Drug-resistant Cases Research Articles

A STUDY ON IN VITRO ACTIVITY OF FOSFOMYCIN AGAINST ENTEROBACTERIACAE UROPATHOGEN ALONG WITH MICROBIOLOGICAL PROFILE AND ANTIBIOGRAM OF UROPATHOGENS

Background:Urinary tract infection (UTI) is one of the most common infection throughout the world that may affect both the lower and the upper urinary tracts. Aims & Objective:The present study was done to determine various organisms causing Urinary tract infections and to analyse antimicrobial sensitivity patterns of those isolates. Materials and Methods:This prospective study was conducted from April 2020 to March 2021at SIMS& RH, Tumkur. All urine samples were received in Microbiology laboratory for routine microbiology investigations were inoculated on Blood agar and MacConkey agar culture media using calibrated wire loop . Urinary isolates with significant bacteriuria were further processed by conventional biochemical tests and antimicrobial susceptibility testing was done as per standard methods. Results: A total of 697 urine samples were processed in that 324 (46.48%) samples were shown as significant growth of bacteria. Most of the cases seen in (67.28%) female and under age group of 21-30(22.22%).The predominantly Gram-negative bacteria (85.18%) were isolated followed by Gram positive bacteria(10.49%) and Candida spp(4.32%). The Gram negative bacteria showed high sensitivity to Ampicillin sulbactum (88.27%) followed by Amikacin (87.24%). All Gram-positive bacteria isolates is showed sensitivity to Vancomycin (100%).We found that 235( 92.88%) Enterobacteriaceace isolates were is susceptible for Fosfomycin. Conclusion:. Antibiotic resistance has become a major clinical problem worldwide and has increased over the years.Hence antibiotic susceptibility testing should be done to diagnose and treat the drug resistant UTI cases. Fosfomycin may be given empirically in patients with uncomplicated urinary tract infection due to Enterobacteriaceace.

The Burden of Drug-Resistant Tuberculosis among Kenya's Devolved Health Units and Associated Treatment Outcomes

Background: A devolution is a form of decentralisation or the transfer of authority and responsibility from central to lower levels of government for a range of public functions. The drafters of the 2010 Kenyan constitution chose to devolve functions to 47 newly created counties. In Kenya, health is a devolved function that county governments run. Tuberculosis is managed at the county level in coordination with the National Leprosy Tuberculosis and Lung Disease Program (NLTP) with a mission of End TB Strategy to achieve a 95% decline in deaths due to tuberculosis compared with the 2015 baseline and reach an equivalent 90% reduction in tuberculosis incidence rate. Methods: This was a retrospective cohort study that collected data from health facilities accredited by the NLTP for drug-resistant tuberculosis treatment. The study population included patients who tested positive for drug-resistant tuberculosis from 2014 to 2019. Data was sourced from NLTP Electronic Medical Records (TIBU-System). After abstraction, the data was entered into Excel and analysed through STATA software version 13. Results: Of the 2674 enrolled patients in total, there were more males affected with DRTB at 64 % compared to the female patients. The public facilities carried the immense burden of diagnosis and treatment of the patient, having a cumulative number of 83 %, while the prison sector had the lowest number. For the resistance pattern, the new, relapse, and failure of first-line drugs accounted for most drug-resistant cases at 80 %, with only 65 % of the total cases having been done a gene-expert test at the point of screening. Conclusion: With a devolved health unit in Kenya, there needs to be a more coordinated support system from the national government to the county health units in terms of surveillance of TB disease. Regional centralised laboratories for diagnosis and monitoring of TB would reduce the time it takes for samples to come to Nairobi for testing, which takes time before patents are initiated on treatment.

A versatile dilution-treatment-detection microfluidic chip platform for rapid In vitro lung cancer drug combination sensitivity evaluation

Combination drug therapy represents an effective strategy for treating certain drug-resistant and intractable cancer cases. However, determining the optimal combination of drugs and dosages is challenging due to clonal diversity in patients' tumors and the lack of rapid drug sensitivity evaluation methods. Microfluidic technology offers promising solutions to this issue. In this study, we propose a versatile microfluidic chip platform capable of integrating all processes, including dilution, treatment, and detection, for in vitro drug sensitivity assays. This platform innovatively incorporates several modules, including automated discrete drug logarithmic concentration generation, on-chip cell perfusion culture, and parallel drug treatments of cancer cell models. Moreover, it is compatible with microplate readers or high-content imaging systems for swift detection and automated monitoring, simplifying on-chip drug evaluation. Proof of concept is demonstrated by assessing the in vitro potency of two drugs, cisplatin, and etoposide, against the lung adenocarcinoma A549 cell line, under both single-drug and combination treatment conditions. The findings reveal that, compared to conventional microplate approaches with static cultivation, this on-chip automated perfusion bioassays yield comparable IC50 values with lower variation and a 50 % reduction in drug preparation time. This versatile dilution-treatment-detection microfluidic platform offers a promising tool for rapid and precise drug assessments, facilitating in vitro drug sensitivity evaluation in personalized cancer chemotherapy.

