Multidrug-resistant Mutants Research Articles

Case series of two persons living with HIV with detectable viral loads initiated then suppressed on cabotegravir/rilpivirine with lenacapavir.

Long-acting (LA) cabotegravir/rilpivirine (CAB/RPV) is primarily prescribed for virologically suppressed persons living with HIV (PLWH). Patients experiencing pill dysphagia or profound adherence challenges were excluded from the phase 3 studies, but recent reports demonstrate successful treatment in PWLH with baseline viremia. We describe two PLWH with detectable viral loads (VL) with multidrug resistance mutations. They were unable to sustain virologic suppression on oral therapy with historical poor adherence and dysphagia. Initiation of intramuscular CAB/RPV with subcutaneous lenacapavir (LEN) injections was necessary with baseline resistance. Due to anorexia and a low muscle mass, one patient received CAB/RPV injections in the vastus lateralis rather than the gluteal muscle with a 67-day delay between injections three and four due to health challenges. Both achieved viral suppression on monthly CAB/RPV with LEN. A return to health with a BMI increase from <14kg/m2 to almost 17kg/m2 resulted in the second patient. Injectable LA ART (CAB/RPV + LEN) in PLWH with detectable viremia results in sustained virologic suppression and a return to health and should now be considered a novel option for MDR patients with an inability to adhere to oral regimens.

Analysis of &lt;em&gt;Pfmdr1&lt;/em&gt; and &lt;em&gt;Pfcrt drug&lt;/em&gt; resistant markers in &lt;em&gt;Plasmodium falciparum&lt;/em&gt; following treatments of patients from Nyando and Mbita, Nyanza region with Artemisinin-based combination therapy

The multidrug resistance of Plasmodium falciparum to antimalarial drugs is a major public health concern in the global management of malaria, especially in developing countries. As of today, malaria treatment is primarily dependent on the sustained efficacy of artemisinin-based combination therapy (ACT). Recent reports indicating decline in efficacy of ACT and artesunate monotherapy in Southeast Asia are a major threat to global malaria control achievements. Initially, mutations in Pfmdr1 were associated with chloroquine and amodiaquine resistance only, but there are now emerging field study reports of Pfmdr1 mutation conferring tolerance to ACT. The current study used Restriction Fragment Length Polymorphism to evaluate the prevalence of genetic polymorphisms of Plasmodium falciparum multidrug resistance (Pfmdr1) and Plasmodium falciparum chloroquine-resistant transporter (Pfcrt) gene mutations in Mbita and Nyando field isolates. The findings report that the prevalence of Pfcrt K76T mutation in Plasmodium falciparum field isolates in Mbita declined significantly from 76.3% (95% CI 21.0-31.0) in 2008 to 51.9% (95% CI 19.0-25.0) in 2014, a reduction of 24.4% (χ2df =1 = 4.709, P = 0.0000). In Nyando, prevalence stood at 66.8% (95% CI 12.0-14.0) in 2014 down from 73.7% (95% CI 27.0-48.0), insignificant reduction of 6.9% (χ2df =1 = 17.699, P = 0.0913). Prevalence for Pfmdr1 in Mbita stood at 14.7% (95% CI 44.0-51.0) in 2014 down from 21.9% (95% CI 31.0-49.0) in 2008, a significant reduction of 4.3% (χ2df =1 = 9.011, P = 0.001). While in Nyando, field isolate samples recorded 16.2% (95% CI 22.0-31.0) in 2014, down from 30.6% (95% CI 12.0-27.0), insignificant reduction of 1.9% (χ2df =1 = 11.777, P = 0.0591). Our findings confirm a common trend reported by previous studies: that there has been a small decline in the prevalence of the Pfcrt mutation over a decade since the withdrawal of Chloroquine as the first line of treatment for uncomplicated cases of malaria in Kenya.

Multi-drug resistant gene mutation analysis in Mycobacterium tuberculosis by molecular techniques.

