Infecciones por Clostridioides difficile en pediatría. La visión del laboratorio a partir del diagnóstico microbiológico / Clostridioides difficile infections in pediatrics. The view of the laboratory based on microbiological diagnosis

La infección por Clostridioides difficile (ICD) es la principal responsable de diarreas nosocomiales en adultos. En los últimos años se registró un aumento en la incidencia de la ICD en la población adulta que, en cambio, no fue bien caracterizado en pediatría. El objetivo de este trabajo es analizar los datos resultantes del diagnóstico microbiológico de ICD en el Hospital de Pediatría "Prof. Dr. Juan P. Garrahan". Materiales y métodos: se realizó un estudio retrospectivo observacional descriptivo que abarcó desde el 01/01/2018 hasta el 31/12/2021. El diagnóstico se realizó mediante enzimoinmunoensayo para glutamato deshidrogenasa (GDH) y toxinas en materia fecal (MF). Cuando sólo se detectó GDH, se realizó un cultivo toxigénico (CT) de la MF para la detección de toxinas in vitro. Se registraron: edad, sexo y procedencia de los pacientes y recurrencias de las ICD. Se efectuaron estudios de sensibilidad de 387 cepas de C. difficile a metronidazol (MTZ) y vancomicina (VAN). Resultados: en 6632 muestras (1764 pacientes) se registraron 649 estudios positivos (9,8%) (139 pacientes), la mayoría correspondieron a pacientes internados en áreas no críticas. Edad promedio: 7 años (7 ± 4,7). Sexo: 55% masculino. Recurrencias: 62 (45%). Positivos detectados mediante CT: 43%. Sensibilidad antibiótica: 100% a MTZ y 99,7% a VAN. Conclusión: Nuestra población presenta un bajo porcentaje de positividad. Se destaca el rendimiento del CT que permitió el diagnóstico de más de un tercio de los casos. MTZ y VANCO tuvieron excelente actividad in vitro frente a C. difficile (AU)

Clostridioides difficile infection (CDI) is the main cause of nosocomial diarrhea in adults. In recent years there has been an increase in the incidence of CDI in the adult population; however, CDI has not been well characterized in pediatrics. The aim of this study was to analyze the data resulting from the microbiological diagnosis of CDI at Hospital de Pediatría Prof. Dr. Juan P. Garrahan. Materials and methods: a retrospective, observational and descriptive study was conducted from 01/01/2018 to 12/31/2021. Diagnosis was made using enzyme immunoassay for glutamate dehydrogenase (GDH) and toxins in stools. When only GDH was detected, toxigenic culture (TC) of stools was performed for in vitro toxin detection. The age, sex and origin of patients and CDI recurrences were recorded. Sensitivity studies of 387 strains of C. difficile to metronidazole (MTZ) and vancomycin (VAN) were performed. Results: In 6,632 samples (1,764 patients), 649 positive results (9.8%) were recorded (139 patients), most of which corresponded to patients hospitalized in noncritical areas. Mean age: 7 years (7 ± 4.7). Sex: 55% male. Recurrences: 62 (45%). TC-positive results: 43%. Antibiotic sensitivity: 100% to MTZ and 99.7% to VAN. Conclusion: A low percentage of positivity was found in our population. The performance of TC was outstanding, allowing for the diagnosis of more than one third of the cases. MTZ and VANCO had excellent in vitro activity against C. difficile (AU)

Infección por Clostridium difficile: descripción de las cepas NAP1/027 y de otros serotipos en un centro de alta complejidad de Cali, Colombia, 2012-2015 / Clostridium difficile infection: Description of NAP1/027 and non NAP1/027 strains in a high complexity center in Cali, Colombia, 2012-2015

