were identified through PubMed and reviewed.

RESULTS

From April 2004 to April 2008, 42 cases of S. paucimobilis bacteremia were identified in this study. Among them, 16 cases were identified from E-Da hospital, Kaohsiung, Taiwan and 26 cases from the literature review. The median age of patients was 48.5 years and 57.1% were male. The most common comorbidities included malignancy (57.1%), immunosuppressant use (40.5%), and diabetic mellitus (11.9%). Hospital-acquired bacteremia accounted for 69.0% of infections. Primary bacteremia and catheter-related bloodstream infection were found in 35.7% and 33.3% respectively. The most effective antibiotics were fluoroquinolones, carbapenems, and beta-lactam/beta-lactamase inhibitor combinations. All 42 patients survived the S. paucimobilis bacteremic episodes, but three patients experienced septic shock.

CONCLUSION

S. paucimobilis can cause infections in healthy as well as immunocompromised individuals. Although it is an organism of low clinical virulence, infection caused by S. paucimobilis can lead to septic shock. Further clinical research is required to characterize this infection.

Sphingomonas paucimobilis bacteraemia and septic arthritis in a diabetic patient presenting with septic pulmonary emboli

Sphingomonas paucimobilis, a yellow-pigmented, aerobic, glucose non-fermenting, Gram-negative bacillus, is a rare cause of human infection normally associated with immunocompromised hosts. We report a case of bacteraemia and septic arthritis in a 47-year-old diabetic man who presented with septic pulmonary emboli due to S. paucimobilis. The patient had an initial presentation of fever, right knee pain, coughing, dyspnoea and chest pain. The infection was treated successfully by surgical debridement combined with meropenem plus ciprofloxacin, based on the patient's antibiotic susceptibility profile. To our knowledge, this is the first case report for septic pulmonary emboli having arisen from an S. paucimobilis infection.

Assessment of inhibitory effects of fluoride-coated tubes on biofilm formation by using the in vitro dental unit waterline biofilm model

This study aimed to establish an in vitro model to simulate biofilms formed in dental unit waterlines (DUWLs) and to investigate the ability of polyvinylidene fluoride (PVDF)-coated tubes to inhibit biofilm formation using this model. The water and biofilm samples were obtained from DUWLs which had been clinically used for 2.5 years, and the predominant bacteria were identified. A conventional polyurethane tube was incubated for 24 to 96 h in the mixed flora of isolated bacteria, and the optimal incubation conditions to simulate a clinically formed biofilm were determined by observation with a scanning electron microscope. Biofilm formation on a PVDF-coated tube was observed using this in vitro model, and the adherence of different bacterial species to conventional and PVDF-coated tubes was assessed. Sphingomonas paucimobilis, Acinetobacter haemolytics, and Methylobacterium mesophilicum were predominantly isolated from contaminated DUWLs. Incubation of the polyurethane tube with the mixed flora containing these three species for 96 h resulted in the formation of a mature biofilm similar to the one clinically observed. The PVDF-coated tube was significantly less adhesive to all three bacterial species than the polyurethane tube (P < 0.05 by the Mann-Whitney U test), and the attachment of small amounts of rods was observed even after incubation with the mixed flora for 96 h. In conclusion, an in vitro biofilm model was obtained by using a mixed flora of bacteria isolated from DUWLs, and the PVDF-coated tube was found to be effective in preventing biofilm formation using this model.

Pseudomonas paucimobilis bacteraemia associated with haemodialysis

We report a case of Pseudomonas paucimobilis bacteraemia where the source was presumed to be related to haemodialysis. Previous reports have identified this organism as a pathogen in a variety of disease states including bacteraemia of unknown origin and in patients undergoing peritoneal dialysis.

Proposals of Sphingomonas paucimobilis gen. nov. and comb. nov., Sphingomonas parapaucimobilis sp. nov., Sphingomonas yanoikuyae sp. nov., Sphingomonas adhaesiva sp. nov., Sphingomonas capsulata comb. nov., and two genospecies of the genus Sphingomonas

Based on the partial nucleotide sequence analysis of 16S ribosomal ribonucleic acid (rRNA), presence of unique sphingoglycolipids in cellular lipid, and the major type of ubiquinone (Q10), we propose Sphingomonas gen. nov. with the type species Sphingomonas paucimobilis (Holmes et al, 1977) comb. nov. From the homology values of deoxyribonucleic acid-deoxyribonucleic acid hybridization and the phenotypic characteristics, three new species, Sphingomonas parapaucimobilis, Sphingomonas yanoikuyae, Sphingomonas adhaesiva, and one new combination, Sphingomonas capsulata, are described. S. parapaucimobilis JCM 7510 (= GIFU 11387), S. yanoikuyae JCM 7371 (= GIFU 9882), and S. adhaesiva JCM 7370 (= GIFU 11458) are designated as the type strains of the three new species. Emended description of the type strain of S. capsulata is presented.

