Assessment of Chromosome Cassette Pattern of MRSA in Correlation to Coagulase Gene

The resistance of methicillin-resistant staphylococcus aureus (MRSA) to antimicrobials drugs is due to expression of the mecA gene. Current study was conducted on 33 MRSA clinical samples (Cefotaxime and Oxacillin positive). All MRSA isolates were examined using Antibiogram, Minimum Inhibitory concentration (MIC) and PCR to clarify the expression of SCCmec genes and to detect the differences on repeats of coagulase gene (Coa). Results showed that all isolates were 100% resistant against Amoxycillin-clavulanate, Ampicillin and Cefotaxime, 45.5% were resistant against Ciprofloxacin and erythromycin. mecA gene is expressed in all examined isolates (100%). The expression of SCCmec genes showed that 11.11% expressed type I, 45.45% contained type II, 45.45% contained type III, 63.63% were type IV and 5.55% were typeV. All examined isolates harbored and expressed coagulase gene repeats. Coagulase repeats were 27.27% with 5 repeats (81pb), and 72.72% with 4 repeats. In conclusion, the virulence of MRSA strains is increased and gave different antibiogram activities from different global regions and the repeats of Coa gene give no detectable differences among MRSA strains.

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Distribution of Virulence Genes Among Methicillin-resistant Staphylococcus Aureus of Clinical and Environmental Origin

10.21203/rs.3.rs-87157/v1 ◽

2020 ◽

Author(s):

Deepshikha Bhowmik ◽

Shiela Chetri ◽

Bhaskar Jyoti Das ◽

Debadatta Dhar Chanda ◽

Amitabha Bhattacharjee

Keyword(s):

Staphylococcus Aureus ◽

Multidrug Resistance ◽

Virulence Genes ◽

Methicillin Resistant Staphylococcus Aureus ◽

Virulence Gene ◽

Type I ◽

Type Ii ◽

Methicillin Resistant ◽

Type Iv ◽

Type V

Abstract Objective: This study was designed to discover the dissemination of virulence genes in Methicillin-resistant Staphylococcus aureus from clinical and environmental settings. Results: The virulence gene such as sea (n=54), seb (n=21), eta (n=27), etb (n=2), cna (n=24), ica (n=2) and tst (n=30) was revealed from this study. Different SCCmec types such as type I, type II, type III, type IV, type V, type VI, type VII, type VIII and type XII were detected among sixty three MRSA isolates where SCCmec type II having ST1551 and type V with ST2416 were found to be associated with multidrug resistance and were highly prevalent in the study area.

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

Toxins ◽

10.3390/toxins13010014 ◽

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.

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

Pharmaceuticals ◽

10.3390/ph14050420 ◽

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.

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Distribution of virulence genes and SCCmec types among methicillin-resistant Staphylococcus aureus of clinical and environmental origin: a study from community of Assam, India

BMC Research Notes ◽

10.1186/s13104-021-05473-3 ◽

2021 ◽

Vol 14 (1) ◽

Cited By ~ 1

Author(s):

Deepshikha Bhowmik ◽

Shiela Chetri ◽

Bhaskar Jyoti Das ◽

Debadatta Dhar Chanda ◽

Amitabha Bhattacharjee

Keyword(s):

Staphylococcus Aureus ◽

Virulence Genes ◽

Methicillin Resistant Staphylococcus Aureus ◽

Virulence Gene ◽

Type I ◽

Methicillin Resistant ◽

Type Iv ◽

Clinical Community ◽

Type V ◽

Sccmec Types

Abstract Objective This study was designed to discover the dissemination of virulence genes in Methicillin-resistant Staphylococcus aureus from clinical, community and environmental settings. Results This study includes 1165 isolates collected from hospital, community and environmental settings. Among them sixty three were confirmed as MRSA with varied SCCmec types viz; type I, type II, type III, type IV, type V, type VI, type VII, type VIII and type XII. The virulence gene such as sea (n = 54), seb (n = 21), eta (n = 27), etb (n = 2), cna (n = 24), ica (n = 2) and tst (n = 30) was also revealed from this study. The study underscores coexistence of resistance cassette and virulence genes among clinical and environment isolates which is first of its kind from this part of the world.

