Characterization, Associated Risk Factors and Possible Treatment of Healthcare Associated Methicillin-Resistant Staphylococcus aureus (HA-MRSA) and Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) (original) (raw)
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Online Journal for Health and Allied Sciences, 2024
The global public health concern of Staphylococcus aureus (S. aureus) infection and its spread, particularly methicillin-resistant Staphylococcus aureus (MRSA), is exacerbated by the emergence of mec-genes, which are considered markers of MRSA. The study aims to isolate MRSA in clinical isolates and detect mec-genes using molecular assays, thereby enhancing infection control programmes. The study involved 381 clinical samples processed by standard laboratory procedures, and PCR was performed targeting the 16S rRNA gene as a reference and then with nuc-gene to detect Staphylococcus aureus. Further, MRSA was confirmed by PCR (polymerase chain reaction) amplification of S. aureus isolates by subtyping the mecA and mecC genes. The sensitivity and specificity of phenotypic methods were calculated using mecA gene PCR as the gold standard. In the present study, 65.85% of clinical isolates were found to have similar homology with Staphylococcus aureus. Uniplex PCR results showed that all 162 isolates with S. aureus-like phenotypes were detected as MRSA carrying the mecA gene, but none of them was found to carry the mecC gene for MRSA. The P-value for both methods was <0.001, which is considered to be highly significant in statistical analysis. The study found that PCR detection of nuc and mec genes is effectively identifies MRSA from clinical isolates, aiding in infection prevention and recommending its use for confirmatory testing. The study recommends using PCR as a confirmatory test method for MRSA detection to prevent the spread of resistant strains in hospitals and communities.
The aim of the present study is to examine the recovered strains of methicillinresistant Staphylococcus aureus (MRSA) phenotypically by conventional identification. Genotypicalexamination was made also by polymerase chain reaction (PCR) to detect the genes; lukF encoding Panton-Valentine Leukocidin(PVL) and arcA an indicator of the arginine catabolic mobile element (ACME).Twinty-eight strains of Staphylococcus aureus, collected in 2013 from three Saudi central hospitals, were characterized by streaking on Mannitol salt agar plates and biochemically identified as Staphylococcus aureus. Resistance towards eight antimicrobial agents revealed that most of the tested strains of Staphylococcus aureus showed resistance to the tested antimicrobials in the following order; Oxacillin 100%, Tetracycline 71%, Cefoxitin 71%, Erythromycin 71%, Ciprofloxacin 71%, Imipenem 68%, Amikacin 60% and Vancomycin 7 %. All the tested strains produced the gene arcA, while 80% showed the presence of lukF. Al-Talib, H. et al.., (2013): Rapid detection of methicillin-resistant Staphylococcus aureus by a newly developed dry reagent-based polymerase chain reaction assay, Journal of Microbiology, Immunology and Infection, http://dx.doi.org/10.1016/j.jmii.2013.06.004\. Baddour, M.; Abuelkheir, M. and Fatani, A. (2006): Trends in antibiotic susceptibility patterns and epidemiology of MRSA isolates from several hospitals in Riyadh, Saudi Arabia. Annals of Clinical Microbiology and Antimicrobials, 5: 30, 1-11. Bergan, T.; Bruun, J.N.; Digranes, A.; Lingaas, E.; Melby, K.K. and Sander, J. (1997): Susceptibility testing of bacteria and fungi. p. 251 illus.
