scholarly journals Postneurosurgical Meningitis Due to Proteus penneri with Selection of a Ceftriaxone-Resistant Isolate: Analysis of Chromosomal Class A β-Lactamase HugA and its LysR-Type Regulatory Protein HugR

2002 ◽  
Vol 46 (1) ◽  
pp. 216-219 ◽  
Author(s):  
Nadia Liassine ◽  
Stéphanie Madec ◽  
Béatrice Ninet ◽  
Catherine Metral ◽  
Martine Fouchereau-Peron ◽  
...  
Keyword(s):  
Regulatory Protein ◽  
Transcriptional Regulator ◽  
Pulsed Field Gel Electrophoresis ◽  
Resistant Isolate ◽  
Proteus Vulgaris ◽  
Class A ◽  
Lactamase Gene ◽  
Proteus Penneri ◽  
Selection Of ◽  
Lysr Family

ABSTRACT We report on a case of a postneurosurgical meningitis due to ceftriaxone-susceptible Proteus penneri, with selection of a ceftriaxone-resistant isolate following treatment with ceftriaxone. The isolates presented identical patterns by pulsed-field gel electrophoresis and produced a single β-lactamase named HugA with an isoelectric point of 6.7. The ceftriaxone-resistant isolate hyperproduced the β-lactamase (increase in the level of production, about 90-fold). The sequences of the hugA β-lactamase gene and its regulator, hugR, were identical in both P. penneri strains and had 85.96% homology with those of Proteus vulgaris. The HugA β-lactamase belongs to molecular class A, and the transcriptional regulator HugR belongs to the LysR family.

scholarly journals Novel Class A β-Lactamase Sed-1 fromCitrobacter sedlakii: Genetic Diversity of β-Lactamases within the Citrobacter Genus

2001 ◽  
Vol 45 (8) ◽  
pp. 2287-2298 ◽  
Author(s):  
Stephanie Petrella ◽  
Dominique Clermont ◽  
Isabelle Casin ◽  
Vincent Jarlier ◽  
Wladimir Sougakoff
Keyword(s):  
Dna Hybridization ◽  
Klebsiella Oxytoca ◽  
Transcriptional Regulator ◽  
Enterobacter Cloacae ◽  
Clinical Strain ◽  
Proteus Vulgaris ◽  
Class A ◽  
Gene Coding ◽  
Quinolone Antibiotics ◽  
Reference Strains

ABSTRACT Citrobacter sedlakii 2596, a clinical strain resistant to aminopenicillins, carboxypenicillins, and early cephalosporins such as cephalothin, but remaining susceptible to acylureidopenicillins, carbapenems, and later cephalosporins such as cefotaxime, was isolated from the bile of a patient treated with β-lactam and quinolone antibiotics. The isolate produced an inducible class A β-lactamase of pI 8.6, named Sed-1, which was purified. Characterized by a molecular mass of 30 kDa, Sed-1 preferentially hydrolyzed benzylpenicillin, cephalothin, and cloxacillin. The corresponding gene,bla Sed-1, was cloned and sequenced. Its deduced amino acid sequence shared more than 60% identity with the chromosome-encoded β-lactamases from Citrobacter koseri(formerly C. diversus) (84%), Klebsiella oxytoca (74%), Serratia fonticola (67%), andProteus vulgaris (63%) and 71% identity with the plasmid-mediated enzyme MEN-1. A gene coding for a LysR transcriptional regulator was found upstream from bla Sed-1. This regulator, named SedR, displayed 90% identity with the AmpR sequence of the chromosomal β-lactamase from C. koseriand 63 and 50% identity with the AmpR sequences of P. vulgaris and Enterobacter cloacae, respectively. By using DNA-DNA hybridization, a bla Sed-1-like gene was identified in two reference strains, C. sedlakii(CIP-105037) and Citrobacter rodentium (CIP-104675), but not in the 18 strains of C. koseri studied. Two DNA fragments were amplified and sequenced from the reference strains ofC. sedlakii CIP-105037 and C. rodentiumCIP-104675 using two primers specific forbla Sed-1. They shared 98 and 80% identity withbla Sed-1, respectively, confirming the diversity of the chromosomally encoded class A β-lactamases found inCitrobacter.

scholarly journals Characterization of IMI-1 beta-lactamase, a class A carbapenem-hydrolyzing enzyme from Enterobacter cloacae.

