Antimicrobial resistance is a major public health concern worldwide affecting humans, animals and the environment. However, data is lacking especially in developing countries. Thus, the World Health Organization developed a One-Health surveillance project called Tricycle focusing on the prevalence of ESBL-producing Escherichia coli in humans, animals, and the environment. Here we present the first results of the human community component of Tricycle in Madagascar. From July 2018 to April 2019, rectal swabs from 492 pregnant women from Antananarivo, Mahajanga, Ambatondrazaka, and Toamasina were tested for ESBL-E. coli carriage. Demographic, sociological and environmental risk factors were investigated, and E. coli isolates were characterized (antibiotic susceptibility, resistance and virulence genes, plasmids, and genomic diversity). ESBL-E. coli prevalence carriage in pregnant women was 34% varying from 12% (Toamasina) to 65% (Ambatondrazaka). The main risk factor associated with ESBL-E. coli carriage was the rainy season (OR = 2.9, 95% CI 1.3–5.6, p = 0.009). Whole genome sequencing was performed on 168 isolates from 144 participants. blaCTX–M–15 was the most frequent ESBL gene (86%). One isolate was resistant to carbapenems and carried the blaNDM–5 gene. Most isolates belonged to commensalism associated phylogenetic groups A, B1, and C (90%) and marginally to extra-intestinal virulence associated phylogenetic groups B2, D and F (10%). Multi locus sequence typing showed 67 different sequence types gathered in 17 clonal complexes (STc), the most frequent being STc10/phylogroup A (35%), followed distantly by the emerging STc155/phylogroup B1 (7%), STc38/phylogroup D (4%) and STc131/phylogroup B2 (3%). While a wide diversity of clones has been observed, SNP analysis revealed several genetically close isolates (n = 34/168) which suggests human-to-human transmissions. IncY plasmids were found with an unusual prevalence (23%), all carrying a blaCTX–M–15. Most of them (85%) showed substantial homology (≥85%) suggesting a dissemination of IncY ESBL plasmids in Madagascar. This large-scale study reveals a high prevalence of ESBL-E. coli among pregnant women in four cities in Madagascar associated with warmth and rainfall. It shows the great diversity of E. coli disseminating throughout the country but also transmission of specific clones and spread of plasmids. This highlights the urgent need of public-health interventions to control antibiotic resistance in the country.

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In medical analysis laboratories, techniques for identifying bacteria are currently becoming more and more numerous. The objective of this study is to compare the 2 bacterial identification systems Bis NEG-D and Api 20E for the identification of gram-negative bacilli. This is a qualitative evaluation of the Bis NEG-D compared to the gold standard Api 20E. During the study period, 32 Gram-negative bacilli isolates were identified simultaneously using Api 20E and Bis NEG-D. The samples are represented by 12 (37.5%) blood samples for blood culture, 12 (37.5%) urine samples for cytobacteriological examination of the urine, 06 (18.8%) pus samples for bacteriological examination of pus, a sample of the cerebrospinal fluid (3.1%) and a vaginal sample (3.1%).The bacteria identified were represented by Enterobacter spp, Escherichia col,i Klebsiella pneumonia, Shigella spp, Salmonella typhi, Acinetobacter baumannii, Pseudomonas spp, Proteus mirabilis, Raoultella ornithinolytica and Bukholderia cepacia. This study showed a concordance of 90.6% (29/32) and a discordance of 9.4% (3/32) between the results of Api 20E and Bis NEG-D. Concerning the probability scores, they vary between 95% to 100% for Api 20E and between 79.3% to 100% for Bis NEG-D. This study also compared the pros and cons of using Api 20 E and Bis NEG-D. The Bis-NEG-D is valid and can be used by medical analysis laboratories like the Api 20E, especially if these laboratories do not need to perform a lot of bacterial identification tests.

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Background: Diarrheal diseases are a major public health problem in developing countries with high mortality and morbidity rates, especially among children. Shigella species is the leading cause of paediatric bacterial diarrhea and shigellosis data are very scarce in Madagascar.Methods: A 3 year retrospective study from January 2018 to December 2020, at the University Hospital Mother and Child Tsaralalàna laboratory was performed to assess the bacteriological and epidemiological characteristics of laboratory confirmed shigellosis cases.Results: During the study period, 298 stool samples were examined, of which 48 (16.1%) were positive for Shigella sp. The mean age of infected children was 29.7 months, predominantly in the 24-59 months age group. The infection was found mainly in male children (56.2%). Most isolates of Shigella sp showed resistance to co-trimoxazole and amoxicillin. All the strains were susceptible to third-generation cephalosporins. Of the isolated Shigella sp, 14 strains were tested for species identification and serotyping, twelve of which were Shigella flexneri and two were Shigella sonnei. The most frequent serotypes were S. flexneri 1b and 2a.Conclusions: This study found a Shigella sp positivity rate of 16.1%. This pathogen frequently infects infants age group. Bacteriology laboratory surveillance and a multicenter survey are essential to control the spread of drug-resistant Shigella and to monitor circulating strains and the burden of this disease. Awareness of water, hygiene and sanitation (WASH) and community water supply is also necessary to reduce this infection.