Infectious Diarrheal Diseases Research Articles

Isolation of Enteropathogenic <italic>Escherichia coli</italic> (EPEC) From Raw Milk in Kermanshah by Polymerase Chain Reaction (PCR)

Background: Infectious diarrhoeal diseases cause major problems throughout the world and are responsible for considerable morbidity and mortality. Enteropathogenic Escherichia coli (EPEC) may cause infantile diarrhoea among children in developing countries. Objectives: The aim of this study was to define the prevalence of EPEC strains in raw milk samples. Materials and Methods: Raw milk samples collected from various cow farms in Kermanshah, Iran, during the period of 22nd June to 22nd September 2009 and were examined for EPEC presence using PCR reactions targeting eaeA, and then stx1 and stx2. Results: Of the 206 samples, 17 (8.25%) were contaminated with E. coli eaeA positive and stx1 and stx2 negative (EPEC). Conclusions: Our results confirm that raw milk recovered in Kermanshah may be a source for gastrointestinal infections by EPEC and strict preventive measures should be adopted to decrease contamination of milk with EPEC and other bacteria originated from animals.

Evidence that Cryptosporidium parvum populations are panmictic and unstructured in the Upper Midwest of the United States.

Cryptosporidium parvum is a zoonotic protozoan parasite that causes cryptosporidiosis, an infectious diarrheal disease primarily affecting humans and neonatal ruminants. Understanding the transmission dynamics of C. parvum, particularly the specific contributions of zoonotic and anthroponotic transmission, is critical to the control of this pathogen. This study used a population genetics approach to better understand the transmission of C. parvum in the Upper Midwest United States. A total of 254 C. parvum isolates from cases of human cryptosporidiosis in Minnesota and Wisconsin and diarrheic calves in Minnesota, Wisconsin, and North Dakota were genotyped at eight polymorphic loci. Isolates with a complete profile from all eight loci (n = 212) were used to derive a multilocus genotype (MLT), which was used in population genetic analyses. Among the 94 MLTs identified, 60 were represented by a single isolate. Approximately 20% of isolates belonged to MLT 2, a group that included both human and cattle isolates. Population analyses revealed a predominantly panmictic population with no apparent geographic or host substructuring.

Preventing acute gut wall damage in infectious diarrhoeas with glycosylated dendrimers

Intestinal pathogens use the host's excessive inflammatory cytokine response, designed to eliminate dangerous bacteria, to disrupt epithelial gut wall integrity and promote their tissue invasion. We sought to develop a non-antibiotic-based approach to prevent this injury. Molecular docking studies suggested that glycosylated dendrimers block the TLR4-MD-2-LPS complex, and a 13.6 kDa polyamidoamine (PAMAM) dendrimer glucosamine (DG) reduced the induction of human monocyte interleukin (IL)-6 by Gram-negative bacteria. In a rabbit model of shigellosis, PAMAM-DG prevented epithelial gut wall damage and intestinal villous destruction, reduced local IL-6 and IL-8 expression, and minimized bacterial invasion. Computational modelling studies identified a 3.3 kDa polypropyletherimine (PETIM)-DG as the smallest likely bioactive molecule. In human monocytes, high purity PETIM-DG potently inhibited Shigella Lipid A-induced IL-6 expression. In rabbits, PETIM-DG prevented Shigella-induced epithelial gut wall damage, reduced local IL-6 and IL-8 expression, and minimized bacterial invasion. There was no change in β-defensin, IL-10, interferon-β, transforming growth factor-β, CD3 or FoxP3 expression. Small and orally delivered DG could be useful for preventing gut wall tissue damage in a wide spectrum of infectious diarrhoeal diseases.–>See accompanying article http://dx.doi.org/10.1002/emmm.201201668

Adenoviruses in Fecal Samples from Asymptomatic Rhesus Macaques, United States

Adenoviruses can cause infectious diarrheal disease or respiratory infections in humans; 2 recent reports have indicated probable human infection with simian adenoviruses (SAdVs). To assess the possibility of animal-to-human transmission of SAdVs, we tested fecal samples from asymptomatic rhesus macaques housed in 5 primate facilities in the United States and cultured 23 SAdV isolates. Of these, 9 were purified and completely sequenced; 3 SAdV samples from the American Type Culture Collection (SAdV-6, SAdV-18, and SAdV-20) were also completely sequenced. The sequence of SAdV-18 was closely related to that of human adenovirus F across the whole genome, and the new isolates were found to harbor 2 fiber genes similar to those of human adenovirus (HAdV) strains HAdV-40 and HAdV-41, which can cause infectious diarrhea. The high prevalence of adenoviruses in fecal samples from asymptomatic rhesus macaques and the similarity of the isolates to human strains indicates the possibility of animal-to-human transmission of SAdVs.