Rifampicin (RIF) and isoniazid (INH), two most potent antibiotics, are prescribed to cure tuberculosis. Mycobacterium tuberculosis, the causative agent of multidrug-resistant tuberculosis (MDR-TB), is resistant to these first-line drugs. Here, two molecular techniques were demonstrated such as PCR sequencing-based and GeneXpert assay for rapidly identifying MDR-TB. Pulmonary samples (sputum) were collected from 55 MDR-TB suspected patients from the National Tuberculosis Reference Laboratory (NTRL), Dhaka where the research work was partially accomplished and continued in the department of Microbiology, University of Dhaka, Bangladesh. We strived for sequencing technique as well as GeneXpert assay to identify mutations in rpoB and katG genes in MTB strains and sputum directly. Culture-based drug susceptibility testing (DST) was performed to measure the efficacy of the molecular methods employed. When analyzed, rpoB gene mutations at codons 531 (54.54%), 526 (14.54%), and 516 (10.91%) were found by sequencing in 80% of the samples. Nucleotide substitution at katG315 (AGC→ACC) was spotted in 16 (76.19%) out of 21 samples. When comparing the sequencing results with DST, sensitivity and specificity were investigated to determine drug-resistance (rifampicin-resistance were 98 and 100% whereas isoniazid-resistance were 94 and 100% respectively). Additionally, as a point of comparison with DST, only 85.45% of RIF mono-resistant TB cases were accurately evaluated by the GeneXpert assay. This research supports the adoption of PCR sequencing approach as an efficient tool in detecting MDR-TB, counting the higher sensitivity and specificity as well as the short period to produce the results.

Changes in Primary HIV-1 Drug Resistance Due to War Migration from Eastern Europe

In recent years, especially as a result of war in Ukraine, enormous movements of migration to Poland from eastern European countries have been reported, including people living with Human Immunodeficiency Virus (HIV). We have conducted multi-center, prospective study, which aimed to establish HIV-1 subtype and assess the presence of primary drug resistance mutations to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors and protease inhibitors in antiretroviral treatment naïve patients. The clinical trial recruited 117 individuals during 2 years period (2020–2022). The prevalence of HIV-1 subtype A was statistically significantly more frequent in Ukrainian, and HIV-1 subtype B in Polish patients (p < 0.05). Drug resistance mutations were detected in 44% of all cases and the comparison of presence of mutations in the analyzed groups, as well as in the subgroups of subtype A and B HIV-1 has not revealed any significant differences (p > 0.05), nevertheless Polish patients had multidrug resistance mutations more frequent (p < 0.05). The results from our trial show no increased risk of transmission of multidrug resistant HIV strains in our cohort of Ukrainian migrants.Clinical trials. Gov number NCT04636736; date of registration: November 19, 2020.

Multiple and multidrug resistance in Botrytis cinerea: molecular mechanisms of MLR/MDR strains in Greece and effects of co-existence of different resistance mechanisms on fungicide sensitivity.

Botrytis cinerea is a high-risk pathogen for fungicide resistance development. Within the fungal populations, strains have developed multiple mutations in different target genes leading to multiple resistance (MLR) or mutations associated with overexpression of efflux transporters leading to multidrug resistance (MDR). These types of resistance are a major threat, and their successful management is a major challenge. The current study was initiated to a) determine frequencies of MLR/MDR strains in populations originating from several crops, b) identify the types of MDR that occur in Greece, and c) determine interactions between MLR and MDR at the level of sensitivity to botryticides. The frequencies of MLR/MDR phenotypes were determined in 515 isolates subjected to bioassays using discriminatory concentrations of thiophanate-methyl, iprodione, cyprodinil, fenhexamid, boscalid, fluopyram, fludioxonil, pyraclostrobin, and tolnaftate. Interestingly, 7.8% and 31.3% of isolates from strawberry and rootstock seedlings were resistant to every single fungicide class, while MDR phenotypes from strawberries, rootstocks, and tomatoes accounted for 26%, 87%, and 13.4%, respectively. The MLR and MDR isolates were further molecularly analyzed regarding genes erg27, sdhB, Bcpos5, and Mrr1, responsible for resistance to fenhexamid, boscalid and fluopyram, cyprodinil, and MDR, respectively. The different mutations' presence was determined along with a new mutation in Mrr1 leading to MDR. MDR isolates were characterized as MDR1 or MDR1h based on the presence of a 3-bp deletion in Mrr1. MDR1h was predominant in isolates from rootstocks and MDR1 from tomatoes and strawberries, whereas the most frequent target-site mutations were F412S (erg27), H272R (sdhB), and L412F (Bcpos5). To determine whether the accumulation of target-site mutations along with MDR mutations exhibits an additive effect concerning fungicide resistance, the sensitivity of isolates possessing the predominant target-site mutations was calculated in both the presence and the absence of MDR-associated mutations. EC50 in cyprodinil and boscalid increased to about twofold in the presence of MDR mutations, while there was no difference for fenhexamid. In conclusion, MLR/MDR frequencies are notably high in heavily treated crops in Greece, and the combination of MLR and MDR mutations leads to even higher fungicide resistance levels, highlighting the importance of resistance management.

