scholarly journals Characterisation and Molecular Analysis of an Unusual Chimeric Methicillin Resistant Staphylococcus Aureus Strain and its Bacteriophages

2021 ◽  
Vol 12 ◽  
Author(s):  
Sindy Burgold-Voigt ◽  
Stefan Monecke ◽  
Alexandra Simbeck ◽  
Thomas Holzmann ◽  
Bärbel Kieninger ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Molecular Analysis ◽  
Large Scale ◽  
Antibiotic Resistance Genes ◽  
Attachment Site ◽  
Aureus Strain ◽  
African Countries ◽  
Hybrid Strain ◽  
Genomic Markers

In the context of microarray-based epidemiological typing of the clonal organism Staphylococcus aureus/MRSA, a strain was identified that did not belong to known clonal complexes. The molecular analysis by microarray-based typing yielded signals suggesting that it was a mosaic or hybrid strain of two lineages. To verify this result, the isolate was sequenced with both, short-read Illumina and long-read Nanopore technologies and analysed in detail. This supported the hypothesis that the genome of this strain, ST6610-MRSA-IVg comprised of segments originating from two different clonal complexes (CC). While the backbone of the strain’s genome, i.e., roughly 2 megabases, belongs to CC8, a continuous insert of 894 kb (approx. 30% of the genome) originated from CC140. Beside core genomic markers in the normal succession and orientation, this insert also included the mecA gene, coding for PbP2a and causing methicillin resistance, localised on an SCCmec IVg element. This particular SCCmec type was also previously observed in CC140 MRSA from African countries. A second conspicuous observation was the presence of the trimethoprim resistance gene dfrG within on a prophage that occupied an attachment site normally used by Panton-Valentine Leucocidin phages. This observation could indicate a role of large-scale chromosomal recombination in the evolution of S. aureus as well as a role of phages in the dissemination of antibiotic resistance genes.

scholarly journals The Phosphoarginine Phosphatase PtpB from Staphylococcus aureus Is Involved in Bacterial Stress Adaptation during Infection

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 645
Author(s):  
Mohamed Ibrahem Elhawy ◽  
Sylvaine Huc-Brandt ◽  
Linda Pätzold ◽  
Laila Gannoun-Zaki ◽  
Ahmed Mohamed Mostafa Abdrabou ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Staphylococcus Aureus ◽  
Treatment Strategies ◽  
Physiological Role ◽  
Aureus Strain ◽  
Stress Adaptation ◽  
Cellular Mechanisms ◽  
Host Interaction ◽  
Liver And Kidney

Staphylococcus aureus continues to be a public health threat, especially in hospital settings. Studies aimed at deciphering the molecular and cellular mechanisms that underlie pathogenesis, host adaptation, and virulence are required to develop effective treatment strategies. Numerous host-pathogen interactions were found to be dependent on phosphatases-mediated regulation. This study focused on the analysis of the role of the low-molecular weight phosphatase PtpB, in particular, during infection. Deletion of ptpB in S. aureus strain SA564 significantly reduced the capacity of the mutant to withstand intracellular killing by THP-1 macrophages. When injected into normoglycemic C57BL/6 mice, the SA564 ΔptpB mutant displayed markedly reduced bacterial loads in liver and kidney tissues in a murine S. aureus abscess model when compared to the wild type. We also observed that PtpB phosphatase-activity was sensitive to oxidative stress. Our quantitative transcript analyses revealed that PtpB affects the transcription of various genes involved in oxidative stress adaptation and infectivity. Thus, this study disclosed first insights into the physiological role of PtpB during host interaction allowing us to link phosphatase-dependent regulation to oxidative bacterial stress adaptation during infection.

scholarly journals Role of Staphylococcal Phage and SaPI Integrase in Intra- and Interspecies SaPI Transfer

2007 ◽  
Vol 189 (15) ◽  
pp. 5608-5616 ◽  
Author(s):  
Elisa Maiques ◽  
Carles Úbeda ◽  
María Ángeles Tormo ◽  
María Desamparados Ferrer ◽  
Íñigo Lasa ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Special Reference ◽  
Attachment Site ◽  
Pathogenicity Islands ◽  
Specific Attachment ◽  
Generalized Transduction

