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

Author(s):  
Merriam Ghadhanfar Alwan ◽  
Hadeel Adil Al Rubaye ◽  
Noor Adil Abood ◽  
Hind Tahseen Ibrahem ◽  
Hamiza Bt Hamidon ◽  
...  

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.

Author(s):  
Shadi Shadkam ◽  
Hamid Reza Goli ◽  
Bahman Mirzaei ◽  
Mehrdad Gholami ◽  
Mohammad Ahanjan

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.


2020 ◽  
Vol 8 (8) ◽  
pp. 604
Author(s):  
Meng-Qi Ye ◽  
Guan-Jun Chen ◽  
Zong-Jun Du

The effect of antibiotics on the diversity and functioning of indigenous microorganisms in the environment has attracted much attention. In this study, effects of exposure to six different antibiotics on the bacterial community, metabolic functions and antibiotic resistance genes (ARGs) in marine sediments during enrichment culturing were investigated. Classical culture-dependent method and high-throughput 16S rRNA gene sequencing method were both applied. In the culture-dependent analysis, the obtained 1549 isolates belonged to four phyla (Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria) and 155 genera. Proteobacteria and Firmicutes were the dominant phyla. The diversity and abundance of obtained bacteria after antibiotic processing exhibited different degrees of decrease. Enrichment culturing for different time could also affect the bacterial community composition. Some genera of bacteria were not isolated in the control group, but they could be isolated in the antibiotic-treated groups. In high-throughput 16S rRNA gene amplicon sequencing analyses, all the effective reads were clustered into 2822 OTUs at 97% similarity cutoff; they were annotated to 49 phyla, 103 class, 220 orders, 347 families, 624 genera and 1122 species. An alpha diversity analysis indicated that the community diversity and richness decreased under antibiotic exposure. The changes at the genus level were much more obvious. Only 48 genera of 129 genera were shared by all the samples. A total of 29 genera which were not detected in the initial control sample could be detected in at least one antibiotic-treated group. SIMPER analysis showed that OTU2543 and OTU1450 were the most common taxa to the dissimilarity of bacterial community between antibiotic-treated groups and the control group. OTU2034 and OUT2543 were the most contributive taxa to dissimilarity of groups incubating for different time. Metabolism was the predominant bacterial function. A total of 30 ARGs were detected in the samples. This study mainly focused on the changes of microbiota under the selective pressure of antibiotics for different time and the results demonstrated that the antibiotic could affect the bacterial diversity and richness in the marine ecosystem.


Author(s):  
Giselle K. P. Guron ◽  
Chaoqi Chen ◽  
Pang Du ◽  
Amy Pruden ◽  
Monica A. Ponder

A controlled greenhouse study was performed to determine the effect of manure or compost amendments, derived during or in absence of antibiotic treatment of beef and dairy cattle, on radish taproot-associated microbiota and indicators of antibiotic resistance when grown in different soil textures. Bacterial beta-diversity, determined by 16S rRNA gene amplicon sequencing, bifurcated according to soil texture (p<0.001, R=0.501). There was a striking cross-effect in which raw manure from antibiotic-treated and antibiotic-free beef and dairy cattle added to loamy sand (LS) elevated relative (16S rRNA gene-normalized) (by 0.9-1.9 log10) and absolute (per radish) (by 1.1-3.0 log10) abundances of intI1 (an integrase gene and indicator of mobile multi-antibiotic resistance) on radishes at harvest compared to chemical fertilizer only control conditions (p<0.001). Radishes tended to carry fewer copies of intI1 and sul1 when grown in silty clay loam than LS. Composting reduced relative abundance of intI1 on LS-grown radishes (0.6-2.4 log10 decrease vs corresponding raw manure; p<0.001). Effects of antibiotic use were rarely discernable. Heterotrophic plate count bacteria capable of growth on media containing tetracycline, vancomycin, sulfamethazine, or erythromycin tended to increase on radishes grown in turned composted antibiotic-treated dairy or beef control (no antibiotics) manures relative to the corresponding raw manure in LS (0.8-2.3 log10 increase; p<0.001), suggesting that composting sometimes enriches cultivable bacteria with phenotypic resistance. This study demonstrates that combined effects of soil texture and manure-based amendments influence the microbiota of radish surfaces and markers of antibiotic resistance illuminating future research directions for reducing agricultural sources of antibiotic resistance. Importance In working towards a comprehensive strategy to combat the spread of antibiotic resistance, potential farm-to-fork routes of dissemination are gaining attention. The effects of pre-harvest factors on the microbiota and corresponding antibiotic resistance indicators on the surfaces of produce commonly eaten raw is of special interest. Here we conducted a controlled greenhouse study, using radishes as a root vegetable grown in direct contact with soil, and compared the effects of manure-based soil amendments, antibiotic use in the cattle from which the manure was sourced, composting of the manure, and soil texture, with chemical fertilizer only as a control. We noted significant effects of amendment type and soil texture on the composition of the microbiota and genes used as indicators of antibiotic resistance on radish surfaces. The findings take a step towards identifying agricultural practices that aid in reducing carriage of antibiotic resistance and corresponding risks to consumers.


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.


mBio ◽  
2015 ◽  
Vol 6 (6) ◽  
Author(s):  
Egija Zaura ◽  
Bernd W. Brandt ◽  
M. Joost Teixeira de Mattos ◽  
Mark J. Buijs ◽  
Martien P. M. Caspers ◽  
...  

