Bacterial Test Research Articles

Study on the correlation between abdominal infection and psychological stress in children based on nucleic acid detection

BACKGROUND Diagnosing and treating abdominal infection in children remains a challenge. Nucleic acid detection, as a rapid and accurate diagnosis tool, has great significance in this field. AIM To investigate the diagnosis and treatment of abdominal infection by nucleic acid detection and its possible correlation with psychological stress in children. METHODS A total of 50 pediatric patients diagnosed with abdominal infections between September 2020 and July 2021 were included in this study. Intra-abdominal pus samples were collected for pathogen culture, drug susceptibility testing, and broad-spectrum bacterial nucleic acid testing. Psychological stress, anxiety, depression, and coping styles were assessed using the coping with a disease (CODI) scale. RESULTS Based on susceptibility testing, a regimen of cefazoxime, piperacillin/tazobactam, and metronidazole or ornidazole achieved 100% effectiveness in treating appendicitis. Psychological assessments revealed a positive correlation between pressure level and both anxiety (r = 0.324, P = 0.001) and depressive disorders (r = 0.325, P < 0.001). Acceptance and distancing as coping strategies were negatively correlated with anxiety and depression, while negative emotional responses were strongly associated with increased anxiety (r = 0.574, P < 0.001) and depression (r = 0.511, P = 0.001). Coping strategies such as illusion and escape showed no significant correlation with emotional outcomes. CONCLUSION Nucleic acid testing helps in the diagnosis of abdominal infections in children, and also focuses on children's mental health.

Factor analysis for assessing the etiopathogenesis of facial boils in military personnel

Background: Boils are the most prevalent non-odontogenic inflammatory condition of the head and neck. The treatment of skin and subcutaneous tissue inflammations in the Russian Armed Forces (RAF) is a pressing issue. We were unable to find any data on the etiopathogenesis of facial boils in otherwise healthy RAF members, as well as the factors that contribute to the development of this condition. Aim: To examine the causes of facial boils in military personnel, the factors that contribute to their development, and the association between them using factor analysis. Materials and Methods: Between 2019 and 2021, 53 patients aged 18 to 25 years were examined and treated for abscess-forming face boils. Of these, 38 (72%) were conscripts and 15 (28%) were contract servicemen. At admission, clinical examinations (complaints, history taking, status localis, facial skin type and status) and laboratory tests (complete blood count, blood chemistry, immunoassay, and bacterial tests, including the composition and antibiotic sensitivity of microflora) were performed. The control group included 30 otherwise healthy individuals aged 18 to 25 years. A mathematical model for predicting maxillofacial boil development in military personnel was generated using binomial regression analysis (logistic regression). The following variables were considered: age, length of service, season of disease development, serum glucose level, lymphocyte count, white blood cell count, CD3+, CD4+, CD8+, IgA, IgG, IgM, immunosuppressive regulatory T cells (CD4+CD25brightCD45+; % of all T helper cells), skin type, and microbial composition of maxillofacial skin. Results: The mathematical model revealed that oily skin in combination with specific blood lymphocyte (20.30±1.03%) and IgG parameters (10.15±0.70%) increases the risk of maxillofacial boils in military personnel. Conclusion: The study revealed the cumulative effect of general and local factors on the development and progression of facial boils in military personnel, allowing for more accurate prevention and treatment strategies.

Survey of clinical microbiology and infectious disease testing capabilities among institutions in Africa.

Inadequate laboratory infrastructure and testing capabilities are a major impediment to addressing the infectious disease burden in Africa. Therefore, the aims of this study were to characterize the clinical microbiology/infectious disease laboratory capabilities among countries in Africa. A survey to assess the microbiological testing capabilities at hospitals, government laboratories, and free-standing public and private laboratories in African countries was developed by subject matter experts. Questions included institutional demographics and microbiology services in the broad categories of bacteriology, virology, mycology, parasitology, and rapid diagnostics/point-of-care testing. The survey was distributed using the American Society of Clinical Pathology email listserv between June and August 2022. In total, 131 unique institutions in 28 countries endorsed at least 1 type of microbiology service, with parasitology (80.9%, 106/131) and bacteriology (77.9%, 102/131) being most common, while mycology (45.0%, 59/131) and virology (45.8%, 60/131) laboratories were less prevalent. The most frequently performed bacteriology test was bacterial identification (90.2%, 92/102), followed by aerobic bacterial cultures and antimicrobial susceptibility testing (both 89.2%, 91/102). Among all clinical microbiology/infectious disease laboratories, the most commonly tested agents were HIV (90.8%, 119/131), Treponema pallidum (78.6%, 103/131), Plasmodium falciparum (76.3%, 100/131), Mycobacterium tuberculosis (76.3%, 100/131), and hepatitis C virus (74.8%, 98/131). These findings provide contemporary data regarding the availability of critical infectious disease testing capabilities among institutions in Africa. These results and future additional studies will be crucial for understanding where strategic investment in the laboratory and public health infrastructure is warranted.

