scholarly journals Antimicrobial Resistance and Biofilm Formation by Staphylococcus aureus Isolated From Ocular Infections

2020 ◽  
Vol 41 (S1) ◽  
pp. s121-s122
Author(s):  
Marta KŁOS ◽  
Monika Pomorska-Wesołowska ◽  
Dorota Romaniszyn ◽  
Agnieszka Chmielarczyk ◽  
Jadwiga Wojkowska-Mach

Background: Untreated staphylococcal ocular infections may cause injuries in the ocular structure and lead to visual impairments, lesions in the anatomical ocular surface, and blindness. The aim of the study was to describe the characteristic of 90 Staphylococcus aureus (SA) strains from hospital and community treated ocular infections with a special emphasis on ability of biofilm formation and drug resistance. The biofilm formation was carried out using the Congo red agar (CRA) method applying Congo red dye. Studies have demonstrated that the CRA method is simple, fast, and repeatable and that modifications of some components can easily increase its accuracy. Methods: Biofilm formation was examined by the method with CRA test. On CRA, slime-producing strains formed black colonies, whereas nonproducing strains developed red colonies in 6 kinds of colors, from very red to very black: very red, red, burgundy, almost black, black, and very black. Antimicrobial susceptibility testing was performed by disc diffusion or the E-test method according to the current guidelines of the EUCAST. The MRSA, and MLSB phenotypes were detected. Polymerase chain reaction (PCR) was used to detect the mecA, and mupA genes. Erythromycin resistance genes (ermA, ermB, ermC, and msr) were detected by multiplex PCR. Results: A positive result of the CRA test was accomplished in 66.2% cases; significantly more often in hospital strains (73.4% vs 45.4%; OR, 3.3; 55% CI, 1.2–9.3). Moreover, 73.4% isolates were fully susceptible. In hospitalized patients, the level of resistance to at least 1 antimicrobial category has been identified as 40.9%, and this rate was 27.2% in outpatients. Among the tested strains, 5 (6.0%) had the resistance phenotype MRSA and 22 (26.5%) the resistance phenotype MLSB; 4 strains manifested both mechanisms; erythromycin resistance was 25.3% in those resistant to fluoroquinolones. Resistance to fluoroquinolones was 5 times more often found in ambulatory patients. All of the tested isolates were vancomycin sensitive. Conclusions: Biofilm formation is an important risk factor for developmental staphylococcal hospital-acquired ocular infections. Our results prove that hospital strains have demonstrated much greater biofilm-forming ability than nonhospital strains. Studies indicate the high efficacy of chloramphenicol and fluoroquinolones treatments, as well as the need to implement new solutions due to the aforementioned bacteria’s high resistance to neomycin and anatomic barriers difficulties.Disclosures: NoneFunding: None

2018 ◽  
Vol 12 (12) ◽  
pp. 1062-1066 ◽  
Author(s):  
Alasthimannahalli Gangadhara Triveni ◽  
Mendem Suresh Kumar ◽  
Chavadi Manjunath ◽  
Channappa T Shivannavar ◽  
Subhaschandra M Gaddad

Introduction: Staphylococcal biofilms are prominent cause for acute and chronic infection both in hospital and community settings across the world. Current study explores biofilm formation by Staphylococcus aureus isolates from clinical samples by different methods. Methodology: Standard techniques used for the characterization of S.aureus. Qualitative and quantitative biofilm formation was assessed by Congo red Agar, Tube and Microtiter plate methods. Results: A total of 188 clinical isolates of S.aureus were screened for biofilm formation and 72 (38.29%) of them were found to be biofilm producers, 34 (18.08%) strong, 38 (20.21%) moderate. The remaining 116 (61.7%) were weak/ non biofilm producers. Maximum biofilm formers were recorded in pus samples (39.06%), followed by isolates from blood (38.23%) and urine (34.61%). Statistical analysis for the formation of biofilm indicated that Microtiter plate method is the most sensitive and specific method for screening biofilm production. Conclusions: Biofilm formation is one of the influential virulence factor in staphylococcal pathogenesis and persistence. Microtiter plate and Congo red agar remain as reliable methods for the qualitative and quantitative estimation of biofilm formation. Monitoring of biofilm formation in various etiological agents will help in determining the severity of infection.