Resumen Introducción. Clostridium difficile ocasiona infecciones hospitalarias que resultan en altas tasas de morbilidad y mortalidad. La cepa NAP1/027 se ha asociado con una mayor producción de toxinas y con una mayor gravedad, lo que aumenta la carga de la enfermedad. Objetivo. Describir la epidemiología de las infecciones asociadas con C. difficile y las características de la cepa NAP1/027. Materiales y métodos. Se hizo un estudio observacional basado en la revisión de las historias clínicas de los pacientes con muestras de heces positivas para C. difficile identificadas mediante la prueba Xpert™ entre el 2012 y el 2015 en un hospital de alta complejidad. La gravedad de la enfermedad se evaluó con el índice ATLAS. Resultados. Se incluyeron 42 casos de pacientes infectados, 9 de los cuales fueron positivos para la cepa NAP1/027. El uso de antibióticos antes de la infección durante más de siete días fue más frecuente en los casos de pacientes con muestras negativas para NAP1/027. En la mitad de los pacientes, la duración de la diarrea fue mayor de cinco días y no hubo diferencias según el tipo de cepa (p>0,05). Los casos de pacientes positivos para la cepa NAP1/027 se caracterizaron por presentar deposiciones fétidas y sanguinolentas. La gravedad de la infección fue similar entre los grupos. Conclusión. Se comprobó la circulación de la cepa NAP1/027, pero su presencia no supuso diferencias clínicas significativas con respecto a otras cepas, lo cual podría deberse al limitado número de pacientes en este estudio. Sin embargo, su presencia debe alertar a los médicos y a las instituciones de salud, dada su frecuente asociación con la gravedad de la infección y la mortalidad.

Abstract Introduction: Clostridium difficile causes nosocomial infections leading to high morbidity and mortality. The NAP1/027 strain is associated with a higher toxin production and disease severity, which increases the load of the disease. Objective: To describe the epidemiology of the infections associated with C. difficile and the characteristics related to the NAP1/027 strain. Materials and methods: This was an observational study based on the revision of clinical registries of patients with fecal samples that were positive for C. difficile identified by the Xpert test™ between 2012 and 2015 in a high complexity institution. The severity of the disease was evaluated by means of the ATLAS score. Results: We included 42 infected cases, 9 of which were positive for the NAP1/027strain. The use of antibiotics previous to the infection for more than seven days was more frequent in patients with negative results for NAP1/027. The duration of diarrhea in half of the patients was longer than five days and there were no differences according to the type of strain (p>0.05). Positive cases for the NAP1/027 strain were characterized by presenting fetid and bloody stools. The severity of the infection was similar between the groups. Conclusions: In Colombia, the NAP1/027 strain circulates without significant clinical differences, which could be due to the limited number of patients. Nevertheless, the existence of NAP1/027 should alert physicians and health institutions because of its high association with severity and mortality.

Adhesion and invasion of Clostridium perfringens type A into epithelial cells

ABSTRACT Clostridium perfringens is the causative agent for necrotic enteritis. It secretes the major virulence factors, and α- and NetB-toxins that are responsible for intestinal lesions. The TpeL toxin affects cell morphology by producing myonecrosis, but its role in the pathogenesis of necrotic enteritis is unclear. In this study, the presence of netB and tpeL genes in C. perfringens type A strains isolated from chickens with necrotic enteritis, their cytotoxic effects and role in adhesion and invasion of epithelial cells were evaluated. Six (27.3%) of the 22 C. perfringens type A strains were harboring the tpeL gene and produced morphological alterations in Vero cells after 6 h of incubation. Strains tpeL (-) induced strong cell rounding after 6 h of incubation and produced cell enlargement. None of the 22 strains harbored netB gene. All the six tpeL (+) gene strains were able to adhere to HEp-2 cells; however, only four of them (66.6%) were invasive. Thus, these results suggest that the presence of tpeL gene or TpeL toxin might be required for the adherence of bacteria to HEp-2 cells; however, it could not have any role in the invasion process.

Características de la infección por Clostridium difficile en una institución de alta complejidad y reporte de la circulación en Colombia de la cepa hipervirulenta NAP1/027 / Characteristics of Clostridium difficile infection in a high complexity hospital and report of the circulation of the NAP1/027 hypervirulent strain in Colombia

