Clostridioides Difficile: A Concise Review of Best Practices and Updates.

Clostridioides difficile infection (CDI) is one of the most common and severe nosocomial infections worldwide. It can also affect healthy individuals in the community. The incidence of CDI has been on the rise globally for the past decade, necessitating a proactive approach to combat its spread; new strategies are being developed to enhance diagnostic accuracy and optimize treatment outcomes. Implementing the 2-step testing has increased diagnostic specificity, reducing the usage of CD-specific antibiotics with no concomitant increase in surgical complication rates. In 2021, the Infectious Diseases Society of America/Society for Healthcare Epidemiology of America (IDSA/SHEA) shifted its preference for initial treatment to fidaxomicin over vancomycin and metronidazole due to its lower recurrence rate. It also prioritized fidaxomicin for the treatment of recurrent CDI. There are new developments on the frontiers of fecal microbiota therapies, with RBX2660 and SER-109 approved recently by the FDA for prevention, with other microbiome-based therapies in various development and clinical trials. This review offers providers an updated and practical guide for CDI management.

Metronidazole-Induced Encephalopathy With Probable Crohn Encephalitis: A Case Report.

OBJECTIVES: Metronidazole central nervous system toxicity is a rare finding in patients receiving the medication. We report a peculiar case of metronidazole central nervous system toxicity in which both the underlying condition (Crohn disease) and the drugs used to treat it are potential causes of encephalopathy. METHODS: A 26-year-old female with 6-year history of Crohn's disease for 6 years presented acute-onset encephalopathy. We provide bibliographic evidence to support metronidazole toxicity and potential Crohn disease-associated neurologic involvement. RESULTS: The patient presented dystonia, cerebellar ataxia, and altered mental status. Magnetic resonance imaging of the brain revealed typical findings of metronidazole toxicity and white matter involvement of the centrum semiovale. Immunoelectrophoresis and immunofixation of serum and cerebrospinal fluid proteins were consistent with a systemic inflammatory process. We concluded on an association between drug toxicity and probable Crohn-associated neurologic involvement. Metronidazole was stopped and the patient was placed on vitamin therapy and diazepam to control dystonia. She deteriorated and was transferred to the intensive care unit where she expired. CONCLUSIONS: Acute behavioral changes in a young patient constitute an emergency and differential diagnoses should include infective, inflammatory, metabolic, and toxic causes. Metronidazole is a potential toxic etiology.

Response to Antibiotic Treatment of Bacterial Vaginosis Predicts the Effectiveness of LACTIN-V (Lactobacillus crispatus CTV-05) in the Prevention of Recurrent Disease.

OBJECTIVES: Live biotherapeutic products (LBPs) containing vaginal Lactobacillus crispatus are promising adjuvant treatments to prevent recurrent bacterial vaginosis (BV) but may depend on the success of initial antibiotic treatment. METHODS: A post hoc analysis of data collected during the phase 2b LACTIN-V randomized control trial (L. crispatus CTV-05) explored the impact of clinical BV cure defined as Amsel criteria 0 of 3 (excluding pH, per 2019 Food and Drug Administration guidance) 2 days after completion of treatment with vaginal metronidazole gel on the effectiveness of an 11-week LACTIN-V dosing regimen to prevent BV recurrence by 12 and 24 weeks. RESULTS: At enrollment, 88% of participants had achieved postantibiotic clinical BV cure. The effect of LACTIN-V on BV recurrence compared with placebo differed by initial clinical BV cure status. The LACTIN-V to placebo risk ratio of BV recurrence by 12 weeks was 0.56 (95% confidence interval, 0.35-0.77) among participants with initial clinical BV cure after metronidazole treatment and 1.34 (95% confidence interval, 0.47-2.23) among participants without postantibiotic clinical BV cure. Among women receiving LACTIN-V, those who had achieved postantibiotic clinical BV cure at enrollment reached higher levels of detectable L. crispatus CTV-05 compared with women failing to achieve postantibiotic clinical BV cure. CONCLUSIONS: LACTIN-V seems to only decrease BV recurrence in women with clinical cure of BV after initial antibiotic treatment. Future trials of LBPs should consider limiting enrollment to these women.

Efficacy of Dequalinium Chloride vs Metronidazole for the Treatment of Bacterial Vaginosis: A Randomized Clinical Trial.

