Association of virulence genes with mecA gene in Staphylococcus aureus isolates from Tertiary Hospitals in Nigeria

Alli, O. A. Terry; Ogbolu, David Olusoga; Shittu, Adebayo; Okorie, Anthony N; Akinola, John O; Daniel, John B

doi:10.4103/0377-4929.168875

Cited by 27 publications

(25 citation statements)

References 25 publications

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“…Regarding other reports, the complex role of mecRI in the pathogenicity of MRSA strains can be concluded. They also confirmed that the cooperation of VFs and regulating β-lactamase genes also play a critical role in increasing the pathogenicity of S. aureus isolates [ 15 , 29 – 31 ].…”

Section: Discussionmentioning

confidence: 72%

Regulation of virulence and β-lactamase gene expression in Staphylococcus aureus isolates: cooperation of two-component systems in bloodstream superbugs

et al. 2021

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Background Methicillin-resistant Staphylococcus aureus (MRSA)-bloodstream infections (BSI) are predominantly seen in the hospital or healthcare-associated host. Nevertheless, the interactions of virulence factor (VFs) regulators and β-lactam resistance in MRSA-BSI are unclear. This study aims to characterize the molecular relationship of two-component systems of VFs and the expression of the β-lactamase gene in MRSA-BSI isolates. In this study, 639 samples were collected from BSI and identified by phenotypic methods. We performed extensive molecular characterization, including SCCmec type, agr type, VFs gene profiles determinations, and MLST on isolates. Also, a quantitative real-time PCR (q-RT PCR) assay was developed for identifying the gene expressions. Results Ninety-one (91) S. aureus and 61 MRSA (67.0%) strains were detected in BSI samples. The presence of VFs and SCCmec genes in MRSA isolates were as follows: tst (31.4%), etA (18.0%), etB (8.19%), lukS-PVL (31.4%), lukF-PV (18.0%), lukE-lukD (16.3%), edin (3.2%), hla (16.3%), hlb (18.0%), hld (14.7%), hlg (22.9%), SCCmecI (16.3%), SCCmecII (22.9%), SCCmecIII (36.0%), SCCmecIV (21.3%), and SCCmecV (16.3%). Quantitative real-time PCR showed overexpression of mecRI and mecI in the toxigenic isolates. Moreover, RNAIII and sarA genes were the highest expressions of MRSA strains. The multi-locus sequence typing data confirmed a high prevalence of CC5, CC8, and CC30. However, ST30, ST22, and ST5 were the most prevalent in the resistant and toxigenic strains. Conclusion We demonstrated that although regulation of β-lactamase gene expressions is a significant contributor to resistance development, two-component systems also influence antibiotic resistance development in MRSA-BSI isolates. This indicates that resistant strains might have pathogenic potential. We also confirmed that some MLST types are more successful colonizers with a potential for MRSA-BSI.

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Section: Discussionmentioning

confidence: 72%

Regulation of virulence and β-lactamase gene expression in Staphylococcus aureus isolates: cooperation of two-component systems in bloodstream superbugs

et al. 2021

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“…Slime production is considered as a significant virulence factor for some strains of staphylococci [16]. The pathogenicity of S. aureus depends on various virulence factors associated with adherence, evasion of the immune system and damage of the host [6,7].…”

Section: Discussionmentioning

confidence: 99%

“…Virulence factors of S. aureusinclude slime formation, secreted enzymes, toxins like lipases, DNase, proteases, hemolysins and some super antigens like toxic shock syndrome toxin and enterotoxin [5]. The pathogenicity of S. aureus depends on various virulence factors associated with adherence, evasion of the immune system and damage of the host [6,7]. The presence of…”

Section: Introductionmentioning

confidence: 99%

Study of the virulence factors and antimicrobial susceptibility profile of staphylococcus aureus isolated from clinical samples at tertiary care centre

