In vivo conversion of penicillin N into a cephalosporin type antibiotic by a non-producing mutant of Streptomyces clavuligerus

Summary Intact mycelia of beta-lactam antibiotic producing microorganisms are generally considered to be impermeable to externally fed penicillin. Using growing cells of the non-producing mutant. Streptomyces clavuligerus NP1, it was surprisingly possible to convert externally fed penicillin N into a cephalosporin type of antibiotic.Dedicated to Professor Dr. H. J. Rehm on the occasion of his 60th birthday.     

Pediatric grand rounds: a tribute to Norman J. Siegel, M.D

At ceremonies held in Baltimore Maryland on May, 4, 2002, Dr. Howard A Pearson, Professor of Pediatrics, was awarded the John A. Howland award of the American Pediatric Society, probably the most prestigious award of American Pediatrics. Dr. Pearson had been nominated for the award by Dr. Norman Siegel. The Department of Pediatrics Grand Rounds on Wednesday noon, October 26, 2002 was originally scheduled as a repetition of the presentation by Dr. Siegel and the acceptance by Dr. Pearson for those who could not be in Baltimore. However; in a number of meetings, unknown to Dr. Siegel, it was unanimously decided that it would be very appropriate to instead honor him as he stepped down from his position as Vice- and Interim Chairman of Pediatrics, and to formally thank him for his long and faithful service to the Department of Pediatrics, the Yale University School of Medicine, and the Yale New Haven Hospital.     

Herbert Tabor (1918–1920): obituary.

This invited Letter commemorates the life and scientific legacy of Dr. Herbert Tabor (1918–1920), a leading scientist at the National Institutes of Health in Bethesda Maryland and former Chief Editor of the Journal of Biological Chemistry.

Dr. Herbert Tabor in his second floor laboratory of Building 8 taken in 2005 (photo credit Dr. Harry Saroff).Herbert Tabor was born in New York City on November 28th, 1918, at the start of the “Spanish Flu” pandemic. After attending public schools in the city, he matriculated in 1935 to Harvard College, where he studied biochemical science and he entered Harvard Medical School in 1937. In his final year, Herb worked in the Department of Biological Chemistry with A. Baird Hastings to determine the ionization constant of MgHPO4. This work was published in The Journal of Biological Chemistry, marking the beginning of his long involvement with the journal.After graduation in 1942, Herb held an internship at Yale-New Haven Hospital, where he engaged in some laboratory work in clinical chemistry. While there, Herb performed the first therapeutic injection of penicillin in the USA, rapidly curing the patient of severe septicemia. The country being at war, in January 1943, he was commissioned in the US Public Health Service and served as medical officer on a US Coast Guard cutter, which was providing escort service to North Atlantic convoys. The following September, he was transferred to The National Institutes of Health, which had just moved to a new site in Bethesda Maryland, then a small town outside of Washington D.C. Herb was assigned to work with Sanford Rosenthal, who was interested in the electrolyte imbalance response to trauma and burn injuries and how these might be treated by administration of saline solution. In 1946, Herb married Celia White, who he had met in Boston, some years earlier. That same year, he helped form a lunch time seminar group to discuss the biochemical literature. Founding members included other biochemist luminaries such as Leon Heppel, Bernie Horecker and Arthur Kornberg.Meetings were held every day and the seminar lasted for many years through many changes in participants. In the early 1960’s, during a casual conversation at the seminar, Herb was surprised to discover the origin of the penicillin which he had administered in 1942. It had been prepared by an NIH colleague, Gil Ashwell, who had worked at Merck at the time. The drug was considered so precious, that Gil also had the job of its recovery from the patient’s urine. Herb and Celia moved into commissioned officer housing, conveniently located on the NIH campus in 1949. This was just 10 min from the laboratory. This is where they raised their family and stayed for over 70 years. Celia left George Washington University in 1952 and joined Herb at NIH. They began their work together on the biosynthesis, function and genetics of polyamines in normal and cancerous cells. This would occupy the rest of their careers. Sanford Rosenthal retired in 1961 and Herb took over as chief of the Laboratory of Biochemical Pharmacology, NIAMD (as it then was). He held this position until 1999.It is impossible to write about Herb Tabor without remembering his long association with The Journal of Biological Chemistry. He served on the editorial board from 1961 to 1966 and was appointed as an executive editor in 1968. Following the resignation of William Stein, he was promoted to editor in chief in 1971. Herb was devoted to all aspects of publishing the journal, though he did say that he was pleased that restrictions on his primary role as a civil servant got him out of many telephone calls from disgruntled authors. During his tenure, the annual output of published papers increased more than fourfold, with accompanying increases in the size of the editorial board. He was the moving force behind changing the journal to an electronic format. Initially this involved parallel publication of papers on CD-ROM in 1992. Finally, in 1995 the journal was moved onto the internet. J. Biol. Chem. was one of the first biological journals to make this move. Herb stood down as executive editor in 2010, assuming the title of co-editor.During his career, Herb received many prestigious awards. Notably, in 1971, he was elected to the American Academy of Arts and Sciences, in 1977, to the National Academy of Sciences and in 1986, the Hillebrand Award from the American Chemical Society. Montgomery County, MD recognized his scientific achievements, by naming November 28th 2018, his hundredth birthday, as Dr. Herbert Tabor Day. Celia retired from NIH in 2005 and died in 2012. Herb never talked about retirement. Publishing his last scientific paper in 2019 (Keller et al. 2019) he passed away in his sleep on August 20th 2020, at his home on the NIH campus. He is survived by his four children, Edward, Marilyn, Richard and Stanley, together with 10 grandchildren and 6 great-grandchildren.     

