Morphological changes in penicillin-resistant Streptococcus pneumoniae and β-lactamase-nonproducing, ampicillin-resistant Haemophilus influenzae after exposure to oral antibacterial agents

Naoko Chiba, Miyuki Morozumi, Kimiko Ubukata

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Morphological changes in penicillin-resistant Streptococcus pneumoniae (PRSP) and β-lactamase-nonproducing, ampicillin-resistant Haemophilus influenzae (BLNAR) after exposure to oral antibacterial agents could be observed over time under a phase-contrast microscope. Morphological changes in BLNAR were also observed using a scanning electron microscope. The organisms used in this study were ME19F strain identified as genotypic(g) gPRSP (serotype: 19F) and JPH002 strain identified as gBLNAR (serotype: b). The antibacterial agents used were amoxicillin (AMPC), cefditoren (CDTR), tebipenem (TBPM), and tosufloxacin (TFLX). The concentration of each antibacterial agent to which the bacteria were exposed was set at the blood level one hour after Cmax when administered to children at the usual dose. Bacteriolysis of gPRSP cells started after exposure of only 20 minutes to TBPM, and 90%) of the cells were lysed within 2 hours. A high bactericidal action of TBPM on gPRSP was supported by these findings. When gBLNAR was exposed to AMPC and TBPM, lysis from spheroplasts and cells with vacuoles were sometimes observed. In contrast, after gBLNAR was exposed to CDTR, lysis occurred after marked filamentation in the cells, but after exposure to TFLX, cells deduced to be killed after mild filamentation without lysis. Time-dependent morphological changes that reflect the differences in bactericidal activity and PBP affinity among β-lactams provide beneficial information to select antibacterial agents.

Original languageEnglish
Pages (from-to)323-334
Number of pages12
JournalJapanese Journal of Antibiotics
Volume65
Issue number5
Publication statusPublished - 2012 Oct
Externally publishedYes

Fingerprint

Haemophilus influenzae
Ampicillin
Streptococcus pneumoniae
Penicillins
tosufloxacin
Anti-Bacterial Agents
Bacteriolysis
Spheroplasts
Lactams
Amoxicillin
Vacuoles
Electrons
Bacteria
tebipenem
cefditoren
Serogroup

ASJC Scopus subject areas

  • Pharmacology (medical)
  • Infectious Diseases
  • Microbiology (medical)

Cite this

@article{7d7a07450dd5448d9c9c994f1ed76fb2,
title = "Morphological changes in penicillin-resistant Streptococcus pneumoniae and β-lactamase-nonproducing, ampicillin-resistant Haemophilus influenzae after exposure to oral antibacterial agents",
abstract = "Morphological changes in penicillin-resistant Streptococcus pneumoniae (PRSP) and β-lactamase-nonproducing, ampicillin-resistant Haemophilus influenzae (BLNAR) after exposure to oral antibacterial agents could be observed over time under a phase-contrast microscope. Morphological changes in BLNAR were also observed using a scanning electron microscope. The organisms used in this study were ME19F strain identified as genotypic(g) gPRSP (serotype: 19F) and JPH002 strain identified as gBLNAR (serotype: b). The antibacterial agents used were amoxicillin (AMPC), cefditoren (CDTR), tebipenem (TBPM), and tosufloxacin (TFLX). The concentration of each antibacterial agent to which the bacteria were exposed was set at the blood level one hour after Cmax when administered to children at the usual dose. Bacteriolysis of gPRSP cells started after exposure of only 20 minutes to TBPM, and 90{\%}) of the cells were lysed within 2 hours. A high bactericidal action of TBPM on gPRSP was supported by these findings. When gBLNAR was exposed to AMPC and TBPM, lysis from spheroplasts and cells with vacuoles were sometimes observed. In contrast, after gBLNAR was exposed to CDTR, lysis occurred after marked filamentation in the cells, but after exposure to TFLX, cells deduced to be killed after mild filamentation without lysis. Time-dependent morphological changes that reflect the differences in bactericidal activity and PBP affinity among β-lactams provide beneficial information to select antibacterial agents.",
author = "Naoko Chiba and Miyuki Morozumi and Kimiko Ubukata",
year = "2012",
month = "10",
language = "English",
volume = "65",
pages = "323--334",
journal = "The Journal of antibiotics. Ser. B",
issn = "0368-2781",
publisher = "Japan Antibiotics Research Association",
number = "5",

