RESUMEN
BACKGROUND: Healthcare-associated infections are the most frequent adverse events in healthcare worldwide, with limited available evidence suggesting highest burden in resource-limited settings. Recent Ebola epidemics emphasize the disastrous impact that spread of infectious agents within healthcare facilities can have, accentuating the need for improvement of infection control practices. Hand hygiene (HH) measures are considered to be the most effective tool to prevent healthcare-associated infections. However, HH knowledge and compliance are low, especially in vulnerable settings such as Guinea. The aim of PASQUALE (Partnership to Improve Patient Safety and Quality of Care) was to assess knowledge and compliance with HH and improve HH by incorporating the WHO HH Strategy within the Faranah Regional Hospital (FRH), Guinea. METHODS: In a participatory approach, a team of FRH staff and leadership was invited to identify priorities of the hospital prior to the start of PASQUALE. The local hygiene committee was empowered to increase its activities and take ownership of the HH improvement strategy. A baseline assessment of knowledge, perception and compliance was performed months before the intervention. The main intervention consisted of local alcohol-based-hand-rub (ABHR) production, with final product efficacy testing, in conjunction with a training adapted to the needs identified in the baseline assessment. A follow-up assessment was conducted directly after the training. Effectiveness of the intervention was assessed via uncontrolled before-and-after comparison. RESULTS: Baseline knowledge score (13.0/25) showed a significant increase to 19.0/25 in follow-up. Baseline-Compliance was 23.7% and increased significantly to 71.5% in follow-up. Compliance rose significantly across all professional groups except for midwifes and in all indications for HH, with the largest in the indication "Before aseptic tasks". The increase in compliance was associated with the intervention and remained significant after adjusting for confounders. The local pharmacy successfully supplies the entire hospital. The local supply resulted in a ten-fold increase of monthly hospital disinfectant consumption. CONCLUSION: The WHO HH strategy is an adaptable and effective method to improve HH knowledge and compliance in a resource-limited setting. Local production is a feasible method for providing self-sufficient supply of ABHR to regional hospitals like the FRH. Participatory approaches like hygiene committee ownership builds confidence of sustainability.
Asunto(s)
Infección Hospitalaria/prevención & control , Higiene de las Manos/organización & administración , Personal de Hospital/educación , Adhesión a Directriz/estadística & datos numéricos , Guinea , Conocimientos, Actitudes y Práctica en Salud , Humanos , Guías de Práctica Clínica como Asunto , Organización Mundial de la SaludRESUMEN
BACKGROUND: Rehabilitation clinics may vary widely in terms of type of care provided, duration of hospital stay, and case severity. Few data are available on prevalence of Clostridium difficile or extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E) colonization in rehabilitation clinics in Germany. AIM: This study investigated the frequency of intestinal colonization by these pathogens among patients in rehabilitation clinics of different specialization. METHODS: In the scope of a point prevalence study, faecal samples and demographic and clinical data were collected in five rehabilitation clinics. Samples were screened for C. difficile and ESBL-E by culture. Isolates were characterized by polymerase chain reaction for C. difficile toxins A and B, for ß-lactamase genes, and by molecular typing including pulsed-field gel electrophoresis and PCR-based ribotyping. FINDINGS: Of 305 patients screened, 11.1% were colonized by toxigenic C. difficile and 7.5% by ESBL-E. Colonization rates differed markedly between facilities, ranging from 1.6% to 26.3% for C. difficile and from zero to 23.7% for ESBL-E. Prevalence of colonization by C. difficile and ESBL-E was higher in neurological rehabilitation clinics than in clinics with other specialties (P<0.001). Molecular typing revealed six patients from one neurological rehabilitation clinic harbouring a unique C. difficile strain (ribotype 017). CTX-M-15 was the most prevalent ESBL type. We detected several indistinguishable pairs of ESBL-E isolates within some facilities. CONCLUSION: Significant differences were found in the prevalence of C. difficile and ESBL-E between rehabilitation clinics. Facilities providing specialized medical care for critically ill patients had higher prevalence rates. These results may help to delineate the requirements for infection prevention and control in rehabilitation clinics.
