scholarly journals Phenotypic and Genotypic Characterization of Nosocomial Staphylococcus aureus Isolates from Trauma Patients

1998 ◽  
Vol 36 (2) ◽  
pp. 414-420 ◽  
Author(s):  
T. Na’was ◽  
A. Hawwari ◽  
E. Hendrix ◽  
J. Hebden ◽  
R. Edelman ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Trauma Patients ◽  
Resistant Genotype ◽  
Methicillin Resistant ◽  
University Of Maryland ◽  
Single Clone ◽  
Resistant Strains ◽  
Mrsa Strains ◽  
The University

Staphylococcus aureus is a major cause of nosocomial infections. During the period from March 1992 to March 1994, the patients admitted to the intensive care unit of the University of Maryland Shock Trauma Center were monitored for the development ofS. aureus infections. Among the 776 patients eligible for the study, 60 (7.7%) patients developed 65 incidents of nosocomialS. aureus infections. Of the clinical isolates, 43.1% possessed a polysaccharide type 5 capsule, 44.6% possessed a type 8 capsule, and the remaining 12.3% had capsules that were not typed by the type 5 or type 8 antibodies. Six antibiogram types were noted among the infection-related isolates, with the majority of the types being resistant only to penicillin and ampicillin. It was noted that the majority of cases of pneumonia were caused by relatively susceptible strains, while resistant strains were isolated from patients with bacteremia and other infections. Only 16 (6.3%) of the isolates were found to be methicillin-resistant S. aureus (MRSA). DNA fingerprinting by pulsed-field gel electrophoresis showed 36 different patterns, with characteristic patterns being found for MRSA strains and the strains with different capsular types. Clonal relationships were established, and the origins of the infection-related isolates in each patient were determined. We conclude that (i) nosocomial infection-related isolates from the shock trauma patients did not belong to a single clone, although the predominance of a methicillin-resistant genotype was noted, (ii) most infection-relatedS. aureus isolates were relatively susceptible to antibiotics, but a MRSA strain was endemic, and (iii) for practical purposes, the combination of the results of capsular and antibiogram typing can be used as a useful epidemiological marker.

Genetic characterization of two methicillin-resistant Staphylococcus aureus spa type t127 strains isolated from workers in the dairy production chain in Greece

2021 ◽  
Author(s):  
Theodoros Karampatakis ◽  
Panagiotis Papadopoulos ◽  
Katerina Tsergouli ◽  
Apostolos S. Angelidis ◽  
Daniel Sergelidis ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Genetic Characterization ◽  
Food Handler ◽  
Dairy Production ◽  
Whole Genome ◽  
Genome Sequences ◽  
Production Chain ◽  
Methicillin Resistant ◽  
Mrsa Strains

AbstractMethicillin-resistant Staphylococcus aureus (MRSA) constitutes a constant threat for the public health. Aim of the present study was to analyse the whole genome sequences of two MRSA strains belonging to Staphylococcus protein A (spa) type t127 isolated from humans working in two distantly located dairy production farms in Greece.MRSA strains were isolated from the nasal cavity of a food handler in a milk industry in Epirus, northwestern Greece (E-MRSA), and a person working in a cattle farm in Thrace, northeastern Greece (T-MRSA). Whole genome sequences taken using next generation sequencing were analysed for resistance and virulence genes applying various bioinformatic tools.Both isolates were assigned to ST1-IVa-t127 type, and they were transferring genes conferring resistance to tetracycline, β-lactams, and aminoglycosides; T-MRSA was carrying additional genes leading to macrolide, lincosamide and streptogramin B (MLSB) resistance. Both isolates were carrying three plasmid replicon types, rep5, rep7 and rep16, while T-MRSA harboured also rep10 and rep15. E-MRSA carried scn and sak genes which were absent from T-MRSA.In conclusion, the genetic characterization of two unrelated ST1-IVa-t127 MRSA strains isolated from humans in close contact with livestock in Greece can be used as basis for further epidemiological and evolutionary studies.

