A propeptide toolbox for secretion optimization of Flavobacterium meningosepticum endopeptidase in Lactococcus lactis.

BACKGROUND: Lactic acid bacteria are a family of "generally regarded as safe" organisms traditionally used for food fermentation. In recent years, they have started to emerge as potential chassis for heterologous protein production. And more recently, due to their beneficial properties in the gut, they have been examined as potential candidates for mucosal delivery vectors, especially for acid-sensitive enzymes. One such application would be the delivery of gluten-digesting endopeptidases for the treatment of celiac disease. To facilitate these applications, an efficient recombinant protein expression toolbox is required, especially for recombinant protein secretion. While current tools for enhancing protein secretion consist mainly of signal peptides, secretion propeptides have also been observed to play a crucial role for protein secretion and improved yields. RESULTS: To expand the propeptide library for secretion optimization, we have mined and characterized three naturally occurring propeptides from the sequenced genomes of 109 Lactococcus species. These newly-mined propeptides were introduced after the N-terminal USP45 secretion signal to characterize and compare their effects on the secretion of Escherichia coli thioredoxin (TRX) and Flavobacterium meningosepticum prolyl endopeptidase (Fm PEP) in Lactococcus lactis NZ9000. All three propeptides, along with the positive control LEISSTCDA, improved volumetric secretion yields by 1.4-2.3-folds. However, enhancement of secretion yield is dependent on protein of interest. For TRX, the optimal combination of USP45 signal peptide and LEISSTCDA produced a 2.3-fold increase in secretion yields. Whilst for Fm PEP, propeptide 1 with USP45 signal peptide improved volumetric secretion yields by 2.2-fold compared to a 1.4-fold increase by LEISSTCDA. Similar trends in Fm PEP activity and protein yield also demonstrated minimal effect of the negative charged propeptides on PEP activity and thus folding. CONCLUSIONS: Overall, we have characterized three new propeptides for use in L. lactis secretion optimization. From success of these propeptides for improvement of secretion yields, we anticipate this collection to be valuable to heterologous protein secretion optimisation in lactic acid bacteria. We have also demonstrated for the first time, secretion of Fm PEP in L. lactis for potential use as a therapy agent in celiac disease.

Waterborne Elizabethkingia meningoseptica in Adult Critical Care.

Elizabethkingia meningoseptica is an infrequent colonizer of the respiratory tract; its pathogenicity is uncertain. In the context of a 22-month outbreak of E. meningoseptica acquisition affecting 30 patients in a London, UK, critical care unit (3% attack rate) we derived a measure of attributable morbidity and determined whether E. meningoseptica is an emerging nosocomial pathogen. We found monomicrobial E. meningoseptica acquisition (n = 13) to have an attributable morbidity rate of 54% (systemic inflammatory response syndrome ≥2, rising C-reactive protein, new radiographic changes), suggesting that E. meningoseptica is a pathogen. Epidemiologic and molecular evidence showed acquisition was water-source-associated in critical care but identified numerous other E. meningoseptica strains, indicating more widespread distribution than previously considered. Analysis of changes in gram-negative speciation rates across a wider London hospital network suggests this outbreak, and possibly other recently reported outbreaks, might reflect improved diagnostics and that E. meningoseptica thus is a pseudo-emerging pathogen.

Experience with Elizabethkingia meningoseptica Infection in Adult Patients at a Tertiary Hospital / 대한구급학회지

