1
|
Gardner TJ, Lee JP, Bourne CM, Wijewarnasuriya D, Kinarivala N, Kurtz KG, Corless BC, Dacek MM, Chang AY, Mo G, Nguyen KM, Brentjens RJ, Tan DS, Scheinberg DA. Engineering CAR-T cells to activate small-molecule drugs in situ. Nat Chem Biol 2022; 18:216-225. [PMID: 34969970 PMCID: PMC9152922 DOI: 10.1038/s41589-021-00932-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 10/21/2021] [Indexed: 12/17/2022]
Abstract
Chimeric antigen receptor (CAR)-T cells represent a major breakthrough in cancer therapy, wherein a patient's own T cells are engineered to recognize a tumor antigen, resulting in activation of a local cytotoxic immune response. However, CAR-T cell therapies are currently limited to the treatment of B cell cancers and their effectiveness is hindered by resistance from antigen-negative tumor cells, immunosuppression in the tumor microenvironment, eventual exhaustion of T cell immunologic functions and frequent severe toxicities. To overcome these problems, we have developed a novel class of CAR-T cells engineered to express an enzyme that activates a systemically administered small-molecule prodrug in situ at a tumor site. We show that these synthetic enzyme-armed killer (SEAKER) cells exhibit enhanced anticancer activity with small-molecule prodrugs, both in vitro and in vivo in mouse tumor models. This modular platform enables combined targeting of cellular and small-molecule therapies to treat cancers and potentially a variety of other diseases.
Collapse
Affiliation(s)
| | - J. Peter Lee
- Chemical Biology Program, Sloan Kettering Institute,,Tri-Institutional PhD Program in Chemical Biology
| | - Christopher M. Bourne
- Molecular Pharmacology Program, Sloan Kettering Institute,,Immunology Program, Weill Cornell Graduate School of Medical Sciences, and
| | - Dinali Wijewarnasuriya
- Department of Medicine, Memorial Hospital,,BCMB Allied Program, Weill Cornell Graduate School of Medical Sciences
| | | | - Keifer G. Kurtz
- Molecular Pharmacology Program, Sloan Kettering Institute,,Pharmacology Program, Weill Cornell Graduate School of Medical Sciences
| | - Broderick C. Corless
- Chemical Biology Program, Sloan Kettering Institute,,Pharmacology Program, Weill Cornell Graduate School of Medical Sciences
| | - Megan M. Dacek
- Molecular Pharmacology Program, Sloan Kettering Institute,,Pharmacology Program, Weill Cornell Graduate School of Medical Sciences
| | - Aaron Y. Chang
- BCMB Allied Program, Weill Cornell Graduate School of Medical Sciences
| | - George Mo
- Molecular Pharmacology Program, Sloan Kettering Institute
| | | | - Renier J. Brentjens
- Department of Medicine, Memorial Hospital,,Pharmacology Program, Weill Cornell Graduate School of Medical Sciences
| | - Derek S. Tan
- Chemical Biology Program, Sloan Kettering Institute,,Tri-Institutional PhD Program in Chemical Biology,,Pharmacology Program, Weill Cornell Graduate School of Medical Sciences,,Tri-Institutional Research Program, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA, Corresponding authors. ,
| | - David A. Scheinberg
- Molecular Pharmacology Program, Sloan Kettering Institute,,Tri-Institutional PhD Program in Chemical Biology,,Department of Medicine, Memorial Hospital,,Pharmacology Program, Weill Cornell Graduate School of Medical Sciences,, Corresponding authors. ,
| |
Collapse
|
2
|
El‐Zamkan MA, Mohamed HM. Molecular detection ofEnterobacterspp. and other related species in powdered milk infant formula and milk powder. J Food Saf 2018. [DOI: 10.1111/jfs.12538] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Mona A. El‐Zamkan
- Department of Food Hygiene and ControlFaculty of Veterinary Medicine, South Valley UniversityQenaEgypt
| | - Hams M.A. Mohamed
- Department of MicrobiologyFaculty of Veterinary Medicine, South Valley UniversityQenaEgypt
| |
Collapse
|
3
|
Rubtsova MY, Ulyashova MM, Bachmann TT, Schmid RD, Egorov AM. Multiparametric determination of genes and their point mutations for identification of beta-lactamases. BIOCHEMISTRY (MOSCOW) 2011; 75:1628-49. [PMID: 21417998 DOI: 10.1134/s0006297910130080] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
More than half of all currently used antibiotics belong to the beta-lactam group, but their clinical effectiveness is severely limited by antibiotic resistance of microorganisms that are the causative agents of infectious diseases. Several mechanisms for the resistance of Enterobacteriaceae have been established, but the main one is the enzymatic hydrolysis of the antibiotic by specific enzymes called beta-lactamases. Beta-lactamases represent a large group of genetically and functionally different enzymes of which extended-spectrum beta-lactamases (ESBLs) pose the greatest threat. Due to the plasmid localization of the encoded genes, the distribution of these enzymes among the pathogens increases every year. Among ESBLs the most widespread and clinically relevant are class A ESBLs of TEM, SHV, and CTX-M types. TEM and SHV type ESBLs are derived from penicillinases TEM-1, TEM-2, and SHV-1 and are characterized by several single amino acid substitutions. The extended spectrum of substrate specificity for CTX-M beta-lactamases is also associated with the emergence of single mutations in the coding genes. The present review describes various molecular-biological methods used to identify determinants of antibiotic resistance. Particular attention is given to the method of hybridization analysis on microarrays, which allows simultaneous multiparametric determination of many genes and point mutations in them. A separate chapter deals with the use of hybridization analysis on microarrays for genotyping of the major clinically significant ESBLs. Specificity of mutation detection by means of hybridization analysis with different detection techniques is compared.