Identifying quantitative sncRNAs signature using global sequencing as a potential biomarker for tuberculosis diagnosis and their role in regulating host response

ObjectivesThe study aimed to identify a quantitative signature of circulating small non-coding RNAs (sncRNAs) as a biomarker for pulmonary tuberculosis disease (active-TB/ATB) and explore their regulatory roles in host-pathogen interactions and disease progression. MethodsWe conducted a cross-sectional study recruiting subjects diagnosed with active-TB (drug-sensitive and drug-resistant) and healthy controls. Sera samples were collected and utilized for preparing small RNA libraries. Quantitative patterns of circulating sncRNAs (miRNAs, piRNAs and tRFs) were identified via high-throughput sequencing and DeSeq2 analysis and validated in independent active-TB cohorts. Functional knockdown for two selected miRNAs were also performed. ResultsA diagnostic signature of four sncRNAs for both drug-sensitive and drug-resistant active-TB cases was validated, exhibiting an AUC of 0.96 (95% CI: 0.937–0.996, p < 0.001) with 86.7% sensitivity (95% CI: 0.775–0.932) and 91.7% specificity (95% CI: 0.730–0.990) in ROC analysis. Functional knockdown demonstrated regulatory roles of hsa-miR-223-5p and hsa-miR-10b-5p in Mycobacterium tuberculosis (Mtb) growth and pro-inflammatory cytokine expression (IL-6 and IL-8). ConclusionThe study identified a diagnostic tool utilizing a signature of four sncRNAs with high specificity and sensitivity, enhancing our understanding of sncRNAs as ATB diagnostic biomarker. Additionally, hsa-miR-223-5p and hsa-miR-10b-5p demonstrated potential roles in Mtb pathogenesis and host-response to infection.

High-throughput nanopore targeted sequencing for efficient drug resistance assay of Mycobacterium tuberculosis.

Drug-resistant tuberculosis (TB), especially multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB), is one of the urgent clinical problems and public health challenges. Culture-based phenotypic drug susceptibility testing (pDST) is time-consuming, and PCR-based assays are limited to hotspot mutations. In this study, we developed and validated a convenient and efficient approach based on high-throughput nanopore sequencing technology combined with multiplex PCR, namely nanopore targeted sequencing (NTS), to simultaneously sequence 18 genes associated with antibiotic resistance in Mycobacterium tuberculosis (MTB). The analytical performance of NTS was evaluated, and 99 clinical samples were collected to assess its clinical performance. The NTS results showed that MTB and its drug resistance were successfully identified in approximately 7.5 h. Furthermore, compared to the pDST and Xpert MTB/RIF assays, NTS provided much more drug resistance information, covering 14 anti-TB drugs, and it identified 20 clinical cases of drug-resistant MTB. The mutations underlying these drug-resistant cases were all verified using Sanger sequencing. Our approach for this TB drug resistance assay offers several advantages, including being culture-free, efficient, high-throughput, and highly accurate, which would be very helpful for clinical patient management and TB infection control.

Intrabacterial Nitroreductase‐Activated Imaging and Persistently Illuminated Photodynamic Therapy for Intracellular Infection Theranostics

