Comparison of clinical characteristics of bacteremia from Elizabethkingia meningoseptica and other carbapenem-resistant, non-fermenting Gram-negative bacilli at a tertiary medical center.

BACKGROUND: Acquired carbapenem resistance among non-fermenting Gram-negative bacilli (NFGNB), such as Pseudomonas aeruginosa and Acinetobacter calcoaceticus-Acinetobacter baumannii complex (ACB complex), is a serious problem in nosocomial infections. We previously reported that patients infected with the intrinsically carbapenem-resistant Elizabethkingia meningoseptica were associated with high mortality. However, little information is available regarding the clinical outcome of E. meningoseptica bacteremia when compared to that of other carbapenem-resistant NFGNB. METHODS: We conducted an observational study that included consecutive patients with E. meningoseptica, carbapenem-resistant ACB complex, carbapenem-resistant P. aeruginosa, and Stenotrophomonas maltophilia bacteremia at a Taiwanese medical center in 2015. We compared the clinical characteristics and outcomes between patients with E. meningoseptica bacteremia and those with other carbapenem-resistant NFGNB bacteremia. RESULTS: We identified 30 patients with E. meningoseptica, 71 with carbapenem-resistant ACB complex, 25 with S. maltophilia, and 17 with carbapenem-resistant P. aeruginosa bacteremia. The clinical characteristics, disease severity, and previous antibiotic exposures were similar between patients with bacteremia either due to E. meningoseptica or other carbapenem-resistant NFGNB. Patients with E. meningoseptica bacteremia had a higher rate of appropriate empirical antibiotics than those with other carbapenem-resistant NFGNB and was less associated with central venous catheterization. The 28-day mortality rates were similar between patients with E. meningoseptica and the other carbapenem-resistant NFGNB bacteremia (46.7% vs 46%, p = 0.949). CONCLUSION: The mortality rate of E. meningoseptica bacteremia was as high as other carbapenem-resistant NFGNB infections. The emerging E. meningoseptica infection calls for active surveillance and continued awareness from clinical physicians for this serious carbapenem-resistant infection.

Genomic insights into the evolution and ecology of botulinum neurotoxins.

Clostridial neurotoxins, which include botulinum neurotoxins (BoNTs) and tetanus neurotoxins, have evolved a remarkably sophisticated structure and molecular mechanism fine-tuned for the targeting and cleavage of vertebrate neuron substrates leading to muscular paralysis. How and why did this toxin evolve? From which ancestral proteins are BoNTs derived? And what is, or was, the primary ecological role of BoNTs in the environment? In this article, we examine these questions in light of recent studies identifying homologs of BoNTs in the genomes of non-clostridial bacteria, including Weissella, Enterococcus and Chryseobacterium. Genomic and phylogenetic analysis of these more distantly related toxins suggests that they are derived from ancient toxin lineages that predate the evolution of BoNTs and are not limited to the Clostridium genus. We propose that BoNTs have therefore evolved from a precursor family of BoNT-like toxins, and ultimately from non-neurospecific toxins that cleaved different substrates (possibly non-neuronal SNAREs). Comparison of BoNTs with these related toxins reveals several unique molecular features that underlie the evolution of BoNT's unique function, including functional shifts involving all four domains, and gain of the BoNT gene cluster associated proteins. BoNTs then diversified to produce the existing serotypes, including TeNT, and underwent repeated substrate shifts from ancestral VAMP2 specificity to SNAP25 specificity at least three times in their history. Finally, similar to previous proposals, we suggest that one ecological role of BoNTs could be to create a paralytic phase in vertebrate decomposition, which provides a competitive advantage for necrophagous scavengers that in turn facilitate the spread of Clostridium botulinum and its toxin.

Microbial associates of the southern mole cricket (Scapteriscus borellii) are highly pathogenic.

