scholarly journals Antistaphylococcal Activity of Dihydrophthalazine Antifolates, a Family of Novel Antibacterial Drugs

2009 ◽  
Vol 53 (4) ◽  
pp. 1353-1361 ◽  
Author(s):  
Catherine Clark ◽  
Lois M. Ednie ◽  
Gengrong Lin ◽  
Kathy Smith ◽  
Klaudia Kosowska-Shick ◽  
...  
Keyword(s):  
Serial Passage ◽  
Single Step ◽  
Coagulase Negative Staphylococcus ◽  
Considerable Variability ◽  
Coagulase Negative Staphylococci ◽  
Resistance Development ◽  
Methicillin Resistant ◽  
Antistaphylococcal Activity ◽  
Resistant Strains ◽  
Vancomycin Resistant

ABSTRACT For a panel of 153 Staphylococcus aureus clinical isolates (including 13 vancomycin-intermediate or heterogeneous vancomycin-intermediate and 4 vancomycin-resistant strains), MIC50s and MIC90s of three novel dihydrophthalazine antifolates, BAL0030543, BAL0030544, and BAL0030545, were 0.03 and 0.25 μg/ml, respectively, for methicillin-susceptible strains and 0.03 and ≤0.25 μg/ml, respectively, for methicillin-resistant strains. For a panel of 160 coagulase-negative staphylococci (including 5 vancomycin-intermediate and heterogeneous vancomycin-intermediate strains and 7 linezolid-nonsusceptible strains), MIC50s and MIC90s were ≤0.03 and ≤0.06 μg/ml, respectively, for methicillin-susceptible strains and 0.06 and 0.5 μg/ml, respectively, for methicillin-resistant strains. Vancomycin was active against 93.0% of 313 staphylococci examined; linezolid was active against all S. aureus strains and 95.6% of coagulase-negative staphylococcus strains, whereas elevated MICs of clindamycin, minocycline, trimethoprim, and rifampin for some strains were observed. At 4× MIC, the dihydrophthalazines were bactericidal against 11 of 12 staphylococcal strains surveyed. The prolonged serial passage of some staphylococcal strains in the presence of subinhibitory concentrations of BAL0030543, BAL0030544, and BAL0030545 produced clones for which dihydrophthalazines showed high MICs (>128 μg/ml), although rates of endogenous resistance development were much lower for the dihydrophthalazines than for trimethoprim. Single-step platings of naïve staphylococci onto media containing dihydrophthalazine antifolates indicated considerable variability among strains with respect to preexistent subpopulations nonsusceptible to dihydrophthalazine antifolates.

scholarly journals Antistaphylococcal Activity of Ceftobiprole, a New Broad-Spectrum Cephalosporin

2005 ◽  
Vol 49 (10) ◽  
pp. 4210-4219 ◽  
Author(s):  
Tatiana Bogdanovich ◽  
Lois M. Ednie ◽  
Stuart Shapiro ◽  
Peter C. Appelbaum
Keyword(s):  
Active Component ◽  
Serial Passage ◽  
Coagulase Negative Staphylococci ◽  
Low Frequencies ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Antistaphylococcal Activity ◽  
Amoxicillin Clavulanate ◽  
Resistant Strains ◽  
Vancomycin Resistant

