scholarly journals Clonal diversity and genomic characterization of Panton-valentine Leukocidin (PVL)-positive Staphylococcus aureus in Tehran, Iran

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zahra Najafi olya ◽  
Shahin Najar-Peerayeh ◽  
Abbas Yadegar ◽  
Bita Bakhshi
Keyword(s):  
Staphylococcus Aureus ◽  
Molecular Epidemiology ◽  
Clonal Diversity ◽  
Resistance Rate ◽  
Type I ◽  
Limited Information ◽  
Accessory Gene ◽  
Mrsa Strains ◽  
Panton Valentine Leukocidin ◽  
Valentine Leukocidin

Abstract Background Some Staphylococcus aureus strains produce Panton-Valentine leukocidin (PVL), a bi-component pore-forming toxin, which causes leukocyte lysis and tissue necrosis. Currently, there is very limited information on the molecular epidemiology of PVL-encoding S. aureus strains in Iran. This study aimed to determine the molecular epidemiology and genetic background of PVL-positive S. aureus clinical strains isolated from Iranian patients. Methods A total of 28 PVL-positive S. aureus strains were detected from 600 S. aureus isolates between February 2015 and March 2018 from different hospitals in Tehran, Iran. Antimicrobial susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Molecular genotyping was performed using SCCmec and accessory gene regulator (agr) typing, PVL haplotyping, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Results The highest antibiotic resistance rate was found to be against erythromycin (57.1%), followed by ciprofloxacin (42.8%) and clindamycin (35.7%). Moreover, 19 (67.9%) out of 28 S. aureus isolates were identified as MRSA, including CA-MRSA (14/19, 73.7%) and HA-MRSA (5/19, 26.3%). SCCmec type IVa was detected as the predominant type (10/19, 52.6%), followed by type III (5/19, 26.3%) and type V (4/19, 21.1%). The agr type I was identified as the most common type (14/28, 50%), and H and R haplotype groups were observed at frequencies of 67.9 and 32.1%, respectively. Among H variants, the predominant variant was H2 (78/9%). The isolates encompassed 21 different sequence types (STs), including 16 new STs (ST5147 to ST5162). Based on eBURST analysis, the isolates were clustered into five CCs, including CC30, CC22, CC1, CC8, and CC5 (ST5160), and nine singletons. PFGE typing showed that 24 isolates were clustered into A (4 pulsotypes), B (9 pulsotypes), and C (11 pulsotypes) clusters. Conclusions A high prevalence of PVL-positive CA-MRSA strains was detected in Iran. The majority of PVL-positive isolates were of H (mostly H2) variant, while R variant was harbored by 100% of PVL-positive MRSA strains. Also, CC8, CC22, and CC30 were identified as the dominant clones among PVL-encoding S. aureus strains. This study promotes a better understanding of the molecular epidemiology and evolution of PVL-positive S. aureus strains in Iran.

scholarly journals Community acquired MRSA infections in a paediatric population in Greece

2005 ◽  
Vol 10 (5) ◽  
pp. 7-8 ◽  
Author(s):  
S Vourli ◽  
D Perimeni ◽  
A Makri ◽  
M Polemis ◽  
A Voyiatzi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Soft Tissue ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Paediatric Population ◽  
Pfge Pattern ◽  
Soft Tissue Infections ◽  
Paediatric Hospital ◽  
Mrsa Strains ◽  
Panton Valentine Leukocidin ◽  
Valentine Leukocidin

We investigated the characteristics of 20 community acquired methicillin resistant Staphylococcus aureus (MRSA) strains isolated in a paediatric hospital in Athens. Eighteen of these, all isolated from skin and soft tissue infections, carried the Panton-Valentine leukocidin (PVL) determinants. They all were found resistant to fusidic acid, tetracycline and kanamycin, and displayed a PFGE pattern identical to that of the well-described ST80 CA-MRSA clone circulating in various European countries.

scholarly journals Ceftobiprole EfficacyIn Vitroagainst Panton-Valentine Leukocidin Production andIn Vivoagainst Community-Associated Methicillin-Resistant Staphylococcus aureus Osteomyelitis in Rabbits

2012 ◽  
Vol 56 (12) ◽  
pp. 6291-6297 ◽  
Author(s):  
Azzam Saleh-Mghir ◽  
Oana Dumitrescu ◽  
Aurélien Dinh ◽  
Yassine Boutrad ◽  
Laurent Massias ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant ◽  
Content Type ◽  
The Mean ◽  
Mrsa Strains ◽  
Time Kill ◽  
Panton Valentine Leukocidin ◽  
Valentine Leukocidin

