The intestinal virome of malabsorption syndrome-affected and unaffected broilers through shotgun metagenomics.

Malabsorption syndrome (MAS) is an economically important disease of young, commercially reared broilers, characterized by growth retardation, defective feather development and diarrheic faeces. Several viruses have been tentatively associated to such syndrome. Here, in order to examine potential associations between enteric viruses and MAS, the faecal viromes of 70 stool samples collected from diseased (n = 35) and healthy (n = 35) chickens from seven flocks were characterized and compared. Following high-throughput sequencing, a total of 8,347,319 paired end reads, with an average of 231 nt, were generated. Through analysis of de novo assembled contigs, 144 contigs > 1000 nt were identified with hits to eukaryotic viral sequences, as determined by GenBank database. A number of known and unknown representatives of Adenoviridae, Anelloviridae, Astroviridae, Caliciviridae, Circoviridae, Parvoviridae, Picobirnaviridae, Picornaviridae and Reoviridae, as well as novel uncharacterized CRESS-DNA viruses, were identified. However, the distribution of sequence reads of viral genomes identified in diseased or healthy birds revealed no statistically significant differences. These findings indicate no association between the occurrence of MAS and enteric viruses. The viral genomes reported in the present study, including a variety of novel viruses, seem part of the normal intestinal microbiota of chickens.

Molecular detection of chicken parvovirus in broilers with enteric disorders presenting curving of duodenal loop, pancreatic atrophy, and mesenteritis.

Enteric disorders are an important cause of economic losses in broiler chickens worldwide. Several agents have been associated with enteric problems, such as viruses, bacteria, and parasites. In this study, broiler chickens showing signs of enteric disorders were subjected to molecular diagnosis for several viral agents and also for pathological examination for elucidating this problem. Thus, the chickens were screened for avian nephritis virus (ANV), chicken astrovirus (CAstV), avian rotavirus (ArtV), avian reovirus (AReoV), infectious bronchitis virus (IBV), fowl adenovirus group I (FAdV-1), and chicken parvovirus (ChPV). Postmortem examinations revealed a curving of the duodenal loop (J-like appearance) and intestines filled with liquid and gaseous content. Histopathological analysis of the duodenal loop showed pancreatic atrophy, acute mesenteritis, and enteritis. PCR results showed that ChPV was the sole viral agent detected in samples with lesions such as the curved duodenal loop and pancreatic atrophy. Molecular characterization of the nucleotide and deduced amino acid sequences revealed a high similarity with other strains of ChPV from Brazil, Canada, United States, Europe, and Asia. These findings suggest an association between ChPV and the development of enteritis, pancreatitis, and pancreatic atrophy, which may lead to curling of the duodenal loop. Together, these alterations may disrupt the normal functioning of the digestive system, diminishing digestion and the absorption of dietary nutrients and consequently leading to reduced weight gain, flock impairment, dwarfism, and an elevated feed conversion rate.

Aspectos funcionais, microbiológicos e morfológicos intestinais em crianças infectadas pelo vírus da imunodeficiência humana / Functional, microbiological and morphological intestinal findings among human immunodeficiency virus infected children

RACIONAL: O trato gastrointestinal é freqüentemente acometido nas crianças infectadas pelo vírus da imunodeficiência humana, com importantes repercussões no seu estado nutricional e sobrevida. A maioria dos estudos relacionados a esse tema foi desenvolvida com adultos, sendo menos investigado o problema nas crianças OBJETIVOS: Estudar aspectos digestivo-absortivos, microbiológicos e morfológicos intestinais em crianças infectadas pelo vírus da imunodeficiência humana MATERIAL E MÉTODOS: Onze crianças infectadas pelo vírus da imunodeficiência humana, menores de 13 anos, pertencentes às categorias clínicas A, B ou C, divididas em dois grupos: cinco pacientes com relato atual ou recente de diarréia e seis pacientes sem diarréia nos 30 dias que antecederam à inclusão no estudo. Investigação proposta: biopsia de intestino delgado e reto para análise morfológica e microbiológica, coprocultura, protoparasitológico de fezes, pesquisa de rotavírus, micobactérias e Cryptosporidium; teste da D-xilose RESULTADOS: Todos os pacientes testados (9/11) apresentavam má absorção da D-xilose (8,4-24,4 mg/dL). Os achados histopatológicos de intestino delgado foram inespecíficos, representados em sua maioria, por enteropatia grau I a II (6/10). Em todos os casos foi constatado aumento do infiltrado celular do córion. As alterações histopatológicas do reto também foram inespecíficas, com presença de aumento do infiltrado celular do córion. A pesquisa de microorganismos enteropatogênicos só foi positiva em dois casos, sendo identificado Mycobacterium avium intracellulare e Cryptosporidium nas fezes CONCLUSÕES: Demonstrou-se alta prevalência (100 por cento) de má absorção intestinal em crianças infectadas pelo vírus da imunodeficiência humana, com ou sem diarréia. Não foi possível estabelecer correlações quanto à presença de agentes enteropatogênicos, má absorção intestinal, alterações morfológicas intestinais e ocorrência ou não de diarréia. Não houve correlação...

