Prevalence of heteroresistant Helicobacter pylori and treatment follow-up in patients in Ilam, Iran.

Background: Special antibiotics are prescribed against Helicobacter (H.) pylori. However, sometimes the bacteria are not completely eliminated, or they are recurrent. Unlike most infections, it is very difficult to eliminate a H. pylori infection. Heteroresistance is defined as the phenomenon in which subpopulations of the same colony of bacteria exhibit a range of susceptibilities to a particular antibiotic. Because of heteroresistant cells, antibiotic failure and chronic infection can occur; thus, the current research aimed to investigate presence of heteroresistant cells in H. pylori collected from patients reffering to clinic in Ilam, Iran. Subsequently, patients who were infected with heteroresistant H. p ylori were treated with antibiotics effective against heteroresistant subpopulations. Methods: In this cross-sectional descriptive study, 100 patients with clinical symptoms and suspected of being infected with H. pylori were studied in private clinics in Ilam, Iran. Fiftyisolates of H. pylori accompanied by patients' information were obtained from Ilam clinics. We cultured the bacteria to identify heteroresistance and to find the cause of recurrent infection in these patients. Results: Out of a total of 50 samples, 3 were heteroresistant to clarithromycin (6%). Levofloxacin was applied in cases of heteroresistant samples, and the effectiveness was determined after one month of follow-up of patients. Conclusion: Patients with heteroresistance showed sensitivity to levofloxacin. After one month of follow-up, it was found that the effectiveness of this antibiotic was good. Therefore, this antibiotic was introduced as a more effective drug in patients with heteroresistant H. pylori.

In vitro anti-biofilm properties of the peel of fruite wall of acorn against Streptococcus mutans.

Dental caries is a multi-factorial infectious disease. The primary cause is dental plaque, a complex of biofilm. It was postulated that the ethanolic extract of fruite wall of acorn may represent a new substance to prevent caries. Hence, the study was performed to evaluate the effect of ethanolic extract of fruite wall of acorn against biofilm formation by Streptococcus mutans, which is associated with dental plaque. The cytotoxicity of the ethanolic extract was determined against Vero cells resulting in an inhibitory concentration of 50 (IC50) of 55 µg/ml. After bacterial collection, different concentrations under the IC50 from the extract were evaluated against biofilm formation of S. mutans. 3 µg/ml of the extract inhibited the biofilm formation of S. mutans, and 1 to 3 µg/ml caused a decrease in gtfB and brpA biofilm-production genes. This study showed the potency of the ethanolic extract of fruite wall of acorn against biofilm formation by S. mutans.

In Vitro and In Silico Investigation of some Type II TA Genes in H. Pylori.

BACKGROUND: In addition to antibiotic resistance, the entry of Helicobacter pylori into the persistence phase leads to recurrent and chronic infections, as well as the development of antibiotic resistance in persister cells. METHODS: In this study, after genetic confirmation of H. pylori in 20 biopsy specimens, the prevalence of the type II TA systems mazEF, relEB, yafQ/dinJ was investigated. Also, the most common system observed in the study in terms of structure, evolution, and molecular interaction was evaluated by bioinformatics tools. RESULTS: The results of the PCR test on 20 biopsy samples were positive for ureA and glmM genes. Moreover, yafQ/ dinJ was the only module positive in half of the samples (10 samples) in the PCR technique. The toxin residues and their interactions with the cognate antitoxin residues are revealed by docking analysis results. Furthermore, the multiple sequence alignment (MSA) of the YafQ toxin showed that this toxin has a low polymorphism among H. pylori species. The evolutionary study showed that the yafQ toxin had the highest sequence similarity among the bacteria Helicobacter cetorm (60% similarity) and Muricauda olearia (57.35 % similarity). CONCLUSIONS: Collectively, the data of the present study indicate that the YafQ/DinJ is the dominant type II TA system and has the highest frequency among the studied systems in H. pylori, and further studies are required to elucidate its exact role in this bacterium.

In vitro Eradication of Pseudomonas aeruginosa Persister Cell Producers by Peganum harmala.

BACKGROUND: Because of increasing antibiotic failure and recurrence of infections in patients with P. aeruginosa, the present study was designed to determine the antibiotic resistance status, presence of persister cells and investigate the antipersister effect of Peganum harmala in P. aeruginosa clinical isolates in vitro in Ilam, Iran. METHODS: Thirty P. aeruginosa urinary clinical isolates were collected from hospitals in Ilam, Iran and identified by common microbiological and biochemical tests. Afterward, antibiotic susceptibility assay, persister cell assay, P. harmala extraction, cell culture, and cell viability assays were performed. RESULTS: A high rate of antibiotic resistance was observed. All isolates were resistant to co-amoxiclav. Also, 83.3% (n = 25), 90% (n = 27), and 36.6% (n = 11) of isolates showed resistance to ceftazidime, kanamycin, and tobramycin, respectively. The MIC and MBC values for imipenem were ≤ 2 and 2 µg/mL for susceptible isolates, respectively. In addition, 6.66% (n = 2) of isolates were persister cells and were also sensitive to imipenem by MIC but did not show any MBC. IC50 for P. harmala was 35 µg/mL. Eventually, MIC value of P. harmala against two P. aeruginosa persister cell producer isolates was 3 µg/mL and 1 µg/mL, and the value of MBC was 10 µg/mL and 30 µl/mL. CONCLUSIONS: Our findings demonstrated that P. harmala may be a suitable antipersister herbal medicine against P. aeruginosa clinical isolates. In this regard, comprehensive research is needed in the future to gain more information in this area.

Persister cells as a possible cause of antibiotic therapy failure in Helicobacter pylori.