BJSTR
Staphylococcus spp. it is one of the genera most frequently implicated in the etiology of hospital infections, especially in nosocomial wards. Staphylococcus aureus is one of the most frequently isolated pathogenic microorganisms in hospital infections, capable of causing septicemia and infections of the skin, respiratory system, and soft tissues. Furthermore, the spread of infections caused by the methicillin-resistant Staphylococcus aureus (MRSA) species is constantly increasing and is reaching worrying levels in various countries of the world, including Italy, in continuous and rapid expansion, even outside hospitals. In this study, strains of Staphylococcus with methicillin resistance in hospitalized patients were identified and characterized through a phenotypic and genotypic approach. In all the methicillin resistant strains analyzed, a high resistance to other classes of antibiotics tested was found, in accordance with the findings of the European Center for Disease Prevention and Control (CDC) and numerous studies at national and world level. On some isolated MRSA strains, a molecular epidemiological study was conducted to understand the origin and spread of circulating clones. All these have been identified by molecular approach aimed at genetic research and identification, by means of Multi Locus Sequence Typing (MLST), typing of the Staphylococcal Cassette Chromosome mec (SCCmec complex) and spa typing, typing of the repeated variable region of protein A. Using the MLST profile, 5 different clones of S. aureus were identified in several hospital departments, 4 of which already circulating in Italy and worldwide, while one is not yet reported in Italy. The application and deepening of these techniques have provided an overview of the spread and development of MRSA strains in the hospital setting.
Nepal Medical College Journal
Resistance shown by Staphylococcus aureus to methicillin; mediated by mecA, and vancomycin; mediated by vanA, has led to difficulty in treatment of related infections. Despite reports showing methicillin resistant S. aureus (MRSA) and vancomycin resistant S. aureus (VRSA) in Nepal, and need for their regular surveillance, no study has been conducted on it in our hospital. So, this study is aimed to determine prevalence of MRSA, VRSA and their molecular characterization along with antibiogram. A descriptive cross-sectional study was conducted from August to December, 2022 in Clinical Microbiology Laboratory of NMCTH among S. aureus (n=160) isolated from various clinical specimens after receiving ethical approval from NMC-IRC. AST was done by modified Kirby-Bauer’s disc diffusion method. MRSA and VRSA were detected by cefoxitin disc method and agar dilution method respectively. Inducible clindamycin resistance was detected by D-test. Resistant genes (mecA, PVL, and vanA) were detected...
Intisari Sains Medis
Background: Methicillin-Resistant Staphylococcus aureus (MRSA) is a big challenge for health services worldwide which causes infections both in healthcare and community. Healthcare-associated MRSA (HA-MRSA) strains are shown to be resistant to beta-lactam antibiotics and several non-beta lactam antibiotics. At the same time, the community-associated MRSA (CA-MRSA) tends to be resistant to beta-lactam antibiotics. MRSA carried staphylococcal cassette chromosome (SCCmec) types I, II, III, IV, and V. SCCmec types I, II, and III were predominantly found in HA-MRSA strain while SCCmec types IV and V predominantly found in CA-MRSA strains. Furthermore, the panton valentine leukocidine (pvl) gene is commonly found in CA-MRSA strains. Therefore, this study aimed to determine the prevalence of SCCmec types I, II, III, and pvl gene in MRSA isolated from clinical specimens in Sanglah General Hospital. Methods: This study was a cross-sectional descriptive study. MRSA was isolated from clinical...
