Screening of genes encoding adhesion factors and biofilm production in methicillin resistant strains of Staphylococcus aureus isolated from Palestinian patients
Date
2019-07-12
Authors
Azmi, Kifaya
Qrei, Walaa
Abdeen, Ziad
Journal Title
Journal ISSN
Volume Title
Publisher
BioMed Central
Abstract
Background: Intercellular adhesion and biofilm production by Staphylococcus aureus makes these bacteria resistant
to antimicrobial therapy. Here, Methicillin-resistant Staphylococcus aureus (MRSA) strains were characterized and the
prevalence of genes encoding adhesion factors and biofilm formation was determined.
Results: All 248 MRSA isolates identified by cefoxitin disc diffusion were positive for the mecA gene. SCCmec-IV was
the most frequently detected genotype (92.7%) and SCCmec-IVa was also very prevalent (84.3%). The quantitative
microtiter plate assay showed that all the isolates were able to produce biofilm with levels ranging from high (21%)
to moderate (46.4%) to low (32.7%).
All the strains possessed the icaD/icaA genes and produced biofilm (P < 0.05). None of the isolates possessed the
bap gene. Furthermore, 94.8% of the isolates were positive for eno, 80.2% for clfA and for clfB, 78.2% for fnbA, 76.2%
for ebps, 62.2% for fib, 39.9% for cna and 29.0% for fnbB. Also, nearly 69.8% of the isolates were positive for the
gene sarA. All four agr groups were present: agr group 1 was predominant with 39.5%; agr group 3. agr group 2
and 3 strains carried more toxin-producing genes, and frequently produced more toxin. Sixty-six (26.6%) of the
strains were multidrug resistant. All were vancomycin sensitive. Agr group I is more resistant to ciprofloxacin and
gentamicin while agr group III is more resistant to erythromycin. Maximum sensitivity was to gentamicin and SXT,
and they could be considered drugs of choice for controlling MRSA mediated infections in this region.
Conclusions: Biofilm development in MRSA might be an ica dependent and one needs to investigate the
involvement of other global regulators, agr and sarA, and their contribution to the biofilm phenotype, as the high
rate of biofilm production among the studied strains of S. aureus.
Description
Keywords
MRSA , Antibiotics , SCCmec , Biofilm , Agr , sarA
Citation
TY - JOUR AU - Azmi, Kifaya AU - Qrei, Walaa AU - Abdeen, Ziad PY - 2019/12/01 SP - T1 - Screening of genes encoding adhesion factors and biofilm production in methicillin resistant strains of Staphylococcus aureus isolated from Palestinian patients VL - 20 DO - 10.1186/s12864-019-5929-1 JO - BMC Genomics ER -