ABSTRACT Ceftobiprole (formerly BAL9141), the active component of the prodrug BAL5788 (ceftobiprole medocaril), is a novel cephalosporin with expanded activity against gram-positive bacteria. Among 152 Staphylococcus aureus isolates, including 5 vancomycin-intermediate and 2 vancomycin-resistant strains, MIC50 and MIC90 values for ceftobiprole were each 0.5 μg/ml against methicillin-susceptible strains and 2 μg/ml against methicillin-resistant strains. Against 151 coagulase-negative staphylococci (including 4 vancomycin-intermediate strains), MIC50 and MIC90 values were, respectively, 0.125 μg/ml and 1 μg/ml against methicillin-susceptible and 1 μg/ml and 2 μg/ml against methicillin-resistant strains. Teicoplanin was less active than vancomycin against coagulase-negative strains. Linezolid, quinupristin-dalfopristin, and daptomycin were active against all strains, whereas increased MICs for amoxicillin-clavulanate, cefazolin, minocycline, gentamicin, trimethoprim-sulfamethoxazole, levofloxacin, rifampin, mupirocin, fusidic acid, and fosfomycin were sometimes observed. At 2× MIC, ceftobiprole was bactericidal against 11 of 12 test strains by 24 h. Prolonged serial passage in the presence of subinhibitory concentrations of ceftobiprole failed to select for clones with MICs >4 times those of the parents; the maximum MIC achieved for ceftobiprole after 50 passages (in 1 of 10 strains) was 8 μg/ml. Single-passage selections showed very low frequencies of resistance to ceftobiprole irrespective of genotype or phenotype; the maximal ceftobiprole MIC of recovered clones was 8 μg/ml.

scholarly journals Antistaphylococcal Activity of DX-619, a New Des-F(6)-Quinolone, Compared to Those of Other Agents

2005 ◽  
Vol 49 (8) ◽  
pp. 3325-3333 ◽  
Author(s):  
Tatiana Bogdanovich ◽  
Duygu Esel ◽  
Linda M. Kelly ◽  
Bülent Bozdogan ◽  
Kim Credito ◽  
...  
Keyword(s):  
Single Step ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Coagulase Negative Staphylococci ◽  
Resistance Selection ◽  
Antistaphylococcal Activity ◽  
Resistant Strains ◽  
Vancomycin Resistant ◽  
Resistant Mutants

ABSTRACT The in vitro activity of DX-619, a new des-F(6)-quinolone, was tested against staphylococci and compared to those of other antimicrobials. DX-619 had the lowest MIC ranges/MIC50s/MIC90s (μg/ml) against 131 Staphylococcus aureus strains (≤0.002 to 2.0/0.06/0.5) and 128 coagulase-negative staphylococci (0.004 to 0.25/0.016/0.125). Among strains tested, 76 S. aureus strains and 51 coagulase-negative staphylococci were resistant to ciprofloxacin. DX-619 had the lowest MIC50/MIC90 values against 127 quinolone-resistant staphylococci (0.125/0.5), followed by sitafloxacin (0.5/4), moxifloxacin (2/8), gatifloxacin (4/16), levofloxacin (16/>32), and ciprofloxacin (>32/>32). Raised quinolone MICs were associated with mutations in GyrA (S84L) and single or double mutations in GrlA (S80F or Y; E84K, G, or V) in all S. aureus strains tested. A recent vancomycin-resistant S. aureus (VRSA) strain (Hershey) was resistant to available quinolones and was inhibited by DX-619 at 0.25 μg/ml and sitafloxacin at 1.0 μg/ml. Vancomycin (except VRSA), linezolid, ranbezolid, tigecycline, and quinupristin-dalfopristin were active against all strains, and teicoplanin was active against S. aureus but less active against coagulase-negative staphylococci. DX-619 produced resistant mutants with MICs of 1 to >32μ g/ml after <50 days of selection compared to 16 to> 32 μg/ml for ciprofloxacin, sitafloxacin, moxifloxacin, and gatifloxacin. DX-619 and sitafloxacin were also more active than other tested drugs against selected mutants and had the lowest mutation frequencies in single-step resistance selection. DX-619 and sitafloxacin were bactericidal against six quinolone-resistant (including the VRSA) and seven quinolone-susceptible strains tested, whereas gatifloxacin, moxifloxacin, levofloxacin, and ciprofloxacin were bactericidal against 11, 10, 7, and 5 strains at 4× MIC after 24 h, respectively. DX-619 was also bactericidal against one other VRSA strain, five vancomycin-intermediate S. aureus strains, and four vancomycin-intermediate coagulase-negative staphylococci. Linezolid, ranbezolid, and tigecycline were bacteriostatic and quinupristin-dalfopristin, teicoplanin, and vancomycin were bactericidal against two, eight, and nine strains, and daptomycin and oritavancin were rapidly bactericidal against all strains, including the VRSA. DX-619 has potent in vitro activity against staphylococci, including methicillin-, ciprofloxacin-, and vancomycin-resistant strains.