}

TY - JOUR

T1 - Morphological changes in penicillin-resistant Streptococcus pneumoniae and β-lactamase-nonproducing, ampicillin-resistant Haemophilus influenzae after exposure to oral antibacterial agents

AU - Chiba, Naoko

AU - Morozumi, Miyuki

AU - Ubukata, Kimiko

PY - 2012/10

Y1 - 2012/10

N2 - Morphological changes in penicillin-resistant Streptococcus pneumoniae (PRSP) and β-lactamase-nonproducing, ampicillin-resistant Haemophilus influenzae (BLNAR) after exposure to oral antibacterial agents could be observed over time under a phase-contrast microscope. Morphological changes in BLNAR were also observed using a scanning electron microscope. The organisms used in this study were ME19F strain identified as genotypic(g) gPRSP (serotype: 19F) and JPH002 strain identified as gBLNAR (serotype: b). The antibacterial agents used were amoxicillin (AMPC), cefditoren (CDTR), tebipenem (TBPM), and tosufloxacin (TFLX). The concentration of each antibacterial agent to which the bacteria were exposed was set at the blood level one hour after Cmax when administered to children at the usual dose. Bacteriolysis of gPRSP cells started after exposure of only 20 minutes to TBPM, and 90%) of the cells were lysed within 2 hours. A high bactericidal action of TBPM on gPRSP was supported by these findings. When gBLNAR was exposed to AMPC and TBPM, lysis from spheroplasts and cells with vacuoles were sometimes observed. In contrast, after gBLNAR was exposed to CDTR, lysis occurred after marked filamentation in the cells, but after exposure to TFLX, cells deduced to be killed after mild filamentation without lysis. Time-dependent morphological changes that reflect the differences in bactericidal activity and PBP affinity among β-lactams provide beneficial information to select antibacterial agents.

AB - Morphological changes in penicillin-resistant Streptococcus pneumoniae (PRSP) and β-lactamase-nonproducing, ampicillin-resistant Haemophilus influenzae (BLNAR) after exposure to oral antibacterial agents could be observed over time under a phase-contrast microscope. Morphological changes in BLNAR were also observed using a scanning electron microscope. The organisms used in this study were ME19F strain identified as genotypic(g) gPRSP (serotype: 19F) and JPH002 strain identified as gBLNAR (serotype: b). The antibacterial agents used were amoxicillin (AMPC), cefditoren (CDTR), tebipenem (TBPM), and tosufloxacin (TFLX). The concentration of each antibacterial agent to which the bacteria were exposed was set at the blood level one hour after Cmax when administered to children at the usual dose. Bacteriolysis of gPRSP cells started after exposure of only 20 minutes to TBPM, and 90%) of the cells were lysed within 2 hours. A high bactericidal action of TBPM on gPRSP was supported by these findings. When gBLNAR was exposed to AMPC and TBPM, lysis from spheroplasts and cells with vacuoles were sometimes observed. In contrast, after gBLNAR was exposed to CDTR, lysis occurred after marked filamentation in the cells, but after exposure to TFLX, cells deduced to be killed after mild filamentation without lysis. Time-dependent morphological changes that reflect the differences in bactericidal activity and PBP affinity among β-lactams provide beneficial information to select antibacterial agents.

UR - http://www.scopus.com/inward/record.url?scp=84869854827&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84869854827&partnerID=8YFLogxK

M3 - Article

C2 - 23383434

AN - SCOPUS:84869854827

VL - 65

SP - 323

EP - 334

JO - The Journal of antibiotics. Ser. B

JF - The Journal of antibiotics. Ser. B

SN - 0368-2781

IS - 5

ER -