scholarly journals In vitro efficacy of synergistic antibiotic combinations in imipenem resistant Pseudomonas aeruginosa strains

2017 ◽  
Vol 9 (1) ◽  
pp. 3-8
Author(s):  
Aleya Farzana ◽  
S. M. Shamsuzzaman
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Considerable Proportion ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
New Antibiotics

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

scholarly journals Occurrence of NDM-1 and VIM-2 Co-Producing Escherichia coli and OprD Alteration in Pseudomonas aeruginosa Isolated from Hospital Environment Samples in Northwestern Tunisia

Diagnostics ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1617
Author(s):  
Raouaa Maaroufi ◽  
Olfa Dziri ◽  
Linda Hadjadj ◽  
Seydina M. Diene ◽  
Jean-Marc Rolain ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Resistance ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Hospital Environment ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Disk Diffusion Method

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.

scholarly journals Antimicrobial Resistance in Salmonella Typhi Isolated From a Referral Hospital of Kathmandu, Nepal

2021 ◽  
Vol 14 ◽  
pp. 117863612110563
Author(s):  
Saroj Khadka ◽  
Basudha Shrestha ◽  
Anil Pokhrel ◽  
Sachin Khadka ◽  
Rajesh Dhoj Joshi ◽  
...  
Keyword(s):  
Typhoid Fever ◽  
Antibiotic Susceptibility ◽  
Large Scale ◽  
Salmonella Typhi ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
First Line ◽  
Disk Diffusion Method

Purpose: The morbidity and mortality due to typhoid fever can be significantly reduced with the use of effective antibiotics. At present, fluoroquinolones, third generation cephalosporins, and azithromycin are widely used to treat typhoid fever. However, changing antibiotic susceptibility among Salmonella Typhi and Salmonella Paratyphi poses a particular challenge to the therapeutic management of enteric fever. The objective of this study was to assess the antibiotic susceptibility pattern of Salmonella Typhi isolates. Patients and Methods: A total of 706 blood specimens were collected from febrile patients attending the outpatient department of Kathmandu Model Hospital during June to September, 2018. The antibiotic susceptibility testing for 11 different antibiotics (nalidixic acid, ciprofloxacin, ofloxacin, levofloxacin, cefixime, ceftriaxone, cefotaxime, azithromycin, cotrimoxazole, chloramphenicol, and amoxicillin) was performed by disk diffusion method. Furthermore, minimum inhibitory concentration (MIC) values of ciprofloxacin, ofloxacin, and azithromycin were determined by agar dilution method. Mutation at gyrA ser83 associated with reduced susceptibility to fluoroquinolones was determined by PCR-RFLP. Results: Out of 706 blood samples, 6.94% (n = 49) were culture positive for Salmonella enterica (S. Typhi, n = 46). It was revealed that 97.8% S. Typhi isolates were susceptible to conventional first-line antibiotics (ampicillin, chloramphenicol, and cotrimoxazole), 97.3% to cephalosporins and 95.7% to azithromycin. S. Typhi were either resistant or intermediately susceptible to fluoroquinolones: 97.8% to ciprofloxacin, 91.3% to ofloxacin, and 89.1% to levofloxacin. The MIC of ciprofloxacin, ofloxacin, and azithromycin for S. Typhi ranged from 0.008 to 32, 0.03 to 16, and 2 to 8 μg/mL, respectively. Out of 46 S. Typhi isolates, 44 (95.65%) had gyrA ser83 mutation. Conclusion: Fluoroquinolones have poor activity against Salmonella Typhi. The trends of increasing azithromycin MIC value among S. Typhi might limit its use for the treatment of typhoid fever. Effectiveness of conventional first-line antibiotics in vitro suggests considering their clinical use after large-scale studies.

scholarly journals Emergence and rising of ceftazidime-avibactam resistant KPC-producing Pseudomonas aeruginosa in China: a molecular epidemiology study

2020 ◽  
Author(s):  
Yiwei Zhu ◽  
Jie Chen ◽  
Han Shen ◽  
Zhongju Chen ◽  
Qiwen Yang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gene Copy Number ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Gene Copy ◽  
Molecular Characteristics ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Klebsiella Pneumoniae Carbapenemase ◽  
Broth Microdilution Method

