Myeloperoxidase as a biomarker for intestinal-brain axis dysfunction induced by malnutrition and Cryptosporidium infection in weanling mice.

Cryptosporidiosis is a waterborne protozoal infection that may cause life-threatening diarrhea in undernourished children living in unsanitary environments. The aim of this study is to identify new biomarkers that may be related to gut-brain axis dysfunction in children suffering from the malnutrition/infection vicious cycle, necessary for better intervention strategies. Myeloperoxidase (MPO) is a well-known neutrophil-related tissue factor released during enteropathy that could drive gut-derived brain inflammation. We utilized a model of environmental enteropathy in C57BL/6 weanling mice challenged by Cryptosporidium and undernutrition. Mice were fed a 2%-Protein Diet (dPD) for eight days and orally infected with 107-C. parvum oocysts. C. parvum oocyst shedding was assessed from fecal and ileal-extracted genomic DNA by qRT-PCR. Ileal histopathology scores were assessed for intestinal inflammation. Prefrontal cortex samples were snap-frozen for MPO ELISA assay and NF-kb immunostaining. Blood samples were drawn by cardiac puncture after anesthesia and sera were obtained for serum amyloid A (SAA) and MPO analysis. Brain samples were also obtained for Iba-1 prefrontal cortex immunostaining. C. parvum-infected mice showed sustained stool oocyst shedding for six days post-infection and increased fecal MPO and inflammation scores. dPD and cryptosporidiosis led to impaired growth and weight gain. C. parvum-infected dPD mice showed increased serum MPO and serum amyloid A (SAA) levels, markers of systemic inflammation. dPD-infected mice showed greater MPO, NF-kB expression, and Iba-1 immunolabeling in the prefrontal cortex, an important brain region involved in executive function. Our findings suggest MPO as a potential biomarker for intestinal-brain axis dysfunction due to environmental enteropathy.

Myeloperoxidase as a biomarker for intestinal-brain axis dysfunction induced by malnutrition and Cryptosporidium infection in weanling mice

Abstract Cryptosporidiosis is a waterborne protozoal infection that may cause life-threatening diarrhea in undernourished children living in unsanitary environments. The aim of this study is to identify new biomarkers that may be related to gut-brain axis dysfunction in children suffering from the malnutrition/infection vicious cycle is necessary for better intervention strategies. Myeloperoxidase (MPO) is a well-known neutrophil-related tissue factor released during enteropathy that could drive gut-derived brain inflammation. We utilized a model of environmental enteropathy in C57BL/6 weanling mice challenged by Cryptosporidium and undernutrition. Mice were fed a 2%-Protein Diet (dPD) for eight days and orally infected with 107-C. parvum oocysts. C. parvum oocyst shedding was assessed from fecal and ileal-extracted genomic DNA by qRT-PCR. Ileal histopathology scores were assessed for intestinal inflammation. Prefrontal cortex samples were snap-frozen for MPO ELISA assay and NF-kb immunostaining. Blood samples were drawn by cardiac puncture after anesthesia and sera were obtained for serum amyloid A (SAA) and MPO analysis. Brain samples were also obtained for Iba-1 prefrontal cortex immunostaining. C. parvum-infected mice showed sustained stool oocyst shedding for six days post-infection and increased fecal MPO and inflammation scores. dPD and cryptosporidiosis led to impaired growth and weight gain. C. parvum-infected dPD mice showed increased serum MPO and serum amyloid A (SAA) levels, markers of systemic inflammation. dPD-infected mice showed greater MPO, NF-kB expression, and Iba-1 immunolabeling in the prefrontal cortex, an important brain region involved in executive function. Our findings suggest MPO as a potential biomarker for intestinal-brain axis dysfunction due to environmental enteropathy.

Virulence-Related Genes and Coenteropathogens Associated with Clinical Outcomes of Enteropathogenic Escherichia coli Infections in Children from the Brazilian Semiarid Region: a Case-Control Study of Diarrhea.