Halesh

Koppad

et al. 2019

Trop J Pathol Microbiol

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Introduction: Staphylococcus aureusis an important cause of healthcare-associated infections. The increasing resistance of this pathogen to various antibiotics complicates treatment. Present study was conducted to isolate staphylococcus aureus from various clinical samples, to study the few virulence factors, antibiogram and to detect methicillin resistance among them. Materials and Methods: Present study was done over a period of six months. The study was conducted on 100 staphylococcus aureus isolated from various clinical samples. The organisms were identified as per standard conventional methods. The antibiotic sensitivity testing of the isolates was done by Kirby Bauer's Disk Diffusion method according to CLSI guidelines. These strains were screened for DNase production, beta hemolytic property and slime production. Results: Among 100 clinical isolates of staphylococcus aureus 82% of them showed beta hemolysis, 79% produces DNase, 72% produces slime. The proportion of MRSA amongst S. aureus isolates was found to be 53%. MSSA were 100% sensitive to vancomycin and linezolid 85.10% to Doxycycline, 82.98% to clindamycin, 72.34% to chloramphenicol, 68.09% Co-trimoxozole, 65.95% to erythromycin, 61.70% gentamicin, 51.06% to Ciprofloxacin, 12.77% topenicillin. MRSA were 100% sensitive to vancomycin and linezolid, 71.69% Doxycycline, 64.15% to Chloramphenicol, 60.37% to Clindamycin, 43.39% to Ciprofloxacin, 39.62% Gentamicin, 37.74% Co-trimoxozole, 35.84% to Erythromycin and all the isolates were resistant to penicillin. Conclusion: Understanding of virulence mechanisms and antibiotic susceptibility pattern of Staphylococcus aureus is important for effective management of infections.

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“…In surgical site infections for 103 patients with orthopedic surgery in a hospital in Port Harcourt, Nigeria, the commonest pathogen was S. aureus (34%) including 15 patients with MRSA [27]. and prevalence of MRSA with mecA gene as 42.3% from 156 S. aureus in clinical isolates from South Western Nigeria with domination of SCCmec II and SCCmec V [28].…”

Section: Mrsa Prevalence In Africamentioning

confidence: 99%

Prevalence, Diagnosis and Local Susceptibility of Staphylococci Infections

Ayeni¹

2019

Staphylococcus Aureus

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Staphylococci are normally harmless commensals occurring on the skin, mucous membrane and the general environment. However, they are increasingly implicated in different infectious states. Of particular interest is the advent of methicillin-resistant Staphylococcus aureus (MRSA) with its attendance resistance to beta lactam antibiotics. Several infectious states are now emerging with staphylococci being implicated in the infections, e.g. S. saprophyticus has been implicated in urogenital infection. It would be interesting to document the prevalence of staphylococci in different infectious state. The identification of staphylococci is supposed to be a straightforward procedure, but an alarming misidentification rate is emerging in low resource laboratories, especially in places where identification is solely by growth and fermentation on mannitol salt agar (MSA). Finally, empirical treatment of any staphylococci infection will depend on local suspectibility pattern of the strains as the susceptibilities vary from environment to environment. This chapter summarizes the current knowledge regarding the prevalence, diagnosis and local susceptibility of staphylococci in different parts of the world.

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Association of virulence genes with mecA gene in Staphylococcus aureus isolates from Tertiary Hospitals in Nigeria

Abstract: The study concluded that there is a high prevalence of MRSA in Nigeria with association of eta and icaA genes with mecA gene in S. aureus isolates.

Cited by 27 publications

References 25 publications

Regulation of virulence and β-lactamase gene expression in Staphylococcus aureus isolates: cooperation of two-component systems in bloodstream superbugs

Regulation of virulence and β-lactamase gene expression in Staphylococcus aureus isolates: cooperation of two-component systems in bloodstream superbugs

Study of the virulence factors and antimicrobial susceptibility profile of staphylococcus aureus isolated from clinical samples at tertiary care centre

Prevalence, Diagnosis and Local Susceptibility of Staphylococci Infections

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