Chryseobacterium indologenes non-catheter-related bacteremia in a patient with a solid tumor

A case of hospital-acquired pneumonia associated with Chryseobacterium indologenes infection in a patient with HIV infection and review of the literature

BACKGROUND

Chryseobacterium indologenes is an opportunistic, multidrug-resistant Gram-negative bacillus increasingly recognized as a cause of hospital-acquired infections, particularly in immunocompromised patients. Although rare, its intrinsic resistance to beta-lactams and its ability to colonize medical devices pose significant therapeutic challenges.

CASE PRESENTATION

We describe a case of C. indologenes hospital-acquired pneumonia in a 43-year-old HIV-positive patient with multiple comorbidities, including Kaposi sarcoma, diabetes mellitus, and chronic kidney disease requiring hemodialysis. The patient was initially admitted with fever and elevated inflammatory markers, and empirical broad-spectrum antibiotic therapy was initiated. Despite initial improvement, the patient developed respiratory failure, requiring oxygen therapy. A respiratory panel identified Rhinovirus, while sputum culture revealed C. indologenes, resistant to multiple antibiotics but susceptible to levofloxacin. Targeted therapy led to clinical improvement. However, the course was complicated by Clostridioides difficile-associated diarrhea, followed by fatal sepsis due to Klebsiella pneumoniae. Our review of the literature identified 71 reported cases, with bacteremia (51%) and pneumonia (29%) as the most common clinical presentations. Medical devices and prolonged antibiotic exposure were key risk factors. While C. indologenes is intrinsically resistant to beta-lactams and carbapenems, fluoroquinolones and trimethoprim-sulfamethoxazole demonstrated efficacy in most cases. Emerging therapies, such as cefiderocol, may provide additional options for multidrug-resistant strains. This case highlights the critical need for accurate microbial identification, targeted therapy, and vigilant antimicrobial stewardship to improve outcomes in vulnerable patient populations.

CONCLUSION

C. indologenes infections remain rare but clinically significant in hospitalized patients with immune dysfunction. The pathogen's multidrug resistance profile complicates treatment, necessitating early identification and targeted antimicrobial therapy. Fluoroquinolones, trimethoprim-sulfamethoxazole, and cefiderocol may serve as effective treatment options, emphasizing the importance of susceptibility-guided management.

A rare urinary tract infection of multidrug-resistant Chryseobacterium urinae sp. nov. isolated from a diabetic, non-catheterized patient

Chryseobacterium demonstrates a diverse environmental presence and a significant pathogenic potential across various ecosystems. This clinical case showcases a rare instance of bacterial infection in a 75-year-old male with untreated diabetes and recurrent urinary tract infections (UTIs). The patient presented symptoms of abdominal pain, burning urination, fever, and an elevated eosinophil count. A subsequent urine culture identified a Chryseobacterium-related bacterium as the causative agent, exhibiting sensitivity to piperacillin/tazobactam, trimethoprim/sulfamethoxazole, and nitrofurantoin, which led to successful treatment using oral nitrofurantoin. Analysis of the 16S rRNA gene sequence of APV-1T revealed a close relationship of 98.2% similarity to Chryseobacterium gambrini strain 5-1St1aT (AM232810). Furthermore, comparative genome analysis, incorporating Average Nucleotide Identity (ANI), Digital DNA-DNA Hybridization (dDDH) values, and comprehensive phylogenetic assessments utilizing 16S rRNA gene sequences, core genes, and amino acid sequences of core proteins, highlighted the unique phylogenetic positioning of APV-1T within the Chryseobacterium genus. Distinct carbon utilization and assimilation patterns, along with major fatty acid content, set APV-1T apart from C. gambrini strain 5-1St1aT. These findings, encompassing phenotypic, genotypic, and chemotaxonomic characteristics, strongly support the proposal of a novel species named Chryseobacterium urinae sp. nov., with APV-1T designated as the type strain (= MCC 50690 = JCM 36476). Despite its successful treatment, the strain displayed resistance to multiple antibiotics. Genomic analysis further unveiled core-conserved genes, strain-specific clusters, and genes associated with antibiotic resistance and virulence. This report underscores the vital importance of elucidating susceptibility patterns of rare pathogens like Chryseobacterium, particularly in immunocompromised individuals. It advocates for further analyses to understand the functional significance of identified genes and their implications in treatment and pathogenesis.

Clinical and Microbiological Characteristics of Chryseobacterium indologenes Bacteremia: A 20-Year Experience in a Single University Hospital

BACKGROUND

Chryseobacterium indologenes is ubiquitous in nature and rarely causes infections. However, the clinical impact of C. indologenes has increased in recent years, especially in immunocompromised patients, and has resulted in high mortality rates. We aimed to investigate the clinical and microbiological characteristics of C. indologenes bacteremia.

MATERIALS AND METHODS

We retrospectively reviewed medical records of a 642-bed university-affiliated hospital in Korea, dating from January 2001 to December 2020, to investigate C. indologenes bacteremia.

RESULTS

A total of 22 C. indologenes isolates were identified from blood culture records. All patients were hospitalized at the time of bacteremia, and the most common manifestation was primary bacteremia. A sizable majority of the patients (83.3%) had underlying diseases, and all patients received intensive care unit care during their admission. The 14-day and 28-day mortality rates were 8.3% and 16.7%, respectively. Importantly, all C. indologenes isolates were 100% susceptible to trimethoprim-sulfamethoxazole.

