scholarly journals In vitro Development of Resistance to Azithromycin in Pseudomonas aeruginosa

2018 ◽  
Vol 21 (1) ◽  
pp. 42-46
Author(s):  
Thanmin Jarana Thammi ◽  
Md Masud Rana ◽  
Farhanur Rahman ◽  
Apu Banik ◽  
Md Anwar Ul Islam

Antimicrobial resistance has been considered as a growing public health problem all over the world. Due to improper use of antibiotics many bacterial species including the Pseudomonas aeruginosa become resistant. So, the objectives of this study were to determine the success or failure of antibiotic therapy. Tests were performed in vitro and measured the growth response of an isolated bacterium to a particular drug. This study determined the zone of inhibition, minimum inhibitory concentration (MIC) and time at which bacteria showed resistance. From sensitivity test, it showed that P. aeruginosa is sensitive to azithromycin antibiotic. MIC level of P. aeruginosa that was found from the analysis was 3 μg/ml and from further analysis it was found that P. aeruginosa grew resistance when it got up to 2.5 μg/ml concentration of antibiotic below MIC level for 24 hours. When the P. aeruginosa was treated with the concentration upto 2.5 μg/ml for 24 hours then it showed growth at the concentration of MIC level. It means that P. aeruginosa got the drug below MIC level for a certain period and became resistant to azithromycin.Bangladesh Pharmaceutical Journal 21(1): 42-46, 2018

2001 ◽  
Vol 7 (3) ◽  
pp. 144-151 ◽  
Author(s):  
H. Carsenti-Etesse ◽  
J.D. Cavallo ◽  
P.M. Roger ◽  
I. Ziha-Zarifi ◽  
P. Plesiat ◽  
...  

2001 ◽  
Vol 45 (12) ◽  
pp. 3422-3426 ◽  
Author(s):  
Siddhartha Roychoudhury ◽  
Tracy L. Twinem ◽  
Kelly M. Makin ◽  
Mark A. Nienaber ◽  
Chuiying Li ◽  
...  

ABSTRACT The in vitro development of resistance to the new nonfluorinated quinolones (NFQs; PGE 9262932, PGE 4175997, and PGE 9509924) was investigated in Staphylococcus aureus. At concentrations two times the MIC, step 1 mutants were isolated more frequently with ciprofloxacin and trovafloxacin (9.1 × 10−8 and 5.7 × 10−9, respectively) than with the NFQs, gatifloxacin, or clinafloxacin (<5.7 × 10−10). Step 2 and step 3 mutants were selected via exposure of a step 1 mutant (selected with trovafloxacin) to four times the MICs of trovafloxacin and PGE 9262932. The step 1 mutant contained the known Ser80-Phe mutation in GrlA, and the step 2 and step 3 mutants contained the known Ser80-Phe and Ser84-Leu mutations in GrlA and GyrA, respectively. Compared to ciprofloxacin, the NFQs were 8-fold more potent against the parent and 16- to 128-fold more potent against the step 3 mutants. Mutants with high-level NFQ resistance (MIC, 32 μg/ml) were isolated by the spiral plater-based serial passage technique. DNA sequence analysis of three such mutants revealed the following mutations: (i) Ser84-Leu in GyrA and Glu84-Lys and His103-Tyr in GrlA; (ii) Ser-84Leu in GyrA, Ser52-Arg in GrlA, and Glu472-Val in GrlB; and (iii) Ser84-Leu in GyrA, Glu477-Val in GyrB, and Glu84-Lys and His103-Tyr in GrlA. Addition of the efflux pump inhibitor reserpine (10 μg/ml) resulted in 4- to 16-fold increases in the potencies of the NFQs against these mutants, whereas it resulted in 2-fold increases in the potencies of the NFQs against the parent.