ABSTRACT Due to the spread of resistance, antibiotic exposure receives increasing attention. Ecological consequences for the different niches of individual microbiomes are, however, largely ignored. Here, we report the effects of widely used antibiotics (clindamycin, ciprofloxacin, amoxicillin, and minocycline) with different modes of action on the ecology of both the gut and the oral microbiomes in 66 healthy adults from the United Kingdom and Sweden in a two-center randomized placebo-controlled clinical trial. Feces and saliva were collected at baseline, immediately after exposure, and 1, 2, 4, and 12 months after administration of antibiotics or placebo. Sequences of 16S rRNA gene amplicons from all samples and metagenomic shotgun sequences from selected baseline and post-antibiotic-treatment sample pairs were analyzed. Additionally, metagenomic predictions based on 16S rRNA gene amplicon data were performed using PICRUSt. The salivary microbiome was found to be significantly more robust, whereas the antibiotics negatively affected the fecal microbiome: in particular, health-associated butyrate-producing species became strongly underrepresented. Additionally, exposure to different antibiotics enriched genes associated with antibiotic resistance. In conclusion, healthy individuals, exposed to a single antibiotic treatment, undergo considerable microbial shifts and enrichment in antibiotic resistance in their feces, while their salivary microbiome composition remains unexpectedly stable. The health-related consequences for the gut microbiome should increase the awareness of the individual risks involved with antibiotic use, especially in a (diseased) population with an already dysregulated microbiome. On the other hand, understanding the mechanisms behind the resilience of the oral microbiome toward ecological collapse might prove useful in combating microbial dysbiosis elsewhere in the body. IMPORTANCE Many health care professionals use antibiotic prophylaxis strategies to prevent infection after surgery. This practice is under debate since it enhances the spread of antibiotic resistance. Another important reason to avoid nonessential use of antibiotics, the impact on our microbiome, has hardly received attention. In this study, we assessed the impact of antibiotics on the human microbial ecology at two niches. We followed the oral and gut microbiomes in 66 individuals from before, immediately after, and up to 12 months after exposure to different antibiotic classes. The salivary microbiome recovered quickly and was surprisingly robust toward antibiotic-induced disturbance. The fecal microbiome was severely affected by most antibiotics: for months, health-associated butyrate-producing species became strongly underrepresented. Additionally, there was an enrichment of genes associated with antibiotic resistance. Clearly, even a single antibiotic treatment in healthy individuals contributes to the risk of resistance development and leads to long-lasting detrimental shifts in the gut microbiome.


Author(s):  
Tina Rostinawati ◽  
Sulistiyaningsih Hadisoebroto ◽  
Yoppi Iskandar ◽  
Prasetyo Hadi Nugroho ◽  
Audria Amanda Tara

Objective: This study aims to identify the bacteria that cause necrotic pulp in teeth of dental patients and test resistance of the bacteria found to antibiotics. Methods: Bacteria were taken with paper points that were inserted into the root canal of patients at the Dental Hospital of the Faculty of Dentistry, Universitas Padjadjaran, Sekeloa, Bandung. Bacteria were cultured and Gram-stained. Bacterial DNA was isolated to be identified by polymerase chain reactions 16S rRNA method against known sequences of bacterial DNA. Then, identified bacteria were tested for antibiotic resistance to tetracycline (30 μg), clindamycin (2 μg), amoxicillin (10 μg), and ampicillin (10 μg). Results: The 16s rRNA gene fragment of the main bacterium found was in 98% homology with 16S rRNA gene database in http://blast.ncbi.nlm. nih.gov, i.e., Pseudomonas aeruginosa and Acinetobacter schindleri. The results from inhibition zone of each antibiotic were 20.12 mm, 8.97 mm, 8.12 mm, and 8.03 mm for tetracycline, clindamycin, amoxicillin, and ampicillin, respectively, to P. aeruginosa. While inhibition zone of tetracycline to A. schindleri was 37.7 mm. Conclusion: Based on the study results, P. aeruginosa from patients with necrotic pulp samples were resistant to clindamycin, amoxicillin, ampicillin, and decreased activity to tetracycline. While Acinetobacter schindleri was still sensitive to tetracycline.


2019 ◽  
Vol 142 ◽  
pp. 111541
Author(s):  
R. Nazari-Vanani ◽  
N. Sattarahmady ◽  
H. Yadegari ◽  
M. Khatami ◽  
H. Heli

PHARMACON ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 73
Author(s):  
Pingkan Stela Mende ◽  
Johanis Pelealu ◽  
Beivy Kolondam

ABSTRACTBacteria has many important role in the digestive tract of animals. Beneficial bacteria in the digestive tract are thought to be able to inhibit the growth of pathogenic bacteria, while pathogenic bacteria can cause diseases and infections. This research aimed to grow bacteria living in cat feces and to identify it with molecular method. This study used moleculer identification based on 16S rRNA gene as marker. There were three isolate if bacteria taken from the culture. Two isolates were identified as Enterococcus faecalis (with 99% and 100% in similarity compared with GenBank database). One isolate was identified as Kurthia gibsonii (100% in similarity). Keywords: Bacteria, cat feces, MRS Agar, gen 16s rRNA ABSTRAKBakteri memiliki peran penting dalam saluran pencernaan hewan. Bakteri yang menguntungkan dalam saluran pencernaan dianggap mampu menghambat pertumbuhan bakteri patogen, sedangkan bakteri yang merugikan dalam saluran pencernaan hewan dianggap mampu menyebabkan penyakit dan infeksi. Penelitian ini bertujuan untuk menumbuhkan bakteri-bakteri yang ada dalam feses kucing dan mengidentifikasikannya dengan metode molekuler. Penelitian ini menggunakan identifikasi molekuler berdasarkan gen 16S rRNA sebagai penanda. Hasil penelitian ini mendapatkan tiga isolat bakteri. Dua diantaranya teridentifikasi sebagai Enterococcus faecalis (kemiripan 99% dan 100% dengan yang ada di GenBank). Satu isolat teridentifikasi sebagai Kurthia gibsonii (kemiripan 100%).


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