scholarly journals Bifunctional enzyme SpoT is involved in biofilm formation of Helicobacter pylori with multidrug resistance by upregulating efflux pump Hp1174 (gluP)

2018 ◽  
Author(s):  
Xiaoran Ge ◽  
Yuying Cai ◽  
Zhenghong Chen ◽  
Sizhe Gao ◽  
Xiwen Geng ◽  
...  

ABSTRACTThe drug resistance of Helicobacter pylori (H. pylori) is gradually becoming a serious problem. Biofilm formation is an important factor that leads to multidrug resistance in bacteria. The ability of H. pylori to form biofilms on the gastric mucosa has been known. However, there are few studies on the regulation mechanisms of H. pylori biofilm formation and multidrug resistance. Guanosine 3’-diphosphate 5’-triphosphate and guanosine 3’,5’-bispyrophosphate [(p)ppGpp] are global regulatory factors and are synthesized in H. pylori by the bifunctional enzyme SpoT. It has been reported that (p)ppGpp is involved in the biofilm formation and multidrug resistance of various bacteria. In this study, we found that SpoT also plays an important role in H. pylori biofilm formation and multidrug resistance. Therefore, it is necessary to carry out some further studies regarding its regulatory mechanism. Considering that efflux pumps are of great importance in the biofilm formation and multidrug resistance of bacteria, we tried to find if efflux pumps controlled by SpoT participate in these activities. Then, we found that Hp1174 (glucose/galactose transporter, gluP), an efflux pump of the MFS family, is highly expressed in biofilm-forming and multi-drug resistance (MDR) H. pylori and is upregulated by SpoT. Through further research, we determined that gluP involved in H. pylori biofilm formation and multidrug resistance. Furthermore, the average expression level of gluP in clinical MDR strains was considerably higher than that in clinical drug-sensitive strains. Taken together, our results revealed a novel molecular mechanism of H. pylori tolerance to multidrug.

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Xiaoran Ge ◽  
Yuying Cai ◽  
Zhenghong Chen ◽  
Sizhe Gao ◽  
Xiwen Geng ◽  
...  

ABSTRACTThe drug resistance ofHelicobacter pyloriis gradually becoming a serious problem. Biofilm formation is an important factor that leads to multidrug resistance (MDR) in bacteria. The ability ofH. pylorito form biofilms on the gastric mucosa is known. However, there are few studies on the regulatory mechanisms ofH. pyloribiofilm formation and multidrug resistance. Guanosine 3′-diphosphate 5′-triphosphate and guanosine 3′,5′-bispyrophosphate [(p)ppGpp] are global regulatory factors and are synthesized inH. pyloriby the bifunctional enzyme SpoT. It has been reported that (p)ppGpp is involved in the biofilm formation and multidrug resistance of various bacteria. In this study, we found that SpoT also plays an important role inH. pyloribiofilm formation and multidrug resistance. Therefore, it was necessary to carry out some further studies regarding its regulatory mechanism. Considering that efflux pumps are of great importance in the biofilm formation and multidrug resistance of bacteria, we tried to determine whether efflux pumps controlled by SpoT participate in these activities. We found that Hp1174 (glucose/galactose transporter [gluP]), an efflux pump of the major facilitator superfamily (MFS), is highly expressed in biofilm-forming and multidrug-resistant (MDR)H. pyloristrains and is upregulated by SpoT. Through further research, we determined thatgluPis involved inH. pyloribiofilm formation and multidrug resistance. Furthermore, the average expression level ofgluPin the clinical MDR strains (C-MDR) was considerably higher than that in the clinical drug-sensitive strains (C-DSS). Taken together, our results revealed a novel molecular mechanism ofH. pyloriresistance to multidrug exposure.


Author(s):  
Yican Zhao ◽  
Yuying Cai ◽  
Zhenghong Chen ◽  
Huanjie Li ◽  
Zhengzheng Xu ◽  
...  

