scholarly journals Biofilm Formation and Multiplex PCR detection of icaABCD Operon in Staphylococcus capitis

2021 ◽  
pp. 223-234
Author(s):  
Aziyah Abdul-Aziz ◽  
Mohamad Faiz Foong Abdullah ◽  
Sharifah Aminah Syed Mohamad
Keyword(s):  
Multiplex Pcr ◽  
Dna Sequences ◽  
Biofilm Formation ◽  
Opportunistic Infections ◽  
Opportunistic Pathogen ◽  
Clinical Isolates ◽  
Clinical Samples ◽  
Coagulase Negative Staphylococcus ◽  
Microtitre Plate ◽  
Staphylococcus Capitis

Aims: The ability to form biofilm is a major virulence factor in the virulence of the Coagulase negative Staphylococcus (CoNS) group of bacteria. Being the most predominant member of CoNS, the ability of S. epidermidis in causing biofilm-associated infections has been well established. On the other hand, S. capitis and has always been regard as a non-pathogenic species although recently it was found to be responsible in a variety of infections. Hence, this study aimed to determine the biofilm formation capabilities and the presence of icaABCD genes in clinical isolates of S. capitis, which have emerged as an important opportunistic pathogen in clinical settings. Methodology: S. capitis was isolated and identified from 17 out of 200 clinical samples. Biofilm formation assay was performed quantitatively using a microtitre plate method. Mulitplex PCR primers for icaABCD genes were designed from DNA sequences coding for the icaA, B, C, and D structural genes of S capitis JF930147.1 which was compared together with five other species of Staphylococcus. Amplification of the icaABCD genes was performed using the designated primers. Results: From the 17 strains of S. capitis clinical isolates, 14 were identified as S. capitis subsp capitis while the remaining three were identified as S. capitis subsp ureolyticus. Except for two of the S. capitis subsp capitis isolates, the remaining strains were able to form biofilm, with majority of them were strong biofilm formers. Multiplex PCR was successful in amplifying the four icaABCD genes which was demonstrated in all the S. capitis isolates, including the two non-biofilm forming isolates. Conclusion: Majority of the S. capitis isolates were able to form biofilm phenotypically suggesting the possibility in causing opportunistic infections through indwelling medical devices. Multiplex PCR however was able to detect the presence of the icaABCD genes in all the S. capitis isolates. This suggests that the biofilm assessment on microtitre plate is not a definitive tool in determining the production of polysaccharide intercellular adhesion (PIA) but the production of the icaABCD genes could be a better assessment in determining biofilm production in Staphylococcus.

scholarly journals Molecular Investigation of Fibronectin-Binding Protein Genes and Capacity of Biofilm Production in Staphylococcus Aureus Isolated From Clinical Samples

2021 ◽  
Author(s):  
Hossein Jafari Soghondicolaei ◽  
Mohammad Ahanjan ◽  
Mehrdad Gholami ◽  
Bahman Mirzaei ◽  
Hamid Reza Goli
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Colorimetric Assay ◽  
Binding Protein ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Biofilm Production ◽  
Fibronectin Binding Protein ◽  
Fibronectin Binding

Abstract Biofilm production increases Staphylococcus aureus resistance to antibiotics and also host defense mechanisms. The current study aims to evaluate the biofilm formation by S. aureus and to determine the prevalence of fibronectin-binding protein genes, also its correlation with drug resistance. In this study, 100 clinical isolates of S. aureus were collected. The antibiotic susceptibility pattern of the isolates was evaluated by the disk agar diffusion method. The ability of biofilm formation in the studied isolates was also determined by microplate colorimetric assay. Then, all isolates were screened by polymerase chain reaction for the fnbA and fnbB genes. Out of 100 clinical isolates of S. aureus, the highest and lowest antibiotic resistance rates were against penicillin (94%) and vancomycin (6%). Thirty-two cases were found to be multi-drug resistant (MDR) among the all strains. The ability of biofilm production was observed in 89% of the isolates. The PCR results showed that the prevalence of fnbA and fnbB genes were 91% and 17%, respectively. Moreover, 100% and 21.8% of the MDR strains harbored the fnbA and fnbB genes respectively. The ability to form biofilm in MDR isolates of S. aureus is more than non-MDR isolates, especially fnbA positive ones. As the bacteria in the biofilm are difficult to kill by antibiotics, attention to the removal or control of the biofilm production seems to be necessary.

