Browsing by Author "Mummed B"

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    Determinants of Campylobacter species diversity in infants and association with family members, livestock, and household environments in rural Eastern Ethiopia
    (BioMed Central Ltd, 2025-12-01) Ojeda A; Deblais L; Mummed B; Brhane M; Hassen KA; Ahmedo BU; Weldesenbet YD; Chen D; Li X; Saleem C; Manary MJ; Roesch LFW; McKune SL; Havelaar AH; Rajashekara G; CAGED Research Team
    Background: Campylobacter infections pose a significant challenge in low- and middle-income countries, contributing to child mortality. Campylobacter is linked to acute gastrointestinal illness and severe long-term consequences, including environmental enteric dysfunction (EED) and stunting. In 2018, our cross-sectional study in Ethiopia detected Campylobacter in 88% of stools from children aged 12–15 months, with an average of 11 species per stool using meta-total RNA sequencing. Building on these findings, we conducted a longitudinal study (December 2020–June 2022) to investigate Campylobacter colonization of infants and identify reservoirs and risk factors in rural eastern Ethiopia. Results: After a preliminary screening of 15 Campylobacter species using species-specific quantitative PCR, we analyzed four target species in 2045 samples from infants (first month to just one year of life) and biannual samples from mothers, siblings, and livestock (goats, cattle, sheep, and chickens). Candidatus C. infans (41%), C. jejuni (26%), and C. upsaliensis (13%) were identified as the predominant in the infant gut. Colonization of C. infans and C.jejuni increased (C. infans: 0.85%, C. jejuni-0.98% increase/ day in the odds of colonization) and abundance (P = 0.027, 0.024) with age. Enteric symptoms were strongly associated with C. infans (diarrhea: OR = 2.02 [95%CI: 35%,100%]; fever: OR = 1.62 [95%CI: 14%, 83%]) and C. jejuni (diarrhea: OR = 2.29 [95%CI: 46%,100%], fever: OR = 2.53 [95%CI: 56%,100%]). Based on linear mixed models, we found elevated cumulative loads of C. infans load in infants (especially females OR = 1.5 [95%CI: 10%, 67%]), consuming raw milk (OR = 2.3 [95%CI: 24%,100%]) or those exposed to areas contaminated with animal droppings (OR = 1.6 [95%CI: 7%,93%]), while C. jejuni cumulative loads were higher in infants ingesting soil or animal feces (OR = 2.2 [95%CI: 23%,100%]). C. infans was also prevalent in siblings (56%) and mothers (45%), whereas C. jejuni was common in chickens (38%) and small ruminants (goats 27%, sheep 21%). Conclusions: Campylobacter was highly prevalent in rural Ethiopian infants. C. infans was primarily associated with human hosts, and C. jejuni was mainly linked to zoonotic sources. Our findings emphasize the need for targeted interventions addressing environmental, dietary, and behavioral factors to reduce Campylobacter transmission in resource-limited settings.
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    Prevalence and Load of the Campylobacter Genus in Infants and Associated Household Contacts in Rural Eastern Ethiopia: a Longitudinal Study from the Campylobacter Genomics and Environmental Enteric Dysfunction (CAGED) Project
    (American Society for Microbiology, 2023-07-26) Deblais L; Ojeda A; Brhane M; Mummed B; Hassen KA; Ahmedo BU; Weldesenbet YD; Amin JK; Ahmed IA; Usmane IA; Yusuf EA; Seran AJ; Abrahim FI; Game HT; Mummed BA; Usmail MM; Umer KA; Dawid MM; Gebreyes W; French N; Hassen JY; Roba KT; Mohammed A; Yimer G; Saleem C; Chen D; Singh N; Manary MJ; McKune SL; Havelaar AH; Rajashekara G; Elkins CA
    In our previous cross-sectional study, multiple species of Campylobacter were detected (88%) in stool samples from children (12 to 14 months of age) in rural eastern Ethiopia. This study assessed the temporal fecal carriage of Campylobacter in infants and identified putative reservoirs associated with these infections in infants from the same region. The prevalence and load of Campylobacter were determined using genus-specific real-time PCR. Stool samples from 106 infants (n = 1,073) were collected monthly from birth until 376 days of age (DOA). Human stool samples (mothers and siblings), livestock feces (cattle, chickens, goats, and sheep), and environmental samples (soil and drinking water) from the 106 households were collected twice per household (n = 1,644). Campylobacter was most prevalent in livestock feces (goats, 99%; sheep, 98%; cattle, 99%; chickens, 93%), followed by human stool samples (siblings, 91%; mothers, 83%; infants, 64%) and environmental samples (soil, 58%; drinking water, 43%). The prevalence of