2021 ◽  
Vol 9 (12) ◽  
pp. 2610
Author(s):  
Carolin J. Schiffer ◽  
Miriam Abele ◽  
Matthias A. Ehrmann ◽  
Rudi F. Vogel

The biofilm associated protein (Bap) is recognised as the essential component for biofilm formation in Staphylococcus aureus V329 and has been predicted as important for other species as well. Although Bap orthologs are also present in most S. xylosus strains, their contribution to biofilm formation has not yet been demonstrated. In this study, different experimental approaches were used to elucidate the effect of Bap on biofilm formation in S. xylosus and the motif structure of two biofilm-forming S. xylosus strains TMW 2.1023 and TMW 2.1523 was compared to Bap of S. aureus V329. We found that despite an identical structural arrangement into four regions, Bap from S. xylosus differs in key factors to Bap of S. aureus, i.e., isoelectric point of aggregation prone Region B, protein homology and type of repeats. Disruption of bap had no effect on aggregation behavior of selected S. xylosus strains and biofilm formation was unaffected (TMW 2.1023) or at best slightly reduced under neutral conditions (TMW 2.1523). Further, we could not observe any typical characteristics of a S. aureus Bap-positive phenotype such as functional impairment by calcium addition and rough colony morphology on congo red agar (CRA). A dominating role of Bap in cell aggregation and biofilm formation as reported mainly for S. aureus V329 was not observed. In contrast, this work demonstrates that functions of S. aureus Bap cannot easily be extrapolated to S. xylosus Bap, which appears as non-essential for biofilm formation in this species. We therefore suggest that biofilm formation in S. xylosus follows different and multifactorial mechanisms.


2020 ◽  
Author(s):  
Juliana Afonso de Almeida ◽  
Caroline Espíndola de Barros ◽  
Gustavo Henrique da Silva Ayres ◽  
Mariana Helena e Silva ◽  
Andressa Santos Liberal ◽  
...  

Abstract Background The tracheostomized patients exhibit high risks of bacterial infections, because the tracheal tube acts as a gateway to these microorganisms. The objective was to characterize microbiologically the tracheal secretion of tracheostomized children, to evaluate the biofilm formation, and to study the phenotypic and molecular profile of antimicrobial resistance of Staphylococcus aureus and Pseudomonas aeruginosa isolated. Methods The study collected 88 tracheal secretion samples. The material processed by phenotypic tests were performed for bacterial identification. For identification of the biofilm, the Congo red agar test and the plaque microtiter test were used, and the qPCR method was used to resistance verification. Results Were obtained 27 samples of S. aureus and 71 of P. aeruginosa . All S. aureus samples were positive for biofilm formation on Congo red agar test. In antibiogram test, S. aureus showed resistance to seven drugs. Regarding the identification of resistance genes, were amplificated bla Z in 42.8% from S. aureus and mec A in 28.6% of them. Pseudomonas aeruginosa presented resistance to eight drugs. The most frequent chromosomal genes were bla OXA with 66.7% and bla KPC with 58.3%. To plasmidial DNA, was highlighted bla NDM with 58.3% positive. Conclusion The S. aureus and P. aeruginosa characterization of colonization from lower respiratory tract associated with the use of the device in tracheotomy patients, and the physiology and antimicrobial resistance profile, will help health professionals to choose the most appropriate treatment to be administered in children with tracheotomy, increasing the chances of airway restoration and decannulation.


Author(s):  
Kamuran Şanlı ◽  
Selen Zeliha Mart Kömürcü ◽  
Nilgün Kansak ◽  
Rıza Adaleti

