ANALYSIS OF STAPHYLOCOCCUS AUREUS CARRYING THE LEUKOTOXIN GENES AND IMMUNE EVASION CLUSTER PREVALENCE IN PATIENTS WITH ATOPIC DERMATITIS AND HEALTHY CHILDREN

2019 ◽  
Vol 98 (3) ◽  
pp. 93-98
Author(s):  
T.A. Tikhomirov ◽  
◽  
O.A. Dmitrenko ◽  
N.I. Fedorova ◽  
A.A. Tikhomirov ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Atopic Dermatitis ◽  
Immune Evasion ◽  
Healthy Children ◽  
Immune Evasion Cluster

Presence of Immune Evasion Cluster and Molecular Typing of Methicillin-Susceptible Staphylococcus aureus Isolated from Food Handlers

2016 ◽  
Vol 79 (4) ◽  
pp. 682-686 ◽  
Author(s):  
LÍVIA G. BAPTISTÃO ◽  
NATHALIA C. C. SILVA ◽  
ERIKA C. R. BONSAGLIA ◽  
BRUNA F. ROSSI ◽  
IVANA G. CASTILHO ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Evasion ◽  
Close Contact ◽  
Meca Gene ◽  
Low Frequency ◽  
Food Handlers ◽  
Spa Typing ◽  
Typing Method ◽  
Spa Types ◽  
Immune Evasion Cluster

ABSTRACT The hands and noses of food handlers colonized by Staphylococcus aureus are an important source of food contamination in restaurants and food processing. Several virulence factors can be carried by mobile elements in strains of S. aureus, including the immune evasion cluster (IEC). This gene cluster improves the capacity of S. aureus to evade the human immune response. Many studies have reported the transmission of strains between animals and humans, such as farm workers that have close contact with livestock. However, there are few studies on the transmission between food and food handlers. The aim of this study was to detect the IEC and the mecA gene in strains isolated from food handlers and to type these strains using the spa typing method. Thirty-five strains of S. aureus isolated from the noses and hands of food handlers in three different kitchens were analyzed for the presence of the mecA gene and IEC and by spa typing. All strains were negative for the mecA gene, and the presence of IEC was observed in 10 (28.6%) strains. Fifteen different spa types were observed, with the most frequent being t127 (42.85%) and t002 (11.42%). Strains from the two most prevalent spa types and a novel spa type were typed by multilocus sequence typing. spa types t127, t002, and t13335 were determined to be multilocus sequence types (ST) ST-30, ST-5, and ST-45, respectively. The food handlers may have been contaminated by these strains of S. aureus through food, which is suggested by the low frequency of IEC and by ST that are observed more commonly in animals.

scholarly journals Clumping Factor B Promotes Adherence of Staphylococcus aureus to Corneocytes in Atopic Dermatitis

2017 ◽  
Vol 85 (6) ◽  
Author(s):  
Orla M. Fleury ◽  
Maeve A. McAleer ◽  
Cécile Feuillie ◽  
Cécile Formosa-Dague ◽  
Emily Sansevere ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Atopic Dermatitis ◽  
Clonal Complex ◽  
Ex Vivo ◽  
Nasal Carriage ◽  
Binding Activity ◽  
Clinical Strain ◽  
Healthy Children ◽  
Content Type ◽  
Force Microscopy

ABSTRACT Staphylococcus aureus skin infection is a frequent and recurrent problem in children with the common inflammatory skin disease atopic dermatitis (AD). S. aureus colonizes the skin of the majority of children with AD and exacerbates the disease. The first step during colonization and infection is bacterial adhesion to the cornified envelope of corneocytes in the outer layer, the stratum corneum. Corneocytes from AD skin are structurally different from corneocytes from normal healthy skin. The objective of this study was to identify bacterial proteins that promote the adherence of S. aureus to AD corneocytes. S. aureus strains from clonal complexes 1 and 8 were more frequently isolated from infected AD skin than from the nasal cavity of healthy children. AD strains had increased ClfB ligand binding activity compared to normal nasal carriage strains. Adherence of single S. aureus bacteria to corneocytes from AD patients ex vivo was studied using atomic force microscopy. Bacteria expressing ClfB recognized ligands distributed over the entire corneocyte surface. The ability of an isogenic ClfB-deficient mutant to adhere to AD corneocytes compared to that of its parent clonal complex 1 clinical strain was greatly reduced. ClfB from clonal complex 1 strains had a slightly higher binding affinity for its ligand than ClfB from strains from other clonal complexes. Our results provide new insights into the first step in the establishment of S. aureus colonization in AD patients. ClfB is a key adhesion molecule for the interaction of S. aureus with AD corneocytes and represents a target for intervention.

