scholarly journals Biofilm-Formation in Clonally Unrelated Multidrug-Resistant Acinetobacter baumannii Isolates

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 630 ◽  
Author(s):  
Aisha M. Alamri ◽  
Afnan A. Alsultan ◽  
Mohammad A. Ansari ◽  
Amani M. Alnimr
Keyword(s):  
Tissue Culture ◽  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Congo Red ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Control Measures ◽  
Infection Control Measures ◽  
Culture Plate ◽  
Tissue Culture Plate

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.

scholarly journals Antibiotic resistance profiles of biofilm-forming bacteria associated with urine and urinary catheters in a tertiary hospital in Ile-Ife, Nigeria

2018 ◽  
Vol 33 (3) ◽  
pp. 80-85
Author(s):  
Michael O. Osungunna ◽  
Grace O. Onawunmi
Keyword(s):  
Tissue Culture ◽  
Antibiotic Resistance ◽  
Congo Red ◽  
Bacterial Isolates ◽  
Plate Method ◽  
Antibiotic Resistant ◽  
Culture Plate ◽  
Tissue Culture Plate ◽  
Tract Infections ◽  
Klebsiella Spp

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.

scholarly journals Detection of Biofilm Producing Staphylococci among Different Clinical Isolates and Its Relation to Methicillin Susceptibility

2018 ◽  
Vol 6 (8) ◽  
pp. 1335-1341 ◽  
Author(s):  
Rania M. Abdel Halim ◽  
Nevine N. Kassem ◽  
Basma S. Mahmoud
Keyword(s):  
Tissue Culture ◽  
Congo Red ◽  
Biofilm Formation ◽  
Methicillin Resistance ◽  
Screening Method ◽  
Culture Plate ◽  
Tissue Culture Plate ◽  
Blood Specimens ◽  
Phenotypic Methods

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.

scholarly journals Correlation between antimicrobial resistance and biofilm formation capability among Klebsiella pneumoniae strains isolated from hospitalized patients in Iran

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Shadi Shadkam ◽  
Hamid Reza Goli ◽  
Bahman Mirzaei ◽  
Mehrdad Gholami ◽  
Mohammad Ahanjan
Keyword(s):  
Tissue Culture ◽  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Hospitalized Patients ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Culture Plate ◽  
Tissue Culture Plate

Abstract Background Klebsiella pneumoniae is a common cause of nosocomial infections. Antibiotic resistance and ability to form biofilm, as two key virulence factors of K. pneumoniae, are involved in the persistence of infections. The purpose of this study was to investigate the correlation between antimicrobial resistance and biofilm formation capability among K. pneumoniae strains isolated from hospitalized patients in Iran. Methods Over a 10-month period, a total of 100 non-duplicate K. pneumoniae strains were collected. Antibiotic susceptibility was determined by Kirby–Bauer disk diffusion method according to CLSI. Biofilm production was assessed by tissue culture plate method. Finally, polymerase chain reaction was conducted to detect four families of carbapenemase: blaIMP, blaVIM, blaNDM, blaOXA−48; biofilm formation associated genes: treC, wza, luxS; and K. pneumoniae confirming gene: rpoB. Results Most of the isolates were resistant to trimethoprim-sulfamethoxazole (52 %), cefotaxime (51 %), cefepime (43 %), and ceftriaxone (43 %). Among all the 100 isolates, 67 were multidrug-resistant (MDR), and 11 were extensively drug-resistant (XDR). The prevalence of the blaVIM, blaIMP, blaNDM, and blaOXA−48 genes were 7 , 11 , 5 , and 28 %, respectively. The results of biofilm formation in the tissue culture plate assay indicated that 75 (75 %) strains could produce biofilm and only 25 (25 %) isolates were not able to form biofilm. Among these isolates, 25 % formed fully established biofilms, 19 % were categorized as moderately biofilm-producing, 31 % formed weak biofilms, and 25 % were non-biofilm-producers. The antimicrobial resistance among biofilm former strains was found to be significantly higher than that of non-biofilm former strains (p < 0.05). Molecular distribution of biofilm formation genes revealed that 98 , 96 , and 34 % of the isolates carried luxS, treC, and wza genes, respectively. Conclusions The rise of antibiotic resistance among biofilm-producer strains demonstrates a serious concern about limited treatment options in the hospital settings. All of the data suggest that fundamental actions and introduction of novel strategies for controlling of K. pneumoniae biofilm-related infections is essential.

scholarly journals Genomic analysis reveals high virulence and antibiotic resistance amongst phage susceptible Acinetobacter baumannii