1996 ◽  
Vol 40 (9) ◽  
pp. 2080-2086 ◽  
Author(s):  
B A Rasmussen ◽  
K Bush ◽  
D Keeney ◽  
Y Yang ◽  
R Hare ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Clavulanic Acid ◽  
Regulatory Protein ◽  
Enterobacter Cloacae ◽  
Amino Acid Sequences ◽  
Beta Lactamase ◽  
Gene Encoding ◽  
Class A ◽  
Lactamase Gene

In 1984, a year prior to the U.S. approval of imipenem for clinical use, a wound isolate and a bile isolate of Enterobacter cloacae were obtained from two patients in a California hospital. These isolates were resistant to imipenem, penicillins, and inhibitor combinations; early cephalosporins such as cephalothin, cefamandole, and cefoxitin; and cefoperazone. However, they were susceptible (MICs, < 4 micrograms/ml) to cefotaxime, ceftriaxone, ceftazidime, and moxalactam. Both strains produced an apparent TEM-1 beta-lactamase; an inducible NmcA-type imipenem-hydrolyzing beta-lactamase, IMI-1, with a pl of 7.05; and an inducible beta-lactamase with a pI of 8.1, typical of an E. cloacae AmpC beta-lactamase. Purified IMI-1 hydrolyzed imipenem and benzylpenicillin at modest rates, but more slowly than cephaloridine. The enzyme was inhibited by clavulanic acid and tazobactam. EDTA did not inhibit the cephaloridine-hydrolyzing activity. The beta-lactamase gene encoding IMI-1, imiA1, was cloned from E. cloacae 1413B. Sequence analysis identified the imiA1 gene as encoding a class A serine beta-lactamase. Both the imiA1 DNA and encoded amino acid sequences shared greater than 95% identity with the NmcA gene and its encoded protein. DNA sequence analysis also identified a gene upstream of imiA1 that shares > 95% identity with nmcR and that may encode a regulatory protein. In conclusion, IMI-1, a carbapenem-hydrolyzing beta-lactamase inhibited by clavulanic acid, was identified as a group 2f, class A, carbapenem-hydrolyzing cephalosporinase.

scholarly journals Identification of a Chromosome-Borne Expanded-Spectrum Class A β-Lactamase from Erwinia persicina

2002 ◽  
Vol 46 (11) ◽  
pp. 3401-3405 ◽  
Author(s):  
Sophie Vimont ◽  
Laurent Poirel ◽  
Thierry Naas ◽  
Patrice Nordmann
Keyword(s):  
Reference Strain ◽  
Klebsiella Oxytoca ◽  
Amino Acid Identity ◽  
Relative Molecular Mass ◽  
Antibiotic Resistant ◽  
Class A ◽  
Kluyvera Ascorbata ◽  
Lactamase Gene ◽  
Proteus Penneri ◽  
Erwinia Persicina

ABSTRACT From whole-cell DNA of an enterobacterial Erwinia persicina reference strain that displayed a penicillinase-related antibiotic-resistant phenotype, a β-lactamase gene was cloned and expressed in Escherichia coli. It encoded a clavulanic-acid-inhibited Ambler class A β-lactamase, ERP-1, with a pI value of 8.1 and a relative molecular mass of ca. 28 kDa. ERP-1 shared 45 to 50% amino acid identity with the most closely related enzymes, the chromosomally encoded enzymes from Citrobacter koseri, Kluyvera ascorbata, Kluyvera cryocrescens, Klebsiella oxytoca, Proteus vulgaris, Proteus penneri, Rahnella aquatilis, Serratia fonticola, Yersinia enterocolitica, and the plasmid-mediated enzymes CTX-M-8 and CTX-M-9. The substrate profile of the noninducible ERP-1 was similar to that of these β-lactamases. ERP-1 is the first extended-spectrum β-lactamase from an enterobacterial species that is plant associated and plant pathogenic.

scholarly journals GES-2, a Class A β-Lactamase fromPseudomonas aeruginosa with Increased Hydrolysis of Imipenem