scholarly journals Antibiotic Resistance and Virulence Gene Characteristics of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated from Healthy Edible Marine Fish

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Justine Fri ◽  
Henry A. Njom ◽  
Collins N. Ateba ◽  
Roland N. Ndip
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Marine Fish ◽  
Control Strategies ◽  
Virulence Gene ◽  
Multidrug Resistant ◽  
Methicillin Resistant ◽  
Vancomycin Mics ◽  
Resistant Strains ◽  
Mrsa Strains

Thirty-three (33) isolates of methicillin-resistant Staphylococcus aureus (MRSA) from healthy edible marine fish harvested from two aquaculture settings and the Kariega estuary, South Africa, were characterised in this study. The phenotypic antimicrobial susceptibility profiles to 13 antibiotics were determined, and their antibiotic resistance determinants were assessed. A multiplex PCR was used to determine the epidemiological groups based on the type of SCCmec carriage followed by the detection of staphylococcal enterotoxin-encoding genes sea-sed and the Panton Valentine leucocidin gene (pvl). A high antibiotic resistance percentage (67–81%) was observed for Erythromycin, Ampicillin, Rifampicin, and Clindamycin, while maximum susceptibility to Chloramphenicol (100%), Imipenem (100%), and Ciprofloxacin (94%) was recorded. Nineteen (58%) of the MRSA strains had Vancomycin MICs of ≤2 μg/mL, 4 (12%) with MICs ranging from 4–8 μg/mL, and 10 (30%) with values ≥16 μg/mL. Overall, 27 (82%) isolates were multidrug-resistant (MDR) with Erythromycin-Ampicillin-Rifampicin-Clindamycin (E-AMP-RIP-CD) found to be the dominant antibiotic-resistance phenotype observed in 4 isolates. Resistance genes such as tetM, tetA, ermB, blaZ, and femA were detected in two or more resistant strains. A total of 19 (58%) MRSA strains possessed SCCmec types I, II, or III elements, characteristic of healthcare-associated MRSA (HA-MRSA), while 10 (30%) isolates displayed SCCmec type IVc, characteristic of community-associated MRSA (CA-MRSA). Six (18%) of the multidrug-resistant strains of MRSA were enterotoxigenic, harbouring the see, sea, or sec genes. A prevalence of 18% (6/33) was also recorded for the luk-PVL gene. The findings of this study showed that marine fish contained MDR-MRSA strains that harbour SCCmec types, characteristic of either HA-MRSA or CA-MRSA, but with a low prevalence of enterotoxin and pvl genes. Thus, there is a need for continuous monitoring and implementation of better control strategies within the food chain to minimise contamination of fish with MDR-MRSA and the ultimate spread of the bug.

scholarly journals Missense Mutations in PBP2A Affecting Ceftaroline Susceptibility Detected in Epidemic Hospital-Acquired Methicillin-Resistant Staphylococcus aureus Clonotypes ST228 and ST247 in Western Switzerland Archived since 1998

2015 ◽  
Vol 59 (4) ◽  
pp. 1922-1930 ◽  
Author(s):  
William L. Kelley ◽  
Ambre Jousselin ◽  
Christine Barras ◽  
Emmanuelle Lelong ◽  
Adriana Renzoni
Keyword(s):  
Staphylococcus Aureus ◽  
University Hospital ◽  
Surveillance Program ◽  
Missense Mutations ◽  
Unknown Parameters ◽  
Methicillin Resistant ◽  
Content Type ◽  
Resistant Strains ◽  
Mrsa Strains