We report the isolation and identification of seven bacterial strains and one fungal strain from dead and diseased Scapteriscus borellii mole crickets collected from a golf course in southern California. Using 16S and 18S rRNA gene sequence analysis we identified the microbes as Serratia marcescens (red), S. marcescens (white), S. marcescens (purple), Achromobacter xylosoxidans, Chryseobacterium sp., Ochrobactrum anthropi, Tsukamurella tryosinosolvens, and Beauveria bassiana. We performed a dose response curve for each of these cricket-associated microbial strains (except T. tryosinosolvens) and two other strains of S. marcescens (DB1140 and ATCC 13880). We found that all of these microbes except O. anthropi were highly pathogenic to D. melanogaster compared to the other strains of S. marcescens. Injecting the mole cricket associated strains of Serratia into flies killed all infected flies in ≤24h. For all other strains, the median time to death of injected flies varied in a dose-dependent manner. In vivo growth assessments of these microbes suggested that the host immune system was quickly overcome. We used disease tolerance curves to better understand the host-microbe interactions. Further studies are necessary to understand in mechanistic detail the virulence mechanisms of these mole cricket associated microbes and how this association may have influenced the evolution of mole cricket immunity.

Chryseobacterium gleum in a man with prostatectomy in Senegal: a case report and review of the literature.

BACKGROUND: Here we report a rare case of a urinary tract infection due to Chryseobacterium gleum. This widely distributed Gram-negative bacillus is an uncommon human pathogen and is typically associated with health care settings. CASE PRESENTATION: We describe a case of urinary tract infection caused by Chryseobacterium gleum in a 68-year-old man of Wolof ethnicity (an ethnic group in Senegal, West Africa) who presented to our Department of Urology in a university teaching hospital (Hôpital Aristide Le Dantec) in Dakar, Senegal, 1 month after prostatectomy. The strain isolated from a urine sample was identified as Chryseobacterium gleum by mass spectrometry (Vitek matrix-assisted laser desorption/ionization, time-of-flight, bioMérieux) and confirmed by 16S ribosomal ribonucleic acid sequencing. The organism was resistant to a wide range of antibiotics, including carbapenem, due to a resident metallo-ß-lactamase gene that shared 99% of amino-acid identity with Chryseobacterium gleum class B enzym. CONCLUSIONS: Infection by Chryseobacterium gleum is infrequent, and no such case has been previously reported in Africa. Despite its low virulence, Chryseobacterium gleum should be considered a potential opportunistic and emerging pathogen. Further studies on the epidemiology, pathogenicity, and resistance mechanisms of Chryseobacterium gleum are needed for better diagnosis and management.

Immune tolerance to an intestine-adapted bacteria, Chryseobacterium sp., injected into the hemocoel of Protaetia brevitarsis seulensis.

To explore the interaction of gut microbes and the host immune system, bacteria were isolated from the gut of Protaetia brevitarsis seulensis larvae. Chryseobacterium sp., Bacillus subtilis, Arthrobacter arilaitensis, Bacillus amyloliquefaciens, Bacillus megaterium, and Lysinibacillus xylanilyticus were cultured in vitro, identified, and injected in the hemocoel of P. brevitarsis seulensis larvae, respectively. There were no significant changes in phagocytosis-associated lysosomal formation or pathogen-related autophagosome in immune cells (granulocytes) from Chryseobacterium sp.-challenged larvae. Next, we examined changes in the transcription of innate immune genes such as peptidoglycan recognition proteins and antimicrobial peptides following infection with Chryseobacterium sp. PGRP-1 and -2 transcripts, which may be associated with melanization generated by prophenoloxidase (PPO), were either highly or moderately expressed at 24 h post-infection with Chryseobacterium sp. However, PGRP-SC2 transcripts, which code for bactericidal amidases, were expressed at low levels. With respect to antimicrobial peptides, only coleoptericin was moderately expressed in Chryseobacterium sp.-challenged larvae, suggesting maintenance of an optimum number of Chryseobacterium sp. All examined genes were expressed at significantly higher levels in larvae challenged with a pathogenic bacterium. Our data demonstrated that gut-inhabiting bacteria, the Chryseobacterium sp., induced a weaker immune response than other pathogenic bacteria, E. coli K12.

Neumonía por Chryseobacterium indologenes asociada a ventilación mecánica / Ventilator-associated pneumonia by Chryseobacterium indologenes

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Clinical outcomes in cystic fibrosis patients with Trichosporon respiratory infection.