scholarly journals Antistaphylococcal Activity of CB-181963 (CAB-175), an Experimental Parenteral Cephalosporin

2004 ◽  
Vol 48 (10) ◽  
pp. 4037-4039 ◽  
Author(s):  
Dianne B. Hoellman ◽  
Glenn A. Pankuch ◽  
Peter C. Appelbaum
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Methicillin Resistant ◽  
Antistaphylococcal Activity ◽  
Resistant Strains ◽  
Vancomycin Resistant

ABSTRACT Among 265 methicillin-susceptible and -resistant staphylococci, CB-181963 (CAB-175) had a 50% minimum inhibitory concentration of 2 μg/ml and a 90% minimum inhibitory concentration of 4 μg/ml. All strains except two vancomycin-resistant S. aureus and 5 vancomycin-intermediate S. aureus strains were also susceptible to vancomycin and teicoplanin, and all were susceptible to linezolid, ranbezolid, tigecycline, and quinupristin-dalfopristin. Most methicillin-resistant strains were levofloxacin resistant. CB-181963 was bactericidal against all six methicillin-resistant strains at four times the MIC after 24 h.

Multidrug resistant coagulase-negative Staphylococcus spp. isolated from cases of chronic rhinosinusitis in humans. Study from Poland

2021 ◽  
Keyword(s):  
Chronic Rhinosinusitis ◽  
Pathogenic Bacteria ◽  
Medical Center ◽  
Multidrug Resistant ◽  
Coagulase Negative Staphylococcus ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Resistant Strains ◽  
Ethmoid Sinuses ◽  
Staphylococcus Spp

Abstract For many years, coagulase-negative staphylococci (CoNS) have been considered non-pathogenic bacteria. However, recently, CoNS are becoming more common bacteriological factors isolated from cases of chronic rhinosinusitis in humans. Moreover, most of them represent the multidrug-resistant or/and methicillin-resistant profile, which significantly increases the therapeutic difficulties. The aim of the study was to characterize profile of resistant coagulase-negative staphylococci isolated from cases of chronic rhinosinusitis in patients treated in a Medical Center in Warsaw in 2015–2016. The study material was derived from patients with diagnosed chronic rhinosinusitis treated at the MML Medical Center in Warsaw. The material was obtained intraoperatively from maxillary, frontal, and ethmoid sinuses. In total, 1,044 strains were isolated from the studied material. Coagulase-negative staphylococci were predominant, with the largest share of Staphylococcus epidermidis. Isolated CoNS were mainly resistant to macrolide, lincosamide, and tetracycline. Among the S. epidermidis strains, we also showed 35.6% of MDR and 34.7% of methicillin-resistant strains. The same values for other non-epidermidis species were 31.5% and 18.5%, respectively and the percentage of strains with MAR >0.2 was greater in S. epidermidis (32.6%) than S. non-epidermidis (23.9%). Although the percentage of strains resistant to tigecycline, glycopeptides, rifampicin and oxazolidinones was very small (2.3%, 1.9%, 1.4% and 0.7% respectively), single strains were reported in both groups. The study has shown a high proportion of MDR and methicillin-resistant CoNS strains, which indicates a large share of drug-resistant microorganisms in the process of persistence of chronic rhinosinusitis; therefore, isolation of this group of microorganisms from clinical cases using aseptic techniques should not be neglected.

scholarly journals Species-Specific Sensitivity of Coagulase-Negative Staphylococci to Single Antibiotics and Their Combinations

