scholarly journals Characterization and Proposed Nomenclature of Epidemic Strains of MRSA in Canada

1999 ◽  
Vol 10 (5) ◽  
pp. 333-336 ◽  
Author(s):  
AE Simor ◽  
D Boyd ◽  
L Louie ◽  
A McGeer ◽  
M Mulvey ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant ◽  
The Past ◽  
Geographic Regions ◽  
Mrsa Strains ◽  
Genotypic Characteristics

The incidence of methicillin-resistantStaphylococcus aureus(MRSA) has been increasing in many Canadian hospitals over the past few years. Some strains may be considered ‘epidemic’, in that they are clinically or epidemiologically significant, and have been identified in patients from multiple hospitals and geographic regions across the country. This paper describes phenotypic and genotypic characteristics of four epidemic MRSA strains in Canada and proposes standardized nomenclature.

scholarly journals Methicillin-Resistant Staphylococcus aureus Recovered from Healthcare- and Community-Associated Infections in Egypt

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Mohamed Abdel-Maksoud ◽  
Mona El-Shokry ◽  
Ghada Ismail ◽  
Soad Hafez ◽  
Amani El-Kholy ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Infection Control ◽  
Continuous Monitoring ◽  
Inhibitory Concentration ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance ◽  
The Past ◽  
Mrsa Strains ◽  
Healthcare Associated ◽  
Over Time

Background. Methicillin-resistant Staphylococcus aureus (MRSA) has created significant epidemiological, infection-control, and therapeutic management challenges during the past three decades. Aim. To analyze the pattern of resistance of healthcare- and community-associated MRSA in Egypt and the trend of resistance of HA-MRSA over time (2005–2013). Methods. MRSA isolates were recovered from healthcare-associated (HA) and community-associated (CA) Staphylococcus aureus (S. aureus) infections. They were tested against 11 antimicrobial discs and the minimal inhibitory concentration (MIC) of vancomycin was determined. Inducible clindamycin resistance (iMLSB) was also screened using D-test. Findings. Of 631 S. aureus, MRSA was identified in 343 (76.6%) and 21 (11.5%) of HA and CA S. aureus isolates, respectively. The proportion of HA-MRSA increased significantly from 48.6% in 2005 to 86.8% in 2013 (p value < 0.001). Multidrug resistance (MDR) was observed in 85.8% of HA-MRSA and 48.6% of CA-MRSA. Vancomycin intermediate resistant S. aureus (VISA) was detected in 1.2% of HA-MRSA and none was detected in CA-MRSA. Among HA-MRSA strains, 5.3% showed iMLSB compared to 9.5% among CA-MRSA. Conclusion. The upsurge of the prevalence rates of HA-MRSA over time is alarming and urges for an effective infection control strategy and continuous monitoring of antimicrobial use.

scholarly journals CIRCULATING CLONES OF COMMUNITY-ACQUIRED METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS (CA-MRSA) IN WESTERN AUSTRALIA IN THE PAST 11 YEARS (2002-2013)

2016 ◽  
Vol 78 (5) ◽  
Author(s):  
A. M. Setiawan
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Disease Prevention ◽  
Infection Control ◽  
Western Australia ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistant ◽  
Health Concerns ◽  
The Past ◽  
Mrsa Strains

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most complicated problems in infection control and disease prevention. Imported strains or group of similar strains called clones were introduced from other states within Australia and also from other countries. Western Australia (WA) MRSA clones known to be the most predominant clones circulating in Western Australia (WA). However, MRSA strains originally from other states and countries outside Australia (imported) have increased in number in the last decades. The aim of this study was to examine the epidemiology of CA MRSA clones in Western Australia for the past 11 year’s period (2003-2013). There were 10 predominant clones of CA-MRSA circulating in WA with WA MRSA-1 (32,82%), Queensland (22,67 %) and WA MRSA-2 (22,67 %) clones as the top three predominant clones. The percentage of PVL positive CA-MRSA clones such as Queensland (Qld) clone has been increasing significantly (R2=0,67) from 2,38 % in 2002 to 25,69% in 2013. In contrast, the percentages of two major PVL negative clones, WA MRSA-1 and WA MRSA 2, have been decreasing nearly by half from 52,38 % to 27,71 % and 30,95 % to 16,59 % respectively in the last 11 years. PVL positive clones have been introduced in WA from other states and overseas in the last eleven years. Due to the virulence factor of PVL toxin, the emergence of PVL positive CA-MRSA should be considered as public health concerns.