Resumen Introducción. Clostridium difficile es el principal responsable de la diarrea asociada al uso de antibióticos. En Colombia y en Latinoamérica, el conocimiento sobre el comportamiento epidemiológico de la infección por C. difficile todavía es limitado. Objetivo. Describir las características de una serie de pacientes con infección por C.difficile . Materiales y métodos. Se hizo un estudio descriptivo de una serie de casos de pacientes con infección por C. difficile atendidos en la Fundación Clínica Shaio, entre enero de 2012 y noviembre de 2015. Resultados. Se estudiaron 36 pacientes con una edad promedio de 65 años. Se determinaron los siguientes factores relacionados con la infección por C. difficile: uso previo de antimicrobianos (94,4 %), hospitalización en los últimos tres meses (66,7 %) y uso de inhibidores de la bomba de protones (50 %). Las comorbilidades más comunes fueron la enfermedad renal crónica (41,7 %) y la diabetes mellitus (30,6 %). Los síntomas más frecuentes fueron más de tres deposiciones diarreicas (97,1 %) y dolor abdominal (42,9 %). En cuanto a la gravedad de los casos, 44,4 % se clasificó como leve a moderado, 38,9 % como grave, y 11,1 % como complicado o grave. El método de diagnóstico más utilizado (63,8% de los pacientes) fue la identificación de la toxina mediante reacción en cadena de la polimerasa (PCR). La mortalidad global durante la hospitalización fue de 8 %. Se identificaron cuatro cepas del serotipo NAP1/027 y nueve muestras fueron positivas para la toxina binaria. Conclusión. La infección por C. difficile debe sospecharse en pacientes con deposiciones diarreicas y factores asociados tradicionalmente a esta enfermedad. Se reportó la circulación de cepas hipervirulentas del serotipo NAP1/027 en Colombia, lo cual debe enfrentarse con la vigilancia epidemiológica y el diagnóstico temprano.

Abstract Introduction: Clostridium difficile is the main pathogen related to healthcare-associated diarrhea and it is the cause of 20 to 30% of diarrhea cases caused by antibiotics. In Colombia and Latin America, the knowledge about the epidemiological behavior of this infection is limited. Objective: To describe the characteristics of a series of patients with C. difficile infection. Materials and methods: We performed a descriptive case series study of patients with C. difficile infection hospitalized in the Fundación Clínica Shaio from January, 2012, to November, 2015. Results: We analyzed 36 patients. The average age was 65 years. The risk factors associated with the infection were: previous use of antibiotics (94.4%), prior hospitalization in the last three months (66.7%) and use of proton pump inhibitors (50%). The most common comorbidities were chronic kidney disease (41.7%) and diabetes mellitus (30.6%). The most frequent symptoms were more than three loose stools per day (97.1%) and abdominal pain (42.9%). According to the severity of the disease, 44.4% of cases were classified as mild to moderate, 38.9% as severe, and 11.1% as complicated or severe. The detection of the toxin by PCR (GeneXpert) was the most common diagnostic procedure (63.8%). Global mortality during hospitalization was 8%. We identified four strains with serotype NAP1/027 and nine samples positive for binary toxin. Conclusion: Clostridium difficile infection should be suspected in patients with diarrhea and traditional risk factors associated with this disease. We report the circulation of the hypervirulent strain serotype NAP1/027 in Colombia, which should be countered with epidemiological surveillance and a prompt diagnosis.

Detection of vancomycin-resistant enterococci (VRE) in stool specimens submitted for Clostridium difficile toxin testing

Abstract The aim of this study was to determine the association between Clostridium difficile (C. difficile) and vancomycin-resistant Enterococcus (VRE) and efficacy of screening stools submitted for C. difficile toxin assay for prevalence of VRE. Between April 2012 and February 2014, 158 stool samples submitted for C. difficile toxin to the Marmara University Microbiology Laboratory, were included in the study. Stool samples were analyzed by enzyme immuno assay test; VIDAS (bioMerieux, France) for Toxin A&B. Samples were inoculated on chromID VRE (bioMerieux, France) and incubated 24 h at 37 °C. Manuel tests and API20 STREP (bioMerieux, France) test were used to identify the Enterococci species. After the species identification, vancomycin and teicoplanin MIC's were performed by E test and molecular resistance genes for vanA vs vanB were detected by polymerase chain reaction (PCR). Of the 158 stool samples, 88 were toxin positive. The prevalence of VRE was 17%(n:19) in toxin positives however, 11.4% in toxin negatives(n:70). All VRE isolates were identified as Enterococcus faecium. These results were evaluated according to Fischer's exact chi-square test and p value between VRE colonization and C. difficile toxin positivity was detected 0.047 (p < 0.05). PPV and NPV were 79% and 47% respectively. In our study, the presence of VRE in C. difficile toxin positives is statistically significant compared with toxin negatives (p < 0.05). Screening for VRE is both additional cost and work load for the laboratories. Therefore VRE screening among C. difficile toxin positive samples, will be cost effective for determination of high risk patients in the hospitals especially for developing countries.