AbstractIntracellular bacterial (ICB) infection is one of the most life‐threatening cases of drug resistance, and photodynamic therapy (PDT) is challenged by limited light penetration into tissues and unspecific toxicity to host cells. Herein, theranostic nanoparticles (NPs) are developed to facilitate on‐demand activation of photosensitizers inside ICBs and persistent PDT of deep‐tissue ICB infections. Mechanoluminescent SrAl2O4:Eu2+ and persistence luminescent CaS:Eu2+ are sequentially deposited on mesoporous silica to prepare mSC, followed by encapsulation by bacterial membranes with loaded nitroreductase (NTR)‐activatable methylene blue (nMB) to obtain mSC‐nMB@BM NPs. The fluorescence quenching of nMB with mSC offers few cytotoxicities even under ultrasonication, and bacterial membrane coatings mediate the specific NP internalization into ICB‐infected macrophages. Bacterial pore‐forming toxins trigger nMB release from NPs, and intrabacterial NTR rejuvenates methylene blue probes from nMB for real‐time imaging of ICB infections. Ultrasonication of NPs continuously excites the rejuvenated methylene blue to generate reactive oxidative species and reduce viable ICBs by 3.54 log magnitude folds. NP treatment on ICB‐infected mice exhibits full survival and restores viscera functions without any pathological abnormality. Therefore, this concise NP design demonstrates capabilities of bacterial membrane‐mediated specific internalization, bacterial toxin‐triggered release and intrabacterial NTR‐rejuvenation of fluorescent probes, and persistent internal light‐illumination for ICB theranostics.

Beyond oncology: Selinexor's journey into anti-inflammatory treatment and long-term management.

Selinexor, a selective inhibitor of nuclear export (SINE), is gaining recognition beyond oncology for its potential in anti-inflammatory therapy. This review elucidates Selinexor's dual action, highlighting its anti-tumor efficacy in various cancers including hematologic malignancies and solid tumors, and its promising anti-inflammatory effects. In cancer treatment, Selinexor has demonstrated benefits as monotherapy and in combination with other therapeutics, particularly in drug-resistant cases. Its role in enhancing the effectiveness of bone marrow transplants has also been noted. Importantly, the drug's impact on key inflammatory pathways provides a new avenue for the management of conditions like sepsis, viral infections including COVID-19, and chronic inflammatory diseases such as Duchenne Muscular Dystrophy and Parkinson's Disease. The review emphasizes the criticality of managing Selinexor's side effects through diligent dose optimization and patient monitoring. Given the complexities of its broader applications, extensive research is called upon to validate Selinexor's long-term safety and effectiveness, with a keen focus on its integration into clinical practice for a diverse spectrum of disorders.

Population structure and spatial distribution of Mycobacterium tuberculosis in Ethiopia

Ethiopia is one of the countries with a high tuberculosis (TB) burden, yet little is known about the spatial distribution of Mycobacterium tuberculosis (Mtb) lineages. This study identifies the spoligotyping of 1735 archived Mtb isolates from the National Drug Resistance Survey, collected between November 2011 and June 2013, to investigate Mtb population structure and spatial distribution. Spoligotype International Types (SITs) and lineages were retrieved from online databases. The distribution of lineages was evaluated using Fisher’s exact test and logistic regression models. The Global Moran’s Index and Getis-Ord Gi statistic were utilized to identify hotspot areas. Our results showed that spoligotypes could be interpreted and led to 4 lineages and 283 spoligotype patterns in 91% of the isolates, including 4% of those with multidrug/rifampicin resistance (MDR/RR) TB. The identified Mtb lineages were lineage 1 (1.8%), lineage 3 (25.9%), lineage 4 (70.6%) and lineage 7 (1.6%). The proportion of lineages 3 and 4 varied by regions, with lineage 3 being significantly greater than lineage 4 in reports from Gambella (AOR = 4.37, P < 0.001) and Tigray (AOR = 3.44, P = 0.001) and lineage 4 being significantly higher in Southern Nations Nationalities and Peoples Region (AOR = 1.97, P = 0.026) than lineage 3. Hotspots for lineage 1 were located in eastern Ethiopia, while a lineage 7 hotspot was identified in northern and western Ethiopia. The five prevalent spoligotypes, which were SIT149, SIT53, SIT25, SIT37 and SIT26 account for 42.8% of all isolates under investigation, while SIT149, SIT53 and SIT21 account for 52–57.8% of drug-resistant TB cases. TB and drug resistant TB are mainly caused by lineages 3 and 4, and significant proportions of the prevalent spoligotypes also influence drug-resistant TB and the total TB burden. Regional variations in lineages may result from both local and cross-border spread.

