Gut carriage of antimicrobial resistance genes among young children in urban Maputo, Mozambique: Associations with enteric pathogen carriage and environmental risk factors

Abstract

Because poor sanitation is hypothesized as a major direct and indirect pathway of exposure to antimicrobial resistance genes (ARGs), we sought to determine a) the prevalence of and b) environmental risk factors for gut carriage of key ARGs in a pediatric cohort at high risk of enteric infections due to poor water, sanitation, and hygiene (WASH) conditions. We investigated ARGs in stool from young children in crowded, low-income settlements of Maputo, Mozambique, and explored potential associations with concurrent enteric pathogen carriage, diarrhea, and environmental risk factors, including WASH. We collected stool from 120 children <14 months old and tested specimens via quantal, multiplex molecular assays for common bacterial, viral, and protozoan enteric pathogens and 84 ARGs encoding potential resistance to 7 antibiotic classes. We estimated associations between ARG detection (number and diversity detected) and concurrently-measured enteric pathogen carriage, recently-reported diarrhea, and risk factors in the child’s living environment. The most commonly-detected ARGs encoded resistance to macrolides, lincosamides, and streptogramins (100% of children); tetracyclines (98%); β-lactams (94%), aminoglycosides (84%); fluoroquinolones (48%); and vancomycin (38%). Neither concurrent diarrhea nor measured environmental (including WASH) conditions were associated with ARG detection in adjusted models. Enteric pathogen carriage and ARG detection were associated: on average, 18% more ARGs were detected in stool from children carrying bacterial pathogens than those without (adjusted risk ratio (RR): 1.18, 95% confidence interval (CI): 1.02, 1.37), with 16% fewer ARGs detected in children carrying parasitic pathogens (protozoans, adjusted RR: 0.84, 95% CI: 0.71, 0.99). We observed gut ARGs conferring potential resistance to a range of antibiotics in this at-risk cohort that had high rates of enteric infection, even among children <14 months-old. Gut ARGs did not appear closely correlated with WASH, though environmental conditions were generally poor. ARG carriage may be associated with concurrent carriage of bacterial enteric pathogens, suggesting indirect linkages to WASH that merit further investigation.

Characterization of Escherichia coli from Water and Food Sold on the Streets of Maputo: Molecular Typing, Virulence Genes, and Antibiotic Resistance

“…It was not possible to establish a relationship between the origin of the isolates (food or water) or the municipal district where they were sold, confirming the high diversity of fecal contamination sources of food and water sold on the streets, as previously reported [1,20]. In fact, Maputo municipal districts are non-urbanized areas, with numerous sanitation problems and water supply difficulties, contributing to the spread of pathogenic microorganisms [5,15,32]. In some cases, isolates gathered in clusters with a high level of similarity (>85%), presenting different virulence genes or different antibiotic resistance profiles, which suggests that the isolates may have had the same clonal origin but evolved in different environments where different genes were acquired, depending on adaptive mutations to cope with lethal stresses [33].…”

“…The sale of RTE street food, despite representing an important source of income for many unemployed families, has often been associated with outbreaks of diarrheal diseases [15]. In Maputo, Mozambique, these foods are often exposed to dust and sold without temperature control and minimum hygiene conditions.…”

High Fecal Contamination and High Levels of Antibiotic-Resistant Enterobacteriaceae in Water Consumed in the City of Maputo, Mozambique

“…The tap water samples showed a level of microbiological contamination higher than that recommended for human consumption ( Table 3 ). Of the samples, 92% and 96% contained aerobic mesophiles at 22 and 37 °C, respectively, that were greater than 2 log CFU/mL and classified as unsatisfactory according to the European Council Directive 98/83/CE [ 24 ]. Regarding fecal enterococci, 68% of the samples presented values greater than 1.9 log CFU/100 mL ( Table 3 ).…”

“…Regarding fecal enterococci, 68% of the samples presented values greater than 1.9 log CFU/100 mL ( Table 3 ). Fecal coliforms and E. coli were found in 64 and 28% of the water samples, respectively ( Table 3 ), and were classified as unsatisfactory according to the European Council Directive 98/83/CE [ 24 ], WHO guidelines [ 44 ], and Mozambican directives [ 39 ].…”

“…This increases the pressure on the already deficient health system or makes patients turn to informal markets for the sale of antibiotics, which has been increasing in many countries [ 17 , 20 , 21 ]. However, local studies report that due to the pressure exerted on hospitals, the treatments given to these cases are carried out empirically, which can lead to inappropriate antibiotic consumption [ 22 , 23 , 24 , 25 ]. Therefore, this study was carried out to determine the microbiological quality of water sold on the streets of Maputo, Mozambique, and to evaluate the antibiotic resistance profile of Enterobacteriaceae isolates collected from these waters.…”