ABSTRACT SaPIbov2 is a member of the SaPI family of staphylococcal pathogenicity islands and is very closely related to SaPIbov1. Typically, certain temperate phages can induce excision and replication of one or more of these islands and can package them into special small phage-like particles commensurate with their genome sizes (referred to as the excision-replication-packaging [ERP] cycle). We have studied the phage-SaPI interaction in some depth using SaPIbov2, with special reference to the role of its integrase. We demonstrate here that SaPIbov2 can be induced to replicate by different staphylococcal phages. After replication, SaPIbov2 is efficiently encapsidated and transferred to recipient organisms, including different non-Staphylococcus aureus staphylococci, where it integrates at a SaPI-specific attachment site, attC , by means of a self-coded integrase (Int). Phages that cannot induce the SaPIbov2 ERP cycle can transfer the island by recA-dependent classical generalized transduction and can also transfer it by a novel mechanism that requires the expression of SaPIbov2 int in the recipient but not in the donor. It is suggested that this mechanism involves the encapsidation of standard transducing fragments containing the intact island followed by int-mediated excision, circularization, and integration in the recipient.

scholarly journals Influence of Metal-Resistant Staphylococcus aureus Strain K1 on the Alleviation of Chromium Stress in Wheat

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1354 ◽  
Author(s):  
Fanrong Zeng ◽  
Munazza Zahoor ◽  
Muhammad Waseem ◽  
Alia Anayat ◽  
Muhammad Rizwan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Staphylococcus Aureus ◽  
Anthropogenic Activities ◽  
Toxic Metal ◽  
Triticum Aestivum L ◽  
Aureus Strain ◽  
Peat Moss ◽  
Cr Toxicity ◽  
Living Organisms

Chromium (Cr) is recognized as a toxic metal that has detrimental effects on living organisms; notably, it is discharged into soil by various industries as a result of anthropogenic activities. Microbe-assisted phytoremediation is one of the most emergent and environmentally friendly methods used for the detoxification of pollutants. In this study, the alleviative role of Staphylococcus aureus strain K1 was evaluated in wheat (Triticum aestivum L.) under Cr stress. For this, various Cr concentrations (0, 25, 50 and 100 mg·kg−1) with and without peat-moss-based bacterial inoculum were applied in the soil. Results depicted that Cr stress reduced the plants’ growth by causing oxidative stress in the absence of S. aureus K1 inoculation. However, the application of S. aureus K1 regulated the plants’ growth and antioxidant enzymatic activities by reducing oxidative stress and Cr toxicity through conversion of Cr6+ to Cr3+. The Cr6+ uptake by wheat was significantly reduced in the S. aureus K1 inoculated plants. It can be concluded that the application of S. aureus K1 could be an effective approach to alleviate the Cr toxicity in wheat and probably in other cereals grown under Cr stress.

scholarly journals Rapid determination of hospital-acquired meticillin-resistant Staphylococcus aureus lineages

2007 ◽  
Vol 56 (5) ◽  
pp. 614-619 ◽  
Author(s):  
Joshua D. Cockfield ◽  
Smriti Pathak ◽  
Jonathan D. Edgeworth ◽  
Jodi A. Lindsay
Keyword(s):  
Staphylococcus Aureus ◽  
Large Scale ◽  
Rapid Determination ◽  
Control Strategies ◽  
Antibiotic Resistance Genes ◽  
Epidemiological Studies ◽  
Typing Methods ◽  
Mrsa Strains ◽  
Hospital Acquired

Multilocus sequence typing (MLST) and multi-strain microarray analysis have shown that most human Staphylococcus aureus strains belong to ten dominant clonal complexes (CCs) or lineages, each with unique surface architecture. Meticillin-resistant S. aureus (MRSA) strains currently belong to six of these lineages (CC1, CC5, CC8, CC22, CC30 and CC45), each of which has independently acquired mobile genetic elements (MGEs) carrying antibiotic resistance genes. MLST and microarrays are expensive and time consuming methods for routine determination of S. aureus lineage. A restriction-modification (RM) test has now been developed that is rapid, simple, inexpensive and accurately determines lineage of hospital-acquired MRSA. The RM test is based on three PCRs for hsdS gene variants, as hsdS genes likely control the independent evolution of S. aureus lineages. The RM test correctly identified 102 MRSA isolates as belonging to one of the six lineages/CCs. Real-time MRSA typing can be used to identify and track changes in local MRSA outbreaks, and provide support for targeting infection control strategies. Simple and accurate typing methods will also support large scale epidemiological studies, and could lead to greater understanding of the carriage, spread and virulence of different MRSA lineages.