Campylobacter in infant stool samples significantly increased with age, from 30% at 27 DOA to 89% at 360 DOA (1% increase/day in the odds of being colonized) (P < 0.001). The Campylobacter load increased linearly (P < 0.001) with age from 2.95 logs at 25 DOA to 4.13 logs at 360 DOA. Within a household, the Campylobacter load in infant stool samples was positively correlated with the load in mother stool samples (r2 = 0.18) and soil collected inside the house (r2 = 0.36), which were in turn both correlated with Campylobacter loads in chicken and cattle feces (0.60 < r2 < 0.63) (P < 0.01). In conclusion, a high proportion of infants are infected with Campylobacter in eastern Ethiopia, and contact with the mother and contaminated soil may be associated with early infections. IMPORTANCE A high Campylobacter prevalence during early childhood has been associated with environmental enteric dysfunction (EED) and stunting, especially in low-resource settings. Our previous study demonstrated that Campylobacter was frequently found (88%) in children from eastern Ethiopia; however, little is known about potential Campylobacter reservoirs and transmission pathways leading to infection of infants by Campylobacter during early growth. In the longitudinal study presented here, Campylobacter was frequently detected in infants within the 106 surveyed households from eastern Ethiopia, and the prevalence was age dependent. Furthermore, preliminary analyses highlighted the potential role of the mother, soil, and livestock in the transmission of Campylobacter to the infant. Further work will explore the species and genetic composition of Campylobacter in infants and putative reservoirs using PCR and whole-genome and metagenomic sequencing. The findings from these studies can lead to the development of interventions to minimize the risk of transmission of Campylobacter to infants and, potentially, EED and stunting.
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    Unravelling the reservoirs for colonisation of infants with Campylobacter spp. in rural Ethiopia: protocol for a longitudinal study during a global pandemic and political tensions.
    (BMJ Publishing Group Ltd, 2022-10-05) Havelaar AH; Brhane M; Ahmed IA; Kedir J; Chen D; Deblais L; French N; Gebreyes WA; Hassen JY; Li X; Manary MJ; Mekuria Z; Ibrahim AM; Mummed B; Ojeda A; Rajashekara G; Roba KT; Saleem C; Singh N; Usmane IA; Yang Y; Yimer G; McKune S
    INTRODUCTION: Undernutrition is an underlying cause of mortality in children under five (CU5) years of age. Animal-source foods have been shown to decrease malnutrition in CU5. Livestock are important reservoirs for Campylobacter bacteria, which are recognised as risk factors for child malnutrition. Increasing livestock production may be beneficial for improving nutrition of children but these benefits may be negated by increased exposure to Campylobacter and research is needed to evaluate the complex pathways of Campylobacter exposure and infection applicable to low-income and middle-income countries. We aim to identify reservoirs of infection with Campylobacter spp. of infants in rural Eastern Ethiopia and evaluate interactions with child health (environmental enteric dysfunction and stunting) in the context of their sociodemographic environment. METHODS AND ANALYSIS: This longitudinal study involves 115 infants who are followed from birth to 12 months of age and are selected randomly from 10 kebeles of Haramaya woreda, East Hararghe zone, Oromia region, Ethiopia. Questionnaire-based information is obtained on demographics, livelihoods, wealth, health, nutrition and women empowerment; animal ownership/management and diseases; and water, sanitation and hygiene. Faecal samples are collected from infants, mothers, siblings and livestock, drinking water and soil. These samples are analysed by a range of phenotypic and genotypic microbiological methods to characterise the genetic structure of the Campylobacter population in each of these reservoirs, which will support inference about the main sources of exposure for infants. ETHICS AND DISSEMINATION: Ethical approval was obtained from the University of Florida Internal Review Board (IRB201903141), the Haramaya University Institutional Health Research Ethics Committee (COHMS/1010/3796/20) and the Ethiopia National Research Ethics Review Committee (SM/14.1/1059/20). Written informed consent is obtained from all participating households. Research findings will be disseminated to stakeholders through conferences and peer-reviewed journals and through the Feed the Future Innovation Lab for Livestock Systems.