Community-acquired bloodstream infection caused by Pseudomonas paucimobilis: case report and review of the literature

Various sources of Pseudomonas paucimobilis bacterial infections have been documented. We report the third human case of bloodstream infection due to P. paucimobilis and review the literature in English regarding community-acquired and nosocomial infection due to this bacterium. Biochemical and genetic characteristics supporting the pathogenic potential of P. paucimobilis are presented, and the antibiotic susceptibility profile of the organism is summarized.

An investigation of a collection of yellow-pigmented Pseudomonas

Thirty-six strains of yellow-pigmented Pseudomonas from clinical as well as non-clinical material and 11 reference strains of Pseudomonas were investigated by means of conventional bacteriological methods (a total of 53 different tests). Eighteen of the 36 yellow-pigmented strains could be classified as P. paucimobilis. Apart from the presence of lipid inclusions on beta-hydroxybutyrate, hydrolysis of DNA, and Tween 80 our results showed a high degree of accordance with other investigations. Eight strains showed characteristics compatible with inclusion in the CDC VE group; one orange-yellow strain showed the characteristics of P. vesicularis, and one was a pyoverdin negative, yellow P. putida. Eight strains remained unidentified. Strains of P. paucimobilis were most often resistant to antibiotics used for P. aeruginosa infections (viz. piperacillin, cefsulodin, ceftazidime) while the strains of the CDC VE group were often susceptible. Most strains were susceptible to the aminoglycosides. The difficulties in distinguishing yellow-pigmented strains of Pseudomonas from Flavobacterium spp. or Xanthomonas spp. are discussed.

Pseudomonas paucimobilis contamination of cool mist tents on a paediatric ward

Investigations resulting from the isolation of Pseudomonas paucimobilis from the atomizer units of paediatric cool mist tents implicated the hospital water supply as the potential source of contamination. The pathogenic potential of the organism and its role in nosocomial infection is discussed.

"Agrobacterium yellow group" and Pseudomonas paucimobilis causing peritonitis in patients receiving continuous ambulatory peritoneal dialysis

Five cases of peritonitis occurred during continuous ambulatory peritoneal dialysis in which unusual yellow pigmented Gram negative bacteria were isolated in pure culture. Four of these isolates were identified as the so called "Agrobacterium yellow group." The remaining isolate was identified as Pseudomonas paucimobilis, an organism closely related to the Agrobacterium yellow group.

Pseudomonas paucimobilis peritonitis in patients treated by peritoneal dialysis

Pseudomonas paucimobilis has rarely been reported as an opportunistic human pathogen. We report the isolation of this organism in two patients who developed peritonitis during the course of intermittent or continuous ambulatory peritoneal dialysis. The origin of the infection was related to contamination of the dialysate in the first patient but could not be determined in the second case.

Susceptibility of Pseudomonas paucimobilis to 24 antimicrobial agents

Pseudomonas paucimobilis (group IIK, biotype 1) clinical isolates showed in vitro resistance to ampicillin, carbenicillin, cephalothin, cefoxitin, cefamandole, moxalactam, cefotaxime, cefoperazone, mezlocillin, azlocillin, piperacillin, and ticarcillin. Those agents to which the microbes were shown to be susceptible were tetracycline, chloramphenicol, gentamicin, tobramycin, kanamycin, amikacin, netilmicin, sisomicin, trimethoprim-sulfamethoxazole, ceftazidime, ceftriaxone, and ceftizoxime.

Enzymatic profile of Pseudomonas paucimobilis

Pseudomonas paucimobilis, previously known as group IIK biotype 1, was found to have a significantly different enzyme profile from that of Flavobacterium multivorum, formerly group IIK biotype 2. P. paucimobilis produces several esterases and phosphatases which may contribute to its virulence.