Large-Scale Screening and Identification of Novel Pathogenic Staphylococcus aureus Genes Using a Silkworm Infection Model

2020 ◽  
Vol 221 (11) ◽  
pp. 1795-1804 ◽  
Author(s):  
Atmika Paudel ◽  
Hiroshi Hamamoto ◽  
Suresh Panthee ◽  
Yasuhiko Matsumoto ◽  
Kazuhisa Sekimizu
Keyword(s):  
Staphylococcus Aureus ◽  
Large Scale ◽  
Opportunistic Pathogen ◽  
Infection Model ◽  
Colony Forming Units ◽  
Screening And Identification ◽  
Transposon Mutants ◽  
Pathogenicity Tests ◽  
Large Scale Screening

Abstract The regulatory network of virulence factors produced by the opportunistic pathogen Staphylococcus aureus is unclear and the functions of many uncharacterized genes in its genome remain to be elucidated. In this study, we screened 380 genes whose function was unassigned, utilizing gene-disrupted transposon mutants of the community-acquired methicillin-resistant S. aureus USA300 for pathogenicity in silkworms. We identified 10 strains with reduced silkworm killing ability. Among them, 8 displayed reduced virulence in a mouse model as evidenced by reduced colony-forming units in organs of infected mice. The role of each gene in pathogenicity was further confirmed by complementation and pathogenicity tests in silkworms, where we found that the phenotype was not restored in 1 strain. Additionally, some of the mutants displayed reduced hemolysis, proteolysis, pigment production, and survival in murine RAW 264.7 monocyte-macrophage cells. These newly identified genes involved in virulence will enhance our understanding of the pathogenicity of S. aureus.

scholarly journals Results of challenge of goats with Staphylococcus aureus into the teat of the udder

2018 ◽  
Vol 67 (4) ◽  
pp. 237
Author(s):  
A. TZORA ◽  
C. VOIDAROU ◽  
A. KARAMOUTSIOS ◽  
J. SKOUFOS
Keyword(s):  
Staphylococcus Aureus ◽  
Protective Role ◽  
Aureus Strain ◽  
Dairy Herds ◽  
Cytological Examination ◽  
Lactating Goats ◽  
Before And After ◽  
Group A ◽  
Group B

Objective of the present study was to study the outcome of inoculation of Staphylococcus aureus into the teat duct of female goats, which simulates mammary natural infections. In total, 22 lactating goats were used in the study; 8 animals were challenged with a S. aureus strain at a depth of 2 mm into one teat duct (group A), 8 animals were challenged with the same strain at 6 mm into one teat duct (group B) and 6 animals were challenged directly into one gland cistern (group C). Challenge dose was always 1300 cfu. Animals were examined clinically before and after challenge; milk samples were collected for bacteriological and cytological examination, and milk yield measurements were also performed. Goats in group A or B developed a significantly milder response than animals in group C. It is concluded that the evidence indicates a protective role of the normal teat of the udder of goats and that the results also underline the significance of maintaining healthy teats for prevention of mastitis in dairy herds.

scholarly journals Molecular Characterization of Staphylococcus aureus Isolated from Human and Food Samples in Northern Algeria

Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1276
Author(s):  
Rachid Achek ◽  
Hosny El-Adawy ◽  
Helmut Hotzel ◽  
Ashraf Hendam ◽  
Herbert Tomaso ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Clinical Isolates ◽  
Aureus Strain ◽  
Clinical Samples ◽  
Accessory Gene ◽  
Northern Algeria ◽  
Food Matrices