scholarly journals Infections Caused By Community-Associated Methicillin-Resistant Staphylococcus Aureus European Clone (ST80) In Slovenia Between 2006 And 2013

2016 ◽  
Vol 55 (2) ◽  
pp. 131-135 ◽  
Author(s):  
Urška Dermota ◽  
Tomaž Jurca ◽  
Tatjana Harlander ◽  
Marta Košir ◽  
Urška Zajc ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
National Level ◽  
Epidemiological Data ◽  
Sequence Type ◽  
Methicillin Resistant ◽  
Exfoliative Toxin ◽  
Type D ◽  
Mrsa Strains ◽  
Genotypic Characteristics ◽  
Microbiological Procedures

Abstract Introduction According to the existing literature, a heterogeneous sequence type (ST) or clones of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) circulate in Europe. In Europe, the European clone that belongs to sequence type ST80 is predominant. Methods The aim of the study was to investigate the phenotypic and genotypic characteristics and epidemiological data of CA-MRSA ST80 and its occurrence in Slovenia. We retrospectively analyzed those CA-MRSA isolates that were isolated during microbiological procedures in microbiological laboratories between 2006 and 2013. Only CA-MRSA isolates from the national collection of CA-MRSA strains that belonged to ST80 (European clone) were analyzed. We determined the Pantone-Valentine leukocidin (PVL), mec A genes, exfoliative toxin genes and type of staphylococcal cassette chromosome (SCCmec) by polymerase chain reaction (PCR). We determined also spa type and sequence type. Results ST80 was confirmed in only 2 (0.5%) out of 385 CA-MRSA isolates, collected in a national collection of CAMRSA. Both isolates were positive for the PVL genes, mec A gene, exfoliative toxin type D gene and SCCmec IV. One CA-MRSA isolate was confirmed in a wound swab taken from a 47-year-old male, and the second was isolated from blood cultures of a 69-year-old female. No epidemiological connections between them were found. Conclusions In Slovenia CA-MRSA infections caused by ST80 are rare. In the future, it is necessary that a surveillance study of CA-MRSA at the national level continues and CA-MRSA be considered as a public health threat.

scholarly journals Bacteria from hypersaline environments: a bioactivity reservoir of anti-methicillin resistant Staphylococcus aureus

2017 ◽  
Author(s):  
Ahmed H. Gad
Keyword(s):  
Staphylococcus Aureus ◽  
Marine Bacteria ◽  
High Throughput Screening ◽  
Hypersaline Environments ◽  
Methicillin Resistant ◽  
The Past ◽  
Biogeographical Distribution ◽  
Diffusion Technique ◽  
Mrsa Strains ◽  
Diverse Groups

In the past decades, novel pharmaceutical compounds have been produced by a wide diverse groups of marine bacteria. These marine bacteria are potential reservoirs for antimicrobial products. In this study, we investigated 40 soil samples collected from the Great Salt Plain of Oklahoma GSP for anti-methicillin resistant Staphylococcus aureus bioactivities. A total number of 499 heterotrophic bacterial isolates (202 mesophilic halotolerant isolates, 125 thermophilic isolates, 84 halophilic isolates and 88 thermophile-halophile isolates) were recovered by culture dependent isolation and subjected to high-throughput screening to investigate their bioactivities against two strains of methicillin resistant Staphylococcus aureus MRSA. A total of 101 isolates (20.2%) out of 499 isolates possessed bioactivities against MRSA strains. They included; eighty (40%) isolates out of the 202 mesophilic halotolerant isolates showed anti-MRSA bioactivity. Twenty one bioactive (7%) isolates out of the 297 enrichment isolates showed anti-MRSA bioactivity. They involved; eleven bioactive (11%) isolates out of 125 of the thermophilic group and ten bioactive isolates (10%) out of 84 halophilic group isolates. No anti-MRSA bioactivity was revealed by the 88 isolates of the thermophile-halophile group. These 101 bioactive isolates (80 mesophilic halotolerant, 11 thermophilic and 10 halophilic) exhibited bioactivities against at least one Staphylococcus aureus MRSA using well diffusion technique. In regard to biogeographical distribution, a total of 29 (29%) and 72 (71%) bioactive isolates were isolated from vegetation and salt flat areas respectively. Thirty four (34%) isolates showed bioactivity against both methicillin resistant Staphylococcus aureus strains and fourteen (14%) isolates showed antimicrobial bioactivity against Staphylococcus aureus B-8-41-D-4, whereas fifty two (52%) isolates revealed antagonism against Staphylococcus aureus 4656. Furthermore, 16S rRNA-based study exposed that, Firmicutes harbored the highest number of bioactive isolates 77 (77%) including Bacillus (n=45 isolates), Halobacillus (n=13 isolates), Virgibacillus (n=7 isolates), Brevibacillus (n=7 isolates), Paenibacillus (n=1 isolates), Sediminibacillus (n=2 isolates), Oceanobacillus (n=1 isolates) and Staphylococcus (n=1 isolate). Proteobacteria- Gammaproteobacteria contained seven bioactive isolates (7%), including Halomonas (n=5 isolates), Marinobacter (n=1 isolate) and Pseudomonas (n=1 isolate). Actinobacteria were the third group and contained two bioactive isolates (2%), including, Cellulomonas (n=1 isolate) and Micrococcus (n=1 isolates). To our knowledge, this is the first study to explore the anti- methicillin resistant Staphylococcus aureus bioactivities of bacteria isolated from GSP. We consider our findings promising for further research to develop novel antimicrobial antibiotics.

