Development Of Penicillin Resistance Research Articles

Methicillin-Resistant Staphylococcus aureus: A Pharmacotherapy Primer

Methicillin-Resistant Staphylococcus aureus: A Pharmacotherapy Primer

A High-Resolution View of Genome-Wide Pneumococcal Transformation

Transformation is an important mechanism of microbial evolution through which bacteria have been observed to rapidly adapt in response to clinical interventions; examples include facilitating vaccine evasion and the development of penicillin resistance in the major respiratory pathogen Streptococcus pneumoniae. To characterise the process in detail, the genomes of 124 S. pneumoniae isolates produced through in vitro transformation were sequenced and recombination events detected. Those recombinations importing the selected marker were independent of unselected events elsewhere in the genome, the positions of which were not significantly affected by local sequence similarity between donor and recipient or mismatch repair processes. However, both types of recombinations were sometimes mosaic, with multiple non-contiguous segments originating from the same molecule of donor DNA. The lengths of the unselected events were exponentially distributed with a mean of 2.3 kb, implying that recombinations are stochastically resolved with a fixed per base probability of 4.4×10−4 bp−1. This distribution of recombination sizes, coupled with an observed under representation of large insertions within transferred sequence, suggests transformation has the potential to reduce the size of bacterial genomes, and is unlikely to act as an efficient mechanism for the uptake of accessory genomic loci.

Towards an Understanding of Chromosomally Mediated Penicillin Resistance in Neisseria gonorrhoeae : Evidence for a Porin-Efflux Pump Collaboration

In this issue of the Journal of Bacteriology, Olesky et al. (13) report a novel observation regarding the mechanism by which Neisseria gonorrhoeae developed clinically significant levels of resistance to penicillin. Although yet to be fully defined, their results link changes in the structure of a gonococcal porin (PorB), which was presumed to modulate permeation of penicillin due to precedents set by studies with porins from Enterobacteriaceae (1, 11), with overexpression of a multidrug efflux pump and the development of penicillin resistance in gonococci. The implications of their work for further advancing our knowledge regarding the structure-function relationships of the gram-negative cell envelope, differences between such bacteria in this respect, and the connection of efflux pumps with other cell envelope proteins in the development of antibiotic resistance are substantial. Moreover, the findings justify continued research on basic problems of antibiotic resistance even when the antibiotic in question is no longer used clinically to treat the disease in question.

Application of a multiplex pbp2b and pbp2x PCR for prediction of penicillin resistance in Streptococcus pneumoniae

Sir, In Streptococcus pneumoniae, penicillin binding proteins (PBPs) 2b and 2x are the primary targets for penicillin. Hence, they are the first PBPs to be altered following mutations that lead to the development of penicillin resistance. Within the transpeptidase-encoding regions of the pbp2b and pbp2x genes, a few specific nucleotide changes have been shown to be common to penicillin-resistant pneumococci from many parts of the world. Polymerase chain reaction (PCR) primers have been developed to specifically amplify these mutant alleles. The primers are designed to be complementary to the mutant sequence, such that a PCR product is only produced if the mutation is present in the gene. 1,2 However, these previously developed PCR assays are limited to only detecting mutations in one of the pbp genes, and/or they require two or more separate PCR reactions to accommodate tests for all the resistance alleles. In this study, we report the evaluation of a one-tube, multiplex PCR reaction for detection of pbp2b and pbp2x mutations associated with penicillin resistance in S. pneumoniae. The primers used in the reaction are R1 to R4, P5 and P6, specific for pbp2b, and Pn-RX1 and Pn-RX2 for pbp2x. The sequences of these primers have been reported previously. 2,3 Possible PCR products have sizes (in bp) of 183 (primer pair Pn-RX1 and Pn-RX2), 214 (primer pair R4 and P6), 328 (primer pair R2 and P6), 331 (primer pair R1 and P6), 334 (primer pair R3 and P6) and 682 (primer pair P5 and P6—used as a PCR control). To test the multiplex PCR assay, a collection of 383 nasopharyngeal isolates of S. pneumoniae4 obtained from among 1978 children aged less than 6 years attending 79 day care centres and kindergartens in all areas of Hong Kong was tested. The penicillin MICs of the isolates were determined by the Etest method. The 40 µL optimal PCR reaction comprised 2.2 mM MgCl2, dNTP at 200 µM, 1 U of AmpliTaq Gold in 1× PCR buffer (Applied Biosystems, Foster City, CA, USA), primers (P5 and P6 at 1 µM; R1 to R4 at 0.1 µM; PnRx1 and PnRx2 at 0.2 µM) and 4 µL of DNA template (generated by rapid alkaline lysis of cells). PCR was carried out using the following conditions: an initial activation at 95°C for 8 min, then 10 cycles of

Analysis of penicillin-binding protein lb and 2a genes from Streptococcus pneumoniae.