Collapse
Affiliation(s)
- M Yu Rubtsova
- Chemical Faculty, Lomonosov Moscow State University, Russia.
| | | | | | | | | |
Collapse
|
4
|
Sullivan HR, McMahon RE. Metabolism of oral cephalothin and related cephalosporins in the rat. Biochem J 2010; 102:976-82. [PMID: 16742517 PMCID: PMC1270351 DOI: 10.1042/bj1020976] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The fate of orally administered [(14)C]cephalothin has been studied in the rat. This antibiotic undergoes degradation in the gut followed by the subsequent absorption of a portion of the degradation products. About 50% of the administered radioactivity appears in the urine as a mixture of thienylacetylglycine, thienylacetamidoethanol and an unidentified polar metabolite. Evidence is presented indicating that thienylacetamidoethanol arises by the enzymic reduction of a metabolic intermediate, thienylacetamidoacetaldehyde. The metabolic fate of cephalothin is very similar to that of cephaloram reported earlier. The fate of [(14)C]cephaloridine and 7-phenoxy[1-(14)C]acetamidocephalosporin was also investigated. In addition to the expected metabolites, about 5% of the cephaloridine dose is absorbed unchanged. With 7-phenoxy[1-(14)C]acetamidocephalosporin, 15% of the dose is recovered in urine as deacetyl-7-phenoxy[1-(14)C]acetamidocephalosporin.
Collapse
Affiliation(s)
- H R Sullivan
- Lilly Research Laboratories, Indianapolis, Ind. 46206, U.S.A
| | | |
Collapse
|
5
|
Cimolai N. Methicillin-resistant Staphylococcus aureus in Canada: a historical perspective and lessons learned. Can J Microbiol 2010; 56:89-120. [PMID: 20237572 DOI: 10.1139/w09-109] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The history of methicillin-resistant Staphylococcus aureus (MRSA) in Canada has many similarities to MRSA evolution worldwide, but especially to that in the United States and United Kingdom. Reports of MRSA occurred as early as 1964, and community isolates were cited in the 1970s. Nosocomial outbreaks were becoming common by 1978 and flourished gradually thereafter. Endemic institutional MRSA became predominant in the 1990s, threatening large teaching hospitals in particular. In the last decade, both hospital-acquired and community-acquired MRSA have created major medical problems in Canada. More recently, an epidemic of Canadian community-acquired MRSA-10, has led to heightened public health concerns. Canadian contributions to MRSA science are numerous, with organized surveillance continuing to mature across the nation. A typing system for epidemic clones is now available and is being judiciously applied. Estimated costs for MRSA surveillance, treatment, and control are extraordinary, paralleling the dramatic rise in the number of MRSA isolations. Whereas surveillance continues to form an essential aspect of MRSA management, control, eradication, and overall diminution, MRSA reservoirs deserve much greater attention. Such efforts, however, must be as widely publicized in the community and in patient homes as they are in medical institutions responsible for both acute and long-term care.
Collapse
Affiliation(s)
- Nevio Cimolai
- Department of Pathology and Laboratory Medicine, Children's and Women's Health Centre of British Columbia, Vancouver, Canada
| |
Collapse
|
6
|
Citri N, Pollock MR. The biochemistry and function of beta-lactamase (penicillinase). ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 28:237-323. [PMID: 5334062 DOI: 10.1002/9780470122730.ch4] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
7
|
|
8
|
Tondi D, Morandi F, Bonnet R, Costi MP, Shoichet BK. Structure-based optimization of a non-beta-lactam lead results in inhibitors that do not up-regulate beta-lactamase expression in cell culture. J Am Chem Soc 2005; 127:4632-9. [PMID: 15796528 PMCID: PMC1360654 DOI: 10.1021/ja042984o] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bacterial expression of beta-lactamases is the most widespread resistance mechanism to beta-lactam antibiotics, such as penicillins and cephalosporins. There is a pressing need for novel, non-beta-lactam inhibitors of these enzymes. One previously discovered novel inhibitor of the beta-lactamase AmpC, compound 1, has several favorable properties: it is chemically dissimilar to beta-lactams and is a noncovalent, competitive inhibitor of the enzyme. However, at 26 microM its activity is modest. Using the X-ray structure of the AmpC/1 complex as a template, 14 analogues were designed and synthesized. The most active of these, compound 10, had a K(i) of 1 microM, 26-fold better than the lead. To understand the origins of this improved activity, the structures of AmpC in complex with compound 10 and an analogue, compound 11, were determined by X-ray crystallography to 1.97 and 1.96 A, respectively. Compound 10 was active in cell culture, reversing resistance to the third generation cephalosporin ceftazidime in bacterial pathogens expressing AmpC. In contrast to beta-lactam-based inhibitors clavulanate and cefoxitin, compound 10 did not up-regulate beta-lactamase expression in cell culture but simply inhibited the enzyme expressed by the resistant bacteria. Its escape from this resistance mechanism derives from its dissimilarity to beta-lactam antibiotics.
Collapse
Affiliation(s)
- Donatella Tondi
- Department of Pharmaceutical Chemistry, University of California-San Francisco, 600 16th Street, San Francisco, CA 94143-2240, USA
| | | | | | | | | |
Collapse
|
9
|
|
10
|
Vilar M, Galleni M, Solmajer T, Turk B, Frère JM, Matagne A. Kinetic study of two novel enantiomeric tricyclic beta-lactams which efficiently inactivate class C beta-lactamases. Antimicrob Agents Chemother 2001; 45:2215-23. [PMID: 11451677 PMCID: PMC90634 DOI: 10.1128/aac.45.8.2215-2223.2001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A detailed kinetic study of the interaction between two ethylidene derivatives of tricyclic carbapenems, Lek 156 and Lek 157, and representative beta-lactamases and D-alanyl-D-alanine peptidases (DD-peptidases) is presented. Both compounds are very efficient inactivators of the Enterobacter cloacae 908R beta-lactamase, which is usually resistant to inhibition. Preliminary experiments indicate that various extended-spectrum class C beta-lactamases (ACT-1, CMY-1, and MIR-1) are also inactivated. With the E. cloacae 908R enzyme, complete inactivation occurs with a second-order rate constant, k(2)/K', of 2 x 10(4) to 4 x 10(4) M(-1) s(-1), and reactivation is very slow, with a half-life of >1 h. Accordingly, Lek 157 significantly decreases the MIC of ampicillin for E. cloacae P99, a constitutive class C beta-lactamase overproducer. With the other serine beta-lactamases tested, the covalent adducts exhibit a wide range of stabilities, with half-lives ranging from long (>4 h with the TEM-1 class A enzyme), to medium (10 to 20 min with the OXA-10 class D enzyme), to short (0.2 to 0.4 s with the NmcA class A beta-lactamase). By contrast, both carbapenems behave as good substrates of the Bacillus cereus metallo-beta-lactamase (class B). The Streptomyces sp. strain R61 and K15 extracellular DD-peptidases exhibit low levels of sensitivity to both compounds.