Asunto(s)
Portador Sano/epidemiología , Infecciones por Clostridium/epidemiología , Infecciones por Enterobacteriaceae/epidemiología , Enterobacteriaceae/enzimología , beta-Lactamasas/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Clostridioides difficile/clasificación , Clostridioides difficile/genética , Clostridioides difficile/aislamiento & purificación , Electroforesis en Gel de Campo Pulsado , Enterobacteriaceae/clasificación , Enterobacteriaceae/genética , Enterobacteriaceae/aislamiento & purificación , Heces/microbiología , Femenino , Alemania/epidemiología , Instituciones de Salud , Humanos , Masculino , Persona de Mediana Edad , Tipificación Molecular , Reacción en Cadena de la Polimerasa , Prevalencia , Factores de Riesgo , Adulto Joven , beta-Lactamasas/genéticaRESUMEN
After the first outbreak of Clostridium difficile PCR ribotype (RT) 027 in Germany in 2007, no further outbreaks were reported until the recent re-emergence of RT 027 in Hesse, a federal state with 6 million inhabitants located in south-west Germany. We undertook a survey to determine the prevalence of RT 027 and other strains in a prospective study. From January 2011 to July 2013, we analysed 291 specimens from patients diagnosed with C. difficile infection (CDI) in 40 healthcare facilities in Hesse. The mean incidence of CDI in hospitals including at least 10 patients in the survey was 9.9 per 10,000 patient days (range 4.8-22.8) in November 2012. We obtained 214 toxigenic C. difficile isolates. RT 001 was the most prevalent (31.8%). RT 027, the second most common type (26.6%), was prevalent in all hospitals (n=14) from which at least seven isolates were available for typing, but its frequency varied considerably (range: 9.170%). The annual frequency of RT 027 increased from 21.4% in 2011 to 30.0% in 2013 (p=0.04). Our study indicates that infections with C. difficile RT 027 are now prevalent in Hesse. It underscores the need for surveillance programmes to analyse the molecular epidemiology of C. difficile.
Asunto(s)
Clostridioides difficile/genética , Clostridioides difficile/aislamiento & purificación , Brotes de Enfermedades/estadística & datos numéricos , Enterocolitis Seudomembranosa/epidemiología , Ribotipificación , Clostridioides difficile/clasificación , Notificación de Enfermedades , Enterocolitis Seudomembranosa/diagnóstico , Enterocolitis Seudomembranosa/microbiología , Femenino , Alemania/epidemiología , Encuestas Epidemiológicas , Humanos , Incidencia , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Vigilancia de la Población , Prevalencia , Estudios ProspectivosRESUMEN
We investigated a cluster of shiga toxin-producing Escherichia coli (STEC) O104:H4 infections after a family party during a large STEC O104:H4 outbreak in Germany. To identify the vehicle we conducted a retrospective cohort study. Stool samples of party guests, and food and environmental samples from the catering company were tested for STEC. We defined cases as party guests with gastrointestinal symptoms and laboratory-confirmed STEC infection. We found 23 cases among 71 guests. By multivariable analysis consumption of salmon [odds ratio (OR) 15, 95% confidence interval (CI) 2.3-97], herb cream (OR 6.5, 95% CI 1.3-33) and bean salad (OR 6.1, 95% CI 1.4-26) were associated with STEC infection. STEC O104:H4 was detected in samples of bell pepper and salmon. The food handler developed STEC infection. Our results point towards transmission via several food items contaminated by a food handler. We recommend regular education of food handlers emphasizing their role in transmitting infectious diseases.
