scholarly journals Improved methods in the identification and screening for antimicrobial resistance: chromogenic screening for Staphylococcus aureus and methicillin resistance

2008 ◽  
Vol 29 (3) ◽  
pp. 150
Author(s):  
John Merlino
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Methicillin Resistance ◽  
Chromogenic Substrates ◽  
Methicillin Resistant ◽  
Microbial Identification ◽  
Laboratory Screening ◽  
Labour Costs ◽  
Improved Methods

New enzyme specific synthetic chromogenic substrates offer an advance in the laboratory screening and detection of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA), with increased efficiency, reduced labour costs and decreased turn around times, especially when incorporated into existing laboratory workflows, to support current methods of microbial identification and the detection of resistance.

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

2005 ◽  
Vol 21 (3) ◽  
pp. 123-128 ◽  
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.

scholarly journals Prevalence, Enterotoxigenic Potential and Antimicrobial Resistance of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated from Algerian Ready to Eat Foods

Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 835
Author(s):  
Omar Amine Mekhloufi ◽  
Daniele Chieffi ◽  
Abdelhamid Hammoudi ◽  
Sid Ahmed Bensefia ◽  
Francesca Fanelli ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Methicillin Resistance ◽  
Intergenic Spacer ◽  
Multidrug Resistant ◽  
Genetic Determinants ◽  
Methicillin Resistant ◽  
Intergenic Spacer Region ◽  
Type Iv ◽  
Toxic Shock Syndrome Toxin

Staphylococcus aureus causes a foodborne intoxication due to the production of enterotoxins and shows antimicrobial resistance, as in the case of methicillin-resistant strains (MRSA). Herein, we analyzed 207 ready-to-eat foods collected in Algeria, reporting a S. aureus prevalence of 23.2% (48/207) and respective loads of coagulase positive staphylococci (CPS) ranging from 1.00 ± 0.5 to 5.11 ± 0.24 Log CFU/g. The 48 S. aureus isolates were widely characterized by staphylococcal enterotoxin gene (SEg)-typing and 16S-23S rDNA intergenic spacer region (ISR)-PCR, as well as by detecting tst and mecA genes, genetic determinants of toxic shock syndrome toxin-1 and methicillin resistance, respectively. We found that the S. aureus isolates belonged to seven different SEg-types harboring the following combinations of genes: (1) selW, selX; (2) egc (seG, seI, seM, seN, seO), selW, selX; (3) seA, seH, seK, seQ, selW, selX; (4) seB, selW, selX; (5) seD, selJ, seR, selW, selX; (6) seH, selW, selX, selY; and (7) seA, egc, selW, selX, while among these, 2.1% and 4.2% were tst- and mecA- (staphylococcal chromosomal cassette mec-type IV) positive, respectively. Selected strains belonging to the 12 detected ISR-types were resistant towards antimicrobials including benzylpenicillin, ofloxacin, erythromycin, lincomycin, tetracyclin, kanamycin, oxacillin, and cefoxitin; 8.3% (1/12) were confirmed as MRSA and 16.7% (2/12) were multidrug resistant. The present study shows the heterogeneity of the S. aureus population in Algerian ready-to-eat foods as for their toxigenic potential and antimicrobial resistance, shedding the light on the quality and safety related to the consume of ready-to-eat foods in Algeria.

scholarly journals Prevalence of methicillin-resistant Staphylococcus aureus and pattern of antimicrobial resistance in mastitis milk of cattle in Chitwan, Nepal

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Asmita Shrestha ◽  
Rebanta Kumar Bhattarai ◽  
Himal Luitel ◽  
Surendra Karki ◽  
Hom Bahadur Basnet
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Subclinical Mastitis ◽  
World Health ◽  
Dairy Herds ◽  
Microbiological Analysis ◽  
Biochemical Tests ◽  
Methicillin Resistant ◽  
Milk Samples

Abstract Background The threat of methicillin-resistant Staphylococcus aureus (MRSA) exists globally and has been listed as a priority pathogen by the World Health Organization. One of the sources of MRSA emergence is livestock and its products, often raised in poor husbandry conditions. There are limited studies in Nepal to understand the prevalence of MRSA in dairy animals and its antimicrobial resistance (AMR) profile. A cross-sectional study was conducted in Chitwan, one of the major milk-producing districts of Nepal, from February 2018 to September 2019 to estimate the prevalence of MRSA in milk samples and its AMR profile. The collected milk samples (n = 460) were screened using the California Mastitis Test (CMT) and positive samples were subjected to microbiological analysis to isolate and identify S. aureus. Polymerase Chain Reaction (PCR) was used to identify the presence of the mecA gene and screen for MRSA. Results In total, 41.5% (191/460) of milk samples were positive in the CMT test. Out of 191 CMT positive milk samples, the biochemical tests showed that the prevalence of S. aureus was 15.2% (29/191). Among the 29 S. aureus isolates, 6.9% (2/29) were identified as MRSA based on the detection of a mecA gene. This indicates that that 1.05% (2/191) of mastitis milk samples had MRSA. The antibiotic sensitivity test showed that 75.9% (22/29) and 48.3% (14/29) S. aureus isolates were found to be sensitive to Cefazolin and Tetracycline respectively (48.3%), whereas 100% of the isolates were resistant to Ampicillin. In total 96.6% (28/29) of S. aureus isolates were multidrug-resistant (MDR). Conclusions This study revealed a high prevalence of S. aureus-mediated subclinical mastitis in dairy herds in Chitwan, Nepal, with a small proportion of it being MRSA carrying a mecA gene. This S. aureus, CoNS, and MRSA contaminated milk poses a public health risk due to the presence of a phenotype that is resistant to very commonly used antibiotics. It is suggested that dairy herds be screened for subclinical mastitis and treatments for the animals be based on antibiotic susceptibility tests to reduce the prevalence of AMR. Furthermore, future studies should focus on the Staphylococcus spp. to explore the antibiotic resistance genes in addition to the mecA gene to ensure public health.

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 Antimicrobial Resistance and Molecular Characteristics of Methicillin-resistant Staphylococcus aureus Isolates from Children Patients in Iran

2019 ◽  
Vol Volume 12 ◽  
pp. 3849-3857
Author(s):  
Roghayeh Samadi ◽  
Zhohreh Ghalavand ◽  
Reza Mirnejad ◽  
Bahram Nikmanesh ◽  
Gita Eslami
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Molecular Characteristics ◽  
Methicillin Resistant

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.

Investigation of the antibiotic resistance of staphylococcus species isolated from foods

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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