Recently, there is increased incidence of drug-resistant Helicobacter pylori infection. Biofilm formation confers multidrug resistance to bacteria. Moreover, it has been found that the formation of biofilm on the surface of gastric mucosa is an important reason for the difficulty of eradication of H. pylori. The mechanisms underlying H. pylori biofilm formation in vivo have not been elucidated. Reactive oxygen species (ROS) released by the host immune cells in response to H. pylori infection cannot effectively clear the pathogen. Moreover, the extracellular matrix of the biofilm protects the bacteria against ROS-mediated toxicity. This study hypothesized that ROS can promote H. pylori biofilm formation and treatment with low concentrations of hydrogen peroxide (H2O2) promoted this process in vitro. The comparative transcriptome analysis of planktonic and biofilm-forming cells revealed that the expression of SpoT, a (p)ppGpp (guanosine 3'-diphosphate 5'-triphosphate and guanosine 3',5'-bispyrophosphate) synthetase/hydrolase, is upregulated in H2O2-induced biofilms and that knockout of spoT inhibited H. pylori biofilm formation. Additionally, this study examined the key target molecules involved in SpoT regulation using weighted gene co-expression network analysis. The analysis revealed that neutrophil-activating protein (NapA; HP0243) promoted H2O2-induced biofilm formation and conferred multidrug resistance. Furthermore, vitamin C exhibited anti-H. pylori biofilm activity and downregulated the expression of napA in vitro. These findings provide novel insight into the clearance of H. pylori biofilms.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 863
Author(s):  
Viola Camilla Scoffone ◽  
Gabriele Trespidi ◽  
Giulia Barbieri ◽  
Samuele Irudal ◽  
Elena Perrin ◽  
...  

Drug resistance represents a great concern among people with cystic fibrosis (CF), due to the recurrent and prolonged antibiotic therapy they should often undergo. Among Multi Drug Resistance (MDR) determinants, Resistance-Nodulation-cell Division (RND) efflux pumps have been reported as the main contributors, due to their ability to extrude a wide variety of molecules out of the bacterial cell. In this review, we summarize the principal RND efflux pump families described in CF pathogens, focusing on the main Gram-negative bacterial species (Pseudomonas aeruginosa, Burkholderia cenocepacia, Achromobacter xylosoxidans, Stenotrophomonas maltophilia) for which a predominant role of RND pumps has been associated to MDR phenotypes.


Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1062
Author(s):  
Paweł Krzyżek ◽  
Rossella Grande ◽  
Paweł Migdał ◽  
Emil Paluch ◽  
Grażyna Gościniak

Helicobacter pylori is a bacterium that is capable of colonizing a host for many years, often for a lifetime. The survival in the gastric environment is enabled by the production of numerous virulence factors conditioning adhesion to the mucosa surface, acquisition of nutrients, and neutralization of the immune system activity. It is increasingly recognized, however, that the adaptive mechanisms of H. pylori in the stomach may also be linked to the ability of this pathogen to form biofilms. Initially, biofilms produced by H. pylori were strongly associated by scientists with water distribution systems and considered as a survival mechanism outside the host and a source of fecal-oral infections. In the course of the last 20 years, however, this trend has changed and now the most attention is focused on the biomedical aspect of this structure and its potential contribution to the therapeutic difficulties of H. pylori. Taking into account this fact, the aim of the current review is to discuss the phenomenon of H. pylori biofilm formation and present this mechanism as a resultant of the virulence and adaptive responses of H. pylori, including morphological transformation, membrane vesicles secretion, matrix production, efflux pump activity, and intermicrobial communication. These mechanisms will be considered in the context of transcriptomic and proteomic changes in H. pylori biofilms and their modulating effect on the development of this complex structure.


2020 ◽  
Vol 25 (44) ◽  
pp. 4717-4724
Author(s):  
Xiao-Ling Xu ◽  
Xu-Qi Kang ◽  
Jing Qi ◽  
Fei-Yang Jin ◽  
Di Liu ◽  
...  