CONCLUSION

In our study, most of the infections were hospital-acquired, and the susceptibility pattern of the C. indologenes isolates showed multidrug resistance. However, trimethoprim-sulfamethoxazole is a potentially useful antibiotic for C. indologenes bacteremia treatment. More attention is required to identify C. indologenes as one of the most important nosocomial bacteria with detrimental effects in immunocompromised patients.

Phenotypical Detection of β-Lactamases in a Multidrug-Resistant and Extensively Drug-Resistant Chryseobacterium indologens: A Rare Human Pathogen With Special References to Risk Factor

Chryseobacterium indologenes is gram-negative bacteria that cause infection in humans. It is less frequently isolated in the laboratory. The development of drug-resistant and its intrinsic ability to resist a wide range of antimicrobials enables them to cause mortality in an immunocompromised patient with a longer hospital stay. Our study objectives are to investigate antimicrobial-resistant patterns, drug-resistant enzymes, and the risk factor analysis associated with multidrug-resistant (MDR), extensively drug-resistant (XDR), and Pan-drug resistant (PDR) within 2 years. Altogether 53 strains of Chryseobacterium indologens were obtained from 5000 specimens that were processed for routine bacterial culture. The bacterial identification was done using conventional techniques (colony morphology, gram staining, flexirubin test, and biochemical tests) as well as the VITEK-2 System to further confirm. The bacterial isolate were processed to observe antimicrobial susceptibility test (AST) using disk diffusion method. MDR XDR and PDR were classified following European Centre for Disease Prevention and Control guidelines. C. indologens strains with beta-lactamases such as extended-spectrum beta-lactamases (ESBL), metallo beta-lactamases (MBL), and Amp-C beta-lactamases (Amp-C) were detected phenotypically. The highest isolation of C. indologens was observed in a sputum sample. In vitro antimicrobial susceptibility test revealed susceptibility to tigecycline followed by levofloxacin, cotrimoxazole, and piperacillin-tazobactam. From 53 isolates of C. indologens, MDR accounts for 56.60% and 22.64% for XDR. Combined antimicrobial therapy and longer hospital stay were found to be the leading risk factor. All 53 C. indologenes strains were detected as MBL. Total ESBL was detected in 16.98% of MBL producer strains and Amp-C was observed in 13.20% of MBL-producing strains. All 3 enzyme co-oproducers were seen in only 5.66% of C. indologens. Although it is rarely encountered in the laboratory, it showed a remarkable effect in patients with underlying predisposing factors and prolonged hospital stays. The presence of betalactamases determined the drug-resistant activity on a wide spectrum of tested antibiotics.

Qualification of Human Liver Microsomes for Antibacterial Activity Screening of Drug Metabolites

Microsomes are commonly used to perform in vitro drug metabolism, predominantly to form phase I drug metabolites. Pooled microsomes from multiple donors can contain microorganisms from underlying microbial diseases. Exposure to microbes can also occur during extraction if aseptic processing is compromised. Although microbial presence does not affect the metabolic activity of microsomes, presence of unwanted microorganisms can cause interference if the downstream application of microsomal drug metabolites is screening for antibacterial activity. In this work, traditional biochemical tests and advanced proteomics-based identification techniques were used to identify two gram-negative bacteria in pooled human liver microsomes. Several decontamination procedures were assessed to eradicate these two bacteria from the microsomes without affecting its metabolic capacity, and organic extraction was found to be the most convenient and efficient approach to decontaminate microsomes and screen drug metabolites for antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA).

Emerging Bacterial Pathogens in the COVID-19 Era: Chryseobacterium gleum—A Case in Point

Introduction In the ongoing severe acute respiratory syndrome coronavirus 2 pandemic, a long hospital stay and empirical broad-spectrum antibiotics make the patients prone to acquire nosocomial infections especially with unconventional organisms, and Chryseobacterium gleum is one such rare nosocomial pathogen.

Methods The given study is a case-series-based study conducted from September 2020 to April 2021 in which clinically suspected pneumonia patients who recovered from coronavirus disease 2019 (COVID-19) were included.

Results Seventeen C. gleum isolates were obtained in pure culture from the tracheal aspirates of nine COVID-19 patients (including repeat samples to rule out colonization) within a period of eight months (September 2020–April 2021). Our records showed that there has been an increase in the number of isolates of C. gleum obtained in respiratory samples in 2020. We also did a review of literature of all the cases of C. gleum pneumonia reported till now.

Conclusion To the best of our knowledge, this is the first study reporting the isolation of this rare pathogen from COVID-19 patients with clinical significance in a large cohort of patients. Therefore, it becomes important to consider this pathogen as a significant cause of respiratory infections, especially in patients recovered post COVID-19.

Characterization and Comparative Genomic Analysis of a Highly Colistin-Resistant Chryseobacterium gallinarum: a Rare, Uncommon Pathogen

