scholarly journals Antimicrobial Susceptibility Testing of Metronidazole and Clindamycin against Gardnerella vaginalis in Planktonic and Biofilm Formation

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Ting Li ◽  
Zhan Zhang ◽  
Fengjuan Wang ◽  
Yuanhui He ◽  
Xiaonan Zong ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Resistance Rate ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Isolates ◽  
Lower Resistance ◽  
Antimicrobial Susceptibilities ◽  
Susceptibility Rate

Background. Bacterial vaginosis (BV), one of the most common vaginal ecosystem-related microbiologic syndromes, is the most common disorder in women of reproductive age. Gardnerella (G.) vaginalis is the predominant species causing this infection. Our aim was to compare the antimicrobial susceptibilities of metronidazole and clindamycin against G. vaginalis at planktonic and biofilm levels. Methods. From September 2019 to October 2019, we recruited a total of 10 patients with BV who underwent gynecological examinations at Beijing Obstetrics and Gynecology Hospital. G. vaginalis isolates were obtained from the vagina and identified using their characteristic colony morphology. Sequence data of clinical G. vaginalis isolates were confirmed by comparing 16S rDNA sequences. Subsequently, clinical isolates were evaluated for antimicrobial susceptibilities in vitro to metronidazole and clindamycin at planktonic and biofilm levels. The minimum inhibitory concentration (MIC) for metronidazole and clindamycin was evaluated by antimicrobial susceptibility testing. The minimum biofilm eradication concentration (MBEC) was evaluated by the biofilm inhibition assay. Results. Planktonic clinical isolates showed a significantly higher susceptibility rate (76.67%) and lower resistance rate (23.33%) to clindamycin than to metronidazole (susceptibility rate: 38.24%; resistance rate: 58.82%; P<0.05 for both). Furthermore, in comparison to planktonic isolates, the minimum inhibitory concentration (MIC) of metronidazole was significantly higher for biofilm-forming isolates (7.3 ± 2.6 μg/mL vs. 72.4 ± 18.3 μg/mL; P=0.005); the resistance rate was 27.3%, and the minimum biofilm eradication concentration (MBEC) was >128 μg/mL. Moreover, the MIC of clindamycin was higher too for biofilm-forming isolates (0.099 ± 0.041 μg/mL vs. 23.7 ± 9.49 μg/mL; P=0.034); the resistance rate was 27.3%, and the MBEC of clindamycin was 28.4 ± 6.50 μg/mL. Conclusion. Our results indicate that in comparison to metronidazole, clindamycin seems to be a better choice to tackle G. vaginalis as it exhibits a relatively higher susceptibility rate and lower resistance rate.

scholarly journals Renaissance of Conventional First-Line Antibiotics inSalmonella entericaClinical Isolates: Assessment of MICs for Therapeutic Antimicrobials in Enteric Fever Cases from Nepal

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Puspa Raj Khanal ◽  
Deepa Satyal ◽  
Anjeela Bhetwal ◽  
Anjila Maharjan ◽  
Shreena Shakya ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Blood Samples

Enteric fever caused bySalmonella entericais a life-threatening systemic illness of gastrointestinal tract especially in tropical countries. Antimicrobial therapy is generally indicated but resistance towards commonly used antibiotics has limited their therapeutic usefulness. Therefore, we aimed to determine the antimicrobial susceptibility pattern by minimum inhibitory concentration method of common therapeutic regimens againstSalmonella entericafrom enteric fever clinical cases.Salmonella entericaclinical isolates recovered from the patients with suspected enteric fever whose blood samples were submitted to microbiology laboratory of Manmohan Memorial Community Hospital, Kathmandu, from March 2016 to August 2016, were studied. These isolates were subjected to antimicrobial susceptibility testing against common therapeutic antimicrobials by Kirby-Bauer disk diffusion method. The minimum inhibitory concentration of ciprofloxacin, azithromycin, chloramphenicol, and cefixime was determined by Agar dilution method based on the latest CLSI protocol. A total of 88 isolates ofSalmonella entericawere recovered from blood samples of enteric fever cases. Out of them, 74 (84.09%) wereSalmonellaTyphi and 14 (15.91%) wereSalmonellaParatyphi A. On Kirby-Bauer disk diffusion antimicrobial susceptibility testing, entire isolates were susceptible to cotrimoxazole, cefixime, ceftriaxone, azithromycin, and chloramphenicol. Sixty-four (72.7%)Salmonella entericaisolates were nalidixic acid resistant and nonsusceptible to ciprofloxacin and levofloxacin. On MIC determination, fourSalmonellaisolates were ciprofloxacin resistant with MIC 1 µg/ml and two isolates were ciprofloxacin intermediate with MIC 0.5 µg/ml. The MIC range of azithromycin was from 0.125 µg/ml to 2.0 µg/ml, whereas that for chloramphenicol was 2.0 µg/ml–8.0 µg/ml and for cefixime was 0.0075–0.5 µg/ml, respectively. Despite global surge of antimicrobial resistance amongSalmonella entericaclinical isolates, the level of drug resistance in our study was not so high. However, higher level of NARST strains limits therapeutic use of fluoroquinolones and necessitates the routine monitoring of such resistance determinants in order to effectively and rationally manage enteric fever cases.