Importance: Bacterial vaginosis (BV) is a common cause of vaginal infection. First-line treatments of BV are metronidazole and clindamycin. Due to the increase in antibiotic resistance, effective nonantibiotic treatments for BV are needed. Objective: To examine whether dequalinium chloride, a broad-spectrum antiseptic, is noninferior to oral metronidazole for the treatment of BV. Design, Setting, and Participants: This phase 4, multicenter, triple-blind, double-dummy, parallel, noninferiority randomized clinical trial was conducted from July 29, 2021, to August 25, 2022, with a 1-month follow-up. Participants were premenopausal women 18 years or older with BV from 11 gynecologic practices and 1 hospital in Poland, Slovakia, and the Czech. Intervention: Patients were randomized to treatment with dequalinium chloride vaginal tablets (10 mg once daily for 6 days) or oral metronidazole (500 mg twice daily for 7 days). Double-dummy medication kits contained vaginal and oral tablets with placebo and active medication. Main Outcomes and Measures: The main outcome was the noninferiority margin (of 15 percentage points) in the absolute difference in clinical cure rates between dequalinium chloride and metronidazole 7 to 11 days after start of treatment (visit 1). Noninferiority was met if the lower 95% CI for the difference in clinical cure rate was less than 15 percentage points at visit 1. Results: A total of 147 women (mean [SD] age, 36.7 [9.0] years) were treated with dequalinium chloride (n = 72) or metronidazole (n = 75). The clinical cure rates at visit 1 were 64 of 69 (92.8%) for dequalinium chloride vs 69 of 74 (93.2%) for metronidazole in the intention-to-treat population, whereas in the per-protocol population, cure rates were 54 of 58 (93.1%) for dequalinium chloride vs 48 of 53 (90.6%) for metronidazole. The treatment differences of -0.5 percentage points (95% CI, -10.8 to 9.8 percentage points; P = .002) in the intention-to-treat population and 2.5 percentage points (95% CI, -9.4 to 14.4 percentage points; P = .001) in the per-protocol population confirmed the noninferiority of dequalinium chloride. The tolerability of dequalinium chloride was rated as very good by 30 of 50 patients (60.0%) but only by 21 of 54 (38.9%) for metronidazole. Three patients in the metronidazole group suspended treatment due to an adverse event. Conclusions and Relevance: This randomized clinical trial showed that dequalinium chloride was not inferior to metronidazole for the treatment of BV. Dequalinium chloride had a similarly high cure rate but with better tolerability and fewer adverse events. With a similar efficacy to metronidazole and clindamycin, dequalinium chloride warrants consideration as first-line treatment for BV to help reduce antibiotic consumption. Trial Registration: EudraCT: 2020-002489-15.

One-pot synthesis of NiCo-phyllosilicate supported on zeolite for enhanced degradation of antibiotic contaminants.

The overuse of antibiotics currently results in the presence of various antibiotics being detected in water bodies, which poses potential risks to human health and the environment. Therefore, it is highly significant to remove antibiotics from water. In this study, we developed novel rod-like NiCo-phyllosilicate hybrid catalysts on calcined natural zeolite (NiCo@C-zeolite) via a facile one-pot process. The presence of the zeolite served as both a silicon source and a support, maintaining a high specific surface area of the NiCo@C-zeolite. Remarkably, NiCo@C-zeolite exhibited outstanding catalytic performance in antibiotic degradation under PMS activation. Within just 5 min, the degradation rate of metronidazole (MNZ) reached 96.14%, ultimately achieving a final degradation rate of 99.28%. Furthermore, we investigated the influence of catalyst dosage, PMS dosage, MNZ concentration, initial pH value, and various inorganic anions on the degradation efficiency of MNZ. The results demonstrated that NiCo@C-zeolite displayed outstanding efficacy in degrading MNZ under diverse conditions and maintained a degradation rate of 94.86% at 60 min after three consecutive cycles of degradation. Free radical quenching experiments revealed that SO•-4played a significant role in the presence of NiCo@C-zeolite-PMS system. These findings indicate that the novel rod-like NiCo-phyllosilicate hybrid catalysts had excellent performance in antibiotic degradation.

Understanding the pivotal role of ubiquitous Yellow River suspend sediment in efficiently degrading metronidazole pollutants in water environments.