For the first time, we describe the whole genome of a yellow-pigmented, capsule-producing, pathogenic, and colistin-resistant Chryseobacterium gallinarum strain MGC42 isolated from a patient with urinary tract infection in India. VITEK 2 automated system initially identified this isolate as C. indologenes. However, 16S rRNA gene sequencing revealed that MGC42 shared 99.67% sequence identity with C. gallinarum–type strain DSM 27622. The draft genome of the strain MGC42 was 4,455,926 bp long with 37.08% Guanine-Cytosine (GC) content and was devoid of any plasmid. Antibiotic resistance, virulence, and toxin genes were predicted by implementing a machine learning classifier. Potential homologs of 340 virulence genes including hemolysin secretion protein D, metalloprotease, catalase peroxidases and autotransporter adhesins, type VI secretion system (T6SS) spike proteins, and 27 toxin factors including a novel toxin domain Ntox23 were identified in the genome. Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologs of 110 transporter proteins were predicted that were in agreement with moderate efflux activity. Twelve antibiotic resistance genes including two potentially novel putative β-lactamase genes sharing low similarity with known β-lactamase genes were also identified in the genome of this strain. The strain MGC42 was also resistant to several classes of antibiotics along with carbapenems and polymyxin. We also identified mutations in the orthologs of pmrB (M384T) and lpxD (I66V) that might be responsible for colistin resistance. The MGC42 strain shared 683 core genes with other environmental and clinical strains of Chryseobacterium species. Our findings suggest that the strain MGC42 is a multidrug-resistant, virulent pathogen and recommend 16S rRNA gene sequencing to identify clinical specimens of Chryseobacterium species.

Chryseobacterium indologenes Keratitis: Successful Treatment of Multidrug-Resistant Strain

A 72-year-old male with history of monocular vision with complete vision loss in his right eye from previous retinal detachment presented with 20/200 vision in the left eye with a corneal ulcer. Culture was obtained, and the patient was started on fortified tobramycin, fortified vancomycin, and amphotericin. Despite the antibiotics, the patient did not significantly improve, after which another culture was obtained before the patient was taken to the surgery for cryotherapy and a partial conjunctival flap. The culture identified Chryseobacterium indologenes. There have been fewer than a handful of cases reported in the last three decades with different antibiotic susceptibility profiles. Our patient was successfully treated with ciprofloxacin and ceftazidime with the final vision of 20/40.

Chryseobacterium bacteraemia in a patient with heart failure: case report and literature review

Background

A 29-year-old male with recently diagnosed biventricular failure from myopericarditis and subsequent constrictive pericarditis on home milrinone presented to the Emergency Department with fevers/chills.

Case summary

On arrival to the Emergency Department, he was found to have septic shock and required vasopressor therapy. Chryseobacterium indologenes grew on his admission blood cultures, and he was treated with ciprofloxacin and piperacillin/tazobactam. He quickly improved, allowing for a successful pericardiectomy, was weaned off inotropes and discharged from the hospital.

Discussion

Chryseobacterium indologenes is an environmental Gram-negative rod found in groundwater. It is rarely associated with human infection, but is associated with indwelling lines and has been documented in immunocompromised patients. Treatment typically involves line removal and a fluoroquinolone or piperacillin/tazobactam; the most optimal antimicrobial regimen and duration of treatment are unknown.

Chryseobacterium indologenes, an Emerging Bacteria: A Case Report and Review of Literature

Chryseobacterium indologenes are aerobic, Gram negative, nonfermentative rods that are intrinsically multi-drug resistant. Reported infections include bacteremia, pneumonia, meningitis, myositis, keratitis, and indwelling devices. We present the clinical course of a 52-year-old African male with a medical history of end stage renal disease (ESRD) in hemodialysis with multiple episodes of central line-associated bloodstream infections (CLABSI) presenting with symptoms of chills, malaise, and localized erythema on insertion site of permacath. Blood cultures obtained from catheter showed C. indologenes. Successful response was obtained with piperacillin/tazobactam based on sensitivity and removal of indwelling catheter. Given the increase in the number of cases reported in the literature, guidelines for the management of this pathogen should be considered. 

Chryseobacterium spp-associated bacteraemia in a haemodialysis patient: a diagnostic challenge

Chryseobacterium species are Gram-negative bacillus widely distributed in nature. It is a rare human pathogen that has been isolated from water systems and humid surfaces of the hospital environment. We report a rare case of Chryseobacterium bacteremia in an end-stage renal disease nursing home resident, that was diagnosed using multiplex PCR and was successfully treated with intravenous piperacillin-tazobactam combination.

Bacteremia by Chryseobacterium indologenes in a Patient with Lung Cancer: A Clinical and Microbiological Investigation

We present a case of bacteremia by an unsual, instrinsically multidrug resistant organism, Chryseobacterium indologenes in a 59 year old gentleman with squamous cell carcinoma of lung with multiple metastasis. Despite of treating as per sensitivity report after isolatingChryseobacterium indologenes, patient could not be survived. The pathogenicity and predictability of the organism towards antibiotics, bothin vivo and in vitro needs further research.

How to cite this article

Bhagawati G, Bhardwaj A et al. Bacteremia by Chryseobacterium Indologenes in a Patient with Lung Cancer: A Clinical and Microbiological Investigation. Indian J Crit Care Med 2019;23(3):157-159.

Molecular Characterization of Chryseobacterium indologenes with Multidrug Resistance in the Brazilian Amazon Region

Chryseobacterium indologenes is an emerging nosocomial pathogen that produces IND-type chromosomal metallo-beta-lactamase. The phenotype and molecular aspects of two multidrug resistant C. indologenes strains and the analysis of the tertiary structure of the IND enzyme were studied. Identification of species and susceptibility tests were performed using the Vitek-2 compact. Chromosomal and plasmid DNA were extracted using PureLink™ Genomic DNA Mini Kit and PureLink Quick Plasmid Miniprep Kit, and the sequencing was performed using ABI 3130 genetic analyzer. Two strains were isolated and are registered as P-23 and P-113. Of the two, P-113 was sensitive to ciprofloxacin and cefepime only, whereas the P-23 showed reduced sensitivity to ceftazidime, ciprofloxacin, and tigecycline. The genetic analysis of both isolates identified the presence of the bla_IND-like gene, with similarity to IND-3 and IND-8 alleles. The IND-3 identified in the P-133 sample presented a single mutation at position T355G, which corresponds to a nonsynonymous substitution of the amino acid at position 119 (Ser→Ala). The phylogenetic analysis of INDs showed lineages that are circulating in Asian and European countries. These results emphasize the need for effective preventive actions to avoid the dissemination of this type of pathogen in the hospital environment.

