Comparative study of the semisynthetic penicillins in the experimental therapy of pneumococcal and streptococcal infections in mice]

Penicillins were studied comparatively on mice with infections caused by pneumococci and streptococci. It was shown that klomethacillin was superior by its chemotherapeutic effect to other penicillins in treatment of pneumococcal septicemia when used subcutaneously or intragastrically. Ampicillin was superior in treatment of streptococcal infection.     

Distribution of sulfanilamides and penicillins in the blood and organs of rats after their combined administration

The use of benzylpenicillin and ampicillin in combination with sulfalen or sulfadimethoxine increased the levels of the penicillins and sulfalen in some organs and tissues of rats. This was accompanied by a rise in the concentration gradients of the drugs. It is concluded that the combined use of the penicillins and sulfanilamides determines their increased penetration from the blood into other organs and tissues of the host.     

Combined antibiotic therapy following heart surgery

In vitro efficacy of combinations of broad and narrow spectrum semi-synthetic penicillins, broad spectrum semi-synthetic penicillins with macrolides or aminoglycosides and tetracyclines with other biosynthetic antibiotics was studied with respect to the causative agents of surgical infections. Correlation between the sensitivity of the isolates and the antibiotics levels in the organism of the surgical patients was shown. The role of the etiological factor in the development of the post-operative complications in the patients after surgical operations on the heart was elucidated. The most rational schemes of the antibiotic use in therapy of the patients with purulent complications after operations on the open heart were developed and the maximum doses of different semi-synthetic penicillins for the treatment of patients with purulent processes after operations under conditions of artificial blood circulation were determined.     

State of the blood coagulating system in the treatment of puerperal infections using semisynthetic penicillins and cephaloridine]

The effect of some semi-synthetic penicillins, such as methicillin and oxacillin and cephalosporings, such as cephaloridin on the condition of the blood coagulation system in 85 patients with postnatal mastitis and endomyometritis was studied. It was shown that the above antibiotics had no significant effect on the parameters of the blood coagulating system. A decrease in the fibrinogen level was found in the mastitis patients treated with semi-synthetic penicillins and cephaloridin. An increase in the prothrombins index in the patients treated with methicillin oxacillin was shown. The use of the semi-synthetic penicillins and cephaloridin for the therapy of the puerpera with endomyometritis resulted in prolongation of the recalcification period. A decrease in the fibrinolytic activity most pronounced in therapy with cephaloridin was also found. Therefore, the above changes in the blood coagulating system of the puerpera with postnatal infections subjected to short-term treatment courses were insignificant and required no special correction.     

Comparison of assay techniques for beta-lactamase activity

Two chemical, one physical and two microbiological techniques for the assay of β-lactamase activity have been compared using three partially purified β-lactamases of different specificities. Seven cephalosporins and three penicillins with a wide range of susceptibilities have been used as substrate. The different methods gave results that were in general agreement with the exception of the hydroxylamine assay. The cephalosporins were most rapidly assayed by the uv method. Its suitability for use in the assessment of new cephalosporin analogues was confirmed, but it could not be used for penicillins. The iodometric assay was rapid and reliable but required large amounts of substrate. Where the amount of substrate available was limited, the microbiological techniques were preferred. The results obtained for enzyme activities against two of the cephalosporins and against the penicillins were higher with the hydroxylamine assay than with the other methods and it had no apparent advantage.     

Activity of Selected Penicillins In Vitro and in Experimental Bacterial Infections in Mice

The minimal inhibitory concentration and the 50% mouse protective dose for five key penicillins are presented. Such data provide a useful guide in evaluating the activity of new penicillins, in comparison with those already commercially available, and establishes the amounts of antibiotic necessary to obtain a PD(50) for several experimental model infections in mice.     