Sulfite-based advanced oxidation technology has received considerable attention for its application in organic pollutants elimination. However, the potential of natural sediments as effective catalysts for sulfite activation has been overlooked. This study investigates a novel process utilizing suspended sediment/sulfite (SS/S(IV)) for degradation of metronidazole (MNZ). Our results demonstrate that MNZ degradation efficiency can reach to 93.1 % within 90 min with 12.0 g SS and 2.0 mM sulfite. The influencing environmental factors, including initial pH, SS dosage, S(IV) concentration, temperature, and co-existing substances were systematically investigated. Quenching experiments and electron paramagnetic resonance analyses results indicate that SO3•- is the primary active substance responsible for MNZ degradation, with involvement of SO4•-, SO5•-, and •OH. X-ray photoelectron spectroscopy and Mössbauer spectra reveal that Fe (III)-silicates play a crucial role in activating S(IV). Furthermore, analysis of degradation intermediates and pathways of MNZ is conducted using liquid chromatography with mass spectrometry (LC -MS). The toxicity of MNZ and its intermediates were also systematically evaluated by the T.E.ST. program and wheat seeds germination test. This study offers valuable insight into the activation of sulfite by natural sediments and could contribute to the development of SS-based advanced oxidation processes (AOPs) for the in-situ remediation of antibiotics-contaminated water environments.

Fourteen-day vonoprazan-based bismuth quadruple therapy for H. pylori eradication in an area with high clarithromycin and levofloxacin resistance: a prospective randomized study (VQ-HP trial).

Potassium-competitive acid blockers (P-CABs) provide potent acid inhibition, yet studies on P-CAB-based quadruple therapy for H. pylori eradication are limited. We theorized that integrating bismuth subsalicylate into a quadruple therapy regimen could enhance eradication rates. However, data on the efficacy of vonoprazan bismuth quadruple therapy are notably scarce. Therefore, the aim of this study was to evaluate the efficacy of vonoprazan-based bismuth quadruple therapy in areas with high clarithromycin and levofloxacin resistance. This was a prospective, single-center, randomized trial conducted to compare the efficacy of 7-day and 14-day vonoprazan-based bismuth quadruple therapy for H. pylori eradication between June 1, 2021, and March 31, 2022. Qualified patients were randomly assigned to the 7-day or 14-day regimen (1:1 ratio by computer-generated randomized list as follows: 51 patients for the 7-day regimen and 50 patients for the 14-day regimen). The regimens consisted of vonoprazan (20 mg) twice daily, bismuth subsalicylate (1024 mg) twice daily, metronidazole (400 mg) three times daily, and tetracycline (500 mg) four times daily. CYP3A4/5 genotyping and antibiotic susceptibility tests were also performed. Successful eradication was defined as 13negative C-UBTs 4 weeks after treatment. The primary endpoint was to compare the efficacy of 7-day and 14-day regimens as first-line treatments, which were assessed by intention-to-treat (ITT) and per-protocol (PP) analyses. The secondary endpoints included adverse effects. A total of 337 dyspeptic patients who underwent gastroscopy were included; 105 patients (31.1%) were diagnosed with H. pylori infection, and 101 patients were randomly assigned to each regimen. No dropouts were detected. The antibiotic resistance rate was 33.3% for clarithromycin, 29.4% for metronidazole, and 27.7% for levofloxacin. The CYP3A4 genotype was associated with 100% rapid metabolism. The H. pylori eradication rates for the 7-day and 14-day regimens were 84.4%, 95% CI 74.3-94.2 and 94%, 95% CI 87.4-100, respectively (RR difference 0.25, 95% CI 0.03-0.53, p value = 0.11). Interestingly, the 14-day regimen led to 100% eradication in the clarithromycin-resistant group. Among the patients in the 7-day regimen group, only two exhibited resistance to clarithromycin; unfortunately, neither of them achieved a cure from H. pylori infection. The incidence of adverse events was similar in both treatment groups, occurring in 29.4% (15/51) and 28% (14/50) of patients in the 7-day and 14-day regimens, respectively. No serious adverse reactions were reported. In conclusion, 14 days of vonoprazan-based bismuth quadruple therapy is highly effective for H. pylori eradication in areas with high levels of dual clarithromycin and levofloxacin resistance.

Efficacy Assessment of the Co-Administration of Vancomycin and Metronidazole in Clostridioides difficile-Infected Mice Based on Changes in Intestinal Ecology.