An automated and portable antimicrobial susceptibility testing system for urinary tract infections

Lab on a Chip ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 755-763
Author(s):  
Kuo-Wei Hsu ◽  
Wen-Bin Lee ◽  
Huey-Ling You ◽  
Mel S. Lee ◽  
Gwo-Bin Lee
Keyword(s):  
Urinary Tract ◽  
Minimum Inhibitory Concentration ◽  
Urinary Tract Infections ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Microfluidic System ◽  
Antimicrobial Susceptibility Testing ◽  
Testing System ◽  
Tract Infections

A portable, integrated microfluidic system capable of automatically conducting antimicrobial susceptibility testing (AST) and minimum inhibitory concentration (MIC) measurements using urine samples were developed.

A multiplexed nanoliter array-based microfluidic platform for quick, automatic antimicrobial susceptibility testing

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Mohammad Osaid ◽  
Yi-Sin Chen ◽  
Chih-Hung Wang ◽  
Anirban Sinha ◽  
Wen-Bin Lee ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Antimicrobial Susceptibility Testing ◽  
Bacterial Cells ◽  
Microfluidic Platform

A nanoliter array-based automatic microfluidic platform for performing rapid antimicrobial susceptibility testing using only ∼2000 bacterial cells was reported, and required 8–9 hours to determine the minimum inhibitory concentration value.

scholarly journals Susceptibility profile of Brazilian Rhodococcus equi isolates against azithromycin, clarithromycin and erythromycin

2015 ◽  
Vol 45 (4) ◽  
pp. 680-683
Author(s):  
Letícia Trevisan Gressler ◽  
Bibiana Petri da Silveira ◽  
Marcelo Luís Schwab ◽  
Agueda Castagna de Vargas ◽  
Luciana Pötter ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Rhodococcus Equi ◽  
Antimicrobial Susceptibility Testing ◽  
Microbiological Culture ◽  
Infection Treatment

Rhodococcus equi infection treatment is usually a macrolide (azithromycin - AZM, clarithromycin - CLR and erythromycin - ERY) and rifampicin combination. However, resistance cases have been reported, especially for ERY. In view of the need of a study about Brazilian isolates susceptibility profile, this study aimed to characterize the minimum inhibitory concentration (MIC) of the macrolides - AZM, CLR and ERY - against 44 R. equi isolates. It was found all isolates CLR and AZM sensitive; however, for ERY, 27% (12/44) were classified as intermediate sensitivity. R. equi Brazilian isolates used here showed a large susceptibility profile, except against ERY, for which it was observed some resistance evidence. In order to avoid failures in the equine rhodococcosis therapy it was highlighted the importance of microbiological culture and antimicrobial susceptibility testing in vitro before beginning treatment

scholarly journals Antimicrobial Susceptibilities of Clinical Isolates of HACEK Organisms

2013 ◽  
Vol 57 (4) ◽  
pp. 1989-1991 ◽  
Author(s):  
Bryan Coburn ◽  
Baldwin Toye ◽  
Prasad Rawte ◽  
Frances B. Jamieson ◽  
David J. Farrell ◽  
...  
Keyword(s):  
Infective Endocarditis ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Isolates ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Antimicrobial Susceptibilities

ABSTRACTThe “HACEK” organisms are a group of fastidious Gram-negative bacteria that cause a variety of infections, including infective endocarditis. Antimicrobial susceptibility testing is not universally available, and therapy for these infections is often empirical. We report the antimicrobial susceptibilities of 70 clinical HACEK isolates to 18 antimicrobials. All isolates were susceptible to ceftriaxone and levofloxacin, indicating that these agents remain appropriate empirical choices for the treatment of infections with this group of organisms.

