scholarly journals Effect of mupirocin in Helicobacter pylori in vitro

2021 ◽  
Vol 8 (1) ◽  
pp. 160-165
Author(s):  
Masaaki Minami ◽  
Takafumi Ando ◽  
Hidemi Goto ◽  
Michio Ohta
Keyword(s):  
Helicobacter Pylori ◽  
Bactericidal Effect ◽  
Dependent Manner ◽  
Antibiotic Effect ◽  
Resistant Strains ◽  
Kill Curve ◽  
H Pylori ◽  
Time Kill ◽  
Post Antibiotic Effect

Mupirocin (MUP) is an effective antibiotic against MRSA. Its bactericidal effect is stable under acid condition. By validating its antibacterial effect of Helicobacter pylori, we try to clarify MUP effect on H. pylori. The present study was conducted to investigate the effect of MUP on clarithromycin (CLR) / metronidazole (MNZ) -resistant and -susceptible strains of H. pylori, the time-kill effect of MUP, and the post antibiotic effect (PAE). We investigated the minimal inhibitory concentration (MIC) and the minimal bactericidal effect (MBC) of MUP against 140 H. pylori, which include clinical strains, ATCC43504, 26695 and J99. Ten of them were CLR -resistant strains and 3 were MNZ-resistant strains. The MIC90 and MBC of MUP on all 140 strains is 0.064 μg / ml, and 0.1 μg / ml, respectively. There were no differences of MUP effect between susceptible and resistant strains either for CLR or MNZ. Time-kill curve test and PAE test of MUP on ATCC43504 were performed. By adding MUP, time-kill curve showed that bacterial quantities decreased in dose and time-dependent manner. No viable colony was found after 12-hour culture with 0.1 μg / ml MUP. The value of PAE is 12. MUP is a potential effective antibiotic for H. pylori even those for CLR / MNZ -resistant strains.

scholarly journals In Vitro Anti-Helicobacter pyloriActivities of New Rifamycin Derivatives, KRM-1648 and KRM-1657

1999 ◽  
Vol 43 (5) ◽  
pp. 1072-1076 ◽  
Author(s):  
Junko K. Akada ◽  
Mutsunori Shirai ◽  
Kenji Fujii ◽  
Kiwamu Okita ◽  
Teruko Nakazawa
Keyword(s):  
Helicobacter Pylori ◽  
Cell Lysis ◽  
Antimicrobial Activities ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Bactericidal Activities ◽  
H Pylori ◽  
Time Kill

ABSTRACT The new rifamycin derivatives KRM-1657 and KRM-1648 were evaluated for their in vitro antimicrobial activities against 44 strains ofHelicobacter pylori. Although the drugs were not very active against other gram-negative bacteria, the MICs at which 90% of isolates are inhibited for these drugs were lower (0.002 and 0.008 μg/ml, respectively) than those of amoxicillin and rifampin forH. pylori. Time-kill studies revealed that the bactericidal activities of these agents were due to cell lysis. The results presented here indicate that these new rifamycin derivatives may be useful for the eradication of H. pylori infections.

scholarly journals In Vitro Activity of a Novel Antimicrobial Agent, TG44, for Treatment of Helicobacter pylori Infection

2006 ◽  
Vol 50 (9) ◽  
pp. 3062-3069 ◽  
Author(s):  
Osamu Kamoda ◽  
Kinsei Anzai ◽  
Jun-ichi Mizoguchi ◽  
Masatoshi Shiojiri ◽  
Toshiharu Yanagi ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antibacterial Activity ◽  
Bactericidal Activity ◽  
Structural Formula ◽  
Therapeutic Modalities ◽  
Resistant Strains ◽  
H Pylori ◽  
Ph Range ◽  
Drug Resistant Strains