BACKGROUND: Few reports have documented the clinical characteristics and treatment outcomes of adult patients with Elizabethkingia meningoseptica infection. METHODS: Medical records of patients over 18 years of age and suspected of having an E. meningoseptica infection from March 1, 2006 to February 28, 2013 were reviewed retrospectively. Their clinical characteristics, antimicrobial susceptibility results, and treatment outcomes were analyzed. RESULTS: E. meningoseptica was isolated from 30 patients. Median age was 68.5 years, and infections were more frequent in males (17, 56.7%). The most common isolation source was sputum (23, 76.7%), and pneumonia was the most common condition (21, 70%) after excluding two cases of colonization. This bacterium was most susceptible to minocycline (27, 90%) and fluoroquinolones, including levofloxacin (20, 66.7%) and ciprofloxacin (18, 60%). The mortality rate due directly to E. meningoseptica infection was 20% (6/30), and uncontrolled pneumonia was the only cause of death. After isolating E. meningoseptica, the numbers of patients with pneumonia (9/9, 100% vs. 12/21, 57.1%), history of hemodialysis (5/9, 55.6% vs. 3/21, 14.3%), tracheostomy (8/9, 88.9 vs. 10/21, 47.6%), and median Charlson comorbidity index score (6 [range, 3-9] vs. 4 [range, 0-9]) were significantly higher in non-survivors than those in survivors (p < 0.05, for each). However, only 12 (40%) patients received appropriate antibiotics. CONCLUSIONS: E. meningoseptica infection most commonly presented as pneumonia in adults with severe underlying diseases. Despite the high mortality rate, the rate of appropriate antibiotic use was notably low.

Experience with Elizabethkingia meningoseptica Infection in Adult Patients at a Tertiary Hospital / 대한중환자의학회지

BACKGROUND: Few reports have documented the clinical characteristics and treatment outcomes of adult patients with Elizabethkingia meningoseptica infection. METHODS: Medical records of patients over 18 years of age and suspected of having an E. meningoseptica infection from March 1, 2006 to February 28, 2013 were reviewed retrospectively. Their clinical characteristics, antimicrobial susceptibility results, and treatment outcomes were analyzed. RESULTS: E. meningoseptica was isolated from 30 patients. Median age was 68.5 years, and infections were more frequent in males (17, 56.7%). The most common isolation source was sputum (23, 76.7%), and pneumonia was the most common condition (21, 70%) after excluding two cases of colonization. This bacterium was most susceptible to minocycline (27, 90%) and fluoroquinolones, including levofloxacin (20, 66.7%) and ciprofloxacin (18, 60%). The mortality rate due directly to E. meningoseptica infection was 20% (6/30), and uncontrolled pneumonia was the only cause of death. After isolating E. meningoseptica, the numbers of patients with pneumonia (9/9, 100% vs. 12/21, 57.1%), history of hemodialysis (5/9, 55.6% vs. 3/21, 14.3%), tracheostomy (8/9, 88.9 vs. 10/21, 47.6%), and median Charlson comorbidity index score (6 [range, 3-9] vs. 4 [range, 0-9]) were significantly higher in non-survivors than those in survivors (p < 0.05, for each). However, only 12 (40%) patients received appropriate antibiotics. CONCLUSIONS: E. meningoseptica infection most commonly presented as pneumonia in adults with severe underlying diseases. Despite the high mortality rate, the rate of appropriate antibiotic use was notably low.

Meningitis y choque séptico en un adulto mayor causados por Chryseobacterium meningosepticum (antes Flavobacterium meningosepticum) / Meningitis and septico shock in a greater adult caused by Chryseobacterium meningosepticum (before Flarobacterium meningosepticum)