BACKGROUND: Relationships between clinical outcomes and novel respiratory pathogens such as Trichosporon are not well understood. METHODS: Respiratory cultures from CF patients were screened for novel pathogens Trichosporon and Chryseobacterium as well as other pathogens over 28months. Relationships between microbiologic and clinical data were assessed using univariate and multivariate methods. RESULTS: Of 4934 respiratory cultures from 474 CF patients, 37 cultures from 10 patients were Trichosporon positive. Patients with positive Trichosproron cultures had a greater decline in FEV1 over time (-3.9%/year vs. -1.3%/year, p<0.05), whereas Chryseobacterium did not influence lung function. These findings were confirmed in multivariate analyses that included age, gender, and other common pathogens as confounders. Treatment of Trichosporon infected patients was associated with improved lung function. CONCLUSIONS: Trichosporon can be recovered from a small but clinically meaningful fraction of CF patients. The presence of Trichosporon, but not Chryseobacterium, is associated with greater declines in lung function.

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 spp., ¿nuevo patógeno oportunista asociado a fibrosis quística? / Chryseobacterium spp., a new opportunistic pathogen associated with cystic fibrosis?

INTRODUCCIÓN: En los últimos años se ha incrementado el aislamiento de bacilos gramnegativos no fermentadores en los pacientes con fibrosis quística (FQ). En el presente trabajo se registra la frecuencia de aislamientos de Chryseobacterium spp., analizándose sus características, patrones de resistencia y evolución clínica de los pacientes con FQ de nuestra unidad. MÉTODOS: Se recogieron todos los aislamientos respiratorios de Chryseobacterium spp. de los pacientes atendidos en la unidad de FQ del Hospital de la Princesa durante 3años (marzo 2009-marzo 2012). Para su identificación fenotípica y genotípica y para el estudio de sensibilidad se empleó metodología convencional. Para la valoración de la función pulmonar de los pacientes se tuvo en cuenta el volumen espirado forzado en el primer segundo (FEV1) y los resultados se analizaron con el paquete estadístico SPSS. RESULTADOS: Se constató un aumento en la incidencia de Chryseobacterium spp., obteniéndose 17 aislamientos pertenecientes a 9 pacientes. Tres enfermos presentaron colonización crónica por este microorganismo y uno de ellos mostró un deterioro significativo de la función pulmonar. En 7 de los pacientes existió co-colonización con Staphylococcus aureus, y con Pseudomonas aeruginosa en 4 de ellos. CONCLUSIÓN: Chryseobacterium spp. debe ser considerado como un nuevo patógeno oportunista emergente en pacientes con FQ. Es imprescindible una vigilancia microbiológica y clínica de este grupo de pacientes para detectar la colonización por Chryseobacterium spp. y poder evitar la infección crónica. En estas circunstancias, y aunque se desconoce su implicación clínica, se debe valorar su posible erradicación, siendo el cotrimoxazol la mejor opción terapéutica

INTRODUCTION: There is an increase in the isolation of non-fermenting gramnegative bacilli in patients with cystic fibrosis (CF). The present study evaluates the frequency of isolates of Chryseobacterium spp., analyzing its characteristics, resistance patterns and clinical outcome of patients. METHODS: It has been collected all respiratory isolates of Chryseobacterium spp. of patients attended in the CF unit of Hospital de la Princesa for three years (march 2009-march 2012). For phenotypic and genotypic identification and sensitivity study conventional methodology was used. For the assessment of the patients lung function was considered the forced expiratory volume in one second (FEV1) and the results were analyzed with SPSS. RESULTS: There was an increase in the incidence of Chryseobacterium spp. with 17 isolates from 9 patients. Three patients had chronic colonization by this microorganism and one showed significant impairment of lung function. Seven patients showed also colonization with Staphylococcus aureus and 4 of them with Pseudomonas aeruginosa. CONCLUSION: Chryseobacterium spp. should be considered as a new emerging opportunistic pathogen in patients with CF. It is essential the clinical and microbiological monitoring of this group of patients for detection of Chryseobacterium spp. colonization and to prevent the chronic infection. In these circumstances it must assess its possible eradication, though its clinical impact is unknown. Cotrimoxazole being the best treatment option

[Chryseobacterium spp., a new opportunistic pathogen associated with cystic fibrosis?]. / Chryseobacterium spp., ¿nuevo patógeno oportunista asociado a fibrosis quística?

