Next-generation sequence (NGS) analysis reveals methicillin-resistance transfer to a methicillin-susceptible Staphylococcus aureus (MSSA) strain that subsequently caused a methicillin-resistant S. aureus (MRSA) outbreak

A bloodstream infection withStaphylococcus aureus, including methicillin-resistantS. aureus(MRSA), is a serious condition that carries a high mortality rate and is also associated with significant hospital costs. The rapid and accurate identification and differentiation of methicillin-susceptibleS. aureus(MSSA) and MRSA directly from positive blood cultures has demonstrated benefits in both patient outcome and cost-of-care metrics. We compare the next-generation Xpert MRSA/SA BC (Xpert) assay to the GeneOhm StaphSR (GeneOhm) assay for the identification and detection ofS. aureusand methicillin resistance in prospectively collected blood culture broths containing Gram-positive cocci. All results were compared to routine bacterial culture as the gold standard. Across 8 collection and test sites, the Xpert assay demonstrated a sensitivity of 99.6% (range, 96.4% to 100%) and a specificity of 99.5% (range, 98.0% to 100%) for identifyingS. aureus, as well as a sensitivity of 98.1% (range, 87.5% to 100%) and a specificity of 99.6% (range, 98.3% to 100%) for identifying MRSA. In comparison, the GeneOhm assay demonstrated a sensitivity of 99.2% (range, 95.2% to 100%) and a specificity of 96.5% (range, 89.2% to 100%) for identifyingS. aureus, as well as a sensitivity of 94.3% (range, 87.5% to 100%) and a specificity of 97.8% (range, 96.1% to 100%) for identifying MRSA. Five of six cultures falsely reported as negative for MRSA by the GeneOhm assay were correctly identified as positive by the Xpert assay, while one culture falsely reported as negative for MRSA by the Xpert assay was correctly reported as positive by the GeneOhm assay.

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Next-Generation Sequence Analysis Reveals Transfer of Methicillin Resistance to a Methicillin-Susceptible Staphylococcus aureus Strain That Subsequently Caused a Methicillin-Resistant Staphylococcus aureus Outbreak: a Descriptive Study

Journal of Clinical Microbiology ◽

10.1128/jcm.00459-17 ◽

2017 ◽

Vol 55 (9) ◽

pp. 2808-2816 ◽

Cited By ~ 2

Author(s):

Veronica Weterings ◽

Thijs Bosch ◽

Sandra Witteveen ◽

Fabian Landman ◽

Leo Schouls ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Genetic Distance ◽

Fusidic Acid ◽

Aureus Strain ◽

Snp Analysis ◽

Next Generation ◽

Mssa Isolate ◽

Methicillin Resistant ◽

Content Type ◽

Mssa Strain

ABSTRACT Resistance to methicillin in Staphylococcus aureus is caused primarily by the mecA gene, which is carried on a mobile genetic element, the staphylococcal cassette chromosome mec (SCC mec ). Horizontal transfer of this element is supposed to be an important factor in the emergence of new clones of methicillin-resistant Staphylococcus aureus (MRSA) but has been rarely observed in real time. In 2012, an outbreak occurred involving a health care worker (HCW) and three patients, all carrying a fusidic acid-resistant MRSA strain. The husband of the HCW was screened for MRSA carriage, but only a methicillin-susceptible S. aureus (MSSA) strain, which was also resistant to fusidic acid, was detected. Multiple-locus variable-number tandem-repeat analysis (MLVA) typing showed that both the MSSA and MRSA isolates were MT4053-MC0005. This finding led to the hypothesis that the MSSA strain acquired the SCC mec and subsequently caused an outbreak. To support this hypothesis, next-generation sequencing of the MSSA and MRSA isolates was performed. This study showed that the MSSA isolate clustered closely with the outbreak isolates based on whole-genome multilocus sequence typing and single-nucleotide polymorphism (SNP) analysis, with a genetic distance of 17 genes and 44 SNPs, respectively. Remarkably, there were relatively large differences in the mobile genetic elements in strains within and between individuals. The limited genetic distance between the MSSA and MRSA isolates in combination with a clear epidemiologic link supports the hypothesis that the MSSA isolate acquired a SCC mec and that the resulting MRSA strain caused an outbreak.