Antarcticibacterium flavum gen. nov., sp. nov., isolated from marine sediment

A Gram-stain-negative, strictly aerobic, yellow-pigmented, non-gliding, oval to rod-shaped bacterial strain, designated JB01H24^T, belonging to the family Flavobacteriaceae, was isolated from marine surface sediment collected from the Ross Sea, Antarctica. Strain JB01H24^T grew at 4-40 °C (optimum 25-30 °C), pH 7.0-9.0 (optimum 7.5-8.0), and in the presence of 0-8 % NaCl (optimum 3 %, w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JB01H24^T formed an independent linkage within the family Flavobacteriaceae and was closely related with the genus Gillisia. Strain JB01H24^T exhibited 16S rRNA gene sequence similarities of 95.3-91.5 % and 94.9-94.0 % to the type strains of the genera Gillisia and Salinimicrobium, respectively. The major fatty acids (>5 %) were iso-C15 : 0, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), anteiso-C15 : 0, iso-C15 : 1 G and summed feature 9 (iso-C17 : 1ω9c and/or 10-methyl C16 : 0). The major polar lipids were phosphatidylethanolamine, seven unidentified lipids, two unidentified aminolipids and an unidentified aminophospholipid. Strain JB01H24^T contained menaquinone-6 as the only ubiquinone. The DNA G+C content was 42.4 mol%. On the basis of phylogenetic, physiological and chemotaxonomic properties, strain JB01H24^T is considered to represent a novel species of a new genus within the family Flavobacteriaceae, for which the name Antarcticibacterium flavum gen. nov., sp. nov. is proposed. The type strain of Antarcticibacterium flavum is JB01H24^T (=GDMCC 1.1229^T=KCTC 52984^T).

Arenibacter antarcticus sp. nov., isolated from marine sediment

A strictly aerobic, Gram-stain-negative, pale-golden, rod-shaped bacterium, designated as R18H21^T, was isolated from marine sediment collected from the Ross Sea, Antarctica. Strain R18H21^T grew at 4-40 °C (optimum 25 °C), at pH 6.3-9.2 (optimum 7.5-8.5) and in 0.5-6 % (w/v) NaCl (optimum 2 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain R18H21^T belonged to the genus Arenibacter, with the highest similarity to two type strains, Arenibacter latericius KMM 426^T (96.6 %) and Arenibacter certesii KMM 3941^T (96.6 %), and lower similarities (95.2-95.9 %) to five other members of the genus Arenibacter. The major fatty acids were iso-C17 : 0 3-OH, Summed Feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), iso-C15 : 0, iso-C15 : 1 G. The major polar lipids were phosphatidylethanolamine, an unidentified aminolipid and an unidentified phospholipid. The respiratory quinone of strain R18H21^T was menaquinone-6. The DNA G+C content was 40.0 mol%. Based on phylogenetic, physiological and chemotaxonomic features, strain R18H21^T has been classified as a novel species in the genus Arenibacter, for which the name Arenibacterantarcticus sp. nov. is proposed. The type strain of the novel species is R18H21^T (=GDMCC 1.1159^T=KCTC 52924^T).

In Vitro and In Vivo Control of Secondary Bacterial Infection Caused by Leishmania major

Bacterial infections of cutaneous leishmaniasis cause skin ulcers on mice, resulting in increased tissue deterioration, and these infections can be controlled with liquid allicin. To isolate and identify the incidences of real secondary bacterial infections in mice, we performed the current study by injecting mice (n = 50) with Leishmania major. L. major infections were initiated by an intramuscular injection of 0.1 mL Roswell Park Memorial Institute (RPMI 1640 media/mouse (107 promastigote/mL)). Scarring appeared 2-6 weeks after injection, and the bacteria were isolated from the skin ulcer tissues. Allicin (50 µL/mL) and ciprofloxacin (5 μg; Cip 5) were used for controlling L. major and bacteria. One hundred samples from skin ulcers of mice were examined, and 200 bacterial colonies were isolated. Forty-eight different genera and species were obtained and identified by Gram staining and physiological and biochemical characterization using identification kits. All samples were positive for secondary bacterial infections. Of the isolates, 79.16% were identified as Gram-negative bacteria, and 28.84% were identified as Gram-positive bacteria; only one yeast species was found. Interestingly, pure allicin liquid at a concentration 50 µL/mL exhibited antibacterial activity against a wide range of Gram-negative and some Gram-positive bacteria, in addition to yeast, and was 71.43% effective. Antimicrobial resistance patterns of all genera and species were determined using 15 different antibiotics. Allicin (50 µL/mL) and Cip 5 were the most effective against L. major and 92.30% of isolated bacteria. Stenotrophomonas maltophilia was the most resistant bacterium to the tested antibiotics with a survival rate of 73.33%, and it exhibited resistance to allicin.