2011 ◽  
Vol 60 (2) ◽  
pp. 155-161 ◽  
Author(s):  
GRAŻYNA SZYMAŃSKA ◽  
MAGDALENA SZEMRAJ ◽  
ELIGIA M. SZEWCZYK
Keyword(s):  
University Hospital ◽  
Hospital Environment ◽  
Beta Lactam ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Beta Lactam Antibiotics ◽  
Resistant Strains ◽  
Staphylococcus Hominis ◽  
Species Specific

The activity of beta-lactam antibiotics (oxacillin, cloxacillin, cephalotin), vancomycin, gentamicin and rifampicin applied in vitro individually and in combination against 37 nosocomial methicillin-resistant strains of coagulase-negative staphylococci (CNS) was assessed to demonstrate the heterogeneity of this group of bacteria and estimate the chance of the efficacy of such therapy. The strains belonged to four species: Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus cohnii, Staphylococcus hominis. They originated from a hospital environment and from the skin of medical staff of the intensive care unit of a paediatric ward at a university hospital. All strains were methicillin-resistant, according to CLSI standards, but individual strains differed in MIC(ox) values. Susceptibility to other tested antibiotics was also characteristic for the species. The increased susceptibility to antibiotics in combinations, tested by calculating the fractional inhibitory concentration (FIC) index, concerned 26 out of 37 investigated strains and it was a feature of a particular species. Combinations of vancomycin and cephalotin against S. epidermidis and oxacillin with vancomycin were significant, as well as cephalotin and rifampicin in growth inhibition of multiresistant S. haemolyticus strains.

MICROFLORA OF SURGICAL WOUNDS AND FISTULAS IN PATIENTS WITH CHRONIC OSTEOMYELITIS OF THE TIBIA BEFORE RECONSTRUCTIVE TREATMENT, IN CASE OF RECURRENCE OF INFECTION

2019 ◽  
Vol 64 (10) ◽  
pp. 627-631
Author(s):  
S. I. Burnashov ◽  
I. V. Shipitsyna ◽  
E. V. Osipova
Keyword(s):  
Chronic Osteomyelitis ◽  
Primary Cultures ◽  
Acquired Resistance ◽  
Rational Approach ◽  
Coagulase Negative Staphylococcus ◽  
Methicillin Resistant ◽  
Microbiological Study ◽  
Microbiological Monitoring ◽  
New Associations ◽  
Resistant Strains

Relevance of microbiological monitoring in chronic osteomyelitis of the tibia developed during treatment of fractures with a plate is associated with a noticeable increase of various kinds of the microflora. A microbiological study was conducted of pathological material taken from wounds, fistulas and from the focus of inflammation in 49 patients with chronic tibial osteomyelitis, developed during treatment of fractures with a plate. The patients underwent sequestrectomy of the tibia and subsequent application of bilocal consecutive compression-distraction osteosynthesis or monolocal compression osteosynthesis. Microbiological study of smears taken before the reconstructive treatment from fistulas and wounds of patients showed that in mono-culture there were 30 strains, the remaining 30 - as a part of 14 two - and three-component associations. The frequency of S. aureus strains was 55.3%, followed by coagulase-negative staphylococcus - 13.6% and representatives of the family Enterobacteriacae - 10.2%. There were methicillin-resistant strains of S. aureus in 11.8%, strains of coagulase-negative staphylococcus (MRCoNS) - 6.8%. Recurrence of the disease was observed in 7 patients. The microflora of the discharge from the fistula was represented by monocultures of S. aureus and associations of bacteria in which one of the components was methicillin-resistant strains of S. aureus. We observed differences in the contents of the microflora before reconstructive treatment of patients and in recurrence of infection. In case of recurrence of infection, the qualitative contents of the microflora changed: in 2 patients in the association of microorganisms and in 3 - in monocultures, S. aureus strains acquired resistance to ß-lactam antibiotics, new associations appeared, which were not present in primary cultures before reconstructive treatment. The study showed that the spectrum of micro-organisms in chronic osteomyelitis of the tibia, developed after osteosynthesis with a plate, varied and is subject to change and that dictates the need for microbiological monitoring to detect the etiological structure of pathogens, monitoring of antibiotic resistance of the isolated strains and rational approach to treatment of patients.