2007 ◽  
Vol 51 (10) ◽  
pp. 3642-3649 ◽  
Author(s):  
Beate Henrichfreise ◽  
Irith Wiegand ◽  
Ingeborg Luhmer-Becker ◽  
Bernd Wiedemann

ABSTRACT In this study we investigated the interplay of antibiotic pharmacokinetic profiles and the development of mutation-mediated resistance in wild-type and hypermutable Pseudomonas aeruginosa strains. We used in vitro models simulating profiles of the commonly used therapeutic drugs meropenem and ceftazidime, two agents with high levels of antipseudomonal activity said to have different potentials for stimulating resistance development. During ceftazidime treatment of the wild-type strain (PAO1), fully resistant mutants overproducing AmpC were selected rapidly and they completely replaced wild-type cells in the population. During treatment with meropenem, mutants of PAO1 were not selected as rapidly and showed only intermediate resistance due to the loss of OprD. These mutants also replaced the parent strain in the population. During the treatment of the mutator P. aeruginosa strain with meropenem, the slowly selected mutants did not accumulate several resistance mechanisms but only lost OprD and did not completely replace the parent strain in the population. Our results indicate that the commonly used dosing regimens for meropenem and ceftazidime cannot avoid the selection of mutants of wild-type and hypermutable P. aeruginosa strains. For the treatment outcome, including the prevention of resistance development, it would be beneficial for the antibiotic concentration to remain above the mutant prevention concentration for a longer period of time than it does in present regimens.


2021 ◽  
Author(s):  
Natalie Lindgren ◽  
Lea Novak ◽  
Benjamin C. Hunt ◽  
Melissa S. McDaniel ◽  
W. Edward Swords

Patients with cystic fibrosis (CF) experience lifelong respiratory infections which are a significant cause of morbidity and mortality. These infections are polymicrobial in nature, and the predominant bacterial species undergo a predictable series of changes as patients age. Young patients have populations dominated by opportunists that are typically found within the microbiome of the human nasopharynx, such as nontypeable Haemophilus influenzae (NTHi); these are eventually supplanted and the population within the CF lung is later dominated by pathogens such as Pseudomonas aeruginosa ( Pa ). In this study, we investigated how initial colonization with NTHi impacts colonization and persistence of Pa in the respiratory tract. Analysis of polymicrobial biofilms in vitro by confocal microscopy revealed that NTHi promoted greater levels of Pa biofilm volume and diffusion. However, sequential respiratory infection of mice with NTHi followed by Pa resulted in significantly lower Pa as compared to infection with Pa alone. Coinfected mice also had reduced airway tissue damage and lower levels of inflammatory cytokines as compared with Pa infected mice. Similar results were observed after instillation of heat-inactivated NTHi bacteria or purified NTHi lipooligosaccharide (LOS) endotoxin prior to Pa introduction. Based on these results, we conclude that NTHi significantly reduces susceptibility to subsequent Pa infection, most likely due to priming of host innate immunity rather than a direct competitive interaction between species. These findings have potential significance with regard to therapeutic management of early life infections in patients with CF.


2012 ◽  
Vol 48 (4) ◽  
pp. 691-698
Author(s):  
Carolina Alves dos Santos ◽  
Laura Oliveira-Nascimento ◽  
Marcos Camargo Knirsch ◽  
Marco Antônio Stephano ◽  
Adalberto Pessoa Júnior ◽  
...  

Ceftazidime is a broad spectrum antibiotic administered mainly by the parenteral route, and it is especially effective against Pseudomonas aeruginosa. The period of time in which serum levels exceed the Minimum Inhibitory Concentration (MIC) is an important pharmacodynamic parameter for its efficacy. One of the forms to extend this period is to administer the antibiotic by continuous infusion, after prior dilution in a Parenteral Solution (PS). The present work assessed the stability of ceftazidime in 5% glucose PS for 24 hours, combined or not with aminophylline, through High Performance Liquid Chromatography (HPLC). The physicochemical evaluation was accompanied by in vitro antimicrobial activity compared MIC test in the 24-hour period. Escherichia coli and Pseudomonas aeruginosa were the microorganisms chosen for the MIC comparison. The HPLC analysis confirmed ceftazidime and aminophylline individual stability on PS, while the MIC values were slightly higher than the mean described in the literature. When both drugs were associated in the same PS, the ceftazidime concentration by HPLC decreased 25% after 24 hours. Not only did the MIC values show high loss of antibiotic activity within the same period, but also altered MIC values immediately after the preparation, which was not detected by HPLC. Our results indicate that this drug combination is not compatible, even if used right away, and that PS might not be the best vehicle for ceftazidime, emphasizing the importance of the MIC evaluation for drug interactions.


