Glycopeptide intermediate Staphylococcus aureus and prevalence of the luk-PV gene in clinical isolates, in Northern Lebanon

• Published in: Médecine et maladies infectieuses 2014-05, Vol.44 (5), p.223-228
• Main Authors: El Ayoubi, M.-D., Hamze, M., Mallat, H., Achkar, M., Dabboussi, F.
• Format: Article
• Language: English
• Subjects: Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Bacterial diseases; Bacterial Proteins - genetics; Bacterial Toxins - genetics; Biological and medical sciences; Disk Diffusion Antimicrobial Tests; DNA, Bacterial - genetics; DNA, Ribosomal - genetics; Drug Resistance, Multiple, Bacterial - genetics; Exotoxins - genetics; Genes, Bacterial; hGISA; Human bacterial diseases; Humans; Infectious diseases; Lebanon - epidemiology; Leucocidine de Panton-Valentine; Leukocidins - genetics; Medical sciences; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - genetics; Methicillin-Resistant Staphylococcus aureus - pathogenicity; Microbial Sensitivity Tests; MRSA; Panton-Valentine leukocidin; Penicillin-Binding Proteins; Pharmacology. Drug treatments; Prevalence; Ribotyping; RNA, Bacterial - genetics; RNA, Ribosomal, 16S - genetics; SARM; Sequence Analysis, DNA; Staphylococcal Infections - drug therapy; Staphylococcal Infections - epidemiology; Staphylococcal Infections - microbiology; Staphylococcal infections, streptococcal infections, pneumococcal infections; Staphylococcus aureus; Teicoplanin - pharmacology; Vancomycin - pharmacology; Virulence - genetics
• ISSN: 0399-077X; 1769-6690
• DOI: 10.1016/j.medmal.2014.03.004

The aim of our study was to confirm the identification of 113 meticillin-resistant Staphylococcus aureus (MRSA) strains by pyrosequencing, to determine the susceptibility of these clinical isolates to various classes of antibiotics, to determine the minimum inhibitory concentration (MIC) to glycopeptides, and to detect mecA and luk-PV genes. The Staphylococcus species was identified by pyrosequencing of the variable region (V3) of the 16SrRNA. The susceptibility of these 113 strains of MRSA to antibiotics was determined by the disk diffusion method on Mueller-Hinton agar. The MIC of glycopeptides was determined by using the dilution method on solid media. mecA gene and luk-PV gene were detected by PCR. The disk diffusion method proved full susceptibility to vancomycin, teicoplanin, and linezolid; whereas MIC (dilution method) indicated that 5/113 strains were resistant to teicoplanin, giving a probability of having heterogeneous glycopeptide intermediate S. aureus (hGISA) strains. The mecA gene was detected in all MRSA strains ruling out the probability of having new variants of this gene in the tested strains. The luk-PV gene was detected in 28 out of 113 MRSA strains (24.8%). The originality of this study was the detection of hGISA strains knowing that they were susceptible to glycopeptides according to the diffusion method. Thus it is necessary to check the level of susceptibility of MRSA clinical isolates to glycopeptides for immunodeficient patients, by determining the MIC. Confirmer l’identification de 113 souches de Staphylococcus aureus résistante à la méticilline (SARM) par pyroséquencage, déterminer le niveau de sensibilité de ces isolats cliniques à différentes classes d’antibiotiques, déterminer la concentration minimale inhibitrice (CMI) aux glycopeptides, et détecter la présence des gènes mecA et luk-PV. L’identification des espèces de Staphylococcus a été faite par pyroséquencage de la région variable (V3) de l’ARNr16S. La sensibilité des souches aux antibiotiques a été déterminée par la méthode de diffusion des disques sur gélose de Mueller-Hinton. La CMI aux glycopeptides a été déterminée par la méthode de dilution en milieu solide. Les gènes mecA et luk-PV ont été détectés par PCR. La méthode de diffusion des disques a révélé une sensibilité totale aux vancomycine, teicoplanine et linézolide ; alors que la détermination de la CMI (méthode de dilution) a montré que 5/113 souches résistaient à la teicoplanine, donnant une probabilité d’avoi