Fifty clinical isolates (penicillin MICs, 0.03-8 microg/mL) of Streptococcus pneumoniae were randomly selected from hospitals throughout South Africa, together with seven strains isolated in Hungary (penicillin MICs, 16-32 microg/mL). Penicillin-binding protein (pbp) 1b and 2a genes were amplified by PCR, and the purified DNA was digested with HinfI, StyI, and MseI + DdeI restriction enzymes. The fragments were radioactively end-labeled and separated on polyacrylamide gels, and the DNA fingerprints were visualized following autoradiography. A collection of isolates was further selected for sequence analysis of pbp1b and 2a. DNA fingerprint analysis revealed a uniform profile amongst all isolates for both genes. All isolates revealed a maximum of only seven nucleotide substitutions in their pbp1b genes, resulting in a maximum of three amino acid substitutions in PBP 1B. In the case of the pbp2a gene, up to 13 nucleotide substitutions were observed randomly distributed amongst penicillin-susceptible and resistant isolates, revealing a maximum of five amino acid substitutions in PBP 2A. No amino acid substitutions were found to be common amongst all penicillin-resistant isolates. Transformation experiments with pbp1b and 2a genes isolated from two resistant strains (MICs, 4 and 16 microg/mL) failed to transform pneumococcal strains to increased levels of penicillin resistance. These results show that the pbp1b and 2a genes examined here do not display the typical mosaic gene patterns observed in the pbp2x, 2b, and 1a genes of penicillin-resistant pneumococci. In addition, the transformation studies suggest that PBPs 1B and 2A may not play a role in the development of penicillin resistance in some pneumococci.

Development of penicillin resistance among Staphylococcus aureus isolated from bovine mastitis in Denmark and other countries.

This review gathers the published information regarding penicillin resistance among Staphylococcus aureus isolated from bovine mastitis from 43 different countries worldwide. For selected countries, trends over time are shown. The occurrence of resistance in the different countries is discussed in relation to the potential value of penicillin for therapy.

Staphylococcosis of Turkeys. 6. Development of Penicillin Resistance in an Interfering Strain of Staphylococcus epidermidis

Staphylococcus epidermidis strain 115, used as an interfering agent to help reduce the incidence of staphylococcosis in turkeys, was converted into a penicillin- and chloramphenicol-resistant strain designated 115R. This was accomplished by introducing a plasmid carrying the beta-lactamase (penicillinase) and chloramphenicol-resistance genes into S. epidermidis 115 by electroporation. The resultant strain, 115R, was an efficient producer of beta-lactamase and had marked increased resistance to penicillin and chloramphenicol. A beta-lactamase DNA probe was used to confirm the presence of the beta-lactamase gene in strain 115R. S. epidermidis strain 115R retained the characteristics of tissue adherence, bacteriocin production, and non-virulence that were present in the original non-transformed strain 115, and in addition should theoretically remain colonized in poults following treatment with penicillin.

Penicillin-binding proteins of clostridia

The penicillin-binding protein (PBP) profiles of 33Clostridium perfringens and sixClostridium species isolated from clinically significant infections were analyzed. Three new PBPs—PBPs 2B, 4B, and 5B (84, 70, and 49 kDa respectively)—and a high-molecular-weight PBP 6 (45 kDa) were demonstrated in theC. perfringens isolates. In addition to PBPs 1 and 2, PBPs 2B and 4B were seen to show low binding affinities for penicillin, although further studies are required to determine their possible roles in the development of penicillin resistance. The PBP profiles of theC. perfringens isolates were complex. Variations in apparent molecular weights (M r s) of all PBPs, with the exception of PBP 5 and the presence or absence of PBPs 2, 3, and 4B, gave rise to nine different PBP patterns. The high-MrPBPs 5 and 6, which exhibited high-penicillin-binding affinities, were with only one exception consistent within theC. perfringens isolates. These PBPs 5 and 6 of theC. perfringens isolates and independent PBPs found in the otherClostridium species studied indicate that PBP analysis may assist in the differentiation ofClostridium spacies.

Nucleotide sequences of the pbpX genes encoding the penicillin-binding proteins 2x from Streptococcus pneumoniae R6 and a cefotaxime-resistant mutant, C506.