Noncatheter-related bacteraemia due to Chryseobacterium indologenes in an immunocompetent patient

Chryseobacterium indologenes belongs to a group of nonfermentative Gram-negative bacilli and is an uncommon human pathogen. It causes severe infections such as septicaemia and ventilator-associated pneumonia in immunocompromised patients or after prolonged hospitalisation. We report a case of a noncatheter-related bacteraemia in a 22-year-old immunocompetent female whose blood culture showed the growth of C. indologenes, identified by Vitek GNI system (bioMerieux, France). The patient responded to treatment with ciprofloxacin. The pathogenicity and virulence factors of C. indologenes remain unclear. This case indicates that C. indologenes might cause symptomatic disease in immunocompetent persons with otherwise no associated underlying risk factors.

Chryseobacterium gleum pneumonia in an infant with nephrotic syndrome

INTRODUCTION

Chryseobacterium gleum is commonly distributed in the environment. It can cause a wide variety of infections in immunocompromised patients in hospital setting.

CASE PRESENTATION

A 6 month old infant with nephrotic syndrome was admitted to the emergency room for an acute onset of fever, difficulty breathing, cyanosis, and low oral intake. Cultures of endotracheal tube specimens were positive for Chryseobacterium gleum which was confirmed by ribosomal sequencing. The organism was susceptible to trimethoprim-sulfamethoxazole, minocycline, and levofloxacin. The patient clinically improved on levofloxacin treatment.

CONCLUSION

To the best of our knowledge, this is the first case of pneumonia caused by Chryseobacterium gleum in an infant with nephrotic syndrome. It is also the first report of C. gleum causing respiratory tract infection in Saudi Arabia.

Development of Culture Medium for the Isolation of Flavobacterium and Chryseobacterium from Rhizosphere Soil

An effective medium designated phosphate separately autoclaved Reasoner’s 2A supplemented with cycloheximide and tobramycin (PSR2A-C/T) has been developed for the isolation of Flavobacterium and Chryseobacterium strains from the plant rhizosphere. It consists of Reasoner’s 2A agar (R2A) prepared by autoclaving phosphate and agar separately and supplementing with 50 mg L⁻¹ cycloheximide and 1 mg L⁻¹ tobramycin. A comparison was made among the following nine media: PSR2A-C/T, PSR2A-C/T supplemented with NaCl, R2A agar, R2A agar supplemented with cycloheximide and tobramycin, 1/4-strength tryptic soy agar (TSA), 1/10-strength TSA, soil-extract agar, Schaedler anaerobe agar (SAA), and SAA supplemented with gramicidin, for the recovery of Flavobacterium and Chryseobacterium strains from the Welsh onion rhizosphere. Flavobacterium strains were only isolated on PSR2A-C/T, and the recovery rate of Chryseobacterium strains was higher from PSR2A-C/T than from the eight other media. In order to confirm the effectiveness of PSR2A-C/T, bacteria were isolated from onion rhizosphere soil with this medium. Flavobacterium and Chryseobacterium strains were successfully isolated from this sample at a similar rate to that from the Welsh onion rhizosphere.

Unforeseeable presentation of Chryseobacterium indologenes infection in a paediatric patient

Background

We report for the first time a case of community acquired Chryseobacterium indologenes soft tissue infection in an immunocompetent patient.

Case presentation

A 11 year female child, from South-Asia of Indian origin presented with fever, pain and swelling in right leg for 3 days with no significant past history. Incision and drainage was done and pus was sent for culture and sensitivity. Radiological investigation showed subtle irregular soft tissue density. Pus culture grew multidrug resistant C. indologenes.

Conclusion

Though of low pathogenicity, our case emphasises its unpredictable nature and the need to determine minimum inhibitory concentration breakpoints for therapy.

Chryseobacterium indologenes: an emerging infection in the USA

Nursing home-associated infections and antibiotic resistant pathogens constitute common and serious problems in the geriatric population.Chryseobacterium indologenes, a non-motile Gram-negative rod, though widely distributed in nature, is an uncommon human pathogen. Typically thought of as an organism of low virulence, it may cause serious infections, particularly among the immunocompromised. The majority of reported cases are nosocomial, often associated with immunosuppression or indwelling catheters. It has been reported as the causative agent in bacteraemia, peritonitis, pneumonia, empyema, pyelonephritis, cystitis, meningitis and central venous catheter-associated infections. We report a rare case of C. indologenesinfection affecting a nursing home resident in the USA and we provide a review of similar cases. This report emphasises the importance of individualised treatment and promotes awareness about this organism as one of several emerging pathogens in immunocompromised adults and in the frail elderly who are often nursing home residents, in the Western Hemisphere.

Whole genome sequencing for deciphering the resistome of Chryseobacterium indologenes, an emerging multidrug-resistant bacterium isolated from a cystic fibrosis patient in Marseille, France

We decipher the resistome of Chryseobacterium indologenes MARS15, an emerging multidrug-resistant clinical strain, using the whole genome sequencing strategy. The bacterium was isolated from the sputum of a hospitalized patient with cystic fibrosis in the Timone Hospital in Marseille, France. Genome sequencing was done with Illumina MiSeq using a paired-end strategy. The in silico analysis was done by RAST, the resistome by the ARG-ANNOT database and detection of polyketide synthase (PKS) by ANTISMAH. The genome size of C. indologenes MARS15 is 4 972 580 bp with 36.4% GC content. This multidrug-resistant bacterium was resistant to all β-lactams, including imipenem, and also to colistin. The resistome of C. indologenes MARS15 includes Ambler class A and B β-lactams encoding bla_CIA and bla_IND-2 genes and MBL (metallo-β-lactamase) genes, the CAT (chloramphenicol acetyltransferase) gene and the multidrug efflux pump AcrB. Specific features include the presence of an urease operon, an intact prophage and a carotenoid biosynthesis pathway. Interestingly, we report for the first time in C. indologenes a PKS cluster that might be responsible for secondary metabolite biosynthesis, similar to erythromycin. The whole genome sequence analysis provides insight into the resistome and the discovery of new details, such as the PKS cluster.