Objective: The aim of this retrospective study was to evaluate the rate and antimicrobial resistance profile of community-acquired (CA) and hospital-acquired (HA) methicillin-resistant and sensitive Staphylococcus aureus (MRSA, MSSA) strains between 2004 and 2019. Method: Within the scope of the research, the rate of MRSA and MSSA and the change in antimicrobial resistance profile over time were investigated using two research data of 210 Staphylococcus aureus strains isolated in 2004, and 401 in 2019. Results: While any significant change was not seen in the rates of CA-MRSA (32.4%) and CA-MSSA (67.6%) in 2004, and of CA-MRSA (31.6%) and CA-MSSA (68.4%) in 2019, the prevalence of HA-MRSA decreased by 56.1% in 2004 and 30.7% in 2019 and of HA-MSSA increased by 43.9% in 2004 and 69.3% in 2019. No resistance to vancomycin and teikoplanin was observed in MRSA strains. Resistance of CA-MRSA against ciprofloxacin, levofloxacin, clindamycin and gentamicin decreased. In CA-MSSA an increase of penicillin resistance as well as a decrease in gentamicin resistance was observed. In resistance of HA-MRSA against ciprofloxacin, levofloxacin, erythromycin, clindamycin, gentamicin decreased. HA-Resistance of MSSA against fusidic acid increased and against ciprofloxacin and trimethoprim/sulfamethoxazole and erythromycin resistance decreased. Conclusion: It was found that the rate of HA-MRSA decreased during the given period of 15 years. Vancomycin or teicoplanin resistance was not observed in MRSA and MSSA. While against ciprofloxacin, levofloxacin, clindamycin, gentamicin decreased in both CA-MRSA and HA-MRSA. A closer follow-up of the prevalence and antimicrobial resistance profiles of these strains is of utmost importance for the successful control of the infections caused by MRSA and MSSA.


2021 ◽  
Author(s):  
Kiran Fatima ◽  
Kashif Ali

Background: The study was conducted to identify the role of biofilms in the antibiotic susceptibility in the strains of Staphylococcus aureus. A total of 19 non repeated pus/wound swab samples from different anatomic locations and 17 samples that were previously identified as S. aureus and preserved in the labs were included in the study. The Staphylococcus aureus was identified on the basis of colony morphology, Gram's stain, biochemical tests (catalase and coagulase tests) and molecular identification through PCR amplification. Methodology: A total of 26 samples were recovered out of the 31 samples. Kirby-Bauer disk diffusion susceptibility test was used to determine the sensitivity or resistance of S. aureus to methicillin. Out of the 26 strains, 4 were highly resistant, 10 were moderately resistant and 12 strains were sensitive. Three different protocols (Tube Method, Congo Red Agar Method and Tissue Culture plate method) were used for the detection of biofilm formation for both resistant and sensitive strains. Result: Comparative analysis of the antibiotic susceptibility and biofilm formation by different protocols showed that 70% strains that are resistant to antibiotic methicillin produced moderate-strong biofilms. 50% have produced the moderate-strong biofilms in all 3 protocols. In case of sensitive, 50% strains had produced none-weak biofilms in all 3 protocols. Decisions: The strains that had zone of inhibition of close to resistance produced weak-strong biofilms but they all produced weak biofilms in CRA method. It can be concluded that the strains of S. aureus that have the ability to produce biofilms become methicillin resistant. Keywords: Biofilm, antibiotic susceptibility, Congo Red Agar, Tube Method, Tissue culture plats.


2021 ◽  
Vol 22 (2) ◽  
pp. 164-169
Author(s):  
C.I. Orjih ◽  
A. Ajayi ◽  
F.O. Alao ◽  
A.I. Adeleye ◽  
S.I. Smith

Background: Biofilm formation by pathogens is of great clinical importance as it mediates persistence and resistance to antibiotics, hence posing difficulty in treatment and management of diseases. The aim of this study was to evaluate the biofilm forming potential of Staphylococcus aureus isolated from urine samples of females with urinary tract infection and to detect the presence of clumping factor (clfA) and intracellular adhesion (icaA) encoding genes.Methodology: A total of 50 S. aureus were obtained from urine samples of women in five hospitals in Lagos State, Nigeria. Isolates were confirmed by standard biochemical and novobiocin susceptibility tests. The isolates were screened for biofilm formation using three methods; Congo-red agar (CRA), tube, and tissue culture plate (TCP) methods. Detection of clfA and icaA genes was done by PCR.Results: The Congo red agar method showed that 39 (78%) of the isolates were biofilm producers while 11 (22%) were non-biofilm producers. However, the tube method indicated that 12 (24%) were strong biofilm producers, 26 (52%) were moderate biofilm producers, and 12 (24%) were non-biofilm producers. The standard TCP assay showed that strong biofilm producers (OD > 0.240) were 13 (26%), moderate biofilm producers were 22 (44%), and weak or non-biofilm producers (OD < 0.120) were 15 (30%). The tube method showed a good correlation with the TCP method for strong biofilm production. Ten (20%) isolates possessed clfA gene and 31 (62%)possessed icaA gene.Conclusion: The ability of S. aureus to form biofilm is a key risk factor that can increase morbidity and mortality from infections they cause. Hence, rapid and sensitive phenotypic methods can be used in screening for biofilm formation thereby providing data that can guide therapy and control of the pathogen. Keywords: Staphylococcus aureus, Biofilm, Clumping factor, Intracellular adhesion