2001 ◽  
Vol 45 (9) ◽  
pp. 2598-2603 ◽  
Author(s):  
Laurent Poirel ◽  
Gerhard F. Weldhagen ◽  
Thierry Naas ◽  
Christophe De Champs ◽  
Michael G. Dove ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Amino Acid Change ◽  
Blood Cultures ◽  
Class A ◽  
Omega Loop ◽  
Cephalosporin Resistance ◽  
Lactamase Gene ◽  
Hydrolysis Of

ABSTRACT Pseudomonas aeruginosa GW-1 was isolated in 2000 in South Africa from blood cultures of a 38-year-old female who developed nosocomial pneumonia. This isolate harbored a self-transferable ca. 100-kb plasmid that conferred an expanded-spectrum cephalosporin resistance profile associated with an intermediate susceptibility to imipenem. A β-lactamase gene, bla GES-2, was cloned from whole-cell DNA of P. aeruginosa GW-1 and expressed in Escherichia coli. GES-2, with a pI value of 5.8, hydrolyzed expanded-spectrum cephalosporins, and its substrate profile was extended to include imipenem compared to that of GES-1, identified previously in Klebsiella pneumoniae. GES-2 activity was less inhibited by clavulanic acid, tazobactam and imipenem than GES-1. The GES-2 amino acid sequence differs from that of GES-1 by a glycine-to-asparagine substitution in position 170 located in the omega loop of Ambler class A enzymes. This amino acid change may explain the extension of the substrate profile of the plasmid-encoded β-lactamase GES-2.

scholarly journals Characterization of beta-lactamase gene blaPER-2, which encodes an extended-spectrum class A beta-lactamase.

1996 ◽  
Vol 40 (3) ◽  
pp. 616-620 ◽  
Author(s):  
A Bauernfeind ◽  
I Stemplinger ◽  
R Jungwirth ◽  
P Mangold ◽  
S Amann ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Beta Lactamase ◽  
Reading Frame ◽  
Beta Lactamases ◽  
Class A ◽  
Extended Spectrum ◽  
The Family ◽  
Extended Spectrum Beta Lactamases ◽  
Lactamase Gene

Plasmidic extended-spectrum beta-lactamases of Ambler class A are mostly inactive against ceftibuten. Salmonella typhimurium JMC isolated in Argentina harbors a bla gene located on a plasmid (pMVP-5) which confers transferable resistance to oxyiminocephalosporins, aztreonam, and ceftibuten. The beta-lactamase PER-2 (formerly ceftibutenase-1; CTI-1) is highly susceptible to inhibition by clavulanate and is located at a pI of 5.4 after isoelectric focusing. The blaPER-2 gene was cloned and sequenced. The nucleotide sequence of a 2.2-kb insert in vector pBluescript includes an open reading frame of 927 bp. Comparison of the deduced amino acid sequence of PER-2 with those of other beta-lactamases indicates that PER-2 is not closely related to TEM or SHV enzymes (25 to 26% homology). PER-2 is most closely related to PER-1 (86.4% homology), an Ambler class A enzyme first detected in Pseudomonas aeruginosa. An enzyme with an amino acid sequence identical to that of PER-1, meanwhile, was found in various members of the family Enterobacteriaceae isolated from patients in Turkey. Our data indicate that PER-2 and PER-1 represent a new group of Ambler class A extended-spectrum beta-lactamases. PER-2 so far has been detected only in pathogens (S. typhimurium, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis) isolated from patients in South America, while the incidence of PER-1-producing strains so far has been restricted to Turkey, where it occurs both in members of the family Enterobacteriaceae and in P. aeruginosa.

scholarly journals Where Do You Sit in Class? A Study of Spatial Positioning During Two Courses of Different Duration

2017 ◽  
Vol 1 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Gilles Clément ◽  
Angie Bukley
Keyword(s):  
Academic Programs ◽  
Lecture Hall ◽  
Objective Data ◽  
Class A ◽  
Seating Location ◽  
Spatial Positioning ◽  
Confined Environment ◽  
Hourly Basis ◽  
Crowded Environment ◽  
Selection Of