Septic arthritis and osteomyelitis from a cat bite

A 39-year-old man with no prior history of underlying arthritis developed osteomyelitis and septic arthritis in his hand following a cat bite. This case illustrates the virulence of Pasteurella multocida infections associated with animal bites, particularly those of cats, whose teeth can inoculate bone directly. The onset of cellulitis caused by P. multocida infections is often rapid, and the drug of choice for such infections remains penicillin. Appropriate antibiotic therapy, however, does not always prevent complications such as those seen in this patient.     

Differentiation of mycoplasmatales from bacterial protoplast L-forms by assay for penicillin binding proteins

Membrane proteins with the specific ability for binding penicillin with high affinity (penicillin binding proteins) were found to be present in two strains of the cell wall-less protoplast L-form of P. MIrabilis and were absent from different species of Mycoplasma and from Acholeplasma laidlawii. Thus, the assay for penicillin binding proteins appeared to be suitable for the differentiation of the cell wall-less procaryotes. The absence of penicillin binding proteins from the mycoplasmatales further confirmed the unrelatedness of this group to the bacteria.Non-Standard Abbreviation PBP penicillin binding protein Dedicated to Professor Dr. Otto Kandler on the occasion of his 60th birthday     

Hubert Lynes:A Biographical Sketch

O rnithology has suffered a grievous loss by the death of Rear-Admiral Hubert Lynes, which occurred after a short illness at a Naval Hospital in Wales on 10 November, 1942, a few days before his sixty-eighth birthday. Those who knew him will remember him not alone for his talents and achievements, but as a man of exceptional character and as an ever faithful friend and good companion.     

Antibiotic Therapy of Staphylococcal Infections

The antibiotic treatment of staphylococcal infections remains a problem. Isolation of the organism and sensitivity testing are necessary in the choice of antibiotic. Penicillin G is the most effective penicillin against non-penicillinase-producing staphy-lococci; for the penicillinase producers there is very little to choose between the semisynthetic penicillins, methicillin, cloxacillin, nafcillin and oxacillin. For patients who are hypersensitive to penicillin, the bacteriostatic drugs (erythromycin, novobiocin, tetracycline, chloramphenicol, oleandomycin) are useful for mild infections, while for more severe illness the bactericidal drugs (vancomycin, ristocetin, kanamycin, bacitracin, neomycin) have been used successfully. Acute staphylococcal enterocolitis is probably best treated by a semisynthetic penicillin. Other antibiotics which have been found useful, with clinical trials, for staphylococcal infections are cephalosporin, fucidin, cephaloridine and lincomycin. The latter drug has been reported of value in the treatment of osteomyelitis. There is little justification for the prophylactic use of antibiotics to prevent staphylococcal infection. Surgical drainage is still an important adjunct in the treatment of many staphylococcal infections.     

A festschrift for J. Martyn Bailey, a biochemist extraordinaire

A festschrift for Dr. John Martyn Bailey, Professor of Biochemistry and Molecular Biology was organized by the Biochemistry department of the George Washington University School of Medicine and Health Sciences on December 4-5, 2006 to honor his 48 years of contributions. He made important contributions in the areas of essential fatty acids, prostaglandins, thromboxanes and lipoxygenase metabolites.     

