scholarly journals In Vitro Activities of Three Nonfluorinated Quinolones against Representative Bacterial Isolates

2001 ◽  
Vol 45 (6) ◽  
pp. 1923-1927 ◽  
Author(s):  
Arthur L. Barry ◽  
Peter C. Fuchs ◽  
Steven D. Brown
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Isolates ◽  
Gram Positive ◽  
In Vitro Susceptibility ◽  
Gram Negative ◽  
Methicillin Resistant ◽  
Inhibitory Activities ◽  
Susceptibility Tests

ABSTRACT In vitro susceptibility tests were performed to document the inhibitory activities of three nonfluorinated quinolone (NFQ) compounds (PGE 9262932, PGE 9509924, and PGE 4175997) compared to those of ciprofloxacin, levofloxacin, and trovafloxacin against 3,030 bacterial isolates. The spectra of the NFQ agents included most gram-positive species as well as quinolone-susceptibleEnterobacteriaceae. Ciprofloxacin-resistant, methicillin-resistant Staphylococcus aureus strains were inhibited by the NFQ series at ≤1.0 μg/ml. The NFQ compounds were not very active against Pseudomonas aeruginosa and most other nonfermentative gram-negative bacilli. Against other species, the potency of the NFQ agents was similar to that of trovafloxacin. Continued investigation of the NFQ compounds seems to be warranted.

scholarly journals In Vitro Pharmacodynamic Studies of L-749,345 in Comparison with Imipenem and Ceftriaxone against Gram-Positive and Gram-Negative Bacteria

1998 ◽  
Vol 42 (9) ◽  
pp. 2365-2370 ◽  
Author(s):  
Inga Odenholt ◽  
Elisabeth Löwdin ◽  
Otto Cars
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Comparative Studies ◽  
Gram Negative Bacteria ◽  
Postantibiotic Effect ◽  
Gram Positive ◽  
Gram Negative ◽  
Methicillin Resistant ◽  
Gram Negative Organisms

ABSTRACT L-749,345 is a new parenteral carbapenem with a very long half-life similar to that of ceftriaxone. The aim of the present study was to investigate different pharmacodynamic parameters of L-749,345 in comparison with those of ceftriaxone and imipenem. The following studies were performed: (i) comparative studies of the MICs of L-749,345, imipenem, and ceftriaxone for 70 strains of gram-positive and gram-negative bacteria; (ii) comparative studies of the rate of killing of gram-positive and gram-negative bacteria by L-749,345, imipenem, and ceftriaxone; (iii) studies of the postantibiotic effects of L-749,345, imipenem, and ceftriaxone; and (iv) studies of the postantibiotic sub-MIC effects of L-749,345, imipenem, and ceftriaxone. Significantly lower MICs of L-749,345 compared with those of ceftriaxone were found for all gram-negative organisms except Haemophilus influenzae. The MICs of L-749,345 were similar to those of imipenem for all organisms except Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus, for which the MICs of L-749,345 were higher. A concentration-dependent killing of methicillin-resistant S. aureus but not methicillin-susceptible strains was noted for both L-749,345 and imipenem. All three of the investigated drugs exhibited a postantibiotic effect against the gram-positive strains but exhibited no postantibiotic effect against the gram-negative strains.

scholarly journals Levofloxacin and Ciprofloxacin In Vitro Activities against 4,003 Clinical Bacterial Isolates Collected in 24 Italian Laboratories

2003 ◽  
Vol 47 (2) ◽  
pp. 816-819 ◽  
Author(s):  
Giovanni Pietro Gesu ◽  
Federico Marchetti ◽  
Laura Piccoli ◽  
Annalisa Cavallero
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Streptococcus Pneumoniae ◽  
Staphylococcus Epidermidis ◽  
Stenotrophomonas Maltophilia ◽  
Bacterial Isolates ◽  
In Vitro Susceptibility

ABSTRACT Levofloxacin showed comparable in vitro susceptibility to ciprofloxacin among Enterobacteriaceae, Pseudomonas aeruginosa, enterococci, and Staphylococcus aureus, while greater susceptibility was observed in Stenotrophomonas maltophilia and Staphylococcus epidermidis, mainly when oxacillin resistant. The susceptibility of Streptococcus pneumoniae to levofloxacin reached 99%.

scholarly journals A Novel Bioengineered Wound Product with In Vitro Capabilities to Reduce Bacteria