Resistance Improvement and Sensitivity Enhancement of Cancer Therapy by a Novel Antitumor Candidate onto A2780 CP and A2780 S Cell Lines.

To overcome cisplatin resistance, the cytotoxicity of a novel antitumor agent on two ovarian cancer cell lines sensitive and resistant to cisplatin was investigated. MTT assay and flow cytometry were performed to assess the cytotoxicity of a novel water-soluble Pd (II) complex, [Pd(bpy)(pyr-dtc)]NO3 (PBPD), on cisplatin-sensitive and cisplatin-resistant ovarian cancer cell lines. Furthermore, variations in the expression of drug resistance gene cluster of differentiation 99 (CD99), signal transducer and activator of transcription 3 (STAT3), octamer-binding transcription factor 4 (OCT4), and multidrug resistance mutation 1 (MDR1) were evaluated using Real-Time PCR. The IC50 values of PBPD in resistant cells were higher than those in sensitive cells. Furthermore, PBPD has a deadlier effect on sensitive cells compared to resistant cells, and the cell survival rate is reduced over time. Flow cytometry revealed that PBPD enhanced the population of living-resistant cells while driving them to apoptosis. PBPD, on the other hand, has a greater effect on the living cell population and has dramatically shifted the population toward apoptosis and necrosis in the sensitive cells. Furthermore, gene expression analysis showed that when sensitive and resistant cells were treated with cisplatin, all resistance genes increased significantly relative to the control. In contrast to OCT4, MDR1, STAT3, and CD99 resistance genes were not significantly elevated in sensitive cells treated with PBPD compared to the control. Thus, the expression of resistance genes in resistant cells treated with PBPD was lower than cisplatin. As a result, PBPD is a promising anticancer agent for CDDP-resistant ovarian cancer.

Multidrug-resistant mutations to antiviral and antibody therapy in an immunocompromised patient infected with SARS-CoV-2

Antiviral and antibody therapies for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are being recommended for high-risk patients, but the potential for the development of multidrug-resistant mutations in immunocompromised patients is unclear. To investigate the treatment course in cases of prolonged viral shedding in an immunocompromised patient with SARS-CoV-2 infection, we conducted longitudinal measurements of laboratory tests, chest computed tomography (CT) image evaluations, antibody titers, and antigen levels in nasopharyngeal swabs. Furthermore, we performed whole-genome sequencing and digital PCR analysis to examine the mechanisms of drug resistance. We present a case of a 65-year-old man with a history of malignant lymphoma who was treated with multiple antiviral and antibody therapies, including sotrovimab, remdesivir, paxlovid (nirmatrelvir/ritonavir), and molnupiravir. Initially, viral antigen levels decreased after treatments. However, after the virus rebounded, the patient showed no virologic response. The viral genome analysis revealed a single Omicron subvariant (BA.1.1), which evolved within the host during the disease progression. The viruses had acquired multiple resistance mutations to nirmatrelvir (3 chymotrypsin-like protease [3CLpro] E166 A/V), sotrovimab (spike P337L and E340K), and remdesivir (RNA-dependent RNA polymerase [RdRp] V166L). Our results indicate that viruses with multidrug-resistant mutations and survival fitness persist in the infected subpopulation after drug selection pressure. This study was supported by the JSPS KAKENHI Early-Career Scientists 18K16292 (Y.H.), Grant-in-Aid for Scientific Research (B) 20H03668 and 23H02955 (Y.H.), the YASUDA Medical Foundation (Y.H.), the Uehara Memorial Foundation (Y.H.), the Takeda Science Foundation (Y.H.), and Kato Memorial Bioscience Foundation (Y.H.).