Prevalence of multidrug-, extensively drug-, and pandrug-resistant bacteria in clinical isolates from King Khaled Hospital, Najran, Saudi Arabia

Abstract Background Saudi Arabia faces a growing antimicrobial resistance (AMR) problem, exacerbated by the widespread use of antibiotics in clinical and agricultural settings. Despite this, AMR surveillance has been limited, particularly in regions like Najran, making this study critical for informing local and national public health strategies. Aim This study explored the prevalence of multidrug-resistant, extensively drug-resistant, and Pandrug-resistant bacteria in Najran, Saudi Arabia. Study design This is a cross-sectional study. Methods This study included 559 diverse clinical samples (urine, wound, etc.) collected from various departments in King Khaled Hospital, Saudi Arabia. The Phoenix BD instrument was used for complete bacterial identification and antibiotic sensitivity testing. Demographic and clinical data were analyzed statistically. Results Of the 559 samples, the culture positivity rates were as follows: 51% for Escherichia coli, 22% for Staphylococcus aureus, 14% for Klebsiella pneumoniae, 6% for Acinetobacter baumannii, 6% for Pseudomonas aeruginosa, and 1% for Enterococcus faecium. Majority of the cases were from male (57%), and age 50+ (59%) recorded highest cases. Participants from outpatient department (OPD) ward recorded the highest (56%) cases, while urine sample recorded the highest (49%) cases. About 84% of the isolates were multidrug‑resistance (MDR), 10% were extensively drug‑resistance (XDR), and 6% pandrug‑resistance (PDR). Our analysis showed high sensitivity to Oxazolidonone, Tetracycline, carbapenems, Lipopeptide, Aminoglycopeptide classes of antibiotics. Conclusions The study revealed a high prevalence of drug resistance, highlighting the critical importance of continued surveillance and research to mitigate the spread of antimicrobial resistance and preserve the effectiveness of existing therapies.

In Vitro Degradation of Collagen-Based Membranes for Guided Bone Regeneration After Zn-Ions or Doxycycline Functionalization

Collagen-based membrane is the most commonly used biomaterial for guided bone and tissue regeneration; however, its barrier function can be threatened by its rapid degradation pattern, affecting the success of the regeneration process. Differences in the origin and functionalization of the membrane to obtain better properties can alter the degradation rate. The objective of this study was to examine the biodegradation pattern of two commercially available collagen membranes (Jason® and Collprotect®) manufactured using porcine pericardium or dermis, doped or not with zinc-ions or doxycycline, in a period up to 21 days. The membrane specimens were subjected to hydrolytic and bacterial degradation tests. The different immersion times were carried out from 12 h up to 21 days. At each time point, quantitative measurements of thickness and weight were made using a digital caliper and an analytic microbalance, respectively. ANOVA and Student–Newman–Keuls tests were carried out for comparison purposes (p < 0.05). The differences between time-points within the same membranes and solutions were assessed by pairwise comparisons (p < 0.001). Unfunctionalized Jason membrane made of porcine pericardium attained the highest resistance to both degradation tests. The functionalization of the membranes did not alter the biodegradation patterns. All the membranes completely degraded before 48 h in the bacterial collagenase solution, which was the most aggressive test.

