Showing papers on "Penicillin published in 1972"
TL;DR: The mechanism for this marked activity of rifampin in the treatment of experimental staphylococcal infections may be the unique ability of this antibiotic to kill intracellular staphyllococci.
Abstract: Many virulent Staphylococcus aureus phagocytized by polymorphonuclear neutrophils (PMN) remain viable. Human PMN were mixed with S. aureus aerobically and anaerobically, and it was observed that many intracellular bacteria survived incubation with high concentrations of nine commonly used antistaphylococcal agents. In marked contrast to this, low concentrations of rifampin completely killed intraleukocytic bacteria. Experiments were then performed to evaluate the efficacy of rifampin in staphylococcal infections in mice. Treatment with penicillin or methicillin of mice that had been given intraperitoneal injections of S. aureus was only minimally effective in reducing mortality (93.1% in untreated mice, 83% in penicillin-treated mice, and 70% in methicillin-treated mice). In contrast to this, treatment with rifampin reduced mortality to 27.1% (P < .0005). In other experiments, rifampin alone prevented the formation of abscesses resulting from subcutaneous inoculation of staphylococci. The mechanism for this marked activity of rifampin in the treatment of experimental staphylococcal infections may be the unique ability of this antibiotic to kill intracellular staphylococci.
209 citations
TL;DR: Evidence is presented that the physiological effects of penicillin on E. coli may be due to interaction with at least two specific targets, both of which are enzymes.
Abstract: Evidence is presented that the physiological effects of penicillin on E. coli may be due to interaction with at least two specific targets, both of which are enzymes.
171 citations
170 citations
TL;DR: The new penicillin was bactericidal in activity, as with other penicillins, and its antibacterial activity was not reduced in the presence of serum.
Abstract: Amoxycillin (alpha-amino-p-hydroxybenzylpenicillin) is a new semi-synthetic penicillin with a broad spectrum of antibacterial activity similar to that of ampicillin. Penicillin-sensitive strains of staphylococci, streptococci, and pneumococci were sensitive to concentrations of 0.1 mug or less of amoxycillin/ml. Strains of Haemophilus influenzae were inhibited by a level of 0.5 mug/ml, and most strains of Escherichia coli, Proteus mirabilis, Shigella sonnei, Salmonella species, and Streptococcus faecalis were sensitive to a concentration of 5 mug or less of amoxycillin/ml. Penicillinase-producing strains of Staphylococcus aureus and strains of Pseudomonas aeruginosa, indole-positive Proteus, Klebsiella, and Enterobacter were insensitive to amoxycillin. The new penicillin was bactericidal in activity, as with other penicillins, and its antibacterial activity was not reduced in the presence of serum. After oral administration to volunteer subjects amoxycillin produced serum concentrations twice as high as those obtained with similar doses of ampicillin, and the penicillin was recovered unchanged in high concentrations in the urine. The absorption of amoxycillin was not greatly influenced by food, and administration of probenecid resulted in increased and more prolonged concentrations of amoxycillin in serum.
159 citations
TL;DR: The effectiveness of ampicillin, penicillin, streptomycin, and gentamicin against 20 strains of Listeria monocytogenes was studied in vitro and combinations of these antibiotics produced enhanced killing against all strains tested.
Abstract: The effectiveness of ampicillin, penicillin, streptomycin, and gentamicin against 20 strains of Listeria monocytogenes was studied in vitro. For all strains, the minimal bactericidal concentration (MBC) of both ampicillin and penicillin was much higher than the minimal inhibitory concentration (MIC). The MBC of both streptomycin and gentamicin was close to the MIC, but relatively high concentrations of these antibiotics were necessary to inhibit the growth of most of the strains of Listeria. The combination of penicillin plus streptomycin was synergistic against 19 of 20 strains and in the remaining strain produced enhanced killing (but of less magnitude than our criterion for synergism). Combinations of penicillin plus gentamicin, ampicillin plus streptomycin, and ampicillin plus gentamicin produced enhanced killing against all strains tested. No antagonism was observed when ampicillin or penicillin was combined with streptomycin or gentamicin.
157 citations
TL;DR: A method was developed for determination of the antibiotic susceptibility of anaerobic bacteria by use of a single-disc diffusion technique and incorporation of the inoculum in pour plates by correlation of zone diameters with minimal inhibitory concentrations determined in broth.
