scholarly journals Escherichia coli Overexpressing a Baeyer-Villiger Monooxygenase from Acinetobacter radioresistens Becomes Resistant to Imipenem

2015 ◽  
Vol 60 (1) ◽  
pp. 64-74 ◽  
Author(s):  
Daniela Minerdi ◽  
Ivan Zgrablic ◽  
Silvia Castrignanò ◽  
Gianluca Catucci ◽  
Claudio Medana ◽  
...  

ABSTRACTAntimicrobial resistance is a global issue currently resulting in the deaths of hundreds of thousands of people a year worldwide. Data present in the literature illustrate the emergence of many bacterial species that display resistance to known antibiotics;Acinetobacterspp. are a good example of this. We report here thatAcinetobacter radioresistenshas a Baeyer-Villiger monooxygenase (Ar-BVMO) with 100% amino acid sequence identity to the ethionamide monooxygenase of multidrug-resistant (MDR)Acinetobacter baumannii. Both enzymes are only distantly phylogenetically related to other canonical bacterial BVMO proteins. Ar-BVMO not only is capable of oxidizing two anticancer drugs metabolized by human FMO3, danusertib and tozasertib, but also can oxidize other synthetic drugs, such as imipenem. The latter is a member of the carbapenems, a clinically important antibiotic family used in the treatment of MDR bacterial infections. Susceptibility tests performed by the Kirby-Bauer disk diffusion method demonstrate that imipenem-sensitiveEscherichia coliBL21 cells overexpressing Ar-BVMO become resistant to this antibiotic. An agar disk diffusion assay proved that when imipenem reacts with Ar-BVMO, it loses its antibiotic property. Moreover, an NADPH consumption assay with the purified Ar-BVMO demonstrates that this antibiotic is indeed a substrate, and its product is identified by liquid chromatography-mass spectrometry to be a Baeyer-Villiger (BV) oxidation product of the carbonyl moiety of the β-lactam ring. This is the first report of an antibiotic-inactivating BVMO enzyme that, while mediating its usual BV oxidation, also operates by an unprecedented mechanism of carbapenem resistance.

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Feleke Moges ◽  
Setegn Eshetie ◽  
Mengistu Endris ◽  
Kahsay Huruy ◽  
Dagnachew Muluye ◽  
...  

Background. Cockroaches are source of bacterial infections and this study was aimed to assess bacterial isolates and their antimicrobial profiles from cockroaches in Gondar town, Ethiopia.Methods. A total of 60 cockroaches were collected from March 1 to May 30, 2014, in Gondar town. Bacterial species were isolated from external and internal parts of cockroaches. Disk diffusion method was used to determine antibiotic susceptibility patterns. Data were entered and analyzed by using SPSS version 20;Pvalues <0.005 were considered as statistically significant.Results. Of 181 identified bacteria species, 110 (60.8%) and 71 (39.2%) were identified from external and internal parts of cockroaches, respectively.Klebsiella pneumoniae32 (17.7%),Escherichia coli29 (16%), andCitrobacterspp. 27 (15%) were the predominant isolates. High resistance rate was observed to cotrimoxazole, 60 (33.1%), and least resistance rate was noted to ciprofloxacin, 2 (1.1%). Additionally, 116 (64.1%) of the isolates were MDR strains;Salmonellaspp. were the leading MDR isolates (100%) followed byEnterobacter(90.5%) andShigellaspp. (76.9%).Conclusion. Cockroaches are the potential source of bacteria pathogens with multidrug resistant strains and hence effective preventive and control measures are required to minimize cockroach related infections.


Diagnostics ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1617
Author(s):  
Raouaa Maaroufi ◽  
Olfa Dziri ◽  
Linda Hadjadj ◽  
Seydina M. Diene ◽  
Jean-Marc Rolain ◽  
...  