A Case of Healthcare Associated Pneumonia Caused by Chryseobacterium indologenes in an Immunocompetent Patient

Chryseobacterium indologenes is nonmotile, oxidase, and indole positive Gram-negative aerobic bacilli which is widely found in plants, soil, foodstuffs, and water. It can colonize hospital environment due to ability to survive in chlorine-treated water supplies. Chryseobacteria can also colonize patients via contaminated medical devices such as respirators, intubation tubes, humidifiers, intravascular catheters, and prosthetic valves. Immune suppression, comorbidities, use of broad-spectrum antibiotics, and extreme age are other important risk factors for Chryseobacterium infections. We report a case of an 82-year-old male admitted to our hospital with the complaint of altered mental status with history of trauma, and recent orthopedic and neurosurgery operations. He was transferred to neurosurgery intensive care unit due to respiratory failure. Urine culture yielded extended spectrum beta lactamase (ESBL) (+). E. coli and C. indologenes were isolated from transtracheal aspirate. He was treated with ertapenem, and levofloxacin and discharged with full recovery.

Chryseobacterium indologenes pneumonia in a patient with non-Hodgkin's lymphoma

A 42-year-old man diagnosed with gastric non-Hodgkin's lymphoma 2 years earlier, for which he had undergone treatment, presented with expectorative cough, exertional shortness of breath and left-sided chest pain of 3 months duration. Respiratory system examination was suggestive of left-sided pneumonia with pleural effusion. Routine haemogram showed leukocytosis with high erythrocyte sedimentation rate. Chest radiograph showed blunting of left-sided cardiophrenic angle. Sputum culture grew Chryseobacterium indologenes. Diagnostic thoracocentesis was suggestive of lymphomatous metastasis. Pleural fluid culture was sterile. Contrast-enhanced CT (CECT) of the thorax showed left lower lobe consolidation with bilateral pleural effusion. The patient was treated with antibiotics, following which his cough improved and total leukocyte count normalised. Sputum culture repeated after the antibiotic course showed no growth of C. indologenes. However, the pleural effusion soon aggravated along with features suggestive of multiple metastasis. The patient finally succumbed to his underlying advanced malignancy.

Transient bacteraemia due to Chryseobacterium indologenes in an immunocompetent patient: a case report and literature review

A 51-year-old woman was admitted to the emergency unit with diffuse headache, visus reduction, and paraesthesias of the trigeminal area and the left hand. Three days after admission she showed shaking chills, vomiting, and sudden onset of fever (39·4°C). Blood cultures were performed soon after fever onset. Fever persisted for the whole day, decreasing slowly after 12 hours. No empirical antibiotic treatment was started in order to better define the diagnosis. Fever completely disappeared the day after. Two blood cultures for aerobes were positive for Chryseobacterium indologenes. The patient was discharged with the diagnosis of transient bacteraemia and transferred to the neurology unit for further investigations. C. indologenes infections are described in 31 studies with a total of 171 cases (pneumonia and bacteraemia being the most frequent). Our case is the first report of transient bacteraemia caused by C. indologenes in an immunocompetent, non-elderly patient without needing medical devices.

Chryseobacterium indologenes Septicemia in an Infant

Chryseobacterium indologenes is a rare cause of infection in children. The organism causes infections mostly in hospitalised patients with severe underlying diseases. The choice of an effective drug for the treatment of infections due to C. indologenes is difficult as the organism has a limited spectrum of antimicrobial sensitivity. We present a case of nosocomial septicemia caused by C. indologenes in an infant with congenital heart disease who was successfully treated with trimethoprim sulfamethoxazole and also reviewed fourteen additional cases of C. indologenes infections reported in the English literature in this report.

Chryseobacterium indologenes in a woman with acute leukemia in Senegal: a case report

INTRODUCTION

This report documents a rare case of Chryseobacterium indologenes urinary tract infection in Senegal. Chryseobacterium indologenes is an uncommon human pathogen reported in hospital outbreaks in Taiwan and there have been some sporadic cases reported in Europe and in the USA mainly from immune-suppressed patients.

CASE PRESENTATION

This case report describes a 42-year-old woman of Wolofa ethnicity who was hospitalized in our Department of Internal Medicine in a Senegalese university teaching hospital, with acute leukemia who died of severe sepsis 10 days following her hospitalization. A strain of Chryseobacterium indologenes isolated from her urine sample was resistant to several beta-lactams including ampicillin (minimum inhibitory concentrations ≥ 256 μg/mL), cefotaxime (minimum inhibitory concentrations 32 μg/mL) and imipenem (minimum inhibitory concentrations ≥ 32 μg/mL), whereas it was susceptible to piperacillin (minimum inhibitory concentrations 16 μg/mL), cefepime (minimum inhibitory concentrations 4 μg/mL), ceftazidime (minimum inhibitory concentrations 4 μg/mL), trimethoprim-sulfamethoxazole (minimum inhibitory concentrations ≤ 0.25 μg/mL) and all tested quinolones including nalidixic acid (minimum inhibitory concentrations ≤ 2 μg/mL).

CONCLUSIONS

Chryseobacterium indologenes although uncommon, is an important pathogen causing infection in hospitalized patients. The management of this infection needs better identification, drug susceptibility testing and monitoring of immunosuppressed patients with long hospitalizations.