Development of penicillin resistance in Streptococcus pneumoniae is due to successive mutations in penicillin-binding proteins (PBPs) which reduce their affinity for beta-lactam antibiotics. PBP2x is one of the high-Mr PBPs which appears to be altered both in resistant clinical isolates, and in cefotaxime-resistant laboratory mutants. In this study, we have sequenced a 2564 base-pair chromosomal fragment from the penicillin-sensitive S. pneumoniae strain R6, which contains the PBP2x gene. Within this fragment, a 2250 base-pair open reading frame was found which coded for a protein having an Mr of 82.35kD, a value which is in good agreement with the Mr of 80-85 kD measured by SDS-gel electrophoresis of the PBP2x protein itself. The N-terminal region resembled an unprocessed signal peptide and was followed by a hydrophobic sequence that may be responsible for membrane attachment of PBP2x. The corresponding nucleotide sequence of the PBP2x gene from C504, a cefotaxime-resistant laboratory mutant obtained after five selection steps, contained three nucleotide substitutions, causing three amino acid alterations within the beta-lactam binding domain of the PBP2x protein. Alterations affecting similar regions of Escherichia coli PBP3 and Neisseria gonorrhoeae PBP2 from beta-lactam-resistant strains are known. The penicillin-binding domain of PBP2x shows highest homology with these two PBPs and S. pneumoniae PBP2b. In contrast, the N-terminal extension of PBP2x has the highest homology with E. coli PBP2 and methicillin-resistant Staphylococcus aureus PBP2'. No significant homology was detected with PBP1a or PBP1b of Escherichia coli, or with the low-Mr PBPs.

BACTERIAL versatility.

BACTERIAL versatility.

Studies on the Action of Penicillin: VII. Development of Penicillin Resistance by Meningococcus in Vivo

Numerous reports have described the development of penicillin resistance in vitro during the course of repeated subcultivation onto mediums containing increasing concentrations of the drug. Accounts of the development of penicillin resistance in vivo are less numerous, however. Schmidt and Sesler1 showed that pneumococcus developed a 4-fold increase in penicillin resistance during 7 passages through mice. Gezon and Collins2 found a definite increase in the quantity of penicillin required to sterilize embryonated eggs inoculated with Group B and Group C beta hemolytic streptococci during the course of 25 egg passages, although when tested in vitro these microorganisms were found to be no more resistant than they were originally. Gezon and Collins were unable, however, to demonstrate any significant increase in resistance in 2 strains of Group A streptococci during 25 passages in penicillin-treated eggs or during 15 passages in penicillin-treated mice.

BACTERIAL RESISTANCE TO ANTIBIOTICS

Article1 November 1948BACTERIAL RESISTANCE TO ANTIBIOTICSC. PHILLIP MILLER, M.D., F.A.C.P.C. PHILLIP MILLER, M.D., F.A.C.P.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-29-5-765 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptThe development of resistance to the antibiotic drugs is a problem of theoretical interest to the bacteriologist and of practical importance to the clinician.I should like to describe briefly some experimental studies on the development of bacterial resistance to penicillin and streptomycin and then discuss the clinical implications suggested by these laboratory observations.DEVELOPMENT OF PENICILLIN RESISTANCEResistance to penicillin can develop in some bacteria, but it usually develops slowly. Meningococcus, for example, has been found to acquire resistance to penicillin if it is repeatedly subcultured onto media containing increasing concentrations of the drug. The graph in figure 1...Bibliography1. MILLERBOHNHOFF CPM: Studies on action of penicillin. V. Virulence of penicillin resistant strains of meningococcus, Proc. Soc. Exper. Biol. and Med., 1945, lx, 356-357. MILLER, C. P., and BOHNHOFF, M.: Studies on the action of penicillin. VI. Further observations on the development of penicillin resistance by meningococcus in vitro, Jr. Infect. Dis., 1947, lxxxi, 147-156. CrossrefGoogle Scholar2. DEMEREC M: Production of staphylococcus strains resistant to various concentrations of penicillin, Proc. Nat. Acad. Sci., 1945, xxxi, 16-24. CrossrefGoogle Scholar3. KLEIN M: A mechanism for the development of resistance to streptomycin and penicillin, Jr. Bact., 1947, liii, 463-467. CrossrefGoogle Scholar4. MILLERBOHNHOFF CPM: Studies on the action of penicillin. VII. 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FLEMING A: Discussion on chemotherapy and wound infection, Proc. Roy. Soc. Med., 1941, xxxiv, 342-343. Google Scholar10. MILLERBOHNHOFF CPM: Streptomycin resistance of gonococci and meningococci, Jr. Am. Med. Assoc., 1946, cxxx, 485-488. CrossrefGoogle Scholar11. MILLERBOHNHOFF CPM: Development of streptomycin-resistant variants of meningococcus, Science, 1947, cv, 620-621. CrossrefGoogle Scholar12. MILLERBOHNHOFF CPM: Two streptomycin-resistant variants of meningococcus, Jr. Bact., 1947, liv, 467-481. CrossrefGoogle Scholar13. PAINEFINLAND TFM: Streptomycin sensitive, dependent and resistant bacteria, Science, 1948, cvii, 143-144. CrossrefGoogle Scholar14. KUSHNICKRANDLESGRAYBIRKELAND TCICTJM: Variants of Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis requiring streptomycin, Science, 1947, cvi, 587-588. CrossrefGoogle Scholar15. YEGIANBUDD DV: A variant of Mycobacterium ranae requiring streptomycin for growth, Jr. Bact., 1948, lv, 459-461. CrossrefGoogle Scholar16. RAKE G: Streptomycin as an essential nutrilite, Proc. Soc. Exper. Biol. and Med., 1948, lxvii, 249-253. CrossrefGoogle Scholar17. MILLERBOHNHOFF CPM: The effect of streptomycin therapy on the bacterial flora of the throat, Am. Jr. Med. (In press.) Google Scholar This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: Chicago, Illinois*Presented at a General Session of the twenty-ninth annual meeting of the American College of Physicians, San Francisco, April 21, 1948.From the Department of Medicine, University of Chicago. Nextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byPharmaceuticals and the Environment (PiE): Evolution and impact of the published literature revealed by bibliometric analysisEmergence of Antibiotic-Resistant BacteriaStreptomycinresistente Varianten bei MeningokokkenAerosol therapy in the practice of allergyThe PhytoflagellatesThe Clinical Importance of Coagulase-Positive, Penicillin-Resistant Staphylococcus aureusStreptomycin–Dependent BacteriaStreptomycin as a Prophylactic AgentTreatment of Common Forms of Meningitis 1 November 1948Volume 29, Issue 5Page: 765-774KeywordsAntibiotic resistanceAntibioticsAttentionBacteriaDrugsNeisseria meningitidisPenicillinResearch laboratoriesStreptomycin ePublished: 1 December 2008 Issue Published: 1 November 1948 Copyright & PermissionsCopyright, 1948, by The American College of PhysiciansPDF downloadLoading ...

