scholarly journals Methods of detection and typing of methicillin resistant Staphylococcus aureus isolated from animals

2014 ◽  
Vol 68 (1-2) ◽  
pp. 89-99
Author(s):  
V. Radosavljevic ◽  
Jadranka Zutic ◽  
Ljiljana Pavlovic ◽  
Tamara Boskovic ◽  
O. Radanovic ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Multiplex Pcr ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Simultaneous Detection ◽  
Latex Agglutination ◽  
Methicillin Resistant ◽  
Genotypic Identification ◽  
Spa Gene ◽  
Phenotypic Tests

In this work there was evaluated the method of detection of methicillin resistant Staphylococcus aureus (MRSA) by using two molecular and three phenotypic tests in investigation procedure of 70 strains of S.aureus isolated from animals. Recent findings of the new mecA homologue, mecALGA251, minimise the significance of mecA gene presence detection as a confirmation method of methicillin resistant Staphylococcus aureus identification. For this reason, along with multiplex PCR set of primers(165rDNK, nuc, mecA) for detection mecA gene, there was also used multiplex PCR set of primers (spa, mecA, pvl, mecALGA251) for differentiation mecALGA251 from mecA, with simultaneous detection of luk-PV and spa gene fragments. In all 70 investigated isolates there was detected the presence of specific 16 SrDNK fragment and nuc gene which encodes a thermostable S. aureus nuclease, while in 5 out of 70 S. aureus isolates, there was proven mecA gene presence using two multiplex PCR tests. In the investigated strains there was determined neither mecC (mecALGA251)gene presence, nor Panton Valentine Leukocidin encoding gene. By application cefoxitin disk-diffusion, latex-agglutination and two multiplex PCR tests, the identical results in identification 5 methicillin resistant out of 70 investigated S. aureus strains were obtained. In our investigation there was determined a complete correlation between the results of phenotypic and genotypic identification of methicillin resistant S. aureus.

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

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.

scholarly journals Prevalence of Panton-Valentine leukocidin genes in community-associated methicillin-resistant Staphylococcus aureus in the district of Pomoravlje

2016 ◽  
Vol 73 (3) ◽  
pp. 256-260 ◽  
Author(s):  
Ljiljana Petrovic-Jeremic ◽  
Nada Kuljic-Kapulica ◽  
Elizabeta Ristanovic ◽  
Dragana Josic ◽  
Zorica Lepsanovic
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clinical Laboratory ◽  
Meca Gene ◽  
Latex Agglutination ◽  
The Other ◽  
Methicillin Resistant ◽  
Standard Polymerase Chain Reaction ◽  
Panton Valentine Leukocidin ◽  
Valentine Leukocidin

Background/Aim. Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains appear to have rapidly disseminated among population in the community without established risk factors for MRSA worldwide. Panton-Valentine leukocidin (PVL) is a cytolytic toxin, encoded by the lukF-PV and lukF-PV genes. PVL may be the key toxin responsible for enhanced virulence of CA-MRSA. The aim of this study was to detect the genes encoding PVL in CA-MRSA isolates from healthy people from the District of Pomoravlje. Methods. We took throat and nose swabs from healthy, employed persons with mandatory sanitary examinations and analyzed the presence of MRSA, between January 2011 and December 2012 in the District of Pomoravlje. Susceptibility of isolated strains to cefoxitin was investigated by using disc diffusion according to the recommendation of CLSI (Clinical Laboratory Standard Institute), and by E test. The presence of penicillin-binding protein 2a (PBP2a) in Staphylococci was detected using latex agglutination Slidex ?MRSA Detection test. The gold standard, polymerase chain reaction (PCR) assay, was used for detection of mecA gene and PVL gene, and typing of SCCmec region. Results. Our investigation showed that staphylococcal carrier state was present in 2.58% of 52,910 throat and nasal swabs, and in 50 of them (3.67%) MRSA was isolated. Among these MRSA, 2 (4%) isolates were PVL-positive. Conclusion. The prevalence of CAMRSA and the presence of PVL gene among healthy, employed population in the District of Pomoravlje were low. The values obtained in this study show that, our region is not significantly different from the other parts of our country, nor from the other European countries.

scholarly journals Susceptibility and molecular characterization of mec A- and mec B-positive community acquired methicillin-resistant Staphylococcus aureus isolates from students

2021 ◽  
Vol 18 (2) ◽  
pp. 155-171
Author(s):  
Patrick O. Olorunfemi ◽  
Ndidi C. Ngwuluka ◽  
Josiah A. Onaolapo ◽  
Yakubu K.E. Ibrahim
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Molecular Characterization ◽  
Resistance Genes ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Public Health Importance ◽  
Methicillin Resistant ◽  
Spa Gene

Staphylococcus aureus is an organism of great public health importance. It is widely studied because it is virulent, causes life threatening disease and has ability to adapt to diverse environmental conditions and so develops resistance to antibiotics easily. As a result, there is a need for surveillance of its antibiotic resistance and resistance genes. The susceptibility and molecular characterization of methicillin resistant Staphylococcus aureus recovered from urine samples of healthy students were undertaken. Standard procedures were employed for isolation, identification, susceptibility, and polymerase chain reaction analyses. Out of 217 samples collected, 73 were confirmed Staphylococcus aureus. Most of the isolates were susceptible to ciprofloxacin and vancomycin followed by gentamicin and co-trimoxazole and least susceptible to penicillin, cefotaxime, ofloxacin and cefoxitin. Thirty-two (32) isolates were resistant to 5 antibiotics while 3 isolates were resistant to the 11 antibiotics used in this study. Sixteen phenotypically methicillin resistant isolates contained mecA gene while ten of the isolates also showed the presence of mecB gene. The characteristic Sa442 and nuc genes of Staphylococcus aureus and the presence of spa gene confirmed MRSA. Continous surveillance for antibiotic resistance and resistance genes is paramount at local, regional and national levels. Surveillance data will assist in implementing interventions. Keywords: Antibiotic resistance; Methicillin-resistant Staphylococcus aureus, mecA, mecB, CA-MRSA; Surveillance

scholarly journals Virulence Factors Found in Nasal Colonization and Infection of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates and Their Ability to Form a Biofilm