Asunto(s)
Brotes de Enfermedades , Infecciones por Escherichia coli/transmisión , Manipulación de Alimentos , Enfermedades Transmitidas por los Alimentos/microbiología , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Trazado de Contacto , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Heces/microbiología , Femenino , Enfermedades Transmitidas por los Alimentos/epidemiología , Alemania/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Encuestas y CuestionariosRESUMEN
German water guidelines do not recommend routine assessment of cold water for Legionella in healthcare facilities, except if the water temperature at distal sites exceeds 25°C. This study evaluates Legionella contamination in cold and warm water supplies of healthcare facilities in Hesse, Germany, and analyses the relationship between cold water temperature and Legionella contamination. Samples were collected from four facilities, with cases of healthcare-associated Legionnaires' disease or notable contamination of their water supply. Fifty-nine samples were from central lines and 625 from distal sites, comprising 316 cold and 309 warm water samples. Legionella was isolated from central lines in two facilities and from distal sites in four facilities. 17% of all central and 32% of all distal samples were contaminated. At distal sites, cold water samples were more frequently contaminated with Legionella (40% vs 23%, p <0.001) and with higher concentrations of Legionella (≥1,000 colony-forming unit/100 ml) (16% vs 6%, p<0.001) than warm water samples. There was no clear correlation between the cold water temperature at sampling time and the contamination rate. 35% of cold water samples under 20 °C at collection were contaminated. Our data highlight the importance of assessing the cold water supply of healthcare facilities for Legionella in the context of an intensified analysis.
Asunto(s)
Frío , Instituciones de Salud/normas , Legionella pneumophila/aislamiento & purificación , Microbiología del Agua/normas , Abastecimiento de Agua/normas , Humanos , Enfermedad de los Legionarios/prevención & control , Agua/normasRESUMEN
BACKGROUND AND OBJECTIVE: Clostridium difficile is a major cause of health care associated infections in industrialized countries. During the past decade, the incidence and clinical severity of C. difficile infections (CDI) have increased markedly. This increase has been associated with the emergence of a possibly highly virulent strain, the C. difficile PCR ribotype 027. We investigated the emergence of severe CDI and the associated PCR ribotypes in Hesse, Germany. PATIENTS AND METHODS: We conducted a retrospective analysis of clinical information and ribotyping results of all cases of severe CDI that were reported to the Hesse State Health Office or sent to our microbiologic diagnostic laboratory for detection and molecular typing of C. difficile in severe cases of CDI from 01/2008 to 12/2009. The data of a of 88 patients and 50 isolates were analysed. RESULTS: 89% of patients were at least 65 years old; the mean age was 77 years. The clinical outcome was known in 85 patients. 27% had died within 30 days of the diagnosis of CDI. Ribotyping results were available in 39 and 11 patients from 2008 and 2009, respectively. The isolates were assigned to nine different ribotypes. RT 027 and RT 001 were the most frequent ribotypes with 31 and 10 isolates, respectively. All other ribotypes were isolated once or twice. CONCLUSION: Our data indicate that C. difficile RT 027 and RT 001 are prevalent in Hesse and are often associated with severe or notifiable CDI. The high prevalence of RT 027 among the reported CDI cases does not indicate a generally high prevalence of the latter strain in Hesse, because detection of RT 027 was a case definition criterion, a fact that may cause a bias in the reported data. Further investigation would help to improve our understanding of the molecular epidemiology of severe CDI and to improve the prevention strategies.
Asunto(s)
Enterocolitis Seudomembranosa/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Clostridioides difficile/genética , Clostridioides difficile/patogenicidad , Estudios Transversales , Notificación de Enfermedades , Enterocolitis Seudomembranosa/microbiología , Enterocolitis Seudomembranosa/mortalidad , Femenino , Alemania , Humanos , Masculino , Persona de Mediana Edad , Vigilancia de la Población , Ribotipificación , Virulencia/genética , Adulto JovenRESUMEN
The photocatalytic activity of sulphonated cobalt phthalocyanine immobilized onto MCM-41 was investigated for decomposition of 2,4-dichlorophenol (2,4-DCP) in aqueous solutions. Immobilization of anion sulpho-cobalt phthalocyanine to the walls of MCM-41 was performed by pre-anchorage of 3-(aminopropyl)-triethoxysilane (APTES) onto MCM-41 via post-synthesis method. X-ray diffraction, nitrogen physisorption, diffuse reflectance spectroscopy, energy-dispersive X-ray and FT-IR methods were used to characterize the product. Photocatalytic efficiency of the prepared catalyst for degradation of 2,4-DCP was tested under illumination of UV-A and visible light. The results obtained reveal that the photocatalyst is very active in degradation of 2,4-DCP. The photodegradation process is completed within 3h using a dose of 0.6g/L of the catalyst under UV irradiation. The reactions follow a pseudo-first-order kinetics and the observed rate constant values change with 2,4-DCP concentrations. The reproducibility of the catalyst was tested. The reaction intermediates were identified by gas chromatoghraphy-mass spectrometry (GC-MS) technique.