Kinetic Bacterial Endotoxin Testing Methods: Specifics of Analytical Conditions Exemplified by Medicinal Products from Different Classes

INTRODUCTION. Kinetic bacterial endotoxin (BE) testing methods based on amoebocyte lysate from the haemolymph of the horseshoe crab can quantify BEs in parenteral medicinal products across a broad range of concentrations. To develop a specific analytical procedure that is based on these methods and can be implemented into pharmaceutical quality control and standardisation, it is required to ascertain the conditions for its use, in particular, to determine the lowest product dilution that would neutralise interfering factors.AIM. This study aimed to develop an analytical procedure for the quantitative determination of BEs by the kinetic chromogenic method.MATERIALS AND METHODS. The study examined samples of medicinal products containing active substances from different classes, including a monoclonal antibody (mepolizumab) and a direct-acting anticoagulant (nadroparin). The BE limits for mepolizumab and nadroparin were ≤20 EU/mL and ≤95 EU/mL, respectively. The samples were tested at different dilutions, which did not exceed the maximum valid dilution. The measurements were performed using a BioТek EL×800 photocolourimeter and EndoScan-V software.RESULTS. The results for mepolizumab samples show that the kinetic chromogenic method can quantify BEs in mepolizumab medicinal products in the dilution range of 1:10 to 1:40. The study detected BEs in quantities of 0.0078–0.224 EU/mL within this dilution range. However, at a dilution ratio of 1:50 or higher, the method is suitable only for qualitative BE tests. For nadroparin medicinal products, the quantitative determination of BEs should start at a dilution of 1:1000 (the study demonstrated no influence of interfering factors at this dilution).CONCLUSIONS. The authors developed analytical procedures for the determination of BEs in mepolizumab and nadroparin medicinal products by the kinetic chromogenic method (method D). When developing analytical procedures for the quantification of BEs in individual medicinal products, the developer should determine the lowest sample dilution that would neutralise interfering factors. Subsequently, the dilution should be specified in the documentation for the analytical procedure. This approach can enhance assay accuracy and save time and resources in routine testing.

Prevalence of some Metallo β-lactamase enzymes genes in P. aeruginosa isolated from different clinical sample in Baghdad, Iraq

The increasing challenge of carbapenem antibiotics resistance caused by Pseudomonas aeruginosa is one of the global healthcare problems. P. aeruginosa is a significant opportunistic infection. For epidemiological reasons, identifying resistance genes is essential, and it is also desirable to quickly identify the techniques for producing carbapenemase enzymes. So, the study aims to determine the prevalence of beta-lactamase encoding genes (blaIMP, blaVIM, bla GIM, and bla SPM) phenotypically and genotypically in P. aeruginosa isolates to address the epidemiological spread of these genes in Baghdad city. The study identified P. aeruginosa isolates from various clinical sources by chemical characterization and VITEK 2 system, the antibiogram test, phenotypic screening carbapenem resistance by Combined disk synergy test (CDST), and conventional PCR were used to detect presence of VIM, IMP, SPM, and GIM genes. Bacterial susceptibility testing revealed (40%) of isolates were resistant to Imipenem and (85%) of them positive to CDST. Genotypic screening on phenotypic Metallo-β-lactamase isolates showed that (100%) isolates contained blaVIM genes, blaGIM genes (88%), whereas (65%) isolates carried blaSPM genes. In this investigation, there was no evidence of blaIMP among carbapenem-resistant isolates. The study appeared high prevalence of multi-drug resistance P. aeruginosa isolates that produce carbapenemase enzymes and having β- lactamase genes in local hospitalized patients compared to global ratio. Expanding the sample size and types of enzymes screening in MDR P. aeruginosa should be the main focus in the future research.

53 Clinical characteristics and outcomes of children hospitalized with RSV-associated acute respiratory infections

Abstract Background Respiratory syncytial virus (RSV) is one of the most common acute respiratory infections (ARI) in infants and young children. After the relaxation of COVID-19 pandemic restrictions, children’s hospitals worldwide experienced unprecedented volumes and severity in presentation of children admitted with ARIs, such as RSV. It is unknown whether the increase in volumes was also associated with changes in the typical demographic, severity and outcomes of patients with RSV infections. Objectives To describe sociodemographic characteristics, clinical presentation, management including diagnosis and disposition and clinical outcomes of children under the age of 18 years admitted to tertiary care paediatric hospital with RSV-associated ARI. Design/Methods Observational cohort of children and adolescents aged 0-18 years admitted to two large Canadian children’s hospitals between July 1, 2022 - December 31, 2022, who had microbiological evidence of RSV infection. Detailed clinical and demographic information were extracted, including admission and discharge diagnoses, diagnostic tests, viral and bacterial testing, interventions, and respiratory settings. Clinical outcomes and complications were collected, including length of hospital admission, paediatric intensive care unit (PICU) admission, need for invasive mechanical ventilation, disposition, and death. Results There were 455 patients admitted with an RSV infection, of which a third (35.0%, n=146) were transfers from other hospitals. Cases were 41.0% male and the median age was 1.22 years (interquartile range [IQR] 0.19-3.06). Nearly two-thirds of patients (62.0%, n=284) were younger than 2 years of age, 8.6% had a history of prematurity. One third (31.0%, n=142) of patients had at least one documented comorbid condition, the most common diagnosis was asthma (6.6%). In addition to RSV, 3.5% (n=16) of patients had a simultaneous bacterial pathogen identified. Most patients (73%, n=330) were only RSV positive, while 24% (n=109) had two pathogens identified. One quarter (25.9%) were admitted to the PICU. The median length of hospital stay was 3 days (IQR 2.00-5.00) and for those admitted to the PICU, nearly two thirds of patients (63.0%, n=75) were admitted for less than 4 days. 0 patients died. The most common discharge diagnosis in 61.0% of patients (n=279) was bronchiolitis. There were 56 patients (12.3%) who had an unscheduled return visit to the ED within 30 days of discharge with 23.0% (n=13) requiring readmission to the hospital. Conclusion There continues to be a substantial volume of hospitalizations secondary to RSV infection, predominantly in those <2 years of age, with a prominent diagnosis of bronchiolitis. A quarter of patients had notable severity requiring PICU admission.

