In Vitro Production of Panton-Valentine Leukocidin among Strains of Methicillin-Resistant Staphylococcus aureus Causing Diverse Infections (original) (raw)
Related papers
The Journal of Infectious Diseases, 2010
The role of Panton-Valentine leukocidin (PVL) in Staphylococcus aureus infections is controversial. We used a mouse model of skin infection to compare the virulence of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) strains with different levels of PVL production. Differences in PVL production were not associated with mutations in the genes lukS-PV and lukF-PV. However, MSSA and MRSA strains that produced high levels of PVL caused larger skin abscesses, higher bacterial burdens, and more tissue inflammation than did low-PVL-producing strains. Together, these data suggest that (1) the effect of PVL on the pathogenesis of staphylococcal infection may depend on the level of toxin produced and (2) many strains of MSSA that cause soft-tissue infections produce higher levels of PVL than do MRSA strains. Community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) is an emerging pathogen with an evolving epidemiology. Several virulence factors contribute to the pathogenicity of S. aureus. One that may have particular importance is Panton-Valentine leukocidin (PVL), a pore-forming cytotoxin
The Journal of Infectious Diseases, 2010
The role of Panton-Valentine leukocidin (PVL) in Staphylococcus aureus infections is controversial. We used a mouse model of skin infection to compare the virulence of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) strains with different levels of PVL production. Differences in PVL production were not associated with mutations in the genes lukS-PV and lukF-PV. However, MSSA and MRSA strains that produced high levels of PVL caused larger skin abscesses, higher bacterial burdens, and more tissue inflammation than did low-PVL-producing strains. Together, these data suggest that (1) the effect of PVL on the pathogenesis of staphylococcal infection may depend on the level of toxin produced and (2) many strains of MSSA that cause soft-tissue infections produce higher levels of PVL than do MRSA strains. Community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) is an emerging pathogen with an evolving epidemiology. Several virulence factors contribute to the pathogenicity of S. aureus. One that may have particular importance is Panton-Valentine leukocidin (PVL), a pore-forming cytotoxin
Panton -Valentine leukocidin (PVL) produced by community acquired methicillin Staphyloccous aureus involved in skin and soft tissue infection comprised of two fraction namely PVLS and PVLF . In the present study , one of aims was to identify resistance profile for MRSA, and other aims are detection and purification of PVL toxin. A total of (100) MRSA isolates were recovered from hospitalized patients in Baghdad in 2013 . The percentage of PVLpositive was represented by 27% of isolates and 55.6% of them isolated from wound and 40.7% of them from abscess . All isolates were resistant to cloxacillin , followed by cefoxitin and cephalexin and lincomycin (86, 51 and 23)% respectively. Result of PVL toxin purified by sequatinal ammonium sulphate precipitation ion exchange and gel filtration with sepharos 6B then hydroxyl aptite chromatography revealed the protein concentration was 22.4 µg/ml with molecular weight 35.4kDa.
Journal of Medical Case Reports, 2011
Introduction Certain Staphylococcus aureus strains produce Panton-Valentine leukocidin, a toxin that lyses white blood cells causing extensive tissue necrosis and chronic, recurrent or severe infection. This report documents a confirmed case of methicillin-sensitive Staphylococcus aureus strain harboring Panton-Valentine leukocidin genes from Trinidad and Tobago. To the best of our knowledge, this is the first time that such a case has been identified and reported from this country. Case presentation A 13-year-old Trinidadian boy of African descent presented with upper respiratory symptoms and gastroenteritis-like syptoms. About two weeks later he was re-admitted to our hospital complaining of pain and weakness affecting his left leg, where he had received an intramuscular injection of an anti-emetic drug. He deteriorated and developed septic arthritis, necrotizing fasciitis and septic shock with acute respiratory distress syndrome, leading to death within 48 hours of admission despite intensive care treatment. The infection was caused by S. aureus. Bacterial isolates from specimens recovered from our patient before and after his death were analyzed using microarray DNA analysis and spa typing, and the results revealed that the S. aureus isolates belonged to clonal complex 8, were methicillin-susceptible and positive for Panton-Valentine leukocidin. An autopsy revealed multi-organ failure and histological tissue stains of several organs were also performed and showed involvement of his lungs, liver, kidneys and thymus, which showed Hassal's corpuscles. Conclusion Rapid identification of Panton-Valentine leukocidin in methicillin-sensitive S. aureus isolates causing severe infections is necessary so as not to miss their potentially devastating consequences. Early feedback from the clinical laboratories is crucial.
2015
Methicillin-Resistant Staphylococcus aureus (MRSA), a pathogenic strain of Staphylococcus aureus, results in thousands of infections and associated deaths each year. A strain of MRSA, USA300, has been identified as the most common cause of skin and soft tissue infections acquired from the community in the United States. The goal of our study is to determine the prevalence of the USA300 strain, responsible for new community-associated MRSA infections, on Belmont University’s campus via PCR detection of the Panton-Valentine Leukocidin (PVL) gene, a bacterial toxin. We collected isolates from different locations on Belmont’s campus, confirmed them as MRSA using Gram staining, coagulase testing, and the use of the Kirby-Bauer disk diffusion assay. Bacterial DNA was isolated and PCR analysis performed to identify the PVL gene. We found PVL in Intermediate Methicillin Resistant Staphylococcus aureus isolates. This is surprising because the presence of PVL causes otherwise harmless Staph i...