INTRODUCTION: There is an increase in the isolation of non-fermenting gramnegative bacilli in patients with cystic fibrosis (CF). The present study evaluates the frequency of isolates of Chryseobacterium spp., analyzing its characteristics, resistance patterns and clinical outcome of patients. METHODS: It has been collected all respiratory isolates of Chryseobacterium spp. of patients attended in the CF unit of Hospital de la Princesa for three years (march 2009-march 2012). For phenotypic and genotypic identification and sensitivity study conventional methodology was used. For the assessment of the patients lung function was considered the forced expiratory volume in one second (FEV1) and the results were analyzed with SPSS. RESULTS: There was an increase in the incidence of Chryseobacterium spp. with 17 isolates from 9 patients. Three patients had chronic colonization by this microorganism and one showed significant impairment of lung function. Seven patients showed also colonization with Staphylococcus aureus and 4 of them with Pseudomonas aeruginosa. CONCLUSION: Chryseobacterium spp. should be considered as a new emerging opportunistic pathogen in patients with CF. It is essential the clinical and microbiological monitoring of this group of patients for detection of Chryseobacterium spp. colonization and to prevent the chronic infection. In these circumstances it must assess its possible eradication, though its clinical impact is unknown. Cotrimoxazole being the best treatment option.

Identification and virulence of Chryseobacterium indologenes isolated from diseased yellow perch (Perca flavescens).

AIM: To identify pathogen of diseased yellow perch and determine their virulence. METHODS AND RESULTS: Fifteen Gram-negative bacterial isolates were recovered from the skin lesions of diseased yellow perch (Perca flavescens). Based on API 20NE test, ten isolates were found to share 67.2-99.9% homologies with Chryseobactertium indologenes. Based on fatty acid methyl ester analysis, 13 isolates were found to share similarities with C. indologenes and other species of Chryseobacterium. Based on sequencing results of partial 16S rRNA gene, 13 isolates shared 99% identities (e value = 2e-50) with the 16S rRNA sequence of C. indologenes (GenBank HQ259684). Based on the 16S-23S rRNA intergenic spacer region (ISR) sequence, the 13 isolates shared 88% identity (e value = 1e-165) with the 16S-23S ISR sequence of C. indologenes (GenBank EU014570). T-coffee multiple sequence alignment revealed that the partial 16S rRNA or the 16S-23S ISR sequence of the 13 isolates shared 100% identity with each other. When healthy yellow perch were exposed to the 15 isolates by bath immersion (c. 6 × 10(7) CFU ml(-1) for 1 h), only C. indologenes isolates killed 10-20% of fish, whereas other isolates were avirulent. When yellow perch were exposed to C. indologenes by intraperitoneal injection, mortality was dose dependent, with LD(50) and LD(95) values of 1.5 × 10(8) and 3.2 × 10(8) CFU per fish, respectively. CONCLUSIONS: Chryseobactertium indologenes could be pathogenic to yellow perch. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report on the isolation of C. indologenes from diseased yellow perch. Virulence studies suggested that C. indologenes could become pathogenic to yellow perch.

Functional genomics of tick thioester-containing proteins reveal the ancient origin of the complement system.

Ticks are important ectoparasites and vectors of multiple human and animal diseases. The obligatory hemophagy of ticks provides a formidable route for parasite transmission from one host to another. Parasite survival inside the tick relies on the ability of a pathogen to escape or inhibit tick immune defenses, but the molecular interactions between the tick and its pathogens remain poorly understood. Here we report that tick genomes are unique in that they contain all known classes of the α(2)-macroglobulin family (α(2)M-F) proteins: α(2)-macroglobulin pan-protease inhibitors, C3 complement components, and insect thioester-containing and macroglobulin-related proteins. By using RNA interference-mediated gene silencing in the hard tick Ixodes ricinus we demonstrated the central role of a C3-like molecule in the phagocytosis of bacteria and revealed nonredundant functions for α(2)M-F proteins. Assessment of α(2)M-F functions in a single organism should significantly contribute to the general knowledge on the evolution and function of the complement system. Importantly, understanding the tick immune mechanisms should provide new concepts for efficient transmission blocking of tick-borne diseases.