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Methicillin Resistant Staphylococcus aureus: Prevalence And Antibiogram In A Tertiary Care Hospital in Western Nepal

The Journal of Infection in Developing Countries ◽

10.3855/jidc.86 ◽

2009 ◽

Vol 3 (09) ◽

pp. 681-684 ◽

Cited By ~ 31

Author(s):

Hare Krishna Tiwari ◽

Ayan Kumar Das ◽

Darshan Sapkota ◽

Kunjukunju Sivrajan ◽

Vijay Kumar Pahwa

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Inhibitory Concentration ◽

Tertiary Care ◽

Care Hospital ◽

Methicillin Resistant ◽

Mrsa Strains ◽

Susceptibility Tests ◽

Rational Use Of Antibiotics ◽

Hospital Acquired

Background: Methicillin resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial and community infections. Its prevalence varies with country and with hospitals within a country. The current study estimates the prevalence of MRSA strains and investigates their antibiogram in western Nepal. Methodology: A total of 162 S. aureus strains were isolated from various clinical specimens, and antibiotic susceptibility tests were performed using disc diffusion, growth on oxacillin screen agar, and oxacillin minimum inhibitory concentration (MIC). Results: One hundred and twelve (69.1%) strains were found to be MRSA, of which 37 (33.1%) were community acquired and 75 (66.9%) were hospital acquired. Of 112 MRSA strains, 45 (40.1%) were multi-drug resistant. All MRSA strains were found resistant to penicillin, and 91.9%, 87.4%, 77%, and 55.5% were resistant to amoxicillin, ampicillin, trimethoprim/sulfamethoxazole, and cephalexin, respectively. However, low resistance was observed with amikacin (19%), ciprofloxacin (26.5%), and norfloxacin (30.6%). All strains were sensitive to vancomycin. Conclusion: The reported rate of MRSA prevalence is alarming. Given the ability of MRSA to spread from person to person, it is necessary to adhere to rational use of antibiotics and to raise awareness among the concerned communities and tourists who visit this area.

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Synthesis and Antimicrobial Studies of Coumarin-Substituted Pyrazole Derivatives as Potent Anti-Staphylococcus aureus Agents

Molecules ◽

10.3390/molecules25122758 ◽

2020 ◽

Vol 25 (12) ◽

pp. 2758 ◽

Cited By ~ 3

Author(s):

Rawan Alnufaie ◽

Hansa Raj KC ◽

Nickolas Alsup ◽

Jedidiah Whitt ◽

Steven Andrew Chambers ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Minimum Inhibitory Concentration ◽

Methicillin Resistant Staphylococcus Aureus ◽

Inhibitory Concentration ◽

Fatality Rate ◽

Pyrazole Derivatives ◽

Methicillin Resistant ◽

Antimicrobial Studies ◽

Mrsa Strains

In this paper, synthesis and antimicrobial studies of 31 novel coumarin-substituted pyrazole derivatives are reported. Some of these compounds have shown potent activity against methicillin-resistant Staphylococcus aureus (MRSA) with minimum inhibitory concentration (MIC) as low as 3.125 µg/mL. These molecules are equally potent at inhibiting the development of MRSA biofilm and the destruction of preformed biofilm. These results are very significant as MRSA strains have emerged as one of the most menacing pathogens of humans and this bacterium is bypassing HIV in terms of fatality rate.

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554. The Changing Epidemiology of Methicillin-Resistant Staphylococcus aureus Causing Bacteremia in Hiroshima, Japan During 2008–2017

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.623 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S263-S263

Author(s):

Hiroki Kitagawa ◽

Junzo Hisatsune ◽

Hiroki Ohge ◽

Motoyuki Sugai

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Sccmec Type ◽

University Hospital ◽

Methicillin Resistant ◽

Type Iv ◽

Time Period ◽

Invasive Infections ◽

Toxic Shock Syndrome Toxin ◽

Mrsa Strains

Abstract Background Recently, the Japanese intrinsic community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clone (CA-MRSA/J), classified as sequence type (ST) 8 carrying staphylococcal cassette chromosome mec (SCCmec) type IVl (ST8-IVl), has been identified that causes invasive infections similar to those of USA300 clone. However, epidemiological information regarding epidemic CA-MRSA clones is limited in Japan. This study was performed to investigate the changing epidemiology of MRSA causing bacteremia in Japan. Methods We performed whole-genome sequencing of MRSA isolates causing bacteremia at Hiroshima University Hospital between January 2008 and December 2017. MRSA isolates were subjected to multilocus sequence typing, SCCmec typing and were analyzed for virulence factors. Clinical data of patients with MRSA bacteremia were analyzed. Results A total of 193 MRSA strains causing bacteremia were identified during the study period. Among these, most belonged to ST764-IIa (30%; 59 of 193) and ST5-IIa (26.9%; 52 of 193). The proportion of ST5-IIa MRSA decreased from 39.6% (42 of 106) in 2008–2012 to 11.5% (10 of 87) in 2013–2017, and that of ST764-IIa MRSA increased from 23.6% (25 of 106) to 39.1% (34 of 87) in the same time period. The proportion of CA-MRSA (MRSA carrying SCCmec type IV or V) increased from 28.3% (30 of 106) in 2008–2012 to 42.5% (37 of 87) in 2013–2017. In CA-MRSA strains, clonal complex (CC) 8-IV MRSA was predominant (76.1%; 51 of 67). Those belonging to CC8-IV MRSA isolates were ST380-IVc (18 of 51), ST8-IVl (CA-MRSA/J; 15 of 51), ST8-IVj (15 of 51), ST8-IVa (2 of 51), and ST4803-IVl (1 of 51). The rate of hospital-onset infections of ST380-IVc, ST8-IVl, and ST8-IVj were 83.3%, 46.7%, and 60%, respectively. In CA-MRSA/J strains, including their variants (e.g., ST4803-IVl), 14 of 16 strains (87.5%) carried genes for toxic shock syndrome toxin (tst-1), enterotoxin C (sec), and enterotoxin L (sel), while none of the ST380-IVc and ST8-IVj MRSA strains carried these genes. Conclusion During the study period of 10 years, predominant ST5-IIa MRSA causing hospital-onset infections was replaced by ST764-IIa MRSA. In CA-MRSA clone, ST380-IVc, ST8-IVl (CA-MRSA/J), and ST8-IVj were dominant and have already spread to the healthcare environment. Disclosures All authors: No reported disclosures.