Hospital environments constitute the main reservoir of multidrug-resistant bacteria. In this study we aimed to investigate the presence of Gram-negative bacteria in one Northwestern Tunisian hospital environment, and characterize the genes involved in bacterial resistance. A total of 152 environmental isolates were collected from various surfaces and isolated using MacConkey medium supplemented with cefotaxime or imipenem, with 81 fermenter bacteria (27 Escherichia coli, and 54 Enterobacter spp., including 46 Enterobacter cloacae), and 71 non-fermenting bacteria (69 Pseudomonas spp., including 54 Pseudomonas aeruginosa, and 2 Stenotrophomonas maltophilia) being identified by the MALDI-TOF-MS method. Antibiotic susceptibility testing was performed by disk diffusion method and E-Test was used to determine MICs for imipenem. Several genes implicated in beta-lactams resistance were characterized by PCR and sequencing. Carbapenem resistance was detected among 12 isolates; nine E. coli (blaNDM-1 (n = 8); blaNDM-1 + blaVIM-2 (n = 1)) and three P. aeruginosa were carbapenem-resistant by loss of OprD porin. The whole-genome sequencing of P. aeruginosa 97H was determined using Illumina MiSeq sequencer, typed ST285, and harbored blaOXA-494. Other genes were also detected, notably blaTEM (n = 23), blaCTX-M-1 (n = 10) and blaCTX-M-9 (n = 6). These new epidemiological data imposed new surveillance strategies and strict hygiene rules to decrease the spread of multidrug-resistant bacteria in this area.


2011 ◽  
Vol 2 (1) ◽  
pp. 8
Author(s):  
Ronak Bakhtiari ◽  
Jalil Fallah Mehrabadi ◽  
Hedroosha Molla Agamirzaei ◽  
Ailar Sabbaghi ◽  
Mohammad Mehdi Soltan Dallal

Resistance to b-lactam antibiotics by gramnegative bacteria, especially <em>Escherichia coli (E. coli)</em>, is a major public health issue worldwide. The predominant resistance mechanism in gram negative bacteria particularly <em>E. coli </em>is via the production of extended spectrum beta lactamase (ESBLs) enzymes. In recent years, the prevalence of b-lactamase producing organisms is increased and identification of these isolates by using disk diffusion method and no-one else is not satisfactory. So, this investigation focused on evaluating the prevalence of ESBL enzymes by disk diffusion method and confirmatory test (Combined Disk). Five hundred clinical samples were collected and 200 <em>E. coli </em>isolates were detected by standard biochemical tests. To performing initial screening of ESBLs was used from Disk diffusion method on <em>E. coli </em>isolates. A confirmation test (Combined Disk method) was performed on isolates of resistant to cephalosporin's indicators. Up to 70% isolates exhibited the Multi Drug Resistance phenotype. In Disk diffusion method, 128(64%) <em>E. coli </em>isolates which resistant to ceftazidime and cefotaxime while in Combined Disk, among 128 screened isolates, 115 (89.8%) isolates were detected as ESBLs producers. This survey indicate beta lactamase enzymes are playing a significant role in antibiotic resistance and correct detection of them in phenotypic test by using disk diffusion and combined Disk is essential for accurate recognition of ESBLs.


2019 ◽  
Vol 12 (5) ◽  
pp. 629-637 ◽  
Author(s):  
Sarah Rose Fitzpatrick ◽  
Mary Garvey ◽  
Kieran Jordan ◽  
Jim Flynn ◽  
Bernadette O'Brien ◽  
...  

Background and Aim: Teat disinfection is an important tool in reducing the incidence of bovine mastitis. Identifying the potential mastitis-causing bacterial species in milk can be the first step in choosing the correct teat disinfectant product. The objective of this study was to screen commercial teat disinfectants for inhibition against mastitis-associated bacteria isolated from various types of milk samples. Materials and Methods: Twelve commercially available teat disinfectant products were tested, against 12 mastitis-associated bacteria strains isolated from bulk tank milk samples and bacterial strains isolated from clinical (n=2) and subclinical (n=3) quarter foremilk samples using the disk diffusion method. Results: There was a significant variation (7-30 mm) in bacterial inhibition between teat disinfection products, with products containing a lactic acid combination (with chlorhexidine or salicylic acid) resulting in the greatest levels of bacterial inhibition against all tested bacteria (p<0.05). Conclusion: In this study, combined ingredients in teat disinfection products had greater levels of bacterial inhibition than when the ingredients were used individually. The disk diffusion assay is a suitable screening method to effectively differentiate the bacterial inhibition of different teat disinfectant products.