Collapse
Affiliation(s)
- M Vilar
- Laboratoire d'Enzymologie, Centre for Protein Engineering, University of Liège, Institut de Chimie, Belgium
| | | | | | | | | | | |
Collapse
|
11
|
Heritage J, M'Zali FH, Gascoyne-Binzi D, Hawkey PM. Evolution and spread of SHV extended-spectrum beta-lactamases in gram-negative bacteria. J Antimicrob Chemother 1999; 44:309-18. [PMID: 10511397 DOI: 10.1093/jac/44.3.309] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Resistance to beta-lactam antibiotics has been a problem for as long as these drugs have been used in clinical practice. In clinically significant bacteria the most important mechanism of resistance is the production of one or more beta-lactamases, enzymes that hydrolyse the beta-lactam bond characteristic of this family of antibiotics. Prominent among the beta-lactamases produced by the Enterobacteriaceae is the SHV family. The first reported SHV beta-lactamase had a narrow spectrum of activity. By the accumulation of point mutations at sites that affect the active site of the enzyme, a family of derivatives of SHV-1 has evolved. Derivatives of SHV-1 either have an extended spectrum of activity, capable of inactivating third-generation cephalosporins, or are resistant to beta-lactamase inhibitors. This review describes the evolution and spread of the SHV family of beta-lactamases, introducing the structure-function analysis made possible by DNA sequence analysis. It also reviews the methods used to characterize members of this family of beta-lactamases, indicating some of the difficulties involved.
Collapse
Affiliation(s)
- J Heritage
- Division of Microbiology, School of Biochemistry and Molecular Biology, and Antimicrobial Research Centre, University of Leeds, UK.
| | | | | | | |
Collapse
|
12
|
POLLOCK MR. PURIFICATION AND PROPERTIES OF PENICILLINASES FROM TWO STRAINS OF BACILLUS LICHENIFORMIS: A CHEMICAL, PHYSICOCHEMICAL AND PHYSIOLOGICAL COMPARISON. Biochem J 1996; 94:666-75. [PMID: 14340057 PMCID: PMC1206601 DOI: 10.1042/bj0940666] [Citation(s) in RCA: 159] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
1. The penicillinases formed by penicillinase-constitutive mutant strains from two closely related varieties (749 and 6346) of Bacillus licheniformis have been isolated, characterized and compared. They are chemically, physicochemically and immunologically very similar, but differ enzymologically in absolute and relative activity on, and affinity for, different penicillins and cephalosporins. 2. The molecular weights of both types are approx. 23000. Neither enzyme contains any cyst(e)ine. However, in most other respects they show little resemblance to any of the other penicillinases so far isolated. 3. Their properties, whether isolated from cells (to which approx. 50% of the activity is normally bound) or from the culture supernatant, appear to be similar. However, the molecular weight of a preparation of enzyme from strain 749/C obtained from the culture supernatant was found to be significantly (over 20%) higher than that obtained from cells alone. 4. With benzylpenicillin, the enzyme from strain 749 has V(max.) approx. 6 times higher than that of the enzyme from strain 6346, but this difference is ;compensated' by its affinity being 6 times lower. Thus, at the very low biologically effective concentrations of penicillin met with under natural conditions, where neither type of enzyme is more than a fraction saturated with its substrate, the antibiotic is hydrolysed at the same rate by both. As expected, the penicillin-sensitivities of single cells from the two strains were found to be identical. 5. It is suggested that the concept of ;physiological efficiency' (defined as V(max.) divided by K(m)), applied to enzymes acting naturally under conditions of poor saturation with their substrates, may be useful for expressing their biological function in vivo.
Collapse
|
13
|
BARBER M, WATERWORTH PM. PENICILLINASE-RESISTANT PENICILLINS AND CEPHALOSPORINS. BRITISH MEDICAL JOURNAL 1996; 2:344-9. [PMID: 14160224 PMCID: PMC1816326 DOI: 10.1136/bmj.2.5405.344] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
14
|
DARRELL JH, HURDLE AD. IDENTIFICATION AND CLINICAL SIGNIFICANCE OF KLEBSIELLA SPECIES IN CHEST INFECTIONS. J Clin Pathol 1996; 17:617-21. [PMID: 14227430 PMCID: PMC480844 DOI: 10.1136/jcp.17.6.617] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Using a short series of biochemical tests already in use in many routine laboratories, it is possible to identify strains of the genus Klebsiella and to differentiate K. aerogenes from other types. Marked production of slime is not peculiar to the group and colonial appearance alone is not a satisfactory basis for identification. K. aerogenes is the type most commonly isolated from all clinical specimens. It is suggested that the name may be retained in clinical bacteriology and used when applicable, particularly when reporting urinary strains. K. aerogenes is of doubtful pathogenicity when isolated from sputum; frequently its appearance follows antibiotic treatment for other organisms. It should be clearly distinguished from other Klebsiella types occurring as primary pathogens in sputum. Friedlander's bacillus is considered a suitable collective term for the latter, namely K. edwardsii-edwardsii, K. pneumoniae, and K. edwardsii-atlantae. The clinical significance of K. rhinoscleromatis and K. ozaenae could not be assessed as so few isolations were made. On the rare occasions when they occur they would, with the tests recommended, be included as Friedlander's bacillus, the distinction not being readily made in the clinical laboratory.