ABSTRACT Due to concerns about the current therapeutic modalities for Helicobacter pylori infection, e.g., the increased emergence of drug-resistant strains and the adverse reactions of drugs currently administered, there is a need to develop an anti-H. pylori agent with higher efficacy and less toxicity. The antibacterial activity of TG44, an anti-H. pylori agent with a novel structural formula, against 54 clinical isolates of H. pylori was examined and compared with those of amoxicillin (AMX), clarithromycin (CLR), and metronidazole (MNZ). Consequently, TG44 inhibited the growth of H. pylori in an MIC range of 0.0625 to 1 μg/ml. The MIC ranges of AMX, CLR, and MNZ were 0.0078 to 8 μg/ml, 0.0156 to 64 μg/ml, and 2 to 128 μg/ml, respectively. The antibacterial activity of TG44 against AMX-, CLR-, and MNZ-resistant strains was nearly comparable to that against drug-susceptible ones. In a pH range of 3 to 7, TG44 at 3.13 to 12.5 μg/ml exhibited potent bactericidal activity against H. pylori in the stationary phase of growth as early as 1 h after treatment began, in contrast to AMX, which showed no bactericidal activity at concentrations of up to 50 μg/ml at the same time point of treatment. TG44 at 25 μg/ml exhibited no antibacterial activity against 13 strains of aerobic bacteria, suggesting that its antibacterial activity against H. pylori is potent and highly specific. The present study indicated that TG44 possesses antibacterial activity which manifests quickly and is potentially useful for eradicating not only the antibiotic-susceptible but also the antibiotic-resistant strains of H. pylori by monotherapy.

scholarly journals Time-kill curve analysis and pharmacodynamic functions for in vitro evaluation of antimicrobials againstNeisseria gonorrhoeae

2015 ◽  
Author(s):  
Sunniva Foerster ◽  
Magnus Unemo ◽  
Lucy J Hathaway ◽  
Nicola Low ◽  
Christian L Althaus
Keyword(s):  
Bactericidal Effect ◽  
World Health ◽  
Transmitted Infection ◽  
In Vitro Evaluation ◽  
Sexually Transmitted ◽  
Dosing Strategies ◽  
Kill Curve ◽  
Health Organization ◽  
Time Kill

Gonorrhea is a sexually transmitted infection caused by the Gram-negative bacteriumNeisseria gonorrhoeae. Resistance to first-line empirical monotherapy has emerged, so robust methods are needed to appropriately evaluate the activity of existing and novel antimicrobials against the bacterium. Pharmacodynamic functions, which describe the relationship between the concentration of antimicrobials and the bacterial net growth rate, provide more detailed information than the MIC only. In this study, a novel standardized in vitro time-kill curve assay was developed. The assay was validated using five World Health OrganizationN. gonorrhoeaereference strains and various concentrations of ciprofloxacin, and then the activity of nine antimicrobials with different target mechanisms were examined against a highly susceptible clinical wild type isolate (cultured in 1964). From the time-kill curves, the bacterial net growth rates at each antimicrobial concentration were estimated. Finally, a pharmacodynamic function was fitted to the data, resulting in four parameters that describe the pharmacodynamic properties of each antimicrobial. Ciprofloxacin resistance determinants shifted the pharmacodynamic MIC (zMIC) and attenuated the bactericidal effect at antimicrobial concentrations above the zMIC. Ciprofloxacin, spectinomycin and gentamicin had the strongest bactericidal effect during the first six hours of the assay. Only tetracycline and chloramphenicol showed a purely bacteriostatic effect. The pharmacodynamic functions differed between antimicrobials, showing that the effect of the drugs at concentrations below and above the MIC vary widely. In conclusion,N. gonorrhoeaetime-kill curve experiments analyzed with pharmacodynamic functions have potential for in vitro evaluation of new and existing antimicrobials and dosing strategies to treat gonorrhea.

scholarly journals Curcumin Oxidation Is Required for Inhibition of Helicobacter pylori Growth, Translocation and Phosphorylation of Cag A

