scholarly journals Genotypic diversity between surgical and nasal Staphylococcus aureus isolates

2020 ◽  
Author(s):  
Dongzhu Ma ◽  
Patrick L. Maher ◽  
Kimberly M. Brothers ◽  
Nathan J. Phillips ◽  
Deborah Simonetti ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Joint Infection ◽  
Parallel Evolution ◽  
Genotypic Diversity ◽  
Nasal Carriage ◽  
Host Immune System ◽  
Host Status ◽  
Fibronectin Binding ◽  
Two Populations ◽  
Atypical Strains

AbstractStaphylococcus aureus is a common organism in periprosthetic joint infection (PJI). Little is known about S. aureus genetic diversity in PJI as compared to nasal carriage. We hypothesized PJI S. aureus strains would be associated with increased virulence as compared to those from nasal carriage. Whole genome sequencing and multilocus sequence typing (MLST) was performed to genotype these two populations at high resolution. MLST revealed a variety of genotypes in both populations but many belonged to the most common clonal complexes. In nasal cultures, 69% of strains were of clonal complexes CC5, CC8, and CC30. In PJI cultures, only 51% could be classified in these common clonal complexes. Remaining strains were atypical, and these atypical strains in PJI were associated with poor host status and compromised immune conditions. Mutations in genes involved in fibronectin binding (ebh, fnbA, clfA, clfB) systematically distinguished later PJI isolates from the first PJI isolate from each patient. S. aureus isolated from nasal carriage and PJI specimens differ significantly, with the latter being more diverse. Strains associated with lower pathogenicity tended to be found in immunocompromised patients, suggesting the host immune system plays an important role in preventing PJI. Repeated mutations in S. aureus genes associated with extracellular matrix binding were identified suggesting an adaptive, parallel evolution in S. aureus during the development of PJI.

scholarly journals Staphylococcus aureus Internalization in Osteoblast Cells: Mechanisms, Interactions and Biochemical Processes. What Did We Learn from Experimental Models?

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 239
Author(s):  
Stefano Stracquadanio ◽  
Nicolò Musso ◽  
Angelita Costantino ◽  
Lorenzo Mattia Lazzaro ◽  
Stefania Stefani ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune System ◽  
Current Knowledge ◽  
Bacterial Species ◽  
Joint Infection ◽  
Experimental Models ◽  
System Response ◽  
Osteoblastic Cell ◽  
Host Immune System ◽  
Osteoblastic Cell Line

Bacterial internalization is a strategy that non-intracellular microorganisms use to escape the host immune system and survive inside the human body. Among bacterial species, Staphylococcus aureus showed the ability to interact with and infect osteoblasts, causing osteomyelitis as well as bone and joint infection, while also becoming increasingly resistant to antibiotic therapy and a reservoir of bacteria that can make the infection difficult to cure. Despite being a serious issue in orthopedic surgery, little is known about the mechanisms that allow bacteria to enter and survive inside the osteoblasts, due to the lack of consistent experimental models. In this review, we describe the current knowledge about S. aureus internalization mechanisms and various aspects of the interaction between bacteria and osteoblasts (e.g., best experimental conditions, bacteria-induced damages and immune system response), focusing on studies performed using the MG-63 osteoblastic cell line, the best traditional (2D) model for the study of this phenomenon to date. At the same time, as it has been widely demonstrated that 2D culture systems are not completely indicative of the dynamic environment in vivo, and more recent 3D models—representative of bone infection—have also been investigated.

scholarly journals Staphylococcus aureus Internalization in Osteoblast Cells: Mechanisms, Interactions and Biochemical Processes. What did We Learn from Experimental Models?

2020 ◽  
Author(s):  
Nicolò Musso ◽  
Stefano Stracquadanio ◽  
Angelita Costantino ◽  
Lorenzo Mattia Lazzaro ◽  
Stefania Stefani ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune System ◽  
Current Knowledge ◽  
Joint Infection ◽  
Experimental Models ◽  
System Response ◽  
Osteoblastic Cell ◽  
Host Immune System ◽  
Experimental Conditions ◽  
Osteoblastic Cell Line