2019 ◽  
Vol 11 (03) ◽  
pp. 206-211
Author(s):  
Jaison Jayakaran ◽  
Nirupa Soundararajan ◽  
Priyadarshini Shanmugam

Abstract INTRODUCTION: Urinary tract infections (UTIs) remain as the most common infection. Catheter-associated (CA) UTI can lead to bacteremia and thereby is the leading cause of morbidity and mortality in hospitalized patients in our country. AIMS AND OBJECTIVES: This study aims to check the prevalence of CAUTI and study the phenotypic and genotypic characters of the multidrug-resistant organisms in a tertiary care hospital, with special reference to NDM-1 and OXA-23. MATERIALS AND METHODS: A total of 231 urine samples from patients with CA-UTI in different wards in a tertiary care hospital over a period of 3 months between June and August 2018 were collected and processed following the standard protocol. Antibiotic susceptibility tests were performed by disk-diffusion method. Modified Hodge test (MHT) was done to isolate carbapenem-resistant isolates, and polymerase chain reaction was done to detect NDM-1 and OXA-23. RESULTS: Out of 231 samples, 101 samples yielded significant growth. These 38 samples were Gram-negative bacilli which were resistant to carbapenems. Out of the 38 which showed carbapenem resistance, 23 were MHT positive. Out of the 23 MHT-positive isolates, 8 (21.05%) were positive for NDM-1 gene and only 1 (2.6%) was positive for the OXA-23 gene. CONCLUSION: This study has shown that carbapenem-resistant isolates from all the CA urinary tract-infected patients were 52.77% and most of them were Klebsiella. About 21% of them harbored the NDM-1 gene whereas only 2% had the OXA-23 gene. There has been an alarming increase in the spread of carbapenem resistance.


2019 ◽  
Vol 13 (2) ◽  
pp. 7-10
Author(s):  
Fatima Afroz ◽  
Shaheda Anwar ◽  
Mashrura Quraishi ◽  
GM Mohiuddin ◽  
SM Ali Ahmed ◽  
...  

Carbapenems, often agents of last resort for multidrug resistant bacterial infections are now threatened by widespread dissemination of carbapenem-resistant Enterobacteriaceae (CRE). Production of carbapenemases remain the most clinically important mechanism of carbapenem resistance in Enterobacteriaceae. The objective of this study was to determine the antibiogram pattern of carbapenemase producing Enterobacteriaceae. A cross sectional study was conducted at department of Microbiology and Immunology, BSMMU from September 2018 to August 2019. A total of 145 CRE isolates from different clinical samples were studied.Antimicrobial susceptibility was examinedby disk diffusion method and MIC of colistin by broth microdilution method. Resistant carbapenemase genes NDM and OXA-48 were identified by polymerase chain reaction. Out of 145 CRE isolates, 104 were NDM, 73 were OXA-48and 34 isolates were both NDM and OXA-48 co-producers. All the NDM and OXA-48 carbapenemase producing isolates were 100% resistant to meropenem, imipenem, ertapenem, ceftriaxone, ceftazidime, cefotaxime, cefuroxime, amoxicillin + clavulanic acid and piperacillin + tazobactam. Resistance rates of reserved antimicrobials to treat CRE isolates were also alarming. Thirty seven percent, 9.6% and 5.5 % of OXA-48 carbapenemase producers and 26.0%, 10.6% and 2.9% of NDM carbapenemase producers were resistant to colistin, polymyxin B and tigecycline respectively.Among the carbapenemase producing isolates, 16.6% (24) were multidrug resistant (MDR), 82.1% (119) were extensively drug resistant (XDR) and 1.3% (2) isolates were pan drug resistantwhich highlights the emerging therapeutic challenge for these superbugs. Bangladesh J Med Microbiol 2019; 13 (2): 7-10


2017 ◽  
Vol 9 (1) ◽  
pp. 3-8
Author(s):  
Aleya Farzana ◽  
S. M. Shamsuzzaman

The increase in antibiotic resistance coincided with the decline in production of new antibiotics. Combination antibiotic treatment is preferred in nosocomial infections caused by multidrug resistant Pseudomonas aeruginosa. In vitro synergism test by agar dilution method were used to choose the combinations which might be used in clinic. The aim of this study was to investigate the synergistic efficacy of antibiotic combinations in imipenem resistant P. aeruginosa strains. Carbapenem resistance (imipenem and meropenem) wasdetermined by disk diffusion method. Among isolated P. aeruginosa 44.9% were cabapenem resistant. The MIC of drugs among 25 imipenem resistant isolates ranged from >_ 256 mg/L to <_ 8 mg/L for imipenem, >_ 1024 mg/L to <_ 64 mg/L for ceftriaxone, >_ 256 mg/L to <_ 8 mg/L for amikacin, >_ 16 mg/L to <_ 2 mg/L for colistin, >_ 512 mg/L to <_ 16 mg/L for piperacillin/tazobactam. Among antibiotic combinations, piperacillin /tazobactam- amikacin was most effective with 80% synergism next to which was imipenem-amikacin with 60% synergism, then imipenem-colistin with 50% synergism, imipenem-ceftriaxone with 30% synergism. Only one combination (piperacillin/tazobactum -imipenem showed 20% antagonism. All these combinations had considerable proportion of additive effect which is also desirable for these multi drug resistant isolates.Bangladesh J Med Microbiol 2015; 9 (1): 3-8