Guanylate cyclase C signaling: an intestinal secretory pathway where bugs, genes and new drugs intersect

Acute infectious and chronic diarrheal diseases are important public health problems. A recent study by Fiskerstrand and colleagues identified a family with a rare early onset familial diarrhea. By linkage analysis and exon sequencing, the authors identified a heterozygous missense mutation in GUCY2C, encoding the guanylate cyclase C receptor, which is involved in intestinal secretion. This newly identified gene in the etiology of a familial diarrhea provides a candidate target for the development not only of new treatments for diarrhea, but also of a new drug class to treat constipation.

Translational Repression of Down‐Regulated in Adenoma by miR‐494 in Caco2 Cells

Down‐regulated in adenoma (DRA) is a Cl−/HCO3 − exchanger involved in electroneutral NaCl transport in the mammalian intestine. Altered DRA expression levels are associated with infectious and inflammatory diarrheal diseases. Therefore, it is critical to understand the regulation of DRA expression. MicroRNAs are endogenous, small RNAs that regulate protein expression via blocking the translation and/or promoting mRNA degradation. In order to investigate potential modulation of DRA expression by microRNA, five different in silico algorithms were used to predict the microRNAs that target DRA. Of these microRNAs, miR‐494 was shown to have highly conserved putative binding site in the DRA 3′untranslated region (3′UTR) compared to other DRA‐targeting microRNAs in vertebrates. Transfection with pMIR‐GLO dual luciferase vector containing DRA 3′UTR resulted in a significant decrease in relative luciferase acitivity (44.13 ± 3.7% p<0.05) as compared to empty vector. Co‐transfection of the DRA 3′UTR luciferase vector with a miR‐494 mimic resulted in markedly decreased luciferase activity (69.58 ± 2.1% p<0.05), as compared to cells transfected with negative control. The transfection of a miR‐494 mimic into Caco2 cells significantly increased the expression of miR‐494 and concomitantly decreased the DRA protein expression by (50.5 ± 5.2% p<0.05). These data demonstrate a novel regulatory pathway for DRA and indicate that targeting miR‐494 using anti‐miR‐494 could be an effective therapeutic tool for diarrheal conditions. (Supported by NIDDK/VA)

Translational Approaches for Pharmacotherapy Development for Acute Diarrhea

Areport is presented of a National Institute of Diabetes and Digestive and Kidney Diseases–sponsored single topic conference designed to determine scientific advances needed to encourage development of pharmacotherapy for diarrheal diseases. Acute diarrheal diseases are a global public health problem in developing and developed countries. They are a leading cause of mortality and morbidity for children under the age of 5 worldwide and have a major economic impact in developed countries. Although oral rehydration solution (ORS) along with oral zinc therapy has reduced mortality owing to acute diarrheal diseases, there are essentially no other approved, safe, and effective drugs to decrease stool volume and prevent fluid loss. On September 25–27, 2011, the National Institute of Diabetes and Digestive and Kidney Diseases convened a workshop on Translational Approaches for Pharmacotherapy Development for Acute Diarrhea to assess current treatments for acute diarrhea, to identify common host pathways targeted by infectious agents associated with acute diarrhea, to evaluate which pathophysiologic mechanisms are most clinically relevant as potential targets, and to identify promising areas for translational research.