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Udomluk Leungtongkam ◽  
Rapee Thummeepak ◽  
Thawatchai Kitti ◽  
Kannipa Tasanapak ◽  
Jintana Wongwigkarn ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Antibiotic Resistance Genes ◽  
Genomic Analysis ◽  
Multidrug Resistant ◽  
Copper Tolerance ◽  
Virulence Determinants ◽  
Genome Sequences ◽  
High Virulence

Abstract In this study, we examined the association between antimicrobial resistance, CRISPR/Cas systems and virulence with phage susceptibility in Acinetobacter baumannii and investigated draft genomes of phage susceptible multidrug resistant A. baumannii strains from Thailand. We investigated 230 A. baumannii strains using 17 lytic A. baumannii phages and the phage susceptibility was 46.5% (107/230). Phage susceptibility was also associated with resistance to numerous antibiotics (p-value < 0.05). We also found association between biofilm formation and the presence of ompA gene among phage susceptible A. baumannii strains (p-value < 0.05). A. baumannii isolates carrying cas5 or combinations of two or three other cas genes, showed a significant increase in phage resistance. Whole-genome sequences of seven phage susceptible A. baumannii isolates revealed that six groups of antibiotic resistance genes were carried by all seven phage susceptible A. baumannii. All strains carried biofilm associated genes and two strains harbored complete prophages, acquired copper tolerance genes, and CRISPR-associated (cas) genes. In conclusion, our data exhibits an association between virulence determinants and biofilm formation among phage susceptible A. baumannii strains. These data help to understand the bacterial co-evolution with phages.

scholarly journals Effect of Glucose Induction on Biofilm Density in Clinical Isolate Acinetobacter baumannii Patients in Intensive Care Unit of Dr. Soetomo Hospital, Surabaya

2020 ◽  
Vol 56 (2) ◽  
pp. 118
Author(s):  
Wira W Lindarto ◽  
Eddy Bagus Wasito ◽  
Kartuti Debora
Keyword(s):  
Tissue Culture ◽  
Acinetobacter Baumannii ◽  
Clinical Isolate ◽  
Growth Media ◽  
Plate Method ◽  
Culture Plate ◽  
Tissue Culture Plate ◽  
Glucose Induction ◽  
Sugar Levels ◽  
Effect Of Glucose

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.

scholarly journals Evaluasi Metode Skrining Biofilm Enterococcus faecalis Isolat Klinik Kateter Urin

2019 ◽  
Author(s):  
Wani Devita Gunardi ◽  
Mohamad Yanuar Prasetyo Nugroho ◽  
Elisabeth D. Harahap
Keyword(s):  
Tissue Culture ◽  
Enterococcus Faecalis ◽  
Congo Red ◽  
National Healthcare ◽  
National Healthcare Safety Network ◽  
Culture Plate ◽  
Tissue Culture Plate

Laporan National Healthcare Safety Network dari tahun 2006 - 2008, menunjukan penyebab paling umum kedua infeksi saluran kemih (ISK) terkait kateter adalah genus Enterococcus setelah Eschericia coli. Pada infeksi saluran kemih terkait kateter urin, faktor yang berperan penting dalam patogenesis infeksi ini, yaitu: pembentukan biofilm pada kateter urin. Peranan Enterococcus faecalis sebagai penyebab infeksi saluran kemih berkaitan dengan kemampuannya dalam membentuk biofilm. Ada beberapa variasi metode untuk mendeteksi pembentukan biofilm seperti Tissue Culture Plate (TCP), Tube method (TM), dan Congo Red Agar (CRA). Tujuan penelitian ini untuk mendapatkan metode deteksi pembentukan biofilm dari E. faecalis yang tepat, cepat, dan mudah dilakukan. Total tigabelas isolat bakteri E. faecalis yang didapat dari hasil isolasi kultur kateter urin dilakukan uji deteksi pembentukan biofilm dengan metode TCP sebagai baku emas dan CRA sebagai pemeriksaan pembanding. Hasilnya, didapatkan 61,5% dan 69,2% bakteri E. faecalis mampu menghasilkan biofilm menggunakan metode TCP dan CRA. Hasil uji diagnostik metode CRA dibandingkan dengan metode TCP untuk deteksi pembentukan biofilm, didapatkan sensitivitas dan spesifisitas dari CRA sebesar 75% dan 40%. CRA merupakan metode yang cepat dan mudah untuk dilakukan, namun memiliki spesifitas yang kurang baik. Hal ini dapat disebabkan pembacaan hasil yang bersifat subjektif dan menimbulkan kesalahan paralaks. Kata kunci : Enterococcus faecalis, Kateter Urin, Biofilm.