The objective of this study was to study the selection of seat location by individuals in a group in a confined environment and to identify the factors leading people to prefer one location to another. We analyzed the seating location of students in a lecture hall over the course of two academic programs of different durations (19 days and 44 days). The goal was to determine the rate at which participants would settle into a specific seat location. Unobtrusive photography was used to collect objective data on an hourly basis. Results showed that in both courses participants began to settle into a specific location from the second day of class. Twenty percent of the participants had settled after 4-7 days or 15.5 hours in class. Settling continued for the duration of the shorter course. However, in the longer course settling stopped after 28.5 days on average. The plateau in the number of settlers depended on the number of days, not on the time actually spent in class. At the end of the longer course 52.5% of the participants had settled, compared to 38.9% in the shorter course. Settling into the same seat location can be interpreted as a strategy to establish a personal territory. These results indicate that about half of a cohort expresses the need for establishing a personal territory when in a confined and crowded environment, and this process takes about one month.

scholarly journals Recovery of active beta-lactamases from Proteus vulgaris and RTEM-1 hybrid by random mutagenesis by using a dnaQ strain of Escherichia coli.

1996 ◽  
Vol 40 (9) ◽  
pp. 2152-2159 ◽  
Author(s):  
S M Hosseini-Mazinani ◽  
E Nakajima ◽  
Y Ihara ◽  
K Z Kameyama ◽  
K Sugimoto
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Random Mutagenesis ◽  
Amino Acid Residues ◽  
Proteus Vulgaris ◽  
Coding Region ◽  
Beta Lactamases ◽  
Functional Roles ◽  
Hybrid Genes ◽  
Lactamase Gene

Proteus vulgaris and RTEM-1 beta-lactamases that belong to molecular class A with 37% amino acid similarity were examined to find the relationship between amino acid residues and activity of enzymes. MICs of ampicillin were > 2,000 micrograms/ml for Escherichia coli cells producing these enzymes. We have made 18 hybrid genes by substituting the coding region of the P. vulgaris beta-lactamase gene with the equivalent portions from the RTEM-1 gene. Most of these hybrids produced inactive proteins, but a few hybrid enzymes had partial or trace activity. From one of the hybrid genes (MIC of ampicillin, 100 micrograms/ml), we recovered three kinds of active mutants which provided ampicillin MICs of 1,000 micrograms/ml by the selection of spontaneous mutations in a dnaQ strain of E. coli. In these mutants, Leu-148, Met-182, and Tyr-274 were replaced with Val, Thr, and His, respectively. These amino acids have not been identified as residues with functional roles in substrate hydrolysis. Furthermore, from these hybrid mutants, we obtained a second set of mutants which conferred ampicillin MICs of 1,500 micrograms/ml. Interestingly, the second mutations were limited to these three amino acid substitutions. These amino acid residues which do not directly interact with substrates have an effect on enzyme activity. These mutant enzymes exhibited lower K(m) values for cephaloridine than both parental enzymes.

scholarly journals Frequency of BKC-1-Producing Klebsiella Species Isolates

2016 ◽  
Vol 60 (8) ◽  
pp. 5044-5046 ◽  
Author(s):  
Willames M. B. S. Martins ◽  
Adriana G. Nicoletti ◽  
Silvia R. Santos ◽  
Jorge L. M. Sampaio ◽  
Ana C. Gales
Keyword(s):  
Clonal Complex ◽  
Pulsed Field Gel Electrophoresis ◽  
Beta Lactam ◽  
Klebsiella Species ◽  
Content Type ◽  
Beta Lactamases ◽  
New Class ◽  
Class A ◽  
Genes Encoding ◽  
Extended Spectrum Beta Lactamases

ABSTRACTBKC-1 is a new class A serine carbapenemase that was recently identified inKlebsiella pneumoniaeclinical isolates. The principal objective of this study was to evaluate the frequency ofblaBKC-1by testing a collection ofKlebsiellaisolates. Only 2 of 635Klebsiellaisolates (0.3%) carriedblaBKC-1. The two BKC-1-producing isolates belonged to clonal complex 442 and possessed identical pulsed-field gel electrophoresis patterns. TheblaBKC-1gene was inserted into a 10-kb plasmid that was identical to the previously reported plasmid, p60136. The BKC-producingK. pneumoniaeisolates presented also possessed other mechanisms for beta-lactam resistance, such as genes encoding extended-spectrum beta-lactamases and mutations in the genesompK35andompK36, encoding the major porins.

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