M. Mady Ndiaye resides in Cité des Enseignants Mermoz and currently serves as a Contractual Professor at Université Cheikh Anta Diop de Dakar, having attained the rank of full professor emeritus. He brings extensive experience and expertise in his field, contributing significantly to academia throughout his distinguished career.
Expérience professionnelle :
Diplômes :
Production scientifique
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Introduction: The misuse and misprescription of antibiotic medications in humans and animals are very often the causes of resistance acquired by bacteria such as Escherichia coli. Some strains of this species of the Enterobacteriaceae family are currently developing, at the global level, an increased resistance to several families of antibiotics, hence the need to carry out very frequent surveillance studies of these resistances at the national level.
Material and methods - Fifty-one (51) strains of E. coli from the Bacteriology-Virology Laboratory of the National University Hospital of Fann and isolated between January 1 and February 28, 2023, are the subject of this study.
The pathological products from which these strains have been isolated are: urine, blood, pus, and vaginal and urethral swabs. These strains were isolated based on the morphological, biochemical and cultural characteristics of Escherichia coli.
The antibiogram was performed with the agar diffusion technique according to the recommendations of the CA-SFM (Antibiogram Committee of the French Society of Microbiology).
Results
The antibiogram of Beta-lactam shows very high resistance to amoxicillin (84.31%), ticarcillin (87.50%) and amoxicillin/clavulanic acid (64.71%).
Cephalosporins, in particular cefotaxime and cefepime, have resistance of 50% and 54.90%, respectively.
51.11% of the E. coli strains in the study are resistant to aztreonam, unlike imipenema and ertapeneme, for which only 3.13% and 11.76% of the strains show resistance (Table 1).
6.12% of the strains are resistant to amikacin, 55.10% and 62.07% to levofloxacin and norfloxacin, respectively (Table 2).
Table1: Resistance of isolated strains to beta-lactam
Antibiotic |
Number of strains tested |
Critical values |
Number of resistant strains |
Percentage of resistant strains
|
Amoxicilline |
51 |
19 |
43 |
84,31% |
Amoxicilline / Acide clavulanique |
51 |
19 |
33 |
64,71% |
Ticarcilline |
48 |
20-23 |
42 |
87,50% |
Ticarcilline / acid clavulanique |
49 |
20-23 |
40 |
81,63% |
Céfépime |
51 |
24-27 |
28 |
54,90% |
Céfotaxime |
24 |
17-20 |
12 |
50,00% |
Aztréonam |
45 |
28 |
23 |
51,11% |
imipénéme |
32 |
19-50 |
1 |
3,13% |
Ertapénéme |
51 |
25 |
6 |
11,76% |
Table 2: Resistance of strains to aminoglycosides (quinolones and others)
Antibiotics |
Number of strains tested |
Critical values |
Number of resistant strains |
Percentage of resistant strains
|
Amikacine |
49 |
18 |
3 |
6,12% |
Tobramicine |
50 |
16 |
8 |
16,00% |
Acide nalidixique |
45 |
14 |
15 |
33,33% |
Lévofloxacine |
49 |
19-23 |
27 |
55,10% |
Norfloxacine |
29 |
22 |
18 |
62,07% |
Colistine |
47 |
16 |
0 |
0% |
Cotrimoxazole |
29 |
11-14 |
23 |
79,31% |
Fosfomycine |
49 |
21 |
5 |
10,20% |
Discussion: The study shows that 33.33% of the samples come from the neurology department, 19.05% from the thoracic and cardiovascular surgery department (CTCV) and 14.29% from the infectious and tropical diseases department (MIT).
The results for the neurology and CTCV departments could be explained by an aggravation of infections such as sepsis and by the vulnerability of patients (often immunocompromised) to the infectious and tropical diseases department.
62.75% of the E. coli strains in the study are isolated from urine. This result, similar to several national and international studies, places E. coli as the major species responsible for urinary tract infections in Senegal and worldwide. The high rates of resistance obtained with the help of antibiograms carried out on our E. coli strains show a circulation of ESBL E. coli strains at the community level.
Conclusion: The study reveals a circulation of ESBL E. coli strain at the community level. Thus, much more advanced molecular studies should be carried out to verify the circulation of these multidrug-resistant strains in the country's hospitals, which could, in this case, be the cause of nosocomial infections that not only require complicated therapeutic management but also participate in the spread of antibiotic-resistant bacteria.
Keywords: E. coli resistance to antibiotics, Senegal