scholarly journals Origins and Evolution of Methicillin-Resistant Staphylococcus aureus Clonal Lineages

2006 ◽  
Vol 50 (10) ◽  
pp. 3237-3244 ◽  
Author(s):  
A. R. Gomes ◽  
H. Westh ◽  
H. de Lencastre
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Evolutionary Trajectory ◽  
Phage Group ◽  
Genetic Traits ◽  
Methicillin Resistant ◽  
Group Iii ◽  
Resistance To Penicillin ◽  
The 1960S

ABSTRACT Most methicillin-resistant Staphylococcus aureus (MRSA) isolates identified among blood isolates collected in Denmark between 1957 and 1970 belonged to either phage group III or the closely related 83A complex and had a PSTM antibiotype (resistance to penicillin [P], streptomycin [S], tetracycline [T], and methicillin [M]). Recently, some of these isolates were shown to have the same genetic backgrounds as contemporary epidemic MRSA isolates, and Danish methicillin-susceptible S. aureus (MSSA) isolates from the 1960s with a PST antibiotype were proposed to have been the recipients of the mecA gene in those lineages. In this study, we investigated the genetic backgrounds of isolates from the 83A complex that were fully susceptible or resistant to penicillin only in order to try to trace the evolutionary trajectory of contemporary MRSA lineages. We also studied MSSA and MRSA isolates from other phage groups in order to investigate if they had the potential to develop into contemporary MRSA clones. Most susceptible or penicillin-resistant isolates from phage group III or the 83A complex belonged to sequence type 8 (ST8) or ST5, while four isolates were ST254. STs 30, 45 and 25 were represented by MSSA isolates from other phage groups, which also included several singletons. Representatives of most of the current major epidemic MRSA lineages were identified among fully susceptible isolates collected in the 1960s, suggesting that these were MSSA lineages which carried genetic traits important for superior epidemicity before the acquisition of methicillin resistance.

scholarly journals Staphylococcus aureus prevalence among hospitalized patients

Medicina ◽  
2008 ◽  
Vol 44 (8) ◽  
pp. 593
Author(s):  
Žaneta Pavilonytė ◽  
Renata Kaukėnienė ◽  
Aleksandras Antuševas ◽  
Alvydas Pavilonis
Keyword(s):  
Staphylococcus Aureus ◽  
Prevalence Rate ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Phage Type ◽  
Hospitalized Patients ◽  
Diffusion Method ◽  
Phage Group ◽  
Methicillin Resistant ◽  
Group Iii ◽  
Group Ii

Objective. To determine the prevalence of Staphylococcus aureus strains among hospitalized patients at the beginning of their hospitalization and during their treatment and the resistance of strains to antibiotics, and to evaluate epidemiologic characteristics of these strains. Patients and methods. Sixty-one patients treated at the Department of Cardiac, Thoracic and Vascular Surgery were examined. Identification of Staphylococcus aureus strains was performed using plasmacoagulase and DNase tests. The resistance of Staphylococcus aureus to antibiotics, b-lactamase production, phagotypes, and phagogroups were determined. The isolated Staphylococcus aureus strains were tested for resistance to methicillin by performing disc diffusion method using commercial discs (Oxoid) (methicillin 5 mg per disk and oxacillin 1 mg per disk). Results. A total of 297 Staphylococcus aureus strains were isolated. On the first day of hospitalization, the prevalence rate of Staphylococcus aureus strains among patients was 67.3%, and it statistically significantly increased to 91.8% on days 7–10 of hospitalization (P<0.05). During hospitalization, patients were colonized with Staphylococcus aureus strains resistant to cephalothin (17.6% of patients, P<0.05), cefazolin (14.6%, P<0.05), tetracycline (15.0%, P<0.05), gentamicin (37.7%, P<0.001), doxycycline (30.7%, P<0.001), and tobramycin (10.6%, P>0.05). Three patients (4.9%) were colonized with methicillin-resistant Staphylococcus aureus strains, belonging to phage group II phage type 3A and phage group III phage types 83A and 77; 22.6– 25.5% of Staphylococcus aureus strains were nontypable. During hospitalization, the prevalence rate of phage group II Staphylococcus aureus strains decreased from 39.6% to 5.7% (P<0.05) and the prevalence rate of phage group III Staphylococcus aureus strains increased to 29.5% (P<0.001). Conclusions. Although our understanding of Staphylococcus aureus is increasing, well-designed communitybased studies with adequate risk factor analysis are required to elucidate further the epidemiology of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. Surveillance of methicillin-resistant Staphylococcus aureus provides relevant information on the extent of the methicillin-resistant Staphylococcus aureus epidemic, identifies priorities for infection control and the need for adjustments in antimicrobial drug policy, and guides intervention programs.

scholarly journals Staphylococcus aureus prevalence among preschool- and school-aged pupils

Medicina ◽  
2007 ◽  
Vol 43 (11) ◽  
pp. 887 ◽  
Author(s):  
Žaneta Pavilonytė ◽  
Justina Kačerauskienė ◽  
Brigita Budrytė ◽  
Tadas Keizeris ◽  
Jonas Junevičius ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Disc Diffusion Method ◽  
Phage Group ◽  
Methicillin Resistant ◽  
Group Iii ◽  
12Th Grade ◽  
Group Ii

