scholarly journals Biofilm formation by bacteria isolated from intensive care units of a tertiary care hospital, with special relevance to its risk factors

Author(s):  
Mayuri Gogoi ◽  
Ajanta Sharma

Background: The purpose of this study was to detect biofilm formation by bacterial isolates from patients with device associated infection admitted in intensive care units (ICUs), to compare the three methods used for detection of bioiflm, to compare the antimicrobial susceptibility pattern of the biofilm producers with the non-producers and to study the risk factors associated with biofilm formation.Methods: A total of 115 bacterial isolates from patients with device associated infection admitted in different ICU for a period of one year was included in the study. These clinical isolates were detected for biofilm formation by tissue culture plate method, tube method and Congo red agar method. Kirby-Bauer disc diffusion method of antibiotic susceptibility was performed on all isolates.Results: Out of the 115 bacterial isolates, 71 were biofilm producers. Tissue culture plate method detected the maximum number of biofilm producers (61.7%). The maximum number of biofilm producers were isolated from tracheal aspirate and endotracheal tubes (52.1%) followed by blood (17%) and urine (12.6%) respectively. The predominant biofilm producing isolates were Klebsiella pneumoniae (39.4%), Staphylococcus aureus (19.7%) and Pseudomonas aeruginosa (16.9%). Multi drug resistance among the biofilm producers was significantly higher than the non-biofilm producers (p value=0.0125). The risk of biofilm formation was seen to increase with the increase in duration of hospital stay (p value=0.0092, statistically very significant).Conclusions: From this study it was found that a high degree of biofilm producers were isolated from patients on indwelling devices. Tissue culture plate was found to be the most accurate method. The degree of multidrug resistance among the bioiflm producers was significantly higher than the non-producers.

2018 ◽  
Vol 33 (3) ◽  
pp. 80-85
Author(s):  
Michael O. Osungunna ◽  
Grace O. Onawunmi

Background: Microorganisms that infect humans differ in pathogenesis, virulence factors and antimicrobial resistance profiles. In natural settings, bacterial cells are most often found in close association with surfaces and interfaces, in the form of multicellular aggregates commonly called biofilms. Given their ubiquity and importance in the microbial world, it is hardly surprising that biofilms have attracted the attention of the scientific community. Biofilm formation on medical implant devices such as catheters is also a major problem that is closely tied to the adhesion and resistance-related abilities of the biofilm.Methodology: The ability of 216 bacterial isolates from mid-stream urine (100), catheter-stream urine (52) and catheter tips (64) to form biofilms was investigated using the tissue culture plate method, the tube and Congo red agar methods as well as their antibiotic resistance profiles using the agar disc diffusion method.Results: These revealed that Klebsiella spp. was the predominant bacterial genera accounting for 45.8% of the total isolates. A total of 50 isolates were biofilm-formers with 22% identified by the tissue culture plate method and 78% identified by the Congo red agar method. Klebsiella spp. had the highest ability to form biofilm while antibiotic resistance profiles showed all the biofilmformers to be multiply antibiotic resistant with least resistance to ofloxacin.Conclusion: It can therefore be concluded that some bacterial isolates associated with urinary tract infections have a propensity to form biofilm, thereby becoming multiply antibiotic resistant, and ofloxacin remains the antibiotic of choice in the treatment of such infections.


Author(s):  
Bedobroto Biswas ◽  
Naik Shalini Ashok ◽  
Deepesh Nagarajan ◽  
Md Zaffar Iqubal

Aims: Identification and grading of the Escherichia coli according to their biofilm production capability. Study Design:  Cross-sectional study. Place and Duration of Study: This was conducted in Department Microbiology at M.S. Ramaiah Medical college and Hospital, Bengaluru from March 2017 to August 2017. Methodology: A total of 55 non repetitive Escherichia coli isolates were identified from various clinical samples like urine, pus ,tissue and peritoneal fluids .All the organisms were isolated in pure culture and biofilm formation was detected in vitro by Gold standard TCP (Tissue culture plate) method. Organisms were incubated for an extended period of 48 hours and the biofilms were detected by acetone alcohol elution method. Organisms were categorized as strong, moderate, weak and no biofilm producers based on the obtained OD value of the elute. Results: Majority of the isolates of Escherichia coli were obtained from catheterized urine culture (67.03%) followed by pus (25.50%).Most of the isolates were capable of forming biofilm in vitro by tissue culture plate method except a few (9.1%). 40% of the isolates were strong biofilm formers which had >4 ODC. 25.5% showed medium biofilm-forming capability and rest 25.5% showed weak biofilm formations in vitro. Conclusion: The ability to form biofilm from a species can give us a better understanding of the biofilm-related infections pertaining to the particular group. Detection of biofilms remains a most important determinant to approximate the incidence of such infections. Categorization of organisms according to their biofilm formation may help us understand the frequency of biofilm-associated infections, and thus take necessary precautions to avoid the problem. Further studies involving the detection of biofilm may be conducted and the tests can be implemented in routine diagnostic microbiology to assess the usefulness of the methods in detection of biofilm-related infections.