Background: Infections by Carbapenem-resistant Pseudomonas aeruginosa (CRPA) are difficult to treat and novel antibiotics are desperately needed. Till today, ceftazidime-avibactam (CAZ-AVI) has been used to treat infections caused by multidrug resistant (MDR) Gram-negative bacteria, including Klebsiella pneumoniae carbapenemase (KPC)-producing organisms. Although cases of KPC-producing P. aeruginosa (KPC-PA) have been reported sporadically, data about KPC-PA susceptibility to CAZ-AVI and its molecular characteristics are limited. Methods: CRPA were collected from seven hospitals in China from 2017 to 2018. PCR was deployed to screen for the blaKPC gene. Antimicrobial susceptibility of KPC-PA was determined by broth microdilution method or agar dilution method. We combined Illumina sequencing and Nanopore long-read sequencing to elucidate the genomic characteristics of KPC-PA strains. Results: KPC-PA strains were found in six out of seven hospitals. 151/374 (40.4%) CRPA clinical isolates harbored the blaKPC-2 gene. Among KPC-PA, ST463 (107/151) was predominant, followed by ST485 (14/151) and ST1212 (12/151). Approximately half of all KPC-PA (50.3%) were susceptible to CAZ-AVI. We found that the blaKPC-2 gene copy number correlated with CAZ-AVI MIC. In more than 90% (136/151) of the strains, we found plasmids that belonged to two types carrying blaKPC-2 gene. The Type 1 plasmid, predominant in East China, was identified in 118 strains and the Type 2 plasmid, belonged to a megaplasmid family spreading globally, was identified in 19 strains. In addition, we identified IS26-ΔTn6296 and IS6100-ΔTn6296-Tn1403 as two mobile genetic elements that mediated blaKPC-2 gene transmission. Conclusion: Our results suggest that the blaKPC-2 gene is becoming a remarkable mediator of carbapenem resistance in P. aeruginosa in China. The emergence and spread of such KPC-PA strains poses a threat on clinical therapy as CAZ-AVI becomes inefficient. It would be beneficial to screen for the blaKPC gene in CRPA strains for antimicrobial surveillance.

Ginseng aqueous extract attenuates the production of virulence factors, stimulates twitching and adhesion, and eradicates biofilms of Pseudomonas aeruginosa

2011 ◽  
Vol 89 (6) ◽  
pp. 419-427 ◽  
Author(s):  
Misagh Alipour ◽  
Abdelwahab Omri ◽  
Zacharias E. Suntres
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Aqueous Extract ◽  
North American ◽  
American Ginseng ◽  
Antimicrobial Activities ◽  
Live Cells ◽  
Dilution Method ◽  
Agar Dilution Method

This study was carried out to examine the antimicrobial activity of the aqueous extract of Panax quinquefolius from North American ginseng (NAGE) root against Pseudomonas aeruginosa . The minimum inhibitory concentrations of reference and clinical isolates of Pseudomonas aeruginosa were measured by a standard agar-dilution method. At subinhibitory NAGE concentrations, the secretion of virulence factors, motility on agar, and adhesion to 96-well microplates were studied on the nonmucoid Pseudomonas aeruginosa O1 strain. At suprainhibitory concentrations, the activity of NAGE against mature biofilm complexes formed in the Calgary Biofilm Device and the Stovall flow cell were assessed. NAGE possessed an antibacterial activity against all the Pseudomonas aeruginosa strains at 1.25%–2.5% w/v. NAGE also significantly attenuated pyocyanin, pyoverdine, and lipase concentrations, stimulated twitching, and attenuated swarming and swimming motility. At 1.25% w/v, NAGE augmented adhesion, and at 5% w/v detached 1-day-old biofilms in microplates. The extract also eradicated 6-day-old mature biofilms (5% w/v), and fluorescence microscopy displayed a reduction of live cells and biofilm complexes compared with nontreated biofilms. These data suggest that the aqueous extract from North American ginseng possesses antimicrobial activities in vitro.

scholarly journals Essential Oil from Origanum vulgare Completely Inhibits the Growth of Multidrug-Resistant Cystic Fibrosis Pathogens

2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Giovanna Pesavento ◽  
Valentina Maggini ◽  
Isabel Maida ◽  
Antonella Lo Nostro ◽  
Carmela Calonico ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Essential Oil ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Achromobacter Xylosoxidans ◽  
Bacterial Strains ◽  
Origanum Vulgare ◽  
Disk Diffusion Method ◽  
Wide Range

Essential oils (EOs) are known to inhibit the growth of a wide range of microorganisms. Particularly interesting is the possible use of EOs to treat multidrug-resistant cystic fibrosis (CF) pathogens. We tested the essential oil (EO) from Origanum vulgare for in vitro antimicrobial activity, against three of the major human opportunistic pathogens responsible for respiratory infections in CF patients; these are methicillin-resistant Staphylococcus aureus, Stenotrophomonas maltophilia and Achromobacter xylosoxidans. Antibiotic susceptibility of each strain was previously tested by the standard disk diffusion method. Most strains were resistant to multiple antibiotics and could be defined as multi-drug-resistant (MDR). The antibacterial activity of O. vulgare EO (OEO) against a panel of 59 bacterial strains was evaluated, with MIC and MBC determined at 24, 48 and 72 hours by a microdilution method. The OEO was effective against all tested strains, although to a different extent. The MBC and MIC of OEO for S. aureus strains were either lower or equal to 0.50%, v/v, for A. xylosoxidans strains were lower or equal to 1% and 0.50%, v/v, respectively; and for S. maltophilia strains were lower or equal to 0.25%, v/v. The results from this study suggest that OEO might exert a role as an antimicrobial in the treatment of CF infections.

scholarly journals Comparison of methods for the determination of antimicrobial resistance in Campylobacter spp. human and the food chain isolates

