One-step online analysis of antibiotics in highly saline seawater by nano-based slug-flow microextraction

The transition to mass spectrometry (MS) in the analysis of antibiotics in the marine environment is highly desirable, particularly in the enhancement of sensitivity for high-salinity (3.5 wt%) seawater samples. However, the persistence of complex operational procedures poses substantial challenges to this transition. In this study, a rapid method for the online analysis of antibiotics in seawater samples via nano-electrospray ionization (nESI) MS based on slug-flow microextraction (SFME) has been proposed. Comparisons with other methods, complex laboratory setups for sample processing are now seamlessly integrated into a single online step, completing the entire process, including desalination and detection, SFME-nESI-MS provides faster results in less than 2 min while maintaining sensitivity comparable to that of other detection methods. Using SFME-nESI, six antibiotics in high-salinity (3.5 wt%) seawater samples have been determined in both positive and negative ion modes. The proposed method successfully detected clarithromycin, ofloxacin, and sulfadimidine in seawater within a linear range of 1-1000 ng mL-1 and limit of detection (LOD) of 0.23, 0.06, and 0.28 ng mL-1, respectively. The method recovery was from 92.8% to 107.3%, and the relative standard deviation was less than 7.5%. In addition, the response intensity of SFME-nESI-treated high-salinity (3.5 wt%) samples surpassed that of untreated medium-salinity (0.35 wt%) samples by two to five orders of magnitude. This advancement provides an exceptionally simplified protocol for the online rapid, highly sensitive, and quantitative determination of antibiotics in high-salinity (3.5 wt%) seawater.

Global insight into the occurrence, treatment technologies and ecological risk of emerging contaminants in sanitary sewers: Effects of the SARS-CoV-2 coronavirus pandemic

The SARS-CoV-2 pandemic caused changes in the consumption of prescribed/non-prescribed drugs and the population's habits, influencing the detection and concentration of emerging contaminants (ECs) in sanitary sewage and harming environmental and health risks. Therefore, the present work sought to discuss current literature data on the effects of the "COVID-19 pandemic factor" on the quality of raw sewage produced over a five-year period (2018-2019: pre-pandemic; 2020-2022: during the pandemic) and biological, physical, chemical and hybrid treatment technologies, influencing factors in the removal of ECs and potential ecological risks (RQs). Seven hundred thirty-one publications correlating sewage and COVID-19 were identified: 184 pre-pandemic and 547 during the pandemic. Eight classes and 37 ECs were detected in sewage between 2018 and 2022, with the "COVID-19 pandemic factor" promoting an increase in estrogens (+31,775 %), antibiotics (+19,544 %), antiepileptics and antipsychotics (+722 %), pesticides (+200 %), analgesics, anti-inflammatories and anticoagulants (+173 %), and stimulant medications (+157 %) in sanitary sewage. Among the treatment systems, aerated reactors integrated into biomembranes removed >90 % of cephalexin, clarithromycin, ibuprofen, estrone, and 17β-estradiol. The absorption, adsorption, and biodegradation mechanisms of planted wetland systems contributed to better cost-benefit in reducing the polluting load of sewage ECs in the COVID-19 pandemic, individually or integrated into the WWTP. The COVID-19 pandemic factor increased the potential ecological risks (RQs) for aquatic organisms by 40 %, with emphasis on clarithromycin and sulfamethoxazole, which changed from negligible risk and low risk to (very) high risk and caffeine with RQ > 2500. Therefore, it is possible to suggest that the COVID-19 pandemic intensified physiological, metabolic, and physical changes to different organisms in aquatic biota by ECs during 2020 and 2022.

Trace polymer coated clarithromycin spherulites: Formation mechanism, improvement in pharmaceutical properties and development of high-drug-loading direct compression tablets

Clarithromycin (CLA) is a high dose antibiotic drug exhibiting poor flowability and tabletability, making the tablet development challenging. This study aims to develop spherulitic CLA by introducing trace amount of polymer in crystallization solution. Its formation mechanism, physicochemical properties and potential for the direct compression (DC) tablets development were also investigated. Morphological analyses and the in situ observation on crystallization process revealed that the CLA spherulites are formed by fractal branching growth from both sides of the threadlike precursor fibers. 1H NMR analysis and nucleation time monitoring indicated that the existence of hydroxypropyl cellulose in solution slowed down the crystal nucleation and growth rate by forming hydrogen bonding interactions with CLA molecules, making the system maintain high supersaturation, providing high driving forces for CLA spherulitic growth. In comparison to commercial CLA, the CLA spherulites exhibit profoundly improved flowability, tabletability and dissolution behaviors. XPS, contact angle and Raman mapping analysis confirmed the presence of a thin HPC layer on the surfaces and interior of CLA spherulitic particles, resulting in increasing powder plasticity, interparticulate bonding strength and powder wettability, thus better tabletability and dissolution performances. The improved flowability and tabletability of CLA spherulites also enabled the successful development of DC tablet formulation with a high CLA loading (82.8 wt%) and similar dissolution profiles to reference listed drug. This study provides a novel solid form of CLA with superior manufacturability for further development.

Continuing Medical Education Questions: April 2024

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

Study on Drug Resistance to Treatment for Ureaplasma Urealyticum Infections in the Female Genital Tract

BACKGROUND

Ureaplasma urealyticum (U. urealyticum) commonly occurs in female genitourinary infections, and its different biovars and serotypes have varying degrees of resistance to different antibiotics. This study aimed to ex-plore the characteristics of U. urealyticum infection and drug-resistant profiles in Chinese females.

METHODS

We included 1,045 females with genital tract infections who visited Tangshan Workers' Hospital and Tangshan Maternal and Child Health Center from September 2017 to December 2018. The bacteria were selectively cultured, and drug sensitivity experiments were conducted. Eight pairs of oligonucleotide primers were designed, and polymerase chain reaction (PCR) was performed to amplify specific DNA fragments to perform bacterial strain typing.

RESULTS

Among the 1,045 participants included, 566 (54.11%) participants were positive for mycoplasma infection. There were 432 (41.34%) participants with U. urealyticum infection, accounting for 76.33% of the positive participants. The infection rate of U. urealyticum was the highest in females who were 21 - 30 years old, followed by those who were 31 - 40 years old. Ureaplasma urealyticum showed the highest sensitivity to tetracyclines and the greatest resistance to quinolones. The biovar 1 of U. urealyticum with the highest detection rate of serotype 4, accounted for 66.88%. The biovar 2 of U. urealyticum mainly showed mixed subtypes 2 and 3. Biovar 2 showed higher resistance to sparfloxacin, clarithromycin, josamycin, and doxycycline than biovar 1.

CONCLUSIONS

Women might be more susceptible to U. urealyticum, especially if they are of childbearing age. Urea-plasma urealyticum is mainly caused by a single serotype 6 infection. The resistance of U. urealyticum to quinolone (e.g., norfloxacin) is a great concern. Sparfloxacin, clarithromycin, ciprofloxacin, and doxycycline might be more suitable for people with biovar 1 infection. Biotyping may facilitate clinical drug use and help avoid the emergence of drug-resistant strains.

Assessing prescription of antibiotics after vaccination against pneumococcal pneumonia; using prescription sequence symmetry analysis

OBJECTIVES

Prescription sequence symmetry analysis (PSSA) is used to detect adverse event signals using administrative claims databases. In this study, we investigated whether PSSA can be applied to gauge the effects of PCV13 vaccination on antibiotic prescription rates in elderly patients.

METHODS

We studied prescription records of patients aged 65 or older between 1 January 2014 and 31 December 2020, from the Helsana Swiss claims database. PSSA was performed to explore the relationship between 13-valent pneumococcal conjugate vaccine (PCV13) and six antibiotics recommended by the Swiss Society of Infectious Diseases for community-acquired pneumonia treatment (amoxicillin-clavulanate, azithromycin, clarithromycin, doxycycline, levofloxacin, and moxifloxacin), three additional antibiotics (amoxicillin, ciprofloxacin, and fosfomycin), and ten control drugs.

RESULTS

Amoxicillin-clavulanate, clarithromycin, and levofloxacin were more likely to be prescribed before than after vaccination, for all time windows between 25 and 104 weeks. Adjusted sequence ratio (ASR) values ranged from 0.599 to 0.614, 0.508 to 0.568, and 0.514 to 0.752, respectively. Lower prescription rates after vaccination were also observed for azithromycin (all time windows between 38 and 104 weeks, ASR 0.705-0.739) and moxifloxacin (all time windows between 52 and 104 weeks, ASR 0.658-0.772). PCV13 did not have statistically significant associations with doxycycline, amoxicillin, ciprofloxacin, fosfomycin, or any of the ten controls.

DISCUSSION

The lower prescription rate of antibiotics for community-acquired pneumonia after vaccination could be attributed to a protective effect of PCV13. This novel application of PSSA can be used to compare the real-world impact of other vaccines on drug consumption.

Kaempferia parviflora Extracellular Vesicle Loaded with Clarithromycin for the Treatment of Helicobacter pylori Infection

Purpose

Kaempferia parviflora extracellular vesicles (KPEVs) have been reported as promising nanovesicles for drug delivery. This study aimed to load clarithromycin (CLA) into KPEVs (KPEVS-CLA) and determine the physical properties, drug-releasing efficiency, gastric cell uptake, anti-H. pylori activities, and anti-inflammatory responses in comparison with free CLA and KPEVs.