2021 ◽  
Vol 13 (4) ◽  
pp. 1043-1052
Author(s):  
Sarita Manandhar ◽  
Raju Shrestha ◽  
Ratna Shova Tuladhar ◽  
Sunil Lekhak

Resistance to antibiotics, biofilm formation and the presence of virulence factors play important roles in increased mortality associated with infection by staphylococci. The macrolide lincosamide streptogramin B (MLSB) family of antibiotics is commonly used to treat infections by methicillin-resistant isolates. Clinical failure of clindamycin therapy has been reported due to multiple mechanisms that confer resistance to MLSB. This study aims to find the incidence of different phenotypes of MLSB resistance and biofilm production among staphylococci. A total of 375 staphylococci were isolated from different clinical samples, received from two tertiary care hospitals in Nepal. Methicillin resistance was detected by cefoxitin disc diffusion method and inducible clindamycin resistance by D test, according to CLSI guidelines. Biofilm formation was detected by the tissue culture plate method and PCR was used to detect ica genes. Of the total staphylococci isolates, 161 (42.9%) were Staphylococcus aureus, with 131 (81.4%) methicillin-resistant strains, and 214 (57.1%) isolates were coagulase-negative staphylococci, with 143 (66.8%) methicillin-resistant strains. The overall prevalence of constitutive MLSB (cMLSB) and inducible MLSB (iMLSB) phenotypes was 77 (20.5%) and 87 (23.2%), respectively. Both iMLSB and cMLSB phenotypes predominated in methicillin-resistant isolates. The tissue culture plate method detected biofilm formation in 174 (46.4%) isolates and ica genes in 86 (22.9%) isolates. Among biofilm producing isolates, cMLSB and iMLSB phenotypes were 35 (20.1%) and 27 (15.5%), respectively. The cMLSB and iMLSB were 11 (12.8%) and 19 (22.1%), respectively, in isolates possessing ica genes. Clindamycin resistance in the form of cMLSB and iMLSB, especially among MRSA, emphasizes the need for routine D tests to be performed in the lab.


2020 ◽  
Vol 56 (2) ◽  
pp. 118
Author(s):  
Wira W Lindarto ◽  
Eddy Bagus Wasito ◽  
Kartuti Debora

This study aimed to analyze the effect of glucose induction on the clinical isolate biofilm density of Acinetobacter baumannii. Thirteen clinical isolates of A. baumannii non biofilm forming were collected from non-DM patients who were treated at the ICU of Dr. Soetomo Hospital, Surabaya, was treated with the addition of 0.08% glucose, 0.15% glucose, 0.2% glucose, and 0.4% glucose in TSB growth media, followed by biofilm density examination with Tissue Culture Plate Method (TCPM) using 96 wells flatbottomed polyesterene tissue culture plate and read by autoreader ELISA with a wavelength of 630 nm (OD630). Biofilm density obtained was analyzed using ANOVA statistical analysis. The results of OD630 showed that the biofilm density increased significantly at the addition of 0.2% and 0.4% glucose. There was a significant increase in biofilm density at the addition of 0.2% and 0.4% glucose so that the management of blood sugar levels in ICU patients was needed before and when medical devices were installed.


Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 630 ◽  
Author(s):  
Aisha M. Alamri ◽  
Afnan A. Alsultan ◽  
Mohammad A. Ansari ◽  
Amani M. Alnimr

This study analyzed the genotype, antibiotic resistance, and biofilm formation of Acinetobacter baumannii strains and assessed the correlation between biofilm formation, antibiotic resistance, and biofilm-related risk factors. A total of 207 non-replicate multi-drug-resistant A. baumannii strains were prospectively isolated. Phenotypic identification and antimicrobial susceptibility testing were carried out. Isolate biofilm formation ability was evaluated using the tissue culture plate (TCP), Congo red agar, and tube methods. Clonal relatedness between the strains was assessed by enterobacterial repetitive intergenic consensus-PCR genotyping. Of the 207 isolates, 52.5% originated from an intensive care unit setting, and pan resistance was observed against ceftazidime and cefepime, with elevated resistance (99–94%) to piperacillin/tazobactam, imipenem, levofloxacin, and ciprofloxacin. alongside high susceptibility to tigecycline (97.8%). The Tissue culture plate, Tube method, and Congo red agar methods revealed that 53.6%, 20.8%, and 2.7% of the strains were strong biofilm producers, respectively, while a significant correlation was observed between biofilm formation and device-originating respiratory isolates (p = 0.0009) and between biofilm formation in colonized vs. true infection isolates (p = 0.0001). No correlation was detected between antibiotic resistance and biofilm formation capacity, and the majority of isolates were clonally unrelated. These findings highlight the urgent need for implementing strict infection control measures in clinical settings.