Molecular identification and antimicrobial resistance patterns of enterobacterales in community urinary tract infections among indigenous women in Ecuador: addressing microbiological misidentification

BackgroundAntibiotic resistance of Enterobacterales poses a major challenge in the treatment of urinary tract infections (UTIs). In low- and middle-income countries (LMICs), standard microbiological (i.e. urine culture and simple disk diffusion test) methods are considered the “gold standard” for bacterial identification and drug susceptibility testing, while PCR and DNA sequencing are less commonly used. In this study, we aimed to re-identifying Enterobacterales as the primary bacterial agents responsible for urinary tract infections (UTIs) by comparing the sensitivity and specificity of traditional microbiological methods with advanced molecular techniques for the detection of uropathogens in indigenous women from Otavalo, Ecuador.MethodsA facility-based cross-sectional study was conducted from October 2021 to February 2022 among Kichwa-Otavalo women. Pathogens from urine samples were identified using culture and biochemical typing. Morphological identification was doble-checked through PCR and DNA sequencing of 16S, recA, and rpoB molecular barcodes. The isolates were subjected to antimicrobial susceptibility-testing using disk diffusion test.ResultsThis study highlighted a 32% misidentification rate between biochemical and molecular identification. Using traditional methods, E. coli was 26.19% underrepresented meanwhile Klebsiella oxytoca was overrepresented by 92.86%. Furthermore, the genera Pseudomonas, Proteus, and Serratia were confirmed to be E. coli and Klebsiella spp. by molecular method, and one Klebsiella spp. was reidentified as Enterobacter spp. The susceptibility profile showed that 59% of the isolates were multidrug resistant strains and 31% produced extended spectrum beta-lactamases (ESBLs). Co-trimoxazole was the least effective antibiotic with 61% of the isolates resistant. Compared to previous reports, resistance to nitrofurantoin and fosfomycin showed an increase in resistance by 25% and 15%, respectively.ConclusionsCommunity-acquired UTIs in indigenous women in Otavalo were primarily caused by E. coli and Klebsiella spp. Molecular identification (16S/rpoB/recA) revealed a high rate of misidentification by standard biochemical and microbiological techniques, which could lead to incorrect antibiotic prescriptions. UTI isolates in this population displayed higher levels of resistance to commonly used antibiotics compared with non-indigenous groups. Accurate identification of pathogens causing UTIs and their antibiotic susceptibility in local populations is important for local antibiotic prescribing guidelines.

Impedance Spectroscopy for Bacterial Cell Monitoring, Analysis, and Antibiotic Susceptibility Testing.

Conventional approaches for bacterial cell analysis are hindered by lengthy processing times and tedious protocols that rely on gene amplification and cell culture. Impedance spectroscopy has emerged as a promising tool for efficient real-time bacterial monitoring, owing to its simple, label-free nature and cost-effectiveness. However, its limited practical applications in real-world scenarios pose a significant challenge. In this review, we provide a comprehensive study of impedance spectroscopy and its practical utilization in bacterial system measurements. We begin by outlining the fundamentals of impedance theory and modeling, specific to bacterial systems. We then offer insights into various strategies for bacterial cell detection and discuss the role of impedance spectroscopy in antimicrobial susceptibility testing (AST) and single-cell analysis. Additionally, we explore key aspects of impedance system design, including the influence of electrodes, media, and cell enrichment techniques on the sensitivity, specificity, detection speed, concentration accuracy, and cost-effectiveness of current impedance biosensors. By combining different biosensor design parameters, impedance theory, and detection principles, we propose that impedance applications can be expanded to point-of-care diagnostics, enhancing their practical utility. This Perspective focuses exclusively on ideally polarizable (fully capacitive) electrodes, excluding any consideration of charge transfer resulting from Faradaic reactions.