Methods

The size and surface charge of KPEVs-CLA were evaluated using dynamic light scattering and visualized using a transmission electron microscope. The encapsulation efficiency (EE%), loading capacity (LC%), and drug release of KPEVs-CLA were examined using HPLC. Anti-H. pylori growth and anti-adhesion were evaluated. IL-8 gene expression, NF-κB signaling proteins, and anti-inflammatory profiles were examined using qRT-PCR, Western blotting, and Bio-Plex immunoassay, respectively. Anti-chemotaxis was then examined using a Transwell assay.

Results

KPEVs-CLA were intact and showed a negative surface charge similar to that of KPEVs. However, slightly enlarged KPEVs were observed. CLA was successfully loaded into KPEVs with EE of 93.45% ± 2.43%, LC of 9.3% ± 3.02%. CLA release in the PBS and gastric mimic buffer with Fickian diffusion (n ≤ 0.43) according to Korsmeyer-Peppas kinetic model (R2=0.98). KPEVs-CLA was localized in the gastric cells' cytoplasm and perinuclear region. Anti-H. pylori growth and anti-H. pylori adhesion of KPEVs-CLA were compared with those of free CLA with no cytotoxicity to adenocarcinoma gastric cells. KPEVs-CLA significantly reduced IL-8, G-CSF, MIP-1α, and MIP-1β levels. Moreover, KPEVs-CLA showed a superior effect over CLA in reducing G-CSF, MIP-1α, and NF-κB phosphorylation and monocyte chemotactic activities.

Conclusion

KPEVs serve as potential carriers of CLA. They exhibited a higher efficiency in inhibiting gastric cell inflammation mediated by H. pylori infection than free CLA. The establishment of KPEVs-CLA as a nanodrug delivery model for H. pylori treatment could be applied to other plant extracellular vesicles or loaded with other cancer drugs for gastric cancer treatment.

Adsorption of clarithromycin on polystyrene nanoplastics surface and its combined adverse effect on serum albumin

Emerging contaminants, such as antibiotics and nanoplastics, have garnered significant attention due to their potential adverse effects on diverse ecosystems. Antibiotic adsorption on the surface of nanoplastics potentially facilitates their long-range transport, leading to the synergistic effects of the complex. This research aims to examine the adsorption behavior of clarithromycin binding with polystyrene nanoplastics surface as well as their interaction between drug adsorbed polystyrene nanoplastics with serum albumin. Different spectroscopic methods were used to find out the interaction between clarithromycin and nanoplastics, under stimulated physiological conditions UV-vis spectroscopy showed a maximum of 22.8% percentage of the drug adsorbed with the polystyrene nanoplastics surface after 6 h of incubation. The fluorescence spectroscopic results demonstrated that the fluorescence intensity of serum albumin was quenched by the clarithromycin-polystyrene nanoplastics (CLA-PSNP) complex through static quenching. We calculated the number of binding stoichiometry, binding constants, and thermodynamic parameters. This study revealed that the CLA-PSNP binds to serum albumin spontaneously and its hydrophobic interactions played a significant role. The conformational changes in the structure of serum albumin were revealed from the findings of synchronous fluorescence spectra, CD spectra, and 3D fluorescence spectra, leading to the disturbance in functional activity. This study focuses valuable insights into the intermolecular interactions between clarithromycin-adsorbed polystyrene nanoplastics and serum albumin and its potential molecular-level biological toxicity.

In vitro susceptibility of nontuberculous mycobacteria in China

OBJECTIVES

This study aimed to measure the prevalence of resistance to antimicrobial agents, and explore the risk factors associated with drug resistance by using nontuberculous Mycobacteria (NTM) isolates from China.

METHODS

A total of 335 NTM isolates were included in our analysis. Broth dilution method was used to determine in vitro drug susceptibility of NTM isolates.

RESULTS

Clarithromycin (CLA) was the most potent drug for Mycobacterium intracellulare (MI). The resistance rate of 244 MI isolates to CLA was 21%, yielding a minimum inhibitory concentrations (MIC)50 and MIC90 of 8 and 64 mg/L, respectively. 51% of 244 MI isolates exhibited resistance to amikacin (AMK). For 91 Mycobacterium abscessus complex (MABC) isolates, 6 (7%) and 49 (54%) isolates were categorized as resistant to CLA at day 3 and 14, respectively. The resistance rate to CLA for Mycobacterium abscessus subspecies abscessus (MAA) was dramatically higher than that for Mycobacterium abscessus subspecies massiliense (MAM). Additionally, the percentage of patients presenting fever in the CLA-susceptible group was significantly higher than that in the CLA-resistant group.

CONCLUSIONS

Our data demonstrate that approximate one fifth of MI isolates are resistant to CLA. We have identified a higher proportion of CLA-resistant MAA isolates than MAM. The patients caused by CLA-resistant MI are at low risk for presenting with fever relative to CLA-susceptible group.

Mycobacterium abscessus endocarditis post cardiac cathetrisation-a case report and review of 25 cases (2001-2023)

47 year male underwent percutaneous transluminal coronary angioplasty elsewhere, developed fever after two days, and treated empirically in various hospitals for the subsequent two months. Echocardiography showed vegetation in aortic valve and blood cultures were negative. He was then diagnosed as a case of endocarditis due to M. abscessus in our centre by repeated positive blood cultures. After treatment with Imipenem, Amikacin and clarithromycin in the background of pancytopenia, patient was discharged with advice to continue antibiotics and planned for aortic valve replacement. Patient was noncompliant to treatment, readmitted with worsening symptoms, developed multiorgan failure and subsequently died of infection.

Primary antibiotic resistance of Helicobacter pylori in India over the past two decades: A systematic review

BACKGROUND

Helicobacter pylori antibiotic resistance has undergone vast changes in the last two decades. No systematic review has been done on the prevalence of antibiotic resistant H. pylori in India in the last two decades. We evaluated the pattern of resistance rates across various regions of India.

MATERIALS AND METHODS

A systematic review of the geographical variations in antibiotic resistance pattern of H. pylori was conducted using PubMed, Google Scholar, Web of Science, Science Direct, etc. for articles published between January 1, 2000 and May 30, 2023. Random effects-model-based Cochran's Q test, I2 statistics, and chi-squared tests were used to measure heterogeneity.

RESULTS

The overall resistance was highest against metronidazole (77.65%) followed by amoxicillin (37.78%), levofloxacin (32.8%), clarithromycin (35.64%), furazolidone (12.03%), and tetracycline (11.63%). 14.7% of the H. pylori isolates were multi-drug resistant. Under meta-analysis of each antibiotic, high heterogeneity levels were observed having I2 ranges from 86.53% to 97.70% at p < 0.0001. In sub-group analysis, Metronidazole has a stable rate of resistance as compared to other antibiotics. Other antibiotics have had a downtrend in the last 5 years except for levofloxacin, which has had an uptrend in the resistance rate for the past 5 years. Hence, one should avoid using metronidazole for any kind of first-line treatment.

CONCLUSIONS

Metronidazole resistance is high in most regions of India except Assam and Mumbai while clarithromycin is found to be ineffective in South India, Gujarat, and Kashmir. As compared to other antibiotics, resistance to amoxicillin is generally low except in certain regions (Hyderabad, Chennai, and the Gangetic belt of North India). Tetracycline and Furazolidone have the least resistance rates and should be part of anti- H. pylori regimens. The resurgence of high single and multidrug resistance to the commonly used drugs suggests the need for newer antibiotics and regular resistance surveillance studies.

Antibiotic resistance of Helicobacter pylori in Chinese children: A multicenter study from 2016 to 2023

BACKGROUND

To investigate the antibiotic resistance of Helicobacter pylori (H. pylori) strains to clarithromycin, metronidazole, amoxicillin, levofloxacin, furazolidone, and tetracycline in Chinese children.

MATERIALS AND METHODS

This multicenter, retrospective study was conducted from January 2016 through May 2023. Gastric mucosa biopsies were obtained from pediatric participants who underwent upper gastrointestinal endoscopy at 96 hospitals in northern, southwestern, and southeastern China. The susceptibility of H. pylori to six commonly used antibiotics was determined by agar dilution method.

RESULTS

Among the 3074 H. pylori isolates, 36.7% were resistant to clarithromycin, 77.3% to metronidazole, 16.6% to levofloxacin, and 0.3% to amoxicillin. No strains were detected to be resistant to furazolidone or tetracycline. During the 8-year study period, resistance to clarithromycin and metronidazole showed a significant upward trend, while the resistance pattern of the other antibiotics demonstrated a slight but nonsignificant fluctuation. Significant regional differences were found in the distribution of clarithromycin resistance among the northern (66.0%), southwestern (48.2%), and southeastern (34.6%) regions. The metronidazole resistance rate was significantly lower in the southeastern coastal region (76.3%) than in the other two regions (88.2% in the north and 87.7% in the southwest). Multi-drug resistance for two or more antibiotics was detected in 36.3% of the H. pylori strains, and the predominant multi-resistance pattern was the dual resistance to clarithromycin and metronidazole.