Detection and side-chain specificity of IgE antibodies to flucloxicillin in allergic subjects

Unlike studies on the antigenicity of penicillins in laboratory animals, limited information is available on the allergenicity of penicillins in man, especially with regard to fine structural allergenic differences between the many different penicillins. Inconsistent with the earlier conclusions of others, our studies suggest that side-chain structures to flucloxacillin-reactive IgE antibodies. Quantitative hapten inhibition studies revealed potent inhibition by flucloxacillin and three structurally related penicillins: oxacillin, cloxacillin and dicloxacillin. Analysis of the results showed that the side-chain group of flucloxacillin, 3-2(-chloro-6-fluorophenyl)-5-methyl-4-isoxazolyl, is recognized by some antibodies and that the 5-methyl-3-phenyl-4-isoxazolyl group, with or without halogen substituents, accounts for the reactivity of other antibodies and for the cross-reactions seen with some other penicillins. Since it is the side-chain group that distinguishes the many different types of penicillin, and since IgE antibodies in many of the allergic reactions recognize the side-chain groups, it is becoming clear that specific assays are required for the detection of IgE antibodies to each of the different penicillins.     

Detection of allergy to antibiotics in dermatology--venereology practice

A total of 205 stationary patients with and without drug disease were examined with the purpose of diagnosing allergy to the widely used antibiotics. The reaction of leucocytosis was used in the studies and the antibiotic concentration was increased up to 1 gamma/ml. Sufficiently high specificity of the reaction for diagnosis of the medicamentous allergy was determined. Increased sensitivity was most frequent to penicillins. Participation of biologically active substances, such as heparin and histamine in exacerbation reaction in syphilitic patients treated with penicillin was found. The most pronounced increase in the levels of these substances in the blood of the patients was observed 6 hours after the beginning of the treatment without any connection without any connection with the clinical signs of the exacerbation reaction.     

Dicloxacillin: its chemotherapeutic action and experimental kinetic characteristics]

Activity against 50 clinical staphylococcal strains, chemotherapeutic efficiency, absorption and distribution of dicloxacillin in animals were studied in comparison with oxacillin. It was found that dicloxacillin was superior to oxacillin with respect to a number of their properties. The antibiotic was characterized by a higher antistaphylococcal activity, especially with respect to methicillin resistant strains. It was more effective in treatment of staphylococcal pneumonia and septicopiemia of albino mice. The drug was better absorpted when used orally and was detected in the blood in therapeutic concentrations for long periods of time. The antibacterial titer of the blood serum after dicloxacillin administration was 4 times higher than that of oxacillin.     

Pharmacokinetics of penicillins in the blood of dogs administered the combination preparation, ampiox, internally]

The pharmacokinetics of penicillins in the blood of dogs treated with ampiox, a combination of ampicillin and oxacillin at a ratio of 1 : 1 was studied. The drug was administered orally in single or repeated doses of 25, 50 and 100 mg/kg. The maximum levels of ampicillin in the blood serum were observed 1 hour after a single administration of the drug. The therapeutic concentrations of the antibiotic were preserved for 6 hours, its value being depended on the dose used. The maximum concentration of oxacillin was detected 1 hour after the drug administration in various doses and it was preserved in the blood at the therapeutic levels for 3 hours. The dynamics of circulation of ampicillin and oxacillin administered separately did not differ from that established for the use of ampiox. The regularities of the pharmacokinetics of ampiox on its repeated use remained practically unchanged.     

Updating the side effects of the penicillins

Use of the penicillins in patients may result in a variety of side effects in addition to the well known occasional allergic reactions. Some of these side effects may be quite serious. Treatment with the various penicillins, expecially in the large amounts presently prescribed, may be attended by immunologic reactions, such as nephritis, and by direct toxic effects which may involve the blood platelets, the neurones of the central nervous system, and perhaps the parenchymal cells of the liver.     

Propionibacterium acnes in the etiology of endocarditis]

Propionibacterium acnes is the gram positive anaerobic bacteria belongs to the normal skin and oral microbial flora. The participation of this microorganism in the infective endocarditis is still controversial. The aim of the study was to perform the diagnostic and therapeutic difficulties in 5 patients with infective endocarditis caused by Propionibacterium acnes. In 3 out of 5 patients the infective endocarditis developed after prosthesis valve replacement, in 2 others on the native valves. The inserted prostheses were mechanical ones, propionibacterium acnes was identified as causative organisms in all of the causes (two positive blood and/or valve culture). The bacterial strains were sensitive to the antibiotics as: penicillins, cephalosporins, clindamycin, and vancomycin, however cephalosporins used at the beginning of the treatment in 3 patients and clindamycin in 1 patient had limited clinical efficacy. Later treatment with timentin, augmentin and tienamycin was successful in 3 patients; one patient was cured with vancomycin. One patient died because of septic, embolic complication in early stage of illness. We conclude the effectiveness of penicillins in combination with clavulanic acid and tienamycin in therapy of infective endocarditis due to Propionibacterium acnes. The treatment should be lasted during 4-6 weeks.     