Staphylococcus aureus is a commensal resident of the skin and nasal cavities of humans and can cause various infections. Some toxigenic strains can contaminate food matrices and cause foodborne intoxications. The present study aimed to provide relevant information (clonal complex lineages, agr types, virulence and antimicrobial resistance-associated genes) based on DNA microarray analyses as well as the origins and dissemination of several circulating clones of 60 Staphylococcus aureus isolated from food matrices (n = 24), clinical samples (n = 20), and nasal carriers (n = 16) in northern Algeria. Staphylococcus aureus were genotyped into 14 different clonal complexes. Out of 60 S. aureus, 13 and 10 isolates belonged to CC1-MSSA and CC97-MSSA, respectively. The CC 80-MRSA-IV was the predominant S. aureus strain in clinical isolates. The accessory gene regulator allele agr group III was mainly found among clinical isolates (70.4%). Panton–Valentine leukocidin genes lukF/lukS-PV were detected in 13.3% of isolates that all belonged to CC80-MRSA. The lukF/S-hlg, hlgA, and hla genes encoding for hemolysins and leucocidin components were detected in all Staphylococcusaureus isolates. Clinical and food isolates harbored more often the antibiotic resistance genes markers. Seventeen (28.3%) methicillin-resistant Staphylococcus aureus carrying the mecA gene localized on a SCCmec type IV element were identified. The penicillinase operon (blaZ/I/R) was found in 71.7% (43/60) of isolates. Food isolates belonging to CC97-MSSA carried several antibiotic resistance genes (blaZ, ermB, aphA3, sat, tetM, and tetK). The results of this study showed that all clones were found in their typical host, but interestingly, some nasal carriers had isolates assigned to CC705 thought to be absent in humans. The detection of MRSA strains among food isolates should be considered as a potential public health risk. Therefore, controlling the antibiotics prescription for a rational use in human and animal infections is mandatory.

scholarly journals Role of PknB Kinase in Antibiotic Resistance and Virulence in Community-Acquired Methicillin-Resistant Staphylococcus aureus Strain USA300

2010 ◽  
Vol 78 (8) ◽  
pp. 3637-3646 ◽  
Author(s):  
Sandeep Tamber ◽  
Joseph Schwartzman ◽  
Ambrose L. Cheung
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Antibiotic Resistance ◽  
Aureus Strain ◽  
Cell Wall Metabolism ◽  
Methicillin Resistant ◽  
Enhanced Sensitivity ◽  
Threonine Kinases

ABSTRACT The regulation of cellular processes by eukaryote-like serine/threonine kinases is widespread in bacteria. In the last 2 years, several studies have examined the role of serine/threonine kinases in Staphylococcus aureus on cell wall metabolism, autolysis, and virulence, mostly in S. aureus laboratory isolates in the 8325-4 lineage. In this study, we showed that the pknB gene (also called stk1) of methicillin-resistant S. aureus (MRSA) strain COL and the community-acquired MRSA (CA-MRSA) strain USA300 is involved in cell wall metabolism, with the pknB mutant exhibiting enhanced sensitivity to β-lactam antibiotics but not to other classes of antibiotics, including aminoglycosides, ciprofloxacin, bactrim, and other types of cell wall-active agents (e.g., vancomycin and bacitracin). Additionally, the pknB mutant of USA300 was found to be more resistant to Triton X-100-induced autolysis and also to lysis by lysostaphin. We also showed that pknB is a positive regulator of sigB activity, resulting in compromise in its response to heat and oxidative stresses. In association with reduced sigB activity, the expression levels of RNAII and RNAIII of agr and the downstream effector hla are upregulated while spa expression is downmodulated in the pknB mutant compared to the level in the parent. Consistent with an enhanced agr response in vitro, virulence studies of the pknB mutant of USA300 in a murine cutaneous model of infection showed that the mutant was more virulent than the parental strain. Collectively, our results have linked the pknB gene in CA-MRSA to antibiotic resistance, sigB activity, and virulence and have highlighted important differences in pknB phenotypes (virulence and sigB activity) between laboratory isolates and the prototypic CA-MRSA strain USA300.

Sign in / Sign up

Export Citation Format

Share Document