CONCLUSIONS

The prevalence of H. pylori resistance to clarithromycin and metronidazole is rather high in Chinese children and has been increasing over time. A relatively high resistance rate to levofloxacin was also noticed in children, while almost all strains were susceptible to amoxicillin, furazolidone, and tetracycline. It will be of great clinical significance to continuously monitor the antibiotic-resistance patterns of H. pylori in the pediatric population.

Promising anti-Helicobacter pylori and anti-inflammatory metabolites from unused parts of Phoenix dactylifera CV 'Zaghloul': in vitro and in silico study

CONTEXT

Date palm waste is an agricultural waste that accumulates in massive amounts causing serious pollution and environmental problems.

OBJECTIVES

Date palm trees, Phoenix dactylifera Linn CV 'Zaghloul' (Arecaceae) grown in Egypt, leave behind waste products that were investigated to produce compounds with anti-Helicobacter pylori and anti-inflammatory activities.

MATERIALS AND METHODS

Chromatographic workup of P. dactylifera aqueous methanol extract derived from fibrous mesh and fruit bunch (without fruit) afforded a new sesquiterpene lactone derivative, phodactolide A (1), along with ten known compounds (2-11), primarily identified as polyphenols. Chemical structures were unambiguously elucidated based on mass and 1D/2D NMR spectroscopy. All isolated compounds were assessed for their activities against H. pylori using broth micro-well dilution method and clarithromycin as a positive control. The anti-inflammatory response of isolated compounds was evaluated by inhibiting cyclooxygenase-2 enzyme using TMPD Assay followed by an in silico study to validate their mechanism of action using celecoxib as a standard drug.

RESULTS

Compounds 4, 6 and 8-10 exhibited potent anti-H. pylori activity with MIC values ranging from 0.48 to 1.95 µg/mL that were comparable to or more potent than clarithromycin. For COX-2 inhibitory assay, 4, 7 and 8 revealed promising activities with IC₅₀ values of 1.04, 0.65 and 0.45 μg/mL, respectively. These results were verified by molecular docking studies, where 4, 7 and 8 showed the best interactions with key amino acid residues of COX-2 active site.

CONCLUSION

The present study characterizes a new sesquiterpene lactone and recommends 4 and 8 for future in vivo studies as plausible anti-ulcer remedies.

Simultaneous determination of macrolides in water samples by solid-phase extraction and capillary electrophoresis

Solid-phase extraction (SPE) coupled with capillary electrophoresis (CE) for the determination of macrolide antibiotics (azithromycin, clarithromycin, roxithromycin, tylosin) and tiamulin in water samples was described in this article. These compounds were extracted with different types of sorbents ( Oasis HLB, C18, C8, SDB, and Strata-X) and different masses of sorbents (60 mg, 200 mg, and 500 mg) using different organic solvents (methanol, ethanol, and acetonitrile) and different pH values of water samples (pH 7.00, 8.00, and 9.00). It was found that the highest extraction efficiency of the studied compounds was obtained with 200 mg/3 mL C18 cartridges with methanol as eluent at pH 9.00 of the water sample. The developed SPE-CE method for macrolide antibiotics and tiamulin was validated for linearity, precision, repeatability, the limit of detection (LOD), the limit of quantification (LOQ), and recovery. Good linearity was obtained in the range of 0.3-30 mg L-1 depending on the drug, with correlation coefficients higher than 0.9958 in all cases except clarithromycin (0.9873). Expanded measurement uncertainties were calculated for each pharmaceutical, accounting for 20.31 % (azithromycin), 38.33 % (tiamulin), 28.95 % (clarithromycin), 26.99 % (roxithromycin), and 21.09 % (tiamulin). Uncertainties associated with precision and calibration curves contributed the most to the combined measurement uncertainty. The method was successfully applied to the analysis of production waste-water from the pharmaceutical industry.

Molecular Identification of Strains within the Mycobacterium abscessus Complex and Determination of Resistance to Macrolides and Aminoglycosides

One of the most relevant and pathogenic groups among the rapidly growing mycobacteria (RGM) is Mycobacterium abscessus complex (MABC) that includes three subspecies: M. abscessus subsp. abscessus, M. abscessus subsp. bolletii, and M. abscessus subsp. massiliense. The aim of this study was the analysis of prevalence of MABC among other non-tuberculous mycobacteria isolated from patients in the Malopolska Region of Poland, between 2018 and 2021, as well as determination of their subspecies and molecular mechanisms of resistance to macrolides and aminoglycosides. The incidence of MABC was 5,4% (12/223). Eight strains were classified as M. abscessus subsp. abscessus, three as M. abscessus subsp. massiliense and one M. abscessus subsp. bolletii. Molecular analysis showed resistance to macrolides for eight strains of M. abscessus subsp. abscessus associated with erm(41)T28 gene mutations. One strain of M. abscessus subsp. abscessus showed resistance to macrolides (two mutations simultaneously: in erm(41)T28 and rrl genes) and aminoglycosides (point mutation in rrs gene). One strain of M. abscessus subs. bolletii was resistant to macrolides (erm(41)T28 mutation), whereas presented no mutations for aminoglycosides. M. abscessus subsp. massiliense reveal no mutations. High clarithromycin resistance of M. abscessus, determines the urgent need for susceptibility-based treatment. Molecular determination of resistance mechanisms to aminoglycosides and macrolides enables fast and accurate targeted treatment implementation.

Molecular characterization of Helicobacter pylori isolated from Nile Tilapia (Oreochromis niloticus) and fish handlers

BACKGROUND

Helicobacter pylori is a worldwide pathogen that affects both animals and humans with a wide environmental distribution, causing serious health problems in humans. This research has timely addressed the topic of new sources of H. pylori infection, which is currently a global issue, especially in developing countries. For this purpose, 115 Tilapia fish, 50 freshwater samples, and 88 fish-handlers' stool samples were investigated for the presence of H. pylori in Qena Governorate, Egypt. The applied techniques were antigen screening tests, culturing, and molecular methods through ureC gene amplification, and 16 S rRNA characterization.

RESULTS

Helicobacter pylori was detected in 7.83%, 14%, 4.35%, and 12% of the investigated fish and water samples by culture and PCR methods, respectively. Out of the total studied participants, 40 tested positive for H. pylori when screened by stool antigen test, of which 35 (39.77%), and 31 (35.23%) were confirmed by conventional and molecular techniques, respectively. The Fisher's exact test has shown a statistically significant correlation between H. pylori infection, sex, and age as risk factors, while the association was insignificant concerning the residence. Males contracted the infection at a higher rate than females (48.08% and 16.67%, respectively). Also, H. pylori infection rate was the highest among fish-handlers aged 36-45 years old (46.67%), followed by the 26-35 years old age group (39.53%). With regard to the residence, a higher occurrence rate was recorded in the rural (36.07%) than the urban population (33.33%). Helicobacter pylori isolates harbored the highest antimicrobial resistance against ampicillin (100%), metronidazole (95.24%), while the least antimicrobial resistance was recorded against levofloxacin (21.43%), and clarithromycin (26.20%). The phylogenetic analysis revealed a high degree of homology between the isolates selected from Tilapia fish, freshwater, and fish-handlers.

CONCLUSIONS

Our data emphasized the role that fish and freshwater play in disseminating H. pylori infection as one of the diseases that has a significant public health issue.

The epidemiology of Helicobacter pylori resistance in a university affiliated hospital: a comparison between two time periods-a cross-sectional design

PURPOSE

During the last few decades, the increased use of various types of antibiotics in the general population caused a significant change in regional Helicobacter pylori (H. pylori) antibiotic resistance. Our aim is to study the changes in H. pylori resistance in patients who had undergone an esophagogastroduodenoscopy (EGD) and susceptibility testing and found positive for H. pylori. The study was conducted in a university affiliated hospital between 2013-2020.

METHODS

A cross-sectional study was performed on all consecutive patients who had undergone an EGD and tested positive for H. pylori at the Kaplan Medical Center, Israel. The study period was divided into two sub-periods: 2013-2016 and 2017-2020. Data on age, sex, comorbidities, previous treatments, and antimicrobial susceptibility testing for six antimicrobial agents were compared.

RESULTS

The resistance rates of H. pylori to clarithromycin and dual resistance to clarithromycin and metronidazole were found significantly higher during the late period. Multivariable analysis showed that the later period, older age, and diabetes mellitus were independent predictors for antimicrobial resistance.

CONCLUSIONS

Our study has shown that there is an increasing resistance of H. pylori to clarithromycin and metronidazole while its susceptibility is unaffected with time to other antibiotics. More recent cross-sectional studies with larger samples are warranted in order to evaluate the changes in the resistance patterns of H. pylori to various antibiotics with time.

Development and validation of high-performance liquid chromatography method for determination of clarithromycin in pharmaceutical tablets

Clarithromycin is a very important macrolide antibiotic used to treat bacterial infections in human and veterinary medicine. This study reports the development and validation of cost-effective, simple, precise, accurate, and robust high-performance liquid chromatography (HPLC) for the determination of clarithromycin (CLA) in tablets. Reversed-phase chromatography was conducted using a standard column at 55°C with ultraviolet detection at 215 nm. A mobile phase consisting of acetonitrile -2-methyl-2-propanol -potassium phosphate buffer was used at a flow rate of 1.0 mL/min. The proposed method displayed good linearity, precision, accuracy, robustness, and specificity. The present HPLC was compared with capillary electrophoresis and bioassay methods and the results indicated that there was no significant difference between these methods. Moreover, the obtained results demonstrated the validity of the isocratic HPLC, which allows reliable quantitation of CLA in pharmaceutical samples. Thus, it can be used as a substitute alternative methodology for the routine quality control of this medicine, in situations where other methods are less accessible in the laboratory.