Collapse
|
15
|
Abstract
A study has been made of the antibiotic sensitivity pattern of 96 strains of Proteus isolated from clinical material and a further 29 strains kindly supplied by Dr. Patricia Carpenter. The results have been analysed in relation to the different species. The effect of electrolytes on the penicillin sensitivity of Proteus species has also been examined.
Collapse
|
16
|
Bush K, Jacoby GA, Medeiros AA. A functional classification scheme for beta-lactamases and its correlation with molecular structure. Antimicrob Agents Chemother 1995; 39:1211-33. [PMID: 7574506 PMCID: PMC162717 DOI: 10.1128/aac.39.6.1211] [Citation(s) in RCA: 1550] [Impact Index Per Article: 53.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- K Bush
- American Cyanamid Company, Lederle Laboratories, Pearl River, New York 10965, USA
| | | | | |
Collapse
|
17
|
Alexander RP, Beeley NR, O'Driscoll M, O'Neill FP, Millican T, Pratt AJ, Willenbrock FW. Cephalosporin Nitrogen Mustard Carbamate prodrugs for “ADEPT”. Tetrahedron Lett 1991. [DOI: 10.1016/s0040-4039(00)79741-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
18
|
Graham MN, Mantle TJ. Purification of a class C A-type beta-lactamase from a derepressed strain of Enterobacter cloacae. Comparison of the wild-type and mutant enzyme with those from strains P99, 208 and GN7471. Biochem J 1989; 260:705-10. [PMID: 2475102 PMCID: PMC1138734 DOI: 10.1042/bj2600705] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Enterobacter cloacae strain 5822 expresses low levels of a class C beta-lactamase which can be induced 100-fold by imipenem. Mutants that constitutively express high levels of beta-lactamase can be selected on aztreonam or cefotaxime. The beta-lactamase from one such mutant (5822M2) has been purified to homogeneity and compared on the basis of subunit Mr, pI, substrate specificity, inhibitor sensitivity and immunological cross-reactivity with the enzyme from strains P99, GN7471 and 208, which have been studied previously. The enzyme from strain 5822M2 is clearly related to these other forms and is of the A-type according to the criteria of Seeberg, Tolxdorff-Neutzling & Wiedemann [Antimicrob. Agents Chemother. (1983) 23, 918-925]. The enzyme from the wild-type strain (5822) is shown to be identical to that found in the depressed strain (5822M2), indicating that the mutation is in a regulatory gene. A detailed analysis of the kinetics of the enzyme from strain 5822M2 shows that all of the beta-lactams studied are substrates and that a mechanism involving the formation of an acyl-enzyme is probably applicable in every case. The substrates however can clearly be grouped into two classes, i.e. 'good' substrates with kcat. values of 80-1200 s-1 and 'poor' substrates/good inhibitors with kcat. values of 0.009-0.00007 s-1. The permeability barrier to aztreonam is 4-fold less in the derepressed strain when compared with the wild-type strain. This is associated with significant changes in the expression of outer membrane porins. The observed resistance in the derepressed mutant appears to be linked to the elevated levels of beta-lactamase (3000-fold) rather than to the modest changes in the permeability barrier.
Collapse
Affiliation(s)
- M N Graham
- Department of Biochemistry, Trinity College, Dublin 2, Ireland
| | | |
Collapse
|
19
|
Lindberg F, Normark S. Common mechanism of ampC beta-lactamase induction in enterobacteria: regulation of the cloned Enterobacter cloacae P99 beta-lactamase gene. J Bacteriol 1987; 169:758-63. [PMID: 3027046 PMCID: PMC211844 DOI: 10.1128/jb.169.2.758-763.1987] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Expression of the chromosomal beta-lactamase from the ampC gene in inducible in both Enterobacter cloacae and Citrobacter freundii. Cloning of ampC as well as its regulatory gene, ampR, from E. cloacae P99 revealed a gene organization indentical to that of C. freundii in the corresponding region. Although almost no similarities could be found between the restriction maps of ampC and ampR in the two species, the genes cross-hybridize. Also, both ampR gene products have a size of about 31,000. The regulatory features of E. cloacae beta-lactamase induction are very similar to those in C. freundii, i.e., beta-lactamase synthesis is repressed by AmpR in the absence, and stimulated in the presence, of inducer. The AmpR function can be transcomplemented between the two species, but there are quantitative regulatory aberrations in such hybrids, in contrast to the total complementation obtained within each system. These results suggest that the mechanism of beta-lactamase induction is the same in E. cloacae, C. freundii, and other gram-negative bacteria with inducible chromosomal beta-lactamase expression.
Collapse
|
20
|
Jouvenot M, Deschaseaux ML, Royez M, Mougin C, Cooksey RC, Michel-Briand Y, Adessi GL. Molecular hybridization versus isoelectric focusing to determine TEM-type beta-lactamases in gram-negative bacteria. Antimicrob Agents Chemother 1987; 31:300-5. [PMID: 3551834 PMCID: PMC174710 DOI: 10.1128/aac.31.2.300] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Isoelectric focusing and molecular hybridization with a TEM DNA probe were used to screen for TEM beta-lactamase in 328 bacterial isolates representing 11 gram-negative genera. The TEM enzyme was detected in 50% of isolates, and nine additional types of beta-lactamase could be identified in 36.9% of isolates. The TEM gene was detected in 53.6% of isolates. The results obtained by both methods were concordant in 92.7% of the entire sample. In situ colony hybridization with a specific probe therefore appears to be a convenient method to screen rapidly for the presence of homologous genetic sequences among a large number of isolates. Positive hybridization was observed for 16 isolates in which no TEM beta-lactamase was detected by isoelectric focusing. The significance of this hybridization remains to be determined.