Background: Antibacterial multidrug resistance has emerged as one of the foremost global problems affecting human health. The emergence of resistant infections with the increasing number of multidrug-resistant pathogens has posed a serious problem, which required innovative collaborations across multiple disciplines to address this issue. Methods: In this review, we will explain the mechanisms of bacterial multidrug resistance and discuss different strategies for combating it, including combination therapy, the use of novel natural antibiotics, and the use of nanotechnology in the development of efflux pump inhibitors. Results: While combination therapy will remain the mainstay of bacterial multi-drug resistance treatment, nanotechnology will play critical roles in the development of novel treatments in the coming years. Conclusion: Nanotechnology provides an encouraging platform for the development of clinically relevant and practical strategies to overcome drug resistance in the future.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Laure Brigitte Kouitcheu Mabeku ◽  
Bertrand Eyoum Bille ◽  
Cromwell Tepap Zemnou ◽  
Lionel Danny Tali Nguefack ◽  
Hubert Leundji

Abstract Background Antibiotic resistance is a leading cause of treatment failure in Helicobacter pylori infection. In Africa, there are very little data concerning the susceptibility of Helicobacter pylori isolates to antibiotics. The purpose of this study was to evaluate the resistance prevalence of Helicobacter pylori strains circulating in Cameroon, and to assess overexpression of efflux pump as a possible multi-drug resistance mechanisms. Methods A total of 140 H. pylori isolates were recovered from gastric biopsies of dyspeptic patients in two reference hospitals in Cameroon and analyzed for their antimicrobial susceptibility to amoxicillin, co-amoxiclav, ampicillin, penicillin, imipenem, metronidazole, rifabutin, erythromycin, clarithromycin, azithromycin, levofloxacin, ciprofloxacin, norfloxacin, tetracycline, doxycycline and minocycline. Antibiotic sensitivity was tested by disk diffusion method. Phe-Arg-naphthylamide (PAßN) was used as efflux pump inhibitor. INT broth microdilution method in supplemented Brain Heart Infusion broth was used to determine the MIC of ampicillin, amoxicillin, metronidazole, erythromycin, clarithromycin and doxycycline in the absence and the presence of PAßN against 32 selected MDR isolates. Results Overall H. pylori resistance rate was 100% to ampicillin, penicillin and co-amoxiclav; 97.14% to amoxicillin, 97.85% to metronidazole, 47.85% to erythromycin, 13.57% to clarithromycin; 5, 2.86 and 0.71% to doxycycline, tetracycline and minocycline respectively. No resistance to azithromycin, rifabutin, imipenem, ciprofloxacin, norfloxacin and levofloxacin was detected among H. pylori isolates. Seventy percent (70%) of the tested isolates elicited a multiple drugs resistance pattern; 42.57% double, 15.71% triple and 5.71% quadruple drugs resistance. Metronidazole and amoxicillin were more concerned with double resistance pattern (86.76%). The spectrum of activity recorded with metronidazole, doxycycline, clarithromycin and erythromycin ranged from 0 to 100% in the absence to the presence of PAßN against the tested MDR isolates. An 8 to 128-fold increase in potency was also noticed with these antibiotics in the presence of PAßN. Conclusion With regard to the high resistance rate to both amoxicillin and metronidazole, these drugs should be avoided as components of triple therapy in our milieu. In contrast, ciprofloxacin, norfloxacin, levofloxacin and tetracyclines could be used to achieve a better eradication rate and to reduce the risk of selection of H. pylori resistant strains.


2021 ◽  
pp. 15-23

Introduction: The aim of the study was the analysis of occurrence of genetic determinants of multi-drug resistance and the assessment of genetic relationship among Acinetobacter baumannii strains. Methods: Multiplex-PCR method was performed in order to: (1) confirm the phenotypic identification and (2) detect the presence of CHDL oxacillinases in the group of thirty A.baumannii strains. Further PCR studies included the analysis of the occurrence of genetic determinants associated with efflux pump, insertion sequence and biofilm formation. The relationship between bacterial strains was assayed using 6 primers in RAPD-PCR method. Results: Detection of the blaOXA-51-like gene confirmed that the strains belong to the A. baumannii species. In the multiplex-PCR, the presence of the blaOXA-23-like and blaOXA-40-like genes was detected in 3 (10%) and 27 (90%) isolates, respectively. Moreover, some strains showed the coexistence of the blaOXA-51-like and blaOXA-23-like genes (10%, n=3) or blaOXA-51-like and blaOXA-40-like (90%, n=27). In the group of analysed strains the presence of the efflux pump gene (adeA) and the insertion sequence ISAba1 were demonstrated in all tested isolates. Biofilm-related genes (abaI, csuE) were found in 100% and 97% (n=29) tested strains adequately. The RAPD-PCR studies revealed the presence of 10 unrelated genotypes. Conclusions: The obtained results suggest that the phenomenon of multi-drug resistance in the studied A. baumannii strains could be attributed to the occurrence of CHDL oxacillinases, AdeABC efflux pump, insertion sequence ISAba1 and the biofilm formation.


