scholarly journals Characterization of Gentamicin-Susceptible Strains of Methicillin-Resistant Staphylococcus aureus Involved in Nosocomial Spread

1998 ◽  
Vol 36 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Nadine Lemaître ◽  
Wladimir Sougakoff ◽  
Afef Masmoudi ◽  
Marie-Hélène Fievet ◽  
Roland Bismuth ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dna Hybridization ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Pulsed Field Gel Electrophoresis ◽  
Cross Infection ◽  
Methicillin Resistant ◽  
Resistance Patterns ◽  
Mrsa Strains ◽  
Selection Of

We report an outbreak of epidemic Staphylococcus aureusstrains characterized by an unusual heterogeneous resistance to methicillin and resistance to tobramycin but susceptibility to gentamicin (gentamicin-susceptible methicillin-resistant S. aureus [GS-MRSA]), contrasting with gentamicin-resistant homogeneous MRSA (GR-MRSA) that have been endemic in our hospital since the 1970s. A total of 97 GS-MRSA strains, which were shown by DNA hybridization to carry the mecA and ant(4′)-Iagenes, were studied. The 40 GS-MRSA strains isolated at the beginning of the outbreak (January 1992 to June 1993) were typed by using resistance patterns, phage typing, serotyping, and pulsed-field gel electrophoresis and were compared with GR-MRSA and methicillin-susceptible S. aureus (MSSA) strains isolated during the same period. Two dominant clones, A::1 and B::3, and one minor clone, C::5, were identified among the 40 GS-MRSA strains, according to pulsotypes (A to C) and their resistance patterns (1, 3, and 5), which were distinguishable from those of GR-MRSA and MSSA strains. A selection of 57 GS-MRSA strains, isolated from 1994 to 1996, were clustered in the same three clones. However, their distribution had changed in comparison with that in the 1992 to 1993 period: clone A::1 remained dominant (47 versus 42.5%), whereas clone B::3 progressively declined (5 versus 35%) and clone C::5, the most susceptible to antibiotics, spread (44 versus 2.5%). Epidemiological investigations revealed that some clones had been introduced via patients transferred from other hospitals and that cross-infection occurred within and between wards. Major changes in the use of antibiotics, especially aminoglycosides, cyclines, and macrolides, likely played a role in the emergence and spread of GS-MRSA strains.

scholarly journals Methicillin-Resistant Staphylococcus aureus ST80 Clone: A Systematic Review

Toxins ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 119 ◽  
Author(s):  
Assia Mairi ◽  
Abdelaziz Touati ◽  
Jean-Philippe Lavigne
Keyword(s):  
Systematic Review ◽  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Sampling Period ◽  
Spa Typing ◽  
Methicillin Resistant ◽  
Resistance Patterns ◽  
Mrsa Strains ◽  
Spa Type

This review assessed the molecular characterization of the methicillin-resistant Staphylococcus aureus (MRSA)-ST80 clone with an emphasis on its proportion of total MRSA strains isolated, PVL production, spa-typing, antibiotic resistance, and virulence. A systematic review of the literature was conducted on MRSA-ST80 clone published between 1 January 2000 and 31 August 2019. Citations were chosen for a review of the full text if we found evidence that MRSA-ST80 clone was reported in the study. For each isolate, the country of isolation, the sampling period, the source of isolation (the type of infection, nasal swabs, or extra-human), the total number of MRSA strains isolated, number of MRSA-ST80 strains, antibiotic resistance patterns, PVL production, virulence genes, and spa type were recorded. The data from 103 articles were abstracted into an Excel database. Analysis of the data showed that the overall proportion of MRSA-ST80 has been decreasing in many countries in recent years. The majority of MRSA-ST80 were PVL positive with spa-type t044. Only six reports of MRSA-ST80 in extra-human niches were found. This review summarizes the rise of MRSA-ST80 and the evidence that suggests that it could be in decline in many countries.

scholarly journals Molecular analysis of methicillin-resistant Staphylococcus aureus isolates from four teaching hospitals in Iran: The emergence of Novel MRSA ST- SCCmec clones

2020 ◽  
Author(s):  
Farzaneh Firoozeh ◽  
Mitra Omidi ◽  
Mahmood Saffari ◽  
Hossein Sedaghat ◽  
Mohammad Zibaei
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Teaching Hospitals ◽  
Diffusion Method ◽  
Methicillin Resistant ◽  
Resistance Patterns ◽  
Mrsa Strains ◽  
Type V ◽  
Resistance Rates ◽  
Antibiotic Resistance Patterns

