scholarly journals Klasterisasi Staphylococcus aureus Resisten Neutrofil Berdasar Assesory Gene Regulator

2020 ◽  
Vol 38 (2) ◽  
pp. 95
Author(s):  
Christin Marganingsih Santosa ◽  
Fajar Budi Lestari ◽  
Rini Widayanti ◽  
Siti Isrina Oktavia Salasia
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Pcr Amplification ◽  
Aureus Strain ◽  
23S Rrna ◽  
Rrna Gene ◽  
Polymorphonuclear Cells ◽  
Biochemical Tests

Staphylococcus aureus is recognized worldwide as a major pathogen causing subclinical intramammary infections in dairy cows and food poisoning due to its ability to produce enterotoxin. The study aimed to identify enterotoxins of S. aureus and clustering the enterotoxins based on assessory gene regulator (agr). Virulence of S. aureus to the host was characterized based on the response of polymorphonuclear cells to the infection. Twelve S. aureus could be isolated from milk cows in central of dairy farming in Sumedang West Java. The identification of S. aureus was based on cultural and biochemical tests and an amplification of a specific section of the 23S rRNA gene. The sensitivity test against antibiotics revealed that some isolates of S. aureus were resistant to penicillin and methycillin. By PCR amplification one or more staphylococcal enterotoxin genes could be observed five genes in combinations of sea (216 bp), seb (478 bp), seh (375 bp), sei (576 bp), and sej (142 bp). Clustering of S. aureus based on the assesory gene regulator could be grouped into 4 clusters for agr1 (1 isolat), agr2 (2 isolates), in combination for agr1 and agr2 (1 isolate), and for non agr (2 isolates). Based on the response of polymorphonuclear cell in vitro and in vivo assays, revealed that S. aureus strain I-2 (agr1 cluster) and P1 (agr1+agr2 cluster) were more resistant to polymorphonuclear cells and could survive intracellularly, indicated that these strains could be used as proper candidates to develop dignostic tool based on agr against staphylococcal mastitis.  

scholarly journals Impacts of sarA and agr in Staphylococcus aureus Strain Newman on Fibronectin-Binding Protein A Gene Expression and Fibronectin Adherence Capacity In Vitro and in Experimental Infective Endocarditis

2004 ◽  
Vol 72 (3) ◽  
pp. 1832-1836 ◽  
Author(s):  
Yan-Qiong Xiong ◽  
Arnold S. Bayer ◽  
Michael R. Yeaman ◽  
Willem van Wamel ◽  
Adhar C. Manna ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Binding Capacity ◽  
Protein A ◽  
Aureus Strain ◽  
Global Regulators ◽  
Fibronectin Binding Protein ◽  
Regulatory Loci ◽  
Fibronectin Binding

ABSTRACT We investigated the impacts of sarA and agr on fnbA expression and fibronectin-binding capacity in Staphylococcus aureus in vitro and in experimental endocarditis. Although sarA up-regulated and agr down-regulated both fnbA expression and fibronectin binding in vitro and in vivo, fnbA expression was positively regulated in the absence of both global regulators. Thus, additional regulatory loci contribute to fnbA regulation and fibronectin-binding capacities in S. aureus.

scholarly journals Simulated Antibiotic Exposures in anIn VitroHollow-Fiber Infection Model Influence Toxin Gene Expression and Production in Community-Associated Methicillin-Resistant Staphylococcus aureus Strain MW2

2011 ◽  
Vol 56 (1) ◽  
pp. 140-147 ◽  
Author(s):  
Solen Pichereau ◽  
Madhulatha Pantrangi ◽  
William Couet ◽  
Cedric Badiou ◽  
Gerard Lina ◽  
...  
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Hollow Fiber ◽  
Aureus Strain ◽  
Enzyme Linked Immunosorbent Assay ◽  
Infection Model ◽  
Toxin Gene ◽  
Polymorphonuclear Cells ◽  
Methicillin Resistant