Asunto(s)
Clorofenoles/química , Cobalto/química , Indoles/química , Fotoquímica/métodos , Dióxido de Silicio/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Catálisis , Clorofenoles/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Isoindoles , Cinética , Propilaminas , Silanos/química , Dióxido de Silicio/análisis , Espectroscopía Infrarroja por Transformada de Fourier , Factores de Tiempo , Rayos Ultravioleta , Contaminantes Químicos del Agua/química , Difracción de Rayos XRESUMEN
From January 2008 to April 2009, 72 cases of severe Clostridium difficile infection were reported from 18 different districts in the state of Hesse, Germany. A total of 41 C. difficile isolates from 41 patients were subjected to PCR ribotyping. PCR ribotype (RT) 027 was the most prevalent strain accounting for 24 of 41 (59%) of typed isolates, followed by RT 001 (eight isolates, 20%), RT 017 and 042 (two isolates each), and RT 003, 066, 078, 081, and RKI-034 (one isolate each). Eighteen patients had died within 30 days after admission. C. difficile was reported as underlying cause of or contributing to death in 14 patients, indicating a case fatality rate of 19%. The patients with lethal outcome attributable to C. difficile were 59-89 years-old (median 78 years). Ribotyping results were available for seven isolates associated with lethal outcome, which were identified as RT 027 in three and as RT 001 and 017 in two cases each. Our data suggest that C. difficile RT 027 is prevalent in some hospitals in Hesse and that, in addition to the possibly more virulent RT 027, other toxigenic C. difficile strains like RT 001 and 017 are associated with lethal C. difficile infections in this region.
Asunto(s)
Clostridioides difficile/clasificación , Enterocolitis Seudomembranosa/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Toxinas Bacterianas/análisis , Clostridioides difficile/aislamiento & purificación , Clostridioides difficile/patogenicidad , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Brotes de Enfermedades , Enterocolitis Seudomembranosa/mortalidad , Enterotoxinas/análisis , Heces/microbiología , Femenino , Alemania/epidemiología , Humanos , Incidencia , Masculino , Notificación Obligatoria , Megacolon Tóxico/microbiología , Megacolon Tóxico/mortalidad , Megacolon Tóxico/cirugía , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Vigilancia de la Población , Ribotipificación , VirulenciaRESUMEN
The use of titania-dispersed materials in photocatalytic processes has been proposed as an alternative to the conventional bare TiO(2), in order to modify the surface area and activity of the catalyst. A homogeneously dispersed Keggin unit into TiO(2) was synthesized using tungstophosphoric acid (TPA) and titanium tetraisopropoxide. This compound was then loaded into MCM-41 by dispersing it in a suspension containing the mesoporous phase. Two other titanium-containing MCM-41 catalysts, Ti-MCM-41 and TiO(2)/MCM-41 were also prepared using isomorphous substitution synthesis method and impregnation method, respectively, for the sake of comparison. The prepared photocatalysts were characterized by X-ray diffraction (XRD), nitrogen physisorption (BET) and chemical analysis. The catalysts were used to study degradation of methylene blue (MB) in aqueous solution. XRD result shows a pure anatase crystalline phase for TPA-containing TiO(2) indicating that there is good molecular distribution of tungstophosphoric acid into TiO(2) structure. Supported TPA-TiO(2) into MCM-41 shows both TPA-TiO(2) and MCM-41 characteristic X-ray reflections in the high-angle and low-angle parts of the XRD patterns, respectively. The experimental results show that adsorption is a major constituent in the elimination of MB from the dye solutions by the TPA-containing materials. Exploitation of both adsorption and photocatalytic processes speeds up the removal of the dye using the TPA-TiO(2)-loaded MCM-41 photocatalyst. The elimination of MB is completed within 15 min for a 30 mg l(-1) MB solution containing a catalyst dose of 100mg/100ml. The efficiencies of the other photocatalysts such as commercial TiO(2), Ti-MCM-41, TiO(2)/MCM-41 and TPA-TiO(2) for adsorption and degradation of MB were also studied and compared with that of the prepared catalyst.