Vancomycin (VAN) and metronidazole (MTR) remain the current drugs of choice for the treatment of non-severe Clostridioides difficile infection (CDI); however, while their co-administration has appeared in clinical treatment, the efficacy varies greatly and the mechanism is unknown. In this study, a CDI mouse model was constructed to evaluate the therapeutic effects of VAN and MTR alone or in combination. For a perspective on the intestinal ecology, 16S rRNA amplicon sequencing and non-targeted metabolomics techniques were used to investigate changes in the fecal microbiota and metabolome of mice under the co-administration treatment. As a result, the survival rate of mice under co-administration was not dramatically different compared to that of single antibiotics, and the former caused intestinal tissue hyperplasia and edema. Co-administration also significantly enhanced the activity of amino acid metabolic pathways represented by phenylalanine, arginine, proline, and histidine, decreased the level of deoxycholic acid (DCA), and downregulated the abundance of beneficial microbes, such as Bifidobacterium and Akkermansia. VAN plays a dominant role in microbiota regulation in co-administration. In addition, co-administration reduced or increased the relative abundance of antibiotic-sensitive bacteria, including beneficial and harmful microbes, without a difference. Taken together, there are some risks associated with the co-administration of VAN and MTR, and this combination mode should be used with caution in CDI treatment.

Mesoporous cobalt-manganese layered double hydroxides promote the activation of calcium sulfite for degradation and detoxification of metronidazole.

Metronidazole (MNZ), a commonly used antibiotic, poses risks to water bodies and human health due to its potential carcinogenic, mutagenic, and genotoxic effects. In this study, mesoporous cobalt-manganese layered double hydroxides (CoxMny-LDH) with abundant oxygen vacancies (Ov) were successfully synthesized using the co-precipitation method and used to activate calcium sulfite (CaSO3) with slight soluble in water for MNZ degradation. The characterization results revealed that Co2Mn-LDH had higher specific areas and exhibited good crystallinity. Co2Mn-LDH/CaSO3 exhibited the best catalytic performance under optimal conditions, achieving a remarkable MNZ degradation efficiency of up to 98.1 % in only 8 min. Quenching experiments and electron paramagnetic resonance (EPR) tests showed that SO4•- and 1O2 played pivotal roles in the MNZ degradation process by activated CaSO3, while the redox cycles of Co2+/Co3+ and Mn3+/Mn4+ on the catalyst surface accelerated electron transfer, promoting radical generation. Three MNZ degradation routes were put forward based on the density functional theory (DFT) and liquid chromatography-mass spectrometer (LC-MS) analysis. Meanwhile, the toxicity analysis result demonstrated that the toxicity of intermediates post-catalytic reaction was decreased. Furthermore, the Co2Mn-LDH/CaSO3 system displayed excellent stability, reusability, and anti-interference capability, and achieved a comparably high removal efficiency across various organic pollutant water bodies. This study provides valuable insights into the development and optimization of effective heterogeneous catalysts for treating antibiotic-contaminated wastewater.

Comparison of the Efficacy of 12-day Concomitant Quadruple Therapy versus 14-day High dose Dual Therapy as a First-line H. pylori Eradication Regimen.

Background/Aims: Helicobacter pylori (H. pylori) is the most prevalent infection in the world and is strongly associated with gastric adenocarcinoma, lymphoma and gastric or duodenal ulcers. Different regimens have been used for H. pylori eradication. We aimed to compare the efficacy of two different regimens as first-line H. pylori eradication regimens, in an area with high antibiotic resistance. Methods: In this RCT, we assigned 223 patients with H. pylori infection, who were naïve to treatment. They were randomly divided into two groups to receive either 12-day concomitant quadruple therapy (consisting of pantoprazole 40 mg, amoxicillin 1 g, clarithromycin 500 mg, and metronidazole 500 mg every 12 hours) or 14-day high dose dual therapy (consisting of esomeprazole 40 mg and amoxicillin 1 g TDS). H. pylori eradication was assessed eight weeks after the end of treatment. Results: H. pylori eradication rate by PP analysis for 12-day concomitant quadruple therapy and 14-day high dose dual therapy were 90.4% and 79.1%, respectively (p=0.02). According to ITT analysis, the eradication rates were 86.2% and 76.3%, respectively (p=0.06). Adverse drug reactions were 12.3% in high dose dual therapy and 36.8% in concomitant quadruple therapy (p<0.001). Conclusions: Twelve-day concomitant therapy seems to be an acceptable regimen for first-line H. pylori eradication in Iran, a country with a high rate of antibiotic resistance. Although, high dose dual therapy did not result in an ideal eradication rate, but it had fewer drug side effects than the 12-day concomitant regimen.