Enteropathogenic Escherichia coli (EPEC) is a major cause of diarrhea in children from developing countries and presents high genetic variability. We aimed to characterize the EPEC virulence-related gene (VRG) distribution and copathogens associated with diarrhea and nutrition-related outcomes in children from the low-income Brazilian semiarid region. A cross-sectional case-control study of diarrhea was conducted in 1,191 children aged 2 to 36 months from the northeast region of Brazil. Stool samples were collected and clinical, epidemiological, and anthropometric data were identified from each child. A broad molecular evaluation of enteropathogens was performed, and EPEC-positive samples were further investigated for 18 VRGs using five multiplex PCRs. EPEC was detected in 28.2% of the study population, with similar proportions among cases and controls. Typical EPEC (tEPEC) infections were more often associated with diarrhea than atypical EPEC (aEPEC) infections, while aEPEC infections presented a higher prevalence. The VRG ler, a negative regulator of the locus of enterocyte effacement, was associated with the absence of diarrhea in aEPEC-positive children; espB, a major component of the type 3 secretion system, was associated with diarrhea in tEPEC-positive children; the presence of procolonization VRGs-the combination of cesT positivity, espP negativity, and the presence of the map gene-was associated with undernutrition; and Campylobacter spp., norovirus, and enteroaggregative E. coli (EAEC) coinfections were associated with increased clinical severity in EPEC-infected children. These data identified tEPEC strains associated with diarrhea and specific VRGs of EPEC (ler, espB, cesT, and map genes) and Campylobacter spp., norovirus, and EAEC to be major contributors to diarrhea and undernutrition in children from a low-income Brazilian region.

Modulation of Intestinal Immune and Barrier Functions by Vitamin A: Implications for Current Understanding of Malnutrition and Enteric Infections in Children.

The micronutrient vitamin A refers to a group of compounds with pleiotropic effects on human health. These molecules can modulate biological functions, including development, vision, and regulation of the intestinal barrier. The consequences of vitamin A deficiency and supplementation in children from developing countries have been explored for several years. These children live in an environment that is highly contaminated by enteropathogens, which can, in turn, influence vitamin A status. Vitamin A has been described to modulate gene expression, differentiation and function of diverse immune cells; however, the underlying mechanisms are not fully elucidated. This review aims to summarize the most updated advances on elucidating the vitamin A effects targeting intestinal immune and barrier functions, which may help in further understanding the burdens of malnutrition and enteric infections in children. Specifically, by covering both clinical and in vivo/in vitro data, we describe the effects of vitamin A related to gut immune tolerance/homeostasis, intestinal barrier integrity, and responses to enteropathogens in the context of the environmental enteric dysfunction. Some of the gaps in the literature that require further research are also highlighted.

Molecular diagnosis of diarrheagenic Escherichia coli isolated from Psittaciformes of illegal wildlife trade / Diagnóstico molecular de Escherichia coli diarreiogênicas isoladas de Psittaciformes do tráfico ilegal de animais silvestres

Diarrheagenic Escherichia coli (DEC) are considered one of the major causes of human diarrhea in developing countries. Some studies have pointed wild birds as important reservoirs for these pathogens. However, scarce species from the Psittaciformes order have been investigated. This study aimed to evaluate the presence of DEC strains in Psittaciformes from illegal wildlife trade. A total of 78 E. coli strains isolated from cloacal swab samples of 167 Psittaciformes in the Ceará State, Brazil, were evaluated regarding the presence of the following DEC virulence genes by polymerase chain reaction (PCR): eaeA and bfpA genes (Enteropathogenic E. coli - EPEC); stx1 and stx2 (Shiga toxin-producing E. coli - STEC); estA and eltB (Enterotoxigenic E. coli - ETEC); ipaH (Enteroinvasive E. coli - EIEC); aatA and aaiC (Enteroaggregative E. coli - EAEC). Positive strains for eaeA and bfpA genes were considered typical EPEC, while strain positive exclusively for the eaeA gene were classified as atypical EPEC. The eaeA gene was identified in 20 E. coli strains and bfpA in 22 isolates. In addition, 11 and 9 belonged to tEPEC and aEPEC, respectively. No strain was positive for stx1 or stx2. A total of 47 (60.3%) strains and a total of 136 birds (81.4%) were negative for the remaining DEC pathotypes investigated. In conclusion, psittacine from illegal wildlife trade in Ceará State, Brazil, presented a relevant prevalence of typical and atypical EPEC, potentially playing a role as reservoirs of DEC strains in the environment. Thus, proper control measures must be adopted to block the spread of these pathogens.(AU)