The neurobehavioral impacts of typical antibiotics toward zebrafish larvae

Due to the widely usage in livestock, aquaculture and clinics, antibiotic residues are existed in aqueous environments and their potential toxicity to aquatic organisms is concerning. Here, we used zebrafish as the model to investigate the neurotoxicity and involved mechanism of seven antibiotics that were frequently detected in surface waters. The results revealed that the short-term exposure to clarithromycin (CLA), chlortetracycline (CTC) and roxithromycin (ROX) induced behavioral effects, with effective concentration of 1 μg/L (CTC and ROX) and 100 μg/L (CLA, CTC and ROX) respectively. A significant decrease in the travel distance and velocity as well as an increase in turn angle was measured. TUNEL assay identified increased cell apoptosis in brain sections of larvae exposed to three neurotoxic antibiotics, which raised the possibility that the behavioral symptoms were associated with neural damage. Transcriptome sequencing showed that the three antibiotics could affect the nervous system of zebrafish including the alteration of synaptogenesis and neurotransmission. Additionally, ROX and CTC affected pathways involved in mitochondrial stress response and endocrine system in zebrafish larvae. Besides, BDNF, ASCL1, and CREBBP are potential upstream regulatory factors that mediated these impacts. These findings indicated that exposure of CTC, ROX and CLA may cause abnormal behavior toward zebrafish larvae under environmental relevant concentration and revealed the potential role of neural cell apoptosis and synaptogenesis signaling in mediating this effect.

Helicobacter pylori Antimicrobial Resistance Using Next-Generation Sequencing in Stool Samples in a Pediatric Population

Helicobacter pylori ( H pylori ) eradication rates have declined globally, stressing the importance of antimicrobial susceptibility testing to inform treatment. Molecular tests such as next-generation sequencing (NGS) provide susceptibility data for the antibiotics used in the treatment of H pylori in a noninvasive, effective, and rapid manner. We obtained stool susceptibility testing using a novel NGS-based analysis and compared results with the current "gold standard" of gastric biopsy culture via agar dilution in 20 pediatric patients with evidence of H pylori in gastric biopsies. Stool NGS-based antimicrobial susceptibility analysis was highly concordant with agar dilution for no resistance (100% agreement), as well as clarithromycin, levofloxacin, and amoxicillin resistance (100%, 67%, and 100% agreement, respectively) but not concordant for metronidazole in our cohort of patients. Future studies involving a larger number of patients and geographical regions are needed to further validate this analysis.

Rapid changes of mRNA expressions of cardiac ion channels affected by Torsadogenic drugs influence susceptibility of rat hearts to arrhythmias induced by Beta-Adrenergic stimulation

Drug-induced long QT syndrome (LQTS) and Torsades de Pointes (TdP) are serious concerns in drug development. Although rats are a useful scientific tool, their hearts, unlike larger species, usually do not respond to torsadogenic drugs. Consequently, their resistance to drug-induced arrhythmias is poorly understood. Here, we challenged rats with rapid delayed rectifier current (Ikr)-inhibiting antibiotic clarithromycin (CLA), loop diuretic furosemide (FUR) or their combination (CLA + FUR), and examined functional and molecular abnormalities after stimulation with isoproterenol. Clarithromycin and furosemide were administered orally at 12-h intervals for 7 days. To evaluate electrical instability, electrocardiography (ECG) was recorded either in vivo or ex vivo using the Langendorff-perfused heart method under basal conditions and subsequently under beta-adrenergic stimulation. Gene expression was measured using real-time quantitative PCR in left ventricular tissue. Indeed, FUR and CLA + FUR rats exhibited hypokalemia. CLA and CLA + FUR treatment resulted in drug-induced LQTS and even an episode of TdP in one CLA + FUR rat. The combined treatment dysregulated gene expression of several ion channels subunits, including KCNQ1, calcium channels and Na+/K + -ATPase subunits, while both monotherapies had no impact. The rat with recorded TdP exhibited differences in the expression of ion channel genes compared to the rest of rats within the CLA + FUR group. The ECG changes were not detected in isolated perfused hearts. Hence, we report rapid orchestration of ion channel reprogramming of hearts with QT prolongation induced by simultaneous administration of clarithromycin and furosemide in rats, which may account for their ability to avoid arrhythmias triggered by beta-adrenergic stimulation.

Impact of Heterotropic Allosteric Modulation on the Time-Dependent Inhibition of Cytochrome P450 3A4

The current study was designed to investigate the influence of allosteric effectors on the metabolism of the prototypical cytochrome P450 (CYP) 3A4 substrate midazolam (MDZ), and on the determination in vitro time-dependent inhibition (TDI) of CYP3A4 using human liver microsomes (HLM). As the concentration of midazolam increased to 250 µM in HLMs, homotropic cooperativity resulted in a decrease in the 1'-hydroxymidazolam to 4-hydroxymidazolam ratio to a maximum of 1.1. The presence of varying concentrations of testosterone, progesterone (PGS), or carbamazepine (CBZ) in HLMs with MDZ could recapitulate the effect of homotropic cooperativity such that the formation rates of the 1'hydroxymidazolam and 4-hydroxymidazolam were equal even at low concentrations of MDZ. The presence of PGS (10 or 100 µM) and CBZ (100 or 1000 µM) in in vitro TDI determination of four known CYP3A4 time-dependent inactivators (clarithromycin, troleandomycin, mibefradil, raloxifene) simultaneously decreased potency and inactivation rate constant, resulting in fold changes in inactivation efficiency on average of 1.6-fold and 13-fold for the low and high concentrations of allosteric modulator tested, respectively. The formation of a metabolic-intermediate complex (MIC) for clarithromycin and troleandomycin decreased in the presence of the allosteric modulators in a concentration-dependent manner, reaching a new steady state formation that could not be overcome with increased incubation time. Maximum reduction of the MIC formed by clarithromycin was up to ∼91%, while troleandomycin MIC decreased up to ∼31%. These findings suggest that the absence of endogenous allosteric modulators may contribute to the poor translation of HLM-based drug-drug interaction predictions. SIGNIFICANCE STATEMENT: The reported overprediction of in vitro human liver microsome time-dependent inhibition of CYP3A4 and observed drug interactions in vivo remains an issue in drug development. We provide characterization of allosteric modulators on the CYP3A4 metabolism of the prototypical substrate midazolam, demonstrating the ability of the modulators to recapitulate the homotropic cooperativity of midazolam. Furthermore, we demonstrate that allosteric heterotropic cooperativity of CYP3A4 can impact the time-dependent inhibition kinetics of known mechanisms-based inhibitors, providing a potential mechanism to explain the overprediction.

A systemic review of Mycobacterium nebraskense case reports up to october 2023, featuring our unique case study

Background

Mycobacterium nebraskense is a rare, slow growing nontuberculous mycobacterium species with limited documented cases. This systematic review aims to comprehensively analyze the clinical characteristics, presentation, and management of M. nebraskense infections by analyzing the available literature, including a newly reported case that we present in this article.

Methods

A comprehensive search was conducted using PubMed and Google Scholar to identify relevant cases up to October 2023. Only seven reported cases were found, highlighting the scarcity of information on this pathogen.

Results

Our analysis revealed several key findings. First, gender disparities were observed, with females being more susceptible to M. nebraskense infections. Additionally, a significant portion of patients presented with asymptomatic infections. Most affected individuals were over the age of 60, emphasizing potential age-related susceptibility. Comorbidity profiles varied widely among cases, and patients with preexisting lung comorbidities were at an increased risk of infection. The decision to treat or observe depended on clinical presentation, with even immunosuppressed individuals not always requiring treatment. Regarding treatment, we proposed an empirical approach with amikacin, clarithromycin, or rifabutin, considering the reported resistance to doxycycline and minocycline. Combination therapy was commonly employed to minimize resistance development, consistent with mycobacterial infection management.

Conclusion

This study underscores the need for further research to validate these findings and enhance our understanding of M. nebraskense infections. As limited data are available, this review aims to provide valuable insights into a rare and emerging pathogen to guide clinical practice and future research endeavors.

Clinical characteristics and drug susceptibility profiles of Mycobacterium abscessus complex infection at a medical school in Thailand

OBJECTIVES

This study investigated the differences in epidemiological and clinical data, and antimicrobial susceptibilities among different subspecies of Mycobacterium abscessus complex (MABSC) clinical isolates at a medical school in Thailand.

METHODS

A total of 143 MABSC clinical isolates recovered from 74 patients were genotypically analyzed for erm(41), rrl, and rrs mutations, and antimicrobial susceptibilities were determined using a broth microdilution method. Patient characteristics and clinical outcomes were reviewed from the medical records.

