@article {151, title = {High-throughput sequencing of pooled samples to determine community-level microbiome diversity.}, journal = {Ann Epidemiol}, volume = {39}, year = {2019}, month = {2019 11}, pages = {63-68}, abstract = {

PURPOSE: Community-level interventions in cluster randomized controlled trials may alter the gut microbiome of individuals. The current method of estimating community diversities uses microbiome data obtained from multiple individual{\textquoteright}s specimens. Here we propose randomly pooling a number of microbiome samples from the same community into one sample before sequencing to estimate community-level microbiome diversity.

METHODS: We design and analyze an experiment to compare community microbiome diversity (gamma-diversity) estimates derived from 16S rRNA gene sequencing of 1) individually sequenced specimens vs. 2) pooled specimens collected from a community. Pool sizes of 10, 20, and 40 are considered. We then compare the gamma-estimates using Pearson{\textquoteright}s correlation as well as using Bland and Altman agreement analysis for three established diversity indices including richness, Simpson{\textquoteright}s and Shannon{\textquoteright}s.

RESULTS: The gamma-diversity estimates are highly correlated, with most being statistically significant. All correlations between all three diversity estimates are significant in the 10-pooled data. Pools comprising 40 specimens are closest to the line of agreement, but all pooled samples and individual samples fall within the 95\% limits of agreement.

CONCLUSIONS: Pooling microbiome samples before DNA amplification and metagenomics sequencing to estimate community-level diversity is a viable measure to consider in population-level association research studies.

}, keywords = {Administration, Oral, Anti-Bacterial Agents, Azithromycin, Bacteria, Biodiversity, Child, Preschool, Female, Gastrointestinal Microbiome, Gastrointestinal Tract, High-Throughput Nucleotide Sequencing, Humans, Infant, Infant, Newborn, Male, Metagenomics, Microbiota, Niger, Placebos, RNA, Ribosomal, 16S, Sequence Analysis, DNA}, issn = {1873-2585}, doi = {10.1016/j.annepidem.2019.09.002}, author = {Ray, Kathryn J and Cotter, Sun Y and Arzika, Ahmed M and Kim, Jessica and Boubacar, Nameywa and Zhou, Zhaoxia and Zhong, Lina and Porco, Travis C and Keenan, Jeremy D and Lietman, Thomas M and Doan, Thuy} } @article {121, title = {Longer-Term Assessment of Azithromycin for Reducing Childhood Mortality in Africa.}, journal = {N Engl J Med}, volume = {380}, year = {2019}, month = {2019 Jun 06}, pages = {2207-2214}, abstract = {

BACKGROUND: The MORDOR I trial (Macrolides Oraux pour R{\'e}duire les D{\'e}c{\`e}s avec un Oeil sur la R{\'e}sistance) showed that in Niger, mass administration of azithromycin twice a year for 2 years resulted in 18\% lower postneonatal childhood mortality than administration of placebo. Whether this benefit could increase with each administration or wane owing to antibiotic resistance was unknown.

METHODS: In the Niger component of the MORDOR I trial, we randomly assigned 594 communities to four twice-yearly distributions of either azithromycin or placebo to children 1 to 59 months of age. In MORDOR II, all these communities received two additional open-label azithromycin distributions. All-cause mortality was assessed twice yearly by census workers who were unaware of participants{\textquoteright} original assignments.

RESULTS: In the MORDOR II trial, the mean ({\textpm}SD) azithromycin coverage was 91.3{\textpm}7.2\% in the communities that received twice-yearly azithromycin for the first time (i.e., had received placebo for 2 years in MORDOR I) and 92.0{\textpm}6.6\% in communities that received azithromycin for the third year (i.e., had received azithromycin for 2 years in MORDOR I). In MORDOR II, mortality was 24.0 per 1000 person-years (95\% confidence interval [CI], 22.1 to 26.3) in communities that had originally received placebo in the first year and 23.3 per 1000 person-years (95\% CI, 21.4 to 25.5) in those that had originally received azithromycin in the first year, with no significant difference between groups (P = 0.55). In communities that had originally received placebo, mortality decreased by 13.3\% (95\% CI, 5.8 to 20.2) when the communities received azithromycin (P = 0.007). In communities that had originally received azithromycin and continued receiving it for an additional year, the difference in mortality between the third year and the first 2 years was not significant (-3.6\%; 95\% CI, -12.3 to 4.5; P = 0.50).