scholarly journals In Vitro Antibacterial Activities of DQ-113, a Potent Quinolone, against Clinical Isolates

2002 ◽  
Vol 46 (3) ◽  
pp. 904-908 ◽  
Author(s):  
Mayumi Tanaka ◽  
Emi Yamazaki ◽  
Megumi Chiba ◽  
Kiyomi Yoshihara ◽  
Takaaki Akasaka ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Moraxella Catarrhalis ◽  
Antibacterial Agents ◽  
Antibacterial Activities ◽  
Clinical Isolates ◽  
Coagulase Negative Staphylococci ◽  
Vancomycin Resistant Enterococci ◽  
Resistant Strains ◽  
Vancomycin Resistant

ABSTRACT The antibacterial activity of DQ-113, formerly D61-1113, was compared with those of antibacterial agents currently available. MICs at which 90% of the isolates tested are inhibited (MIC90s) of DQ-113 against clinical isolates of methicillin-susceptible and -resistant Staphylococcus aureus and methicillin-susceptible and -resistant coagulase-negative staphylococci were 0.03, 0.008, 0.03, and 0.06 μg/ml, respectively. Moreover, DQ-113 showed the most potent activity against ofloxacin-resistant and methicillin-resistant S. aureus, with a MIC90 of 0.25μg/ml. DQ-113 inhibited the growth of all strains of Streptococcus pneumoniae, including penicillin-resistant strains, and Streptococcus pyogenes at 0.06 μg/ml, and DQ-113 was more active than the other quinolones tested against Enterococcus faecalis and Enterococcus faecium with MIC90s of 0.25 and 2 μg/ml, respectively. Against vancomycin-resistant enterococci, DQ-113 showed the highest activity among the reference compounds, with a MIC range from 0.25 to 2 μg/ml. DQ-113 also showed a potent activity against Haemophilus influenzae, including ampicillin-resistant strains (MIC90, 0.015 μg/ml), and Moraxella catarrhalis (MIC90, 0.03 μg/ml). The activity of DQ-113 was roughly comparable to that of levofloxacin against all species of Enterobacteriaceae. The MICs of DQ-113 against ofloxacin-susceptible Pseudomonas aeruginosa ranged from 0.25 to 2 μg/ml, which were four times higher than those of ciprofloxacin. From these results, DQ-113 showed the most potent activity against gram-positive pathogens among antibacterial agents tested.

Methicillin-ResistantS. aureusandS. epidermidisStrains: Modern Hospital Pathogens

1986 ◽  
Vol 7 (S2) ◽  
pp. 118-119 ◽  
Author(s):  
Richard P. Wenzel
Keyword(s):  
Staphylococcus Aureus ◽  
Infection Control ◽  
Weight Of Evidence ◽  
Effective Control ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Nosocomial Pathogens ◽  
International Recognition ◽  
Resistant Strains ◽  
Modern Hospital

The international recognition of the emergence of methicillin-resistantStaphylococcus aureusas major nosocomial pathogens dates to the late 1970s. The weight of evidence from many institutions suggests that transmission involves spread from patient to patient of the same or very similar strain and that effective control, if not elimination, involves isolation of infected and colonized patients.More recently, a number of reports have suggested the emergence of methicillin-resistantS. epidermidisand other coagulase-negative staphylococci as significant nosocomial pathogens. Although the organisms undoubtedly share many similarities with methicillin-resistant strains ofS. aureus, it is certain that biologic differences exist which are important for infection control.

scholarly journals In VitroActivity against Staphylococcus aureus of a Novel Antimicrobial Agent, PRF-119, a Recombinant Chimeric Bacteriophage Endolysin