Drug Sensitivity of Hemolytic Streptococci Isolated from Cases of Scarlet Fever Treated with Penicillin.

Summary(1) Studies of the penicillin sensitivity of group A hemolytic streptococci isolated from scarlet fever patients before, during, and following penicillin therapy indincate that, with the usual “short” courses of treatment, drug-resistant strains of the organism do not appear.(2) The likelihood of the development of penicillin resistance in cases of streptococcal infection treated with this agent appears to be very remote.(3) No penicillin-resistant strains of Strep. pyogenes (group A) were recovered in any instance before antibiotic therapy was started.

Bacteriologic studies of the sputum in patients with pneumococcal pneumonia treated with penicillin.

Abstract Sputum and throat cultures and stained smears of sputum were studied before, during, and after treatment with penicillin in twenty-six patients with pneumococcal pneumonia. Considerable differences were noted in the persistence of pneumococci in these patients. About one-sixth of the strains found before penicillin therapy was started persisted throughout the period of observation. About three-fourths of the remaining strains could no longer be found after the third day of treatment. Strains of pneumococci of types not identified in the pretreatment cultures were found for the first time during or after penicillin therapy in six patients. Only one of the strains, however, was found in more than a single specimen. All of the strains of pneumococci tested were sensitive to penicillin, and three strains isolated after therapy were found to be just as sensitive as the pretreatment strains of the same types isolated from the same patients. The persistence of pneumococci in the sputum did not appear to be definitely related to bacteremia, complications, chronic respiratory infections, the numbers of organisms present before treatment, the development of penicillin resistance, or the failure to develop antibodies, as judged by phagocytosis of pneumococci in stained smears. In one patient a staphylococcal pneumonia developed as a complication of the pneumococcal lobar pneumonia. The staphylococcus first appeared in the culture of the sputum obtained twelve hours after penicillin was started and then became predominant in subsequent cultures. It was quite resistant to penicillin, and improvement occurred only after intensive sulfonamide therapy. Following penicillin therapy, the flora of the sputum changed in most instances to one in which the predominant organisms were gram-negative bacilli having the morphology and colony characteristics of influenza bacilli.

Studies on the Action of Penicillin. IV. Development of Penicillin Resistance by Gonococcus.

SummaryPenicillin-fastness developed most rapidly in gonococci under conditions which permitted the greatest number of viable microorganisms to be transferred to a higher concentration of penicillin at each transfer. One strain of gonococcus acquired the ability to prow on media containing 21 units per ml. So appreciable increase in penicillin tolerance resulted from repeated exposure to bacteriostatic concentrations of penicillin.