Comparison and mechanism study on solidification of loose pisha sandstone by indigenous bacteria and sporosarcina pasteurii

Pisha sandstone is a kind of sandstone which is easy to collapse by water in Shanxi, Shaanxi and Inner Mongolia of China, and suffers from hydraulic erosion all the year round. In recent years, some scholars have used microbial induced calcium carbonate precipitation (MICP) technology to solidify Pisha sandstone to improve the water erosion resistance of Pisha sandstone. However, for the climate environment with low average temperature in Pisha sandstone area, the commonly used Sporosarcina pasteurii are not well adapted. The purpose of this study is to use the indigenous strainsto solidify the loose Pisha sandstone, and to compare the growth adaptability, mechanical properties and water erosion resistance of the solidified layer with Sarcina pasteurii at different temperatures, and to explore the mechanism of different temperatures and strains affecting the microbial solidification of Pisha sandstone from the micro scale. At the same time, a mixed bacterial liquid solidification test was also set up. The results showed that the solidified thickness of indigenous strains was 4.65 % higher than that of Sporosarcina pasteurii, and the thickness and strength of mixed strains were increased by 19.57 % and 36.62 %, respectively. The growth and solidification effect of indigenous strains were less affected by low temperature. Compared with Sporosarcina pasteurii, at low temperature, the bacterial concentration decrease of indigenous strains was reduced by 26.13 %, the thickness loss of solidified layer was reduced by 13.04 %, and the strength loss of solidified layer was reduced by 13.39 %. The effect of low temperature on the growth of bacteria is mainly reflected in affecting the maximum concentration of bacteria and the growth rate. The effect on MICP mainly reflected in affecting the life activities of bacteria and the crystal form and morphology of calcium carbonate. The research results provide a theoretical basis for the MICP technology application of indigenous strains and multi-strains in Pisha sandstone area soil reinforcement and solidification slope.

Antibiotic Susceptibility among Infective Endocarditis Population: Syndromic Antibiogram Evaluation at Indonesian National Cardiovascular Center

Infective Endocarditis (IE) is a life-threatening disease with a high mortality rate (25%). Laboratory approaches to support the diagnosis of IE especially blood and/or cardiac vegetation culture, are crucial for providing definitive therapy. However, negative culture is frequently observed, therefore empirical use of antibiotics seems unavoidable and may lead to increasing antimicrobial resistance. This study aims to observe the prevalence of antibiotic susceptibility among the IE population using the WISCA approach. This retrospective study observed medical record data of all inpatients diagnosed with IE according to ICD-10 at Cardiovascular Center Harapan Kita Hospital (NCCHK) between January 2018 and December 2022. Patient data were combined with bacterial identification and antibiotic susceptibility test data from the laboratory information system, and evaluated based on period (year). A total of 67,858 inpatients and 1.1% (n=772) were diagnosed with IE. Successful culture growth (blood and/or cardiac vegetation specimen) was between 36.8% and 70% annually. Streptococcus viridans group (82/237, 34.6%) and Coagulase-negative Staphylococci (57/237, 24.1%) were dominantly observed among the IE population. Low susceptibility among Penicillin (34.3%) towards Gram-positive bacteria, as first-line treatment option in IE. Meanwhile, high susceptibility range was observed in Ceftriaxone (95.7%), Gentamicin (80.4%), Rifampicin (84.4%), and Vancomycin (98.7%) as second-line treatment in IE. Despite the low prevalence, the occurrence of antimicrobial resistance in IE has become a priority concern. Continuing the syndromic antibiogram is mandatory to assist the trend of empirical antibiotic usage and refine the established local treatment guidelines.