scholarly journals Evaluation of Antibiotic Resistance Pattern, Alginate and Biofilm Production in Clinical Isolates of Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Fateme DAVARZANI ◽  
Navid SAIDI ◽  
Saeed BESHARATI ◽  
Horieh SADERI ◽  
Iraj RASOOLI ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Resistance Pattern ◽  
Alginate Production ◽  
Opportunistic Bacteria

Background: Pseudomonas aeruginosa is one of the most common opportunistic bacteria causing nosocomial infections, which has significant resistance to antimicrobial agents. This bacterium is a biofilm and alginate producer. Biofilm increases the bacterial resistance to antibiotics and the immune system. Therefore, the present study was conducted to investigate the biofilm formation, alginate production and antimicrobial resistance patterns in the clinical isolates of P. aeruginosa. Methods: One hundred isolates of P. aeruginosa were collected during the study period (from Dec 2017 to Jul 2018) from different clinical samples of the patients admitted to Milad and Pars Hospitals at Tehran, Iran. Isolates were identified and confirmed by phenotypic and genotypic methods. Antimicrobial susceptibility was specified by the disk diffusion method. Biofilm formation and alginate production were measured by microtiter plate and carbazole assay, respectively. Results: Sixteen isolates were resistant to all the 12 studied antibiotics. Moreover, 31 isolates were MultidrugResistant (MDR). The highest resistance rate was related to ofloxacin (36 isolates) and the least resistance was related to piperacillin-tazobactam (21 isolates). All the isolates could produce the biofilm and alginate. The number of isolates producing strong, medium and weak biofilms was equal to 34, 52, and 14, respectively. Alginate production was more than 400 μg/ml in 39 isolates, 250-400 μg/ml in 51 isolates and less than 250 μg/ml in 10 isolates. Conclusion: High prevalence of MDR, biofilm formation, and alginate production were observed among the clinical isolates of P. aeruginosa. The results also showed a significant relationship between the amount of alginate production and the level of biofilm formation.

scholarly journals Correlation of biofilm formation and antibiotic resistance among clinical and soil isolates of Acinetobacter baumannii in Iraq

2019 ◽  
pp. 1-10 ◽  
Author(s):  
Pakhshan A. Hassan ◽  
Adel K. Khider
Keyword(s):  
Acinetobacter Baumannii ◽  
Congo Red ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Microtiter Plate ◽  
Test Tube ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Disk Diffusion Method

Acinetobacter baumannii is an opportunistic pathogen that is reported as a major cause of nosocomial infections. The aim of this study was to investigate the biofilm formation by A. baumannii clinical and soil isolates, to display their susceptibility to 11 antibiotics and to study a possible relationship between formation of biofilm and multidrug resistance. During 8 months period, from June 2016 to January 2017, a total of 52 clinical and 22 soil isolates of A. baumannii were collected and identified through conventional phenotypic, chromo agar, biochemical tests, API 20E system, and confirmed genotypically by PCR for blaOXA-51-like gene. Antibiotic susceptibility of isolates was determined by standard disk diffusion method according to Clinical and Laboratory Standard Institute. The biofilm formation was studied using Congo red agar, test tube, and microtiter plate methods. The clinical isolates were 100% resistance to ciprofloxacin, ceftazidime, piperacillin, 96.15% to gentamicin, 96.15% to imipenem, 92.31% to meropenem, and 78.85% to amikacin. The soil A. baumannii isolates were 100% sensitive to imipenem, meropenem, and gentamicin, and 90.1% to ciprofloxacin. All A. baumannii isolates (clinical and soil) were susceptible to polymyxin B. The percentage of biofilm formation in Congo red agar, test tube, and microtiter plate assays was 10.81%, 63.51%, and 86.48%, respectively. More robust biofilm former population was mainly among non-MDR isolates. Isolates with a higher level of resistance tended to form weaker biofilms. The soil isolates exhibited less resistance to antibiotics than clinical isolates. However, the soil isolates produce stronger biofilms than clinical isolates.