Treatment of Chryseobacterium indologenes ventilator-associated pneumonia in a critically ill trauma patient

OBJECTIVE

To report a case of Chryseobacterium indologenes ventilator-associated pneumonia (VAP) in a critically ill trauma patient.

CASE SUMMARY

This report describes a 66-year-old critically ill trauma patient who developed VAP, which was caused by C indologenes. The patient was injured in a riding lawn mower accident that trapped him underwater in a pond. The patient required surgery for intra-abdominal injuries and was mechanically ventilated in the trauma intensive care unit. On hospital day 5, the patient developed signs and symptoms of VAP. A diagnosis of C indologenes VAP was confirmed based on a quantitative culture from a bronchoscopic bronchoalveolar lavage. The patient's infection was successfully treated with moxifloxacin for 2 days followed by cefepime for 7 days.

DISCUSSION

Formally known as Flavobacterium indologenes, C indologenes is a Gram-negative bacillus normally found in plants, soil, foodstuffs, and fresh and marine water sources. Recently, worldwide reports of C indologenes infections in humans have been increasing, though reports from the United States are still rare. Bacteremia and pneumonia are the most commonly reported infections, and most patients are immunocompromised. The current case differs from most previous reports because this patient was in the United States and did not have any traditional immunocompromised states (eg, transplant, cancer, HIV/AIDS, or corticosteroid use).

CONCLUSION

This case report demonstrates that C indologenes can cause VAP in a trauma ICU patient.

Chryseobacterium indologenes in a woman with metastatic breast cancer in the United States of America: a case report

Introduction

We report the seventh case of Chryseobacterium indologenes occurring in the United States of America. C. indologenes is seldom isolated from clinical specimens but has caused hospital-acquired infections in Taiwan and rarely elsewhere.

Case presentation

A 32-year-old Caucasian woman with metastatic breast cancer presented to a hospital emergency department with bilateral radiation-induced pleural effusions and respiratory failure. The patient was hospitalized and ventilated for 26 days; tracheal aspirates collected on ventilation days 24 and 26 grew C. indologenes. The patient subsequently died as a result of worsening ventilator-associated pneumonia and stage IV breast cancer.

Conclusions

C. indologenes infection should be considered for hospitalized patients with a history of malignancy, especially those with indwelling devices and antibiotic use for >14 days.

Chryseobacterium indologenes central nervous system infection in infancy: an emergent pathogen?

The isolation of Chryseobacterium indologenes as a causative micro-organism in human diseases is rare. Risk factors for infections caused by this pathogen include very young and very old age, indwelling devices, immune suppression and recent use of broad-spectrum antibiotics. Most cases suffer from bacteraemia or nosocomial pneumonia, whilst infection of the central nervous system (CNS) is extremely rare. We present a term-born infant diagnosed prenatally with holoprosencephaly and obstructive hydrocephalus, requiring post-natal ventriculoperitoneal shunt insertion. At 6 weeks of age, he suffered from Escherichia coli meningitis, showing satisfactory clinical response with antimicrobial therapy. Aged 11 months, he suffered from hyper-drainage syndrome, resulting in the removal of the shunt system. He represented 11 days post-operatively, with low-grade fever, irritability and cerebrospinal fluid (CSF) leakage. C. indologenes from CSF was isolated and antimicrobial therapy with ceftazidime and trimethoprim-sulfamethoxazole for 3 weeks resulted in good clinical response. This is the first documented community-acquired CNS infection due to C. indologenes in an infant without concomitant indwelling device or previous antibiotic pressure.

Recurrent port infection due to chryseobacterium indologenes

Infections due to Chryseobacterium indologenes (C. indologenes) are rare and generally associated with immunosupression and indwelling catheters. We report a recurrent port infection caused by C. indologenes. In the first bacteremia episode we did not remove the port and only applied antibiotherapy. However, the patient presented with bacteremia with the same bacteria and successfully treated with antibiotherapy and removal of the port.

Chryseobacterium indologenes subcutaneous port-related bacteremia in a liver transplant patient

Chryseobacterium indologenes is a rare cause of infection in select immunosuppressed hosts. Most prior reports are from Taiwan, in patients with diabetes mellitus or malignancies. Infections caused by C. indologenes are generally associated with indwelling devices, and the organism may be resistant to many commonly utilized broad-spectrum antibiotics. We report the first case, to our knowledge, of C. indologenes subcutaneous port-related bacteremia in a liver transplant recipient. The isolates were resistant to antibiotics previously reported as active, and device removal was required for treatment success.

Non catheter-related bacteremia caused by Pseudomonas oryzihabitans in an adolescent with chronic renal failure undergoing peritoneal dialysis

A Pseudomonas oryzihabitans clinical isolate was recovered from a blood sample. The patient, a 14-year-old-adolescent underwent parathyroidectomy due to secondary hyperparathyroidism. The patient had been going peritoneal dialysis because of chronic renal failure. According to the susceptibility testing conducted with phenotypic methods the microorganism was sensitive to the vast majority of the antibiotics. The isolation of this rare species of Pseudomonas combined with the patient's medical history stimulated as to focus on the causes of the bacteremia, which was non catheter-related.

Clinical and microbiological characteristics of Chryseobacterium indologenes bacteremia

BACKGROUND/PURPOSE

Reports detailing bacteremia caused by Chryseobacterium indologenes remain limited, with most cases reported in Taiwan. The clinical significance of C. indologenes has not been fully established. This retrospective study investigated the clinical features and antimicrobial susceptibility of C. indologenes bacteremia.