scholarly journals Phenotypic and genotypic characterization of biofilm producing clinical coagulase negative staphylococci from Nepal and their antibiotic susceptibility pattern

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Sarita Manandhar ◽  
Anjana Singh ◽  
Ajit Varma ◽  
Shanti Pandey ◽  
Neeraj Shrivastava
Keyword(s):  
Tissue Culture ◽  
Congo Red ◽  
Antibiotic Susceptibility ◽  
Clinical Samples ◽  
Susceptibility Pattern ◽  
Coagulase Negative Staphylococci ◽  
Antibiotic Susceptibility Pattern ◽  
Biofilm Production ◽  
Culture Plate ◽  
Tissue Culture Plate

Abstract Background Coagulase-negative staphylococci (CNS) survive as commensals of skin, anterior nares and external canals of human and were regarded as non-infectious pathogens. However, they are emerging as a major cause of nosocomial infectious due to their ability to form biofilms and high resistance to several classes of antibiotics. This study examines the biofilm forming abilities of 214 clinical CNS isolates using phenotypic and genotypic methods, and determines their antibiotic susceptibility patterns. Methods A total of 214 clinical isolates collected from different clinical samples were identified as CNS and their antibiotic susceptibility determined by CLSI guidelines. The biofilm forming ability of all isolates was determined by three phenotypic methods; Congo red agar (CRA) method, tube adherence method (TM) and tissue culture plate (TCP) method and by genotypic method for the detection of icaAD genes. Results Among all the isolates, S. epidermidis (57.5%) was found the most frequently, followed by S. saprophyticus (18.7%), S. haemolyticus (11.2%), S. hominis (7%), and S. capitis (5.6%). Antibiotic susceptibility pattern demonstrated 91.6% isolates were resistant to penicillin and 66.8% to cefoxitin while 91.1% isolates were susceptible to chloramphenicol. Constitutive and inducible clindamycin resistant phenotype as measured by D-test was seen among 28% and 14.5% of isolates respectively. Tissue culture plate method detected biofilm production in 42.1% isolate followed by 31.8% through tube method while 20.1% isolates were found to produce slime in Congo red agar method. The genotypic assay revealed presence of icaA and icaD genes in 19.2% isolates. Conclusion The study shows a high prevalence of biofilm formation and inducible clindamycin resistance in CNS isolates, indicating the importance of in-vitro biofilm production test and D-test in routine laboratory diagnostics. Implementation of efficient diagnostic techniques for detection of biofilm production in clinical samples can help manage staphylococcal infections and minimize risks of treatment failures in hospitals.

scholarly journals Acinetobacter baumannii: Identification, Antibiotic Sensitivity and Biofilm Formation in Different Clinical Samples

2018 ◽  
Vol 12 (2) ◽  
pp. 4-9
Author(s):  
Maherun Nesa ◽  
Shaheda Anwar ◽  
Ahmed Abu Saleh
Keyword(s):  
Tissue Culture ◽  
Acinetobacter Baumannii ◽  
Pleural Fluid ◽  
Biofilm Formation ◽  
Antibiotic Sensitivity ◽  
Tracheal Aspirate ◽  
Clinical Samples ◽  
Plate Method ◽  
Acinetobacter Spp ◽  
Tissue Culture Plate

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

scholarly journals The Role of Biofilm Formation in Antibiotic Resistance of Bacteria Isolated from Saliva of Patients with Dental Caries

2021 ◽  
pp. 40-49
Author(s):  
Merriam Ghadhanfar Alwan ◽  
Hadeel Adil Al Rubaye ◽  
Noor Adil Abood ◽  
Hind Tahseen Ibrahem ◽  
Hamiza Bt Hamidon ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Antibiotic Resistance ◽  
Dental Caries ◽  
Antimicrobial Resistance ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Rrna Gene ◽  
Tissue Culture Plate