Analysis of risk factors and clinical manifestations associated with Clostridium difficile disease in Serbian hospitalized patients

Abstract Clostridium difficile is the leading cause of infectious diarrhoea in hospitalized patients. The aim of this study was to determine the risk factors important for the development of hospital-acquired Clostridium difficile-associated disease and clinical manifestations of Clostridium difficile-associated disease. The clinical trial group included 37 hospitalized patients who were selected according to the inclusion criteria. A control group of 74 hospitalized patients was individually matched with cases based on hospital, age (within 4 years), sex and month of admission.Clostridium difficile-associated disease most commonly manifested as diarrhoea (56.76%) and colitis (32%), while in 8.11% of patients, it was diagnosed as pseudomembranous colitis, and in one patient, it was diagnosed as fulminant colitis. Statistically significant associations (p < 0.05) were found with the presence of chronic renal failure, chronic obstructive pulmonary disease, cerebrovascular accident (stroke) and haemodialysis. In this study, it was confirmed that all the groups of antibiotics, except for tetracycline and trimethoprim-sulfamethoxazole, were statistically significant risk factors for Clostridium difficile-associated disease (p < 0.05). However, it was difficult to determine the individual role of antibiotics in the development of Clostridium difficile-associated disease. Univariate logistic regression also found that applying antibiotic therapy, the duration of antibiotic therapy, administration of two or more antibiotics to treat infections, administering laxatives and the total number of days spent in the hospital significantly affected the onset of Clostridium difficile-associated disease (p < 0.05), and associations were confirmed using the multivariate model for the application of antibiotic therapy (p = 0.001), duration of antibiotic treatment (p = 0.01), use of laxatives (p = 0.01) and total number of days spent in the hospital (p = 0.001). In this study of patients with hospital-acquired diarrhoea, several risk factors for the development of Clostridium difficile-associated disease were identified.

Antimicrobial susceptibility of Brazilian Clostridium difficile strains determined by agar dilution and disk diffusion

Abstract Clostridium difficile is a leading cause of diarrhea in hospitalized patients worldwide. While metronidazole and vancomycin are the most prescribed antibiotics for the treatment of this infection, teicoplanin, tigecycline and nitazoxanide are alternatives drugs. Knowledge on the antibiotic susceptibility profiles is a basic step to differentiate recurrence from treatment failure due to antimicrobial resistance. Because C. difficile antimicrobial susceptibility is largely unknown in Brazil, we aimed to determine the profile of C. difficile strains cultivated from stool samples of inpatients with diarrhea and a positive toxin A/B test using both agar dilution and disk diffusion methods. All 50 strains tested were sensitive to metronidazole according to CLSI and EUCAST breakpoints with an MIC90 value of 2 μg/mL. Nitazoxanide and tigecycline were highly active in vitro against these strains with an MIC90 value of 0.125 μg/mL for both antimicrobials. The MIC90 were 4 μg/mL and 2 μg/mL for vancomycin and teicoplanin, respectively. A resistance rate of 8% was observed for moxifloxacin. Disk diffusion can be used as an alternative to screen for moxifloxacin resistance, nitazoxanide, tigecycline and metronidazole susceptibility, but it cannot be used for testing glycopeptides. Our results suggest that C. difficile strains from São Paulo city, Brazil, are susceptible to metronidazole and have low MIC90 values for most of the current therapeutic options available in Brazil.

Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry for identification of Clostridium species isolated from Saudi Arabia

Abstract The aim of this study was to identify different Clostridium spp. isolated from currency notes from the Ha’il region of Saudi Arabia in September 2014 using MALDI–TOF-MS. Clostridium spp. were identified by Bruker MALDI–TOF-MS and compared with VITEK 2. The confirmation of the presence of different Clostridium spp. was performed by determining the sequence of the 16S ribosomal RNA gene. In this study, 144 Clostridium spp. were isolated. Among these specimens, MALDI–TOF-MS could identify 88.8% (128/144) of the isolates to the species level and 92.3% (133/144) to the genus level, whereas, VITEK 2 identified 77.7% of the (112/144) isolates. The correct identification of the 144 isolates was performed by sequence analysis of the 500 bp 16S rRNA gene. The most common Clostridium spp. identified were Clostridium perfringens (67.36%), Clostridium subterminale (14.58%), Clostridium sordellii (9%) and Clostridium sporogenes (9%). The results of this study demonstrate that MALDI–TOF-MS is a rapid, accurate and user friendly technique for the identification of Clostridium spp. Additionally, MALDI–TOF-MS has advantages over VITEK 2 in the identification of fastidious micro-organisms, such as Clostridium spp. Incorporating this technique into routine microbiology would lead to more successful and rapid identification of pathogenic and difficult to identify micro-organisms.

