scholarly journals Staphylococcus aureus as an infectious agent: overview of biochemistry and molecular genetics of its pathogenicity.

2009 ◽  
Vol 56 (4) ◽  
Author(s):  
Konrad Plata ◽  
Adriana E Rosato ◽  
Grzegorz Wegrzyn
Keyword(s):  
Staphylococcus Aureus ◽  
Human Population ◽  
Infectious Agent ◽  
Healthcare Associated Infections ◽  
Regulation Of Expression ◽  
Expression Of Genes ◽  
Genetic Mechanisms ◽  
Mrsa Strains ◽  
Etiological Agents ◽  
Healthcare Associated

Although it is estimated that 20-30% of the general human population are carriers of Staphylococcus aureus, this bacterium is one of the most important etiological agents responsible for healthcare-associated infections. The appearance of methicillin resistant S. aureus (MRSA) strains has created serious therapeutical problems. Detailed understanding of the mechanisms of S. aureus infections seems necessary to develop new effective therapies against this pathogen. In this article, we present an overview of the biochemical and genetic mechanisms of pathogenicity of S. aureus strains. Virulence factors, organization of the genome and regulation of expression of genes involved in virulence, and mechanisms leading to methicilin resistance are presented and briefly discussed.

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 Methicillin-resistant Staphylococcus aureus nasal cariage among hospitalized patients and healthcare workers in the Clinical center of Serbia

2014 ◽  
Vol 66 (1) ◽  
pp. 87-92 ◽  
Author(s):  
Ivana Cirkovic ◽  
Slobodanka Djukic ◽  
Biljana Carevic ◽  
Natasa Mazic ◽  
Vesna Mioljevic ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Healthcare Workers ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Healthcare Facility ◽  
Comprehensive Analysis ◽  
Hospitalized Patients ◽  
Methicillin Resistant ◽  
Clinical Center ◽  
Mrsa Strains ◽  
Healthcare Associated

The aim of the present study was to provide the first comprehensive analysis of methicillin-resistant Staphylococcus aureus (MRSA) carriage among patients and healthcare workers (HCWs) in the largest healthcare facility in Serbia. Specimens from anterior nares obtained from 195 hospitalized patients and 105 HCWs were inoculated after broth enrichment onto chromogenic MRSA-ID medium. In total, 21 of 300 specimens yielded MRSA. Among hospitalized patients, 7.7% were colonized with MRSA, and 5.7% HCWs were colonized with MRSA. Five out of 21 (23.8%) tested MRSA strains were classified as community-associated MRSA (CA-MRSA), and four of them were isolated from HCWs. The remaining 16 MRSA strains had characteristics of healthcare-associated MRSA (HA-MRSA), and two of them were isolated from HCWs. The HA-MRSA strains isolated from HCWs were indistinguishable from HA-MRSA of the same cluster isolated from patients. This finding reveals the circulation of HA-MRSA strains between patients and HCWs in the Clinical Center of Serbia.

scholarly journals Everybody Nose: Molecular and Clinical Characteristics of Nasal Colonization During Active Methicillin-Resistant Staphylococcus Aureus Bloodstream Infection

2021 ◽  
Author(s):  
Erika Reategui Schwarz ◽  
Adriana van de Guchte ◽  
Amy C. Dupper ◽  
Ana Berbel Caban ◽  
Devika Nadkarni ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bloodstream Infection ◽  
Bloodstream Infections ◽  
Invasive Disease ◽  
Nasal Colonization ◽  
Healthcare Associated Infections ◽  
Staphylococcal Protein A ◽  
Record System ◽  
Methicillin Resistant ◽  
Healthcare Associated

