Objective:To identify the pathogenic gene of Panton-Valentine leukocidin in methicillin-resistant Staphylococcus aureus strain isolated from clinical specimens of burn patients in Shaheed Zare Burn Hospital.Methods:A ...Objective:To identify the pathogenic gene of Panton-Valentine leukocidin in methicillin-resistant Staphylococcus aureus strain isolated from clinical specimens of burn patients in Shaheed Zare Burn Hospital.Methods:A total of 104 samples of Staphylococcus were collected and 78 aureus samples were isolated from Zare Hospital patients from November 2016 to July 2017.All isolates were identified using a standard biochemical and laboratory methodology in accordance with CLSI principles,and disk agar diffusion antibiogram were performed to identify methicillin resistant colonies.Then the presence of the Panton-Valentine leukocidin gene was tested by PCR.Results:Of the methicillin-resistant Staphylococcus aureus samples,80%were negative for the Panton-Valentine leukocidin gene,and only 20%of the samples had Panton-Valentine leukocidin gene.Male and female patients showed no significant difference in the positivity rate of Panton-Valentine leukocidin gene(16.12%vs.33.33%)(P=0.25).Besides,there was no significant difference in bacterial resistance or susceptibility to antibiotics between samples with or without the Panton-Valentine leukocidin gene.Conclusions:In recent years,increased resistance has been a serious threat.The resistance or susceptibility of Staphylococcus aureus strains to different antibiotics is different in different geographical locations.展开更多
Panton-Valentine leukocidin (PVL) is one of the toxins responsible for increased virulence of <em>Staphylococcus aureus</em>. In school settings where children are in close contact with each other, <em&...Panton-Valentine leukocidin (PVL) is one of the toxins responsible for increased virulence of <em>Staphylococcus aureus</em>. In school settings where children are in close contact with each other, <em>S. aureus</em> strains, including those that may produce PVL, can be transmitted and spread in the community. Twenty-two multi-drug resistant MRSA nasal isolates from children enrolled in five schools in the town of Mariental and the multi-drug resistant American Type Culture Collection MRSA reference strain <em>S. aureus</em> ATCC 33591 (PVL-negative control) were used for molecular assays. Plasmid deoxyribonucleic acid (DNA) of isolates was amplified by polymerase chain reaction (PCR) and amplified PCR products were electrophoresed on a 2.5% (w/v) agarose gel containing 12 μl 0.5 μg/ml ethidium bromide and 1× TAE (Tris-acetate-EDTA) buffer at 90 volts for 50 minutes. The developed gel was viewed for the PVL-associated <em>lukS</em> and <em>lukF</em> genes that amplified at 151 bp and 406 bp, respectively. Our results indicated that seven nasal isolates had PVL toxin gene(s). From the seven isolates, three were tested positive for both <em>lukS</em> and<em> lukF</em>genes, one tested positive for only<em> lukS</em>, and three tested positive for only <em>lukF</em>. Two of the isolates harbouring both<em> lukS</em> and <em>lukF</em> genes shared the same antibiotic resistance pattern and one of them could also produce enterotoxin A. One of the isolates with only <em>lukF </em>gene could produce enterotoxins B and C. These toxin-producing isolates can be expected to be more virulent than non-producers. Children should be educated on the importance of regular handwashing with soap and water to prevent the spread of potentially virulent staphylococci amongst them and the wider community. This work warrants a larger study to be carried out to investigate PVL toxin and its associated infections in <em>Staphylococcus</em> from school children in Namibia.展开更多
We previously observed the elicitation of a significant delayed-type hypersensitivity response to the Panton-Valentine leukocidin (PVL) LukS-PV subunit following subcutaneous immunization (Brown et al., Clinical Micro...We previously observed the elicitation of a significant delayed-type hypersensitivity response to the Panton-Valentine leukocidin (PVL) LukS-PV subunit following subcutaneous immunization (Brown et al., Clinical Microbiology and Infection, 2009, 156: 156-164). A LukS-PV-specific cell line (LST) was screened for proliferative responses against a panel of 25 amino acid-long peptides spanning the length of LukS-PV (amino acids 29-312). This analysis demonstrated that stimulation of LST with LukS-PV resulted in significant proliferative responses and adoptive transfer of LST into na?ve mice conferred a LukS-PV-specific DTH response following challenge. Challenge of mice adoptively transferred with LST with peptides 7 (149-173), 8 (169-193) and 14 (289-312) also elicited a measurable DTH response suggesting that these peptides contained T cell epitopes.展开更多
基金This article was financially supported by Sari Branch,IslamicAzad University with grant number 410.