Isolation of recombinant antibodies directed against surface proteins of Clostridium difficile

Abstract Clostridium difficile has emerged as an increasingly important nosocomial pathogen and the prime causative agent of antibiotic-associated diarrhoea and pseudomembranous colitis in humans. In addition to toxins A and B, immunological studies using antisera from patients infected with C. difficile have shown that a number of other bacterial factors contribute to the pathogenesis, including surface proteins, which are responsible for adhesion, motility and other interactions with the human host. In this study, various clostridial targets, including FliC, FliD and cell wall protein 66, were expressed and purified. Phage antibody display yielded a large panel of specific recombinant antibodies, which were expressed, purified and characterised. Reactions of the recombinant antibodies with their targets were detected by enzyme-linked immunosorbent assay; and Western blotting suggested that linear rather than conformational epitopes were recognised. Binding of the recombinant antibodies to surface-layer proteins and their components showed strain specificity, with good recognition of proteins from C. difficile 630. However, no reaction was observed for strain R20291—a representative of the 027 ribotype. Binding of the recombinant antibodies to C. difficile M120 extracts indicated that a component of a surface-layer protein of this strain might possess immunoglobulin-binding activities. The recombinant antibodies against FliC and FliD proteins were able to inhibit bacterial motility.

Clostridium difficile outbreak caused by NAP1/BI/027 strain and non-027 strains in a Mexican hospital

Abstract Background Clostridium difficile infections caused by the NAP1/B1/027 strain are more severe, difficult to treat, and frequently associated with relapses. Methods A case–control study was designed to examine a C. difficileinfection (CDI) outbreak over a 12-month period in a Mexican hospital. The diagnosis of toxigenic CDI was confirmed by real-time polymerase chain reaction, PCR (Cepheid Xpert C. difficile/Epi). Results During the study period, 288 adult patients were evaluated and 79 (27.4%) patients had confirmed CDI (PCR positive). C. difficilestrain NAP1/B1/027 was identified in 31 (39%) of the patients with confirmed CDI (240 controls were included). Significant risk factors for CDI included any underlying disease (p < 0.001), prior hospitalization (p < 0.001), and antibiotic (p < 0.050) or steroid (p < 0.001) use. Laboratory abnormalities included leukocytosis (p < 0.001) and low serum albumin levels (p < 0.002). Attributable mortality was 5%. Relapses occurred in 10% of patients. Risk factors for C. difficileNAP1/B1/027 strain infections included prior use of quinolones (p < 0.03). Risk factors for CDI caused by non-027 strains included chronic cardiac disease (p < 0.05), chronic renal disease (p < 0.009), and elevated serum creatinine levels (p < 0.003). Deaths and relapses were most frequent in the 027 group (10% and 19%, respectively). Conclusions C. difficile NAP1/BI/027 strain and non-027 strains are established pathogens in our hospital. Accordingly, surveillance ofC. difficile infections is now part of our nosocomial prevention program.

High occurrence of Fusobacterium nucleatum and Clostridium difficile in the intestinal microbiota of colorectal carcinoma patients

Abstract Colorectal carcinoma is considered the fourth leading cause of cancer deaths worldwide. Several microorganisms have been associated with carcinogenesis, including Enterococcus spp., Helicobacter pylori, enterotoxigenic Bacteroides fragilis, pathogenic E. coli strains and oral Fusobacterium. Here we qualitatively and quantitatively evaluated the presence of oral and intestinal microorganisms in the fecal microbiota of colorectal cancer patients and healthy controls. Seventeen patients (between 49 and 70 years-old) visiting the Cancer Institute of the Sao Paulo State were selected, 7 of whom were diagnosed with colorectal carcinoma. Bacterial detection was performed by qRT-PCR. Although all of the tested bacteria were detected in the majority of the fecal samples, quantitative differences between the Cancer Group and healthy controls were detected only for F. nucleatum and C. difficile. The three tested oral microorganisms were frequently observed, suggesting a need for furthers studies into a potential role for these bacteria during colorectal carcinoma pathogenesis. Despite the small number of patients included in this study, we were able to detect significantly more F. nucleatum and C. difficile in the Cancer Group patients compared to healthy controls, suggesting a possible role of these bacteria in colon carcinogenesis. This finding should be considered when screening for colorectal cancer.

