An outbreak of livestock-associated meticillin-resistant Staphylococcus aureus (LA-MRSA) clonal complex 398 in a Regional Burns Centre

Author(s):  
Matthew James Stone ◽  
Claire Swales ◽  
Stuart Bond ◽  
Preetha Muthayya ◽  
Jayanta Biswa Sarma
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andi R. Sultan ◽  
Kirby R. Lattwein ◽  
Nicole A. Lemmens-den Toom ◽  
Susan V. Snijders ◽  
Klazina Kooiman ◽  
...  

AbstractStaphylococcus aureus biofilms are a major problem in modern healthcare due to their resistance to immune system defenses and antibiotic treatments. Certain analgesic agents are able to modulate S. aureus biofilm formation, but currently no evidence exists if paracetamol, often combined with antibiotic treatment, also has this effect. Therefore, we aimed to investigate if paracetamol can modulate S. aureus biofilm formation. Considering that certain regulatory pathways for biofilm formation and virulence factor production by S. aureus are linked, we further investigated the effect of paracetamol on immune modulator production. The in vitro biofilm mass of 21 S. aureus strains from 9 genetic backgrounds was measured in the presence of paracetamol. Based on biofilm mass quantity, we further investigated paracetamol-induced biofilm alterations using a bacterial viability assay combined with N-Acetylglucosamine staining. Isothermal microcalorimetry was used to monitor the effect of paracetamol on bacterial metabolism within biofilms and green fluorescent protein (GFP) promoter fusion technology for transcription of staphylococcal complement inhibitor (SCIN). Clinically relevant concentrations of paracetamol enhanced biofilm formation particularly among strains belonging to clonal complex 8 (CC8), but had minimal effect on S. aureus planktonic growth. The increase of biofilm mass can be attributed to the marked increase of N-Acetylglucosamine containing components of the extracellular matrix, presumably polysaccharide intercellular adhesion. Biofilms of RN6390A (CC8) showed a significant increase in the immune modulator SCIN transcription during co-incubation with low concentrations of paracetamol. Our data indicate that paracetamol can enhance biofilm formation. The clinical relevance needs to be further investigated.


2021 ◽  
Author(s):  
Lijuan Wang ◽  
Chen Sun ◽  
Suyun Qian ◽  
Yingchao Liu ◽  
Kaihu Yao ◽  
...  

Abstract Background. Methicillin-resistant Staphylococcus aureus (MRSA) Clonal Complex 59 (CC59) clone has spread among Chinese children, resulting in many Staphylococcus aureus infections. α-hemolysin (Hlα) is an important virulence factor of Staphylococcus aureus, but little research has been done on CC59 isolates with negative α-hemolysis. Results. During the 4 periods (2009-2011, 2012-2013, 2016, 2017), 291 MRSA isolates were collected. Isolates with β and δ hemolysis accounted for 60.47% among the MRSA isolates in 2009-2011; 56.41% in 2012-2013; 77.14% in 2016; and 56.25% in 2017. most ST59 isolates (94.38%), 9 ST338 isolates (100%) showed β and δ hemolysis, both ST59 and ST338 clone belong to CC59 clone. Twenty-two ST239 isolates (73.33%), 8 ST88 isolates (80%), 4 ST5 isolates (100%), 13 ST22 isolates (92.86%) and 6 ST398 isolates (85.71%) showed α and δ hemolysis. α hemolysin in most clinical isolates is highly conservative, each showed one amino acid locus variation, the most common mutation was threonine at position 275 instead of isoleucine, then glutamic acid replaced aspartic acid at 208. Seventeen ST59 and 2 ST338 isolates had no mutation, 3 ST59 isolates showed single mutation (C448G), and only one ST59 isolate showed multilocus mutation. Other ST typing, such as ST1, ST5, ST88, ST20, ST239 and ST398, all had multilocus mutations, sites were from 3 to 8, no conservative sequence was found among isolates with the same ST typing. The carrying rates of RNA III, Rot, agrA, SarR, SarU and SigB were all over 93%, the carrying rates of SarZ and SarA genes were 41.86% and 34.88% respectively. Trancriptional levels of hlα in isolates showed α and δ hemolysis and β and δ hemolysis were equal. USA300 and R23 produced Hlα, R23 didn’t showed α hemolysis phenotype.Conclusions. Most clinical CC59 isolates from children in China were α hemolysis negative. There was no statistically significant difference in hlα gene and RNA expression, they produced the protein. The reason for the phenotypic deletion probably related to β hemolysin (Hlβ).


2012 ◽  
Vol 140 (12) ◽  
pp. 2223-2232 ◽  
Author(s):  
A. RICHTER ◽  
R. STING ◽  
C. POPP ◽  
J. RAU ◽  
B.-A. TENHAGEN ◽  
...  