Prevalence of Viruses with Diarrhea among Hospitalized Children West Gyeonggi Province

Purpose:This study was conducted to evaluate epidemiological data of the viral pathogens obtained from stool exams and provide information on the regional prevalence of infectious diarrheal disease west in Gyeonggi Province, Korea. Methods:We enrolled a cohort of children <10 years of age admitted for treatment of acute diarrhea at Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea. In total, 310 fecal specimens, documented to be free of common bacterial pathogens, were collected from pediatric patients during a 12-month period from January to December 2009 and were tested for the presence of rotavirus, parechovirus, adenovirus, astrovirus, enterovirus, and norovirus using polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR) assay. Results:The most common virus was parechovirus (16%), followed by adenovirus (15%), astrovirus (14%), rotavirus (13%), and enterovirus (5%). Interestingly, only one of the specimens was positive for norovirus. Single infection cases were detected in 173 (55.8%) of the 310 children, whereas mixed viral infections were detected in 10 (3.2%) of the same children. Viral gastroenteritis generally showed a double peak of incidence. Parechovirus, rotavirus, and adenovirus shared a similar pattern of peak incidence with overall viruses; however, astrovirus infections occurred more frequently in the spring. Eighty-five percent of the confirmed viral gastroenteritis cases developed in under 24 months. Conclusion:The results support the importance of parechovirus, adenovirus, astrovirus, and enterovirus as causative agents of diarrhea in children, which may be underestimated by current routine diagnostic testing. (Korean J Pediatr Infect Dis 2012;19:28-36)

Enhancing the Teaching of Evolution in Public Health.

Public health courses are emerging as popular undergraduate offerings, especially at universities with schools of public health. It is important to note that evolution has shaped the burden of disease in the modern world in which we practice and educate for public health. Human cultures and technologies have modified life on Planet Earth and have co-evolved with myriad other species, including microorganisms, plant and animal sources of food, invertebrate vectors of disease, and intermediate bird, mammal, and primate hosts. Molecular mechanisms of evolution have produced differential resistance or susceptibility to infectious agents, including malaria, plague, smallpox, TB, measles, and diarrheal and respiratory diseases. The domestication of sheep and cattle led to natural selection in favor of human populations able to digest milk throughout life through persistence into adulthood of lactase enzyme expression in the intestine, a major story of anthropology. The emergence of a “Western diet” of dairy, refined cereal grains, refined sugars, vegetable oils, alcoholic beverages, salt, and omega-6-rich meats has dramatically altered glycemic load, fatty acid composition, macronutrients, acid–base balance, sodium/potassium ratio, and fiber content. This is a major story of nutrition and disease. The results include epidemics of atherosclerotic cardiovascular disease, obesity, diabetes, high blood pressure, osteoporosis, certain cancers, and bowel, inflammatory, and autoimmune disorders. Another interesting phenomenon is the selection of excessive hemostatic activity from platelets and the plasma clotting proteins; what was protective against death from bleeding after injuries among hunter–gatherers or from pregnancy-related hemorrhage now contributes to thrombosis underlying heart attacks and strokes. Conversely, there is little pressure against hemostasis and thrombosis since deaths from these causes occur mostly after the reproductive years of life. Learning about evolution over millennia for humans and over hours or days for microbes enlivens the experience of understanding evolutionary biology in public health context.

Detection of diarrhoeal pathogens in human faeces using an automated, robotic platform

Infectious diarrhoeal diseases represent a major socio-economic burden to humans, and are linked to a range of pathogens, including viruses, bacteria and protists. The accurate detection of such pathogens is central to control. However, detection often relies on methods that have limited diagnostic sensitivity and specificity. Here, we assessed an automated, robotic platform for the simultaneous detection of eight major pathogens associated with infectious diarrhoea. Genomic DNA samples ( n = 167) from faeces from humans with diarrhoea and diagnosed as cryptosporidiosis, and 100 uninfected control subjects, were tested for adenovirus 40/41, norovirus, Clostridium difficile, Campylobacter, Salmonella, Shigella, Cryptosporidium and Giardia by multiplexed-tandem PCR, and also characterized by single-strand conformation polymorphism analysis (SSCP) and selective sequencing. All 167 samples tested positive for Cryptosporidium, five for adenovirus 40/41, four for Campylobacter, three for C. difficile and seven for Shigella spp., with no false positive results for any assay. The automated PCR exhibited a high sensitivity, with <10 individual pathogens being readily detected. The robotic detection platform assessed here represents a sensitive, high-throughput tool for key pathogens linked to infectious diarrhoea in humans. This platform requires little molecular biological expertise and is well suited to various diagnostic facilities and settings.