Bacterial internalization is a strategy that non-intracellular microorganisms use to escape the host immune system and survive inside the human body. Among bacteria species, Staphylococcus aureus showed ability to interact and infect osteoblasts causing osteomyelitis as well as bone and joint infection, while also becoming increasingly resistant to antibiotic therapy and a reservoir of bacteria that can make the infection difficult to cure. Despite being a serious issue in orthopedic surgery, little is known about the mechanisms that allow bacteria to enter and survive inside the osteoblasts, also due to the lack of consistent experimental models. In this review, we describe the current knowledge about S. aureus internalization mechanisms and various aspects of the interaction between bacteria and osteoblasts (e.g. best experimental conditions, bacteria-induced damages and immune system response), focusing on studies performed using the MG-63 osteoblastic cell line, so far the best model for the study of this phenomenon.

scholarly journals Genotypic and Phenotypic Characteristics of Staphylococcus aureus Prosthetic Joint Infections: Insight on the Pathogenesis and Prognosis of a Multicenter Prospective Cohort

2020 ◽  
Vol 7 (9) ◽  
Author(s):  
Irene Muñoz-Gallego ◽  
Esther Viedma ◽  
Jaime Esteban ◽  
Mikel Mancheño-Losa ◽  
Joaquín García-Cañete ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Joint Infection ◽  
Genotypic Diversity ◽  
Symptom Duration ◽  
Chronic Infections ◽  
Phenotypic Characteristics ◽  
Joint Infections ◽  
Prosthetic Joint ◽  
Microbiological Characteristics ◽  
Prosthetic Joint Infections

Abstract Background Staphylococcus aureus is the leading cause of prosthetic joint infection (PJI). Beyond the antibiogram, little attention has been paid to the influence of deep microbiological characteristics on patient prognosis. Our aim was to investigate whether microbiological genotypic and phenotypic features have a significant influence on infection pathogenesis and patient outcome. Methods A prospective multicenter study was performed, including all S. aureus PJIs (2016–2017). Clinical data and phenotypic (agr functionality, β-hemolysis, biofilm formation) and genotypic characteristics of the strains were collected. Biofilm susceptibility to antimicrobials was investigated (minimal biofilm eradication concentration [MBEC] assay). Results Eighty-eight patients (39.8% men, age 74.7 ± 14.1 years) were included. Forty-five had early postoperative infections (EPIs), 21 had chronic infections (CPIs), and 19 had hematogenous infections (HIs). Twenty (22.7%) were caused by methicillin-resistant S. aureus. High genotypic diversity was observed, including 16 clonal complexes (CCs), with CC5 being the most frequent (30.7%). agr activity was greater in EPI than CPI (55.6% vs 28.6%; P = .041). Strains causing EPI were phenotypically and genotypically similar, regardless of symptom duration. Treatment failure (36.5%) occurred less frequently among cases treated with implant removal. In cases treated with debridement and implant retention, there were fewer failures among those who received combination therapy with rifampin. No genotypic or phenotypic characteristics predicted failure, except vancomycin minimal inhibitory concentration ≥1.5 mg/L (23.1% failure vs 3.4%; P = .044). MBEC50 was >128 mg/L for all antibiotics tested and showed no association with prognosis. Conclusions S. aureus with different genotypic backgrounds is capable of causing PJI, showing slight differences in clinical presentation and pathogenesis. No major microbiological characteristics were observed to influence the outcome, including MBEC.

scholarly journals Bacterial carriage of genes encoding fibronectin-binding proteins is associated with long-term persistence of Staphylococcus aureus in the nasal and gut microbiota of infants

2021 ◽  
Author(s):  
Forough L. Nowrouzian ◽  
Annika Ljung ◽  
Bill Hesselmar ◽  
Staffan Nilsson ◽  
Ingegerd Adlerberth ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gut Microbiota ◽  
Virulence Factors ◽  
Current Knowledge ◽  
Nasal Carriage ◽  
Pathogenic Potential ◽  
Gut Colonization ◽  
Genes Encoding ◽  
Fibronectin Binding