Development of multiplex PCR for rapid detection of metallo-β-lactamase genes in clinical isolates of Acinetobacter baumannii

2020 ◽  
Author(s):  
Reza Ranjbar ◽  
Shahin Zayeri ◽  
Amir Mirzaie
Keyword(s):  
Acinetobacter Baumannii ◽  
Multiplex Pcr ◽  
Rapid Detection ◽  
Simultaneous Detection ◽  
Cross Reactivity ◽  
Clinical Isolates ◽  
Clinical Samples ◽  
Pcr Assay ◽  
Multiplex Pcr Assay

Background and Objectives: Acinetobacter baumannii has been known as a major pathogen causing nosocomial infec- tions. The aim of this study was to develop multiplex PCR for rapid and simultaneous detection of metallo-β-lactamase (MBL) genes in clinical isolates of A. baumannii. Materials and Methods: In this study, we used three sets of primers to amplify the MBL genes including bla        ,     bla   and bla   OXA-48 . The multiplex PCR assay was optimized for rapid and simultaneous detection of MBL genes in A. bau-   OXA-23   NDM   mannii strains recovered from clinical samples. Results: A. baumannii strains recovered from clinical samples were subjected to the study. The multiplex PCR produced 3   OXA-48   OXA-23   bands of 501 bp for bla        , 744 bp for bla observed in multiplex PCR.   OXA-48   and 623 bp for bla   NDM   genes. In addition to, no any cross-reactivity was   Conclusion: Based on obtained data, the multiplex PCR had a good specificity without any cross reactivity and it appears that the multiplex PCR is reliable assay for simultaneous detection of MBL genes in A. baumannii strains.  

RpoS Mutation Leads to Prolonged Biofilm Mode of Growth and a Higher Fitness in Pseudomonas Aeruginosa Biofilms

2021 ◽  
Author(s):  
Xiangke Duan ◽  
Yanrong Pan ◽  
Zhao Cai ◽  
Yumei Liu ◽  
Yingdan Zhang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Treatment ◽  
Biofilm Formation ◽  
Point Mutations ◽  
Opportunistic Pathogen ◽  
Antimicrobial Treatment ◽  
Clinical Isolates ◽  
High Dose ◽  
Sequencing Analysis ◽  
Cyclic Treatment

Abstract BackgroundPseudomonas aeruginosa is a notorious opportunistic pathogen causing various biofilm-related infections. Biofilm formation is a unique microbial strategy that allows P. aeruginosa to survive adverse conditions such as antibiotic treatment and human immune responses. ResultsIn this study, we experimentally evolved P. aeruginosa PAO1 biofilms for cyclic treatment in the presence of high dose of imipenem, and enriched hyperbiofilm mutants within six cycles in two independent lineages. The competition assay showed the evolved hyperbiofilm mutants can outcompete the ancestral strain within biofilm by prolonging the biofilm mode of growth but not in planktonic cultures. Whole-genome sequencing analysis revealed the hyperbiofilm phenotype is caused by point mutations in rpoS gene in all independently evolved mutants and the same mutation was found in P. aeruginosa clinical isolates. We further showed that mutation in rpoS enhanced biofilm formation by prolonging the biofilm mode of growth and elevating the intracellular c-di-GMP level. Mutation in rpoS increased pyocyanin production and virulence in both P. aeruginosa laboratory strains and clinical isolates. ConclusionHere, our study revealed that antibiotic treatment of biofilm-related P. aeruginosa infections might induce a hyperbiofilm phenotype via rpoS mutation, which might partially explain antimicrobial treatment failure of many P. aeruginosa biofilm-related infections.

scholarly journals Thiostrepton Hijacks Pyoverdine Receptors To Inhibit Growth ofPseudomonas aeruginosa

2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Michael R. M. Ranieri ◽  
Derek C. K. Chan ◽  
Luke N. Yaeger ◽  
Madeleine Rudolph ◽  
Sawyer Karabelas-Pittman ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
23S Rrna ◽  
Dependent Manner ◽  
Peptide Antibiotics ◽  
Iron Starvation ◽  
Gram Negative ◽  
Content Type