Continuing Medical Education Questions: April 2024.

Article Title: Effectiveness of Helicobacter pylori treatments according to antibiotic resistance.

14-day tailored PCR-guided triple therapy versus 14-day non-Bismuth concomitant quadruple therapy for Helicobacter pylori eradication: A multicenter, open-label randomized noninferiority controlled trial.

BACKGROUND: The systematic use of susceptibility testing and tailored first-line treatment for Helicobacter pylori eradication has yet to be established. AIM: To compare 14-day tailored PCR-guided triple therapy to 14-day non-Bismuth concomitant quadruple therapy for first-line Helicobacter pylori eradication. PATIENTS AND METHODS: We performed a multicenter, parallel-group, randomized noninferiority controlled trial. Naive adult patients with Helicobacter pylori infection were treated with 14-day tailored PCR-guided triple therapy (esomeprazole 40 mg and amoxicillin 1000 mg b.d. plus clarithromycin 500 mg or levofloxacin 500 mg b.d. according to clarithromycin susceptibility) or 14-day non-Bismuth concomitant quadruple therapy (esomeprazole 40 mg, amoxicillin 1000 mg, clarithromycin 500 mg, and metronidazole 500 mg b.d.). The primary endpoint was H. pylori eradication. RESULTS: We screened 991 patients for eligibility and randomized 241 patients. The first-line eradication rate was 99.2% in the tailored PCR-guided group and 95.9% in the control group (ITT population; absolute difference of +3.30%, with a lower bound of CI at -0.68%). Both first-line therapies were well tolerated, with a formally significant difference in favor of the tailored PCR-guided group (61.4% vs. 41.2%, p = 0.003). Economic analyses revealed a lower cost of the tailored PCR-guided arm, with a 92% chance of being jointly more effective and less expensive than the control arm in the ITT population. CONCLUSION: In a country with a high level of clarithromycin resistance, the results of our study demonstrated the noninferiority of 14-day tailored PCR-guided triple therapy as a first-line H. pylori eradication therapy compared to 14-day non-Bismuth quadruple therapy (ClinicalTrials.gov NCT02576236).

Refractoriness to anti-Helicobacter pylori treatment attributed to phenotypic resistance patterns in patients with gastroduodenopathy in Guayaquil-Ecuador.

BACKGROUND: Treatment of Helicobacter pylori gastric infection is complex and associated with increased rates of therapeutic failure. This research aimed to characterize the H. pylori infection status, strain resistance to antimicrobial agents, and the predominant lesion pattern in the gastroduodenal mucosa of patients with clinical suspicion of refractoriness to first- and second-line treatment who were diagnosed and treated in a health center in Guayaquil, Ecuador. METHODS: A total of 374 patients with upper gastrointestinal symptoms and H. pylori infection were preselected and prescribed one of three triple therapy regimens for primary infection, as judged by the treating physician. Subsequently, 121 patients who returned to the follow-up visit with persistent symptoms after treatment were studied. RESULTS: All patients had H. pylori infection. Histopathological examination diagnosed chronic active gastritis in 91.7% of cases; premalignant lesions were observed in 15.8%. The three triple therapy schemes applied showed suboptimal efficacy (between 47.6% and 77.2%), with the best performance corresponding to the scheme consisting of a proton pump inhibitor + amoxicillin + levofloxacin. Bacterial strains showed very high phenotypic resistance to all five antimicrobials tested: clarithromycin, 82.9%; metronidazole, 69.7%; amoxicillin and levofloxacin, almost 50%; tetracycline, 38.2%. Concurrent resistance to clarithromycin-amoxicillin was 43.4%, to tetracycline-metronidazole 30.3%, to amoxicillin-levofloxacin 27.6%, and to clarithromycin-metronidazole 59.2%. CONCLUSIONS: In vitro testing revealed resistance to all five antibiotics, indicating that H. pylori exhibited resistance phenotypes to these antibiotics. Consequently, the effectiveness of triple treatments may be compromised, and further studies are needed to assess refractoriness in quadruple and concomitant therapies.

