scholarly journals Activities of Ceftobiprole and Other β-Lactams against Streptococcus pneumoniae Clinical Isolates from the United States with Defined Substitutions in Penicillin-Binding Proteins PBP 1a, PBP 2b, and PBP 2x

2006 ◽  
Vol 50 (7) ◽  
pp. 2530-2532 ◽  
Author(s):  
Todd A. Davies ◽  
Wenchi Shang ◽  
Karen Bush

ABSTRACT The activities of ceftobiprole and other β-lactams were examined with 30 Streptococcus pneumoniae isolates containing multiple pbp1a, pbp2b, and pbp2x mutations. The highest ceftobiprole MIC was 1 μg/ml, while the comparator MICs were 16 to 64 μg/ml. Fifty percent inhibitory concentrations for penicillin-binding protein 2x were 0.5 μg/ml (ceftobiprole) and 4 μg/ml (ceftriaxone) in a penicillin- and ceftriaxone-resistant isolate.

2007 ◽  
Vol 51 (9) ◽  
pp. 3404-3406 ◽  
Author(s):  
Cheng-Hsun Chiu ◽  
Lin-Hui Su ◽  
Yhu-Chering Huang ◽  
Jui-Chia Lai ◽  
Hsiu-Ling Chen ◽  
...  

ABSTRACT The rate of nonsusceptibility of penicillin-resistant Streptococcus pneumoniae strains to ceftriaxone increased significantly in Taiwan in 2005. Approximately 90% of the ceftriaxone-nonsusceptible isolates were found to be of four major serotypes (serotypes 6B, 14, 19F, and 23F). Seven amino acid alterations in the penicillin-binding protein 2B transpeptidase-encoding region specifically contributed to the resistance.


2002 ◽  
Vol 46 (12) ◽  
pp. 3744-3749 ◽  
Author(s):  
Satoshi Ameyama ◽  
Shoichi Onodera ◽  
Masahiro Takahata ◽  
Shinzaburo Minami ◽  
Nobuko Maki ◽  
...  

ABSTRACT Neisseria gonorrhoeae strains with reduced susceptibility to cefixime (MICs, 0.25 to 0.5 μg/ml) were isolated from male urethritis patients in Tokyo, Japan, in 2000 and 2001. The resistance to cephems including cefixime and penicillin was transferred to a susceptible recipient, N. gonorrhoeae ATCC 19424, by transformation of the penicillin-binding protein 2 gene (penA) that had been amplified by PCR from a strain with reduced susceptibility to cefixime (MIC, 0.5 μg/ml). The sequences of penA in the strains with reduced susceptibilities to cefixime were different from those of other susceptible isolates and did not correspond to the reported N. gonorrhoeae penA gene sequences. Some regions in the transpeptidase-encoding domain in this penA gene were similar to those in the penA genes of Neisseria perflava (N. sicca), Neisseria cinerea, Neisseria flavescens, and Neisseria meningitidis. These results showed that a mosaic-like structure in the penA gene conferred reductions in the levels of susceptibility of N. gonorrhoeae to cephems and penicillin in a manner similar to that found for N. meningitidis and Streptococcus pneumoniae.


1982 ◽  
Vol 152 (3) ◽  
pp. 1042-1048
Author(s):  
A Rousset ◽  
M Nguyen-Distèche ◽  
R Minck ◽  
J M Ghuysen

The originally penicillin-induced, wall-less stable L-forms of Proteus vulgaris P18, isolated by Tulasne in 1949 and since then cultured in he absence of penicillin, have kept the ability to synthesize the seven penicillin-binding proteins and the various DD- and LD-peptidase activities found in the parental bacteria and known to be involved in wall peptidoglycan metabolism. The stable L-forms, however, secrete during growth both the highly penicillin-sensitive, DD-carboxy-peptidase-transpeptidase penicillin-binding protein PBP4 (which in normal bacteria is relatively loosely bound to the plasma membrane) and the penicillin-insensitive LD-carboxypeptidase (which in normal bacteria is located in the periplasmic region).


2008 ◽  
Vol 53 (3) ◽  
pp. 1238-1241 ◽  
Author(s):  
Tetsufumi Koga ◽  
Chika Sugihara ◽  
Masayo Kakuta ◽  
Nobuhisa Masuda ◽  
Eiko Namba ◽  
...  

ABSTRACT Tomopenem (formerly CS-023), a novel 1β-methylcarbapenem, exhibited high affinity for penicillin-binding protein (PBP) 2 in Staphylococcus aureus, PBP 2 in Escherichia coli, and PBPs 2 and 3 in Pseudomonas aeruginosa, which are considered major lethal targets. Morphologically, tomopenem induced spherical forms in E. coli and short filamentation with bulges in P. aeruginosa, which correlated with the drug's PBP profiles. The potential of resistance of these bacteria to tomopenem was comparable to that to imipenem.


2010 ◽  
Vol 54 (11) ◽  
pp. 4945-4947 ◽  
Author(s):  
Stephen G. Tristram ◽  
Rachael Littlejohn ◽  
Richard S. Bradbury

ABSTRACT Plasmid pB1000 is a small replicon recently identified as bearing bla ROB-1 in animal and human Pasteurellaceae in Spain. We identified pB1000 in 11 bla ROB-1-positive Australian and North American Haemophilus influenzae isolates, suggesting a wider role for pB1000 in disseminating bla ROB-1. Native H. influenzae conjugative elements can mobilize plasmids similar to pB1000 at a low frequency of 10−8, and this might account for the infrequency of bla ROB-1 compared to the rate of occurrence of bla TEM-1. Altered penicillin-binding protein 3 was associated with an increased cefaclor MIC in 3 isolates.


Author(s):  
Tsubasa Ikeda ◽  
Rihito Suzuki ◽  
Wanchun Jin ◽  
Jun-ichi Wachino ◽  
Yoshichika Arakawa ◽  
...  

Streptococcus pyogenes (group A Streptococcus , GAS) has long been regarded as being susceptible to β-lactams. However, amino acid substitutions in penicillin-binding protein (PBP)2X conferring reduced in vitro β-lactam susceptibility have been indicated since 2019 in the United States and Iceland. Here, we report the first isolation of Streptococcus pyogenes possessing the PBP2X substitution conferring reduced in vitro β-lactam susceptibility in Asia; however, the MICs were below the “susceptible” breakpoint of the CLSI.


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