Asunto(s)
Azul de Metileno/efectos de la radiación , Procesos Fotoquímicos , Adsorción , Catálisis , Ácidos Fosfóricos , Dióxido de Silicio , TitanioRESUMEN
A novel ion-selective PVC membrane sensor for Al(III) ions based on 6-(4-nitrophenyl)-2-phenyl-4-(thiophen-2-yl)-3,5-diaza-bicyclo[3.1.0]hex-2-ene (NTDH) as a new ionophore has been prepared and studied. The electrode exhibit a good response for aluminum ion over concentration range of 1.0x10(-6) to 1.0x10(-1) mol L(-1) with a Nernstian slope of 19.6+/-0.4 mV per decade and low detection limit of 6.3x10(-7) mol L(-1). The best performance was obtained with membrane composition 30% poly(vinyl chloride), 62% acetophenone, 5% oleic acid, 3% ionophore and 2 ml tetrahydrofuran. NTDH-based electrode was suitable for aqueous solutions of pH 3. It has relatively fast response time (approximately 10 s) and can be used at least for 3 months without any considerable divergence in potentials. The proposed membrane electrode revealed good selectivity for Al(III) ions over a wide variety of other cations. The standard electrode potentials were determined at different temperatures and used to calculate the isothermal coefficient of the electrode. The formation constant and stoichiometry ratio of ionophore-Al(III) complex were calculated at 25 degrees C by using segmented sandwich membrane method. It was used in non-aqueous solvents and also as indicator electrode in potentiometric determination of Al(III) ions in some real samples.
Asunto(s)
Aluminio/análisis , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Electrodos de Iones Selectos , Preparaciones Farmacéuticas/química , Hojas de la Planta/química , Té/química , Tiofenos/química , Agua/química , Aluminio/química , Calibración , Concentración de Iones de Hidrógeno , Membranas Artificiales , Potenciometría , Temperatura , Factores de TiempoRESUMEN
A new PVC membrane strontium ion-selective electrode has been constructed using 6-(4-nitrophenyl)-2-phenyl-4,4-dipropyl-3,5-diaza-bicyclo[3,1,0] hex-2-ene (NPDBH) as a neutral ionophore. The electrode was prepared with 7% NPDBH (as ionophore), 57% acetophenone (as plasticizer), 30% PVC and 6% oleic acid (as lipophilic additive). The electrode responds to Sr2+ ion with a sensitivity of 28.2+/-0.5 mV/decade over the range 1.0 x 10(-6)-1.0 x 10(-1) mol L(-1) and in a pH range of 3.0-10.0. The limit of detection was 2.4 x 10(-7) mol L(-1). It has a response time of <20s and can be used for at least three months without any divergence in potentials. The proposed electrode shows good discrimination of Sr2+ ion from several cations. The effect of organic solvents on electrode response was examined. The results show that this electrode can be used in ethanol media up to 15% (v/v) concentration without interference. The isothermal temperature coefficient of this electrode amounted to 0.00019 V/ degrees C. The electrode was found to work well under laboratory conditions. It was successfully applied to the determination of strontium ions in human urine and bone digests.
Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes/química , Electrodos de Iones Selectos , Ionóforos/química , Estroncio/análisis , Acetofenonas/química , Concentración de Iones de Hidrógeno , Ácido Oléico/química , Plastificantes/química , Cloruro de Polivinilo/química , Potenciometría , TemperaturaRESUMEN
Liquid polymer membrane electrodes based on nickel and manganese phthalocyanines were examined for use as anion-selective electrodes. The electrodes were prepared by incorporating the ionophores into plasticized poly(vinyl chloride) membranes, which were directly coated onto the surfaces of graphite electrodes. The resulting electrodes demonstrate near-Nernstian responses over a wide linear range of perchlorate anion (5 x 10(-7) to 1 x 10(-1) M). The electrodes have a fast response time, submicromolar detection limits (5 x 10(-7) M perchlorate), and could be used over a wide pH range of 3.5-10. The influences of lipophilic cationic and anionic additives on the response properties of the electrodes were investigated. The proposed sensors revealed high selectivity for perchlorate over a number of common inorganic and organic anions. The highest selectivity was observed for the electrode based on manganese phthalocyanine in the presence of the lipophilic anionic additive sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate. Application of the electrodes to determine perchlorate in tap water and human urine is also reported.