RESULTS

Seventy-four patients were infected with 28/74 (37.8%) M. abscessus subspecies abscessus (MAB), 43/74 (58.1%) M. abscessus subsp. massiliense (MMA), and 3/74 (4.1%) M. abscessus subsp. bolletii (MBO). The clinical findings and outcomes were generally indistinguishable between the three subspecies. All three subspecies of MABSC clinical isolates exhibited high resistance rates to ciprofloxacin, doxycycline, moxifloxacin, TMP/SMX, and tobramycin. MAB had the highest resistance rates to clarithromycin (27.8%, 20/72) and amikacin (6.9%, 5/72) compared to MBO and MMA, with p < 0.001 and p = 0.004, respectively. In addition, the rough morphotype was significantly associated with resistance to amikacin (8.9%, 5/56), clarithromycin (26.8%, 15/56), and imipenem (76.8%, 43/56) (p < 0.001), whereas the smooth morphotype was resistant to linezolid (57.1%, 48/84) (p = 0.002). In addition, T28 of erm(41), rrl (A2058C/G and A2059C/G), and rrs (A1408G) mutations were detected in 87.4% (125/143), 16.1% (23/143), and 9.1% (13/143) of MABSC isolates, respectively.

CONCLUSIONS

Three MABSC subspecies caused a variety of infections in patients with different underlying comorbidities. The drug susceptibility patterns of the recent circulating MABSC strains in Thailand were different among the three MABSC subspecies and two morphotypes.

Efficacy and Tolerability of 14-Day Tegoprazan- versus Rabeprazole-Based Triple Therapy for Eradication of Helicobacter pylori: A Real-World Evidence Study

Background/Aims

Tegoprazan, a new, fast, and strong potassium-competitive acid blocker, has been approved for the treatment of gastric acid-related diseases in Korea. However, real-world clinical data regarding this drug are scarce. We aimed to compare the Helicobacter pylori eradication rates of tegoprazan- and rabeprazole-based triple therapy.

Methods

We retrospectively reviewed data from patients who received first-line treatment for H. pylori infection using tegoprazan- or rabeprazole-based triple therapy for 2 weeks (50 mg tegoprazan or 20 mg rabeprazole+1,000 mg amoxicillin+500 mg clarithromycin twice daily). The primary endpoint was the eradication rate as determined by intention-to-treat analysis.

Results

Of the 677 patients included in our study, 344 and 333 received tegoprazan-based and rabeprazole-based triple therapy, respectively. The eradication rate from intention-to-treat analysis was 76.7% (95% confidence interval [CI], 72.1% to 81.0%) for tegoprazan-based triple therapy and 75.4% (95% CI, 70.5% to 79.8%) for rabeprazole-based triple therapy. There was no significant difference in the eradication rates between the two groups (p>0.999). Per-protocol analysis also revealed no significant difference between the eradication rates of the two groups (tegoprazan 83.4% [95% CI, 79.0% to 87.2%] vs rabeprazole 83.5% [79.0% to 87.4%], p>0.999). Furthermore, there was no significant difference in adverse event rates between the two groups (tegoprazan, 27.6%; rabeprazole, 25.8%; p=0.604).

Conclusions

The eradication rate of tegoprazan-based triple therapy was similar to that of rabeprazole-based triple therapy. Further studies on the dose-escalation effect of tegoprazan for H. pylori eradication and the efficacy of tegoprazan in regimens other than conventional triple therapy are needed.

Optimizing Helicobacter pylori Treatment: An Updated Review of Empirical and Susceptibility Test-Based Treatments

As the rate of discovery of drug-resistant Helicobacter pylori cases increases worldwide, the relevant societies have updated their guidelines for primary eradication regimens. A promising strategy against drug-resistant H. pylori is tailored therapy based on the results of an antibiotic susceptibility test; however, it is difficult to apply this strategy to all cases. Although culture-based antibiotic susceptibility tests can assess resistance to any antimicrobial agent, their greatest disadvantage is the time required to draw a conclusion. In contrast, molecular-based methods, such as polymerase chain reaction, can rapidly determine the presence of resistance, although a single test can only test for one type of antimicrobial agent. Additionally, the limited availability of facilities for molecular-based methods has hindered their widespread use. Therefore, low-cost, minimally invasive, simple, and effective primary regimens are needed. Several studies have compared the efficacy of the latest primary eradication regimens against that of tailored therapies, and their results have shaped guidelines. This article reviews the latest research on empirical and tailored treatments for H. pylori infections. Evidence for the superiority of tailored therapy over empirical therapy is still limited and varies by region and treatment regimen. A network meta-analysis comparing different empirical treatment regimens showed that vonoprazan triple therapy provides a superior eradication effect. Recently, favorable results towards vonoprazan dual therapy have been reported, as it reached eradication levels similar to those of vonoprazan triple therapy. Both vonoprazan dual therapy and tailored therapy based on antibiotic susceptibility tests could contribute to future treatment strategies.

Clarithromycin as soil and environmental pollutant: Adsorption-desorption processes and influence of pH

Antibiotics pollution is a growing environmental issue, as high amounts of these compounds are found in soil, water and sediments. This work studies the adsorption/desorption of the macrolide antibiotic clarithromycin (CLA) for 17 agricultural soils with different edaphic characteristics. The research was carried out using batch-type experiments, with an additional assessment of the specific influence of pH for 6 of the soils. The results show that CLA adsorption reaches between 26 and 95%. In addition, the fit of the experimental data to adsorption models provided values between 1.9 and 19.7 Ln μmol1-n kg-1 for the KF, Freundlich affinity coefficient, and between 2.5 and 10.5 L kg-1 for Kd, distribution constant of Linear model. Regarding the linearity index, n, it varied between 0.56 and 1.34. Desorption showed lower scores than adsorption, with an average of 20%, and with values of 3.1 and 93.0 Ln μmol1-n kg-1 for KF(des) and 4.4 and 95.0 L kg-1 for Kd(des). The edaphic characteristics with the highest influence on adsorption were the silt fraction content and the exchangeable Ca content, while in the case of desorption, they were the total nitrogen, organic carbon, and exchangeable Ca and Mg contents. Regarding the pH, within the range studied (between 3 and 10), its value did not decisively affect the adsorption/desorption process. Overall, the set of these results could be of help to program appropriate measures leading to the retention/elimination of this antibiotic when it reaches the environment as a pollutant.

Genomic Analyses of Longitudinal Mycobacterium abscessus Isolates in a Multicenter Cohort Reveal Parallel Signatures of In-Host Adaptation

BACKGROUND

Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and an increasingly frequent cause of opportunistic infections. Mycobacterium abscessus complex (MABC) is one of the major NTM lung pathogens that disproportionately colonize and infect the lungs of individuals with cystic fibrosis (CF). MABC infection can persist for years, and antimicrobial treatment is frequently ineffective.

METHODS

We sequenced the genomes of 175 isolates longitudinally collected from 30 patients with MABC lung infection. We contextualized our cohort amidst the broader MABC phylogeny and investigated genes undergoing parallel adaptation across patients. Finally, we tested the phenotypic consequences of parallel mutations by conducting antimicrobial resistance and mercury-resistance assays.

RESULTS

We identified highly related isolate pairs across hospital centers with low likelihood of transmission. We further annotated nonrandom parallel mutations in 22 genes and demonstrated altered macrolide susceptibility co-occurring with a nonsynonymous whiB1 mutation. Finally, we highlighted a 23-kb mercury-resistance plasmid whose loss during chronic infection conferred phenotypic susceptibility to organic and nonorganic mercury compounds.

CONCLUSIONS

We characterized parallel genomic processes through which MABC is adapting to promote survival within the host. The within-lineage polymorphisms we observed have phenotypic effects, potentially benefiting fitness in the host at the putative detriment of environmental survival.

Human footprint on the water quality from the northern Antarctic Peninsula region

This study assessed the human footprint on the chemical pollution of Antarctic waters by characterizing inorganic chemicals and selected organic anthropogenic contaminants of emerging concern (CECs) in inland freshwater and coastal seawater and the associated ecotoxicological risk. Nicotine and tolytriazole, present in 74% and 89% of the samples analyzed, respectively, were the most ubiquitous CECs in the investigated area. The most abundant CECs were citalopram, clarithromycin, and nicotine with concentrations reaching 292, 173, and 146 ng/L, respectively. The spatial distribution of CECs was not linked to any water characteristic or inorganic component. The contamination pattern by CECs in inland freshwater varied among locations, whereas it was very similar in coastal seawater. This suggests that concentrations in inland freshwater may be ruled by environmental processes (reemission from ice, atmospheric deposition, limited photo- and biodegradation processes, etc.) in addition to human activities. Following risk assessment, citalopram, clarithromycin, nicotine, venlafaxine, and hydrochlorothiazide should be considered of concern in this area, and hence, included in future monitoring of Antarctic waters and biota. This work provides evidence on the fact that current measures taken to protect the pristine environment of Antarctica from human activities are not effective to avoid CEC spread in its aquatic environment.

Cumulative antimicrobial susceptibilities for respiratory clinical isolates of Mycobacterium avium Complex, Mycobacterium kansasii, and Mycobacterium abscessus from Pakistan 2018 to 2022

Background

Nontuberculous mycobacteria (NTM) are increasingly identified as causes of protracted pulmonary infections. Antibiotic susceptibility testing requires microdilution methods, which are often unavailable in laboratories in resource-poor settings. We report cumulative antibiograms for the most frequently isolated clinical pulmonary NTM from Pakistan to inform empiric antibiotic management of initial NTM infections.