scholarly journals Prevalence and Genetic Characteristics of Staphylococcus aureus CC398 Isolates From Invasive Infections in Spanish Hospitals, Focusing on the Livestock-Independent CC398-MSSA Clade

2021 ◽  
Vol 12 ◽  
Author(s):  
Olouwafemi Mistourath Mama ◽  
Carmen Aspiroz ◽  
Laura Ruiz-Ripa ◽  
Sara Ceballos ◽  
Maria Iñiguez-Barrio ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Evasion ◽  
Statistical Significance ◽  
Blood Cultures ◽  
Human Adaptation ◽  
Genetic Characteristics ◽  
Invasive Infections ◽  
Human Immune ◽  
Epidemiological Characteristics ◽  
Immune Evasion Cluster

BackgroundLivestock-associated (LA)-CC398-MRSA is closely related to pigs, being unfrequently detected in human invasive infections. CC398-MSSA is emerging in human invasive infections in some countries, but genetic and epidemiological characteristics are still scarcely reported.ObjectivesTo determine the prevalence of Staphylococcus aureus (SA) CC398, both MRSA and MSSA, among blood cultures SA isolates recovered in Spanish hospitals located in regions with different pig-farming densities (PD) and characterize the recovered isolates.MethodsOne thousand twenty-two SA isolates (761 MSSA, 261 MRSA) recovered from blood cultures during 6–12 months in 17 Spanish hospitals (2018–2019) were studied. CC398 lineage identification, detection of spa-types, and antibiotic resistance, virulence and human immune evasion cluster (IEC) genes were analyzed by PCR/sequencing.ResultsForty-four CC398-MSSA isolates (4.3% of SA; 5.8% of MSSA) and 10 CC398-MRSA isolates (1% of SA; 3.8% of MRSA) were detected. Eleven spa-types were found among the CC398-MSSA isolates with t571 and t1451 the most frequent spa-types detected (75%). Most of CC398-MSSA isolates were Immune-Evasion-Cluster (IEC)-positive (88.6%), tetracycline-susceptible (95.5%) and erythromycin/clindamycin–inducible-resistant/erm(T)-positive (75%). No statistical significance was detected when the CC398-MSSA/MSSA rate was correlated to PD (pigs/km2) (p = 0.108). On the contrary, CC398-MRSA isolates were all IEC-negative, predominately spa-t011 (70%), and the CC398-MRSA/MRSA rate was significantly associated to PD (p < 0.005).ConclusionCC398-MSSA is an emerging clade in invasive infections in Spanish hospitals. CC398-MRSA (mostly t011) and CC398-MSSA (mostly t571 and t1451) show important differences, possibly suggesting divergent steps in host-adaptation evolutionary processes. While CC398-MRSA is livestock-associated (lacking IEC-system), CC398-MSSA seems to be mostly livestock-independent, carrying human-adaptation markers.