Abstract Background. Healthcare-associated infections pose a potentially fatal threat to patients worldwide and Staphylococcus aureus is one of the most common causes of healthcare-associated infections. S. aureus is a common commensal pathogen and a frequent cause of bacteremia, with studies demonstrating that nasal and blood isolates from single patients match more than 80% of the time. Here we report on a contemporary collection of colonizing isolates from those with methicillin-resistant S. aureus (MRSA) bloodstream infections to evaluate the diversity within hosts, and detail the clinical features associated with concomitant nasal colonization.Methods. Swabs of the bilateral anterior nares were obtained from patients diagnosed with MRSA bacteremia. A single colony culture from the blood and an average of 6 colonies from the nares were evaluated for MRSA growth. For the nares cultures, we typed multiple isolates for staphylococcal protein A (spa) and derived the clonal complexes. Demographic and clinical data were obtained retrospectively from the electronic medical record system and analysed using univariate and multivariable regression models.Results. Over an 11-month period, 68 patients were diagnosed with MRSA bloodstream infection, 53 were swabbed, and 37 (70%) were colonized with MRSA in the anterior nares. We performed molecular typing on 210 nasal colonies. Spa types and clonal complexes found in the blood were also detected in the nares in 95% of the cases. We also found that 11% of patients carried more than one clone of MRSA in the nares. Male sex and history of prior hospitalization within the past 90 days increased odds for MRSA colonization. Conclusion. The molecular epidemiological landscape of colonization in the setting of invasive disease is diverse and defining the interplay between colonization and invasive disease is critical to combating invasive MRSA disease.

scholarly journals Methicillin-resistant Staphylococcus aureus in veterinary professionals in 2017 in the Czech Republic

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Katerina Neradova ◽  
Vladislav Jakubu ◽  
Katarina Pomorska ◽  
Helena Zemlickova
Keyword(s):  
Staphylococcus Aureus ◽  
Czech Republic ◽  
Nasal Carriage ◽  
The Czech Republic ◽  
Methicillin Resistant ◽  
Nasal Swabs ◽  
Mrsa Strains ◽  
Healthcare Associated ◽  
Mrsa Colonization ◽  
Animal Strains

Abstract Background Cases of colonization or infection caused by Methicillin-resistant Staphylococcus aureus (MRSA) are frequently reported in people who work with animals, including veterinary personnel. The aim of this study was to determine the prevalence of MRSA colonization among veterinary professionals. A total of 134 nasal swabs from healthy attendees of a veterinary conference held in the Czech Republic were tested for presence of MRSA. The stains were further genotypically and phenotypically characterized. Results Nine isolated MRSA strains were characterized with sequence type (ST), spa type (t) and Staphylococcal Cassette Chromosome mec type. Five different genotypes were described, including ST398-t011-IV (n = 5), ST398-t2330-IV (n = 1), ST398-t034-V (n = 1), ST225-t003-II (n = 1) and ST4894-t011-IV (n = 1). The carriage of the animal MRSA strain was confirmed in 8 cases, characteristics of one strain corresponded to the possible nosocomial origin. Among animal strains were described three spa types (t011, t034, t2330) belonging into one dominating clonal complex spa-CC11. Conclusion According to our results, the prevalence of nasal carriage of MRSA in veterinary personnel is 6.72%. Although we described an increase compared to the results of previous study (year 2008), the prevalence in the Czech Republic is still remaining lower than reported from neighboring countries. Our results also indicate that healthcare - associated MRSA strains are still not spread among animals.

scholarly journals Control of Methicillin-Resistant Staphylococcus aureus Strains Associated With a Hospital Outbreak Involving Contamination From Anesthesia Equipment Using UV-C

2020 ◽  
Vol 11 ◽  
Author(s):  
Sara A. Ochoa ◽  
Ariadnna Cruz-Córdova ◽  
Jetsi Mancilla-Rojano ◽  
Gerardo Escalona-Venegas ◽  
Veronica Esteban-Kenel ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Opportunistic Pathogen ◽  
Type Ii ◽  
Methicillin Resistant ◽  
Hospital Outbreak ◽  
Anesthesia Equipment ◽  
Mrsa Strains ◽  
Healthcare Associated ◽  
Uv C ◽  
Sequence Types

