scholarly journals Effect of Selected Antibiotics on Biofilm Formed by Salmonella Enterica Serovars Typhi and Paratyphi

2020 ◽  
Vol 37 (2) ◽  
pp. 62-65
Author(s):  
Israt Jahan Rini ◽  
Md Ariful Islam ◽  
Sunjukta Ahsan

Salmonella enterica serovars Typhi and Paratyphi are the causative agents of typhoid and paratyphoid, respectively, in human. Salmonella is able to form biofilms whereby members are resistant and persistent in both host and nonhost environments. In the present study the effect of the antibiotics, Azithromycin, Imipenem, Ceftriaxone and Cefixime, on planktonic and biofilm phase clinical isolates of Salmonella enterica serovars Typhi (n = 30) and Paratyphi A (n= 07) was investigated. MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) of planktonic phase bacteria were determined and compared with MRC (Minimum Re-growth Concentration) and MBEC (Minimum Biofilm Eradication Concentration) of biofilm population. The present study indicates that, with the exception of Azithromycin, a considerably higher concentration is needed for all other antibiotics investigated to inhibit growth of test isolates in the biofilm phase. We conclude that the requirement of Azithromycin at sub-MIC concentration to inhibit/kill Salmonella in biofilm is of particular significance in that it can be employed for the eradication of Salmonella spp. biofilms. Bangladesh J Microbiol, Volume 37 Number 2 December 2020, pp 62-65

Author(s):  
Dae Hun Kim ◽  
Su-Young Kim ◽  
Won-Jung Koh ◽  
Byung Woo Jhun

We evaluated the in vitro activities of oxazolidinone antibiotics including linezolid, sutezolid, and delpazolid against clinical nontuberculous mycobacteria isolates. Regardless of macrolide resistance, for M. avium, M. intracellulare, and M. kansasii, sutezolid showed the lowest minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) value among oxazolidinone antibiotics. However, for M. abscessus, M. massiliense, the MIC and MBC values for all oxazolidinone antibiotics showed similar values. Oxazolidinone antibiotics warrant further investigation as potential antibiotics.


2022 ◽  
Vol 82 ◽  
Author(s):  
N. Aslam ◽  
S. Hayat ◽  
T. Ali ◽  
M. Waseem ◽  
M. H. Siddique ◽  
...  

Abstract High resistance to antimicrobials is associated with biofilm formation responsible for infectious microbes to withstand severe conditions. Therefore, new alternatives are necessary as biofilm inhibitors to control infections. In this study, the antimicrobial and antibiofilm activities of Fagonia indica extracts were evaluated against MDR clinical isolates. The extract exhibited its antibiofilm effect by altering adherence and disintegration of bacterial cell wall. Fagonia indica has antibacterial effect as minimum inhibitory concentration (MIC) values ranging from 125 to 500 µg mL-1 and minimum bactericidal concentration (MBC) value was 500-3000 µg mL-1 against multidrug resistant (MDR) clinical isolates. The extract exhibited its antibiofilm effect by altering adherence and disintegration of bacterial cell wall. Fagonia indica had antibacterial effect as minimum inhibitory concentration (MIC) values ranging from 125 to 500 µg mL-1 and minimum bactericidal concentration (MBC) value was 500-3000 µg mL-1 against MDR isolates. The maximum inhibitory effects of Fagonia indica chloroform extract on biofilm formation was observed on Staphylococcus aureus (71.84%) followed by Klebsiella pneumoniae (70.83%) after 48 hrs showing that inhibition is also time dependent. Our results about bacterial cell protein leakage indicated that MDR isolates treated with chloroform extract of Fagonia indica showed maximum protein leakage of K. pneumoniae (59.14 µg mL-1) followed by S. aureus (56.7 µg mL-1). Cell attachment assays indicated that chloroform extract resulted in a 43.5-53.5% inhibition of cell adherence to a polystyrene surface. Our results revealed that extracts of Fagonia indica significantly inhibited biofilm formation among MDR clinical isolates, therefore, could be applied as antimicrobial agents and cost effective biofilm inhibitor against these MDR isolates.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Puspa Raj Khanal ◽  
Deepa Satyal ◽  
Anjeela Bhetwal ◽  
Anjila Maharjan ◽  
Shreena Shakya ◽  
...  

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.


2020 ◽  
Vol 21 (11) ◽  
pp. 1129-1137 ◽  
Author(s):  
Somayeh Mirsadeghi ◽  
Masoumeh F. Koudehi ◽  
Hamid R. Rajabi ◽  
Seied M. Pourmortazavi

Background: Herein, we report the biosynthesis procedure to prepare silver nanoparticles as reduction and capping agents with the aqueous plant extract of Perovskia abrotanoides. Methods: The therapeutic application of silver nanoparticles entirely depends on the size and shape of the nanoparticles therefore, their control during the synthesis procedure is so important. The effects of synthesis factors, for example, silver ion concentration, the mass of plant extract, reaction time and extraction temperature, on the size of silver particles were considered and optimized. Several analytical methods were used for the characterization of silver NPs including FT-IR and UV–Vis spectrophotometer, XRD and SEM. Results: The results showed that the mean size of the silver particles was about 51 nm. Moreover, the antibacterial properties of biosynthesized silver NPs were investigated by the minimum inhibitory concentration, minimum bactericidal concentration, and Well-diffusion tests. The minimum inhibitory concentration/ minimum bactericidal concentration values of silver NPs and aqueous plant extract versus Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (E. coli) were 3.03/0.00, 1.20/0.01, 3.06/0.00, 0.98/1.04, 1.00/0.05 and 1.30/0.03 (mg/mL), respectively. Conclusion: The antimicrobial activity study displayed that the synthesized silver nanoparticles by plant extract have better antimicrobial properties compared to aqueous plant extract of Perovskia abrotanoides.