Author(s):  
TITTY SULIANTI ◽  
NILAKESUMA DJAUHARI ◽  
BAMBANG NURSASONGKO

Objective: The aim is to compare the antimicrobial effects of papain and Papacarie with dilution and diffusion tests.Methods: There were two treatment groups and one Group control. The treatment group received papain and Papacarie, and the control groupreceived chlorhexidine, in five liquids with different concentrations of 0.5%, 0.25%, 0.125%, 0.0625%, and 0.03%. The dilution and diffusion testswere used to determine the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and zone of inhibition for eachtreatment material.Results: MICs of papain and Papacarie were 12.5%, indicating that at a concentration of 12.5%, the material can inhibit the growth of Streptococcusmutans. Papain does not have an MBC value but the Papacarie has an MBC at 25%, which indicating that at a concentration of 25%, Papacarie hasbactericidal effects on S. mutans. The zone of inhibition of papain was lower than Papacarie.Conclusion: Based on chemomechanical caries removal materials, the antimicrobial effects of Papacarie were better than those of papain.


2019 ◽  
Vol 10 (2) ◽  
pp. 1049-1053 ◽  
Author(s):  
Geetha RV ◽  
John Rozar Raj B ◽  
Lakshmi Thangavelu

To conduct a study regarding the antibacterial activity of essential oils against bacteria causing Caries. Essential oils are distillates of the volatile compounds of a plant’s secondary metabolism and may act as photoprotective agents. Their curative effect has been known since antiquity. It is based on a variety of pharmacological properties which are specific for each plant species. The mouth contains a variety of oral bacteria, but only a few species of bacteria are believed to cause dental caries. Antibacterial activity of the three essential oils, Rosemary oil, Holy basil oil, Thyme oil was screened against Streptococcus mutans, using disc diffusion technique. The rosemary oil was more effective against Streptococcus mutans with a zone of inhibition of 52 mm diameter (at concentration 200 µl), Rosemary oil showed a zone of inhibition of 44 mm diameter and with thyme oil, the zone diameter was 30 mm. The results of this study showed that the essential oils at different concentrations exhibited antibacterial activity against the bacterial species tested.


2000 ◽  
Vol 44 (2) ◽  
pp. 414-417 ◽  
Author(s):  
Todd A. Davies ◽  
Bonifacio E. Dewasse ◽  
Michael R. Jacobs ◽  
Peter C. Appelbaum

ABSTRACT The ability of 50 sequential subcultures in subinhibitory concentrations of telithromycin (HMR 3647), azithromycin, clarithromycin, erythromycin A, roxithromycin, clindamycin, and pristinamycin to select for resistance was studied in five macrolide-susceptible and six macrolide-resistant pneumococci containing mefE or ermB. Telithromycin selected for resistance less often than the other drugs.


Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2464
Author(s):  
Ramiro Quintanilla-Licea ◽  
Javier Vargas-Villarreal ◽  
María Julia Verde-Star ◽  
Verónica Mayela Rivas-Galindo ◽  
Ángel David Torres-Hernández

Amebiasis caused by Entamoeba histolytica is nowadays a serious public health problem worldwide, especially in developing countries. Annually, up to 100,000 deaths occur across the world. Due to the resistance that pathogenic protozoa exhibit against commercial antiprotozoal drugs, a growing emphasis has been placed on plants used in traditional medicine to discover new antiparasitics. Previously, we reported the in vitro antiamoebic activity of a methanolic extract of Lippia graveolens Kunth (Mexican oregano). In this study, we outline the isolation and structure elucidation of antiamoebic compounds occurring in this plant. The subsequent work-up of this methanol extract by bioguided isolation using several chromatographic techniques yielded the flavonoids pinocembrin (1), sakuranetin (2), cirsimaritin (3), and naringenin (4). Structural elucidation of the isolated compounds was achieved by spectroscopic/spectrometric analyses and comparing literature data. These compounds revealed significant antiprotozoal activity against E. histolytica trophozoites using in vitro tests, showing a 50% inhibitory concentration (IC50) ranging from 28 to 154 µg/mL. Amebicide activity of sakuranetin and cirsimaritin is reported for the first time in this study. These research data may help to corroborate the use of this plant in traditional Mexican medicine for the treatment of dyspepsia.


Sign in / Sign up

Export Citation Format

Share Document