Abstract: A method was developed for determination of the antibiotic susceptibility of anaerobic bacteria by use of a single-disc diffusion technique and incorporation of the inoculum in pour plates. The method was standardized by correlation of zone diameters with minimal inhibitory concentrations determined in broth. Zone diameters could be used to approximate the minimal inhibitory concentrations of the seven antibiotics tested: ampicillin, bacitracin, carbenicillin, cephalothin, clindamycin, penicillin, and tetracycline.
147 citations
TL;DR: Of the anaerobic, nonsporulating, gram-negative bacilli, those of the genus Bacteroides are most frequently associated with serious infections in man, and all were resistant to the aminoglycosides, polymyxins, and semisynthetic penicillinase-resistant penicillins.
Abstract: Of the anaerobic, nonsporulating, gram-negative bacilli, those of the genus Bacteroides are most frequently associated with serious infections in man. Forty clinical isolates of the species Bacteroides fragilis were tested quantitatively against 24 antibiotics by an agar-dilution method under anaerobic conditions. Clindamycin, the most active antibiotic studied, had a median MIC of 0.19 ng/ml. Rifampin, erythromcyin, lincomycin, and chloramphenicol also inhibited all isolates in clinically attainable concentrations. More than half of the strains tested were resistant to tetracycline. Some isolates were susceptible to penicillin G, ampicillin, carbenicillin, and the cephalosporins, and all were resistant to the aminoglycosides, polymyxins, and semisynthetic penicillinase-resistant penicillins. The genus Bacteroides consists of nonsporulating, gram-negative bacilli which are obligate anaerobes. These organisms predominate numerically in the normal bacterial flora of the large bowel and are important components of the normal flora of the oral cavity and the urogenital tract [1]. Although they have long been recognized as significant human pathogens, the literature on infec
137 citations
TL;DR: The Venereal Disease Branch, Center for Disease Control, in a cooperative study has reevaluated the comparative efficacy of antibiotic schedules for the treatment of early syphilis in 586 patients, finding the 30-gm schedule of erythromycin base proved as effective as tetracycline and penicillin G.
Abstract: The Venereal Disease Branch, Center for Disease Control, in a cooperative study has reevaluated the comparative efficacy of antibiotic schedules for the treatment of early syphilis in 586 patients. All parenteral penicillin, tetracycline, and erythromycin treatment schedules recommended by the Public Health Service were studied. Erythromycin in base form, 20 gm, was given in a divided-dose schedule over a ten-day period. Subsequently, the dose of erythromycin had to be raised to 30 gm because of a high failure rate. All penicillin schedules tested showed a satisfactory cure rate with a cumulative re-treatment rate of only 10% in the 24-month observation period. The 30-gm schedule of erythromycin base proved as effective as tetracycline and penicillin G.
130 citations
TL;DR: Oral therapy with adequate parental counseling is as efficacious as intramuscular injection in children with streptococcal pharyngitis.
Abstract: Of 300 children with streptococcal pharyngitis, one group received a mixture of penicillin G procaine and penicillin G benzathine; a second was given a prescription for ten days of penicillin phenoxymethyl (parents of this group were given no special instructions); and a third was given identical prescriptions but their parents received specific counseling on the importance of taking the medication. There were 14 treatment failures plus relapse in group 1, 25 in group 2, and 10 in group 3. Compliance in taking penicillin was 58% in group 2 and 80% in group 3, a significant difference. Oral therapy with adequate parental counseling is as efficacious as intramuscular injection.
116 citations
102 citations
TL;DR: Membranes of Bacillus subtilis to which [14C]penicillin G had been bound were fractionated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate to identify the major penicillin-binding component, V, which was identified as the d-alanine carboxypeptidase, whose activity is not vital for the cell.
TL;DR: The yoghurt isolates were more resistant to streptomycin and more susceptible to penicillin than the cheese starters, and the 2, 3, 5, 5-triphenyltetrazolium chloride test, using Streptococcus thermophilus BC as assay organism, does not detect low levels of strePTomycin in milk, however, it is useful in detecting cloxacillin residues.