BACKGROUND AND AIM: Due to the failure of antibiotic treatment and recurrence of infection in patients with Helicobacter pylori, this study was designed to find the possible cause of treatment failure and recurrence of the H. pylori infections in Ilam, Iran. METHODS: One hundred patients with specific symptoms of H. pylori infection were selected, and after taking a biopsy specimen, identification of H. pylori, antibiotic susceptibility assay, and persister cell assay were performed. In addition, after treatment, patients with persister cells were followed for possible recurrence of infection. Furthermore, an antibiotic susceptibility assay was performed. RESULTS: Our results demonstrated that, among 100 patients, 50% (n = 50) showed positive results for the existence of H. pylori. Among the susceptible isolates, 18% (n = 9) were persister cells that were sensitive to clarithromycin as confirmed by a 5 folds higher than the Minimal Inhibitory Concentration (MIC) of clarithromycin. The data were confirmed by following up the suspected patients. CONCLUSION: Our results demonstrated that persister cells in H. pylori infections may be responsible to recurrent infection and antibiotic treatment failure. However, more research is needed to obtain more information in this area.

In vivo Antibacterial and Wound Healing Activities of Roman Chamomile (Chamaemelum nobile).

BACKGROUND: Today considerable number of drugs are produced from plants. Several plants with antibacterial and healing applications are used in medicine such as Roman chamomile (Chamaemelum nobile L.). Wound infection is one of the most prevalent infections among infectious diseases around the world. Due to appearance of drug resistance, researchers are now paying attention to medicinal plants. Therefore, this study was designed to investigate the antimicrobial and wound healing properties of C. nobile against Pseudomonas aeruginosa using in vivo conditions. METHODS: Ethanolic extract of C. nobile was provided using standard method. The 5% C. nobile ointment was prepared by dissolving lyophilized extract in eucerin. Forty five male rats were obtained from Ilam university. After anesthetization and wound creation, wounds were infected by P. aeruginosa. The rats were divided into three groups, group I was treated with C. nobile ointment, group II was treated with tetracycline ointment and the third group was treated with base gel as control group. RESULTS: Antibacterial and wound healing activities of C. nobile ointment were more than tetracycline ointment significantly. Our results indicated that extract of C. nobile had effective antibacterial activity and accelerated the progression of wound healing. CONCLUSION: Our study indicated that antibacterial and wound healing activities of C. nobile ointment were notable. C. nobile therapy in combination with antibiotics can also be useful because medicinal plants contents operate in synergy with antibiotics. These results revealed the value of plant extracts to control antibiotic resistant bacteria in wound infections.

mazE Antitoxin of Toxin Antitoxin System and fbpA as Reliable Targets to Eradication of Neisseria meningitidis.

BACKGROUND: Neisseria meningitidis is considered as a dangerous pathogen threatening human health. Nowadays, the new drug target is focused. Toxin antitoxin (TA) system is recently identified as an antimicrobial drug target. Also, in N. meningitidis, iron-uptake system could be an interesting target for drug discovery. METHODS: In this study, fbpA and mazE genes were chosen as new antimicrobial targets and treated with antisense peptide nucleic acid (PNA). Firstly, they were evaluated by bioinformatics and then analyzed by experimental procedures. Secondly, the functionality was evaluated by stress conditions. RESULTS: Our results interestingly demonstrated that when fbpA and mazE loci of N. meningitidis were targeted by antisense PNA, 8 µM concentration of fbpA-PNA as well as 30 µM concentration of mazE-PNA inhibited the growth of N. meningitides and were found to be bacteriostatic, whereas 10 µM concentration of fbpA-PNA showed bacteriocidal activity. CONCLUSION: Our findings demonstrated the bactriocidal activity of fbpA-PNA and bacteriostatic activity of mazEPNA. Therefore, mazE and fbpA genes should be potent antimicrobial targets but further analysis including in vivo analysis should be performed.

Novel Information about Neisseria meningitidis: Identification of the Most Important Type II Toxin Antitoxin Systems.

BACKGROUND: Toxin antitoxin systems is the one of the important elements among pathogenic bacteria which have proven roles such as biofilm formation, cell programmed death and persister cells formation. Neisseria meningitidis causing serious diseases in humans must be highlighted. OBJECTIVE: The current study aimed to identify the mazEF and relBE TA systems in N. meningitidis. METHOD: The potential TA loci were searched in RASTA database by bioinformatics analysis and then, experimental analysis was performed by PCR assay. PCR products were confirmed by sequencing. RESULTS: Our findings demonstrated that mazEF and relBE TA systems were positive by PCR assay and results of sequencing confirmed the PCR results. CONCLUSION: Notably, our highlighted findings are the first report of mazEF and RelBE TA loci in N. meningitides. Finally, we strongly recommended that laboratory experiments should be performed to identify the roles of these TA loci in N. meningitides.

Anti-biofilm Properties of Peganum harmala against Candida albicans.

OBJECTIVES: Vaginitis still remains as a health issue in women. It is notable that Candida albicans producing biofilm is considered a microorganism responsible for vaginitis with hard to treat. Also, Peganum harmala was applied as an anti fungal in treatment for many infections in Iran. Therefore, this study goal to investigate the role of P. harmala in inhibition of biofilm formation in C. albicans. METHODS: So, 27 C. albicans collected from women with Vaginitis, then subjected for biofilm formation assay. P. harmala was applied as antibiofilm formation in C. albicans. RESULTS: Our results demonstrated that P. harmala in concentration of 12 µg/ml easily inhibited strong biofilm formation; while the concentrations of 10 and 6 µg/ml inhibited biofilm formation in moderate and weak biofilm formation C. albicans strains, respectively. CONCLUSION: Hence, the current study presented P. harmala as antibiofilm herbal medicine for C. albicans; but in vivo study suggested to be performed to confirm its effectiveness.