Online journal of Health and Allied Sciences , 2024
Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) has been known as an infectious pathogen worldwide since 1960. The epidemiological distribution of MRSA may have shifted due to outbreaks reported from several nations, making it more challenging to differentiate among CA-MRSA and HA-MRSA. It is currently important to develop a strain-based explanation for HA and CA-MRSA due to its distinct epidemiology, genetic profile, antibiogram, and quantifiable features. The study aimed to distinguish CA and HA-MRSA by Staphylococcal Cassette Chromosome mec (SCCmec) typing. Materials and Method: The study involved a total of 381 S. aureus isolates, which were processed in the department of Microbiology, JSS Hospital, Mysore. All isolates were confirmed as MRSA, initially by disk diffusion method using cefoxitin 30µg and oxacillin 1μg disk and later by using PCR technique for the detection of mecA-gene. All mecA-gene positive samples were amplified for SCCmec typing by multiplex PCR for detection of SCCmec type I, II, III, IVa, IVb, IVc, IVd, V and XI respectively. Results: PCR confirmed a total of 66% isolates as mecA-positive MRSA. Multiplex PCR method revealed only 53% isolates were SCCmec-typeable. The mainstream of the isolates belonged to SCCmec type IV (53.48%) and type V (44.18%), followed by type III (9.30%), type II (3%) and type I (1.16%) respectively. The study also demonstrated the presence of multiple SCCmec types in 10.46% of MRSA isolates. Staphylococcal cassette chromosome recombinase (ccr) typing determined only 43% of isolates were typeable. Conclusion: The study found that hospital-associated SCCmec type IV and type V were the most circulating strains in our healthcare setting. The research identified a few MRSA isolates with diverse SCCmec types. The presence of CA-MRSA infection in in-patients and HA-MRSA infection in This work is licensed under a Creative Commons Attribution-No Derivative Works 2.5 India License
Journal of Genetic Engineering and Biotechnology, 2018
Methicillin-resistant Staphylococcus aureus (MRSA) has long been a common pathogen in healthcare facilities, but now, it has emerged as a problematic pathogen in the community setting as well. This study reported source, diagnosis and treatment of HA-MRSA and CA-MRSA. A total of sixty-five clinical samples (urine, pus, wound swab) were collected from clinical origin of Dhaka city, Bangladesh. All the isolates were tested phenotypically by conventional methods and genotypically by PCR targeting nuc, pvl and mecA genes. Finally sequencing was carried out for pvl gene to know the mutagenic variation or any amino acid changes in pvl gene. Chi square test was employed for statistical analysis. Patients of age group 51-60 years are more susceptible (46.15%) to MRSA, CA-MRSA or HA-MRSA infection. Female are (32.30%) more susceptible to MRSA infection. Among 65 isolates 53 isolates identified phenotypically as S. aureus. These were positive for amplification of nuc (270 bp) gene of S. aureus. Moreover, among 53 isolates 33 phenotypically considered as MRSA and 38 (72%) showed positive amplification for mecA (162 bp) gene. Among 38 MRSA isolates 22 (57.89%) confirmed as CA-MRSA and 16 (42.10%) as HA-MRSA. Finally, sequence analysis for lukS/F-PV genes from 4 representative isolates detected a new single nucleotide polymorphism in comparison with the control sequence. However, no amino acid changes were found. Statistical analysis showed HA-MRSA isolates were more commonly found in urine sample and CA-MRSA in pus and wound swab. CA-MRSA isolates were more resistant to tested antibiotics than HA-MRSA.
Background: The differentiation of Methicillin resistant Staphylococcus aureus (MRSA) strains from other strains of S. aureus has important implications for the treatment and management of patients with S. aureus infections. Detection of the mecA gene by PCR has been described as a rapid method for the identification of MRSA. Objectives: A molecular assay for the simultaneous detection of a Staphylococcus aureus-specific gene and the mecA gene, responsible for the resistance to methicillin in staphylococci, was evaluated. Methods: In a clinical study, 100 isolates of Staphylococcus aureus were investigated. Polymerase chain reaction (PCR) was used (with a Techne TC-5000 instrument-Bibby Scientific Ltd.) to amplify both the S. aureus specific sequence gene and mecA gene of 100 isolates with the amplicon size of 107 and 532bp. To accelerate the procedure of identification in clinical microbiology laboratories, simple and rapid method for DNA extraction directly from a single colony was employed. The assay included a rapid DNA extraction protocol conducted in 15 minutes and PCR conducted. The performance and robustness of the assay was evaluated with a control strain of methicillin susceptible Staphylococcus aureus-ATCC 25923 (MSSA). The specificity of the new molecular assay was tested with a bacterial strain of methicillin susceptible Staphylococcus aureus-ATCC 25923 (MSSA). Results: All clinical the isolates gave positive results for the S. aureus-specific genomic target, and only five isolates (5.0%) were positive for the mecA gene. Conclusion: The new rapid DNA extraction protocol was found to be quick, robust, and labor saving and it proved to be suitable for a routine molecular diagnostic laboratory. On the basis of this finding; establishment of molecular diagnostic laboratory in secondary and tertiary health units is urgently required.