2019 ◽  
Vol 19 (5) ◽  
pp. 376-382 ◽  
Author(s):  
Sachin Jangra ◽  
Gayathri Purushothaman ◽  
Kapil Juvale ◽  
Srimadhavi Ravi ◽  
Aishwarya Menon ◽  
...  

Background & Objective:Helicobacter pylori infection is one of the primary causes of peptic ulcer followed by gastric cancer in the world population. Due to increased occurrences of multi-drug resistance to the currently available antibiotics, there is an urgent need for a new class of drugs against H. pylori. Inosine 5′-monophosphate dehydrogenase (IMPDH), a metabolic enzyme plays a significant role in cell proliferation and cell growth. It catalyses guanine nucleotide synthesis. IMPDH enzyme has been exploited as a target for antiviral, anticancer and immunosuppressive drugs. Recently, bacterial IMPDH has been studied as a potential target for treating bacterial infections. Differences in the structural and kinetic parameters of the eukaryotic and prokaryotic IMPDH make it possible to target bacterial enzyme selectively.Methods:In the current work, we have synthesised and studied the effect of substituted 3-aryldiazenyl indoles on Helicobacter pylori IMPDH (HpIMPDH) activity. The synthesised molecules were examined for their inhibitory potential against recombinant HpIMPDH.Results:In this study, compounds 1 and 2 were found to be the most potent inhibitors amongst the database with IC50 of 0.8 ± 0.02µM and 1 ± 0.03 µM, respectively.Conclusion:When compared to the most potent known HpIMPDH inhibitor molecule C91, 1 was only four-fold less potent and can be a good lead for further development of selective and potent inhibitors of HpIMPDH.


2021 ◽  
Vol 22 (5) ◽  
pp. 2695
Author(s):  
Paweł Krzyżek ◽  
Paweł Migdał ◽  
Emil Paluch ◽  
Magdalena Karwańska ◽  
Alina Wieliczko ◽  
...  

Helicobacter pylori, a gastric pathogen associated with a broad range of stomach diseases, has a high tendency to become resistant to antibiotics. One of the most important factors related to therapeutic failures is its ability to change from a spiral to a coccoid form. Therefore, the main aim of our original article was to determine the influence of myricetin, a natural compound with an antivirulence action, on the morphological transformation of H. pylori and check the potential of myricetin to increase the activity of antibiotics against this pathogen. We observed that sub-minimal inhibitory concentrations (sub-MICs) of this compound have the ability to slow down the process of transformation into coccoid forms and reduce biofilm formation of this bacterium. Using checkerboard assays, we noticed that the exposure of H. pylori to sub-MICs of myricetin enabled a 4–16-fold reduction in MICs of all classically used antibiotics (amoxicillin, clarithromycin, tetracycline, metronidazole, and levofloxacin). Additionally, RT-qPCR studies of genes related to the H. pylori morphogenesis showed a decrease in their expression during exposure to myricetin. This inhibitory effect was more strongly seen for genes involved in the muropeptide monomers shortening (csd3, csd6, csd4, and amiA), suggesting their significant participation in the spiral-to-coccoid transition. To our knowledge, this is the first research showing the ability of any compound to synergistically interact with all five antibiotics against H. pylori and the first one showing the capacity of a natural substance to interfere with the morphological transition of H. pylori from spiral to coccoid forms.


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