2021 ◽  
Vol 11 ◽  
Author(s):  
Ashwini Kumar Ray ◽  
Paula B. Luis ◽  
Surabhi Kirti Mishra ◽  
Daniel P. Barry ◽  
Mohammad Asim ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Growth Inhibition ◽  
Mrna Expression ◽  
Host Protein ◽  
Dependent Manner ◽  
Gene Encoding ◽  
E Coli ◽  
H Pylori

Curcumin is a potential natural remedy for preventing Helicobacter pylori-associated gastric inflammation and cancer. Here, we analyzed the effect of a phospholipid formulation of curcumin on H. pylori growth, translocation and phosphorylation of the virulence factor CagA and host protein kinase Src in vitro and in an in vivo mouse model of H. pylori infection. Growth of H. pylori was inhibited dose-dependently by curcumin in vitro. H. pylori was unable to metabolically reduce curcumin, whereas two enterobacteria, E. coli and Citrobacter rodentium, which efficiently reduced curcumin to the tetra- and hexahydro metabolites, evaded growth inhibition. Oxidative metabolism of curcumin was required for the growth inhibition of H. pylori and the translocation and phosphorylation of CagA and cSrc, since acetal- and diacetal-curcumin that do not undergo oxidative transformation were ineffective. Curcumin attenuated mRNA expression of the H. pylori virulence genes cagE and cagF in a dose-dependent manner and inhibited translocation and phosphorylation of CagA in gastric epithelial cells. H. pylori strains isolated from dietary curcumin-treated mice showed attenuated ability to induce cSrc phosphorylation and the mRNA expression of the gene encoding for IL-8, suggesting long-lasting effects of curcumin on the virulence of H. pylori. Our work provides mechanistic evidence that encourages testing of curcumin as a dietary approach to inhibit the virulence of CagA.

scholarly journals Mutations of the Helicobacter pyloriGenes rdxA and pbp1 Cause Resistance against Metronidazole and Amoxicillin

2001 ◽  
Vol 45 (3) ◽  
pp. 962-965 ◽  
Author(s):  
Ralf Paul ◽  
Stefan Postius ◽  
Klaus Melchers ◽  
Klaus P. Schäfer
Keyword(s):  
Helicobacter Pylori ◽  
Resistance Genes ◽  
Resistant Strain ◽  
Parent Strain ◽  
Metronidazole Resistance ◽  
Pcr Products ◽  
Resistant Strains ◽  
H Pylori

ABSTRACT To investigate amoxicillin and metronidazole resistance ofHelicobacter pylori, we compared putative resistance genes between resistant strains obtained in vitro and their sensitive parent strain. All metronidazole-resistant strains hadrdxA mutations, and an amoxicillin-resistant strain hadpbp1 and pbp2 mutations. By transforming PCR products of these mutated genes into antibiotic-sensitive strains, we showed that rdxA null mutations were sufficient for metronidazole resistance, while pbp1mutations contributed to amoxicillin resistance of H. pylori.

scholarly journals Helicobacter pylori Activates the Early Growth Response 1 Protein in Gastric Epithelial Cells

2004 ◽  
Vol 72 (6) ◽  
pp. 3549-3560 ◽  
Author(s):  
M. M. M. Abdel-Latif ◽  
H. J. Windle ◽  
K. A. Fitzgerald ◽  
Y. S. Ang ◽  
D. Ní Eidhin ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Growth Response ◽  
Early Growth ◽  
Dependent Manner ◽  
Mobility Shift ◽  
Ags Cells ◽  
Early Growth Response ◽  
H Pylori ◽  
Early Growth Response 1