BACKGROUD: Gastrointestinal tract disorders are frequent among human immunodeficiency virus infected children, with important repercussions on nutrition and survival. Most studies related to this subject were restricted to adults, being less investigated the problem in the children. AIMS: To study intestinal digestion, absorption, microbiological and morphological findings among human immunodeficiency virus infected children. MATERIAL AND METHODS: Eleven human immunodeficiency virus infected children under 13 years old, belonging to clinical categories A, B or C, separated in two groups: five patients with current or recent episode of diarrhea and six patients without diarrhea in the last 30 days preceding entering in study. Investigation proposed: microbiological and morphological analysis of small intestine and rectum biopsy; stool exams for bacterium, parasite, rotavirus, Mycobacterium species and Cryptosporidium; D-xylose test RESULTS: All tested subjects (9/11) had low D-xylose absorption (8,4 _ 24,4 mg d/L). Small intestinal mucosa histology findings were nonspecific, represented, in majority, of grade I/II enteropathy (6/10). Increased cellular infiltration of the chorion was observed in all specimens. Rectum histology alterations were also nonspecific, with chorion increased cellular infiltration. Mycobacterim avium intracellulare and Cryptosporidium were the solely microorganisms founded, both in stool CONCLUSIONS: Our study demonstrated high prevalence (100 percent) of intestinal malabsorption among human immunodeficiency virus infected children, despite the occurrence or not of diarrhea. It was not possible to establish relationships between the presence of microorganisms, intestinal malabsorption, intestinal morphologic findings and the occurrence or not of diarrhea. There was no correlation between D-xylose and intensity of villous atrophy.

[Functional, microbiological and morphological intestinal findings among human immunodeficiency virus infected children]. / Aspectos funcionais, microbiológicos e morfológicos intestinais em crianças infectadas pelo vírus da imunodeficiência humana.

BACKGROUND: [corrected] Gastrointestinal tract disorders are frequent among human immunodeficiency virus infected children, with important repercussions on nutrition and survival. Most studies related to this subject were restricted to adults, being less investigated the problem in the children. AIMS: To study intestinal digestion, absorption, microbiological and morphological findings among human immunodeficiency virus infected children. MATERIAL AND METHODS: Eleven human immunodeficiency virus infected children under 13 years old, belonging to clinical categories A, B or C, separated in two groups: five patients with current or recent episode of diarrhea and six patients without diarrhea in the last 30 days preceding entering in study. Investigation proposed: microbiological and morphological analysis of small intestine and rectum biopsy; stool exams for bacterium, parasite, rotavirus, Mycobacterium species and Cryptosporidium; D-xylose test RESULTS: All tested subjects (9/11) had low D-xylose absorption (8,4 _ 24,4 mg d/L). Small intestinal mucosa histology findings were nonspecific, represented, in majority, of grade I/II enteropathy (6/10). Increased cellular infiltration of the chorion was observed in all specimens. Rectum histology alterations were also nonspecific, with chorion increased cellular infiltration. Mycobacterim avium intracellulare and Cryptosporidium were the solely microorganisms founded, both in stool CONCLUSIONS: Our study demonstrated high prevalence (100%) of intestinal malabsorption among human immunodeficiency virus infected children, despite the occurrence or not of diarrhea. It was not possible to establish relationships between the presence of microorganisms, intestinal malabsorption, intestinal morphologic findings and the occurrence or not of diarrhea. There was no correlation between D-xylose and intensity of villous atrophy.

Experimental reproduction of malabsorption syndrome with different combinations of reovirus, Escherichia coli, and treated homogenates obtained from broilers.