scholarly journals Genetic Diversity of Methicillin-Resistant Staphylococcus Aureus Among Japanese Inpatients in the Early 1980s

2020 ◽  
Author(s):  
Hui Zuo ◽  
Yuki Uehara ◽  
Yujie Lu ◽  
Takashi Sasaki ◽  
Keiichi Hiramatsu
Keyword(s):  
Staphylococcus Aureus ◽  
Population Structure ◽  
Methicillin Resistance ◽  
The United States ◽  
Type I ◽  
Methicillin Resistant ◽  
Global Pandemic ◽  
Mrsa Strains ◽  
Healthcare Associated ◽  
Genotypic Characteristics

Abstract Background: Methicillin-resistant Staphylococcus aureus (MRSA) was recognized as a serious nosocomial pathogen in Japan starting in the early 1980s. Limited genotypic characteristics on healthcare-associated MRSA (HA-MRSA) associated with “hospital MRSA panics” in Japan in this era. Therefore, this study aimed to determine the characteristics of Japanese HA-MRSA strains in the early 1980s and their linkage with current MRSA strains.Methods: For 194 S. aureus strains isolated in the early 1980s, we determined methicillin resistance phenotypically and genotypically and performed multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing, and whole-genome sequencing. Results: Twenty mecA-positive MRSA (10.3%), 8 mecA-negative MRSA (4.1%) and 3 mecA-positive methicillin-susceptible S. aureus (MSSA) (1.5%) strains were identified. The frequent sequence type (ST) was ST30 (n=11), followed by ST5 (n=8), ST81 (n=4), and ST247 (n=3). Rates of SCCmec types I, II, and IV were 65.2%, 13.0%, and 17.4%, respectively. ST30-SCCmec I (n=7) and ST5-SCCmec I (n=5) were predominant genotypes. Only two strains exhibited tst-positive ST5-SCCmec II, which is the current Japanese HA-MRSA genotype. Moreover, 73.3% of SCCmec type I strains were susceptible to imipenem compared with SCCmec type II strains (0%). All ST30 strains shared a common ancestor with strain 55/2053, which resulted in a global pandemic of Panto-Valentine leukocidin (PVL)-positive and penicillin-resistant MSSA spread in Europe and the United States in the 1950s. Conclusions: Our results demonstrated the heterogeneous population structure of Japanese HA-MRSA during the early 1980s, which comprised diverse clones that are mostly rare in recent years. The shift to the current homogenous population structure of HA-MRSA strains consisting of tst-positive ST5-SCCmec II might result from the clinical introduction of new antimicrobials including imipenem.

scholarly journals Occurrence and characterisation of methicillin-resistant Staphylococcus aureus isolated from bovine milk in Hungary

2020 ◽  
Author(s):  
Ervin Albert ◽  
Rita Sipos ◽  
Szilárd Jánosi ◽  
Péter Kovács ◽  
Árpád Kenéz ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clonal Complex ◽  
Bovine Milk ◽  
Dairy Farms ◽  
Methicillin Resistant ◽  
The Past ◽  
Strain Collection ◽  
Mrsa Strains ◽  
Milk Hygiene

