Principales agentes etiológicos de las enfermedades diarreicas agudas infantiles en Chimborazo, Ecuador / Main etiological agents of childhood acute diarrheal diseases in Chimborazo, Ecuador

Las enfermedades diarreicas constituyen la principal causa de morbimortalidad en niños menores de cinco años, con alrededor de 1.700 millones de casos y 1,5 millones de muertes por año a nivel mundial. Para el año 2010, en la Sierra de Ecuador se registró un alto porcentaje de infantes fallecidos a causa de enfermedades diarreicas agudas (EDA), incluyendo la provincia de Chimborazo; mientras que, para el año 2016, se registraron en Ecuador 590.523 casos de EDA, siendo más afectados los niños de sectores de mayor pobreza. Se realizó un estudio descriptivo en pacientes pediátricos con episodios diarreicos que acudieron a centros de salud de los cantones rurales de la provincia Chimborazo. Se realizó análisis coprológico y coproparasitológico en 258 muestras; se identificaron bacterias enteropatógenas mediante pruebas bioquímicas y de susceptibilidad antimicrobiana, se realizó diagnóstico parasitológico mediante análisis macroscópico y microscópico y para detección de virus se emplearon pruebas inmunológicas. Se observó un mayor número de casos de EDA en los cantones Alausí (50%) y Chunchi (19%). De los pacientes con EDA, los rotavirus son el principal agente etiológico aislado (24,8%), seguido por Shigella (17,8%); mientras que Giardia intestinalis (8,5%) y Salmonella (10,1%) son los microorganismos que se aislaron con menor frecuencia en las muestras. Los resultados del presente estudio, permiten tener un panorama etiológico de las EDA en la provincia de Chimborazo y contribuir en la vigilancia epidemiológica, ejecución de programas sanitarios y de vacunación, para disminuir la vulnerabilidad de la población infantil ante dichas infecciones(AU)

Diarrheal diseases are the main cause of morbidity and mortality in children under five years of age, with around 1.7 billion cases and 1.5 million deaths per year worldwide. For the year 2010, in the Sierra de Ecuador a high percentage of infants died due to acute diarrheal diseases (ADD), including the province of Chimborazo; while, for the year 2016, 590,523 cases of ADD were registered in Ecuador, with children from the poorest sectors being more affected. A descriptive study was carried out in pediatric patients with diarrheal episodes who attended health centers in the rural cantons of Chimborazo province. Coprological and coproparasitological analysis was performed on 258 samples; Enteropathogenic bacteria were identified by biochemical and antimicrobial susceptibility tests, a parasitological diagnosis was made by macroscopic and microscopic analysis, and immunological tests were used to detect viruses. A greater number of ADD cases was observed in the Alausí (50%) and Chunchi (19%) cantons. Of patients with ADD, rotaviruses are the main etiological agent isolated (24.8%), followed by Shigella (17.8%); while Giardia intestinalis (8.5%) and Salmonella (10.1%) are the microorganisms that were isolated less frequently in the samples. The results of this study allow us to have an etiological panorama of EDA in the province of Chimborazo and contribute to epidemiological surveillance, execution of health and vaccination programs, to reduce the vulnerability of the child population to these infections(AU)

High Frequency of Enteric Protozoan, Viral, and Bacterial Potential Pathogens in Community-Acquired Acute Diarrheal Episodes: Evidence Based on Results of Luminex Gastrointestinal Pathogen Panel Assay

Infectious diarrhea is endemic in most developing countries. We aimed to investigate the protozoan, viral, and bacterial causes of acute diarrhea in Taif, Saudi Arabia. A cross-sectional prospective 1-year study was conducted on 163 diarrheal patients of various ages. Stool samples were collected, 1 per patient, and tested for 3 protozoa, 3 viruses, and 9 bacteria with the Luminex Gastrointestinal Pathogen Panel. Overall, 53.4% (87/163) of samples were positives (20.8% protozoa, 19.6% viruses, 2.8% bacteria, and 9.8% mixed). Rotavirus (19.6%), Giardia duodenalis (16.5%), and Cryptosporidium spp. (8.5%) were the mostly detected pathogens. Adenovirus 40/41 (4.2%), Salmonella (3%), Shiga toxin-producing Escherichia coli (3%), and Entamoeba histolytica (2.4%) were also detected. Norovirus GI/II, Vibrio cholerae, Yersinia enterocolitica, and Clostridium difficile toxin A/B were not detected in any patients. All pathogens were involved in coinfections except E. histolytica. Giardia (5.5%) and rotavirus (3%) were the most commonly detected in co-infections. Enterotoxigenic E. coli (2.4%), Campylobacter spp. (2.4%), E. coli 0157 (1.8%), and Shigella spp. (1.2%) were detected in patients only as co-infections. Infections were more in children 0–4 years, less in adults 40 years, with statistically significant differences in risk across age groups observed with rotavirus (P < 0.001), Giardia (P=0.006), and Cryptosporidium (P=0.036) infections. Lastly, infections were not significantly more in the spring. This report demonstrates the high burden of various enteropathogens in the setting. Further studies are needed to define the impact of these findings on the clinical course of the disease.