Chrysobacterium meningosepticum es una bacteria ambiental que sobrevive en ambientes nosocomiales diversos y es capaz de producir infecciones en pacientes debilitados, colonizando inicialmente el tracto respiratorio. Esta bacteria muestra resistencia a muchos antimicrobianos, por lo que se vuelve difícil tratar una infección causada por este germen. Se describe la evolución de un cuadro infeccioso presentado por una paciente de 66 años, con insuficiencia cardíaca, hepatopatía e inmunocomprometida por tratamiento con prednisona para controlar la artritis reumatoidea que padecía. Cinco días antes del internamiento, la paciente presentó un cuadro de disnea progresiva y malestar general. Al momento del ingreso al hospital se mostraba afebril, hipotensa, con leucocitosis absoluta con desviación izquierda y alteración de función renal y hepática. Durante el segundo día fue necesario suministrar oxígeno suplementario y tratamiento para la insuficiencia cardíaca. Al tercer día de internamiento presentó fiebre, mayor disnea, delirio y taquicardia y se inició el tratamiento empírico con cefotaxime y amikacina. Los cultivos de orina y esputo tomados al momento de su ingreso fueron negativos por bacterias. Al cuarto día la paciente continuaba febril y con mayor deterioro del cuadro respiratorio y un grado de delirio importante. Se cambió el tratamiento a cefotaxime, ampicilina y vancomicina y se realizó punción lumbar. El líquido cefalorraquídeo presentó 31000 leucocitos/uL con 92 por ciento de polimofonucleares, proteínas elevadas y en la tinción de Gram del sedimento se encontró gran cantidad de bacilos Gram negativos. De un hemocultivo tomado previamente se aisló un bacilo Gram negativo. Al quinto dia, la paciente presentó choque séptico que complicó su estado general y provocó su fallecimiento. Los cultivos de sangre y de líquido cefalorraquídeo revelaron la presencia de C. meningosepticum. El caso se ajusta a las descripciones hechas en la literatura para C. menin...

Chrysobacterium meningosepticum is an environmental bacterium that can survive in different nosocomial environments and is able to produce infections in debilitated patients by initial colonization of the respiratory tract. This bacterium exhibits resistance to many antimicrobial agents what makes very difficult its eradication from an infectious process. Clinical evolution of an infectious disease caused by C. meningosepticum in a 66 years old immunocompromised patient is described. Five days before being hospitalized, the patient exhibited progressive dyspnea and malaise. When the patient was admitted into the hospital she was afebrile and hypotensive; blood tests showed leukocytosis with juvenile forms (left shift) and kidney and liver functions altered. Supplementary oxygen and treatment for cardiac insufficiency were provided during the second day. At the third day she exhibited fever, dyspnea and tachycardia. Empirical antimicrobial treatment with cefotaxime and amikacin was started. Bacteriological cultures of urine and sputum taken at the time the patient was admitted to the hospital were negative. During fourth day the patient continued with fever, the respiratory problem got worse and delirium was present. Antimicrobial treatment was changed to cefotaxime, ampicillin and vancomycin and a lumbar puncture was performed. The cerebrospinal fl uid (CSF) showed 31000 leukocytes/µL (92% polymorphonuclear leukocytes), elevated protein concentration and a high amount of Gram-negative bacilli in the sediment. A Gram-negative bacillus was also isolated from a blood culture previously taken. The fifth day of hospitalization, the patient entered in septic shock, the general condition got worse and she died. CSF and blood cultures were positive for C. meningosepticum...

A Case of Chryseobacterium (Flavobacterium) meningosepticum Peritonitis in a Patient on CAPD / 대한신장학회잡지

Peritonitis remains the leading cause of morbidity and technique failure for patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Chryseobacterium meningosepticum is the most common pathogen for humans among Chryseobacterium species and a few cases of CAPD peritonitis caused by C. meningosepticum were reported in the world. We experienced a case of CAPD peritonitis by C. meningosepticum in Ewha Womans University Hospital, Seoul, Korea. A 52-year-old diabetic woman on CAPD was admitted with turbid peritoneal fluid. She was suffered from three episodes of peritonitis. Effluent was cloudy with a cell count of 1,620 WBC/ mm3 (94% neutrophils, 4% lymphocytes). Effluent cultures obtained on 6th hospital day revealed a mixed growth of C. meningosepticum and P. aeruginosa. Tenckhoff catheter was removed due to persistent cloudy effluent till 9th hospital day. We herein report a case of peritonitis caused by C. meningosepticum and review the literature of similar cases of peritonitis.