Prenatal Maternal Zinc Supplements Reduce Infant Diarrhea

Research Article| October 01 2010 Prenatal Maternal Zinc Supplements Reduce Infant Diarrhea AAP Grand Rounds (2010) 24 (4): 43. https://doi.org/10.1542/gr.24-4-43 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Prenatal Maternal Zinc Supplements Reduce Infant Diarrhea. AAP Grand Rounds October 2010; 24 (4): 43. https://doi.org/10.1542/gr.24-4-43 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: infantile diarrhea, prenatal care, zinc supplement, diarrhea Source: Iannotti L, Zavaleta N, Leon Z, et al. Maternal zinc supplementation reduces infectious disease morbidity in Peruvian infants. J Pediatr. 2010; 156(6): 960– 964; doi: https://doi.org/10.1016/j. jpeds.2009.12.023Google Scholar Investigators from the US and Peru performed this double-blind randomized controlled trial in a peri-urban slum of Lima, Peru between 1995 and 1997 to assess the effect of zinc supplementation during pregnancy on subsequent infectious diseases through infancy. Researchers enrolled 1,295 women between 10 and 24 weeks gestation who were carrying a low-risk singleton pregnancy. These women were stratified by gestational age (less than or more than 17 weeks) and parity (nulliparous or multiparous) and then randomized to take a daily supplement of 60 mg of iron and 250 μg of folic acid either with or without 15 mg of zinc. The two tablets were otherwise indistinguishable, and were taken from 10 to 24 weeks gestation until one month postpartum. Socioeconomic and household characteristics and maternal anthropometric measurements were recorded. Infant weights were recorded at birth and then monthly for 12 months. Morbidity surveillance was done by field workers through weekly home visits. Of the 421 infants who completed the 12-month study, 214 received zinc supplementation. There were no differences between the zinc-supplemented and control groups with regard to socioeconomic or household characteristics, gestational age at birth, or birth weight. Adjusting for the age of the infant, breastfeeding, season, and sanitation and hygiene covariates, prenatal zinc supplementation reduced the risk of a diarrheal episodes lasting more than seven days by 34% (OR 0.66; 95% CI, 0.43–0.99; P=.04) and decreased the presence of mucus in the stool (OR 0.65; 95% CI, 0.46–0.92; P=.01) as compared to controls. The mean observed days with diarrhea among infants prenatally treated with zinc (5.8%) was less than infants in the control group (7.7%; P=.01). There was a trend toward fewer diarrheal episodes (≥3 liquid or loose stools in 24-hour period) in the prenatal zinc-supplemented group. No effect was detected for respiratory illnesses, fever, scabies, or impetigo. The authors conclude that prenatal zinc supplementation decreased diarrhea-associated morbidity in offspring during the first 12 months of life. In 2009, the World Health Organization recommended that zinc be added to oral rehydration therapy in the treatment of acute diarrhea. 1 The authors of this article propose an immunological basis to explain the beneficial effect from prenatal zinc supplementation. Zinc deficiency in humans decreases the activity of serum thymulin (a thymic hormone), which is required for maturation of T-helper cells and plays an important role in cell-mediated immune function and also functions as an anti-inflammatory and antioxidant agent.2 Infectious diarrheal diseases are the second leading cause of morbidity and mortality worldwide.3 Zinc deficiency places children at increased risk of illness and death from diarrhea.4 Zinc deficiency is prevalent in low-income countries, as this micronutrient is mainly found in expensive red meat. Pooled analysis of studies that have assessed the effect of... You do not currently have access to this content.

Use of dried kapenta (Limnothrissa miodon and Stolothrissa tanganicae) and other products based on whole fish for complementing maize-based diets