2019 ◽  
Vol 16 (4(Suppl.)) ◽  
pp. 0986
Author(s):  
Al-Hasnawy Et al.

Antibiotic resistance is a problem of deep scientific concern both in hospital and community settings. Rapid detection in clinical laboratories is essential for the judicious recognition of antimicrobial resistant organisms. So, the growth of Uropathgenic Escherichia coli (UPEC) isolates with Multidrug-resistant (MDR) and Extensively Drug-resistant (XDR) profiles that thwart therapy for (UTIs) has been detected and has straight squeezed costs and extended hospital stays. This study aims to detect MDR- and XDR-UPEC isolates. Out of 42 UPEC clinical isolates were composed from UTI patients. The bacterial strains were recognized by standard laboratory protocols. Susceptibility to antibiotic was measured by the standard disk diffusion method Out of 42 Uropathogenic E. coli, 37 (88.09%) were found to be MDR while 5 isolates (11.90%) were XDR. The present study concluded high prevalence of uropathogenic Escherichia coli (UPEC) with Multidrug-resistant (MDR) isolated from urinary tract infection in Babylon province – Iraq.


2006 ◽  
pp. 131-136 ◽  
Author(s):  
Zoran Kukric ◽  
Ljiljana Topalic-Trivunovic

The work is concerned with the antibacterial effect of ethanolic solutions of cis- and trans-resveralrol (cis-.lrans-3,5.4'-trihydroxystilbene) obtained by the extraction (ethanol-water 1:1 v/v) of Polygonum cuspidatum rhizome. Antibacterial activity was tested by disk diffusion method on the following bacteria: Escherichia coli, Sarcina liitea. Bacillus subtilis and Staphylococcits sp., using extract concentrations of 5 mg/disk. All tests showed significant antimicrobial activity, whereby the extract with trans-resveratrol exhibited more significant effect than the extract of cis-resveratrol.


2017 ◽  
Vol 9 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Haddadi Azam ◽  
Somayeh Mikaili Ghezeljeh ◽  
Shavandi Mahmoud

Abstract Background Multidrug resistance is a serious problem in the treatment of urinary tract infections. Horizontal gene transfer, directed by strong selective pressure of antibiotics, has resulted in the widespread distribution of multiple antibiotic resistance genes. The dissemination of resistance genes is enhanced when they are trapped in integrons. Objectives To determine the prevalence of integrons among multidrug resistant Escherichia coli strains collected from regional hospitals and private clinical laboratories in Alborz province. Methods The susceptibility of 111 clinical Escherichia coli isolates was tested using a Kirby–Bauer disk diffusion method for common antibiotics. Isolates were screened for the production of extended spectrum β-lactamases (ESBLs) using a double disk synergy test. The existence of integrons was confirmed by amplification of the integrase gene and their class determined via analysis of PCR products by PCR-RFLP. Results Isolates showed the highest resistance to amoxicillin. Nitrofurantoin, amikacin, and ceftizoxime were the most effective antibiotics in vitro. Eighty-eight isolates of 111 (79%) were resistant to more than three unrelated drugs. We found 30% of the multidrug resistant isolates harbor integrons. Class 1 and 2 integrons were detected in 25 and 1 isolates, respectively. ESBL screening of strains showed 45 isolates (40%) were positive; 22% of the ESBL-positive isolates carried class 1 integrons and the frequency of MDR in ESBLpositive isolates was 93%. Conclusion The existence of integrons in only 29.5% of multidrug resistant isolates showed that besides integrons, antibiotic resistance genes were probably carried on other transferable elements lacking integrons, such as transposons or plasmids.


Sign in / Sign up

Export Citation Format

Share Document