SUMMARYLivestock-associated methicillin-resistantStaphylococcus aureus(LA-MRSA) have been isolated from a number of livestock species and persons involved in animal production. We investigated the prevalence of LA-MRSA in fattening turkeys and people living on farms that house fattening turkeys. Eighteen (90%) of 20 investigated flocks were positive for MRSA, and on 12 of the farms 22 (37·3%) of 59 persons sampled were positive for MRSA. People with frequent access to the stables were more likely to be positive for MRSA. In most flocks MRSA that could be assigned to clonal complex (CC) 398 were detected. In five flocks MRSA ofspa-type t002 that is not related to CC398 were identified. Moreover, other methicillin-resistantStaphylococcusspp. were detected on 11 farms and in eight people working on the farms.


mSphere ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Jolene R. Bowers ◽  
Elizabeth M. Driebe ◽  
Valerie Albrecht ◽  
Linda K. McDougal ◽  
Mitchell Granade ◽  
...  

ABSTRACTStrains ofStaphylococcus aureusin clonal complex 8 (CC8), including USA300, USA500, and the Iberian clone, are prevalent pathogens in the United States, both inside and outside health care settings. Methods for typing CC8 strains are becoming obsolete as the strains evolve and diversify, and whole-genome sequencing has shown that some strain types fall into multiple sublineages within CC8. In this study, we attempt to clarify the strain nomenclature of CC8, classifying the major strain types based on whole-genome sequence phylogenetics using both methicillin-resistantS. aureus(MRSA) and methicillin-susceptibleS. aureus(MSSA) genomes. We show that isolates of the Archaic and Iberian clones from decades ago make up the most basal clade of the main CC8 lineages and that at least one successful lineage of CC8, made up mostly of MSSA, diverged before the other well-known strain types USA500 and USA300. We also show that the USA500 type includes two clades separated by the previously described “Canadian epidemic MRSA” strain CMRSA9, that one clade containing USA500 also contains the USA300 clade, and that the USA300-0114 strain type is not a monophyletic group. Additionally, we present a rapid, simple CC8 strain-typing scheme using real-time PCR assays that target single nucleotide polymorphisms (SNPs) derived from our CC8 phylogeny and show the significant benefit of using more stable genomic markers based on evolutionary lineages over traditionalS. aureustyping techniques. This more accurate and accessibleS. aureustyping system may improve surveillance and better inform the epidemiology of this very important pathogen.IMPORTANCEStaphylococcus aureusis a major human pathogen worldwide in both community and health care settings. Surveillance forS. aureusstrains is important to our understanding of their spread and to informing infection prevention and control. Confusion surrounding the strain nomenclature of one of the most prevalent lineages ofS. aureus, clonal complex 8 (CC8), and the imprecision of current tools for typingS. aureusmake surveillance and source tracing difficult and sometimes misleading. In this study, we clarify the CC8 strain designations and propose a new typing scheme for CC8 isolates that is rapid and easy to use. This typing scheme is based on relatively stable genomic markers, and we demonstrate its superiority over traditional typing techniques. This scheme has the potential to greatly improve epidemiological investigations ofS. aureus.


2019 ◽  
Vol 63 (11) ◽  
Author(s):  
Dokyun Kim ◽  
Jun Sung Hong ◽  
Eun-Jeong Yoon ◽  
Hyukmin Lee ◽  
Young Ah Kim ◽  
...  

ABSTRACT This study was performed to evaluate the clinical impacts of putative risk factors in patients with Staphylococcus aureus bloodstream infections (BSIs) through a prospective, multicenter, observational study. All 567 patients with S. aureus BSIs that occurred during a 1-year period in six general hospitals were included in this study. Host- and pathogen-related variables were investigated to determine risk factors for the early mortality of patients with S. aureus BSIs. The all-cause mortality rate was 15.0% (85/567) during the 4-week follow-up period from the initial blood culture, and 76.5% (65/85) of the mortality cases occurred within the first 2 weeks. One-quarter (26.8%, 152/567) of the S. aureus blood isolates carried the tst-1 gene, and most (86.2%, 131/152) of them were identified to be clonal complex 5 agr type 2 methicillin-resistant S. aureus (MRSA) strains harboring staphylococcal cassette chromosome mec type II, belonging to the New York/Japan epidemic clone. A multivariable logistic regression showed that the tst-1 positivity of the causative S. aureus isolates was associated with an increased 2-week mortality rate both in patients with S. aureus BSIs (adjusted odds ratio [aOR], 1.62; 95% confidence interval [CI], 0.90 to 2.88) and in patients with MRSA BSIs (aOR, 2.61; 95% CI, 1.19 to 6.03). Two host-related factors, an increased Pitt bacteremia score and advanced age, as well as a pathogen-related factor, carriage of tst-1 by causative MRSA isolates, were risk factors for 2-week mortality in patients with BSIs. Careful management of patients with BSIs caused by the New York/Japan epidemic clone is needed to improve clinical outcomes.


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