2019 ◽  
Author(s):  
Bahman Mirzaei ◽  
Reyhaneh Babaei ◽  
Fatemeh Mohammadi ◽  
Hamid Reza Goli ◽  
Sanaz Amir Gholami ◽  
...  

Abstract Background: Staphylococcus aureus as a causative agent of hospital-acquired infections, has been considered as the primary concern in biomaterial-related infections (BAIs). Following the purification of polysaccharide intercellular adhesion (PIA) as an efficient macromolecule in biofilm formation in the native condition, recombinant S . epidermidis surface exposed rSesC protein, with the most homology to clumping factor A (ClfA) in S. aureus was cloned and expressed in a prokaryotic host as well. Fourier transform infrared spectrometry (FTIR) and Western blotting procedure analyzed purified PIA and protein, respectively. Then, the immune response was evaluated by measuring total IgG titers. Moreover, the capacity of Anti-biofilm forming activity of arisen antibodies to a biofilm forming S. aureus strains was assessed by semi-quantitative micro-plate procedure. Results: Data showed that the total IgGs was boosted in mice immunized sera. By performing inhibition assay, biofilm inhibitory effect of secreted antibodies to test strain was observed. Arisen antibodies against the mixture significantly were more potent than PIA and rSesC, when comparing them in a biofilm inhibition assay. Conclusion: Immunization of mice with mentioned antigens especially a mixture of them, could eliminate the biofilm formation process in S. aureus . Hopefully, this study corresponds the suggestion that, the immunization of mice with PIA and rSesC candidate vaccine could protect against S. aureus infection.


2020 ◽  
Vol EJMM29 (4) ◽  
pp. 93-100
Author(s):  
Wageih S. El. Naghy ◽  
Sarah A. Hamam ◽  
Tamer A. Wasfy ◽  
Sara M. Samy

Background: Biofilms are groups of microorganisms that collect to each other and with different surfaces by adherence mechanisms. These are formed of cells and extracellular matrix manufactured by these cells. There may be a great problem in some situations e.g. on medical implants and resistance against antibiotics. Objective: The objective of this study is to determine biofilm forming power of bacteria isolated from the conjunctiva, contact lens and the lens storage case by both phenotypic and genotypic detection methods. Methodology: Samples were taken from (36) persons in the period from January 2020 to June 2020 at Ophthalmology Department, Tanta University Hospitals, all the samples were transported to the Medical Microbiology & Immunology Department, Tanta University where bacterial strains were isolated. The biofilm formation phenotypic detection was performed by both tube method and Congo red agar method. The biofilm-forming genes of coagulase negative Staphylococcus (CoNS) and Staphylococcus aureus (ica A) and that of P. aeruginosa (psl A), were detected by PCR. Results: The (216) samples (swabs & discarded lenses) gave rise to a total number of (247) bacterial isolates. By using tube method; (52.3%) were moderately positive, (31.5%) strongly positive and (16.2%) negative for biofilm formation while after using the Congo red agar method; (35.3%) were moderately positive, (38.4%) strongly positive and (26.3%) negative for biofilm formation. Regarding the Staphylococcus aureus isolates, two (50%) of these were containing (icaA) gene. Regarding the (21) CoNS isolates, three (14.3%) contained (icaA) gene. Although all of the Pseudomonas isolates didn't contain pslA (1119 bp) gene, these were positive for biofilm production by phenotypic methods. Conclusion: The majority of the isolates had the capacity to form biofilms. Both tube and Congo red agar methods showed clear significant correlation and detected a high number of biofilm-producing strains. The absence of genes responsible for biofilm formation did not exclude the phenotypic biofilm production by these bacteria which is a common state.


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