High prevalence of SCC mec-associated Phenol-soluble modulin gene in clinical isolates of methicillin-resistant. Staphylococcus aureus (original) (raw)
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The increasing incidence of methicillin-resistant and biofilm-forming S. aureus isolates in hospital settings is a gruesome concern today. The main objectives of this study were to determine the burden of S. aureus in clinical samples, assess their antibiotic susceptibility pattern and detect biofilm formation and mecA gene in them. A total of 1968 different clinical specimens were processed to isolate S. aureus following standard microbiological procedures. Antibiotic susceptibility test of the isolates was performed by Kirby–Bauer disc-diffusion method following CLSI guidelines. Biofilm was detected through tissue culture plate method. Methicillin-resistant S. aureus (MRSA) isolates were screened using cefoxitin (30 µg) discs and mecA gene was amplified by conventional polymerase chain reaction (PCR). Of 177 bacterial growth, the prevalence of S. aureus was 15.3% (n = 27). MRSA were 55.6% (15/27) and 44% (12/27) exhibited multidrug resistance (MDR). There was no significant associ...
BMC Research Notes, 2020
ObjectiveThis 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.ResultThis 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.
PLOS ONE, 2024
Biofilm development significantly enhances the virulence of methicillin-resistant Staphylococcus aureus (MRSA), leading to severe infections and decreased susceptibility to antibiotics, especially in strains associated with hospital environments. This study examined the occurrence of MRSA, their ability to form biofilms, agr typing, and the antibiotic resistance profiles of biofilm-forming MRSA strains isolated from environmental surfaces at Mymensingh Medical College Hospital (MMCH). From 120 swab samples, 86 (71.67%) tested positive for S. aureus. MRSA was identified in 86 isolates using the disk diffusion technique, and by polymerase chain reaction (PCR), 56 (65.1%) isolates were confirmed to carry the mecA gene. The Crystal Violet Microtiter Plate (CVMP) test revealed that 80.35% (45 isolates) were biofilm-forming and 19.6% (11 isolates) were non-biofilm-forming. Out of 45 biofilm producer isolates 37.5% and 42.9% isolates exhibited strong and intermediate biofilm-forming characteristics, respectively. Molecular analysis revealed that 17.78% of MRSA isolates carried at least one gene related to biofilm formation, specifically icaA, icaB, and icaD genes were discovered in 13.33%, 8.89%, 6.67% of the MRSA isolates, respectively. In agr typing, the most prevalent group was agr I (71.11%), followed by group III (17.78%) and group II (11.11%). Group IV was not detected. The distribution of agr gene groups showed a significant difference among biofilm-forming isolates (p < 0.05). In agr group I, 18.75% of isolates carried the icaA gene, 12.5% carried the icaB gene, and 9.37% carried the icaD gene. Biofilm-forming genes were not detected in any of the isolates from agr groups II or III. There are no statistically significant differences between agr groups and the presence of these genes (p > 0.05). Antibiotic resistance varied significantly among agr groups, with agr group I displaying the highest resistance, agr group II, and agr group III exhibiting the least resistance (p < 0.05). Seventy-three (73.3%) of the isolates were multi-drug resistant, with agr group I displaying nineteen MDR patterns. The occurrence of MRSA in hospital environments and their capacity to form biofilm raises concerns for public health. These findings support the importance of further research focused on agr quorum sensing systems as a basis for developing novel antibacterial agents.
Comparative analysis of biofilm development among MRSA and MSSA strains
Roumanian archives of microbiology and immunology
As the recalcitrance of biofilm-mediated infections to the anti-infective treatment has an adverse effect on patient's health, the main objective of this study was to investigate the capacity of clinical isolates of Staphylococcus aureus with different resistance patterns to form biofilms. S. aureus strains are among the most representative etiology of infections in the health-care environment of Milad hospital in Iran. The results showed that out of 80 analyzed strains, 27 methicillin resistant S. aureus (MRSA) and 29 methicillin susceptible S. aureus (MSSA) were positive for biofilm development ability, without any significant correlation observed between MRSA and biofilm production.
