Chloramphenicol and Thiamphenicol
M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson in Kucers’ The Use of Antibiotics, 2017
Emergence of chloramphenicol-resistant S. typhi during treatment was first detected in Britain (Colquhoun and Weetch, 1950). Although such strains remained relatively rare for the next 20 years (Winshell et al., 1969), an epidemic of typhoid fever involving over 10,000 cases in Mexico occurred from February 1972 until June 1973. The S. typhi strain concerned possessed resistance to chloramphenicol, tetracycline, streptomycin, and the sulfonamides (Vazquez et al., 1972; Olarte and Galindo, 1973), mediated by a single plasmid (Balows, 1977). During this epidemic, a few S. typhi strains were isolated that were also resistant to ampicillin. Ampicillin resistance was mediated by a separate plasmid (Balows, 1977). Fortunately, strains with this dual resistance did not spread widely, and the vast majority of chloramphenicol-resistant organisms remained susceptible to ampicillin (Overturf et al., 1973; Datta and Olarte, 1974). After the epidemic in Mexico abated in 1973, typhoid remained endemic in the area, although the previously resistant S. typhi strains were replaced by chloramphenicol-susceptible ones (Balows, 1977).
Enterococci: Resistance Update and Treatment Options
Robert C. Owens, Lautenbach Ebbing in Antimicrobial Resistance, 2007
Overproduction and/or mutation of the PBP 5 receptor leading to diminished affinity for beta-lactams has increased dramatically in E. faecium but remains uncommon (< 5%) among E. faecalis strains (13,14). This property is expressed constitutively and carried by resistance genes located on chromosomal elements. E. faecium strains with acquired high-level ampicillin resistance have ampicillin minimum inhibitory concentrations (MICs) > 128 mg/mL and are neither inhibited nor killed by ampicillin, penicillin or other beta-lactams. The ubiquity of high-level ampicillin resistance has been a major step toward the eventual evolution of multidrug resistance among E. faecium as the superimposition of other resistance traits have appeared in such strains.
The Regulatory Process and Gene Therapy 1
Eric Wickstrom in Clinical Trials of Genetic Therapy with Antisense DNA and DNA Vectors, 2020
For plasmid gene therapies, one issue has been raised by the common use of ampicillin resistance as a selection marker. As stated in the "Points to Consider in the Characterization of Cell Lines Used to Produce Biologicals (1993)," penicillin and other beta-lactam antibiotics should be avoided in production cultures, due to the possibility of residual antibiotic or adducts in the final product and antibiotic hypersensitivity in some people. For licensed products, current regulations (21 CFR 6l0.6l(m)) require product labeling to declare any antibiotics added during manufacturing, and use of penicillin may concern physicians. If a construct has already been made and contains the amp" gene, it may be possible to use it in some situations if ampicillin is not used in making the final product. If the antibiotic is used in production, contact CBER concerning the nature of the protocol and the proposed patient population.
Characterization of the phosphotransacetylase-acetate kinase pathway for ATP production in Porphyromonas gingivalis
Published in Journal of Oral Microbiology, 2019
Yasuo Yoshida, Mitsunari Sato, Takamasa Nonaka, Yoshiaki Hasegawa, Yuichiro Kezuka
To examine the physiological roles of pta and ack genes in P. gingivalis ATCC 33277, we attempted to construct chromosomal knockout mutants of each gene using a standard allelic replacement procedure that involves the insertion of an ampicillin resistance gene into the target gene (Supplemental Figure S5). However, attempts to obtain mutant P. gingivalis strains in which pta or ack was inactivated were unsuccessful (Table 4). Furthermore, when an erythromycin resistance cassette was used instead of an ampicillin resistance gene, no null mutants were obtainable (data not shown). By contrast, using the same procedure, it was possible to obtain null mutants of both PGN_1180 and the PGN_1177 genes, which are located upstream from pta and downstream from ack, respectively (Table 4).
Research progress of nanocarriers for gene therapy targeting abnormal glucose and lipid metabolism in tumors
Published in Drug Delivery, 2021
Xianhu Zeng, Zhipeng Li, Chunrong Zhu, Lisa Xu, Yong Sun, Shangcong Han
The recombinant adenovirus was constructed by cloning the 2,337 base-pair PCR product into linearized adenovirus plasmid GV314 using T4 DNA ligase and transfecting into competent Escherichia coli cells. Positive clones were screened by ampicillin resistance and then underwent ABI 3730 sequencing analysis. SIK1-overexpressing adenovirus (Ad-SIK1) was packaged in human embryonic kidney 293 T cells and purified with the Adenovirus X purification kit. The virus titer was determined by an end-point dilution method (Zhou et al. 2019). The results showed that SIK1 plays an important role in the regulation of liver glucose and lipid metabolism, and it inhibits liver gluconeogenesis and lipogenesis. SIK1 also plays a role in the regulation of metabolic diseases and is found in tumor diseases. In cervical squamous cell carcinoma cells, SIK1 inhibits the invasion and metastasis of cancer cells (Peng et al. 2020). In colorectal cancer, the upregulated targeting of SIK1 by miR-17 has been found to promote the process of colorectal cancer, and thus, this mechanism has also become a potential therapeutic target (Huang et al. 2019).
Severe, non specific symptoms in non-typhoidal Salmonella infections in adult patients with sickle cell disease: a retrospective multicentre study
Published in Infectious Diseases, 2018
Romain Guery, Anoosha Habibi, Jean-Benoît Arlet, François Lionnet, Victoire de Lastours, Jean-Winoc Decousser, Jean-Luc Mainardi, Keyvan Razazi, Laurence Baranes, Pablo Bartolucci, Bertrand Godeau, Fréderic Galacteros, Marc Michel, Matthieu Mahevas
NTS episodes were community-acquired in all cases. Isolated serotypes were: ser. Enteritidis (n = 8), ser. Typhimurium (n = 6), ser. Dublin (n = 2), ser. Wichita (n = 1). Definitive serovars were undetermined for six isolates. All cultures were monomicrobial. Blood cultures were positive in 65% of episodes. Salmonella spp. was also found in synovial fluid or bone biopsy (n = 6), abscess fluid (n = 5), stool culture (n = 1), adenitis (n = 1). Highest antibiotic resistance was observed with ampicillin (30%), followed by sulfamethoxazole-trimethoprim (9%) and nalidixic acid (9%). As expected, Penicillin V prophylaxis was associated with ampicillin resistance of Salmonella spp. isolates (4 isolates were ampicillin resistant among 5 cases under penicillin prophylaxis). No resistance was observed for third-generation cephalosporins or aminoglycosides. Supplementary Table I outlines the characteristics of antimicrobial therapy during NTS episodes. Third-generation cephalosporins were more commonly used as first-line agents, followed by fluoroquinolones or sulfamethoxazole-trimethoprim. High prevalence of osteo-articular localizations (n = 13) and secondary foci (n = 9) explained prolonged treatment duration (median 44 days [range 7–102]).
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