Use of the penicillanic acid formation reaction for the analysis of penicillins. The quantitative determination of oxacillin]

A procedure for quantitative determination of oxacillin by means of spectrophotometry is described. The procedure is based on the capacity of penicillins to transform on heating in acid buffer solutions containing copper ions into respective penicillenic acids having specific absorption characteristics in the UV-spectrum region. The amount of oxacillin was estimated by the optical density of the solutions at a wave length of 335 nm corresponding to the absorption maximum of the penicillenic acid of oxacillin. The optimal conditions for the reaction of the penicillenic acid formation, i.e. pH of the buffer solution and the level of the copper ions in it, time and temperature of heating were determined. The data on the comparison of the specificity and reproducibility of the new method with the currently used ones for determination of oxacillin are presented.     

Cloning and expression in Escherichia coli of isopenicillin N synthetase genes from Streptomyces lipmanii and Aspergillus nidulans.

beta-Lactam antibiotics such as penicillins and cephalosporins are synthesized by a wide variety of microbes, including procaryotes and eucaryotes. Isopenicillin N synthetase catalyzes a key reaction in the biosynthetic pathway of penicillins and cephalosporins. The genes encoding this protein have previously been cloned from the filamentous fungi Cephalosporium acremonium and Penicillium chrysogenum and characterized. We have extended our analysis to the isopenicillin N synthetase genes from the fungus Aspergillus nidulans and the gram-positive procaryote Streptomyces lipmanii. The isopenicillin N synthetase genes from these organisms have been cloned and sequenced, and the proteins encoded by the open reading frames were expressed in Escherichia coli. Active isopenicillin N synthetase enzyme was recovered from extracts of E. coli cells prepared from cells containing each of the genes in expression vectors. The four isopenicillin N synthetase genes studied are closely related. Pairwise comparison of the DNA sequences showed between 62.5 and 75.7% identity; comparison of the predicted amino acid sequences showed between 53.9 and 80.6% identity. The close homology of the procaryotic and eucaryotic isopenicillin N synthetase genes suggests horizontal transfer of the genes during evolution.     

Inhibition of the β-lactamases of Escherichia coli and Klebsiella aerogenes by semi-synthetic penicillins

1. A new automated micro-iodometric method is described for screening compounds for inhibitory action against beta-lactamase enzymes. 2. Over 1000 semi-synthetic penicillins were tested for inhibitory activity against the beta-lactamase of Escherichia coli B11 and 18 showed a fractional inhibition similar to or higher than that of methicillin. 3. The best inhibitors were alkoxy- and halogen-substituted phenyl-, naphthyl- or quinolyl-penicillins. 2-Isopropoxy-1-naphthylpenicillin (BRL 1437) was clearly the best and had a K(i) value about 1% of that of methicillin. 4. The inhibition of the beta-lactamase of E. coli B11 by BRL 1437 was shown to be reversible and competitive. The K(i) was 0.004mum and K(i)/K(m) with ampicillin and p-hydroxyampicillin (BRL 2333) was about 0.0001. The K(m) and V(max.) values were determined for the beta-lactamases of E. coli B11 and Klebsiella aerogenes A against a variety of penicillins. Cell-bound and solubilized enzymes gave similar K(i) and K(m) values. 5. BRL 1437 was superior to cloxacillin and methicillin for inhibition of the beta-lactamase of live, fully grown cultures of several strains of E. coli and K. aerogenes. Of a group of inhibitors BRL 1437 was the most stable to the beta-lactamase of E. coli B11.     

A comparison of methods used for the separation of fish lymphocytes

A comparison is made of methods currently used in separating mammalian lymphocytes from whole blood when adapted for use with fish blood. The methods give good results but do require minor modifications. The use of Ficoll-Paque, although requiring greater expertise, did result in obtaining good recovery rates of lymphocytes in a viable condition. The separation of cells without the addition of agents other than culture medium, while resulting in good yields of lymphocytes, was much more variable and did not result in the separation of such a pure cell line. The other methods compared were found to be unsuitable for fish blood.     

