scholarly journals Characterization of Aminoglycoside Modifying Enzymes Producing E. coli and Klebsiella pneumoniae Clinical Isolates

2021 ◽  
Author(s):  
Eman El-Gebaly ◽  
Mohammed Farrag ◽  
Tarek Dishisha ◽  
Walid Bakeer
Keyword(s):  
16S Rrna ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Aminoglycoside Resistance ◽  
Efficient Treatment ◽  
E Coli ◽  
Isolation And Characterization ◽  
Antimicrobial Resistance Gene

Antimicrobial resistance gene profile characterization and dissemination offer useful detail on the possible challenge in treating bacteria. The development of aminoglycoside modifying enzymes (AMEs) is considered as the primary mechanism of resistance to aminoglycosides, in addition to the 16S rRNA methylases. This study aimed at isolation and characterization of aminoglycosides resistant clinical isolates of enterobacteriaceae family from different clinical samples. Over a period of 24 months, thirty samples were collected and 49 clinical isolates of E. coli [n=25], Klebsiella [n=13], Enterobacter species (n=7) and Proteus species (n=4) were isolated from Egyptian clinical laboratories. The identities of the cultures were confirmed following standard microbiological procedures. Resistance of the isolates to aminoglycosides was determined by the disc diffusion method and isolates with highest resistance (n=9) were selected and investigated for 16S rRNA methylase and AMES encoding genes by polymerase chain reaction (PCR) and sequencing. In general, aminoglycoside resistance was found in 95% of the isolates; the isolates displayed the highest rate of resistance to netilmicin (75%) and kanamycin (55%), while resistance to gentamycin (18%) and tobramycin (16%) was low. A total of 9 isolates have the highest aminoglycoside resistant rate, showed the highest appearance for aac(6′)-Ib as well as ant (3″)-Ia resistant genes, with aac (3)-II (44%) and ant (4′)-IIb (34%) following closely. The high prevalence of AMEs observed among resistant isolates in this study suggests the urgent need for more efficient treatment designs to mitigate the selection burden as well as improved care of patients who have been infected with these drug-resistant organisms.

Functional and Structural Characterization of Acquired Pan-Aminoglycoside Resistance 16S rRNA Methyltransferase NpmB1

2021 ◽  
Author(s):  
Akito Kawai ◽  
Masahiro Suzuki ◽  
Kentaro Tsukamoto ◽  
Yusuke Minato ◽  
Yohei Doi
Keyword(s):  
Amino Acid ◽  
16S Rrna ◽  
Amino Acid Identity ◽  
Single Amino Acid ◽  
Aminoglycoside Resistance ◽  
E Coli ◽  
The United Kingdom ◽  
Amino Acid Variant ◽  
A Site

Post-translational methylation of the A site of 16S rRNA at position A1408 leads to pan-aminoglycoside resistance encompassing both 4,5- and 4,6-disubstituted 2-deoxystreptamine (DOS) aminoglycosides. To date, NpmA is the only acquired enzyme with such function. Here, we present function and structure of NpmB1 whose sequence was identified in Escherichia coli genomes registered from the United Kingdom. NpmB1 possesses 40% amino acid identity with NpmA1 and confers resistance to all clinically relevant aminoglycosides including 4,5-DOS agents. Phylogenetic analysis of NpmB1 and NpmB2, its single amino acid variant, revealed that the encoding gene was likely acquired by E. coli from a soil bacterium. The structure of NpmB1 suggests that it requires a structural change of the β6/7 linker in order to bind to 16S rRNA. These findings establish NpmB1 and NpmB2 as the second group of acquired pan-aminoglycoside resistance 16S rRNA methyltransferases.

scholarly journals CHARACTERIZATION OF LACTIC ACID BACTERIA AND ANTIMICROBIAL ACTIVITY IN SUI WU’U FROM BAJAWA DISTRICT, NUSA TENGGARA TIMUR, INDONESIA

2020 ◽  
pp. 44-49
Author(s):  
ROSALINA YULIANA AYEN ◽  
ENDANG KUSDIYANTINI ◽  
SRI PUJIYANTO
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
16S Rrna ◽  
Diffusion Method ◽  
E Coli ◽  
Query Cover