Synthesis of new trypanocidal agents from the hybridisation of metronidazole and eugenol analogues.

Nitroimidazole compounds are well-known bioactive substances, and the structural activity relationship has been reported whereby the position of the nitro group within the imidazole ring has a large influence on the activity. This study focuses on synthesising new trypanocidal agents from the hybridisation of metronidazole with different natural phenols (eugenol, dihydroeugenol and guaiacol). Two different coupling methodologies have been explored in order to analyse the influence of the connector on bioactivity: i) classic direct esterification (AD compounds) and ii) "click" chemistry using a triazole connector (AC compounds). The in vitro trypanocidal tests show good results for both AC and AD hybrid compounds against both epimastigote and trypomastigote forms of T. cruzi. In silico studies showed positive data for most of the synthesised compounds and, in general present low toxicological risks. The AC compounds present lower ClogP (lipophilicity) values than those found for the AD series and higher TPSA (topological polar surface area) values, suggesting lower lipophilicity may be related to the presence of the triazole connector. The AD series compounds have higher Drug Score values than the AC series derivatives, suggesting better general properties for a pharmacological action.

Exploring novel pyrazole-nitroimidazole hybrids: Synthesis and antiprotozoal activity against the human pathogen trichomonas vaginalis.

Trichomoniasis, a prevalent sexually transmitted infection (STI) caused by the protozoan Trichomonas vaginalis, has gained increased significance globally. Its relevance has grown in recent years due to its association with a heightened risk of acquiring and transmitting the human immunodeficiency virus (HIV) and other STIs. In addition, many publications have revealed a potential link between trichomoniasis and certain cancers. Metronidazole (MTZ), a nitroimidazole compound developed over 50 years ago, remains the first-choice drug for treatment. However, reports of genotoxicity and side effects underscore the necessity for new compounds to address this pressing global health concern. In this study, we synthesized ten pyrazole-nitroimidazoles 1(a-j) and 4-nitro-1-(hydroxyethyl)-1H-imidazole 2, an analog of metronidazole (MTZ), and assessed their trichomonacidal and cytotoxic effects. All compounds 1(a-j) and 2 exhibited IC50 values ≤ 20 µM and ≤ 41 µM, after 24 h and 48 h, respectively. Compounds 1d (IC50 5.3 µM), 1e (IC50 4.8 µM), and 1i (IC50 5.2 µM) exhibited potencies equivalent to MTZ (IC50 4.9 µM), the reference drug, after 24 h. Notably, compound 1i showed high anti-trichomonas activity after 24 h (IC50 5.2 µM) and 48 h (IC50 2.1 µM). Additionally, all compounds demonstrated either non-cytotoxic to HeLa cells (CC50 > 100 µM) or low cytotoxicity (CC50 between 69 and 100 µM). These findings suggest that pyrazole-nitroimidazole derivatives represent a promising heterocyclic system, serving as a potential lead for further optimization in trichomoniasis chemotherapy.

High antibiotic resistance rates in Helicobacter pylori strains in Turkey over 20 years: implications for gastric disease treatment.