AbstractThe last surveys on methicillin-resistant Staphylococcus aureus (MRSA) isolated from bovine milk in Hungary took place in the 2000s. To elucidate the genetic variability and to estimate the burden of the pathogen, MRSA from our strain collection and prospectively collected Staphylococcus aureus (SA) isolates originating from two milk hygiene laboratories were investigated. Between 2003 and 2018, 27 MRSA strains originating from 10 dairy farms were deposited and characterised. Most strains (n = 20) belonged to ST1-t127-SCCmecIV and were recovered from three unrelated farms. From other farms, variable genotypes were identified sporadically: ST22-t032-SCCmecIV from three farms; a newly described double locus variant of ST97, ST5982-t458-SCCmecIV from two farms; and ST398-t011-SCCmecIV and ST398-t011-SCCmecV from two respective farms. The prospective screening of 626 individual SA isolates originating from 42 dairy farms resulted in four (0.48 %) MRSA strains from three (7.14 %) farms. All MRSA isolates belonged to the clonal complex 398 and a novel spa-type t19251 was also identified. Most isolates were resistant to three or more antimicrobial classes. The occurrence and significance of MRSA of dairy origin seems to be unchanged in the past decade in Hungary. However, the low host specificity and multiresistance of the identified genotypes calls for periodic revision on the role and distribution of the pathogen in the Hungarian dairy sector.

scholarly journals Antibiotic Resistance, spa Typing and Clonal Analysis of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates from Blood of Patients Hospitalized in the Czech Republic

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 395
Author(s):  
Katarina Pomorska ◽  
Vladislav Jakubu ◽  
Lucia Malisova ◽  
Marta Fridrichova ◽  
Martin Musilek ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Czech Republic ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Bloodstream Infections ◽  
Spa Typing ◽  
The Czech Republic ◽  
Methicillin Resistant ◽  
Mrsa Strains ◽  
Spa Types ◽  
Repeat Pattern

Staphylococcus aureus is one of the major causes of bloodstream infections. The aim of our study was to characterize methicillin-resistant Staphylococcus aureus (MRSA) isolates from blood of patients hospitalized in the Czech Republic between 2016 and 2018. All MRSA strains were tested for antibiotic susceptibility, analyzed by spa typing and clustered using a Based Upon Repeat Pattern (BURP) algorithm. The representative isolates of the four most common spa types and representative isolates of all spa clonal complexes were further typed by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. The majority of MRSA strains were resistant to ciprofloxacin (94%), erythromycin (95.5%) and clindamycin (95.6%). Among the 618 strains analyzed, 52 different spa types were detected. BURP analysis divided them into six different clusters. The most common spa types were t003, t586, t014 and t002, all belonging to the CC5 (clonal complex). CC5 was the most abundant MLST CC of our study, comprising of 91.7% (n = 565) of spa-typeable isolates. Other CCs present in our study were CC398, CC22, CC8, CC45 and CC97. To our knowledge, this is the biggest nationwide study aimed at typing MRSA blood isolates from the Czech Republic.

scholarly journals Restoration of Susceptibility of Intracellular Methicillin-Resistant Staphylococcus aureus to β-Lactams: Comparison of Strains, Cells, and Antibiotics

2008 ◽  
Vol 52 (8) ◽  
pp. 2797-2805 ◽  
Author(s):  
Sandrine Lemaire ◽  
Aurélie Olivier ◽  
Françoise Van Bambeke ◽  
Paul M. Tulkens ◽  
Peter C. Appelbaum ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dose Response ◽  
Intermediate Phenotype ◽  
Maximal Effect ◽  
Response Curves ◽  
Methicillin Resistant ◽  
Complete Restoration ◽  
Similar Dose ◽  
Dose Response Curves ◽  
Mrsa Strains