Escherichia coli diarreiogênicas (DEC) são consideradas uma das causas mais importantes de diarreia em países em desenvolvimento. Alguns estudos têm apontado aves silvestres como importantes reservatórios destes patógenos, entretanto, poucas espécies da ordem Psittaciformes têm sido investigada. O objetivo deste estudo foi analisar a presença de cepas de E. coli diarreiogênicas em Psittaciformes do tráfico de animais silvestres. Um total de 78 amostras de E. coli isoladas de suabes cloacais provenientes de 167 de Psittaciformes do Ceará, Brasil, foram avaliadas quanto a presença dos seguintes genes de virulência DEC por meio de reação em cadeia de polimerase (PCR): eaeA e bfpA (E. coli Enteropatogênica - EPEC); stx1 e stx2 (E. coli produtora de Shiga - STEC); estA e eltB (E. coli Enterotoxigênica - ETEC); ipaH (E. coli Enteroinvasiva - EIEC); aatA e aaiC (E. coli Enteroagregativa - EAEC). As cepas positivas para os genes eaeA e bfpA foram consideradas EPEC típicas, enquanto que as positivas exclusivamente para o gene eaeA foram classificadas como EPEC atípicas. O gene eaeA foi identificado em 20 cepas de E. coli e o gene bfpA em 22 dos isolados. Adicionalmente, 11 e 9 cepas foram classificadas como EPEC típicas e atípicas, respectivamente. Nenhuma cepa foi positiva para os genes stx1 e stx2. Um total de 47 cepas (60,3%) e um total de 136 aves (81,4%) foram negativas para os demais patotipos DEC pesquisados. Em conclusão, psitacídeos provenientes do tráfico de aves silvestres do estado do Ceará, Brasil, apresentaram relevante prevalência de EPEC típicas e atípicas, potencialmente participando como reservatórios de cepas DEC no ambiente. Portanto, medidas de controle devem ser adotadas para inibir a disseminação destes patógenos.(AU)

Molecular diagnosis of diarrheagenic Escherichia coli isolated from Psittaciformes of illegal wildlife trade / Diagnóstico molecular de Escherichia coli diarreiogênicas isoladas de Psittaciformes do tráfico ilegal de animais silvestres

Diarrheagenic Escherichia coli (DEC) are considered one of the major causes of human diarrhea in developing countries. Some studies have pointed wild birds as important reservoirs for these pathogens. However, scarce species from the Psittaciformes order have been investigated. This study aimed to evaluate the presence of DEC strains in Psittaciformes from illegal wildlife trade. A total of 78 E. coli strains isolated from cloacal swab samples of 167 Psittaciformes in the Ceará State, Brazil, were evaluated regarding the presence of the following DEC virulence genes by polymerase chain reaction (PCR): eaeA and bfpA genes (Enteropathogenic E. coli - EPEC); stx1 and stx2 (Shiga toxin-producing E. coli - STEC); estA and eltB (Enterotoxigenic E. coli - ETEC); ipaH (Enteroinvasive E. coli - EIEC); aatA and aaiC (Enteroaggregative E. coli - EAEC). Positive strains for eaeA and bfpA genes were considered typical EPEC, while strain positive exclusively for the eaeA gene were classified as atypical EPEC. The eaeA gene was identified in 20 E. coli strains and bfpA in 22 isolates. In addition, 11 and 9 belonged to tEPEC and aEPEC, respectively. No strain was positive for stx1 or stx2. A total of 47 (60.3%) strains and a total of 136 birds (81.4%) were negative for the remaining DEC pathotypes investigated. In conclusion, psittacine from illegal wildlife trade in Ceará State, Brazil, presented a relevant prevalence of typical and atypical EPEC, potentially playing a role as reservoirs of DEC strains in the environment. Thus, proper control measures must be adopted to block the spread of these pathogens.(AU)

Escherichia coli diarreiogênicas (DEC) são consideradas uma das causas mais importantes de diarreia em países em desenvolvimento. Alguns estudos têm apontado aves silvestres como importantes reservatórios destes patógenos, entretanto, poucas espécies da ordem Psittaciformes têm sido investigada. O objetivo deste estudo foi analisar a presença de cepas de E. coli diarreiogênicas em Psittaciformes do tráfico de animais silvestres. Um total de 78 amostras de E. coli isoladas de suabes cloacais provenientes de 167 de Psittaciformes do Ceará, Brasil, foram avaliadas quanto a presença dos seguintes genes de virulência DEC por meio de reação em cadeia de polimerase (PCR): eaeA e bfpA (E. coli Enteropatogênica - EPEC); stx1 e stx2 (E. coli produtora de Shiga - STEC); estA e eltB (E. coli Enterotoxigênica - ETEC); ipaH (E. coli Enteroinvasiva - EIEC); aatA e aaiC (E. coli Enteroagregativa - EAEC). As cepas positivas para os genes eaeA e bfpA foram consideradas EPEC típicas, enquanto que as positivas exclusivamente para o gene eaeA foram classificadas como EPEC atípicas. O gene eaeA foi identificado em 20 cepas de E. coli e o gene bfpA em 22 dos isolados. Adicionalmente, 11 e 9 cepas foram classificadas como EPEC típicas e atípicas, respectivamente. Nenhuma cepa foi positiva para os genes stx1 e stx2. Um total de 47 cepas (60,3%) e um total de 136 aves (81,4%) foram negativas para os demais patotipos DEC pesquisados. Em conclusão, psitacídeos provenientes do tráfico de aves silvestres do estado do Ceará, Brasil, apresentaram relevante prevalência de EPEC típicas e atípicas, potencialmente participando como reservatórios de cepas DEC no ambiente. Portanto, medidas de controle devem ser adotadas para inibir a disseminação destes patógenos.(AU)