Routine tuberculosis contact investigation yield and preventive treatment cascade in central Ethiopia

IntroductionThere is a global gap between tuberculosis incident cases and the notified cases. Active household contact investigation is one of the strategies to narrow this gap. It has the advantage of giving early diagnosis and preventive treatment to vulnerable and eligible groups. This study assessed the practice of contact investigation and tuberculosis preventive treatment adherence in central Ethiopia. MethodA cross-sectional study covering all registered bacteriologically confirmed pulmonary tuberculosis patients and their close contacts was conducted in central Ethiopia from January 1, 2022, to December 30, 2022. ResultA total of 1372 household contacts were declared by the index cases. From these 79.44 % (1090) contacts received a one-time tuberculosis screening giving a total of four (0.36 %) active TB cases. Among 484 household contacts of drug-resistant tuberculosis index cases, 5.53 % (14) had presumptive tuberculosis and 0.79 % (2) had active tuberculosis. While among 837 household contacts of drug-susceptible tuberculosis index cases presumptive TB cases were 1.91 % (16) and active TB cases were 0.23 % (2). Of the 142 eligible under 15 children 81.69 % (116) had started tuberculosis preventive treatment and 84.48 % (98) completed the treatment. On multivariable logistic regression, the associated factor for tuberculosis preventive treatment non-adherence was age 2–5 years (aOR, 0.02, 95 % CI (0.002–0.20) and age 5–15 years (aOR, 0.04,95 % CI (0.002–0 0.95)) P=<0.05). ConclusionThere was low contact screening practice in the DR-TB index cases as compared to national and global targets. The yield of routine contact investigation was low and it indicates the quality of screening. Tuberculosis preventive treatment initiation and completion rates were also low as compared to those of many other countries and global achievements which need further improvement, especially for completion. Alternative mechanisms should be planned to increase the yield of tuberculosis screening and tuberculosis preventive treatment adherence.

Epidemiology and outcomes of drug-resistant tuberculosis cases notified in a low-resource district in Kerala, India 2017–2021 – A 5-year retrospective analysis

Objectives: Kasaragod district reports the highest drug-resistant tuberculosis (DR-TB) case notification rates in Kerala. We conducted a cross-sectional study in Kasaragod to describe the DR-TB cases notified from January 2017 to December 2021 and to identify the factors associated with unfavorable treatment outcomes in DR-TB patients. Materials and Methods: We analyzed the programmatic data from the “Nikshay portal” (a web-based patient management information system for [TB] under the National TB Elimination Program), DR-TB treatment cards, and treatment registers available with the district TB center for all the DR-TB patients notified during the study period. We described the DR-TB cases by year, local self-government area (the local administrative setup), age, gender, income level, and treatment outcomes. We compared sociodemographic, anthropometric, and clinical factors among the DR-TB patients with favorable (cured and treatment completed) and unfavorable (died, lost to follow-up, and treatment failure) treatment outcomes. Results: From January 2017 to December 2021, 128 DR-TB cases were notified from Kasaragod. Annual notification rates varied from 1.4 to 3.4/100,000 population with the highest notification in 2019. The proportion of new TB cases notified tested for drug sensitivity rose from 22% in 2017 to 86% in 2021. Seven of 41 local self-government areas had not notified DR-TB cases during 2017–2021. The notification was higher in inter-state border areas and the coastal belt of the district. The notification of DR-TB cases was highest among the 45–59 age group (17/100,000), followed by the 60 above group (11/100,000). Males and those living below the poverty line had higher notification rates. Among the outcomes evaluated 118 DR-TB patients, 89 (75.4%) had favorable outcomes, whereas the remaining 24.6% had unfavorable outcomes (death 18 [15.3%], loss to follow-up 7 [6%], and treatment failure 4 [3.4%]). Age more than 45 years adjusted odds ratio (aOR) 3.1 (95% confidence interval [CI] 1.1–8.8), income category below the poverty line aOR 6 (95% CI 1.2–28.6), admitted at least twice during treatment aOR 9.2 (95% CI 2.8–30.3), and body mass index at diagnosis &lt;18.5 kg/m2 aOR 3 (95% CI 1.1–10.3) were found to be significantly associated with unfavorable treatment outcomes. Conclusion: DR-TB notifications have increased in the Kasaragod district from 2017 to 2021, with a high burden among males aged 45 years and above. The favorable treatment outcome is better than the national and state average. Regular monitoring and follow-up of multidrug-resistant patients with low incomes, above 45 years, and underweight may improve the final treatment outcomes.

Drug-Resistant Bone, Joint and Spine Tuberculosis: Evolution of Diagnosis and Treatment.