Panton-Valentine leukocidin in community and hospital-acquired Staphylococcus aureus strains
Biotechnology & Biotechnological Equipment, 2014
Staphylococcus aureus causes serious hospital-acquired (HA) and community acquired (CA) infections. Skin and softtissue infections especially are sometimes caused by strains harbouring Panton-Valentine leukocidin (PVL). PVL belongs to a family of bi-component leukocidal toxins produced by staphylococci. It is a pore forming toxin encoded by lukF-PV and lukS-PV. A total of 70 S. aureus strains: 38 (54%) methicillin-resistant (MRSA) and 32 (46%) methicillin-susceptible (MSSA), were isolated from patients admitted to Dicle University Hospital (Turkey). Identification of S. aureus and antibiotics-susceptibility testing were performed with PHOENIX 100. PVL genes and mecA genes were detected by polymerase chain reaction. Of the 70 studied strains, 36 ones (51%) were community acquired and 34 ones (49%) were hospital acquired . A total of 38 (54%) strains were positive for mecA (mecAC), of which 32 ones (84%) were HA. Of the mecA strains, 30 (94%) were CA. Of the 70 studied strains, 12 (17%) strains were PVLC: 8 (22%) of the 36 CA strains and 4 (12%) of the 34 HA strains. Of the 12 PVLC strains, 4 strains were mecAC. The PVL positivity rate was 25% in MSSA, whereas 10.5% in MRSA. Of the overall PVLC strains, seven strains were obtained from wounds; four ones from skin abscess; and one from blood culture. Taken together, the obtained results showed a substantial level of PVL genes in the studied region. Although PVL is known as a common virulence factor of CA MRSA, HA MRSA isolates in our study showed a considerable rate of PVL positivity. Keywords: Staphylococcus aureus; Panton-Valentine leukocidin; MRSA; MSSA
2017
Background: There is increasing evidence that the clones of Panton-Valentine Leukocidin toxin, (PVLT)-producing methicillin-resistant Staphylococcus aureus (MRSA) are replacing toxin non-producing methicillin-resistant Staphylococcus aureus) in healthcare settings. Our study sought to characterize clinical isolates of MRSA and the prevalence of PVL toxin producing MRSA in our tertiary healthcare center in the United States during a one-year period. Methods: A total of 5,497 clinical samples submitted to microbiology laboratory were processed for presumptive identification of MRSA with further confirmation by polymerase chain reaction (PCR) for the identification of mecA, Staphylococcal chromosome cassette mec (SCCmec) type, and Panton-Valentine Leukocidin Toxin (PVLT) gene. The antibiotyping was performed using VITEK® 2 system, and disk diffusion method, and data graphed using Microsoft Office program. Results: Of Staphylococcus aureus isolates 52.2% (n=617) were MRSA. The prevalenc...
The Journal of Infectious Diseases, 2010
The current pandemic of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) skin infections is caused by several genetically unrelated clones. Here, we analyzed virulence of globally occurring CA-MRSA strains in a rabbit skin infection model. We used rabbits because neutrophils from this animal species have relatively high sensitivity to Panton-Valentine leukocidin (PVL), a toxin epidemiologically correlated with many CA-MRSA infections. Virulence in the rabbit model correlated with in vitro neutrophil lysis and transcript levels of phenol-soluble modulin a and a-toxin, but not PVL genes. Furthermore, abscesses caused by USA300 and its PVL-negative progenitor USA500 were comparatively large and similar in size, suggesting that PVL has played a limited role in the evolution of USA300 virulence in the context of skin infections. Our study indicates a major but not exclusive impact of virulence on the epidemiological success of USA300 and other CA-MRSA strains and emphasizes the importance of core genome-encoded toxins in CA-MRSA skin infections.
Virulence determinants in community and hospital meticillin-resistant Staphylococcus aureus
Journal of Hospital Infection, 2007
Staphylococcus aureus produces many virulence factors, most of which act in a synergistic and coordinated fashion. Some appear to be specifically associated with certain severe infections and are produced by meticillin-resistant Staphylococcus aureus (MRSA) clones distributed worldwide. Superantigenic exotoxins appear to be major virulence factors in hospital MRSA clones (HA-MRSA), and staphylococcal enterotoxin A (SEA) may be involved in the physiopathology of septic shock. Panton Valentine Leucocidin (PVL) has emerged as a major virulence factor in communityacquired Staphylococcus aureus (CA-MRSA) infections. In particular, the leukotoxic action of PVL is responsible for the high mortality rate associated with necrotizing pneumonia. CA-MRSA can also harbour the toxic shock toxin 1 (TSST-1) and rarely the exfoliative toxin.