Genomic analysis of Indian isolates of Plasmodium falciparum: Implications for drug resistance and virulence factors

The emergence of drug resistance to frontline treatments such as Artemisinin-based combination therapy (ACT) is a major obstacle to the control and eradication of malaria. This problem is compounded by the inherent genetic variability of the parasites, as many established markers of resistance do not accurately predict the drug-resistant status. There have been reports of declining effectiveness of ACT in the West Bengal and Northeast regions of India, which have traditionally been areas of drug resistance emergence in the country. Monitoring the genetic makeup of a population can help to identify the potential for drug resistance markers associated with it and evaluate the effectiveness of interventions aimed at reducing the spread of malaria. In this study, we performed whole genome sequencing of 53 isolates of Plasmodium falciparum from West Bengal and compared their genetic makeup to isolates from Southeast Asia (SEA) and Africa. We found that the Indian isolates had a distinct genetic makeup compared to those from SEA and Africa, and were more similar to African isolates, with a high prevalence of mutations associated with antigenic variation genes. The Indian isolates also showed a high prevalence of markers of chloroquine resistance (mutations in Pfcrt) and multidrug resistance (mutations in Pfmdr1), but no known mutations associated with artemisinin resistance in the PfKelch13 gene. Interestingly, we observed a novel L152V mutation in PfKelch13 gene and other novel mutations in genes involved in ubiquitination and vesicular transport that have been reported to support artemisinin resistance in the early stages of ACT resistance in the absence of PfKelch13 polymorphisms. Thus, our study highlights the importance of region-specific genomic surveillance for artemisinin resistance and the need for continued monitoring of resistance to artemisinin and its partner drugs.

A Herpes Simplex Virus 1 DNA Polymerase Multidrug Resistance Mutation Identified in a Patient With Immunodeficiency and Confirmed by Gene Editing.

Herpes simplex virus 1 can cause severe infections in individuals who are immunocompromised. In these patients, emergence of drug resistance mutations causes difficulties in infection management. Seventeen herpes simplex virus 1 isolates were obtained from orofacial/anogenital lesions in a patient with leaky severe combined immunodeficiency over 7 years, before and after stem cell transplantation. Spatial/temporal evolution of drug resistance was characterized genotypically-with Sanger and next-generation sequencing of viral thymidine kinase (TK) and DNA polymerase (DP)-and phenotypically. CRISPR/Cas9 was used to introduce the novel DP Q727R mutation, and dual infection-competition assays were performed to assess viral fitness. Isolates had identical genetic backgrounds, suggesting that orofacial/anogenital infections derived from the same virus lineage. Eleven isolates proved heterogeneous TK virus populations by next-generation sequencing, undetectable by Sanger sequencing. Thirteen isolates were acyclovir resistant due to TK mutations, and the Q727R isolate additionally exhibited foscarnet/adefovir resistance. Recombinant Q727R mutant virus showed multidrug resistance and increased fitness under antiviral pressure. Long-term follow-up of a patient with severe combined immunodeficiency revealed virus evolution and frequent reactivation of wild-type and TK mutant strains, mostly as heterogeneous populations. The DP Q727R resistance phenotype was confirmed with CRISPR/Cas9, a useful tool to validate novel drug resistance mutations.

A transverse colon lipoma complicated with an adenoma is successfully and safely resected en bloc by endoscopic mucosal resection during water immersion