Methods

We analyzed data from 2018 to 2022 for the most frequently isolated and clinically relevant NTM isolated from respiratory specimens, i.e., Mycobacterium avium complex (MAC), Mycobacterium abscessus group (MAG), and Mycobacterium kansasii (MK). Antibiograms were developed using the Clinical Laboratory Standards Institute's M39ED5 standard. Percentage susceptibilities and 95% confidence intervals (CI) were calculated.

Results

Over 4 years, 529 NTM, comprising 209 MAC, 249 MAG, and 71 MK were analyzed. For MAC and MAG, where clarithromycin (CLR)-based regimens are recommended, CLR was active for 94.8% (95% CI 91.3-96.9), and 77.5% (95% CI 71.4-82.7) isolates, respectively. Combination regimens comprising 3 active drugs CLR + linezolid (LZD) + moxifloxacin for MAC and CLR + LZD + Amikacin for MAG had 98.4% (95% CI 95.9-99.4) and 68.9% (95% CI 62.3-74.8) coverage for pulmonary disease, respectively. For MK, 91.5% (95% CI 82.8-96.1) isolates were susceptible to rifampin (RIF), with a combination of RIF + CLR covering 88.7% (95% CI 79.3-94.2) of MK pulmonary infections, respectively.

Conclusions

These data can inform empiric treatment guidance for the most common NTM pulmonary infections, i.e., for MAC, MAG, and MK disease in Pakistan.

Subspecies Distribution and Antimicrobial Susceptibility Testing of Mycobacterium abscessus Clinical Isolates in Madrid, Spain: a Retrospective Multicenter Study

Mycobacterium abscessus (MABS) is the most pathogenic and drug-resistant rapidly growing mycobacteria. However, studies on MABS epidemiology, especially those focusing on subspecies level, are scarce. We aimed to determine MABS subspecies distribution and its correlation with phenotypic and genotypic antibiotic profiles. A retrospective multicenter study of 96 clinical MABS isolates in Madrid between 2016 to 2021 was conducted. Identification at the subspecies level and resistance to macrolides and aminoglycosides were performed by the GenoType NTM-DR assay. The MICs of 11 antimicrobials tested against MABS isolates were determined using the broth microdilution method (RAPMYCOI Sensititer titration plates). Clinical isolates included 50 (52.1%) MABS subsp. abscessus; 33 (34.4%) MABS subsp. massiliense; and 13 (13.5%) MABS subsp. bolletii. The lowest resistance rates corresponded to amikacin (2.1%), linezolid (6.3%), cefoxitin (7.3%), and imipenem (14.6%), and the highest to doxycycline (100.0%), ciprofloxacin (89.6%), moxifloxacin (82.3%), cotrimoxazole (82.3%), tobramycin (81.3%), and clarithromycin (50.0% at day 14 of incubation). Regarding tigecycline, although there are no susceptibility breakpoints, all strains but one showed MICs ≤ 1 μg/mL. Four isolates harbored mutations at positions 2058/9 of the rrl gene, one strain harbored a mutation at position 1408 of the rrl gene, and 18/50 harbored the T28C substitution at erm(41) gene. Agreement of the GenoType results with clarithromycin and amikacin susceptibility testing was 99.0% (95/96). The rate of MABS isolates showed an upward trend during the study period, being M. abscessus subsp. abscessus the most frequently isolated subspecies. Amikacin, cefoxitin, linezolid, and imipenem showed great in vitro activity. The GenoType NTM-DR assay provides a reliable and complementary tool to broth microdilution for drug resistance detection. IMPORTANCE Infections caused by Mycobacterium abscessus (MABS) are increasingly being reported worldwide. Identifying MABS subspecies and assessing their phenotypic resistance profiles are crucial for optimal management and better patient outcomes. M. abscessus subspecies differ in erm(41) gene functionality, which is a critical determinant of macrolide resistance. Additionally, resistance profiles of MABS and the subspecies distribution can vary geographically, highlighting the importance of understanding local epidemiology and resistance patterns. This study provides valuable insights into the epidemiology and resistance patterns of MABS and its subspecies in Madrid. Elevated resistance rates were observed for several recommended antimicrobials, emphasizing the need for cautious drug use. Furthermore, we assessed the GenoType NTM-DR assay, which examines principal mutations in macrolides and aminoglycosides resistance-related genes. We observed a high level of agreement between the GenoType NTM-DR assay and the microdilution method, indicating its usefulness as an initial tool for early initiation of appropriate therapy.

Safety and effectiveness of vonoprazan-based rescue therapy for Helicobacter pylori infection

BACKGROUND

Vonoprazan (VPZ)-based regimens are an effective first-line therapy for Helicobacter pylori (H. pylori) infection. However, their value as a rescue therapy needs to be explored.

AIM

To assess a VPZ-based regimen as H. pylori rescue therapy.

METHODS

This prospective, single-center, clinical trial was conducted between January and August 2022. Patients with a history of H. pylori treatment failure were administered 20 mg VPZ twice daily, 750 mg amoxicillin 3 times daily, and 250 mg Saccharomyces boulardii (S. boulardii) twice daily for 14 d (14-d VAS regimen). VPZ and S. boulardii were taken before meals, while amoxicillin was taken after meals. Within 3 d after the end of eradication therapy, all patients were asked to fill in a questionnaire to assess any adverse events they may have experienced. At least 4-6 wk after the end of eradication therapy, eradication success was assessed using a ¹³C-urea breath test, and factors associated with eradication success were explored.

RESULTS

Herein, 103 patients were assessed, and 68 patients were finally included. All included patients had 1-3 previous eradication failures. The overall eradication rates calculated using intention-to-treat and per-protocol analyses were 92.6% (63/68) and 92.3% (60/65), respectively. The eradication rate did not differ with the number of treatment failures (P = 0.433). The rates of clarithromycin, metronidazole, and levofloxacin resistance were 91.3% (21/23), 100.0% (23/23), and 60.9% (14/23), respectively. There were no cases of resistance to tetracycline, amoxicillin, or furazolidone. In 60.9% (14/23) patients, the H. pylori isolate was resistant to all 3 antibiotics (clarithromycin, metronidazole, and levofloxacin); however, eradication was achieved in 92.9% (13/14) patients. All patients showed metronidazole resistance, and had an eradication rate of 91.3% (21/23). The eradication rate was higher among patients without anxiety (96.8%) than among patients with anxiety (60.0%, P = 0.025). No severe adverse events occurred; most adverse events were mild and disappeared without intervention. Good compliance was seen in 95.6% (65/68) patients. Serological examination showed no significant changes in liver and kidney function.

CONCLUSION

VAS is a safe and effective rescue therapy, with an acceptable eradication rate (> 90%), regardless of the number of prior treatment failures. Anxiety may be associated with eradication failure.

Distribution and risk assessment of antibiotics under water level fluctuation in the riparian zone of the Hanjiang River

The riparian zone (RZ) is an important region connecting surface water and groundwater, and it has widely been acknowledged for its pollutant buffering capacity. However, the decontaminating effect of RZ on trace organic compounds such as antibiotics has received little attention. This study explored the distribution of 21 antibiotics and 4 sulfonamide metabolites in river water and groundwater in the lower reaches of the Hanjiang River. The diffusion and exchange of contaminants between the river and riverbanks under the influence of water conservancy projects (Xinglong Dam and the Yangtze-Hanjiang Water Diversion Project) were investigated. Macrolide antibiotics were prevalent in river water (62.5-100%) and groundwater samples (42.9-80.4%). Ofloxacin and chlortetracycline were detected with the highest concentrations in river water (12.2 ng L^-1) and groundwater (9.3 ng L^-1) respectively. Higher levels of antibiotics were observed in spring and winter than in other seasons. The river-groundwater interaction has a certain interception effect on antibiotics, especially near riverbanks. Redox sensitive element Fe²⁺ showed significantly positive correlations with some tetracycline and macrolide antibiotics (p < 0.05), and thus the migration mechanism between Fe²⁺ and antibiotics under the condition of redox change should be investigated further. Environmental risks posed by antibiotics were assessed for algae, daphnids, and fish in surface water and groundwater. Only clarithromycin and chlortetracycline presented a medium risk to algae (0.1 < RQ < 1), and the rest presented low risk (RQ < 0.1). Nevertheless, the risk range may be further extended by interactions between groundwater and surface water. Accurate understanding of antibiotic transport in RZ is critical for developing management strategies aimed at reducing the pollution load on the watershed.

Seasonal analysis of commonly prescribed antibiotics in Istanbul city

Antibiotics are among the most common medicine groups since they are used to treat infectious diseases, as nutritional supplements in livestock breeding, and for preservation in the food industry. Turkey is among the highest antibiotic consumers in the world. In the present study, the most popular 14 antibiotics available in Turkey were monitored in one hospital sewage and two urban wastewater treatment plant influents and effluents seasonally in Istanbul province, the largest metropolitan center in Turkey. The present research aimed to develop a robust analytical method to determine 14 antibiotics, including six chemical groups, in environmental matrices which are considered significant antibiotic pollution sources, namely hospital sewage and urban wastewater. Solid-phase extraction (SPE) and UPLC-MS/MS analysis parameters included optimized column temperature, eluent, mobile phase, and flow rate. Three SPE cartridges were employed in recovery studies. The antibiotic recovery rates varied between 40 and 100%, and all analytes were identified within 3 min with UPLC-MS/MS under optimal conditions. It was determined that method detection limits (MDLs) varied between 0.07 and 2.72 µg/L for the antibiotics. In all seasons, the highest beta-lactam group antibiotic concentrations were identified in hospital sewage. The season with the greatest variety of antibiotics in urban wastewater was spring. Clarithromycin and ciprofloxacin were the antibiotics determined at the highest concentration in the influent and effluent of the wastewater treatment plant in all seasons. This study showed that the most widely used beta-lactam group antibiotics were found in high amounts in hospital sewage wastewater but in low concentrations in the treatment plants, and hence, it is seen that the degradability of beta-lactam group antibiotics was high. The presence of clarithromycin, ciprofloxacin, lincomycin, levofloxacin, and trimethoprim antibiotics in hospital sewage in higher amounts and also in inlet and outlet of wastewater treatment plants proves that those are resistant antibiotics.