Evidence for the involvement of arginyl residue at the active site of penicillin G acylase from Kluyvera citrophila

Penicillin G acylase (PGA) is used for the commercial production of semi-synthetic penicillins. It hydrolyses the amide bond in penicillin producing 6-aminopenicillanic acid and phenylacetate. 6-Aminopenicillanic acid, having the beta-lactam nucleus, is the parent compound for all semi-synthetic penicillins. Penicillin G acylase from Kluyvera citrophila was purified and chemically modified to identify the role of arginine in catalysis. Modification with 20 mM phenylglyoxal and 50 mM 2,3-butanedione resulted in 82% and 78% inactivation, respectively. Inactivation was prevented by protection with benzylpenicillin or phenylacetate at 50 mM. The reaction followed psuedo-first order kinetics and the inactivation kinetics (V(max), K(m), and k(cat)) of native and modified enzyme indicates the essentiality of arginyl residue in catalysis.     

Studies on Trypanosoma vivax: comparison of parasitological diagnostic methods.

Leeflang P., Buys Janny and Blotkamp Coby. 1978. Studies on Trypanosoma vivax: comparison of parasitological diagnostic methods. International Journal for Parasitology8: 15–18. Parasitological methods for the diagnosis of Trypanosoma vivax infections in Nigerian cattle, including thin and thick blood smear and lymph gland smear examination, haematocrit centrifuge technique, hypotonie lysis test and mouse inoculation were evaluated. In 155 blood samples, thick film examination was significantly better than thin smear examination; in 126 samples, the haematocrit centrifuge technique was significantly superior over thin smear but not over thick film examination; when all six methods were applied in 52 samples, significant differences could only be demonstrated between mouse inoculation on one hand and thick film and gland smear examination, haematocrit centrifuge technique and hypotonie lysis test on the other hand, and between thin smear examination and hypotonic lysis test. It was shown that none of the tests was either satisfactory or sufficiently reliable to be used alone. The combination of either haematocrit centrifuge technique or thick film examination together with thin smear examination is recommended as most practical for the diagnosis of T. vivax infection under field conditions. The haematocrit centrifuge technique is also more advantageous because simultaneous estimation of the packed cell volume will evaluate the clinical condition of the herd. A comparison of the value of diagnostic methods for East and West African T. vivax was included in the present study.     

Advances in enzymatic transformation of penicillins to 6-aminopenicillanic acid (6-APA)

This article elaborates on the important recent developments in the enzymatic transformation of penicillins to 6-aminopenicillanic acid (6-APA), which is the basic raw material for the industrial production of semisynthetic penicillins such as amoxycillin and ampicillin. Particular emphasis is placed on the improvements in purification, stability, and immobilization of the enzymes, (i.e. penicillin acylases) used for these transformations.     

Antipseudomonal Activity of α-Sulfoaminopenicillins

A series of penicillins characterized by the presence of a sulfoamino or a modified sulfoamino group in the side chain was subjected to in vitro antimicrobial screening tests. Although the most potent members of the series were less active than benzylpenicillin against gram-positive bacteria and comparably active against most gram-negative bacteria, they were, on the average, 8 to 16 times more effective against strains of Pseudomonas aeruginosa. In other comparative laboratory tests against P. aeruginosa, these compounds were about as active as carbenicillin and four to eight times more active than ampicillin. An examination of structure-activity relationships indicated that maximal potency was obtained with penicillins having an alpha-(aromatic or heteroaromatic)-alpha-sulfoaminoacetamido side chain. The compound with an alpha-phenyl group was comparable in activity to those having an alpha-(2- or 3-thienyl) group, whereas any modification in position or structure of the alpha-sulfoamino group reduced activity. Results of studies with a cell-free P. aeruginosa beta-lactamase suggest that the marked inhibitory effects of alpha-sulfoamino penicillins for P. aeruginosa can be attributed, at least in part, to their high degree of resistance to this enzyme. Some derivatives, however, had weak antipseudomonal activity, despite possessing a high degree of beta-lactamase resistance.