CONCLUSIONS: We found no evidence that the effect of mass administration of azithromycin on childhood mortality in Niger waned in the third year of treatment. Childhood mortality decreased when communities that had originally received placebo received azithromycin. (Funded by the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT02047981.).

}, keywords = {Anti-Bacterial Agents, Azithromycin, Child Mortality, Child, Preschool, Drug Administration Schedule, Female, Humans, Infant, Infant Mortality, Male, Mass Drug Administration, Niger}, issn = {1533-4406}, doi = {10.1056/NEJMoa1817213}, author = {Keenan, Jeremy D and Arzika, Ahmed M and Maliki, Ramatou and Boubacar, Nameywa and Elh Adamou, Sanoussi and Moussa Ali, Maria and Cook, Catherine and Lebas, Elodie and Lin, Ying and Ray, Kathryn J and O{\textquoteright}Brien, Kieran S and Doan, Thuy and Oldenburg, Catherine E and Callahan, E Kelly and Emerson, Paul M and Porco, Travis C and Lietman, Thomas M} } @article {56, title = {Azithromycin to Reduce Childhood Mortality in Sub-Saharan Africa.}, journal = {N Engl J Med}, volume = {378}, year = {2018}, month = {2018 Apr 26}, pages = {1583-1592}, abstract = {

BACKGROUND: We hypothesized that mass distribution of a broad-spectrum antibiotic agent to preschool children would reduce mortality in areas of sub-Saharan Africa that are currently far from meeting the Sustainable Development Goals of the United Nations.

METHODS: In this cluster-randomized trial, we assigned communities in Malawi, Niger, and Tanzania to four twice-yearly mass distributions of either oral azithromycin (approximately 20 mg per kilogram of body weight) or placebo. Children 1 to 59 months of age were identified in twice-yearly censuses and were offered participation in the trial. Vital status was determined at subsequent censuses. The primary outcome was aggregate all-cause mortality; country-specific rates were assessed in prespecified subgroup analyses.

RESULTS: A total of 1533 communities underwent randomization, 190,238 children were identified in the census at baseline, and 323,302 person-years were monitored. The mean ({\textpm}SD) azithromycin and placebo coverage over the four twice-yearly distributions was 90.4{\textpm}10.4\%. The overall annual mortality rate was 14.6 deaths per 1000 person-years in communities that received azithromycin (9.1 in Malawi, 22.5 in Niger, and 5.4 in Tanzania) and 16.5 deaths per 1000 person-years in communities that received placebo (9.6 in Malawi, 27.5 in Niger, and 5.5 in Tanzania). Mortality was 13.5\% lower overall (95\% confidence interval [CI], 6.7 to 19.8) in communities that received azithromycin than in communities that received placebo (P\<0.001); the rate was 5.7\% lower in Malawi (95\% CI, -9.7 to 18.9), 18.1\% lower in Niger (95\% CI, 10.0 to 25.5), and 3.4\% lower in Tanzania (95\% CI, -21.2 to 23.0). Children in the age group of 1 to 5 months had the greatest effect from azithromycin (24.9\% lower mortality than that with placebo; 95\% CI, 10.6 to 37.0). Serious adverse events occurring within a week after administration of the trial drug or placebo were uncommon, and the rate did not differ significantly between the groups. Evaluation of selection for antibiotic resistance is ongoing.

CONCLUSIONS: Among postneonatal, preschool children in sub-Saharan Africa, childhood mortality was lower in communities randomly assigned to mass distribution of azithromycin than in those assigned to placebo, with the largest effect seen in Niger. Any implementation of a policy of mass distribution would need to strongly consider the potential effect of such a strategy on antibiotic resistance. (Funded by the Bill and Melinda Gates Foundation; MORDOR ClinicalTrials.gov number, NCT02047981 .).