Molecular diagnosis of diarrheagenic Escherichia coli isolated from Psittaciformes of illegal wildlife trade

ABSTRACT: Diarrheagenic Escherichia coli (DEC) are considered one of the major causes of human diarrhea in developing countries. Some studies have pointed wild birds as important reservoirs for these pathogens. However, scarce species from the Psittaciformes order have been investigated. This study aimed to evaluate the presence of DEC strains in Psittaciformes from illegal wildlife trade. A total of 78 E. coli strains isolated from cloacal swab samples of 167 Psittaciformes in the Ceará State, Brazil, were evaluated regarding the presence of the following DEC virulence genes by polymerase chain reaction (PCR): eaeA and bfpA genes (Enteropathogenic E. coli - EPEC); stx1 and stx2 (Shiga toxin-producing E. coli - STEC); estA and eltB (Enterotoxigenic E. coli - ETEC); ipaH (Enteroinvasive E. coli - EIEC); aatA and aaiC (Enteroaggregative E. coli - EAEC). Positive strains for eaeA and bfpA genes were considered typical EPEC, while strain positive exclusively for the eaeA gene were classified as atypical EPEC. The eaeA gene was identified in 20 E. coli strains and bfpA in 22 isolates. In addition, 11 and 9 belonged to tEPEC and aEPEC, respectively. No strain was positive for stx1 or stx2. A total of 47 (60.3%) strains and a total of 136 birds (81.4%) were negative for the remaining DEC pathotypes investigated. In conclusion, psittacine from illegal wildlife trade in Ceará State, Brazil, presented a relevant prevalence of typical and atypical EPEC, potentially playing a role as reservoirs of DEC strains in the environment. Thus, proper control measures must be adopted to block the spread of these pathogens.

RESUMO: Escherichia coli diarreiogênicas (DEC) são consideradas uma das causas mais importantes de diarreia em países em desenvolvimento. Alguns estudos têm apontado aves silvestres como importantes reservatórios destes patógenos, entretanto, poucas espécies da ordem Psittaciformes têm sido investigada. O objetivo deste estudo foi analisar a presença de cepas de E. coli diarreiogênicas em Psittaciformes do tráfico de animais silvestres. Um total de 78 amostras de E. coli isoladas de suabes cloacais provenientes de 167 de Psittaciformes do Ceará, Brasil, foram avaliadas quanto a presença dos seguintes genes de virulência DEC por meio de reação em cadeia de polimerase (PCR): eaeA e bfpA (E. coli Enteropatogênica - EPEC); stx1 e stx2 (E. coli produtora de Shiga - STEC); estA e eltB (E. coli Enterotoxigênica - ETEC); ipaH (E. coli Enteroinvasiva - EIEC); aatA e aaiC (E. coli Enteroagregativa - EAEC). As cepas positivas para os genes eaeA e bfpA foram consideradas EPEC típicas, enquanto que as positivas exclusivamente para o gene eaeA foram classificadas como EPEC atípicas. O gene eaeA foi identificado em 20 cepas de E. coli e o gene bfpA em 22 dos isolados. Adicionalmente, 11 e 9 cepas foram classificadas como EPEC típicas e atípicas, respectivamente. Nenhuma cepa foi positiva para os genes stx1 e stx2. Um total de 47 cepas (60,3%) e um total de 136 aves (81,4%) foram negativas para os demais patotipos DEC pesquisados. Em conclusão, psitacídeos provenientes do tráfico de aves silvestres do estado do Ceará, Brasil, apresentaram relevante prevalência de EPEC típicas e atípicas, potencialmente participando como reservatórios de cepas DEC no ambiente. Portanto, medidas de controle devem ser adotadas para inibir a disseminação destes patógenos.