ABSTRACT The early growth response 1 (Egr-1) transcription factor is rapidly induced by various stimuli and is implicated in the regulation of cell growth, differentiation, and gene expression. The aim of this study was to examine the effect of Helicobacter pylori on the expression of Egr-1 and Egr-1-regulated genes in gastric epithelial AGS cells. Egr-1 expression was assayed by immunoblotting and electrophoretic mobility shift assays using H. pylori-stimulated AGS cells. Transient transfection experiments with promoter-reporter constructs of CD44, ICAM-1, and CD95L were used for expression studies. H. pylori induced the expression of Egr-1 in gastric epithelial cell lines in a dose-dependent manner, with the rapid kinetics that are typical of this class of transcription factors. Immunohistochemical studies of biopsies revealed that Egr-1 expression is more abundant in H. pylori-positive patients than in uninfected individuals. Reporter-promoter transfection studies indicated that Egr-1 binding is required for the H. pylori-induced transcriptional promoter activity of the CD44, ICAM-1, and CD95L (APO-1/Fas) constructs. The blocking of egr-1 with an antisense sequence prevented H. pylori-induced Egr-1 and CD44 protein expression. The MEK1/2 signaling cascade participates in H. pylori-mediated Egr-1 expression, but the p38 pathway does not. The data indicate that H. pylori induces Egr-1 expression in AGS cells in vitro and that the Egr-1 protein is readily detectable in biopsies from H. pylori-positive subjects. These observations suggest that H. pylori-associated Egr-1 expression may play a role, in part, in H. pylori-induced pathology.

scholarly journals Galectin-2 Has Bactericidal Effects against Helicobacter pylori in a β-galactoside-Dependent Manner

2020 ◽  
Vol 21 (8) ◽  
pp. 2697 ◽  
Author(s):  
Takaharu Sasaki ◽  
Rei Saito ◽  
Midori Oyama ◽  
Tomoharu Takeuchi ◽  
Toru Tanaka ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Bactericidal Effect ◽  
Dependent Manner ◽  
Peptic Ulcers ◽  
Gastric Tissue ◽  
Gastric Mucus ◽  
Biological Phenomena ◽  
Bactericidal Effects ◽  
H Pylori

Helicobacter pylori is associated with the onset of gastritis, peptic ulcers, and gastric cancer. Galectins are a family of β-galactoside-binding proteins involved in diverse biological phenomena. Galectin-2 (Gal-2), a member of the galectin family, is predominantly expressed in the gastrointestinal tract. Although some galectin family proteins are involved in immunoreaction, the role of Gal-2 against H. pylori infection remains unclear. In this study, the effects of Gal-2 on H. pylori morphology and survival were examined. Gal-2 induced H. pylori aggregation depending on β-galactoside and demonstrated a bactericidal effect. Immunohistochemical staining of the gastric tissue indicated that Gal-2 existed in the gastric mucus, as well as mucosa. These results suggested that Gal-2 plays a role in innate immunity against H. pylori infection in gastric mucus.

scholarly journals In Vitro Activities of Rabeprazole, a Novel Proton Pump Inhibitor, and Its Thioether Derivative Alone and in Combination with Other Antimicrobials against Recent Clinical Isolates ofHelicobacter pylori

2000 ◽  
Vol 44 (2) ◽  
pp. 458-461 ◽  
Author(s):  
Yoshiyuki Kawakami ◽  
Takayuki Akahane ◽  
Masaru Yamaguchi ◽  
Kozue Oana ◽  
Yuko Takahashi ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Proton Pump Inhibitor ◽  
Proton Pump ◽  
Synergistic Effects ◽  
Antagonistic Effect ◽  
Clinical Isolates ◽  
Rabeprazole Sodium ◽  
Kill Curve ◽  
Time Kill

ABSTRACT The MICs of rabeprazole sodium (RPZ), a newly developed benzimidazole proton pump inhibitor (PPI), against 133 clinicalHelicobacter pylori strains revealed a higher degree of activity than the another two PPIs, lansoprazole and omeprazole. Time-kill curve assays of RPZ, when combined with amoxicillin, clarithromycin, or metronidazole, disclosed that synergistic effects were demonstrated in combination with each antibiotic examined. Moreover, no apparent antagonistic effect appeared among all of the strains tested.