Collapse
|
21
|
Tar A, Gál S, Toth-Martinez BL, Hernádi FJ, Kiss L. Use of chromatofocusing for separation of beta-lactamases. VII. Analytical and medium scale preparative chromatofocusing of the constitutive chromosomal cephalosporinase P99 from Enterobacter cloacae. J Chromatogr A 1986; 368:427-32. [PMID: 3491087 DOI: 10.1016/s0021-9673(00)91089-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
22
|
Gál S, Frommer-Filep M, Toth-Martinez BL, Hernádi FJ, Kiss L. Use of chromatofocusing for separation of beta-lactamases. V. Inducible chromosomally mediated beta-lactamase of the Enterobacter cloacae 53 strain. J Chromatogr A 1985; 333:239-43. [PMID: 3877734 DOI: 10.1016/s0021-9673(01)87349-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
23
|
Abstract
beta-Lactamases have proved to be extremely important in influencing therapy with penicillins and cephalosporins against gram-positive and gram-negative aerobic and anaerobic species. Both plasmid mediated beta-lactamases which are primarily of a constitutive penicillinase type and the inducible chromosomal enzymes which are primarily cephalosporinases are important. The use of penicillins to treat Haemophilus, Neisseria gonorrhoeae, Escherichia coli, Klebsiella, Salmonella, Shigella and Pseudomonas infections must be based upon the relative incidence of beta-lactamase producing strains. In the same manner cephalosporins can be used to treat infections due to Enterobacter, Serratia and Bacteroides only if the compounds are beta-lactamase stable and not good inducers of beta-lactamase activity. Although altered permeability is important in the resistance of some Pseudomonas and Enterobacter to beta-lactams, the resistance really is due to a combination of reduced entry of molecules and strategically placed beta-lactamases. It is only in some Streptococcus pneumoniae, methicillin-resistant Staphylococcus aureus and Streptococcus faecalis strains that altered penicillin-binding proteins make a significant contribution to the resistance to beta-lactams. beta-lactamases will continue to be the most important factor in clinically significant resistance of bacteria to both penicillins and cephalosporins.
Collapse
|
24
|
|
25
|
Lampe MF, Allan BJ, Minshew BH, Sherris JC. Mutational enzymatic resistance of Enterobacter species to beta-lactam antibiotics. Antimicrob Agents Chemother 1982; 21:655-60. [PMID: 6979311 PMCID: PMC181960 DOI: 10.1128/aac.21.4.655] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Mutants with enhanced beta-lactam resistance were selected from strains of Enterobacter cloacae and E. aerogenes by using three antibiotics. High-level beta-lactamase-producing mutants had similar degrees of increased resistance, enzyme substrate profiles, and isoelectric (pI) values irrespective of the selective agent. Reverse mutants from a resistant E. cloacae mutant regained the susceptibility pattern originally exhibited by the wild type, or were of enhanced susceptibility, and no longer expressed increased beta-lactamase production. beta-Lactamases of the mutants were similar in pI values to the wild-type enzyme. The increased resistance of the mutants therefore appeared to be accounted for by increased beta-lactamase production.
Collapse
|
26
|
Hook DJ, Chang LT, Elander RP, Morin RB. Stimulation of the conversion of penicillin N to cephalosporin by ascorbic acid, alpha-ketoglutarate, and ferrous ions in cell-free extracts of strains of Cephalosporium acremonium. Biochem Biophys Res Commun 1979; 87:258-65. [PMID: 572221 DOI: 10.1016/0006-291x(79)91674-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
27
|
Letarte R, Devaud-Felix M, Pechere JC, Allard-Leprohon D. Enzymatic and immunological characterization of a new cephalosporinase from Enterobacter aerogenes. Antimicrob Agents Chemother 1977; 12:201-5. [PMID: 900918 PMCID: PMC429885 DOI: 10.1128/aac.12.2.201] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A hospital strain of Enterobacter aerogenes (MULB 250) isolated from a urinary tract infection was found to be cephalosporin and ampicillin resistant and carbenicillin susceptible. The beta-lactamase produced by this strain was extracted and purified by means of affinity chromatography, using a cephalosporin C-bound Sepharose 4B column. The purified enzyme was tested for hydrolysis of penicillin and various cephalosporins. The K(m) value is 11.8 muM for benzyl penicillin and 130 muM for cephalosporin C. The isoelectric point of the enzyme is 9.3, and its molecular weight is 29,500 +/- 1,000. Rabbit antiserum obtained against this MULB 250 beta-lactamase showed no cross-reaction with other penicillinases or cephalosporinases in neutralization tests. Comparisons of results obtained with other beta-lactamases, particularly from Enterobacter cloacae P99, indicate that the Enterobacter MULB 250 enzyme presents a typical cephalosporinase profile. As far as we know, this type of enzyme is relatively rare.
Collapse
|
28
|
Findell CM, Sherris JC. Susceptibility of Enterobacter to cefamandole: evidence for a high mutation rate to resistance. Antimicrob Agents Chemother 1976; 9:970-4. [PMID: 938026 PMCID: PMC429659 DOI: 10.1128/aac.9.6.970] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Cefamandole minimum inhibitory concentrations (MICs) of 10 strains of Enterobacter were determined by the ICS agar dilution and broth dilution procedures. Agar dilution MICs ranged from 1 to 8 mug/ml, with an inoculum of 10(4) organisms/spot. Broth dilution MICs were consistently higher, with an inoculum of approximately 7 x 10(5) organisms/ml. Seven strains showed MICs of >/=64 mug/ml. There was a marked inoculum effect in broth, and skipped tubes were often observed. Variants resistant to 32 mug/ml or more were isolated by direct selection and were shown to occur at a frequency of approximately 10(-6) to 10(-7). A mutant showing a 16-fold increase in agar dilution MIC was also isolated by indirect selection. These variants and others isolated from broth in the presence of cefamandole were tested for ability to inactivate the antibiotic, using both a biological and a chemical procedure. Two distinct classes of variants were seen. Twelve of 28 were shown by both methods to inactivate the antibiotic, whereas the others, including the indirectly selected mutant, did not. The wild types were also negative by both tests. The higher cefamandole MICs of Enterobacter in broth, thus, appeared to reflect a high frequency of resistant variants that were not detected with the inoculum and end point criteria usually used in agar dilution methods. The ability of some variants to inactivate cefamandole may have resulted from a mutation that extended the activity of Enterobacter cephalosporinase to include this antibiotic.