Toxins ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 14
Author(s):  
Thamiris Santana Machado ◽  
Felipe Ramos Pinheiro ◽  
Lialyz Soares Pereira Andre ◽  
Renata Freire Alves Pereira ◽  
Reginaldo Fernandes Correa ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Sccmec Type ◽  
Protein A ◽  
Invasive Infection ◽  
Type I ◽  
Methicillin Resistant ◽  
Type Iv ◽  
Spa Gene ◽  
The City

Hospitalizations related to Methicillin-resistant Staphylococcus aureus (MRSA) are frequent, increasing mortality and health costs. In this way, this study aimed to compare the genotypic and phenotypic characteristics of MRSA isolates that colonize and infect patients seen at two hospitals in the city of Niterói—Rio de Janeiro, Brazil. A total of 147 samples collected between March 2013 and December 2015 were phenotyped and genotyped to identify the protein A (SPA) gene, the mec staphylococcal chromosomal cassette (SCCmec), mecA, Panton-Valentine Leucocidin (PVL), icaC, icaR, ACME, and hla virulence genes. The strength of biofilm formation has also been exploited. The prevalence of SCCmec type IV (77.1%) was observed in the colonization group; however, in the invasive infection group, SCCmec type II was prevalent (62.9%). The Multilocus Sequence Typing (MLST), ST5/ST30, and ST5/ST239 analyses were the most frequent clones in colonization, and invasive infection isolates, respectively. Among the isolates selected to assess the ability to form a biofilm, 51.06% were classified as strong biofilm builders. Surprisingly, we observed that isolates other than the Brazilian Epidemic Clone (BEC) have appeared in Brazilian hospitals. The virulence profile has changed among these isolates since the ACME type I and II genes were also identified in this collection.

scholarly journals Mutation-Based Antibiotic Resistance Mechanism in Methicillin-Resistant Staphylococcus aureus Clinical Isolates

2021 ◽  
Vol 14 (5) ◽  
pp. 420
Author(s):  
Tanveer Ali ◽  
Abdul Basit ◽  
Asad Mustafa Karim ◽  
Jung-Hun Lee ◽  
Jeong-Ho Jeon ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Active Site ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Resistance Mechanism ◽  
Ligand Docking ◽  
Clinical Samples ◽  
Allosteric Site ◽  
Methicillin Resistant

β-Lactam antibiotics target penicillin-binding proteins and inhibit the synthesis of peptidoglycan, a crucial step in cell wall biosynthesis. Staphylococcus aureus acquires resistance against β-lactam antibiotics by producing a penicillin-binding protein 2a (PBP2a), encoded by the mecA gene. PBP2a participates in peptidoglycan biosynthesis and exhibits a poor affinity towards β-lactam antibiotics. The current study was performed to determine the diversity and the role of missense mutations of PBP2a in the antibiotic resistance mechanism. The methicillin-resistant Staphylococcus aureus (MRSA) isolates from clinical samples were identified using phenotypic and genotypic techniques. The highest frequency (60%, 18 out of 30) of MRSA was observed in wound specimens. Sequence variation analysis of the mecA gene showed four amino acid substitutions (i.e., E239K, E239R, G246E, and E447K). The E239R mutation was found to be novel. The protein-ligand docking results showed that the E239R mutation in the allosteric site of PBP2a induces conformational changes in the active site and, thus, hinders its interaction with cefoxitin. Therefore, the present report indicates that mutation in the allosteric site of PBP2a provides a more closed active site conformation than wide-type PBP2a and then causes the high-level resistance to cefoxitin.

Evaluation of antibiotic resistance pattern and mecA gene frequency in methicillin-resistant Staphylococcus aureus strains collected from clinical specimens in Marand hospital and treatment centers, Iran

2021 ◽  
Author(s):  
Abolfazl Jafari-Sales ◽  
Zahra Sadeghi Deylamdeh ◽  
Afsoon Shariat
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Medical Centers ◽  
Wide Range

Introduction: Staphylococcus aureus causes a wide range of infections and as a multivalent pathogen is one of the causative agents of nosocomial and community infections. Therefore, the aim of this study was to identify and determine the pattern of antibiotic resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients in hospitals and medical centers in Marand city and also to evaluate the presence of mecA gene. Materials and Methods: In this cross-sectional descriptive study, 385 samples of S. aureus were collected from different clinical samples of patients in hospitals and medical centers of Marand city. S. aureus was identified using standard biochemical methods.  Methicillin resistance was determined by disk diffusion method in the presence of oxacillin and cefoxitin. The pattern of antibiotic resistance of the strains was determined by disk diffusion method and according to CLSI recommendation and also PCR method was used to evaluate the frequency of MecA gene. Results: In the present study, out of 385 samples of S. aureus, 215 (55.84%) samples were methicillin resistant. PCR results for mecA gene showed that 110 samples had mecA gene.  The highest antibiotic resistance was observed against penicillin (100%) and erythromycin (83.63%). Most MRSA were isolated from urine and wound samples. Conclusion: The results of this study indicate the prevalence of methicillin-resistant species and also the increase in antibiotic resistance of MRSA to various antibiotics.  Therefore, in order to prevent increased resistance to other antibiotics, it is recommended to avoid inappropriate use of antibiotics.

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