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Matthew Williams ◽  
◽  
Isaac Rodriguez ◽  
Axel Strombergsson, ◽  
Stefania Fabbri ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Direct Contact ◽  
Bacterial Load ◽  
Negative Control ◽  
Contact Method ◽  
Manuka Honey ◽  
Gram Positive ◽  
Gram Negative

Introduction: When microorganisms colonize a wound, there is a continuum which extends from contamination, to colonization and infection preventing a wound from healing. Biomaterials that reduce bacteria within the wound microenvironment can help progress it towards healing. Objective: This study aims to determine the in vitro bacteria reduction capabilities of a novel, commercially available bioengineered wound product (BWP) – a synthesis of gelatin (a highly purified collagen derivative), Manuka honey, and hydroxyapatite. Materials and methods: Using a direct contact method, the BWP and negative control were inoculated with suspensions of gram-positive (Staphylococcus aureus) and gram-negative (Pseudomonas aeruginosa) bacteria. After incubation for 30 minutes and 24 hours, recovery of viable organisms was performed. Results: There was a significant reduction (99.99%) in bacterial load recovered from the BWP at 24 hours compared to the negative control. Additionally, the BWP caused a significant reduction in bacterial load at 24 hours compared to 30 minutes (97% and 64% reduction for Staphylococcus aureus and Pseudomonas aeruginosa, respectively). Conclusions: The significant reduction in bacterial load in vitro suggests that the product has the potential to help manage the pathogenic bioburden of a wound..

scholarly journals The antimicrobial activity of leaves and callus extracts of Thevetia peruviana In vitro

2013 ◽  
Vol 7 (3) ◽  
pp. 74-80
Author(s):  
Salah K. M. Alhashimi ◽  
Khaleel I. Rashid ◽  
Ghoson S. Saleh ◽  
Alea M. Abdulhadi ◽  
Tara A. Taher
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Leaf Extract ◽  
Bacterial Species ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Thevetia Peruviana

The antimicrobial activity for Thevietia peruviana was evaluated by measuring inhibition zone diameter in agar using well diffusion assay. The aim of the present study was to evaluate the antimicrobial potential of Thevietia peruviana leaf extract as compared with callus extract against some bacterial strains and fungi. The results showed that the addition of 2,4-D at the concentration of 9 mg/l, and 0.1 mg/l of kinetin led to obtain callus weight reached 800 mg. It was noticed that the reduction of 2,4-D concentration up to 6 mg/l resulted in compact and green pieces of callus. The optimal weight and friable callus was obtained at 9 mg/l. Among the susceptible bacteria are the gram negative pseudomonas aeruginosa seemed to be sensitive against all concentration of Thevietia peruviana leaf and callus extracts, While Escherichia coli showed resistance with all concentrations of extracts. It was noted that the extracts were more active against gram positive staphylococcus aureus, as compared with other bacterial species. Results of this study revealed that callus extract of Thevetia peruviana possess higher activity in comparison with leaf extract against gram positive bacteria (Staphylococcus aureus, Bacillus cereus) and gram negative (Pseudomonas aeruginosa). Finally all the bioextracts were well stable at room temperature during the period of the study and did not show any reduction of activity against the bacterial strains used in this study experiments.

scholarly journals In Vitro activity of a Novel Benzoquinolizine Antibiotic, Levonadifloxacin (WCK 771) against Blood Stream Gram-Positive Isolates from a Tertiary Care Hospital

2020 ◽  
Vol 12 (03) ◽  
pp. 230-232
Author(s):  
Dhruv Mamtora ◽  
Sanjith Saseedharan ◽  
Ritika Rampal ◽  
Prashant Joshi ◽  
Pallavi Bhalekar ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Blood Stream ◽  
Tolerability Profile ◽  
Care Hospital ◽  
Coagulase Negative Staphylococci ◽  
Gram Positive ◽  
Methicillin Resistant

