scholarly journals In Vitro Susceptibility of Neisseria gonorrhoeae to Spectinomycin Examined by a Broth Dilution Method

1973 ◽  
Vol 3 (3) ◽  
pp. 335-337 ◽  
Author(s):  
J. Levy ◽  
K. Wicher ◽  
N. R. Rose
Author(s):  
Aseel Alsarahni ◽  
Zuhair Muhi Eldeen ◽  
Elham Al-kaissi ◽  
Hiba Al-malliti

Objective: To determine the time needed for killing different types of microorganisms by a newly synthesized 2-mercapto-1,3-benzothiazole derivative in comparison to ciprofloxacin and fluconazole.Methods: The minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) for 2-{[4-(2,6-dimethylPiperidin-1-yl)but-2-yn-1-yl]Sulfanyl}-1,3-benzothiazole(AZ3) compound were determined, using the broth dilution method. The MBC and MFC dilutions were prepared. Broth cultures of Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) were incubated at 37 °C for 24 h, and Candida albicans (C. albicans) was incubated at 25 °C for 48 h. 0.1 ml of each broth culture represent 1.5 x 106 CFU/ml was challenged with 9.9 ml broth containing the MBC or MFC concentrations of the AZ3 compound. From each sample at different time intervals, 1 ml was taken and added to 9 ml of sterile distilled water, in order to neutralize the effect of AZ3. Serial dilution was done and a viable count was determined from the appropriate dilutions.Results: The viability of the P. aeruginosa, E. coli, S. aureus, B. subtilis and C. albicans were killed within 3.5 h, 5 h, 24 h, 3 h and 5 h respectively. The time killing curves showed that AZ3 needed longer time for killing S. aureus than the time needed to kill B. subtilis. On the other hand, AZ3 needed a shorter time to kill P. aeruginosa, than the time needed to kill E. coli. In comparison with ciprofloxacin, AZ3 needed a shorter time to kill P. aeruginosa and E. coli, and the same time to kill B. subtilis, while it needed longer time than ciprofloxacin to kill S. aureus. In comparison with fluconazole, AZ3 with lower MFC than fluconazole needed longer time to kill C. albicans.Conclusion: AZ3 showed promising antimicrobial killing activities, in compared with ciprofloxacin and fluconazole, which promoted our interest to investigate the time of killing needed for other 2-mercaptobenzothiazole derivatives against different types of microorganisms.


Author(s):  
Kumar Kamashi ◽  
Mr. Honnegowda ◽  
Mayanna Asha ◽  
Chandrakala Ms.

Antimicrobial resistance is a growing concern worldwide. The indiscriminate use of antibiotics for a period of time has led to the emergence of antibiotic resistance in pathogenic bacteria. The present study was designed to evaluate the antibacterial efficacy of fluoroquinolone drugs, ciprofloxacin, enrofloxacin, moxifloxacin, sparfloxacin, norfloxacin, pefloxacin and ofloxacin against avian Salmonella gallinarum bacterial biofilms. The study parameters, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and biofilm elimination concentration (BEC) were determined on days 1, 3, 7, 10, 14 and 20 post inoculation for the planktonic (free) and biofilm cells of S. gallinarum by macro broth dilution method. The MIC and MBC values determined on days 1, 3, 7, 10, 14 and 20 for each of the fluoroquinolone drugs against the planktonic and biofilm forms of avian S. gallinarum were found to be non-significant. BEC values determined against the biofilm forms of S. gallinarum during the study period were found to be non-significant among the tested fluoroquinolones. The results of the present study demonstrated that fluoroquinolone drugs were effective in vitro against both the planktonic and biofilm forms of avian S. gallinarum.


1969 ◽  
Vol 18 (1) ◽  
pp. 21-23 ◽  
Author(s):  
John E. Martin ◽  
Arzell Lester ◽  
Douglas S. Kellogg ◽  
James D. Thayer

1969 ◽  
Vol 134 (12) ◽  
pp. 1427-1429 ◽  
Author(s):  
C. W. Halverson ◽  
T. F. Keys ◽  
E. J. Clarke

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S312-S312
Author(s):  
Yang Yang ◽  
Demei Zhu

Abstract Background Contezolid (MRX-I) is an oxazolidinone in development for the treatment of acute bacterial skin and skin structure infections (ABSSSIs). In this study, in vitro susceptibility (S) for Contezolid and comparator agents for Gram-positive (GP) and anaerobic isolates from Phase 3 ABSSSI clinical trials were determined. Methods 313 isolates were collected from 65 participated sites and sent to a central laboratory for MIC testing. Clinical isolates included 34 anaerobes (15 Finegoldia magna, 8 Actinomyces spp., 4 Prevotella spp., 3 Propionibacterium avidum, 2 Peptostreptococcus spp., 1 Veillonella spp. and 1 Bacteroides fragilis), 187 S. aureus (59.7%). 12 S. pyogenes, 5 Enterococcus, and 75 other Gram-positive organisms. Broth micro-dilution method was used to determine the MIC of contezolid, linezolid, and other comparators to facultative isolates. Agar dilution was carried out for the anaerobes. Results For both 33 MRSA and 154 MSSA MIC50/90 values of contezolid and linezolid were 2 mg/L. One E. faecalis showed decreased susceptibility to oxazolidinones (both MIC = 4). 1 mg/L contezolid and linezolid could inhibit 12 S. pyogenes. 2 mg/L contezolid and linezolid could inhibit 15 Finegoldia magna. 0.5 mg/L contezolid and linezolid could inhibit 8 Actinomyces spp. To one Bacteroides fragili, two Prevotella bivia and one Leuconostoc lactis (Intrinsic resistant to vancomycin) the MIC of contezolid were 4 or 8 mg/L. In general, Contezolid had lower or equal MIC50/90 values against both GP and ANA species compared with linezolid for all organisms. Conclusion Contezolid demonstrated potent in vitro antibacterial activity against Gram-positive and anaerobic isolates tested. These data suggest that contezolid might be a beneficial supplement to the arena against MDR Gram-positive infection. Disclosures All authors: No reported disclosures.


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