Poor nutritional status both for children and adults is highly prevalent in those parts of sub-Saharan Africa where maize is a dominant staple. Maize is not a complete food, and if the child’s diet is only based on white maize, it may be deficient in calcium, vitamin A, vitamin C, vitamin B12, vitamin E, vitamin K, folate, riboflavin, pantothenic acid, niacin, potassium and iron. Inadequate intake of essential amino acids, vitamins, minerals and trace elements is associated with reduced growth, weakening of immunological functions and enhanced morbidity and mortality from infectious diseases, including measles, diarrhoeal diseases, parasite infestations, tuberculosis and HIV disease. Pregnant women and people suffering from infectious diseases, including HIV and tuberculosis, need a diet rich in protein and micronutrients. During pregnancy, growth requirements for the foetus must be covered. Infections lead to significant metabolic changes with enhanced rates of degradation or excretion of several nutrients including total protein, essential amino acids and vitamins. The diet must now contain higher amounts of nutrients than required by a healthy child or adult person in order to prevent the development of protein malnutrition and micronutrient deficiencies that will in turn easily lead to weakening of immunological functions. The purpose of the study was i) to analyse the nutrient composition of kapenta, and compare it to other animal products, and ii) to calculate the quantity of these products needed to cover the recommended dietary intake of several nutrients. Nutrient compositions of whole dried kapenta and Norwegian fish powder (fish protein concentrate type B) were found to be similar. It is shown that products made from whole fish are qualitatively superior to fish fillet and other animal products because they are much better sources of minerals and trace elements such as calcium, iron and zinc. They are also good sources of vitamin B12 and other bioactive substances such as membrane lipids, taurine and nucleic acids. Calculations of the improvements in nutrient intake if a maize-based diet is supplemented with minor amounts of a micronutrient- and protein-rich food like dried kapenta, or fish meal, was shown to give a balanced diet covering most of the nutrient requirements. It should be noted that patients suffering from chronic infectious diseases such as AIDS and tuberculosis have higher nutrient requirements (for protein, essential amino acids and several micronutrients) compared to healthy persons. Key words : Nutrition, children, maize, kapenta, fish-meal

Three-Hour Molecular Detection of Campylobacter , Salmonella , Yersinia , and Shigella Species in Feces with Accuracy as High as That of Culture

Campylobacter jejuni and Salmonella, Shigella, and Yersinia species (along with Shiga toxin-producing Escherichia coli) are the most common causes of acute bacterial diarrheal disease in the United States. Current detection techniques are time-consuming, limiting usefulness for patient care. We developed and validated a panel of rapid PCR assays for the detection and identification of C. jejuni, C. coli, Salmonella, and Yersinia species and Shigella and enteroinvasive E. coli in stool samples. A total of 392 archived stool specimens, previously cultured for enteric pathogens, were evaluated by PCR. Overall, 104 stool specimens had been culture positive (C. jejuni/coli [n = 51], Salmonella species [n = 42], Shigella species [n = 6], and Yersinia species [n = 5]). Compared to culture, the overall sensitivity and specificity of PCR detection of these organisms were 92 and 98% (96/104 and 283/288), respectively, from fresh or Cary Blair stool (P = 0.41); 87 and 98% (41/47 and 242/246), respectively, from fresh stool (P = 0.53); and 96 and 98% (55/57 and 41/42), respectively, from Cary Blair stool (P = 0.56). For individual genera, PCR was as sensitive as the culture method, with the exception of Salmonella culture using selenite enrichment for which PCR was less sensitive than culture from fresh, but not Cary Blair (P = 0.03 and 1.00, respectively) stools. This PCR assay panel for the rapid diagnosis of acute infectious bacterial diarrheal pathogens has a sensitivity and specificity equivalent to that of culture for stools in Cary Blair transport medium. Paired with reflexive culture of stools testing positive, this should provide an improvement in care for patients with acute infectious diarrheal disease.

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

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 SeeplexR 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. (Korean J Clin Microbiol 2010;13:162-168)

Enteropathogenic Escherichia coli Infection Inhibits Intestinal Serotonin Transporter Function and Expression

Serotonin transporter (SERT) plays a critical role in regulating serotonin (5-hydroxytryptamine [5-HT]) availability in the gut. Elevated 5-HT levels are associated with diarrheal conditions such as irritable bowel syndrome and enteric infections. Whether alteration in SERT activity contributes to the pathophysiology of diarrhea induced by the food-borne pathogen enteropathogenic Escherichia coli (EPEC) is not known. The present studies examined the effects of EPEC infection on SERT activity and expression in intestinal epithelial cells and elucidated the underlying mechanisms. Caco-2 cells as a model of human intestinal epithelia and EPEC-infected C57BL/6J mouse model of infection were utilized. SERT activity was measured as Na(+) and Cl(-) dependent (3)[H] 5-HT uptake. SERT expression was measured by real-time quantitative reverse-transcription polymerase chain reaction, Western blotting, and immunofluorescence studies. Infection of Caco-2 cells with EPEC for 30-120 minutes decreased apical SERT activity (P < .001) in a type 3 secretion system dependent manner and via involvement of protein tyrosine phosphatases. EPEC infection decreased V(max) of the transporter; whereas cell surface biotinylation studies revealed no alteration in the cellular or plasma membrane content of SERT in Caco-2 cells. EPEC infection of mice (24 hours) reduced SERT immunostaining with a corresponding decrease in SERT messenger RNA levels, 5-HT uptake, and mucosal 5-HT content in the small intestine. Our results demonstrate inhibition of SERT by EPEC and define the mechanisms underlying these effects. These data may aid in the development of a novel pharmacotherapy to modulate the serotonergic system in treatment of infectious diarrheal diseases.