Objective: This research aimed to isolate, determine the characteristics of lactic acid bacteria (LAB) of Sui Wu’u from Bajawa, Nusa Tenggara Timur and identify LAB using 16S rRNA potential as antimicrobial activity against pathogenic bacteria. Methods: Sui Wu’u which has been stored for 6 months was obtained from Bajawa district, inoculated on de Man Rogosa-Sharpe Agar (Merck) + 0.5% CaCO3, purification of LAB, characterization of selected isolates, biochemical test, tolerance test for pH, viability to test temperature, and content NaCl, determination of antimicrobial action by the agar well disk diffusion method using antibiotic (Amoxicillin) as a control and as indicator bacteria (Staphylococcus aureus and Escherichia coli) and isolation of genomic 16S rRNA; molecular identification. Results: Based on research results obtained five isolates of LAB, Gram staining the LAB isolated from Sui Wu’u showed that the isolated bacteria (bacilli and coccus) are Gram-positive, catalase-negative and the isolates have tolerance of viability at temperatures of 10°C, 45°C, and 50°C and to salinitas of 4% and 6.5%. The inhibitory zone LAB isolates (2PKT) against E. coli bacteria (20 mm) and S. aureus (12 mm), and (2PKB) against E. coli bacteria (17 mm) and S. aureus (10 mm). The two selected isolates were identified as Lactobacillus fermentum strain HB bacteria with 100% identification value and 98.93% query cover and L. fermentum strain HT with 100% identification value and 99.23% query cover. Conclusion: L. fermentum from Sui Wu’u has antibacterial activity against Staphylococcus aureus and Escherichia coli.

scholarly journals Genetic Characterization of a Novel Composite Transposon Carrying armA and aac(6)-Ib Genes in an Escherichia coli Isolate from Egypt

2017 ◽  
Vol 66 (2) ◽  
pp. 163-169
Author(s):  
Mona T. Kashef ◽  
Omneya M. Helmy
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Agents ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Aminoglycoside Resistance ◽  
Disk Diffusion Method ◽  
Gram Negative ◽  
Coli Isolate ◽  
Wide Range

Aminoglycosides are used in treating a wide range of infections caused by Gram-positive and Gram-negative bacteria; however, aminoglycoside resistance is common and occurs by several mechanisms. Among these mechanisms is bacterial rRNA methylation by the 16S rRNA methyl transferase (16S-RMTase) enzymes; but data about the spread of this mechanism in Egypt are scarce. Cephalosporins are the most commonly used antimicrobial agents in Egypt; therefore, this study was conducted to determine the frequency of 16S-RMTase among third generation cephalosporin-resistant clinical isolates in Egypt. One hundred and twenty three cephalosporin resistant Gram-negative clinical isolates were screened for aminoglycosides resistance by the Kirby Bauer disk diffusion method and tested for possible production of 16S-RMTase. PCR testing and sequencing were used to confirm the presence of 16S-RMTase and the associated antimicrobial resistance determinants, as well as the genetic region surrounding the armA gene. Out of 123 isolates, 66 (53.66%) were resistant to at least one aminoglycoside antibiotic. Only one Escherichia coli isolate (E9ECMO) which was totally resistant to all tested aminoglycosides, was confirmed to have the armA gene in association with blaTEM-1, blaCTX-M-15, blaCTX-M-14 and aac(6)-Ib genes. The armA gene was found to be carried on a large A/C plasmid. Genetic mapping of the armA surrounding region revealed, for the first time, the association of armA with aac(6)-Ib on the same transposon. In conclusion, the isolation frequency of 16S-RMTase was low among the tested aminoglycoside-resistant clinical samples. However, a novel composite transposon has been detected conferring high-level aminoglycosides resistance.

scholarly journals Detection of CTX-M-type ESBLs from Escherichia coli Clinical Isolates from a Tertiary Hospital, Malaysia

2019 ◽  
Vol 16 (3(Suppl.)) ◽  
pp. 0682 ◽  
Author(s):  
MKK Et al.
Keyword(s):  
Escherichia Coli ◽  
Clinical Specimen ◽  
Pcr Amplification ◽  
Tertiary Hospital ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Resistance Rates

