Prevalence of Panton-Valentine Leukocidin Gene among Community AcquiredStaphylococcus aureus: A Real-Time PCR Study

Abstract

Panton-Valentine leukocidin (luk-pv) is a cytotoxin that causes leukocyte destruction and tissue necrosis. The aim of this study was to determine the prevalence of the pv1, mecA, and nuc genes in Staphylococcus aureus isolates obtained from anterior nares and superficial infection sites of skin in a slum population of West Bengal, India. Expression level of pv1 gene was also analysed. Twenty-two S. aureus strains were isolated, and phenotype and genotype specific examinations for S. aureus isolates were carried out. Molecular identification was done by PCR using species-specific 16S rRNA primer pairs and finally 22 isolates were found to be positive as S. aureus. The antibiotic responsiveness of all these isolates and the minimum inhibitory concentration (MIC) of MRSA isolates were determined using the broth dilution method with vancomycin. Antibiogram analysis of isolated S. aureus strains with respect to different antimicrobial agents revealed antibiotic resistance ranging from 27 to 91%. The results of MIC for vancomycin showed 95% of strains to be VSSA and 5% to be VISA. 68% isolates were resistant to methicillin. All the isolates were subjected to detection of pv1, mecA, and nuc genes, and 9%, 68%, and 27% were found to harbour pvl, mecA, and nuc genes, respectively. All the MRSA strains produced high to moderate levels of biofilm. pvl gene expression was carried out in vitro by Real-Time PCR. The low ∆Ct value (0.493) was indicative of high expression of pvl in one S. aureus strain. Thus, detection of pvl gene in community acquired S. aureus indicates the emergence of pathogenic S. aureus in community setup in the studied region. The existing exploration is extremely imperative and informative for the high level multi-drug resistant S. aureus infections inclusive of MRSA.

<p>Antimicrobial Susceptibility Testing and Phenotypic Detection of MRSA Isolated from Diabetic Foot Infection</p>

“…International Journal of General Medicine 2020:13 1350 performed. 20 Table 2 illustrates the base pair sequences of both primers.…”

“…DNA samples to be run in PCR were diluted to10 ng/µL. 20 Multiplex conventional PCR was used for detection of mecA and PVL for all isolated S. aureus strains (24) by using the same primer as in Table 1, but with different PCR conditions, programmed in the protocol by Bhatta et al (2016) and illustrated in Table 3.…”

“…Main stock primers (100 pmol/µL) were prepared by suspending each primer (forward and reverse) in free DNA and RNA injection water (for mecA1 and mecA2 oligonucleotide by adding 300 µL, for LUK- PV -1270 µL, and for LUK- PV -2290 µL), according to what was performed. 20 Table 2 illustrates the base pair sequences of both primers.…”

Molecular Detection of Panton Valentine Leukocidin Toxin in Clinical Isolates of Staphylococcus aureus from Kiambu County, Kenya

“…There is significant variation in prevalence of PVL among S. aureus and methicillin-resistant S. aureus (MRSA) infections worldwide. Globally, prevalence of PVL toxin has been reported to increase across different countries such as Japan, USA, China, Germany, Egypt, Nigeria, and Kenya ranging from 12 to 90% [ 11 – 13 ]. Various studies have reported PVL prevalence with France at 5%, Bangladesh at 14.3%, Saudi Arabia at 8.1%, UK at 8.1%, Gambia at 72.9%, Nigeria at 10.7%, and Ghana at 75% [ 1 , 12 , 14 ].…”

Screening, Safety Evaluation, and Mechanism of Two Lactobacillus fermentum Strains in Reducing the Translocation of Staphylococcus aureus in the Caco-2 Monolayer Model

“…16s rRNA was used as the internal control (housekeeping gene). Primers for virulence genes were designed and synthesized (Sangon Biotech, Shanghai Co., Ltd.) according to previous reports ( Table 1; Ster et al, 2005;Karmakar et al, 2018). Real-time PCR was performed using the above prepared DNA intercalating fluorescent agent SYBR green for product detection.…”