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The First Report of a Methicillin-Resistant Staphylococcus aureus Isolate Harboring Type IV SCCmec in Thailand

Pathogens ◽

10.3390/pathogens10040430 ◽

2021 ◽

Vol 10 (4) ◽

pp. 430

Author(s):

Wichai Santimaleeworagun ◽

Praewdow Preechachuawong ◽

Wandee Samret ◽

Tossawan Jitwasinkul

Keyword(s):

Staphylococcus Aureus ◽

Resistance Genes ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Sccmec Type ◽

Clinical Strain ◽

Spa Typing ◽

Methicillin Resistant ◽

Type Iv ◽

Antimicrobial Resistance Genes

Methicillin-resistant Staphylococcus aureus (MRSA) is mostly found in Thailand in the hospital as a nosocomial pathogen. This study aimed to report the genetic characterization of a clinical community-acquired MRSA (CA-MRSA) isolate collected from hospitalized patients in Thailand. Among 26 MRSA isolates, S. aureus no. S17 preliminarily displayed the presence of a staphylococcal cassette chromosome mec (SCCmec) type IV pattern. The bacterial genomic DNA was subjected to whole-genome sequencing. Panton–Valentine leukocidin (PVL) production, virulence toxins, and antibiotic resistance genes were identified, and multi-locus sequence typing (MLST) and spa typing were performed. The strain was matched by sequence to MLST type 2885 and spa type t13880. This strain carried type IV SCCmec with no PVL production. Five acquired antimicrobial resistance genes, namely blaZ, mecA, Inu(A), tet(K), and dfrG conferring resistance to β-lactams, lincosamides, tetracycline, and trimethoprim, were identified. The detected toxins were exfoliative toxin A, gamma-hemolysin, leukocidin D, and leukocidin E. Moreover, there were differences in seven regions in CR-MRSA no. S17 compared to CA-MRSA type 300. In summary, we have reported the ST2885-SCCmec IV CA-MRSA clinical strain in Thailand for the first time, highlighting the problem of methicillin resistance in community settings and the consideration in choosing appropriate antibiotic therapy.

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Fluoroquinolone- and Methicillin-Resistant Staphylococcus Aureus: Insights from the Antimicrobial Resistance Management Program

Journal of Pharmacy Technology ◽

10.1177/875512250502100302 ◽

2005 ◽

Vol 21 (3) ◽

pp. 123-128 ◽

Cited By ~ 2

Author(s):

John G Gums ◽

Benjamin J Epstein

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Methicillin Resistance ◽

Resistance Management ◽

Multidrug Resistant ◽

Management Program ◽

Methicillin Resistant ◽

The North ◽

The Us ◽

Northeast Us

Background: Staphylococcus aureus is a frequent cause of infections involving the bloodstream, skin and soft tissue, and lungs in hospitalized patients. These isolates are often multidrug resistant and represent a major therapeutic challenge. Objective: To explore the susceptibilities of S. aureus to nafcillin/oxacillin, a surrogate for methicillin resistance, and the fluoroquinolones and determine whether a relationship might exist between fluoroquinolone use and the prevalence of methicillin-resistant S. aureus (MRSA). Methods: To date, 353 institutions throughout the US and Puerto Rico have enrolled in the Antimicrobial Resistance Management (ARM) Program, and data have been submitted on nearly 5 million isolates of S. aureus. Isolates submitted from 1990 through 2002 were reviewed for sensitivity to nafcillin/oxacillin, clindamycin, erythromycin, and the fluoroquinolones ciprofloxacin and levofloxacin. Results: From 1990 through 2002 inclusive, susceptibility to nafcillin/oxacillin nationally was 64.9% (n = 360,460), ranging from 62.2% in the North Central and Northeast US to 72.8% in the Southwest. Nationally, S. aureus isolates were more resistant to levofloxacin (41.4%, n = 123,868) than ciprofloxacin (38.7%, n = 256,178). The greatest change in susceptibility of S. aureus to nafcillin/oxacillin and ciprofloxacin occurred concurrently from 1998 to 2002, which may implicate fluoroquinolone use with increasing rates of MRSA infection. Conclusions: Resistance to methicillin and the fluoroquinolones has increased in concert during the past 5 years. Collectively, data from the ARM Program, along with several other investigations, support a role of fluoroquinolone use in the emergence of MRSA. These observations, along with increasing resistance among gram-positive and gram-negative pathogens, underscore the need for judicious use of fluoroquinolones.