ABSTRACT Staphylococcus aureus invades eukaryotic cells. When methicillin-resistant S. aureus (MRSA) ATCC 33591 is phagocytized by human THP-1 macrophages, complete restoration of susceptibility to cloxacillin and meropenem is shown and the strain becomes indistinguishable from MSSA ATCC 25923 due to the acid pH prevailing in phagolysosomes (S. Lemaire et al., Antimicrob. Agents Chemother. 51:1627-1632, 2007). We examined whether this observation can be extended to (i) strains of current clinical and epidemiological interest (three hospital-acquired MRSA [HA-MRSA] strains, two community-acquired MRSA [CA-MRSA] strains, two HA-MRSA strains with the vancomycin-intermediate phenotype, one HA-MRSA strain with the vancomycin-resistant phenotype, and one animal [porcine] MRSA strain), (ii) activated THP-1 cells and nonprofessional phagocytes (keratinocytes, Calu-3 bronchial epithelial cells), and (iii) other β-lactams (imipenem, oxacillin, cefuroxime, cefepime). All strains showed (i) a marked reduction in MICs in broth at pH 5.5 compared with the MIC at pH 7.4 and (ii) sigmoidal dose-response curves with cloxacillin (0.01× to 100× MIC, 24 h of incubation) after phagocytosis by THP-1 macrophages that were indistinguishable from each other and from the dose-response curve for methicillin-susceptible S. aureus (MSSA) ATCC 25923 (relative potency [50% effect], 6.09× MIC [95% confidence interval {CI}, 4.50 to 8.25]; relative efficacy [change in bacterial counts over the original inoculum for an infinitely large cloxacillin concentration, or maximal effect], −0.69 log CFU [95% CI, −0.79 to −0.58]). Similar dose-response curves for cloxacillin were also observed with MSSA ATCC 25923 and MRSA ATCC 33591 after phagocytosis by activated THP-1 macrophages, keratinocytes, and Calu-3 cells. By contrast, there was a lower level of restoration of susceptibility of MRSA ATCC 33591 to cefuroxime and cefepime after phagocytosis by THP-1 macrophages, even when the data were normalized for differences in MICs. We conclude that the restoration of MRSA susceptibility to β-lactams after phagocytosis is independent of the strain and the types of cells but varies between β-lactams.

scholarly journals Evaluation of Ceftaroline Alone and in Combination against Biofilm-Producing Methicillin-Resistant Staphylococcus aureus with Reduced Susceptibility to Daptomycin and Vancomycin in anIn VitroPharmacokinetic/Pharmacodynamic Model

2015 ◽  
Vol 59 (8) ◽  
pp. 4497-4503 ◽  
Author(s):  
Katie E. Barber ◽  
Jordan R. Smith ◽  
Cortney E. Ireland ◽  
Blaise R. Boles ◽  
Warren E. Rose ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Device ◽  
Bloodstream Infections ◽  
Methicillin Resistant ◽  
Content Type ◽  
Elimination Half ◽  
Antimicrobial Protection ◽  
Mrsa Strains ◽  
Post Hoc

ABSTRACTAnnually, medical device infections are associated with >250,000 catheter-associated bloodstream infections (CLABSI), with up to 25% mortality.Staphylococcus aureus, a primary pathogen in these infections, is capable of biofilm production, allowing organism persistence in harsh environments, offering antimicrobial protection. With increases inS. aureusisolates with reduced susceptibility to current agents, ceftaroline (CPT) offers a therapeutic alternative. Therefore, we evaluated whether CPT would have a role against biofilm-producing methicillin-resistantS. aureus(MRSA), including those with decreased susceptibilities to alternative agents. In this study, we investigated CPT activity alone or combined with daptomycin (DAP) or rifampin (RIF) against 3 clinical biofilm-producing MRSA strains in anin vitrobiofilm pharmacokinetic/pharmacodynamic (PK/PD) model. Simulated antimicrobial regimens were as follows: 600 mg of CPT every 8 h (q8h) (free maximum concentration of drug [fCmax], 17.04 mg/liter; elimination half-life [t1/2], 2.66 h), 12 mg/kg of body weight/day of DAP (fCmax, 14.7 mg/liter;t1/2, 8 h), and 450 mg of RIF q12h (fCmax, 3.5 mg/liter;t1/2, 3.4 h), CPT plus DAP, and CPT plus RIF. Samples were obtained and plated to determine colony counts. Differences in log10CFU/cm2were evaluated by analysis of variance with Tukey'spost hoctest. The strains were CPT and vancomycin susceptible and DAP nonsusceptible (DNS). CPT displayed activity throughout the experiment. DAP demonstrated initial activity with regrowth at 24 h in all strains. RIF was comparable to the drug-free control, and little benefit was observed when combined with CPT. CPT plus DAP displayed potent activity, with an average log10CFU/cm2reduction of 3.33 ± 1.01 from baseline. CPT demonstrated activity against biofilm-producing DNS MRSA. CPT plus DAP displayed therapeutic enhancement over monotherapy, providing a potential option for difficult-to-treat medical device infections.

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