ABSTRACTCommunity-associated methicillin-resistantStaphylococcus aureus(CA-MRSA) strain MW2 harbors a plethora of toxins to mediate its virulence. However, toxin expression and regulation with simulated clinical antimicrobial exposures are unclear. This study evaluated these relationships using anin vitropharmacodynamic hollow-fiber infection model. Clinical doses of clindamycin, linezolid, minocycline, trimethoprim-sulfamethoxazole (SXT), and vancomycin were simulated over 72 h against MW2 in the hollow fiber model. Expression levels oflukSF-PVand enterotoxin genessec4,sek,seq, andsel2were quantified by real-time PCR. Panton-Valentine leukocidin (PVL) was quantified by enzyme-linked immunosorbent assay (ELISA), and cytotoxicity was determined on polymorphonuclear cells (PMNs). Vancomycin produced the maximum MW2 killing (2.53 log10CFU/ml) after the first dose, but the greatest sustained killing over 72 h occurred with linezolid and clindamycin. Vancomycin and minocycline induced gene upregulation from 0 to 8 h, followed by downregulation for the remaining simulation period. Clindamycin decreased gene expression in the first 24 h, followed by moderate increases (2.5-fold) thereafter. Linezolid increased gene expression 11.4- to 200.4-fold but inhibited PVL production (0.6 ± 0.3 versus 5.9 ± 0.2 μg/ml, linezolid versus control at 72 h;P< 0.05). Similar effects on PVL production occurred with clindamycin and minocycline. SXT increased PVL production at 48 h (2.8-fold) and 72 h (4.9-fold) of treatment (P< 0.05), resulting in increased PVL cytotoxicity on PMNs. Linezolid, clindamycin, and minocycline were the most effective agents on decreasing the virulence potential in CA-MRSA, notably after 8 h of treatment. SXT had minimal effects on toxin gene regulation, but it increased production and cytotoxicity of PVL toxin in the model and may enhance virulence when it is used to treat severe infections.

scholarly journals Linezolid-Resistant Staphylococcus aureus Strain 1128105, the First Known Clinical Isolate Possessing thecfrMultidrug Resistance Gene

2014 ◽  
Vol 58 (11) ◽  
pp. 6592-6598 ◽  
Author(s):  
Jeffrey B. Locke ◽  
Douglas E. Zuill ◽  
Caitlyn R. Scharn ◽  
Jennifer Deane ◽  
Daniel F. Sahm ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Gene ◽  
Ribosomal Subunit ◽  
Single Copy ◽  
Aureus Strain ◽  
23S Rrna ◽  
Surveillance Program ◽  
Rrna Gene ◽  
Multidrug Resistance Gene ◽  
Content Type

ABSTRACTThe Cfr methyltransferase confers resistance to six classes of drugs which target the peptidyl transferase center of the 50S ribosomal subunit, including some oxazolidinones, such as linezolid (LZD). The mobilecfrgene was identified in European veterinary isolates from the late 1990s, although the earliest report of a clinicalcfr-positive strain was the 2005 Colombian methicillin-resistantStaphylococcus aureus(MRSA) isolate CM05. Here, through retrospective analysis of LZDrclinical strains from a U.S. surveillance program, we identified acfr-positive MRSA isolate, 1128105, from January 2005, predating CM05 by 5 months. Molecular typing of 1128105 revealed a unique pulsed-field gel electrophoresis (PFGE) profile most similar to that of USA100,spatype t002, and multilocus sequence type 5 (ST5). In addition tocfr, LZD resistance in 1128105 is partially attributed to the presence of a single copy of the 23S rRNA gene mutation T2500A. Transformation of the ∼37-kb conjugative p1128105cfr-bearing plasmid from 1128105 intoS. aureusATCC 29213 background strains was successful in recapitulating the Cfr antibiogram, as well as resistance to aminoglycosides and trimethoprim. A 7-kbcfr-containing region of p1128105 possessed sequence nearly identical to that found in the Chinese veterinaryProteus vulgarisisolate PV-01 and in U.S. clinicalS. aureusisolate 1900, although the presence of IS431-like sequences is unique to p1128105. Thecfrgene environment in this early clinicalcfr-positive isolate has now been identified in Gram-positive and Gram-negative strains of clinical and veterinary origin and has been associated with multiple mobile elements, highlighting the versatility of this multidrug resistance gene and its potential for further dissemination.