ABSTRACTThe development and maintenance of an arsenal of antibiotics is a major health care challenge. Ceftaroline is a new cephalosporin with activity against methicillin-resistantStaphylococcus aureus(MRSA); however, no reports concerning MRSA ceftaroline susceptibility have been reported in Switzerland. We tested thein vitroactivity of ceftaroline against an archived set of 60 MRSA strains from the University Hospital of Geneva collected from 1994 to 2003. Our results surprisingly revealed ceftaroline-resistant strains (MIC, >1 μg/ml in 40/60 strains; EUCAST breakpoints, susceptible [S], ≤1 μg/ml; resistant [R], >1 μg/ml) were present from 1998 to 2003. The detected resistant strains predominantly belonged to sequence type 228 (ST228) (South German clonotype) but also to ST247 (Iberian clonotype). A sequence analysis of these strains revealed missense mutations in the penicillin-binding protein 2A (PBP2A) allosteric domain (N146K or E239K and N146K-E150K-G246E). The majority of our ST228 PBP2A mutations (N146K or E150K) were distinct from ST228 PBP2A allosteric domain mutations (primarily E239K) recently described for MRSA strains collected in Thailand and Spain during the 2010 Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) global surveillance program. We also found that similar allosteric domain PBP2A mutations (N146K) correlated with ceftaroline resistance in an independent external ST228 MRSA set obtained from the nearby University Hospital of Lausanne, Lausanne, Switzerland, collected from 2003 to 2008. Thus, ceftaroline resistance was observed in our archived strains (including two examples of an MIC of 4 µg/ml for the Iberian ST247 clonotype with the triple mutation N146K/E150K/G246E), at least as far back as 1998, considerably predating the commercial introduction of ceftaroline. Our results reinforce the notion that unknown parameters can potentially exert selective pressure on PBP2A that can subsequently modulate ceftaroline resistance.

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 Phenotypic and Molecular Typing of Nosocomial Methicillin-Resistant Staphylococcus aureus Strains Susceptible to Gentamicin Isolated in France from 1995 to 1997

2000 ◽  
Vol 38 (1) ◽  
pp. 185-190
Author(s):  
Jacques-Olivier Galdbart ◽  
Anne Morvan ◽  
Nevine El Solh
Keyword(s):  
Staphylococcus Aureus ◽  
Molecular Typing ◽  
Insertion Sequence ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Phage Typing ◽  
Methicillin Resistant ◽  
Before And After ◽  
Resistant Strains ◽  
Mrsa Strains

ABSTRACT Methicillin-resistant strains susceptible to gentamicin (Gm s MRSA) have emerged since 1993 in several French hospitals. To study whether particular clones have spread in various French cities and whether some clones are related to gentamicin-resistant (Gm r ) MRSA strains, various methods (antibiotyping, phage typing, determination of Sma I macrorestriction patterns before and after hybridization with IS 256 transposase and aacA-aphD probes) were used to compare 62 Gm s MRSA strains isolated from 1995 to 1997 in nine cities and 15 Gm r MRSA strains. Eighteen major Sma I genotypes were identified, of which 11 included only Gm s MRSA strains and 5 included only Gm r MRSA strains. Each of the Gm r MRSA strains contained 6 to 13 Sma I fragments hybridizing with the insertion sequence IS 256 , of which a single band also hybridized with the aacA-aphD gene. No such hybridizing sequences were detected in 60 of the 62 Gm s MRSA strains. Thus, the divergence between Gm r and Gm s MRSA strains is revealed, not only by their distributions in distinct Sma I genotypes but also by the differences in hybridization patterns. Two of the 62 Gm s MRSA strains had the uncommon feature of carrying several Sma I bands hybridizing with IS 256 , suggesting that they are possibly related to the Gm r MRSA strains grouped in the same Sma I genotype. Five of the 11 Sma I genotypes including only Gm s MRSA strains contained strains from diverse cities, isolated during different years and with different antibiograms, suggesting that some clones have spread beyond their cities of origin and persisted.

scholarly journals Ability of biofilm production and molecular analysis of spa and ica genes among clinical isolates of methicillin-resistant Staphylococcus aureus