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.

First isolation and identification of Elizabethkingia meningoseptica from cultured tiger frog, Rana tigerina rugulosa.

Elizabethkingia meningoseptica has been recognised as an occasional but serious opportunistic bacterial pathogen to human beings. Recently, it was frequently isolated from tiger frog, Rana tigerina rugulosa, with cataract disease, which is the most common disease of unknown aetiology of frogs in Hainan, China. The purpose of this study was to identify and characterise the bacterial strains isolated from the recent outbreaks of cataract disease in farmed tiger frog in Hainan, China, and to evaluate their pathogenicity to the frog and their sensitivity to 20 chemotherapeutic agents. The 16S rRNA gene sequences of strains W0701 (1478bp), W0702 (1477bp) and W0703 (1478bp) showed 98.6-98.7% similarity with the sequence of E. meningoseptica type strain (ATCC 13253) and 99.9-100% similarity with that of E. meningoseptica NTU 870424-IL. Six strains (W0701-W0706) were selected to represent 24 isolates retrieved from six moribund frogs. The morphological, physiological and biochemical characteristics of the six representative isolates were consistent with those of E. meningoseptica strains. The organisms were only susceptible to vancomycin and moderately susceptible to cefoperazone among the 20 investigated chemotherapeutic agents. Virulence test with strain W0702 was conducted and pathogenicity (by intramuscular injection) was demonstrated in the tiger frog. In conclusion, 24 isolates obtained from frogs with cataract disease were the E. meningoseptica strains highly pathogenic to tiger frog, and this is the first report of E. meningoseptica as a pathogen for tiger frog.

Studies on the non-pathogenicity of Chryseobacterium proteolyticum and on the safety of the enzyme: protein-glutaminase.

Protein-glutaminase (PG) is a protein-deamidating enzyme produced from the microorganism Chryseobacterium proteolyticum strain 9670. Food safety studies were conducted on both the enzyme and the production organism. The strain was evaluated for pathogenicity and toxigenicity by intravenous and oral inoculation studies in Slc:ICR male SPF mice. The results demonstrate that the tested C. proteolyticum strain is of very low pathogenicity comparable to known food source bacterial strains and is very unlikely to demonstrate any pathogenicity in animals or humans. The level of endotoxin is very low and typical of the endotoxin levels in drinking water and teas. A 90-day study of PG, conducted in Sprague-Dawley rats, showed no adverse effects due to the enzyme up to dose levels of 2500 mg/kg-bw/day (NOAEL). Details of the study are presented, including, organ and body weights, histological findings, and blood and urine chemistry. Additionally, bacterial reverse mutation test (Ames test) and chromosomal aberration test using mammalian established cell line were conducted, resulting in the absence of mutagenicity in PG.

Chryseobacterium meningosepticum infection and cardiac tamponade in a long-term hemodialysis patient.

Chryseobacterium meningosepticum is a lactose-nonfermenting gram-negative bacilli ubiquitously found in the natural and hospital environment. Clinical infection caused by C. meningosepticum is very rare among healthy adults. We present the case of a patient with end-stage renal disease who developed purulent pericarditis with C. meningosepticum infection, which rapidly evolved into cardiac tamponade and death. To our knowledge, this is the first case in which C. meningosepticum caused fatal purulent pericarditis in a hemodialysis patient.

Chryseobacterium meningosepticum--an uncommon pathogen causing adult bacterial meningitis.

Chryseobacterium meningosepticum is an uncommon pathogen causing meningitis. We report a case of adult meningitis caused by chryseobacterium meningosepticum in an 88 year old woman. Immunosuppression due to old age, diabetes mellitus and history of hypertension of 20 years duration were the concomitant factors. chryseobacterium meningosepticum was isolated both from the cerebrospinal fluid and blood cultures. This organism was sensitive to quinolones, rifampicin and resistant to many antibiotics commonly used for empiric therapy for meningitis.