OBJECTIVE: Helicobacter pylori (Hp) eradication therapy is crucial for preventing the development of gastritis, peptic ulcers, and gastric cancer. An increase in resistance against antibiotics used in the eradication of Hp is remarkable. This meta-analysis aims to examine the resistance rates of Hp strains isolated in Turkey over the last 20 years against clarithromycin (CLR), metronidazole (MTZ), levofloxacin (LVX), tetracycline (TET), and amoxicillin (AMX) antibiotics. BASIC METHODS: Literature search was carried out in electronic databases, by searching articles published in Turkish and English with the keywords ' helicobacter pylori ' or 'Hp' and 'antibiotic resistance' and 'Turkey'. That meta-analysis was carried out using random-effect model. First, the 20-year period data between 2002 and 2021 in Turkey were planned to be analyzed. As a second stage, the period between 2002 and 2011 was classified as Group 1, and the period between 2012 and 2021 as Group 2 for analysis, with the objective of revealing the 10-year temporal variation in antibiotic resistance rates. MAIN RESULTS: In gastric biopsy specimens, 34 data from 29 studies were included in the analysis. Between 2002-2021, CLR resistance rate was 30.9% (95% CI: 25.9-36.2) in 2615 Hp strains. Specifically, in Group 1, the CLR resistance rate was 31% in 1912 strains, and in Group 2, it was 30.7% in 703 strains. The MTZ resistance rate was found to be 31.9% (95% CI: 19.8-45.4) in 789 strains, with rates of 21.5% in Group 1 and 46.6% in Group 2. The overall LVX resistance rate was 25.6%, with rates of 26.9% in Group 1 and 24.8% in Group 2. The 20-year TET resistance rate was 0.8%, with 1.50% in Group 1 and 0.2% in Group 2. The overall AMX resistance rate was 2.9%, 3.8% between 2002-2011, and 1.4% between 2012-2021. PRINCIPAL CONCLUSION: Hp strains in Turkey exhibit high resistance rates due to frequent use of CLR, MTZ, and LVX antibiotics. However, a significant decrease has been observed in TET and AMX resistance to Hp in the last 10 years. Considering the CLR resistance rate surpasses 20%, we suggest reconsidering the use of conventional triple drug therapy as a first-line treatment. Instead, we recommend bismuth-containing quadruple therapy or sequential therapies (without bismuth) for first-line treatment, given the lower rates of TET and AMX resistance. Regimens containing a combination of AMX, CLR, and MTZ should be given priority in second-line therapy. Finally, in centers offering culture and antibiogram opportunities, regulating the Hp eradication treatment based on the antibiogram results is obviously more appropriate.

Comparison of Antibacterial Efficacy of Triple Antibiotic-Loaded Hydrogel Versus Modified Triple Antibiotic-Loaded Hydrogel as Intracanal Medicament Against Enterococcus faecalis: An In vitro Study.

OBJECTIVE: Triple antibiotic paste (TAP) is known to have an essential role in the success of endodontic treatment by eliminating pathogens from the root canal system. Unfortunately, it causes discolouration and cytotoxicity at high concentrations. The objective of this research was to assess and compare the antimicrobial effectiveness of various concentrations (1 mg, 5 mg, 10 mg) of TAP, TAP hydrogel (TAPH), M-TAP, and M-TAP hydrogel (MTAPH) against Enterococcus faecalis. METHODS: The agar well diffusion method was used to assess the antibiotic sensitivity of the following intracanal medicaments: TAP (ciprofloxacin, metronidazole, and minocycline) mixed in a ratio of 1: 1: 1; TAPH, M-TAP (ciprofloxacin, metronidazole, and amoxicillin), M-TAPH and plain hydrogel. Each tested medicament was individually evaluated for its antimicrobial activity against Enterococcus faecalis. Structural and topographical characterisation were analysed using a Scanning Electron Microscope (SEM) and interpreted using ImageJ software. A microdilution broth test was performed to examine the minimum inhibitory concentration and minimum bactericidal concentration (MBC) of M-TAP and TAP. RESULTS: Except for the plain hydrogel, M-TAP and hydrogel and TAP and hydrogel showed significantly varied inhibitory zones at different concentrations. M-TAPH showed the highest mean zone of inhibition of 21.6, 33.33 and 38.0 mm at a concentration of 1, 5, and 10 mg/mL when compared to TAPH, which showed a mean zone of inhibition of 3.3 mm,12.3 mm, 21.3 mm at the respective concentrations. The MIC study shows that more than 75% of Enterococcus faecalis growth was inhibited by M-TAP at a concentration of 5 µg/mL, whereas TAP showed inhibition at a concentration of 35 µg/mL. MBC results indicate that almost 99.9% of the bacterial population was killed at a concentration of 100 µg/mL (10-1) for TAP and 10 µg/mL (10-2) for M-TAP. CONCLUSION: The antibacterial efficacy of M-TAP was significantly higher than TAP. Application of M-TAP at lower doses is advised to overcome the disadvantages seen with TAP.

Facet-dependent activation of oxalic acid over hematite nanocrystals under the irradiation of visible light for efficient degradation of pollutants.