ABSTRACTPseudomonas aeruginosais a biofilm-forming opportunistic pathogen and is intrinsically resistant to many antibiotics. In a high-throughput screen for molecules that modulate biofilm formation, we discovered that the thiopeptide antibiotic thiostrepton (TS), which is considered to be inactive against Gram-negative bacteria, stimulatedP. aeruginosabiofilm formation in a dose-dependent manner. This phenotype is characteristic of exposure to antimicrobial compounds at subinhibitory concentrations, suggesting that TS was active againstP. aeruginosa. Supporting this observation, TS inhibited the growth of a panel of 96 multidrug-resistant (MDR)P. aeruginosaclinical isolates at low-micromolar concentrations. TS also had activity againstAcinetobacter baumanniiclinical isolates. The expression of Tsr, a 23S rRNA-modifying methyltransferase from TS producerStreptomyces azureus, intransconferred TS resistance, confirming that the drug acted via its canonical mode of action, inhibition of ribosome function. The deletion of oligopeptide permease systems used by other peptide antibiotics for uptake failed to confer TS resistance. TS susceptibility was inversely proportional to iron availability, suggesting that TS exploits uptake pathways whose expression is increased under iron starvation. Consistent with this finding, TS activity againstP. aeruginosaandA. baumanniiwas potentiated by the FDA-approved iron chelators deferiprone and deferasirox and by heat-inactivated serum. Screening ofP. aeruginosamutants for TS resistance revealed that it exploits pyoverdine receptors FpvA and FpvB to cross the outer membrane. We show that the biofilm stimulation phenotype can reveal cryptic subinhibitory antibiotic activity, and that TS has activity against select multidrug-resistant Gram-negative pathogens under iron-limited growth conditions, similar to those encountered at sites of infection.

scholarly journals Association of Biofilm Formation with Antimicrobial Resistance Among the Acinetobacter Species in A Tertiary Care Hospital in Bangladesh

2013 ◽  
Vol 14 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Azizun Nahar ◽  
Shaheda Anwar ◽  
Md. Ruhul Amin Miah
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Tertiary Care ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Clinical Samples ◽  
Care Hospital ◽  
Acinetobacter Species

Purpose: The purpose of this study was to detect biofilm formation in clinical isolates of Acinetobacter species and to observe correlation between biofilm formation and antimicrobial resistance among Acinetobacter isolates. Methods: Two hundred fifty six clinical samples collected from patients who were admitted in Intensive Care Unit (ICU) and on device, patients from Surgery, Medicine, Gynae & Obs and Urology department of Bangabandhu Sheikh Mujib Medical University (BSMMU) and from Burn unit of Dhaka Medical College Hospital were included in this study. Biofilm formation and antibiotyping were performed for the isolates of Acinetobacter species recovered from clinical samples including tracheal aspirates, blood, urine, wound swab, pus, throat swab, endotracheal tubes, burn samples, ascitic fluid, sputum, aural swab, oral swab, cerebrospinal fluid, and catheter tip. Correlation of biofilm formation with antimicrobial resistance pattern among Acinetobacter isolates were also observed in this study. Result: A total of 256 various specimens were studied of which 95 Intensive Care Unit (ICU) and 161 Non ICU samples. Out of 95 ICU and 161 Non ICU samples, Acinetobacter species were isolated from 32 (33.7%) and 20(12.4%) respectively. From 32 ICU and 20 Non ICU Acinetobacter isolates, 28 (87.5%) and 11 (55%) were biofilm producers. Biofilm forming capacity of Acinetobacter species was significantly (p<0.008) greater in ICU than in Non ICU isolates. In both ICU and Non ICU isolates, biofilm forming Acinetobacter species were 100% resistant to amoxicillin, ceftriaxone, ceftazidime, cefotaxime, cefuroxime, and aztreonam. Resistance to antibiotics such as gentamicin, amikacin, netilmicin, ciprofloxacin and imipenem was higher among biofilm forming Acinetobacter isolates in ICU than Non ICU isolates. Susceptibility to colistin was 100% in Non ICU isolates but in ICU it showed 7.1% resistance. Conclusions: This investigation showed that most of the clinical isolates of Acinetobacter species were biofilm producers especially from ICU samples and they were multidrug resistant. Even polymixin resistant Acinetobacter isolates are slowly emerging. This is very alerming for us that biofilm forming multidrug resistant Acinetobacter species represents a severe threat in the treatment of hospitalized patients. So, antibiotic policy and guidelines are essential to eliminate major outbreak in future.DOI: http://dx.doi.org/10.3329/jom.v14i1.14533 J MEDICINE 2013; 14 : 28-32

scholarly journals Identification of Acinetobacter baumannii and detection of ß - lactam antibiotic resistance genes in clinical samples by multiplex PCR