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Mitra Omidi ◽  
Farzaneh Firoozeh ◽  
Mahmood Saffari ◽  
Hossein Sedaghat ◽  
Mohammad Zibaei ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cross Sectional Study ◽  
Clinical Isolates ◽  
Cross Sectional ◽  
Disk Diffusion Test ◽  
Methicillin Resistant ◽  
Isfahan Province ◽  
Biofilm Production ◽  
Mrsa Strains

Abstract Objective This study aimed to evaluate the phenotypic and genotypic characterization of biofilm formation and spa and ica genes among clinical isolates of methicillin-resistant Staphylococcus aureus. Result This cross-sectional study was performed on 146 Staphylococcus aureus isolates from hospitalized patients in Isfahan Province Hospitals. MRSA isolates were confirmed using disk diffusion test with oxacillin disk and amplification of mecA gene by PCR assays. Ability of biofilm production was evaluated targeting the icaA and icaD genes. Of 146 Staphylococcus aureus isolates, 24 (16.4%) carried mecA genes and identified as MRSA strains. Strong ability of biofilm production was seen among 76.02% (111/146) S. aureus isolates and 87.5% (21/24) MRSA strains, respectively. Also, 75.0% (18/24) MRSA isolates carried icaA and icaD was not detected in these strains. Analysis of spa gene showed 70.83% (17/24) MRSA strains were spa positive. From which 14 and 3 strains identified with one band (150, 270, 300, 360, 400 bp) and two bands (150–300 bp), respectively. According to data obtained, the prevalence of MRSA isolates from Isfahan Province Hospitals is relatively high and a remarkable percentage of them show strong power in biofilm production. Also analysis of spa gene showed a fairly large diversity among MRSA strains.

Diversity of SCCmec Elements in Methicillin-Resistant Staphylococcus Aureus (MRSA) Recovered from a Healthy Student Population in Kenya

2020 ◽  
Author(s):  
Osborn Khasabuli ◽  
Caroline Ngugi ◽  
John Kiiru
Keyword(s):  
Residence Halls ◽  
Cross Sectional Study ◽  
Student Population ◽  
Cross Sectional ◽  
Methicillin Resistant ◽  
Gene Cassettes ◽  
Resistant Strains ◽  
Mrsa Strains ◽  
Resistance Island ◽  
The University

Abstract Background: Methicillin-resistant S. aureus continues to be a concern for public health systems, particularly due to infections emerging in non-hospital settings. Resistance to methicillin is presently classified as a serious phenomenon because the majority of methicillin-resistant strains are also multi-drug resistant. The genetic determinant of resistance to methicillin and other β-lactam antibiotics is the mec-A gene, which lies in the SCCmec resistance island. In Kenya, studies done previously have shown the existence of SCCmec types in clinical isolates, but similar information on isolates recovered from healthy populations is scanty.Methods: A cross-sectional study was conducted on healthy university students residing within the university residence halls to determine the carriage of MRSA. MRSA was detected using Cefoxitin (30µg), and mec-A gene and Sccmec elements were detected using conventional PCR methods. A total of 237 students were recruited, and 657 swabs were collected using standards methods for recovering S. aureus.Results: A total of 231 S. aureus isolates were recovered, out of which 26 (11.3%) were MRSA. Out of the 26 MRSA strains, 17 carried the mecA gene in their gene cassettes. SCCmecV was the most prevalent (61.5%), followed by SCCmecII (53.9%) among the MRSA strains. SCCmecIVa, SCCmecIVb, SCCmecIVc and SCCmecIVd were absent in all the isolates. SCCmecV was found to be highly prevalent (64.7%) followed by SCCmecII, 8 (47.1%) among the mecA-positive MRSA strains. On the other hand, small proportions of mecA-negative isolates harbored SCCmecI (0.9%), SCCmecII (3.3%), SCCmec III (0.5%) and SCCmecV (2.3%).Conclusion: This study revealed that the strains recovered from the student population were highly diverse in terms of the SCCmec elements they carried in their gene cassettes.

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