The B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1) is associated with the progression of gastric cancer (GC). However, its role in drug resistance of gastric cancer stem cell (GCSC) remains unclear. This study aimed to explore the biological function of BMI-1 in GC cells and its role in drug resistance of GCSCs.We assessed BMI-1 expression in the GEPIA database and in our collected samples from patients with GC. We silenced BMI-1 using siRNA to study the cell proliferation and migration of GC cells. We also used Hoechst 33342 staining to verify the effect of adriamycin (ADR) on side population (SP) cells, and measured the effects of BMI-1 on the expression of N-cadherin, E-cadherin, and drug-resistance-related proteins (multidrug resistance mutation 1 and lung resistance-related protein). Finally, we analyzed BMI-1-related proteins uing the STRING and GEPIA databases.BMI-1 mRNA was upregulated in GC tissues and cell lines, especially in MKN-45 and HGC-27 cells. Silencing BMI-1 reduced the proliferation and migration of GC cells. Knocking down BMI-1 significantly decreased epithelial-mesenchymal transition progression, expression levels of drug-resistant proteins, and the number of SP cells in ADR-treated GC cells. Bioinformatics analysis showed that EZH2, CBX8, CBX4, and SUZ12 were positively correlated with BMI-1 in GC tissues.Our study demonstrates that BMI-1 affects the cellular activity, proliferation, migration, and invasion of GC cells. Silencing the BMI-1 gene significantly reduces the number of SP cells and the expression of drug-resistant proteins in ADR-treated GC cells. We speculate that inhibition of BMI-1 increases the drug resistance of GC cells by affecting GCSCs, and that EZH2, CBX8, CBX4, and SUZ12 may participate in BMI-1-induced enhancement of GCSC-like phenotype and viability.

Abstract 1281: Oncoprotein YB-1 modulation of Lyn-MAPK-NF-kB pathway, a potential therapeutic strategy combined with sorafenib for advanced stage HCC

Abstract The Y-Box Binding protein 1 (YB-1) is a 324 amino acid-long member of the Cold Shock Domain (CSD) protein superfamily. YB-1 interacts with micro RNAs and non-coding RNAs in the cytoplasm, acting as a regulator of mRNA translation. YB-1 translocation into the nucleus is circadian clock-dependent and leads to the upregulation of cyclin gene expression, among others. Another mechanism of nuclear translocation of YB-1 is mediated by phosphorylation of the Ser 102 residue in the CSD. The YB-1 oncoprotein acts as a transcription factor when bound to DNA, modulating the transcription of genes that regulate biological processes such as Multidrug Resistance Mutation 1 (MDR1). YB-1 is linked to poor prognosis in breast, prostate, and liver cancer. Despite advances in biomedicine, the incidence and mortality of hepatocellular carcinoma (HCC) remain high. Sorafenib, a tyrosine kinase Inhibitor (TKI), is the first-line treatment for advanced HCC. Sorafenib also inhibits downstream activation of NF-kB by inhibition of Lyn phosphorylation (Y397). However, it was observed in many patients that its sorafenib’s effectiveness is hampered by drug resistance, but the mechanism is still unclear. We have found that SK-HEP-1 HCC cells transfected with a YB-X-1 overexpression plasmid subsequently developed into a stable YB-1 overexpression cell line (SK-HEP-1+YB-1) displayed increased invasion, migration, proliferation, and colony formation property as compared to the vector control (SKHEP1+Vec). The SK-HEP-1+YB-1 cell line also showed increased IC50 for sorafenib and elevated phosphorylation of Lyn (Y397) and further activated NF-kB (S165/S176) phosphorylation. This indicates YB-1 may cause increased Sorafenib resistance in HCC by activating tyrosine kinases (TK), such as lyn, and simultaneous activation of NF-kB. The combination of YB-1 inhibition and sorafenib might provide a novel therapeutic strategy and improve the survival of patients with advanced-stage HCC. Citation Format: Ana G. Ayala Pazzi, Omar Karkoutly, Kristopher Ezell, Samantha Lopez, Kyle D. Doxtater, Elias George, Vijian Dhevan, Manish K. Tripathi. Oncoprotein YB-1 modulation of Lyn-MAPK-NF-kB pathway, a potential therapeutic strategy combined with sorafenib for advanced stage HCC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1281.

B-cell-specific Moloney murine leukemia virus integration site 1 knockdown impairs adriamycin resistance of gastric cancer cells