}, keywords = {Administration, Oral, Anti-Bacterial Agents, Azithromycin, Child Mortality, Child, Preschool, Communicable Disease Control, Communicable Diseases, Drug Resistance, Bacterial, Female, Humans, Infant, Infant Mortality, Malawi, Male, Mass Drug Administration, Niger, Public Health, Tanzania}, issn = {1533-4406}, doi = {10.1056/NEJMoa1715474}, author = {Keenan, Jeremy D and Bailey, Robin L and West, Sheila K and Arzika, Ahmed M and Hart, John and Weaver, Jerusha and Kalua, Khumbo and Mrango, Zakayo and Ray, Kathryn J and Cook, Catherine and Lebas, Elodie and O{\textquoteright}Brien, Kieran S and Emerson, Paul M and Porco, Travis C and Lietman, Thomas M} } @article {261, title = {Effect of Commonly Used Pediatric Antibiotics on Gut Microbial Diversity in Preschool Children in Burkina Faso: A Randomized Clinical Trial.}, journal = {Open Forum Infect Dis}, volume = {5}, year = {2018}, month = {2018 Nov}, pages = {ofy289}, abstract = {

Background: Exposure to antibiotics may result in alterations to the composition of intestinal microbiota. However, few trials have been conducted, and observational studies are subject to confounding by indication. We conducted a randomized controlled trial to determine the effect of 3 commonly used pediatric antibiotics on the intestinal microbiome in healthy preschool children.

Methods: Children aged 6-59 months were randomized (1:1:1:1) to a 5-day course of 1 of 3 antibiotics, including amoxicillin (25 mg/kg/d twice-daily doses), azithromycin (10 mg/kg dose on day 1 and then 5 mg/kg once daily for 4 days), cotrimoxazole (240 mg once daily), or placebo. Rectal swabs were obtained at baseline and 5 days after the last dose and were processed using 16S rRNA gene sequencing. The prespecified primary outcome was inverse Simpson{\textquoteright}s α-diversity index.

Results: Post-treatment Simpson{\textquoteright}s diversity was significantly different across the 4 arms ( = .003). The mean Simpson{\textquoteright}s α-diversity among azithromycin-treated children was significantly lower than in placebo-treated children (6.6; 95\% confidence interval [CI], 5.5-7.8; vs 9.8; 95\% CI, 8.7-10.9; = .0001). Diversity in children treated with amoxicillin (8.3; 95\% CI, 7.0-9.6; = .09) or cotrimoxazole (8.3; 95\% CI, 8.2-9.7; = .08) was not significantly different than placebo.

Conclusions: Azithromycin affects the composition of the pediatric intestinal microbiome. The effect of amoxicillin and cotrimoxazole on microbiome composition was less clear.

Clinical Trials Registration: clinicaltrials.gov NCT03187834.

}, issn = {2328-8957}, doi = {10.1093/ofid/ofy289}, author = {Oldenburg, Catherine E and Sie, Ali and Coulibaly, Boubacar and Ouermi, Lucienne and Dah, Clarisse and Tapsoba, Charlemagne and B{\"a}rnighausen, Till and Ray, Kathryn J and Zhong, Lina and Cummings, Susie and Lebas, Elodie and Lietman, Thomas M and Keenan, Jeremy D and Doan, Thuy} } @article {221, title = {Mass Azithromycin Distribution and Community Microbiome: A Cluster-Randomized Trial.}, journal = {Open Forum Infect Dis}, volume = {5}, year = {2018}, month = {2018 Aug}, pages = {ofy182}, abstract = {

Background: Mass distributions of oral azithromycin have long been used to eliminate trachoma, and they are now being proposed to reduce childhood mortality. The observed benefit appears to be augmented with each additional treatment, suggesting a possible community-level effect. Here, we assess whether 2 biannual mass treatments of preschool children affect the community{\textquoteright}s gut microbiome at 6 months after the last distribution.

Methods: In this cluster-randomized controlled trial, children aged 1-60 months in the Dossa region of Niger were randomized at the village level to receive a single dose of azithromycin or placebo every 6 months. Fecal samples were collected 6 months after the second treatment for metagenomic deep sequencing. The prespecified primary outcome was the Euclidean PERMANOVA of the gut microbiome, or effectively the distance between the genus-level centroid at the community level, with the secondary outcome being the Simpson{\textquoteright}s α diversity.