Collapse
|
29
|
Abstract
A collection of 98 strains of enteric Gramnegative bacteria isolated in routine investigations in a hospital laboratory all showed beta-lactamase activity, and 39 of them (40%) produced sufficient enzyme to allow determination of their relative activities against benzylpenicillin, ampicillin and cephaloridine (substrate profiles). The commonest type of beta-lactamase, detected in 33 of the 39 strains, was an "all-purpose" enzyme that showed similar activity against the penicillins and the cephalosporins. All 39 were resistant to multiple antibiotics. They were examined for their ability to transfer the beta-lactamase gene during R-factor transfer, and transferability of the beta-lactamase gene was demonstrated in 13 strains out of 32.
Collapse
|
30
|
Owens DR, Luscombe DK, Russell AD, Nicholls PJ. The cephalosporin group of antibiotics. ADVANCES IN PHARMACOLOGY AND CHEMOTHERAPY 1975; 13:83-172. [PMID: 1106162 DOI: 10.1016/s1054-3589(08)60231-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
|
31
|
|
32
|
Sykes RB. Resistance of Pseudomonas aeruginosa to antimicrobial drugs. PROGRESS IN MEDICINAL CHEMISTRY 1975; 12:333-93. [PMID: 181789 DOI: 10.1016/s0079-6468(08)70180-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
33
|
Holmes B, King A, Phillips I, Lapage SP. Sensitivity of Citrobacter freundii and Citrobacter koseri to cephalosporins and penicillins. J Clin Pathol 1974; 27:729-33. [PMID: 4496972 PMCID: PMC475454 DOI: 10.1136/jcp.27.9.729] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
An examination of 99 field and reference strains of Citrobacter freundii showed 79% of them to be resistant to cephaloridine and sensitive to carbenicillin, while 96% of 45 field and reference strains of Citrobacter koseri examined were sensitive to cephaloridine and resistant to carbenicillin. Susceptibility tests with these two antibiotics are therefore useful in separating the two species of Citrobacter.
Collapse
|
34
|
Onishi HR, Daoust DR, Zimmerman SB, Hendlin D, Stapley EO. Cefoxitin, a semisynthetic cephamycin antibiotic: resistance to beta-lactamase inactivation. Antimicrob Agents Chemother 1974; 5:38-48. [PMID: 4599124 PMCID: PMC428916 DOI: 10.1128/aac.5.1.38] [Citation(s) in RCA: 114] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Cefoxitin is a new, cephalosporin-like antibiotic which is highly resistant to hydrolysis by beta-lactamase. Ninety-one cultures were selected either for their general resistance to cephalosporin antibiotics or for their ability to produce beta-lactamase. Some of these cultures were resistant to cefoxitin. The capacity of each of the 91 strains to hydrolyze cefoxitin with beta-lactamase was determined. Only seven of the cultures degraded the antibiotic as determined by a general assay for beta-lactamase. Several others were able to hydrolyze cefoxitin after enzyme was induced by low concentrations of the antibiotic. The role of the constitutive and inducible enzyme in bacterial resistance to the antibiotic was investigated. Enzymatic destruction of cefoxitin was found to be an important factor contributing to bacterial resistance. However, the complete and rapid degradation of cefoxitin is not essential to resistance since one strain, Enterobacter cloacae 1316, hydrolyzed the antibiotic very slowly but was able to grow unaffected in the presence of cefoxitin. The presence of the enzyme is not necessarily sufficient to confer resistance since another culture, Klebsiella D535, readily hydrolyzed the antibiotic but was susceptible to it.
Collapse
|
35
|
Sawai T, Yamagishi S, Mitsuhashi S. Penicillinases of Klebsiella pneumoniae and their phylogenetic relationship to penicillinases mediated by R factors. J Bacteriol 1973; 115:1045-54. [PMID: 4199503 PMCID: PMC246352 DOI: 10.1128/jb.115.3.1045-1054.1973] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
On the assumption that the penicillinase determinants on a group of R factors conferring ampicillin resistance have a phylogenetically close relationship to the penicillinase gene of the Klebsiella group, the penicillinases from four strains of K. pneumoniae, GN69, GN1103R(-), GN422, and GN118, were purified 230- to 1,000-fold and compared with the known two R-factor-mediated penicillinases. By gel filtration on Sephadex G-75, the molecular weights were estimated to be 17,400, 18,100, 20,000 and 18,300, respectively, which are slightly lower than those of the R-factor penicillinases. The isoelectric points of the Klebsiella penicillinases were not in agreement with those of the R-factor penicillinases. All the enzymes showed a pH optimum between 6.3 to 7.2 and a temperature optimum of 45 C, and those properties, together with behavior towards inhibitors, were about the same as those in the R-factor penicillinases. The substrate specificity and the Michaelis constants of the Klebsiella penicillinases for penicillins and cephaloridine were broadly similar to those of the R-factor penicillinases, however, some variations were found even among the four penicillinases of K. pneumoniae. The reactivities of the four penicillinases of K. pneumoniae with the antiserum against one R-factor penicillinase were tested, and three of the four Klebsiella penicillinases were found to be indistinguishable immunologically from both R-factor penicillinases. The remaining Klebsiella penicillinase, from GN1103R(-), showed an immunological partial homology with the R-factor penicillinases.
