Phenotypic and genotypic characterization of linezolid resistance and the effect of antibiotic combinations on methicillin-resistant Staphylococcus aureus clinical isolates
Abstract Background Methicillin-Resistant Staphylococcus aureus (MRSA) causes life-threatening infections, with narrow therapeutic options including: vancomycin and linezolid. Accordingly, this study aimed to characterize phenotypically and genotypically, the most relevant means of linezolid resista...
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| Format: | Article |
| Language: | English |
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BMC
2023-04-01
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| Series: | Annals of Clinical Microbiology and Antimicrobials |
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| Online Access: | https://doi.org/10.1186/s12941-023-00574-2 |
| _version_ | 1827970564002676736 |
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| author | Asmaa I. AbdAlhafiz Nooran S. Elleboudy Khaled M. Aboshanab Mohammad M. Aboulwafa Nadia A. Hassouna |
| author_facet | Asmaa I. AbdAlhafiz Nooran S. Elleboudy Khaled M. Aboshanab Mohammad M. Aboulwafa Nadia A. Hassouna |
| author_sort | Asmaa I. AbdAlhafiz |
| collection | DOAJ |
| description | Abstract Background Methicillin-Resistant Staphylococcus aureus (MRSA) causes life-threatening infections, with narrow therapeutic options including: vancomycin and linezolid. Accordingly, this study aimed to characterize phenotypically and genotypically, the most relevant means of linezolid resistance among some MRSA clinical isolates. Methods A total of 159 methicillin-resistant clinical isolates were collected, of which 146 were indentified microscopically and biochemically as MRSA. Both biofilm formation and efflux pump activity were assessed for linezolid-resistant MRSA (LR-MRSA) using the microtiter plate and carbonyl cyanide 3-chlorophenylhydrazone (CCCP) methods, respectively. Linezolid resistance was further characterized by polymerase chain reaction (PCR) amplification and sequencing of domain V of 23 S rRNA; rplC; rplD;and rplV genes. Meanwhile, some resistance genes were investigated: cfr; cfr(B); optrA; msrA;mecA; and vanA genes. To combat LR-MRSA, the effect of combining linezolid with each of 6 different antimicrobials was investigated using the checkerboard assay. Results Out of the collected MRSA isolates (n = 146), 5.48% (n = 8) were LR-MRSA and 18.49% (n = 27) were vancomycin-resistant (VRSA). It is worth noting that all LR-MRSA isolates were also vancomycin-resistant. All LR-MRSA isolates were biofilm producers (r = 0.915, p = 0.001), while efflux pumps upregulation showed no significant contribution to development of resistance (t = 1.374, p = 0.212). Both mecA and vanA genes were detected in 92.45% (n = 147) and 6.92% (n = 11) of methicillin-resistant isolates, respectively. In LR-MRSA isolates, some 23 S rRNA domain V mutations were observed: A2338T and C2610G (in 5 isolates); T2504C and G2528C (in 2 isolates); and G2576T (in 1 isolate). Amino acids substitutions were detected: in L3 protein (rplC gene) of (3 isolates) and in L4 protein (rplD gene) of (4 isolates). In addition, cfr(B) gene was detected (in 3 isolates). In 5 isolates, synergism was recorded when linezolid was combined with chloramphenicol, erythromycin, or ciprofloxacin. Reversal of linezolid resistance was observed in some LR-MRSA isolates when linezolid was combined with gentamicin or vancomycin. Conclusions LR-MRSA biofilm producers’ phenotypes evolved in the clinical settings in Egypt. Various antibiotic combinations with linezolid were evaluated in vitro and showed synergistic effects. |
| first_indexed | 2024-04-09T18:55:45Z |
| format | Article |
| id | doaj.art-3119fbe2b9074dc8a337a44a2f5ba9c5 |
| institution | Directory Open Access Journal |
| issn | 1476-0711 |
| language | English |
| last_indexed | 2024-04-09T18:55:45Z |
| publishDate | 2023-04-01 |
| publisher | BMC |
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| series | Annals of Clinical Microbiology and Antimicrobials |