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Ceftobiprole Is Superior to Vancomycin, Daptomycin, and Linezolid for Treatment of Experimental Endocarditis in Rabbits Caused by Methicillin-Resistant Staphylococcus aureus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00886-09 ◽

2009 ◽

Vol 54 (2) ◽

pp. 610-613 ◽

Cited By ~ 24

Author(s):

P. Tattevin ◽

L. Basuino ◽

D. Bauer ◽

B. A. Diep ◽

H. F. Chambers

Keyword(s):

Staphylococcus Aureus ◽

Treatment Group ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Rabbit Model ◽

Laboratory Strain ◽

Penicillin Binding Protein ◽

Beta Lactam ◽

Methicillin Resistant ◽

High Affinity

ABSTRACT Beta lactam agents are the most active drugs for the treatment of streptococci and methicillin-susceptible Staphylococcus aureus endocarditis. However, methicillin-resistant S. aureus (MRSA) is resistant to all beta lactam agents licensed to date, and alternative treatments are limited. Ceftobiprole is a novel broad-spectrum cephalosporin that binds with high affinity to PBP 2a, the penicillin binding protein that mediates the methicillin resistance of staphylococci and is active against MRSA. Ceftobiprole was compared to vancomycin, daptomycin, and linezolid in a rabbit model of MRSA aortic valve endocarditis caused by the homogeneously methicillin-resistant laboratory strain COL. Residual organisms in vegetations were significantly fewer in ceftobiprole-treated rabbits than in any other treatment group (P < 0.05 for each comparison). In addition, the numbers of organisms in spleens and in kidneys were significantly lower in ceftobiprole-treated rabbits than in linezolid- and vancomycin-treated animals (P < 0.05 for each comparison). Anti-MRSA beta lactam agents such as ceftobiprole may represent a significant therapeutic advance over currently available agents for the treatment of MRSA endocarditis.

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Investigation of the antibiotic resistance of staphylococcus species isolated from foods

Élelmiszervizsgálati Közlemények ◽

10.52091/evik-2021/2-1-eng ◽

2021 ◽

Vol 67 (2) ◽

pp. 3372-3382

Author(s):

Brigitta Horváth ◽

Ferenc Peles ◽

Judit Gasparikné Reichardt ◽

Edit Pocklán ◽

Rita Sipos ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Methicillin Resistance ◽

Multidrug Resistant ◽

Farm Animals ◽

The European Union ◽

Methicillin Resistant ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Tof Ms

The presence of methicillin-resistant Staphylococcus aureus (MRSA) strains in the food chain has been confirmed by several studies in the European Union, but there are only limited data available in Hungary. The objective of the present study was to investigate the antibiotic resistance of Staphylococcus strains isolated from foods, using classical microbiological, molecular biological methods and the MALDI-TOF-MS technique, as well as the multi-locus sequence typing (MLST) of antibiotic resistant strains. During the study, 47 coagulase-positive (CPS) and 30 coagulase-negative (CNS) Staphylococcus isolates were collected. In the course of the MALDI-TOF-MS investigations, all CPS isolates (n=47) were found to be S. aureus species, while 8 different species were identified in the case of the CNS strains. Methicillin resistance was confirmed in two S. aureus strains, one of which had a sequence type not yet known, while the other MRSA strain was type ST398, which is the most common type of MRSA strain isolated from farm animals in the EU/EEA. (The abbreviation “MRSA” is often used in common parlance, but occasionally in the literature to denote “multidrug-resistant Staphylococcus aureus”. In the authors’ manuscript - the methicillin-resistant pathogen is correctly designated as such. Ed.)