Presence of Enterococci in Cats with Urinary Tract Infections and Antibiotic Resistance Profiles

Background: Bacterial urinary tract infection (UTI) is one of the most common diseases in cats caused by an imbalance between the natural host defence mechanisms of the urinary tract and virulent bacteria. This study investigated the prevalence and antimicrobial susceptibility of enterococci isolated from cats presenting urinary tract problems to veterinary clinics in Istanbul. Methods: 100 urine samples were collected from cats by cystocentesis and plated on blood agar. Isolates found catalase and oxidase negative plated on Enterococcocel agar. After incubation, the isolates formed black colonies were tested by PCR using E. faecium and E. faecalis-specific primers. Then the antibiotic susceptibility of the isolates was determined. Result: Eight of the 100 isolates that formed black colonies on Enterococcosel agar were identified as Enterococcus spp. After PCR tests, six isolates were classified as E. faecalis, one isolate was classified as E. faecium and one isolate that did not form a band was classified as Enterococcus spp. As a result of the Kirby-Bauer disc diffusion method used to determine the antibiotic susceptibility of the isolates, most resistance was found to cephalothin (100%) and penicillin, erythromycin, clindamycin and tetracycline (87.5%). While vancomycin resistance was not observed in any isolate, the lowest resistance was to enrofloxacin and ciprofloxacin (33.3%). Multiple antibiotic resistance was observed in all (100%) isolates. The presence of multi-resistant enterococci in cats represents a significant health threat. Bacterial identification and antimicrobial susceptibility testing should always be performed in urinary tract infections to guide definitive diagnosis and treatment.

Interpenetrated Polymer Network Systems (PEG/PNIPAAm) Using Gamma Irradiation: Biological Evaluation for Potential Biomedical Applications

The potential antimicrobial and antibiofouling properties of previously synthesized PEG/NiPAAm interpenetrated polymer networks (IPNs) were investigated against three of the most common bacteria (E. coli, S. aureus, and S. epidermidis). The main goal was to evaluate the material’s biocompatibility and determine its potential use as an antifouling component in medical devices. This was intended to provide an alternative option that avoids drug usage as the primary treatment, thus contributing to the fight against antimicrobial resistance (AMR). Additionally, characterization and mechanical testing of the IPN were carried out to determine its resistance to manipulation processes in medical/surgical procedures. IPNs with different NiPAAm ratios exhibited excellent cytocompatibility with BALB/3T3 murine fibroblast cells, with cell viability values of between 90 and 98%. In addition, the results regarding the adsorption of albumin as a model protein showed a nearly constant adsorption percentage of almost zero. Furthermore, the bacterial inhibition tests yielded promising results, demonstrating effective pathogen growth inhibition after 48 h. These findings suggest the material’s suitability for use in biomedical applications.

Whole-genome sequencing resolves biochemical misidentification of Neisseria species from urogenital specimens.

Neisseria meningitidis (Nm) and Neisseria gonorrhoeae (Ng) are human pathogens that sometimes occupy the same anatomical niche. Ng, the causative agent of gonorrhea, infects 87 million individuals annually worldwide and is an urgent threat due to increasing drug resistance. Ng is a pathogen of the urogenital tract and may infect the oropharyngeal or rectal site, often asymptomatically. Conversely, Nm is an opportunistic pathogen. While often a commensal in the oropharyngeal tract, it is also the leading cause of bacterial meningitis with 1.2 million cases globally, causing significant morbidity and mortality. Horizontal gene transfer (HGT) is likely to occur between Ng and Nm due to their shared anatomical niches and genetic similarity, which poses challenges for accurate detection and treatment. Routine surveillance through the Gonococcal Isolate Surveillance Project and Strengthening the U.S. Response to Resistant Gonorrhea detected six concerning urogenital Neisseria isolates with contradicting species identification in Milwaukee (MIL). While all six isolates were positive for Ng using nucleic acid amplification testing (NAAT) and matrix-assisted laser desorption/ionization time of flight identified the isolates as Ng, two biochemical tests, Gonochek-II and API NH, classified them as Nm. To address this discrepancy, we performed whole-genome sequencing (WGS) using Illumina MiSeq on all isolates and employed various bioinformatics tools. Species detection analysis using BMScan, which uses WGS data, identified all isolates as Ng. Furthermore, Kraken revealed over 98% of WGS reads mapped to the Ng genome and <1% to Nm. Recombination analysis identified putative HGT in all MIL isolates within the γ-glutamyl transpeptidase (ggt) gene, a key component in the biochemical tests used to differentiate between Nm and Ng. Further analysis identified Nm as the source of HGT event. Specifically, the active Nm ggt gene replaced the Ng pseudogenes, ggt1 and ggt2. Together, this study demonstrates that closely related Neisseria species sharing a niche underwent HGT, which led to the misidentification of species following biochemical testing. Importantly, NAAT accurately detected Ng. The misidentification highlights the importance of using WGS to continually evaluate diagnostic or bacterial identification tests.