Abstract: Eight single-strain lactic streptococci, three commercial cheese starters, and six lactic acid bacteria isolated from yoghurt were examined for their susceptibility to penicillin, cloxacillin, tetracycline-hydrochloride and streptomycin. The ranges of the antibiotics causing 50% inhibition of the bacteria were (μg/ml): penicillin, 0.009 to 0.20; cloxacillin, 0.24 to 2.50; tetracycline, 0.09 to 0.60; and streptomycin, 0.35 to 13.0. The average concentrations required to cause 50 and 100% inhibition of the cheese starters were (μg/ml): penicillin, 0.12 and 0.26; cloxacillin, 1.91 and 3.9; tetracycline-hydrochloride, 0.13 and 0.36; and streptomycin, 0.59 and 2.06. All the cocci were about equally susceptible to tetracycline, and all organisms were more resistant to cloxacillin than penicillin. The yoghurt isolates were more resistant to streptomycin and more susceptible to penicillin than the cheese starters. The 2, 3, 5-triphenyltetrazolium chloride test, using Streptococcus thermophilus BC as assay organism, does not detect low levels of streptomycin in milk. However, it is useful in detecting cloxacillin residues.
TL;DR: Cell wall preparations of Staphylococcus aureus catalyse in vitro peptidoglycan synthesis from UDP-GlcNAc, UDP-MurNAc-pentapeptide and glycine without the addition of soluble tRNA and glycyl-tRNA synthetase.
TL;DR: In a group of elderly patients with normal serum creatinine, penicillin T/2 was prolonged due to age‐dependent decrease in renal function, and the effect of several drugs on the active renal tubular transport mechanism of Penicillin was studied.
Abstract: The half-life (T /2) of penicillin in blood was determined in 61 patients. An inverse relationship of penicillin T/2 and endogenous creatinine clearance was found. In a group of elderly patients with normal serum creatinine, penicillin T/2 was prolonged due to age-dependent decrease in renal function. The effect of several drugs on the active renal tubular transport mechanism of penicillin was studied. Probenecid increased penicillin T/2 from an average of 40.4 to 104.3 minutes. Penicillin T/2 in the younger patients using probenecid was of the same order as penicillin T/2 in elderly individuals not using probenecid. Phenylbutazone increased penicillin T/2 almost as much as did probenecid. Sulfinpyrazone, acetylsalicylic acid, indomethacin, and sulfaphenazole in therapeutic doses increased penicillin T /2 to a smaller degree. There was no significant change in penicillin T /2 after therapeutic doses of chlorothiazide, sulfamethizole, and sulfamethoxypyridazine.
TL;DR: The possibility of in vivo synergism of various commonly used antibiotic combinations should be further investigated since many patients with listeriosis receive such combinations for broad antibacterial coverage until the specific etiologic diagnosis is made.
TL;DR: The capacity of rifampin to eradicate staphylococci from pus in vitro and from abscesses in mice appears to be related to the ability of r ifampsin to kill intraleukocytic bacteria.
Abstract: Bacteria surviving within leukocytes are protected from the lethal action of high concentrations of most antibiotics, which may explain, in part, the failure of bactericidal antibiotics to eradicate staphylococci from abscesses. Since rifampin is unique in its ability to kill intraleukocytic bacteria, the efficacy of this drug was tested in the treatment of staphylococcal infections in mice. Groups of mice infected intravenously with Staphylococcus aureus were treated with rifampin (20 mg/kg), procaine penicillin (937.5 mg/kg), or methicillin (200 mg/kg). All untreated mice died with disseminated visceral abscesses. After 10 days of therapy, survival in groups treated with penicillin and methicillin was 16 and 20%, respectively, whereas with rifampin it was 80% (P < 0.0005). Antibiotic concentrations in the serum of mice treated with penicillin, methicillin, or rifampin were bactericidal for the strain of S. aureus used. Serial bacterial counts of kidney, lung, and spleen homogenates showed that neither penicillin nor methicillin was able to eradicate staphylococci, whereas rifampin completely sterilized those organs in many mice. When abscess contents and infected peritoneal washings were incubated with high concentrations of penicillin, methicillin, or rifampin, only rifampin killed all of the bacteria. The capacity of rifampin to eradicate staphylococci from pus in vitro and from abscesses in mice appears to be related to the ability of rifampin to kill intraleukocytic bacteria.