METHODS

Patients with C. indologenes bacteremia were identified at a medical center/teaching hospital in northern Taiwan between January 1, 2004 and January 31, 2008. Clinical features and the antimicrobial susceptibilities of these patients were analyzed.

RESULTS

Sixteen isolates of C. indologenes from 16 episodes in 16 patients were identified, with all patients having underlying diseases. Two patients (12.5%) had polymicrobial bacteremia. The portal of bacteremia was not determined in most cases. Other clinical syndromes included catheter-related bacteremia, urinary tract infection and peritonitis. The majority of patients had undergone invasive procedures. Other associated conditions included immunosuppression, neutropenia and prolonged use of antibiotics. Only three patients were treated with appropriate antibiotics according to minimum inhibitory concentrations. The susceptibilities of isolates to trimethoprim-sulfamethoxazole (75.0%), levofloxacin (62.5%), piperacillin-tazobactam (50.0%), ciprofloxacin (43.75%) and cefepime (12.5%) were variable and the bacteremia-related mortality rate was 6.25%.

CONCLUSION

C. indologenes isolates are resistant to multiple antibiotics, with newer fluoroquinolones and trimethoprim-sulfamethoxazole possibly representing the most appropriate antimicrobial agents to treat infections caused by this pathogen. However, the pathogenicity and factors of virulence for C. indologenes remain unclear, with our study revealing favorable outcomes of C. indologenes bacteremia. Epidemiological surveillance of this organism in Taiwan and extensive worldwide surveillance programs are required.

Chryseobacterium indologenes infection in a newborn: a case report

Introduction

Chryseobacterium indologenes is an uncommon human pathogen. Most infections have been detected in hospitalized patients with severe underlying diseases who had indwelling devices implanted. Infection caused by C. indologenes in a newborn has not been previously reported.

Case presentation

We present a case of ventilator-associated pneumonia caused by C. indologenes in a full-term Caucasian newborn baby boy with congenital heart disease who was successfully treated with piperacillin-tazobactam.

Conclusion

C. indologenes should be considered as a potential pathogen in newborns in the presence of invasive equipment or treatment with long-term broad-spectrum antibiotics. Appropriate choice of effective antimicrobial agents for treatment is difficult because of the unpredictability and breadth of antimicrobial resistance of these organisms, which often involves resistance to many of the antibiotics chosen empirically for serious Gram-negative infections.

Arenibacter nanhaiticus sp. nov., isolated from marine sediment of the South China Sea

An aerobic, Gram-stain-negative, rod-shaped bacterial isolate, strain NH36AT, was isolated from a sandy sediment sample from the South China Sea. Colonies of the isolate were dark orange on M2 agar. Optimal growth was observed at pH 7.0–8.5, 30 °C and in the presence of 0.5–4.0 % (w/v) NaCl. The major fatty acids were C15 : 0, iso-C15 : 0, anteiso-C15 : 0, iso-C15 : 1, iso-C15 : 0 3-OH, iso-C17 : 0 3-OH and summed feature 3 (comprising iso-C15 : 0 2-OH and/or C16 : 1 ω7c). The DNA G+C content was 38.9 mol%. 16S rRNA gene sequence analysis revealed that strain NH36AT was most closely related to members of the genus Arenibacter, exhibiting 94.3–96.2 % sequence similarity to the type strains of Arenibacter species. On the basis of phenotypic, chemotaxonomic and phylogenetic data, this organism should be classified as a representative of a novel species in the genus Arenibacter. The name Arenibacter nanhaiticus sp. nov. is proposed and the type strain is NH36AT (=LMG 24842T=CCTCC AB 208315T=MCCC 1A04137T).

Chryseobacterium indologenes bacteremia in an infant

Chryseobacterium species are a rare cause of human disease and are usually associated with indwelling devices or altered immune status. This is the first case to our knowledge, of Chryseobacterium indologenes bacteremia in a previously healthy infant. Chryseobacteria are pathogens resistant to the usual empiric treatments for neonatal or infantile septicemia.

Une forme sévère de pneumopathie à Chryseobacterium indologenes chez l'immunocompétent

We report a case of severe pneumonia due to Chryseobacterium indologenes in an immunocompetent patient. Chryseobacterium indologenes (formerly Flavobacterium indologenes) are saprophytic Gram-negative rods widely distributed in damp environment. Many sites of infection were described in the literature. These infections are always severe sometimes associated to multiple organ failure. The evolution is usually favorable with antibiotic treatment. Bacteria characteristically grow as yellow-pigmented colonies. They are naturally resistant to many antimicrobial agents. They are usually susceptible to piperacillin(DCI) alone or combined with tazobactam(DCI), ceftazidime(DCI), cefepime(DCI), fluoroquinolones(DCI), rifampin(DCI) and cotrimoxazole(DCI), but the in vitro susceptibility to these antibiotics should be systematically tested. Nevertheless, the optimum antibiotic treatment for Chryseobacterium-related infections remains to be established. In the case we report, the diagnosis was made according to the results of bronchial sample bacterial culture. This case report underlines the need for specific management of patients infected with this species.

Lumboperitonial shunt infection due to Chryseobacterium indologenes

Chryseobacterium indologenes central nervous system infection has not been reported. We present a case of lumboperitoneal shunt infection caused by C. indologenes successfully treated with trimethoprim-sulfamethoxazole and rifampin in a pediatric patient. Forty-three additional cases of C. indologenes non-central nervous system infections reported in the English medical literature were reviewed. Risk factors for C. indologenes infections include underlying medical illnesses, underlying immunocompromising conditions and presence of indwelling intravascular devices.