scholarly journals NorB, an Efflux Pump in Staphylococcus aureus Strain MW2, Contributes to Bacterial Fitness in Abscesses

2008 ◽  
Vol 190 (21) ◽  
pp. 7123-7129 ◽  
Author(s):  
Yanpeng Ding ◽  
Yoshikuni Onodera ◽  
Jean C. Lee ◽  
David C. Hooper
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Single Copy ◽  
Aureus Strain ◽  
Bacterial Survival ◽  
Bacterial Fitness

ABSTRACT While remaining a major problem in hospitals, Staphylococcus aureus is now spreading in communities. Strain MW2 (USA400 lineage) and other community methicillin-resistant S. aureus strains most commonly cause skin infections with abscess formation. Multidrug resistance (MDR) efflux pumps contribute to antimicrobial resistance but may also contribute to bacterial survival by removal of environmental toxins. In S. aureus, NorA, NorB, NorC, and Tet38 are chromosomally encoded efflux pumps whose overexpression can confer MDR to quinolones and other compounds (Nor pumps) or tetracyclines alone (Tet38), but the natural substrates of these pumps are not known. To determine the role of these efflux pumps in a natural environment in the absence of antibiotics, we used strain MW2 in a mouse subcutaneous abscess model and compared pump gene expression as determined by reverse transcription-PCR in the abscesses and in vitro. norB and tet38 were selectively upregulated in vivo more than 171- and 24-fold, respectively, whereas norA and norC were downregulated. These changes were associated with an increase in expression of mgrA, which encodes a transcriptional regulator known to affect pump gene expression. In competition experiments using equal inocula of a norB or tet38 mutant and parent strain MW2, each mutant exhibited growth defects of about two- to threefold in vivo. In complementation experiments, a single-copy insertion of norB (but not a single-copy insertion of tet38) in the attB site within geh restored the growth fitness of the norB mutant in vivo. Our findings indicate that some MDR pumps, like NorB, can facilitate bacterial survival when they are overexpressed in a staphylococcal abscess and may contribute to the relative resistance of abscesses to antimicrobial therapy, thus linking bacterial fitness and resistance in vivo.

scholarly journals Isolation and characterisation of virulent Serratia marcescens associated with a disease outbreak in farmed ornamental fish, Poecilia reticulata in Kerala, India

2017 ◽  
Vol 64 (4) ◽  
Author(s):  
Arathi Dharmaratnam ◽  
Raj Kumar ◽  
V. S. Basheer ◽  
Neeraj Sood ◽  
T. Raja Swaminathan ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Poecilia Reticulata ◽  
Multiple Drug Resistance ◽  
Clinical Signs ◽  
Ornamental Fish ◽  
Multiple Drug ◽  
Rrna Gene ◽  
Biochemical Tests

Pathogenic strain of Serratia marcescens (NPSM-1) with multiple drug resistance was isolated from guppy Poecilia reticulata with clinical signs of fin rot and was confirmed by biochemical tests and 16S rRNA gene sequencing. The extra cellular proteins (ECP) of the bacteria exhibited marked cytotoxic activity in vitro on Cyprinus carpio koi fin (CCKF) cell line. The in vivo challenge studies confirmed that the isolate was highly pathogenic to fish when the fishes were injected with1 x 104 CFU/fish and the same bacterium was re-isolated from infected fish, post-challenge. S. marcescens produced large zones of haemolysis on 10% sheep blood agar. The bacteria was found to carry virulence genes; extracellular metalloprotease gene (Pr596) and AHL synthase gene (SpnI). The bacterial isolate was tested to determine sensitivity against 16 antibiotics and was sensitive to only 5 viz., cefixime, chloramphenicol, ciprofloxacin, gentamycin and erythromycin. The study indicates that S. marcescens can cause disease in ornamental fish and the bacterium being a known human pathogen, may also cause infections in humans having direct contact with infected fishes. This is the first report describing S. marcescens as a pathogen of freshwater ornamental fish in India.