Collapse
|
36
|
Winkler U, Timmis K. Pleiotropic mutations in Serratia marcescens which increase the synthesis of certain exocellular proteins and the rate of spontaneous prophage induction. MOLECULAR & GENERAL GENETICS : MGG 1973; 124:197-206. [PMID: 4584940 DOI: 10.1007/bf00293091] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
37
|
Farrar WE, Newsome JK. Mechanism of synergistic effects of beta-lactam antibiotic combinations on gram-negative bacilli. Antimicrob Agents Chemother 1973; 4:109-14. [PMID: 4598215 PMCID: PMC444514 DOI: 10.1128/aac.4.2.109] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
These studies were undertaken to elucidate further the mechanism of synergism of pairs of beta-lactam antibiotics on beta-lactamase-producing gram-negative bacilli. Three strains of gram-negative bacilli which elaborate beta-lactamase enzymes with widely differing properties were employed. The antibacterial effects of beta-lactam antibiotics, singly and in combination, on the three organisms investigated were exactly those which would have been predicted on the basis of the enzymological properties of the beta-lactamases elaborated by these organisms. The findings thus support the hypothesis that the synergistic antibacterial effects of combinations of beta-lactam antibiotics on these organisms were due to inhibition of the enzyme by one of the agents and killing of the organism by the other, which was protected from enzymatic hydrolysis, rather than the alternative possibility that the synergistic effects were due simply to the combined antibacterial actions of the two drugs.
Collapse
|
38
|
Ross GW, Boulton MG. Purification of beta-lactamases on QAE-sephadex. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 309:430-9. [PMID: 4731970 DOI: 10.1016/0005-2744(73)90041-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
39
|
Daoust DR, Onishi HR, Wallick H, Hendlin D, Stapley EO. Cephamycins, a new family of beta-lactam antibiotics: antibacterial activity and resistance to beta-lactamase degradation. Antimicrob Agents Chemother 1973; 3:254-61. [PMID: 4790591 PMCID: PMC444396 DOI: 10.1128/aac.3.2.254] [Citation(s) in RCA: 45] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The susceptibility to some cephalosporin antibiotics and to cephamycin C, a member of a new family of beta-lactam antibiotics, was evaluated for 466 cultures representing 11 different genera or species of gram-negative clinical isolates. The susceptibility of 39 gram-negative cultures known to produce beta-lactamase was also determined. The beta-lactamase activity of a representative group of the clinical isolates and the 39 enzyme producers was studied with the cephalosporins (cephalothin and cephaloridine) and cephamycin C as substrates and was related to the in vitro disc susceptibility to these same antibiotics. The significant resistance to beta-lactamase displayed by the cephamycins is reflected in the kinetics of enzyme activity (K(m) and V(max)) that are reported for the cephalosporins and the cephamycins. Resistance to beta-lactamase is probably one of the reasons that many cephalosporin-resistant cultures are susceptible to cephamycin C.
Collapse
|
40
|
Richmond MH, Sykes RB. The beta-lactamases of gram-negative bacteria and their possible physiological role. Adv Microb Physiol 1973; 9:31-88. [PMID: 4581138 DOI: 10.1016/s0065-2911(08)60376-8] [Citation(s) in RCA: 398] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
41
|
Marshall MJ, Ross GW, Chanter KV, Harris AM. Comparison of the substrate specificities of the -lactamases from Klebsiella aerogenes 1082E and Enterobacter cloacae P99. Appl Microbiol 1972; 23:765-9. [PMID: 4553144 PMCID: PMC380432 DOI: 10.1128/am.23.4.765-769.1972] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A potent beta-lactamase (EC 3.5.2.6) produced by a strain of Klebsiella aerogenes (K. pneumoniae), 1082E, isolated from a hospital patient, has been examined. Its properties were different from those of most gram-negative beta-lactamases previously reported. The enzyme has been partly purified, and its activity against a range of substrates has been compared with that of the enzyme from Enterobacter cloacae (Aerobacter cloacae) P99. The K. aerogenes enzyme, although predominantly a penicillinase, had a wide range of specificity. In addition to hydrolyzing the cephalosporins, it attacked the normally beta-lactamaseresistant compounds methicillin and cloxacillin as well as cephalosporin analogues with the same acyl substituents. The results obtained with the E. cloacae enzyme confirmed its cephalosporinase activity and showed that, unlike the enzyme from K. aerogenes, it was relatively inactive against the penicillins.
Collapse
|
42
|
Wick WE, Preston DA. Biological properties of three 3-heterocyclic-thiomethyl cephalosporin antibiotics. Antimicrob Agents Chemother 1972; 1:221-34. [PMID: 5045468 PMCID: PMC444196 DOI: 10.1128/aac.1.3.221] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Three new cephalosporin antibiotics, prepared by substitution of heterocyclic groups on 7-aminocephalosporanic acid, possess certain desirable chemical or biological properties. All three compounds are active in vitro against a variety of gram-positive and gram-negative bacteria. Minimal inhibitory concentrations (MIC) of these bactericidal antibiotics were not significantly affected by changes in pH or NaCl content of nutrient broth, or by the use of different inoculum sizes. However, agar-dilution MIC values were generally two- to fourfold lower than the MIC values in comparable broth-dilution tests. Stability to cephalosporinase by two of the compounds extended their antibacterial spectra over cephalothin and cephaloridine to include strains of Enterobacter sp. and indole-positive Proteus sp. Binding to serum proteins of the new cephalosporins was intermediate between cephalothin and cephaloridine. Excellent concentrations of the antibiotics were attained in mouse blood, after subcutaneous administration of 20 mg per kg. In vitro biological characteristics of the antibiotics were verified by successful therapy of experimental mouse infections. Regression lines were calculated to show the correlation of agar-dilution MIC values with zones of inhibition by the disc testing procedure. Because each of the three new cephalosporins has certain advantageous properties over cephalothin and cephaloridine, additional toxicological and pharmacological data should be obtained for all three compounds.