Objectives: This study aim to determine the bacterial diversity, biofilm forming ability and the antimicrobial resistance of bacteria isolated from saliva of patients with dental caries conditions with the using of 16S rRNA gene sequencing technique for identification of the most virulent isolates. Methods: Isolation and identification of microorganisms were done employing standard bacteriologic techniques, followed by biofilm detection using tissue culture plate method. The strong biofilm forming isolates were selected for antibiotic susceptibility test against selected antibiotics using disk diffusion technique. In order to identify the selected isolates. The genomic DNA obtained following the extraction process were used for the amplification of the bacterial 16S rRNA gene. Results: A total of 137 bacterial isolates were obtained and identified as belonging to 21 genera. Tissue culture plate (TCP) method were employed for screening the isolates according to its biofilm forming ability, its showed that 55 (40.1%) of the total isolates were strong, 57 (41.6%) were moderate and 25 (18.3%) were weak biofilm producers. The antimicrobial susceptibility test showed the multi antibiotics resistance of the strong biofilm former isolates to the conventional antibiotics. Enterococcus faecalis isolates showed the highest biofilm formation and antibiotic resistance. The 16S rRNA gene for two of these isolates have been amplified using PCR and the product sequenced, analyzed and registered in the National Center for Biotechnology Information (NCBI) as UKMS1 and UKMS2 and the accession numbers KX960104.1 and KX960105.1 respectively. Conclusion: The study has revealed that antimicrobial resistance of bacteria isolates from saliva of patients with dental caries conditions is associated with biofilm formation. Other uncommon pathogenic bacteria were also isolated in this study as a result of the use of non-selective enrichment medium for culturing. Enterococcus faecalis isolates indicated the highest biofilm formation and antibiotic resistance.

scholarly journals Decreasing Prevalence of Multidrug-Resistant Acinetobacter Baumannii in Rīga East University Hospital / Multirezistentās Acinetobacter Baumannii Izplatības Mazināšanās Rīgas Austrumu Klīniskajā Universitātes Slimnīcā

2016 ◽  
Vol 70 (4) ◽  
pp. 232-236
Author(s):  
Māris Liepiņš ◽  
Raimonds Sīmanis ◽  
Aivars Lejnieks
Keyword(s):  
Infection Control ◽  
Acinetobacter Baumannii ◽  
Venous Catheter ◽  
Multidrug Resistant ◽  
Control Measures ◽  
University Hospital ◽  
Hospital Environment ◽  
Central Venous ◽  
Infection Control Measures ◽  
Time Period

Abstract There has been an increasing tendency of infections caused by multidrug-resistant organisms (MDRO), including multidrug-resistant Acinetobacter baumannii (MDRAB), in the Rīga East University Hospital (REUH) during the last decade. Over the last two years (2014-2015), this tendency has reversed and the prevalence of MDRAB has decreased considerably. In this study we assessed the prevalence of MDRAB in intensive care units (ICUs), internal medicine, surgery units and analysed antibiotic sensitivity profiles. In addition, we determined if current infection control measures are preventing further increase of infections caused by MDRAB in REUH. Retrospective Acinetobacter baumannii prevalence data were collected for the period from 2009 until 2012. For the time period from the beginning of 2013 until 2015, after implementing such infection control measures as control of compliance to hand hygiene guidelines, a review of central venous catheter insertion protocols and regular search for sources of MDRAB in hospital environment, prospective follow-up of new cases was conducted. Antimicrobial sensitivity profiles were assessed for the period from 2013 until 2015. Data were processed with the statistical software WHONET 5.5. Bacteria identification and antibiotic susceptibility testing were performed by VITEK 2 compact, BioMerieux, France. The prevalence of MDRAB in the period 2009 to 2013 increased from 71 to 217 cases per year, but from between 2013 (time of implementing infection control measures) and 2015 it decreased to 113 cases in 2015. In the three year period (2013-2015), the proportion of MDRAB causing bloodstream infections (BSI) and central nervous system infections (CNSI) was 15.85% from all identified MDRAB cases. Of the 113 MDRAB infections diagnosed in 2015, BSI was found in 16.81% cases (n = 19). Antibiotic resistance testing showed that colistin is the most effective drug against MDRAB. The majority of Acinetobacter baumannii isolates were resistant to Ampicillin/Sulbactam, Piperacillin/Tazobactam, Ceftazidime, Cefepime, Imipenem, Meropenem, Amikacin, Gentamicin, Tobramycin, and Ciprofloxacin. Over the last two years (2014-2015), prevalence of MDRAB infections decreased considerably. In the time period from 2013 to 2014, resistance of Acinetobacter baumannii increased to imipenem, ciprofloxacin and colistin, while decreased slightly to amikacin. Rigorous infection control measures, such as identification and elimination of new MDRAB sources in environment, review of the central venous catheter insertion protocol and improvements in hand hygiene, are crucial for decreasing distribution of and invasive infections caused by MDRAB in the hospital environment.

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