scholarly journals Improved Multiplex Polymerase Chain Reaction for Rapid Staphylococcus Aureus Detection in Meat and Milk Matrices

2016 ◽  
Vol 15 (1) ◽  
pp. 65-76
Author(s):  
Zuzana Šramková ◽  
Barbora Vidová ◽  
Andrej Godány
Keyword(s):  
Staphylococcus Aureus ◽  
Polymerase Chain Reaction ◽  
Food Poisoning ◽  
Detection Sensitivity ◽  
23S Rrna ◽  
Rrna Gene ◽  
Chain Reaction ◽  
23S Rrna Gene ◽  
Polymerase Chain ◽  
Toxic Shock Syndrome Toxin

Abstract Staphylococcal food poisoning represents one of the most frequently occurring intoxications, caused by staphylococcal enterotoxins (SE-s) and staphylococcal enterotoxin-like proteins (SEl-s). Therefore, there is a need for rapid, sensitive and specific detection method for this human pathogen and its toxin genes in food matrices. The present work is focused on Staphylococcus aureus detection by a nonaplex polymerase chain reaction, which targets the 23S rRNA gene for identification of S. aureus at the species level, genes for classical SE-s (SEA, SEC, SED), new SE-s (SEH, SEI), SEl-s (SEK, SEL) and tsst-1 gene (toxic shock syndrome toxin). Primers were properly designed to avoid undesirable interactions and to create a reliably identifiable profile of amplicons when visualized in agarose gel. According to obtained results, this approach is able to reach the detection sensitivity of 12 colony forming units from milk and meat matrices without prior culturing and DNA extraction.

Characterization of Staphylococcus aureus Isolates from White-Brined Urfa Cheese

2011 ◽  
Vol 74 (11) ◽  
pp. 1788-1796 ◽  
Author(s):  
KURSAT KAV ◽  
RAMAZAN COL ◽  
MUSTAFA ARDIC
Keyword(s):  
Staphylococcus Aureus ◽  
Tandem Repeats ◽  
Genetic Relatedness ◽  
Food Poisoning ◽  
Rflp Analysis ◽  
23S Rrna ◽  
Enzyme Linked Immunosorbent Assay ◽  
Toxin Gene ◽  
Rrna Gene ◽  
23S Rrna Gene

The aim of this study was to investigate the presence of Staphylococcus aureus and staphylococcal enterotoxin (SE) genes in Urfa cheese samples and to characterize the enterotoxigenic potential of these isolates. From a total of 127 Urfa cheese samples, 53 isolates (from 41.7% of the samples) were identified by a species-specific PCR assay as S. aureus. Of these isolates, 40 (75.5%) gave positive PCR results for the 3′ end of the coa gene. The coa-positive S. aureus strains were characterized for their population levels and enterotoxigenic properties, including slime factor, β-lactamase, antibiotic susceptibilities, production of the classical SEs (SEA through SEE), in both cheese and liquid cultures by enzyme-linked immunosorbent assay (ELISA) and for the presence of specific genes, including classical SE genes (sea through see), mecA, femA, and spa, by PCR. The genetic relatedness among the coa-positive S. aureus isolates was investigated by PCR-based restriction fragment length polymorphism (RFLP) analysis and the 23S rRNA gene spacer. The 23S rRNA gene spacer and coa RFLP analysis using AluI and Hin6I revealed 14 different patterns. SEB, SEC, and SEA and SEE were detected by ELISA in three cheese samples. Fourteen S. aureus strains harbored enterotoxin genes sea through see, and three strains carried multiple toxin genes. The most commonly detected toxin gene was sec (25% of tested strains). Of the 40 analyzed S. aureus strains, 3 (7.5%) were mecA positive. Based on tandem repeats, four coa and spa types were identified. The results of this study indicate that S. aureus and SEs are present at significant levels in Urfa cheese. These toxins can cause staphylococcal food poisoning, creating a serious hazard for public health.

scholarly journals Mechanisms of fluoroquinolone resistance in genetically related strains of Staphylococcus aureus.