Jejunal hemorrhage syndrome in a Zebu cow in Brazil / Síndrome de jejuno hemorrágico em gado Zebu no Brasil

Clostridium perfringens type A has been incriminated as the etiologic agent in jejunal hemorrhage syndrome (JHS), which is a disease that affects dairy cattle. Although this microorganism is considered an important enteropathogen the pathogenesis of JHS is still not clear, and there have been no reports of its occurrence in Brazil so far. The aim of this study was to describe the occurrence of JHS by infection with a C. perfringens type A strain carrying the beta-2 toxin gene in a zebu cow in Brazil, for the first time.

Clostridium perfringens tipo A tem sido considerado agente etiológico da síndrome do jejuno hemorrágico (SJH), que é uma doença que afeta comumente os rebanhos de gado. Embora este microrganismo seja considerado um importante enteropatógeno, a patogênese da SJH ainda não foi elucidada, e não havia sido reportada no Brasil até então. O alvo deste estudo foi descrever pela primeira vez a ocorrência da SJH causada por C. perfringens tipo A, carreador do gene da toxina beta-2, em um zebuíno no Brasil.

Direct Application of Multiplex PCR on Stool Specimens for Detection of Enteropathogenic Bacteria / 대한임상미생물학회지

BACKGROUND: Causative bacterial agents of infectious diarrheal disease were traditionally diagnosed by stool cultures. Stool culture, however, has a problem because of relatively low sensitivity and long turnaround time. In this study, we evaluated multiplex PCR applied on stool specimens directly to diagnose enteropathogenic bacteria. METHODS: From June to September 2009, 173 diarrheal stools submitted for stool cultures were tested by Seeplex(R) Diarrhea ACE Detection kit (Seegene, Korea) to detect 10 enteropathogenic bacteria. Specimens were cultured for Salmonella, Shigella, Vibrio, and Yersinia. Late 50 specimens were also cultured for Campylobacter. The specimens positive for verotoxin-producing Escherichia coli (VTEC) were further subcultured for detecting enterohaemorrhagic Escherichia coli O157:H7. Electronic medical records were reviewed for clinical and laboratory findings. RESULTS: Of 173 specimens, multiplex PCR and cultures identified enteropathogens in 36 (20.8%) and 8 specimens (4.6%), respectively. While multiplex PCR detected 5 Salmonella, 15 Campylobacter, 1 Vibrio, 4 Clostridium difficiles toxin B, 5 Clostridium perfringens, 1 Yersinia enterocolitica, 5 Aeromonas, and 2 VTEC, cultures detected 5 Salmonella, 1 Vibrio, 1 Y. enterocolitica, 1 Aeromonas, and 2 E. coli O157:H7. CONCLUSION: Multiplex PCR would be useful to detect Campylobacter, VTEC and C. perfringens, as well as have equivalent sensitivity to conventional culture for ordinary enteropathogens such as Salmonella, Shigella, Vibrio, Y. enterocolitica. Direct application of multiplex PCR combined with conventional cultures on stool warrants remarkable improvement of sensitivity to diagnose enteropathogenic bacteria.

Escherichia coli shigatoxigénica: Patogénesis, diagnóstico y tratamiento / Shigatoxigenic Escherichia coli: pathogenesis, diagnostic and treatment

Escherichia coli shigatoxigénica (ECST) pertenece al grupo de las bacterias productoras de diarrea, patología que aún constituye una de las principales causas de morbilidad en niños a nivel mundial. ECST produce una o más toxinas shiga (Stx1, Stx2 y sus variantes), que es su principal factor de patogenicidad, responsable de las complicaciones intestinales y sistémicas. La transmisión puede ocurrir de persona a persona, o a través de agua o alimentos contaminados. Su capacidad de producir brotes epidémicos y la gravedad de las complicaciones de la enteritis, es lo que le confiere a este microorganismo gran importancia en salud pública. Este patógeno no se detecta habitualmente en los laboratorios clínicos por las similitudes bioquímicas y clínicas con otros patógenos entéricos, siendo necesario métodos serológicos y moleculares para su identificación y caracterización definitiva. En este trabajo, hemos revisado la información disponible acerca de la patogenicidad, diagnóstico y tratamiento de la infección producida ECST.