Heterocyclic phytometabolites formononetin and arbutin prevent in vitro oxidative and alkylation-induced mutagenicity

Phenolic phytometabolites are promising bioactive compounds for management of genomic instability related diseases. Formononetin (FMN) and arbutin (ARB) are found in several plant sources. Our goal was to investigate the safety and efficacy of FMN and ARB using in vitro both standardized and alternative toxicogenetic methods. FMN and ARB were evaluated through the OECD’S guidelines No. 471 (Bacterial Reverse Mutation Test –Salmonella/microsome) and No. 487 (In vitro Mammalian Micronucleus Test – CBMN assay), accordingly to the mentioned recommendations. Also, antimutagenicity of FMN and ARB was assessed in S. Typhimurium strains TA98, TA100 and TA1535, following pre-, co- and post- treatment protocols. Liver human lineages HepG2 and F C3H were assayed for cytotoxicity after exposure to FMN and ARB (24, 48 and 72 h) using in vitro WST-1 test. ARB showed no mutagenicity in the Salmonella/microsome test under both metabolic conditions (in presence or absence of 4 % S9 mix), but FMN was cytotoxic to the TA97 and TA100 strains after metabolic activation. Under this same condition, FMN induced an increase in the mutagenic index of strain TA1535 at two of the highest tested concentrations. Even so, ARB and FMN exhibited protection against the induced alkylation of DNA in multiple action modes. In the antimutagenicity assay, FMN reached the maximum of 80 % of oxidative-provoked mutagenicity reduction in TA98 strain in co-treatment with known mutagen, besides 69 % of reduction in TA100 in the same exposure condition. ARB showed up to reduce induced mutagenicity in strains TA100 and TA1535, reaching percentages from 55 % to 100 % of antimutagenicity in all of the tested exposure models against alkylating agent. In the CBMN assay, no increase in micronuclei formation was observed. The results suggest that FMN and ARB prevent DNA from mutation using multi-targeted antimutagenic roles. Finally, our data suggests that FMN and ARB are not genotoxic and presented encouraging antimutagenicity action in vitro, being promising compounds for use in genomic instability-related diseases therapeutics.

Development and evaluation of novel taste-masking tilmicosin microcapsules containing octenylsuccinic anhydride modified starch and maltodextrin as wall materials

Tilmicosin (TMS) is an important antibiotic in veterinary medicine, but its extreme bitter taste limits its use. In this study, TMS was encapsulated in octenyl succinic anhydride modified starch/maltodextrin (HI-CAP/MD) composite capsules with a spray drying method. The TMS microcapsules (TMS-MC) exhibited good drug loading performance with drug loading (DL) and encapsulation efficiency (EE) of 9.90 ± 0.23 % and 98.03 ± 1.56 %, respectively. There was no significant change in particle diameter and zeta potential for the emulsion and redissolved TMS-MC. These results combined with FT-IR, TGA and DSC showed the crystalline shape and chemical structure of TMS did not change during the microencapsulation. In vitro release characterization in an acidic medium (pH 1.2) and an alkaline medium (phosphate buffered solution, pH 6.8) showed that TMS-MC can be rapidly released in vitro. The bitterness evaluation implied the bitterness of TMS was masked after microencapsulation. In vitro bacterial inhibition test showed the bacterial inhibitory activity of TMS was not reduced by the microencapsulation, but was much better than that of the commercially available tylosin (TLS). Therefore, HI-CAP/MD can effectively encapsulate TMS, mask the bitter taste and maintain a good bacterial inhibitory effect, making a new drug formulation with good development prospects.