Asunto(s)
Indoles/química , Manganeso/química , Níquel/química , Compuestos Organometálicos/química , Cloruro de Polivinilo/química , Agua/análisis , Aniones , Boratos/química , Electrodos , Humanos , Concentración de Iones de Hidrógeno , Ionóforos , Isoindoles , Membranas Artificiales , Percloratos/química , Potenciometría/instrumentación , Potenciometría/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , UrinálisisRESUMEN
The antimicrobial susceptibilities of 338 clinical Streptococcus agalactiae isolates from two geographical regions in Germany were determined by agar dilution. All isolates were susceptible to penicillin, cefotaxime and vancomycin. The overall frequencies of erythromycin and clindamycin resistance were 11% and 4.7%, respectively. Determination of resistance phenotypes among the 37 erythromycin-resistant isolates revealed constitutive and inducible MLS(B) resistance in 40.6% and 37.8% of isolates, respectively, and susceptibility to clindamycin in 21.6% of isolates. Only 14.3% of isolates with inducible MLS(B) resistance were identified as clindamycin-resistant by determination of clindamycin MICs. Pulsed-field gel electrophoresis suggested a clonal distribution pattern among the erythromycin-resistant isolates.
Asunto(s)
Antibacterianos/farmacología , Clindamicina/farmacología , Farmacorresistencia Bacteriana , Eritromicina/farmacología , Streptococcus agalactiae/efectos de los fármacos , Dermatoglifia del ADN , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Femenino , Alemania , Humanos , Pruebas de Sensibilidad Microbiana , Epidemiología Molecular , Embarazo , Infecciones Estreptocócicas/microbiología , Streptococcus agalactiae/genética , Streptococcus agalactiae/aislamiento & purificaciónRESUMEN
A coated wire triamterene-selective electrode based on the incorporation of a triamterene-tetraphenylborate ion-pair in a poly(vinylchloride) coating membrane was constructed. The influence of membrane composition, temperature, pH of the test solution, and foreign ions on the electrode performance were investigated. The electrode showed a Nernstian response over a triamterene concentration range from 1.0 x 10(-6) to 3.5 x 10(-2) M, at 25 degrees C, and was found to be very selective, precise, and usable within the pH range 4.5-7.5. The standard electrode potentials, E degrees, were determined at 15, 20, 25, 30, 35, 40 and 45 degrees C and used to calculate the isothermal temperature coefficient (dE degrees /dt) of the electrode. Temperatures higher than 45 degrees C seriously affected the electrode performance. The electrode was successfully applied to the potentiometric determination of triamterene hydrochloride both in pure solutions and in pharmaceutical preparations.
Asunto(s)
Electrodos de Iones Selectos , Triantereno/análisis , Triantereno/química , Potenciometría/métodos , Triantereno/farmacocinéticaRESUMEN
Investigations of the population genetics of Bartonella henselae have demonstrated a high level of diversity among strains, and the delineation of isolates into one of two subtypes, type I (Houston) and type II (Marseille), represented by specific 16S ribosomal DNA (rDNA) sequences, has long been considered the most significant genotypic division within the species. This belief is challenged by recent work suggesting a role for horizontal gene exchange in generating intraspecies diversity. We attempted to resolve this issue and extend exploration of the population structure of B. henselae by using multilocus sequence typing (MLST) to examine the distribution of polymorphisms within nine different genes in a sample of 37 human and feline isolates. MLST distinguished seven sequence types (STs) that resolved into three distinct lineages, suggesting a clonal population structure for the species, and support for these divisions was obtained by macrorestriction analysis using pulsed-field gel electrophoresis. The distribution of STs among isolates recovered from human infections was not random, and such isolates were significantly more often associated with one particular ST, lending further support to the suggestion that specific genotypes contribute disproportionately to the disease burden in humans. All but one isolate lay on lineages that bore the representative strain of either the Houston or Marseille subtype. However, the distribution of the two 16S rDNA alleles among the isolates was not entirely congruent with their lineage allocations, indicating that this is not a sensitive marker of the clonal divisions within the species. The inheritances of several of the genes studied could not be reconciled with one another, providing further evidence of horizontal gene transfer among B. henselae strains and suggesting that recombination has a role in shaping the genetic character of bartonellae.