Background and study aimsThe B-cell-specific Moloney murine leukemia virus integration site 1 (BMI-1) is associated with the progression of gastric cancer (GC). However, its role in drug resistance of gastric cancer stem cell (GCSC) remains unclear. This study aimed to explore the biological function of BMI-1 in GC cells and its role in drug resistance of GCSCs. Patients and methodsWe assessed BMI-1 expression in the GEPIA database and in our collected samples from patients with GC. We silenced BMI-1 using siRNA to study the cell proliferation and migration of GC cells. We also used Hoechst 33342 staining to verify the effect of adriamycin (ADR) on side population (SP) cells, and measured the effects of BMI-1 on the expression of N-cadherin, E-cadherin, and drug-resistance-related proteins (multidrug resistance mutation 1 and lung resistance-related protein). Finally, we analyzed BMI-1-related proteins uing the STRING and GEPIA databases. ResultsBMI-1 mRNA was upregulated in GC tissues and cell lines, especially in MKN-45 and HGC-27 cells. Silencing BMI-1 reduced the proliferation and migration of GC cells. Knocking down BMI-1 significantly decreased epithelial-mesenchymal transition progression, expression levels of drug-resistant proteins, and the number of SP cells in ADR-treated GC cells. Bioinformatics analysis showed that EZH2, CBX8, CBX4, and SUZ12 were positively correlated with BMI-1 in GC tissues. ConclusionOur study demonstrates that BMI-1 affects the cellular activity, proliferation, migration, and invasion of GC cells. Silencing the BMI-1 gene significantly reduces the number of SP cells and the expression of drug-resistant proteins in ADR-treated GC cells. We speculate that inhibition of BMI-1 increases the drug resistance of GC cells by affecting GCSCs, and that EZH2, CBX8, CBX4, and SUZ12 may participate in BMI-1-induced enhancement of GCSC-like phenotype and viability.

Combination Chemotherapy of Multidrug-resistant Early-stage Colon Cancer: Determining Optimal Dose Schedules by High-performance Computer Simulation.

The goal of this project was to utilize mechanistic simulation to demonstrate a methodology that could determine drug combination dose schedules and dose intensities that would be most effective in eliminating multidrug resistant cancer cells in early-stage colon cancer. An agent-based model of cell dynamics in human colon crypts was calibrated using measurements of human biopsy specimens. Mutant cancer cells were simulated as cells that were resistant to each of two drugs when the drugs were used separately. The drugs, 5-flurouracil and sulindac, have different mechanisms of action. An artificial neural network was used to generate nearly two hundred thousand two-drug dose schedules. A high-performance computer simulated each dose schedule as a in silico clinical trial and evaluated each dose schedule for its efficiency to cure (eliminate) multidrug resistant cancer cells and its toxicity to the host, as indicated by continued crypt function. Among the dose schedules that were generated, 2430 dose schedules were found to cure all multidrug resistant mutants in each of the 50 simulated trials and retained colon crypt function. One dose schedule was optimal; it eliminated multidrug resistant cancer cells with the minimum toxicity and had a time schedule that would be practical for implementation in the clinic. These results demonstrate a procedure to identify which combination drug dose schedules could be most effective in eliminating drug resistant cancer cells. This was accomplished using a calibrated agent-based model of a human tissue, and a high-performance computer simulation of clinical trials.

Exposure of Pseudomonas aeruginosa to Cinnamaldehyde Selects Multidrug Resistant Mutants.

Cinnamaldehyde (CNA), the main component of cinnamon essential oil, is one of the most active plant compounds against nosocomial pathogen Pseudomonas aeruginosa. Exposure of wild-type strain PA14 (MIC 700 µg/mL) for 5 to 10 days to fixed (900 µg/mL) or increasing (from 900 to 1400 µg/mL) concentrations of this natural antibacterial resulted in emergence of resistant mutants CNA-A1 to A3, and CNA-B1 to B7, respectively. Genome sequencing experiments showed that each of CNA-A1 to A3 mutants differed from PA14 by one SNP, and a slight increase in CNA resistance level (from 700 to 900 µg/mL). By comparison, mutants B1 to B7 were more resistant (up to 1100 µg/mL); each of them harbored multiple SNPs (from 24 to 39) likely as a consequence of alteration of DNA mismatch repair gene mutS. Of the ten mutants selected, eight contained mutations in gene nalC, which indirectly downregulates expression of the operon that codes for multidrug efflux system MexAB-OprM, and showed increased resistance (up to 16-fold versus PA14) to antibiotic molecules exported by the pump, including ß-lactams and fluoroquinolones. Of the six mutants with the highest CNA resistance, five were no longer motile because of alteration of genes flgJ, fliE and/or pilJ genes. Altogether, our data show that P. aeruginosa is able to adapt to strong electrophilic molecules such as CNA by upregulating its intrinsic efflux pump MexAB-OprM, and through less well-characterized pleiotropic changes. Whether multidrug-resistant mutants can emerge in patients using cinnamon essential oil as self-medication needs to be assessed further.