Biofilm Formation and Methicillin Resistance of Staphylococcus aureus Isolated from Clinical Samples
The International Arabic Journal of Antimicrobial Agents, 2020
Background: Staphylococcus aureus including methicillin resistant S. aureus (MRSA) is one of the most effective biofilm-forming organisms, biofilm contribute in protecting the microorganism from host defenses and prevent the effective penetration of antimicrobial agents. Biofilm formation is considered as an important contributing factor for the initiation and establishment of chronic infection by S. aureus and known as a major obstacle in the treatment of S. aureus infections is their ability to develop resistance to antimicrobials. Aims : To screen clinical Staphylococcus aureus including MRSA isolates for their biofilm forming abilities and their association with antimicrobial resistance. Methods: A total of 196 clinical isolates of S. aureus were obtained from different sample sources using standard microbiological techniques from three major hospitals in Gaza strip. Biofilm formation of these isolates was determined by tissue culture plate (TCP) method and tube adherence method...
BMC Infectious Diseases, 2018
Background: Methicillin resistant Staphylococcus aureus (MRSA) is recognized worldwide as a leading cause of hospital and community infections. Biofilm formation by MRSA is an extremely important virulence factor to be understood. Our aim was to establish phenotypic and genotypic characterization of virulence factors among 43 MRSA clinical isolates in a Tunisian hospital. Methods: We investigated enzymatic profiles, biofilm production and prevalences of genes encoding intracellular adhesion molecules (icaA and icaD), Microbial Surface Components Recognizing Adhesive Matrix Molecules genes (fnbA, fnbB and cna) and exoenzymes genes (geh, sspA and sspB). Results: Our findings revealed that caseinase, gelatinase, lipase and lecithinase activities were detected in 100%, 100%, 76.6% and 93.3% of cases respectively. This study showed that 23 strains (76.7%) were slime producers on Congo red medium. Furthermore, 46.5% and 53.5% of isolates were respectively highly and moderately biofilm-forming on polystyrene. Significant association was found between both biofilm tests. PCR detection showed that 74.4%, 18.6%, 69.8%, 65.1% and 74.4% of isolates harbored fnbA, fnbB, icaA, icaD and cna genes respectively. In addition, 34.9%, 18.6% and 30.2% of MRSA strains were found positive for sspA, sspB and geh genes respectively. Further, statistical data showed that the presence of the fnbA and fnbB genes was significantly associated with a high biofilm production on polystyrene. However, no statistical association was observed for the icaA, icaD and cna genes. Conclusions: This study indicates that the detection of fnbA and fnbB contributing to the first step of biofilm formation has been predictable of high biofilm production. As studied factors contribute to MRSA virulence, this research could be of value in orienting towards the development of new preventive and therapeutic measures.
The Open Infectious Diseases Journal, 2018
Background: The multidrug resistance of Methicillin Resistant Staphylococcus aureus (MRSA) has become increasingly a major problem and responsible for most of the hospital acquired infections seen in local hospitals in Egypt. This emphasizes the importance of rapid detection of MRSA and investigating their virulence determinants that may be used as a target for certain anti-infectious agents that could help in the control measures in our hospitals. The aim of this study was to investigate some virulence determinants in MRSA isolates. Materials and findings: A total number of 164 bacterial isolates were recovered from different clinical specimens obtained from Ain Shams University Hospital patients (El Demerdash). Of these, 99 isolates (60.4 %) were recovered from pus, 35 isolates (21.3 %) from sputum, 18 (11 %) isolates from nasal swabs, 11 (6.7 %) isolates from blood and one isolate (0.6 %) was recovered from prostatic exudates. A total of 59 isolates were identified as S. aureus using microscopical examination, culture characteristics and biochemical reactions. Screening for methicillin resistance was done by agar disc diffusion method using cefoxitin discs. Out of the 59 S. aureus isolates, 48 ones were MRSA. Thereafter, all MRSA isolates were investigated for protease, lipase, hemolysin as well as biofilm formation. Results showed that all MRSA isolates possess protease activities while most of them did not show hemolysin or lipase activities. On the other hand, all MRSA isolates showed capability to form biofilm. The statistical analysis showed that there was a significant increase in mean biofilm formation among highly resistant isolates compared to those of moderate and low resistant ones (P<0.01).