Descripción clínica y epidemiológica de la infección por Clostridium difficile en población pediátrica / Clinic and epidemiologic description of Clostridium difficile infection in a pediatric population

Background: Clostridium difficile (CUj-associated disease (CDAD) and the role of the hypervirulent strain NAP1 have not been well characterized in Pediatrics. Aims: To describe clinical features of CDAD, and to estimate NAP1 frequency and association with disease severity in Pediatrics. Methods: Descriptive, transversal surveillance of diarrheal episodes in Chilean children, hospitalized between February 2012 and December 2013, positive for CD by molecular diagnosis. Results: A total of 66 episodes of diarrhea with identification of CD occurred thougout the study period in children between 1 month and 19 years of age of which 39% were younger than one year old. CD acquisition was predominantly nosocomial and the most common risk factors were: presence of comorbidities (98.6%), use of antibiotics (93.9%), proton pump inhibitors (84.8%), invasive mechanic ventilation (54.5%), feeding tube (48.5%) and immunosuppression (40.9%). Clinical course was mostly mild, but 12 cases presented an unfavorable course, of which 3/26 occurred in children less than one year. Only one case was positive for NAP1 and had a mild course. Conclusion: Diarrhea with identification of CD was present throughout all pediatric ages, including children less than one year old. Analytical and longitudinal studies are required to better characterize the pathogenic role of CD in this age group. CDAD occurred mostly in patients with risk factors, and the clinical course was predominantly mild.

Introducción: Aún no ha sido bien caracterizada la infección por Clostridium difficile ni el rol de la cepa hipervirulenta NAP1 en pediatría. Objetivos: Describir las características clínicas de la infección por C. difficile, la frecuencia de NAP1 y su asociación con gravedad en población pediátrica. Material y Método: Estudio transversal, descriptivo, de episodios de diarrea con identificación molecular de C. difficile en niños chilenos hospitalizados entre febrero de 2012 y diciembre de 2013. Resultados: Se estudiaron 66 episodios de diarrea por C. difficile, en niños entre 1 mes y 19 años, teniendo 39% menos de un año de edad. La adquisición fue predominantemente nosocomial. Los factores de riesgo más frecuentes fueron: co-morbilidades, uso de antimicrobianos, inhibidores de bomba de protones, ventilación mecánica invasora, sonda de alimentación e inmunosupresión. El curso clínico fue mayoritariamente benigno, con 12 casos de evolución desfavorable incluyendo lactantes bajo un año de edad. Un niño presentó la cepa NAP1, con un curso clínico leve. Discusión: En esta serie, la diarrea con identificación de C. difficile se presentó en niños de todas las edades, incluyendo aquellos bajo un año. Se necesitan estudios analíticos y longitudinales para determinar el rol patógeno en este último grupo etario. La infección afecta a niños con factores de riesgo y es de evolución predominantemente satisfactoria.

Esporas de Clostridium difficile y su relevancia en la persistencia y transmisión de la infección / Clostridium difficile spores and its relevance in the persistence and transmission of the infection

C. difficile is an anaerobic spore former pathogen and the most important etiologic agent of nosocomial and community acquired antibiotics associated diarrheas. C. difficile infections (CDI) are responsible for an elevated rate of morbidity in developed and developing countries. Although the major virulence factors responsible for clinical symptoms of CDI are the two toxins TcdA and TcdB, C. difficile spores are the main vehicle of infection, persistence and transmission of CDI. Recent work has unrevealed unique properties of C. difficile spores that make them remarkable morphotypes of persistence and transmission in the host, including their resistance to antibiotics, the host immune response and disinfectants. The present review summarizes relevant aspects of C. difficile spore biology that have major implications from a clinical and medical perspective.