2011 ◽  
Vol 55 (9) ◽  
pp. 4416-4419 ◽  
Author(s):  
Evgeny A. Idelevich ◽  
Christof von Eiff ◽  
Alexander W. Friedrich ◽  
Domenico Iannelli ◽  
Guoqing Xia ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agent ◽  
The Novel ◽  
Good Activity ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Content Type ◽  
Microdilution Method ◽  
Antistaphylococcal Activity ◽  
Bacteriophage Endolysin

ABSTRACTAntistaphylococcal activity of the novel chimeric endolysin PRF-119 was evaluated with the microdilution method. The MIC50and MIC90of 398 methicillin-susceptibleStaphylococcus aureusisolates were 0.098 μg/ml and 0.391 μg/ml, respectively (range, 0.024 to 0.780 μg/ml). Both the MIC50and MIC90values of 776 methicillin-resistantS. aureusisolates were 0.391 μg/ml (range, 0.024 to 1.563 μg/ml). All 192 clinical isolates of coagulase-negative staphylococci exhibited MIC values of >50 μg/ml. In conclusion, PRF-119 exhibited very good activity specifically againstS. aureus.

scholarly journals Aktivitas Antimikroba Fraksi Etil Asetat Daun Ceremai [Phyllanthus acidus (L.) Skeels] terhadap Bakteri Resisten Antimikroba dan Jamur dengan Metode KLT Bioautografi

2020 ◽  
Vol 4 ◽  
Author(s):  
Lanny Mulqie ◽  
Kusnandar Anggadireja
Keyword(s):  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Aspergillus Niger ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Coagulase Negative Staphylococcus ◽  
Microsporum Gypseum ◽  
Vancomycin Resistant Enterococcus ◽  
Methicillin Resistant ◽  
Phyllanthus Acidus ◽  
Vancomycin Resistant

Resistensi dan toksisitas antimikroba menyebabkan penggunaan obat herbal sebagai alternatif  pengobatan berbagai penyakit yang disebabkan oleh mikroba. Ekstrak etanol daun ceremai memiliki aktivitas terhadap VRE, MRCNS, dan Candida albicans. Penelitian ini bertujuan untuk mengetahui aktivitas antimikroba fraksi etil asetat daun ceremai terhadap bakteri resisten antimikroba [Methicillin-Resistant Staphylococcus aureus (MRSA), Methicillin-Resistant Coagulase Negative Staphylococcus (MRCNS), Vancomycin Resistant Enterococcus (VRE)] dan jamur uji (Candida albicans, Microsporum gypseum, dan Aspergillus niger) dengan metode KLT bioautografi. Fraksinasi dilakukan dengan cara ekstraksi cair-cair menggunakan pelarut dengan tingkat kepolaran yang berbeda, yaitu n-heksan, etil asetat, dan air. KLT bioautografi pada fraksi etil asetat daun ceremai dilakukan menggunakan fase diam silika gel GF254 dan pengembang etil asetat-asam format-asam asetat-air (100:10:10:22), menggunakan sitroborat sebagai penampak bercak. Pada hasil kromatogram terdapat 5 noda yang berfluoresensi hijau kekuningan dengan nilai rf noda 1 sebesar 0,35; noda 2 sebesar 0,43, noda 3 sebesar 0,62, noda 4 sebesar 0,75 dan noda 5 sebesar 0,90 setelah plat disemprot oleh sitroborat dan dilihat di bawah sinar UV. Hasil pengujian aktivitas antimikroba dengan metode KLT bioautografi menunjukkan terbentuknya zona bening yang dihasilkan noda pada plat yang ditempelkan pada media. Fraksi etil asetat daun ceremai memiliki aktivitas antimikroba terhadap bakteri resisten antimikroba (MRSA, MRCNS, dan VRE) dan jamur  uji (Candida albicans, Microsporum gypseum, dan Aspergillus niger) yang dihasilkan oleh noda 1 (rf 0,35), noda 2 (rf 0,43), noda 3 (rf 0,62), noda 4 (rf 0,75), dan noda 5 (rf 0,90). Golongan senyawa yang diduga memiliki aktivitas antimikroba adalah flavonoid.

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