COMPARISON BETWEEN SOME PENICILLIN-G RESISTANT STRAINS OF STAPHYLOCOCCUS AUREUS PREPARED IN VITRO AND THEIR PARENT STRAINS

1964 ◽  
Vol 60 (3) ◽  
pp. 420-430 ◽  
Author(s):  
LENNART WAHLSTRÖM ◽  
BIRGITTA NORKRANS
Keyword(s):  
Staphylococcus Aureus ◽  
Penicillin G ◽  
Resistant Strains

scholarly journals Changes in Antibiotic Susceptibility Pattern of Atypical Staphylococcus Aureus Strains Isolated from Cows of the same Herd in 2008-2010

2012 ◽  
Vol 56 (2) ◽  
pp. 139-143
Author(s):  
Magdalena Małkińska-Horodyska ◽  
Joanna Kubiak ◽  
Henryka Lassa ◽  
Edward Malinowski
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Penicillin G ◽  
Diffusion Method ◽  
Conventional Pcr ◽  
Antibiotic Susceptibility Pattern ◽  
Microdilution Method ◽  
Resistant Strains ◽  
One Year

Abstract The isolates of Staphylococcus aureus strains were examined phenotypically by cultural features, tube coagulase test and clumping factor (CF), and genotypically by conventional PCR. The strains had positive reaction in CF test, but were negative in tube coagulase test. The analysed strains from the same cows in each year expressed also nuc and coa genes. About 25% of the strains were examined by the disc diffusion method for their sensitivity to antibiotics. During three years, the strains were highly susceptible in vitro to amoxicillin with clavulanic acid, oxacillin, bacitracin, and cefoperazone (more than 90%), and highly resistant to tetracycline, neomycin, and streptomycin. Forty randomly chosen strains, and eight strains from the same cows in each year were analysed for minimal inhibitory concentration of penicillin G using microdilution method. An increasing resistance to the penicillin was noted. Moreover, eight strains, the same in each year, were also examined for β-lactamase production and methicillin resistance. No β-lactamase producers and no methicillin resistant strains were found using phenotypic and genotypic methods. In conclusion, it can be stated that antimicrobial susceptibility can change from one year to another.

THE IN VITRO EFFECT OF LYSOSTAPHIN ON CLINICAL ISOLATES OF STAPHYLOCOCCUS AUREUS

1964 ◽  
Vol 10 (6) ◽  
pp. 823-828 ◽  
Author(s):  
C. Bruce Cropp ◽  
Edward F. Harrison
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Isolate ◽  
Clinical Isolates ◽  
Penicillin G ◽  
Aureus Strain ◽  
In Vitro Susceptibility ◽  
Clinical Strains ◽  
Resistant Strains ◽  
Vitro Effect

Lysostaphin, an antibiotic that is unique inasmuch as it lyses all strains of Staphylococcus aureus, has been tested against 252 strains obtained from clinical sources. The clinical isolates were phage typed and tested for in vitro susceptibility to lysostaphin and seven other antistaphylococcal antibiotics.The resistant strains, found generally in phage groups I, III, and Insensitive, were most susceptible to vancomycin, lysostaphin, ristocetin, and kanamycin. The antibiotics least effective were penicillin G, tetracycline, phenethicillin, and erythromycin. As an attempt to quantitate the susceptibility of various clinical strains of 5.S. aureus to lysostaphin, a "lysostaphin index" was devised in which, by an arbitrary criterion, the susceptibility of a clinical isolate was related to the sensitivity of S. aureus, strain FDA 209P. It was found that all isolates were lysed by lysostaphin.

Enterotoxigenic and Antibiotic Resistance Determination of Staphylococcus aureus Strains Isolated from Food Handlers in Gaborone, Botswana

2007 ◽  
Vol 70 (12) ◽  
pp. 2764-2768 ◽  
Author(s):  
DANIEL LOETO ◽  
M. I. MATSHEKA ◽  
B. A. GASHE
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Nasal Cavity ◽  
Penicillin G ◽  
Food Handlers ◽  
Carriage Rate ◽  
Methicillin Resistant ◽  
Resistant Strains ◽  
High Standards