TL;DR: The in vitro susceptibility of 43 strains of Clostridium perfringens to nine antibiotics was determined by a standardized test for rapid-growing anaerobes, and good correlation was established between the agar dilution susceptibility and the disc diffusion susceptibility results.
Abstract: The in vitro susceptibility of 43 strains of Clostridium perfringens to nine antibiotics was determined by a standardized test for rapid-growing anaerobes. Good correlation was established between the agar dilution susceptibility and the disc diffusion susceptibility results. The inhibition zone diameters around the antibiotic discs, however, were generally much smaller than those of gram-negative anaerobes previously studied. All of the strains tested were susceptible in vitro to chloramphenicol, clindamycin, doxycycline, minocycline, penicillin, and vancomycin. Erythromycin showed poor in vitro activity against this organism, with only 7% of the strains susceptible, 72% intermediate in susceptibility, and 21% resistant. In tests of the 43 strains against lincomycin, 58% were susceptible, 32.5% were intermediate in susceptibility, and 9.5% were resistant. Against tetracycline, 37% of the strains were intermediate in susceptibility and the rest were susceptible.
TL;DR: Amoxicillin is a new semisynthetic penicillin which is active in vitro against gram-positive cocci and most isolates of Proteus mirabilis and Escherichia coli.
Abstract: Amoxicillin is a new semisynthetic penicillin which is active in vitro against gram-positive cocci (except penicillin G-resistant Staphylococcus aureus) and most isolates of Proteus mirabilis and Escherichia coli. Its in vitro activity is quite similar to ampicillin, but it produces higher serum levels after oral administration. The mean peak serum levels of amoxicillin in 11 normal volunteers were 2.30 mug/ml after 125 mg, 3.43 mug/ml after 250 mg, 6.75 mug/ml after 500 mg, and 9.90 mug/ml after 1 g. About 70% of the drug was excreted in the urine during the first 6 hr.
TL;DR: Resistance to penicillin is usually associated with resistance to tetracycline erythromycin chloramphenicol fusicid acid rifampicin ethidium bromide and acridine orange and Fortunately spectinomycin or sulfa and trimethoprim therapy is effective against such multiple-drug resistant gonocci.
TL;DR: P Neisseria gonorrhoeae shows significant positive correlation of resistance to penicillin G and spectinomycin and treatment failures showed increased resistance to spect inomycin.
Abstract: Patients with uncomplicated gonorrhea received either 2.0 gm or 4.0 gm of spectinomycin hydrochloride or currently recommended doses of penicillin G procaine. Of 172 men reexamined within seven days after treatment of gonococcal urethritis, treatment failure rates were 17% for 2.4 mega units of penicillin G procaine, 0% for 2 gm of spectinomycin hydrochloride, and 3.4% for 4 gm of spectinomycin hydrochloride. Of 143 women, failure rates were 13% for 4.8 mega units of procaine penicillin G, 4.3% for 2 gm of spectinomycin hydrochloride, and 4.7% for 4 gm of spectinomycin hydrochloride. Pretreatment isolates of Neisseria gonorrhoeae from patients not cured with penicillin G procaine showed increased resistance to penicillin G ( P Neisseria gonorrhoeae shows significant positive correlation of resistance to penicillin G and spectinomycin ( P N gonorrhoeae from spectinomycin treatment failures showed increased resistance to spectinomycin.
TL;DR: The purpose of the reported studies was to investigate whether the principle of specific hapten inhibition is used to demonstrate antibody specificity in vitro and whether this pri
Abstract: The principle of specific hapten inhibition is classically used to demonstrate antibody specificity in vitro . The purpose of the reported studies was to investigate whether this pri
TL;DR: Cephalexin does not appear to have any nephrotoxic effects and thus may be used in patients with renal failure, and is much less bound to serum proteins than cephalothin.