Duhok Medical Journal, 2012
Background and objectives Methicillin resistant Staphylococcus aureus is a significant cause of life-threatening human infections, which can switch from planktonic forms (i.e. single cells) to biofilms. Biofilm formation was often-lower susceptibility to antibiotic treatments and development of chronic infections. The study was investigated biofilm formation by methicillin resistant Staphylococcus aureus isolated from patients with urinary tract infection. Meanwhile assess the relationship between biofilm formation and antibiotic resistance. Methods Staphylococcus aureus were isolated and identification by standard methods from urinary tract infections at three teaching hospitals in Erbil city. Methicillin resistant Staphylococcus aureus were detected by PBP2a. Heterogeneity of of methicillin resistant Staphylococcus aureus was determined by efficiency of plating method. Minimum inhibitory concentration of antibiotics was determined by agar dilution method. Biofilm forming ability of methicillin resistant Staphylococcus aureus was investigated. Results Methicillin resistant Staphylococcus aureus were resistances to 10.92±3.17 antibiotics. The percentage of biofilm formation by methicillin resistant Staphylococcus aureus was 82%. Strong biofilm formations were resistance to13.40±2.51 antibiotics, which is statistically higher than biofilm negative (Mean±SD = 6.56±1.51). Conclusions Most methicillin resistant Staphylococcus aureus were biofilm forming. Biofilm formation was correlated with multiple antibiotics resistance and to heterogeneous of methicillin resistant Staphylococcus aureus.
Infection and Drug Resistance, 2021
Introduction: Staphylococcus aureus (S. aureus) is an important causative pathogen in human infections. The production of biofilms by bacteria is an important factor, leading to treatment failures. There has been significant interest in assessing the possible relationship between the multidrug-resistant (MDR) status and the biofilm-producer phenotype in bacteria. The aim of our present study was to assess the biofilm-production rates in clinical methicillin-susceptible S. aureus [MSSA] and methicillin-resistant S. aureus [MRSA] isolates from Hungarian hospitals and the correlation between resistance characteristics and their biofilm-forming capacity. Methods: A total of three hundred (n=300) S. aureus isolates (corresponding to MSSA and MRSA isolates in equal measure) were included in this study. Identification of the isolates was carried out using the VITEK 2 ID/AST system and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method and E-tests, confirmation of MRSA status was carried out using PBP2a agglutination assay. Biofilm-production was assessed using the crystal violet (CV) tube-adherence method and the Congo red agar (CRA) plate method. Results: There were significant differences among MSSA and MRSA isolates regarding susceptibility-levels to commonly used antibiotics (in case of erythromycin, clindamycin and ciprofloxacin: p<0.001, gentamicin: p=0.023, sulfamethoxazole/trimethoprim: p=0.027, rifampin: p=0.037). In the CV tube adherence-assay, 37% (n=56) of MSSA and 39% (n=58) of MRSA isolates were positive for biofilm-production, while during the use of CRA plates, 41% (n=61) of MSSA and 44% (n=66) of MRSA were positive; no associations were found between methicillin-resistance and biofilm-production. On the other hand, erythromycin, clindamycin and rifampin resistance was associated with biofilm-positivity (p=0.004, p<0.001 and p<0.001, respectively). Biofilm-positive isolates were most common from catheter-associated infections. Discussion: Our study emphasizes the need for additional experiments to assess the role biofilms have in the pathogenesis of implant-associated and chronic S. aureus infections.
Prevalence of MRSA and Biofilm Associated Gene among Clinical Isolates of Staphylococci
International Journal of Current Microbiology and Applied Sciences, 2018
Antibiotic resistance and biofilm-forming capacity of the Staphylococcus spp contribute as a major pathogen in both healthcare and community settings. Biofilms are defined as communities of bacteria encased in a self-synthesized extracellular polymeric matrix that attaches to a biotic or abiotic surface. Biofilm-forming staphylococci including S. aureus and S. epidermidis, have been one of the major cause of chronic polymer-associated infection. Infections involving biofilmforming bacteria are extremely difficult to