Identifying antimicrobials and their metabolites in wastewater and surface water with effect-directed analysis

This study aimed to identify antimicrobial contaminants in the aquatic environment with effect-directed analysis. Wastewater influent, effluent, and surface water (up- and downstream of the discharge location) were sampled at two study sites. The samples were enriched, subjected to high-resolution fractionation, and the resulting 80 fractions were tested in an antibiotics bioassay. The resulting bioactive fractions guided the suspect and nontargeted identification strategy in the high-resolution mass spectrometry data that was recorded in parallel. Chemical features were annotated with reference databases, assessed on annotation quality, and assigned identification confidence levels. To identify antibiotic metabolites, Phase I metabolites were predicted in silico for over 500 antibiotics and included as a suspect list. Predicted retention times and fragmentation patterns reduced the number of annotations to consider for confirmation testing. Overall, the bioactivity of three fractions could be explained by the identified antibiotics (clarithromycin and azithromycin) and an antibiotic metabolite (14-OH(R) clarithromycin), explaining 78% of the bioactivity measured at one study site. The applied identification strategy successfully identified antibiotic metabolites in the aquatic environment, emphasizing the need to include the toxic effects of bioactive metabolites in environmental risk assessments.

Direct toxicity of six antibiotics on soil bacterial communities affected by the addition of bio-adsorbents

Reducing the toxicity caused by antibiotics on bacterial communities in the soil is one of the great challenges of this century. For this, the effectiveness of amending the soil with different bioadsorbents such as crushed mussel shell (CMS), pine bark (PB) and biomass ash (BA), as well as combinations of them (CMS + PB and PB + BA) was studied at different doses (0 g kg^-1 to 48 g kg^-1). Soil samples were spiked, separately, with increasing doses (0-2000 mg kg^-1) of cefuroxime (CMX), amoxicillin (AMX), clarithromycin (CLA), azithromycin (AZI), ciprofloxacin (CIP) and trimethoprim (TMP). Their toxicity on bacterial growth was estimated using the tritium-labeled leucine (³H) incorporation method. Toxicity was observed to behave differently depending on the antibiotic family and bioadsorbent, although in different magnitude and at different doses. The toxicity of β-lactams (AMX and CXM) was reduced by up to 54% when the highest doses of bio-adsorbents were added due to the increase in pH (CMS and BA) and carbon (PB) contribution. Macrolides (CLA and AZI) showed slight toxicity in un-amended soil samples, which increased by up to 65% with the addition of the bio-adsorbents. The toxicity of CIP (a fluoroquinolone) increased with the dose of the bio-adsorbents, reaching up to 20% compared with the control. Finally, the toxicity of TMP (a diaminopyrimidine) slightly increased with the dose of bio-adsorbents. The by-products that increase soil pH are those that showed the highest increases of CLA, AZI, CIP and TMP toxicities. These results could help to prevent/reduce environmental pollution caused by different kinds of antibiotics, selecting the most appropriated bio-adsorbents and doses.

Discovery of natural-product-derived sequanamycins as potent oral anti-tuberculosis agents

The emergence of drug-resistant tuberculosis has created an urgent need for new anti-tubercular agents. Here, we report the discovery of a series of macrolides called sequanamycins with outstanding in vitro and in vivo activity against Mycobacterium tuberculosis (Mtb). Sequanamycins are bacterial ribosome inhibitors that interact with the ribosome in a similar manner to classic macrolides like erythromycin and clarithromycin, but with binding characteristics that allow them to overcome the inherent macrolide resistance of Mtb. Structures of the ribosome with bound inhibitors were used to optimize sequanamycin to produce the advanced lead compound SEQ-9. SEQ-9 was efficacious in mouse models of acute and chronic TB as a single agent, and it demonstrated bactericidal activity in a murine TB infection model in combination with other TB drugs. These results support further investigation of this series as TB clinical candidates, with the potential for use in new regimens against drug-susceptible and drug-resistant TB.

Efficacy and safety of vonoprazan-based regimen for Helicobacter pylori eradication therapy in Japanese adolescents: a prospective multicenter study

BACKGROUND

Vonoprazan (VPZ)-based regimen for Helicobacter pylori (H. pylori) is safe and more efficacious than the proton pump inhibitor-based regimen mainly in adults. This study aimed to evaluate the efficacy and safety of a VPZ-based regimen for H. pylori eradication therapy in adolescents.

METHODS

An H. pylori screening and treatment longitudinal project for third-year junior high school students in Saga Prefecture began in 2016. Students who tested positive for both urine and stool tests received a VPZ-based regimen. On the checklist, students were asked for diarrhea, fever, abdominal pain, nausea, vomiting, urticaria, dysgeusia, or bloody stool occurrence during the therapy.

RESULTS

The longitudinal project for H. pylori screening and treatment among third-grade students in Saga Prefecture targeted 41,115 students from 2017 to 2021 and 836 as positive. Of the 645 students, 542 (84.0% in per protocol [PP] analysis and 73.6% in intention-to-treat [ITT] analysis) were successful in primary eradication therapy. The secondary eradication therapy was successful in 79 (96.3% in PP analysis and 76.7% in ITT analysis) of 82 students. In the primary eradication therapy, abdominal pain occurred in 164 (27.9%), diarrhea in 217 (36.9%), nausea or vomiting in 7 (1.2%), and urticaria in 13 (2.2%) students. In the secondary eradication therapy, abdominal pain occurred in 12 (19.4%) and diarrhea in 17 (27.4%) students. The eradication therapy of 5 students was interrupted due to adverse events only by primary eradication therapy.

CONCLUSIONS

VPZ-based regimen for H. pylori was efficacious and safe for adolescents, as in adults, for both primary and secondary eradication therapies.

Dispersive solid phase extraction of metronidazole and clarithromycin from human plasma using a β-cyclodextrin grafted polyethylene polymer composite

In this work, for the first time, a polymeric composite based on β-cyclodextrin grafted with polyethylene has been prepared through ball milling and used as an efficient sorbent for dispersive solid phase extraction of metronidazole and clarithromycin from plasma samples. The prepared sorbent was characterized using Fourier transform infrared spectrophotometry, X-ray diffraction, and scanning electron microscopy. In the extraction process, after precipitating the proteins, the sorbent was added into the sample solution, and the mixture was vortexed to facilitate and speed up the sorption of the analytes onto the sorbent surface. After centrifuging, the sorbent particles were contacted with methanol to elute the analytes under the vortexing process. After this step, an aliquot of the eluate was taken and injected into high-performance liquid chromatography-diode array detector for quantitative analysis. Under the optimum extraction conditions, the extraction recoveries for metronidazole and clarithromycin were 76 and 83%, respectively. The limits of detection were 2.6 and 2.2 ng/ml for metronidazole and clarithromycin, respectively. The repeatability of the offered approach, expressed as relative standard deviation, was equal to or less than 4.7%. Finally, the method was successfully applied to plasma samples of the patients treated with metronidazole and clarithromycin.

Estimating Sources, Fluxes, and Ecological Risks of Antibiotics in the Wuhan Section of the Yangtze River, China: A Year-Long Investigation

To our knowledge, ours is the first study to investigate the annual fluxes, environmental fate, and ecological risks of five categories of antibiotics from the Wuhan section of the Yangtze River (China). All the 24 antibiotics we tested for were detected in water, with total concentrations of 17.11-867.2 ng/L (mean: 63.69 ng/L), and 19 antibiotics were detected in sediment, at 0.02-287.7 ng/g (mean: 16.54 ng/g). Sulfonamides, amphenicols, and macrolides were the three most prominent antibiotic classes in water, and fluoroquinolones were the most prominent in sediment. Farming activities (animal husbandry and aquaculture) are proposed as the largest contributors to antibiotic pollution in the Wuhan section of the Yangtze River according to the Unmix model, followed by municipal wastewater and mixed sources. Higher pollution levels were observed downstream (combined discharge of these sources). Monthly monitoring data (12 months) were used to estimate antibiotic annual fluxes, with 101.5 t (uncertainty: 5.6%) in the Wuhan section of the Yangtze River. Risk assessments showed that erythromycin, clarithromycin, and azithromycin posed medium and high ecological risks and were found in 9%-35% and 1.8%-3.7% of all water samples, respectively; enrofloxacin, clarithromycin, azithromycin, florfenicol, and thiamphenicol posed medium resistance risks in 1.9%-16.7% of waters in the Wuhan section of the Yangtze River. Our results have filled data gaps on antibiotic sources, annual fluxes, and resistance risk in the Wuhan section of the Yangtze River and demonstrated the importance of further management of antibiotic use in the studied areas. Environ Toxicol Chem 2023;42:605-619. © 2022 SETAC.