Object. To determine the prevalence and incidence of Staphylococcus aureus strains among preschool- and school-aged pupils and susceptibility of these strains to antimicrobial materials.Material and methods. A study of 243 preschool- and 300 school-aged pupils was conducted during 2003– 2004. Identification of Staphylococcus aureus was made with plasmacoagulase and DNase tests. The resistance of Staphylococcus aureus to antibiotics, b-lactamase activity, phagotypes, and phage groups were determined. The isolated Staphylococcus aureus strains were tested for resistance to methicillin by performing disc diffusion method using commercial discs (Oxoid) (methicillin 5 mg per disk and oxacillin 1 mg per disk). Results. A total of 292 (53.8%) Staphylococcus aureus strains were isolated and identified (113 (46.5%) from preschool- and 179 (59.7%) from school-aged pupils). The prevalence of Staphylococcus aureus strains among preschool-aged pupils varied from 46.5% to 47%. It increased to 59.0% (P>0.05) among schoolchildren aged from 11 to 15 years and to 73.0% (P<0.001) among schoolchildren aged from 16 to 19 years. Six methicillinresistant Staphylococcus aureus strains were isolated: two (1.8%) of them were from preschool-aged and four (2.2%) from school-aged pupils. The prevalence of Staphylococcus aureus strains with b-lactamase activity increased from 70.7 to 76.6% in preschool-aged pupils, and it varied from 72.0 to 79.0% in school-aged pupils (P>0.05). Staphylococcus aureus strains of phage group II (32.2–43.4%) were prevailing; nontypable Staphylococcus aureus strains made up 19.2–33.6%. Conclusions. The prevalence of Staphylococcus aureus among preschool-aged children is 41.7 to 48.8%, and it increases among 9th–12th-grade pupils (73.0%, P<0.001). Some Staphylococcus aureus strains (2.1%) were resistant to methicillin. Staphylococcus aureus strains of phage group II (39.0%, P<0.05) are most prevalent among preschool- and school-aged pupils. Pupils were colonized with methicillin-resistant Staphylococcus aureus strains belonging to phage group III phagotype 83A and 77.

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

Pathogens ◽  
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.

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

2009 ◽  
Vol 54 (2) ◽  
pp. 610-613 ◽  
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.

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

2012 ◽  
Vol 45 (2) ◽  
pp. 189-193 ◽  
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.

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

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.                  

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 Effect of exogenous glycine on peptidoglycan composition and resistance in a methicillin-resistant Staphylococcus aureus strain.

1996 ◽  
Vol 40 (6) ◽  
pp. 1498-1503 ◽  
Author(s):  
B L de Jonge ◽  
Y S Chang ◽  
N Xu ◽  
D Gage
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Aureus Strain ◽  
Methicillin Resistant ◽  
Resistance Phenotype ◽  
Concomitant Decrease

A highly homogeneously methicillin-resistant Staphylococcus aureus strain was grown in the presence of various concentrations of exogenous glycine. Increasing concentrations of glycine in the medium resulted in a decrease in methicillin resistance and the appearance of a heterogeneous resistance phenotype. Parallel to the gradual changes in resistance was an alteration in the muropeptide composition of peptidoglycan. Increasing concentrations of glycine in the medium resulted in peptidoglycan in which muropeptides with a D-alanyl-D-alanine terminus were replaced with D-alanyl-glycine-terminating muropeptides. The disappearance of D-alanyl-D-alanine-terminating muropeptides in peptidoglycan and the concomitant decrease in resistance indicate a central role for D-alanyl-D-alanine-terminating precursors in methicillin resistance.

scholarly journals Carriage Methicillin-Resistant Staphylococcus aureus in Poultry and Cattle in Northern Algeria

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Saliha Bounar-Kechih ◽  
Mossadak Taha Hamdi ◽  
Hebib Aggad ◽  
Nacima Meguenni ◽  
Zafer Cantekin
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Broiler Chickens ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Laying Hens ◽  
Methicillin Resistance ◽  
Public Health Problem ◽  
Cross Resistance ◽  
Isolation And Identification ◽  
Methicillin Resistant

Multiresistant and especially Methicillin-Resistant Staphylococcus aureus (MRSA) poses a serious public health problem that requires their immediate identification and antibiotic resistance characteristics. In order to determine antibiotic resistance S. aureus poultry and bovine origin, 8840 samples were collected from slaughterhouses in the northern region of Algeria between years 2009 and 2014. 8375 samples were from an avian origin (1875 from laying hens and 6500 from broiler chickens) and the rest was from bovine origin. Bacteriological isolation and identification were made by classical culture method and antibiotic resistance patterns were determined by disc diffusion test. The prevalence of S. aureus was 42% in laying hens, 12% in broilers, and 55% in bovine samples. The prevalence of MRSA was 57%, 50%, and 31% in laying hens, broiler chickens, and bovine, respectively. While MRSA strains isolated from poultry showed cross-resistance to aminoglycosides, fluoroquinolones, macrolides, sulphonamides, and cyclins, those isolated from bovine also revealed similar multiresistance except for sulphonamide. This high percentage of methicillin resistance and multidrug resistance in S. aureus poultry and bovine origin may have importance for human health and curing of human infections.

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