Shigatoxigenic Escherichia coli (STES) belongs to the group of diarrhoea producing bacteria, pathology which still constitutes one of the main causes of morbility in children at a world wide level. STES produces one or more shiga toxins (Stx1, Stx 2 and their variants) which is their main pathogenicity factor, responsible for the intestinal and systemic complications. Transmission can occur person-to-person, or through contaminated water or food. Its capacity for producing epidemic outbreaks and the seriousness of the enteritis complications are what confers this microorganism great public health importance. This pathogen is not usually detected at clinical laboratories due to its biochemical and clinical similarities with other enterical pathogens, and it necessary to use serological and molecular methods for its definitive identification and characterization. In this paper, we have revised available information regarding pathogenicity, diagnosis and treatment of STES produced infections.

Development of a Multiplex PCR-Microarray Method for Detection of Important Enteropathogen / 中国生物工程杂志

Objective: To establish a multiplex PCR-microarray method for detecting important enteropahogens.Methods: Uniplex and multiplex PCR were performed to obtain the best primer sets for identifying the target bacteria at species and multi-species level.Fluorescent dyes were mixed into PCR reaction to determine whether it can affect the efficiency of amplification.To improve the efficiency of microarray,a 35 pairs primer-labeling system was optimized based on the hybridization results to find the best combination to avoid false negative results.Results: Specific PCR products were all obtained using species-specific primer sets.More preferential amplification may happen when more primer pairs were added to the reaction.The hybridization results showed a positive association between the efficiency of multiplex-PCR and signal intensity.Conventional PCR yielded more products than fluorescent dyes labeled PCR.Thirty-five primers were divided into three different combinations to label target respectively,hybridization results showed a high specificity.Conclusion: Mixing fluorescent dyes into PCR may reduce the efficiency of amplification and hybridization,but may have no effect on the analysis of hybridization results.The hybridization efficiency of microarray depends on the amplification efficiency of multiplex PCR.For microarray target labeling,three primer sets could be used to avoid negative hybridization led by preferential amplification of multiplex-PCR.It indicates that the multiplex PCR-microarray method is an attractive diagnosis tool for the high-throughput identification of enteropathogenic organisms especially for multiple causative agents and epidemiological investigations.

Diagnosis of Enteropathogens in Children with Acute Gastroenteritis: One Year Prospective Study in a Single Hospital / 대한소아소화기영양학회지

PURPOSE: Acute gastroenteritis in children is one of the frequently encountered diseases with relatively high admission rate. The aim of this study is to determine the isolation trends of common and emerging pathogens in acute gastroenteritis in children over a 12-month period in a community hospital. METHODS: The study group included the children who were hospitalized to Seoul National University Boramae Hospital from April, 2003 to March, 2004 or visited outpatient clinic from April, 2003 to July, 2003 with presenting features of acute gastroenteritis. Stool specimens were obtained within 2 days after the visit and examined for the following pathogens: rotavirus, adenovirus, Salmonella, Shigella, Vibrio, pathogenic Escherichia coli (E.coli), Campylobacter and Yersinia species. Viral study was done with commercial kits for antigen detection. Identification of the bacterial pathogens was done by culture using selective media. For pathogenic E.coli, polymerase chain reaction (PCR) was done with the target genes related to the pathogenecity of enterotoxigenic E.coli (ETEC), enteropathogenic E.coli (EPEC) and enterohemorrhagic E.coli (EHEC). RESULTS: The 130 hospitalized children and 28 outpatients were included in this study. The majority of children (>93%) were less than 6 years. Pathogens were isolated in 47% of inpatients and 43% of outpatients, respectively. Rotavirus was the most frequently identified pathogen, accounting for 42.3% of inpatients and 29.6% of outpatients. Nontyphoidal salmonella is the most commonly isolated bacterial pathogen (3.9%) in hospitalized children. Pathogenic E.coli (EPEC, ETEC) wasdetected in 2.1% (2/97) of inpatients and 25% (3/12) of outpatients. EHEC, adenovirus, Campylobacter, Yersinia and Shigella species were not detected in this study. CONCLUSION: Rotavirus is the most common enteropathogen in children with acute gastroenteritis. Nontyphoidal salmonella and pathogenic E.coli are important bacterial pathogens. Campylobacter species may not be commonly detected organism in hospitalized children with acute diarrhea.