Drug resistant (DR) osteoarticular TB (OATB) is a challenge in view of it being deep seated lesion and paucibacillary disease. Case definition, investigation protocol, treatment of proven DR and those cases where DR could not be demonstrated lacks clarity and evidence. Hence, a series of studies were conducted to develop an algorithm to investigate and treat therapeutically refractory disease (TRD) or presumptive drug resistance (PDR) cases of OATB. 6 studies were conducted. Study one and two evaluated criteria to label TRD/PDR. Three subsequent studies were conducted where TDR/PDR or fresh cases of OATB cases were investigated by AFB smear, Bactec/liquid culture, histology and genotypic DST by CBNAAT & LPA. Sixth study was a retrospective evaluation of all DR cases treated for proven or clinical drug resistance (CDR). Patient of bone/spine TB on ATT for 5 months or more show poor clinico-radiological treatment response as worsening of lesion, increased spinal deformity, persistent discharging sinus/ulcer, appearance of fresh lesion, recurrence of previous lesion, wound dehiscence of post-operative surgical scar cab labelled as PDR cases. These cases on histology ascertained TB and were proven DR on genotypic and phenotypic DST and are treated successfully. The patients of histologically ascertained TB and no/indeterminate phenotypic and genotypic DST were successfully treated as clinical drug resistance on MDR protocol. We described an algorithm. We must suspect PDR(TRD) based on criteria described. The tissue must be procured and submitted for AFB smear, histology and phenotypic and genotypic DST for diagnosis of TB. Genotypic and phenotypic DST will be useful to prove (90% instances) type of drug resistance. Remaining on strong clinical suspicion of DR and yet inconclusive on phenotypic/genotypic DST (<10%), may be treated as CDR as MDR. The adverse drug reactions and hepatic side-effects should be monitored diligently and these cases to be treated till healed status is demonstrated.

The potential role of nitric oxide in the anticonvulsant effects of betulin in pentylenetetrazole (PTZ)-induced seizures in mice

Epilepsy poses a significant challenge, especially for drug-resistant cases, necessitating novel treatment avenues. This study explores the potential interplay between nitric oxide (NO) and the anticonvulsant effects of betulin, a triterpene with promising neuroprotective properties. While betulin exhibits anticonvulsant effects, the specific involvement of NO remains inadequately understood, constituting a pivotal gap in current knowledge. One hundred NMRI mice were randomly assigned to diverse treatment groups, with seizures induced by pentylenetetrazol (PTZ). Parameters such as seizure threshold, nitrite levels, total antioxidant capacity (TAC), malondialdehyde (MDA) levels, and iNOS/nNOS gene expressions were assessed. Betulin significantly increased seizure thresholds and mitigated PTZ-induced NO levels. These findings suggest a potential modulation of NO-related pathways, emphasizing betulin's anti-inflammatory and antioxidant attributes. The study sheds light on betulin's multifaceted impact on oxidative stress, NO regulation, and iNOS/nNOS gene expressions. The ability of betulin to suppress iNOS/nNOS gene expressions, leading to reduce NO production, underscores its potential as an anticonvulsant.

Tuberculosis Chest X-Ray Image Retrieval System Using Deep Learning Based Biomarker Predictions.

The world health organization's global tuberculosis (TB) report for 2022 identifies TB, with an estimated 1.6 million, as a leading cause of death. The number of new cases has risen since 2020, particularly the number of new drug-resistant cases, estimated at 450,000 in 2021. This is concerning, as treatment of patients with drug resistant TB is complex and may not always be successful. The NIAID TB Portals program is an international consortium with a primary focus on patient centric data collection and analysis for drug resistant TB. The data includes images, their associated radiological findings, clinical records, and socioeconomic information. This work describes a TB Portals' Chest X-ray based image retrieval system which enables precision medicine. An input image is used to retrieve similar images and the associated patient specific information, thus facilitating inspection of outcomes and treatment regimens from comparable patients. Image similarity is defined using clinically relevant biomarkers: gender, age, body mass index (BMI), and the percentage of lung affected per sextant. The biomarkers are predicted using variations of the DenseNet169 convolutional neural network. A multi-task approach is used to predict gender, age and BMI incorporating transfer learning from an initial training on the NIH Clinical Center CXR dataset to the TB portals dataset. The resulting gender AUC, age and BMI mean absolute errors were 0.9854, 4.03years and . For the percentage of sextant affected by lesions the mean absolute errors ranged between 7% to 12% with higher error values in the middle and upper sextants which exhibit more variability than the lower sextants. The retrieval system is currently available from https://rap.tbportals.niaid.nih.gov/find_similar_cxr.