Naturally occurring hematite has been widely studied in the Fenton-like system for water pollutant remediation due to its abundance and non-toxicity. However, its inadequate catalytic activity results in difficulty in effectively degrading pollutants in the catalytic degradation system that it constitutes. Thus, we constructed a photochemical system composed of hematite with {001} facet of high activity facet and low-cost and non-toxic oxalic acid (OA) for the removal of various types of pollutants. The removal rate for the degradation of metronidazole, tetracycline hydrochloride, Rhodamine B, and hexavalent chromium by hematite nanoplate with the exposed {001} facet activating OA under visible light irradiation was 4.75, 2.25, 2.33, and 2.74 times than that by the exposed {110} facet, respectively. Density functional theory (DFT) calculation proved that the OA molecule was more easily adsorbed on the {001} facet of hematite than that on the {110} facet, which would favor the formation of the more Fe(III)-OA complex and reactive species. In addition, the reactive site of metronidazole for the attraction of radicals was identified on the basis of the DFT calculation on the molecular occupied orbitals, and the possible degradation pathway for metronidazole included carbon chain fracture, hydroxyethyl-cleavage, denitrogenation, and hydroxylation. Thus, this finding may offer a valuable direction in designing an efficient iron-based catalyst based on facet engineering for the improved activity of Fenton-like systems such as OA activation.

A comparative analysis of univariate versus multivariate eco-friendly spectrophotometric manipulations for resolving severely overlapped spectra of vonoprazan and amoxicillin new combination.

Vonoprazan and amoxicillin are pharmacological combinations that demonstrate synergistic effects in treating Helicobacter pylori (H. pylori), a global public health concern associated with peptic ulcer disease and gastric cancer. Four spectrophotometric methods were developed, including two univariate techniques (Fourier self-deconvolution and ratio difference) and two multivariate chemometric approaches (partial least squares and principal component regression). These methods provide innovative solutions for effectively resolving and accurately quantifying the overlapping spectra of vonoprazan and amoxicillin. The concentration ranges covered were 3-60 µg ml-1 for vonoprazan and 5-140 µg ml-1 for amoxicillin. To assess the environmental sustainability of the methodologies, various measures such as the Green Analytical Procedure Index (GAPI), National Environmental Method Index (NEMI), Analytical GREEnness Calculator, and Analytical Eco-scale, as well as RGB12 and hexagon toll were implemented. The validation of the developed techniques was carried out in compliance with ICH standards. The present study is highly significant because it is the first time that the mixture has been determined using the current approaches. The comparative analysis demonstrated no significant difference in terms of accuracy and precision compared to reference HPLC method (p = 0.05). The established spectrophotometric methods offer a straightforward, rapid, and cost-effective alternative to complex analytical techniques for determining the vonoprazan and amoxicillin mixture. They show potential for routine analysis in research laboratories and pharmaceutical industries.

Development of New PCR Protocols to Detect Genetic Diversity in the Metronidazole Metabolism Genes in Susceptible and Refractory Clinical Samples of Giardia duodenalis.

PURPOSE: Investigating the genetic variation in thioredoxin reductase (TrxR) and nitroreductase (NR) genes in both treatment-resistant and -sensitive Giardia duodenalis isolates can provide valuable information in identifying potential markers of resistance to metronidazole. The rapid increase in metronidazole treatment failures suggests the presence of genetic resistance mechanisms. By analyzing these genes, researchers can gain insights into the efficacy of metronidazole against G. duodenalis and potentially develop alternative treatment strategies. In this regard, four G. duodenalis isolates (two clinically sensitive and two clinically resistant to metronidazole) were collected from various hospitals of Shiraz, southwestern Iran. METHODS: Parasitological methods including sucrose flotation and microscopy were employed for the primary confirmation of G. duodenalis cysts in stool samples. Microscopy-positive samples were approved by SSU-PCR amplification of the parasite DNA. All four positive G. duodenalis specimens at SSU-PCR were afterward analyzed utilizing designed primers based on important metronidazole metabolism genes including TrxR, NR1, and NR2. RESULTS: Unlike TrxR gene, the results of NR1 and NR2 genes showed that there are non-synonymous variations between sequences of treatment-sensitive and -resistant samples compared to reference sequences. Furthermore, the outcomes of molecular docking revealed that there is an interaction between the protein sequence and spatial shape of treatment-resistant samples and metronidazole in the position of serine amino acid based on the NR1 gene. CONCLUSION: This issue can be one of the possible factors involved in the resistance of Giardia parasites to metronidazole. To reach more accurate results, a large sample size along with simulation and advanced molecular dynamics investigations are needed.