Risk ranking of macrolide antibiotics - Release levels, resistance formation potential and ecological risk

Antibiotic resistance (AR) development in natural water bodies is a significant source of concern. Macrolide antibiotics in particular have been identified as pollutants of concern for AR development throughout the literature, as well as by state and international authorities. This study utilises a probabilistic model to examine the risk of AR development arising from human-use macrolide residues, utilising administration rates from Ireland as a case study. Stages modelled included level of administration, excretion, degradation in wastewater, removal in wastewater treatment, assuming conventional activated sludge (CAS) treatment, and dilution. Release estimates per day, as well as risk quotient values for antibiotic resistance development and ecological impact, are generated for erythromycin, clarithromycin, and azithromycin. In the modelled scenario in which conventional activated sludge treatment is utilised in wastewater treatment, this model ranks risk of resistance development for each antibiotic in the order clarithromycin > azithromycin > erythromycin, with mean risk quotient values of 0.50, 0.34 and 0.12, respectively. A membrane bioreactor scenario was also modelled, which reduced risk quotient values for all three macrolides by at least 50 %. Risk of ecological impact for each antibiotic was also examined, by comparing environmental concentrations predicted to safety limits based on toxicity data for cyanobacteria and other organisms from the literature, with azithromycin being identified as the macrolide of highest risk. This study compares and quantifies the risk of resistance development and ecological impact for a high-risk antibiotic group in the Irish context, and demonstrates the potential for risk reduction achieved by adoption of alternative (e.g. membrane bioreactor) technology.

Evaluation of ciprofloxacin (CIP) and clarithromycin (CLA) adsorption with weathered PVC microplastics

The sorption kinetics of two of the most frequently used antibiotics onto recycled (weathered) polyvinyl chloride (PVC) was investigated, using Freundlich and Langmuir isotherm models. Various experimental conditions were set, including pH, contact time, rotational speed, temperature, and initial concentration. The batch experimental results indicated that Freundlich model was better fitted than Langmuir (R²: 98.7 and 84.7, for CIP and CLA respectively). Maximum adsorption capacity is 45.9 mg/g and 22.0 mg/g for CIP and CLA, respectively. Enthalpy (ΔH), and entropy (ΔS) values were negative for CIP, indicating that the reaction was exothermic and spontaneous, respectively. It was vice versa for CLA. Field emission scanning electron microscope (FESEM) and Fourier transform infrared spectrometer (FT-IR) analysis confirmed the physical adsorption mechanism. The results demonstrated that the recycled PVC microplastic has a good capacity for adsorption for both antibiotics.

Rare finding of duodenal lymphangioma in a patient with Helicobacter pylori associated gastritis: A case report

RATIONALE

Lymphangiomas are lymphatic malformations most commonly found in the head, neck and axilla. Their incidence in gastrointestinal tract, especially duodenum is very rare. They are mostly congenital and are usually seen in children. Owing to their asymptomatic nature, these tumors are often diagnosed incidentally. Surgical resection is the definite treatment.

PATIENT CONCERNS

We represent a case of a 30-year-old male with duodenal lymphangioma with presentation of intermittent dyspepsia for 1 year, partially relieved by a proton pump inhibitor.

DIAGNOSES

Upon physical examination, there was mild tenderness observed in the epigastrium. The rest of the physical examination was unremarkable. His complete blood count report was unremarkable. Upon a negative stool for Helicobacter pylori antigen test, the patient underwent an esophagogastroduodenoscopy which revealed H pylori gastritis and a duodenal lymphangioma.

INTERVENTIONS

Patient was put on triple therapy (clarithromycin, amoxicillin and omeprazole) for 14 days and his symptoms improved. The lymphangioma was not resected owing to small size.

OUTCOMES

Patient was followed till 1 year and his symptoms had improved.

LESSONS

The case describes a correlation between H pylori gastritis and a duodenal lymphangioma. There is likely to be an association between the two and therefore, further studies are required to find out any relationship that may exist between the 2 conditions.

Antibiotics in the Basque coast (N Spain): Occurrence in waste and receiving waters, and risk assessment (2017-2020)

The study of the presence of antibiotics in the aquatic environment is a preliminary step to analyse their possible harmful effects on aquatic ecosystems. In order to monitor their occurrence in the aquatic environment, the European Commission established in 2015, 2018, and 2020 three Watch Lists of substances for Union-wide monitoring (Decisions (EU) 2015/495, 2018/840, and 2020/1161), where some antibiotics within the classes of macrolides, fluoroquinolones and penicillins were included. In the Basque coast, northern Spain, three macrolide antibiotics (erythromycin, clarithromycin, azithromycin) and ciprofloxacin were monitored quarterly from 2017 to 2020 (covering a period before and after the COVID19 outbreak), in water samples collected from two Waste Water Treatment Plants (WWTPs), and three control points associated with receiving waters (transitional and coastal water bodies). This work was undertaken for the Basque Water Agency (URA). The three macrolide antibiotics in water showed a frequency of quantification >65 % in the Basque coast, with higher concentrations in the WWTP emission stations than in receiving waters. Their frequency of quantification decreased from 2017 to 2020, as did the consumption of antibiotics in Spanish primary care since 2015. Ciprofloxacin showed higher frequencies of quantification in receiving waters than in wastewaters, but the highest concentrations were observed in the WWTP emission stations. Although consumption of fluoroquinolones (among which is ciprofloxacin) in primary care in the Basque Country has decreased in recent years, this trend was not observed in the waters sampled in the present study. On the other hand, concentrations of clarithromycin, azithromycin, and ciprofloxacin in receiving waters exceeded their respective Predicted No-Effect Concentrations, so they could pose an environmental risk. These substances are widely used in human and animal medicine, so, although only ciprofloxacin is included in the third Watch List, it would be advisable to continue monitoring macrolides in the Basque coast as well.

Clinical effect of Anwei Qingyou recipe on peptic ulcer and its effect on the levels of EGF and PGE2: A retrospective study

BACKGROUND

To investigate the effect of Anwei Qingyou formula on the clinical treatment of patients with peptic ulcer (PU) and its effect on the levels of epidermal growth factor (EGF) and prostaglandin E2 (PGE2).

METHODOLOGY

Medical records of 83 patients with PU, treated in our hospital from January 2020 to January 2021, were retrospectively analyzed. Among them, 40 patients received conventional triple therapy (scheme I), that is, oral omeprazole, clarithromycin and amoxicillin, twice a day, and 43 patients received conventional triple therapy + Anwei Qingyou formula, taken orally twice a day (scheme II). The improvement of clinical symptoms, the quality of ulcer healing, clinical effectiveness and recurrence rate were analyzed after 4 weeks of treatment. Patients were followed up for six months.

RESULTS

After treatment with corresponding regimen, the total clinical effective rate of scheme II was 97.57% (42/43), which was significantly higher than 82.50% (33/40) of scheme I. Six-month follow-up results showed that the recurrence rate in scheme II patients was 4.65% (2/43), which was significantly lower than 20.00% (8/40) in the scheme I group (χ 2 = 5.479, 4.607, all P < .05). After one course of treatment, the levels of serum EGF and PGE2 in scheme II group were higher than those in scheme I group (P < .05).

CONCLUSION

In combination with the conventional western medicine treatment, Anwei Qingyou formula administration in PU patients effectively improves the overall control of the disease and therapeutic effectiveness.

Occurrence and Characteristics of Staphylococcus aureus Strains along the Production Chain of Raw Milk Cheeses in Poland

Cheeses produced from unpasteurized milk by traditional production methods may contain many groups of microorganisms, including Staphylococcus aureus. The aim of this study was to determine the occurrence of S. aureus in the artisanal cheese production chain from unpasteurized milk. We investigated the prevalence of S. aureus strains isolated from various stages of artisanal cheese of unpasteurized milk production from farms in the northeastern and southern parts of Poland and characterized them. Characterization included antimicrobial susceptibility by microbroth dilution and biofilm formation by in vitro assay. Among all strains, the presence of enterotoxigenic genes and genes involved with biofilm formation and antibiotic resistance were screened by PCR-based methods. A total of 180 samples were examined. A high percentage of strains were resistant to penicillin (54/58.1%) and tobramycin (32/34.4%). Some tested isolates also showed resistance to the macrolide class of antibiotics: azithromycin, clarithromycin, and erythromycin at 17/18.3%, 15/16.1%, and 21/22.6%, respectively. Among tested isolates, we also found phenotypic resistance to oxacillin (9/9.7%) and cefoxitin (12/12.9%). The blaZ gene encoding penicillin resistance was the most common gene encoding antibiotic resistance among the tested strains. All isolates showing phenotypic resistance to cefoxitin possessed the mecA gene. The study also evaluated the prevalence of biofilm-associated genes, with eno the most frequently associated gene. Eighty-nine out of 93 S. aureus isolates (95.7%) possessed at least one enterotoxin-encoding gene. The results of this study showed that production of raw milk cheeses may be a source of antibiotic resistance and virulent S. aureus. Our results suggest that artisanal cheese producers should better control production hygiene.