IJCM_311A: Epidemiological profile of tuberculosis cases at an urban slum in a metropolitan city a cross sectional study

Background: The WHO Global Tuberculosis Programme works towards the goal of a world free of TB, with zero deaths, disease and suffering due to the disease. Tuberculosis (TB) is a preventable and usually curable disease. Yet in 2022, TB was the worlds second leading cause of death from a single infectious agent, after coronavirus disease (COVID-19). The reported global number of people newly diagnosed with TB was 7.5 million in 2022; this is the highest number since WHO began global TB monitoring in 1995. Around 87% of new TB cases occurred in the 30 high TB burden countries, with more than two-thirds of the global total in Bangladesh, China, Democratic Republic of the Congo, India, Indonesia, Nigeria, Pakistan and the Philippines. Objective: To study the epidemiological profile of tuberculosis cases in an urban slum of Mumbai. Methodology: A retrospective record-based analysis of secondary data on tuberculosis (pulmonary and extrapulmonary) reported on the NIKSHAY portal between January to December 2022 at an urban health training center in an urban slum in Mumbai. Results: The total number of drug sensitive TB cases reported in 2022 was 519. Males constituted 42% and females 58%. The most common age group affected was 20-29 years. Pulmonary cases comprised 66.9% of the cases. The total number of Drug resistant TB cases reported were 75, 53 were pulmonary &amp; 22 were extrapulmonary. Conclusion: In contrast to Male predominance (52.26%) of cases in Maharashtra, the urban slum had 42% males affected. India grapples with multiple challenges in combatting tuberculosis (TB), marked by a high disease burden, diagnostic delays, drug resistance, and socioeconomic barriers. While significant strides have been made through programs like the National Tuberculosis Elimination Program, the path to eradication demands continued efforts.

Long-term follow-up of contacts of drug-resistant tuberculosis cases in high-burden areas of Mumbai, India

BackgroundDrug-resistant tuberculosis (DRTB) is a significant public health threat particularly in high burden areas like Mumbai, India. Contacts of DRTB cases are highly vulnerable to infection and development of active disease. In this study we assess long-term outcomes of contacts of DRTB cases, focusing on active TB development and the potential role of IGRA, vitamin D status and supplementation. MethodsA cohort of 262 DRTB contacts identified from a prior case-control study conducted in Mumbai were enlisted for the study. Interviews were conducted, and data were analysed using descriptive statistics and logistic regression. ResultsOf the 262 contacts, 34.73% had LTBI. Three contacts (1.36%) developed active TB, with a crude incidence rate of 4.64 per 1000 people. Vitamin D deficiency was prevalent in 75.3% of contacts, and all three TB cases were vitamin D deficient. Vitamin D supplementation showed a non-significant trend in reducing TB risk (OR = 0.56, p = 0.492). IGRA status did not significantly predict TB development. ConclusionThis study provides valuable insights into the long-term outcomes of contacts of DRTB cases. While baseline IGRA did not prove to predict development of active TB, association between vitamin D deficiency and TB development highlights the need for larger studies and development of more effective screening tools. The study contributes valuable information to TB control strategies in high-burden areas.

Synergistic effects of ceftazidime/avibactam combined with meropenem in a murine model of infection with KPC-producing Klebsiella pneumoniae.

The emergence and expansion of carbapenem-resistant Klebsiella pneumoniae infections is a concern due to the lack of 'first-line' antibiotic treatment options. The ceftazidime/avibactam is an important clinical treatment for carbapenem-resistant K. pneumoniae infections but there is an increasing number of cases of treatment failure and drug resistance. Therefore, a potential solution is combination therapies that result in synergistic activity against K. pneumoniae carbapenemase: producing K. pneumoniae (KPC-Kp) isolates and preventing the emergence of KPC mutants resistant to ceftazidime/avibactam are needed in lieu of novel antibiotics. To evaluate their synergistic activity, antibiotic combinations were tested against 26 KPC-Kp strains. Antibiotic resistance profiles, molecular characteristics and virulence genes were investigated by susceptibility testing and whole-genome sequencing. Antibiotic synergy was evaluated by in vitro chequerboard experiments, time-killing curves and dose-response assays. The mouse thigh model was used to confirm antibiotic combination activities in vivo. Additionally, antibiotic combinations were evaluated for their ability to prevent the emergence of ceftazidime/avibactam resistant mutations of blaKPC. The combination of ceftazidime/avibactam plus meropenem showed remarkable synergistic activity against 26 strains and restored susceptibility to both the partnering antibiotics. The significant therapeutic effect of ceftazidime/avibactam combined with meropenem was also confirmed in the mouse model and bacterial loads in the thigh muscle of the combination groups were significantly reduced. Furthermore, ceftazidime/avibactam plus meropenem showed significant activity in preventing the occurrence of resistance mutations. Our results indicated that the combination of ceftazidime/avibactam plus meropenem offers viable therapeutic alternatives in treating serious infections due to KPC-Kp.