Abstract Background: The global spread of methicillin-resistant Staphylococcus aureus (MRSA) infections necessitates the use of validated methods for the identification and typing of this bacterium. This study aimed to determine the distribution of main molecular types of MRSA strain circulating among hospitalized patients in teaching hospitals in Isfahan and Kashan. Methods: A total of 146 Staphylococcus aureus strains were isolated from patients in four teaching hospitals in Isfahan and Kashan during June 2017 to September 2018. The antibiotic resistance patterns of Staphylococcus aureus strains were performed by disc diffusion method. The MRSA strains were identified phenotypically and confirmed by PCR assay. The prevalence of microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) genes among MRSA strains was evaluated by multiplex PCR. The genotypes of MRSA strains were determined by multi-locus sequence type and SCC mec typing. Results: Of 146 Staphylococcus aureus isolates 24 (16.4%) isolates identified as MRSA strains. According to antibiotic susceptibility testing the highest resistance rates were seen to erythromycin, cefoxitin and clindamycin. All of Staphylococcus aureus isolates were sensitive to vancomycin whereas 3 (2.1%) isolates were resistant to linezolid. Three different SCC mec types were obtained among MRSA strains including 16 (66.7%) SCC mec type V, 3 (12.5%) SCC mec type III and 5 (20.8%) SCC mec type II. Of 24 MRSA isolates 20 (83.3%) carried MSCRAMMs genes including eno (70.8%), fib (54.1%) , cna (25.0%), fnbB (16.6%) , ebps 5 (20.8%), and fnbA , bbp and clfA genes were not detected. MLST analysis revealed 11 sequence types among MRSA isolates as follows: ST239, ST239, ST291, ST22, ST861, ST 889, ST8, ST59, ST343, ST772, ST6 and ST1465. Also seven MLST-based clonal complexes (CCs) were identified among MRSA strains including: CC8, CC7, CC398, CC59, CC22, CC1 and CC5. Conclusions: A relatively high diversity was found in MRSA genotypes in Kashan and Isfahan hospitals, and seven clonal complexes were identified. Pandemic MRSA clones including CC8 and CC22 were the most prevalent clones and the novel ST types including ST1465, ST861, ST 889 and ST772 are reported for the first time in Iran in the present study. In addition the high prevalence of MSCRAMMs genes in MRSA isolates demonstrates the high potential of these strains for pathogenicity.

scholarly journals Molecular Characterization of Community-Associated Methicillin-Resistant Staphylococcus aureus in Iranian Burn Patients

2019 ◽  
Vol 14 (4) ◽  
pp. 284-289 ◽  
Author(s):  
Samira Tajik ◽  
Shahin Najar Peerayeh ◽  
Bita Bakhshi ◽  
Reza Golmohammadi
Keyword(s):  
Staphylococcus Aureus ◽  
Molecular Characterization ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Significant Proportion ◽  
Burn Patients ◽  
Burn Wound ◽  
Methicillin Resistant ◽  
Pfge Typing ◽  
Mrsa Strains

Background & Objective: Methicillin-resistant Staphylococcus aureus (MRSA) is reported as one of the important bacterial causes of burn wound infections. This study was carried out to investigate molecular characterization of community-associated MRSA (CA-MRSA) isolated from Iranian burn patients. Methods: A total of 31 isolates of S. aureus were collected fromthe Motahari Burns Hospital (Tehran, Iran) in 2016. All isolates were collected from outpatients and inpatients within 48 hours of admission. The mecA, pvl, tsst-1, hla-α, and psmα genes detecting, SCCmec, agr and PFGE typing were done. Results: A total of 13 (41.9%) isolates were cefoxitin-resistant and mecA-positive, which were considered as MRSA. The SCCmec typing MRSA strains revealed type II in 1 (7.7%), type III in 9 (69.2%), and other types in 3 isolates (23.7%) cases. The agrtyping of all 31 isolates showed that 14 (45.2%), 1 (3.2%), 6 (19.4%), and 10 (32.3%) strains belonged to agr groups 1, 3, 4, and unknown type, respectively. The pvl, tsst-1, hla-α, and psmα genes were positive in 3 (9.7%), 4 (12.9%), 21 (67.7%), and 31 (100%) isolates, respectively. Considering the cut-off values of ≥50%, 3 groups of related isolates (cluster A1, B1, and C1) in PFGE study were observed. Conclusion: The MRSA strains of this study were initially isolated as Community-associated S. aureus (CA-MRSA); however molecular characterization showed that a significant proportion of them had hospital-associated MRSA (HA-MRSA) features. Therefore, it is likely that the HA-MRSA strains are spread among the community.

scholarly journals Sampling, prevalence and characterization of methicillin-resistant Staphylococcus aureus on two Belgian pig farms

2011 ◽  
Vol 1 (1) ◽  
pp. 1 ◽  
Author(s):  
Isabelle Dewaele ◽  
Winy Messens ◽  
Ingrid De Man ◽  
Pierre Delputte ◽  
Lieve Herman ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistant ◽  
Air Inlet ◽  
Significant Difference ◽  
Pig Farms ◽  
Slaughter Age ◽  
Mrsa Strains ◽  
On Farm