Author(s):  
Khodijah Khodijah ◽  
Ratna Farida ◽  
Nurtami Soedarsono

Objective: This experiment aimed to analyze the effect of propolis extract and propolis containing candies on the growth of Aggregatibacter actinomycetemcomitans using spectrophotometric analysis and colony-forming units (CFU) counts.Methods: After A. actinomycetemcomitans were exposed to propolis extract and candies, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined with spectrophotometry and post-exposure colony counting.Results: The MIC of propolis extract against A. actinomycetemcomitans was determined to be 10%, and the MBC was 20%. A decrease in the total CFU count of A. actinomycetemcomitans was observed after propolis extract and candy exposure.Conclusions: Propolis extract and propolis candies were effective in inhibiting the growth of A. actinomycetemcomitans ATCC 43718 in vitro.


2013 ◽  
Vol 1 (1) ◽  
pp. 27-31
Author(s):  
Agustina Dwi Wijayanti ◽  
Antasiswa Windraningtyas Rosetyadewi ◽  
Tri Untari

Telah dilakukan penelitian tentang efektivitas antibiotika golongan fluoroquinolon (flumequin dan enrofloksasin) terhadap Salmonella dan E. coli yang diisolasi dari saluran pencernaan ular sanca batik (Python reticulatus). Penelitian ini bertujuan untuk mengetahui efektivitas fluoroquinolon terhadap infeksi saluran pencernaan pada ular dan reptil pada umumnya. Penelitian dilakukan dengan menggunakan 8 ekor sanca batik dewasa yang menderita gangguan pencernaan dengan lesi klinis berupa mouthrot. Sampel ulas kloaka dan mulut serta sampel darah diambil dari semua ular, untuk selanjutnya dilakukan uji mikrobiologis berupa isolasi dan identifikasi bakteri melalui media Brilliant Green Agar (BGA), Mc Conkay Agar (MCA), Triple Sugar Iron (TSI) dan media biakan murni. Isolat murni yang didapatkan adalah Salmonella spp. dan E. coli dan selanjutnya dilakukan uji sensitivitas bakteri terhadap flumequin dan enrofloksasin serta penentuan Minimum Inhibitory Concentration (MIC) untuk enrofloksasin. Hasilnya adalah kedua antibiotika efektif terhadap Salmonella dan intermediet terhadap E. coli. Nilai MIC enrofloksasin terhadap Salmonella adalah 2,5 μg/ml.


2020 ◽  
Vol 10 (2) ◽  
pp. 82
Author(s):  
Fatemeh Samieerad ◽  
Nematollah Gheibi

Background: Propolis is one of the useful bee colony products that have been used in traditional medicine for centuries. In this study, the physicochemical characters and their antibacterial effect of Iranian Propolis collected from Qazvin province was assessed.Methods: In this study, Thin Layer Chromatography and Vacuum Liquid Chromatography to detect different compounds of the extract have been used. In the initial evaluation of Propolis extract, it was found that the extract includes variable compounds with different polarity; so, the initial classification of extract with different polarity solvents was essential. Finally, 0.1 gr hydro alcoholic Propolis was injected to the HPLC by ultrasound. The antibacterial effect of Iranian ethanol extract Propolis was measured using a microdilution method against Pseudomonas aeruginosa: P. aeruginosa and Staphylococcus aureus: S.aureus standard strains and the minimum bactericidal and inhibitory concentration were defined.Results: Primary analysis of the ethanol extract by analytical Thin Layer Chromatography, demonstrated the presence of flavonoid and phenol in it. Minimum inhibitory concentration and Minimum Bactericidal Concentration for Staphylococcus aureus: S.aureus standard strain was 2.5mg/ml. The same procedure was done for Pseudomonas aeruginosa: P. aeruginosa standard strain and the Minimum inhibitory concentration and Minimum Bactericidal Concentration were 50mg/ml of Propolis extracts.  Conclusion: According to the results, the alcoholic extract of propolis from Qazvin province of Iran provides significant antimicrobial activity. Its powerful activity may be due to high total phenolic and flavonoid contents.Keywords: Iranian propolis, Antibacterial activity, Phenolic compounds, Flavonoid compound


PEDIATRICS ◽  
1980 ◽  
Vol 66 (2) ◽  
pp. 309-312
Author(s):  
Henry M. Feder ◽  
Neil Olsen ◽  
James C. Mclaughlin ◽  
Raymond C. Bartlett ◽  
Leon Chameides

Two cases of bacterial endocarditis in children, caused by viridans group Streptococcus which requires vitamin B6 or thiol compounds for growth are reported. It is important to recognize these organisms as a possible cause of endocarditis because supplemented media are needed for their isolation and sensitivity testing. These organisms may be penicillin-sensitive, -resistant, or -tolerant. An organism is considered tolerant to an antibiotic when the minimum bactericidal concentration of that antibiotic is ≥32 times the minimum inhibitory concentration. One of our patients relapsed when treated with a single antibiotic to which the B6-dependent viridans group Streptococcus was tolerant. If a B6-dependent viridans group Streptococcus is isolated from a patient with endocarditis, therapy should be initiated with penicillin and an aminoglycoside until sensitivities are available. Sensitity testing should include both the MIC and MBC and adequate therapy can be confirmed by determining the serum bactericidal activity.


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