Staphylococcus aureus can colonize both the anterior nares and the gastrointestinal tract. However, colonization at these sites in the same individuals has not been studied, and the traits that facilitate colonization and persistence at these sites have not been compared. Samples from the nostrils and fecal collected on 9 occasions from 3 days to 3 years of age in 65 infants were cultured; 54 samples yielded S. aureus. The numbers of nasal and fecal S. aureus increased rapidly during the first weeks and were similar at 1 month of age (>40% of infants colonized). Thereafter, nasal carriage declined, while fecal carriage remained high during the first year of life. Individual strains were identified and their colonization patterns were related to their carriage of genes encoding adhesins and superantigenic toxins. Strains retrieved from both the nose and gut (n=44) of an infant were 4.5-times more likely to colonize long-term (≥3 weeks at both sites) than strains found only in the rectum/feces (n=56) or only in the nose (n=32) (P≤0.001). Gut colonization was significantly associated with carriage of the fnbA gene, and long-term colonization at either site was associated with carriage of fnbA and fnbB. In summary, gut colonization by S. aureus was more common than nasal carriage by S. aureus in the studied infants. Gut strains may provide a reservoir for invasive disease in vulnerable individuals. Fibronectin-binding adhesins and other virulence factors may facilitate commensal colonization and confer pathogenic potential. IMPORTANCE S. aureus may cause severe infections and frequently colonizes the nose. Nasal carriage of S. aureus increases three-fold the risk of invasive S. aureus infection. S. aureus is also commonly found in the gut microbiota of infants and young children. However, the relationships between the adhesins and other virulence factors of S. aureus strains and its abilities to colonize the nostrils and gut of infants are not well-understood. Our study explores the simultaneous colonization by S. aureus of the nasal and intestinal tracts of newborn infants, through 3 years of follow-up. We identify bacterial virulence traits that appear to facilitate persistent colonization of the nose and gut by S. aureus. This expands our current knowledge of the interplay between bacterial commensalism and pathogenicity. Moreover, it may contribute to the development of targeted strategies for combating S. aureus infection.

scholarly journals Nasal carriage of Staphylococcus aureus among a healthy suburban population: genotypic diversity and frequency of pathogenicity genes

2021 ◽  
Vol 9 (5) ◽  
pp. 159-165
Author(s):  
Luis Jimenez ◽  
Sibora Peca ◽  
Joy Bochis ◽  
Jenifer Vasquez ◽  
Stephanie Zapata ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Genotypic Diversity ◽  
Nasal Carriage ◽  
Pathogenicity Genes

Staphylococcus aureus nasal colonization among Vietnamese adults: prevalence, risk factors and antibiotic susceptibility profile

MedPharmRes ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 21-31
Author(s):  
Nguyen Phan ◽  
Hien Pham ◽  
Thuc Nguyen ◽  
Hoai Nguyen
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Antibiotic Susceptibility ◽  
Nasal Carriage ◽  
Resistance Rate ◽  
High Rate ◽  
Weight History ◽  
Potential Risk Factors ◽  
History Of ◽  
Vietnamese Community

Staphylococcus aureus (S. aureus) has long been recognized as an important human pathogen causing many severe diseases. It is also a part of human normal flora with its ecological niche in the human anterior nares. This study focused on screening S. aureus nasal carriage in community and its relationship to human physiological and pathological factors which have not been studied in Vietnam previously. Two hundred and five volunteers in Ho Chi Minh City from 18 to 35 and over 59 years old both male and female participated in the study. Result showed that the prevalence of S. aureus nasal carriage in southern Vietnamese community was relatively low, only 11.2% (23/205), much lower than that in other international reports on human S. aureus. In addition, nasal carriage of the older age group (> 59 years old, 13.7%) was higher than that of younger age (18-35 years old, 10.4%). Other potential risk factors such as gender, career, height, weight, history of antibiotic usage, daily nasal wash, use of nasal medication sprays, acne problems, smoking and nasal problems showed no significant impact on S. aureus carriage. The obtained S. aureus nasal isolates were all sensitive to vancomycin. Lincomycin and tetracycline had low resistance rate with 4.3 % and 17.4 %, respectively. However, the isolates showed particularly high rate of multidrug resistance (54.2%) In summary, our data provided researchers an overview on S. aureus nasal carriage and antibiotic susceptibility profile of the community- isolated S. aureus in Vietnam. This would serve as valuable information on assessing risk of community-acquired S. aureus infections.

NASAL CARRIAGE OF STAPHYLOCOCCUS AUREUS AS A RISK OF NOSOCOMIAL INFECTIONS

2014 ◽  
Vol 5 (4) ◽  
pp. 205-209
Author(s):  
MAŁGORZATA M. KOZIOŁ ◽  
AGNIESZKA SIKORA ◽  
SYLWIA TARGOŃSKA ◽  
ANNA SIKORA
Keyword(s):  
Staphylococcus Aureus ◽  
Nosocomial Infections ◽  
Nasal Carriage
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