The prevalence, antibiotic resistance, and enterotoxigenic potential of Staphylococcus aureus strains from different anatomical sites on food handlers in Gaborone, Botswana, were determined. Of a total of 200 food handlers tested, 115 (57.5%) were positive for S. aureus. Of the 204 S. aureus isolates, 63 (30.9%), 91 (44.6%), and 50 (24.5%) were isolated from the hand, nasal cavity, and face, respectively, and 43 (21%) of the isolates were enterotoxigenic. The most prevalent enterotoxin was type A, which accounted for 34.9% of all the enterotoxigenic strains, and enterotoxin D was produced by the fewest number of strains (9.3%). Resistance to methicillin was encountered in 33 (22.4%) of the penicillin G–resistant isolates, and 9 (27.3%) of these methicillin-resistant isolates also were resistant to vancomycin. Nineteen antibiotic resistance profiles were determined, and the nasal cavity had the highest diversity of resistance profiles. The nasal cavity also had the highest number of resistant strains, 77 (53%), whereas the hand and face had 49 (32%) and 24 (16.0%) resistant strains, respectively. To reduce the Staphylococcus carriage rate among food handlers, training coupled with a commitment to high standards of personal and environmental hygiene is recommended.

scholarly journals Mercury resistance of Staphylococcus aureus

1970 ◽  
Vol 68 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Barbara M. Hall
Keyword(s):  
Staphylococcus Aureus ◽  
Nasal Carriage ◽  
Mercury Resistance ◽  
Development Of Resistance ◽  
Mercury Salts ◽  
Local Endemic ◽  
Resistant Strains ◽  
Endemic Strain ◽  
Made In

SummaryReasons for the accumulation of mercury-resistant strains of Staphylococcus aureus in hospital have been studied. A collection of paired strains, that is staphylococci similar in every respect except sensitivity to mercury salts, was made. Tests were made in an attempt to demonstrate a link between mercury resistance and some other factor which might aid survival, viz. resistance to drying and heat, production of bound coagulase, growth in the presence of sublethal amounts of tetracycline, survival in human blood at 37°C. and uptake by polymorphs at 30°0. and 37°C., development of resistance to antibiotics and competition in mixed cultures. It was not possible to demonstrate any consistent link between mercury resistance and any of these properties. Paper strips impregnated with the mercurial diuretic, Mersalyl, were shown to differentiate between mercury-resistant and -sensitive strains in vitro. Furthermore, development of resistance to mercury by passage in mercuric chloride-broth was demonstrated.It is proposed that mercury resistance has developed as a result of exposure to the mercury ion. Mercurial diuretics have been frequently used in medical and geriatric patients and it is among these that the higher carrier rates of mercury-resistant strains are found even when the local endemic strain is disregarded. In obstetric patients, where mercurials are seldom used, mercury-resistant strains are rare.Nasal carriage of factory workers exposed to mercury products showed that this group is likely to carry resistant or partially resistant strains.

scholarly journals Amoxicillin-Clavulanate Therapy Increases Childhood Nasal Colonization by Methicillin-Susceptible Staphylococcus aureus Strains Producing High Levels of Penicillinase

2004 ◽  
Vol 48 (12) ◽  
pp. 4618-4623 ◽  
Author(s):  
Didier Guillemot ◽  
Stephane Bonacorsi ◽  
John S. Blanchard ◽  
Philippe Weber ◽  
Sylvie Simon ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Drug Use ◽  
Odds Ratio ◽  
Selection Process ◽  
Nasal Carriage ◽  
Penicillin G ◽  
Nasal Colonization ◽  
Factors Associated ◽  
Amoxicillin Clavulanate ◽  
Resistant Strains

ABSTRACT We examined factors associated with penicillinase production by nasal carriage Staphylococcus aureus strains in 648 children aged 3 to 6 years attending 20 randomly sampled playschools. The children were prospectively monitored for drug use and medical events for 6 months and were then screened for S. aureus carriage. Isolates were tested for their susceptibility to penicillin G and methicillin, and penicillinase production by methicillin-susceptible, penicillin-resistant strains was quantified. S. aureus was isolated from 166 children (25.6%). Exposure to amoxicillin-clavulanate during the previous 3 months was associated with higher penicillinase production by penicillin-resistant, methicillin-susceptible strains (odds ratio, 3.6; P = 0.03). These results suggest that use of the amoxicillin-clavulanate combination could induce a herd selection process of S. aureus strains producing higher levels of penicillinase.

scholarly journals Introduction of the mec Element (Methicillin Resistance) into Staphylococcus aureus Alters In Vitro Functional Activities of Fibrinogen and Fibronectin Adhesins

1998 ◽  
Vol 42 (3) ◽  
pp. 564-570 ◽  
Author(s):  
Pierre E. Vaudaux ◽  
Vincenza Monzillo ◽  
Patrice Francois ◽  
Daniel P. Lew ◽  
Tim J. Foster ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Bacterial Colonization ◽  
Protein A ◽  
Methicillin Resistant ◽  
Functional Activities ◽  
Extracellular Matrix Components ◽  
Resistant Strains ◽  
The Impact