Clostridium difficile es un patógeno anaerobio, formador de esporas y el agente etiológico más importante de las diarreas asociadas a antimicrobianos, tanto nosocomiales como adquiridas en la comunidad. Las infecciones asociadas a C. difficile poseen una elevada tasa de morbilidad en países desarrollados y en vías de desarrollo. Los dos factores de virulencia principales son TcdA y TcdB, toxinas que causan la remodelación del citoesqueleto lo cual desencadena los síntomas clínicos asociados a esta enfermedad infecciosa. A pesar que las esporas de C. difficile son el principal vehículo de infección, persistencia en el hospedero y de transmisión, pocos estudios se han enfocado sobre este clave aspecto. Es altamente probable que la espora juegue roles esenciales en los episodios de recurrencia y de transmisión horizontal de la infección por este microorganismo. Estudios recientes han revelado características únicas de las esporas de C. difficile que las hacen capaces de ser altamente transmisibles y persistir dentro del hospedero. Más aún, algunas de estas propiedades están relacionadas con la resistencia de sus esporas a los desinfectantes más comúnmente usados en los recintos hospitalarios. La presente revisión resume los conocimientos más relevantes en la biología de las esporas de C. difficile, con un énfasis en aquellos aspectos con implicancias clínicas, incluido el control de infecciones en el ambiente hospitalario.

Infecção pelo Clostridium difficile / Clostridium difficile infection

Embora descrita também na comunidade, a doença causada pelo C. difficile (DCd) é na atualidade uma importante causa de diarreia associada aos cuidados de saúde, principalmente nos hospitais, respondendo por 15% a 25% dos casos de diarreia associada ao uso de antibióticos. Seu conhecimento vem despertando muito interesse na atualidade, não só pelo aumento da frequência no mundo inteiro, mas também pelo aumento da gravidade, principalmente após a caracterização da cepa hipervirulenta BI/NAP1/027 em vários países...

Although it has been described in community, the disease caused by C. difficile (DCd) is an important cause of diarrhea related to health care actually, mainly at the hospitals, responding to 15% to 25% of diarrhea causes related to antibiotic use. Its discovery has been evoking a lot of interest nowadays not just about the increase frequency all over the world, but for increase gravity as well, principally after hypervirulent strain BI/NAP1/027 characterizaction in many countries...

Acute myonecrosis in horse caused by Clostridium novyi type A

The objective of this study was to describe the first report involving a case of equine acute myonecrosis caused by C. novyi type A with an emphasis on clinical signs, the pathological and bacteriological analysis, and molecular identification of the microorganisms as the key of the definitive diagnosis.

Comparison of Supplemented Brucella Agar and Modified Clostridium difficile Agar for Antimicrobial Susceptibility Testing of Clostridium difficile

BACKGROUND: Antimicrobial susceptibility testing (AST) of Clostridium difficile is increasingly important because of the rise in resistant strains. The standard medium for the AST of C. difficile is supplemented Brucella agar (sBA), but we found that the growth of C. difficile on sBA was not optimal. Because active growth is critical for reliable AST, we developed a new, modified C. difficile (mCD) agar. C. difficile grew better on mCD agar than on sBA. METHODS: C. difficile isolates were collected from patients with healthcare-associated diarrhea. sBA medium was prepared according to the CLSI guidelines. Homemade mCD agar containing taurocholate, L-cysteine hydrochloride, and 7% horse blood was used. For 171 C. difficile isolates, we compared the agar dilution AST results from mCD agar with those from sBA. RESULTS: No significant differences were observed in the 50% minimal inhibitory concentration (MIC50) and 90% minimal inhibitory concentration (MIC90) of clindamycin (CLI), metronidazole (MTZ), moxifloxacin (MXF), piperacillin-tazobactam (PTZ), and rifaximin (RIX), but the values for vancomycin (VAN) were two-fold higher on mCD agar than on sBA. The MICs of CLI, MXF, and RIX were in 100% agreement within two-fold dilutions, but for MTZ, VAN, and PTZ, 13.7%, 0.6%, and 3.1% of the isolates, respectively, were outside the acceptable range. CONCLUSIONS: The MIC ranges, MIC50 and MIC90, were acceptable when AST was performed on mCD agar. Thus, mCD agar could be used as a substitute medium for the AST of C. difficile.