Molecular Study of Immune Evasion Cluster Genes in Clinical Isolates of Staphylococcus aureus

2021 ◽  
Vol 10 ◽  
Author(s):  
Maysaa El Sayed Zaki ◽  
Samah Sabry El-Kazzaz
Keyword(s):  
Staphylococcus Aureus ◽  
Immune Evasion ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Beta Lactam ◽  
Sensitivity Testing ◽  
Cross Sectional ◽  
Methicillin Resistant ◽  
Beta Lactam Antibiotics ◽  
Immune Evasion Cluster

Aims: The aim of the present research was to highlight the prevalence of immune evasion cluster genes (IEC) sak, chp, scn, sea, sep among Staphylococcus aureus (S. aureus) clinical isolates. Background: The present study was a cross-sectional retrospective study, included one hundred isolates of S. aureus that were isolated from patients with nosocomial infections. S. aureus isolates were subjected to full microbiological identification and antibiotics sensitivity testing by the disc diffusion method. The presence of IEC genes scn, sea, sak, sep, chp was determined by polymerase chain reaction (PCR). Methods: The current study included 100 S. aureus isolates; 40% were classified as methicillin resistant. The isolates exhibited marked resistance to beta lactams antibiotics, the lowest resistance was to erythromycin, ciprofloxacin and vancomycin. The presence of one or more IEC was determined in 89 isolates. The prevalence of chp, sak, sea, sep and scn was 54%, 53%, 8%, 7% and 30%, respectively. Results: S. aureus isolates with IEC genes had increased resistance rates to the studied antibiotics; however, this increase was statistically insignificant either to beta-lactam antibiotics, such as amoxacillin/clavulinic acid (P=0.794), ampicillin (P=0.561), cefotaxim (P=0.271), ceftazidime (P=0.145), imipenem (P=0.589) or non beta-lactam antibiotics, such as amikacin (P=0.955) and trimethoprim/sulfamethoxazale (P=0.974). From 40 methicillin resistant Staphylococcus aureus (MRSA) strains, 37 isolates harbor one or more immune evasion cluster genes. Conclusion: The high prevalence of these genes among MRSA may explain its pathogenesis. There is a need for studies with a high number of isolates to verify the present findings.

scholarly journals Methicillin-Resistant Staphylococcus aureus from Peninsular Malaysian Animal Handlers: Molecular Profile, Antimicrobial Resistance, Immune Evasion Cluster and Genotypic Categorization

Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 103
Author(s):  
Minhian Chai ◽  
Muhammad Zikree Sukiman ◽  
Amirah Huda Kamarun Baharin ◽  
Insyirah Ramlan ◽  
Lennard Zhunhoong Lai ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Immune Evasion ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Peninsular Malaysia ◽  
Molecular Techniques ◽  
Molecular Profile ◽  
Methicillin Resistant ◽  
Immune Evasion Cluster ◽  
Animal Handlers

Staphylococcus aureus (S. aureus) infections, particularly methicillin-resistant Staphylococcus aureus (MRSA) in humans and animals, have become a significant concern globally. The present study aimed to determine the prevalence and antibiogram of S. aureus isolated from animal handlers in Peninsular Malaysia. Furthermore, the genotypic characteristics of S. aureus isolates were also investigated. Nasal and oral swab samples were collected from 423 animal handlers in Peninsular Malaysia. The antibiogram profiles of S. aureus against 18 antibiotics were established using a Kirby–Bauer test. The genotypic profile of S. aureus, including the presence of antimicrobial resistance (AMR), virulence genes and spa genotypes, was investigated using molecular techniques. The overall carriage rate of S. aureus, MRSA and MDRSA was 30.5%, 1.2% and 19.4%, respectively. S. aureus was highly resistant against penicillin (72.3%) and amoxicillin (52.3%). Meanwhile, gentamicin and linezolid were fully effective against all the isolated S. aureus from animal handlers. It was observed that animal handlers with close exposure to poultry were more likely to carry S. aureus that is resistant to tetracycline and erythromycin. S. aureus isolates harboured tetracycline resistance (tetK, tetL and tetM), erythromycin resistance (ermA, ermB, ermC and msrA) and immune evasion cluster (IEC) genes (scn, chp, sak, sea and sep). Seventeen different spa types were detected among the 30 isolates of MDRSA, with t189 (16.7%) and t4171 (16.7%) being the predominant spa type, suggesting wide genetic diversity of the MDRSA isolates. The present study demonstrated the prevalence of S. aureus strains, including MRSA and MDRSA with various antimicrobial resistance and genetic profiles from animal handlers in Peninsular Malaysia.

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