Abstract Background Blood stream infections (BSIs) due to Gram-positive pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) are associated with high mortality ranging from 10 to 60%. The current anti-MRSA agents have limitations with regards to safety and tolerability profile which limits their prolonged usage. Levonadifloxacin and its oral prodrug alalevonadifloxacin, a novel benzoquinolizine antibiotic, have recently been approved for acute bacterial skin and skin structure infections including diabetic foot infections and concurrent bacteremia in India. Methods The present study assessed the potency of levonadifloxacin, a novel benzoquinolizine antibiotic, against Gram-positive blood stream clinical isolates (n = 31) collected from January to June 2019 at a tertiary care hospital in Mumbai, India. The susceptibility of isolates to antibacterial agents was defined following the Clinical and Laboratory Standard Institute interpretive criteria (M100 E29). Results High prevalence of MRSA (62.5%), quinolone-resistant Staphylococcus aureus (QRSA) (87.5%), and methicillin-resistant coagulase-negative staphylococci (MR-CoNS) (82.35%) were observed among bacteremic isolates. Levonadifloxacin demonstrated potent activity against MRSA, QRSA, and MR-CoNS strains with significantly lower minimum inhibitory concentration MIC50/90 values of 0.5/1 mg/L as compared with levofloxacin (8/32 mg/L) and moxifloxacin (2/8 mg/L). Conclusion Potent bactericidal activity coupled with low MICs support usage of levonadifloxacin for the management of BSIs caused by multidrug resistant Gram-positive bacteria.

scholarly journals In Vitro and In Vivo Activities of DA-7867, a New Oxazolidinone, against Aerobic Gram-Positive Bacteria

2005 ◽  
Vol 49 (6) ◽  
pp. 2498-2500 ◽  
Author(s):  
Eun Jeong Yoon ◽  
Yeong Woo Jo ◽  
Sung Hak Choi ◽  
Tae Ho Lee ◽  
Jae Keol Rhee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Vancomycin Resistant Enterococci ◽  
Infection Models ◽  
Vancomycin Resistant

ABSTRACT In vitro and in vivo activities of DA-7867 were assessed against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae. All isolates were inhibited by DA-7867 at ≤0.78 μg/ml, a four-times-lower concentration than that of inhibition by linezolid. For murine infection models, DA-7867 also exhibited greater efficacy than linezolid against all isolates tested.

scholarly journals Nitroxide Functionalized Antibiotics Are Promising Eradication Agents against Staphylococcus aureus Biofilms

2019 ◽  
Vol 64 (1) ◽  
Author(s):  
Anthony D. Verderosa ◽  
Rabeb Dhouib ◽  
Kathryn E. Fairfull-Smith ◽  
Makrina Totsika
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Biofilms ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Microscopy Analysis ◽  
Biofilm Dispersal ◽  
Biofilm Structure ◽  
Dispersal Activity

ABSTRACT Treatment of biofilm-related Staphylococcus aureus infections represents an important medical challenge worldwide, as biofilms, even those involving drug-susceptible S. aureus strains, are highly refractory to conventional antibiotic therapy. Nitroxides were recently shown to induce the dispersal of Gram-negative biofilms in vitro, but their action against Gram-positive bacterial biofilms remains unknown. Here, we demonstrate that the biofilm dispersal activity of nitroxides extends to S. aureus, a clinically important Gram-positive pathogen. Coadministration of the nitroxide CTEMPO (4-carboxy-2,2,6,6-tetramethylpiperidin-1-yloxyl) with ciprofloxacin significantly improved the biofilm eradication activity of the antibiotic against S. aureus. Moreover, covalently linking the nitroxide to the antibiotic moiety further reduced the ciprofloxacin minimal biofilm eradication concentration. Microscopy analysis revealed that fluorescent nitroxide-antibiotic hybrids could penetrate S. aureus biofilms and enter cells localized at the surface and base of the biofilm structure. No toxicity to human cells was observed for the nitroxide CTEMPO or the nitroxide-antibiotic hybrids. Taken together, our results show that nitroxides can mediate the dispersal of Gram-positive biofilms and that dual-acting biofilm eradication antibiotics may provide broad-spectrum therapies for the treatment of biofilm-related infections.

scholarly journals In Vitro Bactericidal Activity of Human β-Defensin 3 against Multidrug-Resistant Nosocomial Strains

2006 ◽  
Vol 50 (2) ◽  
pp. 806-809 ◽  
Author(s):  
Giuseppantonio Maisetta ◽  
Giovanna Batoni ◽  
Semih Esin ◽  
Walter Florio ◽  
Daria Bottai ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bactericidal Activity ◽  
Stenotrophomonas Maltophilia ◽  
Bactericidal Effect ◽  
Multidrug Resistant ◽  
Bacterial Strains ◽  
Gram Negative

ABSTRACT The antimicrobial activity of human β-defensin 3 (hBD-3) against multidrug-resistant clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii was evaluated. A fast bactericidal effect (within 20 min) against all bacterial strains tested was observed. The presence of 20% human serum abolished the bactericidal activity of hBD-3 against gram-negative strains and reduced the activity of the peptide against gram-positive strains.

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