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Determination of minimum inhibitory concentration (MIC) of cloxacillin for selected isolates of methicillin-resistant Staphylococcus aureus (MRSA) with their antibiogram

Bangladesh Journal of Veterinary Medicine ◽

10.3329/bjvm.v6i1.1350 ◽

1970 ◽

Vol 6 (1) ◽

pp. 121-126 ◽

Cited By ~ 14

Author(s):

MA Islam ◽

MM Alam ◽

ME Choudhury ◽

N Kobayashi ◽

MU Ahmed

Keyword(s):

Staphylococcus Aureus ◽

Minimum Inhibitory Concentration ◽

Inhibitory Concentration ◽

Agar Plate ◽

Susceptibility Test ◽

Diffusion Method ◽

Clinical Samples ◽

Methicillin Resistant ◽

Antibiotic Susceptibility Test ◽

Mrsa Strains

The minimum inhibitory concentration (MIC) represents the concentration of antimicrobial at which there is complete inhibition of growth of organism. In order to determine the MIC of cloxacillin, 10 MRSA were previously detected from 40 clinical isolates of Staphylococcus aureus by polymerase chain reaction (PCR). Agar plate dilution test was used to determine the MIC of cloxacillin. The clinical samples were collected from Mymensingh Medical College Hospital, Mymensingh. The study was done in the Department of Medicine, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh from July 2006 to June 2007. The MIC of the cloxacillin for 5 MRSA strains were â¥32 (mg/ml), for 1 MRSA strain was â¥ 128(mg/ml) and for another 4 MRSA strains were above â¥128 (mg/ml). Antimicrobial susceptibility test of the isolated organisms were done by disc diffusion method. On antibiotic susceptibility test, MRSA strains showed 100% resistant against penicillin, oxacillin, cloxacillin and amoxycillin. Cent per cent susceptibility of MRSA was found against vancomycin, ciprofloxacin, erythromycin, fusidic acid and rifampicin. Key words: Minimum inhibitory concentration (MIC), antibiotic resistance, cloxacillin, methicillin-resistant Staphylococcus aureus (MRSA) DOI = 10.3329/bjvm.v6i1.1350 Bangl. J. Vet. Med. (2008). 6 (1): 121-126

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The Characterization of mecA Gene and SCCmec Typing in Clinical Samples of MRSA

Science Letters ◽

10.24191/sl.v13i2.7866 ◽

2019 ◽

Vol 13 (2) ◽

pp. 1

Author(s):

Ali Jawad ◽

Aziyah Abdul Aziz

Keyword(s):

Methicillin Resistance ◽

Sccmec Type ◽

Meca Gene ◽

Teaching Hospitals ◽

Clinical Samples ◽

Type I ◽

Biochemical Tests ◽

Type Iii ◽

Sccmec Typing ◽

Type Iv

MRSA is a major pathogen worldwide and its infections are associated with increased morbidity and mortality, in comparison with other S. aureus infections. The study was designed to characterize the mecA gene and staphylococcal cassette chromosome (SCCmec) in methicillin resistance S. aureus (MRSA). A total of 20 presumptive S. aureus strains were collected from one of the teaching hospitals in Selangor. Using standard biochemical tests, all the isolates were verified as S. aureus. When tested against cefoxitin, 80% of the isolates were confirmed as MRSA. All the MRSA isolates were further subjected to polymerase chain reaction (PCR) to detect the presence of mecA gene. Nine out of the 16 MRSA isolates (56%) were mecA positive, whereas the remaining four were mecA negative. The 16 MRSA with positive mecA gene were further subjected to SCCmec typing of type I, II, III, IV and V. The most frequent SCCmec types were type III (56%) followed by type II (33%), and type IV (11%). None of the isolates were of SCCmec type I or V. Our study indicates that SCCmec type III is predominant among the isolates which is in agreement with other studies conducted on clinical strains of MRSA.

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