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Bartonella henselae/clasificación , Animales , Bartonella henselae/genética , Bartonella henselae/aislamiento & purificación , Secuencia de Bases , Enfermedad por Rasguño de Gato/microbiología , Gatos/microbiología , Cartilla de ADN , ADN Bacteriano/genética , ADN Ribosómico/genética , Variación Genética , Genotipo , Humanos , Filogenia , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo Genético/genética , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Mapeo Restrictivo/métodos , Serotipificación/métodosRESUMEN
Immune responses of the immunocompetent host to Bartonella henselae infection were investigated in the murine infection model using C57BL/6 mice. Following intraperitoneal infection with human-derived B. henselae strain Berlin-1, viable bacteria could be recovered from livers and spleens during the first week postinfection, while Bartonella DNA remained detectable by PCR in the liver for up to 12 weeks after infection. Granulomatous lesions developed in livers of infected mice, reached maximal density at 12 weeks after infection, and persisted for up to 20 weeks, indicating that B. henselae induced a chronic granulomatous hepatitis in the immunocompetent murine host. T-cell-mediated immune responses were analyzed in vitro by means of spleen cell proliferation and cytokine release assays as well as analysis of immunoglobulin G (IgG) isotypes. Spleen cells from infected mice proliferated specifically upon stimulation with heat-killed Bartonella antigen. Proliferative responses were mainly mediated by CD4+ T cells, increased during the course of infection, peaked at 8 weeks postinfection, and decreased thereafter. Gamma interferon, but not interleukin-4, was produced in vitro by spleen cells from infected animals upon stimulation with Bartonella antigens. Bartonella-specific IgG was detectable in serum of infected mice by 2 weeks, and the antibody concentration peaked at 12 weeks postinfection. IgG2b was the prominent isotype among the Bartonella-specific serum IgG antibodies. These data indicate that B. henselae induces cell-mediated immune responses with a Th1 phenotype in immunocompetent C57BL/6 mice.
Asunto(s)
Angiomatosis Bacilar/inmunología , Células TH1/inmunología , Angiomatosis Bacilar/microbiología , Angiomatosis Bacilar/patología , Animales , Especificidad de Anticuerpos , Bartonella henselae/genética , Bartonella henselae/inmunología , Linfocitos T CD4-Positivos/inmunología , División Celular , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Humanos , Inmunidad Celular , Inmunoglobulina G/biosíntesis , Isotipos de Inmunoglobulinas/inmunología , Inmunofenotipificación , Interferón gamma/biosíntesis , Cinética , Hígado/inmunología , Hígado/patología , Ratones , Ratones Endogámicos C57BL , Bazo/citología , Bazo/inmunología , Linfocitos T/citología , Linfocitos T/inmunologíaRESUMEN
The endothelium is a specific target for Bartonella henselae, and endothelial cell infection represents an important step in the pathogenesis of cat scratch disease and bacillary angiomatosis. Mechanisms of Bartonella-endothelial cell interaction as well as signaling pathways involved in target cell activation were analyzed. B. henselae strain Berlin-1, isolated from bacillary angiomatosis lesions of a human immunodeficiency virus-infected patient, potently stimulated human umbilical cord vein endothelial cells (HUVEC), as determined by NF-kappaB activation and enhanced adhesion molecule expression. These effects were accompanied by increased PMN rolling on and adhesion to infected endothelial cell monolayers, as measured in a parallel-plate flow chamber assay. Monoclonal antibodies against E-selectin significantly reduced PMN rolling and adhesion. In our hands, B. henselae Berlin-1 was substantially more active than the typing strain B. henselae ATCC 49882. E-selectin and ICAM-1 upregulation occurred for up to 9 days, as verified by Northern blotting and cell surface enzyme-linked immunosorbent assay. Induction of adhesion molecules was mediated via NF-kappaB activation and could be blocked by a specific NF-kappaB inhibitor. Additional studies indicated that B. henselae-induced effects did not require living bacteria or Bartonella lipopolysaccharides. Exposure of HUVEC to purified B. henselae outer membrane proteins (OMPs), however, reproduced all aspects of endothelial cell activation. In conclusion, B. henselae, the causative agent of cat scratch disease and bacillary angiomatosis, infects and activates endothelial cells. B. henselae OMPs are sufficient to induce NF-kappaB activation and adhesion molecule expression followed by enhanced rolling and adhesion of leukocytes. These observations identify important new properties of B. henselae, demonstrating its capacity to initiate a cascade of events culminating in a proinflammatory phenotype of infected endothelial cells.