文摘Objective:To identify the pathogenic gene of Panton-Valentine leukocidin in methicillin-resistant Staphylococcus aureus strain isolated from clinical specimens of burn patients in Shaheed Zare Burn Hospital.Methods:A total of 104 samples of Staphylococcus were collected and 78 aureus samples were isolated from Zare Hospital patients from November 2016 to July 2017.All isolates were identified using a standard biochemical and laboratory methodology in accordance with CLSI principles,and disk agar diffusion antibiogram were performed to identify methicillin resistant colonies.Then the presence of the Panton-Valentine leukocidin gene was tested by PCR.Results:Of the methicillin-resistant Staphylococcus aureus samples,80%were negative for the Panton-Valentine leukocidin gene,and only 20%of the samples had Panton-Valentine leukocidin gene.Male and female patients showed no significant difference in the positivity rate of Panton-Valentine leukocidin gene(16.12%vs.33.33%)(P=0.25).Besides,there was no significant difference in bacterial resistance or susceptibility to antibiotics between samples with or without the Panton-Valentine leukocidin gene.Conclusions:In recent years,increased resistance has been a serious threat.The resistance or susceptibility of Staphylococcus aureus strains to different antibiotics is different in different geographical locations.
文摘Panton-Valentine leukocidin (PVL) is one of the toxins responsible for increased virulence of <em>Staphylococcus aureus</em>. In school settings where children are in close contact with each other, <em>S. aureus</em> strains, including those that may produce PVL, can be transmitted and spread in the community. Twenty-two multi-drug resistant MRSA nasal isolates from children enrolled in five schools in the town of Mariental and the multi-drug resistant American Type Culture Collection MRSA reference strain <em>S. aureus</em> ATCC 33591 (PVL-negative control) were used for molecular assays. Plasmid deoxyribonucleic acid (DNA) of isolates was amplified by polymerase chain reaction (PCR) and amplified PCR products were electrophoresed on a 2.5% (w/v) agarose gel containing 12 μl 0.5 μg/ml ethidium bromide and 1× TAE (Tris-acetate-EDTA) buffer at 90 volts for 50 minutes. The developed gel was viewed for the PVL-associated <em>lukS</em> and <em>lukF</em> genes that amplified at 151 bp and 406 bp, respectively. Our results indicated that seven nasal isolates had PVL toxin gene(s). From the seven isolates, three were tested positive for both <em>lukS</em> and<em> lukF</em>genes, one tested positive for only<em> lukS</em>, and three tested positive for only <em>lukF</em>. Two of the isolates harbouring both<em> lukS</em> and <em>lukF</em> genes shared the same antibiotic resistance pattern and one of them could also produce enterotoxin A. One of the isolates with only <em>lukF </em>gene could produce enterotoxins B and C. These toxin-producing isolates can be expected to be more virulent than non-producers. Children should be educated on the importance of regular handwashing with soap and water to prevent the spread of potentially virulent staphylococci amongst them and the wider community. This work warrants a larger study to be carried out to investigate PVL toxin and its associated infections in <em>Staphylococcus</em> from school children in Namibia.
文摘We previously observed the elicitation of a significant delayed-type hypersensitivity response to the Panton-Valentine leukocidin (PVL) LukS-PV subunit following subcutaneous immunization (Brown et al., Clinical Microbiology and Infection, 2009, 156: 156-164). A LukS-PV-specific cell line (LST) was screened for proliferative responses against a panel of 25 amino acid-long peptides spanning the length of LukS-PV (amino acids 29-312). This analysis demonstrated that stimulation of LST with LukS-PV resulted in significant proliferative responses and adoptive transfer of LST into na?ve mice conferred a LukS-PV-specific DTH response following challenge. Challenge of mice adoptively transferred with LST with peptides 7 (149-173), 8 (169-193) and 14 (289-312) also elicited a measurable DTH response suggesting that these peptides contained T cell epitopes.