Acute infectious diarrhea in children.

Acute infectious enteritis is one of the more common childhood diseases worldwide, especially in the first three years of life. Every year, in Germany, one in six children under age 5 is taken to a physician at least once because of infectious diarrheal disease. 10% of the children presenting with rotavirus infection are admitted to hospital. The existing national and international recommendations for the treatment of acute infectious diarrheal disease are inadequately followed, despite the high level of evidence on which they are based. Selective literature search based on national and international guidelines. The therapeutic goal is to replace the fluid and electrolyte losses resulting from diarrhea and vomiting. The administration of a hypotonic oral rehydration solution (ORS) is indicated to treat impending dehydration (infants aged up to 6 months with diarrhea and/or more than 8 watery stools in the last 24 hours and/or more than 4 episodes of vomiting in the last 24 hours), or when mild or moderate dehydration is already present. Oral rehydration with ORS given in frequent, small amounts over 3-4 hours is successful in more than 90% of cases. Regular feeding can be begun immediately afterward. Laboratory testing of blood or stool is usually unnecessary. Children who can be rehydrated orally or through a nasogastric tube should not be given intravenous fluids.

Molecular diagnosis and antimicrobial resistance pattern of Shigella spp. isolated from patients with acute diarrhea in Tehran, Iran

Aim: To evaluate antimicrobial resistance pattern of Shigella spp. isolated from patients with acute diarrhea in Tehran, Iran. Background : Infectious diarrheal diseases caused by Shigella spp. are significant health concern world wide. They are responsible for considerable morbidity and mortality especially in developing countries. Patients and methods : A total of 1120 fecal samples from patients with acute diarrhea from May 2003 to May 2005 were investigated to evaluate antimicrobial susceptibility patterns of predominant isolates from different hospitals in Tehran, Iran. Identification of isolates was carried out according to standard methods. Results : Among isolated enteropathogens, Shigella spp. were found in 14%. Shigella sonnei was commonest (56.1%) followed by Shigella flexneri, boydii and dysenteriae that were found in 30.6%, 8.3% and 5.1% of isolates, respectively. Of all isolates, 66.3% were detected in patients less than 5 years old. Resistance pattern was as follow: tetracycline 95.5%, ampicillin 51.5% and trimethoprim-sulfamethoxazole 91.7%. None of the isolates were resistant to ciprofloxacin, ceftriaxone and ceftazidime. An interesting finding in our study was a high degree of multidrug resistance to 3 and more antibiotics among isolates 91%. Conclusion : In conclusion, Shigella species isolated from acute diarrhea in Iran have a high degree of resistance to commonly used antibiotics. The emergence of multidrug-resistance demands continues monitoring of susceptibility pattern of Shigella isolates. The changing of resistance pattern to common antibiotics in Iran indicates that designing a monitoring system for detection of antimicrobial resistance and guidelines for the appropriate use of antibiotics are urgently needed.