| spelling | doaj.art-3119fbe2b9074dc8a337a44a2f5ba9c52023-04-09T11:10:23ZengBMCAnnals of Clinical Microbiology and Antimicrobials1476-07112023-04-0122111610.1186/s12941-023-00574-2Phenotypic and genotypic characterization of linezolid resistance and the effect of antibiotic combinations on methicillin-resistant Staphylococcus aureus clinical isolatesAsmaa I. AbdAlhafiz0Nooran S. Elleboudy1Khaled M. Aboshanab2Mohammad M. Aboulwafa3Nadia A. Hassouna4Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams UniversityDepartment of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams UniversityDepartment of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams UniversityDepartment of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams UniversityDepartment of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams UniversityAbstract Background Methicillin-Resistant Staphylococcus aureus (MRSA) causes life-threatening infections, with narrow therapeutic options including: vancomycin and linezolid. Accordingly, this study aimed to characterize phenotypically and genotypically, the most relevant means of linezolid resistance among some MRSA clinical isolates. Methods A total of 159 methicillin-resistant clinical isolates were collected, of which 146 were indentified microscopically and biochemically as MRSA. Both biofilm formation and efflux pump activity were assessed for linezolid-resistant MRSA (LR-MRSA) using the microtiter plate and carbonyl cyanide 3-chlorophenylhydrazone (CCCP) methods, respectively. Linezolid resistance was further characterized by polymerase chain reaction (PCR) amplification and sequencing of domain V of 23 S rRNA; rplC; rplD;and rplV genes. Meanwhile, some resistance genes were investigated: cfr; cfr(B); optrA; msrA;mecA; and vanA genes. To combat LR-MRSA, the effect of combining linezolid with each of 6 different antimicrobials was investigated using the checkerboard assay. Results Out of the collected MRSA isolates (n = 146), 5.48% (n = 8) were LR-MRSA and 18.49% (n = 27) were vancomycin-resistant (VRSA). It is worth noting that all LR-MRSA isolates were also vancomycin-resistant. All LR-MRSA isolates were biofilm producers (r = 0.915, p = 0.001), while efflux pumps upregulation showed no significant contribution to development of resistance (t = 1.374, p = 0.212). Both mecA and vanA genes were detected in 92.45% (n = 147) and 6.92% (n = 11) of methicillin-resistant isolates, respectively. In LR-MRSA isolates, some 23 S rRNA domain V mutations were observed: A2338T and C2610G (in 5 isolates); T2504C and G2528C (in 2 isolates); and G2576T (in 1 isolate). Amino acids substitutions were detected: in L3 protein (rplC gene) of (3 isolates) and in L4 protein (rplD gene) of (4 isolates). In addition, cfr(B) gene was detected (in 3 isolates). In 5 isolates, synergism was recorded when linezolid was combined with chloramphenicol, erythromycin, or ciprofloxacin. Reversal of linezolid resistance was observed in some LR-MRSA isolates when linezolid was combined with gentamicin or vancomycin. Conclusions LR-MRSA biofilm producers’ phenotypes evolved in the clinical settings in Egypt. Various antibiotic combinations with linezolid were evaluated in vitro and showed synergistic effects.https://doi.org/10.1186/s12941-023-00574-2MRSALinezolidBiofilm23 S rRNARibosomal genesMutations |
| spellingShingle | Asmaa I. AbdAlhafiz Nooran S. Elleboudy Khaled M. Aboshanab Mohammad M. Aboulwafa Nadia A. Hassouna Phenotypic and genotypic characterization of linezolid resistance and the effect of antibiotic combinations on methicillin-resistant Staphylococcus aureus clinical isolates Annals of Clinical Microbiology and Antimicrobials MRSA Linezolid Biofilm 23 S rRNA Ribosomal genes Mutations |
| title | Phenotypic and genotypic characterization of linezolid resistance and the effect of antibiotic combinations on methicillin-resistant Staphylococcus aureus clinical isolates |
| title_full | Phenotypic and genotypic characterization of linezolid resistance and the effect of antibiotic combinations on methicillin-resistant Staphylococcus aureus clinical isolates |
| title_fullStr | Phenotypic and genotypic characterization of linezolid resistance and the effect of antibiotic combinations on methicillin-resistant Staphylococcus aureus clinical isolates |
| title_full_unstemmed | Phenotypic and genotypic characterization of linezolid resistance and the effect of antibiotic combinations on methicillin-resistant Staphylococcus aureus clinical isolates |
| title_short | Phenotypic and genotypic characterization of linezolid resistance and the effect of antibiotic combinations on methicillin-resistant Staphylococcus aureus clinical isolates |
| title_sort | phenotypic and genotypic characterization of linezolid resistance and the effect of antibiotic combinations on methicillin resistant staphylococcus aureus clinical isolates |
| topic | MRSA Linezolid Biofilm 23 S rRNA Ribosomal genes Mutations |
| url | https://doi.org/10.1186/s12941-023-00574-2 |
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