This study investigated the spread of MRSA (methicillin-resistant <em>Staphylococcus aureus</em>) on two Belgian pig farms. Pigs of different ages (from farrowing to slaughter age and sows) as well as the barn environment were screened extensively on two occasions three months apart. A subset of MRSA isolates was tested for antimicrobial susceptibility to 16 antibiotics and was further characterized by pulsed-field gel electrophoresis. Ninety-five percent and 77% of the tested pigs on farm A and farm B, respectively, were colonized with MRSA. MRSA positive animals were detected in all age categories sampled on each sampling day. Piglets were already colonized in the farrowing unit with the same or other MRSA strains than their mother. The prevalence of MRSA colonized pigs increased significantly after weaning and decreased during the fattening period. Pigs carried MRSA mainly in the nares, followed by the perineum and skin and to a lesser degree the rectum. A pig could be contaminated or colonized with different MRSA strains at the same time. The barn environment was also found to be contaminated with different MRSA strains, including the air inlet and outlet. All isolates tested on both farms were resistant to both tetracycline and trimethoprim, while they were susceptible to rifampicin, mupirocin and linezolid. There was a significant difference in resistance prevalence between the two farms for the antibiotics gentamicin, kanamycin, tobramycin, tylosin, lincomycin and quinupristin/dalfopristin. Furthermore, several antibiotic resistance profiles were observed within one farm. This study clearly indicates that several MRSA strains circulate on one farm, from the nursery unit to the fattening unit. This is important to consider when attempts are made to remediate these farms.

scholarly journals Outbreak of Methicillin-Resistant Staphylococcus aureus with Reduced Susceptibility to Glycopeptides in a Parisian Hospital

2000 ◽  
Vol 38 (8) ◽  
pp. 2985-2988 ◽  
Author(s):  
François Guerin ◽  
Annie Buu-Hoï ◽  
Jean-Luc Mainardi ◽  
Guillaume Kac ◽  
Nathalie Colardelle ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Brain Heart Infusion ◽  
Multidrug Resistant ◽  
Pulsed Field Gel Electrophoresis ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Mrsa Strains ◽  
Standard Disk

Epidemiological relationships were investigated between 40 methicillin-resistant Staphylococcus aureus (MRSA) strains with decreased glycopeptide susceptibility isolated from November 1998 to March 1999 from 39 patients (17 infected and 22 colonized patients) in nine wards of the Broussais Hospital, Paris, France. Reduced glycopeptide susceptibility was readily detected on brain heart infusion (BHI) agar containing 6 μg of teicoplanin per ml and on gradient plates, but not by the standard disk diffusion method. The MICs of vancomycin and teicoplanin, determined on BHI agar, were 4 and 8 to 32 μg/ml, respectively (standard antibiotic dilution), and 4 to 8 and 8 to 32 μg/ml, respectively (E-test). All strains were resistant to macrolides, aminoglycosides, tetracycline, rifampin, sulfonamides, and pefloxacin, showed reduced susceptibility to fusidic acid and fosfomycin, and were susceptible to trimethoprim and chloramphenicol. Pulsed-field gel electrophoresis and lysotyping revealed that a multidrug-resistant MRSA clone with decreased susceptibility to glycopeptides has been discretely endemic since at least 1996 in our institution, where it was responsible for an outbreak in November and December 1998.

scholarly journals Transmission and Persistence of Livestock-Associated Methicillin-Resistant Staphylococcus aureus among Veterinarians and Their Household Members

2014 ◽  
Vol 81 (1) ◽  
pp. 124-129 ◽  
Author(s):  
T. Bosch ◽  
E. Verkade ◽  
M. van Luit ◽  
F. Landman ◽  
J. Kluytmans ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Genotypic Variation ◽  
Methicillin Resistant ◽  
Content Type ◽  
Genome Maps ◽  
Household Members ◽  
Mrsa Strains ◽  
Prospective Longitudinal

ABSTRACTAfter the first isolation of livestock-associated methicillin-resistantStaphylococcus aureus(LA-MRSA) in 2003, this MRSA variant quickly became the predominant MRSA obtained from humans as part of the Dutch national MRSA surveillance. Previous studies have suggested that human-to-human transmission of LA-MRSA, compared to that of other MRSA lineages, rarely occurs. However, these reports describe the transmission of LA-MRSA based on epidemiology and limited molecular characterization of isolates, making it difficult to assess whether transmission actually occurred. In this study, we used whole-genome maps (WGMs) to identify possible transmission of LA-MRSA between humans. For this, we used LA-MRSA isolates originating from a 2-year prospective longitudinal cohort study in which livestock veterinarians and their household members were repeatedly sampled for the presence ofS. aureus. A considerable degree of genotypic variation among LA-MRSA strains was observed. However, there was very limited variability between the maps of the isolates originating from the same veterinarian, indicating that each of the veterinarians persistently carried or had reacquired the same LA-MRSA strain. Comparison of WGMs revealed that LA-MRSA transmission had likely occurred within virtually every veterinarian household. Yet only a single LA-MRSA strain per household appeared to be involved in transmission. The results corroborate our previous finding that LA-MRSA is genetically diverse. Furthermore, this study shows that transmission of LA-MRSA between humans occurs and that carriage of LA-MRSA can be persistent, thus posing a potential risk for spread of this highly resistant pathogen in the community.

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