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Methicillin-resistant Staphylococcus aureus bloodstream infection: risk factors and clinical outcome in non-intensive-care units

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/s0037-86822012000200010 ◽

2012 ◽

Vol 45 (2) ◽

pp. 189-193 ◽

Cited By ~ 4

Author(s):

Karinne Spirandelli Carvalho Naves ◽

Natália Vaz da Trindade ◽

Paulo Pinto Gontijo Filho

Keyword(s):

Risk Factors ◽

Staphylococcus Aureus ◽

Bloodstream Infection ◽

Antimicrobial Agents ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Diffusion Method ◽

Disk Diffusion Method ◽

Methicillin Resistant ◽

Staphylococcus Aureus Bloodstream Infection

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is spread out in hospitals across different regions of the world and is regarded as the major agent of nosocomial infections, causing infections such as skin and soft tissue pneumonia and sepsis. The aim of this study was to identify risk factors for methicillin-resistance in Staphylococcus aureus bloodstream infection (BSI) and the predictive factors for death. METHODS: A retrospective cohort of fifty-one patients presenting bacteraemia due to S. aureus between September 2006 and September 2008 was analysed. Staphylococcu aureus samples were obtained from blood cultures performed by clinical hospital microbiology laboratory from the Uberlândia Federal University. Methicillinresistance was determined by growth on oxacillin screen agar and antimicrobial susceptibility by means of the disk diffusion method. RESULTS: We found similar numbers of MRSA (56.8%) and methicillin-susceptible Staphylococcus aureus (MSSA) (43.2%) infections, and the overall hospital mortality ratio was 47%, predominantly in MRSA group (70.8% vs. 29.2%) (p=0.05). Age (p=0.02) was significantly higher in MRSA patients as also was the use of central venous catheter (p=0.02). The use of two or more antimicrobial agents (p=0.03) and the length of hospital stay prior to bacteraemia superior to seven days (p=0.006) were associated with mortality. High odds ratio value was observed in cardiopathy as comorbidity. CONCLUSIONS: Despite several risk factors associated with MRSA and MSSA infection, the use of two or more antimicrobial agents was the unique independent variable associated with mortality.

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IDENTIFICATION OF METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS USING TOUCHDOWN PCR AND PHENOTYPIC METHODS FROM PATIENTS AND HOSPITALS ENVIRONMENTS IN DIFFERENT IRAQI CITIES

IRAQI JOURNAL OF AGRICULTURAL SCIENCES ◽

10.36103/ijas.v52i6.1475 ◽

2021 ◽

Vol 52 (6) ◽

pp. 1356-1364

Author(s):

A. M. Abd Zaid ◽

N. J. Kandala

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Multidrug Resistant ◽

Sensitivity Test ◽

Methicillin Resistant ◽

Cultural Methods ◽

Base Medium ◽

Touchdown Pcr ◽

Phenotypic Methods

The study was aimed to evaluate the prevalence of MRSA in some Iraqi hospitals and determine the most powerful methods for identification of MRSA, in order to achieve the, 278 samples were collected from different hospitals in Iraq in various intervals, 204 out of 287 were identified as Staphylococcus aureus by conventional cultural methods and microscopic characteristics and 177 isolates are identified as MRSA by using HiCrome MeReSa Agar Base medium, but 154 of 177 (87%) isolates are methicillin resistance in sensitivity test. MRSA isolates were highly resistant to β-lactam antibiotics and considered multidrug resistant (MDR) in percent of (94.9%). Touchdown PCR used to identify the isolates, 97.05% were identified as Staphylococcus aureus, while 80.88% as MRSA.

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Detection of mecA gene by latex agglutination and its molecular analysis by PCR in methicillin resistant staphylococcus aureus.

The Professional Medical Journal ◽

10.29309/tpmj/2020.27.07.3752 ◽

2020 ◽

Vol 27 (07) ◽

pp. 1363-1370

Author(s):

Aneela Khawaja ◽

Iffat Javed ◽

Sohaila Mushtaq ◽

Saeed Anwar ◽

Faiqa Arshad ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Methicillin Resistance ◽