NITAZOXANIDE IN THE TREATMENT OF DIARRHEA IN CHILDREN

Background: Infectious diarrheal diseases are the second leading cause of morbidity and mortality worldwide. Diagnosis of the various etiological causes of diarrhea is often problematic in terms of cost, time and sensitivity, potentially delaying appropriate treatment. Methods: A double blind, placebo-controlled clinical trial of nitazoxanide in children with diarrheal illness lasting >3 days and <30 days was conducted at the Regional Hospital of Cajamarca, Peru. Fecal samples collected at baseline were subjected to ova and parasite examination, enzyme immunoassay for enteric viruses and coproculture. Patients were randomized to receive the standard 3-day course of nitazoxanide suspension or placebo suspension. Daily follow-up was performed for 7 days. The primary efficacy endpoint was time from first dose to resolution of all symptoms analyzed by Kaplan-Meier survival analysis and Prentice modified Wilcoxon test. Results: One-hundred children (median age: 30 months, IQR, 20-47) were enrolled in the study. The median time to resolution of symptoms for nitazoxanide-treated patients was 1 day vs. 3 days for the placebo group (P < 0.0001). The most common enteropathogens were Giardia lamblia (32%), rotavirus (12%), Escherichia coli (7%), adenovirus (4%), Blastocystis hominis (2%) and Shigella sonnei (2%). 38% had no identifed enteropathogen. The effect of nitazoxanide was observed in subsets of patients with G. lamblia (P = 0.0008), rotavirus (P = 0.0143) and with no identifed enteropathogen (P = 0.0028). The medication was well tolerated. Conclusions: Nitazoxanide reduced the duration of diarrheal illness of multiple etiologies. These results suggest that nitazoxanide may be a good therapeutic option for diarrheal illness in children where the etiology is unknown or presumed to be of infectious origin.

Epidemiological Study of Viral Diarrhea in Gwangju Area During 2000~2002

There are well known infectious diarrheal disease including viral disease such as HuCVs (Human caliciviruses), rotaviruses, enteric adenoviruses and astroviruses. We performed surveillance of infectious diarrheal disease in this study for providing the information for regional prevalence of infectious diarrheal disease and establish basement of diagnostic scheme for these infectious diarrheal disease. For the study, 3,400 stool specimens collected from 10 hospitals in Gwangju from April 2000 to March 2002 were used in investigation for the detection of infectious diarrheal disease. For group A rotaviruses, enteric adenoviruses and astrovirus, we carried out antigen capturing ELISA and RT-PCR with specific primers reacting RNA dependent RNA polymerase gene of HuCVs is used for the detection of RNA of HuCVs. As a results, we detected viral antigen or genome from 537 out of 3,400 specimens (15.8%). 443 out of 537 (82.5%) were confirmed as rotaviruses antigen positively, and 14 (2.6%) and 3 (0.8%) samples were antigen positive to enteric adenoviruses and astroviruses, respectively. We detected HuCV genome from 73 (13.6%) samples by specific amplification. We found that predominantly causative virus is rotavirus in Gwangju but HuCVs take major portion of viral agents causing diarrhea considering the age and seasonal distribution of specimens. Prevalence of adenoviruses and astroviruses are very low compared with worldwide situation. While the infection of rotavirus is limited to young infant under 2 years old, infection of HuCV has wide age distribution. These results suggest that existence of various strains of HuCVs and low rate of cross-protection among distinct antigenic group make it difficult to form immunity in older age. This epidemiological information relating to various diarrheic viruses is first reported in Gwangju, therefore it could provide present prevalence of viral agents causing gastroenteritis and backgrounds to establishment of protection viral diarrhea and development.

Clinical Concerns About Reduced-Osmolarity Oral Rehydration Solution

Demonstration of the benefits of oral therapy for cholera in 1968 soon led to application of the method to all forms of infectious diarrheal diseases. The original oral rehydration solution (ORS) formulation developed by the World Health Organization (WHO) struck a compromise between the ideal solutions for these diverse disorders to meet the programmatic goal of a single formulation and packaging for global use in cholera and noncholera diarrheas in both adults and children. Recently WHO recommended a new oral solution for all acute diarrheas including cholera. This new formula would replace the original ORS which saved millions of lives with a new formulation containing less sodium and glucose. This change was ostensibly to reduce gross stool volume and use of unscheduled intravenous therapy by lowering solution osmolarity. However the reduced-osmolarity formulation is particularly unsuitable for universal use because it contains an amount of sodium insufficient to maintain sodium balance in cholera patients in whom its use induces negative sodium balance and may lead to hyponatremia polyuria and a small but clinically significant risk of neurologic complications. The new reduced-osmolarity formulation stretches the original compromise to the breaking point. It may be time to promote use of different solutions for patients with cholera beginning in controlled settings such as cholera treatment centers and hospitals. (authors)