Abstract: Synopsis: Cephalexin2 is an orally active semisynthetic derivative of the cephalosporin nucleus (7-amino cephalosporanic acid) with a spectrum of activity against both Gram-positive and Gram-negative bacteria. The side chain substituents on the cephalosporin nucleus of cephalexin are the same as the substituents on the penicillin nucleus (6-amino penicillanic acid) of ampicillin. Cephalexin is advocated for the treatment of infections of the upper and lower respiratory tract, genitourinary system, skin and soft tissue, bones and joints and certain other infections due to susceptible organisms. In concentrations which are achieved with usual oral doses, cephalexin is bactericidal against most susceptible organisms. Its activity in vitro is generally less than that of cephaloridine or cephalothin against susceptible organisms, and less than that of ampicillin against ampicillin-sensitive bacteria, notably Enterobacteriaceae and Haemophilus influenzae. Cephalexin does however, attain much higher serum concentrations than ampicillin in equivalent oral doses and is much less bound to serum proteins than cephalothin. Whether such pharmacokinetic differences make cephalexin comparable in therapeutic efficacy with ampicillin (particularly against H. influenzae infections) and cephalothin, remains to be established. Successful therapeutic results have however, been obtained with doses of 1 to 4 g daily (usually given at intervals of 6 hours), particularly in acute infections. The published experience on long-term administration in chronic cases is limited, as are direct comparisons with penicillin, ampicillin and the penicillinase-resistant penicillins. Tolerance is good, although diarrhoea, vomiting and vulvo-vaginitis have occasionally been troublesome. Cephalexin does not appear to have any nephrotoxic effects and thus may be used in patients with renal failure.
TL;DR: The pH-stat alkalimetric titration method was shown to be applicable and superior to other chemical methods in the investigation of β-lactamase activity as well as in kinetic studies.
TL;DR: It is suggested that the transpeptidases(s) and the d-alanine carboxypeptidase are separate enzymes, and that the cross-linking reaction by cloxacillin appeared to be fully reversible.
TL;DR: Spectinomycin hydrochloride, a new parenteral antibiotic prepared from Streptomyces spectabilis, was compared with standard U.S. Public Health Service-recommended dosages of aqueous procaine penicillin G in the treatment of uncomplicated gonorrhea in 353 men and 314 women and resulted in cure rates in excess of 90%.
Abstract: Spectinomycin hydrochloride, a new parenteral antibiotic prepared from Streptomyces spectabilis, was compared with standard U.S. Public Health Service-recommended dosages of aqueous procaine penicillin G in the treatment of uncomplicated gonorrhea in 353 men and 314 women. Of the 314 women, 130 had a pretreatment positive rectal culture. All diagnoses were proven by culture on Thayer-Martin selective medium. Minimal inhibitory concentrations of both drugs were determined. Single doses of 2 and 4 g of spectinomycin were compared with 2.4 million units of procaine penicillin in males and with both 2.4 and 4.8 million units of procaine penicillin in females. Both spectinomycin schedules, 2.4 million units of penicillin in males and 4.8 million units of penicillin in females, resulted in cure rates in excess of 90%. There were no failures at the rectal site only in those women with positive rectal cultures. There was no advantage to using the larger amount of spectinomycin in either sex.
TL;DR: Antiglobulin testing revealed IgG, C3, C4 and C5 on the erythrocytes in a case of penicillin-induced, immune hemolytic anemia, and the survival times of autologous and of normal ery Throcytes, measured concomitantly, were both shortened.
Abstract: Antiglobulin testing revealed IgG, C3, C4 and C5 on the erythrocytes in a case of penicillin-induced, immune hemolytic anemia. When no penicillin was in the patient's serum, the survival times of autologous and of normal erythrocytes, measured concomitantly, were both shortened (half-time of 21 days). Antibody specific for penicillin was eluted from patient erythrocytes. On addition of eluate to a mixture of normal B cells coated with penicillin and O cells in the presence of complement, C3, but not IgG, was bound to the O cells. Addition of eluate and complement to a mixture of O erythrocytes treated with 2-amino-ethylisothiouronium bromide and penicillin-coated B cells resulted in hemolysis of the O cells. Two mechanisms of erythrocyte destruction are possible: the IgG, complement-binding, antipenicillin antibody causes destruction of patient erythrocytes coated in vivo with penicillin; and, in the absence of detectable serum penicillin, normal erythrocytes may be destroyed because they bind ac...
TL;DR: A strain of Staph.
Abstract: Summary
A strain of Staph. aureus isolated from an infected wound showed firmly linked resistance to penicillin and kanamycin. Variants sensitive to both these antibiotics were produced spontaneously and at a high frequency during storage for a few days at ambient temperature.
Both sensitive and resistant variants produced a highly coloured diffusible pigment.