Meca Gene ◽

Latex Agglutination ◽

Medical Institute ◽

Cross Sectional ◽

Methicillin Resistant ◽

Agglutination Method ◽

Resistant Strains

Antimicrobial resistance (AMR) is a devastating question that is threatening the health globally. The extensive and indiscriminative use of antibiotics has evolved a notorious resistance in Staphylococcus aureus. This resistance developed through possession of mecA gene, which codes for modified penicillin binding protein (PBP2a) and the emergent strain being labeled “methicillin resistant Staphylococcus aureus”. Conventional phenotypic techniques for detection of MRSA rely on standardization of cultural characteristics. The drawbacks of diagnostic error to report MRSA include: poor prognosis, expensive treatment, dissemination of multi-drug resistant strains and even treatment failure. Latex agglutination method can be adopted as a more accurate and quick strategy for rapid detection of methicillin resistance. Objectives: To compare detection of mecA gene in methicillin resistant isolates of Staphylococcus aureus by latex agglutination and PCR; by assessing the sensitivity and specificity of both methods. Study Design: Descriptive Cross-Sectional study. Setting: Pathology Department, Post Graduate Medical Institute, Lahore. Period: From January 2015 to December 2015; according to standard operating procedures at Microbiology laboratory. Material & Methods: A total 713 consecutive, non-duplicate isolates of Staphylococcus aureus were processed. Methicillin resistance was determined using cefoxitin (30mg) by Kirby-Bauer method using CLSI guideline (2016), latex agglutination method; and PCR for mecA gene. Results: The results showed that out of 713 Staphylococcus aureus isolates, 92 (12.90%) isolates were resistant to cefoxitin and were labelled as MRSA. majority MRSA isolates recovered from pus (44.57%) and wound swab (20.65%), followed by blood (13.04%), fluid (8.70%), CSF (4.35%), CVP (3.26%), HVS (3.26%) and tracheal secretion (2.17%). By latex agglutination method, 87 (94.50%) were positive for PBP2a; while on PCR mecA gene was detected only in 82 (89.10%) MRSA isolates. When assessed with PCR (gold standard) the sensitivity and diagnostic accuracy of latex agglutination was 100% and 94.57%, respectively. Conclusion: Latex agglutination test can be employed as rapid and reliable diagnostic technique in MRSA isolates for mecA gene detection, where resources for molecular methods are inadequate. This can effectually lessen the misdiagnosis of resistant strains, and over/ ill-use of antibiotics.

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Prevalence of Methicillin Resistant and Virulence Determinants in Clinical Isolates of Staphylococcus aureus

The Open Infectious Diseases Journal ◽

10.2174/1874279301810010108 ◽

2018 ◽

Vol 10 (1) ◽

pp. 108-115

Author(s):

Manjunath Chavadi ◽

Rahul Narasanna ◽

Ashajyothi Chavan ◽

Ajay Kumar Oli ◽

Chandrakanth Kelmani. R

Keyword(s):

Staphylococcus Aureus ◽

Cell Morphology ◽

Methicillin Resistance ◽

Protein A ◽

Clinical Isolates ◽

Clinical Samples ◽

Virulence Determinants ◽

Methicillin Resistant ◽

Alternative Medicines ◽

Mrsa Strains

Introduction:Methicillin-resistantStaphylococcus aureus(MRSA) is the major threat that is a result of the uncontrolled use of antibiotics causing a huge loss in health, so understanding their prevalence is necessary as a public health measure.Objective:The aim of this study was to determine the prevalence of methicillin-resistant MRSA and virulence determinant among associatedS. aureusfrom the clinical samples obtained from various hospital and health care centers of the Gulbarga region in India.Materials and Methods:All the collected samples were subjected for the screening ofS. aureusand were further characterized by conventional and molecular methods including their antibiotic profiling. Further, the response of methicillin antibiotic on cell morphology was studied using scanning electron microscopy.Results:A total 126S. aureuswas isolated from the clinical samples which showed, 100% resistant to penicillin, 55.5% to oxacillin, 75.3% to ampicillin, 70.6% to streptomycin, 66.6% to gentamicin, 8.7% to vancomycin and 6.3% to teicoplanin. The selected MRSA strains were found to possessmecA(gene coding for penicillin-binding protein 2A) andfemA(factor essential for methicillin resistance)genetic determinants in their genome with virulence determinants such as Coagulase (coa) and the X region of the protein A (spa)gene. Further, the methicillin response in resistantS. aureusshowed to be enlarged and malformed on cell morphology.Conclusion:The molecular typing of clinical isolates ofS. aureusin this study was highly virulent and also resistant to methicillin; this will assist health professionals to control, exploration of alternative medicines and new approaches to combat Staphylococcal infections more efficiently by using targeted therapy.

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