The present study aims to detect CTX-M-type ESBL from Escherichia coli clinical isolates and to analyze their antibotic susceptibility patterns. One hundred of E. coli isolates were collected from different clinical samples from a tertiary hospital. ESBL positivity was determined by the disk diffusion method. PCR used for amplification of CTX-M-type ESBL produced by E. coli. Out of 100 E. coli isolates, twenty-four isolates (24%) were ESBL-producers. E. coli isolated from pus was the most frequent clinical specimen that produced ESBL (41.66%) followed by urine (34.21%), respiratory (22.23%), and blood (19.05%).  After PCR amplification of these 24 isolates, 10 (41.66%) isolates were found to possess CTX-M genes. The CTX-M type ESBL producing E. coli against antibiotics belonging to different families showed the highest resistance rates to Ampicillin (100%), Cefotaxime (97%), Cefuroxime (95%), and Ciprofoxacin (86%). Carbapenem groups of antibiotics, Meropenem (89%) and Imipenem (85%) have the highest susceptibility rate among all antibiotics used in this study. The outcome of the antimicrobial susceptibility testing of significant CTX-M- type ESBL producing E. coli could be useful to avoid failure or prolong treatments.

scholarly journals PREVALENCE AND MOLECULAR CHARACTERIZATION OF blaCTX-M-15-PRODUCING PATHOGENIC GRAM-NEGATIVE BACTERIA FROM VARIOUS CLINICAL SAMPLES

2018 ◽  
Vol 11 (10) ◽  
pp. 386
Author(s):  
Sindhuja S ◽  
Sureshkumar Bt ◽  
Janaki S ◽  
Thenmozhi S
Keyword(s):  
Molecular Characterization ◽  
Pathogenic Bacteria ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli

Objective: The objective of this study was to describe the prevalence and molecular characterization of blaCTX-M-15-producing pathogenic Gram-negative bacteria from various clinical samples isolated from clinically suspected patients.Methods: In this study, clinical samples of urine, stool, sputum, and pus were collected from 244 patients with nosocomial infections. The phenotypic identification of extended-spectrum β-lactamases (ESBL) was confirmed by double-disk synergy test and combined disk diffusion test. In vitro, the susceptibility pattern of antimicrobial agents against pathogenic isolates was performed by Kirby–Bauer disk diffusion method. The identification of blaCTX-M-15-producing Escherichia coli was assessed by polymerase chain reaction method.Results: The frequency of ESBL-producing pathogenic bacteria from screened was 6 (46.15%). In vitro, susceptibility to pathogenic bacteria showed that the majority of isolates were highly susceptible to amoxicillin-clavulanic acid (97.87%), ofloxacin (93.33%), and Pseudomonas aeruginosa showed 100% sensitive to ceftazidime, cefotaxime, cefixime, cefoperazone, and meropenem (92.30%). The rates of resistance to other antibiotics varied from <26.66%. Among six tested isolates, only one E. coli isolates showed blaCTX-M-15 gene.Conclusion: Due to the increase of E. coli with multiple ESBL genes, continuous surveillance should be needed in clinical field to use of appropriate antibiotics and the control of infections.

scholarly journals Isolation and Characterization of Antibiotic Producing Actinomycetes from Mud Nest of Wasps

2020 ◽  
pp. 1-10
Author(s):  
Md. Fazlul Haque ◽  
Sabina Sultana ◽  
Moni Krishno Mohanta ◽  
Md. Ariful Hasan ◽  
Arnaba Saha Chaity ◽  
...  
Keyword(s):  
16S Rdna ◽  
Saline Solution ◽  
Antimicrobial Efficacy ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Disc Diffusion Method ◽  
E Coli ◽  
Isolation And Characterization ◽  
Ncbi Blast