2018 ◽  
Vol 6 (8) ◽  
pp. 1335-1341 ◽  
Author(s):  
Rania M. Abdel Halim ◽  
Nevine N. Kassem ◽  
Basma S. Mahmoud

AIMS: To evaluate three in vitro phenotypic methods; tissue culture plate, tube method, and Congo red agar for detection of biofilm formation in staphylococci and assess the relation of biofilm formation with methicillin resistance and anti-microbial resistance. METHODS: The study included 150 staphylococcal isolates. Biofilm detection in staphylococci was performed using tissue culture plate, tube method, and Congo red agar. RESULTS: Tissue culture plate, tube method, and Congo red agar detected 74%, 42.7%, and 1.3% biofilm producing staphylococci respectively. S. aureus isolates were more common biofilm producers (53.2%) than CONS (46.8%). Biofilm production in CONS species was highest in S. hemolyticus (57.7%). Tube method was 51.4% sensitive, 82.1% specific. As for Congo red agar, sensitivity was very low (0.9%), but specificity was 97.4%. Biofilm producers were mostly; isolated from blood specimens (82.6%) and detected in methicillin-resistant strains 96/111 (86.5%). They were resistant to most antibiotics except vancomycin and linezolid. CONCLUSIONS: Tissue culture plate is a more quantitative and reliable method for detection of biofilm producing staphylococci compared to tube method and Congo red agar. Hence, it can still be used as a screening method for biofilm detection. Vancomycin and Linezolid are the most sensitive antibiotics among biofilm producing staphylococci.


2018 ◽  
Vol 12 (2) ◽  
pp. 4-9
Author(s):  
Maherun Nesa ◽  
Shaheda Anwar ◽  
Ahmed Abu Saleh

Background: Acinetobacter baumannii is responsible for nosocomial infections which are related to biofilm formation of this pathogen. Biofilm formation helps the bacteria in surviving stressed environmental conditions and bacteria growing in biofilms are resistant to most of the commonly used antibiotics. Objectives: The objective of this study was to detect A. baumannii, to see antibiotic sensitivity and biofilm formation in different clinical samples. Methods: Total 108 Acinetobacter spp. were collected from different clinical samples which were identified by conventional microbiological procedures. Out of 108 Acinetobacter spp, 85 were identified as A. baumannii by polymerase chain reaction by detecting blaOXA-51 gene which is intrinsic to A. baumannii. Antibiotic sensitivity was detected by modified disc diffusion method and biofilm formation was detected by Tissue culture plate method. Results: Among 85 isolates, 45.9% A. baumannii were obtained from tracheal aspirate followed by blood (21.2%), wound swab (15.3%), urine (10.6%), pus (5.9%) and pleural fluid (1.1%). More than 80% 0f A. baumannii was resistant to cephalosporin, aminoglycosides, quinolone, carbapenem. By Tissue culture plate method, 78.8% of isolates showed biofilm formation. Biofilm formation in tracheal aspirate was 82.1%, in blood 72%, in wound swab 92%, in urine 44.4%, in pus 100% and in pleural fluid 100%. Conclusion: Detection rate of A. baumannii was more in tracheal aspirates. Biofilm producing A. Baumannii was resistant to most of the antibiotics. Bangladesh J Med Microbiol 2018; 12 (2): 4-9


2020 ◽  
Vol 8 (4) ◽  
pp. 394-399
Author(s):  
Bijay Kumar Shrestha ◽  
Jenish Shakya

Candida albicans is a member of the healthy human microflora, colonizing several niches in the body and can cause opportunistic infection under host debilitated and immunocompromised condition. The present study aimed to investigate the in-vitro hemolytic activity of C. albicans isolated from oral cavity and screen biofilm through three different methods. During the study, 200 oral rinse samples from general human population were analyzed in microbiology laboratory of Central Campus of Technology, Tribhuvan University, Hattisar, Dharan. Nepal. Candida albicans were isolated and identified by conventional microbiological procedures. The hemolytic activity was evaluated through two different Sabouraud dextrose broth media (SDB) containing 7% defibrinated human blood, one supplemented with 3% glucose (SDBwG) and the other without glucose (SDBwoG). The biofilm formation was screened through congo red agar, tube method and tissue culture plate method. In this present study, 42 (21%) isolates of Candida albicans were isolated from 200 oral rinse samples. Isolated Candida albicans exhibited mean hemolysis activity of 28.66% on human blood SDB without glucose and 43.55% on human blood SDB with 3% glucose. Tissue culture plate method was considered sensitive, specific and accurate method for quantitative screening of biofilm in comparison to tube method and congo red agar method. This research concluded that Candida albicans exhibited greater hemolytic activity in human blood with glucose (SDBwG) than in human blood without glucose (SDBwoG). This finding explains that an increased blood glucose concentration may contribute to increased hemolysis activity of Candida albicans that could play pathogenic role for inducing infection like oral candidiasis in debilitated host like diabetic patients. Tissue culture plate method can accurately screen biofilms than tube and congo red agar method. Int. J. Appl. Sci. Biotechnol. Vol 8(4): 394-399


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