ABSTRACT Some methicillin-resistant strains of Staphylococcus aureus are defective in the production of major surface components such as protein A, clumping factor, or other important adhesins to extracellular matrix components which may play a role in bacterial colonization and infection. To evaluate the impact of methicillin resistance (mec) determinants on bacterial adhesion mediated by fibrinogen or fibronectin adhesins, we compared the in vitro attachment of two genetically distinct susceptible strains (NCTC8325 and Newman) to protein-coated surfaces with that of isogenic methicillin-resistant derivatives. All strains containing an intactmec element in their chromosomes were found to be defective in adhesion to fibrinogen and fibronectin immobilized on polymethylmethacrylate coverslips, regardless of the presence or absence of additional mutations in the femA,femB, or femC gene, known to decrease expression of methicillin resistance in S. aureus. Western ligand affinity blotting or immunoblotting of cell wall-associated adhesins revealed similar contents of fibrinogen- or fibronectin-binding proteins in methicillin-resistant strains compared to those of their methicillin-susceptible counterparts. In contrast to methicillin-resistant strains carrying a mec element in their genomes, methicillin-resistant strains constructed in vitro, by introducing the mecA gene on a plasmid, retained their adhesion phenotypes. In conclusion, the chromosomal insertion of themec element into genetically defined strains of S. aureus impairs the in vitro functional activities of fibrinogen or fibronectin adhesins without altering their production. This effect is unrelated to the activity of the mecA gene.

scholarly journals A bacteriocin-based antimicrobial formulation to effectively disrupt the cell viability of methicillin-resistant Staphylococcus aureus (MRSA) biofilms

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Christian Kranjec ◽  
Kirill V. Ovchinnikov ◽  
Torstein Grønseth ◽  
Kumar Ebineshan ◽  
Aparna Srikantam ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Viability ◽  
Cell Damage ◽  
Penicillin G ◽  
Antibiotic Resistant ◽  
Methicillin Resistant ◽  
Lactam Antibiotic ◽  
Mrsa Strains ◽  
Therapeutic Tools

AbstractAntibiotic-resistant and biofilm-associated infections brought about by methicillin-resistant Staphylococcus aureus (MRSA) strains is a pressing issue both inside as well as outside nosocomial environments worldwide. Here, we show that a combination of two bacteriocins with distinct structural and functional characteristics, garvicin KS, and micrococcin P1, showed a synergetic antibacterial activity against biofilms produced in vitro by S. aureus, including several MRSA strains. In addition, this bacteriocin-based antimicrobial combination showed the ability to restore the sensitivity of the highly resilient MRSA strain ATCC 33591 to the β-lactam antibiotic penicillin G. By using a combination of bacterial cell metabolic assays, confocal and scanning electron microscopy, we show that the combination between garvicin KS, micrococcin P1, and penicillin G potently inhibit cell viability within S. aureus biofilms by causing severe cell damage. Together these data indicate that bacteriocins can be valuable therapeutic tools in the fight against biofilm-associated MRSA infections.

scholarly journals In Vitro Activities of RWJ-54428 (MC-02,479) against Multiresistant Gram-Positive Bacteria

2001 ◽  
Vol 45 (5) ◽  
pp. 1422-1430 ◽  
Author(s):  
Suzanne Chamberland ◽  
Johanne Blais ◽  
Monica Hoang ◽  
Cynthia Dinh ◽  
Dylan Cotter ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Penicillin G ◽  
Significant Activity ◽  
Coagulase Negative Staphylococci ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Level Of Activity ◽  
Resistant Strains ◽  
High Level