ABSTRACTCommunity-associated methicillin-resistantStaphylococcus aureus(CA-MRSA) can cause osteomyelitis with severe sepsis and/or local complications in which a Panton-Valentine leukocidin (PVL) role is suspected.In vitrosub-MIC antibiotic effects on growth and PVL production by 11 PVL+MRSA strains, including the major CA-MRSA clones (USA300, including the LAC strain; USA400; and USA1000), and 11 PVL+methicillin-susceptibleS. aureus(MSSA) strains were tested in microplate culture. Time-kill analyses with ceftobiprole at its MIC were also run with LAC. Efficacies of ceftobiprole (40 mg/kg of body weight subcutaneously [s.c.] four times a day [q.i.d.]) or vancomycin (60 mg/kg intramuscularly [i.m.] twice a day [b.i.d.]) alone or combined with rifampin (10 mg/kg b.i.d.) against rabbit CA-MRSA osteomyelitis, induced by tibial injection of 3.4 × 107CFU of LAC, were compared. Treatment, started 14 days postinoculation, lasted 14 days.In vitro, 6/11 strains cultured with sub-MICs of ceftobiprole produced 1.6- to 4.8-fold more PVL than did the controls, with no link to specific clones. Rifampin decreased PVL production by all tested strains. In time-kill analyses at the LAC MIC (0.75 mg/liter), PVL production rose transiently at 6 and 8 h and then declined 2-fold at 16 h, concomitant with a 2-log10-CFU-count decrease.In vivo, the mean log10CFU/g of bone for ceftobiprole (1.44 ± 0.40) was significantly lower than that for vancomycin (2.37 ± 1.22) (P= 0.034), with 7/10 versus 5/11 bones sterilized, respectively. Combination with rifampin enhanced ceftobiprole (1.16 ± 0.04 CFU/g of bone [P= 0.056], 11/11 sterile bones) and vancomycin (1.23 ± 0.06 CFU/g [P= 0.011], 11/11 sterile bones) efficacies. Ceftobiprole bactericidal activity and the rifampin anti-PVL effect could play a role in these findings, which should be of interest for treating CA-MRSA osteomyelitis.

scholarly journals Panton-Valentine Leukocidin (PVL)-Positive Health Care-Associated Methicillin-Resistant Staphylococcus aureus Isolates Are Associated with Skin and Soft Tissue Infections and Colonized Mainly by Infective PVL-Encoding Bacteriophages

2014 ◽  
Vol 53 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Qiwen Hu ◽  
Hang Cheng ◽  
Wenchang Yuan ◽  
Fangyin Zeng ◽  
Weilong Shang ◽  
...  
Keyword(s):  
Health Care ◽  
Staphylococcus Aureus ◽  
Soft Tissue ◽  
Health Concern ◽  
Soft Tissue Infections ◽  
Positive Health ◽  
Methicillin Resistant ◽  
Mrsa Strains ◽  
Panton Valentine Leukocidin ◽  
Valentine Leukocidin

The emergence of Panton-Valentine leukocidin (PVL)-positive methicillin-resistantStaphylococcus aureus(MRSA) is a public health concern worldwide. PVL is associated with community-associated MRSA and is linked to skin and soft tissue infections (SSTIs). However, PVL genes have also been detected in health care-associated (HA) MRSA isolates. The diseases associated with PVL-positive HA-MRSA isolates and the distributions of PVL-encoding bacteriophages in HA-MRSA have not been determined. In this study, a total of 259 HA-MRSA strains isolated between 2009 and 2012 in China from inpatients with SSTIs, pneumonia, and bacteremia were selected for molecular typing, including staphylococcal cassette chromosomemectyping, multilocus sequence typing, and staphylococcal protein A gene typing. The PVL genes and PVL bacteriophages in the MRSA isolates were characterized by PCR. Among the tested MRSA isolates, 28.6% (74/259) were PVL positive. The high prevalence of PVL-carrying HA-MRSA was observed to be associated with SSTIs but not with pneumonia or bacteremia. The PVL-positive HA-MRSA isolates were colonized mainly by infective PVL phages, namely, Φ7247PVL, ΦSLT, and ΦSa2958. The distribution of PVL-carrying bacteriophages differed geographically. Our study highlights the potential risk of the emergence of multidrug-resistant HA-MRSA strains with increased virulence.

scholarly journals Community-Associated Methicillin-ResistantStaphylococcus aureusLacking PVL, as a Cause of Severe Invasive Infection Treated with Linezolid