The recent increase in antibiotic resistance demands the discovery of novel antibiotics. Hence, this project was designed to explore novel antibiotic producing Actinomycetes from mud nest of wasps. For this, 9 types of active mud nests of wasp available in Rajshahi, Bangladesh were collected. For each nest, nest material was aseptically homogenized with a 1X saline solution and then diluted homogenate was plated in Actinomycetes Isolation Agar medium to isolate Actinomycetes. Total 27 purified cultures of bacteria were isolated from 9 collected mud nests of wasp. To collect the extract of mud nest, homogenate was filtered and centrifuged. Then, the extracts were assessed for their efficacy to inhibit bacterial growth with disc diffusion method. However, only extract of nest number 9 (N9) showed antimicrobial efficacy against tested bacteria, E. coli. Then antimicrobial efficacy of the 27 isolates was assessed using an agar cross-streak method and disc diffusion method. It was found that among the 27 isolates; only the isolate N9C2 was able to inhibit the growth of studied bacteria, E. coli. Then, 16S rDNA was isolated, amplified and sequenced from the isolate N9C2 for its identification. According to NCBI blast, the highest similarity of sequence (99%) of 16S rDNA of the isolate N9C2 was shown to that of Streptomyces coelescens strain AS 4.1594. Then, the isolate N9C2 was characterized. It was found that the isolate was a gram positive filamentous bacterium. It was found that the isolate N9C2 was resistant to Amoxicillin, Ampicillin and Cephalexin while it was sensitive to Tetracycline, Erythromycin and Ciprofloxacin. It was also found that the isolate N9C2 can grow optimally at pH 7 and at 37ºC. Finally, it can be concluded that mud nests of wasp is a vital source of antibiotic producing Actinomycetes such as Streptomyces coelescens strain AS 4.1594.

scholarly journals Molecular characterization of clinical carbapenem-resistant Enterobacterales from Qatar

2021 ◽  
Author(s):  
Fatma Ben Abid ◽  
Clement K. M. Tsui ◽  
Yohei Doi ◽  
Anand Deshmukh ◽  
Christi L. McElheny ◽  
...  
Keyword(s):  
Common Species ◽  
Clinical Samples ◽  
Whole Genome ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Genes Encoding ◽  
Encoding Genes ◽  
Sequence Types ◽  
Common Sequence

AbstractOne hundred forty-nine carbapenem-resistant Enterobacterales from clinical samples obtained between April 2014 and November 2017 were subjected to whole genome sequencing and multi-locus sequence typing. Klebsiella pneumoniae (81, 54.4%) and Escherichia coli (38, 25.5%) were the most common species. Genes encoding metallo-β-lactamases were detected in 68 (45.8%) isolates, and OXA-48-like enzymes in 60 (40.3%). blaNDM-1 (45; 30.2%) and blaOXA-48 (29; 19.5%) were the most frequent. KPC-encoding genes were identified in 5 (3.6%) isolates. Most common sequence types were E. coli ST410 (8; 21.1%) and ST38 (7; 18.4%), and K. pneumoniae ST147 (13; 16%) and ST231 (7; 8.6%).

scholarly journals Isolation and Characterization of Novel Human Parechovirus from Clinical Samples

2007 ◽  
Vol 13 (6) ◽  
pp. 889-895 ◽  
Author(s):  
Kanako Watanabe ◽  
Masayasu Oie ◽  
Masaya Higuchi ◽  
Makoto Nishikawa ◽  
Masahiro Fujii
Keyword(s):  
Clinical Samples ◽  
Human Parechovirus ◽  
Isolation And Characterization

scholarly journals Characterization of bacteriocin and chitinase producing bacterial isolates with broad-spectrum antimicrobial activities

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Muhammad Yasir ◽  
Basit Zeshan ◽  
Nur Hardy A. Daud ◽  
Izzah Shahid ◽  
Hafza Khalid
Keyword(s):  
Antimicrobial Activity ◽  
Inhibitory Activity ◽  
Antifungal Drugs ◽  
Proteinase K ◽  
Diffusion Method ◽  
List Type ◽  
Bacterial Isolates ◽  
E Coli ◽  
Inhibitory Potential