scholarly journals Detection of Antibiotic Susceptibility by Colorimetric Minimum Inhibitory Concentration in Staphylococcal Isolates

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
B S Mahmoud ◽  
S A ElMasry ◽  
N A Fahim ◽  
O A Shaker ◽  
M A Abdelsattar
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Antimicrobial Susceptibility Testing ◽  
Bacterial Concentration ◽  
Tetrazolium Chloride ◽  
Wide Range ◽  
Agar Dilution

Abstract Background Staphylococcus species are implicated in a wide range of community and hospital-acquired infections, which necessitates rapid provision of antibiotic susceptibility results for patients at risk. The current study evaluated the usefulness of applying broth microdilution (BMD) and agar dilution methods for antimicrobial susceptibility testing of Staphylococci using tetrazolium salts as redox indicators. Methods Minimum inhibitory concentration (MICs) of eight antimicrobials representing different antibiotic classes as recommended by CLSI; vancomycin (VA), linezolid (LZD), oxacillin (OX), gentamicin (CN), tetracycline (TE), ciprofloxacin (CIP), erythromycin (E) and clindamycin (DA) was investigated for 80 isolates of Staphylococci by a modified BMD with the addition of dimethyl thiazole diphenyl tetrazolium bromide (MTT). As well as agar dilution with the addition of MTT & triphenyl tetrazolium chloride (TTC) at the standard bacterial concentration together with addition of MTT at an experimental bacterial concentration. Results BMD (MTT) showed the highest agreement regarding most antibiotics among different isolates in comparison with the standard BMD. All performed methods showed significant agreement except agar dilution (TTC) using TE, DA, E, and agar dilution (MTT 108) using DA as well as agar dilution (MTT 104) using E among S. aureus. Conclusions Colorimetric BMD was rapid, easy to interpret and showed the highest agreement with the standard BMD. Colorimetric agar dilution (MTT) was less tedious than BMD. The colorimetric MIC method using MTT may be a useful surrogate of antimicrobial susceptibility testing among Staphylococcus isolates.

scholarly journals Antibiotic Resistance Prevalence and Trends in Patients Infected with Helicobacter pylori in the Period 2013–2020: Results of the European Registry on H. pylori Management (Hp-EuReg)

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1058
Author(s):  
Luis Bujanda ◽  
Olga P. Nyssen ◽  
Dino Vaira ◽  
Ilaria M. Saracino ◽  
Giulia Fiorini ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antibiotic Resistance ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Resistance Rate ◽  
Antimicrobial Susceptibility Testing ◽  
Metronidazole Resistance ◽  
Infected Adult ◽  
H Pylori ◽  
European Registry

Background: Bacterial antibiotic resistance changes over time depending on multiple factors; therefore, it is essential to monitor the susceptibility trends to reduce the resistance impact on the effectiveness of various treatments. Objective: To conduct a time-trend analysis of Helicobacter pylori resistance to antibiotics in Europe. Methods: The international prospective European Registry on Helicobacter pylori Management (Hp-EuReg) collected data on all infected adult patients diagnosed with culture and antimicrobial susceptibility testing positive results that were registered at AEG-REDCap e-CRF until December 2020. Results: Overall, 41,562 patients were included in the Hp-EuReg. Culture and antimicrobial susceptibility testing were performed on gastric biopsies of 3974 (9.5%) patients, of whom 2852 (7%) were naive cases included for analysis. The number of positive cultures decreased by 35% from the period 2013–2016 to 2017–2020. Concerning naïve patients, no antibiotic resistance was found in 48% of the cases. The most frequent resistances were reported against metronidazole (30%), clarithromycin (25%), and levofloxacin (20%), whereas resistances to tetracycline and amoxicillin were below 1%. Dual and triple resistances were found in 13% and 6% of the cases, respectively. A decrease (p < 0.001) in the metronidazole resistance rate was observed between the 2013–2016 (33%) and 2017–2020 (24%) periods. Conclusion: Culture and antimicrobial susceptibility testing for Helicobacter pylori are scarcely performed (<10%) in Europe. In naïve patients, Helicobacter pylori resistance to clarithromycin remained above 15% throughout the period 2013–2020 and resistance to levofloxacin, as well as dual or triple resistances, were high. A progressive decrease in metronidazole resistance was observed.

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