Rapid detection of bacterial hygromycin B phosphotransferase in Aspergillus niger transformants

Summary A rapid method is presented for determining in vitro the activity of bacterial hygromycin B phosphotransferase expressed in Aspergillus niger transformants. Even low amounts of this enzyme can be detected with this assay. In addition, there is evidence for a correlation between phosphotransferase activity and the level of resistance to high concentrations of the antibiotic hygromycin B in A. niger transformants.Dedicated to Prof. Dr. Dr. h. c. Karl Esser on the occasion of his 65th birthday     

Council Meeting Minutes, 529th Meeting, 25 February 1967

The following address was given by Dr. Cecil J. Watson at the Wm. J. Kerr Gold Headed Cane Lecture, University of California School of Medicine, on 9 June 1967. At this event on the eve of Commencement Day, the senior student who has been chosen by his classmates and by his professors in the Department of Medicine as the one who best exemplifies the qualities of a true physician is awarded a gold-headed cane.^* This carries on the British tradition of a similar cane that was passed from physician to physician from 1689 to 1825. The original cane, which was carried successively by Doctors John Radcliffe, Richard Mead, Anthony Askew, David Pitcairn and Matthew Baillie, now rests in the Hall of the Royal College of Physicians in London.     

The ineffectiveness of tobramycin combination therapy in Streptococcus faecium endocarditis.

A patient required mitral valve replacement following ineffective antibiotic treatment of enterococcal endocarditis caused by Streptococcus faecium. Endocarditis had relapsed despite therapy with ampicillin and tobramycin for six weeks. A second relapse had occurred following treatment with penicillin and gentamicin. Initial failure of antibiotic therapy may be related to the known lack of in vitro and in vivo synergy between penicillin and tobramycin against S. faecium. Effective therapy of enterococcal endocarditis requires considerations of bacterial speciation, determination of high-level aminoglycoside resistance, and preferably adequate antibiotic synergy studies to assure effective therapy.     

The global regulator LaeA controls penicillin biosynthesis, pigmentation and sporulation, but not roquefortine C synthesis in Penicillium chrysogenum

The biosynthesis of the beta-lactam antibiotic penicillin is an excellent model for the study of secondary metabolites produced by filamentous fungi due to the good background knowledge on the biochemistry and molecular genetics of the beta-lactam producing microorganisms. The three genes (pcbAB, pcbC, penDE) encoding enzymes of the penicillin pathway in Penicillium chrysogenum are clustered, but no penicillin pathway-specific regulators have been found in the genome region that contains the penicillin gene cluster. The biosynthesis of this beta-lactam is controlled by global regulators of secondary metabolism rather than by a pathway-specific regulator. In this work we have identified the gene encoding the secondary metabolism global regulator LaeA in P. chrysogenum (PcLaeA), a nuclear protein with a methyltransferase domain. The PclaeA gene is present as a single copy in the genome of low and high-penicillin producing strains and is not located in the 56.8-kb amplified region occurring in high-penicillin producing strains. Overexpression of the PclaeA gene gave rise to a 25% increase in penicillin production. PclaeA knock-down mutants exhibited drastically reduced levels of penicillin gene expression and antibiotic production and showed pigmentation and sporulation defects, but the levels of roquefortine C produced and the expression of the dmaW involved in roquefortine biosynthesis remained similar to those observed in the wild-type parental strain. The lack of effect on the synthesis of roquefortine is probably related to the chromatin arrangement in the low expression roquefortine promoters as compared to the bidirectional pbcAB-pcbC promoter region involved in penicillin biosynthesis. These results evidence that PcLaeA not only controls some secondary metabolism gene clusters, but also asexual differentiation in P. chrysogenum.     

From structure to solutions: the role of basic research in developing anthrax countermeasures: Microbiology Graduate Program Seminar: Anthrax toxin

Dr. John Collier traced the discoveries that elucidated the structure and function of the anthrax toxin in his talk "Anthrax Toxin," which was part of the Microbiology Graduate Program Seminar Series at Yale School of Medicine on February 23, 2012. Dr. Collier, Professor of Microbiology and Immunobiology at Harvard University, began by noting the advantages to studying anthrax pathogenesis in a biosafety level-1 lab. This designation does not merely facilitate his research, but also reflects a larger trend of basic research being leveraged to develop translational applications. Basic research on toxin structure has led to the development of a vaccine by Dr. Collier's group. Next-generation prophylactics also may stem from recent discoveries uncovering a role for cellular cofactors that mediate toxin function. Finally, basic research into the toxin substructure has facilitated efforts to change the receptor tropism to target dysregulated cells for therapeutic purposes. The urgency around biodefense agents makes the choice of research priorities a salient issue. As such, this author submits that basic research occupies a unique and lucrative niche driving clinical applications.     

The ethical dilemma of seeking appropriate CME sessions in February

Wet West Coast winter syndrome caused Dr. John Anderson to seek a continuing medical education (CME) conference in sunnier climes, and he found one that was not quite within his field of family medicine. He offers this litany of epiphany, confession and redemption to anyone else considering sacrificing CME content on the altar of CME location.     