P fmdr 1 and kelch 13 genes distribution among children that are 5years and below in Akure, Nigeria.

Malaria parasite resistant to drugs has been a major barrier to effective treatment of malaria. Therefore, the study aimed to evaluate the distribution of Plasmodium falciparum resistant Kelch protein gene on chromosome 13 (Kelch 13) and multidrug resistant (Pfmdr1) mutant genes among children aged five years and below who attended Mother and Child Hospital, Akure, Nigeria. Thin and thick smears were prepared from the blood collected aseptically through venepuncture from five hundred (500) children. Structured questionnaires were used to obtain demographic data from the respondents. Two hundred malaria positive samples were randomly selected from the 500 samples for PCR analysis to detect Pfmdr1 and Kelch 13 mutant genes. The results showed that of the 500 respondents, 288 (57.6%) were males while 21 (42.4%) were females. Pfmdr1distribution include: mixed group (mutant/wild) 38.5%, mutant gene 35.5%, wild gene 20.5% and the resistant genes were absent in 5.5% of the infected children. The mixed group of Pfmdr1 gene was higher among infants (51.9%), children with birth order 4 (60.0%) and children that have blood group B (51.3%), however, there is no significant difference in the distribution of Pfmdr1 between gender (χ2 = 0.634, df = 1, p > 0.05). There was a point mutation in the codon position 557 where the amino acid Alanine was replaced by Serine in the PfK13. The presence of Pfmdr1 mutant genes and point mutation in the PfK13 gene of P. falciparum among children, calls for development of innovative drugs targeted on these resistant strains.

KMT2C mutation in a Chinese man with primary multidrug-resistant metastatic adenocarcinoma of rete testis: a case report

BackgroundAdenocarcinoma of the rete testis (AORT) is an extremely rare malignant tumor with poor prognosis and limited responsiveness to traditional chemotherapy. Few previous studies have focused on the molecular mechanisms underlying therapy resistance in AORT and further scrutiny is required to enable searches for targeted drugs to guide treatment selection.Case presentationThe current case concerns a 55-year-old man with AORT who presented with isolated bone metastasis at initial diagnosis and experienced rapid disease progression after multi-line platinum-based combination chemotherapy. Next-generation sequencing revealed a novel somatic lysine methyltransferase 2C (KMT2C) c.5605 T > C mutation in exon 36 with an abundance of 49.27%. The patient received antiangiogenic drug treatment for 2 months but this was discontinued due to unacceptable anorexia and nausea. He survived for 12 months after diagnosis.ConclusionA potential correlation between AORT primary multi-drug resistance and KMT2C mutations is implied. Further studies are needed to determine the efficacy of PARP1/2 inhibitors for tumors with KMT2C mutations.

Evolution under low antibiotic concentrations: a risk for the selection of Pseudomonas aeruginosa multidrug-resistant mutants in nature.

Antibiotic pollution of non-clinical environments might have a relevant impact on human health if resistant pathogens are selected. However, this potential risk is often overlooked, since drug concentrations in nature are usually below their minimal inhibitory concentrations (MICs). Albeit, antibiotic resistant bacteria can be selected even at sub-MIC concentrations, in a range known as the sub-MIC selective window. Using short-term evolution experiments, we have determined the sub-MIC selective windows of the opportunistic pathogen Pseudomonas aeruginosa for seven antibiotics of clinical relevance, finding the ones of quinolones to be the widest, and the ones of polymyxin B and imipenem, the narrowest. Clinically relevant multidrug-resistant mutants arose within the sub-MIC selective windows of most antibiotics tested, being some of these phenotypes mediated by efflux pumps' activity. The fact that the concentration of antibiotics reported in aquatic ecosystems - colonizable by P. aeruginosa - are, in occasions, higher than the ones that select multidrug-resistant mutants in our assays, has implications for understanding the role of different ecosystems and conditions in the emergence of antibiotic resistance from a One-Health perspective. Further, it reinforces the importance of procuring accurate information on the sub-MIC selective windows for drugs of clinical value in pathogens with environmental niches.