Collapse
|
43
|
Neu HC, Winshell EB. Relation of beta-lactamase activity and cellular location to resistance of Enterobacter to penicillins and cephalosporins. Antimicrob Agents Chemother 1972; 1:107-11. [PMID: 4218941 PMCID: PMC444177 DOI: 10.1128/aac.1.2.107] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The Enterobacter species E. aerogenes, E. cloacae, and E. hafnia were examined for resistance to penicillin and cephalosporin derivatives. All were resistant to benzyl penicillin, ampicillin, 6 [d(-)alpha-amino-p-hydroxyphenylacetamido] penicillanic acid, cephaloridine, cephalothin, and cephalexin. A significant number were sensitive to carbenicillin and 6 [d(-)alpha-carboxy-3-thienylacetamido] penicillanic acid. No differences among the three species were noted. The beta-lactamase activity was cell-bound, and was not released by osmotic shock, toluene treatment, or diphenylamine treatment. It was rarely released into the growth medium. The beta-lactamase activity was primarily directed against cephalosporin derivatives. Synthesis of beta-lactamase was chromosomally mediated. Resistance to ampicillin seemed to be partly related to entry of the molecule into the bacteria since exposure to ethylenediaminetetraacetate lowered the minimal inhibitory concentration.
Collapse
|
44
|
Pitton JS. Mechanisms of bacterial resistance to antibiotics. ERGEBNISSE DER PHYSIOLOGIE, BIOLOGISCHEN CHEMIE UND EXPERIMENTELLEN PHARMAKOLOGIE 1972; 65:15-93. [PMID: 4566421 DOI: 10.1007/3-540-05814-1_2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
45
|
Farrar WE, Krause JM. Relationship Between β-Lactamase Activity and Resistance of
Enterobacter
to Cephalothin. Infect Immun 1970; 2:610-6. [PMID: 16557885 PMCID: PMC416058 DOI: 10.1128/iai.2.5.610-616.1970] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The relationship between cephalosporin β-lactamase activity and resistance to cephalothin was investigated in strains of
Enterobacter cloacae
and
E. aerogenes
. β-Lactamase activity was detected in all strains, but a quantitative correlation between amount of β-lactamase activity and level of resistance to cephalothin was not observed. Permeability barriers to cephalothin were observed and varied from strain to strain. β-Lactamase activity was increased by growing organisms in the presence of penicillin G. These enzymes hydrolyzed cephalosporins more rapidly than penicillins. Penicillinase-resistant penicillins, especially those of the isoxazolyl series, effectively inhibited
Enterobacter
β-lactamase. A synergistic antibacterial effect was observed when organisms were exposed to cephalothin and oxacillin in combination, and the resistance of even very small inocula to cephalothin was reduced by addition of oxacillin. Oxacillin probably exerts its effect by inhibiting β-lactamase at an intracellular site. Intracellular β-lactamase may make an important contribution to the resistance of even small inocula of gram-negative bacilli to cephalosporin and penicillin antibiotics. Although β-lactamase plays a significant role in the resistance of
Enterobacter
to cephalothin, other factors, such as permeability barriers, also participate in determining the level of resistance.
Collapse
Affiliation(s)
- W E Farrar
- Department of Preventive Medicine and Community Health and Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30303
| | | |
Collapse
|
46
|
|
47
|
Sassiver M, Lewis A. Structure–Activity Relationships Among Semisynthetic Cephalosporins. ADVANCES IN APPLIED MICROBIOLOGY 1970. [DOI: 10.1016/s0065-2164(08)70404-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
48
|
Zabransky RJ, Hall JW, Day FE, Needham GM. Klebsiella, Enterobacter, and Serratia: biochemical differentiation and susceptibility to ampicillin and three cephalosporin derivatives. Appl Microbiol 1969; 18:198-203. [PMID: 4896880 PMCID: PMC377943 DOI: 10.1128/am.18.2.198-203.1969] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Three hundred twenty-nine strains of the tribe Klebsielleae were compared by several biochemical tests and by susceptibility to selected antibiotics. Biochemical tests included urease, amino acid decarboxylase, and hydrogen sulfide production; fermentation of lactose and dextrose; motility; and tests in the IMViC (indole, methyl red, Voges-Proskauer, citrate) series. The isolates were: Klebsiella species, 67.5%; Enterobacter species, 28%, and Serratia species, 4.5%. Minimal inhibitory concentrations of cephaloridine, cephalothin, and a new cephalosporin, cephalexin, and of ampicillin were determined by the agar dilution procedure. Cephalosporins at 20 mug/ml or less inhibited 90% of the Klebsiella strains but only 15% of the Enterobacter strains. Ampicillin inhibited 27% of Enterobacter strains and 17% of Klebsiella strains. Serratia isolates were insensitive to the cephalosporins and ampicillin. The results suggest that precise identification of this group to the generic level can be accomplished readily in the clinical laboratory and that such information is helpful in the preliminary selection of an antibiotic for treatment of clinical infections.
Collapse
|
49
|
Fleming PC, Goldner M, Glass DG. Inhibition of Aerobacter cephalosporin beta-lactamase by penicillins. J Bacteriol 1969; 98:394-7. [PMID: 5784199 PMCID: PMC284827 DOI: 10.1128/jb.98.2.394-397.1969] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Cephalosporinase (beta-lactamase) was obtained from cell washings of Aerobacter (Enterobacter) cloacae as a highly active preparation. An alkalimetric method was used to determine the enzyme activity and to estimate its inhibition by 6-amino-penicillanic acid derivatives. Their order of decreasing inhibitory effect was as follows: cloxacillin, oxacillin, methicillin, ampicillin, and penicillin G. We found that 2 to 3 ng of cloxacillin per ml was sufficient to decrease the enzyme activity by 50% in the presence of 400 mug of cephalosporin C per ml. Cloxacillin exerted a potentiating effect on the inhibition of the E. cloacae organisms by cephalosporin C.
Collapse
|
50
|
Parker RH, Paterson PY. Antimicrobial agents. Selection and use. JOURNAL OF CHRONIC DISEASES 1969; 21:719-36. [PMID: 4306037 DOI: 10.1016/0021-9681(69)90021-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|