1997 ◽  
Vol 41 (12) ◽  
pp. 2733-2737 ◽  
Author(s):  
G W Kaatz ◽  
S M Seo
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Mechanisms ◽  
Single Step ◽  
Fluoroquinolone Resistance ◽  
Aureus Strain ◽  
Topoisomerase Iv ◽  
Single Strain ◽  
Derivatives Of

Fluoroquinolone resistance in Staphylococcus aureus results from amino acid substitutions at particular locations in the DNA gyrase A and B subunits as well as in the topoisomerase IV A subunit and from NorA-mediated efflux. More than one resistance mechanism may be present in a single strain. Fluoroquinolone-resistant derivatives of SA-1199, a methicillin-susceptible S. aureus strain, were selected in vivo or in vitro, and their mechanisms of fluoroquinolone resistance were identified. We found that many of the resistance mechanisms described above can develop in derivatives of a single parent strain, either singly or in combination, and can arise in a single step. Variances in MICs for strains with the same apparent resistance mechanisms likely are due to the presence of new or undetected but established means of fluoroquinolone resistance. NorA-mediated resistance can occur in the apparent absence of topoisomerase mutations and in some strains may be the result of a promoter region mutation causing increased expression of norA. However, increased expression of norA can occur independently of this mutation, suggesting that a regulatory locus for this gene exists elsewhere on the chromosome.

scholarly journals Effect of Macrolide Usage on Emergence of Erythromycin-Resistant Campylobacter Isolates in Chickens

2007 ◽  
Vol 51 (5) ◽  
pp. 1678-1686 ◽  
Author(s):  
Jun Lin ◽  
Meiguan Yan ◽  
Orhan Sahin ◽  
Sonia Pereira ◽  
Yun-Juan Chang ◽  
...  
Keyword(s):  
Prolonged Exposure ◽  
Efflux Pump ◽  
Spontaneous Mutation ◽  
23S Rrna ◽  
Rrna Gene ◽  
Campylobacter Coli ◽  
Growth Promoter ◽  
23S Rrna Gene

ABSTRACT In this work we conducted both in vitro and in vivo experiments to examine the development and mechanisms of erythromycin (Ery) resistance in Campylobacter jejuni and Campylobacter coli. In vitro plating revealed that both Campylobacter species had similar but low spontaneous mutation frequencies (3 × 10−9 to <5.41 × 10−10) for Ery resistance. Chickens infected with C. jejuni or C. coli were subjected to single or multiple treatments with medicated water containing tylosin (0.53 g/liter), which transiently reduced the level of Campylobacter colonization but did not select for Ery-resistant (Eryr) mutants in the treated birds. However, when tylosin was given to the chickens in feed at a growth-promoting dose (0.05 g/kg feed), Eryr mutants emerged in the birds after prolonged exposure to the antibiotic. The vast majority of the in vitro- and in vivo-selected Campylobacter mutants with Ery MICs of 8 to 256 μg/ml lacked the known resistance-associated mutations in the 23S rRNA gene, while the highly resistant mutants (Ery MIC > 512 μg/ml) had the A2074G mutation in the 23S rRNA gene. Inactivation of CmeABC, a multidrug efflux pump, dramatically reduced the Ery MIC in all of the examined mutants regardless of the presence of the A2074G mutation. Together, these results reveal distinct features associated with Ery resistance development in Campylobacter, demonstrate the significant role of CmeABC in Ery resistance, and suggest that long-term use of a macrolide as a growth promoter selects for the emergence of Eryr Campylobacter in animal reservoirs.

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