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Catarina Gouveia ◽  
Alexandra Gavino ◽  
Ons Bouchami ◽  
Maria Miragaia ◽  
Luis Varandas ◽  
...  
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Synovial Fluid ◽  
Public Health Problem ◽  
Invasive Infection ◽  
Limited Information ◽  
Invasive Infections ◽  
Sport Athlete ◽  
Panton Valentine Leukocidin ◽  
Valentine Leukocidin

Community-associated methicillin-resistantStaphylococcus aureus(CA-MRSA) is an emerging public health problem worldwide. Severe invasive infections have been described, mostly associated with the presence of Panton-Valentine leukocidin (PVL). In Portugal limited information exists regarding CA-MRSA infections. In this study we describe the case of a previously healthy 12-year-old female, sport athlete, who presented to the hospital with acetabulofemoral septic arthritis, myositis, fasciitis, acetabulum osteomyelitis, and pneumonia. The MRSA isolated from blood and synovial fluid was PVL negative and staphylococcal enterotoxin type P (SEP) and type L (SEL) positive, with a vancomycin MIC of 1.0 mg/L and resistant to clindamycin and ciprofloxacin. The patient was submitted to multiple surgical drainages and started on vancomycin, rifampicin, and gentamycin. Due to persistence of fever and no microbiological clearance, linezolid was started with improvement. This is one of the few reported cases of severe invasive infection caused by CA-MRSA in Portugal, which was successfully treated with linezolid. In spite of the severity of infection, the MRSA isolate did not produce PVL.

scholarly journals Emergence of a new community acquired MRSA strain in Germany

2004 ◽  
Vol 9 (1) ◽  
pp. 16-18 ◽  
Author(s):  
W Witte ◽  
C Cuny ◽  
B Strommenger ◽  
C Braulke ◽  
D Heuck
Keyword(s):  
Staphylococcus Aureus ◽  
European Union ◽  
Fusidic Acid ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
The European Union ◽  
Molecular Pattern ◽  
Mrsa Strains ◽  
New Community ◽  
Panton Valentine Leukocidin ◽  
Valentine Leukocidin

Analysis of community-acquired methicillin-resistant Staphylococcus aureus (c-MRSA) from Germany producing the Panton-Valentine leukocidin revealed a unique SmaI-macrorestriction pattern, different from epidemic nosocomial strains. This molecular pattern corresponds to those shown in c-MRSA strains from other countries in the European Union. All isolates exhibited resistance to fusidic acid, which is coded by the far-1 gene. From data on geographical dissemination and time of occurrence, this strain appears to have emerged in Germany in the second half of 2002, and so an already wider dissemination is likely. The emergence of MRSA with resistance to fusidic acid is a first sign of the emergence of a PVL-positive MRSA clone.

scholarly journals Transcription of the phage-encoded Panton–Valentine leukocidin of Staphylococcus aureus is dependent on the phage life-cycle and on the host background

Microbiology ◽  
2009 ◽  
Vol 155 (11) ◽  
pp. 3491-3499 ◽  
Author(s):  
Christiane Wirtz ◽  
Wolfgang Witte ◽  
Christiane Wolz ◽  
Christiane Goerke
Keyword(s):  
Staphylococcus Aureus ◽  
Life Cycle ◽  
Mitomycin C ◽  
Fine Tuning ◽  
Strong Impact ◽  
Copy Numbers ◽  
Mrsa Strains ◽  
Native Host ◽  
Panton Valentine Leukocidin ◽  
Valentine Leukocidin

Panton-Valentine leukocidin (PVL) is a pore-forming, bi-component toxin secreted by Staphylococcus aureus strains epidemiologically associated with diseases such as necrotizing pneumonia and skin and soft-tissue infections. Here we demonstrate that transcription of the phage-encoded PVL (encoded in the luk-PV operon) is dependent on two major determinants: the phage life-cycle and the host chromosomal background. Mitomycin C induction of PVL-encoding prophages from different community-acquired MRSA strains led to an increase in the amount of luk-PV mRNA as a result of read-through transcription from latent phage promoters and an increase in phage copy numbers. Failing prophage excision was reflected in a constant expression of luk-PV as in the case of strain USA300, suggesting that φSa2USA300 is a replication-defective prophage. Additionally, we could show that luk-PV transcription is influenced by the S. aureus global virulence regulators agr and sae. We found a strong impact of the host background on prophage induction and replication when analysing PVL phages in different S. aureus strains. For example phage φSa2mw was greatly induced by mitomycin C in its native host MW2 and in strain Newman but to a considerably lesser extent in strains 8325-4, RN6390 and ISP479c. This discrepancy was not linked to the SOS response of the bacteria since recA transcription did not vary between the strains. These results suggest a fine tuning between certain phages and their host, with major impact on the expression of phage-encoded virulence genes.

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