Conference abstract
Study of Resistance mechanisms, virulence factors and performance diagnosis of some tests on clinical strains of Pseudomonas aeruginosa in the Center region of Cameroon
Pan African Medical Journal - Conference Proceedings. 2023:18(111).03
Oct 2023.
doi: 10.11604/pamj-cp.2023.18.111.2219
Archived on: 03 Oct 2023
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Keywords: Resistance mechanisms, biofilm, performance, virulence
Oral presentation
Study of Resistance mechanisms, virulence factors and performance diagnosis of some tests on clinical strains of Pseudomonas aeruginosa in the Center region of Cameroon
Yves Le Grand Napa Tchuedji1,&, Hortense Gonsu Kamga1, Yap Boum II1, Emilia Lyonga Mbamyah1, Minone Rosanne Ngome2, Francois-Xavier Etoa1
1Department of Microbiology, Laboratory of Microbiology, University of Yaoundé I, Yaoundé, Cameroon, 2Centre Pasteur du Cameroun, Yaoundé, Cameroon
&Corresponding author
Introduction: Pseudomonas aeruginosa belongs to the six leading pathogens for deaths associated with resistance. Despite the emergence of MDR, XDR and PDR Pseudomonas aeruginosa, a recent study conducted in 12 Cameroonian cities revealed that 88% of health personnel perform empirical antibiotic therapy and 47% have difficulty choosing the best antibiotic. The objective was to determine the resistance mechanisms, virulence factors, and performance diagnosis of some tests on Pseudomonas aeruginosa in the center region of Cameroon.
Methods: we conducted a descriptive cross-sectional study from May 2019 to November 2022. A systematic sampling was conducted. Susceptibility tests and carbapenemase test were carried out by the disc diffusion method and Extended-spectrum beta-lactamases (ESBLs) were identified by the double disc synergy test. Resistance genes and virulence genes were identified in Pseudomonas aeruginosa by PCR. The diagnostic performance of API 20 NE, tissue culture plate, and culture on Congo red agar was determined using PCR as a gold standard.
Results: a total of 30 clinical isolates of Pseudomonas aeruginosa were isolated from 300 participants and 73.3% were confirmed as Pseudomonas aeruginosa with PCR ( p = 0.0014). Among these strains, 77.27% harbored OXA-50, 13.63% harbored Bla CTXM while 81,82 % lost the OprD gene and 90,91% lost the Gyr A gene. The most expressed virulence genes in P. aeruginosa were exo S (86.36%), tox A (81.81%), and RhII (77.27%). TCP method demonstrated a high sensitivity (92.8%, 68.5-99.63) compared to Congo red agar method (23.5%, 9.6-47.2) but a low specificity of 50% (21.5-78.4) compared to Congo red agar method (100%, 51-100).
Conclusion: this study demonstrated many resistance mechanisms to second-line antibiotics, the low performance of API 20 NE, and the High performance of the TCP test. The results of this study will make it possible to propose antibiotic selection policies and treatment protocols for Pseudomonas aeruginosa infections adapted to the current epidemiology of resistance in health facilities in Cameroon.
Study of Resistance mechanisms, virulence factors and performance diagnosis of some tests on clinical strains of Pseudomonas aeruginosa in the Center region of Cameroon
Yves Le Grand Napa Tchuedji1,&, Hortense Gonsu Kamga1, Yap Boum II1, Emilia Lyonga Mbamyah1, Minone Rosanne Ngome2, Francois-Xavier Etoa1
1Department of Microbiology, Laboratory of Microbiology, University of Yaoundé I, Yaoundé, Cameroon, 2Centre Pasteur du Cameroun, Yaoundé, Cameroon
&Corresponding author
Introduction: Pseudomonas aeruginosa belongs to the six leading pathogens for deaths associated with resistance. Despite the emergence of MDR, XDR and PDR Pseudomonas aeruginosa, a recent study conducted in 12 Cameroonian cities revealed that 88% of health personnel perform empirical antibiotic therapy and 47% have difficulty choosing the best antibiotic. The objective was to determine the resistance mechanisms, virulence factors, and performance diagnosis of some tests on Pseudomonas aeruginosa in the center region of Cameroon.
Methods: we conducted a descriptive cross-sectional study from May 2019 to November 2022. A systematic sampling was conducted. Susceptibility tests and carbapenemase test were carried out by the disc diffusion method and Extended-spectrum beta-lactamases (ESBLs) were identified by the double disc synergy test. Resistance genes and virulence genes were identified in Pseudomonas aeruginosa by PCR. The diagnostic performance of API 20 NE, tissue culture plate, and culture on Congo red agar was determined using PCR as a gold standard.
Results: a total of 30 clinical isolates of Pseudomonas aeruginosa were isolated from 300 participants and 73.3% were confirmed as Pseudomonas aeruginosa with PCR ( p = 0.0014). Among these strains, 77.27% harbored OXA-50, 13.63% harbored Bla CTXM while 81,82 % lost the OprD gene and 90,91% lost the Gyr A gene. The most expressed virulence genes in P. aeruginosa were exo S (86.36%), tox A (81.81%), and RhII (77.27%). TCP method demonstrated a high sensitivity (92.8%, 68.5-99.63) compared to Congo red agar method (23.5%, 9.6-47.2) but a low specificity of 50% (21.5-78.4) compared to Congo red agar method (100%, 51-100).
Conclusion: this study demonstrated many resistance mechanisms to second-line antibiotics, the low performance of API 20 NE, and the High performance of the TCP test. The results of this study will make it possible to propose antibiotic selection policies and treatment protocols for Pseudomonas aeruginosa infections adapted to the current epidemiology of resistance in health facilities in Cameroon.