Methicillin-resistant Staphylococcus aureus (MRSA) is considered an opportunistic pathogen in humans and is mainly associated with healthcare-associated infections (HCAIs). This bacterium colonizes the skin and mucous membranes of healthy people and causes frequent hospital outbreaks. The aim of this study was to perform molecular typing of the staphylococcal cassette chromosome mec (SCCmec) and agr loci as wells as to establish the pulsotypes and clonal complexes (CCs) for MRSA and methicillin-sensitive S. aureus (MSSA) outbreaks associated with the operating room (OR) at a pediatric hospital. Twenty-five clinical strains of S. aureus (19 MRSA and 6 MSSA strains) were recovered from the outbreak (patients, anesthesia equipment, and nasopharyngeal exudates from external service anesthesia technicians). These clinical S. aureus strains were mainly resistant to benzylpenicillin (100%) and erythromycin (84%) and were susceptible to vancomycin and nitrofurantoin. The SCCmec type II was amplified in 84% of the S. aureus strains, and the most frequent type of the agr locus was agrII, which was amplified in 72% of the strains; however, the agrI and agrIII genes were mainly detected in MSSA strains. A pulsed-field gel electrophoresis (PFGE) analysis grouped the 25 strains into 16 pulsotypes (P), the most frequent of which was P1, including 10 MRSA strains related to the anesthesia equipment, external service anesthesia technicians, and hospitalized patients. Multilocus sequence typing (MLST) identified 15 sequence types (STs) distributed in nine CCs. The most prevalent ST was ST1011, belonging to CC5, which was associated with the SCCmec type II and agrII type. We postulate that the external service anesthesia technicians were MRSA carriers and that these strains were indirectly transmitted from the contaminated anesthesia equipment that was inappropriately disinfected. Finally, the MRSA outbreak was controlled when the anesthesia equipment disinfection was improved and hand hygiene was reinforced.

scholarly journals Methicillin-resistant Staphylococcus aureus in veterinary professionals in 2017 in the Czech Republic

2019 ◽  
Author(s):  
Katerina Neradova ◽  
Vladislav Jakubu ◽  
Katarina Pomorska ◽  
Helena Zemlickova
Keyword(s):  
Staphylococcus Aureus ◽  
Czech Republic ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Nasal Carriage ◽  
The Czech Republic ◽  
Methicillin Resistant ◽  
Nasal Swabs ◽  
Mrsa Strains ◽  
Healthcare Associated ◽  
Mrsa Colonization

Abstract Background Cases of colonization or infection caused by Methicillin-resistant Staphylococcus aureus (MRSA) are frequently reported in people who work with animals, including veterinary personnel. The aim of this study was to determine the prevalence of MRSA colonization among veterinary professionals. A total of 134 nasal swabs from healthy attendees of a veterinary conference held in the Czech Republic were tested for presence of MRSA. The stains were further genotypically and phenotypically characterized. Results Nine isolated MRSA strains were characterized with sequence type (ST), spa type (t) and Staphylococcal Cassette Chromosome mec type. Five different genotypes were described, including ST398-t011-IV (n=5), ST398-t2330-IV (n=1), ST398-t034-V (n=1), ST225-t003-II (n=1) and ST4894-t011-IV (n=1). The carriage of the animal MRSA strain was confirmed in 8 cases, characteristics of one strain corresponded to the possible nosocomial origin. Among animal strains were described three spa types (t011, t034, t2330) belonging into one dominating clonal complex CC11. Conclusion According to our results, the prevalence of nasal carriage of MRSA in veterinary personnel is 6.72%. Although we described an increase compared to the results of previous study (year 2008), the prevalence in the Czech Republic is still remaining lower than reported from neighboring countries. Our results also indicate that healthcare - associated MRSA strains are still not spread among animals.

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