Evaluation of inhibitory, immunomodulatory, survival, and growth effects of host-derived Weissella confusa on Macrobrachium rosenbergii challenged with Vibrio parahaemolyticus

Macrobrachium rosenbergii is a highly valuable prawn species in aquaculture due to its current growing demand in the market. However, various bacterial diseases caused by Vibrio parahaemolyticus have been observed to induce mortality in larval, juvenile, and adult stages of M. rosenbergii. While antibiotics are commonly used to manage these diseases, they contribute to antimicrobial resistance, a global concern with serious environmental and health implications. Consequently, the scientific community is exploring host-derived beneficial microorganisms as functional feed additives, offering eco-friendly alternatives that boost shrimp and prawn immunity. The purpose of this study was to examine the effects of host-derived beneficial microorganisms from the gut of M. rosenbergii, on the inhibition, immunomodulation, survival, and growth of M. rosenbergii when exposed to V. parahaemolyticus. The result of this study showed that Weissella confusa C6, a lactic acid bacterium isolated from the gut of M. rosenbergii, significantly inhibits the growth of V. parahaemolyticus R1 as demonstrated in agar well diffusion assay and co-culture assay. Additionally, it showed immunomodulatory effects, indicated by elevated total hemocyte count (THC) and phenoloxidase (PO) activity during the bacterial challenge test. Furthermore, supplementing the diet with W. confusa led to significant improvements in M. rosenbergii, including increased survival rates, weight gain, specific growth rate, better feed conversion ratio, and reduced density of V. parahaemolyticus in the prawn's gut. Therefore, it can be considered a viable option for use as a feed supplement in prawn farming, enhancing M. rosenbergii's immune system, disease resistance, and overall health.

Enhancing infection control in dialysis at a resource limited public healthcare institute: A cross-sectional study on microbiological quality assessment of dialysis water and dialysate

PurposeTo evaluate the microbiological quality of dialysis water and dialysate samples from hemodialysis units at a tertiary care government hospital and to assess the use of culture, endotoxin and periodicity of testing these assays to guide the actions of monitoring the quality of hemodialysis fluids, implement preventive and corrective actions, and improve the safety and outcomes of the dialysis process. MethodsA cross-sectional study was conducted at a 250-bedded super-specialty government hospital with a 24/7 hemodialysis unit equipped with 40 dialysis machines. Dialysis water and dialysate samples were collected monthly and analysed for microbial contamination and endotoxin levels as per AAMI guidelines. Bacterial cultures were done using Reasoner's Agar plates, and endotoxin analysis was performed using gel clot assay. Interpretation of results was based on predefined thresholds. ResultsAmong the 740 samples processed for microbial culture 19.6 % and 80.4% were unacceptable and acceptable respectively.Among the acceptable samples 10.5 % were at action level. At the end of 2 days of incubation, 15.2%dialysis water samples and 5.1%dialysate samples had unacceptable levels of bacterial colonies and at 5days additional 10.6 % dialysis water samples and 7.7%dialysate samples were unacceptable. 21.5 % of the samples tested for endotoxin had unacceptable levels. ConclusionsRegular monitoring of water quality in government healthcare hemodialysis units is crucial for quality of care, timely preventive and corrective actions for mitigating adverse outcomes. Processing cultures for 5–7 days is essential for detecting all contaminated specimens. While there might be a link between endotoxin levels and bacterial contamination, both endotoxin testing and bacterial culture independently are vital for evaluating water quality in dialysis settings. A comprehensive approach integrating various testing methods is necessary to uphold patient safety and enable necessary improvements.

Comprehensive evaluation of clinical antimicrobial resistance using impedance-accelerated single-bacterium multiplex screening strategy

Rapid detection of bacterial antibiotic resistance is paramount in clinical settings to enable timely and effective therapeutic interventions. Traditional approaches such as disc diffusion and broth dilution are indeed dependable, however, they suffer from a notable drawback of long assay durations. This is attributed to the inherent delay caused by bacteria's macroscopic growth rate, which often necessitates measurement periods exceeding 20 hours, a timeframe incompatible with the clinical urgency. In this study, we demonstrate a comprehensive strategy on rapid bacterial antimicrobial resistance profiling and testing in clinical samples via a label-free impedance-accelerated single-bacterium screening. This system involves one newly developed parameter that is calculated from the two-dimensional kernel density values of different density regions in bacterial impedance spectra. By evaluating the changes in bacterial populations over a certain period using this new parameter, antimicrobial resistance of individual strains of bacteria can be determined within 20-minute antibiotics exposure. This high-throughput method rapidly and accurately determines the resistance profiles of five clinical Enterobacteriaceae strains against six antibiotic types. During the analysis of the impedance spectrum, we have also observed that antibiotics with different antimicrobial mechanisms have distinct effects on the bacterial impedance profile. This proposed method demonstrates excellent accuracy and rapid response time, providing a novel and practical strategy for next-generation antimicrobial susceptibility testing (AST) and antibiotic management.