Attempts to reproduce malabsorption syndrome (MAS) by oral inoculation with several different combinations including intestinal homogenate, reovirus, and hemolytic Escherichia coli obtained from MAS-affected chickens and intestinal homogenate from healthy chickens (healthy homogenate) were performed in 1-day-old specific-pathogen-free (SPF) broilers. The MAS homogenate, serving as a positive control, induced weight gain depression and intestinal lesions such as cystic crypts of Lieberkuhn, villus atrophy, and lymphoid and/or granulocytic infiltration. The healthy homogenate, the formalin-treated MAS homogenate, the formalin-treated healthy homogenate, and phosphate-buffered saline caused neither weight gain depression nor intestinal lesions. We were able to reproduce both weight gain depression and intestinal lesions by inoculation of reovirus either combined with the formalin-treated MAS homogenate or combined with healthy homogenate. Surprisingly, when hemolytic E. coli was added to the combination of reovirus with formalin-treated MAS homogenate, this did not cause weight gain depression although this combination caused the described intestinal lesions. Identical results were obtained with the combination of formalin-treated MAS homogenate with hemolytic E coli or the combination of reovirus with hemolytic E. coli. The intestinal lesions were more severe and developed faster by combinations including reovirus and formalin-treated MAS homogenate. This study indicates that a combination of enteropathogenic reovirus with other agents or substances that are present in an intestinal homogenate from MAS-affected and healthy chickens can induce MAS in SPF broilers. Escherichia coli is not essential for induction of weight gain depression but can play a role in development of intestinal lesions. Furthermore, intestinal lesions alone will not always result in weight gain depression.

Duodenal biopsies of HIV-infected patients with diarrhoea exhibit epithelial barrier defects but no active secretion.

OBJECTIVES: To characterize diarrhoeal mechanisms in HIV-infected patients, epithelial transport and barrier function of the duodenal mucosa was investigated in vitro. PATIENTS: Twenty-one HIV-seropositive patients (13 asymptomatic and eight with diarrhoea) and 12 controls from an urban referral-based tertiary care centre in Berlin who underwent duodenoscopy. METHODS: A new miniaturized Ussing chamber allowed measurements on duodenal forceps biopsies. Epithelial barrier function was characterized by alternating current impedance analysis, which allows differentiation of epithelial and subepithelial resistance and by 3H-lactulose and 3H-mannitol flux measurements. Na+-glucose cotransport was quantified as phlorizin-sensitive short circuit current (Isc) and active ion secretion by baseline and bumetanide-sensitive Isc. RESULTS: Duodenal biopsies from asymptomatic HIV-infected patients were no different from controls, whereas biopsies from HIV-infected patients with diarrhoea showed a decrease in epithelial resistance from 21.2+/-1.9 to 12.9+/-1.3 omega cm2 (P<0.01). Concomitantly, mucosal-to-serosal lactulose flux increased from 0.29+/-0.02 to 0.40+/-0.03 micromol (hcm2) (P<0.01). Phlorizin-sensitive Isc indicating Na+-glucose cotransport, as well as baseline and bumetanide-sensitive Isc indicating active electrogenic chloride secretion were not different between the three groups. CONCLUSIONS: A miniaturized Ussing device was developed for electrophysiological investigations of duodenal forceps biopsies, which allowed characterization of active ion transport mechanisms and epithelial barrier function. Duodenum of HIV-infected patients with diarrhoea showed no evidence for active ion secretion or Na+-glucose malabsorption, but showed an impaired epithelial barrier function, which could contribute to diarrhoea by a leak flux mechanism.

Iron deficiency and intestinal malabsorption in HIV disease.

Children with human immunodeficiency virus (HIV) infection have a higher prevalence of intestinal malabsorption. Anemia is also a common feature in these children. The aims of this work were (a) to establish the prevalence of iron deficiency in HIV-infected children, (b) to test the hypothesis that iron deficiency is related to intestinal malabsorption, (c) to see whether it may contribute to anemia, and (d) to evaluate the sensitivity of oral iron load in the investigation of intestinal function. To accomplish these goals, 71 HIV-infected symptomatic children were enrolled. Iron serum values were determined before and after oral load with ferrous sulfate. The correlation between basal and post-load iron levels was evaluated by linear regression. Xylose level after oral load, fecal fat, and fecal alpha 1-antitrypsin concentration were also determined. Iron deficiency was detected in 48% of patients, and it was significantly associated with intestinal iron malabsorption. Sugar malabsorption, steatorrhea, and fecal protein loss were detected in 26, 36, and 17% of patients, respectively. Low hemoglobin levels were detected in 66% of patients. The majority of children with iron deficiency also had anemia. Preliminary data showed that oral iron administration was sufficient for raising hemoglobin in children with normal iron absorption, whereas parenteral administration was required in those with iron malabsorption. We conclude that (a) iron deficiency is a major feature of pediatric HIV infection, (b) it is related to intestinal malabsorption, and (c) it contributes to anemia. Finally, oral iron load is a sensitive test for investigating intestinal function.