Asunto(s)
Proteínas de la Membrana Bacteriana Externa/inmunología , Bartonella henselae/inmunología , Selectina E/genética , Molécula 1 de Adhesión Intercelular/genética , FN-kappa B/inmunología , Regulación hacia Arriba/inmunología , Animales , Adhesión Celular/inmunología , Movimiento Celular/inmunología , Endotelio Vascular/citología , Endotelio Vascular/inmunología , Expresión Génica , Humanos , Neutrófilos/inmunología , ConejosRESUMEN
Highly active antiretroviral therapy (HAART) suppresses the replication of human immunodeficiency virus (HIV) and leads to an increase in circulating CD4 T lymphocytes, but its effects on other immune compartments such as the intestinal mucosa are not well understood. We describe a severely immunodeficient HIV-infected patient with intractable watery diarrhea and weight loss caused by infection with Cryptosporidium parvum in whom we studied virologic and immunologic changes in both peripheral blood and the intestinal mucosa after initiating HAART. Mucosal biopsies were performed by rectoscopy before and at several time points after HAART was begun. Nucleic acids were extracted from rectal biopsy specimens and blood samples, and HIV RNA was measured by reverse-transcription polymerase chain reaction. Lymphocytes were isolated from rectal biopsy specimens after mechanical disaggregation, and circulating and mucosal CD4 T cells were determined by flow cytometry. HAART led to clinical recovery and eradication of cryptosporidiosis. In both blood and mucosa, HIV RNA decreased below the limit of detection and CD4 T cells increased. Mucosal CD4 T cells increased much faster and to much higher levels than circulating CD4 T cells. Our findings show a rapid repopulation of the intestinal mucosa with CD4 T cells after initiation of HAART that can effectively restore mucosal immunity, leading to eradication of opportunistic pathogens.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Terapia Antirretroviral Altamente Activa , Linfocitos T CD4-Positivos/patología , Criptosporidiosis/parasitología , Cryptosporidium/aislamiento & purificación , Mucosa Intestinal/patología , Intestinos/parasitología , Síndrome de Inmunodeficiencia Adquirida/sangre , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Síndrome de Inmunodeficiencia Adquirida/virología , Animales , Criptosporidiosis/complicaciones , Cryptosporidium/efectos de los fármacos , Humanos , Mucosa Intestinal/metabolismo , Masculino , Persona de Mediana Edad , ARN Viral/sangre , ARN Viral/metabolismo , Recto/patología , Recto/virología , Carga ViralRESUMEN
Nineteen Bartonella henselae strains and one Bartonella clarridgeiae strain were isolated from blood samples of 97 pet cats and 96 stray cats from Berlin, Germany, indicating prevalence rates of 1 and 18.7%, respectively, for B. henselae and 0 and 1%, respectively, for B. clarridgeiae. Eighteen of 19 B. henselae isolates corresponded to 16S rRNA type II. Pulsed-field gel electrophoresis (PFGE) analysis revealed seven different PFGE types among the feline B. henselae strains. Interestingly, all feline isolates displayed low genetic relatedness to B. henselae strain Berlin-1, which is pathogenic for humans.