2008 ◽  
Vol 52 (No. 4) ◽  
pp. 169-174
Author(s):  
M. Holasova ◽  
R. Karpiskova ◽  
S. Karpiskova ◽  
V. Babak ◽  
J. Schlegelova
Keyword(s):  
Nalidixic Acid ◽  
Antimicrobial Agents ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Study Results ◽  
Agar Dilution

With a microdilution method, using the commercial diagnostic test Sensititre Susceptibility Plates for Campylobacter MIC (Trek Diagnostic Systems, Cleveland, OH, USA), disk diffusion and agar dilution method, resistance to six antimicrobial agents were examined in a reference strain <i>Campylobacter jejuni</i> ATCC 33560 and 73 thermo-tolerant isolates of <i>Campylobacter</i> spp. For the microdilution method and all tested antimicrobial agents, our determined values of microbiological breakpoints of resistant strains were suggested as the minimum inhibitory concentration (MIC<sub>R</sub>) for ciprofloxacin &ge; 0.5, erythromycin &ge; 4, gentamicin &ge; 4, nalidixic acid &ge; 32 and tetracycline &ge; 4 &mu;g/ml. On the basis of our study results, strains resistant to clindamycin were MIC<sub>R</sub> &ge; 2 &mu;g/ml for the dilution methods and a zone diameter R ≤ 16 mm for the disk diffusion method. Comparison of the results of the resistance examination, a microdilution method and disk diffusion method with the reference agar dilution method, showed that all compared methods yielded identical results with the exception of the resistance determination in erythromycin and nalidixic acid. The errors were mostly the result of the interpretation criteria for MIC<sub>R</sub> of agar dilution method and different conditions of cultivation used. However, the compared methods, provide results comparable with the reference method having greater convenience of measurement.

scholarly journals USING ESSENTIAL OILS TO COMBAT THE THREAT OF MULTI-DRUG RESISTANT BACTERIA, PSEUDOMONAS AERUGINOSA

2016 ◽  
Vol 8 (12) ◽  
pp. 180 ◽  
Author(s):  
Jenies Grullon ◽  
James P. Mack ◽  
Albert Rojtman
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Essential Oils ◽  
Alternative Treatment ◽  
Scientific Discovery ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Human Beings ◽  
Disk Diffusion Method ◽  
Cinnamon Bark

<div class="WordSection1"><p><strong>Objective: </strong>The development of antibiotics was a revolutionary scientific discovery and medical advancement that greatly extended the life expectancy of mankind. Through less than 100 y of using antibiotics to treat infectious bacteria, some of these highly adaptive organisms have developed resistance to the drugs. The healthcare field is greatly concerned with the threat of many common infections that have been considered treatable for decades, regaining its ability to be severely fatal; thus, making alternative treatments currently in high demand. This study concentrated on investigating an alternative treatment for a specific gram-negative bacterium, <em>Pseudomonas aeruginosa (P. aeruginosa)</em>, a resistance-gaining bacteria that commonly infects hospitalized patients with weakened immune systems and/or open wounds.</p><p><strong>Methods: </strong>Prior to the age of modern medicine, human beings relied on nature for medicinal treatments. In our research, we focused on determining the <em>in vitro </em>efficacy of using the essential oils, cassia and cinnamon bark, their major component, cinnamaldehyde, as well as the major component of manuka honey, methylglyoxal, as an alternative treatment against <em>P. aeruginosa</em> We tested cassia, cinnamon bark, cinnamaldehyde, and methylglyoxal using the Kirby-Bauer disk diffusion method; the diameter of the zone of inhibition for each treated bacterial sample was measured and compared with the standard antibiotic treatments, tobramycin, and amikacin.</p><p><strong>Results: </strong>This study showed that the selected essential oils, cinnamaldehyde, and methylglyoxal were as effective or better in inhibiting the growth of <em>P. aeruginosa </em>compared to the standard aminoglycoside antibiotics.</p><p><strong>Conclusion: </strong>The tested essential oils, cinnamaldehyde, and methylglyoxal may be useful as an alternative treatment for infections caused by <em>P. aeruginosa</em> and may also provide communities where antibiotics are not readily available, a cost-effective way to treat this infectious disease.</p></div>

scholarly journals Inaccuracy of the Disk Diffusion Method Compared with the Agar Dilution Method for Susceptibility Testing of Campylobacter spp.

2011 ◽  
Vol 50 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Mirva Lehtopolku ◽  
Pirkko Kotilainen ◽  
Pauli Puukka ◽  
Ulla-Maija Nakari ◽  
Anja Siitonen ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Agar Dilution ◽  
Campylobacter Spp

scholarly journals Phenotypic and genotypic characterization of multidrug-resistant isolates from patients with catheter-associated urinary tract infection in a tertiary care hospital

2019 ◽  
Vol 11 (03) ◽  
pp. 206-211
Author(s):  
Jaison Jayakaran ◽  
Nirupa Soundararajan ◽  
Priyadarshini Shanmugam
Keyword(s):  
Urinary Tract ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Care Hospital ◽  
Disk Diffusion Method ◽  
Carbapenem Resistant ◽  
Tract Infections

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.

Sign in / Sign up

Export Citation Format

Share Document