Early detection of MDR Mycobacterium tuberculosis mutations in Pakistan

The result of improper treatment has led to the rise of Multidrug-resistant (MDR) strains. This concern still exists in Pakistan. In order to save energy, time and resources an early detection of resistant cases is imperative. Thus, a treated group of 100 isolates and a control group of 56 untreated isolates were studied. PCR and gene sequencing showed mutations at codon 531 and 513 in the rpoB gene. 12% of cases showed a double mutation in the rpoB gene. katG gene showed mutations at codon 315 and 299. 28.6% of the control group cases were positive for MDR whereas 100% of the treated group were positive for MDR. This study explores the significantly increasing ratio of MDR-TB among Pakistani population. This study provides prevalent MDR mutations among Pakistanis and suggests developing such molecular assays that are time and cost effective. Importance: Pakistan is a developing country and has fourth highest incidence rate of MDR-TB. The treatment of MDR-TB is the use of second line drugs that has severe side effects as well as it requires long time span. One of the strategies to control the spread of MDR-TB is to decipher the aberrations at molecular level in order to formulate potent drugs that can treat the patients within short span of time. Determining the mutation profile of MDR in Pakistani populations will open new horizons for the improvement of drug treatment regimens to make it more effective or for the development of novel potent drugs and vaccines to better treat the drug-resistant TB. Moreover, this study will be help in disease control program.

Proteomic Landscape of a Drug-Tolerant Persister Subpopulation of Mycobacterium tuberculosis.

Persisters are a subpopulation of bacteria that resist killing by antibiotics, even though they are genetically similar to their drug-susceptible counterpart. Like in several other bacteria, persisters are also reported in the human pathogen Mycobacterium tuberculosis (Mtb). Stochastic formation of Mtb persisters with a high level of antimicrobial tolerance set the stage for subsequent multidrug-resistant mutations. Despite significant advancement in our understanding, much remains to be learnt about the biology of this drug-recalcitrant bacterial subpopulation. Most of the information pertaining to the metabolic evolution required for emergence of drug tolerance in tuberculosis (TB) pathogens has come from transcriptional, metabolomic, and mutagenesis studies. Since proteins are the key functional molecules regulating the majority of metabolic activities in the cell, investigation of the whole-cell protein expression profile will further provide valuable insights into the physiology of Mtb persisters. We performed a quantitative proteomic analysis of Mtb H37Rv cultured under an in vitro persistence model to identify the proteomic profile of the phenotypic drug-tolerant bacterial population. Our study reveals that proteins related to intermediary metabolism and respiration, cell-wall and cell processes, lipid metabolism, information pathways, and virulence, detoxification and adaptation functional categories are primarily modulated in the persister subpopulation. Further, we demonstrate that various surface-localized mycobacterial membrane protein large (MmpL) proteins, which exhibit a high level of expression in Mtb persisters, are crucial for the mycobacterial survival during persistent growth state. A drug-induced persister subpopulation of Mtb exhibit various differentially regulated proteins that might be critical in mitigating the antimicrobial effect of drugs and can be further explored to develop novel anti-TB agents. The peptide identifications and tandem mass spectra (MS/MS) have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD013621.

The association of a genetic variant in multi-drug resistance gene and colorectal cancer susceptibility

Colorectal cancer (CRC) is one of the most malignant tumors worldwide with poor prognosis. There are various genetic polymorphisms associated with colorectal cancer have been reported in recent studies. Here, we examined the relationship between the multidrug resistance mutation 1 (MDR1 or ATP-binding cassette sub-family B member 1, ABCB1) (rs1128503) polymorphism and the risk of CRC in 334 individuals with or without CRC. DNA was extracted and genotyped using a Taq-Man based PCR method. The MDR1 polymorphism was shown to be related to the susceptibility for CRC using recessive (OR = 3.76, CI = 2.18–6.51, p < 0.001) and dominant models (OR = 1.96, CI = 1.12–3.45, p = 0.01). No association was found between the variant and Marriage/Education/Smoking/alcohol-consumption status. Our findings demonstrated the association of the genetic variant in the MDR1 gene with susceptibility to CRC, suggesting its potential role as a risk stratification biomarker in CRC patients.