Increasing numbers of antibiotic-resistant Enterobacteriaceae are responsible of serious problems in infection control. This phenomenon also contributes to the global spread of Carbapenemase- producing bacteria becoming therefore especially worrisome . It has been shown that Enterobacterales spp., such as Escherichia coli and Klebsiella pneumoniae, are common human pathogens and asymptomatic colonizers of the human gastrointestinal tract and environmental niches . Our study reported for the first time the occurrence of Carbapenemase-producing E. coli and Salmonella in children with diarrhea in rural settings of Burkina Faso.
The isolated strains were mainly resistant to amoxicillin-clavulanic acid, amoxicillin, tetracycline, trimetoprim-sulfametoxazol, colistin-sulfate, piperacillin, cefotaxime, ceftriaxone, aztreonam, cefixime and cefepime (between 60% and 100%). Particularly, two E. coli harbored resistance patterns to imipenem. In contrast, no resistance to imipenem was observed in Salmonella strains. Similar results concerning E. coli resistance to imipenem were reported in India . All isolated E. coli and Salmonella were 100% sensitive to netilmicin in agreement with data reported in Bangladesh .
In the present study, the most detected carbapenemase was blaOXA which was encoded by eight of the isolates (57.14%). In agreement to our result, a recent review showed that OXA-48-like enzymes associated with Enterobacteriaceae are one of the most concerning developments in carbapenem resistance in the last decade and are still globally ascending . blaCTX−M gene was shown in one E. coli strain while blaTEM and blaSHV were reported in none of the strains. Unlike our results, studies conducted in India reported a high prevalence of CTX‑M‑type ESBL among ESBL‑E. coli isolated from clinical specimens [24, 25]. Interestingly, the strain encoding blaCTX−M gene in our study also harbored blaOXA gene. Indeed, enteric Gram-negative bacteria with the blaOXA-48-like genes could co-harbor genes encoding ESBL (blaCTX−M, blaSHV, blaTEM) . blaKPC2, blaVIM and blaIMP−2 were carried by two E. coli isolates while no Salmonella strains harboured these genes. Similarly, a recent study reported no blaKPC, blaVIM and blaIMP genes on carbapenemase producing Salmonella enterica isolates in the United Kingdom but reported 2 blaOXA48 strains and one blaNDM on the same isolates . This is expected because carbapenemase-producing Salmonella strains are rarely isolated. In contrast, resistance to carbapenems was observed in CIP-R Salmonella KentuckyX1-ST198-SGI1 isolates in which carbapenemases blaVIM − 2 and blaOXA − 48 have been detected .
Our results show that carbapenemase-producing Enterobacterales (CPE) remain one of the most urgent healthcare threats. Indeed, carbapenemase-encoding genes are already widespread in many parts of the world . A recent study on wastewater used for urban agriculture in Ouagadougou (Burkina Faso) concluded that raw sewage used as fertilizer could be contributing to the spread of resistance bacteria among humans and animals . Furthermore, a study has shown that bacteria producing carbapenemase are currently spreading among pets  and because of the proximity between humans and animals, these bacteria can contaminate humans. For example, it has been shown that poultry flocks contribute to the global dissemination of Salmonella Kentucky ST198-X1-SGI1CIP-R strain in developing countries . Since subsistence, farming and animal husbandry are the primary economic activities for the local populations in Boromo and Gourcy, the spread of these bacteria poses serious health concerns.
Three specific genes were detected in two E. coli strains: Klebsiella pneumoniae carbapenemase (KPC), Verona integrin-encoded metallo-β-lactamase (VIM) and Imipenemase (IMP-2). To our best of knowledge, this is the first report of blaKPC gene in E. coli in Burkina Faso. However, KPC producers have been described, mostly from nosocomial K. pneumoniae isolates, and E. coli strains in Israel but also from other enterobacterial species . Indeed, since their identification the first time in the USA in 1996, Klebsiella pneumoniae carbapenemases (KPCs) have spread internationally among Gram-negative bacteria, especially K. pneumoniae, although their precise epidemiology is diverse across countries and regions worldwide . Furthermore, because of its extensively identification worldwide, K. pneumoniae may have contributed to the spread of the blaKPC genes .
As far as the class B metallo-β-lactamases (MBLs) is concerned, our results corroborate the existing reports. Endemicity of VIM- and IMP-type enzymes has been reported in Greece, Taiwan and Japan [33, 8], although outbreaks and single reports of VIM and IMP producers have been shown in many other countries .
It has been shown that carbapenemases can hydrolyze almost all β-lactams, and are easily transferable among enterobacterial species . These genes are found in multidrug-resistant isolates consistent with the result found in the present study . Therefore, its spread in Enterobacteriaceae is a public health issue. For example, invasive infections by carbapenem-resistant strains have been found to be associated with high morbidity and mortality rates .
Otherwise, several risk factors of colonization and infection with carbapenemase-producing Enterobacterales (CPE) including severe underlying illness, prolonged hospital stay, the presence of invasive medical devices, and antibiotic use have been shown [36–39]. According to previous studies, CPE have been associated with adverse clinical and economic outcomes such as increased mortality, increased length of stay, setting up an effective therapy scheme, decreased functional status on discharge, and increased cost of health care [40–43]. Young children (those under one year old) were severely infected with carbapenem-resistant E. coli. This is a matter of public health issues because the emergence of MBL-producing bacteria greatly limits treatment options . The most frequent MBLs reported to date belong to the VIM and IMP types and have been described extensively worldwide .
The main limitation of the present study consists of the low number of isolates which makes generalizability difficult. Morever, the use of phenotypic approach limited to imipenem MIC is not adapted for the detection of all carbapenemase type. For instance, enterobacteria strains carrying blaOXA48 carbapenemase could present low imipenem MIC (0.5 mg/L) suggesting the use of temocillin for phenotypic detection of blaOXA48 .