Investigating Drug Interactions And Antibacterial Activity Of Vitamin C On Pathogenic Factors Of Escherichia Coli Clinical Isolates

Today, the phenomenon of multi-drug resistance has become a major cause of concern, and insufficient achievements have been made in the development of new antibiotics for the treatment of bacterial infections. Therefore, there is an unmet need for new auxiliary search. Vitamin C is one such promising supplement. The current study was conducted with the aim of explaining the antibacterial interaction effect of vitamin C in different concentrations (5-20 mg/ml) and drugs effective on Escherichia coli bacteria. In order to collect clinical samples during the months of September to November 2022, clinical samples were collected from 100 patients suspected of urinary tract infection who referred to medical centers. For identification, biochemical tests and gram staining and culture in IMViC and EMB environments were used to see metallic green polish. Then antimicrobial sensitivity test And the effect of antibiotic on biofilm formation, the effect of antibiotic and ascorbic acid on biofilm formation, biofilm inhibition rate was done for the single and combined effects of both antimicrobial substances. Finally, in order to investigate and identify the virulence gene of the isolated strains, DNA extraction was performed by PCR method. 45 samples of urinary infection culture were identified from the total of 100 samples collected, in 45 (45%) of them colonies with metallic polish were observed. 45% were men and 55% were women, and of these, a total of 45 positive E. coli cases were found in women and 17 positive cases were seen in men. Less than one year, teenagers, young and old were divided. 2 cases (2%) were in the age group of less than one year, 3 cases (3%) were teenagers, 63 cases (63%) were young and 32 cases (32%) were in the age group of middle-aged people. In a situation where the ability to form biofilm under vitamin C (ascorbic acid) treatment was not very effective and did not differ much from normal conditions, antibiotic treatment (under MBC gentamicin treatment) was somewhat successful in inhibiting biofilm formation, finally with the combination of antibiotic and Ascorbic acid was completely isolated in many resistant strains, the inability to form biofilm was evident, and this indicated the synergistic effects in the investigated composition. As the results showed, the ability to produce biofilm in the samples that had the target genes in this study was not much different from the other samples. Considering the increasing resistance to some antibiotics and wide changes in the effective spectrum of drugs and preventing the increase of drug-resistant cases, the necessity of conducting drug sensitivity tests seems very necessary. The high prevalence of E. coli antibiotic resistance and the high percentage of resistance genes in patients suffering from infections caused by this bacterium can indicate the excessive use of antibiotics. Finally, the prevalence of antibiotic resistance is a useful marker for investigating resistance genes and can be useful in ecological investigations. Also, with clear inhibitory effects, the selected antibiotic in this study along with ascorbic acid, this vitamin can be used as a supplement in some infections caused by E. coli bacteria.

Abstract 6918: Ba/F3-BCR-ABL engineering cell line panel, a useful platform for novel drug discovery

Abstract In the past few years, with the great success of Imatinib, the first kinase inhibitor, Imatinib rapidly became the first-line treatment for CML (Chronic myelogenous leukemia) carrying the BCR-ABL mutation. It opened a new chapter in targeted cancer treatment. Despite the increase in overall survival allowed by imatinib, the onset of drug resistance led scientists to investigate imatinib's fine structural mechanism of action to develop new and more effective compounds against mutated forms of Bcr-Abl. 7 BCR-ABL inhibitors have been approved, they are Imatinib, Dasatinib, Nilotinib, Bosutinib, Ponatinib, Olverembatinib, and Asciminib. However, acquired resistance has been a major challenge in the treatment of CML, and some patients still experience disease progression or even death due to drug resistance. BCR-ABL kinase domain mutations are one of the important mechanisms of acquired resistance, with the T315I mutation being the most common type of drug resistance mutation, accounting for approximately 25% of drug-resistant CML cases. Patients with T315I mutations in CML are resistant to all current first- and second-generation BCR-ABL inhibitors. Asciminib is designed as an allosteric inhibitor combined with an ATP-competitive TKI agent, which may hinder the development of mutation-driven acquired resistance or restore efficacy against highly resistant BCR-ABL mutants. Our group has generated 38 Ba/F3-BCR-ABL engineering cell lines as useful models for novel drug discovery in vitro and in vivo, including wild-type BCR-ABL and inhibitors leading drug resistance mutations, such as T315I, E255, Y253, F317, F359. V299, G250, A337T, V468F, and double mutations. Each cell was validated by cell sequencing and cell efficacy verification using approved BCR-ABL inhibitors. The Ba/F3-BCR-ABL engineering cell line panel can be useful for developing and evaluating next-generation BCR-ABL inhibitors and exploring newly acquired resistance mutations in BCR-ABL. Citation Format: Guoqian Wang, Yao Peng, Yu Wang, Yao Tang, Jingxiao Xu, Jinying Ning, Feng Hao. Ba/F3-BCR-ABL engineering cell line panel, a useful platform for novel drug discovery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6918.