scholarly journals Comparison of the In Vitro Efficacies of Moxifloxacin and Amoxicillin against Listeria monocytogenes

2008 ◽  
Vol 52 (5) ◽  
pp. 1697-1702 ◽  
Author(s):  
S. Grayo ◽  
O. Join-Lambert ◽  
M. C. Desroches ◽  
A. Le Monnier
Keyword(s):  
Listeria Monocytogenes ◽  
Bactericidal Effect ◽  
Cross Resistance ◽  
Resistant Bacteria ◽  
Gram Positive Bacteria ◽  
Severe Infections ◽  
Potential Alternative ◽  
Kill Curve ◽  
Time Kill

ABSTRACT Listeria monocytogenes is a facultative intracellular bacterium that causes severe infections associated with a high mortality rate. Moxifloxacin presents extended activity against gram-positive bacteria and has recently been suggested to be a potential alternative in the treatment of listeriosis. We evaluated the in vitro efficacy of moxifloxacin against L. monocytogenes using a combination of epidemiological and experimental approaches. The median MIC of moxifloxacin for a large collection of L. monocytogenes strains of various origins (human, food, and environment) was 0.5 μg/ml (MIC range, 0.064 to 1 μg/ml). No differences were observed, irrespective of the origin of the strains. Moreover, no cross-resistance with fluoroquinolones was detected in strains that have been reported to be resistant to ciprofloxacin. The in vitro activities of moxifloxacin and amoxicillin were compared by time-kill curve and inhibition of intracellular growth experiments by using a model of bone marrow-derived mouse macrophages infected by L. monocytogenes EGDe. Both moxifloxacin and amoxicillin were bactericidal in broth against extracellular forms of L. monocytogenes. However, moxifloxacin acted much more rapidly, beginning to exert its effects in the first 3 h and achieving complete broth sterilization within 24 h of incubation. Moxifloxacin has a rapid bactericidal effect against intracellular reservoirs of bacteria, whereas amoxicillin is only bacteriostatic and appears to prevent cellular lysis and the subsequent bacterial spreading to adjacent cells. No resistant bacteria were selected during the in vitro experiments. Taken together, our results suggest that moxifloxacin is an interesting alternative to the reference treatment, combining rapid and bactericidal activity, even against intracellular bacteria.

scholarly journals The Antibacterial Activity of Mass Galla Chinesis et Camelliae Fermentata on Helicobacter pylori Infection

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Jing Yu ◽  
Hui Ye ◽  
Jiang Li ◽  
Ning Li ◽  
Zong-ming Shi ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Rapid Urease Test ◽  
Dosage Group ◽  
Urease Test ◽  
H Pylori ◽  
Time Kill

Mass Galla chinesis et camelliae Fermentata (Chinese gall leaven, CGL) was investigated for activities against Helicobacter pylori (H. pylori) both in vitro and in vivo. The agar dilution method and time-kill curves, as in vitro assays and an in vivo study using a Kunming mice model, were performed. CGL demonstrated a strong anti-Helicobacter pylori activity in vitro with the minimal inhibitory concentrations (MICs) against multiple H. pylori strains of 0.5~8 mg/ml and the decreasing trend time-kill curves when increasing CGL concentrations. H. pylori eradication rates in vivo were evaluated based on rapid urease test (RUT) and histopathologic criteria. Results revealed that the eradication rates in the CGL groups were 40% (4/10) in the high dosage group, 33% (4/11) in the medium dosage group, and 18% (2/11) in the low dosage group, with the difference between the high dosage and H. pylori control groups being significant (P=0.035). The H. pylori colonization scores could be reduced partly by CGL. These in vivo results demonstrated that CGL in a rationally high dosage might be the most effective.

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