2020 ◽  
Author(s):  
Trinh Phan-Canh ◽  
Thao Le-Thi-Thanh ◽  
Thuy Ngo-Thi-Bich ◽  
Thanh Nguyen-Thi-Thanh ◽  
Linh Ho-Le-Truc ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Multiplex Pcr ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Clinical Isolates ◽  
Clinical Samples ◽  
List Type ◽  
Sensitivity Testing ◽  
Lactam Antibiotic

AbstractAcinetobacter baumannii is the leading cause of hospital-acquired infection in Vietnam. Of note, antibiotic resistance genes are significantly popular in clinical isolates of A. baumannii. Therefore, rapid identification of A. baumannii and determination of antibiotic resistance genes will help to make effective clinical decisions related to antibiotic use. This paper proposes a multiplex PCR to identify Acinetobacter baumannii and detect their ß-lactam antibiotic resistance genes in clinical isolates. Multiplex PCR was applied to amplified recA gene and region ITS 16S - 23S rDNA for Rapid detection of A. baumannii. The two antibiotic resistance genes - blaOXA-51-like, ampC gene - were detected by multiplex PCR and three genes coding Extended-spectrum beta-lactamases - blaCTX-M, blaTEM, blaSHV genes - were subjected to PCR. 49 bacteria strains were subjected to colony PCR. The result showed that 46 strains were A. baumannii and 3 strains belonged to the genus Acinetobacter. The multiplex PCR showed that all of 46 A. baumannii containing the blaOXA-51-like gene and the AmpC gene; 34 strains possess the gene blaTEM and none of them has blaCTX-M and blaSHV genes. The results of the multiplex PCR are the same as those of the in vitro antibiotic sensitivity testing of A. baumannii. However, applying the multiplex PCR directly from the bacteria colony, we can proceed simultaneously with the bacterial identification and the antibiotic resistance gene detection.Highlights100% of isolates of A. baumannii contains the blaOXA-51-like gene and the AmpC gene.34/46 isolates possess the gene blaTEM, however, do not contain blaCTX-M and blaSHV genes.Combined disc test with cefotaxime/clavulanic acid/boronic acid is an excellent method to analyse ESBL phenotype.

scholarly journals Temperature, pH and Trimethoprim-Sulfamethoxazole Are Potent Inhibitors of Biofilm Formation by Stenotrophomonas maltophilia Clinical Isolates

2017 ◽  
Vol 66 (4) ◽  
pp. 433-438 ◽  
Author(s):  
Marjan Biočanin ◽  
Haowa Madi ◽  
Zorica Vasiljević ◽  
Milan Kojić ◽  
Branko Jovčić ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Stenotrophomonas Maltophilia ◽  
Tertiary Care ◽  
Opportunistic Pathogen ◽  
Growth Conditions ◽  
Clinical Isolates ◽  
Multiple Drug ◽  
Dependent Manner ◽  
Virulence Determinants ◽  
Intrinsic Resistance

Stenotrophomonas maltophilia, an opportunistic pathogen usually connected with healthcare-associated infections, is an environmental bacterium. Intrinsic resistance to multiple antibiotics, with different virulence determinants in the last decade classified this bacterium in the group of global multiple drug resistant (MDR) organism. S. maltophilia clinical isolates, were collected from tertiary care pediatric hospital in Belgrade, Serbia to investigate influence of different factors on biofilm formation, kinetics of biofilm formation for strong biofilm producers and effect of trimethoprim-sulfamethoxazole (TMP/SMX) on formed biofilm. Most of the isolates (89.8%) were able to form a biofilm. Analysis of biofilm formation in different growth conditions showed that changing of temeperature and pH had the stronggest effect on biofilm formation almost equally in group of cystic fibrosis (CF) and non-CF strains. TMP/SMX in concentration of 50 μg/ml reduced completely 24 h old biofilms while concentration of 25 μg/ml effects formed biofilms in a strain dependent manner. Among strains able to form strong biofilm CF isolates formed biofilm slower than non-CF isolates, while shaking conditions did not affect biofilm formation. Swimming motility was detected in both CF and non-CF isolates, however more motile strain formed stronger biofilms. This study suggests that temperature, pH and TMP/SMX had the strongest influence on biofilm formation in analyzed collection of S. maltophilia. A positive correlation between motility and strength of formed biofilm was demonstrated.

Sign in / Sign up

Export Citation Format

Share Document