Tuberculosis in people of Ukrainian origin in the European Union and the European Economic Area, 2019 to 2022.

Approximately five million Ukrainians were displaced to the EU/EEA following the Russian invasion of Ukraine. While tuberculosis (TB) notification rates per 100,000 Ukrainians in the EU/EEA remained stable, the number of notified TB cases in Ukrainians increased almost fourfold (mean 2019-2021: 201; 2022: 780). In 2022, 71% cases were notified in three countries, and almost 20% of drug-resistant TB cases were of Ukrainian origin. Targeted healthcare services for Ukrainians are vital for early diagnosis and treatment, and preventing transmission.

Associations of residential greenness exposure and ambient air pollutants with newly-diagnosed drug-resistant tuberculosis cases.

Growing evidence has found the health protective effects of greenness exposure on tuberculosis (TB) and the impact of ambient air pollutants on TB drug-resistance. However, it remains unclear whether residential greenness is also beneficial to reduce TB drug-resistance, and whether air pollution modify the greenness-TB resistance relationship. We enrolled 5006 newly-diagnosed TB patients from Shandong, China, during 2014 to 2021. Normalized Difference Vegetation Index (NDVI) in 250m and 500m buffer around individuals' residential zone was used to assess greenness exposure. All patients were divided by quartiles of NDVI250-m and NDVI500-m (from low to high: Q1, Q2, Q3, Q4) respectively. Six logistic regression models (NDVI, NDVI + PM2.5/PM10/SO2/NO2/O3) were used to estimate the association of NDVI and TB drug-resistance when adjusting different air pollutants or not. All models were adjusted for age, gender, body mass index, complications, smoking, drinking, population density, nighttime light index, road density. Compared with participants in NDVI250-m Q1 and NDVI500-m Q1, other groups had lower rates of MDR-TB, PDR-TB, RFP-resistance, SM-resistance, RFP + SM resistance, INH + RFP + EMB + SM resistance. NDVI500-m reduced the risk of multidrug resistant tuberculosis (MDR-TB) and the adjusted odds ratio (aOR, 95% confidence interval, CI) compared with NDVI500-m Q1 were 0.736 (0.547-0.991) in NDVI + PM10 model, 0.733 (0.544-0.986) in NDVI + PM2.5 model, 0.735(0.546-0.99) in NDVI + SO2 model, 0.736 (0.546-0.991) in NDVI + NO2 model, respectively, P < 0.05. NDVI500-m contributed to a decreased risk of streptomycin (SM)-resistance. The aOR of rifampicin (RFP) + SM resistance were 0.132 (NDVI250-m, Q4 vs Q1, 95% CI: 0.03-0.578), 0.199 (NDVI500-m, Q3 vs. Q1, 95% CI: 0.057-0.688) and 0.264 (NDVI500-m, Q4 vs. Q1, 95% CI: 0.087-0.799). The adjusted ORs (Q2 vs. Q1, 95% CI) of isoniazid (INH) + RFP + ethambutol (EMB) + SM resistance in 500m buffer were 0.276 (0.119-0.639) in NDVI model, 0.279 (0.11-0.705) in NDVI + PM10 model, 0.281 (0.111-0.713) in NDVI + PM2.5 model, 0.279 (0.11-0.709) in NDVI + SO2 model, 0.296 (0.117-0.754) in NDVI + NO2 model, 0.294 (0.116-0.748) in NDVI + O3 model, respectively. The study showed, for the first time, that residential greenness exposure in 500m buffer is beneficial for reducing newly-diagnosed DR-TB (including PDR-RB, MDR-TB, MR-TB), and ambient air pollutants may partially mediate this association.