Results: In the azithromycin arm, the gut microbial structures were significantly different than in the placebo arm (Euclidean PERMANOVA, \< .001). Further, the diversity of the gut microbiome in the azithromycin arm was significantly lower than in the placebo arm (inverse Simpson{\textquoteright}s index, = .005).

Conclusions: Two mass azithromycin administrations, 6 months apart, in preschool children led to long-term alterations of the gut microbiome structure and community diversity. Here, long-term microbial alterations in the community did not imply disease but were associated with an improvement in childhood mortality.

Clinical Trials Registration: NCT02048007.

}, issn = {2328-8957}, doi = {10.1093/ofid/ofy182}, author = {Doan, Thuy and Hinterwirth, Armin and Arzika, Ahmed M and Cotter, Sun Y and Ray, Kathryn J and O{\textquoteright}Brien, Kieran S and Zhong, Lina and Chow, Eric D and Zhou, Zhaoxia and Cummings, Susie L and Fry, Dionna and Oldenburg, Catherine E and Worden, Lee and Porco, Travis C and Keenan, Jeremy D and Lietman, Thomas M} } @article {276, title = {Gut Microbial Diversity in Antibiotic-Naive Children After Systemic Antibiotic Exposure: A Randomized Controlled Trial.}, journal = {Clin Infect Dis}, volume = {64}, year = {2017}, month = {2017 05 01}, pages = {1147-1153}, abstract = {

Background: Antibiotic exposure can alter the gut microbiome. We evaluate the effects of azithromycin on the gut microbiome diversity of children from an antibiotic-naive community in Niger.

Methods: A population-based sample of 80 children aged 1-60 months in the Dosso region of Niger was randomized to receive a single dose of either oral azithromycin or placebo. Fecal samples were collected immediately before treatment and 5 days after treatment for 16S rRNA gene sequencing. The prespecified outcome was α-diversity (inverse Simpson{\textquoteright}s α-diversity index), with secondary outcomes of β and γ Simpson{\textquoteright}s and Shannon{\textquoteright}s diversities.

Results: At 5 days after treatment, 40 children aged 1-60 months were analyzed in the azithromycin-treated group and 40 children in the placebo-treated group. Diversity of the gut microbiome was significantly lower in the treated group (inverse Simpson{\textquoteright}s α-diversity, 5.03; 95\% confidence interval [CI], 4.08-6.14) than in the placebo group (6.91; 95\% CI, 5.82-8.21; P = .03). Similarly, the Shannon{\textquoteright}s α-diversity was lower in the treated group (10.60; 95\% CI, 8.82-12.36) than the placebo group (15.42; 95\% CI, 13.24-17.80; P = .004). Simpson{\textquoteright}s community-level (γ) diversity decreased with azithromycin exposure from 17.72 (95\% CI, 13.80-20.21) to 10.10 (95\% CI, 7.80-11.40; P = .00008), although β-diversity was not significantly reduced (2.56, 95\% CI, 1.88-3.12; to 2.01, 95\% CI, 1.46-2.51; P = .26).

Conclusions: Oral administration of azithromycin definitively decreases the diversity of the gut microbiome of children in an antibiotic-naive community.

Clinical Trials Registration: NCT02048007.

}, keywords = {Administration, Oral, Anti-Bacterial Agents, Azithromycin, Bacteria, Biodiversity, Child, Preschool, Cluster Analysis, DNA, Ribosomal, Female, Gastrointestinal Microbiome, Gastrointestinal Tract, Humans, Infant, Male, Niger, Phylogeny, Placebos, RNA, Ribosomal, 16S, Sequence Analysis, DNA}, issn = {1537-6591}, doi = {10.1093/cid/cix141}, author = {Doan, Thuy and Arzika, Ahmed M and Ray, Kathryn J and Cotter, Sun Y and Kim, Jessica and Maliki, Ramatou and Zhong, Lina and Zhou, Zhaoxia and Porco, Travis C and Vanderschelden, Benjamin and Keenan, Jeremy D and Lietman, Thomas M} }