Equilibria for the adsorption of antibiotics onto neutral polymeric sorbents: Experimental and modeling studies

The objective of this work was to study the equilibria for adsorption of three antibiotics (penicillin V, tetracycline, and cephalosporin C) from water onto commercially available neutral polymeric sorbents. The pH was observed to be an important factor in adsorption as our results suggest that the neutral forms of penicillin V and cephalosporin C are preferentially adsorbed onto the neutral sorbents. Also, sorbent surface chemistry was observed to be important for adsorption, as the antibiotics adsorbed more favorably (both in terms of affinities and enthalpies) onto the aromatic sorbent as compared to the aliphatic ester sorbent. In addition to these thermodynamic measurements, molecular modeling studies and Monte Carlo simulations suggest that adsorption onto aromatic sorbents may involve specific interactions between the planar regions of the antibiotic molecules and the phenyl rings of the aromatic sorbent. The interaction energies predicted from Monte Carlo simulations were observed to provide qualitative agreement with experimentally determined adsorption affinities. (c) 1995 John Wiley & Sons, Inc.     

Ernst Chain: a great man of science

This paper is a tribute to the scientific accomplishments of Ernst Chain and the influence he exerted over the fields of industrial microbiology and biotechnology. Chain is the father of the modern antibiotic era and all the benefits that these therapeutic agents have brought, i.e., longer life spans, greater levels of public health, widespread modern surgery, and control of debilitating infectious diseases, including tuberculosis, gonorrhea, syphilis, etc. Penicillin was the first antibiotic to become commercially available, and its use ushered in the age of antibiotics. The discovery of penicillin’s bactericidal action had been made by Alexander Fleming in London in 1928. After publishing his observations in 1929, no further progress was made until the work was picked up in 1939 by scientists at Oxford University. The group was headed by Howard Florey, and Chain was the group’s lead scientist. Chain was born and educated in Germany, and he fled in 1933 as a Jewish refugee from Nazism to England. Other important members of the Oxford research team were Norman Heatley and Edward Abraham. The team was able to produce and isolate penicillin under conditions of scarce resources and many technical challenges. Sufficient material was collected and tested on mice to successfully demonstrate penicillin’s bactericidal action on pathogens, while being nontoxic to mammals. Chain directed the microbiological methods for producing penicillin and the chemical engineering methods to extract the material. This technology was transferred to US government facilities in 1941 for commercial production of penicillin, becoming an important element in the Allied war effort. In 1945, the Nobel Prize for medicine was shared by Fleming, Florey, and Chain in recognition of their work in developing penicillin as a therapeutic agent. After World War II, Chain tried to persuade the British government to fund a new national antibiotic industry with both research and production facilities. As resources were scarce in postwar Britain, the British government declined the project. Chain then took a post in 1948 at Rome’s Instituto Superiore di Sanitá, establishing a new biochemistry department with a pilot plant. During that period, his department developed important new antibiotics (including the first semisynthetic antibiotics) as well as improved technological processes to produce a wide variety of important microbial metabolites that are still in wide use today. Chain was also responsible for helping several countries to start up a modern penicillin industry following World War II, including the Soviet Union and the People’s Republic of China. In 1964, Chain returned to England to establish a new biochemistry department and industrial scale fermentation pilot plant at Imperial College in London. Imperial College became the preeminent biochemical department in Europe. Chain was also a pioneer in changing the relationship between government, private universities, and private industry for collaboration and funding to support medical research. Ernst Chain has left a lasting impact as a great scientist and internationalist.     

Accelerating the discovery of antibacterial compounds using pathway-directed whole cell screening

Since the introduction of penicillin into the clinic in 1942, antibiotics have saved the lives of millions of people around the world. While penicillin and other traditional broad spectrum antibiotics were effective as monotherapies, the inexorable spread of antibiotic resistance has made alternative therapeutic approaches necessary. Compound combinations are increasingly seen as attractive options. Such combinations may include: lethal compounds; synthetically lethal compounds; or administering a lethal compound with a nonlethal compound that targets a virulence factor or a resistance factor. Regardless of the therapeutic strategy, high throughput screening is a key approach to discover potential leads. Unfortunately, the discovery of biologically active compounds that inhibit a desired pathway can be a very slow process, and an inordinate amount of time is often spent following up on compounds that do not have the desired biological activity. Here we describe a pathway-directed high throughput screening paradigm that combines the advantages of target-based and whole cell screens while minimizing the disadvantages. By exploiting this paradigm, it is possible to rapidly identify biologically active compounds that inhibit a pathway of interest. We describe some previous successful applications of this paradigm and report the discovery of a new class of d-alanylation inhibitors that may be useful as components of compound combinations to treat methicillin-resistant Staphylococcus aureus (MRSA).