ABSTRACT RWJ-54428 (MC-02,479) is a new cephalosporin with a high level of activity against gram-positive bacteria. In a broth microdilution susceptibility test against methicillin-resistant Staphylococcus aureus (MRSA), RWJ-54428 was as active as vancomycin, with an MIC at which 90% of isolates are inhibited (MIC90) of 2 μg/ml. For coagulase-negative staphylococci, RWJ-54428 was 32 times more active than imipenem, with an MIC90 of 2 μg/ml. RWJ-54428 was active against S. aureus, Staphylococcus epidermidis, and Staphylococcus haemolyticus isolates with reduced susceptibility to glycopeptides (RWJ-54428 MIC range, ≤0.0625 to 1 μg/ml). RWJ-54428 was eight times more potent than methicillin and cefotaxime against methicillin-susceptible S. aureus (MIC90, 0.5 μg/ml). For ampicillin-susceptible Enterococcus faecalis (including vancomycin-resistant and high-level aminoglycoside-resistant strains), RWJ-54428 had an MIC90 of 0.125 μg/ml. RWJ-54428 was also active against Enterococcus faecium, including vancomycin-, gentamicin-, and ciprofloxacin-resistant strains. The potency against enterococci correlated with ampicillin susceptibility; RWJ-54428 MICs ranged between ≤0.0625 and 1 μg/ml for ampicillin-susceptible strains and 0.125 and 8 μg/ml for ampicillin-resistant strains. RWJ-54428 was more active than penicillin G and cefotaxime against penicillin-resistant, -intermediate, and -susceptible strains ofStreptococcus pneumoniae (MIC90s, 0.25, 0.125, and ≤0.0625 μg/ml, respectively). RWJ-54428 was only marginally active against most gram-negative bacteria; however, significant activity was observed against Haemophilus influenzae andMoraxella catarrhalis (MIC90s, 0.25 and 0.5 μg/ml, respectively). This survey of the susceptibilities of more than 1,000 multidrug-resistant gram-positive isolates to RWJ-54428 indicates that this new cephalosporin has the potential to be useful in the treatment of infections due to gram-positive bacteria, including strains resistant to currently available antimicrobials.

scholarly journals In Vitro Activity of the Quinolone WCK 771 against Recent U.S. Hospital and Community-Acquired Staphylococcus aureus Pathogens with Various Resistance Types

2008 ◽  
Vol 53 (2) ◽  
pp. 811-813 ◽  
Author(s):  
Sachin S. Bhagwat ◽  
Pamela McGhee ◽  
Klaudia Kosowska-Shick ◽  
Mahesh V. Patel ◽  
Peter C. Appelbaum
Keyword(s):  
Staphylococcus Aureus ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Glycopeptide Resistance ◽  
Resistant Strains

ABSTRACT WCK 771 demonstrated MIC50 and MIC90s of 0.03 and 1 μg/ml, respectively, against 297 recent U.S. community-acquired and hospital strains of Staphylococcus aureus, irrespective of quinolone or glycopeptide resistance. Against quinolone-resistant strains, MIC90s of WCK 771 and moxifloxacin were 1 and 16 μg/ml, respectively.

scholarly journals Antipneumococcal Activity of ABT-773 Compared to Those of 10 Other Agents

2000 ◽  
Vol 44 (7) ◽  
pp. 1894-1899 ◽  
Author(s):  
Todd A. Davies ◽  
Lois M. Ednie ◽  
Dianne M. Hoellman ◽  
Glenn A. Pankuch ◽  
Michael R. Jacobs ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Vitro Activity ◽  
Penicillin Resistance ◽  
Penicillin G ◽  
23S Rrna ◽  
In Vitro Activity ◽  
Resistant Strains ◽  
Domain V ◽  
Kinetics Of

ABSTRACT MICs, time-kills, and postantibiotic effects (PAEs) of ABT-773 (a new ketolide) and 10 other agents were determined against 226 pneumococci. Against 78 ermB- and 44mefE-containing strains, ABT-773 MICs at which 50% of the isolates tested were inhibited (MIC50s) and MIC90s were 0.016 to 0.03 and 0.125 μg/ml, respectively. Clindamycin was active only against macrolide-resistant strains containing mefE (MIC50, 0.06 μg/ml; MIC90, 0.125 μg/ml). Activities of pristinamycin (MIC90, 0.5 μg/ml) and vancomycin (MIC90, 0.25 μg/ml) were unaffected by macrolide or penicillin resistance, while β-lactam MICs rose with those of penicillin G. Against 19 strains with L4 ribosomal protein mutations and two strains with mutations in domain V of 23S rRNA, ABT-773 MICs were 0.03 to 0.25 μg/ml, while macrolide and azalide MICs were all ≥16.0 μg/ml. ABT-773 was bactericidal at twice the MIC after 24 h for 8 of 12 strains (including three strains with erythromycin MICs greater than or equal to 64.0 μg/ml). Kill kinetics of erythromycin, azithromycin, clarithromycin, and roxithromycin against macrolide-susceptible strains were slower than those of ABT-773. ABT-773 had longer PAEs than macrolides, azithromycin, clindamycin, or β-lactams, including against ermB-containing strains. ABT-773, therefore, shows promising in vitro activity against macrolide-susceptible as well as -resistant pneumococci.

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