Abstract There is a need for more efficient and eco-friendly approaches to overcome increasing microbial infections. Bacteriocins and chitinases from Bacillus spp. can be powerful alternatives to conventional antibiotics and antifungal drugs, respectively. The purpose of this study was to assess the inhibitory potential of bacteriocins and chitinase enzymes against multiple resistant bacterial and fungal pathogens. Bacterial isolates were selected by growth on minimal salts medium and after that were morphologically and biochemically characterized. The physiochemical characterization of bacteriocins was carried out. The inhibitory potential of bacteriocins towards six pathogenic bacteria was determined by the well diffusion assay while chitinase activity towards three fungal strains was determined by the dual plate culture assay. Two bacterial strains (WW2P1 and WRE4P2), out of nine showed inhibition of K. pneumonia, P. aeruginosa, E. coli and MRSA while WW4P2 was positive against S. typhimurium and E. coli and WRE10P2 against P. aeruginosa, S. pneumoniae. Two bacterial isolates (WW3P1 and WRE10P2) were chosen for further study on the basis of their antifungal activities. Of these, WW3P1 isolate was more effective against A. fumigatus as well as A. niger. The proteinaceous nature of the bacteriocins was confirmed by treatment of the crude extract with proteinase K. It was found that the inhibitory activity of strain WW3P1 against E. coli was highest at 20 °C, and against S. pneumoniae it was at 20 °C and pH 10 after treatment with EDTA. Inhibition by strain the WRE10P2 against P. aeruginosa was highest at 20 °C and pH 14. It was found that EDTA increased the inhibitory activity of strain WW2P1 against P. aeruginosa, K. pneumoniae and E. coli by 2 ± 0.235, 3.5 ± 0.288, 2.5 ± 1.040 times, respectively, of strain WRE4P2 against P. aeruginosa and E. coli by 2.5 ± 0.763, 2.7 ± 0.5 times, respectively, and of strain WRE10P2 against S. pneumoniae by 3 ± 0.6236 times. The isolates have promising inhibitory activity, which should be further analyzed for the commercial production of antimicrobials. Article highlights The current study aimed to isolate the microbiome from wheat plant (Triticum aestivum L.), to screen for bacteriocin production and to assess its antimicrobial activity against human pathogens. Forty-one phenotypically different bacterial colonies were subjected to bacteriocin purification from which 25 colonies showed positive reactions. These 25 bacterial isolates were screened against six different human bacterial pathogens using the well diffusion method to check the antimicrobial activity. Out of nine bacterial isolates, WW3P1 and WRE10P2 were able to degrade the chitin and utilize it as their sole energy source. Strain WRE4P2 exhibited partial inactivation in its activity against MRSA after treatment with proteinase K.

scholarly journals Isolation and characterization of escherichia coli in ready-to-eat foods vended in Islamic University, Kushtia

1970 ◽  
Vol 18 ◽  
pp. 99-103 ◽  
Author(s):  
S Biswas ◽  
MAK Parvez ◽  
M Shafiquzzaman ◽  
S Nahar ◽  
MN Rahman
Keyword(s):  
Escherichia Coli ◽  
Pattern Analysis ◽  
University Campus ◽  
Rflp Pattern ◽  
E Coli ◽  
Fish Meat ◽  
Isolation And Characterization ◽  
Food Borne ◽  
Identification And Characterization

Context: Escherichia coli is shed in the feces of warm blooded animals and humans and thus potential for public health. Detection and characterization of E. coli in the ready-to-eat (RTE) foods concerns due to their presence indicates fecal contamination of the food.   Objective: To identify, characterize and RFLP pattern analysis of E. coli isolated from RTE foods vended in Islamic University campus, Kushtia.   Materials and Methods: Fifty samples from four types of consumed foods in six student halls of residence, some temporary restaurants of Islamic University, Kushtia were assessed for bacterial contamination by standard methods. Identification and characterization of E. coli isolates were performed using IMViC tests. Genomic DNA was used to perform RFLP pattern analysis.   Results: Thirty seven out of 50 (74%) examined samples of RTE foods had E. coli contamination. The highest number of E. coli was isolated from vegetable oriented RTE foods (90.90%) and fish, meat and cereals samples were also significantly E. coli positive. RFLP profiling of two E. coli isolates were observed.   Conclusion: The results of this study provide evidence that some RTE foods had unsatisfactory levels of contamination with E. coli. Thus street vended RTE food could be important potential vehicles for food-borne diseases. Molecular characterization may be exploited to identify food borne pathogen among different species.  Keywords: Ready-to-eat foods; Escherichia coli; RFLP pattern DOI: http://dx.doi.org/10.3329/jbs.v18i0.8783 JBS 2010; 18(0): 99-103

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