Equine hyperimmune serum protects mice against Clostridium difficile spore challenge

Clostridium (C.) difficile is a common cause of nosocomial diarrhea in horses. Vancomycin and metronidazole have been used as standard treatments but are only moderately effective, which highlights the need for a novel alternative therapy. In the current study, we prepared antiserum of equine origin against both C. difficile toxins A and B as well as whole-cell bacteria. The toxin-neutralizing activities of the antibodies were evaluated in vitro and the prophylactic effects of in vivo passive immunotherapy were demonstrated using a conventional mouse model. The data demonstrated that immunized horses generated antibodies against both toxins A and B that possessed toxin-neutralizing activity. Additionally, mice treated with the antiserum lost less weight without any sign of illness and regained weight back to a normal range more rapidly compared to the control group when challenged orally with 10(7) C. difficile spores 1 day after serum injection. These results indicate that intravenous delivery of hyperimmune serum can protect animals from C. difficile challenge in a dose-dependent manner. Hence, immunotherapy may be a promising prophylactic strategy for preventing C. difficile infection in horses.

Clinical risk factors for Clostridium difficile-associated diseases

Many factors appear to influence the chance of acquiring Clostridium difficile (C. difficile) infection, and an accurate identification of risk factors could be beneficial in many ways. Thus, in the present study, clinical risk factors for C. difficile-associated disease (CDAD) in Korea were identified. A total of 93 patients who met the inclusion criteria and 186 age/gender/ward/admission period-matched control patients were included in this study. Statistically significant associations were found with presence of chronic lung diseases (odds ratio [OR], 3.41; 95% confidence interval [CI], 1.25-9.32; p = 0.017), presence of ileus (OR, 10.05; 95% CI, 2.42-41.80; p = 0.001), presence of intensive care unit (ICU) stay (OR, 9.79; 95% CI, 3.03-31.68; p < 0.001), use of cephalosphorins (OR, 3.30; 95% CI, 1.13-9.62; p = 0.029), history of surgery (OR, 10.89; 95% CI, 3.96-29.92; p < 0.001), and history of long-term care facility stay (OR, 14.90; 95% CI, 4.02-55.26; p < 0.001). Awareness of CDAD is critical to provide appropriate clinical care. Surveillance of the national incidence rate and multicenter studies are needed, and the potential value of a C. difficile vaccine should be studied.

Recent changes in Clostridium difficile infection / Recentes mudanças da infecção por Clostridium difficile

Clostridium difficile is the main cause of nosocomial diarrhea. Diarrhea associated with C. difficile has increased incidence, morbidity, and mortality in the last few years. The major related risk factors include use of antibiotics, elderly patients and prolonged hospital stay. Many patients receive combinations of antibiotics or multiple antibiotics, which represents the main risk to develop diarrhea associated to C. difficile or its recurrence. Therefore, interventions to improve antibiotic prescribing, as well as compliance with infection control measures can reduce hospital-acquired C. difficile infections. This review addresses the epidemiological changes in C. difficile disease and its treatment.

Clostridium difficile é a principal causa de diarreia hospitalar. A diarreia por C. difficile aumentou sua incidência e sua morbiletalidade nos últimos anos. Os principais fatores de risco relacionados são uso de antibióticos, idosos e permanência hospitalar prolongada. Muitos pacientes recebem combinação de antibióticos ou múltiplos antibióticos, constituindo-se, assim, o principal fator de risco para o desenvolvimento de infecção ou de recorrência de diarreia associada ao C. difficile. Por isso, intervenções que otimizem a prescrição de antibióticos associado à aderência de medidas de controle de infecção podem reduzir aquisição dessa infecção. Assim, esta revisão aborda a mudança da epidemiologia da infecção por C. difficile e seu tratamento.

Preliminary investigation of environmental prevalence of Clostridium difficile affecting inpatients in a north Indian hospital.

A preliminary study was conducted to see the prevalence of Clostridium difficile in patients and their environment in a tertiary care hospital. Seventy-nine fecal specimens from hospitalized patients, 176 swab samples from beds and 48 from hands of hospital personnel were investigated. Sixty-three patients received antibiotics and 14 proton pump inhibitors. Abdominal pain was observed in 16 patients with fever in 15 of them. C. difficile culture was positive in 12.6% patients at initial sampling but none were toxin-positive. Eight patients developed diarrhea and five were both culture and toxin-positive. Fifty-one percent of bed swab samples and 62.5% of hand swab samples were culture positive. Similarly 8.5% of bed swab samples and 4.2% of hand swab samples were positive for toxins A and B. The environmental cross-infection between patients and carriage by hospital personnel are plausible sources of C. difficile infection and spread in our hospital.